WorldWideScience

Sample records for chamber simulating extracorporeal

  1. Development of an Accident Reproduction Simulator System Using a Hemodialysis Extracorporeal Circulation System

    OpenAIRE

    Nishite, Yoshiaki; Takesawa, Shingo

    2016-01-01

    Background Accidents that occur during dialysis treatment are notified to the medical staff via alarms raised by the dialysis apparatus. Similar to such real accidents, apparatus activation or accidents can be reproduced by simulating a treatment situation. An alarm that corresponds to such accidents can be utilized in the simulation model. Objectives The aim of this study was to create an extracorporeal circulation system (herein...

  2. Simulation training for extracorporeal membrane oxygenation

    Directory of Open Access Journals (Sweden)

    Roberta Brum

    2015-01-01

    Full Text Available Background: Extracorporeal membrane oxygenation (ECMO is a complex treatment. Despite this, there are a lack of training programs designed to develop relevant clinical and nonclinical skills required for ECMO specialists. The aim of the current study was to describe the design, implementation and evaluation of a 1-day simulation course for delivering training in ECMO. Methods: A 1-day simulation course was developed with educational and intensive care experts. First, the delegates received a lecture on the principles of simulation training and the importance of human factors. This was, followed by a practical demonstration and discussion of the ECMO circuit, console components, circuit interactions effects and potential complications. There were then five ECMO simulation scenarios with debriefing that covered technical and nontechnical issues. The course culminated in a knowledge-based assessment. Course outcomes were assessed using purpose-designed questionnaires. Results: We held 3 courses with a total of 14 delegates (9 intensive care nurses, 3 adult intensive care consultants and 2 ECMO technicians. Following the course, 8 (57% gained familiarity in troubleshooting an ECMO circuit, 6 (43% increased their familiarity with the ECMO pump and circuit, 8 (57% perceived an improvement in their communication skills and 7 (50% perceived an improvement in their leadership skills. At the end of the course, 13 (93% delegates agreed that they felt more confident in dealing with ECMO. Conclusions: Simulation-training courses may increase knowledge and confidence in dealing with ECMO emergencies. Further studies are indicated to determine whether simulation training improves clinical outcomes and translates to reduced complication rates in patients receiving ECMO.

  3. A new plant chamber facility PLUS coupled to the atmospheric simulation chamber SAPHIR

    Science.gov (United States)

    Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

    2015-11-01

    A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been build and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees are mixed with synthetic air and are transferred to the SAPHIR chamber where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOC) can be studied in detail. In PLUS all important enviromental parameters (e.g. temperature, PAR, soil RH etc.) are well-controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leafes of the plants is constructed such that gases are exposed to FEP Teflon film and other Teflon surfaces only to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 LED panels which have an emission strength up to 800 μmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOC) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light and temperature dependent BVOC emissions are studied using six Quercus Ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus Ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental set up and the utility of the newly added plant chamber.

  4. A new plant chamber facility, PLUS, coupled to the atmosphere simulation chamber SAPHIR

    Science.gov (United States)

    Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

    2016-03-01

    A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been built and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow-through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees is mixed with synthetic air and transferred to the SAPHIR chamber, where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOCs) can be studied in detail. In PLUS all important environmental parameters (e.g., temperature, photosynthetically active radiation (PAR), soil relative humidity (RH)) are well controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leaves of the plants is constructed such that gases are exposed to only fluorinated ethylene propylene (FEP) Teflon film and other Teflon surfaces to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 light-emitting diode (LED) panels, which have an emission strength up to 800 µmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOCs) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light- and temperature- dependent BVOC emissions are studied using six Quercus ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental setup and the utility of the newly added plant chamber.

  5. Simulated Field Trials Using an Indoor Aerosol Test Chamber

    National Research Council Canada - National Science Library

    Semler, D. D; Roth, A. P; Semler, K. A; Nolan, P. M

    2004-01-01

    .... In this method, the aerosol chamber control software manipulates circulation fan speeds, chamber vacuum and agent spray times to produce a simulated dynamic cloud within the aerosol test chamber...

  6. Simulated Field Trials Using An Indoor Aerosol Test Chamber

    National Research Council Canada - National Science Library

    Semler, D. D; Roth, A. P; Semler, K. A; Nolan, P. M

    2004-01-01

    .... In this method, the aerosol chamber control software manipulates circulation fan speeds, chamber vacuum and agent spray times to produce a simulated dynamic cloud within the aerosol test chamber...

  7. Drift Chambers Simulations in BM@N Experiment

    Directory of Open Access Journals (Sweden)

    Fedorišin Ján

    2016-01-01

    Full Text Available Drift chambers constitute an important part of the tracking system of the BM@N experiment designed to study the production of baryonic matter at the Nuclotron energies. GEANT programming package is employed to investigate the drift chamber response to particles produced in relativistic nuclear collisions of C+C nuclei, which are simulated by the UrQMD and LAQGSM Monte Carlo generators. These simulations are combined with the first BM@N experimental data to estimate particle track coordinates and their errors.

  8. Space plasma simulation chamber

    International Nuclear Information System (INIS)

    1986-01-01

    Scientific results of experiments and tests of instruments performed with the Space Plasma Simulation Chamber and its facility are reviewed in the following six categories. 1. Tests of instruments on board rockets, satellites and balloons. 2. Plasma wave experiments. 3. Measurements of plasma particles. 4. Optical measurements. 5. Plasma production. 6. Space plasms simulations. This facility has been managed under Laboratory Space Plasma Comittee since 1969 and used by scientists in cooperative programs with universities and institutes all over country. A list of publications is attached. (author)

  9. Planetary Simulation Chambers bring Mars to laboratory studies

    Energy Technology Data Exchange (ETDEWEB)

    Mateo-Marti, E.

    2016-07-01

    Although space missions provide fundamental and unique knowledge for planetary exploration, they are always costly and extremely time-consuming. Due to the obvious technical and economical limitations of in-situ planetary exploration, laboratory simulations are among the most feasible research options for making advances in planetary exploration. Therefore, laboratory simulations of planetary environments are a necessary and complementary option to expensive space missions. Simulation chambers are economical, more versatile, and allow for a higher number of experiments than space missions. Laboratory-based facilities are able to mimic the conditions found in the atmospheres and on the surfaces of a majority of planetary objects. Number of relevant applications in Mars planetary exploration will be described in order to provide an understanding about the potential and flexibility of planetary simulation chambers systems: mainly, stability and presence of certain minerals on Mars surface; and microorganisms potential habitability under planetary environmental conditions would be studied. Therefore, simulation chambers will be a promising tools and necessary platform to design future planetary space mission and to validate in-situ measurements from orbital or rover observations. (Author)

  10. MAN-IN-SIMULANT TEST (MIST) CHAMBER

    Data.gov (United States)

    Federal Laboratory Consortium — The MIST chamber uses methyl salicylate (oil of wintergreen) vapor as a simulant for HD agent to conduct system level evaluations of chemical protective ensembles....

  11. Improved climatic chamber for desiccation simulation

    Directory of Open Access Journals (Sweden)

    Lozada Catalina

    2016-01-01

    Full Text Available The climatic chamber at the Universidad de Los Andes was improved for modeling desiccation in soil layers. This chamber allows the measurement of different environmental variables. In this research, evaporation tests were conducted in water imposing boundary conditions for drying, and then these tests were performed in a soil layer. The soil was prepared from a slurry state and was drying controlling the temperature, the infrared radiation, the wind velocity, and the relative humidity. In the first part of this paper, a description of the climatic chamber, operation ranges and theoretical work principles of the climatic chamber are presented. Then, the second part shows the results for desiccation in water and soil. The desiccation tests performed with the climatic chamber allow simulating all environmental conditions accurately during drying coupling the effect of all environmental variables. As a result, the evaporation rate increases with infrared radiation in soil and water. The rate at the beginning of the desiccation tests in clays is the same as in water. However, this evaporation rate decreases as the soil becomes desiccated.

  12. A Facility for Long-Term Mars Simulation Experiments: The Mars Environmental Simulation Chamber (MESCH)

    Science.gov (United States)

    Jensen, Lars Liengaard; Merrison, Jonathan; Hansen, Aviaja Anna; Mikkelsen, Karina Aarup; Kristoffersen, Tommy; Nørnberg, Per; Lomstein, Bente Aagaard; Finster, Kai

    2008-06-01

    We describe the design, construction, and pilot operation of a Mars simulation facility comprised of a cryogenic environmental chamber, an atmospheric gas analyzer, and a xenon/mercury discharge source for UV generation. The Mars Environmental Simulation Chamber (MESCH) consists of a double-walled cylindrical chamber. The double wall provides a cooling mantle through which liquid N2 can be circulated. A load-lock system that consists of a small pressure-exchange chamber, which can be evacuated, allows for the exchange of samples without changing the chamber environment. Fitted within the MESCH is a carousel, which holds up to 10 steel sample tubes. Rotation of the carousel is controlled by an external motor. Each sample in the carousel can be placed at any desired position. Environmental data, such as temperature, pressure, and UV exposure time, are computer logged and used in automated feedback mechanisms, enabling a wide variety of experiments that include time series. Tests of the simulation facility have successfully demonstrated its ability to produce temperature cycles and maintain low temperature (down to -140°C), low atmospheric pressure (5 10 mbar), and a gas composition like that of Mars during long-term experiments.

  13. Tracking simulation and wire chamber requirements for the SSC

    International Nuclear Information System (INIS)

    Hanson, G.G.; Niczyporuk, B.B.; Palounek, A.P.T.

    1988-11-01

    Limitations placed on wire chambers by radiation damage and rate requirements in the SSC environment are reviewed. Possible conceptual designs for wire chamber tracking systems which meet these requirements are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 16 refs., 16 figs., 2 tabs

  14. The resistive plate chambers for CMS and their simulation

    Energy Technology Data Exchange (ETDEWEB)

    Abbrescia, M. E-mail: marcello.abbrescia@ba.infn.it; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Altieri, S.; Belli, G.; Bruno, G.; Guida, R.; Merlo, M.; Ratti, S.P.; Riccardi, C.; Torre, P.; Vitulo, P

    2001-09-21

    In this paper some results obtained by the CMS Resistive Plate Chamber collaboration during its five years long period of research and development are reported. The importance of the simulation in the design of the Resistive Plate Chambers for CMS is stressed.

  15. Nuclear signal simulation applied to gas ionizing chambers

    Energy Technology Data Exchange (ETDEWEB)

    Coulon, Romain; Dumazert, Jonathan [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, F-91191 Gif-sur-Yvette, (France)

    2015-07-01

    Particle transport codes used in detector simulation allow the calculation of the energy deposited by charged particles produced following an interaction. The pulses temporal shaping is more and more used in nuclear measurement into pulse shape analysis techniques. A model is proposed in this paper to simulate the pulse temporal shaping and the associated noise level thanks to the output track file PTRAC provides by Monte-Carlo particle transport codes. The model has been dedicated to ion chambers and more especially for High Pressure Xenon chambers HPXe where the pulse shape analysis can resolve some issues regarding with this technology as the ballistic deficit phenomenon. The model is fully described and an example is presented as a validation of such full detector simulation. (authors)

  16. Development of an Accident Reproduction Simulator System Using a Hemodialysis Extracorporeal Circulation System

    Science.gov (United States)

    Nishite, Yoshiaki; Takesawa, Shingo

    2016-01-01

    Background: Accidents that occur during dialysis treatment are notified to the medical staff via alarms raised by the dialysis apparatus. Similar to such real accidents, apparatus activation or accidents can be reproduced by simulating a treatment situation. An alarm that corresponds to such accidents can be utilized in the simulation model. Objectives: The aim of this study was to create an extracorporeal circulation system (hereinafter, the circulation system) for dialysis machines so that it sets off five types of alarms for: 1) decreased arterial pressure, 2) increased arterial pressure, 3) decreased venous pressure, 4) increased venous pressure, and 5) blood leakage, according to the five types of accidents chosen based on their frequency of occurrence and the degree of severity. Materials and Methods: In order to verify the alarm from the dialysis apparatus connected to the circulation system and the accident corresponding to it, an evaluation of the alarm for its reproducibility of an accident was performed under normal treatment circumstances. The method involved testing whether the dialysis apparatus raised the desired alarm from the moment of control of the circulation system, and measuring the time it took until the desired alarm was activated. This was tested on five main models from four dialyzer manufacturers that are currently used in Japan. Results: The results of the tests demonstrated successful activation of the alarms by the dialysis apparatus, which were appropriate for each of the five types of accidents. The time between the control of the circulatory system to the alarm signal was as follows, 1) venous pressure lower limit alarm: 7 seconds; 2) venous pressure lower limit: 8 seconds; 3) venous pressure upper limit: 7 seconds; 4) venous pressure lower limit alarm: 2 seconds; and 5) blood leakage alarm: 19 seconds. All alarms were set off in under 20 seconds. Conclusions: Thus, we can conclude that a simulator system using an extracorporeal

  17. Extracorporeal Treatment for Lithium Poisoning

    DEFF Research Database (Denmark)

    Decker, Brian S; Goldfarb, David S; Dargan, Paul I

    2015-01-01

    The Extracorporeal Treatments in Poisoning Workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments in poisoning. Here, the EXTRIP workgroup presents its recommendations for lithium poisoning. After a systematic literature search, clinical and toxico......The Extracorporeal Treatments in Poisoning Workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments in poisoning. Here, the EXTRIP workgroup presents its recommendations for lithium poisoning. After a systematic literature search, clinical...... extraction of patient-level data. The workgroup concluded that lithium is dialyzable (Level of evidence=A) and made the following recommendations: Extracorporeal treatment is recommended in severe lithium poisoning (1D). Extracorporeal treatment is recommended if kidney function is impaired and the [Li...... treatment (1D), but continuous RRT is an acceptable alternative (1D). The workgroup supported the use of extracorporeal treatment in severe lithium poisoning. Clinical decisions on when to use extracorporeal treatment should take into account the [Li(+)], kidney function, pattern of lithium toxicity...

  18. Extracorporeal treatment for thallium poisoning

    DEFF Research Database (Denmark)

    Ghannoum, Marc; Nolin, Thomas D; Goldfarb, David S

    2012-01-01

    The EXtracorporeal TReatments In Poisoning (EXTRIP) workgroup was formed to provide recommendations on the use of extracorporeal treatment (ECTR) in poisoning. To test and validate its methods, the workgroup reviewed data for thallium (Tl).......The EXtracorporeal TReatments In Poisoning (EXTRIP) workgroup was formed to provide recommendations on the use of extracorporeal treatment (ECTR) in poisoning. To test and validate its methods, the workgroup reviewed data for thallium (Tl)....

  19. Backscattered radiation into a transmission ionization chamber: Measurement and Monte Carlo simulation

    International Nuclear Information System (INIS)

    Yoshizumi, Maira T.; Yoriyaz, Helio; Caldas, Linda V.E.

    2010-01-01

    Backscattered radiation (BSR) from field-defining collimators can affect the response of a monitor chamber in X-radiation fields. This contribution must be considered since this kind of chamber is used to monitor the equipment response. In this work, the dependence of a transmission ionization chamber response on the aperture diameter of the collimators was studied experimentally and using a Monte Carlo (MC) technique. According to the results, the BSR increases the chamber response of over 4.0% in the case of a totally closed collimator and 50 kV energy beam, using both techniques. The results from Monte Carlo simulation confirm the validity of the simulated geometry.

  20. Pulse shape simulation for drift chambers with long drift paths

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, H J

    1987-09-15

    A detailed Monte Carlo program for the simulation of drift chamber pulse shapes is described. It has been applied to the case of a jet chamber with drift paths up to 24 cm. Results on pulse shapes and corresponding spatial and double hit resolution are discussed and compared to recent measurements of the OPAL central detector jet chamber full size prototype and to measurements of a small 20-wire prototype, which was designed to study the pulse shapes generated by tracks in a magnetic field. Simulated pulse shapes and spatial resolutions agree well with the experimental data. Clustering, saturation and wire crosstalk are shown to be necessary ingredients in the simulation. A deterioration in resolution due to the influence of crosstalk signals is correctly reproduced, as well as the cancellation of this effect by a hardwired first and second neighbour crosstalk compensation. The simulation correctly describes the asymmetry in spatial resolution observed for tracks with positive or negative inclination against the wire plane when a magnetic field is present. The effect of saturation on double hit resolution is found to be small. The magnetic field is predicted to improve the double hit resolution.

  1. Pulse shape simulation for drift chambers with long drift paths

    International Nuclear Information System (INIS)

    Mayer, H.J.

    1987-01-01

    A detailed Monte Carlo program for the simulation of drift chamber pulse shapes is described. It has been applied to the case of a jet chamber with drift paths up to 24 cm. Results on pulse shapes and corresponding spatial and double hit resolution are discussed and compared to recent measurements of the OPAL central detector jet chamber full size prototype and to measurements of a small 20-wire prototype, which was designed to study the pulse shapes generated by tracks in a magnetic field. Simulated pulse shapes and spatial resolutions agree well with the experimental data. Clustering, saturation and wire crosstalk are shown to be necessary ingredients in the simulation. A deterioration in resolution due to the influence of crosstalk signals is correctly reproduced, as well as the cancellation of this effect by a hardwired first and second neighbour crosstalk compensation. The simulation correctly describes the asymmetry in spatial resolution observed for tracks with positive or negative inclination against the wire plane when a magnetic field is present. The effect of saturation on double hit resolution is found to be small. The magnetic field is predicted to improve the double hit resolution. (orig.)

  2. Simulation of Chamber Transport for Heavy-Ion-Fusion Drivers

    International Nuclear Information System (INIS)

    Sharp, W.M.; Callahan, D.A.; Tabak, M.; Yu, S.S.; Peterson, P.F.; Rose, D.V.; Welch, D.R.

    2003-01-01

    The heavy-ion fusion (HIF) community recently developed a power-plant design that meets the various requirements of accelerators, final focus, chamber transport, and targets. The point design is intended to minimize physics risk and is certainly not optimal for the cost of electricity. Recent chamber-transport simulations, however, indicate that changes in the beam ion species, the convergence angle, and the emittance might allow more-economical designs

  3. Chamber-transport simulation results for heavy-ion fusion drivers

    International Nuclear Information System (INIS)

    Sharp, W M; Callahan, D A; Tabak, M; Yu, S S; Peterson, P F; Rose, D V; Welch, D R

    2004-01-01

    The heavy-ion fusion (HIF) community recently developed a power-plant design that meets the various requirements of accelerators, final focus, chamber transport, and targets. The point design is intended to minimize physics risk and is certainly not optimal for the cost of electricity. Recent chamber-transport simulations, however, indicate that changes in the beam ion species, the convergence angle, and the emittance might allow more-economical designs

  4. SIMULATION OF CHAMBER TRANSPORT FOR HEAVY-ION FUSION DRIVERS

    International Nuclear Information System (INIS)

    Sharp, W M; Callahan, D A; Tabak, M; Yu, S S; Peterson, P F; Rose, D V; Welch, D R

    2004-01-01

    The heavy-ion fusion (HIF) community recently developed a power-plant design that meets the various requirements of accelerators, final focus, chamber transport, and targets. The point design is intended to minimize physics risk and is certainly not optimal for the cost of electricity. Recent chamber-transport simulations, however, indicate that changes in the beam ion species, the convergence angle, and the emittance might allow more-economical designs

  5. Automatic Control of Veno-Venous Extracorporeal Lung Assist.

    Science.gov (United States)

    Kopp, Ruedger; Bensberg, Ralf; Stollenwerk, Andre; Arens, Jutta; Grottke, Oliver; Walter, Marian; Rossaint, Rolf

    2016-10-01

    Veno-venous extracorporeal lung assist (ECLA) can provide sufficient gas exchange even in most severe cases of acute respiratory distress syndrome. Commercially available systems are manually controlled, although an automatically controlled ECLA could allow individualized and continuous adaption to clinical requirements. Therefore, we developed a demonstrator with an integrated control algorithm to keep continuously measured peripheral oxygen saturation and partial pressure of carbon dioxide constant by automatically adjusting extracorporeal blood and gas flow. The "SmartECLA" system was tested in six animal experiments with increasing pulmonary hypoventilation and hypoxic inspiratory gas mixture to simulate progressive acute respiratory failure. During a cumulative evaluation time of 32 h for all experiments, automatic ECLA control resulted in a peripheral oxygen saturation ≥90% for 98% of the time with the lowest value of 82% for 15 s. Partial pressure of venous carbon dioxide was between 40 and 49 mm Hg for 97% of the time with no value 49 mm Hg. With decreasing inspiratory oxygen concentration, extracorporeal oxygen uptake increased from 68 ± 25 to 154 ± 34 mL/min (P < 0.05), and reducing respiratory rate resulted in increasing extracorporeal carbon dioxide elimination from 71 ± 37 to 92 ± 37 mL/min (P < 0.05). The "SmartECLA" demonstrator allowed reliable automatic control of the extracorporeal circuit. Proof of concept could be demonstrated for this novel automatically controlled veno-venous ECLA circuit. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  6. Severe hypoxemia during veno-venous extracorporeal membrane oxygenation: exploring the limits of extracorporeal respiratory support

    Directory of Open Access Journals (Sweden)

    Liane Brescovici Nunes

    2014-03-01

    Full Text Available OBJECTIVE: Veno-venous extracorporeal oxygenation for respiratory support has emerged as a rescue alternative for patients with hypoxemia. However, in some patients with more severe lung injury, extracorporeal support fails to restore arterial oxygenation. Based on four clinical vignettes, the aims of this article were to describe the pathophysiology of this concerning problem and to discuss possibilities for hypoxemia resolution. METHODS: Considering the main reasons and rationale for hypoxemia during veno-venous extracorporeal membrane oxygenation, some possible bedside solutions must be considered: 1 optimization of extracorporeal membrane oxygenation blood flow; 2 identification of recirculation and cannula repositioning if necessary; 3 optimization of residual lung function and consideration of blood transfusion; 4 diagnosis of oxygenator dysfunction and consideration of its replacement; and finally 5 optimization of the ratio of extracorporeal membrane oxygenation blood flow to cardiac output, based on the reduction of cardiac output. CONCLUSION: Therefore, based on the pathophysiology of hypoxemia during veno-venous extracorporeal oxygenation support, we propose a stepwise approach to help guide specific interventions.

  7. Characterisation of the photolytic HONO-source in the atmosphere simulation chamber SAPHIR

    Directory of Open Access Journals (Sweden)

    F. Rohrer

    2005-01-01

    Full Text Available HONO formation has been proposed as an important OH radical source in simulation chambers for more than two decades. Besides the heterogeneous HONO formation by the dark reaction of NO2 and adsorbed water, a photolytic source has been proposed to explain the elevated reactivity in simulation chamber experiments. However, the mechanism of the photolytic process is not well understood so far. As expected, production of HONO and NOx was also observed inside the new atmospheric simulation chamber SAPHIR under solar irradiation. This photolytic HONO and NOx formation was studied with a sensitive HONO instrument under reproducible controlled conditions at atmospheric concentrations of other trace gases. It is shown that the photolytic HONO source in the SAPHIR chamber is not caused by NO2 reactions and that it is the only direct NOy source under illuminated conditions. In addition, the photolysis of nitrate which was recently postulated for the observed photolytic HONO formation on snow, ground, and glass surfaces, can be excluded in the chamber. A photolytic HONO source at the surface of the chamber is proposed which is strongly dependent on humidity, on light intensity, and on temperature. An empirical function describes these dependencies and reproduces the observed HONO formation rates to within 10%. It is shown that the photolysis of HONO represents the dominant radical source in the SAPHIR chamber for typical tropospheric O3/H2O concentrations. For these conditions, the HONO concentrations inside SAPHIR are similar to recent observations in ambient air.

  8. Simulation studies on a prototype ionization chamber for measurement of personal dose equivalent, Hp(10)

    International Nuclear Information System (INIS)

    Cardoso, J.; Oliveira, C.; Carvalho, A.F.

    2005-01-01

    Full text: The Metrological Laboratory of lonizing Radiation and Radioactivity (LMRIR) of Nuclear and Technological Institute (ITN) has designed and constructed a prototype ionization chamber for direct measurement of the personal dose equivalent, H p (10), similar to the developed by the Physikalisch-Technische Bundesanstalt (PTB) and now commercialized by PTW. Tests already performed had shown that the behaviour of this chamber is very close to the PTB chamber, namely the energy dependence for the x-ray radiation qualities of the ISO 4037-1 narrow series N-30, N-40, N-60, N-80, N-100 and N-120 and also for gamma radiation of 137 Cs and 60 Co. However, the results obtained also show a high dependence on the energy for some incident radiation angles and a low magnitude of the electrical response of the ionization chamber. In order to try to optimize the performance of the chamber, namely to decrease the energy dependence and to improve the magnitude of the electrical response of the ionization chamber, the LMRIR initiated numerical simulation of this ionization chamber using a Monte-Carlo method for simulation of radiation transport using, in a first step, the MCNPX code. So, simulation studies of some physical parameters are been performed in order to optimize the response of the ionization chamber, namely the diameter of the central electrode of the ionization chamber, the thickness of the front wall of the ionization chamber, among others. Preliminary results show that probably the actual geometry of the ionization chamber is not yet the optimized configuration. The simulation study will carry on in order to find the optimum geometry. (author)

  9. 3D dynamic simulation of crack propagation in extracorporeal shock wave lithotripsy

    Science.gov (United States)

    Wijerathne, M. L. L.; Hori, Muneo; Sakaguchi, Hide; Oguni, Kenji

    2010-06-01

    Some experimental observations of Shock Wave Lithotripsy(SWL), which include 3D dynamic crack propagation, are simulated with the aim of reproducing fragmentation of kidney stones with SWL. Extracorporeal shock wave lithotripsy (ESWL) is the fragmentation of kidney stones by focusing an ultrasonic pressure pulse onto the stones. 3D models with fine discretization are used to accurately capture the high amplitude shear shock waves. For solving the resulting large scale dynamic crack propagation problem, PDS-FEM is used; it provides numerically efficient failure treatments. With a distributed memory parallel code of PDS-FEM, experimentally observed 3D photoelastic images of transient stress waves and crack patterns in cylindrical samples are successfully reproduced. The numerical crack patterns are in good agreement with the experimental ones, quantitatively. The results shows that the high amplitude shear waves induced in solid, by the lithotriptor generated shock wave, play a dominant role in stone fragmentation.

  10. Simulated annealing algorithm for solving chambering student-case assignment problem

    Science.gov (United States)

    Ghazali, Saadiah; Abdul-Rahman, Syariza

    2015-12-01

    The problem related to project assignment problem is one of popular practical problem that appear nowadays. The challenge of solving the problem raise whenever the complexity related to preferences, the existence of real-world constraints and problem size increased. This study focuses on solving a chambering student-case assignment problem by using a simulated annealing algorithm where this problem is classified under project assignment problem. The project assignment problem is considered as hard combinatorial optimization problem and solving it using a metaheuristic approach is an advantage because it could return a good solution in a reasonable time. The problem of assigning chambering students to cases has never been addressed in the literature before. For the proposed problem, it is essential for law graduates to peruse in chambers before they are qualified to become legal counselor. Thus, assigning the chambering students to cases is a critically needed especially when involving many preferences. Hence, this study presents a preliminary study of the proposed project assignment problem. The objective of the study is to minimize the total completion time for all students in solving the given cases. This study employed a minimum cost greedy heuristic in order to construct a feasible initial solution. The search then is preceded with a simulated annealing algorithm for further improvement of solution quality. The analysis of the obtained result has shown that the proposed simulated annealing algorithm has greatly improved the solution constructed by the minimum cost greedy heuristic. Hence, this research has demonstrated the advantages of solving project assignment problem by using metaheuristic techniques.

  11. Contamination Control Assessment of the World's Largest Space Environment Simulation Chamber

    Science.gov (United States)

    Snyder, Aaron; Henry, Michael W.; Grisnik, Stanley P.; Sinclair, Stephen M.

    2012-01-01

    The Space Power Facility s thermal vacuum test chamber is the largest chamber in the world capable of providing an environment for space simulation. To improve performance and meet stringent requirements of a wide customer base, significant modifications were made to the vacuum chamber. These include major changes to the vacuum system and numerous enhancements to the chamber s unique polar crane, with a goal of providing high cleanliness levels. The significance of these changes and modifications are discussed in this paper. In addition, the composition and arrangement of the pumping system and its impact on molecular back-streaming are discussed in detail. Molecular contamination measurements obtained with a TQCM and witness wafers during two recent integrated system tests of the chamber are presented and discussed. Finally, a concluding remarks section is presented.

  12. WE-G-BRA-06: Calibrating an Ionisation Chamber: Gaining Experience Using a Dosimetry 'flight Simulator'.

    Science.gov (United States)

    Beavis, A; Saunderson, J; Ward, J

    2012-06-01

    Recently there has been great interest in the use of simulation training, with the view to enhance safety within radiotherapy practice. We have developed a Virtual Environment for Radiotherapy Training (VERT) which facilitates this, including the simulation of a number of 'Physics practices'. One such process is the calibration of an ionisation chamber for use in Linac photon beams. The VERT system was used to provide a life sized 3D virtual environment within which we were able to simulate the calibration of a departmental chamber for 6MV and 15 MV beams following the UK 1990 Code of Practice. The characteristics of the beams are fixed parameters in the simulation, whereas default (Absorbed dose to water) correction factors of the chambers are configurable thereby dictating their response in the virtual x-ray beam. When the simulation is started, a random, realistic temperature and pressure is assigned to the bunker. Measurement and chamber positional errors are assigned to the chambers. A virtual water phantom was placed on the Linac couch and irradiated through the side using a 10 × 10 field. With a chamber at the appropriate depths and irradiated iso-centrically, the Quality Indices (QI) of the beams were obtained. The two chambers were 'inter-compared', allowing the departmental chamber calibration factor to be calculated from that of the reference chamber. For the virtual 6/15 MV beams, the QI were found to be 0.668/ 0.761 and the inter-comparison ratios 0.4408/ 0.4402 respectively. The departmental chamber calibration factors were calculated; applying these and appropriate environmental corrections allowed the output of the Linac to be confirmed. We have shown how a virtual training environment can be used to demonstrate practical processes and reinforce learning. The UK CoP was used here, however any relevant protocol could be demonstrated. Two of the authors (Beavis and Ward) are Founders of Vertual Ltd, a spin-out company created to commercialise the

  13. Mimicking Mars: a vacuum simulation chamber for testing environmental instrumentation for Mars exploration.

    Science.gov (United States)

    Sobrado, J M; Martín-Soler, J; Martín-Gago, J A

    2014-03-01

    We have built a Mars environmental simulation chamber, designed to test new electromechanical devices and instruments that could be used in space missions. We have developed this environmental system aiming at validating the meteorological station Rover Environment Monitoring Station of NASA's Mars Science Laboratory mission currently installed on Curiosity rover. The vacuum chamber has been built following a modular configuration and operates at pressures ranging from 1000 to 10(-6) mbars, and it is possible to control the gas composition (the atmosphere) within this pressure range. The device (or sample) under study can be irradiated by an ultraviolet source and its temperature can be controlled in the range from 108 to 423 K. As an important improvement with respect to other simulation chambers, the atmospheric gas into the experimental chamber is cooled at the walls by the use of liquid-nitrogen heat exchangers. This chamber incorporates a dust generation mechanism designed to study Martian-dust deposition while modifying the conditions of temperature, and UV irradiated.

  14. Study of the replacement correction factors for ionization chamber dosimetry by Monte Carlo simulations

    Science.gov (United States)

    Wang, Lilie

    In ionization chamber radiation dosimetry, the introduction of the ion chamber into medium will unavoidably distort the radiation field near the chamber because the chamber cavity material (air) is different from the medium. A replacement correction factor, Prepl was introduced in order to correct the chamber readings to give an accurate radiation dose in the medium without the presence of the chamber. Generally it is very hard to measure the values of Prepl since they are intertwined with the chamber wall effect. In addition, the P repl values always come together with the stopping-power ratio of the two media involved. This makes the problem of determining the P repl values even more complicated. Monte Carlo simulation is an ideal method to investigate the replacement correction factors. In this study, four different methods of calculating the values of Prepl by Monte Carlo simulation are discussed. Two of the methods are designated as 'direct' methods in the sense that the evaluation of the stopping-power ratio is not necessary. The systematic uncertainties of the two direct methods are estimated to be about 0.1-0.2% which comes from the ambiguous definition of the energy cutoff Delta used in the Spencer-Attix cavity theory. The two direct methods are used to calculate the values of P repl for both plane-parallel chambers and cylindrical thimble chambers in either electron beams or photon beams. The calculation results are compared to measurements. For electron beams, good agreements are obtained. For thimble chambers in photon beams, significant discrepancies are observed between calculations and measurements. The experiments are thus investigated and the procedures are simulated by the Monte Carlo method. It is found that the interpretation of the measured data as the replacement correction factors in dosimetry protocols are not correct. In applying the calculation to the BIPM graphite chamber in a 60Co beam, the calculated values of P repl differ from those

  15. Simulation of the CMS Resistive Plate Chambers

    CERN Document Server

    Hadjiiska, R; Pavlov, B; Petkov, P; Dimitrov, A; Beernaert, K; Cimmino, A; Costantini, S; Garcia, G; Lellouch, J; Marinov, A; Ocampo, A; Strobbe, N; Thyssen, F; Tytgat, M; Verwilligen, P; Yazgan, E; Zaganidis, N; Aleksandrov, A; Genchev, V; Iaydjiev, P; Rodozov, M; Shopova, M; Sultanov, G; Ban, Y; Cai, J; Xue, Z; Ge, Y; Li, Q; Qian, S; Avila, C; Chaparro, L F; Gomez, J P; Moreno, B Gomez; Oliveros, A F Osorio; Sanabria, J C; Assran, Y; Sharma, A; Abbrescia, M; Colaleo, A; Pugliese, G; Loddo, F; Calabria, C; Maggi, M; Benussi, L; Bianco, S; Colafranceschi, S; Piccolo, D; Carrillo, C; Iorio, O; Buontempo, S; Paolucci, P; Vitulo, P; Berzano, U; Gabusi, M; Kang, M; Lee, K S; Park, S K; Shin, S; Kim, M S; Seo, H; Goh, J; Choi, Y; Shoaib, M

    2013-01-01

    The Resistive Plate Chamber (RPC) muon subsystem contributes significantly to the formation of the trigger decision and reconstruction of the muon trajectory parameters. Simulation of the RPC response is a crucial part of the entire CMS Monte Carlo software and directly influences the final physical results. An algorithm based on the parametrization of RPC efficiency, noise, cluster size and timing for every strip has been developed. Experimental data obtained from cosmic and proton-proton collisions at $\\sqrt{s}=7$ TeV have been used for determination of the parameters. A dedicated validation procedure has been developed. A good agreement between the simulated and experimental data has been achieved.

  16. Wire chamber requirements and tracking simulation studies for tracking systems at the superconducting super collider

    International Nuclear Information System (INIS)

    Hanson, G.G.; Niczyporuk, B.B.; Palounek, A.P.T.

    1989-02-01

    Limitations placed on wire chambers by radiation damage and rate requirements in the SSC environment are reviewed. Possible conceptual designs for wire chamber tracking systems which meet these requirements are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. Such computer simulation studies are necessary to determine the feasibility of wire chamber tracking systems for complex events in a high-rate environment such as the SSC. 11 refs., 9 figs., 1 tab

  17. High resolution real time capable combustion chamber simulation; Zeitlich hochaufloesende echtzeitfaehige Brennraumsimulation

    Energy Technology Data Exchange (ETDEWEB)

    Piewek, J. [Volkswagen AG, Wolfsburg (Germany)

    2008-07-01

    The article describes a zero-dimensional model for the real time capable combustion chamber pressure calculation with analogue pressure sensor output. The closed-loop-operation of an Engine Control Unit is shown at the hardware-in-the-loop-simulator (HiL simulator) for a 4-cylinder common rail diesel engine. The presentation of the model focuses on the simulation of the load variation which does not depend on the injection system and thus the simulated heat release rate. Particular attention is paid to the simulation and the resulting test possibilities regarding to full-variable valve gears. It is shown that black box models consisting in the HiL mean value model for the aspirated gas mass, the exhaust gas temperature after the outlet valve and the mean indicated pressure can be replaced by calculations from the high-resolution combustion chamber model. (orig.)

  18. Mimicking Mars: A vacuum simulation chamber for testing environmental instrumentation for Mars exploration

    Energy Technology Data Exchange (ETDEWEB)

    Sobrado, J. M., E-mail: sobradovj@inta.es; Martín-Soler, J. [Centro de Astrobiología (CAB), INTA-CSIC, Torrejón de Ardoz, 28850 Madrid (Spain); Martín-Gago, J. A. [Centro de Astrobiología (CAB), INTA-CSIC, Torrejón de Ardoz, 28850 Madrid (Spain); Instituto de Ciencias de Materiales de Madrid (ICMM-CSIC), Cantoblanco, 28049 Madrid (Spain)

    2014-03-15

    We have built a Mars environmental simulation chamber, designed to test new electromechanical devices and instruments that could be used in space missions. We have developed this environmental system aiming at validating the meteorological station Rover Environment Monitoring Station of NASA's Mars Science Laboratory mission currently installed on Curiosity rover. The vacuum chamber has been built following a modular configuration and operates at pressures ranging from 1000 to 10{sup −6} mbars, and it is possible to control the gas composition (the atmosphere) within this pressure range. The device (or sample) under study can be irradiated by an ultraviolet source and its temperature can be controlled in the range from 108 to 423 K. As an important improvement with respect to other simulation chambers, the atmospheric gas into the experimental chamber is cooled at the walls by the use of liquid-nitrogen heat exchangers. This chamber incorporates a dust generation mechanism designed to study Martian-dust deposition while modifying the conditions of temperature, and UV irradiated.

  19. Measurement and simulation of the drift pulses and resolution in the micro-jet chamber

    International Nuclear Information System (INIS)

    Va'vra, J.

    1983-01-01

    We have tested a prototype of a micro-jet chamber, using both a nitrogen laser and a 10GeV electron beam. The achieved resolution in the particle beam was sigma = 18μm for a lmm impact parameter and 22μm when averaging over the entire beam profile. The experimental results were compared to a Monte Carlo program which simulates the pulse shapes and resolution in drift chambers of any geometry. The main emphasis in our simulation analysis was to study various strategies for drift chambers in order to achieve the best possible timing resolution

  20. Simulation of chamber experiments

    International Nuclear Information System (INIS)

    Ivanov, V.G.

    1981-01-01

    The description of the system of computer simulation of experiments conducted by means of track detectors with film data output is given. Considered is the principle of organization of computer model of the chamber experiment comprising the following stages: generation of events, generation of measurements, ge-- neration of scanning results, generation of distorbions, generated data calibration, filtration, events reconstruction, kinematic identification, total results tape formation, analysis of the results. Generation programs are formed as special RAM-files, where the RAM-file is the text of the program written in FORTRAN and divided into structural elements. All the programs are a ''part of the ''Hydra'' system. The system possibilities are considered on the base of the CDSC-6500 computer. The five-beam event generation, creation data structure for identification and calculation by the kinematic program take about 1s of CDC-6500 computer time [ru

  1. Surgical myocardial revascularization without extracorporeal circulation

    Directory of Open Access Journals (Sweden)

    Salomón Soriano Ordinola Rojas

    2003-05-01

    Full Text Available OBJECTIVE: To assess the immediate postoperative period of patients undergoing myocardial revascularization without extracorporeal circulation with different types of grafts. METHODS: One hundred and twelve patients, 89 (79.5% of whom were males, were revascularized without extracorporeal circulation. Their ages ranged from 39 to 85 years. The criteria for indicating myocardial revascularization without extracorporeal circulation were as follows: revascularized coronary artery caliber > 1.5 mm, lack of intramyocardial trajectory on coronary angiography, noncalcified coronary arteries, and tolerance of the heart to the different rotation maneuvers. RESULTS: Myocardial revascularization without extracorporeal circulation was performed in 112 patients. Three were converted to extracorporeal circulation, which required a longer hospital stay but did not impact mortality. During the procedure, the following events were observed: atrial fibrillation in 10 patients, ventricular fibrillation in 4, total transient atrioventricular block in 2, ventricular extrasystoles in 58, use of a device to retrieve red blood cells in 53, blood transfusion in 8, and arterial hypotension in 89 patients. Coronary angiography was performed in 20 patients on the seventh postoperative day when the grafts were patent. CONCLUSION: Myocardial revascularization without extracorporeal circulation is a reproducible technique that is an alternative for treating ischemic heart disease.

  2. The atmosphere simulation chamber SAPHIR: a tool for the investigation of photochemistry.

    Science.gov (United States)

    Brauers, T.; Bohn, B.; Johnen, F.-J.; Rohrer, R.; Rodriguez Bares, S.; Tillmann, R.; Wahner, A.

    2003-04-01

    On the campus of the Forschungszentrum Jülich we constructed SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) which was accomplished in fall 2001. The chamber consists of a 280-m^3 double-wall Teflon bag of cylindrical shape that is held by a steel frame. Typically 75% of the outside actinic flux (290~nm~--~420~nm) is available inside the chamber. A louvre system allows switching between full sun light and dark within 40 s giving the opportunity to study relaxation processes of the photo chemical system. The SAPHIR chamber is equipped with a comprehensive set of sensitive instruments including the measurements of OH, HO_2, CO, hydrocarbons, aldehydes, nitrogen-oxides and solar radiation. Moreover, the modular concept of SAPHIR allows fast and flexible integration of new instruments and techniques. In this paper we will show the unique and new features of the SAPHIR chamber, namely the clean air supply and high purity water vapor supply providing a wide range of trace gas concentrations being accessible through the experiments. We will also present examples from the first year of SAPHIR experiment showing the scope of application from high quality instrument inter-comparison and kinetic studies to the simulation of complex mixtures of trace gases at ambient concentrations.

  3. Simulation of the heat transfer around the ATLAS muon chambers

    CERN Multimedia

    2005-01-01

    This 2D simulation recently carried out on the ATLAS muon chambers by a small team of CERN engineers specialises in the numerical computation of fluid dynamics, in other words the flow of fluids and heat.

  4. Extracorporeal treatment for acetaminophen poisoning

    DEFF Research Database (Denmark)

    Gosselin, S; Juurlink, D N; Kielstein, J T

    2014-01-01

    BACKGROUND: The Extracorporeal Treatments in Poisoning (EXTRIP) workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments (ECTR) in poisoning and the results are presented here for acetaminophen (APAP). METHODS: After a systematic review of the litera...... of NAC has not been definitively demonstrated....

  5. Extracorporeal Treatment for Metformin Poisoning

    DEFF Research Database (Denmark)

    Calello, Diane P; Liu, Kathleen D; Wiegand, Timothy J

    2015-01-01

    diverse professions, presents its systematic review and clinical recommendations for extracorporeal treatment in metformin poisoning. METHODS: A systematic literature search was performed, data extracted, findings summarized, and structured voting statements developed. A two-round modified Delphi method...... was used to achieve consensus on voting statements and RAND/UCLA Appropriateness Method to quantify disagreement. Anonymized votes and opinions were compiled and discussed. A second vote determined the final recommendations. RESULTS: One hundred seventy-five articles were identified, including 63 deaths...... appears to be amenable to extracorporeal treatments. Despite clinical evidence comprised mostly of case reports and suboptimal toxicokinetic data, the workgroup recommended extracorporeal removal in the case of severe metformin poisoning....

  6. Acoustic wave focusing in an ellipsoidal reflector for extracorporeal shock-wave lithotripsy

    Science.gov (United States)

    Lottati, Itzhak; Eidelman, Shmuel

    1993-07-01

    Simulations of acoustic wave focusing in an ellipsoidal reflector for extracorporeal shock-wave lithotripsy (ESWL) are presented. The simulations are done on a structured/unstructured grid with a modified Tait equation of state for water. The Euler equations are solved by applying a second-order Godunov method. The computed results compare very well with the experimental results.

  7. Numerical Simulation of a Dual-Chamber Oscillating Water Column Wave Energy Converter

    Directory of Open Access Journals (Sweden)

    Dezhi Ning

    2017-09-01

    Full Text Available The performance of a dual-chamber Oscillating Water Column (OWC Wave Energy Converter (WEC is considered in the present study. The device has two sub-chambers with a shared orifice. A two-dimensional (2D fully nonlinear numerical wave flume based on the potential-flow theory and the time-domain higher-order boundary element method (HOBEM is applied for the simulation. The incident waves are generated by using the immerged sources and the air-fluid coupling influence is considered with a simplified pneumatic model. In the present study, the variation of the surface elevation and the water column volume in the two sub-chambers are investigated. The effects of the chamber geometry (i.e., the draft and breadth of two chambers on the surface elevation and the air pressure in the chamber are investigated, respectively. It is demonstrated that the surface elevations in the two sub-chambers are strongly dependent on the wave conditions. The larger the wavelength, the more synchronous motion of the two water columns in the two sub-chambers, thus, the lager the variation of the water column volume.

  8. The Mobile Chamber

    Science.gov (United States)

    Scharfstein, Gregory; Cox, Russell

    2012-01-01

    A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

  9. Extracorporeal Pregnancy as a Feminist Issue

    Directory of Open Access Journals (Sweden)

    Iskra Krstić

    2015-10-01

    Full Text Available Extracorporeal pregnancy (ectogenesis presents perhaps the culmination of reproductive technology (NRT. Second wave feminism welcomed the use of NRT (including extracorporeal pregnancy as a means of women’s liberation. Later on, theories belonging to the third wave pointed out the negative implications of NRT and reclaimed the power of unassisted reproduction. This paper will try to point out some remaining productive potentials of NRT and extracorporeal pregnancy. The author wishes to explore the changes in the conceptualisation of the integrity of the individual in the context of the feminist critique of ectogenesis.

  10. Progresses in the simulation of Resistive Plate Chambers in avalanche mode

    Energy Technology Data Exchange (ETDEWEB)

    Abbrescia, M.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Altieri, S.; Bruno, G.; Gianini, G.; Ratti, S.P.; Viola, L.; Vitulo, P

    1999-08-01

    New results about the simulation of Resistive Plate Chambers are reported; particular emphasis is put in the understanding of charge spectra in regions where deviations from the pure avalanche mode of operation can be present.

  11. Hypobaric chamber for the study of oral health problems in a simulated spacecraft environment

    Science.gov (United States)

    Brown, L. R.

    1974-01-01

    A hypobaric chamber was constructed to house two marmo-sets simultaneously in a space-simulated environment for periods of 14, 28 and 56 days which coincided with the anticipated Skylab missions. This report details the fabrication, operation, and performance of the chamber and very briefly reviews the scientific data from nine chamber trials involving 18 animals. The possible application of this model system to studies unrelated to oral health or space missions is discussed.

  12. A Preliminary Study on Time Projection Chamber Simulation for Fission Cross Section Measurements with Geant4

    International Nuclear Information System (INIS)

    Kim, Jong Woon; Lee, Youngouk; Kim, Jae Cheon

    2014-01-01

    We present the details of the TPC simulation with Geant4 and show the results. TPC can provide more information than a fission chamber in that it is possible to distinguish different particle types. Simulations are conducted for uranium and plutonium targets with 20MeV neutrons. The simulation results are compared with the reference and show reasonable results. This is the first phase of study for realizing a TPC in the NFS at RAON, and we have more work to do, such as applying an electric field, signal processing in the simulation, and manufacturing of a TPC. The standard in fission cross section measurement is a fission chamber. It is basically just two parallel plates separated by a few centimeters of gas. A power supply connected to the plates sets up a moderate electric field. The target is deposited onto one of the plates. When fission occurs, the fragments ionize the gas, and the electric field causes the produced electrons to drift to the opposite plate, which records the total energy deposited in the chamber. A Time Projection Chamber (TPC) is a gas ionization detector similar to a fission chamber. However, it can measure the charged particle trajectories in the active volume in three dimensions by adding several readouts on the pad plane (fission chamber has only one readout one a pad plane). The specific ionization for each particle track enables the TPC to distinguish different particle types. A TPC will be used for fission cross section measurements in the Neutron Science Facility (NSF) at RAON. As a preliminary study, we present details of TPC simulation with Geant4 and discuss the results

  13. Application of PSpice circuit simulator in development of resistive plate chamber detector

    International Nuclear Information System (INIS)

    Wang Yaping; Cai Xu

    2008-01-01

    An electrical model was presented for resistive plate chamber (RPC) detector. The readout signals of RPC detector were studied with PSpice simulation based on the model. The simulation results show a good agreement with real data and authoritative data. Physical performance of RPC detector can be predicted by the PSpice simulation, so this is an efficient means to optimize RPC detector's research and development. (authors)

  14. Simulations of intense heavy ion beams propagating through a gaseous fusion target chamber

    International Nuclear Information System (INIS)

    Welch, D.R.; Rose, D.V.; Oliver, B.V.; Genoni, T.C.; Clark, R.E.; Olson, C.L.; Yu, S.S.

    2002-01-01

    In heavy-ion inertial confinement fusion (HIF), an ion beam is transported several meters through the reactor chamber to the target. This standoff distance mitigates damage to the accelerator from the target explosion. For the high perveance beams and millimeter-scale targets under consideration, the transport method is largely determined by the degree of ion charge and current neutralization in the chamber. This neutralization becomes increasingly difficult as the beam interacts with the ambient chamber environment and strips to higher charge states. Nearly complete neutralization permits neutralized-ballistic transport (main-line HIF transport method), where the ion beam enters the chamber at roughly 3-cm radius and focuses onto the target. In the backup pinched-transport schemes, the beam is first focused outside the chamber before propagating at small radius to the target. With nearly complete charge neutralization, the large beam divergence is contained by a strong magnetic field resulting from roughly 50-kA net current. In assisted-pinched transport, a preformed discharge channel provides the net current and the discharge plasma provides nearly complete charge and current neutralization of the beam. In self-pinched transport, the residual net current results solely from the beam-driven breakdown of the ambient gas. Using hybrid particle-in-cell simulation codes, the behavior of HIF driver-scale beams in these three transport modes is examined. Simulations of neutralized ballistic transport, at a few-mTorr flibe pressure, show excellent neutralization given a preformed or photoionized (from the heated target) plasma. Two- and three-dimensional simulations of assisted-pinch transport in roughly 1-Torr Xe show the importance of attaining >1-μs magnetic diffusion time to limit self-field effects and achieve good transport efficiency. For Xe gas pressures ranging from 10-150 mTorr, calculations predict a robust self-magnetic force sufficient for self

  15. Simulation of pulverized coal fired boiler: reaction chamber

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, C.P.; Lansarin, M.A.; Secchi, A.R.; Mendes, T.F. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Dept. de Engenharia Quimica. Grupo de Modelagem, Simulacao, Controle e Otimizacao de Processos)]. E-mail: {cperdomo, marla, arge, talita}@enq.ufrgs.br

    2005-06-15

    This work is part of a joint project to built a computational tool for power plant simulation, dealing specifically with the reaction chamber (place of the boiler where the fuel is burned). In order to describe the conversion of chemical energy to thermal energy, an one dimensional pseudo-homogeneous mathematical model, with variable physical properties, and based on mass and energy balances, was developed. The equations were implemented in the gPROMS simulator and the model parameters were estimated using the module gEST of this software, with experimental data from a large-scale coal-fired utility boiler and kinetic data from the open literature. The results showed that the model predicts the composition of the outlet combustion gas satisfactorily. (author)

  16. An experimental chamber simulating the equilibrium between radon and its daughters in mine air

    International Nuclear Information System (INIS)

    Domanski, T.; Chruscielewski, W.; Orzechowski, W.

    1981-01-01

    An experimental chamber simulating the equilibrium between radon and its daughters in uranium mine air is described. The apparatus is useful for testing track detectors, air samplers, masks and filters and for determining occupational exposures. Increasing the humidity of the chamber air and increasing the amounts of aerosol injected both increase the values of the equilibrium factor, F. The equilibrium in the chamber air decreases after the aerosol injection but by using controlled pulse injections it was shown that the stability of F could be maintained inside the chamber for 4 hours. Results are also given for the structure of the equilibrium between radon and its daughters Qsub(i)/Q 0 in the chamber air as a function of the chamber air factor F and also for the potential α-energy of unattached products in relation to the total α-potential energy of radon daughter products in the chamber air as a function of factor F. (U.K.)

  17. Study of the collecting electrode material of an extrapolation chamber by Monte Carlo simulation

    International Nuclear Information System (INIS)

    Vedovato, Uly Pita; Santos, William S.; Perini, Ana Paula; Belinato, Walmir

    2017-01-01

    In this work, the influence of different materials of the collecting electrode on the response of an extrapolation ionization chamber, was evaluated. This ionization chamber was simulated with the MCNP-4C Monte Carlo code and the spectrum of a standard diagnostic radiology beam (RQR5) was utilized. The different results are due to interactions of photons with different materials of the collecting electrode contributing with different values of energy deposited in the sensitive volume of the ionization chamber, which depends on the atomic number of the evaluated materials. The material that presented the least influence was graphite, the original constituent of the ionization chamber. (author)

  18. Mutagenicity in Salmonella of a Simulated Urban-Smog Atmosphere Generated Using a Mobile Reaction Chamber

    Science.gov (United States)

    The EPA Mobile Reaction Chamber (MRC) is a 24-foot trailer containing a 14.3-m3 Teflon lined photochemical chamber used to generate simulated urban atmospheres. Photochemistry in the MRC is catalyzed by 120 fluorescent bulbs evenly mixed with black light bulbs and UV bulbs (300 &...

  19. Hospital Costs Of Extracorporeal Life Support Therapy

    NARCIS (Netherlands)

    Oude Lansink-Hartgring, Annemieke; van den Hengel, Berber; van der Bij, Wim; Erasmus, Michiel E.; Mariani, Massimo A.; Rienstra, Michiel; Cernak, Vladimir; Vermeulen, Karin M.; van den Bergh, Walter M.

    Objectives: To conduct an exploration of the hospital costs of extracorporeal life support therapy. Extracorporeal life support seems an efficient therapy for acute, potentially reversible cardiac or respiratory failure, when conventional therapy has been inadequate, or as bridge to transplant, but

  20. Thermal System Upgrade of the Space Environment Simulation Test Chamber

    Science.gov (United States)

    Desai, Ashok B.

    1997-01-01

    The paper deals with the refurbishing and upgrade of the thermal system for the existing thermal vacuum test facility, the Space Environment Simulator, at NASA's Goddard Space Flight Center. The chamber is the largest such facility at the center. This upgrade is the third phase of the long range upgrade of the chamber that has been underway for last few years. The first phase dealt with its vacuum system, the second phase involved the GHe subsystem. The paper describes the considerations of design philosophy options for the thermal system; approaches taken and methodology applied, in the evaluation of the remaining "life" in the chamber shrouds and related equipment by conducting special tests and studies; feasibility and extent of automation, using computer interfaces and Programmable Logic Controllers in the control system and finally, matching the old components to the new ones into an integrated, highly reliable and cost effective thermal system for the facility. This is a multi-year project just started and the paper deals mainly with the plans and approaches to implement the project successfully within schedule and costs.

  1. Extracorporeal Membrane Oxygenation for Adult Community-Acquired Pneumonia: Outcomes and Predictors of Mortality.

    Science.gov (United States)

    Ramanathan, Kollengode; Tan, Chuen Seng; Rycus, Peter; MacLaren, Graeme

    2017-05-01

    Extracorporeal membrane oxygenation is a rescue therapy used to support severe cardiorespiratory failure. Data on outcomes from severe community-acquired pneumonia in adults receiving rescue extracorporeal membrane oxygenation are mainly confined to single-center experiences or specific pathogens. We examined data from the Extracorporeal Life Support Organisation registry to identify risk factors for poor outcomes in adult patients with community-acquired pneumonia. Retrospective data analysis. Extracorporeal Life Support Organization Registry database. We collected deidentified data on adult patients (> 18 yr) receiving extracorporeal membrane oxygenation for community-acquired pneumonia between 2002 and 2012. Patients with incomplete data or brain death were excluded. The primary outcome measure was in-hospital mortality. Other measurements included demographic information, pre-extracorporeal membrane oxygenation mechanical ventilation and biochemical variables, inotrope requirements, extracorporeal membrane oxygenation mode, duration, and complications. Initial univariate analysis assessed potential associations between survival and various pre-extracorporeal membrane oxygenation and extracorporeal membrane oxygenation factors. Variables with p values of less than 0.1 were considered for logistic regression analysis to identify predictors of mortality. None. One thousand fifty-five patients, who satisfied inclusion criteria, were included in the final analysis. There was an increase in the number of patients cannulated per annum over the 10-year period studied. Univariate analysis identified pre-extracorporeal membrane oxygenation and extracorporeal membrane oxygenation variables associated with high mortality. Further multiple regression analysis identified certain pre-extracorporeal membrane oxygenation factors as predictors of mortality, including duration of mechanical ventilation prior to extracorporeal membrane oxygenation, lower arterial pressure, fungal

  2. State of the art extracorporeal shock wave lithotripsy

    Energy Technology Data Exchange (ETDEWEB)

    Kandel, L.B. (State Univ. of New York at Stony Brook, Stony Brook, NY (US)); Harrison, L.H.; McCullough, D.L. (Wake Forest Univ. Medical Center, Winston-Salem, NC (US))

    1987-01-01

    This book contains 16 chapters. Some of the topics that are covered are: Extracorporeal Shock Wave Lithotripsy Development; Laser-Generated Extracorporeal Shock Wave Lithotripter; Radiation Exposure during ESWL; Caliceal Calculi; and Pediatric ESWL.

  3. State of the art extracorporeal shock wave lithotripsy

    International Nuclear Information System (INIS)

    Kandel, L.B.; Harrison, L.H.; McCullough, D.L.

    1987-01-01

    This book contains 16 chapters. Some of the topics that are covered are: Extracorporeal Shock Wave Lithotripsy Development; Laser-Generated Extracorporeal Shock Wave Lithotripter; Radiation Exposure during ESWL; Caliceal Calculi; and Pediatric ESWL

  4. [Studies of ozone formation potentials for benzene and ethylbenzene using a smog chamber and model simulation].

    Science.gov (United States)

    Jia, Long; Xu, Yong-Fu

    2014-02-01

    Ozone formation potentials from irradiations of benzene-NO(x) and ethylbenzene-NO(x) systems under the conditions of different VOC/NO(x) ratios and RH were investigated using a characterized chamber and model simulation. The repeatability of the smog chamber experiment shows that for two sets of ethylbenzene-NO(x) irradiations with similar initial concentrations and reaction conditions, such as temperature, relative humidity and relative light intensity, the largest difference in O3 between two experiments is only 4% during the whole experimental run. On the basis of smog chamber experiments, ozone formation of photo-oxidation of benzene and ethylbenzene was simulated in terms of the master chemical mechanism (MCM). The peak ozone values for benzene and ethylbenzene simulated by MCM are higher than the chamber data, and the difference between the MCM-simulated results and chamber data increases with increasing RH. Under the conditions of sunlight irradiations, with benzene and ethylbenzene concentrations being in the range of (10-50) x 10(-9) and NO(x) concentrations in the range of (10-100) x 10(-9), the 6 h ozone contributions of benzene and ethylbenzene were obtained to be (3.1-33) x 10(-9) and (2.6-122) x 10(-9), whereas the peak O3 contributions of benzene and ethylbenzene were (3.5-54) x 10(-9) and (3.8-164) x 10(-9), respectively. The MCM-simulated maximum incremental reactivity (MIR) values for benzene and ethylbenzene were 0.25/C and 0.97/C (per carbon), respectively. The maximum ozone reactivity (MOR) values for these two species were obtained to be 0.73/C and 1.03/C, respectively. The MOR value of benzene from MCM is much higher than that obtained by carter from SAPRC, indicating that SAPRC may underestimate the ozone formation potential of benzene.

  5. The effects of conventional extracorporeal circulation versus miniaturized extracorporeal circulation on microcirculation during cardiopulmonary bypass-assisted coronary artery bypass graft surgery

    NARCIS (Netherlands)

    Yuruk, Koray; Bezemer, Rick; Euser, Mariska; Milstein, Dan M. J.; de Geus, Hilde H. R.; Scholten, Evert W.; de Mol, Bas A. J. M.; Ince, Can

    2012-01-01

    OBJECTIVES: To reduce the complications associated with cardiopulmonary bypass (CPB) during cardiac surgery, many modifications have been made to conventional extracorporeal circulation systems. This trend has led to the development of miniaturized extracorporeal circulation systems. Cardiac surgery

  6. Simulation of Resistive Plate Chamber sensitivity to neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Altieri, S. E-mail: saverio.altieri@pv.infn.it; Belli, G.; Bruno, G.; Merlo, M.; Ratti, S.P.; Riccardi, C.; Torre, P.; Vitulo, P.; Abbrescia, M.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F

    2001-04-01

    The Resistive Plate Chambers (RPCs) sensitivity to neutrons has been simulated using GEANT code with MICAP and FLUKA interfaces. The calculations have been performed as a function of the neutrons energy in the range 0.02 eV-1 GeV. To evaluate the response of the detector in the LHC background environment, the neutron energy spectrum expected in the CMS muon barrel has been taken into account; a hit rate due to neutrons of about 0.6 Hz cm{sup -2} has been estimated for a 250x250 cm{sup 2} RPC in the RB1 station.

  7. Study of an extrapolation chamber in a standard diagnostic radiology beam by Monte Carlo simulation

    International Nuclear Information System (INIS)

    Vedovato, Uly Pita; Silva, Rayre Janaina Vieira; Neves, Lucio Pereira; Santos, William S.; Perini, Ana Paula; Belinato, Walmir

    2016-01-01

    In this work, we studied the influence of the components of an extrapolation ionization chamber in its response. This study was undertaken using the MCNP-5 Monte Carlo code, and the standard diagnostic radiology quality for direct beams (RQR5). Using tally F6 and 2.1 x 10"9 simulated histories, the results showed that the chamber design and material not alter significantly the energy deposited in its sensitive volume. The collecting electrode and support board were the components with more influence on the chamber response. (author)

  8. Normothermal or Hypothermal Extracorporeal Circulation Regimens in Patients with Acquired Heart Disease

    Directory of Open Access Journals (Sweden)

    V. V. Lomivorotov

    2013-01-01

    Full Text Available Background. Hypothermal extracorporeal circulation has been used in cardiosurgery over 50 years. However, recent trials have not shown its predominant effect on the protection of the brain, lung, and myocardium in patients during surgery. We have presumed that when normothermal extracorporeal circulation used in patients with acquired heart disease, its pathophysiological effect on the body is comparable with that of hypothermal extracorporeal circulation. Subjects and methods. One hundred and forty patients who were to undergo acquired heart disease correction were randomized into two equal groups: that using hypothermal or normothermal extracorporeal circulation. Perioperative troponin I and NT-proBNP concentrations, postoperative clinical course, and hospital morbidity and mortality rates were estimated. Results. There were no significant differences in the concentrations of troponin I and NT-proBNP at the study stages. In the normothermal extracorporeal circulation group patients with isolated aortic stenosis, the concentration of troponin I was higher than that in the hypothermal extracorporeal circulation group. Analyzing the postoperative course indicated that the duration of mechanical ventilation was significantly lower in the hypothermal extracorporeal circulation group than in the normothermal extracorporeal circulation group. There were no differences in hospital complications and mortality rates. Conclusion. Hypothermal versus normothermal extracorporeal circulation in the correction of acquired heart diseases has no predominant effect on tro-ponin I and NT-proBNP concentrations, postoperative clinical course, and hospital complications and mortality rates. Key words: extracorporeal circulation, hypothermia, acquired heart disease, troponin I, NT-proBNP.

  9. The simulation of resistive plate chambers in avalanche mode: charge spectra and efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Abbrescia, M. E-mail: Marcello.abbrescia@ba.infn.it; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Altieri, S.; Bruno, G.; Gianini, G.; Ratti, S.P.; Viola, L.; Vitulo, P

    1999-07-21

    A model to simulate the avalanche formation process and the induced signal in a Resistive Plate Chamber is presented. A first investigation of the effects of various parameters on the performance of this detector is reported. (author)

  10. SIMUL - a program for the simulation of interactions in the streamer chamber RISK

    International Nuclear Information System (INIS)

    Friebel, W.; Gajewski, J.; Halm, I.

    1976-08-01

    A program for the simulation of interactions in the streamer chamber RISK is described. This program allows first investigations and tests for planning and preparing experiments. In the program the trajectories of all particles taking part in the interaction are computed. Selected points are projected onto film planes serving as measurement points for the use in the geometrical reconstruction. The program is used for testing a geometry program. But it also seems to be very helpful in investigating counter and trigger constellations and in the calculation of counting rates and trigger effectivities. (author)

  11. Extracorporeal membrane oxygenation for refractory cardiac arrest

    Directory of Open Access Journals (Sweden)

    Steven A Conrad

    2017-01-01

    Full Text Available Extracorporeal cardiopulmonary resuscitation (ECPR is the use of rapid deployment venoarterial (VA extracorporeal membrane oxygenation to support systemic circulation and vital organ perfusion in patients in refractory cardiac arrest not responding to conventional cardiopulmonary resuscitation (CPR. Although prospective controlled studies are lacking, observational studies suggest improved outcomes compared with conventional CPR when ECPR is instituted within 30-60 min following cardiac arrest. Adult and pediatric patients with witnessed in-hospital and out-of-hospital cardiac arrest and good quality CPR, failure of at least 15 min of conventional resuscitation, and a potentially reversible cause for arrest are candidates. Percutaneous cannulation where feasible is rapid and can be performed by nonsurgeons (emergency physicians, intensivists, cardiologists, and interventional radiologists. Modern extracorporeal systems are easy to prime and manage and are technically easy to manage with proper training and experience. ECPR can be deployed in the emergency department for out-of-hospital arrest or in various inpatient units for in-hospital arrest. ECPR should be considered for patients with refractory cardiac arrest in hospitals with an existing extracorporeal life support program, able to provide rapid deployment of support, and with resources to provide postresuscitation evaluation and management.

