WorldWideScience

Sample records for hot gas duct

  1. Depressurization test on hot gas duct

    International Nuclear Information System (INIS)

    Tanihira, Masanori; Kunitomi; Kazuhiko; Inagaki, Yoshiyuki; Miyamoto, Yoshiaki; Sato, Yutaka.

    1989-05-01

    To study the integrity of internal structures and the characteristics in a hot gas duct under the rapid depressurization accident, depressurization tests have been carried out using a test apparatus installed the hot gas duct with the same size and the same structures as that of the High Temperature Engineering Test Reactor (HTTR). The tests have been performed with three parameters: depressurization rate (0.14-3.08 MPa/s) determined by orifice diameter, area of the open space at the slide joint (11.9-2036 mm 2 ), and initial pressure (1.0-4.0 MPa) filled up in a pressure vessel, by using nitrogen gas and helium gas. The maximum pressure difference applied on the internal structures of the hot gas duct was 2.69 MPa on the liner tube and 0.45 MPa on the separating plate. After all tests were completed, the hot gas duct which was used in the tests was disassembled. Inspection revealed that there were no failure and no deformation on the internal structures such as separating plates, insulation layers, a liner tube and a pressure tube. (author)

  2. Thermal performance test of the hot gas ducts of HENDEL

    International Nuclear Information System (INIS)

    Hishida, M.; Kunitomi, K.; Ioka, I.; Umenishi, K.; Tanaka, T.; Shimomura, H.; Sanokawa, K.

    1984-01-01

    A hot gas duct provided with internal thermal insulation is to be used for high-temperature gas-cooled reactors (HTGR). This type of hot gas duct has not been used so far in industrial facilities, and only a couple of tests on such a large-scale model of a hot gas duct have been conducted. The present report deals with the results of the thermal performance of the single tube type hot gas ducts which are installed as parts of a helium engineering demonstration loop (HENDEL). Uniform temperature and heat flux distribution at the surface of the duct were observed, the experimental correlations being obtained for the effective thermal conductivity of the internal thermal insulation layer. The measured temperature distribution of the pressure tube was in good agreement with the calculation by a TRUMP heat transfer computer code. The temperature distribution of the inner tube of the co-axial hot gas duct was evaluated and no hot spot was detected. These results would be very valuable for the design and development of HTGR. (orig.)

  3. Status of the development of hot gas ducts for HTRs

    International Nuclear Information System (INIS)

    Stehle, H.; Klas, E.

    1984-01-01

    In the PNP nuclear process heat system the heat generated in the helium cooled core is transferred to the steam reformer and to the successive steam generator or to the intermediate heat exchanger by the primary helium via suitable hot gas ducts. The heat is carried over to the steam gasifier by the intermediate heat exchanger and a secondary helium loop. In both the primary and the secondary loop, the hot gas ducts are internally insulated by a ceramic fibre insulation to protect the support tube and the pressure housing from the high helium temperatures. A graphite hot gas liner will be used for the coaxial primary duct with an annular gap between support tube and pressure shell for the cold gas counterflow. A metallic hot gas liner will be installed in the secondary duct

  4. Thermal performance test of hot gas ducts of helium engineering demonstration loop (HENDEL)

    International Nuclear Information System (INIS)

    Hishida, Makoto; Kunitomi, Kazuhiko; Ioka, Ikuo; Umenishi, Koji; Kondo, Yasuo; Tanaka, Toshiyuki; Shimomura, Hiroaki

    1984-01-01

    A hot gas duct provided with internal thermal insulation is supposed to be used for an experimental very high-temperature gas-cooled reactor (VHTR) which has been developed by the Japan Atomic Energy Research Institute (JAERI). This type of hot gas duct has not been used so far in industrial facilities, and only a couple of tests on such a large-scale model of hot gas duct have been conducted. The present test was to investigate the thermal performance of the hot gas ducts which are installed as parts of a helium engineering demonstration loop (HENDEL) of JAERI. Uniform temperature and heat flux distributions at the surface of the duct were observed, the experimental correlation being obtained for the effective thermal conductivity of the internal thermal insulation layer. The measured temperature distribution of the pressure tube was in good agreement with the calculation by a TRUMP heat transfer computer code. The temperature distribution of the inner tube of VHTR hot gas duct was evaluated, and no hot spot was detected. These results would be very valuable for the design and development of VHTR. (author)

  5. Experimental optimization of temperature distribution in the hot-gas duct through the installation of internals in the hot-gas plenum of a high-temperature reactor

    International Nuclear Information System (INIS)

    Henssen, J.; Mauersberger, R.

    1990-01-01

    The flow conditions in the hot-gas plenum and in the adjacent hot-gas ducts and hot-gas pipes for the high-temperature reactor project PNP-1000 (nuclear process heat project for 1000 MW thermal output) have been examined experimentally. The experiments were performed in a closed loop in which the flow model to be analyzed, representing a 60deg sector of the core bottom of the PNP-1000 with connecting hot-gas piping and diverting arrangements, was installed. The model scale was approx. 1:5.6. The temperature and flow velocity distribution in the hot-gas duct was registered by means of 14 dual hot-wire flowmeters. Through structural changes and/or the installation of internals into the hot-gas plenum of the core bottom offering little flow resistance coolant gas temperature differentials produced in the core could be reduced to such an extent that a degree of mixture amounting to over 80% was achieved at the entrance of the connected heat exchanger systems. Thereby the desired goal of an adequate degree of mixture of the hot gas involving an acceptable pressure loss was reached. (orig.)

  6. Research on thermal insulation for hot gas ducts

    International Nuclear Information System (INIS)

    Broeckerhoff, P.

    1984-01-01

    The inner surfaces of prestressed reactor vessels and hot gas ducts of Gas Cooled High Temperature Reactors need internal thermal insulation to protect the pressure bearing walls from high temperatures. The design parameters of the insulation depend on the reactor type. In a PNP-plant temperature and pressure of the cooling medium helium are proposed to be 950 deg. C and 40 bars, respectively. The experimental work was started at KFA in 1971 for the HHT-project using three test facilities. At first metallic foil insulation and stuffed fibre insulating systems, the hot gas ducting shrouds of which were made of metal, have been tested. Because of the elevated helium temperature in case of PNP and the resulting lower strength of the metallic parts the interest was directed to rigid ceramic materials for the spacers and the inner shrouds. This led to modified structures designed by the INTERATOM company. Tests were performed at KFA. The main object of the investigations was to study the influence of temperature, pressure and axial pressure gradients on the thermal efficiency of the structures. Moreover, the temperatures within the insulation, at the pressure tube, and at the elements which bear the inner shrouds were measured. Thermal fluxes and effective thermal conductivities in axial and circumferential direction of the pressure tube are given, mainly for the INTERATOM-design with spherical spacers. (author)

  7. Analysis of graphite dust deposition in hot gas duct of HTGR

    International Nuclear Information System (INIS)

    Peng Wei; Zhen Ya'nan; Yang Xiaoyong; Ye Ping

    2013-01-01

    The behavior of the graphite dust is important to the safety of high-temperature gas-cooled reactor (HTGR). The temperature field in hot gas duct was obtained using computational fluid dynamics (CFD) method. Further analysis to the thermo-phoretic deposition and turbulent deposition shows that as the dust particle diameter increases, the thermo-phoretic deposition efficiency decreases, and the turbulent deposition efficiency initially decreases and then increases. The comparisons of calculation results for two reactor powers, namely 30% FP (full power) and 100 % FP, indicate that the thermo-phoretic deposition efficiency is higher at 30% FP than that at 100% FP. while the turbulent deposition efficiency grows more rapidly at 100% FP. Besides, the results also demonstrate that the thermo-phoretic deposition and the turbulent deposition are nearly equivalent when particle sizes are small, while the turbulent deposition becomes dominant when particle sizes are fairly large. The calculation results by using the most probable distribution of particle size show that the total deposition of graphite dusts in hot gas duct is limited. (authors)

  8. Preliminary design analysis of hot gas ducts and a intermediate heat exchanger for the nuclear hydrogen reactor

    International Nuclear Information System (INIS)

    Song, K. N.; Kim, Y. W.

    2008-01-01

    Korea Atomic Energy Research Institute (KAERI) is in the process of carrying out a nuclear hydrogen system by considering the indirect cycle gas cooled reactors that produce heat at temperatures in the order of 950 .deg. C. Primary and secondary hot gas ducts with coaxial double tubes and are key components connecting a reactor pressure vessel and a intermediate heat exchanger for the nuclear hydrogen system. In this study, preliminary design analyses on the hot gas ducts and the intermediate heat exchanger were carried out. These preliminary design activities include a preliminary design on the geometric dimensions, a preliminary strength evaluation, thermal sizing, and an appropriate material selection

  9. By-pass flows and temperature distribution in a hot gas duct internally insulated by carbon stone

    International Nuclear Information System (INIS)

    Konuk, A.A.

    1979-01-01

    A mathematical model has been developed to calculate by-pass flows and temperature distribution in a hot gas duct internally insulated by carbon stone rings. The equations of conservation of mass and momentum are solved for a piping system to obtain axial and radial by-pass velocities. The energy equation is solved next by a marching method to obtain the radial temperature distribution along the duct. The results, although qualitative due to simplifications in the model, are useful to study the effects of duct geometry on its performance. (Author) [pt

  10. Thermal hydrodynamic modeling and simulation of hot-gas duct for next-generation nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Injun [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Hong, Sungdeok; Kim, Chansoo [Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Bai, Cheolho; Hong, Sungyull [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Shim, Jaesool, E-mail: jshim@ynu.ac.kr [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of)

    2016-12-15

    Highlights: • Thermal hydrodynamic nonlinear model is presented to examine a hot gas duct (HGD) used in a fourth-generation nuclear power reactor. • Experiments and simulation were compared to validate the nonlinear porous model. • Natural convection and radiation are considered to study the effect on the surface temperature of the HGD. • Local Nusselt number is obtained for the optimum design of a possible next-generation HGD. - Abstract: A very high-temperature gas-cooled reactor (VHTR) is a fourth-generation nuclear power reactor that requires an intermediate loop that consists of a hot-gas duct (HGD), an intermediate heat exchanger (IHX), and a process heat exchanger for massive hydrogen production. In this study, a mathematical model and simulation were developed for the HGD in a small-scale nitrogen gas loop that was designed and manufactured by the Korea Atomic Energy Research Institute. These were used to investigate the effect of various important factors on the surface of the HGD. In the modeling, a porous model was considered for a Kaowool insulator inside the HGD. The natural convection and radiation are included in the model. For validation, the modeled external surface temperatures are compared with experimental results obtained while changing the inlet temperatures of the nitrogen working fluid. The simulation results show very good agreement with the experiments. The external surface temperatures of the HGD are obtained with respect to the porosity of insulator, emissivity of radiation, and pressure of the working fluid. The local Nusselt number is also obtained for the optimum design of a possible next-generation HGD.

  11. Structural Pre-sizing of a Coaxial Double-tube Type Hot Gas Duct

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kee Nam; Kim, Y-W [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-10-15

    The nuclear hydrogen system being researched at KAERI is planning to produce hydrogen in the order of 950 .deg. C by using nuclear energy and a thermo-chemical process, and helium gas is tentatively considered as the choice for the coolant. A hot gas duct (HGD) is a key component connecting the reactor pressure vessel and the intermediate heat exchanger (IHX) for the nuclear hydrogen system. The HGD is a unique component exclusively found in an HTR-module concept where a nuclear core and IHX are placed separately into two pressure vessels, which require a connecting duct between them. A coaxial double-tube type cross vessel is considered for the HGD structure of the nuclear hydrogen system because of its successive extensive experience. In this study, a structural pre-sizing for the primary HGD was carried out. These activities include a predecision on the geometric dimensions, a pre-evaluation on the strength, and a pre-selection on the material of the coaxial double-tube type cross vessel components. A predecision on the geometric dimensions was undertaken based on various engineering concepts, such as a constant flow velocity (CFV) model, a constant flow rate (CFR) model, a constant hydraulic head (CHH) model, and finally a heat balanced (HB) model. For the CFV model, CFR model, and CHH model, the HGD structure might be insensitive to a flow induced vibration (FIV) in the case where there are no pressure differences between the hot and cold helium regions. Also we compared the geometric dimensions from the various models.

  12. WAVE PROPAGATION in the HOT DUCT of VHTR

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Nondestructive Evaluation of the J-2X Direct Metal Laser Sintered Gas Generator Discharge Duct

    Science.gov (United States)

    Esther, Elizabeth A.; Beshears, Ronald D.; Lash, Rhonda K.

    2012-01-01

    The J-2X program at NASA's Marshall Space Flight Center (MSFC) procured a direct metal laser sintered (DMLS) gas generator discharge duct from Pratt & Whitney Rocketdyne and Morris Technologies for a test program that would evaluate the material properties and durability of the duct in an engine-like environment. DMLS technology was pursued as a manufacturing alternative to traditional techniques, which used off nominal practices to manufacture the gas generator duct's 180 degree turn geometry. MSFC's Nondestructive Evaluation (NDE) Team performed radiographic, ultrasonic, computed tomographic, and fluorescent penetrant examinations of the duct. Results from the NDE examinations reveal some shallow porosity but no major defects in the as-manufactured material. NDE examinations were also performed after hot-fire testing the gas generator duct and yielded similar results pre and post-test and showed no flaw growth or development.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mallay, Dave [Home Innovation Research Labs, Upper Marlboro, MD (United States)

    2016-01-07

    "9A 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. The primary research question with buried ducts is potential condensation at the outer jacket of the duct insulation in humid climates during the cooling season. Current best practices for buried ducts rely on encapsulating the insulated ducts with closed-cell spray polyurethane foam insulation to control condensation and improve air sealing. The encapsulated buried duct concept has been analyzed and shown to be effective in hot-humid climates. The purpose of this project is to develop an alternative buried duct system that performs effectively as ducts in conditioned space - durable, energy efficient, and cost-effective - in a hot-humid climate (IECC warm-humid climate zone 3A) with three goals that distinguish this project: 1) Evaluation of design criteria for buried ducts that use common materials and do not rely on encapsulation using spray foam or disrupt traditional work sequences; 2) Establishing design criteria for compact ducts and incorporate those with the buried duct criteria to further reduce energy losses and control installed costs; 3) Developing HVAC design guidance for performing accurate heating and cooling load calculations for compact buried ducts.

  15. Two-branch Gas Experiments for Hot Gas Mixing of HTR-PM

    International Nuclear Information System (INIS)

    Zhou Yangping; Hao Pengefei; He Heng; Li Fu; Shi Lei

    2014-01-01

    A model experiment is proposed to investigate the hot gas mixing efficiency of HTR-PM reactor outlet. The test facility is introduced which is set at a scale of 1:2.5 comparing with the design of thermal mixing structure at HTR-PM reactor outlet. The test facility using air as its flow media includes inlet pipe system, electric heaters, main body of test facility, hot gas duct, exhaust pipe system and I&C system. Two-branch gas experiments are conducted on the test facility and the values of thermal-fluid parameters are collected and analyzed which include the temperature, pressure and velocity of the flow as well as the temperature of the tube wall. The analysis result shows the mixing efficiency is higher than the requirement of thermal mixing by steam generator even with conservative assumption which indicates that the design of hog gas mixing structure of HTR-PM fulfills the requirement for thermal mixing at two-branch working conditions. (author)

  16. Transition duct system with straight ceramic liner for delivering hot-temperature gases in a combustion turbine engine

    Science.gov (United States)

    Wiebe, David J.

    2017-05-16

    A transition duct system (10) for delivering hot-temperature gases from a plurality of combustors in a combustion turbine engine is provided. The system includes an exit piece (16) for each combustor. The exit piece may include a straight path segment (26) for receiving a gas flow from a respective combustor. A straight ceramic liner (40) may be inwardly disposed onto a metal outer shell (38) along the straight path segment of the exit piece. Structural arrangements are provided to securely attach the ceramic liner in the presence of substantial flow path pressurization. Cost-effective serviceability of the transition duct systems is realizable since the liner can be readily removed and replaced as needed.

  17. High-Performance Ducts in Hot-Dry Climates

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chitwood, Rick [National Renewable Energy Laboratory (NREL), Golden, CO (United States); German, Alea [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Weitzel, Elizabeth [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    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.

  18. Testing and analyses of a high temperature duct for gas-cooled reactors

    International Nuclear Information System (INIS)

    Black, W.E.; Roberge, A.; Felten, P.; Bastien, D.

    1979-01-01

    A 0.6 scale model of a steam cycle gas-cooled reactor high temperature duct was tested in a closed loop helium facility. The object of the test series was to determine: 1) the thermal effects of gas permeation within the thermal barrier, 2) the plastic deformation of the metallic components, and 3) the thermal performance of the fibrous insulation. A series of tests was performed with thermal cyclings from 100 0 C to 760 0 C at 50 atmospheres until the system thermal performance had stabilized hence enabling predictions for the reactor life. Additional tests were made to assess permeation by deliberately simulating sealing weld failures thereby allowing gas flow by-pass within the primary thermal barrier. After 100 cycles the entire primary structure was found to have performed without structural failure. Due to high pressures exerted by the insulation on the cover plates and a design oversight, the thin seal sheets were unable to expand in an anticipated manner. Local buckling resulted. The insulation retained an acceptable degree of resiliency. However, some fiber damage was observed within both the high and low temperature insulation blankets. A thermal analysis was conducted to correlate the hot duct heat transfer results with those obtained from the analytical techniques used for the HTGR design using a computer thermal model representative of the duct and test setup. The thermal performance of the insulation, the temperature gradient through the structural components, the heating load to the cooling system and the permeation flow effect on heat transfer were verified. Exellent correlation between the experimental data and the analytical techniques were obtained

  19. Hot Gas Halos in Galaxies

    Science.gov (United States)

    Mulchaey, John

    Most galaxy formation models predict that massive low-redshift disk galaxies are embedded in extended hot halos of externally accreted gas. Such gas appears necessary to maintain ongoing star formation in isolated spirals like the Milky Way. To explain the large population of red galaxies in rich groups and clusters, most galaxy evolution models assume that these hot gas halos are stripped completely when a galaxy enters a denser environment. This simple model has been remarkably successful at reproducing many observed properties of galaxies. Although theoretical arguments suggest hot gas halos are an important component in galaxies, we know very little about this gas from an observational standpoint. In fact, previous observations have failed to detect soft X-ray emission from such halos in disk galaxies. Furthermore, the assumption that hot gas halos are stripped completely when a galaxy enters a group or cluster has not been verified. We propose to combine proprietary and archival XMM-Newton observations of galaxies in the field, groups and clusters to study how hot gas halos are impacted by environment. Our proposed program has three components: 1) The deepest search to date for a hot gas halo in a quiescent spiral galaxy. A detection will confirm a basic tenet of disk galaxy formation models, whereas a non-detection will seriously challenge these models and impose new constraints on the growth mode and feedback history of disk galaxies. 2) A detailed study of the hot gas halos properties of field early-type galaxies. As environmental processes such as stripping are not expected to be important in the field, a study of hot gas halos in this environment will allow us to better understand how feedback and other internal processes impact hot gas halos. 3) A study of hot gas halos in the outskirts of groups and clusters. By comparing observations with our suite of simulations we can begin to understand what role the stripping of hot gas halos plays in galaxy

  20. Hinkley Point A gas duct repairs

    International Nuclear Information System (INIS)

    Curtis, R.F.

    1996-01-01

    In 1990, routine visual inspection of the Hinckley Point A Reactor 1 pressure vessel gas outlet ducts showed failures in the welded stud bolts retaining the insulation edging strips. Since the ducts are accessible only from within the pressure vessel, a remote repair technique that could be deployed via the vessel stand pipe had to be found. A drawn arc stud welding and work package formerly used at the Oldbury Power Station was modified for the purpose. The only manipulators with sufficient reach and adequate carrying capacity to deploy the package were the Sizewell SNAKES manipulators. One of these was modified to fit the Hinckley reactor and repairs have been successfully carried out. Similar studs on the gas ducts in Reactor 2, are shielded from visual inspection by a Z-clip feature. A technique using pulsed thermography was developed. The studs were heated for a short time at their exposed ends using a prefocused lamp and the heat decay patterns monitored by an infrared camera enabling attached and detached studs to be distinguished. The inspection package was deployed using the SNAKES manipulator again. In both operations, I-Grip computer modelling was used in the design of the package envelope and the deployment routes. (UK)

  1. First operational tests of an oxycoal hot gas cleaning facility; Erste Betriebstests einer Oxycoal-Heissgasreinigung

    Energy Technology Data Exchange (ETDEWEB)

    Kellermann, A.; Habermehl, M.; Foerster, M.; Kneer, R. [RWTH Aachen University (Germany). Lehrstuhl fuer Waerme- und Stoffuebertragung

    2009-07-01

    An oxyfuel power plant process using a ceramic high temperature membrane for oxygen supply is investigated within the scope of the OXYCOAL-AC project at RWTH Aachen Uni-versity. Implementing the membrane requires a clean gas at a temperature of 850 C. There-fore a hot gas cleaning facility based on porous ceramic candle filters is used, which is state-of-the-art for the gas cleaning of synthesis gas or for flue gas cleaning in pressurised fluid-ised bed furnaces. However, these applications operate at lower temperatures and in a sig-nificantly different atmosphere. Thus, experiences for dust removal at high temperatures in oxyfuel atmoshere are not available. Experiments with a hot gas cleaning facility were con-ducted at the experimental combustion plant of the Institute of Heat and Mass Transfer, us-ing different candle filter materials. The flue gas was provided by a coal fired 100 kW{sub th} oxy-fuel furnace. The operational behaviour of the filtration facility, the adhesion and dedusting properties of the filter cake were investigated. (orig.)

  2. Building America Case Study: Compact Buried Ducts in a Hot-Humid Climate House, Lady's Island, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    2016-02-01

    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. The primary research question with buried ducts is potential condensation at the outer jacket of the duct insulation in humid climates during the cooling season. Current best practices for buried ducts rely on encapsulating the insulated ducts with closed-cell spray polyurethane foam insulation to control condensation and improve air sealing. The encapsulated buried duct concept has been analyzed and shown to be effective in hot-humid climates. The purpose of this project is to develop an alternative buried duct system that performs effectively as ducts in conditioned space - durable, energy efficient, and cost-effective - in a hot-humid climate (IECC warm-humid climate zone 3A) with three goals that distinguish this project: 1) Evaluation of design criteria for buried ducts that use common materials and do not rely on encapsulation using spray foam or disrupt traditional work sequences, 2) Establishing design criteria for compact ducts and incorporate those with the buried duct criteria to further reduce energy losses and control installed costs, and 3) Developing HVAC design guidance for performing accurate heating and cooling load calculations for compact buried ducts.

  3. The Energy Efficiency of Hot Water Production by Gas Water Heaters with a Combustion Chamber Sealed with Respect to the Room

    Directory of Open Access Journals (Sweden)

    Grzegorz Czerski

    2014-08-01

    Full Text Available This paper presents investigative results of the energy efficiency of hot water production for sanitary uses by means of gas-fired water heaters with the combustion chamber sealed with respect to the room in single-family houses and multi-story buildings. Additionally, calculations were made of the influence of pre-heating the air for combustion in the chimney and air supply system on the energy efficiency of hot water production. CFD (Computational Fluid Dynamics software was used for calculation of the heat exchange in this kind of system. The studies and calculations have shown that the use of gas water heaters with a combustion chamber sealed with respect to the room significantly increases the efficiency of hot water production when compared to traditional heaters. It has also been proven that the pre-heating of combustion air in concentric chimney and air supply ducts essentially improves the energy efficiency of gas appliances for hot water production.

  4. New Whole-House Solutions Case Study: Compact Buried Ducts in a Hot-Humid Climate House

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-02-18

    With U.S. Department of Energy Building America Program support, Home Innovation Research Labs partnered with K. Hovnanian Homes to demonstrate a new buried-duct design that is durable, energy efficient, and cost-effective in a hot-humid climate.

  5. Hot fuel gas dedusting after sorbent-based gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    Advanced power generation technologies, such as Air Blown Gasification Cycle (ABGC), require gas cleaning at high temperatures in order to meet environmental standards and to achieve high thermal efficiencies. The primary hot gas filtration process, which removes particulates from the cooled raw fuel gas at up to 600{degree}C is the first stage of gas cleaning prior to desulphurization and ammonia removal processes. The dust concentration in the fuel gas downstream of the sorbent processes would be much lower than for the hot gas filtration stage and would have a lower sulphur content and possibly reduced chlorine concentration. The main aim of this project is to define the requirements for a hot gas filter for dedusting fuel gas under these conditions, and to identify a substantially simpler and more cost effective solution using ceramic or metal barrier filters.

  6. Hot gas cleaning, a targeted project

    Energy Technology Data Exchange (ETDEWEB)

    Romey, I. [University of Essen, Essen (Germany)

    1998-11-01

    Advanced hot gas cleaning systems will play a key role in future integrated combined cycle technologies. IGCC demonstration plants in operation or under construction are at present equipped with conventional wet gas scrubbing and cleaning systems. Feasibility studies for those IGCC plants have shown that the total efficiency of the processes can be improved using hot gas cleaning systems. However, this technology has not been developed and tested at a technical scale. Six well-known European industrial companies and research centres jointly worked together since January 1996 on a Targeted Project `Hot Gas Cleaning` to investigate and develop new hot gas cleaning systems for advanced clean coal power generation processes. In addition project work on chemical analysis and modelling was carried out in universities in England and Germany. The latest main findings were presented at the workshop. The main project aims are summarised as follows: to increase efficiency of advanced power generation processes; to obtain a reduction of alkalis and environmental emissions e.g. SO{sub 2}, NO{sub x}, CO{sub 2} and dust; and to develop the design basis for future industrial plants based on long-term operation of laboratory, pilot and demo-plants. To cover a range of possible process routes for future hot gas cleaning systems the following research programme is under investigation: removal of trace elements by different commercial and self developed sorbents; gas separation by membranes; separation of gas turbine relevant pollutants by hot filter dust and; H{sub 2}S removal and gas dedusting at high temperatures. 13 figs.

  7. HOT GAS HALOS IN EARLY-TYPE FIELD GALAXIES

    International Nuclear Information System (INIS)

    Mulchaey, John S.; Jeltema, Tesla E.

    2010-01-01

    We use Chandra and XMM-Newton to study the hot gas content in a sample of field early-type galaxies. We find that the L X -L K relationship is steeper for field galaxies than for comparable galaxies in groups and clusters. The low hot gas content of field galaxies with L K ∼ * suggests that internal processes such as supernovae-driven winds or active galactic nucleus feedback expel hot gas from low-mass galaxies. Such mechanisms may be less effective in groups and clusters where the presence of an intragroup or intracluster medium can confine outflowing material. In addition, galaxies in groups and clusters may be able to accrete gas from the ambient medium. While there is a population of L K ∼ * galaxies in groups and clusters that retain hot gas halos, some galaxies in these rich environments, including brighter galaxies, are largely devoid of hot gas. In these cases, the hot gas halos have likely been removed via ram pressure stripping. This suggests a very complex interplay between the intragroup/intracluster medium and hot gas halos of galaxies in rich environments, with the ambient medium helping to confine or even enhance the halos in some cases and acting to remove gas in others. In contrast, the hot gas content of more isolated galaxies is largely a function of the mass of the galaxy, with more massive galaxies able to maintain their halos, while in lower mass systems the hot gas escapes in outflowing winds.

  8. Hot-film anemometer measurements in adiabatic two-phase flow through a vertical duct

    International Nuclear Information System (INIS)

    Trabold, T.A.; Moore, W.E.; Morris, W.O.

    1997-06-01

    A hot-film anemometer (HFA) probe was used to obtain local measurements of void fraction and bubble frequency in a vertically oriented, high aspect ratio duct containing R-134a under selected adiabatic two-phase flow conditions. Data were obtained along a narrow dimension scan over the range 0.03 ≤ bar Z ≤ 0.80, where bar Z is the distance from the wall normalized with the duct spacing dimension. The void fraction profiles displayed large gradients in the near-wall regions and broad maxima near the duct centerline. The trends in the bubble frequency data generally follow those for the local void fraction data. However, the relatively large number of bubbles at higher pressure implies a larger magnitude of the interfacial area concentration, for the same cross-sectional average void fraction. For the two annular flow conditions tested, analysis of the HFA output voltage signal enabled identification of three distinct regions of the flow field; liquid film with dispersed bubbles, interfacial waves, and continuous vapor with dispersed droplets

  9. Pulsatile pressure driven rarefied gas flow in long rectangular ducts

    Science.gov (United States)

    Tsimpoukis, Alexandros; Valougeorgis, Dimitris

    2018-04-01

    The pulsatile pressure driven fully developed flow of a rarefied gas through an orthogonal duct is investigated, based on the time-dependent linear Bhatnagar, Gross, and Krook equation, by decomposing the flow into its steady and oscillatory parts. The investigation is focused on the oscillatory part, which is characterized by the gas rarefaction and oscillation parameters, the duct aspect ratio, and the accommodation coefficient. As the oscillation frequency is increased, the amplitude of all macroscopic quantities is decreased, while their phase angle lag is increased reaching the limiting value of π/2. As the gas becomes more rarefied, higher frequencies are needed to trigger this behavior. At small and moderate frequencies, there is a critical degree of gas rarefaction, where a maximum flow rate is obtained. As the duct aspect ratio is decreased and tends to zero, the flow rate and mean wall shear stress amplitudes are increased, while their phase angle lags are slightly affected. The accommodation coefficient has a significant effect on the amplitude and a very weak one on the phase angle of the macroscopic quantities. The computation of the inertia and viscous forces clarifies when the flow consists of only one oscillating viscous region or of two regions, namely, the inviscid piston flow in the core and the oscillating Stokes layer at the wall with the velocity overshooting. Finally, the time average oscillatory pumping power is increased as the oscillation frequency is reduced and its maximum value is one half of the corresponding steady one.

  10. Ducted fuel injection

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Charles J.

    2018-03-06

    Various technologies presented herein relate to enhancing mixing inside a combustion chamber to form one or more locally premixed mixtures comprising fuel and charge-gas with low peak fuel to charge-gas ratios to enable minimal, or no, generation of soot and other undesired emissions during ignition and subsequent combustion of the locally premixed mixtures. To enable sufficient mixing of the fuel and charge-gas, a jet of fuel can be directed to pass through a bore of a duct causing charge-gas to be drawn into the bore creating turbulence to mix the fuel and the drawn charge-gas. The duct can be located proximate to an opening in a tip of a fuel injector. The duct can comprise of one or more holes along its length to enable charge-gas to be drawn into the bore, and further, the duct can cool the fuel and/or charge-gas prior to combustion.

  11. Study on Gas Field Optimization Distribution with Parameters Adjustment of the Air Duct Outlet for Mechanized Heading Face in Coal Mine

    Science.gov (United States)

    Gong, Xiao-Yan; Zhang, Xin-Yi; Wu, Yue; Xia, Zhi-Xin; Li, Ying

    2017-12-01

    At present, as the increasingly drilling dimensions with cross-section expansion and distance prolong in coal mine, the situation of gas accumulation in mechanized heading face becomes severe. In this paper, optimization research of gas distribution was carried out by adjusting parameters of the air duct outlet, including angle, caliber and the front and rear distance of air duct outlet. Mechanized heading face of Ningtiaota coal mine was taken as the research object, simulated and analyzed the problems of original gas field, the reasonable parameters range of the air duct outlet was determined according to the allowable range of wind speed and the effect of gas dilution, the adjustment range of each parameter of the air duct outlet is preliminarily determined. Base on this, the distribution of gas field under different parameters adjustment of air duct outlet was simulated. The specific parameters under the different distance between the air duct outlet and the mechanized heading face were obtained, and a new method of optimizing the gas distribution by adjusting parameters of the air duct outlet was provided.

  12. A model for pressure in an LMFBR duct due to discharge of gas from a failed fuel pin

    International Nuclear Information System (INIS)

    Srinivas, S.; Chopra, P.S.

    1977-01-01

    In this paper an analytical model for the calculation of pressure pulses in hexagonal ducts due to discharge of gas from a failed fuel pin is developed. The analysis yields the time history of the pressure pulse which can be used in the calculation of permanent deformation of the duct or in the assessment of the susceptibility of the duct to fracture. The real physical situation of gas discharging through a pin in a duct filled with liquid is complex to model. Here the phenomenon is modeled based on some reasonable assumptions. In this model the analysis is divided into two stages. In the first stage the gas expands as a spherical bubble, but the influence of the duct wall is taken into account. At the end of the first stage the spherical shape of the bubble is assumed to be lost and the gas is assumed to expand axially as a column. The analysis involves solving the continuity and momentum equations for the liquid along with the energy balance equation for the gas

  13. The natural gas ducts and the ICMS; Os dutos de gas natural e o ICMS

    Energy Technology Data Exchange (ETDEWEB)

    Galvao, Rafael Silva Paes Pires; Silveira Neto, Otacilio dos Santos; Gomes, Carlos Roberto de Miranda [Rio Grande do Norte Univ., Natal, RN (Brazil). Programa de Recursos Humanos da ANP para o Setor Petroleo e Gas, PRH-36

    2005-07-01

    With the advent of the Constitutional Emendation no. 9/95 operated it the open of the industry of the oil and the natural gas for companies others that came to be contracted by the State. Ahead of the insertion of new players, the regulation of the sector was given for the Law (no. 9.478/97), as well for legal acts edited for the National Agency of the Oil - ANP. Meanwhile, the Oil norm little disciplined the industry of the natural gas that, for its peculiarities, imposes specific rules. In this context, the transport of the natural gas by means of ducts become prominent for the lack of debates on the correct form to classify them. The present work has for target to analyze the legal types instituted by the Law and for the ANP acts for the ducts, as form of if having a correct understanding of the matter. Thus, will reveal as each one of the adopted classifications can cause (or not) the incidence of the ICMS, or either, as the legal regimen of the gas-lines is correlated with the tax. (author)

  14. Hot gas path component having near wall cooling features

    Science.gov (United States)

    Miranda, Carlos Miguel; Kottilingam, Srikanth Chandrudu; Lacy, Benjamin Paul

    2017-11-28

    A method for providing micro-channels in a hot gas path component includes forming a first micro-channel in an exterior surface of a substrate of the hot gas path component. A second micro-channel is formed in the exterior surface of the hot gas path component such that it is separated from the first micro-channel by a surface gap having a first width. The method also includes disposing a braze sheet onto the exterior surface of the hot gas path component such that the braze sheet covers at least of portion of the first and second micro-channels, and heating the braze sheet to bond it to at least a portion of the exterior surface of the hot gas path component.

  15. Organic lining materials test in flue gas ducts

    International Nuclear Information System (INIS)

    Raveh, R.; Sfez, D.; Johannsson, L.

    1998-01-01

    Corrosion protection solutions are being widely used in electric power plants equipped with Flue Gas Desulfurization (FGD) systems. Organic lining materials are one of many solutions available on the market for corrosion protection. This market segment is found in a continuous development in order to fulfill the severe demands of these materials. The main goal of this test is to obtain information about the high temperature resistance of the materials as occurs when the FGD system is by-passed. Aster initial investigation of this market segment only a few lining materials were found compatible according to their manufacturer data. Seven of these materials were installed in the outlet flue gas duct of the Israeli power station M.D. B. This power station is not equipped with a FGD system, thus it gives a real simulation of the environmental conditions into which the lining material is subjected when the FGD system is by-passed. The materials installation was observed carefully and performed by representatives from the manufacturers in order to avoid material failure due to a non-adequate application. The power station was shut down and the lining materials were inspected three and a half months after the lining materials were applied. The inspection results were good and besides changes in the lining color, most materials did not show any damages. During that time the flue gas temperature at the duct was 134?C except some temperature fluctuations

  16. Transition duct system with arcuate ceramic liner for delivering hot-temperature gases in a combustion turbine engine

    Energy Technology Data Exchange (ETDEWEB)

    Wiebe, David J.

    2017-11-07

    A transition duct system (10) for delivering hot-temperature gases from a plurality of combustors in a combustion turbine engine is provided. The system includes an exit piece (16) for each combustor. The exit piece may include an arcuate connecting segment (36). An arcuate ceramic liner (60) may be inwardly disposed onto a metal outer shell (38) along the arcuate connecting segment of the exit piece. Structural arrangements are provided to securely attach the ceramic liner in the presence of substantial flow path pressurization. Cost-effective serviceability of the transition duct systems is realizable since the liner can be readily removed and replaced as needed.

  17. The open access and the natural gas ducts: transport and distribution; O livre acesso e os dutos de gas natural: transporte e distribuicao

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, Mariana de; Xavier, Yanko Marcius de Alencar [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    The present research, attempting for the economic relevance of the natural gas sector, for the lack of a law that disciplines it and, still, for the structural question of the natural gas ducts activities; it analyzes, in a comparative way, the monopoly of the natural gas ducts activities and the mechanisms of competition chosen to brighten up it: the open access and the by pas. The transport and the distribution of the natural gas are really similar, but the ways to insert the competition in its areas are not. (author)

  18. Hot-Gas Filter Ash Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, M.L.; Hurley, J.P.; Dockter, B.A.; O`Keefe, C.A.

    1997-07-01

    Large-scale hot-gas filter testing over the past 10 years has revealed numerous cases of cake buildup on filter elements that has been difficult, if not impossible, to remove. At times, the cake can blind or bridge between candle filters, leading to filter failure. Physical factors, including particle-size distribution, particle shape, the aerodynamics of deposition, and system temperature, contribute to the difficulty in removing the cake, but chemical factors such as surface composition and gas-solid reactions also play roles in helping to bond the ash to the filters or to itself. This project is designed to perform the research necessary to determine the fuel-, sorbent-, and operations-related conditions that lead to blinding or bridging of hot-gas particle filters. The objectives of the project are threefold: (1) Determine the mechanisms by which a difficult-to-clean ash is formed and how it bridges hot-gas filters (2) Develop a method to determine the rate of bridging based on analyses of the feed coal and sorbent, filter properties, and system operating conditions and (3) Suggest and test ways to prevent filter bridging.

  19. Gas turbine exhaust system silencing design

    International Nuclear Information System (INIS)

    Ozgur, D.

    1991-01-01

    Gas turbines are the preferred prime mover in many applications because of their high efficiency, fuel flexibility, and low environmental impact. A typical mid-size machine might have a power rating of 80 MW, a flow of about 1000 kg/hr, and an exhaust temperature of over 500C. The most powerful single source of noise is generally the exhaust, which may generate over a kilowatt of acoustic energy. This paper reports that there are two important ways in which exhaust systems can radiate noise. The first is through the discharge of the exhaust duct, with the exhaust gas. Because of the large quantity of hot gas, the duct exit is always oriented vertically; it may be fairly high in the air in order to promote dispersion of the exhaust plume. This source is almost always attenuated by means of a silencer located somewhere in the ductwork. The second source of noise is often called breakout; it is the radiation of exhaust noise through the walls of the ducting. Breakout is most important for those sections of the exhaust duct which lie upstream of the silencer, where sound levels inside the ducting are highest. Both exhaust duct exit noise and breakout noise can be calculated from the sound power level of the gas turbine exhaust and the sound transmission loss (TL) of the silencer and ducting

  20. Venting of gas deflagrations through relief pipes

    OpenAIRE

    Ferrara, Gabriele

    2006-01-01

    Vent devices for gas and dust explosions are often ducted to safety locations by means of relief pipes for the discharge of hot combustion products or blast waves (NFPA 68, 2002). The presence of the duct is likely to increase the severity of the explosion with respect to simply vented vessels posing a problem for the proper design of this venting configuration. The phenomenology of the vented explosion is complicated as the interaction of combustion in the duct with primary combustion in...

  1. A model for dry sodium bicarbonate duct injection flue gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Changfa Wu; Soon-Jai Khang; Tim C. Keener; Sang-Kwun Lee [University of Cincinnati, Cincinnati, OH (United States). Department of Chemical Engineering

    2004-03-01

    A mathematical model is developed for simulation of dry sodium bicarbonate (NaHCO{sub 3}) duct injection for the removal of sulfur dioxide (SO{sub 2}) in flue gases across a fabric filter (baghouse). The model employs parallel reaction kinetics and assumes that the sodium bicarbonate injection process can be separated into two stages. The first stage is a transport duct section where NaHCO{sub 3} particles are injected into the sulfur dioxide laden gas stream. The second stage is the fabric filter section where sodium sorbents are collected and behave as a variable depth fixed bed reactor. The process simulation for the efficiency of desulfurization in flue gas is performed and evaluated for a variety of operating conditions. It is found that the removal of SO{sub 2} within the duct section is small and negligible for most practical conditions, with a contribution normally less than 5% of total SO{sub 2} removal. The major removal of SO{sub 2} occurs across the filter cake, which accumulates the sorbent particles on the fabric filter. These particles are periodically disposed as the filter is cleaned. The major factors for the process are temperature, particle size and SO{sub 2} gas concentration for all operating conditions. At low temperatures, the removal of SO{sub 2} increases as temperature increases, but the removal decreases at higher temperatures due to the impact of the thermal decomposition reaction of NaHCO{sub 3} on SO{sub 2} removal. It was found that the temperature for the highest removal of SO{sub 2} is within the range of 127-150{sup o}C and the removal efficiency also depends on particle size.

  2. Biomass gasification hot gas cleanup for power generation

    Energy Technology Data Exchange (ETDEWEB)

    Wiant, B.C.; Bachovchin, D.M. [Westinghouse Electric Corp., Orlando, FL (United States); Carty, R.H.; Onischak, M. [Institute of Gas Technology, Chicago, IL (United States); Horazak, D.A. [Gilbert/Commonwealth, Reading, PA (United States); Ruel, R.H. [The Pacific International Center for High Technology Research, Honolulu, HI (United States)

    1993-12-31

    In support of the US Department of Energy`s Biomass Power Program, a Westinghouse Electric led team consisting of the Institute of Gas Technology (IGT), Gilbert/Commonwealth (G/C), and the Pacific International Center for High Technology Research (PICHTR), is conducting a 30 month research and development program. The program will provide validation of hot gas cleanup technology with a pressurized fluidized bed, air-blown, biomass gasifier for operation of a gas turbine. This paper discusses the gasification and hot gas cleanup processes, scope of work and approach, and the program`s status.

  3. Tracer gas dispersion in ducts-study of a new compact device using arrays of sonic micro jets

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.R. [Instituto Nacional de Engenharia e Tecnologia Industrial (INETI), Lisboa (Portugal); Afonso, C.F. [Faculdade de Engenharia, Universidade do Porto Departmento de Mecanica e Gestao Industrial, Porto (Portugal)

    2004-07-01

    One of the most feasible ways to measure duct airflows is by tracer gas techniques, especially for complex situations when the duct lengths are short as well as their access, which makes extremely difficult or impossible other methods to be implemented. One problem associated with the implementation of tracer gas technique when the ducts lengths are short is due to the impossibility of achieving complete mixing of the tracer with airflow and its sampling. In this work, the development of a new device for the injection of tracer gas in ducts is discussed as well as a new tracer-sampling device. The developed injection device has a compact tubular shape, with magnetic fixation to be easy to apply in duct walls. An array of sonic micro jets in counter current direction, with the possibility of angular movement according to its main axle ensures a complete mixing of the tracer in very short distances. The tracer-sampling device, with a very effective integration function, feeds the sampling system for analysis. Both devices were tested in a wind tunnel of approximately 21 m total length. The tests distances between injection and integration device considered were: X/Dh = 22; X/Dh = 4; X/Dh 2; and X/Dh = 1. For very short distances of X/Dh = 2 and X/Dh = 1, semi-empirical expressions were needed. A good reproducibility of airflow rate values was obtained. These preliminary tests showed that the practical implementation of tracer gas techniques in HVAC systems for measuring airflow rates with a very short mixing distance is possible with the devices developed. (author)

  4. Evolution of Hot Gas in Elliptical Galaxies

    Science.gov (United States)

    Mathews, William G.

    2004-01-01

    This theory grant was awarded to study the curious nature, origin and evolution of hot gas in elliptical galaxies and their surrounding groups. Understanding the properties of this X-ray emitting gas has profound implications over the broad landscape of modern astrophysics: cosmology, galaxy formation, star formation, cosmic metal enrichment, galactic structure and dynamics, and the physics of hot gases containing dust and magnetic fields. One of our principal specific objectives was to interpret the marvelous new observations from the XMM and Chandru satellite X-ray telescopes.

  5. Integrated hot fuel gas cleaning for advanced gasification combined cycle process

    Energy Technology Data Exchange (ETDEWEB)

    Nieminen, M.; Kangasmaa, K.; Laatikainen, J.; Staahlberg, P.; Kurkela, E. [VTT Energy, Espoo (Finland). Gasification and Advanced Combustion

    1996-12-01

    The fate of halogens in pressurised fluidized-bed gasification and hot gas filtration is determined. Potential halogen removal sorbents, suitable for integrated hot gas cleaning, are screened and some selected sorbents are tested in bench scale. Finally, halogen removal results are verified using the PDU-scale pressurised fluidized-bed gasification and integrated hot gas cleaning facilities of VTT. The project is part of the JOULE II Extension programme of the European Union. (author)

  6. Gas-heating alternatives to the residential electric heat pump. Gas Appliance Technology Center 1987 program. Topical report for Work Area 1.1, October 1989-March 1990

    International Nuclear Information System (INIS)

    Haas, C.

    1990-05-01

    The characteristics of electric heat pumps are described. Options are defined and assessed for utilizing gas heating in conjunction with existing residential electric heat pumps. These options include gas heat introduced into the refrigeration circuit, a flue gas-heated tube bank in the air supply duct, and a hot-water-to-air coil in the supply duct. Economics are presented for conversion of a residence's total space and water heating from electric to gas in New York City and Atlanta. Potential marketing strategies are discussed, and potential gas sales volumes from conversions are estimated. The study concludes that the use of gas water heating coupled with a hydronic coil in the supply ductwork from the air handler is the most advantageous option for the gas industry

  7. Effect of gas release in hot molding on flexural strength of composite friction brake

    Science.gov (United States)

    Rusdja, Andy Permana; Surojo, Eko; Muhayat, Nurul; Raharjo, Wijang Wisnu

    2018-02-01

    Composite friction brake is a vital part of braking system which serves to reduce the speed of vehicle. To fulfill the requirement of brake performance, composite friction brake must have friction and mechanical characteristic as required. The characteristics of composite friction brake are affected by brake material formulation and manufacturing parameter. In the beginning of hot molding, intermittent hot pressing was carried out to release the gases that consist of ammonia gas and water vapor. In composite friction brake, phenolic resin containing hexamethylenetetramine (HMTA) is often used as a binder. During hot molding, the reaction of phenolic resin and HMTA forms ammonia gas. Hot molding also generates water vapor because raw materials absorb moisture from environment when they are placed in storage. The gas release in hot molding is supposed affecting mechanical properties because it avoid entrapped gas in composite, so that this research investigated effect of gas release on flexural strength. Manufacturing of composite specimen was carried out as follow: mixing of raw materials, cold molding, and hot molding. In this research, duration of intermittent hot pressing and number of gas release were varied. The flexural strength of specimen was measured using three point bending test. The results showed that flexural strength specimens that were manufactured without gas release, using 4 times gas release with intermittent hot pressing for 5 and 10 seconds were not remarkably different. Conversely, hot molding using 4 times gas release with intermittent hot pressing for 15 seconds decreased flexural strength of composite. Hot molding using 2, 4, and 8 times gas release with intermittent hot pressing for 10 seconds also had no effect on increasing flexural strength. Increasing of flexural strength of composite was obtained only by using 6 times gas release with intermittent hot pressing for 10 seconds.

  8. Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas Systems

    International Nuclear Information System (INIS)

    Soelberg, Nick; Enneking, Joe

    2011-01-01

    Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and mixed (radioactive and hazardous) wastes. Test programs performed in recent years have shown that mercury in off-gas streams from processes that treat radioactive wastes can be controlled using fixed beds of activated sulfur-impregnated carbon, to levels low enough to comply with air emission regulations such as the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards. Carbon bed hot spots or fires have occurred several times during these tests, and also during a remediation of tanks that contained mixed waste. Hot spots occur when localized areas in a carbon bed become heated to temperatures where oxidation occurs. This heating typically occurs due to heat of absorption of gas species onto the carbon, but it can also be caused through external means such as external heaters used to heat the carbon bed vessel. Hot spots, if not promptly mitigated, can grow into bed fires. Carbon bed hot spots and fires must be avoided in processes that treat radioactive and mixed waste. Hot spots are detected by (a) monitoring in-bed and bed outlet gas temperatures, and (b) more important, monitoring of bed outlet gas CO concentrations. Hot spots are mitigated by (a) designing for appropriate in-bed gas velocity, for avoiding gas flow maldistribution, and for sufficient but not excessive bed depth, (b) appropriate monitoring and control of gas and bed temperatures and compositions, and (c) prompt implementation of corrective actions if bed hot spots are detected. Corrective actions must be implemented quickly if bed hot spots are detected, using a graded approach and sequence starting with corrective actions that are simple, quick, cause the least impact to the process, and are easiest to recover from.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mallay, D. [Home Innovation Research Labs, Upper Marlboro, MD (United States)

    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.

  10. Advanced sulfur control concepts for hot gas desulfurization technology

    International Nuclear Information System (INIS)

    1998-01-01

    The objective of this project is to develop a hot-gas desulfurization process scheme for control of H 2 S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct. The Direct Sulfur Recovery Process (DSRP), a leading process for producing an elemental sulfur byproduct in hot-gas desulfurization systems, incurs a coal gas use penalty, because coal gas is required to reduce the SO 2 in regeneration off-gas to elemental sulfur. Alternative regeneration schemes, which avoid coal gas use and produce elemental sulfur, will be evaluated. These include (i) regeneration of sulfided sorbent using SO 2 ; (ii) partial oxidation of sulfided sorbent in an O 2 starved environment; and (iii) regeneration of sulfided sorbent using steam to produce H 2 S followed by direct oxidation of H 2 S to elemental sulfur. Known regenerable sorbents will be modified to improve the feasibility of the above alternative regeneration approaches. Performance characteristics of the modified sorbents and processes will be obtained through lab- and bench-scale testing. Technical and economic evaluation of the most promising processes concept(s) will be carried out

  11. Physics of dust grains in hot gas

    International Nuclear Information System (INIS)

    Draine, B.T.; Salpeter, E.E.

    1979-01-01

    Charging of dust grains in hot (10 4 --10 9 K) plasma is studied, including photoelectron and secondary electron emission, field emission, and transmission of electrons and ions through the grain; resulting grain potentials are (for T > or approx. = 10 5 K) considerably smaller in magnitude than found by Burke and Silk. Even so, large electrostatic stresses can cause ion field emission and rapid destruction of small grains in very hot gas. Rapid rotation can also disrupt small grains, but damping (by microwave emission) usually limits the centrifugal stress to acceptable values for plasma densities n/sub H/ -3 . Sputtering rates are estimated for grains in hot gas, based upon a semiempirical fit to experimental data. Predicted sputtering rates for possible grain constituents are similar to estimates by Barlow, but in some cases differ significantly. Useful approximation formulae are given for the drag forces acting on a grain with arbitrary Mach number

  12. BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

    International Nuclear Information System (INIS)

    Unknown

    2000-01-01

    The U.S. Department of Energy (DOE), National Energy Technology Laboratory (NETL), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal-derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn(sub 2)TiO(sub 4) or ZnTiO(sub 3)), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO(sub 2)), is currently one of the leading sorbents. Overall chemical reactions with Zn(sub 2)TiO(sub 4) during the desulfurization (sulfidation)-regeneration cycle are shown. The sulfidation/regeneration cycle can be carried out in a fixed-bed, moving-bed, or fluidized-bed reactor configuration. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the highly exothermic regeneration to produce a regeneration offgas containing a constant concentration of SO(sub 2)

  13. BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

    International Nuclear Information System (INIS)

    Unknown

    1999-01-01

    The U.S. Department of Energy (DOE), National Energy Technology Laboratory (NETL), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal-derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn(sub 2)TiO(sub 4) or ZnTiO(sub 3)), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO(sub 2)), is currently one of the leading sorbents. Overall chemical reactions with Zn(sub 2)TiO(sub 4) during the desulfurization (sulfidation)-regeneration cycle are shown. The sulfidation/regeneration cycle can be carried out in a fixed-bed, moving-bed, or fluidized-bed reactor configuration. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the highly exothermic regeneration to produce a regeneration offgas containing a constant concentration of SO(sub 2)

  14. Mechanical design and testing of a hot-gas turbine on a test facility

    International Nuclear Information System (INIS)

    Staude, R.

    1981-01-01

    Advanced calculation methods and specific solutions for any particular problem are basic requirements for the mechanical design of hot-gas components for gas turbines. The mechanical design contributes a great deal to the smooth running and operational reliability and thus to the quality of the machine. By reference to an expander, the present paper discusses the strength of hot components, such as the casing and the rotor, for both stationary and transient temperature distribution. Mechanical testing under hot-gas conditions fully confirmed the reliability of the rating and design of the hot-gas turbines supplied by M:A.N.-GHH STERKRADE. (orig.) [de

  15. Control apparatus for hot gas engine

    Science.gov (United States)

    Stotts, Robert E.

    1986-01-01

    A mean pressure power control system for a hot gas (Stirling) engine utilizing a plurality of supply tanks for storing a working gas at different pressures. During pump down operations gas is bled from the engine by a compressor having a plurality of independent pumping volumes. In one embodiment of the invention, a bypass control valve system allows one or more of the compressor volumes to be connected to the storage tanks. By selectively sequencing the bypass valves, a capacity range can be developed over the compressor that allows for lower engine idle pressures and more rapid pump down rates.

  16. Partial oxidation process for producing a stream of hot purified gas

    Science.gov (United States)

    Leininger, T.F.; Robin, A.M.; Wolfenbarger, J.K.; Suggitt, R.M.

    1995-03-28

    A partial oxidation process is described for the production of a stream of hot clean gas substantially free from particulate matter, ammonia, alkali metal compounds, halides and sulfur-containing gas for use as synthesis gas, reducing gas, or fuel gas. A hydrocarbonaceous fuel comprising a solid carbonaceous fuel with or without liquid hydrocarbonaceous fuel or gaseous hydrocarbon fuel, wherein said hydrocarbonaceous fuel contains halides, alkali metal compounds, sulfur, nitrogen and inorganic ash containing components, is reacted in a gasifier by partial oxidation to produce a hot raw gas stream comprising H{sub 2}, CO, CO{sub 2}, H{sub 2}O, CH{sub 4}, NH{sub 3}, HCl, HF, H{sub 2}S, COS, N{sub 2}, Ar, particulate matter, vapor phase alkali metal compounds, and molten slag. The hot raw gas stream from the gasifier is split into two streams which are separately deslagged, cleaned and recombined. Ammonia in the gas mixture is catalytically disproportionated into N{sub 2} and H{sub 2}. The ammonia-free gas stream is then cooled and halides in the gas stream are reacted with a supplementary alkali metal compound to remove HCl and HF. Alkali metal halides, vaporized alkali metal compounds and residual fine particulate matter are removed from the gas stream by further cooling and filtering. The sulfur-containing gases in the process gas stream are then reacted at high temperature with a regenerable sulfur-reactive mixed metal oxide sulfur sorbent material to produce a sulfided sorbent material which is then separated from the hot clean purified gas stream having a temperature of at least 1000 F. 1 figure.

  17. Radiation resistant ducted superconductive coil

    International Nuclear Information System (INIS)

    Schleich, A.

    1976-01-01

    The radiation-resistant ducted superconductive coil consists of a helically wound electrical conductor constituted by an electrically conductive core of superconductive material provided with a longitudinally extending cooling duct. The core is covered with a layer of inorganic insulating material and the duct is covered by an electrically conductive metallic gas-tight sheath. The metallic sheaths on adjacent turns of the coil are secured together. 2 Claims, 4 Drawing Figures

  18. Dual fan, dual-duct system meets air quality, energy-efficiency needs

    Energy Technology Data Exchange (ETDEWEB)

    Schuler, M. [Pageau Morel and Associates, Montreal, Quebec (Canada)

    1996-03-01

    Canada`s Space Centre in Saint-Hubert Quebec is a 300,000 ft{sup 2} (27,871 m{sup 2}) complex that houses the headquarters of the Canadian Space Agency, the Canadian Astronaut Training Centre, mission ground control installations, research facilities, offices and the required support facilities. A comfortable, pleasant research environment was a primary concern for the Space Centre, given its elite clientele. The objectives were high indoor-air quality, design flexibility, energy efficiency and low capital costs. Dual duct systems which are the heart of the mechanical concept allowed the designers to meet these objectives. The Space Centre`s offices, laboratories and conference center are all served by dual-duct systems. All operate using an air economizer cycle. Gas boilers provide them with hot water for heating and steam for humidification while centrifugal chillers provide chilled water for cooling. This article describes the design.

  19. Surprisingly low natural gas consumption for hot water in the Netherlands in 1996

    International Nuclear Information System (INIS)

    Geerse, C.

    1997-01-01

    The Dutch use hot water more efficient than previously expected. This conclusion is drawn from a recent study of hot water consumption in Dutch households and the corresponding natural gas consumption. Based on that (once-only) hot water use survey the hot water use models, as applied in the annual Basic Survey of Natural Gas Consumption of Small-scale Consumers in the Netherlands (BAK), will be modified. 6 tabs

  20. The co-existence of hot and cold gas in debris discs

    Science.gov (United States)

    Rebollido, I.; Eiroa, C.; Montesinos, B.; Maldonado, J.; Villaver, E.; Absil, O.; Bayo, A.; Canovas, H.; Carmona, A.; Chen, Ch.; Ertel, S.; Garufi, A.; Henning, Th.; Iglesias, D. P.; Launhardt, R.; Liseau, R.; Meeus, G.; Moór, A.; Mora, A.; Olofsson, J.; Rauw, G.; Riviere-Marichalar, P.

    2018-06-01

    Context. Debris discs have often been described as gas-poor discs as the gas-to-dust ratio is expected to be considerably lower than in primordial, protoplanetary discs. However, recent observations have confirmed the presence of a non-negligible amount of cold gas in the circumstellar (CS) debris discs around young main-sequence stars. This cold gas has been suggested to be related to the outgassing of planetesimals and cometary-like objects. Aims: The goal of this paper is to investigate the presence of hot gas in the immediate surroundings of the cold-gas-bearing debris-disc central stars. Methods: High-resolution optical spectra of all currently known cold-gas-bearing debris-disc systems, with the exception of β Pic and Fomalhaut, have been obtained from La Palma (Spain), La Silla (Chile), and La Luz (Mexico) observatories. To verify the presence of hot gas around the sample of stars, we have analysed the Ca II H&K and the Na I D lines searching for non-photospheric absorptions of CS origin, usually attributed to cometary-like activity. Results: Narrow, stable Ca II and/or Na I absorption features have been detected superimposed to the photospheric lines in 10 out of the 15 observed cold-gas-bearing debris-disc stars. Features are found at the radial velocity of the stars, or slightly blue- or red-shifted, and/or at the velocity of the local interstellar medium (ISM). Some stars also present transient variable events or absorptions extended towards red wavelengths (red wings). These are the first detections of such Ca II features in 7 out of the 15 observed stars. Although an ISM origin cannot categorically be excluded, the results suggest that the stable and variable absorptions arise from relatively hot gas located in the CS close-in environment of the stars. This hot gas is detected in at least 80%, of edge-on cold-gas-bearing debris discs, while in only 10% of the discs seen close to face-on. We interpret this result as a geometrical effect, and suggest

  1. Power control system for a hot gas engine

    Science.gov (United States)

    Berntell, John O.

    1986-01-01

    A power control system for a hot gas engine of the type in which the power output is controlled by varying the mean pressure of the working gas charge in the engine has according to the present invention been provided with two working gas reservoirs at substantially different pressure levels. At working gas pressures below the lower of said levels the high pressure gas reservoir is cut out from the control system, and at higher pressures the low pressure gas reservoir is cut out from the system, thereby enabling a single one-stage compressor to handle gas within a wide pressure range at a low compression ratio.

  2. DYNAMIC S0 GALAXIES. II. THE ROLE OF DIFFUSE HOT GAS

    International Nuclear Information System (INIS)

    Li Jiangtao; Chen Yang; Daniel Wang, Q.; Li Zhiyuan

    2011-01-01

    Cold gas loss is thought to be important in star formation quenching and morphological transition during the evolution of S0 galaxies. In high-density environments, this gas loss can be achieved via many external mechanisms. However, in relatively isolated environments, where these external mechanisms cannot be efficient, the gas loss must then be dominated by some internal processes. We have performed Chandra analysis of hot gas in five nearby isolated S0 galaxies, based on the quantitative subtraction of various stellar contributions. We find that all the galaxies studied in the present work are X-ray faint, with the luminosity of the hot gas (L X ) typically accounting for ∼ X at the low-mass end (typically with K-band luminosity L K ∼ 11 L sun,K ). However, at the high-mass end, S0 galaxies tend to have significantly lower L X than elliptical galaxies of the same stellar masses, as already shown in previous observational and theoretical works. We further discuss the potential relationship of the diffuse X-ray emission with the cold (atomic and molecular) gas content in the S0 and elliptical galaxies included in our study. We find that L X /L 2 K tends to correlate positively with the total cold gas mass (M H 2 +H i ) for cold-gas-poor galaxies with M H 2 +H i ∼ 8 M sun , while they anti-correlate with each other for cold-gas-rich galaxies. This cold-hot gas relationship can be explained in a scenario of early-type galaxy evolution, with the leftover cold gas from the precursor star-forming galaxy mainly removed by the long-lasting Type Ia supernova (SN) feedback. The two different trends for cold-gas-rich and cold-gas-poor galaxies may be the results of the initial fast decreasing SN rate and the later fast decreasing mass loading to hot gas, respectively.

  3. Positional Arrangements of Waste Exhaust Gas Ducts of C-Type Balanced Chimney Heating Devices on Building Façades

    Directory of Open Access Journals (Sweden)

    Erkan AVLAR

    2009-01-01

    Full Text Available In Turkey today, with the increase in availability of natural gas,detached heating devices are being preferred over existingheating devices. Due to the lack of chimneys in existing buildingsin Turkey or the presence of chimneys that fail to conformto standards, the use of C-type balanced chimney devices has increased.C-type balanced chimney devices take the combustionair directly from the outside by a specific air duct as detachedheating equipment, with enclosed combustion chambers anda specific waste gas exhaust duct, and they are ventilated independentlyof the field of equipment. Because of their essentiality,the use of a chimney is not required in these devices;the waste gas is exhausted through walls, windows, doors, orbalconies. The natural gas is a clean fossil fuel that requires nostorage in buildings and is easy to use. However, water vapor,carbon dioxide and nitrogen oxides are produced by the combustionof natural gas. It is widely known that high concentrationsof these products can have some adverse effects onhumans such as dizziness, headaches and nausea. As a result,the waste products could recoil through wall openings on thefaçade to create unhealthy indoor environments that could bedangerous to human health. Therefore, the importance of standardsand regulations about the positional arrangements of thewaste gas exhaust ducts of C-type balanced chimney devices onbuilding façades is increasing. In this research, we analyze thestudies of the Institution of Turkish Standards, Chamber of MechanicalEngineers, gas distribution companies, municipalitiesand authorized firms and compare the criteria to determine thenecessary application method. According to our comparison ofthe references accessed, the criteria are not uniform.

