Scale Thickness Measurement of Steam Generator Tubing Using Eddy Current Signal of Bobbin Coil

International Nuclear Information System (INIS)

Kim, Chang Soo; Um, Ki Soo; Kim, Jae Dong

2012-01-01

Steam generator is one of the major components of nuclear power plant and steam generator tubes are the pressure boundary between primary and secondary side, which makes them critical for nuclear safety. As the operating time of nuclear power plant increases, not only damage mechanisms but also scaled deposits on steam generator tubes are known to be problematic causing tube support flow hole blockage and heat fouling. The ability to assess the extent and location of scaled deposits on tubes became essential for management and maintenance of steam generator and eddy current bobbin data can be utilized to measure thickness of scale on tubes. In this paper, tube reference standards with various thickness of scaled deposit has been set up to provide information about the overall deposit condition of steam generator tubes, providing essential tool for steam generator management and maintenance to predict and prevent future damages. Also, methodology to automatically measure scale thickness on tubes has been developed and applied to field data to estimate overall scale amount.

Building lab-scale x-ray tube based irradiators

International Nuclear Information System (INIS)

Haff, Ron; Jackson, Eric; Gomez, Joseph; Light, Doug; Follett, Peter; Simmons, Greg; Higbee, Brad

2016-01-01

Here we report the use of x-ray tube based irradiators as alternatives to gamma sources for laboratory scale irradiation. Irradiators were designed with sample placement in closest possible proximity to the source, allowing high dose rates for small samples. Designs using 1000 W x-ray tubes in single tube, double tube, and four tube configurations are described, as well as various cabinet construction techniques. Relatively high dose rates were achieved for small samples, demonstrating feasibility for laboratory based irradiators for research purposes. Dose rates of 9.76, 5.45, and 1.7 Gy/min/tube were measured at the center of a 12.7 cm container of instant rice at 100 keV, 70 keV, and 40 keV, respectively. Dose uniformity varies dramatically as the distance from source to container. For 2.54 cm diameter sample containers containing adult Navel Orangeworm, dose rates of 50–60 Gy/min were measured in the four tube system. - Highlights: • X-ray is demonstrated as an alternative to gamma for lab-based irradiation. • Cabinets using one, two, and four 1000 W tubes are reported. • Dose rate of 9.8 Gy/min/tube at the center of a 12.7 cm container of instant rice. • Dose uniformity varies dramatically as the distance from source to container.

Construction and test of a full-scale prototype of an ATLAS muon spectrometer tracking chamber

International Nuclear Information System (INIS)

Biscossa, A.; Cambiaghi, M.; Conta, C.; Ferrari, R.; Fraternali, M.; Freddi, A.; Iuvino, G.; Lanza, A.; Livan, M.; Negri, A.; Polesello, G.; Rimoldi, A.; Vercellati, F.; Vercesi, V.; Bagnaia, P.; Bini, C.; Capradossi, G.; Ciapetti, G.; Creti, P.; De Zorzi, G.; Iannone, M.; Lacava, F.; Mattei, A.; Nisati, L.; Oberson, P.; Pontecorvo, L.; Rosati, S.; Veneziano, S.; Zullo, A.; Daly, C.H.; Davisson, R.; Guldenmann, H.; Lubatti, H.J.; Zhao, T.

1999-01-01

We have built a full scale prototype of the precision tracking chambers (Monitored Drift Tubes, MDT) for the muon spectrometer of the Atlas Experiment at the LHC collider. This article describes in detail the procedures used in constructing the drift tubes and in assembling the chamber. It presents data showing that the required mechanical precision has been achieved as well as test beam results displaying the over all chamber performance. The article presents data demonstrating the derivation of the space-time relation of the drift tubes by the autocalibration procedure using real data from the tracks crossing the chamber. Autocalibration is the procedure which must be used during run time

LS-DYNA Analysis of a Full-Scale Helicopter Crash Test

Science.gov (United States)

Annett, Martin S.

2010-01-01

A full-scale crash test of an MD-500 helicopter was conducted in December 2009 at NASA Langley's Landing and Impact Research facility (LandIR). The MD-500 helicopter was fitted with a composite honeycomb Deployable Energy Absorber (DEA) and tested under vertical and horizontal impact velocities of 26 ft/sec and 40 ft/sec, respectively. The objectives of the test were to evaluate the performance of the DEA concept under realistic crash conditions and to generate test data for validation of a system integrated LS-DYNA finite element model. In preparation for the full-scale crash test, a series of sub-scale and MD-500 mass simulator tests was conducted to evaluate the impact performances of various components, including a new crush tube and the DEA blocks. Parameters defined within the system integrated finite element model were determined from these tests. The objective of this paper is to summarize the finite element models developed and analyses performed, beginning with pre-test and continuing through post test validation.

Experimental results of the consequences of sodium water reactions at the bottom tube plate region of straight tube steam generators

International Nuclear Information System (INIS)

Ruloff, G.

1990-01-01

Experience with sodium water reactions has shown, that the course of such a steam generator accident depends strongly on its place in the steam generator. For the EFR steam generators we have to differentiate between: weld region at the upper tube plate (gas space); bundle region; weld region at the bottom tube plate. This paper describes results of a running tests program simulating the bottom tube plate area. One main part of these tests is the investigation of the influence of wastage protection shrouds between the tubes in the weld region to avoid a fast leak propagation and to give time for leak detection and mastering of the accidents. (author). 10 figs, 2 tabs

Performance test results of helium gas circulator of mock-up test facility with full-scale reaction tube for HTTR hydrogen production system. Contract research

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Akira; Kato, Michio; Hayashi, Koji [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment] [and others

2003-03-01

Hydrogen production system by steam reforming of methane will be connected to the High Temperature Engineering Test Reactor (HTTR) of the Japan Atomic Energy Research Institute (JAERI) against development of nuclear heat utilization system. To obtain design and safety database of the HTTR hydrogen production system, mock-up test facility with full-scale reaction was constructed in FY 2001 and hydrogen of 120m{sup 3}N{sub /}h was successfully produced in overall performance test. This report describes performance test results of a helium gas circulator in this facility. The circulator performance curves regarding to pressure-rise, input power and adiabatic thermal efficiency at standard revolution number were made based on the measured flow-rate, temperature and pressure data in overall performance test. The circulator performance prediction code was made based on these performance curves. The code can calculate revolution number, electric power and temperature-rise of the circulator using flow-rate, inlet temperature, inlet pressure and pressure-rise data. The verification of the code was carried out with the test data in FY 2002. Total pressure loss of the helium gas circulation loop was also evaluated. The circulator should be operated in conditions such as pressure from 2.7MPa to 4.0MPa and flow-rate from 250g/s to 400g/s and at maximum pressure-rise of 250 kPa in test operation. It was confirmed in above verification and evaluations that the circulator had performance to satisfy above conditions within operation limitation of the circulator such as maximum input-power of 150 kW and maximum revolution number of 12,000 rpm. (author)

Study of the U3O8-Al thermite reaction and strength of reactor fuel tubes

International Nuclear Information System (INIS)

Peacock, H.B.

1983-08-01

Heating tests using 53 wt % U 3 O 8 -Al pellets show that an exothermic reaction occurs between 875 and 1000 0 C and takes 10 to 20 seconds to reach maximum temperature. The maximum temperature is a function of particle size of the U 3 O 8 with large particles exhibiting lower peak temperatures. The calculated energy release was 123 cal/g of U 3 O 8 -aluminum fuel. Tests using aluminum clad outer fuel tube sections gave lower peak temperatures than for pellets. No violent reactions occurred. The results are reasonably consistent with recent reported data indicating that the exothermic U 3 O 8 -Al reaction is not an important energy source. The compressive and tensile strengths of U 3 O 8 tubes above 660 0 C are low. In compression, sections with 2 psi average axial stress failed at 917 0 C, while sections with 7 psi failed at 669 0 C. Tubes with U-Al alloy cores failed at about 670 0 C with no applied load. The stresses in fuel tubes during a reactor transient may range up to several hundred psi and are less than 7 psi only in the upper part of the fuel tube

A study on integrity of LMFBR secondary cooling system to hypothetical tube failure propagation in the steam generator

International Nuclear Information System (INIS)

Yoshihisa Shindo; Kazuo Haga

2005-01-01

Full text of publication follows: A fundamental safety issue of liquid-metal-cooled fast breeder reactor (LMFBR) is to maintain the integrity of the secondary cooling system components against violent chemical sodium-water reaction caused by the water leak from the heat transfer tube of steam generators (SG). The produced sodium-water reaction jet would attack more severely surrounding tubes and would cause other tube failures (tube failure propagation), if it was assumed that the water leak was not detected by function-less detectors and proper operating actions to mitigate the tube failure propagation, such as isolations of the SG from the secondary cooling system and turbine water/steam system, and blowing water and steam inside tubes in the SG, were not taken. This study has been made focusing on the affection of large-scale water leak enlarged due to SG tube failure propagation to the structural integrity of the secondary cooling system because the generated pressure pulse caused by a large-scale sodium-water reaction might break heat transfer tubes of the intermediate heat exchanger (IHX). The present work has been made as one part of the study of probabilistic safety assessment (PSA) of LMFBR, because if the heat-transfer tubes of IHX were failed, the reactor core may be affected by the pressure pulse and/or by the sodium-water reaction products transported through the primary cooling system. As tools for PSA of the water leak incident of SG, we have developed QUARK-LP Version 4 code that mainly analyzes the high temperature rupture phenomena and estimates the number of failed tubes during the middle-scale water leak. The pressure pulse behavior generated by sodium-water reaction in the failure SG and the pressure propagation in the secondary cooling system are calculated by using the SWAAM-2 code developed by ANL. Furthermore, the quasi-steady state high pressure and temperature of the secondary cooling system in a long term is estimated by using the SWAAM

Small Scales Structure of MHD Turbulence, Tubes or Ribbons?

Science.gov (United States)

Verdini, A.; Grappin, R.; Alexandrova, O.; Lion, S.

2017-12-01

Observations in the solar wind indicate that turbulent eddies change their anisotropy with scales [1]. At large scales eddies are elongated in direction perpendicular to the mean-field axis. This is the result of solar wind expansion that affects both the anisotropy and single-spacecraft measurments [2,3]. At small scales one recovers the anisotropy expected in strong MHD turbulence and constrained by the so-called critical balance: eddies are elongated along the mean-field axis. However, the actual eddy shape is intermediate between tubes and ribbons, preventing us to discriminate between two concurrent theories that predict 2D axysimmetric anisotropy [4] or full 3D anisotropy [5]. We analyse 10 years of WIND data and apply a numerically-derived criterion to select intervals in which solar wind expansion is expected to be negligible. By computing the anisotropy of structure functions with respect to the local mean field we obtain for the first time scaling relations that are in agreement with full 3D anisotropy, i.e. ribbons-like structures. However, we cannot obtain the expected scaling relations for the alignment angle which, according to the theory, is physically responsible for the departure from axisymmetry. In addition, a further change of anisotropy occurs well above the proton scales. We discuss the implication of our findings and how numerical simulations can help interpreting the observed spectral anisotropy. [1] Chen et al., ApJ, 768:120, 2012 [2] Verdini & Grappin, ApJL, 808:L34, 2015 [3] Vech & Chen, ApJL, 832:L16, 2016 [4] Goldreich & Shridar, ApJ, 438:763, 1995 [5] Boldyrev, ApJL, 626:L37, 2005

Design of a full scale model fuel assembly for full power production reactor flow excursion experiments

International Nuclear Information System (INIS)

Nash, C.A.; Blake, J.E.; Rush, G.C.

1990-01-01

A novel full scale production reactor fuel assembly model was designed and built to study thermal-hydraulic effects of postulated Savannah River Site (SRS) nuclear reactor accidents. The electrically heated model was constructed to simulate the unique annular concentric tube geometry of fuel assemblies in SRS nuclear production reactors. Several major design challenges were overcome in order to produce the prototypic geometry and thermal-hydraulic conditions. The two concentric heater tubes (total power over 6 MW and maximum heat flux of 3.5 MW/m 2 ) (1.1E+6 BTU/(ft 2 hr)) were designed to closely simulate the thermal characteristics of SRS uranium-aluminum nuclear fuel. The paper discusses the design of the model fuel assembly, which met requirements of maintaining prototypic geometric and hydraulic characteristics, and approximate thermal similarity. The model had a cosine axial power profile and the electrical resistance was compatible with the existing power supply. The model fuel assembly was equipped with a set of instruments useful for code analysis, and durable enough to survive a number of LOCA transients. These instruments were sufficiently responsive to record the response of the fuel assembly to the imposed transient

Treating high-mercury-containing lamps using full-scale thermal desorption technology.

Science.gov (United States)

Chang, T C; You, S J; Yu, B S; Chen, C M; Chiu, Y C

2009-03-15

The mercury content in high-mercury-containing lamps are always between 400 mg/kg and 200,000 mg/kg. This concentration is much higher than the 260 mg/kg lower boundary recommended for the thermal desorption process suggested by the US Resource Conservation and Recovery Act. According to a Taiwan EPA survey, about 4,833,000 cold cathode fluorescent lamps (CCFLs), 486,000 ultraviolet lamps and 25,000 super high pressure mercury lamps (SHPs) have been disposed of in the industrial waste treatment system, producing 80, 92 and 9 kg-mercury/year through domestic treatment, offshore treatment and air emissions, respectively. To deal with this problem we set up a full-scale thermal desorption process to treat and recover the mercury from SHPs, fluorescent tube tailpipes, fluorescent tubes containing mercury-fluorescent powder, and CCFLs containing mercury-fluorescent powder and monitor the use of different pre-heating temperatures and desorption times. The experimental results reveal that the average thermal desorption efficiency of SHPs and fluorescent tube tailpipe were both 99.95%, while the average thermal desorption efficiencies of fluorescent tubes containing mercury-fluorescent powder were between 97% and 99%. In addition, a thermal desorption efficiency of only 69.37-93.39% was obtained after treating the CCFLs containing mercury-fluorescent powder. These differences in thermal desorption efficiency might be due to the complexity of the mercury compounds contained in the lamps. In general, the thermal desorption efficiency of lamps containing mercury-complex compounds increased with higher temperatures.

Dynamic Modelling and Identification of Precipitation Reactions in Full-Scale WWTP

DEFF Research Database (Denmark)

Mbamba, Christian Kazadi; Tait, Stephan; Flores-Alsina, Xavier

, this paper evaluates plant-wide modelling of precipitation reactions using a generic approach integrated within activated sludge and anaerobic models. Preliminary results of anaerobic digester sludge in batch system suggest that the model is able to simulate the dynamics of precipitation reactions. Kinetic...

Stop Smoking—Tube-In-Tube Helical System for Flameless Calcination of Minerals

Directory of Open Access Journals (Sweden)

Nils Haneklaus

2017-11-01

Full Text Available Mineral calcination worldwide accounts for some 5–10% of all anthropogenic carbon dioxide (CO2 emissions per year. Roughly half of the CO2 released results from burning fossil fuels for heat generation, while the other half is a product of the calcination reaction itself. Traditionally, the fuel combustion process and the calcination reaction take place together to enhance heat transfer. Systems have been proposed that separate fuel combustion and calcination to allow for the sequestration of pure CO2 from the calcination reaction for later storage/use and capture of the combustion gases. This work presents a new tube-in-tube helical system for the calcination of minerals that can use different heat transfer fluids (HTFs, employed or foreseen in concentrated solar power (CSP plants. The system is labeled ‘flameless’ since the HTF can be heated by other means than burning fossil fuels. If CSP or high-temperature nuclear reactors are used, direct CO2 emissions can be divided in half. The technical feasibility of the system has been accessed with a brief parametric study here. The results suggest that the introduced system is technically feasible given the parameters (total heat transfer coefficients, mass- and volume flows, outer tube friction factors, and –Nusselt numbers that are examined. Further experimental work will be required to better understand the performance of the tube-in-tube helical system for the flameless calcination of minerals.

Full-scale Mark II CRT program: dynamic response evaluation test of pressure transducers

International Nuclear Information System (INIS)

Kukita, Yutaka; Namatame, Ken; Takeshita, Isao; Shiba, Masayoshi

1982-12-01

A dynamic response evaluation test of pressure transducers was conducted in support of the JAERI Full-Scale Mark II CRT (Containment Response Test) Program. The test results indicated that certain of the cavity-type transducers used in the early blowdown test had undesirable response characteristics. The transducer mounting scheme was modified to avoid trapping of air bubbles in the pressure transmission tubing attached to the transducers. The dynamic response of the modified transducers was acceptable within the frequency range of 200 Hz. (author)

Wastage Behavior of Modified 9Cr-1Mo Steel Tube Material by Sodium-Water Reaction

International Nuclear Information System (INIS)

Jeong, Ji Young; Kim, Jong Man; Kim, Tae Joon; Choi, Jong Hyeun; Kim, Byung Ho; Park, Nam Cook

2009-01-01

The development of a sodium-heated steam generator with safety and reliability is an essential requirement from the viewpoint of the economic efficiency of a sodium-cooled fast reactor. In most cases, these steam generators, which are in the process of development or operating, are of a shell-in tube type, with a high pressure water/steam inside the tubes and low pressure sodium on the shell-side, with a single wall tube as a barrier between these fluids. Therefore, if there is a hole or a crack in a heat transfer tube, a leakage of water/steam into the sodium may occur, resulting in a sodium-water reaction. When such a leak occurs, so-called 'wastage' is the result which may cause damage to or a failure of the adjacent tubes. If a steam generator is operated for some time in this condition, it is possible that it might create an intermediate leak state which would then give rise to the problems of a multi-target wastage in a very short time. Therefore, it is very important to predict these phenomena quantitatively from the view of designing a steam generator and its leak detection systems. The objective of this study is a basic investigating of the sodium-water reaction phenomena by small water/steam leaks. For this, wastage tests for modified 9Cr-1Mo steel were conducted

Numerical study of chemical reactions in a surface microdischarge tube with mist flow based on experiment

International Nuclear Information System (INIS)

Shibata, T; Nishiyama, H

2014-01-01

Recently, a water treatment method of spraying solution into a discharge region has been developed and shows high energy efficiency. In this study, a simulation model of a water treatment method using a surface microdischarge (SMD) tube with mist flow is proposed for further understanding the detailed chemical reactions. Our model has three phases (plasma, gas and liquid) and three simulation steps. The carrier gas is humid air including 2% or 3% water vapour. The chemical species diffusion characteristics in the SMD tube and the concentrations in a droplet are clarified in a wide pH interval. The simulation results show that the chemical species generated on the SMD tube inner wall are diffused to the central axis and dissolved into fine droplets. Especially, OH radicals dissolve into droplets a few mm away from the SMD tube wall because of acidification of the droplets. Furthermore, the hydrogen peroxide density, which is the most important indicator of a radical reaction in water, is influenced by the initial solution pH. This pH dependence results from ozone self-decomposition in water. (paper)

Numerical study of chemical reactions in a surface microdischarge tube with mist flow based on experiment

Science.gov (United States)

Shibata, T.; Nishiyama, H.

2014-03-01

Recently, a water treatment method of spraying solution into a discharge region has been developed and shows high energy efficiency. In this study, a simulation model of a water treatment method using a surface microdischarge (SMD) tube with mist flow is proposed for further understanding the detailed chemical reactions. Our model has three phases (plasma, gas and liquid) and three simulation steps. The carrier gas is humid air including 2% or 3% water vapour. The chemical species diffusion characteristics in the SMD tube and the concentrations in a droplet are clarified in a wide pH interval. The simulation results show that the chemical species generated on the SMD tube inner wall are diffused to the central axis and dissolved into fine droplets. Especially, OH radicals dissolve into droplets a few mm away from the SMD tube wall because of acidification of the droplets. Furthermore, the hydrogen peroxide density, which is the most important indicator of a radical reaction in water, is influenced by the initial solution pH. This pH dependence results from ozone self-decomposition in water.

Wastage Behavior of Modified 9Cr-1Mo Steel Tube Material by Sodium-Water Reaction (II)

International Nuclear Information System (INIS)

Jeong, Ji Young; Kim, Jong Man; Kim, Tae Joon; Choi, Jong Hyeun; Kim, Byung Ho; Lee, Yong Bum; Park, Nam Cook

2010-01-01

The Korea Advanced LIquid MEtal Reactor (KALIMER) steam generator is a helical coil, vertically oriented, shell-and-tube type heat exchanger with fixed tube-sheet. The conceptual design and outline drawing of the steam generator are shown. Flow is counter-current, with sodium on the shell side and water/steam on the tube side. Sodium flow enters the steam generator through the upper inlet nozzles and then flows down through the tube bundle. Feedwater enters the steam generator through the feedwater nozzles at the bottom of steam generator. Therefore, if there is a hole or a crack in a heat transfer tube, a leakage of water/steam into the sodium may occur, resulting in a sodium-water reaction. When such a leak occurs, so-called 'wastage' is the result which may cause damage to or a failure of the adjacent tubes. If a steam generator is operated for some time in this condition, it is possible that it might create an intermediate leak state which would then give rise to the problems of a multi-target wastage in a very short time. Therefore, it is very important to predict these phenomena quantitatively from the view of designing a steam generator and its leak detection systems. The objective of this study is a basic investigating of the sodium-water reaction phenomena by small water/steam leaks. For this, wastage tests for modified 9Cr-1Mo steel tube material were conducted, and an empirical formula of the wastage rate for this material was obtained from the results

Scale model test results for an inverted U-tube steam generator with comparisons to heat transfer correlations

International Nuclear Information System (INIS)

Boucher, T.J.

1987-01-01

To provide data for assessment and development of thermal-hydraulic computer codes, bottom main feedwater-line-break transient simulations were performed in a scale model (Semiscale Mod-2C) of a pressurized water reactor (PWR) with conditions typical of a PWR (15.0 MPa primary pressure, 600 K steam generator inlet plenum fluid temperatures, 6.2 MPa secondary pressure). The state-of-the-art measurements in the scale model (Type III) steam generator allow for the determination of U-tube steam generator allow for the determination of U-tube steam generator secondary component interactions, tube bundle local radial heat transfer, and tube bundle and riser vapor void fractions for steady state and transient operations. To enhance the understanding of the observed phenomena, the component interactions, local heat fluxes, local secondary convective heat transfer coefficients and local vapor void fractions are discussed for steady state, full-power and transient operations. Comparisons between the measurement-derived secondary convective heat transfer coefficients and those predicted by a number of correlations, including the Chen correlation currently used in thermal-hydraulic computer codes, show that none of the correlations adequately predict the data and points out the need for the formulation of a new correlation based on this experimental data. The unique information presented herein should be of the interest to anyone involved in modeling inverted U-tube steam generator thermal-hydraulics for forced convection boiling/vaporization heat transfer. 5 refs., 13 figs., 1 tab

Scale-up of heterogeneous catalytic reactions

Energy Technology Data Exchange (ETDEWEB)

Heggs, P; Sunderland, P

1979-12-01

This report on the Institution of Chemical Engineers ''Problems in Applied Catalysis'' Meeting (Bath, U.K. 1/4-5/78) covers papers on the nature of the catalyst surface, including the use of IR spectroscopy, electron energy loss spectroscopy, low-energy electron diffraction, electron spectroscopy, secondary ion mass spectroscopy, and modular-beam scattering for investigating solid surfaces and their relevance to catalysis; study of the reaction mechanisms by which catalysis takes place; use of mechanistic models to determine the true chemical kinetics illustrated for the oxidation of benzene to maleic anhydride over a vanadium pentoxide/molybdenum trioxide catalyst; the study with respect to the importance of transport effects in catalyst pellets on scale-up, falsification of true kinetics, and the design of laboratory reactors; full-scale reactor design of packed-bed reactors; and practical scale-up problems illustrated for methanol synthesis over a copper catalyst, ammonia oxidation over a cobalt oxide catalyst, and the steam reforming of naphtha.

Drift-tube studies of ion-molecule reactions at low collision energies

International Nuclear Information System (INIS)

Chatterjee, B.K.

1988-01-01

This thesis presents experimental studies of ion-molecule reactions at low collision energies using two drift tube mass spectrometer apparatus. The reactions studied are (i) proton transfer from HeH + to ArH + , (ii) charge and ion transfer reactions of O 2 2+ with NO, CO 2 , Ne and O 2 + ( 4 π u ) with CO 2 , (iii) oxidation reactions of Zr + and ZrO + with NO, CO 2 and O 2 , (iv) vibrational quenching reactions of H 3 + with He, (v) termolecular clustering reactions of H 2 CN + and H 2 CN + (HCN) (with He as the third body), (vi) three body association reactions of H + and D + with He (with He as the third body) and (vii) termolecular association reaction of NO + with NO (with Ne as third body). All the reactions were studied at thermal energies (at room temperature), reactions of O 2 2+ with NO and CO 2 , Zr + with NO/CO 2 /O 2 were also studied at center-of-mass energies higher than thermal and the association reactions of H 2 CN + /H 2 CN + (HCN) with HCN and H + /D + with He were studied at low temperatures. In addition, the thesis presents model calculations for the sweep-out effect which is an instrumental effect. A super Langevin rate constant is introduced which is a higher-order correction to the Langevin model. A theoretical model for the three-body ion-atom association rate constant is presented in the appendix of the thesis

Porous double-layer polymer tubing for the potential use in heterogeneous continuous flow reactions.

Science.gov (United States)

Herwig, Gordon; Hornung, Christian H; Peeters, Gary; Ebdon, Nicholas; Savage, G Paul

2014-12-24

Functional polymer tubing with an OD of 1/16 or 1/8 in. was fabricated by a simple polymer coextrusion process. The tubing was made of an outer impervious polypropylene layer and an inner layer, consisting of a blend of a functional polymer, polyethylene-co-methacrylic acid, and a sacrificial polymer, polystyrene. After a simple solvent leaching step using common organic solvents, the polystyrene was removed, leaving behind a porous inner layer that contains functional carboxylic acid groups, which could then be used for the immobilization of target molecules. Solution-phase reactions using amines or isocyanates have proven successful for the immobilization of a series of small molecules and polymers. This flexible multilayered functional tubing can be easily cut to the desired length and connected via standard microfluidic fittings.

Wastage-resistant characteristics of 12Cr steel tube material. Small leak sodium-water reaction test

International Nuclear Information System (INIS)

Shimoyama, Kazuhito

2004-03-01

In the water leak accident of a steam generator designed for a sodium cooled reactor in the Feasibility Study, the localization of tube failure propagation by using an advanced water leak detector will be required from the viewpoints of the safety and economical efficiency of the plant. So far, the conventional knowledge and analytical tools have been used in the investigation and evaluation of water leak phenomenon; nevertheless, there was neither test data nor the study of quantitative evaluation on the corrosion behavior, so-called wastage-resistant characteristics, of 12Cr steel tube material in sodium-water reactions. Wastage tests for the 12Cr steel tube material were conducted in small water leaks by use of the Sodium-Water Reaction Test Rig (SWAT-1R), and the data of wastage rate were obtained in the parameter of water leak rate under the constant sodium temperature and distance between leak and target tubes. The test results lead to the following conclusions: (1) The wastage-resistibility of 12Cr steel is 1.6 times greater than that of 9Cr steel and is 2.7 times greater than that of 2.25Cr-1Mo steel. (2)The wastage-resistibility of 12Cr steel increases in smaller water leaks; especially in water leak rates of 1 g/sec or less, it is more excellent than that of SUS321 stainless steel used as Monju superheater tube material. (3) Based on the correlation of wastage rate for the 9Cr steel, the correlation for the 12Cr steel has been obtained to be used for the evaluation of tube failure propagation. As the correlation of wastage rate for the 12Cr steel is based on the correlation for the 9Cr steel, it gives enough conservatism in smaller water leaks. To serve in accurately evaluating the tube failure propagation in smaller water leaks, it is necessary to obtain new correlation of wastage rate for the 12Cr steel based on the data in the wide range of water leak rates. (author)

78 FR 74161 - Light-Walled Rectangular Pipe and Tube From China, Korea, Mexico, and Turkey; Scheduling of Full...

Science.gov (United States)

2013-12-10

...-Walled Rectangular Pipe and Tube From China, Korea, Mexico, and Turkey; Scheduling of Full Five-Year... the Antidumping Duty Orders on Light-Walled Rectangular Pipe and Tube From China, Korea, Mexico, and... on light- walled rectangular pipe and tube from China, Korea, Mexico, and Turkey would be likely to...

Design of a high-pressure single pulse shock tube for chemical kinetic investigations

International Nuclear Information System (INIS)

Tranter, R. S.; Brezinsky, K.; Fulle, D.

2001-01-01

A single pulse shock tube has been designed and constructed in order to achieve extremely high pressures and temperatures to facilitate gas-phase chemical kinetic experiments. Postshock pressures of greater than 1000 atmospheres have been obtained. Temperatures greater than 1400 K have been achieved and, in principle, temperatures greater than 2000 K are easily attainable. These high temperatures and pressures permit the investigation of hydrocarbon species pyrolysis and oxidation reactions. Since these reactions occur on the time scale of 0.5--2 ms the shock tube has been constructed with an adjustable length driven section that permits variation of reaction viewing times. For any given reaction viewing time, samples can be withdrawn through a specially constructed automated sampling apparatus for subsequent species analysis with gas chromatography and mass spectrometry. The details of the design and construction that have permitted the successful generation of very high-pressure shocks in this unique apparatus are described. Additional information is provided concerning the diaphragms used in the high-pressure shock tube

Polymerase-endonuclease amplification reaction (PEAR for large-scale enzymatic production of antisense oligonucleotides.

Directory of Open Access Journals (Sweden)

Xiaolong Wang

Full Text Available Antisense oligonucleotides targeting microRNAs or their mRNA targets prove to be powerful tools for molecular biology research and may eventually emerge as new therapeutic agents. Synthetic oligonucleotides are often contaminated with highly homologous failure sequences. Synthesis of a certain oligonucleotide is difficult to scale up because it requires expensive equipment, hazardous chemicals and a tedious purification process. Here we report a novel thermocyclic reaction, polymerase-endonuclease amplification reaction (PEAR, for the amplification of oligonucleotides. A target oligonucleotide and a tandem repeated antisense probe are subjected to repeated cycles of denaturing, annealing, elongation and cleaving, in which thermostable DNA polymerase elongation and strand slipping generate duplex tandem repeats, and thermostable endonuclease (PspGI cleavage releases monomeric duplex oligonucleotides. Each round of PEAR achieves over 100-fold amplification. The product can be used in one more round of PEAR directly, and the process can be further repeated. In addition to avoiding dangerous materials and improved product purity, this reaction is easy to scale up and amenable to full automation. PEAR has the potential to be a useful tool for large-scale production of antisense oligonucleotide drugs.

A tentative programme towards a full scale energy amplifier

CERN Document Server

Rubbia, Carlo

1996-01-01

We present a proposal of a full scale demonstration plant of the Energy Amplifier (EA), following the conceptual design of Ref. [1]. Unlike the presently on going CERN experiments, reaction rates will be sufficiently massive to permit demonstrating the practical feasibility of energy generation on an industrial scale and to tackle the complete family chains of [1] the breeding process in Thorium fuel, [2] the burning of the self-generated Actinides, [3] the Plutonium (higher Actinides) burning of spent fuel from ordinary Reactors and [4] Fuel reprocessing/regeneration. The accelerator must provide a beam power which is commensurate to the rate of transformations which are sought. No existing accelerator can meet such a performance and a dedicated facility must be built. We describe an alternative based on the superconducting cavities (SC) now in standard use at the LEP \\[e^+-e^-\\] collider which is scheduled to terminate its operation by year 200 After this time, with reasonable modifications, the fully opera...

An investigation of the effect of pore scale flow on average geochemical reaction rates using direct numerical simulation

Energy Technology Data Exchange (ETDEWEB)

Molins, Sergi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division; Trebotich, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Computational Research Division; Steefel, Carl I. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division; Shen, Chaopeng [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Computational Research Division

2012-03-30

The scale-dependence of geochemical reaction rates hinders their use in continuum scale models intended for the interpretation and prediction of chemical fate and transport in subsurface environments such as those considered for geologic sequestration of CO₂. Processes that take place at the pore scale, especially those involving mass transport limitations to reactive surfaces, may contribute to the discrepancy commonly observed between laboratory-determined and continuum-scale or field rates. In this study we investigate the dependence of mineral dissolution rates on the pore structure of the porous media by means of pore scale modeling of flow and multicomponent reactive transport. The pore scale model is composed of high-performance simulation tools and algorithms for incompressible flow and conservative transport combined with a general-purpose multicomponent geochemical reaction code. The model performs direct numerical simulation of reactive transport based on an operator-splitting approach to coupling transport and reactions. The approach is validated with a Poiseuille flow single-pore experiment and verified with an equivalent 1-D continuum-scale model of a capillary tube packed with calcite spheres. Using the case of calcite dissolution as an example, the high-resolution model is used to demonstrate that nonuniformity in the flow field at the pore scale has the effect of decreasing the overall reactivity of the system, even when systems with identical reactive surface area are considered. In conclusion, the effect becomes more pronounced as the heterogeneity of the reactive grain packing increases, particularly where the flow slows sufficiently such that the solution approaches equilibrium locally and the average rate becomes transport-limited.

Results and analysis of high heat flux tests on a full-scale vertical target prototype of ITER divertor

International Nuclear Information System (INIS)

Missirlian, M.; Escourbiac, F.; Merola, M.; Bobin-Vastra, I.; Schlosser, J.; Durocher, A.

2005-01-01

After an extensive R and D development program, a full-scale divertor target prototype, manufactured with all the main features of the corresponding ITER divertor, was intensively tested in the high heat flux FE200 facility. The prototype consists of four units having a full monoblock geometry. The lower part (CFC armour) and the upper part (W armour) of each monoblock were joined to the solution annealed, quenched and cold worked CuCrZr tube by HIP technique. This paper summarises and analyses the main test results obtained on this prototype

Field theory modelling of vortex tube entanglement in turbulent magnetohydrodynamics

International Nuclear Information System (INIS)

Moriconi, L.; Nobre, F.A. S.

2000-01-01

Full text follows: We study the dynamics of interacting closed vortex tubes in magnetohydrodynamics, in terms of a (1+1)-dimensional field theory derived within the context of the Martin-Siggia-Rose formalism. The fluid is stirred by large scale stochastic forces which affect smaller scales through foldings of the velocity and magnetic vortex tubes. Numerical computations are done by means of a length-preserving scheme, motivated by the usual self-induction approximation. In order to understand the origin of intermittency effects, we investigate the multifractal exponents for the equilibrium vortex tube configurations, as well as correlations developed between different tubes. (author)

Why Online Education Will Attain Full Scale

Science.gov (United States)

Sener, John

2010-01-01

Online higher education has attained scale and is poised to take the next step in its growth. Although significant obstacles to a full scale adoption of online education remain, we will see full scale adoption of online higher education within the next five to ten years. Practically all higher education students will experience online education in…

One-Tube-Only Standardized Site-Directed Mutagenesis: An Alternative Approach to Generate Amino Acid Substitution Collections.

Directory of Open Access Journals (Sweden)

Janire Mingo

Full Text Available Site-directed mutagenesis (SDM is a powerful tool to create defined collections of protein variants for experimental and clinical purposes, but effectiveness is compromised when a large number of mutations is required. We present here a one-tube-only standardized SDM approach that generates comprehensive collections of amino acid substitution variants, including scanning- and single site-multiple mutations. The approach combines unified mutagenic primer design with the mixing of multiple distinct primer pairs and/or plasmid templates to increase the yield of a single inverse-PCR mutagenesis reaction. Also, a user-friendly program for automatic design of standardized primers for Ala-scanning mutagenesis is made available. Experimental results were compared with a modeling approach together with stochastic simulation data. For single site-multiple mutagenesis purposes and for simultaneous mutagenesis in different plasmid backgrounds, combination of primer sets and/or plasmid templates in a single reaction tube yielded the distinct mutations in a stochastic fashion. For scanning mutagenesis, we found that a combination of overlapping primer sets in a single PCR reaction allowed the yield of different individual mutations, although this yield did not necessarily follow a stochastic trend. Double mutants were generated when the overlap of primer pairs was below 60%. Our results illustrate that one-tube-only SDM effectively reduces the number of reactions required in large-scale mutagenesis strategies, facilitating the generation of comprehensive collections of protein variants suitable for functional analysis.

Design and Simulation of a New Optimized Full-Adder Using Carbon Nano Tube Technology

Directory of Open Access Journals (Sweden)

Abbas Asadi Aghbolaghi

2015-07-01

Full Text Available The full adder circuit is one of the most significant and prominent fundamental parts in digital processors and integrated circuits since it can be used for implementing all four basic computational functions including: addition, subtraction, multiplication, and division. so, in this paper a new low power and high performance full adder cell has been proposed with the benefit of using carbon nano tube field effect transistors. The proposed design contains 12 CNTFET transistors which are connected in pass transistor logic style to make the desired functionality. Carbon Nano Tube Field Effect Transistor (CNTFET has modified electrical characteristics such as low power consumption and high speed in comparison with MOSFET transistor; The proposed design is simulated using Hspice software based on CNTFET model and 0.65V supply voltage. the simulations are done considering three different frequencies, and three different load capacitors. The simulation results, which demonstrated in tables and diagrams, proved the superiority of proposed design in terms of power consumption and performance (PDP compared to the existing counterparts.

Utilization of Stop-flow Micro-tubing Reactors for the Development of Organic Transformations.

Science.gov (United States)

Toh, Ren Wei; Li, Jie Sheng; Wu, Jie

2018-01-04

A new reaction screening technology for organic synthesis was recently demonstrated by combining elements from both continuous micro-flow and conventional batch reactors, coined stop-flow micro-tubing (SFMT) reactors. In SFMT, chemical reactions that require high pressure can be screened in parallel through a safer and convenient way. Cross-contamination, which is a common problem in reaction screening for continuous flow reactors, is avoided in SFMT. Moreover, the commercially available light-permeable micro-tubing can be incorporated into SFMT, serving as an excellent choice for light-mediated reactions due to a more effective uniform light exposure, compared to batch reactors. Overall, the SFMT reactor system is similar to continuous flow reactors and more superior than batch reactors for reactions that incorporate gas reagents and/or require light-illumination, which enables a simple but highly efficient reaction screening system. Furthermore, any successfully developed reaction in the SFMT reactor system can be conveniently translated to continuous-flow synthesis for large scale production.

Large-Scale Production of Nanographite by Tube-Shear Exfoliation in Water.

Directory of Open Access Journals (Sweden)

Nicklas Blomquist

Full Text Available The number of applications based on graphene, few-layer graphene, and nanographite is rapidly increasing. A large-scale process for production of these materials is critically needed to achieve cost-effective commercial products. Here, we present a novel process to mechanically exfoliate industrial quantities of nanographite from graphite in an aqueous environment with low energy consumption and at controlled shear conditions. This process, based on hydrodynamic tube shearing, produced nanometer-thick and micrometer-wide flakes of nanographite with a production rate exceeding 500 gh-1 with an energy consumption about 10 Whg-1. In addition, to facilitate large-area coating, we show that the nanographite can be mixed with nanofibrillated cellulose in the process to form highly conductive, robust and environmentally friendly composites. This composite has a sheet resistance below 1.75 Ω/sq and an electrical resistivity of 1.39×10-4 Ωm and may find use in several applications, from supercapacitors and batteries to printed electronics and solar cells. A batch of 100 liter was processed in less than 4 hours. The design of the process allow scaling to even larger volumes and the low energy consumption indicates a low-cost process.

A Role for YouTube in Telerehabilitation

Directory of Open Access Journals (Sweden)

M. Hunter Manasco

2010-10-01

Full Text Available YouTube is a free video sharing website that allows users to post and view videos. Although there are definite limitations in the applicability of this website to telerehabilitation, there are possible uses that should not be overlooked. Certain types of therapy, such as errorless learning therapy for certain language and cognitive deficits can be provided remotely via YouTube. In addition, negative emotional reactions to deficits are known to delay or halt recovery. The social networking capability YouTube provides enables individuals with health problems that may be unable to leave their houses an opportunity to gain valuable emotional support by meeting and communicating with others with similar problems. This article address the benefits and limitations of YouTube in the context of telerehabilitation and reports patient feedback on errorless learning therapy for aphasia delivered via videos posted on YouTube. 

Strontium Removal: Full-Scale Ohio Demonstrations

Science.gov (United States)

The objectives of this presentation are to present a brief overview of past bench-scale research to evaluate the impact lime softening on strontium removal from drinking water and present full-scale drinking water treatment studies to impact of lime softening and ion exchange sof...

High-temperature shock tube and modeling studies on the reactions of methanol with D-atoms and CH3-radicals.

Science.gov (United States)

Peukert, S L; Michael, J V

2013-10-10

The shock tube technique has been used to study the hydrogen abstraction reactions D + CH3OH → CH2O + H + HD (A) and CH3 + CH3OH → CH2O + H + CH4 (B). For reaction A, the experiments span a T-range of 1016 K ≤ T ≤ 1325 K, at pressures 0.25 bar ≤ P ≤ 0.46 bar. The experiments on reaction B, CH3 + CH3OH, cover a T-range of 1138 K ≤ T ≤ 1270 K, at pressures around 0.40 bar. Reflected shock tube experiments, monitoring the depletion of D-atoms by applying D-atom atomic resonance absorption spectrometry (ARAS), were performed on reaction A using gas mixtures of C2D5I and CH3OH in Kr bath gas. C2D5I was used as precursor for D-atoms. For reaction B, reflected shock tube experiments monitoring H-atom formation with H-ARAS, were carried out using gas mixtures of diacetyl ((CH3CO)2) and CH3OH in Kr bath gas. (CH3CO)2 was used as the source of CH3-radicals. Detailed reaction models were assembled to fit the D-atom and H-atom time profiles in order to obtain experimental rate constants for reactions A and B. Total rate constants from the present experiments on D + CH3OH and CH3 + CH3OH can be represented by the Arrhenius equations kA(T) = 1.51 × 10(-10) exp(-3843 K/T) cm(3) molecules(-1) s(-1) (1016 K ≤ T ≤ 1325 K) and kB(T) = 9.62 × 10(-12) exp(-7477 K/T) cm(3) molecules(-1) s(-1) (1138 K ≤ T ≤ 1270 K). The experimentally obtained rate constants were compared with available rate data from the literature. The results from quantum chemical studies on reaction A were found to be in good agreement with the present results. The present work represents the first direct experimental study on these bimolecular reactions at combustion temperatures and is important to the high-temperature oxidation of CH3OH.

Full-scale and time-scale heating experiments at Stripa: preliminary results

International Nuclear Information System (INIS)

Cook, N.G.W.; Hood, Michael; California Univ., Berkeley

1978-01-01

Two full-scale heating experiments and a time-scale heating experiment have recently been started in granite 340 meters below surface. The purpose of the full-scale heating experiments is to assess the near-field effects of thermal loading for the design of an underground repository of nuclear wastes. That of the time-scale heating experiments is to obtain field data of the interaction between heaters and its effect on the rock mass during a period of about two years, which corresponds to about twenty years of full-scale operation. Geological features of the rock around each experiment have been mapped carefully, and temperatures, stresses and displacements induced in the rock by heating have been calculated in advance of the experiments. Some 800 different measurements are recorded at frequent intervals by a computer system situated underground. These data can be compared at any time with predictions made earlier on video display units underground

CT findings of foreign body reaction to retained endoloop ligature plastic tube mimicking acute appendicitis: A case report

Energy Technology Data Exchange (ETDEWEB)

Ahn, Jae Hong; Kang, Chae Hoon; Choi, Soo Jung; Park, Man Soo; Jung, Seung Mun; Ryu, Dae Shick; Shin, Dong Rock [Dept. of Radiology, GangNeung Asan Hospital, University of Ulsan College of Medicine, Gangneung (Korea, Republic of)

2016-07-15

Many hospitals experience one or more retained surgical instrument events with risk of patient morbidity and medicolegal problems. Identification of retained surgical instrument is important. The radiologists should be familiar with imaging finding of retained surgical instrument. In a 62-year-old female with a retained plastic tube, localized peritoneal infiltration around air-containing tubular structure mimicked acute appendicitis on abdomen computed tomography (CT), one year after laparoscopic cholecystectomy. We reported CT findings of foreign body reaction related to retained Endoloop ligature plastic tube mimicking acute appendicitis.

CT findings of foreign body reaction to retained endoloop ligature plastic tube mimicking acute appendicitis: A case report

International Nuclear Information System (INIS)

Ahn, Jae Hong; Kang, Chae Hoon; Choi, Soo Jung; Park, Man Soo; Jung, Seung Mun; Ryu, Dae Shick; Shin, Dong Rock

2016-01-01

Many hospitals experience one or more retained surgical instrument events with risk of patient morbidity and medicolegal problems. Identification of retained surgical instrument is important. The radiologists should be familiar with imaging finding of retained surgical instrument. In a 62-year-old female with a retained plastic tube, localized peritoneal infiltration around air-containing tubular structure mimicked acute appendicitis on abdomen computed tomography (CT), one year after laparoscopic cholecystectomy. We reported CT findings of foreign body reaction related to retained Endoloop ligature plastic tube mimicking acute appendicitis

Annular gap measurement between pressure tube and calandria tube by eddy current technique

International Nuclear Information System (INIS)

Bhole, V.M.; Rastogi, P.K.; Kulkarni, P.G.

1992-01-01

In pressurised heavy water reactor (PHWR) major distinguishing feature is that there are number of identical fuel channels in the reactor core. Each channel consists of pressure tube of Zr-2.5 Nb or zircaloy-2 through which high temperature, high pressure primary coolant is passing. The pressure tube contains fuel. Surrounding the pressure tube there is low pressure, cool heavy water (moderator). The moderator is thermally separated from coolant by the tube which is nominally concentric with pressure tube called calandria tube. There are four garter springs in the annular gap between pressure tube and calandria tube. During the life of the reactor there are number of factors by which the pressure tube sags, most important factors are irradiation creep, thermal creep, fuel load etc. Because of the sag of pressure tube it can touch the calandria tube resulting in formation of cold spot. This leads to hydrogen concentration at that spot by which the material at that place becomes brittle and can lead to catastrophic failure of pressure tube. There is no useful access for measurement of annular gap either through the gas annular space or from exterior of calandria tube. So the annular gap was measured from inside surface of pressure tube which is accessible. Eddy current technique was used for finding the gap. The paper describe the details of split coil design of bobbin probe, selection of operating point on normalised impedance diagram by choosing frequency. Experimental results on full scale mock up, and actual gap measurement in reactor channel, are also given. (author). 7 figs

Study of the U3O8-Al thermite reaction and strength of reactor fuel tubes

International Nuclear Information System (INIS)

Peacock, H.B.

1984-01-01

Research and test reactors are presently operated with aluminum-clad fuel elements containing highly enriched uranium-aluminum alloy cores. To lower the enrichment and still maintain reactivity, the uranium content of the fuel element will need to be higher than currently achievable with alloy fuels. This will necessitate conversion to other forms such as U 3 O 8 -aluminum cermets. Above the aluminum melting point, U 3 O 8 and aluminum undergo an exothermic thermite reaction and cermet fuel cores tend to keep their original shape. Both factors could affect the course and consequences of a reactor accident, and therefore prompted an investigation of the behavior of cermet fuels at elevated temperatures. Tests were carried out using pellets and extruded tube sections with 53 wt % U 3 O 8 in aluminum. This content corresponds to a theoretical uranium density of 1.9 g/cc. Results indicate that the thermite reaction occurs at about 900 0 C in air without a violent effect. The heat of reaction was approximately 123 cal/g of U 3 O 8 -aluminum fuel. Tensile and compressive strength of the fuel tube section is low above 660 0 C. In tension, sections failed at about the aluminum melting point. In compression with 2 psi average axial stress, failure occurred at 917 0 C, while 7 psi average axial stress produced failure at 669 0 C. (author)

Study of the U3O8-Al thermite reaction and strength of reactor fuel tubes

International Nuclear Information System (INIS)

Peacock, H.B.

1983-01-01

Research and test reactors are presently operated with aluminum-clad fuel elements containing highly enriched uranium-aluminum alloy cores. To lower the enrichment and still maintain reactivity, the uranium content of the fuel element will need to be higher than currently achievable with alloy fuels. This will necessitate conversion to other forms such as U 3 O 8 -aluminum cermets. Above the aluminum melting point, U 3 O 8 and aluminum undergo an exothermic thermite reaction and cermet fuel cores tend to keep their original shape. Both factors could affect the course and consequences of a reactor accident, and prompted an investigation of the behavior of cermet fuels at elevated temperatures. Tests were carried out using pellets and extruded tube-sections with 53 wt % U 3 O 8 in aluminum. This content corresponds to a theoretical uranium density of 1.9 g/cc. Results indicate that the thermite reaction occurs at about 900 0 C in air without a violent effect. The heat of reaction was approximately 123 cal/g of U 3 O 8 -aluminum fuel. Tensile and compressive strength of the fuel tube section is low above 660 0 C. In tension, sections failed at about the aluminum melting point. In compression with 2-psi average axial stress, failure occurred at 917 0 C, while 7 psi average axial stress produced failure at 669 0 C

Estimation of residual life of boiler tubes using steamside oxide scale thickness

International Nuclear Information System (INIS)

Vikrant, K.S.N.; Ramareddy, G.V.; Pavan, A.H.V.; Singh, Kulvir

2013-01-01

In thermal power plants, remaining-life-estimation of boiler tubes is required at regular intervals for a safer and a better functionality of boilers. In this paper, a new method is proposed for the residual life estimation of service exposed boiler tubes using Non-Destructive Ultrasonic Oxide scale thickness measurements, average metal temperature and creep master curve. While steady state conduction heat transfer equations are solved to calculate the average metal temperature, creep master curve is generated from short term stress rupture data of rupture life less than 5000 h on a virgin material. In the present study, the residual life of T22 (2.25Cr-1Mo) service exposed Platen Superheater tube is estimated using two master creep curves, i.e. Larson-Miller Parametric (LMP) method of standard ASME T22 creep data and Wilshire approach of short term stress rupture data of T22. As the residual life is calculated from fundamental conduction heat transfer theory and creep rupture data, the proposed method can be applied for different grades of boiler materials. -- Highlights: ► Residual life is calculated from non-destructive oxide scale thickness, creep master curve and average metal temperature. ► A new method is proposed for calculating residual life using above parameters and from conduction heat transfer principles. ► The method can be applied to different boiler grades for estimating residual life and hence the method is generic

Flow chemistry: intelligent processing of gas-liquid transformations using a tube-in-tube reactor.

Science.gov (United States)

Brzozowski, Martin; O'Brien, Matthew; Ley, Steven V; Polyzos, Anastasios

2015-02-17

reactive gas in a given reaction mixture. We have developed a tube-in-tube reactor device consisting of a pair of concentric capillaries in which pressurized gas permeates through an inner Teflon AF-2400 tube and reacts with dissolved substrate within a liquid phase that flows within a second gas impermeable tube. This Account examines our efforts toward the development of a simple, unified methodology for the processing of gaseous reagents in flow by way of development of a tube-in-tube reactor device and applications to key C-C, C-N, and C-O bond forming and hydrogenation reactions. We further describe the application to multistep reactions using solid-supported reagents and extend the technology to processes utilizing multiple gas reagents. A key feature of our work is the development of computer-aided imaging techniques to allow automated in-line monitoring of gas concentration and stoichiometry in real time. We anticipate that this Account will illustrate the convenience and benefits of membrane tube-in-tube reactor technology to improve and concomitantly broaden the scope of gas/liquid/solid reactions in organic synthesis.

Full-color laser cathode ray tube (L-CRT) projector

Science.gov (United States)

Kozlovskiy, Vladimir; Nasibov, Alexander S.; Popov, Yuri M.; Reznikov, Parvel V.; Skasyrsky, Yan K.

1995-04-01

A full color TV projector based on three laser cathode-ray tubes (L-CRT) is described. A water-cooled laser screen (LS) is the radiation element of the L-CRT. We have produced three main colors (blue, green and red) by using the LS made of three II-VI compounds: ZnSe ((lambda) equals 475 nm), CdS ((lambda) equals 530 nm) and ZnCdSe (630 nm). The total light flow reaches 1500 Lm, and the number of elements per line is not less than 1000. The LS efficiency may be about 10 Lm/W. In our experiments we have tested new electron optics: - (30 - 37) kV are applied to the cathode unit of the electron gun; the anode of the e-gun and the e-beam intensity modulator are under low potential; the LS has a potential + (30 - 37) kV. The accelerating voltage is divided into two parts, and this enables us to diminish the size and weight of the projector.

Chromosomal Abnormalities Associated with Neural Tube Defects (I: Full Aneuploidy

Directory of Open Access Journals (Sweden)

Chih-Ping Chen

2007-12-01

Full Text Available Fetuses with neural tube defects (NTDs carry a risk of chromosomal abnormalities. The risk varies with maternal age, gestational age at diagnosis, association with other structural abnormalities, and family history of chromosome aberrations. This article provides an overview of chromosomal abnormalities associated with NTDs in embryos, fetuses, and newborn patients, and a comprehensive review of numerical chromosomal abnormalities associated with NTDs, such as trisomy 18, trisomy 13, triploidy, trisomy 9, trisomy 2, trisomy 21, trisomy 7, trisomy 8, trisomy 14, trisomy 15, trisomy 16, trisomy 5 mosaicism, trisomy 11 mosaicism, trisomy 20 mosaicism, monosomy X, and tetraploidy. NTDs may be associated with aneuploidy. Perinatal identification of NTDs should alert one to the possibility of chromosomal abnormalities and prompt a thorough cytogenetic investigation and genetic counseling.

CT Findings of Foreign Body Reaction to a Retained Endoloop Ligature Plastic Tube Mimicking Acute Appendicitis: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Ahn, Jae Hong; Kang, Chae Hoon; Choi, Soo-Jung; Park, Man Soo; Jung, Seung Mun; Ryu, Dae Shick; Shin, Dong Rock [Department of Radiology, Asan Foundation, GangNeung Asan Hospital, University of Ulsan College of Medicine, Gangneung 25440 (Korea, Republic of)

2016-11-01

Many hospitals experience one or more retained surgical instrument events with risk of patient morbidity and medicolegal problems. Identification of retained surgical instrument is important. The radiologists should be familiar with imaging finding of retained surgical instrument. In a 62-year-old female with a retained plastic tube, localized peritoneal infiltration around air-containing tubular structure mimicked acute appendicitis on abdomen computed tomography (CT), one year after laparoscopic cholecystectomy. We reported CT findings of foreign body reaction related to retained Endoloop ligature plastic tube mimicking acute appendicitis.

