WorldWideScience

Sample records for stable water injection

  1. Stable isotope reactive transport modeling in water-rock interactions during CO2 injection

    Science.gov (United States)

    Hidalgo, Juan J.; Lagneau, Vincent; Agrinier, Pierre

    2010-05-01

    Stable isotopes can be of great usefulness in the characterization and monitoring of CO2 sequestration sites. Stable isotopes can be used to track the migration of the CO2 plume and identify leakage sources. Moreover, they provide unique information about the chemical reactions that take place on the CO2-water-rock system. However, there is a lack of appropriate tools that help modelers to incorporate stable isotope information into the flow and transport models used in CO2 sequestration problems. In this work, we present a numerical tool for modeling the transport of stable isotopes in groundwater reactive systems. The code is an extension of the groundwater single-phase flow and reactive transport code HYTEC [2]. HYTEC's transport module was modified to include element isotopes as separate species. This way, it is able to track isotope composition of the system by computing the mixing between the background water and the injected solution accounting for the dependency of diffusion on the isotope mass. The chemical module and database have been expanded to included isotopic exchange with minerals and the isotope fractionation associated with chemical reactions and mineral dissolution or precipitation. The performance of the code is illustrated through a series of column synthetic models. The code is also used to model the aqueous phase CO2 injection test carried out at the Lamont-Doherty Earth Observatory site (Palisades, New York, USA) [1]. References [1] N. Assayag, J. Matter, M. Ader, D. Goldberg, and P. Agrinier. Water-rock interactions during a CO2 injection field-test: Implications on host rock dissolution and alteration effects. Chemical Geology, 265(1-2):227-235, July 2009. [2] Jan van der Lee, Laurent De Windt, Vincent Lagneau, and Patrick Goblet. Module-oriented modeling of reactive transport with HYTEC. Computers & Geosciences, 29(3):265-275, April 2003.

  2. Reactor water injection facility

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Kazuhiro; Kinoshita, Shoichiro

    1997-05-02

    A steam turbine and an electric generator are connected by way of a speed convertor. The speed convertor is controlled so that the number of rotation of the electric generator is constant irrespective of the speed change of the steam turbine. A shaft coupler is disposed between the turbine and the electric generator or between the turbine and a water injection pump. With such a constitution, the steam turbine and the electric generator are connected by way of the speed convertor, and since the number of revolution of the electric generator is controlled to be constant, the change of the number of rotation of the turbine can be controlled irrespective of the change of the number of rotation of the electric generator. Accordingly, the flow rate of the injection water from the water injection pump to a reactor pressure vessel can be controlled freely thereby enabling to supply stable electric power. (T.M.)

  3. Water injection dredging

    NARCIS (Netherlands)

    Verhagen, H.J.

    2000-01-01

    Some twenty years ago WIS-dredging has been developed in the Netherlands. By injecting water into the mud layer, the water content of the mud becomes higher, it becomes fluid mud and will start to flow. The advantages of this system are that there is no need of transporting the mud in a hopper, and

  4. Cold water injection nozzles

    International Nuclear Information System (INIS)

    Kura, Masaaki; Maeda, Masamitsu; Endo, Takio.

    1979-01-01

    Purpose: To inject cold water in a reactor without applying heat cycles to a reactor container and to the inner wall of a feedwater nozzle by securing a perforated plate at the outlet of the cold water injection nozzle. Constitution: A disc-like cap is secured to the final end of a return nozzle of a control rod drive. The cap prevents the flow of a high temperature water flowing downward in the reactor from entering into the nozzle. The cap is perforated with a plurality of bore holes for injecting cold water into the reactor. The cap is made to about 100 mm in thickness so that the cold water passing through the bore holes is heated by the heat conduction in the cap. Accordingly, the flow of high temperature water flowing downwardly in the reactor is inhibited by the cap from backward flowing into the nozzle. Moreover, the flow of the cold water in the nozzle is controlled and rectified when passed through the bore holes in the cap and then injected into the reactor. (Yoshino, Y.)

  5. Water injection profiling

    International Nuclear Information System (INIS)

    Arnold, D.M.

    1982-01-01

    A method of neutron-gamma logging is described, in which water, injected in a cased well borehole with peforations, is irradiated with neutrons of 10 MeV or greater, and subsequent gamma radiation is detected by a pair of detectors along the borehole. Counting rates of detectors are analyzed in terms of two gamma ray energy windows. Linear flow velocity of fluid moving downward within the casing is used in conjunction with count rate data to determine volume flow rates of water moving in other directions. Apparatus includes a sonde with a neutron source and appropriate gamma sensors

  6. Cooling water injection system

    International Nuclear Information System (INIS)

    Inai, Nobuhiko.

    1989-01-01

    In a BWR type reactor, ECCS system is constituted as a so-called stand-by system which is not used during usual operation and there is a significant discontinuity in relation with the usual system. It is extremely important that ECCS operates upon occurrence of accidents just as specified. In view of the above in the present invention, the stand-by system is disposed along the same line with the usual system. That is, a driving water supply pump for supplying driving water to a jet pump is driven by a driving mechanism. The driving mechanism drives continuously the driving water supply pump in a case if an expected accident such as loss of the function of the water supply pump, as well as during normal operation. That is, all of the water supply pump, jet pump, driving water supply pump and driving mechanism therefor are caused to operate also during normal operation. The operation of them are not initiated upon accident. Thus, the cooling water injection system can perform at high reliability to remarkably improve the plant safety. (K.M.)

  7. Quasi-stable injection channels in a wakefield accelerator

    CERN Document Server

    Wiltshire-Turkay, Mara; Pukhov, Alexander

    2016-01-01

    Particle-driven plasma-wakefield acceleration is a promising alternative to conventional electron acceleration techniques, potentially allowing electron acceleration to energies orders of magnitude higher than can currently be achieved. In this work we investigate the dependence of the energy gain on the position at which electrons are injected into the wake. Test particle simulations show previously unobserved complex structure in the parameter space, with quasi-stable injection channels forming for particles injected in narrow regions away from the centre of the wake. The result is relevant to the planning and tuning of experiments making use of external injection.

  8. Calculation method of water injection forward modeling and inversion process in oilfield water injection network

    Science.gov (United States)

    Liu, Long; Liu, Wei

    2018-04-01

    A forward modeling and inversion algorithm is adopted in order to determine the water injection plan in the oilfield water injection network. The main idea of the algorithm is shown as follows: firstly, the oilfield water injection network is inversely calculated. The pumping station demand flow is calculated. Then, forward modeling calculation is carried out for judging whether all water injection wells meet the requirements of injection allocation or not. If all water injection wells meet the requirements of injection allocation, calculation is stopped, otherwise the demand injection allocation flow rate of certain step size is reduced aiming at water injection wells which do not meet requirements, and next iterative operation is started. It is not necessary to list the algorithm into water injection network system algorithm, which can be realized easily. Iterative method is used, which is suitable for computer programming. Experimental result shows that the algorithm is fast and accurate.

  9. Leaf water stable isotopes and water transport outside the xylem.

    Science.gov (United States)

    Barbour, M M; Farquhar, G D; Buckley, T N

    2017-06-01

    How water moves through leaves, and where the phase change from liquid to vapour occurs within leaves, remain largely mysterious. Some time ago, we suggested that the stable isotope composition of leaf water may contain information on transport pathways beyond the xylem, through differences in the development of gradients in enrichment within the various pathways. Subsequent testing of this suggestion provided ambiguous results and even questioned the existence of gradients in enrichment within the mesophyll. In this review, we bring together recent theoretical developments in understanding leaf water transport pathways and stable isotope theory to map a path for future work into understanding pathways of water transport and leaf water stable isotope composition. We emphasize the need for a spatially, anatomically and isotopically explicit model of leaf water transport. © 2016 John Wiley & Sons Ltd.

  10. Water injection device for reactor container

    International Nuclear Information System (INIS)

    Sakaki, Isao.

    1996-01-01

    A pressure vessel incorporating a reactor core is placed and secured on a pedestal in a dry well of a reactor container. A pedestal water injection line is disposed opened at one end in a pedestal cavity passing through the side wall of the pedestal and led at the other end to the outside of the reactor container. A substitution dry well spray line is connected to a spray header disposed at the upper portion of the dry well. When the pressure vessel should be damaged by a molten reactor core and the molten reactor core should drop to the dry well upon occurrence of an accident, the molten reactor core on the floor of the pedestal is cooled by water injection from the pedestal water injection line. At the same time, the elevation of the pressure and the temperature in the reactor container is suppressed by the water injection of the substitution dry well spray line. This can avoid large scaled release of radioactive materials to the environmental circumference. (I.N.)

  11. Water quality considerations resulting in the impaired injectivity of water injection and disposal wells

    International Nuclear Information System (INIS)

    Bennion, D.B.; Thomas, F.B.; Imer, D.; Ma, T.

    2000-01-01

    An environmentally responsible way to improve hydrocarbon recovery is to maintain pressure by water injection. This is a desirable method because unwanted produced water from oil and gas wells can be re-injected into producing or disposal formations. The success of the operation, however, depends on injecting the necessary volume of water economically, below the fracture gradient pressure of the formation. Well placement, geometry and inherent formation quality and relative permeability characteristics are some of the many other factors which influence the success of any injection project. Poor injection or poor quality of disposal water can also compromise the injectivity for even high quality sandstone or carbonate formations. This would necessitate costly workovers and recompletions. This paper presented some leading edge diagnostic techniques and evaluation methods to determine the quality of injected water. The same techniques could be used to better understand the effect of potential contaminants such as suspended solids, corrosion products, skim/carryover oil and grease, scales, precipitates, emulsions, oil wet hydrocarbon agglomerates and many other conditions which cause injectivity degradation. 14 refs., 1 tab., 15 figs

  12. Inferring foliar water uptake using stable isotopes of water.

    Science.gov (United States)

    Goldsmith, Gregory R; Lehmann, Marco M; Cernusak, Lucas A; Arend, Matthias; Siegwolf, Rolf T W

    2017-08-01

    A growing number of studies have described the direct absorption of water into leaves, a phenomenon known as foliar water uptake. The resultant increase in the amount of water in the leaf can be important for plant function. Exposing leaves to isotopically enriched or depleted water sources has become a common method for establishing whether or not a plant is capable of carrying out foliar water uptake. However, a careful inspection of our understanding of the fluxes of water isotopes between leaves and the atmosphere under high humidity conditions shows that there can clearly be isotopic exchange between the two pools even in the absence of a change in the mass of water in the leaf. We provide experimental evidence that while leaf water isotope ratios may change following exposure to a fog event using water with a depleted oxygen isotope ratio, leaf mass only changes when leaves are experiencing a water deficit that creates a driving gradient for the uptake of water by the leaf. Studies that rely on stable isotopes of water as a means of studying plant water use, particularly with respect to foliar water uptake, must consider the effects of these isotopic exchange processes.

  13. Water injection profiling by nuclear logging

    International Nuclear Information System (INIS)

    Arnold, D.M.

    1980-01-01

    This invention relates to nuclear logging techniques for determining the volume flow rates and flow directions of injected water moving behind a wellbore casing. The apparatus includes a sonde equipped with a neutron source and dual radiation detectors. Oxygen in the neutron irradiated water is transmitted to 16 N and the resultant primary and Compton scattered gamma rays are detected in two energy windows by both detectors. Count rate data is analysed in terms of the windows to obtain linear flow velocities for water flow within and behind the casing. Volume flow rates are determined for upward and downward flow, and horizontal volume flow into the surrounding formation is calculated. A complete injection profile may thus be obtained. (U.K.)

  14. Addiction treatment and stable housing among a cohort of injection drug users.

    Directory of Open Access Journals (Sweden)

    Anita Palepu

    Full Text Available Unstable housing and homelessness is prevalent among injection drug users (IDU. We sought to examine whether accessing addiction treatment was associated with attaining stable housing in a prospective cohort of IDU in Vancouver, Canada.We used data collected via the Vancouver Injection Drug User Study (VIDUS between December 2005 and April 2010. Attaining stable housing was defined as two consecutive "stable housing" designations (i.e., living in an apartment or house during the follow-up period. We assessed exposure to addiction treatment in the interview prior to the attainment of stable housing among participants who were homeless or living in single room occupancy (SRO hotels at baseline. Bivariate and multivariate associations between the baseline and time-updated characteristics and attaining stable housing were examined using Cox proportional hazard regression models.Of the 992 IDU eligible for this analysis, 495 (49.9% reported being homeless, 497 (50.1% resided in SRO hotels, and 380 (38.3% were enrolled in addiction treatment at the baseline interview. Only 211 (21.3% attained stable housing during the follow-up period and of this group, 69 (32.7% had addiction treatment exposure prior to achieving stable housing. Addiction treatment was inversely associated with attaining stable housing in a multivariate model (adjusted hazard ratio [AHR]=0.71; 95% CI: 0.52-0.96. Being in a partnered relationship was positively associated with the primary outcome (AHR=1.39; 95% CI: 1.02-1.88. Receipt of income assistance (AHR=0.65; 95% CI: 0.44-0.96, daily crack use (AHR=0.69; 95% CI: 0.51-0.93 and daily heroin use (AHR=0.63; 95% CI: 0.43-0.92 were negatively associated with attaining stable housing.Exposure to addiction treatment in our study was negatively associated with attaining stable housing and may have represented a marker of instability among this sample of IDU. Efforts to stably house this vulnerable group may be occurring in contexts

  15. Analysis of Dynamic Characteristics of Water Injection Pump

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Myeong; Lee, Jeong Hoon; Ha, Jeong Min; Ahn, Byung Hyun; Kim, Won Cheol; Choi, Byeong Keun [Gyeongsang Nat' l Univ., Jinju (Korea, Republic of)

    2013-12-15

    Water injection pump outputs oil with high pressure during this process, seawater is injected into the well to recover the well pressure and maintain high productivity. A water injection pump has high productivity, and herefore, it serves as a key piece of equipment in marine plants. In this light, water injection pumps are being studied widely in industry. In this study, the rotor dynamics is analyzed to determine the natural frequency according to the bearing stiffness and operation speed change. This study aims to establish the pump reliability through critical speed, stability, and unbalance response analysis.

  16. Steam injection into water-saturated porous rock

    NARCIS (Netherlands)

    Bruining, J.; Marchesin, D.; Duijn, van C.J.

    2003-01-01

    We formulate conservation laws governing steam injection in a linear porous medium containing water. Heat losses to the outside are neglected. We find a complete and systematic description of all solutions of the Riemann problem for the injection of a mixture of steam and water into a

  17. Multiturn extraction and injection by means of adiabatic capture in stable islands of phase space

    Directory of Open Access Journals (Sweden)

    R. Cappi

    2004-02-01

    Full Text Available Recently a novel approach has been proposed for performing multiturn extraction from a circular machine. Such a technique consists of splitting the beam by means of stable islands created in transverse phase space by magnetic elements creating nonlinear fields, such as sextupoles and octupoles. Provided a slow time variation of the linear tune is applied, adiabatic with respect to the betatron motion, the islands can be moved in phase space and eventually charged particles may be trapped inside the stable structures. This generates a certain number of well-separated beamlets. Originally, this principle was successfully tested using a fourth-order resonance. In this paper the approach is generalized by considering other types of resonances as well as the possibility of performing multiple multiturn extractions. The results of numerical simulations are presented and described in detail. Of course, by time reversal, the proposed approach could be used also for multiturn injection.

  18. Stable sonoluminescence within a water hammer tube.

    Science.gov (United States)

    Chakravarty, Avik; Georghiou, Theo; Phillipson, Tacye E; Walton, Alan J

    2004-06-01

    The sonoluminescence (SL) from the collapse of a single gas bubble within a liquid can be produced repetitively using an acoustic resonator. An alternative technique using a water hammer tube, producing SL from bubbles of greater size, is described here. A sealed vertical tube partly filled with a liquid and a gas at low pressure is subjected to vertical vibrations. The oscillation of the pressure within the liquid column, due to inertial forces, excites cavitation bubbles to grow and collapse. Rotation is used to confine the bubbles to the axis of the tube. Bright SL emissions were observed in a number of liquids. Repetitive emission was produced from bubbles in condensed phosphoric acid. Bubbles of 0.4 mm ambient radius (containing 2x 10(14) xenon atoms) were excited by vibration at 35 Hz. Approximately 10(12) photons were emitted per collapse in the range 400-700 nm (over four orders of magnitude greater than the brightest SL reported previously), corresponding to a 1% efficiency of the conversion of mechanical energy into light.

  19. Radiotracer investigations in oil production and water injection wells

    International Nuclear Information System (INIS)

    Eapen, A.C.; Jain, S.K.; Kirti

    1977-01-01

    Injection of gamma emitting radiotracers into oil wells followed by logging provides information on several aspects such as the identification of zones of seepage of water in the water injection wells and also the location of source of water entering oil producting wells. The experience gained in the application of bromine-82 and rubidium-86 as radiotracers in such studies at the Ankleshwar and Kalol oil fields in Gujarat and Nazira in Assam has been briefly reported. (author)

  20. Particle retention in porous media: Applications to water injectivity decline

    Energy Technology Data Exchange (ETDEWEB)

    Wennberg, Kjell Erik

    1998-12-31

    This thesis studies the problem of migration and deposition of colloidal particles within porous media, theoretically and by computerized simulation. Special emphasis is put on the prediction of injectivity decline in water injection wells due to inherent particles in the injection water. The study of particle deposition within porous media requires a correct prediction of the deposition rate or filtration coefficient. A thorough review of the modeling approaches used in the past are combined with new ideas in order to arrive at an improved model for the prediction of the filtration coefficient. A new way of determining the transition time for the dominant deposition mechanism to change from internal deposition to external cake formation is proposed. From this fundamental theory, equations are given for water injectivity decline predictions. A computer program called WID for water injectivity decline predictions was developed. Using water quality, formation properties, injection rate/pressure and completion information as input, WID predicts decline in vertical and horizontal injection wells with openhole, perforated and fractured completions. The calculations agree fairly well with field data; in some cases the agreement is excellent. A poor match in a few cases indicates that more mechanisms may be responsible for injectivity decline than those presently accounted for by the simulator. The second part of the study deals with a theoretical investigation of the multi-dimensional nature of particle deposition in porous media. 112 refs., 100 figs., 9 tabs.