  4. BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

    International Nuclear Information System (INIS)

    Unknown

    1999-01-01

    The U.S. Department of Energy (DOE), Federal Energy Technology Center (FETC), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal-derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn(sub 2) TiO(sub 4) or ZnTiO(sub 3)), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO(sub 2)), is currently one of the leading sorbents. Overall chemical reactions with Zn(sub 2) TiO(sub 4) during the desulfurization (sulfidation)-regeneration cycle are shown below: Sulfidation: Zn(sub 2) TiO(sub 4)+ 2H(sub 2)S(yields) 2ZnS+ TiO(sub 2)+ 2H(sub 2)O; Regeneration: 2ZnS+ TiO(sub 2)+ 3O(sub 2)(yields) Zn(sub 2) TiO(sub 4)+ 2SO(sub 2) The sulfidation/regeneration cycle can be carried out in a fixed-bed, moving-bed, or fluidized-bed reactor configuration. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the highly exothermic regeneration to produce a regeneration offgas containing a constant concentration of SO(sub 2)

  5. The Interaction of Hot and Cold Gas in the Disk and Halo of Galaxies

    Science.gov (United States)

    Slavin, Jonathan; Salamon, Michael (Technical Monitor)

    2004-01-01

    Most of the thermal energy in the Galaxy and perhaps most of the baryons in the Universe are found in hot (log T approximately 5.5 - 7) gas. Hot gas is detected in the local interstellar medium, in supernova remnants (SNR), the Galactic halo, galaxy clusters and the intergalactic medium (IGM). In our own Galaxy, hot gas exists in large superbubbles up to several hundred pc in diameter that locally dominate the interstellar medium (ISM) and determine its thermal and dynamic evolution. While X-ray observations using ROSAT, Chandra and XMM have allowed us to make dramatic progress in mapping out the morphology of the hot gas and in understanding some of its spectral characteristics, there remain fundamental questions that are unanswered. Chief among these questions is the way that hot gas interacts with cooler phase gas and the effects these interactions have on hot gas energetics. The theoretical investigations we proposed in this grant aim to explore these interactions and to develop observational diagnostics that will allow us to gain much improved information on the evolution of hot gas in the disk and halo of galaxies. The first of the series of investigations that we proposed was a thorough exploration of turbulent mixing layers and cloud evaporation. We proposed to employ a multi-dimensional hydrodynamical code that includes non-equilibrium ionization (NEI), radiative cooling and thermal conduction. These models are to be applied to high velocity clouds in our galactic halo that are seen to have O VI by FUSE (Sembach et ai. 2000) and other clouds for which sufficient constraining observations exist.

  6. Should you get your heating ducts cleaned?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Canada Mortgage and Housing Corporation conducted research into duct cleaning during which time several houses were tested for hot air furnace duct performance before and after cleaning. Duct cleaning is a major industry which claims that cleaning of ducts will provide you with better indoor air quality, reduce household molds and allergens, get rid of house dust, result in more airflow and better delivery of warm air and reduce energy costs. This report does not substantiate those claims. Researchers found little or no discernible differences in the concentrations of house airborne particles or in duct airflows due to duct cleaning. This is because ducts are metal passages that cannot create dust. Most household dusts come from outdoors that has been tracked in or blows through windows and other openings. While duct cleaning may be justifiable personally, it does not change the quality of the air you breathe, nor will it significantly affect airflow or heating costs. Some filters effectively clean the air in the ducts but they do not create a dust-free environment because of the above-mentioned dust sources. The only time that duct cleaning may make sense is if you have water in your ducts that can result in mold growth, if you are moving into a newly constructed house to remove drywall dust, if your are having trouble with furnace airflow, or if you see an accumulation of debris in the return air ducts. It was emphasized that broadcast spraying of biocides within the duct system should not be performed.

  7. Bench-Scale Demonstration of Hot-Gas Desulfurization Technology

    International Nuclear Information System (INIS)

    Portzer, Jeffrey W.; Gangwal, Santosh K.

    1997-01-01

    Prior to the current project, development of the DSRP was done in a laboratory setting, using synthetic gas mixtures to simulate the regeneration off-gas and coal gas feeds. The objective of the current work is to further the development of zinc titanate fluidized-bed desulfurization (ZTFBD) and the DSRP for hot-gas cleanup by testing with actual coal gas. The objectives of this project are to: (1) Develop and test an integrated, skid-mounted, bench-scale ZTFBD/DSRP reactor system with a slipstream of actual coal gas; (2) Test the bench-scale DSRP over an extended period with a slipstream of actual coal gas to quantify the degradation in performance, if any, caused by the trace contaminants present in coal gas (including heavy metals, chlorides, fluorides, and ammonia); (3) Expose the DSRP catalyst to actual coal gas for extended periods and then test its activity in a laboratory reactor to quantify the degradation in performance, if any, caused by static exposure to the trace contaminants in coal gas; (4) Design and fabricate a six-fold larger-scale DSRP reactor system for future slipstream testing; (5) Further develop the fluidized-bed DSRP to handle high concentrations (up to 14 percent) of SO 2 that are likely to be encountered when pure air is used for regeneration of desulfurization sorbents; and (6) Conduct extended field testing of the 6X DSRP reactor with actual coal gas and high concentrations of SO 2 . The accomplishment of the first three objectives--testing the DSRP with actual coal gas, integration with hot-gas desulfurization, and catalyst exposure testing--was described previously (Portzer and Gangwal, 1994, 1995; Portzer et al., 1996). This paper summarizes the results of previous work and describes the current activities and plans to accomplish the remaining objectives

  8. Mathematical modelling of heat transfer in dedusting plants and comparison to off-gas measurements at electric arc furnaces

    International Nuclear Information System (INIS)

    Kirschen, Marcus; Velikorodov, Viktor; Pfeifer, Herbert

    2006-01-01

    A mathematical simulation tool is presented in order to model enthalpy flow rates of off-gas and heat transfer of cooling systems at dedusting plants in electric steel making sites. The flexibility of the simulation tool is based on a user-defined series of modular units that describe elementary units of industrial dedusting systems, e.g. water-cooled hot gas duct, air injector, drop-out box, mixing chamber, post-combustion chamber, filter, etc. Results of simulation were checked with measurements at industrial electric steel making plants in order to validate the models for turbulence, heat transfer and chemical reaction kinetics. Comparison between computed and measured gas temperature and composition yield excellent agreement. The simulation tool is used to calculate off-gas temperature and volume flow rate, where off-gas measurements are very difficult to apply due to high gas temperatures and high dust load. Heat transfer from the off-gas to the cooling system was calculated in detail for a pressurised hot water EAF cooling system in order to investigate the impact of the cooling system and the dedusting plant operation on the energy sinks of the electric arc furnace. It is shown that optimum efficiency of post-combustion of EAF off-gas in the water-cooled hot gas duct requires continuous off-gas analysis. Common operation parameters of EAF dedusting systems do not consider the non-steady-state of the EAF off-gas emission efficiently

  9. Mathematical modelling of heat transfer in dedusting plants and comparison to off-gas measurements at electric arc furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Kirschen, Marcus [Institute for Industrial Furnaces and Heat Engineering, RWTH Aachen, Kopernikusstrasse 16, 52074 Aachen (Germany)]. E-mail: kirschen@iob.rwth-aachen.de; Velikorodov, Viktor [Institute for Industrial Furnaces and Heat Engineering, RWTH Aachen, Kopernikusstrasse 16, 52074 Aachen (Germany); Pfeifer, Herbert [Institute for Industrial Furnaces and Heat Engineering, RWTH Aachen, Kopernikusstrasse 16, 52074 Aachen (Germany)

    2006-11-15

    A mathematical simulation tool is presented in order to model enthalpy flow rates of off-gas and heat transfer of cooling systems at dedusting plants in electric steel making sites. The flexibility of the simulation tool is based on a user-defined series of modular units that describe elementary units of industrial dedusting systems, e.g. water-cooled hot gas duct, air injector, drop-out box, mixing chamber, post-combustion chamber, filter, etc. Results of simulation were checked with measurements at industrial electric steel making plants in order to validate the models for turbulence, heat transfer and chemical reaction kinetics. Comparison between computed and measured gas temperature and composition yield excellent agreement. The simulation tool is used to calculate off-gas temperature and volume flow rate, where off-gas measurements are very difficult to apply due to high gas temperatures and high dust load. Heat transfer from the off-gas to the cooling system was calculated in detail for a pressurised hot water EAF cooling system in order to investigate the impact of the cooling system and the dedusting plant operation on the energy sinks of the electric arc furnace. It is shown that optimum efficiency of post-combustion of EAF off-gas in the water-cooled hot gas duct requires continuous off-gas analysis. Common operation parameters of EAF dedusting systems do not consider the non-steady-state of the EAF off-gas emission efficiently.

  10. Method of removing hydrogen sulphide from hot gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Yumura, M.

    1987-12-22

    Hydrogen sulphide can be removed from hot gas mixtures by contacting the hot gas mixture at temperatures in the range of 500-900/sup 0/C with an adsorbent consisting of managanese nodules. The nodules may contain additional calcium cations. In sulphided form, the nodules are catalytically active for hydrogen sulphide decomposition to produce hydrogen. Regeneration of the adsorbent can be accomplished by roasting in an oxidizing atmosphere. The nodules can be used to treat gaseous mixtures containing up to 20% hydrogen sulfide, for example, gases produced during pyrolysis, cracking, coking, and hydrotreating processes. Experiments using the processes described in this patent are also outlined. 6 tabs.

  11. HOT GAS HALOS AROUND DISK GALAXIES: CONFRONTING COSMOLOGICAL SIMULATIONS WITH OBSERVATIONS

    International Nuclear Information System (INIS)

    Rasmussen, Jesper; Sommer-Larsen, Jesper; Pedersen, Kristian; Toft, Sune; Grove, Lisbeth F.; Benson, Andrew; Bower, Richard G.

    2009-01-01

    Models of disk galaxy formation commonly predict the existence of an extended reservoir of accreted hot gas surrounding massive spirals at low redshift. As a test of these models, we use X-ray and Hα data of the two massive, quiescent edge-on spirals NGC 5746 and NGC 5170 to investigate the amount and origin of any hot gas in their halos. Contrary to our earlier claim, the Chandra analysis of NGC 5746, employing more recent calibration data, does not reveal any significant evidence for diffuse X-ray emission outside the optical disk, with a 3σ upper limit to the halo X-ray luminosity of 4 x 10 39 erg s -1 . An identical study of the less massive NGC 5170 also fails to detect any extraplanar X-ray emission. By extracting hot halo properties of disk galaxies formed in cosmological hydrodynamical simulations, we compare these results to expectations for cosmological accretion of hot gas by spirals. For Milky-Way-sized galaxies, these high-resolution simulations predict hot halo X-ray luminosities which are lower by a factor of ∼2 compared to our earlier results reported by Toft et al. We find the new simulation predictions to be consistent with our observational constraints for both NGC 5746 and NGC 5170, while also confirming that the hot gas detected so far around more actively star-forming spirals is in general probably associated with stellar activity in the disk. Observational results on quiescent disk galaxies at the high-mass end are nevertheless providing powerful constraints on theoretical predictions, and hence on the assumed input physics in numerical studies of disk galaxy formation and evolution.

  12. Rheinbraun`s experience in hot gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Renzenbrink, W.; Wischnewski, R. [Rheinbraun AG, Koeln (Germany)

    1998-11-01

    For the introduction of modern types of power stations like IGCC, PCFBC, etc. the application of a functional hot gas filter is of essential importance. A hot gas filter with two tiers for dry and complete dedusting of the entire raw gas flow of 53,000 m{sup 3}(STP)/h was started up in 1993 in the High Temperature Winkler (HTW) coal gasification demonstration plant in Hurth/Berrenrath near Cologne, Germany. The operational data of the filter are a pressure of 10 bar and a temperature of 270{degree}C. The filter was supplied by the `LLB` company and is characterised by the principle of upright arrangement of the ceramic filter elements. During nearly 8,000 h of plant operation up to September 1995 the filter showed stable and safe operation, a separation efficiency of {gt}99.98%, a 21% reduction in filtration surface, reduction in cleaning gas requirement by factor 10, reduction in cleaning gas pressure to 16 bar and a significant reduction in maintenance and operating costs. The resultant clean gas dust content was {lt} 3 mg/m{sup 3}(STP) compared to the design value of 5 mg/m{sup 3}(STP). In a test to the limit of operation one failure occurred when 20 candles broke. In order to yield larger filtering surfaces in very large filter units, e.g. for IGCCs, without using more than one filter the multistage design is the only sensible solution. Prior to industrial-scale application such a system has to be tested. Therefore the two-tier filter was converted into a three-tier type with separate filter modules at the end of 1995. After another 5,400 h of plant operation this three-tier filter shows safe and stable operation with a clean gas dust content of {lt} 2 mg/m{sup 3}(STP). 3 refs., 5 figs., 1 tab.

  13. Potential for preparation of hot gas cleanup sorbents from spent hydroprocessing catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Biagini, M. [Canada Centre for Mineral and Energy Technology, Ottawa, ON (Canada). Energy Research Labs.

    1996-01-01

    Three spent-decoked hydroprocessing catalysts and two corresponding fresh catalysts were tested as hot gas clean-up sorbents and compared with the zinc ferrite using a simulated coal gasification gas mixture. The catalysts deposited only by coke exhibited relatively good cleaning efficiency. The catalyst deposited by coke and metals such as vanadium and nickel was less efficient. The useful life of the spent hydroprocessing catalysts may be extended if utilized as hot gas clean-up sorbents. 12 refs., 3 figs., 4 tabs.

  14. Cosmic X-ray background from hot gas

    International Nuclear Information System (INIS)

    Rogers, R.D.; Field, G.B.

    1991-01-01

    This paper considers constraints on models of the cosmic X-ray background (XRB) in which the XRB is produced by optically thin thermal bremsstrahlung from hot gas. It is shown that models in which the gas is gravitationally confined in a spherical configuration and is heated only once are contradicted by the observed number of gravitationally lensed quasars together with the lower limit on the number of XRB sources required by limits on fluctuations in the XRB and the cosmic microwave background. In addition, it is shown that, for models in which the gas is not gravitationally confined, the expansion time of the gas is much shorter than the radiative cooling time, so that such models cannot explain the XRB. It is concluded that thermal bremsstrahlung models cannot account for the XRB if the emitting gas is heated only once. 31 refs

  15. ASU nitrogen sweep gas in hydrogen separation membrane for production of HRSG duct burner fuel

    Science.gov (United States)

    Panuccio, Gregory J.; Raybold, Troy M.; Jamal, Agil; Drnevich, Raymond Francis

    2013-04-02

    The present invention relates to the use of low pressure N2 from an air separation unit (ASU) for use as a sweep gas in a hydrogen transport membrane (HTM) to increase syngas H2 recovery and make a near-atmospheric pressure (less than or equal to about 25 psia) fuel for supplemental firing in the heat recovery steam generator (HRSG) duct burner.

  16. Cooling Systems Design in Hot Stamping Tools by a Thermal-Fluid-Mechanical Coupled Approach

    Directory of Open Access Journals (Sweden)

    Tao Lin

    2014-06-01

    Full Text Available Hot stamping tools with cooling systems are the key facilities for hot stamping process of Ultrahigh strength steels (UHSS in automotive industry. Hot stamping tools have significant influence on the final microstructure and properties of the hot stamped parts. In serials production, the tools should be rapidly cooled by cooling water. Hence, design of hot stamping tools with cooling systems is important not only for workpieces of good quality but also for the tools with good cooling performance and long life. In this paper, a new multifield simulation method was proposed for the design of hot stamping tools with cooling system. The deformation of the tools was also analyzed by this method. Based on MpCCI (Mesh-based parallel Code Coupling Interface, thermal-fluid simulation and thermal-fluid-mechanical coupled simulation were performed. Subsequently, the geometrical parameters of the cooling system are investigated for the design. The results show that, both the distance between the ducts and the distance between the ducts and the tools loaded contour have significant influence on the quenching effect. And better quenching effect can be achieved with the shorter distance from the tool surface and with smaller distance between ducts. It is also shown that, thermal expansion is the main reason for deformation of the hot forming tools, which causes the distortion of the cooling ducts, and the stress concentration at corner of the ducts.

  17. Energy Requirement and Comfort of Gas- and Electric-powered Hot-water Systems

    International Nuclear Information System (INIS)

    Luedemann, B.; Schmitz, G.

    1999-01-01

    In view of the continuous reduction in the specific heating energy demand of new buildings the power demand for hot-water supply increasingly dominates the heating supply of residential buildings. Furthermore, the German energy-savings-regulation 2000 (ESVO) is intended to evaluate the techniques installed such as domestic heating or hot-water supply within an overall energetic view of the building. Planning advice for domestic heating, ventilation and hot-water systems in gas-heated, low-energy buildings has therefore been developed in a common research project of the Technical University of Hamburg Harburg (TUHH) and four energy supply companies. In this article different gas-or electricity-based hot-water systems in one family houses and multiple family houses are compared with one another with regard to the aspects of comfort and power requirements considering the user's behaviour. (author)

  18. Hot gas filtration: Investigations to remove gaseous pollutant components out of flue gas during hot gas filtration. Final report; HGR: Untersuchung zur Minimierung von gasfoermigen Schadstoffen aus Rauchgasen bei der Heissgasfiltration. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Christ, A; Gross, R; Renz, U

    1998-07-01

    Power plants with gas and steam turbines in pressurized fluidized bed or pressurized gasification processes enable power generation of coal with high efficiency and little emissions. To run these plants the cleaning of the flue gas is necessary before entering the turbines under the conditions of high temperature and pressure. Ceramic filter elements are the most probable method for hot gas cleaning. A simultaneous reduction of gaseous pollutant components under these conditions could help to make the whole process more efficient. The aim of the project is to integrate the catalytic reduction of carbon monoxide, hydrocarbons and nitric oxides into the hot gas filtration with ceramic filter elements as a one step mecanism. The project is focused on: - the catalytic behaviour of ferruginous ashes of brown coal, - the effectiveness of calcinated aluminates as a catalyst to remove uncombusted hydrocarbons in a hot gas filtration unit, - numerical simulation of the combined removal of particles and gaseous pollutant components out of the flue gas. (orig.) [Deutsch] Gas- und Dampfturbinen-Kraftwerke mit Druckwirbelschicht- oder mit Druckvergasungsverfahren ermoeglichen die Verstromung von Kohle mit hohem Wirkungsgrad und niedrigen Emissionen. Eine Voraussetzung fuer den Betrieb dieser Anlagen ist die Entstaubung der Rauchgase bei hohen Temperaturen und Druecken. Abreinigungsfilter mit keramischen Elementen werden dazu eingesetzt. Eine Reduzierung gasfoermiger Schadstoffe unter den gleichen Bedingungen koennte die Rauchgaswaesche ersetzen. Ziel des Gesamtvorhabens ist es, die Integration von Heissgasfiltration und katalytischem Abbau der Schadstoffe Kohlenmonoxid, Kohlenwasserstoffe und Stickoxide in einem Verfahrensschritt zu untersuchen. Die Arbeitsschwerpunkte dieses Teilvorhabens betreffen - die katalytische Wirkung eisenhaltiger Braunkohlenaschen, - die Wirksamkeit des Calciumaluminats als Katalysator des Abbaus unverbrannter Kohlenwasserstoffe im Heissgasfilter

  19. Hot Gas Cleanup Test Facility for gasification and pressurized combustion. Quarterly report, October--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-01

    The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the original Transport Reactor gas source and Hot Gas Cleanup Units: carbonizer/pressurized circulating fluidized bed gas source; hot gas cleanup units to mate to all gas streams; combustion gas turbine; and fuel cell and associated gas treatment. The major emphasis during this reporting period was continuing the detailed design of the facility and integrating the particulate control devices (PCDs) into structural and process designs. Substantial progress in underground construction activities was achieved during the quarter. Delivery and construction of coal handling and process structural steel began during the quarter. Delivery and construction of coal handling and process structural steel began during the quarter. MWK equipment at the grade level and the first tier are being set in the structure.

  20. Efficiency enhancement in IGCC power plants with air-blown gasification and hot gas clean-up

    International Nuclear Information System (INIS)

    Giuffrida, Antonio; Romano, Matteo C.; Lozza, Giovanni

    2013-01-01

    Air-blown IGCC systems with hot fuel gas clean-up are investigated. In detail, the gas clean-up station consists of two reactors: in the first, the raw syngas exiting the gasifier and passed through high-temperature syngas coolers is desulfurized by means of a zinc oxide-based sorbent, whereas in the second the sulfided sorbent is duly regenerated. The hot fuel gas clean-up station releases H 2 S-free syngas, which is ready to fuel the combustion turbine after hot gas filtration, and a SO 2 -laden stream, which is successively treated in a wet scrubber. A thermodynamic analysis of two air-blown IGCC systems, the first with cold fuel gas clean-up and the second with hot fuel gas clean-up, both with a state-of-the-art combustion turbine as topping cycle, shows that it is possible to obtain a really attractive net efficiency (more than 51%) for the second system, with significant improvements in comparison with the first system. Nevertheless, higher efficiency is accomplished with a small reduction in the power output and no sensible efficiency improvements seem to be appreciated when the desulfurization temperature increases. Other IGCC systems, with an advanced 1500 °C-class combustion turbine as the result of technology improvements, are investigated as well, with efficiency as high as 53%. - Highlights: ► Hot fuel gas clean-up is a highly favorable technology for IGCC concepts. ► Significant IGCC efficiency improvements are possible with hot fuel gas clean-up. ► Size reductions of several IGCC components are possible. ► Higher desulfurization temperatures do not sensibly affect IGCC efficiency. ► IGCC efficiency as high as 53% is possible with a 1500°C-class combustion turbine

  1. High-BTU gas production from tar-bearing hot coke oven gas over iron catalyst

    Energy Technology Data Exchange (ETDEWEB)

    L.Y. Li; K. Morishita; T. Takarada [Gunma University, Gunma (Japan). Department of Biological and Chemical Engineering

    2005-07-01

    To utilize the tar-bearing hot coke oven gas (the by-product of coke making process) more effectively, a process was developed by converting the hot coke oven gas into a methane rich high-BTU gas over iron-bearing catalysts. The catalytic behaviour of Indonesian limonite ore was mainly discussed. For a reference, a conventional nickel catalyst (Ni/Al{sub 2}O{sub 3}) was employed. Laboratory scale tests were carried out in a two-stage fixed-bed reactor at ambient pressure. A bituminous coal sample was heated at first stage, the volatiles was carried by feed gas and decomposed at second stage. The limonite promoted hydropyrolysis of coal volatiles similar to Ni/Al{sub 2}O{sub 3} catalyst. High yields of total product gas and methane were obtained at 50 vol.% hydrogen atmosphere with a feed gas of 60 ml min{sup -1} hydrogen and 60 ml min{sup -1} nitrogen. After experiments, hydrocarbons heavier than ethane were not observed. Also that, carbon balance was more than 99.8% in coal char, product gases and carbon deposits. It was considered that coal volatiles converted into light gases and carbon almost completely in catalyst bed. Yields of product gas and methane depended upon catalytic temperature. At 923 K, the maximum yield of product gas was achieved at 74.3% for limonite catalyst on carbon balance with methane 83.2 vol.% of the carbonaceous gas products. Comparing with limonite, Fe/Al{sub 2}O{sub 3} and BOF dust samples showed low activities on coal volatiles catalytic decomposition. 21 refs., 5 figs., 3 tabs.

  2. A study on CT features of intrahepatic bile duct abscess

    International Nuclear Information System (INIS)

    Min Pengqiu; Li Peng; He Zhiyan; Chen Weixia; Liu Yan

    2001-01-01

    Objective: To evaluate CT features of intrahepatic bile duct abscess (IBDA) and its pathologic basis. Methods: The CT imaging data of 31 consecutive cases of intrahepatic bile duct abscess proved by surgery or clinical treatments from October 1989 to February 1999 were retrospectively studied. The causes included acute obstructive suppurative cholangitis and retrograde infection due to different etiologies. For all the cases, the CT manifestations of liver abscess, bile duct abnormalities, and their relationship were observed respectively. Results: Manifestations of liver abscess were revealed in all cases (31/31, 100%). The CT manifestations of bile duct abnormalities included signs of etiologies caused bile duct obstruction and other signs including cholangiectasis (29/31, 93.5%), the dilated bile ducts communicated with (5/31, 16.1%) or abut on (8/31, 25.8%) the abscesses, and gas collection in bile ducts (10/31, 32.2%). The signs showing the relationship between liver abscess and bile duct abnormalities were that the abscesses complied with the obstructive site and the dilated bile ducts (15/31, 48.4%), and the liver abscesses located in different (7/31, 22.6%) or same (4/31, 12.9%) liver lobes or segments with gas collection in the dilated bile ducts. Conclusion: The CT manifestations of IBDA included signs of liver abscess, abnormalities of bile ducts, and signs showing their relationship. CT scanning was helpful in making comprehensive and accurate diagnosis of IBDA

  3. Modelling of hot surface ignition within gas turbines subject to flammable gas in the intake

    DEFF Research Database (Denmark)

    Pedersen, Lea Duedahl; Nielsen, Kenny Krogh; Yin, Chungen

    2017-01-01

    Controlling risks associated with fires and explosions from leaks of flammable fluids at oil and gas facilities is paramount to ensuring safe operations. The gas turbine is a significant potential source of ignition; however, the residual risk is still not adequately understood. A model has been...... but decreases with increase in initial mixture temperature and pressure. The model shows a great potential in reliable prediction of the risk of hot surface ignition within gas turbines in the oil and gas industry. In the future, a dedicated experimental study will be performed not only to improve...

  4. Hot gas cleanup test facility for gasification and pressurized combustion. Quarterly technical progress report, July 1--September 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the existing Transport Reactor gas source and Hot Gas Cleanup Units: Carbonizer/Pressurized Circulating Fluidized Bed Gas Source; hot Gas Cleanup Units to mate to all gas streams; and Combustion Gas Turbine. Fuel Cell and associated gas treatment. This expansion to the Hot Gas Cleanup Test Facility is herein referred to as the Power Systems Development Facility (PSDF).

  5. Duct burners in heat recovery system for cogeneration and captive power plants

    International Nuclear Information System (INIS)

    Majumdar, J.

    1992-01-01

    Our oil explorations both onshore and offshore have thrown open bright prospects of cogeneration by using natural gas in gas turbine power plants with heat recovery units. Both for co-gen and combined cycle systems, supplementary firing of GT exhaust gas is normally required. Hence, duct burners have significant role for effective contribution towards of efficacy of heat recovery system for gas turbine exhaust gas. This article details on various aspects of duct burners in heat recovery systems. (author)

  6. Gas turbine structural mounting arrangement between combustion gas duct annular chamber and turbine vane carrier

    Science.gov (United States)

    Wiebe, David J.; Charron, Richard C.; Morrison, Jay A.

    2016-10-18

    A gas turbine engine ducting arrangement (10), including: an annular chamber (14) configured to receive a plurality of discrete flows of combustion gases originating in respective can combustors and to deliver the discrete flows to a turbine inlet annulus, wherein the annular chamber includes an inner diameter (52) and an outer diameter (60); an outer diameter mounting arrangement (34) configured to permit relative radial movement and to prevent relative axial and circumferential movement between the outer diameter and a turbine vane carrier (20); and an inner diameter mounting arrangement (36) including a bracket (64) secured to the turbine vane carrier, wherein the bracket is configured to permit the inner diameter to move radially with the outer diameter and prevent axial deflection of the inner diameter with respect to the outer diameter.

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

    Science.gov (United States)

    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).

  8. Experimental and theoretical investigations on the dynamic response of EBR-II ducts under pressure pulse loading

    International Nuclear Information System (INIS)

    Chopra, P.S.; Srinivas, S.

    1975-01-01

    In order to assess the potential damage to hexagonal subassembly ducts (cans) that may result from rapid gas release from a failed element the EBR-II project has conducted experiments and analyses. Additional experimental and analytical investigations are now being conducted to assure fail-safety of the ducts. Fail-safety is defined as the ability of a duct to withstand pressure pulses from failed elements during all reactor conditions without damage to adjacent ducts or any other problems in fuel handling. The results of 93 EBR-II duct tests conducted primarily by Koenig have been reported previously. The results of empirical correlations of some of these tests to determine the influence of several variables on the pressure pulse experienced by a duct and on the duct deformation are presented. The variables include the type of gas contained in the simulated element (tube), the element and duct materials, the presence or absence of flow restrictors in the element, and the way gas was released. 8 references. (auth)

  9. Review of hot corrosion of thermal barrier coatings of gas turbine

    Directory of Open Access Journals (Sweden)

    LIU Yongbao

    2017-03-01

    Full Text Available The review was done in order to make clear the problem of the hot corrosion of the Thermal Barrier Coatings(TBCsduring gas turbine serving. This paper summarizes the factors resulting from the hot corrosion of TBCs during turbine service and classifies methods for enhancing the corrosive resistance of TBCs. A prospective methodology for improving corrosion resistance is also formulated. The main types of corrosion coating include phase reaction, oxidizing of the bond coating, salt-fog corrosion, CMAS corrosion and fuel impurity corrosion. So far, methods for improving the corrosion resistance of TBCs include developing new coating materials, anticorrosive treatment on the surface of TBCs, modifying the stacking configuration and improving the cleansing functions of the gas turbines. In the future, developing new materials with excellent performance will still be the main direction for boosting the improvement of the hot corrosion resistance of TBCs. Simultaneously, improving the tacking configuration and nanotechnology of TBC coatings are potential approaches for improving corrosion resistance. With the development of a Ceramic Matrix Composite (CMC, the focus of the hot corrosion of TBCs may turn to that of Environmental Barrier Coatings (EBCs.

  10. Consistent approach to air-cleaning system duct design

    International Nuclear Information System (INIS)

    Miller, W.H.; Ornberg, S.C.; Rooney, K.L.

    1981-01-01

    Nuclear power plant air-cleaning system effectiveness is dependent on the capability of a duct system to safely convey contaminated gas to a filtration unit and subsequently to a point of discharge. This paper presents a logical and consistent design approach for selecting sheet metal ductwork construction to meet applicable criteria. The differences in design engineers' duct construction specifications are acknowledged. Typical duct construction details and suggestions for their effective use are presented. Improvements in duct design sections of ANSI/ASME N509-80 are highlighted. A detailed leakage analysis of a control room HVAC system is undertaken to illustrate the effects of conceptual design variations on duct construction requirements. Shortcomings of previously published analyses and interpretations of a current standard are included

  11. Baffles Promote Wider, Thinner Silicon Ribbons

    Science.gov (United States)

    Seidensticker, Raymond G.; Mchugh, James P.; Hundal, Rolv; Sprecace, Richard P.

    1989-01-01

    Set of baffles just below exit duct of silicon-ribbon-growing furnace reduces thermal stresses in ribbons so wider ribbons grown. Productivity of furnace increased. Diverts plume of hot gas from ribbon and allows cooler gas from top of furnace to flow around. Also shields ribbon from thermal radiation from hot growth assembly. Ribbon cooled to lower temperature before reaching cooler exit duct, avoiding abrupt drop in temperature as entering duct.

  12. Simultaneous desulfurization and denitrification of flue gas by ·OH radicals produced from O2+ and water vapor in a duct.

    Science.gov (United States)

    Bai, Mindi; Zhang, Zhitao; Bai, Mindong

    2012-09-18

    In the present study, simultaneous flue gas desulfurization and denitrification are achieved with ·OH radicals generated from O(2)(+) reacting with water vapor in a duct. The O(2)(+) ions are generated by a strong ionization dielectric barrier discharge and then injected into the duct. Compared with conventional gas discharge treatment, the present method does not need a plasma reaction reactor, additional catalysts, reductants, or oxidants. The main recovered products are the liquids H(2)SO(4) and HNO(3), which can be used in many processes. Removal rates of 97% for NO and 82% for SO(2) are obtained under the following optimal experimental conditions: molar ratio of reactive oxygen species (O(2)(+), O(3)) to SO(2) and NO, 5; inlet flue gas temperature, 65 °C; reaction time, 0.94 s; and H(2)O volume fraction, 8%. Production of O(2)(+) and the plasma reaction mechanisms are discussed, and the recovered acid is characterized. The experimental results show that the present method performs better for denitrification than for desulfurization. Compared with conventional air discharge flue gas treatments, the present method has lower initial investment and operating costs, and the equipment is more compact.

  13. Thermoelectric Power Generation System for Future Hybrid Vehicles Using Hot Exhaust Gas

    Science.gov (United States)

    Kim, Sun-Kook; Won, Byeong-Cheol; Rhi, Seok-Ho; Kim, Shi-Ho; Yoo, Jeong-Ho; Jang, Ju-Chan

    2011-05-01

    The present experimental and computational study investigates a new exhaust gas waste heat recovery system for hybrid vehicles, using a thermoelectric module (TEM) and heat pipes to produce electric power. It proposes a new thermoelectric generation (TEG) system, working with heat pipes to produce electricity from a limited hot surface area. The current TEG system is directly connected to the exhaust pipe, and the amount of electricity generated by the TEMs is directly proportional to their heated area. Current exhaust pipes fail to offer a sufficiently large hot surface area for the high-efficiency waste heat recovery required. To overcome this, a new TEG system has been designed to have an enlarged hot surface area by the addition of ten heat pipes, which act as highly efficient heat transfer devices and can transmit the heat to many TEMs. As designed, this new waste heat recovery system produces a maximum 350 W when the hot exhaust gas heats the evaporator surface of the heat pipe to 170°C; this promises great possibilities for application of this technology in future energy-efficient hybrid vehicles.

  14. Studying the sampling representativeness in the NPP ventilation ducts

    International Nuclear Information System (INIS)

    Sosnovskij, R.I.; Fedchenko, T.K.; Minin, S.A.

    2000-01-01

    Measurements of the gas and aerosol voluminous activity in the NPP ventilation ducts are an important source of information on the radiation contaminants ingress into the environmental medium. These measurements include sampling, samples transport and proper measurements. The work is devoted to calculation of metrological characteristics of the sampling systems for the NPP gas-aerosol releases by different parameters of these systems and ventilation ducts. The results obtained are intended for application by designing such systems and their metrological certification [ru

  15. The origin of the hot metal-poor gas in NGC 1291 - Testing the hypothesis of gas dynamics as the cause of the gas heating

    NARCIS (Netherlands)

    Perez, [No Value; Freeman, K

    In this paper we test the idea that the low-metallicity hot gas in the centre of NGC 1291 is heated via a dynamical process. In this scenario, the gas from the outer gas-rich ring loses energy through bar-driven shocks and falls to the centre. Heating of the gas to X-ray temperatures comes from the

  16. HOT CELL SYSTEM FOR DETERMINING FISSION GAS RETENTION IN METALLIC FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Sell, D. A.; Baily, C. E.; Malewitz, T. J.; Medvedev, P. G.; Porter, D. L.; Hilton, B. A.

    2016-09-01

    A system has been developed to perform measurements on irradiated, sodium bonded-metallic fuel elements to determine the amount of fission gas retained in the fuel material after release of the gas to the element plenum. During irradiation of metallic fuel elements, most of the fission gas developed is released from the fuel and captured in the gas plenums of the fuel elements. A significant amount of fission gas, however, remains captured in closed porosities which develop in the fuel during irradiation. Additionally, some gas is trapped in open porosity but sealed off from the plenum by frozen bond sodium after the element has cooled in the hot cell. The Retained fission Gas (RFG) system has been designed, tested and implemented to capture and measure the quantity of retained fission gas in characterized cut pieces of sodium bonded metallic fuel. Fuel pieces are loaded into the apparatus along with a prescribed amount of iron powder, which is used to create a relatively low melting, eutectic composition as the iron diffuses into the fuel. The apparatus is sealed, evacuated, and then heated to temperatures in excess of the eutectic melting point. Retained fission gas release is monitored by pressure transducers during the heating phase, thus monitoring for release of fission gas as first the bond sodium melts and then the fuel. A separate hot cell system is used to sample the gas in the apparatus and also characterize the volume of the apparatus thus permitting the calculation of the total fission gas release from the fuel element samples along with analysis of the gas composition.

  17. Various Transport Phenomena and Modeling in a Methane Reformer Duct for PEMFCs

    International Nuclear Information System (INIS)

    Jinliang Yuan; Fuan Ren; Jinliang Yuan; Bengt Sunden

    2006-01-01

    There are various physical processes (such as mass, heat and momentum transport) integrated with catalytic chemical reactions in a methane steam reforming duct. It is often found that endothermic and exothermic reactions in the ducts are strongly coupled by heat transfer from adjacent catalytic combustion ducts. In this paper, a three-dimensional calculation method is developed to simulate and analyze steam reforming of methane, and the effects on various transport processes in a steam reforming duct. The reformer conditions such as mass balances associated with the reforming reactions and gas permeation to/from the porous catalyst layer are applied in the analysis. The predicted results are presented and discussed for a composite duct consisting of a porous catalyst reaction area, the gas flow duct and solid layers. Parametric studies are conducted and the results show that the variables, such as fuel reformer temperatures and catalyst loadings, have significant effects on the transport processes and reformer performance. (authors)

  18. Solar coal gasification reactor with pyrolysis gas recycle

    Science.gov (United States)

    Aiman, William R.; Gregg, David W.

    1983-01-01

    Coal (or other carbonaceous matter, such as biomass) is converted into a duct gas that is substantially free from hydrocarbons. The coal is fed into a solar reactor (10), and solar energy (20) is directed into the reactor onto coal char, creating a gasification front (16) and a pyrolysis front (12). A gasification zone (32) is produced well above the coal level within the reactor. A pyrolysis zone (34) is produced immediately above the coal level. Steam (18), injected into the reactor adjacent to the gasification zone (32), reacts with char to generate product gases. Solar energy supplies the energy for the endothermic steam-char reaction. The hot product gases (38) flow from the gasification zone (32) to the pyrolysis zone (34) to generate hot char. Gases (38) are withdrawn from the pyrolysis zone (34) and reinjected into the region of the reactor adjacent the gasification zone (32). This eliminates hydrocarbons in the gas by steam reformation on the hot char. The product gas (14) is withdrawn from a region of the reactor between the gasification zone (32) and the pyrolysis zone (34). The product gas will be free of tar and other hydrocarbons, and thus be suitable for use in many processes.

  19. Ceramic hot-gas filter

    Science.gov (United States)

    Connolly, E.S.; Forsythe, G.D.; Domanski, D.M.; Chambers, J.A.; Rajendran, G.P.

    1999-05-11

    A ceramic hot-gas candle filter is described having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during back pulse cleaning and is resistant to chemical degradation at high temperatures.

  20. Ceramic hot-gas filter

    Science.gov (United States)

    Connolly, Elizabeth Sokolinski; Forsythe, George Daniel; Domanski, Daniel Matthew; Chambers, Jeffrey Allen; Rajendran, Govindasamy Paramasivam

    1999-01-01

    A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

  1. Two phase flow combustion modelling of a ducted rocket

    NARCIS (Netherlands)

    Stowe, R.A.; Dubois, C.; Harris, P.G.; Mayer, A.E.H.J.; Champlain, A. de; Ringuette, S.

    2001-01-01

    Under a co-operative program, the Defence Research Establishment Valcartier and Université Laval in Canada and the TNO Prins Maurits Laboratory in the Netherlands have studied the use of a ducted rocket for missile propulsion. Hot-flow direct-connect combustion experiments using both simulated and

  2. High temperature gasification and gas cleaning – phase II of the HotVegas project

    OpenAIRE

    Meysel, P.; Halama, S.; Botteghi, F.; Steibel, M.; Nakonz, M.; Rück, R.; Kurowski, P.; Buttler, A.; Spliethoff, H.

    2016-01-01

    The primary objective of the research project HotVeGas is to lay the necessary foundations for the long-term development of future, highly efficient high-temperature gasification processes. This includes integrated hot gas cleaning and optional CO2 capture and storage for next generation IGCC power plants and processes for the development of synthetic fuels. The joint research project is funded by the German Federal Ministry of Economics and Technology and five industry partners. It is coordi...

  3. Detection of leaks for radioactive tracer in marine duct for transport of liquefied petroleum gas

    International Nuclear Information System (INIS)

    Robles P, E. F.; Benitez S, J. A.; Torre O, J. de la; Cruz S, E. de la; Molina, G.; Hernandez C, J. E.; Flores M, J. . e mail: efrp@nuclear.inin.mx

    2008-01-01

    In this work the aplication in the oil industry of the technique of radioactive tracer appears for the detection of internal leaks in a submarine duct that gives service as it lines of receipt of liquefied petroleum gas (Gas LP) located in the Mexican coast of the Pacific Ocean. This system of marine pipe is a consistent arrangement of a duct interior of 0.254 m (10 inches) of nominal diameter (N.D.) of steel to the carbon for cryogenic service ASTM A 333, Grade 6, schedule 30, isolated thermally with foam of polyurethane and shielding in a steel tube to the carbon ASTM A 53 Grade A, of 0.508 m (20 inches) N. D., schedule 20, which is recovered by a ballast encircling of concrete of 0.0508 m (2 inches) of thickness, reinforced with mesh metallic, and that 1315 m runs on the marine stratum to a maximum depth of 12.5 m. For the detection of leaks by radiotracer it was used as tracer the radioactive isotope La-140 produced in the TRIGA Mark III Experimental Reactor of the National Institute of Nuclear Research, starting from stable lanthanum nitrate (La(NO 3 ) 3 6H 2 O), with an activity of 100 mCi, the one which after having been made logistics tasks, given very particular sea maneuvers and due to the conditions of the work place, in the interior tube was injected in two subsequent stages to cover both duct senses; from earth and from the marine end respectively, there being used fresh water like transport way and submergible sodium iodide detectors (NaI) for the rake of the La-140. At the end of the journeys of pursuit of the radiotracer, it was determine the presence of three leaks points located in the break area of the marine surf to 360 m, 450 m and 495 m of distance of a reference point located in the beach section named Trap of Devils. (Author)

  4. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corporation, Columbus, Ohio

    Science.gov (United States)

    1980-01-01

    The solar energy system installed in the building has 2,978 sq ft of single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/hour water tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

  5. Modelling the dynamics of the cogeneration power plant gas-air duct

    Directory of Open Access Journals (Sweden)

    Аnatoliy N. Bundyuk

    2014-12-01

    Full Text Available Introducing into wide practice the cogeneration power plants (or CHP is one of promising directions of the Ukrainian small-scale power engineering development. Thermal and electric energy generation using the same fuel kind can increase the overall plant efficiency. That makes it appropriate to use CHPs at compact residential areas, isolated industrial enterprises constituting one complex with staff housing area, at sports complexes, etc. The gas-air duct of the cogeneration power plant has been considered as an object of the diesel-generator shaft velocity control. The developed GAD mathematical model, served to analyze the CHP dynamic characteristics as acceleration curves obtained under different external disturbances in the MathWorks MATLAB environment. According to the electric power generation technology requirements a convenient transition process type has been selected, with subsequent identification of the diesel-generator shaft rotation speed control law.

  6. The ATLAS(3D) project : XIX. The hot gas content of early-type galaxies: fast versus slow rotators

    NARCIS (Netherlands)

    Sarzi, Marc; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bournaud, Frederic; Bureau, Martin; Cappellari, Michele; Crocker, Alison; Davies, Roger L.; Davis, Timothy A.; de Zeeuw, P. T.; Duc, Pierre-Alain; Emsellem, Eric; Khochfar, Sadegh; Krajnovic, Davor; Kuntschner, Harald; Lablanche, Pierre-Yves; McDermid, Richard M.; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Scott, Nicholas; Serra, Paolo; Young, Lisa M.; Weijmans, Anne-Marie

    2013-01-01

    For early-type galaxies, the ability to sustain a corona of hot, X-ray-emitting gas could have played a key role in quenching their star formation history. A halo of hot gas may act as an effective shield against the acquisition of cold gas and can quickly absorb stellar mass loss material. Yet,

  7. The ATLAS3D project - XIX. The hot gas content of early-type galaxies: fast versus slow rotators

    NARCIS (Netherlands)

    Sarzi, Marc; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bournaud, Frédéric; Bureau, Martin; Cappellari, Michele; Crocker, Alison; Davies, Roger L.; Davis, Timothy A.; de Zeeuw, P. T.; Duc, Pierre-Alain; Emsellem, Eric; Khochfar, Sadegh; Krajnović, Davor; Kuntschner, Harald; Lablanche, Pierre-Yves; McDermid, Richard M.; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Scott, Nicholas; Serra, Paolo; Young, Lisa M.; Weijmans, Anne-Marie

    For early-type galaxies, the ability to sustain a corona of hot, X-ray-emitting gas could have played a key role in quenching their star formation history. A halo of hot gas may act as an effective shield against the acquisition of cold gas and can quickly absorb stellar mass loss material. Yet,

  8. Specialists' meeting on heat exchanging components of gas-cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1984-07-01

    The objective of the Meeting sponsored by IAEA was to provide a forum for the exchange and discussion of technical information related to heat exchanging and heat conducting components for gas-cooled reactors. The technical part of the meeting covered eight subjects: Heat exchanging components for process heat applications, design and requirements, and research and development programs; Status of the design and construction of intermediate He/He exchangers; Design, construction and performance of steam generators; Metallic materials and design codes; Design and construction of valves and hot gas ducts; Description of component test facilities and test results; Manufacturing of heat exchanging components.

  9. Specialists' meeting on heat exchanging components of gas-cooled reactors

    International Nuclear Information System (INIS)

    1984-01-01

    The objective of the Meeting sponsored by IAEA was to provide a forum for the exchange and discussion of technical information related to heat exchanging and heat conducting components for gas-cooled reactors. The technical part of the meeting covered eight subjects: Heat exchanging components for process heat applications, design and requirements, and research and development programs; Status of the design and construction of intermediate He/He exchangers; Design, construction and performance of steam generators; Metallic materials and design codes; Design and construction of valves and hot gas ducts; Description of component test facilities and test results; Manufacturing of heat exchanging components

  10. Removal of H/sub 2/S from hot gas in the presence of Cu-containing sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Kyotani, T.; Kawashima, H.; Tomita, A.; Palmer, A.; Furimsky, E.

    1989-01-01

    Three solids containing Cu oxides were tested as sorbents for H/sub 2/S removal from hot gas at 600 degrees C. The formation of a surface layer of sulphides on pellet exterior affected Cu utilization for the sorbent prepared from Cu oxides alone. This improved for the sorbent prepared by impregnation of zeolite with Cu oxides, although complete utilization of Cu was not achieved. The combination of Cu oxides with SiO/sub 2/ gave the most efficient sorbent. Oxidation of H/sub 2/S to SO/sub 2/ on admission of hot gas to the fixed bed was a common observation for all sorbents. The addition of steam to hot gas suppressed the SO/sub 2/ formation. 9 refs., 6 figs., 4 tabs.

  11. HOT AND COLD GALACTIC GAS IN THE NGC 2563 GALAXY GROUP

    International Nuclear Information System (INIS)

    Rasmussen, Jesper; Bai, Xue-Ning; Mulchaey, John S.; Van Gorkom, J. H.; Lee, Duane; Jeltema, Tesla E.; Zabludoff, Ann I.; Wilcots, Eric; Martini, Paul; Roberts, Timothy P.

    2012-01-01

    The role of environmentally induced gas stripping in driving galaxy evolution in groups remains poorly understood. Here we present extensive Chandra and Very Large Array mosaic observations of the hot and cold interstellar medium within the members of the nearby, X-ray bright NGC 2563 group, a prime target for studies of the role of gas stripping and interactions in relatively small host halos. Our observations cover nearly all group members within a projected radius of 1.15 Mpc (∼1.4 R vir ) of the group center, down to a limiting X-ray luminosity and H I mass of 3 × 10 39 erg s –1 and 2 × 10 8 M ☉ , respectively. The X-ray data are consistent with efficient ram pressure stripping of the hot gas halos of early-type galaxies near the group core, but no X-ray tails are seen and the limited statistics preclude strong conclusions. The H I results suggest moderate H I mass loss from the group members when compared to similar field galaxies. Six of the 20 H I-detected group members show H I evidence of ongoing interactions with other galaxies or with the intragroup medium. Suggestive evidence is further seen for galaxies with close neighbors in position-velocity space to show relatively low H I content, consistent with tidal removal of H I. The results thus indicate removal of both hot and cold gas from the group members via a combination of ram pressure stripping and tidal interactions. We also find that 16 of the 20 H I detections occur on one side of the group, reflecting an unusual morphological segregation whose origin remains unclear.

  12. Heat Transfer Computations of Internal Duct Flows With Combined Hydraulic and Thermal Developing Length

    Science.gov (United States)

    Wang, C. R.; Towne, C. E.; Hippensteele, S. A.; Poinsatte, P. E.

    1997-01-01

    This study investigated the Navier-Stokes computations of the surface heat transfer coefficients of a transition duct flow. A transition duct from an axisymmetric cross section to a non-axisymmetric cross section, is usually used to connect the turbine exit to the nozzle. As the gas turbine inlet temperature increases, the transition duct is subjected to the high temperature at the gas turbine exit. The transition duct flow has combined development of hydraulic and thermal entry length. The design of the transition duct required accurate surface heat transfer coefficients. The Navier-Stokes computational method could be used to predict the surface heat transfer coefficients of a transition duct flow. The Proteus three-dimensional Navier-Stokes numerical computational code was used in this study. The code was first studied for the computations of the turbulent developing flow properties within a circular duct and a square duct. The code was then used to compute the turbulent flow properties of a transition duct flow. The computational results of the surface pressure, the skin friction factor, and the surface heat transfer coefficient were described and compared with their values obtained from theoretical analyses or experiments. The comparison showed that the Navier-Stokes computation could predict approximately the surface heat transfer coefficients of a transition duct flow.

  13. Dynamics of a hot (T∼107 K) gas cloud with volume energy losses

    International Nuclear Information System (INIS)

    Suchkov, A.A.; Berman, V.G.; Mishurov, Yu.N.

    1987-01-01

    The dynamics of a hot (T=10 6 -5x10 7 K) gas cloud with volume energy losses is investigated by numerical integration of gas dynamics equations. The dynamics is governed by a spherically symmetric gravitational field of the cloud and additional ''hidden'' mass. The cloud mass is taken in the range M 0 =10 10 -10 12 M sun , its radius R 0 =50-200 kpc, the ''hidden'' mass M ν =10 11 -3x10 13 M sun . The results show that in such sytems a structure can develop in the form of a dense compact nucleus with a radius R s 0 , and an extended rarefied hot envelope with a radius R X ∼ R 0 . Among the models involved are those where the gas cloud is either entirely blown up or entirely collapses; in some models, after the phase of initial expansion, part of the gas mass returns back into the system to form a nucleus and an envelope, and the other part leaves the system. The results are discussed in connection with the formation and early evolution of galaxies, the history of star formation and chemical evolution of galaxies, the origin of hot gas in galaxies and clusters of galaxies. It is suggested that in the real history of galaxies, formation of the nucleus and envelope corresponds to formation of galactic stellar component and X-ray halo

  14. Gas geochemistry of the hot spring in the Litang fault zone, Southeast Tibetan Plateau

    International Nuclear Information System (INIS)

    Zhou, Xiaocheng; Liu, Lei; Chen, Zhi; Cui, Yueju; Du, Jianguo

    2017-01-01

    The southeast Tibetan Plateau is a region with high level seismic activity and strong hydrothermal activity. Several large (7.5 > M > 7) historical earthquakes have occurred in the Litang fault zone (LFZ), eastern Tibetan Plateau since 1700. Litang Ms 5.1 earthquake occurred On Sept 23, 2016, indicating the reactivation of the LFZ. This study was undertaken to elucidate spatial-temporal variations of the hot spring gas geochemistry along the LFZ from Jun 2010 to April 2016. The chemical components, He, Ne and C isotropic ratios of bubbling gas samples taken from 18 hot springs along LFZ were investigated. Helium isotope ratios ( 3 He/ 4 He) measured in hot springs varied from 0.06 to 0.93 Ra (Ra = air 3 He/ 4 He = 1.39 × 10 −6 ), with mantle-derivd He up to 11.1% in the LFZ (assuming R/Ra = 8 for mantle) indicated the fault was a crustal-scale feature that acts as a conduit for deep fluid from the mantle. CO 2 concentrations of the majority of hot spring gas samples were ≥80 vol%, CO 2 / 3 He ratios varied from 1.4 to 929.5 × 10 10 , and δ 13 C CO2 values varied from −19.2‰ to −2.3‰ (vs. PDB). The proportions of mantle-derived CO 2 varied from 0 to 1.8%. Crustal marine limestone was the major contributor (>75%) to the carbon inventory of the majority of hot spring gas samples. Before Litang Ms 5.1 earthquake, the 3 He/ 4 He ratios obviously increased in the Heni spring from May 2013 to Apr 2016. The geographical distribution of the mantle-derivd He decreased from east to west along 30°N in the southeast Tibetan Plateau relative to a corresponding increase in the radiogenic component. The gas geochemical data suggested that the upwelling mantle fluids into the crust play an important role in seismic activity in the strike-slip faults along 30°N in the southeast Tibetan Plateau. - Highlights: • Gas geochemistry of hot springs along Litang fault, Southeast Tibetan Plateau were surveyed. • Mantle-derived He decreased from east to

  15. Core-in-shell sorbent for hot coal gas desulfurization

    Science.gov (United States)

    Wheelock, Thomas D.; Akiti, Jr., Tetteh T.

    2004-02-10

    A core-in-shell sorbent is described herein. The core is reactive to the compounds of interest, and is preferably calcium-based, such as limestone for hot gas desulfurization. The shell is a porous protective layer, preferably inert, which allows the reactive core to remove the desired compounds while maintaining the desired physical characteristics to withstand the conditions of use.

  16. Testing and analyses of a high temperature duct for gas-cooled reactors

    International Nuclear Information System (INIS)

    Black, W.E.; Roberge, A.; Felten, P.; Bastien, R.

    1979-01-01

    A 0.6 scale model of a steam cycle gas-cooled reactor high temperature duct was tested in a closed loop helium facility. The object of the test series was to determine: 1) the thermal effects of gas permeation within the thermal barrier, 2) the plastic deformation of the metallic components, and 3) the thermal performance of the fibrous insulation. A series of tests was performed with thermal cyclings from 100 0 C to 760 0 C at 50 atmospheres until the system thermal performance had stabilized hence enabling predictions for the reactor life. Additional tests were made to assess permeation by deliberately simulating sealing weld failures thereby allowing gas flow by-pass within the primary thermal barrier. After 100 cycles the entire primary structure was found to have performed without structural failure. Due to high pressures exerted by the insulation on the cover plates and a design oversight, the thin seal sheets were unable to expand in an anticipated manner. Local buckling resulted. Pre and post test metallurgical analyses were conducted on the Hastelloy-X structures and reference specimens. The results gave evidence of aging in the form of noticeable changes in room temperature tensile and reduction in area parameters. The Hastelloy-X welds exhibited greater changes in properties due to thermal aging. The antifriction coating (Cr 3 C 2 ) performed well without spallation or excessive wear. (orig.)

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

    International Nuclear Information System (INIS)

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

    1992-01-01

    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

  18. Detection of hot gas in clusters of galaxies by observation of the microwave background radiation

    International Nuclear Information System (INIS)

    Gull, S.F.; Northover, K.J.E.

    1976-01-01

    It is stated that satellite observations have indicated that many rich clusters are powerful sources of x-rays. This has been interpreted as due to either thermal bremsstrahlung from very hot gas filling the clusters or as inverse Compton scattering of photons by relativistic electrons. Spectral evidence appears to favour a thermal origin for the radiation, implying the existence of large amounts of hot gas. This gas may be a major constituent of the Universe, and independent confirmation of its existence is very important. Observations are here reported of small diminutions in the cosmic microwave background radiation in the direction of several rich clusters of galaxies. This is considered to confirm the existence of large amounts of very hot gas in these clusters and to indicate that the x-radiation is thermal bremsstrahlung and not inverse Compton emission. The observations were made in 1975/1976 using the 25m. telescope at the SRC Appleton Laboratory at a frequency of 10.6 GH2, and details are given of the technique employed. (U.K.)

  19. A Search for Hot, Diffuse Gas in Superclusters

    Science.gov (United States)

    Boughn, Stephen P.

    1998-01-01

    The HEA01 A2 full sky, 2-10 keV X-ray map was searched for diffuse emission correlated with the plane of the local supercluster of galaxies and a positive correlation was found at the 99% confidence level. The most obvious interpretation is that the local supercluster contains a substantial amount of hot (10(exp 8) OK), diffuse gas, i.e. ionized hydrogen, with a density on the order of 2 - 3 x 10(exp -6) ions per cubic centimeter. This density is about an order of magnitude larger than the average baryon density of the universe and is consistent with a supercluster collapse factor of 10. The implied total mass is of the order of 10(exp 16) times the mass of the sun and would constitute a large fraction of the baryonic matter in the local universe. This result supports current thinking that most of the ordinary matter in the universe is in the form of ionized hydrogen; however, the high temperature implied by the X-ray emission is at the top of the range predicted by most theories. The presence of a large amount of hot gas would leave its imprint on the Cosmic Microwave Background (CMB) via the Sunyaev-Zel'dovich (SZ) effect. A marginal decrement (-17 muK) was found in the COBE 4-year 53 GHz CMB map coincident with the plane of the local supercluster. Although the detection is only 1beta, the level is consistent with the SZ effect predicted from the hot gas. If these results are confirmed by future observations they will have important implications for the formation of large-scale structure in the universe. Three other projects related directly to the HEAO 1 map or the X-ray background in general benefited from this NASA grant. They are: (1) "Correlations between the Cosmic X-ray and Microwave Backgrounds: Constraints on a Cosmological Constant"; (2) "Cross-correlation of the X-ray Background with Radio Sources: Constraining the Large-Scale Structure of the X-ray Background"; and (3) "Radio and X-ray Emission Mechanisms in Advection Dominated Accretion Flow".

  20. 30 CFR 77.303 - Hot gas inlet chamber dropout doors.

    Science.gov (United States)

    2010-07-01

    ... Section 77.303 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND... employ a hot gas inlet chamber shall be equipped with drop-out doors at the bottom of the inlet chamber...

  1. Dynamic simulation for hot gas cleanup

    Energy Technology Data Exchange (ETDEWEB)

    Zeppi, C.; Berg, H.; Vitolo, S.; Tartarelli, R.; Tonini, D.; Zaccagnini, M. (ENEL CRTN, Pisa (Italy))

    1993-01-01

    Removal of sulfur compounds from hot coal gas is a necessary step during power generation operations. Metal oxides such as zinc ferrite, zinc titanate and tin oxide have been identified as promising adsorbent materials. A mathematical model capable of describing the sulfidation phase in fixed-, moving- and fluidized-bed reactors has been developed. Equations selected are sufficiently simple and numerical solutions can be obtained in a reasonable time using available computer equipment. At the same time the equations produce satisfactory agreement with experimental results. This paper presents kinetic models of spherical sorbent-particles applicable to all reactor configurations and a mathematical model limited to the moving-bed reactor. 10 refs., 5 figs.

  2. Hot-Fire Test Results of Liquid Oxygen/RP-2 Multi-Element Oxidizer-Rich Preburners

    Science.gov (United States)

    Protz, C. S.; Garcia, C. P.; Casiano, M. J.; Parton, J. A.; Hulka, J. R.

    2016-01-01

    As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. To supply the oxidizer-rich combustion products to the main injector of the integrated test article, existing subscale preburner injectors from a previous NASA-funded oxidizer-rich staged combustion engine development program were utilized. For the integrated test article, existing and newly designed and fabricated inter-connecting hot gas duct hardware were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. However, before one of the preburners was used in the integrated test article, it was first hot-fire tested at length to prove it could provide the hot exhaust gas mean temperature, thermal uniformity and combustion stability necessary to perform in the integrated test article experiment. This paper presents results from hot-fire testing of several preburner injectors in a representative combustion chamber with a sonic throat. Hydraulic, combustion performance, exhaust gas thermal uniformity, and combustion stability data are presented. Results from combustion stability modeling of these test results are described in a companion paper at this JANNAF conference, while hot-fire test results of the preburner injector in the integrated test article are described in another companion paper.

  3. HOT AND COLD GALACTIC GAS IN THE NGC 2563 GALAXY GROUP

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Jesper [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Bai, Xue-Ning [Department of Astrophysical Sciences, Peyton Hall, Princeton University, NJ 08544 (United States); Mulchaey, John S. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Van Gorkom, J. H.; Lee, Duane [Department of Astronomy, Columbia University, Mail Code 5246, 550 West 120th Street, New York, NY 10027 (United States); Jeltema, Tesla E. [UCO/Lick Observatories, 1156 High Street, Santa Cruz, CA 95064 (United States); Zabludoff, Ann I. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Wilcots, Eric [Department of Astronomy, University of Wisconsin-Madison, 475 N. Charter St., Madison, WI 53706 (United States); Martini, Paul [Department of Astronomy, 4055 McPherson Laboratory, Ohio State University, 140 West 18th Avenue, Columbus, OH (United States); Roberts, Timothy P., E-mail: jr@dark-cosmology.dk [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)

    2012-03-01

    The role of environmentally induced gas stripping in driving galaxy evolution in groups remains poorly understood. Here we present extensive Chandra and Very Large Array mosaic observations of the hot and cold interstellar medium within the members of the nearby, X-ray bright NGC 2563 group, a prime target for studies of the role of gas stripping and interactions in relatively small host halos. Our observations cover nearly all group members within a projected radius of 1.15 Mpc ({approx}1.4 R{sub vir}) of the group center, down to a limiting X-ray luminosity and H I mass of 3 Multiplication-Sign 10{sup 39} erg s{sup -1} and 2 Multiplication-Sign 10{sup 8} M{sub Sun }, respectively. The X-ray data are consistent with efficient ram pressure stripping of the hot gas halos of early-type galaxies near the group core, but no X-ray tails are seen and the limited statistics preclude strong conclusions. The H I results suggest moderate H I mass loss from the group members when compared to similar field galaxies. Six of the 20 H I-detected group members show H I evidence of ongoing interactions with other galaxies or with the intragroup medium. Suggestive evidence is further seen for galaxies with close neighbors in position-velocity space to show relatively low H I content, consistent with tidal removal of H I. The results thus indicate removal of both hot and cold gas from the group members via a combination of ram pressure stripping and tidal interactions. We also find that 16 of the 20 H I detections occur on one side of the group, reflecting an unusual morphological segregation whose origin remains unclear.

  4. Design and Fabrication of Porous Yttria-Stabilized Zirconia Ceramics for Hot Gas Filtration Applications

    Science.gov (United States)

    Shahini, Shayan

    Hot gas filtration has received growing attention in a variety of applications over the past few years. Yttria-stabilized zirconia (YSZ) is a promising candidate for such an application. In this study, we fabricated disk-type porous YSZ filters using the pore forming procedure, in which poly methyl methacrylate (PMMA) was used as the pore-forming agent. After fabricating the pellets, we characterized them to determine their potential for application as gas filters. We investigated the effect of sintering temperature, polymer particle size, and polymer-to-ceramic ratio on the porosity, pore size, gas permeability, and Vickers hardness of the sintered pellets. Furthermore, we designed two sets of experiments to investigate the robustness of the fabricated pellets--i.e., cyclic heating/cooling and high temperature exposure. This study ushers in a robust technique to fabricate such porous ceramics, which have the potential to be utilized in hot gas filtration.

  5. The Gas-Phase Formation of Methyl Formate in Hot Molecular Cores

    Science.gov (United States)

    Horn, Anne; Møllendal, Harald; Sekiguchi, Osamu; Uggerud, Einar; Roberts, Helen; Herbst, Eric; Viggiano, A. A.; Fridgen, Travis D.

