WorldWideScience

Sample records for liquid sodium-water reactions

  1. Sodium/water reactions in steam generators of liquid metal fast breeder reactors

    International Nuclear Information System (INIS)

    Hori, M.

    1980-01-01

    The status of the research and development on sodium/water reactions resulting from the leakage of water into sodium in LMFBR steam generators is reviewed. The importance of sodium/water reaction phenomena in the design and operation of steam generators is discussed. The effects of sodium/water reactions are evaluated and methods of protection against these phenomena are surveyed. The products of chemical reactions between sodium and water under steam generator conditions are H 2 , NaOH, Na 2 O and NaH. Together with the temperature rise due to the associated exothermic reaction, these reaction products cause effects such as self-wastage, single- and multi-target wastage, and rapid pressure increase, depending on the size of the leak hole or the magnitude of leak rate. As for the wastage phenomena of small leaks, the effects of various factors have been studied and experimental correlations, as well as some theoretical work, have been performed. To investigate the pressure phenomena of a large leak, large-scale tests have been conducted by various organizations, and the computer codes to analyse these phenomena have been developed and verified by experiments. In the design of steam generators, an initial failure up to a hypothetical double-ended guillotine rupture of a single heat transfer tube is widely used as the design basis leak. Protection systems for LMFBR plants consist of leak detection devices, leak termination devices, and reaction pressure relief devices. From analyses based on research and development activities, as well as from experience with leaks in steam generator test loops and reactor plants, it has been confirmed that protection systems can satisfactorily be designed to accommodate leak incidents in LMFBR plants. (author)

  2. Liquid metal fast breeder reactor steam generator survey of the consequences of large scale sodium water reaction

    International Nuclear Information System (INIS)

    Vambenepe, G.

    1978-01-01

    The ''Retona'' three-dimensional hydrodynamic computing code is being developed by Electricity de France to survey the consequences, on the very plant, of a large scale sodium water reaction in liquid metal steam generators. In this communication, the heat-exchanger geometry is schematized and the problem solving process briefly described under assumed simplifying hypotheses. The application of the results to the Creusot-Loire steam generator selected for Super-Phenix are given as an example. (author)

  3. Theoretical Study of Sodium-Water Surface Reaction Mechanism

    Science.gov (United States)

    Kikuchi, Shin; Kurihara, Akikazu; Ohshima, Hiroyuki; Hashimoto, Kenro

    Computational study of the sodium-water reaction at the gas (water) - liquid (sodium) interface has been carried out using the ab initio (first-principle) method. A possible reaction channel has been identified for the stepwise OH bond dissociations of a single water molecule. The energetics including the binding energy of a water molecule on the sodium surface, the activation energies of the bond cleavages, and the reaction energies, have been evaluated, and the rate constants of the first and second OH bond-breakings have been compared. It was found that the estimated rate constant of the former was much larger than the latter. The results are the basis for constructing the chemical reaction model used in a multi-dimensional sodium-water reaction code, SERAPHIM, being developed by Japan Atomic Energy Agency (JAEA) toward the safety assessment of the steam generator (SG) in a sodium-cooled fast reactor (SFR).

  4. Theoretical study of sodium-water surface reaction mechanism

    International Nuclear Information System (INIS)

    Kikuchi, Shin; Kurihara, Akikazu; Ohshima, Hiroyuki; Hashimoto, Kenro

    2012-01-01

    Computational study of the sodium-water reaction at the gas (water) - liquid (sodium) interface has been carried out using the ab initio (first-principle) method. A possible reaction channel has been identified for the stepwise OH bond dissociations of a single water molecule. The energetics including the binding energy of a water molecule on the sodium surface, the activation energies of the bond cleavages, and the reaction energies, have been evaluated, and the rate constants of the first and second OH bond-breakings have been compared. It was found that the estimated rate constant of the former was much larger than the latter. The results are the basis for constructing the chemical reaction model used in a multi-dimensional sodium-water reaction code, SERAPHIM, being developed by Japan Atomic Energy Agency (JAEA) toward the safety assessment of the steam generator (SG) in a sodium-cooled fast reactor (SFR). (author)

  5. Temperature dependence on sodium-water chemical reaction

    International Nuclear Information System (INIS)

    Tamura, Kenta; Deguchi, Yoshihiro; Suzuki, Koichi; Takata, Takashi; Yamaguchi, Akira; Kikuchi, Shin; Ohshima, Hiroyuki

    2012-01-01

    In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using laser diagnostics. A quasi one-dimensional flame model is also applied to a sodium-water counter-flow reaction field. Temperature, H 2 , H 2 O, OH, Na and Particulate matter were measured using laser induced fluorescence and CARS in the counter-flow reaction field. The temperature of the reaction field was also modified to reduce the condensation of Na in the reaction zone. (author)

  6. Sodium-water reaction test facility (SWAT-3)

    International Nuclear Information System (INIS)

    Shimazu, Hisashi; Ukechi, Kazutoshi; Sasakura, Kazutake; Kusunoki, Junichi

    1976-01-01

    In the development of the liquid metal cooled fast breeder reactor (LMFBR), the steam generator (SG) is considered one of the most important components. The Power Reactor and Nuclear Fuel Development Corporation (PNC) is now promoting the research and development of the SG system used with the prototype fast breeder reactor ''Monju''. In this research, the phenomena of the sodium-water reaction in the SG are the key which must be investigated for the solution of problems. The test facility (SWAT-3) simulating Monju's SG on the scale of 1/2.5 was designed, fabricated and installed by IHI at Oarai Engineering Center of PNC, its pre-operation being accomplished in February 1975. The purpose of SWAT-3 is summarized as follows: (1) To perform an overall test on the safety of Monju's SG and intermediate heat transport system under the design condition against sodium-water reaction accidents. (2) To investigate the damage of the SG structure caused by the sodium-water reaction, and the possibility of repair and recovery operations. The first test was accomplished successfully on June 9, 1975. As a result of the test, the fundamental function of this test facility was proven to be satisfactory as expected. (auth.)

  7. Sodium-water reaction in double pool LMFBR, (5)

    International Nuclear Information System (INIS)

    Yoshida, Kazuo; Kumagai, Hiromichi; Nishi, Yoshihisa; Uotani, Masaki

    1990-01-01

    Experiments were conducted using a 1/5 scale model of the Double Pool in order to evaluate a pressure rise caused by a large scale sodium-water reaction. The experiments were focused on the pressure rise caused by the piston motion of liquid sodium. It appeared from the results that the magnitude of this pressure rise depends on the depth of reaction point, and that a pressure rise more than 1 MPa would arise in the real Double Pool plant. A new design of steam generator is proposed to mitigate the pressure rise. (author)

  8. Sodium-water reaction product flow system

    Energy Technology Data Exchange (ETDEWEB)

    Shirataki, K; Wada, H

    1978-11-18

    Purpose: To provide the subject equipments wherein thermal insulating layers which neither exfoliate nor react by the impact due to high temperature sodium and hydrogen gas and are used for mitigating the thermal impact are provided on the inner surfaces of the emission system equipments, thereby preventing the destruction of the emission system equipments. Constitution: Thermal insulating layers are formed on the inner surfaces of sodium-water reaction product emission system equipments, that is, the inner surface of the emission system pipeline, that of the accommodation vessel and the surface of the cyclone separator, by film treatment, coating or heat resisting coating, and these surfaces are covered with the layers. Each of the layers is made of a material which does not cause a rapid reaction with high temperature sodium or hydrogen gas nor exfoliates and is withstandable for several seconds in which the thermal impact of at least the emission system comes into question, and its thickness is more than one capable of securing the necessary thermal resistance computed by the thermal impact analysis of the emission system.

  9. Sodium-water reaction product flow system

    International Nuclear Information System (INIS)

    Shirataki, Koji; Wada, Hozumi.

    1978-01-01

    Purpose: To provide the subject equipments wherein thermal insulating layers which neither exfoliate nor react by the impact due to high temperature sodium and hydrogen gas and are used for mitigating the thermal impact are provided on the inner surfaces of the emission system equipments, thereby preventing the destruction of the emission system equipments. Constitution: Thermal insulating layers are formed on the inner surfaces of sodium-water reaction product emission system equipments, that is, the inner surface of the emission system pipeline, that of the accommodation vessel and the surface of the cyclone separator, by film treatment, coating or heat resisting coating, and these surfaces are covered with the layers. Each of the layers is made of a material which does not cause a rapid reaction with high temperature sodium or hydrogen gas nor exfoliates and is withstandable for several seconds in which the thermal impact of at least the emission system comes into question, and its thickness is more than one capable of securing the necessary thermal resistance computed by the thermal impact analysis of the emission system. (Yoshihara, H.)

  10. Reaction path analysis of sodium-water reaction phenomena in support of chemical reaction model development

    International Nuclear Information System (INIS)

    Kikuchi, Shin; Ohshima, Hiroyuki; Hashimoto, Kenro

    2011-01-01

    Computational study of the sodium-water reaction at the gas (water) - liquid (sodium) interface has been carried out using ab initio (first-principle) method. A possible reaction channel has been identified for the stepwise OH bond dissociations of a single water molecule. The energetics including the binding energy of a water molecule to the sodium surface, the activation energies of the bond cleavages, and the reaction energies, have been evaluated, and the rate constants of the first and second OH bond-breakings have been compared. The results are used as the basis for constructing the chemical reaction model used in a multi-dimensional sodium-water reaction code, SERAPHIM, being developed by JAEA toward the safety assessment of the steam generator (SG) in a sodium-cooled fast reactor (SFR). (author)

  11. Experimental and numerical reaction analysis on sodium-water chemical reaction field

    International Nuclear Information System (INIS)

    Deguchi, Yoshihiro; Takata, Takashi; Yamaguchi, Akira; Kikuchi, Shin; Ohshima, Hiroyuki

    2015-01-01

    In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using an elementary reaction analysis. A quasi one-dimensional flame model is applied to a sodium-water counter-flow reaction field. The analysis contains 25 elementary reactions, which consist of 17 H_2-O_2 and 8 Na-H_2O reactions. Temperature and species concentrations in the counter-flow reaction field were measured using laser diagnostics such as LIF and CARS. The main reaction in the experimental conditions is Na+H_2O → NaOH+H and OH is produced by H_2O+H → H_2+OH. It is demonstrated that the reaction model in this study well explains the structure of the sodium-water counter-flow diffusion flame. (author)

  12. Large sodium water reaction calculations in a LMFBR steam generator

    International Nuclear Information System (INIS)

    Finck, P.; Lepareux, M.; Schwab, B.; Blanchet, Y.

    1986-05-01

    The French approach to the analysis of large and violent sodium water reactions is presented. The basis for choosing the Design Basis Accident is discussed. An energetical analysis of the physical phenomena involved stresses the specific needs for computing tools. The feature of these tools are then described, and a validation test is presented. Finally, industrial applications are described. 8 refs

  13. Application of laser diagnostics to sodium-water chemical reaction field

    International Nuclear Information System (INIS)

    Deguchi, Yoshihiro; Tamura, Kenta; Muranaka, Ryota; Kusano, Koji; Kikuchi, Shin; Kurihara, Akikazu

    2013-01-01

    In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes in a steam generator. Therefore the study on sodium-water chemical reactions is of paramount importance for safety reasons. This study aims to clarify the sodium-water reaction mechanisms using laser diagnostics. The sodium-water counter-flow reactions were measured using laser diagnostics such as laser induced fluorescence, CARS, Raman scattering and photo-fragmentation. The measurement results show that the sodium-water reaction proceeds mainly by the reaction Na + H 2 O → NaOH + H and the main product is NaOH in this reaction. Its forward and backward reaction rates tend to balance with each other and the whole reaction rate reduces as temperature increases. (author)

  14. Wastage of Steam Generator Tubes by Sodium-Water Reaction

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  15. Adiabatic flame temperature of sodium combustion and sodium-water reaction

    International Nuclear Information System (INIS)

    Okano, Y.; Yamaguchi, A.

    2001-01-01

    In this paper, background information of sodium fire and sodium-water reaction accidents of LMFBR (liquid metal fast breeder reactor) is mentioned at first. Next, numerical analysis method of GENESYS is described in detail. Next, adiabatic flame temperature and composition of sodium combustion are analyzed, and affect of reactant composition, such oxygen and moisture, is discussed. Finally, adiabatic reaction zone temperature and composition of sodium-water reaction are calculated, and affects of reactant composition, sodium vaporization, and pressure are stated. Chemical equilibrium calculation program for generic chemical system (GENESYS) is developed in this study for the research on adiabatic flame temperature of sodium combustion and adiabatic reaction zone temperature of sodium-water reaction. The maximum flame temperature of the sodium combustion is 1,950 K at the standard atmospheric condition, and is not affected by the existence of moisture. The main reaction product is Na 2 O (l) , and in combustion in moist air, with NaOH (g) . The maximum reaction zone temperature of the sodium-water reaction is 1,600 K, and increases with the system pressure. The main products are NaOH (g) , NaOH (l) and H2 (g) . Sodium evaporation should be considered in the cases of sodium-rich and high pressure above 10 bar

  16. Acoustic detection for small-leak sodium-water reaction

    International Nuclear Information System (INIS)

    Nei, Hiromichi; Ohshima, Iwao; Ujihara, Kozaburo; Hori, Masao

    1977-01-01

    Characteristics of acoustic signal produced by sodium-water reaction due to steam injection and by Ar gas injection into sodium were experimentally investigated. Acoustic signal was measured by using Kistler 808A and 815A5 accelerometers. Root mean square (RMS) measurements and frequency analysis of the signal were conducted. The RMS measurements could detect a small water leakage into sodium, as small as 0.07g/sec, in the present loop. The peaks in a frequency spectrum were caused by the natural vibration of a rod on which the acoustic transducer was mounted. The RMS was approximately proportional to the one-third power of the steam leak rate and increased to some extent with the ambient sodium temperature. RMS values, both for sodium-water reaction and Ar gas injection, were about the same order of magnitude, when the data were plotted against the volumetric flow rates of steam and Argas. (auth.)

  17. Sodium water reaction R and D for French LMFBR

    International Nuclear Information System (INIS)

    Cambillard, E.; Finck, P.; Lapicore, A.; Simeon, C.

    1985-01-01

    This paper presents the research and development which is underway for the French LMFBR steam generator safety study. The program comprises three major areas: (1) the analysis of realistic leaks, which includes the leak evolution and its consequences; (2) the response time of leak detection systems compared to leak propagation phenomena; and (3) the guillotine rupture (DBA) studies relative to source term evaluation by experimental/calculational approach and mechanical calculations. This program has provided information for the demonstrations of the steam generator safety in respect to a sodium-water reaction

  18. Analyses of hydrodynamic effects of large sodium-water reactions

    International Nuclear Information System (INIS)

    Sakano, K.; Shindo, Y.; Koishikawa, A.; Maekawa, I.

    1977-01-01

    Large leak sodium-water reactions that would occur in a steam generator of LMFBR causes abrupt changes of pressure and velocity of fluid in a secondary sodium system and relief system. This paper describes SOWACS-III together with its model and method. Results of analyses are also given, the comparison with experimental results of initial pressure spike being included. SOWACS-III treats the system which consists of the steam generator, vessel, valve, pump and pipe, and uses the following models and methods. (1) Components are assumed to be one-dimensional. (2) Pressure wave propagation near a reaction zone, where hydrogen is generated, is analyzed with the spherical co-ordinate (sphere-cylinder model). (3) A moving boundary is formed by contact of sodium with other fluid such as hydrogen and nitrogen. The boundary travels without mixing of sodium and another fluid through the boundary (boundary tracking model). The boundary can be treated not to move from the original place (fixed boundary model). (4) Pressure wave propagation is analyzed by the explicit method of characteristics in one-dimensional Eulerian co-ordinate. (5) Flow-induced force is analyzed by momentum balance. (6) The lateral motion of relief piping caused by the force is analyzed by NASTRAN code. Analyses were carried out for large sodium-water reaction experiments in SWAT-3 rig of PNC by using the sphere-cylinder model. The calculated pressure spike in the reaction vessel was compared with the measured one for a few milliseconds after water injection. The calculated value and measured one were 6.4 ata and 6.7 ata for peak pressure and 0.6 ms and 2.8 ms for rising time, respectively

  19. Pressure transients resulting from sodium-water reaction following a large leak in LMFBR steam generator

    International Nuclear Information System (INIS)

    Rajput, A.K.

    1984-01-01

    The study of sodium water reaction, following a large leak, concerns primarily with the estimation of pressure/flow transients that are developed in the steam generator and the associated secondary circuit. This paper describes the mathematical formulations used in SWRT (Sodium Water Reaction Transients) code developed to estimate such pressure transients for FBTR plant. The results, obtained using SWRT have been presented for a leak in economiser (20m from bottom water header) and for a leak in super heater portions. A time lag of 50 m sec was considered for rupture disc takes to burst once the pressure experienced by it exceeds the set value. Also described in annexure to this paper is the mathematical formulation for two phase transient flow for the better estimation of leak rate from the ruptured end of the damaged heat transfer tube. This leak model considers slip but assumes thermal equilibrium between the liquid and vapour phases

  20. Development of blow down and sodium-water reaction jet analysis codes-Validation by sodium-water reaction tests (SWAT-1R)

    International Nuclear Information System (INIS)

    Hiroshi Seino; Akikazu Kurihara; Isao Ono; Koji Jitsu

    2005-01-01

    Blow down analysis code (LEAP-BLOW) and sodium-water reaction jet analysis code (LEAP-JET) have been developed in order to improve the evaluation method on sodium-water reaction event in the steam generator (SG) of a sodium cooled fast breeder reactor (FBR). The validation analyses by these two codes were carried out using the data of Sodium-Water Reaction Test (SWAT-1R). The following main results have been obtained through this validation: (1) The calculational results by LEAP-BLOW such as internal pressure and water flow rate show good agreement with the results of the SWAT- 1R test. (2) The LEAP-JET code can qualitatively simulate the behavior of sodium-water reaction. However, it is found that the code has tendency to overestimate the maximum temperature of the reaction jet. (authors)

  1. Sodium-water reaction studies for MONJU steam generators

    International Nuclear Information System (INIS)

    Hori, M.; Sato, M.; Nei, H.; Harasaki, T.; Hishida, M.; Saito, T.

    1975-01-01

    The R and D results of the PNC's sodium-water reaction project are reviewed. The purposes of the project with the specific object for each test rig and computer code are given. The test items which should be investigated for the safety evaluation of the MONJU steam generators are discussed, and the status of the PNC's work on each item is described. The results on the small-leak wastage measurement are shown and the improved experimental equations to predict the wastage rate from the leak rate and the sodium temperature are given. The preliminary results on the wastage of tube bundle in the intermediate leak range are shown. The depth and the area of the wastage and also the wastage rate for each tube are shown graphically. The measured peak value of the initial pressure spike for the large leak is shown. The scatter of the data and its causes are discussed. The bubble growth rate estimated from the void probe measurement is presented. The results of the simulation experiment on the pressure wave propagation to the secondary circuit are given, comparing them with the prediction by the one-dimensional computer codes SWAC-5K and SWAC-5H. (author)

  2. Sodium-water reaction studies for MONJU steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Hori, M; Sato, M; Nei, H; Harasaki, T; Hishida, M; Saito, T

    1975-07-01

    The R and D results of the PNC's sodium-water reaction project are reviewed. The purposes of the project with the specific object for each test rig and computer code are given. The test items which should be investigated for the safety evaluation of the MONJU steam generators are discussed, and the status of the PNC's work on each item is described. The results on the small-leak wastage measurement are shown and the improved experimental equations to predict the wastage rate from the leak rate and the sodium temperature are given. The preliminary results on the wastage of tube bundle in the intermediate leak range are shown. The depth and the area of the wastage and also the wastage rate for each tube are shown graphically. The measured peak value of the initial pressure spike for the large leak is shown. The scatter of the data and its causes are discussed. The bubble growth rate estimated from the void probe measurement is presented. The results of the simulation experiment on the pressure wave propagation to the secondary circuit are given, comparing them with the prediction by the one-dimensional computer codes SWAC-5K and SWAC-5H. (author)

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

    International Nuclear Information System (INIS)

    Seino, Hiroshi; Hamada, Hirotsugu

    2004-03-01

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

  4. Improvement on reaction model for sodium-water reaction jet code and application analysis

    International Nuclear Information System (INIS)

    Itooka, Satoshi; Saito, Yoshinori; Okabe, Ayao; Fujimata, Kazuhiro; Murata, Shuuichi

    2000-03-01

    In selecting the reasonable DBL on steam generator (SG), it is necessary to improve analytical method for estimating the sodium temperature on failure propagation due to overheating. Improvement on sodium-water reaction (SWR) jet code (LEAP-JET ver.1.30) and application analysis to the water injection tests for confirmation of code propriety were performed. On the improvement of the code, a gas-liquid interface area density model was introduced to develop a chemical reaction model with a little dependence on calculation mesh size. The test calculation using the improved code (LEAP-JET ver.1.40) were carried out with conditions of the SWAT-3·Run-19 test and an actual scale SG. It is confirmed that the SWR jet behavior on the results and the influence to analysis result of a model are reasonable. For the application analysis to the water injection tests, water injection behavior and SWR jet behavior analyses on the new SWAT-1 (SWAT-1R) and SWAT-3 (SWAT-3R) tests were performed using the LEAP-BLOW code and the LEAP-JET code. In the application analysis of the LEAP-BLOW code, parameter survey study was performed. As the results, the condition of the injection nozzle diameter needed to simulate the water leak rate was confirmed. In the application analysis of the LEAP-JET code, temperature behavior of the SWR jet was investigated. (author)

  5. Sodium-Water Reaction approach and mastering for ASTRID Steam Generator design

    International Nuclear Information System (INIS)

    Saez, Manuel; Allou, Alexandre; Beauchamp, François; Bertrand, Carole; Rodriguez, Gilles; Menou, Sylvain; Prele, Gérard

    2013-01-01

    Conclusions: • Modular Steam Generator concept selected for ASTRID: → Brings flexibility for the expertise of failed modules after their removal; → Intrinsically limit the mechanical consequences of a postulated large Sodium-Water Reaction. • Sodium-Water-Air Reaction studies include both prevention and mitigation aspects, with dedicated tools to be developed through R&D. • Regarding Safety analysis, the possibility to move from the scenario of instantaneous failure of the whole Steam Generator tube bundle toward a scenario with sequenced failure needs to be investigated. • The Steam Generator is one of the key components in the Sodium-cooled Fast Reactor system for it provides an interface between sodium and water. The design objective for the Steam Generator is related to the improvement of mastering of Sodium-Water Reaction. • Potential Sodium-Water Reactions can be eliminated by adopting a Gas based Power Conversion System

  6. Numerical thermal-hydraulics study on sodium-water reaction phenomena

    International Nuclear Information System (INIS)

    Takashi, Takata; Akira, Yamaguchi

    2003-01-01

    A new computational program SERAPHIM (Sodium-watEr Reaction Analysis: PHysics of Interdisciplinary Multi-phase flow) is developed to investigate the Sodium-Water Reaction (SWR) phenomena based on parallel computation technology. A compressible three-fluid (liquid water, liquid sodium and mixture gas) and one-pressure model is adopted for multi-phase calculation. The Highly Simplified Maker And Cell (HSMAC) method considering with compressibility is implemented as the numerical solution. The Message-Passing Interface (MPI) is used for the parallel computation. Two types of reactions are considered for the SWR modeling; one is a surface reaction and the other is a gas phase reaction. The surface reaction model assumes that liquid sodium reacts with water vapor on the surface of liquid sodium. An analogy of heat transfer and mass transfer is applied in this model. Reaction heating vaporizes liquid sodium resulting in the gas phase reaction. The ab initio molecular orbital method is applied to investigate the reaction mechanism and evaluate the reaction rate described by the Arrhenius law. A performance of parallel computation is tested on the cluster-PC (16 CPUs) system. The execution time becomes 17.1 times faster in case of 16 CPUs. It seems promising that the SERAPHIM code is practicable for large-scale analysis of the SWR phenomena. Three-dimensional SWR analyses are also carried out to investigate the characteristics of the thermal-hydraulics with the SWR and an influence of initial pressure (0.2 MPa and 0.6 MPa) on an early stage of the SWR phenomenon. As a result, distribution of a gas region, in which water vapor or product of the SWR such as hydrogen and sodium hydroxide exits, velocity and high temperature region differs by 0.2 MPa and 0.6 MPa conditions. However, the maximum gas temperature has an upper bounding and is almost constant both in the analyses. The reason of the upper bounding is attributed to the fact that a hydrogen gas covers up a liquid

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

    International Nuclear Information System (INIS)

    Matal, O.

    1980-01-01

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

  8. Development of computer code on sodium-water reaction products transport

    International Nuclear Information System (INIS)

    Arikawa, H.; Yoshioka, N.; Suemori, M.; Nishida, K.

    1988-01-01

    The LMFBR concept eliminating the secondary sodium system has been considered to be one of the most promissing concepts for offering cost reductions. In this reactor concept, the evaluation of effects on reactor core by the sodium-water reaction products (SWRPs) during sodium-water reaction at primary steam generator becomes one of the major safety issues. In this study, the calculation code was developed as the first step of the processes of establishing the evaluation method for SWRP effects. The calculation code, called SPROUT, simulates the SWRPs transport and distribution in primary sodium system using the system geometry, thermal hydraulic data and sodium-water reacting conditions as input. This code principally models SWRPs behavior. The paper contain the modelings for SWRPs behaviors, with solution, precipation, deposition and so on, and the results and discussions of the demonstration calculation for a typical FBR plant eliminating the secondary sodium system

  9. Acoustic sodium-water reaction detection of the Phenix steam generators

    International Nuclear Information System (INIS)

    Carminati, M.; Martin, L.; Sauzaret, A.

    1990-01-01

    The systems for acoustic sodium-water reaction detection and hydrogen detection of the Phenix steam generators as well as systems for monitoring signals analysis and processing are described. It is reported that the results obtained during operation and calibration phases are very encouraging and that industrial equipment showing the same performance are being examined. 6 figs

  10. Control of sodium fires and sodium-water reactions in breeder reactors

    International Nuclear Information System (INIS)

    Foerster, K.; Ruloff, G.; Voss, J.

    1985-01-01

    The excellent neutronic and thermodynamic properties of sodium as a fast-reactor coolant are somewhat counterbalanced by its high oxygen affinity. Because incidents like sodium fires and sodium-water reactions cannot be absolutely excluded, their effects and preventive measures have to be investigated. Characteristics and counter-measures are discussed. (orig.) [de

  11. Japanese position paper on sodium-water reaction testing and design

    International Nuclear Information System (INIS)

    Sato, M.; Hiroi, H.; Tanabe, H.; Miyake, O.; Kuroha, M.; Hoshi, Y.

    1984-01-01

    PNC has been developing the steam generator with helically coiled heat transfer tube bundle and downcommer tubes for the prototype fast reactor Monju since 1968. To establish the safety design against the sodium-water reaction accident was one of the most important R and D items at the start of the development. PNC started the experimental study initially in the large leak region in 1970. Until now, during twelve years, the experimental studies have been performed, which covers the phenomena from a micro leak to a large one, with the use of the SWAT-1 rig, SWAT-2 loop, SWAT-3 loop, and SWAT-4 rigs. The reliable leak detection system is necessary to minimize the damage by the sodium-water reaction. Two groups of efforts have been paid for developing the detection system. One is to develop the leak detector itself, and another is to grasp the hydrogen transport behavior in the sodium in the steam generator and the secondary piping system. Four sodium loops have been used for the development. The development of computer codes has also progressed in parallel with the sodium-water reaction experiments. Three codes have been accomplished for the design tools against the sodium-water reaction. Through the efforts mentioned above, sufficient experiences were obtained for designing and operating the Monju steam generator system

  12. Some conditions affecting the definition of design basis accidents relating to sodium/water reactions

    International Nuclear Information System (INIS)

    Bolt, P.R.

    1984-01-01

    The possible damaging effects of large sodium/water reactions on the steam generator, IHX and secondary circuit are considered. The conditions to be considered in defining the design basis accidents for these components are discussed, together with some of the assumptions that may be associated with design assessments of the scale of the accidents. (author)

  13. Prediction of metal wastage produced by sodium-water reaction jets

    International Nuclear Information System (INIS)

    Payne, J.F.B.

    1979-01-01

    When a leak occurs in a sodium heated boiler, a sodium-water reaction jet is formed which causes further damage to the boiler, ie wastage. A correlation is developed which predicts wastage of ferritic steel boiler tubes for the range of leak sizes, sodium temperatures and leak to target spacing for which data available. (author)

  14. Unsteady aspects of sodium-water reaction. Water clearing of sodium containing equipments

    International Nuclear Information System (INIS)

    Carnevali, Sofia

    2012-01-01

    Sodium fast Reactor (FSR) is one of the most promising nuclear reactor concepts in the frame of Generation IV Systems to be commercialised in the next decades. One important safety issue about this technology is the highly exothermal chemical reaction of sodium when brought in contact with liquid water. This situation is likely, in particular during decommissioning, when sodium needs to be firstly converted ('destroyed') into non-reactive species. This is achieved by water washing: the major products are then gaseous hydrogen and corrosive soda. Today, such operations are performed in confined chambers to mitigate the consequences of any possible abnormal conditions. It has for long been believed that the main safety problem was the combustion of hydrogen in the surrounding air despite some pioneering works suggested that even without air the reaction could be explosive. It is extremely important to clarify the phenomenology of sodium-water interactions since available knowledge does not allow a robust extrapolation of existing data/model to full scale plants. The primary objective of this work is to identify and assess the details of the phenomenology, especially at the sodium/water interface, to isolate the leading mechanisms and to propose a robust and innovative modelling approach. A large body of yet unreleased experimental data extracted from the files of the French Commissariat a l'Energie Atomique (CEA) was collated and analysed on the basis of 'explosion' physics. Some additional experiments were also performed to fill some gaps, especially about the kinetics of the reaction. The results strongly suggest that the fast expansion of gas producing a blast wave in certain conditions is a kind of vapour explosion. It also appears that any potential hydrogen-air explosion should be strongly mitigated by the large quantity of water vapour emanating also from the reaction zone. The limitations of existing modelling approaches are clearly

  15. An Evaluation of the Acoustic Signal processing Techniques for Sodium-Water Reaction Detection in KALIMER-600

    International Nuclear Information System (INIS)

    Hur, Seop; Seong, S. H.; Kim, T. J.; Kim, S. O.; Lee, M. K.

    2005-02-01

    KALIMER-600 is a pool type fast breeder reactor using liquid sodium as a coolant. Although it has the several advantages such as long-term fuel cycle and enhanced safety concepts, it is possible to leak the secondary side water/steam into sodium boundary. This event could make the plant abnormal condition. One of the major design issues in KALIMER-600 is, therefore, to develop the system which can early detect the sodium-water reaction to protect the sodium-water reaction event. After evaluating the various signal processing techniques for passive acoustic leak detection, we have proposed the early leak detection logics. the signal processing techniques for evaluation were the spectral estimation using the linear modeling, the estimation error of linear modeling, the system adaptation rate using an adaptive signal processing, and the background noise cancellation using adaptive and fixed filtering. As the analysis results regarding the stationary and the cross-correlation of leak signals and background noises, the two signal systems met a wide-dense stationary process and there was only the week cross correlation relationship between two signals. It is ,therefore, possible to use the linear/harmonic modeling of signal systems, and the leak signal in sensor outputs can be discriminated. As the results of the evaluation of the various spectral estimation methods, the spectral estimation method based on autoregressive modeling was more practical comparing with other methods in the sodium-water reaction detection. The passive acoustic leak detection logics were suggested based on above evaluations. the logics consist of 3 levels; transient identification, leak determination and leak symptom identification. The simulation results using sodium-water reaction signals showed that it was possible to determine the leak at above -3dB of SNR, while between -3 dB and -10 dB of SNR the logics determined the leak symptom identification. The detection sensitivity can be enhanced

  16. Design of the US-CRBRP sodium/water reaction pressure relief system

    International Nuclear Information System (INIS)

    Kruger, G.B.; Murdock, T.B.; Rodwell, E.; Sane, J.O.

    1976-01-01

    Protection against intermediate sodium system overpressure from the sodium/water reaction associated with large leaks within the CRBRP Steam Generators is provided by the sodium/water reaction pressure relief system (SWRPRS). This system consists of rupture disks connected to the intermediate sodium piping adjacent to the inlet to the superheater and outlet from the evaporator modules. The rupture discs relieve into piping that leads to reaction produce separator tanks, which in turn are vented to a centrifugal separator and flare stack arranged to burn hydrogen gas exhausting into the atmosphere. Analyses have been conducted using the TRANSWRAP Computer Code to predict the system pressures and flow rates during the large leak event. Experimental tests to be conducted in the large leak test rig (LLTR) will be used to confirm the analysis techniques used in the design

  17. Development of the SPIKE code for analysis of the sodium-water reaction

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Sung Tai; Park, Jin Ho; Choi, Jong Hyeun; Kim, Tae Joon [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-08-01

    In the secondary loop of liquid metal reactors, including SG, water leak into sodium causes the sudden increase of pressure by the H{sub 2} and heat generated from reaction. At few miliseconds after leak, a sharp and short-lived increase of pressure is generated and its propagation depends on the acoustic constraint characteristics of secondary loop. As increasing leak amount of water, another pressure increase is caused by H{sub 2} and its transients depends on the resistance of pressure opening system, such as rupture disc. For prediction of the transients of initial spike pressure, a code of SPIKE was developed. The code was based on the following simplifications and assumptions: combination of total and half release of H{sub 2} rate, spherical shape of H{sub 2} bubble, compressible and Newtonian fluid for sodium. The program was built in FOTRAN language and consisted of 5 modules. Several sample calculations were performed to test the code and to determine the scale down factor of experimental facilities for experimental verification of the code: parameter study of the variables in chemical reaction model, comparison study with results calculated by superposition methods for simple piping structures, comparison study with results calculated by previous researchers, and calculation for KALIMER models of various size. With these calculation results, the generally predicted phenomena of sodium water reaction can be explained and the calculated ones by SPIKE code were well agreed with the previous study. And the scale down factor can be determined. (author). 88 refs., 99 figs., 39 tabs.

  18. Experiences on removal of sodium-water reaction products in SWAT-3

    International Nuclear Information System (INIS)

    Tanabe, H.; Hiroi, H.; Sato, M.; Otaka, J.

    2002-01-01

    This report summarizes experiences and information concerning the removal of sodium water reaction products (SMRP) obtained through large leak tests of the Steam Generator Safety Test Facility (SWAT-3) at PNC/OEC, which were conducted to validate the safety design of steam generators of a prototype LMFBR Monju. The following three problems are discussed here: (1) drainability of SWRP, (2) removal of SWRP by using a cold trap, and (3) steam cleaning of SWRP. (author)

  19. A fundamental study on sodium-water reaction in the double-pool-type LMFBR

    International Nuclear Information System (INIS)

    Yoshida, Kazuo; Akimoto, Tokuzo

    1987-01-01

    In order to evaluate the pressure rise by large sodium-water reaction in the Double-Pool LMFBR, basic tests on pressure wave celerity in rectangular tube are carried out. The initial spike pressure in rectangular-shelled steam generator of the Double Pool reactor, strongly depends on pressure wave celerity. In this study, celerity was measured as a function of pressure wave rising time and pulse height, and influence of water around the test section on celerity was investigated. (author)

  20. Computational methodology of sodium-water reaction phenomenon in steam generator of sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Takata, Takashi; Yamaguchi, Akira; Uchibori, Akihiro; Ohshima, Hiroyuki

    2009-01-01

    A new computational methodology of sodium-water reaction (SWR), which occurs in a steam generator of a liquid-sodium-cooled fast reactor when a heat transfer tube in the steam generator fails, has been developed considering multidimensional and multiphysics thermal hydraulics. Two kinds of reaction models are proposed in accordance with a phase of sodium as a reactant. One is the surface reaction model in which water vapor reacts directly with liquid sodium at the interface between the liquid sodium and the water vapor. The reaction heat will lead to a vigorous evaporation of liquid sodium, resulting in a reaction of gas-phase sodium. This is designated as the gas-phase reaction model. These two models are coupled with a multidimensional, multicomponent gas, and multiphase thermal hydraulics simulation method with compressibility (named the 'SERAPHIM' code). Using the present methodology, a numerical investigation of the SWR under a pin-bundle configuration (a benchmark analysis of the SWAT-1R experiment) has been carried out. As a result, the maximum gas temperature of approximately 1,300degC is predicted stably, which lies within the range of previous experimental observations. It is also demonstrated that the maximum temperature of the mass weighted average in the analysis agrees reasonably well with the experimental result measured by thermocouples. The present methodology will be promising to establish a theoretical and mechanical modeling of secondary failure propagation of heat transfer tubes due to such as an overheating rupture and a wastage. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-06-15

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

  2. Fundamental study on temperature estimation of steam generator tubes at sodium-water reaction

    International Nuclear Information System (INIS)

    Furukawa, Tomohiro; Yoshida, Eiichi

    2008-11-01

    In case of the tube failure in the steam generator of the sodium cooled fast breeder reactor, its adjoined tubes are rapidly heated up by the chemical reaction between sodium and water/steam. And it is known that the tubes have the damage called 'wastage' by the disclosure steam jet. This research is a fundamental study based on the metallography about temperature estimation of the damaged tubes at the sodium-water reaction for the establishment of mechanism analysis technique of the behavior. In the examination, the material which gave the rapid thermal history which imitated sodium-water reaction was produced. And it was investigated whether the thermal history (i.e. maximum temperature and the holding time) of the samples could be presumed from the metallurgical examination of the samples. The major results are as follows: (1) The microstructure of the sample which was given the rapid thermal heating has reserved the influence of the maximum temperature and the time, and the structure can explain by referring to the equilibrium diagram and the continuous cooling transformation diagram. (2) Results of the electrolytic extraction of the samples, the ratio of the remained volume to the electrolyzed volume degreased with the increase of the maximum temperature and the time. Furthermore, it was observed the correlation between the remained volume of each element (Cr, Mo, Fe, V and Nb) and the thermal history. (3) It was obtained that the thermal history of the tubes damaged by sodium-water reaction might be able to be estimated from the metallurgical examinations. (author)

  3. Small leak detection by measuring surface oscillation during sodium-water reaction in steam generator

    International Nuclear Information System (INIS)

    Nei, Hiromichi; Hori, Masao

    1977-01-01

    Small leak sodium-water reaction tests were conducted to develop various kinds of leak detectors for the sodium-heated steam generator in FBR. The super-heated steam was injected into sodium in a reaction vessel having a sodium free surface, simulating the steam generator. The level gauge in the reaction vessel generated the most reliable signal among detectors, as long as the leak rates were relatively high. The level gauge signal was estimated to be the sodium surface oscillation caused by hydrogen bubbles produced in sodium-water reaction. Experimental correlation was derived, predicting the amplitude as a function of leak rate, hydrogen dissolution ratio, bubble rise velocity and other parameters concerned, assuming that the surface oscillation is in proportion to the gas hold-up. The noise amplitude under normal operation without water leak was increased with sodium flow rate and found to be well correlated with Froud number. These two correlations predict that a water leak in a ''MONJU'' class (300 MWe) steam generator could possibly be detected by level gauges at a leak rate above 2 g/sec. (auth.)

  4. SWAAM-LT: The long-term, sodium/water reaction analysis method computer code

    International Nuclear Information System (INIS)

    Shin, Y.W.; Chung, H.H.; Wiedermann, A.H.; Tanabe, H.

    1993-01-01

    The SWAAM-LT Code, developed for analysis of long-term effects of sodium/water reactions, is discussed. The theoretical formulation of the code is described, including the introduction of system matrices for ease of computer programming as a general system code. Also, some typical results of the code predictions for available large scale tests are presented. Test data for the steam generator design with the cover-gas feature and without the cover-gas feature are available and analyzed. The capabilities and limitations of the code are then discussed in light of the comparison between the code prediction and the test data

  5. Test results of sodium-water reaction testing in near prototypical LMR steam generator

    International Nuclear Information System (INIS)

    Boardman, C.E.; Hui, M.; Neely, H.H.

    1990-01-01

    An extensive test program has been performed in the United States to investigate the effects of large sodium-water reaction events in LMFBR steam generators. Tests were conducted in the Large Leak Test Rig (LLTR) located at the Energy Technology Engineering Center (ETEC). The program was divided into two phases, Series I and Series II, for the purpose of satisfying near-term and long-term needs. Series II was further subdivided into large and intermediate leak tests. This paper will emphasize the Series II intermediate leak tests and resulting conclusions for steam generator design and operation. 11 figs, 2 tabs

  6. Large scale sodium-water reaction tests for Monju steam generators

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  7. Analysis of the Sodium-Water Reaction Phenomena by Small Water/Steam Leaks

    International Nuclear Information System (INIS)

    Jeong, J-Y; Kim, T-J; Kim, J-M; Kim, B-H; Park, N-C

    2006-01-01

    One of the important problems to be solved in the design and construction of a sodium cooled fast reactor is to confirm the safety and reliability of the steam generator which transfers the heat from the sodium to the water. Sodium-water reaction events may occur when material faults such as a pinhole or cracks occur in the heat transfer tube wall. When such a leak occurs, evaporating water or superheated steam enters through a small leak into the sodium. The surface of this steam jet reacts with the surrounding sodium. Due to turbulence, sodium and particles of the reaction products are drawn at a high velocity into the jet. Impingement of these particles on an adjacent tube is followed by a combined process of a corrosion and erosion which results in a local weakening of the affected tube. If there is no reliable detection available in time, wastage will ultimately result in an additional leak in the adjacent tube. Therefore, it is very significant to predict these phenomena quantitatively from the view of designing a steam generator and its leak detection systems. The objective of this study is a basic investigating of the sodium-water reaction phenomena by small water/steam leaks

  8. Acoustic signal processing for the detection of sodium boiling or sodium-water reaction in LMFRs. Final report of a co-ordinated research programme 1990-1995

    International Nuclear Information System (INIS)

    1997-05-01

    This report is a summary of the work performed under a co-ordinated research programme entitled Acoustic Signal Processing for the Detection of Sodium Boiling or Sodium-Water Reaction in Liquid Metal Cooled Fast Reactors. The programme was organized by the IAEA and carried out from 1990 to 1995. It was the continuation of an earlier research co-ordination programme entitled Signal Processing Techniques for Sodium Boiling Noise Detection, which was carried out from 1984 to 1989. Refs, figs, tabs

  9. The improvement of the heat transfer model for sodium-water reaction jet code

    International Nuclear Information System (INIS)

    Hashiguchi, Yoshirou; Yamamoto, Hajime; Kamoshida, Norio; Murata, Shuuichi

    2001-02-01

    For confirming the reasonable DBL (Design Base Leak) on steam generator (SG), it is necessary to evaluate phenomena of sodium-water reaction (SWR) in an actual steam generator realistically. The improvement of a heat transfer model on sodium-water reaction (SWR) jet code (LEAP-JET ver.1.40) and application analysis to the water injection tests for confirmation of propriety for the code were performed. On the improvement of the code, the heat transfer model between a inside fluid and a tube wall was introduced instead of the prior model which was heat capacity model including both heat capacity of the tube wall and inside fluid. And it was considered that the fluid of inside the heat exchange tube was able to treat as water or sodium and typical heat transfer equations used in SG design were also introduced in the new heat transfer model. Further additional work was carried out in order to improve the stability of the calculation for long calculation time. The test calculation using the improved code (LEAP-JET ver.1.50) were carried out with conditions of the SWAT-IR·Run-HT-2 test. It was confirmed that the SWR jet behavior on the result and the influence to the result of the heat transfer model were reasonable. And also on the improved code (LEAP-JET ver.1.50), user's manual was revised with additional I/O manual and explanation of the heat transfer model and new variable name. (author)

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  11. Large-leak sodium-water reaction analysis for steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Sakano, K; Shindo, Y; Hori, M

    1975-07-01

    The guillotine rupture of 4 tubes is assumed as a design basis regarding the large-leak sodium-water reaction in the system of the MONJU steam generator. Three kinds of analyses were performed with the view to showing the integrity of the steam generator system on the reaction. The first one is the analysis of the initial pressure spike, assuming the initial guillotine rupture of 1 tube. The analysis was performed by utilizing one-dimensional sphere-cylinder model code SWAC-7 and two-dimensional axisymmetric code PISCES 2DL. The second one is the analysis of the secondary peak pressure and its propagation in the system, assuming the instantaneous guillotine rupture of 4 tubes. The third one is the analysis of the dynamic deformation of the steam generator shell. The integrity of the steam generator system was shown by the analyses. (author)

  12. Large-leak sodium-water reaction analysis for steam generators

    International Nuclear Information System (INIS)

    Sakano, K.; Shindo, Y.; Hori, M.

    1975-01-01

    The guillotine rupture of 4 tubes is assumed as a design basis regarding the large-leak sodium-water reaction in the system of the MONJU steam generator. Three kinds of analyses were performed with the view to showing the integrity of the steam generator system on the reaction. The first one is the analysis of the initial pressure spike, assuming the initial guillotine rupture of 1 tube. The analysis was performed by utilizing one-dimensional sphere-cylinder model code SWAC-7 and two-dimensional axisymmetric code PISCES 2DL. The second one is the analysis of the secondary peak pressure and its propagation in the system, assuming the instantaneous guillotine rupture of 4 tubes. The third one is the analysis of the dynamic deformation of the steam generator shell. The integrity of the steam generator system was shown by the analyses. (author)

  13. Analyses for experiment on sodium-water reaction temperature by the CHAMPAGNE code

    International Nuclear Information System (INIS)

    Yoshioka, Naoki; Kishida, Masako; Yamada, Yumi

    2000-03-01

    In this work, analyses on sodium-water reaction temperature in the new SWAT-1(SWAT-1R) test were completed by the CHAMPAGNE code in order to understand void and velocity distribution in sodium system, which was difficult to be measured in experiments. The application method of the RELAP5/Mod2 code was investigated to LMFBR steam generator (SG) blow down analysis, too. The following results were obtained. (1) Analyses on sodium-water reaction temperature in the SWAT-1R test. 1) Analyses were carried out for the SWAT-1R test under the condition water leak rate 600 g/s by treating the pressure loss coefficient, the interface friction coefficient and the coefficient related to reaction rate as parameters. The effect and mechanism of each parameter on the shape of reaction zone were well understood by these analyses. 2) The void and velocity distribution in sodium system were estimated by use of the most suitable parameters. These analytical results are expected to be useful for planning of the SWAT-1R test and evaluation of test result. (2) Investigation of the RELAP5/Mod2 code. 1) The items to be improved in the RELAP5/Mod2 code were clarified to apply this code to the FBR SG blow down analysis. 2) One of these items was an addition of the shell-side (sodium-side) model. A sodium-side model was designed and added to the RELAP5/Mod2 code. Test calculations were carried out by this improved code and the basic function of this code was confirmed. (author)

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  15. An experimental study on sodium-water reaction in the double pool LMFBR, (4)

    International Nuclear Information System (INIS)

    Kumagai, Hiromichi; Yoshida, Kazuo; Uotani, Masaki; Akimoto, Tokuzo

    1989-01-01

    Double Pool type LMFBR set the rectangular cross-sectional steam generator (SGs) inside a secondary vessel. The initial spike pressure rise caused by large sodium-water reaction in SGs might be radiated into a large sodium pool in the secondary vessel. Therefore basic experiments on pressure wave propagation were carried out by generating pressure wave in water by mean of a set of drop hummer and piston. But the experimental apparatus in water was not convenience to simulate the structure near the bottom end of the SGs shell. In this reports, experiments were carried out by generating pulse sound pressure in air, and compared with the results pressure waves in water. (author)

  16. Experimental investigation of solid sodium-water reaction: tests results and phenomenological analysis

    International Nuclear Information System (INIS)

    Daudin, K.; Beauchamp, F.; Proust, C.

    2014-01-01

    Sodium-Water Reaction (SWR) is an issue one has to be capable to deal with for the next generation of nuclear reactors (SFR for GEN IV). The background of these experiments is the improvement of safety demonstration regarding SWR in an open volume. This experimental campaign is conducted at the CEA Cadarache inside a cylindrical reactor filled with inert gas. The sodium is inside a loading pot and water comes into contact by immersion. SWR and its physical effects are followed by different pressure and temperature sensors. The results show a limit to the overpressure increasing sodium mass. Global assessment of physical effects of SWR contributes to put forward the relative nature of phenomena with geometric configuration, and the importance of scale effects. (authors)

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

    International Nuclear Information System (INIS)

    Nei, Hiromichi

    1978-01-01

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

  18. SNR-steam generator design with respect to large sodium water reactions

    International Nuclear Information System (INIS)

    Jong, J.J. de; Kellner, A.; Florie, C.J.L.

    1984-01-01

    This paper deals with the experiences gained during the licensing procedure for the steam generators for the SNR 300 LMFBR regarding large sodium-water reactions. A description is given of the different calculations executed to investigate the effects of large leaks on the 85 MW helical coiled and straight tube steam generators. The investigations on the helical coiled steam generators are divided in the formulations of fluid behaviour, dynamic force calculations, dynamic response calculation and finally stress analyses. Several results are shown. The investigations on the straight tube steam generators are performed using models describing fluid-structure interaction, coupled with stress analyses. Several results are presented. A description is given of the problems and necessary construction changes during the licensing process. Advises are given for future analyses and design concepts for second generation commercial size LMFBR steam generators with respect to large leaks; based on the experience, gained with SNR 300, and using some new calculations for SNR 2. (author)

  19. Ultrasonic inspection for wastage in the LMFBR steam generator due to sodium--water reactions

    International Nuclear Information System (INIS)

    Neely, H.H.; Renger, L.

    1977-01-01

    As part of a program to study the results of large sodium-water reactions in the LMFBR Steam Generator, a boreside ultrasonic inspection device was developed to measure the wall thickness and diameter of the 2- 1 / 4 Cr-1 Mo, 0.397 in. I.D. steam tubes. The reaction was created in a near prototype steam generator by guillotine-type rupture of a steam tube, while the generator was at operating conditions. Wastage occurred on the surrounding tubes due to the high temperature reaction. The UT test instrument was designed to operate with a 15 MHz transducer in the pulse-echo shear-wave mode, with a sampling rate of 10 4 /sec. System outputs are diameter, wall thickness, attitude and axial position of the transducer. All are displayed digitally and may be recorded. Measurements are fed into a computer for later retrieval, and/or cascaded outputs into an x-y recorded displaying either out-of-limit or thickness data. The UT data taken in this experiment were consistent with physical measurements on a tube which was removed from the generator after the test. A machined flat 1 / 8 -inch long and 0.002-inch deep could readily be detected

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

    International Nuclear Information System (INIS)

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

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

  1. Thermal analysis experiment for elucidating sodium-water chemical reaction mechanism in steam generator of sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Kikuchi, Shin; Kurihara, Akikazu; Ohshima, Hiroyuki

    2012-01-01

    For the purpose of elucidating the mechanism of the sodium-water surface reaction in a steam generator of sodium-cooled fast reactors, kinetic study of the sodium (Na)-sodium hydroxide (NaOH) reaction has been carried out by using Differential Thermal Analysis (DTA) technique. The parameters, including melting points of Na and NaOH, phase transition temperature of NaOH, Na-NaOH reaction temperature, and decomposition temperature of sodium hydride (NaH) have been identified from DTA curves. Based on the measured reaction temperature, rate constant of sodium monoxide (Na 2 O) generation was obtained. Thermal analysis results indicated that Na 2 O generation at the secondary overall reaction should be considered during the sodium-water reaction. (author)

  2. A fundamental study on sodium-water reaction in the double pool LMFBR, (3)

    International Nuclear Information System (INIS)

    Uotani, Masaki; Kumagai, Hiromichi; Nishi, Yoshihisa; Yoshida, Kazuo

    1989-01-01

    The double pool LMFBR is an innovative reactor that Central Research Institute of Electric Power Industry proposed for the purpose of reducing the construction cost of FBRs, and it is characterized by immersing steam generators in the annular plenum formed between the primary vessel and the outer secondary vessel. Therefore, it is expected that the pressure behavior at the time of sodium-water reaction due to the breaking of heating tubes is largely different from the case of steam generators of conventional FBRs. In order to ensure the soundness of the primary vessel that containes the reactor core, it is necessary to sufficiently grasp the pressure behavior in the plenum, and this basic experiment and analysis are related to the pressure behavior due to piston motion that arises in the initial period of quasi-steady pressure. About 1/10 scale annular plenum was used, and the generation of reaction product gas was simulated by the release of nitrogen. When gas was released in the plenum, the highest pressure rise occurred in the initial period of release, and thereafter, periodic variation arose. The pressure waveform and the value of pressure rise as the results of the model analysis agreed well with the measured results. (K.I.)

  3. Analysis of acoustic data from UK sodium/water reaction test facilities

    International Nuclear Information System (INIS)

    Rowley, R.; Mcknight, J.A.; Airey, J.

    1990-01-01

    This paper describes acoustic measurements made during a number of sodium/water reaction experiments in the UK. The tests have included water and steam injections through both realistic (fatigue crack) defects and machined orifices and have covered a range of experimental conditions including those appropriate to the inlet and outlet regions of the EFR steam generators. Injection rates were typically in the range 0.1 to 30 g/s. Where possible, gas injections were also included in the test programme for comparison, since it is anticipated that a practical SGU acoustic leak detection system would include a facility for gas injections to allow system calibration, and to confirm transmission properties within the SGU. The test sections were instrumented with accelerometers on waveguides and in some cases included an under-sodium microphone situated about 300mm above the reaction zone. Tape recordings were made during the tests and used for detailed analysis off-line, although an audible output from one of the acoustic channels was used to monitor the progress of the injections and provide information for the rig operators. A comparison of the signal amplitudes measured during the experiments with typical reactor background noise was made and an estimate of the detection sensitivity of an acoustic monitoring system was deduced. 3 refs, 5 figs, 1 tab

  4. Sodium/water reaction detection confirmation and location with time domain beam former

    International Nuclear Information System (INIS)

    Cornu, C.

    1997-01-01

    The CEA studied the validity of a time beamforming method for the detection and location of Sodium/water reaction in steam generators of breeder reactors. In the context of the RCM, we apply this method on recorded data during a water injection in Sodium in ASB loop, artificially mixed with PFR background. Despite the severity of experiment conditions (the signal to noise ratio is between -6 and -24 dB). We show that the employed method completed with a low frequency pass band filter allows us to locate the injection with a precision of 30% of the diameter of the loop. Using the method in the course of time allows us to coarsely locate the start time and the duration of the leak. The good functioning of the method is however perturbed by uncertainty about the wave celebrity in the sodium about wave propagation in waves guides that are mounted with the sensors and in the structure of the loop. (author). 1 ref., 8 figs

  5. Development of analysis model for mid and long-term effects of sodium water reaction event in LMR

    International Nuclear Information System (INIS)

    Eoh, Jae Hyuk; Sim, Yoon Sub; Kim, Seong O; Kim, Yeon Sik; Kim, Eui Kwang; Wi, Myung Hwan

    2002-04-01

    The Sodium-Water Reaction(SWR) is important in the design consideration of a LMR steam generator. To develop the analysis code for long-term effects of SWR, investigation on the characteristics of various SWR analysis code and the assessment of an analysis model for long term effects were performed. In an event of SWR, pressure spikes of wave propagation occur at its initial stage and last for a very short time, and then bulk motion of fluid and reaction products is progressed and lasts for a long time. In a case SWR occurs, a number of hydrogen bubbles produced and sodium is entrained into the bubbles through the gas-liquid bubble interfaces by evaporation or diffusion. The partial pressure of the sodium in a hydrogen bubble is determined as a function of the bubble size, temperature, and pressure, and is rapidly decreased as its size increased. From this, it can be considered that the bulk motion in the later phase of SWR is an axial motion caused by expansion of a single-phase hydrogen gas bubble produced by a reaction in the vicinity of the leak site. Through this investigation, a preliminary simple analysis model for long-term effects of SWR was set up and sensitivity study using the system design parameters such as pressure and temperature of IHTS for KALIMER was performed. Also, a simpler analysis model using the cover gas pressure change related to the production of a hydrogen bubble in a steam generator was developed from the analyses results. These simple analysis models of the reaction site and the pressure behavior with hydrogen production can be used to develop the mid and long-term analysis code for SWR in the KALIMER steam generator design

  6. Improvement and test calculation on basic code or sodium-water reaction jet

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Yoshinori; Itooka, Satoshi [Advanced Reactor Engineering Center, Hitachi Works, Hitachi Ltd., Hitachi, Ibaraki (Japan); Okabe, Ayao; Fujimata, Kazuhiro; Sakurai, Tomoo [Consulting Engineering Dept., Hitachi Engineering Co., Ltd., Hitachi, Ibaraki (Japan)

    1999-03-01

    In selecting the reasonable DBL (design basis water leak rate) on steam generator (SG), it is necessary to improve analytical method for estimating the sodium temperature on failure propagation due to overheating. Improvement on the basic code for sodium-water reaction (SWR) jet was performed for an actual scale SG. The improvement points of the code are as follows; (1) introduction of advanced model such as heat transfer between the jet and structure (tube array), cooling effect of the structure, heat transfer between analytic cells, and (2) model improvement for heat transfer between two-phase flow and porous-media. The test calculation using the improved code (LEAP-JET ver.1.30) were carried out with conditions of the SWAT-3{center_dot}Run-19 test and an actual scale SG. It is confirmed that the SWR jet behavior on the results is reasonable and Influence to analysis result of a model. Code integration with the blow down analytic code (LEAP-BLOW) was also studied. It is suitable that LEAP-JET was improved as one of the LEAP-BLOW's models, and it was integrated into this. In addition to above, the improvement for setting of boundary condition and the development of the interface program to transfer the analytical results of LEAP-BLOW have been performed in order to consider the cooling effect of coolant in the tube simply. However, verification of the code by new SWAT-1 and SWAT-3 test data planned in future is necessary because LEAP-JET is under development. And furthermore advancement needs to be planned. (author)

  7. Improvement and test calculation on basic code or sodium-water reaction jet

    International Nuclear Information System (INIS)

    Saito, Yoshinori; Itooka, Satoshi; Okabe, Ayao; Fujimata, Kazuhiro; Sakurai, Tomoo

    1999-03-01

    In selecting the reasonable DBL (design basis water leak rate) on steam generator (SG), it is necessary to improve analytical method for estimating the sodium temperature on failure propagation due to overheating. Improvement on the basic code for sodium-water reaction (SWR) jet was performed for an actual scale SG. The improvement points of the code are as follows; (1) introduction of advanced model such as heat transfer between the jet and structure (tube array), cooling effect of the structure, heat transfer between analytic cells, and (2) model improvement for heat transfer between two-phase flow and porous-media. The test calculation using the improved code (LEAP-JET ver.1.30) were carried out with conditions of the SWAT-3·Run-19 test and an actual scale SG. It is confirmed that the SWR jet behavior on the results is reasonable and Influence to analysis result of a model. Code integration with the blow down analytic code (LEAP-BLOW) was also studied. It is suitable that LEAP-JET was improved as one of the LEAP-BLOW's models, and it was integrated into this. In addition to above, the improvement for setting of boundary condition and the development of the interface program to transfer the analytical results of LEAP-BLOW have been performed in order to consider the cooling effect of coolant in the tube simply. However, verification of the code by new SWAT-1 and SWAT-3 test data planned in future is necessary because LEAP-JET is under development. And furthermore advancement needs to be planned. (author)

  8. Experimental study of the attenuation waves oriented to transients caused by the sodium-water explosive reaction in fast reactors

    International Nuclear Information System (INIS)

    Pedroso, L.J.