Acoustic emission analysis on tensile failure of steam-side oxide scales formed on T22 alloy superheater tubes

Energy Technology Data Exchange (ETDEWEB)

Huang, Jun-Lin; Zhou, Ke-Yi, E-mail: boiler@seu.edu.cn; Xu, Jian-Qun [Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu Province (China); Wang, Xin-Meng; Tu, Yi-You [School of Materials Science and Engineering, Southeast University, Nanjing 210096, Jiangsu Province (China)

2014-07-28

Failure of steam-side oxide scales on boiler tubes can seriously influence the safety of coal-fired power plants. Uniaxial tensile tests employing acoustic emission (AE) monitoring were performed, in this work, to investigate the failure behavior of steam-side oxide scales on T22 alloy boiler superheater tubes. The characteristic frequency spectra of the captured AE signals were obtained by performing fast Fourier transform. Three distinct peak frequency bands, 100-170, 175-250, and 280-390 kHz, encountered in different testing stages were identified in the frequency spectra, which were confirmed to, respectively, correspond to substrate plastic deformation, oxide vertical cracking, and oxide spalling with the aid of scanning electronic microscopy observations, and can thus be used for distinguishing different oxide failure mechanisms. Finally, the critical cracking strain of the oxide scale and the interfacial shear strength of the oxide/substrate interface were estimated, which are the critical parameters urgently desired for modeling the failure behavior of steam-side oxide scales on boiler tubes of coal-fired power plants.

Acoustic emission analysis on tensile failure of steam-side oxide scales formed on T22 alloy superheater tubes

Science.gov (United States)

Huang, Jun-Lin; Zhou, Ke-Yi; Wang, Xin-Meng; Tu, Yi-You; Xu, Jian-Qun

2014-07-01

Failure of steam-side oxide scales on boiler tubes can seriously influence the safety of coal-fired power plants. Uniaxial tensile tests employing acoustic emission (AE) monitoring were performed, in this work, to investigate the failure behavior of steam-side oxide scales on T22 alloy boiler superheater tubes. The characteristic frequency spectra of the captured AE signals were obtained by performing fast Fourier transform. Three distinct peak frequency bands, 100-170, 175-250, and 280-390 kHz, encountered in different testing stages were identified in the frequency spectra, which were confirmed to, respectively, correspond to substrate plastic deformation, oxide vertical cracking, and oxide spalling with the aid of scanning electronic microscopy observations, and can thus be used for distinguishing different oxide failure mechanisms. Finally, the critical cracking strain of the oxide scale and the interfacial shear strength of the oxide/substrate interface were estimated, which are the critical parameters urgently desired for modeling the failure behavior of steam-side oxide scales on boiler tubes of coal-fired power plants.

Acoustic emission analysis on tensile failure of steam-side oxide scales formed on T22 alloy superheater tubes

International Nuclear Information System (INIS)

Huang, Jun-Lin; Zhou, Ke-Yi; Xu, Jian-Qun; Wang, Xin-Meng; Tu, Yi-You

2014-01-01

Failure of steam-side oxide scales on boiler tubes can seriously influence the safety of coal-fired power plants. Uniaxial tensile tests employing acoustic emission (AE) monitoring were performed, in this work, to investigate the failure behavior of steam-side oxide scales on T22 alloy boiler superheater tubes. The characteristic frequency spectra of the captured AE signals were obtained by performing fast Fourier transform. Three distinct peak frequency bands, 100-170, 175-250, and 280-390 kHz, encountered in different testing stages were identified in the frequency spectra, which were confirmed to, respectively, correspond to substrate plastic deformation, oxide vertical cracking, and oxide spalling with the aid of scanning electronic microscopy observations, and can thus be used for distinguishing different oxide failure mechanisms. Finally, the critical cracking strain of the oxide scale and the interfacial shear strength of the oxide/substrate interface were estimated, which are the critical parameters urgently desired for modeling the failure behavior of steam-side oxide scales on boiler tubes of coal-fired power plants.

Microbial Community Composition and Ultrastructure of Granules from a Full-Scale Anammox Reactor

KAUST Repository

Gonzalez-Gil, Graciela

2014-12-11

Granules in anammox reactors contain besides anammox bacteria other microbial communities whose identity and relationship with the anammox bacteria are not well understood. High calcium concentrations are often supplied to anammox reactors to obtain sufficient bacterial aggregation and biomass retention. The aim of this study was to provide the first characterization of bacterial and archaeal communities in anammox granules from a full-scale anammox reactor and to explore on the possible role of calcium in such aggregates. High magnification imaging using backscattered electrons revealed that anammox bacteria may be embedded in calcium phosphate precipitates. Pyrosequencing of 16S rRNA gene fragments showed, besides anammox bacteria (Brocadiacea, 32 %), substantial numbers of heterotrophic bacteria Ignavibacteriacea (18 %) and Anaerolinea (7 %) along with heterotrophic denitrifiers Rhodocyclacea (9 %), Comamonadacea (3 %), and Shewanellacea (3 %) in the granules. It is hypothesized that these bacteria may form a network in which heterotrophic denitrifiers cooperate to achieve a well-functioning denitrification system as they can utilize the nitrate intrinsically produced by the anammox reaction. This network may provide a niche for the proliferation of archaea. Hydrogenotrophic methananogens, which scavenge the key fermentation product H2, were the most abundant archaea detected. Cells resembling the polygon-shaped denitrifying methanotroph Candidatus Methylomirabilis oxyfera were observed by electron microscopy. It is hypothesized that the anammox process in a full-scale reactor triggers various reactions overall leading to efficient denitrification and a sink of carbon as biomass in anammox granules.

Microbial community composition and ultrastructure of granules from a full-scale anammox reactor.

Science.gov (United States)

Gonzalez-Gil, Graciela; Sougrat, Rachid; Behzad, Ali R; Lens, Piet N L; Saikaly, Pascal E

2015-07-01

Granules in anammox reactors contain besides anammox bacteria other microbial communities whose identity and relationship with the anammox bacteria are not well understood. High calcium concentrations are often supplied to anammox reactors to obtain sufficient bacterial aggregation and biomass retention. The aim of this study was to provide the first characterization of bacterial and archaeal communities in anammox granules from a full-scale anammox reactor and to explore on the possible role of calcium in such aggregates. High magnification imaging using backscattered electrons revealed that anammox bacteria may be embedded in calcium phosphate precipitates. Pyrosequencing of 16S rRNA gene fragments showed, besides anammox bacteria (Brocadiacea, 32%), substantial numbers of heterotrophic bacteria Ignavibacteriacea (18%) and Anaerolinea (7%) along with heterotrophic denitrifiers Rhodocyclacea (9%), Comamonadacea (3%), and Shewanellacea (3%) in the granules. It is hypothesized that these bacteria may form a network in which heterotrophic denitrifiers cooperate to achieve a well-functioning denitrification system as they can utilize the nitrate intrinsically produced by the anammox reaction. This network may provide a niche for the proliferation of archaea. Hydrogenotrophic methananogens, which scavenge the key fermentation product H2, were the most abundant archaea detected. Cells resembling the polygon-shaped denitrifying methanotroph Candidatus Methylomirabilis oxyfera were observed by electron microscopy. It is hypothesized that the anammox process in a full-scale reactor triggers various reactions overall leading to efficient denitrification and a sink of carbon as biomass in anammox granules.

Full scale solvent extraction remedial results

International Nuclear Information System (INIS)

Cash, A.B.

1992-01-01

Sevenson Extraction Technology, Inc. has completed the development of the Soil Restoration Unit (initially developed by Terra-Kleen Corporation), a mobile, totally enclosed solvent extraction treatment facility for the removal of organic contaminated media is greater by a closed loop, counter current process that recycles all solvents. The solvents used are selected for the individual site dependant upon the contaminants, such as PCB's, oil, etc. and the soil conditions. A mixture of up to fourteen non-toxic solvents can be used for complicated sites. The full scale unit has been used to treat one superfund site, the Traband Site in Tulsa, Oklahoma, and is currently treating another superfund site, the Pinette's Salvage Yard Site in Washburn, Maine. The full scale Soil Restoration Unit has also been used at a non-superfund site, as part of a TSCA Research and Development permit. The results from these sites will be discussed in brief herein, and in more detail in the full paper

Evaluation of materials' corrosion and chemistry issues for advanced gas cooled reactor steam generators using full scale plant simulations

International Nuclear Information System (INIS)

Woolsey, I.S.; Rudge, A.J.; Vincent, D.J.

1998-01-01

Advanced Gas Cooled Reactors (AGRS) employ once-through steam Generators of unique design to provide steam at approximately 530 degrees C and 155 bar to steam turbines of similar design to those of fossil plants. The steam generators are highly compact, and have either a serpentine or helical tube geometry. The tubes are heated on the outside by hot C0 2 gas, and steam is generated on the inside of the tubes. Each individual steam generator tube consists of a carbon steel feed and primary economiser section, a 9%Cr steel secondary economiser, evaporator and primary superheater, and a Type 316L austenitic stainless steel secondary superheater, all within a single tube pass. The multi-material nature of the individual tube passes, the need to maintain specific thermohydraulic conditions within the different material sections, and the difficulties of steam generator inspection and repair, have required extensive corrosion-chemistry test programmes to ensure waterside corrosion does not present a challenge to their integrity. A major part of these programmes has been the use of a full scale steam generator test facility capable of simulating all aspects of the waterside conditions which exist in the plant. This facility has been used to address a wide variety of possible plant drainage/degradation processes. These include; single- and two-phase flow accelerated corrosion of carbon steel, superheat margins requirements and the stress-corrosion behaviour of the austenitic superheaters, on-load corrosion of the evaporator materials, and iron transport and oxide deposition behaviour. The paper outlines a number of these, and indicates how they have been of value in helping to maintain reliable operation of the plant. (author)

Production of U3O8 by uranyl formate precipitation and calcination in a full-scale pilot facility

International Nuclear Information System (INIS)

Kendrick, L.S.; Wilson, W.A.; Mosley, W.C.

1984-08-01

The uranyl formate process for the production of U 3 O 8 with a controlled particle size has been extensively studied on a laboratory scale. Based on this study, a pilot-scale facility (the Uranyl Formate Facility) was built to investigate the key steps of the process on a larger scale. These steps were the precipitation of a uranyl formate monohydrate salt and the calcination of this salt to U 3 O 8 . Tests of the facility and process were conducted at conditions recommended by the laboratory-scale studies for a full-scale production facility. These tests demonstrated that U 3 O 8 of the required particle size for the PM process can be produced on a plant scale by the calcination of uranyl formate crystals. The performance of the U 3 O 8 produced by the uranyl formate process in fuel tube fabrication was also investigated. Small-scale extrusion tests of U 3 O 8 -Al cores which used the U 3 O 8 produced in the Uranyl Formate Facility were conducted. These tests demonstrated that the U 3 O 8 quality was satisfactory for the PM process

High temperature ceramic-tubed reformer

Science.gov (United States)

Williams, Joseph J.; Rosenberg, Robert A.; McDonough, Lane J.

1990-03-01

The overall objective of the HiPHES project is to develop an advanced high-pressure heat exchanger for a convective steam/methane reformer. The HiPHES steam/methane reformer is a convective, shell and tube type, catalytic reactor. The use of ceramic tubes will allow reaction temperature higher than the current state-of-the-art outlet temperatures of about 1600 F using metal tubes. Higher reaction temperatures increase feedstock conversion to synthesis gas and reduce energy requirements compared to currently available radiant-box type reformers using metal tubes. Reforming of natural gas is the principal method used to produce synthesis gas (primarily hydrogen and carbon monoxide, H2 and CO) which is used to produce hydrogen (for refinery upgrading), methanol, as well as several other important materials. The HiPHES reformer development is an extension of Stone and Webster's efforts to develop a metal-tubed convective reformer integrated with a gas turbine cycle.

Scramjet test flow reconstruction for a large-scale expansion tube, Part 2: axisymmetric CFD analysis

Science.gov (United States)

Gildfind, D. E.; Jacobs, P. A.; Morgan, R. G.; Chan, W. Y. K.; Gollan, R. J.

2017-11-01

This paper presents the second part of a study aiming to accurately characterise a Mach 10 scramjet test flow generated using a large free-piston-driven expansion tube. Part 1 described the experimental set-up, the quasi-one-dimensional simulation of the full facility, and the hybrid analysis technique used to compute the nozzle exit test flow properties. The second stage of the hybrid analysis applies the computed 1-D shock tube flow history as an inflow to a high-fidelity two-dimensional-axisymmetric analysis of the acceleration tube. The acceleration tube exit flow history is then applied as an inflow to a further refined axisymmetric nozzle model, providing the final nozzle exit test flow properties and thereby completing the analysis. This paper presents the results of the axisymmetric analyses. These simulations are shown to closely reproduce experimentally measured shock speeds and acceleration tube static pressure histories, as well as nozzle centreline static and impact pressure histories. The hybrid scheme less successfully predicts the diameter of the core test flow; however, this property is readily measured through experimental pitot surveys. In combination, the full test flow history can be accurately determined.

Single-stage micro-scale solvent extraction in parallel microbore tubes using MDIMJ

International Nuclear Information System (INIS)

Darekar, Mayur; Singh, K.K.; Joshi, J.M.; Mukhopadhyay, S.; Shenoy, K.T.

2016-01-01

Single-stage micro-scale solvent extraction of U(VI) from simulated lean streams is explored using micro-scale contactor comprising of a MDIMJ (Monoblock Distributor with Integrated Microfluidic Junction) and PTFE microbore tubes. 30% (v/v) TBP in dodecane has been used as the extracting phase. The objective of the study is to demonstrate numbering up approach for scale-up of micro-scale extraction using indigenously conceptualized and fabricated MDIMJ. First the performance of MIDIMJ for equal flow distribution is tested. Then the effects of inlet flow rate and O/A ratio on stage efficiency and percentage extraction are studied. The experiments show that it is easy to scale-up single-stage micro-scale solvent extraction by using MDIMJ for numbering up approach. Maximum capacity tested is 4.8 LPH. With O/A = 2/1, more than 90% extraction is achieved in a very short contact time of less than 3s. The study thus demonstrates possibility of process intensification and easy scale-up of micro-scale solvent extraction

Large-Scale Fabrication of Boron Nitride Nanotubes via a Facile Chemical Vapor Reaction Route and Their Cathodoluminescence Properties

Directory of Open Access Journals (Sweden)

Zhong Bo

2011-01-01

Full Text Available Abstract Cylinder- and bamboo-shaped boron nitride nanotubes (BNNTs have been synthesized in large scale via a facile chemical vapor reaction route using ammonia borane as a precursor. The structure and chemical composition of the as-synthesized BNNTs are extensively characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and selected-area electron diffraction. The cylinder-shaped BNNTs have an average diameter of about 100 nm and length of hundreds of microns, while the bamboo-shaped BNNTs are 100–500 nm in diameter with length up to tens of microns. The formation mechanism of the BNNTs has been explored on the basis of our experimental observations and a growth model has been proposed accordingly. Ultraviolet–visible and cathodoluminescence spectroscopic analyses are performed on the BNNTs. Strong ultraviolet emissions are detected on both morphologies of BNNTs. The band gap of the BNNTs are around 5.82 eV and nearly unaffected by tube morphology. There exist two intermediate bands in the band gap of BNNTs, which could be distinguishably assigned to structural defects and chemical impurities. Additional file 1 Click here for file

Busbar arcs at large fusion magnets: Conductor to feeder tube arcing model experiments with the LONGARC device

Energy Technology Data Exchange (ETDEWEB)

Klimenko, Dmitry, E-mail: dmitry.klimenko@kit.edu; Pasler, Volker

2014-10-15

Highlights: •The LONGARC device was successfully implemented for busbar to feeder tubes arcing model experiments. •Arcing at an ITER busbar inside its feeder tube was simulated in scaled model experiments. •The narrower half tubes imply a slight increase of the arc propagation speed in compare to full tube experiments. •All simulated half tubes experiments show severe damage indicating that the ITER inner feeder tube will not withstand a busbar arc. -- Abstract: Electric arcs moving along the power cables (the so-called busbars) of the toroidal field (TF) coils of ITER may reach and penetrate the cryostat wall. Model experiments with the new LONGARC device continue the VACARC (VACuum ARC) experiments that were initiated to investigate the propagation and destruction mechanisms of busbar arcs in small scale [1]. The experiments are intended to support the development and validation of a numerical model. LONGARC overcomes the space limitations inside VACARC and allows also for advanced 1:3 (vs. ITER full scale) model setups. The LONGARC device and first results are presented below.

Boreside rotating ultrasonic tester for wastage determination of LMFBR-type steam generator tubes

International Nuclear Information System (INIS)

Neely, H.H.; Renger, H.L.

1979-01-01

Large sodium-water reaction (SWR) leak tests are being run in near-prototypic steam generators at prototypic plant conditions of the Liquid Metal Fast Breeder Reactor (LMFBR). These tests simulate various types of steam tube failure at predetermined locations. A SWR results in a highly energetic-exothermic-caustic reaction which erodes neighboring tubes. A boreside-rotating ultrasonic inspection device was developed to measure wall thickness and inside diameter of the 2/one quarter/Cr-1 Mo, 10.1 mm I.D. steam tubes. Rotation of the UT beam yields a complimentary scan of the full tube in a single pass. The UT system was designed with a 15 MHz transducer in pulse-echo compression-wave mode at a pulse rate of 10,000/second. The UT beam is rotated at 20 r/s on a 1.27 mm pitch. System outputs are diameter, wall thickness, attitude, and axial position. Measurements are processed, then fed to a CRT and computer for later retrieval and plotting

Type I fitting of copper tubes from a water distribution system

CSIR Research Space (South Africa)

Fernandes, PJL

1998-03-01

Full Text Available with a greenish scale of a copper compound called malachite. Beneath this scale, the tube surface is covered with a smooth, shiny layer of dark cuprite which is very friable and easily spalled off. Pits are usually...

Pelamis WEC - full-scale joint system test

Energy Technology Data Exchange (ETDEWEB)

Yemm, R.

2003-07-01

This report describes the building and testing of a full-scale Pelamis Wave Energy Converter (WEC) two-axis joint system using a laboratory joint test rig. The main project objective to develop an intermediate demonstration model to confirm full scale control, hydraulic and data acquisition systems is discussed, and the key objectives of the programme are listed. Details are given of the semi-submerged articulated structure of cylindrical elements linked by hinged joints, and the integrated testing of all key components. A summary of the work programme and a description of the test rig are presented.

Full-course drug challenge test in the diagnosis of delayed allergic reactions to penicillin.

Science.gov (United States)

Borch, Jakob E; Bindslev-Jensen, Carsten

2011-01-01

Drug challenge test (DCT) has long been the most sensitive test in the allergological work-up when investigating for penicillin allergy. To improve sensitivity of the diagnostic work-up in diagnosing penicillin allergics with histories of allergic reactions on day 2 or later in the course of penicillin treatment. A full-course DCT was added to the current protocol if specific IgE, skin tests and DCT were all negative in patients who had a nonimmediate reaction to penicillin treatment. Sixteen patients with a history of an immediate reaction to penicillin treatment underwent testing with negative outcomes. Fifty percent of patients undergoing full-course DCT experienced a cutaneous adverse drug reaction. None of the controls reacted (p = 0.001). The mean time of reaction was 6 days. Penicillin V accounted for most reactions. Urticaria was the most frequent clinical reaction observed. Full-course DCT offers an improvement of sensitivity and predictive values of the diagnostic work-up of allergic reactions to penicillin occurring on day 2 of penicillin treatment or later. Copyright © 2011 S. Karger AG, Basel.

Experimental and theoretical investigations on safety of the SNR - straight-tube design steam generator with sodium-water reactions

International Nuclear Information System (INIS)

Dumm, K.; Sauermann, F.; Schnitker, W.; Welter, A.

A number of large sodium-water reaction tests has been performed in a steam generator model in order to verify the layout criteria of the SNR straight-tube design steam generators under accident conditions. The experimental setup is described. The test results and their applicability to the SNR steam generators are given and discussed. (U.S.)

Bacterial communities in full-scale wastewater treatment systems

OpenAIRE

Cydzik-Kwiatkowska, Agnieszka; Zieli?ska, Magdalena

2016-01-01

Bacterial metabolism determines the effectiveness of biological treatment of wastewater. Therefore, it is important to define the relations between the species structure and the performance of full-scale installations. Although there is much laboratory data on microbial consortia, our understanding of dependencies between the microbial structure and operational parameters of full-scale wastewater treatment plants (WWTP) is limited. This mini-review presents the types of microbial consortia in...

Meta-analysis to obtain a scale of psychological reaction after perinatal loss: focus on miscarriage

Directory of Open Access Journals (Sweden)

Annsofie Adolfsson

2011-03-01

Full Text Available Annsofie Adolfsson1,21School of Life Sciences, University of Skövde, 2Department of Obstetrics and Gynecology, Skaraborg Hospital, Skövde, SwedenAbstract: Pregnancy has different meanings to different women depending upon their circumstances. A number of qualitative studies have described the experience of miscarriage by women who had desired to carry their pregnancy to full term. The aim of this meta-analysis was to identify a scale of psychological reaction to miscarriage. Meta-analysis is a quantitative approach for reviewing articles from scientific journals through statistical analysis of findings from individual studies. In this review, a meta-analytic method was used to identify and analyze psychological reactions in women who have suffered a miscarriage. Different reactions to stress associated with the period following miscarriage were identified. The depression reaction had the highest average, weighted, unbiased estimate of effect (d+ = 0.99 and was frequently associated with the experience of perinatal loss. Psychiatric morbidity was found after miscarriage in 27% of cases by a diagnostic interview ten days after miscarriage. The grief reaction had a medium d+ of 0.56 in the studies included. However, grief after miscarriage differed from other types of grief after perinatal loss because the parents had no focus for their grief. The guilt is greater after miscarriage than after other types of perinatal loss. Measurement of the stress reaction and anxiety reaction seems to be difficult in the included studies, as evidenced by a low d+ (0.17 and 0.16, respectively. It has been recommended that grief after perinatal loss be measured by an adapted instrument called the Perinatal Grief Scale Short Version.Keywords: psychological, perinatal loss, pregnancy, depression 

Mixed convection around calandria tubes in a ¼ scale CANDU-6 moderator circulation tank

Energy Technology Data Exchange (ETDEWEB)

Atkins, M.D.; Rossouw, D.J.; Boer, M. [Nuclear Science Division, School of Mechanical and Aeronautical Engineering, University of the Witwatersrand, Johannesburg (South Africa); Kim, T., E-mail: tong.kim@wits.ac.za [Nuclear Science Division, School of Mechanical and Aeronautical Engineering, University of the Witwatersrand, Johannesburg (South Africa); Rhee, B.W.; Kim, H.T. [Severe Accident and PHWR Safety Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2017-05-15

Highlights: • A secondary jet is formed at a stagnation region and is directed towards the center of the MCT. • The secondary jet undergoes the significant dissipation and mixing due to calandria tubes (CTs). • Its cooling effectiveness is reduced on the CTs in the bottom of the MCT. • With forced convection dominance, peak heat transfer is on the upper CT surface. • With natural convection dominance, peak heat transfer is on the lower CT surface. - Abstract: This study experimentally characterizes mixed convection around calandria tubes (CTs) in a ¼ scale CANDU-6 moderator circulation tank (MCT) that uses air as the working fluid. In a full scale CANDU-6 reactor that undergoes a postulated dual failure with a loss-of-coolant accident without the emergency core cooling system available, mixed convection heat transfer occurs around the CTs. The cooling effectiveness of the moderator is diminished as an emergency heat sink if overheating eventually leads to film boiling. To prevent the onset of film boiling, local sub-cooling margins of the moderator needs to be maintained or else the critical heat flux should be increased. Circulating the moderator which interacts with the overheated CTs increases the heat transfer into the moderator which may suppress film boiling. The present experimental results demonstrate that the cooling effectiveness of the circulating moderator, in particular the secondary jet, is attenuated substantially as it is convected away from the inner wall towards the center of the MCT. The momentum of the secondary jet is diffused through the CTs. At a low jet Reynolds number, the secondary jet becomes ineffective so that some overheated CTs positioned in the other half of the MCT are cooled only by natural convection.

Full scale demonstration of air-purifying pavement

NARCIS (Netherlands)

Ballari, M.; Brouwers, H.J.H.

2013-01-01

Experiments concerning a full-scale demonstration of air purifying pavement in Hengelo, The Netherlands, are reported. The full width of the street was provided with concrete pavement containing TiO2 over a length of 150 m ("DeNOx street"). Another part of the street, about 100 m, was paved with

Full-scale leaching study of commercial reactor waste forms

International Nuclear Information System (INIS)

Kalb, P.D.; Colombo, P.

1984-01-01

This paper describes a full-scale leaching experiment which has been conducted at Brookhaven National Laboratory (BNL) to study the release of radionuclides from actual commercial reactor waste forms. While many studies characterizing the leaching behavior of simulated laboratory-scale waste forms have been performed, this program represents one of the first attempts in the United States to quantify activity releases for real, full-scale waste forms. 5 references, 5 figures, 1 table

Influence of reaction time on the structure of polyaniline synthesized on a pre-pilot scale

Directory of Open Access Journals (Sweden)

Maria Alice Carvalho Mazzeu

Full Text Available Abstract The aim of this work is to follow the structural variations of polyaniline (PAni obtained by chemical oxidation on a pre-pilot scale, with different reaction times. Synthesis of PAni is well known, but when it is carried out on a pre-pilot scale, several factors can lead to structural changes and understanding these changes is important to improve controls on the synthesis process. The polymers formed were characterized by spectroscopic techniques (Raman spectroscopy, Fourier Transform Infrared - FTIR and UV-Visible. Degree of oxidation and yield were calculated for each reaction time. The analysis by FTIR, the calculated degree of oxidation and the yield showed significant changes in polymer structure at reaction times of 65 and 80 min. This result was attributed to the excessive oxidation of PAni, with the breaking of its polymer chain. The changes observed in the structure of PAni gave subsidies to the optimization of the process of obtaining polyaniline by chemical synthesis.

Full-scale load tests of Pearl-Chain arches

DEFF Research Database (Denmark)

Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

2017-01-01

-Decks: First an investigation of the system’s elastic response (maximum load of 648kN), and second a demonstration of its collapse mechanism and ultimate capacity (maximum load of 970kN). The full-scale test showed formation of plastic hinges and clear warning signs are observed at 84% of the failure load......A full-scale load test is made of two Pearl-Chain (PC) concrete arches in order to evaluate the structural response and assess the design safety. Pearl-Chain structures and Pearl-Chain arches are invented and patented at the Technical University of Denmark. PC-Arches consist of specially designed....... The ultimate, experimental load capacity is 14% higher than the calculated mainly due to the assumed static system used for the calculation. In addition to the full-scale test bridge the first ever permanent PC-Bridge is erected in Denmark in 2015....

Reduced linear noise approximation for biochemical reaction networks with time-scale separation: The stochastic tQSSA+

Science.gov (United States)

Herath, Narmada; Del Vecchio, Domitilla

2018-03-01

Biochemical reaction networks often involve reactions that take place on different time scales, giving rise to "slow" and "fast" system variables. This property is widely used in the analysis of systems to obtain dynamical models with reduced dimensions. In this paper, we consider stochastic dynamics of biochemical reaction networks modeled using the Linear Noise Approximation (LNA). Under time-scale separation conditions, we obtain a reduced-order LNA that approximates both the slow and fast variables in the system. We mathematically prove that the first and second moments of this reduced-order model converge to those of the full system as the time-scale separation becomes large. These mathematical results, in particular, provide a rigorous justification to the accuracy of LNA models derived using the stochastic total quasi-steady state approximation (tQSSA). Since, in contrast to the stochastic tQSSA, our reduced-order model also provides approximations for the fast variable stochastic properties, we term our method the "stochastic tQSSA+". Finally, we demonstrate the application of our approach on two biochemical network motifs found in gene-regulatory and signal transduction networks.

Bacterial communities in full-scale wastewater treatment systems.

Science.gov (United States)

Cydzik-Kwiatkowska, Agnieszka; Zielińska, Magdalena

2016-04-01

Bacterial metabolism determines the effectiveness of biological treatment of wastewater. Therefore, it is important to define the relations between the species structure and the performance of full-scale installations. Although there is much laboratory data on microbial consortia, our understanding of dependencies between the microbial structure and operational parameters of full-scale wastewater treatment plants (WWTP) is limited. This mini-review presents the types of microbial consortia in WWTP. Information is given on extracellular polymeric substances production as factor that is key for formation of spatial structures of microorganisms. Additionally, we discuss data on microbial groups including nitrifiers, denitrifiers, Anammox bacteria, and phosphate- and glycogen-accumulating bacteria in full-scale aerobic systems that was obtained with the use of molecular techniques, including high-throughput sequencing, to shed light on dependencies between the microbial ecology of biomass and the overall efficiency and functional stability of wastewater treatment systems. Sludge bulking in WWTPs is addressed, as well as the microbial composition of consortia involved in antibiotic and micropollutant removal.

ARKTOS full-scale evacuation tests

Energy Technology Data Exchange (ETDEWEB)

Seligman, B.; Hatfield, P. [ARKTOS Developments Ltd., Surrey, BC (Canada); Bercha, F. [Bercha Group, Calgary, AB (Canada)

2008-09-15

The ARKTOS amphibious vehicle can be used for evacuation operations in both open water and ice conditions. It is approved as an evacuation system by various regulators, such as the United States Coast Guard, and is operational in several marine cold regions as an escape, evacuation, and rescue (EER) system. An EER research project was performed in 2006 that provided a general reliability evaluation of the ARKTOS system. However, the project did not have the benefit of detailed full-scale tests in order to validate the associated computer model in drill or non-life threatening evacuation conditions. This paper described a follow-up set of full-scale evacuation tests designed to provide more detailed information and validation data for the reliability that the computer model described in the 2006 research project. A description and photographic illustrations of the ARKTOS system were presented. The tests and subsequent analyses were described. Specifically, the paper described the observations, and presented the statistical results from the data collected, and compared observed results with predicted results of a probabilistic EER simulation computer model. Conclusions and recommendations for reliability improvements were also provided. It was concluded that under the benign conditions, the drill performance was satisfactory in all aspects, both in the evacuation activities and the rescue or de-boarding activities. 3 refs., 1 tab., 17 figs.

Airframe Noise Prediction of a Full Aircraft in Model and Full Scale Using a Lattice Boltzmann Approach

Science.gov (United States)

Fares, Ehab; Duda, Benjamin; Khorrami, Mehdi R.

2016-01-01

Unsteady flow computations are presented for a Gulfstream aircraft model in landing configuration, i.e., flap deflected 39deg and main landing gear deployed. The simulations employ the lattice Boltzmann solver PowerFLOW(Trademark) to simultaneously capture the flow physics and acoustics in the near field. Sound propagation to the far field is obtained using a Ffowcs Williams and Hawkings acoustic analogy approach. Two geometry representations of the same aircraft are analyzed: an 18% scale, high-fidelity, semi-span model at wind tunnel Reynolds number and a full-scale, full-span model at half-flight Reynolds number. Previously published and newly generated model-scale results are presented; all full-scale data are disclosed here for the first time. Reynolds number and geometrical fidelity effects are carefully examined to discern aerodynamic and aeroacoustic trends with a special focus on the scaling of surface pressure fluctuations and farfield noise. An additional study of the effects of geometrical detail on farfield noise is also documented. The present investigation reveals that, overall, the model-scale and full-scale aeroacoustic results compare rather well. Nevertheless, the study also highlights that finer geometrical details that are typically not captured at model scales can have a non-negligible contribution to the farfield noise signature.

Pressure loss characteristics of LSTF steam generator heat-transfer tubes. Pressure loss increase due to tube internal instruments

International Nuclear Information System (INIS)

Suzuki, Mitsuhiro

1994-11-01

The steam generator of the Large-Scale Test Facility (LSTF) includes 141 heat-transfer U-tubes with different lengths. Six U-tubes among them are furnished with 15 or 17 probe-type instruments (conduction probe with a thermocouple; CPT) protuberant into the primary side of the U-tubes. Other 135 U-tubes are not instrumented. This results in different hydraulic conditions between the instrumented and non-instrumented U-tubes with the same length. A series of pressure loss characteristics tests was conducted at a test apparatus simulating both types of U-tube. The following pressure loss coefficient (K CPT ) was reduced as a function of Reynolds number (Re) from these tests under single-phase water flow conditions. K CPT =0.16 5600≤Re≤52820, K CPT =60.66xRe -0.688 2420≤Re≤5600, K CPT =2.664x10 6 Re -2.06 1371≤Re≤2420. The maximum uncertainty is 22%. By using these results, the total pressure loss coefficients of full length U-tubes were estimated. It is clarified that the total pressure loss of the shortest instrumented U-tube is equivalent to that of the middle-length non-instrumented U-tube and also that a middle-length instrumented U-tube is equivalent to the longest non-instrumented U-tube. Concludingly. it is important to take account of the CPT pressure loss mentioned above in estimation of fluid behavior at the non-instrumented U-tubes either by using the LSTF experiment data from the CPT-installed U-tubes or by using any analytical codes. (author)

Pore-scale studies of multiphase flow and reaction involving CO2 sequestration in geologic formations

Science.gov (United States)

Kang, Q.; Wang, M.; Lichtner, P. C.

2008-12-01

In geologic CO2 sequestration, pore-scale interfacial phenomena ultimately govern the key processes of fluid mobility, chemical transport, adsorption, and reaction. However, spatial heterogeneity at the pore scale cannot be resolved at the continuum scale, where averaging occurs over length scales much larger than typical pore sizes. Natural porous media, such as sedimentary rocks and other geological media encountered in subsurface formations, are inherently heterogeneous. This pore-scale heterogeneity can produce variabilities in flow, transport, and reaction processes that take place within a porous medium, and can result in spatial variations in fluid velocity, aqueous concentrations, and reaction rates. Consequently, the unresolved spatial heterogeneity at the pore scale may be important for reactive transport modeling at the larger scale. In addition, current continuum models of surface complexation reactions ignore a fundamental property of physical systems, namely conservation of charge. Therefore, to better understand multiphase flow and reaction involving CO2 sequestration in geologic formations, it is necessary to quantitatively investigate the influence of the pore-scale heterogeneity on the emergent behavior at the field scale. We have applied the lattice Boltzmann method to simulating the injection of CO2 saturated brine or supercritical CO2 into geological formations at the pore scale. Multiple pore-scale processes, including advection, diffusion, homogeneous reactions among multiple aqueous species, heterogeneous reactions between the aqueous solution and minerals, ion exchange and surface complexation, as well as changes in solid and pore geometry are all taken into account. The rich pore scale information will provide a basis for upscaling to the continuum scale.

Formability of Micro-Tubes in Hydroforming

International Nuclear Information System (INIS)

Hartl, Christoph; Anyasodor, Gerald; Lungershausen, Joern

2011-01-01

Micro-hydroforming is a down-scaled metal forming process, based on the expansion of micro-tubes by internal pressurization within a die cavity. The objective of micro-hydroforming is to provide a technology for the economic mass production of complex shaped hollow micro-components. Influence of size effects in metal forming processes increases with scaling down of metal parts. Investigations into the change in formability of micro-tubes due to metal part scaling down constituted an important subject within the conducted fundamental research work. Experimental results are presented, concerning the analysis of the formability of micro-tubes made from stainless steel AISI 304 with an outer diameter of 800 μm and a wall thickness of 40 μm. An average ratio of tube wall thickness to grain size of 1.54 of up to 2.56 was analyzed. Miniaturised mechanical standard methods as well as bulge tests with internal hydrostatic pressurization of the tubular specimens were applied to analyze the influence of size-dependent effects. A test device was developed for the bulge experiments which enabled the pressurization of micro-tubes with internal pressures up to 4000 bar. To determine the attainable maximum achievable expansion ratio the tubes were pressurized in the bulge tests with increasing internal pressure until instability due to necking and subsequent bursting occurred. Comparisons with corresponding tests of macro-tubes, made from the here investigated material, showed a change in formability of micro-tubes which was attributed to the scaling down of the hydroforming process. In addition, a restricted applicability of existing theoretical correlations for the determination of the maximum pressure at bursting was observed for down-scaled micro-hydroforming.

Competitive Association and Charge Transfer in the Reactions of NO + with some Ketones: a Select Ion Flow Drift Tube Study

Czech Academy of Sciences Publication Activity Database

Fairley, D. A.; Milligan, D. B.; Freeman, C. G.; McEwan, M. J.; Španěl, Patrik; Smith, D.

1999-01-01

Roč. 193, č. 1 (1999), s. 35-43 ISSN 1387-3806 Grant - others:Marsden Fund(NZ) - Institutional research plan: CEZ:A54/98:Z4-040-9-ii Keywords : ion-molecule reaction kinetics * selected ion flow drift tube * ternary association Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.086, year: 1999

Scramjet test flow reconstruction for a large-scale expansion tube, Part 1: quasi-one-dimensional modelling

Science.gov (United States)

Gildfind, D. E.; Jacobs, P. A.; Morgan, R. G.; Chan, W. Y. K.; Gollan, R. J.

2017-11-01

Large-scale free-piston driven expansion tubes have uniquely high total pressure capabilities which make them an important resource for development of access-to-space scramjet engine technology. However, many aspects of their operation are complex, and their test flows are fundamentally unsteady and difficult to measure. While computational fluid dynamics methods provide an important tool for quantifying these flows, these calculations become very expensive with increasing facility size and therefore have to be carefully constructed to ensure sufficient accuracy is achieved within feasible computational times. This study examines modelling strategies for a Mach 10 scramjet test condition developed for The University of Queensland's X3 facility. The present paper outlines the challenges associated with test flow reconstruction, describes the experimental set-up for the X3 experiments, and then details the development of an experimentally tuned quasi-one-dimensional CFD model of the full facility. The 1-D model, which accurately captures longitudinal wave processes, is used to calculate the transient flow history in the shock tube. This becomes the inflow to a higher-fidelity 2-D axisymmetric simulation of the downstream facility, detailed in the Part 2 companion paper, leading to a validated, fully defined nozzle exit test flow.

Scramjet test flow reconstruction for a large-scale expansion tube, Part 1: quasi-one-dimensional modelling

Science.gov (United States)

Gildfind, D. E.; Jacobs, P. A.; Morgan, R. G.; Chan, W. Y. K.; Gollan, R. J.

2018-07-01

Large-scale free-piston driven expansion tubes have uniquely high total pressure capabilities which make them an important resource for development of access-to-space scramjet engine technology. However, many aspects of their operation are complex, and their test flows are fundamentally unsteady and difficult to measure. While computational fluid dynamics methods provide an important tool for quantifying these flows, these calculations become very expensive with increasing facility size and therefore have to be carefully constructed to ensure sufficient accuracy is achieved within feasible computational times. This study examines modelling strategies for a Mach 10 scramjet test condition developed for The University of Queensland's X3 facility. The present paper outlines the challenges associated with test flow reconstruction, describes the experimental set-up for the X3 experiments, and then details the development of an experimentally tuned quasi-one-dimensional CFD model of the full facility. The 1-D model, which accurately captures longitudinal wave processes, is used to calculate the transient flow history in the shock tube. This becomes the inflow to a higher-fidelity 2-D axisymmetric simulation of the downstream facility, detailed in the Part 2 companion paper, leading to a validated, fully defined nozzle exit test flow.

Scale-up of counter-current chromatography: demonstration of predictable isocratic and quasi-continuous operating modes from the test tube to pilot/process scale.

Science.gov (United States)

Sutherland, Ian; Hewitson, Peter; Ignatova, Svetlana

2009-12-11

Predictable scale-up from test tube derived distribution ratios and analytical-scale sample loading optimisation is demonstrated using a model sample system of benzyl alcohol and p-cresol in a heptane:ethyl acetate:methanol:water phase system with the new 18 L Maxi counter-current chromatography centrifuge. The versatility of having a liquid stationary phase with its high loading capacity and flexible operating modes is demonstrated at two different scales by separating and concentrating target compounds using a mixture of caffeine, vanillin, naringenin and carvone using a quasi-continuous technique called intermittent counter-current extraction.

Scaling Phenomena in Desalination With Multi Stage Flash Distillation (MSF)

International Nuclear Information System (INIS)

Siti-Alimah

2006-01-01

Assessment of scaling phenomena in MSF desalination has been carried out. Scale is one of predominantly problem in multi stage flash (MSF) desalination installation. The main types of scale in MSF are carbonate calcium (CaCO 3 ), hydroxide magnesium (Mg(OH) 2 ) and sulphate calcium (CaSO 4 ). CaCO 3 and Mg(OH) 2 scales result from the thermal decomposition of bicarbonate ion, however sulphate calcium scale result from reaction of calcium ion and sulfate ion present in seawater. The rate of formation scale in seawater depends on temperature, pH, concentration of ions, supersaturated solution, nucleation and diffusion. The scales in MSF installation can occur inside heat exchanger tube, brine heater tubes, water boxes, on the face of tube sheets and demister pads. Scaling reduces effectiveness (production and heat consumption) of the process. To avoid the reductions in performance caused by scale precipitation, desalination units employ scale control. To control this scaling problem, the following methods can be used; acid, additive (scale inhibitors) and mechanical cleaning. Stoichiometric amounts of acid must be added to seawater, because addition excess of acid will increase corrosion problems. Using of scale inhibitors as polyphosphates, phosphonates, polyacrylates and poly maleates have advantage and disadvantage. (author)

A full understanding of oxygen reduction reaction mechanism on Au(1 1 1) surface

Science.gov (United States)

Yang, Yang; Dai, Changqing; Fisher, Adrian; Shen, Yanchun; Cheng, Daojian

2017-09-01

Oxygen reduction and hydrogen peroxide reduction are technologically important reactions in energy-conversion devices. In this work, a full understanding of oxygen reduction reaction (ORR) mechanism on Au(1 1 1) surface is investigated by density functional theory (DFT) calculations, including the reaction mechanisms of O2 dissociation, OOH dissociation, and H2O2 dissociation. Among these ORR mechanisms on Au(1 1 1), the activation energy of \\text{O}2* hydrogenation reaction is much lower than that of \\text{O}2* dissociation, indicating that \\text{O}2* hydrogenation reaction is more appropriate at the first step than \\text{O}2* dissociation. In the following, H2O2 can be formed with the lower activation energy compared with the OOH dissociation reaction, and finally H2O2 could be generated as a detectable product due to the high activation energy of H2O2 dissociation reaction. Furthermore, the potential dependent free energy study suggests that the H2O2 formation is thermodynamically favorable up to 0.4 V on Au(1 1 1), reducing the overpotential for 2e - ORR process. And the elementary step of first H2O formation becomes non-spontaneous at 0.4 V, indicating the difficulty of 4e - reduction pathway. Our DFT calculations show that H2O2 can be generated on Au(1 1 1) and the first electron transfer is the rate determining step. Our results show that gold surface could be used as a good catalyst for small-scale manufacture and on-site production of H2O2.

Catalytic Chan–Lam coupling using a ‘tube-in-tube’ reactor to deliver molecular oxygen as an oxidant

Directory of Open Access Journals (Sweden)

Carl J. Mallia

2016-07-01

Full Text Available A flow system to perform Chan–Lam coupling reactions of various amines and arylboronic acids has been realised employing molecular oxygen as an oxidant for the re-oxidation of the copper catalyst enabling a catalytic process. A tube-in-tube gas reactor has been used to simplify the delivery of the oxygen accelerating the optimisation phase and allowing easy access to elevated pressures. A small exemplification library of heteroaromatic products has been prepared and the process has been shown to be robust over extended reaction times.

Rate constants of chemical reactions from semiclassical transition state theory in full and one dimension

Energy Technology Data Exchange (ETDEWEB)

Greene, Samuel M., E-mail: samuel.greene@chem.ox.ac.uk; Shan, Xiao, E-mail: xiao.shan@chem.ox.ac.uk; Clary, David C., E-mail: david.clary@chem.ox.ac.u [Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom)

2016-06-28

Semiclassical Transition State Theory (SCTST), a method for calculating rate constants of chemical reactions, offers gains in computational efficiency relative to more accurate quantum scattering methods. In full-dimensional (FD) SCTST, reaction probabilities are calculated from third and fourth potential derivatives along all vibrational degrees of freedom. However, the computational cost of FD SCTST scales unfavorably with system size, which prohibits its application to larger systems. In this study, the accuracy and efficiency of 1-D SCTST, in which only third and fourth derivatives along the reaction mode are used, are investigated in comparison to those of FD SCTST. Potential derivatives are obtained from numerical ab initio Hessian matrix calculations at the MP2/cc-pVTZ level of theory, and Richardson extrapolation is applied to improve the accuracy of these derivatives. Reaction barriers are calculated at the CCSD(T)/cc-pVTZ level. Results from FD SCTST agree with results from previous theoretical and experimental studies when Richardson extrapolation is applied. Results from our implementation of 1-D SCTST, which uses only 4 single-point MP2/cc-pVTZ energy calculations in addition to those for conventional TST, agree with FD results to within a factor of 5 at 250 K. This degree of agreement and the efficiency of the 1-D method suggest its potential as a means of approximating rate constants for systems too large for existing quantum scattering methods.

Simulation in full-scale mock-ups: an ergonomics evaluation method?

DEFF Research Database (Denmark)

Andersen, Simone Nyholm; Broberg, Ole

2014-01-01

This paper presents and exploratory study of four simulation sessions in full-scale mock-ups of future hospital facilities.......This paper presents and exploratory study of four simulation sessions in full-scale mock-ups of future hospital facilities....

Thermomechanical Model and Bursting Tests to Evaluate the Risk of Swelling and Bursting of Modified 9Cr-1Mo Steel Steam Generator Tubes during a Sodium-Water Reaction Accident

Directory of Open Access Journals (Sweden)

C. Bertrand

2014-01-01

Full Text Available The MECTUB code was developed to evaluate the risk of swelling and bursting of Steam Generator (SG tubes. This code deals with the physic of intermediate steam-water leaks into sodium which induce a Sodium-Water Reaction (SWR. It is based on a one-dimensional calculation to describe the thermomechanical behavior of tubes under a high internal pressure and a fast external overheating. The mechanical model of MECTUB is strongly correlated with the kind of the material of the SG tubes. It has been developed and validated by using experiments performed on the alloy 800. A change to tubes made of Modified 9Cr-1Mo steel requires more knowledge of Modified 9Cr-1Mo steel behavior which influences the bursting time at high temperatures (up to 1200°C. Studies have been initiated to adapt the mechanical model and to qualify it for this material. The first part of this paper focuses on the mechanical law modelling (elasticity, plasticity, and creep for Modified 9Cr-1Mo steel and on overheating thermal data. In a second part, the results of bursting tests performed on Modified 9Cr-1Mo tubes in the SQUAT facility of CEA are used to validate the mechanical model of MECTUB for the Modified 9Cr-1Mo material.

Corrosion of Steels in the Vicinity of a Sodium-Water Reaction

Energy Technology Data Exchange (ETDEWEB)

Davies, R. A.; Bray, J. A.; Lyons, J. M. [U.K. Atomic Energy Authority, Dounreay Experimental Reactor Establishment, Thurso, Caithness (United Kingdom)

1967-06-15

Rapid corrosion of steels in the vicinity of a sodium-water reaction could lead to a major reaction in a sodium-water heat exchanger. An investigation of the magnitude of the corrosion problem has been carried out under conditions simulating both a small water leak and a full size pipe burst, and further tube failures have been obtained. These experiments were carried out on a sodium rig which could accommodate simple full-scale models of sections of heat exchanger, and up to 70 lb of water was injected into 700 lb of sodium in 9.0s. The corrosion phenomena have also been investigated on a small scale under more controllable conditions by pumping water at normal pressures into a pot of sodium. With a flow-rate of 1 ml/min corrosion rates in excess of 0.005 in./min have been obtained. The effect of various parameters on the corrosion rate has been studied, and a comparison has been made of the corrosion rates obtained with a variety of steels. The corrosion appears to be a direct result of conditions during the reaction, and the appearance of the specimen and pattern of damage suggests that the main effect is concentrated where the sodium water reaction front impinges on the metal surface. The corrosion rates are very much lower with stainless steel and nickel alloys than with ferritic materials, and suggest that the phenomena are associated with the formation of (Na{sub 2}O){sub 2}FeO. Iron powder has also been observed in the vicinity of the reaction which would suggest that this is reduced at a later stage, either as a result of the hydrogen produced during reaction, or by thermal cycling. (author)

Wear behavior of 2-1/4 Cr-1Mo tubing against alloy 718 tube-support material in sodium-cooled steam generators

International Nuclear Information System (INIS)

Wilson, W.L.

1983-05-01

A series of prototypic steam generator 2-1/4 Cr-1 Mo tube/alloy 718 tube support plate wear tests were conducted in direct support of the Westinghouse Nuclear Components Division -- Breeder Reactor Components Project Large Scale steam Generator design. The initial objective was to verify the acceptable wear behavior of softer, ''over-aged'' alloy 718 support plate material. For all interfaces under all test conditions, resultant wear damage was adhesive in nature with varying amounts of 2-1/4 Cr-1 Mo tube material being adhesively transferred to the alloy 718 tube supports. Maximum tube wear depths exceeded the initially established design allowable limit of 127 μm (.005 in.) at 17 of the 18 interfaces tested. A decrease in contact stresses produced acceptable tube wear depths below a readjusted maximum design allowable value of 381 μm (.015 in.). Additional conservatisms associated with the simulation of a 40-year lifetime of rubbing in a one-week laboratory test provided further confidence that the 381 μm maximum tube wear allowance would not be exceeded in service. Softer, ''over-aged'' alloy 718 material was found to produce slightly less wear damage on 2-1/4 Cr-1 Mo tubing than fully age hardened material. Also, air formed oxide films on the alloy 718 reduced initial tube wear and delayed the onset of adhesive surface damage. However, at high surface stress levels, these films were not sufficiently stable to provide adequate long term protection from adhesive wear. The results of the present work and those of previous test programs suggest that the successful in-sodium tribological performance of 2-1/4 Cr-1 Mo/alloy 718 rubbing couples is dependent upon the presence of lubricative surface films, such as oxides and/or surface reaction or deposition products. 11 refs., 13 figs., 4 tabs

Bench-scale Kinetics Study of Mercury Reactions in FGD Liquors

Energy Technology Data Exchange (ETDEWEB)

Gary Blythe; John Currie; David DeBerry

2008-03-31

This document is the final report for Cooperative Agreement DE-FC26-04NT42314, 'Kinetics Study of Mercury Reactions in FGD Liquors'. The project was co-funded by the U.S. DOE National Energy Technology Laboratory and EPRI. The objective of the project has been to determine the mechanisms and kinetics of the aqueous reactions of mercury absorbed by wet flue gas desulfurization (FGD) systems, and develop a kinetics model to predict mercury reactions in wet FGD systems. The model may be used to determine optimum wet FGD design and operating conditions to maximize mercury capture in wet FGD systems. Initially, a series of bench-top, liquid-phase reactor tests were conducted and mercury species concentrations were measured by UV/visible light spectroscopy to determine reactant and byproduct concentrations over time. Other measurement methods, such as atomic absorption, were used to measure concentrations of vapor-phase elemental mercury, that cannot be measured by UV/visible light spectroscopy. Next, a series of bench-scale wet FGD simulation tests were conducted. Because of the significant effects of sulfite concentration on mercury re-emission rates, new methods were developed for operating and controlling the bench-scale FGD experiments. Approximately 140 bench-scale wet FGD tests were conducted and several unusual and pertinent effects of process chemistry on mercury re-emissions were identified and characterized. These data have been used to develop an empirically adjusted, theoretically based kinetics model to predict mercury species reactions in wet FGD systems. The model has been verified in tests conducted with the bench-scale wet FGD system, where both gas-phase and liquid-phase mercury concentrations were measured to determine if the model accurately predicts the tendency for mercury re-emissions. This report presents and discusses results from the initial laboratory kinetics measurements, the bench-scale wet FGD tests, and the kinetics modeling

Cyanobacteria, Toxins and Indicators: Full-Scale Monitoring & Bench-Scale Treatment Studies

Science.gov (United States)

Summary of: 1) Lake Erie 2014 bloom season full-scale treatment plant monitoring data for cyanobacteria and cyanobacteria toxins; 2) Follow-up work to examine the impact of pre-oxidation on suspensions of intact toxin-producing cyanobacterial cells.

OPAL jet chamber full scale prototype

Energy Technology Data Exchange (ETDEWEB)

Fischer, H M; Hauschild, M; Hartmann, H; Hegerath, A; Boerner, H; Burckhart, H J; Dittmar, M; Hammarstroem, R; Heuer, R D; Mazzone, L

1986-12-01

The concept of a jet chamber for the central detector of OPAL has been tested with a full scale prototype. The design of this prototype, its mechanical and electrical structure and its support system for high voltage, gas, laser calibration and readout are described. Operating experience has been gathered since summer 1984. The chamber performance in terms of spatial resolution and particle identification capability is given.

OPAL jet chamber full-scale prototype

Energy Technology Data Exchange (ETDEWEB)

Fischer, H M; Hauschild, M; Hartmann, H; Hegerath, A; Boerner, H; Burckhart, H J; Dittmar, M; Hammarstroem, R; Heuer, R D; Mazzone, L

1986-12-01

The concept of a jet chamber for the central detector of OPAL was tested with a full scale prototype. The design of this prototype, its mechanical and electrical structure and its support system for high voltage, gas, laser calibration, and readout are described. Operating experience was gathered since summer 1984. The chamber performance in terms of spatial resolution and particle identification capability is given.

Analysis, scale modeling, and full-scale tests of low-level nuclear-waste-drum response to accident environments

International Nuclear Information System (INIS)

Huerta, M.; Lamoreaux, G.H.; Romesberg, L.E.; Yoshimura, H.R.; Joseph, B.J.; May, R.A.

1983-01-01

This report describes extensive full-scale and scale-model testing of 55-gallon drums used for shipping low-level radioactive waste materials. The tests conducted include static crush, single-can impact tests, and side impact tests of eight stacked drums. Static crush forces were measured and crush energies calculated. The tests were performed in full-, quarter-, and eighth-scale with different types of waste materials. The full-scale drums were modeled with standard food product cans. The response of the containers is reported in terms of drum deformations and lid behavior. The results of the scale model tests are correlated to the results of the full-scale drums. Two computer techniques for calculating the response of drum stacks are presented. 83 figures, 9 tables

Spectral Analysis of CO2 Corrosion Product Scales on 13Cr Tubing Steel

International Nuclear Information System (INIS)

Guan-fa, Lin; Zhen-quan, Bai; Yao-rong, Feng; Xun-yuan, Xu

2008-01-01

CO 2 corrosion product scales formed on 13 Cr tubing steel in autoclave and in the simulated corrosion environment of oil field are investigated in the paper. The surface and cross-section profiles of the scales were observed by scanning electron microscopy (SEM), the chemical compositions of the scales were analyzed using energy dispersion analyzer of X-ray (EDAX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) to confirm the corrosion mechanism of the 13 Cr steel in the simulated CO 2 corrosion environment. The results show that the corrosion scales are formed by the way of fashion corrosion, consist mainly of four elements, i.e. Fe, Cr, C and O, and with a double-layer structure, in which the surface layer is constituted of bulky and incompact crystals of FeCO 3 , and the inner layer is composed of compact fine FeCO 3 crystals and amorphous Cr(OH) 3 . Because of the characteristics of compactness and ionic permeating selectivity of the inner layer of the corrosion product scales, 13 Cr steel is more resistant in CO 2 corrosion environment

Heat Exchanger Tube to Tube Sheet Joints Corrosion Behavior

Directory of Open Access Journals (Sweden)

M. Iancu

2013-03-01

Full Text Available Paper presents the studies made by the authors above the tube to tube sheet fittings of heat exchanger with fixed covers from hydrofining oil reforming unit. Tube fittings are critical zones for heat exchangers failures. On a device made from material tube and tube sheet at real joints dimensions were establish axial compression force and traction force at which tube is extracted from expanded joint. Were used two shapes joints with two types of fittings surfaces, one with smooth hole of tube sheet and other in which on boring surface we made a groove. From extracted expanded tube zones were made samples for corrosion tests in order to establish the corrosion rate, corrosion potential and corrosion current in working mediums such as hydrofining oil and industrial water at different temperatures. The corrosion rate values and the temperature influence are important to evaluate joints durability and also the results obtained shows that the boring tube sheet shape with a groove on hole tube shape presents a better corrosion behavior then the shape with smooth hole tube sheet.