  12. Digital simulation of an enrichment process for solutions by means of an advection-diffusion chamber

    International Nuclear Information System (INIS)

    Artucio, G.; Suarez, R.; Uruguay Catholic University)

    1995-01-01

    An ab-initio digital simulation of the space-time dynamics of the concentration field of a solute in an advection-diffusion chamber is done. Some questions related to the digital simulation of the concentration field using the analytical solution obtained in a previous paper are discussed

  13. Neonatal and pediatric extracorporeal membrane oxygenation in developing Latin American countries.

    Science.gov (United States)

    Kattan, Javier; González, Álvaro; Castillo, Andrés; Caneo, Luiz Fernando

    To review the principles of neonatal-pediatric extracorporeal membrane oxygenation therapy, prognosis, and its establishment in limited resource-limited countries in Latino America. The PubMed database was explored from 1985 up to the present, selecting from highly-indexed and leading Latin American journals, and Extracorporeal Life Support Organization reports. Extracorporeal membrane oxygenation provides "time" for pulmonary and cardiac rest and for recovery. It is used in the neonatal-pediatric field as a rescue therapy for more than 1300 patients with respiratory failure and around 1000 patients with cardiac diseases per year. The best results in short- and long-term survival are among patients with isolated respiratory diseases, currently established as a standard therapy in referral centers for high-risk patients. The first neonatal/pediatric extracorporeal membrane oxygenation Program in Latin America was established in Chile in 2003, which was also the first program in Latin America to affiliate with the Extracorporeal Life Support Organization. New extracorporeal membrane oxygenation programs have been developed in recent years in referral centers in Argentina, Colombia, Brazil, Mexico, Perú, Costa Rica, and Chile, which are currently funding the Latin American Extracorporeal Life Support Organization chapter. The best results in short- and long-term survival are in patients with isolated respiratory diseases. Today extracorporeal membrane oxygenation therapy is a standard therapy in some Latin American referral centers. It is hoped that these new extracorporeal membrane oxygenation centers will have a positive impact on the survival of newborns and children with respiratory or cardiac failure, and that they will be available for an increasing number of patients from this region in the near future. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  14. Neonatal and pediatric extracorporeal membrane oxygenation in developing Latin American countries

    Directory of Open Access Journals (Sweden)

    Javier Kattan

    Full Text Available Abstract Objective: To review the principles of neonatal-pediatric extracorporeal membrane oxygenation therapy, prognosis, and its establishment in limited resource-limited countries in Latino America. Sources: The PubMed database was explored from 1985 up to the present, selecting from highly-indexed and leading Latin American journals, and Extracorporeal Life Support Organization reports. Summary of the findings: Extracorporeal membrane oxygenation provides “time” for pulmonary and cardiac rest and for recovery. It is used in the neonatal-pediatric field as a rescue therapy for more than 1300 patients with respiratory failure and around 1000 patients with cardiac diseases per year. The best results in short- and long-term survival are among patients with isolated respiratory diseases, currently established as a standard therapy in referral centers for high-risk patients. The first neonatal/pediatric extracorporeal membrane oxygenation Program in Latin America was established in Chile in 2003, which was also the first program in Latin America to affiliate with the Extracorporeal Life Support Organization. New extracorporeal membrane oxygenation programs have been developed in recent years in referral centers in Argentina, Colombia, Brazil, Mexico, Perú, Costa Rica, and Chile, which are currently funding the Latin American Extracorporeal Life Support Organization chapter. Conclusions: The best results in short- and long-term survival are in patients with isolated respiratory diseases. Today extracorporeal membrane oxygenation therapy is a standard therapy in some Latin American referral centers. It is hoped that these new extracorporeal membrane oxygenation centers will have a positive impact on the survival of newborns and children with respiratory or cardiac failure, and that they will be available for an increasing number of patients from this region in the near future.

  15. Chamber simulation of photooxidation of dimethyl sulfide and isoprene in the presence of NOx

    Directory of Open Access Journals (Sweden)

    M. Jang

    2012-11-01

    Full Text Available To improve the model prediction for the formation of H2SO4 and methanesulfonic acid (MSA, aerosol-phase reactions of gaseous dimethyl sulfide (DMS oxidation products [e.g., dimethyl sulfoxide (DMSO] in aerosol have been included in the DMS kinetic model with the recently reported gas-phase reactions and their rate constants. To determine the rate constants of aerosol-phase reactions of both DMSO and its major gaseous products [e.g., dimethyl sulfone (DMSO2 and methanesulfinic acid (MSIA], DMSO was photooxidized in the presence of NOx using a 2 m3 Teflon film chamber. The rate constants tested in the DMSO kinetic mechanisms were then incorporated into the DMS photooxidation mechanism. The model simulation using the newly constructed DMS oxidation mechanims was compared to chamber data obtained from the phototoxiation of DMS in the presence of NOx. Within 120-min simulation, the predicted concentrations of MSA increase by 200–400% and those of H2SO4, by 50–200% due to aerosol-phase chemistry. This was well substantiated with experimental data. To study the effect of coexisting volatile organic compounds, the photooxidation of DMS in the presence of isoprene and NOx has been simulated using the newly constructed DMS kinetic model integrated with the Master Chemical Mechanism (MCM for isoprene oxidation, and compared to chamber data. With the high concentrations of DMS (250 ppb and isoprene (560–2248 ppb, both the model simulation and experimental data showed an increase in the yields of MSA and H2SO4 as the isoprene concentration increased.

  16. Characterization and Simulation of a New Design Parallel-Plate Ionization Chamber for CT Dosimetry at Calibration Laboratories

    Science.gov (United States)

    Perini, Ana P.; Neves, Lucio P.; Maia, Ana F.; Caldas, Linda V. E.

    2013-12-01

    In this work, a new extended-length parallel-plate ionization chamber was tested in the standard radiation qualities for computed tomography established according to the half-value layers defined at the IEC 61267 standard, at the Calibration Laboratory of the Instituto de Pesquisas Energéticas e Nucleares (IPEN). The experimental characterization was made following the IEC 61674 standard recommendations. The experimental results obtained with the ionization chamber studied in this work were compared to those obtained with a commercial pencil ionization chamber, showing a good agreement. With the use of the PENELOPE Monte Carlo code, simulations were undertaken to evaluate the influence of the cables, insulator, PMMA body, collecting electrode, guard ring, screws, as well as different materials and geometrical arrangements, on the energy deposited on the ionization chamber sensitive volume. The maximum influence observed was 13.3% for the collecting electrode, and regarding the use of different materials and design, the substitutions showed that the original project presented the most suitable configuration. The experimental and simulated results obtained in this work show that this ionization chamber has appropriate characteristics to be used at calibration laboratories, for dosimetry in standard computed tomography and diagnostic radiology quality beams.

  17. Accurate simulation of ionisation chamber response with the Monte Carlo code PENELOPE

    International Nuclear Information System (INIS)

    Sempau, Josep; Andreo, Pedro

    2011-01-01

    Ionisation chambers (IC) are routinely used in hospitals for the dosimetry of the photon and electron beams used for radiotherapy treatments. The determination of absorbed dose to water from the absorbed dose to the air filling the cavity requires the introduction of stopping power ratios and perturbation factors, which account for the disturbance caused by the presence of the chamber. Although this may seem a problem readily amenable to Monte Carlo simulation, the fact is that the accurate determination of IC response has been, for various decades, one of the most important challenges of the simulation of electromagnetic showers. The main difficulty stems from the use of condensed history techniques for electron and positron transport. This approach, which involves grouping a large number of interactions into a single artificial event, is known to produce the so-called interface effects when particles travel across surfaces separating different media. These effects can be sizeable when the electron step length is not negligible compared to the size of the region being crossed, as it is the case with the cavity of an IC. The artefact, which becomes apparent when the chamber response shows a marked dependence on the adopted step size, can be palliated with the use of sophisticated electron transport algorithms. These topics are discussed in the context of the transport model implemented in the PENELOPE code. The degree of violation of the Fano theorem for a simple, planar geometry, is used as a measure of the stability of the algorithm with respect to variations of the electron step length, thus assessing the 'quality' of its condensed history scheme. It is shown that, with a suitable choice of transport parameters, PENELOPE simulates IC response with an accuracy of the order of 0.1%.

  18. Accurate simulation of ionization chamber response with the Monte Carlo code PENELOPE

    International Nuclear Information System (INIS)

    Sempau, Josep

    2010-01-01

    Full text. Ionization chambers (IC) are routinely used in hospitals for the dosimetry of the photon and electron beams used for radiotherapy treatments. The determination of absorbed dose to water from the absorbed dose to the air filling the cavity requires the introduction of stopping power ratios and perturbation factors, which account for the disturbance caused by the presence of the chamber. Although this may seem a problem readily amenable to Monte Carlo simulation, the fact is that the accurate determination of IC response has been, during the last 20 years, one of the most important challenges of the simulation of electromagnetic showers. The main difficulty stems from the use of condensed history techniques for electron and positron transport. This approach, which involves grouping a large number of interactions into a single artificial event, is known to produce the so-called interface effects when particles travel across surfaces separating different media. These effects are extremely important when the electron step length is not negligible compared to the size of the region being crossed, as it is the case with the cavity of an IC. The artifact, which becomes apparent when the chamber response shows a marked dependence on the adopted step size, can be palliated with the use of sophisticated electron transport algorithms. These topics will be discussed in the context of the transport model implemented in the Penelope code. The degree of violation of the Fano theorem for a simple, planar geometry, will be used as a measure of the stability of the algorithm with respect to variations of the electron step length, thus assessing the 'quality' of its condensed history scheme. It will be shown that, with a suitable choice of transport parameters, Penelope can simulate IC response with an accuracy of the order of 0.1%. (author)

  19. Guidelines for reporting case studies on extracorporeal treatments in poisonings

    DEFF Research Database (Denmark)

    Lavergne, Valéry; Ouellet, Georges; Bouchard, Josée

    2014-01-01

    A literature review performed by the EXtracorporeal TReatments In Poisoning (EXTRIP) workgroup highlighted deficiencies in the existing literature, especially the reporting of case studies. Although general reporting guidelines exist for case studies, there are none in the specific field...... of extracorporeal treatments in toxicology. Our goal was to construct and propose a checklist that systematically outlines the minimum essential items to be reported in a case study of poisoned patients undergoing extracorporeal treatments. Through a modified two-round Delphi technique, panelists (mostly chosen...... reports containing data on extracorporeal treatments in poisoning published in Medline in 2011 were reviewed during the external validation rounds. Twenty-one panelists (20 from the EXTRIP workgroup and an invited expert on pharmacology reporting guidelines) participated in the modified Delphi technique...

  20. Extracorporeal Shockwave Lithotripsy of Primary Intrahepatic Stones

    Science.gov (United States)

    Kim, Myung Hwan; Lee, Sung Koo; Min, Young Il; Lee, Mun Gyu; Sung, Kyu Bo; Cho, Kyung Sik; Lee, Sung Gyu; Min, Pyung Chul

    1992-01-01

    Extracorporeal shockwave lithothripsy (ESWL) was performed in intrahepatic stone patients (n = 18) by Dornier MPL 9,000 with ultrasound guidance. The patients had T-tube (n = 9) or percutaneous transhepatic biliary drainge tube (n = 9). Average treatment session was four and shock-wave numbers were in the range of 3,064 to 12,000 (average 6,288 shocks). Intrahepatic stones were removed completely in 16 patients over a 3 month period by ESWL and combined stone extraction maneuver such as cholangioscopic or interventional radiologic method. Extracorporeal shockwave lithothripsy was very helpful in facilitating extraction of stones in unfavorable locations or located above the severe stricture. In summary, extracorporeal Shockwave lithotripsy, followed by percutaneous stone extraction, will provide an improvement in the success rate and duration of treatment required for complete removal of primary hepatolithiasis. PMID:1477027

  1. Review of 1,000 consecutive extracorporeal membrane oxygenation runs as a quality initiative.

    Science.gov (United States)

    Lovvorn, Harold N; Hardison, Daphne C; Chen, Heidi; Westrick, Ashly C; Danko, Melissa E; Bridges, Brian C; Walsh, William F; Pietsch, John B

    2017-08-01

    Extracorporeal membrane oxygenation is a resource-intensive mode of life-support potentially applicable when conventional therapies fail. Given the initial success of extracorporeal membrane oxygenation to support neonates and infants in the 1980s, indications have expanded to include adolescents, adults, and selected moribund patients during cardiopulmonary resuscitation. This single-institution analysis was conducted to evaluate programmatic growth, outcomes, and risk for death despite extracorporeal membrane oxygenation across all ages and diseases. Beginning in 1989, we registered prospectively all extracorporeal membrane oxygenation patient data with the Extracorporeal Life Support Organization. We queried this registry for our institution-specific data to compare the parameter of "discharge alive" between age groups (neonatal, pediatric, adult), disease groups (respiratory, cardiac, cardiopulmonary resuscitation), and modes of extracorporeal membrane oxygenation (veno-venous; veno-arterial). Extracorporeal membrane oxygenation-specific complications (mechanical, hemorrhagic, neurologic, renal, cardiovascular, pulmonary, infectious, metabolic) were analyzed similarly. Descriptive statistics, Kaplan-Meier, and linear regression analyses were conducted. After 1,052 extracorporeal membrane oxygenation runs, indications have expanded to include adults, to supplement cardiopulmonary resuscitation, to support hemodialysis in neonates and plasmapheresis in children, and to bridge all age patients to heart and lung transplant. Overall survival to discharge was 52% and was better for respiratory diseases (P < .001). Probability of individual survival decreased to <50% if pre-extracorporeal membrane oxygenation mechanical ventilation exceeded respectively 123 hours for cardiac, 166 hours for cardiopulmonary resuscitation, and 183 hours for respiratory diseases (P = .013). Complications occurred most commonly among cardiac and cardiopulmonary resuscitation runs

  2. Extracorporeal shock wave lithotripsy of biliary and pancreatic stones

    NARCIS (Netherlands)

    R. den Toom (Rene)

    1993-01-01

    textabstractThe aim of the study was to answer the following questions: Is extracorporeal shock wave lithotripsy for gallbladder stones a safe and effective therapy? (Chapter 2) Is simultaneous treatment with extracorporeal shock wave lithotripsy and the solvent methyl te.rt-butyl ether feasible,

  3. Neonatal and pediatric extracorporeal membrane oxygenation in developing Latin American countries

    OpenAIRE

    Kattan, Javier; González, Álvaro; Castillo, Andrés; Caneo, Luiz Fernando

    2017-01-01

    Objective: To review the principles of neonatal‐pediatric extracorporeal membrane oxygenation therapy, prognosis, and its establishment in limited resource‐limited countries in Latino America. Sources: The PubMed database was explored from 1985 up to the present, selecting from highly‐indexed and leading Latin American journals, and Extracorporeal Life Support Organization reports. Summary of the findings: Extracorporeal membrane oxygenation provides “time” for pulmonary and cardiac res...

  4. Enhancement of precision and accuracy by Monte-Carlo simulation of a well-type pressurized ionization chamber used in radionuclide metrology

    International Nuclear Information System (INIS)

    Kryeziu, D.

    2006-09-01

    The aim of this work was to test and validate the Monte-Carlo (MC) ionization chamber simulation method in calculating the activity of radioactive solutions. This is required when no or not sufficient experimental calibration figures are available as well as to improve the accuracy of activity measurements for other radionuclides. Well-type or 4π γ ISOCAL IV ionization chambers (IC) are widely used in many national standard laboratories around the world. As secondary standard measuring systems these radionuclide calibrators serve to maintain measurement consistency checks and to ensure the quality of standards disseminated to users for a wide range of radionuclide where many of them are with special interest in nuclear medicine as well as in different applications on radionuclide metrology. For the studied radionuclides the calibration figures (efficiencies) and their respective volume correction factors are determined by using the PENELOPE MC computer code system. The ISOCAL IV IC filled with nitrogen gas at approximately 1 MPa is simulated. The simulated models of the chamber are designed by means of reduced quadric equation and applying the appropriate mathematical transformations. The simulations are done for various container geometries of the standard solution which take forms of: i) sealed Jena glass 5 ml PTB standard ampoule, ii) 10 ml (P6) vial and iii) 10 R Schott Type 1+ vial. Simulation of the ISOCAL IV IC is explained. The effect of density variation of the nitrogen filling gas on the sensitivity of the chamber is investigated. The code is also used to examine the effects of using lead and copper shields as well as to evaluate the sensitivity of the chamber to electrons and positrons. Validation of the Monte-Carlo simulation method has been proved by comparing the Monte-Carlo simulation calculated and experimental calibration figures available from the National Physical Laboratory (NPL) England which are deduced from the absolute activity

  5. Extracorporeal shockwave for chronic patellar tendinopathy.

    Science.gov (United States)

    Wang, Ching-Jen; Ko, Jih-Yang; Chan, Yi-Sheng; Weng, Lin-Hsiu; Hsu, Shan-Lin

    2007-06-01

    Chronic patellar tendinopathy is an overuse syndrome with pathologic changes similar to tendinopathies of the shoulder, elbow, and heel. Extracorporeal shockwave was shown effective in many tendinopathies. Extracorporeal shockwave therapy may be more effective than conservative treatment for chronic patellar tendinopathy. Randomized controlled clinical trial; Level of evidence, 2. This study consisted of 27 patients (30 knees) in the study group and 23 patients (24 knees) in the control group. In the study group, patients were treated with 1500 impulses of extracorporeal shockwave at 14 KV (equivalent to 0.18 mJ/mm(2) energy flux density) to the affected knee at a single session. Patients in the control group were treated with conservative treatments including nonsteroidal anti-inflammatory drugs, physiotherapy, exercise program, and the use of a knee strap. The evaluation parameters included pain score, Victorian Institute of Sports Assessment score, and ultrasonographic examination at 1, 3, 6, and 12 months and then once a year. At the 2- to 3-year follow-up, the overall results for the study group were 43% excellent, 47% good, 10% fair, and none poor. For the control group, the results were none excellent, 50% good, 25% fair, and 25% poor. The mean Victorian Institute of Sports Assessment scores were 42.57 +/- 10.22 and 39.25 +/- 10.85, respectively, before treatment (P = .129) and 92.0 +/- 10.17 and 41.04 +/- 10.96, respectively, after treatment (P Extracorporeal shockwave therapy appeared to be more effective and safer than traditional conservative treatments in the management of patients with chronic patellar tendinopathy.

  6. Extracorporeal membrane oxygenation (ECMO)

    African Journals Online (AJOL)

    Extracorporeal membrane oxygenation (ECMO) is not a novel therapy in the true sense of the ... Intention-to-treat analysis showed benefit for ECMO, with a relative risk ... no doubt that VV-ECMO is an advance in medical technology, and that.

  7. Can low-intensity extracorporeal shockwave therapy improve erectile dysfunction?

    DEFF Research Database (Denmark)

    Olsen, Anne B; Persiani, Marie; Boie, Sidsel

    2015-01-01

    OBJECTIVE: The aim of this study was to investigate whether low-intensity extracorporeal shockwave therapy (LI-ESWT) can be used as a treatment for men with erectile dysfunction of organic origin. MATERIALS AND METHODS: This prospective, randomized, blinded, placebo-controlled study included 112 ...... are needed. KEYWORDS: Erectile dysfunction; extracorporeal shockwave; penis...

  8. Simulation of the Interaction of X-rays with a Gas in an Ionization Chamber by the Monte Carlo Method

    International Nuclear Information System (INIS)

    Grau Carles, A.; Garcia Gomez-Tejedor, G.

    2001-01-01

    The final objective of any ionization chamber is the measurement of the energy amount or radiation dose absorbed by the gas into the chamber. The final value depends on the composition of the gas, its density and temperature, the ionization chamber geometry, and type and intensity of the radiation. We describe a Monte Carlo simulation method, which allows one to compute the dose absorbed by the gas for a X-ray beam. Verification of model has been carried out by simulating the attenuation of standard X-ray radiation through the half value layers established in the ISO 4037 report, while assuming a Weibull type energy distribution for the incident photons. (Author) 6 refs

  9. A novel approach to predict the stability limits of combustion chambers with large eddy simulation

    Science.gov (United States)

    Pritz, B.; Magagnato, F.; Gabi, M.

    2010-06-01

    Lean premixed combustion, which allows for reducing the production of thermal NOx, is prone to combustion instabilities. There is an extensive research to develop a reduced physical model, which allows — without time-consuming measurements — to calculate the resonance characteristics of a combustion system consisting of Helmholtz resonator type components (burner plenum, combustion chamber). For the formulation of this model numerical investigations by means of compressible Large Eddy Simulation (LES) were carried out. In these investigations the flow in the combustion chamber is isotherm, non-reacting and excited with a sinusoidal mass flow rate. Firstly a combustion chamber as a single resonator subsequently a coupled system of a burner plenum and a combustion chamber were investigated. In this paper the results of additional investigations of the single resonator are presented. The flow in the combustion chamber was investigated without excitation at the inlet. It was detected, that the mass flow rate at the outlet cross section is pulsating once the flow in the chamber is turbulent. The fast Fourier transform of the signal showed that the dominant mode is at the resonance frequency of the combustion chamber. This result sheds light on a very important source of self-excited combustion instabilities. Furthermore the LES can provide not only the damping ratio for the analytical model but the eigenfrequency of the resonator also.

  10. Extracorporeal Membrane Oxygenation for Complicated Scrub Typhus

    Directory of Open Access Journals (Sweden)

    Eun Sun Kim

    Full Text Available Scrub typhus is a mite-borne infectious disease caused by Orientia tsutsugamushi . Although early diagnosis and appropriate antibiotic therapy improve the prognosis for the majority of patients, life-threatening complications are not uncommon. Here, we present a case of successful veno-veno-type extracorporeal membrane oxygenation for scrub typhus-induced complications, including acute respiratory distress syndrome, myocarditis and multi-organ dysfunction. To our knowledge, this is the first case report of successful extracorporeal membrane oxygenation in complicated scrub typhus in Korea.

  11. Extracorporeal Cardiopulmonary Resuscitation in the Pediatric Cardiac Population: In Search of a Standard of Care.

    Science.gov (United States)

    Lasa, Javier J; Jain, Parag; Raymond, Tia T; Minard, Charles G; Topjian, Alexis; Nadkarni, Vinay; Gaies, Michael; Bembea, Melania; Checchia, Paul A; Shekerdemian, Lara S; Thiagarajan, Ravi

    2018-02-01

    Although clinical and pharmacologic guidelines exist for the practice of cardiopulmonary resuscitation in children (Pediatric Advanced Life Support), the practice of extracorporeal cardiopulmonary resuscitation in pediatric cardiac patients remains without universally accepted standards. We aim to explore variation in extracorporeal cardiopulmonary resuscitation procedures by surveying clinicians who care for this high-risk patient population. A 28-item cross-sectional survey was distributed via a web-based platform to clinicians focusing on cardiopulmonary resuscitation practices and extracorporeal membrane oxygenation team dynamics immediately prior to extracorporeal membrane oxygenation cannulation. Pediatric hospitals providing extracorporeal mechanical support services to patients with congenital and/or acquired heart disease. Critical care/cardiology specialist physicians, cardiothoracic surgeons, advanced practice nurse practitioners, respiratory therapists, and extracorporeal membrane oxygenation specialists. None. Survey web links were distributed over a 2-month period with critical care and/or cardiology physicians comprising the majority of respondents (75%). Nearly all respondents practice at academic/teaching institutions (97%), 89% were from U.S./Canadian institutions and 56% reported less than 10 years of clinical experience. During extracorporeal cardiopulmonary resuscitation, a majority of respondents reported adherence to guideline recommendations for epinephrine bolus dosing (64%). Conversely, 19% reported using only one to three epinephrine bolus doses regardless of extracorporeal cardiopulmonary resuscitation duration. Inotropic support is held after extracorporeal membrane oxygenation cannulation "most of the time" by 58% of respondents and 94% report using afterload reducing/antihypertensive agents "some" to "most of the time" after achieving full extracorporeal membrane oxygenation support. Interruptions in chest compressions are common

  12. Ionization chamber correction factors for MR-linacs.

    Science.gov (United States)

    Pojtinger, Stefan; Dohm, Oliver Steffen; Kapsch, Ralf-Peter; Thorwarth, Daniela

    2018-06-07

    Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B . The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0-2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

  13. Ionization chamber correction factors for MR-linacs

    Science.gov (United States)

    Pojtinger, Stefan; Steffen Dohm, Oliver; Kapsch, Ralf-Peter; Thorwarth, Daniela

    2018-06-01

    Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B. The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0–2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

  14. Extracorporeal Treatment for Lithium Poisoning: Systematic Review and Recommendations from the EXTRIP Workgroup

    Science.gov (United States)

    Decker, Brian S.; Goldfarb, David S.; Dargan, Paul I.; Friesen, Marjorie; Gosselin, Sophie; Hoffman, Robert S.; Lavergne, Valéry; Nolin, Thomas D.

    2015-01-01

    The Extracorporeal Treatments in Poisoning Workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments in poisoning. Here, the EXTRIP workgroup presents its recommendations for lithium poisoning. After a systematic literature search, clinical and toxicokinetic data were extracted and summarized following a predetermined format. The entire workgroup voted through a two-round modified Delphi method to reach a consensus on voting statements. A RAND/UCLA Appropriateness Method was used to quantify disagreement, and anonymous votes were compiled and discussed in person. A second vote was conducted to determine the final workgroup recommendations. In total, 166 articles met inclusion criteria, which were mostly case reports, yielding a very low quality of evidence for all recommendations. A total of 418 patients were reviewed, 228 of which allowed extraction of patient-level data. The workgroup concluded that lithium is dialyzable (Level of evidence=A) and made the following recommendations: Extracorporeal treatment is recommended in severe lithium poisoning (1D). Extracorporeal treatment is recommended if kidney function is impaired and the [Li+] is >4.0 mEq/L, or in the presence of a decreased level of consciousness, seizures, or life-threatening dysrhythmias irrespective of the [Li+] (1D). Extracorporeal treatment is suggested if the [Li+] is >5.0 mEq/L, significant confusion is present, or the expected time to reduce the [Li+] to 36 hours (2D). Extracorporeal treatment should be continued until clinical improvement is apparent or [Li+] is treatments should be continued for a minimum of 6 hours if the [Li+] is not readily measurable (1D). Hemodialysis is the preferred extracorporeal treatment (1D), but continuous RRT is an acceptable alternative (1D). The workgroup supported the use of extracorporeal treatment in severe lithium poisoning. Clinical decisions on when to use extracorporeal treatment should take into account the

  15. Use of Hypertonic Sodium Chloride Solution at Surgery under Extracorporeal Circulation

    Directory of Open Access Journals (Sweden)

    V. V. Lomivorotov

    2012-01-01

    Full Text Available The paper analyzes the data available in the references on different aspects of using hypertonic sodium chloride solution during surgery under extracorporeal circulation in cardiosurgical care. The hypertonic solution is shown to lower positive fluid balance in the perioperative period, to increase cardiac output with simultaneously decreased vascular resistance, to improve lung oxygenating function, and to normalize tissue blood circulation and neurological status in patients exposed to artificial perfusion. There is evidence for its effect on the immune system and capillary endothelium. It is suggested that it is necessary to study the effect of the hypertonic solution on the incidence of complications and death rates during surgery under extracorporeal circulation and it is proposed to use the solution under long-term extracorporeal circulation. Key words: hypertonic saline, sodium chloride, extracorporeal circulation.

  16. Extracorporeal irradiation -Physicist perspective

    International Nuclear Information System (INIS)

    Vijayaprabhu, N.; Saravanan, K.S.; Gunaseelan; Vivekanandam, S.; Reddy, K.S.; Parthasarathy; Mourougan, S.; Elangovan, K.

    2008-01-01

    Extracorporeal irradiation (ECI) involves irradiation of body tissues, particularly malignant bones of the extremities, outside the body. This involves en bloc resection of the tumour, extracorporeal irradiation of the bone segment with a single dose of 50 Gy or more, and reimplantation of the irradiated bone with fixation devices. Bone tumours like Ewing's Sarcoma, Chondrosarcoma and Oesteosarcoma; in the involved sites like femur, tibia, humerus, ilium and sacrum can be treated with ECI. The reimplanted bone simply acts as a framework for appositional bone growth from surrounding healthy bones. The conventional indications for postoperative irradiation are still applied. The major advantages of ECI are the precise anatomic fit of the reimplanted bone segment, preservation of joint mobility and its potential in avoiding the growth discrepancy commonly seen in prosthetic replacement. The use of ECI was first described in 1968 and practiced in Australia since 1996. In our center, we have completed six ECIs

  17. Extracorporeal Treatment in Phenytoin Poisoning

    DEFF Research Database (Denmark)

    Anseeuw, Kurt; Mowry, James B; Burdmann, Emmanuel A

    2016-01-01

    The Extracorporeal Treatments in Poisoning (EXTRIP) Workgroup conducted a systematic literature review using a standardized process to develop evidence-based recommendations on the use of extracorporeal treatment (ECTR) in patients with phenytoin poisoning. The authors reviewed all articles......) despite its high protein binding and made the following recommendations. ECTR would be reasonable in select cases of severe phenytoin poisoning (neutral recommendation, 3D). ECTR is suggested if prolonged coma is present or expected (graded 2D) and it would be reasonable if prolonged incapacitating ataxia...... is present or expected (graded 3D). If ECTR is used, it should be discontinued when clinical improvement is apparent (graded 1D). The preferred ECTR modality in phenytoin poisoning is intermittent hemodialysis (graded 1D), but hemoperfusion is an acceptable alternative if hemodialysis is not available...

  18. Extracorporeal treatment for barbiturate poisoning

    DEFF Research Database (Denmark)

    Mactier, Robert; Laliberté, Martin; Mardini, Joelle

    2014-01-01

    The EXTRIP (Extracorporeal Treatments in Poisoning) Workgroup conducted a systematic review of barbiturate poisoning using a standardized evidence-based process to provide recommendations on the use of extracorporeal treatment (ECTR) in patients with barbiturate poisoning. The authors reviewed all...... treatment should be continued during ECTR. (4) Cessation of ECTR is indicated when clinical improvement is apparent. This report provides detailed descriptions of the rationale for all recommendations. In summary, patients with long-acting barbiturate poisoning should be treated with ECTR provided at least......-acting barbiturates are dialyzable and short-acting barbiturates are moderately dialyzable. Four key recommendations were made. (1) The use of ECTR should be restricted to cases of severe long-acting barbiturate poisoning. (2) The indications for ECTR in this setting are the presence of prolonged coma, respiratory...

  19. Measurements and Simulations of Ionization Chamber Signals in Mixed Radiation Fields for the LHC BLM System

    CERN Document Server

    Dehning, B; Ferioli, G; Holzer, EB; Stockner, M

    2006-01-01

    The LHC beam loss monitoring (BLM) system must prevent the super conducting magnets from quenching and protect the machine components from damage. The main monitor type is an ionization chamber. About 4000 of them will be installed around the ring. The lost beam particles initiate hadronic showers through the magnets, which are measured by the monitors installed outside of the cryostat around each quadrupole magnet. They probe the far transverse tail of the hadronic shower. The specification for the BLM system includes a factor of two absolute precision on the prediction of the quench levels. To reach this accuracy a number of simulations are being combined to calibrate the monitor signals. To validate the monitor calibration the simulations are compared with test measurements. This paper will focus on the simulated prediction of the development of the hadronic shower tails and the signal response of ionization chambers to various particle types and energies. Test measurements have been performed at CERN and ...

  20. Development of simulated and ovine models of extracorporeal life support to improve understanding of circuit-host interactions.

    Science.gov (United States)

    Shekar, Kiran; Fung, Yoke L; Diab, Sara; Mullany, Daniel V; McDonald, Charles I; Dunster, Kimble R; Fisquet, Stephanie; Platts, David G; Stewart, David; Wallis, Steven C; Smith, Maree T; Roberts, Jason A; Fraser, John F

    2012-06-01

    Extracorporeal life support (ECLS) is a lifesaving technology that is being increasingly used in patients with severe cardiorespiratory failure. However, ECLS is not without risks. The biosynthetic interface between the patient and the circuit can significantly alter inflammation, coagulation, pharmacokinetics and disposition of trace elements. The relative contributions of the pump, disease and patient in propagating these alterations are difficult to quantify in critically ill patients with multiple organ failure. To design a model where the relevance of individual components could be assessed, in isolation and in combination. Four ECLS models were developed and tested - an in-vitro simulated ECLS circuit; and ECLS in healthy sheep, sheep with acute lung injury (ALI), and sheep with ALI together with transfusion of old or new blood. Successful design of in-vitro and in-vivo models. We successfully conducted multiple experiments in the simulated circuits and ECLS runs in healthy and ALI sheep. We obtained preliminary data on inflammation, coagulation, histology, pharmacokinetics and trace element disposition during ECLS. The establishment of in-vitro and in-vivo models provides a powerful means for enhancing knowledge of the pathophysiology associated with ECLS and identification of key factors likely to influence patient outcomes. A clearer description of the contribution of disease and therapeutic interventions may allow improved design of equipment, membranes, medicines and physiological goals for improved patient care.

  1. Extracorporeal CO2 removal: Technical and physiological fundaments and principal indications.

    Science.gov (United States)

    Romay, E; Ferrer, R

    2016-01-01

    In recent years, technological improvements have reduced the complexity of extracorporeal membrane oxygenation devices. This have enabled the development of specific devices for the extracorporeal removal of CO2. These devices have a simpler configuration than extracorporeal membrane oxygenation devices and uses lower blood flows which could reduce the potential complications. Experimental studies have demonstrated the feasibility, efficacy and safety of extracorporeal removal of CO2 and some of its effects in humans. This technique was initially conceived as an adjunct therapy in patients with severe acute respiratory distress syndrome, as a tool to optimize protective ventilation. More recently, the use of this technique has allowed the emergence of a relatively new concept called "tra-protective ventilation"whose effects are still to be determined. In addition, the extracorporeal removal of CO2 has been used in patients with exacerbated hypercapnic respiratory failure with promising results. In this review we will describe the physiological and technical fundamentals of this therapy and its variants as well as an overview of the available clinical evidence, focused on its current potential. Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

  2. Significant reduction in blood loss in patients undergoing minimal extracorporeal circulation

    NARCIS (Netherlands)

    Gerritsen, W. B.; van Boven, W. J.; Smelt, M.; Morshuis, W. J.; van Dongen, H. P.; Haas, F. J.; Aarts, L. P.

    2006-01-01

    Several recent studies have shown differences in blood loss and allogeneic transfusion requirements between on-pump and off-pump coronary artery bypass grafting (CABG). Recently a new concept, the mini-extracorporeal circulation, was introduced to minimize the side effects of extracorporeal

  3. SU-E-T-242: Monte Carlo Simulations Used to Test the Perturbation of a Reference Ion Chamber Prototype Used for Small Fields

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Quino, L; Calvo, O; Huerta, C; DeWeese, M [Midsouth Radation Physics, Little Rock, AR (United States)

    2014-06-01

    Purpose: To study the perturbation due to the use of a novel Reference Ion Chamber designed to measure small field dosimetry (KermaX Plus C by IBA). Methods: Using the Phase-space files for TrueBeam photon beams available by Varian in IAEA-compliant format for 6 and 15 MV. Monte Carlo simulations were performed using BEAMnrc and DOSXYZnrc to investigate the perturbation introduced by a reference chamber into the PDDs and profiles measured in water tank. Field sizes ranging from 1×1, 2×2,3×3, 5×5 cm2 were simulated for both energies with and without a 0.5 mm foil of Aluminum which is equivalent to the attenuation equivalent of the reference chamber specifications in a water phantom of 30×30×30 cm3 and a pixel resolution of 2 mm. The PDDs, profiles, and gamma analysis of the simulations were performed as well as a energy spectrum analysis of the phase-space files generated during the simulation. Results: Examination of the energy spectrum analysis performed shown a very small increment of the energy spectrum at the build-up region but no difference is appreciated after dmax. The PDD, profiles and gamma analysis had shown a very good agreement among the simulations with and without the Al foil, with a gamma analysis with a criterion of 2% and 2mm resulting in 99.9% of the points passing this criterion. Conclusion: This work indicates the potential benefits of using the KermaX Plus C as reference chamber in the measurement of PDD and Profiles for small fields since the perturbation due to in the presence of the chamber the perturbation is minimal and the chamber can be considered transparent to the photon beam.

  4. Extracorporeal treatment for tricyclic antidepressant poisoning

    DEFF Research Database (Denmark)

    Yates, Christopher; Galvao, Tais; Sowinski, Kevin M

    2014-01-01

    The Extracorporeal Treatments In Poisoning (EXTRIP) workgroup was formed to provide recommendations on the use of extracorporeal treatments (ECTR) in poisoning. Here, the workgroup presents its results for tricyclic antidepressants (TCAs). After an extensive literature search, using a predefined...... methodology, the subgroup responsible for this poison reviewed the articles, extracted the data, summarized findings, and proposed structured voting statements following a predetermined format. A two-round modified Delphi method was chosen to reach a consensus on voting statements and RAND...... yielding a very low quality of evidence for all recommendations. Data on 108 patients, including 12 fatalities, were abstracted. The workgroup concluded that TCAs are not dialyzable and made the following recommendation: ECTR is not recommended in severe TCA poisoning (1D). The workgroup considers...

  5. Extracorporeal Treatment for Lithium Poisoning: Systematic Review and Recommendations from the EXTRIP Workgroup.

    Science.gov (United States)

    Decker, Brian S; Goldfarb, David S; Dargan, Paul I; Friesen, Marjorie; Gosselin, Sophie; Hoffman, Robert S; Lavergne, Valéry; Nolin, Thomas D; Ghannoum, Marc

    2015-05-07

    The Extracorporeal Treatments in Poisoning Workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments in poisoning. Here, the EXTRIP workgroup presents its recommendations for lithium poisoning. After a systematic literature search, clinical and toxicokinetic data were extracted and summarized following a predetermined format. The entire workgroup voted through a two-round modified Delphi method to reach a consensus on voting statements. A RAND/UCLA Appropriateness Method was used to quantify disagreement, and anonymous votes were compiled and discussed in person. A second vote was conducted to determine the final workgroup recommendations. In total, 166 articles met inclusion criteria, which were mostly case reports, yielding a very low quality of evidence for all recommendations. A total of 418 patients were reviewed, 228 of which allowed extraction of patient-level data. The workgroup concluded that lithium is dialyzable (Level of evidence=A) and made the following recommendations: Extracorporeal treatment is recommended in severe lithium poisoning (1D). Extracorporeal treatment is recommended if kidney function is impaired and the [Li(+)] is >4.0 mEq/L, or in the presence of a decreased level of consciousness, seizures, or life-threatening dysrhythmias irrespective of the [Li(+)] (1D). Extracorporeal treatment is suggested if the [Li(+)] is >5.0 mEq/L, significant confusion is present, or the expected time to reduce the [Li(+)] to 36 hours (2D). Extracorporeal treatment should be continued until clinical improvement is apparent or [Li(+)] is lithium poisoning. Clinical decisions on when to use extracorporeal treatment should take into account the [Li(+)], kidney function, pattern of lithium toxicity, patient's clinical status, and availability of extracorporeal treatments. Copyright © 2015 by the American Society of Nephrology.

  6. Semi-automated operation of Mars Climate Simulation chamber - MCSC modelled for biological experiments

    Science.gov (United States)

    Tarasashvili, M. V.; Sabashvili, Sh. A.; Tsereteli, S. L.; Aleksidze, N. D.; Dalakishvili, O.

    2017-10-01

    The Mars Climate Simulation Chamber (MCSC) (GEO PAT 12 522/01) is designed for the investigation of the possible past and present habitability of Mars, as well as for the solution of practical tasks necessary for the colonization and Terraformation of the Planet. There are specific tasks such as the experimental investigation of the biological parameters that allow many terrestrial organisms to adapt to the imitated Martian conditions: chemistry of the ground, atmosphere, temperature, radiation, etc. MCSC is set for the simulation of the conduction of various biological experiments, as well as the selection of extremophile microorganisms for the possible Settlement, Ecopoesis and/or Terraformation purposes and investigation of their physiological functions. For long-term purposes, it is possible to cultivate genetically modified organisms (e.g., plants) adapted to the Martian conditions for future Martian agriculture to sustain human Mars missions and permanent settlements. The size of the chamber allows preliminary testing of the functionality of space-station mini-models and personal protection devices such as space-suits, covering and building materials and other structures. The reliability of the experimental biotechnological materials can also be tested over a period of years. Complex and thorough research has been performed to acquire the most appropriate technical tools for the accurate engineering of the MCSC and precious programmed simulation of Martian environmental conditions. This paper describes the construction and technical details of the equipment of the MCSC, which allows its semi-automated, long-term operation.

  7. [Extracorporeal photopheresis as an alternative therapy for drug-resistant graft versus host disease: three cases].

    Science.gov (United States)

    D'incan, M; Kanold, J; Halle, P; De Lumley, L; Souteyrand, P; Deméocq, F

    2000-02-01

    Graft versus host reaction is a life-threatening complication of allogenic bone marrow transplantation. Extracorporeal photopheresis has been used for some years in the treatment of graft versus host reaction. We report on three children treated with extracorporeal photopheresis for a graft versus host reaction resistant to immunosuppresive drugs. Three children with a graft versus host reaction were submitted to 18, 30 and 46 extracorporeal photopheresis courses respectively. In the same time, the other immunosuppressive treatments were tapered or definitively stopped (ciclosporin). A dramatic improvement of cutaneous status and biological data was observed after the first courses. However, the extracorporeal photopheresis treatment did not improve the mucous lesions. No serious adverse effect was encountered. As published elsewhere, extracorporeal photopheresis was effective on the graft versus host reaction lichenoid cutaneous lesions and in case of visceral involvement. In all of our cases, the immunosuppressive drug could have been tapered. No adverse event was observed. Thus, extracorporeal photopheresis should be indicated in case of resistance to immunosuppressive drugs.

  8. Superior Mesenteric Artery Dissection after Extracorporeal Shockwave Lithotripsy

    Directory of Open Access Journals (Sweden)

    Christos Bakoyiannis

    2012-01-01

    Full Text Available The use of shockwave lithotripsy is currently the mainstay of treatment in renal calculosis. Several complications including vessel injuries have been implied to extracorporeal shockwave lithotripsy. We report an isolated dissection of the superior mesenteric artery in a 60-year-old male presenting with abdominal pain which occurred three days after extracorporeal shockwave lithotripsy. The patient was treated conservatively and the abdominal pain subsided 24 hours later. The patient's history, the course of his disease, and the timing may suggest a correlation between the dissection and the ESWL.

  9. Ballistic-neutralized chamber transport of intense heavy ion beams

    International Nuclear Information System (INIS)

    Rose, D.V.; Welch, D.R.; Oliver, B.V.; Clark, R.E.; Sharp, W.M.; Friedman, A.

    2001-01-01

    Two-dimensional particle-in-cell simulations of intense heavy ion beams propagating in an inertial confinement fusion (ICF) reactor chamber are presented. The ballistic-neutralized transport scheme studied uses 4 GeV Pb +1 ion beams injected into a low-density, gas-filled reactor chamber and the beam is ballistically focused onto an ICF target before entering the chamber. Charge and current neutralization of the beam is provided by the low-density background gas. The ballistic-neutralized simulations include stripping of the beam ions as the beam traverses the chamber as well as ionization of the background plasma. In addition, a series of simulations are presented that explore the charge and current neutralization of the ion beam in an evacuated chamber. For this vacuum transport mode, neutralizing electrons are only drawn from sources near the chamber entrance

  10. Plasmapheresis and other extracorporeal filtration techniques in critical patients.

    Science.gov (United States)

    Daga Ruiz, D; Fonseca San Miguel, F; González de Molina, F J; Úbeda-Iglesias, A; Navas Pérez, A; Jannone Forés, R

    2017-04-01

    Plasmapheresis is an extracorporeal technique that eliminates macromolecules involved in pathological processes from plasma. A review is made of the technical aspects, main indications in critical care and potential complications of plasmapheresis, as well as of other extracorporeal filtration techniques such as endotoxin-removal columns and other devices designed to eliminate cytokines or modulate the inflammatory immune response in critical patients. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  11. [Smog chamber simulation of ozone formation from atmospheric photooxidation of propane].

    Science.gov (United States)

    Huang, Li-hua; Mo, Chuang-rong; Xu, Yong-fu; Jia, Long

    2012-08-01

    Atmospheric photochemical reactions of propane and NO, were simulated with a self-made smog chamber. The effects of relative humidity (RH) and [C3H8]0/[NOx]0 ratio on ozone formation were studied. The results showed that both the maximum ozone concentration and the maximum value of incremental reactivity (IRmax) of propane decreased linearly with increasing RH. Under lower RH conditions, the occurrence time of peak ozone concentration was about 22 h after the beginning of reaction, and IRmax varied from 0.0231 to 0.0391, while under higher RH conditions the occurrence time of peak ozone concentration was 16 h, and IRmax ranged from 0.0172 to 0.0320. During the 20 h of reaction, within the first 12 h RH did not significantly affect the yield of acetone, whereas after 12 h the lower RH condition could lead to relatively greater amount of acetone. During the first 4-20 h of experiments, acetone concentrations ranged from 153 x 10(-9) to 364 x 10(-9) at 17% RH and from 167 x 10(-9) to 302 x 10(-9) at 62% RH, respectively. Maximum ozone concentrations decreased with increasing [C3H8]0/[NOx]0 ratio and a better negative linear relationship between them was obtained under the lower RH conditions. The smog chamber data and the results from simulation of the C3H8-NOx reactions using the sub-mechanism of MCM were compared, and a significant deviation was found between these two results.

  12. Development of an Extracorporeal Perfusion Device for Small Animal Free Flaps.

    Directory of Open Access Journals (Sweden)

    Andreas M Fichter

    Full Text Available Extracorporeal perfusion (ECP might prolong the vital storage capabilities of composite free flaps, potentially opening a wide range of clinical applications. Aim of the study was the development a validated low-cost extracorporeal perfusion model for further research in small animal free flaps.After establishing optimal perfusion settings, a specially designed extracorporeal perfusion system was evaluated during 8-hour perfusion of rat epigastric flaps followed by microvascular free flap transfer. Controls comprised sham-operation, ischemia and in vivo perfusion. Flaps and perfusate (diluted blood were closely monitored by blood gas analysis, combined laser Doppler flowmetry and remission spectroscopy and Indocyanine-Green angiography. Evaluations were complemented by assessment of necrotic area and light microscopy at day 7.ECP was established and maintained for 8 hours with constant potassium and pH levels. Subsequent flap transfer was successful. Notably, the rate of necrosis of extracorporeally perfused flaps (27% was even lower than after in vivo perfusion (49%, although not statistically significant (P = 0,083. After sham-operation, only 6% of the total flap area became necrotic, while 8-hour ischemia led to total flap loss (98%. Angiographic and histological findings confirmed these observations.Vital storage capabilities of microvascular flaps can be prolonged by temporary ECP. Our study provides important insights on the pathophysiological processes during extracorporeal tissue perfusion and provides a validated small animal perfusion model for further studies.

  13. Multispecimen dual-beam irradiation damage chamber

    International Nuclear Information System (INIS)

    Packan, N.H.; Buhl, R.A.

    1980-06-01

    An irradiation damage chamber that can be used to rapidly simulate fast neutron damage in fission or fusion materials has been designed and constructed. The chamber operates in conjunction with dual Van de Graaff accelerators at ORNL to simulate a wide range of irradiation conditions, including pulsed irradiation. Up to six experiments, each with up to nine 3-mm disk specimens, can be loaded into the ultrahigh vacuum chamber. Specimen holders are heated with individual electron guns, and the temperature of each specimen can be monitored during bombardment by an infrared pyrometer. Three different dose levels may be obtained during any single bombardment, and the heavy-ion flux on each of the nine specimens can be measured independently with only a brief interruption of the beam. The chamber has been in service for nearly three years, during which time approximately 250 bombardments have been successfully carried out. An appendix contains detailed procedures for operating the chamber

  14. Extracorporeal Circulation Using an Extracorporeal Membrane Oxygenation System and an Autotransfusion System

    Directory of Open Access Journals (Sweden)

    Yu. A. Bakhareva

    2010-01-01

    Full Text Available The authors draw attention to the fact that complete cardiopulmonary bypass can be made in the emergency situation in order to perform an extracorporeal membrane oxygenation (ECMO procedure in a 5-year-old boy weighing 15 kg, diagnosed as having Fallot tetrad. By taking into account the technological features of the system for ECMO, there is an additional need for a blood cell separator to be applied.

  15. Accurate computer simulation of a drift chamber

    International Nuclear Information System (INIS)

    Killian, T.J.

    1980-01-01

    A general purpose program for drift chamber studies is described. First the capacitance matrix is calculated using a Green's function technique. The matrix is used in a linear-least-squares fit to choose optimal operating voltages. Next the electric field is computed, and given knowledge of gas parameters and magnetic field environment, a family of electron trajectories is determined. These are finally used to make drift distance vs time curves which may be used directly by a track reconstruction program. Results are compared with data obtained from the cylindrical chamber in the Axial Field Magnet experiment at the CERN ISR

  16. Extracorporeal shockwave therapy: A systematic review of its use in fracture management

    Directory of Open Access Journals (Sweden)

    Petrisor B

    2009-01-01

    Full Text Available Extracorporeal shockwave therapy is increasingly used as an adjuvant therapy in the management of nonunions, delayed unions and more recently fresh fractures. This is in an effort to increase union rates or obtain unions when fractures have proven recalcitrant to healing. In this report we have systematically reviewed the English language literature to attempt to determine the potential clinical efficacy of extracorporeal shockwave therapy in fracture management. Of 32 potentially eligible studies identified, 10 were included that assessed the extracorporeal shockwave therapy use for healing nonunions or delayed unions, and one trial was included that assessed its use for acute high-energy fractures. From the included, studies′ overall union rates were in favor of extracorporeal shockwave therapy (72% union rate overall for nonunions or delayed unions, and a 46% relative risk reduction in nonunions when it is used for acute high-energy fractures. However, the methodologic quality of included studies was weak and any clinical inferences made from these data should be interpreted with caution. Further research in this area in the form of a large-scale randomized trial is necessary to better answer the question of the effectiveness of extracorporeal shockwave therapy on union rates for both nonunions and acute fractures.

  17. Temperature Studies for ATLAS MDT BOS Chambers

    CERN Document Server

    Engl, A.; Biebel, O.; Mameghani, R.; Merkl, D.; Rauscher, F.; Schaile, D.; Ströhmer, R.

    Data sets with high statistics taken at the cosmic ray facility, equipped with 3 ATLAS BOS MDT chambers, in Garching (Munich) have been used to study temperature and pressure effects on gas gain and drifttime. The deformation of a thermally expanded chamber was reconstructed using the internal RasNik alignment monitoring system and the tracks from cosmic data. For these studies a heating system was designed to increase the temperature of the middle chamber by up to 20 Kelvins over room temperature. For comparison the temperature effects on gas properties have been simulated with Garfield. The maximum drifttime decreased under temperature raise by -2.21 +- 0.08 ns/K, in agreement with the results of pressure variations and the Garfield simulation. The increased temperatures led to a linear increase of the gas gain of about 2.1% 1/K. The chamber deformation has been analyzed with the help of reconstructed tracks. By the comparison of the tracks through the reference chambers with these through the test chamber ...

  18. Extracorporeal shock wave therapy for treatment of plantar fasciitis

    International Nuclear Information System (INIS)

    Dastgir, N.

    2014-01-01

    Objective: To explore the effect of extracorporeal shock wave therapy in patients with chronic plantar faciitis. Methods: The prospective study was conducted at Department of Orhopaedic, Regional Hospital, Limerick, Ireland from January to December 2004 and comprised 70 heels in 62 patients with chronic plantar fasciitis in whom conventional conservative treatment consisting of non-steroidal anti-inflammatory drugs, heel cup, orthoses and/or shoe modifications, local steroid injections had failed, and they were treated with low energy extracorporeal shock wave therapy. Patients were reviewed at 6, 12 and 24 weeks post treatment. Results: At follow-up there was significant decrease in pain on the visual analogue scale (p<0.027), with significant improvement in pain score (p<0.009) and in functional score (p<0.001). The comfortable walking distance had increased significantly and there were no reported side effects. Conclusion: Extracorporeal shock wave therapy is a new modality providing good pain relief and a satisfactory clinical outcome in patients with chronic plantar fasciitis. (author)

  19. Design of a new multi-phase experimental simulation chamber for atmospheric photosmog, aerosol and cloud chemistry research

    Directory of Open Access Journals (Sweden)

    J. Wang

    2011-11-01

    Full Text Available A new simulation chamber has been built at the Interuniversitary Laboratory of Atmospheric Systems (LISA. The CESAM chamber (French acronym for Experimental Multiphasic Atmospheric Simulation Chamber is designed to allow research in multiphase atmospheric (photo- chemistry which involves both gas phase and condensed phase processes including aerosol and cloud chemistry. CESAM has the potential to carry out variable temperature and pressure experiments under a very realistic artificial solar irradiation. It consists of a 4.2 m3 stainless steel vessel equipped with three high pressure xenon arc lamps which provides a controlled and steady environment. Initial characterization results, all carried out at 290–297 K under dry conditions, concerning lighting homogeneity, mixing efficiency, ozone lifetime, radical sources, NOy wall reactivity, particle loss rates, background PM, aerosol formation and cloud generation are given. Photolysis frequencies of NO2 and O3 related to chamber radiation system were found equal to (4.2 × 10−3 s−1 for JNO2 and (1.4 × 10−5 s−1 for JO1D which is comparable to the solar radiation in the boundary layer. An auxiliary mechanism describing NOy wall reactions has been developed. Its inclusion in the Master Chemical Mechanism allowed us to adequately model the results of experiments on the photo-oxidation of propene-NOx-Air mixtures. Aerosol yields for the α-pinene + O3 system chosen as a reference were determined and found in good agreement with previous studies. Particle lifetime in the chamber ranges from 10 h to 4 days depending on particle size distribution which indicates that the chamber can provide high quality data on aerosol aging processes and their effects. Being evacuable, it is possible to generate in this new chamber

  20. EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY AS ...

    African Journals Online (AJOL)

    Objective To evaluate extracorporeal shock wave lithotripsy (ESWL) as a monotherapy for urolithiasis in patients with solitary kidney and to determine the factors that may affect its results. Patients and Methods Using the Dornier MFL 5000 lithotriptor, 106 patients with solitary kidney (80 men and 26 women) were treated for ...

  1. Significant social events and increasing use of life-sustaining treatment: trend analysis using extracorporeal membrane oxygenation as an example.

    Science.gov (United States)

    Chen, Yen-Yuan; Chen, Likwang; Huang, Tien-Shang; Ko, Wen-Je; Chu, Tzong-Shinn; Ni, Yen-Hsuan; Chang, Shan-Chwen

    2014-03-04

    Most studies have examined the outcomes of patients supported by extracorporeal membrane oxygenation as a life-sustaining treatment. It is unclear whether significant social events are associated with the use of life-sustaining treatment. This study aimed to compare the trend of extracorporeal membrane oxygenation use in Taiwan with that in the world, and to examine the influence of significant social events on the trend of extracorporeal membrane oxygenation use in Taiwan. Taiwan's extracorporeal membrane oxygenation uses from 2000 to 2009 were collected from National Health Insurance Research Dataset. The number of the worldwide extracorporeal membrane oxygenation cases was mainly estimated using Extracorporeal Life Support Registry Report International Summary July 2012. The trend of Taiwan's crude annual incidence rate of extracorporeal membrane oxygenation use was compared with that of the rest of the world. Each trend of extracorporeal membrane oxygenation use was examined using joinpoint regression. The measurement was the crude annual incidence rate of extracorporeal membrane oxygenation use. Each of the Taiwan's crude annual incidence rates was much higher than the worldwide one in the same year. Both the trends of Taiwan's and worldwide crude annual incidence rates have significantly increased since 2000. Joinpoint regression selected the model of the Taiwan's trend with one joinpoint in 2006 as the best-fitted model, implying that the significant social events in 2006 were significantly associated with the trend change of extracorporeal membrane oxygenation use following 2006. In addition, significantly social events highlighted by the media are more likely to be associated with the increase of extracorporeal membrane oxygenation use than being fully covered by National Health Insurance. Significant social events, such as a well-known person's successful extracorporeal membrane oxygenation use highlighted by the mass media, are associated with the use of

  2. Experience and needs of family members of patients treated with extracorporeal membrane oxygenation.

    Science.gov (United States)

    Tramm, Ralph; Ilic, Dragan; Murphy, Kerry; Sheldrake, Jayne; Pellegrino, Vincent; Hodgson, Carol

    2017-06-01

    To explore the experiences of family members of patients treated with extracorporeal membrane oxygenation. Sudden onset of an unexpected and severe illness is associated with an increased stress experience of family members. Only one study to date has explored the experience of family members of patients who are at high risk of dying and treated with extracorporeal membrane oxygenation. A qualitative descriptive research design was used. A total of 10 family members of patients treated with extracorporeal membrane oxygenation were recruited through a convenient sampling approach. Data were collected using open-ended semi-structured interviews. A six-step process was applied to analyse the data thematically. Four criteria were employed to evaluate methodological rigour. Family members of extracorporeal membrane oxygenation patients experienced psychological distress and strain during and after admission. Five main themes (Going Downhill, Intensive Care Unit Stress and Stressors, Carousel of Roles, Today and Advice) were identified. These themes were explored from the four roles of the Carousel of Roles theme (decision-maker, carer, manager and recorder) that participants experienced. Nurses and other staff involved in the care of extracorporeal membrane oxygenation patients must pay attention to individual needs of the family and activate all available support systems to help them cope with stress and strain. An information and recommendation guide for families and staff caring for extracorporeal membrane oxygenation patients was developed and needs to be applied cautiously to the individual clinical setting. © 2016 John Wiley & Sons Ltd.

  3. Proceedings of workshop on streamer chamber

    International Nuclear Information System (INIS)

    Itoh, Hidihiko; Takahashi, Kaoru; Hirose, Tachishige; Masaike, Akira

    1978-08-01

    For high accuracy observation of multiple-body reactions, a vertex detector of high efficiency is essential. A bubble chamber, though excellent for tracks detection, is problematic in statistics accuracy. The vertex detector with a wire chamber, while better in this respect, difficult in multiple-particle detection etc. The workshop has had several meetings on a streamer chamber as a detector combining features of both bubble chamber and counter, with emphasis on tracks observation in avalanche mode and recordings not using films. Contents are on streamer chamber gas, analytical photography, data processing, simulation program, etc. (Mori, K.)

  4. Accurate computer simulation of a drift chamber

    CERN Document Server

    Killian, T J

    1980-01-01

    The author describes a general purpose program for drift chamber studies. First the capacitance matrix is calculated using a Green's function technique. The matrix is used in a linear-least-squares fit to choose optimal operating voltages. Next the electric field is computed, and given knowledge of gas parameters and magnetic field environment, a family of electron trajectories is determined. These are finally used to make drift distance vs time curves which may be used directly by a track reconstruction program. The results are compared with data obtained from the cylindrical chamber in the Axial Field Magnet experiment at the CERN ISR. (1 refs).

  5. Optimal time for initiating extracorporeal membrane oxygenation.

    Science.gov (United States)

    Haile, Dawit T; Schears, Gregory J

    2009-09-01

    The technical evolution of extracorporeal membrane oxygenation (ECMO) coincides with the vast improvement in intensive care medicine of the past 4 decades. Extracorporeal circulatory technology substitutes for acutely failed cardiac or pulmonary function until these organs regain sustainable function through goal-oriented intensive care practice. The technology has been validated to improve survival in select patients who would otherwise have 100% mortality. This is by far the most complex life-sustaining technology employed and thus can contribute significant risks such that the decision to institute ECMO requires prompt risk and benefit analysis. Delaying the institution of ECMO may cause irreversible pulmonary and cardiac injuries in addition to other organs. Therefore, the optimal time of initiating ECMO support is crucial to the survival of a critically ill patient.

  6. Extracorporeal life support in pediatric cardiac patients

    Directory of Open Access Journals (Sweden)

    Matteo Di NARDO

    2016-10-01

    Full Text Available Extracorporeal Life Support (ECLS is a valuable tool in the management of neonates and older children with severe cardiac or respiratory failure. In this review, we focus on ECLS when used for neonatal and pediatric cardiac disease. Strict selection of patients and timely deployment are necessary to optimize outcomes. Although every attempt should be made to deploy ECLS urgently rather than emergently, extracorporeal cardiopulmonary resuscitation (ECPR is being increasingly used and reasonable survival rates have been achieved after initiation of ECLS during active compressions of the chest following in-hospital cardiac arrest. Contraindications to ECLS are falling over time, although lethal chromosomal abnormalities, severe irreversible brain injury, and extremely low gestational age and weight (<32 weeks gestation or <1.5 kg remain firm contraindications.

  7. Adjunctive Therapies During Extracorporeal Membrane Oxygenation to Enhance Multiple Organ Support in Critically Ill Children

    Directory of Open Access Journals (Sweden)

    Marguerite Orsi Canter

    2018-04-01

    Full Text Available Since the advent of extracorporeal membrane oxygenation (ECMO over 40 years ago, there has been increasing interest in the use of the extracorporeal circuit as a platform for providing multiple organ support. In this review, we will examine the evidence for the use of continuous renal replacement therapy, therapeutic plasma exchange, leukopheresis, adsorptive therapies, and extracorporeal liver support in conjunction with ECMO.

  8. Extracorporeal membrane oxygenation: experience in an adult medical ICU.

    Science.gov (United States)

    Hermans, G; Meersseman, W; Wilmer, A; Meyns, B; Bobbaers, H

    2007-06-01

    Extracorporeal membrane oxygenation (ECMO) is a technology that can provide extracorporeal gas exchange to patients with severe pulmonary or cardiac dysfunction. We report on our clinical experience with ECMO in critically ill patients. We performed a retrospective analysis of 23 patients treated with ECMO in a medical intensive care unit in a tertiary referral academic centre. 13 patients were considered immunocompetent and 10 were immunocompromised when extracorporeal membrane oxygenation was started. 16 patients presented with acute respiratory distress syndrome (ARDS), 2 patients had intractable cardiac failure, and 5 patients had combined respiratory and cardiac failure. In 16 patients, a veno-venous bypass was constructed; in 7 patients, the initial bypass was venoarterial. 11 patients survived. In 2 patients technical complications were fatal. Our data indicate that patients with community-acquired pneumonia and no underlying disease will benefit most from this technique. However, long-term survival is possible in immunocompromised patients. Venoarterial bypass can carry a higher risk for technical complications. Increasing experience apparently also reduces the risk of technical complications.

  9. Superconducting-Magnet-Based Faraday Rotation Spectrometer for Real Time in Situ Measurement of OH Radicals at 106 Molecule/cm3 Level in an Atmospheric Simulation Chamber.

    Science.gov (United States)

    Zhao, Weixiong; Fang, Bo; Lin, Xiaoxiao; Gai, Yanbo; Zhang, Weijun; Chen, Wenge; Chen, Zhiyou; Zhang, Haifeng; Chen, Weidong

    2018-03-20

    Atmospheric simulation chambers play vital roles in the validation of chemical mechanisms and act as a bridge between field measurements and modeling. Chambers operating at atmospheric levels of OH radicals (10 6 -10 7 molecule/cm 3 ) can significantly enhance the possibility for investigating the discrepancies between the observation and model predications. However, few chambers can directly detect chamber OH radicals at ambient levels. In this paper, we report on the first combination of a superconducting magnet with midinfrared Faraday rotation spectroscopy (FRS) for real time in situ measurement of the OH concentration in an atmospheric simulation chamber. With the use of a multipass enhanced FRS, a detection limit of 3.2 × 10 6 OH/cm 3 (2σ, 4 s) was achieved with an absorption path length of 108 m. The developed FRS system provided a unique, self-calibrated analytical instrument for in situ direct measurement of chamber OH concentration.

  10. Tracking with wire chambers at high luminosities

    International Nuclear Information System (INIS)

    Hanson, G.G.

    1989-12-01

    Radiation damage and rate limitations impose severe constraints on wire chambers at the SSC. Possible conceptual designs for wire chamber tracking systems that satisfy these constraints are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 11 refs., 10 figs

  11. Outcome of Extracorporeal Shock Wave Lithotripsy

    Directory of Open Access Journals (Sweden)

    B Shrestha

    2010-03-01

    Full Text Available NTRODUCTION: Extracorporeal Shock Wave Lithotripsy is an effective noninvasive method to treat urolithiasis. This study aims to evaluate itsoutcome and determine appropriate management strategies for urolithiasis. METHODS: It was a prospective study which included one hundred patients who underwent ESWL for the management of solitary urolithiasis during a period of eight months (December 2007-August 2008. Status of stone and complications were observed and managed accordingly within a period of six postoperative weeks. RESULTS: Out of 100 patients, 93% had complete clearance of stone by the end of six postoperative weeks. Seven percent of the patients required adjunct invasive intervention including open surgery in 3%. Number of sessions of ESWL was found to increase as the size of stone increased. However, in three patients stones were completely refractory to ESWL even after two consecutive sessions. CONCLUSIONS: ESWL is highly effective noninvasive modality in the management of urolithiasis in appropriately selected patients. Keywords: double J stent, extracorporal shockwave lithotripsy, steinstrasse, ultrasonography, ureterorenoscopy.