    1990-01-01

    One of the problems related to fluid-structure interaction that can compromise the structural integrity of components of a fast reactor is the explosion caused by the sodium-water reaction, in the case of a flood at the level of the thermic exchange wall at the steam generator. In this paper we have considered the aspects of the pressure-waves damping caused by the reaction, when these waves transverse certain perforated structures. In order to solve this problem, we also adopted a parametric experimental approach, using a scale model (RIO test rig). (author)

  9. Dynamic loadings of sodium-water reactions in LMFBR and fusion power designs

    Energy Technology Data Exchange (ETDEWEB)

    Chan, C. K.

    1977-07-01

    In liquid metal fast breeder reactor and lithium cooled fusion reactor, a sodium loop is being proposed to transfer heat from the primary coolant loop to the steam turbine cycle. Although by careful design and quality assurance programs, the probability for steam generator tube failure can be minimized, failure will still occur. The direct contact of sodium and water would cause a chemical reaction where hydrogen and sodium compounds are produced. This paper presents an evaluation of the potential hazards as a result of such a reaction. An analytical method is developed to investigate the extent of the reaction zone and the propagation of the pressure wave in the sodium system. In the calculation, the chemical reaction is assumed to be instantaneous, governed by the equation 2Na(l)+H/sub 2/O(l)..-->..Na/sub 2/O(l)+H/sub 2/(g)+31.4 K cal/gm. mole. Both the temperature and pressure rise in the reaction zone can be established from the energy balance and the equation of state for the gaseous product. As a consequence of the energy released, the chemical products suddenly expand with a high velocity. The expansion also generates a shock wave in both the water and the sodium systems. Results indicate that the reaction zone can expand in a rate of 1500 ft/sec and a shock wave with initial strength of 2300 atmospheres propagates with a speed of 8000 ft/sec into the sodium system. The propagating characteristics of the shock wave are obtained by solving the basic fluid equations. The shock wave decays rapidly, in the neighborhood of milliseconds, as soon as the reaction zone stops to expand. The decrease in the reaction zone pressure allows more water to react with the sodium and a second pulse is generated.

  10. Dynamic loadings of sodium-water reactions in LMFBR and fusion power designs

    International Nuclear Information System (INIS)

    Chan, C.K.

    1977-01-01

    In liquid metal fast breeder reactor and lithium cooled fusion reactor, a sodium loop is being proposed to transfer heat from the primary coolant loop to the steam turbine cycle. Although by careful design and quality assurance programs, the probability for steam generator tube failure can be minimized, failure will still occur. The direct contact of sodium and water would cause a chemical reaction where hydrogen and sodium compounds are produced. This paper presents an evaluation of the potential hazards as a result of such a reaction. An analytical method is developed to investigate the extent of the reaction zone and the propagation of the pressure wave in the sodium system. In the calculation, the chemical reaction is assumed to be instantaneous, governed by the equation 2Na(l)+H 2 O(l)→Na 2 O(l)+H 2 (g)+31.4 K cal/gm. mole. Both the temperature and pressure rise in the reaction zone can be established from the energy balance and the equation of state for the gaseous product. As a consequence of the energy released, the chemical products suddenly expand with a high velocity. The expansion also generates a shock wave in both the water and the sodium systems. Results indicate that the reaction zone can expand in a rate of 1500 ft/sec and a shock wave with initial strength of 2300 atmospheres propagates with a speed of 8000 ft/sec into the sodium system. The propagating characteristics of the shock wave are obtained by solving the basic fluid equations. The shock wave decays rapidly, in the neighborhood of milliseconds, as soon as the reaction zone stops to expand. The decrease in the reaction zone pressure allows more water to react with the sodium and a second pulse is generated

  11. Simulation experiments for a large leak sodium-water reaction analysis. Volume 4. IHTS/relief system simulation tests

    International Nuclear Information System (INIS)

    Ploeger, D.W.

    1978-09-01

    Tests were performed in which a simplified 1/8-scale model of the intermediate heat transfer system and relief system of a LMFBR was subjected to a simulated sodium-water reaction in a steam generator. Pressures in the intermediate heat exchanger (IHX) and in the pipe were measured. The flow of water through the relief system was photographed and its velocity was measured. The forces on the relief system elbows resulting from the fluid flow were also measured. The tests were performed primarily to validate pulse propagation codes used for design and for direct use as design data

  12. Plan for support of large-plant (post-CRBR) needs in large-leak sodium-water reaction area

    International Nuclear Information System (INIS)

    Whipple, J.C.

    1980-03-01

    Work in the large leak test and analysis area of steam generator development has been carried out at GE-ARSD under 189a SG037 since 1973. The currently planned master schedule for the SG037 program is shown. Principal activities are the large leak testing program being carried out at the Large Leak Test Rig and the analysis methods development. The plan for supporting the large plant (post-CRBR) needs in the large leak sodium-water reaction area is outlined. Most of the needs will be answered in the current SG037 large leak program

  13. An experimental study on impingement wastage of Mod 9Cr 1Mo steel due to sodium water reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kishore, S., E-mail: skishore@igcar.gov.in [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Ashok Kumar, A.; Chandramouli, S.; Nashine, B.K.; Rajan, K.K.; Kalyanasundaram, P.; Chetal, S.C. [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Sodium heated steam generators are crucial components of fast breeder reactors. Black-Right-Pointing-Pointer A leak in steam generator tube will cause sodium water reaction that damages the tubes. Black-Right-Pointing-Pointer Experimental study was conducted to quantify the extent of damage on Mod 9Cr 1Mo tube due to a water leak. - Abstract: Sodium heated steam generator (SG) is a crucial component in the heat transport system of a fast breeder reactor (FBR). In case, one of its water/steam carrying tubes becomes defective, water/steam leaks into sodium, flowing in the shell side, causing sodium-water reaction, which is highly exothermic and producing corrosive NaOH. The reaction jet originating from a leaking tube may impinge on its adjacent tube, resulting in damage of the tube. Impingement wastage refers to this kind of damage, occurring to a tube of sodium heated SG, owing to a small water/steam leak from a neighboring tube. Extensive research works have been conducted all over the world to study various aspects of this phenomenon. Experimental studies were carried out in Indira Gandhi Centre for Atomic Research (IGCAR) to understand the effect of impingement wastage on Mod 9Cr 1Mo, which is the tube material of prototype fast breeder reactor (PFBR) SG. This paper brings out the data and experience gained through the experiments.

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

    International Nuclear Information System (INIS)

    Ruloff, G.

    1990-01-01

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

  15. The UK contribution to the sodium-water reaction R and D programme in support of EFR

    International Nuclear Information System (INIS)

    Currie, R.; McCrindle, K.B.; Wright, P.J.

    1990-01-01

    The sodium-water reaction R and D programme for European Fast Reactor (EFR), is an integrated European project, as described in another paper at this Specialists Meeting. In this paper the UK contribution to this programme is described. The major sodium-water reaction test facility in the UK is the Super Noah Rig at Dounreay. This Rig is currently being modified to allow the following to be achieved during experiments: Provision of water/steam at the correct EFR Steam Generator Unit (SGU) flowrate, temperature and pressure in the 24 target tubes modelling the EFR SGU in the test section. Provision of sodium at the correct EFR SGU velocity, temperature and pressure through the test section modelling the EFR SGU during the experiments. Experiments in this facility to determine the leakrate at which overheating becomes important in various regions of the EFR SGU and to determine the damage caused by overheating will be the major UK contribution in the future. The modifications to the Rig and the future experimental programme are described. Several intermediate leak experiments have been carried out in the Super Noah Rig in the past, and the main results from them are summarized. These experiments have primarily been at PFR conditions but results have been obtained for 2.25 Cr 1Mo, 9 Cr 1 Mo and A800 steels, with and without internal water flow in the target tubes. During these previous experiments, the sodium was static and was at atmospheric pressure. Results from experiments carried out in the Small Water Leak Rig (SWLR) and the Small-Scale Test Facilities at Dounreay on microleak evolution, wastage of tubes and SGU walls, the behaviour of small leaks at the low temperature, bottom-tubeplate conditions and corrosion at sodium pool surfaces are presented. The future programme for these facilities is discussed. Fundamental experiments which have been carried out at Harwell on the behaviour of blocked microleaks are described. 2 refs, 15 figs, 1 tab

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

    International Nuclear Information System (INIS)

    Sato, Minoru

    1978-01-01

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

  17. Safety Evaluation for IHTS Integrity due to the Steam Generator Sodium-Water Reaction Event in the PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sang-Jun; Lee, Kwi Lim; Ha, Kwi-Seok; Lee, Seung Won; Jeong, Taekyeong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In this paper, the integrity of the IHTS and SG by the SWR event are evaluated using the SWAAMII code. A sodium has a chemical characteristics to rigorously react the water or steam and produce the high pressure waves and high temperature reaction heat. It has an excellent characteristics as a reactor coolant. But, there is an event to be considered in the sodium cooled fast reactor design. The Sodium-Water Reaction (SWR) event can be occurred by the water or steam leaks due to the break of the steam generator tubes. The propagated high pressure waves threathen the structural integrity of the affected Intermediate Heat Transport System (IHTS) and steam generator. If the IHTS pipes are failed, the sodium of the IHTS can be released to the containment building. To the peak pressure point of view, it is performed to evaluate the integrity of the major components due to the SWR event in the SG. The generated peak pressures due to the five SG tubes simultaneous break event are within the range of the design pressure for the SG, IHX and IHTS including the related pipes.

  18. Initial pressure spike and its propagation phenomena in sodium-water reaction tests for MONJU steam generators

    International Nuclear Information System (INIS)

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

    1977-01-01

    With the objective of demonstrating the safe design of steam generators for prototype LMFBR MONJU against the postulated large-leak accident, a number of large-leak sodium-water reaction tests have been conducted using the SWAT-1 and SWAT-3 rigs. Investigation of the potential effects of pressure load on the system is one of the major concerns in these tests. This paper reports the behavior of initial pressure spike in the reaction vessel, its propagation phenomena to the simulated secondary cooling system, and the comparisons with the computer code for one-dimensional pressure wave propagation problems. Both rigs used are the scaled-down models of the helically coiled steam generators of MONJU. The SWAT-1 rig is a simplified model and consists of a reaction vessel (1/8 scale of MONJU evaporator with 0.4 m dia. and 2.5 m height) and a pressure relief system i.e., a pressure relief line and a reaction products tank. On the other hand, the SWAT-3 rig is a 1/2.5 scale of MONJU SG system and consists of an evaporator (reaction vessel with 1.3 m dia. and 6.35 m height), a superheater, an intermediate heat exchanger (IHX), a piping system simulating the secondary cooling circuit and a pressure relief system. The both water injection systems consist of a water injection line with a rupture disk installed in front of injection hole and an electrically heated water tank. Choice of water injection rates in the scaled-down models is made based on the method of iso-velocity modeling. Test results indicated that the characteristics of the initial pressure spike are dominated by those of initial water injection which are controlled by the conditions of water heater and the size of water injection hole, etc

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

    International Nuclear Information System (INIS)

    Shimoyama, Kazuhito

    2004-03-01

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

  20. Sodium-water wastage and reactions program performed by general electric in support of the US. AEC LMFBR steam generator development

    International Nuclear Information System (INIS)

    Greene, D.A.

    1975-01-01

    This paper constitutes an interim report on the sodium-water reaction programs performed, using the GE-SOWAT, GE-SMALL LEAK BEHAVIOR RIG, and GE-PTTR facilities in support of LMFBR steam generator development and its application to the Clinch River Breeder Reactor Plant. Test data from these rigs are presented, including wastage data as a function of water injection rate, sodium temperature, and orifice geometry. Initial results for self-wastage of defects under prototypical conditions, and from proof-of-principle tests of a protected heat transfer tube concept are also presented. An analytical basis for wastage phenomena is suggested. (author)

  1. Sodium-water wastage and reactions program performed by general electric in support of the US. AEC LMFBR steam generator development

    Energy Technology Data Exchange (ETDEWEB)

    Greene, D A

    1975-07-01

    This paper constitutes an interim report on the sodium-water reaction programs performed, using the GE-SOWAT, GE-SMALL LEAK BEHAVIOR RIG, and GE-PTTR facilities in support of LMFBR steam generator development and its application to the Clinch River Breeder Reactor Plant. Test data from these rigs are presented, including wastage data as a function of water injection rate, sodium temperature, and orifice geometry. Initial results for self-wastage of defects under prototypical conditions, and from proof-of-principle tests of a protected heat transfer tube concept are also presented. An analytical basis for wastage phenomena is suggested. (author)

  2. Contribution to the prediction of sodium-water reactions effects: application to confinement losses inside a steam generator building of a sodium fast reactor

    International Nuclear Information System (INIS)

    Daudin, Kevin

    2015-01-01

    Study of sodium-water reaction (SWR) consequences in open air represents a challenge in the frame of safety assessments of sodium fast reactors (SFR). In case of major accident and to predict consequences of SWR, it is necessary to better appreciate phenomena and especially quantity and rate of the energy release. The objective is thus to strengthen the understanding of such reactions in order to predict with lore accuracy its consequences on mechanical equipment in the surroundings. This work focuses on three areas : research of accidental sequences, experimental investigation, and phenomenological analysis before the explosive contact. At first, a tree structure risk analysis with calculations of dangerous phenomena permitted to suggest how the contact between reactants may happen. Then, demonstrative experimental studies were performed to deepen some practical aspects of the phenomenology, like the influence of the way the reactants get in contact. Data analysis conducted to the development of a phenomenological model, implemented into a software platform for numerical simulations. Although numerous hypothesis, transient heat transfer consideration enables to reproduce experimental observations, especially the influence of mixing conditions (sodium mass and initial temperatures) on the phenomenology. This study of the premixing step of sodium-water explosion is relevant in the frame of current prediction methods of mechanical loadings on structures. (author) [fr

  3. Analysis of the dynamic response of a double rupture disc assembly to simulated sodium-water reaction pressure pulses

    International Nuclear Information System (INIS)

    Leonard, J.R.

    1980-03-01

    A series of double rupture disc experiments were conducted in 1979 to evaluate the dynamic response characteristics of this pressure relief apparatus. The tests were performed in a facility with water simulating sodium and rising pressure pulses representative of the pressure increase resulting from a water/steam leak from a steam generator into sodium in the intermediate heat transport system of a breeder reactor power plant. Maximum source pressures ranged in magnitude from 50 psi to 800 psi. Dynamic response characteristics of each of the two rupture discs were similar to those observed in larger scale sodium-water experiments conducted in the Series I and Series II Large Leak Test Program at the Energy Technology Engineering Center. The SRI double rupture disc dynamic behavior was found to be consistent and amendable to modelling in the TRANSWRAP II computer code. A series of correlations which represent rupture disc buckling parameters were developed for use in the TRANSWRAP II code. The semi-empirical modeling of the rupture discs in the TRANSWRAP II code showed very good agreement with the experimental results

  4. Conclusions from the sodium-water reaction experiments performed with a straight tube bundle model for a steam generator with respect to the calculation method of the accident design pressure

    International Nuclear Information System (INIS)

    Ludwig, P.W.P.; Ruijterman, C.

    1975-01-01

    This paper will give some conclusions, drawn from the big-leakages sodium-water reaction experiments, on the calculation methods to be used in determining the sodium blow down, the water supply and the bubble pressure. The necessity of taking into account the compressibility of sodium is demonstrated. (author)

  5. Conclusions from the sodium-water reaction experiments performed with a straight tube bundle model for a steam generator with respect to the calculation method of the accident design pressure

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, P W.P.; Ruijterman, C

    1975-07-01

    This paper will give some conclusions, drawn from the big-leakages sodium-water reaction experiments, on the calculation methods to be used in determining the sodium blow down, the water supply and the bubble pressure. The necessity of taking into account the compressibility of sodium is demonstrated. (author)

  6. Preliminary Study of Feasibility of Acoustic Detection of Small Sodium-Water Reactions in Lmfbr Steam Generators.

    Energy Technology Data Exchange (ETDEWEB)

    Chamberlain, H. V.

    1970-06-01

    An evaluation of acoustic techniques for the detection of sound resulting from water leaks into liquid sodium was conducted. Acoustic spectra over the range of 100Hz to 80kHz were detected. A leak as small as 0.00008 lb/ sec was detected by the acoustic instrumentation. The indicated leak rate was the smallest that was injected into the liquid sodium, and is not to be interpreted as the smallest leak rate that might be detected by the acoustic method. Detection time was found to be essentially instantaneous.

  7. Development of experimental method for self-wastage behavior in sodium-water reaction. Development of test rig (SWAT-2R) and study for experimental procedure

    International Nuclear Information System (INIS)

    Abe, Yuta; Shimoyama, Kazuhito; Kurihara, Akikazu

    2014-07-01

    In case of water leak from a penetrated crack on a tube of steam generator in the sodium cooled fast reactor (SFR), self-wastage, that increases the size of leak, may take place by corrosion related to chemical reaction between sodium and water. If the self-wastage continues in a certain period of time, the intact tube bundle may be damaged as a result of enlarged leak. For the safety evaluation of the accident, JAEA has been developing the analytical method of self-wastage using the multi-dimensional sodium-water reaction code. Experiments conducted so far used mainly crack-type test pieces. However, reproducibility was limited and it was difficult to evaluate individual effects of the phenomena in detail. This report describes the development of new experimental rig (SWAT-2R). SWAT-2R enables to examine corrosion effecting factors that were ambiguous in the previous studies. The report includes description of development of micro-leak test piece, examination of experimental procedure. The results will provide fundamental data for validation of the self-wastage analytical method. (author)

  8. Advancement of compressible multiphase flows and sodium-water reaction analysis program SERAPHIM. Validation of a numerical method for the simulation of highly underexpanded jets

    International Nuclear Information System (INIS)

    Uchibori, Akihiro; Ohshima, Hiroyuki; Watanabe, Akira

    2010-01-01

    SERAPHIM is a computer program for the simulation of the compressible multiphase flow involving the sodium-water chemical reaction under a tube failure accident in a steam generator of sodium cooled fast reactors. In this study, the numerical analysis of the highly underexpanded air jets into the air or into the water was performed as a part of validation of the SERAPHIM program. The multi-fluid model, the second-order TVD scheme and the HSMAC method considering a compressibility were used in this analysis. Combining these numerical methods makes it possible to calculate the multiphase flow including supersonic gaseous jets. In the case of the air jet into the air, the calculated pressure, the shape of the jet and the location of a Mach disk agreed with the existing experimental results. The effect of the difference scheme and the mesh resolution on the prediction accuracy was clarified through these analyses. The behavior of the air jet into the water was also reproduced successfully by the proposed numerical method. (author)

  9. Analysis of self-wastage phenomena of micro leak caused by sodium-water reaction in sodium-cooled fast breeder reactor through simulant experiment

    International Nuclear Information System (INIS)

    Jang, Sunghyon; Takata, Takashi; Yamaguchi, Akira

    2014-01-01

    Self-wastage phenomena are an enlargement of a leak on the heat transfer tube caused by a corrosive sodium-water reaction (SWR) in a steam generator (SG) of sodium-cooled fast breeder reactor (SFR). If the steam generator operates for sometimes under this condition, the self-wastage phenomena start from the sodium side and advance through the tube thickness. The leak rate stays almost constant level until the wastage reaches the sodium side, however, when the thin diaphragm of the tube wall is removed, the leak rate sharply increase, and it may bring a secondary failure of the surrounding heat transfer tubes. The design and safety concern is a possibility of the secondary failure of nearby SG tubes that could cause undesirable development of the accidents. One needs to evaluate the increased resultant leak rate due to the self-wastage phenomenon. Therefore, a quantification of the diameter of enlarged leak is needed to estimate the resultant leak rate. For this purpose, a simulant self-wastage experiment was proposed to investigate the self-enlargement of the leak so that evaluate the mechanism of the Self-wastage. In the experiment, high concentrated hydrochloric acid (HCl) is injected to the reaction tank that is filled sodium hydroxide (NaOH) solution through a nozzle made by paraffin wax. The self-enlargement of the leak was evaluated by considering the melted nozzle due to the reaction heat released from the Neutralization reaction. Also, a numerical investigation has been carried out to evaluate the enlarged nozzle and validate the results of experimental methodology. Based on the experimental and computational results, it is found that despite initial leak rate, there is an upper limit in the enlarged nozzle. These results show a similar tendency with the experimental result of SWAT-4 experiment carried out by Power Reactor and Nuclear Fuel Development Corporation (PNC), Japan. Furthermore, the increased resultant leak rate is evaluated using the enlarged

  10. Passive vibro-acoustic detection of a sodium-water reaction in a steam generator of a sodium-cooled fast neutrons nuclear reactor by beam forming

    International Nuclear Information System (INIS)

    Moriot, Jeremy

    2013-01-01

    This thesis deals with a new method to detect a sodium-water reaction in a steam generator of a fast sodium-cooled nuclear reactor. More precisely, the objective is to detect a micro-leak of water (flow ≤ 1 g/s) in less than 10 seconds by measuring the external shell vibrations of the component. The strong background noise in operation makes impossible the use of a detection system based on a threshold overrun. A beam forming method applied to vibrations measured by a linear array of accelerometers is developed in this thesis to increase the signal-to-noise ratio and to detect and locate the leak in the steam generator. A numerical study is first realized. Two models are developed in order to simulate the signals measured by the accelerometers of the array. The performances of the beam forming are then studied in function of several parameters, such as the source location and frequency, the damping factor, the background noise considered. The first model consists in an infinite plate in contact with a heavy fluid, excited by an acoustic monopole located in this fluid. Analyzing the transverse displacements in the wavenumber domain is useful to establish a criterion to sample correctly the vibration field of the plate. A second model, more representative of the system is also proposed. In this model, an elastic infinite cylindrical shell, filled with a heavy fluid is considered. The finite dimensions in the radial and circumferential directions lead to a modal behavior of the system which impacts the beam forming. Finally, the method is tested on an experimental mock-up which consists in a cylindrical pipe made in stainless steel and filled with water connected to hydraulic circuit. The water flow speed can be controlled by varying the speed of the pump. The acoustic source is generated by a hydro-phone. The performances of the beam forming are studied for different water flow speeds and different amplitude and frequencies of the source. (author) [fr

  11. Evaluation of a sodium-water reaction event caused by steam generator tubes break in the prototype generation IV sodium-cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sang June; Ha, Kwi Seok; Chang, Won Pyo; Kang, Seok Hun; Lee, Kwi Lim; Choi, Chi Woong; Lee, Seung Won; Yoo, Jin; Jeong, Jae Ho; Jeong, Tae Kyeong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-08-15

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

  12. Market reaction to bank liquidity regulation

    OpenAIRE

    Bruno, Brunella; Onali, Enrico; Schaeck, Klaus

    2018-01-01

    We measure market reactions to announcements concerning liquidity regulation, a key innovation in the Basel framework. Our initial results show that liquidity regulation attracts negative abnormal returns. However, the price responses are less pronounced when coinciding announcements concerning capital regulation are backed out, suggesting that markets do not consider liquidity regulation to be binding. Bank- and country-specific characteristics also matter. Liquid balance sheets and high cha...

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

    Directory of Open Access Journals (Sweden)

    C. Bertrand

    2014-01-01

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

  14. Cooperation on impingement wastage experiment of Mod. 9Cr-1Mo steel using SWAT-1R sodium-water reaction test facility

    International Nuclear Information System (INIS)

    Beauchamp, F.; Allou, A.; Nishimura, M.; Umeda, R.

    2013-01-01

    Conclusion: • 6 experiments were carried out in the SWAT-1R facility of JAEA Oarai R&D Center to study the wastage resistance of the Mod. 9Cr-1Mo steel (T91) straight tubes. • These experiments were performed under the cooperation between CEA and JAEA. • The experiments were conducted successfully: - all the tubes were punctured by the reaction jet, - wastage and steam/water leak rates were obtained, - experimental results brought some new determining sets of wastage data on T91. • This fruitful cooperation has contributed to: - expanding the wastage database on T91, - upgrading wastage rates prediction from modelling, - the safety demonstration of future steam generators units

  15. Application of microwave irradiation to organic liquid phase reactions

    International Nuclear Information System (INIS)

    Huang Kun; Liu Hua; Ji Xuelin

    1994-01-01

    Microwave irradiation has been used in organic liquid phase reactions to significantly reduce the reaction time and improve the yield. The proposed mechanism, the development of techniques and reactions, such as Diels-Alder, ene, rearrangement reactions etc., are discussed

  16. Liquid-Crystalline Ionic Liquids as Ordered Reaction Media for the Diels-Alder Reaction.

    Science.gov (United States)

    Bruce, Duncan W; Gao, Yanan; Canongia Lopes, José Nuno; Shimizu, Karina; Slattery, John M

    2016-11-02

    Liquid-crystalline ionic liquids (LCILs) are ordered materials that have untapped potential to be used as reaction media for synthetic chemistry. This paper investigates the potential for the ordered structures of LCILs to influence the stereochemical outcome of the Diels-Alder reaction between cyclopentadiene and methyl acrylate. The ratio of endo- to exo-product from this reaction was monitored for a range of ionic liquids (ILs) and LCILs. Comparison of the endo:exo ratios in these reactions as a function of cation, anion and liquid crystallinity of the reaction media, allowed for the effects of liquid crystallinity to be distinguished from anion effects or cation alkyl chain length effects. These data strongly suggest that the proportion of exo-product increases as the reaction media is changed from an isotropic IL to a LCIL. A detailed molecular dynamics (MD) study suggests that this effect is related to different hydrogen bonding interactions between the reaction media and the exo- and endo-transition states in solvents with layered, smectic ordering compared to those that are isotropic. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Some problems of leaks in sodium-water steam generator

    International Nuclear Information System (INIS)

    Kozlov, F.A.; Sergeev, G.V.; Sednev, A.R.; Makarov, V.M.

    1976-01-01

    The paper contains data on wastage of steam generator structural materials and high-nickel alloys in the zone of water leakage into sodium as well as investigation results for self-enlargement of water leaks into sodium through defects in these materials. It is shown that the rate of material damage in the zone of sodium-water reaction and in the channel with water leaking-out decreases with increasing nickel content in steels and strongly depends on sodium temperature. The paper presents experimentally obtained dependences of leakage self-enlargement rates on sodium temperature and leakage size

  18. Recent developments in biocatalysis in multiphasic ionic liquid reaction systems.

    Science.gov (United States)

    Meyer, Lars-Erik; von Langermann, Jan; Kragl, Udo

    2018-06-01

    Ionic liquids are well known and frequently used 'designer solvents' for biocatalytic reactions. This review highlights recent achievements in the field of multiphasic ionic liquid-based reaction concepts. It covers classical biphasic systems including supported ionic liquid phases, thermo-regulated multi-component solvent systems (TMS) and polymerized ionic liquids. These powerful concepts combine unique reaction conditions with a high potential for future applications on a laboratory and industrial scale. The presence of a multiphasic system simplifies downstream processing due to the distribution of the catalyst and reactants in different phases.

  19. Liquid composition having ammonia borane and decomposing to form hydrogen and liquid reaction product

    Science.gov (United States)

    Davis, Benjamin L; Rekken, Brian D

    2014-04-01

    Liquid compositions of ammonia borane and a suitably chosen amine borane material were prepared and subjected to conditions suitable for their thermal decomposition in a closed system that resulted in hydrogen and a liquid reaction product.

  20. Ionic Liquids: An Environmentally Friendly Media for Nucleophilic Substitution Reactions

    International Nuclear Information System (INIS)

    Jorapur, Yogesh R.; Chi, Dae Yoon

    2006-01-01

    Ionic liquids are alternative reaction media of increasing interest and are regarded as an eco-friendly alternatives, of potential use in place of the volatile organic solvents typically used in current chemical processing methods. They are emerging as the smart and excellent solvents, which are made of positive and negative ions that they are liquids near room temperature. The nucleophilic substitution reaction is one of the important method for inserting functional groups into a carbon skeleton. Many nucleophilic substitution reactions have been found with enhanced reactivity and selectivity in ionic liquid. In this review, some recent interesting results of nucleophilic substitution reactions such as hydroxylations, ether cleavages, carbon-X (X = carbon, oxygen, nitrogen, fluorine) bond forming reactions, and ring opening of epoxides in ionic liquids are discussed

  1. Supported ionic liquids: versatile reaction and separation media

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Haumann, Marco

    2006-01-01

    The latest developments in supported ionic liquid phase (SILP) systems for catalysis and separation technology are surveyed. The SILP concept combines the advantages of homogeneous catalysis with heterogeneous process technology, and a variety of reactions have been studied where supported ionic ...... liquid catalysts proved to be more active and selective than common systems. In separation applications the use of supported ionic liquids can facilitate selective transport of substrates across membranes.......The latest developments in supported ionic liquid phase (SILP) systems for catalysis and separation technology are surveyed. The SILP concept combines the advantages of homogeneous catalysis with heterogeneous process technology, and a variety of reactions have been studied where supported ionic...

  2. Study of the moderating effect of salts on the sodium-water reaction on the cleaning of irradiated fuel assemblies from fast neutron reactors, using fluid sodium heat transfer

    International Nuclear Information System (INIS)

    Lacroix, Marie

    2014-01-01

    Within the framework of the development of generation IV reactors one of the research tracks is related to the development of fast neutron reactors using fluid sodium heat transfer. The CEA (French Alternative Energies and Atomic Energy Commission) plans to build a prototype of reactor of this type called 'ASTRID'. To address development requirements for this prototype, research is in progress on the reactor's availability and in particular on the reduction of the washing duration for residual sodium fuel assemblies during their discharge. In fact, because sodium is very reactive with water (presently the only available process), the washing is done, for example, by very gradual addition. A solution currently being studied at the CEA and which is the subject of this thesis report consists of the addition of an aqueous salts solutions to the washing water in order to slow down the kinetic reaction. This doctoral dissertation describes the various salts, which have been evaluated and aims to explain their action mode. (author) [fr

  3. The reactions of oxygen and hydrogen with liquid sodium

    International Nuclear Information System (INIS)

    Ullmann, H.

    1981-01-01

    Results so far available as to the reactions and chemical equilibrium of oxygen and hydrogen with liquid sodium have been analyzed critically. The enthalpy values of the reactions have been discussed and supplemented on the basis of corresponding BORN-HABER cycles. The concentration and temperature functions of the hydrogen equilibrium pressure were deduced from experimental results. In relation to the solubility data the solid phases coexisting with liquid sodium in the ternary system Na-O-H have been discussed. The reaction of oxygen with hydrogen in diluted solution in liquid sodium has been investigated in more detail. Interaction coefficients, and the temperature functions of the free energy of formation and the equilibrium constant have been determined. (orig.)

  4. Liquid Film Diffusion on Reaction Rate in Submerged Biofilters

    DEFF Research Database (Denmark)

    Christiansen, Pia; Hollesen, Line; Harremoës, Poul

    1995-01-01

    Experiments were carried out in order to investigate the influence of liquid film diffusion on reaction rate in a submerged biofilter with denitrification and in order to compare with a theoretical study of the mass transfer coefficient. The experiments were carried out with varied flow, identified...... by the empty bed velocity of inflow and recirculation, respectively 1.3, 2.8, 5.6 and 10.9 m/h. The filter material consisted of 3 mm biostyren spheres. The results indicate that the influence of liquid film diffusion on reaction rate can be ignored....

  5. From nuclear reactions to liquid-drop collisions

    International Nuclear Information System (INIS)

    Menchaca R, A.; Huidobro, F.; Martinez D, A.; Michaelian, K.; Perez, A.; Rodriguez, V.; Carjan, N.

    1997-01-01

    A review of the experimental and theoretical situation in coalescence and fragmentation studies of binary liquid-drop collisions is given, putting in perspective our own contributions, which include experiments with mercury and oil drops and the application of a nuclear reaction model, specifically modified by us for the macroscopic case. (Author)

  6. Influence of sodium water reaction on MONJU steam generator

    International Nuclear Information System (INIS)

    Takahashi, T.; Ohmori, Y.; Hoshi, Y.

    1984-01-01

    Despite the strenuous efforts improving the reliability of steam generators, it is required to ascertain the safe shutdown at Design Basis Leak and also to take the necessary actions to minimize the plant damage for more realistic small leaks. The process of Monju DBL selection and its supporting R and D works are included in this paper, together with the evaluation of system and critical components in direct connection with DBL. The detail plant shutdown procedures (including auxiliary system sequential action) at the time of water leaks are also explained. (author)

  7. Review of activities concerning sodium water reaction in LMFBR

    International Nuclear Information System (INIS)

    Rajput, A.K.

    1984-01-01

    This paper presents a review of activities concerning safety engineering programme for steam generators of FBT reactor in India. Leak rate and its effect and leak detection system are briefly discussed

  8. Maillard reaction products from chitosan-xylan ionic liquid solution.

    Science.gov (United States)

    Luo, Yuqiong; Ling, Yunzhi; Wang, Xiaoying; Han, Yang; Zeng, Xianjie; Sun, Runcang

    2013-10-15

    A facile method is reported to prepare Maillard reaction products (MRPs) from chitosan and xylan in co-solvent ionic liquid. UV absorbance and fluorescence changes were regarded as indicators of the occurrence of Maillard reaction. FT-IR, NMR, XRD and TG were used to investigate the structure of chitosan-xylan conjugate. The results revealed that when chitosan reacted with xylan in ionic liquid, the hydrogen bonds in chitosan were destroyed, the facts resulted in the formation of chitosan-xylan MRPs. Moreover, when the mass ratio of chitosan to xylan was 1:1, the Maillard reaction proceeded easily. In addition, relatively high antioxidant property was also noted for the chitosan-xylan conjugate with mass ratio 1:1. So the obtained chitosan-xylan MRP is a promising antioxidant agent for food industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Perspective: Chemical reactions in ionic liquids monitored through the gas (vacuum)/liquid interface.

    Science.gov (United States)

    Maier, F; Niedermaier, I; Steinrück, H-P

    2017-05-07

    This perspective analyzes the potential of X-ray photoelectron spectroscopy under ultrahigh vacuum (UHV) conditions to follow chemical reactions in ionic liquids in situ. Traditionally, only reactions occurring on solid surfaces were investigated by X-ray photoelectron spectroscopy (XPS) in situ. This was due to the high vapor pressures of common liquids or solvents, which are not compatible with the required UHV conditions. It was only recently realized that the situation is very different when studying reactions in Ionic Liquids (ILs), which have an inherently low vapor pressure, and first studies have been performed within the last years. Compared to classical spectroscopy techniques used to monitor chemical reactions, the advantage of XPS is that through the analysis of their core levels all relevant elements can be quantified and their chemical state can be analyzed under well-defined (ultraclean) conditions. In this perspective, we cover six very different reactions which occur in the IL, with the IL, or at an IL/support interface, demonstrating the outstanding potential of in situ XPS to gain insights into liquid phase reactions in the near-surface region.

  10. Pressure effects on electron reactions and mobility in nonpolar liquids

    International Nuclear Information System (INIS)

    Holroyd, R.A.; Nishikawa, Masaru

    2002-01-01

    High pressure studies have elucidated the mechanisms of both electron reactions and electron transport in nonpolar liquids and provided information about the partial molar volumes of ions and electrons. The very large volume changes associated with electron attachment reactions have been explained as due to electrostriction by the ions, calculated with a continuum model, but modified to include the formation of a glassy shell of solvent molecules around the ion. The mobilities of electrons in cases where the electron is trapped can now be understood by comparing the trap cavity volume with the volume of electrostriction of the solvent around the cavity. In cases where the electron is quasi-free the compressibility dependent potential fluctuations are shown to be important. The isothermal compressibility is concluded to be the single most important parameter determining the behavior of excess electrons in liquids

  11. Estimation of the Polymerization Rate of Liquid Propylene Using Adiabatic Reaction Calorimetry and Reaction Dilatometry

    NARCIS (Netherlands)

    Al-haj Ali, Mohammad; Betlem, Ben; Roffel, Brian; Weickert, Günter

    2007-01-01

    The use of pressure-drop and constant-pressure dilatometry for obtaining rate data for liquid propylene polymerization in filled batch reactors was examined. The first method uses reaction temperature and pressure as well as the compressibility of the reactor contents to calculate the polymerization

  12. Kinetics of liquid lithium reaction with oxygen-nitrogen mixtures

    International Nuclear Information System (INIS)

    Gil, T.K.; Kazimi, M.S.

    1986-01-01

    A series of experiments have been conducted in order to characterize the kinetics of lithium chemical reaction with a mixture of oxygen and nitrogen. Three mixed gas compositions were used; 80% N 2 and 20% O 2 , 90% N 2 and 10% O 2 , and 95% N 2 and 5% O 2 . The reaction rate was obtained as a function of lithium temperature and the oxygen fraction. Liquid lithium temperature varied from 400 to 1100 0 C. By varying the composition, the degree of inhibition of the lithium-nitrogen reaction rate due to the presence of oxygen was observed. The results indicate that the lithium-nitrogen reaction rate depended on both the fraction of oxygen present and lithium temperature. The lithium nitride layer formed from the reaction also had a significant inhibition effect on the lithium-nitrogen reaction rate while the lithium-oxygen reaction rate was not as greatly hindered. LITFIRE, a computer code which simulates temperature and pressure history in a containment building following lithium spills, was modified by including (1) an improved model for the lithium-nitrogen reaction rate and (2) a model for the lithium-CO 2 reaction. LITFIRE was used to simulate HEDL's LC-2 and LA-5 experiments, and the predicted temperatures and pressures were in a reasonable agreement. Furthermore, LITFIRE was applied to a prototypical fusion reactor containment in order to simulate the consequences of a lithium spill accident. The result indicated that if nitrogen was used as containment building gas during the accident, the consequences of the accident would be less severe than those with air. The pressure rise in the building was found to be reduced by 50% and the maximum temperature of the combustion zone was limited to 900 0 C instead of 1200 0 C in the case of air

  13. Acidic ionic liquids for n-alkane isomerization in a liquid-liquid or slurry-phase reaction mode

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, C.; Hager, V.; Geburtig, D.; Kohr, C.; Wasserscheid, P. [Erlangen-Nuernberg Univ. (Germany). Lehrstuhl fuer Chemische Reaktionstechnik; Haumann, M. [Chemical Reaction Engineering, FAU Busan Campus, Korea (Korea, Republic of)

    2011-07-01

    Highly acidic ionic liquid (IL) catalysts offer the opportunity to convert n-alkanes at very low reaction temperatures. The results of IL catalyzed isomerization and cracking reactions of pure n-octane are presented. Influence of IL composition, [C{sub 4}C{sub 1}Im]Cl / AlCl{sub 3} / H{sub 2}SO{sub 4} and [C{sub 4}C{sub 1}Im]Cl / AlCl{sub 3} / 1-chlorooctane, on catalyst activity and selectivities to branched alkanes was investigated. Acidic chloroaluminate IL catalysts form liquid-liquid biphasic systems with unpolar organic product mixtures. Thus, recycling of the acidic IL is enabled by simple phase separation in the liquid-liquid biphasic reaction mode or the IL can be immobilized on an inorganic support with a large specific surface area. These supported ionic liquid phase (SILP) catalysts offer the advantage to get a macroscopically heterogeneous system while still preserving all benefits of the homogeneous catalyst which can be used for the slurry-phase n-alkane isomerization. The interaction of the solid support and acidic IL influences strongly the catalytic activity. (orig.)

  14. Reactions of Lignin Model Compounds in Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, John E.; Binder, Joseph B.; Gray, Michel J.; White, James F.; Zhang, Z. Conrad

    2009-09-15

    Lignin, a readily available form of biomass, awaits novel chemistry for converting it to valuable aromatic chemicals. Recent work has demonstrated that ionic liquids are excellent solvents for processing woody biomass and lignin. Seeking to exploit ionic liquids as media for depolymerization of lignin, we investigated reactions of lignin model compounds in these solvents. Using Brønsted acid catalysts in 1-ethyl-3-methylimidazolium triflate at moderate temperatures, we obtained up to 11.6% yield of the dealkylation product guaiacol from the model compound eugenol and cleaved phenethyl phenyl ether, a model for lignin ethers. Despite these successes, acid catalysis failed in dealkylation of the unsaturated model compound 4-ethylguaiacol and did not produce monomeric products from organosolv lignin, demonstrating that further work is required to understand the complex chemistry of lignin depolymerization.

  15. Reaction of water vapor with a clean liquid uranium surface

    International Nuclear Information System (INIS)

    Siekhaus, W.

    1985-01-01

    To study the reaction of water vapor with uranium, we have exposed clean liquid uranium surfaces to H 2 O under UHV conditions. We have measured the surface concentration of oxygen as a function of exposure, and determined the maximum attainable surface oxygen concentration X 0 /sup s/ as a function of temperature. We have used these measurements to estimate, close to the melting point, the solubility of oxygen (X 0 /sup b/, -4 ) and its surface segregation coefficient β/sup s/(> 10 3 ). 8 refs., 5 figs., 1 tab

  16. Ionic liquids, tuneable solvents for intensifying reactions and separations

    NARCIS (Netherlands)

    Meindersma, G.W.; Kuipers, N.J.M.; Haan, de A.B.

    2007-01-01

    An Ionic Liquid (IL), or a Room Temperature Ionic Liquid (RTIL), is commonly defined as a liquid entirely composed of ions, which is a fluid below 100 °C. Due to the fact that an ionic liquid is a salt, it has a negligible vapour pressure. Therefore, ionic liquids are not volatile at ambient process

  17. The removal of dinitrochlorobenzene from industrial residuals by liquid-liquid extraction with chemical reaction

    Directory of Open Access Journals (Sweden)

    G. C. M. Ferreira

    2007-09-01

    Full Text Available Nitrochlorobenzenes (NCBs are very important in the chemical industry since they have been used as raw material for the manufacture of crop protection products, as active ingredients in the pharmaceutical industry, as pigments and as antioxidants as well as for other uses. In industrial processes, NCBs are produced by monochlorobenzene (MCB nitration reactions and one of the main residuals formed is dinitrochlorobenzene (DNCB, which is mainly composed of the isomer 2,4DNCB. This subproduct, although of commercial interest when in its pure state, is generally incinerated due to the high costs of recovery treatment and purification. The objective of this study is to present an alternative to the treatment of industrial residuals containing DNCB. The technique consists of converting DNCB into sodium dinitrophenolate, which is very soluble in water and is also easy to reuse. For this purpose, liquid-liquid extraction with chemical reaction (alkaline hydrolysis with a rotating disc contactor (RDC is used. Experimental data on MCB nitration reactions as well as alkaline hydrolysis using a rotating disc contactor are presented.

  18. Restrictive liquid-phase diffusion and reaction in bidispersed catalysts

    International Nuclear Information System (INIS)

    Lee, S.Y.; Seader, J.D.; Tsai, C.H.; Massoth, F.E.

    1991-01-01

    In this paper, the effect of bidispersed pore-size distribution on liquid-phase diffusion and reaction in NiMo/Al 2 O 3 catalysts is investigated by applying two bidispersed-pore-structure models, the random-pore model and a globular-structure model, to extensive experimental data, which were obtained from sorptive diffusion measurements at ambient conditions and catalytic reaction rate measurements on nitrogen-containing compounds. Transport of the molecules in the catalysts was found to be controlled by micropore diffusion, in accordance with the random-pore model, rather than macropore diffusion as predicted by the globular-structure model. A qualitative criterion for micropore-diffusion control is proposed: relatively small macroporosity and high catalyst pellet density. Since most hydrotreating catalysts have high density, diffusion in these types of catalysts may be controlled by micropore diffusion. Accordingly, it is believed in this case that increasing the size of micropores may be more effective to reduce intraparticle diffusion resistance than incorporating macropores alone

  19. Reaction of hydroborate anions with liquid hydrogen fluoride

    International Nuclear Information System (INIS)

    Volkov, V.V.; Myakishev, K.G.

    1978-01-01

    The reaction of anhydrous liquid HF with salts of the decahydro-closodecarborate (2) ion B 10 H 10 2- at room temperature or a decreased temperature leads to the formation of complex mixtures of high-molecular boranes with yields of 88 to 92 %. This solid, yellow, nonvolatile product contains traces of B 10 H 14 and B 18 H 22 . The average molecular masses of the borane mixtures obtained are in the range of 438 - 992. The complex composition of the mixtures was confirmed by thin-layer chromatography on silica gel. The IR and NMR spectra of the products are presented. The possible mechanism of the reaction between HF and B 10 H 10 2- with the formation of higher boron hydrides is discussed. Salts of B 12 H 10 2- and B 10 Cl 10 2- do not react with HF; KBF 4 and CsB 9 H 14 are decomposed by HF with the formation of MBF 4

  20. Ionic debye screening in dense liquid plasmas observed for Li+p, d reactions with liquid Li target

    International Nuclear Information System (INIS)

    Kasagi, J.; Yonemura, H.; Toriyabe, Y.; Nakagawa, A.; Sugawara, T.; Wang Tieshan

    2009-01-01

    Thick target yields of α particles emitted in the 6 Li(d,α) 4 He and 7 Li(p,α) 4 He reactions were measured for Li target in the solid and liquid phase. Observed reaction rates for the liquid Li are always larger than those for the solid. This suggests that the stopping power of hydrogen ion in the liquid Li metal might be smaller than in the solid. Using the empirically obtained stopping power for the liquid Li, we have deduced the screening potentials of the Li+p and Li+d reactions in both phases. The deduced screening potential for the liquid Li is about 500 eV larger than for the solid. This difference is attributed to the effect of liquefied Li + ions. It is concluded that the ionic screening is much stronger than the electronic screening in a low-temperature dense plasmas. (authors)

  1. Ionic Debye Screening in Dense Liquid Plasmas Observed for Li+p,d Reactions with Liquid Li Target

    Institute of Scientific and Technical Information of China (English)

    J.Kasagi; H.Yonemura; Y.Toriyabe; A.Nakagawa; T.Sugawara; WANG Tie-shan

    2009-01-01

    Thick target yields of a particles emitted in the ~6Li(d,a)~4 He and ~7Li(p,a)~4 He reactions were measured for Li target in the solid and liquid phase.Observed reaction rates for the liquid Li are always larger than those for the solid.This suggests that the stopping power of hydrogen ion in the liquid Li metal might be smaller than in the solid.Using the empirically obtained stopping power for the liquid Li,we have deduced the screening potentials of the Li+p and Li+d reactions in both phases.The deduced screening potential for the liquid Li is about 500 eV larger than for the solid.This difference is attributed to the effect of liquefied Li~+ ions.It is concluded that the ionic screening is much stronger than the electronic screening in a low-temperature dense plasmas.

  2. Physical Chemistry of Reaction Dynamics in Ionic Liquid

    Energy Technology Data Exchange (ETDEWEB)

    Maroncelli, Mark [Pennsylvania State Univ., University Park, PA (United States)

    2016-10-02

    Work completed over the past year mainly involves finishing studies related to solvation dynamics in ionic liquids, amplifying and extending our initial PFG-NMR work on solute diffusion, and learning how to probe rotational dynamics in ionic liquids.

  3. Reactions of carbon acids and 1,3-dipoles in the presence of ionic liquids

    International Nuclear Information System (INIS)

    Zlotin, Sergei G; Makhova, Nina N

    2010-01-01

    The review is devoted to the use of ionic liquids as solvents, immobilized organocatalysts and reagents in reactions involving carbon acids and 1,3-dipoles, which are widely used to prepare practically valuable organic compounds of various classes. The characteristic features of processes in the presence of ionic liquids, the effects of the structure of cations and anions on the regio-, stereo- and enantioselectivities of reactions and methods of recovery of ionic liquids are considered.

  4. Sodium-water clusters and their role in radiation chemistry

    International Nuclear Information System (INIS)

    Dhar, S.; Kestner, N.R.

    1988-01-01

    Studies of sodium-water clusters are presented which could serve as models for the recently suggested intermediate species in the radiation chemistry of water. The ionization potentials and the lower excited states of sodium with n-water molecules are calculated by ab initio quantum chemistry methods. The ionization potential calculated at the SCF level for the water monomer is 4.10 eV, which becomes 4.34 at the MP2 correlation level. The experimental value is 4.379 ± 0.002 eV. Structural data is presented for the lower members of the sodium with n-water clusters. In addition the Hartree-Fock calculations indicate that there should be some strong charge transfer to solvent transitions at higher energies. (author)

  5. SISGR: Physical Chemistry of Reaction Dynamics in Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Blank, David [Univ. of Minnesota, Minneapolis, MN (United States)

    2017-10-30

    Room temperature ionic liquids (RTILs) are liquids made up of atomic and molecular ions. This is in contrast with more common liquids, such as water, that are made up of neutral molecules. The additional charges on the atoms and molecules can alter the properties of these liquids, for example they tend to have a very high vapor pressure and the ability to shield charge in electronic devices. For these and other reasons RTILs have recently been deployed in a number of applications that involve production of free electrons in the liquid, such as batteries, capacitors, nuclear power plants, and solar cells. Electrons tend to be very reactive, and understanding their behaviour in these liquids is important for the future design of ionic liquids to be employed in these environments. This study investigated the behavior of electrons generated in RTILs by pulses of ultraviolet light, including how long they survive, and how reactive they are with the both the surrounding liquid and impurities in the liquid. The ionic liquid studied was one of the most commonly used, called N-alkyl-N-methyl-pyrrolidinium bistriflimide. What the study revealed was that the majority of the electrons initially created, about 96%, had a very short lifetime of less than one picosecond (10-12 second) due to a process called geminate recombination. The study also demonstrated that the electrons are very reactive at the moment they are detached from the molecules in the liquid by light, but that they relax very quickly and lose almost all of their reactivity in much less than one picosecond. The short lifetime and rapid loss of reactivity both serve as important mechanisms that protect the liquid from radiolytic damage.

  6. Modeling and analysis of liquid deuterium-water reactions

    International Nuclear Information System (INIS)

    Taleyarkhan, R.P.

    1995-01-01

    This Presentation highlights the following: Overview of LD 2 -water reactions their connections to research reactors with cold sources; some key features and ingredients of vapor explosions in general; Examination of results of 1970 experiment at Grenoble Nuclear Research Center; Thermodynamic evaluations of energetics of explosive LD 2 -D 2 O reactions. This presentation concentrates only on the technical aspects of LD 2 /LH 2 - water reactions; it is not intended to draw/imply safety-related conclusions for research reactors

  7. Hydrogenation Reactions in Ionic Liquids. The Efficient Reduction of ...

    African Journals Online (AJOL)

    NJD

    2008-12-09

    Dec 9, 2008 ... Volatile organic solvents such as ethanol, methanol and THF are often used for the ... remained consistently high and only declined markedly on the fifth cycle. ... transferral of the viscous liquid from the hydrogenation reactor.

  8. Synthesis of Guanidines via Reaction of Amines with Carbodiimides in the Presence of Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Foad Shaghayeghi Toosi

    2016-01-01

    Full Text Available Different ionic liquids (ILs were synthesized and evaluated for the preparation of substituted guanidines from the reaction of amines and carbodiimides. 1-methylimidazolium tetrafluoroborate [HMIm]BF4 was found to be the best ionic liquid for this reaction. This IL acted as a promoter for the addition of primary and secondary amines to carbodiimides. By this efficient approach, various guanidines were prepared in excellent yields.

  9. Stability of Transition-metal Carbides in Liquid Phase Reactions Relevant for Biomass-Based Conversion

    NARCIS (Netherlands)

    Souza Macêdo, L.; Stellwagen, D.R.; Teixeira da Silva, V.; Bitter, J.H.

    2015-01-01

    Transition-metal carbides have been employed for biobased conversions aiming to replace the rare noble metals. However, when reactions are in liquid phase, many authors have observed catalyst deactivation. The main routes of deactivation in liquid phase biobased conversions are coke deposition,

  10. Novel routes to metal nanoparticles : electrodeposition and reactions at liquid-liquid interfaces

    OpenAIRE

    Johans, Christoffer

    2003-01-01

    This thesis considers the nucleation and growth, synthesis, and catalytic application of metallic nanoparticles at liquid|liquid interfaces. It comprises five publications, a previously unpublished synthesis of polymer coated palladium nanoparticles, and an introduction to the relevant literature. Three publications are concerned with electrodeposition of metal nanoparticles at liquid|liquid interfaces. One publication and the results presented here consider the synthesis of silver and pallad...

  11. Process for carrying out a chemical reaction with ionic liquid and carbon dioxide under pressure

    NARCIS (Netherlands)

    Kroon, M.C.; Shariati, A.; Florusse, L.J.; Peters, C.J.; Van Spronsen, J.; Witkamp, G.J.; Sheldon, R.A.; Gutkowski, K.I.

    2006-01-01

    The invention is directed to a process for carrying out a chemical reaction in an ionic liquid as solvent and CO2 as cosolvent, in which process reactants are reacted in a homogeneous phase at selected pressure and temperature to generate a reaction product at least containing an end-product of the

  12. Aza-crown ether complex cation ionic liquids: preparation and applications in organic reactions.

    Science.gov (United States)

    Song, Yingying; Cheng, Chen; Jing, Huanwang

    2014-09-26

    Aza-crown ether complex cation ionic liquids (aCECILs) were devised, fabricated, and characterized by using NMR spectroscopy, MS, thermogravimetric differential thermal analysis (TG-DTA), elemental analysis and physical properties. These new and room-temperature ILs were utilized as catalysts in various organic reactions, such as the cycloaddition reaction of CO2 to epoxides, esterification of acetic acid and alcohols, the condensation reaction of aniline and propylene carbonate, and Friedel-Crafts alkylation of indole with aldehydes were investigated carefully. In these reactions, the ionic liquid exhibited cooperative catalytic activity between the anion and cation. In addition, the aza-[18-C-6HK][HSO4]2 was the best acidic catalyst in the reactions of esterification and Friedel-Crafts alkylation under mild reaction conditions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Mass transfer rate through liquid membranes: interfacial chemical reactions and diffusion as simultaneous permeability controlling factors

    International Nuclear Information System (INIS)

    Danesi, P.R.; Horwitz, E.P.; Vandegrift, G.F.; Chiarizia, R.

    1981-01-01

    Equations describing the permeability of a liquid membrane to metal cations have been derived taking into account aqueous diffusion, membrane diffusion, and interfacial chemical reactions as simultaneous permeability controlling factors. Diffusion and chemical reactions have been coupled by a simple model analogous to the one previously described by us to represent liquid-liquid extraction kinetics. The derived equations, which make use of experimentally determined interfacial reaction mechanisms, qualitatively fit unexplained literature data regarding Cu 2+ transfer through liquid membranes. Their use to predict and optimize membrane permeability in practical separation processes by setting the appropriate concentration of the membrane carrier [LIX 64 (General Mills), a commercial β-hydroxy-oxime] and the pH of the aqueous copper feed solution is briefly discussed. 4 figures

  14. Ionic Liquids as Solvents for Rhodium and Platinum Catalysts Used in Hydrosilylation Reaction

    Directory of Open Access Journals (Sweden)

    Witold Zielinski

    2016-08-01

    Full Text Available A group of imidazolium and pyridinium based ionic liquids has been synthetized, and their ability to dissolve and activate the catalysts used in hydrosilylation reaction of 1-octane and 1,1,1,3,5,5,5-heptamethyltrisiloxane was investigated. An organometallic catalyst as well as inorganic complexes of platinum and rhodium dissolved in ionic liquids were used, forming liquid solutions not miscible with the substrates or with the products of the reaction. The results show that application of such a simple biphasic catalytic system enables reuse of ionic liquid phase with catalysts in multiple reaction cycles reducing the costs and decreasing the amount of catalyst needed per mole of product.

  15. Quantifying Chemical and Electrochemical Reactions in Liquids by in situ Electron Microscopy

    DEFF Research Database (Denmark)

    Canepa, Silvia

    and developing a robust imaging analysis method for quantitatively understand chemical and electrochemical process during in situ liquid electron microscopy. By using two custom-made liquid cells (an electrochemical scanning electron microscopy (EC-SEM) platform and Liquid Flow S/TEM holder) beam...... of electrochemical deposition of copper (Cu) by electrochemical liquid scanning electron microscopy (EC-SEM) was done in order to direct observe the formation of dendritic structures. Finally the shape evolution from solid to hollow structures through galvanic replacement reactions were observed for different silver...

  16. Liquid-drop effects in sub-barrier fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, C E; Barbosa, V C; Canto, L F; Donangelo, R

    1988-01-28

    We introduce an operational measure for the enhancement of the fusion cross section at sub-barrier energies in terms of an asymptotic energy shift ..delta..E. It is shown that ..delta..E has a continuously growing trend with the size of the system. This trend is explained in terms of neck formation using the liquid-drop model. Deviations from this trend are attributed to strong coupling to specific channels.

  17. Hydrogen meter for service in liquid sodium

    International Nuclear Information System (INIS)

    McCown, J.J.

    1983-11-01

    This standard establishes the requirements for the design, materials, fabrication, quality assurance, examination, and acceptance testing of a hydrogen meter and auxiliary equipment for use in radioactive or nonradioactive liquid sodium service. The meter shall provide a continuous and accurate indication of the hydrogen impurity concentration over the range 0.03 to 10 ppM hydrogen in sodium at temperatures between 800 and 1000 0 F (427 and 538 0 C). The meter may also be used to rapidly monitor changes in hydrogen concentration, over the same concentration range, and, therefore can be used as a sensor for sodium-water reactions in LMFBR steam generators

  18. Physical Chemistry of Reaction Dynamics in Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Margulis, Claudio Javier [Univ. of Iowa, Iowa City, IA (United States)

    2016-10-31

    The Margulis group BES funded research at the University of Iowa is part of a broader collaborative effort that includes the groups of Blank (U. Minnesota), Castner (Rutgers U.), Maroncelli (Penn. State U.) and Wishart (BNL). The goal of this group of PIs is to better understand from an experimental and a theoretical perspective different aspects of photo-initiated electron transfer processes in a set of different room-temperature ionic-liquid systems. The Margulis contribution is theoretical and computational. Details are presented in the attached documentation.

  19. In Situ Environmental TEM in Imaging Gas and Liquid Phase Chemical Reactions for Materials Research.

    Science.gov (United States)

    Wu, Jianbo; Shan, Hao; Chen, Wenlong; Gu, Xin; Tao, Peng; Song, Chengyi; Shang, Wen; Deng, Tao

    2016-11-01

    Gas and liquid phase chemical reactions cover a broad range of research areas in materials science and engineering, including the synthesis of nanomaterials and application of nanomaterials, for example, in the areas of sensing, energy storage and conversion, catalysis, and bio-related applications. Environmental transmission electron microscopy (ETEM) provides a unique opportunity for monitoring gas and liquid phase reactions because it enables the observation of those reactions at the ultra-high spatial resolution, which is not achievable through other techniques. Here, the fundamental science and technology developments of gas and liquid phase TEM that facilitate the mechanistic study of the gas and liquid phase chemical reactions are discussed. Combined with other characterization tools integrated in TEM, unprecedented material behaviors and reaction mechanisms are observed through the use of the in situ gas and liquid phase TEM. These observations and also the recent applications in this emerging area are described. The current challenges in the imaging process are also discussed, including the imaging speed, imaging resolution, and data management. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Microchemical Plant in a Liquid Droplet: Plasmonic Liquid Marble for Sequential Reactions and Attomole Detection of Toxin at Microliter Scale.