Tube sheet design for PFBR steam generator

International Nuclear Information System (INIS)

Chellapandi, P.; Chetal, S.C.; Bhoje, S.B.

1991-01-01

Top and bottom tube sheets of PFBR Steam Generators have been analysed with 3D and axisymmetric models using CASTEM Programs. Analysis indicates that the effects of piping reactions at the inlet/outlet nozzles on the primary stresses in the tube sheets are negligible and the asymmetricity of the deformation pattern introduced in the tube sheet by the presence of inlet/outlet and manhole nozzles is insignificant. The minimum tube sheet thicknesses for evaporator and reheater are 135 mm and 75 mm respectively. Further analysis has indicated the minimum fillet radius at the junction of tube sheet and dished end should be 20 mm. Simplified methodology has been developed to arrive at the number of thermal baffles required to protect the tube sheet against fatigue damage due to thermal transient. This method has been applied to PFBR steam generators to determine the required number of thermal baffles. For protecting the bottom tube sheet of evaporator against the thermal shock due to feed water and secondary pump trip, one thermal shield is found to be sufficient. Further analysis is required to decide upon the actual number to take care of the severe thermal transient, following the event of sudden dumping of water/steam, immediately after the sodium-water reaction. (author)

Safer operating conditions and optimal scaling-up process for cyclohexanone peroxide reaction

International Nuclear Information System (INIS)

Zang, Na; Qian, Xin-Ming; Liu, Zhen-Yi; Shu, Chi-Min

2015-01-01

Highlights: • Thermal hazard of cyclohexanone peroxide reaction was measured by experimental techniques. • Levenberg–Marquardt algorithm was adopted to evaluate kinetic parameters. • Safer operating conditions at laboratory scale were acquired by BDs and TDs. • The verified safer operating conditions were used to obtain the optimal scale-up parameters applied in industrial plants. - Abstract: The cyclohexanone peroxide reaction process, one of the eighteen hazardous chemical processes identified in China, is performed in indirectly cooled semibatch reactors. The peroxide reaction is added to a mixture of hydrogen peroxide and nitric acid, which form heterogeneous liquid–liquid systems. A simple and general procedure for building boundary and temperature diagrams of peroxide process is given here to account for the overall kinetic expressions. Such a procedure has been validated by comparison with experimental data. Thermally safer operating parameters were obtained at laboratory scale, and the scaled-up procedure was performed to give the minimum dosing time in an industrial plant, which is in favor of maximizing industrial reactor productivity. The results are of great significance for governing the peroxide reaction process apart from the thermal runaway region. It also greatly aids in determining optimization on operating parameters in industrial plants.

OPAL jet chamber full scale prototype

Energy Technology Data Exchange (ETDEWEB)

Fischer, H M; Hauschild, M; Hartmann, H; Hegerath, A; Boerner, H; Burckhart, H J; Dittmar, M; Hammarstreom, R; Heuer, R D; Mazzone, L

1986-05-22

The concept of a jet chamber for the central detector of OPAL has been tested with a full scale prototype. The design of this prototype, its mechanical and electrical structure and its support system for high voltage, gas, laser calibration and readout are described. The operating experience gathered since the summer of 1984 and the chamber performance as measured by its spatial resolution and ability to identify particles are also given.

NEI You Tube Videos: Amblyopia

Medline Plus

Full Text Available ... YouTube Videos » NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: ...

Full-Scale Mark II CRT Program data report, 1

International Nuclear Information System (INIS)

Namatame, Ken; Kukita, Yutaka; Yamamoto, Nobuo; Shiba, Masayoshi

1979-12-01

The Full-Scale Mark II CRT (Containment Response Test) Program was initiated in April 1976 to provide a full-scale data basis for the evaluation of the pressure suppression pool hydrodynamic loads associated with a hypothetical LOCA in a BWR Mark II Containment. The test facility, completed in March 1979, is 1/18 in volume of a typical 1100 MWe Mark II, and has a wetwell which is a full-scale replica of one 20 0 -sector of that of the reference Mark II. The present report documents experimental data from TEST 0002, a medium size (100 mm) water blowdown test, performed by Hitachi Ltd. for JAERI as the second of the four shakedown tests. Test data is provided for the vessel depressurization, the pressure and temperature responses in the test containment, and especially for the chugging phenomena associated with low flux steam condensation in the pool. (author)

Pervious concrete fill in Pearl-Chain Bridges: Using small-scale results in full-scale implementation

DEFF Research Database (Denmark)

Lund, Mia Schou Møller; Hansen, Kurt Kielsgaard; Truelsen, R.

2016-01-01

distribution and strength properties is determined for 800 mm high blocks cast in different numbers of layers, and (2) full-scale implementation in a 26 m long Pearl-Chain Bridge. With a layer thickness of 27 cm, the small-scale tests indicated homogenous results; however, for the full-scale implementation......Pearl-Chain Bridge technology is a new prefabricated arch solution for highway bridges. This study investigates the feasibility of pervious concrete as a filling material in Pearl-Chain Bridges. The study is divided into two steps: (1) small-scale tests where the variation in vertical void...

Development of a multi-scale simulation model of tube hydroforming for superconducting RF cavities

Energy Technology Data Exchange (ETDEWEB)

Kim, H.S. [Department of Materials Science and Engineering, The Ohio State University, Columbus, OH (United States); Sumption, M.D., E-mail: sumption.3@osu.edu [Department of Materials Science and Engineering, The Ohio State University, Columbus, OH (United States); Bong, H.J. [Department of Materials Science and Engineering, The Ohio State University, Columbus, OH (United States); Lim, H. [Sandia National Laboratories, Albuquerque, NM (United States); Collings, E.W. [Department of Materials Science and Engineering, The Ohio State University, Columbus, OH (United States)

2017-01-02

This work focuses on finite element modeling of the hydroforming process for niobium tubes intended for use in superconducting radio frequency (SRF) cavities. The hydroforming of tubular samples into SRF-relevant shapes involves the complex geometries and loading conditions which develop during the deformation, as well as anisotropic materials properties. Numerical description of the process entails relatively complex numerical simulations. A crystal plasticity (CP) model was constructed that included the evolution of crystallographic orientation during deformation as well as the anisotropy of tubes in all directions and loading conditions. In this work we demonstrate a multi-scale simulation approach which uses both microscopic CP and macroscopic continuum models. In this approach a CP model (developed and implemented into ABAQUS using UMAT) was used for determining the flow stress curve only under bi-axial loading in order to reduce the computing time. The texture of the materials obtained using orientation imaging microscopy (OIM) and tensile test data were inputs for this model. Continuum FE analysis of tube hydroforming using the obtained constitutive equation from the CP modeling was then performed and compared to the results of hydraulic bulge testing. The results show that high quality predictions of the deformation under hydroforming of Nb tubes can be obtained using CP-FEM based on their known texture and the results of tensile tests. The importance of the CP-FEM based approach is that it reduces the need for hydraulic bulge testing, using a relatively simple computational approach.

Development of a multi-scale simulation model of tube hydroforming for superconducting RF cavities

International Nuclear Information System (INIS)

Kim, H.S.; Sumption, M.D.; Bong, H.J.; Lim, H.; Collings, E.W.

2017-01-01

This work focuses on finite element modeling of the hydroforming process for niobium tubes intended for use in superconducting radio frequency (SRF) cavities. The hydroforming of tubular samples into SRF-relevant shapes involves the complex geometries and loading conditions which develop during the deformation, as well as anisotropic materials properties. Numerical description of the process entails relatively complex numerical simulations. A crystal plasticity (CP) model was constructed that included the evolution of crystallographic orientation during deformation as well as the anisotropy of tubes in all directions and loading conditions. In this work we demonstrate a multi-scale simulation approach which uses both microscopic CP and macroscopic continuum models. In this approach a CP model (developed and implemented into ABAQUS using UMAT) was used for determining the flow stress curve only under bi-axial loading in order to reduce the computing time. The texture of the materials obtained using orientation imaging microscopy (OIM) and tensile test data were inputs for this model. Continuum FE analysis of tube hydroforming using the obtained constitutive equation from the CP modeling was then performed and compared to the results of hydraulic bulge testing. The results show that high quality predictions of the deformation under hydroforming of Nb tubes can be obtained using CP-FEM based on their known texture and the results of tensile tests. The importance of the CP-FEM based approach is that it reduces the need for hydraulic bulge testing, using a relatively simple computational approach.

Evaluation of sludge pile formation in a U-tube steam generator using a scale model

International Nuclear Information System (INIS)

Padmanabhan, M.; LeClair, M.L.; Chandra, S.; Grondahl, E.E.

1989-01-01

An experimental study was conducted to investigate sludge deposition in steam generators using a semicircular model to a geometric scale of 1:3 simulating the bottom region of a U-Tube steam generator. The vertical and horizontal velocity distributions and turbulence intensities at different elevations in the bottom region were measured using a Laser Doppler Anemometry (LDA) system. The sludge deposition tests were conducted using a sludge material selected after several trial tests with different materials. The deposition patterns showed good agreement with prototype sludge patterns, available from field data. A good correlation of the sludge deposition patterns with the measured flow patterns was established. Deposition of sludge was found to be initiated within the wakes behind the tubes. (orig./DG)

Scale-up of organic reactions in ball mills: process intensification with regard to energy efficiency and economy of scale.

Science.gov (United States)

Stolle, Achim; Schmidt, Robert; Jacob, Katharina

2014-01-01

The scale-up of the Knoevenagel-condensation between vanillin and barbituric acid carried out in planetary ball mills is investigated from an engineering perspective. Generally, the reaction proceeded in the solid state without intermediate melting and afforded selectively only one product. The reaction has been used as a model to analyze the influence and relationship of different parameters related to operation in planetary ball mills. From the viewpoint of technological parameters the milling ball diameter, dMB, the filling degree with respect to the milling balls' packing, ΦMB,packing, and the filling degree of the substrates with respect to the void volume of the milling balls' packing, ΦGS, have been investigated at different reaction scales. It was found that milling balls with small dMB lead to higher yields within shorter reaction time, treaction, or lower rotation frequency, rpm. Thus, the lower limit is set considering the technology which is available for the separation of the milling balls from the product after the reaction. Regarding ΦMB,packing, results indicate that the optimal value is roughly 50% of the total milling beakers' volume, VB,total, independent of the reaction scale or reaction conditions. Thus, 30% of VB,total are taken by the milling balls. Increase of the initial batch sizes changes ΦGS significantly. However, within the investigated parameter range no negative influence on the yield was observed. Up to 50% of VB,total can be taken over by the substrates in addition to 30% for the total milling ball volume. Scale-up factors of 15 and 11 were realized considering the amount of substrates and the reactor volume, respectively. Beside technological parameters, variables which influence the process itself, treaction and rpm, were investigated also. Variation of those allowed to fine-tune the reaction conditions in order to maximize the yield and minimize the energy intensity.

Fire-Side Corrosion: A Case Study of Failed Tubes of a Fossil Fuel Boiler

Directory of Open Access Journals (Sweden)

Majid Asnavandi

2017-01-01

Full Text Available The failures of superheater and reheater boiler tubes operating in a power plant utilizing natural gas or mazut as a fuel have been analysed and the fire-side corrosion has been suggested as the main reason for the failure in boiler tubes. The tubes have been provided by a fossil fuel power plant in Iran and optical and electron microscopy investigations have been performed on the tubes as well as the corrosion products on their surfaces. The results showed that the thickness of the failed tubes is not uniform which suggests that fire-side corrosion has happened on the tubes. Fire-side corrosion is caused by the reaction of combustion products with oxide layers on the tube surface resulting in metal loss and consequently tubes fracture. However, the tubes corrosion behaviour did not follow the conventional models of the fire-side corrosion. Given that, using the corrosion monitoring techniques for these boiler tubes seems essential. As a result, the thickness of the boiler tubes in different parts of the boiler has been recorded and critical points are selected accordingly. Such critical points are selected for installation of corrosion monitoring probes.

Monitoring of full scale tensegrity skeletons under temperature change

OpenAIRE

KAWAGUCHI, Ken'ichi; OHYA, Shunji

2009-01-01

p. 224-231 Strain change in the members of full-scale tensegrity skeletons has been monitored for eight years. The one-day data of one of the tensegrity frame on the hottest and the coldest day in the record are reported and discussed. Kawaguchi, K.; Ohya, S. (2009). Monitoring of full scale tensegrity skeletons under temperature change. Symposium of the International Association for Shell and Spatial Structures. Editorial Universitat Politècnica de València. http://hdl.handle.net/10...

A shock tube and laser absorption study of ignition delay times and OH reaction rates of ketones: 2-Butanone and 3-buten-2-one

KAUST Repository

Badra, Jihad; Elwardani, Ahmed Elsaid; Khaled, Fathi; Vasu, Subith S.; Farooq, Aamir

2014-01-01

Ketones are potential biofuel candidates and are also formed as intermediate products during the oxidation of large hydrocarbons or oxygenated fuels, such as alcohols and esters. This paper presents shock tube ignition delay times and OH reaction

A study on the reaction of Zircaloy-4 tube with hydrogen/steam mixture

Science.gov (United States)

Lee, Ji-Min; Kook, Dong-Hak; Cho, Il-Je; Kim, Yong-Soo

2017-08-01

In order to fundamentally understand the secondary hydriding mechanism of zirconium alloy cladding, the reaction of commercial Zircaloy-4 tubes with hydrogen and steam mixture was studied using a thermo-gravimetric analyser with two variables, H2/H2O ratio and temperature. Phenomenological analysis revealed that in the steam starvation condition, i.e., when the H2/H2O ratio is greater than 104, hydriding is the dominant reaction and the weight gain increases linearly after a short incubation time. On the other hand, when the gas ratio is 5 × 102 or 103, both hydriding and oxidation reactions take place simultaneously, leading to three distinct regimes: primary hydriding, enhanced oxidation, and massive hydriding. Microstructural changes of oxide demonstrate that when the weight gain exceeds a certain critical value, massive hydriding takes place due to the significant localized crack development within the oxide, which possibly simulates the secondary hydriding failure in a defective fuel operation. This study reveals that the steam starvation condition above the critical H2/H2O ratio is only a necessary condition for the secondary hydriding failure and, as a sufficient condition, oxide needs to grow sufficiently to reach the critical thickness that produces substantial crack development. In other words, in a real defective fuel operation incident, the secondary failure is initiated only when both steam starvation and oxide degradation conditions are simultaneously met. Therefore, it is concluded that the indispensable time for the critical oxide growth primarily determines the triggering time of massive hydriding failure.

Comparison between full- and small-scale sensory assessments of air quality

DEFF Research Database (Denmark)

Wargocki, Pawel; Sabikova, J.; Lagercrantz, Love Per

2002-01-01

Thirty-nine untrained subjects made small- and full-scale evaluations of the acceptability of the quality of air at 22 deg.C and 40% RH, polluted by either carpet, felt floor covering, painted gypsum board, linoleum or chipboard. Small-scale evaluations were made on the air extracted from 200-L......-scale sensory ratings of acceptability of air polluted by carpet and by linoleum were systematically better than small-scale assessments, but not for the other three materials. Calculated sensory emission rates from carpet and linoleum were significantly lower in full scale than in small scale. When modelling...

Systems for animal exposure in full-scale fire tests

Science.gov (United States)

Hilado, C. J.; Cumming, H. J.; Kourtides, D. A.; Parker, J. A.

1977-01-01

Two systems for exposing animals in full-scale fire tests are described. Both systems involve the simultaneous exposure of two animal species, mice and rats, in modular units; determination of mortality, morbidity, and behavioral response; and analysis of the blood for carboxyhemoglobin. The systems described represent two of many possible options for obtaining bioassay data from full-scale fire tests. In situations where the temperatures to which the test animals are exposed can not be controlled, analytical techniques may be more appropriate than bioassay techniques.

Domestic Wastewater Reuse in Concrete Using Bench-Scale Testing and Full-Scale Implementation

Directory of Open Access Journals (Sweden)

Ayoup M. Ghrair

2016-08-01

Full Text Available Demand for fresh water by the construction sector is expected to increase due to the high increase in the growth of construction activities in Jordan. This study aims to evaluate the potential of scale-up of the application of treated domestic wastewater in concrete from bench-scale to a full-scale. On the lab scale, concrete and mortar mixes using Primary and Secondary Treated Wastewater (PTW, STW and Distilled Water (DW were cast and tested after various curing ages (7, 28, 120, and 200 days. Based on wastewater quality, according to IS 456-2000, the STW is suitable for mortar and concrete production. Mortar made with STW at curing time up to 200 days has no significant negative effect on the mortar’s compressive strength. Conversely, the PTW exceeded the maximum permissible limits of total organic content and E coli. for concrete mixing-water. Using PTW results, a significant increase in the initial setting time of up to 16.7% and a decrease in the concrete workability are observed. In addition, using PTW as mixing water led to a significant reduction in the compressive strength up to 19.6%. The results that came out from scaling up to real production operation of ready-mix concrete were in harmony with the lab-scale results.

Full-scale aicraft tire pressure tests

OpenAIRE

FABRE, C; BALAY, Jean Maurice; LERAT, P; MAZARS, A

2009-01-01

This paper describes an outdoor full-scale test planned to improve experimental and theoretical knowledge related to the effects of aircraft internal tire inflation pressure on the behavior and damage of flexible pavement. Since modern aircraft can have tire pressures greater than 15 bar, the tests focus on pressures from 15 to 17.5 bar. The experimental pavement located on the Toulouse-Blagnac airport in France will include up to seven al different test sections, representative of current ai...

Full-Scale Hollow Fiber Spacesuit Water Membrane Evaporator Prototype Development and Testing for Advanced Spacesuits

Science.gov (United States)

Bue, Grant; Trevino, Luis; Tsioulos, Gus; Mitchell, Keith; Dillon, Paul; Weaver, Gregg

2009-01-01

The spacesuit water membrane evaporator (SWME) is being developed to perform the thermal control function for advanced spacesuits to take advantage of recent advances in micropore membrane technology in providing a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. Principles of a sheet membrane SWME design were demonstrated using a prototypic test article that was tested in a vacuum chamber at JSC in July 1999. The Membrana Celgard X50-215 microporous hollow fiber (HoFi) membrane was selected after recent contamination tests as the superior candidate among commercial alternatives for HoFi SWME prototype development. Although a number of design variants were considered, one that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape, was deemed best for further development. An analysis of test data showed that eight layer stacks of the HoFi sheets that had good exposure on each side of the stack would evaporate water with high efficiency. A design that has 15,000 tubes, with 18 cm of exposed tubes between headers has been built and tested that meets the size, weight, and performance requirements of the SWME. This full-scale prototype consists of 30 stacks, each of which are formed into a chevron shape and separated by spacers and organized into three sectors of ten nested stacks. Testing has been performed to show contamination resistance to the constituents expected to be found in potable water produced by the distillation processes. Other tests showed the sensitivity to surfactants.

Full-scale tests of spent-nuclear-fuel shipping systems

International Nuclear Information System (INIS)

Yoshimura, H.R.; Huerta, M.

1976-01-01

Sandia Laboratories will be conducting, for the U.S. Energy Research and Development Administration, a series of tests involving spent-nuclear-fuel shipping systems. Large shipping casks in the 20500 to 70000-kg range will be included in the following full-scale tests: (1) Runaway tractor-trailer crash into a solid concrete barrier while carrying a shipping cask. (2) High-speed locomotive grade-crossing impact with a truck carrying a shipping cask. (3) High-speed derailment, collision, and fire involving a special railcar and shipping cask. The hardware and testing procedures for each of the tests are described. The analysis conducted in advance of the tests addresses the modelling technique used and a description of the scale-model tests. Analytical modelling being done before running the full-scale tests is also described. (author)

Full-scale tornado-missile impact tests

International Nuclear Information System (INIS)

Stephenson, A.E.; Sliter, G.E.; Burdette, E.G.

1978-01-01

Full-scale poles, pipes, and rods, representing postulated tornado-borne missiles, were rocket-propelled into reinforced concrete panels with thicknesses typical of walls and roofs in the auxillary buildings of nuclear power plants. Data from the 18 tests can be used directly for structural design or for validating design and analysis techniques. The test panels, constructed with 3000-psi design strength concrete and minimum allowable reinforcement, were 12, 18 and 24 in. thick with 15 X 15-ft unsupported spans. (Auth.)

Full-scale aircraft tire pressure tests

OpenAIRE

FABRE, C; BALAY, Jean Maurice; LERAT, P; MAZARS, A

2009-01-01

This paper describes an outdoor full-scale test planned to improve experimental and theoretical knowledge related to the effects of aircraft internal tire inflation pressure on the behavior and damage of flexible pavement. Since modern aircraft can have tire pressures greater than 15 bar, the tests will focus on pressures from 15 bar to 17.5 bar. The experimental pavement located on the Toulouse-Blagnac airport in France will include up to seven al different test sections, representative of c...

NEI You Tube Videos: Amblyopia

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Confirmatory tests of full-scale condensers for SBWR

International Nuclear Information System (INIS)

Masoni, P.; Botti, S.; Fitzsimmons, G.W.

1993-01-01

A full-scale isolation condenser and a full-scale passive containment cooling condenser for the Simplified Boiling Water Reactor (SBWR) will be tested to confirm the thermal-hydraulic and structural design characteristics of these components. The condensers provide vital roles in removing heat from the reactor vessel and the containment during certain design basis events. This paper describes the condensers and the test facilities which are under construction and summarizes the test objectives, the planned instrumentation, and the conditions to be tested. The results of some pre-test performance predictions, calculated with the TRACG code are presented. The results of the testing program are expected to demonstrate that the condenser designs will provide the required heat removal capacity and will survive the design basis temperature/pressure cycles without structural damage

Two regimes of flux scaling in axially homogeneous turbulent convection in vertical tube

Science.gov (United States)

Pawar, Shashikant S.; Arakeri, Jaywant H.

2016-08-01

From experiments of axially homogeneous turbulent convection in a vertical tube using heat (Prandtl number Pr≃6 ) and brine (Pr≃600 ) we show that at sufficiently high Rayleigh numbers (Rag), the Nusselt number Nug˜(RagPr)1/2, which corresponds to the so-called ultimate regime scaling. In heat experiments below certain Rag,however,there is transition to a new regime, Nug˜(RagPr)0.3. This transition also seems to exist in earlier reported data for Pr=1 and Pr≃600 , at different Rag. However, the transition occurs at a single Grashof number, Grgc≃1.6 ×105 , and unified flux scalings for Pr≥1 , Nug/Pr˜Grg0.3, and Nug/Pr˜Grg1/2 can be given for the two regimes.

Metal diffusion from furnace tubes depends on location

International Nuclear Information System (INIS)

Albright, L.F.

1988-01-01

Studies of metal samples from an ethylene furnace on the Texas Gulf Coast, using a scanning electron microscope (SEM) and an energy dispersive X-ray analyzer (EDAX), reveal preferential diffusion of chromium, titanium, and aluminum in the coil wall to the surfaces of the tube where they form metal oxides. These elements are gradually depleted from the tube wall. Complicated surface reactions that include the formation of several metal oxides, metal sulfides, and metal-catalyzed coke also occur. Several mechanisms can be postulated as to how metal fines or compounds are formed and transferred in the coil and transfer lines exchanger (TLX) of ethylene units. These surface reactions directly or indirectly affect coke formation in the tube. Finally, creep in the coils is likely a factor in promoting corrosion. Such creep is promoted by variable temperature-time patterns to which a coil is exposed during pyrolysis, and then decoking. Periods of stress and compression occur in the coil walls. Knowledge of the diffusion and reactions that take place can result in better furnace operations and decoking procedures to extend the life of the furnace tubes. In this second installment of a four-part series, photomicrographs of four pyrolysis tube samples from the ethylene furnace indicate that significant differences existed between the outer surfaces, inner surfaces, and cross-sectional areas of the samples. The first installment of the series dealt with coke

Full-scale and time-scale heating experiments at Stripa: preliminary results. Technical project report No. 11

International Nuclear Information System (INIS)

Cook, N.G.W.; Hood, M.

1978-12-01

Two full-scale heating experiments and a time-scale heating experiment have recently been started in granite 340 meters below surface. The purpose of the full-scale heating experiments is to assess the near-field effects of thermal loading for the design of an underground repository of nuclear wastes. That of the time-scale heating experiments is to obtain field data of the interaction between heaters and its effect on the rock mass during a period of about two years, which corresponds to about twenty years of full-scale operation. Geological features of the rock around each experiment have been mapped carefully, and temperatures, stresses and displacements induced in the rock by heating have been calculated in advance of the experiments. Some 800 different measurements are recorded at frequent intervals by a computer system situated underground. These data can be compared at any time with predictions made earlier on video display units underground

NEI You Tube Videos: Amblyopia

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Full Text Available ... search for current job openings visit HHS USAJobs Home » NEI YouTube Videos » NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract ...

A hierarchical method for Bayesian inference of rate parameters from shock tube data: Application to the study of the reaction of hydroxyl with 2-methylfuran

KAUST Repository

Kim, Daesang; El Gharamti, Iman; Hantouche, Mireille; Elwardani, Ahmed Elsaid; Farooq, Aamir; Bisetti, Fabrizio; Knio, Omar

2017-01-01

We developed a novel two-step hierarchical method for the Bayesian inference of the rate parameters of a target reaction from time-resolved concentration measurements in shock tubes. The method was applied to the calibration of the parameters

Exploiting a Simple Method for the Determination of Manganese in Polyethylene Lined Tubing for Petroleum and Natural Gas Industries

Directory of Open Access Journals (Sweden)

Shao Xiaodong

2018-01-01

Full Text Available The polyethylene lined tubing is the key to enabling the industry to meet some of the energy security challenges that nations face today. It is well known that manganese is an important element in polyethylene lined tubing. In this paper, a simple spectrophotometric method was described for the determination of manganese in polyethylene lined tubing. The method was based on the oxidation-reduction reaction between ammonium persulfate and manganese(II producing manganese(VII in the presence of silver nitrate as a catalyst. The characteristic wavelength of maximum absorption of manganese(VII was obtained locating at 530 nm. Under the optimum reaction conditions the absorption value was proportional to the concentration of manganese in the range of 0.2%~1.9% (R2 = 0.9997, and the relative standard deviation was less than 3.0% (n=5. The proposed method was applied successfully to determine manganese in polyethylene lined tubing real samples.

Analysis of full scale impact into an abutment

International Nuclear Information System (INIS)

Fullard, K.; Dowler, H.J.; Soanes, T.P.T.

1985-01-01

A 60mph impact into a tunnel abutment, of a flask on a railway flatrol with following vehicles, is shown to be a much less severe event for the flask than a 9 metre drop test to IAEA regulations. This involves the use of mathematical models of the full scale event of the same type as were employed in studying the behaviour of quarter scale models. The latter were subject to actual impact testing as part of the validation process. (author)

Propeller efficiency at full scale : measurement system and mathematical model design

NARCIS (Netherlands)

Muntean, T.V.

2012-01-01

What is propeller efficiency at full scale? This question is asked equally by ship operators and by propeller and propulsion system manufacturers. The question reflects the need to measure propeller efficiency at full physical scale and during regular operation of the vessel. The question has a

The EL-4 reactor. Changing of a pressure tube on a test loop

International Nuclear Information System (INIS)

Foulquier, H.; Clara, P.

1964-01-01

Right from the beginning of the EL-4 project, the research convected with the overall design of the reactor was guided by the various technical specifications resulting from a justifiable concern about the reliability. The external and internal tubes of each layer situated in the reactor block had in particular to be interchangeable. The research alone into the dismantling of the external tube, i.e in fact the pressure tube, justified a certain number of full-scale tests on a model. The tests carried out under relevant conditions on a non-irradiated structure made it possible to define a complete ranger of of positioning and un-positioning sequences at a distance for such a pressure tube. (authors) [fr

Characterisation of detergent-insoluble membranes in pollen tubes of Nicotiana tabacum (L.

Directory of Open Access Journals (Sweden)

Alessandra Moscatelli

2015-02-01

Full Text Available Pollen tubes are the vehicle for sperm cell delivery to the embryo sac during fertilisation of Angiosperms. They provide an intriguing model for unravelling mechanisms of growing to extremes. The asymmetric distribution of lipids and proteins in the pollen tube plasma membrane modulates ion fluxes and actin dynamics and is maintained by a delicate equilibrium between exocytosis and endocytosis. The structural constraints regulating polarised secretion and asymmetric protein distribution on the plasma membrane are mostly unknown. To address this problem, we investigated whether ordered membrane microdomains, namely membrane rafts, might contribute to sperm cell delivery. Detergent insoluble membranes, rich in sterols and sphingolipids, were isolated from tobacco pollen tubes. MALDI TOF/MS analysis revealed that actin, prohibitins and proteins involved in methylation reactions and in phosphoinositide pattern regulation are specifically present in pollen tube detergent insoluble membranes. Tubulins, voltage-dependent anion channels and proteins involved in membrane trafficking and signalling were also present. This paper reports the first evidence of membrane rafts in Angiosperm pollen tubes, opening new perspectives on the coordination of signal transduction, cytoskeleton dynamics and polarised secretion.

A Full Disturbance Model for Reaction Wheels

NARCIS (Netherlands)

Le, M.P.; Ellenbroek, Marcellinus Hermannus Maria; Seiler, R; van Put, P.; Cottaar, E.J.E.

2014-01-01

Reaction wheels are rotating devices used for the attitude control of spacecraft. However, reaction wheels also generate undesired disturbances in the form of vibrations, which may have an adverse effect on the pointing accuracy and stability of spacecraft (optical) payloads. A disturbance model for

Scale-up of the Reversible Addition-Fragmentation Chain Transfer (RAFT Polymerization Using Continuous Flow Processing

Directory of Open Access Journals (Sweden)

Nenad Micic

2014-01-01

Full Text Available A controlled radical polymerization process using the Reversible Addition-Fragmentation Chain Transfer (RAFT approach was scaled up by a factor of 100 from a small laboratory scale of 5 mL to a preparative scale of 500 mL, using batch and continuous flow processing. The batch polymerizations were carried out in a series of different glass vessels, using either magnetic or overhead stirring, and different modes of heating: Microwave irradiation or conductive heating in an oil bath. The continuous process was conducted in a prototype tubular flow reactor, consisting of 6 mm ID stainless steel tubing, fitted with static mixers. Both reactor types were tested for polymerizations of the acid functional monomers acrylic acid and 2-acrylamido-2-methylpropane-1-sulfonic acid in water at 80 °C with reaction times of 30 to 40 min. By monitoring the temperature during the exothermic polymerization process, it was observed that the type and size of reactor had a significant influence on the temperature profile of the reaction.

Selected ion flow tube studies of S2+ reactions with a series of organic molecules

Science.gov (United States)

Decker, Brian K.; Adams, Nigel G.

1997-11-01

A selected ion flow tube (SIFT) has been used to study the reactions of S2+ with a series of organic molecules (as well as H2, CO, NH3, NO and NO2). These include the hydrocarbons, C2H4, C2H6, CH2CCH2, CH3CHCH2 and C3H8; alcohols and thiols, CH3OH, C2H5OH, CH3SH and C2H5SH; ethers (CH3)2O and (C2H5)2O; aldehydes and ketones, CH3CHO, C2H5CHO and (CH3)2CO; and carboxylic acids and esters, HCO2H, HCO2CH3, HCO2C2H5, CH3CO2H, CH3CO2CH3, CH3CO2C2H5, C2H5CO2H, C2H5CO2CH3 and C2H5CO2C2H5. The rate coefficients are generally close to the collisional values, with exceptions among the reactions involving the smaller molecules. Most prevalent are abstraction reactions leading to formation of the thiosulfeno radical, HS2, or its protonated form; three-body associations; and channels leading to formation of the acetyl and propionyl cations, CH3CO+ and C2H5CO+, respectively. Only in reactions involving the alkenes is cleavage of the S---S bond of S2+ observed. The isomeric molecules in the data set generally react very differently, as would be expected from reactivity controlled by the position and complexity of the functional groups. The data are discussed in terms of reaction mechanisms, thermodynamics, and implications for interstellar chemistry.

Radiation dose in hysterosalpingography: modern 100mm fluorography vs. full-scale radiography

International Nuclear Information System (INIS)

Seppaenen, S.; Lehtinen, E.; Holli, H.

1978-01-01

Radiation doses of modern 100 mm fluorography and full-scale radiography were compared experimentally and applied to hysterosalpingography. It was determined that 100 mm fluorography reduced the doses by 28 to 29 percent per exposure and 37 to 47 percent per examination compared with full-scale radiography performed with fast tungstate screens in identical conditions (70 to 80 kV, 400 mA). The dose during one minute of videofluoroscopy was equivalent to the doses produced by one exposure in full-scale filming and three to four exposures in 100 mm filming. Although electronic magnification in 100 mm fluorography increases the doses by two or threefold, these are still less than the doses in full-scale radiography

Phase III (full scale) agitated mixing test plan

International Nuclear Information System (INIS)

Ruff, D.T.

1994-01-01

Waste Receiving and Processing Facility Module 2A (WRAP 2A) is the proposed second module of the WRAP facility. This facility will provide the required treatment for contact Handled (CH) Low Level (LL) Mixed Waste (MW) to allow its permanent disposal. Solidification of a portion of this waste using a cement based grout has been selected in order to reduce the toxicity and mobility of the waste in the disposal site. Mixing of the waste with the cement paste and material handling constraints/requirements associated with the mixed material is, therefore, a key process in the overall treatment strategy. This test plan addresses Phase 3, Full Scale Testing. The objectives of these tests are to determine if there are scale-up issues associated with the mixing results obtained in Phase 1 and 2 mixing tests, verify the workability of mixtures resulting from previous formulation development efforts (Waste Immobilization Development [WID]), and provide a baseline for WRAP 2A mixing equipment design. To this end, the following objectives are of particular interest: determine geometric influence of mixing blade at full scale (i.e., size, type, and location: height/offset); determine if similar results in terms of mixing effectiveness and product quality are achievable at this scale; determine if vibration is as effective at this larger scale in fluidizing the mixture and aiding in cleaning the vessel; determine if baffles or sweeping blades are needed to aid in mixing at the larger size and for cleaning the vessel; and determine quality of the poured monolithic product and investigate exotherm and filling influences at this larger size

Shock tube experiments on nitromethane and Promotion of chemical reactions by non-thermal plasma

Energy Technology Data Exchange (ETDEWEB)

Seljeskog, Morten

2002-06-01

This dissertation was undertaken to study two different subjects both related to molecular decomposition by applying a shock tube and non-thermal plasma to decompose selected hydrocarbons. The first approach to molecular decomposition concerned thermal decomposition and oxidation of highly diluted nitromethane (NM) in a shock tube. Reflected shock tube experiments on NM decomposition, using mixtures of 0.2 to 1.5 vol% NM in nitrogen or argon were performed over the temperature range 850-1550 K and pressure range 190-900 kPa, with 46 experiments diluted in nitrogen and 44 diluted in argon. By residual error analysis of the measured decomposition profiles it was found that NM decomposition (CH{sub 3}NO{sub 2} + M {yields} CH{sub 3} + NO{sub 2} + M, where M = N{sub 2} /Ar) corresponds well to a law of first order. Arrhenius expressions corresponding to NM diluted either in N{sub 2} or in Ar were found as k{sub N2} = 10{sup 17.011} * exp(- 182.6 kJ/mole / R*T) and k{sub Ar} = 10{sup 17.574}*exp(-207 kJ/mole / R*T ) , respectively. A new reaction mechanism was then proposed, based on new experimental data for NM decomposition both in Ar and N{sub 2} and on three previously developed mechanisms. The new mechanism predicts well the decomposition of NM diluted in both N{sub 2} and Ar within the pressure and temperature range covered by the experiments. In parallel to, and following the decomposition experiments, oxidative experiments on the ignition delay times of NM/O{sub 2}/Ar mixtures were investigated over high temperature and low to high pressure ranges. These experiments were carried out with eight different mixtures of gaseous NM and oxygen diluted in argon, with pressures ranging between 44.3-600 kPa, and temperatures ranging between 842-1378 K. The oxidation experiments were divided into different categories according to the type of decomposition signals achieved. For signals with and without emission, the apparent quasi

Importance of crevices formed between tubes and tube plate for the operational behaviour of heat exchangers

International Nuclear Information System (INIS)

Achten, N.; Herbsleb, G.; Wieling, N.

1986-01-01

It must be guaranteed by construction and manufacture of heat exchangers that primary and secondary medium are completely separated from each other. When this requirement is fullfilled, the operational use of heat exchangers can be impaired by corrosion reactions within the crevice formed between tube and tube plate which may result in corrosion damage. The various techniques which are in use to connect tubes and tube plate and which are described in the present report, must be valued with respect to the tightness of the connection as well as to the formation of crevices between tubes and tube plate. Corrosion resistant copperbase alloys and stainless steels are the most important materials which are in use for the construction of heat exchangers. The mechanisms of crevice corrosion with unalloyed and low alloy carbon steels, stainless steels, and mixed connections between tube and tube plate with these materials are described in detail. Crevice corrosion may be caused also by the formation of galvanic cells between materials of differing electrochemical response. Furthermore, the concentration of aggressive media in crevices between tubes and tube plate can lead to corrosion damage of heat exchanger tubes. For the service operation of heat exchangers without any hazard of corrosion damage in crevices between tubes and tube plate, such crevices must be avoided by proper construction and manufacture. As a model for suitable measures to avoid crevices, the manufacture of steam generators for PWR's is described. (orig.) [de

Boiling heat transfer on horizontal tube bundles

International Nuclear Information System (INIS)

Anon.

1987-01-01

Nucleate boiling heat transfer characteristics for a tube in a bundle differ from that for a single tube in a pool and this difference is known as 'tube bundle effect.' There exist two bundle effects, positive and negative. The positive bundle effect enhances heat transfer due to convective flow induced by rising bubbles generated from the lower tubes, while the negative bundle effect deteriorates heat transfer due to vapor blanketing caused by accumulation of bubbles. Staggered tube bundles tested and found that the upper tubes in bundles have higher heat transfer coefficients than the lower tubes. The effects of various parameters such as pressure, tube geometry and oil contamination on heat transfer have been examined. Some workers attempted to clarify the mechanism of occurrence of 'bundle effect' by testing tube arrangements of small scale. All reported only enhancement in heat transfer but results showed the symptom of heat transfer deterioration at higher heat fluxes. As mentioned above, it has not been clarified so far even whether the 'tube bundle effect' should serve as enhancement or deterioration of heat transfer in nucleate boiling. In this study, experiments are performed in detail by using bundles of small scale, and effects of heat flux distribution, pressure and tube location are clarified. Furthermore, some consideration on the mechanisms of occurrence of 'tube bundle effect' is made and a method for prediction of heat transfer rate is proposed

Ethanol from residues - Paper tubes and textiles; Etanol ur avfall - Pappersrullar och textilier

Energy Technology Data Exchange (ETDEWEB)

Jeihanipour, Azam; Talebnia, Farid; Loren, Anders; Nordman, Roger; Taherzadeh, Mohammad

2009-06-15

The aim of this project was to investigate the possibilities to produce ethanol from waste fractions. In this project, the investigation was limited to paper tubes and textiles. Project goals were to study: (a) Is it possible to produce ethanol from the selected waste fractions? (b) Which problems could arise in the hydrolysis and fermentation, and how could these be solved? (c) What yields could be achieved in practice, expressed as kg ethanol per kg waste? Tests have been made in both laboratory scale and in pilot scale. Weak acid hydrolysis was made in laboratory scale and in pilot scale, while enzymatic hydrolysis and SSF (simultaneous saccharification and fermentation), was made in laboratory scale only. Two different acids, phosphoric acid and sulphuric acid were used. The results from the experiments show that phosphoric acid have the best effect on dissolving the crystalline cellulosic structure of the two acids tested. This results in higher glucose yields before fermentation. The tests with paper tubes resulted in ethanol yields of 20-24 % based on dry raw material. Some textiles (jeans material) resulted in yields of 30-40% based on dry raw material. The results from the experiments show that yields of 25-30 l ethanol per 100 kg paper tubes, and 35-50 l ethanol per 100 kg textiles were reached. Waste fractions that were studied in this project are available in whole Sweden, but the relative share of the wastes depends on local conditions. In Boraas, the amount of paper tubes is approximately 300 tons per year, and textiles amounts to about 17 000 tons per year. About 25 % of the textiles are considered to be available for ethanol production. Any negative effects on the ethanol production from additives could not be noted in the experiments. For example, the additive poly-vinylic alcohol, PVA, which is present in the paper tubes, does not hamper the ethanol yield in any large proportion. During the experiments with textiles, comparative fermentation tests

Pressure tube rupture in a closed tank

International Nuclear Information System (INIS)

Khater, H.A.; Hadaller, G.I.; Stern, F.

1985-06-01

A study has been prepared on the feasibility of conducting pressure tube/calandria tube rupture tests in a closed tank, simulating a scaled-down calandria vessel. The study includes: i) a review of previous work, ii) an analytical investigation of the scaling problem of the calandria vessel and relevant in-core structures, iii) selection of a method for initiating pressure tube/calandria tube rupture, iv) a set of specifications for the test assembly, v) general arrangement drawings, vi) a proposal for a test matrix, vii) a survey and evaluation of existing facilities which could provide the required high pressure, temperature and fluid inventory, and viii) a cost estimate for the detailed design and construction, instrumentation, data acquisition and reduction, testing and reporting. The study concludes that it is both technically and practically feasible to conduct pressure tube rupture tests in a closed tank

Metallurgical Analysis of Cracks Formed on Coal Fired Boiler Tube

Science.gov (United States)

Kishor, Rajat; Kyada, Tushal; Goyal, Rajesh K.; Kathayat, T. S.

2015-02-01

Metallurgical failure analysis was carried out for cracks observed on the outer surface of a boiler tube made of ASME SA 210 GR A1 grade steel. The cracks on the surface of the tube were observed after 6 months from the installation in service. A careful visual inspection, chemical analysis, hardness measurement, detailed microstructural analysis using optical and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy were carried out to ascertain the cause for failure. Visual inspection of the failed tube revealed the presence of oxide scales and ash deposits on the surface of the tube exposed to fire. Many cracks extending longitudinally were observed on the surface of the tube. Bulging of the tube was also observed. The results of chemical analysis, hardness values and optical micrographs did not exhibit any abnormality at the region of failure. However, detailed SEM with EDS analysis confirmed the presence of various oxide scales. These scales initiated corrosion at both the inner and outer surfaces of the tube. In addition, excessive hoop stress also developed at the region of failure. It is concluded that the failure of the boiler tube took place owing to the combined effect of the corrosion caused by the oxide scales as well as the excessive hoop stress.

Autonomous smart sensor network for full-scale structural health monitoring

Science.gov (United States)

Rice, Jennifer A.; Mechitov, Kirill A.; Spencer, B. F., Jr.; Agha, Gul A.

2010-04-01

The demands of aging infrastructure require effective methods for structural monitoring and maintenance. Wireless smart sensor networks offer the ability to enhance structural health monitoring (SHM) practices through the utilization of onboard computation to achieve distributed data management. Such an approach is scalable to the large number of sensor nodes required for high-fidelity modal analysis and damage detection. While smart sensor technology is not new, the number of full-scale SHM applications has been limited. This slow progress is due, in part, to the complex network management issues that arise when moving from a laboratory setting to a full-scale monitoring implementation. This paper presents flexible network management software that enables continuous and autonomous operation of wireless smart sensor networks for full-scale SHM applications. The software components combine sleep/wake cycling for enhanced power management with threshold detection for triggering network wide tasks, such as synchronized sensing or decentralized modal analysis, during periods of critical structural response.

Full scale turbine-missile casing exit tests

International Nuclear Information System (INIS)

Yoshimura, H.R.; Schamaun, J.T.; Sliter, G.E.

1979-01-01

Two full-scale tests have simulated the impact of a fragment from a failed turbine disk upon the steel casing of a low-pressure steam turbine with the objective of providing data for making more realistic assessments of turbine missile effects for nuclear power plant designers. Data were obtained on both the energy-absorbing mechanisms of the impact process and the post-impact trajectory of the fragment. (orig.)

Tube Formation in Nanoscale Materials

Directory of Open Access Journals (Sweden)

Yan Chenglin

2008-01-01

Full Text Available Abstract The formation of tubular nanostructures normally requires layered, anisotropic, or pseudo-layered crystal structures, while inorganic compounds typically do not possess such structures, inorganic nanotubes thus have been a hot topic in the past decade. In this article, we review recent research activities on nanotubes fabrication and focus on three novel synthetic strategies for generating nanotubes from inorganic materials that do not have a layered structure. Specifically, thermal oxidation method based on gas–solid reaction to porous CuO nanotubes has been successfully established, semiconductor ZnS and Nb2O5nanotubes have been prepared by employing sacrificial template strategy based on liquid–solid reaction, and an in situ template method has been developed for the preparation of ZnO taper tubes through a chemical etching reaction. We have described the nanotube formation processes and illustrated the detailed key factors during their growth. The proposed mechanisms are presented for nanotube fabrication and the important pioneering studies are discussed on the rational design and fabrication of functional materials with tubular structures. It is the intention of this contribution to provide a brief account of these research activities.

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The product formed by reaction of an alkyl or aryl cyclopentadienyl metal carbonyl .... (as also observed from the NMR tube experiments) that the solventless reaction between ... As can be seen from Figure 3, the reaction rate in the melt.

Multi-scale modeling of diffusion-controlled reactions in polymers: renormalisation of reactivity parameters.

Science.gov (United States)

Everaers, Ralf; Rosa, Angelo

2012-01-07

The quantitative description of polymeric systems requires hierarchical modeling schemes, which bridge the gap between the atomic scale, relevant to chemical or biomolecular reactions, and the macromolecular scale, where the longest relaxation modes occur. Here, we use the formalism for diffusion-controlled reactions in polymers developed by Wilemski, Fixman, and Doi to discuss the renormalisation of the reactivity parameters in polymer models with varying spatial resolution. In particular, we show that the adjustments are independent of chain length. As a consequence, it is possible to match reactions times between descriptions with different resolution for relatively short reference chains and to use the coarse-grained model to make quantitative predictions for longer chains. We illustrate our results by a detailed discussion of the classical problem of chain cyclization in the Rouse model, which offers the simplest example of a multi-scale descriptions, if we consider differently discretized Rouse models for the same physical system. Moreover, we are able to explore different combinations of compact and non-compact diffusion in the local and large-scale dynamics by varying the embedding dimension.

A hierarchical method for Bayesian inference of rate parameters from shock tube data: Application to the study of the reaction of hydroxyl with 2-methylfuran

KAUST Repository

Kim, Daesang

2017-06-22

We developed a novel two-step hierarchical method for the Bayesian inference of the rate parameters of a target reaction from time-resolved concentration measurements in shock tubes. The method was applied to the calibration of the parameters of the reaction of hydroxyl with 2-methylfuran, which is studied experimentally via absorption measurements of the OH radical\\'s concentration following shock-heating. In the first step of the approach, each shock tube experiment is treated independently to infer the posterior distribution of the rate constant and error hyper-parameter that best explains the OH signal. In the second step, these posterior distributions are sampled to calibrate the parameters appearing in the Arrhenius reaction model for the rate constant. Furthermore, the second step is modified and repeated in order to explore alternative rate constant models and to assess the effect of uncertainties in the reflected shock\\'s temperature. Comparisons of the estimates obtained via the proposed methodology against the common least squares approach are presented. The relative merits of the novel Bayesian framework are highlighted, especially with respect to the opportunity to utilize the posterior distributions of the parameters in future uncertainty quantification studies.

The latest full-scale PWR simulator in Japan

International Nuclear Information System (INIS)

Nishimuru, Y.; Tagi, H.; Nakabayashi, T.

2004-01-01

The latest MHI Full-scale Simulator has an excellent system configuration, in both flexibility and extendability, and has highly sophisticated performance in PWR simulation by the adoption of CANAC-II and PRETTY codes. It also has an instructive character to display the plant's internal status, such as RCS condition, through animation. Further, the simulation has been verified to meet a functional examination at model plant, and with a scale model test result in a two-phase flow event, after evaluation for its accuracy. Thus, the Simulator can be devoted to a sophisticated and broad training course on PWR operation. (author)

An Investigation of Tube Wastage Caused by Small Leaks of Water in Sodium-Heated Steam Generators

Energy Technology Data Exchange (ETDEWEB)

Muenchow, H. O.; Chase, W. L. [Atomic Power Development Associates, Inc., Detroit, MI (United States)

1967-06-15

Examination of the results from a sodium-water reaction that occurred in a steam generator in the Enrico Fermi Plant revealed a generalized corrosion in the area of the reaction, producing failure of some of the adjacent tubes. The questions raised by this experience clearly indicated that the problem of small leaks causing general tube wastage should be investigated. An experimental programme was designed and divided into two categories: (1) basic studies to establish the mechanisms of wastage, including wasted surface temperature measurements, chemical attack and hot erosion; (2) studies to establish the effect of design and operating parameters on wastage occurring in a test rig that simulates the dynamics of a commercial steam generator. A small test rig supporting a 4-ft-high reaction vessel containing 5 gal of sodium was constructed. Wasted surface temperatures measured in this rig using thermocouples as the target for the sodium - water reaction have indicated temperatures in excess of 2200 Degree-Sign F. Corrosion studies, using the reaction products NaOH and Na{sub 2}O, have shown severe attack on 24 Cr-1 Mo steel tabs in 1 h under an argon atmosphere from 2200 Degree-Sign F to 2400 Degree-Sign F. Evidence indicates that corrosion is (1) minimal in the gas space above the reaction products, (2) extremely severe at the gas-liquid interface, and (3) less severe in the molten reaction products. A 101-ft-high support structure was constructed to house a test rig designed to simulate the conditions in a commercial sodium-heated steam generator. The test rig circulates 5700 lb of sodium at 400 gal/min through a 16-ft-high reaction vessel. Tests conducted in this rig have shown that the circulating water coil, which served as the target tube during the sodium-water reaction, was wasted to the point of rupturing, causing a large secondary reaction and additional damage to surrounding material. The temperature recorder went off scale at 2200 Degree-Sign F

Feedwater heater tube-to-tubesheet connections

International Nuclear Information System (INIS)

Yokell, S.

1993-01-01

This paper discusses some practical aspects of expanded, welded, and welded-and-expanded feedwater heater tube-to-tubesheet joints. It outlines elastic-plastic tube expanding theory. It examines uniform-pressure-expanded tube joint strength and correlating roller-expanded joint strength with wall reduction and rolling torque. For materials subject to stress-corrosion cracking (SCC), it recommends heat treating tube ends before expanding. For materials subject to fatigue and tube-end cracking, it advocates two-stage expanding: (1) expanding enough to create firm tube-hole contact over the full tubesheet thickness; and (2) re-expanding at full pressure or torque. The paper emphasizes the desirability of segregating heats of tubing, mapping the tube-heat locations and making the heat map a permanent part of the heater maintenance file. It recommends when to provide TEMA/HEI Power Plant Standard annular grooves for roller-expanding and provides an equation for determining optimum groove width for uniform-pressure expanding. The paper also reviews welding requirements for welds of tubes to tubesheets. The review covers front-face welding before and after expanding and the reasons for welding first. It outlines current thinking about definitions of strength- and seal-welds of front-face welded joint in terms of their functions and load-carrying abilities. It presents a proposal for determining the required size of strength welds for use in Section VIII of the ASME Boiler and Pressure Vessel Code (the Code). It shows why welded-and-expanded feedwater heater tube-to-tubesheet joints should be full-strength and full-depth expanded. It makes recommendations for pressure- and leak-testing. This work also proposes the industry consider butt welding the tubes to the steam-side face of the tubesheet as a regular method of tube joining. The results of a survey of manufacturers practices are appended. 30 refs., 14 figs

The thin-wall tube drift chamber operating in vacuum (prototype)

Science.gov (United States)

Alexeev, G. D.; Glonti, L. N.; Kekelidze, V. D.; Malyshev, V. L.; Piskun, A. A.; Potrbenikov, Yu. K.; Rodionov, V. K.; Samsonov, V. A.; Tokmenin, V. V.; Shkarovskiy, S. N.

2013-08-01

The goal of this work was to design drift tubes and a chamber operating in vacuum, and to develop technologies for tubes independent assembly and mounting in the chamber. These design and technology were tested on the prototype. The main features of the chamber are the following: the drift tubes are made of flexible mylar film (wall thickness 36 μm, diameter 9.80 mm, length 2160 mm) using ultrasonic welding along the generatrix; the welding device and methods were developed at JINR. Drift tubes with end plugs, anode wires and spacers were completely assembled outside the chamber. "Self-centering" spacers and bushes were used for precise setting of the anode wires and tubes. The assembled tubes were sealed with O-rings in their seats in the chamber which simplified the chamber assembling. Moreover the tube assembly and the chamber manufacture can be performed independently and in parallel; this sufficiently reduces the total time of chamber manufacture and assembling, its cost and allows tubes to be tested outside the chamber. The technology of independent tube assembling is suitable for a chamber of any shape but a round chamber is preferable for operation in vacuum. Single channel amplifier-discriminator boards which are more stable against cross talks were used for testing the tubes. Independently assembled tubes were mounted into the chamber prototype and its performance characteristic measured under the vacuum conditions. The results showed that both the structure and the tubes themselves normally operate. They are suitable for making a full-scale drift chamber for vacuum.

The thin-wall tube drift chamber operating in vacuum (prototype)

International Nuclear Information System (INIS)

Alexeev, G.D.; Glonti, L.N.; Kekelidze, V.D.; Malyshev, V.L.; Piskun, A.A.; Potrbenikov, Yu.K.; Rodionov, V.K.; Samsonov, V.A.; Tokmenin, V.V.; Shkarovskiy, S.N.