  1. Reduction of Altitude Diffuser Jet Noise Using Water Injection

    Science.gov (United States)

    Allgood, Daniel C.; Saunders, Grady P.; Langford, Lester A.

    2011-01-01

    A feasibility study on the effects of injecting water into the exhaust plume of an altitude rocket diffuser for the purpose of reducing the far-field acoustic noise has been performed. Water injection design parameters such as axial placement, angle of injection, diameter of injectors, and mass flow rate of water have been systematically varied during the operation of a subscale altitude test facility. The changes in acoustic far-field noise were measured with an array of free-field microphones in order to quantify the effects of the water injection on overall sound pressure level spectra and directivity. The results showed significant reductions in noise levels were possible with optimum conditions corresponding to water injection at or just upstream of the exit plane of the diffuser. Increasing the angle and mass flow rate of water injection also showed improvements in noise reduction. However, a limit on the maximum water flow rate existed as too large of flow rate could result in un-starting the supersonic diffuser.

  2. Economics of water injected air screw compressor systems

    Science.gov (United States)

    Venu Madhav, K.; Kovačević, A.

    2015-08-01

    There is a growing need for compressed air free of entrained oil to be used in industry. In many cases it can be supplied by oil flooded screw compressors with multi stage filtration systems, or by oil free screw compressors. However, if water injected screw compressors can be made to operate reliably, they could be more efficient and therefore cheaper to operate. Unfortunately, to date, such machines have proved to be insufficiently reliable and not cost effective. This paper describes an investigation carried out to determine the current limitations of water injected screw compressor systems and how these could be overcome in the 15-315 kW power range and delivery pressures of 6-10 bar. Modern rotor profiles and approach to sealing and cooling allow reasonably inexpensive air end design. The prototype of the water injected screw compressor air system was built and tested for performance and reliability. The water injected compressor system was compared with the oil injected and oil free compressor systems of the equivalent size including the economic analysis based on the lifecycle costs. Based on the obtained results, it was concluded that water injected screw compressor systems could be designed to deliver clean air free of oil contamination with a better user value proposition than the oil injected or oil free screw compressor systems over the considered range of operations.

  3. Stable lead isotopes as a tracer in coastal waters

    International Nuclear Information System (INIS)

    Stukas, V.J.; Wong, C.S.

    1981-01-01

    The natural abundances of the stable isotopes of lead are used to identify natural and industrial sources of lead in the coastal waters of British Columbia, Canada. The 206 Pb/ 207 Pb ratios, used to characterize the lead source, had values of approx. 1.24 for coastal oceanic water, approx. 1.22 for fjord waters receiving lead from mine tailings, and approx. 1.163 for waters near urban centers. The lead concentration data are in agreement with presently accepted seawater values

  4. The separation of stable water-in-oil emulsions

    International Nuclear Information System (INIS)

    Velicogna, D.; Koundakjiian, A.; Beausejour, I.

    1993-01-01

    Stable oil-in-water emulsions are a major problem in the recovery of spilled oils. Such emulsions can contain as little as 10% oil and can have properties very different from the original oils, making their storage and disposal difficult. These problems have led to experiments testing the feasibility of a process for separating these stable emulsions into dischargeable water and reusable oil. The technique investigated involves use of a recyclable solvent to remove the oil and subsequent distillation and/or membrane treatment to recover the oil and recycle the solvent. Results of preliminary tests show that stable water-in-oil emulsions can be separated quite readily with a regenerated solvent system. The only products of these systems are oil, which can be sent to a refinery, and dischargeable water. The recycled solvent can be used many times without any significant decrease in separation efficiency. In order to enhance the throughput of the system, a solvent vapor stripping method was invented. This stripping method also improves the quality of the products and the recycled solvent. Membrane methods can be used as a post-treatment for the produced water in order to achieve more adequate compliance with discharge limits. 4 refs., 3 figs., 5 tabs

  5. Biomass fueled closed cycle gas turbine with water injection

    Energy Technology Data Exchange (ETDEWEB)

    Bardi, Silvia [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    2001-01-01

    Direct water injection has been studied for a small scale ({approx} 8 MW fuel input) closed cycle gas turbine coupled to a biomass fueled CFB furnace. Two different working fluids have been considered (helium-water mixture and nitrogen-water mixture). The water injection could take place between the compressor stages, as an intercooler, or after the high pressure compressor, as an aftercooler. Both this options have been studied, varying the relative humidity levels after the injection and the temperatures of the injected water. The effect of water injection on thermodynamic properties of the working fluids has been studied, together with its effect on turbomachinery isentropic efficiency. A sensitivity analysis on turbomachinery efficiency and cycle base pressure has been included. The results from this study have been compared to the performance of a dry closed cycle without water injection. The wet cycle shows an electric efficiency in the range 29-32% with helium-water mixture as working fluid and 30-32% with nitrogen-water mixture as working fluid, while the total efficiency (referring to the fuel LHV) is always higher than 100%. In the non-injected cycle the electric efficiency is 30-35% with helium and 32-36 with nitrogen. The total efficiency in the dry case with two level intercooling and postcooling is 87-89%, while is higher than 100% when only one stage inter- and postcooling is present. Aside from this, the study also includes a sizing of the heat exchangers for the different cycle variations. The heat transfer area is very sensible to the working fluid and to the amount of injected water and it's always higher when a nitrogen-water mixture is used. Compared to the cycle without water injection, by the way, the number of heat exchangers is reduced. This will lead to a lower pressure drop and a simpler plant layout. The total heat transfer area, however, is higher in the wet cycle than in the dry cycle.

  6. Strategies for stable water splitting via protected photoelectrodes

    DEFF Research Database (Denmark)

    Bae, Dowon; Seger, Brian; Vesborg, Peter Christian Kjærgaard

    2017-01-01

    Photoelectrochemical (PEC) solar-fuel conversion is a promising approach to provide clean and storable fuel (e.g., hydrogen and methanol) directly from sunlight, water and CO2. However, major challenges still have to be overcome before commercialization can be achieved. One of the largest barriers...... photocathodes. In addition, we review protection layer approaches and their stabilities for a wide variety of experimental photoelectrodes for water reduction. Finally, we discuss key aspects which should be addressed in continued work on realizing stable and practical PEC solar water splitting systems....

  7. Precipitation and stream water stable isotope data from the Marys River, Oregon in water year 2015.

    Data.gov (United States)

    U.S. Environmental Protection Agency — Water stable isotope data collected from a range of streams throughout the Marys River basin in water year 2015, and precipitation data collected within the basin at...

  8. Analysis on inflowing of the injecting Water in faulted formation

    Directory of Open Access Journals (Sweden)

    Ji Youjun

    2015-06-01

    Full Text Available As to low permeability reservoir, faults and fractures have a significant impact on effect of water injection and may lead up to the lower efficiency of oil displacement, which will bring about low efficiency of injecting water, and the intended purpose of improving recovery factor by water injection will not be reached. In order to reveal the mechanism for channeling of injecting water, research work is conducted as follows: First of all, based on seepage mechanics, fluid mechanics, rock mass mechanics, and multifield coupling theory, the mathematical model considering fluid–solid coupling of water-flooding development for low permeability reservoir is established, the numerical solution of the coupling model is obtained, and by creating an interface program between the seepage simulation procedure and stress computation program, we set up a feasible method to simulate the process of development of reservoir considering deformation of reservoir stratum; second, some cores are selected to test the stress sensitivity of rock in reservoir, and the relation of permeability and stress is proposed to connect the field parameters of the coupling model; finally, taking the S11 block of Daqing Oilfield, for instance, the seepage field and deformation of reservoir stratum is analyzed, and then the mechanism for leakage of injecting water in this block is given out, and the advice for adjustment of injection–production scheme in the future development stage is provided.

  9. Flow improvers for water injection based on surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Oskarsson, H.; Uneback, I.; Hellsten, M.

    2006-03-15

    In many cases it is desirable to increase the flow of injection water when an oil well deteriorates. It is very costly in offshore operation to lay down an additional water pipe to the injection site. Flow improvers for the injection water will thus be the most cost-effective way to increase the flow rate. During the last years water-soluble polymers have also been applied for this purpose. These drag-reducing polymers are however only slowly biodegraded which has been an incentive for the development of readily biodegradable surfactants as flow improvers for injection water. A combination of a zwitterionic and an anionic surfactant has been tested in a 5.5 inch, 700 m long flow loop containing sulphate brine with salinity similar to sea water. A drag reduction between 75 and 80% was achieved with 119 ppm in solution of the surfactant blend at an average velocity of 1.9 m/s and between 50 and 55% at 2.9 m/s. The surfactants in this formulation were also found to be readily biodegradable in sea water and low bio accumulating which means they have an improved environmental profile compared to the polymers used today. Due to the self-healing properties of the drag-reducing structures formed by surfactants, these may be added before the pump section - contrary to polymers which are permanently destroyed by high shear forces. (Author)

  10. Multi-Phase Modeling of Rainbird Water Injection

    Science.gov (United States)

    Vu, Bruce T.; Moss, Nicholas; Sampson, Zoe

    2014-01-01

    This paper describes the use of a Volume of Fluid (VOF) multiphase model to simulate the water injected from a rainbird nozzle used in the sound suppression system during launch. The simulations help determine the projectile motion for different water flow rates employed at the pad, as it is critical to know if water will splash on the first-stage rocket engine during liftoff.

  11. Stable isotopic composition of East African lake waters

    International Nuclear Information System (INIS)

    Odada, E.O.

    2001-01-01

    The investigation of stable isotopic composition of East African lake waters was conducted by scientists from the Department of Geology, University of Nairobi, as part of the International Decade for the East African Lakes (IDEAL) project and in close collaboration with the scientists from Large Lakes Observatory of the University of Minnesota and the Isotope Hydrology Laboratory of the IAEA in Vienna. The Research Contract was part of the IAEA Co-ordinated Research Programme on Isotope Techniques in Lake Dynamics Investigations, and was sponsored by the Agency. Water and grab sediment samples were obtained from East African Lakes during the month of January and February 1994 and July/August 1995. Water samples were analysed for oxygen and deuterium isotopic composition at the IAEA Laboratories in Vienna, Austria. In this final paper we report the results of the study of oxygen and deuterium isotopic composition from the East African lake waters. (author)

  12. Stable isotopes applied as water tracers for infiltration experiment

    International Nuclear Information System (INIS)

    Liu Xiaoyan; Chen Jiansheng; Sun Xiaoxu; Su Zhiguo

    2011-01-01

    The δD and δ 18 O vertical profiles of soil water were measured prior to and after a rainfall event. Mechanisms of soil water movement were deciphered by comparing the soil water isotope profiles with the isotopic composition of precipitation. The results show that evaporation at the upper depth led to enrichment of the heavy isotopes. Compared to the loess profile, the shallow soil water of sand profile is relatively enriched in D and 18 O due to macro-pore and low water-holding capacity. The precipitation is infiltrated into soil in piston mode, accompanied with significant mixing of older soil water. The preferential fluid flow in loess was observed at depths of 0-20 cm, caused by cracks in the depths. The hydrogen and oxygen isotopic compositions in outflow are close to the precipitation, which shows a mixing of the precipitation and old soil water, and indicates that the isotopic composition of outflow water is mainly controlled by that of the precipitation. The δD and δ 18 O in outflow decreased with time until stable δ values of outflow are close to those of the precipitation. (authors)

  13. Water conservation and allocation guideline for oilfield injection

    International Nuclear Information System (INIS)

    2006-01-01

    This paper was prepared as a guide for regulatory agencies and developers using non-saline water sources in enhanced oil recovery (EOR) schemes. A systems approach was used to achieve specific environmental outcomes that adhered to the Water Conservation and Allocation Policy for Oilfield Injection. The guide was applicable to licence renewal applications for projects operating and licensed to use non-saline water resources, as well as new licence applications for oilfield injection use. The guide provided recommended water conservation practices and application requirements, and outlined regulatory procedures and steps for obtaining a Water Act licence. The guideline was prepared to eliminate the use of non-saline water in EOR projects where feasible alternatives existed, as well as to identify areas with water shortages and reduce the use of non-saline water. The guide included monitoring and reporting requirements to improve the evaluation of water use practices and outlined current initiatives to address water conservation and research. It was concluded that outcomes from the program will include reliable quality water supplies for a sustainable economy, healthy aquatic ecosystems, and safe, secure drinking water supplies for Albertans. 3 tabs., 5 figs

  14. Optimization of post-run corrections for water stable isotope measurements by laser spectroscopy

    Science.gov (United States)

    van Geldern, Robert; Barth, Johannes A. C.

    2013-04-01

    Light stable isotope analyses of hydrogen and oxygen of water are used in numerous aquatic studies from various scientific fields. The advantage of using stable isotope ratios is that water molecules serve as ubiquitous and already present natural tracers. Traditionally, the samples were analyzed in the laboratory by isotope ratio mass spectrometry (IRMS). Within recent years these analyses have been revolutionized by the development of new isotope ratio laser spectroscopy (IRIS) systems that are said to be cheaper, more robust and mobile compared to IRMS. Although easier to operate, laser systems also need thorough calibration with international reference materials and raw data need correction for analytical effects. A major issue in systems that use liquid injection via a vaporizer module is the memory effect, i.e. the carry-over from the previous analyzed sample in a sequence. This study presents an optimized and simple post-run correction procedure for liquid water injection developed for a Picarro water analyzer. The Excel(TM) template will rely exclusively on standard features implemented in MS Office without the need to run macros, additional code written in Visual Basic for Applications (VBA) or to use a database-related software such as MS Access or SQL Server. These protocols will maximize precision, accuracy and sample throughput via an efficient memory correction. The number of injections per unknown sample can be reduced to 4 or less. This procedure meets the demands of faster throughput with reduced costs per analysis. Procedures were verified by an international proficiency test and traditional IRMS techniques. The template is available free for scientific use from the corresponding author or the journals web site (van Geldern and Barth, 2012). References van Geldern, R. and Barth, J.A.C. (2012) Limnol. Oceanogr. Methods 10:1024-1036 [doi: 10.4319/lom.2012.10.1024

  15. Stable water isotopes suggest sub-canopy water recycling in a northern forested catchment

    Science.gov (United States)

    Mark B. Green; Bethany K. Laursen; John L. Campbell; Kevin J. McGuire; Eric P. Kelsey

    2015-01-01

    Stable water isotopes provide a means of tracing many hydrologic processes, including poorly understood dynamics like soil water interactions with the atmosphere. We present a four-year dataset of biweekly water isotope samples from eight fluxes and stores in a headwater catchment at the Hubbard Brook Experimental Forest, New Hampshire, USA. We use Dansgaard's...

  16. Study of the method of water-injected meat identifying based on low-field nuclear magnetic resonance

    Science.gov (United States)

    Xu, Jianmei; Lin, Qing; Yang, Fang; Zheng, Zheng; Ai, Zhujun

    2018-01-01

    The aim of this study to apply low-field nuclear magnetic resonance technique was to study regular variation of the transverse relaxation spectral parameters of water-injected meat with the proportion of water injection. Based on this, the method of one-way ANOVA and discriminant analysis was used to analyse the differences between these parameters in the capacity of distinguishing water-injected proportion, and established a model for identifying water-injected meat. The results show that, except for T 21b, T 22e and T 23b, the other parameters of the T 2 relaxation spectrum changed regularly with the change of water-injected proportion. The ability of different parameters to distinguish water-injected proportion was different. Based on S, P 22 and T 23m as the prediction variable, the Fisher model and the Bayes model were established by discriminant analysis method, qualitative and quantitative classification of water-injected meat can be realized. The rate of correct discrimination of distinguished validation and cross validation were 88%, the model was stable.

  17. The effect of hot water injection on sandstone permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Haugwitz, Christian; Jacobsen, Peter Sally Munch

    2014-01-01

    Seasonal energy storage can be achieved by hot water injection in geothermal sandstone aquifers. We present an analysis of literature data in combination with new short-term flow through permeability experiments in order to address physical and physico-chemical mechanisms that can alter...

  18. Re-injection of produced water: ''Environmental friendliness pays off''

    International Nuclear Information System (INIS)

    Bjerke, E.

    1995-01-01

    The article deals with the re-injection of produced water for minimizing the emission of polluting components and for enhancing the oil recovery on the Norwegian oil field Ula. A closed cycle system is installed increasing the oil production by 4-5.000 bbl per day

  19. Highly efficient 6-stroke engine cycle with water injection

    Science.gov (United States)

    Szybist, James P; Conklin, James C

    2012-10-23

    A six-stroke engine cycle having improved efficiency. Heat is recovered from the engine combustion gases by using a 6-stroke engine cycle in which combustion gases are partially vented proximate the bottom-dead-center position of the fourth stroke cycle, and water is injected proximate the top-dead-center position of the fourth stroke cycle.

  20. Differences in microbial community composition between injection and production water samples of water flooding petroleum reservoirs

    Directory of Open Access Journals (Sweden)

    P. K. Gao

    2015-06-01

    Full Text Available Microbial communities in injected water are expected to have significant influence on those of reservoir strata in long-term water flooding petroleum reservoirs. To investigate the similarities and differences in microbial communities in injected water and reservoir strata, high-throughput sequencing of microbial partial 16S rRNA of the water samples collected from the wellhead and downhole of injection wells, and from production wells in a homogeneous sandstone reservoir and a heterogeneous conglomerate reservoir were performed. The results indicate that a small number of microbial populations are shared between the water samples from the injection and production wells in the sandstone reservoir, whereas a large number of microbial populations are shared in the conglomerate reservoir. The bacterial and archaeal communities in the reservoir strata have high concentrations, which are similar to those in the injected water. However, microbial population abundance exhibited large differences between the water samples from the injection and production wells. The number of shared populations reflects the influence of microbial communities in injected water on those in reservoir strata to some extent, and show strong association with the unique variation of reservoir environments.