    Science.gov (United States)

    Han, Xuemei; Koh, Charlynn Sher Lin; Lee, Hiang Kwee; Chew, Wee Shern; Ling, Xing Yi

    2017-11-15

    Miniaturizing the continuous multistep operations of a factory into a microchemical plant offers a safe and cost-effective approach to promote high-throughput screening in drug development and enforcement of industrial/environmental safety. While particle-assembled microdroplets in the form of liquid marble are ideal as microchemical plant, these platforms are mainly restricted to single-step reactions and limited to ex situ reaction monitoring. Herein, we utilize plasmonic liquid marble (PLM), formed by encapsulating liquid droplet with Ag nanocubes, to address these issues and demonstrate it as an ideal microchemical plant to conduct reaction-and-detection sequences on-demand in a nondisruptive manner. Utilizing a two-step azo-dye formation as our model reaction, our microchemical plant allows rapid and efficient diazotization of nitroaniline to form diazonium nitrobenzene, followed by the azo coupling of this intermediate with target aromatic compound to yield azo-dye. These molecular events are tracked in situ via SERS measurement through the plasmonic shell and further verified with in silico investigation. Furthermore, we apply our microchemical plant for ultrasensitive SERS detection and quantification of bisphenol A (BPA) with detection limit down to 10 amol, which is 50 000-fold lower than the BPA safety limit. Together with the protections offered by plasmonic shell against external environments, these collective advantages empower PLM as a multifunctional microchemical plant to facilitate small-volume testing and optimization of processes relevant in industrial and research contexts.

  1. Pico-second laser spectroscopy and reaction dynamics in liquids

    International Nuclear Information System (INIS)

    Mialocq, Jean-Claude

    1984-01-01

    The dynamic relaxation of excited singlet states of molecules and ions in liquid solution is investigated using picosecond laser spectroscopy. The more efficient process for the deactivation of the first excited singlet state of pinacyanol is internal conversion S 1 → S 0 between iso-energetic states. At low viscosity, the rate constant is inversely proportional to the macroscopic viscosity and depends on the relaxation of the angle between the quinoline end groups around the polymethinic chain. Electron photodetachment by 265 nm excitation of the ferrocyanide and phenolate anions and photoionisation of neutral molecules, phenol, indole and tryptophan in polar solvents give rise to the solvated electron formation. The mono-or bi-photonic nature of the ejection process and the solvent relaxation around the excess electron are analyzed. (author) [fr

  2. SN2 fluorination reactions in ionic liquids: a mechanistic study towards solvent engineering.

    Science.gov (United States)

    Oh, Young-Ho; Jang, Hyeong Bin; Im, Suk; Song, Myoung Jong; Kim, So-Yeon; Park, Sung-Woo; Chi, Dae Yoon; Song, Choong Eui; Lee, Sungyul

    2011-01-21

    In the catalysis of S(N)2 fluorination reactions, the ionic liquid anion plays a key role as a Lewis base by binding to the counterion Cs(+) and thereby reducing the retarding Coulombic influence of Cs(+) on the nucleophile F(-). The reaction rates also depend critically on the structures of ionic liquid cation, for example, n-butyl imidazolium gives no S(N)2 products, whereas n-butylmethyl imidazolium works well. The origin of the observed phenomenal synergetic effects by the ionic liquid [mim-(t)OH][OMs], in which t-butanol is bonded covalently to the cation [mim], is that the t-butanol moiety binds to the leaving group of the substrate, moderating the retarding interactions between the acidic hydrogen and F(-). This work is a significant step toward designing and engineering solvents for promoting specific chemical reactions.

  3. An Unexpected Reaction between 5-Hydroxymethylfurfural and Imidazolium-Based Ionic Liquids at High Temperatures

    Directory of Open Access Journals (Sweden)

    Zongbao K. Zhao

    2011-10-01

    Full Text Available A new compound was detected during the production of 5-hydroxymethylfurfural (HMF from glucose and cellulose in the ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl at high temperatures. Further experiments found that it was derived from the reaction of HMF with [Bmim]Cl. The structure of new compound was established as 1-butyl-2-(5’-methyl-2’-furoylimidazole (BMI based on nuclear magnetic resonance and mass spectrometry analysis, and a possible mechanism for its formation was proposed. Reactions of HMF with other imidazolium-based ionic liquids were performed to check the formation of BMI. Our results provided new insights in terms of side reactions between HMF and imidazolium-based ionic liquids, which should be valuable for designing better processes for the production of furans using biomass and related materials.

  4. Thin liquid films with time-dependent chemical reactions sheared by an ambient gas flow

    Science.gov (United States)

    Bender, Achim; Stephan, Peter; Gambaryan-Roisman, Tatiana

    2017-08-01

    Chemical reactions in thin liquid films are found in many industrial applications, e.g., in combustion chambers of internal combustion engines where a fuel film can develop on pistons or cylinder walls. The reactions within the film and the turbulent outer gas flow influence film stability and lead to film breakup, which in turn can lead to deposit formation. In this work we examine the evolution and stability of a thin liquid film in the presence of a first-order chemical reaction and under the influence of a turbulent gas flow. Long-wave theory with a double perturbation analysis is used to reduce the complexity of the problem and obtain an evolution equation for the film thickness. The chemical reaction is assumed to be slow compared to film evolution and the amount of reactant in the film is limited, which means that the reaction rate decreases with time as the reactant is consumed. A linear stability analysis is performed to identify the influence of reaction parameters, material properties, and environmental conditions on the film stability limits. Results indicate that exothermic reactions have a stabilizing effect whereas endothermic reactions destabilize the film and can lead to rupture. It is shown that an initially unstable film can become stable with time as the reaction rate decreases. The shearing of the film by the external gas flow leads to the appearance of traveling waves. The shear stress magnitude has a nonmonotonic influence on film stability.

  5. Recoil halogen reactions in liquid and frozen aqueous solutions of biomolecules

    International Nuclear Information System (INIS)

    Arsenault, L.J.; Blotcky, A.J.; Firouzbakht, M.L.; Rack, E.P.; Nebraska Univ., Omaha

    1982-01-01

    Reactions of recoil 38 Cl, 80 Br and 128 I have been studied in crystalline systems of 5-halouracil, 5-halo-2'-deoxyuridine and 5-halouridine as well as liquid and frozen aqueous solutions of these halogenated biomolecules. In all systems expect crystalline 5-iuodouracil the major product was the radio-labelled halide ion. There was no evidence for other halogen inorganic species. The major labelled organic product was the parent molecule. A recoil atom tracer technique was developed to acquire site information of the biomolecule solutes in the liquid and frozen aqueous systems. For all liquid and frozen aqueous systems, the halogenated biomolecules tended to aggregate. For liquid systems, the tendency for aggregation diminished as the solute concentration approached zero, where the probable state of the solute approached a monomolecular dispersion. Unlike the liquid state, the frozen ice lattice demonstated a ''caging effect'' for the solute aggregates which resulted in constant product yields over the whole concentration range. (orig.)

  6. A flow reactor setup for photochemistry of biphasic gas/liquid reactions

    Directory of Open Access Journals (Sweden)

    Josef Schachtner

    2016-08-01

    Full Text Available A home-built microreactor system for light-mediated biphasic gas/liquid reactions was assembled from simple commercial components. This paper describes in full detail the nature and function of the required building elements, the assembly of parts, and the tuning and interdependencies of the most important reactor and reaction parameters. Unlike many commercial thin-film and microchannel reactors, the described set-up operates residence times of up to 30 min which cover the typical rates of many organic reactions. The tubular microreactor was successfully applied to the photooxygenation of hydrocarbons (Schenck ene reaction. Major emphasis was laid on the realization of a constant and highly reproducible gas/liquid slug flow and the effective illumination by an appropriate light source. The optimized set of conditions enabled the shortening of reaction times by more than 99% with equal chemoselectivities. The modular home-made flow reactor can serve as a prototype model for the continuous operation of various other reactions at light/liquid/gas interfaces in student, research, and industrial laboratories.

  7. ALDOL- AND MANNICH-TYPE REACTIONS VIA IN SITU OLEFIN MIGRATION IN IONIC LIQUID

    Science.gov (United States)

    An aldol-type and a Mannich-type reaction via the cross-coupling of aldehydes and imines with allylic alcohols catalyzed by RuCl2(PPh3)3 was developed with ionic liquid as the solvent. The solvent/catalyst system could be reused for at least five times with no loss of reactiv...

  8. Supported liquid phase catalyst coating in micro flow Mizoroki-Heck reaction

    NARCIS (Netherlands)

    Stouten, S.C.; Noël, T.; Wang, Q.; Hessel, V.

    2015-01-01

    A Supported Liquid Phase Catalyst (SLPC) coating was successfully applied for the Mizoroki–Heck reaction in micro flow. Foremost, extended on stream operation was enabled and the on stream performance stability was verified. Stable catalytic activity was achieved during two consecutive runs totaling

  9. Reactions of oxygen and hydrogen with liquid sodium - a critical survey

    International Nuclear Information System (INIS)

    Ullmann, H.

    1982-01-01

    The fundamentals of solvation chemistry are presented with appropriate components formulated. Methods of investigation and kinetics of the reactions are described. The hydrogen equilibrium pressure and saturation solubilities are described. The chemical equilibrium between O and H in solution is presented with detailed tabulation of the saturation solutions of oxygen, hydrogen and hydroxide in liquid sodium. Agreements and differences with the literature are presented

  10. The reaction between barium and nitrogen in liquid sodium: resistivity studies

    International Nuclear Information System (INIS)

    Addison, C.C.; Creffield, G.K.; Hubberstey, P.; Pulham, R.J.

    1976-01-01

    The reaction of nitrogen with solutions of barium (between 0.34 and 6.89 mol % Ba) in liquid sodium at 573 K has been followed by changes in the electrical resistivity of the liquid. The capillary method has been employed, continuous sampling during reaction being achieved by electromagnetic pumping. The initial solution of nitrogen in the metal, followed by precipitation of barium and nitrogen from sodium as the nitride Ba 2 N, are reflected in the resistivity changes. The solubility of nitrogen in the alloy is a linear function of the barium concentration: S(mol % N) = x/4 (0 <= x <= 6.89 mol % Ba). This and the decrease in resistivity which invariably occurs during the solution process, provides additional information on the nature of solvation of nitrogen in solution in the liquid metal. (author)

  11. Coloring Rate of Phenolphthalein by Reaction with Alkaline Solution Observed by Liquid-Droplet Collision.

    Science.gov (United States)

    Takano, Yuuka; Kikkawa, Shigenori; Suzuki, Tomoko; Kohno, Jun-ya

    2015-06-11

    Many important chemical reactions are induced by mixing two solutions. This paper presents a new way to measure rates of rapid chemical reactions induced by mixing two reactant solutions using a liquid-droplet collision. The coloring reaction of phenolphthalein (H2PP) by a reaction with NaOH is investigated kinetically. Liquid droplets of H2PP/ethanol and NaOH/H2O solutions are made to collide, which induces a reaction that transforms H2PP into a deprotonated form (PP(2-)). The concentration of PP(2-) is evaluated from the RGB values of pixels in the colored droplet images, and is measured as a function of the elapsed time from the collision. The obtained rate constant is (2.2 ± 0.7) × 10(3) M(-1) s(-1), which is the rate constant for the rate-determining step of the coloring reaction of H2PP. This method was shown to be applicable to determine rate constants of rapid chemical reactions between two solutions.

  12. Microjets and coated wheels: versatile tools for exploring collisions and reactions at gas-liquid interfaces.

    Science.gov (United States)

    Faust, Jennifer A; Nathanson, Gilbert M

    2016-07-07

    This tutorial review describes experimental aspects of two techniques for investigating collisions and reactions at the surfaces of liquids in vacuum. These gas-liquid scattering experiments provide insights into the dynamics of interfacial processes while minimizing interference from vapor-phase collisions. We begin with a historical survey and then compare attributes of the microjet and coated-wheel techniques, developed by Manfred Faubel and John Fenn, respectively, for studies of high- and low-vapor pressure liquids in vacuum. Our objective is to highlight the strengths and shortcomings of each technique and summarize lessons we have learned in using them for scattering and evaporation experiments. We conclude by describing recent microjet studies of energy transfer between O2 and liquid hydrocarbons, HCl dissociation in salty water, and super-Maxwellian helium evaporation.

  13. Gas-Liquid Separator design of SWRPRS in PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jung; Lee, Tae-ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    There is the Sodium-Water Reaction Pressure Relief System (SWRPRS) in PGSFR to prevent the Sodium- Water Reaction (SWR) due to the break of the steam generator tube. The piping to atmosphere includes several components such as gasliquid separator, backpressure rupture disk, and hydrogen igniter. Among these components, gas-liquid separator separates the liquid sodium which is included in gas SWR products not to react sodium and air. In this study, the size of gas-liquid separator, which is based on the hydrogen volume which is exhausted in the sodium dump tank, is determined. To determine the gas-liquid separator for the separation of gas and sodium particle dumped the SDT, Stairmand's model which has high performance among standard cyclone separator models is selected. The body diameter is determined, and other dimensions are determined due to the ratio about the body diameter. Shepherd and Lapple's model is selected as the pressure drop calculation model considering the conservation.

  14. The effect of varying the anion of an ionic liquid on the solvent effects on a nucleophilic aromatic substitution reaction.

    Science.gov (United States)

    Hawker, Rebecca R; Haines, Ronald S; Harper, Jason B

    2018-05-09

    A variety of ionic liquids, each containing the same cation but a different anion, were examined as solvents for a nucleophilic aromatic substitution reaction. Varying the proportion of ionic liquid was found to increase the rate constant as the mole fraction of ionic liquid increased demonstrating that the reaction outcome could be controlled through varying the ionic liquid. The solvent effects were correlated with the hydrogen bond accepting ability (β) of the ionic liquid anion allowing for qualitative prediction of the effect of changing this component of the solute. To determine the microscopic origins of the solvent effects, activation parameters were determined through temperature-dependent kinetic analyses and shown to be consistent with previous studies. With the knowledge of the microscopic interactions in solution, an ionic liquid was rationally chosen to maximise rate enhancement demonstrating that an ionic solvent can be selected to control reaction outcome for this reaction type.

  15. Simulating chemical reactions in ionic liquids using QM/MM methodology.

    Science.gov (United States)

    Acevedo, Orlando

    2014-12-18

    The use of ionic liquids as a reaction medium for chemical reactions has dramatically increased in recent years due in large part to the numerous reported advances in catalysis and organic synthesis. In some extreme cases, ionic liquids have been shown to induce mechanistic changes relative to conventional solvents. Despite the large interest in the solvents, a clear understanding of the molecular factors behind their chemical impact is largely unknown. This feature article reviews our efforts developing and applying mixed quantum and molecular mechanical (QM/MM) methodology to elucidate the microscopic details of how these solvents operate to enhance rates and alter mechanisms for industrially and academically important reactions, e.g., Diels-Alder, Kemp eliminations, nucleophilic aromatic substitutions, and β-eliminations. Explicit solvent representation provided the medium dependence of the activation barriers and atomic-level characterization of the solute-solvent interactions responsible for the experimentally observed "ionic liquid effects". Technical advances are also discussed, including a linear-scaling pairwise electrostatic interaction alternative to Ewald sums, an efficient polynomial fitting method for modeling proton transfers, and the development of a custom ionic liquid OPLS-AA force field.

  16. Liquid and Gas Phase Chemistry of Hypergolic Reactions between MMH and NTO or RFNA

    Science.gov (United States)

    Black, Ariel

    Hypergolic systems rely on fuel and oxidizer propellant combinations that spontaneously ignite upon contact. Monomethylhydrazine (MMH) fuel and nitrogen tetroxide (NTO) - based oxidizers embody the state of the art for hypergolic propellants, although the health and safety hazards associated with these propellants demand investigation into less-toxic, high performance alternatives. In order to replicate the combustion characteristics of these highly reactive propellants, a detailed understanding of the full reaction process is necessary. Current reaction mechanisms and hypergolic ignition models generally assume that gas-phase chemistry dominates the interaction since the liquid-phase reactions occur on the order of microseconds. However, condensed-phase reactions produce intermediates integral to gas-phase initiation and development. Additional insight into the physical and chemical processes that dictate this liquid-phase chemistry is therefore essential. Concurrently, further examination of the gas-phase reactions leading to and immediately following ignition is also needed. A method devoted to the determination of the liquid phase hypergolic reaction mechanism and kinematic rate parameters for MMH-NTO and MMH-red fuming nitric acid (RFNA) is presented in this study. MMH-RFNA reaction chemistry is better understood and documented in literature than MMH-NTO and is examined for comparison and validation. Drop on pool experiments at a range of temperatures were initially undertaken using MMH and RFNA and then modified to accommodate the high vapor pressure of NTO. Using a temperature and atmosphere controlled droplet contact chamber, the liquid phases of MMH-RFNA and MMH-NTO were studied by capturing impacts at frame rates from 100,000 to 500,000 fps. This footage allowed for the identification of time delays between droplet contact and initial gas formation, enabling calibration of the Arrhenius pre-exponential factors and activation energies for a global, one

  17. A copper-mediated reverse aromatic Finkelstein reaction in ionic liquid

    Directory of Open Access Journals (Sweden)

    Anh T.H. Nguyen

    2018-03-01

    Full Text Available We have developed a general method for reverse aromatic Finkelstein reactions. Good reaction yields were obtained when aryl iodides or aryl bromides were treated with copper halide salts as promoters in a 1-butyl-3-methylimidazolium bromide ([BMIM]Br ionic liquid (IL solvent at 140 °C for 8 h. Preliminary investigation supported that the copper salts were also the halide sources in halogen exchange reactions. The optimized conditions are applicable to a variety of substrates and have excellent functional group tolerance. Additionally, the [BMIM]Br solvent showed good stability for at least 10 consecutive runs. Results indicated that the [BMIM]Br solvent was recyclable for reverse aromatic Finkelstein reactions.

  18. Experimental Study of Na based Titanium Nanofluid-Water Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gunyeop; Kim, Soo Jae; Baek, Jehyun; Kim, Hyun Soo; Oh, Sun Ryung; Park, Hyun Sun; Kim, Moo Hwan [POSTECH, Pohang (Korea, Republic of)

    2015-10-15

    In KALIMER-600, a sodium-cooled fast reactor designed by KAERI, thermal energy is transported from high-temperature liquid Na (526 .deg. C at 0.1 MPa) to low temperature water (230 .deg. C at - 19.5 MPa) through a heat exchanger. If any leakage or rupture occurs during the operation of this heat exchanger, highly pressurized liquid water can penetrate into the liquid Na channels; this contact should instantly cause SWR. As reaction continues, liquid water is soon vaporized by pressure drop and huge amount of reaction heat. This generated water vapor expands large reaction area and increases sodium-water vapor reaction process. Therefore, the rapid generation of reaction product (like H{sub 2}) and water vapor increases the system pressure that can cause the system failure in SFR. To reduce this strong chemical reaction phenomena between Na and water, some we have focused on suppressing the chemical reactivity of liquid Na by dispersing nanoparticles (NPs). For the real application of NaTiNF, the pressure change induced by NaTiNF-water reaction is compared with Na-water reaction in the present study. NaTiNF contains 100nm of Ti NPs at 0.2 vol. %. The reaction rate of NaTiNF-water reaction is also investigated as reaction temperature increases. Sodium-water vapor reaction (SVR) will occur when an SWR accident occurs in SFR. In this manner, NaTiNF-water vapor reaction is experimentally performed for ensuring the suppression of chemical reactivity of NaTiNF in contact with water vapor. In the basic step for reducing risk of an SWR in SFR, we have experimentally verified the suppressed chemical reactivity of liquid sodium using Ti NPs through SWR and SVR experiments. In SWR, Na based titanium nanofluid (NaTiNF) shows lower pressure change than Na. As T{sub R} increases, P{sub max} in Na-water reaction increases while NaTiNF does not. The reaction rate of NaTiNF shows twice slower than that of Na. In SVR, NaTiNF shows slower temperature increase than Na. The distinct

  19. Mass transfer with complex chemical reactions in gas–liquid systems : two-step reversible reactions with unit stoichiometric and kinetic orders

    NARCIS (Netherlands)

    Vas Bhat, R.D.; Kuipers, J.A.M.; Versteeg, G.F.

    2000-01-01

    An absorption model to study gas–liquid mass transfer accompanied by reversible two-step reactions in the liquid phase has been presented. This model has been used to determine mass transfer rates, enhancement factors and concentration profiles over a wide range of process conditions. Although

  20. Mass transfer with complex chemical reactions in gas-liquid systems: two-step reversible reactions with unit stoichiometric and kinetic orders

    NARCIS (Netherlands)

    Vas bhat, R.D.; Kuipers, J.A.M.; Versteeg, Geert

    2000-01-01

    An absorption model to study gas¿liquid mass transfer accompanied by reversible two-step reactions in the liquid phase has been presented. This model has been used to determine mass transfer rates, enhancement factors and concentration profiles over a wide range of process conditions. Although

  1. Reactions of CH-acids with α,β-unsaturated aldehydes in ionic liquids

    DEFF Research Database (Denmark)

    Kryshtal, G. V.; Zhdankina, G. M.; Astakhova, Irina Kira

    2004-01-01

    Metal carbonate-catalyzed reactions of CH-acids (diethyl malonate, ethyl acetoacetate, ethyl cyanoacetate, and ethyl 2-acetyl- and 2-ethoxycarbonyl-5,9- dimethyldeca-4,8-dienoates) with α,β-unsaturated aldehydes (acrolein, crotonaldehyde, citral) were studied in an ionic liquid, 1-butyl-3......- methylimidazolium hexafluorophosphate [bmim][PF 6], and in a 1-butyl-3-methylimidazolium bromide ([bmim][Br]) - benzene system. The reactions with acrolein and crotonaldehyde afforded Michael addition products, those with citral resulted in Knoevenagel addition products. Sonication increased the yields...

  2. Using chiral ionic liquid additives to enhance asymmetric induction in a Diels-Alder reaction.

    Science.gov (United States)

    Goodrich, P; Nimal Gunaratne, H Q; Hall, L; Wang, Y; Jin, L; Muldoon, M J; Ribeiro, A P C; Pombeiro, A J L; Pârvulescu, V I; Davey, P; Hardacre, C

    2017-01-31

    A bis-oxazoline ligand has been complexed using Cu(ii) and Zn(ii) trifluoromethanesulfonate and a range of chiral ionic liquid (CIL) additives based on natural products were used as a co-catalyst for a Diels-Alder reaction. The catalytic performance of these systems was compared for the asymmetric Diels-Alder reaction between N-acryloyloxazolidinone and cyclopentadiene with and without the presence of a CIL additive. In the absence of the CIL, both catalysts resulted in low enantioselectivities in conventional solvents and ionic liquids. However, whilst only a minor effect of the CIL was observed for the Cu based catalyst, in the case of the Zn based catalyst, significant enhancements in endo enantioselectivity of up to 50% were found on the addition of a CIL.

  3. Non-Fermi Liquids as Highly Active Oxygen Evolution Reaction Catalysts.

    Science.gov (United States)

    Hirai, Shigeto; Yagi, Shunsuke; Chen, Wei-Tin; Chou, Fang-Cheng; Okazaki, Noriyasu; Ohno, Tomoya; Suzuki, Hisao; Matsuda, Takeshi

    2017-10-01

    The oxygen evolution reaction (OER) plays a key role in emerging energy conversion technologies such as rechargeable metal-air batteries, and direct solar water splitting. Herein, a remarkably low overpotential of ≈150 mV at 10 mA cm -2 disk in alkaline solutions using one of the non-Fermi liquids, Hg 2 Ru 2 O 7 , is reported. Hg 2 Ru 2 O 7 displays a rapid increase in current density and excellent durability as an OER catalyst. This outstanding catalytic performance is realized through the coexistence of localized d-bands with the metallic state that is unique to non-Fermi liquids. The findings indicate that non-Fermi liquids could greatly improve the design of highly active OER catalysts.

  4. Effects of gas flow on oxidation reaction in liquid induced by He/O{sub 2} plasma-jet irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Atsushi; Uchida, Giichiro, E-mail: uchida@jwri.osaka-u.ac.jp; Takenaka, Kosuke; Setsuhara, Yuichi [Joining and Welding Research Institute, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Kawasaki, Toshiyuki [Department of Mechanical and Electrical Engineering, Nippon Bunri University, Oita, Oita 870-0397 (Japan); Koga, Kazunori; Sarinont, Thapanut; Amano, Takaaki; Shiratani, Masaharu [Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka, Fukuoka 819-0395 (Japan)

    2015-07-28

    We present here analysis of oxidation reaction in liquid by a plasma-jet irradiation under various gas flow patterns such as laminar and turbulence flows. To estimate the total amount of oxidation reaction induced by reactive oxygen species (ROS) in liquid, we employ a KI-starch solution system, where the absorbance of the KI-starch solution near 600 nm behaves linear to the total amount of oxidation reaction in liquid. The laminar flow with higher gas velocity induces an increase in the ROS distribution area on the liquid surface, which results in a large amount of oxidation reaction in liquid. However, a much faster gas flow conversely results in a reduction in the total amount of oxidation reaction in liquid under the following two conditions: first condition is that the turbulence flow is triggered in a gas flow channel at a high Reynolds number of gas flow, which leads to a marked change of the spatial distribution of the ROS concentration in gas phase. Second condition is that the dimpled liquid surface is formed by strong gas flow, which prevents the ROS from being transported in radial direction along the liquid surface.

  5. Liquid-assisted grinding and ion pairing regulates percentage conversion and diastereoselectivity of the Wittig reaction under mechanochemical conditions.

    Science.gov (United States)

    Denlinger, Kendra Leahy; Ortiz-Trankina, Lianna; Carr, Preston; Benson, Kingsley; Waddell, Daniel C; Mack, James

    2018-01-01

    Mechanochemistry is maturing as a discipline and continuing to grow, so it is important to continue understanding the rules governing the system. In a mechanochemical reaction, the reactants are added into a vessel along with one or more grinding balls and the vessel is shaken at high speeds to facilitate a chemical reaction. The dielectric constant of the solvent used in liquid-assisted grinding (LAG) and properly chosen counter-ion pairing increases the percentage conversion of stilbenes in a mechanochemical Wittig reaction. Utilizing stepwise addition/evaporation of ethanol in liquid-assisted grinding also allows for the tuning of the diastereoselectivity in the Wittig reaction.

  6. Large leak sodium-water reaction code SWACS and its validation

    International Nuclear Information System (INIS)

    Miyake, O.; Shindo, Y.; Hiroi, H.; Tanabe, H.; Sato, M.

    1982-01-01

    A computer code SWACS for analyzing the large leak accident of an LMFBR steam generators has been developed and validated. Five tests data obtained by SWAT-3 test facility were compared with code results. In each of SWAT-3 tests, a double-ended guillotine rupture of one tube was simulated in a helical coil steam generator model with 1/2.5 scaled test vessel to the prototype SG. The analytical results, including an initial pressure spike, a propagated pressure in a secondary system, and a quasi-steady pressure, indicate that the overall large-leak event could be predicted in reasonably good agreement

  7. Advanced signal processing techniques for acoustic detection of sodium/water reaction

    International Nuclear Information System (INIS)

    Yughay, V.S.; Gribok, A.V.; Volov, A.N.

    1997-01-01

    In this paper results of development of a neural network technique for processing of acoustic background noise and injection noise of various media (argon, water steam, hydrogen) at test rigs and industrial steam generator are presented. (author). 3 refs, 9 figs, 3 tabs

  8. Detection of sodium/water reaction in a steam generator: Results of a 1995 benchmark test

    International Nuclear Information System (INIS)

    Oriol, L.

    1997-01-01

    The CEA analysis of the 1995 benchmark test has been focused on the location of the injections. Two techniques have been tested: the pulse timing technique, and the time-domain delay and sum beamforming technique. The two methods gave coherent locations of the injector even if there was a difference of 25% of the SGU height between the vertical locations. Prior to that analysis, the RMS values of the signals were calculated in different frequency bands. The results obtained in the 200-1000 Hz were used to draw a rough estimation of the beginnings of the injections in order to determine the parts of the records on which the location signal processing can be carried out. (author). 2 refs, 8 figs, 2 tabs

  9. Sodium-water reaction data needed by a utility for design assessment purposes

    Energy Technology Data Exchange (ETDEWEB)

    Bolt, P R [Fast Reactor Engineering, Barnwood, Gloucester (United Kingdom)

    1978-10-01

    Worldwide LMFBR experience has shown that LMFBR steam generator water/steam leakage into sodium can severely reduce steam generator availability and cause lengthy plant outages. Utility assessment LMFBR designs prior to placing an order to construct are likely to give emphasis to matters that can affect steam generator integrity, reliability and total operating cost. The data needed in carrying out such assessments is described. (author)

  10. Acoustic Leak Detection Testing Using KAERI Sodium-Water Reaction Signals for a SFR Steam Generator

    International Nuclear Information System (INIS)

    Kim, Tae-Joon; Jeong, Ji-Young; Kim, Jong-Man; Kim, Byung-Ho; Hahn, Do-Hee; Yugay, Valeriy S.

    2009-01-01

    The results of an experimental study of water in a sodium leak noise spectrum formation at 0.004-0.54 g/sec, various rates of water into a sodium leak, smaller than 1.0 g/sec, are presented. We focused on studying a micro leak detection with an increasing rate of water into sodium. On the basis of the experimental leak noise data manufactured in KAERI the simple dependency of an acoustic signal level from the rate of a micro and small leak at different frequency bands is presented to understand the principal analysis for the development of an acoustic leak detection methodology used in a K- 600 steam generator

  11. Sodium-water reaction data needed by a utility for design assessment purposes

    International Nuclear Information System (INIS)

    Bolt, P.R.

    1978-01-01

    Worldwide LMFBR experience has shown that LMFBR steam generator water/steam leakage into sodium can severely reduce steam generator availability and cause lengthy plant outages. Utility assessment LMFBR designs prior to placing an order to construct are likely to give emphasis to matters that can affect steam generator integrity, reliability and total operating cost. The data needed in carrying out such assessments is described. (author)

  12. Study on fine particles influence on sodium sulfite and oxygen gas-liquid reaction

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Shuchang; Zhao, Bo; Wang, Shujuan; Zhuo, Yuqun; Chen, Changhe [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering; Ministry of Education, Beijing (China). Key Lab. for Thermal Science and Power Engineering

    2013-07-01

    Wet limestone scrubbing is the most common flue gas desulfurization process for control of sulfur dioxide emissions from the combustion of fossil fuels, and forced oxidation is a key part of the reaction. During the reaction which controlled by gas-liquid mass transfer, the fine particles' characteristic, size, solid loading and temperature has a great influence on gas-liquid mass transfer. In the present work is to explain how these factors influence the reaction between Na{sub 2}SO{sub 3} and O{sub 2} and find the best react conditions through experiment. The oxidation rate was experimentally studied by contacting pure oxygen with a sodium sulfite solution with active carbon particle in a stirred tank, and the system pressure drop was record by the pressure sensor. At the beginning the pressure is about 215 kPa and Na{sub 2}SO{sub 3} is about 0.5mol/L. The temperature is 40, 50, 60, 70, 80 C. Compare the results of no particles included, we can conclude that high temperature, proper loadings and smaller particles resulting in higher mass transfer coefficients k{sub L}.

  13. Environmentally friendly room temperature strecker reaction:one-pot synthesis of α-aminonitriles in ionic liquid

    International Nuclear Information System (INIS)

    Mojtahedi, M. M.; Abaee, M.S.; Abbasi, H.

    2006-01-01

    A three component efficient and facile procedure is developed for the synthesis of a-aminonitriles from aromatic-and aliphatic aldehydes, amines, and trimethylsilyl cyanide in 1-butyl-3-methyl-1H-imidazolium perchlorate ([bmim][C1O 4 ]) ionic liquid as the reaction medium at room temperature. Excellent yields are obtained in this one-pot procedure with short reaction times and the ionic liquid medium reused several times in a row

  14. The international symposium on 'chemical engineering of gas-liquid-solid catalyst reactions'

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, H

    1978-06-01

    A report on the International Symposium on ''Chemical Engineering of Gas-Liquid-Solid Catalyst Reactions'', sponsored by the University of Liege (3/2-3/78), covers papers on the hydrodynamics, modeling and simulation, operating behavior, and chemical kinetics of trickle-bed reactors; scale-up of a trickle-bed reactor for hydrotreating Kuwait vacuum distillate; experimental results obtained in trickle-bed reactors for hydroprocessing atmospheric residua, hydrogenation of methylstyrene, hydrogenation of butanone, and hydrodemetallization of petroleum residua; advantages and disadvantages of various three-phase reactor types (e.g., for the liquid-phase hydrogenation of carbon monoxide to benzene, SNG, or methanol) and hydrodynamics, mass and heat transfer, and modeling of bubble columns with suspended catalysts (slurry reactors), and their applications (e.g., in SNG and fermentation processes).

  15. Competitive and successive reactions in the position cluster and energy state of positronium in the liquids

    International Nuclear Information System (INIS)

    Didierjean, F.

    1991-10-01

    By combining two independent positron annihilation techniques, it is shown that, in polar solvents, the halogenated compounds inhibit positronium formation by quasi-free electron scavenging followed by positron capture. This sequence occurs before halide detachment intervenes. Studying mixtures of solutes allows both to confirm the existence of these successive reactions and to stress the influence, towards positronium formation, of the trap depth for the electron captured by nitrates, whether ion associated or not, in methanol. Finally, experiments in the presence of a magnetic field allow to conclude that the formed positronium is very rapidly thermalized, then localised in a potential well in the liquids, the so-called bubble [fr

  16. Spectacular Rate Enhancement of the Diels-Alder Reaction at the Ionic Liquid/n-Hexane Interface.

    Science.gov (United States)

    Beniwal, Vijay; Manna, Arpan; Kumar, Anil

    2016-07-04

    The use of the ionic liquid/n-hexane interface as a new class of reaction medium for the Diels-Alder reaction gives large rate enhancements of the order of 10(6) to 10(8) times and high stereoselectivity, as compared to homogeneous media. The rate enhancement is attributed to the H-bonding abilities and polarities of the ionic liquids, whereas the hydrophobicity of ionic liquids was considered to be the factor in controlling stereoselectivity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Investigations in anhydrous liquid ammonia. Reaction of group 2, 4, 5, 11 metal and actinoids compounds

    International Nuclear Information System (INIS)

    Woidy, Patrick

    2014-01-01

    The solubility and reactivity of metal halides, transition metal halides, and actinoid halides in liquid ammonia can lead to new starting materials for the synthesis of fluorides in low oxidation states or for nitrides via a ''low-temperature route''. In this context the ability of metal and actinoid halides to act as an acceptor for or donor of fluoride ions is also of interest. Four different systems were investigated in this study. In the first section, the synthesis and characterization of new compounds were carried out in the system CuX/NH 3 (X = F, Cl, Br, I, and CN) and lead to a ligand stabilized monovalent copper fluoride as a main result. In the second section, the solubility of uranyl compounds and uranium halides in liquid ammonia was investigated and the products were characterized. In the third section, alkali metal thorates were synthesized. Their solubility in liquid ammonia and their behavior as an acceptor for fluoride ions was investigated. In the last section, the results on the solubility behavior of transition metal halides in liquid ammonia and their coordination behavior are presented. In the first system CuX/NH 3 several new compounds, such as [Cu(NH 3 ) 3 ]X (X = Br, I or CN) were synthesized and characterized. The reactions of this compounds with fluoride ion donors (NH 4 F or Me 4 NF) led unfortunately not to the monovalent copper fluoride CuF. The comproportionation reaction of Cu and CuF 2 in liquid ammonia lead to the compounds [Cu(NH 3 ) 3 ] 2 [Cu 2 (NH 3 ) 2 ] . 4 NH 3 and [Cu(NH 3 ) 2 ]F . NH 3 . For the preparation of binary CuF, various decomposition experiments were executed on the compound [Cu(NH 3 ) 2 ]F . NH 3 which resulted in different decomposition products. In additional studies various complexes of divalent copper was investigated and with the compound [Cu(NH 3 ) 5 ]F 2 . NH 3 the solubility of fluoride containing substances in liquid ammonia could be shown. Studies of six- and tetravalent uranium

  18. Reaction rates and electrical resistivities of the hydrogen isotopes with, and their solubilities in, liquid lithium

    International Nuclear Information System (INIS)

    Pulham, R.J.; Adams, P.F.; Hubberstey, P.; Parry, G.; Thunder, A.E.

    1976-01-01

    The rate of reaction, k, of hydrogen and of deuterium with liquid lithium have been determined up to pressures of 20kNm -2 and at temperatures between 230 and 270 0 C. The reaction is first order with an apparent activation energy of 52.8 and 55.2 kJmol -1 for hydrogen and deuterium, respectively. The deuterium isotope effect, k/sub H/k/sub D/, decreases from 2.95 at 230 to 2.83 at 270 0 C. Tritium is predicted to react even more slowly than deuterium. The freezing point of lithium is depressed by 0.082 and 0.075 0 C, respectively, by dissolved hydride and deuteride giving eutectics at 0.016 mol percent H and 0.012 mol percent D in the metal-salt phase diagrams. The depression and eutectic concentration are expected to be less for tritium. The increase in the resistivity of liquid lithium caused by dissolved hydrogen isotopes is linear and relatively large, 5 x 10 -8 Ωm (mol percent H or D) -1 . The solubility of lithium hydride and deuteride was determined from the marked change in resistivity on saturation. The liquidus of the metal-salt phase diagram rises steeply from the eutectic point to meet the two-immiscible liquid region. Tritium is expected to be less soluble than deuterium. The partial molar enthalpies of solution are 44.2 and 55.0 kJmol -1 for hydrogen and deuterium, respectively. These values are used to calculate the solvation enthalpies of the isotope anions in the metal

  19. Identification of liquid-phase decomposition species and reactions for guanidinium azotetrazolate

    International Nuclear Information System (INIS)

    Kumbhakarna, Neeraj R.; Shah, Kaushal J.; Chowdhury, Arindrajit; Thynell, Stefan T.

    2014-01-01

    Highlights: • Guanidinium azotetrazolate (GzT) is a high-nitrogen energetic material. • FTIR spectroscopy and ToFMS spectrometry were used for species identification. • Quantum mechanics was used to identify transition states and decomposition pathways. • Important reactions in the GzT liquid-phase decomposition process were identified. • Initiation of decomposition occurs via ring opening, releasing N 2 . - Abstract: The objective of this work is to analyze the decomposition of guanidinium azotetrazolate (GzT) in the liquid phase by using a combined experimental and computational approach. The experimental part involves the use of Fourier transform infrared (FTIR) spectroscopy to acquire the spectral transmittance of the evolved gas-phase species from rapid thermolysis, as well as to acquire spectral transmittance of the condensate and residue formed from the decomposition. Time-of-flight mass spectrometry (ToFMS) is also used to acquire mass spectra of the evolved gas-phase species. Sub-milligram samples of GzT were heated at rates of about 2000 K/s to a set temperature (553–573 K) where decomposition occurred under isothermal conditions. N 2 , NH 3 , HCN, guanidine and melamine were identified as products of decomposition. The computational approach is based on using quantum mechanics for confirming the identity of the species observed in experiments and for identifying elementary chemical reactions that formed these species. In these ab initio techniques, various levels of theory and basis sets were used. Based on the calculated enthalpy and free energy values of various molecular structures, important reaction pathways were identified. Initiation of decomposition of GzT occurs via ring opening to release N 2

  20. What happens when iron becomes wet? Observation of reactions at interfaces between liquid and metal surfaces

    CERN Document Server

    Kimura, M

    2003-01-01

    Synchrotron-radiation has been applied to investigation of interfaces between liquid and metal surfaces, with a special attention to corrosion. Three topics are shown: (1) nano structures of rusts formed on steel after atmospheric corrosion. Evolution of 'Fe(O, OH) sub 6 network' is the key to understand how the durable rusts prevent from formation of more rusts. (2) In situ observation of reactions at the interface has been carried out for localized corrosion of stainless steel. It is shown that change in states of Cr sup 3 sup + and Br sup - ions near the interface is deeply related with a breakout of the passivation film. (3) A structural phase transformation on a Cu sub 3 Au(001) surface was investigated. Ordering remains even at a temperature higher than the bulk-critical temperature, showing surface-induced ordering. These approaches gives us crucial information for a new steel-product. (author)

  1. Modifying surface resistivity and liquid moisture management property of keratin fibers through thiol-ene click reactions.

    Science.gov (United States)

    Yu, Dan; Cai, Jackie Y; Church, Jeffrey S; Wang, Lijing

    2014-01-22

    This paper reports on a new method for improving the antistatic and liquid moisture management properties of keratinous materials. The method involves the generation of thiols by controlled reduction of cystine disulfide bonds in keratin with tris(2-carboxyethyl) phosphine hydrochloride and subsequent grafting of hydrophilic groups onto the reduced keratin by reaction with an acrylate sulfonate or acrylamide sulfonate through thiol-ene click chemistry. The modified substrates were characterized with Raman spectroscopy and scanning electron microscopy and evaluated for their performance changes in liquid moisture management, surface resistivity, and wet burst strength. The results have revealed that the thiol-acrylate reaction is more efficient than the thiol-acrylamide reaction, and the keratinous substrate modified with an acrylate sulfonate salt exhibits significantly improved antistatic and liquid moisture management properties.

  2. Analysis of gas absorption to a thin liquid film in the presence of a zero-order chemical reaction

    Science.gov (United States)

    Rajagopalan, S.; Rahman, M. M.

    1995-01-01

    The paper presents a detailed theoretical analysis of the process of gas absorption to a thin liquid film adjacent to a horizontal rotating disk. The film is formed by the impingement of a controlled liquid jet at the center of the disk and subsequent radial spreading of liquid along the disk. The chemical reaction between the gas and the liquid film can be expressed as a zero-order homogeneous reaction. The process was modeled by establishing equations for the conservation of mass, momentum, and species concentration and solving them analytically. A scaling analysis was used to determine dominant transport processes. Appropriate boundary conditions were used to solve these equations to develop expressions for the local concentration of gas across the thickness of the film and distributions of film height, bulk concentration, and Sherwood number along the radius of the disk. The partial differential equation for species concentration was solved using the separation of variables technique along with the Duhamel's theorem and the final analytical solution was expressed using confluent hypergeometric functions. Tables for eigenvalues and eigenfunctions are presented for a number of reaction rate constants. A parametric study was performed using Reynolds number, Ekman number, and dimensionless reaction rate as parameters. At all radial locations, Sherwood number increased with Reynolds number (flow rate) as well as Ekman number (rate of rotation). The enhancement of mass transfer due to chemical reaction was found to be small when compared to the case of no reaction (pure absorption), but the enhancement factor was very significant when compared to pure absorption in a stagnant liquid film. The zero-order reaction processes considered in the present investigation included the absorption of oxygen in aqueous alkaline solutions of sodiumdithionite and rhodium complex catalyzed carbonylation of methanol. Present analytical results were compared to previous theoretical

  3. Effect of liquid sodium thermochemical reactions with stainless steels on mechanical response

    International Nuclear Information System (INIS)

    Subbaraman, G.; Reifsnider, K.L.

    1976-01-01

    An analytical approach is presented to study the elastic response of an LMFBR fuel clad subject to strong property degradation in liquid sodium environment and internal poison pressure, at the gas plenum section of the fuel pin. The nature and analysis of the thermochemical reactions and the available experimental data are briefly reviewed. Property variations in the radial direction due to these inservice reactions are represented by a generalized, continuous function, f(r), which is introduced into the constitutive equations of stress equilibrium. By introducing an adjustable constant A into a specific form of f(r), various severities in the variation of the elastic parameters through the thickness of the clad are accommodated and particular analytical solutions are obtained for the displacement. Closed form solutions, which are available for particular values of A, are used as validity checks in computing the more general solutions. The stress-strain responses including the deviatoric stresses used in creep analyses are presented for several cases. The merits of the analytical formulation of the problem and the need to include similar approaches in fuel performance calculations are stated

  4. Magnetic Field Effects on Photoelectrochemical Reactions of Porphyrin-Viologen Linked Compounds in an Ionic Liquid

    Science.gov (United States)

    Tahara, Hironobu; Yonemura, Hiroaki; Harada, Satoko; Yamada, Sunao

    2011-08-01

    Magnetic field effects (MFEs) on photoelectrochemical reactions of three porphyrin-viologen linked compounds with various methylene groups [ZnP(n)V (n=4,6,8)] were examined in 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) as an ionic liquid using a two-electrode cell. Stable anodic photocurrents are produced by irradiating ZnP(n)V (n=4,6,8) in [BMIM][BF4] with visible light, and the MFEs on photocurrents were clearly observed in ZnP(n)V (n=4,6,8). The MFEs on photocurrents increase with magnetic field for lower magnetic fields (B ≤200 mT) and are constant for higher magnetic fields (B > 200 mT). The magnitude of the MFEs in ZnP(n)V (n=6,8) are larger than that in ZnP(4)V. The MFEs can be explained by radical pair mechanism. The magnitude of the MFEs is larger than those in electrodes modified with ZnP(n)V (n=4,6,8) as Langmuir-Blodgett films. The results are most likely attributable to the properties of [BMIM][BF4] and the mechanism of photoelectrochemical reaction.

  5. Unattended reaction monitoring using an automated microfluidic sampler and on-line liquid chromatography.

    Science.gov (United States)

    Patel, Darshan C; Lyu, Yaqi Fara; Gandarilla, Jorge; Doherty, Steve

    2018-04-03

    In-process sampling and analysis is an important aspect of monitoring kinetic profiles and impurity formation or rejection, both in development and during commercial manufacturing. In pharmaceutical process development, the technology of choice for a substantial portion of this analysis is high-performance liquid chromatography (HPLC). Traditionally, the sample extraction and preparation for reaction characterization have been performed manually. This can be time consuming, laborious, and impractical for long processes. Depending on the complexity of the sample preparation, there can be variability introduced by different analysts, and in some cases, the integrity of the sample can be compromised during handling. While there are commercial instruments available for on-line monitoring with HPLC, they lack capabilities in many key areas. Some do not provide integration of the sampling and analysis, while others afford limited flexibility in sample preparation. The current offerings provide a limited number of unit operations available for sample processing and no option for workflow customizability. This work describes development of a microfluidic automated program (MAP) which fully automates the sample extraction, manipulation, and on-line LC analysis. The flexible system is controlled using an intuitive Microsoft Excel based user interface. The autonomous system is capable of unattended reaction monitoring that allows flexible unit operations and workflow customization to enable complex operations and on-line sample preparation. The automated system is shown to offer advantages over manual approaches in key areas while providing consistent and reproducible in-process data. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Thermochemistry of ionic liquid-catalysed reactions. Isomerisation and transalkylation of tert-alkyl-benzenes. Are these systems ideal?

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.; Emel'yanenko, Vladimir N.; Hopmann, Elisabeth; Arlt, Wolfgang

    2010-01-01

    The chemical equilibrium of mutual interconversions of tert-alkyl-benzenes was studied in the temperature range (286 to 423) K using chloroaluminate ionic liquids as a catalyst. The knowledge of the activity coefficients is required in order to obtain the thermodynamic equilibrium constants K a . A well established procedure, COSMO-RS, has been used to assess activity coefficients of the reaction participants in the liquid phase. Enthalpies of five reactions of isomerisation and transalkylation of tert-alkyl-benzenes were obtained from temperature dependences of the corresponding equilibrium constants in the liquid phase. For the sake of comparison, high-level ab initio calculations of the reaction participants have been performed using the Gaussian-03 program package. Absolute electronic energy values of the molecules have been obtained using B3LYP and G3MP2 level. Using these results enthalpies of reaction of isomerisation and transalkylation of tert-alkyl-benzenes in the liquid phase based on the first principles are found to be in good agreement with the data obtained from the thermochemical measurements.

  7. Microporous hollow fibre membrane modules as gas-liquid contactors. Part 2. Mass transfer with chemical reaction

    NARCIS (Netherlands)

    Kreulen, H.; Versteeg, G.F.; Swaaij, W.P.M. van

    1993-01-01

    Absorption determined by mass transfer in the liquid is described well with the Graetz-Lévèque equation adapted from heat transfer. The influence of a chemical reaction on the mass transfer was simulated with a numerical model and tested on the absorption of CO2 in a hydroxide solution. Absorption

  8. Producing laminated NiAl with bimodal distribution of grain size by solid–liquid reaction treatment

    DEFF Research Database (Denmark)

    Fan, G.H.; Wang, Q.W.; Du, Y.

    2014-01-01

    The prospect of combining laminated structure design and grain size tailoring to toughen brittle materials is examined. Laminated NiAl consisting of coarse-grained layers and fine-grained layers was fabricated by solid–liquid reaction treatment of stacking Ni and Al foils. The fracture toughness...

  9. Ionic liquids as recyclable and separable reaction media in Rh-catalyzed decarbonylation of aromatic and aliphatic aldehydes

    DEFF Research Database (Denmark)

    Malcho, Phillip; Garcia-Suarez, Eduardo J.; Riisager, Anders

    2014-01-01

    Ionic liquids (ILs) have been applied as recyclable reaction media in the decarbonylation of aldehydes in the presence of a rhodium-phosphine complex catalyst. The performance of several new catalytic systems based on imidazolium-based ILs and [Rh(dppp)2]Cl (dppp: 1,3-diphenylphosphinopropane) were...

  10. The phase transport and reactions of γ-irradiated aqueous-ionic liquids

    International Nuclear Information System (INIS)

    Howett, S.; Joseph, J.; Noel, J.J.; Wren, J.C.

    2010-01-01

    A novel technology based on the transfer of chemical species across water/ionic liquid interfaces via specific complexation reactions is currently being considered for the separation and sequestration of metal ion contaminants from radioactive waste effluents in the nuclear fuel cycle. An ideal solvent for these applications should have a high intrinsic selectivity for a targeted metal or group of metals (e.g., trans-Pu actinides, lanthanides, or other fission products), an efficient switching mechanism (between complexation and decomplexation), and a high immiscibility with aqueous solutions. These characteristics must be maintained in the chemical, radiation, and mass transport environments present during the separation process. Ionic liquids (ILs) have an almost negligible vapour pressure and high thermal stability. Their ability to dissolve a wide range of substrate molecules and potential to be highly resilient in radiation fields make ILs particularly promising media. The separation efficiency of the biphasic system will depend on many parameters, including the aqueous oxidation state of the targeted metal ion, and the thermodynamics and kinetics of interfacial transport and metal-ligand complex formation at the water/IL interface or in the IL phase. The most uncertain and unstudied area for these applications is the effect of ionizing radiation on the stability and separation efficiency of the biphasic system. The present study investigates the effect of γ-radiation on gas/IL and water/IL interfacial stability and mass transfer with trihexyltetradecylphosphonium bis(trifluoromethyl-sulfonyl)imide, a phosphonium-based IL. The IL, in contact with either gas or water, was irradiated at a dose rate of 6.4 kGy·h -1 . Gas-phase samples were analyzed by gas chromatography-mass spectrometry (GC-MS) and the changes in the IL and aqueous phases were monitored by conductivity measurements and Raman spectroscopy. In this paper we discuss these observations and their

  11. Characterization of electrochemically deposited films from aqueous and ionic liquid cobalt precursors toward hydrogen evolution reactions

    Energy Technology Data Exchange (ETDEWEB)

    Dushatinski, Thomas; Huff, Clay; Abdel-Fattah, Tarek M., E-mail: fattah@cnu.edu

    2016-11-01

    Highlights: • Co films deposition via aqueous and ionic liquid Precursors. • Hydrogen evolution produced from reactive surfaces. • Co deposited films characterized by SEM, AFM, EDX and XRD techniques. - Abstract: Electrodepositions of cobalt films were achieved using an aqueous or an ethylene glycol based non-aqueous solution containing choline chloride (vitamin B4) with cobalt chloride hexahydrate precursor toward hydrogen evolution reactions from sodium borohydride (NaBH{sub 4}) as solid hydrogen feedstock (SHF). The resulting cobalt films had reflectivity at 550 nm of 2.2% for aqueously deposited films (ACoF) and 1.3% for non-aqueously deposited films (NCoF). Surface morphology studied by scanning electron microscopy showed a positive correlation between particle size and thickness. The film thicknesses were tunable between >100 μm and <300 μm for each film. The roughness (Ra) value measurements by Dektak surface profiling showed that the NCoF (Ra = 165 nm) was smoother than the ACoF (Ra = 418 nm). The NCoFs and ACoFs contained only α phase (FCC) crystallites. The NCoFs were crystalline while the ACoFs were largely amorphous from X-ray diffraction analysis. The NCoF had an average Vickers hardness value of 84 MPa as compared to 176 MPa for ACoF. The aqueous precursor has a single absorption maximum at 510 nm and the non-aqueous precursor had three absorption maxima at 630, 670, and 695 nm. The hydrogen evolution reactions over a 1 cm{sup 2} catalytic surface with aqueous NaBH{sub 4} solutions generated rate constants (K) = equal to 4.9 × 10{sup −3} min{sup −1}, 4.6 × 10{sup −3} min{sup −1}, and 3.3 × 10{sup −3} min{sup −1} for ACoF, NCoF, and copper substrate respectively.

  12. Simultaneous measurements of reactive scalar and velocity in a planar liquid jet with a second-order chemical reaction

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Tomoaki; Sakai, Yasuhiko; Nagata, Kouji; Terashima, Osamu [Nagoya University, Department of Mechanical Science and Engineering, Nagoya (Japan); Kubo, Takashi [Meijo University, Faculty of Science and Technology, Nagoya (Japan)

    2012-11-15

    This paper presents a new experimental approach for simultaneous measurements of velocity and concentration in a turbulent liquid flow with a chemical reaction. For the simultaneous measurements, we developed a combined probe consisting of an I-type hot-film probe and an optical fiber probe based on the light absorption spectrometric method. In a turbulent planar liquid jet with a second-order chemical reaction (A+B{yields}R), streamwise velocity and concentrations of all reactive species are measured by the combined probe. The turbulent mass fluxes of the reactive species are estimated from the simultaneous measurements. The results show that the influence of the chemical reaction on the turbulent mass flux of the reactant species near the jet exit is different from its influence in other regions, and the turbulent mass flux of the product species has a negative value near the jet exit and a positive value in other regions. (orig.)

  13. Novel synthesis of methoxymethyl benzene by electrochemical coupling reaction of toluene with methanol in ionic liquid media.

    Science.gov (United States)

    Chen, Fengtao; Wang, Bo; Ma, Hongzhu

    2009-06-15

    An ionic liquid (1-butyl-3-methylimidazolium dibutyl phosphate) was prepared and characterized by cyclic voltammogram (CV) and Fourier transform infrared spectrometer (FT-IR). The ionic liquid exhibited good catalytic activity for the electrochemical reaction of toluene with methanol assisted with a pair of porous graphite plane electrodes and product yield higher than 56% was observed. In addition, the electrochemical process was detected by UV-vis spectrum and the products were analyzed by gas chromatography/mass spectrometry (GC/MS). According to the experimental results, a possible free radical reaction mechanism was proposed. It may be concluded that a simply and feasible electrochemical coupling reaction at room temperature and atmospheric pressure may be possible. Compared with methyl tert-butyl ether (MTBE), the main product (methoxymethyl benzene) used as booster to improve fuel combustion was also studied.

  14. Deactivation of solid catalysts in liquid media: the case of leaching of active sites in biomass conversion reactions

    DEFF Research Database (Denmark)

    Sádaba, Irantzu; Lopez Granados, Manuel; Riisager, Anders

    2015-01-01

    This review is aimed to be a brief tutorial covering the deactivation of solid catalysts in the liquid phase, with specific focus on leaching, which can be especially helpful to researchers not familiarized with catalytic processes in the liquid phase. Leaching refers to the loss of active species....... However, as a consequence of the development of new processes for biorefineries, an increasing number of reactions deal with liquid media, and thus, the stability and reusability of a solid catalyst in this situation represent a huge challenge that requires specific attention. Leaching of active phases...... is particularly problematic because of its irreversibility and it can be one of the main causes of catalyst deactivation in liquid media, threatening the sustainability of the process. This tutorial review presents a survey of the main aspects concerning the deactivation due to leaching of active species from...

  15. Adaptable liquid crystal elastomers with transesterification-based bond exchange reactions.

    Science.gov (United States)

    Hanzon, Drew W; Traugutt, Nicholas A; McBride, Matthew K; Bowman, Christopher N; Yakacki, Christopher M; Yu, Kai

    2018-02-14

    Adaptable liquid crystal elastomers (LCEs) have recently emerged to provide a new and robust method to program monodomain LCE samples. When a constant stress is applied with active bond exchange reactions (BERs), polymer chains and mesogens gradually align in the strain direction. Mesogen alignment is maintained after removing the BER stimulus (e.g. by lowering the temperature) and the programmed LCE samples exhibit free-standing two-way shape switching behavior. Here, a new adaptable main-chain LCE system was developed with thermally induced transesterification BERs. The network combines the conventional properties of LCEs, such as an isotropic phase transition and soft elasticity, with the dynamic features of adaptable network polymers, which are malleable to stress relaxation due to the BERs. Polarized Fourier transform infrared measurements confirmed the alignment of polymer chains and mesogens after strain-induced programming. The influence of the creep stress, temperature, and time on the strain amplitude of two-way shape switching was examined. The LCE network demonstrates an innovative feature of reprogrammability, where the reversible shape-switching memory of programmed LCEs is readily deleted by free-standing heating as random BERs disrupt the mesogen alignment, so LCEs are reprogrammed after returning to the polydomain state. Due to the dynamic nature of the LCE network, it also exhibits a surface welding effect and can be fully dissolved in the organic solvent, which might be utilized for green and sustainable recycling of LCEs.

  16. WS{sub 2} nanosheets based on liquid exfoliation as effective electrocatalysts for hydrogen evolution reaction

    Energy Technology Data Exchange (ETDEWEB)

    Han, Guan-Qun [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Yan-Ru; Hu, Wen-Hui [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Dong, Bin, E-mail: dongbin@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Li, Xiao; Chai, Yong-Ming; Liu, Yun-Qi [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Chen-Guang, E-mail: cgliu@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China)

    2015-11-01

    WS{sub 2} nanosheets (WS{sub 2} NSs) as electrocatalysts for hydrogen evolution reaction (HER) have been prepared based on liquid exfoliation in dimethyl-formamide (DMF) via a direct dispersion and ultrasonication method. X-ray diffraction (XRD) shows the decreasing crystalline of the exfoliated WS{sub 2} (E-WS{sub 2}). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the as prepared E-WS{sub 2} consists of a few two-dimensional nanosheets, with large wrinkles on the surface. Electrochemical measurements show an excellent activity and stability of the E-WS{sub 2}, with a low overpotential of 80 mV and high current density (10 mA cm{sup −2}, at η = 205 mV), which indicates that through the process of exfoliation in DMF, both the dispersion and the amount of active sites have been improved greatly. Therefore, DMF is a promising alternative for exfoliating two-dimensional nanomaterials for highly efficient HER electrocatalysts. - Highlights: • A facile exfoliation process in DMF has been used to prepare E-WS{sub 2} for HER. • E-WS{sub 2} shows the better electrocatalytic activity than bulk WS{sub 2}. • DMF provides a promising alternative for enhancing exfoliation of 2D materials.

  17. WS_2 nanosheets based on liquid exfoliation as effective electrocatalysts for hydrogen evolution reaction

    International Nuclear Information System (INIS)

    Han, Guan-Qun; Liu, Yan-Ru; Hu, Wen-Hui; Dong, Bin; Li, Xiao; Chai, Yong-Ming; Liu, Yun-Qi; Liu, Chen-Guang

    2015-01-01

    WS_2 nanosheets (WS_2 NSs) as electrocatalysts for hydrogen evolution reaction (HER) have been prepared based on liquid exfoliation in dimethyl-formamide (DMF) via a direct dispersion and ultrasonication method. X-ray diffraction (XRD) shows the decreasing crystalline of the exfoliated WS_2 (E-WS_2). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the as prepared E-WS_2 consists of a few two-dimensional nanosheets, with large wrinkles on the surface. Electrochemical measurements show an excellent activity and stability of the E-WS_2, with a low overpotential of 80 mV and high current density (10 mA cm"−"2, at η = 205 mV), which indicates that through the process of exfoliation in DMF, both the dispersion and the amount of active sites have been improved greatly. Therefore, DMF is a promising alternative for exfoliating two-dimensional nanomaterials for highly efficient HER electrocatalysts. - Highlights: • A facile exfoliation process in DMF has been used to prepare E-WS_2 for HER. • E-WS_2 shows the better electrocatalytic activity than bulk WS_2. • DMF provides a promising alternative for enhancing exfoliation of 2D materials.