2013-01-01

The goal of this work was to design drift tubes and a chamber operating in vacuum, and to develop technologies for tubes independent assembly and mounting in the chamber. These design and technology were tested on the prototype. The main features of the chamber are the following: the drift tubes are made of flexible mylar film (wall thickness 36 μm, diameter 9.80 mm, length 2160 mm) using ultrasonic welding along the generatrix; the welding device and methods were developed at JINR. Drift tubes with end plugs, anode wires and spacers were completely assembled outside the chamber. “Self-centering” spacers and bushes were used for precise setting of the anode wires and tubes. The assembled tubes were sealed with O-rings in their seats in the chamber which simplified the chamber assembling. Moreover the tube assembly and the chamber manufacture can be performed independently and in parallel; this sufficiently reduces the total time of chamber manufacture and assembling, its cost and allows tubes to be tested outside the chamber. The technology of independent tube assembling is suitable for a chamber of any shape but a round chamber is preferable for operation in vacuum. Single channel amplifier-discriminator boards which are more stable against cross talks were used for testing the tubes. Independently assembled tubes were mounted into the chamber prototype and its performance characteristic measured under the vacuum conditions. The results showed that both the structure and the tubes themselves normally operate. They are suitable for making a full-scale drift chamber for vacuum

The thin-wall tube drift chamber operating in vacuum (prototype)

Energy Technology Data Exchange (ETDEWEB)

Alexeev, G.D. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Glonti, L.N., E-mail: glonti@sunse.jinr.ru [Joint Institute for Nuclear Research, Dubna (Russian Federation); Kekelidze, V.D.; Malyshev, V.L.; Piskun, A.A.; Potrbenikov, Yu.K.; Rodionov, V.K.; Samsonov, V.A.; Tokmenin, V.V.; Shkarovskiy, S.N. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

2013-08-01

The goal of this work was to design drift tubes and a chamber operating in vacuum, and to develop technologies for tubes independent assembly and mounting in the chamber. These design and technology were tested on the prototype. The main features of the chamber are the following: the drift tubes are made of flexible mylar film (wall thickness 36 μm, diameter 9.80 mm, length 2160 mm) using ultrasonic welding along the generatrix; the welding device and methods were developed at JINR. Drift tubes with end plugs, anode wires and spacers were completely assembled outside the chamber. “Self-centering” spacers and bushes were used for precise setting of the anode wires and tubes. The assembled tubes were sealed with O-rings in their seats in the chamber which simplified the chamber assembling. Moreover the tube assembly and the chamber manufacture can be performed independently and in parallel; this sufficiently reduces the total time of chamber manufacture and assembling, its cost and allows tubes to be tested outside the chamber. The technology of independent tube assembling is suitable for a chamber of any shape but a round chamber is preferable for operation in vacuum. Single channel amplifier-discriminator boards which are more stable against cross talks were used for testing the tubes. Independently assembled tubes were mounted into the chamber prototype and its performance characteristic measured under the vacuum conditions. The results showed that both the structure and the tubes themselves normally operate. They are suitable for making a full-scale drift chamber for vacuum.

A flow test for calibrating 177 core tubes of 1/5-scale reactor flow model for Yonggwang nuclear units 3 and 4

International Nuclear Information System (INIS)

Lee, Byung Jin; Jang, Ho Cheol; Cheong, Jong Sik; Kuh, Jung Eui

1990-01-01

A flow test was performed to find out the hydraulic characteristics of every one of 177 core tubes, representing a fuel assembly respectively, as a preparatory step of 1/5 scale reactor flow model test for Yonggwang Nuclear Units (hereafter YGN) 3 and 4. The axial hydraulic resistance of the fuel assembly was simulated in the square core tube with six orifice plates positioned along the tube length; core support structure below each fuel assembly was done in the core upstream geometry section of the test loop. For each core tube the pressure differentials across the inlet, exit orifice plate and overall tube length were measured, along with the flow rates and temperatures of the test fluid. The measured pressure drops were converted to pressure loss or flow metering coefficients. The metering coefficient of the inlet orifice plate was sensitive to the configuration and location of the upstream geometry. The hydraulic resistance of the core tubes were reasonably coincided with a target value and consistent. The polynomial curve fits of the calibrated coefficients for the 177 core tubes were obtained with reasonable data scatters

Production and quality control of fuel cladding tubes for LWRs

International Nuclear Information System (INIS)

Matsuda, Katsuhiko; Hagi, Shigeki; Anada, Hiroyuki; Abe, Hideaki; Hyodo, Shigetoshi

1994-01-01

This paper reviews the recent fabrication technology and corrosion resistance study of fuel cladding tubes for LWRs conducted by Sumitomo Metal Industries Ltd. started the research on zircaloy in 1957. In 1980, the factory exclusively for the production of cladding tubes was founded, and the mass production system on full scale was established. Thereafter, the various improvement of the production technology, the development of new products, and the heightening of the performance mainly on the corrosion resistance have been tested and studied. Recently, the works in the production processes were almost automated, and the installation of the production lines advanced, and the stabilization of product quality and the rationalization of costs are promoted. Moreover, the development of the zircaloy cladding tubes having high corrosion resistance has been advanced to cope with the long term cycle operation of LWRs hereafter. The features of zircaloy cladding tubes, the manufacturing processes, the improvement of the manufacturing technology, the improvement of the corrosion resistance and so on are reported. (K.I.)

Sealed ion accelerator tubes (survey)

International Nuclear Information System (INIS)

Voitsik, L.R.

1985-01-01

The first publications on developing commercial models of small-scale sealed accelerator tubes in which neutrons are generated appeared in the foreign press in 1954 to 1957; they were very brief and were advertising-oriented. The tubes were designed for neutron logging of oil wells instead of ampule neutron sources (Po + Be, Ra + Be). Later, instruments of this type began to be called neutron tubes from the resulting neutron radiation that they gave off. In Soviet Union a neutron tube was developed in 1958 in connection with the development of the pulsed neutron-neutron method of studying the geological profile of oil wells. At that time the tube developed was intended, in the view of its inventors, to replace standard isotope sources with constant neutron yield. A fairly detailed survey of neutron tubes was made in the studies. 8 refs., 8 figs

Theoretical and Shock Tube Study of the Rate Constants for Hydrogen Abstraction Reactions of Ethyl Formate

KAUST Repository

Wu, Junjun; Khaled, Fathi; Ning, Hongbo; Ma, Liuhao; Farooq, Aamir; Ren, Wei

2017-01-01

We report a systematic chemical kinetics study of the H-atom abstractions from ethyl formate (EF) by H, O(3P), CH3, OH, and HO2 radicals. The geometry optimization and frequency calculation of all the species were conducted using the M06 method and the cc-pVTZ basis set. The one-dimensional hindered rotor treatment of the reactants and transition states and the intrinsic reaction coordinate analysis were also performed at the M06/cc-pVTZ level of theory. The relative electronic energies were calculated at the CCSD(T)/cc-pVXZ (where X = D, T) level of theory and further extrapolated to the complete basis set limit. Rate constants for the tittle reactions were calculated over the temperature range of 500‒2500 K by the transition state theory (TST) in conjunction with asymmetric Eckart tunneling effect. In addition, the rate constants of H-abstraction by hydroxyl radical were measured in shock tube experiments at 900‒1321 K and 1.4‒2.0 atm. Our theoretical rate constants of OH + EF → Products agree well with the experimental results within 15% over the experimental temperature range of 900‒1321 K. Branching ratios for the five types of H-abstraction reactions were also determined from their individual site-specific rate constants.

Theoretical and Shock Tube Study of the Rate Constants for Hydrogen Abstraction Reactions of Ethyl Formate

KAUST Repository

Wu, Junjun

2017-08-03

We report a systematic chemical kinetics study of the H-atom abstractions from ethyl formate (EF) by H, O(3P), CH3, OH, and HO2 radicals. The geometry optimization and frequency calculation of all the species were conducted using the M06 method and the cc-pVTZ basis set. The one-dimensional hindered rotor treatment of the reactants and transition states and the intrinsic reaction coordinate analysis were also performed at the M06/cc-pVTZ level of theory. The relative electronic energies were calculated at the CCSD(T)/cc-pVXZ (where X = D, T) level of theory and further extrapolated to the complete basis set limit. Rate constants for the tittle reactions were calculated over the temperature range of 500‒2500 K by the transition state theory (TST) in conjunction with asymmetric Eckart tunneling effect. In addition, the rate constants of H-abstraction by hydroxyl radical were measured in shock tube experiments at 900‒1321 K and 1.4‒2.0 atm. Our theoretical rate constants of OH + EF → Products agree well with the experimental results within 15% over the experimental temperature range of 900‒1321 K. Branching ratios for the five types of H-abstraction reactions were also determined from their individual site-specific rate constants.

Dish/Stirling Hybrid-Receiver Sub-Scale Tests and Full-Scale Design

International Nuclear Information System (INIS)

Andraka, Charles; Bohn, Mark S.; Corey, John; Mehos, Mark; Moreno, James; Rawlinson, Scott

1999-01-01

We have designed and tested a prototype dish/Stirling hybrid-receiver combustion system. The system consists of a pre-mixed natural-gas burner heating a pin-finned sodium heat pipe. The design emphasizes simplicity, low cost, and ruggedness. Our test was on a 1/6 th -scale device, with a nominal firing rate of 18kWt, a power throughput of 13kWt, and a sodium vapor temperature of 750 ampersand deg;C. The air/fuel mixture was electrically preheated to 640 ampersand deg;C to simulate recuperation. The test rig was instrumented for temperatures, pressures, flow rates, overall leak rate, and exhaust emissions. The data verify our burner and heat-transfer models. Performance and post-test examinations validate our choice of materials and fabrication methods. Based on the 1/6 th -scale results, we are designing a till-scale hybrid receiver. This is a fully-integrated system, including burner, pin-fin primary heat exchanger, recuperator (in place of the electrical pre-heater used in the prototype system), solar absorber, and sodium heat pipe. The major challenges of the design are to avoid pre-ignition, achieve robust heat-pipe performance, and attain long life of the burner matrix, recuperator, and flue-gas seals. We have used computational fluid dynamics extensively in designing to avoid pre-ignition and for designing the heat-pipe wick, and we have used individual component tests and results of the 1/6 th -scale test to optimize for long life. In this paper, we present our design philosophy and basic details of our design. We describe the sub-scale test rig and compare test results with predictions. Finally, we outline the evolution of our full-scale design, and present its current status

Intercostal drainage tube or intracardiac drainage tube?

Directory of Open Access Journals (Sweden)

N Anitha

2016-01-01

Full Text Available Although insertion of chest drain tubes is a common medical practice, there are risks associated with this procedure, especially when inexperienced physicians perform it. Wrong insertion of the tube has been known to cause morbidity and occasional mortality. We report a case where the left ventricle was accidentally punctured leading to near-exsanguination. This report is to highlight the need for experienced physicians to supervise the procedure and train the younger physician in the safe performance of the procedure.

Large transverse momenta in inclusive hadronic reactions and asymptotic scale invariance

International Nuclear Information System (INIS)

Miralles, F.; Sala, C.

1976-01-01

The inclusive reaction among scalar particles in considered, assuming that in the large-transverse momentum limit, scale invariance becomes important. Predictions are made of the asymptotic scale invariance for large four transverse momentum in hadron-hadron interactions, and they are compared with previous predictions. Photoproduction is also studied and the predictions that follow from different assumptions about the compositeness of hadrons are compared

Current Status on the Development of a Double Wall Tube Steam Generator

Energy Technology Data Exchange (ETDEWEB)

Nam, Ho Yun; Choi, Byoung Hae; Kim, Jong Man; Kim, Byung Ho

2007-12-15

A fast reactor, which uses sodium as a coolant, has a lot of merits as a next generation nuclear reactor. However, the possibility of a sodium-water reaction occurrence hinders the commercialization of this reactor. As one way to improve the reliability of a steam generator, a double-wall tube steam generator is being developed in GEN-4 program. In this report, the current state of the technical developments for a double-wall tube steam generator are reviewed and a future plan for the development of a double-wall tube steam generator is established. The current focuses of this research are an improvement of the heat transfer capability for a double-wall tube and the development of a proper leak detection method for the failure of a double-wall tube during a reactor operation. The ideal goal is an on-line leak detection of a double wall tube to prevent the sodium-water reaction. However, such a method is not developed as yet. An alternative method is being used to improve the reliability of a steam generator by performing a non-destructive test of a double wall tube during the refueling period of a reactor. In this method a straight double wall tube is employed to perform this test easily, but has a difficulty regarding an absorption of a thermal expansion of the used materials. If an on-line leak detection method is developed, the demerits of a straight double-wall tube are avoided by using a helical type double-wall tube, and the probability of a sodium-water reaction can be reduced to a level less than the design-based accident.

Highly Selective Continuous Flow Hydrogenation of Cinnamaldehyde to Cinnamyl Alcohol in a Pt/SiO2 Coated Tube Reactor

Directory of Open Access Journals (Sweden)

Yang Bai

2018-02-01

Full Text Available A novel continuous flow process for selective hydrogenation of α, β-unsaturated aldehyde (cinnamaldehyde, CAL to the unsaturated alcohol (cinnamyl alcohol, COL has been reported in a tube reactor coated with a Pt/SiO2 catalyst. A 90% selectivity towards the unsaturated alcohol was obtained at the aldehyde conversion of 98.8%. This is a six-fold improvement in the selectivity compared to a batch process where acetals were the main reaction products. The increased selectivity in the tube reactor was caused by the suppression of acid sites responsible for the acetal formation after a short period on stream in the continuous process. In a fixed bed reactor, it had a similar acetal suppression phenomenon but showed lower product selectivity of about 47–72% due to mass transfer limitations. A minor change in selectivity and conversion caused by product inhibition was observed during the 110 h on stream with a turnover number (TON reaching 3000 and an alcohol production throughput of 0.36 kg gPt−1 day−1 in the single tube reactor. The catalysts performance after eight reaction cycles was fully restored by calcination in air at 400 °C. The tube reactors provide an opportunity for process intensification by increasing the reaction rates by a factor of 2.5 at the reaction temperature of 150 °C compared to 90 °C with no detrimental effects on catalyst stability or product selectivity.

Wind Farm Wake Models From Full Scale Data

DEFF Research Database (Denmark)

Knudsen, Torben; Bak, Thomas

2012-01-01

This investigation is part of the EU FP7 project “Distributed Control of Large-Scale Offshore Wind Farms”. The overall goal in this project is to develop wind farm controllers giving power set points to individual turbines in the farm in order to minimise mechanical loads and optimise power. One...... on real full scale data. The modelling is based on so called effective wind speed. It is shown that there is a wake for a wind direction range of up to 20 degrees. Further, when accounting for the wind direction it is shown that the two model structures considered can both fit the experimental data...

Homoclinic tubes and chaos in perturbed sine-Gordon equation

International Nuclear Information System (INIS)

Li, Y. Charles

2004-01-01

Sine-Gordon equation under a quasi-periodic perturbation or a chaotic perturbation is studied. Existence of a homoclinic tube is proved. Established are chaos associated with the homoclinic tube, and 'chaos cascade' referring to the embeddings of smaller scale chaos in larger scale chaos

Chest tube insertion - series (image)

Science.gov (United States)

Chest tubes are inserted to drain blood, fluid, or air and allow full expansion of the lungs. The tube is placed in the pleural space. The area where the tube will be inserted is numbed (local anesthesia). The patient may also be sedated. The chest ...

EFFECTS OF PORE STRUCTURE CHANGE AND MULTI-SCALE HETEROGENEITY ON CONTAMINANT TRANSPORT AND REACTION RATE UPSCALING

Energy Technology Data Exchange (ETDEWEB)

Peters, Catherine A [Princeton University

2013-05-15

This project addressed the scaling of geochemical reactions to core and field scales, and the interrelationship between reaction rates and flow in porous media. We targeted reactive transport problems relevant to the Hanford site specifically the reaction of highly caustic, radioactive waste solutions with subsurface sediments, and the immobilization of 90Sr and 129I through mineral incorporation and passive flow blockage, respectively. We addressed the correlation of results for pore-scale fluid-soil interaction with field-scale fluid flow, with the specific goals of (i) predicting attenuation of radionuclide concentration; (ii) estimating changes in flow rates through changes of soil permeabilities; and (iii) estimating effective reaction rates. In supplemental work, we also simulated reactive transport systems relevant to geologic carbon sequestration. As a whole, this research generated a better understanding of reactive transport in porous media, and resulted in more accurate methods for reaction rate upscaling and improved prediction of permeability evolution. These scientific advancements will ultimately lead to better tools for management and remediation of DOE legacy waste problems.

INVESTIGATION OF FOULING DEPOSIT FORMATION DURING PASTEURIZATION OF CHILI SAUCE BY USING LAB-SCALE CONCENTRIC TUBE-PASTEURIZER

Directory of Open Access Journals (Sweden)

NUR ATIKA ALI

2014-06-01

Full Text Available This paper investigates the characteristics of fouling deposits obtained from chilli sauce pasteurization. A lab-scale concentric tube-pasteurizer was used to pasteurize the chilli sauce at 0.712 kg/min and 90±5°C. It was operated for 3 hours. Temperature changes were recorded during pasteurization and the data was used to plot the heat transfer profile and the fouling resistance profile. The thickness of the fouling deposit was also measured and the image was taken for every hour. The fouling deposit was collected at every hour to test its stickiness, hardness and flow behaviour. Proximate analysis was also performed and it shows that the fouling deposit from the chilli sauce is categorized as carbohydrate-based fouling deposits. Activation energy of chilli sauce is 7049.4 J.mole-1 which shows a greater effect of temperature on the viscosity. The hardness, stickiness of fouling deposit and the heat resistance increases as the chilli sauce continuously flows inside the heat exchanger.

The HyperV Full-Scale Contoured-Gap Coaxial Plasma Railgun

Science.gov (United States)

Brockington, Samuel; Case, Andrew; Messer, Sarah; Bomgardner, Richard; Elton, Raymond; Wu, Linchun; Witherspoon, F. Douglas

2009-11-01

HyperV has been developing pulsed plasma injected coaxial railguns with a contoured gap profile designed to mitigate the blowby instability. Previous work using half-scale guns has been successful in launching 150 μg plasmas at 90 km/s [1]. In order to meet the original goal of 200 μg at 200 km/s the full-scale coaxial plasma gun has been constructed, and initial testing is beginning. This new plasma gun consists of two machined aluminum electrodes and a UHMW polyethylene breech insulator. The gun is breech fed by 64 ablative polyethylene capillary discharge units identical to the half-scale gun units. Maximum accelerator energy storage has also been increased 50%. Refractory coatings may be necessary to allow full current (˜800 kA) operation. The outer electrode includes 24 small diagnostic ports for optical and magnetic probe access to the plasma inside the gun to allow direct measurement of the plasma armature dynamics. Initial test data from the full-scale coax gun will be presented along with plans for future testing. Work supported by the U.S. DOE Office of Fusion Energy Sciences.[4pt] [1] F. D. Witherspoon, A. Case, S. Messer, R. Bomgardner, M. Phillips, S. Brockington, R. Elton, ``Contoured Gap Coaxial Plasma Gun with Injected Plasma Armature'' Rev. Sci. Instr. submitted (2009)

CONCENTRIC TUBE-FOULING RIG FOR INVESTIGATION OF FOULING DEPOSIT FORMATION FROM PASTEURISER OF VISCOUS FOOD LIQUID

Directory of Open Access Journals (Sweden)

N. I. KHALID

2013-02-01

Full Text Available This paper reports the work on developing concentric tube-fouling rig, a new fouling deposit monitoring device. This device can detect and quantify the level of fouling deposit formation. It can also functioning as sampler for fouling deposit study, which can be attached at any food processing equipment. The design is initiated with conceptual design. The rig is designed with inner diameter of 7 cm and with tube length of 37 cm. A spiral insert with 34.5 cm length and with 5.4 cm diameter is fitted inside the tube to ensure the fluid flows around the tube. In this work, the rig is attached to the lab-scale concentric tube-pasteurizer to test its effectiveness and to collect a fouling sample after pasteurization of pink guava puree. Temperature changes are recorded during the pasteurization and the data is used to plot the heat transfer profile. Thickness of the fouling deposit is also measured. The trends for thickness, heat resistance profile and heat transfer profile for concentric tube-fouling rig matched the trends obtained from lab-scale concentric tube-pasteurizer very well. The findings from this work have shown a good potential of this rig however there is a limitation with spiral insert, which is discussed in this paper.

Multifractal scaling analysis of autopoisoning reactions over a rough surface

International Nuclear Information System (INIS)

Chaudhari, Ajay; Yan, Ching-Cher Sanders; Lee, S.-L.

2003-01-01

Decay type diffusion-limited reactions (DLR) over a rough surface generated by a random deposition model were performed. To study the effect of the decay profile on the reaction probability distribution (RPD), multifractal scaling analysis has been carried out. The dynamics of these autopoisoning reactions are controlled by the two parameters in the decay function, namely, the initial sticking probability (P ini ) of every site and the decay rate (m). The smaller the decay rate, the narrower is the range of α values in the α-f(α) multifractal spectrum. The results are compared with the earlier work of DLR over a surface of diffusion-limited aggregation (DLA). We also considered here the autopoisoning reactions over a smooth surface for comparing our results, which show clearly how the roughness affects the chemical reactions. The q-τ(q) multifractal curves for the smooth surface are linear whereas those for the rough surface are nonlinear. The range of α values in the case of a rough surface is wider than that of the smooth surface

Manufacturing Cost Analysis for YSZ-Based FlexCells at Pilot and Full Scale Production Scales

Energy Technology Data Exchange (ETDEWEB)

Scott Swartz; Lora Thrun; Robin Kimbrell; Kellie Chenault

2011-05-01

Significant reductions in cell costs must be achieved in order to realize the full commercial potential of megawatt-scale SOFC power systems. The FlexCell designed by NexTech Materials is a scalable SOFC technology that offers particular advantages over competitive technologies. In this updated topical report, NexTech analyzes its FlexCell design and fabrication process to establish manufacturing costs at both pilot scale (10 MW/year) and full-scale (250 MW/year) production levels and benchmarks this against estimated anode supported cell costs at the 250 MW scale. This analysis will show that even with conservative assumptions for yield, materials usage, and cell power density, a cost of $35 per kilowatt can be achieved at high volume. Through advancements in cell size and membrane thickness, NexTech has identified paths for achieving cell manufacturing costs as low as $27 per kilowatt for its FlexCell technology. Also in this report, NexTech analyzes the impact of raw material costs on cell cost, showing the significant increases that result if target raw material costs cannot be achieved at this volume.

Passive Infrared Signature Augmentation of Full-Scale Plastic Targets

National Research Council Canada - National Science Library

Gebus, Lisa M; Sanders, Jeffrey S

2002-01-01

... (IR), and radar signatures of threat systems. To address this need, a program was initiated by TMO to augment an existing full-scale, vacuum-formed plastic target with sufficient signature fidelity to adequately stress U.S...

The development and application of overheating failure model of FBR steam generator tubes. 2

International Nuclear Information System (INIS)

Miyake, Osamu; Hamada, Hirotsugu; Tanabe, Hiromi

2001-11-01

The JNC technical report 'The Development and Application of Overheating Failure Model of FBR Steam Generator Tubes' summarized the assessment method and its application for the overheating tube failure in an event of sodium-water reaction accident of fast breeder reactor's steam generators (SGs). This report describes the following items studied after the publication of the above technical report. 1. On the basis of the SWAT-3 experimental data, realistic local heating conditions (reaction zone temperature and related heat transfer conditions) for the sodium-water reaction were proposed. New correlations are cosine-shaped temperature profiles with 1,170 C maximum for the 100% and 40% Monju operating conditions, and those with 1,110 C maximum for the 10% condition. 2. For the cooling effects inside of target tubes, LWR's studies of critical heat flux (CHF) and post-CHF heat transfer correlations have been examined and considered in the assessment. The revised assessment adopts the Katto's correlation for CHF, and the Condie-Bengston IV correlation for post-CHF. 3. Other additional examination for the assessment includes treatments of the whole heating effect (other than the local reaction zone) due to the sodium-water reaction, and the temperature-dependent thermal properties of the heat transfer tube material (2.25Cr-1Mo steel). The revised overheating tube failure assessment method has been applied to the Monju SG studies. It is revealed consequently that no tube failure occurs in 100%, 40%, and 10% operating conditions when an initial leak is detected by the cover gas pressure detection system. The assessment for the SG system improved for the detection and blowdown systems shows even better safety margins against the overheating tube failure. (author)

Fabrication of seamless calandria tubes

International Nuclear Information System (INIS)

Saibaba, N.; Phanibabu, C.; Bhaskara Rao, C.V.; Kalidas, R.; Ganguly, C.

2002-01-01

Full text: Calandria tube is a large diameter, thin walled zircaloy-4 tube and is an important structural component of PHWR type of reactors. These tubes are lifetime components and remain during the full life of the reactor. Calandria tubes are classified as extremely thin walled tubes with a diameter to wall thickness ratio of around 96. Such thin walled tubes are conventionally produced by seam welded route comprising of extrusion of slabs followed by a series of hot and rolling passes, shaping into O-shape and eventual welding. An alternative and superior method of fabricating the calandria tubes, the seamless route, has been developed, which involves hot extrusion of mother blanks followed by three successive cold pilger reductions. Eccentricity correction of the extruded blanks is carried out on a special purpose grinding equipment to bring the wall thickness variation within permissible limits. Predominant wall thickness reductions are given during cold pilgering to ensure high Q-factor values. The texture in the finished tubes could be closely, controlled with an average f r value of 0.65. Pilgering parameters and tube guiding system have been specially designed to facilities rolling of thin walled tubes. Seamless calandria tubes have distinct advantages over welded tubes. In addition to the absence of weld, they are dimensionally more stable, lighter in weight and possess uniform grains with superior grain size. The cycle time from billet to finished product is substantially reduced and the product is amenable to high level of quality assurance. The most significant feature of the seamless route is its material recovery over welded route. Residual stresses measured in the tubes indicate that these are negligible and uniform along the length of the tube. In view of their superior quality, the first charge of seamless calandria tubes will be rolled into the first 500 MWe Pressurised Heavy Water Reactor at Tarapur

Evaluation of the airway of the SimMan full-scale patient simulator

DEFF Research Database (Denmark)

Hesselfeldt, R; Kristensen, M S; Rasmussen, L S

2005-01-01

SimMan is a full-scale patient simulator, capable of simulating normal and pathological airways. The performance of SimMan has never been critically evaluated.......SimMan is a full-scale patient simulator, capable of simulating normal and pathological airways. The performance of SimMan has never been critically evaluated....

Tubing cutter for tight spaces

Science.gov (United States)

Girala, A. S.

1980-01-01

Cutter requires few short swings of handle to rotate its cutting edge full 360 around tube. It will cut tubing installed in confined space that prevents free movement of conventional cutter. Cutter is snapped onto tube and held in place by spring-loaded clamp. Screw ratchet advances cutting wheel.

Replicating the microbial community and water quality performance of full-scale slow sand filters in laboratory-scale filters.

Science.gov (United States)

Haig, Sarah-Jane; Quince, Christopher; Davies, Robert L; Dorea, Caetano C; Collins, Gavin

2014-09-15

Previous laboratory-scale studies to characterise the functional microbial ecology of slow sand filters have suffered from methodological limitations that could compromise their relevance to full-scale systems. Therefore, to ascertain if laboratory-scale slow sand filters (L-SSFs) can replicate the microbial community and water quality production of industrially operated full-scale slow sand filters (I-SSFs), eight cylindrical L-SSFs were constructed and were used to treat water from the same source as the I-SSFs. Half of the L-SSFs sand beds were composed of sterilized sand (sterile) from the industrial filters and the other half with sand taken directly from the same industrial filter (non-sterile). All filters were operated for 10 weeks, with the microbial community and water quality parameters sampled and analysed weekly. To characterize the microbial community phyla-specific qPCR assays and 454 pyrosequencing of the 16S rRNA gene were used in conjunction with an array of statistical techniques. The results demonstrate that it is possible to mimic both the water quality production and the structure of the microbial community of full-scale filters in the laboratory - at all levels of taxonomic classification except OTU - thus allowing comparison of LSSF experiments with full-scale units. Further, it was found that the sand type composing the filter bed (non-sterile or sterile), the water quality produced, the age of the filters and the depth of sand samples were all significant factors in explaining observed differences in the structure of the microbial consortia. This study is the first to the authors' knowledge that demonstrates that scaled-down slow sand filters can accurately reproduce the water quality and microbial consortia of full-scale slow sand filters. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multifrequency eddy current testing of helical tubes of steam generators

International Nuclear Information System (INIS)

Pigeon, M.; David, B.

1983-06-01

In the event of a water-sodium reaction in a steam-generator of a fast breeder reactor, it is necessary to test the tubes close to the leak to evaluate the damage. In SUPERPHENIX, the tubes are about 100m long and are coiled on a dead body. This report describes the equipment and the technic to test such tubes with multifrequency eddy current technics [fr

Aerobic Sludge Granulation in a Full-Scale Sequencing Batch Reactor

Directory of Open Access Journals (Sweden)

Jun Li

2014-01-01

Full Text Available Aerobic granulation of activated sludge was successfully achieved in a full-scale sequencing batch reactor (SBR with 50,000 m3 d−1 for treating a town’s wastewater. After operation for 337 days, in this full-scale SBR, aerobic granules with an average SVI30 of 47.1 mL g−1, diameter of 0.5 mm, and settling velocity of 42 m h−1 were obtained. Compared to an anaerobic/oxic plug flow (A/O reactor and an oxidation ditch (OD being operated in this wastewater treatment plant, the sludge from full-scale SBR has more compact structure and excellent settling ability. Denaturing gradient gel electrophoresis (DGGE analysis indicated that Flavobacterium sp., uncultured beta proteobacterium, uncultured Aquabacterium sp., and uncultured Leptothrix sp. were just dominant in SBR, whereas uncultured bacteroidetes were only found in A/O and OD. Three kinds of sludge had a high content of protein in extracellular polymeric substances (EPS. X-ray fluorescence (XRF analysis revealed that metal ions and some inorganics from raw wastewater precipitated in sludge acted as core to enhance granulation. Raw wastewater characteristics had a positive effect on the granule formation, but the SBR mode operating with periodic feast-famine, shorter settling time, and no return sludge pump played a crucial role in aerobic sludge granulation.

Fluid mechanics of dynamic stall. II - Prediction of full scale characteristics

Science.gov (United States)

Ericsson, L. E.; Reding, J. P.

1988-01-01

Analytical extrapolations are made from experimental subscale dynamics to predict full scale characteristics of dynamic stall. The method proceeds by establishing analytic relationships between dynamic and static aerodynamic characteristics induced by viscous flow effects. The method is then validated by predicting dynamic test results on the basis of corresponding static test data obtained at the same subscale flow conditions, and the effect of Reynolds number on the static aerodynamic characteristics are determined from subscale to full scale flow conditions.

Bacterial Biofilms in Jones Tubes.

Science.gov (United States)

Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

Large scale sodium-water reaction tests for Monju steam generators

International Nuclear Information System (INIS)

Sato, M.; Hiroi, H.; Hori, M.

1976-01-01

To demonstrate the safe design of the steam generator system of the prototype fast reactor Monju against the postulated large leak sodium-water reaction, a large scale test facility SWAT-3 was constructed. SWAT-3 is a 1/2.5 scale model of the Monju secondary loop on the basis of the iso-velocity modeling. Two tests have been conducted in SWAT-3 since its construction. The test items using SWAT-3 are discussed, and the description of the facility and the test results are presented

Up-Scaling Geochemical Reaction Rates for Carbon Dioxide (CO2) in Deep Saline Aquifers

Energy Technology Data Exchange (ETDEWEB)

Peters, Catherine A

2013-02-28

Geochemical reactions in deep subsurface environments are complicated by the consolidated nature and mineralogical complexity of sedimentary rocks. Understanding the kinetics of these reactions is critical to our ability to make long-term predictions about subsurface processes such as pH buffering, alteration in rock structure, permeability changes, and formation of secondary precipitates. In this project, we used a combination of experiments and numerical simulation to bridge the gap between our knowledge of these reactions at the lab scale and rates that are meaningful for modeling reactive transport at core scales. The focus is on acid-driven mineral dissolution, which is specifically relevant in the context of CO2-water-rock interactions in geological sequestration of carbon dioxide. The project led to major findings in three areas. First, we modeled reactive transport in pore-network systems to investigate scaling effects in geochemical reaction rates. We found significant scaling effects when CO2 concentrations are high and reaction rates are fast. These findings indicate that the increased acidity associated with geological sequestration can generate conditions for which proper scaling tools are yet to be developed. Second, we used mathematical modeling to investigate the extent to which SO2, if co-injected with CO2, would acidify formation brines. We found that there exist realistic conditions in which the impact on brine acidity will be limited due to diffusion rate-limited SO2 dissolution from the CO2 phase, and the subsequent pH shift may also be limited by the lack of availability of oxidants to produce sulfuric acid. Third, for three Viking sandstones (Alberta sedimentary basin, Canada), we employed backscattered electron microscopy and energy dispersive X-ray spectroscopy to statistically characterize mineral contact with pore space. We determined that for reactive minerals in sedimentary consolidated rocks, abundance alone is not a good predictor of

Beating the heat! automated characterization of piezoelectric tubes for Starbugs

Science.gov (United States)

Piersiak, Rafal; Goodwin, Michael; Gilbert, James; Muller, Rolf

2014-08-01

The Australian Astronomical Observatory has extensively prototyped a new robotic positioner to allow simultaneous positioning of optical fibers at the focal plane called `Starbugs'. The Starbug devices each consist of two concentric piezoelectric tubes that `walk' the optical fiber over the focal plane to accuracy of several microns. Ongoing research has led to the development of several Starbug prototypes, but lack of performance data has hampered further progress in the design of the Starbug positioners and the support equipment required to power and control them. Furthermore, Starbugs have been selected for the TAIPAN instrument, a prototype for MANIFEST on the GMT. A need now arises to measure and characterize 100's of piezoelectric tubes before full scale production of Starbugs for TAIPAN. The manual measurements of these piezoelectric tubes are a time consuming process taking several hours. Therefore, a versatile automated system is needed to measure and characterize these tubes in the laboratory before production of Starbugs. We have solved this problem with the design of an automated LabVIEW application that significantly reduces test times to several minutes. We present the various design aspects of the automation system and provide analyses of example piezoelectric tubes for Starbugs.

Chemical kinetics studies at high temperatures using shock tubes

OpenAIRE

Rajakumar, B; Anandraj, D; Reddy, KPJ; Arunan, E

2002-01-01

Shock tube is an unique facility to create temperature gradients exceeding million degrees Kelvin per second. We have established two shock tubes for measuring the kinetic reaction rates at high temperatures with two different but complementary detection techniques. The first one is a single pulse shock tube, in which the reflected shock is used to heat the molecules. The equilibrated products are analyzed by gas chromatograph and infrared spectrometer. The second one uses laser-schlieren sys...

Large-scale photochemical reactions of nanocrystalline suspensions: a promising green chemistry method.

Science.gov (United States)

Veerman, Marcel; Resendiz, Marino J E; Garcia-Garibay, Miguel A

2006-06-08

Photochemical reactions in the solid state can be scaled up from a few milligrams to 10 grams by using colloidal suspensions of a photoactive molecular crystal prepared by the solvent shift method. Pure products are recovered by filtration, and the use of H(2)O as a suspension medium makes this method a very attractive one from a green chemistry perspective. Using the photodecarbonylation of dicumyl ketone (DCK) as a test system, we show that reaction efficiencies in colloidal suspensions rival those observed in solution. [reaction: see text

Full scale demonstration of air-purifying pavement

International Nuclear Information System (INIS)

Ballari, M.M.; Brouwers, H.J.H.

2013-01-01

Highlights: ► The results of a demonstration project for photocatalytic pavement are shown. ► The photocatalytic performance was studied in a street as well as on lab scale. ► The outdoor monitoring was performed in different seasons and weather conditions. ► The NO x concentration was in average 19% lowered by the photocatalytic street. ► Under ideal weather conditions the NO x reduction reached up to 45%. -- Abstract: Experiments concerning a full-scale demonstration of air purifying pavement in Hengelo, The Netherlands, are reported. The full width of the street was provided with concrete pavement containing TiO 2 over a length of 150 m (“DeNO x street”). Another part of the street, about 100 m, was paved with normal paving blocks (“Control street”). The outdoor monitoring was done during 26 days for a period exceeding one year, and measured parameters included traffic intensity, NO, NO 2 and ozone concentrations, temperature, relative humidity, wind speed and direction, and the visible and UV light irradiance. Prior and parallel to these field measurements, the used blocks were also measured in the lab to assess their performance. The NO x concentration was, on average, 19% (considering the whole day) and 28% (considering only afternoons) lower than the obtained values in the Control street. Under ideal weather conditions (high radiation and low relative humidity) a NO x concentration decrease of 45% could be observed

Full scale demonstration of air-purifying pavement

Energy Technology Data Exchange (ETDEWEB)

Ballari, M.M., E-mail: ballari@santafe-conicet.gov.ar [Department of the Built Environment, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Brouwers, H.J.H., E-mail: jos.brouwers@tue.nl [Department of the Built Environment, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

2013-06-15

Highlights: ► The results of a demonstration project for photocatalytic pavement are shown. ► The photocatalytic performance was studied in a street as well as on lab scale. ► The outdoor monitoring was performed in different seasons and weather conditions. ► The NO{sub x} concentration was in average 19% lowered by the photocatalytic street. ► Under ideal weather conditions the NO{sub x} reduction reached up to 45%. -- Abstract: Experiments concerning a full-scale demonstration of air purifying pavement in Hengelo, The Netherlands, are reported. The full width of the street was provided with concrete pavement containing TiO{sub 2} over a length of 150 m (“DeNO{sub x} street”). Another part of the street, about 100 m, was paved with normal paving blocks (“Control street”). The outdoor monitoring was done during 26 days for a period exceeding one year, and measured parameters included traffic intensity, NO, NO{sub 2} and ozone concentrations, temperature, relative humidity, wind speed and direction, and the visible and UV light irradiance. Prior and parallel to these field measurements, the used blocks were also measured in the lab to assess their performance. The NO{sub x} concentration was, on average, 19% (considering the whole day) and 28% (considering only afternoons) lower than the obtained values in the Control street. Under ideal weather conditions (high radiation and low relative humidity) a NO{sub x} concentration decrease of 45% could be observed.

Outline of sodium-water reaction test in case of large leak with SWAT-3 testing equipments

International Nuclear Information System (INIS)

Sato, Minoru

1978-01-01

The key component in sodium-cooled fast reactors in steam generators, and the sodium-water reaction owing to the break of heating tubes may cause serious damages in equipments and pipings. The main factor controlling this phenomenon is the rate of leak of water. When the rate of water leak is small, the propagation of heating tube breaking may occur owing to ''wastage phenomenon'', on the other hand, when the rate of water leak is large, the phenomena of explosive pressure and flow occur due to the reaction heat and a large quantity of hydrogen generated by the reaction. In PNC, the testing equipments of SWAT-2 for small water leak and SWAT-1 for large leak were constructed, and the development test has been carried out to establish the method of safety design experimentally. The synthetic test equipment for the safety of steam generators, SWAT-3, was constructed to carry out the large water leak test in the scale close to actual plants. The object of the test, the outline of the test equipment, the phenomena of pressure and flow in the water injection test, the confirmation of the occurrence of secondary breaking of adjacent heating tubes, and the disposal of reaction products are described in this paper. This test is till going on, and the final conclusion will be reported later. (Kako, I.)

Detection tube with composite carrier for detection of phosgene and diphosgene in air

Directory of Open Access Journals (Sweden)

Pitschmann Vladimír

2012-01-01

Full Text Available A new highly sensitive detection tube for measurement of concentration of phosgene and diphosgene in air has been developed. The detection is based on chemical reaction of 4-(p-nitrobenzylpyridine and N-phenylbenzylamine which with phosgene (diphosgene give characteristic red methine dye. As a carrier serves spherical granules (pellets of composite material prepared by granulation of microcrystalline cellulose with MgO. This new indication filling is stable, resistant to interferences and climatic influences. The detection limit (0.05 mg.m-3 meets the requirements for conducting hygienic checks of air quality in the workplace environment. In addition, the tube allows a prolonged and continuous monitoring of phosgene and diphosgene in air for at least 240 minutes.

CFD prediction of mixing in a steam generator mock-up: Comparison between full geometry and porous medium approaches

International Nuclear Information System (INIS)

Dehbi, A.; Badreddine, H.

2013-01-01

Highlights: • CFD is used to simulate single phase mixing in a model steam generator. • Motive of the work is to compare porous media approach with full geometry representation of tubes. • Porous media approach is found to compare favorably with full representation in steady states. - Abstract: In CFD simulations of single phase flow mixing in a steam generator (SG) during a station blackout severe accident, one is faced with the problem of representing the thousands of SG U-tubes. Typically simplifications are made to render the problem computationally tractable. In particular, one or a number of tubes are lumped in one volume that is treated as a single porous medium which replicates the pressure loss and heat transfer characteristics of the real tube. This approach significantly reduces the computational size of the problem and hence simulation time. In this work, we endeavor to investigate the adequacy of this approach by performing a series of simulations. We first validate the porous medium approach against results of the 1/7th scale Westinghouse SG-S3 test. In a second step, we make two separate simulations of flow in the PSI SG mock-up, i.e. one in which the porous medium model is used for the tube bundle, and another in which the full geometry is represented. In all simulations, the Reynolds Stress (RSM) model of turbulence is used. We show that in steady state conditions, the porous medium treatment yields results which are comparable to those of the full geometry representation (temperature distribution, recirculation ratio, hot plume spread, etc.). Hence, the porous medium approach can be extended with a good degree of confidence to model single phase mixing in the full scale SG

Full-scale mark II CRT program facility description report

International Nuclear Information System (INIS)

Namatame, Ken; Kukita, Yutaka; Ito, Hideo; Yamamoto, Nobuo; Shiba, Masayoshi

1980-03-01

Started in fiscal year 1977, the Full-Scale Mark II CRT (Containment Response Test) Program is proceeding for the period of five years. The primary objective of the CRT Program is to provide a data base for evaluation of the pressure suppression pool hydrodynamic loads associated with a postulated loss-of-coolant accident in the BWR Mark II containment system. The test facility was designed and constructed from fiscal year 1977 to 1978, and completed in March 1979. It is 1/18 in volume and has a wetwell which is a full-scale replica of one 20 0 -sector of that of a reference Mark II. This report describes design concepts, dimensions and constructions of the test facility, as well as specifications, locations and installation schemes of the measuring equipments. Results of soil structure inspection, vacuum breaker test and shaker test of the containment shell are given in the appendices. (author)

Polyethylene encapsulation full-scale technology demonstration. Final report

International Nuclear Information System (INIS)

Kalb, P.D.; Lageraaen, P.R.

1994-10-01

A full-scale integrated technology demonstration of a polyethylene encapsulation process, sponsored by the US Department of Energy (DOE) Office of Technology Development (OTD), was conducted at the Environmental ampersand Waste Technology Center at Brookhaven National Laboratory (BNL.) in September 1994. As part of the Polymer Solidification National Effort, polyethylene encapsulation has been developed and tested at BNL as an alternative solidification technology for improved, cost-effective treatment of low-level radioactive (LLW), hazardous and mixed wastes. A fully equipped production-scale system, capable of processing 900 kg/hr (2000 lb/hr), has been installed at BNL. The demonstration covered all facets of the integrated processing system including pre-treatment of aqueous wastes, precise feed metering, extrusion processing, on-line quality control monitoring, and process control

Wave propagation in spatially modulated tubes

Energy Technology Data Exchange (ETDEWEB)

Ziepke, A., E-mail: ziepke@itp.tu-berlin.de; Martens, S.; Engel, H. [Institut für Theoretische Physik, Hardenbergstraße 36, EW 7-1, Technische Universität Berlin, 10623 Berlin (Germany)

2016-09-07

We investigate wave propagation in rotationally symmetric tubes with a periodic spatial modulation of cross section. Using an asymptotic perturbation analysis, the governing quasi-two-dimensional reaction-diffusion equation can be reduced into a one-dimensional reaction-diffusion-advection equation. Assuming a weak perturbation by the advection term and using projection method, in a second step, an equation of motion for traveling waves within such tubes can be derived. Both methods predict properly the nonlinear dependence of the propagation velocity on the ratio of the modulation period of the geometry to the intrinsic width of the front, or pulse. As a main feature, we observe finite intervals of propagation failure of waves induced by the tube’s modulation and derive an analytically tractable condition for their occurrence. For the highly diffusive limit, using the Fick-Jacobs approach, we show that wave velocities within modulated tubes are governed by an effective diffusion coefficient. Furthermore, we discuss the effects of a single bottleneck on the period of pulse trains. We observe period changes by integer fractions dependent on the bottleneck width and the period of the entering pulse train.

Evaluation of a Sodium–Water Reaction Event Caused by Steam Generator Tubes Break in the Prototype Generation IV Sodium-cooled Fast Reactor

Directory of Open Access Journals (Sweden)

Sang June Ahn

2016-08-01

Full Text Available The prototype generation IV sodium-cooled fast reactor (PGSFR has been developed by the Korea Atomic Energy Research Institute. This reactor uses sodium as a reactor coolant to transfer the core heat energy to the turbine. Sodium has chemical characteristics that allow it to violently react with materials such as a water or steam. When a sodium–water reaction (SWR occurs due to leakage or breakage of steam generator tubes, high-pressure waves and corrosive reaction products are produced, which threaten the structural integrity of the components of the intermediate heat-transfer system (IHTS and the safety of the primary heat-transfer system (PHTS. In the PGSFR, SWR events are included in the design-basis event. This event should be analyzed from the viewpoint of the integrities of the IHTS and fuel rods. To evaluate the integrity of the IHTS based on the consequences of the SWR, the behaviors of the generated high-pressure waves are analyzed at the major positions of a failed IHTS loop using a sodium–water advanced analysis method-II code. The integrity of the fuel rods must be consistently maintained below the safety acceptance criteria to avoid the consequences of the SWR. The integrity of the PHTS is evaluated using the multidimensional analysis of reactor safety-liquid metal reactor code to model the whole plant.

Flow-through polymerase chain reaction inside a seamless 3D helical microreactor fabricated utilizing a silicone tube and a paraffin mold.

Science.gov (United States)

Wu, Wenming; Trinh, Kieu The Loan; Lee, Nae Yoon

2015-03-07

We introduce a new strategy for fabricating a seamless three-dimensional (3D) helical microreactor utilizing a silicone tube and a paraffin mold. With this method, various shapes and sizes of 3D helical microreactors were fabricated, and a complicated and laborious photolithographic process, or 3D printing, was eliminated. With dramatically enhanced portability at a significantly reduced fabrication cost, such a device can be considered to be the simplest microreactor, developed to date, for performing the flow-through polymerase chain reaction (PCR).

Single-tube hydroponics as a novel idea for small-scale production of crop seed in a plant incubator.

Science.gov (United States)

Kuroda, Masaharu; Ikenaga, Sachiko

2015-01-01

We present a novel protocol for small-scale production of crop seed in a plant incubator termed "Single-tube hydroponics." Our protocol minimizes the materials and methods for cultivation whereby a large number of independent plants can be cultured in a limited space. This study may aid in the improvement of crop seed components, especially in the cultivation of transgenic plants.

Kinetics of barium sulphate reaction crystallization in crystallizers with internal circulation

Directory of Open Access Journals (Sweden)

J. Koralewska

2008-06-01

Full Text Available Kinetic calculation results describing the observed nucleation and growth rates of barium sulphate crystals precipitated in an integrated reaction-crystallization process in a barium sulphate-ammonium chloride-water system are presented and analyzed. The scope of experiments included two continuous model DTM-type crystallizers (Draft Tube Magma with internal circulation of the suspension forced by a liquid jet-pump device responsible for stable and intensive enough ascending/descending flow of BaSO4 crystal magma in a mixing chamber. For comparison purposes the experimental data corresponding to a continuous DT (Draft Tube crystallizer with propeller agitator are presented and discussed. The various types of laboratory crystallizers used were fed with concentrated water solution of barium chloride (of 10 or 24 mass % and - in a stoichiometric proportion - crystalline ammonium sulphate, assuming isothermal (348 K and hydrodynamic (average residence time of suspension in a crystallizer: 900 s process conditions. The observed nucleation and growth rates of barium sulphate crystals were estimated on the basis of crystal size distributions (CSDs using convenient calculation scheme derived for an MSMPR (Mixed Suspension Mixed Product Removal model approach. Considering the experimental population density distribution courses, a size-dependent growth (SDG phenomenon was taken into account in the kinetic calculations. Five SDG kinetic models recommended in the accessible literature were used for kinetic parameter values estimation. It was proved statistically, that Rojkowski’s two SDG models (hyperbolic and exponential best suit for our own experimental data description. The experimental data presented can be practically applied for improving the constructions of liquid jet-pump DTM crystallizers recommended for reaction crystallization of sparingly soluble inorganic salts (especially for high concentrations of reaction substrates in the modern

Twin-tubes: 3D tracking based on the ATLAS muon drift tubes

International Nuclear Information System (INIS)

Woudstra, M.; Bobbink, G.J.; Eldik, N. van; Graaf, H. van der; Kluit, P.; Koutsman, A.; Limper, M.; Linde, F.; Massaro, G.; Snuverink, J.; Vreeswijk, M.; Groenstege, H.; Koopstra, J.; Mos, S.; Rewiersma, P.; Timmermans, C.; Dijkema, J.

2006-01-01

The Monitored Drift Tubes (MDTs) of the ATLAS Muon Spectrometer have been paired to form so-called twin-tubes to measure the coordinate which runs along the wire direction. This modification endows the MDTs with full 3D track reconstruction using specially designed electronic boards. The performance of the twin-tubes has been measured for an equipped MDT chamber at the ATLAS Muon Cosmic Ray Test Stand at NIKHEF. The efficiency of a twin-tube has been determined to be 99.8%, and the measured resolution 17 cm per hit. By equipping one multilayer consisting of three layers and combining the measurements a resolution of 10 cm has been obtained

Thermoelectric Efficiency Improvement in Vacuum Tubes of Decomposing Liquid Lithium-Ammonia Solutions

International Nuclear Information System (INIS)

Lee, Jungyoon; Kim, Miae; Shim, Kyuchol; Kim, Jibeom; Jeon, Joonhyeon

2013-01-01

Lithium-ammonia (Li-NH 3 ) solutions are possible to be successfully made under the vacuum condition but there still remains a problem of undergoing stable and reliable decomposition in vacuum for high-efficiency thermoelectric power generation. This paper describes a new method for improving the thermoelectric conversion efficiency of Li-NH 3 solutions in vacuum. The proposed method uses a ‘U’-shaped Pyrex vacuum tube for the preparation and decomposition of pure fluid Li-NH 3 solutions. The tube is shaped so that a gas passageway (‘U’) connecting both legs of the ‘U’ helps to balance pressure inside both ends of the tube (due to NH 3 gasification) during decomposition on the hot side. Thermoelectric experimental results show that solution reaction in the ‘U’-shaped tube proceeds more stably and efficiently than in the ‘U’-shaped tube, and consequently, thermoelectric conversion efficiency is improved. It is also proved that the proposed method can provide a reversible reaction, which can rotate between synthesis and decomposition in the tube, for deriving the long-time, high-efficiency thermoelectric power

Improper tube fixation causing a leaky cuff

Directory of Open Access Journals (Sweden)

Gupta Babita

2010-01-01

Full Text Available Leaking endotracheal tube cuffs are common problems in intensive care units. We report a case wherein the inflation tube was damaged by the adhesive plaster used for tube fixation and resulted in leaking endotracheal tube cuff. We also give some suggestions regarding the tube fixation and some remedial measures for damaged inflation system.

NEI You Tube Videos: Amblyopia

Medline Plus

Full Text Available ... YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia ... *PDF files require the free Adobe® Reader® software for viewing. This website is maintained by the ...

Transmission efficiency of neutron guide tube with alignment errors

International Nuclear Information System (INIS)

Kawabata, Yuji; Suzuki, Masatoshi; Sakamoto, Masanobu; Harami, Taikan; Takahashi, Hidetake; Onishi, Nobuaki

1990-01-01

The experimental studies on the neutron transmission efficiencies of neutron guide tubes were carried out by using thermal neutrons from the JAERI electron linac. The neutron guide tube facility on a large scale have been planned on the reconstructed JRR-3 in JAERI. The neutron efficiencies of the 1/10 scale neutron guide tube, which is 2 mm width and 1.8 m length, with and without appreciable alignment errors were studied to evaluate the efficiencies of the planned ones. Calculated results by the Neutron Guide Tube Analysis Code 'NEUGT' were also assessed by these neutron experiments. The experimental results agree well with the calculated results by 'NEUGT' even with alignment errors. From this experimental study, the efficiency of the planned neutron guide tubes is estimated to be good enough for the neutron beam experiments. (author)

Manufacturing and mechanical property test of the large-scale oxide dispersion strengthened martensitic mother tube by hot isostatic pressing and hot extrusion process

International Nuclear Information System (INIS)

Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Fujiwara, Masayuki

2003-09-01

Mass production capability of Oxide Dispersion Strengthened (ODS) ferritic steel cladding (9Cr) is evaluated in the Phase II of the Feasibility Studies on Commercialized Fast Reactor Cycle System. The cost for manufacturing mother tube is a dominant factor in the total cost for manufacturing ODS ferritic cladding. In this study, the large-scale 9Cr-ODS martensitic mother tube was produced by overseas supplier with mass production equipments for commercialized ODS steels. The process of manufacturing the ODS mother tube consists of raw material powder production, mechanical alloying by high energy ball mill, hot isostatic pressing(HIP), and hot extrusion. Following results were obtained in this study. (1) Micro structure of the ODS steels is equivalent to that of domestic products, and fine oxides are uniformly distributed. The mechanical alloying by large capacity (1 ton) ball mill can be satisfactorily carried out. (2) A large scale mother tube (65 mm OD x 48 mm ID x 10,000 mm L), which can produce about 60 pieces of 3 m length ODS ferritic claddings by four times cold rolling, have been successfully manufactured through HIP and Hot Extrusion process. (3) Rough surface of the mother tubes produced in this study can be improved by selecting the reasonable hot extrusion condition. (4) Hardness and tensile strength of the manufactured ODS steels are lower than domestic products with same chemical composition. This is owing to the high aluminum content in the product, and those properties could be improved by decreasing the aluminum content in the raw material powder. (author)

Full scale measurement of wind induced pressures : 1 configuration of wind induced pressures

NARCIS (Netherlands)

Geurts, C.P.W.; Wijen, H.L.M.