    2004-08-01

    Methyl formate, HCOOCH3, is a well-known interstellar molecule prominent in the spectra of hot molecular cores. The current view of its formation is that it occurs in the gas phase from precursor methanol, which is synthesized on the surfaces of grain mantles during a previous colder era and evaporates while temperatures increase during the process of high-mass star formation. The specific reaction sequence thought to form methyl formate, the ion-molecule reaction between protonated methanol and formaldehyde followed by dissociative recombination of the protonated ion [HCO(H)OCH3]+, has not been studied in detail in the laboratory. We present here the results of both a quantum chemical study of the ion-molecule reaction between [CH3OH2]+ and H2CO as well as new experimental work on the system. In addition, we report theoretical and experimental studies for a variety of other possible gas-phase reactions leading to ion precursors of methyl formate. The studied chemical processes leading to methyl formate are included in a chemical model of hot cores. Our results show that none of these gas-phase processes produces enough methyl formate to explain its observed abundance.

  6. Preliminary Analysis of the Bundle-Duct Interaction for the fuel of SFR

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byoung Oon; Cheon, Jin Sik; Hahn, Do Hee; Lee, Chan Bock [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-10-15

    BDI (Bundle-Duct Interaction) occurs in the fuel of SFR (Sodium-cooled Fast Reactor) due to the radial expansion and bowing of a fuel pin bundle. Under the BDI condition, excess cladding strain and hot spots would occur. Therefore, BDI, which is the dominant deformation mechanisms in a fuel pin bundle, should be considered to evaluate the FBR fuel integrity. The analysis codes such as ETOILE and BMBOO, have been developed to evaluate the BDI behavior. The bundle duct interaction model is also being developed for SFR in Korea. This model is based on ANSYS. In this paper, the fuel pin configuration model for the BDI calculation was established. The preliminary analysis of the bundle-duct interaction was performed to evaluate the fuel design concept.

  7. Characterization of flow in a scroll duct

    Science.gov (United States)

    Begg, E. K.; Bennett, J. C.

    1985-01-01

    A quantitative, flow visualization study was made of a partially elliptic cross section, inward curving duct (scroll duct), with an axial outflow through a vaneless annular cutlet. The working fluid was water, with a Re(d) of 40,000 at the inlet to the scroll duct, this Reynolds number being representative of the conditions in an actual gas turbine scroll. Both still and high speed moving pictures of fluorescein dye injected into the flow and illuminated by an argon ion laser were used to document the flow. Strong secondary flow, similar to the secondary flow in a pipe bend, was found in the bottom half of the scroll within the first 180 degs of turning. The pressure field set up by the turning duct was strong enough to affect the inlet flow condition. At 90 degs downstream, the large scale secondary flow was found to be oscillatory in nature. The exit flow was nonuniform in the annular exit. By 270 degs downstream, the flow appeared unorganized with no distinctive secondary flow pattern. Large scale structures from the upstream core region appeared by 90 degs and continued through the duct to reenter at the inlet section.

  8. Particulate hot gas stream cleanup technical issues

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.; Snyder, T.R.

    1999-09-30

    The analyses of hot gas stream cleanup particulate samples and descriptions of filter performance studied under this contract were designed to address problems with filter operation that have been linked to characteristics of the collected particulate matter. One objective of this work was to generate an interactive, computerized data bank of the key physical and chemical characteristics of ash and char collected from operating advanced particle filters and to relate these characteristics to the operation and performance of these filters. The interactive data bank summarizes analyses of over 160 ash and char samples from fifteen pressurized fluidized-bed combustion and gasification facilities utilizing high-temperature, high pressure barrier filters.

  9. Gas turbine engine with supersonic compressor

    Science.gov (United States)

    Roberts, II, William Byron; Lawlor, Shawn P.

    2015-10-20

    A gas turbine engine having a compressor section using blades on a rotor to deliver a gas at supersonic conditions to a stator. The stator includes one or more of aerodynamic ducts that have converging and diverging portions for deceleration of the gas to subsonic conditions and to deliver a high pressure gas to combustors. The aerodynamic ducts include structures for changing the effective contraction ratio to enable starting even when designed for high pressure ratios, and structures for boundary layer control. In an embodiment, aerodynamic ducts are provided having an aspect ratio of two to one (2:1) or more, when viewed in cross-section orthogonal to flow direction at an entrance to the aerodynamic duct.

  10. Confined zone dispersion flue gas desulfurization demonstration. Quarterly report No. 8, August 17, 1992--November 16, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-27

    The CZD process involves injecting a finely atomized slurry of reactive lime into the flue gas duct work of a coal-fired utility boiler. The principle of the confined zone is to form a wet zone of slurry droplets in the middle of the duct confined in an envelope of hot gas between the wet zone and the duct walls. The lime slurry reacts with part of the SO{sub 2} in the gas, and the reaction products dry to form solid particles. A solids collector, typically an electrostatic precipitator (ESP) downstream from the point of injection, captures the reaction products along with the fly ash entrained in the flue gas. The goal of this demonstration is to prove the technical and economic feasibility of the CZD technology on a commercial scale. The process is expected to achieve 50% SO{sub 2} removal at lower capital and O&M costs than other systems. To achieve its objectives, the project is divided into the following three phases: Phase 1: Design and Permitting, Phase 2: Construction and Start-up, Phase 3: Operation and Disposition. Phase 1 activities were completed on January 31, 1991. Phase 2 activities were essentially concluded on July 31, 1991, and Phase 3a, Parametric Testing, was initiated on July 1, 1991. This Quarterly Technical Progress Report covers Phase 3b activities from August 17, 1992 through November 16, 1992.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Absorption signatures of warm-hot gas at low redshift : Ne VIII

    NARCIS (Netherlands)

    Tepper-García, T

    2013-01-01

    At z {lt} 1 a large fraction of the baryons is thought to reside in diffuse gas that has been shock-heated to high temperatures (10$^{5}$-10$^{6}$ K). Absorption by the 770.41, 780.32 å doublet of Ne VIII in quasar spectra represents a unique tool to study this elusive warm-hot phase. We have

  13. X(3872 production and absorption in a hot hadron gas

    Directory of Open Access Journals (Sweden)

    L.M. Abreu

    2016-10-01

    Full Text Available We calculate the time evolution of the X(3872 abundance in the hot hadron gas produced in the late stage of heavy ion collisions. We use effective field Lagrangians to obtain the production and dissociation cross sections of X(3872. In this evaluation we include diagrams involving the anomalous couplings πD⁎D¯⁎ and XD¯⁎D⁎ and also the couplings of the X(3872 with charged D and D⁎ mesons. With these new terms the X(3872 interaction cross sections are much larger than those found in previous works. Using these cross sections as input in rate equations, we conclude that during the expansion and cooling of the hadronic gas, the number of X(3872, originally produced at the end of the mixed QGP/hadron gas phase, is reduced by a factor of 4.

  14. Durable zinc ferrite sorbent pellets for hot coal gas desulfurization

    Science.gov (United States)

    Jha, Mahesh C.; Blandon, Antonio E.; Hepworth, Malcolm T.

    1988-01-01

    Durable, porous sulfur sorbents useful in removing hydrogen sulfide from hot coal gas are prepared by water pelletizing a mixture of fine zinc oxide and fine iron oxide with inorganic and organic binders and small amounts of activators such as sodium carbonate and molybdenite; the pellets are dried and then indurated at a high temperature, e.g., 1800.degree. C., for a time sufficient to produce crush-resistant pellets.

  15. Hot gas in clusters of galaxies, cosmic microwave background radiation and cosmology

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Presence of the hot (kTe ~ 3 - 10 KeV) rarefied gas in the clusters of galaxies (most massive gravitationally bound objects in the Universe) leads to the appearance of  "shadows"  in the angular distribution of the Cosmic Microwave Background (CMB) Radiation and permits to measure the peculiar velocities of these clusters relative to the unique coordinate frame where CMB is isotropic. I plan to describe the physics leading to these observational effects. Planck spacecraft, ground based South Pole and Atacama Cosmology Telescopes discovered recently more than two thousand of unknown before Clusters of Galaxies at high redshifts detecting these "shadows" and traces of kinematic effect, demonstrating the correlation of the hot gas velocities with mass concentrations on large scales. Giant ALMA interferometer in Atacama desert resolved recently strong shocks between merging clusters of galaxies. Newly discovered clusters of galaxies permit to study the rate of growth of the large scale structur...

  16. Hot-Fire Test Results of an Oxygen/RP-2 Multi-Element Oxidizer-Rich Staged-Combustion Integrated Test Article

    Science.gov (United States)

    Hulka, J. R.; Protz, C. S.; Garcia, C. P.; Casiano, M. J.; Parton, J. A.

    2016-01-01

    As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. For the thrust chamber assembly of the test article, several configurations of new main injectors, using relatively conventional gas-centered swirl coaxial injector elements, were designed and fabricated. The design and fabrication of these main injectors are described in a companion paper at this JANNAF meeting. New ablative combustion chambers were fabricated based on hardware previously used at NASA for testing at similar size and pressure. An existing oxygen/RP-1 oxidizer-rich subscale preburner injector from a previous NASA-funded program, along with existing and new inter-connecting hot gas duct hardware, were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. Results from independent hot-fire tests of the preburner injector in a combustion chamber with a sonic throat are described in companion papers at this JANNAF conference. The resulting integrated test article - which includes the preburner, inter-connecting hot gas duct, main injector, and ablative combustion chamber - was assembled at Test Stand 116 at the East Test Area of the NASA Marshall Space Flight Center. The test article was well instrumented with static and dynamic pressure, temperature, and acceleration sensors to allow the collected data to be used for

  17. A gas production system from methane hydrate layers by hot water injection and BHP control with radial horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Yamakawa, T.; Ono, S.; Iwamoto, A.; Sugai, Y.; Sasaki, K. [Kyushu Univ., Fukuoka, Fukuoka (Japan)

    2010-07-01

    Reservoir characterization of methane hydrate (MH) bearing turbidite channel in the eastern Nankai Trough, in Japan has been performed to develop a gas production strategy. This paper proposed a gas production system from methane hydrate (MH) sediment layers by combining the hot water injection method and bottom hole pressure control at the production well using radial horizontal wells. Numerical simulations of the cylindrical homogeneous MH layer model were performed in order to evaluate gas production characteristics by the depressurization method with bottom hole pressure control. In addition, the effects of numerical block modeling and averaging physical properties of MH layers were presented. According to numerical simulations, combining the existing production system with hot water injection and bottom hole pressure control results in an outward expansion of the hot water chamber from the center of the MH layer with continuous gas production. 10 refs., 15 figs.

  18. Studying gas-sheared liquid film in horizontal rectangular duct with laser-induced fluorescence technique

    Science.gov (United States)

    Cherdantsev, Andrey; Hann, David; Azzopardi, Barry

    2013-11-01

    High-speed LIF-technique is applied to study gas-sheared liquid film in horizontal rectangular duct with 161 mm width. Instantaneous distributions of film thickness resolved in both longitudinal and transverse coordinates were obtained with a frequency of 10 kHz and spatial resolution from 0.125 mm to 0.04 mm. Processes of generation of fast and slow ripples by disturbance waves are the same as described in literature for downwards annular pipe flow. Disturbance waves are often localized by transverse coordinate and may have curved or slanted fronts. Fast ripples, covering disturbance waves, are typically horseshoe-shaped and placed in staggered order. Their characteristic transverse size is of order 1 cm and it decreases with gas velocity. Entrainment of liquid from film surface can also be visualized. Mechanisms of ripple disruption, known as ``bag break-up'' and ``ligament break-up,'' were observed. Both mechanisms may occur on the same disturbance waves. Various scenarios of droplet deposition on the liquid film are observed, including the impact, slow sinking and bouncing, characterized by different outcome of secondary droplets or entrapped bubbles. Number and size of bubbles increase greatly inside the disturbance waves. Both quantities increase with gas and liquid flow rates. EPSRC Programme Grant MEMPHIS (EP/K003976/1), and Roll-Royce UTC (Nottingham, for access to flow facility).

  19. Bile Duct Exploration

    Science.gov (United States)

    ... Home / Health Library / Diagnostics & Testing / Bile Duct Exploration Bile Duct Exploration Common bile duct exploration is a ... Test Details Results and Follow-Up What is bile, and what is bile duct exploration? Bile is ...

  20. Numerical study of the generation of runaway electrons in a gas diode with a hot channel

    Energy Technology Data Exchange (ETDEWEB)

    Lisenkov, V. V., E-mail: lisenkov@iep.uran.ru [Institute of Electrophysics UrB RAS, 106 Amundsena St., Ekaterinburg 620012 (Russian Federation); Ural Federal University, 19 Mira St., Ekaterinburg 620002 (Russian Federation); Shklyaev, V. A., E-mail: shklyaev@to.hcei.tsc.ru [Institute of High Current Electronics SD RAS, 2/3 Akademichesky Avenue, 634055 Tomsk (Russian Federation); National Research Tomsk Polytechnic University, 30 Lenin Avenue, 634050 Tomsk (Russian Federation)

    2015-11-15

    A new method for increasing the efficiency of runaway electron beam generation in atmospheric pressure gas media has been suggested and theoretically proved. The method consists of creating a hot region (e.g., a spark channel or a laser plume) with a decreased numerical density of gas molecules (N) near the cathode. In this method, the ratio E/N (E—electric field strength) is increased by decreasing N instead of increasing E, as has been done in the past. The numerical model that is used allows the simultaneous calculation of the formation of a subnanosecond gas discharge and the generation of runaway electrons in gas media. The calculations have demonstrated the possibility of obtaining current pulses of runaway electrons with amplitudes of hundred of amperes and durations of more than 100 ps. The influence of the hot channel geometry on the parameters of the generated beam has been investigated.

  1. Hot gas path component cooling system

    Science.gov (United States)

    Lacy, Benjamin Paul; Bunker, Ronald Scott; Itzel, Gary Michael

    2014-02-18

    A cooling system for a hot gas path component is disclosed. The cooling system may include a component layer and a cover layer. The component layer may include a first inner surface and a second outer surface. The second outer surface may define a plurality of channels. The component layer may further define a plurality of passages extending generally between the first inner surface and the second outer surface. Each of the plurality of channels may be fluidly connected to at least one of the plurality of passages. The cover layer may be situated adjacent the second outer surface of the component layer. The plurality of passages may be configured to flow a cooling medium to the plurality of channels and provide impingement cooling to the cover layer. The plurality of channels may be configured to flow cooling medium therethrough, cooling the cover layer.

  2. Studying the instantaneous velocity field in gas-sheared liquid films in a horizontal duct

    Science.gov (United States)

    Vasques, Joao; Tokarev, Mikhail; Cherdantsev, Andrey; Hann, David; Hewakandamby, Buddhika; Azzopardi, Barry

    2016-11-01

    In annular flow, the experimental validation of the basic assumptions on the liquid velocity profile is vital for developing theoretical models of the flow. However, the study of local velocity of liquid in gas-sheared films has proven to be a challenging task due to the highly curved and disturbed moving interface of the phases, small scale of the area of interrogation, high velocity gradients and irregular character of the flow. This study reports on different optical configurations and interface-tracking methods employed in a horizontal duct in order to obtain high-resolution particle image velocimetry (PIV) data in such types of complex flows. The experimental envelope includes successful measurements in 2D and 3D waves regimes, up to the disturbance wave regime. Preliminary data show the presence of complex structures in the liquid phase, which includes re-circulation areas below the liquid interface due to the gas-shearing action, together with non-uniform transverse movements of the liquid phase close to the wall due to the presence of 3D waves at the interface. With the aid of the moving interface-tracking, PIV, time-resolved particle-tracking velocimetry and vorticity measurements were performed.

  3. Energy flux of hot atoms

    International Nuclear Information System (INIS)

    Wotzak, G.P.; Kostin, M.D.

    1976-01-01

    The process in which hot atoms collide with thermal atoms of a gas, transfer kinetic energy to them, and produce additional hot atoms is investigated. A stochastic method is used to obtain numerical results for the spatial and time dependent energy flux of hot atoms in a gas. The results indicate that in hot atom systems a front followed by an intense energy flux of hot atoms may develop

  4. Detection of Hot Halo Gets Theory Out of Hot Water

    Science.gov (United States)

    2006-02-01

    Scientists using NASA's Chandra X-ray Observatory have detected an extensive halo of hot gas around a quiescent spiral galaxy. This discovery is evidence that galaxies like our Milky Way are still accumulating matter from the gradual inflow of intergalactic gas. "What we are likely witnessing here is the ongoing galaxy formation process," said Kristian Pedersen of the University of Copenhagen, Denmark, and lead author of a report on the discovery. Chandra observations show that the hot halo extends more than 60,000 light years on either side of the disk of the galaxy known as NGC 5746. The detection of such a large halo alleviates a long-standing problem for the theory of galaxy formation. Spiral galaxies are thought to form from enormous clouds of intergalactic gas that collapse to form giant, spinning disks of stars and gas. Chandra X-ray Image of NGC 5746 Chandra X-ray Image of NGC 5746 One prediction of this theory is that large spiral galaxies should be immersed in halos of hot gas left over from the galaxy formation process. Hot gas has been detected around spiral galaxies in which vigorous star formation is ejecting matter from the galaxy, but until now hot halos due to infall of intergalactic matter have not been detected. "Our observations solve the mystery of the missing hot halos around spiral galaxies," said Pedersen. "The halos exist, but are so faint that an extremely sensitive telescope such as Chandra is needed to detect them." DSS Optical Image of NGC 5746 DSS Optical Image of NGC 5746 NGC 5746 is a massive spiral galaxy about a 100 million light years from Earth. Its disk of stars and gas is viewed almost edge-on. The galaxy shows no signs of unusual star formation, or energetic activity from its nuclear region, making it unlikely that the hot halo is produced by gas flowing out of the galaxy. "We targeted NGC 5746 because we thought its distance and orientation would give us the best chance to detect a hot halo caused by the infall of

  5. The Klinger hot gas double axial valve

    International Nuclear Information System (INIS)

    Kruschik, J.; Hiltgen, H.

    1984-01-01

    The Klinger hot gas valve is a medium controlled double axial valve with advanced design features and safety function. It was first proposed by Klinger early in 1976 for the PNP-Project as a containment shut-off for hot helium (918 deg. C and 42 bar), because a market research has shown that such a valve is not state of present techniques. In the first stage of development a feasibility study had to be made by detailed design, calculation and by basic experiments for key components in close collaboration with Interatom/GHT. This was the basis for further design, calculation, construction and experimental work for such a valve prototype within the new development contract. The stage of knowledge to that time revealed the following key priority development areas: Finite element stress analysis for the highly stressed high temperature main components; development of an insulation layout; Detailed experimental tests of functionally important structural components or units of the valve, partly at Klingers (gasstatic bearings, flexible metallic sealing element, aerodynamic and thermohydraulic tests), partly at Interatom (actuator unit and also gasstatic bearings), partly at HRB in Juelich (flexible metallic sealing system, aerodynamic and thermohydraulic tests); Design of a test valve for experimental work in the KVK (test circuit at Interatom) for evaluation of temperature distribution and reliability of operation; Design of a prototype and extensive testing in the KVK

  6. Hot Gas Particulate Cleaning Technology Applied for PFBC/IGFC -The Ceramic Tube Filter (CTF) and Metal Filter-

    Energy Technology Data Exchange (ETDEWEB)

    Sasatsu, H; Misawa, N; Kobori, K; Iritani, J

    2002-09-18

    Coal is a fossil fuel abundant and widespread all over world. It is a vital resource for energy security, because the supply is stable. However, its CO2 emission per unit calorific value is greater than that of other fossil fuels. It is necessary to develop more efficient coal utilization technologies to expand the coal utilization that meets the social demand for better environment. The Pressurized Fluidized Bed Combustion (PFBC) combined cycle has become a subject of world attention in terms of better plant operation, improved plant efficiency, lower flue gas emission and fuel flexibility. The gas turbine, one of the most important components in the PFBC, is eager for a hot gas (approximately 650-850C) cleaning system in order to eliminate the severe erosion problem with the less thermal loss. The cyclone is most popular system for a hot gas cleaning, however, the severe damage for gas turbine blades by highly concentrated fine fly ash from PFBC boiler is reported.

  7. Detection device for off-gas system accidents

    International Nuclear Information System (INIS)

    Kubota, Ryuji; Tsuruoka, Ryozo; Yamanari, Shozo.

    1984-01-01

    Purpose: To rapidly isolate the off-gas system by detecting the off-gas system failure accident in a short time. Constitution: Radiation monitors are disposed to ducts connecting an exhaust gas area and an air conditioning system as a portion of a turbine building. The ducts are disposed independently such that they ventilate only the atmosphere in the exhaust gas area and do not mix the atmosphere in the turbine building. Since radioactivity issued upon off-gas accidents to the exhaust gas area is sucked to the duct, it can be detected by radiation detection monitors in a short time after the accident. Further, since the operator judges it as the off-gas system accident, the off-gas system can be isolated in a short time after the accident. (Moriyama, K.)

  8. Thermal behavior of the duct applied functionally graded material

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jung Sun; Yoon, Dong Young; Im, Jong Bin [Hankuk Aviation Univ., Goyang (Korea, Republic of)

    2004-07-01

    In Unmanned Aerial Vehicles (UAV), the high temperature results from friction among the air, combustion of fuel in engine and combustion gas of a nozzle. The high temperature may cause serious damages in UAV structure. The Functionally Graded Material(FGM) is chosen as a material of the engine duct structure. Thermal stress analysis of FGM is performed in this paper. FGM is composed of two constituent materials that are mixed up according to the specific volume fraction distribution in order to withstand high temperature. Therefore, hoop stress, axial stress and shear stress of duct with 2 layers, 4 layers and 8 layers FGM are compared and analyzed respectively. In addition, the creep behavior of FGM used in duct structure of an engine is analyzed for better understanding of FGM characteristics.

  9. Amine-based post-combustion CO2 capture in air-blown IGCC systems with cold and hot gas clean-up

    International Nuclear Information System (INIS)

    Giuffrida, A.; Bonalumi, D.; Lozza, G.

    2013-01-01

    Highlights: • Hot fuel gas clean-up is a very favorable technology for IGCC concepts. • IGCC net efficiency reduces to 41.5% when realizing post-combustion CO 2 capture. • Complex IGCC layouts are necessary if exhaust gas recirculation is realized. • IGCC performance does not significantly vary with exhaust gas recirculation. - Abstract: This paper focuses on the thermodynamic performance of air-blown IGCC systems with post-combustion CO 2 capture by chemical absorption. Two IGCC technologies are investigated in order to evaluate two different strategies of coal-derived gas clean-up. After outlining the layouts of two power plants, the first with conventional cold gas clean-up and the second with hot gas clean-up, attention is paid to the CO 2 capture station and to issues related to exhaust gas recirculation in combined cycles. The results highlight that significant improvements in IGCC performance are possible if hot coal-derived gas clean-up is realized before the syngas fuels the combustion turbine, so the energy cost of CO 2 removal in an amine-based post-combustion mode is less strong. In particular, IGCC net efficiency as high as 41.5% is calculated, showing an interesting potential if compared to the one of IGCC systems with pre-combustion CO 2 capture. Thermodynamic effects of exhaust gas recirculation are investigated as well, even though IGCC performance does not significantly vary against a more complicated plant layout

  10. Shear stress from hot-film sensors in unsteady gas flow

    International Nuclear Information System (INIS)

    Cole, K.D.

    1991-01-01

    In this paper a data analysis procedure is proposed for obtaining unsteady wall shear stress from flush-mounted hot-film anemometer measurements. The method is based on a two-dimensional heat transfer model of the unsteady heat transfer in both the hot-film sensor and in the gas flow. The sensor thermal properties are found from preliminary calibration experiments at zero flow. Numerical experiments are used to demonstrate the data analysis method using simulated sensor signals that are corrupted with noise. The numerical experiments show that noise in the data propagates into the results so that data smoothing may be important in analyzing experimental data. Because the data analysis procedure is linear, a linear digital filter is constructed that could be used for processing large amounts of experimental data. However, further refinements will be needed before the method can be applied to experimental data

  11. Dust characterisation for hot gas filters

    Energy Technology Data Exchange (ETDEWEB)

    Dockter, B.; Erickson, T.; Henderson, A.; Hurley, J.; Kuehnel, V.; Katrinak, K.; Nowok, J.; O`Keefe, C.; O`Leary, E.; Swanson, M.; Watne, T. [University of North Dakota, Grand Forks, ND (United States). Energy and Environmental Research Center (UNDEERC)

    1998-03-01

    Hot gas filtration to remove particulates from the gas flow upstream of the gas turbine is critical to the development of many of the advanced coal-fired power generation technologies such as the Air Blown Gasification Cycle (ABGC), a hybrid gasification combined cycle being developed in the UK. Ceramic candle filters are considered the most promising technology for this purpose. Problems of mechanical failure and of `difficult-to-clean` dusts causing high pressure losses across the filter elements need to be solved. The project investigated the behaviour of high-temperature filter dusts, and the factors determining the ease with which they can be removed from filters. The high-temperature behaviour of dusts from both combustion and gasification systems was investigated. Dust samples were obtained from full-scale demonstration and pilot-scale plant operating around the world. Dust samples were also produced from a variety of coals, and under several different operating conditions, on UNDEERC`s pilot-scale reactor. Key factors affecting dust behaviour were examined, including: the rates of tensile strength developing in dust cakes; the thermochemical equilibria pertaining under filtration conditions; dust adhesivity on representative filter materials; and the build-up and cleaning behaviour of dusts on representative filter candles. The results obtained confirmed the importance of dust temperature, dust cake porosity, cake liquid content, and particle size distribution in determining the strength of a dust cake. An algorithm was developed to indicate the likely sticking propensity of dusts as a function of coal and sorbent composition and combustion conditions. This algorithm was incorporated into a computer package which can be used to judge the degree of difficulty in filter cleaning that can be expected to arise in a real plant based on operating parameters and coal analyzes. 6 figs.

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

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 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 duct...

  13. On-line ultrasonic gas entrainment monitor

    International Nuclear Information System (INIS)

    Day, C.K.; Pedersen, H.N.

    1978-01-01

    Apparatus employing ultrasonic energy for detecting and measuring the quantity of gas bubbles present in liquids being transported through pipes is described. An ultrasonic transducer is positioned along the longitudinal axis of a fluid duct, oriented to transmit acoustic energy radially of the duct around the circumference of the enclosure walls. The back-reflected energy is received centrally of the duct and interpreted as a measure of gas entrainment. One embodiment employs a conical reflector to direct the transmitted acoustic energy radially of the duct and redirect the reflected energy back to the transducer for reception. A modified embodiment employs a cylindrical ultrasonic transducer for this purpose

  14. Detection of leaks for radioactive tracer in marine duct for transport of liquefied petroleum gas; Deteccion de fugas por radiotrazado en ducto marino para transporte de gas LP

    Energy Technology Data Exchange (ETDEWEB)

    Robles P, E. F.; Benitez S, J. A.; Torre O, J. de la; Cruz S, E. de la; Molina, G.; Hernandez C, J. E.; Flores M, J. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e mail: efrp@nuclear.inin.mx

    2008-07-01

    In this work the aplication in the oil industry of the technique of radioactive tracer appears for the detection of internal leaks in a submarine duct that gives service as it lines of receipt of liquefied petroleum gas (Gas LP) located in the Mexican coast of the Pacific Ocean. This system of marine pipe is a consistent arrangement of a duct interior of 0.254 m (10 inches) of nominal diameter (N.D.) of steel to the carbon for cryogenic service ASTM A 333, Grade 6, schedule 30, isolated thermally with foam of polyurethane and shielding in a steel tube to the carbon ASTM A 53 Grade A, of 0.508 m (20 inches) N. D., schedule 20, which is recovered by a ballast encircling of concrete of 0.0508 m (2 inches) of thickness, reinforced with mesh metallic, and that 1315 m runs on the marine stratum to a maximum depth of 12.5 m. For the detection of leaks by radiotracer it was used as tracer the radioactive isotope La-140 produced in the TRIGA Mark III Experimental Reactor of the National Institute of Nuclear Research, starting from stable lanthanum nitrate (La(NO{sub 3}){sub 3} 6H{sub 2}O), with an activity of 100 mCi, the one which after having been made logistics tasks, given very particular sea maneuvers and due to the conditions of the work place, in the interior tube was injected in two subsequent stages to cover both duct senses; from earth and from the marine end respectively, there being used fresh water like transport way and submergible sodium iodide detectors (NaI) for the rake of the La-140. At the end of the journeys of pursuit of the radiotracer, it was determine the presence of three leaks points located in the break area of the marine surf to 360 m, 450 m and 495 m of distance of a reference point located in the beach section named Trap of Devils. (Author)

  15. Proof tests of irradiated and unirradiated EBR-II subassembly ducts

    International Nuclear Information System (INIS)

    Ruther, W.E.; Chopra, P.S.; Lambert, J.D.B.

    1977-01-01

    A series of dynamic pressure tests have been conducted within EBR-II subassembly ducts. The tests were designed to simulate bursting of a driver-fuel element in a cluster of such elements at their burnup limit during off-normal conditions in EBR-II. The major objective of the tests was to assure that such failure, which might cause rapid release of stored fission gas, would not deform or otherwise damage subassembly ducts in a way that would hinder movement of a control rod. The test results are described

  16. Study of the Milky Way's hot coronal gas with its dwarf galaxies

    Science.gov (United States)

    Pasetto, Stefano; Cropper, Mark; Fujita, Yutaka; Chiosi, Cesare; Grebel, Eva K.

    2016-08-01

    A large amount (5 × 1010 M⊙) of hot gas is thought to exist in an extended (~ 200 kpc) hot diffuse halo around the Milky Way. We investigate the competitive role of the different dissipative phenomena acting on the onset of star formation of this gravitationally bound systems in this external environment. Ram pressure, Kelvin-Helmholtz and Rayleigh- Taylor instabilities, and tidal forces are accounted for separately in an analytical framework and compared in their role in influencing the star forming regions. We present an analytical criterion to elucidate the dependence of star formation in a spherical stellar system on its surrounding environment, useful in observational applications as well as theoretical interpretations of numerical results. We consider the different signatures of these phenomena in synthetically realized colour-magnitude diagrams (CMDs) of the orbiting system, thus investigating the detectability limits and relevance of these different effects for future observational projects. The theoretical framework developed has direct applications to the cases of our MW system as well as dwarf galaxies in galaxy clusters or any primordial gas-rich star cluster of stars orbiting within its host galaxy.

  17. The influence of streamwise vortices on turbulent heat transfer in rectangular ducts with various aspect ratios

    International Nuclear Information System (INIS)

    Choi, Hang Seok; Park, Tae Seon

    2013-01-01

    Highlights: ► With changing aspect ratio, the effect of secondary flows on the turbulent heat transfer is scrutinized by a LES. ► The conditional sampling technique of instantaneous near-wall streamwise vortices is developed. ► Clockwise and counter-clockwise rotating streamwise vortices are sampled and discussed with the wall heat transfer. ► The hot-sweep motions of CW and CCW vortices clearly appear with increasing aspect ratio. -- Abstract: The effect of aspect ratio of rectangular duct on the turbulent flow and heat transfer is very important for its engineering applications. But the turbulent thermal fields have not been fundamentally scrutinized in spite of its engineering significance especially for cooling device. Hence, in the present study, large eddy simulation is applied to the turbulent flow and heat transfer in rectangular ducts with varying aspect ratio. The turbulent statistics of the flow and thermal quantities are calculated and the characteristics of wall Nusselt number are investigated for each rectangular duct. Especially, to scrutinize near-wall streamwise vortices, a conditional sampling technique is developed and adopted. Clockwise and counter-clockwise rotating streamwise vortices are sampled and the probability density function of the vortex circulation Reynolds number and wall Nusselt number are calculated. From the results, the time-averaged secondary flow caused by instantaneous vortical motions has a great effect on the heat and momentum transport of the flow in the rectangular ducts. Hence, the wall Nusselt number is enhanced near the downwash flow region of the secondary flow. However, with increasing the aspect ratio, the effects of the hot-sweep flow of the clockwise and counter-clockwise rotating vortices become equally dominant near the wall normal bisector of the ducts. During time averaging process, these two counter-rotating vortices are canceled out each other diminishing a secondary flow but they still enhance the

  18. Evaluation of mixing downstream of tees in duct systems with respect to single point representative air sampling.

    Science.gov (United States)

    Kim, Taehong; O'Neal, Dennis L; Ortiz, Carlos

    2006-09-01

    Air duct systems in nuclear facilities must be monitored with continuous sampling in case of an accidental release of airborne radionuclides. The purpose of this work is to identify the air sampling locations where the velocity and contaminant concentrations fall below the 20% coefficient of variation required by the American National Standards Institute/Health Physics Society N13.1-1999. Experiments of velocity and tracer gas concentration were conducted on a generic "T" mixing system which included combinations of three sub ducts, one main duct, and air velocities from 0.5 to 2 m s (100 to 400 fpm). The experimental results suggest that turbulent mixing provides the accepted velocity coefficients of variation after 6 hydraulic diameters downstream of the T-junction. About 95% of the cases achieved coefficients of variation below 10% by 6 hydraulic diameters. However, above a velocity ratio (velocity in the sub duct/velocity in the main duct) of 2, velocity profiles were uniform in a shorter distance downstream of the T-junction as the velocity ratio went up. For the tracer gas concentration, the distance needed for the coefficients of variation to drop 20% decreased with increasing velocity ratio due to the sub duct airflow momentum. The results may apply to other duct systems with similar geometries and, ultimately, be a basis for selecting a proper sampling location under the requirements of single point representative sampling.

  19. Experimental study on a comparison of typical premixed combustible gas-air flame propagation in a horizontal rectangular closed duct.

    Science.gov (United States)

    Jin, Kaiqiang; Duan, Qiangling; Liew, K M; Peng, Zhongjing; Gong, Liang; Sun, Jinhua

    2017-04-05

    Research surrounding premixed flame propagation in ducts has a history of more than one hundred years. Most previous studies focus on the tulip flame formation and flame acceleration in pure gas fuel-air flame. However, the premixed natural gas-air flame may show different behaviors and pressure dynamics due to its unique composition. Natural gas, methane and acetylene are chosen here to conduct a comparison study on different flame behaviors and pressure dynamics, and to explore the influence of different compositions on premixed flame dynamics. The characteristics of flame front and pressure dynamics are recorded using high-speed schlieren photography and a pressure transducer, respectively. The results indicate that the compositions of the gas mixture greatly influence flame behaviors and pressure. Acetylene has the fastest flame tip speed and the highest pressure, while natural gas has a faster flame tip speed and higher pressure than methane. The Bychkov theory for predicting the flame skirt motion is verified, and the results indicate that the experimental data coincide well with theory in the case of equivalence ratios close to 1.00. Moreover, the Bychkov theory is able to predict flame skirt motion for acetylene, even outside of the best suitable expansion ratio range of 6

  20. Origin of warm and hot gas emission from low-mass protostars: Herschel-HIFI observations of CO J = 16-15

    DEFF Research Database (Denmark)

    Kristensen, Lars Egstrøm; Van Dishoeck, E. F.; Mottram, J. C.

    2017-01-01

    Context. Through spectrally unresolved observations of high-J CO transitions, Herschel Photodetector Array Camera and Spectrometer (PACS) has revealed large reservoirs of warm (300 K) and hot (700 K) molecular gas around low-mass protostars. The excitation and physical origin of this gas is still...... in cooling molecular H2-poor gas just prior to the onset of H2 formation. High spectral resolution observations of highly excited CO transitions uniquely shed light on the origin of warm and hot gas in low-mass protostellar objects....... not understood. Aims. We aim to shed light on the excitation and origin of the CO ladder observed toward protostars, and on the water abundance in different physical components within protostellar systems using spectrally resolved Herschel-HIFI data. Methods. Observations are presented of the highly excited CO...

  1. Particulate hot gas stream cleanup technical issues

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    This is the tenth in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic bed filter elements. Task I is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task I during the past quarter, analyses were performed on a particulate sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota Energy and Environmental Research Center. Analyses are in progress on ash samples from the Advanced Particulate Filter (APF) at the Pressurized Fluidized-Bed Combustor (PFBC) that was in operation at Tidd and ash samples from the Pressurized Circulating Fluid Bed (PCFB) system located at Karhula, Finland. A site visit was made to the Power Systems Development Facility (PSDF) to collect ash samples from the filter vessel and to document the condition of the filter vessel with still photographs and videotape. Particulate samples obtained during this visit are currently being analyzed for entry into the Hot Gas Cleanup (HGCU) data base. Preparations are being made for a review meeting on ash bridging to be held at Department of Energy Federal Energy Technology Center - Morgantown (DOE/FETC-MGN) in the near future. Most work on Task 2 was on hold pending receipt of additional funds; however, creep testing of Schumacher FT20 continued. The creep tests on Schumacher FT20 specimens just recently ended and data analysis and comparisons to other data are ongoing. A summary and analysis of these creep results will be sent out shortly. Creep

  2. Transcystic duct treatment of common bile duct stones

    International Nuclear Information System (INIS)

    Amberg, J.R.; Chun, G.

    1981-01-01

    Successful removal of 2 retained common bile duct stones following cholecystostomy is described. With the use of the steerable catheter and the wire basket, one stone was crushed and the second was extracted in retrograde fashion through the cystic duct and gallbladder. (orig.)

  3. HERSCHEL* FAR-INFRARED SPECTROSCOPY OF THE GALACTIC CENTER. HOT MOLECULAR GAS: SHOCKS VERSUS RADIATION NEAR Sgr A

    Energy Technology Data Exchange (ETDEWEB)

    Goicoechea, Javier R.; Etxaluze, M.; Cernicharo, J.; Bell, T. A. [Departamento de Astrofisica, Centro de Astrobiologia, CSIC-INTA, Carretera de Ajalvir, Km 4, Torrejon de Ardoz, E-28850 Madrid (Spain); Gerin, M.; De Luca, M.; Encrenaz, P. [LERMA, UMR 8112 du CNRS, Observatoire de Paris, Ecole Normale Superieure (France); Neufeld, D. A.; Indriolo, N. [Johns Hopkins University, Baltimore, MD 21218 (United States); Contursi, A. [Max-Planck-Institut fuer extraterrestrische Physik (MPE), Postfach 1312, D-85741 Garching (Germany); Lis, D. C. [California Institute of Technology, Pasadena, CA 91125 (United States); Polehampton, E. T. [RAL Space, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Sonnentrucker, P., E-mail: jr.goicoechea@cab.inta-csic.es [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

    2013-05-20

    We present a {approx}52-671 {mu}m spectral scan toward Sgr A* taken with the PACS and SPIRE spectrometers on board Herschel. The achieved angular resolution allows us to separate, for the first time at far-IR wavelengths, the emission toward the central cavity (gas in the inner central parsec of the galaxy) from that of the surrounding circumnuclear disk. The spectrum toward Sgr A* is dominated by strong [O III], [O I], [C II], [N III], [N II], and [C I] fine-structure lines (in decreasing order of luminosity) arising in gas irradiated by UV photons from the central stellar cluster. In addition, rotationally excited lines of {sup 12}CO (from J = 4-3 to 24-23), {sup 13}CO, H{sub 2}O, OH, H{sub 3}O{sup +}, HCO{sup +}, and HCN, as well as ground-state absorption lines of OH{sup +}, H{sub 2}O{sup +}, H{sub 3}O{sup +}, CH{sup +}, H{sub 2}O, OH, HF, CH, and NH are detected. The excitation of the {sup 12}CO ladder is consistent with a hot isothermal component at T{sub k} {approx_equal} 10{sup 3.1} K and n(H{sub 2}) {approx}< 10{sup 4} cm{sup -3}. It is also consistent with a distribution of temperature components at higher density with most CO at T{sub k} {approx}< 300 K. The detected molecular features suggest that, at present, neither very enhanced X-ray nor cosmic-ray fluxes play a dominant role in the heating of the hot molecular gas. The hot CO component (either the bulk of the CO column or just a small fraction depending on the above scenario) results from a combination of UV- and shock-driven heating. If irradiated dense clumps/clouds do not exist, shocks likely dominate the heating of the hot molecular gas. This is consistent with the high-velocity gas detected toward Sgr A*.

  4. Regeneration of iron oxide containing pellets used for hot gas clean up

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, A.; Heeney, P.; Furimsky, E. (CANMET, Ottawa, Ontario (Canada). Energy Research Laboratories)

    1989-09-01

    Four iron-containing pelletized solids used for H{sub 2}S removal from hot gas were oxidized in a Cahn electrobalance and in a fixed bed reactor. The main reactions included the sequence in which FeS was oxidized to iron sulphate which then decomposed rapidly yielding SO{sub 2} and iron oxides. The oxidation occurred predominantly on the outer surface of the pellets. 12 refs., 5 figs., 5 tabs.

  5. Rare bile duct anomaly: B3 duct draining to gallbladder

    Directory of Open Access Journals (Sweden)

    Seung Eun Lee

    2016-01-01

    Full Text Available A 10-year-old girl presented with recurrent right upper abdominal pain and dyspepsia. Magnetic resonance cholangiopancreatography revealed a dilated common channel of intrahepatic bile duct of segment 3 (B3 and segment 4 (B4 drained into the gallbladder directly. The patient underwent laparoscopic cholecystectomy and Roux-en Y hepaticojejunostomy (B3-jejunostomy. Among the anatomical variability of the biliary system, the cholecystohepatic ducts are controversial in existence and incidence. We report a very rare variant of a cholecystohepatic duct in which the B3 duct drained into gallbladder directly and to the best of our knowledge this is the first report.

  6. Particle deposition in ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sippola, Mark Raymond [Univ. of California, Berkeley, CA (United States)

    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 μm 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 the

  7. Curved-Duct

    Directory of Open Access Journals (Sweden)

    Je Hyun Baekt

    2000-01-01

    Full Text Available A numerical study is conducted on the fully-developed laminar flow of an incompressible viscous fluid in a square duct rotating about a perpendicular axis to the axial direction of the duct. At the straight duct, the rotation produces vortices due to the Coriolis force. Generally two vortex cells are formed and the axial velocity distribution is distorted by the effect of this Coriolis force. When a convective force is weak, two counter-rotating vortices are shown with a quasi-parabolic axial velocity profile for weak rotation rates. As the rotation rate increases, the axial velocity on the vertical centreline of the duct begins to flatten and the location of vorticity center is moved near to wall by the effect of the Coriolis force. When the convective inertia force is strong, a double-vortex secondary flow appears in the transverse planes of the duct for weak rotation rates but as the speed of rotation increases the secondary flow is shown to split into an asymmetric configuration of four counter-rotating vortices. If the rotation rates are increased further, the secondary flow restabilizes to a slightly asymmetric double-vortex configuration. Also, a numerical study is conducted on the laminar flow of an incompressible viscous fluid in a 90°-bend square duct that rotates about axis parallel to the axial direction of the inlet. At a 90°-bend square duct, the feature of flow by the effect of a Coriolis force and a centrifugal force, namely a secondary flow by the centrifugal force in the curved region and the Coriolis force in the downstream region, is shown since the centrifugal force in curved region and the Coriolis force in downstream region are dominant respectively.

  8. Bile Duct Cancer (Cholangiocarcinoma)

    Science.gov (United States)

    ... Home > Types of Cancer > Bile Duct Cancer (Cholangiocarcinoma) Bile Duct Cancer (Cholangiocarcinoma) This is Cancer.Net’s Guide to Bile Duct Cancer (Cholangiocarcinoma). Use the menu below to ...

  9. Sanitary hot water; Eau chaude sanitaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Cegibat, the information-recommendation agency of Gaz de France for building engineering professionals, has organized this conference meeting on sanitary hot water to present the solutions proposed by Gaz de France to meet its clients requirements in terms of water quality, comfort, energy conservation and respect of the environment: quantitative aspects of the hot water needs, qualitative aspects, presentation of the Dolce Vita offer for residential buildings, gas water heaters and boilers, combined solar-thermal/natural gas solutions, key-specifications of hot water distribution systems, testimony: implementation of a gas hot water reservoir and two accumulation boilers in an apartment building for young workers. (J.S.)

  10. Developing flow in S-shaped ducts. 2: Circular cross-section duct

    Science.gov (United States)

    Taylor, A. M. K. P.; Whitelaw, J. H.; Yianneskis, M.

    1984-01-01

    Laser-Doppler velocimetry measured the laminar and turbulent streamwise flow in a S-duct. The wall pressure distribution and one component of cross-stream velocity were also obtained for the turbulent flow case. Boundary layers near the duct inlet were about 25 percent of the hydraulic diameter in the laminar flow and varied around the periphery of the pipe between 10 percent and 20 percent in turbulent flow. Pressure-driven secondary flows develop in the first half of the S-duct and are attenuated and reversed in the second half. For both Reynolds numbers there is a region near the outer wall of the second half of the duct where the sign of the radial vorticity results in an enforcement of the secondary flow which was established in the first half of the S-duct. The core flow migrates, for both Reynolds numbers, to the outside wall of the first half and lies towards the inside wall of the second half of the S-duct at the outlet. The thinner inlet boundary layers in the turbulent flow give rise to weaker secondary motion.

  11. Novel process chain for hot metal gas forming of ferritic stainless steel 1.4509

    Science.gov (United States)

    Mosel, André; Lambarri, Jon; Degenkolb, Lars; Reuther, Franz; Hinojo, José Luis; Rößiger, Jörg; Eurich, Egbert; Albert, André; Landgrebe, Dirk; Wenzel, Holger

    2018-05-01

    Exhaust gas components of automobiles are often produced in ferritic stainless steel 1.4509 due to the low thermal expansion coefficient and the low material price. Until now, components of the stainless steel with complex geometries have been produced in series by means of multi-stage hydroforming at room temperature with intermediate annealing operations. The application of a single-stage hot-forming process, also referred to as hot metal gas forming (HMGF), offers great potential to significantly reduce the production costs of such components. The article describes a novel process chain for the HMGF process. Therefore the tube is heated in two steps. After pre-heating of the semi-finished product outside the press, the tube is heated up to forming start temperature by means of a tool-integrated conductive heating before forming. For the tube of a demonstrator geometry, a simulation model for the conduction heating was set up. In addition to the tool development for this process, experimental results are also described for the production of the demonstrator geometry.

  12. Integrated biomass gasification using the waste heat from hot slags: Control of syngas and polluting gas releases

    International Nuclear Information System (INIS)

    Sun, Yongqi; Seetharaman, Seshadri; Liu, Qianyi; Zhang, Zuotai; Liu, Lili; Wang, Xidong

    2016-01-01

    In this study, the thermodynamics of a novel strategy, i.e., biomass/CO 2 gasification integrated with heat recovery from hot slags in the steel industry, were systemically investigated. Both the target syngas yield and the polluting gas release were considered where the effect of gasifying conditions including temperature, pressure and CO 2 reacted was analyzed and then the roles of hot slags were further clarified. The results indicated that there existed an optimum temperature for the maximization of H 2 production. Compared to blast furnace slags, steel slags remarkably increased the CO yield at 600–1400 °C due to the existence of iron oxides and decreased the S-containing gas releases at 400–700 °C, indicating potential desulfurizing ability. The identification of biomass/CO 2 gasification thermodynamics in presence of slags could thus provide important clues not only for the deep understanding of biomass gasification but also for the industrial application of this emerging strategy from the viewpoint of syngas optimization and pollution control. - Highlights: • Biomass/CO 2 gasification was integrated with the heat recovery from hot slags. • Both syngas yield and polluting gas release during gasification were determined. • There existed an optimum temperature for the maximization of H 2 production. • Steel slags increased CO yield at 600–1400 °C due to the existence of iron oxides. • Steel slags remarkably decreased the releases of S-containing gas at 400–700 °C.

  13. Cool infalling gas and its interaction with the hot ISM of elliptical galaxies

    Science.gov (United States)

    Sparks, W. B.; Macchetto, F. D.

    1990-01-01

    The authors describe work leading to the suggestion that interaction between infalling cool gas and ambient hot, coronal plasma in elliptical galaxies is responsible for emission filaments, and might remove the need for large mass depositions in cooling flows. A test of the hypothesis is undertaken - the run of surface brightness with radius for the emission lines - and the prediction agrees well with the data.

  14. Carbon Formation and Metal Dusting in Hot-Gas Cleanup Systems of Coal Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, Peter F.; Judkins, Roddie R.; DeVan, Jackson H.; Wright, Ian G.

    1995-12-31

    There are several possible materials/systems degradation modes that result from gasification environments with appreciable carbon activities. These processes, which are not necessarily mutually exclusive, include carbon deposition, carburization, metal dusting, and CO disintegration of refractories. Carbon formation on solid surfaces occurs by deposition from gases in which the carbon activity (a sub C) exceeds unity. The presence of a carbon layer CO can directly affect gasifier performance by restricting gas flow, particularly in the hot gas filter, creating debris (that may be deposited elsewhere in the system or that may cause erosive damage of downstream components), and/or changing the catalytic activity of surfaces.

  15. Local ISM 3D Distribution and Soft X-ray Background Inferences for Nearby Hot Gas

    Science.gov (United States)

    Puspitarini, L.; Lallement, R.; Snowden, Steven L.; Vergely, J.-L.; Snowden, S.

    2014-01-01

    Three-dimensional (3D) interstellar medium (ISM) maps can be used to locate not only interstellar (IS) clouds, but also IS bubbles between the clouds that are blown by stellar winds and supernovae, and are filled by hot gas. To demonstrate this, and to derive a clearer picture of the local ISM, we compare our recent 3D IS dust distribution maps to the ROSAT diffuse Xray background maps after removal of heliospheric emission. In the Galactic plane, there is a good correspondence between the locations and extents of the mapped nearby cavities and the soft (0.25 keV) background emission distribution, showing that most of these nearby cavities contribute to this soft X-ray emission. Assuming a constant dust to gas ratio and homogeneous 106 K hot gas filling the cavities, we modeled in a simple way the 0.25 keV surface brightness along the Galactic plane as seen from the Sun, taking into account the absorption by the mapped clouds. The data-model comparison favors the existence of hot gas in the solar neighborhood, the so-called Local Bubble (LB). The inferred mean pressure in the local cavities is found to be approx.9,400/cu cm K, in agreement with previous studies, providing a validation test for the method. On the other hand, the model overestimates the emission from the huge cavities located in the third quadrant. Using CaII absorption data, we show that the dust to CaII ratio is very small in those regions, implying the presence of a large quantity of lower temperature (non-X-ray emitting) ionized gas and as a consequence a reduction of the volume filled by hot gas, explaining at least part of the discrepancy. In the meridian plane, the two main brightness enhancements coincide well with the LB's most elongated parts and chimneys connecting the LB to the halo, but no particular nearby cavity is found towards the enhancement in the direction of the bright North Polar Spur (NPS) at high latitude. We searched in the 3D maps for the source regions of the higher energy

  16. The Effect of Turbulences Flow on a Gas-Liquid Mixing Process Downstream of a Curved Duct

    Directory of Open Access Journals (Sweden)

    Abdul Satar Jawad Mohammed

    2018-02-01

    Full Text Available An experimental investigation is carried out on the use of water injection on the humidification process of air with a steady flow that travels during the curved part of a duct with a constant cross section. The naturally generated turbulences will surely aid the mixing process between the injected water droplets and the air to enhance both the mass and heat transfer. The current investigation is regarded as a simulation of the inlet air cooling of the gas turbine which aims to specify the optimum atomizer position on the air cooling by the fogging technique. The experiments were carried out on a (50×50 cm wind tunnel with an average air velocity of (10 m/s. Experiments were conducted in a range of air to water flow ratio between 1000 and 2000, and an ambient temperature in a range of 30° to 50°C. At higher ambient temperature of 45.2oC (DBT, a temperature reduction of 26% and an increase in the relative humidity ratio of 2.13 were recorded at the flow ratio of 1000. Injecting water upward through the range of angles -25° to 75° showed less sensitivity to atomizer location regardless the radial position of the atomizer. This situation is most suitable for using atomizing array across the duct. The central location with tangential spray introduces the critical position for a single-point spray. Such position is promising the optimum atomizer place specified by a radii ratio of (r/rin=3 and tangential orientation to the direction of flow.

  17. Continuous distillation of bituminous shale. [hot gas in chamber and chamber heated externally

    Energy Technology Data Exchange (ETDEWEB)

    1921-04-27

    A process of continuous distillation of bituminous shale is given in which the heat necessary is produced not only on the exterior but also in the interior of the distillation apparatus in the form of hot gas directly bathing the shale. The residual carbon in the shale after distillation, or maybe with other fuel added to it, can be utilized; the fuel may be utilized not only for the heat it furnishes but also for the gas it gives and which adds itself to the incondensable gas from the distillation. The temperature of the zone of distillation of the shale is regulated by the quantity of gas, the temperature of this gas (which can be lowered voluntarily by injecting into the air a certain quantity of water vapor), the length of the zone comprised between the zone of gasification and distillation; the injection of water vapor permits the recovery of part of the nitrogen of the shale in the form of ammonia; the materials are withdrawn continuously in a mechanical way.

  18. Conversion of hot coke oven gas into light fuel gas over Ni/Al{sub 2}O{sub 3} catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Li, L.Y.; Morishita, K.; Takarada, T. [Gunma University, Gunma (Japan). Dept. of Biology & Chemical Engineering

    2006-04-15

    Conversion of hot coke oven gas (COG, containing tarry material) into light fuel gas over a Ni/Al{sub 2}O{sub 3} catalyst was studied. Laboratory scale tests were carried out in a two-stage fixed-bed reactor at ambient pressure. The nickel catalyst promoted the hydropyrolysis reaction of tarry materials. High yields of total product gas and methane were obtained at high hydrogen concentrations. If the hydrogen supply was adequate for hydropyrolysis of the tarry material, conversion of coal volatiles was high, at more than 95% on carbon balance, even with a gas residence time as short as 0.15 s in the catalyst bed. The product gas yield depended on catalytic temperature. At 923 K, the maximum conversion of coal volatiles into the light gas was achieved at 95.0% on carbon balance, with methane 86.7 vol% of the carbonaceous gas product. Although carbon deposits deactivated the catalyst after a long period of use, the catalyst could be regenerated by treatment with oxygen at 800 K, providing high activity in subsequent decomposition of tarry material. The influence of sulphide on the tarry material decomposition reaction was small even in a 2000 ppm H{sub 2}S atmosphere.

  19. Erosion of graphite surface exposed to hot supersonic hydrogen gas

    Science.gov (United States)

    Sharma, O. P.

    1972-01-01

    A theoretical model based on laminar boundary layer flow equations was developed to predict the erosion rate of a graphite (AGCarb-101) surface exposed to a hot supersonic stream of hydrogen gas. The supersonic flow in the nozzle outside the boundary layer formed over the surface of the specimen was determined by assuming one-dimensional isentropic conditions. An overall surface reaction rate expression based on experimental studies was used to describe the interaction of hydrogen with graphite. A satisfactory agreement was found between the results of the computation, and the available experimental data. Some shortcomings of the model and further possible improvements are discussed.

  20. Residual life assessment of the SSME/ATD HPOTP turnaround duct (TAD)

    Science.gov (United States)

    Gross, R. Steven

    1996-01-01

    This paper is concerned with the prediction of the low cycle thermal fatigue behavior of a component in a developmental (ATD) high pressure liquid oxygen turbopump (HPOTP) for the Space Shuttle Main Engine (SSME). This component is called the Turnaround Duct (TAD). The TAD is a complex single piece casting of MAR-M-247 material. Its function is to turn the hot turbine exhaust gas (1200 F hydrogen rich gas steam) such that it can exhaust radially out of the turbopump. In very simple terms, the TAD consists of two rings connected axially by 22 hollow airfoil shaped struts with the turning vanes placed at the top, middle, and bottom of each strut. The TAD is attached to the other components of the pump via bolts passing through 14 of the 22 struts. Of the remaining 8 struts, four are equally spaced (90 deg interval) and containing a cooling tube through which liquid hydrogen passes on its way to cool the shaft bearing assemblies. The remaining 4 struts are empty. One of the pump units in the certification test series was destructively examined after 22 test firings. Substantial axial cracking was found in two of the struts which contain cooling tubes. None of the other 20 struts showed any sign of internal cracking. This unusual low cycle thermal fatigue behavior within the two cooling tube struts is the focus of this study.

  1. High accuracy acoustic relative humidity measurement in duct flow with air

    NARCIS (Netherlands)

    Schaik, van W.; Grooten, M.H.M.; Wernaart, T.; Geld, van der C.W.M.

    2010-01-01

    An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and

  2. The impact of feedback and the hot halo on the rates of gas accretion onto galaxies

    Science.gov (United States)

    Correa, Camila A.; Schaye, Joop; van de Voort, Freeke; Duffy, Alan R.; Wyithe, J. Stuart B.

    2018-04-01

    We investigate the physics that drives the gas accretion rates onto galaxies at the centers of dark matter haloes using the EAGLE suite of hydrodynamical cosmological simulations. We find that at redshifts z ≤ 2 the accretion rate onto the galaxy increases with halo mass in the halo mass range 1010 - 1011.7 M⊙, flattens between the halo masses 1011.7 - 1012.7 M⊙, and increases again for higher-mass haloes. However, the galaxy gas accretion does not flatten at intermediate halo masses when AGN feedback is switched off. To better understand these trends, we develop a physically motivated semi-analytic model of galaxy gas accretion. We show that the flattening is produced by the rate of gas cooling from the hot halo. The ratio of the cooling radius and the virial radius does not decrease continuously with increasing halo mass as generally thought. While it decreases up to ˜1013 M⊙ haloes, it increases for higher halo masses, causing an upturn in the galaxy gas accretion rate. This may indicate that in high-mass haloes AGN feedback is not sufficiently efficient. When there is no AGN feedback, the density of the hot halo is higher, the ratio of the cooling and virial radii does not decrease as much and the cooling rate is higher. Changes in the efficiency of stellar feedback can also increase or decrease the accretion rates onto galaxies. The trends can plausibly be explained by the re-accretion of gas ejected by progenitor galaxies and by the suppression of black hole growth, and hence AGN feedback, by stellar feedback.

  3. Chemical hot gas purification for biomass gasification processes; Chemische Heissgasreinigung bei Biomassevergasungsprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Stemmler, Michael

    2010-07-01

    The German government decided to increase the percentage of renewable energy up to 20 % of all energy consumed in 2020. The development of biomass gasification technology is advanced compared to most of the other technologies for producing renewable energy. So the overall efficiency of biomass gasification processes (IGCC) already increased to values above 50 %. Therefore, the production of renewable energy attaches great importance to the thermochemical biomass conversion. The feedstock for biomass gasification covers biomasses such as wood, straw and further energy plants. The detrimental trace elements released during gasification of these biomasses, e.g. KCl, H{sub 2}S and HCl, cause corrosion and harm downstream devices. Therefore, gas cleaning poses an especial challenge. In order to improve the overall efficiency this thesis aims at the development of gas cleaning concepts for the allothermic, water blown gasification at 800 C and 1 bar (Guessing-Process) as well as for the autothermic, water and oxygen blown gasification at 950 C and 18 bar (Vaernamo-Process). Although several mechanisms for KCl- and H{sub 2}S-sorption are already well known, the achievable reduction of the contamination concentration is still unknown. Therefore, calculations on the produced syngas and the chemical hot gas cleaning were done with a thermodynamic process model using SimuSage. The syngas production was included in the calculations because the knowledge of the biomass syngas composition is very limited. The results of these calculations prove the dependence of syngas composition on H{sub 2}/C-ratio and ROC (Relative Oxygen Content). Following the achievable sorption limits were detected via experiments. The KCl containing syngases were analysed by molecular beam mass spectrometry (MBMS). Furthermore, an optimised H{sub 2}S-sorbent was developed because the examined sorbents exceeded the sorption limit of 1 ppmv. The calculated sorption limits were compared to the limits

  4. Development of non-duct IH (induction heating) smokeless roaster; Nonduct IH (denjiha yudo kanetsu) muen roaster no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Matsunaga, K. [Chubu Electric Power Co. Inc., Nagoya (Japan)

    1996-11-01

    As a part of diffusion and promotion of electric cooking apparatuses, a non-duct IH smokeless roaster has been developed for roast meat restaurants in cooperation with Hitachi Home Tech. Smoke and odor in the room can be removed without using exhaust duct by incorporating smoke and odor processing equipment into the main body. For the developed roaster, IH was adopted as a heat source with less smoke and exhaust gas compared with city gas. Generated smoke and odor are removed by the electrical precipitator and the deodorant catalyst incorporated in the main body. After the treatment, exhaust gas is emitted in the room. This roaster has characteristics as follows. This roaster can be used at high-class roast meat restaurants for avoiding smoke and odor, and can be brought in banqueting hall of hotels. Since it does not have a duct, there is no danger of fire. It is easy to change the layout of guest room. Since the IH system has less exhaust heat than the gas system, increase in room temperature is moderate, which results in the reduction of air conditioning load. 8 figs., 3 tabs.

  5. Propagation of sound waves in ducts

    DEFF Research Database (Denmark)

    Jacobsen, Finn

    2000-01-01

    Plane wave propagation in ducts with rigid walls, radiation from ducts, classical four-pole theory for composite duct systems, and three-dimentional waves in wave guides of various cross-sectional shape are described.......Plane wave propagation in ducts with rigid walls, radiation from ducts, classical four-pole theory for composite duct systems, and three-dimentional waves in wave guides of various cross-sectional shape are described....

  6. Duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma.

    Science.gov (United States)

    Wu, Wen-Guang; Gu, Jun; Dong, Ping; Lu, Jian-Hua; Li, Mao-Lan; Wu, Xiang-Song; Yang, Jia-Hua; Zhang, Lin; Ding, Qi-Chen; Weng, Hao; Ding, Qian; Liu, Ying-Bin

    2013-04-21

    At present, radical resection remains the only effective treatment for patients with hilar cholangiocarcinoma. The surgical approach for R0 resection of hilar cholangiocarcinoma is complex and diverse, but for the biliary reconstruction after resection, almost all surgeons use Roux-en-Y hepaticojejunostomy. A viable alternative to Roux-en-Y reconstruction after radical resection of hilar cholangiocarcinoma has not yet been proposed. We report a case of performing duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma. End-to-end anastomosis between the left hepatic duct and the distal common bile duct was used for the biliary reconstruction, and a single-layer continuous suture was performed along the bile duct using 5-0 prolene. The patient was discharged favorably without biliary fistula 2 wk later. Evidence for tumor recurrence was not found after an 18 mo follow-up. Performing bile duct end-to-end anastomosis in hilar cholangiocarcinoma can simplify the complex digestive tract reconstruction process.

  7. Physics basis and mechanical design of the actively cooled duct scraper protection for the JET neutral beam enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, D.J. [UKAEA Fusion/Euratom Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)], E-mail: dwilson@jet.uk; Ciric, D.; Cox, S.J.; Jones, T.T.C.; Kovari, M. [UKAEA Fusion/Euratom Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Li Puma, A. [Association EURATOM-CEA, CEA-Cadarache, 13108 St. Paul-Lez-Durance (France); Martin, D.; Milnes, J.; Shannon, M.; Surrey, E. [UKAEA Fusion/Euratom Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

    2007-10-15

    The objectives of the JET neutral beam enhancement (NBE) include raising the delivered power from the present 25 MW to more than 34 MW and increasing the pulse length from 10 to 20 s. The additional power will be obtained partly by increasing the fractional energy components of the beam, resulting from acceleration of molecular ions, hence increasing the total particle flux. These changes place extreme demands on the design of the upgraded protection to the torus entry duct. The present inertial duct protection already reaches its thermomechanical limit in 10 s pulses, and active cooling of the upgraded duct protection is therefore essential. Extensive analysis of the pressure and temperature evolution in the present un-cooled duct established the relationship between gas re-emission and surface temperature for copper in this operating environment. This information was used in an integrated physics and engineering approach to the design of the actively cooled duct protection, taking into account the power loads from direct beam interception and re-ionisation. Surface temperature determines power density through the gas re-emission and consequential beam re-ionisation. These considerations define the normal operating point for the chosen enhanced hypervapotron element technology. This approach demonstrated that supplementary in situ duct cryopumping would not be needed, provided that the required heat-transfer performance could be met without any encroachment of the elements beyond the space envelope of the existing inertial duct protection plates. This requirement posed severe constraints on the mechanical design of the hypervapotron element array and its manifolding; the adopted engineering design solutions are presented.