  18. Controlling Solid–Liquid Conversion Reactions for a Highly Reversible Aqueous Zinc–Iodine Battery

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Huilin; Li, Bin; Mei, Donghai; Nie, Zimin; Shao, Yuyan; Li, Guosheng; Li, Xiaohong S.; Han, Kee Sung; Muller, Karl T.; Sprenkle, Vincent L.; Liu, Jun

    2017-10-30

    Aqueous rechargeable batteries are desirable for many energy storage applications due to their low cost and high safety. However, low capacity and short cycle life are the significant obstacles to their practical applications. Here, we demonstrate a highly reversible aqueous zinc-iodine battery using encapsulated iodine in microporous active carbon fibers (ACFs) as cathode materials through the rational control of solid-liquid conversion reactions. The experiments and density function theory (DFT) calculations were employed to investigate the effects of solvents and properties of carbon hosts, e.g. pore size, surface chemistries, on the adsorption of iodine species. The rational manipulation of the competition between the adsorption in carbon and solvation in electrolytes for iodine species is responsible for the high reversibility and cycling stability. The zinc-iodine batteries deliver a high capacity of 180 mAh g-1 at 1C and a stable cycle life over 3000 cycles with ~90% capacity retention as well as negligible self-discharge. We believe the principles for stabilizing the zinc-iodine system could provide new insight into conversion systems such as Li-S systems.

  19. Derivatization reactions in the gas—liquid chromatographic analysis of drugs in biological fluids

    NARCIS (Netherlands)

    Hulshoff, A.; Lingeman, H.

    1984-01-01

    Alkylation, acylation, silylation and other derivatization reactions applied to the gas chromatographic analysis of drugs in biological matrices are reviewed. Reaction conditions are discussed in relation to reaction mechanisms. Detector-oriented labelling of drugs, and derivatization with chiral

  20. Deviation from the kinetic law of mass action for reactions induced by binary encounters in liquid solutions

    International Nuclear Information System (INIS)

    Doktorov, Alexander B; Kipriyanov, Alexey A

    2007-01-01

    In considering the irreversible chemical reaction A+B→ C+B in liquid solutions two many-particle approaches to the derivation of binary non-Markovian kinetic equations are compared: simple superposition decoupling and a method of extracting 'pair' channels from three-particle correlation evolution. It is shown that both methods provide an almost identical description of this reaction. However, in studies of reversible reactions in liquid solutions only the channel extraction method gives a correct physically clear description of the reaction though it consists of a sequence of steps: the development of integral encounter theory (IET), effective pairs approximation (EPA), modified encounter theory (MET), and the final regular form (RF) of kinetic equations. It is shown that the rate equations often encountered in the literature correspond to the independence of transient channels of 'scattering' in the bimolecular reversible reaction (A+B -B), while the independent transient channel of 'decay' in the reversible reactionA+B -C is defined solely by time integral convolution. In the general case transient channels in non-Markovian theory are not independent, and their interference manifests itself as a non-Markovian inhomogeneous source in binary non-Markovian kinetic equations in regular form. Based on the derived equations new universal kinetics (independent of models) of chemical equilibrium attainment have been obtained. It is shown that these kinetics can differ essentially from the kinetics corresponding to the kinetic law of mass action of formal chemical kinetics

  1. Determination of redox reaction rates and orders by in situ liquid cell electron microscopy of Pd and Au solution growth.

    Science.gov (United States)

    Sutter, Eli A; Sutter, Peter W

    2014-12-03

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important, as they provide direct insight into processes in liquids, such as solution growth of nanoparticles, among others. In liquid cell TEM/STEM redox reaction experiments, the hydrated electrons e(-)aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e(-)aq generated by the electron beam during in situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e(-)aq]. By comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e(-)aq] but also the rate of reduction of a metal-ion complex to zerovalent metal atoms in solution.

  2. Effects of operating conditions on compositional characteristics and reaction kinetics of liquid derived by delayed coking of nigerian petroleum residue

    Directory of Open Access Journals (Sweden)

    O. O. Bello

    2006-09-01

    Full Text Available The thermal upgrading of Nigerian petroleum residue was studied at relatively low pressure in a delayed coking reactor system. In this work, the intent was to investigate the effects of process variables such as reaction temperature (200(0C to 600(0C, reaction time (0 to 120min, additive concentration loading and additive-to-residue ratio on the amounts and quality of organic liquid product (OLP. The liquid products derived from the delayed coking process were characterized by means of instrumental analysis of gas-liquid chromatography. Results obtained from the analyses of the OLP revealed an upward trend of the conversion process and the selectivity of the aromatic compounds with additive-to-residue ratio (ARR and increase in temperature. This led to maximum yield of 37.2% achieved with ARR of 5 compared to 31% achieved with ordinary thermal conversion. The selectivity for aromatic hydrocarbons was maximum at 83.1wt% the selectivity towards aromatics and aliphatic hydrocarbons were highest for methanol-potassium hydroxide and methanol respectively. In all additive system cases, maximum OLP was produced at an optimum reaction temperature of 370(0C in the delayed coking reactor and at higher residence time. The gaseous product consisted of carbon monoxide and carbon dioxide and C1 - C6 hydrocarbons, which amounted to about 20 to 30 wt% of liquid distillate. The information obtained in this study show that the organic liquid products are amenable to characterization procedure and provided the basis for the identification of processes for upgrading Nigerian petroleum residue and such other starting materials such as bitumen or fossil fuel coal liquids.

  3. Modelling of gas-liquid reactors - stability and dynamic behaviour of gas-liquid mass transfer accompanied by irreversible reaction

    NARCIS (Netherlands)

    Elk, E.P. van; Borman, P.C.; Kuipers, J.A.M.; Versteeg, G.F.

    1999-01-01

    The dynamic behaviour and stability of single-phase reacting systems has been investigated thoroughly in the past and design rules for stable operation are available from literature. The dynamic behaviour of gas-liquid processes is considerably more complex and has received relatively little

  4. Modelling of gas-liquid reactors - stability and dynamic behaviour of gas-liquid mass transfer accompanied by irreversible reaction

    NARCIS (Netherlands)

    Elk, van E.P.; Borman, P.C.; Kuipers, J.A.M.; Versteeg, G.F.

    1999-01-01

    The dynamic behaviour and stability of single-phase reacting systems has been investigated thoroughly in the past and design rules for stable operation are available from literature. The dynamic behaviour of gas–liquid processes is considerably more complex and has received relatively little

  5. Detection of different oxidation states of individual manganese porphyrins during their reaction with oxygen at a solid/liquid interface.

    Science.gov (United States)

    den Boer, Duncan; Li, Min; Habets, Thomas; Iavicoli, Patrizia; Rowan, Alan E; Nolte, Roeland J M; Speller, Sylvia; Amabilino, David B; De Feyter, Steven; Elemans, Johannes A A W

    2013-07-01

    Manganese porphyrins have been extensively investigated as model systems for the natural enzyme cytochrome P450 and as synthetic oxidation catalysts. Here, we report single-molecule studies of the multistep reaction of manganese porphyrins with molecular oxygen at a solid/liquid interface, using a scanning tunnelling microscope (STM) under environmental control. The high lateral resolution of the STM, in combination with its sensitivity to subtle differences in the electronic properties of molecules, allowed the detection of at least four distinct reaction species. Real-space and real-time imaging of reaction dynamics enabled the observation of active sites, immobile on the experimental timescale. Conversions between the different species could be tuned by the composition of the atmosphere (argon, air or oxygen) and the surface bias voltage. By means of extensive comparison of the results to those obtained by analogous solution-based chemistry, we assigned the observed species to the starting compound, reaction intermediates and products.

  6. Tuning the two-dimensional electron liquid at oxide interfaces by buffer-layer-engineered redox reactions

    DEFF Research Database (Denmark)

    Chen, Yunzhong; Green, Robert J.; Sutarto, Ronny

    2017-01-01

    Polar discontinuities and redox reactions provide alternative paths to create two-dimensional electron liquids (2DELs) at oxide interfaces. Herein, we report high mobility 2DELs at interfaces involving SrTiO3 (STO) achieved using polar La7/8Sr1/8MnO3 (LSMO) buffer layers to manipulate both...... polarities and redox reactions from disordered overlayers grown at room temperature. Using resonant x-ray reflectometry experiments, we quantify redox reactions from oxide overlayers on STO as well as polarity induced electronic reconstruction at epitaxial LSMO/STO interfaces. The analysis reveals how...... these effects can be combined in a STO/LSMO/disordered film trilayer system to yield high mobility modulation doped 2DELs, where the buffer layer undergoes a partial transformation from perovskite to brownmillerite structure. This uncovered interplay between polar discontinuities and redox reactions via buffer...

  7. Evaluation of reaction mechanisms and the kinetic parameters for the transesterification of castor oil by liquid enzymes

    DEFF Research Database (Denmark)

    Andrade, Thalles Allan; Errico, Massimiliano; Christensen, Knud Villy

    2017-01-01

    of the transesterification of castor oil with methanol using the enzyme Eversa® Transform as catalyst were investigated. Reactions were carried out for 8 hours at 35 °C with: an alcohol-to-oil molar ratio equal to 6:1, a 5 wt% of liquid enzyme solution and addition of 5 wt% of water by weight of castor oil. From...... methanolysis rates of glycerides obtained, indicated that transesterification dominates over hydrolysis. The mechanism among the four models proposed that gave the best fit could be simplified, eliminating the kinetic parameters with negligible effects on the reaction rates. This model was able to fit...

  8. Testing of a Liquid Oxygen/Liquid Methane Reaction Control Thruster in a New Altitude Rocket Engine Test Facility

    Science.gov (United States)

    Meyer, Michael L.; Arrington, Lynn A.; Kleinhenz, Julie E.; Marshall, William M.

    2012-01-01

    A relocated rocket engine test facility, the Altitude Combustion Stand (ACS), was activated in 2009 at the NASA Glenn Research Center. This facility has the capability to test with a variety of propellants and up to a thrust level of 2000 lbf (8.9 kN) with precise measurement of propellant conditions, propellant flow rates, thrust and altitude conditions. These measurements enable accurate determination of a thruster and/or nozzle s altitude performance for both technology development and flight qualification purposes. In addition the facility was designed to enable efficient test operations to control costs for technology and advanced development projects. A liquid oxygen-liquid methane technology development test program was conducted in the ACS from the fall of 2009 to the fall of 2010. Three test phases were conducted investigating different operational modes and in addition, the project required the complexity of controlling propellant inlet temperatures over an extremely wide range. Despite the challenges of a unique propellant (liquid methane) and wide operating conditions, the facility performed well and delivered up to 24 hot fire tests in a single test day. The resulting data validated the feasibility of utilizing this propellant combination for future deep space applications.

  9. Synthesis and characterization of an octaimidazolium-based polyhedral oligomeric silsesquioxanes ionic liquid by an ion-exchange reaction.

    Science.gov (United States)

    Tan, Jinglin; Ma, Depeng; Sun, Xingrong; Feng, Shengyu; Zhang, Changqiao

    2013-04-07

    Preparation of POSS-min-DS, an octaimidazolium-based polyhedral oligomeric silsesquioxanes (POSS) room temperature ionic liquid, by an ion-exchange reaction between POSS and sodium dodecyl sulfate was reported. Octaimidazolium-based POSS was synthesized with more than 98% yield within 3 h. POSS-min-DS and octaimidazolium-based POSS were confirmed by (1)H, (13)C, and (29)Si NMR, FT-IR and elemental analysis.

  10. Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction

    OpenAIRE

    Saed, Mohand O.; Torbati, Amir H.; Nair, Devatha P.; Yakacki, Christopher M.

    2016-01-01

    This study presents a novel two-stage thiol-acrylate Michael addition-photopolymerization (TAMAP) reaction to prepare main-chain liquid-crystalline elastomers (LCEs) with facile control over network structure and programming of an aligned monodomain. Tailored LCE networks were synthesized using routine mixing of commercially available starting materials and pouring monomer solutions into molds to cure. An initial polydomain LCE network is formed via a self-limiting thiol-acrylate Michael-addi...

  11. Dynamics of O(3P) Reactions with Gaseous Liquid and Solid Hydrocarbons

    National Research Council Canada - National Science Library

    Hase, William L

    2006-01-01

    ...) were applied to model reactions, including 0 + ethane and related reactions. In the second phase, a semiempirical quantum chemistry method, PM3-SRP, was developed by modifying and reparametrizing the standard PM3 method to fit the ab initio data...

  12. Studying the processes of sodium-water interaction in the BOR-60 reactor micromodule steam generator

    International Nuclear Information System (INIS)

    Tsykanov, V.A.; Antipin, G.K.; Borisov, V.V.

    1981-01-01

    Main results of experimental studies of emergency regimes of micromodule steam generator (MSG) at small and big leaks of water into sodium, realized using the 30 MW MSG, operating in the BOR-o0 reactor, are considered. The aims of the study are as follows: the modelling of macroleak in ''Nadja'' steam generator for the BN-350 reactor; testing the conceptions of alarm signalling and MSG protection; testing under real conditions of new perspective systems of leak detection; gaining the experimence and development of the ways to eliminate the consequences of accident caused by big water leak into sodium; accumulation of knowledge on restoration of MSG operating ability after accident; experimental test of calculational techniques for big leak accidents to use them in future for calculational studies of similar situations at other reactors equipped with sodium-water steam generators; refinement of characteristics of hydrodynamic and thermal effects interaction zone for big leak in real circuit during the plant operation. A series of experiments with the imitation of water leak into sodium by means of argon and steam supply through injection devices, located before the steam superheater module of one of the sections and between evaporator module of the same section, is conducted. The range of steam flow rate is 0.02-0.45 g/s. Duration of steam supply is 100-400 s. A conclusion is made that the results obtained can be used for steam generator of the BN-350 reactor [ru

  13. Pd-catalyzed ethylene methoxycarbonylation with Brønsted acid ionic liquids as promoter and phase-separable reaction media

    DEFF Research Database (Denmark)

    Garcia-Suarez, Eduardo J.; Khokarale, Santosh Govind; Nguyen van Buu, Olivier

    2014-01-01

    Brønsted acid ionic liquids (BAILs) were prepared and applied as combined acid promoters and reaction media in Pd–phosphine catalyzed methoxycarbonylation of ethylene to produce methyl propionate. The BAILs served as alternatives to common mineral acids required for the reaction, e.g. methanesulf......Brønsted acid ionic liquids (BAILs) were prepared and applied as combined acid promoters and reaction media in Pd–phosphine catalyzed methoxycarbonylation of ethylene to produce methyl propionate. The BAILs served as alternatives to common mineral acids required for the reaction, e...

  14. Imidazolium ionic liquids as solvents for cerium(IV)-mediated oxidation reactions

    OpenAIRE

    Mehdi, Hasan; Bodor, Andrea; Lantos, Diana; Horváth, István T; De Vos, Dirk; Binnemans, Koen

    2007-01-01

    Use of imidazolium ionic liquids as solvents for organic transformations with tetravalent cerium salts as oxidizing agents was evaluated. Good solubility was found for ammonium hexanitratocerate(IV) (ceric ammonium nitrate, CAN) and cerium(IV) triflate in 1-alkyl-3-methylimidazolium triflate ionic liquids. Oxidation of benzyl alcohol to benzaldehyde in 1-ethyl-3-methylimidazolium triflate was studied by in-situ FTIR spectroscopy and 13C NMR spectroscopy on carbon-13-labeled benzyl alcohol. Ca...

  15. Electrode reactions of ruthenium–bipyridine complex in amide-type ionic liquids

    International Nuclear Information System (INIS)

    Toshimitsu, Yuichi; Katayama, Yasushi; Miura, Takashi

    2012-01-01

    The electrode kinetics of [Ru(bpy) 3 ] 3+ /[Ru(bpy) 3 ] 2+ (bpy = 2,2′-bipyridine) on a platinum electrode was investigated in room-temperature ionic liquids, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (EMITFSA), and 1-butyl-1-methylpyrrolidinium bis(perfluoroethylsulfonyl)amide (BMPBETA) over the temperature range from 25 to 45 °C. The diffusion coefficients of [Ru(bpy) 3 ] 2+ and [Ru(bpy) 3 ] 3+ were found to be affected not only by the viscosity of ionic liquids but also by the charge density of the complex. The activation energy for the diffusion coefficients of these complexes in the ionic liquids were close to that for the viscosity of the ionic liquids. The standard rate constants of [Ru(bpy) 3 ] 3+ /[Ru(bpy) 3 ] 2+ in BMPTFSA, EMITFSA and BMPBETA were estimated by electrochemical impedance spectroscopy. The standard rate constants in the ionic liquids were estimated to be smaller than those in aqueous and organic electrolytes, probably due to the slow dynamics of the ionic liquids.

  16. Study of hydrogen consumption reaction catalyzed by Pd ions in the simulated high-level liquid waste

    International Nuclear Information System (INIS)

    Kodama, Takashi

    2013-01-01

    To ensure the safety for storage of high-level liquid waste (HLLW) in tanks is one of the most important safety issues in a reprocessing plant since almost all radioactive materials under processing are collected in these tanks. Accordingly the behavior of radiolytically formed hydrogen (H 2 ) in these tanks is one of key issues and has been studied by several researchers because it might cause an explosion. They reported that not all of H 2 formed in HLLW comes out in the gas phase because H 2 is consumed by some un-clarified secondary reaction which may be caused by the irradiation and/or by the catalytic effect of certain fission product (FP) in HLLW. In order to clarify such effect, we carried out the experiments using the simulated high level liquid waste (SHLLW) with and without palladium (Pd) group ions under irradiation and non-irradiation conditions. As a result, it was found that H 2 consumption reaction is not caused by radiation as was understood so far but is caused by a catalytic effect of Pd ion in SHLLW. That is, H 2 is reacting with HNO 3 and forming H 2 O and NOx. Using the catalytic reaction rate constant measured in the experiments, the analysis showed that the H 2 concentration in the gas phase of an HLLW tank does not reach its explosion limit of 4% even if the sweeping air stops for a long time. (authors)

  17. Liquid-liquid transfer phenomena studies coupled with redox reactions: back-extraction of nitrous acid in the presence of scavengers in aqueous phase

    International Nuclear Information System (INIS)

    K'zerho, R.

    1998-01-01

    This work deals with the investigation of redox reaction contribution to the kinetics of liquid-liquid transfer, in relation with PUREX reprocessing of spent nuclear fuel. The chemical system chosen concerns the tripping of nitrous acid from tributylphosphate organic phase into a nitric acid aqueous solution containing an 'anti-nitrous' component, namely hydrazinium nitrate. According to the abundant literature, a major attention is devoted to the very important role of interfacial phenomena on the kinetics of solvent extraction with tributylphosphate. Although, a suitable experimental technique is chosen, using a constant interfacial area cell of the ARMOLLEX-type. Furthermore, the effects of the hydrodynamical and the physico-chemical parameters on the extraction rate led to the identification of the extraction regime nature: diffusional, then chemical limitation. When no 'anti-nitrous' component is used, the diffusional resistance is found to be mainly located in the aqueous diffusion layer. The presence of hydrazinium nitrate into the aqueous solution has an overall accelerating effect on the rate of extraction, related to both a complete suppression of the aqueous diffusional resistance, and a very significant enhancement of the interfacial transfer of the nitrous acid, as a function of hydrazinium concentration. If the first effect could be expected because of the well known fast redox reaction in aqueous phase, the second phenomenon represents a quite original and new result which has never been explored before, to the best of our knowledge. A reaction mechanism is postulated and validated, taking into account the reactive effect of hydrazinium on the interfacial step. In order to support the drawn general patterns, different complementary studies were attempted. When hydroxyl-ammonium nitrate is used, a surprising interfacial transfer blockage is observed, pointing out the extreme performance and specificity of the common hydrazinium component. (author)

  18. Reaction

    African Journals Online (AJOL)

    abp

    19 oct. 2017 ... Reaction to Mohamed Said Nakhli et al. concerning the article: "When the axillary block remains the only alternative in a 5 year old child". .... Bertini L1, Savoia G, De Nicola A, Ivani G, Gravino E, Albani A et al ... 2010;7(2):101-.

  19. A Voltammetric Determination of the Rate Constant of a One-Way Homogeneous Chemical Reaction in a System of Two Immiscible Liquid Phases

    Czech Academy of Sciences Publication Activity Database

    Holub, Karel; Brusová, Zuzana; Štulík, K.; Mareček, Vladimír

    2004-01-01

    Roč. 574, č. 1 (2004), s. 101-106 ISSN 0022-0728 R&D Projects: GA ČR GA203/03/0822 Institutional research plan: CEZ:AV0Z4040901 Keywords : liquid|liquid interfaces * homogeneous reaction * voltammetry Subject RIV: CG - Electrochemistry Impact factor: 2.228, year: 2004

  20. Multifilamentary superconducting (NbTa)-Sn composite wire by solid-liquid reaction for possible application above 20 tesla

    International Nuclear Information System (INIS)

    Hong, M.; Hull, G.W. Jr.; Fuchs, E.O.; Holthuis, J.T.

    1983-01-01

    Nb alloyed with Ta was employed in fabricating multifilamentary composite wires of (NbTa)-Sn using the liquid-infiltration process. The superconducting A15 phase was formed with subsequent heat treatments at 800-950 0 C by the solid-liquid reaction. High inductive Tsub(c)'s of 18.2 K with sharp transition width ( 4 A/cm 2 at 2O T and 4.2 K were obtained. It was found that 2 wt.% Ta in the Nb was sufficient in the enhancement of the overall Jsub(c) at the high fields and in increasing the Hsub(c2) (4.2 K) to 25 T. (Auth.)

  1. Multifilamentary superconducting (NbTa)-Sn composite wire by solid-liquid reaction for possible application above 20 tesla

    International Nuclear Information System (INIS)

    Hong, M.; Hull, G.W. Jr.; Fuchs, E.O.; Holthuis, J.T.

    1983-01-01

    Nb alloyed with Ta was employed in fabricating multifilamentary composite wires of (NbTa)-Sn using the liquid-infiltration process. The superconducting A15 phase was formed with subsequent heat treatments at 800-950 0 C by the solid-liquid reaction. High inductive Tsub(c)'s of 18.2 K with sharp transition width ( 4 A/cm 2 at 20 T and 4.2 K were obtained. It was found that 2 wt.% Ta in the Nb was sufficient in the enhancement of the overall Jsub(c) at the high fields and in increasing the Hsub(c2) (4.2 K) to 25 T. (orig.)

  2. Study on sodium water glass-based anti-reflective film and its application in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Q.Z. [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Shi, J.F., E-mail: shijf@ms.giec.ac.cn [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China); Wang, L.L.; Li, Y.J.; Zhong, L.W. [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China); Xu, G., E-mail: xugang@ms.giec.ac.cn [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China)

    2016-07-01

    In this paper, anti-reflective (AR) films are prepared from sodium water glass with a simple dip-coating method. The effects of SiO{sub 2}/Na{sub 2}O molar ratio, concentration of water glass, and withdrawal speed on the anti-reflection performance of the AR films are systematically studied. The optimized AR film is further applied in dye-sensitized solar cells (DSCs). The optical properties and surface morphology of AR films are analyzed by ultraviolet-visible spectrophotometer, scanning electron microscope, and atomic force microscope. Transmittance of the glass coated with sodium water glass-based AR film is increased by 3.2% when the SiO{sub 2}/Na{sub 2}O molar ratio, concentration, and withdrawal speed equal to 3.8, 5 wt%, and 80 mm/min, respectively. Under this condition, the thickness of the AR film is 127 nm and the AR film has obvious porous structure. In addition, the power conversion efficiency of DSC coated by AR film is increased from 7.92% to 8.24%, compared with the DSC without AR film. - Highlights: • Anti-reflective films are prepared from sodium water glass. • Transmittance of anti-reflective film is increased by 3.2%. • Efficiency of dye-sensitized cell is improved by anti-reflective film.

  3. Study on sodium water glass-based anti-reflective film and its application in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Huang, Q.Z.; Shi, J.F.; Wang, L.L.; Li, Y.J.; Zhong, L.W.; Xu, G.

    2016-01-01

    In this paper, anti-reflective (AR) films are prepared from sodium water glass with a simple dip-coating method. The effects of SiO_2/Na_2O molar ratio, concentration of water glass, and withdrawal speed on the anti-reflection performance of the AR films are systematically studied. The optimized AR film is further applied in dye-sensitized solar cells (DSCs). The optical properties and surface morphology of AR films are analyzed by ultraviolet-visible spectrophotometer, scanning electron microscope, and atomic force microscope. Transmittance of the glass coated with sodium water glass-based AR film is increased by 3.2% when the SiO_2/Na_2O molar ratio, concentration, and withdrawal speed equal to 3.8, 5 wt%, and 80 mm/min, respectively. Under this condition, the thickness of the AR film is 127 nm and the AR film has obvious porous structure. In addition, the power conversion efficiency of DSC coated by AR film is increased from 7.92% to 8.24%, compared with the DSC without AR film. - Highlights: • Anti-reflective films are prepared from sodium water glass. • Transmittance of anti-reflective film is increased by 3.2%. • Efficiency of dye-sensitized cell is improved by anti-reflective film.

  4. Lipase-catalyzed glycerolysis of fats and oils in ionic liquids: a further study on the reaction system

    DEFF Research Database (Denmark)

    Guo, Zheng; Xu, Xuebing

    2006-01-01

    Candida antarctica lipase B-catalyzed glycerolysis of sunflower oil in a tetraammonium-based ionic liquid (IL) was studied to elucidate its distinct characteristics and to evaluate the contributions of important parameters. Mass transfer limitations and occurring partial phase separation were found...... and enzyme loading study. Interestingly, increasing water activity resulted in a decreasing initial reaction rate and a prolonged induction period, which possibly resulted from an elevated solvation barrier and the phase separation at higher water content. Studies on thermodynamics of glycerolysis show......) equation, and the viscosity of the mixture is strongly agitation-dependent. A comparable diffusion time constant of the oil molecule in the IL to that of the reaction shows that the glycerolysis in the IL is controlled both diffusionally and kinetically, as experimentally verified by agitation effect...

  5. Modified reaction mechanism of aerated n-dodecane liquid flowing over heated metal tubes

    Science.gov (United States)

    Reddy, K. T.; Cernansky, N. P.; Cohen, R. S.

    1988-01-01

    The degradation mechanism of the n-dodecane was studied using a modified jet fuel thermal oxidation tester containing a sample withdrawal system as a reaction vessel. The reaction products were identified using gas chromatography and mass spectorometry. The soluble products were found to consist mainly of C5-C10 n-alkanes and 1-alkenes, C7-C10 aldehydes, tetrahydrofuran derivatives, dodecanol and dodecanone isomers, dodecyl hydroperoxide (ROOH) decomposition products, and C24 alkane isomers. The data from the experiments agreed with those of Hazlett et al. (1977). It was found that alkyl peroxide radical reactions dominate in the autooxidation temperature regime (at T not above 300 C); the dominant path is for the alkyl peroxyl radical to react bimolecularly with fuel to yield primarily alkyl hydroperoxides. The alkyl peroxide radical also undergoes self-termination and unimolecular isomerization and decomposition reactions, to yield smaller amounts of C12 alcohol plus ketone products and tetrahydrofuran derivatives, respectively.

  6. Laser-enhanced chemical reactions and the liquid state. II. Possible applications to nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    DePoorter, G.L.; Rofer-DePoorter, C.K.

    1976-01-01

    Laser photochemistry is surveyed as a possible improvement upon the Purex process for reprocessing spent nuclear fuel. Most of the components of spent nuclear fuel are photochemically active, and lasers can be used to selectively excite individual chemical species. The great variety of chemical species present and the degree of separation that must be achieved present difficulties in reprocessing. Lasers may be able to improve the necessary separations by photochemical reaction or effects on rates and equilibria of reactions

  7. Isotope Fractionation in Methane Reactions Studied by Gas Chromatography and Liquid Scintillation

    DEFF Research Database (Denmark)

    Andersen, Bertel Lohmann; Bidoglio, G.; Leip, A.

    1997-01-01

    Determination of C-14-marked methane by gas chromatography and liquid scintillation counting is shown to be useful in studies of isotope effects. Data on the specific activity is used to separate the contributions of (CH4)-C-14, and (CH4)-C-12 to the gas-chromatographic peak area. As an application...

  8. Multicomponent Reaction in Ionic Liquid: A Novel and Green Synthesis of 1, 4-Dihydropyridine Derivatives

    Institute of Scientific and Technical Information of China (English)

    Xin Ying ZHANG; Yan Zhen LI; Xue Sen FAN; Gui Rong QU; Xue Yuan HU; Jian Ji WANG

    2006-01-01

    An efficient and green method for the synthesis of 1, 4-dihydropyridine derivatives mediated in an ionic liquid, [bmim][BF4], through a four-component condensation process of aldehydes, 1, 3-dione, Meldrum's acid and ammonium acetate is disclosed in this paper.

  9. Characterisation and application of the Fe(II)/Fe(III) redox reaction in an ionic liquid analogue

    International Nuclear Information System (INIS)

    Lloyd, David; Vainikka, Tuomas; Ronkainen, Markus; Kontturi, Kyösti

    2013-01-01

    Highlights: • The Fe(II)/Fe(III) reaction is shown to be facile using a wall-jet electrode and RDE. • Deposition/stripping of iron has equally slow kinetics as in aqueous systems. • An IL based all-iron RFB is reported for the first time, energy efficiency is 37%. • An Zn–Fe complex is shown to form. In an RFB this gives an energy efficiency of 78%. • Problems resulting from the use of redox probes and urea-based DES are demonstrated. -- Abstract: In this paper we report the properties of the Fe(II)/Fe(III) reaction in a deep eutectic solvent based on choline chloride and ethylene glycol. This reaction is shown to be facile using a wall-jet electrode and rotating disc electrode. The deposition and stripping of iron exhibits equally slow kinetics as in aqueous systems. Using these two reactions an all-iron redox flow battery based on ionic liquids is reported for the first time. An energy efficiency of 37% is attained at a current density of 0.5 mA cm −2 . A Zn(II)–Fe(II) complex is shown to form when zinc is oxidized by Fe(III). When this complex is applied in a redox flow battery energy efficiencies of 78% are achieved at a current density of 0.5 mA cm −2

  10. Utilizing ultrathin DNA/poly-lysine multilayer films to create liquid/liquid interfaces: spectroscopic characterization, interfacial reactions and nanoparticle adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hye Jin; Wark, Alastair W; Corn, Robert M [Department of Chemistry, University of California-Irvine, Irvine, CA 92697 (United States)

    2007-09-19

    Alternating electrostatic multilayer adsorption of poly-L-lysine (pLys) and DNA is used to create well-defined biopolymer multilayers for use as an ultrathin aqueous phase in liquid-liquid interfacial measurements. The molecular structure and thickness of the polyelectrolyte multilayers are determined using a combination of polarization modulation FT-IR reflection-absorption spectroscopy (PM-FTIRRAS) and FT-surface plasmon resonance (FT-SPR) thickness measurements. Electroactive species such as ferri/ferrocyanide ions can be incorporated into the DNA/pLys polyelectrolyte multilayers. The ion transport activity of these electroactive films when in contact with 1,2-dichoroethane is verified by electrochemical measurements. Micron-sized patterns of these multilayers are created by either photopatterning, vapour-deposited spot patterning or microfluidic stencil processing, and are used in conjunction with fluorescence and surface plasmon resonance imaging (SPRI) to monitor (i) the intercalation of dye molecules into DNA/pLys ultrathin films, (ii) the electrostatic adsorption of gold nanoparticles onto DNA/pLys multilayers and (iii) the spatially controlled incorporation and reaction of enzymes into patterned biopolymer multilayers.

  11. Ionic-liquid-induced microfluidic reaction for water-soluble Ce1-xTbxF3 nanocrystal synthesis

    International Nuclear Information System (INIS)

    Xie Nan; Luan Weiling

    2011-01-01

    Luminescent lanthanide nanocrystals (NCs) are proposed to be a promising new class of fluorescent labeling agents due to their attractive optical and chemical features including low toxicity, wide photoluminescence (PL) emission and high resistance to photobleaching. In this paper, an ionic-liquid-induced synthesis of Ce 1-x Tb x F 3 nanoparticle was investigated via utilizing a capillary microreactor. Ionic liquid-[bmim]BF 4 acts as both a fluoride source and stabilizing solvent during the reaction, which was shown to be a key factor that governs luminescence intensity of the obtained nanoparticles. The luminescent properties can be greatly improved by optimizing the volume percentage of [bmim]BF 4 . Furthermore, the reaction temperature exerts an influence on the properties of the prepared samples. Experimental results show that the colloidal solutions of Tb 3+ -doped CeF 3 NCs exhibit the characteristic emission of Ce 3+ 5d-4f and Tb 3+5 D 4 - 7 F J (J = 6-3) transitions with 5 D 4 - 7 F 5 green emission at 542 nm as the strongest peak. The as-prepared samples are found dispersible in water with the quantum yield (in aqueous solution) as 12%, which indicates a potential application on biolabels, light-emitting diodes (LEDs) and redox luminescent switches.

  12. Reaction of hydroxyl radicals with ammonia in liquid water at elevated temperatures

    DEFF Research Database (Denmark)

    Hickel, B.; Sehested, K.

    1992-01-01

    The reaction of hydroxyl radical with ammonia in aqueous solutions has been studied by pulse radiolysis in the temperature range 20-200-degrees-C. The rate constant of the reaction was determined by monitoring the decay of the OH radical absorption at 260 nm for different concentrations of ammonia....... At room temperature the rate constant is (9.7 +/- 1) x 10(7) dm3 mol-1 s-1. In the whole range of temperatures the Tate constant follows Arrhenius law with an activation energy of (5.7 +/- 1) kJ mol-1. The protective effect of dissolved hydrogen on the radiolytic decomposition of ammon a is discussed....

  13. Intensification of the Use of Ionic Liquids as Efficient Reaction Co-Solvents in Asymmetric Hydrogenations

    Czech Academy of Sciences Publication Activity Database

    Černá, I.; Klusoň, Petr; Bendová, Magdalena; Floriš, Tomáš; Pelantová, Helena; Pekárek, T.

    2011-01-01

    Roč. 50, č. 3 (2011), s. 264-272 ISSN 0255-2701 R&D Projects: GA AV ČR KAN400720701; GA AV ČR IAA400720710 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z50200510 Keywords : Ionic liquids * asymmetric hydrogenations * BmimPF6 Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.924, year: 2011

  14. Sustainable ways of combining reactions and separations using ionic liquids and carbon dioxide

    NARCIS (Netherlands)

    Kazemi, S.

    2013-01-01

    Traditional chemical processes show shortcomings caused by using volatile organic compounds as solvents during reactions and separations. Therefore, it is necessary to address this issue by moving toward more environmentally friendly processes. This is possible by using less toxic and hazardous

  15. Sustainable Ways of Combining Reactions and Separations Using Ionic Liquids and Carbon Dioxide

    NARCIS (Netherlands)

    Kazemi, S.

    2013-01-01

    Traditional chemical processes show shortcomings caused by using volatile organic compounds as solvents during reactions and separations. Therefore, it is necessary to address this issue by moving toward more environmentally friendly processes. This is possible by using less toxic and hazardous

  16. RUTHENIUM-CATALYZED TANDEM OLEFIN MIGRATION-ALDOL AND MANNICH-TYPE REACTIONS IN IONIC LIQUID.

    Science.gov (United States)

    In the presence of a catalytic amount of RuCl2(PPh3)3, a cross-coupling of 3-buten-2-ol with aldehydes and imines was developed via a tandem olefin migration--aldol--Mannich reaction in bmim[PF6]. With In(OAc)3 as a co-catalyst, a-vinylbenzyl alcohol and aldehydes underwent sim...

  17. Computational studies of atmospherically-relevant chemical reactions in water clusters and on liquid water and ice surfaces.

    Science.gov (United States)

    Gerber, R Benny; Varner, Mychel E; Hammerich, Audrey D; Riikonen, Sampsa; Murdachaew, Garold; Shemesh, Dorit; Finlayson-Pitts, Barbara J

    2015-02-17

    CONSPECTUS: Reactions on water and ice surfaces and in other aqueous media are ubiquitous in the atmosphere, but the microscopic mechanisms of most of these processes are as yet unknown. This Account examines recent progress in atomistic simulations of such reactions and the insights provided into mechanisms and interpretation of experiments. Illustrative examples are discussed. The main computational approaches employed are classical trajectory simulations using interaction potentials derived from quantum chemical methods. This comprises both ab initio molecular dynamics (AIMD) and semiempirical molecular dynamics (SEMD), the latter referring to semiempirical quantum chemical methods. Presented examples are as follows: (i) Reaction of the (NO(+))(NO3(-)) ion pair with a water cluster to produce the atmospherically important HONO and HNO3. The simulations show that a cluster with four water molecules describes the reaction. This provides a hydrogen-bonding network supporting the transition state. The reaction is triggered by thermal structural fluctuations, and ultrafast changes in atomic partial charges play a key role. This is an example where a reaction in a small cluster can provide a model for a corresponding bulk process. The results support the proposed mechanism for production of HONO by hydrolysis of NO2 (N2O4). (ii) The reactions of gaseous HCl with N2O4 and N2O5 on liquid water surfaces. Ionization of HCl at the water/air interface is followed by nucleophilic attack of Cl(-) on N2O4 or N2O5. Both reactions proceed by an SN2 mechanism. The products are ClNO and ClNO2, precursors of atmospheric atomic chlorine. Because this mechanism cannot result from a cluster too small for HCl ionization, an extended water film model was simulated. The results explain ClNO formation experiments. Predicted ClNO2 formation is less efficient. (iii) Ionization of acids at ice surfaces. No ionization is found on ideal crystalline surfaces, but the process is efficient on

  18. Ultrafast infrared studies of chemical reaction dynamics in room-temperature liquids

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Haw [Univ. of California, Berkeley, CA (United States)

    1999-11-01

    Femtosecond infrared spectroscopy provides sufficient spectral and temporal resolution to support a detailed investigation of the early events of a photochemical reaction. Previously unreported transient species that arise as intermediates during the course of a reaction may have lifetimes that are too short for conventional characterization. For these species, quantum-mechanical (density functional theoretical and ab initio) electronic structure calculations provide invaluable insight into chemical properties including molecular structure and energetic. With the combination of experimental and theoretical results, it is possible to assemble a comprehensive picture of the reaction dynamics of a system that is intricately influenced by the surrounding solvent molecules. The mechanisms of several important organometallic reactions, such as alkane C– H bond activation by η3-Tp*Rh(CO), silane Si–H bond activation by η5-CpMn(CO)2 and η5-CpRe(CO)2, as well as chlorinated methane C–Cl bond cleavage by the Re(CO)5 radical are elucidated. The results demonstrate the importance of molecular morphology change (C–H and Si–H act ivat ion), solvent rearrangement (Si–H activation), intersystem crossing (Si–H activation), and solvent caging (C–Cl cleavage) in understanding the reactivity of the organometallic species, The nature of the apparent free-energy barrier for C–H, Si–H, and C–Cl bond activation reaction is found to be- cleavage of an alkane C–H bond, rearrangement of a silane molecule HSiR3 (R = alkyl group) from a nonreactive alkyl site to the reactive Si–H bond, and Cl atom transfer from a chlorinated methane molecule to Re(CO)5, respectively. These results support previous d initio calculations for C–H and Si–H bond activation reaction profiles which suggest that cleavage of an alkane C–H bond by a transition metal center, unlike that of a silane

  19. Reactions of Ions with Ionic Liquid Vapors by Selected-Ion Flow Tube Mass Spectrometry

    Science.gov (United States)

    2011-03-29

    Emel’yanenko, V. N.; Verevkin, S. P.; Heintz, A.; Corfield, J.-A.; Deyko, A.; Lovelock , K. R. J.; Licence, P.; Jones, R. G. Pyrrolidinium- Based Ionic...112, 11734–11742. (2) Lovelock , K. R. J.; Deyko, A.; Licence, P.; Jones, R. G. Vaporisa- tion of an Ionic Liquid Near Room Temperature. Phys. Chem...Relevance of pKa from Aqueous Solutions. J. Am. Chem. Soc. 2003, 125, 15411–15419. (15) Armstrong, J. P.; Hurst, C.; Jones, R. G.; Licence, P.; Lovelock , K

  20. Electrodeposition of Amorphous Molybdenum Chalcogenides from Ionic Liquids and Their Activity for the Hydrogen Evolution Reaction.

    Science.gov (United States)

    Redman, Daniel W; Rose, Michael J; Stevenson, Keith J

    2017-09-19

    This work reports on the general electrodeposition mechanism of tetrachalcogenmetallates from 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. Both tetrathio- and tetraselenomolybdate underwent anodic electrodeposition and cathodic corrosion reactions as determined by UV-vis spectroelectrochemistry. Electrodeposition was carried out by cycling the potential between the anodic and cathodic regimes. This resulted in a film of densely packed nanoparticles of amorphous MoS x or MoSe x as determined by SEM, Raman, and XPS. The films were shown to have high activity for the hydrogen evolution reaction. The onset potential (J = 1 mA/cm 2 ) of the MoS x film was E = -0.208 V vs RHE, and that of MoSe x was E = -0.230 V vs RHE. The Tafel slope of MoS x was 42 mV/decade, and that of MoSe x was 59 mV/decade.

  1. On the method of heat exchange calculation for critical and postcritical regimes in sodium-water steam generators

    International Nuclear Information System (INIS)

    Khudasko, V.V.; Kardash, D.Yu.; Grachev, N.S.

    1986-01-01

    Technique for calculating heat exchange in sodium-water steam generators with provisions for steam-water flow non-equilibrium character and moisture additional evaporation in pipes is suggested. Zone of heat exchange crisis representing the zone of transition from developed boiling to postcritical zone is considered. Comparison of estimated and experimental data performed for the following ranges of steame generator parameters: pressure p=7.8-14.0 MPa, coolant flow rate ρw=350-1000 kg/(m 2 xs), inlet sodium temperature T=590-825 K shows their good agreement

  2. Interparticle potential of 10 nanometer titanium nanoparticles in liquid sodium: Theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soo Jae; Park, Gun Yeop; Park, Hyun Sun; Baek, Je Hyun [POSTECH, Pohang (Korea, Republic of); Kim, Moo Hwan [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    A suspension of titanium nanoparticles (Ti NPs) in liquid sodium (Na) has been proposed as a method to mitigate the violent sodium-water reaction (SWR). The interparticle potential between Ti NPs in liquid Na may play a significant role in the agglomeration of NPs on the reaction surface and in the bulk liquid Na, since the potential contributes to a reduction in the long-term dispersion stability. For the effective control of the SWR with NPs, a physical understanding of the molecular dynamics of NPs in liquid Na is key. Therefore in this study, the nonretarded Van der Waals model and the solvation potential model are employed to analyze the interparticle potential. The ab initio calculation reveals that a strong repulsive force driven by the solvation potential exceeds the interparticle attraction and predicts the agglomeration energy required for two 10-nm Ti NPs to be 4 x 10{sup -17} J. The collision theory suggests that Ti NPs can be effective suppressors of the SWR due to the high energy barrier that prevents significant agglomeration of Ti NPs in quiescent liquid Na.

  3. LC-MS/MS analysis of uncommon paracetamol metabolites derived through in vitro polymerization and nitration reactions in liquid nitrogen.

    Science.gov (United States)

    Trettin, Arne; Jordan, Jens; Tsikas, Dimitrios

    2014-09-01

    Paracetamol (acetaminophen, APAP) is a commonly used analgesic drug. Known paracetamol metabolites include the glucuronide, sulfate and mercapturate. N-Acetyl-benzoquinonimine (NAPQI) is considered the toxic intermediate metabolite of paracetamol. In vitro and in vivo studies indicate that paracetamol is also metabolized to additional poorly characterized metabolites. For example, metabolomic studies in urine samples of APAP-treated mice revealed metabolites such as APAP-sulfate-APAP and APAP-S-S-APAP in addition to the classical phase II metabolites. Here, we report on the development and application of LC-MS and LC-MS/MS approaches to study reactions of unlabelled and (2)H-labelled APAP with unlabelled and (15)N-labelled nitrite in aqueous phosphate buffers (pH 7.4) upon their immersion into liquid nitrogen (-196°C). In mechanistic studies, these reactions were also studied in aqueous buffer prepared in (18)O-labelled water. LC-MS and LC-MS/MS analyses were performed on a reverse-phase material (C18) using gradient elution (2mM ammonium acetate/acetonitrile), in positive and negative electrospray mode. We identified a series of APAP metabolites including di-, tri- and tetra-APAP, mono- and di-nitro-APAP and nitric ester of di-APAP. Our study indicates that nitrite induces oxidation, i.e., polymerization and nitration of APAP, when buffered APAP/nitrite solutions are immersed into liquid nitrogen. These reactions are specific for nitrite with respect to nitrate and do not proceed via intermediate formation of NAPQI. Potassium ions and physiological saline but not thiols inhibit nitrite- and shock-freeze-induced reactions of paracetamol. The underlying mechanism likely involves in situ formation of NO2 radicals from nitrite secondary to profound pH reduction (down to pH 1) and disproportionation. Polymeric paracetamol species can be analyzed as pentafluorobenzyl derivatives by LC-MS but not by GC-MS. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Positron Spur Reactions with Excess Electrons and Anions in Liquid Organic Mixtures of Electron Acceptors

    DEFF Research Database (Denmark)

    Lévay, B.; Mogensen, O. E.

    1980-01-01

    By means of the positron lifetime technique we have measured positronium (Ps) yields in mixtures of nonpolar liquids with various electron scavengers which bind the electron fairly weakly (1–2 eV) in stable anions. The results are discussed with reference to recent excess electron works, and new...... experiments on anions and excess electrons are proposed. The minimum of the Ps yield versus CS2 concentration curves caused by partly delocalization of electrons on several scavenger molecules, which was observed previously in saturated aliphatic hydrocarbons occurred also in the saturated cyclic hydrocarbon...... cyclohexane, but did not appear in the aromatic benzene. This might be explained by the weak electron acceptor property of aromatics. In the Ps yield versus SF6 concentration curve in hexane a similar minimum appeared as in the CS2 case, probably by the same reason. By adding 0.8 M CS2 to the system...

  5. IDENTIFICATION OF MYCOBACTERIUM GENAVENSE IN A DIANA MONKEY (CERCOPITHECUS DIANA) BY POLYMERASE CHAIN REACTION AND HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY.

    Science.gov (United States)

    Kelly, Kathleen M; Wack, Allison N; Bradway, Dan; Simons, Brian W; Bronson, Ellen; Osterhout, Gerard; Parrish, Nicole M; Montali, Richard J

    2015-06-01

    A 25-yr-old Diana monkey (Cercopithecus diana) with a 1.5-yr history of chronic colitis and diarrhea was found to have disseminated granulomatous disease with intralesional acid fast bacilli. Bacilli were identified as Mycobacterium genavense by polymerase chain reaction, sequencing of the 16S-23S ribosomal RNA intergenic spacer (ITS) gene, and mycolic acid analysis by high-performance liquid chromatography. Mycobacterium genavense is a common cause of mycobacteriosis in free-ranging and captive birds. In addition, recognition of opportunistic infection in human immunodeficiency virus-positive patients is increasing. Disease manifestations of M. genavense are similar to Mycobacterium avium complex (MAC) and include fever, wasting, and diarrhea with disseminated disease. Similar clinical signs and lesions were observed in this monkey. Mycobacterium genavense should be considered as a differential for disseminated mycobacterial disease in nonhuman primates as this agent can mimic MAC and related mycobacteria.

  6. SERS- and Electrochemically Active 3D Plasmonic Liquid Marbles for Molecular-Level Spectroelectrochemical Investigation of Microliter Reactions.

    Science.gov (United States)

    Koh, Charlynn Sher Lin; Lee, Hiang Kwee; Phan-Quang, Gia Chuong; Han, Xuemei; Lee, Mian Rong; Yang, Zhe; Ling, Xing Yi

    2017-07-17

    Liquid marbles are emergent microreactors owing to their isolated environment and the flexibility of materials used. Plasmonic liquid marbles (PLMs) are demonstrated as the smallest spectroelectrochemical microliter-scale reactor for concurrent spectro- and electrochemical analyses. The three-dimensional Ag shell of PLMs are exploited as a bifunctional surface-enhanced Raman scattering (SERS) platform and working electrode for redox process modulation. The combination of SERS and electrochemistry (EC) capabilities enables in situ molecular read-out of transient electrochemical species, and elucidate the potential-dependent and multi-step reaction dynamics. The 3D configuration of our PLM-based EC-SERS system exhibits 2-fold and 10-fold superior electrochemical and SERS performance than conventional 2D platforms. The rich molecular-level electrochemical insights and excellent EC-SERS capabilities offered by our 3D spectroelectrochemical system are pertinent in charge transfer processes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Alginate as immobilization matrix and stabilizing agent in a two-phase liquid system: application in lipase-catalysed reactions.

    Science.gov (United States)

    Hertzberg, S; Kvittingen, L; Anthonsen, T; Skjåk-Braek, G

    1992-01-01

    Alginate was evaluated as an immobilization matrix for enzyme-catalyzed reactions in organic solvents. In contrast to most hydrogels, calcium alginate was found to be stable in a range of organic solvents and to retain the enzyme inside the gel matrix. In hydrophobic solvents, the alginate gel (greater than 95% water) thus provided a stable, two-phase liquid system. The lipase from Candida cylindracea, after immobilization in alginate beads, catalysed esterification and transesterification in n-hexane under both batch and continuous-flow conditions. The operational stability of the lipase was markedly enhanced by alginate entrapment. In the esterification of butanoic acid with n-butanol, better results were obtained in the typical hydrophilic calcium alginate beads than in less hydrophilic matrices. The effects of substrate concentration, matrix area, and polarity of the substrate alcohols and of the organic solvent on the esterification activity were examined. The transesterification of octyl 2-bromopropanoate with ethanol was less efficient than that of ethyl 2-bromopropanoate with octanol. By using the hydrophilic alginate gel as an immobilization matrix in combination with a mobile hydrophobic phase, a two-phase liquid system was achieved with definite advantages for a continuous, enzyme-catalysed process.

  8. Radiative flow of Carreau liquid in presence of Newtonian heating and chemical reaction

    Science.gov (United States)

    Hayat, T.; Ullah, Ikram; Ahmad, B.; Alsaedi, A.

    Objective of this article is to investigate the magnetohydrodynamic (MHD) boundary layer stretched flow of Carreau fluid in the presence of Newtonian heating. Sheet is presumed permeable. Analysis is studied in the presence of chemical reaction and thermal radiation. Mathematical formulation is established by using the boundary layer approximations. The resultant nonlinear flow analysis is computed for the convergent solutions. Interval of convergence via numerical data and plots are obtained and verified. Impact of numerous pertinent variables on the velocity, temperature and concentration is outlined. Numerical data for surface drag coefficient, surface heat transfer (local Nusselt number) and mass transfer (local Sherwood number) is executed and inspected. Comparison of skin friction coefficient in limiting case is made for the verification of current derived solutions.

  9. Theoretical study on platinum-catalyzed isotope exchange reaction mechanism of hydrogen and liquid water

    International Nuclear Information System (INIS)

    Hu Sheng; Wang Heyi; Luo Shunzhong

    2009-04-01

    Based on electron and vibration approximate means and the density function theory B3LYP, the ΔG degree and equilibrium pressures of adsorption and dissociation reactions of H 2 and water vapor on Pt surface have been calculated. The adsorption, dissociation and coadsorption actions of H 2 and water were analyzed. According to the ΔG degree, hydrogen molecule combines with metal atoms in single atom, and water vapor molecule has no tendency to dissociate on Pt surface. The dissociation of hydrogen molecule would hold back the direct adsorption of water vapor molecules on Pt surface. The structures of Pt-H (OH 2 ) n + (n=1, 2, 3) hydroniums were optimized. According to the mulliken overlap populations, Pt-H (OH 2 ) + is not stable or produced. Hydrogen isotope exchange occurs between hydration layer and D atoms which adsorb on Pt surface via intermediates (H 2 O) n D + (ads) (n≥2). (authors)

  10. Metal nanoparticles/ionic liquid/cellulose: polymeric membrane for hydrogenation reactions

    Directory of Open Access Journals (Sweden)

    Marcos Alexandre Gelesky

    2014-01-01

    Full Text Available Rhodium and platinum nanoparticles were supported in polymeric membranes with 10, 20 and 40 µm thickness. The polymeric membranes were prepared combining cellulose acetate and the ionic liquid (IL 1-n-butyl-3-methylimidazolium bis(trifluoromethane sulfonylimide (BMI.(NTf2. The presence of metal nanoparticles induced an increase in the polymeric membrane surface areas. The increase of the IL content resulted in an improvement of elasticity and decrease in tenacity and toughness, whereas the stress at break was not affected. The presence of IL probably causes an increase in the separation between the cellulose molecules that result in a higher flexibility and processability of the polymeric membrane. The CA/IL/M(0 combinations exhibit an excellent synergistic effect that enhances the activity and durability of the catalyst for the hydrogenation of cyclohexene. The CA/IL/M(0 polymeric membrane displays higher catalytic activity (up to 7.353 h-1 for the 20 mm of CA/IL/Pt(0 and stability than the nanoparticles dispersed only in the IL.

  11. Electrochemical reactions of uranyl(VI) complexes in aqueous solution, non-aqueous solvents, and ionic liquids

    International Nuclear Information System (INIS)

    Ikeda, Yasuhisa

    2006-01-01

    Author's recent experimental results on the chemistry of U(V) in aqueous solution, non-aqueous solvents, and ionic solvents by cyclic voltametry are described. The U(V) was produced by electrochemical reduction of uranyl U(VI) ions or complexes such as carbonates, DMF(N, N-dimethylformamide), DMSO(dimethylsulfoxide), acetylacetonato, and other organic polydental ligands. The produced U(V) complexes were studied by spectrophotometry using optical-transmission thin-layer electrode. The U(V) complexes in non-aqueous solvents were found to be rather stable, they undergo ligand-dissociation reaction but not disproportionation reaction. The structure and electronic spectra as well as IR spectra of the complexes were studied. The present method was further developed to study the behavior of U(V) complexes in ionic liquids as molten salts, e.g., alkaline metals chlorides. Thus, the present research contributes to understanding the chemistry of 5fl system. Application to such nuclear technology as spent fuel reprocessing is discussed. (S. Ohno)

  12. On the solid–liquid phase diagrams of binary mixtures of even saturated fatty alcohols: Systems exhibiting peritectic reaction

    Energy Technology Data Exchange (ETDEWEB)

    Carareto, Natália D.D. [EXTRAE, Department of Food Engineering, Food Engineering Faculty, University of Campinas, UNICAMP, CEP 13083-862 Campinas, SP (Brazil); Santos, Adenílson O. dos [Social Sciences, Health and Technology Center, University of Maranhão, UFMA, CEP 65900-410 Imperatriz, MA (Brazil); Rolemberg, Marlus P. [Institute of Science and Technology, University of Alfenas, UNIFAL, Rodovia José AurélioVilela, CEP 37715400 Poços de Caldas, MG (Brazil); Cardoso, Lisandro P. [Institute of Physics GlebWataghin, University of Campinas, UNICAMP, C.P. 6165, CEP 13083-970 Campinas, SP (Brazil); Costa, Mariana C. [School of Applied Science, University of Campinas, UNICAMP, CEP 13484-350 Limeira, SP (Brazil); Meirelles, Antonio J.A., E-mail: tomze@fea.unicamp.br [EXTRAE, Department of Food Engineering, Food Engineering Faculty, University of Campinas, UNICAMP, CEP 13083-862 Campinas, SP (Brazil)

    2014-08-10

    Highlights: • SLE of binary mixtures of saturated fatty alcohols was studied. • Experimental data were obtained using DSC and stepscan DSC. • Microscopy and X-ray diffraction used as complementary techniques. • Systems presented eutectic, peritectic and metatectic points. - Abstract: The solid–liquid phase diagrams of the following binary mixtures of even saturated fatty alcohols are reported in the literature for the first time: 1-octanol (C8OH) + 1-decanol (C10OH), 1-decanol + 1-dodecanol (C12OH), 1-dodecanol + 1-hexadecanol (C16OH) and 1-tetradecanol (C14OH) + 1-octadecanol (C18OH). The phase diagrams were obtained by differential scanning calorimetry (DSC) using a linear heating rate of 1 K min{sup −1} and further investigated by using a stepscan DSC method. X-ray diffraction (XRD) and polarized light microscopy were also used to complement the characterization of the phase diagrams which have shown a complex global behavior, presenting not only peritectic and eutectic reactions, but also the metatectic reaction and partial immiscibility on solid state.

  13. On the solid–liquid phase diagrams of binary mixtures of even saturated fatty alcohols: Systems exhibiting peritectic reaction

    International Nuclear Information System (INIS)

    Carareto, Natália D.D.; Santos, Adenílson O. dos; Rolemberg, Marlus P.; Cardoso, Lisandro P.; Costa, Mariana C.; Meirelles, Antonio J.A.

    2014-01-01

    Highlights: • SLE of binary mixtures of saturated fatty alcohols was studied. • Experimental data were obtained using DSC and stepscan DSC. • Microscopy and X-ray diffraction used as complementary techniques. • Systems presented eutectic, peritectic and metatectic points. - Abstract: The solid–liquid phase diagrams of the following binary mixtures of even saturated fatty alcohols are reported in the literature for the first time: 1-octanol (C8OH) + 1-decanol (C10OH), 1-decanol + 1-dodecanol (C12OH), 1-dodecanol + 1-hexadecanol (C16OH) and 1-tetradecanol (C14OH) + 1-octadecanol (C18OH). The phase diagrams were obtained by differential scanning calorimetry (DSC) using a linear heating rate of 1 K min −1 and further investigated by using a stepscan DSC method. X-ray diffraction (XRD) and polarized light microscopy were also used to complement the characterization of the phase diagrams which have shown a complex global behavior, presenting not only peritectic and eutectic reactions, but also the metatectic reaction and partial immiscibility on solid state

  14. Liquid-liquid transfer phenomena studies coupled with redox reactions: back-extraction of nitrous acid in the presence of scavengers in aqueous phase; Etude de reactions d`oxydoreduction couplees a des phenomenes de transfert liquide-liquide: cas de la desextraction de l`acide nitreux en presence de composes antinitreux en phase aqueuse

    Energy Technology Data Exchange (ETDEWEB)

    K`zerho, R

    1998-12-31

    This work deals with the investigation of redox reaction contribution to the kinetics of liquid-liquid transfer, in relation with PUREX reprocessing of spent nuclear fuel. The chemical system chosen concerns the tripping of nitrous acid from tributylphosphate organic phase into a nitric acid aqueous solution containing an `anti-nitrous` component, namely hydrazinium nitrate. According to the abundant literature, a major attention is devoted to the very important role of interfacial phenomena on the kinetics of solvent extraction with tributylphosphate. Although, a suitable experimental technique is chosen, using a constant interfacial area cell of the ARMOLLEX-type. Furthermore, the effects of the hydrodynamical and the physico-chemical parameters on the extraction rate led to the identification of the extraction regime nature: diffusional, then chemical limitation. When no `anti-nitrous` component is used, the diffusional resistance is found to be mainly located in the aqueous diffusion layer. The presence of hydrazinium nitrate into the aqueous solution has an overall accelerating effect on the rate of extraction, related to both a complete suppression of the aqueous diffusional resistance, and a very significant enhancement of the interfacial transfer of the nitrous acid, as a function of hydrazinium concentration. If the first effect could be expected because of the well known fast redox reaction in aqueous phase, the second phenomenon represents a quite original and new result which has never been explored before, to the best of our knowledge. A reaction mechanism is postulated and validated, taking into account the reactive effect of hydrazinium on the interfacial step. In order to support the drawn general patterns, different complementary studies were attempted. When hydroxyl-ammonium nitrate is used, a surprising interfacial transfer blockage is observed, pointing out the extreme performance and specificity of the common hydrazinium component. (author) 99

  15. Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction.