1994-01-01

A research project 10 the spectral characteristics of wind induced pressures is in progress in Eindhoven. This project includes both wind tunnel and full scale measurements. Wind induced pressures are measured in full scale at the main building of Eindhoven University of Technology. This paper

A Role for YouTube in Telerehabilitation

OpenAIRE

Manasco, M. Hunter; Barone, Nicholas; Brown, Amanda

2010-01-01

YouTube is a free video sharing website that allows users to post and view videos. Although there are definite limitations in the applicability of this website to telerehabilitation, there are possible uses that should not be overlooked. Certain types of therapy, such as errorless learning therapy for certain language and cognitive deficits can be provided remotely via YouTube. In addition, negative emotional reactions to deficits are known to delay or halt recovery. The social networking cap...

Temperature Dependences for the Reactions of O2- and O- with N and O Atoms in a Selected-Ion Flow Tube Instrument

Science.gov (United States)

2013-10-07

quadrupole mass filter, mass selected, and injected into the flow reactor via a Venturi - type inlet. Ions undergo ∼105 collisions with helium buffer... gas at pressures of 0.4 to 0.8 Torr resulting in complete or near-complete thermalization.10 The higher pressure was used when studying the high...butterfly gate valve resulting in lower pumping speeds and thus longer reaction times. Neutrals were injected 49 cm before the end of the flow tube and

Tube Length and Water Flow

Directory of Open Access Journals (Sweden)

Ben Ruktantichoke

2011-06-01

Full Text Available In this study water flowed through a straight horizontal plastic tube placed at the bottom of a large tank of water. The effect of changing the length of tubing on the velocity of flow was investigated. It was found that the Hagen-Poiseuille Equation is valid when the effect of water entering the tube is accounted for.

Hot Firing of a Full Scale Copper Tubular Combustion Chamber

National Research Council Canada - National Science Library

Cooley, C

2002-01-01

This paper describes the chamber design and hot firing test results for a full-scale copper tubular combustion chamber that has future application in a high-thrust, upper-stage expander cycle engine...

Fatigue Assessment of Full-Scale Retrofitted Orthotropic Bridge Decks

NARCIS (Netherlands)

Teixeira De Freitas, S.; Kolstein, M.H.; Bijlaard, F.S.K.

2017-01-01

Full-scale fatigue tests were performed on two retrofitted orthotropic bridge decks (OBDs). The retrofitting systems consist of adding a second steel plate on the top of the existing deck. The aim is to reduce the stresses at the fatigue-sensitive details and therefore extend the fatigue life of

Tube in shell heat exchangers

International Nuclear Information System (INIS)

Hayden, O.; Willby, C.R.; Sheward, G.E.; Ormrod, D.T.; Firth, G.F.

1980-01-01

An improved tube-in-shell heat exchanger to be used between liquid metal and water is described for use in the liquid metal coolant system of fast breeder reactors. It is stated that this design is less prone to failures which could result in sodium water reactions than previous exchangers. (UK)

Transcriptional evidence for inferred pattern of pollen tube-stigma metabolic coupling during pollination.

Directory of Open Access Journals (Sweden)

Xun Yue

Full Text Available It is difficult to derive all qualitative proteomic and metabolomic experimental data in male (pollen tube and female (pistil reproductive tissues during pollination because of the limited sensitivity of current technology. In this study, genome-scale enzyme correlation network models for plants (Arabidopsis/maize were constructed by analyzing the enzymes and metabolic routes from a global perspective. Then, we developed a data-driven computational pipeline using the "guilt by association" principle to analyze the transcriptional coexpression profiles of enzymatic genes in the consecutive steps for metabolic routes in the fast-growing pollen tube and stigma during pollination. The analysis identified an inferred pattern of pollen tube-stigma ethanol coupling. When the pollen tube elongates in the transmitting tissue (TT of the pistil, this elongation triggers the mobilization of energy from glycolysis in the TT cells of the pistil. Energy-rich metabolites (ethanol are secreted that can be taken up by the pollen tube, where these metabolites are incorporated into the pollen tube's tricarboxylic acid (TCA cycle, which leads to enhanced ATP production for facilitating pollen tube growth. In addition, our analysis also provided evidence for the cooperation of kaempferol, dTDP-alpha-L-rhamnose and cell-wall-related proteins; phosphatidic-acid-mediated Ca2+ oscillations and cytoskeleton; and glutamate degradation IV for γ-aminobutyric acid (GABA signaling activation in Arabidopsis and maize stigmas to provide the signals and materials required for pollen tube tip growth. In particular, the "guilt by association" computational pipeline and the genome-scale enzyme correlation network models (GECN developed in this study was initiated with experimental "omics" data, followed by data analysis and data integration to determine correlations, and could provide a new platform to assist inachieving a deeper understanding of the co-regulation and inter

Corrugated thimble tube for controlling control rod descent in nuclear reactor

International Nuclear Information System (INIS)

Luetzow, H.J.

1981-01-01

A thimble tube construction is described which will provide a controlled descent for a control rod while minimizing the reaction forces which must be absorbed by the thimble tube and reducing the possibility that a foreign particle could interfere with the free descent of a control rod. A thimble tube is formed with helically-corrugate internal walls which cooperate with a control rod contained in the tube in an emergency situation to provide a progressively-increasing hydraulic restraining force as each adjacent corrugation is encountered

Anticipatory Traumatic Reaction: Outcomes Arising From Secondary Exposure to Disasters and Large-Scale Threats.

Science.gov (United States)

Hopwood, Tanya L; Schutte, Nicola S; Loi, Natasha M

2017-09-01

Two studies, with a total of 707 participants, developed and examined the reliability and validity of a measure for anticipatory traumatic reaction (ATR), a novel construct describing a form of distress that may occur in response to threat-related media reports and discussions. Exploratory and confirmatory factor analysis resulted in a scale comprising three subscales: feelings related to future threat; preparatory thoughts and actions; and disruption to daily activities. Internal consistency was .93 for the overall ATR scale. The ATR scale demonstrated convergent validity through associations with negative affect, depression, anxiety, stress, neuroticism, and repetitive negative thinking. The scale showed discriminant validity in relationships to Big Five characteristics. The ATR scale had some overlap with a measure of posttraumatic stress disorder, but also showed substantial separate variance. This research provides preliminary evidence for the novel construct of ATR as well as a measure of the construct. The ATR scale will allow researchers to further investigate anticipatory traumatic reaction in the fields of trauma, clinical practice, and social psychology.

Pelamis wave energy converter. Verification of full-scale control using a 7th scale model

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The Pelamis Wave Energy Converter is a new concept for converting wave energy for several applications including generation of electric power. The machine is flexibly moored and swings to meet the water waves head-on. The system is semi-submerged and consists of cylindrical sections linked by hinges. The mechanical operation is described in outline. A one-seventh scale model was built and tested and the outcome was sufficiently successful to warrant the building of a full-scale prototype. In addition, a one-twentieth scale model was built and has contributed much to the research programme. The work is supported financially by the DTI.

Hydrogen isotope exchange in a metal hydride tube

Energy Technology Data Exchange (ETDEWEB)

Robinson, David B. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2014-09-01

This report describes a model of the displacement of one hydrogen isotope within a metal hydride tube by a different isotope in the gas phase that is blown through the tube. The model incorporates only the most basic parameters to make a clear connection to the theory of open-tube gas chromatography, and to provide a simple description of how the behavior of the system scales with controllable parameters such as gas velocity and tube radius. A single tube can be seen as a building block for more complex architectures that provide higher molar flow rates or other advanced design goals.

Vibration tests on single heat exchanger tubes in air and static water

International Nuclear Information System (INIS)

Collinson, A.E.; Warneford, I.P.

1978-07-01

The vibrational characteristics of a 7 span straight tube and a 26 span U-tube have been investigated for the effects of fluid medium (air/water), tube-grid clearance, tube-grid contact force, vibration transmission and scale. Measured frequency response and mode shapes compared favourably with theoretical values, vibration with pin-pin tube support being most readily excited. The frequency reduction on immersion in water corresponded to an added mass equivalent to the liquid displaced mass. Dynamic magnifiers varied in the range 12 to 135 with mean values of 30 to 40 in water and 45 to 60 in air. Principal vibration modes and damping values were reproducible in a half-scale model of a U-tube. (author)

Full scale model studies of nuclear power stations for earthquake resistance

International Nuclear Information System (INIS)

Kirillov, A.P.; Ambriashvili, Ju. K.; Kozlov, A.V.

Behaviour of nuclear power plants and its equipments under seismic action is not well understood. In the absence of well established method for aseismic deisgn of nuclear power plants and its equipments, it is necessary to carry out experimental investigations on models, fragments and full scale structures. The present study includes experimental investigations of different scale models and on existing nuclear power stations under impulse and explosion effects simulating seismic loads. The experimental work was aimed to develop on model test procedure for nuclear power station and the evaluation of the possible range of dynamic stresses in structures and pipe lines. The results of full-scale investigations of the nuclear reactor show a good agreement of dynamic characteristics of the model and the prototype. The study confirms the feasibility of simulation of model for nuclear power plants. (auth.)

Evaluation of heat transfer tube failure propagation due to sodium-water reaction in steam generator

International Nuclear Information System (INIS)

Nei, Hiromichi

1978-01-01

An evaluation was made of heat transfer tube failure propagation due to sodium-water reaction wastage in a sodium heated steam generator, by comparing an empirically derived wastage equation with leak detector responses. The experimental data agreed well with the wastage equation even for different values of distance-to-nozzle diameter ratio, though the formula had been based on wastage data obtained for only one given distance. The time taken for failure propagation was estimated for a prototype steam generator, and compared with the responses characteristics of acoustic detectors and level gages. It was found that there exists a range of leak rate between 0.5 and 100 g/sec, where the level gage can play a useful role in leak detection. The acoustic detector can be expected to respond more rapidly than the cover gas pressure gage, if noise is kept below ten times the value observed in an experimental facility, SWAT-2. (auth.)

Gastrostomy Tube (G-Tube)

Science.gov (United States)

... any of these problems: a dislodged tube a blocked or clogged tube any signs of infection (including redness, swelling, or warmth at the tube site; discharge that's yellow, green, or foul-smelling; fever) excessive bleeding or drainage from the tube site severe abdominal pain lasting ...

FULL SCALE REGENERABLE HEPA FILTER DESIGN USING SINTERED METAL FILTER ELEMENTS

International Nuclear Information System (INIS)

Gil Ramos; Kenneth Rubow; Ronald Sekellick

2002-01-01

A Department of Energy funded contract involved the development of porous metal as a HEPA filter, and the subsequent design of a full-scale regenerable HEPA filtration system (RHFS). This RHFS could replace the glass fiber HEPA filters currently being used on the high level waste (HLW) tank ventilation system with a system that would be moisture tolerant, durable, and cleanable in place. The origins of the contract are a 1996 investigation at the Savannah River Technology Center (SRTC) regarding the use of porous metal as a HEPA filter material. This contract was divided into Phases I, IIA and IIB. Phase I of the contract evaluated simple filter cylinders in a simulated High Level Waste (HLW) environment and the ability to clean and regenerate the filter media after fouling. Upon the successful completion of Phase I, Phase IIA was conducted, which included lab scale prototype testing and design of a full-scale system. The work completed under Phase IIA included development of a full-scale system design, development of a filter media meeting the HEPA filtration efficiency that would also be regenerable using prescribed cleaning procedures, and the testing of a single element system prototype at Savannah River. All contract objectives were met. The filter media selected was a nickel material already under development at Mott, which met the HEPA filtration efficiency standard. The Mott nickel media met and exceeded the HEPA requirement, providing 99.99% removal against a requirement of 99.97%. Double open-ended elements of this media were provided to the Savannah River Test Center for HLW simulation testing in the single element prototype filter. These elements performed well and further demonstrated the practicality of a metallic media regenerable HEPA filter system. An evaluation of the manufacturing method on many elements demonstrated the reproducibility to meet the HEPA filtration requirement. The full-scale design of the Mott RHFS incorporated several important

Impact of compost process conditions on organic micro pollutant degradation during full scale composting.

Science.gov (United States)

Sadef, Yumna; Poulsen, Tjalfe Gorm; Bester, Kai

2015-06-01

Knowledge about the effects of oxygen concentration, nutrient availability and moisture content on removal of organic micro-pollutants during aerobic composting is at present very limited. Impact of oxygen concentration, readily available nitrogen content (NH4(+), NO3(-)), and moisture content on biological transformation of 15 key organic micro-pollutants during composting, was therefore investigated using bench-scale degradation experiments based on non-sterile compost samples, collected at full-scale composting facilities. In addition, the adequacy of bench-scale composting experiments for representing full-scale composting conditions, was investigated using micro-pollutant concentration measurements from both bench- and full-scale composting experiments. Results showed that lack of oxygen generally prevented transformation of organic micro-pollutants. Increasing readily available nitrogen content from about 50 mg N per 100 g compost to about 140 mg N per 100 g compost actually reduced micro-pollutant transformation, while changes in compost moisture content from 50% to 20% by weight, only had minor influence on micro-pollutant transformation. First-order micro-pollutant degradation rates for 13 organic micro-pollutants were calculated using data from both full- and bench-scale experiments. First-order degradation coefficients for both types of experiments were similar and ranged from 0.02 to 0.03 d(-1) on average, indicating that if a proper sampling strategy is employed, bench-scale experiments can be used to represent full-scale composting conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Full Dynamic Reactions in the Basic Shaft Bearings of Big Band Saw Machines

Science.gov (United States)

Marinov, Boycho

2013-03-01

The band saws machines are a certain class woodworking machines for longitudinal or transversal cutting as well as for curvilinear wood cutting. These machines saw the wood through a band-saw blade and two feeding wheels. These wheels usually are very large and they are produced with inaccuracies. The centre of mass of the disc is displaced from the axis of rotation of the distance e (eccentricity) and the axis of the disk makes an angle with the axis of rotation. In this paper, the dy- namic reactions in the bearings of the basic shaft, which drives the band saw machines, are analyzed. These reactions are caused by the external loading and the kinematics and the mass characteristics of the rotating disk. The expressions for the full dynamic reactions are obtained. These expressions allow the parameters of the machines to be chosen in such a way that the loading in the shaft and the bearings to be minimal.

Full-scale ANANOX (R) system performance | Garuti | Water SA

African Journals Online (AJOL)

This paper reports the results of the first experimental investigations carried out on the only existing full-scale plant that makes use of the biological treatment system known as ANANOX(R). This system was first set up by the Italian research staff at ENEA (Agency for New Technologies, Energy and Environment) and consists ...

NEI You Tube Videos: Amblyopia

Medline Plus

Full Text Available ... Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract Convergence ... is maintained by the NEI Office of Science Communications, Public Liaison, and Education. Technical questions about this ...

Reaction monitoring using hyperpolarized NMR with scaling of heteronuclear couplings by optimal tracking

Science.gov (United States)

Zhang, Guannan; Schilling, Franz; Glaser, Steffen J.; Hilty, Christian

2016-11-01

Off-resonance decoupling using the method of Scaling of Heteronuclear Couplings by Optimal Tracking (SHOT) enables determination of heteronuclear correlations of chemical shifts in single scan NMR spectra. Through modulation of J-coupling evolution by shaped radio frequency pulses, off resonance decoupling using SHOT pulses causes a user-defined dependence of the observed J-splitting, such as the splitting of 13C peaks, on the chemical shift offset of coupled nuclei, such as 1H. Because a decoupling experiment requires only a single scan, this method is suitable for characterizing on-going chemical reactions using hyperpolarization by dissolution dynamic nuclear polarization (D-DNP). We demonstrate the calculation of [13C, 1H] chemical shift correlations of the carbanionic active sites from hyperpolarized styrene polymerized using sodium naphthalene as an initiator. While off resonance decoupling by SHOT pulses does not enhance the resolution in the same way as a 2D NMR spectrum would, the ability to obtain the correlations in single scans makes this method ideal for determination of chemical shifts in on-going reactions on the second time scale. In addition, we present a novel SHOT pulse that allows to scale J-splittings 50% larger than the respective J-coupling constant. This feature can be used to enhance the resolution of the indirectly detected chemical shift and reduce peak overlap, as demonstrated in a model reaction between p-anisaldehyde and isobutylamine. For both pulses, the accuracy is evaluated under changing signal-to-noise ratios (SNR) of the peaks from reactants and reaction products, with an overall standard deviation of chemical shift differences compared to reference spectra of 0.02 ppm when measured on a 400 MHz NMR spectrometer. Notably, the appearance of decoupling side-bands, which scale with peak intensity, appears to be of secondary importance.

Validation and cultural adaptation of a German version of the Physicians' Reactions to Uncertainty scales

Directory of Open Access Journals (Sweden)

Joest Katharina

2007-06-01

Full Text Available Abstract Background The aim of the study was to examine the validity of a translated and culturally adapted version of the Physicians' Reaction to Uncertainty scales (PRU in primary care physicians. Methods In a structured process, the original questionnaire was translated, culturally adapted and assessed after administering it to 93 GPs. Test-retest reliability was tested by sending the questionnaire to the GPs again after two weeks. Results The principal factor analysis confirmed the postulated four-factor structure underlying the 15 items. In contrast to the original version, item 5 achieved a higher loading on the 'concern about bad outcomes' scale. Consequently, we rearranged the scales. Good item-scale correlations were obtained, with Pearson's correlation coefficient ranging from 0.56–0.84. As regards the item-discriminant validity between the scales 'anxiety due to uncertainty' and 'concern about bad outcomes', partially high correlations (Pearson's correlation coefficient 0.02–0.69; p Conclusion Dealing with uncertainty is an important issue in daily practice. The psychometric properties of the rearranged German version of the PRU are satisfying. The revealed floor effects do not limit the significance of the questionnaire. Thus, the German version of the PRU could contribute to the further evaluation of the impact of uncertainty in primary care physicians.

Transferability of decompression wave speed measured by a small-diameter shock tube to full size pipelines and implications for determining required fracture propagation resistance

International Nuclear Information System (INIS)

Botros, K.K.; Geerligs, J.; Rothwell, Brian; Carlson, Lorne; Fletcher, Leigh; Venton, Philip

2010-01-01

The control of propagating ductile (or tearing) fracture is a fundamental requirement in the fracture control design of pipelines. The Battelle two-curve method developed in the early 1970s still forms the basis of the analytical framework used throughout the industry. GASDECOM is typically used for calculating decompression speed, and idealizes the decompression process as isentropic and one-dimensional, taking no account of frictional effects. While this approximation appears not to have been a major issue for large-diameter pipes and for moderate pressures (up to 12 MPa), there have been several recent full-scale burst tests at higher pressures and smaller diameters for which the measured decompression velocity has deviated progressively from the predicted values, in general towards lower velocities. The present research was focused on determining whether pipe diameter was a major factor that could limit the applicability of frictionless models such as GASDECOM. Since potential diameter effects are primarily related to wall friction, which in turn is related to the ratio of surface roughness-to-diameter, an experimental approach was developed based on keeping the diameter constant, at a sufficiently small value to allow for an economical experimental arrangement, and varying the internal roughness. A series of tests covering a range of nominal initial pressures from 10 to 21 MPa, and involving a very lean gas and three progressively richer compositions, were conducted using two specialized high-pressure shock tubes (42 m long, I.D. = 38.1 mm). The first is honed to an extremely smooth surface finish, in order to minimize frictional effects and better simulate the behaviour of larger-diameter pipelines, while the second has a higher internal surface roughness. The results show that decompression wave speeds in the rough tube are consistently slower than those in the smooth tube under the same conditions of mixture composition and initial pressure and temperature

Pediatric cuffed endotracheal tubes

Directory of Open Access Journals (Sweden)

Neerja Bhardwaj

2013-01-01

Full Text Available Endotracheal intubation in children is usually performed utilizing uncuffed endotracheal tubes for conduct of anesthesia as well as for prolonged ventilation in critical care units. However, uncuffed tubes may require multiple changes to avoid excessive air leak, with subsequent environmental pollution making the technique uneconomical. In addition, monitoring of ventilatory parameters, exhaled volumes, and end-expiratory gases may be unreliable. All these problems can be avoided by use of cuffed endotracheal tubes. Besides, cuffed endotracheal tubes may be of advantage in special situations like laparoscopic surgery and in surgical conditions at risk of aspiration. Magnetic resonance imaging (MRI scans in children have found the narrowest portion of larynx at rima glottides. Cuffed endotracheal tubes, therefore, will form a complete seal with low cuff pressure of <15 cm H 2 O without any increase in airway complications. Till recently, the use of cuffed endotracheal tubes was limited by variations in the tube design marketed by different manufacturers. The introduction of a new cuffed endotracheal tube in the market with improved tracheal sealing characteristics may encourage increased safe use of these tubes in clinical practice. A literature search using search words "cuffed endotracheal tube" and "children" from 1980 to January 2012 in PUBMED was conducted. Based on the search, the advantages and potential benefits of cuffed ETT are reviewed in this article.

Characterization of Membrane Foulants in Full-scale and Lab-scale Membrane Bioreactors for Wastewater Treatment and Reuse

KAUST Repository

Matar, Gerald

2015-12-01

Membrane bioreactors (MBRs) offer promising solution for wastewater treatment and reuse to address the problem of water scarcity. Nevertheless, this technology is still facing challenges associated with membrane biofouling. This phenomenon has been mainly investigated in lab-scale MBRs with little or no insight on biofouling in full-scale MBR plants. Furthermore, the temporal dynamics of biofouling microbial communities and their extracellular polymeric substances (EPS) are less studied. Herein, a multidisciplinary approach was adopted to address the above knowledge gaps in lab- and full-scale MBRs. In the full-scale MBR study, 16S rRNA gene pyrosequencing with multivariate statistical analysis revealed that the early and mature biofilm communities from five full-scale MBRs differed significantly from the source community (i.e. activated sludge), and random immigration of species from the source community was unlikely to shape the community structure of biofilms. Also, a core biofouling community was shared between the five MBR plants sampled despite differences in their operating conditions. In the lab-scale MBR studies, temporal dynamics of microbial communities and their EPS products were monitored on different hydrophobic and hydrophilic membranes during 30 days. At the early stages of filtration (1 d), the same early colonizers belonging to the class Betaproteobacteria were identified on all the membranes. However, their relative abundance decreased on day 20 and 30, and sequence reads belonging to the phylum Firmicutes and Chlorobi became dominant on all the membranes on day 20 and 30. In addition, the intrinsic membrane characteristic did not select any specific EPS fractions at the initial stages of filtration and the same EPS foulants developed with time on the hydrophobic and hydrophilic membranes. Our results indicated that the membrane surface characteristics did not select for specific biofouling communities or EPS foulants, and the same early

Rechargeable biofilm-controlling tubing materials for use in dental unit water lines.

Science.gov (United States)

Luo, Jie; Porteous, Nuala; Sun, Yuyu

2011-08-01

A simple and practical surface grafting approach was developed to introduce rechargeable N-halamine-based antimicrobial functionality onto the inner surfaces of continuous small-bore polyurethane (PU) dental unit waterline (DUWL) tubing. In this approach, tetrahydrofuran (THF) solution of a free-radical initiator, dicumyl peroxide (DCP), flowed through the PU tubing (inner diameter of 1/16 in., or 1.6 mm) to diffuse DCP into the tubing's inner walls, which was used as initiator in the subsequent grafting polymerization of methacrylamide (MAA) onto the tubing. Upon chlorine bleach treatment, the amide groups of the grafted MAA side chains were transformed into acyclic N-halamines. The reactions were confirmed with attenuated total reflectance infrared (ATR) spectra and iodometric titration. The mechanical properties of the tubing were not significantly affected by the grafting reactions. The biofilm-controlling function of the new N-halamine-based PU tubing was evaluated with Pseudomonas aeruginosa (P. aeruginosa), one of the most isolated water bacteria from DUWLs, in a continuous bacterial flow model. Bacteria culturing and SEM studies showed that the inner surfaces of the new N-halamine-based PU tubing completely prevented bacterial biofilm formation for at least three to four weeks. After that, bacteria began to colonize the tubing surface. However, the lost function was fully regenerated by exposing the tubing inner surfaces to diluted chlorine bleach. The recharging process could be repeated periodically to further extend the biofilm-controlling duration for long-term applications.

Multi-target Wastage Phenomena on Steam Generator Tubes During an SWR Event

International Nuclear Information System (INIS)

Jeong, Ji Young; Kim, Jong Man; Kim, Tae Joon; Eoh, Jae Hyuk; Choi, Jong Hyeun; Lee, Yong Bum

2011-01-01

The Korean sodium cooled fast reactor, KALIMER- 600 (Korea Advanced LIquid MEtal Reactor) of which the electric output is 600MWe, was developed. The steam generator (SG) of this system is a shell-and-tube type counter-current flow heat exchanger, which is vertically oriented with fixed tube-sheets. A direct heat exchange occurs between the shell-side sodium and the tube-side water at the SG unit. Feed-water enters the inlet nozzle at the lower part of the unit and it flows upward along the helically coiled heat transfer tubes. The inflow sodium is cooled down at the bundle region and then flows out through the sodium outlet nozzle at the bottom of the unit. The typical configuration of the KALIMER-600 SG is shown in Figure 1. In a steam generator, sodium and water are separated by the heat transfer tube wall and it makes a strong pressure boundary between the shell-side sodium and the tube-side water/steam. For this reason, if there is a small hole or crack, even with a pin hole, on heat transfer tubes, a large amount of water/steam would leak into the liquid sodium due to the high pressure difference more than 150 bars, and an exothermic sodium-water chemical reaction takes place as a result. This type of sodium-water reaction (SWR) has been considered as one of the most important safety issues to be resolved. From previous studies, it was obviously figured out that the number of ruptured tubes during an SWR event is one of the most significant factors to determine the temperature and pressure transient. Any subsequent tube rupture behavior in the vicinity of the initially postulated single ruptured tube should be evaluated by considering the single- and multi-target wastage phenomena. Wastage is defined as damage to the structural material (e.g. heat transfer tubes) due to an impingement of the highly corrosive reaction product. Since the impingement may cause wastage of the neighboring heat transfer tubes, a subsequent tube failure can occur in a very short time

Development of a helical-coil double wall tube steam generator for 4S reactor

International Nuclear Information System (INIS)

Kitajima, Yuko; Maruyama, Shigeki; Jimbo, Noboru; Hino, Takehisa; Sato, Katsuhiko

2011-01-01

The 4S, Super-Safe Small and Simple, is a small-sized sodium-cooled fast reactor. A fast reactor usually uses sodium as a coolant to transfer heat from core to turbine/generator system. The heat of the intermediate heat transport system and that of the water stream systems are exchanged by the steam generator (SG) tubes. If the tube failure occurs, a sodium/water reaction could be occurred. To prevent the reaction and enhance safety, a helical-coil-type double wall tube with wire mesh interlayer and continuous monitoring systems of tube failure are applied to the SG of the 4S. The development and general features of this type double wall tube were described in Ref. 1) and Ref. 2). Those paper summarized following results; The tubes studied in these references were straight type. To establish this SG, development of manufacturing method of helical-coil-type double wall tube and validation of the tube failure monitoring system are needed. In this study, three demonstration tests have been performed; welding test of the double wall tube to manufacture the tubes with 70-80m length, assembling test of the helical-coil tube, and confirmation test of the tube processing system using the fabricated helical-coil tubes. As a result, following technologies have been successfully established. (1) Development of the welding techniques for manufacturing of the helical-coil-type double wall tube with wire mesh interlayer. (2) The confirmation test for manufacturing the helical coil tube of the SG. (author)

Steam generator tube performance

International Nuclear Information System (INIS)

Tatone, O.S.; Pathania, R.S.

1982-04-01

The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1980. Tube defects occurred at 38% of the 97 reactors surveyed. This is a marginal improvement over 1979 when defects occurred at 41% of the reactors. The number of failed tubes was also lower, 0.14% of the tubes in service in 1980 compared with 0.20% of those in service in 1979. Analysis of the causes of these failures indicates that stress corrosion cracking was the leading failure mechanism. Reactors that used all-volatile treatment of secondary water, with or without full-flow condensate demineralization since start-up showed the lowest incidence of corrosion-related defects

Full-scale mark II CRT program data report no. 7

International Nuclear Information System (INIS)

Kukita, Yutaka; Namatame, Ken; Yamamoto, Nobuo; Takeshita, Isao; Shiba, Masayoshi

1980-03-01

The Full-Scale Mark II CRT (Containment Response Test) Program was initiated in 1977 to provide a data base for evaluation of the LOCA hydrodynamic loads in the BWR Mark II pressure suppression system. The test facility is 1/18 in volume and has a wetwell which is a full-scale replica of one 20 0 -sector of that of a reference Mark II. This report documents test data obtained from TEST 3102, which is a large (200 mm) water break test performed on June 29, 1979. The test was performed for a supernominal break area (approx. 160% of the scaled break area for a postulated double-ended break in the recirculation line) to obtain vent steam mass fluxes ranging up to the maximum design value of the actual plants. Before the initiation of the test more than 90% of the drywell air was replaced by steam and transferred into wetwell airspace to reduce the air content in the vent flow during the test. Because of this pre-test treatment (so-called prepurging) the test data obtained for high- and intermediate-steam-flux condensation oscillations are believed to be to a high degree on conservative side. (author)

Nuclear Reactions in Micro/Nano-Scale Metal Particles

International Nuclear Information System (INIS)

Kim, Y. E.

2013-01-01

Low-energy nuclear reactions in micro/nano-scale metal particles are described based on the theory of Bose-Einstein condensation nuclear fusion (BECNF). The BECNF theory is based on a single basic assumption capable of explaining the observed LENR phenomena; deuterons in metals undergo Bose-Einstein condensation. The BECNF theory is also a quantitative predictive physical theory. Experimental tests of the basic assumption and theoretical predictions are proposed. Potential application to energy generation by ignition at low temperatures is described. Generalized theory of BECNF is used to carry out theoretical analyses of recently reported experimental results for hydrogen-nickel system. (author)

Nuclear Reactions in Micro/Nano-Scale Metal Particles

Science.gov (United States)

Kim, Y. E.

2013-03-01

Low-energy nuclear reactions in micro/nano-scale metal particles are described based on the theory of Bose-Einstein condensation nuclear fusion (BECNF). The BECNF theory is based on a single basic assumption capable of explaining the observed LENR phenomena; deuterons in metals undergo Bose-Einstein condensation. The BECNF theory is also a quantitative predictive physical theory. Experimental tests of the basic assumption and theoretical predictions are proposed. Potential application to energy generation by ignition at low temperatures is described. Generalized theory of BECNF is used to carry out theoretical analyses of recently reported experimental results for hydrogen-nickel system.

COMPARATIVE ANALYSIS OF BLOOD GROUPING IN HEALTHY BLOOD DONOR USING GEL CARD TECHNIQUE AND TUBE METHOD

Directory of Open Access Journals (Sweden)

Muhammad Usman

2016-12-01

Full Text Available Blood grouping is a vital test in pre-transfusion testing. Both tube and gel agglutination assays are used for ABO grouping. The main object of this study was to compare ABO grouping and D typing on tube and gel agglutination assay in order to assess the efficacy of each technique. A total of 100 healthy blood donors irrespective of age and sex were included in this study. Results showed that there is no significant difference between these two techniques. However, in 10 samples it was detected that the reaction strength in serum ABO grouping by gel agglutination assay is varied by only one grade when compared to tube agglutination assay. Due to numerous positive effects of gel assay it is more beneficial to implement this technique in the setups where blood banks bear heavy routine work load.

Evaluation of the residual stress field in a steam generator end tube after hydraulic expansion

International Nuclear Information System (INIS)

Thiel, F.; Kang, S.; Chabrerie, J.

1994-01-01

This paper presents a finite element elastoplastic model of a nuclear steam generator end tube, used to evaluate the residual stress field existing after hydraulic expansion of the tube into the tubesheet of the heat exchanger. This model has been tested against an experimental hydraulic expansion, carried out on full scale end tubes. The operation was monitored thanks to strain gages localized on the outer surface of the tubes, subjected to elastoplastic deformations. After a presentation of the expansion test and the description of the numerical model, the authors compare the stress fields issues from the gages and from the model. The comparison shows a good agreement. These results allow them to calculate the stress field resulting from normal operating conditions, while taking into account a correct initial state of stress. Therefore the authors can improve the understanding of the behavior of a steam generator end tube, with respect to stress corrosion cracking and crack growth

One-fifth-scale and full-scale fuel element rocking tests

International Nuclear Information System (INIS)

Nau, P.V.; Olsen, B.E.

1978-06-01

Using 1 / 5 -scale and 1 / 1 -scale (prototype H451) fuel elements, one, two, or three stacked elements on a clamped base element were rocked from an initial release position. Relative displacement, rock-down loads, and dowel pin shear forces were measured. A scaled comparison between 1 / 5 -scale and 1 / 1 -scale results was made to evaluate the model scaling laws, and an error analysis was performed to assess the accuracy and usefulness of the test data

Tube vibration in industrial size test heat exchanger

International Nuclear Information System (INIS)

Halle, H.; Wambsganss, M.W.

1980-03-01

Tube vibration data from tests of a specially built and instrumented, industrial-type, shell-and-tube heat exchanger are reported. The heat exchanger is nominally 0.6 m (2 ft) in dia and 3.7 m (12 ft) long. Both full tube and no-tubes-in-window bundles were tested for inlet/outlet nozzles of different sizes and with the tubes supported by seven, equally-spaced, single-segmental baffles. Prior to water flow testing, natural frequencies and damping of representative tubes were measured in air and water. Flow testing was accomplished by increasing the flow rates in stepwise fashion and also by sweeping through a selected range of flow rates. The primary variables measured and reported are tube accelerations and/or displacements and pressure drop through the bundle. Tests of the full tube bundle configuration revealed tube rattling to occur at intermediate flow rates, and fluidelastic instability, with resultant tube impacting, to occur when the flow rate exceeded a threshold level; principally, the four-span tubes were involved in the regions immediately adjacent to the baffle cut. For the range of flow rates tested, fluidelastic instability was not achieved in the no-tubes-in-window bundle; in this configuration the tubes are supported by all seven baffles and are, therefore, stiffer

Categorising YouTube

Directory of Open Access Journals (Sweden)

Thomas Mosebo Simonsen

2011-09-01

Full Text Available This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC of YouTube. The article investigates the construction of navigationprocesses on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within the interacting relationship of new and old genres are discussed. It is argued that the utility of a conventional categorical system is primarily of analytical and theoretical interest rather than as a practical instrument.

Corrosion evaluation of heat recovery steam generator superheater tube in two methods of testing: Tafel polarization and electrochemical impedance spectroscopy (EIS)

Science.gov (United States)

Santoso, Rio Pudjidarma; Riastuti, Rini

2018-05-01

The purpose of this research is to evaluate the corrosion process which occurs on the water side of Heat Recovery Steam Generator (HRSG) superheater tube. The tube was 13CrMo44 and divided into 3 types of specimen: new tube, used tube (with oxide layer on surface), cleaned-used tube (without oxide layer on surface). The evaluation of corrosion parameters wasperformed using deaerated ultra-high purity water (boiler feed water) in two methods of testing: Tafel polarization and Electrochemical Impedance Spectroscopy (EIS). Tafel polarization was excellent as its capability to show the value of corrosion current and the corrosion rate explicitly, on the other hand, EIS was excellent as its capability to explain for corrosion mechanism on metal interface in detail. Both methods showed that the increase of electrolyte temperature from 25°C to 55°C would increase the corrosion rate with the mechanism of decreasing polarization resistance due to thinning out the passive film thickness and enlarge the area of reduction reaction of cathode. Magnetite oxide scale which is laid on the surface of used tube specimen shows protective nature to reduce the corrosion rate, and clear up this oxide would increase the corrosion rate back as new tube.

Plan for 3-D full-scale earthquake testing facility

International Nuclear Information System (INIS)

Ohtani, K.

2001-01-01

Based on the lessons learnt from the Great Hanshin-Awaji Earthquake, National Research Institute for Earth Science and Disaster Prevention plan to construct the 3-D Full-Scale Earthquake Testing Facility. This will be the world's largest and strongest shaking table facility. This paper describes the outline of the project for this facility. This facility will be completed in early 2005. (author)

Competition between abstraction and exchange channels in H + HCN reaction: Full-dimensional quantum dynamics

Energy Technology Data Exchange (ETDEWEB)

Jiang, Bin; Guo, Hua, E-mail: hguo@unm.edu [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

2013-12-14

Dynamics of the title reaction is investigated on an ab initio based potential energy surface using a full-dimensional quantum wave packet method within the centrifugal sudden approximation. It is shown that the reaction between H and HCN leads to both the hydrogen exchange and hydrogen abstraction channels. The exchange channel has a lower threshold and larger cross section than the abstraction channel. It also has more oscillations due apparently to quantum resonances. Both channels are affected by long-lived resonances supported by potential wells. Comparison with experimental cross sections indicates underestimation of the abstraction barrier height.

Two-scale large deviations for chemical reaction kinetics through second quantization path integral

International Nuclear Information System (INIS)

Li, Tiejun; Lin, Feng

2016-01-01

Motivated by the study of rare events for a typical genetic switching model in systems biology, in this paper we aim to establish the general two-scale large deviations for chemical reaction systems. We build a formal approach to explicitly obtain the large deviation rate functionals for the considered two-scale processes based upon the second quantization path integral technique. We get three important types of large deviation results when the underlying two timescales are in three different regimes. This is realized by singular perturbation analysis to the rate functionals obtained by the path integral. We find that the three regimes possess the same deterministic mean-field limit but completely different chemical Langevin approximations. The obtained results are natural extensions of the classical large volume limit for chemical reactions. We also discuss its implication on the single-molecule Michaelis–Menten kinetics. Our framework and results can be applied to understand general multi-scale systems including diffusion processes. (paper)

Mini implant supported molar tubes: A novel method for attaching the molar tubes

Directory of Open Access Journals (Sweden)

Nitin V Muralidhar

2017-01-01

Full Text Available Banding or bonding procedures have been the only means of attaching molar tubes onto the permanent molar teeth till date in the field of orthodontics. This clinical innovation aims to include the use of mini implant for the purpose of attaching the molar tubes thereby eliminating the iatrogenic effects of banding and bonding of the teeth.

A selected ion flow tube study of the ion molecule association reactions of protonated (MH+), nitrosonated (MNO+) and dehydroxidated (M-OH)(+) carboxylic acids (M) with H2O

Czech Academy of Sciences Publication Activity Database

Brůhová Michalčíková, R.; Španěl, Patrik

2014-01-01

Roč. 368, JUL 2014 (2014), s. 15-22 ISSN 1387-3806 R&D Projects: GA ČR GA13-28882S Institutional support: RVO:61388955 Keywords : ion molecule reactions * proton transfer * selected ion flow tube mass spectrometry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.972, year: 2014

Microbial diversity in a full-scale anaerobic reactor treating high ...

African Journals Online (AJOL)

Microbial characteristics in the up-flow anaerobic sludge blanket reactor (UASB) of a full-scale high concentration cassava alcohol wastewater plant capable of anaerobic hydrocarbon removal were analyzed using cultivation-independent molecular methods. Forty-five bacterial operational taxonomic units (OTUs) and 24 ...

Experimental study on the connection property of full-scale composite member

Science.gov (United States)

Panpan, Cao; Qing, Sun

2018-01-01

The excellent properties of composite result in its increasingly application in electric power construction, however there are less experimental studies on full-scale composite member connection property. Full-scale experiments of the connection property between E-glass fiber/epoxy reinforced polymer member and steel casing in practical engineering have been conducted. Based on the axial compression test of the designed specimens, the failure process and failure characteristics were observed, the load-displacement curves and strain distribution of the specimens were obtained. The finite element analysis was used to get the tensile connection strength of the component. The connection property of the components was analyzed to provide basis of the casing connection of GFRP application in practical engineering.

Bioremediation at a global scale: from the test tube to planet Earth.

Science.gov (United States)

de Lorenzo, Víctor; Marlière, Philippe; Solé, Ricard

2016-09-01

Planet Earth's biosphere has evolved over billions of years as a balanced bio-geological system ultimately sustained by sunpower and the large-scale cycling of elements largely run by the global environmental microbiome. Humans have been part of this picture for much of their existence. But the industrial revolution started in the XIX century and the subsequent advances in medicine, chemistry, agriculture and communications have impacted such balances to an unprecedented degree - and the problem has nothing but exacerbated in the last 20 years. Human overpopulation, industrial growth along with unsustainable use of natural resources have driven many sites and perhaps the planetary ecosystem as a whole, beyond recovery by spontaneous natural means, even if the immediate causes could be stopped. The most conspicuous indications of such a state of affairs include the massive change in land use, the accelerated increase in the levels of greenhouse gases, the frequent natural disasters associated to climate change and the growing non-recyclable waste (e.g. plastics and recalcitrant chemicals) that we release to the Environment. While the whole planet is afflicted at a global scale by chemical pollution and anthropogenic emissions, the ongoing development of systems and synthetic biology, metagenomics, modern chemistry and some key concepts from ecological theory allow us to tackle this phenomenal challenge and propose large-scale interventions aimed at reversing and even improving the situation. This involves (i) identification of key reactions or processes that need to be re-established (or altogether created) for ecosystem reinstallation, (ii) implementation of such reactions in natural or designer hosts able to self-replicate and deliver the corresponding activities when/where needed in a fashion guided by sound ecological modelling, (iii) dispersal of niche-creating agents at a global scale and (iv) containment, monitoring and risk assessment of the whole process

Assessments of CHF correlations based on full-scale rod bundle experiments

International Nuclear Information System (INIS)

Sardh, K.; Becker, K.M.

1986-02-01

In the present study the Barnett, the Becker, the Biasi, the CISE-4, the XN-1, the EPRI and the Bezrukov burnout correlations have been compared with burnout measurements obtained with full scale 81, 64, 36 and 37-rod bundles. The total power as well as the local power hypothesis was employed for the comparisons. The results clearly indicated that the Biasi and the CISE-4 correlations do not predict the burnout conditions in full-scale rod bundles. Since, these correlations yield non-conservative results their use in computer programs as for instance RELAP, TRAC or NORA should be avoided. Considering that the effects of spacers were not included in the predictions, the Becker and the Bezrukov correlations were in excellent agreement with the experimental data. However, it should be pointed out that the Bezrukov correlation only covered the 70 and 90 bar data, while the Becker correlation agreed with the experimental data in the whole pressure range between 30 and 90 bar. The Barnett, the XN-1 and the EPRI correlations were also in satisfactory agreement with the experiments. We therefore conclude that for predictions of the burnout conditions in full-scale BWR rod bundles the Becker correlation should be employed. (author)

Full-scale photobioreactor for biotreatment of olive washing water: Structure and diversity of the microalgae-bacteria consortium.

Science.gov (United States)

Maza-Márquez, P; González-Martínez, A; Rodelas, B; González-López, J

2017-08-01

The performance of a full-scale photobioreactor (PBR) for the treatment of olive washing water (OWW) was evaluated under different HRTs (5-2days). The system was able to treat up to 3926L OWWday -1 , and consisted of an activated-carbon pretreatment column and a tubular PBR unit (80 tubes, 98.17L volume, 2-m height, 0.25m diameter). PBR was an effective and environmentally friendly method for the removal of phenols, COD, BOD 5 , turbidity and color from OWW (average efficiencies 94.84±0.55%, 85.86±1.24%, 99.12±0.17%, 95.86±0.98% and 87.24±0.91%, respectively). The diversity of total bacteria and microalgae in the PBR was analyzed using Illumina-sequencing, evaluating the efficiency of two DNA extraction methods. A stable microalgae-bacteria consortium was developed throughout the whole experimentation period, regardless of changes in HRT, temperature or solar radiation. MDS analyses revealed that the interplay between green algae (Sphaeropleales), cyanobacteria (Hapalosiphon) and Proteobacteria (Rhodopseudomonas, Azotobacter) played important roles in OWW bioremediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of LEAP-JET code for sodium-water reaction analysis. Validation by sodium-water reaction tests (SWAT-1R)

International Nuclear Information System (INIS)

Seino, Hiroshi; Hamada, Hirotsugu

2004-03-01

The sodium-water reaction event in an FBR steam generator (SG) has influence on the safety, economical efficiency, etc. of the plant, so that the selection of design base leak (DBL) of the SG is considered as one of the important matters. The clarification of the sodium-water reaction phenomenon and the development of an analysis model are necessary to estimate the sodium-water reaction event with high accuracy and rationality in selecting the DBL. The reaction jet model is pointed out as a part of the necessary improvements to evaluate the overheating tube rupture of large SGs, since the behavior of overheating tube rupture is largely affected by the reaction jet conditions outside the tube. Therefore, LEAP-JET has been developed as an analysis code for the simulation of sodium-water reactions. This document shows the validation of the LEAP-JET code by the Sodium-Water Reaction Test (SWAT-1R). The following results have been obtained: (1) The reaction rate constant, K, is estimated at between 0.001≤K≤0.1 from the LEAP-JET analysis of the SWAT-1R data. (2) The analytical results on the high-temperature region and the behaviors of reaction consumption (Na, H 2 O) and products (H 2 , NaOH, Na 2 O) are considered to be physically reasonable. (3) The LEAP-JET analysis shows the tendency of overestimation in the maximum temperature and temperature distribution of the reaction jet. (4) In the LEAP-JET analysis, the numerical calculation becomes unstably, especially in the mesh containing quite small sodium mass. Therefore, it is necessary to modify the computational algorism to stabilize it and obtain the optimum value of K in sodium-water reactions. (author)

Advanced evacuated tube collectors

Science.gov (United States)

Schertz, W. W.; Hull, J. R.; Winston, R.; Ogallagher, J.

1985-04-01

The essence of the design concept for these new collectors is the integration of moderate levels of nonimaging concentration inside the evacuated tube itself. This permanently protects the reflection surfaces and allows the use of highly reflecting front surface mirrors with reflectances greater than 95%. Previous fabrication and long term testing of a proof-of-concept prototype has established the technical success of the concept. Present work is directed toward the development of a manufacturable unit that will be suitable for the widest possible range of applications. Design alternatives include scaling up the original prototype's tube diameter from 5 cm to 10 cm, using an internal shaped metal concentrating reflector, using a variety of profile shapes to minimize so-called gap losses and accommodate both single ended and double-ended flow geometries, and allowing the use of heat pipes for the absorber tube.

Integration test of ITER full-scale vacuum vessel sector

International Nuclear Information System (INIS)

Nakahira, M.; Koizumi, K.; Oka, K.

2001-01-01

The full-scale Sector Model Project, which was initiated in 1995 as one of the Large Seven R and D Projects, completed all R and D activities planned in the ITER-EDA period with the joint effort of the ITER Joint Central Team (JCT), the Japanese, the Russian Federation (RF) and the United States (US) Home Teams. The fabrication of a full-scale 18 toroidal sector, which is composed of two 9 sectors spliced at the port center, was successfully completed in September 1997 with the dimensional accuracy of ± 3 mm for the total height and total width. Both sectors were shipped to the test site in JAERI and the integration test was begun in October 1997. The integration test involves the adjustment of field joints, automatic Narrow Gap Tungsten Inert Gas (NG-TIG) welding of field joints with splice plates, and inspection of the joint by ultrasonic testing (UT), which are required for the initial assembly of ITER vacuum vessel. This first demonstration of field joint welding and performance test on the mechanical characteristics were completed in May 1998 and the all results obtained have satisfied the ITER design. In addition to these tests, the integration with the mid plane port extension fabricated by the Russian Home Team, and the cutting and re-welding test of field joints by using full-remotized welding and cutting system developed by the US Home Team, are planned as post EDA activities. (author)

Integration test of ITER full-scale vacuum vessel sector

International Nuclear Information System (INIS)

Nakahira, M.; Koizumi, K.; Oka, K.

1999-01-01

The full-scale Sector Model Project, which was initiated in 1995 as one of the Large Seven ITER R and D Projects, completed all R and D activities planned in the ITER-EDA period with the joint effort of the ITER Joint Central Team (JCT), the Japanese, the Russian Federation (RF) and the United States (US) Home Teams. The fabrication of a full-scale 18 toroidal sector, which is composed of two 9 sectors spliced at the port center, was successfully completed in September 1997 with the dimensional accuracy of - 3 mm for the total height and total width. Both sectors were shipped to the test site in JAERI and the integration test was begun in October 1997. The integration test involves the adjustment of field joints, automatic Narrow Gap Tungsten Inert Gas (NG-TIG) welding of field joints with splice plates, and inspection of the joint by ultrasonic testing (UT), which are required for the initial assembly of ITER vacuum vessel. This first demonstration of field joint welding and performance test on the mechanical characteristics were completed in May 1998 and the all results obtained have satisfied the ITER design. In addition to these tests, the integration with the mid plane port extension fabricated by the Russian Home Team, and the cutting and re-welding test of field joints by using full-remotized welding and cutting system developed by the US Home Team, are planned as post EDA activities. (author)

An optimized one-tube, semi-nested PCR assay for Paracoccidioides brasiliensis detection

Directory of Open Access Journals (Sweden)

Amanda de Faveri Pitz

2013-12-01

Full Text Available Introduction Herein, we report a one-tube, semi-nested-polymerase chain reaction (OTsn-PCR assay for the detection of Paracoccidioides brasiliensis. Methods We developed the OTsn-PCR assay for the detection of P. brasiliensis in clinical specimens and compared it with other PCR methods. Results The OTsn-PCR assay was positive for all clinical samples, and the detection limit was better or equivalent to the other nested or semi-nested PCR methods for P. brasiliensis detection. Conclusions The OTsn-PCR assay described in this paper has a detection limit similar to other reactions for the molecular detection of P. brasiliensis, but this approach is faster and less prone to contamination than other conventional nested or semi-nested PCR assays.

Electric Energy Consumption of the Full Scale Research Biogas Plant “Unterer Lindenhof”: Results of Longterm and Full Detail Measurements

Directory of Open Access Journals (Sweden)

Thomas Jungbluth

2012-12-01

Full Text Available This work thoroughly evaluates the electric power consumption of a full scale, 3 × 923 m3 complete stirred tank reactor (CSTR research biogas plant with a production capacity of 186 kW of electric power. The plant was fed with a mixture of livestock manure and renewable energy crops and was operated under mesophilic conditions. This paper will provide an insight into precise electric energy consumption measurements of a full scale biogas plant over a period of two years. The results showed that a percentage of 8.5% (in 2010 and 8.7% (in 2011 of the produced electric energy was consumed by the combined heat and power unit (CHP, which was required to operate the biogas plant. The consumer unit agitators with 4.3% (in 2010 and 4.0% (in 2011 and CHP unit with 2.5% (in 2010 and 2011 accounted for the highest electrical power demand, in relation to the electric energy produced by the CHP unit. Calculations show that 51% (in 2010 and 46% (in 2011 of the total electric energy demand was due to the agitators. The results finally showed the need for permanent measurements to identify and quantify the electric energy saving potentials of full scale biogas plants.

Controlled formation of Ni(DMG)2 microrods/tubes by manipulating the kinetics of chemical reactions and their application in naked-eye sensors.

Science.gov (United States)

Qin, Jianli; Wang, Bo; Zhang, Xiujuan; Zhang, Xiaohong

2012-08-01

We have demonstrated controlled preparation of Ni(DMG)2 microrods/tubes via chemical reaction method. By manipulating the reaction kinetics via the concentration of reactants, shapes of the resulting microstructures can be easily tuned from microrods to microtubes. Size of the resulting products can also be controlled through changing the reaction temperatures. It was proposed that under high reactants' concentrations, molecules will prefer to grow at corners or edges of nuclei with high free energies, to reduce the total energy in the system, which would lead to partial or complete hollow interiors and eventually resulted in mircotubes. The fact that DMG show high selectivity with Ni2+ and accompanied with obvious color change enable us to fabricate test strip for naked-eye detection of Ni2+. Benefit from the large surface areas of DMG nanoparticles on the test strip, the detection limit is improved by two orders over that of conventional solution method. This strategy is sensitive, simple and easy to handle, thus expected to possess potentials for the practical Ni2+ detection applications.

Identification and control of factors influencing flow-accelerated corrosion in HRSG units using computational fluid dynamics modeling, full-scale air flow testing, and risk analysis

Energy Technology Data Exchange (ETDEWEB)

Pietrowski, Ronald L. [The Consolidated Edison Company of New York, Inc., New York, NY (United States)

2010-11-15

In 2009, Consolidated Edison's East River heat recovery steam generator units 10 and 20 both experienced economizer tube failures which forced each unit offline. Extensive inspections indicated that the primary failure mechanism was flow-accelerated corrosion (FAC). The inspections revealed evidence of active FAC in all 7 of the economizer modules, with the most advanced stages of degradation being noted in center modules. Analysis determined that various factors were influencing and enabling this corrosion mechanism. Computational fluid dynamics and full-scale air flow testing showed very turbulent feedwater flow prevalent in areas of the modules corresponding with the pattern of FAC damage observed through inspection. It also identified preferential flow paths, with higher flow velocities, in certain tubes directly under the inlet nozzles. A FAC risk analysis identified more general susceptibility to FAC in the areas experiencing damage due to feedwater pH, operating temperatures, local shear fluid forces, and the chemical composition of the original materials of construction. These, in combination, were the primary root causes of the failures. Corrective actions were identified, analyzed, and implemented, resulting in equipment replacements and repairs. (orig.)

Implications of the Baltimore Rail Tunnel Fire for Full-Scale Testing of Shipping Casks

International Nuclear Information System (INIS)

Halstead, R. J.; Dilger, F.

2003-01-01

The U.S. Nuclear Regulatory Commission (NRC) does not currently require full-scale physical testing of shipping casks as part of its certification process. Stakeholders have long urged NRC to require full-scale testing as part of certification. NRC is currently preparing a full-scale casktesting proposal as part of the Package Performance Study (PPS) that grew out of the NRC reexamination of the Modal Study. The State of Nevada and Clark County remain committed to the position that demonstration testing would not be an acceptable substitute for a combination of full-scale testing, scale-model tests, and computer simulation of each new cask design prior to certification. Based on previous analyses of cask testing issues, and on preliminary findings regarding the July 2001 Baltimore rail tunnel fire, the authors recommend that NRC prioritize extra-regulatory thermal testing of a large rail cask and the GA-4 truck cask under the PPS. The specific fire conditions and other aspects of the full-scale extra-regulatory tests recommended for the PPS are yet to be determined. NRC, in consultation with stakeholders, must consider past real-world accidents and computer simulations to establish temperature failure thresholds for cask containment and fuel cladding. The cost of extra-regulatory thermal testing is yet to be determined. The minimum cost for regulatory thermal testing of a legal-weight truck cask would likely be $3.3-3.8 million

Application of composite tubes in power plants

International Nuclear Information System (INIS)

Toernblom, H.; Egnell, L.; Gullberg, R.