  12. Numerical simulation of performance of heavy ion inertial confinement fusion target with ellipsoidal chamber

    International Nuclear Information System (INIS)

    Basin, A.A.; Vatulin, V.V.; Vakhlamova, L.L.; Vinokurov, P.A.; Dement'ev, Yu.A.; Eliseev, G.M.; Ermolovich, V.F.; Morenko, L.Z.; Morenko, A.I.; Remizov, G.N.; Romanov, Yu.A.; Ryabikina, N.A.; Skrypnik, S.I.; Skidan, G.I.; Tikhomirov, B.P.; Shagaliev, R.M.

    1996-01-01

    To solve the design problem of an inertial thermonuclear fusion facility requires the united efforts of scientists in various countries. In the field of heavy ion fusion a collaboration between scientists in Germany and Russia is under successful development. VNIIEF possesses advanced software for numerical simulation of the processes in thermonuclear target operation. This paper describes a target design suggested and being studied by scientists of Frankfurt University and GSI which is based on 2D non-stationary calculation of the X-ray energy transport and capsule compression. The target consists of a spherical capsule with DT fuel and an ellipsoidal chamber containment. The ion beam energy is released in two fixed converters located on the chamber axis symmetricall with respect to the capsule. The X-ray field is formed on the capsule surface with a set of special shields. The basic aim of our research is to estimate the effect of gas dynamic expansion of the chamber walls, shields and capsule on the target operation. To increase the reliability of the obtained results and the assessment of probable errors in predicting radiation field parameters and the capsule state, the calculations were accomplished in a kinetic arrangement with various techniques. (orig.)

  13. Blood leukocyte responses to extracorporeal circulation. 1. Short term extracorporeal circulation in dogs without and with extracorporeal irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Szemere, P.; Fliedner, T.M. (Ulm Univ. (Germany, F.R.). Abt. Klinische Physiologie)

    1983-01-01

    Short term (1 h) extracorporeal circulation without or with irradiation of blood was performed in two normal dogs in a series of experiments. The granulocyte count was constantly diminished, while the lymphocytes did not show any particular change in their concentration. In the majority of the experiments a decrease of the CFU-C content occurred to less than 70% of the initial level. There was no difference in the results of experiments with or without irradiation. In the 'bag to bag' procedures, no significant change in the blood leukocyte counts including CFU-C, was established.

  14. Simulation study of the photon quality correction factors of ionization chambers for FiR 1 epithermal neutron beam

    International Nuclear Information System (INIS)

    Koivunoro, H.; Uusi-Simola, J.; Savolainen, S.; Kotiluoto, P.; Auterinen, I.; Kosunen, A.

    2006-01-01

    At FiR 1 BNCT facility in Finland, neutron-insensitive Mg(Ar) ionization chambers are used for photon dose measurements in an epithermal neutron beam. Previously, photon sensitivity factors for the chamber for the measurements in a water phantom in FiR 1 beam have been determined experimentally from measurements in 60 Co gamma and in a 6 MV clinical accelerator photon beams. However, the response of the ionization chamber in a water phantom depends on energy spectrum and angle of the photons and the secondary electrons created inside the phantom and may differ depending on type of the irradiation source (accelerator vs. an epithermal neutron beam). Also, the experimental sensitivity factor does not take into account the possible perturbations in the photon production in phantom caused by the ionization chamber materials. Therefore, it is necessary to determine the photon quality correction factors (k Qγ ) for the Mg(Ar) chamber at the FiR 1 beam through computer simulations. In this study, the k Qγ factors have been determined for Mg(Ar) chamber from Monte Carlo calculations of absorbed photon dose at two depths in a water phantom using MCNP code. The k qγ factors obtained with this method are compared to the sensitivity factors determined with measurements in an accelerator photon beam and to the k Qγ factors published previously. (author)

  15. Note: The design of thin gap chamber simulation signal source based on field programmable gate array

    International Nuclear Information System (INIS)

    Hu, Kun; Wang, Xu; Li, Feng; Jin, Ge; Lu, Houbing; Liang, Futian

    2015-01-01

    The Thin Gap Chamber (TGC) is an important part of ATLAS detector and LHC accelerator. Targeting the feature of the output signal of TGC detector, we have designed a simulation signal source. The core of the design is based on field programmable gate array, randomly outputting 256-channel simulation signals. The signal is generated by true random number generator. The source of randomness originates from the timing jitter in ring oscillators. The experimental results show that the random number is uniform in histogram, and the whole system has high reliability

  16. The EXTRIP (EXtracorporeal TReatments In Poisoning) workgroup

    DEFF Research Database (Denmark)

    Lavergne, Valéry; Nolin, Thomas D; Hoffman, Robert S

    2012-01-01

    Extracorporeal treatments (ECTRs), such as hemodialysis and hemoperfusion, are used in poisoning despite a lack of controlled human trials demonstrating efficacy. To provide uniform recommendations, the EXTRIP group was formed as an international collaboration among recognized experts from...

  17. Mechanical ventilation management during extracorporeal membrane oxygenation for acute respiratory distress syndrome: a retrospective international multicenter study.

    Science.gov (United States)

    Schmidt, Matthieu; Stewart, Claire; Bailey, Michael; Nieszkowska, Ania; Kelly, Joshua; Murphy, Lorna; Pilcher, David; Cooper, D James; Scheinkestel, Carlos; Pellegrino, Vincent; Forrest, Paul; Combes, Alain; Hodgson, Carol

    2015-03-01

    To describe mechanical ventilation settings in adult patients treated for an acute respiratory distress syndrome with extracorporeal membrane oxygenation and assess the potential impact of mechanical ventilation settings on ICU mortality. Retrospective observational study. Three international high-volume extracorporeal membrane oxygenation centers. A total of 168 patients treated with extracorporeal membrane oxygenation for severe acute respiratory distress syndrome from January 2007 to January 2013. We analyzed the association between mechanical ventilation settings (i.e. plateau pressure, tidal volume, and positive end-expiratory pressure) on ICU mortality using multivariable logistic regression model and Cox-proportional hazards model. We obtained detailed demographic, clinical, daily mechanical ventilation settings and ICU outcome data. One hundred sixty-eight patients (41 ± 14 years old; PaO2/FIO2 67 ± 19 mm Hg) fulfilled our inclusion criteria. Median duration of extracorporeal membrane oxygenation and ICU stay were 10 days (6-18 d) and 28 days (16-42 d), respectively. Lower positive end-expiratory pressure levels and significantly lower plateau pressures during extracorporeal membrane oxygenation were used in the French center than in both Australian centers (23.9 ± 1.4 vs 27.6 ± 3.7 and 27.8 ± 3.6; p Protective mechanical ventilation strategies were routinely used in high-volume extracorporeal membrane oxygenation centers. However, higher positive end-expiratory pressure levels during the first 3 days on extracorporeal membrane oxygenation support were independently associated with improved survival. Further prospective trials on the optimal mechanical ventilation strategy during extracorporeal membrane oxygenation support are warranted.

  18. Tracking with wire chambers at the SSC

    International Nuclear Information System (INIS)

    Hanson, G.G.; Gundy, M.C.; Palounek, A.P.T.

    1989-07-01

    Limitations placed on wire chambers by radiation damage and rate requirements in the SSC environment are reviewed. Possible conceptual designs for wire chamber tacking systems that meet these requirements are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 13 refs., 11 fig., 1 tab

  19. LEUKOCYTE AND PLATELET ACTIVATION DURING EXTRACORPOREAL-CIRCULATION

    NARCIS (Netherlands)

    VANOEVEREN, W

    1994-01-01

    Extracorporeal circulation of blood has become a routine procedure in plasmapheresis, hemodialysis and cardiopulmonary bypass. Specifically in cardiopulmonary bypass, blood is exposed to a large material surface area, which induces an inflammatory reaction and bleeding disorders. It has been

  20. Performance investigation of the pulse and Campbelling modes of a fission chamber using a Poisson pulse train simulation code

    Energy Technology Data Exchange (ETDEWEB)

    Elter, Zs. [CEA, DEN, DER, Instrumentation, Sensors and Dosimetry Laboratory, Cadarache, F-13108 Saint-Paul-lez-Durance (France); Chalmers University of Technology, Department of Applied Physics, Division of Nuclear Engineering, SE-412 96 Göteborg (Sweden); Jammes, C., E-mail: christian.jammes@cea.fr [CEA, DEN, DER, Instrumentation, Sensors and Dosimetry Laboratory, Cadarache, F-13108 Saint-Paul-lez-Durance (France); Pázsit, I. [Chalmers University of Technology, Department of Applied Physics, Division of Nuclear Engineering, SE-412 96 Göteborg (Sweden); Pál, L. [Centre for Energy Research, Hungarian Academy of Sciences, H-1525 Budapest 114, POB 49 (Hungary); Filliatre, P. [CEA, DEN, DER, Instrumentation, Sensors and Dosimetry Laboratory, Cadarache, F-13108 Saint-Paul-lez-Durance (France)

    2015-02-21

    The detectors of the neutron flux monitoring system of the foreseen French GEN-IV sodium-cooled fast reactor (SFR) will be high temperature fission chambers placed in the reactor vessel in the vicinity of the core. The operation of a fission chamber over a wide-range neutron flux will be feasible provided that the overlap of the applicability of its pulse and Campbelling operational modes is ensured. This paper addresses the question of the linearity of these two modes and it also presents our recent efforts to develop a specific code for the simulation of fission chamber pulse trains. Our developed simulation code is described and its overall verification is shown. An extensive quantitative investigation was performed to explore the applicability limits of these two standard modes. It was found that for short pulses the overlap between the pulse and Campbelling modes can be guaranteed if the standard deviation of the background noise is not higher than 5% of the pulse amplitude. It was also shown that the Campbelling mode is sensitive to parasitic noise, while the performance of the pulse mode is affected by the stochastic amplitude distributions.

  1. Neonatal and pediatric extracorporeal membrane oxygenation in developing Latin American countries

    Directory of Open Access Journals (Sweden)

    Javier Kattan

    2017-03-01

    Conclusions: The best results in short‐ and long‐term survival are in patients with isolated respiratory diseases. Today extracorporeal membrane oxygenation therapy is a standard therapy in some Latin American referral centers. It is hoped that these new extracorporeal membrane oxygenation centers will have a positive impact on the survival of newborns and children with respiratory or cardiac failure, and that they will be available for an increasing number of patients from this region in the near future.

  2. Extracorporeal Membrane Oxygenation for End-Stage Interstitial Lung Disease With Secondary Pulmonary Hypertension at Rest and Exercise: Insights From Simulation Modeling.

    Science.gov (United States)

    Chicotka, Scott; Burkhoff, Daniel; Dickstein, Marc L; Bacchetta, Matthew

    Interstitial lung disease (ILD) represents a collection of lung disorders with a lethal trajectory with few therapeutic options with the exception of lung transplantation. Various extracorporeal membrane oxygenation (ECMO) configurations have been used for bridge to transplant (BTT), yet no optimal configuration has been clearly demonstrated. Using a cardiopulmonary simulation, we assessed different ECMO configurations for patients with end-stage ILD to assess the physiologic deficits and help guide the development of new long-term pulmonary support devices. A cardiopulmonary ECMO simulation was created, and changes in hemodynamics and blood gases were compared for different inflow and outflow anatomic locations and for different sweep gas and blood pump flow rates. The system simulated the physiologic response of patients with severe ILD at rest and during exercise with central ECMO, peripheral ECMO, and with no ECMO. The output parameters were total cardiac output (CO), mixed venous oxygen (O2) saturation, arterial pH, and O2 delivery (DO2)/O2 utilization (VO2) at different levels of exercise. The model described the physiologic state of progressive ILD and showed the relative effects of using various ECMO configurations to support them. It elucidated the optimal device configurations and required physiologic pump performance and provided insight into the physiologic demands of exercise in ILD patients. The simulation program was able to model the pathophysiologic state of progressive ILD with PH and demonstrate how mechanical support devices can be implemented to improve cardiopulmonary function at rest and during exercise. The information generated from simulation can be used to optimize ECMO configuration selection for BTT patients and provide design guidance for new devices to better meet the physiologic demands of exercise associated with normal activities of daily living.

  3. Simulation and measurements of the response of an air ionisation chamber exposed to a mixed high-energy radiation field

    International Nuclear Information System (INIS)

    Vincke, H.; Forkel-Wirth, D.; Perrin, D.; Theis, C.

    2005-01-01

    CERN's radiation protection group operates a network of simple and robust ionisation chambers that are installed inside CERN's accelerator tunnels. These ionisation chambers are used for the remote reading of ambient dose rate equivalents inside the machines during beam-off periods. This Radiation Protection Monitor for dose rates due to Induced Radioactivity ('PMI', trade name: PTW, Type 34031) is a non-confined air ionisation plastic chamber which is operated under atmospheric pressure. Besides its current field of operation it is planned to extend the use of this detector in the Large Hadron Collider to measure radiation under beam operation conditions to obtain an indication of the machine performance. Until now, studies of the PMI detector have been limited to the response to photons. In order to evaluate its response to other radiation components, this chamber type was tested at CERF, the high-energy reference field facility at CERN. Six PMI detectors were installed around a copper target being irradiated by a mixed hadron beam with a momentum of 120 GeV c -1 . Each of the chosen detector positions was defined by a different radiation field, varying in type and energy of the incident particles. For all positions, detailed measurements and FLUKA simulations of the detector response were performed. This paper presents the promising comparison between the measurements and simulations and analyses the influence of the different particle types on the resulting detector response. (authors)

  4. Swirling Combustor Energy Converter: H2/Air Simulations of Separated Chambers

    Directory of Open Access Journals (Sweden)

    Angelo Minotti

    2015-09-01

    Full Text Available This work reports results related to the “EU-FP7-HRC-Power” project aiming at developing micro-meso hybrid sources of power. One of the goals of the project is to achieve surface temperatures up to more than 1000 K, with a ∆T ≤ 100 K, in order to be compatible with a thermal/electrical conversion by thermo-photovoltaic cells. The authors investigate how to reach that goal adopting swirling chambers integrated in a thermally-conductive and emitting element. The converter consists of a small parallelepiped brick inside two separated swirling meso-combustion chambers, which heat up the parallelepiped, emitting material by the combustion of H2 and air at ambient pressure. The overall dimension is of the order of cm. Nine combustion simulations have been carried out assuming detailed chemistry, several length/diameter ratios (Z/D = 3, 5 and 11 and equivalence ratios (0.4, 0.7 and 1; all are at 400 W of injected chemical power. Among the most important results are the converter surfaces temperatures, the heat loads, provided to the environment, and the chemical efficiency. The high chemical efficiency, h > 99.9%, is due to the relatively long average gas residence time coupled with the fairly good mixing due to the swirl motion and the impinging air/fuel jets that provide heat and radicals to the flame.

  5. The Design of Temperature and Humidity Chamber Monitor and Controller

    OpenAIRE

    Tibebu, Simachew

    2016-01-01

    The temperature and humidity chamber, (climate chamber) is a device located at the Technobothnia Education and Research Center that simulates different climate conditions. The simulated environment is used to test the capabilities of electrical equipment in different temperature and humidity conditions. The climate chamber, among other things houses a dedicated computer, the control PC, and a control software running in it which together are responsible for running and control-ling these simu...

  6. Advances on fission chamber modelling

    International Nuclear Information System (INIS)

    Filliatre, Philippe; Jammes, Christian; Geslot, Benoit; Veenhof, Rob

    2013-06-01

    In-vessel, online neutron flux measurements are routinely performed in mock-up and material testing reactors by fission chambers. Those measurements have a wide range of applications, including characterization of experimental conditions, reactor monitoring and safety. Depending on the application, detectors may experience a wide range of constraints, of several magnitudes, in term of neutron flux, gamma-ray flux, temperature. Hence, designing a specific fission chamber and measuring chain for a given application is a demanding task. It can be achieved by a combination of experimental feedback and simulating tools, the latter being based on a comprehensive understanding of the underlying physics. A computation route that simulates fission chambers, named CHESTER, is presented. The retrieved quantities of interest are the neutron-induced charge spectrum, the electronic and ionic pulses, the mean current and variance, the power spectrum. It relies on the GARFIELD suite, originally developed for drift chambers, and makes use of the MAGBOLTZ code to assess the drift parameters of electrons within the filling gas, and the SRIM code to evaluate the stopping range of fission products. The effect of the gamma flux is also estimated. Computations made with several fission chambers exemplify the possibilities of the route. A good qualitative agreement is obtained when comparing the results with the experimental data available to date. In a near future, a comprehensive experimental programme will be undertaken to qualify the route using the known neutron sources, mock-up reactors and wide choice of fission chambers, with a stress on the predictiveness of the Campbelling mode. Depending on the results, a refinement of the modelling and an effort on the accuracy of input data are also to be considered. CHESTER will then make it possible to predict the overall sensitivity of a chamber, and to optimize the design for a given application. Another benefit will be to increase the

  7. Extracorporeal Treatment in Phenytoin Poisoning: Systematic Review and Recommendations from the EXTRIP (Extracorporeal Treatments in Poisoning) Workgroup.

    Science.gov (United States)

    Anseeuw, Kurt; Mowry, James B; Burdmann, Emmanuel A; Ghannoum, Marc; Hoffman, Robert S; Gosselin, Sophie; Lavergne, Valery; Nolin, Thomas D

    2016-02-01

    The Extracorporeal Treatments in Poisoning (EXTRIP) Workgroup conducted a systematic literature review using a standardized process to develop evidence-based recommendations on the use of extracorporeal treatment (ECTR) in patients with phenytoin poisoning. The authors reviewed all articles, extracted data, summarized findings, and proposed structured voting statements following a predetermined format. A 2-round modified Delphi method was used to reach a consensus on voting statements, and the RAND/UCLA Appropriateness Method was used to quantify disagreement. 51 articles met the inclusion criteria. Only case reports, case series, and pharmacokinetic studies were identified, yielding a very low quality of evidence. Clinical data from 31 patients and toxicokinetic grading from 46 patients were abstracted. The workgroup concluded that phenytoin is moderately dialyzable (level of evidence = C) despite its high protein binding and made the following recommendations. ECTR would be reasonable in select cases of severe phenytoin poisoning (neutral recommendation, 3D). ECTR is suggested if prolonged coma is present or expected (graded 2D) and it would be reasonable if prolonged incapacitating ataxia is present or expected (graded 3D). If ECTR is used, it should be discontinued when clinical improvement is apparent (graded 1D). The preferred ECTR modality in phenytoin poisoning is intermittent hemodialysis (graded 1D), but hemoperfusion is an acceptable alternative if hemodialysis is not available (graded 1D). In summary, phenytoin appears to be amenable to extracorporeal removal. However, because of the low incidence of irreversible tissue injury or death related to phenytoin poisoning and the relatively limited effect of ECTR on phenytoin removal, the workgroup proposed the use of ECTR only in very select patients with severe phenytoin poisoning. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  8. Radon chamber for soil gas detectors

    International Nuclear Information System (INIS)

    Andersson, P.

    1987-01-01

    Swedish Geological Co (SGAB) has designed and constructed a chamber for the calibration of detectors and instruments intended for the measurement of radon-222 in soil gas. In the chamber radon detectors may be exposed in a model environment which simulates ground conditions with respect to radon concentration, temperature and humidity. Also included in the research project is the development of methods for calibration procedures, together with test measurements. In general, these measurements indicate that the radon detectors tested are sufficiently accurate and reliable for radon measurements in Swedish soils if they are calibrated in an environment which simulates ground conditions. (orig./HP)

  9. Improvement of Swirl Chamber Structure of Swirl-Chamber Diesel Engine Based on Flow Field Characteristics

    Directory of Open Access Journals (Sweden)

    Wenhua Yuan

    2014-10-01

    Full Text Available In order to improve combustion characteristic of swirl chamber diesel engine, a simulation model about a traditional cylindrical flat-bottom swirl chamber turbulent combustion diesel engine was established within the timeframe of the piston motion from the bottom dead centre (BDC to the top dead centre (TDC with the fluent dynamic mesh technique and flow field vector of gas in swirl chamber and cylinder; the pressure variation and temperature variation were obtained and a new type of swirl chamber structure was proposed. The results reveal that the piston will move from BDC; air in the cylinder is compressed into the swirl chamber by the piston to develop a swirl inside the chamber, with the ongoing of compression; the pressure and temperature are also rising gradually. Under this condition, the demand of diesel oil mixing and combusting will be better satisfied. Moreover, the new structure will no longer forma small fluid retention zone at the lower end outside the chamber and will be more beneficial to the mixing of fuel oil and air, which has presented a new idea and theoretical foundation for the design and optimization of swirl chamber structure and is thus of good significance of guiding in this regard.

  10. Evaluation of one-dimensional and two-dimensional volatility basis sets in simulating the aging of secondary organic aerosol with smog-chamber experiments.

    Science.gov (United States)

    Zhao, Bin; Wang, Shuxiao; Donahue, Neil M; Chuang, Wayne; Hildebrandt Ruiz, Lea; Ng, Nga L; Wang, Yangjun; Hao, Jiming

    2015-02-17

    We evaluate the one-dimensional volatility basis set (1D-VBS) and two-dimensional volatility basis set (2D-VBS) in simulating the aging of SOA derived from toluene and α-pinene against smog-chamber experiments. If we simulate the first-generation products with empirical chamber fits and the subsequent aging chemistry with a 1D-VBS or a 2D-VBS, the models mostly overestimate the SOA concentrations in the toluene oxidation experiments. This is because the empirical chamber fits include both first-generation oxidation and aging; simulating aging in addition to this results in double counting of the initial aging effects. If the first-generation oxidation is treated explicitly, the base-case 2D-VBS underestimates the SOA concentrations and O:C increase of the toluene oxidation experiments; it generally underestimates the SOA concentrations and overestimates the O:C increase of the α-pinene experiments. With the first-generation oxidation treated explicitly, we could modify the 2D-VBS configuration individually for toluene and α-pinene to achieve good model-measurement agreement. However, we are unable to simulate the oxidation of both toluene and α-pinene with the same 2D-VBS configuration. We suggest that future models should implement parallel layers for anthropogenic (aromatic) and biogenic precursors, and that more modeling studies and laboratory research be done to optimize the "best-guess" parameters for each layer.

  11. The effects of extracorporeal shock wave therapy on the pain and function of patients with degenerative knee arthritis.

    Science.gov (United States)

    Lee, Ji-Hyun; Lee, Sangyong; Choi, SeokJoo; Choi, Yoon-Hee; Lee, Kwansub

    2017-03-01

    [Purpose] The purpose of this study was to identify the effects of extracorporeal shock wave therapy on the pain and function of patients with degenerative knee arthritis. [Subjects and Methods] Twenty patients with degenerative knee arthritis were divided into a conservative physical therapy group (n=10) and an extracorporeal shock wave therapy group (n=10). Both groups received general conservative physical therapy, and the extracorporeal shock wave therapy was additionally treated with extracorporeal shock wave therapy after receiving conservative physical therapy. Both groups were treated three times a week over a four-week period. The visual analogue scale was used to evaluate pain in the knee joints of the subjects, and the Korean Western Ontario and McMaster Universities Osteoarthritis Index was used to evaluate the function of the subjects. [Results] The comparison of the visual analogue scale and Korean Western Ontario and McMaster Universities Osteoarthritis Index scores within each group before and after the treatment showed statistically significant declines in scores in both the conservative physical therapy group and extracorporeal shock wave therapy group. A group comparison after the treatment showed statistically significant differences in these scores in the extracorporeal shock wave therapy group and the conservative physical therapy group. [Conclusion] extracorporeal shock wave therapy may be a useful nonsurgical intervention for reducing the pain of patients with degenerative knee arthritis and improving these patients' function.

  12. [Development of a microenvironment test chamber for airborne microbe research].

    Science.gov (United States)

    Zhan, Ningbo; Chen, Feng; Du, Yaohua; Cheng, Zhi; Li, Chenyu; Wu, Jinlong; Wu, Taihu

    2017-10-01

    One of the most important environmental cleanliness indicators is airborne microbe. However, the particularity of clean operating environment and controlled experimental environment often leads to the limitation of the airborne microbe research. This paper designed and implemented a microenvironment test chamber for airborne microbe research in normal test conditions. Numerical simulation by Fluent showed that airborne microbes were evenly dispersed in the upper part of test chamber, and had a bottom-up concentration growth distribution. According to the simulation results, the verification experiment was carried out by selecting 5 sampling points in different space positions in the test chamber. Experimental results showed that average particle concentrations of all sampling points reached 10 7 counts/m 3 after 5 minutes' distributing of Staphylococcus aureus , and all sampling points showed the accordant mapping of concentration distribution. The concentration of airborne microbe in the upper chamber was slightly higher than that in the middle chamber, and that was also slightly higher than that in the bottom chamber. It is consistent with the results of numerical simulation, and it proves that the system can be well used for airborne microbe research.

  13. Understand ATLAS NSW Thin Gap Chamber from Garfield Simulation

    CERN Document Server

    Chapman, J; Diehl, E; Feng, H; Guan, L; Mikenberg, G; Smakhtin, V; Yu, J M; Zhou, B; Zhu, J; Zhao, Z

    2014-01-01

    The LHC will be upgraded in several phases with the goal of obtaining an instantaneous lumi- nosity of 5-7 x 10^34 cm-2s-s at the center of mass energy of 14 TeV and integrated luminosity of 3000 fb-1. In order to profit from the high luminosity and high energy runs of the LHC, the ATLAS collaboration plans to upgrade the present endcap small wheel muon spectrometer to im- prove the muon triggering as well as precision tracking. The proposed New Small Wheel (nSW) will be composed of two four-layer Micromegas detectors (MM) detector sandwiched between two four-layer small-strip Thin Gap Chambers (sTGC) quadruplets, where MM for precision tracking and sTGC for Level-1 triggering. In this paper, we focus on the Garfield [ 1 ] simulation of the sTGC detector to understand its timing performance and charge production. We also stud- ied the sTGC timing under different magnetic fields and high voltages. These studies provide important guide lines for the sTGC detector and electronics development.

  14. Extracorporeal gas exchange and spontaneous breathing for the treatment of acute respiratory distress syndrome: an alternative to mechanical ventilation?*.

    Science.gov (United States)

    Langer, Thomas; Vecchi, Vittoria; Belenkiy, Slava M; Cannon, Jeremy W; Chung, Kevin K; Cancio, Leopoldo C; Gattinoni, Luciano; Batchinsky, Andriy I

    2014-03-01

    Venovenous extracorporeal gas exchange is increasingly used in awake, spontaneously breathing patients as a bridge to lung transplantation. Limited data are available on a similar use of extracorporeal gas exchange in patients with acute respiratory distress syndrome. The aim of this study was to investigate the use of extracorporeal gas exchange in awake, spontaneously breathing sheep with healthy lungs and with acute respiratory distress syndrome and describe the interactions between the native lung (healthy and diseased) and the artificial lung (extracorporeal gas exchange) in this setting. Laboratory investigation. Animal ICU of a governmental laboratory. Eleven awake, spontaneously breathing sheep on extracorporeal gas exchange. Sheep were studied before (healthy lungs) and after the induction of acute respiratory distress syndrome via IV injection of oleic acid. Six gas flow settings (1-10 L/min), resulting in different amounts of extracorporeal CO2 removal (20-100% of total CO2 production), were tested in each animal before and after the injury. Respiratory variables and gas exchange were measured for every gas flow setting. Both healthy and injured sheep reduced minute ventilation according to the amount of extracorporeal CO2 removal, up to complete apnea. However, compared with healthy sheep, sheep with acute respiratory distress syndrome presented significantly increased esophageal pressure variations (25 ± 9 vs 6 ± 3 cm H2O; p 80% of total CO2 production). Spontaneous ventilation of both healthy sheep and sheep with acute respiratory distress syndrome can be controlled via extracorporeal gas exchange. If this holds true in humans, extracorporeal gas exchange could be used in awake, spontaneously breathing patients with acute respiratory distress syndrome to support gas exchange. A deeper understanding of the pathophysiology of spontaneous breathing during acute respiratory distress syndrome is however warranted in order to be able to propose

  15. Frequency of stone clearance after extracorporeal shockwave ...

    African Journals Online (AJOL)

    Objective: To determine the rate of stone clearance after extracorporeal shockwave lithotripsy (ESWL) for renal stones in adult patients with renal insufficiency. Subjects and methods: This is a cross-sectional descriptive study of 117 adult patients who underwent ESWL. The indications for ESWL were determined by the ...

  16. Extracorporeal total artificial heart as bailout surgery.

    Science.gov (United States)

    Perrodin, Stéphanie F; Muller, Olivier; Gronchi, Fabrizio; Liaudet, Lucas; Hullin, Roger; Kirsch, Matthias

    2017-03-01

    We report the use of a total extracorporeal heart for uncontrolled bleeding following a proximal left anterior descending artery perforation, using two centrifugal ventricular assist devices after heart explantation. The literature describing similar techniques and patient outcomes for this "bailout" technique are reviewed. © 2017 Wiley Periodicals, Inc.

  17. A space simulation test chamber development for the investigation of radiometric properties of materials

    Science.gov (United States)

    Enlow, D. L.

    1972-01-01

    The design, fabrication, and preliminary utilization of a thermal vacuum space simulation facility are discussed. The facility was required to perform studies on the thermal radiation properties of materials. A test chamber was designed to provide high pumping speed, low pressure, a low photon level radiation background (via high emissivity, coated, finned cryopanels), internal heat sources for rapid warmup, and rotary and linear motion of the irradiated materials specimen. The radiation detection system consists of two wideband infrared photoconductive detectors, their cryogenic coolers, a cryogenic-cooled blackbody source, and a cryogenic-cooled optical radiation modulator.

  18. Is Climate Simulation in Growth Chambers Necessary?

    Science.gov (United States)

    Z.M. Wang; K.H. Johnsen; M.J. Lechowicz

    1999-01-01

    In the expression of their genetic potential as phenotypes, trees respond to environmental cues such as photoperiod, temperature and soil and atmospheric water. However, growth chamber experiments often utilize simple and standard environmental conditions that might not provide these important environmental signals. We conducted a study to compare seedling growth in...

  19. Extracorporeal shockwave therapy in musculoskeletal disorders

    OpenAIRE

    Wang, Ching-Jen

    2012-01-01

    Abstract The sources of shockwave generation include electrohydraulic, electromagnetic and piezoelectric principles. Electrohydraulic shockwaves are high-energy acoustic waves generated under water explosion with high voltage electrode. Shockwave in urology (lithotripsy) is primarily used to disintegrate urolithiasis, whereas shockwave in orthopedics (orthotripsy) is not used to disintegrate tissues, rather to induce tissue repair and regeneration. The application of extracorporeal shockwave ...

  20. Simulation of the energy response of the I.S.O.C.A.L. IV pressurised re-entrant well type ionization chamber using the Penelope Monte-Carlo code

    International Nuclear Information System (INIS)

    Kryeziu, D.; Tschurlovits, M.; Kreuziger, M.; Maringer, F.J.

    2006-01-01

    In radiation metrology, pressurized ionization chambers are essential tools in secondary standard laboratories as relative calibration instruments.Calculations of the calibration figures for different radionuclides are very important parameters for radioactivity measurements. The calibration figures for the I.S.O.C.A.L. IV pressurized re-entrant ionization chamber (also called well-type ionisation chamber) are calculated here using the P.E.N.E.L.O.P.E.-2003 Monte-Carlo Code. In order to test and validate the Monte Carlo simulation, calculated and experimental calibration figures are compared. The task of this work was to calculate the activity of a radioactive solution when no experimental calibration figures are available as well as to improve the accuracy of activity measurements. The chamber is filled with nitrogen gas at 1 MPa pressure. The simulated models of the chamber are designed by means of reduced quadric equation applying the appropriate transformations including: a rotation defined through the Euler angles, an expansion along the directions of the axes and a translation defined by the components of the displacement vector t. The simulated geometries are defined for the cases:without shielding; lead shielding and lead and copper shielding. The effect of density variations of the nitrogen gas on the sensitivity of such ionization chambers has been investigated. The Penelope Monte-Carlo code is also used to examine the effects of using lead and copper shields. The sensitivity to electrons is evaluated as well. (authors)

  1. Extracorporeal shock waves lithotripsy of urinary organs in patients with one kidney

    Directory of Open Access Journals (Sweden)

    Zogović Jezdimir

    2002-01-01

    Full Text Available Extracorporeal Shock Waves Lithotripsy (ESWL is a method of choice in the treatment of lithiasis. Surgical treatment is reduced to minimum, which in our case means 1-2%. Contraindications for using this method are: blood coagulation disorders, manifest tuberculosis, pregnancy, over obesity. Thanks to appropriate indications and technique which is used in an adequate way as well as to various endurological manipulations, removal of a stone by this method is safe, trauma is minimised, which is very important for patients with one kidney. During the last three years, usually in hospital conditions, 57 patients were treated in this way. Removal of a stone was performed by Extracorporeal Shock Waves Lithotripsy as mono therapy in 30 (53% patients; Extracorporeal Shock Waves Lithotripsy by using Double-J catheter in 16 (28% patients; Extracorporeal Lithotripsy with urine derivation by percutaneous nephrostome in 11 (19% patients. Endurological methods were used in 27 patients. Disintegration of stone was performed in the proper way. Full success was reached. Two patients had incrustation of ureteral catheter which had to be removed by surgery. In two other patients with inferior function of one kidney, after brief obstruction, hemodialisis was performed. Our results confirm that this method is nonaggressive, tech nically perfect for disintegration of urineorgans stone on all levels followed by small complications which are often solved by endoscopie manipulations.

  2. Cerebral aspects of neonatal extracorporeal membrane oxygenation: a review.

    NARCIS (Netherlands)

    Mol, A.C. de; Liem, K.D.; Heijst, A.F.J. van

    2013-01-01

    Background: Neonatal extracorporeal membrane oxygenation (ECMO) is a lifesaving therapeutic approach in newborns suffering from severe, but potentially reversible, respiratory insufficiency, mostly complicated by neonatal persistent pulmonary hypertension. However, cerebral damage, intracerebral

  3. Prospective longitudinal evaluation of lung function during the first year of life after extracorporeal membrane oxygenation

    NARCIS (Netherlands)

    Hofhuis, W.; Hanekamp, M.N.; Ijsselstijn, H.; Nieuwhof, E.M.; Hop, W.C.J.; Tibboel, D.; Jongste, J.C. de; Merkus, P.J.F.M.

    2011-01-01

    OBJECTIVE: To collect longitudinal data on lung function in the first year of life after extracorporeal membrane oxygenation and to evaluate relationships between lung function and perinatal factors. Longitudinal data on lung function in the first year of life after extracorporeal membrane

  4. Comparison of the effectiveness of local corticosteroid injection and extracorporeal shock wave therapy in patients with lateral epicondylitis.

    Science.gov (United States)

    Beyazal, Münevver Serdaroğlu; Devrimsel, Gül

    2015-12-01

    [Purpose] This study aimed to determine and compare the effectiveness of extracorporeal shock wave therapy and local corticosteroid injection in patients with lateral epicondylitis. [Subjects and Methods] Sixty-four patients with lateral epicondylitis were randomly divided into extracorporeal shock wave therapy and steroid injection groups. Patients were evaluated using hand grip strength, visual analog scale, and short-form McGill pain questionnaire at baseline and at 4 and 12 weeks post-treatment. [Results] Both groups showed statistically significant increase in hand grip strength and decreases on the visual analog scale and short form McGill pain questionnaire overtime. There was no statistically significant difference in the percentage of improvement in hand grip strength and on the short-form McGill pain questionnaire between groups at 4 weeks post-treatment, whereas the extracorporeal shock wave therapy group showed better results on the visual analog scale. The percentages of improvements in all 3 parameters were higher in the extracorporeal shock wave therapy group than in the injection group at 12 weeks post-treatment. [Conclusion] Both the extracorporeal shock wave therapy and steroid injection were safe and effective in the treatment of lateral epicondylitis. However, extracorporeal shock wave therapy demonstrated better outcomes than steroid injection at the long-term follow-up.

  5. Numerical simulations of mixing conditions and aerosol dynamics in the CERN CLOUD chamber

    CERN Document Server

    Voigtländer, J; Rondo, L; Kürten, A; Stratmann, F

    2012-01-01

    To study the effect of galactic cosmic rays on aerosols and clouds, the Cosmics Leaving OUtdoor Droplets (CLOUD) project was established. Experiments are carried out at a 26.1 m3 tank at CERN (Switzerland). In the experiments, the effect of ionizing radiation on H2SO4 particle formation and growth is investigated. To evaluate the experimental configuration, the experiment was simulated using a coupled multidimensional computational fluid dynamics (CFD) – particle model. In the model the coupled fields of gas/vapor species, temperature, flow velocity and particle properties were computed to investigate mixing state and mixing times of the CLOUD tank's contents. Simulation results show that a 1-fan configuration, as used in first experiments, may not be sufficient to ensure a homogeneously mixed chamber. To mix the tank properly, two fans and sufficiently high fan speeds are necessary. The 1/e response times for instantaneous changes of wall temperature and saturation ratio were found to be in the order of fe...

  6. Extracorporeal Cardiopulmonary Resuscitation Among Patients with Structurally Normal Hearts.

    Science.gov (United States)

    Conrad, Stephanie J; Bridges, Brian C; Kalra, Yuvraj; Pietsch, John B; Smith, Andrew H

    Extracorporeal cardiopulmonary resuscitation (eCPR) has been well described as a rescue therapy in refractory cardiac arrest among patients with congenital heart disease. The purpose of this retrospective analysis of data from the Extracorporeal Life Support Organization was to evaluate outcomes of eCPR in patients with structurally normal hearts and to identify risk factors that may contribute to mortality. During the study period, 1,431 patients met inclusion criteria. Median age was 16 years. Overall survival to hospital discharge was 32%. Conditional logistic regression demonstrated an independent survival benefit among smaller patients, patients with a lower partial pressure of carbon dioxide (PaCO2) on cannulation, and those with a shorter duration from intubation to eCPR cannulation. A diagnosis of sepsis was independently associated with a nearly threefold increase in odds of mortality, whereas the diagnosis of myocarditis portended a more favorable outcome. Neurologic complications, pulmonary hemorrhage, disseminated intravascular coagulation, CPR, pH less than 7.20, and hyperbilirubinemia after eCPR cannulation were independently associated with an increase in odds of mortality. When utilizing eCPR in patients with structurally normal hearts, a diagnosis of sepsis is independently associated with mortality, whereas a diagnosis of myocarditis is protective. Neurologic complications and pulmonary hemorrhage while on extracorporeal membrane oxygenation (ECMO) are independently associated with mortality.

  7. Development, test, and simulation of an influence drift chamber

    International Nuclear Information System (INIS)

    Lippert, C.

    1992-07-01

    The experiment PS185 measuring the reaction anti pp → anti YY with strangeness S = 1 hyperons is a unique tool to study the process of anti ss quark pair creation. The so far measured anti ΛΛ and anti ΛΣ 0 channels have stimulated a lot of theoretical work and will be complemented by the charged Σ-channels anti Σ + Σ + and anti Σ - Σ - . Therefore, the PS185 apparatus has to be extended by a microvertex-detector with good spatial resolution and high rate capability. Last years in Juelich such a detector, the Induction Drift Chamber, was developed. A wire plane consists of alternating potential wires (20 μm) and anodes (7μm) asymmetrically positioned between two cathode foils defining one independent chamber. The good track resolution (≤ 25 μm) for perpendicular tracks even for high rates (≥ 10 6 events/(sec x mm 2 )) is achieved by evaluate the induced signals of the potential wires, which measure the azimuthal avalanche position with respect to the anodes. An expression is derived to describe the principles of the induced signals so that the simulation of the IDC is in good agreement with the experimental data. One central point is the derivation of an algorithm for inclined tracks. To overcome limits in the spatial resolution which arise from the fluctuation of ionisation loss, a Flash-ADC read out was used, which also gives the possibility to digitalize the track inside one plane. For the 400 channels in two FADC-Crates a real time data acquisition system with interrupt processing was developed on a VME-processor so that an event rate ≥ 100 Hz by an event length ≥ 1 kByte could be reached. The mechanical construction of the IDC allows a stack of independent planes to be built with a height of 3.5 mm for each. Results of two test runs measuring the spatial resolution are reported. (orig.) [de

  8. Extracorporeal circuits and autoregulation: effect of albumin coating

    NARCIS (Netherlands)

    Borgdorff, P.; Kok, W. E.; van den Bos, G. C.

    1992-01-01

    Autoregulation of muscle blood flow often is difficult to demonstrate when extracorporeal perfusion is used. This could be caused by contact of blood and foreign material. Accordingly, we tested whether autoregulation is preserved when the system is coated with albumin. Polyurethane tubing between

  9. Predictability of the individual clinical outcome of extracorporeal shock wave therapy for cellulite

    OpenAIRE

    Schlaudraff, Kai-Uwe; Kiessling, Maren C; Császár, Nikolaus BM; Schmitz, Christoph

    2014-01-01

    Kai-Uwe Schlaudraff,1 Maren C Kiessling,2 Nikolaus BM Császár,2 Christoph Schmitz21Concept Clinic, Geneva, Switzerland; 2Department of Anatomy II, Ludwig-Maximilians-University of Munich, Munich, GermanyBackground: Extracorporeal shock wave therapy has been successfully introduced for the treatment of cellulite in recent years. However, it is still unknown whether the individual clinical outcome of cellulite treatment with extracorporeal shock wave therapy can be predict...

  10. Lateral epicondylitis: This is still a main indication for extracorporeal shockwave therapy.

    Science.gov (United States)

    Thiele, S; Thiele, R; Gerdesmeyer, L

    2015-12-01

    Extracorporeal shockwave therapy (ESWT) is used in a number of indications in the medical field. A number of tendinopathies show good and excellent results due to evidence based medicine. The treatment of lateral epicondylitis is known to show conflicting results. This overview of the published RCT's on ESWT for lateral epicondylitis tries to show the reasons for this conflicting data-base and point out, why we think that this is still a main indication for extracorporeal shockwave therapy. Copyright © 2015. Published by Elsevier Ltd.

  11. Venturi vacuum systems for hypobaric chamber operations.

    Science.gov (United States)

    Robinson, R; Swaby, G; Sutton, T; Fife, C; Powell, M; Butler, B D

    1997-11-01

    Physiological studies of the effects of high altitude on man often require the use of a hypobaric chamber to simulate the reduced ambient pressures. Typical "altitude" chambers in use today require complex mechanical vacuum systems to evacuate the chamber air, either directly or via reservoir system. Use of these pumps adds to the cost of both chamber procurement and maintenance, and service of these pumps requires trained support personnel and regular upkeep. In this report we describe use of venturi vacuum pumps to perform the function of mechanical vacuum pumps for human and experimental altitude chamber operations. Advantages of the venturi pumps include their relatively low procurement cost, small size and light weight, ease of installation and plumbing, lack of moving parts, and independence from electrical power sources, fossil fuels and lubricants. Conversion of three hyperbaric chambers to combined hyper/hypobaric use is described.

  12. Polarity effects and apparent ion recombination in microionization chambers

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Jessica R., E-mail: miller@humonc.wisc.edu [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 and Department of Human Oncology, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States); Hooten, Brian D. [Standard Imaging, Middleton, Wisconsin 53562 (United States); Micka, John A.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

    2016-05-15

    Purpose: Microchambers demonstrate anomalous voltage-dependent polarity effects. Existing polarity and ion recombination correction factors do not account for these effects. As a result, many commercial microchamber models do not meet the specification of a reference-class ionization chamber as defined by the American Association of Physicists in Medicine. The purpose of this investigation is to determine the cause of these voltage-dependent polarity effects. Methods: A series of microchamber prototypes were produced to isolate the source of the voltage-dependent polarity effects. Parameters including ionization-chamber collecting-volume size, stem and cable irradiation, chamber assembly, contaminants, high-Z materials, and individual chamber components were investigated. Measurements were performed with electrodes coated with graphite to isolate electrode conductivity. Chamber response was measured as the potential bias of the guard electrode was altered with respect to the collecting electrode, through the integration of additional power supplies. Ionization chamber models were also simulated using COMSOL Multiphysics software to investigate the effect of a potential difference between electrodes on electric field lines and collecting volume definition. Results: Investigations with microchamber prototypes demonstrated that the significant source of the voltage-dependent polarity effects was a potential difference between the guard and collecting electrodes of the chambers. The voltage-dependent polarity effects for each prototype were primarily isolated to either the guard or collecting electrode. Polarity effects were reduced by coating the isolated electrode with a conductive layer of graphite. Polarity effects were increased by introducing a potential difference between the electrodes. COMSOL simulations further demonstrated that for a given potential difference between electrodes, the collecting volume of the chamber changed as the applied voltage was altered

  13. Dense pulmonary opacification in neonates treated with extracorporeal membrane oxygenation

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, A.E.; Cornish, J.D.; Null, D.M.

    1986-09-01

    Chest radiographic findings in three neonates with respiratory failure secondary to meconium aspiration treated with extracorporeal membrane oxygenation (ECMO) are described. The degree of pulmonary opacification on the chest radiographs failed to correlate with the patients' clinical status as measured by the arterial oxygen levels but correlated well with the peak airway pressure (PAP) and continuous positive airway pressure (CPAP) settings on the mechanical ventilator. Because a variable portion of the arterial blood oxygenation is performed by the extracorporeal membrane oxygenator and unusually large fluctuations in airway pressure settings can occur in these patients while on ECMO, it is important to realize that the chest radiography may not be an accurate predictor of the patients' clinical status.

  14. Dense pulmonary opacification in neonates treated with extracorporeal membrane oxygenation

    International Nuclear Information System (INIS)

    Schlesinger, A.E.; Cornish, J.D.; Null, D.M.

    1986-01-01

    Chest radiographic findings in three neonates with respiratory failure secondary to meconium aspiration treated with extracorporeal membrane oxygenation (ECMO) are described. The degree of pulmonary opacification on the chest radiographs failed to correlate with the patients' clinical status as measured by the arterial oxygen levels but correlated well with the peak airway pressure (PAP) and continuous positive airway pressure (CPAP) settings on the mechanical ventilator. Because a variable portion of the arterial blood oxygenation is performed by the extracorporeal membrane oxygenator and unusually large fluctuations in airway pressure settings can occur in these patients while on ECMO, it is important to realize that the chest radiography may not be an accurate predictor of the patients' clinical status. (orig.)

  15. 21 CFR 876.5990 - Extracorporeal shock wave lithotripter.

    Science.gov (United States)

    2010-04-01

    ..., control console, imaging/localization system, and patient table. Prior to treatment, the urinary stone is targeted using either an integral or stand-alone localization/imaging system. Shock waves are typically... shock wave lithotripter. (a) Identification. An extracorporeal shock wave lithotripter is a device that...

  16. Geant4 simulation of ion chambers response to 60Co spectrum of LNMRI/IRD Shepherd 81-14D Radiator

    Science.gov (United States)

    Queiroz Filho, P. P.; Da Silva, C. N. M.

    2018-03-01

    The National Ionizing Radiation Metrology Laboratory of the Radioprotection and Dosimetry Institute (LNMRI / IRD) has recently acquired a Shepherd 81-14D Radiator. In this work we simulate, using Geant4, the behavior with the inverse square law radiation for 3 models of PTW spherical chambers used in radioprotection, a relevant information to planning the measurements. We did the corrections for the attenuation and scattering in the air for each distance, where we used the 60Co spectrum simulated previously.

  17. Quantification of Postmembrane Gaseous Microembolization During Venoarterial Extracorporeal Membrane Oxygenation.

    Science.gov (United States)

    Jiao, York; Gipson, Keith E; Bonde, Pramod; Mangi, Abeel; Hagberg, Robert; Rosinski, David J; Gross, Jeffrey B; Schonberger, Robert B

    Prolonged use of venoarterial extracorporeal membrane oxygenation (VA ECMO) may be complicated by end-organ dysfunction. Although gaseous microemboli (GME) are thought to damage end organs during cardiopulmonary bypass, patient exposures to GME have not been well characterized during VA ECMO. We therefore performed an observational study of GME in adult VA ECMO patients, with correlation to clinical events during routine patient care. After institutional review board (IRB) approval, we used two Doppler probes to detect GME noninvasively in extracorporeal membrane oxygenation (ECMO) circuits on four patients for 15 hours total while also recording patient care events. We then conducted in vitro trials to compare Doppler signals with gold-standard measurements using an Emboli Detection and Classification EDAC quantifier (Luna Innnovations, Inc. Roanoke, VA) (Terumo Cardiovascular, Ann Arbor, MI) during simulated clinical interventions. Correlations between Doppler and EDAC data were used to estimate GME counts and volumes represented by clinical Doppler data. A total of 503 groups of Doppler peaks representing GME showers were observed, including 194 statistically larger showers during patient care activities containing 92% of total Doppler peaks. Intravenous injections accounted for an estimated 68% of GME and 88% of GME volume, whereas care involving movement accounted for an estimated 6% of GME and 3% of volume. Overall estimated embolic rates of 24,000 GME totaling 4 μl/hr rivals reported GME rates during cardiopulmonary bypass. Numerous GME are present in the postmembrane circuit during VA ECMO, raising concern for effects on microcirculation and organ dysfunction. Strategies to detect and minimize GME may be warranted to limit embolic exposures experienced by VA ECMO patients.

  18. Comparison of OH Reactivity Instruments in the Atmosphere Simulation Chamber SAPHIR.

    Science.gov (United States)

    Fuchs, H.; Novelli, A.; Rolletter, M.; Hofzumahaus, A.; Pfannerstill, E.; Edtbauer, A.; Kessel, S.; Williams, J.; Michoud, V.; Dusanter, S.; Locoge, N.; Zannoni, N.; Gros, V.; Truong, F.; Sarda Esteve, R.; Cryer, D. R.; Brumby, C.; Whalley, L.; Stone, D. J.; Seakins, P. W.; Heard, D. E.; Schoemaecker, C.; Blocquet, M.; Fittschen, C. M.; Thames, A. B.; Coudert, S.; Brune, W. H.; Batut, S.; Tatum Ernest, C.; Harder, H.; Elste, T.; Bohn, B.; Hohaus, T.; Holland, F.; Muller, J. B. A.; Li, X.; Rohrer, F.; Kubistin, D.; Kiendler-Scharr, A.; Tillmann, R.; Andres, S.; Wegener, R.; Yu, Z.; Zou, Q.; Wahner, A.

    2017-12-01

    Two campaigns were conducted performing experiments in the atmospheric simulation chamber SAPHIR at Forschungszentrum Jülich in October 2015 and April 2016 to compare hydroxyl (OH) radical reactivity (kOH) measurements. Chemical conditions were chosen either to be representative of the atmosphere or to test potential limitations of instruments. The results of these campaigns demonstrate that OH reactivity can be accurately measured for a wide range of atmospherically relevant chemical conditions (e.g. water vapor, nitrogen oxides, various organic compounds) by all instruments. The precision of the measurements is higher for instruments directly detecting hydroxyl radicals (OH), whereas the indirect Comparative Reactivity Method (CRM) has a higher limit of detection of 2s-1 at a time resolution of 10 to 15 min. The performances of the instruments were systematically tested by stepwise increasing, for example, the concentrations of carbon monoxide (CO), water vapor or nitric oxide (NO). In further experiments, mixtures of organic reactants were injected in the chamber to simulate urban and forested environments. Overall, the results show that instruments are capable of measuring OH reactivity in the presence of CO, alkanes, alkenes and aromatic compounds. The transmission efficiency in Teflon inlet lines could have introduced systematic errors in measurements for low-volatile organic compounds in some instruments. CRM instruments exhibited a larger scatter in the data compared to the other instruments. The largest differences to the reference were observed by CRM instruments in the presence of terpenes and oxygenated organic compounds. In some of these experiments, only a small fraction of the reactivity is detected. The accuracy of CRM measurements is most likely limited by the corrections that need to be applied in order to account for known effects of, for example, deviations from pseudo-first order conditions, nitrogen oxides or water vapor on the measurement

  19. Re-entry simulation chamber for thermo-mechanical characterisation of space materials

    Science.gov (United States)

    Liedtke, Volker

    2003-09-01

    During re-entry, materials and components are subject to very high thermal and mechanical loads. Any failure may cause loss of mission. Therefore, materials and components have to be tested under most rigid conditions to verify the suitability of the material and to verify the design of the components. The Re-Entry Simulation Chamber (RESiC) at ARC Seibersdorf research (ARCS) allows simulating the high thermal loads as well as complex mechanical load profiles that may occur during a re-entry; additionally, the influence of chemical reactions of materials with gaseous components of the atmosphere can be studied. The high vacuum chamber (better than 1×10-6 mbar) has a diameter of 650 mm and allows a sample height of 500 mm, or 1000 mm with extension flange. The gas dosing system is designed to emulate the increasing atmospheric pressure during the re-entry trajectory of a vehicle. Heating is performed by a 30 kW induction generator that allows a sufficiently rapid heating of larger components; electrically conductive materials such as metals or carbon fibre reinforced ceramics are directly heated, while for electrical insulators, susceptor plates or tubes will be employed. The uniaxial servo-hydraulic testing machine has a maximum load of 70 kN, either static or with a frequency of up to 70 Hz, with any given load profile (sinus, rectangular, triangular, ...). Strain measurements will be done by non-contacting laser speckle system for maximum flexibility and minimum instrumentation time effort (currently under application testing), or by strain gauges. All relevant process parameters are controlled and recorded by microcomputer. The highly sophisticated control software allows a convenient and reliable multi-channel data acquisition, e.g. temperatures at various positions of the test piece, pressure, loads, strains, and any other test data according to customer specifications; the data format is suitable for any further data processing. During the set-up and

  20. Extracorporeal circulatory systems in the interhospital transfer of critically ill patients: experience of a single institution

    International Nuclear Information System (INIS)

    Haneya, Assad; Philipp, Alois; Foltan, Maik; Camboni, Daniele; Rupprecht, Leopold; Puehler, Thomas; Hirt, Stephan; Hilker, Michael; Kobuch, Reinhard; Schmid, Christof; Arlt, Matthias; Mueller, Thomas

    2009-01-01

    Critically ill patients with acute circulatory failure cannot be moved to other institutions unless stabilized by mechanical support systems. Extracorporeal heart and lung assist systems are increasingly used as a bridge to end-organ recovery or transplantation, and as an ultimate rescue tool in cardiopulmonary resuscitation. From July 2001 to April 2008, we had 38 requests for extracorporeal support for interhospital transfer carried out by the air medical service. Respiratory failure was present in 29 patients, who were provided with pumpless extracorporeal lung assist (PECLA) or veno-venous extracorporeal membrane oxygenation (ECMO). Cardiac failure dominated in 9 patients, who underwent implantation of extracorporeal life support (ECLS). Underlying diseases were acute respiratory distress syndrome in 15 patients, pneumonia in 7, prior lung transplant status in 4, cardiogenic shock in 7, and septic shock in 4. All assist systems were connected via peripheral vessels by the Seldinger technique. Transport was uneventful in all cases with no technical failures. On arrival at the specialized care hospital, two patients had leg ischemia and underwent relocation of the arterial cannula. After a mean (SD) support of 5.1 (3.0) days for PECLA, 3.5 (2.9) days for ECLS, and 7.3 (5.8) days for ECMO, 60%, 66%, and 66% of patients, respectively, could be successfully weaned from the systems. Discharge rates were 45% for PECLA, 44% for ECLS, and 56% for ECMO. Our experience proves that minimized extracorporeal assist devices allow safe assistance of patients with isolated or combined heart and lung failure in need of interhospital transfer. Critically ill patients get a chance to reach a center of maximum medical care. (author)

  1. Numerical simulations of homogeneous freezing processes in the aerosol chamber AIDA

    Directory of Open Access Journals (Sweden)

    W. Haag

    2003-01-01

    Full Text Available The homogeneous freezing of supercooled H2SO4/H2O aerosols in an aerosol chamber is investigated with a microphysical box model using the activity parameterization of the nucleation rate by Koop et al. (2000. The simulations are constrained by measurements of pressure, temperature, total water mixing ratio, and the initial aerosol size distribution, described in a companion paper Möhler et al. (2003. Model results are compared to measurements conducted in the temperature range between 194 and 235 K, with cooling rates in the range between 0.5 and 2.6 K min-1, and at air pressures between 170 and 1000 hPa. The simulations focus on the time history of relative humidity with respect to ice, aerosol size distribution, partitioning of water between gas and particle phase, onset times of freezing, freezing threshold relative humidities, aerosol chemical composition at the onset of freezing, and the number of nucleated ice crystals. The latter four parameters can be inferred from the experiments, the former three aid in interpreting the measurements. Sensitivity studies are carried out to address the relative importance of uncertainties of basic quantities such as temperature, total H2O mixing ratio, aerosol size spectrum, and deposition coefficient of H2O molecules on ice. The ability of the numerical simulations to provide detailed explanations of the observations greatly increases confidence in attempts to model this process under real atmospheric conditions, for instance with regard to the formation of cirrus clouds or polar stratospheric ice clouds, provided that accurate temperature and humidity measurements are available.

  2. Evaluation of a special pencil ionization chamber by the Monte Carlo method

    International Nuclear Information System (INIS)

    Mendonca, Dalila; Neves, Lucio P.; Perini, Ana P.

    2015-01-01

    A special pencil type ionization chamber, developed at the Instituto de Pesquisas Energeticas e Nucleares, was characterized by means of Monte Carlo simulation to determine the influence of its components on its response. The main differences between this ionization chamber and commercial ionization chambers are related to its configuration and constituent materials. The simulations were made employing the MCNP-4C Monte Carlo code. The highest influence was obtained for the body of PMMA: 7.0%. (author)

  3. Can cellulite be treated with low-energy extracorporeal shock wave therapy?

    Science.gov (United States)

    Angehrn, Fiorenzo; Kuhn, Christoph; Voss, Axel

    2007-01-01

    The present study investigates the effects of low-energy defocused extracorporeal generated shock waves on collagen structure of cellulite afflicted skin. Cellulite measurement using high-resolution ultrasound technology was performed before and after low-energy defocused extracorporeal shock wave therapy (ESWT) in 21 female subjects. ESWT was applied onto the skin at the lateral thigh twice a week for a period of six weeks. Results provide evidence that low-energy defocused ESWT caused remodeling of the collagen within the dermis of the tested region. Improving device-parameters and therapy regimes will be essential for future development of a scientific based approach to cellulite treatment. PMID:18225463

  4. MIMO OTA Testing in Small Multi-Probe Anechoic Chamber Setups

    DEFF Research Database (Denmark)

    Llorente, Ines Carton; Fan, Wei; Pedersen, Gert F.

    2016-01-01

    OTA testing of MIMO capable terminals is often performed in large anechoic chambers, where planar waves impinging the test area are assumed. Furthermore, reflections from the chamber, and probe coupling are often considered negligible due to the large dimensions of the chamber. This paper...... investigates the feasibility of reducing the physical dimension of 2D multi-probe anechoic chamber setups for MIMO OTA testing, with the purpose of reducing the cost and space of the setup. In the paper, a channel emulation algorithm and chamber compensation technique are proposed for MIMO OTA testing in small...... anechoic chambers. The performance deterioration in a small anechoic chamber, i.e., with a ring radius of 0.5 m, is demonstrated via simulations....

  5. Blast from pressurized carbon dioxide released into a vented atmospheric chamber

    Science.gov (United States)

    Hansen, P. M.; Gaathaug, A. V.; Bjerketvedt, D.; Vaagsaether, K.

    2018-03-01

    This study describes the blast from pressurized carbon dioxide (CO2) released from a high-pressure reservoir into an openly vented atmospheric chamber. Small-scale experiments with pure vapor and liquid/vapor mixtures were conducted and compared with simulations. A motivation was to investigate the effects of vent size and liquid content on the peak overpressure and impulse response in the atmospheric chamber. The comparison of vapor-phase CO2 test results with simulations showed good agreement. This numerical code described single-phase gas dynamics inside a closed chamber, but did not model any phase transitions. Hence, the simulations described a vapor-only test into an unvented chamber. Nevertheless, the simulations reproduced the incident shock wave, the shock reflections, and the jet release inside the atmospheric chamber. The rapid phase transition did not contribute to the initial shock strength in the current test geometry. The evaporation rate was too low to contribute to the measured peak overpressure that was in the range of 15-20 kPa. The simulation results produced a calculated peak overpressure of 12 kPa. The liquid tests showed a significantly higher impulse compared to tests with pure vapor. Reducing the vent opening from 0.1 to 0.01 m2 resulted in a slightly higher impulse calculated at 100 ms. The influence of the vent area on the calculated impulse was significant in the vapor-phase tests, but not so clear in the liquid/vapor mixture tests.

  6. Extracorporeal irradiation of dog blood: the effects of a radiostrontium irradiator on blood stem cells (CFU-C)

    Energy Technology Data Exchange (ETDEWEB)

    Szemere, P.; Fliedner, T.M.; Nothdurft, W.; Breitig, D.

    1982-07-01

    The radiation sensitivity of dog blood stem cells was measured in vitro and in an extracorporeal circulation passing through a radiation field. It was established that the calculated D/sub 0/ was as low as 0.45 Gy. Investigating the cell killing rate in our equipment (Buchler type /sup 90/Sr device for extracorporeal irradiation), we found an overkill situation; the dose delivered was in excess of that which would be required for the total eradication of all stem cells in the peripheral blood passing through the radiation field. Various other types of devices used for extracorporeal irradiation of blood are also reviewed.

  7. Wenckebach upper rate response in single chamber pacemaker.

    Science.gov (United States)

    Barold, S S

    2000-07-01

    The Medtronic Minix pacemaker during normal function in the VVT mode was found to exhibit a Wenckenbach upper rate response similar to that of dual chamber devices. This behavior occurred only when the upper rate interval was longer than the pacemaker refractory period. In a single chamber device this response may simulate pacemaker malfunction.

  8. Tracking and vertex finding with drift chambers and neural networks

    International Nuclear Information System (INIS)

    Lindsey, C.

    1991-09-01

    Finding tracks, track vertices and event vertices with neural networks from drift chamber signals is discussed. Simulated feed-forward neural networks have been trained with back-propagation to give track parameters using Monte Carlo simulated tracks in one case and actual experimental data in another. Effects on network performance of limited weight resolution, noise and drift chamber resolution are given. Possible implementations in hardware are discussed. 7 refs., 10 figs

  9. Computational fluid dynamic (CFD) investigation of thermal uniformity in a thermal cycling based calibration chamber for MEMS

    Science.gov (United States)

    Gui, Xulong; Luo, Xiaobing; Wang, Xiaoping; Liu, Sheng

    2015-12-01

    Micro-electrical-mechanical system (MEMS) has become important for many industries such as automotive, home appliance, portable electronics, especially with the emergence of Internet of Things. Volume testing with temperature compensation has been essential in order to provide MEMS based sensors with repeatability, consistency, reliability, and durability, but low cost. Particularly, in the temperature calibration test, temperature uniformity of thermal cycling based calibration chamber becomes more important for obtaining precision sensors, as each sensor is different before the calibration. When sensor samples are loaded into the chamber, we usually open the door of the chamber, then place fixtures into chamber and mount the samples on the fixtures. These operations may affect temperature uniformity in the chamber. In order to study the influencing factors of sample-loading on the temperature uniformity in the chamber during calibration testing, numerical simulation work was conducted first. Temperature field and flow field were simulated in empty chamber, chamber with open door, chamber with samples, and chamber with fixtures, respectively. By simulation, it was found that opening chamber door, sample size and number of fixture layers all have effects on flow field and temperature field. By experimental validation, it was found that the measured temperature value was consistent with the simulated temperature value.

  10. Simulation of the saturation curve of the ionization chamber in overlapping pulsed radiation

    International Nuclear Information System (INIS)

    Park, Se Hwan; Kim, Yong Kyun; Kim, Han Soo; Kang, Sang Mook; Ha, Jang Ho

    2006-01-01

    Procedures for determination of collection efficiency in ionization chambers have been studied by numerous investigators. If the theoretical approach for air-filled ionization chambers exposed to continuous radiation is considered, the result in the near-saturation region is a linear relationship between ) (1/I(V) vs 1/V 2 , where I(V) is the current measured with the ionization chamber at a given polarization voltage V . For pulsed radiation beams, Boag developed a model and the resulted in a linear relationship between ) (1/I(V) and 1/V when the collection efficiency, f , is larger than 0.9. The assumption of the linear relationship of ) (1/I(V) with 1/V or 1/V 2 in the near-saturation region makes the determination of the saturation current simple, since the linear relationship may be determined with only two measured data points. The above discussion of the collection efficiency of the ionization chamber exposed to the pulsed radiation is valid only if each pulse is cleared before the next one occurs. The transit times of the ions in the chamber must be shorter than the time interval between the radiation pulses. Most of the previous works concerning the characteristics of the saturation curve of an ionization chamber in the pulsed beam were done for the case where the transit times of the ions were shorter than the interval between the radiation pulses. However, the experimental data for the intermediate case, where the ion transit time was comparable to the interval between the radiation pulses or the ion transit time was slightly longer than the interval between the radiation pulses, were rare. The saturation curves of the ionization chambers in the pulsed radiation were measured with the pulse beamed electron accelerator at the Korea Atomic Energy Research Institute (KAERI), where the ion transit times in the ionization chambers were longer than the time interval between the radiation pulses. We used two ionization chambers: one was a commercial thimble

  11. Extracorporeal Organ Support following Trauma: The Dawn of a New Era in Combat Casualty Critical Care

    Science.gov (United States)

    2013-01-01

    liver support has undergone significant technological advances. The Food and Drug Administration approved (December 2012) the Molecular Adsorbent Re...Williams & Wilkins Copyright © 2013 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. encephalopathy caused by...chronic liver disease decompen- sation. The Extracorporeal Liver Assist Device (ELAD) pro- vides continuous extracorporeal liver support with

  12. Factors affecting lower calyceal stone clearance after Extracorporeal ...

    African Journals Online (AJOL)

    Objective: Extracorporeal shock wave lithotripsy (ESWL) is one of the most commonly used procedures to remove renal calculi from the lower calyces. The aim of this work is to study the impact of radiological, anatomical and demographic factors on stone clearance after ESWL of lower calyceal calculi. Patients and ...