    Science.gov (United States)

    Saed, Mohand O; Torbati, Amir H; Nair, Devatha P; Yakacki, Christopher M

    2016-01-19

    This study presents a novel two-stage thiol-acrylate Michael addition-photopolymerization (TAMAP) reaction to prepare main-chain liquid-crystalline elastomers (LCEs) with facile control over network structure and programming of an aligned monodomain. Tailored LCE networks were synthesized using routine mixing of commercially available starting materials and pouring monomer solutions into molds to cure. An initial polydomain LCE network is formed via a self-limiting thiol-acrylate Michael-addition reaction. Strain-to-failure and glass transition behavior were investigated as a function of crosslinking monomer, pentaerythritol tetrakis(3-mercaptopropionate) (PETMP). An example non-stoichiometric system of 15 mol% PETMP thiol groups and an excess of 15 mol% acrylate groups was used to demonstrate the robust nature of the material. The LCE formed an aligned and transparent monodomain when stretched, with a maximum failure strain over 600%. Stretched LCE samples were able to demonstrate both stress-driven thermal actuation when held under a constant bias stress or the shape-memory effect when stretched and unloaded. A permanently programmed monodomain was achieved via a second-stage photopolymerization reaction of the excess acrylate groups when the sample was in the stretched state. LCE samples were photo-cured and programmed at 100%, 200%, 300%, and 400% strain, with all samples demonstrating over 90% shape fixity when unloaded. The magnitude of total stress-free actuation increased from 35% to 115% with increased programming strain. Overall, the two-stage TAMAP methodology is presented as a powerful tool to prepare main-chain LCE systems and explore structure-property-performance relationships in these fascinating stimuli-sensitive materials.

  16. Isomerization and self-condensation reactions subsequent the. beta. -decay of tritiated naphthalene in the presence of liquid and gaseous benzene

    Energy Technology Data Exchange (ETDEWEB)

    Angelini, G.; Keheyan, Y.; Lilla, E.; Perez, G. (Consiglio Nazionale delle Ricerche, Rome (Italy). Ist. di Chimica Nucleare)

    1990-01-01

    Tritiated napththylium ions, generated by spontaneous {beta}-decay of (1,4-{sup 3}H) naphthalene, have been allowed to react with benzene molecules in gaseous and liquid phase. The isomeric phenylnaphthalenes and fluoranthene have been found among the reaction products. The differences between the reactivity pattern of naphthylium ion in the two phases can be explained by the different efficiency of collisional stabilization of the excited reaction intermediates. (orig.).

  17. Investigation of corrosion, water reaction, polonium evaporation and bismuth resource in liquid metal lead-bismuth technology

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Hideki; Takizuka, Takakazu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kitano, Teruaki [Mitsui Shipbuilding and Engineering Co. Ltd., Tokyo (Japan)

    2000-10-01

    Lead-bismuth is the first candidate material for liquid metal target find coolant of fueled blanket system in accelerator-driven system (ADS) studied at JAERI. Advantages of the lead-bismuth utilization are non-active material, very low capture cross section, low melting point of 125degC and high boiling point of 1670degC, and beside coolant void reactivity become negative. But problems are due to the high corrosivity to most of the structural materials and the corrosive data are scarcity. In this report, corrosivity, reaction with water, thermal-hydraulics, chemical toxicity etc. are studied by investigating some facilities utilized and researched really for lead or lead-bismuth. And, furthermore, polonium evaporation rate and bismuth resource are investigated. Main results obtained are as follows: (1) In a refinery, there are enough employment experience for liquid Pb-Bi in period of about 17 years and not corrosion for the thermal conductive materials (1Cr-0.5Mo steel) used under the condition of natural convection with temperature around 400degC. (2) In Russia, extensive experience in the use as Russian submarines and in R and D during about 50 years are available. And as a result, it will be able to lead approximately zero corrosion for Cr-Si materials by adjusting oxygen film with oxygen concentration control between 10{sup -7} to 10{sup -5}% mass. However, the corrosion data are not enough systematically collected involving them in radiation dose field. (3) In liquid-dropping experiment, it is shown that interaction between water and high temperature liquid Pb-Bi is reduced steeply with rising of atmosphere pressure. But, in order to design the second circuit removal model of ADS, the interaction should be evaluated by water continuous injection experiment. (4) Polonium forms PbPo in Pb-Bi, and the evaporation rate become less three factor than that of Po, and furthermore, the rate decreases in the atmosphere. The effects of Po on employee and environment

  18. Neutron spectrum adjustment using reaction rate data acquired with a liquid dosimetry system

    International Nuclear Information System (INIS)

    Smith, D.L.; Ikeda, Y.; Uno, Y.; Maekawa, F.

    1997-01-01

    A dosimetry technique based on neutron activation of circulating water with dissolved salts is discussed. The neutron source was the FNS accelerator at JAERI, Tokai, Japan. Yttrium chloride hexahydrate (YCl 3· 6H 2 O) was the salt (264.9 grams dissolved in 16.094 liters of water). Gamma-ray yields were measured with an intrinsic Ge detector. The following reactions were examined: (1) 16 O(n,p) 16 N (E thresh = 10.245 MeV, t 1/2 = 7.13 sec, E γ = 6.129 MeV); (2) 37 Cl(n,p) 37 S (E thresh = 4.194 MeV, t 1/2 = 5.05 min, E γ = 3.104 MeV); (3) 89 Y(n,n') 89m Y (E thresh = 0.919 MeV, t 1/2 = 16.06 sec, E γ = 0.909 MeV). This paper describes use of the generalized least-squares (GLS) method to adjust the neutron spectrum

  19. Determination of citrus limonoid glucosides by high performance liquid chromatography coupled to post-column reaction with Ehrlich’s Reagent

    Science.gov (United States)

    A method for the identification and quantification of citrus limonoid glucosides in juices based upon high performance liquid chromatography (HPLC) separation coupled to post-column reaction with Ehrlichs’s reagent has been developed. This method utilizes a phenyl stationary phase and an isocratic ...

  20. On The Validity of the Assumed PDF Method for Modeling Binary Mixing/Reaction of Evaporated Vapor in GAS/Liquid-Droplet Turbulent Shear Flow

    Science.gov (United States)

    Miller, R. S.; Bellan, J.

    1997-01-01

    An Investigation of the statistical description of binary mixing and/or reaction between a carrier gas and an evaporated vapor species in two-phase gas-liquid turbulent flows is perfomed through both theroetical analysis and comparisons with results from direct numerical simulations (DNS) of a two-phase mixing layer.

  1. Research on Liquid Management Technology in Water Tank and Reactor for Propulsion System with Hydrogen Production System Utilizing Aluminum and Water Reaction

    Science.gov (United States)

    Imai, Ryoji; Imamura, Takuya; Sugioka, Masatoshi; Higashino, Kazuyuki

    2017-12-01

    High pressure hydrogen produced by aluminum and water reaction is considered to be applied to space propulsion system. Water tank and hydrogen production reactor in this propulsion system require gas and liquid separation function under microgravity condition. We consider to install vane type liquid acquisition device (LAD) utilizing surface tension in the water tank, and install gas-liquid separation mechanism by centrifugal force which swirling flow creates in the hydrogen reactor. In water tank, hydrophilic coating was covered on both tank wall and vane surface to improve wettability. Function of LAD in water tank and gas-liquid separation in reaction vessel were evaluated by short duration microgravity experiments using drop tower facility. In the water tank, it was confirmed that liquid was driven and acquired on the outlet due to capillary force created by vanes. In addition of this, it was found that gas-liquid separation worked well by swirling flow in hydrogen production reactor. However, collection of hydrogen gas bubble was sometimes suppressed by aluminum alloy particles, which is open problem to be solved.

  2. Status of U.S. evaluations of acoustic detection of in-sodium water leaks

    International Nuclear Information System (INIS)

    Fletcher, F.L.; Neely, H.H.

    1990-01-01

    An overview of the United States testing program to evaluate acoustic leak detection and location systems on simulated water leaks in functional liquid sodium steam generators is provided. Testing was conducted on the modular hockey stick steam generator during the large leak test program in the LLTR, on the CRBR prototype hockey stick steam generators in SCTI, on a double wall tube steam generator installed in EBR-II and on the helical coil steam generator tested in SCTI. These test programs have demonstrated the acoustic leak detection system potential, however, additional development is required before the system can perform to its effective and required potential. (author). 6 figs

  3. Automatic identification approach for high-performance liquid chromatography-multiple reaction monitoring fatty acid global profiling.

    Science.gov (United States)

    Tie, Cai; Hu, Ting; Jia, Zhi-Xin; Zhang, Jin-Lan

    2015-08-18

    Fatty acids (FAs) are a group of lipid molecules that are essential to organisms. As potential biomarkers for different diseases, FAs have attracted increasing attention from both biological researchers and the pharmaceutical industry. A sensitive and accurate method for globally profiling and identifying FAs is required for biomarker discovery. The high selectivity and sensitivity of high-performance liquid chromatography-multiple reaction monitoring (HPLC-MRM) gives it great potential to fulfill the need to identify FAs from complicated matrices. This paper developed a new approach for global FA profiling and identification for HPLC-MRM FA data mining. Mathematical models for identifying FAs were simulated using the isotope-induced retention time (RT) shift (IRS) and peak area ratios between parallel isotope peaks for a series of FA standards. The FA structures were predicated using another model based on the RT and molecular weight. Fully automated FA identification software was coded using the Qt platform based on these mathematical models. Different samples were used to verify the software. A high identification efficiency (greater than 75%) was observed when 96 FA species were identified in plasma. This FAs identification strategy promises to accelerate FA research and applications.

  4. Picosecond dynamics of reactions in the liquid phase: studies of iodine photodissociation and development of new laser techniques

    International Nuclear Information System (INIS)

    Berg, M.A.

    1985-09-01

    Iodine photodissociation and recombination was studied as a model for processes common to chemical reaction in the liquid phase. Picosecond transient absorption measurements from 1000 to 295 nm were used to monitor the dynamics in a variety of solvents. Most of the atoms which undergo geminate recombination were found to do so in less than or equal to 15 ps, in agreement with the results of existing molecular dynamics simulations. Vibrational relaxation times vary from approx.15 ps near the middle of the ground state well to approx.150 ps for complete relaxation to v = 0. The prediction of strong resonant vibrational energy transfer to chlorinated methane solvents was not supported, but some evidence for this mechanism was found for alkane solvents. Current theory is unable to explain the large variation (65 to 2700 ps) of the excited A'-state lifetime in various solvents. The 10-Hz amplified, synchronously-pumped dye laser which was used in these studies is described and characterized. SERS (Stimulated Electronic Raman Scattering) and difference frequency mixing were used in the generation of the infrared and far-infrared, respectively. 54 refs., 38 figs., 3 tabs

  5. Sodium/water pool-deposit bed model of the CONACS code

    International Nuclear Information System (INIS)

    Peak, R.D.

    1983-01-01

    A new Pool-Bed model of the CONACS (Containment Analysis Code System) code represents a major advance over the pool models of other containment analysis code (NABE code of France, CEDAN code of Japan and CACECO and CONTAIN codes of the United States). This new model advances pool-bed modeling because of the number of significant materials and processes which are included with appropriate rigor. This CONACS pool-bed model maintains material balances for eight chemical species (C, H 2 O, Na, NaH, Na 2 O, Na 2 O 2 , Na 2 CO 3 and NaOH) that collect in the stationary liquid pool on the floor and in the desposit bed on the elevated shelf of the standard CONACS analysis cell

  6. Applications of a post-column fluorigenic reaction in liquid chromatography for the determination of glucose and fructose in biological matrices

    International Nuclear Information System (INIS)

    Coquet, A.; Veuthey, J.-L.; Haerdi, W.; Degli Agosti, R.

    1991-01-01

    A post-column fluorigenic reaction with benzamidine coupled to liquid chromatographic separation was used for the determination of reducing carbohydrates in three complex biological samples. This method allows the simultaneous determination of the different reducing sugars, which represent an improvement over batch enzymatic tests where in most instances only single monosaccharides can be determined. This selective liquid chromatographic method has a broad linear range. The method was validated by simultaneous analyses with a specific enzymatic test for glucose. Results are presented for the determination of glucose in human serum and mustard plants and glucose and fructose in white wines. (author). 14 refs.; 3 figs.; 3 tabs

  7. Liquid waveguide spectrophotometric measurement of nanomolar ammonium in seawater based on the indophenol reaction with o-phenylphenol (OPP).

    Science.gov (United States)

    Hashihama, Fuminori; Kanda, Jota; Tauchi, Ami; Kodama, Taketoshi; Saito, Hiroaki; Furuya, Ken

    2015-10-01

    We describe a highly sensitive colorimetric method for the determination of nanomolar concentrations of ammonium in seawater based on the indophenol reaction with o-phenylphenol [(1,1'-biphenyl)-2-ol, abbreviated as OPP]. OPP is available as non-toxic, stable flaky crystals with no caustic odor and has some advantages over phenol in practical use. The method was established by using a gas-segmented continuous flow analyzer equipped with two types of long path liquid waveguide capillary cell, LWCCs (100 cm and 200 cm) and an UltraPath (200 cm), which have inner diameters of 0.55 mm and 2 mm, respectively. The reagent concentrations, flow rates of the pumping tubes, and reaction path and temperature were determined on the basis of a manual indophenol blue method with OPP (Kanda, Water Res. 29 (1995) 2746-2750). The sample mixed with reagents that form indophenol blue dye was measured at 670 nm. Aged subtropical surface water was used as a blank, a matrix of standards, and the carrier. The detection limits of the analytical systems with a 100 cm LWCC, a 200 cm LWCC, and a 200 cm UltraPath were 6, 4, and 4 nM, respectively. These systems had high precision (<4% at 100 nM) and a linear dynamic range up to 200 nM. Non-linear baseline drift did not occur when using the UltraPath system. This is due to the elimination of cell clogging because of the larger inner diameter of the UltraPath compared to the LWCCs. The UltraPath system is thus more suitable for long-term measurements compared with the LWCC systems. The results of the proposed sensitive colorimetry and a conventional colorimetry for the determination of seawater samples showed no significant difference. The proposed analytical systems were applied to underway surface monitoring and vertical observation in the oligotrophic South Pacific. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Mathematical model to analyze the dissolution behavior of metastable crystals or amorphous drug accompanied with a solid-liquid interface reaction.

    Science.gov (United States)

    Hirai, Daiki; Iwao, Yasunori; Kimura, Shin-Ichiro; Noguchi, Shuji; Itai, Shigeru

    2017-04-30

    Metastable crystals and the amorphous state of poorly water-soluble drugs in solid dispersions (SDs), are subject to a solid-liquid interface reaction upon exposure to a solvent. The dissolution behavior during the solid-liquid interface reaction often shows that the concentration of drugs is supersaturated, with a high initial drug concentration compared with the solubility of stable crystals but finally approaching the latter solubility with time. However, a method for measuring the precipitation rate of stable crystals and/or the potential solubility of metastable crystals or amorphous drugs has not been established. In this study, a novel mathematical model that can represent the dissolution behavior of the solid-liquid interface reaction for metastable crystals or amorphous drug was developed and its validity was evaluated. The theory for this model was based on the Noyes-Whitney equation and assumes that the precipitation of stable crystals at the solid-liquid interface occurs through a first-order reaction. Moreover, two models were developed, one assuming that the surface area of the drug remains constant because of the presence of excess drug in the bulk and the other that the surface area changes in time-dependency because of agglomeration of the drug. SDs of Ibuprofen (IB)/polyvinylpyrrolidone (PVP) were prepared and their dissolution behaviors under non-sink conditions were fitted by the models to evaluate improvements in solubility. The model assuming time-dependent surface area showed good agreement with experimental values. Furthermore, by applying the model to the dissolution profile, parameters such as the precipitation rate and the potential solubility of the amorphous drug were successfully calculated. In addition, it was shown that the improvement in solubility with supersaturation was able to be evaluated quantitatively using this model. Therefore, this mathematical model would be a useful tool to quantitatively determine the supersaturation

  9. Oxygen reduction reaction properties of nitrogen-incorporated nanographenes synthesized using in-liquid plasma from mixture of ethanol and iron phthalocyanine

    Science.gov (United States)

    Amano, Tomoki; Kondo, Hiroki; Takeda, Keigo; Ishikawa, Kenji; Hiramatsu, Mineo; Sekine, Makoto; Hori, Masaru

    2018-04-01

    Nanographenes were synthesized using in-liquid plasma from a mixture of iron phthalocyanine and ethanol. In a previous study, micrometer-scale flakes with nitrogen incorporation were obtained. A nonprecious metal catalytic activity was observed with 3.13 electrons in an oxygen reduction reaction under an acidic solute condition. Large-surface-area, high-graphene-crystallinity, and iron-carbon-bonding sites were found owing to a high catalytic activity in Fe-N/nanographene.

  10. Investigation of the kinetic mechanism of the demanganization reaction between carbon-saturated liquid iron and CaF2-CaO-SiO2-based slags

    Science.gov (United States)

    Duan, Sheng-chao; Li, Chuang; Guo, Han-jie; Guo, Jing; Han, Shao-wei; Yang, Wen-sheng

    2018-04-01

    The demanganization reaction kinetics of carbon-saturated liquid iron with an eight-component slag consisting of CaO-SiO2-MgO-FeO-MnO-Al2O3-TiO2-CaF2 was investigated at 1553, 1623, and 1673 K in this study. The rate-controlling step (RCS) for the demanganization reaction with regard to the hot metal pretreatment conditions was studied via kinetics analysis based on the fundamental equation of heterogeneous reaction kinetics. From the temperature dependence of the mass transfer coefficient of a transition-metal oxide (MnO), the apparent activation energy of the demanganization reaction was estimated to be 189.46 kJ·mol-1 in the current study, which indicated that the mass transfer of MnO in the molten slag controlled the overall rate of the demanganization reaction. The calculated apparent activation energy was slightly lower than the values reported in the literature for mass transfer in a slag phase. This difference was attributed to an increase in the "specific reaction interface" (SRI) value, either as a result of turbulence at the reaction interface or a decrease of the absolute amount of slag phase during sampling, and to the addition of calcium fluoride to the slag.

  11. A simple method to prepare ZnO and Al(OH)3 nanorods by the reaction of the metals with liquid water

    International Nuclear Information System (INIS)

    Panchakarla, L.S.; Shah, M.A.; Govindaraj, A.; Rao, C.N.R.

    2007-01-01

    Reaction of liquid water with Zn and Al powders and foils have been investigated in the 25-75 deg. C range. The reaction of Zn metal powder with water in this temperature range yields ZnO nanorods. The diameter of the nanorods decreases slightly with the increase in the reaction temperature, accompanied by an increase in the relative intensity of UV emission band. Zn metal foils also yield ZnO nanorods on reaction with water in the 25-75 deg. C range. Reaction of Al metal powder or foil with water in the 25-75 deg. C range yields Al(OH) 3 nanorods. The formation of ZnO and Al(OH) 3 nanorods by the reaction of the metals with water is suggested to occur because of the decomposition of water by the metal giving hydrogen. - Graphical abstract: The reaction of water at a temperature in the 25-27 deg. C range with zinc metal gives rise to ZnO nanorods; with Al metal water gives Al(OH) 3 nanorods

  12. Safety analysis of exothermic reaction hazards associated with the organic liquid layer in tank 241-C-103

    International Nuclear Information System (INIS)

    Postma, A.K.; Bechtold, D.B.; Borsheim, G.L.; Grisby, J.M.; Guthrie, R.L.; Kummerer, M.; Turner, D.A.; Plys, M.G.

    1994-03-01

    Safety hazards associated with the interim storage of a potentially flammable organic liquid in waste Tank C-103 are identified and evaluated. The technical basis for closing the unreviewed safety question (USQ) associated with the floating liquid organic layer in this tank is presented

  13. Safety analysis of exothermic reaction hazards associated with the organic liquid layer in tank 241-C-103

    Energy Technology Data Exchange (ETDEWEB)

    Postma, A.K.; Bechtold, D.B.; Borsheim, G.L.; Grisby, J.M.; Guthrie, R.L.; Kummerer, M.; Turner, D.A. [Westinghouse Hanford Co., Richland, WA (United States); Plys, M.G. [Fauske and Associates, Inc., Burr Ridge, IL (United States)

    1994-03-01

    Safety hazards associated with the interim storage of a potentially flammable organic liquid in waste Tank C-103 are identified and evaluated. The technical basis for closing the unreviewed safety question (USQ) associated with the floating liquid organic layer in this tank is presented.

  14. Exchange reactions between a molten salt and a solution of tri-butyl phosphate in a liquid silicone; Reactions d'echange entre un sel fondu et une solution de phosphate de tributyle dans un silicone liquide

    Energy Technology Data Exchange (ETDEWEB)

    Hertzog, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    . The equilibrium constants for the reactions: (I) Co{sup 2+} + CN{sup -} {yields} CoCN{sup +} (II) Co{sup 2+} + Cl{sup -}{yields} CoCl{sup +} have been determined: K{sub 1} 10{sup -4}, K{sub 2} = 0.16. (author) [French] L'interet actuel porte aux sels fondus s'explique par leur emploi possible clans le domaine de l'energie nucleaire, en particulier comme supports de combustibles et comme agents de reprocessing. II nous a paru interessant de considerer un sel fondu comme un solvant et d'y etudier les phenomenes de partage avec une seconde phase stable a haute temperature. Le sel choisi est un eutectique ternaire de nitrates alcalins et la seconde phase est une solution de phosphate de tributyle dans un silicone liquide. La temperature de travail est fixee a 150 deg. C. Nous avons etudie en premier lieu la stabilite des deux phases et leurs solubilites respectives a cette temperature. On a demontre que les deux solvants sont immiscibles et stables. D'autre part nous avons decrit l'extraction par la solution de silicone de differents corps en solution dans la phase sel, determine les coefficients de partage et les formules des molecules extraites. Il nous a ete possible de calculer les coefficients de partage des cations suivants extraits sous la forme nitrates: Li{sup +}, Na{sup +}, K{sup +}, Sr{sup 2+}, Ca{sup 2+}, Ba{sup 2+}, Hg{sup 2+} dont les coefficients de partage sont tres faibles: Mg{sup 2+}, Ni{sup 2+}, Co{sup 2+}, Zn{sup 2+}, dont les rendements d'extraction sont superieurs a 50 pour cent; enfin Ce{sup 3+}, La{sup 3+}, UO{sub 2}{sup 2+}, tres extraits. De meme les anions suivants ont ete extraits sous forme de sels alcalins: F{sup -}, Cl{sup -}, Br{sup -}, I{sup -}, IO{sub 3}{sup -}, CN{sup -}, SO{sub 4}{sup -}, C{sub 2}O{sub 4}{sup -}, NO{sub 2}{sup -}. Parmi ceux-ci seuls les halogenes ont des coefficients de partage non negligeables. Dans certains cas particuliers, nous avons pu etudier l'influence de la formation de complexes sur les phenomenes d

  15. Characteristics of liquid product from the pyrolysis of waste plastic mixture at low and high temperatures: influence of lapse time of reaction.

    Science.gov (United States)

    Lee, Kyong-Hwan; Shin, Dae-Hyun

    2007-01-01

    Pyrolysis of a waste plastic mixture (high-density polyethylene: low-density polyethylene: polypropylene: polystyrene = 3:2:3:1) into a liquid product was carried out in a stirred semi-batch reactor at low (350 degrees C) and high (400 degrees C) temperatures. The effect of lapse time of reaction in the reactor and also degradation temperature on the characteristics of the liquid product from pyrolysis of the mixture was investigated. Liquid products were described by cumulative amount distribution, paraffin, olefin, naphthene and aromatic (PONA) distribution and molecular weight distribution. Their characteristic was quite differed with a lapse time of reaction and also at a low and high degradation temperatures, because of the different physicochemical properties of the plastic types in the mixture. With increase of lapse time of reaction, the order for the main products in PONA components obtained at 350 degrees C was firstly aromatic products and then olefin products, while at 400 degrees C the order was firstly aromatic products, then olefin products and finally paraffin products. The experiments also showed from the molecular weight distribution of liquid PONA components that the paraffin and olefin products had a wide distribution by mainly random scission of polymer, but in the case of olefin products were produced by an end-chain scission mechanism as well as random scission mechanism, as evidenced by much more light olefin products. This phenomenon was evident at a higher degradation temperature. Also, both the light olefin and naphthene products with a molecular weight of around 120, as a main product, showed a similar trend as a function of lapse time, which had a maximum fraction at 343 min (at 350 degrees C) and 83 min (at 400 degrees C). Among PONA components, the highest concentrations of aromatic products were obtained with a molecular weight of around 100 at the fastest lapse time of reaction, regardless of degradation temperature. It was

  16. Characteristics of liquid product from the pyrolysis of waste plastic mixture at low and high temperatures: Influence of lapse time of reaction

    International Nuclear Information System (INIS)

    Lee, Kyong-Hwan; Shin, Dae-Hyun

    2007-01-01

    Pyrolysis of a waste plastic mixture (high-density polyethylene: low-density polyethylene: polypropylene: polystyrene = 3:2:3:1) into a liquid product was carried out in a stirred semi-batch reactor at low (350 deg. C) and high (400 deg. C) temperatures. The effect of lapse time of reaction in the reactor and also degradation temperature on the characteristics of the liquid product from pyrolysis of the mixture was investigated. Liquid products were described by cumulative amount distribution, paraffin, olefin, naphthene and aromatic (PONA) distribution and molecular weight distribution. Their characteristic was quite differed with a lapse time of reaction and also at a low and high degradation temperatures, because of the different physicochemical properties of the plastic types in the mixture. With increase of lapse time of reaction, the order for the main products in PONA components obtained at 350 deg. C was firstly aromatic products and then olefin products, while at 400 deg. C the order was firstly aromatic products, then olefin products and finally paraffin products. The experiments also showed from the molecular weight distribution of liquid PONA components that the paraffin and olefin products had a wide distribution by mainly random scission of polymer, but in the case of olefin products were produced by an end-chain scission mechanism as well as random scission mechanism, as evidenced by much more light olefin products. This phenomenon was evident at a higher degradation temperature. Also, both the light olefin and naphthene products with a molecular weight of around 120, as a main product, showed a similar trend as a function of lapse time, which had a maximum fraction at 343 min (at 350 deg. C) and 83 min (at 400 deg. C). Among PONA components, the highest concentrations of aromatic products were obtained with a molecular weight of around 100 at the fastest lapse time of reaction, regardless of degradation temperature. It was concluded that the

  17. Development of liquid-lithium film jet-flow for the target of (7)Li(p,n)(7)Be reactions for BNCT.

    Science.gov (United States)

    Kobayashi, Tooru; Miura, Kuniaki; Hayashizaki, Noriyosu; Aritomi, Masanori

    2014-06-01

    A feasibility study on liquid lithium target in the form of a flowing film was performed to evaluate its potential use as a neutron generation target of (7)Li(p,n)(7)Be reaction in BNCT. The target is a windowless-type flowing film on a concave wall. Its configuration was adapted for a proton beam which is 30mm in diameter and with energy and current of up to 3MeV and 20mA, respectively. The flowing film of liquid lithium was 0.6mm in thickness, 50mm in width and 50mm in length. The shapes of the nozzle and concave back wall, which create a stable flowing film jet, were decided based on water experiments. A lithium hydrodynamic experiment was performed to observe the stability of liquid lithium flow behavior. The flowing film of liquid lithium was found to be feasible at temperatures below the liquid lithium boiling saturation of 342°C at the surface pressure of 1×10(-3)Pa. Using a proto-type liquid lithium-circulating loop for BNCT, the stability of the film flow was confirmed for velocities up to 30m/s at 220°C and 250°C in vacuum at a pressure lower than 10(-3) Pa. It is expected that for practical use, a flowing liquid lithium target of a windowless type can solve the problem of radiation damage and target cooling. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Accelerating rate calorimetry studies of the reactions between ionic liquids and charged lithium ion battery electrode materials

    International Nuclear Information System (INIS)

    Wang, Yadong; Zaghib, K.; Guerfi, A.; Bazito, Fernanda F.C.; Torresi, Roberto M.; Dahn, J.R.

    2007-01-01

    Using accelerating rate calorimetry (ARC), the reactivity between six ionic liquids (with and without added LiPF 6 ) and charged electrode materials is compared to the reactivity of standard carbonate-based solvents and electrolytes with the same electrode materials. The charged electrode materials used were Li 1 Si, Li 7 Ti 4 O 12 and Li 0.45 CoO 2 . The experiments showed that not all ionic liquids are safer than conventional electrolytes/solvents. Of the six ionic liquids tested, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMI-FSI) shows the worst safety properties, and is much worse than conventional electrolyte. 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI) and 1-propyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (Py13-FSI) show similar reactivity to carbonate-based electrolyte. The three ionic liquids 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide (BMMI-TFSI), 1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide (Pp14-TFSI) and N-trimethyl-N-butylammonium bis(trifluoromethanesulfonyl)imide (TMBA-TFSI) show similar reactivity and are much safer than the conventional carbonate-based electrolyte. A comparison of the reactivity of ionic liquids with common anions and cations shows that ionic liquids with TFSI - are safer than those with FSI - , and liquids with EMI + are worse than those with BMMI + , Py13 + , Pp14 + and TMBA +

  19. Conceptual safety design analysis of Korea advanced liquid metal reactor

    International Nuclear Information System (INIS)

    Suk, S. D.; Park, C. K.

    1999-01-01

    The national long-term R and D program, updated in 1977, requires Korea Atomic Energy Research Institute (KAERI) to complete by the year 2006 the basic design of Korea Advanced Liquid Metal Reactor (KALIMER), along with supporting R and D work, with the capability of resolving the issue of spent fuel storage as well as with significantly enhanced safety. KALIMER is a 150 Mwe pool-type sodium cooled prototype reactor that uses metallic fuel. The conceptual design is currently under way to establish a self-consistent design meeting a set of major safety design requirements for accident prevention. Some of the current emphasis includes those for inherent and passive means of negative reactivity insertion and decay heat removal, high shutdown reliability, prevention of and protection from sodium chemical reaction, and high seismic margin, among others. All of these requirements affect the reactor design significantly and involve extensive supporting R and D programs. This paper summarizes some of the results of conceptual engineering and design analyses performed for the safety of KALIMER in the area of inherent safety, passive decay heat removal, sodium water reaction, and seismic isolation. (author)

  20. Studies of Heterogeneously Catalyzed Liquid-Phase Alcohol Oxidation on Platinum bySum-frequency Generation Vibrational Spectroscopy and Reaction Rate Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Christopher [Univ. of California, Berkeley, CA (United States)

    2014-05-15

    Compared to many branches of chemistry, the molecular level study of catalytically active surfaces is young. Only with the invention of ultrahigh vacuum technology in the past half century has it been possible to carry out experiments that yield useful molecular information about the reactive occurrences at a surface. The reason is two-fold: low pressure is necessary to keep a surface clean for an amount of time long enough to perform an experiment, and most atomic scale techniques that are surface speci c (x-ray photoelectron spectroscopy, electron energy loss spectroscopy, Auger electron spectroscopy, etc.) cannot be used at ambient pressures, because electrons, which act as chemical probes in these techniques, are easily scattered by molecules. Sum-frequency generation (SFG) vibrational spectroscopy is one technique that can provide molecular level information from the surface without the necessity for high vacuum. Since the advent of SFG as a surface spectroscopic tool it has proved its worth in the studies of surface catalyzed reactions in the gas phase, with numerous reactions in the gas phase having been investigated on a multitude of surfaces. However, in situ SFG characterization of catalysis at the solid-liquid interface has yet to be thoroughly pursued despite the broad interest in the use of heterogeneous catalysts in the liquid phase as replacements for homogeneous counterparts. This work describes an attempt to move in that direction, applying SFG to study the solid-liquid interface under conditions of catalytic alcohol oxidation on platinum.

  1. Rapid determination of alkaloids in Macleaya cordata using ionic liquid extraction followed by multiple reaction monitoring UPLC-MS/MS analysis.

    Science.gov (United States)

    Li, Linqiu; Huang, Mingyuan; Shao, Junli; Lin, Bokun; Shen, Qing

    2017-02-20

    The ultrasonic-assisted extraction (UAE) and ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) have been successfully applied in extracting of six alkaloids from M. cordata. 1-hexyl-3-methylimidazolium tetrafluoroborate ([C 6 MIM][BF 4 ]) aqueous solution was used as extraction solvent. The target analytes in raw material were deposited into a single drop of 1-hexyl-3-methylimidazolium hexafluorophosphate ([C 6 MIM][PF 6 ]), which was in situ formed by mixing [C 6 MIM][BF 4 ] and potassium hexafluorophosphate ([K][PF 6 ]. Afterwards, the extract was analyzed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) in multiple-reaction monitoring (MRM) mode. The proposed method was fully validated in terms of linearity (0.9983-0.9992), LOD (0.080ngmL -1 ), LOQ (0.25ngmL -1 ), intra-day precision (MS/MS is powerful and practical for analyzing alkaloids in M. cordata., and it also has great potential for comprehensive quality control of other herbal medicines. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Study on flow characteristics of chemically reacting liquid jet

    International Nuclear Information System (INIS)

    Hong Seon Dae; Okamoto, Koji; Takata, Takashi; Yamaguchi, Akira

    2004-07-01

    Tube rupture accidents in steam generators of sodium-cooled fast breeder reactors are important for safety because the rupture may propagates to neighboring tubes due to sodium-water reaction. In order to clarify the thermal-hydraulic phenomena in the accidents, the flow pattern and the interface in multi-phase flow must be investigated. The JNC cooperative research scheme on the nuclear fuel cycle with the University of Tokyo has been carried to develop a simultaneous measurement system of concentration and velocity profiles and to evaluate influence of chemical reaction on mixing phenomena. In the experiments, aqueous liquor of acetic acid and ammonium hydroxide are selected as a simulant fluid instead of liquid sodium and water vapor. The following conclusions are obtained in this research. Laser Induced Fluorescence (LIF) technique was adopted to measure reacting zone and pH distribution in chemically reacting liquid round free jet. As a result, it was found that the chemical reaction, which took place at the interface between the jet and outer flow, suppressed the mixing phenomenon (in 2001 research). Dynamic Particle Image Velocimetry (PIV) method was developed to measure instantaneous velocity profile with high temporal resolution. In the Dynamic PIV, a high-speed video camera coupled with a high-speed laser pulse generator was implemented. A time-line trend of interfacial area in the free jet was investigated with the Dynamic PIV. This technique was also applied to a complicated geometry (in 2002 research). A new algorithms for image analysis was developed to evaluated the Dynamic PIV data in detail. The characteristics of the mixing phenomenon with reacting jet such as the turbulent kinetic energy and the Reynolds stress were estimated in a spatial and temporal spectrum (in 2003 research). (author)

  3. Combination of in situ metathesis reaction with a novel "magnetic effervescent tablet-assisted ionic liquid dispersive microextraction" for the determination of endogenous steroids in human fluids.

    Science.gov (United States)

    Wu, Jia; Xu, Zilin; Pan, Yixuan; Shi, Yi; Bao, Xiujie; Li, Jun; Tong, Yu; Tang, Han; Ma, Shuyan; Wang, Xuedong; Lyu, Jianxin

    2018-05-01

    Herein, a novel magnetic effervescence tablet-assisted microextraction coupled to in situ metathesis reaction of ionic liquid (IS-META-ILDM) is presented for the determination of four endogenous steroids in human urine, pregnant women's blood, and fetal umbilical cord blood. The magnetic effervescent tablets, which were composed of Fe 3 O 4 nanoparticles, sodium carbonate (alkaline source), and tartaric acid (acidic source), were used to disperse the extractant and for convenient magnetic separation. After the effervescent reaction, in situ reaction between NH 4 PF 6 and [C 6 MIM]BF 4 was adopted to change hydrophilic ionic liquid to hydrophobic liquid, which could be separated from the aqueous phase. The newly developed method has three obvious advantages: (1) combination of effervescent dispersion and magnetic nanoparticles' retrieval is cost-effective and the dispersion and collection of the extractant can be completed almost simultaneously; (2) as compared to temperature-controlled ionic liquid dispersive microextraction and cold-induced solidified microextraction, this method avoids a heating and cooling process which significantly reduces the extraction time and energy cost; and (3) the combination of adsorption by magnetic nanoparticles with extraction by in situ metathesis reaction easily produces high recoveries for target analytes. The optimized composition of effervescent tablet and experimental parameters are as follows: 0.64 g mixture of sodium carbonate and tartaric acid, 7 mg of Fe 3 O 4 (20 nm) as magnetic sorbents, 40 μL of [C 6 MIM]BF 4 as the extraction solvent, 0.15 g NH 4 PF 6 , and 300 μL of elution solvent. Under the optimized conditions, the newly developed method provided high extraction recoveries (90.0-118.5%) and low LODs (0.14-0.17 μg L -1 ) in urine and blood samples. In total, this IS-META-ILDM method provided high extraction efficiency, fast and convenient separation, and underutilization of any organic solvent, and thus

  4. Many-electron electrochemical processes. Reactions in molten salts, room-temperature ionic liquids and ionic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Andriiko, Aleksandr A. [National Technical Univ. Ukraine, Kyiv (Ukraine). Kyiv Polytechnic Inst.; Andriyko, Yuriy O. [CEST Centre of Electrochemical Surface Technology, Wiener Neustadt (Austria); Nauer, Gerhard E. [Vienna Univ. (Austria). Inst. of Physical Chemistry

    2013-02-01

    The authors provide a unified concept for understanding multi-electron processes in electrochemical systems such as molten salts, ionic liquids, or ionic solutions. A major advantage of this concept is its independence of assumptions like one-step many-electron transfers or 'discrete' discharge of complex species. This book contains the following main topics: 1. Many-electron electrochemical systems: Concepts and definitions. 2. Many-electron systems at equilibrium. 3. Phenomenology of electrochemical kinetics. 4. Electrode film systems: experimental evidences. 5. Dynamics of a non-equilibrium electrochemical system. 6. Electrochemistry of Ti(IV) in ionic liquids.

  5. Chemical effects associated to (n, γ) nuclear reactions in diluted aqueous solutions of liquid or frozen organic halogenides

    International Nuclear Information System (INIS)

    Bermudez Rodriguez, I.M.

    1985-09-01

    Chemical effects associated to nuclear transformation 37 Cl (n, γ) 38 Cl or 127 I (n, γ) 128 I in solid or liquid aqueous solutions of ethyl iodide, trichloro-ethylene, thyroxine or DDT irradiated in a nuclear reactor are studied. The retention of radiohalogen under its initial chemical shape decrease with solute concentration in liquid phase but is almost constant with solute dilution in the solid phase. Potential applications in neutron activation analysis evidencing halogenated molecules in irradiated media are discussed. 57 refs [fr

  6. Synthesis and Characterization of Benzimidazolium Salts as Novel Ionic Liquids and their Catalytic Behavior in the Reaction of Alkylation

    Institute of Scientific and Technical Information of China (English)

    Wei Guo HUANG; Bo CHEN; Yuan Yuan WANG; Li Yi DAI; Yong Kui SHAN

    2005-01-01

    A new series of ionic liquids have been prepared containing benzimidazolium cation (abbreviated as Bim). These salts were characterized by DSC, NMR, elemental analysis and thermogravimetric analysis. They showed different properties compared to imidazolium cation due to the introduction of benzene ring. The alkylation of benzene/diphenyl ether with 1-dodecene was carried in C4eBimBr-AlCl3 ionic liquids showing high catalytic activity when the mole ratio of C4eBimB:AlCl3 was 1:2.

  7. Monitoring of an esterification reaction by on-line direct liquid sampling mass spectrometry and in-line mid infrared spectrometry with an attenuated total reflectance probe

    International Nuclear Information System (INIS)

    Owen, Andrew W.; McAulay, Edith A.J.; Nordon, Alison; Littlejohn, David; Lynch, Thomas P.; Lancaster, J. Steven; Wright, Robert G.

    2014-01-01

    Highlights: • High efficiency thermal vaporiser designed and used for on-line reaction monitoring. • Concentration profiles of all reactants and products obtained from mass spectra. • By-product formed from the presence of an impurity detected by MS but not MIR. • Mass spectrometry can detect trace and bulk components unlike molecular spectrometry. - Abstract: A specially designed thermal vaporiser was used with a process mass spectrometer designed for gas analysis to monitor the esterification of butan-1-ol and acetic anhydride. The reaction was conducted at two scales: in a 150 mL flask and a 1 L jacketed batch reactor, with liquid delivery flow rates to the vaporiser of 0.1 and 1.0 mL min −1 , respectively. Mass spectrometry measurements were made at selected ion masses, and classical least squares multivariate linear regression was used to produce concentration profiles for the reactants, products and catalyst. The extent of reaction was obtained from the butyl acetate profile and found to be 83% and 76% at 40 °C and 20 °C, respectively, at the 1 L scale. Reactions in the 1 L reactor were also monitored by in-line mid-infrared (MIR) spectrometry; off-line gas chromatography (GC) was used as a reference technique when building partial least squares (PLS) multivariate calibration models for prediction of butyl acetate concentrations from the MIR spectra. In validation experiments, good agreement was achieved between the concentration of butyl acetate obtained from in-line MIR spectra and off-line GC. In the initial few minutes of the reaction the profiles for butyl acetate derived from on-line direct liquid sampling mass spectrometry (DLSMS) differed from those of in-line MIR spectrometry owing to the 2 min transfer time between the reactor and mass spectrometer. As the reaction proceeded, however, the difference between the concentration profiles became less noticeable. DLSMS had advantages over in-line MIR spectrometry as it was easier to generate

  8. On-line detection of illicit substances in liquid phase with proton-transfer-reaction mass spectrometry (PTR-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Juerschik, Simone; Agarwal, Bishu; Petersson, Fredrik [Institut fuer Ionenphysik und Angewandte Physik, Universitaet Innsbruck, Technikerstr. 25, 6020 Innsbruck (Austria); Sulzer, Philipp; Haidacher, Stefan; Jordan, Alfons; Schottkowsky, Ralf; Hartungen, Eugen; Hanel, Gernot; Seehauser, Hans; Maerk, Lukas [IONICON Analytik GmbH, Eduard-Bodem-Gasse 3, 6020 Innsbruck (Austria); Maerk, Tilmann D. [Institut fuer Ionenphysik und Angewandte Physik, Universitaet Innsbruck, Technikerstr. 25, 6020 Innsbruck (Austria); IONICON Analytik GmbH, Eduard-Bodem-Gasse 3, 6020 Innsbruck (Austria)

    2011-07-01

    The direct aqueous injection (DAI) technique was recently utilized for the detection of illicit substances in liquid phase. DAI turns out to be an ideal solution for direct analysis of liquid samples, since we can make good use of the outstanding advantages, such as real-time analysis, no sample preparation, low detection limits and short response time. Differences in TNT concentration in the water could be seen dependent on time and original size of the pieces and we could demonstrate a linear correlation between the concentration in liquid and the PTR-MS signal. Furthermore, we were also able to demonstrate that this method is capable of detecting minute traces of ''rape drugs'', i.e. {gamma}-butyrolactone and 1,4-butanediol, in liquids. This new method achieving sensitivities in the around 100 pptw range appears therefore well suited for the fight against drug crime and terrorism and for the evaluation of contamination of ammunition dumping sites.

  9. Vapour–Liquid and Chemical Equilibria in the Ethyl Ethanoate + Ethanol + Propyl Ethanoate + Propanol System Accompanied with Transesterification Reaction

    Czech Academy of Sciences Publication Activity Database

    Pavlíček, Jan; Bogdanić, Grozdana; Wichterle, Ivan

    2012-01-01

    Roč. 328, AUG 25 (2012), s. 61-68 ISSN 0378-3812 R&D Projects: GA ČR GA104/07/0444 Institutional support: RVO:67985858 Keywords : transesterification * vapour-liquid equilibrium * correlation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.379, year: 2012

  10. Isothermal Vapor-Liquid Equilibrium in the Quaternary Water + 2-Propanol + Acetic Acid + Isopropyl Acetate System with Chemical Reaction

    Czech Academy of Sciences Publication Activity Database

    Teodorescu, M.; Aim, Karel; Wichterle, Ivan

    2001-01-01

    Roč. 46, č. 2 (2001), s. 261-266 ISSN 0021-9568 R&D Projects: GA ČR GA203/98/1446 Institutional research plan: CEZ:AV0Z4072921 Keywords : vapor-liquid equilibrium * quaternary water Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.960, year: 2001

  11. Functionalization of multi-walled carbon nanotubes with iron phthalocyanine via a liquid chemical reaction for oxygen reduction in alkaline media

    Science.gov (United States)

    Yan, Xiaomei; Xu, Xiao; Liu, Qin; Guo, Jia; Kang, Longtian; Yao, Jiannian

    2018-06-01

    Iron single-atom catalyst in form of iron-nitrogen-carbon structure possesses the excellent catalytic activity in various chemical reactions. However, exploring a sustainable and stable single-atom metal catalyst still faces a great challenge due to low yield and complicated synthesis. Here, we report a functional multi-wall carbon nanotubes modified with iron phthalocyanine molecules via a liquid chemical reaction and realize the performance of similar single-atom catalysis for oxygen reduction reaction. A serial of characterizations strongly imply the structure change of iron phthalocyanine molecule and its close recombination with multi-wall carbon nanotubes, which are in favor of ORR catalysis. Compared to commercial platinum-carbon catalyst, composites exhibit superior activity for oxygen reduction reaction with higher half-wave potential (0.86 V), lower Tafel slope (38 mV dec-1), higher limiting current density and excellent electrochemical stability. The corresponding Zinc-air battery also presents higher maximum power density and discharge stability. Therefore, these findings provide a facile route to synthesize a highly efficient non-precious metal carbon-based catalyst.

  12. Physics of Fresh Produce Safety: Role of Diffusion and Tissue Reaction in Sanitization of Leafy Green Vegetables with Liquid and Gaseous Ozone-Based Sanitizers.

    Science.gov (United States)

    Shynkaryk, Mykola V; Pyatkovskyy, Taras; Mohamed, Hussein M; Yousef, Ahmed E; Sastry, Sudhir K

    2015-12-01

    Produce safety has received much recent attention, with the emphasis being largely on discovery of how microbes invade produce. However, the sanitization operation deserves more attention than it has received. The ability of a sanitizer to reach the site of pathogens is a fundamental prerequisite for efficacy. This work addresses the transport processes of ozone (gaseous and liquid) sanitizer for decontamination of leafy greens. The liquid sanitizer was ineffective against Escherichia coli K-12 in situations where air bubbles may be trapped within cavities. A model was developed for diffusion of sanitizer into the interior of produce. The reaction rate of ozone with the surface of a lettuce leaf was determined experimentally and was used in a numerical simulation to evaluate ozone concentrations within the produce and to determine the time required to reach different locations. For aqueous ozone, the penetration depth was limited to several millimeters by ozone self-decomposition due to the significant time required for diffusion. In contrast, gaseous sanitizer was able to reach a depth of 100 mm in several minutes without depletion in the absence of reaction with surfaces. However, when the ozone gas reacted with the produce surface, gas concentration was significantly affected. Simulation data were validated experimentally by measuring ozone concentrations at the bottom of a cylinder made of lettuce leaf. The microbiological test confirmed the relationship between ozone transport, its self-decomposition, reaction with surrounding materials, and the degree of inactivation of E. coli K-12. Our study shows that decontamination of fresh produce, through direct contact with the sanitizer, is more feasible with gaseous than with aqueous sanitizers. Therefore, sanitization during a high-speed washing process is effective only for decontaminating the wash water.

  13. New evidence on the formation of oxidizing species in corona discharge in contact with liquid and their reactions with organic compounds.

    Science.gov (United States)

    Magureanu, M; Dobrin, D; Bradu, C; Gherendi, F; Mandache, N B; Parvulescu, V I

    2016-12-01

    The objective of these investigations is to understand in more detail how organic compounds in water are degraded during plasma treatment. The formation of oxidizing species (ozone (O 3 ), hydrogen peroxide (H 2 O 2 ) and hydroxyl radicals (OH)) in a pulsed corona discharge in contact with liquid is investigated. The degradation of a target organic compound (methylparaben) in aqueous solution was increased when combining plasma treatment with ozonation, using the O 3 generated in the discharge. Enhanced mass transfer of O 3 obtained in this plasma+O 3 configuration leads to a six fold increase of MeP oxidation rate. The evolution of oxidants concentration during treatment of MeP solutions provides information on their consumption in reactions with MeP and its oxidation products. The correlation of MeP degradation results (MeP removal and mineralization) with O 3 consumption and the identified reaction products confirms that although O 3 plays an important role in the degradation, for the mineralization OH radicals have an essential contribution. The concentration of OH radicals is diminished in the solutions containing MeP as compared to plasma-treated water, indicating OH consumption in reactions with the target compound and its degradation products. The concentration of H 2 O 2 in the liquid can be either increased or reduced in the presence of MeP, depending on its initial concentration. On the one hand, decomposition of H 2 O 2 by OH or O 3 is suppressed in the presence of MeP, but on the other hand less OH radicals are available for its formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Optimization of o-phtaldialdehyde/2-mercaptoethanol postcolumn reaction for the hydrophilic interaction liquid chromatography determination of memantine utilizing a silica hydride stationary phase.

    Science.gov (United States)

    Douša, Michal; Pivoňková, Veronika; Sýkora, David

    2016-08-01

    A rapid procedure for the determination of memantine based on hydrophilic interaction chromatography with fluorescence detection was developed. Fluorescence detection after postcolumn derivatization with o-phtaldialdehyde/2-mercaptoethanol was performed at excitation and emission wavelengths of 345 and 450 nm, respectively. The postcolumn reaction conditions such as reaction temperature, derivatization reagent flow rate, and reagents concentration were studied due to steric hindrance of amino group of memantine. The derivatization reaction was applied for the hydrophilic interaction liquid chromatography method which was based on Cogent Silica-C stationary phase with a mobile phase consisting of a mixture of 10 mmol/L citric acid and 10 mmol/L o-phosphoric acid (pH 6.0) with acetonitrile using an isocratic composition of 2:8 v/v. The benefit of the reported approach consists in a simple sample pretreatment and a quick and sensitive hydrophilic interaction chromatography method. The developed method was validated in terms of linearity, accuracy, precision, and selectivity according to the International Conference on Harmonisation guidelines. The developed method was successfully applied for the analysis of commercial memantine tablets. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Kinetics of iron redox reactions in silicate liquids: A high-temperature X-ray absorption and Raman spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Magnien, V. [Physique des Mineraux et Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris cedex 05 (France); CEA VALRHO Marcoule, SCDV, LEBV, BP 17171, 30207 Bagnols/Ceze (France); Neuville, D.R. [Physique des Mineraux et Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris cedex 05 (France)]. E-mail: neuville@ipgp.jussieu.fr; Cormier, L. [IMPMC, CNRS UMR 7590, Universites Paris 6 and 7 and IPGP, 4 place Jussieu, 75252 Paris cedex 05 (France); Roux, J. [Physique des Mineraux et Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris cedex 05 (France); Hazemann, J.-L. [Laboratoire de cristallographie, UPR 5031, CNRS, 38043 Grenoble (France); Pinet, O. [CEA VALRHO Marcoule, SCDV, LEBV, BP 17171, 30207 Bagnols/Ceze (France); Richet, P. [Physique des Mineraux et Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris cedex 05 (France)

    2006-06-30

    The oxidation kinetics of a Fe-bearing supercooled liquid of the system SiO{sub 2}-CaO-MgO-Na{sub 2}O-FeO has been determined near the glass transition range by X-ray absorption near edge structure (XANES) and Raman spectroscopies. Both techniques yield room-temperature iron redox ratios in accord with wet chemical, Moessbauer and electron microprobe analyses. Similar oxidation kinetics have also been observed with both methods. At constant temperature, the kinetics obey an exponential law with a characteristic time that follows an Arrhenian temperature dependence. As redox changes are too fast to be accounted for in terms of diffusion of either ionic or molecular oxygen, these results lend further support to the idea that the rate-limiting factor for oxidation near the glass transition is diffusion of network-modifying cations along with a flux of electron holes.

  16. Reaction of H atoms with chelators in highly basic solution: H2 production in high level liquid waste simulants

    International Nuclear Information System (INIS)

    Barnabas, F.; Cerny, E.; Jonah, C.D.; Meisel, D.; Sauer, M.C. Jr.

    1995-01-01

    The rate constants for hydrogen abstraction by H from ethylene-diamine tetracetic acid (EDTA), N-(2-hydroxyethyl)-ethylenediaminetriacetic acid (HEDTA), nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), glycolic acid and citric acid were measured at pH 13. The predominant product of these reactions is H 2 . The rate constants obtained are more than an order of magnitude larger than the literature rates that had been measured at pH 1. These measurements are of significance for understanding the radiolytic production of H 2 in nuclear waste storage tanks. (Author)

  17. Post-column reaction for simultaneous analysis of chromatic and leuco forms of malachite green and crystal violet by high-performance liquid chromatography with photometric detection

    Science.gov (United States)

    Allen, J.L.; Meinertz, J.R.

    1991-01-01

    The chromatic and leuco forms of malachite green and crystal violet were readily separated and detected by a sensitive and selective high-performance liquid chromatographic procedure. The chromatic and leuco forms of the dyes were separated within 11 min on a C18 column with a mobile phase of 0.05 M sodium acetate and 0.05 M acetic acid in water (19%) and methanol (81%). A reaction chamber, containing 10% PbO2 in Celite 545, was placed between the column and the spectrophotometric detector to oxidize the leuco forms of the dyes to their chromatic forms. Chromatic and leuco malachite green were quantified by their absorbance at 618 nm; and chromatic and leuco Crystal Violet by their absorbance at 588 nm. Detection limits for chromatic and leuco forms of both dyes ranged from 0.12 to 0.28 ng. A linear range of 1 to 100 ng was established for both forms of the dyes.

  18. A high-performance liquid chromatography-electronic circular dichroism online method for assessing the absolute enantiomeric excess and conversion ratio of asymmetric reactions

    Science.gov (United States)

    Zhang, Xiang; Wang, Mingchao; Li, Li; Yin, Dali

    2017-03-01

    Asymmetric reactions often need to be evaluated during the synthesis of chiral compounds. However, traditional evaluation methods require the isolation of the individual enantiomer, which is tedious and time-consuming. Thus, it is desirable to develop simple, practical online detection methods. We developed a method based on high-performance liquid chromatography-electronic circular dichroism (HPLC-ECD) that simultaneously analyzes the material conversion ratio and absolute optical purity of each enantiomer. In particular, only a reverse-phase C18 column instead of a chiral column is required in our method because the ECD measurement provides a g-factor that describes the ratio of each enantiomer in the mixtures. We used our method to analyze the asymmetric hydrosilylation of β-enamino esters, and we discussed the advantage, feasibility, and effectiveness of this new methodology.

  19. Correlation between the Inhibition of Positronium Formation by Scavenger Molecules, and Chemical Reaction Rate of Electrons with these Molecules in Nonpolar Liquids

    DEFF Research Database (Denmark)

    Levay, B.; Mogensen, O. E.

    1977-01-01

    a correlation between the inhibition coefficient and the chemical rate constant of electrons with scavenger molecules. We found that the dependence of the inhibition coefficient on the work function (VOo)f electrons in different liquids shows a very unusual behavior, similar to that recently found...... for the chemical rate constants of quasifree electrons with the same scavenger molecules. The inhibition coefficient as a function of Vo had a maximum for C2HsBr, while it increased monotonously with decreasing V, for CC14. The inhibition coefficient for C2H5Br in a 1:l molar tetramethylsilane......-n-tetradecane mixture was found to be greater than in both of the pure components. The clear correlation found between electron scavenging rate constants and positronium inhibition constitutes the severest test to date of the spur reaction model of positronium formation. The importance of the positron annihilation...

  20. Rapid and accurate liquid chromatography and tandem mass spectrometry method for the simultaneous quantification of ten metabolic reactions catalyzed by hepatic cytochrome P450 enzymes.

    Science.gov (United States)

    Shi, Rong; Ma, Bingliang; Wu, Jiasheng; Wang, Tianming; Ma, Yueming

    2015-10-01

    The hepatic cytochrome P450 enzymes play a central role in the biotransformation of endogenous and exogenous substances. A sensitive high-throughput liquid chromatography with tandem mass spectrometry assay was developed and validated for the simultaneous quantification of the products of ten metabolic reactions catalyzed by hepatic cytochrome P450 enzymes. After the substrates were incubated separately, the samples were pooled and analyzed by liquid chromatography with tandem mass spectrometry using an electrospray ionization source in the positive and negative ion modes. The method exhibited linearity over a broad concentration range, insensitivity to matrix effects, and high accuracy, precision, and stability. The novel method was successfully applied to study the kinetics of phenacetin-O deethylation, coumarin-7 hydroxylation, bupropion hydroxylation, taxol-6 hydroxylation, omeprazole-5 hydroxylation, dextromethorphan-O demethylation, tolbutamide-4 hydroxylation, chlorzoxazone-6 hydroxylation, testosterone-6β hydroxylation, and midazolam-1 hydroxylation in rat liver microsomes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Influence of reaction conditions on formation of ionic liquid-based nanostructured Bi2O3 as an efficient visible-light-driven photocatalyst

    Science.gov (United States)

    Bagheri, Mozhgan; Heydari, Mojgan; Vaezi, Mohammad Reza

    2018-01-01

    In this study, nanostructured bismuth oxide was synthesized based on the chemical reaction of bismuth nitrate and NaOH in the ionic liquid 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) under ultrasonic irradiation. The effect of sodium hydroxide with a different molar ratio of NaOH to bismuth in the range of 3-10 was investigated. The results of fourier-transform infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRD) showed that NaOH has a critical role in the formation of pure α-Bi2O3. So, at high concentrations of NaOH (NaOH:Bi ≥ 7.5), the chloride anion from the ionic liquid cannot be entered into the crystalline structure of bismuth oxide, which resulted in the formation of pure bismuth oxide, while at lower concentrations of NaOH (NaOH:Bi ≤ 5), Bi3O4Cl was formed with a layered structure. The XRD results revealed that the synthesized α-Bi2O3 has a monoclinic structure and scanning electron microscopy (SEM) images showed that the sample consists of needle like particles with an average thickness of 50 nm. The ionic liquid has an important role in the prevention of an agglomeration of particles in the Bi2O3 sample. The photocatalytic activity of the synthesized Bi2O3 was investigated to study the degradation of malachite green dye as a model pollutant under visible light. The effects of various parameters such as the pH, concentration of the dye, and the catalyst on the degradation of malachite green were also investigated.

  2. Synthesis of Aluminum-Aluminum Nitride Nanocomposites by a Gas-Liquid Reaction II. Microstructure and Mechanical Properties

    Science.gov (United States)

    Borgonovo, Cecilia; Makhlouf, Makhlouf M.

    2016-04-01

    In situ fabrication of the reinforcing particles in the metal matrix is an answer to many of the challenges encountered in manufacturing aluminum matrix nanocomposites. In this method, the nanoparticles are formed directly within the melt by means of a chemical reaction between a specially designed aluminum alloy and a gas. In this publication, we describe a process for synthesizing aluminum-aluminum nitride nanocomposites by reacting a nitrogen-containing gas with a molten aluminum-lithium alloy. We quantify the effect of the process parameters on the average particle size and particle distribution, as well as on the tendency of the particles to cluster in the alloy matrix, is quantified. Also in this publication, we present the measured room temperature and elevated temperature tensile properties of the nanocomposite material as well as its measured room temperature impact toughness.