  1. Injection and Combustion of RME with Water Emulsions in a Diesel Engine

    Directory of Open Access Journals (Sweden)

    J. Cisek

    2010-01-01

    Full Text Available This paper presents ways of using the fully-digitised triggerable AVL VideoScope 513D video system for analysing the injection and combustion inside a diesel engine cylinder fuelled by RME with water emulsions.The research objects were: standard diesel fuel, rapeseed methyl ester (RME and RME – water emulsions. With the aid of a helical flow reactor, stable emulsions with the water fraction up to 30 % weight were obtained, using an additive to prevent the water from separating out of the emulsion.An investigation was made of the effect of the emulsions on exhaust gas emissions (NOX, CO and HC, particulate matter emissions, smoke and the fuel consumption of a one-cylinder HD diesel engine with direct injection. Additionally, the maximum cylinder pressure rise was calculated from the indicator diagram. The test engine was operated at a constant speed of 1 600 rpm and 4 bar BMEP load conditions. The fuel injection and combustion processes were observed and analysed using endoscopes and a digital camera. The temperature distribution in the combustion chamber was analysed quantitatively using the two-colour method. The injection and combustion phenomena were described and compared.A way to reduce NOX formation in the combustion chamber of diesel engines by adding water in the combustion zone was presented. Evaporating water efficiently lowers the peak flame temperature and the temperature in the post-flame zone. For diesel engines, there is an exponential relationship between NOX emissions and peak combustion temperatures. The energy needed to vaporize the water results in lower peak temperatures of the combusted gases, with a consequent reduction in nitrogen oxide formation. The experimental results show up to 50 % NOX emission reduction with the use of 30% water in an RME emulsion, with unchanged engine performance.

  2. Maintenance and Recovery of Water System for Injection (WFI)

    International Nuclear Information System (INIS)

    Wan Anuar Wan Awang; Ahmad Firdaus Jalil; Wan Mohd Firdaus Wan Ishak

    2015-01-01

    Water system for injection (WFI) is one of the main component in manufacturing pharmaceutical materials and radiopharmaceuticals. This system accredited in 2005. Water quality produced analyzed and give the unsatisfied results. The operation of WFI was stopped temporarily due to technical problems. In 2013, recovery works were implemented with budget of RM 226,500.00. Comprehensive maintenance were implemented by Rykertech (Asia) Sdn. Bhd. With duration of 24 months (October 2014 until September 2016) with cost RM 473,550.00. Now, this system operated in good condition and produced water that meet with the specifications. (author)

  3. Melt quenching and coolability by water injection from below: Co-injection of water and non-condensable gas

    International Nuclear Information System (INIS)

    Cho, Dae H.; Page, Richard J.; Abdulla, Sherif H.; Anderson, Mark H.; Klockow, Helge B.; Corradini, Michael L.

    2006-01-01

    The interaction and mixing of high-temperature melt and water is the important technical issue in the safety assessment of water-cooled reactors to achieve ultimate core coolability. For specific advanced light water reactor (ALWR) designs, deliberate mixing of the core melt and water is being considered as a mitigative measure, to assure ex-vessel core coolability. The goal of our work is to provide the fundamental understanding needed for melt-water interfacial transport phenomena, thus enabling the development of innovative safety technologies for advanced LWRs that will assure ex-vessel core coolability. The work considers the ex-vessel coolability phenomena in two stages. The first stage is the melt quenching process and is being addressed by Argonne National Lab and University of Wisconsin in modified test facilities. Given a quenched melt in the form of solidified debris, the second stage is to characterize the long-term debris cooling process and is being addressed by Korean Maritime University via test and analyses. In this paper, experiments on melt quenching by the injection of water from below are addressed. The test section represented one-dimensional flow-channel simulation of the bottom injection of water into a core melt in the reactor cavity. The melt simulant was molten lead or a lead alloy (Pb-Bi). For the experimental conditions employed (i.e., melt depth and water flow rates), it was found that: (1) the volumetric heat removal rate increased with increasing water mass flow rate and (2) the non-condensable gas mixed with the injected water had no impairing effect on the overall heat removal rate. Implications of these current experimental findings for ALWR ex-vessel coolability are discussed

  4. Water vapor stable isotope observations from tropical Australia

    KAUST Repository

    Parkes, Stephen

    2015-04-01

    The response of the tropical hydrological cycle to anthropogenically induced changes in radiative forcing is one of the largest discrepancies between climate models. Paleoclimate archives of the stable isotopic composition of precipitation in the tropics indicate a relationship with precipitation amount that could be exploited to study past hydroclimate and improve our knowledge of how this region responds to changes in climate forcing. Recently modelling studies of convective parameterizations fitted with water isotopes and remote sensing of water vapor isotopes in the tropics have illustrated uncertainty in the assumed relationship with rainfall amount. Therefore there is a need to collect water isotope data in the tropics that can be used to evaluate these models and help identify the relationships between the isotopic composition of meteoric waters and rainfall intensity. However, data in this region is almost non-existent. Here we present in-situ water vapor isotopic measurements and the HDO retrievals from the co-located Total Column Carbon Observing Network (TCCON) site at Darwin in Tropical Australia. The Darwin site is interestingly placed within the tropical western pacific region and is impacted upon by a clear monsoonal climate, and key climate cycles including ENSO and Madden Julian Oscillations. The analysis of the data illustrated relationships between water vapor isotopes and humidity which demonstrated the role of precipitation processes in the wet season and air mass mixing during the dry season. Further the wet season observations show complex relationships between humidity and isotopes. A simple Rayleigh distillation model was not obeyed, instead the importance of rainfall re-evaporation in generating the highly depleted signatures was demonstrated. These data potentially provide a useful tool for evaluating model parameterizations in monsoonal regions as they demonstrate relationships with precipitation processes that cannot be observed with

  5. An emergency water injection system (EWIS) for future CANDU reactors

    International Nuclear Information System (INIS)

    Marques, Andre L.F.; Todreas, Neil E.; Driscoll, Michael J.

    2000-01-01

    This paper deals with the investigation of the feasibility and effectiveness of water injection into the annulus between the calandria tubes and the pressure tubes of CANDU reactors. The purpose is to provide an efficient decay heat removal process that avoids permanent deformation of pressure tubes severe accident conditions, such as loss of coolant accident (LOCA). The water injection may present the benefit of cost reduction and better actuation of other related safety systems. The experimental work was conducted at the Massachusetts Institute of Technology (MIT), in a setup that simulated, as close as possible, a CANDU bundle annular configuration, with heat fluxes on the order of 90 kW/m 2 : the inner cylinder simulates the pressure tube and the outer tube represents the calandria tube. The experimental matrix had three dimensions: power level, annulus water level and boundary conditions. The results achieved overall heat transfer coefficients (U), which are comparable to those required (for nominal accident progression) to avoid pressure tube permanent deformation, considering current CANDU reactor data. Nonetheless, future work should be carried out to investigate the fluid dynamics such as blowdown behavior, in the peak bundle, and the system lay-out inside the containment to provide fast water injection. (author)

  6. The research of new type stratified water injection process intelligent measurement technology

    Science.gov (United States)

    Zhao, Xin

    2017-10-01

    To meet the needs of injection and development of Daqing Oilfield, the injection of oil from the early stage of general water injection to the subdivision of water is the purpose of improving the utilization degree and the qualified rate of water injection, improving the performance of water injection column and the matching process. Sets of suitable for high water content of the effective water injection technology supporting technology. New layered water injection technology intelligent measurement technology will be more information testing and flow control combined into a unified whole, long-term automatic monitoring of the work of the various sections, in the custom The process has the characteristics of "multi-layer synchronous measurement, continuous monitoring of process parameters, centralized admission data", which can meet the requirement of subdivision water injection, but also realize the automatic synchronization measurement of each interval, greatly improve the efficiency of tiered injection wells to provide a new means for the remaining oil potential.

  7. Economics of water injected air screw compressor systems

    OpenAIRE

    Madhav, K. V.; Kovacevic, A.

    2015-01-01

    There is a growing need for compressed air free of entrained oil to be used in industry. In many cases it can be supplied by oil flooded screw compressors with multi stage filtration systems, or by oil free screw compressors. However, if water injected screw compressors can be made to operate reliably, they could be more efficient and therefore cheaper to operate. Unfortunately, to date, such machines have proved to be insufficiently reliable and not cost effective. This paper describes an in...

  8. Analysis of effect of late water injection on RCS repressurization

    International Nuclear Information System (INIS)

    Tao Jun; Cao Xuewu

    2011-01-01

    Effect of late water injection on RCS repressurization during high pressure severe accident sequence in a typical PWR was analyzed. As the results shown, late water injection could increase RCS pressure when RPV failed without RCS passive depressurization. Especially in the condition of opening one PORV, RCS pressure could reach high pressure limit when RPV failed and the risk of HPME and DCH was dramatically increased. Integrity of containment could be threatened. However, in the condition of RCS passive depressurization induced by pressurizer surge line creep failure, RCS pressure could be decreased to very low level even only one PORV was opened and two trains of emergency core cooling were implemented. The risk of HPME and DCH was eliminated. The more PORVs were opened, the faster accident progression was and the earlier RPV failed. RCS pressure was a little higher when PRV failed if two trains of emergency core cooling was implemented comparing with the condition with only one train of emergency core cooling. However the time of RPV failure was obviously delayed. From the point of delaying RPV failure and preventing containment early failure of view, the optimized late water injection was opening three PORVs and implementing two trains of emergency core cooling. (authors)

  9. Measuring and Modeling the Displacement of Connate Water in Chalk Core Plugs during Water Injection

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C; Aage, Helle Karina; Andersen, Bertel Lohmann

    2006-01-01

    and forms a mixed water bank with almost 100% connate water in the front behind which a gradual transition to pure injection water occurs. This result underpins log interpretations from waterflooded chalk reservoirs. An ad hoc model was set up by use of the results, and the process was examined...

  10. Assessment of water sources to plant growth in rice based cropping systems by stable water isotopes

    Science.gov (United States)

    Mahindawansha, Amani; Kraft, Philipp; Racela, Heathcliff; Breuer, Lutz

    2016-04-01

    Rice is one of the most water-consuming crops in the world. Understanding water source utilization of rice will help us to improve water use efficiency (WUE) in paddy management. The objectives of our study are to evaluate the isotopic compositions of surface ponded water, soil water, irrigation water, groundwater, rain water and plant water and based on stable water isotope signatures to evaluate the contributions of various water sources to plant growth (wet rice, aerobic rice and maize) together with investigating the contribution of water from different soil horizons for plant growth in different maturity periods during wet and dry seasons. Finally we will compare the water balances and crop yields in both crops during both seasons and calculate the water use efficiencies. This will help to identify the most efficient water management systems in rice based cropping ecosystems using stable water isotopes. Soil samples are collected from 9 different depths at up to 60 cm in vegetative, reproductive and matured periods of plant growth together with stem samples. Soil and plant samples are extracted by cryogenic vacuum extraction. Root samples are collected up to 60 cm depth from 10 cm intercepts leading calculation of root length density and dry weight. Groundwater, surface water, rain water and irrigation water are sampled weekly. All water samples are analyzed for hydrogen and oxygen isotope ratios (d18O and dD) using Los Gatos Research DLT100. Rainfall records, ground water level, surface water level fluctuations and the amount of water irrigated in each field will be measured during the sampling period. The direct inference approach which is based on comparing isotopic compositions (dD and d18O) between plant stem water and soil water will be used to determine water sources taken up by plant. Multiple-source mass balance assessment can provide the estimated range of potential contributions of water from each soil depth to root water uptake of a crop. These

  11. Water Injection on Commercial Aircraft to Reduce Airport Nitrogen Oxides

    Science.gov (United States)

    Daggett, David L.; Hendricks, Robert C.; Fucke, Lars; Eames, David J. H.

    2010-01-01

    The potential nitrogen oxide (NO(x) reductions, cost savings, and performance enhancements identified in these initial studies of waterinjection technology strongly suggest that it be further pursued. The potential for engine maintenance cost savings from this system should make it very attractive to airline operators and assure its implementation. Further system tradeoff studies and engine tests are needed to answer the optimal system design question. Namely, would a low-risk combustor injection system with 70- to 90-percent NO(x) reduction be preferable, or would a low-pressure compressor (LPC) misting system with only 50-percent NO(x) reduction but larger turbine inlet temperature reductions be preferable? The low-pressure compressor injection design and operability issues identified in the report need to be addressed because they might prevent implementation of the LPC type of water-misting system. If water-injection technology challenges are overcome, any of the systems studied would offer dramatic engine NO(x) reductions at the airport. Coupling this technology with future emissions-reduction technologies, such as fuel-cell auxiliary power units will allow the aviation sector to address the serious challenges of environmental stewardship, and NO(x) emissions will no longer be an issue at airports.

  12. Alternative water injection device to reactor equipment facility

    International Nuclear Information System (INIS)

    Yamashita, Masahiro.

    1995-01-01

    The device of the present invention injects water to the reactor and the reactor container continuously for a long period of time for preventing occurrence of a severe accident in a BWR type reactor and maintaining the integrity of the reactor container even if the accident should occur. Namely, diesel-driven pumps disposed near heat exchangers of a reactor after-heat removing system (RHR) are operated before the reactor is damaged by the after heat to cause reactor melting. A sucking valve disposed to a pump sucking pipeline connecting a secondary pipeline of the RHR heat exchanger and the diesel driving pump is opened. A discharge valve disposed to a pump discharge pipeline connecting a primary pipeline of the RHR heat exchanger and the diesel driving pump is opened. With such procedures, sea water is introduced from a sea water taking port through the top end of the secondary pipeline of the RHR heat exchanger and water is injected into the inside of the pressure vessel or the reactor container by way of the primary pipeline of the RHR heat exchanger. As a result, the reactor core is prevented from melting even upon occurrence of a severe accident. (I.S.)

  13. Ground-Water Nutrient Flux to Coastal Waters and Numerical Simulation of Wastewater Injection at Kihei, Maui, Hawaii

    Science.gov (United States)

    Hunt, Charles D.

    2007-01-01

    more conservative estimate of injection flux approaching the shore: 27 and 1.5 kg/d-km nitrogen and phosphorus, roughly one-half and one-ninth the injection-source estimates, and 3.5 and 3.4 times background flux. Effluent has 8 O and 2 H stable-isotope signatures that are distinct from local ground water, as well as 15 N and 11 B signatures diagnostic of domestic waste and laundry detergents, respectively. Pharmaceuticals and organic wastewater compounds also were present in effluent and the downgradient well. These isotopes and chemicals served as wastewater tracers in Kihei ground water and may be useful tracers in nearshore marine waters and aquifers elsewhere in Hawaii.

  14. Stable, tunable, quasimonoenergetic electron beams produced in a laser wakefield near the threshold for self-injection

    Directory of Open Access Journals (Sweden)

    S. Banerjee

    2013-03-01

    Full Text Available Stable operation of a laser-plasma accelerator near the threshold for electron self-injection in the blowout regime has been demonstrated with 25–60 TW, 30 fs laser pulses focused into a 3–4 millimeter length gas jet. Nearly Gaussian shape and high nanosecond contrast of the focused pulse appear to be critically important for controllable, tunable generation of 250–430 MeV electron bunches with a low-energy spread, ∼10  pC charge, a few-mrad divergence and pointing stability, and a vanishingly small low-energy background. The physical nature of the near-threshold behavior is examined using three-dimensional particle-in-cell simulations. Simulations indicate that properly locating the nonlinear focus of the laser pulse within the plasma suppresses continuous injection, thus reducing the low-energy tail of the electron beam.

  15. Cold water injection into two-phase mixtures

    International Nuclear Information System (INIS)

    1989-07-01

    This report presents the results of a review of the international literature regarding the dynamic loadings associated with the injection of cold water into two-phase mixtures. The review placed emphasis on waterhammer in nuclear power plants. Waterhammmer incidence data were reviewed for information related to thermalhydraulic conditions, underlying causes and consequential damage. Condensation induced waterhammer was found to be the most significant consequence of injecting cold water into a two-phase system. Several severe waterhammer incidents have been attributed to slug formation and steam bubble collapse under conditions of stratified steam and cold water flows. These phenomena are complex and not well understood. The current body of experimental and analytical knowledge is not large enough to establish maps of expected regimes of condensation induced waterhammer. The Electric Power Research Institute, in the United States, has undertaken a major research and development programme to develop the knowledge base for this area. The limited models and data currently available show that mechanical parameters are as important as thermodynamic conditions for the initiation of condensation induced waterhammer. Examples of bounds for avoiding two-phase waterhammer are given. These bounds are system specific and depend upon parameters such as pump capacity, pipe length and pipe orientation

  16. Phenol Contaminated Water Treatment on Several Modified Dimensionally Stable Anodes.

    Science.gov (United States)

    Jayathilaka, Pavithra Bhakthi; Hapuhinna, Kushani Umanga Kumari; Bandara, Athula; Nanayakkara, Nadeeshani; Subasinghe, Nalaka Deepal

    2017-08-01

      Phenolic compounds are some of the most common hazardous organics in wastewater. Removal of these pollutants is important. Physiochemical method such as electrochemical oxidation on dimensionally stable anodes is more convenient in removing such organic pollutants. Therefore, this study focuses on development of three different anodes for phenol contaminated water treatment. The performances of steel/IrO2, steel/IrO2-Sb2O3, and Ti/IrO2-Sb2O3 anodes were tested and compared. Nearly 50, 76, and 84% of chemical oxygen demand removal efficiencies were observed for steel/IrO2, steel/IrO2-Sb2O3, and Ti/IrO2-Sb2O3 anodes, respectively. The formation of intermediates was monitored for three anodes and the Ti/IrO2-Sb2O3 anode showed the most promising results. Findings suggest that the developed anode materials can enhance phenol oxidation efficiency and that mixed metal oxide layer has major influence on the anode. Among the selected metal oxide mixtures IrO2-Sb2O3 was the most suitable under given experimental conditions.

  17. Aging study of boiling water reactor high pressure injection systems

    International Nuclear Information System (INIS)

    Conley, D.A.; Edson, J.L.; Fineman, C.F.