  8. Bulk and shear viscosities of hot and dense hadron gas

    International Nuclear Information System (INIS)

    Kadam, Guru Prakash; Mishra, Hiranmaya

    2015-01-01

    We estimate the bulk and the shear viscosity at finite temperature and baryon densities of hadronic matter within a hadron resonance gas model which includes a Hagedorn spectrum. The parameters of the Hagedorn spectrum are adjusted to fit recent lattice QCD simulations at finite chemical potential. For the estimation of the bulk viscosity we use low energy theorems of QCD for the energy momentum tensor correlators. For the shear viscosity coefficient, we estimate the same using molecular kinetic theory to relate the shear viscosity coefficient to average momentum of the hadrons in the hot and dense hadron gas. The bulk viscosity to entropy ratio increases with chemical potential and is related to the reduction of velocity of sound at nonzero chemical potential. The shear viscosity to entropy ratio on the other hand, shows a nontrivial behavior with the ratio decreasing with chemical potential for small temperatures but increasing with chemical potential at high temperatures and is related to decrease of entropy density with chemical potential at high temperature due to finite volume of the hadrons

  9. Influence of heat exchange of reservoir with rocks on hot gas injection via a single well

    Science.gov (United States)

    Nikolaev, Vladimir E.; Ivanov, Gavril I.

    2017-11-01

    In the computational experiment the influence of heat exchange through top and bottom of the gas-bearing reservoir on the dynamics of temperature and pressure fields during hot gas injection via a single well is investigated. The experiment was carried out within the framework of modified mathematical model of non-isothermal real gas filtration, obtained from the energy and mass conservation laws and the Darcy law. The physical and caloric equations of state together with the Newton-Riemann law of heat exchange of gas reservoir with surrounding rocks, are used as closing relations. It is shown that the influence of the heat exchange with environment on temperature field of the gas-bearing reservoir is localized in a narrow zone near its top and bottom, though the size of this zone is increased with time.

  10. Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas

    International Nuclear Information System (INIS)

    Zhang, F.M.; Liu, B.S.; Zhang, Y.; Guo, Y.H.; Wan, Z.Y.; Subhan, Fazle

    2012-01-01

    Highlights: ► A series of mesoporous Cu x Mn y O z /SBA-15 sorbents were fabricated for hot coal gas desulfurization. ► 1Cu9Mn/SBA-15 sorbent with high breakthrough sulfur capacity is high stable and regenerable. ► Utilization of SBA-15 constrained the sintering and pulverization of sorbents. - Abstract: A series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700–850 °C. The successive nine desulfurization–regeneration cycles at 800 °C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn 2 O 3 particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800 °C is 13.8 g S/100 g sorbents, which is remarkably higher than these of 40 wt%LaFeO 3 /SBA-15 (4.8 g S/100 g sorbents) and 50 wt%LaFe 2 O x /MCM-41 (5.58 g S/100 g sorbents) used only at 500–550 °C. This suggested that the loading of Mn 2 O 3 active species with high thermal stability to SBA-15 support significantly increased sulfur capacity at relatively higher sulfidation temperature. The fresh and used xCuyMn/SBA-15 sorbents were characterized by means of BET, XRD, XPS, XAES, TG/DSC and HRTEM techniques, confirmed that the structure of the sorbents remained intact before and after hot coal gas desulfurization.

  11. Reciprocity principle in duct acoustics

    Science.gov (United States)

    Cho, Y.-C.

    1979-01-01

    Various reciprocity relations in duct acoustics have been derived on the basis of the spatial reciprocity principle implied in Green's functions for linear waves. The derivation includes the reciprocity relations between mode conversion coefficients for reflection and transmission in nonuniform ducts, and the relation between the radiation of a mode from an arbitrarily terminated duct and the absorption of an externally incident plane wave by the duct. Such relations are well defined as long as the systems remain linear, regardless of acoustic properties of duct nonuniformities which cause the mode conversions.

  12. Heat Transfer Augmentation in Gas Turbine Blade Rectangular Passages Using Circular Ribs with Fins

    Directory of Open Access Journals (Sweden)

    Mohammed W. Al-Jibory

    2017-11-01

    Full Text Available In this paper, an experimental system  was designed and built to simulate conditions in the gas turbine blade cooling and run the experimental part. Boundary conditions are: inlet coolant air temperature is 300K with Reynolds numbers (Re=7901 .The surrounding constant hot air temperatures was (673 K.The numerical simulations were done by using software FLUENT version (14.5, in this part, it was presented the effect of using circular ribs having middle fin fitted in rectangular passage channel on fluid flow and heat transfer characteristics.  Ribs used with pitch-rib height of 10, rectangular channel of (30x60 mm cross section, 1.5 mm duct thickness and 0.5 m long. The temperature, velocity distribution contours, cooling air temperature distribution at the duct centerline, the inner wall surface temperature of the duct, and thermal performance factor are presented in this paper. it can be seen that the duct with all ribs with middle fins was the better case which leads to increase the coolant air temperature by (10.22 % and decrease the inner wall temperature by (6.15 % . The coolant air flow velocity seems to be accelerated and decelerated through the channel in the presence of ribs, so it was shown that the thermal performance factor along the duct is larger than 1, this is due to the fact that the ribs create turbulent conditions and increasing thermal surface area, and thus increasing heat transfer coefficient than the smooth channel.

  13. Solid adsorbents for removal of hydrogen sulphide from hot gas

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Yumura, Motoo

    1986-04-01

    A wide range of solids have been tested as potential adsorbents for H/sub 2/S removal from hot gas. These solids can be divided into two main groups, i.e., the adsorbents containing alkaline earth metals and those containing transition metals. Among the former, calcium oxide and naturally occurring materials such as limestone, dolomite and calcium silicate have attracted a great deal of attention. The adsorbents of the second group include iron oxide alone or in combination with some supports, zinc oxide, zinc ferrite and manganese oxide. The materials containing both the alkaline earth metals and transition metals, e.g., manganese nodules, fly ash and the reject from the aluminium industry (red mud) have been evaluated as well.

  14. Hot Surface Ignition

    OpenAIRE

    Tursyn, Yerbatyr; Goyal, Vikrant; Benhidjeb-Carayon, Alicia; Simmons, Richard; Meyer, Scott; Gore, Jay P.

    2015-01-01

    Undesirable hot surface ignition of flammable liquids is one of the hazards in ground and air transportation vehicles, which primarily occurs in the engine compartment. In order to evaluate the safety and sustainability of candidate replacement fuels with respect to hot surface ignition, a baseline low lead fuel (Avgas 100 LL) and four experimental unleaded aviation fuels recommended for reciprocating aviation engines were considered. In addition, hot surface ignition properties of the gas tu...

  15. Process simulation and experimental validation of Hot Metal Gas Forming with new press hardening steels

    Science.gov (United States)

    Paul, A.; Reuther, F.; Neumann, S.; Albert, A.; Landgrebe, D.

    2017-09-01

    One field in the work of the Fraunhofer Institute for Machine Tools and Forming Technology IWU in Chemnitz is industry applied research in Hot Metal Gas Forming, combined with press hardening in one process step. In this paper the results of investigations on new press hardening steels from SSAB AB (Docol®1800 Bor and Docol®2000 Bor) are presented. Hot tensile tests recorded by the project partner (University of West Bohemia, Faculty of Mechanical Engineering) were used to create a material model for thermo-mechanical forming simulations. For this purpose the provided raw data were converted into flow curve approximations of the real stress-real strain-curves for both materials and afterwards integrated in a LS-DYNA simulation model of Hot Metal Gas Forming with all relevant boundary conditions and sub-stages. Preliminary experimental tests were carried out using a tool at room temperature to permit evaluation of the forming behaviour of Docol 1800 Bor and Docol 2000 Bor tubes as well as validation of the simulation model. Using this demonstrator geometry (outer diameter 57 mm, tube length 300 mm, wall thickness 1.5 mm), the intention was to perform a series of tests with different furnace temperatures (from 870 °C to 1035 °C), maximum internal pressures (up to 67 MPa) and pressure build-up rates (up to 40 MPa/s) to evaluate the formability of Docol 1800 Bor and Docol 2000 Bor. Selected demonstrator parts produced in that way were subsequently analysed by wall thickness and hardness measurements. The tests were carried out using the completely modernized Dunkes/AP&T HS3-1500 hydroforming press at the Fraunhofer IWU. In summary, creating a consistent simulation model with all relevant sub-stages was successfully established in LS-DYNA. The computation results show a high correlation with the experimental data regarding the thinning behaviour. The Hot Metal Gas Forming of the demonstrator geometry was successfully established as well. Different hardness values

  16. Isospin and momentum dependence of liquid-gas phase transition in hot asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Xu, Jun; Ma, Hongru; Chen, Liewen; Li, Baoan

    2008-01-01

    The liquid-gas phase transition in hot neutron-rich nuclear matter is investigated within a self-consistent thermal model using different interactions with or without isospin and/or momentum dependence. The boundary of the phase-coexistence region is shown to be sensitive to the density dependence of the nuclear symmetry energy as well as the isospin and momentum dependence of the nuclear interaction. (author)

  17. Reference values of MRI measurements of the common bile duct and pancreatic duct in children

    Energy Technology Data Exchange (ETDEWEB)

    Gwal, Kriti; Bedoya, Maria A.; Patel, Neal; Darge, Kassa; Anupindi, Sudha A. [University of Pennsylvania Perelman School of Medicine, Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Rambhatla, Siri J. [Beth Israel Medical Center, Department of Pediatrics, Newark, NJ (United States); Sreedharan, Ram R. [University of Pennsylvania, Departments of Gastroenterology, Hepatology and Nutrition, The Children' s Hospital of Philadelphia, Perelman School of Medicine, Philadelphia, PA (United States)

    2015-08-15

    Magnetic resonance imaging/cholangiopancreatography (MRI/MRCP) is now an essential imaging modality for the evaluation of biliary and pancreatic pathology in children, but there are no data depicting the normal diameters of the common bile duct (CBD) and pancreatic duct. Recognition of abnormal duct size is important and the increasing use of MRCP necessitates normal MRI measurements. To present normal MRI measurements for the common bile duct and pancreatic duct in children. In this retrospective study we searched all children ages birth to 10 years in our MR urography (MRU) database from 2006 until 2013. We excluded children with a history of hepatobiliary or pancreatic surgery. We stratified 204 children into five age groups and retrospectively measured the CBD and the pancreatic duct on 2-D axial and 3-D coronal T2-weighted sequences. We performed statistical analysis, using logistic and linear regressions to detect the age association of the visibility and size of the duct measurements. We used non-parametric tests to detect gender and imaging plane differences. Our study included 204 children, 106 (52%) boys and 98 (48%) girls, with a median age of 33 months (range 0-119 months). The children were distributed into five age groups. The common bile duct was visible in all children in all age groups. The pancreatic duct was significantly less visible in the youngest children, group 1 (54/67, 80.5%; P = 0.003) than in the oldest children, group 5 (22/22, 100%). In group 2 the pancreatic duct was seen in 19/21 (90.4%), in group 3 52/55 (94.5%), and in group 4 39/39 (100%). All duct measurements increased with age (P < 0.001; r-value > 0.423), and the incremental differences between ages were significant. The measurement variations between the axial and coronal planes were statistically significant (P < 0.001); however these differences were fractions of millimeters. For example, in group 1 the mean coronal measurement of the CBD was 2.1 mm and the axial

  18. Reference values of MRI measurements of the common bile duct and pancreatic duct in children

    International Nuclear Information System (INIS)

    Gwal, Kriti; Bedoya, Maria A.; Patel, Neal; Darge, Kassa; Anupindi, Sudha A.; Rambhatla, Siri J.; Sreedharan, Ram R.

    2015-01-01

    Magnetic resonance imaging/cholangiopancreatography (MRI/MRCP) is now an essential imaging modality for the evaluation of biliary and pancreatic pathology in children, but there are no data depicting the normal diameters of the common bile duct (CBD) and pancreatic duct. Recognition of abnormal duct size is important and the increasing use of MRCP necessitates normal MRI measurements. To present normal MRI measurements for the common bile duct and pancreatic duct in children. In this retrospective study we searched all children ages birth to 10 years in our MR urography (MRU) database from 2006 until 2013. We excluded children with a history of hepatobiliary or pancreatic surgery. We stratified 204 children into five age groups and retrospectively measured the CBD and the pancreatic duct on 2-D axial and 3-D coronal T2-weighted sequences. We performed statistical analysis, using logistic and linear regressions to detect the age association of the visibility and size of the duct measurements. We used non-parametric tests to detect gender and imaging plane differences. Our study included 204 children, 106 (52%) boys and 98 (48%) girls, with a median age of 33 months (range 0-119 months). The children were distributed into five age groups. The common bile duct was visible in all children in all age groups. The pancreatic duct was significantly less visible in the youngest children, group 1 (54/67, 80.5%; P = 0.003) than in the oldest children, group 5 (22/22, 100%). In group 2 the pancreatic duct was seen in 19/21 (90.4%), in group 3 52/55 (94.5%), and in group 4 39/39 (100%). All duct measurements increased with age (P < 0.001; r-value > 0.423), and the incremental differences between ages were significant. The measurement variations between the axial and coronal planes were statistically significant (P < 0.001); however these differences were fractions of millimeters. For example, in group 1 the mean coronal measurement of the CBD was 2.1 mm and the axial

  19. Bile duct stricture

    Science.gov (United States)

    ... duct, the tube that moves bile from the liver to the small intestine. Bile is a substance that helps with digestion. ... causes of this condition include: Cancer of the bile duct, liver or pancreas Damage and scarring due to a ...

  20. Blocked Tear Duct

    Science.gov (United States)

    ... of the nose (lacrimal sac). From there tears travel down a duct (the nasolacrimal duct) draining into your nose. Once in the nose, tears are reabsorbed. A blockage can occur at any point in the tear drainage system, from the puncta ...

  1. Hot gas path component having cast-in features for near wall cooling

    Science.gov (United States)

    Miranda, Carlos Miguel; Kottilingam, Srikanth Chandrudu; Lacy, Benjamin Paul

    2018-04-10

    A hot gas path component includes a substrate having an outer surface and an inner surface. The inner surface of the substrate defines at least one interior space. At least a portion of the outer surface of the substrate includes a recess formed therein. The recess includes a bottom surface and a groove extending at least partially along the bottom surface of the recess. A cover is disposed within the recess and covers at least a portion of the groove. The groove is configured to channel a cooling fluid therethrough to cool the cover.

  2. Graphite and carbon/carbon components for hot gas ducts

    International Nuclear Information System (INIS)

    Popp, G.; Gruber, U.; Boeder, H.; Janssen, K.

    1984-01-01

    The large coal reserves in the Federal Republic of Germany and the uncertainty of the future energy situation on the world market make it appear sound policy to devote some thought to the gasification of coal. For certain chemical processes, moreover, it would be advantageous to have a reasonably priced source of process heat available. In the Federal Republic of Germany this process heat shall be produced in a high-temperature nuclear reactor (HTR), the primary heating temperatures being in the range between 950 deg. C and 1050 deg. C. One serious problem in utilisation of high temperature heat is the resistance of the construction materials. Ceramic materials with high temperature resistance are considered. The material includes graphite and CC carbon fibre reinforced carbon. As a result of the project promoted by Ministerium fur Wirtschaft (Federal Republic of Germany) it has been demonstrated that both CC and graphite manufactured by SIGRI GmbH are well suited for use in high temperature reactors

  3. Hot gas path component cooling system having a particle collection chamber

    Science.gov (United States)

    Miranda, Carlos Miguel; Lacy, Benjamin Paul

    2018-02-20

    A cooling system for a hot gas path component includes a substrate having an outer surface and an inner surface. The inner surface defines at least one interior space. A passage is formed in the substrate between the outer surface and the inner surface. An access passage is formed in the substrate and extends from the outer surface to the inner space. The access passage is formed at a first acute angle to the passage and includes a particle collection chamber. The access passage is configured to channel a cooling fluid to the passage. Furthermore, the passage is configured to channel the cooling fluid therethrough to cool the substrate.

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

    Science.gov (United States)

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

    1992-01-01

    . The present study compares results for both the Baldwin-Lomas and k-epsilon turbulence models and is conducted with a refined grid. For the transition duct, two inlet conditions were considered, the first with straight flow and the second with swirling flow. The first case permits examination of the effects of the geometric transition on the flow field, while the second case includes the rotational flow effect characteristic of a gas turbine engine.

  5. High temperature corrosion of advanced ceramic materials for hot gas filters. Topical report for part 1 of high temperature corrosion of advanced ceramic materials for hot gas filters and heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Spear, K.E.; Crossland, C.E.; Shelleman, D.L.; Tressler, R.E. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering

    1997-12-11

    This program consists of two separate research areas. Part 1, for which this report is written, studied the high temperature corrosion of advanced ceramic hot gas filters, while Part 2 studied the long-term durability of ceramic heat exchangers to coal combustion environments. The objectives of Part 1 were to select two candidate ceramic filter materials for flow-through hot corrosion studies and subsequent corrosion and mechanical properties characterization. In addition, a thermodynamic database was developed so that thermochemical modeling studies could be performed to simulate operating conditions of laboratory reactors and existing coal combustion power plants, and to predict the reactions of new filter materials with coal combustion environments. The latter would make it possible to gain insight into problems that could develop during actual operation of filters in coal combustion power plants so that potential problems could be addressed before they arise.

  6. Thermal neutrons streaming in straight duct

    International Nuclear Information System (INIS)

    Jehouani, A.; Boulkheir, M.; Ichaoui, R.

    2000-01-01

    The neutron streaming in duct is due to two phenomena: a) direct propagation and b) reflection on duct wall. We have used the Monte Carlo method to evaluate the ratio of the reflected neutrons flux by the duct wall to the total flux at the exit of the duct for iron and aluminium. Ten neutrons energy groups are considered between 10 -5 eV and 10 eV. A Fortran program is developed to evaluate the neutron double differential albedo. It is shown that the two following approximations are largely justified: i) Three collisions in the duct wall are sufficient to attain the asymptotic limit of the multiscattered neutron double differential albedo ii) The points of entry and exit of the neutron in the duct wall may be considered the same for the multiscattered neutrons. For a punctual source at the mouth of the duct, we have determined the direct and the reflected part of the total thermal neutron flux at the exit of the duct for different lengths and different radius of the duct. For a punctual source, we have found that the major contribution to the total flux of neutrons at the exit is due to the neutron reflection by walls and the reflection contribution decreases when the neutron energy decreases. For a constant length of the duct, the reflected part decreases when the duct radius increases while for the disk shaped source we have found the opposite phenomena. The transmitted neutron flux distribution at the exit of the duct are determined for disk shaped source for different neutron energy and for different distance from the exit center. (author)

  7. CFD analysis of gas explosions vented through relief pipes.

    Science.gov (United States)

    Ferrara, G; Di Benedetto, A; Salzano, E; Russo, G

    2006-09-21

    Vent devices for gas and dust explosions are often ducted to safe locations by means of relief pipes. However, the presence of the duct increases the severity of explosion if compared to simply vented vessels (i.e. compared to cases where no duct is present). Besides, the identification of the key phenomena controlling the violence of explosion has not yet been gained. Multidimensional models coupling, mass, momentum and energy conservation equations can be valuable tools for the analysis of such complex explosion phenomena. In this work, gas explosions vented through ducts have been modelled by a two-dimensional (2D) axi-symmetric computational fluid dynamic (CFD) model based on the unsteady Reynolds Averaged Navier Stokes (RANS) approach in which the laminar, flamelet and distributed combustion models have been implemented. Numerical test have been carried out by varying ignition position, duct diameter and length. Results have evidenced that the severity of ducted explosions is mainly driven by the vigorous secondary explosion occurring in the duct (burn-up) rather than by the duct flow resistance or acoustic enhancement. Moreover, it has been found out that the burn-up affects explosion severity due to the reduction of venting rate rather than to the burning rate enhancement through turbulization.

  8. Vitellointestinal Duct Anomalies in Infancy

    OpenAIRE

    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: paten...

  9. The role of the Milky Way hot coronal gas on its dwarf galaxies stellar population

    Science.gov (United States)

    Pasetto, Stefano; Cropper, Mark; fujita, Yutaka; Chiosi, Cesare; Grebel, Eva K.

    2015-08-01

    A large amount (˜5 ×1010 Msun) of hot gas is thought to exist in an extended (˜200 kpc) hot diffuse halo around the Milky Way (MW). We investigate the competitive role of the different dissipative phenomena acting on the onset of star formation history of gravitationally bound system in this external environment. Ram pressure, Kelvin-Helmholtz instability, Rayleigh-Taylor, and tidal forces are accounted separately in an analytical framework and compared in their role in influencing the star forming regions. We present an analytical criterion to elucidate the dependence of star formation in a spherical stellar system on its surrounding environment useful in observational applications as well as theoretical interpretations of numerical results.We consider the different signatures of these phenomena in synthetically realized colour-magnitude diagrams (CMDs) of the orbiting system thus investigating the detectability limits of these different effects for future observational projects and their relevance.The theoretical framework developed has direct applications to the cases of our MW system as well as dwarf galaxies in galaxy clusters or any primordial gas-rich cluster of stars orbiting within its host galaxy.

  10. Effects of atmospheric gas composition and temperature on the gasification of coal in hot briquetting carbon composite iron ore

    Energy Technology Data Exchange (ETDEWEB)

    Ueki, Y.; Kanayama, M.; Maeda, T.; Nishika, K.; Shimizu, M. [Kyushu University, Fukuoka (Japan). Dept. of Materials Science & Engineering

    2007-01-15

    The gasification behavior of carbon composite iron ore produced by hot briquetting process was examined under various gas atmospheres such as CO-N{sub 2}, CO{sub 2}-N, and CO-CO{sub 2} at various temperatures. The gasification of coal was affected strongly by atmospheric gas concentration and reaction temperature. Kinetic analysis in various gas atmospheres was carried out by using the first order reaction model, which yields the straight line relation between reaction rate constants for the gasification of coal and the gas concentration. Therefore, reaction rate constants for the gasification of coal in CO-CO{sub 2}-N{sub 2} gas atmosphere were derived.

  11. Patent arterial duct

    Directory of Open Access Journals (Sweden)

    Martin Robin P

    2009-07-01

    Full Text Available Abstract 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

  12. Using Innovative Technologies for Manufacturing Rocket Engine Hardware

    Science.gov (United States)

    Betts, E. M.; Eddleman, D. E.; Reynolds, D. C.; Hardin, N. A.

    2011-01-01

    Many of the manufacturing techniques that are currently used for rocket engine component production are traditional methods that have been proven through years of experience and historical precedence. As the United States enters into the next space age where new launch vehicles are being designed and propulsion systems are being improved upon, it is sometimes necessary to adopt innovative techniques for manufacturing hardware. With a heavy emphasis on cost reduction and improvements in manufacturing time, rapid manufacturing techniques such as Direct Metal Laser Sintering (DMLS) are being adopted and evaluated for their use on NASA s Space Launch System (SLS) upper stage engine, J-2X, with hopes of employing this technology on a wide variety of future projects. DMLS has the potential to significantly reduce the processing time and cost of engine hardware, while achieving desirable material properties by using a layered powder metal manufacturing process in order to produce complex part geometries. Marshall Space Flight Center (MSFC) has recently hot-fire tested a J-2X gas generator (GG) discharge duct that was manufactured using DMLS. The duct was inspected and proof tested prior to the hot-fire test. Using a workhorse gas generator (WHGG) test fixture at MSFC's East Test Area, the duct was subjected to extreme J-2X hot gas environments during 7 tests for a total of 537 seconds of hot-fire time. The duct underwent extensive post-test evaluation and showed no signs of degradation. DMLS manufacturing has proven to be a viable option for manufacturing rocket engine hardware, and further development and use of this manufacturing method is recommended.

  13. Eversion Bile Duct Anastomosis: A Safe Alternative for Bile Duct Size Discrepancy in Deceased Donor Liver Transplantation.

    Science.gov (United States)

    Leal-Leyte, Pilar; McKenna, Greg J; Ruiz, Richard M; Anthony, Tiffany L; Saracino, Giovanna; Giuliano, Testa; Klintmalm, Goran B; Kim, Peter Tw

    2018-04-10

    Introduction Bile duct size discrepancy in liver transplantation may increase the risk of biliary complications. The aim of this study was to evaluate the safety and outcomes of the eversion bile duct anastomosis technique in deceased donor liver transplantation (DDLT) with duct to duct anastomosis. Methods A total of 210 patients who received a DDLT with duct to duct anastomosis from 2012 to 2017 were divided into two groups: those who had eversion bile duct anastomosis (N=70) and standard bile duct anastomosis (N=140). Biliary complications rates were compared between the two groups. Results There was no difference in the cumulative incidence of biliary strictures (P=0.20) and leaks (P=0.17) between the two groups. The biliary complication rate in the eversion group was 14.3% and 11.4% in the standard anastomosis group. All the biliary complications in the eversion group were managed with endoscopic stenting. A severe size mismatch (≥3:1 ratio) was associated with a significantly higher incidence of biliary strictures (44.4%) compared to 2:1 ratio (8.2%), (P=0.002). Conclusion The use of the eversion technique is a safe alternative for bile duct discrepancy in deceased donor liver transplantation; however, severe bile duct size mismatch may be a risk factor for biliary strictures with such technique. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

  14. Critical analysis of the condensation of water vapor at external surface of the duct

    Science.gov (United States)

    Kumar, Dileep; Memon, Rizwan Ahmed; Memon, Abdul Ghafoor; Ali, Intizar; Junejo, Awais

    2018-01-01

    In this paper, the effects of contraction of the insulation of the air duct of heating, ventilation, and air conditioning (HVAC) system is investigated. The compression of the insulation contracts it at joint, turn and other points of the duct. The energy loss and the condensation resulted from this contraction are also estimated. A mathematical model is developed to simulate the effects of this contraction on the heat gain, supply air temperature and external surface temperature of the duct. The simulation uses preliminary data obtained from an HVAC system installed in a pharmaceutical company while varying the operating conditions. The results reveal that insulation thickness should be kept greater than 30 mm and the volume flow rate of the selected air distribution system should be lower than 1.4m3/s to subside condensation on the external surface of the duct. Additionally, the optimum insulation thickness was determined by considering natural gas as an energy source and fiberglass as an insulation material. The optimum insulation thickness determined for different duct sizes varies from 28 to 45 mm, which is greater than the critical insulation thickness. Therefore, the chances of condensation on the external surface of the duct could be avoided at an optimum insulation thickness. Moreover, the effect of pressure loss coefficient of the duct fitting of air distribution system is estimated. The electricity consumption in air handling unit (AHU) decreases from 2.1 to 1.5 kW by decreasing the pressure loss coefficient from 1.5 to 0.5.

  15. Substation interference on gas entrance of industrial plants

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Paulo Edmundo; Giacommelo, Claudinei [PAIOL Engenharia, Paulinia, SP (Brazil)

    2009-12-19

    Industrial plants often have medium or high voltage electrical power entrance and also gas feeders. Often the main substation is located near the gas entrance, in the utilities area. When the occurrence of a phase to ground short-circuit in the substation, the pipeline and gas entrance that serves the plant may be exposed to high voltage soil potential, of the order of a few kilovolts, due to resistive coupling with the substation ground mesh. The consequences of this situation are reflected in various risks, with emphasis on: damage to the protective coating of the duct, due to the increased soil potential, in excess of its dielectric supportability (typically on the order of 5 kV); spread of potentially hazardous to duct exposed parts (valves, measuring place etc.); and damage to cathodic protection system components, as rectifier and insulating joins at gas entrance. This paper presents the investigations conducted in a factory that has a 69 kV main substation very close to the gas entrance, the order of a few meters away. The substation phase to ground short-circuit current is 7 kA, what causes a 9 kV soil potential near the gas pipe. It is presented the methodology for modeling the various elements involved in this process, the results of simulations made, arrangements been taken to reduce soil potential next to the duct to levels below 5 kV, and the measures for people and insulating joins protection. It is important to note that such problems usually will be solved with measures involving the entire grounding system of the industrial complex and also close to the duct (outside the industrial plant). The gas distribution companies should require from customers where this situation occurs, to ensure safety for people who have access to elements of its network, and for the integrity of their own ducts and cathodic protection components. The computer simulations developed for this work were made with the software Auto Grid, developed by the Canadian company Safe

  16. Pion-pair formation and the pion dispersion relation in a hot pion gas

    Energy Technology Data Exchange (ETDEWEB)

    Chanfay, G. [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; Alm, T. [Rostock Univ. (Germany); Schuck, P. [Grenoble-1 Univ., 38 (France). Inst. des Sciences Nucleaires; Welke, G. [Wayne State Univ., Detroit, MI (United States). Dept. of Physics and Astronomy

    1996-09-01

    The possibility of pion-pair formation in a hot pion gas, based on the bosonic gap equation, is pointed out and discussed in detail. The critical temperature for condensation of pion pairs (Evans-Rashind transition) is determined as a function of the pion density. As for fermions, this phase transition is signaled by the appearance of a pole in the two-particle propagator. In Bose systems there exists a second, lower critical temperature, associated with the appearance of the single-particle condensate. Between the two critical temperatures the pion dispersion relation changes from the usual quasiparticle dispersion to a Bogoliubov-like dispersion relation at low momenta. This generalizes the non-relativistic results for an attractive Bose gas by Evans et al. Possible consequences for the inclusive pion spectra measured in heavy-ion collisions at ultra-relativistic energies are discussed. 21 refs.

  17. Plant accident dynamics of high-temperature reactors with direct gas turbine cycle

    International Nuclear Information System (INIS)

    Waloch, M.L.

    1977-01-01

    In the paper submitted, a one-dimensional accident simulation model for high-temperature reactors with direct-cycle gas turbine (single-cycle facilities) is described. The paper assesses the sudden failure of a gas duct caused by the double-ended break of one out of several parallel pipes before and behind the reactor for a non-integrated plant, leading to major loads in the reactor region, as well as the complete loss of vanes of the compressor for an integrated plant. The results of the calculations show especially high loads for the break of a hot-gas pipe immediately behind the flow restrictors of the reactor outlet, because of prolonged effects of pressure gradients in the reactor region and the maximum core differential pressure. A plant accident dynamics calculation therefore allows to find a compromise between the requirements of stable compressor operation, on the one hand, and small loads in the reactor in the course of an accident, on the other, by establishing in a co-ordinated manner the narrowing ratio of the flow restrictors. (GL) [de

  18. Energy saving type area hot water supply system using heat of hot waste water from the sludge center as hot source for hot water; New energy rokko airando CITY. Surajjisenta karano onhaisuinetsu wo kyuyuyo netsugen ni riyosuru sho energy gata chiiki onsui kyokyu system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    Heat source of area hot water supply system in Rokko island City (man-made island) is heat of combustion at the sludge center (sludge incineration plant) in this island. Dehydrated sludge cakes (230ton/day) brought from seven sewage disposal plants in Kobe City is combusted (850degC) in the fluid bed hearth. Combustion gas washed in the scrubber, hot waste water after the washing give heat into heat transfer water in the first heat exchanger. Temperature being 64degC in summer and about 50degC in winter, this heat transfer water is sent into the second heat exchanger at every condominium building throughout the pipe line system circulating in the area. At each home, gas heater and hot water supply devices fitted, additional combustion is not necessary in summer but is used according to demand in other seasons. This hot water supply service has been carried out since 1988 and at present has been used by 3600 homes. Amount of supplying hot water being about 3000cu.m/day, saving is calculated roughly as 60% of gas for hot water supply. Fee for this system is 1500/yen/month uniformly for each home. 14 figs.

  19. Bile Duct Adenoma with Oncocytic Features

    Directory of Open Access Journals (Sweden)

    E. J. Johannesen

    2014-01-01

    Full Text Available Bile duct adenomas are benign bile duct proliferations usually encountered as an incidental finding. Oncocytic bile duct neoplasms are rare and the majority are malignant. A 61-year-old male with a diagnosis of colorectal adenocarcinoma was undergoing surgery when a small white nodule was discovered on the surface of the right lobe of his liver. This lesion was composed of cytologically bland cells arranged in tightly packed glands. These cells were immunopositive for cytokeratin 7, negative for Hep Par 1, contained mucin, and had a Ki67 proliferation index of 8%. The morphology, immunophenotype, presence of mucin, and normal appearing bile ducts, as well as the increased Ki67 proliferation rate, were consistent with a bile duct adenoma with oxyphilic (oncocytic change. Oncocytic tumors in the liver are rare; the first described in 1992. Only two bile duct adenomas with oncocytic change have been reported and neither of them had reported mucin production or the presence of normal appearing bile ducts within the lesion.

  20. DQO Summary Report for 324 and 327 Building Hot Cells D4 Project Waste Characterization

    Energy Technology Data Exchange (ETDEWEB)

    T.A. Lee

    2006-02-06

    This data quality objective (DQO) summary report provides the results of the DQO process conducted for waste characterization activities for the 324 and 327 Building hot cells decommission, deactivate, decontaminate, and demolish activities. This DQO summary report addresses the systems and processes related to the hot cells, air locks, vaults, tanks, piping, basins, air plenums, air ducts, filters, an adjacent elements that have high dose rates, high contamination levels, and/or suspect transuranic waste, which will require nonstandard D4 techniques.

  1. Catalytic hot gas cleaning of gasification gas

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1997-12-31

    The aim of this work was to study the catalytic cleaning of gasification gas from tars and ammonia. In addition, factors influencing catalytic activity in industrial applications were studied, as well as the effects of different operation conditions and limits. Also the catalytic reactions of tar and ammonia with gasification gas components were studied. The activities of different catalyst materials were measured with laboratory-scale reactors fed by slip streams taken from updraft and fluid bed gasifiers. Carbonate rocks and nickel catalysts proved to be active tar decomposing catalysts. Ammonia decomposition was in turn facilitated by nickel catalysts and iron materials like iron sinter and iron dolomite. Temperatures over 850 deg C were required at 2000{sup -1} space velocity at ambient pressure to achieve almost complete conversions. During catalytic reactions H{sub 2} and CO were formed and H{sub 2}O was consumed in addition to decomposing hydrocarbons and ammonia. Equilibrium gas composition was almost achieved with nickel catalysts at 900 deg C. No deactivation by H{sub 2}S or carbon took place in these conditions. Catalyst blocking by particulates was avoided by using a monolith type of catalyst. The apparent first order kinetic parameters were determined for the most active materials. The activities of dolomite, nickel catalyst and reference materials were measured in different gas atmospheres using laboratory apparatus. This consisted of nitrogen carrier, toluene as tar model compound, ammonia and one of the components H{sub 2}, H{sub 2}O, CO, CO{sub 2}, CO{sub 2}+H{sub 2}O or CO+CO{sub 2}. Also synthetic gasification gas was used. With the dolomite and nickel catalyst the highest toluene decomposition rates were measured with CO{sub 2} and H{sub 2}O. In gasification gas, however, the rate was retarded due to inhibition by reaction products (CO, H{sub 2}, CO{sub 2}). Tar decomposition over dolomite was modelled by benzene reactions with CO{sub 2}, H

  2. Vacuum exhaust duct used for thermonuclear device

    International Nuclear Information System (INIS)

    Tachikawa, Nobuo; Kondo, Mitsuaki; Honda, Tsutomu.

    1990-01-01

    The present invention concerns a vacuum exhaust duct used for a thermonuclear device. A cylindrical metal liners is lined with a gap to the inside of a vacuum exhaust duct main body. Bellows are connected to both ends of the metal liners and the end of the bellows is welded to the vacuum exhaust duct main body. Futher, a heater is mounted to the metal liner on the side of the vacuum exhaust duct main body, and the metal liner is heated by the heater to conduct baking for the vacuum exhaust duct main body. Accordingly, since there is no requirement for elevating the temperature of the vacuum exhaust duct upon conducting baking, the vacuum exhaust duct scarcely suffers substantial deformation due to heat expansion. Further, there is also no substantial deformation for the bellows disposed between the outer circumference of the vacuum vessel and a portion of a vacuum exhaust duct, so that the durability of the bellows is greatly improved. (I.S.)

  3. Quadcopter thrust optimization with ducted-propeller

    Directory of Open Access Journals (Sweden)

    Kuantama Endrowednes

    2017-01-01

    Full Text Available In relation to quadcopter body frame model, propeller can be categorized into propeller with ducted and without ducted. This study present differences between those two using CFD (Computational Fluid Dynamics method. Both categories utilize two blade-propeller with diameter of 406 (mm. Propeller rotation generates acceleration per time unit on the volume of air. Based on the behavior of generated air velocity, ducted propeller can be modeled into three versions. The generated thrust and performance on each model were calculated to determine the best model. The use of ducted propeller increases the total weight of quadcopter and also total thrust. The influence of this modeling were analyzed in detail with variation of angular velocity propeller from 1000 (rpm to 9000 (rpm. Besides the distance between propeller tip and ducted barrier, the size of ducted is also an important part in thrust optimization and total weight minimization of quadcopter.

  4. Safety assessment of a multicavity prestressed concrete reactor vessel with hot liner

    Energy Technology Data Exchange (ETDEWEB)

    Lafitte, R.; Marchand, J. D. [Bonnard et Gardel, Ingenieurs-Conseil, Lausanne (Switzerland)

    1981-01-15

    The prestressed concrete reactor vessel of the high temperature reactor with helium turbine project differs from those realized up to this day by the important number of cavities, by the different cavity pressures and by a liner in contact with hot gas. For the cases of operating conditions, the computations can be based on an identical pressure in all the cavities. The overdimensioning of the vessel which results is not a determining factor at this stage of the project. The possible loss of leaktightness of the liner can introduce gas pressure into the walls of the vessel. The great thickness of the walls makes it impossible to withstand the resulting forces with prestressing in offering sufficient safety factor against collapse. It is thus important to design a drainage network largely dimensioned. The warm liner appears at this stage of the project too highly stressed by fatigue at the singularity points (ducts between cavities, angles). A solution is proposed which limits the variations of thermal stresses by using a steel with low coefficient of thermal expansion. The cavity closures, which are numerous and some with large dimensions are an important aspect of the vessel safety. A solution of reinforced concrete shell with independent liner is proposed.

  5. Safety assessment of a multicavity prestressed concrete reactor vessel with hot liner

    International Nuclear Information System (INIS)

    Lafitte, R.; Marchand, J.D.

    1981-01-01

    The prestressed concrete reactor vessel of the high temperature reactor with helium turbine project differs from those realized up to this day by the important number of cavities, by the different cavity pressures and by a liner in contact with hot gas. For the cases of operating conditions, the computations can be based on an identical pressure in all the cavities. The overdimensioning of the vessel which results is not a determining factor at this stage of the project. The possible loss of leaktightness of the liner can introduce gas pressure into the walls of the vessel. The great thickness of the walls makes it impossible to withstand the resulting forces with prestressing in offering sufficient safety factor against collapse. It is thus important to design a drainage network largely dimensioned. The warm liner appears at this stage of the project too highly stressed by fatigue at the singularity points (ducts between cavities, angles). A solution is proposed which limits the variations of thermal stresses by using a steel with low coefficient of thermal expansion. The cavity closures, which are numerous and some with large dimensions are an important aspect of the vessel safety. A solution of reinforced concrete shell with independent liner is proposed

  6. Vibrational response of a rectangular duct of finite length excited by a turbulent internal flow

    Science.gov (United States)

    David, Antoine; Hugues, Florian; Dauchez, Nicolas; Perrey-Debain, Emmanuel

    2018-05-01

    Gas transport ductwork in industrial plants or air conditioning networks can be subject to vibrations induced by the internal flow. Most studies in this matter have been carried out on circular ducts. This paper focuses specifically on the vibratory response of a rectangular duct of finite length excited by an internal turbulent flow. A semi-analytical model taking into account the modal response of the structure due to both aerodynamic and acoustic contributions is derived. The aerodynamic component of the excitation is applied on the basis of Corcos model where the power spectral density of the wall pressure is determined experimentally. The acoustic component is based on the propagating modes in the duct where the acoustic modal contribution are extracted via cross-spectral densities. The vibrational response is given for a 0.2 × 0.1 × 0.5 m3 duct made of 3 mm steel plates excited by 20 m/s or 30 m/s flows. Comparisons between experimental results and numerical predictions show a good agreement. The competition between acoustic and aerodynamic components is highlighted.

  7. Hot Surface Ignition of A Composite Fuel Droplet

    Directory of Open Access Journals (Sweden)

    Glushkov Dmitrii O.

    2015-01-01

    Full Text Available The present study examines the characteristics of conductive heating (up to ignition temperature of a composite fuel droplet based on coal, liquid petroleum products, and water. In this paper, we have established the difference between heat transfer from a heat source to a fuel droplet in case of conductive (hot surface and convective (hot gas heat supply. The Leidenfrost effect influences on heat transfer characteristics significantly due to the gas gap between a composite fuel droplet and a hot surface.

  8. Numerical model describing the heat transfer between combustion products and ventilation-system duct walls

    International Nuclear Information System (INIS)

    Bolstad, J.W.; Foster, R.D.; Gregory, W.S.

    1983-01-01

    A package of physical models simulating the heat transfer processes occurring between combustion gases and ducts in ventilation systems is described. The purpose of the numerical model is to predict how the combustion gas in a system heats up or cools down as it flows through the ducts in a ventilation system under fire conditions. The model treats a duct with (forced convection) combustion gases flowing on the inside and stagnant ambient air on the outside. The model is composed of five submodels of heat transfer processes along with a numerical solution procedure to evaluate them. Each of these quantities is evaluated independently using standard correlations based on experimental data. The details of the physical assumptions, simplifications, and ranges of applicability of the correlations are described. A typical application of this model to a full-scale fire test is discussed, and model predictions are compared with selected experimental data

  9. Modified nasolacrimal duct stenting

    International Nuclear Information System (INIS)

    Tian Min; Jin Mei; Chen Huanjun; Li Yi

    2008-01-01

    Objective: Traditional nasolacrimal duct stenting possesses some shortcoming including difficulty of pulling ball head guide wire from the nasal cavity with turbinate hypertrophy and nasal septal deviation. The new method of nose-oral tube track establishment can overcome the forementioned and increase the successful rate. Methods: 5 F catheter and arterial sheath were modified to be nasolacrimal duct stent delivery device respectively. Antegrade dacryocystography was taken firstly to display the obstructed site and followed by the modified protocol of inserting the guide wire through nasolacrimal duct and nasal cavity, and establishing the stent delivery track for retrograde stent placement. Results: 5 epiphora patients with failure implantation by traditional method were all succeeded through the modified stenting (100%). During 6-mouth follow-up, no serious complications and reocclusion occurred. Conclusion: The establishment of eye-nose-mouth-nose of external nasal guide wire track can improve the successful rate of nasolacrimal duct stenting. (authors)

  10. The "flying" bile duct: avulsion of the common bile duct in a plane crash survivor.

    LENUS (Irish Health Repository)

    Mohan, H

    2012-02-01

    Blunt trauma is an unusual cause of extrahepatic bile duct injury. This is a case of a 51-year-old gentleman who sustained a significant seatbelt injury in a plane crash. Laparotomy, performed due to persistent abdominal pain, revealed that the common bile duct (CBD) was completely avulsed from the duodenum. Following insertion of drains and transfer to a hepatobiliary centre, the devascularised CBD was excised and replaced with a roux-en-y hepaticojejunostomy. Necrotic tissue was debrided from the pancreatic head. A persistent bile leak developed from the sub-hepatic drain. Repeat laparotomy revealed a bile leak from small ducts on the liver surface. Ligation of the ducts and bioglue sealing of the area were successfully performed. Subsequent to this a pancreatic fistula developed from the main pancreatic duct, which has since resolved. This unusual case illustrates the need for prompt recognition and early repair to optimise outcomes in traumatic CBD injury.

  11. Lightweight Exhaust Manifold and Exhaust Pipe Ducting for Internal Combustion Engines

    Science.gov (United States)

    Northam, G. Burton (Inventor); Ransone, Philip O. (Inventor); Rivers, H. Kevin (Inventor)

    1999-01-01

    An improved exhaust system for an internal combustion gasoline-and/or diesel-fueled engine includes an engine exhaust manifold which has been fabricated from carbon- carbon composite materials in operative association with an exhaust pipe ducting which has been fabricated from carbon-carbon composite materials. When compared to conventional steel. cast iron. or ceramic-lined iron paris. the use of carbon-carbon composite exhaust-gas manifolds and exhaust pipe ducting reduces the overall weight of the engine. which allows for improved acceleration and fuel efficiency: permits operation at higher temperatures without a loss of strength: reduces the "through-the wall" heat loss, which increases engine cycle and turbocharger efficiency and ensures faster "light-off" of catalytic converters: and, with an optional thermal reactor, reduces emission of major pollutants, i.e. hydrocarbons and carbon monoxide.

  12. Using Innovative Techniques for Manufacturing Rocket Engine Hardware

    Science.gov (United States)

    Betts, Erin M.; Reynolds, David C.; Eddleman, David E.; Hardin, Andy

    2011-01-01

    Many of the manufacturing techniques that are currently used for rocket engine component production are traditional methods that have been proven through years of experience and historical precedence. As we enter into a new space age where new launch vehicles are being designed and propulsion systems are being improved upon, it is sometimes necessary to adopt new and innovative techniques for manufacturing hardware. With a heavy emphasis on cost reduction and improvements in manufacturing time, manufacturing techniques such as Direct Metal Laser Sintering (DMLS) are being adopted and evaluated for their use on J-2X, with hopes of employing this technology on a wide variety of future projects. DMLS has the potential to significantly reduce the processing time and cost of engine hardware, while achieving desirable material properties by using a layered powder metal manufacturing process in order to produce complex part geometries. Marshall Space Flight Center (MSFC) has recently hot-fire tested a J-2X gas generator discharge duct that was manufactured using DMLS. The duct was inspected and proof tested prior to the hot-fire test. Using the Workhorse Gas Generator (WHGG) test setup at MSFC?s East Test Area test stand 116, the duct was subject to extreme J-2X gas generator environments and endured a total of 538 seconds of hot-fire time. The duct survived the testing and was inspected after the test. DMLS manufacturing has proven to be a viable option for manufacturing rocket engine hardware, and further development and use of this manufacturing method is recommended.

  13. Duct having oscillatory side wall

    Science.gov (United States)

    Sprouse, Kenneth M.

    2018-04-03

    A pump system includes a particulate consolidator pump that has a pump outlet. A duct is coupled to the pump outlet. The duct has a wall that is coupled with an oscillator. The oscillator is operable to oscillate the wall at a controlled frequency. The controlled frequency is selected with respect to breaking static bridging of particulate in the duct due, at least in part, to consolidation of the particulate from a downstream check valve.

  14. The correlation between the dilated extent of bile duct and gallbladder and low bile duct obstructive jaundice diseases

    International Nuclear Information System (INIS)

    Wang Zhongqiu; Lu Guangming; Li Jieshou; Li Weiqin

    2005-01-01

    Objective: To evaluate the diagnostic value about the dilated extent of bile duct and gallbladder in low biliary obstructive diseases. Methods: CT and ERCP findings of 105 patients with low biliary obstructive disease were retrospectively analyzed. The dilated extent of intrahepatic and extra- hepatic bile duct and gallbladder were classified into seven types: Type I: severe dilatation of intrahepatic and extrahepatic bile duct and gallbladder; Type II: severe dilatation of extrahepatic bile duct and gallbladder and slight dilated intrahapetic bile duct; Type III: severe dilatation of intrahepatic and extrahepatic bile duct without or slight dilatation of gallbladder; Type IV: severe extrahepatic bile duct dilatation without or slight dilatation of intrahepatic bile duct and gallbladder; Type V: severe intrahepatic bile duct dilatation without or with slight dilatation of extrahepatic bile duct and gallbladder; Type VI: severe gallbladder dilatation without or with slight intrahepatic and extra- hepatic bile duct dilatation; Type VII: without or with slight dilatation of intrahepatic and extrahepatic bile duct and gallbladder. The biliary system dilated extent of low biliary obstructive disease on CT and ERCP were compared with results of clinical, operation, and pathology. Results: Thirty-three cases of tumor and 72 cases of non-tumor were proved by clinical and operation in 105 patients with low biliary obstructive disease. In 33 tumor patients, 16 patients were identified as Type I, 10 patients Type II, 4 patients Type III, 1 patient Type IV, 2 patients Type VII. In 72 non-tumor patients, 4 patients were identified as Type I, 4 patients Type II, 9 patients Type III, 33 patients Type IV, 2 patients Type V, 11 patients Type VI, 19 patients Type VII. A large difference between I, II type and III-VII type biliary dilatation existed in tumor and non-tumor group (χ 2 =47.33, P<0.01). Conclusion:Low obstructive biliary diseases are closely correlated with the dilated

  15. Glechoma hederacea extracts attenuate cholestatic liver injury in a bile duct-ligated rat model.

    Science.gov (United States)

    Wang, Ya-Yu; Lin, Shih-Yi; Chen, Wen-Ying; Liao, Su-Lan; Wu, Chih-Cheng; Pan, Pin-Ho; Chou, Su-Tze; Chen, Chun-Jung

    2017-05-23

    In traditional Chinese medicine, Glechoma hederacea is frequently prescribed to patients with cholelithiasis, dropsy, abscess, diabetes, inflammation, and jaundice. Polyphenolic compounds are main bioactive components of Glechoma hederacea. This study was aimed to investigate the hepatoprotective potential of hot water extract of Glechoma hederacea against cholestatic liver injury in rats. Cholestatic liver injury was produced by ligating common bile ducts in Sprague-Dawley rats. Saline and hot water extract of Glechoma hederacea were orally administrated using gastric gavages. Liver tissues and bloods were collected and subjected to evaluation using histological, molecular, and biochemical approaches. Using a rat model of cholestasis caused by bile duct ligation (BDL), daily oral administration of Glechoma hederacea hot water extracts showed protective effects against cholestatic liver injury, as evidenced by the improvement of serum biochemicals, ductular reaction, oxidative stress, inflammation, and fibrosis. Glechoma hederacea extracts alleviated BDL-induced transforming growth factor beta-1 (TGF-β1), connective tissue growth factor, and collagen expression, and the anti-fibrotic effects were accompanied by reductions in α-smooth muscle actin-positive matrix-producing cells and Smad2/3 activity. Glechoma hederacea extracts attenuated BDL-induced inflammatory cell infiltration/accumulation, NF-κB and AP-1 activation, and inflammatory cytokine production. Further studies demonstrated an inhibitory effect of Glechoma hederacea extracts on the axis of high mobility group box-1 (HMGB1)/toll-like receptor-4 (TLR4) intracellular signaling pathways. The hepatoprotective, anti-oxidative, anti-inflammatory, and anti-fibrotic effects of Glechoma hederacea extracts seem to be multifactorial. The beneficial effects of daily Glechoma hederacea extracts supplementation were associated with anti-oxidative, anti-inflammatory, and anti-fibrotic potential, as well as down

  16. Hot conditioning equipment conceptual design report

    International Nuclear Information System (INIS)

    Bradshaw, F.W.

    1996-01-01

    This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage

  17. Hot conditioning equipment conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, F.W., Westinghouse Hanford

    1996-08-06

    This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage.

  18. Long-term follow-up after choledochojejunostomy for bile duct stones with complex clearance of the bile duct

    NARCIS (Netherlands)

    Gouma, D. J.; Konsten, J.; Soeters, P. B.; Von Meyenfeldt, M.; Obertop, H.

    1989-01-01

    In this retrospective study, the long-term follow-up of patients undergoing choledochojejunostomy (Roux-en-Y) for bile duct stones with complex clearance of the bile duct is evaluated. Bile duct exploration and subsequent choledochojejunostomy (Roux-en-Y) was performed in 43 patients (median age 67

  19. A Plug-and-Play Duct System Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Beach, R. [IBACOS, Inc., Pittsburgh, PA (United States); Dickson, B. [IBACOS, Inc., Pittsburgh, PA (United States); Grisolia, A. [IBACOS, Inc., Pittsburgh, PA (United States); Poerschke, A. [IBACOS, Inc., Pittsburgh, PA (United States); Rapport, A. [IBACOS, Inc., Pittsburgh, PA (United States)

    2017-07-01

    This report describes an air distribution system composed of a series of uniformly-sized ducts that terminate in rooms throughout the home and return to a central manifold, similar in fashion to a “home-run” cross-linked polyethylene plumbing system. With a well-designed manifold, each duct receives an equal static pressure potential for airflow from the air handling unit, and the number of needed ducts for each room are simply attached to fittings located on the manifold; in this sense, the system is plug-and-play (PnP). As indicated, all ducts in the PnP system are identical in size and small enough to fit in the ceiling and wall cavities of a house (i.e., less than 3.5-in. outer diameter). These ducts are also more appropriately sized for the lower airflow requirements of modern, energy-efficient homes; therefore, the velocity of the air moving through the duct is between that of conventional duct systems (approximately 700 ft/min) and high-velocity systems (more than 1,500 ft/min) on the market today. The PnP duct system uses semi-rigid plastic pipes, which have a smooth inner wall and are straightforward to install correctly, resulting in a system that has minimal air leakage. However, plastic ducts are currently not accepted by code for use in residential buildings; therefore, the project team considered other duct materials for the system that are currently accepted by code, such as small-diameter, wirehelix, flexible ductwork.

  20. A Plug-and-Play Duct System Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Beach, Robert [IBACOS, Inc., Pittsburgh, PA (United States); Dickson, Bruce [IBACOS, Inc., Pittsburgh, PA (United States); Grisolia, Anthony [IBACOS, Inc., Pittsburgh, PA (United States); Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States); Rapport, Ari [IBACOS, Inc., Pittsburgh, PA (United States)

    2017-07-10

    This report describes an air distribution system composed of a series of uniformly-sized ducts that terminate in rooms throughout the home and return to a central manifold, similar in fashion to a “home-run” cross-linked polyethylene plumbing system. With a well-designed manifold, each duct receives an equal static pressure potential for airflow from the air handling unit, and the number of needed ducts for each room are simply attached to fittings located on the manifold; in this sense, the system is plug-and-play (PnP). As indicated, all ducts in the PnP system are identical in size and small enough to fit in the ceiling and wall cavities of a house (i.e., less than 3.5-in. outer diameter). These ducts are also more appropriately sized for the lower airflow requirements of modern, energy-efficient homes; therefore, the velocity of the air moving through the duct is between that of conventional duct systems (approximately 700 ft/min) and high-velocity systems (more than 1,500 ft/min) on the market today. The PnP duct system uses semi-rigid plastic pipes, which have a smooth inner wall and are straightforward to install correctly, resulting in a system that has minimal air leakage. However, plastic ducts are currently not accepted by code for use in residential buildings; therefore, the project team considered other duct materials for the system that are currently accepted by code, such as small-diameter, wirehelix, flexible ductwork.

  1. Investigation of geothermal development and promotion for fiscal 1997. Fluid geochemical investigation (hot-spring gas) report (No. B-5 Musadake area); 1997 nendo chinetsu kaihatus sokushin chosa. Ryutai chikagaku chosa (onsen gas) hokokusho (No.B-5 Musadake chiiki)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    This investigation elucidated the possible existence of geothermal reservoir layer in the subject area by studying and analyzing the hot-spring gasses of Musadake. The Musadake area is the one extending over Shibetu-cho and Nakashibetu-cho, Shibetu district, Hokkaido. The sampling of the hot-spring gasses was carried out at three natural gusher sites and one hot spring well site. The gasses in the Kawakita hot spring is most affected by volcanic gasses. The origin of the volcanic gasses is a magmatic gas of andesite nature the {sup 3}He/{sup 4}He ratio of which is 8X10{sup -6} or about. As a result of the analysis, the hot-spring water is Na-Cl type, high salt concentrated, and 200 degrees C in temperature; from the result of a gas geochemical thermometer, it is estimated to be not less than 250 degrees C. In the tectonic viewpoint, the depth hot water is derived from the meteorite water that flows in through a bent zone incident to the Musadake-Shitabanupuri mountain fault and from the fossil sea water that exists in the underground depth; the depth hot water is formed by conduction heat from a magma reservoir that formed Musadake and by volcanic ejecta. This depth hot water rises along Kawakita south, Urappu River fault, etc., mixing with the meteorite water and forming the shallow reservoir layer. (NEDO)

  2. SNM holdup assessment of Los Alamos exhaust ducts

    International Nuclear Information System (INIS)

    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 235 U in a duct servicing a shut-down uranium-machining facility to 39 g of 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 235 U in a duct servicing analytical laboratories to 1 g of 235 U and 1 g of 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

  3. Hot coal gas desulfurization with manganese-based sorbents. Final report, September 1992--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hepworth, M.T.; Slimane, R.B.

    1994-11-01

    The focus of much current work being performed by the Morgantown Energy Technology Center (METC) of the Department of Energy on hot coal-derived fuel gas desulfurization is in the use of zinc-based sorbents. METC has shown interest in formulating and testing manganese-based pellets as alternative effective sulfur sorbents in the 700 to 1200{degree}C temperature range. To substantiate the potential superiority of Mn-based pellets, a systematic approach toward the evaluation of the desulfurizing power of single-metal sorbents is developed based on thermodynamic considerations. This novel procedure considered several metal-based sorbents and singled out manganese oxide as a prime candidate sorbent capable of being utilized under a wide temperature range, irrespective of the reducing power (determined by CO{sub 2}/CO ratio) of the fuel gas. Then, the thermodynamic feasibility of using Mn-based pellets for the removal of H{sub 2}S from hot-coal derived fuel gases, and the subsequent oxidative regeneration of loaded (sulfided) pellets was established. It was concluded that MnO is the stable form of manganese for virtually all commercially available coal-derived fuel gases. In addition, the objective of reducing the H{sub 2}S concentration below 150 ppMv to satisfy the integrated gasification combined cycle system requirement was shown to be thermodynamically feasible. A novel process is developed for the manufacture of Mn-based spherical pellets which have the desired physical and chemical characteristics required.

  4. Nasopalatine duct cyst: A case report

    Directory of Open Access Journals (Sweden)

    Saikrishna Pasupuleti

    2015-01-01

    Full Text Available Nasopalatine duct cyst (NPDC is the most common non-odontogenic cyst of oral cavity. Clinically, Nasopalatine duct cyst manifests as an asymptomatic swelling of the palate or the upper lip. Radiographically, it is seen as a heart-shaped radiolucency and can be confused with periapical pathology. The aim of this article is to report a case of a nasopalatine duct cyst in a 36-year-old patient which was misinterpreted for a periapical cyst. Diagnosis of a Nasopalatine duct cyst can be given through clinical, radiographical, and histopathological examination.

  5. Radiologic imaging of bile duct changes by clonorchiasis

    International Nuclear Information System (INIS)

    Kim, Myung Joon; Yoo, Hyung Sik; Lee, Jong Tae; Jung, Soon Hee

    1988-01-01

    The changes of the bile ducts were reviewed retrospectively in 38 patients of clonorchiasis by ultrasonography and/or CT. Diagnosis was made in 13 patients by cholecystectomy and exploration of the common bile duct, another 2 patients by segmentectomy and wedge resection of the liver, and 23 patients by stool examination. 14 of 36 cases done ultrasonography showed the parallel channel sign, and small nodular echoes around the dilated bile ducts. And 3 cases showed the echoes of worm of clonorchis sinensis in the common bile duct. 22 of 36 cases showed the parallel channel signs only. All cases (11) done CT showed diffuse dilatation of the peripheral bile ducts. 5 of 11 cases showed ring or tubular contrast enhancement around the dilated bile ducts. In 2 cases of liver resection, the bile ducts showed adenomatous hyperplasia and severe periductal fibrosis. Proliferation of blood vessels and infiltration of inflammatory cells were also seen. So we consider that the increased echoes of the bile duct wall, small nodular echoes around the bile ducts were attributed to the bile duct dilatation, severe adenomatous hyperplasia and periductal fibrosis. The ring or tubular contrast enhancement of the dilated bile ducts seems to be caused by the marked periductal inflammation resulting in capillary proliferation and the periductal fibrosis.

  6. Radiologic imaging of bile duct changes by clonorchiasis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myung Joon; Yoo, Hyung Sik; Lee, Jong Tae; Jung, Soon Hee [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1988-10-15

    The changes of the bile ducts were reviewed retrospectively in 38 patients of clonorchiasis by ultrasonography and/or CT. Diagnosis was made in 13 patients by cholecystectomy and exploration of the common bile duct, another 2 patients by segmentectomy and wedge resection of the liver, and 23 patients by stool examination. 14 of 36 cases done ultrasonography showed the parallel channel sign, and small nodular echoes around the dilated bile ducts. And 3 cases showed the echoes of worm of clonorchis sinensis in the common bile duct. 22 of 36 cases showed the parallel channel signs only. All cases (11) done CT showed diffuse dilatation of the peripheral bile ducts. 5 of 11 cases showed ring or tubular contrast enhancement around the dilated bile ducts. In 2 cases of liver resection, the bile ducts showed adenomatous hyperplasia and severe periductal fibrosis. Proliferation of blood vessels and infiltration of inflammatory cells were also seen. So we consider that the increased echoes of the bile duct wall, small nodular echoes around the bile ducts were attributed to the bile duct dilatation, severe adenomatous hyperplasia and periductal fibrosis. The ring or tubular contrast enhancement of the dilated bile ducts seems to be caused by the marked periductal inflammation resulting in capillary proliferation and the periductal fibrosis.

  7. Slug-annular transition with particular reference to narrow rectangular ducts

    International Nuclear Information System (INIS)

    Jones, O.C. Jr.; Zuber, N.

    1978-01-01

    The transition from slug-flow to annular-flow in two-phase, gas-liquid mixtures is analyzed. A transition equation is derived which agrees well when compared with objective data determined from the disappearance of the low-void peak in the void fluctuation probability density in a rectangular duct. Application to other geometries is suggested and tabular recommendations given for determination of the drift flux coefficient, K, based on results in the literature

  8. Facility for endurance tests of thermal insulations

    International Nuclear Information System (INIS)

    Mauersberger, R.

    1984-01-01

    In the following report the design and construction of an experimental facility for endurance tests of thermal insulations is presented. It's name in abbreviation is 'ADI' standing for the German words A nlage zum Dauertest von Isolierungen . This test facility was build by HRB in order to investigate the performance of thermal insulation systems of hot gas ducts for the process heat-reactor-project. The tests are intended to simulate the conditions of reactor operation. They include short-time experiments for selection of insulation-concepts and in a second step long-time experiments as performance tests. During these tests are measured the effective heat conductivity the local heat losses the temperature profiles of the insulation, of the fixing elements and along the wall of the duct. The design-data required to perform all these tasks are shown in the first picture: The gas-atmosphere must be Helium in tests like in reactor with regard to the special thermal and hydraulic properties of Helium and to the influence of Helium on mechanic friction and wear. The hot gas temperature in the PNP-reactor will be 950 deg. C and should be equal in the experiments. The temperature on the cold side of the insulation has to be adjustable from 50 deg. C up to 300 deg. C. The Helium pressure in the hot gas ducts of a HTR-plant is about 42 bar. The ADI was laid out for 70 bar to cover the hole range of interest. A Helium mass flow has to stream through the insulated test duct in order to realize equal temperatures on the hot side of the insulation. A flow rate of 4,5 kg/s is sufficient for this requirement. The axial pressure gradient along the insulation must be the same as in the reactor, because this has an essential influence on the heat losses. This pressure gradient is about 40 Pa/m

  9. Effect of duct geometry on Wells turbine performance

    International Nuclear Information System (INIS)

    Shaaban, S.; Abdel Hafiz, A.