  3. Analysis of the flow with phase change and chemical reaction with the particle interaction method. Report under the contract between JNC and Toshiba Corporation

    International Nuclear Information System (INIS)

    Shirakawa, Noriyuki; Horie, Hideki; Yamamoto, Yuichi

    2001-02-01

    The numerical thermohydraulic analysis of a LMFR component should involve its whole boundary in order to evaluate the effect of chemical reaction within it. Therefore, it becomes difficult mainly due to computing time to adopt microscopic approach for the chemical reaction directly. Thus, the thermohydraulic code is required to model the chemically reactive fluid dynamics with constitutive correlations. The reaction rate depends on the binary contact areas between components such as continuous liquids, droplets, solid particles, and bubbles. The contact areas change sharply according to the interface state between components. Since no experiments to study the jet flow with sodium-water chemical reaction have been done, the goal of this study is to obtain the knowledge of flow regimes and contact areas by analyzing the fluid dynamics of multi-phase and reactive components mechanistically with the particle interaction method. In this fiscal year, following works were performed: 1) Development and coding of the interfacial area model, 2) Development and coding of the phase change model, 3) Verification of the fundamental functions of the models, and 4) Literature investigation of the related experiments. (author)

  4. Catalytic activity of hydrophobic Pt/C/PTFE catalysts of different PTFE content for hydrogen-water liquid exchange reaction

    International Nuclear Information System (INIS)

    Hu Sheng; Xiao Chengjian; Zhu Zuliang; Luo Shunzhong; Wang Heyi; Luo Yangming; Wang Changbin

    2007-01-01

    10%Pt/C catalysts were prepared by liquid reduction method. PTFE and Pt/ C catalysts were adhered to porous metal and hydrophobic Pt/C/PTFE catalysts were prepared. The structure and size of Pt crystal particles of Pt/C catalysts were analyzed by XRD, and their mean size was 3.1 nm. The dispersion state of Pt/C and PTFE was analyzed by SEM, and they had good dispersion mostly, but PTFE membrane could be observed on local parts of Pt/C/PTFE surface. Because of low hydrophobicity, Pt/C/ PTFE catalysts have low activity when the mass ratio of PTFE and Pt/C is 0.5: 1, and their catalytic activity increases markedly when the ratio is 1:1. When the ratio increases again, more Pt active sites would be covered by PTFE and interior diffusion effect would increase, which result in the decrease of catalytic activity of Pt/C/PTFE. By PTFE pretreatment of porous metal carrier, the activity of Pt/C/PTFE catalysts decreases when the mass ratio of PTFE and Pt/C is 0.5:1, and their activity decreases when the mass ratio is 1:1. (authors)

  5. Effects of compatibility of polymer binders with solvate ionic liquid electrolytes on discharge and charge reactions of lithium-sulfur batteries

    Science.gov (United States)

    Nakazawa, Toshitada; Ikoma, Ai; Kido, Ryosuke; Ueno, Kazuhide; Dokko, Kaoru; Watanabe, Masayoshi

    2016-03-01

    Electrochemical reactions in Li-S cells with a solvate ionic liquid (SIL) electrolyte composed of tetraglyme (G4) and Li[TFSA] (TFSA: bis(trifluoromethanesulfonyl)amide) are studied. The sulfur cathode (S cathode) comprises sulfur, carbon powder, and a polymer binder. Poly(ethylene oxide) (PEO) and poly(vinyl alcohol) (PVA-x) with different degrees of saponification (x%) are used as binders to prepare the composite cathodes. For the Li-S cell containing PEO binder, lithium polysulfides (Li2Sm, 2 ≤ m ≤ 8), reaction intermediates of the S cathode, dissolve into the electrolyte, and Li2Sm acts as a redox shuttle in the Li-S cell. In contrast, in the Li-S cell with PVA-x binder, the dissolution of Li2Sm is suppressed, leading to high columbic efficiencies during charge-discharge cycles. The compatibility of the PVA-x binder with the SIL electrolyte changes depending on the degree of saponification. Decreasing the degree of saponification leads to increased electrolyte uptake by the PVA-x binder, increasing the charge and discharge capacities of Li-S cell. The rate capability of Li-S cell is also enhanced by the partial swelling of the PVA-x binder. The enhanced performance of Li-S cell containing PVA-x is attributed to the lowering of resistance of Li+ ion transport in the composite cathode.

  6. Membrane Bioreactor (MBR) as Alternative to a Conventional Activated Sludge System Followed by Ultrafiltration (CAS-UF) for the Treatment of Fischer-Tropsch Reaction Water from Gas-to-Liquids Industries

    NARCIS (Netherlands)

    Laurinonyte, Judita; Meulepas, Roel J.W.; Brink, van den Paula; Temmink, Hardy

    2017-01-01

    The potential of a membrane bioreactor (MBR) system to treat Fischer-Tropsch (FT) reaction water from gas-to-liquids (GTL) industries was investigated and compared with the current treatment system: a conventional activated sludge system followed by an ultrafiltration (CAS-UF) unit. The MBR and

  7. Using ionic liquid as the solvent to prepare Pd–Ni bimetallic nanoparticles by a pyrolysis method for ethanol oxidation reaction

    International Nuclear Information System (INIS)

    Ding, Keqiang; Yang, Hongwei; Cao, Yanli; Zheng, Chunbao; Rapole, Sowjanya B.; Guo, Zhanhu

    2013-01-01

    Room temperature ionic liquids (RTILs) of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) is used as the solvent for the first time to prepare multi-walled carbon nanotubes (MWCNTs) supported nanocomposite catalysts of Pd x Ni y (atomic ratios of Pd to Ni are 1:1, 1:1.5, 1:2, and 1:2.5) nanoparticles (denoted as Pd x Ni y /MWCNTs) by using a simple pyrolysis process. The Pd x Ni y /MWCNTs catalysts are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results show that the Pd x Ni y nanoparticles (NPs) are quite uniformly dispersed on the surface of MWCNTs with an average crystallite size of ∼7.0 nm. The electro-catalytic activity of the Pd x Ni y /MWCNTs catalysts for ethanol oxidation reaction (EOR) is examined by cyclic voltammetry (CV). It is revealed that the onset potential is ∼80 mV lower and the peak current is about three times higher for ethanol oxidation for MWCNT catalysts with Pd 1 Ni 1.5 compared to those of Pd/MWCNTs. The catalytic mechanisms of the Pd 1 Ni 1.5 /MWCNTs towards EOR are also proposed and discussed. - Highlights: • Introducing ionic liquids to the pyrolysis process for the preparation of Pd x Ni y nanoparticles. • Pd x Ni y nanoparticles with an average particle size of ∼7.0 nm were fabricated. • The peak current of EOR was about three times higher at Pd 1 Ni 1.5 compared to those of Pd

  8. Preparation of a liquid nitrogen target for measurement of γ-ray in the 14N(n,γ)15N reaction as an intensity standard in energy region up to 11 MeV

    International Nuclear Information System (INIS)

    Hirano, M.; Obayashi, H.; Sakane, H.; Shibata, M.; Kawade, K.; Taniguchi, A.

    2001-01-01

    For determination of relative γ-ray intensities up to 11 MeV in the 14 N(n,γ) 15 N reaction, we have developed a liquid nitrogen (N 2 ) target which contain no hydrogen (H) to improve the accuracy of γ-ray intensities. The ratio of the relative uncertainties for the liquid nitrogen to that for the melamine (C 3 H 6 N 6 ) widely used was improved by a factor of 2 above 2.2 MeV and a factor of 3 - 6 below 2.2 MeV. It has been shown that the liquid nitrogen target is useful for reduction of the 2.2 MeV γ-ray from the 1 H(n,γ) 2 H reaction and improvement of statistics. (author)

  9. Two-dimensional molybdenum disulphide nanoflakes synthesized by liquid-solid phase reaction method: regenerative photocatalytic performance under UV-visible light irradiation by advance oxidation process

    Science.gov (United States)

    Afsar, M. F.; Rafiq, M. A.; Siddique, Fizza; Saira, F.; Chaudhary, M. M.; Hasan, M. M.; Tok, A. I. Y.

    2018-05-01

    Molybdenum disulphide (MoS2) nanoflakes were prepared through liquid-solid phase reaction technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM) analysis revealed the formation of pure, polycrystalline, hexagonal phase of MoS2 nanoflakes. The texture coefficient (T{c}hkl) analysis showed that (100) plane was preferentially oriented. The specific surface area of the nanoflakes was 21 m2 g‑1 as determined using Brunaure-Emmett-Teller (BET) technique. A band gap of ∼2.05 eV for MoS2 nanoflakes was estimated from UV-visible spectrum. Regenerative photocatalytic activity of MoS2 nanoflakes was assessed by degrading methylene blue (MB) and safranin-o (SO) dyes under UV-visible light irradiation. Under light irradiation, degradation efficiency for MB was ∼99.58% in 100 min while for SO it was ∼99.89% in 70 min. The MoS2 nanoflakes exhibited excellent photocatalytic performance and good stability in a wide pH range (3–11). MoS2 nanoflakes showed a high reaction rate constant (k app ) for SO ∼ 0.104 49 min‑1 and MB ∼ 0.092 18 min‑1 as compared to other MoS2 nanostructures. The obtained exceptional photocatalytic performance of MoS2 nanoflakes offers potential applications for the treatment of polluted water as well as in other correlated fields.

  10. Simultaneous determination of Cr(iii) and Cr(vi) using reversed-phased ion-pairing liquid chromatography with dynamic reaction cell inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Wolf, R.E.; Morrison, J.M.; Goldhaber, M.B.

    2007-01-01

    A method for the simultaneous determination of Cr(iii) and Cr(vi) species in waters, soil leachates and synthetic bio-fluids is described. The method uses reversed-phase ion-pairing liquid chromatography to separate the chromium species and a dynamic reaction cell (DRC??) equipped ICP-MS for detection of chromium. Separation of the chromium species is carried out in less than 2 min. Cr(iii) is complexed with ethylenediaminetetraacetic acid (EDTA) prior to separation by mixing samples with the mobile phase containing 2.0 mM tetrabutylammonium hydroxide (TBAOH), 0.5 mM EDTA (dipotassium salt), and 5% (vol/vol) methanol, adjusted to pH 7.6. The interfering 40Ar 12C+ background peak at mass 52 was reduced by over four orders of magnitude to less than 200 cps by using 0.65 mL min-1 ammonia as a reaction gas and an RPq setting on the DRC of 0.75. Method detection limits (MDLs) of 0.09 ??g L-1 for Cr(iii) and 0.06 ??g L-1 for Cr(vi) were obtained based on peak areas at mass 52 for 50 ??L injections of low level spikes. Reproducibility at 2 ??g L-1 was 3% RSD for 5 replicate injections. The tolerance of the method to various levels of common cations and anions found in natural waters and to matrix constituents found in soil leachates and simulated gastric and lung fluids was tested by performing spike recovery calculations for a variety of samples. ?? The Royal Society of Chemistry.

  11. Lessons from a “Failed” Experiment: Zinc Silicates with Complex Morphology by Reaction of Zinc Acetate, the Ionic Liquid Precursor (ILP Tetrabutylammonium Hydroxide (TBAH, and Glass

    Directory of Open Access Journals (Sweden)

    Andreas Taubert

    2008-08-01

    Full Text Available At elevated temperatures, the ionic liquid precursor (ILP tetrabutylammonium hydroxide reacts with zinc acetate and the glass wall of the reaction vessel. While the reaction of OH- with the glass wall is not surprising as such and could be considered a failed experiment, the resulting materials are interesting for a variety of applications. If done on purpose and under controlled conditions, the reaction with the glass wall results in uniform, well-defined hemimorphite Zn4Si2O7(OH2·nH2O and willemite Zn2SiO4 microcrystals and films. Their morphology can be adjusted by variation of the reaction time and reaction temperature. The hemimorphite can be transformed to Zn2SiO4 via calcination. The process is therefore a viable approach for the fabrication of porous films on glass surfaces with potential applications as catalyst support, among others.

  12. Analysis of phosphorus herbicides by ion-pairing reversed-phase liquid chromatography coupled to inductively coupled plasma mass spectrometry with octapole reaction cell.

    Science.gov (United States)

    Sadi, Baki B M; Vonderheide, Anne P; Caruso, Joseph A

    2004-09-24

    A reversed phase ion-pairing high performance liquid chromatographic (RPIP-HPLC) method is developed for the separation of two phosphorus herbicides, Glufosinate and Glyphosate as well as Aminomethylphosphonic acid (AMPA), the major metabolite of Glyphosate. Tetrabutylammonium hydroxide is used as the ion-pairing reagent in conjunction with an ammonium acetate/acetic acid buffering system at pH 4.7. An inductively coupled plasma mass spectrometer (ICP-MS) is coupled to the chromatographic system to detect the herbicides at m/z = 31P. Historically, phosphorus has been recognized as one of the elements difficult to analyze in argon plasma. This is due to its relatively high ionization potential (10.5 eV) as well as the inherent presence of the polyatomic interferences 14N16O1H+ and 15N16O+ overlapping its only isotope at m/z = 31. An octapole reaction cell is utilized to minimize the isobaric polyatomic interferences and to obtain the highest signal-to-background ratio. Detection limits were found to be in the low ppt range (25-32 ng/l). The developed method is successfully applied to the analysis of water samples collected from the Ohio River and spiked with a standard compounds at a level of 20 microg/l.

  13. Multiple reaction monitoring assay based on conventional liquid chromatography and electrospray ionization for simultaneous monitoring of multiple cerebrospinal fluid biomarker candidates for Alzheimer's disease.

    Science.gov (United States)

    Choi, Yong Seok; Lee, Kelvin H

    2016-03-01

    Alzheimer's disease (AD) is the most common type of dementia, but early and accurate diagnosis remains challenging. Previously, a panel of cerebrospinal fluid (CSF) biomarker candidates distinguishing AD and non-AD CSF accurately (>90 %) was reported. Furthermore, a multiple reaction monitoring (MRM) assay based on nano liquid chromatography tandem mass spectrometry (nLC-MS/MS) was developed to help validate putative AD CSF biomarker candidates including proteins from the panel. Despite the good performance of the MRM assay, wide acceptance may be challenging because of limited availability of nLC-MS/MS systems in laboratories. Thus, here, a new MRM assay based on conventional LC-MS/MS is presented. This method monitors 16 peptides representing 16 (of 23) biomarker candidates that belonged to the previous AD CSF panel. A 30-times more concentrated sample than the sample used for the previous study was loaded onto a high capacity trap column, and all 16 MRM transitions showed good linearity (average R(2) = 0.966), intra-day reproducibility (average coefficient of variance (CV) = 4.78 %), and inter-day reproducibility (average CV = 9.85 %). The present method has several advantages such as a shorter analysis time, no possibility of target variability, and no need for an internal standard.

  14. Separation and preparation of xanthochymol and guttiferone E by high performance liquid chromatography and high speed counter-current chromatography combined with silver nitrate coordination reaction.

    Science.gov (United States)

    Li, Jun; Gao, Ruixi; Zhao, Dan; Huang, Xianju; Chen, Yu; Gan, Fei; Liu, Hui; Yang, Guangzhong

    2017-08-18

    Xanthochymol (XCM) and guttiferone E (GFE), a pair of π bond benzophenone isomers from Garcinia xanthochymus, were once reported to be difficult or impossible to separate. The present study reports the successful separation of these two isomers through high performance liquid chromatography (HPLC), as well as their effective isolation using high speed counter-current chromatography (HSCCC) based on the silver nitrate (AgNO 3 ) coordination reaction. First, an effective HPLC separation system was developed, achieving a successful baseline separation with resolution of 2.0. Based on the partition coefficient (K) resolved by HPLC, the two-phase solvent system was determined as n-hexane, methanol and water with the uncommon volume ratio of 4:6:1. A crude extract of Garcinia xanthochymus (0.2g) was purified by normal HSCCC and refined with AgNO 3 -HSCCC. Monomers of XCM and GFE were identified by HPLC, mass spectrometry (MS) and nuclear magnetic resonance (NMR). The results demonstrate the separation and isolation of π bond benzophenone isomers using ordinary octadecyl silane (C 18 ) columns and HSCCC. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Quantification of methionine and selenomethionine in biological samples using multiple reaction monitoring high performance liquid chromatography tandem mass spectrometry (MRM-HPLC-MS/MS).

    Science.gov (United States)

    Vu, Dai Long; Ranglová, Karolína; Hájek, Jan; Hrouzek, Pavel

    2018-05-01

    Quantification of selenated amino-acids currently relies on methods employing inductively coupled plasma mass spectrometry (ICP-MS). Although very accurate, these methods do not allow the simultaneous determination of standard amino-acids, hampering the comparison of the content of selenated versus non-selenated species such as methionine (Met) and selenomethionine (SeMet). This paper reports two approaches for the simultaneous quantification of Met and SeMet. In the first approach, standard enzymatic hydrolysis employing Protease XIV was applied for the preparation of samples. The second approach utilized methanesulfonic acid (MA) for the hydrolysis of samples, either in a reflux system or in a microwave oven, followed by derivatization with diethyl ethoxymethylenemalonate. The prepared samples were then analyzed by multiple reaction monitoring high performance liquid chromatography tandem mass spectrometry (MRM-HPLC-MS/MS). Both approaches provided platforms for the accurate determination of selenium/sulfur substitution rate in Met. Moreover the second approach also provided accurate simultaneous quantification of Met and SeMet with a low limit of detection, low limit of quantification and wide linearity range, comparable to the commonly used gas chromatography mass spectrometry (GC-MS) method or ICP-MS. The novel method was validated using certified reference material in conjunction with the GC-MS reference method. Copyright © 2018. Published by Elsevier B.V.

  16. Liquid chromatography-electrospray ionization tandem mass spectrometry and dynamic multiple reaction monitoring method for determining multiple pesticide residues in tomato.

    Science.gov (United States)

    Andrade, G C R M; Monteiro, S H; Francisco, J G; Figueiredo, L A; Botelho, R G; Tornisielo, V L

    2015-05-15

    A quick and sensitive liquid chromatography-electrospray ionization tandem mass spectrometry method, using dynamic multiple reaction monitoring and a 1.8-μm particle size analytical column, was developed to determine 57 pesticides in tomato in a 13-min run. QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for samples preparations and validations was carried out in compliance with EU SANCO guidelines. The method was applied to 58 tomato samples. More than 84% of the compounds investigated showed limits of detection equal to or lower than 5 mg kg(-1). A mild (50%) matrix effect was observed for 72%, 25%, and 3% of the pesticides studied, respectively. Eighty-one percent of the pesticides showed recoveries ranging between 70% and 120%. Twelve pesticides were detected in 35 samples, all below the maximum residue levels permitted in the Brazilian legislation; 15 samples exceeded the maximum residue levels established by the EU legislation for methamidophos; and 10 exceeded limits for acephate and four for bromuconazole. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Direct analysis of prostaglandin-E2 and -D2 produced in an inflammatory cell reaction and its application for activity screening and potency evaluation using turbulent flow chromatography liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Shin, Jeong-Sook; Peng, Lei; Kang, Kyungsu; Choi, Yongsoo

    2016-09-09

    Direct analysis of prostaglandin-E2 (PGE2) and -D2 (PGD2) produced from a RAW264.7 cell-based reaction was performed by liquid chromatography high-resolution mass spectrometry (LC-HRMS), which was online coupled with turbulent flow chromatography (TFC). The capability of this method to accurately measure PG levels in cell reaction medium containing cytokines or proteins as a reaction byproduct was cross-validated by two conventional methods. Two methods, including an LC-HRMS method after liquid-liquid extraction (LLE) of the sample and a commercial PGE2 enzyme-linked immunosorbent assay (ELISA), showed PGE2 and/or PGD2 levels almost similar to those obtained by TFC LC-HRMS over the reaction time after LPS stimulation. After the cross-validation, significant analytical throughputs, allowing simultaneous screening and potency evaluation of 80 natural products including 60 phytochemicals and 20 natural product extracts for the inhibition of the PGD2 produced in the cell-based inflammatory reaction, were achieved using the TFC LC-HRMS method developed. Among the 60 phytochemicals screened, licochalcone A and formononetin inhibited PGD2 production the most with IC50 values of 126 and 151nM, respectively. For a reference activity, indomethacin and diclofenac were used, measuring IC50 values of 0.64 and 0.21nM, respectively. This method also found a butanol extract of Akebia quinata Decne (AQ) stem as a promising natural product for PGD2 inhibition. Direct and accurate analysis of PGs in the inflammatory cell reaction using the TFC LC-HRMS method developed enables the high-throughput screening and potency evaluation of as many as 320 samples in less than 48h without changing a TFC column. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Liquid helium target

    International Nuclear Information System (INIS)

    Fujii, Y.; Kitami, T.; Torikoshi, M.

    1984-12-01

    A liquid helium target system has been built and used for the experiment on the reaction 4 He(γ, p). The target system has worked satisfactorily; the consumption rate of liquid helium is 360 ml/h and the cryogenic system retains liquid helium for about ten hours. The structure, operation and performance of the target system are reported. (author)

  19. Reporter-free potentiometric sensing of boronic acids and their reactions by using quaternary ammonium salt-functionalized polymeric liquid membranes.

    Science.gov (United States)

    Wang, Xuewei; Yue, Dengfeng; Lv, Enguang; Wu, Lei; Qin, Wei

    2014-02-18

    The tremendous applications of boronic acids (BAs) in chemical sensing, medical chemistry, molecular assembly, and organic synthesis lead to an urgent demand for developing effective sensing methods for BAs. This paper reports a facile and sensitive potentiometric sensor scheme for heterogeneous detection of BAs based on their unexpected potential responses on quaternary ammonium salt-doped polymeric liquid membranes. (11)B NMR data reveal that a quaternary ammonium chloride can trigger the hydrolysis of an electrically neutral BA in an aprotic solvent. Using the quaternary ammonium salt as the receptor, the BA molecules can be extracted from the sample solution into the polymeric membrane phase and undergo the concomitant hydrolysis. Such salt-triggered hydrolysis generates H(+) ions, which can be coejected into the aqueous phase with the counterions (e.g., Cl(-)) owing to their high hydrophilicities. The perturbation on the ionic partition at the sample-membrane interface changes the phase boundary potential and thus enables the potentiometric sensing of BAs. In contrast to other transduction methods for BAs, for which labeled or separate reporters are exclusively required, the present heterogeneous sensing scheme allows the direct detection of BAs without using any reporter molecules. This technique shows superior detection limits for BAs (e.g., 1.0 × 10(-6) M for phenylboronic acid) as compared to previously reported methods based on colorimetry, fluorimetry, and mass spectrometry. The proposed sensing strategy has also been successfully applied to potentiometric indication of the BA reactions with hydrogen peroxide and saccharides, which allows indirect and sensitive detection of these important species.

  20. Implications of small water leak reactions on sodium heated steam generator design

    Energy Technology Data Exchange (ETDEWEB)

    Smedley, J A

    1975-07-01

    Various types of sodium water reactions have been looked on as possibly causing hazard conditions in sodium heated steam generator units ranging from the very improbable boiler tube double ended guillotine fracture to the almost certain occurrence of micro-leaks. Within this range small water leaks reactions have attracted particular interest and the present paper looks at the principles of associating the reactions with detection and protection systems for Commercial Fast Reactors. A method is developed for assessing whether adequate protection has been provided against the effects of small water leak reactions in a steam generator unit. (author)

  1. Chemical transport reactions

    CERN Document Server

    Schäfer, Harald

    2013-01-01

    Chemical Transport Reactions focuses on the processes and reactions involved in the transport of solid or liquid substances to form vapor phase reaction products. The publication first offers information on experimental and theoretical principles and the transport of solid substances and its special applications. Discussions focus on calculation of the transport effect of heterogeneous equilibria for a gas motion between equilibrium spaces; transport effect and the thermodynamic quantities of the transport reaction; separation and purification of substances by means of material transport; and

  2. PREFACE: Functionalized Liquid Liquid Interfaces

    Science.gov (United States)

    Girault, Hubert; Kornyshev, Alexei A.; Monroe, Charles W.; Urbakh, Michael

    2007-09-01

    Most natural processes take place at interfaces. For this reason, surface science has been a focal point of modern research. At solid-liquid interfaces one can induce various species to adsorb or react, and thus may study interactions between the substrate and adsorbates, kinetic processes, optical properties, etc. Liquid-liquid interfaces, formed by immiscible liquids such as water and oil, have a number of distinctive features. Both sides of the interface are amenable to detailed physical and chemical analysis. By chemical or electrochemical means, metal or semiconductor nanoparticles can be formed or localised at the interface. Surfactants can be used to tailor surface properties, and also to place organic molecular or supermolecular constructions at the boundary between the liquids. Electric fields can be used to drive ions from one fluid to another, or even change the shape of the interface itself. In many cases, both liquids are optically transparent, making functionalized liquid-liquid interfaces promising for various optical applications based on the transmission or reflection of light. An advantage common to most of these systems is self-assembly; because a liquid-liquid interface is not mechanically constrained like a solid-liquid interface, it can easily access its most stable state, even after it has been driven far from equilibrium. This special issue focuses on four modes of liquid-liquid interfacial functionalization: the controlled adsorption of molecules or nanoparticles, the formation of adlayers or films, electrowetting, and ion transfer or interface-localized reactions. Interfacial adsorption can be driven electrically, chemically, or mechanically. The liquid-liquid interface can be used to study how anisotropic particles orient at a surface under the influence of a field, how surfactants interact with other adsorbates, and how nanoparticles aggregate; the transparency of the interface also makes the chirality of organic adsorbates amenable to

  3. Liquid metal steam generator

    International Nuclear Information System (INIS)

    Wolowodiuk, W.

    1975-01-01

    A liquid metal heated steam generator is described which in the event of a tube failure quickly exhausts out of the steam generator the products of the reaction between the water and the liquid metal. The steam is generated in a plurality of bayonet tubes which are heated by liquid metal flowing over them between an inner cylinder and an outer cylinder. The inner cylinder extends above the level of liquid metal but below the main tube sheet. A central pipe extends down into the inner cylinder with a centrifugal separator between it and the inner cylinder at its lower end and an involute deflector plate above the separator so that the products of a reaction between the liquid metal and the water will be deflected downwardly by the deflector plate and through the separator so that the liquid metal will flow outwardly and away from the central pipe through which the steam and gaseous reaction products are exhausted. (U.S.)

  4. Functionalized dicationic ionic liquids: Green and efficient ...

    Indian Academy of Sciences (India)

    have the advantages of liquid and solid phase together.11. Task-specific ionic liquids ... more attention as alternative reaction media in green chemistry than conventional ..... The reaction mixture was divided into two. Figure 3. Reusability of ...

  5. EPA CRL MS014: Analysis of Aldicarb, Bromadiolone, Carbofuran, Oxamyl and Methomyl in Water by Multiple Reaction Monitoring Liquid Chromatography / Tandem Mass Spectrometry (LC/MS/MS)

    Science.gov (United States)

    Method MS014 describes procedures for solvent extraction of aldicarb, bromadiolone, carbofuran, oxamyl and methomyl from water samples, followed by analysis using liquid chromatography tandem mass spectrometry (LC-MS-MS).

  6. Liquids and liquid mixtures

    CERN Document Server

    Rowlinson, J S; Baldwin, J E; Buckingham, A D; Danishefsky, S

    2013-01-01

    Liquids and Liquid Mixtures, Third Edition explores the equilibrium properties of liquids and liquid mixtures and relates them to the properties of the constituent molecules using the methods of statistical thermodynamics. Topics covered include the critical state, fluid mixtures at high pressures, and the statistical thermodynamics of fluids and mixtures. This book consists of eight chapters and begins with an overview of the liquid state and the thermodynamic properties of liquids and liquid mixtures, including vapor pressure and heat capacities. The discussion then turns to the thermodynami

  7. PEG1000-Based Dicationic Acidic Ionic Liquid Catalyzed One-Pot Synthesis of 4-Aryl-3-Methyl-1-Phenyl-1H-Benzo[h]pyrazolo [3,4-b]quinoline-5,10-Diones via Multicomponent Reactions

    Directory of Open Access Journals (Sweden)

    Yi-Ming Ren

    2015-09-01

    Full Text Available A novel and green approach for efficient and rapid synthesis of 4-aryl-3-methyl-1-phenyl-1H-benzo[h]pyrazolo[3,4-b]quinoline-5,10-diones has been accomplished by the one-pot condensation reaction of aromatic aldehydes, 3-methyl-1-phenyl-1H-pyrazol-5-amine and 2-hydroxynaphthalene-1,4-dione using PEG1000-based dicationic acidic ionic liquid (PEG1000-DAIL as a catalyst was reported. Recycling studies have shown that the PEG1000-DAIL can be readily recovered and reused several times without significant loss of activity. The key advantages are the short reaction time, high yields, simple workup, and recovered catalyst.

  8. Correction of effects due to reactions on complex nuclei in a sample of hydrogen-like antiproton annihilations from a heavy liquid bubble chamber experiment

    International Nuclear Information System (INIS)

    Fett, E.; Haatuft, A.; Olsen, J.M.

    1977-01-01

    A method is presented, which has been used to determine the pion multiplicity distributions for antiproton annihilations on free protons from a sample of events obtained in a heavy liquid bubble chamber experiment. The method uses data obtained in the experiment in question together with the usual invariance principles satisfied by strong interactions. Furthermore no particular nuclear model is assumed

  9. Selective on-line detection of boronic acids and derivatives in high-performance liquid chromatography eluates by post-column reaction with alizarin

    NARCIS (Netherlands)

    Duval, F.L.; Wardani, P.A.; Zuilhof, H.; Beek, van T.A.

    2015-01-01

    An on-line high-performance liquid chromatography (HPLC) method for the rapid and selective detection of boronic acids in complex mixtures was developed. After optimization experiments at an HPLC flow rate of 0.40 mL/min, the HPLC-separated analytes were mixed post-column with a solution of 75 µM

  10. Simultaneous Transformation of Commingled Trichloroethylene, Tetrachloroethylene, and 1,4-Dioxane by a Microbially Driven Fenton Reaction in Batch Liquid Cultures

    Science.gov (United States)

    Sekar, Ramanan; Taillefert, Martial

    2016-01-01

    ABSTRACT Improper disposal of 1,4-dioxane and the chlorinated organic solvents trichloroethylene (TCE) and tetrachloroethylene (also known as perchloroethylene [PCE]) has resulted in widespread contamination of soil and groundwater. In the present study, a previously designed microbially driven Fenton reaction system was reconfigured to generate hydroxyl (HO˙) radicals for simultaneous transformation of source zone levels of single, binary, and ternary mixtures of TCE, PCE, and 1,4-dioxane. The reconfigured Fenton reaction system was driven by fed batch cultures of the Fe(III)-reducing facultative anaerobe Shewanella oneidensis amended with lactate, Fe(III), and contaminants and exposed to alternating anaerobic and aerobic conditions. To avoid contaminant loss due to volatility, the Fe(II)-generating, hydrogen peroxide-generating, and contaminant transformation phases of the microbially driven Fenton reaction system were separated. The reconfigured Fenton reaction system transformed TCE, PCE, and 1,4-dioxane either as single contaminants or as binary and ternary mixtures. In the presence of equimolar concentrations of PCE and TCE, the ratio of the experimentally derived rates of PCE and TCE transformation was nearly identical to the ratio of the corresponding HO˙ radical reaction rate constants. The reconfigured Fenton reaction system may be applied as an ex situ platform for simultaneous degradation of commingled TCE, PCE, and 1,4-dioxane and provides valuable information for future development of in situ remediation technologies. IMPORTANCE A microbially driven Fenton reaction system [driven by the Fe(III)-reducing facultative anaerobe S. oneidensis] was reconfigured to transform source zone levels of TCE, PCE, and 1,4-dioxane as single contaminants or as binary and ternary mixtures. The microbially driven Fenton reaction may thus be applied as an ex situ platform for simultaneous degradation of at least three (and potentially more) commingled contaminants

  11. Hantzsch reaction and quinoxaline synthesis using 1-methyl-3-(2-(sulfooxyethyl-1H-imidazol-3-ium chloride as a new, efficient and BrØnsted acidic ionic liquid catalyst

    Directory of Open Access Journals (Sweden)

    Sami Sajjadifar

    2013-10-01

    Full Text Available In this work, the efficiency, generality and applicability of new BrØnsted acidic ionic liquid (BAIL 1-methyl-3-(2-(sulfooxyethyl-1H-imidazol-3-ium chloride {[Msei]Cl} as heterogeneous and green catalyst for organic transformations are studied. Herein, the following one-pot multi-component reactions in the presence of [Msei]Cl are investigated: (i the synthesis of quinoxaline derivatives from the reaction of phenylenediamines and 1,2-diketones in EtOH under mild conditions (room temperature, (ii the preparation of 1,4-dihydropyridines from one-pot multi component condensation of 1,3-dicarbonyl compounds, NH4OAcand aldehydes under solvent-free conditions at moderate temperature (90 °C. High yields, relatively short reaction times, efficiency, generality, clean process, simple methodology, low cost, easy work-up, ease of preparation and regeneration of the catalyst and green conditions (in the synthesis of the quinoxaline derivatives are advantages of the application of [Mesi]Cl as catalyst in the above organic reactions.

  12. Liquid state sup1H and sup13C-NMR studies on polymerisation reaction of 2,2'-difurfuryloxy-2- silapropane

    International Nuclear Information System (INIS)

    Rusli bin Omar

    1994-01-01

    The purpose of this study was to prepare the copolymer of 2,2'-difurfuryloxy-2-silapropane (DFS) and 1,1'-(methylenedi-4, 1-phenylene) bismaleimide (BM). DFS was prepared at 0 degC through the reaction of 2 moles of furfuryl alcohol (FA) with 1 mole of dichlorodimethylsilane (DCMS) in the presence of pyridine and chloroform as a solvent. The formation of this compound was characterized by the sup1H and sup13C-NMR spectroscopy and mass spectrometry. DFS has the ability to undergo the Diels-Alder reaction. The furan end groups of DFS could react with dienophile groups of other materials. The adduct of DFS-BM was prepared by the reaction of DFS with BM at room temperature (18degC) in chloroform (CDClsub3). Characterization of the adduct was carried out through a study of the sup1H and sup13C-NMR spectra of the adduct

  13. Gas to liquid to solid transition in halogen hot atom chemistry. 6. Product formation routes and chemical selectivity of high energy iodine reactions with butyne isomers

    International Nuclear Information System (INIS)

    Garmestani, S.K.; Firouzbakht, M.L.; Rack, E.P.

    1979-01-01

    Reactions of recoil produced iodine-128 with isomers of butyne were studied in gaseous, high pressure, and condensed phase conditions, with rare gas additives and in the presence and absence of radical scavengers (I 2 and O 2 ). It was found that recoil iodine-128 reactions were initiated by thermal electronically excited I + species for both 1-butyne and 2-butyne systems. While the diverse and complex nature of the reactions cannot be explained by simple chemical parameters, comparisons among the alkyne systems demonstrate preferential attack of iodine at the triple bond resulting, mainly, in electronically excited intermediates. A comparison of the various product formation routes results in the characterization of general traits common to the alkynes. 6 figures, 4 tables

  14. Correction: Zielinski, W., et al. Ionic Liquids as Solvents for Rhodium and Platinum Catalysts Used in Hydrosilylation Reaction. Molecules 2016, 21, 1115

    Directory of Open Access Journals (Sweden)

    Witold Zielinski

    2017-07-01

    Full Text Available The authors are sorry to report that the yield of the hydrosilylation reaction in [P44414][NTf2] (1 IL with [RhCl(PPh33] was replaced with the yield reported for [P44414][NTf2] (1 IL with K2PtCl4 in their published paper [1]. [...

  15. Integration of On-Column Chemical Reactions in Protein Characterization by Liquid Chromatography/Mass Spectrometry: Cross-Path Reactive Chromatography.

    Science.gov (United States)

    Pawlowski, Jake W; Carrick, Ian; Kaltashov, Igor A

    2018-01-16

    Profiling of complex proteins by means of mass spectrometry (MS) frequently requires that certain chemical modifications of their covalent structure (e.g., reduction of disulfide bonds), be carried out prior to the MS or MS/MS analysis. Traditionally, these chemical reactions take place in the off-line mode to allow the excess reagents (the majority of which interfere with the MS measurements and degrade the analytical signal) to be removed from the protein solution prior to MS measurements. In addition to a significant increase in the analysis time, chemical reactions may result in a partial or full loss of the protein if the modifications adversely affect its stability, e.g,, making it prone to aggregation. In this work we present a new approach to solving this problem by carrying out the chemical reactions online using the reactive chromatography scheme on a size exclusion chromatography (SEC) platform with MS detection. This is achieved by using a cross-path reaction scheme, i.e., by delaying the protein injection onto the SEC column (with respect to the injection of the reagent plug containing a disulfide-reducing agent), which allows the chemical reactions to be carried out inside the column for a limited (and precisely controlled) period of time, while the two plugs overlap inside the column. The reduced protein elutes separately from the unconsumed reagents, allowing the signal suppression in ESI to be avoided and enabling sensitive MS detection. The new method is used to measure fucosylation levels of a plasma protein haptoglobin at the whole protein level following online reduction of disulfide-linked tetrameric species to monomeric units. The feasibility of top-down fragmentation of disulfide-containing proteins is also demonstrated using β 2 -microglobulin and a monoclonal antibody (mAb). The new online technique is both robust and versatile, as the cross-path scheme can be readily expanded to include multiple reactions in a single experiment (as

  16. Gas to liquid to solid transition in halogen hot atom chemistry. II. Systematics of bromine reactions activated by radiative neutron capture and isomeric transition with halomethanes

    International Nuclear Information System (INIS)

    Berg, M.E.; Grauer, W.M.; Helton, R.W.; Rack, E.P.

    1975-01-01

    Bromine reactions activated by 79 Br(n,γ) 80 Br, 81 Br(n,γ)/sup 82m/Br + 82 Br, and /sup 82m/Br(I.T.) 82 Br nuclear transformations were studied in halomethanes as functions of mole fraction of Br 2 , phase, density, and intermolecular distance. Gas phase systematics coupled with the density and mole fraction of Br 2 studies demonstrate the existence of systematic trends in the condensed phases as evidenced by the Richardson--Wolfgang effect. A definitive difference due to activation that is independent of system and suggests the importance of caging at higher densities is shown by the variation of total and individual organic product yields with density. The study of total organic product yield vs. intermolecular distance provides both a means of separating cage and molecular reactions and suggests the importance of molecular properties in the caging event. (U.S.)

  17. Synthesis of novel room temperature chiral ionic liquids: application as reaction media for the heck arylation of aza-endocyclic acrylates

    Energy Technology Data Exchange (ETDEWEB)

    Pastre, Julio C.; Correia, Carlos R.D., E-mail: genisson@chimie.ups-tlse.f, E-mail: roque@iqm.unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica; Genisson, Yves [Universite Paul Sabatier, Toulouse (France). Lab. de Synthese et Physicochimie des Molecules d' Interet Biologique; Saffon, Nathalie [Universite Paul Sabatier, Toulouse (France). Structure federative toulousaine en chimie moleculaire (SFTCM); Dandurand, Jany [Universite Paul Sabatier, Toulouse (France). Lab. de Physique des Polymeres

    2010-07-01

    New achiral and chiral RTILs were prepared using novel and/or optimized synthetic routes. These new series of imidazolinium, imidazolium, pyridinium and nicotine-derived ionic liquids were fully characterized including differential scanning calorimetry (DSC) analysis. The performance of these achiral and chiral room temperature ionic liquids (RTILs) was demonstrated by means of the Heck arylation of endocyclic acrylates employing arenediazonium salts and aryl iodides. The Heck arylations performed in the presence of these ionic entities, either as a solvent or as an additive, were effective leading to complete conversion of the substrate and good to excellent yield of the Heck adduct. In spite of the good performances, no asymmetric induction was observed in any of the cases studied. Two new diastereoisomeric NHC-palladium complexes were prepared in good yields from a chiral imidazolium salt and their structure characterized by X-ray diffraction. Overall, the Heck arylations employing arenediazonium tetrafluoroborates in RTILs were more effective than the traditional protocols employing aryl iodides in terms of reactivity and yields. (author)

  18. Macromolecular sensing at the liquid-liquid interface

    Energy Technology Data Exchange (ETDEWEB)

    Herzog, Gregoire; Flynn, Shane [Tyndall National Institute, Lee Maltings, University College, Cork (Ireland); Arrigan, Damien W M, E-mail: gregoire.herzog@tyndall.ie [Nanochemistry Research Institute, Department of Chemistry, Curtin University, Perth (Australia)

    2011-08-17

    We report here the electrochemical sensing of macromolecules, such as polyLysine dendrimers, at the polarised liquid | liquid interface. Electrochemistry at the liquid | liquid interface is a powerful analytical technique which allows the detection of non-redox active molecules via ion transfer reactions at a polarised water - oil interface. We demonstrate here that different parameters of the polyLysine dendrimers (charge number, molecular weight) have a strong influence on the sensitivity and limit of detection of these macromolecules. This work will help to the development of sensors based on charge transfer at the liquid | liquid interface.

  19. Macromolecular sensing at the liquid-liquid interface

    International Nuclear Information System (INIS)

    Herzog, Gregoire; Flynn, Shane; Arrigan, Damien W M

    2011-01-01

    We report here the electrochemical sensing of macromolecules, such as polyLysine dendrimers, at the polarised liquid | liquid interface. Electrochemistry at the liquid | liquid interface is a powerful analytical technique which allows the detection of non-redox active molecules via ion transfer reactions at a polarised water - oil interface. We demonstrate here that different parameters of the polyLysine dendrimers (charge number, molecular weight) have a strong influence on the sensitivity and limit of detection of these macromolecules. This work will help to the development of sensors based on charge transfer at the liquid | liquid interface.

  20. Measurement of 103mRh produced by the 103Rh(γ,γ')103mRh reaction with liquid scintillation counting

    International Nuclear Information System (INIS)

    Sekine, T.; Yoshihara, Kenji; Pavlicsek, I.; Lakosi, L.; Veres, A.

    1989-01-01

    A liquid scintillation counting technique was applied to measure the isotope 103m Rh (half life = 56.12 min) which is difficult to detect because its γ-ray is of low energy and low emission probability. Tris-(2,4-pentanedionato)rhodium(III) (Rh(acac) 3 ) was irradiated with bremsstrahlung of accelerated 3.2 MeV electrons by LINAC. The method has given a reliable calibration curve for the determination of 103m Rh radioactivity below Rh(acac) 3 concentrations of 2 mM. The integrated cross section of 103 Rh(γ,γ') 103m Rh determined by this method was found to be 6.8±3.4 μb MeV at 3.2 MeV. (author) 8 refs.; 5 figs

  1. Asymmetric aza-Diels-Alder reaction of Danishefsky's diene with imines in a chiral reaction medium

    Directory of Open Access Journals (Sweden)

    Pégot Bruce

    2006-09-01

    Full Text Available Abstract The asymmetric aza-Diels-Alder reaction of chiral imines with Danishefsky's diene in chiral ionic liquids provides the corresponding cycloadduct with moderate to high diastereoselectivity. The reaction has proved to perform better at room temperature in ionic liquids without either Lewis acid catalyst or organic solvent. Chiral ionic liquids are recycled while their efficiency is preserved.

  2. Mass transfer with chemical reaction in multiphase systems

    International Nuclear Information System (INIS)

    Alper, E.

    1983-01-01

    These volumes deal with the phenomenon of 'mass transfer with chemical reaction' which is of industrial, biological and physiological importance. In process engineering, it is encountered both in separation processes and in reaction engineering and both aspects are covered here in four sections: introduction; gas-liquid system; liquid-liquid system; and gas-liquid-solid system

  3. Chemistry of nuclear recoil 18F atoms. VIII. Mechanisms and yields of caging reactions in liquid phase 1,1-difluoroethane and 1,1,1-trifluoroethane

    International Nuclear Information System (INIS)

    Manning, R.G.; Root, J.W.

    1976-01-01

    New procedures are reported for the specification of caging yields in nuclear recoil chemistry experiments. All five hot 18 F substitution channels in CH 3 CF 3 and CH 3 CHF 2 exhibit caging at large density. The respective total caged yields at 195 degreeK are 4.0% +- 0.6% and 5.6% +- 0.6%, and the total yields of stabilized substitution products are 8.9% +- 0.4% and 8.6% +- 0.6%. The simplest plausible caging mechanism involves primary Franck--Rabinowitsch radical recombination of 18 F atoms with aliphatic radicals. Density-variation results cannot be used for the qualitative detection of caging reactions unless excitation-stabilization complications have been shown to be unimportant

  4. One-step liquid phase chemical method to prepare carbon-based amorphous molybdenum sulfides: As the effective hydrogen evolution reaction catalysts

    International Nuclear Information System (INIS)

    Guo, Mengmeng; Wu, Qikang; Yu, Miaomiao; Wang, Yinling; Li, Maoguo

    2017-01-01

    Two different kinds of carbon-based amorphous molybdenum sulfide composite catalysts (activated carbon supported amorphous molybdenum sulfide and acetylene black supported amorphous molybdenum sulfide) had been prepared in a facile and scalable one-step liquid phase chemical method. The morphological and structural information of catalysts was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and it’s electro-catalytic HER activity were evaluated by linear sweep voltammetry(LSV), amperometric i-t technology and AC impedance technology. The as-prepared carbon-based amorphous molybdenum sulfides showed greatly enhanced electro-catalytic activity for HER compared with pure amorphous molybdenum sulfides. Especially, the nano-sized acetylene black supported molybdenum sulfide exhibited excellent electro-catalytic HER performances with a low onset potential of −116 mV versus reverse hydrogen electrode (RHE) and a small Tafel slope of 51 mV per decade.

  5. Ionic liquid-tolerant cellulase enzymes

    Science.gov (United States)

    Gladden, John; Park, Joshua; Singer, Steven; Simmons, Blake; Sale, Ken

    2017-10-31

    The present invention provides ionic liquid-tolerant cellulases and method of producing and using such cellulases. The cellulases of the invention are useful in saccharification reactions using ionic liquid treated biomass.

  6. Liquid sodium technology research

    International Nuclear Information System (INIS)

    Kim, W.C.; Lee, Y.W.; Nam, H.Y.; Chun, S.Y.; Kim, J.; Won, S.Y.

    1982-01-01

    This report describes the technology of impurity control and measurement of liquid sodium, problems associated with material degradation and change of heat transfer characteristics in liquid sodium, and the conceptual design of multipurpose sodium test loop. Discussion and the subsequent analysis are also made with regard to the test results for the sodium-H 2 0 reaction and its effects on the system. (author)

  7. High-performance liquid chromatographic method to evaluate the hydrogen atom transfer during reaction between 1,1-diphenyl-2-picryl-hydrazyl radical and antioxidants

    International Nuclear Information System (INIS)

    Boudier, Ariane; Tournebize, Juliana; Bartosz, Grzegorz; El Hani, Safae; Bengueddour, Rachid; Sapin-Minet, Anne; Leroy, Pierre

    2012-01-01

    Highlights: ► Both 1,1-diphenyl-2-picrylhydrazyl radical and its product measurement by HPLC. ► Lowest limit of detection by monitoring 1,1-diphenyl-2-picryl-hydrazine. ► Adsorption problem of the radical on HPLC parts have been pointed out. - Abstract: 1,1-Diphenyl-2-picrylhydrazyl (DPPH·) is a stable nitrogen centred radical widely used to evaluate direct radical scavenging properties of various synthetic or natural antioxidants (AOs). The bleaching rate of DPPH· absorbance at 515 nm is usually monitored for this purpose. In order to avoid the interference of complex coloured natural products used as antioxidant supplements or cosmetics, HPLC systems have been reported as alternative techniques to spectrophotometry. They also rely upon measurement of DPPH· quenching rate and none of them permits to identify and measure 1,1-diphenyl-2-picryl-hydrazine (DPPH-H), the reduced product of DPPH· resulting from hydrogen atom transfer (HAT), which is the main mechanism of the reaction between DPPH· and AOs. We presently report an HPLC method devoted to the simultaneous measurement of DPPH· and DPPH-H. Both were fully separated on a C18 column eluted with acetonitrile–10 mM ammonium citrate buffer pH 6.8 (70:30, v/v) and detected at 330 nm. Adsorption process of DPPH· onto materials of the HPLC system was pointed out. Consequently, the linearity range observed for DPPH· was restricted, thus a much lower limit of detection was obtained for DPPH-H than for DPPH· using standards (0.02 and 14 μM, respectively). The method was applied to three commonly used AOs, i.e. Trolox ® , ascorbic acid and GSH, and compared with spectrophotometry. Further application to complex matrices (cell culture media, vegetal extracts) and nanomaterials demonstrated (i) its usefulness because of higher selectivity than colorimetry, and (ii) its help to investigate the mechanisms occurring with the free radical.

  8. Complexation reactions in pyridine and 2,6-dimethylpyridine-water system: The quantum-chemical description and the path to liquid phase separation

    Science.gov (United States)

    Chernia, Zelig; Tsori, Yoav

    2018-03-01

    Phase separation in substituted pyridines in water is usually described as an interplay between temperature-driven breakage of hydrogen bonds and the associating interaction of the van der Waals force. In previous quantum-chemical studies, the strength of hydrogen bonding between one water and one pyridine molecules (the 1:1 complex) was assigned a pivotal role. It was accepted that the disassembly of the 1:1 complex at a critical temperature leads to phase separation and formation of the miscibility gap. Yet, for over two decades, notable empirical data and theoretical arguments were presented against that view, thus revealing the need in a revised quantum-mechanical description. In the present study, pyridine-water and 2,6-dimethylpyridine-water systems at different complexation stages are calculated using high level Kohn-Sham theory. The hydrophobic-hydrophilic properties are accounted for by the polarizable continuum solvation model. Inclusion of solvation in free energy of formation calculations reveals that 1:1 complexes are abundant in the organically rich solvents but higher level oligomers (i.e., 2:1 dimers with two pyridines and one water molecule) are the only feasible stable products in the more polar media. At the critical temperature, the dissolution of the external hydrogen bonds between the 2:1 dimer and the surrounding water molecules induces the demixing process. The 1:1 complex acts as a precursor in the formation of the dimers but is not directly involved in the demixing mechanism. The existence of the miscibility gap in one pyridine-water system and the lack of it in another is explained by the ability of the former to maintain stable dimerization. Free energy of formation of several reaction paths producing the 2:1 dimers is calculated and critically analyzed.

  9. Liquid metal pump

    International Nuclear Information System (INIS)

    Pennell, W.E.

    1981-01-01

    A liquid metal pump comprising a shaft support structure which is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft carries an impeller and the support structure carries an impeller cage which is slidably disposed in a diffuser so as to allow complete removal of pump internals for inspection and repair. The diffuser is concentrically supported in the pump housing which also takes up all reaction forces generated by the discharge of the liquid metal from the diffuser, with floating seals arranged between impeller cage and the diffuser. The space between the diffuser and the pump housing permits the incoming liquid to essentially surround the diffuser. (author)

  10. High-performance liquid chromatographic method to evaluate the hydrogen atom transfer during reaction between 1,1-diphenyl-2-picryl-hydrazyl radical and antioxidants

    Energy Technology Data Exchange (ETDEWEB)

    Boudier, Ariane; Tournebize, Juliana [CITHEFOR - EA 3452, Faculte de Pharmacie, Nancy-Universite, 5 Rue Albert Lebrun, BP 80403, 54001 Nancy Cedex (France); Bartosz, Grzegorz [Department of Molecular Biophysics, University of Lodz, Lodz (Poland); El Hani, Safae; Bengueddour, Rachid [Laboratoire de Nutrition et Sante, Biology Department, Faculty of Sciences, Ibn Tofail University, Kenitra (Morocco); Sapin-Minet, Anne [CITHEFOR - EA 3452, Faculte de Pharmacie, Nancy-Universite, 5 Rue Albert Lebrun, BP 80403, 54001 Nancy Cedex (France); Leroy, Pierre, E-mail: pierre.leroy@pharma.uhp-nancy.fr [CITHEFOR - EA 3452, Faculte de Pharmacie, Nancy-Universite, 5 Rue Albert Lebrun, BP 80403, 54001 Nancy Cedex (France)

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer Both 1,1-diphenyl-2-picrylhydrazyl radical and its product measurement by HPLC. Black-Right-Pointing-Pointer Lowest limit of detection by monitoring 1,1-diphenyl-2-picryl-hydrazine. Black-Right-Pointing-Pointer Adsorption problem of the radical on HPLC parts have been pointed out. - Abstract: 1,1-Diphenyl-2-picrylhydrazyl (DPPH{center_dot}) is a stable nitrogen centred radical widely used to evaluate direct radical scavenging properties of various synthetic or natural antioxidants (AOs). The bleaching rate of DPPH{center_dot} absorbance at 515 nm is usually monitored for this purpose. In order to avoid the interference of complex coloured natural products used as antioxidant supplements or cosmetics, HPLC systems have been reported as alternative techniques to spectrophotometry. They also rely upon measurement of DPPH{center_dot} quenching rate and none of them permits to identify and measure 1,1-diphenyl-2-picryl-hydrazine (DPPH-H), the reduced product of DPPH{center_dot} resulting from hydrogen atom transfer (HAT), which is the main mechanism of the reaction between DPPH{center_dot} and AOs. We presently report an HPLC method devoted to the simultaneous measurement of DPPH{center_dot} and DPPH-H. Both were fully separated on a C18 column eluted with acetonitrile-10 mM ammonium citrate buffer pH 6.8 (70:30, v/v) and detected at 330 nm. Adsorption process of DPPH{center_dot} onto materials of the HPLC system was pointed out. Consequently, the linearity range observed for DPPH{center_dot} was restricted, thus a much lower limit of detection was obtained for DPPH-H than for DPPH{center_dot} using standards (0.02 and 14 {mu}M, respectively). The method was applied to three commonly used AOs, i.e. Trolox{sup Registered-Sign }, ascorbic acid and GSH, and compared with spectrophotometry. Further application to complex matrices (cell culture media, vegetal extracts) and nanomaterials demonstrated (i) its usefulness because of

  11. Use of micro-emulsions in liquid-liquid extraction

    International Nuclear Information System (INIS)

    Komornicki, Jacques

    1982-01-01

    As liquid-liquid extraction of metallic cations is an important method of separation and concentration of metals present in diluted aqueous solutions, and as the extraction rate is limited by one or several steps of matter transfer at the liquid-liquid interface, the extraction kinetics can be improved by creating a wide surface interface and by allowing an increased reactivity between species. In this research thesis, the author aims at determining to which extent systems of interface with a wide surface obtained by using for example amphiphile molecules to create micro-emulsions, can be used as reaction media for physical-chemical processes of liquid-liquid extraction. He also aims at identifying their applicability limitations and problems which might arise with their application. The author notably focuses of the liquid-liquid extraction of metallic cations exhibiting particularly slow extraction kinetics

  12. Liquid chromatography coupled to quadrupole-time of flight tandem mass spectrometry based quantitative structure-retention relationships of amino acid analogues derivatized via n-propyl chloroformate mediated reaction.

    Science.gov (United States)

    Kritikos, Nikolaos; Tsantili-Kakoulidou, Anna; Loukas, Yannis L; Dotsikas, Yannis

    2015-07-17

    In the current study, quantitative structure-retention relationships (QSRR) were constructed based on data obtained by a LC-(ESI)-QTOF-MS/MS method for the determination of amino acid analogues, following their derivatization via chloroformate esters. Molecules were derivatized via n-propyl chloroformate/n-propanol mediated reaction. Derivatives were acquired through a liquid-liquid extraction procedure. Chromatographic separation is based on gradient elution using methanol/water mixtures from a 70/30% composition to an 85/15% final one, maintaining a constant rate of change. The group of examined molecules was diverse, including mainly α-amino acids, yet also β- and γ-amino acids, γ-amino acid analogues, decarboxylated and phosphorylated analogues and dipeptides. Projection to latent structures (PLS) method was selected for the formation of QSRRs, resulting in a total of three PLS models with high cross-validated coefficients of determination Q(2)Y. For this reason, molecular structures were previously described through the use of descriptors. Through stratified random sampling procedures, 57 compounds were split to a training set and a test set. Model creation was based on multiple criteria including principal component significance and eigenvalue, variable importance, form of residuals, etc. Validation was based on statistical metrics Rpred(2),QextF2(2),QextF3(2) for the test set and Roy's metrics rm(Av)(2) and rm(δ)(2), assessing both predictive stability and internal validity. Based on aforementioned models, simplified equivalent were then created using a multi-linear regression (MLR) method. MLR models were also validated with the same metrics. The suggested models are considered useful for the estimation of retention times of amino acid analogues for a series of applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Ionic Liquid-Assisted Synthesis of Nanoscale (MoS2)x(SnO2)1-x on Reduced Graphene Oxide for the Electrocatalytic Hydrogen Evolution Reaction.

    Science.gov (United States)

    Ravula, Sudhir; Zhang, Chi; Essner, Jeremy B; Robertson, J David; Lin, Jian; Baker, Gary A

    2017-03-08

    Layered transition metal dichalcogenides (TMDs) have attracted increased attention due to their enhanced hydrogen evolution reaction (HER) performance. More specifically, ternary TMD nanohybrids, such as MoS 2(1-x) Se 2x or bimetallic sulfides, have arisen as promising electrocatalysts compared to MoS 2 and MoSe 2 due to their electronic, morphologic, and size tunabilities. Herein, we report the successful synthesis of few-layered MoS 2 /rGO, SnS 2 /rGO, and (MoS 2 ) x (SnO 2 ) 1-x /rGO nanohybrids anchored on reduced graphene oxide (rGO) through a facile hydrothermal reaction in the presence of ionic liquids as stabilizing, delayering agents. Spectroscopic and microscopic techniques (electron microscopy, X-ray diffraction, Raman spectroscopy, neutron activation analysis, and UV-vis spectrophotometry) are used to validate the hierarchical properties, phase identity, and the smooth compositional tunability of the (MoS 2 ) x (SnO 2 ) 1-x /rGO nanohybrids. Linear sweep voltammetry measurements reveal that incorporation of Sn into the ternary nanohybrids (as a discrete SnO 2 phase) greatly reduces the overpotential by 90-130 mV relative to the MoS 2 electrocatalyst. Significantly, the (MoS 2 ) 0.6 (SnO 2 ) 0.4 /rGO nanohybrid displays superior catalytic performance over MoS 2 alone, exhibiting a low overpotential (η 10 ) of 263 ± 5 mV and a small Tafel slope of 50.8 mV dec -1 . The hybrid catalyst shows high stability for the HER in acidic solutions, with negligible activity loss after 1000 cycles. The hierarchical structures and large surface areas possessing exposed, active edge sites make few-layered (MoS 2 ) x (SnO 2 ) 1-x /rGO nanohybrids promising nonprecious metal electrocatalysts for the HER.

  14. On the Chemical Stabilities of Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Yen-Ho Chu

    2009-09-01

    Full Text Available Ionic liquids are novel solvents of interest as greener alternatives to conventional organic solvents aimed at facilitating sustainable chemistry. As a consequence of their unusual physical properties, reusability, and eco-friendly nature, ionic liquids have attracted the attention of organic chemists. Numerous reports have revealed that many catalysts and reagents were supported in the ionic liquid phase, resulting in enhanced reactivity and selectivity in various important reaction transformations. However, synthetic chemists cannot ignore the stability data and intermolecular interactions, or even reactions that are directly applicable to organic reactions in ionic liquids. It is becoming evident from the increasing number of reports on use of ionic liquids as solvents, catalysts, and reagents in organic synthesis that they are not totally inert under many reaction conditions. While in some cases, their unexpected reactivity has proven fortuitous and in others, it is imperative that when selecting an ionic liquid for a particular synthetic application, attention must be paid to its compatibility with the reaction conditions. Even though, more than 200 room temperature ionic liquids are known, only a few reports have commented their effects on reaction mechanisms or rate/stability. Therefore, rather than attempting to give a comprehensive overview of ionic liquid chemistry, this review focuses on the non-innocent nature of ionic liquids, with a decided emphasis to clearly illuminate the ability of ionic liquids to affect the mechanistic aspects of some organic reactions thereby affecting and promoting the yield and selectivity.