  13. Preauricular transmasseteric anteroparotid approach for extracorporeal fixation of mandibular condyle fractures

    Directory of Open Access Journals (Sweden)

    Rajasekhar Gali

    2016-01-01

    Full Text Available Introduction: Free grafting or extracorporeal fixation of traumatically displaced mandibular condyles is sometimes required in patients with severe anteromedial displacement of condylar head. Majority of the published studies report the use of a submandibular, retromandibular or preauricular incisions for the access which have demerits of limited visibility, access and potential to cause damage to facial nerve and other parotid gland related complications. Purpose: This retrospective clinical case record study was done to evaluate the preauricular transmasseteric anteroparotid (P-TMAP approach for open reduction and extracorporeal fixation of displaced and dislocated high condylar fractures of the mandible. Patients and Methods: This retrospective study involved search of clinical case records of seven patients with displaced and dislocated high condylar fractures treated by open reduction and extracorporeal fixation over a 3-year period. The parameters assessed were as follows: a the ease of access for retrieval, reimplantation and fixation of the proximal segment; b the postoperative approach related complications; c the adequacy of anatomical reduction and stability of fixation; d the occlusal changes; and the e TMJ function and radiological changes. Results: Accessibility and visibility were good. Accurate anatomical reduction and fixation were achieved in all the patients. The recorded complications were minimal and transient. Facial nerve (buccal branch palsy was noted in one patient with spontaneous resolution within 3 months. No cases of sialocele or Frey's syndrome were seen. Conclusion: The P-TMAP approach provides good access for open reduction and extracorporeal fixation of severely displaced condylar fractures. It facilitates retrieval, transplantation, repositioning, fixing the condyle and also reduces the chances of requirement of a vertical ramus osteotomy. It gives straight-line access to condylar head and ramus thereby

  14. Preauricular transmasseteric anteroparotid approach for extracorporeal fixation of mandibular condyle fractures.

    Science.gov (United States)

    Gali, Rajasekhar; Devireddy, Sathya Kumar; Venkata, Kishore Kumar Rayadurgam; Kanubaddy, Sridhar Reddy; Nemaly, Chaithanyaa; Dasari, Mallikarjuna

    2016-01-01

    Free grafting or extracorporeal fixation of traumatically displaced mandibular condyles is sometimes required in patients with severe anteromedial displacement of condylar head. Majority of the published studies report the use of a submandibular, retromandibular or preauricular incisions for the access which have demerits of limited visibility, access and potential to cause damage to facial nerve and other parotid gland related complications. This retrospective clinical case record study was done to evaluate the preauricular transmasseteric anteroparotid (P-TMAP) approach for open reduction and extracorporeal fixation of displaced and dislocated high condylar fractures of the mandible. This retrospective study involved search of clinical case records of seven patients with displaced and dislocated high condylar fractures treated by open reduction and extracorporeal fixation over a 3-year period. The parameters assessed were as follows: a) the ease of access for retrieval, reimplantation and fixation of the proximal segment; b) the postoperative approach related complications; c) the adequacy of anatomical reduction and stability of fixation; d) the occlusal changes; and the e) TMJ function and radiological changes. Accessibility and visibility were good. Accurate anatomical reduction and fixation were achieved in all the patients. The recorded complications were minimal and transient. Facial nerve (buccal branch) palsy was noted in one patient with spontaneous resolution within 3 months. No cases of sialocele or Frey's syndrome were seen. The P-TMAP approach provides good access for open reduction and extracorporeal fixation of severely displaced condylar fractures. It facilitates retrieval, transplantation, repositioning, fixing the condyle and also reduces the chances of requirement of a vertical ramus osteotomy. It gives straight-line access to condylar head and ramus thereby permitting perpendicular placement of screws with minimal risk of damage to the facial

  15. Guidelines on the use of extracorporeal photopheresis.

    Science.gov (United States)

    Knobler, R; Berlin, G; Calzavara-Pinton, P; Greinix, H; Jaksch, P; Laroche, L; Ludvigsson, J; Quaglino, P; Reinisch, W; Scarisbrick, J; Schwarz, T; Wolf, P; Arenberger, P; Assaf, C; Bagot, M; Barr, M; Bohbot, A; Bruckner-Tuderman, L; Dreno, B; Enk, A; French, L; Gniadecki, R; Gollnick, H; Hertl, M; Jantschitsch, C; Jung, A; Just, U; Klemke, C-D; Lippert, U; Luger, T; Papadavid, E; Pehamberger, H; Ranki, A; Stadler, R; Sterry, W; Wolf, I H; Worm, M; Zic, J; Zouboulis, C C; Hillen, U

    2014-01-01

    After the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T-cell lymphoma was published in 1983 with its subsequent recognition by the FDA for its refractory forms, the technology has shown significant promise in the treatment of other severe and refractory conditions in a multi-disciplinary setting. Among the major studied conditions are graft versus host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection and inflammatory bowel disease. In order to provide recognized expert practical guidelines for the use of this technology for all indications the European Dermatology Forum (EDF) proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. These guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. © 2013 The Authors. Journal of the European Academy of Dermatology and Venereology published by John Wiley & Sons Ltd on behalf of European Academy of Dermatology and Venereology.

  16. CESAR: conventional ventilatory support vs extracorporeal membrane oxygenation for severe adult respiratory failure

    Directory of Open Access Journals (Sweden)

    Mugford Miranda

    2006-12-01

    Full Text Available Abstract Background An estimated 350 adults develop severe, but potentially reversible respiratory failure in the UK annually. Current management uses intermittent positive pressure ventilation, but barotrauma, volutrauma and oxygen toxicity can prevent lung recovery. An alternative treatment, extracorporeal membrane oxygenation, uses cardio-pulmonary bypass technology to temporarily provide gas exchange, allowing ventilator settings to be reduced. While extracorporeal membrane oxygenation is proven to result in improved outcome when compared to conventional ventilation in neonates with severe respiratory failure, there is currently no good evidence from randomised controlled trials to compare these managements for important clinical outcomes in adults, although evidence from case series is promising. Methods/Design The aim of the randomised controlled trial of Conventional ventilatory support vs extracorporeal membrane oxygenation for severe adult respiratory failure (CESAR is to assess whether, for patients with severe, but potentially reversible, respiratory failure, extracorporeal membrane oxygenation will increase the rate of survival without severe disability ('confined to bed' and 'unable to wash or dress' by six months post-randomisation, and be cost effective from the viewpoints of the NHS and society, compared to conventional ventilatory support. Following assent from a relative, adults (18–65 years with severe, but potentially reversible, respiratory failure (Murray score ≥ 3.0 or hypercapnea with pH Discussion Analysis will be based on intention to treat. A concurrent economic evaluation will also be performed to compare the costs and outcomes of both treatments.

  17. More realistic simulation of the response of an ionization chamber

    International Nuclear Information System (INIS)

    Torii, T.; Nozaki, T.; Ando, H.

    1994-01-01

    In order to study the consequence of geometrical modeling of a finger tip ionization chamber and the difference of the calculated results using two Monte Carlo codes EGS4 and ITS3.0, the energy responses of an ionization chamber have been calculated. In the EGS4 calculation, it has been developed a versatile user code PRESTA-CG to calculate the response of radiation detectors with more complicated geometrical design by the combinatorial geometry (CG) method. This paper presents comparisons of the energy responses between these codes. (author)

  18. Prospective longitudinal evaluation of lung function during the first year of life after extracorporeal membrane oxygenation.

    Science.gov (United States)

    Hofhuis, Ward; Hanekamp, Manon N; Ijsselstijn, Hanneke; Nieuwhof, Eveline M; Hop, Wim C J; Tibboel, Dick; de Jongste, Johan C; Merkus, Peter J F M

    2011-03-01

    To collect longitudinal data on lung function in the first year of life after extracorporeal membrane oxygenation and to evaluate relationships between lung function and perinatal factors. Longitudinal data on lung function in the first year of life after extracorporeal membrane oxygenation are lacking. Prospective longitudinal cohort study. Outpatient clinic of a tertiary level pediatric hospital. The cohort consisted of 64 infants; 33 received extracorporeal membrane oxygenation for meconium aspiration syndrome, 14 for congenital diaphragmatic hernia, four for sepsis, six for persistent pulmonary hypertension of the neonate, and seven for respiratory distress syndrome of infancy. Evaluation was at 6 mos and 12 mos; 39 infants were evaluated at both time points . None. Functional residual capacity and forced expiratory flow at functional residual capacity were measured and expressed as z score. Mean (sem) functional residual capacities in z score were 0.0 (0.2) and 0.2 (0.2) at 6 mos and 12 mos, respectively. Mean (sem) forced expiratory flow was significantly below average (z score = 0) (p capacity significantly above normal: mean (sem) z score = 1.2 (0.5). Infants treated with extracorporeal membrane oxygenation have normal lung volumes and stable forced expiratory flows within normal range, although below average, within the first year of life. There is reason to believe, therefore, that extracorporeal membrane oxygenation either ameliorates the harmful effects of mechanical ventilation or somehow preserves lung function in the very ill neonate.

  19. Extracorporeal photopheresis: Review of technical aspects.

    Science.gov (United States)

    Arora, Satyam; Setia, Rasika

    2017-01-01

    Extracorporeal photochemotherapy (ECP) is considered as an immune modulating therapy majorly targeting the T cells of the Immune system. ECP induces an anti-inflammatory condition with tolerogenic responses without inducing a global immunosuppression state which is a typical feature of other therapeutic options such as steroids. Clinical indication of ECP has grown over time since its initial applications. Our review discusses the technical aspects of the concept of photopheresis with the available methods for its clinical applications.

  20. Evaluation of functioning of an extrapolation chamber using Monte Carlo method

    International Nuclear Information System (INIS)

    Oramas Polo, I.; Alfonso Laguardia, R.

    2015-01-01

    The extrapolation chamber is a parallel plate chamber and variable volume based on the Braff-Gray theory. It determines in absolute mode, with high accuracy the dose absorbed by the extrapolation of the ionization current measured for a null distance between the electrodes. This camera is used for dosimetry of external beta rays for radiation protection. This paper presents a simulation for evaluating the functioning of an extrapolation chamber type 23392 of PTW, using the MCNPX Monte Carlo method. In the simulation, the fluence in the air collector cavity of the chamber was obtained. The influence of the materials that compose the camera on its response against beta radiation beam was also analysed. A comparison of the contribution of primary and secondary radiation was performed. The energy deposition in the air collector cavity for different depths was calculated. The component with the higher energy deposition is the Polymethyl methacrylate block. The energy deposition in the air collector cavity for chamber depth 2500 μm is greater with a value of 9.708E-07 MeV. The fluence in the air collector cavity decreases with depth. It's value is 1.758E-04 1/cm 2 for chamber depth 500 μm. The values reported are for individual electron and photon histories. The graphics of simulated parameters are presented in the paper. (Author)

  1. Thinner plantar fascia predicts decreased pain after extracorporeal shock wave therapy.

    Science.gov (United States)

    Liang, Huey-Wen; Wang, Tyng-Guey; Chen, Wen-Shiang; Hou, Sheng-Mou

    2007-07-01

    Increased plantar fascia thickness is common with chronic plantar fasciitis, and reduction of the thickness after extracorporeal shock wave therapy or steroid injection has been reported. We hypothesized a decrease of plantar fascia thickness was associated with pain reduction after extracorporeal shock wave therapy. Fifty-three eligible patients with 78 symptomatic feet were randomly treated with piezoelectric-type extracorporeal shock wave therapy of two intensity levels (0.12 and 0.56 mJ/mm2). Two thousand shock waves for three consecutive sessions were applied at weekly intervals. A visual analog scale for pain, the Foot Function Index, the Short Form-36 Health Survey, and ultrasonographic measurement of plantar fascia thickness were evaluated at baseline and 3 and 6 months after treatment. We analyzed the association between pain level and plantar fascia thickness with generalized estimating equation analysis and adjusted for demographic and treatment-related variables. Patients with thinner plantar fascia experienced less pain after treatment; high-intensity treatment and regular exercise were associated with lower pain level. The overall success rates were 63% and 60% at the 3- and 6-month followups. High- and low-intensity treatments were associated with similar improvements in pain and function. Receiving high-intensity treatment, although associated with less pain at followup, did not provide a higher success rate.

  2. CESAR: conventional ventilatory support vs extracorporeal membrane oxygenation for severe adult respiratory failure.

    Science.gov (United States)

    Peek, Giles J; Clemens, Felicity; Elbourne, Diana; Firmin, Richard; Hardy, Pollyanna; Hibbert, Clare; Killer, Hilliary; Mugford, Miranda; Thalanany, Mariamma; Tiruvoipati, Ravin; Truesdale, Ann; Wilson, Andrew

    2006-12-23

    An estimated 350 adults develop severe, but potentially reversible respiratory failure in the UK annually. Current management uses intermittent positive pressure ventilation, but barotrauma, volutrauma and oxygen toxicity can prevent lung recovery. An alternative treatment, extracorporeal membrane oxygenation, uses cardio-pulmonary bypass technology to temporarily provide gas exchange, allowing ventilator settings to be reduced. While extracorporeal membrane oxygenation is proven to result in improved outcome when compared to conventional ventilation in neonates with severe respiratory failure, there is currently no good evidence from randomised controlled trials to compare these managements for important clinical outcomes in adults, although evidence from case series is promising. The aim of the randomised controlled trial of Conventional ventilatory support vs extracorporeal membrane oxygenation for severe adult respiratory failure (CESAR) is to assess whether, for patients with severe, but potentially reversible, respiratory failure, extracorporeal membrane oxygenation will increase the rate of survival without severe disability ('confined to bed' and 'unable to wash or dress') by six months post-randomisation, and be cost effective from the viewpoints of the NHS and society, compared to conventional ventilatory support. Following assent from a relative, adults (18-65 years) with severe, but potentially reversible, respiratory failure (Murray score >/= 3.0 or hypercapnea with pH service will minimise by type of conventional treatment centre, age, duration of high pressure ventilation, hypoxia/hypercapnea, diagnosis and number of organs failed, to ensure balance in key prognostic variables. Extracorporeal membrane oxygenation will not be available for patients meeting entry criteria outside the trial. 180 patients will be recruited to have 80% power to be able to detect a one third reduction in the primary outcome from 65% at 5% level of statistical significance

  3. Aging of plumes from emission sources based on chamber simulation

    Science.gov (United States)

    Wang, X.; Deng, W.; Fang, Z.; Bernard, F.; Zhang, Y.; Yu, J.; Mellouki, A.; George, C.

    2017-12-01

    Study on atmospheric aging of plumes from emission sources is essential to understand their contribution to both secondary and primary pollutants occurring in the ambient air. Here we directly introduced vehicle exhaust, biomass burning plume, industrial solvents and cooking plumes into a smog chamber with 30 m3 fluorinated ethylene propylene (FEP) Teflon film reactor housed in a temperature-controlled enclosure, for characterizing primarily emitted air pollutants and for investigating secondarily formed products during photo-oxidation. Moreover, we also initiated study on the formation of secondary aerosols when gasoline vehicle exhaust is mixed with typical coal combustion pollutant SO2 or typical agricultural-related pollutant NH3. Formation of secondary organic aerosols (SOA) from typical solvent toluene was also investigated in ambient air matrix in comparison with purified air matrix. Main findings include: 1) Except for exhaust from idling gasoline vehicles, traditional precursor volatile organic compounds could only explain a very small fraction of SOA formed from vehicle exhaust, biomass burning or cooking plumes, suggesting knowledge gap in SOA precursors; 2) There is the need to re-think vehicle emission standards with a combined primary and/or secondary contribution of vehicle exhaust to PM2.5 or other secondary pollutants such as ozone; 3) When mixed with SO2, the gasoline vehicle exhaust revealed an increase of SOA production factor by 60-200% and meanwhile SO2 oxidation rates increased about a factor of 2.7; when the aged gasoline vehicle exhaust were mixing with NH3, both particle number and mass concentrations were increasing explosively. These phenomenons implied the complex interaction during aging of co-existing source emissions. 4) For typical combination of "tolune+SO2+NOx", when compared to chamber simulation with purified air as matrix, both SOA formation and SO2 oxidation were greatly enhanced under ambient air matrix, and the enhancement

  4. Successful Use of Extracorporeal Life Support after Double Traumatic Tracheobronchial Injury in a Patient with Severe Acute Asthma

    Directory of Open Access Journals (Sweden)

    Xavier Valette

    2011-01-01

    Full Text Available We report the case of an asthmatic patient with blunt trachea and left main bronchus injuries who developed acute severe asthma after surgical repair. Despite medical treatment and ventilatory support, asthma persisted with high airway pressures and severe respiratory acidosis. We proposed venovenous extracorporeal life support for CO2 removal which allowed arterial blood gas normalization and airway pressures decrease. Extracorporeal life support was removed on day five after medical treatment of acute severe asthma. So we report the successful use of extracorporeal life support for operated double blunt tracheobronchial injury with acute severe asthma.

  5. Comparison of OH reactivity measurements in the atmospheric simulation chamber SAPHIR

    Science.gov (United States)

    Fuchs, Hendrik; Novelli, Anna; Rolletter, Michael; Hofzumahaus, Andreas; Pfannerstill, Eva Y.; Kessel, Stephan; Edtbauer, Achim; Williams, Jonathan; Michoud, Vincent; Dusanter, Sebastien; Locoge, Nadine; Zannoni, Nora; Gros, Valerie; Truong, Francois; Sarda-Esteve, Roland; Cryer, Danny R.; Brumby, Charlotte A.; Whalley, Lisa K.; Stone, Daniel; Seakins, Paul W.; Heard, Dwayne E.; Schoemaecker, Coralie; Blocquet, Marion; Coudert, Sebastien; Batut, Sebastien; Fittschen, Christa; Thames, Alexander B.; Brune, William H.; Ernest, Cheryl; Harder, Hartwig; Muller, Jennifer B. A.; Elste, Thomas; Kubistin, Dagmar; Andres, Stefanie; Bohn, Birger; Hohaus, Thorsten; Holland, Frank; Li, Xin; Rohrer, Franz; Kiendler-Scharr, Astrid; Tillmann, Ralf; Wegener, Robert; Yu, Zhujun; Zou, Qi; Wahner, Andreas

    2017-10-01

    Hydroxyl (OH) radical reactivity (kOH) has been measured for 18 years with different measurement techniques. In order to compare the performances of instruments deployed in the field, two campaigns were conducted performing experiments in the atmospheric simulation chamber SAPHIR at Forschungszentrum Jülich in October 2015 and April 2016. Chemical conditions were chosen either to be representative of the atmosphere or to test potential limitations of instruments. All types of instruments that are currently used for atmospheric measurements were used in one of the two campaigns. The results of these campaigns demonstrate that OH reactivity can be accurately measured for a wide range of atmospherically relevant chemical conditions (e.g. water vapour, nitrogen oxides, various organic compounds) by all instruments. The precision of the measurements (limit of detection CRM) has a higher limit of detection of 2 s-1 at a time resolution of 10 to 15 min. The performances of the instruments were systematically tested by stepwise increasing, for example, the concentrations of carbon monoxide (CO), water vapour or nitric oxide (NO). In further experiments, mixtures of organic reactants were injected into the chamber to simulate urban and forested environments. Overall, the results show that the instruments are capable of measuring OH reactivity in the presence of CO, alkanes, alkenes and aromatic compounds. The transmission efficiency in Teflon inlet lines could have introduced systematic errors in measurements for low-volatile organic compounds in some instruments. CRM instruments exhibited a larger scatter in the data compared to the other instruments. The largest differences to reference measurements or to calculated reactivity were observed by CRM instruments in the presence of terpenes and oxygenated organic compounds (mixing ratio of OH reactants were up to 10 ppbv). In some of these experiments, only a small fraction of the reactivity is detected. The accuracy of CRM

  6. Geant4 simulation of ion chambers response to {sup 60}Co spectrum of LNMRI/IRD Shepherd 81-14D Radiator

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz Filho, P.P.; Silva, C.N.M. da, E-mail: queiroz@ird.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    The National Ionizing Radiation Metrology Laboratory of the Radioprotection and Dosimetry Institute (LNMRI / IRD) has recently acquired a Shepherd 81-14D Radiator. In this work we simulate, using Geant4, the behavior with the inverse square law radiation of the distance for 3 models of PTW spherical chambers used in radioprotection, a relevant information to planning the measurements. We did the corrections for the attenuation and scattering in the air for each distance, where we used the {sup 60}Co spectrum simulated previously. (author)

  7. Study on the Temperature Separation Phenomenon in a Vortex Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Ye, A Ran; Guang, Zhang; Kim, Heuy Dong [Andong National University, Andong (Korea, Republic of)

    2014-09-15

    A vortex chamber is a simple device that separates compressed gas into a high-temperature stream and a low-temperature stream. It is increasing in popularity as a next-generation heat exchanger, but the flow physics associated with it is not yet well understood. In the present study, both experimental and numerical analyses were performed to investigate the temperature separation phenomenon inside the vortex chamber. Static pressures and temperatures were measured using high-sensitivity pressure transducers and thermocouples, respectively. Computational fluid dynamics was applied to simulate 3D unsteady compressible flows. The simulation results showed that the temperature separation is strongly dependent on the diameter of the vortex chamber and the supply pressure at the inlet ports, where the latter is closely related to the viscous work. The previous concept of a pressure gradient wave may not be a reasoning for temperature separation phenomenon inside the vortex chamber.

  8. Crystalline heterogeneities and instabilities in thermally convecting magma chamber

    Science.gov (United States)

    Culha, C.; Suckale, J.; Qin, Z.

    2016-12-01

    A volcanic vent can supply different densities of crystals over an eruption time period. This has been seen in Hawai'i's Kilauea Iki 1959 eruption; however it is not common for all Kilauea or basaltic eruptions. We ask the question: Under what conditions can homogenous magma chamber cultivate crystalline heterogeneities? In some laboratory experiments and numerical simulations, a horizontal variation is observed. The region where crystals reside is identified as a retention zone: convection velocity balances settling velocity. Simulations and experiments that observe retention zones assume crystals do not alter the convection in the fluid. However, a comparison of experiments and simulations of convecting magma with crystals suggest that large crystal volume densities and crystal sizes alter fluid flow considerably. We introduce a computational method that fully resolves the crystalline phase. To simulate basaltic magma chambers in thermal convection, we built a numerical solver of the Navier-Stoke's equation, continuity equation, and energy equation. The modeled magma is assumed to be a viscous, incompressible fluid with a liquid and solid phase. Crystals are spherical, rigid bodies. We create Rayleigh-Taylor instability through a cool top layer and hot bottom layer and update magma density while keeping crystal temperature and size constant. Our method provides a detailed picture of magma chambers, which we compare to other models and experiments to identify when and how crystals alter magma chamber convection. Alterations include stratification, differential settling and instabilities. These characteristics are dependent on viscosity, convection vigor, crystal volume density and crystal characteristics. We reveal that a volumetric crystal density variation may occur over an eruption time period, if right conditions are met to form stratifications and instabilities in magma chambers. These conditions are realistic for Kilauea Iki's 1959 eruption.

  9. Proton beam monitor chamber calibration

    International Nuclear Information System (INIS)

    Gomà, C; Meer, D; Safai, S; Lorentini, S

    2014-01-01

    The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences—of the order of 3%—were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth—i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers—rather than cylindrical chambers—for the reference dosimetry of pseudo-monoenergetic proton beams. (paper)

  10. Radiation Protection Practices of Staff during Extra-Corporeal Shock ...

    African Journals Online (AJOL)

    Methodology: Some members of staff who were present when the extra-corporeal shock wave lithotripsy (ESWL) was used in the hospital at Okada were interviewed between November 2002 and August 2003. Radiology records of the hospital were studied. Literature search involved available publication on the procedure ...

  11. Survival and ice nucleation activity of bacteria as aerosols in a cloud simulation chamber

    Science.gov (United States)

    Amato, P.; Joly, M.; Schaupp, C.; Attard, E.; Möhler, O.; Morris, C. E.; Brunet, Y.; Delort, A.-M.

    2015-06-01

    The residence time of bacterial cells in the atmosphere is predictable by numerical models. However, estimations of their aerial dispersion as living entities are limited by a lack of information concerning survival rates and behavior in relation to atmospheric water. Here we investigate the viability and ice nucleation (IN) activity of typical atmospheric ice nucleation active bacteria (Pseudomonas syringae and P. fluorescens) when airborne in a cloud simulation chamber (AIDA, Karlsruhe, Germany). Cell suspensions were sprayed into the chamber and aerosol samples were collected by impingement at designated times over a total duration of up to 18 h, and at some occasions after dissipation of a cloud formed by depressurization. Aerosol concentration was monitored simultaneously by online instruments. The cultivability of airborne cells decreased exponentially over time with a half-life time of 250 ± 30 min (about 3.5 to 4.5 h). In contrast, IN activity remained unchanged for several hours after aerosolization, demonstrating that IN activity was maintained after cell death. Interestingly, the relative abundance of IN active cells still airborne in the chamber was strongly decreased after cloud formation and dissipation. This illustrates the preferential precipitation of IN active cells by wet processes. Our results indicate that from 106 cells aerosolized from a surface, one would survive the average duration of its atmospheric journey estimated at 3.4 days. Statistically, this corresponds to the emission of 1 cell that achieves dissemination every ~ 33 min m-2 of cultivated crops fields, a strong source of airborne bacteria. Based on the observed survival rates, depending on wind speed, the trajectory endpoint could be situated several hundreds to thousands of kilometers from the emission source. These results should improve the representation of the aerial dissemination of bacteria in numeric models.

  12. Extended normothermic extracorporeal perfusion of isolated human liver after warm ischaemia: a preliminary report.

    Science.gov (United States)

    Bellomo, Rinaldo; Marino, Bruno; Starkey, Graeme; Fink, Michael; Wang, Bao Zhong; Eastwood, Glenn M; Peck, Leah; Young, Helen; Houston, Shane; Skene, Alison; Opdam, Helen; Jones, Robert

    2014-09-01

    Donation after circulatory death (DCD) livers are at markedly increased risk of primary graft dysfunction and biliary tract ischaemia. Normothermic extracorporeal liver perfusion (NELP) may increase the ability to transplant DCD livers and may allow their use for artificial extracorporeal liver support of patients with fulminant liver failure. We conducted two proof-of-concept experiments using human livers after DCD to assess the feasibility and functional efficacy of NELP over an extended period. We applied extracorporeal membrane oxygenation, parenteral nutrition, separate hepatic artery and portal vein perfusion and physiological perfusion pressures to two livers obtained after DCD. We achieved NELP and evidence of liver function (bile production, paracetamol removal and maintenance of normal lactate levels) in both livers; one for 24 hours and the other for 43 hours. Histological examination showed areas of patchy ischaemia but preserved biliary ducts and canaliculi. Our experiments justify further investigations of the feasibility and efficacy of extended DCD liver preservation by ex-vivo perfusion.

  13. Extracorporeal membrane oxygenation after intravenous injection of paraffin oil

    DEFF Research Database (Denmark)

    Pasgaard, Thomas; Huynh, Anh-Nhi Thi; Gjedsted, Jakob

    2016-01-01

    We present a rare cause of acute respiratory distress syndrome (ARDS) due to an accidental intravascular injection of paraffin oil. While there is no specific therapy, we decided to support the patient with veno-venous extracorporeal membrane oxygenation (V-V ECMO) to allow the ARDS to resolve. A...

  14. INVESTIGATION OF THE HUMIDITY EFFECT ON THE FAC-IR-300 IONIZATION CHAMBER RESPONSE.

    Science.gov (United States)

    Mohammadi, Seyed Mostafa; Tavakoli-Anbaran, Hossein

    2018-02-01

    The free-air ionization chamber is communicating with the ambient air, therefore, the atmospheric parameters such as temperature, pressure and humidity effect on the ionization chamber performance. The free-air ionization chamber, entitled as FAC-IR-300, that design at the Atomic Energy Organization of Iran, AEOI, is required the atmospheric correction factors for correct the chamber reading. In this article, the effect of humidity on the ionization chamber response was investigated. For this reason, was introduced the humidity correction factor, kh. In this article, the Monte Carlo simulation was used to determine the kh factor. The simulation results show in relative humidities between 30% to 80%, the kh factor is equal 0.9970 at 20°C and 0.9975 at 22°C. From the simulation results, at low energy the energy dependence of the kh factor is significant and with increasing energy this dependence is negligible. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Hematological complications in children subjected to extracorporeal membrane oxygenation.

    Science.gov (United States)

    Santiago, M J; Gómez, C; Magaña, I; Muñoz, V; Saiz, P; Sánchez, A; López-Herce, J

    2018-03-29

    To analyze the hematological complications and need for transfusions in children receiving extracorporeal life support (ECLS). A retrospective study was carried out. A pediatric intensive care unit. Children under 18 years of age treated with ECLS between September 2006 and November 2015. None. Patient and ECLS characteristics, anticoagulation, hematological and coagulation parameters, transfusions and clinical course. A total of 100 patients (94 with heart disease) with a median age of 11 months were studied. Seventy-six patients presented bleeding. The most frequent bleeding point being the mediastinum and 39 patients required revision surgery. In the first 3days, 97% of the patients required blood transfusion (34.4ml/kg per day), 94% platelets (21.1ml/kg per day) and 90% plasma (26.6ml/kg per day). Patients who were in the postoperative period, those who were bleeding at the start of ECLS, those requiring revision surgery, those who could not suspend extracorporeal circulation, and those subjected to transthoracic cannulation required a greater volume of transfusions than the rest of the patients. Thromboembolism occurred in 14 patients and hemolysis in 33 patients. Mortality among the children who were bleeding at the start of ECLS (57.6%) was significantly higher than in the rest of the patients (37.5%) (P=0.048). Children treated with ECLS present high blood product needs. The main factors related to transfusions were postoperative period, bleeding at the start of ECLS, revision surgery, transthoracic cannulation, and the impossibility of suspending extracorporeal circulation. Children with bleeding suffered greater mortality than the rest of the patients. Copyright © 2018 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  16. Management of retained encrusted urethral catheter with extracorporeal shockwave lithotripsy

    Directory of Open Access Journals (Sweden)

    Sameh Anwar Kunzman

    2002-01-01

    Full Text Available We report a case of non-deflating heavily encrusted Foley catheter successfully removed by extracorporeal shockwave lithotripsy (ESWL. To our knowledge this is the first case of using ESWL to remove encrusted foley catheter retained in the bladder.

  17. Lung transplantation for idiopathic pulmonary arterial hypertension on intraoperative and postoperatively prolonged extracorporeal membrane oxygenation provides optimally controlled reperfusion and excellent outcome.

    Science.gov (United States)

    Moser, Bernhard; Jaksch, Peter; Taghavi, Shahrokh; Muraközy, Gabriella; Lang, Georg; Hager, Helmut; Krenn, Claus; Roth, Georg; Faybik, Peter; Bacher, Andreas; Aigner, Clemens; Matilla, José R; Hoetzenecker, Konrad; Hacker, Philipp; Lang, Irene; Klepetko, Walter

    2018-01-01

    Lung transplantation for idiopathic pulmonary arterial hypertension has the highest reported postoperative mortality of all indications. Reasons lie in the complexity of treatment of these patients and the frequent occurrence of postoperative left ventricular failure. Transplantation on intraoperative extracorporeal membrane oxygenation support instead of cardiopulmonary bypass and even more the prolongation of extracorporeal membrane oxygenation into the postoperative period helps to overcome these problems. We reviewed our experience with this concept. All patients undergoing bilateral lung transplantation for idiopathic pulmonary arterial hypertension on intraoperative extracorporeal membrane oxygenation with or without prophylactic extracorporeal membrane oxygenation prolongation into the postoperative period between January 2000 and December 2014 were retrospectively analysed. Forty-one patients entered the study. Venoarterial extracorporeal membrane oxygenation support was prolonged into the postoperative period for a median of 2.5 days (range 1-40). Ninety-day, 1-, 3- and 5-year survival rates for the patient collective were 92.7%, 90.2%, 87.4% and 87.4%, respectively. When compared with 31 patients with idiopathic pulmonary arterial hypertension transplanted in the same period of time without prolongation of extracorporeal membrane oxygenation into the postoperative period, the results compared favourably (83.9%, 77.4%, 77.4%, and 77.4%; P = 0.189). Furthermore, these results are among the best results ever reported for this particularly difficult patient population. Bilateral lung transplantation for idiopathic pulmonary arterial hypertension with intraoperative venoarterial extracorporeal membrane oxygenation support seems to provide superior outcome compared with the results reported about the use of cardiopulmonary bypass. Prophylactic prolongation of venoarterial extracorporeal membrane oxygenation into the early postoperative period provides

  18. Nitric oxide : An ally in extracorporeal circulation?

    OpenAIRE

    Melki, Vilyam

    2016-01-01

    Many complications associated with heart surgery are due to the negative effects of extracorporeal circulation (ECC). Some of these complications may be attributed to ECC-induced activation of inflammation and coagulation pathways. The inflammatory reaction may be caused by the interaction of blood components with air and the artificial surfaces of the ECC, from substances produced due to ischaemia-reperfusion injury of the heart and lungs, and from increased release of endotoxin from ischemi...

  19. Extracorporeal irradiation for malignant bone tumors

    International Nuclear Information System (INIS)

    Hong, Angela; Stevens, Graham; Stalley, Paul; Pendlebury, Susan; Ahern, Verity; Ralston, Anna; Estoesta, Edgar; Barrett, Ian

    2001-01-01

    Purpose: Extracorporeal irradiation (ECI) has been used selectively in the management of primary malignant bone tumors since 1996. We report our techniques for ECI and the short-term oncologic and orthopedic outcomes. Methods and Materials: Sixteen patients with primary malignant bone tumors were treated with ECI from 1996 to 2000. The median age was 14 years. The histologic diagnoses were Ewing's sarcoma (11), osteosarcoma (4) and chondrosarcoma (1). The treated sites were femur (7), tibia (4), humerus (2), ilium (2), and sacrum (1). Following induction chemotherapy in Ewing's sarcomas and osteosarcoma, en bloc resection of the tumor and tumor-bearing bone was performed. A single dose of 50 Gy was delivered to the bone extracorporeally using either a linear accelerator (9 cases) or a blood product irradiator (7 cases). The orthopedic outcome was recorded using a standard functional scale. Results: At a median follow-up of 19.5 months, there were no cases of local recurrence or graft failure. One patient required amputation due to chronic osteomyelitis. For the 10 patients with follow-up greater than 18 months, the functional outcomes were graded good to excellent. Conclusion: The short-term oncologic and orthopedic results are encouraging and suggest that ECI provides a good alternative for reconstruction in limb conservative surgery in selected patients. This technique should only be used in a multidisciplinary setting, where careful follow-up is available to assess the long-term outcomes

  20. Cellulite and extracorporeal Shockwave therapy (CelluShock-2009 - a Randomized Trial

    Directory of Open Access Journals (Sweden)

    Joest Beatrice

    2010-10-01

    Full Text Available Abstract Background Cellulite is a widespread problem involving females' buttocks and thighs based on the female specific anatomy. Given the higher number of fat cells stored in female fatty tissue in contrast to males, and the aging process of connective tissue leads to an imbalance between lipogenesis and lipolysis with subsequent large fat cells bulging the skin. In addition, microcirculatory changes have been suggested, however remain largely unknown in a controlled clinical setting. We hypothesize that the combination of extracorporeal shockwave and a daily gluteal muscle strength program is superior to the gluteal muscle strength program alone in cellulite. Methods/Design Study design: Randomized-controlled trial. IRB approval was granted at Hannover Medical School, Germany on May 22, 2009. For allocation of participants, a 1:1 ratio randomization was performed using opaque envelopes for the concealment of allocation. Reporting: according to CONSORT 2010. Eligible patients were females aged 18 or over and 65 or younger with cellulite with documented cellulite 1°-4° according to the Nürnberger score. Exclusion criteria were suspected or evident pregnancy, no cellulite, no informed consent or age under 18 years or above 65 years. Patients were recruited by advertisements in local regional newspapers and via the Internet. Analysis: Intention-to-treat. Outcome parameters: a Photonumeric severity scale, b Nürnberger Score, c circumference measurements, d capillary blood flow, e tissue oxygen saturation, f postcapillary venous blood flow. Intervention group: Six sessions of extracorporeal focused shock wave for six sessions (2000 impulses, 0,25 mJ/m2 every 1-2 weeks at both gluteal and thigh regions plus a specific gluteal strength exercise training. Control group: Six sessions of sham extracorporeal focused shock wave for six sessions (2000 impulses, 0,01 mJ/m2 every 1-2 weeks at both gluteal and thigh regions plus a specific gluteal

  1. Characterization of an extrapolation chamber for low-energy X-rays: Experimental and Monte Carlo preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Lucio P., E-mail: lpneves@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil); Silva, Eric A.B., E-mail: ebrito@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil); Perini, Ana P., E-mail: aperini@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil); Maidana, Nora L., E-mail: nmaidana@if.usp.br [Universidade de Sao Paulo, Instituto de Fisica, Travessa R 187, 05508-900 Sao Paulo, SP (Brazil); Caldas, Linda V.E., E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil)

    2012-07-15

    The extrapolation chamber is a parallel-plate ionization chamber that allows variation of its air-cavity volume. In this work, an experimental study and MCNP-4C Monte Carlo code simulations of an ionization chamber designed and constructed at the Calibration Laboratory at IPEN to be used as a secondary dosimetry standard for low-energy X-rays are reported. The results obtained were within the international recommendations, and the simulations showed that the components of the extrapolation chamber may influence its response up to 11.0%. - Highlights: Black-Right-Pointing-Pointer A homemade extrapolation chamber was studied experimentally and with Monte Carlo. Black-Right-Pointing-Pointer It was characterized as a secondary dosimetry standard, for low energy X-rays. Black-Right-Pointing-Pointer Several characterization tests were performed and the results were satisfactory. Black-Right-Pointing-Pointer Simulation showed that its components may influence the response up to 11.0%. Black-Right-Pointing-Pointer This chamber may be used as a secondary standard at our laboratory.

  2. paediatric ureteric calculi: in-situ extracorporeal shock wave lithotripsy

    African Journals Online (AJOL)

    Objective To evaluate prospectively the efficacy of in-situ extracorporeal shock wave lithotripsy (ESWL) in the treatment of ureteric calculi in the paediatric age group. Patients and Methods Twenty children (aged 2.2 16 years) with 22 ureteric stones were evaluated and treated with in-situ ESWL using the Dornier S lithotripter ...

  3. Use of Extracorporeal Membrane Oxygenation in a Fulminant Course of Amniotic Fluid Embolism Syndrome Immediately after Cesarean Delivery

    Directory of Open Access Journals (Sweden)

    Jae Ha Lee

    2016-08-01

    Full Text Available Amniotic fluid embolism is rare but is one of the most catastrophic complications in the peripartum period. This syndrome is caused by a maternal anaphylactic reaction to the introduction of fetal material into the pulmonary circulation. When amniotic fluid embolism is suspected, the immediate application of extracorporeal mechanical circulatory support such as veno-arterial extracorporeal membrane oxygenation (ECMO or cardiopulmonary bypass should be considered. Without the application of extracorporeal mechanical circulatory support, medical supportive care might not be sufficient to maintain cardiopulmonary stabilization in severe cases of amniotic fluid embolism. In this report, we present the case of a 36-year-old pregnant woman who developed an amniotic fluid embolism immediately after a cesarean section. Her catastrophic event started with the sudden onset of severe hypoxia, followed by circulatory collapse within 8 minutes. The veno-arterial mode of extracorporeal membrane oxygenation was initiated immediately. She was successfully resuscitated but with impaired cognitive function. Thus, urgent ECMO should be considered when amniotic fluid embolism syndrome is suspected in patients presenting acute cardiopulmonary collapse.

  4. Pre-launch simulation experiment of microwave-ionosphere nonlinear interaction rocket experiment in the space plasma chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kaya, N. (Kobe University, Kobe, Japan); Tsutsui, M. (Kyoto University, Uji, Japan); Matsumoto, H. (Kyoto University, Kyoto, Japan)

    1980-09-01

    A pre-flight test experiment of a microwave-ionosphere nonlinear interaction rocket experiment (MINIX) has been carried out in a space plasma simulation chamber. Though the first rocket experiment ended up in failure because of a high voltage trouble, interesting results are observed in the pre-flight experiment. A significant microwave heating of plasma up to 300% temperature increase is observed. Strong excitations of plasma waves by the transmitted microwaves in the VLF and HF range are observed as well. These microwave effects may have to be taken into account in solar power satellite projects in the future.

  5. The effects of extracorporeal shock wave therapy on stroke patients with plantar fasciitis

    Science.gov (United States)

    Kim, Tae Gon; Bae, Sea Hyun; Kim, Gye Yeop; Kim, Kyung Yoon

    2015-01-01

    [Purpose] The purpose of this research was to analyze the efficacy of extracorporeal shock wave therapy for the treatment of stroke patients with plantar fasciitis. [Subjects and Methods] This study included 10 stroke patients diagnosed with plantar fasciitis who were administered 3 sessions of extracorporeal shock wave therapy per week. After the last session, they performed stretching exercises for their Achilles tendon and plantar fascia for 30 min/day, 5 times a week for 6 months. The following parameters were measured and compared prior to therapy, 6 weeks after therapy, and 6 months after therapy: thickness of the plantar fascia, using an ultrasonic imaging system; degree of spasticity, using a muscle tension measuring instrument; degree of pain, using the visual analogue scale; and gait ability, using the Functional Gait Assessment. [Results] Decreased plantar fascia thickness, spasticity, and pain and increased gait ability were noted after therapy. These changes were significantly greater at 6 months after therapy than at 6 weeks after therapy. [Conclusion] These results indicated that extracorporeal shock wave therapy reduced tension in the plantar fascia, relieving pain and improving gait ability in stroke patients. PMID:25729207

  6. Blood leukocyte responses to extracorporeal circulation. 2. Medium term extracorporeal circulation without and with extracorporeal irradiation in normal and splenectomized dogs

    Energy Technology Data Exchange (ETDEWEB)

    Szemere, P.; Fliedner, T.M. (Ulm Univ. (Germany, F.R.). Abt. Klinische Physiologie)

    1983-01-01

    Medium term (6-8 h) extracorporeal irradiation without and with irradiation of blood was performed in normal and splenectomized dogs to reveal the changes of blood leukocytes including CFU-C. A regular but transitory decrease of granulocytes and a longer lasting diminution of lymphocytes in the blood were observed. The CFU-C level became and mostly remained very low during the procedure. Splenectomy did not influence significantly the changes of peripheral leukocyte counts. No marked difference of leukocytes was seen in the blood samples taken from the arterial or venous side of the shunt or even from the cubital vein. Also, the irradiation did not produce any difference in the alterations of blood cell counts compared to those without irradiation. The possible explanations of these results are discussed.

  7. Computational evaluation of a pencil ionization chamber in a standard diagnostic radiology beam

    International Nuclear Information System (INIS)

    Mendonca, Dalila Souza Costa; Neves, Lucio Pereira; Perini, Ana Paula; Belinato, Walmir

    2016-01-01

    In this work a pencil ionization chamber was evaluated. This evaluation consisted in the determination of the influence of the ionization chamber components in its response. For this purpose, the Monte Carlo simulations and the spectrum of the standard diagnostic radiology beam (RQR5) were utilized. The results obtained, showed that the influence of the ionization chamber components presented no significant influence on the chamber response. Therefore, this ionization chamber is a good alternative for dosimetry in diagnostic radiology. (author)

  8. Centrifugal pumps and hemolysis in pediatric extracorporeal membrane oxygenation (ECMO) patients: An analysis of Extracorporeal Life Support Organization (ELSO) registry data.

    Science.gov (United States)

    O'Brien, Ciaran; Monteagudo, Julie; Schad, Christine; Cheung, Eva; Middlesworth, William

    2017-06-01

    It is currently unclear whether centrifugal pumps cause more hemolysis than roller pumps in extracorporeal membrane oxygenation (ECMO) circuits. The aim of this study was to help answer that question in pediatric patients. A limited deidentified data set was extracted from the international multicenter Extracorporeal Life Support Organization (ELSO) registry comprising all reported ECMO runs for patients 18years or younger between 2010 and 2015. Logistic regression was used to evaluate a possible association between hemolysis and pump type, controlling for patient demographics, circuit factors, and complications. 14,776 ECMO runs for 14,026 patients had pump type recorded. Centrifugal pumps were employed in 60.4% of ECMO circuits. Hemolysis was a reported complication for 1272 (14%) centrifugal pump runs and for 291 (5%) roller pump runs. 1755 (20%) centrifugal pump runs reported kidney injury as compared to 797 (14%) roller pump runs. In the full logistic regression, the odds of hemolysis were significantly greater for runs using centrifugal pumps (OR 3.3, 95% CI 2.9-3.8, ppumps was associated with increased rates of hemolysis, hyperbilirubinemia, and kidney injury. Retrospective cohort study. Level III. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Pediatric extracorporeal shock wave lithotripsy: Predicting successful outcomes.

    Science.gov (United States)

    McAdams, Sean; Shukla, Aseem R

    2010-10-01

    Extracorporeal shock wave lithotripsy (ESWL) is currently a first-line procedure of most upper urinary tract stones ionizing radiation, perhaps utilizing advancements in ultrasound and magnetic resonance imaging. This report provides a review of the current literature evaluating the patient attributes and stone factors that may be predictive of successful ESWL outcomes along with reviewing the role of pre-operative imaging and considerations for patient safety.

  10. 2D convolution kernels of ionization chambers used for photon-beam dosimetry in magnetic fields: the advantage of small over large chamber dimensions

    Science.gov (United States)

    Khee Looe, Hui; Delfs, Björn; Poppinga, Daniela; Harder, Dietrich; Poppe, Björn

    2018-04-01

    This study aims at developing an optimization strategy for photon-beam dosimetry in magnetic fields using ionization chambers. Similar to the familiar case in the absence of a magnetic field, detectors should be selected under the criterion that their measured 2D signal profiles M(x,y) approximate the absorbed dose to water profiles D(x,y) as closely as possible. Since the conversion of D(x,y) into M(x,y) is known as the convolution with the ‘lateral dose response function’ K(x-ξ, y-η) of the detector, the ideal detector would be characterized by a vanishing magnetic field dependence of this convolution kernel (Looe et al 2017b Phys. Med. Biol. 62 5131–48). The idea of the present study is to find out, by Monte Carlo simulation of two commercial ionization chambers of different size, whether the smaller chamber dimensions would be instrumental to approach this aim. As typical examples, the lateral dose response functions in the presence and absence of a magnetic field have been Monte-Carlo modeled for the new commercial ionization chambers PTW 31021 (‘Semiflex 3D’, internal radius 2.4 mm) and PTW 31022 (‘PinPoint 3D’, internal radius 1.45 mm), which are both available with calibration factors. The Monte-Carlo model of the ionization chambers has been adjusted to account for the presence of the non-collecting part of the air volume near the guard ring. The Monte-Carlo results allow a comparison between the widths of the magnetic field dependent photon fluence response function K M(x-ξ, y-η) and of the lateral dose response function K(x-ξ, y-η) of the two chambers with the width of the dose deposition kernel K D(x-ξ, y-η). The simulated dose and chamber signal profiles show that in small photon fields and in the presence of a 1.5 T field the distortion of the chamber signal profile compared with the true dose profile is weakest for the smaller chamber. The dose responses of both chambers at large field size are shown to be altered by not

  11. Extracorporeal gas exchange with the DeltaStream rotary blood pump in experimental lung injury.

    Science.gov (United States)

    Dembinski, Rolf; Kopp, Rüdger; Henzler, Dietrich; Hochhausen, Nadine; Oslender, Nicole; Max, Martin; Rossaint, Rolf; Kuhlen, Ralf

    2003-06-01

    In most severe cases of the acute respiratory distress syndrome, veno-venous extracorporeal membrane oxygenation (ECMO) can be used to facilitate gas exchange. However, the clinical use is limited due to the size and the concomitant risk of severe adverse events of conventionally-used centrifugal blood pumps with high extracorporeal blood volumes. The DeltaStream blood pump is a small-sized rotary blood pump that may reduce extracorporeal blood volume, foreign surfaces, contact activation of the coagulation system, and blood trauma. The aim of the present study was to test the safety and efficacy of the DeltaStream pump for ECMO in animals with normal lung function and experimental acute lung injury (ALI). Therefore, veno-venous ECMO was performed for 6 hours in mechanically ventilated pigs with normal lung function (n=6) and with ALI induced by repeated lung lavage (n=6) with a blood flow of 30% of the cardiac output. Gas flow with a FiO2 of 1.0 was set to equal blood flow. With a mean activated clotting time of 121 +/- 22 s, no circulatory impairment or thrombus formation was revealed during ECMO. Furthermore, free plasma Hb did not increase. In controls, hemodynamics and gas exchange remained unchanged. In animals with ALI, hemodynamics remained stable and gas transfer across the extracorporeal oxygenators was optimal, but only in 2 animals was a marked increase in PaO2 observed. CO2 removal was efficacious in all animals. We concluded that the DeltaStream blood pump may be used for veno-venous ECMO without major blood damage or hemodynamic impairment.

  12. A novel approach to the management of critically ill neonatal Ebstein's anomaly: Veno-venous extracorporeal membrane oxygenation to promote right ventricular recovery.

    Science.gov (United States)

    Bauser-Heaton, Holly; Nguyen, Charles; Tacy, Theresa; Axelrod, David

    2015-01-01

    This is the first report of the use of veno-venous extracorporeal membrane oxygenation in a neonate with severe Ebstein's anomaly. The report suggests the use of veno-venous extracorporeal membrane oxygenation in the immediate neonatal period may be a useful therapy in severe Ebstein's anomaly. By providing adequate oxygenation independent of the patient's native pulmonary blood flow, veno-venous extracorporeal membrane oxygenation allows the pulmonary vascular resistance to decrease and may promote right ventricular recovery.

  13. Testing fireproof materials in a combustion chamber

    Directory of Open Access Journals (Sweden)

    Kulhavy Petr

    2017-01-01

    Full Text Available This article deals with a prototype concept, real experiment and numerical simulation of a combustion chamber, designed for testing fire resistance some new insulating composite materials. This concept of a device used for testing various materials, providing possibility of monitoring temperatures during controlled gas combustion. As a fuel for the combustion process propane butane mixture has been used and also several kinds of burners with various conditions of inlet air (forced, free and fuel flows were tested. The tested samples were layered sandwich materials based on various materials or foams, used as fillers in fire shutters. The temperature distribution was measured by using thermocouples. A simulation of whole concept of experimental chamber has been carried out as the non-premixed combustion process in the commercial final volume sw Pyrosim. The result was to design chamber with a construction suitable, according to the international standards, achieve the required values (temperature in time. Model of the combustion based on a stoichiometric defined mixture of gas and the tested layered samples showed good conformity with experimental results – i.e. thermal distribution inside and heat release rate that has gone through the sample.

  14. Extracorporeal Circulation Causes Release of Neutrophil Gelatinase-Associated Lipocalin (NGAL

    Directory of Open Access Journals (Sweden)

    Per Jönsson

    1999-01-01

    Full Text Available Extracorporeal circulation (ECC used during cardiac surgery causes activation of several inflammatory systems. These events are not fully understood but are responsible for complications during the immediate postoperative period. Neutrophil gelatinase-associated lipocalin (NGAL, a member of the expanding lipocalin family, has recently been described as an inflammatory protein. In this study, the release of NGAL into the circulation in 41 patients undergoing heart surgery with ECC was evaluated. A 4- to 5-fold elevation of the concentration of NGAL in plasma was observed during the immediate postoperative course with a rapid elimination during the first postoperative day. Four patients undergoing lung surgery (without ECC were also studied. The plasma concentration of NGAL only increased with a factor of 1.1-2.2 over the operation. We conclude that NGAL is released into the circulation during heart surgery, probably as a result of the inflammatory activation of leukocytes initiated by the extracorporeal circulation.

  15. Evaluation of furosemide regimens in neonates treated with extracorporeal membrane oxygenation

    NARCIS (Netherlands)

    M.M.J. van der Vorst (Maria); E.D. Wildschut (Enno); R.J.M. Houmes (Robert Jan); S.J. Gischler (Saskia); J.E. Kist-Van Holthe (Joana); J. Burggraaf (Jacobus); A.J. van der Heijden (Bert); D. Tibboel (Dick)

    2006-01-01

    textabstractIntroduction: Loop diuretics are the most frequently used diuretics in patients treated with extracorporeal membrane oxygenation (ECMO). In patients after cardiopulmonary bypass (CPB) surgery, the use of continuous furosemide infusion is increasingly documented. Because ECMO and CPB are

  16. Kidney changes after extracorporeal shock wave lithotripsy

    International Nuclear Information System (INIS)

    Yoshioka, Hiroyasu; Shindo, Hiroshi; Mabuchi, Nobuhisa; Kawakami, Akira; Fujii, Koichi; Hamada, Tatsumi; Ishida, Osamu; Umekawa, Toru; Kohri, Kenjiro

    1991-01-01

    MRI was performed before and after extracorporeal shock wave lithotripsy (ESWL) to determine the effects of ESWL on the kidney and perinephric tissues. Of the 40 kidneys studied, 24 showed one or more changes on MRI: loss of the corticomedullary junction (n=15), subcapsular fluid (n=14), subcapsular hematoma (n=1), thickening of bridging septa (n=8), high intensity area in the muscle (n=8). These relatively subtle changes detected on MRI may not be apparent with other imaging techniques. (author)

  17. Extracorporeal therapy in sepsis: are we there yet?

    Science.gov (United States)

    Shukla, Ashutosh M

    2012-02-01

    The role of extracorporeal therapies (ECTs) in sepsis is unclear and is a strongly debated topic in critical-care medicine. Unfortunately, much of this debate arises because we lack a clear understanding of what defines the stage and severity of the disease, and the pivotal pathophysiological events dictating outcomes. In the absence of this knowledge, ECTs remain among a large group of therapies with high promise but unproven efficacy.

  18. Development of a parallel plate ion chamber for radiation protection level

    International Nuclear Information System (INIS)

    Bottaro, Marcio; Landi, Mauricio; Moralles, Mauricio

    2011-01-01

    A new parallel plate vented ion chamber is proposed in this paper. The application of this chamber was primarily intended to the measurement of stray radiation in interventional procedures, but the energy response of about 2.6%, which was obtained in the first prototype, on the range from 40 to 150 kV using ISO 4037-1 narrow qualities, provided the possibility of a wide modality application on radiation protection. Primary studies with Maxwell 2D electromagnetic field simulator revealed an optimized model regarding effective volume and saturation voltage levels, which conferred to the ion chamber a dual entrance window feature. The development of this ion chamber has the main contribution of Monte Carlo calculations as a support tool to the establishment of the effective volume of the chamber and determination of the best materials for housing mounting and conductive elements, such as guard rings, electrode, and windows. Even the composition of the conductive layers, which would be neglected due to their very small thicknesses (about 35 μm), had important influence on the results and could be better understood with Monte Carlo N-Particle Transport Code System (MCNP) simulations. (author)

  19. Cyclosporine and Extracorporeal Photopheresis are Equipotent in Treating Severe Atopic Dermatitis

    DEFF Research Database (Denmark)

    Koppelhus, Uffe; Poulsen, Johan; Grunnet, Niels

    2014-01-01

    BACKGROUND: Severe atopic dermatitis (AD) is a recurrent and debilitating disease often requiring systemic immunosuppressive treatment. The efficacy of cyclosporine A (CsA) is well proven but potential side effects are concerning. Several reports point at extracorporeal photopheresis (ECP) as an ...

  20. Extracorporeal shock wave lithotripsy 25 years later: complications and their prevention

    NARCIS (Netherlands)

    Skolarikos, Andreas; Alivizatos, Gerasimos; de la Rosette, Jean

    2006-01-01

    OBJECTIVE: We review the pathophysiology and possible prevention measures of complications after extracorporeal shock wave lithotripsy (ESWL). METHODS: A literature search was performed with the Medline database on ESWL between 1980 and 2004. RESULTS: ESWL application has been intuitively connected

  1. Fission chamber simulator for data acquisition performance tests

    International Nuclear Information System (INIS)

    Batyunin, A.V.; Vorobev, V.A.; Obudovsky, S.Yu.; Kaschuck, Yu.A.; Shvikin, S.A.

    2013-06-01

    Divertor neutron flux monitor (DNFM) is a diagnostic system to be used for measurement of the total neutron yield and fusion power in the experimental fusion tokamak-reactor ITER. The diagnostic consists of the 18 fission chambers (FC), front-end electronics and data acquisition system to process, collect and archive data. The system should provide neutron flux measurements in dynamic range 7 orders of magnitude with a time resolution 1 ms and an error less 10%. (authors)

  2. Lung contusion and cavitation with exudative plural effusion following extracorporeal shock wave lithotripsy in an adult: a case report

    Directory of Open Access Journals (Sweden)

    Nouri-Majalan Nader

    2010-08-01

    Full Text Available Abstract Introduction Among the complications of extracorporeal shock wave lithotripsy are perinephric bleeding and hypertension. Case presentation We describe the case of a 31-year-old Asian man with an unusual case of hemoptysis and lung contusion and cavitation with exudative plural effusion due to pulmonary trauma following false positioning of extracorporeal shock wave lithotripsy. Differential diagnoses included pneumonia and pulmonary emboli, but these diagnoses were ruled out by the uniformly negative results of a lung perfusion scan, Doppler ultrasound, and culture of bronchoalveolar lavage and plural effusion, and because our patient showed spontaneous improvement. Conclusions False positioning of extracorporeal shock wave lithotripsy can cause lung trauma presenting as pulmonary contusion and cavitation with plural effusion.

  3. Search for the best timing strategy in high-precision drift chambers

    International Nuclear Information System (INIS)

    Va'vra, J.

    1983-06-01

    Computer simulated drift chamber pulses are used to investigate various possible timing strategies in the drift chambers. In particular, the leading edge, the multiple threshold and the flash ADC timing methods are compared. Although the presented method is general for any drift geometry, we concentrate our discussion on the jet chambers where the drift velocity is about 3 to 5 cm/μsec and the individual ionization clusters are not resolved due to a finite speed of our electronics

  4. Steady 3D Numerical Simulation of the Evaporator and Compensation Chamber of a Loop Heat Pipe

    Directory of Open Access Journals (Sweden)

    A. V. Nedayvozov

    2017-01-01

    Full Text Available The paper presents results of a steady three-dimensional numerical simulation of a flat evaporator and compensation chamber (CC of a loop heat pipe (LHP and describes a procedure of the thermal state calculation of the evaporator and the compensation chamber.The LHP is an efficient heat transfer device operating on the principle of evaporation-condensation cycle. It is successfully used in space technology and also to cool the heat-stressed components of electronic devices and computer equipment. The authors carried out a numerical study of the influence of the condensate pipeline length, immersed in water, on the thermal state of the evaporator and the compensation chamber.  The paper shows the influence of the mass forces field on the calculation results. Presents all the numerical studies carried out by the authors for a brass flat evaporator with a thermal load of 80 W. Water is used as a LHP heat-transfer fluid. Fields of temperature, pressure and velocity are presented for each design option.Based on the calculation results, the authors came to the following conclusions:Influence of the mass forces field for the LHP of this type is significant and leads to arising water vortex flow in the condensate pipeline and CC, thereby mixing and equalizing the water temperature in the CC and in the porous element, reducing the maximum temperature of the porous element;The increasing section length of the condensate pipeline in the CC leads to increasing velocity of the heat-transfer fluid in the CC and in the porous element, decreasing mixing zone of the condensate in the CC, and increasing temperature non-uniformity of the porous element.

  5. Modelling auto ignition of hydrogen in a jet ignition pre-chamber

    Energy Technology Data Exchange (ETDEWEB)

    Boretti, Alberto A. [School of Science and Engineering, University of Ballarat, PO Box 663, Ballarat, Victoria 3353 (Australia)

    2010-04-15

    Spark-less jet ignition pre-chambers are enablers of high efficiencies and load control by quantity of fuel injected when coupled with direct injection of main chamber fuel, thus permitting always lean burn bulk stratified combustion. Towards the end of the compression stroke, a small quantity of hydrogen is injected within the pre-chamber, where it mixes with the air entering from the main chamber. Combustion of the air and fuel mixture then starts within the pre-chamber because of the high temperature of the hot glow plug, and then jets of partially combusted hot gases enter the main chamber igniting there in the bulk, over multiple ignition points, lean stratified mixtures of air and fuel. The paper describes the operation of the spark-less jet ignition pre-chamber coupling CFD and CAE engine simulations to allow component selection and engine performance evaluation. (author)

  6. Dynamic consideration of smog chamber experiments

    Science.gov (United States)

    Chuang, Wayne K.; Donahue, Neil M.

    2017-08-01

    Recent studies of the α-pinene + ozone reaction that address particle nucleation show relatively high molar yields of highly oxidized multifunctional organic molecules with very low saturation concentrations that can form and grow new particles on their own. However, numerous smog-chamber experiments addressing secondary organic aerosol (SOA) mass yields, interpreted via equilibrium partitioning theory, suggest that the vast majority of SOA from α-pinene is semivolatile. We explore this paradox by employing a dynamic volatility basis set (VBS) model that reproduces the new-particle growth rates observed in the CLOUD experiment at CERN and then modeling SOA mass yield experiments conducted at Carnegie Mellon University (CMU). We find that the base-case simulations do overpredict observed SOA mass but by much less than an equilibrium analysis would suggest; this is because delayed condensation of vapors suppresses the apparent mass yields early in the chamber experiments. We further find that a second VBS model featuring substantial oligomerization of semivolatile monomers can match the CLOUD growth rates with substantially lower SOA mass yields; this is because the lighter monomers have a higher velocity and thus a higher condensation rate for a given mass concentration. The oligomerization simulations are a closer match to the CMU experiments than the base-case simulations, though they overpredict the observations somewhat. However, we also find that if the chemical conditions in CLOUD and the CMU chamber were identical, substantial nucleation would have occurred in the CMU experiments when in fact none occurred. This suggests that the chemical mechanisms differed in the two experiments, perhaps because the high oxidation rates in the SOA formation experiments led to rapid termination of peroxy radical chemistry.

  7. In Vivo Testing of Extracorporeal Membrane Ventilators: iLA-Activve Versus Prototype I-Lung.

    Science.gov (United States)

    Kischkel, Sabine; Bergt, Stefan; Brock, Beate; von Grönheim, Johan; Herbst, Anne; Epping, Marc-Jonas; Matheis, Georg; Novosel, Esther; Schneider, Joerg; Warnke, Philipp; Podbielski, Andreas; Roesner, Jan P; Lelkes, Peter I; Vollmar, Brigitte

    A side-by-side comparison of the decarboxylation efficacy of two pump-driven venovenous extracorporeal lung assist devices, i.e., a first prototype of the new miniaturized ambulatory extracorporeal membrane ventilator, I-lung versus the commercial system iLA-activve for more than a period of 72 hours in a large animal model. Fifteen German Landrace pigs were anesthetized and underwent mechanical hypoventilation to induce severe hypercapnia. Decarboxylation was accomplished by either the I-lung or the iLA-activve via a double lumen catheter in the jugular vein. Sham-operated pigs were not connected to extracorporeal devices. Cardiovascular, respiratory, and metabolic parameters were continuously monitored, combined with periodic arterial blood sampling for subsequent clinical blood diagnostics, such as gas exchange, hemolysis, coagulation parameters, and cytokine profiles. At the termination of the studies, lung tissue was harvested and examined histologically for pulmonary morphology and leukocyte tissue infiltration. Both extracorporeal devices showed high and comparable efficacy with respect to carbon dioxide elimination for more than 72 hours and were not associated with either bleeding events or clotting disorders. Pigs of both groups showed cardiovascular and hemodynamic stability without marked differences to sham-operated animals. Groups also did not differ in terms of inflammatory and metabolic parameters. We established a preclinical in vivo porcine model for comparative long-term testing of I-lung and iLA-activve. The I-lung prototype proved to be safe and feasible, providing adequate decarboxylation without any adverse events. Once translated into the clinical treatment, the new miniaturized and transportable I-lung device might represent a promising tool for treating awake and mobilized patients with decompensated pulmonary disorders.