    2012-01-01

    Highlights: ► A Wells turbine duct design in the form of venturi duct is proposed and investigated. ► Optimum duct geometry is identified. ► Up to 14% increase of the turbine power can be achieved using the optimized duct geometry. ► Up to 9% improve of the turbine efficiency is attained by optimizing the turbine duct geometry. ► The optimized duct geometry results in tangible delay of the turbine stalling point. - Abstract: Wells turbines can represent important source of renewable energy for many countries. An essential disadvantage of Wells turbines is their low aerodynamic efficiency and consequently low power produced. In order to enhance the Wells turbine performance, the present research work proposes the use of a symmetrical duct in the form of a venturi tube with turbine rotor located at throat. The effects of duct area ratio and duct angle are investigated in order to optimize Wells turbine performance. The turbine performance is numerically investigated by solving the steady 3D incompressible Reynolds Averaged Navier–Stocks equation (RANS). A substantial improve of the turbine performance is achieved by optimizing the duct geometry. Increasing both the duct area ratio and duct angle increase the acceleration and deceleration upstream and downstream the rotor respectively. The accelerating flow with thinner boundary layer thickness upstream the rotor reduces the flow separation on the rotor suction side. The downstream diffuser reduces the interaction between tip leakage flow and blade suction side. Up to 14% increase in turbine power and 9% increase in turbine efficiency are achieved by optimizing the duct geometry. On other hand, a tangible delay of the turbine stall point is also detected.

  10. Mechanical Property and Its Comparison of Superalloys for High Temperature Gas Cooled Reactor

    International Nuclear Information System (INIS)

    Kim, Woo Gon; Kim, D. W.; Ryu, W. S.; Han, C. H.; Yoon, J. H.; Chang, J.

    2005-01-01

    Since structural materials for high temperature gas cooled reactor are used during long period in nuclear environment up to 1000 .deg. C, it is important to have good properties at elevated temperature such as mechanical properties (tensile, creep, fatigue, creep-fatigue), microstructural stability, interaction between metal and gas, friction and wear, hydrogen and tritium permeation, irradiation behavior, corrosion by impurity in He. Thus, in order to select excellent materials for the high temperature gas cooled reactor, it is necessary to understand the material properties and to gather the data for them. In this report, the items related to material properties which are needed for designing the high temperature gas cooled reactor were presented. Mechanical properties; tensile, creep, and fatigue etc. were investigated for Haynes 230, Hastelloy-X, In 617 and Alloy 800H, which can be used as the major structural components, such as intermediate heat exchanger (IHX), hot duct and piping and internals. Effect of He and irradiation on these structural materials was investigated. Also, mechanical properties; physical properties, tensile properties, creep and creep crack growth rate were compared for them, respectively. These results of this report can be used as important data to select superior materials for high temperature gas reactor

  11. Lorenz curve and Gini coefficient reveal hot spots and hot moments for nitrous oxide emissions

    Science.gov (United States)

    Identifying hot spots and hot moments of N2O emissions in the landscape is critical for monitoring and mitigating the emission of this powerful greenhouse gas. We propose a novel use of the Lorenz curve and Gini coefficient (G) to quantify the heterogeneous distribution of N2O emissions from a lands...

  12. Hot-gas-side heat transfer characteristics of subscale, plug-nozzle rocket calorimeter chamber

    Science.gov (United States)

    Quentmeyer, Richard J.; Roncace, Elizabeth A.

    1993-01-01

    An experimental investigation was conducted to determine the hot-gas-side heat transfer characteristics for a liquid-hydrogen-cooled, subscale, plug-nozzle rocket test apparatus. This apparatus has been used since 1975 to evaluate rocket engine advanced cooling concepts and fabrication techniques, to screen candidate combustion chamber liner materials, and to provide data for model development. In order to obtain the data, a water-cooled calorimeter chamber having the same geometric configuration as the plug-nozzle test apparatus was tested. It also used the same two showerhead injector types that were used on the test apparatus: one having a Rigimesh faceplate and the other having a platelet faceplate. The tests were conducted using liquid oxygen and gaseous hydrogen as the propellants over a mixture ratio range of 5.8 to 6.3 at a nominal chamber pressure of 4.14 MPa abs (600 psia). The two injectors showed similar performance characteristics with the Rigimesh faceplate having a slightly higher average characteristic-exhaust-velocity efficiency of 96 percent versus 94.4 percent for the platelet faceplate. The throat heat flux was 54 MW/m(sup 2) (33 Btu/in.(sup 2)-sec) at the nominal operating condition, which was a chamber pressure of 4.14 MPa abs (600 psia), a hot-gas-side wall temperature of 730 K (1314 R), and a mixture ratio of 6.0. The chamber throat region correlation coefficient C(sub g) for a Nusselt number correlation of the form Nu =C(sub g)Re(sup 0.8)Pr(sup 0.3) averaged 0.023 for the Rigimesh faceplate and 0.026 for the platelet faceplate.

  13. The growth of GaN films by alternate source gas supply hot-mesh CVD method

    Energy Technology Data Exchange (ETDEWEB)

    Komae, Yasuaki; Saitou, Takeshi [Nagaoka University of Technology, Nagaoka 940-2188 (Japan); Suemitsu, Maki; Ito, Takashi [Center of Interdisciplinary Research, Tohoku University, Sendai 980-8578 (Japan); Endoh, Tetsuo [Research Institute of Electrical Communication, Tohoku University, Sendai 980-8577 (Japan); Nakazawa, Hideki [Faculty of Science and Technology, Hirosaki University, Hirosaki 036-8561 (Japan); Narita, Yuzuru [Faculty of Engineering, Yamagata University, Yonezawa 992-8510 (Japan); Takata, Masasuke; Akahane, Tadashi [Nagaoka University of Technology, Nagaoka 940-2188 (Japan); Yasui, Kanji, E-mail: kyasui@vos.nagaokaut.ac.j [Nagaoka University of Technology, Nagaoka 940-2188 (Japan)

    2009-04-30

    Gallium nitride (GaN) films and Aluminium nitride (AlN) layers were deposited on SiC/Si (111) substrates by an alternating source gas supply or an intermittent supply of a source gas such as ammonia (NH{sub 3}), trimethylgallium (TMG) or trimethylaluminum (TMA) in a hot-mesh chemical vapor deposition (CVD) apparatus. The AlN layer was deposited as a buffer layer using NH{sub 3} and TMA on a SiC layer grown by carbonization on Si substrates using propane (C{sub 3}H{sub 8}). GaN films were grown on an AlN layer by a reaction between NH{sub x} radicals generated on a ruthenium (Ru) coated tungsten (W)-mesh and TMG molecules. An alternating source gas supply or an intermittent supply of one of the source gases during the film growth are expected to be effective for the suppression of gas phase reactions and for the enhancement of precursor migration on the substrate surface. By the intermittent supply of alkylmetal gas only during the growth of the AlN layer, the defect generation in the GaN films was reduced. GaN film growth by intermittent supply on an AlN buffer layer, however, did not lead to the improvement of the film quality.

  14. ITER L 6 equatorial maintenance duct remote handling study

    International Nuclear Information System (INIS)

    Millard, J.

    1996-09-01

    The status and conclusions of a preliminary study of equatorial maintenance duct remote handling is reported. Due to issues with the original duct design a significant portion of the study had to be refocused on equatorial duct layout studies. The study gives an overview of some of the options for design of these ducts and the impact of the design on the equipment to work in the duct. To develop a remote handling concept for creating access through the ducts the following design tasks should be performed: define the operations sequences for equatorial maintenance duct opening and closing; review the remote handling requirements for equatorial maintenance duct opening and closing; design concept for door and pipe handling equipment and to propose preliminary procedures for material handling outsides the duct. 35 figs

  15. Effects of rotation on flow in an asymmetric rib-roughened duct: LES study

    International Nuclear Information System (INIS)

    Borello, D.; Salvagni, A.; Hanjalić, K.

    2015-01-01

    Highlights: • Ribbed duct reproduces most of the phenomena occurring in internal cooling channels of blade turbines (rotor and stator). • LES analysis of the flow in a ribbed duct was carried out aiming at detecting the influence of rotation on the turbulence. • In destabilizing conditions, rotation enhances turbulence close to the ribbed duct thus enhancing removal of fluid from the wall and improving mixing. • In stabilizing conditions, turbulence is suppressed by rotation close to the ribbed wall. - Abstract: We report on large-eddy simulations (LES) of fully-developed asymmetric flow in a duct of a rectangular cross-section in which square-sectioned, equally-spaced ribs oriented perpendicular to the flow direction, were mounted on one of the walls. The configuration mimics a passage of internal cooling of a gas-turbine blade. The duct flow at a Reynolds number Re = 15,000 (based on hydraulic diameter D_h and bulk flow velocity U_0) was subjected to clock-wise (stabilising) and anti-clock-wise (destabilising) orthogonal rotation at a moderate rotational number Ro = ΩD_h/U_0 = 0.3, where Ω is the angular velocity. The LES results reproduced well the available experimental results of Coletti et al. (2011) (in the mid-plane adjacent to the ribbed wall) and provided insight into the whole duct complementing the reference PIV measurement. We analyzed the effects of stabilising and destabilising rotation on the flow, vortical structures and turbulence statistics by comparison with the non-rotating case. The analysis includes the identification of depth of penetration of the rib-effects into the bulk flow, influence of flow three-dimensionality and the role of secondary motions, all shown to be strongly affected by the rotation and its direction.

  16. Spectral measurements of gamma radiation streaming through ducts

    International Nuclear Information System (INIS)

    Meenakshisundaram, P.K.; Bhatnagar, V.M.; Raghunath, V.M.; Gopinath, D.V.

    1979-01-01

    The paper presents the spectral measurements of gamma radiation streaming through multi-legged rectangular concrete ducts for cesium-137 and cobald-60 sources. Effect of lead lining the inner surface of the duct on the streaming radiation spectrum and optimization of liner thickness for minimum streaming radiation dose have been studied. For three-legged ducts, a comparative analysis of lead lining the entire duct as against lining any one or both the corners of the duct is reported. It is seen that lead lining any one of the corners would reduce the streaming radiation dose by a factor of 5 to 12. Lining both the corners which is nearly as effective as lining the entire duct reduces the dose by a factor of 16 to 60 depending on the soruce energy and duct dimensions. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Financial Aspects of Bile Duct Injuries.

    Science.gov (United States)

    Palaz Alı, Ozgkıour; Ibis, Abdil Cem; Gurtekin, Basak

    2017-11-04

    BACKGROUND Major bile duct injury is the most worrisome complication of cholecystectomy. There is no detailed data about the incidence or treatment-related costs of bile duct injuries in Turkey. We aimed to determine prevalence and therapeutic costs of patients with major biliary duct injuries managed in our department, and further estimate a projection of these parameters at the national level. MATERIAL AND METHODS All patients admitted due to bile duct injury during cholecystectomy from 2011 to 2014 were included. Healthcare costs were calculated by summing of their all treatment-related costs in Istanbul Medical Faculty. We collected 2014-2015 data on number of patients diagnosed with cholecystitis in Turkey, the number of cholecystectomies, and the number of the interventions performed following these initial surgeries, which were obtained from the Turkish Social Security Institution. RESULTS Forty-nine patients were enrolled and bilioenteric diversion was performed in 39 patients: 20.4% of patients had Bismuth II, 38.8% had Bismuth III, and 40.8% had Bismuth IV biliary stricture. Comparison of stricture types with total costs, days of hospitalization, and outpatient clinic costs revealed significant differences. Mean total cost of corrective surgeries was 9199 TRY. We estimated that 1.5% to 2.4% of patients who underwent cholecystectomy in Turkey have bile duct injury (including 0.3% with major bile duct injury). CONCLUSIONS New preventive strategies should be used to avoid bile duct injuries, which have a huge financial impact on the national economy.

  19. Discussion of Carbon Emissions for Charging Hot Metal in EAF Steelmaking Process

    Science.gov (United States)

    Yang, Ling-zhi; Jiang, Tao; Li, Guang-hui; Guo, Yu-feng

    2017-07-01

    As the cost of hot metal is reduced for iron ore prices are falling in the international market, more and more electric arc furnace (EAF) steelmaking enterprises use partial hot metal instead of scrap as raw materials to reduce costs and the power consumption. In this paper, carbon emissions based on 1,000 kg molten steel by charging hot metal in EAF steelmaking is studied. Based on the analysis of material and energy balance calculation in EAF, the results show that 146.9, 142.2, 137.0, and 130.8 kg/t of carbon emissions are produced at a hot metal ratio of 0 %, 30 %, 50 %, and 70 %, while 143.4, 98.5, 65.81, and 31.5 kg/t of carbon emissions are produced at a hot metal ratio of 0 %, 30 %, 50 %, and 70 % by using gas waste heat utilization (coal gas production) for EAF steelmaking unit process. However, carbon emissions are increased by charging hot metal for the whole blast furnace-electric arc furnace (BF-EAF) steelmaking process. In the condition that the hot metal produced by BF is surplus, as carbon monoxide in gas increased by charging hot metal, the way of coal gas production can be used for waste heat utilization, which reduces carbon emissions in EAF steelmaking unit process.

  20. Diatomaceous earth and activated bauxite used as granular sorbents for the removal of sodium chloride vapor from hot flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Swift, W.M.; Johnson, I.

    1980-01-01

    Diatomaceous earth and activated bauxite were tested as granular sorbents for use as filter media in granular-bed filters for the removal of gaseous alkali metal compounds from the hot (800/sup 0/C) flue gas of PFBC. Tests were performed at atmospheric pressure, using NaCl vapor transported in relatively dry simulated flue gas of PFBC. Either a fixed-bed combustor or a high-temperature sorption test rig was used. The effects of sorbent bed temperature, superficial gas velocity, gas hourly space velocity, and NaCl-vapor concentration in flue gas on the sorption behavior of these two sorbents and their ultimate sorption capacities were determined. Both diatomaceous earth and activated bauxite were found to be very effective in removing NaCl vapor from flue gas. Preliminary cost evaluations showed that they are economically attractive as granular sorbents for cleaning alkali vapor from simulated flue gas.

  1. Vitellointestinal Duct Anomalies in Infancy.

    Science.gov (United States)

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

    2016-01-01

    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. 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. 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. 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.

  2. Cholangiographic evaluation of bile duct carcinoma

    International Nuclear Information System (INIS)

    Nichols, D.A.; MacCarty, R.L.; Gaffey, T.A.

    1983-01-01

    Cholangiograms and clinical histories of 82 patients with biopsy-proved bile duct carcinoma were reviewed. The carcinomas were classified according to morphologic findings and clinical outcome. Ulcerative colitis and antecedent inflammatory disease of the biliary tree, particularly primary sclerosing cholangitis, seem to predispose to the development of bile duct carcinoma. Focal stenotic lesions were the most common morphologic type (62/82). Polypoid carcinomas and diffuse sclerosing carcinomas were less common and of about equal frequency. Prognosis was best for patients with polypoid carcinomas and worst for those with diffuse sclerosing carcinomas. In 69 cases (84%), the tumors involved the intrahepatic or proximal extrahepatic ducts, makin curative resection difficult or impossible. Patients with carcinomas limited to the more distal extrahepatic bile ducts had a longer average survival and a higher probability of surgical cure. Proper management of patients with bile duct carcinoma requires a complete and accurate cholangiographic evaluation of the morphology, location, and extent of the disease

  3. Air-filled left hepatic duct: the saber sign as an aid to the radiographic diagnosis of pneumobilia

    International Nuclear Information System (INIS)

    Lewandowski, B.J.; Withers, C.; Winsberg, F.

    1984-01-01

    In the supine patient, gas rises to the left hepatic duct. Radiographically, this can be recognized as a saber-shaped lucency to the right of the spine. In a retrospective analysis and review of the radiographs of 40 patients shown to have gas in the biliary tree by ultrasound (US), computed tomography (CT), or radiography, the diagnosis could be made in 37 patients. In 18 of these 37 cases pneumobilia could be identified by the saber-shaped distribution of gas

  4. Promethus Hot Leg Piping Concept

    International Nuclear Information System (INIS)

    AM Girbik; PA Dilorenzo

    2006-01-01

    The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept

  5. Effect of Al Hot-Dipping on High-Temperature Corrosion of Carbon Steel in N2/0.1% H2S Gas

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Abro

    2016-02-01

    Full Text Available High-temperature corrosion of carbon steel in N2/0.1% H2S mixed gas at 600–800 °C for 50–100 h was studied after hot-dipping in the aluminum molten bath. Hot-dipping resulted in the formation of the Al topcoat and the Al-Fe alloy layer firmly adhered on the substrate. The Al-Fe alloy layer consisted primarily of a wide, tongue-like Al5Fe2 layer and narrow Al3Fe layer. When corroded at 800 °C for 100 h, the Al topcoat partially oxidized to the protective but non-adherent α-Al2O3 layer, and the interdiffusion converted the Al-Fe alloy layer to an (Al13Fe4, AlFe3-mixed layer. The interdiffusion also lowered the microhardness of the hot-dipped steel. The α-Al2O3 layer formed on the hot-dipped steel protected the carbon steel against corrosion. Without the Al hot-dipping, the carbon steel failed by forming a thick, fragile, and non-protective FeS scale.

  6. Method of separating radioactive krypton gas

    International Nuclear Information System (INIS)

    Kimura, Shigeru; Awada, Yoshihisa.

    1975-01-01

    Object: To effectively and safely separate and recover Kr-85, which requires a long storage period for attenuating radioactivity, from a mixture gas consisting of Kr-85 and Xe by a liquefaction distillation method. Structure: A mixture gas consisting of Kr and Xe is subjected to heat exchange in a cooler with Freon gas from a plurality of distillation towers for its temperature reduction from normal temperature to a lower temperature, and then it is supplied to a distillation tower. The distillation tower is held at a pressure above 15 ata, preferably around 20 ata, and a condenser provided at the top of the distillation tower is furnished with Freon as cooling medium. The rare mixture gas is distilled by liquefaction within a distillation tower, and Kr-85 is obtained from a top duct while obtaining Xe from a bottom duct. Xe after separation by liquefaction is returned to a rare mixture gas supply inlet of a liquefaction distillation means for repeated refinement in the distillation tower. (Kamimura, M.)

  7. Fatal liver gas gangrene after biliary surgery

    Directory of Open Access Journals (Sweden)

    Yui Miyata

    2017-01-01

    Discussion: Liver gas gangrene is rare and has a high mortality rate. This case seems to have arisen from an immunosuppressive state after major surgery with biliary reconstruction for bile duct cancer and subsequent gastrointestinal bleeding, leading to gas gangrene of the liver.

  8. New concept of the buildup factor in bent ducts

    International Nuclear Information System (INIS)

    Faik Ouahab, Z.; Jehouani, A.; Groetz, J.-E.

    2011-01-01

    A major problem confronting the radiation shielding designer is the accurate determination of neutron streaming through various penetrations in walls, ducts and mazes. The previous studies on neutron transmission were performed through empty ducts. The aim of this work is to evaluate the neutron transmission probability through a filled bent duct and the proposition of a new concept of the buildup factor for neutrons in multilegged ducts. An angular biaising technique is used in the Monte Carlo simulations to accelerate the calculation convergence. Results are first compared with those obtained by the MCNPX code. For an empty bent duct, the neutron transmission is only due to the neutron reflection on the duct wall. For a filled duct, the major contribution is due to the scattering on the atoms filling the duct.

  9. Molecular Mechanisms of Bile Duct Development

    OpenAIRE

    Zong, Yiwei; Stanger, Ben Z.

    2010-01-01

    The mammalian biliary system, consisting of the intrahepatic and extrahepatic bile ducts, is responsible for transporting bile from the liver to the intestine. Bile duct dysfunction, as is seen in some congenital biliary diseases such as Alagille syndrome and biliary atresia, can lead to the accumulation of bile in the liver, preventing the excretion of detoxification products and ultimately leading to liver damage. Bile duct formation requires coordinated cell-cell interactions, resulting in...

  10. Unilateral Duplication Of Parotid Duct. A Rare Anatomical Variation

    Directory of Open Access Journals (Sweden)

    Humberto Ferreira Arquez

    2017-11-01

    Full Text Available Background: The paired parotid glands are the largest of the major salivary glands and produces mainly serous secretions. The secretion of this gland reaches the oral cavity through single parotid duct (Stensen’s duct. The parotid duct begins at the anterior border of the gland, crosses the masseter muscle, and then pierces the buccinator muscle to reach the mucosa lining the mouth at the level of the cheek. The purpose of this study is determine the morphologic features of the parotid duct and describe an anatomical variation until now unreported. Methods and Findings: A total of 17 cadavers were used for this study in the Morphology Laboratory at the University of Pamplona. In a cadaver were findings: The main parotid duct originated two conducts: Left superior parotid duct and Left inferior parotid duct, is observed the criss-cross of the ducts, and then perforated the buccinator muscle and entered the oral cavity at a double parotid papilla containing a double opening, separated from each other in 0,98 mm. In the remaining  33 parotid regions (97.06% the parotid duct is conformed to the classical descriptions given in anatomical textbooks. Conclusions: The parotid duct anatomy is important for duct endoscopy, lithotripsy, sialography and trans-ductal facial nerve stimulation in the early stage of facial palsy in some cases. The anatomical variations also has clinical importance for parotid gland surgery and facial cosmetic surgery. To keep in mind the parotid duct variation will reduce iatrogenic injury risks and improve diagnosis of parotid duct injury.

  11. Change On The S-Z Effect Induced By The Cooling Flow CF On The Hot Electronic Gas At The Center OF The Clusters Of Galaxies

    Directory of Open Access Journals (Sweden)

    Enkelejd Caca

    2015-06-01

    Full Text Available ABSTRACT Building more accurate profiles for temperature and density of hot electronic gas concentrated in the center of clusters of galaxies is a constant problem in survey of Sunyeav Zeldovich effect SZ. An effect that consists in the inverse Compton effect of the hot electronic gas interacting with Cosmic Microwave Back- ground CMB photons passing through Intra Cluster Medium ICM. So far the Isothermal model is used for temperature profiling in the calculation of the inverse Compton effect but based on the recent improved observations from satellites which showed that the hot electronic gas presents a feature called Cooling Flow CF. Temperatures in this model differs towards the edges of the Clusters of Galaxies leading to a change on the Compton parameter in comparison with Isothermal model. In this paper are processed data provided by X-ray satellite Chandra. The X-ray analysis is based on two models for the electron density and temperature profile. A sample of 12 clusters of galaxies are analyzed and by building the temperature profiles using CF model the differences on the Compton parameter are 10-100 in comparison with Isothermal model. Therefore to increase the accuracy of evaluation of the Compton parameter we should take into account the change of the electronic gas tempera- ture change that affect changes in both CMB spectrum and temperature from SZ effect.

  12. Thoracic duct lymphography by subcutaneous contrast agent ...

    African Journals Online (AJOL)

    A second lymphography revealed a collateral thoracic duct that was not detected during the first lymphography. The collateral duct was ligated and chylothorax was resolved after the second surgery. The lymphography applied in this study was minimally-invasive and easily provided images of the thoracic duct in a dog with ...

  13. Case Study to Illustrate the Potential of Conformal Cooling Channels for Hot Stamping Dies Manufactured Using Hybrid Process of Laser Metal Deposition (LMD and Milling

    Directory of Open Access Journals (Sweden)

    Magdalena Cortina

    2018-02-01

    Full Text Available Hot stamping dies include cooling channels to treat the formed sheet. The optimum cooling channels of dies and molds should adapt to the shape and surface of the dies, so that a homogeneous temperature distribution and cooling are guaranteed. Nevertheless, cooling ducts are conventionally manufactured by deep drilling, attaining straight channels unable to follow the geometry of the tool. Laser Metal Deposition (LMD is an additive manufacturing technique capable of fabricating nearly free-form integrated cooling channels and therefore shape the so-called conformal cooling. The present work investigates the design and manufacturing of conformal cooling ducts, which are additively built up on hot work steel and then milled in order to attain the final part. Their mechanical performance and heat transfer capability has been evaluated, both experimentally and by means of thermal simulation. Finally, conformal cooling conduits are evaluated and compared to traditional straight channels. The results show that LMD is a proper technology for the generation of cooling ducts, opening the possibility to produce new geometries on dies and molds and, therefore, new products.

  14. Flow design and simulation of a gas compression system for hydrogen fusion energy production

    Energy Technology Data Exchange (ETDEWEB)

    Avital, E J; Salvatore, E [School of Engineering and Materials Science, Queen Mary University of London, Mile End Rd London E1 4NS (United Kingdom); Munjiza, A [Civil Engineering, University of Split, Livanjska 2100 Split (Croatia); Suponitsky, V; Plant, D; Laberge, M, E-mail: e.avital@qmul.ac.uk [General Fusion Inc.,108-3680 Bonneville Place, Burnaby, BC V3N 4T5 (Canada)

    2017-08-15

    An innovative gas compression system is proposed and computationally researched to achieve a short time response as needed in engineering applications such as hydrogen fusion energy reactors and high speed hammers. The system consists of a reservoir containing high pressure gas connected to a straight tube which in turn is connected to a spherical duct, where at the sphere’s centre plasma resides in the case of a fusion reactor. Diaphragm located inside the straight tube separates the reservoir’s high pressure gas from the rest of the plenum. Once the diaphragm is breached the high pressure gas enters the plenum to drive pistons located on the inner wall of the spherical duct that will eventually end compressing the plasma. Quasi-1D and axisymmetric flow formulations are used to design and analyse the flow dynamics. A spike is designed for the interface between the straight tube and the spherical duct to provide a smooth geometry transition for the flow. Flow simulations show high supersonic flow hitting the end of the spherical duct, generating a return shock wave propagating upstream and raising the pressure above the reservoir pressure as in the hammer wave problem, potentially giving temporary pressure boost to the pistons. Good agreement is revealed between the two flow formulations pointing to the usefulness of the quasi-1D formulation as a rapid solver. Nevertheless, a mild time delay in the axisymmetric flow simulation occurred due to moderate two-dimensionality effects. The compression system is settled down in a few milliseconds for a spherical duct of 0.8 m diameter using Helium gas and a uniform duct cross-section area. Various system geometries are analysed using instantaneous and time history flow plots. (paper)

  15. Flow design and simulation of a gas compression system for hydrogen fusion energy production

    Science.gov (United States)

    Avital, E. J.; Salvatore, E.; Munjiza, A.; Suponitsky, V.; Plant, D.; Laberge, M.

    2017-08-01

    An innovative gas compression system is proposed and computationally researched to achieve a short time response as needed in engineering applications such as hydrogen fusion energy reactors and high speed hammers. The system consists of a reservoir containing high pressure gas connected to a straight tube which in turn is connected to a spherical duct, where at the sphere’s centre plasma resides in the case of a fusion reactor. Diaphragm located inside the straight tube separates the reservoir’s high pressure gas from the rest of the plenum. Once the diaphragm is breached the high pressure gas enters the plenum to drive pistons located on the inner wall of the spherical duct that will eventually end compressing the plasma. Quasi-1D and axisymmetric flow formulations are used to design and analyse the flow dynamics. A spike is designed for the interface between the straight tube and the spherical duct to provide a smooth geometry transition for the flow. Flow simulations show high supersonic flow hitting the end of the spherical duct, generating a return shock wave propagating upstream and raising the pressure above the reservoir pressure as in the hammer wave problem, potentially giving temporary pressure boost to the pistons. Good agreement is revealed between the two flow formulations pointing to the usefulness of the quasi-1D formulation as a rapid solver. Nevertheless, a mild time delay in the axisymmetric flow simulation occurred due to moderate two-dimensionality effects. The compression system is settled down in a few milliseconds for a spherical duct of 0.8 m diameter using Helium gas and a uniform duct cross-section area. Various system geometries are analysed using instantaneous and time history flow plots.

  16. Cystic Duct Closure by Sealing With Bipolar Electrocoagulation

    Science.gov (United States)

    Damgaard, B.; Jorgensen, L. N.; Larsen, S. S.; Kristiansen, V. B.

    2010-01-01

    Background: Cystic duct leakage after cholecystectomy is not uncommon and is a potentially serious complication. The aim of this study was to assess a bipolar sealing system (LigaSure®) for closure of the cystic duct. Methods: The records from consecutive laparoscopic cholecystectomies performed in 2 hospitals with closure of the cystic duct with LigaSure after informed consent were recorded and complications and morbidity registered. The records were compared with those of patients undergoing laparoscopic cholecystectomy with closure of the cystic duct with clips during the same period. Results: During the study period, 218 laparoscopic cholecystectomies were performed; 102 of these were performed with the LigaSure. One patient was excluded due to violation of the protocol. We experienced no cases of cystic duct leakage, but in one patient, bile leakage from the gallbladder bed was observed probably due to a small aberrant duct. Conclusion: The LigaSure system was safe and effective for closure and division of the cystic duct in laparoscopic cholecystectomy. PMID:20412641

  17. Unit vent airflow measurements using a tracer gas technique

    Energy Technology Data Exchange (ETDEWEB)

    Adams, D.G. [Union Electric Company, Fulton, MO (United States); Lagus, P.L. [Lagus Applied Technology, Inc., San Diego, CA (United States); Fleming, K.M. [NCS Corp., Columbus, OH (United States)

    1997-08-01

    An alternative method for assessing flowrates that does not depend on point measurements of air flow velocity is the constant tracer injection technique. In this method one injects a tracer gas at a constant rate into a duct and measures the resulting concentration downstream of the injection point. A simple equation derived from the conservation of mass allows calculation of the flowrate at the point of injection. Flowrate data obtained using both a pitot tube and a flow measuring station were compared with tracer gas flowrate measurements in the unit vent duct at the Callaway Nuclear Station during late 1995 and early 1996. These data are presented and discussed with an eye toward obtaining precise flowrate data for release rate calculations. The advantages and disadvantages of the technique are also described. In those test situations for which many flowrate combinations are required, or in large area ducts, a tracer flowrate determination requires fewer man-hours than does a conventional traverse-based technique and does not require knowledge of the duct area. 6 refs., 10 figs., 6 tabs.

  18. Self-retaining small-looped catheter for narrow bile ducts in high common bile duct obstruction

    International Nuclear Information System (INIS)

    Guenther, R.W.; Daehnert, W.

    1985-01-01

    A new self-retaining catheter was devised for percutaneous drainage of small bile ducts. The device allows safe external drainage without the risk of catheter dislocation even in high bile duct obstruction. The catheter is also suitable for percutaneous nephrostomy in non-dilated pyelocaliceal system. (orig.)

  19. Improved PFB operations: 400-hour turbine test results. [coal combustion products and hot corrosion in gas turbines

    Science.gov (United States)

    Rollbuhler, R. J.; Benford, S. M.; Zellars, G. R.

    1980-01-01

    A pressurized fluidized bed (PFB) coal-burning reactor was used to provide hot effluent gases for operation of a small gas turbine. Preliminary tests determined the optimum operating conditions that would result in minimum bed particle carryover in the combustion gases. Solids were removed from the gases before they could be transported into the test turbine by use of a modified two stage cyclone separator. Design changes and refined operation procedures resulted in a significant decrease in particle carryover, from 2800 to 93 ppm (1.5 to 0.05 grains/std cu ft), with minimal drop in gas temperature and pressure. The achievement of stable burn conditions and low solids loadings made possible a 400 hr test of small superalloy rotor, 15 cm (6 in.) in diameter, operating in the effluent. Blades removed and examined metallographically after 200 hr exhibited accelerated oxidation over most of the blade surface, with subsurface alumina penetration to 20 micron m. After 400 hours, average erosion loss was about 25 micron m (1 mil). Sulfide particles, indicating hot corrosion, were present in depletion zones, and their presence corresponded in general to the areas of adherent solids deposit. Sulfidation appears to be a materials problem equal in importance to erosion.

  20. Hot gas cleaning in power stations by using electron beam technology. Influence on PAH emissions

    International Nuclear Information System (INIS)

    Callen, M.S.; de la Cruz, M.T.; Mastral, A.M.; Murillo, R.; Marinov, S.; Stefanova, M.

    2007-01-01

    The Electron Beam Technology (EBT), proven treatment for SO 2 and NO x removal, is applied to different power stations as a hot gas cleaning system. In this paper, an assessment of this technique installed in a Bulgarian power station on organic emissions is analyzed. The Polycyclic Aromatic Hydrocarbons (PAH) content, not only emitted in the gas phase but also trapped in the solid phase, has been carried out before and after the irradiation. The main aim has been to know whether the EBT affects organic emissions, like PAH, as it happens with inorganic pollutants, like SO 2 and NO x , studying EBT effects from an organic environmental point of view. The PAH quantification was performed by using a very sensitive analytical technique, gas chromatography with mass spectrometry mass spectrometry detection (GC-MS-MS). Results showed that PAH are influenced by the EBT showing a reduction of the most volatile PAH in the gas phase. With regard to the solid by-products obtained after the irradiation, fertilizers, similar PAH concentration to the fly ashes produced when no irradiation is applied were found. These fertilizers were considered like unpolluted soils being adequate for agriculture applications with PAH concentrations below the target value set up by the Dutch government. (author)

  1. Persistent Mullerian Duct Syndrome with Transverse Testicular ...

    African Journals Online (AJOL)

    Eastham JA, McEvoy K, Sullivan R, Chandrasoma P. A case of simultaneous bilateral nonseminomatous testicular tumors in persistent müllerian duct syndrome. J Urol 1992;148:407-8. 8. Shinmura Y, Yokoi T, Tsutsui Y. A case of clear cell adenocarcinoma of the müllerian duct in persistent müllerian duct syndrome: The first ...

  2. Forming Hot Jupiters: Observational Constraints on Gas Giant Formation and migration

    Science.gov (United States)

    Becker, Juliette; Vanderburg, Andrew; Adams, Fred C.; Khain, Tali; Bryan, Marta

    2018-04-01

    Since the first extrasolar planets were detected, the existence of hot Jupiters has challenged prevailing theories of planet formation. The three commonly considered pathways for hot Jupiter formation are in situ formation, runaway accretion in the outer disk followed by disk migration, and tidal migration (occurring after the disk has dissipated). None of these explains the entire observed sample of hot Jupiters, suggesting that different selections of systems form via different pathways. The way forward is to use observational data to constrain the migration pathways of particular classes of systems, and subsequently assemble these results into a coherent picture of hot Jupiter formation. We present constraints on the migratory pathway for one particular type of system: hot Jupiters orbiting cool stars (T< 6200 K). Using the full observational sample, we find that the orbits of most wide planetary companions to hot Jupiters around these cool stars must be well aligned with the orbits of the hot Jupiters and the spins of the host stars. The population of systems containing both a hot Jupiter and an exterior companion around a cool star thus generally exist in roughly coplanar configurations, consistent with the idea that disk-driven migratory mechanisms have assembled most of this class of systems. We then discuss the overall applicability of this result to a wider range of systems and the broader implications on planet formation.

  3. Large scale features of the hot component of the interstellar medium

    International Nuclear Information System (INIS)

    Garmire, G.P.

    1983-01-01

    The interstellar medium contains identifiable hot plasma clouds occupying up to about 35% of the volume of the local galactic disc. The temperature of these clouds is not uniform but ranges from 10 5 up to 4 x 10 6 K. Besides the high temperature which places the emission spectrum in the soft X-ray band, the implied pressure of the hot plasma compared to the cooler gas reveals the importance of this component in determining the motions and evolution of the cooler gas in the disc, as well as providing a source of hot gas which may extend above the galactic disc to form a corona. The author presents data from the A-2 soft X-ray experiment on the HEAO-1 spacecraft concerning the large scale features of this gas. These features are interpreted in terms of the late phases of supernovae expansion, multiple supernovae and the possible creation of a hot halo surrounding the region of the galactic nucleus. (Auth.)

  4. Idiopathic chylopericardium treated by percutaneous thoracic duct embolization after failed surgical thoracic duct ligation

    Energy Technology Data Exchange (ETDEWEB)

    Courtney, Malachi; Ayyagari, Raj R. [Yale School of Medicine, Yale New Haven Hospital, New Haven, CT (United States); Division of Interventional Radiology, Department of Radiology, 789 Howard Avenue, P.O. Box 208042, New Haven, CT (United States)

    2015-06-15

    Chylopericardium rarely occurs in pediatric patients, but when it does it is most often a result of lymphatic injury during cardiothoracic surgery. Primary idiopathic chylopericardium is especially rare, with few cases in the pediatric literature. We report a 10-year-old boy who presented with primary idiopathic chylopericardium after unsuccessful initial treatment with surgical lymphatic ligation and creation of a pericardial window. Following readmission to the hospital for a right-side chylothorax resulting from the effluent from the pericardial window, he had successful treatment by interventional radiology with percutaneous thoracic duct embolization. This case illustrates the utility of thoracic duct embolization as a less-invasive alternative to surgical thoracic duct ligation, or as a salvage procedure when surgical ligation fails. (orig.)

  5. Idiopathic chylopericardium treated by percutaneous thoracic duct embolization after failed surgical thoracic duct ligation

    International Nuclear Information System (INIS)

    Courtney, Malachi; Ayyagari, Raj R.

    2015-01-01

    Chylopericardium rarely occurs in pediatric patients, but when it does it is most often a result of lymphatic injury during cardiothoracic surgery. Primary idiopathic chylopericardium is especially rare, with few cases in the pediatric literature. We report a 10-year-old boy who presented with primary idiopathic chylopericardium after unsuccessful initial treatment with surgical lymphatic ligation and creation of a pericardial window. Following readmission to the hospital for a right-side chylothorax resulting from the effluent from the pericardial window, he had successful treatment by interventional radiology with percutaneous thoracic duct embolization. This case illustrates the utility of thoracic duct embolization as a less-invasive alternative to surgical thoracic duct ligation, or as a salvage procedure when surgical ligation fails. (orig.)

  6. Parotid Duct Repair with Intubation Tube: Technical Note

    Science.gov (United States)

    Öztürk, Muhammed Beşir; Barutca, Seda Asrufoğlu; Keskin, Elif Seda; Atik, Bekir

    2017-01-01

    The parotid duct can be damaged in traumatic injuries and surgical interventions. Early diagnosis and treatment of a duct injury is of great importance because complications such as sialocele and salivary gland fistula may develop if the duct is not surgically repaired. We think the cuff of an intubation tube is an ideal material in parotid duct repair, because of its technical characteristics, easiness of availability, and low-cost. In this paper, we described the use of the cuff cannula of an intubation tube for the diagnosis and treatment of parotid duct laceration, as a low-cost and easy to access material readily available in every operating room. PMID:28713751

  7. Dispersion properties of ducted whistlers, generated by lightning discharge

    Directory of Open Access Journals (Sweden)

    D. L. Pasmanik

    2005-06-01

    Full Text Available Whistler-mode wave propagation in magnetospheric ducts of enhanced cold plasma density is studied. The case of the arbitrary ratio of the duct radius to the whistler wavelength is considered, where the ray-tracing method is not applicable. The set of duct eigenmodes and their spatial structure are analysed and dependencies of eigenmode propagation properties on the duct characteristics are studied. Special attention is paid to the analysis of the group delay time of one-hop propagation of the whistler wave packet along the duct. We found that, in contrast to the case of a wide duct, the group delay time in a rather narrow duct decreases as the eigenmode number increases. The results obtained are suggested for an explanation of some types of multi-component whistler signals.

  8. The hot gas cleaning with multifunctional sorbent technique at 1-20 bar pressure; Kaasujen kuumapuhdistus multifunktionaalisella sorbenttitekniikalla 1-20 bar:n paineessa

    Energy Technology Data Exchange (ETDEWEB)

    Jaanu, K.; Orjala, M.; Paakkinen, K.; Rantanen, J. [VTT Energy, Espoo (Finland)

    1996-12-01

    The aim of the research was to study the simultaneous hot gas cleanup of alkali metals and selected heavy metals under pressure of 1-20 bar using multifunctional sorbent technology, to investigate effects of it on sulfur and nitrogen emissions and to improve the total efficiency of the hot gas cleanup method by reducing the concentrations of harmful components to the level required by the gas turbines. The research has started in the year 1993. The optimization of the test facility at 900 deg C and 20 bar has been accomplished, as targeted. The main topics have been the alkali metals. The main targets of the year 1994 was to concentrate on the research of sorbent effectiveness to remove the impurities like alkalies etc. from the flue gas. Furthermore researches on kinetics and mechanisms were started. The results showed that the developed multifunctional sorbent are highly effective to remove alkalies from the flue gas. Also a mechanism for alkali and lead sorption was proposed. The main topics for 1995 were scheduled to be the completion of the kinetic and mechanical studies and the modelling and the estimation of the data for the pilot scale unit. The kinetic data for one sorbent has been completed and a model for that has also been developed. The measured and calculated results are indicating that the developed multifunctional sorption process is highly effective to remove alkalies and heavy metals such as lead and cadmium from high-temperature combustion gases. The tests are carried out mainly using the pressurized entrained flow reactor of VTT Energy, located in Jyvaeskylae, and in the university of Arizona, where the tests are conducted under atmospheric pressure. Some comparisons of the results might be made with those of Aabo Akademi during the future modelling. 3. The results are applied to purification of the hot gases in boilers, power and process industry. (Abstract Truncated)

  9. Anomalous pancreatic ductal system allowing distal bowel gas with duodenal atresia

    Directory of Open Access Journals (Sweden)

    Shruti Sevak

    2017-11-01

    Bypass of the atretic duodenal segment through an anomalous pancreatic ductal system is a rare anomaly described in the literature in only a handful of cases. This case report highlights the importance of considering duodenal atresia and pancreaticobiliary enteric bypass in the differential diagnosis of neonates presenting with partial duodenal obstruction. On ultrasound, the presence of gas in the biliary tree or pancreatic duct should alert the physician to the possibility of duodenal atresia with congenital pancreaticobiliary duct anomalies that allow for bypass of enteric contents, including air, into more distal bowel, thereby creating a gas pattern aptly described as double bubble with distal gas.

  10. A three dimensional calculation of neutron streaming through ITER tokamak pumping ducts with the Monte Carlo code TRIPOLI-2

    International Nuclear Information System (INIS)

    Bresard, I.; Diop, C.M.; Giancarli, L.; Gervaise, F.

    1991-01-01

    In the frame of the ITER tokamak project, the streaming of neutrons through pumping ducts up to the properly so called pumping system is studied. The gas evacuation device of the ITER plasma consists of a set of vacuum pumps which are located in a room which is outside the main machine building. These pumps receive the exhaust gas through several pumping ducts with a cross section of about four square meters and a length of about ten meters. Although insensitive to the magnetic field, the 14 MeV neutrons from plasma D-T thermonuclear reactions can penetrate in the divertor and reach the room pumping device by propagation through the bent ducts. Different components of this system, such as the bellows, turbomolecular pumps, etc., are irradiated and that raises radiation problems. In this study we determine, by using 3D Monte Carlo transport code TRIPOLI-2, neutron fluxes, dose rates and heatings due to neutrons which have streamed out the plasma through the bent ducts, at several points of the pumping room. Results show the neutron flux attenuation reachs a factor 10 -5 from plasma chamber to the pumping hall; the neutron heatings are estimated to 1.9x10 -3 W/cm 3 in bellow stainless steel at duct entrance, and 8x10 -7 W/cm 3 in the turbopumping stainless steel structure, inside pumping hall. The neutron fluxes obtained will be used to compute gamma source produced by radiative, inelastic process and gamma rays from formed activation products. Then, the knowledge of gamma source will allow to compute gamma dose rate and heating. The dose rates and heatings obtained will contribute to the definition of the ITER pumping system technical options and to establish pumping hall access conditions, also. (orig.)

  11. Solitary intrahepatic bile-duct cyst presenting with Jaundice

    International Nuclear Information System (INIS)

    Park, Jeong Mi; Chun, Ki Sung; Ha, Hyun Kwon; Shinn, Kyung Sub; Bahk, Yong Whee; Kim, Jun Gi

    1989-01-01

    Caroli's disease is an uncommon condition, and characterized by congenital segmental saccular dilatation of intrahepatic bile ducts. A case of Caroli's disease, manifested by only a large communicating cystic dilatation of left intrahepatic bile duct and causing extrinsic pressure over the extrahepatic bile duct, is presented. The patient was 43-year-old housewife, hospitalized because of abdominal distension and severe jaundice. To relieve jaundice and alleviate surgical intervention, percutaneous drainage of the bile-duct cyst preceded surgery

  12. MRI ductography of contrast agent distribution and leakage in normal mouse mammary ducts and ducts with in situ cancer.

    Science.gov (United States)

    Markiewicz, Erica; Fan, Xiaobing; Mustafi, Devkumar; Zamora, Marta; Conzen, Suzanne D; Karczmar, Gregory S

    2017-07-01

    High resolution 3D MRI was used to study contrast agent distribution and leakage in normal mouse mammary glands and glands containing in situ cancer after intra-ductal injection. Five female FVB/N mice (~19weeks old) with no detectable mammary cancer and eight C3(1) SV40 Tag virgin female mice (~15weeks old) with extensive in situ cancer were studied. A 34G, 45° tip Hamilton needle with a 25μL Hamilton syringe was inserted into the tip of the nipple and approximately 15μL of a Gadodiamide was injected slowly over 1min into the nipple and throughout the duct on one side of the inguinal gland. Following injection, the mouse was placed in a 9.4T MRI scanner, and a series of high resolution 3D T1-weighted images was acquired with a temporal resolution of 9.1min to follow contrast agent leakage from the ducts. The first image was acquired at about 12min after injection. Ductal enhancement regions detected in images acquired between 12 and 21min after contrast agent injection was five times smaller in SV40 mouse mammary ducts (pcontrast agent from the SV40 ducts. The contrast agent washout rate measured between 12min and 90min after injection was ~20% faster (p<0.004) in SV40 mammary ducts than in FVB/N mammary ducts. These results may be due to higher permeability of the SV40 ducts, likely due to the presence of in situ cancers. Therefore, increased permeability of ducts may indicate early stage breast cancers. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Method for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

    Science.gov (United States)

    Grindley, Thomas

    1989-01-01

    A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600.degree. to 1800.degree. F. and are partially quenched with water to 1000.degree. to 1200.degree. F. before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime/limestone.

  14. H‑ Opacity and Water Dissociation in the Dayside Atmosphere of the Very Hot Gas Giant WASP-18b

    Science.gov (United States)

    Arcangeli, Jacob; Désert, Jean-Michel; Line, Michael R.; Bean, Jacob L.; Parmentier, Vivien; Stevenson, Kevin B.; Kreidberg, Laura; Fortney, Jonathan J.; Mansfield, Megan; Showman, Adam P.

    2018-03-01

    We present one of the most precise emission spectra of an exoplanet observed so far. We combine five secondary eclipses of the hot Jupiter WASP-18b (T day ∼ 2900 K) that we secured between 1.1 and 1.7 μm with the Wide Field Camera 3 instrument on board the Hubble Space Telescope. Our extracted spectrum (S/N = 50, R ∼ 40) does not exhibit clearly identifiable molecular features but is poorly matched by a blackbody spectrum. We complement this data with previously published Spitzer/Infrared Array Camera observations of this target and interpret the combined spectrum by computing a grid of self-consistent, 1D forward models, varying the composition and energy budget. At these high temperatures, we find there are important contributions to the overall opacity from H‑ ions, as well as the removal of major molecules by thermal dissociation (including water), and thermal ionization of metals. These effects were omitted in previous spectral retrievals for very hot gas giants, and we argue that they must be included to properly interpret the spectra of these objects. We infer a new metallicity and C/O ratio for WASP-18b, and find them well constrained to be solar ([M/H] = ‑0.01 ± 0.35, C/O < 0.85 at 3σ confidence level), unlike previous work but in line with expectations for giant planets. The best-fitting self-consistent temperature–pressure profiles are inverted, resulting in an emission feature at 4.5 μm seen in the Spitzer photometry. These results further strengthen the evidence that the family of very hot gas giant exoplanets commonly exhibit thermal inversions.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. ß-adrenergic regulation of ion transport in pancreatic ducts: Patch-clamp study of isolated rat pancreatic ducts

    DEFF Research Database (Denmark)

    Novak, I

    1998-01-01

    BACKGROUND & AIMS: In the intact pancreas, bicarbonate secretion is thought to be controlled by a number of regulators, including adrenergic agonists. The aim of this study was to investigate the effects of adrenergic agonists on pancreatic ducts, which are the site of bicarbonate secretion....... METHODS: Small intralobular ducts were isolated from rat pancreas and studied in vitro by the whole-cell patch clamp technique. Cell membrane voltages and currents were indicators of cellular ion transport. In some ducts, intracellular Ca2+ activity was measured by fluorescence optical methods. RESULTS...

  17. Noise suppression in duct

    International Nuclear Information System (INIS)

    Ahmed, A.; Barfeh, M.A.G.

    2001-01-01

    In air-conditioning system the noise generated by supply fan is carried by conditioned air through the ductwork. The noise created in ductwork run may be transmission, regenerative and ductborne. Transmission noise is fan noise, regenerative noise is due to turbulence in flow and ductborne noise is the noise radiating from duct to surroundings. Some noise is attenuated in ducts also but if noise level is high then it needs to be attenuated. A simple mitre bend can attenuate-noise. This principle is extended to V and M-shape ducts with inside lining of fibreglass, which gave maximum attenuation of 77 dB and 62 dB respectively corresponding to 8 kHz frequency as compared to mitre, bend giving maximum 18 dB attenuation. Sound level meter measured sound levels with octave band filter and tests were conducted in anechoic room. A V-shape attenuator can be used at fan outlet and high frequency noise can be minimized greatly. (author)

  18. Pressure analysis in ventilation ducts at bituminization facility

    International Nuclear Information System (INIS)

    Kikuchi, Naoki; Iimura, Masato; Takahashi, Yuki; Omori, Eiichi; Yamanouchi, Takamichi

    1997-09-01

    Pressure analysis in cell ventilation ducts at bituminization facility where the fire and explosion accident occured was carried out. This report also describes the results of bench mark calculations for computer code EVENT84 which was used for the accident analysis. The bench mark calculations were performed by comparing the analytical results by EVENT84 code with the experimental data of safety demonstration tests of ventilation system which were carried out by JAERI. We confirmed the applicability of EVENT84 code with the conservative results. The pressure analysis in cell ventilation ducts at bituminization facility were performed by comparing the analytical results of duct pressure by EVENT84 code with the yield stress of destroyed ducts by explosion, in order to estimate the scale of explosion. As a result, we could not explain the damage of ducts quantitatively, but we found the local pressure peaks analytically in downstream ducts where the serious damages were observed. (author)

  19. A study of aerosol deposition by thermophoresis in cylindrical ducts

    International Nuclear Information System (INIS)

    Montassier, N.

    1990-01-01

    The scope of the study was aerosol deposition in cylindrical ducts, and the deposition due to thermophoresis particularly. The theoretical knowledge on this force and the basis of fluid mechanics are first recalled. An experimental study of thermophoretic deposition of particles in laminar flow was carried out in the particular case of uniform particle concentration and gas temperature at the inlet of the cooled tube. When the gas temperature was equilibrated with the wall temperature and thermophoretic particle deposition along the walls had ceased, the deposition efficiency approached a limit. Our experimental results showed that this limiting efficiency was independent on flow. Finally, for the laminar flow regime, a set of simple equations was developed in order to forecast the thermophoretic deposition of particles of any size along a cylindrical tube [fr

  20. Modelling of hot air chamber designs of a continuous flow grain dryer

    DEFF Research Database (Denmark)

    Kjær, Lotte Strange; Poulsen, Mathias; Sørensen, Kim

    2018-01-01

    The pressure loss, flow distribution and temperature distribution of a number of designs of the hot air chamber in a continuous flow grain dryer, were investigated using CFD. The flow in the dryer was considered as steady state, compressible and turbulent. It is essential that the grain...... is uniformly dried as uneven drying can result in damage to the end-product during storage. The original commercial design was modified with new guide vanes at the inlets to reduce the pressure loss and to ensure a uniform flow to the line burner in the hot air chamber. The new guide vane design resulted...... in a 10% reduction in pressure loss and a γ-value of 0.804. Various design changes of the hot air chamber were analysed in terms of pressure loss and temperature distribution with the aim of a temperature variation of 5 K at the outlet ducts. An obstruction design was analysed, which improved mixing...

  1. Duct Remediation Program: Engineered access research and construction

    International Nuclear Information System (INIS)

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

    1992-01-01

    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

  2. Large Eddy Simulation of turbulence induced secondary flows in stationary and rotating straight square ducts

    Science.gov (United States)

    Sudjai, W.; Juntasaro, V.; Juttijudata, V.

    2018-01-01

    The accuracy of predicting turbulence induced secondary flows is crucially important in many industrial applications such as turbine blade internal cooling passages in a gas turbine and fuel rod bundles in a nuclear reactor. A straight square duct is popularly used to reveal the characteristic of turbulence induced secondary flows which consists of two counter rotating vortices distributed in each corner of the duct. For a rotating duct, the flow can be divided into the pressure side and the suction side. The turbulence induced secondary flows are converted to the Coriolis force driven two large circulations with a pair of additional vortices on the pressure wall due to the rotational effect. In this paper, the Large Eddy Simulation (LES) of turbulence induced secondary flows in a straight square duct is performed using the ANSYS FLUENT CFD software. A dynamic kinetic energy subgrid-scale model is used to describe the three-dimensional incompressible turbulent flows in the stationary and the rotating straight square ducts. The Reynolds number based on the friction velocity and the hydraulic diameter is 300 with the various rotation numbers for the rotating cases. The flow is assumed fully developed by imposing the constant pressure gradient in the streamwise direction. For the rotating cases, the rotational axis is placed perpendicular to the streamwise direction. The simulation results on the secondary flows and the turbulent statistics are found to be in good agreement with the available Direct Numerical Simulation (DNS) data. Finally, the details of the Coriolis effects are discussed.

  3. Parotid salivary duct stenosis following caudal maxillectomy.

    Science.gov (United States)

    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.

  4. Magnetic resonance imaging of Muellerian duct anomalies in children

    International Nuclear Information System (INIS)

    Li, Yi; Phelps, Andrew; Zapala, Matthew A.; MacKenzie, John D.; MacKenzie, Tippi C.; Courtier, Jesse

    2016-01-01

    Muellerian duct anomalies encompass a wide variety of disorders resulting from abnormalities in the embryological development of the Muellerian ducts. In the prepubertal pediatric population, Muellerian duct anomalies are often incidental findings on studies obtained for other reasons. The onset of menses can prompt more clinical symptoms. Proper characterization of Muellerian duct anomalies is important because these anomalies can affect the development of gynecological disorders as well as fertility. Muellerian duct anomalies also carry a high association with other congenital anomalies, particularly renal abnormalities. MRI is widely considered the best modality for assessing Muellerian duct anomalies; it provides multiplanar capability, clear anatomical detail and tissue characterization without ionizing radiation. MRI allows for careful description of Muellerian duct anomalies, often leading to classification into the most widely accepted classification system for Muellerian duct anomalies. This system, developed by the American Society of Reproductive Medicine, includes seven subtypes: uterine agenesis/hypoplasia, unicornuate, didelphys, bicornuate, septate, arcuate, and diethylstilbestrol (DES) drug-related uterus. In cases of complex anomalies that defy classification, MRI allows detailed depiction of all components of the anatomical abnormality, allowing for proper management and surgical planning. (orig.)

  5. Models of hot stellar systems

    International Nuclear Information System (INIS)

    Van Albada, T.S.

    1986-01-01

    Elliptical galaxies consist almost entirely of stars. Sites of recent star formation are rare, and most stars are believed to be several billion years old, perhaps as old as the Universe itself (--10/sup 10/ yrs). Stellar motions in ellipticals show a modest amount of circulation about the center of the system, but most support against the force of gravity is provided by random motions; for this reason ellipticals are called 'hot' stellar systems. Spiral galaxies usually also contain an appreciable amount of gas (--10%, mainly atomic hydrogen) and new stars are continually being formed out of this gas, especially in the spiral arms. In contrast to ellipticals, support against gravity in spiral galaxies comes almost entirely from rotation; random motions of the stars with respect to rotation are small. Consequently, spiral galaxies are called 'cold' stellar systems. Other than in hot systems, in cold systems the collective response of stars to variations in the force field is an essential part of the dynamics. The present overview is limited to mathematical models of hot systems. Computational methods are also discussed

  6. Use of Computational Fluid Dynamics for improving freeze-dryers design and process understanding. Part 2: Condenser duct and valve modelling.

    Science.gov (United States)

    Marchisio, Daniele L; Galan, Miquel; Barresi, Antonello A

    2018-05-05

    This manuscript shows how computational models, mainly based on Computational Fluid Dynamics (CFD), can be used to simulate different parts of an industrial freeze-drying equipment and to properly design them; in particular in this part the duct connecting the chamber with the condenser, with its valves, is considered, while the chamber design and its effect on drying kinetics have been investigated in Part 1. Such an approach allows a much deeper process understanding and assessment of the critical aspects of lyophilisation. This methodology will be demonstrated on freeze-drying equipment of different sizes, investigating influence of valve type (butterfly and mushroom) and shape on duct conductance and critical flow conditions. The role of the inlet and boundary conditions considered has been assessed, also by modelling the whole apparatus including chamber and condenser, and the influence of the duct diameter has been discussed; the results show a little dependence of the relationship between critical mass flux and chamber pressure on the duct size. Results concerning the fluid dynamics of a simple disk valve, a profiled butterfly valve and a mushroom valve installed in a medium size horizontal condenser are presented. Also in these cases the maximum allowable flow when sonic flow conditions are reached can be described by a correlation similar to that found valid for empty ducts; for the mushroom valve the parameters are dependent on the valve opening length. The possibility to use the equivalent length concept, and to extend the validity of the results obtained for empty ducts will be also discussed. Finally the presence of the inert gas modifies the conductance of the duct, reducing the maximum flow rate of water that can be removed through it before the flow is choked; this also requires a proper over-sizing of the duct (or duct-butterfly valve system). Copyright © 2018. Published by Elsevier B.V.

  7. Water condensation promotes fungal growth in ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Pasanen, P.; Pasanen, A.-L. (University of Kupopio, Department of Environmental Sciences, Kuopio (Finland)); Jantunen, M. (National Public Health Institute, Kuopio (Finland))

    1993-01-01

    In a subarctic climate the diurnal variation in temperature may cause water condensation in ducts placed in the unheated spaces of a building. In this study, germination time and sporulation of a fungus, Penicillium verrucosum, were studied on dusty, galvanized steel sheet under different moisture conditions at room temperature. The effect of condensed water in a supply air duct on spore amplification was studied in an experimental ventilation set-up. In the field, air temperatures and the dew point temperature of air in the duct were monitored continuously for a week. P. verrucosum germinated on steel surfaces during five-hour incubation of the surface under humid conditions, when the surface has been moist for half an hour, germ tubes appeared within 17 hours. During 24-hour incubation under moist conditions, P. verrucosum produced hyphae and spores. In the experimental set-up the airborne spore counts increased when the air passed through a water-condensing section of the duct. Penicillium was the most abundant fungus sporulated on the moist duct surface. In the field, during humid weather, the surface temperature on the air stream surface decreased to the dew point temperature of the air in the duct. thus water condensation in air ducts may promote fungal growth. (au)

  8. Normal Spiral Galaxies Really Do Have Hot Gas in Their Halos: Chandra Observations of NGC 4013 and NGC 4217.

    Science.gov (United States)

    Strickland, D. K.; Colbert, E. J. M.; Heckman, T. M.; Hoopes, C. G.; Howk, J. C.; Rand, R. J.

    2004-08-01

    Although soft X-ray emission from million degree plasma has long been observed in the halos of starburst galaxies known to have supernova-driven galactic superwinds, X-ray observations have generally failed to detect hot halos around normal spiral galaxies. Indeed, the Milky Way and NGC 891 have historically been the only genuinely "normal" spiral galaxies with unambiguous X-ray halo detections, until now. Here we report on deep observations of NGC 4013 and NGC 4217, two Milky-Way-mass spiral galaxies with star formation rates per unit area similar to the Milky Way and NGC 891, using the Chandra X-ray observatory. Preliminary investigation of the observations clearly show extra-planar diffuse X-ray emission extending several kpc into the halo of NGC 4013. We will present the results of these observations, compare them to the non-detections of hot gas around normal spirals, and relate them to galactic fountain and IGM accretion based models for hot halos. DKS acknowledges funding from NASA through the Smithsonian Astrophysical Observatory. grant G045095X.

  9. Risk factors for central bile duct injury complicating partial liver resection

    NARCIS (Netherlands)

    Boonstra, E. A.; de Boer, M. T.; Sieders, E.; Peeters, P. M. J. G.; de Jong, K. P.; Slooff, M. J. H.; Porte, R. J.

    Background: Bile duct injury is a serious complication following liver resection. Few studies have differentiated between leakage from small peripheral bile ducts and central bile duct injury (CBDI), defined as an injury leading to leakage or stenosis of the common bile duct, common hepatic duct,

  10. Optimum design of the injection duct system of a stenter machine

    Energy Technology Data Exchange (ETDEWEB)

    Juraeva, Makhsuda; Song, Dong Joo [Yeungnam University, Geyongsan (Korea, Republic of); Ryu, Kyung Jin [Ajou Motor College, Boryeong (Korea, Republic of)

    2017-05-15

    Stenter machines are used for drying fabrics in the textile industry and have a heater, injection duct system, and fans inside a chamber. The injection duct system has ducts and air-injecting holes. Plane-type injection duct systems were investigated to obtain uniform airflow at the air-injecting holes. The flow field of the injection duct systems was computed using ANSYS CFX with different heights of the duct end and different shapes for the air-injecting holes. There was a high mass flow rate at the air-injecting holes and high airflow circulation inside both plane-type and mountain-type ducts at the ends. The height of the duct end was varied between 40 mm and 160 mm. The injection duct systems were analyzed with four different shapes of air-injecting holes. The circular and elliptical holes had lower standard deviations of the mass flow rate than other shapes. Relatively uniform mass flow rates were obtained in the plane-type and mountain-type duct systems when the height of the duct end was 40 mm and the shape of the air-injecting holes was circular or elliptical. The developed injection duct systems were improved by obtaining a uniform mass flow rate at the air-injecting holes. A stenter prototype was fabricated with the developed injection duct system to confirm the numerical results. The developed injection duct system had better performance than the original system.

  11. Imaging manifestation of hepatocellular carcinoma with bile duct tumor thrombi

    International Nuclear Information System (INIS)

    Liu Qingyu; Chen Jianyu; Liang Biling; Hu Tao

    2008-01-01

    Objective: To analyze the imaging features of hepatocellular carcinoma(HCC) with bile duct tumor thrombi. Methods: Thirteen patients with bile duct tumor thrombi proved pathologically underwent imaging examination. MR and CT were performed in 3 cases, and 2 cases had CT only and 8 cases had MRI only. Ultrasonography(US) was performed in all 13 patients. The accuracy of bile duct tumor thrombi detection was compared between US, CT and MRI with Fisher test. Results: Liver tumors and bile duct tumor thrombi were demonstrated in all patients on CT or MRI. Presence of intraluminal soft tissue mass was found in four of five cases on CT, and mild enhancement of the intraluminal mass in the arterial phase was noted, dilated bile duct distal to tumor thrombi was detected in all five patients. Eleven Tumor thrombi showed slight low signal intensity on T 1 WI, slight high signal intensity on T 2 WI, and mild to moderate contrast enhancement on the contrast-enhanced MR images. The MRCP findings of tumor thrombi were as follows: interruption, stricture of the bile ducts or irregular filling defect in the bile ducts with dilated intrahepatic ducts, bile duet was abruptly interrupted or showed a 'rat-tail' stricture (n=5); the common bile duct was filled with tumor thrombi, intrahepatic bile duct dilatation and missing common bile duct was noted on MRCP (n=2). Bile duct tumor thrombi were correctly diagnosed in 7 cases on US, and 12 cases on CT or MRI. Six cases were misdiagnosed or miss-diagnosed on US, and 4 cases were misdiagnosed on CT or MRI. There was no significant difference between US and CT/MRI in diagnosis of bile duct tumor thrombi (P=0.270). Conclusion: CT or MR imaging is useful for the diagnosis of HCC with biliary tumor thrombi and for evaluating the extension of thrombi. (authors)

  12. Selective Laser Melting of Hot Gas Turbine Components: Materials, Design and Manufacturing Aspects

    DEFF Research Database (Denmark)

    Goutianos, Stergios

    2017-01-01

    are built additively to nearly net shape. This allows the fabrication of arbitrary complex geometries that cannot be made by conventional manufacturing techniques. However, despite the powerful capabilities of SLM, a number of issues (e.g. part orientation, support structures, internal stresses), have......Selective Laser Melting (SLM) allows the design and manufacturing of novel parts and structures with improved performance e.g. by incorporating complex and more efficient cooling schemes in hot gas turbine parts. In contrast to conventional manufacturing of removing material, with SLM parts...... to be considered in order to manufacture cost-effective and high quality parts at an industrial scale. These issues are discussed in the present work from an engineering point of view with the aim to provide simple quidelines to produce high quality SLM parts....