    1995-03-01

    The purpose of high pressure injection systems is to maintain an adequate coolant level in reactor pressure vessels, so that the fuel cladding temperature does not exceed 1,200 degrees C (2,200 degrees F), and to permit plant shutdown during a variety of design basis loss-of-coolant accidents. This report presents the results of a study on aging performed for high pressure injection systems of boiling water reactor plants in the United States. The purpose of the study was to identify and evaluate the effects of aging and the effectiveness of testing and maintenance in detecting and mitigating aging degradation. Guidelines from the United States Nuclear Regulatory Commission's Nuclear Plant Aging Research Program were used in performing the aging study. Review and analysis of the failures reported in databases such as Nuclear Power Experience, Licensee Event Reports, and the Nuclear Plant Reliability Data System, along with plant-specific maintenance records databases, are included in this report to provide the information required to identify aging stressors, failure modes, and failure causes. Several probabilistic risk assessments were reviewed to identify risk-significant components in high pressure injection systems. Testing, maintenance, specific safety issues, and codes and standards are also discussed

  18. Cytocompatible and water stable ultrafine protein fibers for tissue engineering

    Science.gov (United States)

    Jiang, Qiuran

    This dissertation proposal focuses on the development of cytocompatible and water stable protein ultrafine fibers for tissue engineering. The protein-based ultrafine fibers have the potential to be used for biomedicine, due to their biocompatibility, biodegradability, similarity to natural extracellular matrix (ECM) in physical structure and chemical composition, and superior adsorption properties due to their high surface to volume ratio. However, the current technologies to produce the protein-based ultrafine fibers for biomedical applications still have several problems. For instance, the current electrospinning and phase separation technologies generate scaffolds composed of densely compacted ultrafine fibers, and cells can spread just on the surface of the fiber bulk, and hardly penetrate into the inner sections of scaffolds. Thus, these scaffolds can merely emulate the ECM as a two dimensional basement membrane, but are difficult to mimic the three dimensional ECM stroma. Moreover, the protein-based ultrafine fibers do not possess sufficient water stability and strength for biomedical applications, and need modifications such as crosslinking. However, current crosslinking methods are either high in toxicity or low in crosslinking efficiency. To solve the problems mentioned above, zein, collagen, and gelatin were selected as the raw materials to represent plant proteins, animal proteins, and denatured proteins in this dissertation. A benign solvent system was developed specifically for the fabrication of collagen ultrafine fibers. In addition, the gelatin scaffolds with a loose fibrous structure, high cell-accessibility and cell viability were produced by a novel ultralow concentration phase separation method aiming to simulate the structure of three dimensional (3D) ECM stroma. Non-toxic crosslinking methods using citric acid as the crosslinker were also developed for electrospun or phase separated scaffolds from these three proteins, and proved to be

  19. Methodology for surge pressure evaluation in a water injection system

    Energy Technology Data Exchange (ETDEWEB)

    Meliande, Patricia; Nascimento, Elson A. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Civil; Mascarenhas, Flavio C.B. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Lab. de Hidraulica Computacional; Dandoulakis, Joao P. [SHELL of Brazil, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    Predicting transient effects, known as surge pressures, is of high importance for offshore industry. It involves detailed computer modeling that attempts to simulate the complex interaction between flow line and fluid in order to ensure efficient system integrity. Platform process operators normally raise concerns whether the water injection system is adequately designed or not to be protected against possible surge pressures during sudden valve closure. This report aims to evaluate the surge pressures in Bijupira and Salema water injection systems due to valve closure, through a computer model simulation. Comparisons among the results from empirical formulations are discussed and supplementary analysis for Salema system were performed in order to define the maximum volumetric flow rate for which the design pressure was able to withstand. Maximum surge pressure values of 287.76 bar and 318.58 bar, obtained in Salema and Bijupira respectively, using empirical formulations have surpassed the operating pressure design, while the computer model results have pointed the greatest surge pressure value of 282 bar in Salema system. (author)

  20. Reassessing the stable water isotope record in understanding past climate

    International Nuclear Information System (INIS)

    Noone, D.; Simmonds, I.

    1999-01-01

    Full text: The impact of atmospheric circulation on the stable water isotope record has been examined using an atmospheric general circulation model to reassess the validity of using isotopes to reconstruct Earth's climate history. Global temperature changes are classically estimated from the variations in (polar) isotopic values assuming a simple linear relationship. Such a relationship can be justified from first order theoretical considerations given that the isotopic fractionation at the deposition (ice core) site is temperature dependent. However, it is found that the history of a given air mass is more important that local processes because of the net effect of condensation events active along the transport pathway from the source region. Modulations in the hemispheric flow are seen to be crucial to Antarctic precipitation and the isotopic signal. Similarly, both transient and stationary disturbances influence the pathways of the air masses associated with Antarctic precipitation. During different climate regimes, such as that of the Last Glacial Maximum, the properties of these types of disturbances may not be assumed to be the same. As such, we may not assume that the condensation histories are the same as under different climate conditions. Therefore, the veracity of the linear climate reconstructions becomes questionable. Notwithstanding this result, the types of changes to the circulation regime that are expected generally correspond to changes in the global temperature. This fortunate result does not disallow the use of regressional reconstruction, however, the uncertainties associated with these circulation changes are of the same magnitude as the differences suggested by conventional linear regression in climate reconstruction. This indicates that interpretation of ice core data must be accompanied by detailed examination of the atmospheric processes and quantification of the impacts of their changes. Copyright (1999) Geological Society of Australia

  1. A bremsstrahlung gamma-ray source based on stable ionization injection of electrons into a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Döpp, A., E-mail: andreas.doepp@polytechnique.edu [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France); Centro de Laseres Pulsados, Parque Cientfico, 37185 Villamayor, Salamanca (Spain); Guillaume, E.; Thaury, C.; Lifschitz, A. [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France); Sylla, F. [SourceLAB SAS, 86 rue de Paris, 91400 Orsay (France); Goddet, J-P.; Tafzi, A.; Iaquanello, G.; Lefrou, T.; Rousseau, P. [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France); Conejero, E.; Ruiz, C. [Departamento de Física Aplicada, Universidad de Salamanca, Plaza de laMerced s/n, 37008 Salamanca (Spain); Ta Phuoc, K.; Malka, V. [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France)

    2016-09-11

    Laser wakefield acceleration permits the generation of ultra-short, high-brightness relativistic electron beams on a millimeter scale. While those features are of interest for many applications, the source remains constraint by the poor stability of the electron injection process. Here we present results on injection and acceleration of electrons in pure nitrogen and argon. We observe stable, continuous ionization-induced injection of electrons into the wakefield for laser powers exceeding a threshold of 7 TW. The beam charge scales approximately with the laser energy and is limited by beam loading. For 40 TW laser pulses we measure a maximum charge of almost 1 nC per shot, originating mostly from electrons of less than 10 MeV energy. The relatively low energy, the high charge and its stability make this source well-suited for applications such as non-destructive testing. Hence, we demonstrate the production of energetic radiation via bremsstrahlung conversion at 1 Hz repetition rate. In accordance with GEANT4 Monte-Carlo simulations, we measure a γ-ray source size of less than 100 μm for a 0.5 mm tantalum converter placed at 2 mm from the accelerator exit. Furthermore we present radiographs of image quality indicators.

  2. Evaluation of Water Injection Effect on NO(x) Formation for a Staged Gas Turbine Combustor

    Science.gov (United States)

    Fan, L.; Yang, S. L.; Kundu, K. P.

    1996-01-01

    NO(x) emission control by water injection on a staged turbine combustor (STC) was modeled using the KIVA-2 code with modification. Water is injected into the rich-burn combustion zone of the combustor by a single nozzle. Parametric study for different water injection patterns was performed. Results show NO(x) emission will decrease after water being injected. Water nozzle location also has significant effect for NO formation and fuel ignition. The chemical kinetic model is also sensitive to the excess water. Through this study, a better understanding of the physics and chemical kinetics is obtained, this will enhance the STC design process.

  3. Stable-isotope composition of the water of apple juice

    International Nuclear Information System (INIS)

    Bricout, Jacques; Merlivat, Liliane

    1973-01-01

    By deuterium and oxygen 18 analysis, it was shown that apples' water is enriched in heavier isotopes as compared to rain water. The isotopic composition of the water of reconstituted apple juice is closed to the isotopic content of the rain water used for dilution. Thus, deuterium and oxyden 18 analysis allows a good analytical distinction between natural apple juice and reconstituted juices [fr

  4. The effect of low capacity injection systems on transient initiated loss of vessel water injection at Browns Ferry unit one

    International Nuclear Information System (INIS)

    Ott, L.T.

    1983-01-01

    Probabilistic risk assessment (PRA) analyses have indicated the transient initiated loss of vessel water injection (TQUV sequence) to be a dominant accident scenario for BWR plants. The PRA studies assumed the low capacity injection systems to be unimportant in severe accidents. The results of a Severe Accident Sequence Analysis (SASA) Program study have shown that these systems are capable of preventing or significantly delaying core damage in a TQUV sequence

  5. Combined stable isotope trajectories for water-rock interaction

    International Nuclear Information System (INIS)

    Blattner, P.; Department of Scientific and Industrial Research, Lower Hutt

    1981-01-01

    The 'mixed' model of water-rock interaction (1980 Workshop) is explained in detail. Based on the magnitude of the oxygen isotope shifts of their recharge water, different geothermal systems can be placed in an evolutionary series, from incipient (large shift of water) to mature (small shift of water). Isotopes of different chemical elements may be combined, to yield a stringent test of whether or not a given change in rock composition may be ascribed to interaction with water (L-shaped trajectories). For the acidic eruptives of the Taupo Volcanic Zone, available strontium and oxygen isotope data practically rule out an origin by partial melting of greywacke basement

  6. Water stable isotopes: application to the water cycle and climate variations study

    International Nuclear Information System (INIS)

    Risi, C.

    2009-12-01

    The stable isotopic composition of water (H 2 16 , HDO, H 2 18 , H 2 17 ) is a promising tracer of the present day water cycle and past climates. While the isotopic composition recorded in polar ice core have long been used to reconstruct past temperatures, however, what controls the isotopic composition of the tropical precipitation is more complex. The goal of this thesis is thus to better understand the processes that affect the isotopic composition of tropical precipitation and atmospheric water, more particularly in the tropics. Since most of the tropical precipitation arises from atmospheric convection, and most isotopic archives are on land, we focus more particularly on the impact of convective and land surface processes. In turn, what can be learned about convection and land surface processes using isotopic measurements? Can they help constrain their representation in models? At the inter-annual to climate change scale, what information about the tropical climate variability is recorded in isotopic signals observed in archives? First, we investigate the influence of convection on water stable isotopes. We use both (1) numerical modeling, with a hierarchy of models (single column model, two-dimensional model of squall lines, general circulation model) and (2) data analysis, using isotopic data from rain collected in the Sahel during the African Monsoon Multidisciplinary Analysis campaign, at the event and intra-event scales. These studies highlight the strong impact of convection on the precipitation composition, and stress the importance of rain evaporation and convective or meso-scale subsidence in controlling the rain isotopic composition. Convection also plays an important role on isotopic profiles in the upper troposphere-lower stratosphere. Second, we study what information about climatic variability is recorded by water stable isotopes in precipitation. We analyze simulations of present day and past climates with LMDZ, and evaluate to what extent

  7. Water stable isotope measurements of Antarctic samples by means of IRMS and WS-CRDS techniques

    Science.gov (United States)

    Michelini, Marzia; Bonazza, Mattia; Braida, Martina; Flora, Onelio; Dreossi, Giuliano; Stenni, Barbara

    2010-05-01

    In the last years in the scientific community there has been an increasing interest for the application of stable isotope techniques to several environmental problems such as drinking water safeguarding, groundwater management, climate change, soils and paleoclimate studies etc. For example, the water stable isotopes, being natural tracers of the hydrological cycle, have been extensively used as tools to characterize regional aquifers and to reconstruct past temperature changes from polar ice cores. Here the need for improvements in analytical techniques: the high request for information calls for technologies that can offer a great quantity of analyses in short times and with low costs. Furthermore, sometimes it is difficult to obtain big amount of samples (as is the case for Antarctic ice cores or interstitial water) preventing the possibility to replicate the analyses. Here, we present oxygen and hydrogen measurements performed on water samples covering a big range of isotopic values (from very negative antarctic precipitation to mid-latitude precipitation values) carried out with both the conventional Isotope Ratio Mass Spectrometry (IRMS) technique and with a new method based on laser absorption techniques, the Wavelenght Scanned Cavity Ringdown Spectroscopy (WS-CRDS). This study is focusing on improving the precision of the measurements carried out with WS-CRDS in order to extensively apply this method to Antarctic ice core paleoclimate studies. The WS-CRDS is a variation of the CRDS developed in 1988 by O'Keef and Deacon. In CRDS a pulse of light goes through a box with high reflective inner surfaces; when there is no sample in the box the light beam doesn't find any obstacle in its path, but the reflectivity of the walls is not perfect so eventually there will be an absorption of the light beam; when the sample is injected in the box there is absorption and the difference between the time of absorption without and with sample is proportional to the quantity

  8. Stable isotope study of thermal and other waters in Fiji

    International Nuclear Information System (INIS)

    Cox, M.E.; Hulston, J.R.

    1980-01-01

    The O-18/O-16, D/H ratios and chloride concentrations of 79 thermal spring, subsurface, and surface waters from the two main islands of Fiji have been measured to determine the origin of the thermal waters and the characteristics of the geothermal activity. The meteoric waters generally fall along the Meteoric Water Line with a slope of 8, and best fit a line of this slope with a delta D intercept of +13 per mill. The delta O-18/delta D ratios of the thermal waters indicate low magnitude subsurface temperatures and a negligible enrichment in O-18. In one coastal locality in which higher temperature conditions exist, up to 50% seawater is shown to be mixing within the system, probably at shallow depths. The isotopic characteristics of the thermal waters reflect those of the local meteoric water, indicating localised recharge and an essentially meteoric origin. The effects of prevailing wind conditions and topography of these islands cause a depletion of deuterium in both precipitation and surface meteoric water from windward to leeward coasts (auth)

  9. Stable solid state reference electrodes for high temperature water chemistry

    International Nuclear Information System (INIS)

    Jayaweera, P.; Millett, P.J.

    1995-01-01

    A solid state electrode capable of providing a stable reference potential under a wide range of temperatures and chemical conditions has been demonstrated. The electrode consists of a zirconia or yttria-stabilized zirconia tube packed with an inorganic polymer electrolyte and a silver/silver chloride sensing element. The sensing element is maintained near room temperature by a passive cooling heat sink. The electrode stability was demonstrated by testing it in high temperature (280 C) aqueous solutions over extended periods of time. This reference electrode is useful in many applications, particularly for monitoring the chemistry in nuclear and fossil power plants

  10. Stable isotope content of South African river water

    International Nuclear Information System (INIS)

    Talma, A.S.

    1987-01-01

    Variations of the isotopic ratios 18 O/ 16 O and D/H in natural waters reflect the variety of processes to which the water was subjected within the hydrological cycle. Time series of the 18 O content of the major South African rivers over a few years have been obtained in order to characterise the main features of these variations in both time and space. Regionally the average '1 8 O content of river water reflects that of the prevailing rains within the catchment. 18 O variations with time are mainly correlated with river flow rates. Impoundments upstream and management of river flows reduce this correlation. Isotope variations along the course of a river show the effects of inflow from smaller streams and evaporation in the river or its impoundments. These observations indicate the use of isotopic methods to study the evaporation and mixing of river water and its interaction with the surrounding environment

  11. A method to extract soil water for stable isotope analysis

    Science.gov (United States)

    Revesz, Kinga; Woods, Peter H.

    1990-07-01

    A method has been developed to extract soil water for determination of deuterium (D) and 18O content. The principle of this method is based on the observation that water and toluene form an azeotropic mixture at 84.1°C, but are completely immiscible at ambient temperature. In a specially designed distillation apparatus, the soil water is distilled at 84.1°C with toluene and is separated quantitatively in the collecting funnel at ambient temperature. Traces of toluene are removed and the sample can be analyzed by mass spectrometry. Kerosene may be substituted for toluene. The accuracy of this technique is ± 2 and ± 0.2‰, respectively, for δD and δ 18O. Reduced accuracy is obtained at low water contents.

  12. UV disinfection of injection and drinking water - an accepted method on offshore oil platforms

    International Nuclear Information System (INIS)

    Brunner, H.; Klein, H.P.

    1985-01-01

    Ultraviolet disinfection packages have been developed for the treatment of drinking water and injection water on offshore oil platforms. Large-scale tests with sulphate reducing bacteria out outlined. (Auth.)

  13. Water enriched in the rare stable isotopes : Preparation, measurement and applications

    NARCIS (Netherlands)

    Faghihi, Vahideh

    2016-01-01

    The subject of this thesis is water with increased abundances of the rare stable isotopes 2H and 18O (and to some extent also 17O). Such artificially enriched (or "labelled") waters are often used in biomedicine, for establishing the total amount of body water (and thus body composition) of humans

  14. Ground cover influence on evaporation and stable water isotopes in soil water

    Science.gov (United States)

    Magdalena Warter, Maria; Jiménez-Rodríguez, Cesar D.; Coenders-Gerrits, Miriam; Teuling, Adriaan J. Ryan

    2017-04-01

    Forest ecosystems are characterized by complex structures which influence hydrological processes such as evaporation. The vertical stratification of the forest modifies the effect of the evaporation process due to the composition and local distribution of species within the forest. The evaluation of it will improve the understanding of evaporation in forest ecosystems. To determine the influence of forest understory on the fractionation front, four ground cover types were selected from the Speulderbos forest in the Netherlands. The native species of Thamariskmoss (Thuidium thamariscinum), Rough Stalked Feathermoss (Brachythecium rutabulum), and Haircapmoss (Polytrichum commune) as well as one type of litter made up of Douglas-Fir needles (Pseudotsuga menziesii) were used to analyse the rate of evaporation and changes on the isotopic concentration of the soil water on an in-situ basis in a controlled environment. Over a period of 4 weeks soil water content and atmospheric conditions were continuously measured, while the rainfall simulations were performed with different amounts and timings. The reference water added to the boxes keeps a stable composition along the trial period with a δ ^2H value of -42.59±1.15 \\permil} and δ 18O of -6.01±0.21 \\permil}. The evaporation front in the four ground covers is located between 5 and 10 cm depth and deuterium excess values are bigger than 5 \\permil. The litter layer of Douglas-Fir needles is the cover with higher fractionation in respect to the added water at 10 cm depth (δ ^2H: -29.79 \\permil), while the Haircapmoss keeps the lower fractionation rate at 5 cm and 10 cm (δ ^2H: -33.62 and δ ^2H: -35.34 \\permil). The differences showed by the soil water beneath the different ground covers depict the influence of ground cover on fractionation rates of the soil water, underlining the importance of the spatial heterogeneity of the evaporation front in the first 15 cm of soil.