  8. Extracorporeal Detoxification in Victims with Severe Concomitant Injury

    Directory of Open Access Journals (Sweden)

    S. Ye. Khoroshilov

    2009-01-01

    Full Text Available Objective: to improve the results of victims with massive crushes of soft tissues in severe concomitant injury (SCI, by applying extracorporeal detoxification techniques as soon as possible. Subjects and methods. The results of examination and treatment were studied in 41 victims with SCI treated at the N. N. Burdenko Main Military Clinical Hospital in 2006 to 2008. In the early posttraumatic period (on days 1—3, all the victims (n=41 were divided into 2 groups. Group 1 victims (n=19 underwent hemodiafiltration (HDF with replacement at 35 ml/kg/hr; Group 2 (n=22 had plasmapheresis. Results. Early HDF applied to Group 1 victims could achieve 32, 44, and 37% reductions in the elevated levels creatine phosphokinase, myoglobin, and middle-sized molecules, respectively. In Group 2, plasmapheresis showed a lower effect (19, 25, and 26% reductions. Furthermore, there was a decrease in total protein in Group 1, which was absent in Group 2. Conclusion. The timely use of extracorporeal detoxification techniques in victims with massive crushes of soft tissues in the early posttraumatic period prevents the development of fatal complications of SCI, at the same time HDF is more effective and safe than plasmapheresis. Key words: severe concomitant injury, rhabdomyolysis, myoglobin, plasmapheresis, hemodiafiltration.

  9. Extracorporeal shockwave therapy for patellar tendinopathy : a review of the literature

    NARCIS (Netherlands)

    van Leeuwen, M. T.; Zwerver, J.; van den Akker-Scheek, I.

    Background and purpose: Extracorporeal shockwave therapy (EWST) has become a popular treatment for patellar tendinopathy. The purpose of this review was to study the effectiveness of ESWT treatment for patellar tendinopathy; to draft guidelines for an effective treatment protocol of ESWT treatment;

  10. Nosocomial transmission of Cupriavidus pauculus during extracorporeal membrane oxygenation.

    Science.gov (United States)

    Stovall, S H; Wisdom, C; McKamie, W; Ware, W; Dedman, H; Fiser, R T

    2010-01-01

    Patients undergoing extracorporeal membrane oxygenation (ECMO) are at increased risk of infection. We present the first known report of nosocomial infection with Cupriavidus pauculus attributable to contamination from ECMO equipment and describe the measures taken to halt subsequent infections. A cluster of infections in ECMO patients should prompt team members to consider contamination of equipment with environmental pathogens as a possible cause.

  11. Fabrication of Free Air Well Type Ionization Chamber and Calculational Assessment and Measurement of Its Operational Characteristics

    Directory of Open Access Journals (Sweden)

    Koroush Arbabi

    2007-12-01

    Full Text Available Introduction: Well type ionization chamber is a measuring device which is used to determine the activity of brachytherapy sources. The chamber has a cylindrical volume in which a cylindrical tube is mounted in the middle of the chamber. For the measurements, the brachytherapy sources are transferred to the middle of the tube. Materials and Methods: For designing the well type chamber, the measurement principals of well type chambers were considered and MCNP-4C code as a calculation tool was used. The designed chamber was simulated and the response of the chamber was evaluated. In this investigation, the chamber operational parameters such as operating voltage, leakage current, reproducibility, reference measuring point, recombination and polarization factors as well as response stability for 137Cs, 57Co and 241Am sources were studied. Results: The chamber leakage currents at the operating voltage in comparison to the chamber response for the measurement of the above mentioned sources were negligible. The responses of the fabricated chamber for these sources are reproducible and its reference measurement position for these sources was obtained at 6 cm from the bottom of the chamber. The recombination factor for the well type chamber was negligible and the polarization factor is close to 1. Therefore, these two factors were not considered in the measurements. The reproducibility of the measurements in different intervals shows the stability of the chamber response for each source. Also the results of the chamber current measurement in term of source strength were compared to the response of the simulated chamber for different source positions and energy ranges of the used sources. Discussion and Conclusion: The results show that the measurement of the reference positions for each source in the simulated and fabricated chamber is quite in a good agreement. Regarding the reliable operational properties of the fabricated chamber, this chamber can be

  12. [Extracorporeal ventriculoatrial shunt with the use of one-way ball valve].

    Science.gov (United States)

    Kubo, Shigeki; Takimoto, Hiroshi; Hosoi, Kazuki; Toyota, Shingo; Takakura, Shuji; Hayashi, Yasuhiro; Ueno, Masato; Morisako, Toshitaka; Karasawa, Jun; Ninaga, Hideo; Yoshimine, Toshiki

    2002-04-01

    We developed a simple system of an "extracorporeal" ventriculoatrial (VA) shunt using a one-way ball valve (Acty valve II, Kaneka Medix) to release the patient from postoperative constraint during the ventricular drainage. The system is constructed in such a way that the ventricular drainage tube is connected to the central venous catheter via a one-way valve. The CSF is regulated by using the valve and is diverted into the systemic circulation as in the conventional ventriculoatrial shunt. After 2 or 3 weeks of CSF diversion through the extracorporeal VA shunt, a ventriculoperitoneal shunt is placed if hydrocephalus is apparent by temporary occlusion of the system. We applied this system to 4 patients with hydrocephalus, and we found it useful and free from adverse effects. The patient was freed from physical constraint involved in conventional ventricular drainage and an effective program of early rehabilitation was able to be started.

  13. Numerical analysis of whole-body cryotherapy chamber design improvement

    Science.gov (United States)

    Yerezhep, D.; Tukmakova, A. S.; Fomin, V. E.; Masalimov, A.; Asach, A. V.; Novotelnova, A. V.; Baranov, A. Yu

    2018-05-01

    Whole body cryotherapy is a state-of-the-art method that uses cold for treatment and prevention of diseases. The process implies the impact of cryogenic gas on a human body that implements in a special cryochamber. The temperature field in the chamber is of great importance since local integument over-cooling may occur. Numerical simulation of WBC has been carried out. Chamber design modification has been proposed in order to increase the uniformity of the internal temperature field. The results have been compared with the ones obtained for a standard chamber design. The value of temperature gradient formed in the chamber containing curved wall with certain height has been decreased almost twice in comparison with the results obtained for the standard design. The modification proposed may increase both safety and comfort of cryotherapy.

  14. Extracorporeal shock wave therapy (ESWT) in urology

    DEFF Research Database (Denmark)

    Fojecki, Grzegorz Lukasz; Thiessen, Stefan; Osther, Palle Jörn Sloth

    2017-01-01

    PURPOSE: The objective was to evaluate high-level evidence studies of extracorporeal shock wave therapy (ESWT) for urological disorders. METHODS: We included randomized controlled trials reporting outcomes of ESWT in urology. Literature search on trials published in English using EMBASE, Medline...... deviation and plaque size were observed. Four studies on erectile dysfunction (ED) including 337 participants were included. Using International Index of Erectile Function (IIEF-EF) and erectile hardness scale (EHS) data suggested a significant positive effect of ESWT in phosphodiesterase-5 inhibitor (PDE-5...

  15. A novel approach to the management of critically ill neonatal Ebstein′s anomaly: Veno-venous extracorporeal membrane oxygenation to promote right ventricular recovery

    Directory of Open Access Journals (Sweden)

    Holly Bauser-Heaton

    2015-01-01

    Full Text Available This is the first report of the use of veno-venous extracorporeal membrane oxygenation in a neonate with severe Ebstein′s anomaly. The report suggests the use of veno-venous extracorporeal membrane oxygenation in the immediate neonatal period may be a useful therapy in severe Ebstein′s anomaly. By providing adequate oxygenation independent of the patient′s native pulmonary blood flow, veno-venous extracorporeal membrane oxygenation allows the pulmonary vascular resistance to decrease and may promote right ventricular recovery.

  16. Comparison of OH reactivity measurements in the atmospheric simulation chamber SAPHIR

    Directory of Open Access Journals (Sweden)

    H. Fuchs

    2017-10-01

    Full Text Available Hydroxyl (OH radical reactivity (kOH has been measured for 18 years with different measurement techniques. In order to compare the performances of instruments deployed in the field, two campaigns were conducted performing experiments in the atmospheric simulation chamber SAPHIR at Forschungszentrum Jülich in October 2015 and April 2016. Chemical conditions were chosen either to be representative of the atmosphere or to test potential limitations of instruments. All types of instruments that are currently used for atmospheric measurements were used in one of the two campaigns. The results of these campaigns demonstrate that OH reactivity can be accurately measured for a wide range of atmospherically relevant chemical conditions (e.g. water vapour, nitrogen oxides, various organic compounds by all instruments. The precision of the measurements (limit of detection  < 1 s−1 at a time resolution of 30 s to a few minutes is higher for instruments directly detecting hydroxyl radicals, whereas the indirect comparative reactivity method (CRM has a higher limit of detection of 2 s−1 at a time resolution of 10 to 15 min. The performances of the instruments were systematically tested by stepwise increasing, for example, the concentrations of carbon monoxide (CO, water vapour or nitric oxide (NO. In further experiments, mixtures of organic reactants were injected into the chamber to simulate urban and forested environments. Overall, the results show that the instruments are capable of measuring OH reactivity in the presence of CO, alkanes, alkenes and aromatic compounds. The transmission efficiency in Teflon inlet lines could have introduced systematic errors in measurements for low-volatile organic compounds in some instruments. CRM instruments exhibited a larger scatter in the data compared to the other instruments. The largest differences to reference measurements or to calculated reactivity were observed by CRM instruments in

  17. Response to 'Comments on 'Ionization chamber volume determination and quality assurance using micro-CT imaging''

    International Nuclear Information System (INIS)

    McNiven, Andrea L; Holdsworth, David W; Battista, Jerry J; Umoh, Joseph; Kron, Tomas

    2009-01-01

    Air ionization chamber dosimetry plays a crucial role in international dose calibration for the radiotherapy clinical environment. Micro-CT images of ion chambers can play an important role in quality assurance of these devices by detecting internal geometry, materials and defects non-invasively, as we demonstrated (McNiven et al 2008 Phys. Med. Biol. 53 5029-43). We also suggested that electric-field simulation based upon these accurate chamber-specific 3D images rather than manufacturer blueprints could be valuable in assessing ionometric sensitivity. As recently performed by Ross et al these electric field simulations play a vital role in understanding key components that contribute to the chamber sensitive volume and ionization calibration coefficients. (letter to the editor)

  18. Finite element modeling of acoustic wave propagation and energy deposition in bone during extracorporeal shock wave treatment

    Science.gov (United States)

    Wang, Xiaofeng; Matula, Thomas J.; Ma, Yong; Liu, Zheng; Tu, Juan; Guo, Xiasheng; Zhang, Dong

    2013-06-01

    It is well known that extracorporeal shock wave treatment is capable of providing a non-surgical and relatively pain free alternative treatment modality for patients suffering from musculoskeletal disorders but do not respond well to conservative treatments. The major objective of current work is to investigate how the shock wave (SW) field would change if a bony structure exists in the path of the acoustic wave. Here, a model of finite element method (FEM) was developed based on linear elasticity and acoustic propagation equations to examine SW propagation and deflection near a mimic musculoskeletal bone. High-speed photography experiments were performed to record cavitation bubbles generated in SW field with the presence of mimic bone. By comparing experimental and simulated results, the effectiveness of FEM model could be verified and strain energy distributions in the bone were also predicted according to numerical simulations. The results show that (1) the SW field will be deflected with the presence of bony structure and varying deflection angles can be observed as the bone shifted up in the z-direction relative to SW geometric focus (F2 focus); (2) SW deflection angels predicted by the FEM model agree well with experimental results obtained from high-speed photographs; and (3) temporal evolutions of strain energy distribution in the bone can also be evaluated based on FEM model, with varied vertical distance between F2 focus and intended target point on the bone surface. The present studies indicate that, by combining MRI/CT scans and FEM modeling work, it is possible to better understand SW propagation characteristics and energy deposition in musculoskeletal structure during extracorporeal shock wave treatment, which is important for standardizing the treatment dosage, optimizing treatment protocols, and even providing patient-specific treatment guidance in clinic.

  19. Modelling of a general purpose irradiation chamber using a Monte Carlo particle transport code

    International Nuclear Information System (INIS)

    Dhiyauddin Ahmad Fauzi; Sheik, F.O.A.; Nurul Fadzlin Hasbullah

    2013-01-01

    Full-text: The aim of this research is to stimulate the effectiveness use of a general purpose irradiation chamber to contain pure neutron particles obtained from a research reactor. The secondary neutron and gamma particles dose discharge from the chamber layers will be used as a platform to estimate the safe dimension of the chamber. The chamber, made up of layers of lead (Pb), shielding, polyethylene (PE), moderator and commercial grade aluminium (Al) cladding is proposed for the use of interacting samples with pure neutron particles in a nuclear reactor environment. The estimation was accomplished through simulation based on general Monte Carlo N-Particle transport code using Los Alamos MCNPX software. Simulations were performed on the model of the chamber subjected to high neutron flux radiation and its gamma radiation product. The model of neutron particle used is based on the neutron source found in PUSPATI TRIGA MARK II research reactor which holds a maximum flux value of 1 x 10 12 neutron/ cm 2 s. The expected outcomes of this research are zero gamma dose in the core of the chamber and neutron dose rate of less than 10 μSv/ day discharge from the chamber system. (author)

  20. ExtraCorporeal Membrane Oxygenation in Newborns. Implications for Brain and Lung.

    NARCIS (Netherlands)

    Heyst, A.F.J. van

    2004-01-01

    Extracorporeal membrane oxygenation (ECMO) is a rescue treatment for newborns with severe respiratory insufficiency. In veno-arterial ECMO, venous blood is drained from the right atrium, oxygenated in an artificial lung and reinfused in the aorta. For vascular access the right internal jugular vein

  1. Role of extracorporeal shock wave lithotripsy in hepato-biliary-pancreatic surgery

    NARCIS (Netherlands)

    R.L. van der Hul (René); P.W. Plaisier; O.T. Terpstra (Onno); H.A. Bruining (Hajo)

    1993-01-01

    textabstractSince the early 1980s extracorporeal shock wave lithotripsy (ESWL) has partially replaced major operative procedures in various fields of surgery. In the interest of the patient, it is important to determine the exact role of ESWL in surgery. Comparing our own prospectively followed

  2. Extracorporeal life support for cardiac arrest in a 13-year-old girl caused by Wolff-Parkinson-White syndrome.

    Science.gov (United States)

    Song, Kyoung Hwan; Lee, Byung Kook; Jeung, Kyung Woon; Lee, Dong Hun

    2015-10-01

    Generally, Wolff-Parkinson-White (WPW) syndrome presents good prognosis. However, several case reports demonstrated malignant arrhythmia or sudden cardiac death as WPW syndrome's first presentation. Cardiopulmonary resuscitation using extracorporeal life support is a therapeutic option in refractory cardiac arrest. We present a WPW syndrome patient who had sudden cardiac arrest as the first presentation of the disease and treated it using extracorporeal life support with good neurologic outcome.

  3. Activity measurements of radioactive solutions by liquid scintillation counting and pressurized ionization chambers and Monte Carlo simulations of source-detector systems for metrology

    International Nuclear Information System (INIS)

    Amiot, Marie-Noelle

    2013-01-01

    The research works 'Activity measurements of radioactive solutions by liquid scintillation and pressurized ionization chambers and Monte Carlo simulations of source-detector systems' was presented for the graduation: 'Habilitation a diriger des recherches'. The common thread of both themes liquid scintillation counting and pressurized ionization chambers lies in the improvement of the techniques of radionuclide activity measurement. Metrology of ionization radiation intervenes in numerous domains, in the research, in the industry including the environment and the health, which are subjects of constant concern for the world population these last years. In this big variety of applications answers a large number of radionuclides of diverse disintegration scheme and under varied physical forms. The presented works realized within the National Laboratory Henri Becquerel have for objective to assure detector calibration traceability and to improve the methods of activity measurements within the framework of research projects and development. The improvement of the primary and secondary activity measurement methods consists in perfecting the accuracy of the measurements in particular by a better knowledge of the parameters influencing the detector yield. The works of development dealing with liquid scintillation counting concern mainly the study of the response of liquid scintillators to low energy electrons as well as their linear absorption coefficients using synchrotron radiation. The research works on pressurized ionization chambers consist of the study of their response to photons and electrons by experimental measurements compared to the simulation of the source-detector system using Monte Carlo codes. Besides, the design of a new type of ionization chamber with variable pressure is presented. This new project was developed to guarantee the precision of the amount of activity injected into the patient within the framework of diagnosis examination

  4. Using the method of statistic tests for determining the pressure in the UNC-600 vacuum chamber

    International Nuclear Information System (INIS)

    Kiver, A.M.; Mirzoev, K.G.

    1998-01-01

    The aim of the paper is to simulate the process of pumping-out the UNC-600 vacuum chamber. The simulation is carried out by the Monte-Carlo statistic test method. It is shown that the pressure value in every liner of the chamber may be determined from the pressure in the pump branch pipe, determined by the discharge current of this pump. Therefore, it is possible to precise the working pressure in the ion guide of the UNC-600 vacuum chamber [ru

  5. Mechanisms of lymphocytotoxicity induced by extracorporeal photochemotherapy for cutaneous T cell lymphoma

    International Nuclear Information System (INIS)

    Marks, D.I.; Rockman, S.P.; Oziemski, M.A.; Fox, R.M.

    1990-01-01

    Extracorporeal photochemotherapy is an effective treatment for cutaneous T cell lymphoma but its mode of action is uncertain. The reduction in viability of patients' photoirradiated buffy coat lymphocytes was correlated with a 35% increase in DNA single-strand breaks and marked decreases in cellular ATP and NAD levels (to 58 and 34% of control, respectively) immediately after photoirradiation. Complementary in vitro studies were conducted with normal human peripheral blood lymphocytes using a Therakos ultraviolet A (UVA) light box. UVA light was cytotoxic on its own but was potentiated by 8-methoxysporalen. 3-aminobenzamide, a poly (ADP-ribose) synthetase inhibitor, mitigated the cytotoxic effect of ultraviolet A light in the presence of 8-methoxypsoralen in lymphocytes and reduced the amount of nucleotide depletion they caused. 10 J/cm2 of UVA light in the presence of 300 ng/ml 8-methoxypsoralen increased the poly (ADP-ribose) synthetase activity of peripheral blood lymphocytes. Exposing lymphocytes to deoxycoformycin and deoxyadenosine was found to induce biochemical and physical effects similar to those of photochemotherapy. In summary, we have shown that the lymphocytotoxic effect of extracorporeal photochemotherapy for cutaneous T cell lymphoma is apparently mediated by DNA damage, subsequent poly (ADP-ribosyl)ation and adenine nucleotide depletion. It is not known how the DNA damage and resultant biochemical effects relate to the possible immunological mechanism of extracorporeal photochemotherapy; however, it is possible that its effects can be mimicked by other DNA-damaging agents

  6. Use of minimal invasive extracorporeal circulation in cardiac surgery: principles, definitions and potential benefits. A position paper from the Minimal invasive Extra-Corporeal Technologies international Society (MiECTiS)

    NARCIS (Netherlands)

    Anastasiadis, Kyriakos; Murkin, John; Antonitsis, Polychronis; Bauer, Adrian; Ranucci, Marco; Gygax, Erich; Schaarschmidt, Jan; Fromes, Yves; Philipp, Alois; Eberle, Balthasar; Punjabi, Prakash; Argiriadou, Helena; Kadner, Alexander; Jenni, Hansjoerg; Albrecht, Guenter; van Boven, Wim; Liebold, Andreas; de Somer, Fillip; Hausmann, Harald; Deliopoulos, Apostolos; El-Essawi, Aschraf; Mazzei, Valerio; Biancari, Fausto; Fernandez, Adam; Weerwind, Patrick; Puehler, Thomas; Serrick, Cyril; Waanders, Frans; Gunaydin, Serdar; Ohri, Sunil; Gummert, Jan; Angelini, Gianni; Falk, Volkmar; Carrel, Thierry

    2016-01-01

    Minimal invasive extracorporeal circulation (MiECC) systems have initiated important efforts within science and technology to further improve the biocompatibility of cardiopulmonary bypass components to minimize the adverse effects and improve end-organ protection. The Minimal invasive

  7. Position reconstruction in drift chambers operated with Xe, $CO_{2}$ (15\\%)

    CERN Document Server

    Adler, C; Appelshäuser, H; Bielcikova, J; Blume, C; Braun-Munzinger, P; Bucher, D; Busch, O; Catanescu, V; Ciobanu, M; Daues, H W; Emschermann, D; Fateev, O V; Foka, P; Garabatos, C; Gunji, T; Herrmann, N; Inuzuka, M; Ivanov, M; Kislov, E; Lindenstruth, V; Lippmann, C; Ludolphs, W; Mahmoud, T; Petracek, V; Petrovici, M; Radomski, S; Rusanov, I; Sandoval, A; Santo, R; Schicker, R; Schwarz, K; Simon, R S; Smykov, L P; Soltveit, H K; Stachel, J; Stelzer, H; Tsiledakis, G; Vulpescu, B; Wessels, J P; Windelband, B; Yurevich, V; Zanevsky, Yu; Zaudtke, O

    2005-01-01

    We present measurements of position and angular resolution of drift chambers operated with a Xe, CO2 (15%) mixture. The results are compared to Monte Carlo simulations and important systematic effects - in particular the dispersive nature of the absorption of transition radiation and non-linearities - are discussed. The measurements were carried out with prototype drift chambers of the ALICE Transition Radiation Detector, but our findings can be generalized to other drift chambers with similar geometry, where the electron drift is perpendicular to the wire planes.

  8. Impact of tubing length on hemodynamics in a simulated neonatal extracorporeal life support circuit.

    Science.gov (United States)

    Qiu, Feng; Uluer, Mehmet C; Kunselman, Allen; Clark, J Brian; Myers, John L; Undar, Akif

    2010-11-01

    During extracorporeal life support (ECLS), a large portion of the hemodynamic energy is lost to various components of the circuit. Minimization of this loss in the circuit leads to better vital organ perfusion and decreases the risk of systemic inflammation. In this study, we evaluated the hemodynamic properties of differing lengths of tubing in a simulated neonatal ECLS circuit. The neonatal ECLS circuit used in this study included a Capiox Baby RX05 oxygenator (Terumo Corporation, Tokyo, Japan), a Rotaflow centrifugal pump (MAQUET Cardiopulmonary AG, Hirrlingen, Germany), and a heater and cooler unit. An 8Fr Biomedicus arterial and a 10Fr Biomedicus venous cannula were connected to the pseudopatient. One-fourth inch tubing was used for both the arterial and the venous line. A Hoffman clamp was located upstream from the pseudopatient to maintain a certain patient pressure. Three pressure transducers were placed at different sites: postoxygenator, prearterial cannula, and postarterial cannula. The system was primed with Lactated Ringer's solution; human blood was then added to maintain a hematocrit of 40%. The volume of the pseudopatient was 500mL. We hemodynamically evaluated three circuits with different lengths of tubing: 6, 4, and 2 feet (182.88, 121.92, and 60.96 cm, respectively) for both arterial and venous lines; the priming volumes including all of the components of the circuits were 195, 155, and 115mL, respectively. In each circuit, we measured the pressure drops of the arterial tubing and the arterial cannula, as well as the flow rates at different rpm (1750-3000, 250 intervals) under three patient pressures (40, 60, and 80mm Hg). All the experiments were conducted at 37°C. The pressure drop across the arterial cannula is much larger than that of arterial tubing in all set-ups, especially under high flow rates. Upon cutting the tubing from 6 to 2 feet, the pressure drop of the arterial tubing decreased by half, while the pressure drop of the arterial

  9. Extracorporeal shockwave therapy in the treatment of chronic diabetic foot ulcers

    DEFF Research Database (Denmark)

    Jeppesen, S M; Yderstraede, K B; Rasmussen, B S B

    2016-01-01

    OBJECTIVE: To investigate the efficacy of extracorporeal shockwave therapy (ESWT) on healing chronic diabetic foot ulcers (DFU). METHOD: Patients with chronic DFUs were randomised (1:1) to receive a series of six ESWT treatments over 3 weeks in combination with standard care or standard care alone...

  10. A Neutrophil Phenotype Model for Extracorporeal Treatment of Sepsis.

    Directory of Open Access Journals (Sweden)

    Alexander D Malkin

    2015-10-01

    Full Text Available Neutrophils play a central role in eliminating bacterial pathogens, but may also contribute to end-organ damage in sepsis. Interleukin-8 (IL-8, a key modulator of neutrophil function, signals through neutrophil specific surface receptors CXCR-1 and CXCR-2. In this study a mechanistic computational model was used to evaluate and deploy an extracorporeal sepsis treatment which modulates CXCR-1/2 levels. First, a simplified mechanistic computational model of IL-8 mediated activation of CXCR-1/2 receptors was developed, containing 16 ODEs and 43 parameters. Receptor level dynamics and systemic parameters were coupled with multiple neutrophil phenotypes to generate dynamic populations of activated neutrophils which reduce pathogen load, and/or primed neutrophils which cause adverse tissue damage when misdirected. The mathematical model was calibrated using experimental data from baboons administered a two-hour infusion of E coli and followed for a maximum of 28 days. Ensembles of parameters were generated using a Bayesian parallel tempering approach to produce model fits that could recreate experimental outcomes. Stepwise logistic regression identified seven model parameters as key determinants of mortality. Sensitivity analysis showed that parameters controlling the level of killer cell neutrophils affected the overall systemic damage of individuals. To evaluate rescue strategies and provide probabilistic predictions of their impact on mortality, time of onset, duration, and capture efficacy of an extracorporeal device that modulated neutrophil phenotype were explored. Our findings suggest that interventions aiming to modulate phenotypic composition are time sensitive. When introduced between 3-6 hours of infection for a 72 hour duration, the survivor population increased from 31% to 40-80%. Treatment efficacy quickly diminishes if not introduced within 15 hours of infection. Significant harm is possible with treatment durations ranging from 5

  11. Evaluation of ion chamber dependent correction factors for ionisation chamber dosimetry in proton beams using a Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Palmans, H [Ghent Univ. (Belgium). Dept. of Biomedical Physics; Verhaegen, F

    1995-12-01

    In the last decade, several clinical proton beam therapy facilities have been developed. To satisfy the demand for uniformity in clinical (routine) proton beam dosimetry two dosimetry protocols (ECHED and AAPM) have been published. Both protocols neglect the influence of ion chamber dependent parameters on dose determination in proton beams because of the scatter properties of these beams, although the problem has not been studied thoroughly yet. A comparison between water calorimetry and ionisation chamber dosimetry showed a discrepancy of 2.6% between the former method and ionometry following the ECHED protocol. Possibly, a small part of this difference can be attributed to chamber dependent correction factors. Indications for this possibility are found in ionometry measurements. To allow the simulation of complex geometries with different media necessary for the study of those corrections, an existing proton Monte Carlo code (PTRAN, Berger) has been modified. The original code, that applies Mollire`s multiple scattering theory and Vavilov`s energy straggling theory, calculates depth dose profiles, energy distributions and radial distributions for pencil beams in water. Comparisons with measurements and calculations reported in the literature are done to test the program`s accuracy. Preliminary results of the influence of chamber design and chamber materials on dose to water determination are presented.

  12. Evaluation of ion chamber dependent correction factors for ionisation chamber dosimetry in proton beams using a Monte Carlo method

    International Nuclear Information System (INIS)

    Palmans, H.; Verhaegen, F.

    1995-01-01

    In the last decade, several clinical proton beam therapy facilities have been developed. To satisfy the demand for uniformity in clinical (routine) proton beam dosimetry two dosimetry protocols (ECHED and AAPM) have been published. Both protocols neglect the influence of ion chamber dependent parameters on dose determination in proton beams because of the scatter properties of these beams, although the problem has not been studied thoroughly yet. A comparison between water calorimetry and ionisation chamber dosimetry showed a discrepancy of 2.6% between the former method and ionometry following the ECHED protocol. Possibly, a small part of this difference can be attributed to chamber dependent correction factors. Indications for this possibility are found in ionometry measurements. To allow the simulation of complex geometries with different media necessary for the study of those corrections, an existing proton Monte Carlo code (PTRAN, Berger) has been modified. The original code, that applies Mollire's multiple scattering theory and Vavilov's energy straggling theory, calculates depth dose profiles, energy distributions and radial distributions for pencil beams in water. Comparisons with measurements and calculations reported in the literature are done to test the program's accuracy. Preliminary results of the influence of chamber design and chamber materials on dose to water determination are presented

  13. Deployment and testing of a second prototype expandable surgical chamber in microgravity

    Science.gov (United States)

    Markham, Sanford M.; Rock, John A.

    1991-01-01

    During microgravity exposure, two separate expandable surgical chambers were tested. Both chambers had been modified to fit the microgravity work station without extending over the sides of the table. Both chambers were attached to a portable laminar flow generator which served two purposes: to keep the chambers expanded during use; and to provide an operative area environment free of contamination. During the tests, the chambers were placed on various parts of a total body moulage to simulate management of several types of trauma. The tests consisted of cleansing contusions, debridement of burns, and suturing of lacerations. Also, indigo carmine dye was deliberately injected into the chamber during the tests to determine the ease of cleansing the chamber walls after contamination by escaping fluids. Upon completion of the tests, the expandable surgical chambers were deflated, folded, and placed in a flattened state back into their original containers for storage and later disposal. Results are briefly discussed.

  14. Dynamic consideration of smog chamber experiments

    Directory of Open Access Journals (Sweden)

    W. K. Chuang

    2017-08-01

    Full Text Available Recent studies of the α-pinene + ozone reaction that address particle nucleation show relatively high molar yields of highly oxidized multifunctional organic molecules with very low saturation concentrations that can form and grow new particles on their own. However, numerous smog-chamber experiments addressing secondary organic aerosol (SOA mass yields, interpreted via equilibrium partitioning theory, suggest that the vast majority of SOA from α-pinene is semivolatile. We explore this paradox by employing a dynamic volatility basis set (VBS model that reproduces the new-particle growth rates observed in the CLOUD experiment at CERN and then modeling SOA mass yield experiments conducted at Carnegie Mellon University (CMU. We find that the base-case simulations do overpredict observed SOA mass but by much less than an equilibrium analysis would suggest; this is because delayed condensation of vapors suppresses the apparent mass yields early in the chamber experiments. We further find that a second VBS model featuring substantial oligomerization of semivolatile monomers can match the CLOUD growth rates with substantially lower SOA mass yields; this is because the lighter monomers have a higher velocity and thus a higher condensation rate for a given mass concentration. The oligomerization simulations are a closer match to the CMU experiments than the base-case simulations, though they overpredict the observations somewhat. However, we also find that if the chemical conditions in CLOUD and the CMU chamber were identical, substantial nucleation would have occurred in the CMU experiments when in fact none occurred. This suggests that the chemical mechanisms differed in the two experiments, perhaps because the high oxidation rates in the SOA formation experiments led to rapid termination of peroxy radical chemistry.

  15. Study of Parameters Effect on Hydrodynamics of a Gas-Solid Chamber Experimentally and Numerically

    Directory of Open Access Journals (Sweden)

    Rahimzadeh Hassan

    2012-04-01

    Full Text Available In this research, gas velocity, initial static bed height and particle size effect on hydrodynamics of a non-reactive gas–solid fluidized bed chamber were studied experimentally and computationally. A multi fluid Eulerian model incorporating the kinetic theory for solid particles was applied to simulate the unsteady state behavior of this chamber and momentum exchange coefficients were calculated by using the Syamlal- O’Brien drag functions. Simulation results were compared with the experimental data in order to validate the CFD model. Pressure drops predicted by the simulations at different particle sizes and initial static bed height were in good agreement with experimental measurements at superficial gas velocity higher than the minimum fluidization velocity. Simulation results also indicated that small bubbles were produced at the bottom of the bed. These bubbles collided with each other as they moved upwards forming larger bubbles. Furthermore, this comparison showed that the model can predict hydrodynamic behavior of gas solid fluidized bed chambers reasonably well.

  16. Simulation studies for a high resolution time projection chamber at the international linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Muennich, A.

    2007-03-26

    The International Linear Collider (ILC) is planned to be the next large accelerator. The ILC will be able to perform high precision measurements only possible at the clean environment of electron positron collisions. In order to reach this high accuracy, the requirements for the detector performance are challenging. Several detector concepts are currently under study. The understanding of the detector and its performance will be crucial to extract the desired physics results from the data. To optimise the detector design, simulation studies are needed. Simulation packages like GEANT4 allow to model the detector geometry and simulate the energy deposit in the different materials. However, the detector response taking into account the transportation of the produced charge to the readout devices and the effects ofthe readout electronics cannot be described in detail. These processes in the detector will change the measured position of the energy deposit relative to the point of origin. The determination of this detector response is the task of detailed simulation studies, which have to be carried out for each subdetector. A high resolution Time Projection Chamber (TPC) with gas amplification based on micro pattern gas detectors, is one of the options for the main tracking system at the ILC. In the present thesis a detailed simulation tool to study the performance of a TPC was developed. Its goal is to find the optimal settings to reach an excellent momentum and spatial resolution. After an introduction to the present status of particle physics and the ILC project with special focus on the TPC as central tracker, the simulation framework is presented. The basic simulation methods and implemented processes are introduced. Within this stand-alone simulation framework each electron produced by primary ionisation is transferred through the gas volume and amplified using Gas Electron Multipliers (GEMs). The output format of the simulation is identical to the raw data from a

  17. Ionization chamber

    International Nuclear Information System (INIS)

    Jilbert, P.H.

    1975-01-01

    The invention concerns ionization chambers with particular reference to air-equivalent ionization chambers. In order to ensure that similar chambers have similar sensitivities and responses the surface of the chamber bounding the active volume carries a conducting material, which may be a colloidal graphite, arranged in the form of lines so that the area of the conducting material occupies only a small proportion of the area of said surface. (U.S.)

  18. Roller and Centrifugal Pumps: A Retrospective Comparison of Bleeding Complications in Extracorporeal Membrane Oxygenation.

    Science.gov (United States)

    Halaweish, Ihab; Cole, Adam; Cooley, Elaine; Lynch, William R; Haft, Jonathan W

    2015-01-01

    Centrifugal pumps are increasingly used for extracorporeal membrane oxygenation (ECMO) rather than roller pumps. However, shear forces induced by these types of continuousflow pumps are associated with acquired von Willebrand factor deficiency and bleeding complications. This study was undertaken to compare adverse bleeding complications with the use of centrifugal and roller pumps in patients on prolonged ECMO support. The records of all adult ECMO patients from June 2002 to 2013 were retrospectively reviewed using the University of Michigan Health System database and the Extracorporeal Life Support Organization registry, focusing on patients supported for at least 5 days. Ninety-five ECMO patients met criteria for inclusion (48 roller vs. 47 centrifugal pump). Indications included pulmonary (79%), cardiac (15%), and extracorporeal cardiopulmonary resuscitation (6%), without significant difference between the two groups. Despite lower heparin anticoagulation (10.9 vs. 13.7 IU/kg/hr) with centrifugal pumps, there was a higher incidence of nonsurgical bleeding (gastrointestinal, pulmonary, and neurological) in centrifugal pump patients (26.1 vs. 9.0 events/1,000 patient-days, p = 0.024). In conclusion, in our historical comparison, despite reduced anticoagulation, ECMO support using centrifugal pumps was associated with a higher incidence of nonsurgical bleeding. The mechanisms behind this are multifactorial and require further investigation.

  19. Hemodynamic deterioration during extracorporeal membrane oxygenation weaning in a patient with a total artificial heart.

    Science.gov (United States)

    Hosseinian, Leila; Levin, Matthew A; Fischer, Gregory W; Anyanwu, Anelechi C; Torregrossa, Gianluca; Evans, Adam S

    2015-01-01

    The Total Artificial Heart (Syncardia, Tucson, AZ) is approved for use as a bridge-to-transplant or destination therapy in patients who have irreversible end-stage biventricular heart failure. We present a unique case, in which the inferior vena cava compression by a total artificial heart was initially masked for days by the concurrent placement of an extracorporeal membrane oxygenation cannula. This is the case of a 33-year-old man admitted to our institution with recurrent episodes of ventricular tachycardia requiring emergent total artificial heart and venovenous extracorporeal membrane oxygenation placement. This interesting scenario highlights the importance for critical care physicians to have an understanding of exact anatomical localization of a total artificial heart, extracorporeal membrane oxygenation, and their potential interactions. In total artificial heart patients with hemodynamic compromise or reduced device filling, consideration should always be given to venous inflow compression, particularly in those with smaller body surface area. Transesophageal echocardiogram is a readily available diagnostic tool that must be considered standard of care, not only in the operating room but also in the ICU, when dealing with this complex subpopulation of cardiac patients.

  20. [Renal hematomas after extracorporeal shock-wave lithotripsy (ESWL)].

    Science.gov (United States)

    Pastor Navarro, Héctor; Carrión López, Pedro; Martínez Ruiz, Jesús; Pastor Guzmán, José Ma; Martínez Martín, Mariano; Virseda Rodríguez, Julio A

    2009-03-01

    The use of fragmentation due to shock- waves as a treatment of urinary stone was one of the most important therapeutics findings in the history of urology. It's the first election treatment for most of the calculus at renal and urethral location due to the fact that it is a low invasive treatment and it has a few number of complications, but this method also has a few negative side effects, it can caused a more or less important traumatic lesion at the organs which crosses the shock-waves, including the kidney where it can caused a small contusion or renal hematoma with different resolution and treatment. We reviewed 4815 extracorporeal shock-wave lithotripsy that we performed in our department in which we found six cases with subcapsular and perirenal hematoma which we followed up and treated. After the urological complications (pain, obstruction and infection) the renal and perirenal hematic collections are the most frequent adverse effects of shock-waves used in lithotripsy, these are related to the power of energy used and patient age. Between the years 1992-2007 we performed 4.815 extracorporeal shock-wave lithotripsy finding seven cases of severe hematoma, less then 1%. Treatment of these complications is usually not aggressive though sometimes it is necessary to perform surgical drainage and even nephrectomy.

  1. Investigation of the applicability of a special parallel-plate ionization chamber for x-ray beam dosimetry

    International Nuclear Information System (INIS)

    Perini, Ana P.; Neves, Lucio P.; Caldas, Linda V.E.

    2014-01-01

    Diagnostic x-rays are the greatest source of exposition to ionizing radiation of the population worldwide. In order to obtain accurate and lower-cost dosimeters for quality control assurance of medical x-ray facilities, a special ionization chamber was designed at the Calibration Laboratory of the IPEN, for dosimetry in diagnostic radiology beams. For the chamber characterization some tests were undertaken. Monte Carlo simulations were proposed to evaluate the distribution of the deposited energy in the sensitive volume of the ionization chamber and the collecting electrode effect on the chamber response. According to the obtained results, this special ionization chamber presents potential use for dosimetry of conventional diagnostic radiology beams. - Highlights: • An ionization chamber with a novel design was characterized for x-ray beam dosimetry. • This ionization chamber was evaluated in diagnostic radiology qualities. • The characterization tests results were within the recommended limits. • Monte Carlo simulations were employed to evaluate the design of the dosimeter. • The developed prototype is a good alternative for calibration laboratories and clinics

  2. Endoscopic Resection of Tracheal Tumor in an Elderly Woman Under Extracorporeal Membrane Oxygenation

    Directory of Open Access Journals (Sweden)

    Yi-Ying Chiang

    2011-03-01

    Full Text Available Anesthetic management of patients with difficult airway is challenging, especially in patients who present with near total occlusion of the airway. Tracheal tumors occur more frequently in elderly patients who are more prone to hypoxic injury. Reliable ventilation and oxygenation are mandatory for a safe and sound intervention. Herein, we report on a 71-year-old woman with a large tracheal tumor occluding approximately 90% of the tracheal lumen. Extracorporeal membrane oxygenation under local anesthesia was used during electrocautery resection of the tumor because of the possibility of fatal airway collapse due to the degree of occlusion and location of the tumor. After the tumor had been successfully resected by means of bronchoscopy, an endotracheal tube was inserted, and the patient was weaned from extracorporeal membrane oxygenation.

  3. Influence of chamber misalignment on cased telescoped (CT ammunition accuracy

    Directory of Open Access Journals (Sweden)

    D. Corriveau

    2016-04-01

    Full Text Available As part of a research program, it was desired to better understand the impact of the rotating chamber alignment with the barrel throat on the precision and accuracy of a novel cased telescoped (CT ammunition firing rifle. In order to perform the study, a baseline CT ammunition chamber which was concentric with a Mann barrel bore was manufactured. Additionally, six chambers were manufactured with an offset relative to the barrel bore. These chambers were used to simulate a misaligned chamber relative to the bore axis. Precision and accuracy tests were then performed at 200 m in an indoor range under controlled conditions. For this project, 5.56 mm CT ammunition was used. As the chamber axis offset relative to the gun bore was increased, the mean point of impact was displaced away from the target center. The shift in the impact location is explained by the presence of in-bore yaw which results in lateral throw-off and aerodynamic jump components. The linear theory of ballistics is used to establish a relationship between the chamber misalignment and the resulting projectile mean point of impact for a rifle developed to fire CT ammunition. This relationship allows for the prediction of the mean point of impact given a chamber misalignment.

  4. Development of real-time and quantitative monitoring of thrombus formation in an extracorporeal centrifugal blood pump

    Science.gov (United States)

    Sakota, Daisuke; Fujiwara, Tatsuki; Ohuchi, Katsuhiro; Kuwana, Katsuyuki; Yamazaki, Hiroyuki; Kosaka, Ryo; Maruyama, Osamu

    2018-02-01

    We developed an optical detector of thrombus formed on the pivot bearing of an extracorporeal centrifugal blood pump (MERA HCF-MP23; Senko Medical Instrument Mfg. Co., Ltd., Tokyo, Japan) which is frequently used for long-term extracorporeal circulation support to bridge to an implantable artificial heart, which in turn is used for bridge to heart transplantation in Japan. In this study, we investigated the quantitative performance of the thrombus formation in acute animal experiments. A total of three experiments of extracorporeal left ventricular assist using Japanese specific pathogen-free pigs were conducted. The optical fibers were set in the pump driver unit. The incident light at nearinfrared wavelength aiming at the pivot bearing and the resulting scattered light were guided to respective fibers. The detected signal was analyzed to obtain thrombus formation level (TFL) calculated by a specially developed software. When the increase in TFL was confirmed, the pump was exchanged and the extracorporeal circulation was restarted. The number of pump exchanges were four times at each experiment so a total of twelve pumps were evaluated. 3-dimentional data surrounding the pivot bearing and the adhered thrombus was captured by a 3-dimantional surface measurement system to calculate the thrombus surface area (TSA) formed on the pivot bearing. As a result, the correlation coefficient between TFL and TSA was 0.878. The accuracy of TSA estimated by the optical detector was 3.6+/-2.3 mm2. This was small enough to not have the pump exchanged in clinical judgement. The developed detector would be useful for optimal anti-coagulation management.

  5. Glove box chamber

    International Nuclear Information System (INIS)

    Cox, M.E.; Cox, M.E.

    1975-01-01

    An environmental chamber is described which enables an operator's hands to have direct access within the chamber without compromising a special atmosphere within such chamber. A pair of sleeves of a flexible material are sealed to the chamber around associated access apertures and project outwardly from such chamber. Each aperture is closed by a door which is openable from within the sleeve associated therewith so that upon an operator inserting his hand and arm through the sleeve, the operator can open the door to have access to the interior of the chamber. A container which is selectively separable from the remainder of the chamber is also provided to allow objects to be transferred from the chamber without such objects having to pass through the ambient atmosphere. An antechamber permitting objects to be passed directly into the chamber from the ambient atmosphere is included. (auth)

  6. Growing experience with extracorporeal membrane oxygenation as a bridge to lung transplantation.

    Science.gov (United States)

    Shafii, Alexis E; Mason, David P; Brown, Chase R; Vakil, Nakul; Johnston, Douglas R; McCurry, Kenneth R; Pettersson, Gosta B; Murthy, Sudish C

    2012-01-01

    Extracorporeal membrane oxygenation (ECMO) is rarely used as a bridge to lung transplantation (BTT) because of its associated morbidity and mortality. However, recent advancements in perfusion technology and critical care have revived interest in this application of ECMO. We retrospectively reviewed our utilization of ECMO as BTT and evaluated our early and midterm results. Nineteen patients were placed on ECMO with the intent to transplant of which 14 (74%) were successfully transplanted. Early and midterm survival of transplanted patients was 75% (1 year) and 63% (3 years), respectively, with the most favorable results observed in interstitial lung disease patients supported in the venovenous configuration. Extracorporeal membrane oxygenation-bridged transplant survival rates were equivalent to nonbridged recipients, but early morbidity and mortality are high and the failure to bridge to transplant is significant. Overall, successfully bridged patients can derive a tangible benefit, albeit with considerable consumption of resources.

  7. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  8. Liver fibrosis after extracorporeal shock-wave lithotripsy of gallbladder stones - A case report

    NARCIS (Netherlands)

    P.W. Plaisier; J.F. Hamming (Jaap); R.L. van der Hul (René); R. den Toom (Rene); H.A. Bruining (Hajo)

    1994-01-01

    textabstractWe encountered significant liver fibrosis in a healthy young patient undergoing laparoscopic cholecystectomy for symptomatic gallstone disease. Twelve months prior to cholecystectomy the patient underwent multiple extracorporeal shock-wave lithotripsy (ESWL) sessions with adjuvant oral

  9. Extracorporeal respiratory support in adult patients.

    Science.gov (United States)

    Romano, Thiago Gomes; Mendes, Pedro Vitale; Park, Marcelo; Costa, Eduardo Leite Vieira

    2017-01-01

    In patients with severe respiratory failure, either hypoxemic or hypercapnic, life support with mechanical ventilation alone can be insufficient to meet their needs, especially if one tries to avoid ventilator settings that can cause injury to the lungs. In those patients, extracorporeal membrane oxygenation (ECMO), which is also very effective in removing carbon dioxide from the blood, can provide life support, allowing the application of protective lung ventilation. In this review article, we aim to explore some of the most relevant aspects of using ECMO for respiratory support. We discuss the history of respiratory support using ECMO in adults, as well as the clinical evidence; costs; indications; installation of the equipment; ventilator settings; daily care of the patient and the system; common troubleshooting; weaning; and discontinuation. RESUMO Em pacientes com insuficiência respiratória grave (hipoxêmica ou hipercápnica), o suporte somente com ventilação mecânica pode ser insuficiente para suas necessidades, especialmente quando se tenta evitar o uso de parâmetros ventilatórios que possam causar danos aos pulmões. Nesses pacientes, extracorporeal membrane oxygenation (ECMO, oxigenação extracorpórea por membrana), que também é muito eficaz na remoção de dióxido de carbono do sangue, pode manter a vida, permitindo o uso de ventilação pulmonar protetora. No presente artigo de revisão, objetivamos explorar alguns dos aspectos mais relevantes do suporte respiratório por ECMO. Discutimos a história do suporte respiratório por ECMO em adultos; evidências clínicas; custos; indicações; instalação do equipamento; parâmetros ventilatórios; cuidado diário do paciente e do sistema; solução de problemas comuns; desmame e descontinuação.

  10. Planetary Atmosphere and Surfaces Chamber (PASC: A Platform to Address Various Challenges in Astrobiology

    Directory of Open Access Journals (Sweden)

    Eva Mateo-Marti

    2014-08-01

    Full Text Available The study of planetary environments of astrobiological interest has become a major challenge. Because of the obvious technical and economical limitations on in situ planetary exploration, laboratory simulations are one of the most feasible research options to make advances both in planetary science and in developing a consistent description of the origin of life. With this objective in mind, we applied vacuum technology to the design of versatile vacuum chambers devoted to the simulation of planetary atmospheres’ conditions. These vacuum chambers are able to simulate atmospheres and surface temperatures representative of the majority of planetary objects, and they are especially appropriate for studying the physical, chemical and biological changes induced in a particular sample by in situ irradiation or physical parameters in a controlled environment. Vacuum chambers are a promising potential tool in several scientific and technological fields, such as engineering, chemistry, geology and biology. They also offer the possibility of discriminating between the effects of individual physical parameters and selected combinations thereof. The implementation of our vacuum chambers in combination with analytical techniques was specifically developed to make feasible the in situ physico-chemical characterization of samples. Many wide-ranging applications in astrobiology are detailed herein to provide an understanding of the potential and flexibility of these experimental systems. Instruments and engineering technology for space applications could take advantage of our environment-simulation chambers for sensor calibration. Our systems also provide the opportunity to gain a greater understanding of the chemical reactivity of molecules on surfaces under different environments, thereby leading to a greater understanding of interface processes in prebiotic chemical reactions and facilitating studies of UV photostability and photochemistry on surfaces

  11. Geometric optimization of microreactor chambers to increase the homogeneity of the velocity field

    Science.gov (United States)

    Pálovics, Péter; Ender, Ferenc; Rencz, Márta

    2018-06-01

    In this work microfluidic flow-through chambers are investigated. They are filled with magnetic nanoparticle (MNP) suspension in order to facilitate enzymatic reactions. The enzyme is immobilized on the surface of the MNPs. These reactions have been found to be flow rate dependent. To overcome this issue various chamber geometries have been examined and optimized geometries have been designed and tested experimentally. The investigation is supported with dedicated CFD simulations using the open source software OpenFOAM. The paper presents the theoretical background and the results of the simulations. The simulations have been verified with measurements and these too are presented in the paper.

  12. Test chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2009-01-01

    A test chamber for measuring electromagnetic radiation emitted by an apparatus to be tested or for exposing an apparatus to be tested to an electromagnetic radiation field. The test chamber includes a reverberation chamber made of a conductive tent fabric. To create a statistically uniform field in

  13. Simulation and prototyping of 2 m long resistive plate chambers for detection of fast neutrons and multi-neutron event identification

    Energy Technology Data Exchange (ETDEWEB)

    Elekes, Z., E-mail: z.elekes@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Aumann, T. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Technische Universität Darmstadt, Darmstadt (Germany); Bemmerer, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Boretzky, K. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Caesar, C. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Technische Universität Darmstadt, Darmstadt (Germany); Cowan, T.C. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universität Dresden, Dresden (Germany); Hehner, J.; Heil, M. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Kempe, M. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Rossi, D. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Röder, M. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universität Dresden, Dresden (Germany); Simon, H. [GSI Helmholtzzentrumfür Schwerionenforschung, Darmstadt (Germany); Sobiella, M.; Stach, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Reinhardt, T. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universität Dresden, Dresden (Germany); Wagner, A.; Yakorev, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Zilges, A. [Universität zu Köln, Köln (Germany); Zuber, K. [Technische Universität Dresden, Dresden (Germany)

    2013-02-11

    Resistive plate chamber (RPC) prototypes of 2 m length were simulated and built. The experimental tests using a 31 MeV electron beam, discussed in details, showed an efficiency higher than 90% and an excellent time resolution of around σ=100ps. Furthermore, comprehensive simulations were performed by GEANT4 toolkit in order to study the possible use of these RPCs for fast neutron (200 MeV–1 GeV) detection and multi-neutron event identification. The validation of simulation parameters was carried out via a comparison to experimental data. A possible setup for invariant mass spectroscopy of multi-neutron emission is presented and the characteristics are discussed. The results show that the setup has a high detection efficiency. Its capability of determining the momentum of the outgoing neutrons and reconstructing the relative energy between the fragments from nuclear reactions is demonstrated for different scenarios.

  14. Simulation of the Interaction of X-rays with a Gas in an Ionization Chamber by the Monte Carlo Method; Simulacion Monte Carlo de la Interaccion de Rays X con el Gas de una Camara de Ionizacion

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Garcia Gomez-Tejedor, G.

    2001-07-01

    The final objective of any ionization chamber is the measurement of the energy amount or radiation dose absorbed by the gas into the chamber. The final value depends on the composition of the gas, its density and temperature, the ionization chamber geometry, and type and intensity of the radiation. We describe a Monte Carlo simulation method, which allows one to compute the dose absorbed by the gas for a X-ray beam. Verification of model has been carried out by simulating the attenuation of standard X-ray radiation through the half value layers established in the ISO 4037 report, while assuming a Weibull type energy distribution for the incident photons. (Author) 6 refs.

  15. em>In vivoem> biological response to extracorporeal shockwave therapy in human tendinopathy

    DEFF Research Database (Denmark)

    Waugh, C. M.; Morrissey, D.; Jones, E.

    2015-01-01

    Extracorporeal shock wave therapy (ESWT) is a non-invasive treatment for chronic tendinopathies, however little is known about the in-vivo biological mechanisms of ESWT. Using microdialysis, we examined the real-time biological response of healthy and pathological tendons to ESWT. A single session...

  16. Experimental and Simulation-Based Investigation of Polycentric Motion of an Inherent Compliant Pneumatic Bending Actuator with Skewed Rotary Elastic Chambers

    Directory of Open Access Journals (Sweden)

    André Wilkening

    2017-01-01

    Full Text Available To offer a functionality that could not be found in traditional rigid robots, compliant actuators are in development worldwide for a variety of applications and especially for human–robot interaction. Pneumatic bending actuators are a special kind of such actuators. Due to the absence of fixed mechanical axes and their soft behavior, these actuators generally possess a polycentric motion ability. This can be very useful to provide an implicit self-alignment to human joint axes in exoskeleton-like rehabilitation devices. As a possible realization, a novel bending actuator (BA was developed using patented pneumatic skewed rotary elastic chambers (sREC. To analyze the actuator self-alignment properties, knowledge about the motion of this bending actuator type, the so-called skewed rotary elastic chambers bending actuator (sRECBA, is of high interest and this paper presents experimental and simulation-based kinematic investigations. First, to describe actuator motion, the finite helical axes (FHA of basic actuator elements are determined using a three-dimensional (3D camera system. Afterwards, a simplified two-dimensional (2D kinematic simulation model based on a four-bar linkage was developed and the motion was compared to the experimental data by calculating the instantaneous center of rotation (ICR. The equivalent kinematic model of the sRECBA was realized using a series of four-bar linkages and the resulting ICR was analyzed in simulation. Finally, the FHA of the sRECBA were determined and analyzed for three different specific motions. The results show that the actuator’s FHA adapt to different motions performed and it can be assumed that implicit self-alignment to the polycentric motion of the human joint axis will be provided.

  17. Simulations of fusion chamber dynamics and first wall response in a Z-pinch driven fusion–fission hybrid power reactor (Z-FFR)

    Energy Technology Data Exchange (ETDEWEB)

    Qi, J.M., E-mail: qjm06@sina.com [Laboratory of Advanced Nuclear Energy (LANE), Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621999 (China); Center for Fusion Energy Science and Technology (CFEST), China Academy of Engineering Physics, Mianyang 621999 (China); Wang, Z., E-mail: wangz_es@caep.cn [Laboratory of Advanced Nuclear Energy (LANE), Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621999 (China); Center for Fusion Energy Science and Technology (CFEST), China Academy of Engineering Physics, Mianyang 621999 (China); Chu, Y.Y., E-mail: chuyanyun@caep.cn [Laboratory of Advanced Nuclear Energy (LANE), Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621999 (China); Center for Fusion Energy Science and Technology (CFEST), China Academy of Engineering Physics, Mianyang 621999 (China); Li, Z.H., E-mail: lee_march@sina.com [Laboratory of Advanced Nuclear Energy (LANE), Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621999 (China)

    2016-03-15

    Highlights: • Z-FFR utilizes DT neutrons to drive a sub-critical fission blanket to produce energy. • A metal shell and Ar gas are employed in the fusion chamber for shock mitigation. • Massive materials can effectively mitigate the thermal heats on the chamber wall. • The W-coated Zr-alloy first wall exhibits good viability as a long-lived component. - Abstract: In a Z-pinch driven fusion–fission hybrid power reactor (Z-FFR), the fusion target will produce enormous energy of ∼1.5 GJ per pulse at a frequency of 0.1 Hz. Almost 20% of the fusion energy yield, approximately 300 MJ, is released in forms of pulsed X-rays. To prevent the first wall from fatal damages by the intense X-rays, a thin spherical metal shell and rare Ar buffer gas are introduced to mitigate the transient X-ray bursts. Radiation hydrodynamics in the fusion chamber were investigated by MULTI-1D simulations, and the corresponding thermal and mechanical loads on the first wall were also obtained. The simulations indicated that by optimizing the design parameters of the metal shell and Ar buffer gas, peak power flux of the thermal heats on the first wall could be mitigated to less than 10{sup 4} W/cm{sup 2} within a time scale of several milliseconds, while peak overpressures of the mechanical loads varying from 0.6 to 0.7 MPa. In addition, the thermomechanical response in a W–coated Zr-alloy first wall was performed by FWDR1D calculations using the derived thermal and mechanical loads as inputs. The temperature and stress fields were analyzed, and the corresponding elastic strains were conducted for primary lifetime estimations by using the Coffin–Manson relationships of both W and Zr-alloy. It was shown that the maximum temperature rises and stresses in the first wall were less than 50 K and 130 MPa respectively, and lifetime of the first wall would be in excess of 10{sup 9} cycles. The chamber exhibits good viability as a long-lived component to sustain the Z-FFR conceptual

  18. Nodular Scleroderma - Successful Treatment With Extracorporeal Photochemotherapy

    Directory of Open Access Journals (Sweden)

    Wollina U

    2001-01-01

    Full Text Available Nodular seleroderma is rare variant of circumscribed scleroderma (morphea. Treatment is often unsatisfactory. This report is on the use of extracorporeal photochemotherapy. A 12 year old girl and a 49 year old woman have been treated once a month on two consecutive days. A complete remission was achieved in one patient after 10 months and an almost complete remission in the young girl after 6 months. The treatment was well-tolerated and no severe side â€" effects occurred. In contrast to previous attempts in treating nodular scleroderma with different modalities, ECP seems to be an effective therapy.

  19. Intercomparison of measurements of NO2 concentrations in the atmosphere simulation chamber SAPHIR during the NO3Comp campaign

    Directory of Open Access Journals (Sweden)

    H. Fuchs

    2010-01-01

    Full Text Available NO2 concentrations were measured by various instruments during the NO3Comp campaign at the atmosphere simulation chamber SAPHIR at Forschungszentrum Jülich, Germany, in June 2007. Analytical methods included photolytic conversion with chemiluminescence (PC-CLD, broadband cavity ring-down spectroscopy (BBCRDS, pulsed cavity ring-down spectroscopy (CRDS, incoherent broadband cavity-enhanced absorption spectroscopy (IBB\\-CEAS, and laser-induced fluorescence (LIF. All broadband absorption spectrometers were optimized for the detection of the main target species of the campaign, NO3, but were also capable of detecting NO2 simultaneously with reduced sensitivity. NO2 mixing ratios in the chamber were within a range characteristic of polluted, urban conditions, with a maximum mixing ratio of approximately 75 ppbv. The overall agreement between measurements of all instruments was excellent. Linear fits of the combined data sets resulted in slopes that differ from unity only within the stated uncertainty of each instrument. Possible interferences from species such as water vapor and ozone were negligible under the experimental conditions.

  20. USING 14 C METHODOLOGY IN SMOG CHAMBER RESEARCH

    Science.gov (United States)

    Smog chambers are large enclosures (~ 10-200 m3) that are used to perform laboratory simulations of atmospheric reactions. By dealing with simple systems in which the number of reactants is limited and the conditions are strictly controlled, insights on how reactions ...

  1. Diagnostic imaging for preparation of extracorporeal shockwave lithotripsy of gallbladder stones

    International Nuclear Information System (INIS)

    Brandstetter, K.; Golder, W.; Neuhaus, H.

    1991-01-01

    Extracorporeal shockwave lithotripsy can be applied as a non-invasive treatment of patients with predominantly cholesterol-type gallstones. As for this treatment, gall bladder contractility and patency of the ductus cysticus must be guaranteed, CT and sonography are applied to check these conditions, and also to determine the size and number of gallstones. (DG) [de

  2. SMART Tubing Presents an Increased Risk of Disconnection During Extracorporeal Circulation

    Science.gov (United States)

    Newling, Ross; Morris, Richard

    2005-01-01

    Abstract: A number of products exhibiting biocompatible features have been developed for use in extracorporeal blood circuits during cardiopulmonary bypass procedures. While attention has been focused on biocompatibility features of the blood-circuit interface, a number of issues applicable in clinical use of these circuits have arisen. Surface Modifying Additive Technology (SMART; Cobe Cardiovascular, Arvarda, CO) is one such technology. In this product, the structure of normal polyvinylchloride (PVC) tubing is altered through the blending of two copolymers to give a more biocompatible blood to plastic interface. In this study, we examined the in vitro mechanical ability of random samples (n = 10) of SMART and standard PVC tubing to withstand axial tension when the tubing was placed over a single barb of a connector. The tension required to remove the SMART tubing from the connector (83.3 ± 7.3 [SD] N), was significantly less than standard PVC tubing (115.6 ± 15.9 N; p tubing exhibited a 28% reduction in tubing to connector adhesion, which may have a significant effect on extracorporeal circuit disconnection and overall patient safety. PMID:16524161

  3. Emerging indications for extracorporeal membrane oxygenation in adults with respiratory failure.

    Science.gov (United States)

    Abrams, Darryl; Brodie, Daniel

    2013-08-01

    Recent advances in technology have spurred the increasing use of extracorporeal membrane oxygenation (ECMO) in patients with severe hypoxemic respiratory failure. However, this accounts for only a small percentage of patients with respiratory failure. We envision the application of ECMO in many other forms of respiratory failure in the coming years. Patients with less severe forms of acute respiratory distress syndrome, for instance, may benefit from enhanced lung-protective ventilation with the very low tidal volumes made possible by direct carbon dioxide removal from the blood. For those in whom hypercapnia predominates, extracorporeal support will allow for the elimination of invasive mechanical ventilation in some cases. The potential benefits of ECMO may be further enhanced by improved techniques, which facilitate active mobilization. Although ECMO for these and other expanded applications is under active investigation, it has yet to be proven beneficial in these settings in rigorous controlled trials. Ultimately, with upcoming and future technological advances, there is the promise of true destination therapy, which could lead to a major paradigm shift in the management of respiratory failure.

  4. Extracorporeal blood irradiation (ECIB) by the 137Cs-teletherapy unit. Pt. 2

    International Nuclear Information System (INIS)

    Scherer, E.; Makoski, H.B.

    1976-01-01

    The present report on experiences with extracorporeal blood irradiation comprises a systematical investigation of the conditions in blood picture and, in one case, of the morphological findings with lymph node punctures, during long-term treatment of two selected patients with a rather different course of the disease. One of the cases showed a typical pattern of chronic lymphadenosis which was to be influenced fairly well; the other case revealed an aggressive tendency with only a feeble response to extracorporeal blood irradiation. By means of toluidine blue staining, until now being used for the verification of nucleoli and their different shapes only in experimentations on animals, a good correlation of the nucleole analysis in the peripheral blood picture and in the lymph node biopsies with the clinical progress of the disease has been observed. Thus, this simple cytological method combined with customary clinical examinations may serve as a criterion for the judgement on the course of the disease and on the therapeutic success. (orig./MG) [de

  5. Flow Characteristics of Multi-circular Jet Plate in Premix Chamber of Air-Assist Atomizer for Burner System

    Directory of Open Access Journals (Sweden)

    Amirnordin Shahrin Hisham

    2016-01-01

    Full Text Available The flow characteristics of multi-circular jet (MCJ plate in the premix chamber of an atomizer were investigated using Computational Fluid Dynamics. Multiphase volume of fluid behavior inside the chamber was determined via steady simulations. The Eulerian–Eulerian two-fluid approach was used for execution mixing of diesel fuel and air. Spray simulation using the discrete phase with injection was generated from the nozzle hole into the ambient atmosphere. The behavior of three MCJ plates in the premix chamber was studied numerically. Results illustrated that plate open area, Ae, influenced the turbulence inside the chamber. MCJ 3, which had the lowest open area, generated the highest flow velocity and turbulence kinetic energy compared with MCJ 1 and 2. The MCJ plates could increase the turbulence in the premix chamber and contribute to the combustion efficiency.

  6. Technical Note: A numerical test-bed for detailed ice nucleation studies in the AIDA cloud simulation chamber

    Directory of Open Access Journals (Sweden)

    R. J. Cotton

    2007-01-01

    Full Text Available The AIDA (Aerosol Interactions and Dynamics in the Atmosphere aerosol and cloud chamber of Forschungszentrum Karlsruhe can be used to test the ice forming ability of aerosols. The AIDA chamber is extensively instrumented including pressure, temperature and humidity sensors, and optical particle counters. Expansion cooling using mechanical pumps leads to ice supersaturation conditions and possible ice formation. In order to describe the evolving chamber conditions during an expansion, a parcel model was modified to account for diabatic heat and moisture interactions with the chamber walls. Model results are shown for a series of expansions where the initial chamber temperature ranged from −20°C to −60°C and which used desert dust as ice forming nuclei. During each expansion, the initial formation of ice particles was clearly observed. For the colder expansions there were two clear ice nucleation episodes. In order to test the ability of the model to represent the changing chamber conditions and to give confidence in the observations of chamber temperature and humidity, and ice particle concentration and mean size, ice particles were simply added as a function of time so as to reproduce the observations of ice crystal concentration. The time interval and chamber conditions over which ice nucleation occurs is therefore accurately known, and enables the model to be used as a test bed for different representations of ice formation.

  7. Study of energy determination of gamma-ray observed with an emulsion chamber with a large gap

    International Nuclear Information System (INIS)

    Inui, Tamiki; Otsuka, Taeko; Masaoka, Akiko

    1982-01-01

    The development of large size emulsion chambers has been made to study very high energy events. For this purpose, the chambers with exchangeable light sensitive layers are considered. The chambers have large gap for the exchange. In this case, it becomes hard to determine the energy of cascade shower. In this report, the authors describe on the experimental examples observed at Mt. Chacaltaya. The effect of a gap was investigated by these examples, and the simulation method by Okamoto and Shibata was applied to the chamber. The chamber used for the observation consisted of the top chamber of 11 c.u. and the bottom chamber of 15 c.u. There was a large gap of 170 cm between two chambers. Twelve showers in three families observed by this system were analyzed. The difference between the blackness in the top and bottom films was studied quantitatively. The blackness was calibrated for the electron density. Four methods of energy determination were studied. Among them, a method to employ the sum of the maximum blackness of a top film and that of a bottom one was used for the analysis. This method seemed to be more reliable than the old method. It was found by a simulation calculation that the recovery of shower in the bottom chamber was seen not only by hardrons but also by gamma-ray. (Kato, T.)