  13. Investigation of austenitic alloys for advanced heat recovery and hot-gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Swindeman, R.W. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    Materials properties were collected for the design and construction of structural components for use in advanced heat recovery and hot gas cleanup systems. Alloys systems included 9Cr-1Mo-V steel, modified 316 stainless steel, modified type 310 stainless steel, modified 20Cr-25Ni-Nb stainless steel, and modified alloy 800. Experimental work was undertaken to expand the databases for potentially useful alloys. Types of testing included creep, stress-rupture, creep-crack growth, fatigue, and post-exposure short-time tensile tests. Because of the interest in relatively inexpensive alloys for service at 700 C and higher, research emphasis was placed on a modified type 310 stainless steel and a modified 20Cr-25Ni-Nb stainless steel. Both steels were found to have useful strength to 925 C with good weldability and ductility.

  14. Bile duct anastomotic stricture after pediatric living donor liver transplantation.

    Science.gov (United States)

    Chok, Kenneth S H; Chan, See Ching; Chan, Kwong Leung; Sharr, William W; Tam, Paul K H; Fan, Sheung Tat; Lo, Chung Mau

    2012-07-01

    Hepaticojejunostomy is a well-accepted method, whereas duct-to-duct anastomosis is gaining popularity for bile duct reconstruction in pediatric living donor liver transplantation (LDLT). Biliary complications, especially biliary anastomotic stricture (BAS), are not clearly defined. The aim of the present study is to determine the rate of BAS and its associated risk factors. The study included 78 pediatric patients (duct-to-duct anastomosis during LDLT. The median follow-up period for the BAS group and the non-BAS group was 57.8 and 79.5 months, respectively (P = .683). Ten of the patients with BAS required percutaneous transhepatic biliary drainage with or without dilatation for treating the stricture. Multivariable analysis showed that hepatic artery thrombosis and duct-to-duct anastomosis were 2 risk factors associated with BAS. In pediatric LDLT, hepaticojejunostomy is the preferred method for bile duct reconstruction, but more large-scale research needs to be done to reconfirm this result. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. A Comparison of Simulation Capabilities for Ducts

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William A [ORNL; Smith, Matt K [ORNL; Gu, Lixing [Florida Solar Energy Center (FSEC); New, Joshua Ryan [ORNL

    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.

  16. Construction of new tie-in in the Bolivia-Brazil Gas Pipeline (GASBOL) using hot tapping techniques; Derivacao do Gasoduto Bolivia-Brasil com a tecnica de hot-tapping

    Energy Technology Data Exchange (ETDEWEB)

    Frisoli, Caetano [TRANSPETRO - PETROBRAS Transportes, Rio de Janeiro, RJ (Brazil); Frota, Cristiane Souto; Leite Filho, Ismael Casono; Lobao Filho, Jesualdo Pereira; Saavedra, Marcelo Curto [Transportadora Brasileira Gasoduto Bolivia-Brasil, S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    To supply 2,4 MM m3/d of natural gas to Tres Lagoas thermo electric plant, it was necessary to install a new delivery point of 12'' in the 32'' trunk line of Bolivia-Brazil gas pipeline. The most efficient method for executing new delivery points and maintenance repairs in pipelines is using the 'hot-tapping' technique, because there is no need to stop flow and blow down lines. This paper shows the project, specifications, planning and a detailed job execution to support this new city-gate, using a T split sleeve welded in the pipeline, explaining all the activities. Complex and innovative aspects related to the welding and inspection processes, executed in a API 5L X70 pipe at 92 kgf/cm{sup 2}, are also reported. (author)

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

    Science.gov (United States)

    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.

  18. Antipollution system to remove nitrogen dioxide gas

    Science.gov (United States)

    Metzler, A. J.; Slough, J. W.

    1971-01-01

    Gas phase reaction system using anhydrous ammonia removes nitrogen dioxide. System consists of ammonia injection and mixing section, reaction section /reactor/, and scrubber section. All sections are contained in system ducting.

  19. Bile Duct Cancer (Cholangiocarcinoma) Treatment (PDQ®)—Health Professional Version

    Science.gov (United States)

    Bile duct cancer (also called cholangiocarcinoma) can occur in the bile ducts in the liver (intrahepatic) or outside the liver (perihilar or distal extrahepatic). Learn about the types of bile duct cancer, risk factors, clinical features, staging, and treatment for bile duct cancer in this expert-reviewed summary.

  20. Research improvement in Zn-based sorbent for hot gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    X. Bu; Y. Ying; C. Zhang; W. Peng [China Coal Research Institute (CCRI), Beijing (China). Beijing Research Institute of Coal Chemistry

    2005-07-01

    Two Zn-based sorbents, named as L-991 and L-992, used for hot gas desulfurization were developed. The L-992, which was prepared by changing the Zn/Ti ratio and adding a certain proportion of Cu and Mn metal oxide, acquired better performance than L-991. The suitable desulfurisation temperature was 600-700{sup o}C for the L-991 and 600-800{sup o}C for the L-992. The sulfur capacity was about 16 g/100 g and 19-21 g/100 g of L-991 and L-992 respectively. After 17 multi-cycles sulfidation/regeneration tests, the sulfur capacity of the L-991 decreased greatly, while that of the L-992 still remained at 17 g/100 g. Both the sorbents showed orderly crystalline orientation and the particle size did not change. Sulfidation and regeneration tests were done both on lab micro-fixed bed reactor and SMOVEN equipment. During the continuous tests, the H{sub 2}S concentration can be reduced from about 10 g/m{sup 3} to less than 20 mg/m{sup 3}, the H{sub 2}S removal efficiency being {gt} 99%. 14 refs., 9 figs., 2 tabs.

  1. A radiographic study of nasopalatine duct cysts

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Chan Duck; Hwang, Eui Hwan; Lee, Sang Rae [Dept. of Oral Radiology, College of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    1993-02-15

    The purpose of this study was to evaluate the clinical and radiographic features of 35 cases of nasopalatine duct cyst by means of the analysis of periapical and/or occlusal radiograms in 35 persons visited the Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University and Chonbuk National University. The obtained results were as follows: 1. The incidence of nasopalatine duct cysts was higher in males (74.3%) than in females (25.7%). 2. The nasopalatine duct cysts were the most frequently occurred in the 4th decades (34.3%). The 6th and 7th decades (17.1%, 17.1%) were next in order to frequency followed by the 5th decades (14.3%), the 3rd decades (8.6%), the 2nd decades (5.7%), and 8th decades (2.9%). 3. In the signs and symptoms of nasopalatine duct cysts, 25.7% were swelling, 17.1% were swelling and tenderness, 20.0% were swelling and pain, and 37.2% were a symptom. 4. In the shape of nasopalatine duct cysts, 40.0% were round type, 48.6% 11.8% were heart type. 5. In symmetry of the nasopalatine duct cysts, 11.4% were 6-10 mm, 48.6% were 11-20 mm, 25.7% were 21-30 mm, and 14.3% were 31-40 mm. 6. In the periphery of nasopalatine duct cysts, 82.9% were distinct, 17.1% were relatively distinct. 7. In the change of root, 51.5% were intact, 17.1% were root divergence, 20.0% were root resorption, and 11.4% were root divergence and resorption.

  2. A radiographic study of nasopalatine duct cysts

    International Nuclear Information System (INIS)

    Jun, Chan Duck; Hwang, Eui Hwan; Lee, Sang Rae

    1993-01-01

    The purpose of this study was to evaluate the clinical and radiographic features of 35 cases of nasopalatine duct cyst by means of the analysis of periapical and/or occlusal radiograms in 35 persons visited the Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University and Chonbuk National University. The obtained results were as follows: 1. The incidence of nasopalatine duct cysts was higher in males (74.3%) than in females (25.7%). 2. The nasopalatine duct cysts were the most frequently occurred in the 4th decades (34.3%). The 6th and 7th decades (17.1%, 17.1%) were next in order to frequency followed by the 5th decades (14.3%), the 3rd decades (8.6%), the 2nd decades (5.7%), and 8th decades (2.9%). 3. In the signs and symptoms of nasopalatine duct cysts, 25.7% were swelling, 17.1% were swelling and tenderness, 20.0% were swelling and pain, and 37.2% were a symptom. 4. In the shape of nasopalatine duct cysts, 40.0% were round type, 48.6% 11.8% were heart type. 5. In symmetry of the nasopalatine duct cysts, 11.4% were 6-10 mm, 48.6% were 11-20 mm, 25.7% were 21-30 mm, and 14.3% were 31-40 mm. 6. In the periphery of nasopalatine duct cysts, 82.9% were distinct, 17.1% were relatively distinct. 7. In the change of root, 51.5% were intact, 17.1% were root divergence, 20.0% were root resorption, and 11.4% were root divergence and resorption.

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

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Puttagunta, S. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    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.

  4. Simulation of Transcritical CO2 Refrigeration System with Booster Hot Gas Bypass in Tropical Climate

    Science.gov (United States)

    Santosa, I. D. M. C.; Sudirman; Waisnawa, IGNS; Sunu, PW; Temaja, IW

    2018-01-01

    A Simulation computer becomes significant important for performance analysis since there is high cost and time allocation to build an experimental rig, especially for CO2 refrigeration system. Besides, to modify the rig also need additional cos and time. One of computer program simulation that is very eligible to refrigeration system is Engineering Equation System (EES). In term of CO2 refrigeration system, environmental issues becomes priority on the refrigeration system development since the Carbon dioxide (CO2) is natural and clean refrigerant. This study aims is to analysis the EES simulation effectiveness to perform CO2 transcritical refrigeration system with booster hot gas bypass in high outdoor temperature. The research was carried out by theoretical study and numerical analysis of the refrigeration system using the EES program. Data input and simulation validation were obtained from experimental and secondary data. The result showed that the coefficient of performance (COP) decreased gradually with the outdoor temperature variation increasing. The results show the program can calculate the performance of the refrigeration system with quick running time and accurate. So, it will be significant important for the preliminary reference to improve the CO2 refrigeration system design for the hot climate temperature.

  5. Hot spots in Ar and Ne gas puff Z-pinch

    International Nuclear Information System (INIS)

    Krejci, A.; Krousky, E.; Renner, O.

    1989-02-01

    The hot spots in Ar and Ne pinch plasma were investigated. Two pinhole cameras with entrance diameter 13 to 250 μm and flat crystal spectrographs with Si and KAP crystals were used for spatially and spectrally resolved soft X-ray diagnostics. The diameters of Ar (25 to 30 μm) and Ne (40 μm) hot spots were found. From X-ray spectrum of Ar spots the following plasma parameters were determined: T e =1.0 to 1.1 keV and n e =(1.8 to 4.0)x10 27 m -3 . The validity of the Bennett equilibrium for unstable hot spots is discussed. (author). 1 fig., 11 refs

  6. A case of fascioliasis in common bile duct

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Soo Youn; Park, Cheol Min; Chung, Kyu Byung; Lee, Chang Hong; Park, Seung Chul; Choi, Sang Yong; Lim, Han Jong [Korea University College of Medicine, Seoul (Korea, Republic of)

    1989-10-15

    A case of Fascioliasis of common bile duct is confirmed by visualization of adult fluke. Fascioliasis caused by Fasciola hepatica, is common parasitic disease in cattle and sheep. Human is an accidental host. ERCP demonstrated irregular linear conglomerated filling defects in common bile duct. Through surgical intervention, we found adult flukes of F. hepatica and adenomatous hyperplasia of common bile duct.

  7. A case of fascioliasis in common bile duct

    International Nuclear Information System (INIS)

    Ham, Soo Youn; Park, Cheol Min; Chung, Kyu Byung; Lee, Chang Hong; Park, Seung Chul; Choi, Sang Yong; Lim, Han Jong

    1989-01-01

    A case of Fascioliasis of common bile duct is confirmed by visualization of adult fluke. Fascioliasis caused by Fasciola hepatica, is common parasitic disease in cattle and sheep. Human is an accidental host. ERCP demonstrated irregular linear conglomerated filling defects in common bile duct. Through surgical intervention, we found adult flukes of F. hepatica and adenomatous hyperplasia of common bile duct

  8. Treatment Options for Extrahepatic Bile Duct Cancer

    Science.gov (United States)

    ... Treatment Liver Cancer Prevention Liver Cancer Screening Research Bile Duct Cancer (Cholangiocarcinoma) Treatment (PDQ®)–Patient Version Treatment ... are different types of treatment for patients with bile duct cancer. Different types of treatments are available ...

  9. Treatment Option Overview (Extrahepatic Bile Duct Cancer)

    Science.gov (United States)

    ... Treatment Liver Cancer Prevention Liver Cancer Screening Research Bile Duct Cancer (Cholangiocarcinoma) Treatment (PDQ®)–Patient Version Treatment ... are different types of treatment for patients with bile duct cancer. Different types of treatments are available ...

  10. General Information about Extrahepatic Bile Duct Cancer

    Science.gov (United States)

    ... Treatment Liver Cancer Prevention Liver Cancer Screening Research Bile Duct Cancer (Cholangiocarcinoma) Treatment (PDQ®)–Patient Version Treatment ... are different types of treatment for patients with bile duct cancer. Different types of treatments are available ...

  11. A Case of Adenomyomatous Hyperplasia of the Extrahepatic Bile Duct

    Directory of Open Access Journals (Sweden)

    Masakatsu Numata

    2011-08-01

    Full Text Available Adenomyomatous hyperplasia is rarely found in the extrahepatic bile duct. A 54-year-old man was referred to our center with a diagnosis of extrahepatic bile duct stenosis which had been detected by endoscopic retrograde choloangiopancreatography. Abdominal computed tomography revealed thickening of the wall of the middle extrahepatic bile duct, however no malignant cells were detected by cytology. Since bile duct carcinoma could not be ruled out, we performed resection of the extrahepatic duct accompanied by lymph node dissection. Histopathologically, the lesion was diagnosed as adenomyomatous hyperplasia of the extrahepatic bile duct. Present and previously reported cases showed the difficulty of making a diagnosis of adenomyomatous hyperplasia of the extrahepatic bile duct preoperatively or intraoperatively. Therefore, when adenomyomatous hyperplasia is suspected, a radical surgical procedure according to malignant disease may be necessary for definitive diagnosis.

  12. Hepatocellular carcinoma with bile duct involvement : computed Tomographic (CT) findings

    International Nuclear Information System (INIS)

    Lee, Joon Woo; Han, Joon Koo; Kim, Tae Kyoung; And others

    2000-01-01

    To describe the radiologic features of computed tomography (CT) in hepatocellular carcinoma (HCC) with bile duct involvement. We retrospectively analyzed the two phase spiral CT findings of 31 patients in whom HCC with bile duct invasion (n=3D28) or compression (n=3D3), was diagnosed. Eight of these underwent follow up CT after transarterial chemoembolization. We analyzed the size, type, location, enhancement pattern, and lipiodol retention of parenchymal and intraductal masses, as well as their lymphadenopathy. In all patients with bile duct invasion, single or multiple masses were demonstrated in the bile ducts. Intraductal masses showed the same enhancement characteristics as the parenchymal mass (kappa 0.550, p less than 0.001), and were contiguous to this mass. In 14 of 28 patients, intraductal masses filled the peripheral intrahepatic bile ducts and extended to the common bile ducts. In the other 14, the parenchymal mass extended to the area of the porta hepatis and then directly invaded the large ducts. In nine of the 28 patients, there was a hypoattenuated cleft between the intraductal mass and ductal wall. In six, a parenchymal mass was not apparent (n=3D2), or was smaller than 2cm (n=3D4). In five of eight patients (62.5%), follow-up CT after transarterial chemoembolization showed compact or partial lipiodol retention within the intraductal mass. In patients with bile duct compression, perihilar lymph nodes were noted along with the dilated intrahepatic duct but no intra ductal mass was demonstrated in the duct. Hepatocellular carcinomas cause bile duct dilatation either by direct invasion or by extrinsic compression of the bile duct with surrounding enlarged nodes. For the diagnosis of this condition, CT is helpful. (author)

  13. The pipeline transportation of natural gas and the regulation of open access in Brazil: historical perspectives and current; Os dutos de transporte do gas natural e a regulacao do livre acesso no Brasil: perspectivas historicas e atuais

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, Mariana de; Xavier, Yanko Marcius de Alencar [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    The present research, attempting for the economic relevance of the natural gas sector, for the inexistence of a law that disciplines it and, still, for the structural question of the natural gas ducts activity; it analyzes the monopoly of the natural gas ducts activity and the mechanism of competition chosen to brighten up it: the open access. The regulation of the open access and the viability that the insert of this practice has to Brazil nowadays are very important points to be discussed and, in that way, the present research also analyses them. (author)

  14. Self-made metal stent in treatment of nasolacrimal duct obstruction

    International Nuclear Information System (INIS)

    Du Wei; Pang Ruilin; Luo Gang; Gu Jingchuan; Gong Yongxiang

    2003-01-01

    Objective: To evaluate application of self-made metal stent in treatment of nasolacrimal duct obstruction. Methods: In total 15 cases, self-made metal stents made of stainless steel wire were implanted in 18 obstructed nasolacrimal ducts. The lacrimal passages were rinsed and re-canalized followed by antegrade inserting the guide wire from upper dacryon. A dilator was inserted over the guide wire, and then a stent was released from a sheath into the impaired section of nasolacrimal duct. Dacryocystography was performed before and after the interventional procedure. Results: Dacryocystography showed patent nasolacrimal duct after treatment. Epiphora disappeared completely in 11 cases (13 ducts), improved in 4 cases (5 ducts). These cases had been followed up for 61-219 days (167 days in average). Relapse was found in 2 cases (2 ducts) in three months. Those 2 stents were removed by surgical procedure and found occluded by granulation. Conclusion: Interventional placement of the self-made metal stent is a simple, safe, low-cost and effective treatment of the nasolacrimal duct obstruction

  15. Cystic duct remnant mucocele in a liver transplant recipient

    International Nuclear Information System (INIS)

    Ahlawat, Sushil K.; Fishbien, Thomas M.; Haddad, Nadim G.

    2008-01-01

    Cystic duct remnant mucocele is an extremely rare complication of liver transplantation in children. Surgical correction is usually required for cystic duct remnant mucocele when it causes biliary obstruction. We describe a 14-month-old liver transplant recipient who presented with biliary obstruction 1 month after orthotopic liver transplantation with an end-to-end choledochocholedocal biliary anastomosis for hepatoblastoma. US, CT and cholangiography findings were consistent with mucocele of the allograft cystic duct remnant. Surgery was not needed in our patient because the mucocele and biliary obstruction had resolved on repeat imaging most likely due to guidewire manipulation during cholangiography, resulting in opening of the cystic duct remnant orifice and drainage into the common duct. (orig.)

  16. Cystic duct remnant mucocele in a liver transplant recipient

    Energy Technology Data Exchange (ETDEWEB)

    Ahlawat, Sushil K. [Georgetown University Hospital, Department of Medicine, Division of Gastroenterology, Washington, DC (United States); University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ (United States); Fishbien, Thomas M. [Georgetown University Hospital, Department of Medicine, Division of Gastroenterology, Washington, DC (United States); Haddad, Nadim G. [Georgetown University Hospital, Department of Surgery, Division of Transplant Surgery, Washington, DC (United States)

    2008-08-15

    Cystic duct remnant mucocele is an extremely rare complication of liver transplantation in children. Surgical correction is usually required for cystic duct remnant mucocele when it causes biliary obstruction. We describe a 14-month-old liver transplant recipient who presented with biliary obstruction 1 month after orthotopic liver transplantation with an end-to-end choledochocholedocal biliary anastomosis for hepatoblastoma. US, CT and cholangiography findings were consistent with mucocele of the allograft cystic duct remnant. Surgery was not needed in our patient because the mucocele and biliary obstruction had resolved on repeat imaging most likely due to guidewire manipulation during cholangiography, resulting in opening of the cystic duct remnant orifice and drainage into the common duct. (orig.)

  17. (18)O(2) label mechanism of sulfur generation and characterization in properties over mesoporous Sm-based sorbents for hot coal gas desulfurization.

    Science.gov (United States)

    Liu, B S; Wan, Z Y; Wang, F; Zhan, Y P; Tian, M; Cheung, A S C

    2014-02-28

    Using a sol-gel method, SmMeOx/MCM-41 or SBA-15 (Me=Fe, Co and Zn) and corresponding unsupported sorbents were prepared. The desulfurization performance of these sorbents was evaluated over a fixed-bed reactor and the effects of reaction temperature, feed and sorbent composition on desulfurization performance were studied. Samarium-based sorbents used to remove H2S from hot coal gas were reported for the first time. The results of successive sulfidation/regeneration cycles revealed that SmFeO3/SBA-15 sorbent was suitable for desulfurization of hot coal gas in the chemical industry. The formation of elemental sulfur during both sulfidation and regeneration processes depended strongly on the catalytic action of Sm2O2S species, which was confirmed for the first time via high sensitive time of flight mass spectrometer (TOF-MS) using 6%vol(18)O2/Ar regeneration gas and can reduce markedly procedural complexity. The sorbents were characterized using N2-adsorption, high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), temperature-programmed reduction of H2 (H2-TPR), thermogravimetry (TG) and time-of-flight mass spectrometry (TOF-MS) techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Bowing-reactivity trends in EBR-II assuming zero-swelling ducts

    International Nuclear Information System (INIS)

    Meneghetti, D.

    1994-01-01

    Predicted trends of duct-bowing reactivities for the Experimental Breeder Reactor II (EBR-II) are correlated with predicted row-wise duct deflections assuming use of idealized zero-void-swelling subassembly ducts. These assume no irradiation induced swellings of ducts but include estimates of the effects of irradiation-creep relaxation of thermally induced bowing stresses. The results illustrate the manners in which at-power creeps may affect subsequent duct deflections at zero power and thereby the trends of the bowing component of a subsequent power reactivity decrement

  19. [Bile duct lesions in laparoscopic cholecystectomy].

    Science.gov (United States)

    Siewert, J R; Ungeheuer, A; Feussner, H

    1994-09-01

    Laparoscopic cholecystectomy is both resulting in a slightly higher incidence of biliary lesions and a change of prevalence of the type of lesions. Damage to the biliary system occurs in 4 different types: The most severe case is the lesion with a structural defect of the hepatic or common bile duct with (IVa) or without (IVb) vascular injury. Tangential lesions without structural loss of the duct should be denominated as type III (IIIa with additional lesion to the vessels, type IIIb without). Type II comprehends late strictures without obvious intraoperative trauma to the duct. Type I includes immediate biliary fistulae of usually good prognosis. The increasing prevalence of structural defects of the bile ducts appears to be a peculiarity of laparoscopic cholecystectomy necessitating highly demanding operative repair. In the majority of cases, hepatico-jejunostomy or even intraparenchymatous anastomoses are required. Adaptation of well proven principles of open surgery is the best prevention of biliary lesions in laparoscopic cholecystectomy as well as the readiness to convert early to the open procedure.

  20. In-duct removal of mercury from coal-fired power plant flue gas by activated carbon: assessment of entrained flow versus wall surface contributions

    Energy Technology Data Exchange (ETDEWEB)

    Scala, F.; Chirone, R.; Lancia, A. [CNR, Naples (Italy). Institute for Research on Combustion

    2008-12-15

    In-duct mercury capture efficiency by activated carbon from coal-combustion flue gas was investigated. To this end, elemental mercury capture experiments were conducted at 100 C in a purposely designed 65-mm ID labscale pyrex apparatus operated as an entrained flow reactor. Gas residence times were varied between 0.7 and 2.0 s. Commercial-powdered activated carbon was continuously injected in the reactor and both mercury concentration and carbon elutriation rate were followed at the outlet. Transient mercury concentration profiles at the outlet showed that steady-state conditions were reached in a time interval of 15-20 min, much longer than the gas residence time in the reactor. Results indicate that the influence of the walls is non-negligible in determining the residence time of fine carbon particles in the adsorption zone, because of surface deposition and/or the establishment of a fluid-dynamic boundary layer near the walls. Total mercury capture efficiencies of 20-50% were obtained with carbon injection rates in the range 0.07-0.25 g/min. However, only a fraction of this capture was attributable to free-flowing carbon particles, a significant contribution coming from activated carbon staying near the reactor walls. Entrained bed experiments at lab-scale conditions are probably not properly representative of full-scale conditions, where the influence of wall interactions is lower. Moreover, previously reported entrained flow lab-scale mercury capture data should be reconsidered by taking into account the influence of particle-wall interactions.

  1. Ultrasound appearance of chronic mammary duct ectasia

    Energy Technology Data Exchange (ETDEWEB)

    Duchesne, N. [Ottawa Hospital, Dept. of Radiology, Ottawa, Ontario (Canada)]. E-mail: nathalie_duchesne_22@yahoo.ca; Skolnik, S. [Univ. of Toronto, Dept. of Family Medicine, Toronto, Ontario (Canada); Bilmer, S. [Ottawa Hospital, Dept. of Radiology, Ottawa, Ontario (Canada)

    2005-12-15

    Mammary duct ectasia (MDE), also called periductal mastitis, mammary dysplasia, or plasma cell mastitis, is a benign condition of the mammary gland first described by Haagensen in 1951. The etiology of MDE is unknown and its pathogenesis still controversial; the periductal inflammation could be either the cause or the result of dilated damaged ducts. The process is usually bilateral and asymptomatic, with only a small percentage of patients presenting with symptoms that may include long course of tumour formation, usually subareolar breast lumps, nipple discharge, nipple retraction, mastalgia, and mammary abscess or fistulas. Mammographic presentation of MDE is well known; its features include periductal calcification, benign intraductal calcification, and retroareolar duct dilatation. The periductal calcification results from dystrophic calcification and forms calcified rings or very dense, oval, elongated calcifications, each with a central lucency representing the dilated duct. Intraductal calcifications of duct ectasia represent inspissated intraductal material and are typically of uniform high density, often needle-like, and occasionally branching. Occasionally, there are no mammographic findings, and the diagnosis must rely on sonographic features. Appearance of MDE on ultrasonography (US) depends on the stage of the disease and the contents of the dilated ducts. The acute presentation has been demonstrated in the literature more often than has its chronic counterpart. In the former, duct content can vary from anechoic to isoechoic with surrounding fatty tissue. In chronic MDE, episodes of inflammation are longer. This tends to result in secretions that have a more solid, cheesy texture, partly due to cholesterol crystals, foam cells, and inflammatory cells. For both types of MDE, the appearance can mimic high-grade ductal carcinoma in situ (DCIS) on US. In this essay, 2 chronic MDE cases are presented and their US appearance discussed. Our goal is to explore

  2. Ultrasound appearance of chronic mammary duct ectasia

    International Nuclear Information System (INIS)

    Duchesne, N.; Skolnik, S.; Bilmer, S.

    2005-01-01

    Mammary duct ectasia (MDE), also called periductal mastitis, mammary dysplasia, or plasma cell mastitis, is a benign condition of the mammary gland first described by Haagensen in 1951. The etiology of MDE is unknown and its pathogenesis still controversial; the periductal inflammation could be either the cause or the result of dilated damaged ducts. The process is usually bilateral and asymptomatic, with only a small percentage of patients presenting with symptoms that may include long course of tumour formation, usually subareolar breast lumps, nipple discharge, nipple retraction, mastalgia, and mammary abscess or fistulas. Mammographic presentation of MDE is well known; its features include periductal calcification, benign intraductal calcification, and retroareolar duct dilatation. The periductal calcification results from dystrophic calcification and forms calcified rings or very dense, oval, elongated calcifications, each with a central lucency representing the dilated duct. Intraductal calcifications of duct ectasia represent inspissated intraductal material and are typically of uniform high density, often needle-like, and occasionally branching. Occasionally, there are no mammographic findings, and the diagnosis must rely on sonographic features. Appearance of MDE on ultrasonography (US) depends on the stage of the disease and the contents of the dilated ducts. The acute presentation has been demonstrated in the literature more often than has its chronic counterpart. In the former, duct content can vary from anechoic to isoechoic with surrounding fatty tissue. In chronic MDE, episodes of inflammation are longer. This tends to result in secretions that have a more solid, cheesy texture, partly due to cholesterol crystals, foam cells, and inflammatory cells. For both types of MDE, the appearance can mimic high-grade ductal carcinoma in situ (DCIS) on US. In this essay, 2 chronic MDE cases are presented and their US appearance discussed. Our goal is to explore

  3. HVAC; Heating, Ventilation, Air Conditioning - Aerosol Duct Sealant

    Science.gov (United States)

    2016-09-01

    material was applied. Annual energy and cost savings were predicted based on a typical weather year for each site. The installation of the duct...Balance reports; Visible dust streaks on duct work, ceilings near supply diffusers, or electrical boxes; Comfort complaints Specific Leakage...energy consumption , depending on the HVAC system type and the location of the ducts that were sealed. The cost effectiveness of the technology is

  4. Atmospheric pressure flow reactor: Gas phase chemical kinetics under tropospheric conditions without wall effects

    Science.gov (United States)

    Koontz, Steven L. (Inventor); Davis, Dennis D. (Inventor)

    1991-01-01

    A flow reactor for simulating the interaction in the troposphere is set forth. A first reactant mixed with a carrier gas is delivered from a pump and flows through a duct having louvers therein. The louvers straighten out the flow, reduce turbulence and provide laminar flow discharge from the duct. A second reactant delivered from a source through a pump is input into the flowing stream, the second reactant being diffused through a plurality of small diffusion tubes to avoid disturbing the laminar flow. The commingled first and second reactants in the carrier gas are then directed along an elongated duct where the walls are spaced away from the flow of reactants to avoid wall interference, disturbance or turbulence arising from the walls. A probe connected with a measuring device can be inserted through various sampling ports in the second duct to complete measurements of the first and second reactants and the product of their reaction at selected XYZ locations relative to the flowing system.

  5. Desulfurized gas production from vertical kiln pyrolysis

    Science.gov (United States)

    Harris, Harry A.; Jones, Jr., John B.

    1978-05-30

    A gas, formed as a product of a pyrolysis of oil shale, is passed through hot, retorted shale (containing at least partially decomposed calcium or magnesium carbonate) to essentially eliminate sulfur contaminants in the gas. Specifically, a single chambered pyrolysis vessel, having a pyrolysis zone and a retorted shale gas into the bottom of the retorted shale zone and cleaned product gas is withdrawn as hot product gas near the top of such zone.

  6. A non-local computational boundary condition for duct acoustics

    Science.gov (United States)

    Zorumski, William E.; Watson, Willie R.; Hodge, Steve L.

    1994-01-01

    A non-local boundary condition is formulated for acoustic waves in ducts without flow. The ducts are two dimensional with constant area, but with variable impedance wall lining. Extension of the formulation to three dimensional and variable area ducts is straightforward in principle, but requires significantly more computation. The boundary condition simulates a nonreflecting wave field in an infinite duct. It is implemented by a constant matrix operator which is applied at the boundary of the computational domain. An efficient computational solution scheme is developed which allows calculations for high frequencies and long duct lengths. This computational solution utilizes the boundary condition to limit the computational space while preserving the radiation boundary condition. The boundary condition is tested for several sources. It is demonstrated that the boundary condition can be applied close to the sound sources, rendering the computational domain small. Computational solutions with the new non-local boundary condition are shown to be consistent with the known solutions for nonreflecting wavefields in an infinite uniform duct.

  7. On Computations of Duct Acoustics with Near Cut-Off Frequency

    Science.gov (United States)

    Dong, Thomas Z.; Povinelli, Louis A.

    1997-01-01

    The cut-off is a unique feature associated with duct acoustics due to the presence of duct walls. A study of this cut-off effect on the computations of duct acoustics is performed in the present work. The results show that the computation of duct acoustic modes near cut-off requires higher numerical resolutions than others to avoid being numerically cut off. Duct acoustic problems in Category 2 are solved by the DRP finite difference scheme with the selective artificial damping method and results are presented and compared to reference solutions.

  8. Assessment of corrosion in the flue gas cleaning system using on-line monitoring

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Vendelbo Nielsen, Lars; Berggreen Petersen, Michael

    2015-01-01

    Amager unit 1 is a 350 MW multifuel suspension-fired plant commissioned in 2009 to fire biomass (straw and wood pellets). Increasing corrosion problems in the flue gas cleaning system were observed in the gas-gas preheater (GAFO), the booster fan and flue gas ducts. Chlorine containing corrosion ...

  9. Hot gas metallicity and the history of supernova activity in elliptical galaxies

    International Nuclear Information System (INIS)

    Loewenstein, M.; Mathews, W.G.

    1991-01-01

    Calculations of the dynamical evolution of the hot interstellar medium (ISM) in a massive elliptical galaxy are described, with a variety of past variations of the SN rate being assumed. The investigation focuses on iron enrichment in the ISM. The equivalent widths of the 6.7-keV iron line are calculated as a function of redshift and of galactic projected radius. The present-day interstellar gas in elliptical galaxies contains a fossil record of past SN activity that can be determined from measurements of iron line equivalent widths at several projected radii in the galaxy. It is proposed that the ISM iron abundance is likely to be quite inhomogeneous. The hydrogen-free ejecta of type Ia SN also result in pronounced ISM abundance inhomogeneities that probably eventually cool and move in pressure equilibrium with the local ISM flow velocity. The 6.7-keV iron line emission is greater if the iron is confined to ionized regions of pure iron. 25 refs

  10. Pre-cometary ice composition from hot core chemistry.

    Science.gov (United States)

    Tornow, Carmen; Kührt, Ekkehard; Motschmann, Uwe

    2005-10-01

    Pre-cometary ice located around star-forming regions contains molecules that are pre-biotic compounds or pre-biotic precursors. Molecular line surveys of hot cores provide information on the composition of the ice since it sublimates near these sites. We have combined a hydrostatic hot core model with a complex network of chemical reactions to calculate the time-dependent abundances of molecules, ions, and radicals. The model considers the interaction between the ice and gas phase. It is applied to the Orion hot core where high-mass star formation occurs, and to the solar-mass binary protostar system IRAS 16293-2422. Our calculations show that at the end of the hot core phase both star-forming sites produce the same prebiotic CN-bearing molecules. However, in the Orion hot core these molecules are formed in larger abundances. A comparison of the calculated values with the abundances derived from the observed line data requires a chemically unprocessed molecular cloud as the initial state of hot core evolution. Thus, it appears that these objects are formed at a much younger cloud stage than previously thought. This implies that the ice phase of the young clouds does not contain CN-bearing molecules in large abundances before the hot core has been formed. The pre-biotic molecules synthesized in hot cores cause a chemical enrichment in the gas phase and in the pre-cometary ice. This enrichment is thought to be an important extraterrestrial aspect of the formation of life on Earth and elsewhere.

  11. HOT GAS LINES IN T TAURI STARS

    International Nuclear Information System (INIS)

    Ardila, David R.; Herczeg, Gregory J.; Gregory, Scott G.; Hillenbrand, Lynne A.; Ingleby, Laura; Bergin, Edwin; Bethell, Thomas; Calvet, Nuria; France, Kevin; Brown, Alexander; Edwards, Suzan; Johns-Krull, Christopher; Linsky, Jeffrey L.; Yang, Hao; Valenti, Jeff A.; Abgrall, Hervé; Alexander, Richard D.; Brown, Joanna M.; Espaillat, Catherine; Hussain, Gaitee

    2013-01-01

    For Classical T Tauri Stars (CTTSs), the resonance doublets of N V, Si IV, and C IV, as well as the He II 1640 Å line, trace hot gas flows and act as diagnostics of the accretion process. In this paper we assemble a large high-resolution, high-sensitivity data set of these lines in CTTSs and Weak T Tauri Stars (WTTSs). The sample comprises 35 stars: 1 Herbig Ae star, 28 CTTSs, and 6 WTTSs. We find that the C IV, Si IV, and N V lines in CTTSs all have similar shapes. We decompose the C IV and He II lines into broad and narrow Gaussian components (BC and NC). The most common (50%) C IV line morphology in CTTSs is that of a low-velocity NC together with a redshifted BC. For CTTSs, a strong BC is the result of the accretion process. The contribution fraction of the NC to the C IV line flux in CTTSs increases with accretion rate, from ∼20% to up to ∼80%. The velocity centroids of the BCs and NCs are such that V BC ∼> 4 V NC , consistent with the predictions of the accretion shock model, in at most 12 out of 22 CTTSs. We do not find evidence of the post-shock becoming buried in the stellar photosphere due to the pressure of the accretion flow. The He II CTTSs lines are generally symmetric and narrow, with FWHM and redshifts comparable to those of WTTSs. They are less redshifted than the CTTSs C IV lines, by ∼10 km s –1 . The amount of flux in the BC of the He II line is small compared to that of the C IV line, and we show that this is consistent with models of the pre-shock column emission. Overall, the observations are consistent with the presence of multiple accretion columns with different densities or with accretion models that predict a slow-moving, low-density region in the periphery of the accretion column. For HN Tau A and RW Aur A, most of the C IV line is blueshifted suggesting that the C IV emission is produced by shocks within outflow jets. In our sample, the Herbig Ae star DX Cha is the only object for which we find a P-Cygni profile in the C IV

  12. Identification and treatment of variation of extrahepatic bile duct in laparoscopic cholecystectomy

    Directory of Open Access Journals (Sweden)

    PENG Lei

    2015-10-01

    Full Text Available ObjectiveTo investigate the identification and treatment of variation of extrahepatic bile duct in laparoscopic cholecystectomy (LC, and to reduce the occurrence of bile duct injury. MethodsThis study included 60 patients who received LC in the People′s Hospital of Caidian District in Wuhan and had structural variation of extrahepatic bile duct found during the operation from January 2012 to January 2014. The clinical data were retrospectively analyzed, and the intraoperative and postoperative conditions were summarized. ResultsDuring operation, cystic duct variation was found in 32 cases, abnormal position of the point where the cystic duct joins the extrahepatic bile duct in 20 cases, the cystic duct and the common hepatic duct having the common wall before joining the common bile duct in 2 cases, aberrant bile duct in the gallbladder bed in 2 cases, and accessory hepatic duct in 4 cases. Fifty-one patients (85% successfully underwent LC; 9 patients (15% were converted to open surgery. All patients finished surgery successfully. There were 2 cases of postoperative complications; one patient developed residual stones in the bile duct, and bile leakage occurred in the other patient at one week after LC, who recovered after reoperation. All patients were cured and discharged, without severe complications such as intraperitoneal hemorrhage, infection, and intestinal injury. ConclusionIdentifying the structural variation of extrahepatic bile duct, dissecting the Calot′s triangle meticulously, and determining the type of variation of extrahepatic bile duct play important roles in LC and significantly reduce the incidence of bile duct injury.

  13. Experiment with CFD in the power industry

    Energy Technology Data Exchange (ETDEWEB)

    Somogyi, M.; Davidson, T.E. [HRL Technology Pty. Ltd., Mulgrave, Vic. (Australia)

    1997-07-01

    Several recent examples of successful applications of CFD modelling are described to demonstrate the benefits that can be realised when this technique is used to optimise processes of fluid flow, heat transfer, combustion and particle tracking. Examples include: velocity distribution in inlet ducts of precipitators; mixing of hot and cold gas streams; flow and temperature transients in a cooling pond; and simulation of gas combustors. 11 figs.

  14. Effect of wall thickness and helium cooling channels on duct magnetohydrodynamic flows

    International Nuclear Information System (INIS)

    He, Qingyun; Feng, Jingchao; Chen, Hongli

    2016-01-01

    Highlights: • MHD flows in ducts of different wall thickness compared with wall uniform. • Study of velocity, pressure distribution in ducts MHD flows with single pass of helium cooling channels. • Comparison of three types of dual helium cooling channels and acquisition of an option for minimum pressure drop. • A single short duct MHD flow in blanket without FCI has been simulated for pressure gradient analysis. - Abstract: The concept of dual coolant liquid metal (LM) blanket has been proposed in different countries to demonstrate the technical feasibility of DEMO reactor. In the system, helium gas and PbLi eutectic, separated by structure grid, are used to cool main structure materials and to be self-cooled, respectively. The non-uniform wall thickness of structure materials gives rise to wall non-homogeneous conductance ratio. It will lead to electric current distribution changes, resulting in significant changes in the velocity distribution and pressure drop of magnetohydrodynamic (MHD) flows. In order to investigate the effect of helium channels on MHD flows, different methods of numerical simulations cases are carried out including the cases of different wall thicknesses, single pass of helium cooling channels, and three types of dual helium cooling channels. The results showed that helium tubes are able to affect the velocity distribution in the boundary layer by forming wave sharp which transfers from Hartmann boundary layer to the core area. In addition, the potential profile and pressure drop in the cases have been compared to these in the case of walls without cooling channel, and the pressure gradient of a simplified single short duct MHD flow in blanket shows small waver along the central axis in the helium channel position.

  15. Effect of wall thickness and helium cooling channels on duct magnetohydrodynamic flows

    Energy Technology Data Exchange (ETDEWEB)

    He, Qingyun; Feng, Jingchao; Chen, Hongli, E-mail: hlchen1@ustc.edu.cn

    2016-02-15

    Highlights: • MHD flows in ducts of different wall thickness compared with wall uniform. • Study of velocity, pressure distribution in ducts MHD flows with single pass of helium cooling channels. • Comparison of three types of dual helium cooling channels and acquisition of an option for minimum pressure drop. • A single short duct MHD flow in blanket without FCI has been simulated for pressure gradient analysis. - Abstract: The concept of dual coolant liquid metal (LM) blanket has been proposed in different countries to demonstrate the technical feasibility of DEMO reactor. In the system, helium gas and PbLi eutectic, separated by structure grid, are used to cool main structure materials and to be self-cooled, respectively. The non-uniform wall thickness of structure materials gives rise to wall non-homogeneous conductance ratio. It will lead to electric current distribution changes, resulting in significant changes in the velocity distribution and pressure drop of magnetohydrodynamic (MHD) flows. In order to investigate the effect of helium channels on MHD flows, different methods of numerical simulations cases are carried out including the cases of different wall thicknesses, single pass of helium cooling channels, and three types of dual helium cooling channels. The results showed that helium tubes are able to affect the velocity distribution in the boundary layer by forming wave sharp which transfers from Hartmann boundary layer to the core area. In addition, the potential profile and pressure drop in the cases have been compared to these in the case of walls without cooling channel, and the pressure gradient of a simplified single short duct MHD flow in blanket shows small waver along the central axis in the helium channel position.

  16. Bile duct obstruction

    Science.gov (United States)

    ... Tumors that have spread to the biliary system Liver and bile duct worms (flukes) The risk factors include: History of ... Increased bilirubin level Increased alkaline phosphatase level Increased liver enzymes The ... CT scan Endoscopic retrograde cholangiopancreatography ( ...

  17. Pancreatic-duct-lavage cytology in candidates for surgical resection of branch-duct intraductal papillary mucinous neoplasm of the pancreas: should the International Consensus Guidelines be revised?

    Science.gov (United States)

    Sai, Jin Kan; Suyama, Masafumi; Kubokawa, Yoshihiro; Watanabe, Sumio; Maehara, Tadayuki

    2009-03-01

    The International Consensus Guidelines are helpful for the management of branch-duct intraductal papillary mucinous neoplasms (IPMNs), because they allow us to exclude malignancy. However, it is not possible to predict malignancy with certainty, and further preoperative differentiation between benign and malignant IPMNs is required to avoid the false-positive results. To examine the usefulness of pancreatic-duct-lavage cytology by using an originally designed double-lumen catheter for discriminating benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines. Pancreatic-duct-lavage cytology was investigated in 24 patients with branch-duct IPMNs who underwent surgical resection based on the International Consensus Guidelines, namely, they either had intramural nodules or the ectatic branch duct was >30 mm in diameter. Single-center retrospective study. Academic medical center. The sensitivity and specificity of pancreatic-duct-lavage cytology for discriminating benign from malignant IPMNs. More than 30 mL of pancreatic-duct-lavage fluid was obtained from each patient, and there were no patients with noninformative results. The sensitivity, specificity, positive predictive value, and negative predictive value of the cytologic diagnosis were 78%, 93%, 88%, and 88%, respectively. Single-center and small number of patients. Pancreatic-duct-lavage cytology can improve differentiation between benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines.

  18. Gas cogeneration system in Sapporo Therme

    Energy Technology Data Exchange (ETDEWEB)

    Kanematsu, Michihiko

    1988-06-01

    Sapporo Therme is a multi-purpose resort including a hot-water jumbo swimming pool having an area of about 130,000m/sup 2/ and a circumference of 800 m, 13 additional swimming pools with additional sizes, a hot-water slider, 16 types of saunas, an artificial sunbathing system, an athletic system, a restaurant, a cinema, tennis courts, and other outdoor facilities. Sapporo Therme uses a cogeneration system consisting of using LP gas(95% or more propane gas) to drive a 1,200 PS gas engine and supply motive power and lightening. At the same time, the cogeneration system collects gas engine waste heat and combines this heat with that from hot-water and steam boilers to supply hot water to swimming pools, roads, and room heaters. The ratio of waste heat collection rate to power generation efficiency is about 5.0. Sapporo Therme is thus the optimal facilities for cogeneration. (1 figs, 3 photos)

  19. Percutaneous treatment of benign bile duct strictures

    Energy Technology Data Exchange (ETDEWEB)

    Koecher, Martin [Department of Radiology, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic)]. E-mail: martin.kocher@seznam.cz; Cerna, Marie [Department of Radiology, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Havlik, Roman [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Kral, Vladimir [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Gryga, Adolf [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic); Duda, Miloslav [Department of Surgery, University Hospital, I.P.Pavlova 6, 775 20 Olomouc (Czech Republic)

    2007-05-15

    Purpose: To evaluate long-term results of treatment of benign bile duct strictures. Materials and methods: From February 1994 to November 2005, 21 patients (9 men, 12 women) with median age of 50.6 years (range 27-77 years) were indicated to percutaneous treatment of benign bile duct stricture. Stricture of hepatic ducts junction resulting from thermic injury during laparoscopic cholecystectomy was indication for treatment in one patient, stricture of hepaticojejunostomy was indication for treatment in all other patients. Clinical symptoms (obstructive jaundice, anicteric cholestasis, cholangitis or biliary cirrhosis) have appeared from 3 months to 12 years after surgery. Results: Initial internal/external biliary drainage was successful in 20 patients out of 21. These 20 patients after successful initial drainage were treated by balloon dilatation and long-term internal/external drainage. Sixteen patients were symptoms free during the follow-up. The relapse of clinical symptoms has appeared in four patients 9, 12, 14 and 24 months after treatment. One year primary clinical success rate of treatment for benign bile duct stricture was 94%. Additional two patients are symptoms free after redilatation (15 and 45 months). One patient is still in treatment, one patient died during secondary treatment period without interrelation with biliary intervention. The secondary clinical success rate is 100%. Conclusion: Benign bile duct strictures of hepatic ducts junction or biliary-enteric anastomosis are difficult to treat surgically and endoscopically inaccessible. Percutaneous treatment by balloon dilatation and long-term internal/external drainage is feasible in the majority of these patients. It is minimally invasive, safe and effective.

  20. Fluid flow in a spiral microfluidic duct

    Science.gov (United States)

    Harding, Brendan; Stokes, Yvonne

    2018-04-01

    We consider the steady, pressure driven flow of a viscous fluid through a microfluidic device having the geometry of a planar spiral duct with a slowly varying curvature and height smaller than width. For this problem, it is convenient to express the Navier-Stokes equations in terms of a non-orthogonal coordinate system. Then, after applying appropriate scalings, the leading order equations admit a relatively simple solution in the central region of the duct cross section. First-order corrections with respect to the duct curvature and aspect ratio parameters are also obtained for this region. Additional correction terms are needed to ensure that no slip and no penetration conditions are satisfied on the side walls. Our solutions allow for a top wall shape that varies with respect to the radial coordinate which allows us to study the flow in a variety of cross-sectional shapes, including trapezoidal-shaped ducts that have been studied experimentally. At leading order, the flow is found to depend on the local height and slope of the top wall within the central region. The solutions are compared with numerical approximations of a classical Dean flow and are found to be in good agreement for a small duct aspect ratio and a slowly varying and small curvature. We conclude that the slowly varying curvature typical of spiral microfluidic devices has a negligible impact on the flow in the sense that locally the flow does not differ significantly from the classical Dean flow through a duct having the same curvature.

  1. The Canadian residential duct and chimney survey

    Energy Technology Data Exchange (ETDEWEB)

    Fugler, D.

    2003-12-01

    A study was conducted in 1989 to better understand the thermal performance of ducts and chimneys in houses. The objective was to address the problems associated with insufficient airflow and backdrafting of combustion gases resulting from malfunctioning fans, furnaces and fireplaces. The Duct Test Rig was used to measure and recorded airflows and heat losses in a variety of ducts and chimneys in a representative mix of houses in Vancouver, Kelowna, Winnipeg, Calgary, Toronto, London, Montreal, Quebec City, Halifax, Fredericton and Ottawa. Bath, kitchen, clothes dryer and central vacuum exhaust fans were tested to determine how performance is affected by fan age, accumulations of dust, grease, bugs and installation methods. Results indicate that there is no statistical difference between axial or centrifugal fans. The greatest problem appeared to be with low flows, high leakage rates, and poor conditions of bathroom fans. Many kitchen fans were found to be blocked at the inlet by cooking grease. The exhaust flows depended greatly on the condition of the backdraft damper. Dryer exhaust airflow was typically less than the 75 L/s specified by manufacturers, but even old dryers performed relatively well. All types of chimneys were tested for different positive hood pressures, airflow lost through leakage, and thermal characteristics. Airflow was found to vary depending on the type and area of the flue and the presence of a cap. For heating systems, the low duct efficiency was due mostly to duct leakage, radiation losses and restrictive ducts and registers. The findings of this testing program are still valid today. 3 tabs.

  2. Experiments and calculations on neutron streaming through bent ducts

    Energy Technology Data Exchange (ETDEWEB)

    Kloosterman, J.L.; Hoogenboom, J.E. (Delft Univ. of Technology (Netherlands). Interfaculty Reactor Inst.); Zsolnay, E.M.

    1993-07-01

    Neutron spectra in a cylindrical straight duct and in bent ducts with angles of 30deg, 60deg and 90deg have been measured by the multiple foil activation and thermoluminescence dosimetry methods. Two-dimensional discrete ordinates and three-dimensional Monte Carlo calculations are executed, and the results are compared with the measurements. The flow rate at the duct entrance calculated by the DOT3.5 code is underestimated by approximately 30 %, due to a conversion of the core and reflector geometry from XY to RZ geometry. The fast neutron flux in the ducts is underestimated by 20 % by the MORSE-SGC/S code due to a too coarse angular mesh of the source, which does not properly represent the actual angular distribution of the fast flux, which is highly peaked forwardly into the ducts. The thermal neutron flux was over-estimated by the Monte Carlo calculation. A method is proposed to calculate the angular distribution of the flow rate at the duct entrance and to calculate the source strength and the angular distribution of the flow rate at the entrance of the second leg of the duct. The results are compared with those of the transport calculations. Generally, the agreement is quite satisfactory. (author).

  3. Pancreaticobiliary duct changes of periampullary carcinomas: Quantitative analysis at MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Dong Sheng, E-mail: victoryhope@163.com [Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China); Department of Radiology, No.4 West China Teaching Hospital of Sichuan University, Chengdu 610041 (China); Chen, Wei Xia, E-mail: wxchen25@126.com [Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China); Wang, Xiao Dong, E-mail: tyfs03yz@163.com [Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China); Acharya, Riwaz, E-mail: riwaz007@hotmail.com [Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China); Jiang, Xing Hua, E-mail: 13881865517@163.com [Department of Pathology, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China)

    2012-09-15

    Purpose: To quantitatively analyse the pancreaticobiliary duct changes of periampullary carcinomas with volumetric interpolated breath-hold examination (VIBE) and true fast imaging with steady-state precession (true FISP) sequence, and investigate the value of these findings in differentiation and preoperative evaluation. Materials and methods: Magnetic resonance (MR) images of 71 cases of periampullary carcinomas (34 cases of pancreatic head carcinoma, 16 cases of intrapancreatic bile duct carcinoma and 21 cases of ampullary carcinoma) confirmed histopathologically were analysed. The maximum diameter of the common bile duct (CBD) and main pancreatic duct (MPD), dilated pancreaticobiliary duct angle and the distance from the end of the proximal dilated pancreaticobiliary duct to the major papilla were measured. Analysis of variance and the Chi-squared test were performed. Results: These findings showed significant differences among the three subtypes: the distance from the end of proximal dilated pancreaticobiliary duct to the major papilla and pancreaticobiliary duct angle. The distance and the pancreaticobiliary duct angle were least for ampullary carcinoma among the three subtypes. The percentage of dilated CBD was 94.1%, 93.8%, and 100% for pancreatic head carcinoma, intrapancreatic bile duct carcinoma and ampullary carcinoma, respectively. And that for the dilated MPD was 58.8%, 43.8%, and 42.9%, respectively. Conclusion: Quantitative analysis of the pancreaticobiliary ductal system can provide accurate and objective assessment of the pancreaticobiliary duct changes. Although benefit in differential diagnosis is limited, these findings are valuable in preoperative evaluation for both radical resection and palliative surgery.

  4. Persistent Mullerian Duct Syndrome (PMDS With Large Intraabdominal Seminoma

    Directory of Open Access Journals (Sweden)

    Della Harigovind

    2017-07-01

    Full Text Available Persistent Mullerian Duct Syndrome, a form of male pseudohermaphroditism is characterized by the presence of the Mullerian duct derivatives in an otherwise phenotypically as well as genotypically normal male. We report a case of large intra abdominal seminoma in a male patient with cryptorchidism, along with persistence of Mullerian duct derivatives (uterus.

  5. Parotid duct laceration repair in two horses : case report

    Directory of Open Access Journals (Sweden)

    A. Olivier

    1998-07-01

    Full Text Available Repair of parotid duct lacerations in 2 horses is described using intraluminal silastic tubing as a stent. The duct was lacerated traumatically at the facial vessel notch (incisura vasorum facialium in the 1st horse, and iatrogenically after removal of an intraluminal sialolith after development of infection within the duct in the 2nd horse. In both cases, a silastic tube was passed retrograde into the duct via the salivary papilla, past the wound until the end lay rostroventral to the parotid salivary gland. The severed salivary ducts and the wounds were sutured. The external portion of the silastic tube was sutured to the skin and the tube left in place. Recovery in the 1st case was uneventful. In the 2nd case a salivary duct/cutaneous fistula formed at a wound distant from the sutured wound, which healed spontaneously. This technique differs from a similar described technique in that the stent tube exits the oral cavity and is attached to the outer skin surface.

  6. In Situ Apparatus to Study Gas-Metal Reactions and Wettability at High Temperatures for Hot-Dip Galvanizing Applications

    Science.gov (United States)

    Koltsov, A.; Cornu, M.-J.; Scheid, J.

    2018-02-01

    The understanding of gas-metal reactions and related surface wettability at high temperatures is often limited due to the lack of in situ surface characterization. Ex situ transfers at low temperature between annealing furnace, wettability device, and analytical tools induce noticeable changes of surface composition distinct from the reality of the phenomena.Therefore, a high temperature wettability device was designed in order to allow in situ sample surface characterization by x-rays photoelectron spectroscopy after gas/metal and liquid metal/solid metal surface reactions. Such airless characterization rules out any contamination and oxidation of surfaces and reveals their real composition after heat treatment and chemical reaction. The device consists of two connected reactors, respectively, dedicated to annealing treatments and wettability measurements. Heat treatments are performed in an infrared lamp furnace in a well-controlled atmosphere conditions designed to reproduce gas-metal reactions occurring during the industrial recrystallization annealing of steels. Wetting experiments are carried out in dispensed drop configuration with the precise control of the deposited droplets kinetic energies. The spreading of drops is followed by a high-speed CCD video camera at 500-2000 frames/s in order to reach information at very low contact time. First trials have started to simulate phenomena occurring during recrystallization annealing and hot-dip galvanizing on polished pure Fe and FeAl8 wt.% samples. The results demonstrate real surface chemistry of steel samples after annealing when they are put in contact with liquid zinc alloy bath during hot-dip galvanizing. The wetting results are compared to literature data and coupled with the characterization of interfacial layers by FEG-Auger. It is fair to conclude that the results show the real interest of such in situ experimental setup for interfacial chemistry studies.

  7. Liver and Bile Duct Cancer—Patient Version

    Science.gov (United States)

    Liver cancer includes hepatocellular carcinoma and bile duct cancer (cholangiocarcinoma). Risk factors for HCC include chronic infection with hepatitis B or C and cirrhosis of the liver. Start here to find information on liver and bile duct cancer treatment, causes and prevention, screening, research, and statistics.

  8. Submandibular duct sialolithiasis an unusual presentation

    International Nuclear Information System (INIS)

    Shafi, M.; Jafferi, S.; Jafferi, S.

    2006-01-01

    Multiple calculi in a submandibular gland duct is an uncommon occurrence. One such case occurring in a young boy of 25 years is reported here where thirteen very small stones of 1-3 mm of maximum diameter were lined up in the Wharton's duct in such a way that they were difficult to appreciate on inspection and palpation. Successful exploration was done in two steps. (author)

  9. THE HOT INTERSTELLAR MEDIUM OF THE INTERACTING GALAXY NGC 4490

    International Nuclear Information System (INIS)

    Richings, A. J.; Fabbiano, G.; Wang Junfeng; Roberts, T. P.

    2010-01-01

    We present an analysis of the hot interstellar medium (ISM) in the spiral galaxy NGC 4490, which is interacting with the irregular galaxy NGC 4485, using ∼100 ks of Chandra ACIS-S observations. The high angular resolution of Chandra enables us to remove discrete sources and perform spatially resolved spectroscopy for the star-forming regions and associated outflows, allowing us to look at how the physical properties of the hot ISM such as temperature, hydrogen column density, and metal abundances vary throughout these galaxies. We find temperatures of >0.41 keV and 0.85 +0.59 -0.12 keV, electron densities of >1.87η -1/2 x 10 -3 cm -3 and 0.21 +0.03 -0.04 η -1/2 x 10 -3 cm -3 , and hot gas masses of >1.1η 1/2 x 10 7 M sun and ∼3.7η 1/2 x 10 7 M sun in the plane and halo of NGC 4490, respectively, where η is the filling factor of the hot gas. The abundance ratios of Ne, Mg, and Si with respect to Fe are found to be consistent with those predicted by theoretical models of type II supernovae (SNe). The thermal energy in the hot ISM is ∼5% of the total mechanical energy input from SNe, so it is likely that the hot ISM has been enriched and heated by type II SNe. The X-ray emission is anticorrelated with the Hα and mid-infrared emission, suggesting that the hot gas is bounded by filaments of cooler ionized hydrogen mixed with warm dust.

  10. Reinforcement of the bio-gas conversion from pyrolysis of wheat straw by hot caustic pre-extraction.

    Science.gov (United States)

    Zhang, Lilong; Chen, Keli; He, Liang; Peng, Lincai

    2018-01-01

    Pyrolysis has attracted growing interest as a versatile means to convert biomass into valuable products. Wheat straw has been considered to be a promising biomass resource due to its low price and easy availability. However, most of the products obtained from wheat straw pyrolysis are usually of low quality. Hot soda extraction has the advantage of selective dissolution of lignin whilst retaining the carbohydrates. This can selectively convert biomass into high-quality desired products and suppress the formation of undesirable products. The aim of this study was to investigate the pyrolysis properties of wheat straw under different hot caustic pretreatment conditions. Compared with the untreated straw, a greater amount of gas was released and fewer residues were retained in the extracted wheat straw, which was caused by an increase in porosity. When the NaOH loading was 14%, the average pore size of the extracted straw increased by 12% and the cumulative pore volume increased by 157% compared with the untreated straw. The extracted straw obtained from the 14% NaOH extraction was clearly selective for pyrolysis products. On one hand, many lignin pyrolysis products disappeared, and only four main lignin-unit-pyrolysis products were retained. On the other hand, polysaccharide pyrolysis products were enriched. Both propanone and furfural have outstanding peak intensities that could account for approximately 30% of the total pyrolysis products. However, with the excessive addition of NaOH (i.e. > 22% w/w) during pretreatment, the conversion of bio-gas products decreased. Thermogravimetric and low-temperature nitrogen-adsorption analysis showed that the pore structure had been seriously destroyed, leading to the closing of the release paths of the bio-gas and thus increasing the re-polymerisation of small bio-gas molecules. After suitable extraction (14% NaOH loading extraction), a considerable amount (25%) of the soluble components dissolved out of the straw. This

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

    Energy Technology Data Exchange (ETDEWEB)

    Beal, D. [BA-PIRC, Cocoa, FL (United States); McIlvaine, J. [BA-PIRC, Cocoa, FL (United States); Fonorow, K. [BA-PIRC, Cocoa, FL (United States); Martin, E. [BA-PIRC, Cocoa, FL (United States)

    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.

  12. Evaluation of PEGIT duct connection system

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-08-01

    Most air duct system components are assembled in the field and are mechanically fastened by sheet metal screws (for sheet metal-to-sheet metal) or by drawbands (for flex duct-to-sheet metal). Air sealing is separate from this mechanical fastening and is usually achieved using tape or mastic products after mechanical fastening. Field observations have shown that mechanical fastening rarely meets code or manufacturers requirements and that sealing procedures are similarly inconsistent. To address these problems, Proctor Engineering Group (PEG) is developing a system of joining ducts (called PEGIT) that combines the mechanical fastening and sealing into a single self-contained procedure. The PEGIT system uses a shaped flexible seal between specially designed sheet metal duct fittings to both seal and fasten duct sections together. Figure 1 shows the inner duct fitting complete with rubber seal. This seal provides the air seal for the completed fitting and is shaped to allow the inner and outer fittings to slide together, and then to lock the fittings in place. The illustration in Figure 2 shows the approximate cross section of the rubber seal that shows how the seal has a lip that is angled backwards. This angled lip allows the joint to be pushed together by folding flat but then its long axis makes it stiff in the pulling apart direction. This study was undertaken to assist PEG in some of the design aspects of this system and to test the performance of the PEGIT system. This study was carried out in three phases. The initial phase evaluated the performance of a preliminary seal design for the PEGIT system. After the first phase, the seal was redesigned and this new seal was evaluated in the second phase of testing. The third phase performed more detailed testing of the second seal design to optimize the production tolerances of the sheet metal fittings. This report summarizes our findings from the first two phases and provides details about the third phase of testing.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. High accuracy acoustic relative humidity measurement in duct flow with air.