1975-01-01

Composite tubes with metallurgical bond are now being used on an industrial scale in recovery boilers. Service trials in power plants are viewed and the possibilities to solve fireside corrosion problems in the boiler and superheater sections are discussed. The present and potential future application in nuclear power plants is summarized. A brief presentation of the manufacture and fabrication of composite tubes is made and specific material properties are discussed. Composite tubes are concluded to be an established product and a useful means of meeting conflicting material requirements under severe service conditions. (author)

Modeling of Chemical Reactions in Afterburning for the Reduction of N2O

DEFF Research Database (Denmark)

Gustavsson, Lennart; Glarborg, Peter; Leckner, Bo

1996-01-01

Full scale tests in a 12 MW fluidized bed combustor on reduction of N2O by secondary fuel injection are analyzed in terms a model that involves a detailed reaction mechanism for the gas phase chemistry as well as a description of gas-solid reactions.......Full scale tests in a 12 MW fluidized bed combustor on reduction of N2O by secondary fuel injection are analyzed in terms a model that involves a detailed reaction mechanism for the gas phase chemistry as well as a description of gas-solid reactions....

Fate of pharmaceuticals in full-scale source separated sanitation system

NARCIS (Netherlands)

Butkovskyi, A.; Hernandez Leal, L.; Rijnaarts, H.H.M.; Zeeman, G.

2015-01-01

Removal of 14 pharmaceuticals and 3 of their transformation products was studied in a full-scale source separated sanitation system with separate collection and treatment of black water and grey water. Black water is treated in an up-flow anaerobic sludge blanket (UASB) reactor followed by

Prediction of Full-Scale Propulsion Power using Artificial Neural Networks

DEFF Research Database (Denmark)

Pedersen, Benjamin Pjedsted; Larsen, Jan

2009-01-01

Full scale measurements of the propulsion power, ship speed, wind speed and direction, sea and air temperature from four different loading conditions, together with hind cast data of wind and sea properties; and noon report data has been used to train an Artificial Neural Network for prediction...

Combustion Aerosols from Full-Scale Suspension-Firing of Wood Pellets

DEFF Research Database (Denmark)

Damø, Anne Juul; Wu, Hao; Frandsen, Flemming

2012-01-01

The objectives of the present work were to investigate the aerosol formation mechanisms during full-scale suspension firing of wood, and, to evaluate the effect of coal fly ash addition on the formation of aerosols under different ash load conditions. Tests with suspension firing of 100 % wood...

Development of heat treated Zr-2.5% Nb alloy tubes for pressure tubes

International Nuclear Information System (INIS)

Saibaba, N.; Jha, S.K.; Tonpe, S.

2011-01-01

Zr-2.5% Nb alloy is the candidate material for pressure tubes of Pressurized Heavy Water Reactors (PHWR), and are manufactured in cold working condition while heat treated pressure tubes are used in RBMK and FUGEN type of reactors. The diametral creep of these tubes is the life limiting factor. This paper presents the extensive work carried out for the optimization of process parameters to manufacture heat treated Zr-2.5% Nb pressure tubes. Extensive dilactometry study was carried out to establish the transus temperature for the alloy and the effect of soaking temperature and cooling rate on the microstructure was characterized. On the basis of the study, water quenching (at 883 deg C) in the a b region with 20-25% primary a phase was selected, further cold worked, aged and finally autoclaved. Mechanical properties of the finished tubes were found to be comparable to the cold worked route. Large number of full sized tubes of about 700 - 800 mm long was produced to establish the repeatability. (author)

Full Scale Test of a SSP 34m boxgirder 2

DEFF Research Database (Denmark)

Jensen, Find Mølholt; Branner, Kim; Nielsen, Per Hørlyk

was part of a proof of concept investigation for a patent. The tests were performed at the Blaest test facility in August 2007. The tests are an important part of a research project established in cooperation between Risø National Laboratory for sustainable energy – Technical university of Denmark, SSP......This report presents the setup and result from three static full-scale tests of the reinforced glass fiber/epoxy box girder used in a 34m wind turbine blade. One test was without reinforcement one with cap reinforcement and the final test was with rib reinforcement. The cap reinforcement test......-Technology A/S and Blaest (Blade test centre A/S) and it has been performed as a part of Find Mølholt Jensen’s PhD thesis. This report is the second data report containing the complete test data for the three full-scale tests. This report deals only with the test methods and the obtained results...

Full scale simulations of accidents on spent-nuclear-fuel shipping systems

International Nuclear Information System (INIS)

Yoshimura, H.R.

1978-01-01

In 1977 and 1978, five first-of-a-kind full scale tests of spent-nuclear-fuel shipping systems were conducted at Sandia Laboratories. The objectives of this broad test program were (1) to assess and demonstrate the validity of current analytical and scale modeling techniques for predicting damage in accident conditions by comparing predicted results with actual test results, and (2) to gain quantitative knowledge of extreme accident environments by assessing the response of full scale hardware under actual test conditions. The tests were not intended to validate the present regulatory standards. The spent fuel cask tests fell into the following configurations: crashes of a truck-transport system into a massive concrete barrier (100 and 130 km/h); a grade crossing impact test (130 km/h) involving a locomotive and a stalled tractor-trailer; and a railcar shipping system impact into a massive concrete barrier (130 km/h) followed by fire. In addition to collecting much data on the response of cask transport systems, the program has demonstrated thus far that current analytical and scale modeling techniques are valid approaches for predicting vehicular and cask damage in accident environments. The tests have also shown that the spent casks tested are extremely rugged devices capable of retaining their radioactive contents in very severe accidents

Managing a chest tube and drainage system.

Science.gov (United States)

Durai, Rajaraman; Hoque, Happy; Davies, Tony W

2010-02-01

Intercostal drainage tubes (ie, chest tubes) are inserted to drain the pleural cavity of air, blood, pus, or lymph. The water-seal container connected to the chest tube allows one-way movement of air and liquid from the pleural cavity. The container should not be changed unless it is full, and the chest tube should not be clamped unnecessarily. After a chest tube is inserted, a nurse trained in chest-tube management is responsible for managing the chest tube and drainage system. This entails monitoring the chest-tube position, controlling fluid evacuation, identifying when to change or empty the containers, and caring for the tube and drainage system during patient transport. This article provides an overview of indications, insertion techniques, and management of chest tubes. Copyright 2010 AORN, Inc. Published by Elsevier Inc. All rights reserved.

NEI You Tube Videos: Amblyopia

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Full Text Available ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia NEI Home Contact Us A-Z Site Map NEI on Social Media Information in Spanish (Información en español) Website, ...

Results and analysis of high heat flux tests on a full scale vertical target prototype of ITER divertor

International Nuclear Information System (INIS)

Missirlian, M.; Escourbiac, F.; Schlosser, J.; Durocher, A.; Bobin-Vastra, I.

2004-01-01

After an extensive development program, a Full-Scale Divertor Target prototype (VTFS) manufactured with all the main features of the corresponding ITER divertor, was intensively tested in the high heat flux FE200 facility. The prototype consists of four units having a full mono-block geometry. The lower part (CFC armour) and the upper part (W armour) of each mono-block were joined to the solution annealed, quenched and cold worked CuCrZr tube by HIP technique. The CFC mono-block was successfully tested up to 1000 cycles at 23 MW/m 2 without any indication of failure. This value is well beyond the ITER design target of 300 cycles at 20 MW/m 2 . The W mono-block endured ∼600 cycles at 10 MW/m 2 . This value of flux is one order of magnitude higher than the ITER design target for the upper part of the vertical target. Fatigue damage is observed when pursuing the cycling up to 15 MW/m 2 . A first stress analysis seems to predict these factual results. However, macro-graphic examinations should bring a better damage valuation. Meanwhile, the fatigue testing will continue on the W healthy part of the VTFS prototype with castellation located on the heated surface (reducing the stresses close to the W-Cu interface). (authors)

Results and analysis of high heat flux tests on a full scale vertical target prototype of ITER divertor

Energy Technology Data Exchange (ETDEWEB)

Missirlian, M.; Escourbiac, F.; Schlosser, J.; Durocher, A. [Association Euratom-CEA, Centre d' Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Merola, M. [EFDA Close Support Unit, Garching (Germany); Bobin-Vastra, I. [Framatome, 71 - Le Creusot (France)

2004-07-01

After an extensive development program, a Full-Scale Divertor Target prototype (VTFS) manufactured with all the main features of the corresponding ITER divertor, was intensively tested in the high heat flux FE200 facility. The prototype consists of four units having a full mono-block geometry. The lower part (CFC armour) and the upper part (W armour) of each mono-block were joined to the solution annealed, quenched and cold worked CuCrZr tube by HIP technique. The CFC mono-block was successfully tested up to 1000 cycles at 23 MW/m{sup 2} without any indication of failure. This value is well beyond the ITER design target of 300 cycles at 20 MW/m{sup 2}. The W mono-block endured {approx}600 cycles at 10 MW/m{sup 2}. This value of flux is one order of magnitude higher than the ITER design target for the upper part of the vertical target. Fatigue damage is observed when pursuing the cycling up to 15 MW/m{sup 2}. A first stress analysis seems to predict these factual results. However, macro-graphic examinations should bring a better damage valuation. Meanwhile, the fatigue testing will continue on the W healthy part of the VTFS prototype with castellation located on the heated surface (reducing the stresses close to the W-Cu interface). (authors)

Ammonium detection by formation of colored zebra-bands in a detecting tube.

Science.gov (United States)

Hori, Tatsuaki; Niki, Keizou; Kiso, Yoshiaki; Oguchi, Tatsuo; Kamimoto, Yuki; Yamada, Toshiro; Nagai, Masahiro

2010-06-15

Ammonium ion was colorized by means of a diazo coupling reaction with 2-phenylphenol, where the color development reaction was conducted within 3min by using boric acid as a catalyst. The resulting colored solution (0.5ml) was supplied by suction to a detecting tube consisting of a nonwoven fabric test strip (2mm wide, 1mm thick, 150mm long) impregnated with benzylcetyldimethylammonium chloride in a stripe pattern and enclosed in a heat-shrinkable tube. When the colored solution was supplied to the detecting tube, blue zebra-bands formed, and the ammonium concentration was determined by counting the number of zebra-bands. The detection range was 1-20mg-Nl(-1). Ammonium ion in actual domestic wastewater samples was successfully detected by means of this method.

Manufacturing test of large scale hollow capsule and long length cladding in the large scale oxide dispersion strengthened (ODS) martensitic steel

International Nuclear Information System (INIS)

Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Fujiwara, Masayuki

2004-04-01

Mass production capability of oxide dispersion strengthened (ODS) martensitic steel cladding (9Cr) has being evaluated in the Phase II of the Feasibility Studies on Commercialized Fast Reactor Cycle System. The cost for manufacturing mother tube (raw materials powder production, mechanical alloying (MA) by ball mill, canning, hot extrusion, and machining) is a dominant factor in the total cost for manufacturing ODS ferritic steel cladding. In this study, the large-sale 9Cr-ODS martensitic steel mother tube which is made with a large-scale hollow capsule, and long length claddings were manufactured, and the applicability of these processes was evaluated. Following results were obtained in this study. (1) Manufacturing the large scale mother tube in the dimension of 32 mm OD, 21 mm ID, and 2 m length has been successfully carried out using large scale hollow capsule. This mother tube has a high degree of accuracy in size. (2) The chemical composition and the micro structure of the manufactured mother tube are similar to the existing mother tube manufactured by a small scale can. And the remarkable difference between the bottom and top sides in the manufactured mother tube has not been observed. (3) The long length cladding has been successfully manufactured from the large scale mother tube which was made using a large scale hollow capsule. (4) For reducing the manufacturing cost of the ODS steel claddings, manufacturing process of the mother tubes using a large scale hollow capsules is promising. (author)

Improving the calandria tubes for CANDU reactors

International Nuclear Information System (INIS)

Coleman, C.E.; Fong, R.W.L.; Doubt, G.L.

1997-01-01

CANDU calandria tubes are made from annealed Zircaloy-2 sheet formed into a cylinder and welded along its length to make the tube. The current calandria tubes have given exemplary service for many years. With more stringent regulations and the need to accommodate warm cooling water in tropical countries, we started a development program to increase the margins for failure during postulated accidents. These improvements involve increasing the tube strength and optimising the heat-transfer from an excessively hot fuel channel to the cool moderator. If the postulated accident involves a pressure tube break, it would be desirable if the calandria tube withstood the full pressure of the heat-transport system. The weakest link in current calandria tubes is the weld. Thickening the weld can increase the strength by 20% while seamless tubes can be 45% stronger than current tubes. The latter tubes can hold full system pressure for many hours without failure. If during the postulated accident the fuel and pressure tube become excessively hot but do not touch the calandria tube, the radiant heat loss must be maximised. Current calandria tubes have an absorptivity (emissivity) of about 0.2. To protect the fuel and the fuel channel we have devised a finish to the inside surface of the calandria tube that increases the emissivity to 0.7. If during the postulated accident the hot pressure tube touches the cool calandria tube, the contact conductance and the critical heat flux must be optimised to ensure nucleate boiling of the moderator at the outside surface of the calandria tube and therefore efficient exploitation of the moderator as a heat sink. In laboratory tests small ridges on the inside surface and roughening of the outside surface have been shown to increase the margins against failure and increase the possible moderator temperatures thus providing the opportunity to decrease the cost of the moderator heat-exchange system and remove restrictions on reactor operation in

A selected ion flow tube study of the reactions of H3O+, NO+ and O-2(+center dot) with seven isomers of hexanol in support of SIFT-MS

Czech Academy of Sciences Publication Activity Database

Smith, D.; Sovová, Kristýna; Španěl, Patrik

2012-01-01

Roč. 319, MAY 1 2012 (2012), s. 25-30 ISSN 1387-3806 R&D Projects: GA ČR GA203/09/0256 Institutional support: RVO:61388955 Keywords : selected ion flow tube mass spectrometry * proton transfer * ion molecule reaction Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.142, year: 2012

Detection of pressure tube leaks relying on moisture beetles only

International Nuclear Information System (INIS)

Kenchington, J.M.; Choi, A.; Jin, Y.

2004-01-01

A major decision was made for Pickering NGS A Annulus Gas System (ACS) that detection of a pressure tube (PT) leak should be achieved by using only moisture beetles and that dew point monitors would provide 'early warning' without status to shut down the reactor. Experience with Unit 3 has shown that dew point monitoring of pressure tube leaks was particularly subject to gas leaks and surface adsorption effects. Unit 4 was the first one to be converted during the full scale pressure tube replacement programme. Because of the fundamental change in design philosophy, moisture injection tests were carried out during commissioning to demonstrate that performance matched design. In particular it was necessary to show that leak before break (LBB) would be achieved if a leak occurred in the limiting string. Units 1 and 3 have since been converted. No decision has been taken to convert Pickering B units as gas leaks are small and no significant adsorption effects are anticipated. Hence dew point monitoring will not be impaired. (author)

Management of chest drainage tubes after lung surgery.

Science.gov (United States)

Satoh, Yukitoshi

2016-06-01

Since chest tubes have been routinely used to drain the pleural space, particularly after lung surgery, the management of chest tubes is considered to be essential for the thoracic surgeon. The pleural drainage system requires effective drainage, suction, and water-sealing. Another key point of chest tube management is that a water seal is considered to be superior to suction for most air leaks. Nowadays, the most common pleural drainage device attached to the chest tube is the three-bottle system. An electronic chest drainage system has been developed that is effective in standardizing the postoperative management of chest tubes. More liberal use of digital drainage devices in the postoperative management of the pleural space is warranted. The removal of chest tubes is a common procedure occurring almost daily in hospitals throughout the world. Extraction of the tube is usually done at the end of full inspiration or at the end of full expiration. The tube removal technique is not as important as how it is done and the preparation for the procedure. The management of chest tubes must be based on careful observation, the patient's characteristics, and the operative procedures that had been performed.

Catalytic activity of catalysts for steam reforming reaction. Contract research

Energy Technology Data Exchange (ETDEWEB)

Ohashi, Hirofumi; Inagaki, Yoshiyuki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

2003-05-01

Japan Atomic Energy Research Institute has been developing a hydrogen production system by means of steam reforming of methane (chemical reation: CH{sub 4} + H{sub 2}O = CO + 3H{sub 2}) coupling with High Temperature Engineering Test Reactor (HTTR) to demonstrate effectiveness of high-temperature nuclear heat utilization. Prior to construction of HTTR hydrogen production system, a mock-up test facility with a full-scale reaction tube was constructed to investigate transient behavior of the hydrogen production system an establish system controllability. In order to predict transient behavior and hydrogen productivity of the hydrogen production system, it is important to estimate the reaction characteristics under the same temperature and pressure conditions as those of HTTR hydrogen production system. For the purpose of investigate an apparent activation energy of catalysts, catalytic activity test using small apparatus was carried out under the condition of methane flow rate from 1.18 x 10{sup -3} to 3.19 x 10{sup -3} mol/s, temperature from 500 to 900degC, pressure from 1.1 to 4.1MPa, and mol ratio of steam to methane from 2.5 to 3.5. It was confirmed that apparent activation energies of two kinds of Ni catalysts which are to be used in the mock-up test were 51.7 and 57.4kJ/mol, respectively, and reaction rate constants were propositional to the value from P{sup -0.15} to P{sup -0.33}. (author)

Bench-scale and full-scale studies of nitric oxides reduction by gaseous fuel reburning

International Nuclear Information System (INIS)

Su, S.; Xiang, J.; Sun, L.S.; Hu, S.; Zhu, J.M.

2008-01-01

Nitrogen oxides (NOx) emissions from coal-fired boilers are significant contributors to atmospheric pollution. China has specified more rigorous legal limits for NOx emissions from power plants. As a result of the need to reduce NOx emissions, cost-effective NOx reduction strategies must be explored. This paper presented detailed experimental studies on a gaseous fuel reburning process that was performed in a 36 kilowatt bench-scale down-fired furnace to define the optimal reburning operating conditions when different Chinese coals were fired in the furnace. In addition, the combustion system of a 350 megawatt full-scale boiler was retrofitted according to the experimental results. Finally, the gaseous fuel reburning was applied to the retrofitted full-scale boiler. The purpose of the study was to obtain a better understanding of the influence of the key parameters on nitric oxide (NO) reduction efficiency of the reburning process and demonstrate the gaseous fuel reburning on a 350 MWe coal-fired boiler in China. The paper described the experimental procedure with particular reference to the experimental facility and measurement; a schematic diagram of the experimental system; experimental fuels; and characteristics of coals for the reburning experiments. Results that were presented included influence of reburn zone residence time; influence of gaseous reburn fuel per cent; influence of excess air coefficient; and unburned carbon in fly ash. It was concluded that both an above 50 per cent NO reduction efficiency and low carbon loss can be obtained by the gaseous fuel reburning process under the optimal operating conditions. 20 refs., 5 tabs., 10 figs

SUPECA kinetics for scaling redox reactions in networks of mixed substrates and consumers and an example application to aerobic soil respiration

Science.gov (United States)

Tang, Jin-Yun; Riley, William J.

2017-09-01

Several land biogeochemical models used for studying carbon-climate feedbacks have begun explicitly representing microbial dynamics. However, to our knowledge, there has been no theoretical work on how to achieve a consistent scaling of the complex biogeochemical reactions from microbial individuals to populations, communities, and interactions with plants and mineral soils. We focus here on developing a mathematical formulation of the substrate-consumer relationships for consumer-mediated redox reactions of the form A + BE→ products, where products could be, e.g., microbial biomass or bioproducts. Under the quasi-steady-state approximation, these substrate-consumer relationships can be formulated as the computationally difficult full equilibrium chemistry problem or approximated analytically with the dual Monod (DM) or synthesizing unit (SU) kinetics. We find that DM kinetics is scaling inconsistently for reaction networks because (1) substrate limitations are not considered, (2) contradictory assumptions are made regarding the substrate processing rate when transitioning from single- to multi-substrate redox reactions, and (3) the product generation rate cannot be scaled from one to multiple substrates. In contrast, SU kinetics consistently scales the product generation rate from one to multiple substrates but predicts unrealistic results as consumer abundances reach large values with respect to their substrates. We attribute this deficit to SU's failure to incorporate substrate limitation in its derivation. To address these issues, we propose SUPECA (SU plus the equilibrium chemistry approximation - ECA) kinetics, which consistently imposes substrate and consumer mass balance constraints. We show that SUPECA kinetics satisfies the partition principle, i.e., scaling invariance across a network of an arbitrary number of reactions (e.g., as in Newton's law of motion and Dalton's law of partial pressures). We tested SUPECA kinetics with the equilibrium chemistry

Multiphasic Reaction Modeling for Polypropylene Production in a Pilot-Scale Catalytic Reactor

Directory of Open Access Journals (Sweden)

Mohammad Jakir Hossain Khan

2016-06-01

Full Text Available In this study, a novel multiphasic model for the calculation of the polypropylene production in a complicated hydrodynamic and the physiochemical environments has been formulated, confirmed and validated. This is a first research attempt that describes the development of the dual-phasic phenomena, the impact of the optimal process conditions on the production rate of polypropylene and the fluidized bed dynamic details which could be concurrently obtained after solving the model coupled with the CFD (computational fluid dynamics model, the basic mathematical model and the moment equations. Furthermore, we have established the quantitative relationship between the operational condition and the dynamic gas–solid behavior in actual reaction environments. Our results state that the proposed model could be applied for generalizing the production rate of the polymer from a chemical procedure to pilot-scale chemical reaction engineering. However, it was assumed that the solids present in the bubble phase and the reactant gas present in the emulsion phase improved the multiphasic model, thus taking into account that the polymerization took place mutually in the emulsion besides the bubble phase. It was observed that with respect to the experimental extent of the superficial gas velocity and the Ziegler-Natta feed rate, the ratio of the polymer produced as compared to the overall rate of production was approximately in the range of 9%–11%. This is a significant amount and it should not be ignored. We also carried out the simulation studies for comparing the data of the CFD-dependent dual-phasic model, the emulsion phase model, the dynamic bubble model and the experimental results. It was noted that the improved dual-phasic model and the CFD model were able to predict more constricted and safer windows at similar conditions as compared to the experimental results. Our work is unique, as the integrated developed model is able to offer clearer ideas

Sustainable, Full-Scope Nuclear Fission Energy at Planetary Scale

Directory of Open Access Journals (Sweden)

Robert Petroski

2012-11-01

Full Text Available A nuclear fission-based energy system is described that is capable of supplying the energy needs of all of human civilization for a full range of human energy use scenarios, including both very high rates of energy use and strikingly-large amounts of total energy-utilized. To achieve such “planetary scale sustainability”, this nuclear energy system integrates three nascent technologies: uranium extraction from seawater, manifestly safe breeder reactors, and deep borehole disposal of nuclear waste. In addition to these technological components, it also possesses the sociopolitical quality of manifest safety, which involves engineering to a very high degree of safety in a straightforward manner, while concurrently making the safety characteristics of the resulting nuclear systems continually manifest to society as a whole. Near-term aspects of this nuclear system are outlined, and representative parameters given for a system of global scale capable of supplying energy to a planetary population of 10 billion people at a per capita level enjoyed by contemporary Americans, i.e., of a type which might be seen a half-century hence. In addition to being sustainable from a resource standpoint, the described nuclear system is also sustainable with respect to environmental and human health impacts, including those resulting from severe accidents.

Structural analysis of expandable tubes for oil wells; Analise estrutural de tubos expansiveis para pocos de petroleo

Energy Technology Data Exchange (ETDEWEB)

Aguiar, Ana Carolina Caldas; Antoun Netto, Theodoro [Universidade Federal do Rio de Janeiro (Brazil)], e-mails: carolinaaguiar@lts.coppe.ufrj.br, tanetto@lts.coppe.ufrj.br

2009-06-15

Solid expandable tube technology has many advantages when compared to conventional well bores. The tube expansion in situ assists the development of reservoirs in many challenging scenarios facing the oil industry today, such as in the pre-salt layer, HPHT wells, deep reservoirs, or ultra-deep water. Furthermore, this procedure has good compatibility with directional and horizontal wells and facilitates side-track operations. Although tube expansion is an attractive approach, there is a necessity to better understand its influence on the tube mechanical strength. This study carried out tests and numerical analyses to determine the effect of parameters such as diameter-to-thickness ratio and expansion rate on the collapse resistance of expandable tubes. An experimental apparatus was designed and built to reproduce full-scale tube expansion. Three, 2-meter long specimens were expanded 10% of their original diameters and subjected to hydrostatic pressure inside a vessel until collapse. Three non-expanded tubes were also tested for comparison. At the same time, non-linear numerical models were developed using the finite element method. After calibration, they were used to further analyze the mechanical behavior of solid expandable tubes and the influence of expansion on their resistance to collapse. (author)

Testing of a 7-tube palladium membrane reactor for potential use in TEP

International Nuclear Information System (INIS)

Carlson, Bryan J.; Trujillo, Stephen; Willms, R. Scott

2010-01-01

A Palladium Membrane Reactor (PMR) consists of a palladium/silver membrane permeator filled with catalyst (catalyst may be inside or outside the membrane tubes). The PMR is designed to recover tritium from the methane, water, and other impurities present in fusion reactor effluent. A key feature of a PMR is that the total hydrogen isotope content of a stream is significantly reduced as (1) methane-steam reforming and/or water-gas shift reactions proceed on the catalyst bed and (2) hydrogen isotopes are removed via permeation through the membrane. With a PMR design matched to processing requirements, nearly complete hydrogen isotope removals can be achieved. A 3-tube PMR study was recently completed. From the results presented in this study, it was possible to conclude that a PMR is appropriate for TEP, perforated metal tube protectors function well, platinum on aluminum (PtA) catalyst performs the best, conditioning with air is probably required to properly condition the Pd/Ag tubes, and that CO/CO 2 ratios maybe an indicator of coking. The 3-tube PMR had a permeator membrane area of 0.0247 m 2 and a catalyst volume to membrane area ratio of 4.63 cc/cm 2 (with the catalyst on the outside of the membrane tubes and the catalyst only covering the membrane tube length). A PMR for TEP will require a larger membrane area (perhaps 0.35 m 2 ). With this in mind, an intermediate sized PMR was constructed. This PMR has 7 permeator tubes and a total membrane area of 0.0851 m 2 . The catalyst volume to membrane area ratio for the 7-tube PMR was 5.18 cc/cm 2 . The total membrane area of the 7-tube PMR (0.0851 m 2 ) is 3.45 times larger than total membrane area of the 3-tube PMR (0.0247 m 2 ). The following objectives were identified for the 7-tube PMR tests: (1) Refine test measurements, especially humidity and flow; (2) Refine maintenance procedures for Pd/Ag tube conditioning; (3) Evaluate baseline PMR operating conditions; (4) Determine PMR scaling method; (5) Evaluate PMR

Tests on full-scale prototypical passive containment condenser for SBWR's application

International Nuclear Information System (INIS)

Masoni, P.; Bianchini, G.; Billig, P.F.; Fitch, J.R.; Botti, S.; Cattadori, G.; Silverii, R.

1995-01-01

The paper gives a brief description of the experimental program Performance ANalysis and Testing of HEat Removal Systems (PANTHERS) aimed to demonstrate the thermal-hydraulic and structural performance of a full scale prototype of the Passive Containment Cooling (PCC) heat exchanger. Preliminary results of the experimental tests are given. These results show the thermal-hydraulic performance of the heat exchanger as a function of inlet pressure and of the air mass fraction for some steady-state performance tests and for a test in which the water level in the PCC pool is allowed to drop and the PCC tubes to uncover and for a test with non-condensable build-up. The experimental results are very positive and show a very good repeatability. The structural design of the heat exchanger is very robust: the unit has survived ten loss-of-coolant accident (LOCA) cycles and more than 100 thermal-hydraulic performance tests. A detailed GE proprietary version of the Transient Reactor Analysis Code (TRACG) model of the PANTHERS tests facility was developed and verified solely on the basis of as-designed test facility drawings and engineering judgement. No PANTHERS test data, including shakedown data, was used to guide the development of this model. Using the PANTHERS TRACG model, pre-test calculations of Tests No.15-1 and 23-1 from the Test group 3 of the PANTHERS test matrix were made. The key results from these calculations have been documented in this paper. For comparison, a second set of calculations was made using the simplified PCC representation from the SBWR containment TRACG input model used for containment performance evaluations. The results from the simplified model have been compared with those from the detailed PANTHERS model and with those from the tests; the reasons for the observed differences have been discussed. Given the limitation in the double-blind pre-test calculations, the results are very satisfying for both the heat removal and the total pressure drop

Full scale testing for investigation of wind turbine seismic response

Energy Technology Data Exchange (ETDEWEB)

Prowell, I.; Veletzos, M.; Elgamal, A. [California Univ., San Diego, CA (United States). Dept. of Structural Engineering

2008-07-01

In 2007, much of the growth in wind energy development was concentrated in North America and Asia, two regions which periodically experience strong earthquakes that may impact the final turbine design. As such, rational prediction of seismic hazards must be considered in order to maintain and enhance the ability of wind power to compete economically with other energy sources. In response to this challenge, researchers at the University of California, San Diego (UCSD) have experimentally investigated wind turbines to gain an understanding of expected earthquake forces. This paper described the experimental setup for a full scale shake table test of a 65 kW wind turbine. The turbine was excited perpendicular to the axis of the rotor with a seismic base shaking record scaled to various levels. The data was analyzed using simple but effective procedures to provide insight into the observed structural damping of the wind turbine. The experimental investigation showed that full scale seismic testing of wind turbines is possible and can provide valuable insight into dynamic behaviour of wind turbines. The results can be used to develop a more accurate picture of how wind turbines are impacted by earthquakes. The data regarding the low observed super-structure damping provides a basis for calibration and further development of verified design procedures. 20 refs., 3 tabs.

Full-color large-scaled computer-generated holograms using RGB color filters.

Science.gov (United States)

Tsuchiyama, Yasuhiro; Matsushima, Kyoji

2017-02-06

A technique using RGB color filters is proposed for creating high-quality full-color computer-generated holograms (CGHs). The fringe of these CGHs is composed of more than a billion pixels. The CGHs reconstruct full-parallax three-dimensional color images with a deep sensation of depth caused by natural motion parallax. The simulation technique as well as the principle and challenges of high-quality full-color reconstruction are presented to address the design of filter properties suitable for large-scaled CGHs. Optical reconstructions of actual fabricated full-color CGHs are demonstrated in order to verify the proposed techniques.

Full-scale Applications of Membrane Filtration in Municipal Wastewater Treatment Plants

Czech Academy of Sciences Publication Activity Database

Holba, Marek; Plotěný, K.; Dvořák, L.; Gómez, M.; Růžičková, I.

2012-01-01

Roč. 40, č. 5 (2012), s. 479-486 ISSN 1863-0650 Institutional support: RVO:67985939 Keywords : membrane bioreactors * wastewater treatment * full-scale application Subject RIV: EF - Botanics Impact factor: 2.046, year: 2012

Sustainable, Full-Scope Nuclear Fission Energy at Planetary Scale

OpenAIRE

Robert Petroski; Lowell Wood

2012-01-01

A nuclear fission-based energy system is described that is capable of supplying the energy needs of all of human civilization for a full range of human energy use scenarios, including both very high rates of energy use and strikingly-large amounts of total energy-utilized. To achieve such “planetary scale sustainability”, this nuclear energy system integrates three nascent technologies: uranium extraction from seawater, manifestly safe breeder reactors, and deep borehole d...

Bradycardia after Tube Thoracostomy for Spontaneous Pneumothorax

Directory of Open Access Journals (Sweden)

Yomi Fashola

2018-01-01

Full Text Available We present the case of an elderly patient who became bradycardic after chest tube insertion for spontaneous pneumothorax. Arrhythmia is a rare complication of tube thoracostomy. Unlike other reported cases of chest tube induced arrhythmias, the bradycardia in our patient responded to resuscitative measures without removal or repositioning of the tube. Our patient, who had COPD, presented with shortness of breath due to spontaneous pneumothorax. Moments after tube insertion, patient developed severe bradycardia that responded to Atropine. In patients requiring chest tube insertion, it is important to be prepared to provide cardiopulmonary resuscitative therapy in case the patient develops a life-threatening arrhythmia.

Full Kinetics from First Principles of the Chlorine Evolution Reaction over a RuO2 (110) Model Electrode.

Science.gov (United States)

Exner, Kai S; Anton, Josef; Jacob, Timo; Over, Herbert

2016-06-20

Current progress in modern electrocatalysis research is spurred by theory, frequently based on ab initio thermodynamics, where the stable reaction intermediates at the electrode surface are identified, while the actual energy barriers are ignored. This approach is popular in that a simple tool is available for searching for promising electrode materials. However, thermodynamics alone may be misleading to assess the catalytic activity of an electrochemical reaction as we exemplify with the chlorine evolution reaction (CER) over a RuO2 (110) model electrode. The full procedure is introduced, starting from the stable reaction intermediates, computing the energy barriers, and finally performing microkinetic simulations, all performed under the influence of the solvent and the electrode potential. Full kinetics from first-principles allows the rate-determining step in the CER to be identified and the experimentally observed change in the Tafel slope to be explained. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fluoroscopically-guided transnasal insertion of ileus tube intestinal decompression in patients with inoperable malignant bowel obstruction

International Nuclear Information System (INIS)

Fang Shiming; Li Haili; Lin Qing; Mao Aiwu; Wu Shaoqiu; Jiang Haosheng; Cao Yan; Wang Zhenlei

2011-01-01

Objective: To assess the technical feasibility and effectiveness of fluoroscopically-guided transnasal insertion of ileus tube for intestinal decompression in the treatment of inoperable malignant bowel obstruction. Methods: A total of 211 patients with inoperable malignant bowel obstruction were enrolled in this study. The median KPS scale was 40 (ranged from 20 to 60). Under fluoroscopic guidance, transnasal insertion of ileus tube by using conventional technique or guidewire-catheter exchange technique was performed in all patients. The technical success rate, the clinical effective rate, the curative rate and adverse reactions as well as complications were documented. The correlation among the obstructive sites, obstruction causes and therapeutic effectiveness was analyzed. The ileus tube used in this study was a four-cavity and double-balloon catheter with a diameter of 16 F/18 f, which is produced by Cliny Company. Results: Transnasal drainage tube was successfully inserted into the proximal jejunum in all 211 patients with malignant bowel obstruction, and the total technical success rate was 100%. The initial technical success rate of the traditional technique and the catheter-guidewire exchange method was 85.5% (65/76) and 100% (135/135) respectively, the difference between the two was significant (P<0.05). After 24 hours, the clinical remission rate in the patients with high-level intestinal obstruction, lower-level intestinal obstruction and colorectal obstruction was 95.8% (46/48), 92.9% (117/126) and 83.8% (31/37), respectively. A follow-up of 4-245 days (mean 138 days) was conducted, and the total clinical cure rate was 27.5% (58/211). The clinical cure rate in small intestine obstruction and colorectal obstruction caused by primary tumor or recurrence was 12.7% (20/157) and 59.5% (22/37), respectively (P<0.05). The adverse reactions and complications included uncomfortable pharynx feeling or pain (99.1%, 199/221), the tube obstruction (23.2%, 49

Synthesis of barium-strontium titanate hollow tubes using Kirkendall effect

Science.gov (United States)

Chen, Xuncai; Im, SangHyuk; Kim, Jinsoo; Kim, Woo-Sik

2018-02-01

(BaSr)TiO3 hexagonal hollow tubes was fabricated by a solid-state interfacial reaction including a Kirkendall diffusion. Using a co-precipitation and sol-gel process, a core@shell structure of (BaSr)CO3@TiO2 rods were prepared, and then converted to (BaSr)TiO3 hollow tubes at 750 °C. This was a first achievement of single-phase crystal hollow tube. Here, the inner diameter and wall thickness of hollow tube were about 700 nm and 130 nm, respectively. The fabrication of (BaSr)TiO3 hollow tubes was monitored with scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD) to investigate their formation mechanism. The present synthetic approach would provide a new insight into the design and fabrication of hollow architectures of many perovskite oxides.

Safety Performance Evaluations for the Vehicle Based Movable Barriers Using Full Scale Crash Tests

Directory of Open Access Journals (Sweden)

Jin Minsoo

2017-01-01

Full Text Available The present study aims to develop a prototype of large-size movable barriers to protect roadside workers from incoming vehicles to the road work area with the following functions: maximization of work space in the right and left directions, convenient mobility, and minimization of impact without modification of the inside of movable barriers into traffic lanes and perform safety performance assessment on passengers through full scale crash tests. The large movable barrier was divided into folder type and telescope type and the development stage was now at the prototype phase. A full scale crash test was conducted prior to certification test at a level of 90%. The full scale crash test result showed that both types of folder type movable barrier and telescope type movable barrier satisfied the standard of the passenger safety performance evaluation at a level of 90%.

Disposal of Draeger Tubes at Savannah River Site

International Nuclear Information System (INIS)

Malik, N.P.

2000-01-01

The Savannah River Site (SRS) is a Department of Energy (DOE) facility located in Aiken, South Carolina that is operated by the Westinghouse Savannah River Company (WSRC). At SRS Draeger tubes are used to identify the amount and type of a particular chemical constituent in the atmosphere. Draeger tubes rely on a chemical reaction to identify the nature and type of a particular chemical constituent in the atmosphere. Disposal practices for these tubes were identified by performing a hazardous waste evaluation per the Resource Conservation and Recovery Act (RCRA). Additional investigations were conducted to provide guidance for their safe handling, storage and disposal. A list of Draeger tubes commonly used at SRS was first evaluated to determine if they contained any material that could render them as a RCRA hazardous waste. Disposal techniques for Draeger tubes that contained any of the toxic contaminants listed in South Carolina Hazardous Waste Management Regulations (SCHWMR) R.61-79. 261.24 (b) and/or contained an acid in the liquid form were addressed

Ancillary Frequency Control of Direct Drive Full-Scale Converter Based Wind Power Plants

DEFF Research Database (Denmark)

Hu, Weihao; Su, Chi; Fang, Jiakun

2013-01-01

This paper presents a simulation model of a wind power plant based on a MW-level variable speed wind turbine with a full-scale back-to-back power converter developed in the simulation tool of DIgSILENT Power Factory. Three different kinds of ancillary frequency control strategies, namely inertia...... control strategies are effective means for providing ancillary frequency control of variable speed wind turbines with full-scale back-to-back power converters....... emulation, primary frequency control and secondary frequency control, are proposed in order to improve the frequency stability of power systems. The modified IEEE 39-bus test system with a large-scale wind power penetration is chosen as the studied power system. Simulation results show that the proposed...

Design features of a full-scale high-level waste vitrification system

International Nuclear Information System (INIS)

Siemens, D.H.; Bonner, W.F.

1976-08-01

A system has been designed and is currently under construction for vitrification of commercial high-level waste. The process consists of a spray calciner coupled to an in-can melter. Due to the high radiation levels expected, this equipment is designed for totally remote operation and maintenance. The in-cell arrangement of this equipment has been developed cooperatively with a nuclear fuel reprocessor. The system will be demonstrated both full scale with nonradioactive simulated waste and pilot scale with actual high-level waste

Optimal Design and Model Validation for Combustion Experiments in a Shock Tube

KAUST Repository

Long, Quan; Kim, Daesang; Tempone, Raul; Bisetti, Fabrizio; Farooq, Aamir; Knio, Omar; Prudhomme, Serge

2014-01-01

in the reaction rate functions. The control parameters are the initial hydrogen concentration and the temperature. First, we build a polynomial based surrogate model for the observable related to the reactions in the shock tube. Second, we use a novel MAP based

Full-scale and laboratory-scale anaerobic treatment of citric acid production wastewater.

Science.gov (United States)

Colleran, E; Pender, S; Philpott, U; O'Flaherty, V; Leahy, B

1998-01-01

This paper reviews the operation of a full-scale, fixed-bed digester treating a citric acid production wastewater with a COD:sulphate ratio of 3-4:1. Support matrix pieces were removed from the digester at intervals during the first 5 years of operation in order to quantify the vertical distribution of biomass within the digester. Detailed analysis of the digester biomass after 5 years of operation indicated that H2 and propionate-utilising SRB had outcompeted hydrogenophilic methanogens and propionate syntrophs. Acetoclastic methanogens were shown to play the dominant role in acetate conversion. Butyrate and ethanol-degrading syntrophs also remained active in the digester after 5 years of operation. Laboratory-scale hybrid reactor treatment at 55 degrees C of a diluted molasses influent, with and without sulphate supplementation, showed that the reactors could be operated with high stability at volumetric loading rates of 24 kgCOD.m-3.d-1 (12 h HRT). In the presence of sulphate (2 g/l-1; COD/sulphate ratio of 6:1), acetate conversion was severely inhibited, resulting in effluent acetate concentrations of up to 4000 mg.l-1.

Development of Full-Scale Ultrathin Shell Reflector

Directory of Open Access Journals (Sweden)

Durmuş Türkmen

2012-01-01

Full Text Available It is aimed that a new ultrathin shell composite reflector is developed considering different design options to optimize the stiffness/mass ratio, cost, and manufacturing. The reflector is an offset parabolic reflector with a diameter of 6 m, a focal length of 4.8 m, and an offset of 0.3 m and has the ability of folding and self-deploying. For Ku-band missions a full-scale offset parabolic reflector antenna is designed by considering different concepts of stiffening: (i reflective surface and skirt, (ii reflective surface and radial ribs, and (iii reflective surface, skirt, and radial ribs. In a preliminary study, the options are modeled using ABAQUS finite element program and compared with respect to their mass, fundamental frequency, and thermal surface errors. It is found that the option of reflective surface and skirt is more advantageous. The option is further analyzed to optimize the stiffness/mass ratio considering the design parameters of material thickness, width of the skirt, and ply angles. Using the TOPSIS method is determined the best reflector concept among thirty different designs. Accordingly, new design can be said to have some advantages in terms of mass, natural frequency, number of parts, production, and assembly than both SSBR and AstroMesh reflectors.

Energy balance and flow in steam generator part with sodium-water reaction

International Nuclear Information System (INIS)

Matal, O.

1980-01-01

Relations were derived for the calculation of heat liberated during the sodium water reaction in a tube failure in different parts of a steam generator. The results are graphically shown in i-T diagrams. Heat removal is described from the reaction zone to water and steam in undisturbed tubes and to the steam generator metal structure. (author)

New Resolution Strategy for Multi-scale Reaction Waves using Time Operator Splitting and Space Adaptive Multiresolution: Application to Human Ischemic Stroke*

Directory of Open Access Journals (Sweden)

Louvet Violaine

2011-12-01

Full Text Available We tackle the numerical simulation of reaction-diffusion equations modeling multi-scale reaction waves. This type of problems induces peculiar difficulties and potentially large stiffness which stem from the broad spectrum of temporal scales in the nonlinear chemical source term as well as from the presence of large spatial gradients in the reactive fronts, spatially very localized. A new resolution strategy was recently introduced ? that combines a performing time operator splitting with high oder dedicated time integration methods and space adaptive multiresolution. Based on recent theoretical studies of numerical analysis, such a strategy leads to a splitting time step which is not restricted neither by the fastest scales in the source term nor by stability limits related to the diffusion problem, but only by the physics of the phenomenon. In this paper, the efficiency of the method is evaluated through 2D and 3D numerical simulations of a human ischemic stroke model, conducted on a simplified brain geometry, for which a simple parallelization strategy for shared memory architectures was implemented, in order to reduce computing costs related to “detailed chemistry” features of the model.

The NET articulated boom: Preliminary investigations and justification for a full scale prototype

International Nuclear Information System (INIS)

Suppan, A.

1990-12-01

The articulated boom system is the favourite in-vessel handling system for NET which will be used to maintain or replace in-vessel components during short term interventions. The testbed EDITH is the prototype of this system and is the logical step between the proof of principle of the system, which is already performed by the JET articulated boom, and the operational equipment for NET. EDITH is required to demonstrate that maintenance of plasma facing components can be carried out with the anticipated reliability and time. To achieve this aim EDITH is based on the experience of the JET boom and will be constructed in full scale, supplemented by a full scale mock-up. A further goal of EDITH is to allow the testing of boom components and subassemblies. The results of preliminary investigations for the boom are summarized, the need of the testbed EDITH and a full scale mock-up is discussed and both EDITH and the mock-up are described. (orig.) [de

Possible first occurrence of external corrosion on alloy 600TT tubes in France

International Nuclear Information System (INIS)

Boccanfuso, M.; Thebault, Y.; Massini, B.; Bigne, L.

2015-01-01

During the last decade, in different countries, several occurrences of external corrosion have been identified on steam generator (SG) tube bundles equipped with thermally treated 600 alloy. In France, this feedback leads EDF to enhance the SG inspection program. Nevertheless, until now, no damage of this type was reported. Recently, during in-service inspection at the Cattenom plant on a SG equipped with alloy 600TT tubes, Eddy current tests have highlighted a signal that could be related to external corrosion. The tube was removed and sent to the EDF hot laboratory for destructive examinations. Various exams were performed at different scales to characterize the causes of this NDT signal, the material properties and the residual stresses. The assessments carried out on the tube conclude that the source of the damage is external intergranular stress corrosion cracking, also called ODSCC (Outside Diameter Stress Corrosion Cracking) making it the first occurrence on the tube bundles made of alloy 600TT in the French fleet. This first case of 600 TT ODSCC in France is an unexpected and particular one, because of its altitude in the full mechanical rolling area. This is reinforced by the low number of occurrences noted to date (only one after nearly 30 years of operation of alloy 600TT tube bundles). International (Biblis) OPEX had identified recent IGSCC with cracks initiated and propagated in the tubesheet. For this case, the scenario considered requires highly restrictive conditions (tube in the sludge zone and on the periphery of the tube bundle, including the tube lane) and may explain the singular nature of the Cattenom tube

Laboratory measurement of secondary pollutant yields from ozone reaction with HVAC filters

International Nuclear Information System (INIS)

Destaillats, Hugo; Chen, Wenhao; Apte, Michael; Li, Nuan; Spears, Michael; Almosni, Jeremie; Zhang, Jianshun Jensen; Fisk, William J.

2009-01-01

We used Proton Transfer Reaction - Mass Spectrometry (PTR-MS) and conventional sampling methods to monitor and identify trace level organic pollutants formed in heterogeneous reactions between ozone and HVAC filters in real time. Experiments were carried out using a bench-scale flow tube reactor operating with dry air and humidified air (50% RH), at realistically high ozone concentrations (150 ppbv). We explored different filter media (i.e., fiberglass and cotton/polyester blends) and different particle loadings (i.e., clean filter and filters loaded with particles for 3 months at the Lawrence Berkeley National Laboratory and the Port of Oakland, CA). Detailed emission dynamics of very low levels of certain organic pollutants from filter media upon ozone exposure in the presence of moisture have been obtained and analyzed.

Full-Scale Approximations of Spatio-Temporal Covariance Models for Large Datasets

KAUST Repository

Zhang, Bohai; Sang, Huiyan; Huang, Jianhua Z.

2014-01-01

of dataset and application of such models is not feasible for large datasets. This article extends the full-scale approximation (FSA) approach by Sang and Huang (2012) to the spatio-temporal context to reduce computational complexity. A reversible jump Markov

To address surface reaction network complexity using scaling relations machine learning and DFT calculations

International Nuclear Information System (INIS)

Ulissi, Zachary W.; Medford, Andrew J.; Bligaard, Thomas; Nørskov, Jens K.

2017-01-01

Surface reaction networks involving hydrocarbons exhibit enormous complexity with thousands of species and reactions for all but the very simplest of chemistries. We present a framework for optimization under uncertainty for heterogeneous catalysis reaction networks using surrogate models that are trained on the fly. The surrogate model is constructed by teaching a Gaussian process adsorption energies based on group additivity fingerprints, combined with transition-state scaling relations and a simple classifier for determining the rate-limiting step. The surrogate model is iteratively used to predict the most important reaction step to be calculated explicitly with computationally demanding electronic structure theory. Applying these methods to the reaction of syngas on rhodium(111), we identify the most likely reaction mechanism. Lastly, propagating uncertainty throughout this process yields the likelihood that the final mechanism is complete given measurements on only a subset of the entire network and uncertainty in the underlying density functional theory calculations.

Isolated Fallopian Tube Torsion in Adolescents

Directory of Open Access Journals (Sweden)

S. Rajaram

2013-01-01

Full Text Available Background. Fallopian tube torsion is a rare cause of acute abdomen, occurring commonly in females of reproductive age. It lacks pathognomonic symptoms, signs, or imaging features, thus causing delay in surgical intervention. Case. We report two cases of isolated fallopian tube torsion in adolescent girls. In the first case a 19-year-old patient presented with acute pain in the left iliac region associated with episodes of vomiting for one day and mild tenderness on examination. Laparoscopy revealed left sided twisted fallopian tube associated with hemorrhagic cyst of ovary. The tube was untwisted and salvaged. In another case an 18-year-old virgin girl presented with similar complaints since one week, associated with mild tenderness in the lower abdomen and tender cystic mass on per rectal examination. On laparoscopy right twisted fallopian tube associated with a paratubal cyst was found. Salpingectomy was done as the tube was gangrenous. Conclusion. Fallopian tube torsion, though rare, should be considered in women of reproductive age with unilateral pelvic pain. Early diagnostic laparoscopy is important for an accurate diagnosis and could salvage the tube.

Test and evaluation of the BBC CQK 200-4 modulator tube for the MFTF sustaining neutral beam power supply system

International Nuclear Information System (INIS)

Eckard, R.D.; Van Ness, H.W.; Hesselgrave, D.

1979-01-01

The BBC CQK 200-4 Tube was tested by Aydin at LLL, to confirm that it would switch 90 kV after conducting 88 amperes for 30 seconds. The CQK 200-4 is a recent modification of the CQK 200-3, an Rf transmitter tube designed for continuous loading, to increase the anode hold-off voltage to 150 kV. During the design life of the tube it will be subjected to 10 5 to 10 6 cyclic thermal loads. Two concerns are that (1) during the 30 second high current load, the screen grid may have excessive dissipation causing a loss of control of the tube, and (2) the cyclic temperature-induced stresses in the anode may cause fatigue failures that will reduce the tube's useful life. The first concern was addressed by performing full scale tests at the LLL test facility

The development and application of overheating failure model of FBR steam generator tubes. 3

International Nuclear Information System (INIS)

Miyake, Osamu; Hamada, Hirotsugu; Tanabe, Hiromi; Wada, Yusaku; Miyakawa, Akira; Okabe, Ayao; Nakai, Ryodai; Hiroi, Hiroshi

2002-03-01

The model has been developed for the assessment of the overheating tube failure in an event of sodium-water reaction accident of fast breeder reactor's steam generators (SGs). The model has been applied to the Monju SG studies. Major results obtained in the studies are as follows: 1. To evaluate the structural integrity of tube material, the strength standard for 2. 25Cr-1Mo steel was established taking account of time dependent effect based on the high temperature (700-1200degC) creep data. This standard has been validated with the tube rupture simulation test data. 2. The conditions for overheating by the high temperature reaction were determined by use of the SWAT-3 experimental data. The realistic local heating conditions (reaction zone temperature and related heat transfer conditions) for the sodium-water reaction were proposed as the cosine-shaped temperature profile. 3. For the cooling effects inside of target tubes, LWR's studies of critical heat flux (CHF) and post-CHF heat transfer correlations have been examined and considered in the model. 4. The model has been validated with experimental data obtained by SWAT-3 and LLTR. The results were satisfactory with conservatism. The PFR superheater leak event in 1987 was studied, and the cause of event and the effectiveness of the improvement after the leak event could be identified by the analysis. 5. The model has been applied to the Monju SG studies. It is revealed consequently that no tube failure occurs in 100%, 40%, and 10% water flow operating conditions when an initial leak is detected by the cover gas pressure detection system. (author)

The use of radiologically placed gastroctomy tubes in head and neck cancer patients receiving radiotherapy

International Nuclear Information System (INIS)

Tyldesley, Scott; Sheehan, Finbarr; Munk, Peter; Tsang, Victor; Skarsgard, David; Bowman, Carol A.; Hobenshield, Shirley E.

1996-01-01

Purpose: Patients undergoing radiotherapy to the head and neck area frequently experience radiation reactions that can markedly restrict oral intake, require hospitalization, and occasionally cause treatment interruptions. The Vancouver Cancer Center (VCC) has recently employed radiologically placed gastrostomy tubes (G-tubes) in the management of this problem. A review of the patients on whom this procedure had been performed is the subject of this review. Methods and Materials: Thirty-four patients had gastrostomy tubes inserted under radiologic guidance. This group is compared to a control group matched for age, sex, irradiated volume, and radiation dose, who did not have gastrostomy tubes. Patients with gastrostomy tubes were divided into two categories: (a) patients who had tubes inserted in anticipation of severe reactions, and (b) patients who developed severe radiation reactions necessitating nutritional support. Results: The gastrostomy group consisted of 65% males with an average age of 59 years and stage range of II (12%), III (24%), and IV (65%). In both the elective group and the nonelective group, patients maintained their weight at 95 to 97% of the pretreatment weight, at follow-up of 6 weeks and 3 months. This compared with an average weight loss in the control group of 9% at 6 weeks and 12% at 3 months. The length of hospitalization was a mean of 4.9 days in the elective group and 19 days in the nonelective group. Complication were low compared to those documented in the literature, but included two tube migrations, two aspirations, and one gastrointestinal bleed. Conclusions: We believe that gastrostomy tubes contribute significantly to the management of patients with head and neck cancer, particularly in maintenance of nutrition, and they may decrease the need for hospitalization

Acorn: A grid computing system for constraint based modeling and visualization of the genome scale metabolic reaction networks via a web interface

Directory of Open Access Journals (Sweden)

Bushell Michael E

2011-05-01

Full Text Available Abstract Background Constraint-based approaches facilitate the prediction of cellular metabolic capabilities, based, in turn on predictions of the repertoire of enzymes encoded in the genome. Recently, genome annotations have been used to reconstruct genome scale metabolic reaction networks for numerous species, including Homo sapiens, which allow simulations that provide valuable insights into topics, including predictions of gene essentiality of pathogens, interpretation of genetic polymorphism in metabolic disease syndromes and suggestions for novel approaches to microbial metabolic engineering. These constraint-based simulations are being integrated with the functional genomics portals, an activity that requires efficient implementation of the constraint-based simulations in the web-based environment. Results Here, we present Acorn, an open source (GNU GPL grid computing system for constraint-based simulations of genome scale metabolic reaction networks within an interactive web environment. The grid-based architecture allows efficient execution of computationally intensive, iterative protocols such as Flux Variability Analysis, which can be readily scaled up as the numbers of models (and users increase. The web interface uses AJAX, which facilitates efficient model browsing and other search functions, and intuitive implementation of appropriate simulation conditions. Research groups can install Acorn locally and create user accounts. Users can also import models in the familiar SBML format and link reaction formulas to major functional genomics portals of choice. Selected models and simulation results can be shared between different users and made publically available. Users can construct pathway map layouts and import them into the server using a desktop editor integrated within the system. Pathway maps are then used to visualise numerical results within the web environment. To illustrate these features we have deployed Acorn and created a

DEVELOPMENT OF COILED TUBING STRESS ANALYSIS

Directory of Open Access Journals (Sweden)

Davorin Matanović

1998-12-01

Full Text Available The use of coiled tubing is increasing rapidly with drilling of horizontal wells. To satisfy all requirements (larger mechanical stresses, larger fluid capacities the production of larger sizes and better material qualities was developed. Stresses due to axial forces and pressures that coiled tubing is subjected are close to its performance limits. So it is really important to know and understand the behaviour of coiled tubing to avoid its break, burst or collapse in the well.