  8. Investigation of OH Radical Regeneration from Isoprene Oxidation Across Different NOx Regimes in the Atmosphere Simulation Chamber SAPHIR

    Science.gov (United States)

    Novelli, A.; Bohn, B.; Dorn, H. P.; Häseler, R.; Hofzumahaus, A.; Kaminski, M.; Yu, Z.; Li, X.; Tillmann, R.; Wegener, R.; Fuchs, H.; Kiendler-Scharr, A.; Wahner, A.

    2017-12-01

    The hydroxyl radical (OH) is the dominant daytime oxidant in the troposphere. It starts the degradation of volatile organic compounds (VOC) originating from both anthropogenic and biogenic emissions. Hence, it is a crucial trace species in model simulations as it has a large impact on many reactive trace gases. Many field campaigns performed in isoprene dominated environment in low NOx conditions have shown large discrepancies between the measured and the modelled OH radical concentrations. These results have contributed to the discovery of new regeneration paths for OH radicals from isoprene-OH second generation products with maximum efficiency at low NO. The current chemical models (e.g. MCM 3.3.1) include this novel chemistry allowing for an investigation of the validity of the OH regeneration at different chemical conditions. Over 11 experiments focusing on the OH oxidation of isoprene were performed at the SAPHIR chamber in the Forschungszentrum Jülich. Measurements of VOCs, NOx, O3, HONO were performed together with the measurement of OH radicals (by both LIF-FAGE and DOAS) and OH reactivity. Within the simulation chamber, the NO mixing ratio was varied between 0.05 to 2 ppbv allowing the investigation of both the "new" regeneration path for OH radicals and the well-known NO+HO2 mechanism. A comparison with the MCM 3.3.1 that includes the upgraded LIM1 mechanism showed very good agreement (within 10%) for the OH data at all concentrations of NOx investigated. Comparison with different models, without LIM1 and with updated rates for the OH regeneration, will be presented together with a detailed analysis of the impact of this study on results from previous field campaigns.

  9. Chamber transport

    International Nuclear Information System (INIS)

    Olson, Craig L.

    2001-01-01

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system

  10. Behaviour of large cylindrical drift chambers in a superconducting solenoid

    International Nuclear Information System (INIS)

    Boer, W. de; Fues, W.; Grindhammer, G.; Kotthaus, R.; Lierl, H.; Moss, L.

    1980-04-01

    We describe the construction and behaviour of a set of cylindrical drift chambers operating inside a superconducting solenoid with a central magnetic field of 1.3 T. The chambers are part of the 4 π detector CELLO at the e + e - storage ring PETRA in Hamburg. The chambers were designed without field shaping to keep them as simple as possible. In order to parametrize accurately the nonlinear space-time relation, we used a computer simulation of the drift process in inhomogenous electric and magnetic fields. With such a parametrization we achieved a resolution of 210 μm, averaged over the whole drift cell and angles of incidence up to 30 0 . (orig.)

  11. Monte Carlo calculations of electron beam quality conversion factors for several ion chamber types

    Energy Technology Data Exchange (ETDEWEB)

    Muir, B. R., E-mail: Bryan.Muir@nrc-cnrc.gc.ca [Measurement Science and Standards, National Research Council Canada, 1200 Montreal Road, Ottawa, Ontario K1A 0R6 (Canada); Rogers, D. W. O., E-mail: drogers@physics.carleton.ca [Carleton Laboratory for Radiotherapy Physics, Physics Department, Carleton University, 1125 ColonelBy Drive, Ottawa, Ontario K1S 5B6 (Canada)

    2014-11-01

    Purpose: To provide a comprehensive investigation of electron beam reference dosimetry using Monte Carlo simulations of the response of 10 plane-parallel and 18 cylindrical ion chamber types. Specific emphasis is placed on the determination of the optimal shift of the chambers’ effective point of measurement (EPOM) and beam quality conversion factors. Methods: The EGSnrc system is used for calculations of the absorbed dose to gas in ion chamber models and the absorbed dose to water as a function of depth in a water phantom on which cobalt-60 and several electron beam source models are incident. The optimal EPOM shifts of the ion chambers are determined by comparing calculations of R{sub 50} converted from I{sub 50} (calculated using ion chamber simulations in phantom) to R{sub 50} calculated using simulations of the absorbed dose to water vs depth in water. Beam quality conversion factors are determined as the calculated ratio of the absorbed dose to water to the absorbed dose to air in the ion chamber at the reference depth in a cobalt-60 beam to that in electron beams. Results: For most plane-parallel chambers, the optimal EPOM shift is inside of the active cavity but different from the shift determined with water-equivalent scaling of the front window of the chamber. These optimal shifts for plane-parallel chambers also reduce the scatter of beam quality conversion factors, k{sub Q}, as a function of R{sub 50}. The optimal shift of cylindrical chambers is found to be less than the 0.5 r{sub cav} recommended by current dosimetry protocols. In most cases, the values of the optimal shift are close to 0.3 r{sub cav}. Values of k{sub ecal} are calculated and compared to those from the TG-51 protocol and differences are explained using accurate individual correction factors for a subset of ion chambers investigated. High-precision fits to beam quality conversion factors normalized to unity in a beam with R{sub 50} = 7.5 cm (k{sub Q}{sup ′}) are provided. These

  12. Bacterial sepsis after extracorporeal shock-wave lithotripsy (ESWL) of calyceal diverticular stone.

    Science.gov (United States)

    Oh, Mi Mi; Kim, Jin Wook; Kim, Jong Wook; Chae, Ji Yun; Yoon, Cheol Yong; Park, Hong Seok; Park, Min Gu; Moon, Du Geon

    2013-02-01

    Most calyceal diverticula are asymptomatic but symptoms occur when there is urinary stasis leading to infection and calculi. Septic shock after ESWL of calyceal stone occurs rarely. A 24-year-old woman had septic shock due to after extracorporeal shock-wave lithotripsy (ESWL) of asymptomatic calyceal diverticular stone.

  13. Effects of extracorporeal shock wave lithotripsy on the kidney and perinephric tissues: CT evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kounn Sik; Kim, Kun Sang; Kim, Sae Chul [College of Medicine, Chung-Ang University, Seoul (Korea, Republic of)

    1987-12-15

    Since the first successful treatment of the patient with renal stone by extracorporeal shock wave lithotripsy at the Institute for Surgical Research, West Germany, on February 7, 1980, extracorporeal shock wave lithotripsy (ESWL) has been a non-invasive technique for the treatment of the renal and ureteral calculi. In spite of the fact that the acoustic energy of the focused shock waves must pass through the soft tissues of back, perinephric tissues and renal parenchyme before reaching calculi, little is known about the effects of ESWL in the renal parenchyme and perinephric soft tissues. So we analyzed a pre and post-ESWL computed tomography scans of the kidneys in 130 patients treated at our hospital during a three month period to evaluate the effects of ESWL on the kidney and perinephric soft tissues.

  14. Effects of extracorporeal shock wave lithotripsy on the kidney and perinephric tissues: CT evaluation

    International Nuclear Information System (INIS)

    Song, Kounn Sik; Kim, Kun Sang; Kim, Sae Chul

    1987-01-01

    Since the first successful treatment of the patient with renal stone by extracorporeal shock wave lithotripsy at the Institute for Surgical Research, West Germany, on February 7, 1980, extracorporeal shock wave lithotripsy (ESWL) has been a non-invasive technique for the treatment of the renal and ureteral calculi. In spite of the fact that the acoustic energy of the focused shock waves must pass through the soft tissues of back, perinephric tissues and renal parenchyme before reaching calculi, little is known about the effects of ESWL in the renal parenchyme and perinephric soft tissues. So we analyzed a pre and post-ESWL computed tomography scans of the kidneys in 130 patients treated at our hospital during a three month period to evaluate the effects of ESWL on the kidney and perinephric soft tissues

  15. Performance of the ATLAS Muon Drift-Tube Chambers at High Background Rates and in Magnetic Fields

    CERN Document Server

    INSPIRE-00213689; Horvat, S.; Legger, F.; Kortner, O.; Kroha, H.; Richter, R.; Valderanis, Ch.; Rauscher, F.; Staude, A.

    2016-01-01

    The ATLAS muon spectrometer uses drift-tube chambers for precision tracking. The performance of these chambers in the presence of magnetic field and high radiation fluxes is studied in this article using test-beam data recorded in the Gamma Irradiation Facility at CERN. The measurements are compared to detailed predictions provided by the Garfield drift-chamber simulation programme.

  16. Local experience with extracorporeal membrane oxygenation in children with acute fulminant myocarditis.

    Directory of Open Access Journals (Sweden)

    Botao Ning

    Full Text Available To analyze the clinical effect of extracorporeal membrane oxygenation (ECMO in children with acute fulminant myocarditis, we retrospectively analyzed the data of five children with acute fulminant myocarditis in the intensive care unit (ICU at the Affiliated Children's Hospital, Zhejiang University from February 2009 to November 2012. The study group included two boys and three girls ranging in age from 9 to 13 years (median 10 years. Body weight ranged from 25 to 33 kg (mean 29.6 kg. They underwent extracorporeal membrane oxygenation (ECMO through a venous-arterial ECMO model with an average ECMO supporting time of 89.8 h (40-142 h. Extracorporeal circulation was established in all five children. After treatment with ECMO, the heart rate, blood pressure, and oxygen saturation were greatly improved in the four children who survived. These four children were successfully weaned from ECMO and discharged from hospital machine-free, for a survival rate of 80% (4/5. One child died still dependent on the machine. Cause of death was irrecoverable cardiac function and multiple organ failure. Complications during ECMO included three cases of suture bleeding, one case of acute hemolytic renal failure and suture bleeding, and one case of hyperglycemia. During the follow-up period of 4-50 months, the four surviving children recovered with normal cardiac function and no abnormal functions of other organs. The application of ECMO in acute fulminant myocarditis, even in local centers that experience low incidence of this disease, remains an effective approach. Larger studies to determine optimal timing of placement on ECMO to guide local centers are warranted.

  17. Ionization chamber gradient effects in nonstandard beam configurations

    International Nuclear Information System (INIS)

    Bouchard, Hugo; Seuntjens, Jan; Carrier, Jean-Francois; Kawrakow, Iwan

    2009-01-01

    perturbation correction factors in nonstandard beam reference dosimetry, two possible ways to report absorbed dose are suggested: (1) Reporting average dose to the sensitive volume of the chamber filled with water, combined with removing the reference field implicit gradient effect when measuring output factors, and (2) reporting average dose to the chamber itself during output factor verifications. The first option could be adopted if clinical beam correction factors are negligible. The second option could simplify quality assurance procedures when correction factors are not negligible and have to be calculated using Monte Carlo simulations.

  18. METHODS OF EXTRACORPOREAL HEMOCORRECTION IN COMPLEX TREATMENT OF BACTERIAL AND VIRAL INFECTIONS AFTER KIDNEY TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    A. V. Vatazin

    2013-01-01

    Full Text Available Scientific publications devoted to the contemporary prospective selected and combined extracorporeal modalities to treat complications after renal allotransplantation were analyzed involving pyoseptic processes and viral hepatites.

  19. Ionization Chambers for the LHC Beam Loss Detection

    CERN Document Server

    Assmann, R W; Ferioli, G; Gschwendtner, E; Kain, V

    2003-01-01

    At the Large Hadron Collider (LHC) a beam loss system will be used to prevent and protect superconducting magnets against coil quenches and coil damages. Ionisation chambers will be mounted outside the cryostat to measure the secondary shower particles caused by lost beam particles. Since the stored particle beam intensity is eight orders of magnitude larger than the lowest quench level and the losses should be detected with a relative error of two, the design and the location of the detectors have to be optimised. For that purpose a two-fold simulation was carried out. The longitudinal loss locations of the tertiary halo is investigated by tracking the halo through several magnet elements. These loss distributions are combined with simulations of the particle fluence outside the cryostat, which is induced by lost protons at the vacuum pipe. The base-line ionisation chamber has been tested at the PS Booster in order to determine the detector response at the high end of the dynamic range.

  20. The effect of epoprostenol on platelet activation and consumption during experimental extracorporeal perfusion

    DEFF Research Database (Denmark)

    Skogby, M; Adrian, K; Friberg, L

    1999-01-01

    Hemorrhages are major complications experienced in 10-35% of neonates treated with extracorporeal life support (ECLS). The increased bleeding tendency is partly due to an ECLS induced thrombocytopenia and impaired platelet function. In the present study, we evaluated the effect of epoprostenol on...

  1. Non-intubated recovery from refractory cardiogenic shock on percutaneous VA-extracorporeal membrane oxygenation

    NARCIS (Netherlands)

    van Houte, J; Donker, D W; Wagenaar, L J; Slootweg, A P; Kirkels, J H; van Dijk, D

    We report on the use of percutaneous femoral veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in a fully awake, non-intubated and spontaneously breathing patient suffering from acute, severe and refractory cardiogenic shock due to a (sub)acute anterior myocardial infarction. Intensified

  2. HERCULES Advanced Combustion Concepts Test Facility: Spray/Combustion Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, K. [Eidgenoessische Technische Hochschule (ETH), Labor fuer Aerothermochemie und Verbrennungssysteme, Zuerich (Switzerland)

    2004-07-01

    This yearly report for 2004 on behalf of the Swiss Federal Office of Energy (SFOE) at the Laboratory for Aero-thermochemistry and Combustion Systems at the Federal Institute of Technology ETH in Zurich, Switzerland, presents a review of work being done within the framework of HERCULES (High Efficiency R and D on Combustion with Ultra Low Emissions for Ships) - the international R and D project concerning new technologies for ships' diesels. The work involves the use and augmentation of simulation models. These are to be validated using experimental data. The report deals with the development of an experimental set-up that will simulate combustion in large two-stroke diesel engines and allow the generation of reference data. The main element of the test apparatus is a spray / combustion chamber with extensive possibilities for optical observation under variable flow conditions. The results of first simulations confirm concepts and shall help in further work on the project. The potential offered by high-speed camera systems was tested using the institute's existing HTDZ combustion chamber. Further work to be done is reviewed.

  3. Monitoring of the Adult Patient on Venoarterial Extracorporeal Membrane Oxygenation

    Directory of Open Access Journals (Sweden)

    Mabel Chung

    2014-01-01

    Full Text Available Venoarterial extracorporeal membrane oxygenation (VA ECMO provides mechanical support to the patient with cardiac or cardiopulmonary failure. This paper reviews the physiology of VA ECMO including the determinants of ECMO flow and gas exchange. The efficacy of this therapy may be determined by assessing patient hemodynamics and device flow, overall gas exchange support, markers of adequate oxygen delivery, and pulsatility of the arterial blood pressure waveform.

  4. Development of Extracorporeal Shock Wave Therapy for the Treatment for Ischemic Cardiovascular Diseases

    Science.gov (United States)

    Shimokawa, Hiroaki

    Cardiovascular diseases, such as coronary artery disease and peripheral artery disease, are the major causes of death in developed countries, and the number of elderly patients has been rapidly increasing worldwide. Thus, it is crucial to develop new non-invasive therapeutic strategies for these patients. We found that a low-energy shock wave (SW) (about 10% of the energy density that is used for urolithiasis) effectively increases the expression of vascular endothelial growth factor (VEGF) in cultured endothelial cells. Subsequently, we demonstrated that extracorporeal cardiac SW therapy with low-energy SW up-regulates the expression of VEGF, enhances angiogenesis, and improves myocardial ischemia in a pig model of chronic myocardial ischemia without any adverse effects in vivo. Based on these promising results in animal studies, we have subsequently developed a new, non-invasive angiogenic therapy with low-energy SW for cardiovascular diseases. Our extracorporeal cardiac SW therapy improved symptoms and myocardial perfusion evaluated with stress-scintigraphy in patients with severe coronary artery disease without indication of percutaneous coronary intervention or coronary artery bypass surgery. Importantly, no procedural complications or adverse effects were noted. The SW therapy was also effective in ameliorating left ventricular remodeling after acute myocardial infarction in pigs and in enhancing angiogenesis in hindlimb ischemia in animals and patients with coronary artery disease. Furthermore, our recent experimental studies suggest that the SW therapy is also effective for indications other than cardiovascular diseases. Thus, our extracorporeal cardiac SW therapy is an effective, safe, and non-invasive angiogenic strategy for cardiovascular medicine.

  5. Drift chamber

    International Nuclear Information System (INIS)

    Inagaki, Yosuke

    1977-01-01

    Drift chamber is becoming an important detector in high energy physics as a precision and fast position detector because of its high spatial resolution and count-rate. The basic principle is that it utilizes the drift at constant speed of electrons ionized along the tracks of charged particles towards the anode wire in the nearly uniform electric field. The method of measuring drift time includes the analog and digital ones. This report describes about the construction of and the application of electric field to the drift chamber, mathematical analysis on the electric field and equipotential curve, derivation of spatial resolution and the factor for its determination, and selection of gas to be used. The performance test of the chamber was carried out using a small test chamber, the collimated β source of Sr-90, and 500 MeV/C electron beam from the 1.3 GeV electron synchrotron in the Institute of Nuclear Study, University of Tokyo. Most chambers to date adopted one dimensional read-out, but it is very advantageous if the two dimensional read-out is feasible with one chamber when the resolution in that direction is low. The typical methods of delay line and charge division for two dimensional read-out are described. The development of digital read-out system is underway, which can process the signal of a large scale drift chamber at high speed. (Wakatsuki, Y.)

  6. Multiple chamber ionization detector

    International Nuclear Information System (INIS)

    Solomon, E.E.

    1980-01-01

    A multi-chambered ionisation detector enables the amount of radiation entering each chamber from a single radioactive, eg β, source to be varied by altering the proportion of the source protruding into each chamber. Electrodes define chambers and an extended radioactive source is movable to alter the source length in each chamber. Alternatively, the source is fixed relative to outer electrodes but the central electrode may be adjusted by an attached support altering the chamber dimensions and hence the length of source in each. Also disclosed are a centrally mounted source tiltable towards one or other chamber and a central electrode tiltable to alter chamber dimensions. (U.K.)

  7. Doriot Climatic Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — The Doriot Climatic Chambers are two, 60-feet long, 11-feet high, 15-feet wide chambers that are owned and operated by NSRDEC. The Doriot Climatic Chambers are among...

  8. Kidney changes after extracorporeal shock wave lithotripsy; MR evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Hiroyasu; Shindo, Hiroshi; Mabuchi, Nobuhisa; Kawakami, Akira; Fujii, Koichi; Hamada, Tatsumi; Ishida, Osamu; Umekawa, Toru; Kohri, Kenjiro (Kinki Univ., Osakasayama, Osaka (Japan). School of Medicine)

    1991-02-01

    MRI was performed before and after extracorporeal shock wave lithotripsy (ESWL) to determine the effects of ESWL on the kidney and perinephric tissues. Of the 40 kidneys studied, 24 showed one or more changes on MRI: loss of the corticomedullary junction (n=15), subcapsular fluid (n=14), subcapsular hematoma (n=1), thickening of bridging septa (n=8), high intensity area in the muscle (n=8). These relatively subtle changes detected on MRI may not be apparent with other imaging techniques. (author).

  9. Ionization chamber

    International Nuclear Information System (INIS)

    1977-01-01

    An improved ionization chamber type X-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is placed next to the anode and is maintained at a voltage intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting towards the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

  10. Flame kernel characterization of laser ignition of natural gas-air mixture in a constant volume combustion chamber

    Science.gov (United States)

    Srivastava, Dhananjay Kumar; Dharamshi, Kewal; Agarwal, Avinash Kumar

    2011-09-01

    In this paper, laser-induced ignition was investigated for compressed natural gas-air mixtures. Experiments were performed in a constant volume combustion chamber, which simulate end of the compression stroke conditions of a SI engine. This chamber simulates the engine combustion chamber conditions except turbulence of air-fuel mixture. It has four optical windows at diametrically opposite locations, which are used for laser ignition and optical diagnostics simultaneously. All experiments were conducted at 10 bar chamber pressure and 373 K chamber temperature. Initial stage of combustion phenomena was visualized by employing Shadowgraphy technique using a high speed CMOS camera. Flame kernel development of the combustible fuel-air mixture was investigated under different relative air-fuel ratios ( λ=1.2-1.7) and the images were interrogated for temporal propagation of flame front. Pressure-time history inside the combustion chamber was recorded and analyzed. This data is useful in characterizing the laser ignition of natural gas-air mixture and can be used in developing an appropriate laser ignition system for commercial use in SI engines.

  11. Motor performance in five-year-old extracorporeal membrane oxygenation survivors: A population-based study

    NARCIS (Netherlands)

    M.W.G. Nijhuis-van der Sanden (Maria); M.H.M. van der Cammen-van Zijp (Monique); A.J.W.M. Janssen (Anjo); J.J.C.M. Reuser (Jolanda); P. Mazer (Petra); A.F.J. van Heijst (Arno); S.J. Gischler (Saskia); D. Tibboel (Dick); L.A. Kollee

    2009-01-01

    textabstractIntroduction: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a cardio-pulmonary bypass technique to provide life support in acute reversible cardio-respiratory failure when conventional management is not successful. Most neonates receiving ECMO suffer from meconium

  12. Extracorporeal treatment for thallium poisoning: recommendations from the EXTRIP Workgroup.

    Science.gov (United States)

    Ghannoum, Marc; Nolin, Thomas D; Goldfarb, David S; Roberts, Darren M; Mactier, Robert; Mowry, James B; Dargan, Paul I; Maclaren, Robert; Hoegberg, Lotte C; Laliberté, Martin; Calello, Diane; Kielstein, Jan T; Anseeuw, Kurt; Winchester, James F; Burdmann, Emmanuel A; Bunchman, Timothy E; Li, Yi; Juurlink, David N; Lavergne, Valery; Megarbane, Bruno; Gosselin, Sophie; Liu, Kathleen D; Hoffman, Robert S

    2012-10-01

    The EXtracorporeal TReatments In Poisoning (EXTRIP) workgroup was formed to provide recommendations on the use of extracorporeal treatment (ECTR) in poisoning. To test and validate its methods, the workgroup reviewed data for thallium (Tl). After an extensive search, the co-chairs reviewed the articles, extracted the data, summarized findings, and proposed structured voting statements following a predetermined format. A two-round modified Delphi method was chosen to reach a consensus on voting statements and RAND/UCLA Appropriateness Method to quantify disagreement. Blinded votes were compiled, returned, and discussed during a conference call. A second vote determined the final recommendations. Forty-five articles met inclusion criteria. Only case reports and case series were identified, yielding a very low quality of evidence for all recommendations. Data on 74 patients, including 11 who died, were abstracted. The workgroup concluded that Tl is slightly dialyzable and made the following recommendations: ECTR is recommended in severe Tl poisoning (1D). ECTR is indicated if Tl exposure is highly suspected on the basis of history or clinical features (2D) or if the serum Tl concentration is >1.0 mg/L (2D). ECTR should be initiated as soon as possible, ideally within 24-48 hours of Tl exposure (1D), and be continued until the serum Tl concentration is poisoning.

  13. Continuously live image processor for drift chamber track segment triggering

    International Nuclear Information System (INIS)

    Berenyi, A.; Chen, H.K.; Dao, K.

    1999-01-01

    The first portion of the BaBar experiment Level 1 Drift Chamber Trigger pipeline is the Track Segment Finder (TSF). Using a novel method incorporating both occupancy and drift-time information, the TSF system continually searches for segments in the supercells of the full 7104-wire Drift Chamber hit image at 3.7 MHz. The TSF was constructed to operate in a potentially high beam-background environment while achieving high segment-finding efficiency, deadtime-free operation, a spatial resolution of 5 simulated physics events

  14. Extracorporeal complexing hemodialysis system for the treatment of methylmercury poisoning. II. In vivo applications in the dog

    Energy Technology Data Exchange (ETDEWEB)

    Kostyniak, P.J.; Clarkson, T.W.; Abbasi, A.H.

    1977-01-01

    An extracorporeal regional complexing hemodialysis procedure is described which has been successfully applied for the enhancement of removal of methylmercury in the dog. The procedure utilizes the extracorporeal addition of cysteine to arterial blood entering a hemodialyzer, forming a large pool of complexed dialyzable methylmercury in plasma. Diffusion of this methylmercury complex across the dialyzer membrane into dialysate accounts for large amounts of methylmercury being removed from the animal. In conjunction with methylmercury removal, the majority of the infused cysteine is also removed resulting in comparatively low systemic doses of cysteine to the animal. At blood flow rates of 45 ml/min, and dialysate flow rates of approximately 550 ml/min, the mean percentage of methylmercury cleared from blood passing through the dialyzer was 39%. Rates of elimination of methylmercury from the dog could be increased by a factor of 100 during the extracorporeal regional complexing hemodialysis procedure. Regional collimated counting of radioactivity along the length of the dog revealed a decline in all areas including the head region. The procedure was void of any noticeable side effects during treatment or as evidence by histological evaluation of liver and kidney after treatment.

  15. Simulated reaction of formaldehyde and ambient atmospheric particulate matter using a chamber

    Institute of Scientific and Technical Information of China (English)

    Yueyue Chen; Jia Liu; Jing Shang; Tong Zhu

    2017-01-01

    The reaction of HCHO with Beijing winter's real ambient particulate matter (PM) inside a 3.3 m3 Teflon Chamber was conducted in this study.NO2,O3 and H2O gases were removed from the ambient aerosol before entering into the chamber.The decays of HCHO were monitored (acetylacetone spectrophotometry method) during the reactions at different PM number concentrations (Na) and relative humidities (RHs),and the formed particulate formate was detected by IC and XPS techniques.The results showed that when RH was 10%-15%,the decay rate of HCHO in the chamber was higher with the existence of PM from relatively clean days (with number concentration (Na) < 200,000 particle/L,0.35-22.5 μm) compared to dirty days (Na > 200,000 particle/L,0.35-22.5 μm).When RH increased to 30%-45%,PM can hardly have significant influences on the decay of HCHO.The formations of formate on the reacted PM were consistent with the HCHO decay rates at different ambient PM Na and RH conditions.This is a first study related to the "real" ambient PM reacted with HCHO and suggested that in the clean and low RH days,PM could be an effective medium for the conversion of HCHO to formate.

  16. Verbal and visual-spatial memory problems at adolescent age after neonatal extracorporeal membrane oxygenation

    NARCIS (Netherlands)

    M.J. Madderom (Marlous); F.K. Aarsen (Femke); R.M. Schiller (Raisa); S.J. Gischler (Saskia); A.F.J. van Heijst (Arno); D. Tibboel (Dick); H. IJsselstijn (Hanneke)

    2018-01-01

    markdownabstract__Objectives__ To assess neuropsychological outcome in 17- and 18-year–old neonatal extracorporeal membrane oxygenation survivors. __Design__ A prospective longitudinal follow-up study. __Setting__ Follow-up program at the Erasmus MC-Sophia Children’s Hospital in Rotterdam, The

  17. SU-F-T-362: Quantification and Modelling of the Ionization Chamber Simulation Effective Points On Monaco Treatment Planning System

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, R; Bai, W [The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei (China)

    2016-06-15

    Purpose: Because of statistical noise in Monte Carlo dose calculations, effective point doses may not be accurate. Volume spheres are useful for evaluating dose in Monte Carlo plans, which have an inherent statistical uncertainty.We use a user-defined sphere volume instead of a point, take sphere sampling around effective point make the dose statistics to decrease the stochastic errors. Methods: Direct dose measurements were made using a 0.125cc Semiflex ion chamber (IC) 31010 isocentrically placed in the center of a homogeneous Cylindric sliced RW3 phantom (PTW, Germany).In the scanned CT phantom series the sensitive volume length of the IC (6.5mm) were delineated and defined the isocenter as the simulation effective points. All beams were simulated in Monaco in accordance to the measured model. In our simulation using 2mm voxels calculation grid spacing and choose calculate dose to medium and request the relative standard deviation ≤0.5%. Taking three different assigned IC over densities (air electron density(ED) as 0.01g/cm3 default CT scanned ED and Esophageal lumen ED 0.21g/cm3) were tested at different sampling sphere radius (2.5, 2, 1.5 and 1 mm) statistics dose were compared with the measured does. Results: The results show that in the Monaco TPS for the IC using Esophageal lumen ED 0.21g/cm3 and sampling sphere radius 1.5mm the statistical value is the best accordance with the measured value, the absolute average percentage deviation is 0.49%. And when the IC using air electron density(ED) as 0.01g/cm3 and default CT scanned EDthe recommented statistical sampling sphere radius is 2.5mm, the percentage deviation are 0.61% and 0.70%, respectivly. Conclusion: In Monaco treatment planning system for the ionization chamber 31010 recommend air cavity using ED 0.21g/cm3 and sampling 1.5mm sphere volume instead of a point dose to decrease the stochastic errors. Funding Support No.C201505006.

  18. Progress towards realization of a laser IFE solid wall chamber

    International Nuclear Information System (INIS)

    Raffray, A.R.; Blanchard, J.; Latkowski, J.; Najmabadi, F.; Renk, T.; Sethian, J.; Sharafat, S.; Snead, L.

    2006-01-01

    The high average power laser (HAPL) program aims at developing laser inertial fusion energy (Laser IFE) based on lasers, direct drive targets and a solid wall chamber. The preferred first wall configuration is based on tungsten and ferritic steel as armor and structural materials, respectively. A key concern is the survival of the first wall under the X-ray and ion energy deposition from the fusion micro-explosion. The HAPL design and R and D effort in the chamber and material area is focused toward understanding and resolving the key armor survival issues. This includes modeling and experimental testing of the armor thermo-mechanical behavior in facilities utilizing ion, X-rays and laser sources to simulate IFE conditions. Helium management is addressed by conducting implantation experiments along with modeling of He behavior in tungsten. This paper summarizes the HAPL chamber activities. The first wall/armor configuration and design analysis are described, key chamber issues are discussed, and the R and D to address them is highlighted

  19. Ionisation Chambers for the LHC Beam Loss Detection

    CERN Document Server

    Gschwendtner, E; Dehning, B; Ferioli, G; Kain, V

    2003-01-01

    At the Large Hadron Collider (LHC) a beam loss system will be used to prevent and protect superconducting magnets against coil quenches and coil damages. Since the stored particle beam intensity is 8 orders of magnitude larger than the lowest quench level value particular attention is paid to the design of the secondary particle shower detectors. The foreseen ionisation chambers are optimised in geometry simulating the probable loss distribution along the magnets and convoluting the loss distribution with the secondary particle shower distributions. To reach the appropriate coverage of a particle loss and to determine the quench levels with a relative accuracy of 2 the number of the detectors and their lengths is weighted against the particle intensity density variation. In addition attention is paid to the electrical ionisation chamber signal to minimise the ion tail extension. This optimisation is based on time resolved test measurements in the PS booster. A proposal for a new ionisation chamber will be pre...

  20. Low Intensity Extracorporeal Shock Wave Therapy Improves Erectile Function in a Model of Type II Diabetes Independently of NO/cGMP Pathway.

    Science.gov (United States)

    Assaly-Kaddoum, Rana; Giuliano, François; Laurin, Miguel; Gorny, Diane; Kergoat, Micheline; Bernabé, Jacques; Vardi, Yoram; Alexandre, Laurent; Behr-Roussel, Delphine

    2016-09-01

    Erectile dysfunction is highly prevalent in type II diabetes mellitus. Low intensity extracorporeal shock wave therapy improves erectile function in patients with erectile dysfunction of vasculogenic origin, including diabetes. However, its mode of action remains unknown. We investigated the effects of low intensity extracorporeal shock wave therapy compared to or combined with sildenafil on erectile dysfunction in a type II diabetes mellitus model. Our purpose was to test our hypothesis of a mode of action targeting the cavernous nitric oxide/cyclic guanosine monophosphate pathway. GK rats, a validated model of type II diabetes mellitus, and age matched Wistar rats were treated with low intensity extracorporeal shock wave therapy twice weekly for 3 weeks. Treatment was repeated after a 3-week no-treatment interval. The penis was stretched and dipped in a specifically designed water-filled cage. Shock waves were delivered by a calibrated probe yielding a controlled energy flux density (0.09 mJ/mm(2)). The probe was attached to an electrohydraulic unit with a focused shock wave source, allowing for accurate extrapolation to humans. Following a 4-week washout period erectile function was assessed as well as endothelium dependent and independent, and nitrergic relaxations of the corpus cavernosum of GK rats. Low intensity extracorporeal shock wave therapy significantly improved erectile function in GK rats to the same extent as sildenafil. Treatment effects were potentiated when combined with sildenafil. Shock wave effects were not associated with improved cavernous endothelium dependent or independent, or nitrergic reactivity. Low intensity extracorporeal shock wave therapy improved erectile function in GK rats. Unexpectedly, this was not mediated by a nitric oxide/cyclic guanosine monophosphate dependent mechanism. Sildenafil increased shock wave efficacy. This preclinical paradigm to deliver low intensity extracorporeal shock wave therapy to the rat penis should

  1. Normothermic extracorporeal perfusion of isolated porcine liver after warm ischaemia: a preliminary report.

    Science.gov (United States)

    Bellomo, Rinaldo; Suzuki, Satoshi; Marino, Bruno; Starkey, Graeme K; Chambers, Brenton; Fink, Michael A; Wang, Bao Zhong; Houston, Shane; Eastwood, Glenn; Calzavacca, Paolo; Glassford, Neil; Skene, Alison; Jones, Daryl A; Jones, Robert

    2012-09-01

    Liver transplantation is a major life-saving procedure, and donation after cardiac death (DCD) has increased the pool of potential liver donors. However, DCD livers are at increased risk of primary graft dysfunction and biliary tract ischaemia. Normothermic extracorporeal liver perfusion (NELP) may increase the ability to protect, evaluate and, in future, transplant DCD livers. We conducted proof-of-concept experiments using a DCD model in the pig to assess the short-term (4 hours) feasibility and functional efficacy of NELP. Using extracorporeal membrane oxygenation, parenteral nutrition, separate hepatic artery and portal vein perfusion, and physiological perfusion pressures, we achieved NELP and evidence of function (bile production, paracetamol removal, maintenance of normal ammonia and lactate levels) for 4 hours in pig livers subjected to 15 and 30 minutes of cardiac arrest before explantation. Our experiments justify further investigations of the feasibility and efficacy of human DCD liver preservation by ex-vivo perfusion.

  2. Transfusion Associated Hyperkalemia and Cardiac Arrest in an Infant after Extracorporeal Membrane Oxygenation

    Directory of Open Access Journals (Sweden)

    Do Wan Kim

    2015-05-01

    Full Text Available Cardiac arrest associated with hyperkalemia during red blood cell transfusion is a rare but fatal complication. Herein, we report a case of transfusion-associated cardiac arrest following the initiation of extracorporeal membrane oxygenation support in a 9-month old infant. Her serum potassium level was increased to 9.0 mEq/L, soon after the newly primed circuit with pre-stored red blood cell (RBC was started and followed by sudden cardiac arrest. Eventually, circulation was restored and the potassium level decreased to 5.1 mEq/L after 5 min. Extracorporeal membrane oxygenation (ECMO priming is a relatively massive transfusion into a pediatric patient. Thus, to prevent cardiac arrest during blood-primed ECMO in neonates and infants, freshly irradiated and washed RBCs should be used when priming the ECMO circuit, to minimize the potassium concentration. Also, physicians should be aware of all possible complications associated with transfusions during ECMO.

  3. Acoustic sensing of renal stone fragmentation in extracorporeal shockwave lithotripsy

    OpenAIRE

    Fedele, Fiammetta

    2008-01-01

    This thesis describes the research carried out by the author on the exploitation of acoustic emissions detected during extracorporeal shockwave lithotripsy (a non-invasive procedure for the treatment of urinary stones) to develop a new diagnostic system. The work formed part of a research project on lithotripsy undertaken by the University of Southampton in collaboration with Guy's and St Thomas' NHS Foundation Trust (London) and a UK based company, Precision Acoustics Ltd (Dorche...

  4. Severe myocardial injury and extracorporeal membrane oxygenation following perinatal asphyxia

    Directory of Open Access Journals (Sweden)

    P. Benson Ham

    2015-05-01

    Full Text Available Perinatal asphyxia is a common cause of morbidity and mortality in the newborn and is associated with myocardial injury in a significant proportion of cases. Biomarkers, echocardiography, and rhythm disturbances are sensitive indicators of myocardial ischemia and may predict mortality. We present a case of severe myocardial dysfunction immediately after delivery managed with extracorporeal membrane oxygenation (ECMO and discuss the role of cardiac biomarkers, echocardiography, electrocardiography, and ECMO in the asphyxiated newborn.

  5. Characterization of Gas Transport Properties of Fractured Rocks By Borehole and Chamber Tests.

    Science.gov (United States)

    Shimo, M.; Shimaya, S.; Maejima, T.

    2014-12-01

    Gas transport characteristics of fractured rocks is a great concern to variety of engineering applications such as underground storage of LPG, nuclear waste disposal, CCS and gas flooding in the oil field. Besides absolute permeability, relative permeability and capillary pressure as a function of water saturation have direct influences to the results of two phase flow simulation. However, number of the reported gas flow tests for fractured rocks are limited, therefore, the applicability of the conventional two-phase flow functions used for porous media, such as Mualem-van Genuchten model, to prediction of the gas transport in the fractured rock mass are not well understood. The authors conducted the two types of in-situ tests, with different scales, a borehole gas-injection test and a chamber gas-injection test in fractured granitic rock. These tests were conducted in the Cretaceous granitic rocks at the Namikata underground LPG storage cavern construction site in Ehime Prefecture in Japan, preceding to the cavern scale gas-tightness test. A borehole injection test was conducted using vertical and sub-vertical boreholes drilled from the water injection tunnel nearly at the depth of the top of the cavern, EL-150m. A new type downhole gas injection equipment that is capable to create a small 'cavern' within a borehole was developed. After performing a series of preliminary tests to investigate the hydraulic conductivity and gas-tightness, i.e. threshold pressure, gas injection tests were conducted under different gas pressure. Fig.1 shows an example of the test results From a chamber test using a air pressurizing chamber with volume of approximately166m3, the gas-tightness was confirmed within the uncertainty of 22Pa under the storage pressure of 0.7MPa, however, significant air leakage occurred possibly through an open fracture intersecting the chamber just after cavern pressure exceeds the initial hydrostatic pressure at the ceiling level of the chamber. Anomalies

  6. Documentation of the Recirculation in a Closed-Chamber Rotor Hover Test

    Science.gov (United States)

    McCoy, Miranda; Wadcock, Alan J.; Young, Larry A.

    2016-01-01

    A rotor hover test was performed inside the JPL 25-foot-diameter Space Simulator. The 40-inch-diameter rotor was tested at two locations in the chamber-on the chamber centerline and 2m off-axis. The rotor was tested in both upright and inverted configurations for 500 < RPM < 2000. Fluorescent tufts were used to identify regions of recirculation. Velocities on the entrainment side of the rotor were measured. Tabulated values for the mean entrainment velocity components and the corresponding root mean square velocity fluctuations are provided. Unsteady velocity measurements provide a description of the turbulence ingested into the rotor plane and quantify the unsteady velocity field that the Mars Scout Helicopter can expect to encounter during free flight inside the Space Simulator.

  7. Midday stomatal closure in Mediterranean type sclerophylls under simulated habitat conditions in an environmental chamber : II. Effect of the complex of leaf temperature and air humidity on gas exchange of Arbutus unedo and Quercus ilex.

    Science.gov (United States)

    Tenhunen, J D; Lange, O L; Braun, M

    1981-08-01

    Shrubs of the Mediterranean sclerophyllous species Arbutus unedo and Quercus ilex were studied under simulated habitat conditions in an environmental chamber. Temperature, humidity, and light intensity were altered stepwise to simulate diurnal changes in conditions similar to those measured in an evergreen macchia in Sobreda, Portugal. Leaves were enclosed in cuvettes which reproduced the growth chamber climate and which allowed measurement of gas exchange. Increasing atmospheric stress in the form of higher temperature and lower humidity on successive days gradually results in midday depression of transpiration rate and net photosynthesis rate of leaves due to midday stomatal closure.

  8. Laparoscopic-assisted extracorporeal ovarian cystectomy: a new technique.

    Science.gov (United States)

    Ikuma, Kenichino; Amin, Magdy; Yukio, Yamada; Hisato, Okuo; Yoshihiro, Ito; Shintaro, Ueda; Masako, Tanaka; Yasuki, Koyasu

    2004-01-01

    An increasing number of adnexal masses are currently managed laparoscopically, which has hampered progress regarding the different techniques of laparoscopic surgery. In this chapter, a modified application of surgical instrument was described in laparoscopic ovarian cystectomy-we named this device, Lap-Disc Mini. This new instrument has three rings, an inner flexible ring fixed to a middle ring by a rubber corset, and an additional dynamic outer ring that has a rubbery-like iris opening, which allows the application of different-sized trocars and extracorporeal ovarian cystectomy. This technique has proved to be effective and safe, especially in removing large ovarian cyst.

  9. [How can we define the extracorporeal circulation quality?].

    Science.gov (United States)

    Blaffart, F; Defraigne, J-O

    2014-04-01

    Extracorporeal circulation (ECC) has to ensure homeostasis of the patient and to minimize pathophysiological disorders inherent in the technique. However, we cannot dissociate it from the surgery and anesthesia knowing that the discipline involves a close partnership with these stakeholders. The purpose of this publication is to review the essential elements that at present can contribute to the quality of the CEC and suggest improvements and developments to be implemented in this area. Copyright © 2014 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

  10. Extracorporeal respiratory support in adult patients

    Directory of Open Access Journals (Sweden)

    Thiago Gomes Romano

    Full Text Available ABSTRACT In patients with severe respiratory failure, either hypoxemic or hypercapnic, life support with mechanical ventilation alone can be insufficient to meet their needs, especially if one tries to avoid ventilator settings that can cause injury to the lungs. In those patients, extracorporeal membrane oxygenation (ECMO, which is also very effective in removing carbon dioxide from the blood, can provide life support, allowing the application of protective lung ventilation. In this review article, we aim to explore some of the most relevant aspects of using ECMO for respiratory support. We discuss the history of respiratory support using ECMO in adults, as well as the clinical evidence; costs; indications; installation of the equipment; ventilator settings; daily care of the patient and the system; common troubleshooting; weaning; and discontinuation.

  11. Study on superhigh energy γ-ray family events with large-scale Fe emulsion chambers

    International Nuclear Information System (INIS)

    Ren Jingru; Lu Suiling; Su Shi

    1990-01-01

    Using a large-scale iron emulsion chamber, a big γ-ray family event with observed energy ΣE r = 7631 TeV was obtained. This paper described the advantages of iron emulsion chamber for studying big families and the characteristics of the event observed, together with a comparison with the Monte-Carlo simulation results

  12. APOLLO 16 COMMANDER JOHN YOUNG ENTERS ALTITUDE CHAMBER FOR TESTS

    Science.gov (United States)

    1971-01-01

    Apollo 16 commander John W. Young prepares to enter the lunar module in an altitude chamber in the Manned Spacecraft Operations Building at the spaceport prior to an altitude run. During the altitude run, in which Apollo 16 lunar module pilot Charles M. Duke also participated, the chamber was pumped down to simulate pressure at an altitude in excess of 200,000 feet. Young, Duke and command module pilot Thomas K. Mattingly II, are training at the Kennedy Space Center for the Apollo 16 mission. Launch is scheduled from Pad 39A, March 17, 1972.

  13. Bluetooth Communication Interface for EEG Signal Recording in Hyperbaric Chambers.

    Science.gov (United States)

    Pastena, Lucio; Formaggio, Emanuela; Faralli, Fabio; Melucci, Massimo; Rossi, Marco; Gagliardi, Riccardo; Ricciardi, Lucio; Storti, Silvia F

    2015-07-01

    Recording biological signals inside a hyperbaric chamber poses technical challenges (the steel walls enclosing it greatly attenuate or completely block the signals as in a Faraday cage), practical (lengthy cables creating eddy currents), and safety (sparks hazard from power supply to the electronic apparatus inside the chamber) which can be overcome with new wireless technologies. In this technical report we present the design and implementation of a Bluetooth system for electroencephalographic (EEG) recording inside a hyperbaric chamber and describe the feasibility of EEG signal transmission outside the chamber. Differently from older systems, this technology allows the online recording of amplified signals, without interference from eddy currents. In an application of this technology, we measured EEG activity in professional divers under three experimental conditions in a hyperbaric chamber to determine how oxygen, assumed at a constant hyperbaric pressure of 2.8 ATA , affects the bioelectrical activity. The EEG spectral power estimated by fast Fourier transform and the cortical sources of the EEG rhythms estimated by low-resolution brain electromagnetic analysis were analyzed in three different EEG acquisitions: breathing air at sea level; breathing oxygen at a simulated depth of 18 msw, and breathing air at sea level after decompression.

  14. Mechanical prototype of tracking chamber in station 2 in dimuon ...

    Indian Academy of Sciences (India)

    the design and choice of material for the chamber was finalised following the result of the simulation. ... The frames were made from several pieces joined together ... The measured values of the prototype deformation with and without the CPF.

  15. Determination of the air attenuation and electronic loss for the free air concentric cylinders ionization chamber

    International Nuclear Information System (INIS)

    Oliveira, Hebert Pinto Silveira de

    2010-01-01

    Along the latest years, the LNMRI has been proceeding a continuous research work with a concentric cylinders type free air ionizing chamber (VICTOREEN, model 481), aiming to establish it as a new national standard, and, as a consequence, replace the worldwide accepted secondary standard, calibrated by PTB. Taking into account that the absolute determination of kerma in air with a free air ionizing chamber implies the acquirement of a number of correction factors. The main objective of the present work comprises the determination of the two factors, specifically, electronic loss (k e ) and air attenuation (k a ). The correction factors were obtained through mammography qualities reference spectrum, using Monte Carlo simulation method. The Penelope code was used in the simulation procedures. Simulations took place in two stages, the acquirement of specters related to the qualities of interest (mammography) with the x ray tube (Pantak, model HF160 e Panalytical, model XRF window), and the free-air ionization chamber. The data were compared to those related to the BIPM chamber, to electronic loss were not detected. The comparison between air attenuation factors was obtained data bellow 0.13%. (author)

  16. Computational evaluation of the thrombogenic potential of a hollow-fiber oxygenator with integrated heat exchanger during extracorporeal circulation.

    Science.gov (United States)

    Pelosi, Alessandra; Sheriff, Jawaad; Stevanella, Marco; Fiore, Gianfranco B; Bluestein, Danny; Redaelli, Alberto

    2014-04-01

    The onset of thromboembolic phenomena in blood oxygenators, even in the presence of adequate anticoagulant strategies, is a relevant concern during extracorporeal circulation (ECC). For this reason, the evaluation of the thrombogenic potential associated with extracorporeal membrane oxygenators should play a critical role into the preclinical design process of these devices. This study extends the use of computational fluid dynamics simulations to guide the hemodynamic design optimization of oxygenators and evaluate their thrombogenic potential during ECC. The computational analysis accounted for both macro- (i.e., vortex formation) and micro-scale (i.e., flow-induced platelet activation) phenomena affecting the performances of a hollow-fiber membrane oxygenator with integrated heat exchanger. A multiscale Lagrangian approach was adopted to infer the trajectory and loading history experienced by platelet-like particles in the entire device and in a repetitive subunit of the fiber bundles. The loading history was incorporated into a damage accumulation model in order to estimate the platelet activation state (PAS) associated with repeated passes of the blood within the device. Our results highlighted the presence of blood stagnation areas in the inlet section that significantly increased the platelet activation levels in particles remaining trapped in this region. The order of magnitude of PAS in the device was the same as the one calculated for the components of the ECC tubing system, chosen as a term of comparison for their extensive diffusion. Interpolating the mean PAS values with respect to the number of passes, we obtained a straightforward prediction of the thrombogenic potential as a function of the duration of ECC.

  17. Mechanical ventilation during extracorporeal membrane oxygenation. An international survey.

    Science.gov (United States)

    Marhong, Jonathan D; Telesnicki, Teagan; Munshi, Laveena; Del Sorbo, Lorenzo; Detsky, Michael; Fan, Eddy

    2014-07-01

    In patients with severe, acute respiratory failure undergoing venovenous extracorporeal membrane oxygenation (VV-ECMO), the optimal strategy for mechanical ventilation is unclear. Our objective was to describe ventilation practices used in centers registered with the Extracorporeal Life Support Organization (ELSO). We conducted an international cross-sectional survey of medical directors and ECMO program coordinators from all ELSO-registered centers. The survey was distributed using a commercial website that collected information on center characteristics, the presence of a mechanical ventilator protocol, ventilator settings, and weaning practices. E-mails were sent out to medical directors or coordinators at each ELSO center and their responses were pooled for analysis. We analyzed 141 (50%) individual responses from the 283 centers contacted across 28 countries. Only 27% of centers reported having an explicit mechanical ventilation protocol for ECMO patients. The majority of these centers (77%) reported "lung rest" to be the primary goal of mechanical ventilation, whereas 9% reported "lung recruitment" to be their ventilation strategy. A tidal volume of 6 ml/kg or less was targeted by 76% of respondents, and 58% targeted a positive end-expiratory pressure of 6-10 cm H2O while ventilating patients on VV-ECMO. Centers prioritized weaning VV-ECMO before mechanical ventilation. Although ventilation practices in patients supported by VV-ECMO vary across ELSO centers internationally, the majority of centers used a strategy that targeted lung-protective thresholds and prioritized weaning VV-ECMO over mechanical ventilation.

  18. Successful Use of Extracorporeal Membrane Oxygenation for the Treatment of Cardiogenic Shock due to Scorpion Envenomation

    Directory of Open Access Journals (Sweden)

    Amine Tarmiz

    2017-01-01

    Full Text Available Introduction. The occurrence of a cardiogenic shock is a rare presentation after scorpion envenomation. The treatment includes classically the use of inotropes and specific vasodilators. Case Presentation. We report a case of an 11-year-old boy presenting with cardiogenic shock and pulmonary edema after a scorpion sting. Despite adequate management at the emergency department and intensive care unit, the patient’s hemodynamic status worsened rapidly, justifying his transfer to our department for ventricular mechanical assistance by venoarterial extracorporeal membrane oxygenation. The following outcomes were favorable and the boy was discharged home on day 29 without aftereffects. Conclusion. This is the first report of successful use of extracorporeal membrane oxygenation for the treatment of cardiogenic shock after scorpion envenomation.

  19. Venovenous Extracorporeal Membrane Oxygenation in an Adult Patient With Prader-Willi Syndrome: A Nutrition Case Report.

    Science.gov (United States)

    Pelekhaty, Stacy; Menaker, Jay

    2018-03-12

    Prader-Willi Syndrome (PWS) is a genetic condition that results in a constellation of symptoms and typically results in hyperphagia and obesity in adulthood. Critically ill adults with PWS present a unique challenge to the nutrition professional, particularly when they require support modalities such as extracorporeal membrane oxygenation (ECMO). The purpose of this case study is to review the nutrition care of a critically ill adult patient with PWS who required venovenous ECMO. The patient was successfully managed with a hypocaloric, high-protein approach, which did not result in the diagnosis of malnutrition during his hospitalization. The patient was ultimately transitioned off extracorporeal life support and discharged to a rehabilitation facility. © 2018 American Society for Parenteral and Enteral Nutrition.

  20. Peltier-based cloud chamber

    Science.gov (United States)

    Nar, Sevda Yeliz; Cakir, Altan

    2018-02-01

    Particles produced by nuclear decay, cosmic radiation and reactions can be identified through various methods. One of these methods that has been effective in the last century is the cloud chamber. The chamber makes visible cosmic particles that we are exposed to radiation per second. Diffusion cloud chamber is a kind of cloud chamber that is cooled by dry ice. This traditional model has some application difficulties. In this work, Peltier-based cloud chamber cooled by thermoelectric modules is studied. The new model provided uniformly cooled base of the chamber, moreover, it has longer lifetime than the traditional chamber in terms of observation time. This gain has reduced the costs which spent each time for cosmic particle observation. The chamber is an easy-to-use system according to traditional diffusion cloud chamber. The new model is portable, easier to make, and can be used in the nuclear physics experiments. In addition, it would be very useful to observe Muons which are the direct evidence for Lorentz contraction and time expansion predicted by Einsteins special relativity principle.

  1. Predictability of the individual clinical outcome of extracorporeal shock wave therapy for cellulite

    Directory of Open Access Journals (Sweden)

    Schlaudraff KU

    2014-05-01

    Full Text Available Kai-Uwe Schlaudraff,1 Maren C Kiessling,2 Nikolaus BM Császár,2 Christoph Schmitz21Concept Clinic, Geneva, Switzerland; 2Department of Anatomy II, Ludwig-Maximilians-University of Munich, Munich, GermanyBackground: Extracorporeal shock wave therapy has been successfully introduced for the treatment of cellulite in recent years. However, it is still unknown whether the individual clinical outcome of cellulite treatment with extracorporeal shock wave therapy can be predicted by the patient's individual cellulite grade at baseline, individual patient age, body mass index (BMI, weight, and/or height.Methods: Fourteen Caucasian females with cellulite were enrolled in a prospective, single-center, randomized, open-label Phase II study. The mean (± standard error of the mean cellulite grade at baseline was 2.5±0.09 and mean BMI was 22.8±1.17. All patients were treated with radial extracorporeal shock waves using the Swiss DolorClast® device (Electro Medical Systems, S.A., Nyon, Switzerland. Patients were treated unilaterally with 2 weekly treatments for 4 weeks on a randomly selected side (left or right, totaling eight treatments on the selected side. Treatment was performed at 3.5–4.0 bar, with 15,000 impulses per session applied at 15 Hz. Impulses were homogeneously distributed over the posterior thigh and buttock area (resulting in 7,500 impulses per area. Treatment success was evaluated after the last treatment and 4 weeks later by clinical examination, photographic documentation, contact thermography, and patient satisfaction questionnaires.Results: The mean cellulite grade improved from 2.5±0.09 at baseline to 1.57±0.18 after the last treatment (ie, mean δ-1 was 0.93 cellulite grades and 1.68±0.16 at follow-up (ie, mean δ-2 was 0.82 cellulite grades. Compared with baseline, no patient's condition worsened, the treatment was well tolerated, and no unwanted side effects were observed. No statistically significant (ie, P<0

  2. Scattering study at free air ionization chamber diaphragm

    International Nuclear Information System (INIS)

    Santos, Alexandre Lo Bianco dos

    2011-01-01

    The maim of this work consisted in the assessment of the correction factor for air kerma, due to scattered radiation in the diaphragm of the free-air ionization chamber model 481. LNMRl measurements were made to acquire x-ray spectra corresponding to the Qualities RQR-M, described in IEC 61627 standards (2005). These spectra were used as input data in the MC simulations. The operational range of energy spectra provide up to 35 keV. This energy range is typically used in diagnostic radiology, although there is not primary standard for air kerma. The determination of this factor is a fundamental process in the primary standardization of the air kerma. These factors were obtained by computer simulation using the Penelope code. The results are k RQR-M1 =0,9946, k RQR -M2 =0,9932, k RQR-M3 =0,9978 and k RQR-M4 =0,9885; with uncertainties of 0,007 and coverage factor equal to 2. lt can be concluded that, with respect to the diaphragm, the chamber can be used in the primary standard of air kerma. (author)

  3. Ligation of the Rectum with an Extracorporeal Sliding Knot Facilitating Laparoscopic Cross-Stapling

    DEFF Research Database (Denmark)

    Bulut, Orhan

    2013-01-01

    : The extracorporeal ligation of the rectum just proximal to the cut end of the rectum before applying the linear stapling stapler facilitates the procedure and requires only a few firings of the stapler during the laparoscopic rectal resections. Results: Ten patients with a median age of 72 years underwent rectal...

  4. Detailed Measurement of ORSC Main Chamber Injector Dynamics

    Science.gov (United States)

    Bedard, Michael J.

    Improving fidelity in simulation of combustion dynamics in rocket combustors requires an increase in experimental measurement fidelity for validation. In a model rocket combustor, a chemiluminescence based spectroscopy technique was used to capture flame light emissions for direct comparison to a computational simulation of the production of chemiluminescent species. The comparison indicated that high fidelity models of rocket combustors can predict spatio-temporal distribution of chemiluminescent species with trend-wise accuracy. The comparison also indicated the limited ability of OH* and CH* emission to indicate flame heat release. Based on initial spectroscopy experiments, a photomultiplier based chemiluminescence sensor was designed to increase the temporal resolution of flame emission measurements. To apply developed methodologies, an experiment was designed to investigate the flow and combustion dynamics associated with main chamber injector elements typical of the RD-170 rocket engine. A unique feature of the RD-170 injector element is the beveled expansion between the injector recess and combustion chamber. To investigate effects of this geometry, a scaling methodology was applied to increase the physical scale of a single injector element while maintaining traceability to the RD-170 design. Two injector configurations were tested, one including a beveled injector face and the other a flat injector face. This design enabled improved spatial resolution of pressure and light emission measurements densely arranged in the injector recess and near-injector region of the chamber. Experimental boundary conditions were designed to closely replicate boundary conditions in simulations. Experimental results showed that the beveled injector face had a damping effect on pressure fluctuations occurring near the longitudinal resonant acoustic modes of the chamber, implying a mechanism for improved overall combustion stability. Near the injector, the beveled geometry

  5. Linezolid extracorporeal removal during haemodialysis with high cut-off membrane in critically ill patients.

    Science.gov (United States)

    Villa, Gianluca; Cassetta, Maria Iris; Tofani, Lorenzo; Valente, Serafina; Chelazzi, Cosimo; Falsini, Silvia; De Gaudio, Angelo Raffaele; Novelli, Andrea; Ronco, Claudio; Adembri, Chiara

    2015-10-01

    Continuous venovenous haemodialysis with high cut-off membrane (HCO-CVVHD) is often used in critically ill septic patients with acute kidney injury (AKI) to sustain renal function and to remove circulating inflammatory mediators. The aim of this study was to analyse the extracorporeal removal of linezolid and related alterations in pharmacokinetic/pharmacodynamic (PK/PD) parameters during HCO-CVVHD. Three critically ill septic patients with AKI, treated with linezolid and HCO-CVVHD, were prospectively observed. To calculate the extracorporeal clearance of linezolid and the PK parameters, effluent, pre-filter and post-filter samples were contemporaneously collected before linezolid infusion, just after 1-h infusion (maximum serum concentration; C(max)), at 3 h and 6 h after dosing, and before the next dose (trough serum concentration; C(min)). Linezolid C(max) and C(min) (pre-filter) ranged from 10.4-23.5 mg/L and from 2.9-10.3 mg/L. The dialysate saturation coefficient was 0.66-0.85 and the extracorporeal clearance with a diffusive dose of 35 m L/kg/h ranged from 2.1-2.5 L/h. Total linezolid clearance was between 1.7 L/h and 6.3 L/h. The total area under the plasma concentration-time curve (AUC0-∞) ranged from 95.1 mgh/L to 352.9 mgh/L, in accordance with the different clinical conditions. AUCfree/MIC ratios were always linezolid total clearance, the clinical features of critically ill septic patients appear to be mainly responsible for the high variability of linezolid serum concentrations. Copyright © 2015. Published by Elsevier B.V.

  6. Analysis of Heat Stress and the Indoor Climate Control Requirements for Movable Refuge Chambers.

    Science.gov (United States)

    Hao, Xiaoli; Guo, Chenxin; Lin, Yaolin; Wang, Haiqiao; Liu, Heqing

    2016-05-20

    Movable refuge chambers are a new kind of rescue device for underground mining, which is believed to have a potential positive impact on reducing the rate of fatalities. It is likely to be hot and humid inside a movable refuge chamber due to the metabolism of trapped miners, heat generated by equipment and heat transferred from outside. To investigate the heat stress experienced by miners trapped in a movable refuge chamber, the predicted heat strain (PHS) model was used to simulate the heat transfer process between the person and the thermal environment. The variations of heat stress with the temperature and humidity inside the refuge chamber were analyzed. The effects of air temperature outside the refuge chamber and the overall heat transfer coefficient of the refuge chamber shell on the heat stress inside the refuge chamber was also investigated. The relationship between the limit of exposure duration and the air temperature and humidity was numerically analyzed to determine the upper limits of temperature and humidity inside a refuge chamber. Air temperature of 32 °C and relative humidity of 70% are recommended as the design standard for internal thermal environment control of movable refuge chambers.

  7. Analysis of Heat Stress and the Indoor Climate Control Requirements for Movable Refuge Chambers

    Directory of Open Access Journals (Sweden)

    Xiaoli Hao

    2016-05-01

    Full Text Available Movable refuge chambers are a new kind of rescue device for underground mining, which is believed to have a potential positive impact on reducing the rate of fatalities. It is likely to be hot and humid inside a movable refuge chamber due to the metabolism of trapped miners, heat generated by equipment and heat transferred from outside. To investigate the heat stress experienced by miners trapped in a movable refuge chamber, the predicted heat strain (PHS model was used to simulate the heat transfer process between the person and the thermal environment. The variations of heat stress with the temperature and humidity inside the refuge chamber were analyzed. The effects of air temperature outside the refuge chamber and the overall heat transfer coefficient of the refuge chamber shell on the heat stress inside the refuge chamber was also investigated. The relationship between the limit of exposure duration and the air temperature and humidity was numerically analyzed to determine the upper limits of temperature and humidity inside a refuge chamber. Air temperature of 32 °C and relative humidity of 70% are recommended as the design standard for internal thermal environment control of movable refuge chambers.

  8. Apneic oxygenation combined with extracorporeal arteriovenous carbon dioxide removal provides sufficient gas exchange in experimental lung injury

    DEFF Research Database (Denmark)

    Nielsen, Niels Dalsgaard; Kjærgaard, Benedict; Koefoed-Nielsen, Jacob

    2008-01-01

    We hypothesized that apneic oxygenation, using an open lung approach, combined with extracorporeal CO2 removal, would provide adequate gas exchange in acute lung injury. We tested this hypothesis in nine anesthetized and mechanically ventilated pigs (85-95 kg), in which surfactant was depleted fr....../min. Thus, the method provided adequate gas exchange in this experimental model, suggesting that it might have potential as an alternative treatment modality in acute lung injury.......We hypothesized that apneic oxygenation, using an open lung approach, combined with extracorporeal CO2 removal, would provide adequate gas exchange in acute lung injury. We tested this hypothesis in nine anesthetized and mechanically ventilated pigs (85-95 kg), in which surfactant was depleted from...

  9. Investigation of electron-loss and photon scattering correction factors for FAC-IR-300 ionization chamber

    Science.gov (United States)

    Mohammadi, S. M.; Tavakoli-Anbaran, H.; Zeinali, H. Z.

    2017-02-01

    The parallel-plate free-air ionization chamber termed FAC-IR-300 was designed at the Atomic Energy Organization of Iran, AEOI. This chamber is used for low and medium X-ray dosimetry on the primary standard level. In order to evaluate the air-kerma, some correction factors such as electron-loss correction factor (ke) and photon scattering correction factor (ksc) are needed. ke factor corrects the charge loss from the collecting volume and ksc factor corrects the scattering of photons into collecting volume. In this work ke and ksc were estimated by Monte Carlo simulation. These correction factors are calculated for mono-energy photon. As a result of the simulation data, the ke and ksc values for FAC-IR-300 ionization chamber are 1.0704 and 0.9982, respectively.

  10. Semi-empirical approach for calibration of CR-39 detectors in diffusion chambers for radon measurements

    International Nuclear Information System (INIS)

    Pereyra A, P.; Lopez H, M. E.; Palacios F, D.; Sajo B, L.; Valdivia, P.

    2016-10-01

    Simulated and measured calibration of PADC detectors is given for cylindrical diffusion chambers employed in environmental radon measurements. The method is based on determining the minimum alpha energy (E min ), average critical angle (<Θ c >), and fraction of 218 Po atoms; the volume of the chamber (f 1 ), are compared to commercially available devices. Radon concentration for exposed detectors is obtained from induced track densities and the well-established calibration coefficient for NRPB monitor. Calibration coefficient of a PADC detector in a cylindrical diffusion chamber of any size is determined under the same chemical etching conditions and track analysis methodology. In this study the results of numerical examples and comparison between experimental calibration coefficients and simulation purpose made code. Results show that the developed method is applicable when uncertainties of 10% are acceptable. (Author)

  11. Dual ionization chamber

    International Nuclear Information System (INIS)

    Mallory, J.; Turlej, Z.