    Science.gov (United States)

    van Schaik, Wilhelm; Grooten, Mart; Wernaart, Twan; van der Geld, Cees

    2010-01-01

    An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0-12 m/s with an error of ± 0.13 m/s, temperature 0-100 °C with an error of ± 0.07 °C and relative humidity 0-100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

  15. Squamous metaplasia of lactiferous ducts (SMOLD)

    International Nuclear Information System (INIS)

    Lo, G.; Dessauvagie, B.; Sterrett, G.; Bourke, A.G.

    2012-01-01

    The aim of this review is to illustrate the mammographic and sonographic appearances of squamous metaplasia of the lactiferous ducts (SMOLD) and to discuss the disease processes of this uncommon breast disease, which shows a strong correlation with smoking. The most common mammographic appearance is of a retro-areolar asymmetrical density. Ultrasonography of the symptomatic breast typically shows a retro-areolar, predominately medial, ill-defined, hypoechoic lesion with either abscess or sinus/fistula formation. Duct dilatation and continuity with lactiferous ducts is commonly seen. Increased vascularity is occasionally seen on colour Doppler ultrasound. Pathology tissue confirmation is always required and this can be by histology of a core biopsy or excision specimen, or fine-needle aspiration (FNA) cytology. Occasionally smears of an associated abundant nipple or sinus discharge may be of value.

  16. Ducted wind turbine optimization : A numerical approach

    NARCIS (Netherlands)

    Dighe, V.V.; De Oliveira Andrade, G.L.; van Bussel, G.J.W.

    2017-01-01

    The practice of ducting wind turbines has shown a beneficial effect on the overall performance, when compared to an open turbine of the same rotor diameter1. However, an optimization study specifically for ducted wind turbines (DWT’s) is missing or incomplete. This work focuses on a numerical

  17. Mixing and NO(x) Emission Calculations of Confined Reacting Jet Flows in a Cylindrical Duct

    Science.gov (United States)

    Holdeman, James D. (Technical Monitor); Oechsle, Victor L.

    2003-01-01

    Rapid mixing of cold lateral jets with hot cross-stream flows in confined configurations is of practical interest in gas turbine combustors as it strongly affects combustor exit temperature quality, and gaseous emissions in for example rich-lean combustion. It is therefore important to further improve our fundamental understanding of the important processes of dilution jet mixing especially when the injected jet mass flow rate exceeds that of the cross-stream. The results reported in this report describe some of the main flow characteristics which develop in the mixing process in a cylindrical duct. A 3-dimensional tool has been used to predict the mixing flow field characteristics and NOx emission in a quench section of an RQL combustor, Eighteen configurations have been analyzed in a circular geometry in a fully reacting environment simulating the operating condition of an actual RQL gas turbine combustion liner. The evaluation matrix was constructed by varying three parameters: 1) jet-to-mainstream momentum-flux ratio (J), 2) orifice shape or orifice aspect ratio, and 3) slot slant angle. The results indicate that the mixing flow field significantly varies with the value of the jet penetration and subsequently, slanting elongated slots generally improve the mixing uniformity at high J conditions. Round orifices produce more uniform mixing and low NO(x) emissions at low J due to the strong and adequate jet penetration. No significant correlation was found between the NO(x) production rates and the mixing deviation parameters, however, strong correlation was found between NO(x) formation and jet penetration. In the computational results, most of the NO(x) formation occurred behind the orifice starting at the orifice wake region. Additional NO(x) is formed upstream of the orifice in certain configurations with high J conditions due to the upstream recirculation.

  18. Transient thermal-hydraulic simulations of direct cycle gas cooled reactors

    International Nuclear Information System (INIS)

    Tauveron, Nicolas; Saez, Manuel; Marchand, Muriel; Chataing, Thierry; Geffraye, Genevieve; Bassi, Christophe

    2005-01-01

    This work concerns the design and safety analysis of gas cooled reactors. The CATHARE code is used to test the design and safety of two different concepts, a High Temperature Gas Reactor concept (HTGR) and a Gas Fast Reactor concept (GFR). Relative to the HTGR concept, three transient simulations are performed and described in this paper: loss of electrical load without turbo-machine trip, 10 in. cold duct break, 10 in. break in cold duct combined with a tube rupture of a cooling exchanger. A second step consists in modelling a GFR concept. A nominal steady state situation at a power of 600 MW is obtained and first transient simulations are carried out to study decay heat removal situations after primary loop depressurisation. The turbo-machine contribution is discussed and can offer a help or an alternative to 'active' heat extraction systems

  19. Flow restriction of multicontrolled natural gas; Restritor de fluxo de gas natural microcontrolado

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Lauro C.; Reis, Antonio M.; Maldonado, Waldemar; Suzuqui, Moises [Universidade para o Desenvolvimento do Estado e da Regiao do Pantanal (UNIDERP), Campo Grande, MS (Brazil). Nucleo de Energia, Automacao e Controle; Scucuglia, Jose W.; Cortez, Marco A.A. [Universidade para o Desenvolvimento do Estado e da Regiao do Pantanal (UNIDERP), Campo Grande, MS (Brazil). Curso de Engenharia Eletrica; Teixeira, Marcelo C.M. [UNESP, Ilha Solteira, SP (Brazil). Faculdade de Engenharia Eletrica; Carrasco, Benjamim N. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    One of the specific cases of control in the operation of natural gas distribution is of the automatic restriction of the outflow due the violations of standards of draining of the natural gas in the ducts. With the objective to get a device of low cost, with national technology and high technological value aggregate, developed an electronic, microcontrolled, programmable device, and of low cost, that will function connected the sensors and valves of flow control, of form to monitor in real time the outflow of draining of the natural gas in the respective ducts and to restrict of automatic form the outflow, that necessary or always convenient. The developed hardware was conceived using micro controllers of high performance with capacity of reading of sensors of pressure, temperature and measurers of outflow. Had to a serial communication and the storage in memory of mass with 264 capacity of Kbytes is possible the pertinent visualization of graphs and reports to the behavior of the outflow and performance of the system. An internal RTC - Real Clock Teams, added to the hardware a clock and a calendar for acquisition of data in the schedule defined, as well as the possibility of unloading of the data through the telephonic line, using one embedded modem. (author)

  20. Common bile duct cancer with massive necrosis mimicking choledochal dilatation on CT

    International Nuclear Information System (INIS)

    Miyake, H.; Matsumoto, S.; Ueda, S.; Maeda, T.; Aikawa, H.; Mori, H.

    1991-01-01

    Carcinomas of the common bile duct are usually seen as dilatation of the bile duct proximal to a solid mass on CT. In the case reported here, the common bile duct cancer itself mimicked dilated common bile duct on CT because of massive necrosis. In a case of simulating dilated common bile duct on CT, and discrepancy between CT and ultrasonography or endoscopic retrograde cholangiopancreatography, a common bile duct cancer with massive necrosis should be included in the differential diagnosis. (orig.)

  1. Method and apparatus for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

    Science.gov (United States)

    Grindley, T.

    1988-04-05

    A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier is described. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600 to 1800 F and are partially quenched with water to 1000 to 1200 F before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime /limestone. 1 fig.

  2. Design requirement on KALIMER control rod assembly duct

    International Nuclear Information System (INIS)

    Hwang, W.; Kang, H. Y.; Nam, C.; Kim, J. O.; Kim, Y. J.

    1998-03-01

    This document establishes the design guidelines which are needs for designing the control rod assembly duct of the KALIMER as design requirements. it describes control rod assembly duct of the KALIMER and its requirements that includes functional requirements, performance requirements, interfacing systems, design limits and strength requirements, seismic requirements, structural requirements, environmental requirements, reliability and safety requirements, standard and codes, QA programs, and other requirements. The control rod system consists of three parts, which are drive mechanism, drive-line, and absorber bundle. This report deals with the absorber bundle and its outer duct only because the others are beyond the scope of fuel system design. The guidelines for design requirements intend to be used for an improved design of the control rod assembly duct of the KALIMER. (author). 19 refs

  3. Design requirement on KALIMER control rod assembly duct

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, W.; Kang, H. Y.; Nam, C.; Kim, J. O.; Kim, Y. J

    1998-03-01

    This document establishes the design guidelines which are needs for designing the control rod assembly duct of the KALIMER as design requirements. it describes control rod assembly duct of the KALIMER and its requirements that includes functional requirements, performance requirements, interfacing systems, design limits and strength requirements, seismic requirements, structural requirements, environmental requirements, reliability and safety requirements, standard and codes, QA programs, and other requirements. The control rod system consists of three parts, which are drive mechanism, drive-line, and absorber bundle. This report deals with the absorber bundle and its outer duct only because the others are beyond the scope of fuel system design. The guidelines for design requirements intend to be used for an improved design of the control rod assembly duct of the KALIMER. (author). 19 refs.

  4. Hot corrosion behavior of Ni-Cr-W-C alloys in impure helium gas

    International Nuclear Information System (INIS)

    Ohmura, Taizo; Sahira, Kensho; Sakonooka, Akihiko; Yonezawa, Noboru

    1976-01-01

    Influence of the minor alloy constituents such as Al, Mn and Si on the hot corrosion behavior of Ni-20Cr-20W-0.07C alloy was studied in 99.995% helium gas at 1000 0 C, comparing with that behavior of commercial Ni-base superalloys (Hastelloy X and Inconel 617). The low oxidizing potential in the impure helium gas usually causes selective oxidation of these elements and the growth of oxide whiskers on the surface of specimen at elevated temperature. The intergranular attack was caused by selective oxidation of Al, Si and Mn. The spalling of oxide film was restrained by addition of Mn and Si, providing tough spinel type oxide film on the surface and 'Keyes' on the oxide-matrix interface respectively. The amount and the morphology of the oxide whiskers depended on Si and Mn content. More than 0.29% of Si content without Mn always caused the growth of rather thinner whiskers with smooth surface, and the whiskers analyzed by electron diffraction patterns and EPMA to be Cr 2 O 3 containing Si. Mn addition changed the whiskers to thicker ones of spinel type oxide (MnCr 2 O 1 ) with rough surface. On the basis of these results, the optimum content of Al, Mn and Si to minimize the growth of whiskers, the intergranular attack and the spalling of oxide film was discussed. (auth.)

  5. Hollow-duct radiation delivery system investigation

    Directory of Open Access Journals (Sweden)

    Kramer D.

    2013-05-01

    Full Text Available Investigation of hollow-duct structure for high-power laser-diode-array radiation delivery into the end-pumped large-aperture gain media is reported. A ray tracing method has been used to evaluate the performance of the structure designed for maximum transmission efficiency and output beam profile homogeneity. Variable hollow-duct lengths as well as emanating angles of laser-diode-array have been taken into account.

  6. Prediction of fan assisted flow in a duct/pipe network

    International Nuclear Information System (INIS)

    Quraishi, M.S.

    1996-01-01

    The commonly used fan+duct model is usually based on a table generated by matching the fan and system characteristic curves with the applied pressure drop across the fan+duct/pipe network and using linear or polynomial interpolation for intermediate values. However, this empirical approach can only handle a single system configuration for each table. If this approach is replaced by an algebraic formulation a general and flexible model can be developed. The algebraic model will be able to account for failure of resistances in the duct/pipe system as well as the failure of duct/pipe at an intermediate location. This paper presents the development of an algebraic model for fan+duct/pipe systems. (author)

  7. An incidence study on thyroglossal duct cysts in adults

    International Nuclear Information System (INIS)

    Kurt, A.; Ortug, C.; Aydar, Y.; Ortug, G.

    2007-01-01

    To investigate the incidence of the asymptomatic thyroglossal duct anomalies and to review the literature and make comments on the significance of this condition. A total of 80 cadavers were dissected in the present study. This study was carried out during 2005, where the cadavers were randomly included from the criminal laboratories of the Ministry of Justice, Republic of Turkey in Istanbul. None of the cadavers had laryngeal and cervical injuries resulting from a trauma or the cause of their death. The examined cadavers included 59 men and 21 females, and their ages were ranged from 35-80 years old. The larynges were removed and fixed in 10% formalin and then dissected. The sections were examined using surgical SMZ 10 Nikon stereomicroscope. We evaluated the presence, localization and diameter of the cysts with regard to age and sex of the cadavers. We observed a total of 12 different localization of thyroglossal ducts and cysts among the 80 dissected cadavers. Ten of these ducts cysts were found in males with an age range of 35-68 years and 2 female cadavers aged 45-65 years. In 6 cases, the thyroglossal ducts and cysts were located in the left of the midline of the neck, while 3 cases were from the right of the midline, and the remaining was located on the midline of the neck. In all cases, thryoglossal ducts and cysts were complete and restricted to the infrahyoid region: all of them had connection with the hyoid bone, but not with the perichondrium of the cartilage. In addition, the thyroglossal ducts have connection with the left lobe of the thyroid glands in 3 cases, one case in the right lobe, and 2 cases with the isthmus of the thyroid gland. Finally in 5 cases thyroglossal ducts were complete and had well developed cysts. Thyroglossal duct remnants are one of the most often seen congenital asymptomatic masses of the neck region (7%). The presence of these duct remnants may lead to abnormal phonation and epithelial carcinomas. Therefore, correlation of

  8. Endoscopic stenting in bile duct cancer increases liver volume.

    Science.gov (United States)

    Lee, Chang Hun; Kim, Seong Hun; Kim, In Hee; Kim, Sang Wook; Lee, Soo Teik; Kim, Dae Ghon; Yang, Jae Do; Yu, Hee Chul; Cho, Baik Hwan; Lee, Seung Ok

    2014-09-01

    Objective evaluation tools for assessing the effectiveness of stenting in palliative treatment of malignant biliary obstruction are not satisfactory. Effects of biliary stenting on liver volume change have never been studied. We aimed to use volumetry to analyze liver volume changes after endoscopic stenting in bile duct cancer according to the location and number of stents. Retrospective review. University hospital. Patients with a diagnosis of hilar or distal bile duct cancer and who underwent biliary metal stenting. ERCP with self-expandable metal stent placement. Liver volume change after biliary stenting and its comparison according to the location (hilar vs distal common bile duct) and number (hilar bilateral vs hilar unilateral). There were 60 patients; 31 were treated for hilar bile duct cancer (13 for bilateral stent and 18 for unilateral stent) and 29 for distal bile duct cancer. Overall mean follow-up duration was 11.7 ± 4.9 weeks. Liver volume increased 17.4 ± 24.1%. The rate of liver growth was rapid during the early period from 4 to 8 weeks. Stenting in hilar bile duct cancer tended to increase liver volume more than distal biliary stents (22.5% vs 11.9%, P = .091). In hilar bile duct cancer, unilateral and bilateral stents showed similar liver volume increases (20.1% and 25.8%, respectively; P = .512). Single center, retrospective. Biliary stenting markedly increased liver volume in both hilar and distal bile duct cancer. Our data suggest that liver volume assessment could be a useful tool for evaluating stent efficacy. Copyright © 2014 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  9. Reconstruction of Bile Duct Injury and Defect with the Round Ligament.

    Science.gov (United States)

    Dokmak, Safi; Aussilhou, Béatrice; Ragot, Emilia; Tantardini, Camille; Cauchy, François; Ponsot, Philippe; Belghiti, Jacques; Sauvanet, Alain; Soubrane, Olivier

    2017-09-01

    Lateral injury of the bile duct can occur after cholecystectomy, bile duct dissection, or exploration. If direct repair is not possible, conversion to bilioenteric anastomosis can be needed with the risk of long-term bile duct infections and associated complications. We developed a new surgical technique which consist of reconstructing the bile duct with the round ligament. The vascularized round ligament is completely mobilized until its origin and used for lateral reconstruction of the bile duct to cover the defect. T tube was inserted and removed after few months. Patency of the bile duct was assessed by cholangiography, the liver function test and magnetic resonance imaging (MRI). Two patients aged 33 and 59 years old underwent lateral reconstruction of the bile duct for defects secondary to choledocotomy for stone extraction or during dissection for Mirizzi syndrome. The defects measured 2 and 3 cm and occupied half of the bile duct circumference. The postoperative course was marked by low output biliary fistula resolved spontaneously. In one patient, the T tube was removed at 3 months after surgery and MRI at 9 months showed strictly normal aspect of the bile duct with normal liver function test. The second patient is going very well 2 months after surgery and the T tube is closed. Lateral reconstruction of the bile duct can be safely achieved with the vascularized round ligament. We will extend our indications to tubular reconstruction.

  10. Anatomic variations in intrahepatic bile ducts in a north Indian population.

    Science.gov (United States)

    Sharma, Vijay; Saraswat, Vivek Anand; Baijal, Sanjay Saran; Choudhuri, Gourdas

    2008-07-01

    In the present study, we described the anatomical variations in the branching patterns of intrahepatic bile ducts (IHD) and determined the frequency of each variation in north Indian patients. There are no data from India. The study group consisted of 253 consecutive patients (131 women) undergoing endoscopic retrograde cholangiograms for different indications. Anatomical variations in IHD were classified according to the branching pattern of the right anterior segmental duct (RASD) and the right posterior segmental duct (RPSD), presence or absence of first-order branch of left hepatic duct (LHD) and of an accessory hepatic duct. Anatomy of the IHD was typical in 52.9% of cases (n = 134), showing triple confluence in 11.46% (n = 29), anomalous drainage of the RPSD into the LHD in 18.2% (n = 46), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 7.1% (n = 18), drainage of the right hepatic duct (RHD) into the cystic duct 0.4% (n = 1), presence of an accessory duct leading to the CHD or RHD in 4.7% (n = 12), individual drainage of the LHD into the RHD or CHD in 2.4% (n = 6), and unclassified or complex variations in 2.7% (n = 7). None had anomalous drainage of RPSD into the cystic duct. The branching pattern of IHD was atypical in 47% patients. The two most common variations were drainage of the RPSD into the LHD (18.2%) and triple confluence of the RASD, RPSD, and LHD (11.5%).

  11. Research on Duct Flow Field Optimisation of a Robot Vacuum Cleaner

    Directory of Open Access Journals (Sweden)

    Xiao-bo Lai

    2011-11-01

    Full Text Available The duct of a robot vacuum cleaner is the length of the flow channel between the inlet of the rolling brush blower and the outlet of the vacuum blower. To cope with the pressure drop problem of the duct flow field in a robot vacuum cleaner, a method based on Pressure Implicit with Splitting of Operators (PRISO algorithm is introduced and the optimisation design of the duct flow field is implemented. Firstly, the duct structure in a robot vacuum cleaner is taken as a research object, with the computational fluid dynamics (CFD theories adopted; a three-dimensional fluid model of the duct is established by means of the FLUENT solver of the CFD software. Secondly, with the k-∊ turbulence model of three-dimensional incompressible fluid considered and the PRISO pressure modification algorithm employed, the flow field numerical simulations inside the duct of the robot vacuum cleaner are carried out. Then, the velocity vector plots on the arbitrary plane of the duct flow field are obtained. Finally, an investigation of the dynamic characteristics of the duct flow field is done and defects of the original duct flow field are analysed, the optimisation of the original flow field has then been conducted. Experimental results show that the duct flow field after optimisation can effectively reduce pressure drop, the feasibility as well as the correctness of the theoretical modelling and optimisation approaches are validated.

  12. Research on Duct Flow Field Optimisation of a Robot Vacuum Cleaner

    Directory of Open Access Journals (Sweden)

    Xiao-bo Lai

    2011-11-01

    Full Text Available The duct of a robot vacuum cleaner is the length of the flow channel between the inlet of the rolling brush blower and the outlet of the vacuum blower. To cope with the pressure drop problem of the duct flow field in a robot vacuum cleaner, a method based on Pressure Implicit with Splitting of Operators (PRISO algorithm is introduced and the optimisation design of the duct flow field is implemented. Firstly, the duct structure in a robot vacuum cleaner is taken as a research object, with the computational fluid dynamics (CFD theories adopted; a three‐dimensional fluid model of the duct is established by means of the FLUENT solver of the CFD software. Secondly, with the k‐ε turbulence model of three‐ dimensional incompressible fluid considered and the PRISO pressure modification algorithm employed, the flow field numerical simulations inside the duct of the robot vacuum cleaner are carried out. Then, the velocity vector plots on the arbitrary plane of the duct flow field are obtained. Finally, an investigation of the dynamic characteristics of the duct flow field is done and defects of the original duct flow field are analysed, the optimisation of the original flow field has then been conducted. Experimental results show that the duct flow field after optimisation can effectively reduce pressure drop, the feasibility as well as the correctness of the theoretical modelling and optimisation approaches are validated.

  13. Congenital double bile duct presenting as recurrent cholangitis in a child

    Directory of Open Access Journals (Sweden)

    K.D. Chakravarty

    2015-12-01

    Full Text Available Double common bile duct (DCBD is a rare congenital anomaly. Most of these bile duct anomalies are associated with bile duct stones, anomalous pancreaticobiliary junction (APBJ, pancreatitis and bile duct or gastric cancers. Early detection and treatment is important to avoid long term complications. Surgical resection of the anomalous bile duct and reconstruction of the biliary enteric anastomosis is the treatment of choice. We report a rare case of DCBD anomaly in a girl, who presented with recurrent cholangitis. She had type Va DCBD anomaly. She underwent successful resection of the bile duct and reconstruction of the biliary enteric anastomosis. Preoperative imaging and diagnosis of the congenital biliary anomaly is very important to avoid intraoperative bile duct injury. Review of the literature shows very few cases of type Va DCBD, presenting with either bile duct stones or APBJ.

  14. Anatomic relationship of intrahepatic bile ducts to portal veins revisited

    International Nuclear Information System (INIS)

    Bret, P.M.; Stempel, J.; Atri, M.; Lough, J.O.; Illescas, F.F.

    1987-01-01

    It is well accepted that intrahepatic bile ducts lie in front of corresponding portal vein branches. Since the authors' clinical experience with US was different, they studied 18 normal necropsy cadaver livers. The common bile duct, main portal vein, and hepatic artery were cannulated and injected respectively with air, dilute contrast medium, and mineral oil. The livers were then examined in anatomic position with CT. In the left lobe of the liver, the bile ducts were anterior to the portal vein in seven cases, posterior in seven cases, and were tortuous both anterior and posterior in three cases. In the right lobe, the bile ducts were anterior in nine cases, posterior in five cases, tortuous in one case, and not seen in two cases. In the porta hepatis, the bile ducts were anterior in eight cases, posterior in one case, tortuous in five cases, and not seen in three cases. Histologic specimens confirmed the anterior and posterior location of the bile ducts relative to the portal veins. In conclusion, intrahepatic bile ducts can be either anterior or posterior to the corresponding portal vein branches

  15. Gas turbine engine turbine blade damaging estimate in maintenance

    Directory of Open Access Journals (Sweden)

    Ель-Хожайрі Хусейн

    2004-01-01

    Full Text Available  The factors determining character and intensity of corrosive damages of gas turbine blades are analyzed in the article. The classification of detrimental impurities polluting gas turbine airflow duct and injuring blade erosion damages are given. Common features of the method of turbine blade corrosive damage estimation are shown in the article.

  16. Are Ducted Mini-Splits Worth It?

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, Jonathan M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Maguire, Jeffrey B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Metzger, Cheryn E. [Pacific Northwest National Laboratory; Zhang, Jason [Pacific Northwest National Laboratory

    2018-02-01

    Ducted mini-split heat pumps are gaining popularity in some regions of the country due to their energy-efficient specifications and their ability to be hidden from sight. Although product and install costs are typically higher than the ductless mini-split heat pumps, this technology is well worth the premium for some homeowners who do not like to see an indoor unit in their living area. Due to the interest in this technology by local utilities and homeowners, the Bonneville Power Administration (BPA) has funded the Pacific Northwest National Laboratory (PNNL) and the National Renewable Energy Laboratory (NREL) to develop capabilities within the Building Energy Optimization (BEopt) tool to model ducted mini-split heat pumps. After the fundamental capabilities were added, energy-use results could be compared to other technologies that were already in BEopt, such as zonal electric resistance heat, central air source heat pumps, and ductless mini-split heat pumps. Each of these technologies was then compared using five prototype configurations in three different BPA heating zones to determine how the ducted mini-split technology would perform under different scenarios. The result of this project was a set of EnergyPlus models representing the various prototype configurations in each climate zone. Overall, the ducted mini-split heat pumps saved about 33-60% compared to zonal electric resistance heat (with window AC systems modeled in the summer). The results also showed that the ducted mini-split systems used about 4% more energy than the ductless mini-split systems, which saved about 37-64% compared to electric zonal heat (depending on the prototype and climate).

  17. CT findings of thyroglossal duct cyst

    International Nuclear Information System (INIS)

    Kim, Dong Oh; Kim, Hong Soo; So, Hyun Soon; Nam, Mee Young; Choi, Jae Ho; Rhee, Hak Song

    1995-01-01

    The purpose of this study was to evaluate the CT findings of thyroglossal duct cysts. Sixteen patients with pathologically proved thyroglossal duct cysts were included in the study. CT scans were assessed retrospectively for shape, size, location, density of the central portions, septations, rim enhancement, changes in the adjacent fascial planes and investment within the strap muscles in the infrahyoid cysts. Thirteen cases of thyroglossal duct cysts were seen as round or oval cystic masses, two cases of them were seen as irregular-shaped lobulated cystic masses, and one case was seen as ovoid soft tissue mass. The cysts were from 1.4 to 5.7 cm in diameter (mean, 2.6 cm). The cyst was infrahyoid in 15 cases and suprahyoid in one case. The cyst was located in midline in eight cases, off midline in four cases, and both midline and off midline in four cases. The density of the central portions ranged from 15 to 82HU (mean, 32HU). Septations were noted in four cases. Rim enhancement was seen in 14 cases (93%), and heterogeneously enhancing soft tissue mass was seen in one case. In four cases, abnormal fascial planes were observed. All but one of the infrahyoid cysts (14/15) were embedded within the strap muscles, and one case of them was located anteriorly to strap muscles. CT permits one to make the diagnosis a thyroglossal duct cyst with a high degree of accuracy, as it can differentiate thyroglossal duct cysts from the other anterior neck masses by their typical location, characteristic morphology, and investment within the strap muscles

  18. Liver and Bile Duct Cancer—Health Professional Version

    Science.gov (United States)

    Liver cancer includes two major types: hepatocellular carcinoma (HCC) and intrahepatic bile duct cancer, also known as cholangiocarcinoma. Find evidence-based information on liver and bile duct cancer treatment, causes and prevention, screening, research, genomics and statistics.

  19. Catalytic hot gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P [VTT Energy, Espoo (Finland)

    1997-12-31

    Gasification gas that contains particulates can be purified from tars and ammonia by using nickel monolith catalysts. Temperatures over 900 deg C are required at 20 bar pressure to avoid deactivation by H{sub 2}S and carbon. Dolomites and limestones are effective tar decomposing catalysts only when calcined. Tar decomposition in gasification conditions can take place by steam or dry (CO{sub 2}) reforming reactions. These reactions follow apparent first order kinetics with respect to hydrocarbons in gasification conditions. (author) (16 refs.)

  20. Catalytic hot gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P. [VTT Energy, Espoo (Finland)

    1996-12-31

    Gasification gas that contains particulates can be purified from tars and ammonia by using nickel monolith catalysts. Temperatures over 900 deg C are required at 20 bar pressure to avoid deactivation by H{sub 2}S and carbon. Dolomites and limestones are effective tar decomposing catalysts only when calcined. Tar decomposition in gasification conditions can take place by steam or dry (CO{sub 2}) reforming reactions. These reactions follow apparent first order kinetics with respect to hydrocarbons in gasification conditions. (author) (16 refs.)

  1. Heating, Ventilation, and Air Conditioning Design Strategy for a Hot-Humid Production Builder

    Energy Technology Data Exchange (ETDEWEB)

    Kerrigan, P. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-03-01

    BSC worked directly with the David Weekley Homes - Houston division to redesign three floor plans in order to locate the HVAC system in conditioned space. The purpose of this project is to develop a cost effective design for moving the HVAC system into conditioned space. In addition, BSC conducted energy analysis to calculate the most economical strategy for increasing the energy performance of future production houses. This is in preparation for the upcoming code changes in 2015. The builder wishes to develop an upgrade package that will allow for a seamless transition to the new code mandate. The following research questions were addressed by this research project: 1. What is the most cost effective, best performing and most easily replicable method of locating ducts inside conditioned space for a hot-humid production home builder that constructs one and two story single family detached residences? 2. What is a cost effective and practical method of achieving 50% source energy savings vs. the 2006 International Energy Conservation Code for a hot-humid production builder? 3. How accurate are the pre-construction whole house cost estimates compared to confirmed post construction actual cost? BSC and the builder developed a duct design strategy that employs a system of dropped ceilings and attic coffers for moving the ductwork from the vented attic to conditioned space. The furnace has been moved to either a mechanical closet in the conditioned living space or a coffered space in the attic.

  2. Modeling of effusion in the presence of a turbulent parietal flow. Application to the thermal protection of walls; Modelisation de l`effusion en presence d`un ecoulement parietal turbulent. Application a la protection thermique des parois

    Energy Technology Data Exchange (ETDEWEB)

    Belletre, J.; Bataille, F.; Lallemaned, A. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France)

    1997-12-31

    The effusion of a cold gas through a porous wall submitted to a hot turbulent parietal flow is studied in order to reduce the convective heat fluxes between the wall and the hot fluid. A modeling of the turbulent dynamical and thermal boundary layer is obtained using a RNG k-{epsilon} model. The cold gas injection through the porous plate and the fluid-wall friction are taken into account using a discrete succession of pores and solid elements. For a 1% injection rate, the modeling results agree with experiments performed in a test-duct. On the other hand, convective heat fluxes on the porous plate are calculated using semi-empirical correlations and different injection rates and temperatures of the hot flow. (J.S.) 23 refs.

  3. Argon/UF6 plasma exhaust gas reconstitution experiments using preheated fluorine and on-line diagnostics. [fissioning uranium plasma core reactor design

    Science.gov (United States)

    Roman, W. C.

    1979-01-01

    The feasibility of employing a flowing, high-temperature, pure fluorine/UF6 regeneration system to efficiently convert a large fraction of the effluent plasma exhaust back to pure UF6 was demonstrated. The custom built T.O.F. mass spectrometer sampling system permitted on-line measurements of the UF6 concentration at different locations in the exhaust system. Negligible amounts ( 100 ppm) of UF6 were detected in the axial bypass exhaust duct and the exhaust ducts downstream of the cryogenic trap system used to collect the UF6, thus verifying the overall system efficiency over a range of operating conditions. Use of a porous Monel duct as part of the exhaust duct system, including provision for injection of pure fluorine, provided a viable technique to eliminate uranium compound residue on the inside surface of the exhaust ducts. Typical uranium compound mass deposition per unit area of duct was 2 micron g/sq cm. This porous duct technique is directly applicable to future uranium compound transfer exhaust systems. Throughout these experiments, additional basic data on the corrosion aspects of hot, pressurized UF6/fluorine were also accumulated.

  4. Time course of collagen peak in bile duct-ligated rats

    OpenAIRE

    Tarcin, Orhan; Basaranoglu, Metin; Tahan, Veysel; Tahan, Gülgün; Sücüllü, Ilker; Yilmaz, Nevin; Sood, Gagan; Snyder, Ned; Hilman, Gilbert; Celikel, Cigdem; Tözün, Nurdan

    2011-01-01

    Abstract Background One of the most useful experimental fibrogenesis models is the "bile duct-ligated rats". Our aim was to investigate the quantitative hepatic collagen content by two different methods during the different stages of hepatic fibrosis in bile duct-ligated rats on a weekly basis. We questioned whether the 1-wk or 4-wk bile duct-ligated model is suitable in animal fibrogenesis trials. Methods Of the 53 male Wistar rats, 8 (Group 0) were used as a healthy control group. Bile duct...

  5. Internal radiotherapy for hilar bile duct cancer

    International Nuclear Information System (INIS)

    Ryu, Munemasa; Ogino, Takashi; Konishi, Hiroshi

    1999-01-01

    By December 1998, 24 patients with non-resected hilar bile duct cancer (mean age of 74) had received bile duct intracavitary irradiation and 13 patients with residual cancer after resection of hilar bile duct cancer had received postoperative intracavitary irradiation. After they were externally irradiated 30 Gy in total by 15 fractions (2 Gy/time, 5 times in a week), intracavitary irradiation using 192-Ir was given 5 times in total (2 times in a week) from 3 weeks after external irradiation under the condition which dose became 8 Gy in depth of 10 mm from radiation source. The cases of postoperative irradiation had 3 times in total. As for 20 patients of non-resected hilar bile duct cancer without metastasis, 50% survival time was 265 days and there was no 5 year survivor. Fifty percents survival time of 4 patients with metastasis was 113 days. The effect of local control was recognized in 20 patients (83.3%). In 13 patients of postoperative irradiation, 50% survival time was 554 days, and survival rate of 3 years was 28%. (K.H.)

  6. Flow characteristics of developing laminar steady flows in a straight duct connected to a square curved duct

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Hyun Chull [Chosun Univ., Gwangju (Korea, Republic of)

    2005-05-01

    In the present study, the characteristics of developing steady laminar flows of a straight duct connected to a 180 .deg. curved duct were examined in the entrance region through experimental measurement. Flow characteristics such as shear stress distributions, pressure distributions and friction coefficient experimentally in a square cross-sectional straight duct by using the PIV system. For the PIV measurement by particles produced from mosquito coils particles. The experimental data were obtained at 9 points dividing the test sections by 400 mm. Experimental results can be summarized as follows. Critical Reynolds number, Re{sub cr} which indicates transition from laminar steady flow to transition steady flow was 2,150. Shear stress per unit length on the wall was stronger than that in the fully developed flow region. This was attributed to the fact that shear stress and pressure loss in the curvature of a duct were increased. Pressure distributions were gradually decreased irrespective of Reynolds number in the whole test section. This trends were in a good agreement with the reference results. Pipe friction coefficient in the steady state flow region was calculate from method of least squares. The co-relationship between fiction coefficient and Reynolds number was established as follow; {lambda}=56/Re.

  7. A remote joint system for large vacuum ducts

    International Nuclear Information System (INIS)

    Hagmann, D.B.; Coughlan, J.B.

    1983-01-01

    A large remote vacuum duct joining system has been developed for fusion machines that uses several two-jaw screwdriven clamps. The preferred location for clamp installation is inside the vacuum duct where access space is available for the actuating device. It also decreases space needed for handling operations exterior to the duct. The clamp system is unique in that it is low cost, applies force directly over the seal, permits leak testing to the seal annulus, is highly reliable, can be remotely replaced, and is usable on a variety of other applications

  8. [Salivary gland drainage into the thyroglossal duct].

    Science.gov (United States)

    Siem, G; Natvig, K; Kolbenstvedt, A; Lømo, J

    2001-01-20

    Failure in regression of the thyroglossal duct is one of the most common reasons for midline swellings in the neck. Several authors have described recurrent thyroglossal duct remnants with persisting draining sinuses. However, few have described accessory salivary glands that drain into the thyroglossal duct. In this article we report two such cases with midline salivary glands in the floor of the mouth. These two patients were subsequently successfully treated with radical tissue resection in the area between the hyoid bone and foramen cecum. Preoperative fistulography or sinography was useful to demonstrate the ductal ramification of the salivary glands, and use of methylene blue during surgery proved of significant value for the result.

  9. Energy efficiency and emissions of arc furnaces in the steel industry; Energieeffizienz und Emissionen der Lichtbogenoefen in der Stahlindustrie

    Energy Technology Data Exchange (ETDEWEB)

    Kirschen, M.

    2007-07-01

    The operation of the electric arc furnace obeys economic constraints that require cost optimal use of the resources scrap, scrap substitutes, alloys, direct reduced iron, pig iron, oxygen, fuel gas, and energy. On the other hand, legal restrictions for minimum emissions must be observed. Comprehensive process models and strategies to optimize the EAF steel production require detailed knowledge about both energy flow rates and emissions. However, this data is often not available in the meltshop due to technical problems or high effort for maintenance of on-line off-gas analysis systems at the EAF. The Institute for Industrial Furnaces and Heat Engineering of RWTH Aachen University performed off-gas measurements at various EAFs during steel production. In some plant trials off-gas measurements were conducted simultaneously at two points in the dedusting system in order to determine the otherwise unknown volume flow rate of air at the gap between the EAF elbow and the hot gas duct. In this work, state-of-the-art off-gas analysis systems are presented. First hints for process development of particular EAFs are derived from off-gas data. Off-gas data complement the meltshop data, that are required for complete mass and energy balances. From recent energy balances, the EAF process is evaluated with respect to off-gas energy and energy efficiency. Recent energy balances from our measurements and from the literature of the last decade show total energy demand between 600 kWh/t and 850 kWh/t and energy efficiency values up to 70%. EAFs with scrap pre-heating technologies achieve highest energy efficiency values up to 70%. Measurements of off-gas and air volume flow rates monitor the efficiency of the EAF dedusting plant in combination with the EAF. With direct exhaust control based on furnace pressure measurement, the specific off-gas mass and energy is decreased significantly. Improvement of the analysis equipment for off-gas measurements at the EAF with focus on very

  10. Preliminary design for hot dirty-gas control-valve test facility. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    This report presents the results of a preliminary design and cost estimating effort for a facility for the testing of control valves in Hot Dirty Gas (HDGCV) service. This design was performed by Mittelhauser Corporation for the United States Department of Energy's Morgantown Energy Technology Center (METC). The objective of this effort was to provide METC with a feasible preliminary design for a test facility which could be used to evaluate valve designs under simulated service conditions and provide a technology data base for DOE and industry. In addition to the actual preliminary design of the test facility, final design/construction/operating schedules and a facility cost estimate were prepared to provide METC sufficient information with which to evaluate this design. The bases, assumptions, and limitations of this study effort are given. The tasks carried out were as follows: METC Facility Review, Environmental Control Study, Gas Generation Study, Metallurgy Review, Safety Review, Facility Process Design, Facility Conceptual Layout, Instrumentation Design, Cost Estimates, and Schedules. The report provides information regarding the methods of approach used in the various tasks involved in the completion of this study. Section 5.0 of this report presents the results of the study effort. The results obtained from the above-defined tasks are described briefly. The turnkey cost of the test facility is estimated to be $9,774,700 in fourth quarter 1979 dollars, and the annual operating cost is estimated to be $960,000 plus utilities costs which are not included because unit costs per utility were not available from METC.

  11. Visualization of the thoracic duct by lymphoscintigraphy

    International Nuclear Information System (INIS)

    Baulieu, F.; Baulieu, J.L.; Itti, R.; Tours Univ., 37

    1987-01-01

    Imaging of the thoracic duct is usually performed by radiological lymphography. However, this procedure, which uses an oil based dye injected directly into the lymph channels, has some adverse effects. In this paper we note that lymphoscintigraphy, a physiological and non invasive method, may visualize thoracic duct abnormalities, and might be particularly usefull when radiological lymphography is contraindicated. (orig.)

  12. The experimental study of radiation injury on bile duct and liver tissue

    International Nuclear Information System (INIS)

    Cao Guiwen; Wang Bin; Sun Yequan; Shao Xueye; Ning Houfa; Sui Shouguang; Wang Xiuchun; Bai Xuming

    2007-01-01

    Objective: To investigate the safety, acceptance and the effective extent of 192 Ir-internal irradiation, providing theoretical guidelines for HC. Methods: Sixteen male healthy hybrid dogs enrolled in the experiment were divided into 4 groups of 4 each. The brachytherapy applicator was introduced from gall bladder into the convergence of cystic duct with common hepatic duct during the operation and a small chip of 1 cm 3 liver tissue was cut off and taken for control later on. The animals in group A-D were irradiated by 192 Ir-internal irradiation with 30 Gy, 40 Gy, 50 Gy arid 60 Gy at the correlative dose points respectively. Animals were put to death after 10 days subsequently, with sampling specimens obtained from radiation cystic duct and the in between liver tissue with the distant cystic duct. The radiation injury of the cystic duct and liver tissue near bile ducts were observed and studied by light microscope and transmission election microscope. Results: By the limit of the safest endurance dose(50 Gy) of Bile duct, unreversed injury of the nuclei of liver cells occurred at 0 to 15 mm from bile duct revealed by transmission electron microscope and light microscope. The whole biliary duct wall would be undergone necrosis with irradiation dose over 60 Gy. Conclusions: Normal bile duct possesses good endurance to 192 Ir-internal irradiation. Within the safest endurance limit of 50 Gy the effective irradiation field could reach 15 mm from the involved bile duct. (authors)

  13. Evaporation heat transfer of hot water from horizontal free service

    International Nuclear Information System (INIS)

    Koizumi, Y.; Ebihara, Y.; Hirota, T.; Murase, M.

    2011-01-01

    Evaporation heat transfer from the hot water flow to the cold air flow in a horizontal duct was examined. Hot water was in the range of 35 o C ~ 65 o C. Cold air was approximately 25 o C. The air velocity was varied from 0.0656 m/s ~ 1.41 m/s. The heat transfer rate from the water flow to the air flow became large with an increase in the air velocity. The higher the water temperature was, the larger the heat transfer rate was. When the total heat flux from water to the air flow is divided into two terms; the evaporation term and the forced flow convection term, the evaporation term dominate main part and that is about 90 ~ 80 % of the total heat flux. The measured values of the evaporation term and the forced flow convection term were larger than the predicted because of the effect of the diffusion of evaporated vapor. The correlation to predict the heat transfer from the hot water flow to the cold air flow with the evaporation was developed by modifying the laminar flow mass transfer correlation and the laminar forced convection heat transfer correlation. Good results were obtained. (author)

  14. Evaporation heat transfer of hot water from horizontal free service

    Energy Technology Data Exchange (ETDEWEB)

    Koizumi, Y.; Ebihara, Y.; Hirota, T. [Shinshu Univ., Ueda, Nagano (Japan); Murase, M. [INSS, Mihama-cho, Fukui (Japan)

    2011-07-01

    Evaporation heat transfer from the hot water flow to the cold air flow in a horizontal duct was examined. Hot water was in the range of 35{sup o}C ~ 65{sup o}C. Cold air was approximately 25{sup o}C. The air velocity was varied from 0.0656 m/s ~ 1.41 m/s. The heat transfer rate from the water flow to the air flow became large with an increase in the air velocity. The higher the water temperature was, the larger the heat transfer rate was. When the total heat flux from water to the air flow is divided into two terms; the evaporation term and the forced flow convection term, the evaporation term dominate main part and that is about 90 ~ 80 % of the total heat flux. The measured values of the evaporation term and the forced flow convection term were larger than the predicted because of the effect of the diffusion of evaporated vapor. The correlation to predict the heat transfer from the hot water flow to the cold air flow with the evaporation was developed by modifying the laminar flow mass transfer correlation and the laminar forced convection heat transfer correlation. Good results were obtained. (author)

  15. Iatrogenic injury of an aberrant right posterior sectoral bile duct

    African Journals Online (AJOL)

    (Figs 1 and 2). A week later, an endoscopic retrograde cholangiopancreatography. (ERCP) examination was performed. This showed no filling of the right posterior sectoral ducts but normal opacification of the other ducts. (Figs 3a and b). These findings led to the diagnosis of an aberrant right posterior sectoral bile duct that ...

  16. Imaging features of intraductal papillary neoplasm of the bile duct

    International Nuclear Information System (INIS)

    Liu Yubao; Li Meng; Zhong Xiaomei; Liu Zaiyi; Liang Changhong

    2014-01-01

    Objective: To investigate the CT and MRI features of intraductal papillary neoplasm of the bile duct (IPNB). Methods: Thirty eight patients with IPNB finally diagnosed by puncture biopsy or surgery were enrolled in this study. All the CT or MRI data were investigated retrospectively. Twenty one patients underwent CT examinations, 17 patients underwent MRI examinations. The features of IPNB including the distribution features of the nodules or masses, CT and MRI features of cholangiectasis, mucus were analyzed. The accuracy differences of CT and MRI for the preoperatively diagnosing mucus and tumor growing along mucous were compared by nonparametric test. Results: The lesions (including 5 patients with solitary lesions and 19 patients with multiple lesions) were located in intrahepatic bile duct in 24 patients, 3 patients occurred simultaneously in intrahepatic and portal bile duct, 2 lesions occurred in portal bile duct, 8 lesions occurred in common bile duct, the lesions of 1 patient occurred simultaneously in common bile duct, cystic duct and gallbladder. Seventeen and 11 patients appeared nodules locating in dilated bile duct on CT and MRI, respectively. Four and 5 patients appeared cystic lesions with multiple nodules of the liver on CT and MRI, respectively. Higher contrast enhancement on CT and MRI in arterial phase than that in portal vein and equilibrium phase were observed in 18 and 12 patients, respectively. Excluding the patients undergoing puncture, CT was better than MRI in evaluating whether the mucus was present, with the accuracies of 30.0% (6/20) and 6.3% (1/16) for CT and MRI, respectively (Z=2.58, P<0.05). CT was worse than MRI in preoperatively evaluating the features of tumor growing along mucous, with the accuracies of 77.8% (14/18) and 92.6% (13/14) for CT and MRI, respectively (Z=4.23, P<0.01). Conclusion: IPNB had the features of growing along mucous of the bile duct, nodule or mass in dilated bile duct and other features, CT and MRI are

  17. Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

    Science.gov (United States)

    1980-01-01

    The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

  18. Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

    Science.gov (United States)

    1980-07-01

    The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

  19. Liquid-fog and liquid-gas phase transitions in hot nuclei

    International Nuclear Information System (INIS)

    Karnaukhov, V.A.; ); Oeschier, H.; Budzanowski, A.

    2006-01-01

    Thermal multifragmentation of hot nuclei is interpreted as the nuclear liquid-fog phase transition inside the spinodal region. The exclusive data for p(8.1 GeV) + Au collisions are analyzed within the framework of statistical model (SSM). It is found that the partition hot nuclei is specified after expansion to a volume equal to V t = (2.6 ± 0.3)V 0 . The freeze-out volume is found to be twice as large V f = (5 ± 1)V 0 . The similarity between multifragmentation and ordinary fission is discussed [ru

  20. High Accuracy Acoustic Relative Humidity Measurement inDuct Flow with Air

    Directory of Open Access Journals (Sweden)

    Cees van der Geld

    2010-08-01

    Full Text Available An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0–12 m/s with an error of ±0.13 m/s, temperature 0–100 °C with an error of ±0.07 °C and relative humidity 0–100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

  1. Preliminary Design Analysis of a HGD for the NHDD Program at Korea

    International Nuclear Information System (INIS)

    Song, Kee Nam; Lee, H. Y.; Lee, S. B.; Kim, Y. W.

    2007-01-01

    Korea Atomic Energy Research Institute is in the process of carrying out a Nuclear Hydrogen Development and Demonstration (NHDD) Program by considering the indirect cycle gas cooled reactors that produce heat at temperatures in the order of 950 .deg. C. A coaxial double-tube Hot Gas Duct (HGD) is a key component connecting the reactor pressure vessel and the intermediate heat exchanger for the NHDD program. Recently, a preliminary design evaluation for the hot gas duct of the NHDD program was carried out. These preliminary design activities include a decision on the geometric dimensions, a strength evaluation, an appropriate material selection, and identifying the design code for the HGD. In this study, a preliminary strength evaluation for the HGD of the NHDD program has been undertaken based on the HTR-10 design concepts. Also, a preliminary evaluation of the creep-fatigue damage for a high temperature HGD structure has been carried out according to the draft code case for Alloy 617. Preliminary strength evaluation results for the HGD showed that the geometric dimensions of the proposed HGD would be acceptable for the design requirements

  2. Material development for gas-cooled high temperature reactors for the production of nuclear process heat

    International Nuclear Information System (INIS)

    Nickel, H.

    1977-04-01

    In the framework of the material development for gas-cooled high temperature reactors, considerable investigations of the materials for the reactor core and the primary cicuit are being conducted. Concerning the core components, the current state-of-the-art and the objectives of the development work on the spherical fuel elements, coated particles and structural graphite are discussed. As an example of the structural graphite, the non-replaceable reflector of the process heat reactor is discussed. The primary circuit will be constructed mainly from metallic materials, although some ceramics are also being considered. Components of interest are hot gas ducts, liners, methane reformer tubes and helium-helium intermediate heat exchangers. The gaseous impurities present in the helium coolant may cause oxidation and carburization of the nickel-base and iron-base alloys envisaged for use in these components, with a possible associated adverse effect on the mechanical properties such as creep and fatigue. Test capacity has therefore been installed to investigate materials behaviour in simulated reactor helium under both constant and alternating stress conditions. The first results on the creep behaviour of several alloys in impure helium are presented and discussed. (orig./GSC) [de

  3. Ursodeoxycholic acid treatment of vanishing bile duct syndromes

    NARCIS (Netherlands)

    Pusl, Thomas; Beuers, Ulrich

    2006-01-01

    Vanishing bile duct syndromes (VBDS) are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from liver failure. The majority of adult patients with VBDS suffer from primary biliary

  4. Positive predictive value of cholescintigraphy in common bile duct obstruction

    International Nuclear Information System (INIS)

    Lecklitner, M.L.; Austin, A.R.; Benedetto, A.R.; Growcock, G.W.

    1986-01-01

    Technetium-99m DISIDA imaging was employed in 400 patients to differentiate obstruction of the common bile duct from medical and other surgical causes of hyperbilirubinemia. Sequential anterior images demonstrated variable degrees of liver uptake, yet there was no evidence of intrabiliary or extrabiliary radioactivity for at least 4 hr after injection in 25 patients. Twenty-three patients were surgically documented to have complete obstruction of the common bile duct. One patient had hepatitis, and another had sickle cell crisis without bile duct obstruction. The remaining patients had either partial or no obstruction of the common bile duct. We conclude that the presence of liver uptake without evident biliary excretion by 4 hr on cholescintigraphy is highly sensitive and predictive of total obstruction of the common bile duct

  5. Common Bile Duct Perforation Due to Tuberculosis: A Case Report

    OpenAIRE

    Razman Jarmin; Shaharin Shaharuddin

    2004-01-01

    A young man with HIV presented with biliary peritonitis secondary to spontaneous common bile duct perforation. Investigation revealed that the perforation was due to Mycobacterium tuberculosis. Tuberculosis of the bile duct is uncommon and usually presents with obstructive jaundice due to stricture. Bile duct perforation due to tuberculosis is extremely rare. Its management is discussed.

  6. Trypsin level in gallbladder bile and ductitis and width of the cystic duct.

    Science.gov (United States)

    Vracko, J; Wiechel, K L

    2000-01-01

    The change from laparotomy to laparoscopy for cholecystectomy has raised the question of how to manage concomitant bile duct stones. The present-day interest--and controversy--has focused on a transcystic approach reported to be feasible in 66-96% of cases, but without explaining the necessary prerequisite: the widening of the cystic duct. The cystic duct, wide mainly in patients with bile duct stones, has been reported to be highly variable: from strictured to very wide. The present study aims at comparing the trypsin level in the gallbladder bile and the cystic duct morphology and width in patients with and without bile duct stones. A prospective series of 63 gallstone patients, 30 with and 33 without bile duct stones (controls), underwent cholecystectomy and bile duct clearance. The study includes the trypsin level in the gallbladder bile, the width and morphology of the cystic duct, and the size of the gallstones. The patients with bile duct stones had, in contrast to the controls, higher trypsin levels in the gallbladder bile (P extraction feasible.

  7. Performance of nickel base superalloy components in gas turbines

    DEFF Research Database (Denmark)

    Dahl, Kristian Vinter

    2006-01-01

    The topic of this thesis is the microstructural behaviour of hot section components in the industrial gas turbine......The topic of this thesis is the microstructural behaviour of hot section components in the industrial gas turbine...

  8. Agenesis of the gallbladder with hypoplastic cystic duct diagnosed at laparoscopy.

    Science.gov (United States)

    Kwon, A-Hon; Yanagimoto, Hiroaki; Matsui, Yoichi; Imamura, Atsushi

    2006-08-01

    An 86-year-old man was admitted to our department with complaints of intermittent upper abdominal pain. Ultrasonography of the abdomen showed dilated extrahepatic bile ducts containing stones; however, the gallbladder was not clearly identified. Magnetic resonance cholangiopancreatography showed dilated extrahepatic ducts and choledocholithiasis without gallbladder visualization. The stone extraction was performed with endoscopic sphincterotomy. Three-dimensional images using spiral-computed tomography after intravenous-infusion cholangiography clearly demonstrated an obstruction of the cystic duct. The patient was scheduled for laparoscopic cholecystectomy. At laparoscopy, the gallbladder fossa was not identified on the undersurface of the liver. Despite a thorough examination of the intrahepatic (left-sided within the lesser omentum), retroperitoneal, retrohepatic (within the falciform ligament), retroduodenal, and retropancreatic areas using laparoscopic ultrasonography, the gallbladder was not found. After careful dissection of the hepatoduodenal ligament, the dilated extrahepatic bile duct and a 1-cm length of hypoplastic cystic duct were found. Gallbladder agenesis is usually accompanied by the lack of the cystic duct. The present case is the third report of gallbladder agenesis with a patent or hypoplastic cystic duct.

  9. 3D Numerical Study of Velocity Profiles and Thermal Mixing in Passive, Infrared Suppression Devices for Gas Turbine Engine Driven Generators

    National Research Council Canada - National Science Library

    Blackwell, Neal E

    2002-01-01

    ...) suppression device for exhaust ducting. The results, for a gas turbine driven generator, yield a novel design that is more compact and allows for shorter duct lengths, hence enabling associated camouflage netting to be lower in height...

  10. Design of Fire/Gas Penetration Seals and fire exposure tests for Tokamak Fusion Test Reactor experimental areas

    International Nuclear Information System (INIS)

    Cavalluzzo, S.

    1983-01-01

    A Fire/Gas Penetration Seal is required in every penetration through the walls and ceilings into the Test Cell housing the Tokamak Fusion Test Reactor (TFTR), as well as other adjacent areas to protect the TFTR from fire damage. The penetrations are used for field coil lead stems, diagnostics systems, utilities, cables, trays, mechanical devices, electrical conduits, vacuum liner, air conditioning ducts, water pipes, and gas pipes. The function of the Fire/Gas Penetration Seals is to prevent the passage of fire and products of combustion through penetrations for a period of time up to three hours and remain structurally intact during fire exposure. The Penetration Seal must withstand, without rupture, a fire hose water stream directed at the hot surface. There are over 3000 penetrations ranging in size from several square inches to 100 square feet, and classified into 90 different types. The material used to construct the Fire/Gas Penetration Seals consist of a single and a two-component room temperature vulcanizing (RTV) silicone rubber compound. Miscellaneous materials such as alumina silica refractory fibers in board, blanket and fiber forms are also used in the construction and assembly of the Seals. This paper describes some of the penetration seals and the test procedures used to perform the three-hour fire exposure tests to demonstrate the adequacy of the seals

  11. Cystic duct closure by sealing with bipolar electrocoagulation

    DEFF Research Database (Denmark)

    Schulze, S; Damgaard, B; Jørgensen, Lars Nannestad

    2010-01-01

    BACKGROUND: Cystic duct leakage after cholecystectomy is not uncommon and is a potentially serious complication. The aim of this study was to assess a bipolar sealing system (LigaSure) for closure of the cystic duct. METHODS: The records from consecutive laparoscopic cholecystectomies performed i...

  12. Common Bile Duct Perforation Due to Tuberculosis: A Case Report

    Directory of Open Access Journals (Sweden)

    Razman Jarmin

    2004-10-01

    Full Text Available A young man with HIV presented with biliary peritonitis secondary to spontaneous common bile duct perforation. Investigation revealed that the perforation was due to Mycobacterium tuberculosis. Tuberculosis of the bile duct is uncommon and usually presents with obstructive jaundice due to stricture. Bile duct perforation due to tuberculosis is extremely rare. Its management is discussed.

  13. Measured Performance of a Varied Airflow Small-Diameter Duct System

    Energy Technology Data Exchange (ETDEWEB)

    Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

    2017-03-01

    This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

  14. Measured Performance of a Varied Airflow Small-Diameter Duct System

    Energy Technology Data Exchange (ETDEWEB)

    Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

    2017-03-16

    This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

  15. Extracorporeal shock-wave lithotripsy of bile duct stones

    International Nuclear Information System (INIS)

    Lee, Jong Tae; Kim, Myung Joon; Yoo, Hyung Sik; Suh, Jung Ho; Lee, Moo Sang; Jo, Jang Hwan; Kim, Byung Ro

    1989-01-01

    During the past one and half year, we performed ESWL therapy in 13 patients with common bile duct and intrahepatic duct stones, applying Lithostar-R (Siemens co. West Germany) and analyzed their results. In 13 patients, 9 residual common bile duct stones and 7 intrahepatic duct stones were selected postoperatively. The size of stones were ranged from 0.7 cm to 3.5 cm in diameter. 2 stones were multiple and the remained 14 were single in number. The visualization of stones were done with fluoroscopy after the injection of contrast media via cholangiographic T-tube or ERCP. ESWL were applied continuously until stone disintegration was visible, or upto maximum number of 3500 discharge of shock wave. If not disintegrated upto 3500, patients were underwent second or third lithotripsy session with interval of one week. Our results showed that among 9 common bile duct stones, 4 were completely disintegrated and passed out spontaneously, but 3 partially fragmented and removed by the additional procedure. 2 were failed. Among 7 intrahepatic stones, 3 completely and 2 partially were succeeded. One stone partially fragmented were retained without removal and other one were failed. Skin petechia in all patients were revealed on the entry port of shock wave, but no serous complication was not occurred

  16. Extracorporeal shock-wave lithotripsy of bile duct stones

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Tae; Kim, Myung Joon; Yoo, Hyung Sik; Suh, Jung Ho; Lee, Moo Sang; Jo, Jang Hwan; Kim, Byung Ro [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1989-12-15

    During the past one and half year, we performed ESWL therapy in 13 patients with common bile duct and intrahepatic duct stones, applying Lithostar-R (Siemens co. West Germany) and analyzed their results. In 13 patients, 9 residual common bile duct stones and 7 intrahepatic duct stones were selected postoperatively. The size of stones were ranged from 0.7 cm to 3.5 cm in diameter. 2 stones were multiple and the remained 14 were single in number. The visualization of stones were done with fluoroscopy after the injection of contrast media via cholangiographic T-tube or ERCP. ESWL were applied continuously until stone disintegration was visible, or upto maximum number of 3500 discharge of shock wave. If not disintegrated upto 3500, patients were underwent second or third lithotripsy session with interval of one week. Our results showed that among 9 common bile duct stones, 4 were completely disintegrated and passed out spontaneously, but 3 partially fragmented and removed by the additional procedure. 2 were failed. Among 7 intrahepatic stones, 3 completely and 2 partially were succeeded. One stone partially fragmented were retained without removal and other one were failed. Skin petechia in all patients were revealed on the entry port of shock wave, but no serous complication was not occurred.

  17. Steady-state and transient simulations of gas cooled reactor with the computer code CATHARE

    International Nuclear Information System (INIS)

    Tauveron, N.; Saez, M.; Marchand, M.; Chataing, T.; Geffraye, G.; Cherel, J. M.

    2003-01-01

    This work concerns the design and safety analysis of Gas Cooled Reactors. The CATHARE code is used to test the design and safety of two different concepts, a High Temperature Gas Reactor concept (HTGR) and a Gas Fast Reactor concept (GFR). Relative to the HTGR concept, three transient simulations are performed and described in this paper: loss of electrical load without turbomachine trip, 10 inch cold duct break, 10 inch cold duct break combined with a tube rupture of a cooling exchanger. A second step consists in modelling a GFR concept. A nominal steady state situation at a power of 600 MW is obtained and first transient simulations are carried out to study decay heat removal situations after primary loop depressurisation

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

    DEFF Research Database (Denmark)

    Kowal, Justyna Magdalena; Yegutkin, G.G.; Novak, Ivana

    2015-01-01

    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, ou...... may be important in pancreas physiology and potentially in pancreas pathophysiology....... 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...

  19. Computed tomography of hepatocellular carcinoma. Dilatation of intrahepatic bile duct

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Soomi; Nakamura, Hitonobu; Tanaka, Ken; Hori, Shinichi; Tokunaga, Kou [Osaka Univ. (Japan). Faculty of Medicine

    1983-10-01

    Based on a series of CT of the liver in 125 patients with hepatoma and 45 patients with metastatic hepatic tumors, the mode of dilatation of the intrahepatic bile duct was examined. In patients with hepatoma, partia dilatations of intrahepatic bile duct were more commonly seen than general dilatations. On the other hand, there was no case of partial dilatation of the intrahepatic bile duct in patients with metastatic hepatic tumors. It could be concluded that partial dilatation of the intrahepatic bile duct is an useful CT finding to make a diagnosis of hepatoma, particularly to differentiate hepatoma from metastatic hepatic tumor.

  20. Hot corrosion behavior of Ni-Cr-W-C alloys in impure He gas

    International Nuclear Information System (INIS)

    Ohmura, Taizo; Sahira, Kensho; Sakonooka, Akihiko; Yonezawa, Noboru

    1977-01-01

    Influence of the minor alloy constituents such as Al, Mn and Si on the hot corrosion behavior of Ni-20Cr-20W-0.07C alloy was studied in 99.995%He gas at 1,000 0 C, in comparison with the behavior of commercial Ni-base superalloys (Hastelloy X and Inconel 617). The low oxidizing potential in the impure He gas usually causes selective oxidation of the elements described above and the growth of oxide whiskers on the surface of specimen at elevated temperatures. The intergranular attack was caused by selective oxidation of Al, Si and Mn. The spalling of oxide film was restrained by additions of Mn and Si, providing tough spinel type oxide film on the surface and 'keys' on the oxide-matrix interface respectively. The amount and morphology of the oxide whiskers depended on Si and Mn contents. Si of more than 0.29% without Mn always caused the growth of rather thinner whiskers with smooth surface, and the whiskers analyzed by electron diffraction patterns and EPMA to be Cr 2 O 3 containing Si. Mn addition changes the whiskers to thicker ones of spinel type oxide (MnCr 2 O 4 ) with rough surface. On the basis of these results, the optimum contents of Al, Mn and Si to minimize the growth of whiskers, the intergranular attack, and the spalling of oxide film were discussed. (auth.)

  1. A Review of Double Common Bile Duct and Its Sequelae.

    Science.gov (United States)

    Kolli, Sindhura; Etienne, Denzil; Reddy, Madhavi; Shahzad, Ghulamullah

    2018-02-01

    A double or accessory common bile duct (ACBD) is a rare congenital anomaly. We report the case of a 60-year-old American Asian male, who was found to have a double or duplicated common bile duct after being admitted for evaluation of a pancreatic mass. A duplicated bile duct has the same mucosa histologically as a single bile duct. However, the opening of a duplicated bile duct lacks a sphincter allowing retrograde flow of gut contents which results in a higher probability of intraductal calculus formation. On rare occasions, it can predispose to liver abscesses, pancreatitis, pancreatic cancer, gallbladder cancer, gastric cancer, and ampullary cancer depending on the location of the opening of the ACBD. We present an integrative review of the limited cases of ACBD with correlation to the current case and discussion regarding the aspects of diagnosis and management.

  2. Flow in curved ducts of varying cross-section

    Science.gov (United States)

    Sotiropoulos, F.; Patel, V. C.

    1992-07-01

    Two numerical methods for solving the incompressible Navier-Stokes equations are compared with each other by applying them to calculate laminar and turbulent flows through curved ducts of regular cross-section. Detailed comparisons, between the computed solutions and experimental data, are carried out in order to validate the two methods and to identify their relative merits and disadvantages. Based on the conclusions of this comparative study a numerical method is developed for simulating viscous flows through curved ducts of varying cross-sections. The proposed method is capable of simulating the near-wall turbulence using fine computational meshes across the sublayer in conjunction with a two-layer k-epsilon model. Numerical solutions are obtained for: (1) a straight transition duct geometry, and (2) a hydroturbine draft-tube configuration at model scale Reynolds number for various inlet swirl intensities. The report also provides a detailed literature survey that summarizes all the experimental and computational work in the area of duct flows.