  15. On the chemical stabilities of ionic liquids.

    Science.gov (United States)

    Sowmiah, Subbiah; Srinivasadesikan, Venkatesan; Tseng, Ming-Chung; Chu, Yen-Ho

    2009-09-25

    Ionic liquids are novel solvents of interest as greener alternatives to conventional organic solvents aimed at facilitating sustainable chemistry. As a consequence of their unusual physical properties, reusability, and eco-friendly nature, ionic liquids have attracted the attention of organic chemists. Numerous reports have revealed that many catalysts and reagents were supported in the ionic liquid phase, resulting in enhanced reactivity and selectivity in various important reaction transformations. However, synthetic chemists cannot ignore the stability data and intermolecular interactions, or even reactions that are directly applicable to organic reactions in ionic liquids. It is becoming evident from the increasing number of reports on use of ionic liquids as solvents, catalysts, and reagents in organic synthesis that they are not totally inert under many reaction conditions. While in some cases, their unexpected reactivity has proven fortuitously advantageous in others is has been a problem, it is imperative that when selecting an ionic liquid for a particular synthetic application, attention be paid to its compatibility with the reaction conditions. Even though, more than 200 room temperature ionic liquids are known, only a few reports have commented their effects on reaction mechanisms or rate/stability. Therefore, rather than attempting to give a comprehensive overview of ionic liquid chemistry, this review focuses on the non-innocent nature of ionic liquids, with a decided emphasis to clearly illuminate the ability of ionic liquids to affect the mechanistic aspects of some organic reactions thereby affecting and promoting the yield and selectivity.

  16. Comparison of pharmacokinetic behavior of two iridoid glycosides in rat plasma after oral administration of crude Cornus officinals and its jiuzhipin by high performance liquid chromatography triple quadrupole mass spectrometry combined with multiple reactions monitoring mode

    Science.gov (United States)

    Chen, Xiaocheng; Cao, Gang; Jiang, Jianping

    2014-01-01

    Objective: The present study examined the pharmacokinetic profiles of two iridoid glycosides named morroniside and loganin in rat plasma after oral administration of crude and processed Cornus officinals. Materials and Methods: A rapid, selective and specific high-performance liquid chromatography/electrospray ionization tandem mass spectrometry with multiple reactions monitoring mode was developed to simultaneously investigate the pharmacokinetic profiles of morroniside and loganin in rat plasma after oral administration of crude C. officinals and its jiuzhipin. Results: The morroniside and loganin in crude and processed C. officinals could be simultaneously determined within 7.4 min. Linear calibration curves were obtained over the concentration ranges of 45.45-4800 ng/mL for all the analytes. The intra-and inter-day precisions relative standard deviation was lesser than 2.84% and 4.12%, respectively. Conclusion: The pharmacokinetic parameters of two iridoid glucosides were also compared systematically between crude and processed C. officinals. This paper provides the theoretical proofs for further explaining the processing mechanism of Traditional Chinese Medicines. PMID:24914290

  17. Reactor for exothermic reactions

    Science.gov (United States)

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1993-03-02

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  18. Static gas-liquid interfacial direct current discharge plasmas using ionic liquid cathode

    International Nuclear Information System (INIS)

    Kaneko, T.; Baba, K.; Hatakeyama, R.

    2009-01-01

    Due to the unique properties of ionic liquids such as their extremely low vapor pressure and high heat capacity, we have succeeded in creating the static and stable gas (plasmas)-liquid (ionic liquids) interfacial field using a direct current discharge under a low gas pressure condition. It is clarified that the ionic liquid works as a nonmetal liquid electrode, and furthermore, a secondary electron emission coefficient of the ionic liquid is larger than that of conventional metal electrodes. The plasma potential structure of the gas-liquid interfacial region, and resultant interactions between the plasma and the ionic liquid are revealed by changing a polarity of the electrode in the ionic liquid. By utilizing the ionic liquid as a cathode electrode, the positive ions in the plasma region are found to be irradiated to the ionic liquid. This ion irradiation causes physical and chemical reactions at the gas-liquid interfacial region without the vaporization of the ionic liquid.

  19. Modeling of Reaction Calorimeter

    OpenAIRE

    Farzad, Reza

    2014-01-01

    The purpose of this project was to model the reaction calorimeter in order to calculate the heat of absorption which is the most important parameter in this work. Reaction calorimeter is an apparatus which is used in measuring the heat of absorption of CO2 as well as the total pressure in vapor phase based on vapor-liquid equilibrium state. Mixture of monoethanolamine (MEA) and water was used as a solvent to absorb the CO2.Project was divided in to three parts in order to make the programming...

  20. Ionic Liquids in Tribology

    Directory of Open Access Journals (Sweden)

    Ichiro Minami

    2009-06-01

    Full Text Available Current research on room-temperature ionic liquids as lubricants is described. Ionic liquids possess excellent properties such as non-volatility, non-flammability, and thermo-oxidative stability. The potential use of ionic liquids as lubricants was first proposed in 2001 and approximately 70 articles pertaining to fundamental research on ionic liquids have been published through May 2009. A large majority of the cations examined in this area are derived from 1,3-dialkylimidazolium, with a higher alkyl group on the imidazolium cation being beneficial for good lubrication, while it reduces the thermo-oxidative stability. Hydrophobic anions provide both good lubricity and significant thermo-oxidative stability. The anions decompose through a tribochemical reaction to generate metal fluoride on the rubbed surface. Additive technology to improve lubricity is also explained. An introduction to tribology as an interdisciplinary field of lubrication is also provided.

  1. Ionic liquids in tribology.

    Science.gov (United States)

    Minami, Ichiro

    2009-06-24

    Current research on room-temperature ionic liquids as lubricants is described. Ionic liquids possess excellent properties such as non-volatility, non-flammability, and thermo-oxidative stability. The potential use of ionic liquids as lubricants was first proposed in 2001 and approximately 70 articles pertaining to fundamental research on ionic liquids have been published through May 2009. A large majority of the cations examined in this area are derived from 1,3-dialkylimidazolium, with a higher alkyl group on the imidazolium cation being beneficial for good lubrication, while it reduces the thermo-oxidative stability. Hydrophobic anions provide both good lubricity and significant thermo-oxidative stability. The anions decompose through a tribochemical reaction to generate metal fluoride on the rubbed surface. Additive technology to improve lubricity is also explained. An introduction to tribology as an interdisciplinary field of lubrication is also provided.

  2. Photochemical reaction dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Moore, B.C. [Lawrence Berkeley Laboratory, Livermore, CA (United States)

    1993-12-01

    The purpose of the program is to develop a fundamental understanding of unimolecular and bimolecular reaction dynamics with application in combustion and energy systems. The energy dependence in ketene isomerization, ketene dissociation dynamics, and carbonyl substitution on organometallic rhodium complexes in liquid xenon have been studied. Future studies concerning unimolecular processes in ketene as well as energy transfer and kinetic studies of methylene radicals are discussed.

  3. Reactions and Interactions in Liquid Crystalline Media

    Science.gov (United States)

    1991-10-30

    nematic lyophases of potassium laurate, myristyl tri methylammonium bromide or sodium decylsulfate with 1-decanol and 23 water. A strong retardation of the...crystalline polyacrylate crosslinked elastomers were synthesized. 198c 0 0 96 0 0 0O-(CH12 ) 2 -0O(k 97 Crosslinking, up to 10% of structural units produced...in their isotropic state and they work as the transporting phase for the azo-crown ether molecules. The permeation of K+ from a potassium p

  4. Supported Ionic Liquid Phase (SILP) catalysis

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Haumann, Marco

    2006-01-01

    Applications of ionic liquids to replace conventional solvents in homogeneous transition-metal catalysis have increased significantly during the last decade. Biphasic ionic liquid/organic liquid systems offer advantages with regard to product separation, catalyst stability, and recycling...... but utilise in the case of fast chemical reactions only a small amount of expensive ionic liquid and catalyst. The novel Supported Ionic Liquid Phase (SILP) catalysis concept overcomes these drawbacks and allows the use of fixed-bed reactors for continuous reactions. In this Microreview the SILP catalysis...

  5. Identification of known chemicals and their metabolites from Alpinia oxyphylla fruit extract in rat plasma using liquid chromatography/tandem mass spectrometry (LC-MS/MS) with selected reaction monitoring.

    Science.gov (United States)

    Chen, Feng; Li, Hai-Long; Tan, Yin-Feng; Li, Yong-Hui; Lai, Wei-Yong; Guan, Wei-Wei; Zhang, Jun-Qing; Zhao, Yuan-Sheng; Qin, Zhen-Miao

    2014-08-01

    Alpinia oxyphylla (Yizhi) capsularfruits are commonly used in traditional medicine. Pharmacological studies have demonstrated that A. oxyphylla capsularfruits have some beneficial roles. Besides volatile oil, sesquiterpenes, diarylheptanoids and flavonoids are main bioactive constituents occurring in the Yizhi capsularfruits. The representative constituents include tectochrysin, izalpinin, chrysin, apigenin-4',7-dimethylether, kaempferide, yakuchinone A, yakuchinone B, oxyphyllacinol and nootkatone. Their content levels in the fruit and its pharmaceutical preparations have been reported by our group. The nine phytochemicals are also the major components present in the Yizhi alcoholic extracts, which have anti-diarrheal activities. However, the fates of these constituents in the body after oral or intravenous administration remain largely unknown. In the present study, we focus on these phytochemicals albeit other concomitant compounds. The chemicals and their metabolites in rat plasma were identified using liquid chromatography/tandem mass spectrometry with selected reaction monitoring mode after orally administered Yizhi extract to rats. Rat plasma samples were treated by methanol precipitation, acidic or enzymatic hydrolysis. This target analysis study revealed that: (1) low or trace plasma levels of parent chemicals were measured after p.o. administration of Yizhi extract, Suoquan capsules and pills to rats; (2) flavonoids and diarylheptanoids formed mainly monoglucuronide metabolites; however, diglucuronide metabolites for chrysin, izalpinin and kaempferide were also detected; (3) metabolic reduction of Yizhi diarylheptanoids occurred in rats. Yakuchinone B was reduced to yakuchinone A and then to oxyphyllacinol in a stepwise manner and subsequently glucuronidated by UDP-glucuronosyl transferase. Further research is needed to characterize the UDP-glucuronosyl transferase and reductase involved in the biotransformation of Yizhi chemicals. Copyright © 2014

  6. Nuclear reactions

    International Nuclear Information System (INIS)

    Lane, A.M.

    1980-01-01

    In reviewing work at Harwell over the past 25 years on nuclear reactions it is stated that a balance has to be struck in both experiment and theory between work on cross-sections of direct practical relevance to reactors and on those relevant to an overall understanding of reaction processes. The compound nucleus and direct process reactions are described. Having listed the contributions from AERE, Harwell to developments in nuclear reaction research in the period, work on the optical model, neutron capture theory, reactions at doorway states with fine structure, and sum-rules for spectroscopic factors are considered in more detail. (UK)

  7. Proceedings of the specialists' meeting on acoustic/ultrasonic detection of in sodium water leaks on steam generators, held in Aix-en-Provence, France, 1-3 October 1990

    International Nuclear Information System (INIS)

    Girard, J.P.

    1990-10-01

    23 officially nominated persons and 8 observers from 7 countries operating fast breeder reactors in the world, Mr. Arkhipov, IAEA Scientific Secretary of IWGFR and Mr. Cambillard, French member of IWGFR attended the specialists meeting. 25 papers were presented in the national status session and in 3 technical sessions devoted to methods, theoretical approach and real steam generator experience. A separate abstract was prepared for each of these papers. Since the last meetings in Dimitrovgrad and Petten it is clear that acoustic/ultrasonic monitoring of in-sodium water leaks is now considered by all countries as a major topic for commercial fast reactor steam generator unit protection. At this time the detection of leakage events is thought to be possible in the leak range from 1 to about 100 g/s in a time period of a few seconds to a few tens of seconds. Future work should aim at a more precise definition of the attainable limits, taking into account the particular requirements of actual plant design. Refs, figs and tabs

  8. Laser- synthesis of metal sulphides in sulphurous liquids

    International Nuclear Information System (INIS)

    Markevich, M.I.; Podoltsev, A.S.; Piskunov, F.A.; Yanushkevich, V.A.

    2001-01-01

    Laser processing of materials in chemically reactive surrounding mediums has been marked with growing interest, using a pulsed laser in conjunction with a proper liquid makes it possible to induce rapid and often non - equilibrium reactions at the solid-liquid interface. It is believed that temperature, pressure and phase transformations in the liquid are the key parameters necessary to understand the interface reactions

  9. LIQUID-LIQUID EXTRACTION COLUMNS

    Science.gov (United States)

    Thornton, J.D.

    1957-12-31

    This patent relates to liquid-liquid extraction columns having a means for pulsing the liquid in the column to give it an oscillatory up and down movement, and consists of a packed column, an inlet pipe for the dispersed liquid phase and an outlet pipe for the continuous liquid phase located in the direct communication with the liquid in the lower part of said column, an inlet pipe for the continuous liquid phase and an outlet pipe for the dispersed liquid phase located in direct communication with the liquid in the upper part of said column, a tube having one end communicating with liquid in the lower part of said column and having its upper end located above the level of said outlet pipe for the dispersed phase, and a piston and cylinder connected to the upper end of said tube for applying a pulsating pneumatic pressure to the surface of the liquid in said tube so that said surface rises and falls in said tube.

  10. The chemistry of the liquid alkali metals

    International Nuclear Information System (INIS)

    Addison, C.C.

    1984-01-01

    A study of liquid alkali metals. It encourages comparison with molecular solvents in chapter covering the nature and reactivity of dissolved species, solvation, solubility and electrical conductivity of solutions. It demonstrates lab techniques unique to liquid alkali metals. It discusses large-scale applications from storage batteries to sodium-cooled reactors and future fusion reactors, and associated technological problems. Contents: Some Basic Physical and Chemical Properties; Manipulation of the Liquids; The Chemistry of Purification Methods; Species Formed by Dissolved Elements; Solubilities and Analytical Methods; Alkali Metal Mixtures; Solvation in Liquid Metal; Reactions Between Liquid Alkali Metals and Water; Reactions of Nitrogen with Lithium and the Group II Metals in Liquid Sodium; The Formation, Dissociation and Stability of Heteronuclear Polyatomic Anions; Reactions of the Liquid Alkali Metals and Their Alloys with Simple Alipatic Hydrocarbons; Reactions of the Liquid Alkali Metals with Some Halogen Compounds; Hydrogen, Oxygen and Carbon Meters; Surface Chemistry and Wetting; Corrosion of Transition Metals by the Liquid Alkali Metals; Modern Applications of the Liquid Alkali Metals

  11. Decontamination liquid waste processing method

    International Nuclear Information System (INIS)

    Enda, Masami; Hosaka, Katsumi.

    1992-01-01

    Liquid wastes after electrolytic reduction are caused to flow through an anionic exchange membrane in a diffusion dialysis step, and liquid wastes and dialyzed water are passed in a countercurrent manner. Since acids in the liquid wastes transfer on the side of the dialyzed water due to the difference of concentration between the liquid wastes and the dialyzed water, acids can be easily recovered from the liquid wastes. If the acid-removed liquid wastes are put to electrodeposition in an electrodepositing step, the electrodepositing reactions between radioactive materials such as Co ion, Mn ion and leached metals such as Fe ions and Cr ions are caused preferentially to hydrogen generation reaction on a metal deposition cathode. Accordingly, metal ions can be easily separated from the liquid wastes. Since the separated liquid wastes are an aqueous solution in which cerium ions as a decontaminant and an acid at low concentration are dissolved, the concentration thereof is controlled by mixing them to acid recovering water after the diffusion dialysis and they can be reused as the decontaminant. (T.M.)

  12. Ionization in liquids

    International Nuclear Information System (INIS)

    Bakale, G.

    1990-01-01

    During the 1987--1990 reporting period, studies were conducted that entailed the direct measurement of the transport and reaction properties of excess electrons in nonpolar liquids through the use of pulse-conductivity techniques. The results obtained from these studies should be applicable toward the development of a better understanding of the primary ionizing event in liquids as well as to providing physico-chemical information that is pertinent to electron-transfer processes that are ubiquitous in biological systems. Progress was also made in developing a better understanding of electron attachment reactions in liquids through measurements of the electron attachment rate constants, k e s, of a variety of electron-attaching solutes. The effects of several functional groups substituted at different positions on benzene were studied in liquid cyclohexane and isooctane. The electron-attaching properties of chemicals having well characterized carcinogenic properties were studied in cyclohexane to determine if the measure of electron-accepting potential that k e provides can elucidate the role that electrons play in the initiation step of carcinogenesis. The k e s that were measured indicate that the k e -carcinogenicity correlation that was observed can be used to complement short-term carcinogen-screening bioassays to identify potential carcinogens. 115 refs., 6 tabs

  13. Liquid Ventilation

    Directory of Open Access Journals (Sweden)

    Qutaiba A. Tawfic

    2011-01-01

    Full Text Available Mammals have lungs to breathe air and they have no gills to breath liquids. When the surface tension at the air-liquid interface of the lung increases, as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen, as the inert carrier of oxygen and carbon dioxide offers a number of theoretical advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. The potential for multiple clinical applications for liquid-assisted ventilation will be clarified and optimized in future. Keywords: Liquid ventilation; perfluorochemicals; perfluorocarbon; respiratory distress; surfactant.

  14. Subsidizing Liquidity

    DEFF Research Database (Denmark)

    Malinova, Katya; Park, Andreas

    2015-01-01

    the breakdown of trading fees between liquidity demanders and suppliers matters. Posted quotes adjust after the change in fee composition, but the transaction costs for liquidity demanders remain unaffected once fees are taken into account. However, as posted bid-ask spreads decline, traders (particularly......Facing increased competition over the last decade, many stock exchanges changed their trading fees to maker-taker pricing, an incentive scheme that rewards liquidity suppliers and charges liquidity demanders. Using a change in trading fees on the Toronto Stock Exchange, we study whether and why...... retail) use aggressive orders more frequently, and adverse selection costs decrease....

  15. Quasielastic reactions

    International Nuclear Information System (INIS)

    Henning, W.

    1979-01-01

    Quasielastic reaction studies, because of their capability to microscopically probe nuclear structure, are still of considerable interest in heavy-ion reactions. The recent progress in understanding various aspects of the reaction mechanism make this aim appear closer. The relation between microscopic and macroscopic behavior, as suggested, for example, by the single proton transfer data to individual final states or averaged excitation energy intervals, needs to be explored. It seems particularly useful to extend measurements to higher incident energies, to explore and understand nuclear structure aspects up to the limit of the energy range where they are important

  16. Lipid processing in ionic liquids

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Guo, Zheng; Xu, Xuebing

    2007-01-01

    Ionic liquids (ILs) have been touted as “green” alternatives to traditional molecular solvents and have many unique properties which make them extremely desirable substitutes. Among their most attractive properties are their lack of vapour pressure, broad liquid range, strong solvating power and ...... and the ability to tailor properties of individual ILs to meet specific requirements. This article highlights current research as well as the vast potential of ILs for use as media for reactions, separation and processing in the lipid area....

  17. cycloaddition reactions

    Indian Academy of Sciences (India)

    Unknown

    Molecular Modeling Group, Organic Chemical Sciences, Indian Institute of Chemical Technology,. Hyderabad ... thus obtained are helpful to model the regioselectivity ... compromise to model Diels–Alder reactions involving ...... acceptance.

  18. Liquidity Runs

    NARCIS (Netherlands)

    Matta, R.; Perotti, E.

    2016-01-01

    Can the risk of losses upon premature liquidation produce bank runs? We show how a unique run equilibrium driven by asset liquidity risk arises even under minimal fundamental risk. To study the role of illiquidity we introduce realistic norms on bank default, such that mandatory stay is triggered

  19. Managing liquidity

    DEFF Research Database (Denmark)

    Pokutta, Sebastian; Schmaltz, Christian

    2011-01-01

    Large banking groups face the question of how to optimally allocate and generate liquidity: in a central liquidity hub or in many decentralized branches. We translate this question into a facility location problem under uncertainty. We show that volatility is the key driver behind (de......-)centralization. We provide an analytical solution for the 2-branch model and show that a liquidity center can be interpreted as an option on immediate liquidity. Therefore, its value can be interpreted as the price of information, i.e., the price of knowing the exact demand. Furthermore, we derive the threshold...... above which it is advantageous to open a liquidity center and show that it is a function of the volatility and the characteristic of the bank network. Finally, we discuss the n-branch model for real-world banking groups (10-60 branches) and show that it can be solved with high granularity (100 scenarios...

  20. Direct Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Austern, N. [University of Pittsburgh, Pittsburgh, PA (United States)

    1963-01-15

    In order to give a unified presentation of one point of view, these lectures are devoted only to a detailed development of the standard theories of direct reactions, starting from basic principles. Discussion is given of the present status of the theories, of the techniques used for practical calculation, and of possible future developments. The direct interaction (DI) aspects of a reaction are those which involve only a few of the many degrees of freedom of a nucleus. In fact the minimum number of degrees of freedom which must be involved in a reaction are those required to describe the initial and final channels, and DI studies typically consider these degrees of freedom and no others. Because of this simplicity DI theories may be worked out in painstaking detail. DI processes concern only part of the wave function for a problem. The other part involves complicated excitations of many degrees of freedom, and gives the compound nucleus (CN) effects. While it is extremely interesting to learn how to separate DI and CN effects in an orderly manner, if they are both present in a reaction, no suitable method has yet been found. Instead, current work stresses the kinds of reactions and the kinds of final states in which DI effects dominate and in which CN effects may almost be forgotten. The DI cross-sections which are studied are often extremely large, comparable to elastic scattering cross-sections. (author)

  1. Reaction mechanisms

    International Nuclear Information System (INIS)

    Nguyen Trong Anh

    1988-01-01

    The 1988 progress report of the Reaction Mechanisms laboratory (Polytechnic School, France), is presented. The research topics are: the valence bond methods, the radical chemistry, the modelling of the transition states by applying geometric constraints, the long range interactions (ion - molecule) in gaseous phase, the reaction sites in gaseous phase and the mass spectroscopy applications. The points of convergence between the investigations of the mass spectroscopy and the theoretical chemistry teams, as well as the purposes guiding the research programs, are discussed. The published papers, the conferences, the congress communications and the thesis, are also reported [fr

  2. Liquid metal reactor development -Studies on safety measure of LMR coolant

    International Nuclear Information System (INIS)

    Hwang, Sung Tae; Choi, Yoon Dong; Park, Jin Hoh; Kwon, Sun Kil; Choi, Jong Hyun; Cho, Byung Ryul; Kim, Tae Joon; Kwon, Sang Woon; Jung, Kyung Chae; Kim, Byung Hoh; Hong, Soon Bok; Jung, Ji Yung

    1995-07-01

    A study on the safety measures of LMR coolant showed the results as follows; 1. LMR coolant safety measure. A. Analysis and improvement of sodium fire code. B. Analysis of sodium fire phenomena. 2. Sodium fire aerosol characteristics. It was carried out conceptual design and basic design for sodium fire facility of medium size composed of sodium supply tank, sodium reactor vessel, sodium fire aerosol filter system and scrubbing column, and drain tank etc. 3. Sodium purification technology. A. Construction of calibration loop. (1) Design of sodium loop for the calibration of the equipment. (2) Construction of sodium loop including test equipments and other components. B. Na-analysis technology. (1) Oxygen concentration determination by the wet method. (2) Cover gas purification preliminary experiment. 4. The characteristics of sodium-water reaction. A. Analysis of the micro and small leak phenomena. (1) Manufacture of the micro-leak test apparatus. B. Analysis of large leak events. (1) Development of preliminary code for analysis of initial spike pressure. (2) Sample calculation and comparison with previous works. C. Development of test facility for large leak event evaluation. (1) Conceptional and basic design for the water and sodium-water test facility. D. Technology development for water leak detection system. (1) Investigations for the characteristics of active acoustic detection system. (2) Testing of the characteristics of hydrogen leak detection system. 171 figs, 29 tabs, 3 refs. (Author)

  3. Liquid metal reactor development -Studies on safety measure of LMR coolant

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Sung Tae; Choi, Yoon Dong; Park, Jin Hoh; Kwon, Sun Kil; Choi, Jong Hyun; Cho, Byung Ryul; Kim, Tae Joon; Kwon, Sang Woon; Jung, Kyung Chae; Kim, Byung Hoh; Hong, Soon Bok; Jung, Ji Yung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-07-01

    A study on the safety measures of LMR coolant showed the results as follows; 1. LMR coolant safety measure. A. Analysis and improvement of sodium fire code. B. Analysis of sodium fire phenomena. 2. Sodium fire aerosol characteristics. It was carried out conceptual design and basic design for sodium fire facility of medium size composed of sodium supply tank, sodium reactor vessel, sodium fire aerosol filter system and scrubbing column, and drain tank etc. 3. Sodium purification technology. A. Construction of calibration loop. (1) Design of sodium loop for the calibration of the equipment. (2) Construction of sodium loop including test equipments and other components. B. Na-analysis technology. (1) Oxygen concentration determination by the wet method. (2) Cover gas purification preliminary experiment. 4. The characteristics of sodium-water reaction. A. Analysis of the micro and small leak phenomena. (1) Manufacture of the micro-leak test apparatus. B. Analysis of large leak events. (1) Development of preliminary code for analysis of initial spike pressure. (2) Sample calculation and comparison with previous works. C. Development of test facility for large leak event evaluation. (1) Conceptional and basic design for the water and sodium-water test facility. D. Technology development for water leak detection system. (1) Investigations for the characteristics of active acoustic detection system. (2) Testing of the characteristics of hydrogen leak detection system. 171 figs, 29 tabs, 3 refs. (Author).

  4. Fuel gas production by microwave plasma in liquid

    International Nuclear Information System (INIS)

    Nomura, Shinfuku; Toyota, Hiromichi; Tawara, Michinaga; Yamashita, Hiroshi; Matsumoto, Kenya

    2006-01-01

    We propose to apply plasma in liquid to replace gas-phase plasma because we expect much higher reaction rates for the chemical deposition of plasma in liquid than for chemical vapor deposition. A reactor for producing microwave plasma in a liquid could produce plasma in hydrocarbon liquids and waste oils. Generated gases consist of up to 81% hydrogen by volume. We confirmed that fuel gases such as methane and ethylene can be produced by microwave plasma in liquid

  5. Allergic reactions

    Science.gov (United States)

    ... that don't bother most people (such as venom from bee stings and certain foods, medicines, and pollens) can ... person. If the allergic reaction is from a bee sting, scrape the ... more venom. If the person has emergency allergy medicine on ...

  6. Liquid explosives

    CERN Document Server

    Liu, Jiping

    2015-01-01

    The book drawing on the author's nearly half a century of energetic materials research experience intends to systematically review the global researches on liquid explosives. The book focuses on the study of the conception, explosion mechanism, properties and preparation of liquid explosives. It provides a combination of theoretical knowledge and practical examples in a reader-friendly style. The book is likely to be interest of university researchers and graduate students in the fields of energetic materials, blasting engineering and mining.

  7. Supported ionic liquid-phase (SILP) catalysis

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Wasserscheid, P.

    2005-01-01

    The concept of supported ionic liquid-phase (SILP) catalysis has been demonstrated for gas- and liquid-phase continuous fixed-bed reactions using rhodium phosphine catalyzed hydroformylation of propene and 1-octene as examples. The nature of the support had important influence on both the catalytic...

  8. Modelling the liquidity ratio as macroprudential instrument

    OpenAIRE

    Jan Willem van den End; Mark Kruidhof

    2012-01-01

    The Basel III Liquidity Coverage Ratio (LCR) is a microprudential instrument to strengthen the liquidity position of banks. However, if in extreme scenarios the LCR becomes a binding constraint, the interaction of bank behaviour with the regulatory rule can have negative externalities. We simulate the systemic implications of the LCR by a liquidity stress-testing model, which takes into account the impact of bank reactions on second round feedback effects. We show that a flexible approach of ...

  9. On the Chemical Stabilities of Ionic Liquids

    OpenAIRE

    Yen-Ho Chu; Ming-Chung Tseng; Venkatesan Srinivasadesikan; Subbiah Sowmiah

    2009-01-01

    Ionic liquids are novel solvents of interest as greener alternatives to conventional organic solvents aimed at facilitating sustainable chemistry. As a consequence of their unusual physical properties, reusability, and eco-friendly nature, ionic liquids have attracted the attention of organic chemists. Numerous reports have revealed that many catalysts and reagents were supported in the ionic liquid phase, resulting in enhanced reactivity and selectivity in various important reaction transfor...

  10. A polysaccharide isolated from the liquid culture of Lentinus edodes (shiitake) mushroom mycelia containing black rice bran protects mice against Salmonellosis through up-regulation of the Th1 immune reaction

    Science.gov (United States)

    The present study investigated the antibacterial effect of a bioprocessed polysaccharide (BPP) isolated from Lentinus edodes liquid mycelial culture supplemented with black rice bran against murine salmonellosis. BPP was not bactericidal in vitro, but did, however stimulate uptake of the bacteria i...

  11. Ionization of liquids

    International Nuclear Information System (INIS)

    Gregg, E.C.; Bakale, G.

    1976-01-01

    Application of pulsed-conductivity techniques to ionization phenomena in liquids has yielded new results on electron transport and electron reactions in nonpolar liquids which we have extrapolated to biological systems to develop a novel model of direct radiation damage to mammalian cells that involves the unsolvated electron as the key reactant. Among these new results are electron attachment rate constants of thirty-five substituted nitrobenzene compounds measured in nonpolar solvents which when combined with product anion lifetimes are correlated with cellular radiosensitization efficiencies. From this study we found that electron attachment rates are dependent upon the electron mobility in the solvents and upon the dipole moment of the electron-accepting nitrobenzene compounds. The model also drawn upon energy-dependent electron attachment rates which we have measured in cryogenic liquids, and we have measured in the same solvents associative detachment rate constants and electron momentum transfer cross sections. In addition to these studies of electronic processes in liquids, we have measured ion mobilities of lecithin and chlorophyll in nonpolar solvents and conclude that these solutes form inverse micelles under certain conditions. Formation of these micelles permits electron transport through the lipid micellar walls and electron attachment to electron-accepting polar solutes inside the lipid vesicles to be studied

  12. Method for conducting exothermic reactions

    Science.gov (United States)

    Smith, L. Jr.; Hearn, D.; Jones, E.M. Jr.

    1993-01-05

    A liquid phase process for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F. wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  13. Optimal Liquidation under Stochastic Liquidity

    OpenAIRE

    Becherer, Dirk; Bilarev, Todor; Frentrup, Peter

    2016-01-01

    We solve explicitly a two-dimensional singular control problem of finite fuel type for infinite time horizon. The problem stems from the optimal liquidation of an asset position in a financial market with multiplicative and transient price impact. Liquidity is stochastic in that the volume effect process, which determines the inter-temporal resilience of the market in spirit of Predoiu, Shaikhet and Shreve (2011), is taken to be stochastic, being driven by own random noise. The optimal contro...

  14. Silicon-based sleeve devices for chemical reactions

    Science.gov (United States)

    Northrup, M. Allen; Mariella, Jr., Raymond P.; Carrano, Anthony V.; Balch, Joseph W.

    1996-01-01

    A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

  15. Taylor flow hydrodynamics in gas-liquid-solid micro reactors

    NARCIS (Netherlands)

    Warnier, M.J.F.

    2009-01-01

    Chemical reactions in which a gas phase component reacts with a liquid phase omponent at the surface of a solid catalyst are often encountered in chemical industry. The rate of such a gas-liquid-solid reaction is often limited by the mass transfer rate of the gas phase component, which depends on

  16. Gas-liquid reactor / separator: dynamics and operability characteristics

    NARCIS (Netherlands)

    Ranade, V.; Kuipers, J.A.M.; Versteeg, Geert

    1999-01-01

    A comprehensive mathematical model is developed to simulate gas¿liquid reactor in which both, reactants as well as products enter or leave the reactor in gas phase while the reactions take place in liquid phase. A case of first-order reaction (isothermal) was investigated in detail using the dynamic

  17. Liquidity risk and contagion for liquid funds

    OpenAIRE

    Darolles , Serge; Dudek , Jeremy; Le Fol , Gaëlle

    2014-01-01

    Fund managers face liquidity problems but they have to distinguish the market liquidity risk implied by their assets and the funding liquidity risk. This latter is due to both the liquidity mismatch between assets and liabilities and the redemption risk due to the possible outflows from clients. The main contribution of this paper is the analysis of contagion looking at common market liquidity problems to detect funding liquidity problems. Using the CDS Bond Spread basis as a liquidity indica...

  18. Radiation Chemistry and Photochemistry of Ionic Liquids

    International Nuclear Information System (INIS)

    Wishart, J.F.; Takahaski, K.

    2010-01-01

    As our understanding of ionic liquids and their tunable properties has grown, it is possible to see many opportunities for ionic liquids to contribute to the sustainable use of energy. The potential safety and environmental benefits of ionic liquids, as compared to conventional solvents, have attracted interest in their use as processing media for the nuclear fuel cycle. Therefore, an understanding of the interactions of ionizing radiation and photons with ionic liquids is strongly needed. However, the radiation chemistry of ionic liquids is still a relatively unexplored topic although there has been a significant increase in the number of researchers in the field recently. This article provides a brief introduction to ionic liquids and their interesting properties, and recent advances in the radiation chemistry and photochemistry of ionic liquids. In this article, we will mainly focus on excess electron dynamics and radical reaction dynamics. Because solvation dynamics processes in ionic liquids are much slower than in molecular solvents, one of the distinguishing characteristics is that pre-solvated electrons play an important role in ionic liquid radiolysis. It will be also shown that the reaction dynamics of radical ions is significantly different from that observed in molecular solvents because of the Coulombic screening effects and electrostatic interactions in ionic liquids.

  19. Hidden Liquidity

    OpenAIRE

    Cebiroglu, Gökhan; Horst, Ulrich

    2012-01-01

    We cross-sectionally analyze the presence of aggregated hidden depth and trade volume in the S&P 500 and identify its key determinants. We find that the spread is the main predictor for a stock’s hidden dimension, both in terms of traded and posted liquidity. Our findings moreover suggest that large hidden orders are associated with larger transaction costs, higher price impact and increased volatility. In particular, as large hidden orders fail to attract (latent) liquidity to the market, hi...

  20. Quasielastic reactions

    International Nuclear Information System (INIS)

    Hansen, O.

    1983-01-01

    A brief review is presented of the experimental and theoretical situation regarding transfer reactions and inelastic scattering. In the first category there is little (very little) precision data for heavy projectiles and consequently almost no experience with quantitative theoretical analysis. For the inelastic scattering the rather extensive data strongly supports the coupled channels models with collective formfactors. At the most back angles, at intensities about 10 -5 of Rutherford scattering, a second, compound-like mechanism becomes dominant. The description of the interplay of these two opposite mechanisms provides a new challenge for our understanding

  1. Use of ionic liquids as coordination ligands for organometallic catalysts

    Science.gov (United States)

    Li, Zaiwei [Moreno Valley, CA; Tang, Yongchun [Walnut, CA; Cheng,; Jihong, [Arcadia, CA

    2009-11-10

    Aspects of the present invention relate to compositions and methods for the use of ionic liquids with dissolved metal compounds as catalysts for a variety of chemical reactions. Ionic liquids are salts that generally are liquids at room temperature, and are capable of dissolving a many types of compounds that are relatively insoluble in aqueous or organic solvent systems. Specifically, ionic liquids may dissolve metal compounds to produce homogeneous and heterogeneous organometallic catalysts. One industrially-important chemical reaction that may be catalyzed by metal-containing ionic liquid catalysts is the conversion of methane to methanol.

  2. Spontaneous Marangoni Mixing of Miscible Liquids at a Liquid-Liquid-Air Contact Line.

    Science.gov (United States)

    Kim, Hyoungsoo; Lee, Jeongsu; Kim, Tae-Hong; Kim, Ho-Young

    2015-08-11

    We investigate the flow patterns created when a liquid drop contacts a reservoir liquid, which has implications on various physicochemical and biochemical reactions including mixing in microfluidic systems. The localized vortical flow spontaneously triggered by the difference of surface tension between the two liquids is studied, which is thus termed the Marangoni vortex. To quantitatively investigate the strength of vortices, we performed particle image velocimetry (PIV) experiments by varying the surface tension difference, the gap of the flow cell, the density and viscosity of the reservoir liquid, and the size of the drop. A scaling law that balances the interfacial energy of the system with the kinetic energy of the vortical flows allows us to understand the functional dependence of the Marangoni vortex strength on various experimental parameters.

  3. Nuclear reactions

    International Nuclear Information System (INIS)

    Corner, J.; Richardson, K.; Fenton, N.

    1990-01-01

    Nuclear reactions' marks a new development in the study of television as an agency of public policy debate. During the Eighties, nuclear energy became a major international issue. The disasters at Three-mile Island and Chernobyl created a global anxiety about its risks and a new sensitivity to it among politicians and journalists. This book is a case-study into documentary depictions of nuclear energy in television and video programmes and into the interpretations and responses of viewers drawn from many different occupational groupings. How are the complex and specialist arguments about benefit, risk and proof conveyed through the different conventions of commentary, interview and film sequence? What symbolic associations does the visual language of television bring to portrayals of the issue? And how do viewers make sense of various and conflicting accounts, connecting what they see and hear on the screen with their pre-existing knowledge, experience and 'civic' expectations. The authors examine some of the contrasting forms and themes which have been used by programme makers to explain and persuade, and then give a sustained analysis of the nature and sources of viewers' own accounts. 'Nuclear Reactions' inquires into the public meanings surrounding energy and the environment, spelling out in its conclusion some of the implications for future media treatments of this issue. It is also a key contribution to the international literature on 'television knowledge' and the processes of active viewing. (author)

  4. Liquid ventilation.

    Science.gov (United States)

    Sarkar, Suman; Paswan, Anil; Prakas, S

    2014-01-01

    Human have lungs to breathe air and they have no gills to breath liquids like fish. When the surface tension at the air-liquid interface of the lung increases as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV) is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen as the inert carrier of oxygen and carbon dioxide offers a number of advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. It is well-known that respiratory diseases are one of the most common causes of morbidity and mortality in intensive care unit. During the past few years several new modalities of treatment have been introduced. One of them and probably the most fascinating, is of LV. Partial LV, on which much of the existing research has concentrated, requires partial filling of lungs with perfluorocarbons (PFC's) and ventilation with gas tidal volumes using conventional mechanical ventilators. Various physico-chemical properties of PFC's make them the ideal media. It results in a dramatic improvement in lung compliance and oxygenation and decline in mean airway pressure and oxygen requirements. No long-term side-effect reported.

  5. Liquid Marbles

    KAUST Repository

    Khalil, Kareem

    2012-12-01

    Granulation, the process of formation of granules from a combination of base powders and binder liquids, has been a subject of research for almost 50 years, studied extensively for its vast applications, primarily to the pharmaceutical industry sector. The principal aim of granulation is to form granules comprised of the active pharmaceutical ingredients (API’s), which have more desirable handling and flowability properties than raw powders. It is also essential to ensure an even distribution of active ingredients within a tablet with the goal of achieving time‐controlled release of drugs. Due to the product‐specific nature of the industry, however, data is largely empirical [1]. For example, the raw powders used can vary in size by two orders of magnitude with narrow or broad size distributions. The physical properties of the binder liquids can also vary significantly depending on the powder properties and required granule size. Some significant progress has been made to better our understanding of the overall granulation process [1] and it is widely accepted that the initial nucleation / wetting stage, when the binder liquid first wets the powders, is key to the whole process. As such, many experimental studies have been conducted in attempt to elucidate the physics of this first stage [1], with two main mechanisms being observed – classified by Ivenson [1] as the “Traditional description” and the “Modern Approach”. See Figure 1 for a graphical definition of these two mechanisms. Recent studies have focused on the latter approach [1] and a new, exciting development in this field is the Liquid Marble. This interesting formation occurs when a liquid droplet interacts with a hydrophobic (or superhydrophobic) powder. The droplet can become encased in the powder, which essentially provides a protective “shell” or “jacket” for the liquid inside [2]. The liquid inside is then isolated from contact with other solids or liquids and has some

  6. Radioactive liquid wastes processing device

    International Nuclear Information System (INIS)

    Sauda, Kenzo; Koshiba, Yukihiko; Yagi, Takuro; Yamazaki, Hideki.

    1985-01-01

    Purpose: To carry out optimum photooxidizing procession following after the fluctuation in the density of organic materials in radioactive liquid wastes to thereby realize automatic remote procession. Constitution: A reaction tank is equipped with an ultraviolet lamp and an ozone dispersing means for the oxidizing treatment of organic materials in liquid wastes under the irradiation of UV rays. There are also provided organic material density measuring devices to the inlet and outlet of the reaction tank, and a control device for controlling the UV lamp power adjusting depending on the measured density. The output of the UV lamp is most conveniently adjusted by changing the applied voltage. The liquid wastes in which the radioactivity dose is reduced to a predetermined level are returned to the reaction tank by the operation of a switching valve for reprocession. The amount of the liquid wastes at the inlet is controlled depending on the measured ozone density by the adjusting valve. In this way, the amount of organic materials to be subjected to photolysis can be kept within a certain limit. (Kamimura, M.)

  7. Liquid metal corrosion considerations in alloy development

    International Nuclear Information System (INIS)

    Tortorelli, P.F.; DeVan, J.H.

    1984-01-01

    Liquid metal corrosion can be an important consideration in developing alloys for fusion and fast breeder reactors and other applications. Because of the many different forms of liquid metal corrosion (dissolution, alloying, carbon transfer, etc.), alloy optimization based on corrosion resistance depends on a number of factors such as the application temperatures, the particular liquid metal, and the level and nature of impurities in the liquid and solid metals. The present paper reviews the various forms of corrosion by lithium, lead, and sodium and indicates how such corrosion reactions can influence the alloy development process

  8. Gas-liquid contacting in mixing vessels

    International Nuclear Information System (INIS)

    Mann, R.

    1983-01-01

    This report by Dr. R. Mann of UMIST presents a critical survey of literature on the contacting of gases with liquids in stirred vessels. Research undertaken in the last fifteen years in analysed, and promising areas for future research are identified. The report deals with physical contacting, mass transfer between the gas and liquid phases and the utilisation of the stirred vessel as a gas-liquid reactor. Three sections are given on gas-liquid contacting: physical aspects; interphase mass transfer; and chemical reactions. It also discusses recent new approaches and includes a summary of conclusions, nomenclature and references

  9. Microfabricated sleeve devices for chemical reactions

    Science.gov (United States)

    Northrup, M. Allen

    2003-01-01

    A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and non-silicon based materials to provide the thermal properties desired. For example, the chamber may combine a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

  10. Preparation of Ag@mSiO{sub 2} and Pt@mSiO{sub 2}nano composites using trioctylmethyl ammonium hydrogen phthalate (TOMAHP) ionic liquid as reaction medium

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Sujoy, E-mail: sujoyb@barc.gov.in [Chemical Engineering Group, Bhabha Atomic Research Centre, Mumbai 400085 (India); Dasgupta, Kinshuk [Materials Group, Bhabha Atomic Research Centre, Mumbai 400085 (India); Bahadur, Jitendra [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tewari, Raghavendra [Materials Group, Bhabha Atomic Research Centre, Mumbai 400085 (India); Mazumder, Subhasish [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2016-09-15

    A novel one step green chemistry approach utilizing trioctylmethyl ammonium hydrogen phthalate (TOMAHP), task specific ionic liquid has been attempted for synthesis of Ag and Pt nanoparticles supported on silica (Ag@mSiO{sub 2} and Pt@mSiO{sub 2}). Structure, size distribution and morphology of these nano-composite particles were evaluated using X-ray diffraction (XRD), transmission electron microscopy (TEM), small angle neutron scattering (SANS) as well as small angle X-ray scattering (SAXS) techniques. The XRD results show that Ag/Pt metal nanoparticles deposited on to SiO{sub 2} surface are face center cubic (fcc) in nature. The TEM and SAXS/SANS results show the morphology and size distributions of Ag and Pt nanoparticles loaded on to the surface of SiO{sub 2}. It has been found that Ag nanoparticles are well dispersed on to the SiO{sub 2} surface and are quite monodisperse in size, whereas Pt nanoparticles are quite polydisperse in size and forms aggregate or chain like structure on SiO{sub 2} surface containing primary nanoparticles of typical size range 3–7 nm. The stability of nanoparticles, which controls its dispersion on SiO{sub 2} substrate, has been discussed. - Graphical abstract: Mechanism for Ag@mSiO{sub 2} and Pt@mSiO{sub 2} nano composites in TOMAHP ionic liquid medium. - Highlights: • Novel methods for preparation of Pt@SiO{sub 2} and Ag@SiO{sub 2} nano composite in functionalized ionic liquid. • Pt@SiO{sub 2} and Ag@SiO{sub 2} nano composite are characterized using XRD, TEM as well as small angle x-ray scattering techniques. • The sizes of nano composite is <10 nm in size. • The method is simple one step, green chemical reduction method to prepare SiO{sub 2} support nano catalyst.

  11. Determination of the knight shift in liquid alloys of silver with lanthanides by stroboscopic observation of perturbed angular correlations according to the reaction 109Ag(p,n)109Cd

    International Nuclear Information System (INIS)

    Gundelfinger, F.

    1975-01-01

    In liquid alloys of the composition Agsub(1-x)Rsub(x) (0 109 Ag(p,n) 109 Cd* induced by 10 MeV protons. In first appoximation, the values found for the relative change of knight shift prove to be proportional to the negative z-component of the 4f-shell spin of the respective lanthanide metals. The major part of the knight shift is produced by the spin polarization of the conduction electrons due to coupling to the spins of the lanthanide ions. The possible coupling mechanisms are discussed. (orig./GSC) [de

  12. Spallation reactions; Reactions de spallation

    Energy Technology Data Exchange (ETDEWEB)

    Cugon, J.

    1996-12-31

    Spallation reactions dominate the interactions of hadrons with nuclei in the GeV range (from {approx} 0.1 to {approx} 10 GeV). They correspond to a sometimes important ejection of light particles leaving most of the time a residue of mass commensurate with the target mass. The main features of the experimental data are briefly reviewed. The most successful theoretical model, namely the intranuclear cascade + evaporation model, is presented. Its physical content, results and possible improvements are critically discussed. Alternative approaches are shortly reviewed. (author). 84 refs.

  13. An Improved Protocol for the Aldehyde Olefination Reaction Using (bmim ( as Reaction Medium

    Directory of Open Access Journals (Sweden)

    Vivek Srivastava

    2013-01-01

    Full Text Available [Ru(CODCl2]/CuCl2·2H2O/LiCl catalytic system works efficiently in ionic liquid media for aldehyde olefination reaction. It offers good yield and selectivity with the added advantage of 5 times recyclability for [Ru(CODCl2] /CuCl2·2H2O/LiCl catalytic system. We also successfully reduced the reaction time from 12 hours to 9 hours for the aldehyde olefination reaction.

  14. Ionic Liquids in Biomass Processing

    Science.gov (United States)

    Tan, Suzie Su Yin; Macfarlane, Douglas R.

    Ionic liquids have been studied for their special solvent properties in a wide range of processes, including reactions involving carbohydrates such as cellulose and glucose. Biomass is a widely available and renewable resource that is likely to become an economically viable source of starting materials for chemical and fuel production, especially with the price of petroleum set to increase as supplies are diminished. Biopolymers such as cellulose, hemicellulose and lignin may be converted to useful products, either by direct functionalisation of the polymers or depolymerisation to monomers, followed by microbial or chemical conversion to useful chemicals. Major barriers to the effective conversion of biomass currently include the high crystallinity of cellulose, high reactivity of carbohydrates and lignin, insolubility of cellulose in conventional solvents, as well as heterogeneity in the native lignocellulosic materials and in lignin itself. This combination of factors often results in highly heterogeneous depolymerisation products, which make efficient separation difficult. Thus the extraction, depolymerisation and conversion of biopolymers will require novel reaction systems in order to be both economically attractive and environmentally benign. The solubility of biopolymers in ionic liquids is a major advantage of their use, allowing homogeneous reaction conditions, and this has stimulated a growing research effort in this field. This review examines current research involving the use of ionic liquids in biomass reactions, with perspectives on how it relates to green chemistry, economic viability, and conventional biomass processes.

  15. Non-linear effects in the radiolysis-optically detected ESR of radical-ion pairs in liquid and glassy solutions. Reactions and motion of organic radicals as studied by ESR and OD ESR spectroscopy

    International Nuclear Information System (INIS)

    Antzutkin, O.

    1992-01-01

    This thesis is divided into two sections. The first part covers an introduction to the Optically Detected Electron Spin Resonance (OD ESR) spectroscopy and a short description of the OD ESR spectrometer built in Linkoeping University in 1991. In the second section the following topics are discussed: Non-linear effects in OD ESR spectroscopy and Reactions and motion of organic radicals trapped in freon matrices. (19 refs.)

  16. Modelling electroluminescence in liquid argon

    International Nuclear Information System (INIS)

    Stewart, D Y; Barker, G J; Bennieston, A J; Harrison, P F; McConkey, N; Morgan, B; Ramachers, Y A; Lightfoot, P K; Robinson, M; Spooner, N J C; Thompson, L

    2010-01-01

    We present Monte-Carlo simulations of electron transport through liquid argon motivated by our recent observation of electroluminescence light emanating from a thick gaseous electron multiplier (THGEM) in a liquid argon volume. All known elastic and inelastic reaction cross-sections have been accounted for, providing electroluminescence light yield predictions for arbitrary electrostatic fields. This study concludes that the large field gradients needed to produce electroluminescence cannot be accounted for by straightforward electrostatic field calculations based on ideal THGEM holes, suggesting that further experimental investigations are required.

  17. Tube in shell heat exchangers

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  18. Liquid helium

    CERN Document Server

    Atkins, K R

    1959-01-01

    Originally published in 1959 as part of the Cambridge Monographs on Physics series, this book addresses liquid helium from the dual perspectives of statistical mechanics and hydrodynamics. Atkins looks at both Helium Three and Helium Four, as well as the properties of a combination of the two isotopes. This book will be of value to anyone with an interest in the history of science and the study of one of the universe's most fundamental elements.

  19. kinetics of the coupled gas-iron reactions involving silicon and carbon

    African Journals Online (AJOL)

    user

    1985-09-01

    Sep 1, 1985 ... out for the system involving liquid iron containing carbon and silicon and a gas ... in content with liquid iron at. 15600C, the ... of carbon monoxide bubbles at the. Slag - metal ..... equilibrium strongly make chemical reactions.

  20. Polyneutron Chain Reactions

    International Nuclear Information System (INIS)

    John C. Fisher

    2000-01-01

    Although helium atoms do not form molecules, a sufficiently large number will bind into a stable liquid droplet. A comparable situation is expected for neutrons, with a sufficiently large number binding into a stable droplet of neutron matter. Such polyneutron droplets can be viewed as isotopes of an element with nuclear charge Z=0, tentatively denoted neutrium, symbol Nt. Because of the relatively weak binding of neutrons compared with that of a mix of neutrons and protons, the minimum number of neutrons required for stability of a droplet is fairly large. Early estimates of ∼60 may be reduced to a dozen or so by the BCS pairing interaction. The Nt entries with N≥12 are new to the table of isotopes. Because all of them are beta-unstable, none is expected to persist as a free particle. Yet, some may occasionally be produced by means to be described below, and it is of interest to examine their decay chains and their interactions with charged nuclei to ascertain how their presence might be revealed. Although these reactions are interesting, they cannot be taken seriously without identifying a source for the initial Nt isotope that begins the chain. Here, we consider possible interactions between 16 O and A Nt. Although there is no strong interaction between them, we can expect a very weak residual attraction that can form a loosely bound 16 O A Nt nuclear molecule. This is not a compound nucleus in the usual sense because, considered as fluids, the 16 O and A Nt droplets are immiscible. For a droplet with fewer than about 60 neutrons, beta decay of A Nt is prevented by the buildup of Coulomb energy associated with transforming A Nt into A H in close proximity to 16 O. Thus, it is possible that 16 O A Nt molecules can persist indefinitely and that a few of them may be present in ordinary water as supermassive oxygen nuclei. Because the binding of these molecules is weak, the A Nt component can tunnel to an adjacent nucleus, and if the adjacent nucleus is 18 O, a

  1. A study on sodium-concrete reaction

    Energy Technology Data Exchange (ETDEWEB)

    Pae, Jae Huem; Min, Byung Hoon; Lee, Joon Sik; Lee, Choong Hui; Chung, Ki Hong; Keum, Choong Ki [Suwon University, Suwon (Korea, Republic of)

    1994-07-15

    Sodium is commonly used as a coolant in liquid metal reactor. A large amount of its leakage may be possible in hypothetical accidents, even though the possibility is very low. In case that the leaked hot sodium comes in direct contact with structural concrete of liquid metal reactor, the reactor`s integrity can be challenged by the rupture of structure materials, hydrogen generation and its explosion, and release of radioactive aerosols due to sodium-concrete reaction. The knowledge of sodium-concrete reaction is evaluated to be one of the important and indispensable technologies for the establishment of safety measure in liquid metal reactor. In this study, the experimental facility of sodium-concrete reaction is to be designed, constructed and operated. And the reaction phenomena of sodium-concrete reaction is also to be analyzed through the experimental results. The aim of this study is to establish the measure of safety and protection for sodium-related facilities and to secure one of the fundamental technologies of liquid metal reactor safety. 47 refs., 7 figs., 13 tab.

  2. Structure and reactivity of C7H7+ ions from the decay of tritiated toluenes. Part 1. Reactions of free tolyl ions with methanol in the gas and liquid phases

    International Nuclear Information System (INIS)

    Cacace, F.; Ciranni, G.; Sparapani, C.; Speranza, M.

    1984-01-01

    Labeled tolyl cations from the decay of ring-multitritiated toluene have been allowed to react with methanol in the liquid and the gas phases, at pressures ranging from 6 to 100 torr, yielding methyl tolyl ethers as the major products, without appreciable formation of benzyl methyl ether. The isomeric composition of the products from the gaseous systems depends on the pressure, the percentage of o-tolyl ether increasing at the expense of the para isomer as the methanol pressure is reduced. The results show that the three tolyl ions exist as distinct species in the dilute gas state. When formed in a sufficiently excited state, as from the β decay of a 3 H atom in toluene, they undergo appreciable interconversion, without detectable isomerization to the benzyl cation, at least within the pressure range accessible to the decay technique. 50 references, 1 table

  3. Chain reaction

    International Nuclear Information System (INIS)

    Balogh, Brian.

    1991-01-01

    Chain Reaction is a work of recent American political history. It seeks to explain how and why America came to depend so heavily on its experts after World War II, how those experts translated that authority into political clout, and why that authority and political discretion declined in the 1970s. The author's research into the internal memoranda of the Atomic Energy Commission substantiates his argument in historical detail. It was not the ravages of American anti-intellectualism, as so many scholars have argued, that brought the experts back down to earth. Rather, their decline can be traced to the very roots of their success after World War II. The need to over-state anticipated results in order to garner public support, incessant professional and bureaucratic specialization, and the sheer proliferation of expertise pushed arcane and insulated debates between experts into public forums at the same time that a broad cross section of political participants found it easier to gain access to their own expertise. These tendencies ultimately undermined the political influence of all experts. (author)

  4. Reaction rate of hydrolysis of iodine

    International Nuclear Information System (INIS)

    Miyake, Yoshikazu; Eguchi, Wataru; Adachi, Motonari

    1979-01-01

    Absorption rates of dilute iodine vapor contained in air by aqueous mixtures of sodium hydroxide and boric acid were measured using a laminar liquid jet column absorber at 298 K. Absorption rates in this system are controlled by a series of complex reactions taking place in the liquid phase. The reaction rate constant of iodine hydrolysis in the aqueous phase was determined from the absorption rates observed under the conditions that the base-catalytic hydrolysis reaction of iodine can be considered to be irreversible and that other reactions can be neglected. The absorption rates calculated theoretically with the rate constant value obtained above were in good accordance with the whole experimental data observed for a wide range of experimental conditions. (author)

  5. The behaviour of concrete under attack of liquid steel

    International Nuclear Information System (INIS)

    Schneider, U.; Ehm, C.; Diederichs, U.

    1983-01-01

    Investigations were carried out to study the interaction between concrete and liquid steel. Different types and different forms of concrete were investigated at temperatures of liquid steel between 1.600 and 2.600 0 C. The liquid steel of 1.600 0 C was produced in an induction furnace, the liquid steel of 2.600 0 C was produced in concrete crucibles by metallothermic reactions. The reactions occuring during the interaction of concrete and liquid steel may be summarized as follows: - Concrete reacts violently upon sudden loading with high temperatures and high heat fluxes. Great quantities of steam and gases are generated. The mechanical strength decreases rapidly with increasing temperature. -At about 1.200 0 C concrete begins to melt. First the cement matrix melts, than the aggregates melt. The melts of different concretes consist of different constituents and their reactions with liquid steel vary. The temperature of the liquid steel significantly influences the intensity of the reactions and the erosion rates. - The erosion rates amounted to 30 mm/min, when liquid steel was produced in concrete crucibles. When cylindrical concrete specimens were immersed in molten steel the rate of melting off amounted up to 66 mm/min. - The dissipation of heat during the interaction brings about that the reactions between concrete and liquid steel vanish gradually, if no additional energy is fed into the system. (orig.)

  6. Liquid electrode

    Science.gov (United States)

    Ekechukwu, A.A.

    1994-07-05

    A dropping electrolyte electrode is described for use in electrochemical analysis of non-polar sample solutions, such as benzene or cyclohexane. The liquid electrode, preferably an aqueous salt solution immiscible in the sample solution, is introduced into the solution in dropwise fashion from a capillary. The electrolyte is introduced at a known rate, thus, the droplets each have the same volume and surface area. The electrode is used in making standard electrochemical measurements in order to determine properties of non-polar sample solutions. 2 figures.

  7. Liquid diode

    International Nuclear Information System (INIS)

    1976-01-01

    The liquid diode is designed for a flowmeter chamber which has an inlet and an outlet duct, and a flow chamber with a cross-section which is greater than inlet. In the space between the inlet and outlet are two screens with a number of spheres, which may be of different sizes and weights. The screen on the inlet side is smaller than that at the outlet, so that the spheres are able to block the inlet under reverse flow conditions, but do not block the outlet. The system functions as a non-return valve. (G.C.)

  8. Leak detector of liquid sodium

    International Nuclear Information System (INIS)

    Himeno, Yoshiaki.

    1975-01-01

    Object: To arrange a cable core connected to a leakage current detector on the outer wall of piping for liquid sodium, devices or the like and apply a voltage to said core and outer wall to quickly and securely detect the leakage of liquid sodium. Structure: A cable, which is composed of metal coating formed of metal material (copper, steel, stainless, etc.) which is apt to be corroded by reaction products of liquid sodium with water and oxygen in air, and metal oxide (such as magnesium oxide, beryllium oxide, aluminum oxide) as an electric insulator is arranged on the outer wall of pipes or devices. In the event sodium is leaked from the pipes or devices, said metal coating and the insulator are corroded, and the leakage of sodium is sensed by a leakage current detector through the core in the cable. (Kamimura, M.)