  15. Using water stable isotopes to assess evaporation and water residence time of lakes in EPA’s National Lakes Assessment.

    Science.gov (United States)

    Stable isotopes of water (18O and 2H) can be very useful in large-scale monitoring programs because water samples are easy to collect and water isotopes integrate information about basic hydrological processes such as evaporation as a percentage of inflow (E/I), w...

  16. Toward a simple, repeatable, non-destructive approach to measuring stable-isotope ratios of water within tree stems

    Science.gov (United States)

    Raulerson, S.; Volkmann, T.; Pangle, L. A.

    2017-12-01

    Traditional methodologies for measuring ratios of stable isotopes within the xylem water of trees involve destructive coring of the stem. A recent approach involves permanently installed probes within the stem, and an on-site assembly of pumps, switching valves, gas lines, and climate-controlled structure for field deployment of a laser spectrometer. The former method limits the possible temporal resolution of sampling, and sample size, while the latter may not be feasible for many research groups. We present results from initial laboratory efforts towards developing a non-destructive, temporally-resolved technique for measuring stable isotope ratios within the xylem flow of trees. Researchers have used direct liquid-vapor equilibration as a method to measure isotope ratios of the water in soil pores. Typically, this is done by placing soil samples in a fixed container, and allowing the liquid water within the soil to come into isotopic equilibrium with the headspace of the container. Water can also be removed via cryogenic distillation or azeotropic distillation, with the resulting liquid tested for isotope ratios. Alternatively, the isotope ratios of the water vapor can be directly measured using a laser-based water vapor isotope analyzer. Well-established fractionation factors and the isotope ratios in the vapor phase are then used to calculate the isotope ratios in the liquid phase. We propose a setup which would install a single, removable chamber onto a tree, where vapor samples could non-destructively and repeatedly be taken. These vapor samples will be injected into a laser-based isotope analyzer by a recirculating gas conveyance system. A major part of what is presented here is in the procedure of taking vapor samples at 100% relative humidity, appropriately diluting them with completely dry N2 calibration gas, and injecting them into the gas conveyance system without inducing fractionation in the process. This methodology will be helpful in making

  17. Pilot test of pressure maintenance by water injection and gas injection in the M'Bega field

    Energy Technology Data Exchange (ETDEWEB)

    Hodee, B

    1965-02-01

    The M'Bega reservoir, Gabon, is one that is both fractured and fissured, and its reservoir rock, improperly referred to as silicified clay, is made up of opal-cement silt. At the time it began production, the major unknown factor in this field was the amount of oil it contained. The factor was finally determined after 18 mo. of production, once data was obtained concerning the advance of aquifiers. Up until that time, applied comparisons of successive data could not differentiate between the activity of aquifers and that of dissolved gas expansion with partial segregation. Consequently, a pilot test was made in which pressure was maintained by water injection. Then, with a double drainage phenomena (the tops by the gas, and the flanks by the aquifer water), production of the field consisted of bringing about a coincidence between the water and gas fronts at the level of the existing wells by means of gas injection.

  18. Method of injecting cooling water in emergency core cooling system (ECCS) of PWR type reactor

    International Nuclear Information System (INIS)

    Sobajima, Makoto; Adachi, Michihiro; Tasaka, Kanji; Suzuki, Mitsuhiro.

    1979-01-01

    Purpose: To provide a cooling water injection method in an ECCS, which can perform effective cooling of the reactor core. Method: In a method of injecting cooling water in an ECCS as a countermeasure against a rupture accident of a pwr type reactor, cooling water in the first pressure storage injection system is injected into the upper plenum of the reactor pressure vessel at a set pressure of from 50 to 90 atg. and a set temperature of from 80 to 200 0 C, cooling water in the second pressure storage injection system is injected into the lower plenum of the reactor pressure vessel at a pressure of from 25 to 60 atg. which is lower than the set pressure and a temperature less than 60 0 C, and further in combination with these procedures, cooling water of less than 60 0 C is injected into a high-temperature side piping, in the high-pressure injection system of upstroke of 100 atg. by means of a pump and the low-pressure injection system of upstroke of 20 atg. also by means of a pump, thereby cooling the reactor core. (Aizawa, K.)

  19. Finding Balance Between Biological Groundwater Treatment and Treated Injection Water

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Mark A.; Nielsen, Kellin R.; Byrnes, Mark E.; Simmons, Sally A.; Morse, John J.; Geiger, James B.; Watkins, Louis E.; McFee, Phillip M.; Martins, K.

    2015-01-14

    At the U.S. Department of Energy’s Hanford Site, CH2M HILL Plateau Remediation Company operates the 200 West Pump and Treat which was engineered to treat radiological and chemical contaminants in groundwater as a result of the site’s former plutonium production years. Fluidized bed bioreactors (FBRs) are used to remove nitrate, metals, and volatile organic compounds. Increasing nitrate concentrations in the treatment plant effluent and the presence of a slimy biomass (a typical microorganism response to stress) in the FBRs triggered an investigation of nutrient levels in the system. Little, if any, micronutrient feed was coming into the bioreactors. Additionally, carbon substrate (used to promote biological growth) was passing through to the injection wells, causing biological fouling of the wells and reduced specific injectivity. Adjustments to the micronutrient feed improved microorganism health, but the micronutrients were being overfed (particularly manganese) plugging the injection wells further. Injection well rehabilitation to restore specific injectivity required repeated treatments to remove the biological fouling and precipitated metal oxides. A combination of sulfamic and citric acids worked well to dissolve metal oxides and sodium hypochlorite effectively removed the biological growth. Intensive surging and development techniques successfully removed clogging material from the injection wells. Ultimately, the investigation and nutrient adjustments took months to restore proper balance to the microbial system and over a year to stabilize injection well capacities. Carefully tracking and managing the FBRs and well performance monitoring are critical to balancing the needs of the treatment system while reducing fouling mechanisms in the injection wells.

  20. Effects of temperature on SCC propagation in high temperature water injected with hydrogen peroxide

    International Nuclear Information System (INIS)

    Nakano, Junichi; Sato, Tomonori; Kato, Chiaki; Yoshiyuki, Kaji; Yamamoto, Masahiro; Tsukada, Takashi

    2012-09-01

    To understand the stress corrosion cracking (SCC) behaviour of austenitic stainless steels (SSs) in the boiling water reactor (BWR) coolant environment, it is significant to investigate the effect of hydrogen peroxide (H 2 O 2 ) produced by the radiolysis of water on SCC under the various water chemistry and operational conditions. At the start-up or shut-down periods, for example, the conditions of radiation and temperature on the structural materials are different from those during the plant normal operation, and may be influencing on SCC behaviour. Therefore, the effect of temperature on SCC in high temperature water injected with H 2 O 2 was evaluated by SCC propagation test at the present study. Oxide films on the metal surface in crack were examined and the thermal equilibrium diagram was calculated to estimate the environmental situation in the crack. On the thermally sensitized type 304 SS, crack growth tests were conducted in high temperature water injected with H 2 O 2 to simulate water radiolysis in the core. Small CT type specimens with a width of 15.5 mm and thickness of 6.2 mm were machined from the sensitized SS. SCC growth tests were conducted in high temperature water injected with 100 ppb H 2 O 2 at 453 and 561 K. To minimize H 2 O 2 decomposition by a contact with metal surface of autoclave, the CT specimen was isolated from inner surface of the autoclave by the inner modules made of polytetrafluoroethylene (PTFE), and PTFE lining was also used for the inner surface of inlet and sampling tubes. Base on the measurement of sampled water, it was confirmed that 80-90 % of injected H 2 O 2 remained around the CT specimen in autoclave. Constant load at initial K levels of 11-20 MPam 1/2 was applied to the CT specimens during crack growth tests. After crack growth tests, CT specimens were split into two pieces on the plane of crack propagation. Scanning electron microscope (SEM) examination and laser Raman spectroscopy for outer oxide layer of oxide

  1. 40 CFR 60.4335 - How do I demonstrate compliance for NOX if I use water or steam injection?

    Science.gov (United States)

    2010-07-01

    ... if I use water or steam injection? 60.4335 Section 60.4335 Protection of Environment ENVIRONMENTAL... compliance for NOX if I use water or steam injection? (a) If you are using water or steam injection to... monitor and record the fuel consumption and the ratio of water or steam to fuel being fired in the turbine...

  2. Inferring the source of evaporated waters using stable H and O isotopes

    Science.gov (United States)

    Stable isotope ratios of H and O are widely used to identify the source of water, e.g., in aquifers, river runoff, soils, plant xylem, and plant-based beverages. In situations where the sampled water is partially evaporated, its isotope values will have evolved along an evaporati...

  3. Comparing Stable Water Isotope Variation in Atmospheric Moisture Observed over Coastal Water and Forests

    Science.gov (United States)

    Lai, C. T.; Rambo, J. P.; Welp, L. R.; Bible, K.; Hollinger, D. Y.

    2014-12-01

    Stable oxygen (δ18O) and hydrogen (δD) isotopologues of atmospheric moisture are strongly influenced by large-scale synoptic weather cycles, surface evapotranspiration and boundary layer mixing. Atmospheric water isotope variation has been shown to empirically relate to relative humidity (Rh) of near surface moisture, and to a less degree, air temperature. Continuous δ18O and δD measurements are becoming more available, providing new opportunities to investigate processes that control isotope variability. This study shows the comparison of δ18O and δD measured at a continental location and over coastal waters for 3 seasons (spring to fall, 2014). The surface moisture isotope measurements were made using two LGR spectroscopy water vapor isotope analyzers (Los Gatos Research Inc.), one operated in an old-growth coniferous forest at Wind River field station, WA (45.8205°N, 121.9519°W), and another sampling marine air over seawater at the Scripps Pier in San Diego, CA (32.8654°N, 117.2536°W), USA. Isotope variations were measured at 1Hz and data were reported as hourly averages with an overall accuracy of ±0.1‰ for δ18O, ±0.5‰ for δ2H. Day-to-day variations in δ18O and δD are shown strongly influenced by synoptic weather events at both locations. Boundary layer mixing between surface moisture and the dry air entrained from the free troposphere exerts a midday maximum and a consistent diel pattern in deuterium excess (dx). At the forest site, surface moisture also interacts with leaf water through transpiration during the day and re-equilibration at night. The latter occurs by retro-diffusion of atmospheric H2O molecules into leaf intercellular space, which becomes intensified as Rh increaes after nightfall, and continues until sunrise, to counter-balance the evaporative isotopic enrichment in leaf water on a daily basis. These vegetation effects lead to negative dx values consistently observed at nighttime in this continental location that were not

  4. GROUND WATER ISSUE: STEAM INJECTION FOR SOIL AND AQUIFER REMEDIATION

    Science.gov (United States)

    The purpose of this Issue Paper is to provide to those involved in assessing remediation technologies for specific sites basic technical information on the use of steam injection for the remediation of soils and aquifers that are contaminated by volatile or semivolatile organic c...

  5. Stable water isotope and surface heat flux simulation using ISOLSM: Evaluation against in-situ measurements

    KAUST Repository

    Cai, Mick Y.; Wang, Lixin; Parkes, Stephen; Strauss, Josiah; McCabe, Matthew; Evans, Jason P.; Griffiths, Alan D.

    2015-01-01

    The stable isotopes of water are useful tracers of water sources and hydrological processes. Stable water isotope-enabled land surface modeling is a relatively new approach for characterizing the hydrological cycle, providing spatial and temporal variability for a number of hydrological processes. At the land surface, the integration of stable water isotopes with other meteorological measurements can assist in constraining surface heat flux estimates and discriminate between evaporation (E) and transpiration (T). However, research in this area has traditionally been limited by a lack of continuous in-situ isotopic observations. Here, the National Centre for Atmospheric Research stable isotope-enabled Land Surface Model (ISOLSM) is used to simulate the water and energy fluxes and stable water isotope variations. The model was run for a period of one month with meteorological data collected from a coastal sub-tropical site near Sydney, Australia. The modeled energy fluxes (latent heat and sensible heat) agreed reasonably well with eddy covariance observations, indicating that ISOLSM has the capacity to reproduce observed flux behavior. Comparison of modeled isotopic compositions of evapotranspiration (ET) against in-situ Fourier Transform Infrared spectroscopy (FTIR) measured bulk water vapor isotopic data (10. m above the ground), however, showed differences in magnitude and temporal patterns. The disparity is due to a small contribution from local ET fluxes to atmospheric boundary layer water vapor (~1% based on calculations using ideal gas law) relative to that advected from the ocean for this particular site. Using ISOLSM simulation, the ET was partitioned into E and T with 70% being T. We also identified that soil water from different soil layers affected T and E differently based on the simulated soil isotopic patterns, which reflects the internal working of ISOLSM. These results highlighted the capacity of using the isotope-enabled models to discriminate

  6. Stable water isotope and surface heat flux simulation using ISOLSM: Evaluation against in-situ measurements

    KAUST Repository

    Cai, Mick Y.

    2015-04-01

    The stable isotopes of water are useful tracers of water sources and hydrological processes. Stable water isotope-enabled land surface modeling is a relatively new approach for characterizing the hydrological cycle, providing spatial and temporal variability for a number of hydrological processes. At the land surface, the integration of stable water isotopes with other meteorological measurements can assist in constraining surface heat flux estimates and discriminate between evaporation (E) and transpiration (T). However, research in this area has traditionally been limited by a lack of continuous in-situ isotopic observations. Here, the National Centre for Atmospheric Research stable isotope-enabled Land Surface Model (ISOLSM) is used to simulate the water and energy fluxes and stable water isotope variations. The model was run for a period of one month with meteorological data collected from a coastal sub-tropical site near Sydney, Australia. The modeled energy fluxes (latent heat and sensible heat) agreed reasonably well with eddy covariance observations, indicating that ISOLSM has the capacity to reproduce observed flux behavior. Comparison of modeled isotopic compositions of evapotranspiration (ET) against in-situ Fourier Transform Infrared spectroscopy (FTIR) measured bulk water vapor isotopic data (10. m above the ground), however, showed differences in magnitude and temporal patterns. The disparity is due to a small contribution from local ET fluxes to atmospheric boundary layer water vapor (~1% based on calculations using ideal gas law) relative to that advected from the ocean for this particular site. Using ISOLSM simulation, the ET was partitioned into E and T with 70% being T. We also identified that soil water from different soil layers affected T and E differently based on the simulated soil isotopic patterns, which reflects the internal working of ISOLSM. These results highlighted the capacity of using the isotope-enabled models to discriminate

  7. Fault Diagnosis Of A Water For Injection System Using Enhanced Structural Isolation

    DEFF Research Database (Denmark)

    Laursen, Morten; Blanke, Mogens; Düstegör, Dilek

    2008-01-01

    A water for injection system supplies chilled sterile water as solvent to pharmaceutical products. There are ultimate requirements to the quality of the sterile water, and the consequence of a fault in temperature or in flow control within the process may cause loss of one or more batches...

  8. Air-water mixing experiments for direct vessel injection of KNGR

    International Nuclear Information System (INIS)

    Hwang, Do Hyun

    2000-02-01

    Two air-water mixing experiments are conducted to understand the flow behavior in the downcomer for Direct Vessel Injection (DVI) of Korean Next Generation Reactor (KNGR). In the first experiment which is an air-water experiment in the rectangular channel with the gap size of 1cm, the width of water film is proportional to the water and air velocities and the inclined angle is proportional to the water velocity only, regardless of the water velocity injected in the rectangular channel. It is observed that the amount of entrained water is negligible. In the second experiment which is a full-scaled water jetting experiment without air flow, the width of water film is proportional to the flow rate injected from the pipe exit and the film thickness of water varies from 1.0mm to 5.0mm, and the maximum thickness does not exceed 5.0mm. The amount of water separated from the liquid film after striking of water jetting on the wall is measured. The amount of separation water is proportional to the flow rate, but the separation ratio in the full-scaled water jetting is not over 15%. A simplified physical model, which is designed to predict the trajectories of the width of water film, is validated through the comparison with experiment results. The 13 .deg. upward water droplet of the water injected from the pipe constitutes the outermost boundary at 1.7m below from pipe level, after the water impinges against the wall. In the model, the parameter, η which represents the relationship between the jetting velocity and the initial spreading velocity, is inversely proportional to the water velocity when it impinges against the wall. The error of the predictions by the model is decreased within 14% to the experimental data through use of exponential fitting of η for the jetting water velocity

  9. Performance indicators for water injections projects; Indicadores de desempenho para projetos de injecao de agua

    Energy Technology Data Exchange (ETDEWEB)

    Hastenreiter, Livia; Correa, Antonio C. de F.; Mendes, Roberta A. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Currently, the water injection process into oil reservoirs is the method of secondary recovery more important to increase the recovery factor. Thus, it is necessary an efficient project management, with constant data acquisitions and interpretation. This paper aims to present some indicators to evaluate the performance of water injection projects. Each indicator is presented based on a methodology that transforms the data collected in information. The results are expressed in graphical form for better viewing of the indicators measurement. (author)

  10. Influence of Steam Injection and Water-in-Oil Emulsions on Diesel Fuel Combustion Performance

    Science.gov (United States)

    Sung, Meagan

    Water injection can be an effective strategy for reducing NOx because water's high specific heat allows it to absorb heat and lower system temperatures. Introducing water as an emulsion can potentially be more effective at reducing emissions than steam injection due to physical properties (such as microexplosions) that can improve atomization and increase mixing. Unfortunately, the immiscibility of emulsions makes them difficult to work with so they must be mixed properly. In this effort, a method for adequately mixing surfactant-free emulsions was established and verified using high speed cinematography. As the water to fuel mass ratio (W/F) increased, emulsion atomization tests showed little change in droplet size and spray angle, but a shorter overall breakup point. Dual-wavelength planar laser induced fluorescence (D-PLIF) patternation showed an increase in water near the center of the spray. Steam injection flames saw little change in reaction stability, but emulsion flames experienced significant losses in stability that limited reaction operability at higher W/F. Emulsions were more effective at reducing NOx than steam injection, likely because of liquid water's latent heat of vaporization and the strategic injection of water into the flame core. OH* chemiluminescence showed a decrease in heat release for both methods, though the decrease was greater for emulsions. Both methods saw decreases in flame length for W/F 0.15. Lastly, flame imaging showed a shift towards a redder appearance with the addition or more water, as well as a reduction in flame flares.