    1981-01-01

    Dual ionization chambers are provided for use with an electronic smoke detector. The chambers are separated by electrically-conductive partition. A single radiation source extends through the partition into both chambers, ionizing the air in each. The mid-point current of the device may be balanced by adjusting the position of the source

  12. Role of Epinephrine and Extracorporeal Membrane Oxygenation in the Management of Ischemic Refractory Ventricular Fibrillation

    Directory of Open Access Journals (Sweden)

    Jason A. Bartos, MD, PhD

    2017-06-01

    Full Text Available Summary: Extracorporeal membrane oxygenation (ECMO is used in cardiopulmonary resuscitation (CPR of refractory cardiac arrest. The authors used a 2 × 2 study design to compare ECMO versus CPR and epinephrine versus placebo in a porcine model of ischemic refractory ventricular fibrillation (VF. Pigs underwent 5 min of untreated VF and 10 min of CPR, and were randomized to receive epinephrine versus placebo for another 35 min. Animals were further randomized to left anterior descending artery (LAD reperfusion at minute 45 with ongoing CPR versus venoarterial ECMO cannulation at minute 45 of CPR and subsequent LAD reperfusion. Four-hour survival was improved with ECMO whereas epinephrine showed no effect. Key Words: advanced cardiopulmonary life support, cardiac arrest, cardiopulmonary resuscitation, ECMO, extracorporeal membrane oxygenation, ischemic refractory ventricular fibrillation, ST-segment elevation myocardial infarction, ventricular fibrillation

  13. Two decades' experience with interfacility transport on extracorporeal membrane oxygenation.

    Science.gov (United States)

    Bryner, Benjamin; Cooley, Elaine; Copenhaver, William; Brierley, Kristin; Teman, Nicholas; Landis, Denise; Rycus, Peter; Hemmila, Mark; Napolitano, Lena M; Haft, Jonathan; Park, Pauline K; Bartlett, Robert H

    2014-10-01

    Interfacility transport of patients on extracorporeal membrane oxygenation (ECMO) has been performed in large numbers at only a few programs. Limited data are available on outcomes after ECMO transport to justify expanding or discontinuing these programs. This was a retrospective review of a 20-year, single-institution experience with interhospital ECMO transport as well as a systematic review of reports of transfers of patients on ECMO. Results of both were compared with historical data from the international registry of the Extracorporeal Life Support Organization (ELSO). Between 1990 and 2012, ECMO was used to facilitate transport of 221 patients to our institution, and 135 (62%) survived to discharge. Review of an additional 27 case series describing ECMO transport of 643 patients showed an overall survival of 61%. After stratifying by age and primary indication for ECMO, survival of transported patients was not significantly different compared with all ECMO patients in the ELSO registry, with the exception of pediatric patients treated for respiratory failure (transported patients in this category had higher survival than those in the ELSO registry). Interfacility transport on ECMO is feasible and can be accomplished safely in the critically ill. Survival of transported patients is comparable to age-matched and treatment-matched ECMO patients at large. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Verifying the capability of a recombination chamber in a mixed field

    International Nuclear Information System (INIS)

    Mayer, S.; Mitaroff, A.; Golnik, N.; Aiginger, H.

    2003-01-01

    Dosimetry in stray radiation fields outside the shielding of hadron accelerators is a difficult task due to the complex nature of the radiation field. An instrument desirable in operational health physics should measure dose equivalent of any composition of radiation components in the entire energy range. A promising candidate for single detector dosimetry in complex radiation fields is a recombination chamber. Performance of a REM-2 recombination chamber was investigated at the CERN-EU high-energy Reference Field (CERF) facility of CERN. The sum of dose equivalents measured with detectors sensitive to only one component of the mixed radiation field was compared with the total dose equivalent obtained with the recombination chamber. In addition the results were compared with Monte Carlo (MC) simulations. (authors)

  15. CFD analysis of premixed hydrogen/air combustion in an upright, rectangular shaped combustion chamber

    International Nuclear Information System (INIS)

    Gera, B.; Singh, R.K.; Vaze, K.K.

    2014-01-01

    Premixed hydrogen/air combustion in an upright, rectangular shaped combustion chamber has been performed numerically using commercial CFD code CFD-ACE+. The combustion chamber had dimensions 1 m X 0.024 m X 1 m. Simulations were carried out for 10% (v/v) hydrogen concentration for which experimental results were available. Effect of different boundary condition and ignition position on flame propagation was studied. Time dependent flame propagation in the chamber was predicted by CFD code. The computed transient flame propagation in the chamber was in good agreement with experimental results. The present work demonstrated that the available commercial CFD codes are capable of modeling hydrogen deflagration in a realistic manner. (author)

  16. Cupriavidus pauculus bacteremia in a child on extracorporeal membrane oxygenation.

    Science.gov (United States)

    Uzodi, Adaora S; Schears, Gregory J; Neal, James R; Henry, Nancy K

    2014-01-01

    We report a case of bacteremia secondary to Cupriavidus pauculus in a 15-month-old boy on extracorporeal membrane oxygenation (ECMO). The source of the organism was water in the thermoregulator reservoir. The child responded well to cefepime and ciprofloxacin, a delayed oxygenator change out and replacement of the thermoregulator reservoir with a unit that was cleaned and decontaminated with sodium hypochlorite. Isolation of Cupriavidus pauculus from a patient on ECMO support should raise suspicion of the reservoir as a source.

  17. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  18. Wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  19. Uniform, stable supply of medium for in vitro cell culture using a robust chamber

    Science.gov (United States)

    Wei, Juan; Liu, Chong; Jiang, Yang; Liu, Tao; Chen, Li; Liu, Bo; Li, Jingmin

    2018-06-01

    A uniform, stable supply of medium is important for in vitro cell culture. In this paper, a microfluidic device is presented for culturing cells inside a robust chamber with continuous perfusion of medium. The device consists of a main channel, two bifurcated channels and a culture chamber. The culture chamber connects to the bifurcated channels via multiple paths, and distributes symmetrically on the main channel, to improve the efficiency of medium exchange. Furthermore, regular polygonal chambers with various numbers of edges have been designed, to study the effects of chamber shape on flow fields. The finite element method has been employed to predict the effects of multiple paths on the uniformity and stability of flow fields in the culture chamber. Particle tracking technology has been used to evaluate the flow fields in the chambers, and PC-12 cells have been cultured using the microfluidic device, to test its validity. The results of simulation and experiment indicate that the microfluidic design could provide a continuous interstitial-like flow microenvironment, with a relatively stable and uniform supply of medium.

  20. Scaling of the flow field in a combustion chamber with a gas–gas injector

    International Nuclear Information System (INIS)

    Xiao-Wei, Wang; Guo-Biao, Cai; Ping, Jin

    2010-01-01

    The scaling of the flow field in a gas–gas combustion chamber is investigated theoretically, numerically and experimentally. To obtain the scaling criterion of the gas–gas combustion flowfield, formulation analysis of the three-dimensional (3D) Navier–Stokes equations for a gaseous multi-component mixing reaction flow is conducted and dimensional analysis on the gas–gas combustion phenomena is also carried out. The criterion implies that the size and the pressure of the gas–gas combustion chamber can be changed. Based on the criterion, multi-element injector chambers with different geometric sizes and at different chamber pressures ranging from 3 MPa to 20 MPa are numerically simulated. A multi-element injector chamber is designed and hot-fire tested at five chamber pressures from 1.64 MPa to 3.68 MPa. Wall temperature measurements are used to understand the similarity of combustion flowfields in the tests. The results have verified the similarities between combustion flowfields under different chamber pressures and geometries, with the criterion applied. (geophysics, astronomy and astrophysics)

  1. Alterations of blood and blood coagulation by extracorporeal irradiation in leukemia and radiophosphor therapy in polycythemia

    International Nuclear Information System (INIS)

    Huhn, D.; Kaboth, W.; Theml, H.; Murr, H.; Schramm, W.; Leisner, B.

    1974-01-01

    Animal experiments prove a high radiation resistance of megakaryocytes and thrombocytes. Radiophosphorus is thought to influence mainly the megakaryocytes in their beginnings; an effect on the vessel system of the bone marrow is particularly to be discussed in the case of very early and quickly reversible drop in thrombocytes. In the very first week after radiophosphorus administration, a considerable drop in thrombocytes is already seen in some patients, the number of patients remaining the same during the following 3 weeks. After blood irradiation, the thrombocytes are for a certain period reduced due to the influence of the extracorporal circulation, but in general their number increases again during the following months. A considerable disfunction of the thrombocytes or a disturbed coagulation is not found either after radiophosphorus treatment or after extracorporal blood irradiation. (orig.) [de

  2. Establishment of extracorporeal circulation of artificial liver support system in high altitude region

    Directory of Open Access Journals (Sweden)

    Ming-sen ZHANG

    2011-01-01

    Full Text Available Objective To establish extracorporeal circulation in big animal suitable for the research on artificial liver support system in high altitude region.Methods Under the anesthesia of ketamine hydrochloride/diazepam IV,cannulation of common carotid artery/external jugular vein(n=3 and inferior vena cava via the left external jugular vein/right external jugular vein(n=3,was respectively performed on six healthy Chang-Bai piglets adapted to native environment(altitude 3700m.One day after that,the extracorporeal circulation was performed at a progressively elevated blood current velocity,and the general condition of the animals,blood pressure,HR,bleeding tendoncy of the experimental pigs and coagulation in the cannulae were observed.Results On the premise that the hemodynamics was not influenced,the highest blood current velocity was 133.33±28.87ml/min,the lowest heparin maintaining speed amounted to 138.67±12.22mg/h,and the bleeding tendency and blood coagulation in the cannula was significant in the group of common carotid artery/external jugular vein intubation.While the highest blood current velocity was 400ml/min,the lowest heparin maintaining speed was 26.67±9.24mg/h,no bleeding tendency or obvious cannular blood coagulation were observed in the group of cannulation of inferior vena cava via the left external jugular vein/right external jugular vein.These untoward results were significantly less or slight than that of the former group(P < 0.01.Conclusion It is suitable to perform research of artificial liver support system on piglets in high altitude region by establishing extracorporeal circulation by the way of inferior vena cava with cannulation passing through the left external jugular vein/right external jugular vein with the blood current velocity of 400ml/min.

  3. Design of the free-air ionization chamber, FAC-IR-150, for X-ray dosimetry

    Science.gov (United States)

    Mohammadi, Seyed Mostafa; Tavakoli-Anbaran, Hossein

    2018-03-01

    The primary standard for X-ray dosimetry is based on the free-air ionization chamber (FAC). Therefore, the Atomic Energy Organization of Iran (AEOI) designed the free-air ionization chamber, FAC-IR-150, for low and medium energy X-ray dosimetry. The purpose of this work is the study of the free-air ionization chamber characteristics and the design of the FAC-IR-150. The FAC-IR-150 dosimeter has two parallel plates, a high voltage plate and a collector plate. A guard electrode surrounds the collector and is separated by an air gap. A group of guard strips is used between up and down electrodes to produce a uniform electric field in all the ion chamber volume. This design involves introducing the correction factors and determining the exact dimensions of the ionization chamber by using Monte Carlo simulation.

  4. Study of the collecting electrode material of an extrapolation chamber by Monte Carlo simulation; Estudo do material do eletrodo coletor de uma câmara de extrapolação por simulação de Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Vedovato, Uly Pita; Santos, William S.; Perini, Ana Paula, E-mail: anapaula.perini@ufu.br [Universidade Federal de Uberlândia (INFIS/UFU), Uberlândia, MG (Brazil). Instituto de Física; Neves, Lucio Pereira; Caldas, Linda V. E. [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Belinato, Walmir [Instituto Federal de Educação, Ciência e Tecnologia da Bahia (IFBA), Vitória da Conquista, BA (Brazil)

    2017-07-01

    In this work, the influence of different materials of the collecting electrode on the response of an extrapolation ionization chamber, was evaluated. This ionization chamber was simulated with the MCNP-4C Monte Carlo code and the spectrum of a standard diagnostic radiology beam (RQR5) was utilized. The different results are due to interactions of photons with different materials of the collecting electrode contributing with different values of energy deposited in the sensitive volume of the ionization chamber, which depends on the atomic number of the evaluated materials. The material that presented the least influence was graphite, the original constituent of the ionization chamber. (author)

  5. Ionization chambers

    International Nuclear Information System (INIS)

    Boag, J.W.

    1987-01-01

    Although a variety of solid-state and chemical methods for measuring radiation dose have been developed in recent decades and calorimetry can now provide an absolute standard of reference, ionization dosimetry retains its position as the most widely used, most convenient, and, in most situations, most accurate method of measuring either exposure or absorbed dose. The ionization chamber itself is the central element in this system of dosimetry. In this chapter the principles governing the construction and operation of ionization chambers of various types are examined. Since the ionization chambers now in general use are nearly all of commercial manufacture, the emphasis is on operating characteristics and interpretation of measurements rather than on details of construction, although some knowledge of the latter is often required when applying necessary corrections to the measured quantities. Examples are given of the construction of typical chambers designed for particular purposes, and the methods of calibrating them are discussed

  6. Blood leukocyte responses to extracorporeal circulation. 3. Long term extracorporeal circulation without and with irradiation in normal and splenectomized dogs

    Energy Technology Data Exchange (ETDEWEB)

    Szemere, P.; Fliedner, T.M. (Ulm Univ. (Germany, F.R.). Abt. Klinische Physiologie)

    1983-01-01

    Long term (12-48 h) extracorporeal circulation without and with irradiation of the blood was performed in normal and splenectomized dogs in order to observe the effect of these procedures on blood leukocyte counts including CFU-C. A transient granulocytopenia and a decrease of lymphocyte count were observed. The blood CFU-C level diminished to a very low level and remained low for the whole time of the experiments. There was no significant difference between the results of procedures with or without irradiation. The similar effect of a shortened tubing system on the blood leukocyte count is also reported. Heparin infusion alone did not decrease the peripheral CFU-C concentration. The possible explanations for the observed phenomena are discussed.

  7. Investigation of electron-loss and photon scattering correction factors for FAC-IR-300 ionization chamber

    International Nuclear Information System (INIS)

    Mohammadi, S.M.; Tavakoli-Anbaran, H.; Zeinali, H.Z.

    2017-01-01

    The parallel-plate free-air ionization chamber termed FAC-IR-300 was designed at the Atomic Energy Organization of Iran, AEOI. This chamber is used for low and medium X-ray dosimetry on the primary standard level. In order to evaluate the air-kerma, some correction factors such as electron-loss correction factor (k e ) and photon scattering correction factor (k sc ) are needed. k e factor corrects the charge loss from the collecting volume and k sc factor corrects the scattering of photons into collecting volume. In this work k e and k sc were estimated by Monte Carlo simulation. These correction factors are calculated for mono-energy photon. As a result of the simulation data, the k e and k sc values for FAC-IR-300 ionization chamber are 1.0704 and 0.9982, respectively.

  8. Semi-empirical approach for calibration of CR-39 detectors in diffusion chambers for radon measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pereyra A, P.; Lopez H, M. E. [Pontificia Universidad Catolica del Peru, Av. Universitaria 1801, San Miguel Lima 32 (Peru); Palacios F, D.; Sajo B, L. [Universidad Simon Bolivar, Laboratorio de Fisica Nuclear, Apartado 89000 Caracas (Venezuela, Bolivarian Republic of); Valdivia, P., E-mail: ppereyr@pucp.edu.pe [Universidad Nacional de Ingenieria, Av. Tupac Amaru s/n, Rimac, Lima 25 (Peru)

    2016-10-15

    Simulated and measured calibration of PADC detectors is given for cylindrical diffusion chambers employed in environmental radon measurements. The method is based on determining the minimum alpha energy (E{sub min}), average critical angle (<Θ{sub c}>), and fraction of {sup 218}Po atoms; the volume of the chamber (f{sub 1}), are compared to commercially available devices. Radon concentration for exposed detectors is obtained from induced track densities and the well-established calibration coefficient for NRPB monitor. Calibration coefficient of a PADC detector in a cylindrical diffusion chamber of any size is determined under the same chemical etching conditions and track analysis methodology. In this study the results of numerical examples and comparison between experimental calibration coefficients and simulation purpose made code. Results show that the developed method is applicable when uncertainties of 10% are acceptable. (Author)

  9. Extracorporeal shockwave therapy for patellar tendinopathy: a review of the literature

    OpenAIRE

    van Leeuwen, M. T.; Zwerver, J.; van den Akker-Scheek, I.

    2009-01-01

    Background and purpose: Extracorporeal shockwave therapy (EWST) has become a popular treatment for patellar tendinopathy. The purpose of this review was to study the effectiveness of ESWT treatment for patellar tendinopathy; to draft guidelines for an effective treatment protocol of ESWT treatment; and to identify topics for further research. Methods: A computerised search of the Medline and Embase databases was conducted on 1 August 2007, to identify studies dealing with the effectiveness of...

  10. Extracorporeal Shock-wave Lithotripsy Success Rate and Complications: Initial Experience at Sultan Qaboos University Hospital

    Directory of Open Access Journals (Sweden)

    Mohammed S. Al-Marhoon

    2013-07-01

    Full Text Available Objective: To assess the efficacy and safety of extracorporeal shock wave lithotripsy with Modularis Vario Siemens in the management of patients with renal and ureteral stones.Methods: Between 2007 and 2009, 225 outpatients were treated with Siemens Modularis Vario lithotripter at Sultan Qaboos University Hospital. Stone size, location, total number of shockwaves, stone-free rate, complications and adjunctive interventions were investigated. Chi-Square and Logistic Regression analyses were used, with p<0.05 set as the level of significance.Results: Of the 225 initial consecutive patients who underwent extracorporeal shock wave lithotripsy, 192 (85% had renal stones and 33 (15% had ureteric stones. The mean±SD stone size was 11.3 ± 4.5 mm, while the mean age of the patients was 39.9 ± 12.8 years with 68.5% males. The mean renal stone size was 11.6 ± 4.7 mm; a mean of 1.3 sessions was required. The mean ureteric stone size was 9.9 ± 3 mm; and a mean of 1.3 sessions was required. Treatment success (defined as complete clearance of ureteric stones, stone-free or clinically insignificant residual fragments of <4 mm for renal stones was 74% for renal stones and 88% for ureteric stones. Additional extracorporeal shock wave lithotripsy and ureteroscopy were the most adjunctive procedures used for stone clearance. Complications occurred in 74 patients (38.5% with renal stones and 13 patients (39.4% with uretetric stones. The most common complication was loin pain (experienced by 16.7% with renal stones and 21% with ureteric stones. Severe renal colic mandating admission occurred in 2% of patients with renal stones and 6% of patients with ureteric stones. In patients with renal stone, steinstrasse occurred in 3.6% and infection post extracorporeal shock wave lithotripsy in 0.5%. Using Multivariate Logistic Regression analysis, factors found to have significant effect on complete stone clearance were serum creatinine (p=0.004 and the number of

  11. Gas microstrip chambers

    International Nuclear Information System (INIS)

    McIntyre, P.M.; Barasch, E.F.; Bowcock, T.J.V.; Demroff, H.P.; Elliott, S.M.; Howe, M.R.; Lee, B.; Mazumdar, T.K.; Pang, Y.; Smith, D.D.; Wahl, J.; Wu, Y.; Yue, W.K.; Gaedke, R.M.; Vanstraelen, G.

    1992-01-01

    The gas microstrip chamber has been developed from concept to experimental system during the past three years. A pattern of anode and grid lines are microfabricated onto a dielectric substrate and configured as a high-resolution MWPC. Four recent developments are described: Suitable plastic substrates and lithography techniques for large-area chambers; non-planar silicon-based chambers for 20 μm resolution; integrated on-board synchronous front-end electronics and data buffering; and a porous silicon active cathode for enhanced efficiency and time response. The microstrip chamber appears to be a promising technology for applications in microvertex, tracking spectrometer, muon spectrometer, and transition radiation detection. (orig.)

  12. Leucocyte depletion in a drowning victim during rewarming with extracorporeal circulation may limit pulmonary oedema

    NARCIS (Netherlands)

    Vermeijden, Wytze J.; de Vries, Hans; Kieboom, Joke; Waterbolk, Tjalling

    2006-01-01

    We report two drowning victims with hypothermic circulatory arrest who were resuscitated with the use of extracorporeal circulation (ECC). The first patient developed severe post-bypass pulmonary oedema and inspired us to use a leucocyte-depletion filter in the second patient to attenuate

  13. Cytoflavin as an Additional Method for Myocardial Salvage During Operations Under Extracorporeal Circulation

    Directory of Open Access Journals (Sweden)

    Z. Z Nadiradze

    2006-01-01

    Full Text Available The paper presents the results of use of the combined antihypoxant Cytoflavin during operations under extracorporeal circulation. Twenty-nine patients operated on for rheumatic mitral valvular disease were examined. The examinations have shown that the use of Cytoflavin positively affects the restoration of cardiovascular performance and improved tissue oxygen transport in the postperfusion period.

  14. Double chamber ion source

    International Nuclear Information System (INIS)

    Uman, M.F.; Winnard, J.R.; Winters, H.F.

    1978-01-01

    The ion source is comprised of two discharge chambers one of which is provided with a filament and an aperture leading into the other chamber which in turn has an extraction orifice. A low voltage arc discharge is operated in an inert gas atmosphere in the filament chamber while an arc of higher voltage is operated in the second ionization chamber which contains a vapor which will give the desired dopant ion species. The entire source is immersed in an axial magnetic field parallel to a line connecting the filament, the aperture between the two chambers and the extraction orifice. (author)

  15. Europlanet Research Infrastructure: Planetary Simulation Facilities

    Science.gov (United States)

    Davies, G. R.; Mason, N. J.; Green, S.; Gómez, F.; Prieto, O.; Helbert, J.; Colangeli, L.; Srama, R.; Grande, M.; Merrison, J.

    2008-09-01

    EuroPlanet The Europlanet Research Infrastructure consortium funded under FP7 aims to provide the EU Planetary Science community greater access for to research infrastructure. A series of networking and outreach initiatives will be complimented by joint research activities and the formation of three Trans National Access distributed service laboratories (TNA's) to provide a unique and comprehensive set of analogue field sites, laboratory simulation facilities, and extraterrestrial sample analysis tools. Here we report on the infrastructure that comprises the second TNA; Planetary Simulation Facilities. 11 laboratory based facilities are able to recreate the conditions found in the atmospheres and on the surfaces of planetary systems with specific emphasis on Martian, Titan and Europa analogues. The strategy has been to offer some overlap in capabilities to ensure access to the highest number of users and to allow for progressive and efficient development strategies. For example initial testing of mobility capability prior to the step wise development within planetary atmospheres that can be made progressively more hostile through the introduction of extreme temperatures, radiation, wind and dust. Europlanet Research Infrastructure Facilties: Mars atmosphere simulation chambers at VUA and OU These relatively large chambers (up to 1 x 0.5 x 0.5 m) simulate Martian atmospheric conditions and the dual cooling options at VUA allows stabilised instrument temperatures while the remainder of the sample chamber can be varied between 220K and 350K. Researchers can therefore assess analytical protocols for instruments operating on Mars; e.g. effect of pCO2, temperature and material (e.g., ± ice) on spectroscopic and laser ablation techniques while monitoring the performance of detection technologies such as CCD at low T & variable p H2O & pCO2. Titan atmosphere and surface simulation chamber at OU The chamber simulates Titan's atmospheric composition under a range of

  16. Ussing Chamber

    NARCIS (Netherlands)

    Westerhout, J.; Wortelboer, H.; Verhoeckx, K.

    2015-01-01

    The Ussing chamber system is named after the Danish zoologist Hans Ussing, who invented the device in the 1950s to measure the short-circuit current as an indicator of net ion transport taking place across frog skin (Ussing and Zerahn, Acta Physiol Scand 23:110-127, 1951). Ussing chambers are

  17. DELPHI Barrel Muon Chamber Module

    CERN Multimedia

    1989-01-01

    The module was used as part of the muon identification system on the barrel of the DELPHI detector at LEP, and was in active use from 1989 to 2000. The module consists of 7 individual muons chambers arranged in 2 layers. Chambers in the upper layer are staggered by half a chamber width with respect to the lower layer. Each individual chamber is a drift chamber consisting of an anode wire, 47 microns in diameter, and a wrapped copper delay line. Each chamber provided 3 signal for each muon passing through the chamber, from which a 3D space-point could be reconstructed.

  18. Symptomatic gallbladder stones. Cost-effectiveness of treatment with extracorporeal shock-wave lithotripsy, conventional and laparoscopic cholecystectomy

    NARCIS (Netherlands)

    Go, P. M.; Stolk, M. F.; Obertop, H.; Dirksen, C.; van der Elst, D. H.; Ament, A.; van Erpecum, K. J.; van Berge Henegouwen, G. P.; Gouma, D. J.

    1995-01-01

    In order to strike the most favorable balance between health benefits and costs, three treatment modalities for symptomatic cholelithiasis were compared in a cost-effectiveness study: extracorporeal shock-wave lithotripsy (ESWL), conventional cholecystectomy (CC), and laparoscopic cholecystectomy

  19. Radiation exposure to patients during extracorporeal shock wave lithotripsy

    International Nuclear Information System (INIS)

    Marti, J.M.; Robles, J.E.; Arbizu, J.; Castro, F. de; Berian, J.M.; Richter, J.A.

    1992-01-01

    We analyzed the radiological exposure to patients during Extracorporeal Shock Wave Lithotripsy (ESWL) using a second generator lithotriptor. Stone location is accomplished by fluoroscopy and 'quick pics' or snapshots. A prospective study over 55 patients showed a mean exposure of 32.2 R. The introduction of the ALARA criterion reduced it to 16.1 R in the following 145 patients. Mean radiation exposure to patient varies according to treatment difficulty. A mean increase of radiation exposure of 1.6 between low and high difficulty treatment groups was observed. This variation was about 96% when the physician who performed the treatment was considered. (author)

  20. Technological advances in extracorporeal membrane oxygenation for respiratory failure.

    Science.gov (United States)

    Rehder, Kyle J; Turner, David A; Bonadonna, Desiree; Walczak, Richard J; Rudder, Robert J; Cheifetz, Ira M

    2012-08-01

    Extracorporeal membrane oxygenation (ECMO) for neonatal and pediatric cardiac and/or respiratory failure is well established, and its use for adult respiratory failure is rapidly increasing. Management strategies developed over the past 30 years coupled with significant recent technological advances have led to improved ECMO survival. These new technologies are expanding the potential applications for ECMO in exciting ways, including new patient populations and the ability to make ECMO mobile for both intra- and inter-hospital transport. In this article, we highlight some of the recent technological advances and their impact on the utilization of ECMO in increasingly diverse patient populations.

  1. ANAEROBIC DIGESTION MODEL ANALYSIS OF THE FERMENTATION PROCESS IN PSYCHROPHILIC AND MESOPHILIC CHAMBER IN ACCORDANCE WITH THE AMOUNT OF BIOGAS SOURCED

    Directory of Open Access Journals (Sweden)

    Dariusz Zdebik

    2015-03-01

    Full Text Available The paper presents problems concerning the modelling of anaerobic sludge stabilization, with the additional substrate (waste transported, dairy butchery sewage in psychrophilic fermentation conditions in the range 10–20 °C and mesophilic at 35 °C. Simulation test was conducted in the two digesters. Results of the study allowed to evaluate the effectiveness of conducting these processes in separate chambers, i.e. the psychrophilic and mesophilic chamber. During the simulations, terms of obtaining volatile fatty acids and biogas in conjunction with the operating conditions of the chambers indicated.

  2. Measurement of resonance modes causative of beam position monitor signal noise in vacuum chamber of storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Youngdo; Hwang, Ilmoon; Park, Sungju [Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Kim, Changbum, E-mail: chbkim@postech.ac.k [Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

    2011-05-11

    It is known that the position reading obtained from the beam position monitor (BPM) mounted at the storage ring can be corrupted by the resonance mode. We carried out a three dimensional finite-difference time-domain (FDTD) simulation of vacuum chambers of the storage ring of the Pohang Light Source (PLS) without simplified modeling to measure the frequencies of resonance modes excited in the vacuum chamber. The frequencies of resonance modes obtained by the eigenmode simulation are well matched with the peak frequencies of RF transmission scattering matrix (S{sub 21}) graph of sector vacuum chamber measured using a network analyzer. It is found that a transverse electric (TE) resonance mode exists in the operation frequency band of BPM and the vertically oriented electric field of TE resonance mode is linked to the BPM position reading noise. Based on this study, we can easily design a vacuum chamber free from the BPM position reading noise caused by the TE resonance mode.

  3. Measurement of resonance modes causative of beam position monitor signal noise in vacuum chamber of storage ring

    International Nuclear Information System (INIS)

    Joo, Youngdo; Hwang, Ilmoon; Park, Sungju; Kim, Changbum

    2011-01-01

    It is known that the position reading obtained from the beam position monitor (BPM) mounted at the storage ring can be corrupted by the resonance mode. We carried out a three dimensional finite-difference time-domain (FDTD) simulation of vacuum chambers of the storage ring of the Pohang Light Source (PLS) without simplified modeling to measure the frequencies of resonance modes excited in the vacuum chamber. The frequencies of resonance modes obtained by the eigenmode simulation are well matched with the peak frequencies of RF transmission scattering matrix (S 21 ) graph of sector vacuum chamber measured using a network analyzer. It is found that a transverse electric (TE) resonance mode exists in the operation frequency band of BPM and the vertically oriented electric field of TE resonance mode is linked to the BPM position reading noise. Based on this study, we can easily design a vacuum chamber free from the BPM position reading noise caused by the TE resonance mode.

  4. Simulations in the Analysis of Experimental Data Measured by BM@N Drift Chambers

    Science.gov (United States)

    Fedorišin, Ján

    2018-02-01

    The drift chambers (DCH's) are an important part of the tracking system of the BM@N experiment designed to study the production of baryonic matter at the Nuclotron energies. The method of particle hit and track reconstruction in the drift chambers has been already proposed and tested on the BM@N deuteron beam data. In this study the DCH's are first locally and globally aligned, and subsequently the consistency of the track reconstruction chain is tested by two methods. The first one is based on the backward extrapolation of the DCH reconstructed deuteron beam to a position where its deflection in the BM@N magnetic field begins. The second method reconstructs the deuteron beam momentum through its deflection angle. Both methods confirm correctness of the track reconstruction algorithm.

  5. Gridded ionization chamber

    International Nuclear Information System (INIS)

    Houston, J.M.

    1977-01-01

    An improved ionization chamber type x-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is disposed adjacent the anode and is maintained at a voltsge intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting toward the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

  6. Early Activation of Patients after Surgery for Coronary Heart Disease under Extracorporeal Circulation

    Directory of Open Access Journals (Sweden)

    I. A. Kozlov

    2008-01-01

    Full Text Available Objective: to analyze the safety and clinical efficiency of early activation of patients operated on for coronary heart disease under extracorporeal circulation. Subjects and methods. The data available in the case histories of 673 patients aged 29—76 years, operated on in 1995, 2004, and 2006, were analyzed. The study excluded patients with severe intraoperative complications (acute myocardial infarction, a need for extracorporeal circulation, and surgical bleeding. Early activation was made on an operating table if there were no contraindications. Some sections of the study were performed in the matched patient groups. Results. With early activation, the dosages of fentanyl were reduced by 2.5-3 times as compared with the 1995 data; the use of ketamine and diazepam was stopped. Instead of the latter, the currently available inhalational agents are coming into use: midazolam has been introduced and the rate of propofol use has increased. The higher activation rate required the use of flumazenil, naloxone, and proserin. The goal-oriented study of central hemodynamics with emphasis on early activation has indicated that lower dosages of fentanyl have no negative impact on cardiac pump function or myocardial oxygen balance. When the trachea was extubated on the operating table, there was appropriate central hemodynamic stabilization. It was found that the incidence of postoperative myocardial infarctions did not depend on the rate of activation. The frequency of cardiovascular complications was 38.8±5.9% and 22.9±5.0% in the prolonged artificial ventilation (AV and early activation groups, respectively (p<0.05; that of pulmonary complications was 16.4±4.5% and 5.7±2.8%, respectively (p<0.05. Early activation halved the length of stay at an intensive care unit (p<0.05 and reduced postoperative hospitalization at surgery units by 5 days (p< 0.05. Introduction of early activation caused a decrease in the duration of postoperative AV in the

  7. Free-air ionization chamber, FAC-IR-300, designed for medium energy X-ray dosimetry

    International Nuclear Information System (INIS)

    Mohammadi, S.M.; Tavakoli-Anbaran, H.; Zeinali, H.Z.

    2017-01-01

    The primary standard for X-ray photons is based on parallel-plate free-air ionization chamber (FAC). Therefore, the Atomic Energy Organization of Iran (AEOI) is tried to design and build the free-air ionization chamber, FAC-IR-300, for low and medium energy X-ray dosimetry. The main aim of the present work is to investigate specification of the FAC-IR-300 ionization chamber and design it. FAC-IR-300 dosimeter is composed of two parallel plates, a high voltage (HV) plate and a collector plate, along with a guard electrode that surrounds the collector plate. The guard plate and the collector were separated by an air gap. For obtaining uniformity in the electric field distribution, a group of guard strips was used around the ionization chamber. These characterizations involve determining the exact dimensions of the ionization chamber by using Monte Carlo simulation and introducing correction factors.

  8. Quasi-dimensional modeling of a fast-burn combustion dual-plug spark-ignition engine with complex combustion chamber geometries

    International Nuclear Information System (INIS)

    Altın, İsmail; Bilgin, Atilla

    2015-01-01

    This study builds on a previous parametric investigation using a thermodynamic-based quasi-dimensional (QD) cycle simulation of a spark-ignition (SI) engine with dual-spark plugs. The previous work examined the effects of plug-number and location on some performance parameters considering an engine with a simple cylindrical disc-shaped combustion chamber. In order to provide QD thermodynamic models applicable to complex combustion chamber geometries, a novel approach is considered here: flame-maps, which utilizes a computer aided design (CAD) software (SolidWorks). Flame maps are produced by the CAD software, which comprise all the possible flame radiuses with an increment of one-mm between them, according to the spark plug positions, spark timing, and piston position near the top dead center. The data are tabulated and stored as matrices. Then, these tabulated data are adapted to the previously reported cycle simulation. After testing for simple disc-shaped chamber geometries, the simulation is applied to a real production automobile (Honda-Fit) engine to perform the parametric study. - Highlights: • QD model was applied in dual plug engine with complex realistic combustion chamber. • This method successfully modeled the combustion in the dual-plug Honda-Fit engine. • The same combustion chamber is tested for various spark plug(s) locations. • The centrally located single spark-plug results in the fastest combustion

  9. The efficacy of extracorporeal shock wave lithotripsy on single dense calcified gallstones according to computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Takao (Mie Univ., Tsu (Japan). School of Medicine); Shimono, Kazuko; Moriyama, Shigeru; Masuda, Touru; Ikeda, Tetsuya; Umegae, Satoru; Nagata, Norikazu

    1993-05-01

    The efficacy and complications of extracorporeal shock wave lithotripsy (ESWL) for single gallstones were compared between 15 patients with a CT-lucent stone and 18 patients with a dense calcified stone. In all of five patients with a stone smaller than 10 mm in diameter, complete or sufficient clearance was observed, regardless of calcification. However, in 28 patients with a stone larger than 11 mm in diameter, the rates of complete or sufficient clearance were lower in those with a dense calcified stone (64%) than in those with a computed tomography (CT) lucent stone (93%). There was no difference in the rate of complications between patients with a CT-lucent stone and those with a dense calcified stone. These results thus suggest that extracorporeal shock wave lithotripsy may be safely employed for patients with a single calcified gallstone. (author).

  10. Micro ionization chamber dosimetry in IMRT verification: Clinical implications of dosimetric errors in the PTV

    International Nuclear Information System (INIS)

    Sanchez-Doblado, Francisco; Capote, Roberto; Rosello, Joan V.; Leal, Antonio; Lagares, Juan I.; Arrans, Rafael; Hartmann, Guenther H.

    2005-01-01

    Background and purpose: Absolute dose measurements for Intensity Modulated Radiotherapy (IMRT) beamlets is difficult due to the lack of lateral electron equilibrium. Recently we found that the absolute dosimetry in the penumbra region of the IMRT beamlet, can suffer from significant errors (Capote et al., Med Phys 31 (2004) 2416-2422). This work has the goal to estimate the error made when measuring the Planning Target Volume's (PTV) absolute dose by a micro ion chamber (μIC) in typical IMRT treatment. The dose error comes from the assumption that the dosimetric parameters determining the absolute dose are the same as for the reference conditions. Materials and Methods: Two IMRT treatment plans for common prostate carcinoma case, derived by forward and inverse optimisation, were considered. Detailed geometrical simulation of the μIC and the dose verification set-up was performed. The Monte Carlo (MC) simulation allows us to calculate the delivered dose to water and the dose delivered to the active volume of the ion chamber. However, the measured dose in water is usually derived from chamber readings assuming reference conditions. The MC simulation provides needed correction factors for ion chamber dosimetry in non reference conditions. Results: Dose calculations were carried out for some representative beamlets, a combination of segments and for the delivered IMRT treatments. We observe that the largest dose errors (i.e. the largest correction factors) correspond to the smaller contribution of the corresponding IMRT beamlets to the total dose delivered in the ionization chamber within PTV. Conclusion: The clinical impact of the calculated dose error in PTV measured dose was found to be negligible for studied IMRT treatments

  11. Characterization of ionization chambers in double face for X-ray detection systems

    International Nuclear Information System (INIS)

    Costa, Alessandro M. da; Caldas, Linda V.O.

    2000-01-01

    Two identical parallel-plate ionization chambers with collecting electrodes of different materials (in order to obtain different energy dependences), developed at Instituto de Pesquisas Energeticas e Nucleares, were tested in low energy X-radiation beams, simulating a special ionization chamber, of double face, in a Tandem system. The purpose of this work is to justify a project of a double face detection system utilizing ionization chambers in Tandem. In relation to conventional methods, this kind of system will provide more efficient and precise absorbed dose in air measurements and radiation effective energy determinations. The results obtained in relation to characteristics of short- and long-term stabilities and angular and energy dependence show that the project is feasible and very appropriate. (author)

  12. Improving the accuracy of ionization chamber dosimetry in small megavoltage x-ray fields

    Science.gov (United States)

    McNiven, Andrea L.

    The dosimetry of small x-ray fields is difficult, but important, in many radiation therapy delivery methods. The accuracy of ion chambers for small field applications, however, is limited due to the relatively large size of the chamber with respect to the field size, leading to partial volume effects, lateral electronic disequilibrium and calibration difficulties. The goal of this dissertation was to investigate the use of ionization chambers for the purpose of dosimetry in small megavoltage photon beams with the aim of improving clinical dose measurements in stereotactic radiotherapy and helical tomotherapy. A new method for the direct determination of the sensitive volume of small-volume ion chambers using micro computed tomography (muCT) was investigated using four nominally identical small-volume (0.56 cm3) cylindrical ion chambers. Agreement between their measured relative volume and ionization measurements (within 2%) demonstrated the feasibility of volume determination through muCT. Cavity-gas calibration coefficients were also determined, demonstrating the promise for accurate ion chamber calibration based partially on muCT. The accuracy of relative dose factor measurements in 6MV stereotactic x-ray fields (5 to 40mm diameter) was investigated using a set of prototype plane-parallel ionization chambers (diameters of 2, 4, 10 and 20mm). Chamber and field size specific correction factors ( CSFQ ), that account for perturbation of the secondary electron fluence, were calculated using Monte Carlo simulation methods (BEAM/EGSnrc simulations). These correction factors (e.g. CSFQ = 1.76 (2mm chamber, 5mm field) allow for accurate relative dose factor (RDF) measurement when applied to ionization readings, under conditions of electronic disequilibrium. With respect to the dosimetry of helical tomotherapy, a novel application of the ion chambers was developed to characterize the fan beam size and effective dose rate. Characterization was based on an adaptation of the

  13. Extracorporeal Membrane Oxygenation and Modern Detoxification Techniques in a Puerpera with Viral and Bacterial Pneumonia Caused by Flu A(H1N1 Virus

    Directory of Open Access Journals (Sweden)

    R. A. Kornelyuk

    2017-01-01

    Full Text Available Outbreaks of viral infections have become a global healthcare challenge over the last decade. The 2009—2010 flu A (H1N1 outbreak resulted in global pandemia, associated with high morbidity and mortality reaching 31%. Another flu A (H1N1 outbreak occurred in 2015—2016. There is a strong probability that it may be repeated in the future. This infection is associated with its high incidence among pregnant women. There are some published reports describing the efficacy and safety of veno%venous extracorporeal membrane oxygenation (ECMO in patients with severe acute respiratory distress syndrome that is refractory to standard therapeutic options. The article presents a clinical case of a successful use of extracorporeal membrane oxygenation and intermittent renal replacement therapy in a puerpera with acute respiratory distress syndrome caused by flu A (H1N1-related severe viral and bacterial pneumonia. The positive effects of the combination of veno%venous extracorporeal membrane oxygenation and modern detoxification techniques have been demonstrated. Revealed organizational problemswere related to selection criteria for prescription of extracorporeal gas exchange, as well as to carrying out the procedure in an institution in the deficiency of the experienced staff and corresponding equipment.

  14. Extracorporeal membrane oxygenation as a bridge to lung transplantation: A single-center experience in the present era.

    Science.gov (United States)

    Todd, Emily M; Biswas Roy, Sreeja; Hashimi, A Samad; Serrone, Rosemarie; Panchanathan, Roshan; Kang, Paul; Varsch, Katherine E; Steinbock, Barry E; Huang, Jasmine; Omar, Ashraf; Patel, Vipul; Walia, Rajat; Smith, Michael A; Bremner, Ross M

    2017-11-01

    Extracorporeal membrane oxygenation has been used as a bridge to lung transplantation in patients with rapid pulmonary function deterioration. The reported success of this modality and perioperative and functional outcomes are varied. We retrospectively reviewed all patients who underwent lung transplantation at our institution over 1 year (January 1, 2015, to December 31, 2015). Patients were divided into 2 groups depending on whether they required extracorporeal membrane oxygenation support as a bridge to transplant; preoperative characteristics, lung transplantation outcomes, and survival were compared between groups. Of the 93 patients, 12 (13%) received bridge to transplant, and 81 (87%) did not. Patients receiving bridge to transplant were younger, had higher lung allocation scores, had lower functional status, and were more often on mechanical ventilation at listing. Most patients who received bridge to transplant (n = 10, 83.3%) had pulmonary fibrosis. Mean pretransplant extracorporeal membrane oxygenation support was 103.6 hours in duration (range, 16-395 hours). All patients who received bridge to transplant were decannulated immediately after lung transplantation but were more likely to return to the operating room for secondary chest closure or rethoracotomy. Grade 3 primary graft dysfunction within 72 hours was similar between groups. Lung transplantation success and hospital discharge were 100% in the bridge to transplant group; however, these patients experienced longer hospital stays and higher rates of discharge to acute rehabilitation. The 1-year survival was 100% in the bridge to transplant group and 91% in the non-bridge to transplant group (log-rank, P = .24). The 1-year functional status was excellent in both groups. Extracorporeal membrane oxygenation can be used to safely bridge high-acuity patients with end-stage lung disease to lung transplantation with good 30-day, 90-day, and 1-year survival and excellent 1-year functional status

  15. Challenges with Navigating the Precarious Hemostatic Balance during Extracorporeal Life Support: Implications for Coagulation and Transfusion Management.

    Science.gov (United States)

    Andrews, Jennifer; Winkler, Anne M

    2016-10-01

    For the past four decades, extracorporeal life support (ECLS) has been used to treat critically ill adult and pediatric patients with cardiac and/or respiratory failure, and there are increasingly numbers of centers worldwide performing ECLS for numerous indications. Despite the progress with advancing the technology, hemorrhagic and thrombotic complications are frequently reported and associated with worse outcomes, but the exact cause is often elusive or multifactorial. As a result of the interaction between blood and an artificial circuit, anticoagulation is necessary and there is resultant activation of coagulation, fibrinolysis, as well as, an increased inflammatory response. While unfractionated heparin (UFH) remains the mainstay anticoagulant used during ECLS, there is a paucity of published data to develop a universal anticoagulation guideline and centers are forced to create individualized protocols to guide anticoagulation management while lacking expertise. From an international survey, centers often use a combination of tests, which in turn result in discordant results and confused management. Studies are urgently needed to investigate optimization of current anticoagulation strategies with UFH, as well as, use of alternative anticoagulants and non-thrombogenic biomaterials. Blood transfusion during extracorporeal support typically occurs for several reasons, which includes circuit priming, restoration of oxygen carrying capacity, maintenance of a hemostatic balance, and treatment of hemorrhagic complications. As a result, the majority of patients will have been exposed to at least one blood product during extracorporeal support and transfusion utilization is high. ECLS Centers have adopted transfusion thresholds based upon practice rather than evidence as there have been no prospective studies investigating the efficacy of red cell (RBC) transfusion in patients receiving extracorporeal support. In addition, RBC transfusion has been associated with

  16. The use of extracorporeal membrane oxygenation in blunt thoracic trauma: A study of the Extracorporeal Life Support Organization database.

    Science.gov (United States)

    Jacobs, Jordan V; Hooft, Nicole M; Robinson, Brenton R; Todd, Emily; Bremner, Ross M; Petersen, Scott R; Smith, Michael A

    2015-12-01

    Reports documenting the use of extracorporeal membrane oxygenation (ECMO) after blunt thoracic trauma are scarce. We used a large, multicenter database to examine outcomes when ECMO was used in treating patients with blunt thoracic trauma. We performed a retrospective analysis of ECMO patients in the Extracorporeal Life Support Organization database between 1998 and 2014. The diagnostic code for blunt pulmonary contusion (861.21, DRG International Classification of Diseases-9th Rev.) was used to identify patients treated with ECMO after blunt thoracic trauma. Variations of pre-ECMO respiratory support were also evaluated. The primary outcome was survival to discharge; the secondary outcome was hemorrhagic complication associated with ECMO. Eighty-five patients met inclusion criteria. The mean ± SEM age of the cohort was 28.9 ± 1.1 years; 71 (83.5%) were male. The mean ± SEM pre-ECMO PaO2/FIO2 ratio was 59.7 ± 3.5, and the mean ± SEM pre-ECMO length of ventilation was 94.7 ± 13.2 hours. Pre-ECMO support included inhaled nitric oxide (15 patients, 17.6%), high-frequency oscillation (10, 11.8%), and vasopressor agents (57, 67.1%). The mean ± SEM duration of ECMO was 207.4 ± 23.8 hours, and 63 patients (74.1%) were treated with venovenous ECMO. Thirty-two patients (37.6%) underwent invasive procedures before ECMO, and 12 patients (14.1%) underwent invasive procedures while on ECMO. Hemorrhagic complications occurred in 25 cases (29.4%), including 12 patients (14.1%) with surgical site bleeding and 16 (18.8%) with cannula site bleeding (6 patients had both). The rate of survival to discharge was 74.1%. Multivariate analysis showed that shorter duration of ECMO and the use of venovenous ECMO predicted survival. Outcomes after the use of ECMO in blunt thoracic trauma can be favorable. Some trauma patients are appropriate candidates for this therapy. Further study may discern which subpopulations of trauma patients will benefit most from ECMO. Therapeutic

  17. Proton-therapy and hadron-therapy ionization chambers

    International Nuclear Information System (INIS)

    Boissonnat, Guillaume

    2015-01-01

    In the framework of the ARCHADE project (Advanced Resource Center for Hadron-therapy in Europe), a research project in Carbone ion beam therapy and clinical Proton-therapy, this work investigates the beam monitoring and dosimetry aspects of ion beam therapy. The main goal, here, is to understand the operating mode of air ionization chambers, the detectors used for such applications. This study starts at a very fundamental level as the involved physical and chemical parameters of air were measured in various electric field conditions with dedicated setups and used to produce a simulation tools aiming at reproducing the operating response in high intensity PBS (Pencil Beam Scanning) coming from IBA's (Ion Beam Applications) next generation of proton beam accelerators. In addition, an ionization chamber-based dosimetry equipment was developed, DOSION III, for radiobiology studies conducted at GANIL under the supervision of the CIMAP laboratory. (author)

  18. Ion chamber-electrometer measurement system for radiation protection tests in X-ray equipment for interventional procedures

    International Nuclear Information System (INIS)

    Bottaro, Marcio

    2012-01-01

    A new parallel plate ionization chamber with volume of 500 cc and an electrometer with digital interface for data acquisition, configuring an ion chamber electrometer measurement system, were developed to comply with specific requirements for compulsory radiation protection tests in interventional X-ray equipment. The ion chamber has as main characteristics: low cost, mechanical strength and response variation with beam energy of less than 5% in the 40 kV to 150 kV range. The electrometer has a high gain (5x10 8 V/A) transimpedance amplifier circuit and a data acquisition and control system developed in LabVIEW ® platform, including an integrated power supply for the ion chamber bias with adjustable DC voltage output from O to 1000 V and an air density correction system. Electric field calculations, laboratory measurements in standard beams and computational simulations of radiation interactions in chamber volume with Monte Carlo Method were employed in the elaborated methodology of the ion chamber development, which was tested and validated. It was also developed a simplified methodology for electrometer calibration that assures metrological trustworthiness of the measurement system. Tests for the system performance evaluation as environmental influence response, energy response, angular dependency, linearity and air kerma and air kerma rate dependency were performed according to international standards and requirements. Additionally, for a detailed evaluation of the developed ion chamber, simulations with various scattered radiation spectra were performed. The system was applied in leakage radiation, residual radiation and scattered radiation tests, being compared with other reference systems and validated for laboratorial test routine. (author)

  19. Design of In-vessel neutron monitor using micro fission chambers for ITER

    International Nuclear Information System (INIS)

    Nishitani, Takeo; Kasai, Satoshi

    2001-10-01

    A neutron monitor using micro fission chambers to be installed inside the vacuum vessel has been designed for compact ITER (ITER-FEAT). We investigated the responses of the micro fission chambers to find the suitable position of micro fission chambers by a neutron Monte Carlo calculation using MCNP version 4b code. It was found that the averaged output of the micro fission chambers behind blankets at upper outboard and lower outboard is insensitive to the changes in the plasma position and the neutron source profile. A set of 235 U micro fission chamber and ''blank'' detector which is a fissile material free detector to identify noise issues such as from γ-rays are installed behind blankets. Employing both pulse counting mode and Campbelling mode in the electronics, the ITER requirement of 10 7 dynamic range with 1 ms temporal resolution can be accomplished. The in-situ calibration has been simulated by MCNP calculation, where a point source of 14 MeV neutrons is moving on the plasma axis. It was found that the direct calibration is possible by using a neutron generator with an intensity of 10 11 n/s. The micro fission chamber system can meet the required 10% accuracy for a fusion power monitor. (author)

  20. Assesment of PM2.5 emission from corn stover burning determining in chamber combustion

    Science.gov (United States)

    Hafidawati; Lestari, P.; Sofyan, A.

    2018-04-01

    Chamber measurement were conducted to determine Particulate Matter (PM2.5) emission from open burning of corn straw at Garut District, West Java. The of this study is to estimate the concentration of PM2.5 for two types of corn (corncobs and cornstover) for five varieties (Bisma, P29, NK, Bisma, NW). Corn residues were collected and then burned in the chamber combustion. The chamber was designed to simulate the burning in the field, which was observed in the field experiment that meteorological condition was calm wind. The samples were collected using a minivol air sampler. The assessment results of PM2.5 concentrations (mg/m3) from open burning experiment in the chamber for five varieties of corn cobs (Bisma, P29, NK, Bisi, NW) was 9.187; 2.843; 7.409; 3.781; 1.895 respectively. Concentration for corn stover burn was 2.060; 5.283; 4.048; 5.306 and 5.697 respectively. Fluctuations in the value of concentration among these varieties reflect variations in combustion conditions (combustion efficiency) and other parameters including water content, biomass conditions and the meteorological conditions. The combustion efficiency (MCE) of the combustion chamber simulation of corncobs ia lower than the MCE of corn stover, that the concentration PM2.5 more emitted from the burning of corn stover. The results of this study presented provide useful information for the development of local emission factors for PM2.5 from open burning of corn stover in Indonesia.

  1. Electromagnetic reverberation chambers

    CERN Document Server

    Besnier, Philippe

    2013-01-01

    Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

  2. Creating the Deep Space Environment for Testing the James Webb Space Telescope at NASA Johnson Space Center's Chamber A

    Science.gov (United States)

    Homan, Jonathan L.; Cerimele, Mary P.; Montz, Michael E.; Bachtel, Russell; Speed, John; O'Rear, Patrick

    2013-01-01

    Chamber A is the largest thermal vacuum chamber at the Johnson Space Center and is one of the largest space environment chambers in the world. The chamber is 19.8 m (65 ft.) in diameter and 36.6 m (120 ft.) tall and is equipped with cryogenic liquid nitrogen panels (shrouds) and gaseous helium shrouds to create a simulated space environment. It was originally designed and built in the mid 1960 s to test the Apollo Command and Service Module and several manned tests were conducted on that spacecraft, contributing to the success of the program. The chamber has been used since that time to test spacecraft active thermal control systems, Shuttle DTO, DOD, and ESA hardware in simulated Low Earth Orbit (LEO) conditions. NASA is now moving from LEO towards exploration of locations with environments approaching those of deep space. Therefore, Chamber A has undergone major modifications to enable it to simulate these deeper space environments. Environmental requirements were driven, and modifications were funded by the James Webb Space Telescope program, and this telescope, which will orbit Solar/Earth L2, will be the first test article to benefit from the chamber s new capabilities. To accommodate JWST, the Chamber A high vacuum system has been modernized, additional LN2 shrouds have been installed, the liquid nitrogen system has been modified to minimize dependency on electrical power and increase its reliability, a new helium shroud/refrigeration system has been installed to create a colder more stable and uniform heat sink, and the controls have been updated to increase the level of automation and improve operator interfaces. Testing of these major modifications was conducted in August of 2012 and this initial test was very successful, with all major systems exceeding their performance requirements. This paper will outline the changes in overall environmental requirements, discuss the technical design data that was used in the decisions leading to the extensive

  3. Creating the Deep Space Environment for Testing the James Webb Space Telescope at the Johnson Space Center's Chamber A

    Science.gov (United States)

    Homan, Jonathan L.; Cerimele, Mary P.; Montz, Michael E.

    2012-01-01

    Chamber A is the largest thermal vacuum chamber at the Johnson Space Center and is one of the largest space environment chambers in the world. The chamber is 19.8 m (65 ft) in diameter and 36.6 m (120 ft) tall and is equipped with cryogenic liquid nitrogen panels (shrouds) and gaseous helium shrouds to create a simulated space environment. It was originally designed and built in the mid 1960's to test the Apollo Command and Service Module and several manned tests were conducted on that spacecraft, contributing to the success of the program. The chamber has been used since that time to test spacecraft active thermal control systems, Shuttle DTO, DOD, and ESA hardware in simulated Low Earth Orbit (LEO) conditions. NASA is now moving from LEO towards exploration of locations with environments approaching those of deep space. Therefore, Chamber A has undergone major modifications to enable it to simulate these deeper space environments. Environmental requirements were driven, and the modifications were funded, by the James Webb Space Telescope program, and this telescope which will orbit Solar/Earth L2, will be the first test article to benefit from the chamber s new capabilities. To accommodate JWST, the Chamber A high vacuum system has been modernized, additional LN2 shrouds have been installed, the liquid nitrogen system has been modified to remove dependency on electrical power and increase its reliability, a new helium shroud/refrigeration system has been installed to create a colder more stable and uniform heat sink and, the controls have been updated to increase the level of automation and improve operator interfaces. Testing of these major modifications was conducted in August 2012 and this initial test was very successful, with all major systems exceeding their performance requirements. This paper will outline the changes in the overall environmental requirements, discuss the technical design data that was used in the decisions leading to the extensive

  4. Efficacy of extracorporeal shock wave therapy in the treatment of lateral epicondylitis.

    Science.gov (United States)

    Bayram, Korhan; Yesil, Hilal; Dogan, Erdal

    2014-01-01

    Lateral epicondylitis is one of the widely seen lesions of the arm characterized by pain localized over lateral epicondyle which is the insertion site of the wrist extensors, and extensor muscles of the forearm. It is easy to diagnose lateral epicondylitis but treatment involves some inherent drawbacks. Conservative management includes non-steroidal anti-inflammatory drugs, ultrasound therapy, steroid injections, functional bracing, laser therapy and extracorporeal shock wave therapy, however none of these modalities have been shown to be really effective based on evidence-based data. Our study is aimed to determine the efficacy of extracorporeal shock wave therapy (ESWT) therapy in the treatment of lateral epicondylitis. A total of 12 patients with the diagnosis of lateral epicondylitis were included in the study and 3 sessions of ESWT were applied (1 session per week). Maximum grip strength and pain scores were assessed before and at 1. month after the treatment. Spesific tests for lateral epicondylitis were utilized and Turkish version of the Patient Rated Tennis Elbow Evaluation (PRTEE-T) questionnaire was administered and data obtained were analyzed. Visual analog scale (VAS) scores were significantly lower (plateral epicondyilitis was found to be effective on reducing pain, and improving functional activities and quality of life.

  5. MRI-guided therapeutic ultrasound: Temperature feedback control for extracorporeal and endoluminal applicators

    Science.gov (United States)

    Salomir, Rares

    2005-09-01

    Therapeutic ultrasound is a mini-invasive and promising tool for in situ ablation of non-resectable tumors in uterus, breast, esophagus, kidney, liver, etc. Extracorporeal, endoluminal, and interstitial applicators have been successfully tested to date. Magnetic resonance imaging (MRI) is the only available technique providing non-invasive temperature mapping, together with excellent contrast of soft tissue. Coupling of these two technologies offers the advantage of both: (1) on line spatial guidance to the target region, and (2) thermal dose control during the treatment. This talk will provide an overview of the author's experience with automatic, active feedback control of the temperature evolution in tissues, which has been demonstrated with MRI compatible extracorporeal transducers (focused beam) or endoluminal applicators (plane waves). The feedback loop is based on fast switching capabilities of the driving electronics and real time data transfer out of the MR scanner. Precision of temperature control was typically better than 1°C. This approach is expected to improve the efficacy of the treatment (complete tumor ablation) and the thermal security of the critical regions crossed by the acoustic beam. It also permits one to reach an under-lethal heating regime for local drug delivery using thermosensitive liposomes or gene expression control based on hsp promoters.

  6. Dorsal skinfold chamber models in mice

    Directory of Open Access Journals (Sweden)

    Schreiter, Jeannine

    2017-07-01

    Full Text Available Background/purpose: The use of dorsal skinfold chamber models has substantially improved the understanding of micro-vascularisation in pathophysiology over the last eight decades. It allows pathophysiological studies of vascularisation over a continuous period of time. The dorsal skinfold chamber is an attractive technique for monitoring the vascularisation of autologous or allogenic transplants, wound healing, tumorigenesis and compatibility of biomaterial implants. To further reduce the animals’ discomfort while carrying the dorsal skinfold chamber, we developed a smaller chamber (the Leipzig Dorsal Skinfold Chamber and summarized the commercial available chamber models. In addition we compared our model to the common chamber. Methods: The Leipzig Dorsal Skinfold Chamber was applied to female mice with a mean weight of 22 g. Angiogenesis within the dorsal skinfold chamber was evaluated after injection of fluorescein isothiocyanate dextran with an Axio Scope microscope. The mean vessel density within the dorsal skinfold chamber was assessed over a period of 21 days at five different time points. The gained data were compared to previous results using a bigger and heavier dorsal skinfold model in mice. A PubMed and a patent search were performed and all papers related to “dorsal skinfold chamber” from 1 of January 2006 to 31 of December 2015 were evaluated regarding the dorsal skinfold chamber models and their technical improvements. The main models are described and compared to our titanium Leipzig Dorsal Skinfold Chamber model.Results: The Leipzig Dorsal Skinfold Chamber fulfils all requirements of continuous models known from previous chamber models while reducing irritation to the mice. Five different chamber models have been identified showing substantial regional diversity. The newly elaborated titanium dorsal skinfold chamber may replace the pre-existing titanium chamber model used in Germany so far, as it is smaller and lighter

  7. A combination drift chamber/pad chamber for very high readout rates

    International Nuclear Information System (INIS)

    Spiegel, L.; Cataldi, G.; Elia, V.; Mazur, P.; Murphy, C.T.; Smith, R.P.; Yang, W.; Alexopoulos, T.; Durandet, C.; Erwin, A.; Jennings, J.; Antoniazzi, L.; Introzzi, G.; Lanza, A.; Liguori, G.; Torre, P.; Arenton, M.; Conetti, S.; Cox, B.; Dukes, E.; Golovatyuk, V.; Hanlet, P.; McManus, A.; Nelson, K.; Recagni, M.; Segal, J.; Sun, J.; Ballagh, C.; Bingham, H.; Kaeding, T.; Lys, J.; Misawa, S.; Blankman, A.; Borodin, S.; Kononenko, W.; Newcomer, M.; Selove, W.; Trojak, T.; VanBerg, R.; Zhang, S.N.; Block, M.; Corti, G.; LeCompte, T.; Rosen, J.; Yao, T.; Boden, A.; Cline, D.; Ramachandran, S.; Rhoades, J.; Tokar, S.; Budagov, J.; Tsyganov, E.; Cao, Z.L.; He, M.; Wang, C.; Wei, C.; Zhang, N.; Chen, T.Y.; Yao, N.; Clark, K.; Jenkins, M.; Cooper, M.; Creti, P.; Gorini, E.; Grancagnolo, F.; Panareo, M.; Fortney, L.; Kowald, W.; Haire, M.; Judd, D.; Turnbull, L.; Wagoner, D.; Lau, K.; Mo, G.; Trischuk, J.

    1991-11-01

    Six medium-sized (∼1 x 2 m 2 ) drift chambers with pad and stripe readout have been constructed for and are presently operating in Fermi National Accelerator Laboratory experiment E-771. Each chamber module actually represents a pair of identical planes: two sets of anode wires, two sets of stripes, and two sets of pads. The wire planes are read out separately and represent X measurements in the coordinate system of the experiment. The twin stripe and pad planes are internally paired within the chamber modules; stripe signals represent Y measurements and pad signals combination X and Y measurements. Signals which develop on the stripes and pads are mirror (but inverted) images of what is seen on the wires. In addition to being used in the off-line pattern recognition, pad signals are also used as inputs to an on-line high transverse momentum (pt) trigger processor. While the techniques involved in the design and construction of the chambers are not novel, they may be of interest to experiments contemplating very large area, high rate chambers for future spectrometers

  8. A combination drift chamber/pad chamber for very high readout rates

    Energy Technology Data Exchange (ETDEWEB)

    Spiegel, L.; Cataldi, G.; Elia, V.; Mazur, P.; Murphy, C.T.; Smith, R.P.; Yang, W. (Fermi National Accelerator Lab., Batavia, IL (United States)); Alexopoulos, T.; Durandet, C.; Erwin, A.; Jennings, J. (Wisconsin Univ., Madison, WI (United States)); Antoniazzi, L.; Introzzi, G.; Lanza, A.; Liguori, G.; Torre, P. (Pavia Univ. (Italy) Istituto Nazionale di Fisica Nucleare, Rome (Italy)); Arenton, M.; Conetti, S.

    1991-11-01

    Six medium-sized ({approx}1 {times} 2 m{sup 2}) drift chambers with pad and stripe readout have been constructed for and are presently operating in Fermi National Accelerator Laboratory experiment E-771. Each chamber module actually represents a pair of identical planes: two sets of anode wires, two sets of stripes, and two sets of pads. The wire planes are read out separately and represent X measurements in the coordinate system of the experiment. The twin stripe and pad planes are internally paired within the chamber modules; stripe signals represent Y measurements and pad signals combination X and Y measurements. Signals which develop on the stripes and pads are mirror (but inverted) images of what is seen on the wires. In addition to being used in the off-line pattern recognition, pad signals are also used as inputs to an on-line high transverse momentum (pt) trigger processor. While the techniques involved in the design and construction of the chambers are not novel, they may be of interest to experiments contemplating very large area, high rate chambers for future spectrometers.

  9. Perirenal hematomas induced by extracorporeal shock wave lithotripsy (ESWL). Therapeutic management.

    Science.gov (United States)

    Labanaris, Apostolos P; Kühn, Reinhard; Schott, Günter E; Zugor, Vahudin

    2007-09-17

    Extracorporeal shock wave lithotripsy (ESWL) is nowadays accepted as the treatment of choice for the majority of patients with renal or proximal ureteral calculi. Although, a relatively noninvasive modality with low morbidity, minor or major complications can be noted. A relative severe complication for the patient and confusing for the treating physician is the perirenal hematoma. With review the literature and an example of perirenal hematoma induced by ESWL in a patient treated in our department, we describe its therapeutic management.

  10. Extracorporeal life support for critical enterovirus 71 rhombencephalomyelitis: long-term neurologic follow-up.

    Science.gov (United States)

    Lee, Hsiu-Fen; Chi, Ching-Shiang; Jan, Sheng-Ling; Fu, Yun-Ching; Huang, Fang-Liang; Chen, Po-Yen; Wang, Chung-Chi; Wei, Hao-Ji

    2012-04-01

    Enterovirus 71 rhombencephalomyelitis with cardiopulmonary dysfunction has become an endemic problem in Taiwan since an epidemic outbreak in 1998. Such cases frequently involve significant morbidity and mortality. From October 2000-June 2008, we collected 10 consecutive patients diagnosed with enterovirus 71 rhombencephalomyelitis complicated by left heart failure, with or without pulmonary edema, and surviving more than 3 months after receiving extracorporeal life support. Follow-up neurologic outcomes were analyzed prospectively. The median duration of neurologic follow-up was 7 years and 2 months. Significant morbidities included bulbar dysfunction, respiratory failure, and flaccid quadriparesis. Eight patients exhibited bulbar dysfunction, and feeding tubes could be removed from four patients (median, 15.5 months). Respiratory failure was observed in seven patients. Three patients were gradually withdrawn from their tracheostomy tube (median period, 30 months). Intelligence tests revealed four patients with normal cognitive function, one with borderline cognitive function, and one with mild mental retardation. Four were bedridden survivors. Extracorporeal life support for critical enterovirus 71 rhombencephalomyelitis demonstrated decreased neurologic sequelae during long-term follow-up, allowing for decannulation of feeding and tracheostomy tubes, and resulting in improved cognitive function. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Recycling of extracorporeally irradiated autograft for malignant bone tumors: long-term follow-up.