  9. Speciation of arsenic in water samples by high-performance liquid chromatography-hydride generation-atomic absorption spectrometry at trace levels using a post-column reaction system

    Energy Technology Data Exchange (ETDEWEB)

    Stummeyer, J. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Harazim, B. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Wippermann, T. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany)

    1996-02-01

    Anion-exchange HPLC has been combined with hydride generation - atomic absorption spectrometry (HG-AAS) for the routine speciation of arsenite, arsenate, monomethylarsenic acid and dimethylarsinic acid. The sensitivity of the AAS-detection was increased by a post-column reaction system to achieve complete formation of volatile arsines from the methylated species and arsenate. The system allows the quantitative determination of 0.5 {mu}g/l of each arsenic compound in water samples. The stability of synthetical and natural water containing arsenic at trace levels was investigated. To preserve stored water samples, a method for quantitative separation of arsenate at high pH-values with the basic anion-exchange resin Dowex 1 x 8 was developed. (orig.)

  10. From Funding Liquidity to Market Liquidity

    DEFF Research Database (Denmark)

    Dick-Nielsen, Jens; Lund, Jesper; Gyntelberg, Jacob

    This paper shows empirically that funding liquidity drives market liquidity. As it becomes harder to secure term funding in the money markets, liquidity deteriorates in the Danish bond market. We show that the first principal component of bond market liquidity is driven by the market makers...... for other European government bonds using MTS data. The findings suggest that regulatory bond based liquidity buffers for banks will have limited effectiveness....

  11. Determination of eugenol in rat plasma by liquid chromatography-quadrupole ion trap mass spectrometry using a simple off-line dansyl chloride derivatization reaction to enhance signal intensity.

    Science.gov (United States)

    Beaudry, Francis; Guénette, Sarah Annie; Vachon, Pascal

    2006-11-01

    A rapid, selective and sensitive method was developed for the determination of eugenol concentration using an off-line dansyl chloride derivatization step to enhance signal intensity. The method consisted of a protein precipitation extraction followed by derivatization with dansyl chloride and analysis by full scan liquid chromatography electrospray quadrupole ion trap mass spectrometry (LC-ESI-QIT). The separation was achieved using a 100 x 2 mm C(8) analytical column combined with an isocratic mobile phase composed of 75:25 acetonitrile: 0.1% formic acid in water set at a flow rate of 0.25 mL/min. Signal intensity of the eugenol-dansyl chloride derivative was increased up to 100-fold as compared with the underivatized eugenol in positive electrospray mode. An analytical range of 100-20,000 ng/mL was used in the calibration curve of plasma and blood samples. The LOD observed was 0.5 pg injected on column. The novel method met all requirements of specificity, sensitivity, linearity, precision, accuracy and stability. In conclusion, a rapid and sensitive LC-ESI/MS/MS method using a derivatization agent was developed to enhance signal intensity of eugenol. Copyright (c) 2006 John Wiley & Sons, Ltd.

  12. Reaction of β-blockers and β-agonist pharmaceuticals with aqueous chlorine. Investigation of kinetics and by-products by liquid chromatography quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Quintana, José Benito; Rodil, Rosario; Cela, Rafael

    2012-06-01

    The degradation of two β-blockers (atenolol and propranolol) and one β-receptor agonist (salbutamol) during water chlorination was investigated by liquid chromatography-mass spectrometry (LC-MS). An accurate-mass quadrupole time-of-flight system (QTOF) was used to follow the time course of the pharmaceuticals and also used in the identification of the by-products. The degradation kinetics of these drugs was investigated at different concentrations of chlorine, bromide and sample pH by means of a Box-Behnken experimental design. Depending on these factors, dissipation half-lives varied in the ranges 68-145 h for atenolol, 1.3-33 min for salbutamol and 42-8362 min for propranolol. Normally, an increase in chlorine dosage and pH resulted in faster degradation of these pharmaceuticals. Moreover, the presence of bromide in water samples also resulted in a faster transformation of atenolol at low chlorine doses. The use of an accurate-mass high-resolution LC-QTOF-MS system permitted the identification of a total of 14 by-products. The transformation pathway of β-blockers/agonists consisted mainly of halogenations, hydroxylations and dealkylations. Also, many of these by-products are stable, depending on the chlorination operational parameters employed.

  13. Experimental Investigation of Gaseous Reaction Products from Na-CO{sub 2} Reaction in Na/CO{sub 2} Heat Exchanger leakage scenario

    Energy Technology Data Exchange (ETDEWEB)

    Go, A-Reum; Jung, Hwa-Young; Kim, Min Seok; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of); Min, Jaehong; Wi, Myung-Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The SFRs have operated with the steam Rankine cycle as a power conversion system. However, the potential sodium-water reaction (SWR) whose chemical reactivity is vigorous and instantaneous has been one of the major issues concerning the safety and integrity of the SFRs. In order to avoid SWR, supercritical CO{sub 2}(S-CO{sub 2}) Brayton cycles have been investigated recently. Compared to conventional steam Rankine cycles, S-CO{sub 2} Brayton cycle features higher thermal efficiency and potential compactness of its required equipment. In spite of the superiority of S-CO{sub 2} Brayton cycle, there is a potential reactive process between sodium and CO{sub 2} if the pressure boundary fails in the sodium-CO{sub 2} heat exchanger. The leakage scenario which could lead to mechanical and thermal problems should be evaluated. Previous studies have reported the following major reaction formulas. Each reaction occurs competitively. In this paper, the experimental setup to observe the pressure variation and CO concentration in Na-CO{sub 2} heat exchanger during the CO{sub 2} leak is explained. Before the experiment is carried out, water-CO{sub 2} mock-up test will be performed. In order to evaluate the leakage scenario in Na-CO{sub 2} heat exchanger more accurately, this study will be important for guaranteeing the system of SFR coupled with S-CO{sub 2} cycle.

  14. Thioimidazolium Ionic Liquids as Tunable Alkylating Agents.

    Science.gov (United States)

    Guterman, Ryan; Miao, Han; Antonietti, Markus

    2018-01-19

    Alkylating ionic liquids based on the thioimidazolium structure combine the conventional properties of ionic liquids, including low melting point and nonvolatility, with the alkylating function. Alkyl transfer occurs exclusively from the S-alkyl position, thus allowing for easy derivatization of the structure without compromising specificity. We apply this feature to tune the electrophilicty of the cation to profoundly affect the reactivity of these alkylating ionic liquids, with a caffeine-derived compound possessing the highest reactivity. Anion choice was found to affect reaction rates, with iodide anions assisting in the alkylation reaction through a "shuttling" process. The ability to tune the properties of the alkylating agent using the toolbox of ionic liquid chemistry highlights the modular nature of these compounds as a platform for alkylating agent design and integration in to future systems.

  15. Excited state intramolecular charge transfer reaction in 4-(1 ...

    Indian Academy of Sciences (India)

    Administrator

    cal reactions to the determination of paleotempera- tures from isotopic ... ordered liquid than H2O due to stronger H-bond in- teractions in the deuterated water ... layer chromatography and monitoring the excitation wavelength dependence of ...

  16. Study of thioglycosylation in ionic liquids

    Directory of Open Access Journals (Sweden)

    Ragauskas Arthur

    2006-06-01

    Full Text Available Abstract A novel, green chemistry, glycosylation strategy was developed based upon the use of ionic liquids. Research studies demonstrated that thiomethyl glycosides could readily be activated with methyl trifluoromethane sulfonate, using 1-butyl-3-methylimidazolium tetrafluoroborate as a solvent. This green chemistry glycosylation strategy provided disaccharides with typical yields averaging 75%. The ionic liquid solvent could be readily reused for five sequential glycosylation reactions with no impact on product yield.

  17. Chemical kinetics and reaction mechanism

    International Nuclear Information System (INIS)

    Jung, Ou Sik; Park, Youn Yeol

    1996-12-01

    This book is about chemical kinetics and reaction mechanism. It consists of eleven chapters, which deal with reaction and reaction speed on reaction mechanism, simple reaction by rate expression, reversible reaction and simultaneous reaction, successive reaction, complicated reaction mechanism, assumption for reaction mechanism, transition state theory, successive reaction and oscillating reaction, reaction by solution, research method high except kinetics on reaction mechanism, high reaction of kinetics like pulsed radiolysis.

  18. A Polysaccharide isolated from the liquid culture of Lentinus edodes (Shiitake) mushroom mycelia containing black rice bran protects mice against salmonellosis through upregulation of the Th1 immune reaction.

    Science.gov (United States)

    Kim, Sung Phil; Park, Sun Ok; Lee, Sang Jong; Nam, Seok Hyun; Friedman, Mendel

    2014-03-19

    The present study investigated the antibacterial effect of a bioprocessed polysaccharide (BPP) isolated from Lentinus edodes liquid mycelial culture supplemented with black rice bran against murine salmonellosis. BPP was not bactericidal in vitro, it did, however, stimulate uptake of the bacteria into RAW 264.7 murine macrophage cells, as indicated by increased colony-forming unit (CFU) counts of the contents of the lysed macrophages incubated with Salmonella Typhimurium for 30 and 60 min. Two hours postinfection, the bacterial counts drastically increased in the macrophages, but 4 and 8 h postinfection BPP extract-treated cells showed lower bacterial counts than the vehicle (saline phosphate pH 7.4 buffer, PBS)-treated control. BPP elicited altered morphology and markedly elevated inducible nitric oxide (NO) synthase (iNOS) mRNA and protein expression in the infected macrophage cells. BPP also activated leukocytes in S. Typhimurium-infected mice, as determined by spleen lymphocyte proliferation and IFN-γ levels in mice sera. ELISA analysis on cytokine production by Th1 and Th2 immune cells from splenocytes of infected mice showed significant increases in the levels of the following Th1 cytokines: IL-1β, IL-2, IL-6, and IL-12. Histology assays of the livers of mice infected with a sublethal dose (1 × 10(4) CFU) of S. Typhimurium showed that BPP, administered daily through an intraperitoneal (ip) or oral route, protected against necrosis of the liver, a biomarker of in vivo salmonellosis. The lifespan of mice similarly infected with a lethal dose of S. Typhimurium (1 × 10(5) CFU) was significantly extended by ip injection or oral administration of the BPP without side effects. These results suggest that the activity of BPP against bacterial infection in mice occurs mainly through the activation of macrophage-mediated immune response resulting from augmented Th1 immunity. The significance of the results for microbial food safety and human health and further

  19. Preparation of a poly(3'-azido-3'-deoxythymidine-co-propargyl methacrylate-co-pentaerythritol triacrylate) monolithic column by in situ polymerization and a click reaction for capillary liquid chromatography of small molecules and proteins.

    Science.gov (United States)

    Lin, Zian; Yu, Ruifang; Hu, Wenli; Zheng, Jiangnan; Tong, Ping; Zhao, Hongzhi; Cai, Zongwei

    2015-07-07

    Combining free radical polymerization with click chemistry via a copper-mediated azide/alkyne cycloaddition (CuAAC) reaction in a "one-pot" process, a facile approach was developed for the preparation of a poly(3'-azido-3'-deoxythymidine-co-propargyl methacrylate-co-pentaerythritol triacrylate) (AZT-co-PMA-co-PETA) monolithic column. The resulting poly(AZT-co-PMA-co-PETA) monolith showed a relatively homogeneous monolithic structure, good permeability and mechanical stability. Different ratios of monomers and porogens were used for optimizing the properties of a monolithic column. A series of alkylbenzenes, amides, anilines, and benzoic acids were used to evaluate the chromatographic properties of the polymer monolith in terms of hydrophobic, hydrophilic and cation-exchange interactions, and the results showed that the poly(AZT-co-PMA-co-PETA) monolith exhibited more flexible adjustment in chromatographic selectivity than that of the parent poly(PMA-co-PETA) and AZT-modified poly(PMA-co-PETA) monoliths. Column efficiencies for toluene, DMF, and formamide with 35,000-48,000 theoretical plates per m could be obtained at a linear velocity of 0.17 mm s(-1). The run-to-run, column-to-column, and batch-to-batch repeatabilities of the retention factors were less than 4.2%. In addition, the proposed monolith was also applied to efficient separation of sulfonamides, nucleobases and nucleosides, anesthetics and proteins for demonstrating its potential.

  20. Picosecond radiolysis of ionic liquids

    International Nuclear Information System (INIS)

    Funston, A.M.; Wishart, J.F.; Neta, P.; Lall, S.I.; Engel, R.

    2003-01-01

    Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in nuclear fuel and waste processing, energy production, improving the efficiency and safety of industrial chemical processes, and pollution prevention. Ionic liquids are completely nonvolatile, noncombustible, highly conductive, recyclable and capable of dissolving a wide variety of materials. An understanding of the radiation chemistry of ionic liquids is important for development of their applications in radioactive material processing and for the application of pulse radiolysis techniques to the general study of chemical reactivity in ionic liquids. Kinetic studies with a picosecond electron accelerator, such as the BNL Laser-Electron Accelerator Facility (LEAF), allow one to observe primary radiation products and their reactions on short time scales. For example, the solvated electron lifetime in neat methyltributylammonium bis(trifluoromethylsulfonyl)imide is ∼300 ns and its absorption maximum is ∼1400 nm. Kinetic studies of primary radiolytic products and their reactivities will be described for several types of ionic liquids. Supported in part by the U.S. Department of Energy, Division of Chemical Sciences, Office of Basic Energy Sciences, under contract DE-AC02-98-CH1088

  1. Investigation of heterogeneous reactions of NO2 on aqueous surfaces

    International Nuclear Information System (INIS)

    Mertes, S.

    1992-01-01

    A microjet apparatus was developed for the purpose of measuring the loss in the gaseous phase and the uptake in the liquid phase of nitrogen on the basis of heterogeneous processes on a liquid surface. The measurements were to provide information on the mass accomodation coefficient α and on assumed surface reactions of NO 2 . (orig./BBR) [de

  2. Cumulates, Dykes and Pressure Solution in the Ice-Salt Mantle of Europa: Geological Consequences of Pressure Dependent Liquid Compositions and Volume Changes During Ice-Salt Melting Reactions.

    Science.gov (United States)

    Day, S.; Asphaug, E.; Bruesch, L.

    2002-12-01

    Water-salt analogue experiments used to investigate cumulate processes in silicate magmas, along with observations of sea ice and ice shelf behaviour, indicate that crystal-melt separation in water-salt systems is a rapid and efficient process even on scales of millimetres and minutes. Squeezing-out of residual melts by matrix compaction is also predicted to be rapid on geological timescales. We predict that the ice-salt mantle of Europa is likely to be strongly stratified, with a layered structure predictable from density and phase relationships between ice polymorphs, aqueous saline solutions and crystalline salts such as hydrated magnesium sulphates (determined experimentally by, inter alia, Hogenboom et al). A surface layer of water ice flotation cumulate will be separated from denser salt cumulates by a cotectic horizon. This cotectic horizon will be both the site of subsequent lowest-temperature melting and a level of neutral buoyancy for the saline melts produced. Initial melting will be in a narrow depth range owing to increasing melting temperature with decreasing pressure: the phase relations argue against direct melt-though to the surface unless vesiculation occurs. Overpressuring of dense melts due to volume expansion on cotectic melting is predicted to lead to lateral dyke emplacement and extension above the dyke tips. Once the liquid leaves the cotectic, melting of water ice will involve negative volume change. Impact-generated melts will drain downwards through the fractured zones beneath crater floors. A feature in the complex crater Mannan'an, with elliptical ring fractures around a conical depression with a central pit, bears a close resemblance to Icelandic glacier collapse cauldrons produced by subglacial eruptions. Other structures resembling Icelandic cauldrons occur along Europan banded structures, while resurgence of ice rubble within collapse structures may produce certain types of chaos region. More general contraction of the ice mantle

  3. Chemical modifications of liquid natural rubber

    Science.gov (United States)

    Azhar, Nur Hanis Adila; Rasid, Hamizah Md; Yusoff, Siti Fairus M.

    2016-11-01

    Liquid natural rubber (LNR) was synthesized via photosentisized degradation of natural rubber (NR). LNR was modified into epoxidized liquid natural rubber (LENR) and hydroxylated liquid natural rubber (LNR-OH) using Na2WO4/CH3COOH/H2O2 catalytic system. Chemical structures of LNR and modified LNRs were characterized using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and 1H Nuclear Magnetic Resonance (NMR) spectroscopies. Integration of 1H NMR was used to calculate the epoxy content (%) of LENR. 1H NMR detected the formation of LNR-OH after prolonged heating and increased of catalyst in oxidation reaction.

  4. The Liquid State

    Indian Academy of Sciences (India)

    like iron, aluminium, lead, zinc, etc .. Metals are cast ... dropping molten liquid of the alloys on a rapidly spinning copper wheel. ... Ed. Computer simulation studies in ... liquids, modelling ofliquids and study of the dynamic behaviour of liquids ...

  5. Remotely controllable liquid marbles

    KAUST Repository

    Zhang, Lianbin; Cha, Dong Kyu; Wang, Peng

    2012-01-01

    Liquid droplets encapsulated by self-organized hydrophobic particles at the liquid/air interface - liquid marbles - are prepared by encapsulating water droplets with novel core/shell-structured responsive magnetic particles, consisting of a

  6. Membrane assisted liquid-liquid extraction of cerium

    International Nuclear Information System (INIS)

    Soldenhoff, K.M.

    2000-02-01

    Membrane assisted liquid-liquid extraction of cerium was investigated, with emphasis placed on the study of the reaction chemistry and the kinetics of non-dispersive solvent extraction and stripping with microporous membranes. A bulk liquid membrane process was developed for the purification of cerium(IV) from sulfate solutions containing other rare earth elements. The cerium process was studied in both a flat sheet contained liquid membrane configuration and with hollow fibre contactors. Di-2-ethylhexyl phosphoric acid (DEHPA) was identified as a suitable extractant for cerium(IV) from sulfuric acid solution, with due consideration of factors such as extraction ability, resistance to degradation, solvent selectivity and potential for sulfate transfer into a strip solution. A detailed study of the extraction of cerium(IV) with DEHPA defined the extraction reaction chemistry. The Ce/DEHPA/sulfate system was also investigated with a flat sheet bulk liquid membrane configuration, using both sulfuric and hydrochloric acid as receiver solutions. These tests identified that hydrophobic membranes provide better mass transfer for extraction and hydrophilic membranes are better for stripping. The presence of an impurity, mono 2-ethylhexyl phosphoric acid (MEHPA), was found to have a dramatic accelerating effect on the rate of the chemical extraction reaction. This was attributed to its higher interfacial activity and population compared to DEHPA, and the fact that MEHPA was also found to be an active carrier for cerium(IV). The mass transfer rate of membrane assisted extraction and stripping of cerium, using hydrophobic and hydrophilic microporous membranes, respectively, was investigated using a modified Lewis-type cell. It was quantitatively demonstrated that the extraction process was mainly controlled by membrane diffusion and the stripping process was controlled by the chemical reaction rate, with membrane diffusion becoming important at low distribution coefficients

  7. Choline-based biodegradable ionic liquid catalyst for Mannich-type

    Indian Academy of Sciences (India)

    Choline-based biodegradable ionic liquid catalyst for Mannich-type reaction ... Abstract. A three-component Mannich-type reaction of aromatic aldehydes, ketones, and amines was catalyzed by a novel ... Journal of Chemical Sciences | News.

  8. Biaxial nematic liquid crystals theory, simulation and experiment

    CERN Document Server

    Luckhurst, Geoffrey R

    2015-01-01

    Liquid Crystals are a state of matter that have properties between those of conventional liquid and those of a solid crystal. Thermotropic liquid crystals react to changes in temperature or, in some cases, pressure. The reaction of lyotropic liquid crystals, which are used in the manufacture of soaps and detergents, depends on the type of solvent they are mixed with. Since the accidental discovery of the chiral nematic (ordered) phase in 1888 many liquid crystal phases have been found, sometimes by chance and sometimes by design. The existence of one such phase was predicted by Freiser in 197

  9. (Liquid + liquid) equilibria of perfluorocarbons with fluorinated ionic liquids

    International Nuclear Information System (INIS)

    Martinho, S.; Araújo, J.M.M.; Rebelo, L.P.N.; Pereiro, A.B.; Marrucho, I.M.

    2013-01-01

    Highlights: • (Liquid + liquid) equilibria perfluorocarbons and fluorinated ionic liquids. • Non-Random Two Liquid model was successfully applied. • Thermodynamic functions that describe the solvation process were calculated. -- Abstract: In order to evaluate the feasibility of partially replace perfluorocarbons (PFCs) with fluorinated ionic liquids (FILs) in PFCs-in-water emulsions, usually used for biomedical purposes, herein the (liquid + liquid) phase equilibria of FILs containing fluorinated chains longer than four carbons with PFCs were carried out in a wide range of temperatures. With this goal in mind, two PFCs (perfluorooctane and perfluorodecalin) were selected and the (liquid + liquid) equilibria of the binary mixtures of these PFCs and FILs were studied at atmospheric pressure in a temperature range from T (293.15 to 343.15) K. For these studies, FILs containing ammonium, pyridinium and imidazolium cations and different anions with fluorocarbon alkyl chains between 4 and 8 were included. Additionally, Non-Random Two Liquid (NRTL) thermodynamic model was successfully applied to correlate the behaviour of the PFCs + FILs binary mixtures. Moreover, thermodynamic functions that describe the solvation process were calculated from the experimental data

  10. Applications of ionic liquids in polymer science and technology

    CERN Document Server

    2015-01-01

    This book summarizes the latest knowledge in the science and technology of ionic liquids and polymers in different areas. Ionic liquids (IL) are actively being investigated in polymer science and technology for a number of different applications. In the first part of the book the authors present the particular properties of ionic liquids as speciality solvents. The state-of-the art in the use of ionic liquids in polymer synthesis and modification reactions including polymer recycling is outlined. The second part focuses on the use of ionic liquids as speciality additives such as plasticizers or antistatic agents.  The third part examines the use of ionic liquids in the design of functional polymers (usually called polymeric ionic liquids (PIL) or poly(ionic liquids)). Many important applications in diverse scientific and industrial areas rely on these polymers, like polymer electrolytes in electrochemical devices, building blocks in materials science, nanocomposites, gas membranes, innovative anion sensitive...

  11. Significant Improvement of Catalytic Efficiencies in Ionic Liquids

    International Nuclear Information System (INIS)

    Song, Choong Eui; Yoon, Mi Young; Choi, Doo Seong

    2005-01-01

    The use of ionic liquids as reaction media can confer many advantages upon catalytic reactions over reactions in organic solvents. In ionic liquids, catalysts having polar or ionic character can easily be immobilized without additional structural modification and thus the ionic solutions containing the catalyst can easily be separated from the reagents and reaction products, and then, be reused. More interestingly, switching from an organic solvent to an ionic liquid often results in a significant improvement in catalytic performance (e.g., rate acceleration, (enantio)selectivity improvement and an increase in catalyst stability). In this review, some recent interesting results which can nicely demonstrate these positive 'ionic liquid effect' on catalysis are discussed

  12. Study on liquid-metal MHD power generation system with two-phase natural circulation. Applicability to fast reactor conditions

    International Nuclear Information System (INIS)

    Saito, Masaki

    2000-03-01

    Feasibility study of the liquid-metal MHD power generation system combined with the high-density two-phase natural circulation has been performed for the applicability to the simple, autonomic energy conversion system of the liquid-metal cooled fast reactor. The present system has many promising aspects not only in the energy conversion process, but also in safety and economical improvements of the liquid-metal cooled fast reactor. For example, the high cycle efficiency can be expected because of the similarity of the present cycle to the Ericsson cycle. Sodium-Water Interaction problem can be excluded by proper combination of the working fluids. As the economical feature, the present system is so simple that the liquid-metal main circular pump, the steam turbine generator, and even the steam generator can be excluded if the thermodynamic working fluid is injected directly into the high temperature liquid metal MHD working fluid. In addition, the present system has the potential to be applied to various heat sources including solar energy because of the high flexibility of the operation temperature. In the present paper, as the first step of the feasibility study, the cycle analyses were performed to examine the effects of the main system parameters on the fundamental characteristics of the system. It is found that the cycle efficiency of the present system is enough competitive with that of the conventional steam turbine system. It is, however, found that the cycle efficiency depends strongly on the gas-liquid slip ratio in the two-phase flow channel. As the conclusions, it is recommended to perform experimental study to obtain the fundamental data, such as the gas-liquid slip ratio in the high-density liquid-metal two-phase natural circulation. (author)

  13. The Influence of Particle Charge on Heterogeneous Reaction Rate Coefficients

    Science.gov (United States)

    Aikin, A. C.; Pesnell, W. D.

    2000-01-01

    The effects of particle charge on heterogeneous reaction rates are presented. Many atmospheric particles, whether liquid or solid are charged. This surface charge causes a redistribution of charge within a liquid particle and as a consequence a perturbation in the gaseous uptake coefficient. The amount of perturbation is proportional to the external potential and the square of the ratio of debye length in the liquid to the particle radius. Previous modeling has shown how surface charge affects the uptake coefficient of charged aerosols. This effect is now included in the heterogeneous reaction rate of an aerosol ensemble. Extension of this analysis to ice particles will be discussed and examples presented.

  14. Ionic Liquids: The Synergistic Catalytic Effect in the Synthesis of Cyclic Carbonates

    Directory of Open Access Journals (Sweden)

    Flora T.T. Ng

    2013-10-01

    Full Text Available This review presents the synergistic effect in the catalytic system of ionic liquids (ILs for the synthesis of cyclic carbonate from carbon dioxide and epoxide. The emphasis of this review is on three aspects: the catalytic system of metal-based ionic liquids, the catalytic system of hydrogen bond-promoted ionic liquids and supported ionic liquids. Metal and ionic liquids show a synergistic effect on the cycloaddition reactions of epoxides. The cations and anions of ionic liquids show a synergistic effect on the cycloaddition reactions. The functional groups in cations or supports combined with the anions have a synergistic effect on the cycloaddition reactions. Synergistic catalytic effects of ILs play an important role of promoting the cycloaddition reactions of epoxides. The design of catalytic system of ionic liquids will be possible if the synergistic effect on a molecular level is understood.

  15. Kinetic of liquid-liquid extraction for uranyl nitrate and actinides (III) and lanthanides (III) nitrates by amide extractants

    International Nuclear Information System (INIS)

    Toulemonde, V.; CEA Centre d'Etudes de la Vallee du Rhone, 30 -Marcoule

    1995-01-01

    The kinetics of liquid-liquid extraction by amide extractants have been investigated for uranyl nitrate (monoamide extractants), actinides (III) and lanthanides (III) nitrates (diamide extractants). The transfer of the metallic species from the aqueous phase to the organic phase was studied using two experimental devices: ARMOLLEX (Argonne Modified Lewis cell for Liquid Liquid Extraction) and RSC (Rotating Stabilized Cell). The main conclusions are: for the extraction of uranyl nitrate by DEHDMBA monoamide, the rate-controlling step is the complexation of the species at the interface of the two liquids. Thus, an absorption-desorption (according to Langmuir theory) reaction mechanism was proposed; for the extraction of actinides (III) and lanthanides (III) nitrates in nitric acid media by DMDBTDMA diamide, the kinetic is also limited by interfacial reactions. The behavior of Americium and Europium is very similar as fare as their reaction kinetics are concerned. (author)

  16. CASH AND LIQUIDITY/LIQUIDITY AND LIQUIDITY RATIO

    Directory of Open Access Journals (Sweden)

    BEATRIX LIGHEZAN BREUER

    2012-12-01

    Full Text Available The present paper aims to present the correlation as well as the differences between liquidity/cash and liquidity ratio in terms of economic entities. Researches on this topic are based on the opinions of some specialists in accounting and in the economic-financial analysis, as well as on the national legal stipulations and the ones set out in the International Accounting Standards, the Financial report, respectively. The object of this paper is represented by the correlation between liquidity/cash and liquidity ratios representing the liquidity as current assets, assets implied in the determination of liquidity ratios. The end of the paper consists of the conclusions drawn from the issues presented in the paper but also our views on this research topic.

  17. SISAK liquid-liquid extraction experiments with preseparated 257Rf

    International Nuclear Information System (INIS)

    Omtvedt, Jon Petter; Alstad, J.; Breivik, H.; Dyve, J.E.; Eberhardt, K.; Folden III, C.M.; Ginter, T.; Gregorich, K.E.; Hult, E.A.; Johansson, M.; Kirbach, U.W.; Lee, D.M.; Mendel, M.; Nahler, A.; Ninov, V.; Omtvedt, L.A.; Patin, J.B.; Skarnemark, G.; Stavsetra, L.; Sudowe, R.; Wiehl, N.; Wierczinski, B.; Wilk, P.A.; Zielinski, P.M.; Kratz, J.V.; Trautmann, N.; Nitsche, H.; Hoffman, D.C.

    2002-01-01

    The SISAK liquid-liquid extraction system was used to extract 4.0-s 257Rf. The 257Rf was produced in the reaction 208Pb(50Ti, 1n)257Rf with 237-MeV beam energy on target, separated in the Berkeley Gas-filled Separator (BGS) and transferred to a gas jet using the Recoil Transfer Chamber (RTC). The activity delivered by the gas jet was dissolved in 6-M HNO3 and Rf was extracted into 0.25-M dibutyl-phosphoric acid in toluene. This was the first time a transactinide, i.e., an element with Z >= 104, was extracted and unequivocally identified by the SISAK system. Thus, this pilot experiment demonstrates that the fast liquid-liquid extraction system SISAK, in combination with liquidscintillation detectors, can be used for investigating the chemical properties of the transactinides. The extraction result is in accordance with the behaviour shown by the Rf group IV homologues Zr and Hf

  18. Alternative route to metal halide free ionic liquids

    International Nuclear Information System (INIS)

    Takao, Koichiro; Ikeda, Yasuhisa

    2008-01-01

    An alternative synthetic route to metal halide free ionic liquids using trialkyloxonium salt is proposed. Utility of this synthetic route has been demonstrated by preparing 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid through the reaction between 1-methylimidazole and triethyloxonium tetra-fluoroborate in anhydrous ether. (author)

  19. An Ionic Liquid Solution of Chitosan as Organocatalyst

    Directory of Open Access Journals (Sweden)

    René Wilhelm

    2013-11-01

    Full Text Available Chitosan, which is derived from the biopolymer chitin, can be readily dissolved in different ionic liquids. The resulting homogeneous solutions were applied in an asymmetric Aldol reaction. Depending on the type of ionic liquid used, high asymmetric inductions were found. The influence of different additives was also studied. The best results were obtained in [BMIM][Br] without an additive.

  20. Selective Oxidative Carbonylation of Aniline to Diphenylurea with Ionic Liquids

    DEFF Research Database (Denmark)

    Zahrtmann, Nanette; Claver, Carmen; Godard, Cyril

    2018-01-01

    A catalytic system for the selective oxidative carbonylation of aniline to diphenylurea based on Pd complexes in combination with imidazolium ionic liquids is presented. Both oxidants, Pd complexes and ionic liquids affect the activity of the reaction while the choice of oxidant determines...

  1. Immobilization of molecular catalysts in supported ionic liquid phases.

    Science.gov (United States)

    Van Doorslaer, Charlie; Wahlen, Joos; Mertens, Pascal; Binnemans, Koen; De Vos, Dirk

    2010-09-28

    In a supported ionic liquid phase (SILP) catalyst system, an ionic liquid (IL) film is immobilized on a high-surface area porous solid and a homogeneous catalyst is dissolved in this supported IL layer, thereby combining the attractive features of homogeneous catalysts with the benefits of heterogeneous catalysts. In this review reliable strategies for the immobilization of molecular catalysts in SILPs are surveyed. In the first part, general aspects concerning the application of SILP catalysts are presented, focusing on the type of catalyst, support, ionic liquid and reaction conditions. Secondly, organic reactions in which SILP technology is applied to improve the performance of homogeneous transition-metal catalysts are presented: hydroformylation, metathesis reactions, carbonylation, hydrogenation, hydroamination, coupling reactions and asymmetric reactions.

  2. Experimental study on desulfurization efficiency and gas-liquid mass transfer in a new liquid-screen desulfurization system

    International Nuclear Information System (INIS)

    Sun, Zhongwei; Wang, Shengwei; Zhou, Qulan; Hui, Shi'en

    2010-01-01

    This paper presents a new liquid-screen gas-liquid two-phase flow pattern with discarded carbide slag as the liquid sorbent of sulfur dioxide (SO 2 ) in a wet flue gas desulfurization (WFGD) system. On the basis of experimental data, the correlations of the desulfurization efficiency with flue gas flow rate, slurry flow rate, pH value of slurry and liquid-gas ratio were investigated. A non-dimensional empirical model was developed which correlates the mass transfer coefficient with the liquid Reynolds number, gas Reynolds number and liquid-gas ratio (L/G) based on the available experimental data. The kinetic reaction between the SO 2 and the carbide slag depends on the pressure distribution in this desulfurizing tower, gas liquid flow field, flue gas component, pH value of slurry and liquid-gas ratio mainly. The transient gas-liquid mass transfer involving with chemical reaction was quantified by measuring the inlet and outlet SO 2 concentrations of flue gas as well as the characteristics of the liquid-screen two-phase flow. The mass transfer model provides a necessary quantitative understanding of the hydration kinetics of sulfur dioxide in the liquid-screen flue gas desulfurization system using discarded carbide slag which is essential for the practical application. (author)

  3. PVP存在下液液界面生长法制备硒纳米线%Preparation of Selenium Nanowires by Liquid-liquid Interface Growth in the Presence of Polyvinylpyrrolidone

    Institute of Scientific and Technical Information of China (English)

    张胜义; 张娟; 刘明珠; 朱俊杰; 陈洪渊

    2005-01-01

    Nanowires of trigonal selenium were synthesized in large-scale by two step processes: reaction in homogeneous solution and growth at liquid-liquid interface. Polyvinylpyrrolidone was used as a soft template in the synthesis.

  4. Implied liquidity : towards stochastic liquidity modeling and liquidity trading

    NARCIS (Netherlands)

    Corcuera, J.M.; Guillaume, F.M.Y.; Madan, D.B.; Schoutens, W.

    2010-01-01

    In this paper we introduce the concept of implied (il)liquidity of vanilla options. Implied liquidity is based on the fundamental theory of conic finance, in which the one-price model is abandoned and replaced by a two-price model giving bid and ask prices for traded assets. The pricing is done by

  5. Ion-molecule reactions: their role in radiation chemistry

    International Nuclear Information System (INIS)

    Lias, S.G.; Ausloos, P.

    1975-01-01

    A comprehensive review of ion--molecule reactions is presented, including information from mass spectrometric, organic chemistry, and NMR studies, from theoretical calculations, and from gas and liquid phase radiation chemistry. Special emphasis is placed on interpreting the role of ion--molecule reactions in systems under high energy irradiation. The discussion is presented under the following chapter headings: ion--molecule reactions and their role in radiation chemistry; unimolecular processes: the nature and structure of ionic intermediates in radiolysis; ion lifetimes and the fate of unreactive ions; kinetics and mechanisms of ion--molecule reactions; proton transfer reactions; negative atom and two-atom transfer reactions; condensation reactions; and, association or clustering reactions

  6. Physics of the pion liquid

    International Nuclear Information System (INIS)

    Shuryak, E.V.

    1990-01-01

    Excited hadronic matter in the temperature interval T = 100-200 MeV is not an ideal pion gas, but ratehr a liquid, in which attractive interaction among particles plays an important role. Pion dispersion curve is in this case essentially modified by a kind of collective momentum-dependent potential, which becomes important as the quasipion comes to the boundary of the system. The author shows that these effects can provide an explanation for a number of recent experimental puzzles, in particular, for the observed copious production of soft pions and soft photons in high energy hadronic reactions

  7. Physics of the pion liquid

    International Nuclear Information System (INIS)

    Shuryak, E.V.

    1990-04-01

    Excited hadronic matter in the temperature interval T = 100--200 MeV is not an ideal pion gas, but rather a liquid, in which attractive interaction among particles plays an important role. Pion dispersion curve is in this case essentially modified by a kind of collective momentum-dependent potential, which becomes important as the ''quasipion'' comes to the boundary of the system. We show that effects can provide and explanation for a number of recent experimental puzzles, in particular, for the observed copious production of soft pions and soft photons in high energy hadronic reactions. 31 refs., 13 figs

  8. Hydrogen production from glucose in ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Assenbaum, D.W.; Taccardi, N.; Berger, M.E.M.; Boesmann, A.; Enzenberger, F.; Woelfel, R.; Wasserscheid, P. [Erlangen-Nuernberg Univ. (Germany). Lehrstuhl fuer chemische Reaktionstechnik

    2010-07-01

    technologies suffer from the fact that the overall reaction rates are often restricted by mass and heat transport problems. Lastly, there are severe limitations concerning the feedstock selection as for some important substrates, such as e.g. glucose, the process can only be operated in very diluted systems to avoid rapid tar formation [22,23,24]. In this contribution we describe for the first time a catalytic reaction system producing hydrogen from glucose in astonishingly high selectivities using a single reaction step under very mild conditions. The catalytic reaction system is characterized by its homogeneous nature and comprises a Ru-complex catalyst dissolved and stabilized in an ionic liquid medium. Ionic liquids are salts of melting points below 100 C [25]. These liquid materials have attracted much interest in the last decade as solvents for catalytic reactions [26] and separation technologies (extraction, distillation) [27,28,29,30,31,32]. Besides, these liquids have found industrial applications as process fluids for mechanic [33] and electrochemical applications [34]. Finally, from the pioneering work of Rogers and co-workers, it is known that ionic liquids are able to dissolve significant amounts of water-insoluble biopolymers (such as e.g. cellulose and chitin)[35] and even complex biopolymer mixtures, such as e.g. wood, have been completely dissolved in some ionic liquids [36]. In our specific application, the role of the ionic liquid is threefold: a) the ionic liquid dissolves the carbohydrate starting material thus expanding the range of applicable carbohydrate to water insoluble polymers; b) the ionic liquid provides a medium to dissolve and stabilize the catalyst; c) the ionic liquid dissolves hydrogen at a very low level, so inhibiting any possible collateral hydrogen-consuming process (detailed investigation of the hydrogen solubility in ionic liquids have been reported by e.g. Brennecke and coworkers [37]). (orig.)

  9. Liquid Marble Coalescence and Triggered Microreaction Driven by Acoustic Levitation.

    Science.gov (United States)

    Chen, Zhen; Zang, Duyang; Zhao, Liang; Qu, Mengfei; Li, Xu; Li, Xiaoguang; Li, Lixin; Geng, Xingguo

    2017-06-27

    Liquid marbles show promising potential for application in the microreactor field. Control of the coalescence between two or among multiple liquid marbles is critical; however, the successful merging of two isolated marbles is difficult because of their mechanically robust particle shells. In this work, the coalescence of multiple liquid marbles was achieved via acoustic levitation. The dynamic behaviors of the liquid marbles were monitored by a high-speed camera. Driven by the sound field, the liquid marbles moved toward each other, collided, and eventually coalesced into a larger single marble. The underlying mechanisms of this process were probed via sound field simulation and acoustic radiation pressure calculation. The results indicated that the pressure gradient on the liquid marble surface favors the formation of a liquid bridge between the liquid marbles, resulting in their coalescence. A preliminary indicator reaction was induced by the coalescence of dual liquid marbles, which suggests that expected chemical reactions can be successfully triggered with multiple reagents contained in isolated liquid marbles via acoustic levitation.

  10. Raman spectroscopic study of reaction dynamics

    Science.gov (United States)

    MacPhail, R. A.

    1990-12-01

    The Raman spectra of reacting molecules in liquids can yield information about various aspects of the reaction dynamics. The author discusses the analysis of Raman spectra for three prototypical unimolecular reactions, the rotational isomerization of n-butane and 1,2-difluoroethane, and the barrierless exchange of axial and equatorial hydrogens in cyclopentane via pseudorotation. In the first two cases the spectra are sensitive to torsional oscillations of the gauche conformer, and yield estimates of the torsional solvent friction. In the case of cyclopentane, the spectra can be used to discriminate between different stochastic models of the pseudorotation dynamics, and to determine the relevant friction coefficients.

  11. Catalytic process for tritium exchange reaction

    International Nuclear Information System (INIS)

    Hansoo Lee; Kang, H.S.; Paek, S.W.; Hongsuk Chung; Yang Geun Chung; Sook Kyung Lee

    2001-01-01

    The catalytic activities for a hydrogen isotope exchange were measured through the reaction of a vapor and gas mixture. The catalytic activity showed to be comparable with the published data. Since the gas velocity is relatively low, the deactivation was not found clearly during the 5-hour experiment. Hydrogen isotope transfer experiments were also conducted through the liquid phase catalytic exchange reaction column that consisted of a catalytic bed and a hydrophilic bed. The efficiencies of both the catalytic and hydrophilic beds were higher than 0.9, implying that the column performance was excellent. (author)

  12. Material degradation of liquid organic semiconductors analyzed by nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Tatsuya; Yamamoto, Junichi; Fukuchi, Masashi; Kaji, Hironori, E-mail: kaji@scl.kyoto-u.ac.jp [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Hirata, Shuzo; Jung, Heo Hyo; Adachi, Chihaya [Center for Organic Photonics and Electronics Research (OPERA), Kyusyu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Hirata, Osamu; Shibano, Yuki [Nissan Chemical Industries, LTD, 722-1 Tsuboi, Funabashi 274-8507 (Japan)

    2015-08-15

    Liquid organic light-emitting diodes (liquid OLEDs) are unique devices consisting only of liquid organic semiconductors in the active layer, and the device performances have been investigated recently. However, the device degradation, especially, the origin has been unknown. In this study, we show that material degradation occurs in liquid OLEDs, whose active layer is composed of carbazole with an ethylene glycol chain. Nuclear magnetic resonance (NMR) experiments clearly exhibit that the dimerization reaction of carbazole moiety occurs in the liquid OLEDs during driving the devices. In contrast, cleavages of the ethylene glycol chain are not detected within experimental error. The dimerization reaction is considered to be related to the device degradation.

  13. Probing Electrochemical Reactions at a Plasma-Liquid Interface

    Science.gov (United States)

    2015-03-16

    shift in the absorption spectrum. However, unlike conventional electrochemical systems with a solid cathode , the electrons enter the solution with...yields of the well-understood reduction of silver (Ag+) were measured. In electrochemistry, metals are electrodeposited on a substrate and the weight is...nanoparticles, which can disperse and in some cases dissolve. In order to measure the weight in a manner similar to electrodeposition experiments, we

  14. Electron reactions in model liquids and biological systems

    International Nuclear Information System (INIS)

    Bakale, G.; Gregg, E.C.

    1982-01-01

    Progress is reported in the following studies: (1) Field-dependent electron attachment; (2) Dependence of electron attachment rate on electron-acceptor dipole moment; (3) Electron attachment in i-octane/TMS mixtures; (4) Electron attachment/detachment equilibria; (5) Electron attachment to reversed micelles; (6) Electron attachment to chemical carcinogens; (7) Radiation-induced bacterial mutagenesis; and (8) Bacterial mutagenicity of nitrobenzene derivatives. 14 references

  15. Reaction between barium and nitrogen in liquid sodium

    International Nuclear Information System (INIS)

    Addison, C.C.; Pulham, R.J.; Trevillion, E.A.

    1975-01-01

    Nitrogen in increasing amounts has been added to separate solutions of barium in sodium of constant composition (ca.4.40 mol % Ba) at 300 0 C. After rendering each mixture homogenous using an electromagnetic pump, filtration, and nitrogen analysis, all the N 2 added has been found in solution up to a solution composition approximating to Ba 4 N (i.e. 1.1 mol % N) beyond which the quantity of dissolved N 2 decreases progressively due to precipitation of the nitride Ba 2 N. The solubilization is interpreted in terms of strong preferential solvation of the nitride ion by barium cations. (author)

  16. Studies on Hydrogenation of Liquid Natural Rubber Using Diimide

    Directory of Open Access Journals (Sweden)

    Nur Hanis Adila Azhar

    2015-01-01

    Full Text Available Liquid natural rubber (LNR is a depolymerized natural rubber (NR which consists of shorter polymeric chains and lower molecular weight (Mw90% was achieved by manipulating the reaction parameters such as sources of diimide, TSH concentration, solvent, and reaction time. The optimum condition was 3 : 1 weight ratio of TSH/LNR in o-xylene at 130°C in 4-hour reaction period.

  17. Liquid waste sampling device

    International Nuclear Information System (INIS)

    Kosuge, Tadashi

    1998-01-01

    A liquid pumping pressure regulator is disposed on the midway of a pressure control tube which connects the upper portion of a sampling pot and the upper portion of a liquid waste storage vessel. With such a constitution, when the pressure in the sampling pot is made negative, and liquid wastes are sucked to the liquid pumping tube passing through the sampling pot, the difference between the pressure on the entrance of the liquid pumping pressure regulator of the pressure regulating tube and the pressure at the bottom of the liquid waste storage vessel is made constant. An opening degree controlling meter is disposed to control the degree of opening of a pressure regulating valve for sending actuation pressurized air to the liquid pumping pressure regulator. Accordingly, even if the liquid level of liquid wastes in the liquid waste storage vessel is changed, the height for the suction of the liquid wastes in the liquid pumping tube can be kept constant. With such procedures, sampling can be conducted correctly, and the discharge of the liquid wastes to the outside can be prevented. (T.M.)

  18. Treatment and Managing Reactions

    Science.gov (United States)

    ... of reactions. Learn more here. Milk Egg Peanut Tree Nuts Soy Wheat Fish Shellfish Sesame Other Food ... a severe reaction. Consider wearing an emergency medical identification (e.g., bracelet, other jewelry). What to Read ...

  19. Microfluidic chemical reaction circuits

    Science.gov (United States)

    Lee, Chung-cheng [Irvine, CA; Sui, Guodong [Los Angeles, CA; Elizarov, Arkadij [Valley Village, CA; Kolb, Hartmuth C [Playa del Rey, CA; Huang, Jiang [San Jose, CA; Heath, James R [South Pasadena, CA; Phelps, Michael E [Los Angeles, CA; Quake, Stephen R [Stanford, CA; Tseng, Hsian-rong [Los Angeles, CA; Wyatt, Paul [Tipperary, IE; Daridon, Antoine [Mont-Sur-Rolle, CH

    2012-06-26

    New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

  20. Preequilibrium Nuclear Reactions

    International Nuclear Information System (INIS)

    Strohmaier, B.

    1988-01-01

    After a survey on existing experimental data on precompound reactions and a description of preequilibrium reactions, theoretical models and quantum mechanical theories of preequilibrium emission are presented. The 25 papers of this meeting are analyzed separately

  1. Managing Your Emotional Reactions

    Science.gov (United States)

    ... Videos for Educators Search English Español Managing Your Emotional Reactions KidsHealth / For Teens / Managing Your Emotional Reactions ... Think about what you might do next time. Emotions 101 The skills we use to manage our ...

  2. Heavy ion transfer reactions

    Indian Academy of Sciences (India)

    array (CLARA), extensive investigations of nuclear structure and reaction dynamics have been carried out. In the present paper aspects of these studies will be presented, focussing more closely on the reaction mechanism, in particular on the ...

  3. Asymmetric Michael Addition Mediated by Chiral Ionic Liquids

    Science.gov (United States)

    Suzuki, Yumiko

    2018-01-01

    Chiral ionic liquids with a focus on their applications in asymmetric Michael additions and related reactions were reviewed. The examples were classified on the basis of the mode of asymmetric induction (e.g., external induction/non-covalent interaction or internal induction/covalent bond formation), the roles in reactions (as a solvent or catalyst), and their structural features (e.g., imidazolium-based chiral cations, other chiral oniums; proline derivatives). Most of the reactions with high chiral induction are Michael addition of ketones or aldehydes to chalcones or nitrostyrenes where proline-derived chiral ionic liquids catalyze the reaction through enamine/ iminium formation. Many reports demonstrate the recyclability of ionic liquid-tagged pyrrolidines. PMID:29861702

  4. Asymmetric Michael Addition Mediated by Chiral Ionic Liquids.

    Science.gov (United States)

    Suzuki, Yumiko

    2018-06-01

    Chiral ionic liquids with a focus on their applications in asymmetric Michael additions and related reactions were reviewed. The examples were classified on the basis of the mode of asymmetric induction (e.g., external induction/non-covalent interaction or internal induction/covalent bond formation), the roles in reactions (as a solvent or catalyst), and their structural features (e.g., imidazolium-based chiral cations, other chiral oniums; proline derivatives). Most of the reactions with high chiral induction are Michael addition of ketones or aldehydes to chalcones or nitrostyrenes where proline-derived chiral ionic liquids catalyze the reaction through enamine/ iminium formation. Many reports demonstrate the recyclability of ionic liquid-tagged pyrrolidines.

  5. CASH AND LIQUIDITY/LIQUIDITY AND LIQUIDITY RATIO

    OpenAIRE

    ADELA BREUER; MIHAELA LESCONI FRUMUSANU; BEATRIX LIGHEZAN BREUER; ANDRA MANCIU

    2012-01-01

    The present paper aims to present the correlation as well as the differences between liquidity/cash and liquidity ratio in terms of economic entities. Researches on this topic are based on the opinions of some specialists in accounting and in the economic-financial analysis, as well as on the national legal stipulations and the ones set out in the International Accounting Standards, the Financial report, respectively. The object of this paper is represented by the correlation between liquidit...

  6. Buckling of liquid columns

    NARCIS (Netherlands)

    Habibi, M.; Rahmani, Y.; Bonn, D.; Ribe, N.M.

    2010-01-01

    Under appropriate conditions, a column of viscous liquid falling onto a rigid surface undergoes a buckling instability. Here we show experimentally and theoretically that liquid buckling exhibits a hitherto unsuspected complexity involving three different modes—viscous, gravitational, and

  7. Liquid Effluent Retention Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Liquid Effluent Retention Facility (LERF) is located in the central part of the Hanford Site. LERF is permitted by the State of Washington and has three liquid...

  8. Thermonuclear reaction rates. III

    International Nuclear Information System (INIS)

    Harris, M.J.; Fowler, W.A.; Caughlan, G.R.; Zimmerman, B.A.

    1983-01-01

    Stellar thermonuclear reaction rates are revised and updated, adding a number of new important reaction rates. Several reactions with large negative Q-values are included, and examples of them are discussed. The importance of the decay rates for Mg-26(p,n) exp 26 Al and Al-26(n,p) exp 26 Mg for stellar studies is emphasized. 19 references

  9. Maillard Reaction: review

    Directory of Open Access Journals (Sweden)

    Júlia d'Almeida Francisquini

    2017-11-01

    Full Text Available Maillard reaction is an important subject of study in food science and technology and different areas of knowledge are involved such as chemistry, food engineering, nutrition and food technology. The objective of this paper is to present the basic concepts of the Maillard reaction, such as the reaction stages, the main compounds producced and some technological consequences for dairy products.

  10. Resonant thermonuclear reaction rate

    International Nuclear Information System (INIS)

    Haubold, H.J.; Mathai, A.M.

    1986-01-01

    Basic physical principles for the resonant and nonresonant thermonuclear reaction rates are applied to find their standard representations for nuclear astrophysics. Closed-form representations for the resonant reaction rate are derived in terms of Meijer's G-function. Analytic representations of the resonant and nonresonant nuclear reaction rates are compared and the appearance of Meijer's G-function is discussed in physical terms

  11. Modeling non-adiabatic photoexcited reaction dynamics in condensed phases

    International Nuclear Information System (INIS)

    Coker, D.F.

    2003-01-01

    Reactions of photoexcited molecules, ions, and radicals in condensed phase environments involve non-adiabatic dynamics over coupled electronic surfaces. We focus on how local environmental symmetries can effect non-adiabatic coupling between excited electronic states and thus influence, in a possibly controllable way, the outcome of photo-excited reactions. Semi-classical and mixed quantum-classical non-adiabatic molecular dynamics methods, together with semi-empirical excited state potentials are used to probe the dynamical mixing of electronic states in different environments from molecular clusters, to simple liquids and solids, and photo-excited reactions in complex reaction environments such as zeolites

  12. Liquid metal cold trap

    International Nuclear Information System (INIS)

    Hundal, R.

    1976-01-01

    A cold trap assembly for removing impurities from a liquid metal is described. A hole between the incoming impure liquid metal and purified outgoing liquid metal acts as a continuous bleed means and thus prevents the accumulation of cover gases within the cold trap assembly

  13. Liquid--liquid contact in vapor explosion

    International Nuclear Information System (INIS)

    Segev, A.

    1978-08-01

    The contact of two liquid materials, one of which is at a temperature substantially above the boiling point of the other, can lead to fast energy conversion and a subsequent shock wave. This well-known phenomenon is called a ''vapor explosion.'' One method of producing intimate, liquid--liquid contact (which is known to be a necessary condition for vapor explosion) is a shock tube configuration. Such experiments in which water was impacted upon molten aluminum showed that very high pressures, even larger than the thermodynamic critical pressure, could occur. The mechanism by which such sharp pressure pulses are generated is not yet clear. In this experiment cold liquids (Freon-11, Freon-22, water, or butanol) were impacted upon various hot materials (mineral oil, silicone oil, water, mercury, molten Wood's metal or molten salt mixture). The main conclusion from the experimental study is that hydrodynamic effects may be very significant in any shock tube analyses, especially when multiple interactions are observed. A theoretical study was performed to check the possibility of vapor film squeezing (between a drop in film boiling and a surface) as a controlling mechanism for making liquid--liquid contact. Using experimental data, the film thickness was calculated and it was found to be too thick for any conceivable film rupture mechanism. It was suggested that the coalescence is a two-stage process, in which the controlling stage depends mainly on temperature and surface properties and can be described as the ability of cold liquid to spread on a hot surface

  14. The influenced of reaction time on the degradation of palm oil empty fruit bunch (EFB) in hydrothermal carbonization

    Science.gov (United States)

    Sarwono, Rakhman; Kurniawan, Hendris Hendarsyah

    2017-11-01

    Hydrothermal carbonization (HTC) of empty fruit bunch (EFB) of palm oil in different reaction times were investigated. Experiments were carried out in an autoclave at different reaction time of 3,6,9, 15, 20, 25 and 40 hours. With a fixed solid/liquid ratio of 5 gram of EFB in 50 ml water as a solvent, and temperature reaction of 250 °C. Increase the reaction time the soluble products are also increased. The liquid products were analyzed using GCMS to determine the chemical composition. The chemical composition were greatly affected by the reaction time. The main component was glycolic acid, by increasing the reaction time made the varieties of chemical compositions in liquid products, especially for the glycolic acid component, it was decreased slightly. The higher heating value (HHV) also increase slighly by increasing the reaction time both solid and liquid products.

  15. Thermodynamic and molecular origin of interfacial rate enhancements and endo-selectivities of a Diels-Alder reaction.

    Science.gov (United States)

    Beniwal, Vijay; Kumar, Anil

    2017-02-08

    Organic reactions in general display large rate accelerations when performed under interfacial conditions, such as on water or at ionic liquid interfaces. However, a clear picture of the physicochemical factors responsible for this large rate enhancements is not available. To gain an understanding of the thermodynamic and molecular origin of these large rate enhancements, we performed a Diels-Alder reaction between cyclopentadiene and methyl acrylate at ionic liquid/n-hexane interfaces. This study describes, for the first time, a methodology for the calculation of the activation parameters of an interfacial reaction. It has been seen that the energy of activation for an interfacial reaction is much smaller than that of the corresponding homogeneous reaction, resulting into the large rate acceleration for the interfacial reaction. Furthermore, the study describes the effects of the alkyl chain length of ionic liquid cations, the extent of heterogeneity, and the polarity of ionic liquids on the rate constants and stereoselectivity of the reaction.

  16. Insights into the mechanisms on chemical reactions: reaction paths for chemical reactions

    International Nuclear Information System (INIS)

    Dunning, T.H. Jr.; Rosen, E.; Eades, R.A.

    1987-01-01

    We report reaction paths for two prototypical chemical reactions: Li + HF, an electron transfer reaction, and OH + H 2 , an abstraction reaction. In the first reaction we consider the connection between the energetic terms in the reaction path Hamiltonian and the electronic changes which occur upon reaction. In the second reaction we consider the treatment of vibrational effects in chemical reactions in the reaction path formalism. 30 refs., 9 figs

  17. Liquid to liquid extraction and liquid chromatography-tandem mass spectrometry determination of hainanmycin in feed.

    Science.gov (United States)

    Wang, Ze Ping; Shen, Jian Zhong; Linhardt, Robert J; Jiang, Hui; Cheng, Lin Li

    2017-03-01

    Hainanmycin is a new veterinary polyether antibiotic and has few sensitive analytical method in present days. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) relying on multiple reaction monitoring (MRM) detection was developed for analysis of hainanmycin in animal feed. Feed samples were extracted with ethyl acetate and purified by two steps of liquid-liquid extraction (LLE) to get rid of water solvable matrix and lipids one by one. The final simple was analyzed by LC-MS/MS. The LC mobile phase was composed of 0.1% aqueous formic acid and 0.1% formic acidified acetonitrile by gradient elution. Average recoveries ranged from 74.22% to 87.85%, as determined by spiking with 2.0 (LOQ) ∼2500μgkg -1 of hainanmycin. The inter-day and intra-day coefficient of variation was 9.21% to 11.77% and 7.67% to 13.49%, respectively. The limit of detection (LOD) and the limit of quantitation (LOQ) were 0.36μgkg -1 and 2.0μgkg -1 , respectively. Copyright © 2016. Published by Elsevier B.V.

  18. Ultraviolet curing of acrylated liquid natural rubber for surface coating application

    OpenAIRE

    Kannikar Kwanming; Pairote Klinpituksa; Wae-asae Waehamad

    2009-01-01

    Ultraviolet curable acrylated liquid natural rubber was prepared by grafting of photosensitive molecule onto liquid natural rubber for surface coating application. The liquid natural rubber (LNR) was firstly obtained by degradation of natural rubber latex with hydrogen peroxide and cobalt acetylacetonate at 65oC for 72 hrs. The preparation of acrylated natural rubber was carried out by the reaction of acrylic acid and epoxidized liquid natural rubber (ELNR) prior obtained from LNR with formic...

  19. Heterogeneously Catalyzed Oxidation Reactions Using Molecular Oxygen

    DEFF Research Database (Denmark)

    Beier, Matthias Josef

    Heterogeneously catalyzed selective oxidation reactions have attracted a lot of attention in recent time. The first part of the present thesis provides an overview over heterogeneous copper and silver catalysts for selective oxidations in the liquid phase and compared the performance and catalytic...... that both copper and silver can function as complementary catalyst materials to gold showing different catalytic properties and being more suitable for hydrocarbon oxidation reactions. Potential opportunities for future research were outlined. In an experimental study, the potential of silver as a catalyst...... revealed that all catalysts were more active in combination with ceria nanoparticles and that under the tested reaction conditions silver was equally or even more efficient than the gold catalysts. Calcination at 900 °C of silver on silica prepared by impregnation afforded a catalyst which was used...

  20. On the existence of hot positronium reactions

    International Nuclear Information System (INIS)

    Lazzarini, E.

    1984-01-01

    The existence of hot Ps reactions is nowadays questioned; the controversy arises from the two models (the Ore gap and the spur theories) advanced in order to explain the mechanism of the positronium formation and of its inhibition in liquids by dissolution of certain compounds. The hypothesis of the hot Ps reactions was initially advanced as an additional statement for explaining the inhibition phenomenon within the framework of the Ore gap theory, but it is not considered necessary for the spur theory. The present paper is chiefly intended as a presentation of this particular aspect of Ps chemistry to hot atom chemists unspecialized in the field. The reader is assumed to be familiar with the basic physics and experimental methods used in positronium chemistry. Contents: positrons and positronium formation; inhibition and enhancement of Ps formation in solutions; positronium reactions in gases. (Auth.)