  11. Prediction of the extent of formation damage caused by water injection

    Energy Technology Data Exchange (ETDEWEB)

    Al-Homadhi, Emad S. [King Saud Univ., Riyadh (Saudi Arabia). Petroleum Engineering Dept.

    2013-06-15

    As a general practice water is injected along the O/W contact to maintain reservoir pressure during production. Down hole analysis of the injected water shows that, even after surface treatment, it still can contain a considerable amount of solid particles. These particles can bridge formation pores and cause a considerable reduction in the injectivity. To ensure good injectivity over a longer term, the concentration and size of these solids should not exceed certain limits. In this article core flood tests were carried out to simulate high rate injectors. The injected brine contained solid particles in different concentrations and sizes. Particle concentration was between 5 and 20 ppm and the particle mean size was between 2 and 9 {mu}m. The results were presented as damaging ratio versus pore volume injected. Contrarily to previous studies instead of using experimental results in calibrating or evaluating certain theoretical models, the results in this study were directly fitted to produce equations which can predict the extent of damage caused by injected water by knowing the mean size and concentration of the solid particles contained in that water. (orig.)

  12. Permeability of fissured rock - an experimental study with special regard to the water injection test

    International Nuclear Information System (INIS)

    Schneider, H.J.

    1987-01-01

    The permeability to water of fissured rock is one of the most important design parameters for many underground projects, such as, e.g. the final deposition of radioactive waste. Because the conventional water injection test according to LUGEON for the calculation of permeability to water is associated with a high degree of uncertainty, new test equipment was developed. This equipment works on the principle of the water injection tracer test and multi-level measurements, enabling detailed measurement of the flow process at injection site and in the rock. The tests were carried out in Bunter sandstone and granite. The LUGEON test concept was varied in short-term and long-term tests at identical geological boundary conditions, and with test control at constant pressure on the one hand and at constant injection volume on the other. The test results show that non-steady-state flow occurs with short injection times, whereby the range is limited to the local rock at injection site. An increasing in injection time can lead to an increase in range by a number of factors as well as to steady-state flow conditions. The permeability of the rock types investigated is inhomgeneous and anistropic as a result of the fissured structure. (orig./HP) With 114 figs., 4 tabs [de

  13. Stable isotope hydrology. Deuterium and oxygen-18 in the water cycle

    International Nuclear Information System (INIS)

    Gat, J.R.; Gonfiantini, R.

    1981-01-01

    This monograph is mainly intended for hydrologists, hydrogeologists and geochemists who want to become acquainted, rapidly but in some detail, with the theoretical background of stable isotope fractionation in natural physico-chemical processes involving fresh water, with the isotopic differences actually encountered in natural waters and with their use for practical hydrological purposes. Throughout the monograph, and in particular in the last chapter, a series of examples are discussed, giving the results obtained with stable isotope techniques in current hydrological and hydrogeological investigations or, more generally, in water resources exploration and assessment. One chapter is also dedicated to the techniques for measuring D/H and 18 O/ 16 O ratios in water

  14. Integrated hydraulic and organophosphate pesticide injection simulations for enhancing event detection in water distribution systems.

    Science.gov (United States)

    Schwartz, Rafi; Lahav, Ori; Ostfeld, Avi

    2014-10-15

    As a complementary step towards solving the general event detection problem of water distribution systems, injection of the organophosphate pesticides, chlorpyrifos (CP) and parathion (PA), were simulated at various locations within example networks and hydraulic parameters were calculated over 24-h duration. The uniqueness of this study is that the chemical reactions and byproducts of the contaminants' oxidation were also simulated, as well as other indicative water quality parameters such as alkalinity, acidity, pH and the total concentration of free chlorine species. The information on the change in water quality parameters induced by the contaminant injection may facilitate on-line detection of an actual event involving this specific substance and pave the way to development of a generic methodology for detecting events involving introduction of pesticides into water distribution systems. Simulation of the contaminant injection was performed at several nodes within two different networks. For each injection, concentrations of the relevant contaminants' mother and daughter species, free chlorine species and water quality parameters, were simulated at nodes downstream of the injection location. The results indicate that injection of these substances can be detected at certain conditions by a very rapid drop in Cl2, functioning as the indicative parameter, as well as a drop in alkalinity concentration and a small decrease in pH, both functioning as supporting parameters, whose usage may reduce false positive alarms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Environmental response nanosilica for reducing the pressure of water injection in ultra-low permeability reservoirs

    Science.gov (United States)

    Liu, Peisong; Niu, Liyong; Li, Xiaohong; Zhang, Zhijun

    2017-12-01

    The super-hydrophobic silica nanoparticles are applied to alter the wettability of rock surface from water-wet to oil-wet. The aim of this is to reduce injection pressure so as to enhance water injection efficiency in low permeability reservoirs. Therefore, a new type of environmentally responsive nanosilica (denote as ERS) is modified with organic compound containing hydrophobic groups and "pinning" groups by covalent bond and then covered with a layer of hydrophilic organic compound by chemical adsorption to achieve excellent water dispersibility. Resultant ERS is homogeneously dispersed in water with a size of about 4-8 nm like a micro-emulsion system and can be easily injected into the macro or nano channels of ultra-low permeability reservoirs. The hydrophobic nanosilica core can be released from the aqueous delivery system owing to its strong dependence on the environmental variation from normal condition to injection wells (such as pH and salinity). Then the exposed silica nanoparticles form a thin layer on the surface of narrow pore throat, leading to the wettability from water-wet to oil-wet. More importantly, the two rock cores with different permeability were surface treated with ERS dispersion with a concentration of 2 g/L, exhibit great reduce of water injection pressure by 57.4 and 39.6%, respectively, which shows great potential for exploitation of crude oil from ultra-low permeability reservoirs during water flooding. [Figure not available: see fulltext.

  16. Thermo-hydraulic behavior of saturated steam-water mixture in pressure vessel during injection of cold water

    International Nuclear Information System (INIS)

    Aya, Izuo; Kobayashi, Michiyuki; Inasaka, Fujio; Nariai, Hideki.

    1983-01-01

    The thermo-hydraulic behavior of saturated steam water mixture in a pressure vessel during injection of cold water was experimentally investigated with the Facility for Mixing Effect of Emergency Core Cooling Water. The dimensions of the pressure vessel used in the experiments were 284mm ID and 1,971mm height. 11 experiments were conducted without blowdown in order to comprehend the basic process excluding the effect of blowdown at injection of cold water. The initial pressure and water level, the injection flow rate and the size of injection nozzle were chosen as experimental parameters. Temperatures and void fractions at 6 elevations as well as pressure in the pressure vessel were measured, and new data especially on the pressure undershoot just after the initation of water injection and the vertical distribution of temperature and void fraction were gotten. The transients of pressure, average temperature and void fraction were caluculated using single-volume analysis code BLODAC-1V which is based on thermal equilibrium and so-called bubble gradient model. Some input parameters included in the analysis code were evaluated through the comparison of analysis with experimental data. Moreover, the observed pressure undershoot which is evaluated to be induced by a time lag of vapourization in water due to thermal nonequilibrium, was also discussed with the aid of another simple analysis model. (author)

  17. Effect of cold water injection on operation of and oil production from formations of Romashkino field

    Energy Technology Data Exchange (ETDEWEB)

    Mingareev, R Sh; Vakhitov, G G; Sultanov, S A

    1968-11-01

    Each year about 130 million cu m of cold water are injected into this field. Since cold water can lower reservoir temperature, increase oil viscosity, deposit paraffin in the formation, and reduce oil recovery, a thermal survey of this field was conducted. The survey showed that the average reservoir temperature was not reduced by cold-water injection for 15 yr. However, local cooling was observed at distances less than 400 m from the water injection well. Through these wells more than 4 PV of water have passed. The thermal front lags 1,500 m behind the advancing water front. For this reason, cold-water injection does not reduce oil recovery where there is uniform advance of the floodwater. When the formation is heterogeneous so that water advances more rapidly in high-permeability sand than in adjoining low-permeability sand, then the cooling effect can reduce oil recovery. For this reason, it is advisable to force water into the entire interval of the oil formation. An isotherm map of the Romashkino field is shown.

  18. Multisample conversion of water to hydrogen by zinc for stable isotope determination

    Science.gov (United States)

    Kendall, C.; Coplen, T.B.

    1985-01-01

    Two techniques for the conversion of water to hydrogen for stable isotope ratio determination have been developed that are especially suited for automated multisample analysis. Both procedures involve reaction of zinc shot with a water sample at 450 ??C. in one method designed for water samples in bottles, the water is put in capillaries and is reduced by zinc in reaction vessels; overall savings in sample preparation labor of 75% have been realized over the standard uranium reduction technique. The second technique is for waters evolved under vacuum and is a sealed-tube method employing 9 mm o.d. quartz tubing. Problems inherent with zinc reduction include surface inhomogeneity of the zinc and exchange of hydrogen both with the zinc and with the glass walls of the vessels. For best results, water/zinc and water/glass surface area ratios of vessels should be kept as large as possible.

  19. Stable Isotopic Analysis on Water Utilization of Two Xerophytic Shrubs in a Revegetated Desert Area: Tengger Desert, China

    OpenAIRE

    Lei Huang; Zhishan Zhang

    2015-01-01

    Stable isotope studies on stable isotope ratios of hydrogen and oxygen in water within plants provide new information on water sources and water use patterns under natural conditions. In this study, the sources of water uptake for two typical xerophytic shrubs, Caragana korshinskii and Artemisia ordosica, were determined at four different-aged revegetated sites (1956, 1964, 1981, and 1987) in the Tengger Desert, a revegetated desert area in China. Samples from precipitation, soil water at dif...

  20. Three Dimensional Visualization for the Steam Injection into Water Pool using Electrical Resistance Tomography

    International Nuclear Information System (INIS)

    Khambampati, Anil Kumar; Lee, Jeong Seong; Kim, Sin; Kim, Kyung Youn

    2010-01-01

    The direct injection of steam into a water pool is a method of heat transfer used in many process industries. The amount of research in this area however is limited to the nuclear industry, with applications relating to reactor cooling systems. Electrical resistance tomography (ERT), a low cost, non-invasive and which has high temporal resolution characteristics, can be used as a visualization tool for the resistivity distribution for the steam injection into water pool such as IRWST. In this paper, three dimensional resistivity distribution of the process is obtained through ERT using iterative Gauss-Newton method. Numerical experiments are performed by assuming different resistive objects in the water pool. Numerical results show that ERT is successful in estimating the resistivity distribution for the injection of steam in the water pool

  1. Research on the performance of water-injection twin screw compressor

    International Nuclear Information System (INIS)

    Li Jianfeng; Wu Huagen; Wang Bingming; Xing Ziwen; Shu Pengcheng

    2009-01-01

    Due to the development of the automotive fuel cell systems, the study on water-injection twin screw compressor has been aroused again. Twin screw compressors with water injection can be used to supply the clean compressed air for the Proton Exchange Membrane (PEM) fuel cell systems. In this research, a thermodynamic model of the working process of water-injection twin screw compressor was established based on the equations of conservation of mass and energy. The effects of internal leakage and air-water heat transfer were taken into account simultaneously in the present mathematical model. The experiments of the performance of a prototype compressor operating under various conditions were conducted to verify the model. The results show that the predictions of the model are in reasonable agreement with the experimental data.

  2. Evaluation of an accident management strategy of emergency water injection using fire engines in a typical pressurized water reactor

    International Nuclear Information System (INIS)

    Park, Soo Yong; Ahn, Kwang Il

    2015-01-01

    Following the Fukushima accident, a special safety inspection was conducted in Korea. The inspection results show that Korean nuclear power plants have no imminent risk for expected maximum potential earthquake or coastal flooding. However long- and short-term safety improvements do need to be implemented. One of the measures to increase the mitigation capability during a prolonged station blackout (SBO) accident is installing injection flow paths to provide emergency cooling water of external sources using fire engines to the steam generators or reactor cooling systems. This paper illustrates an evaluation of the effectiveness of external cooling water injection strategies using fire trucks during a potential extended SBO accident in a 1,000 MWe pressurized water reactor. With regard to the effectiveness of external cooling water injection strategies using fire engines, the strategies are judged to be very feasible for a long-term SBO, but are not likely to be effective for a short-term SBO

  3. Evaluation of an accident management strategy of emergency water injection using fire engines in a typical pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soo Yong; Ahn, Kwang Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Following the Fukushima accident, a special safety inspection was conducted in Korea. The inspection results show that Korean nuclear power plants have no imminent risk for expected maximum potential earthquake or coastal flooding. However long- and short-term safety improvements do need to be implemented. One of the measures to increase the mitigation capability during a prolonged station blackout (SBO) accident is installing injection flow paths to provide emergency cooling water of external sources using fire engines to the steam generators or reactor cooling systems. This paper illustrates an evaluation of the effectiveness of external cooling water injection strategies using fire trucks during a potential extended SBO accident in a 1,000 MWe pressurized water reactor. With regard to the effectiveness of external cooling water injection strategies using fire engines, the strategies are judged to be very feasible for a long-term SBO, but are not likely to be effective for a short-term SBO.

  4. Influence of Zn injection on corrosion behavior and oxide film characteristics of 304 stainless steel in borated and lithiated high temperature water

    International Nuclear Information System (INIS)

    Wu, Xinqiang; Liu, Xiahe; Han, En-Hou; Ke, Wei

    2012-09-01

    Water chemistry of the reactor coolant system plays a major role in maintaining safety and reliability of light water reactor nuclear power plants (NPPs). Zn water chemistry into pressurized water reactors (PWRs) in order to reduce the radiation buildup in primary coolant system has been widely applied, and the reduction effect has been experimentally confirmed. Zn injection can also lessen the corrosion phenomena in high temperature pressurized water by changing oxide films formed on components materials. Both the radiation buildup and material corrosion resistance in PWR coolant system are closely dependent on the oxide films formed. However, the influence of Zn injection on the chemical composition and structure of the oxide films on their protective properties is still a matter of considerable debate. The influence of Zn injection on corrosion inhibition and environmental degradation has not been fully clarified yet. Therefore, the understanding of corrosion behaviour, oxide film characteristics and their protective property is of significance to clarify the environmentally assisted material failure problems in NPPs. In the present work, oxide films formed on nuclear-grade 304 SS exposed to borated and lithiated high temperature water environments at 300 deg. C up to 4000 h with or without 10 ppb Zn injection were investigated ex-situ. Without Zn injection, the oxide films mainly consisted of Fe 3 O 4 and FeCr 2 O 4 . With Zn injection, ZnFe 2 O 4 and ZnCr 2 O 4 were detected in the oxide films at the initial stage of immersion and ZnCr 2 O 4 became dominant after long-term immersion. It was believed that the above Zn-Fe and Zn-Cr spinel oxides were formed by substitution reactions between Zn 2+ and Fe 2+ . At the initial stage of immersion, water chemistry significantly affected the formation of the oxide films. Once a stable oxide film formed, it is rather difficult to change its structure through changing water chemistry. The potential-pH diagrams for Zn

  5. Stable sulfur and oxygen isotopes as geochemical tracers of sulfate in karst waters

    Science.gov (United States)

    Sun, Jing; Kobayashi, Tatsuaki; Strosnider, William H. J.; Wu, Pan

    2017-08-01

    Karst water resources, which are extremely sensitive to mining activities, are critical for the support of human societies and ecological systems in many regions worldwide. In order to determine the sources and fate of dissolved sulfate in low-pH karst waters, hydrochemical variations of karst waters with and without acid mine drainage (AMD) impacts were investigated along with stable isotope dynamics. As expected, hydrochemical characteristics and isotopic compositions of the AMD and AMD-downstream water (ADW) were dramatically different from that of the non-AMD-impacted water (NAW). The sources of sulfur isotopes in sulfate were predominantly pyrite oxidation for the AMD and ADW, and atmospheric deposition for the NAW. Based on the general isotope-balance model, the relative proportions of sulfate oxygen derived from water and air were calculated. The mean proportion of sulfate oxygen derived from water in ADW was roughly double that of AMD. This suggests that the sulfate associated with AMD is predominantly influenced by aerobic pyrite oxidation, while that of ADW is likely affected by the dissolution of pyrite under anaerobic conditions in reservoir sediment. This observation was coincident with the noted variations of hydrochemical characteristics and was supported by principal component analysis. These results provide a better understanding of how stable isotopes of sulfate and water can be used to track mining contamination in karst aquifers, which could benefit remediation planning for these distinctive systems.

  6. A new approach of proration-injection allocation for water-flooding mature oilfields

    Directory of Open Access Journals (Sweden)

    Shuyong Hu

    2015-03-01

    Full Text Available This paper presents a new method of injection-production allocation estimation for water-flooding mature oilfields. The suggested approach is based on logistic growth rate functions and several type-curve matching methods. Using the relationship between these equations, oil production and water injection rate as well as injection-production ratio can be easily forecasted. The calculation procedure developed and outlined in this paper requires very few production data and is easily implemented. Furthermore, an oilfield case has been analyzed. The synthetic and field cases validate the calculation procedure, so it can be accurately used in forecasting production data, and it is important to optimize the whole injection-production system.