    Science.gov (United States)

    Kotb, Samir Z; Mostafa, Mohamed F

    2013-11-01

    This study was conducted to evaluate the long-term oncological and functional outcomes. Forty-two patients (29 men and 13 women) with primary malignant bone tumors were included in this study. The procedure consisted of wide en bloc resection, clearing the extraosseous soft tissue and medullary content, extracorporeal irradiation with a single dose of 50 Gy using linear accelerator, and reimplantation using suitable fixation devices. The mean survivor follow-up was 54 months (24-174 months). There were 32 (76.2%) patients continuously disease free, 7 (16.7%) died of disease, and 3 (7.1%) alive with disease. Local recurrence was encountered in 4 (9.5%) patients. Nonunion occurred at 3 (6.4%) osteotomy sites. Deep infection developed in 4 (9.5%) cases. There were 13 patients rated excellent, 17 good, 10 fair, and 2 failures according to the Mankin scoring system. The mean ratings of the Musculoskeletal Tumor Society score and the Toronto Extremity Salvage Score were 77 and 81, respectively. The long-term oncological and functional results are encouraging and suggest that extracorporeal irradiation and reimplantation can be a long-lasting biological reconstructive technique in properly selected patients.

  12. Impact of extracorporeal blood flow rate on blood pressure, pulse rate and cardiac output during haemodialysis

    DEFF Research Database (Denmark)

    Schytz, Philip Andreas; Mace, Maria Lerche; Soja, Anne Merete Boas

    2015-01-01

    BACKGROUND: If blood pressure (BP) falls during haemodialysis (HD) [intradialytic hypotension (IDH)] a common clinical practice is to reduce the extracorporeal blood flow rate (EBFR). Consequently the efficacy of the HD (Kt/V) is reduced. However, only very limited knowledge on the effect...

  13. Semi-active engine mount design using auxiliary magneto-rheological fluid compliance chamber

    Science.gov (United States)

    Mansour, H.; Arzanpour, S.; Golnaraghi, M. F.; Parameswaran, A. M.

    2011-03-01

    Engine mounts are used in the automotive industry to isolate engine and chassis by reducing the noise and vibration imposed from one to the other. This paper describes modelling, simulation and design of a semi-active engine mount that is designed specifically to address the complicated vibration pattern of variable displacement engines (VDE). The ideal isolation for VDE requires the stiffness to be switchable upon cylinder activation/deactivation operating modes. In order to have a modular design, the same hydraulic engine mount components are maintained and a novel auxiliary magneto-rheological (MR) fluid chamber is developed and retrofitted inside the pumping chamber. The new compliance chamber is a controllable pressure regulator, which can effectively alter the dynamic performance of the mount. Switching between different modes happens by turning the electrical current to the MR chamber magnetic coil on and off. A model has been developed for the passive hydraulic mount and then it is extended to include the MR auxiliary chamber as well. A proof-of-concept prototype of the design has been fabricated which validates the mathematical model. The results demonstrate unique capability of the developed semi-active mount to be used for VDE application.

  14. Review of wire chamber aging

    International Nuclear Information System (INIS)

    Va'Vra, J.

    1986-02-01

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs

  15. The Use of Extracorporeal Membrane Oxygenation-Cardiopulmonary Resuscitation in Prolonged Cardiac Arrest in Pediatric Patients: Is it Time to Expand It?

    Science.gov (United States)

    Absi, Mohammed; Kumar, Susheel Tk; Sandhu, Hitesh

    2017-09-01

    Extracorporeal membrane oxygenation was instituted as an aid to in-hospital cardiopulmonary resuscitation (E-CPR) nearly 23 years ago, this led to remarkable improvement in survival considering the mortality rate associated with conventional cardiopulmonary resuscitation (CPR). Given this success, one begins to wonder whether the time has come for expanding the use of E-CPR to outside hospital cardiac arrests especially in the light of development of newer extracorporeal life support devices that are small, mobile, and easy to assemble. This editorial will review recent studies on this subject and address some key guidelines and limitations of this evolving and promising technology.

  16. Modeling and simulating combustion and generation of NOx

    International Nuclear Information System (INIS)

    Lazaroiu, Gheorghe

    2007-01-01

    This paper deals with the modeling and simulation of combustion processes and generation of NO x in a combustion chamber and boiler, with supplementary combustion in a gas turbine installation. The fuel burned in the combustion chamber was rich gas with a chemical composition more complex than natural gas. Pitcoal was used in the regenerative boiler. From the resulting combustion products, 17 compounds were retained, including nitrogen and sulphur compounds. Using the developed model, the simulation resulted in excess air for a temperature imposed at the combustion chamber exhaust. These simulations made it possible to determine the concentrations of combustion compounds with a variation in excess combustion. (author)

  17. Change of Pressing Chamber Conicalness at Briquetting Process in Briquetting Machine Pressing Chamber

    Directory of Open Access Journals (Sweden)

    Peter Križan

    2012-01-01

    Full Text Available In this paper, we will present the impact of the conical shape of a pressing chamber, an important structural parameter. Besides the known impact of the technological parameters of pressing chambers, it is also very important to pay attention to their structural parameters. In the introduction, we present a theoretical analysis of pressing chamber conicalness. An experiment aimed at detecting this impact was performed at our institute, and it showed that increasing the conicalness of a pressing chamber improves the quality of the final briquettes. The conicalness of the pressing chamber has a significanteffect on the final briquette quality and on the construction of briquetting machines. The experimental findings presented here show the importance of this parameter in the briquetting process.

  18. Development and manufacturing of special fission chambers for in-core measurement requirements in nuclear reactors

    International Nuclear Information System (INIS)

    Geslot, B.; Berhouet, F.; Oriol, L.; Breaud, S.; Jammes, C.; Filliatre, P.; Villard, J. F.

    2009-01-01

    The Dosimetry Command control and Instrumentation Laboratory (LDCI) at CEA/Cadarache is specialized in the development, design and manufacturing of miniature fission chambers (from 8 mm down to 1.5 mm in diameter). The LDCI fission chambers workshop specificity is its capacity to manufacture and distribute special fission chambers with fissile deposits other than U 235 (typically Pu 242 , Np 237 , U 238 , Th 232 ). We are also able to define the characteristics of the detector for any in-core measurement requirements: sensor geometry, fissile deposit material and mass, filling gas composition and pressure, operating mode (pulse, current or Campbelling) with associated cable and electronics. The fission chamber design relies on numerical simulation and modeling tools developed by the LDCI. One of our present activities in fission chamber applications is to develop a fast neutron flux instrumentation using Campbelling mode dedicated to measurements in material testing reactors. (authors)

  19. Preacclimatization in hypoxic chambers for high altitude sojourns.

    Science.gov (United States)

    Küpper, Thomas E A H; Schöffl, Volker

    2010-09-01

    Since hypoxic chambers are more and more available, they are used for preacclimatization to prepare for sojourns at high altitude. Since there are different protocols and the data differ, there is no general consensus about the standard how to perform preacclimatization by simulated altitude. The paper reviews the different types of exposure and focuses on the target groups which may benefit from preacclimatization. Since data about intermittent hypoxia for some hours per day to reduce the incidence of acute mountain sickness differ, it is suggested to perform preacclimatization by sleeping some nights at a simulated altitude which follows the altitude profile of the "gold standard" for high altitude acclimatization.

  20. Report from Workshop on VOCs in diving chambers

    International Nuclear Information System (INIS)

    Crosbie, A.; Simpson, M.

    2000-05-01

    This report of the 'Setting the Standards' workshop on the problems of volatile organic compounds (VOCs) in diving in offshore operations, sponsored jointly by the UK Health and Safety Executive Offshore Safety Division and the Stolt Rockwater Joint Venture, gives details of the papers presented covering the chemical contamination of diver's atmosphere, sampling protocols and methods, analytical procedures used for VOCs in hyperbaric chambers, and contamination in buildings. The setting of exposure limits in the UK, the derivation of threshold limiting values (TVLs), the selection of Tenax tubes for atmospheric sampling, organic contaminant monitoring, and NASA's approach to contamination in the space environment are examined, and dealing with contamination problems in a submarine atmosphere, and the simulation of a condensate spillage in a diving bell are discussed. Guidelines for the measurement of VOCs in hyperbaric chambers are given in the appendices

  1. Realistic modeling of chamber transport for heavy-ion fusion

    International Nuclear Information System (INIS)

    Sharp, W.M.; Grote, D.P.; Callahan, D.A.; Tabak, M.; Henestroza, E.; Yu, S.S.; Peterson, P.F.; Welch, D.R.; Rose, D.V.

    2003-01-01

    Transport of intense heavy-ion beams to an inertial-fusion target after final focus is simulated here using a realistic computer model. It is found that passing the beam through a rarefied plasma layer before it enters the fusion chamber can largely neutralize the beam space charge and lead to a usable focal spot for a range of ion species and input conditions

  2. Extracorporeal treatment for theophylline poisoning: systematic review and recommendations from the EXTRIP workgroup.

    Science.gov (United States)

    Ghannoum, Marc; Wiegand, Timothy J; Liu, Kathleen D; Calello, Diane P; Godin, Melanie; Lavergne, Valery; Gosselin, Sophie; Nolin, Thomas D; Hoffman, Robert S

    2015-05-01

    The Extracorporeal Treatments in Poisoning workgroup was created to provide evidence-based recommendations on the use of extracorporeal treatments (ECTRs) in poisoning. Here, the workgroup presents its systematic review and recommendations for theophylline. After a systematic review of the literature, a subgroup reviewed articles, extracted data, summarized findings, and proposed structured voting statements following a pre-determined format. A two-round modified Delphi method was chosen to reach a consensus on voting statements and the RAND/UCLA Appropriateness Method was used to quantify disagreement. Anonymous votes were compiled, returned, and discussed. A second vote determined the final recommendations. 141 articles were included: 6 in vitro studies, 4 animal studies, 101 case reports/case series, 7 descriptive cohorts, 4 observational studies, and 19 pharmacokinetic studies, yielding a low-to-very-low quality of evidence for all recommendations. Data on 143 patients were reviewed, including 10 deaths. The workgroup concluded that theophylline is dialyzable (level of evidence = A) and made the following recommendations: ECTR is recommended in severe theophylline poisoning (1C). Specific recommendations for ECTR include a theophylline concentration [theophylline] > 100 mg/L (555 μmol/L) in acute exposure (1C), the presence of seizures (1D), life-threatening dysrhythmias (1D) or shock (1D), a rising [theophylline] despite optimal therapy (1D), and clinical deterioration despite optimal care (1D). In chronic poisoning, ECTR is suggested if [theophylline] > 60 mg/L (333 μmol/L) (2D) or if the [theophylline] > 50 mg/L (278 μmol/L) and the patient is either less than 6 months of age or older than 60 years of age (2D). ECTR is also suggested if gastrointestinal decontamination cannot be administered (2D). ECTR should be continued until clinical improvement is apparent or the [theophylline] is poisoning is amenable to ECTRs. The workgroup recommended

  3. Extracorporeal treatment for carbamazepine poisoning: Systematic review and recommendations from the EXTRIP workgroup

    Science.gov (United States)

    Ghannoum, Marc; Yates, Christopher; Galvao, Tais F.; Sowinski, Kevin M.; Vo, Thi Hai Vân; Coogan, Andrew; Gosselin, Sophie; Lavergne, Valery; Nolin, Thomas D.; Hoffman, Robert S.

    2014-01-01

    Abstract Context. The Extracorporeal Treatments in Poisoning (EXTRIP) workgroup was created to provide evidence and consensus-based recommendations on the use of extracorporeal treatments (ECTRs) in poisoning. Objectives. To perform a systematic review and provide clinical recommendations for ECTR in carbamazepine poisoning. Methods. After a systematic literature search, the subgroup extracted the data and summarized the findings following a pre-determined format. The entire workgroup voted via a two-round modified Delphi method to reach a consensus on voting statements, using a RAND/UCLA Appropriateness Method to quantify disagreement. Anonymous votes were compiled, returned, and discussed in person. A second vote determined the final recommendations. Results. Seventy-four articles met inclusion criteria. Articles included case reports, case series, descriptive cohorts, pharmacokinetic studies, and in-vitro studies; two poor-quality observational studies were identified, yielding a very low quality of evidence for all recommendations. Data on 173 patients, including 6 fatalities, were reviewed. The workgroup concluded that carbamazepine is moderately dialyzable and made the following recommendations: ECTR is suggested in severe carbamazepine poisoning (2D). ECTR is recommended if multiple seizures occur and are refractory to treatment (1D), or if life-threatening dysrhythmias occur (1D). ECTR is suggested if prolonged coma or respiratory depression requiring mechanical ventilation are present (2D) or if significant toxicity persists, particularly when carbamazepine concentrations rise or remain elevated, despite using multiple-dose activated charcoal (MDAC) and supportive measures (2D). ECTR should be continued until clinical improvement is apparent (1D) or the serum carbamazepine concentration is below 10 mg/L (42 the μ in μmol/L looks weird.) (2D). Intermittent hemodialysis is the preferred ECTR (1D), but both intermittent hemoperfusion (1D) or continuous

  4. Predictability of the individual clinical outcome of extracorporeal shock wave therapy for cellulite.

    Science.gov (United States)

    Schlaudraff, Kai-Uwe; Kiessling, Maren C; Császár, Nikolaus Bm; Schmitz, Christoph

    2014-01-01

    Extracorporeal shock wave therapy has been successfully introduced for the treatment of cellulite in recent years. However, it is still unknown whether the individual clinical outcome of cellulite treatment with extracorporeal shock wave therapy can be predicted by the patient's individual cellulite grade at baseline, individual patient age, body mass index (BMI), weight, and/or height. Fourteen Caucasian females with cellulite were enrolled in a prospective, single-center, randomized, open-label Phase II study. The mean (± standard error of the mean) cellulite grade at baseline was 2.5±0.09 and mean BMI was 22.8±1.17. All patients were treated with radial extracorporeal shock waves using the Swiss DolorClast(®) device (Electro Medical Systems, S.A., Nyon, Switzerland). Patients were treated unilaterally with 2 weekly treatments for 4 weeks on a randomly selected side (left or right), totaling eight treatments on the selected side. Treatment was performed at 3.5-4.0 bar, with 15,000 impulses per session applied at 15 Hz. Impulses were homogeneously distributed over the posterior thigh and buttock area (resulting in 7,500 impulses per area). Treatment success was evaluated after the last treatment and 4 weeks later by clinical examination, photographic documentation, contact thermography, and patient satisfaction questionnaires. The mean cellulite grade improved from 2.5±0.09 at baseline to 1.57±0.18 after the last treatment (ie, mean δ-1 was 0.93 cellulite grades) and 1.68±0.16 at follow-up (ie, mean δ-2 was 0.82 cellulite grades). Compared with baseline, no patient's condition worsened, the treatment was well tolerated, and no unwanted side effects were observed. No statistically significant (ie, Pcellulite grade at baseline, BMI, weight, height, or age. Radial shock wave therapy is a safe and effective treatment option for cellulite. The individual clinical outcome cannot be predicted by the patient's individual cellulite grade at baseline, BMI, weight

  5. Second generation extracorporeal lithotripsy: Whither American radiologic leadership

    International Nuclear Information System (INIS)

    Pfister, R.C.

    1987-01-01

    Extracorporeal shock wave lithotripsy was developed by Dornier Medical Systems, Inc., and West German urologists. In the United States the marketing, training, and operation of these wet-tub units were limited to urologists. New dry-treatment lithotriptors are being developed in various countries, including the United States (Medstone), and will be marketed to radiologists, among others, once approved by the FDA for clinical use; future applications will include gallstones as well as renal calculi. Some of these new lithotripors are radiologically intensive, requiring US or fluroscopic guidance and radiography. Since the stone pulverization process in an image-controlled procedure, the units should be managed by radiologists; this will require supportive leadership from all current radiology department chiefs. This presentation reviews the lithotriptors available

  6. Sleeve reaction chamber system

    Science.gov (United States)

    Northrup, M Allen [Berkeley, CA; Beeman, Barton V [San Mateo, CA; Benett, William J [Livermore, CA; Hadley, Dean R [Manteca, CA; Landre, Phoebe [Livermore, CA; Lehew, Stacy L [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA

    2009-08-25

    A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

  7. Dual-chamber inflatable oil boom

    International Nuclear Information System (INIS)

    Blair, R.M.; Tedeschi, E.T.

    1993-01-01

    An elongated floating material containment boom section is described having a normally vertical ballasted skirt depending from flotation means, and convertible from a flattened collapsed condition to a deployable condition wherein buoyancy chamber means extending along the upper edge of said skirt are inflated to expanded buoyant configuration, including: a gas-impervious sleeve extending along the upper edge of said normally vertical skirt forming a first outer collapsible and inflatable flotation chamber, a first inflation valve connecting the interior of said sleeve with the ambient atmosphere, through which gas under pressure may be introduced into said sleeve to inflate said first buoyant outer flotation chamber, elongated gas-impervious tube means positioned inside said outer flotation chamber and forming second collapsible and inflatable internal flotation bladder chamber means, second inflation valve means connecting the interior of said bladder means through said outer flotation chamber to the ambient atmosphere through which gas under pressure may be introduced into said bladder means to inflate it forming said second flotation chamber means inside said outer flotation chamber

  8. BEBC bubble chamber

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

  9. Climatic chamber ergometer

    CSIR Research Space (South Africa)

    Atkins, AR

    1968-01-01

    Full Text Available The design and calibration of an ergometer for exercising subjects during calorimetric studies in the climate chamber, are described. The ergometer is built into the climatic chamber and forms an integral part of the whole instrumentation system foe...

  10. Oxygenation and hemodynamics in left and right cerebral hemispheres during induction of veno-arterial extracorporeal membrane oxygenation.

    NARCIS (Netherlands)

    Heyst, A.F.J. van; Liem, D.; Hopman, J.C.W.; Staak, F.H.J.M. van der; Sengers, R.C.A.

    2004-01-01

    OBJECTIVE: Oxygenation and hemodynamics in the left and right cerebral hemispheres were measured during induction of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). STUDY DESIGN: Using near infrared spectrophotometry, effects of right common carotid artery (RCCA) and right internal

  11. Electrodynamic modeling applied to micro-strip gas chambers

    International Nuclear Information System (INIS)

    Fang, R.

    1998-01-01

    Gas gain variations as functions of time, counting rate and substrate resistivity have been observed with Micro-Strip Gas Chambers (MSGC). Such a chamber is here treated as a system of 2 dielectrics, gas and substrate, with finite resistivities. Electric charging between their interface results in variations of the electric field and the gas gain. The electrodynamic equations (including time dependence) for such a system are proposed. A Rule of Charge Accumulation (RCA) is then derived which allows to determine the quantity and sign of charges accumulated on the surface at equilibrium. In order to apply the equations and the rule to MSGCs, a model of gas conductance induced by ionizing radiation is proposed, and a differential equation and some formulae are derived to calculate the rms dispersion and the spatial distribution of electrons (ions) in inhomogeneous electric fields. RCA coupled with a precise simulation of the electric fields gives the first quantitative explanation of gas gain variations of MSGCs. Finally an electrodynamic simulation program is made to reproduce the dynamic process of gain variation due to surface charging with an uncertainty of at most 15% relative to experimental data. As a consequence, the methods for stabilizing operation of MSGCs are proposed. (author)

  12. Efficiency determination of resistive plate chambers for fast quasi-monoenergetic neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Roeder, M.; Cowan, T.E.; Kempe, M.; Yakorev, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universitaet Dresden, Dresden (Germany); Elekes, Z. [MTA ATOMKI, Debrecen (Hungary); Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Aumann, T.; Caesar, C. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Technische Universitaet Darmstadt, Darmstadt (Germany); Bemmerer, D.; Sobiella, M.; Stach, D.; Wagner, A. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Boretzky, K.; Hehner, J.; Heil, M. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Maroussov, V. [Universitaet zu Koeln, Koeln (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Nusair, O. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Al-Balqa Applied University, Salt (Jordan); Prokofiev, A.V. [Uppsala University, The Svedberg Laboratory, Uppsala (Sweden); Reifarth, R. [Johann Wolfgang Goethe - Universitaet, Frankfurt am Main (Germany); Zilges, A. [Universitaet zu Koeln, Koeln (Germany); Zuber, K. [Technische Universitaet Dresden, Dresden (Germany); Collaboration: R3B Collaboration

    2014-07-15

    Composite detectors made of stainless-steel converters and multigap resistive plate chambers have been irradiated with quasi-monoenergetic neutrons with a peak energy of 175 MeV. The neutron detection efficiency has been determined using two different methods. The data are in agreement with the output of Monte Carlo simulations. The simulations are then extended to study the response of a hypothetical array made of these detectors to energetic neutrons from a radioactive ion beam experiment. (orig.)

  13. Vacuum Chambers for LEP sections

    CERN Multimedia

    1983-01-01

    The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

  14. Characteristics Air Flow in Room Chamber Test Refrigerator Household Energy Consumption with Inlet Flow Variation

    Science.gov (United States)

    Susanto, Edy; Idrus Alhamid, M.; Nasruddin; Budihardjo

    2018-03-01

    Room Chamber is the most important in making a good Testing Laboratory. In this study, the 2-D modeling conducted to assess the effect placed the inlet on designing a test chamber room energy consumption of household refrigerators. Where the geometry room chamber is rectangular and approaching the enclosure conditions. Inlet varied over the side parallel to the outlet and compared to the inlet where the bottom is made. The purpose of this study was to determine and define the characteristics of the airflow in the room chamber using CFD simulation. CFD method is used to obtain flow characteristics in detail, in the form of vector flow velocity and temperature distribution inside the chamber room. The result found that the position of the inlet parallel to the outlet causes air flow cannot move freely to the side of the floor, even flow of air moves up toward the outlet. While by making the inlet is below, the air can move freely from the bottom up to the side of the chamber room wall as well as to help uniform flow.

  15. Creating the Deep Space Environment for Testing the James Webb Space Telescope (JWST) at NASA Johnson Space Center's Chamber A

    Science.gov (United States)

    Homan, Jonathan L.; Cerimele, Mary P.; Montz, Michael E.; Bachtel, Russell; Speed, John; O'Rear, Patrick

    2013-01-01

    Chamber A is the largest thermal vacuum chamber at the Johnson Space Center and is one of the largest space environment chambers in the world. The chamber is 19.8 m (65 ft) in diameter and 36.6 m (120 ft) tall and is equipped with cryogenic liquid nitrogen panels (shrouds) and gaseous helium shrouds to create a simulated space environment. It was originally designed and built in the mid 1960 s to test the Apollo Command and Service Module and several manned tests were conducted on that spacecraft, contributing to the success of the program. The chamber has been used since that time to test spacecraft active thermal control systems, Shuttle DTO, DOD, and ESA hardware in simulated Low Earth Orbit (LEO) conditions. NASA is now moving from LEO towards exploration of locations with environments approaching those of deep space. Therefore, Chamber A has undergone major modifications to enable it to simulate these deeper space environments. Environmental requirements were driven, and modifications were funded by the James Webb Space Telescope program, and this telescope which will orbit Solar/Earth L2, will be the first test article to benefit from the chamber s new capabilities. To accommodate JWST, the Chamber A high vacuum system has been modernized, additional LN2 shrouds have been installed, the liquid nitrogen system has been modified to remove dependency on electrical power and increase its reliability, a new helium shroud/refrigeration system has been installed to create a colder more stable and uniform heat sink, and the controls have been updated to increase the level of automation and improve operator interfaces. Testing of these major modifications was conducted in August of 2012 and this initial test was very successful, with all major systems exceeding their performance requirements. This paper will outline the changes in overall environmental requirements, discuss the technical design data that was used in the decisions leading to the extensive modifications

  16. Reference ionization chamber

    International Nuclear Information System (INIS)

    Golnik, N.; Zielczynski, M.

    1999-01-01

    The paper presents the design of ionization chamber devoted for the determination of the absolute value of the absorbed dose in tissue-equivalent material. The special attention was paid to ensure that the volume of the active gas cavity was constant and well known. A specific property of the chamber design is that the voltage insulators are 'invisible' from any point of the active volume. Such configuration ensures a very good time stability of the electrical field and defines the active volume. The active volume of the chamber was determined with accuracy of 0.3%. This resulted in accuracy of 0.8% in determination of the absorbed dose in the layer of material adherent to the gas cavity. The chamber was applied for calibration purposes at radiotherapy facility in Joint Institute for Nuclear Research in Dubna (Russia) and in the calibration laboratory of the Institute of Atomic Energy in Swierk. (author)

  17. Technical Note: Influence of Compton currents on profile measurements in small-volume ion chambers

    Energy Technology Data Exchange (ETDEWEB)

    Tanny, Sean; Sperling, Nicholas; Parsai, E. Ishmael, E-mail: e.parsai@utoledo.edu [Department of Radiation Oncology, University of Toledo Medical Center, 1325 Conference Drive, Toledo, Ohio 43614 (United States); Holmes, Shannon [Standard Imaging, 3120 Deming Way, Middleton, Wisconsin 53562 (United States)

    2015-10-15

    Purpose: This work is to evaluate the effects of Compton current generation in three small-volume ionization chambers on measured beam characteristics for electron fields. Methods: Beam scans were performed using Exradin A16, A26, and PTW 31014 microchambers. Scans with varying chamber components shielded were performed. Static point measurements, output factors, and cable only irradiations were performed to determine the contribution of Compton currents to various components of the chamber. Monte Carlo simulations were performed to evaluate why one microchamber showed a significant reduction in Compton current generation. Results: Beam profiles demonstrated significant distortion for two of the three chambers when scanned parallel to the chamber axis, produced by electron deposition within the wire. Measurements of ionization produced within the cable identified Compton current generation as the cause of these distortions. The size of the central collecting wire was found to have the greatest influence on the magnitude of Compton current generation. Conclusions: Microchambers can demonstrate significant (>5%) deviations from properties as measured with larger volume chambers (0.125 cm{sup 3} and above). These deviations can be substantially reduced by averaging measurements conducted at opposite polarities.

  18. CT evaluation of the kidneys following extracorporeal shock wave lithotripsy

    International Nuclear Information System (INIS)

    Rubin, J.I.; Arger, P.H.; Pollack, H.M.; Banner, M.P.; Coleman, B.G.; Mintz, M.C.; Van Arsdalen, K.N.

    1986-01-01

    CT scans of the kidneys were obtained iln 50 patients before and after extracorporeal shock wave lithotripsy (ESWL). Post-ESWL scans demonstrated subcapsular hematomas in eight (15%) and intrarenal hematomas in two (4%) patients. Water-density subcapsular collections were seen in three (6%) patients. Treated kidneys showed a mean increase in renal size of 9%. Perinephric stranding and fascial thickening were seen in 37 (70%) of 53 treated renal fossae. While most patients undergoing ESWL will show some posttreatment abnormality on CT, the procedure appears to be associated with a low incidence of serious renal trauma

  19. CT appearance of renal hemorrhage after extracorporeal shock wave lithotripsy

    Energy Technology Data Exchange (ETDEWEB)

    Kanazawa, Susumu; Araki, Toru; Takamoto, Hitoshi; Hata, Kazuhiro

    1988-07-01

    Computed Tomography (CT) was performed in three patients who were suspicious of renal hemorrhage after extracorporeal shock wave lithotripsy (ESWL). Post-ESWL scans demonstrated subcapsular hematoma in all three cases, and intrarenal hemorrhage in two cases, one of which had fluid collection in the pararenal space and hemorrhage in the posterior pararenal space on CT. Thickening of gerota fascia and bridging septa in the perirenal space was visualized on CT in all of them. CT demonstrated clearly the anatomic distribution and extent of renal hemorrhage, and it is important to comprehend the imaging anatomy of the perirenal area for CT evaluation.

  20. CT appearance of renal hemorrhage after extracorporeal shock wave lithotripsy

    International Nuclear Information System (INIS)

    Kanazawa, Susumu; Araki, Toru; Takamoto, Hitoshi; Hata, Kazuhiro

    1988-01-01

    Computed Tomography (CT) was performed in three patients who were suspicious of renal hemorrhage after extracorporeal shock wave lithotripsy (ESWL). Post-ESWL scans demonstrated subcapsular hematoma in all three cases, and intrarenal hemorrhage in two cases, one of which had fluid collection in the pararenal space and hemorrhage in the posterior pararenal space on CT. Thickening of gerota fascia and bridging septa in the perirenal space was visualized on CT in all of them. CT demonstrated clearly the anatomic distribution and extent of renal hemorrhage, and it is important to comprehend the imaging anatomy of the perirenal area for CT evaluation. (author)

  1. An exploratory study with an adaptive continuous intravenous furosemide regimen in neonates treated with extracorporeal membrane oxygenation

    NARCIS (Netherlands)

    M.M.J. van der Vorst (Maria); J. den Hartigh (Jan); E.D. Wildschut (Enno); D. Tibboel (Dick); J. Burggraaf (Jacobus)

    2007-01-01

    textabstractIntroduction: The objective of the present study was to explore a continuous intravenous furosemide regimen that adapts to urine output in neonates treated with extracorporeal membrane oxygenation (ECMO). Methods: Seven neonates admitted to a paediatric surgical intensive care unit for

  2. A study of the response of ionization chambers to mammography beams

    International Nuclear Information System (INIS)

    Kessler, G.; Burns, D.T.; Buermann, L.; Prez, L.A. de

    2007-03-01

    Some simulated mammography radiation beams have been established at the BIPM using a low-energy x-ray tube with a tungsten anode and molybdenum as a filter. The response of two ionization chambers of different types to these beams is compared with that obtained in mammography beams at the PTB and the NMi which were produced with x-ray tubes with molybdenum anodes and molybdenum filters. The relative differences between the chamber responses to these two different types of beams were less than 7 x 10 -3 which implies the uncertainty for the transfer of a calibration from one type of beam to the other. (authors)

  3. Plastic flashtube chambers

    International Nuclear Information System (INIS)

    Frisken, W.R.

    1977-01-01

    A brief discussion is given of the use and operation of plastic flashtube chambers. Gas leaks, electric pulsing, the glow discharge, and readout methods are considered. Three distinct problems with high rate applications deal with resolving time, dead time, and polarization/neutralization of the chamber

  4. ANSYS有限元法在测长绝热真空腔二维热分析中的应用%Two-dimentional Thermal Analysis of Adiabatic Vacuum Chamber with ANSYS Finite Element Simulation

    Institute of Scientific and Technical Information of China (English)

    杨丽峰; 罗志勇; 徐爱华

    2012-01-01

    According to the difficulties of measuring temperature distribution in the adiabatic vacuum chamber, the method of combing ANSYS finite element simulation with experimental study is proposed. ANSYS finite element modeling, parameter identification, meshing, applying loads, and the solution process are described. Simulation results show that changes in ambient temperature 1℃ , heat insulation vacuum chamber temperature will change 0. 085 ℃, and verify the simulation results of the experiments. Test results show that use of the simulation can be accurate and reliable analysis of insulation vacuum chamber temperature, and improve test efficiency and reduce experimental costs.%针对测长绝热真空腔内温度场测量困难的特点,提出应用ANSYS有限元仿真与实验研究相结合的方法进行二维热分析.详细介绍了真空腔的ANSYS有限元建模、参数确定、网格划分、施加载荷和求解过程.仿真结果表明外界环境温度变化1℃,绝热真空腔内温度将变化0.085℃.对仿真结果进行了实验验证,实验结果证明利用该仿真技术可准确、可靠地分析绝热真空腔内的温度场,并且提高实验效率的同时降低了实验成本.

  5. Measurements of Pressure of Extracorporeal Shock Wave Lithotripter Using Pressure-Sensitive Papers

    Science.gov (United States)

    Inose, Naoto; Ide, Masao

    1993-05-01

    This paper describes measurements of pressures at the focal region of the extracorporeal shock wave lithotripter (ESWL) using pressure-sensitive papers. At the focal region of ESWL, ordinary hydrophones are quickly damaged, because of very high pressures. Recently, measurements of pressure at the focal region of ESWL using pressure-sensitive paper have been advised. Therefore, we have studied the effectiveness of pressure-sensitive papers in the measurement of high acoustic pressures at the focal region of ESWL.

  6. Development and manufacturing of special fission chambers for in-core measurement requirements in nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Geslot, B.; Berhouet, F.; Oriol, L.; Breaud, S.; Jammes, C.; Filliatre, P.; Villard, J. F. [CEA, DEN, Dosimetry Command Control and Instrumentation Laboratory, F-13109 Saint-Paul-lez-Durance (France)

    2009-07-01

    The Dosimetry Command control and Instrumentation Laboratory (LDCI) at CEA/Cadarache is specialized in the development, design and manufacturing of miniature fission chambers (from 8 mm down to 1.5 mm in diameter). The LDCI fission chambers workshop specificity is its capacity to manufacture and distribute special fission chambers with fissile deposits other than U{sup 235} (typically Pu{sup 242}, Np{sup 237}, U{sup 238}, Th{sup 232}). We are also able to define the characteristics of the detector for any in-core measurement requirements: sensor geometry, fissile deposit material and mass, filling gas composition and pressure, operating mode (pulse, current or Campbelling) with associated cable and electronics. The fission chamber design relies on numerical simulation and modeling tools developed by the LDCI. One of our present activities in fission chamber applications is to develop a fast neutron flux instrumentation using Campbelling mode dedicated to measurements in material testing reactors. (authors)

  7. Wire chambers: Trends and alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Regler, Meinhard

    1992-05-15

    The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!.

  8. Extracorporeal circulation for rewarming in drowning and near-drowning pediatric patients.

    Science.gov (United States)

    Coskun, Kasim Oguz; Popov, Aron Frederik; Schmitto, Jan Dieter; Hinz, José; Kriebel, Thomas; Schoendube, Friedrich Albert; Ruschewski, Wolfgang; Tirilomis, Theodor

    2010-11-01

    Drowning and near-drowning is often associated with severe hypothermia requiring active core rewarming.We performed rewarming by cardiopulmonary bypass(CPB). Between 1987 and 2007, 13 children (9 boys and 4 girls) with accidental hypothermia were rewarmed by extracorporeal circulation (ECC) in our institution. The average age of the patients was 3.2 years. Resuscitation was started immediately upon the arrival of the rescue team and was continuously performed during the transportation.All patients were intubated and ventilated. Core temperature at admission ranged from 20 to 29°C (mean 25.3°C). Connection to the CPB was performed by thoracic (9 patients) or femoral/iliac means (4 patients). Restoration of circulation was achieved in 11 patients (84.6%). After CPB termination two patients needed an extracorporeal membrane oxygenation system due to severe pulmonary edema.Five patients were discharged from hospital after prolonged hospital stay. During follow-up, two patients died(10 and 15 months, respectively) of pulmonary complications and one patient was lost to follow-up. The two remaining survivors were without neurological deficit.Modes of rewarming, age, sex, rectal temperature, and serum electrolytes did not influence mortality. In conclusion,drowning and near-drowning with severe hypothermia remains a challenging emergency. Rewarming by ECC provides efficient rewarming and full circulatory support.Although nearly half of the children may survive after rewarming by ECC, long-term outcome is limited by pulmonary and neurological complications.

  9. Performance and simulation of a double-gap resistive plate chamber in the avalanche mode

    CERN Document Server

    Ahn Sung Hwan; Hong Byung Sik; Hong Seong Jong; Ito, M; Kang, T I; Kim, B I; Kim, J H; Kim, Y J; Kim, Y U; Koo, D G; Lee Hyup Woo; Lee, K B; Lee Kyong Sei; Lee Seok Jae; Lim, J K; Moon, D H; Nam, S K; Park, S; Park, W J; Rhee June Tak; Ryu, M S; Sim Kwang Souk

    2004-01-01

    We present a detailed analysis of the time and the charge signals of a prototype double-gap resistive plate chamber for the endcap region of the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC). The chamber was built with relatively low-resistivity bakelite. The time and the charge results demonstrate that the high- voltage plateau, which satisfies various CMS requirements for the efficiency, the noise cluster rate, the fraction of the large signal, and the streamer probability, can be extended at least up to 400 V with the present design. In addition, a simple avalanche multiplication model is studied in detail. The model can reproduce the experimental charge spectra reasonably well. The charge information enables us to estimate the effective Townsend coefficient in avalanche-mode operation.

  10. Prototype multiwire proportional chamber

    CERN Multimedia

    1975-01-01

    Chambers of this type were initially developed within the Alpha project (finally not approved). They were designed such to minimize the radiation length with a view to a mass spectrometer of high resolution meant to replace the Omega detector. The chambers were clearly forerunners for the (drift) chambers later built for R606 with the novel technique of crimping the wires. See also photo 7510039X.

  11. LHCb: Performance of the fourgap LHCb Muon Chambers tested with cosmic rays

    CERN Document Server

    Pinci, D

    2007-01-01

    The LHCb Muon System is composed of five detection stations (M1M5)mainly equipped with a total of 1368 MultiWire Proportional Chambers (MWPC). MWPCs need to ensure a high detection efficiency, a fast response and a good space resolution. We present here the results of detailed studies of the performance of different fourgap chambers, completely equipped with the final FrontEnd Electronics, measured with cosmic rays. Aspects such as time resolution, hit multiplicity and time and space structure of the crosstalk hits were measured. For the first time, both types of chambers, those with anodewirereadout and those with cathodepadreadout, were tested and the results are compared. Results hereby obtained will be used to individuate the optimal working conditions of the apparatus and to achieve a more realistic detector description in the LHCb Monte Carlo simulation.

  12. Miniature ionization chamber

    International Nuclear Information System (INIS)

    Alexeev, V.I.; Emelyanov, I.Y.; Ivanov, V.M.; Konstantinov, L.V.; Lysikov, B.V.; Postnikov, V.V.; Rybakov, J.V.

    1976-01-01

    A miniature ionization chamber having a gas-filled housing which accommodates a guard electrode made in the form of a hollow perforated cylinder is described. The cylinder is electrically associated with the intermediate coaxial conductor of a triaxial cable used as the lead-in of the ionization chamber. The gas-filled housing of the ionization chamber also accommodates a collecting electrode shaped as a rod electrically connected to the center conductor of the cable and to tubular members. The rod is disposed internally of the guard electrode and is electrically connected, by means of jumpers passing through the holes in the guard electrode, to the tubular members. The tubular members embrace the guard electrode and are spaced a certain distance apart along its entire length. Arranged intermediate of these tubular members are spacers secured to the guard electrode and fixing the collecting electrode throughout its length with respect to the housing of the ionization chamber

  13. High-intensity positive beams extracted from a compact double-chamber ion source

    International Nuclear Information System (INIS)

    Huck, H.; Somacal, H.; Di Gregorio, D.E.; Fernandez Niello, J.O.; Igarzabal, M.; Di Paolo, H.; Reinoso, M.

    2005-01-01

    This work presents the design and development of a simple ion source, the associated ion extraction optics, and the beam transport of a low-energy and high-current proton accelerator. In its actual version, the ion source can deliver positive proton currents up to 100 mA. This rather high beam current is achieved by adding a small ionization chamber between the discharge chamber containing the filament and the extraction electrode of the ion source. Different parameters of the ion source and the injection beam line are evaluated by means of computer simulations to optimize the beam production and transmission

  14. Central Hemodynamics and Oxygen Transport in Various Activation of Patients Operated On Under Extracorporeal Circulation

    Directory of Open Access Journals (Sweden)

    Ye. V. Dzybinskaya

    2009-01-01

    Full Text Available Objective: to study central hemodynamics, the determinants of myocardial oxygen balance, and the parameters of oxygen transport in various activation of patients after surgery under extracorporeal circulation. Subjects and methods. Thirty-four patients aged 57.8±2.5 years who had coronary heart disease were divided into 2 groups: 1 those with late activation (artificial ventilation time 157±9 min and 2 those with immediate activation (artificial ventilation time 33±6 min. Group 2 patients were, if required, given fentanyl, midazolam, or myorelaxants. Results. During activation, there were no intergroup differences in the mean levels of the major parameters of cardiac pump function, in the determinants of coronary blood flow (coronary perfusion gradients and myocardial oxygen demand (the product of heart rate by systolic blood pressure, and in the parameters of oxygen transport, including arterial lactatemia. After tracheal extubation, the left ventricular pump coefficient was increased considerably (up to 3.8±0.2 and 4.4±0.2 gm/mm Hg/m2 in Groups 1 and 2, respectively; p<0.05 with minimum inotropic support (dopamine and/or dobutamine being used at 2.7±0.3 and 2.4±0.3 mg/kg/min, respectively. In both groups, there were no close correlations between the indices of oxygen delivery and consumption at all stages of the study, which was indicative of no transport-dependent oxygen uptake. Conclusion. When the early activation protocol was followed up, the maximum acceleration of early activation, including that using specific antagonists of anesthetics, has no negative impact on central hemodynamics, the determinants of myocardial oxygen balance and transport in patients operated on under extracorporeal circulation. Key words: early activation, surgery under extracorporeal circulation, tracheal extubation in the operating-room, central hemodynamics, oxygen transport.

  15. Analytic solution of the potential and electric field of a jet type drift chamber

    Energy Technology Data Exchange (ETDEWEB)

    Weltin, A

    1988-02-15

    Starting from the known two-dimensional potential of a multiwire proportional chamber, the analytic expressions of the potential and the electric field are derived for a jet type drift chamber with a central wire plane of alternating sense and potential wires. The design goal of any jet chamber, namely the periodicity of the electric drift field, is imposed as a boundary condition at the beginning. In this way, the formulae are short and can be easily evaluated. In particular, expressions are given for the mean potential of the central wire plane, the drift field and the wire surface fields. Moreover, wire cathodes frequently used in jet chambers are described by analytic expressions. For a given drift field the difference of the potential as compared to a continuous metal cathode is presented. These results allowed to construct a two-dimensional computer simulation of the full OPAL jet chamber with no explicit periodicity but all its boundaries. Using field shaping electrodes a geometrically short yet quite satisfactory termination of a sense wire plane is demonstrated. Finally an example is presented, which is calculated in detail.

  16. Patient guided Piezo-electric Extracorporeal Shockwave Therapy as treatment for chronic severe patellar tendinopathy : A pilot study

    NARCIS (Netherlands)

    Zwerver, J.; Dekker, F.; Pepping, G.J.

    2010-01-01

    Background and purpose: Patellar tendinopathy is a common overuse injury for which no evidence-based treatment guidelines exist. Extracorporeal Shock Wave Therapy (ESWT) seems to be an effective treatment for patellar tendinopathy but the most beneficial treatment strategies still need to be

  17. [Taylor and Hill, Incorporated's JSC Cryo Chamber A

    Science.gov (United States)

    Morales, Rito

    2008-01-01

    NASA commissioned construction of an environmental simulation test chamber which was completed in 1964 at Johnson Space Center (JSC) in Houston, Texas. The facility, Chamber A, was invaluable for testing spacecraft and satellites before deployment to space. By testing spacecraft in an environment similar to the one they would be functioning in, potential problems could be addressed before launch. A new addition to NASA's observatory inventory is called the James Webb Space Telescope (JWST), after a former Administrator of NASA. The new telescope will have 7 times the mirror area of the Hubble, with a target destination approximately one million miles from earth. Scheduled for launch in 2013, the JWST will allow scientists the ability to see, for the first time, the first galaxies that formed in the early Universe. Pre-launch testing of JWST must be performed in environments that approximate its final target space environment as closely as possible.

  18. Wire chambers: Trends and alternatives

    International Nuclear Information System (INIS)

    Regler, Meinhard

    1992-01-01

    The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!

  19. Quantification of extracorporal platelet deposition in cardiopulmonary bypass: Effects of ZK 36374, a prostacyclin analogue

    Energy Technology Data Exchange (ETDEWEB)

    Martin, W.; Spyt, T.; Wheatley, D.J.; Thomas, I.; Davidson, J.F.

    1989-03-01

    The degree of extracorporal platelet sequestration in 32 patients undergoing cardiopulmonary bypass has been assessed using /sup 111/In labelled platelets and both a shadow shield whole body monitor and a standard gamma camera. The effects of ZK 36374, a prostacyclin analogue, on deposition of platelets in the oxygenator and atrial line filter were also investigated. Total platelet deposition in the placebo group ranged from 2.2% to 31.7%, mean 13.9+-7.8%; n=15, and was significantly higher than the deposition in the treatment group, range 0.7% to 9.4%, mean 3.9+-2.6%; n=16, P < 0.001. There was also a highly significant correlation between the gamma camera and whole body monitor measurements, r=0.99, P < 0.001, with no systematic difference between the techniques. This study demonstrates that accurate quantitative assessment of platelet deposition can be achieved with either the gamma camera or whole body monitor. In addition, significant reduction in platelet sequestration in the extracorporal circuit can be achieved by using ZK 36374 during the bypass operation.

  20. [Clinical research of minimal extracorporeal circulation in perioperative blood conservation of coronary artery bypass graft].

    Science.gov (United States)

    Liu, Yan; Cui, Hu-jun; Tao, Liang; Chen, Xu-fa

    2011-04-01

    To analyze the clinical effect of minimal extracorporeal circulation (MECC) in blood conservation perioperatively coronary artery bypass graft (CABG). The data of 120 cases received simple CABG since August 2006 to October 2009 was analyzed retrospectively. All the patients were divided to three groups according to the mode of circulation support in-operation: MECC, conventional extracorporeal circulation (cECC) or off-pump, 40 cases in each group. Jostra MECC system with normal temperature was used in MECC group, and common membrane oxygenator with moderate hypo-temperature was used in cECC group. Collect the data of coagulation and the blood cytological examination perioperatively, the draining volume during the first 24 h after operation, and consumption of blood products perioperatively. Standard and logistic EuroSCORE were higher in MECC group than the others (P blood products in cECC group, but no difference among the three groups. MECC could reduce the ruin to blood cell and interfere to coagulation function during the conventional ECC procedure, decrease the postoperative draining volume and requirement of blood products.

  1. Chamber transport of ''foot'' pulses for heavy-ion fusion

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, W.M.; Callahan-Miller, D.A.; Tabak, M.; Yu, S.S.; Peterson, P.F.

    2002-02-20

    Indirect-drive targets for heavy-ion fusion must initially be heated by ''foot'' pulses that precede the main heating pulses by tens of nanoseconds. These pulses typically have a lower energy and perveance than the main pulses, and the fusion-chamber environment is different from that seen by later pulses. The preliminary particle-in-cell simulations of foot pulses here examine the sensitivity of the beam focusing to ion-beam perveance, background-gas density, and pre-neutralization by a plasma near the chamber entry port.

  2. Extracorporeal shock-wave lithotripsy as an adjunct to biliary interventional procedures

    International Nuclear Information System (INIS)

    Zeman, R.K.; Garra, B.S.; Matsumoto, A.H.; Teitelbaum, G.P.; Barth, K.H.; Cattau, E.L.; Davros, W.J.; McClennan, B.L.; Picus, D.; Paushter, D.M.

    1989-01-01

    This paper reviews the records of nine patients undergoing extracorporeal shock wave lithotripsy (ESWL) of bile duct stones as an adjunct to other biliary intervention. Lithotripsy was successful in producing fragmentation in seven of nine patients. Keeping the duct mildly distended with contrast medium, distributing the shock waves over the stone(s) by taking advantage of respiratory excursion, and pinning stone fragments with balloon catheters facilitated fragmentation. Six patients underwent duct manipulation (stricture dilation, fragment extraction) within 24 hours of ESWL, suggesting that immediate instrumentation is safe in conjunction with lithotripsy

  3. Variation of Pressure Waveforms in Measurements of Extracorporeal Shock Wave Lithotripter

    Science.gov (United States)

    Inose, Naoto; Ide, Masao

    1993-05-01

    In this paper, we describe measurement of variation in pressure waveforms of the acoustic field of an extra-corporeal shock-wave lithotripter (ESWL). Variations in the measured acoustic fields and pressure waveform of an underwater spark-gap-type ESWL with an exhausted spark plug electrode have been reported by researchers using crystal sensors. If the ESWL spark plugs become exhausted, patients feel pain during kidney, biliary stone disintegration. We studied the relationship between exhaustion of electrodes and the variation of pressure waveforms and shock-wave fields of the ESWL using a newly developed hydrophone.

  4. Radiation exposure to patients during extracorporeal shock wave lithotripsy

    International Nuclear Information System (INIS)

    Van Swearingen, F.L.; McCullough, D.L.; Dyer, R.; Appel, B.

    1987-01-01

    Extracorporeal shock wave lithotripsy is rapidly becoming an accepted treatment of renal calculi. Since fluoroscopy is involved to image the stones it is important to know how much radiation the patient receives during this procedure. Surface radiation exposure to the patient was measured in more than 300 fluoroscopic and radiographic procedures using thermoluminescent dosimeters. Initial results showed an average skin exposure of 10.1 rad per procedure for each x-ray unit, comparing favorably with exposure rates for percutaneous nephrostolithotomy and other routine radiological procedures. Factors influencing exposure levels include stone characteristics (location, size and opacity), physician experience and number of shocks required. Suggestions are given that may result in a 50 per cent reduction of radiation exposure

  5. Simulation of the electron cloud density in BEPC II

    International Nuclear Information System (INIS)

    Liu Yudong; Guo Zhiyuan; Wang Jiuqing

    2004-01-01

    Electron Cloud Instability (ECI) may take place in positron storage ring when the machine is operated with multi-bunch positron beam. According to the actual shape of the vacuum chamber in the BEPC II, a program has been developed. With the code, authors can calculate the electron density in the chamber with different length of antechamber and the different secondary electron yield respectively. By the simulation, the possibility to put clearing electrodes in the chamber to reduce the electron density in the central region of the chamber is investigated. The simulation provides meaningful and important results for the BEPC II project and electron cloud instability research

  6. Directed Energy Anechoic Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

  7. Development of a simulator with thyroid nodules for nuclear medicine

    International Nuclear Information System (INIS)

    Ferreira, F.C.L.; Peixoto, J.A.; Maciel, M.F.; Souza, D.N.; Cunha, C.J.

    2009-01-01

    Nuclear medicine is one of the methods used to diagnose diseases by the use of ionizing radiation. In this method, a radioisotope is injected into the patient and is directed to the body that should be evaluated. After this the patient is examined by a scintigraphic chamber, which will result in an image to view the organs evaluated. To verify the ability to view the chambers are made of quality control tests using simulators with objects that may have characteristics similar to that of human organs and systems. In this work, an object was made of acrylic thyroid simulator used for quality control in scintillation chamber for use in teaching morphological analysis of the thyroid. To simulate the thyroid nodules were included in the simulator of acrylic columns with different diameters. The analysis of thyroid scintigraphy was also used for quality control tests. These tests were conducted in scintigraphic chamber GE Millennium MG. In quality control was verified the spatial resolution of the equipment. The radiopharmaceutical used was 99m Tc. The phantom image was closer to an image with the presence of thyroid nodules. The simulator thyroid tested in this work can now be used for quality control tests in other scintillation chambers, enabling students and professionals in nuclear medicine know more about the objects simulators. (author)

  8. Streamer chamber: pion decay

    CERN Multimedia

    1992-01-01

    The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

  9. PS wire chamber

    CERN Multimedia

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  10. [EFFECTIVENESS OF EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY IN PATIENTS WITH UROLITHIASIS OF A SOLITARY KIDNEY].

    Science.gov (United States)

    Parshenkova, I G; Dutov, V V; Rumjancev, A A; Mamedov, E A

    2015-01-01

    The article presents results of extracorporeal shock wave lithotripsy (ESWL) in 62 patients with urolithiasis of a solitary kidney. In 50 (80.6%) patients calculi were located in the kidney and in 12 (19.4%) patients in the ureter. Effectiveness of ESWL at 3 month follow-up was 85.5%, which is somewhat lower than in patients with two healthy kidneys due to the choice of sparing low-energy modes of lithotripsy. The effectiveness of ESWL depended on the size of the original calculi (ppre-drainage of the kidney before a session of ESWL in patients with large and multiple calculi. There was no correlation between the occurrence of complications during treatment and the clinical form of a solitary kidney (p>0.05). In patients with stones larger than 1 cm and a moderate baseline abnormalities of the upper urinary tract urodynamics ESWL was less effective (pcalculus (p=0.504). Extracorporeal shock wave lithotripsy is a highly effective and safe treatment of stones of a solitary kidney. Rational choice of indications and contraindications for the use of ESWL in a specific clinical situation is of great importance.

  11. Directional muon jet chamber for a muon collider (Groovy Chamber)

    International Nuclear Information System (INIS)

    Atac, M.

    1996-10-01

    A directional jet drift chamber with PAD readout is proposed here which can select vertex originated muons within a given time window and eliminate those muons which primarily originate upstream, using only a PAD readout. Drift time provides the Z-coordinate, and the center of gravity of charge distribution provides the r-ψ coordinates. Directionality at the trigger level is obtained by the timing measurement from the PAD hits within a given time window. Because of the long drift time between the bunch crossings, a muon collider enables one to choose a drift distance in the drift chamber as long as 50 cm. This is an important factor in reducing cost of drift chambers which have to cover relatively large areas

  12. Influences of magma chamber ellipticity on ring fracturing and eruption at collapse calderas

    International Nuclear Information System (INIS)

    Holohan, Eoghan P; Walsh, John J; Vries, Benjamin van Wyk de; Troll, Valentin R; Walter, Thomas R

    2008-01-01

    Plan-view ellipticity of a pre-caldera magma reservoir, and its influence on the development of caldera ring fracturing and eruptive behaviour, have not previously been subjected to dedicated evaluation. We experimentally simulated caldera collapse into elliptical magma chambers and found that collapse into highly-elliptical chambers produced a characteristic pattern of ring-fault localization and lateral propagation. Although results are preliminary, the general deformation pattern for elliptical resurgence shows strong similarities to elliptical collapse. Ring faults accommodating uplift again initiate around the chamberos short axis and are reverse, but dip inward. Field and geophysical observations at several elliptical calderas of varying scale (e.g. Long Valley, Katmai, and Rabaul calderas) are consistent with a control from elliptical magma chamber geometry on ring fracturing and eruption, as predicted from our experiments.

  13. Influences of magma chamber ellipticity on ring fracturing and eruption at collapse calderas

    Energy Technology Data Exchange (ETDEWEB)

    Holohan, Eoghan P; Walsh, John J [Fault Analysis Group, School of Geological Sciences, University College Dublin, Belfield, Dublin 4 (Ireland); Vries, Benjamin van Wyk de [Laboratoire Magmas et Volcans, 5 rue Kessler, 63038 Clermont-Ferrand (France); Troll, Valentin R [Department of Earth Sciences, Uppsala University, SE-752 36, Uppsala (Sweden); Walter, Thomas R [GFZ Potsdam, Telegrafenberg, Potsdam, D-14473 (Germany)], E-mail: Eoghan.Holohan@ucd.ie

    2008-10-01

    Plan-view ellipticity of a pre-caldera magma reservoir, and its influence on the development of caldera ring fracturing and eruptive behaviour, have not previously been subjected to dedicated evaluation. We experimentally simulated caldera collapse into elliptical magma chambers and found that collapse into highly-elliptical chambers produced a characteristic pattern of ring-fault localization and lateral propagation. Although results are preliminary, the general deformation pattern for elliptical resurgence shows strong similarities to elliptical collapse. Ring faults accommodating uplift again initiate around the chamberos short axis and are reverse, but dip inward. Field and geophysical observations at several elliptical calderas of varying scale (e.g. Long Valley, Katmai, and Rabaul calderas) are consistent with a control from elliptical magma chamber geometry on ring fracturing and eruption, as predicted from our experiments.

  14. Pencil-shaped radiation detection ionization chamber

    International Nuclear Information System (INIS)

    Suzuki, A.

    1979-01-01

    A radiation detection ionization chamber is described. It consists of an elongated cylindrical pencil-shaped tubing forming an outer wall of the chamber and a center electrode disposed along the major axis of the tubing. The length of the chamber is substantially greater than the diameter. A cable connecting portion at one end of the chamber is provided for connecting the chamber to a triaxial cable. An end support portion is connected at the other end of the chamber for supporting and tensioning the center electrode. 17 claims

  15. Propagation of a premixed flame in a divided-chamber combustor

    Science.gov (United States)

    Cattolica, R. J.; Barr, P. K.; Mansour, N. N.

    1989-01-01

    Experimental observations on the propagation of lean premixed ethylene-air flames in a divided-chamber combustion vessel have been compared with the results of numerical simulations based on a flame sheet-vortex dynamics model in axisymmetric coordinates. Flame speeds were found to increase from 10-24 cm/s as the equivalence ratio was varied from 0.5-0.65 in the experiments. Using the associated increase in gas velocity with equivalence ratio, the estimated Reynolds number in the experiment was changed from 1870 to 8090. Good agreement between experimental and theoretical results was obtained for the prechamber flame propagation rates and for the spatial and temporal development of the flame in the main combustion chamber at the lowest Reynolds number.

  16. The Xenon Test Chamber Q-SUN® for testing realistic tolerances of fungi exposed to simulated full spectrum solar radiation.

    Science.gov (United States)

    Dias, Luciana P; Araújo, Claudinéia A S; Pupin, Breno; Ferreira, Paulo C; Braga, Gilberto Ú L; Rangel, Drauzio E N

    2018-06-01

    The low survival of insect-pathogenic fungi when used for insect control in agriculture is mainly due to the deleterious effects of ultraviolet radiation and heat from solar irradiation. In this study, conidia of 15 species of entomopathogenic fungi were exposed to simulated full-spectrum solar radiation emitted by a Xenon Test Chamber Q-SUN XE-3-HC 340S (Q-LAB ® Corporation, Westlake, OH, USA), which very closely simulates full-spectrum solar radiation. A dendrogram obtained from cluster analyses, based on lethal time 50 % and 90 % calculated by Probit analyses, separated the fungi into three clusters: cluster 3 contains species with highest tolerance to simulated full-spectrum solar radiation, included Metarhizium acridum, Cladosporium herbarum, and Trichothecium roseum with LT 50  > 200 min irradiation. Cluster 2 contains eight species with moderate UV tolerance: Aschersonia aleyrodis, Isaria fumosorosea, Mariannaea pruinosa, Metarhizium anisopliae, Metarhizium brunneum, Metarhizium robertsii, Simplicillium lanosoniveum, and Torrubiella homopterorum with LT 50 between 120 and 150 min irradiation. The four species in cluster 1 had the lowest UV tolerance: Lecanicillium aphanocladii, Beauveria bassiana, Tolypocladium cylindrosporum, and Tolypocladium inflatum with LT 50  solar radiation before. We conclude that the equipment provided an excellent tool for testing realistic tolerances of fungi to full-spectrum solar radiation of microbial agents for insect biological control in agriculture. Copyright © 2018 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  17. Effects of inlet distortion on gas turbine combustion chamber exit temperature profiles

    Science.gov (United States)

    Maqsood, Omar Shahzada

    Damage to a nozzle guide vane or blade, caused by non-uniform temperature distributions at the combustion chamber exit, is deleterious to turbine performance and can lead to expensive and time consuming overhaul and repair. A test rig was designed and constructed for the Allison 250-C20B combustion chamber to investigate the effects of inlet air distortion on the combustion chamber's exit temperature fields. The rig made use of the engine's diffuser tubes, combustion case, combustion liner, and first stage nozzle guide vane shield. Rig operating conditions simulated engine cruise conditions, matching the quasi-non-dimensional Mach number, equivalence ratio and Sauter mean diameter. The combustion chamber was tested with an even distribution of inlet air and a 4% difference in airflow at either side. An even distribution of inlet air to the combustion chamber did not create a uniform temperature profile and varying the inlet distribution of air exacerbated the profile's non-uniformity. The design of the combustion liner promoted the formation of an oval-shaped toroidal vortex inside the chamber, creating localized hot and cool sections separated by 90° that appeared in the exhaust. Uneven inlet air distributions skewed the oval vortex, increasing the temperature of the hot section nearest the side with the most mass flow rate and decreasing the temperature of the hot section on the opposite side. Keywords: Allison 250, Combustion, Dual-Entry, Exit Temperature Profile, Gas Turbine, Pattern Factor, Reverse Flow.

  18. Numerical modeling and investigation of two-phase reactive flow in a high-low pressure chambers system

    International Nuclear Information System (INIS)

    Cheng, Cheng; Zhang, Xiaobing

    2016-01-01

    Highlights: • A novel two-dimensional two-phase flow model is established for the high-low pressure chambers system. • A strong packing of particles is observed at the projectile base and will cause the pressure to rise faster. • Different length–diameter ratios can affect the flow behavior through the vent-holes obviously. • The muzzle velocity decreases with the length–diameter ratio of the high-pressure chamber. - Abstract: A high-low pressure chambers system is proposed to meet the demands of low launch acceleration for informative equipment in many special fields such as Aeronautics, Astronautics and Weaponry. A two-dimensional two-phase flow numerical model is established to describe the complex physical process based on a modified two-fluid theory, which takes into account gas production, interphase drag, intergranular stress, and heat transfer between two phases. In order to reduce the computational cost, the parameters in the high-pressure chamber at the instant the vent-holes open are calculated by the zero-dimensional model as the initial conditions for the two-phase flow simulation in the high-low pressure chambers system. The simulation results reveal good agreement with the experiments and the launch acceleration of a projectile can be improved by this system. The propellant particles can be tracked clearly in both chambers and a strong packing of particles at the base of projectile will cause the pressure to rise faster than at other areas both in the axis and radial directions. The length–diameter ratio of the high-pressure chamber (a typical multi-dimensional parameter) is investigated. Different length–diameter ratios can affect the maximum pressure drop and the loss of total pressure impulse through the vent-hole, then the muzzle velocity and the launch acceleration of projectiles can be influenced directly. This article puts forward a new prediction tool for the understanding and design of transient processes in high-low pressure

  19. Extracorporeal treatment for barbiturate poisoning: recommendations from the EXTRIP Workgroup.

    Science.gov (United States)

    Mactier, Robert; Laliberté, Martin; Mardini, Joelle; Ghannoum, Marc; Lavergne, Valery; Gosselin, Sophie; Hoffman, Robert S; Nolin, Thomas D

    2014-09-01

    The EXTRIP (Extracorporeal Treatments in Poisoning) Workgroup conducted a systematic review of barbiturate poisoning using a standardized evidence-based process to provide recommendations on the use of extracorporeal treatment (ECTR) in patients with barbiturate poisoning. The authors reviewed all articles, extracted data, summarized key findings, and proposed structured voting statements following a predetermined format. A 2-round modified Delphi method was used to reach a consensus on voting statements, and the RAND/UCLA Appropriateness Method was used to quantify disagreement. 617 articles met the search inclusion criteria. Data for 538 patients were abstracted and evaluated. Only case reports, case series, and nonrandomized observational studies were identified, yielding a low quality of evidence for all recommendations. Using established criteria, the workgroup deemed that long-acting barbiturates are dialyzable and short-acting barbiturates are moderately dialyzable. Four key recommendations were made. (1) The use of ECTR should be restricted to cases of severe long-acting barbiturate poisoning. (2) The indications for ECTR in this setting are the presence of prolonged coma, respiratory depression necessitating mechanical ventilation, shock, persistent toxicity, or increasing or persistently elevated serum barbiturate concentrations despite treatment with multiple-dose activated charcoal. (3) Intermittent hemodialysis is the preferred mode of ECTR, and multiple-dose activated charcoal treatment should be continued during ECTR. (4) Cessation of ECTR is indicated when clinical improvement is apparent. This report provides detailed descriptions of the rationale for all recommendations. In summary, patients with long-acting barbiturate poisoning should be treated with ECTR provided at least one of the specific criteria in the first recommendation is present. Copyright © 2014 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  20. Single-port (OctoPort) assisted extracorporeal ovarian cystectomy for the treatment of large ovarian cysts: compare to conventional laparoscopy and laparotomy.

    Science.gov (United States)

    Chong, Gun Oh; Hong, Dae Gy; Lee, Yoon Soon

    2015-01-01

    To evaluate single-port assisted extracorporeal cystectomy for treatment of large ovarian cysts and to compare its surgical outcomes, complications, and cystic content spillage rates with those of conventional laparoscopy and laparotomy. Retrospective study (Canadian Task Force classification II-2). University teaching hospital. Twenty-five patients who underwent single-port assisted extracorporeal cystectomy (group 1), 33 patients who underwent conventional laparoscopy (group 2), and 25 patients who underwent laparotomy (group 3). Surgical outcomes, complications, and spillage rates in group 1 were compared with those in groups 2 and 3. Patients characteristics and tumor histologic findings were similar in the 3 groups. The mean (SD) largest diameter of ovarian cysts was 11.4 (4.2) cm in group 1, 9.7 (2.3) cm in group 2, and 12.0 (3.4) cm in group 3. Operative time in groups 1 and 2 was similar at 69.3 (26.3) minutes vs 73.1 (36.3) minutes (p = .66); however, operative time in group 1 was shorter than in group 3, at 69.3 (26.3) minutes vs 87.5 (26.6) minutes (p =.02). Blood loss in group 1 was significantly lower than in groups 2 and 3, at 16.0 (19.4) mL vs 36.1 (20.7) mL (p < .001) and 16.0 (19.4) mL vs 42.2 (39.7) mL (p = .005). The spillage rate in group 1 was profoundly lower than in group 2, at 8.0% vs 69.7% (p < .001). Single-port assisted extracorporeal cystectomy offers an alternative to conventional laparoscopy and laparotomy for management of large ovarian cysts, with comparable surgical outcomes. Furthermore, cyst content spillage rate in single-port assisted extracorporeal cystectomy was remarkably lower than that in conventional laparoscopy. Copyright © 2015. Published by Elsevier Inc.