Tubes, Mono Jets, Squeeze Out and CME

Energy Technology Data Exchange (ETDEWEB)

Longacre, R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2017-10-23

Glasma Flux Tubes, Mono Jets with squeeze out flow around them plus the Chiral Magnetic Effect(CME) are physical phenomenon that generate two particle correlation with respect to the reaction plane in mid-central 20% to 30% Au-Au collision √sNN = 200.0 GeV measured at RHIC.

Progress of ITER full tungsten divertor technology qualification in Japan: Manufacturing full-scale plasma-facing unit prototypes

International Nuclear Information System (INIS)

Ezato, Koichiro; Suzuki, Satoshi; Seki, Yohji; Yamada, Hirokazu; Hirayama, Tomoyuki; Yokoyama, Kenji; Escourbiac, Frederic; Hirai, Takeshi

2016-01-01

Highlights: • JADA has demonstrated the feasibility of manufacturing the full-W plasma-facing units (W-PFU). • The surface profiles of the W monoblocks of the W-PFU prototypes on the test frame to mimic the support structure of the ITER OVT were examined by using an optical three-dimensional measurement system. The results show the most W monoblock surface in the target part locates within + 0.25 mm from the CAD data. • The strict profile control with the profile tolerance of ±0.3 mm is imposed on the OVT to prevent the leading edges of the W monoblocks from over-heating. • The present full-scale prototyping demonstrates to satisfy this requirement on the surface profile. • It can be concluded that the technical maturities of JADA and its suppliers are as high as to start series manufacturing the ITER divertor components. - Abstract: Japan Atomic Energy Agency (JAEA) is in progress for technology demonstration toward Full-tungsten (W) ITER divertor outer vertical target (OVT), especially, W monoblock technology that needs to withstand the repetitive heat load as high as 20 MW/m 2 for 10 s. Under the framework of the W divertor qualification program developed ITER organization, JAEA as Japanese Domestic Agency (JADA) manufactured seven full-scale plasma-facing unit (PFU) prototypes with the Japanese industries. Four prototypes that have 146 W monoblock joint with casted copper (Cu) interlayer passed successfully the ultrasonic testing. In the other three prototypes that have the different W/Cu interlayer joint, joint defects were found. The dimension measurements reveal the requirements of the gap between W monoblocks and the surface profile of PFU are feasible.

Progress of ITER full tungsten divertor technology qualification in Japan: Manufacturing full-scale plasma-facing unit prototypes

Energy Technology Data Exchange (ETDEWEB)

Ezato, Koichiro, E-mail: ezato.koichiro@jaea.go.jp [Department of ITER Project, Naka Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency (Japan); Suzuki, Satoshi; Seki, Yohji; Yamada, Hirokazu; Hirayama, Tomoyuki; Yokoyama, Kenji [Department of ITER Project, Naka Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency (Japan); Escourbiac, Frederic; Hirai, Takeshi [ITER Organization, route de vinon sur Verdon, 13067 St Paul lez Durance (France)

2016-11-01

Highlights: • JADA has demonstrated the feasibility of manufacturing the full-W plasma-facing units (W-PFU). • The surface profiles of the W monoblocks of the W-PFU prototypes on the test frame to mimic the support structure of the ITER OVT were examined by using an optical three-dimensional measurement system. The results show the most W monoblock surface in the target part locates within + 0.25 mm from the CAD data. • The strict profile control with the profile tolerance of ±0.3 mm is imposed on the OVT to prevent the leading edges of the W monoblocks from over-heating. • The present full-scale prototyping demonstrates to satisfy this requirement on the surface profile. • It can be concluded that the technical maturities of JADA and its suppliers are as high as to start series manufacturing the ITER divertor components. - Abstract: Japan Atomic Energy Agency (JAEA) is in progress for technology demonstration toward Full-tungsten (W) ITER divertor outer vertical target (OVT), especially, W monoblock technology that needs to withstand the repetitive heat load as high as 20 MW/m{sup 2} for 10 s. Under the framework of the W divertor qualification program developed ITER organization, JAEA as Japanese Domestic Agency (JADA) manufactured seven full-scale plasma-facing unit (PFU) prototypes with the Japanese industries. Four prototypes that have 146 W monoblock joint with casted copper (Cu) interlayer passed successfully the ultrasonic testing. In the other three prototypes that have the different W/Cu interlayer joint, joint defects were found. The dimension measurements reveal the requirements of the gap between W monoblocks and the surface profile of PFU are feasible.

A model for phase evolution and volume expansion in tube type Nb3Sn conductors

Science.gov (United States)

Xu, X.; Sumption, M. D.; Collings, E. W.

2013-12-01

In this work, an analytic model for phase formation and volume expansion during heat treatment in tube type Nb3Sn strands is presented. Tube type Nb3Sn conductors consist of Nb or Nb-Ta alloy tube with a simple Cu/Sn binary metal insert to form the basic subelement (filament). A number of these elements, each with an outer Cu jacket, are restacked to form a multifilamentary strand. The present tube type conductors, with 4.2 K, 12 T non-Cu critical current density (Jc) in the 2000-2500 A mm-2 range and effective subelement diameters (deff) in the 12-36 μm range, are of interest for a number of applications. During the reaction of typical tube type strands, the Sn-Cu becomes molten and reacts with the Nb tube first to form NbSn2, then Nb6Sn5. At later times in the reaction sequence, all of the NbSn2 and Nb6Sn5 is converted to Nb3Sn. Some of the Nb3Sn is formed by a Nb-Sn reaction and has a fine grain (FG) structure, while some is converted from Nb6Sn5, which results in a coarse grain (CG) region. The fractions of FG and CG A15 are important in determining the final conductor properties. In this work we develop an analytic model to predict the radial extents of the various phases, and in particular the final FG and CG fractions based on the starting Nb, Cu, and Sn amounts in the subelements. The model is then compared to experimental results and seen to give reasonable agreement. By virtue of this model we outline an approach to minimize the CG regions in tube type and PIT strands and maximize the final FG area fractions. Furthermore, the volume change during the various reaction stages was also studied. It is proposed that the Sn content in the Cu-Sn alloy has a crucial influence on the radial expansion.

Numerical Analysis of Microwave Heating on Saponification Reaction

Science.gov (United States)

Huang, Kama; Jia, Kun

2005-01-01

Currently, microwave is widely used in chemical industry to accelerate chemical reactions. Saponification reaction has important applications in industry; some research results have shown that microwave heating can significantly accelerate the reaction [1]. But so far, no efficient method has been reported for the analysis of the heating process and design of an efficient reactor powered by microwave. In this paper, we present a method to study the microwave heating process on saponification reaction, where the reactant in a test tube is considered as a mixture of dilute solution. According to the preliminary measurement results, the effective permittivity of the mixture is approximately the permittivity of water, but the conductivity, which could change with the reaction, is derived from the reaction equation (RE). The electromagnetic field equation and reaction equation are coupled by the conductivity. Following that, the whole heating processes, which is described by Maxwell's equations, the reaction equation and heat transport equation (HTE), is analyzed by finite difference time domain (FDTD) method. The temperature rising in the test tube are measured and compared with the computational results. Good agreement can be seen between the measured and calculated results.

Prediction and validation of burnout curves for Goettelborn char using reaction kinetics determined in shock tube experiments

Energy Technology Data Exchange (ETDEWEB)

Moors, J.H.J.; Banin, V.E.; Haas, J.H.P.; Weber, R.; Veefkind, A. [Eindhoven University of Technology, Eindhoven (Netherlands). Dept. of Applied Physics

1999-01-01

Using a shock tube facility the combustion characteristics of pulverised char ({lt} 10 {mu}m) were measured. A prediction was made for the burnout behaviour of a commercial sized char particle (75-90 {mu}m) in different ambient conditions using a `pseudo kinetic` approach. In this approach the kinetic rate of a surface containing micro pores is determined and these `pseudo kinetics` are then applied to the larger particle not taking into account the micro pores. Comparison of the predictions with measurements done with an isothermal plug flow reactor showed this approach to be valid within experimental error for low burnout. A linear decrease of the kinetic reaction rate with burnout is shown to predict the burnout behaviour in the complete range of burnout. A possible explanation for this linear decrease could be a growing fraction of non-combustible material in the char particles during burnout. 11 refs., 6 figs., 2 tabs.

Dynamic and Stagnating Plasma Flow Leading to Magnetic-Flux-Tube Collimation

International Nuclear Information System (INIS)

You, S.; Yun, G.S.; Bellan, P.M.

2005-01-01

Highly collimated, plasma-filled magnetic-flux tubes are frequently observed on galactic, stellar, and laboratory scales. We propose that a single, universal magnetohydrodynamic pumping process explains why such collimated, plasma-filled magnetic-flux tubes are ubiquitous. Experimental evidence from carefully diagnosed laboratory simulations of astrophysical jets confirms this assertion and is reported here. The magnetohydrodynamic process pumps plasma into a magnetic-flux tube and the stagnation of the resulting flow causes this flux tube to become collimated

Analysis, scale modeling, and full-scale test of a railcar and spent-nuclear-fuel shipping cask in a high-velocity impact against a rigid barrier

International Nuclear Information System (INIS)

Huerta, M.

1981-06-01

This report describes the mathematical analysis, the physical scale modeling, and a full-scale crash test of a railcar spent-nuclear-fuel shipping system. The mathematical analysis utilized a lumped-parameter model to predict the structural response of the railcar and the shipping cask. The physical scale modeling analysis consisted of two crash tests that used 1/8-scale models to assess railcar and shipping cask damage. The full-scale crash test, conducted with retired railcar equipment, was carefully monitored with onboard instrumentation and high-speed photography. Results of the mathematical and scale modeling analyses are compared with the full-scale test. 29 figures

Nasogastric tube versus gastrostomy tube for gastric decompression in abdominal surgery: a prospective, randomized trial comparing patients' tube-related inconvenience.

Science.gov (United States)

Hoffmann, S; Koller, M; Plaul, U; Stinner, B; Gerdes, B; Lorenz, W; Rothmund, M

2001-11-01

Perioperative decompression of the stomach is still a common procedure and can be achieved using either nasogastric tubes (NTs) or gastrostomy tubes (GTs). While both procedures appear to be equally effective, some authors believe that NTs are less convenient for patients than GTs. However, to date, no reliable prospective data are available on this issue. We conducted a prospective, randomized trial comparing NTs versus GTs with a total of 110 patients undergoing elective colon surgery. The primary outcome measure was the patient's tube-related inconvenience and pain, assessed in a standardized interview on day 2 after surgery and quantified by means of a visual-analog scale (VAS). A questionnaire including the EORTC QLQ-C30 and additional items regarding retrospective tube-related judgements was administered on the day of discharge and 4 weeks after discharge. Secondary endpoints were the therapy-related morbidity and general complications. When patients were asked which of their drainage tubes (all patients had three or four drainage tubes, such as decompression drains, urinary drains, central venous line) was most inconvenient, 43% (CI 33-53%) in the NT group reported that the NT was most inconvenient, while only 4% (CI 1-10%) of the GT patients judged the GT most inconvenient ( Ptube system (day 2 p.o.: 71%, CI 61-80%; 4 weeks p.o.: 66%, CI 56-75%) than did GT patients (day 2 p.o.: 94%, CI 88-98%; 4 weeks p.o.: 91% CI 84-96%); again, these differences were statistically significant ( Ptube system have to weigh up the possibilities of different averse clinical as well as subjective outcomes. It is then preferable to include patients' preferences in the individual decision making process (shared-decision making).

Modeling a full-scale primary sedimentation tank using artificial neural networks.

Science.gov (United States)

Gamal El-Din, A; Smith, D W

2002-05-01

Modeling the performance of full-scale primary sedimentation tanks has been commonly done using regression-based models, which are empirical relationships derived strictly from observed daily average influent and effluent data. Another approach to model a sedimentation tank is using a hydraulic efficiency model that utilizes tracer studies to characterize the performance of model sedimentation tanks based on eddy diffusion. However, the use of hydraulic efficiency models to predict the dynamic behavior of a full-scale sedimentation tank is very difficult as the development of such models has been done using controlled studies of model tanks. In this paper, another type of model, namely artificial neural network modeling approach, is used to predict the dynamic response of a full-scale primary sedimentation tank. The neuralmodel consists of two separate networks, one uses flow and influent total suspended solids data in order to predict the effluent total suspended solids from the tank, and the other makes predictions of the effluent chemical oxygen demand using data of the flow and influent chemical oxygen demand as inputs. An extensive sampling program was conducted in order to collect a data set to be used in training and validating the networks. A systematic approach was used in the building process of the model which allowed the identification of a parsimonious neural model that is able to learn (and not memorize) from past data and generalize very well to unseen data that were used to validate the model. Theresults seem very promising. The potential of using the model as part of a real-time process control system isalso discussed.

Enantioselective Organocatalysis in Microreactors: Continuous Flow Synthesis of a (S-Pregabalin Precursor and (S-Warfarin

Directory of Open Access Journals (Sweden)

Riccardo Porta

2015-08-01

Full Text Available Continuous flow processes have recently emerged as a powerful technology for performing chemical transformations since they ensure some advantages over traditional batch procedures. In this work, the use of commercially available and affordable PEEK (Polyetheretherketone and PTFE (Polytetrafluoroethylene HPLC (High Performance Liquid Chromatography tubing as microreactors was exploited to perform organic reactions under continuous flow conditions, as an alternative to the commercial traditional glass microreactors. The wide availability of tubing with different sizes allowed quickly running small-scale preliminary screenings, in order to optimize the reaction parameters, and then to realize under the best experimental conditions a reaction scale up for preparative purposes. The gram production of some Active Pharmaceutical Ingredients (APIs such as (S-Pregabalin and (S-Warfarin was accomplished in short reaction time with high enantioselectivity, in an experimentally very simple procedure.

Full Scale Experiment with Interactive Urban Lighting

DEFF Research Database (Denmark)

Poulsen, Esben Skouboe; Andersen, Hans Jørgen; Jensen, Ole B.

2012-01-01

and region of occupancy of persons in the town square were monitored in real time by computer vision analyses of thermal images from 3 cameras monitoring the twin square. The results of the computer vision analyses were used to control the illumination from 16 3.5 meter high RGB LED Lamps that were......This paper presents and discusses the results of a full-scale interactive urban illumination experiment. The experiment investigates how human motion intensities can be used as input for controlling the illumination of a town square in the city of Aalborg in Denmark. The trajectory, velocity...... distributed across the square in an irregular grid. The lamps were DMX controlled. Using architectural models as sketching tools, 4 different illumination designs were developed and tested for a week in January. The result shows that in general people immersed in the square did not notice that the light...

Distribution of Clay Minerals in Light Coal Fractions and the Thermal Reaction Products of These Clay Minerals during Combustion in a Drop Tube Furnace

Directory of Open Access Journals (Sweden)

Sida Tian

2016-06-01

Full Text Available To estimate the contribution of clay minerals in light coal fractions to ash deposition in furnaces, we investigated their distribution and thermal reaction products. The light fractions of two Chinese coals were prepared using a 1.5 g·cm−3 ZnCl2 solution as a density separation medium and were burned in a drop-tube furnace (DTF. The mineral matter in each of the light coal fractions was compared to that of the relevant raw coal. The DTF ash from light coal fractions was analysed using hydrochloric acid separation. The acid-soluble aluminium fractions of DTF ash samples were used to determine changes in the amorphous aluminosilicate products with increasing combustion temperature. The results show that the clay mineral contents in the mineral matter of both light coal fractions were higher than those in the respective raw coals. For the coal with a high ash melting point, clay minerals in the light coal fraction thermally transformed more dehydroxylation products compared with those in the raw coal, possibly contributing to solid-state reactions of ash particles. For the coal with a low ash melting point, clay minerals in the light coal fraction produced more easily-slagging material compared with those in the raw coal, playing an important role in the occurrence of slagging. Additionally, ferrous oxide often produces low-melting substances in coal ash. Due to the similarities of zinc oxide and ferrous oxide in silicate reactions, we also investigated the interactions of clay minerals in light coal fractions with zinc oxide introduced by a zinc chloride solution. The extraneous zinc oxide could react, to a small extent, with clay minerals in the coal during DTF combustion.

Converting Hangar High Expansion Foam Systems to Prevent Cockpit Damage: Full-Scale Validation Tests

Science.gov (United States)

2017-09-01

AFCEC-CO-TY-TR-2018-0001 CONVERTING HANGAR HIGH EXPANSION FOAM SYSTEMS TO PREVENT COCKPIT DAMAGE: FULL-SCALE VALIDATION TESTS Gerard G...manufacturer, or otherwise does not constitute or imply its endorsement, recommendation , or approval by the United States Air Force. The views and...09-2017 Final Test Report May 2017 Converting Hangar High Expansion Foam Systems to Prevent Cockpit Damage: Full-Scale Validation Tests N00173-15-D

Small scale lithium-lead/water-interaction studies

International Nuclear Information System (INIS)

Kranert, O.; Kottowski, H.

1991-01-01

One current concept in fusion blanket design is to utilize water as the coolant and liquid lithium-lead as the breeding/neutron multiplier material. Considering the complex design of the blanket module, it is likely that a water leakage into the liquid alloy may occur due to a tube rupture provoking an intolerable pressure increase in the blanket module. The pressure increase is caused by the combined chemical and thermohydraulic reaction of lithium-lead with water. Experiments which simulate such a transient event are necessary to obtain information which is important for the blanket module design. The interaction has been investigated by conducting small-scale experiments at various injection pressures, alloy- and coolant temperatures. Besides using eutectic Li 17 Pb 83 , Li 7 Pb 2 , lithium and lead have been used. Among other results, the experiments indicate increasing chemical reaction with increasing lithium concentration. At the same time, the chemical reaction inhibits violent thermohydaulic reactions due to the attenuating effect of the hydrogen produced. The preliminary epxerimental results from Li 17 Pb 83 and Li 7 Pb 2 reveal that the pressure- and temperature transients caused by the chemical and thermohydraulic reactions lie within technically manageable limits. (orig.)

Infrared Chemiluminescence Studies of Ion-Molecule Reactions in a Flowing Afterglow.

Science.gov (United States)

1982-01-01

reaction rate constants and branching ratios have been addressed in drift tubes and flow drift systems, and the translational energy distribution of atomic...composed of about 40 thin cylindrical sections of flow tube , separated by mylar spacers and connected by precision resistors. In the region of LIF... tube radius (Albritton, 1967). For proper operation of a drift tube , ionic species of only one polarity can be present. Efficient separation of

Comparison of Test and Finite Element Analysis for Two Full-Scale Helicopter Crash Tests

Science.gov (United States)

Annett, Martin S.; Horta,Lucas G.

2011-01-01

Finite element analyses have been performed for two full-scale crash tests of an MD-500 helicopter. The first crash test was conducted to evaluate the performance of a composite deployable energy absorber under combined flight loads. In the second crash test, the energy absorber was removed to establish the baseline loads. The use of an energy absorbing device reduced the impact acceleration levels by a factor of three. Accelerations and kinematic data collected from the crash tests were compared to analytical results. Details of the full-scale crash tests and development of the system-integrated finite element model are briefly described along with direct comparisons of acceleration magnitudes and durations for the first full-scale crash test. Because load levels were significantly different between tests, models developed for the purposes of predicting the overall system response with external energy absorbers were not adequate under more severe conditions seen in the second crash test. Relative error comparisons were inadequate to guide model calibration. A newly developed model calibration approach that includes uncertainty estimation, parameter sensitivity, impact shape orthogonality, and numerical optimization was used for the second full-scale crash test. The calibrated parameter set reduced 2-norm prediction error by 51% but did not improve impact shape orthogonality.

Characterization of Membrane Foulants in Full-scale and Lab-scale Membrane Bioreactors for Wastewater Treatment and Reuse

KAUST Repository

Matar, Gerald

2015-01-01

full-scale MBRs differed significantly from the source community (i.e. activated sludge), and random immigration of species from the source community was unlikely to shape the community structure of biofilms. Also, a core biofouling community was shared

Concrete-Filled Steel Tube Arch Bridges in China

Directory of Open Access Journals (Sweden)

Jielian Zheng

2018-02-01

Full Text Available In the past 20 years, great progress has been achieved in China in the construction of concrete-filled steel tube (CFST arch bridges and concrete arch bridges with a CFST skeleton. The span of these bridges has been increasing rapidly, which is rare in the history of bridge development. The large-scale construction of expressways and high-speed railways demands the development of long-span arch bridges, and advances in design and construction techniques have made it possible to construct such bridges. In the present study, the current status, development, and major innovative technologies of CFST arch bridges and concrete arch bridges with a CFST skeleton in China are elaborated. This paper covers the key construction technologies of CFST arch bridges, such as the design, manufacture, and installation of steel tube arch trusses, the preparation and pouring of in-tube concrete, and the construction of the world’s longest CFST arch bridge—the First Hejiang Yangtze River Bridge. The main construction technologies of reinforced concrete arch bridges are also presented, which include cable-stayed fastening-hanging cantilever assembly, adjusting the load by means of stay cables, surrounding the concrete for arch rib pouring, and so forth. In addition, the construction of two CFST skeleton concrete arch bridges—the Guangxi Yongning Yong River Bridge and the Yunnan–Guangxi Railway Nanpan River Bridge—is discussed. CFST arch bridges in China have already gained a world-leading position; with the continuous innovation of key technologies, China will become the new leader in promoting the development of arch bridges. Keywords: Concrete-filled steel tube (CFST arch bridge, Steel-reinforced concrete arch bridge, Cable-stayed fastening-hanging cantilever assembly, Vacuum-assisted pouring in-tube concrete, Adjusting load by stay cables

CFD modeling of a boiler's tubes rupture

International Nuclear Information System (INIS)

Rahimi, Masoud; Khoshhal, Abbas; Shariati, Seyed Mehdi

2006-01-01

This paper reports the results of a study on the reason for tubes damage in the superheater Platen section of the 320 MW Bisotoun power plant, Iran. The boiler has three types of superheater tubes and the damage occurs in a series of elbows belongs to the long tubes. A three-dimensional modeling was performed using an in-house computational fluid dynamics (CFD) code in order to explore the reason. The code has ability of simultaneous solving of the continuity, the Reynolds-Averaged Navier-Stokes (RANS) equations and employing the turbulence, combustion and radiation models. The whole boiler including; walls, burners, air channels, three types of tubes, etc., was modeled in the real scale. The boiler was meshed into almost 2,000,000 tetrahedral control volumes and the standard k-ε turbulence model and the Rosseland radiation model were used in the model. The theoretical results showed that the inlet 18.9 MPa saturated steam becomes superheated inside the tubes and exit at a pressure of 17.8 MPa. The predicted results showed that the temperature of the steam and tube's wall in the long tubes is higher than the short and medium size tubes. In addition, the predicted steam mass flow rate in the long tube was lower than other ones. Therefore, it was concluded that the main reason for the rupture in the long tubes elbow is changing of the tube's metal microstructure due to working in a temperature higher than the design temperature. In addition, the structural fatigue tension makes the last elbow of the long tube more ready for rupture in comparison with the other places. The concluded result was validated by observations from the photomicrograph of the tube's metal samples taken from the damaged and undamaged sections

Nucleate boiling heat transfer on horizontal tubes in bundles

International Nuclear Information System (INIS)

Fujital, Y.; Ohta, H.; Hidaka, S.; Nishikawa, K.

1986-01-01

In order to clarify the heat transfer mechanisms of the flooded type horizontal tube bundle evaporator, heat transfer characteristics of tube bundles of experimental scale which consist both of smooth and enhanced tubes were investigated in detail. The experiments of saturated nucleate boiling were performed by using Freon 113 under pressures 0.1 to 1 MPa, and the effects of various parameters, for example, bundle arrangement, heat flux, pressure on the characteristics of an individual tube are clarified. Experimental data is reproduced well by a proposed heat transfer model in which convective heat transfer coefficients due to rising bubbles are estimated as a function of their volumetric flow rate

Monitoring of full-scale hydrodynamic cavitation pretreatment in agricultural biogas plant.

Science.gov (United States)

Garuti, Mirco; Langone, Michela; Fabbri, Claudio; Piccinini, Sergio

2018-01-01

The implementation of hydrodynamic cavitation (HC) pretreatment for enhancing the methane potential from agricultural biomasses was evaluated in a full scale agricultural biogas plant, with molasses and corn meal as a supplementary energy source. HC batch tests were run to investigate the influence on methane production, particle size and viscosity of specific energy input. 470kJ/kgTS was chosen for the full-scale implementation. Nearly 6-months of operational data showed that the HC pretreatment maximized the specific methane production of about 10%, allowing the biogas plant to get out of the fluctuating markets of supplementary energy sources and to reduce the methane emissions. HC influenced viscosity and particle size of digestate, contributing to reduce the energy demand for mixing, heating and pumping. In the light of the obtained results the HC process appears to be an attractive and energetically promising alternative to other pretreatments for the degradation of biomasses in biogas plant. Copyright © 2017 Elsevier Ltd. All rights reserved.

Team training using full-scale reactor coolant pump seal mock-ups

International Nuclear Information System (INIS)

McDonald, T.J.; Hamill, R.W.

1987-01-01

The use of full-scale reactor coolant pump (RCP) seal mock-ups has greatly enhanced Northeast Utilities' ability to effectively utilize the team training approach to technical training. With the advent of the Institute of Nuclear Power Operations accreditation come a new emphasis and standards for the integrated training of plant engineering personnel, maintenance mechanics, quality control personnel, and health physics personnel. The results of purchasing full-scale RCP mock-ups to pilot the concept of team training have far exceeded expectations and cost-limiting factors. The initial training program analysis identified RCP seal maintenance as a task that required training for maintenance department personnel. Due to radiation exposure considerations and the unavailability of actual plant equipment for training purposes, the decision was made to procure a mock-up of an RCP seal assembly and housing. This mock-up was designed to facilitate seal cartridge removal, disassembly, assembly, and installation, duplicating all internal components of the seal cartridge and housing area in exact detail

Reliability of double-wall-tube steam generator for FBR considering water leak accident frequency

International Nuclear Information System (INIS)

Ueda, Nobuyuki; Kinoshita, Izumi; Nishi, Yoshihisa

2000-01-01

For early realization, a fast breeder reactor (FBR) is required to reduce construction cost. A reactor concept in which the intermediate heat transport system is eliminated by introducing a double-wall-tube steam generator is one convincing approach. The reliability of the double-wall-tube SG in a water leak accident (sodium-water reaction accident) due to tube failure is strongly related to the mitigating system design. The safety design of the double-wall-tube SG approach is investigated to limit the accident occurrence below 10 -7 (1/ry. A tube-to-tube weld is excluded from the reference design, because the welding process is too difficult and complicated to effectively prevent adhesion of the double-wall-tube. The reliability of the tube-to-tube plate was evaluated at 10 -10 (l/hr) for an inner tube and 10 -9 (l/hr) for an outer with reference to the failure experience of previous SGs. The failure must be detected within 30 to 60 minutes. (author)

Origami tubes with reconfigurable polygonal cross-sections.

Science.gov (United States)

Filipov, E T; Paulino, G H; Tachi, T

2016-01-01

Thin sheets can be assembled into origami tubes to create a variety of deployable, reconfigurable and mechanistically unique three-dimensional structures. We introduce and explore origami tubes with polygonal, translational symmetric cross-sections that can reconfigure into numerous geometries. The tubular structures satisfy the mathematical definitions for flat and rigid foldability, meaning that they can fully unfold from a flattened state with deformations occurring only at the fold lines. The tubes do not need to be straight and can be constructed to follow a non-linear curved line when deployed. The cross-section and kinematics of the tubular structures can be reprogrammed by changing the direction of folding at some folds. We discuss the variety of tubular structures that can be conceived and we show limitations that govern the geometric design. We quantify the global stiffness of the origami tubes through eigenvalue and structural analyses and highlight the mechanical characteristics of these systems. The two-scale nature of this work indicates that, from a local viewpoint, the cross-sections of the polygonal tubes are reconfigurable while, from a global viewpoint, deployable tubes of desired shapes are achieved. This class of tubes has potential applications ranging from pipes and micro-robotics to deployable architecture in buildings.

Origami tubes with reconfigurable polygonal cross-sections

Science.gov (United States)

Filipov, E. T.; Paulino, G. H.; Tachi, T.

2016-01-01

Thin sheets can be assembled into origami tubes to create a variety of deployable, reconfigurable and mechanistically unique three-dimensional structures. We introduce and explore origami tubes with polygonal, translational symmetric cross-sections that can reconfigure into numerous geometries. The tubular structures satisfy the mathematical definitions for flat and rigid foldability, meaning that they can fully unfold from a flattened state with deformations occurring only at the fold lines. The tubes do not need to be straight and can be constructed to follow a non-linear curved line when deployed. The cross-section and kinematics of the tubular structures can be reprogrammed by changing the direction of folding at some folds. We discuss the variety of tubular structures that can be conceived and we show limitations that govern the geometric design. We quantify the global stiffness of the origami tubes through eigenvalue and structural analyses and highlight the mechanical characteristics of these systems. The two-scale nature of this work indicates that, from a local viewpoint, the cross-sections of the polygonal tubes are reconfigurable while, from a global viewpoint, deployable tubes of desired shapes are achieved. This class of tubes has potential applications ranging from pipes and micro-robotics to deployable architecture in buildings. PMID:26997894

Single and two-phase similarity analysis of a reduced-scale natural convection loop relative to a full-scale prototype

International Nuclear Information System (INIS)

Botelho, David A.; Faccini, Jose L.H.

2002-01-01

The main topic in this paper is a new device being considered to improve nuclear reactor safety employing the natural circulation. A scaled experiment used to demonstrate the performance of the device is also described. We also applied a similarity analysis method for single and two-phase natural convection loop flow to the IEN CCN experiment and to an APEX like experiment to verify the degree of similarity relative to a full-scale prototype like the AP600. Most of the CCN similarity numbers that represent important single and two-phase similarity conditions are comparable to the APEX like loop non-dimensional numbers calculated employing the same methodology. Despite the much smaller geometric, pressure, and power scales, we conclude that the IEN CCN has single and two-phase natural circulation similarity numbers that represent fairly well the full-scale prototype. even lacking most complementary primary and safety systems, this IEN circuit provided a much valid experience to develop human, experimental, and analytical resources, besides its utilization as a training tool. (author)

Numerical simulations of a full-scale polymer electrolyte fuel cell with analysing systematic performance in an automotive application

International Nuclear Information System (INIS)

Park, Heesung

2015-01-01

Highlights: • A 3-D full-scale fuel cell performance is numerically simulated. • Generated and consumed power in the system is affected by operating condition. • Systematic analysis predicts the net power of conceptual PEFC stack. - Abstract: In fuel cell powered electric vehicles, the net power efficiency is a critical factor in terms of fuel economy and commercialization. Although the fuel cell stack produces enough power to drive the vehicles, the transferred power to the power train could be significantly reduced due to the power consumption to operate the system components of air blower and cooling module. Thus the systematic analysis on the operating condition of the fuel cell stack is essential to predict the net power generation. In this paper numerical simulation is conducted to characterize the fuel cell performance under various operating conditions. Three dimensional and full-scale fuel cell of the active area of 355 cm 2 is numerically modelled with 47.3 million grids to capture the complexities of the fluid dynamics, heat transfer and electrochemical reactions. The proposed numerical model requires large computational time and cost, however, it can be powerful to reasonably predict the fuel cell system performance at the early stage of conceptual design without requiring prototypes. Based on the model, it has been shown that the net power is reduced down to 90% of the gross power due to the power consumption of air blower and cooling module

Effects of heat exchanger tubes on hydrodynamics and CO 2 capture of a sorbent-based fluidized bed reactor

Energy Technology Data Exchange (ETDEWEB)

Lai, Canhai; Xu, Zhijie; Li, Tingwen; Lee, Andrew; Dietiker, Jean-François; Lane, William; Sun, Xin

2017-12-01

In virtual design and scale up of pilot-scale carbon capture systems, the coupled reactive multiphase flow problem must be solved to predict the adsorber’s performance and capture efficiency under various operation conditions. This paper focuses on the detailed computational fluid dynamics (CFD) modeling of a pilot-scale fluidized bed adsorber equipped with vertical cooling tubes. Multiphase Flow with Interphase eXchanges (MFiX), an open-source multiphase flow CFD solver, is used for the simulations with custom code to simulate the chemical reactions and filtered models to capture the effect of the unresolved details in the coarser mesh for simulations with reasonable simulations and manageable computational effort. Previously developed two filtered models for horizontal cylinder drag, heat transfer, and reaction kinetics have been modified to derive the 2D filtered models representing vertical cylinders in the coarse-grid CFD simulations. The effects of the heat exchanger configurations (i.e., horizontal or vertical) on the adsorber’s hydrodynamics and CO2 capture performance are then examined. The simulation result subsequently is compared and contrasted with another predicted by a one-dimensional three-region process model.

Flow Induced segregation in full scale castings with SCC

DEFF Research Database (Denmark)

Thrane, Lars Nyholm; Stang, Henrik; Geiker, Mette Rica

2007-01-01

induced segregation is a major risk during casting and it is not yet clear how this phenomenon should be modelled. In this paper testing and numerical simulations of full-scale wall castings are compared. Two different SCCs and three different filling methods were applied resulting in different flow...... patterns during form filling. Results show that the flow patterns have a major influence on the risk of flow induced segregation and the surface finish of the hardened concrete. A hypothesis for the mechanism of flow induced segregation is put forth....

Flame oscillations in tubes with nonslip at the walls

Energy Technology Data Exchange (ETDEWEB)

Akkerman, V' yacheslav; Bychkov, Vitaly; Petchenko, Arkady [Institute of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); Eriksson, Lars-Erik [Department of Applied Mechanics, Chalmers University of Technology, 412 96 Goeteborg (Sweden)

2006-06-15

A laminar premixed flame front propagating in a two-dimensional tube is considered with nonslip at the walls and with both ends open. The problem of flame propagation is solved using direct numerical simulations of the complete set of hydrodynamic equations including thermal conduction, diffusion, viscosity, and chemical kinetics. As a result, it is shown that flame interaction with the walls leads to the oscillating regime of burning. The oscillations involve variations of the curved flame shape and the velocity of flame propagation. The oscillation parameters depend on the characteristic tube width, which controls the Reynolds number of the flow. In narrow tubes the oscillations are rather weak, while in wider tubes they become stronger with well-pronounced nonlinear effects. The period of oscillations increases for wider tubes, while the average flame length scaled by the tube diameter decreases only slightly with increasing tube width. The average flame length calculated in the present work is in agreement with that obtained in the experiments. Numerical results reduce the gap between the theory of turbulent flames and the experiments on turbulent combustion in tubes. (author)

Full Scale Drinking Water System Decontamination at the Water Security Test Bed

Data.gov (United States)

U.S. Environmental Protection Agency — The EPA’s Water Security Test Bed (WSTB) facility is a full-scale representation of a drinking water distribution system. In collaboration with the Idaho National...

Design, Fabrication and Test of a Full Scale Copper Tubular Combustion Chamber

National Research Council Canada - National Science Library

Cooley, Christine

2002-01-01

This paper presents the design fabrication and test of a full scale copper tubular combustion chamber as an enabling technology for future application in a high thrust upper-stage expander-cycle engine...

a Study of Ultrasonic Wave Propagation Through Parallel Arrays of Immersed Tubes

Science.gov (United States)

Cocker, R. P.; Challis, R. E.

1996-06-01

Tubular array structures are a very common component in industrial heat exchanging plant and the non-destructive testing of these arrays is essential. Acoustic methods using microphones or ultrasound are attractive but require a thorough understanding of the acoustic properties of tube arrays. This paper details the development and testing of a small-scale physical model of a tube array to verify the predictions of a theoretical model for acoustic propagation through tube arrays developed by Heckl, Mulholland, and Huang [1-5] as a basis for the consideration of small-scale physical models in the development of non-destructive testing procedures for tube arrays. Their model predicts transmission spectra for plane waves incident on an array of tubes arranged in straight rows. Relative transmission is frequency dependent with bands of high and low attenuation caused by resonances within individual tubes and between tubes in the array. As the number of rows in the array increases the relative transmission spectrum becomes more complex, with increasingly well-defined bands of high and low attenuation. Diffraction of acoustic waves with wavelengths less than the tube spacing is predicted and appears as step reductions in the transmission spectrum at frequencies corresponding to integer multiples of the tube spacing. Experiments with the physical model confirm the principle features of the theoretical treatment.

Multi-walled carbon nano-tubes for energy storage and production applications

International Nuclear Information System (INIS)

Andrews, R.; Jacques, D.; Likpa, S.; Qian, D.; Rantell, T.; Anthony, J.

2005-01-01

Full text of publication follows: Since their discovery, carbon nano-tubes have been proposed as candidate materials for a broad range of applications, including high strength composites, molecular electronics, and energy storage. In many cases, nano-tubes have been proposed to replace traditional carbon materials, such as activated carbons in energy storage devices. In other cases, novel applications have been proposed, such as the use of carbon nano-tube arrays in photovoltaic devices. The use of multi-walled carbon nano-tubes in energy storage devices has generated great interest due to their high inherent conductivity, layered structure, and high surface area per volume compared to traditional graphitic materials. However as produced nano-tubes do not possess ideal properties, and exhibit only modest charge storage. We have explored the charge storage abilities of nano-tubes with varying morphologies (fullerenic versus stacked cones), nano-tubes containing N or B dopants, as well as various post-treatments of the nano-tubes. The use of nano-tubes in charge storage devices will be described, as well as modification of the nano-tube surfaces or morphology to improve this performance. The synthesis of nano-tubes with several differing hetero-atom dopants will also be described, as well as the effect of heat treatment on these structures. One of the most significant problems in organic photovoltaics is the typically low charge-carrier mobility in organic thin films which, coupled with short exciton diffusion lengths, means that photo-generated charge-carrier pairs are more likely to re-combine than reach an electrode to generate current. Two organic systems with high charge-carrier mobilities are carbon nano-tubes (here, MWNTs) and acene-based organic semiconductors. We believe that blended devices based on MWNTs and organic semiconductors could lead to the next class of efficient, flexible and inexpensive organic photovoltaic systems. We have developed methods to

Operational experience with a seasonally operated full-scale membrane bioreactor plant

Czech Academy of Sciences Publication Activity Database

Gómez, M.; Dvořák, L.; Růžičková, I.; Holba, Marek; Wanner, J.

2012-01-01

Roč. 121, OCT 2012 (2012), s. 241-247 ISSN 0960-8524 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : full-scale membrane bioreactor * soluble microbibal products * nutrient removal * fouling * microbiological effluent quality Subject RIV: EF - Botanics Impact factor: 4.750, year: 2012

URANIUM REMOVAL FROM DRINKING WATER USING A SMALL FULL-SCALE SYSTEM

Science.gov (United States)

This report presents background and history of water quality, the basis for design and nine months of actual operating data for a small, full-scale strong-base ion exchange system that is used to remove uranium from a water supply serving a school in Jefferson County, CO. Informa...

Hydrogen production by high-temperature electrolysis of water vapor steam. Test results obtained with an electrolysis tube

International Nuclear Information System (INIS)

Hino, Ryutaro; Miyamoto, Yoshiaki

1995-01-01

High-temperature electrolysis of water vapor steam is an advanced hydrogen production process decomposing high temperature steam up to 1,000degC, which applies an electro-chemical reaction reverse to the solid oxide fuel cell. At Japan Atomic Energy Research Institute, laboratory-scale experiments have been conducted using a practical electrolysis tube with 12 electrolysis cells in order to develop heat utilization systems for high-temperature gas-cooled reactors. The electrolysis cells of which electrolyte was yttria-stabilized zirconia were formed on a porous ceramic tube in series by plasma spraying. In the experiments, water steam mixed with argon carrier gas was supplied into the electrolysis tube heated at a constant temperature regulated in the range from 850degC to 950degC, and electrolysis power was supplied by a DC power source. Hydrogen production rate increased with applied voltage and electrolysis temperature; the maximum production rate was 6.9Nl/h at 950degC. Hydrogen production rate was correlated with applied current densities on the basis of experimental data. High energy efficiency was achieved under the applied current density ranging from 80 to 100 mA/cm 2 . (author)

The Educational Potential of YouTube.

Science.gov (United States)

Godwin, Haley T; Khan, Murtaza; Yellowlees, Peter

2017-12-01

The objective of this paper was to examine the educational potential and effectiveness of a 3 min video clip of a simulation of schizophrenia published online at YouTube. Researchers examined the 267 public comments published on the video-sharing website YouTube over 8 years by viewers of a schizophrenia simulation video titled "virtual hallucinations" made in the Second Life game platform. Comments were independently categorized into six groupings, then cooperatively finalized, and qualitatively analyzed. The six categories of style of comments were "Emotional" (n = 76), "Identification" (n = 62), "Educational Interest" (n = 45), "Mocking/Displeased" (n = 36), "Game Interest" (n = 32), and "Other" (n = 25). Without any advertising or marketing by the creators, over 194,400 views of the video were recorded in 8 years, an average of about 1500 views per month. The use of YouTube with its viral marketing potential has created a vastly amplified reach for this educational offering that would otherwise have been impossible. Qualitative analysis of publically posted comments in response to the video, which were generally positive, has led to a greater understanding of public reactions to such educational offerings. YouTube videos are already a rich source of data for psychiatric researchers, and psychiatric educators should consider posting high quality video clips on publically available social media platforms such as YouTube in order to reduce public stigma about psychiatric disorders and patients.

A Limited Evaluation of Full Scale Control Surface Deflection Drag (Have FUN)

National Research Council Canada - National Science Library

Reinhardt, R. B; Celi, Sean A; Geraghty, Jeffrey T; Stahl, James W; Glover, Victor J; Bowman, Geoffrey G

2007-01-01

The Have FUN (FUll Scale Numbers) Test Management Project was conducted at the request of the USAF TPS as an investigation into the drag caused by control surface deflection during dynamic soaring techniques...

Characteristics of the JRR-3M neutron guide tubes

International Nuclear Information System (INIS)

Suzuki, Masatoshi; Ichikawa, Hiroki; Kawabata, Yuji.

1993-01-01

Large scale neutron guide tubes have been installed in the upgraded JRR-3 (Japan Research Reactor No.3, JRR-3M). The total length of the guide tubes is 232m. The neutron fluxes and spectra were measured at the end of the neutron guide tubes. The neutron fluxes of thermal neutron guide tubes with characteristic wavelength of 2A are 1.2 x 10 8 n/cm 2 · s. The neutron fluxes of cold guide tubes are 1.4 x 10 8 n/cm 2 · s with characteristic wavelength of 4A and 2.0 x 10 8 n/cm 2 · s with 6A when the cold neutron source is operated. The neutron spectra measured by time-of-flight method agree well with their designed ones. (author)

Growth dynamics and composition of tubular structures in a reaction-precipitation system

Science.gov (United States)

Pagano, Jason John

Self-organization in reaction precipitation systems occurs in many physical, chemical, biological, and geological systems. In particular, chemical reactions provide a wealth of examples for this intriguing process. Permanent tubular structures arise from the interplay of chemical and transport phenomena such as diffusion and fluid flow. These astonishing tubular structures are prevalent throughout nature. Examples include black smokers at hydrothermal vents, silica tubes in setting cement, soda-straw stalactites in caves, and biological structures such as the outer skeleton of certain algae. In this work, the aim is to establish and understand a laboratory scale model by examining the, seemingly simple, precipitation reaction between sodium silicate and copper sulfate as well as zinc sulfate. The tubular precipitation structures in so-called silica gardens are known to many scientists and non-scientists alike. However, little is known regarding their growth dynamics and chemical composition. We devised an injection technique which provides control over parameters that are not accessible in the classic silica garden system. For the example of cupric sulfate injection into waterglass solution, we identify three distinct growth regimes (jetting, popping, and budding) and study their concentration dependent transitions. Here we describe the composition and morphology of the tube material using techniques such as electron microscopy and vibrational spectroscopy. Specifically, we find that the tube wall consists of metal hydroxide that is stabilized by a thin, exterior silica layer. After synthesis the tubes can be further modified by using chemical and/or physical means. A second study aims to understand tubule formation under "reverse" conditions. More specifically, waterglass is being injected into lighter cupric sulfate solution. In these experiments, single, downward growing precipitation tubes are created. Four distinct growth regimes are observed and their

Modelling of a one pass smoke tube boiler

DEFF Research Database (Denmark)

Karstensen, Claus M. S.; Sørensen, Kim

2004-01-01

A nonlinear state-space model with five states describing a one pass smoke tube boiler has been formulated. By means of mass- and energy-balance the model describes the dynamics of the Furnace, the Convection Zone and the Water/Steam Part and the three sub models are merged into an overall model....... The model is further linearized for use in a linear control design. The simulations have been carried out by means of MATLAB/SIMULINK and the models have been verified with measurements from a full scale boiler plant. Parameters in the model that are difficult to calculate have been estimated and the method...

DNA nanotechnology from the test tube to the cell.

Science.gov (United States)

Chen, Yuan-Jyue; Groves, Benjamin; Muscat, Richard A; Seelig, Georg

2015-09-01

The programmability of Watson-Crick base pairing, combined with a decrease in the cost of synthesis, has made DNA a widely used material for the assembly of molecular structures and dynamic molecular devices. Working in cell-free settings, researchers in DNA nanotechnology have been able to scale up system complexity and quantitatively characterize reaction mechanisms to an extent that is infeasible for engineered gene circuits or other cell-based technologies. However, the most intriguing applications of DNA nanotechnology - applications that best take advantage of the small size, biocompatibility and programmability of DNA-based systems - lie at the interface with biology. Here, we review recent progress in the transition of DNA nanotechnology from the test tube to the cell. We highlight key successes in the development of DNA-based imaging probes, prototypes of smart therapeutics and drug delivery systems, and explore the future challenges and opportunities for cellular DNA nanotechnology.

DNA nanotechnology from the test tube to the cell

Science.gov (United States)

Chen, Yuan-Jyue; Groves, Benjamin; Muscat, Richard A.; Seelig, Georg

2015-09-01

The programmability of Watson-Crick base pairing, combined with a decrease in the cost of synthesis, has made DNA a widely used material for the assembly of molecular structures and dynamic molecular devices. Working in cell-free settings, researchers in DNA nanotechnology have been able to scale up system complexity and quantitatively characterize reaction mechanisms to an extent that is infeasible for engineered gene circuits or other cell-based technologies. However, the most intriguing applications of DNA nanotechnology -- applications that best take advantage of the small size, biocompatibility and programmability of DNA-based systems -- lie at the interface with biology. Here, we review recent progress in the transition of DNA nanotechnology from the test tube to the cell. We highlight key successes in the development of DNA-based imaging probes, prototypes of smart therapeutics and drug delivery systems, and explore the future challenges and opportunities for cellular DNA nanotechnology.

Scaling analysis in modeling transport and reaction processes a systematic approach to model building and the art of approximation

CERN Document Server

Krantz, William B

2007-01-01

This book is unique as the first effort to expound on the subject of systematic scaling analysis. Not written for a specific discipline, the book targets any reader interested in transport phenomena and reaction processes. The book is logically divided into chapters on the use of systematic scaling analysis in fluid dynamics, heat transfer, mass transfer, and reaction processes. An integrating chapter is included that considers more complex problems involving combined transport phenomena. Each chapter includes several problems that are explained in considerable detail. These are followed by several worked examples for which the general outline for the scaling is given. Each chapter also includes many practice problems. This book is based on recognizing the value of systematic scaling analysis as a pedagogical method for teaching transport and reaction processes and as a research tool for developing and solving models and in designing experiments. Thus, the book can serve as both a textbook and a reference boo...

Technical Design Report for the: PANDA Straw Tube Tracker

CERN Document Server

Erni, W; Krusche, B; Steinacher, M; Heng, Y; Liu, Z; Liu, H; Shen, X; Wang, Q; Xu, H; Aab, A; Albrecht, M; Becker, J; Csapó, A; Feldbauer, F; Fink, M; Friedel, P; Heinsius, F H; Held, T; Klask, L; Koch, H; Kopf, B; Leiber, S; Leyhe, M; Motzko, C; Pelizäus, M; Pychy, J; Roth, B; Schröder, T; Schulze, J; Sowa, C; Steinke, M; Trifterer, T; Wiedner, U; Zhong, J; Beck, R; Bianco, S; Brinkmann, K T; Hammann, C; Hinterberger, F; Kaiser, D; Kliemt, R; Kube, M; Pitka, A; Quagli, T; Schmidt, C; Schmitz, R; Schnell, R; Thoma, U; Vlasov, P; Walther, D; Wendel, C; Würschig, T; Zaunick, H G; Bianconi, A; Bragadireanu, M; Caprini, M; Pantea, D; Pantelica, D; Pietreanu, D; Serbina, L; Tarta, P D; Kaplan, D; Fiutowski, T; Idzik, M; Mindur, B; Przyborowski, D; Swientek, K; Czech, B; Kistryn, M; Kliczewski, S; Kozela, A; Kulessa, P; Lebiedowicz, P; Pysz, K; Schäfer, W; Siudak, R; Szczurek\\inst, A; Jowzaee, S; Kajetanowicz, M; Kamys, B; Kistryn, S; Korcyl, G; Korcyl, K; Krzemien, W; Magiera, A; Moskal, P; Palka, M; Rudy, Z; Salabura, P; Smyrski, J; Wrońska\\inst, A; Al-Turany, M; Arora, R; Augustin, I; Deppe, H; Flemming, H; Gerhardt, A; Götzen, K; Jordi, A F; Kalicy, G; Karabowicz, R; Lehmann, D; Lewandowski, B; Lühning, J; Maas, F; Orth, H; Patsyuk, M; Peters, K; Saito, T; Schepers, G; Schmidt, C J; Schmitt, L; Schwarz, C; Schwiening, J; Traxler, M; Voss, B; Wieczorek, P; Wilms, A; Zühlsdorf\\inst, M; Abazov, V M; Alexeev, G; Arefiev, A; Astakhov, V I; Barabanov, M Yu; Batyunya, B V; Davydov, Yu I; Dodokhov, V Kh; Efremov, A A; Fedunov, A G; Festchenko, A A; Galoyan, A S; Grigoryan, S; Karmokov, A; Koshurnikov, E K; Lobanov, V I; Lobanov, Yu Yu; Makarov, A F; Malinina, L V; Malyshev, V L; Mustafaev, G A; Olshevskiy, A; Pasyuk, M A; Perevalova, E A; Piskun, A A; Pocheptsov, T A; Pontecorvo, G; Rodionov, V K; Rogov, Yu N; Salmin, R A; Samartsev, A G; Sapozhnikov, M G; Shabratova, G S; Skachkova, A N; Skachkov, N B; Strokovsky, E A; Suleimanov, M K; Teshev, R Sh; Tokmenin, V V; Uzhinsky, V V; Vodopyanov, A S; Zaporozhets, S A; Zhuravlev, N I; Zorin, A G; Branford, D; Glazier, D; Watts, D; Woods, P; Britting, A; Eyrich, W; Lehmann, A; Uhlig, F; Dobbs, S; Metreveli, Z; Seth, K; Tomaradze, A; Xiao, T; Bettoni, D; Carassiti, V; Ramusino, A Cotta; Dalpiaz, P; Drago, A; Fioravanti, E; Garzia, I; Savriè, M; Stancari, G; Bianchi, N; Gianotti, P; Guaraldo, C; Lucherini, V; Orecchini, D; Pace, E; Bersani, A; Bracco, G; Macri, M; Parodi, R F; Bremer, D; Dormenev, V; Drexler, P; Düren, M; Eissner, T; Föhl, K; Galuska, M; Gessler, T; Hayrapetyan, A; Hu, J; Koch, P; Kröck, B; Kühn, W; Lange, S; Liang, Y; Merle, O; Metag, V; Moritz, M; Münchow, D; Nanova, M; Novotny, R; Spruck, B; Stenzel, H; Ullrich, T; Werner, M; Xu, H; Euan, C; Hoek, M; Ireland, D; Keri, T; Montgomery, R; Protopopescu, D; Rosner, G; Seitz, B; Babai, M; Glazenborg-Kluttig, A; Kavatsyuk, M; Lemmens, P; Lindemulder, M; Löhner, H; Messchendorp, J; Moeini, H; Schakel, P; Schreuder, F; Smit, H; Tambave, G; Weele, J C van der; Veenstra\\inst, R; Sohlbach, H; Büscher, M; Deermann, D; Dosdall, R; Esch, S; Gillitzer, A; Goldenbaum, F; Grunwald, D; Henssler, S; Herten, A; Hu, Q; Kemmerling, G; Kleines, H; Kozlov, V; Lehrach, A; Maier, R; Mertens, M; Ohm, H; Orfanitski, S; Prasuhn, D; Randriamalala, T; Ritman, J; Schadmand, S; Serdyuk, V; Sterzenbach, G; Stockmanns, T; Wintz, P; Wüstner, P; Xu, H; Kisiel, J; Li, S; Li, Z; Sun, Z; Xu, H; Rigato, V; Fissum, S; Hansen, K; Isaksson, L; Lundin, M; Schröder, B; Achenbach, P; Bleser, S; Cahit, U; Cardinali, M; Denig, A; Distler, M; Fritsch, M; Kangh, D; Karavdina, A; Lauth, W; Merkel, H; Michel, M; Espi, M C Mora; Müller, U; Pochodzalla, J; Prometeusz, J; Sanchez, S; Sanchez-Lorente, A; Schlimme, S; Sfienti, C; Weber\\inst, M Thiel T; Dormenev, V I; Fedorov, A A; Korzhik, M V; Missevitch, O V; Balanutsa, V; Chernetsky, V; Demekhin, A; Dolgolenko, A; Fedorets, P; Gerasimov, A; Goryachev, V; Varentsov, V; Boukharov, A; Malyshev, O; Marishev, I; Semenov, A; Böhmer, F; Dørheim, S; Ketzer, B; Paul, S; Hergemöller, A K; Khoukaz, A; Köhler, E; Täschner, A; Wessels, J; Varma, R; Chaterjee, A; Jha, V; Kailas, S; Roy, B; Yan, Y; Chinorat, K; Khanchai, K; Ayut, L; Pomrad, S; Baldin, E; Kotov, K; Peleganchuk, S; Tikhonov, Yu; Boucher, J; Chambert, V; Dbeyssi, A; Hennino, T; Imre, M; Kunne, R; Galliard, C Le; Ma, B; Marchand, D; Maroni, A; Ong, S; Ramstein, B; Rosier, P; Sudol, M; Tomasi-Gustafsson, E; Wiele, J Van de; Boca, G; Braghieri, A; Costanza, S; Genova, P; Lavezzi, L; Montagna, P; Rotondi, A; Abramov, V; Belikov, N; Davidenko, A; Derevschikov, A; Goncharenko, Y; Grishin, V; Kachanov, V; Konstantinov, D; Kormilitsin, V; Melnik, Y; Levin, A; Minaev, N; Mochalov, V; Morozov, D; Nogach, L; Poslavskiy, S; Ryazantsev, A; Ryzhikov, S; Semenov, P; Shein, I; Uzunian, A; Vasiliev, A; Yakutin, A; Bäck, T; Cederwall, B; Makónyi, K; Tegnér, P E; Würtemberg, K M von; Belostotski, S; Gavrilov, G; Itzotov, A; Kashchuk, A; Kisselev, A; Kravchenko, P; Levitskaya, O; Manaenkov, S; Miklukho, O; Naryshkin, Y; Veretennikov, D; Vikhrov, V; Zhadanov, A; Alberto, D; Amoroso, A; Bussa, M P; Busso, L; Mori, F De; Destefanis, M; Fava, L; Ferrero, L; Greco, M; Maggiora, M; Marcello, S; Sosio, S; Spataro, S; Zotti, L; Calvo, D; Coli, S; Remigis, P De; Filippi, A; Giraudo, G; Lusso, S; Mazza, G; Morra, O; Rivetti, A; Wheadon, R; Iazzi, F; Lavagno, A; Younis, H; Birsa, R; Bradamante, F; Bressan, A; Martin, A; Clement, H; Galander, B; Balkestal, L Caldeira; Calén, H; Fransson, K; Johansson, T; Kupsc, A; Marciniewski, P; Thomé, E; Wolke, M; Zlomanczuk, J; Díaz, J; Ortiz, A; Dmowski, K; Korzeniewski, R; Przemyslaw, D; Slowinski, B; Chlopik, A; Guzik, Z; Kosinski, K; Melnychuk, D; Wasilewski, A; Wojciechowski, M; Wronka, S; Wysocka, A; Zwieglinski, B; Bühler, P; Hartman, O; Kienle, P; Marton, J; Suzuki, K; Widmann, E; Zmeskal, J

2012-01-01

This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM-stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy-loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole \\Panda scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.