  7. Determination of nitrate in water by flow-injection analysis

    Czech Academy of Sciences Publication Activity Database

    Mikuška, Pavel; Večeřa, Zbyněk

    2001-01-01

    Roč. 8, č. 1 (2001), s. 115-120 ISSN 1231-7098 R&D Projects: GA ČR GA203/98/0943 Grant - others:COPERNICUS(BE) SUB-AERO EVK2-1999-000327 Institutional research plan: CEZ:AV0Z4031919 Keywords : nitrate * chemiluminescence * water Subject RIV: CB - Analytical Chemistry, Separation

  8. Investigation of Cooling Water Injection into Supersonic Rocket Engine Exhaust

    Science.gov (United States)

    Jones, Hansen; Jeansonne, Christopher; Menon, Shyam

    2017-11-01

    Water spray cooling of the exhaust plume from a rocket undergoing static testing is critical in preventing thermal wear of the test stand structure, and suppressing the acoustic noise signature. A scaled test facility has been developed that utilizes non-intrusive diagnostic techniques including Focusing Color Schlieren (FCS) and Phase Doppler Particle Anemometry (PDPA) to examine the interaction of a pressure-fed water jet with a supersonic flow of compressed air. FCS is used to visually assess the interaction of the water jet with the strong density gradients in the supersonic air flow. PDPA is used in conjunction to gain statistical information regarding water droplet size and velocity as the jet is broken up. Measurement results, along with numerical simulations and jet penetration models are used to explain the observed phenomena. Following the cold flow testing campaign a scaled hybrid rocket engine will be constructed to continue tests in a combusting flow environment similar to that generated by the rocket engines tested at NASA facilities. LaSPACE.

  9. Construction of a Direct Water-Injected Two-Stroke Engine for Phased Direct Fuel Injection-High Pressure Charging Investigations

    Science.gov (United States)

    Somsel, James P.

    1998-01-01

    The development of a water injected Orbital Combustion Process (OCP) engine was conducted to assess the viability of using the powerplant for high altitude NASA aircraft and General Aviation (GA) applications. An OCP direct fuel injected, 1.2 liter, three cylinder, two-stroke engine has been enhanced to independently inject water directly into the combustion chamber. The engine currently demonstrates low brake specific fuel consumption capability and an excellent power to weight ratio. With direct water injection, significant improvements can be made to engine power, to knock limits/ignition advance timing, and to engine NO(x) emissions. The principal aim of the testing was to validate a cyclic model developed by the Systems Analysis Branch at NASA Ames Research Center. The work is a continuation of Ames' investigations into a Phased Direct Fuel Injection Engine with High Pressure Charging (PDFI-ITPC).

  10. Experimental investigation of the effects of direct water injection parameters on engine performance in a six-stroke engine

    International Nuclear Information System (INIS)

    Arabaci, Emre; İçingür, Yakup; Solmaz, Hamit; Uyumaz, Ahmet; Yilmaz, Emre

    2015-01-01

    Highlights: • Exhaust gas temperature and specific fuel consumption decreased with six stroke engine. • Thermal efficiency increased with water injection. • NO emissions decreased with water injection as the temperature decreased at the end of cycle. • Injection timing should be advanced with the increase of engine speed. • HC and CO emissions decrease until 3000 rpm engine speed. - Abstract: In this study, the effects of water injection quantity and injection timing were investigated on engine performance and exhaust emissions in a six-stroke engine. For this purpose, a single cylinder, four-stroke gasoline engine was converted to six-stroke engine modifying a new cam mechanism and adapting the water injection system. The experiments were conducted at stoichometric air/fuel ratio (λ = 1) between 2250 and 3500 rpm engine speed at full load with liquid petroleum gas. Water injection was performed at three different stages as before top dead center, top dead center and after top dead center at constant injection duration and four different injection pressure 25, 50, 75 and 100 bar. The test results showed that exhaust gas temperature and specific fuel consumption decreased by about 7% and 9% respectively. In contrast, fuel consumption and power output increased 2% and 10% respectively with water injection. Thermal efficiency increased by about 8.72% with water injection. CO and HC emissions decreased 21.97% and 18.23% until 3000 rpm respectively. NO emissions decreased with water injection as the temperature decreased at the end of cycle. As a result, it was seen that engine performance improved when suitable injection timing and injected water quantity were selected due to effect of exhaust heat recovery with water injection

  11. In situ water and gas injection experiments performed in the Hades Underground Research Facility

    Energy Technology Data Exchange (ETDEWEB)

    Volckaert, G.; Ortiz, L.; Put, M. [SCK-CEN, Mol (Belgium). Geological Waste Disposal Unit

    1995-12-31

    The movement of water and gas through plastic clay is an important subject in the research at SCK-CEN on the possible disposal of high level radioactive waste in the Boom clay layer at Mol. Since the construction of the Hades underground research facility in 1983, SCK-CEN has developed and installed numerous piezometers for the geohydrologic characterization and for in situ radionuclide migration experiments. In situ gas and water injection experiments have been performed at two different locations in the underground laboratory. The first location is a multi filter piezometer installed vertically at the bottom of the shaft in 1986. The second location is a three dimensional configuration of four horizontal multi piezometers installed from the gallery. This piezometer configuration was designed for the MEGAS (Modelling and Experiments on GAS migration through argillaceous rocks) project and installed in 1992. It contains 29 filters at distances between 10 m and 15 m from the gallery in the clay. Gas injection experiments show that gas breakthrough occurs at a gas overpressure of about 0.6 MPa. The breakthrough occurs by the creation of gas pathways along the direction of lowest resistance i.e. the zone of low effective stress resulting from the drilling of the borehole. The water injections performed in a filter -- not used for gas injection -- show that the flow of water is also influenced by the mechanical stress conditions. Low effective stress leads to higher hydraulic conductivity. However, water overpressures up to 1.3 MPa did not cause hydrofracturing. Water injections performed in a filter previously used for gas injections, show that the occluded gas hinders the water flow and reduces the hydraulic conductivity by a factor two.

  12. Effect Of Hot Water Injection On Sandstone Permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Fabricius, Ida Lykke

    2012-01-01

    of published results regarding the effect of temperature on sandstone permeability. These tests are performed with mineral oil, nitrogen gas, distilled water and solutions of NaCl, KCl, CaCl2 as well as brines that contain a mixture of salts. Thirteen sandstone formations, ranging from quartz arenites...... to formations with a significant fraction of fine particles including clay minerals are investigated. The porosities range from 0.10 to 0.30 and permeabilities span the range from 1 to 1000 md. To compare different rock types, specific surface is determined from permeability and porosity using Kozeny’s equation...... not account for all the permeability reductions observed. Permeablity reduction occurs both when distilled water is the saturating fluid as well as in tests with NaCl, KCl or CaCl2 solutions, however, this is not the case in tests with mineral oil or nitrogen gas. The formation of a filter cake or influx...

  13. New method for simultaneous determination of Fe(II) and Fe(III) in water using flow injection technique

    International Nuclear Information System (INIS)

    Kozak, J.; Gutowski, J.; Kozak, M.; Wieczorek, M.; Koscielniak, P.

    2010-01-01

    The method exploits the possibilities of flow injection gradient titration in a system of reversed flow with spectrophotometric detection. In the developed approach a small amount of titrant (EDTA) is injected into a stream of sample containing a mixture of indicators (sulfosalicylic acid and 1,10-phenanthroline). In acid environment sulfosalicylic acid forms a complex with Fe(III), whereas 1,10-phenanthroline forms a complex with Fe(II). Measurements are performed at wavelength λ = 530 nm when radiation is absorbed by both complexes. After injection EDTA replaces sulfosalicylic acid and forms with Fe(III) more stable colourless complex. As a result, a characteristic 'cut off' peak is registered with a width corresponding to the Fe(III) concentration and with a height corresponding to the Fe(II) concentration. Calibration was performed by titration of four two-component standard solutions of the Fe(II)/Fe(III) concentrations established in accordance with 2 2 factorial plan. The method was tested with the use of synthetic samples and then it was applied to the analysis of water samples taken from artesian wells. Under optimized experimental conditions Fe(II) and Fe(III) were determined with precision less than 0.8 and 2.5% (RSD) and accuracy less than 3.2 and 5.1% (relative error) within the concentration ranges of 0.1-3.0 and 0.9-3.5 mg L -1 of both analytes, respectively.

  14. Tracing water sources of terrestrial animal populations with stable isotopes: laboratory tests with crickets and spiders.

    Directory of Open Access Journals (Sweden)

    Kevin E McCluney

    2010-12-01

    Full Text Available Fluxes of carbon, nitrogen, and water between ecosystem components and organisms have great impacts across levels of biological organization. Although much progress has been made in tracing carbon and nitrogen, difficulty remains in tracing water sources from the ecosystem to animals and among animals (the "water web". Naturally occurring, non-radioactive isotopes of hydrogen and oxygen in water provide a potential method for tracing water sources. However, using this approach for terrestrial animals is complicated by a change in water isotopes within the body due to differences in activity of heavy and light isotopes during cuticular and transpiratory water losses. Here we present a technique to use stable water isotopes to estimate the mean mix of water sources in a population by sampling a group of sympatric animals over time. Strong correlations between H and O isotopes in the body water of animals collected over time provide linear patterns of enrichment that can be used to predict a mean mix of water sources useful in standard mixing models to determine relative source contribution. Multiple temperature and humidity treatment levels do not greatly alter these relationships, thus having little effect on our ability to estimate this population-level mix of water sources. We show evidence for the validity of using multiple samples of animal body water, collected across time, to estimate the isotopic mix of water sources in a population and more accurately trace water sources. The ability to use isotopes to document patterns of animal water use should be a great asset to biologists globally, especially those studying drylands, droughts, streamside areas, irrigated landscapes, and the effects of climate change.

  15. Tracing water sources of terrestrial animal populations with stable isotopes: laboratory tests with crickets and spiders.

    Science.gov (United States)

    McCluney, Kevin E; Sabo, John L

    2010-12-31

    Fluxes of carbon, nitrogen, and water between ecosystem components and organisms have great impacts across levels of biological organization. Although much progress has been made in tracing carbon and nitrogen, difficulty remains in tracing water sources from the ecosystem to animals and among animals (the "water web"). Naturally occurring, non-radioactive isotopes of hydrogen and oxygen in water provide a potential method for tracing water sources. However, using this approach for terrestrial animals is complicated by a change in water isotopes within the body due to differences in activity of heavy and light isotopes during cuticular and transpiratory water losses. Here we present a technique to use stable water isotopes to estimate the mean mix of water sources in a population by sampling a group of sympatric animals over time. Strong correlations between H and O isotopes in the body water of animals collected over time provide linear patterns of enrichment that can be used to predict a mean mix of water sources useful in standard mixing models to determine relative source contribution. Multiple temperature and humidity treatment levels do not greatly alter these relationships, thus having little effect on our ability to estimate this population-level mix of water sources. We show evidence for the validity of using multiple samples of animal body water, collected across time, to estimate the isotopic mix of water sources in a population and more accurately trace water sources. The ability to use isotopes to document patterns of animal water use should be a great asset to biologists globally, especially those studying drylands, droughts, streamside areas, irrigated landscapes, and the effects of climate change.

  16. Assessment of ground water quality in a fractured aquifer under continue wastewater injection

    International Nuclear Information System (INIS)

    Carrieri, C.; Masciopinto, C.

    2000-01-01

    Experimental studies have been carried out in a fractured coastal aquifer of the Salento Region (Nardo' (Le) Italy), subject since 1991 to injection of 12000 m 3 /d of treated municipal wastewater in a natural sink. The analytical parameters of ground water sampled in monitoring wells, have been compared before and after the injection started. The mound of water table (1.5 m), the reduction of seawater extent of 2 km and the spreading of pollutants injected were evaluated by means of mathematical model results. After ten years operation, the volume of the available resource for agricultural and drinking use has been increased, without notable decrease of the pre existent ground water quality. Moreover for preserving such resource from pollution, the mathematical model allowed the standards of wastewater quality for recharge to be identified. Around the sink, a restricted area was also defined with prohibition of withdrawals, to avoid infection and other risks on human health [it

  17. SATCAP-C : a program for thermal hydraulic design of pressurized water injection type capsule

    International Nuclear Information System (INIS)

    Harayama, Yasuo; Someya, Hiroyuki; Asoh, Tomokazu; Niimi, Motoji

    1992-10-01

    There are capsules called 'Pressure Water Injection Type Capsule' as a kind of irradiation devices at the Japan Materials Testing Reactor (JMTR). A type of the capsules is a 'Boiling Water Capsule' (usually named BOCA). The other type is a 'Saturated Temperature Capsule' (named SATCAP). When the water is kept at a constant pressure, the water temperature does not become higher than the saturated temperature so far as the water does not fully change to steam. These type capsules are designed on the basis of the conception of applying the water characteristic to the control of irradiation temperature of specimens in the capsules. In designing of the capsules in which the pressurized water is injected, thermal performances have to be understood as exactly as possible. It is not easy however to predict thermal performances such as axially temperature distribution of water injected in the capsule, because there are heat-sinks at both side of inner and outer of capsule casing as the result that the water is fluid. Then, a program (named SATCAP-C) for the BOCA and SATCAP was compiled to grasp the thermal performances in the capsules and has been used the design of the capsules and analysis of the data obtained from some actual irradiation capsules. It was confirmed that the program was effective in thermal analysis for the capsules. The analysis found out the values for heat transfer coefficients at various surfaces of capsule components and some thermal characteristics of capsules. (author)

  18. Water injection into vapor- and liquid-dominated reservoirs: Modeling of heat transfer and mass transport

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, K.; Oldenburg, C.; Moridis, G.; Finsterle, S. [Lawrence Berkeley National Lab., CA (United States)

    1997-12-31

    This paper summarizes recent advances in methods for simulating water and tracer injection, and presents illustrative applications to liquid- and vapor-dominated geothermal reservoirs. High-resolution simulations of water injection into heterogeneous, vertical fractures in superheated vapor zones were performed. Injected water was found to move in dendritic patterns, and to experience stronger lateral flow effects than predicted from homogeneous medium models. Higher-order differencing methods were applied to modeling water and tracer injection into liquid-dominated systems. Conventional upstream weighting techniques were shown to be adequate for predicting the migration of thermal fronts, while higher-order methods give far better accuracy for tracer transport. A new fluid property module for the TOUGH2 simulator is described which allows a more accurate description of geofluids, and includes mineral dissolution and precipitation effects with associated porosity and permeability change. Comparisons between numerical simulation predictions and data for laboratory and field injection experiments are summarized. Enhanced simulation capabilities include a new linear solver package for TOUGH2, and inverse modeling techniques for automatic history matching and optimization.

  19. Perspectives on Severe Accident Management by Depressurization and External Water Injection under Extended SBO Conditions

    International Nuclear Information System (INIS)

    Seol, Wookcheol; Park, Jongwoon

    2014-01-01

    Three major issues of severe accident management guideline (SAMG) after this sort of extended SBO would be depressurization of the primary system, external water injection and hydrogen management inside a containment. Under this situation, typical SAM actions would be depressurization and external water delivery into the core. However, limited amount of external water would necessitate optimization between core cooling, containment integrity and fission product removal. In this paper, effects of SAM actions such as depressurization and external water injection on the reactor and containment conditions after extended SBO are analyzed using MAAP4 code. Positive and negative aspects are discussed with respect to core cooling and fission product retention inside a primary system. Conclusions are made as following: Firstly, early depressurization action itself has two-faces: positive with respect to delay of the reactor vessel failure but negative with respect to the containment failure and fission product retention inside the primary system. Secondly, in order to prevent containment overpressure failure after external water injection, re-closing of PORV later should be considered in SAM, which has never been considered in the previous SAMG. Finally, in case of external water injection, the flow rate should be optimized considering not only the cooling effect but also the long term fission product retention inside the primary system

  20. The Use of Stable Isotope Tracers to Quantify the Transit Time Distribution of Water

    Science.gov (United States)

    Gray, T. M.; Troch, P. A. A.

    2016-12-01

    Water pollution is an important societal problem because it can have harmful effects on human and ecological health. In order to improve water quality, scientists must develop land management methods that can avoid or mitigate environmental pollution. State of the art tools to develop such methods are flow and transport models that trace water and other solutes through the landscape. These models deliver important information that can lead to remediation efforts, and improve the quality of water for humans, plants, and animals. However, these models may be difficult to apply since many details about the catchment may not be available. Instead, a lumped approach is often used to find the water transit time using stable isotope tracers such as 18O and 2H that are naturally applied by precipitation to a catchment. The transit time distribution of water is an important indicator for the amount of solutes soil water and groundwater can contain, and thus a predictor of water quality. We conducted a 2-week long experiment using a tilted weighing lysimeter at Biosphere 2 to observe the breakthrough curves of deuterium and specific artificial DNA particles. We show that hydrological parameters can be computed in order to provide an estimate for the transit time distribution of deuterium. The convolution integral is then used to determine the distribution of the water transit time in the system. Unfortunately, stable isotopes such as deuterium make it difficult to pinpoint a specific flowpath since they naturally occur in the environment. Recent studies have shown that DNA tracers are able to trace water through the landscape. We found that DNA has a similar breakthrough curve happening at similar timescales as the deuterium. Therefore, DNA tracers may be able to identify sources of nonpoint source pollution in the future.