  3. Hepatocellular carcinoma localized in the bile duct lumen: two case report

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Kyeung Kug; Chang, Jay Chun [Yeungnam Univ. School of Medicine, Seoul (Korea, Republic of)

    1998-10-01

    Intrabile duct tumor growth of hepatocellular carcinoma is an uncommon manifestation, but intraluminal bile duct hepatocellular carcinoma without primary hepatic parenchymal lesions is extremely rare. To our knowledge, only a few case reports have been published. We encountered two cases of primary hepatocellular carcinoma arising in the bile duct;serum alpha-fetoprotein levels were within the normal limits. Both showed the following characteristic radiologic features: (1) Cholangiography revealed filling defects within the dilated bile duct; (2) two-phase abdominal CT showed enhancement during the arterial-dominant phase and washout during the tissue equilibrium phase, as in typical HCC; and (3) hepateic arteriography revealed hypervascular tumor staining. Surgery was performed and the resected specimen showed no detectable primary hepatic parenchymal mass;on the basis of the pathologic finding, intraluminal bile duct hepatocellular carcinoma was confirmed. We cautiously assume that this peculiar type of HCC may arise primarily from bile duct mucosa.=20.

  4. Clinical and cholangiographic evaluation of bile duct carcinoma

    International Nuclear Information System (INIS)

    Park, Yeon Won; Kim, So Seon; Kim, Ho Joon; Joh, Young Duk; Chun, Byung Hee

    1986-01-01

    40 cases of bile duct carcinoma gathered over a 6-year period at Kosin Medical College were reviewed and their clinical and cholangiographic findings were as follows: 1. There were 29 males and 11 females (the ratio of men to women, 2.6:1) ranging from 37 to 74 years of age. The majority (70% of cases) were in 4th and 5th decades. 2. Clinical symptoms and signs: jaundice in 95%, RUQ or epigastric pain in 75%, pruritus in 52.5%, dark urine in 35%, weight loss in 32.5%, fever and chills in 22.5%, clay colored stool in 12.5%, and palpable mass in 12.5%. 3. Lab. findings: elevated serum total bilirubin (above 20.0mg% in 45%, 10.0-19.9mg% in 22.5%, 5.0-9.9mg% in 20%, 1.3-4.9mg% in 5%), elevated alkaline phosphatase in 95%. Clonorchiasis were noted in 17.5%. 4. Histologic findings were adenocarcinoma in most cases. 5. The location of bile duct carcinoma were common hepatic duct in 35%, common bile duct in 32.5%, porta hepatic in 12.5%, junction with cystic duct in 10% and diffuse form in 10%. 6. In 33 cases, PTC or post-operative cholangiographic examination were done. And the most frequent findings were dilatation of the proximal bile duct and abrupt narrowing or complete obstruction of distal lumen. In 27 cases (82%), complete obstruction of bile duct were noted. Attempts were made to analyze the type of obstruction: Constricted type in 39%, Nipple type in 18%, round or flat type (smooth or slightly irregular) in 15%, and serrated type in 9%. Incomplete obstruction were noted in 6 cases (18%). Among them, abrupt narrowing of lumen was noted in 9% and diffuse narrowing in 9%. 7. ERCP was done in 7 cases. Findings were: constricted type in 42.6%, constricted and slightly irregular type in 14.3%, downward convexity in 14.3%, diffuse irregular narrowing in 14.3% and intraluminal filing defect in 14.3%.

  5. Conservative Treatment for Cystic Duct Stenosis in a Child

    Directory of Open Access Journals (Sweden)

    Marco Gasparetto

    2013-01-01

    Full Text Available Introduction. Few cases of common bile duct stenosis have been reported in the literature, and observations of strictures in the cystic duct are even more rare. Surgical cholecystectomy is the treatment needed in most cases of gallbladder hydrops. This paper describes the diagnosis and successful medical treatment of a rare pediatric case of cystic duct stenosis and gallbladder hydrops. Case Report. A formerly healthy one-year-old girl was admitted with colicky abdominal pain. Blood tests were normal, except for an increase in transaminases. Abdominal ultrasound excluded intestinal intussusception and identified a distended gallbladder with biliary sludge. MR cholangiography revealed a dilated gallbladder containing bile sediment and no detectable cystic duct, while the rest of the intra- and extrahepatic biliary tree and hepatic parenchyma were normal. This evidence was consistent with gallbladder hydrops associated with cystic duct stenosis. The baby was treated with i.v. hydration, corticosteroids, antibiotics, and ursodeoxycholic acid. Her general condition rapidly improved, with no further episodes of abdominal pain and normalization of liver enzymes. This allowed to avoid cholecystectomy, and the child is well 1.5 years after diagnosis. Conclusions. Although cholecystectomy is usually necessary in case of gallbladder hydrops, our experience suggests that surgical procedures can be avoided when the distension is caused by a cystic duct stenosis.

  6. Relationship Between Bile Duct Reconstruction and Complications in Living Donor Liver Transplantation.

    Science.gov (United States)

    Miyagi, S; Kawagishi, N; Kashiwadate, T; Fujio, A; Tokodai, K; Hara, Y; Nakanishi, C; Kamei, T; Ohuchi, N; Satomi, S

    2016-05-01

    In living donor liver transplantation (LDLT), the recipient bile duct is thin and short. Bile duct complications often occur in LDLT, with persistent long-term adverse effects. Recently, we began to perform microsurgical reconstruction of the bile duct. The purpose of this study was to investigate the relationship between bile duct reconstruction methods and complications in LDLT. From 1991 to 2014, we performed 161 LDLTs (pediatric:adult = 90:71; left lobe:right lobe = 95:66). In this study, we retrospectively investigated the initial bile duct complications in LDLT and performed univariate and multivariate analyses to identify the independent risk factors for complications. The most frequent complication was biliary stricture (9.9%), followed by biliary leakage (6.8%). On univariate and multiple logistic regression analysis, the independent risk factors for biliary stricture were bile leakage (P = .0103) and recurrent cholangitis (P = .0077). However, there were no risk factors for biliary leakage on univariate analysis in our study. The reconstruction methods (hepaticojejunostomy or duct-to-duct anastomosis) and reconstruction technique (with or without microsurgery) were not risk factors for biliary stricture and leakage. In this study, the most frequent complication of LDLT was biliary stricture. The independent risk factors for biliary stricture were biliary leakage and recurrent cholangitis. Duct-to-duct anastomosis and microsurgical reconstruction of the bile duct were not risk factors for biliary stricture and leakage. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. DETECTION OF WIDESPREAD HOT AMMONIA IN THE GALACTIC CENTER

    International Nuclear Information System (INIS)

    Mills, E. A. C.; Morris, M. R.

    2013-01-01

    We present the detection of metastable inversion lines of ammonia (NH 3 ) from energy levels high above the ground state. We detect these lines in both emission and absorption toward 15 of 17 positions in the central 300 pc of the Galaxy. In total, we observe seven metastable transitions of NH 3 : (8, 8), (9, 9), (10, 10), (11, 11), (12, 12), (13, 13) and (15, 15), with energies (in Kelvins) ranging from 680 to 2200 K. We also mapped emission from NH 3 (8, 8) and (9, 9) in two clouds in the Sgr A complex (M-0.02–0.07 and M-0.13–0.08), and we find that the line emission is concentrated toward the dense centers of these molecular clouds. The rotational temperatures derived from the metastable lines toward M-0.02–0.07 and M-0.13–0.08 and an additional cloud (M0.25+0.01) range from 350 to 450 K. Similarly highly-excited lines of NH 3 have previously been observed toward Sgr B2, where gas with kinetic temperatures of ∼600 K had been inferred. Our observations show that the existence of a hot molecular gas component is not unique to Sgr B2, but rather appears common to many Galactic center molecular clouds. In M-0.02–0.07, we find that the hot NH 3 contributes ∼10% of the cloud's total NH 3 column density, and further, that the hot NH 3 in this cloud arises in gas which is extended or uniformly distributed on ∼>10 arcsec scales. We discuss the implications of these constraints upon the nature of this hot gas component. In addition to the detection of hot metastable NH 3 line emission, we also detect for the first time emission from nonmetastable inversion transitions of NH 3 in both M-0.02–0.07 and M-0.13–0.08

  8. An experimental study on microcholangiographic manifestation in extrahepatic bile duct obstruction

    International Nuclear Information System (INIS)

    Lee, Yul; Kang, Heung Sik; Park, Jae Hyung; Kim, Chu Wan

    1987-01-01

    Microcholangiographic using microbarium was done for radiological observation of the morphology of intrahepatic microbiliary system and its charge after extrahepatic bile duct obstruction. Regurgitation of microbarium into the systemic circulation was also observed. Extrahepatic bile ducts of 40 rabbits were ligated and microcholangiography was done just after ligation, after 1 day, 3 days and 5 days. Injection pressure of microbarium was 58 cm H 2 O in 20 rabbits and 93 cm H 2 O in another 20 rabbits. Histologic findings of the liver was compared with microcholangiographic findings. The results were as follows: 1. In microcholangiography, interlobular bile ducts and ductules were well noted, but bile canaliculi were not visible. 2. After extrahepatic bile duct ligation, ductules and small interlobular bile ducts were tortuously dilated and proliferated. These findings progressed according as the time after extrahepatic bile duct ligation especially between 1 and 2 days. 3. Microbarium was regurgitated into hepatic sinusoids from a portal tract due to rupture of interlobular bile ducts or ductules, and this was observed only in limited portions of sample tissue sections, but could be found in most of 40 rabbits. From the above results, the morphology of intrahepatic microbiliary system and its change after extrahepatic bile duct obstruction could be radiologically observed with microcholangiography, so this technique could be used for experimental study about the biliary system.

  9. Hot Ductility Behavior of a Peritectic Steel during Continuous Casting

    OpenAIRE

    Arıkan, Mustafa

    2015-01-01

    Hot ductility properties of a peritectic steel for welded gas cylinders during continuous casting were studied by performing hot tensile tests at certain temperatures ranging from 1200 to 700 °C for some cooling rates by using Gleeble-3500 thermo-mechanical test and simulation machine in this study. The effects of cooling rate and strain rate on hot ductility were investigated and continuous casting process map (time-temperature-ductility) were plotted for this material. Reduction of area ...

  10. Related issues in repair of bile duct injury and traumatic biliary stricture

    Directory of Open Access Journals (Sweden)

    WANG Shuguang

    2017-02-01

    Full Text Available Inappropriate treatment of bile duct injury and traumatic biliary stricture may cause serious consequences such as recurrent cholangitis, formation of hepatolithiasis, and biliary cirrhosis. This article elaborates on the influencing factors for the effect of the repair of bile duct injury and traumatic biliary stricture, repair principles, timing of repair or reconstruction, and related methods and techniques. It is pointed out that if there is no significant local infection and the bile duct wall defect is <2 cm, end-to-end anastomosis should be used for repair; if the bile duct wall defect is >2 cm, Roux-en-Y hepaticojejunostomy should be used for reconstruction. If the upper wall of the bile duct had a large defect and the lower wall has an integral structure, pedicled umbilical vein graft, pedicled jejunal wall seromuscular flap, or gastric wall seromuscular flap should be used for repair. The patients with severe congestion and edema at the site of injury should be treated with sufficient external drainage of the injured bile duct and then selective repair or reconstruction. Patients with hepatic duct stenosis in the liver lobe or hepatic segments and liver tissue atrophy can be treated with hepalobectomy or segmental hepatectomy. The key to successful repair is exposure and removal of high hilar bile duct stricture, while segmental hepatectomy of the Ⅳb segment can fully expose the left and right hepatic pedicles and help with the incision of the left and right hepatic ducts and secondary hepatic ducts, and therefore, it is a good method for exposing high bile duct stricture.

  11. Delayed hot spots in a low energy plasma focus

    International Nuclear Information System (INIS)

    Rout, R.K.; Shyam, A.

    1991-01-01

    In a low energy Mather-type plasma focus device, hot spots having temperature in the range of few keV have been observed even 1 μs after the pinch disintegration and in regions away from the pinch area. These hot spots are perhaps created by the thermal runaway due to temperature fluctuations in the background gas. (author). 12 refs., 6 figs

  12. Radiological study on the change of duct-ligated parotid gland

    International Nuclear Information System (INIS)

    Ohnishi, Takashi

    1994-01-01

    The change of the parotid gland with time following ligation of the main duct was investigated. The duct-ligated parotid gland in rabbit was examined by salivary gland scintigraphy with 99m Tc-pertechnetate ( 99m TcO 4 - ), sialography and microscopic observation. The third day after ligation of the main duct, the outward form of the parotid gland on the static scintigram was not well-defined. On the seventh day, 99m TcO 4 - accumulation was decreased slightly. On the 14th day, atrophy of the parotid gland occurred. The degree of atrophy produced by ligation increases as the duration of the ligation increases. On the 42nd day, the presence of the parotid gland was not recorded practically. The main duct was dilated on the third day. On the seventh day, the intraglandular ducts were bent and strictured. Disappearance of the peripheral duct and atrophy of the parotid gland parenchyma was observed. On microscopic observation, the intraglandular tributaries and the lumen were dilated on the third day. And the reticular fiber was observed that was irregularly formed in parts. The acinar cells were pressed by large and small dilated lumen on the seventh day. On the 14th day, the collagenous fiber around the acini and the duct was increased still more. In addition, fibrosis of the lobule interspace was observed. The degree of atrophy of the acini and lobule was increased maximally on the 42nd day. These results of the salivary gland scintigraphy closely connected with sialograms and microscopic findings. The parotid gland tissue decreases and changings of the duct system were indicated by these imaging methods in detail. (author)

  13. Modified duval procedure for small-duct chronic pancreatitis without head dominance.

    Science.gov (United States)

    Oida, Takatsugu; Aramaki, Osamu; Kano, Hisao; Mimatsu, Kenji; Kawasaki, Atsushi; Kuboi, Youichi; Fukino, Nobutada; Kida, Kazutoshi; Amano, Sadao

    2011-01-01

    In the case of small-duct chronic pancreatitis, surgery for pain relief is broadly divided into resection and drainage procedures. These procedures should be selected according to the location of dominant lesion, diameter of the pancreatic duct and extent of the disease. The appropriate procedure for the treatment of small-duct chronic pancreatitis, especially small-duct chronic pancreatitis without head dominance, remains controversial. We developed the modified Duval procedure for the treatment of small-duct chronic pancreatitis without head dominance and determined the efficacy of this procedure. We retrospectively studied 14 patients who underwent surgical drainage with or without pancreatic resection for chronic pancreatitis with small pancreatic duct (Puestow procedure group and the modified Duval procedure group. No complications occurred in the modified Duval group. In the modified Puestow procedure group, complete and partial pain relief were observed in 62.5%, and 37.5% of patients respectively. In contrast, complete pain relief was observed in all the patients in the modified Duval procedure group. Our modified Duval procedure is useful and should be considered the appropriate surgical technique for the treatment of small-duct chronic pancreatitis without head dominance.

  14. A simple method to calculate the neutron flow through full ducts

    International Nuclear Information System (INIS)

    Faik Ouahab, Z.; Jehouani, A.; Ghassoun, J.; Senhou, N.; Groetz, J.E.

    2010-01-01

    Summary of a study of assessment of the probability for neutrons to be guided in a full duct with a square cross section and doubly bent. Two software have been developed, based on the Monte Carlo simulation, to compute the neutron transmission probability at the end of the duct. Results are in good agreement with that obtained with the MCNP-5 code. The neutron flow and probability at the duct end have been determined for different materials and different duct dimensions

  15. Intracellular pH in rat pancreatic ducts

    DEFF Research Database (Denmark)

    Novak, I; Hug, M; Greger, R

    1997-01-01

    In order to study the mechanism of H+ and HCO3- transport in a HCO3- secreting epithelium, pancreatic ducts, we have measured the intracellular pH (pHi) in this tissue using the pH sensitive probe BCECF. We found that exposures of ducts to solutions containing acetate/acetic acid or NH4+/NH3...... buffers (20 mmol/l) led to pHi changes in accordance with entry of lipid-soluble forms of the buffers, followed by back-regulation of pHi by duct cells. In another type of experiment, changes in extracellular pH of solutions containing HEPES or HCO3-/CO2 buffers led to significant changes in pHi that did....... Under some conditions, these exchangers can be invoked to regulate cell pH....

  16. Salivary duct carcinoma: a Danish national study

    DEFF Research Database (Denmark)

    Breinholt, Helle; Elhakim, Mohammad Talal; Godballe, Christian

    2016-01-01

    BACKGROUND: To present the first national series of salivary duct carcinoma patients, including survival rates and an analysis of prognostic factors. METHODS: By merging three Danish nationwide registries that encompass an entire population, 34 patients diagnosed with salivary duct carcinoma from......-rank test. RESULTS: Salivary duct carcinoma showed an incidence of 0.04/100.000 inhabitants/year. Distant recurrence was seen in 52% of patients. Five-year overall survival, disease-specific survival and recurrence-free survival were 32%, 42% and 35%, respectively. Univariate analyses suggested that overall...... carcinoma incidence averages to two episodes per year in the entire Kingdom of Denmark. With half of patients in this study experiencing distant recurrences and only a third surviving at 5 years, prognosis is dismal. Advanced overall stage, vascular invasion and involved resection margins all seem...

  17. Scintigraphy of cysts of the common bile duct in children

    International Nuclear Information System (INIS)

    Mironov, S.P.; Akopyan, V.G.; Murieva, Z.D.; Tumanyan, G.T.; Mironova, E.S.

    1984-01-01

    Cyst of the common bile duct, the most frequent variant of cystic dilatation of the extrahepatic biliary tract, represents a serious diagnostic problem. 13 children with cysts of the common bile duct were studied by the method of dynamic scintigraphy with sup(99m)Tc-HIDA. The scintigraphic picture was characterized by the following signs: sacculated or spheroidal dilatation of the common bile duct, dilatation of the left or both lobular bile ducts, absence of the gall bladder visualization. Change of indicators of the hepatic function and the time of interstinal visualization reflects both the disorder of distal parts permeability and the degree of cyst drainage. An experience of radioisotropic cholegraphy application reveals, that the efficiency of preoperational diagnosis of cysts of the common bile duct increases as a result of the more accurate evaluation of the dynamic of improvement of absorptive-excretory hepatic function after different variants of operations

  18. Effects of explosion-generated shock waves in ducts

    International Nuclear Information System (INIS)

    Busby, M.R.; Kahn, J.E.; Belk, J.P.

    1976-01-01

    An explosion in a space causes an increase in temperature and pressure. To quantify the challenge that will be presented to essential components in a ventilation system, it is necessary to analyze the dynamics of a shock wave generated by an explosion, with attention directed to the propagation of such a wave in a duct. Using the equations of unsteady flow and shock tube theory, a theoretical model has been formulated to provide flow properties behind moving shock waves that have interacted with various changes in duct geometry. Empirical equations have been derived to calculate air pressure, temperature, Mach number, and velocity in a duct following an explosion

  19. Demonstration tests for HTGR fuel elements and core components with test sections in HENDEL

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Yoshiaki; Hino, Ryutaro; Inagaki, Yoshiyuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1995-03-01

    In the fuel stack test section (T{sub 1}) of the Helium Engineering Demonstration Loop (HENDEL), thermal and hydraulic performances of helium gas flows through a fuel rod channel and a fuel stack have been investigated for the High-Temperature Engineering Test Reactor (HTTR) core thermal design. The test data showed that the turbulent characteristics appearing in the Reynolds number above 2000: no typical behavior in the transition zone, and friction factors and heat transfer coefficients in the fuel channel were found to be higher than those in a smooth annular channel. Heat transfer behavior of gas flow in a fuel element channel with blockage and cross-flow through a gap between upper and lower fuel elements stacked was revealed using the mock-up models. On the other hand, demonstration tests have been performed to verify thermal and hydraulic characteristics and structural integrity related to the core bottom structure using a full-scale test facility named as the in-core structure test section (T{sub 2}). The sealing performance test revealed that the leakage of low-temperature helium gas through gaps between the permanent reflector blocks to the core was very low level compared with the HTTR design value and no change of the leakage flow rate were observed after a long term operation. The heat transfer tests including thermal transient at shutdown of gas circulators verified good insulating performance of core insulation structures in the core bottom structure and the hot gas duct; the temperature of the metal portion of these structure was below the design value. Examination of the thermal mixing characteristics indicated that the mixing of the hot helium gas started at a hot plenum and finished completely at downstream of the outlet hot gas duct. The present results obtained from these demonstration tests have been practically applied to the detailed design works and licensing procedures of the HTTR. (J.P.N.) 92 refs.

  20. Heating, Ventilation, and Air Conditioning Design Strategy for a Hot-Humid Production Builder

    Energy Technology Data Exchange (ETDEWEB)

    Kerrigan, P. [Building Science Corporation, Somerville, MA (United States)

    2014-03-01

    Building Science Corporation (BSC) worked directly with the David Weekley Homes - Houston division to develop a cost-effective design for moving the HVAC system into conditioned space. In addition, BSC conducted energy analysis to calculate the most economical strategy for increasing the energy performance of future production houses in preparation for the upcoming code changes in 2015. This research project addressed the following questions: 1. What is the most cost effective, best performing and most easily replicable method of locating ducts inside conditioned space for a hot-humid production home builder that constructs one and two story single family detached residences? 2. What is a cost effective and practical method of achieving 50% source energy savings vs. the 2006 International Energy Conservation Code for a hot-humid production builder? 3. How accurate are the pre-construction whole house cost estimates compared to confirmed post construction actual cost?

  1. Occlusion of the cystic duct by electrocoagulation: A radiologic technique

    International Nuclear Information System (INIS)

    Becker, C.D.; Quenville, W.F.; Burhenne, H.J.

    1987-01-01

    Chemical dissolution and extracorporeal shock wave lithotripsy are promising new methods for the treatment of cholelithiasis without cholecystectomy. Nonsurgical defunctionalization of the gallbladder is now required to prevent recurrent stone formation. The authors consider cystic duct occlusion to be the first step. Ten domestic pigs underwent transcatheter electrocoagulation of the cystic duct via a cholecystostomy under fluoroscopic control. Stricture formation was followed by complete cystic duct occlusion in all ten cases. After a follow-up period ranging from 2 to 17 weeks (mean, 13 weeks), the animals were killed. Histologic studies demonstrated that complete obliteration of the cystic duct lumen was due to fibrous scar formation

  2. The role of B/D ratio and A/D ratio to defferentiate malignancy from benignancy in distal extrahepatic bile duct obstruction

    International Nuclear Information System (INIS)

    Rhim, Hyun Chul; Baek, JUng Hwan; Jeon, Eui Yong; Koh, Byung Hee; Cho, On Koo; Kim, Young Hwan

    1994-01-01

    To determine wheter bilirubin/extrahepatic bile duct diameter ratio(B/D ratio) or alkalinephosphatase/extrahepatic bile duct diameter ratio (A/D ratio) can be used to differentiate malignant from benigndisease in distal extrahepatic bile duct obstruction during ultrasonographic examination. We retrospectively reviewed the sonograms and laboratory data of 100 patients with obstructive jaundice (benign : n=50, malignant: : n=50). The diagnosis was confirmed either surgically (n=66) or clinically (n=34). The B/D ratio and A/D radio were calculated by means of dividing total bilirubin (mg/dl) and alkaline phosphatase (I.U.)respectively by maximum extrahepatic bile duct diameter(mm) on ultrasonogram. Significant difference in B/D ratio was found between the benignancy (0.28+0.25) and malignancy (0.98+0.84) groups (P<0.001). Significant difference in A/D ratio was also found between the benignancy (15.00+10.22) and malignancy (32.44+30.28) groups(P<0.001) Accuracies to predict malignancy according to criteria of B/D and A/D ratios were less than 75% and 65%respectively. On the other hand, the positive predictive value and specificity were relatively high. The B/D ratio and A/D ratio calculated from ultrasonograms can be used as a valuable screening index todifferentiate malignancy from benignacy in patients with distal extrahepatic bile duct obstruction, especially when the sonography is difficult because of the interposition of bowel gas or obesity

  3. Washing Habits and Machine with Intake of hot and cold Water

    DEFF Research Database (Denmark)

    Christensen, Bente Lis; Nørgaard, Jørgen

    1997-01-01

    with slightly adapted washing habits, or 17% of normal today. If the heat is supplied from combined heat and power production as in the actual experiment, CO2-emission is reduced by 81%. With hot water from oil or gas heaters the reduction will be slightly lower, while with solar hot water it will be larger.......Domestic washing machines typically spend around 80% of the electricity on heating water. Most of this can be replaced by more appropriate heat sources like district heat from combined heat and power production, or gas heating system. In recent years some washing machine manufacturers have marketed...... machines which can take in both hot and cold water and mix it to the temperature wanted. Such one machine has been tested in daily household use over 5 months, with habits of very few hot water washes. The result is an electricity consumption corresponding to 67 kWh per year for an average household...

  4. WLAN Hot Spot services for the automotive and oil industries :a business analysis Or : "Refuel the car with petrol and information, both ways at the gas station"

    NARCIS (Netherlands)

    L-F. Pau (Louis-François); M.H.P. Oremus

    2003-01-01

    textabstractWhile you refuel for gas ,why not refuel for information or download vehicle data ? This paper analyzes in extensive detail the user segmentation by vehicle usage , service offering , and full business models from WLAN hot spot services delivered to vehicles (private, professional ,

  5. Forced convection heat transfer correlation for finned plates in a duct

    International Nuclear Information System (INIS)

    Chae, Myeong-Seon; Moon, Je-Young; Chung, Bum-Jin

    2014-01-01

    Forced convection heat transfer experiments were conducted for plate-fin in a duct using various fin spacing, fin height, duct width, Reynolds number for Prandtl numbers 2,014. Based upon analogy concept, mass transfer rate were measured instead of heat transfer rates. The heat transfer rates were enhanced with the increase of fin height and decrease of fin spacing as they increase the heat transfer area. Meanwhile, heat transfer rates were impaired with the increase of the duct width as the bypass flows increased to tip clearance region. Forced convection heat transfer correlations were developed for laminar and turbulent flow conditions and for narrow and wide ducts. The work draws attention to the tip clearance on the heat transfer of the finned plate in a duct. (author)

  6. HAARP-Induced Ionospheric Ducts

    International Nuclear Information System (INIS)

    Milikh, Gennady; Vartanyan, Aram

    2011-01-01

    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.

  7. Laparoscopic bile duct injury: understanding the psychology and heuristics of the error.

    Science.gov (United States)

    Dekker, Sidney W A; Hugh, Thomas B

    2008-12-01

    Bile duct injury is an important unsolved problem of laparoscopic cholecystectomy, occurring with unacceptable frequency even in the hands of experienced surgeons. This suggests that a systemic predisposition to the injury is intrinsic to cholecystectomy and indicates that an analysis of the psychology and heuristics of surgical decision-making in relation to duct identification may be a guide to prevention. Review of published reports on laparoscopic bile duct injury from 1997 to 2007 was carried out. An analysis was also carried out of the circumstances of the injuries in 49 patients who had transection of an extrahepatic bile duct and who were referred for reconstruction or were assessed in a medicolegal context. Special emphasis was placed on identifying the possible psychological aspects of duct misidentification. Review of published work showed an emphasis on the technical aspects of correct identification of the cystic duct, with few papers addressing the heuristics and psychology of surgical decision-making during cholecystectomy. Duct misidentification was the cause of injury in 42 out of the 49 reviewed patients (86%). The injury was not recognized at operation in 70% and delay in recognition persisted into the postoperative period in 57%. Underestimation of risk, cue ambiguity and visual misperception ('seeing what you believe') were important factors in misidentification. Delay in recognition of the injury is a feature consistent with cognitive fixation and plan continuation, which help construct and sustain the duct misidentification during the operation and beyond. Changing the 'culture' of cholecystectomy is probably the most effective strategy for preventing laparoscopic bile duct injury, especially if combined with new technical approaches and an understanding of the heuristics and psychology of the duct misidentification error. Training of surgeons for laparoscopic cholecystectomy should emphasize the need to be alert for cues that the incorrect

  8. Hydrogen sulfide removal from hot coal gas by various mesoporous silica supported Mn2O3 sorbents

    International Nuclear Information System (INIS)

    Zhang, Z.F.; Liu, B.S.; Wang, F.; Wang, W.S.; Xia, C.; Zheng, S.; Amin, R.

    2014-01-01

    Graphical abstract: - Highlights: • Mn 2 O 3 /KIT-1 presented the best desulfurization performance at 600–850 °C. • High sulfur capacity of Mn 2 O 3 /KIT-1 correlated closely with 3-D channel of KIT-1. • Desulfurization character depended strongly on framework structure of sorbents. • High steam content suppressed greatly the occurrence of sulfidation reaction. - Abstract: A series of 50 wt% Mn 2 O 3 sorbents was prepared using various mesoporous silica, MCM-41, HMS, and KIT-1 as support. The influence of textural parameters of mesoporous silica, especially type of channel on the desulfurization performance of Mn 2 O 3 sorbents was investigated at 600–850 °C using hot coal gas containing 0.33 vol.% H 2 S. The fresh and used sorbents were characterized by means of N 2 -adsorption, x-ray diffraction (XRD), high resolution transmission microscopy (HRTEM) and H 2 temperature- programmed reduction (H 2 -TPR) techniques. The results confirmed that the manganese oxide was dispersed highly in regular pore channel of the mesoporous supports due to high surface area. Compared with the Mn 2 O 3 /diatomite, all mesoporous silica supported Mn 2 O 3 sorbents exhibited high breakthrough sulfur capacity and a sharp deactivation rate after the breakthrough point. Compared to Mn 2 O 3 /MCM-41 and Mn 2 O 3 /HMS sorbent, the Mn 2 O 3 /KIT-1 showed better desulfurization performance because of the 3D wormhole-like channel. The high sulfur capacity of the Mn 2 O 3 /KIT-1 sorbent was maintained during the eight consecutive desulfurization-regeneration cycles. The Mn 2 O 3 /KIT-1 still presented high desulfurization activity when hot coal gas contained low steam (<5%)

  9. Design of a diagnostic residual gas analyzer for the ITER divertor

    Energy Technology Data Exchange (ETDEWEB)

    Klepper, C.C., E-mail: kleppercc@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169 (United States); Biewer, T.M.; Graves, V.B. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169 (United States); Andrew, P. [ITER Organisation, Route de Vinon-sur-Verdon, 13067 St. Paul-lez-Durance (France); Lukens, P.C. [US ITER Project Office, 1055 Commerce Park Dr #1, Oak Ridge, TN 37830 (United States); Marcus, C. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169 (United States); Shimada, M., E-mail: shimada.michiya@jaea.go.jp [ITER Organisation, Route de Vinon-sur-Verdon, 13067 St. Paul-lez-Durance (France); Hughes, S.; Boussier, B. [ITER Organisation, Route de Vinon-sur-Verdon, 13067 St. Paul-lez-Durance (France); Johnson, D.W. [US ITER Diagnostics Office, Princeton Plasma Physics Laboratory, Princeton, NJ 08540 (United States); Gardner, W.L. [US ITER Project Office, 1055 Commerce Park Dr #1, Oak Ridge, TN 37830 (United States); Hillis, D.L. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169 (United States); Vayakis, G.; Walsh, M. [ITER Organisation, Route de Vinon-sur-Verdon, 13067 St. Paul-lez-Durance (France)

    2015-10-15

    Highlights: • The divertor DRGA for ITER will measure neutral gas composition in the pumping ducts during plasma. • System must respond in timescales relevant to compositional changes in the divertor plasma. • It is shown that times can vary from 1 to 6 s for fuel (H2, D2, T2) up to 50 s for He (fusion reaction ash). • It is shown that present design delivers ∼ 1 s response even via an 8m long sampling pipe sampling. • Response time validated with VacTran{sup ®} over anticipated the 0.1–10 Pa pressure range in the ducts. - Abstract: One of the ITER diagnostics having reached an advanced design stage is a diagnostic RGA for the divertor, i.e. residual gas analysis system for the ITER divertor, which is intended to sample the divertor pumping duct region during the plasma pulse and to have a response time compatible with plasma particle and impurity lifetimes in the divertor region. Main emphasis is placed on helium (He) concentration in the ducts, as well as the relative concentration between the hydrogen isotopes (mainly in the form of diatomic molecules of H, D, and T). Measurement of the concentration of radiative gases, such as neon (Ne) and nitrogen (N{sub 2}), is also intended. Numerical modeling of the gas flow from the sampled region to the cluster of analysis sensors, through a long (∼8 m long, ∼110 mm diameter) sampling pipe originating from a pressure reducing orifice, confirm that the desired response time (∼1 s for He or D{sub 2}) is achieved with the present design.

  10. Critical temperature of liquid-gas phase transition for hot nuclear matter and three-body force effect

    International Nuclear Information System (INIS)

    Zuo Wei; Lu Guangcheng; Li Zenghua; Luo Peiyan; Chinese Academy of Sciences, Beijing

    2005-01-01

    The finite temperature Brueckner-Hartree-Fock (FTBHF) approach is extended by introducing a microscopic three-body force. Within the extended approach, the three-body force effects on the equation of state of hot nuclear matter and its temperature dependence have been investigated. The critical properties of the liquid-gas phase transition of hot nuclear matter have been calculated. It is shown that the three-body force provides a repulsive contribution to the equation of state of hot nuclear matter. The repulsive effect of the three-body force becomes more pronounced as the density and temperature increase and consequently inclusion of the three-body force contribution in the calculation reduces the predicted critical temperature from about 16 MeV to about 13 MeV. By separating the contribution originated from the 2σ-exchange process coupled to the virtual excitation of a nucleon-antinucleon pair from the full three-body force, the connection between the three-body force effect and the relativistic correction from the Dirac-Brueckner-Hartree-Fock has been explored. It turns out that the contribution of the 2σ-N(N-bar) part is more repulsive than that of the full three-body force and the calculated critical temperature is about 11 MeV if only the 2σ-N(N-bar) component of the three-body force is included which is lower than the value obtained in the case of including the full three-body force and is close to the value predicted by the Dirac-Brueckner-Hartree-Fock (DBHF) approach. Our result provides a reasonable explanation for the discrepancy between the values of critical temperature predicted from the FTBHF approach including the three-body force and the DBHF approach. (authors)

  11. Gas converter. Gaswandler

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmann, A

    1984-09-27

    A gas converter is proposed for carbonisation gas containing hydrocarbons, consisting of a bricked shaft, which has a free combustion chamber and a solid bed of bulk grainy material with partly burnt hot carbonisation gases flowing through it as the lower boundary of this combustion chamber, in the upper part of which a hot reaction zone at about 1000 to 1200/sup 0/C is formed and which has a cracked gas extraction below the solid bed and an ash outlet. The solid bed is arranged at an angle to the vertical. The shaft has a solid material outlet for the bed material no longer capable of taking part in the reaction on the wall going obliquely downwards and a solid material inlet for new bulk bed material on the opposite wall going obliquely upwards.

  12. Abnormalities of intrahepatic bile ducts in extrahepatic biliary atresia.

    Science.gov (United States)

    Raweily, E A; Gibson, A A; Burt, A D

    1990-12-01

    The infantile cholangiopathies are a group of conditions associated with neonatal jaundice, which include extrahepatic biliary atresia, paucity of intra-hepatic bile ducts and disorders associated with persistence of fetal biliary structures, the so-called ductal plate malformations. Although previously regarded as distinct entities, it has recently been suggested that they may represent parts of a disease spectrum in which the principal process is one of bile duct destruction, the morphological manifestations in individual cases being influenced by the stage of intra-uterine development at which such injury occurs and by the site within the biliary system at which there is maximum damage. To further examine this concept, we have studied liver biopsy specimens from 37 neonates with extrahepatic biliary atresia, with particular reference to abnormalities of the intrahepatic bile ducts. Paucity of intrahepatic ducts, defined as a bile duct: portal tract ratio of less than 0.9, was identified in six cases (16.2%). In eight cases (21.6%) we found concentric tubular ductal structures similar to those observed in ductal plate malformations. In one case, both abnormalities could be demonstrated. Our findings support the concept that there is overlap between the various types of infantile cholangiopathy.

  13. Primary Follicular Lymphoma of the Common Bile Duct Mimicking Cholangiocarcinoma

    Directory of Open Access Journals (Sweden)

    Khaled Youssef Elbanna

    2014-01-01

    Full Text Available Primary non-Hodgkin′s lymphoma of the common bile duct is extremely rare. We present a case with history of inflammatory bowel disease and clinical manifestations of obstructive jaundice. Abdominal magnetic resonance imaging with magnetic resonance cholangiopancreatography (MRCP was done and demonstrated tight stricture at the middle part of common bile duct, and radiological findings were supportive of extra-hepatic cholangiocarcinoma. Whipple′s procedure was performed and the case was histopathologically proven to be non-Hodgkin′s lymphoma of follicular subtype involving the common bile duct. Lymphoma of the hepatobiliary system is usually present as secondary manifestation of systemic malignant lymphoma. However, primary malignant lymphomas arising from the hepatobiliary tree are extremely rare. The radiological appearance of common bile duct lymphoma is very similar to cholangiocarcinoma, making preoperative diagnosis very difficult, as in our present case. We also compare the imaging findings of our case to those seen in reported cases of follicular lymphoma of the common bile duct.

  14. Spontaneous common bile duct perforation—A rare clinical entity

    Directory of Open Access Journals (Sweden)

    Melissa Amberger

    Full Text Available Introduction: Spontaneous common bile duct perforation is an uncommon clinical entity in both adults and children. Few case reports have been published since the first clinical description in 1882. Our work has been reported in line with SCARE criteria. Presentation of case: Herein, we describe the case of a 28 year-old female who suffered spontaneous common bile duct perforation while admitted for choledocholithiasis. Discussion: The perforation occurred while in-hospital, and extensive imaging and laboratory tests characterized the disease in detail. To our knowledge, this is the first report of spontaneous common bile duct perforation witnessed from pre-perforation through definitive management. Conclusion: Physicians and Surgeons should seek out this uncommon diagnosis in the patient with suspected Choledocholithiasis who suddenly become peritoneal on physical exam so that definitive care can be expedited. Keywords: Common bile duct, Biliary peritonitis, Choledocholithiasis

  15. Bile Duct Cancer (Cholangiocarcinoma) Symptoms, Tests, Prognosis, and Stages (PDQ®)—Patient Version

    Science.gov (United States)

    Bile duct cancer, or cholangiocarcinoma, is rare. Bile ducts are tubes that carry bile between the liver, gallbladder, and small intestine. Bile duct cancer can occur in the intrahepatic, perihilar (Klatskin tumor), or distal extrahepatic area. Learn about tests to diagnose and the stages of bile duct cancer.

  16. Evidence for a Na+-Ca2+ exchanger in rat pancreatic ducts

    DEFF Research Database (Denmark)

    Hug, M; Pahl, C; Novak, I

    1996-01-01

    Only recently has it been recognized that intracellular Ca2+ is an important cellular mediator in pancreatic ducts. The aim of the present study was to characterize the Ca2+ efflux pathway in ducts freshly prepared from rat pancreas. Lowering of extracellular Na+ concentration resulted in a signi......Only recently has it been recognized that intracellular Ca2+ is an important cellular mediator in pancreatic ducts. The aim of the present study was to characterize the Ca2+ efflux pathway in ducts freshly prepared from rat pancreas. Lowering of extracellular Na+ concentration resulted...

  17. Design requirement on KALIMER blanket fuel assembly duct

    International Nuclear Information System (INIS)

    Hwang, Woan; Kang, H. Y.; Nam, C.; Kim, J. O.

    1998-03-01

    This document describes design requirements which are needed for designing the blanket fuel assembly duct of the KALIMER as design guidance. The blanket fuel assembly duct of the KALIMER consists of fuel rods, mounting rail, nosepiece, duct with pad, handling socket with pad. Blanket fuel rod consists of top end plug, bottom end plug with solid ferritic-martensitic steel rod and key way blanket fuel slug, cladding, and wire wrap. In the assembly, the rods are in a triangular pitch array, and the rod bundle is attached to the nosepiece with mounting rails. The bottom end of the assembly duct is formed by a long nosepiece which provides the lower restraint function and the paths for coolant inlet. This report contains functional requirements, performance and operational requirements, interfacing systems requirements, core restraint and interface requirements, design limits and strength requirements, system configuration and essential feature requirements, seismic requirements, structural requirements, environmental requirements, reliability and safety requirements, standard and codes, QA programs, and other requirements. (author). 20 refs., 4 figs

  18. Heat transfer in an asymmetrically heated duct, 2

    International Nuclear Information System (INIS)

    Satoh, Isao; Kurosaki, Yasuo

    1986-01-01

    The objective of this article is to study theoretically and experimentally the effects of nonuniform heating on turbulent heat transfer characteristics for flow in a horizontal rectangular duct ; a vertical side wall was uniformly heated, and the other wall were insulated. In our theoretical approach, the zero-equation model for turbulent eddy viscosity was employed. The effects of mesh size of finite difference on the calculation results were examined, and some refined compensation for wall temperatures and wall shear stresses by no use of fine mesh were proposed to reduce the calculation time. The heat transfer coefficients in thermally developing region for a nonuniformly heated duct obtained from numerical solutions are larger than the one for uniformly heated case. The buoyancy effects on heat transfer were evaluated. However, it was seen that the secondary flow due to buoyancy force was hardly expected to enhance heat transfer in a turbulent duct flow. Experiments were performed to measure the velocity and temperature profiles in a turbulent duct flow with a nonuniform heated wall. The experimental results were in good agreement with the theoretical ones. (author)

  19. Diagnosis of functional nasolacrimal duct obstruction using dacryoscintigraphy

    International Nuclear Information System (INIS)

    Lim, Hyun Wook; Sohn, Hyung Sun; Kim, Euy Neyng; Chung, Yong An; Kim, Sung Hoon; Chung, Soo Kyo

    2000-01-01

    To evaluate the value of dacryoscintigraphy in the assessment of patients with a clinical diagnosis of functional nasolacrimal duct obstruction. Dacryoscintigraphy was performed in symptomatic 35 lacrimal drainage systems in 18 patients (age range: 37 ∼76,8 males, 10 females) that were patent on syringing. Abnormalities were detected with dacryoscintigraphy in 75.8% of systems. The positive scintigrams were subdivided into those demonstrating prelacrimal sac delay (31.8%), delay at the lacrimal sac/junction (40.9%), or delay within the duct (27%). Dacryoscintigraphy is noninvasive useful technique in the assessment of the functional nasolacrimal duct obstruction and very sensitive at detecting abnormalities in patients with lid laxity caused by senile change and facial nerve palsy

  20. Time course of collagen peak in bile duct-ligated rats.

    Science.gov (United States)

    Tarcin, Orhan; Basaranoglu, Metin; Tahan, Veysel; Tahan, Gülgün; Sücüllü, Ilker; Yilmaz, Nevin; Sood, Gagan; Snyder, Ned; Hilman, Gilbert; Celikel, Cigdem; Tözün, Nurdan

    2011-04-28

    One of the most useful experimental fibrogenesis models is the "bile duct-ligated rats". Our aim was to investigate the quantitative hepatic collagen content by two different methods during the different stages of hepatic fibrosis in bile duct-ligated rats on a weekly basis. We questioned whether the 1-wk or 4-wk bile duct-ligated model is suitable in animal fibrogenesis trials. Of the 53 male Wistar rats, 8 (Group 0) were used as a healthy control group. Bile duct ligation (BDL) had been performed in the rest. Bile duct-ligated rates were sacrificed 7 days later in group 1 (10 rats), 14 days later in group 2 (9 rats), 21 days later in group 3(9 rats) and 28 days later in group 4 (9 rats). Eight rats underwent sham-operation (Sham). Hepatic collagen measurements as well as serum levels of liver enzymes and function tests were all analysed. The peak level of collagen was observed biochemically and histomorphometricly at the end of third week (P fibrosis in bile duct-ligated rats is transient, i.e. reverses spontaneously after 3 weeks. This contrasts any situation in patients where hepatic fibrosis is progressive and irreversible as countless studies performed by many investigators in the same animal model.

  1. Long-term assessments after pancreaticoduodenectomy with pancreatic duct invagination anastomosis

    International Nuclear Information System (INIS)

    Fujino, Yasuhiro; Matsumoto, Ippei; Sakai, Tetsuya; Ajiki, Tetsuo; Ueda, Takashi; Kuroda, Yoshikazu; Suzuki, Yasuyuki

    2007-01-01

    The purpose of this cohort was to evaluate the long-term patency of the anastomosis and the remnant pancreatic functions. Fifty-six consecutive patients undergoing a pancreaticoduodenectomy with pancreatic duct invagination anastomosis were enrolled in this study. During the follow-up, changes in the remnant pancreatic duct size, pancreatic exocrine and endocrine functions, and nutritional status were monitored. No seriously activated pancreatic fistula, no hemorrhagic complications, no reoperations, and no in-hospital deaths were observed after surgery. A dilatation of remnant pancreatic duct was detected a total of 37 times (51%) during annual computed tomography (CT) evaluations. Pancreatic dysfunctions were observed in a considerable number of patients (exocrine 4/12, 9/14, and 8/16, endocrine 9/35, 8/27, and 4/16 at 1, 2, and 3 postoperative years, respectively). Functional declines in the remnant pancreas, duct dilatation, and a decrease in the body mass index were observed from the first year. However, these data did not progressively deteriorate thereafter, at least during the first 3 postoperative years. This study demonstrated a significant correlation between the duct dilatation and endocrine dysfunction. Our pancreatic duct invagination anastomosis resulted in somewhat limited long-term outcomes, although it did prevent serious complications in the short-term. (author)

  2. Sound Radiation from a Supersonic Jet Passing Through a Partially Open Exhaust Duct

    Science.gov (United States)

    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.

  3. Role of hydrodynamic instability growth in hot-spot mass gain and fusion performance of inertial confinement fusion implosions

    International Nuclear Information System (INIS)

    Srinivasan, Bhuvana; Tang, Xian-Zhu

    2014-01-01

    In an inertial confinement fusion target, energy loss due to thermal conduction from the hot-spot will inevitably ablate fuel ice into the hot-spot, resulting in a more massive but cooler hot-spot, which negatively impacts fusion yield. Hydrodynamic mix due to Rayleigh-Taylor instability at the gas-ice interface can aggravate the problem via an increased gas-ice interfacial area across which energy transfer from the hot-spot and ice can be enhanced. Here, this mix-enhanced transport effect on hot-spot fusion-performance degradation is quantified using contrasting 1D and 2D hydrodynamic simulations, and its dependence on effective acceleration, Atwood number, and ablation speed is identified

  4. Seismic assessment of the Pickering pressure relief duct

    International Nuclear Information System (INIS)

    Ghobarah, A.

    1995-05-01

    The objectives of the study are to examine the structural response of the Pickering pressure relief duct when subjected to earthquake ground motion and to estimate the seismic withstand capacity of various components of the structural system on the basis of performance criteria consistent with the safety function of the duct. (author). 24 refs., 16 tabs., 31 figs

  5. Optimized Matching Lift Unit Transmission Ratio of Engine Driven Ducted Fan

    Directory of Open Access Journals (Sweden)

    Xiao Senlin

    2018-01-01

    Full Text Available As a kind of VTOL technology, ducted fan is not only used by many kinds of aircrafts, but also one of the trends of the future aircraft lift system, and attracts more and more attention. For an engine driven ducted fan lift unit, involving the engine and ducted fan matching problem, the form of transmission and transmission ratio are the key design parameters. In order to design and develop a ducted fan aircraft reasonably, a thrust test platform was set up to connect the engine with the ducted fan through the belt driving. The matching relationship between the engine and the transmission system was experimentally studied and the optimal transmission ratio was determined. The results showed that the optimal transmission ratio for the engine 1 is 2.2:1, and for the engine 2, the optimal transmission ratio should be 2.95:1 based on the current ducted and movable blade aerofoil design. At this time, the lift will exceed 130 kg•f, meeting the aircraft's original design requirements.

  6. Carcinosarcoma of the Extrahepatic Bile Duct Presenting with Stone-like Radiological Findings.

    Science.gov (United States)

    Kumei, Shinsuke; Onishi, Yutaka; Ogura, Takeshi; Kusumoto, Chosei; Matsuno, Yasuko; Nishigami, Takashi; Maeda, Mitsuo; Harada, Masaru

    2015-01-01

    A 73-year-old woman was referred to our hospital due to epigastralgia and jaundice. The radiological findings showed a stone-like tumor in the extrahepatic bile duct. The patient was initially thought to have adenocarcinoma of the bile duct based on the findings of a pathological examination of the bile duct biopsy specimen and underwent pancreaticoduodenectomy; the final diagnosis of the lesion was so-called carcinosarcoma of the extrahepatic bile duct. She died of liver metastasis six months after the surgery. This case suggests that surgical resection is not adequate for achieving a radical cure, and the optimal treatment for extrahepatic bile duct carcinosarcoma should be established immediately.

  7. Active noise control in a duct to cancel broadband noise

    Science.gov (United States)

    Chen, Kuan-Chun; Chang, Cheng-Yuan; Kuo, Sen M.

    2017-09-01

    The paper presents cancelling duct noises by using the active noise control (ANC) techniques. We use the single channel feed forward algorithm with feedback neutralization to realize ANC. Several kinds of ducts noises including tonal noises, sweep tonal signals, and white noise had investigated. Experimental results show that the proposed ANC system can cancel these noises in a PVC duct very well. The noise reduction of white noise can be up to 20 dB.

  8. Hydrogen disposal investigation for the Space Shuttle launch complex at Vandenberg Air Force Base

    Science.gov (United States)

    Breit, Terry J.; Elliott, George

    1987-01-01

    The concern of an overpressure condition on the aft end of the Space Shuttle caused by ignition of unburned hydrogen being trapped in the Space Shuttle Main Engine exhaust duct at the Vandenberg AFB launch complex has been investigated for fifteen months. Approximately twenty-five concepts have been reviewed, with four concepts being thoroughly investigated. The four concepts investigated were hydrogen burnoff ignitors (ignitors located throughout the exhaust duct to continuously ignite any unburned hydrogen), jet mixing (utilizing large volumes of high pressure air to ensure complete combustion of the hydrogen), steam inert (utilizing flashing hot water to inert the duct with steam) and open duct concept (design an open duct or above grade J-deflector to avoid trapping hydrogen gas). Extensive studies, analyses and testing were performed at six test sites with technical support from twenty-two major organizations. In December 1986, the Air Force selected the steam inert concept to be utilized at the Vandenberg launch complex and authorized the design effort.

  9. Performance of a Hot-Dry Climate Whole-House Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Weitzel, E. [Alliance for Residential Building Innovation, Davis, CA (United States); German, A. [Alliance for Residential Building Innovation, Davis, CA (United States); Porse, E. [Alliance for Residential Building Innovation, Davis, CA (United States)

    2014-06-01

    The Stockton house retrofit is a two-story Tudor style single family deep retrofit in the hot-dry climate of Stockton, CA. The home is representative of a deep retrofit option of the scaled home energy upgrade packages offered to targeted neighborhoods under the pilot Large-Scale Retrofit Program (LSRP) administered by the Alliance for Residential Building Innovation (ARBI). Deep retrofit packages expand on the standard package by adding HVAC, water heater and window upgrades to the ducting, attic and floor insulation, domestic hot water insulation, envelope sealing, lighting and ventilation upgrades. Site energy savings with the deep retrofit were 23% compared to the pre-retrofit case, and 15% higher than the savings estimated for the standard retrofit package. Energy savings were largely a result of the water heater upgrade, and a combination of the envelope sealing, insulation and HVAC upgrade. The HVAC system was of higher efficiency than the building code standard. Overall the financed retrofit would have been more cost effective had a less expensive HVAC system been selected and barriers to wall insulation remedied. The homeowner experienced improved comfort throughout the monitored period and was satisfied with the resulting utility bill savings.

  10. Performance of a Hot-Dry Climate Whole-House Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Weitzel, E.; German, A.; Porse, E.

    2014-06-01

    The Stockton house retrofit is a two-story tudor style single family deep retrofit in the hot-dry climate of Stockton, CA. The home is representative of a deep retrofit option of the scaled home energy upgrade packages offered to targeted neighborhoods under the pilot Large-Scale Retrofit Program (LSRP) administered by the Alliance for Residential Building Innovation (ARBI). Deep retrofit packages expand on the standard package by adding HVAC, water heater and window upgrades to the ducting, attic and floor insulation, domestic hot water insulation, envelope sealing, lighting and ventilation upgrades. Site energy savings with the deep retrofit were 23% compared to the pre-retrofit case, and 15% higher than the savings estimated for the standard retrofit package. Energy savings were largely a result of the water heater upgrade, and a combination of the envelope sealing, insulation and HVAC upgrade. The HVAC system was of higher efficiency than the building code standard. Overall the financed retrofit would have been more cost effective had a less expensive HVAC system been selected and barriers to wall insulation remedied. The homeowner experienced improved comfort throughout the monitored period and was satisfied with the resulting utility bill savings.

  11. Effect of sail on augmenting attitude stability of hovering VTOL vehicle supported by one-ducted-fan. Ductedter dot fan shiji VTOL ki no hover shisei anteisei eno ho no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Ando, S.; Kato, M. (Nagoya University, Nagoya (Japan). Faculty of Engineering)

    1991-07-05

    An analytical investigation was given on augmenting attitude stability of a VTOL airplane supported by one-ducted-fan, at hovering, by means of installing a sail having air resistance on a place higher than the vehicle center-of-gravity. Since the problem becomes nonlinear, the time-marching technique was used. The sail on which the emphasis was placed had an area of as less than several times as much of the duct sectional area, and a height of as less than several times as much of the duct diameter. The stabilization effect is expressed as {Delta}h = center of gravity height region providing the stability/duct diameter. Without a sail, {Delta}h was several percent, but with a sail, the value increased to about ten times as much. This increase in {Delta}h was remarkable in the direction that elevate the position of the center of gravity. More stability is obtained by increasing the sail height than by increasing the area. Substitutes to a sail, working on the same principle, could be a gas-bag and wind mill. A gas-bag, which can change its volume readily, will be able to vary the sail area easily. A wind mill could make the weight lighter than a sail, and has a possibility of varying the resistance through changing its blade pitch angle. 2 refs., 2 figs., 1 tab.

  12. Muellerian duct cyst as a cause of acute infantile-onset epididymitis

    Energy Technology Data Exchange (ETDEWEB)

    Donkol, Ragab H.; Moghazy, Khaled [Gulf Specialist Hospital, Department of Radiology, P.O. Box 1444, Qatif (Saudi Arabia); Monib, Sherif [Gulf Specialist Hospital, Department of General Surgery, Qatif (Saudi Arabia)

    2006-11-15

    Muellerian duct cyst is a congenital anomaly that originates from remnants of the muellerian duct that usually regresses in utero. It is most commonly detected in adult males during the third and fourth decades of life. Muellerian duct cyst is rarely reported in infants less than 1 year of age, in whom diagnosis is difficult because of immaturity of the genital tract. In this case report, we describe the sonographic and CT appearance of a large intrapelvic muellerian duct cyst presenting with acute epididymitis in a 9-month-old infant. The embryological basis, imaging findings and relation to epididymitis are discussed. (orig.)

  13. Muellerian duct cyst as a cause of acute infantile-onset epididymitis

    International Nuclear Information System (INIS)

    Donkol, Ragab H.; Moghazy, Khaled; Monib, Sherif

    2006-01-01

    Muellerian duct cyst is a congenital anomaly that originates from remnants of the muellerian duct that usually regresses in utero. It is most commonly detected in adult males during the third and fourth decades of life. Muellerian duct cyst is rarely reported in infants less than 1 year of age, in whom diagnosis is difficult because of immaturity of the genital tract. In this case report, we describe the sonographic and CT appearance of a large intrapelvic muellerian duct cyst presenting with acute epididymitis in a 9-month-old infant. The embryological basis, imaging findings and relation to epididymitis are discussed. (orig.)

  14. Acoustic power balance in lined ducts

    Science.gov (United States)

    Eversman, W.

    1979-01-01

    It is shown that the two common definitions of acoustic energy density and intensity in uniform unlined ducts carrying uniform flow are compatible to the extent that both energy densities can be used in an appropriate variational principle to derive the convected wave equation. When the duct walls are lined both energy densities must be modified to account for the wall energy density. This results in a new energy conservation equation which utilizes a modified definition of axial power and accounts for wall dissipation. Computations in specific cases demonstrate the validity of the modified acoustic energy relation.

  15. Hemodynamic characterization of chronic bile duct-ligated rats: effect of pentobarbital sodium

    International Nuclear Information System (INIS)

    Lee, S.S.; Girod, C.; Braillon, A.; Hadengue, A.; Lebrec, D.

    1986-01-01

    Systemic and splanchnic hemodynamics of the chronic bile duct-ligated rat were characterized by radioactive microspheres. Conscious and pentobarbital sodium-anesthetized, bile duct-ligated and sham-operated rats had cardiac output and regional organ blood flows determined. The conscious bile duct-ligated rat compared with the sham-operated showed a hyperdynamic circulation with an increased cardiac output and portal tributary blood flow. Pentobarbital sodium anesthesia induced marked hemodynamic changes in both sham-operated and bile duct-ligated rats. The latter group was especially sensitive to its effects; thus, comparison of cardiac output and portal tributary blood flow between anesthetized bile duct-ligated and sham-operated rats showed no significant differences. The authors conclude that the rat with cirrhosis due to chronic bile duct ligation is an excellent model for hemodynamic investigations but should be studied in the conscious state, since pentobarbital sodium anesthesia eliminated the hyperdynamic circulation

  16. Experimental Investigations of the Energy and Environmental Indices of Operation of a Low-Capacity Combined Gas Producer and Hot-Water Boiler

    Science.gov (United States)

    Bodnar, L. A.; Stepanov, D. V.; Dovgal‧, A. N.

    2015-07-01

    It has been shown that the introduction of combined gas producers and boilers on renewable energy sources is a pressing issue. A structural diagram of a low-capacity combined gas producer and boiler on renewable energy sources has been given; a bench and procedures for investigation and processing of results have been developed. Experimental investigations of the energy and environmental indices of a 40-kW combined gas producer and hotwater boiler burning wood have been carried out. Results of the experimental investigations have been analyzed. Distinctive features have been established and a procedure of thermal calculation of the double furnace of a lowcapacity combined gas producer and boiler burning solid fuel has been proposed. The calculated coefficients of heat transfer from the gases in the convection bank have been compared with the obtained experimental results. A calculation dependence for the heat transfer from the gases in convection banks of low-capacity hot-water boilers has been proposed. The quantities of harmful emissions from the combined gas producer and boiler on renewable energy sources have been compared with the existing Ukrainian and foreign standards. It has been established that the environmental efficiency of the boiler under study complies with most of the standard requirements of European countries.

  17. BACTERIOLOGICAL INVESTIGATION ON Fasciola hepatica AND CATTLE BILIARY DUCTS

    Directory of Open Access Journals (Sweden)

    A. Panebianco

    2009-03-01

    Full Text Available The aim of this work was to investigate the occurrence of bacteria in Fasciola hepatica and into cattle biliary ducts containing the parasite. A total of 24 liver and 58 F. hepatica samples were analysed. In all biliary ducts and in 62,06% of parasite Enterobacteriaceae were isolated. The bacterial specie more frequently isolated from parasite were Citrobacter freundii (34%, Proteus mirabilis (18%, Providencia rettgeri (12%, Staphylococcus spp. (18%, Enterobacter spp. (12%. There doesn’t appear to be a correlation between bacterial specie from parasite and ducts. The Authors conclude with some related inspective consideration.

  18. Preoperative intraluminal irradiation of the extrahepatic bile duct tumor

    International Nuclear Information System (INIS)

    Kamada, Tadashi; Tsujii, Hirohiko; Arimoto, Takuro; Irie, Goro.

    1991-01-01

    From 1984 through 1986, six patients with extrahepatic bile duct tumor were treated preoperatively with intraluminal irradiation of the bile duct. There were no unresectable cases and pathological examination of the surgical specimens showed moderate to remarkable tumor regression in all cases. Postoperative biliary tract hemorrhage occurred in 2 of 3 patients who received 60 Gy at a point 7.5 mm from the center of the source. With accurate preoperative diagnosis of the tumor extent and careful setting of the target area of intraluminal irradiation, improved local tumor control of extrahepatic bile duct tumor can be expected with this method. (author)

  19. Tolerance of bile duct to intraoperative irradiation

    International Nuclear Information System (INIS)

    Sindelar, W.F.; Tepper, J.; Travis, E.L.

    1982-01-01

    In order to determine the effects of intraoperative radiation therapy of the bile duct and surrounding tissues, seven adult dogs were subjected to laparotomy and intraoperative irradiation with 11 MeV electrons. Two animals were treated at each dose level of 2000, 3000, and 4500 rads. A single dog which received a laparotomy and sham irradiation served as a control. The irradiation field consisted of a 5 cm diameter circle encompassing the extrahepatic bile duct, portal vein, hepatic artery, and lateral duodenal wall. The animals were followed clinically for mor than 18 months after treatment, and autopsies were performed on dogs that died to assess radiation-induced complications or tissue damage. All dogs developed fibrosis and mural thickening of the common duct, which appeared by 6 weeks following irradiation and which was dose-related, being mild at low doses and more severe at high doses. Hepatic changes were seen as early as 6 weeks after irradiation, consisting of periportal inflammation and fibrosis. The hepatic changes appeared earliest at the highest doses. Frank biliary cirrhosis eventually developed at all dose levels. Duodenal fibrosis appeared in the irradiation portal, being most severe at the highest doses and in some animals resulting in duodenal obstruction. No changes were observed in irradiated portions of portal vein and hepatic artery at any dose level. It was concluded that intraoperative radiation therapy delivered to the region of the common duct leads to ductal fibrosis, partial biliary obstruction with secondary hepatic changes, and duodenal fibrosis if bowel wall is included in the field. Clinical use of intraoperative radiation therapy to the bile duct in humans may require routine use of biliary and duodenal bypass to prevent obstructive complications

  20. Warm-hot baryons comprise 5-10 per cent of filaments in the cosmic web.

    Science.gov (United States)

    Eckert, Dominique; Jauzac, Mathilde; Shan, HuanYuan; Kneib, Jean-Paul; Erben, Thomas; Israel, Holger; Jullo, Eric; Klein, Matthias; Massey, Richard; Richard, Johan; Tchernin, Céline

    2015-12-03

    Observations of the cosmic microwave background indicate that baryons account for 5 per cent of the Universe's total energy content. In the local Universe, the census of all observed baryons falls short of this estimate by a factor of two. Cosmological simulations indicate that the missing baryons have not condensed into virialized haloes, but reside throughout the filaments of the cosmic web (where matter density is larger than average) as a low-density plasma at temperatures of 10(5)-10(7) kelvin, known as the warm-hot intergalactic medium. There have been previous claims of the detection of warm-hot baryons along the line of sight to distant blazars and of hot gas between interacting clusters. These observations were, however, unable to trace the large-scale filamentary structure, or to estimate the total amount of warm-hot baryons in a representative volume of the Universe. Here we report X-ray observations of filamentary structures of gas at 10(7) kelvin associated with the galaxy cluster Abell 2744. Previous observations of this cluster were unable to resolve and remove coincidental X-ray point sources. After subtracting these, we find hot gas structures that are coherent over scales of 8 megaparsecs. The filaments coincide with over-densities of galaxies and dark matter, with 5-10 per cent of their mass in baryonic gas. This gas has been heated up by the cluster's gravitational pull and is now feeding its core. Our findings strengthen evidence for a picture of the Universe in which a large fraction of the missing baryons reside in the filaments of the cosmic web.