Advanced Scale Conditioning Agent (ASCA) Applications: 2012 Experience Update

International Nuclear Information System (INIS)

Little, Michael-J.; Varrin, Robert-D.; Pellman, Aaron-T.; Kreider, Marc A.

2012-09-01

ASCAs are a group of dilute chemical treatments for removing deposited corrosion products from the secondary side of PWR steam generators (SGs). Each ASCA formulation is customized to achieve plant-specific goals that can include: - Partial dissolution and structural modification of the tube scale present on free span surfaces through full bundle treatment, lowering the deposit loading and enhancing SG thermal performance levels through creation of a scale structure marked by increased boiling efficiency, - Softening and partial removal of deposits present in the broached flow holes in the tube support plates, reducing the risks of level oscillations and flow-induced vibration (FIV), - Chemical removal of copper from tube scale and tube sheet deposits, reducing the risk of rapid tube corrosion caused by the oxidized conditions promoted by some copper species, and - Dissolution of hardness species from consolidated top-of-tube sheet (TTS) collars to enhance collar removal through water-jetting and other mechanical cleaning techniques. Regardless of the cleaning objectives for a particular plant, all ASCA processes are designed to minimize corrosion, waste disposal costs, and impact on the outage schedule. To date, about 40 ASCA applications have been carried out in four (4) countries. This paper provides an update of the industry experience gained during these applications, including results demonstrating the ability of ASCA processes to meet the goals outlined above. Experience at multiple units, including several repeat ASCA applications, has demonstrated significant heat-transfer benefits (i.e., steam pressure increases of up to 1-2 bar (15-30 psi)). ASCA applications also regularly achieve significant reductions in TSP blockage (i.e., up to 30% absolute increases in available flow area in broached flow holes) and have been successful in eliminating level oscillations caused by excessive broached-hole blockage. (authors)

Failure analysis of the boiler water-wall tube

Directory of Open Access Journals (Sweden)

S.W. Liu

2017-10-01

Full Text Available Failure analysis of the boiler water-wall tube is presented in this work. In order to examine the causes of failure, various techniques including visual inspection, chemical analysis, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy were carried out. Tube wall thickness measurements were performed on the ruptured tube. The fire-facing side of the tube was observed to have experienced significant wall thinning. The composition of the matrix material of the tube meets the requirements of the relevant standards. Microscopic examinations showed that the spheroidization of pearlite is not very obvious. The failure mechanism is identified as a result of the significant localized wall thinning of the boiler water-wall tube due to oxidation.

Catalyst-Assisted Manufacture of Olefins from Natural Gas liquids: Prototype Development and Full-Scale Testing

Energy Technology Data Exchange (ETDEWEB)

Keyvani, Majid [Lyondell Chemical Company, Houston, TX (United States); Ostroff, Craig [BASF Qtech Inc., Mississauga ON (Canada)

2015-09-01

The steam cracking of ethane to ethylene consumes the greatest amount energy of any process currently practiced by the US chemical industry. U.S. ethylene production consumed an estimated 450 trillion BTU of energy to produce nearly 53 billion pounds of ethylene in 2010. A significant portion of this energy consumption is to overcome the insulating effect of coke (carbonaceous deposits) on the internal surfaces of cracker furnace tubes. This buildup of coke is the result of both metal-catalyzed coke formation on the tube walls (“filamentous coke”), and deposition of gas-phase coke on the tube walls (“amorphous coke”). Coke buildup requires a continuous increase in energy input (firing of external coil tube wall) to achieve the same conversion of ethane feedstock to ethylene product, until the tubes must be taken out of service and the coke removed by steam treatment (“decoking”). This step interrupts production and increases the cost of ethylene. Coke buildup also shortens the coil life by increasing the rate of “creep” (sagging) that occurs due to higher temperature operation and migration of the deposited carbon into the coil metal.

Optimal Design and Model Validation for Combustion Experiments in a Shock Tube

KAUST Repository

Long, Quan

2014-01-06

We develop a Bayesian framework for the optimal experimental design of the shock tube experiments which are being carried out at the KAUST Clean Combustion Center. The unknown parameters are the pre-exponential parameters and the activation energies in the reaction rate functions. The control parameters are the initial hydrogen concentration and the temperature. First, we build a polynomial based surrogate model for the observable related to the reactions in the shock tube. Second, we use a novel MAP based approach to estimate the expected information gain in the proposed experiments and select the best experimental set-ups corresponding to the optimal expected information gains. Third, we use the synthetic data to carry out virtual validation of our methodology.

Performance evaluation of a full-scale advanced phase isolation ditch process by using real-time control strategies

International Nuclear Information System (INIS)

Kim, Hyosoo; Kim, Yejin; Kim, Minsoo; Piao, Wenhua; Kim, Changwon; Gee, Jeasung

2014-01-01

This paper proposes real-time control strategies that can be applied in a full-scale advanced phase isolation ditch (APID) process. Real-time operation mode control (OMC) and aeration section control (ASC) strategies were developed to cope more stably with fluctuations in the influent loading and to increase the nitrification and denitrification reactions within the entire volume. The real-time OMC and ASC strategies were evaluated using mathematical models. When the NH 4 -N in the reactor was maintained at a high level, appropriate control actions, such as continuing the aeration state, stopping the influent inflow and increasing the aeration section, were applied in the APID process. In contrast, when the NO X -N in the reactor was maintained at a high level, the non-aeration state, influent inflow, and decreased aeration section were continued. It was concluded that stable operation in the APID process could be achieved by applying real-time OMC and ASC strategies developed in this study

Performance evaluation of a full-scale advanced phase isolation ditch process by using real-time control strategies

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyosoo; Kim, Yejin; Kim, Minsoo; Piao, Wenhua; Kim, Changwon [Pusan National University, Busan (Korea, Republic of); Gee, Jeasung [Taiwha Industrial Co. Ltd., Seoul (Korea, Republic of)

2014-04-15

This paper proposes real-time control strategies that can be applied in a full-scale advanced phase isolation ditch (APID) process. Real-time operation mode control (OMC) and aeration section control (ASC) strategies were developed to cope more stably with fluctuations in the influent loading and to increase the nitrification and denitrification reactions within the entire volume. The real-time OMC and ASC strategies were evaluated using mathematical models. When the NH{sub 4}-N in the reactor was maintained at a high level, appropriate control actions, such as continuing the aeration state, stopping the influent inflow and increasing the aeration section, were applied in the APID process. In contrast, when the NO{sub X}-N in the reactor was maintained at a high level, the non-aeration state, influent inflow, and decreased aeration section were continued. It was concluded that stable operation in the APID process could be achieved by applying real-time OMC and ASC strategies developed in this study.

Scaling Hydrologic Exchange Flows and Biogeochemical Reactions from Bedforms to Basins

Science.gov (United States)

Harvey, J. W.; Gomez-Velez, J. D.

2015-12-01

River water moves in and out of the main channel along pathways that are perpendicular to the channel's main axis that flow across or beneath the ground surface. These hydrologic exchange flows (HEFs) are difficult to measure, yet no less important than a river's downstream flow, or exchanges with the atmosphere and deeper groundwater (Harvey and Gooseff, 2015, WRR). There are very few comprehensive investigations of exchange fluxes to understand patterns with river size and relative importance of specific types of exchanges. We used the physically based model NEXSS to simulate multiple scales of hyporheic flow and their cumulative effects on solute reaction in large basins (on the order of Chesapeake Bay basin or larger). Our goal was to explain where and when particular types of hyporheic flow are important in enhancing key biogeochemical reactions, such as organic carbon respiration and denitrification. Results demonstrate that hyporheic flux (expressed per unit area of streambed) varies surprisingly little across the continuum of first-order streams to eighth-order rivers, and vertical exchange beneath small bedforms dominates in comparison with lateral flow beneath gravel bars and meanders. Also, the river's entire volume is exchanged many times with hyporheic flow within a basin, and the turnover length (after one entire river volume is exchanged) is strongly influenced by hydrogeomorphic differences between physiographic regions as well as by river size. The cumulative effects on biogeochemical reactions were assessed using a the reaction significance factor, RSF, which computes the cumulative potential for hyporheic reactions using a dimensionless index that balances reaction progress in a single hyporheic flow path against overall processing efficiency of river turnover through hyporheic flow paths of that type. Reaction significance appears to be strongly dominated by hydrologic factors rather than biogeochemical factors, and seems to be dominated by

Design and performance of a full-scale spray calciner for nonradioactive high-level-waste-vitrification studies

International Nuclear Information System (INIS)

Miller, F.A.

1981-06-01

In the spray calcination process, liquid waste is spray-dried in a heated-wall spray dryer (termed a spray calciner), and then it may be combined in solid form with a glass-forming frit. This mixture is then melted in a continuous ceramic melter or in an in-can melter. Several sizes of spray calciners have been tested at PNL- laboratory scale, pilot scale and full scale. Summarized here is the experience gained during the operation of PNL's full-scale spray calciner, which has solidified approx. 38,000 L of simulated acid wastes and approx. 352,000 L of simulated neutralized wastes in 1830 h of processing time. Operating principles, operating experience, design aspects, and system descriptions of a full-scale spray calciner are discussed. Individual test run summaries are given in Appendix A. Appendices B and C are studies made by Bechtel Inc., under contract by PNL. These studies concern, respectively, feed systems for the spray calciner process and a spray calciner vibration analysis. Appendix D is a detailed structural analysis made at PNL of the spray calciner. These appendices are included in the report to provide a complete description of the spray calciner and to include all major studies made concerning PNL's full-scale spray calciner

Tube Thoracostomy: Complications and Its Management

Directory of Open Access Journals (Sweden)

Emeka B. Kesieme

2012-01-01

Full Text Available Background. Tube thoracostomy is widely used throughout the medical, surgical, and critical care specialities. It is generally used to drain pleural collections either as elective or emergency. Complications resulting from tube thoracostomy can occasionally be life threatening. Aim. To present an update on the complications and management of complications of tube thoracostomy. Methods. A review of the publications obtained from Medline search, medical libraries, and Google on tube thoracostomy and its complications was done. Results. Tube thoracostomy is a common surgical procedure which can be performed by either the blunt dissection technique or the trocar technique. Complication rates are increased by the trocar technique. These complications have been broadly classified as either technical or infective. Technical causes include tube malposition, blocked drain, chest drain dislodgement, reexpansion pulmonary edema, subcutaneous emphysema, nerve injuries, cardiac and vascular injuries, oesophageal injuries, residual/postextubation pneumothorax, fistulae, tumor recurrence at insertion site, herniation through the site of thoracostomy, chylothorax, and cardiac dysrhythmias. Infective complications include empyema and surgical site infection. Conclusion. Tube thoracostomy, though commonly performed is not without risk. Blunt dissection technique has lower risk of complications and is hence recommended.

Process Intensification of Alkynol Semihydrogenation in a Tube Reactor Coated with a Pd/ZnO Catalyst

Directory of Open Access Journals (Sweden)

Nikolay Cherkasov

2017-11-01

Full Text Available Semihydrogenation of 2-methyl-3-butyn-2-ol (MBY was studied in a 5 m tube reactor wall-coated with a 5 wt% Pd/ZnO catalyst. The system allowed for the excellent selectivity towards the intermediate alkene of 97.8 ± 0.2% at an ambient H2 pressure and a MBY conversion below 90%. The maximum alkene yield reached 94.6% under solvent-free conditions and 96.0% in a 30 vol % MBY aqueous solution. The reactor stability was studied for 80 h on stream with a deactivation rate of only 0.07% per hour. Such a low deactivation rate provides a continuous operation of one month with only a two-fold decrease in catalyst activity and a metal leaching below 1 parts per billion (ppb. The excellent turn-over numbers (TON of above 105 illustrates a very efficient utilisation of the noble metal inside catalyst-coated tube reactors. When compared to batch operation at 70 °C, the reaction rate in flow reactor can be increased by eight times at a higher reaction temperature, keeping the same product decomposition of about 1% in both cases.

Interaction between zircaloy tube and inconel spacer grid at high temperature

International Nuclear Information System (INIS)

Nagase, Fumihisa; Otomo, Takashi; Uetsuka, Hiroshi; Furuta, Teruo

1990-09-01

In order to investigate the interaction between fuel cladding and spacer grid of the pressurized water reactor during a severe accident, isothermal reaction tests were performed at the temperature range from 1248 to 1673K. A specimen consisted of a short Zircaloy-4 cladding tube and a piece of spacer grid of Inconel-718. In the tests in an argon atmosphere, eutectic reaction between Zircaloy and Inconel was observed at the contact points at 1248K. Rapid reaction was observed at higher test temperatures. For example, in the test at 1373K for 300s, Zircaloy reacted with Inconel over the entire thickness (0.62mm) of the tube in the vicinity of the contact point. In the present tests, Zircaloy which has higher melting point than Inconel was dissolved preferentially due to eutectic formation. In the tests in an oxygen atmosphere, no eutectic reaction was observed at temperatures below 1437K. A trace of interaction was found at the contact point of specimen heated at 1573 and 1623K. However, decrease in Zircaloy thickness was not measured. The possibility of eutectic reaction between Zircaloy cladding and Inconel spacer grid seems to be quite limited when sufficient oxygen is supplied. (author)

Multiaxial loading of large-diameter, thin-walled tube rock specimens

International Nuclear Information System (INIS)

Hecker, S.S.; Petrovic, J.J.

1981-01-01

A large-scale mechanical testing facility permits previously impossible thin-walled tube multiaxial loading experiments on rock materials. Constraints are removed regarding tube wall thickness in relation to rock microstructural features and tube diameter as well as test machine load capacity. Thin-walled tube studies clarify the influence of intermediate principal stress sigma 2 on rock fracture and help define a realistic rock fracture criterion for all multiaxial stressing situations. By comparing results of thin-walled and thick-walled tube fracture investigations, effects of stress gradients can be established. Finally, influence of stress path on rock fracture, an area largely ignored in current rock failure criteria, can be examined in detail using controlled loading changes as well as specimen prestrains

Full-scale demonstration of EBS construction technology I. Block, pellet and in-situ compaction method

International Nuclear Information System (INIS)

Toguri, Satohito; Asano, Hidekazu; Takao, Hajime; Matsuda, Takeshi; Amemiya, Kiyoshi

2008-01-01

(i) Bentonite Block: Applicability of manufacturing technology of buffer material was verified by manufacturing of full scale bentonite ring which consists of one-eight (1/8) dividing block (Outside Diameter (OD): 2.220 mm H: 300 mm). Density characteristic, dimension and scale effect, which were considered the tunnel environment under transportation, were evaluated. Vacuum suction technology was selected as handling technology for the ring. Hoisting characteristic of vacuum suction technology was presented through evaluation of the mechanical property of buffer material, the friction between blocks, etc. by using a full-scale bentonite ring (OD 2.200 mm, H 300 mm). And design of bentonite block and emplacement equipment were presented in consideration of manufacturability of the block, stability of handling and improvement of emplacement efficiency. (ii) Bentonite Pellet Filling: Basic characteristics such as water penetration, swelling and thermal conductivity of various kinds of bentonite pellet were collected by laboratory scale tests. Applicability of pellet filling technology was evaluated by horizontal filling test using a simulated full-scale drift tunnel (OD 2.200 mm, L 6 m) . Filling density, grain size distribution, etc. were also measured. (iii) In-Situ Compaction of Bentonite: Dynamic compaction method (heavy weight fall method) was selected as in-situ compaction technology. Compacting examination which used a full scale disposal pit (OD 2.360 mm) was carried out. Basic specification of compacting equipment and applicability of in-situ compaction technology were presented. Density, density distribution of buffer material and energy acted on the wall of the pit, were also measured. (author)

Effects of contrast agents on the fallopian tube in a rabbit model

International Nuclear Information System (INIS)

Moore, D.E.

1989-01-01

Selection of the optimal contrast agent for hysterosalpingography was the focus of this study. The authors have evaluated the effect of different iodinated contrast agents on the fallopian tube of a rabbit. Ethiodol (oil-soluble contrast agent), methylglucamine iothalomate (water-soluble ionic agent) 30% and 60%, and Ioxilan (water-soluble monionic contrast agent) were compared. The agents were introduced by fallopian tube catheterization. Findings suggested that nonionic water-soluble contrast agents were the least detrimental to the fallopian tube and surrounding tissue. Iothalomate 60% resulted in mild inflammatory changes. Oil-soluble contrast agents caused granulomatous reaction and fibrinous adhesions

Modal Techniques for Remote Identification of Nonlinear Reactions at Gap-Supported Tubes Under Turbulent Excitation

International Nuclear Information System (INIS)

Delaune, X.; Piteau, Ph.; Borsoi, L.; Antunes, J.; Debut, V.

2010-01-01

Predictive computation of the nonlinear dynamical responses of gap-supported tubes subjected to flow excitation has been the subject of very active research. Nevertheless, experimental results are still very important, for validation of the theoretical predictions as well as for asserting the integrity of field components. Because carefully instrumented test tubes and tube-supports are seldom possible, due to space limitations and to the severe environment conditions, there is a need for robust techniques capable of extracting, from the actual vibratory response data, information that is relevant for asserting the components integrity. The dynamical contact/impact (vibro-impact) forces are of paramount significance, as are the tube/support gaps. Following our previous studies in this area using wave-propagation techniques (De Araujo, Antunes, and Piteau, 1998, 'Remote Identification of Impact Forces on Loosely Supported Tubes: Part 1-Basic Theory and Experiments', J. Sound Vib., 215, pp. 1015-1041; Antunes, Paulino, and Piteau, 1998, 'Remote Identification of Impact Forces on Loosely Supported Tubes: Part 2-Complex Vibro-Impact Motions', J. Sound Vib., 215, pp. 1043-1064; Paulino, Antunes, and Izquierdo, 1999, 'Remote Identification of Impact Forces on Loosely Supported Tubes: Analysis of Multi-Supported Systems', ASME J. Pressure Vessel Technol., 121, pp. 61-70), we apply modal methods in the present paper for extracting such information. The dynamical support forces, as well as the vibratory responses at the support locations, are identified from one or several vibratory response measurements at remote transducers, from which the support gaps can be inferred. As for most inverse problems, the identification results may prove quite sensitive to noise and modeling errors. Therefore, topics discussed in the paper include regularization techniques to mitigate the effects of non-measured noise perturbations. In particular, a method is proposed to improve the

21 CFR 868.5800 - Tracheostomy tube and tube cuff.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5800 Tracheostomy tube and tube cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into a...

Flash photolysis-shock tube studies

Energy Technology Data Exchange (ETDEWEB)

Michael, J.V. [Argonne National Laboratory, IL (United States)

1993-12-01

Even though this project in the past has concentrated on the measurement of thermal bimolecular reactions of atomic species with stable molecules by the flash or laser photolysis-shock tube (FP- or LP-ST) method using atomic resonance absorption spectrometry (ARAS) as the diagnostic technique, during the past year the authors have concentrated on studies of the thermal decompositions of selected chlorocarbon molecules. These studies are necessary if the degradation of chlorine containing organic molecules by incineration are to be understood at the molecular level. Clearly, destruction of these molecules will not only involve abstraction reactions, when possible, but also thermal decomposition followed by secondary reactions of the initially formed atoms and radicals. Studies on the thermal decomposition of CH{sub 3}Cl are complete, and the curve-of-growth for Cl-atom atomic resonance absorption has been determined. The new thermal decomposition studies are similar to those already reported for CH{sub 3}Cl.

Large-leak sodium-water reaction analysis for steam generators

International Nuclear Information System (INIS)

Sakano, K.; Shindo, Y.; Hori, M.

1975-01-01

The guillotine rupture of 4 tubes is assumed as a design basis regarding the large-leak sodium-water reaction in the system of the MONJU steam generator. Three kinds of analyses were performed with the view to showing the integrity of the steam generator system on the reaction. The first one is the analysis of the initial pressure spike, assuming the initial guillotine rupture of 1 tube. The analysis was performed by utilizing one-dimensional sphere-cylinder model code SWAC-7 and two-dimensional axisymmetric code PISCES 2DL. The second one is the analysis of the secondary peak pressure and its propagation in the system, assuming the instantaneous guillotine rupture of 4 tubes. The third one is the analysis of the dynamic deformation of the steam generator shell. The integrity of the steam generator system was shown by the analyses. (author)

Large-leak sodium-water reaction analysis for steam generators

Energy Technology Data Exchange (ETDEWEB)

Sakano, K; Shindo, Y; Hori, M

1975-07-01

The guillotine rupture of 4 tubes is assumed as a design basis regarding the large-leak sodium-water reaction in the system of the MONJU steam generator. Three kinds of analyses were performed with the view to showing the integrity of the steam generator system on the reaction. The first one is the analysis of the initial pressure spike, assuming the initial guillotine rupture of 1 tube. The analysis was performed by utilizing one-dimensional sphere-cylinder model code SWAC-7 and two-dimensional axisymmetric code PISCES 2DL. The second one is the analysis of the secondary peak pressure and its propagation in the system, assuming the instantaneous guillotine rupture of 4 tubes. The third one is the analysis of the dynamic deformation of the steam generator shell. The integrity of the steam generator system was shown by the analyses. (author)

Tube plug

International Nuclear Information System (INIS)

Zafred, P. R.

1985-01-01

The tube plug comprises a one piece mechanical plug having one open end and one closed end which is capable of being inserted in a heat exchange tube and internally expanded into contact with the inside surface of the heat exchange tube for preventing flow of a coolant through the heat exchange tube. The tube plug also comprises a groove extending around the outside circumference thereof which has an elastomeric material disposed in the groove for enhancing the seal between the tube plug and the tube

Setup of Extruded Cementitious Hollow Tubes as Containing/Releasing Devices in Self-Healing Systems

Directory of Open Access Journals (Sweden)

Alessandra Formia

2015-04-01

Full Text Available The aim of this research is to produce self-healing cementitious composites based on the use of cylindrical capsules containing a repairing agent. Cementitious hollow tubes (CHT having two different internal diameters (of 2 mm and 7.5 mm were produced by extrusion and used as containers and releasing devices for cement paste/mortar healing agents. Based on the results of preliminary mechanical tests, sodium silicate was selected as the healing agent. The morphological features of several mix designs used to manufacture the extruded hollow tubes, as well as the coatings applied to increase the durability of both core and shell materials are discussed. Three-point bending tests were performed on samples produced with the addition of the above-mentioned cementitious hollow tubes to verify the self-healing effectiveness of the proposed solution. Promising results were achieved, in particular when tubes with a bigger diameter were used. In this case, a substantial strength and stiffness recovery was observed, even in specimens presenting large cracks (>1 mm. The method is inexpensive and simple to scale up; however, further research is needed in view of a final optimization.

Ultrasonic inspection of tube to tube plate welds

International Nuclear Information System (INIS)

Telford, D.W.; Peat, T.S.

1985-01-01

To monitor the deterioration of a weld between a tube and tube plate which has been repaired by a repair sleeve inside the tube and brazed at one end to the tube, ultrasound from a crystal at the end of a rod is launched, in the form of Lamb-type waves, into the tube through the braze and allowed to travel along the tube to the weld and be reflected back along the tube. The technique may also be used for the type of heat exchanger in which, during construction, the tubes are welded to the tube plate via external sleeves in which case the ultrasound is used in a similar manner to inspect the sleeve/tube plate weld. an electromagnetic transducer may be used to generate the ultrasound. The ultrasonic head comprising the crystal and an acoustic baffle is mounted on a Perspex (RTM) rod which may be rotated by a stepping motor. Echo signals from the region of deterioration may be isolated by use of a time gate in the receiver. The device primarily detects circumferentially orientated cracks, and may be used in heat exchangers in nuclear power plants. (author)

A shock tube and laser absorption study of ignition delay times and OH reaction rates of ketones: 2-Butanone and 3-buten-2-one

KAUST Repository

Badra, Jihad

2014-03-01

Ketones are potential biofuel candidates and are also formed as intermediate products during the oxidation of large hydrocarbons or oxygenated fuels, such as alcohols and esters. This paper presents shock tube ignition delay times and OH reaction rates of 2-butanone (C2H5COCH3) and 3-buten-2-one (C2H3COCH3). Ignition delay measurements were carried out over temperatures of 1100-1400K, pressures of 3-6.5atm, and at equivalence ratios (F{cyrillic}) of 0.5 and 1. Ignition delay times were monitored using two different techniques: pressure time history and OH absorption near 306nm. The reaction rates of hydroxyl radicals (OH) with these two ketones were measured over the temperature range of 950-1400K near 1.5atm. The OH profiles were monitored by the narrow-line-width ring-dye laser absorption of the well-characterized R1(5) line in the OH A-X (0, 0) band near 306.69nm. We found that the ignition delay times of 2-butanone and 3-buten-2-one mixtures scale with pressure as P-0.42 and P-0.52, respectively. The ignition delay times of 3-buten-2-one were longer than that of 2-butanone for stoichiometric mixtures, however, for lean mixtures (F{cyrillic}=0.5), 2-butanone had longer ignition delay times. The chemical kinetic mechanism of Serinyel et al. [1] over-predicted the ignition delay times of 2-butanone at all tested conditions, however, the discrepancies were smaller at higher pressures. The mechanism was updated with recent rate measurements to decrease discrepancy with the experimental data. A detailed chemistry for the oxidation of 3-buten-2-one was developed using rate estimation method and reasonable agreements were obtained with the measured ignition delay data. The measured reaction rate of 2-butanone with OH agreed well with the literature data, while we present the first high-temperature measurements for the reaction of OH with 3-buten-2-one. The following Arrhenius expressions are suggested over the temperature range of 950-1450K: kC2H5COCH3+OH=6.78×1013exp

Development of a highly sensitive one-tube nested real-time PCR for detecting Mycobacterium tuberculosis.

Science.gov (United States)

Choi, Yeonim; Jeon, Bo-Young; Shim, Tae Sun; Jin, Hyunwoo; Cho, Sang-Nae; Lee, Hyeyoung

2014-12-01

Rapid, accurate detection of Mycobacterium tuberculosis is crucial in the diagnosis of tuberculosis (TB), but conventional diagnostic methods have limited sensitivity and specificity or are time consuming. A new highly sensitive nucleic acid amplification test, combined nested and real-time polymerase chain reaction (PCR) in a single tube (one-tube nested real-time PCR), was developed for detecting M. tuberculosis, which takes advantage of two PCR techniques, i.e., nested PCR and real-time PCR. One-tube nested real-time PCR was designed to have two sequential reactions with two sets of primers and dual probes for the insertion sequence (IS) 6110 sequence of M. tuberculosis in a single closed tube. The minimum limits of detection of IS6110 real-time PCR and IS6110 one-tube nested real-time PCR were 100 fg/μL and 1 fg/μL of M. tuberculosis DNA, respectively. AdvanSure TB/non-tuberculous mycobacteria (NTM) real-time PCR, IS6110 real-time PCR, and two-tube nested real-time PCR showed 100% sensitivity and 100% specificity for clinical M. tuberculosis isolates and NTM isolates. In comparison, the sensitivities of AdvanSure TB/NTM real-time PCR, single IS6110 real-time PCR, and one-tube nested real-time PCR were 91% (152/167), 94.6% (158/167), and 100% (167/167) for sputum specimens, respectively. In conclusion, IS6110 one-tube nested real-time PCR is useful for detecting M. tuberculosis due to its high sensitivity and simple manipulation. Copyright © 2014 Elsevier Inc. All rights reserved.

Dynamic radar cross section measurements of a full-scale aircraft for RCS modelling validation

CSIR Research Space (South Africa)

Van Schalkwyk, Richard F

2017-10-01

Full Text Available In this paper the process followed in generating a high fidelity reference data set for radar cross section (RCS) modelling validation for a full-scale aircraft, is presented. An overview of two dynamic RCS measurement campaigns, involving both...

An experimental study on impingement wastage of Mod 9Cr 1Mo steel due to sodium water reaction

Energy Technology Data Exchange (ETDEWEB)

Kishore, S., E-mail: skishore@igcar.gov.in [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Ashok Kumar, A.; Chandramouli, S.; Nashine, B.K.; Rajan, K.K.; Kalyanasundaram, P.; Chetal, S.C. [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

2012-02-15

Highlights: Black-Right-Pointing-Pointer Sodium heated steam generators are crucial components of fast breeder reactors. Black-Right-Pointing-Pointer A leak in steam generator tube will cause sodium water reaction that damages the tubes. Black-Right-Pointing-Pointer Experimental study was conducted to quantify the extent of damage on Mod 9Cr 1Mo tube due to a water leak. - Abstract: Sodium heated steam generator (SG) is a crucial component in the heat transport system of a fast breeder reactor (FBR). In case, one of its water/steam carrying tubes becomes defective, water/steam leaks into sodium, flowing in the shell side, causing sodium-water reaction, which is highly exothermic and producing corrosive NaOH. The reaction jet originating from a leaking tube may impinge on its adjacent tube, resulting in damage of the tube. Impingement wastage refers to this kind of damage, occurring to a tube of sodium heated SG, owing to a small water/steam leak from a neighboring tube. Extensive research works have been conducted all over the world to study various aspects of this phenomenon. Experimental studies were carried out in Indira Gandhi Centre for Atomic Research (IGCAR) to understand the effect of impingement wastage on Mod 9Cr 1Mo, which is the tube material of prototype fast breeder reactor (PFBR) SG. This paper brings out the data and experience gained through the experiments.

PEG Tube Placement

Directory of Open Access Journals (Sweden)

Saptarshi Biswas

2014-01-01

Full Text Available Percutaneous endoscopic gastrostomy (PEG has been used for providing enteral access to patients who require long-term enteral nutrition for years. Although generally considered safe, PEG tube placement can be associated with many immediate and delayed complications. Buried bumper syndrome (BBS is one of the uncommon and late complications of percutaneous endoscopic gastrostomy (PEG placement. It occurs when the internal bumper of the PEG tube erodes into the gastric wall and lodges itself between the gastric wall and skin. This can lead to a variety of additional complications such as wound infection, peritonitis, and necrotizing fasciitis. We present here a case of buried bumper syndrome which caused extensive necrosis of the anterior abdominal wall.

The effect of primary sedimentation on full-scale WWTP nutrient removal performance.

Science.gov (United States)

Puig, S; van Loosdrecht, M C M; Flameling, A G; Colprim, J; Meijer, S C F

2010-06-01

Traditionally, the performance of full-scale wastewater treatment plants (WWTPs) is measured based on influent and/or effluent and waste sludge flows and concentrations. Full-scale WWTP data typically have a high variance which often contains (large) measurement errors. A good process engineering evaluation of the WWTP performance is therefore difficult. This also makes it usually difficult to evaluate effect of process changes in a plant or compare plants to each other. In this paper we used a case study of a full-scale nutrient removing WWTP. The plant normally uses presettled wastewater, as a means to increase the nutrient removal the plant was operated for a period by-passing raw wastewater (27% of the influent flow). The effect of raw wastewater addition has been evaluated by different approaches: (i) influent characteristics, (ii) design retrofit, (iii) effluent quality, (iv) removal efficiencies, (v) activated sludge characteristics, (vi) microbial activity tests and FISH analysis and, (vii) performance assessment based on mass balance evaluation. This paper demonstrates that mass balance evaluation approach helps the WWTP engineers to distinguish and quantify between different strategies, where others could not. In the studied case, by-passing raw wastewater (27% of the influent flow) directly to the biological reactor did not improve the effluent quality and the nutrient removal efficiency of the WWTP. The increase of the influent C/N and C/P ratios was associated to particulate compounds with low COD/VSS ratio and a high non-biodegradable COD fraction. Copyright 2010 Elsevier Ltd. All rights reserved.

Tube spacer grid for a heat-exchanger tube bundle

International Nuclear Information System (INIS)

Scheidl, H.

1976-01-01

A tube spacer grid for a heat-exchanger tube bundle is formed by an annular grid frame having a groove formed in its inner surface in which the interspaced grid bars have their ends positioned and held in interspaced relationship by short sections of tubes passed through holes axially formed in the grid frame so that the tubes are positioned between the ends of the grid bars in the grooves. The tube sections may be cut from the same tubes used to form the tube bundle. 5 claims, 3 drawing figures

Simple biogas desulfurization by microaeration - Full scale experience.

Science.gov (United States)

Jeníček, P; Horejš, J; Pokorná-Krayzelová, L; Bindzar, J; Bartáček, J

2017-08-01

Hydrogen sulfide in biogas is common problem during anaerobic treatment of wastewater with high sulfate concentration (breweries, distilleries, etc.) and needs to be removed before biogas utilization. Physico-chemical desulfurization methods are energetically demanding and expensive compare to biochemical methods. Microaeration, i.e. dosing of small amount of air, is suitable and cost effective biochemical method of sulfide oxidation to elemental sulfur. It has been widely used in biogas plants, but its application in anaerobic reactors for wastewater treatment has been rarely studied or tested. The lack of full-scale experience with microaeration in wastewater treatment plants has been overcome by evaluating the results of seven microaerobic digesters in central Europe. The desulfurization efficiency has been more than 90% in most of the cases. Moreover, microaeration improved the degradability of COD and volatile suspended solids. Copyright © 2017 Elsevier Ltd. All rights reserved.

The shock tube as wave reactor for kinetic studies and material systems

Energy Technology Data Exchange (ETDEWEB)

Bhaskaran, K.A. [Indian Institute of Technology, Chennai (India). Department of Mechanical Engineering; Roth, P. [Gerhard Mercator Universitat, Duisberg (Germany). Institut fur Verbrennung und Gasdynamik

2002-07-01

Several important reviews of shock tube kinetics have appeared earlier, prominent among them being 'Shock Tube Technique in Chemical Kinetics' by Belford and Strehlow (Ann Rev Phys Chem 20 (1969) 247), 'Chemical Reaction of Shock Waves' by Wagner (Proceedings of the Eighth International Shock Tube Symposium (1971) 4/1), 'Shock Tube and Shock Wave Research' by Bauer and Lewis (Proceedings of the 11th International Symposium on Shock Tubes and Waves (1977) 269), 'Shock Waves in Chemistry' edited by Assa Lifshitz (Shock Waves in Chemistry, 1981) and 'Shock Tube Techniques in Chemical Kinetics' by Wing Tsang and Assa Lifshitz (Annu Rev Phys Chem 41 (1990) 559). A critical analysis of the different shock tube techniques, their limitations and suggestions to improve the accuracy of the data produced are contained in these reviews. The purpose of this article is to present the current status of kinetic research with emphasis on the diagnostic techniques. Selected studies on homogeneous and dispersed systems are presented to bring out the versatility of the shock tube technique. The use of the shock tube as high temperature wave reactor for gas phase material synthesis is also highlighted. (author)

Database of full-scale laboratory experiments on wave-driven sand transport processes

NARCIS (Netherlands)

van der Werf, Jebbe J.; Schretlen, Johanna Lidwina Maria; Ribberink, Jan S.; O'Donoghue, Tom

2009-01-01

A new database of laboratory experiments involving sand transport processes over horizontal, mobile sand beds under full-scale non-breaking wave and non-breaking wave-plus-current conditions is described. The database contains details of the flow and bed conditions, information on which quantities

Regeneration of Exhausted Arsenic Adsorptive media of a Full Scale Treatment System

Science.gov (United States)

This presentation will describe the method and results of laboratory tests showing the feasibility of regenerating exhausted, iron-based, adsorptive media and the results of a follow up regeneration test at a full scale system in Twentynine Palms CA. The laboratory studies on se...

YouTube and Video Quizzes

Directory of Open Access Journals (Sweden)

Kevin YEE

2010-04-01

Full Text Available The Internet sensation YouTube (http://www.youtube.com has become such a force online that it was estimated in 2006 to account for a full tenth of the bandwidth by the entire Internet in the United States (WebProNews, 2007, and to use as much bandwidth in 2007 as the entire Internet had done in 2000 (Carter, 2008. Like many technological tools created with entertainment or profit in mind, YouTube can now be easily and usefully adopted by instructors for educational purposes, and indeed many professors use YouTube in their classroom teaching already (Brooks, 2000. This is especially true for passive uses of YouTube; watching videos that are already online and using them in the classroom experience to support a concept and provide another mechanism for students to connect with the topics. It is fruitful to consider Bloom's Taxonomy of Educational Objectives (Bloom & Krathwohl, 1956 when employing video or any media in the classroom to maximize the intentionality of teaching and learning. The use of video for demonstration or modeling corresponds well to Blooms levels of Knowledge, Comprehension, and Application; while case studies offer a chance to demonstrate Analysis and Synthesis, and perhaps even Evaluation, when comparing a video to information from a text book or other content.

Development of tube rupture evaluation code for FBR steam generator (II). Modification of heat transfer model in sodium side

International Nuclear Information System (INIS)

Hamada, H.; Kurihara, A.

2003-05-01

The thermal effect of sodium-water reaction jet on neighboring heat transfer tubes was examined to rationally evaluate the structural integrity of the tube for overheating rupture under a water leak in an FBR steam generator. Then, the development of new heat transfer model and the application analysis were carried out. Main results in this paper are as follows. (1) The evaluation method of heat flux and heat transfer coefficient (HTC) on the tube exposed to reaction jet was developed. By using the method, it was confirmed that the heat flux could be realistically evaluated in comparison with the previous method. (2) The HTC between reaction jet and the tube was theoretically examined in the two-phase flow model, and new heat transfer model considering the effect of fluid temperature and cover gas pressure was developed. By applying the model, a tentative experimental correlation was conservatively obtained by using SWAT-1R test data. (3) The new model was incorporated to the Tube Rupture Evaluation Code (TRUE), and the conservatism of the model was confirmed by using sodium-water reaction data such as the SWAT-3 tests. (4) In the application analysis of the PFR large leak event, there was no significant difference of calculation results between the new model and previous one; the importance of depressurization in the tube was confirmed. (5) In the application analysis of the Monju evaporator, it was confirmed that the calculation result in the previous model would be more conservative than that in the new one and that the maximum cumulative damage of 25% could be reduced in the new model. (author)

Failure investigation of a secondary super heater tube in a 140 MW thermal power plant

Directory of Open Access Journals (Sweden)

Atanu Saha

2017-04-01

Full Text Available This article describes the findings of a detailed investigation into the failure of a secondary super heater tube in a 140 MW thermal power plant. Preliminary macroscopic examinations along with visual examination, dimensional measurement and chemical analysis were carried out to deduce the probable cause of failure. In addition optical microscopy was a necessary supplement to understand the cause of failure. It was concluded that the tube had failed due to severe creep damage caused by high metal temperature during service. The probable causes of high metal temperature may be in sufficient flow of steam due to partial blockage, presence of thick oxide scale on ID surface, high flue gas temperature etc. rupture.

A Study on Thermal Performance of a Novel All-Glass Evacuated Tube Solar Collector Manifold Header with an Inserted Tube

Directory of Open Access Journals (Sweden)

Jichun Yang

2015-01-01

Full Text Available A novel all-glass evacuated tube collector manifold header with an inserted tube is proposed in this paper which makes water in all-glass evacuated solar collector tube be forced circulated to improve the performance of solar collector. And a dynamic numerical model was presented for the novel all-glass evacuated tube collector manifold header water heater system. Also, a test rig was built for model validation and comparison with traditional all-glass evacuated tube collector. The experiment results show that the efficiency of solar water heater with a novel collector manifold header is higher than traditional all-glass evacuated tube collector by about 5% and the heat transfer model of water heater system is valid. Based on the model, the relationship between the average temperature of water tank and inserted tube diameter (water mass flow has been studied. The results show that the optimized diameter of inserted tube is 32 mm for the inner glass with the diameter of 47 mm and the water flow mass should be less than 1.6 Kg/s.

Radiant absorption characteristics of corrugated curved tubes

Directory of Open Access Journals (Sweden)

Đorđević Milan Lj.

2017-01-01

Full Text Available The utilization of modern paraboloidal concentrators for conversion of solar radiation into heat energy requires the development and implementation of compact and efficient heat absorbers. Accurate estimation of geometry influence on absorption characteristics of receiver tubes is an important step in this process. This paper deals with absorption characteristics of heat absorber made of spirally coiled tubes with transverse circular corrugations. Detailed 3-D surface-to-surface Hemicube method was applied to compare radiation performances of corrugated and smooth curved tubes. The numerical results were obtained by varying the tube curvature ratio and incident radiant heat flux intensity. The details of absorption efficiency of corrugated tubes and the effect of curvature on absorption properties for both corrugated and smooth tubes were presented. The results may have significance to further analysis of highly efficient heat absorbers exposed to concentrated radiant heating. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 42006

Transcriptome analysis of tube foot and large scale marker discovery in sea cucumber, Apostichopus japonicus.

Science.gov (United States)

Zhou, Xiaoxu; Wang, Hongdi; Cui, Jun; Qiu, Xuemei; Chang, Yaqing; Wang, Xiuli

2016-12-01

Tube foot as one of the ambulacral appendages types in Aspidochirote holothurioids, is known for their functions in locomotion, feeding, chemoreception, light sensitivity and respiration. In this study, we explored the characteristic of transcriptome in the tube foot of sea cucumber (Apostichopus japonicus). Our results showed that among 390 unigenes which specifically expressed in the tube foot, 190 of them were annotated. Based on the assembly transcriptome, we found 219,860 SNPs from 34,749 unigenes, 97,683, 53,624, 27,767 and 40,786 were located in CDSs, 5'-UTRs, 3'-UTRs and non-CDS separately. Furthermore, 12,114 SSRs were detected from 7394 unigenes. Target genes of four specifically expressed miRNAs (miR-29a, miR-29b, miR-278-3p and miR-2005) in tube foot were also predicted based on the transcriptome, which contain immune-related factors (MBL, VLRA, AjC3, MyD88, CFB), skin pigmentation (MITF), candidate regeneration factor (TRP) and holothurians autolysis-related factor (CL). These results develop a relatively large number of molecular markers and transcriptome resources, and will provide a foundation for further analyses on the function and molecular mechanisms underlying A. japonicas tube foot. Copyright © 2016 Elsevier Inc. All rights reserved.

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SPES-2, the full-height, full-pressure, test facility simulating the AP600 plant: Main results from the experimental campaign

International Nuclear Information System (INIS)

Medich, C.; Rigamonti, M.; Martinelli, R.; Tarantini, M.; Conway, L.

1995-01-01

The SPES-2 is a full height, full pressure experimental test facility reproducing the Westinghouse AP600 reactor with a scaling factor of 1/395. The experimental plant, designed and operated by SIET in Piacenza, consists of a full simulation of the AP600 primary core cooling system including all the passive and active safety systems. In 1992, Westinghouse, in cooperation with ENEL, ENEA, SIET and ANSALDO developed an experimental program to test the integrated behavior of the AP600 passive safety systems. The SPES-2 test matrix, concluded in November 1994, has examined the AP600 passive safety system response for a range of small break LOCAs at different locations on the primary system and on the passive system lines; single steam generator tube ruptures with both passive and active non-safety systems, and a main steam line break transient to demonstrate the capability of passive safety systems for rapid cooldown. Each of the tests has provided detailed experimental results for verification of the capability of the analysis methods to predict the integrated passive safety system behavior

Evaluation of the Effect of Tube Pitch and Surface Alterations on Temperature Field at Sprinkled Tube Bundle

Directory of Open Access Journals (Sweden)

Kracík Petr

2015-01-01

Full Text Available Water flowing on a sprinkled tube bundle forms three basic modes: It is the Droplet mode (liquid drips from one tube to another, the Jet mode (with an increasing flow rate droplets merge into a column and the Membrane (Sheet mode (with further increasing of falling film liquid flow rate columns merge and create sheets between the tubes. With sufficient flow rate sheets merge at this state and the tube bundle is completely covered by a thin liquid film. There are several factors influencing the individual mode types as well as heat transfer. Beside the above mentioned falling film liquid flow rate they are for instance tube diameters, tube pitches in a tube bundle or a physical condition of a falling film liquid. This paper presents a summary of data measured at atmospheric pressure at a tube bundle consisting of copper tubes of 12 milimeters diameter and of the studied tube length one meter. The tubes are positioned horizontally one above another with the tested pitches of 15, 20, 25 and 30 mm and there is a distribution tube placed above them with water flowing out. The thermal gradient of 15–40 has been tested with all pitches where the falling film liquid’s temperature at the inlet of the distribution tube was 15 °C. The liquid was heated during the flow through the exchanger and the temperature of the sprinkled (heater liquid at the inlet of the exchanger with a constant flow rate about 7.2 litres per minute was 40 °C. The tested flow of the falling film liquid ranged from 1.0 to 13.0 litres per minute. Sequences of 180 exposures have been recorded in partial flow rate stages by thermographic camera with record frequency of 30 Hz which were consequently assessed using the Matlab programme. This paper presents results achieved at the above mentioned pitches and at three types of tube bundle surfaces.

Computer simulation of the fire-tube boiler hydrodynamics

Directory of Open Access Journals (Sweden)

Khaustov Sergei A.

2015-01-01

Full Text Available Finite element method was used for simulating the hydrodynamics of fire-tube boiler with the ANSYS Fluent 12.1.4 engineering simulation software. Hydrodynamic structure and volumetric temperature distribution were calculated. The results are presented in graphical form. Complete geometric model of the fire-tube boiler based on boiler drawings was considered. Obtained results are suitable for qualitative analysis of hydrodynamics and singularities identification in fire-tube boiler water shell.

HRP facility for fabrication of ITER vertical target divertor full scale plasma facing units

International Nuclear Information System (INIS)

Visca, Eliseo; Roccella, S.; Candura, D.; Palermo, M.; Rossi, P.; Pizzuto, A.; Sanguinetti, G.P.; Mancini, A.; Verdini, L.; Cacciotti, E.; Cerri, V.; Mugnaini, G.; Reale, A.; Giacomi, G.

2015-01-01

Highlights: • R&D activities for the manufacturing of ITER divertor high heat flux plasma-facing components (HHFC). • ENEA and Ansaldo have jointly manufactured several actively cooled monoblock mock-ups and prototypical components. • ENEA and ANSALDO NUCLEARE jointly participate to the European program for the qualification of the manufacturing technology for the ITER divertor IVT. • Successful manufacturing by HRP (Hot Radial Pressing) of first full-scale full-W armored IVT qualification prototype. - Abstract: ENEA and Ansaldo Nucleare S.p.A. (ANN) have being deeply involved in the European development activities for the manufacturing of the ITER Divertor Inner Vertical Target (IVT) plasma-facing components. During normal operation the heat flux deposited on the bottom segment of divertor is 5–10 MW/m 2 but the capability to remove up to 20 MW/m 2 during transient events of 10 s must also be demonstrated. In order to fulfill ITER requirements, ENEA has set up and widely tested a manufacturing process, named Hot Radial Pressing (HRP). The last challenge is now to fabricate full-scale prototypes of the IVT, aimed to be qualified for the next step, i.e. the series production. On the basis of the experience of manufacturing hundreds of small mock-ups, ENEA designed and installed a new suitable HRP facility. The objective of getting a final shaped plasma facing unit (PFU) that satisfies these requirements is an ambitious target because tolerances set by ITER/F4E are very tight. The setting-up of the equipment started with the fabrication of full scale and representative ‘dummies’ in which stainless steel instead of CFC or W was used for monoblocks. The results confirmed that dimensions were compliant with the required tolerances. The paper reports a brief description of the innovative HRP equipment and the dimensional check results after HRP of the first full-scale full-W PFU.

HRP facility for fabrication of ITER vertical target divertor full scale plasma facing units

Energy Technology Data Exchange (ETDEWEB)

Visca, Eliseo, E-mail: eliseo.visca@enea.it [Unità Tecnica Fusione, ENEA C. R. Frascati, via E. Fermi 45, IT-00044 Frascati (Roma) (Italy); Roccella, S. [Unità Tecnica Fusione, ENEA C. R. Frascati, via E. Fermi 45, IT-00044 Frascati (Roma) (Italy); Candura, D.; Palermo, M. [Ansaldo Nucleare S.p.A., Corso Perrone 25, IT-16152 Genova (Italy); Rossi, P.; Pizzuto, A. [Unità Tecnica Fusione, ENEA C. R. Frascati, via E. Fermi 45, IT-00044 Frascati (Roma) (Italy); Sanguinetti, G.P. [Ansaldo Nucleare S.p.A., Corso Perrone 25, IT-16152 Genova (Italy); Mancini, A.; Verdini, L.; Cacciotti, E.; Cerri, V.; Mugnaini, G.; Reale, A.; Giacomi, G. [Unità Tecnica Fusione, ENEA C. R. Frascati, via E. Fermi 45, IT-00044 Frascati (Roma) (Italy)

2015-10-15

Highlights: • R&D activities for the manufacturing of ITER divertor high heat flux plasma-facing components (HHFC). • ENEA and Ansaldo have jointly manufactured several actively cooled monoblock mock-ups and prototypical components. • ENEA and ANSALDO NUCLEARE jointly participate to the European program for the qualification of the manufacturing technology for the ITER divertor IVT. • Successful manufacturing by HRP (Hot Radial Pressing) of first full-scale full-W armored IVT qualification prototype. - Abstract: ENEA and Ansaldo Nucleare S.p.A. (ANN) have being deeply involved in the European development activities for the manufacturing of the ITER Divertor Inner Vertical Target (IVT) plasma-facing components. During normal operation the heat flux deposited on the bottom segment of divertor is 5–10 MW/m{sup 2} but the capability to remove up to 20 MW/m{sup 2} during transient events of 10 s must also be demonstrated. In order to fulfill ITER requirements, ENEA has set up and widely tested a manufacturing process, named Hot Radial Pressing (HRP). The last challenge is now to fabricate full-scale prototypes of the IVT, aimed to be qualified for the next step, i.e. the series production. On the basis of the experience of manufacturing hundreds of small mock-ups, ENEA designed and installed a new suitable HRP facility. The objective of getting a final shaped plasma facing unit (PFU) that satisfies these requirements is an ambitious target because tolerances set by ITER/F4E are very tight. The setting-up of the equipment started with the fabrication of full scale and representative ‘dummies’ in which stainless steel instead of CFC or W was used for monoblocks. The results confirmed that dimensions were compliant with the required tolerances. The paper reports a brief description of the innovative HRP equipment and the dimensional check results after HRP of the first full-scale full-W PFU.

On the dominant noise components of tactical aircraft: Laboratory to full scale

Science.gov (United States)

Tam, Christopher K. W.; Aubert, Allan C.; Spyropoulos, John T.; Powers, Russell W.

2018-05-01

This paper investigates the dominant noise components of a full-scale high performance tactical aircraft. The present study uses acoustic measurements of the exhaust jet from a single General Electric F414-400 turbofan engine installed in a Boeing F/A-18E Super Hornet aircraft operating from flight idle to maximum afterburner. The full-scale measurements are to the ANSI S12.75-2012 standard employing about 200 microphones. By comparing measured noise spectra with those from hot supersonic jets observed in the laboratory, the dominant noise components specific to the F/A-18E aircraft at different operating power levels are identified. At intermediate power, it is found that the dominant noise components of an F/A-18E aircraft are essentially the same as those of high temperature supersonic laboratory jets. However, at military and afterburner powers, there are new dominant noise components. Their characteristics are then documented and analyzed. This is followed by an investigation of their origin and noise generation mechanisms.

Development and test evaluation of duplex steam reformer tube

International Nuclear Information System (INIS)

Allen, D.C.; Meyer, D.J.; Pflasterer, G.R.

1980-01-01

For HTR applications involving a steam reformer (SR), it is uncertain whether an intermediate heat exchanger (IHX) is required. There are several system configurations that could be developed for the application of nuclear heat using the steam reformer reaction. The considerations (advantages vs. disadvantages) for each of the system configurations are summarized. The approach that technically and economically appears to be the most attractive, in studies conducted by General Electric, combines the SR process heat exchanger and the IHX in a single component using a duplex tube. A central question concerning the duplex tube concept is whether the design would provide adequate leak monitoring capability and significant reduction in tritium and hydrogen diffusion, while introducing only a small increase in overall temperature difference from the helium to the process gas. A cooperative GE-KFA effort was undertaken to develop, fabricate, test, and evaluate a duplex steam reformer tube. GE was responsible for the development and fabrication of the tube, and KFA was responsible for testing the tube in the EVA I facility at Juelich. Both GE and KFA are evaluating the thermochemical and metallurgical test data. Actual fabrication of the tube was performed by Foster-Wheeler in accordance with the GE design. This paper reviews the highlights of the fabrication development and preliminary evaluation of the test data