  1. Stable Isotope Analyses of water and Aqueous Solutions by Conventional Dual-inlet Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Horita, Juske [ORNL; Kendall, C. [U.S. Geological Survey, Menlo Park, CA

    2004-01-01

    The foundation of various analytical methods for the stable isotope composition of water and other aqueous samples (natural abundance, {sup 1}H : {sup 2}H (D) = 99.985 : 0.015 atom%, and {sup 16}O : {sup 17}O : {sup 18}O = 99.762 : 0.038 : 0.200 atom%) was established during the Manhatten Project in the U.S.A., when large amounts of heavy water were produced for nuclear reactors (see Kirshenbaum, 1951, for a detailed account). From early on, there was great interest in the oxygen and hydrogen isotopic compositions of water, because they are the ideal tracers of water sources and reactions. The increased analytical precisions made possible by the subsequent development of modern gas-source isotope-ratio mass spectrometers with dual-inlets and multi-collectors, have caused the proliferation of new analytical methods and applications for the oxygen and hydrogen isotopic compositions of water. These stable isotopes have found wide applications in basic as well as applied sciences (chemistry, geology, hydrology, biology, medical sciences, and food sciences). This is because water is ubiquitous, is an essential and predominant ingredient of living organisms, and is perhaps the most reactive compound in the Earth.

  2. Reticular Chemistry in Action: A Hydrolytically Stable MOF Capturing Twice Its Weight in Adsorbed Water

    KAUST Repository

    Towsif Abtab, Sk Md; Alezi, Dalal; Bhatt, Prashant; Shkurenko, Aleksander; Belmabkhout, Youssef; Aggarwal, Himanshu; Weselinski, Lukasz Jan; Alsadun, Norah Sadun; Samin, Umer; Hedhili, Mohamed N.; Eddaoudi, Mohamed

    2018-01-01

    Summary Hydrolytically stable adsorbents, with notable water uptake, are of prime importance and offer great potential for many water-adsorption-related applications. Nevertheless, deliberate construction of tunable porous solids with high porosity and high stability remains challenging. Here, we present the successful deployment of reticular chemistry to address this demand: we constructed Cr-soc-MOF-1, a chemically and hydrolytically stable chromium-based metal-organic framework (MOF) with underlying soc topology. Prominently, Cr-soc-MOF-1 offers the requisite thermal and chemical stability concomitant with unique adsorption properties, namely extraordinary high porosity (apparent surface area of 4,549 m2/g) affording a water vapor uptake of 1.95 g/g at 70% relative humidity. This exceptional water uptake is maintained over more than 100 adsorption-desorption cycles. Markedly, the adsorbed water can be fully desorbed by just the simple reduction of the relative humidity at 25°C. Cr-soc-MOF-1 offers great potential for use in applications pertaining to water vapor control in enclosed and confined spaces and dehumidification.

  3. Reticular Chemistry in Action: A Hydrolytically Stable MOF Capturing Twice Its Weight in Adsorbed Water

    KAUST Repository

    Towsif Abtab, Sk Md

    2018-01-11

    Summary Hydrolytically stable adsorbents, with notable water uptake, are of prime importance and offer great potential for many water-adsorption-related applications. Nevertheless, deliberate construction of tunable porous solids with high porosity and high stability remains challenging. Here, we present the successful deployment of reticular chemistry to address this demand: we constructed Cr-soc-MOF-1, a chemically and hydrolytically stable chromium-based metal-organic framework (MOF) with underlying soc topology. Prominently, Cr-soc-MOF-1 offers the requisite thermal and chemical stability concomitant with unique adsorption properties, namely extraordinary high porosity (apparent surface area of 4,549 m2/g) affording a water vapor uptake of 1.95 g/g at 70% relative humidity. This exceptional water uptake is maintained over more than 100 adsorption-desorption cycles. Markedly, the adsorbed water can be fully desorbed by just the simple reduction of the relative humidity at 25°C. Cr-soc-MOF-1 offers great potential for use in applications pertaining to water vapor control in enclosed and confined spaces and dehumidification.

  4. The use of stable isotopes in quantitative determinations of exogenous water and added ethanol in wines

    Science.gov (United States)

    Magdas, D. A.; Moldovan, Z.; Cristea, G.

    2012-02-01

    The application of oxygen isotope ratios analysis to wine water according to EU regulation no. 822/97 to determine wine's origin and also, the possible water addition to wines, gained great importance in wines authenticity control. In the natural cycle of water isotopic fractionation, during water evaporation process, the water vapors are depleted in heavy isotopes. On the other hand inside the plants take place an isotope enrichment of heavy stable isotopes of water compared with meteoric water due to photosynthesis and plants transpiration. This process makes possible the detection of exogenous water from wines 18O/16O ratios. Carbon isotopic ratios were used to estimate the supplementary addition of ethanol obtained from C4 plants (sugar cane or corn). This work presents the way in which the isotopic fingerprints (δ13C and δ18O) were used to determine the content of exogenous water from wines and the added supplementary ethanol coming from C4 plants. By using this method, the calculated values obtained for the degree of wine adulteration were in a good agreement with the real exogenous percent of water and ethanol from investigated samples.

  5. Study on the integration of layered water injection technology and subdivision adjustment

    Science.gov (United States)

    Zhang, Yancui

    2018-06-01

    With oil many infillings, thin and poor reservoir exploitation changes gradually to low permeability, thin and poor reservoir development characteristics of multiple layers thickness, low permeability, in the actual development process, the General Department of oil layers of encryption perforation long thin and poor mining, interlayer contradiction more prominent, by conventional layered water injection that can alleviate the contradiction between layers to a certain extent, by the injection interval and other factors can not fundamentally solve the problem, leading to the potential well area key strata or layers is difficult to determine, the layering test and slicing technology is difficult to adapt to the need of tap water control block. This paper through numerical simulation using the conceptual model and the actual block, it has a great influence on the low permeability reservoir of different stratified water permeability combination of permeability technology and application limits, profit and loss balance principle, low oil prices on the lower series of subdivision technical and economic limit, so the reservoir subdivision reorganization, narrow wells mining, reduce the interference between layers, from the maximum fundamental improvement of layered water injection efficiency. At the same time, in order to meet the needs of reservoir subdivision adjustment, subdividing distance with water, a small interlayer wells subdivision technology for further research in the pickup, solved using two ordinary bridge eccentric water regulator with injection of two layers, by throwing exercise distance limit card from the larger problem, the water distribution card size from 7.0m to 1.0m, and the testing efficiency is improved, and provide technical support for further subdivision water injection wells.

  6. Comparison of pore water samplers and cryogenic distillation under laboratory and field conditions for soil water stable isotope analysis.

    Science.gov (United States)

    Thoma, Michael; Frentress, Jay; Tagliavini, Massimo; Scandellari, Francesca

    2018-02-15

    We used pore water samplers (PWS) to sample for isotope analysis (1) only water, (2) soil under laboratory conditions, and (3) soil in the field comparing the results with cryogenic extraction (CE). In (1) and (2), no significant differences between source and water extracted with PWS were detected with a mean absolute difference (MAD) always lower than 2 ‰ for δ 2 H and 1 ‰ for δ 18 O. In (2), CE water was more enriched than PWS-extracted water, with a MAD respect to source water of roughly 8 ‰ for δ 2 H and 4 ‰ for δ 18 O. In (3), PWS water was enriched relative to CE water by 3 ‰ for δ 2 H and 0.9 ‰ for δ 18 O. The latter result may be due to the distinct water portions sampled by the two methods. Large pores, easily sampled by PWS, likely retain recent, and enriched, summer precipitation while small pores, only sampled by CE, possibly retain isotopically depleted water from previous winter precipitation or irrigation inputs. Accuracy and precision were greater for PWS relative to CE. PWS is therefore suggested as viable tool to extract soil water for stable isotope analysis, particularly for soils used in this study (sandy and silty loams).

  7. Studies on determination of stable elements in sea water and organisms

    International Nuclear Information System (INIS)

    Anon.

    1974-01-01

    The existing conditions of stable elements including Co, Zn, Cs, Ce and Eu in sea water were determined by adding radioactive tracers, and determination methods were discussed. 60 Co added to sea water revealed to be kept in solution in 93 per cent of non-filtrated sea water, and in 98 per cent of filtrated sea water. 65 Zn also added to sea water showed to be kept in solution in 97 per cent of both non-filtrated and filtrated sea water. Both elements seemed to exist as particle or ion smaller than 0.45 μ, which solved in sea water. On the other hand, in both Ce and Eu of rare earth elements, about 80 per cent of them presented in the residue, but the treatment of sea water by hydrochroric acid solubilized 80 to 90 per cent of them in filtrated sea water. One of the instrumental analysis, irradiation analysis by nuclear reactor, was applied: each of preconcentration procedure by ion exchange method for Co and Zn in sea water and drying up sample marine organisms to ash content combined with irradiation analysis. Chemical recovery of both 60 Co and 65 Zn in sea water by preconcentration procedure reached more than 95 per cent. As to marine organisms, Co, Zn, and Cs could be determined with only 100 to 200 mg. of ash content obtained from sample marine organisms showing 80 per cent of chemical yield of the carrier through whole the procedure of analysis in almost all the samples. The chemical recovery of Ce and Eu in sea water and marine organisms by the preconcentration procedure reached about 85 per cent, and chemical yield through whole the procedure of analysis was more than 60 per cent. Concentration factor of Co and Zn in fishes and shells, especially that of muscles, obtained by stable elements determination method was almost 10 times that by RI tracer method. The difference of chemical forms between RI tracer and stable isotope affected not only to physiological metabolism but also to food chains. (Kanao, K.)

  8. The analysis of scaling mechanism for water-injection pipe columns in the Daqing Oilfield

    OpenAIRE

    Jing, Guolin; Tang, Shan; Li, Xiaoxiao; Wang, Huaiyuan

    2013-01-01

    Although water-injection in mature reservoirs is a promising low-cost method of enhanced oil recovery (EOR), in the process of development in the oilfield, scale has been produced in water-injection pipe columns. The ability to prevent and control the deposition of scale is critical to the efficient recovery of crude oil from hard environments, as part of the broader discipline of “flow assurance” in the petroleum industry. To this end laboratory-scale deposition tests have been useful to und...

  9. An additive to well injection water for increasing the oil yield

    Energy Technology Data Exchange (ETDEWEB)

    Absov, M.T.; Abutalybov, M.G.; Aslanov, S.M.; Movruzov, E.N.; Musaev, R.A.; Tairov, N.D.

    1979-03-05

    This invention relates to oil production using flooding. The goal of this invention is to increase the oil yield of a producing formation. This is achieved by using a saponin solution as an additive to the water injected into the formation (with related organic substances which are complex organic nitrogen-free compounds from the glycoside group; these substances yield solution that foam easily with an agitation). The use of saponin facilitates good solubility in fresh, sea and formation (alkaline and hard) waters, as well as the absence of sediment formation during dissolution, low solid adsorption, and a significant decrease in the surface water tension on the oil-water boundary. The aqueous saponin solution makes it possible to decrease the production cost of oil, as well as to decrease the development time of the fields and the volume of water injected into the formation and to significantly increase the oil yield.

  10. Can Water-Injected Turbomachines Provide Cost-Effective Emissions and Maintenance Reductions?

    Science.gov (United States)

    Hendricks, Robert C.; Daggett, David L.; Shouse, Dale T.; Roquemore, William M.; Brankovic, Andreja; Ryder, Robert C., Jr.

    2011-01-01

    An investigation has been performed to evaluate the effect of water injection on the performance of the Air Force Research Laboratory (AFRL, Wright-Patterson Air Force Base (WPAFB)) experimental trapped vortex combustor (TVC) over a range of fuel-to-air and water-to-fuel ratios. Performance is characterized by combustor exit quantities: temperature and emissions measurements using rakes, and overall pressure drop, from upstream plenum to combustor exit. Combustor visualization is performed using gray-scale and color still photographs and high-frame-rate videos. A parallel investigation evaluated the performance of a computational fluid dynamics (CFD) tool for the prediction of the reacting flow in a liquid fueled combustor (e.g., TVC) that uses water injection for control of pollutant emissions and turbine inlet temperature. Generally, reasonable agreement is found between data and NO(x) computations. Based on a study assessing the feasibility and performance impact of using water injection on a Boeing 747-400 aircraft to reduce NO(x) emissions during takeoff, retrofitting does not appear to be cost effective; however, an operator of a newly designed engine and airframe might be able to save up to 1.0 percent in operating costs. Other challenges of water injection will be discussed.

  11. Development of seasonal heat storage based on stable supercooling of a sodium acetate water mixture

    DEFF Research Database (Denmark)

    Furbo, Simon; Fan, Jianhua; Andersen, Elsa

    2012-01-01

    A number of heat storage modules for seasonal heat storages based on stable supercooling of a sodium acetate water mixture have been tested by means of experiments in a heat storage test facility. The modules had different volumes and designs. Further, different methods were used to transfer heat...... to and from the sodium acetate water mixture in the modules. By means of the experiments: • The heat exchange capacity rates to and from the sodium acetate water mixture in the heat storage modules were determined for different volume flow rates. • The heat content of the heat storage modules were determined....... • The reliability of the supercooling was elucidated for the heat storage modules for different operation conditions. • The reliability of a cooling method used to start solidification of the supercooled sodium acetate water mixture was elucidated. The method is making use of boiling CO2 in a small tank in good...

  12. Stable annual pattern of water use by Acacia tortilis in Sahelian Africa.

    Science.gov (United States)

    Do, Frederic C; Rocheteau, Alain; Diagne, Amadou L; Goudiaby, Venceslas; Granier, André; Lhomme, Jean-Paul

    2008-01-01

    Water use by mature trees of Acacia tortilis (Forsk.) Hayne ssp. raddiana (Savi) Brenan var. raddiana growing in the northern Sahel was continuously recorded over 4 years. Water use was estimated from xylem sap flow measured by transient heat dissipation. Concurrently, cambial growth, canopy phenology, leaf water potential, climatic conditions and soil water availability (SWA) were monitored. In addition to the variation attributable to interannual variation in rainfall, SWA was increased by irrigation during one wet season. The wet season lasted from July to September, and annual rainfall ranged between 146 and 367 mm. The annual amount and pattern of tree water use were stable from year-to-year despite interannual and seasonal variations in SWA in the upper soil layers. Acacia tortilis transpired readily throughout the year, except for one month during the dry season when defoliation was at a maximum. Maximum water use of about 23 l (dm sapwood area)(-2) day(-1) was recorded at the end of the wet season. While trees retained foliage in the dry season, the decline in water use was modest at around 30%. Variation in predawn leaf water potential indicated that the trees were subject to soil water constraint. The rapid depletion of water in the uppermost soil layers after the wet season implies that there was extensive use of water from deep soil layers. The deep soil profile revealed (1) the existence of living roots at 25 m and (2) that the availability of soil water was low (-1.6 MPa) down to the water table at a depth of 31 m. However, transpiration was recorded at a predawn leaf water potential of -2.0 MPa, indicating that the trees used water from both intermediary soil layers and the water table. During the full canopy stage, mean values of whole-tree hydraulic conductance were similar in the wet and dry seasons. We propose that the stability of water use at the seasonal and annual scales resulted from a combination of features, including an extensive rooting

  13. Stable Water Oxidation in Acid Using Manganese-Modified TiO2 Protective Coatings.

    Science.gov (United States)

    Siddiqi, Georges; Luo, Zhenya; Xie, Yujun; Pan, Zhenhua; Zhu, Qianhong; Röhr, Jason A; Cha, Judy J; Hu, Shu

    2018-06-06

    Accomplishing acid-stable water oxidation is a critical matter for achieving both long-lasting water-splitting devices and other fuel-forming electro- and photocatalytic processes. Because water oxidation releases protons into the local electrolytic environment, it becomes increasingly acidic during device operation, which leads to corrosion of the photoactive component and hence loss in device performance and lifetime. In this work, we show that thin films of manganese-modified titania, (Ti,Mn)O x , topped with an iridium catalyst, can be used in a coating stabilization scheme for acid-stable water oxidation. We achieved a device lifetime of more than 100 h in pH = 0 acid. We successfully grew (Ti,Mn)O x coatings with uniform elemental distributions over a wide range of manganese compositions using atomic layer deposition (ALD), and using X-ray photoelectron spectroscopy, we show that (Ti,Mn)O x films grown in this manner give rise to closer-to-valence-band Fermi levels, which can be further tuned with annealing. In contrast to the normally n-type or intrinsic TiO 2 coatings, annealed (Ti,Mn)O x films can make direct charge transfer to a Fe(CN) 6 3-/4- redox couple dissolved in aqueous electrolytes. Using the Fe(CN) 6 3-/4- redox, we further demonstrated anodic charge transfer through the (Ti,Mn)O x films to high work function metals, such as iridium and gold, which is not previously possible with ALD-grown TiO 2 . We correlated changes in the crystallinity (amorphous to rutile TiO 2 ) and oxidation state (2+ to 3+) of the annealed (Ti,Mn)O x films to their hole conductivity and electrochemical stability in acid. Finally, by combining (Ti,Mn)O x coatings with iridium, an acid-stable water-oxidation anode, using acid-sensitive conductive fluorine-doped tin oxides, was achieved.

  14. Laser Spectroscopic Analysis of Liquid Water Samples for Stable Hydrogen and Oxygen Isotopes

    International Nuclear Information System (INIS)

    2009-01-01

    Stable isotope ratios of hydrogen and oxygen are tracers of choice for water cycle processes in hydrological, atmospheric and ecological studies. The use of isotopes has been limited to some extent because of the relatively high cost of isotope ratio mass spectrometers and the need for specialized operational skills. Here, the results of performance testing of a recently developed laser spectroscopic instrument for measuring stable hydrogen and oxygen isotope ratios of water samples are described, along with a procedure for instrument installation and operation. Over the last four years, the IAEA Water Resources Programme conducted prototype and production model testing of these instruments and this publication is the outcome of those efforts. One of the main missions of the IAEA is to promote the use of peaceful applications of isotope and nuclear methods in Member States and this publication is intended to facilitate the use of laser absorption based instruments for hydrogen and oxygen stable isotope analyses of liquid water samples for hydrological and other studies. The instrument uses off-axis integrated cavity output spectroscopy to measure absolute abundances of 2 HHO, HH 18 O, and HHO via laser absorption. Test results using a number of natural and synthetic water standards and samples with a large range of isotope values demonstrate adequate precision and accuracy (e.g. precisions of 1 per mille for δ 2 H and 0.2 per mille for δ 18 O). The laser instrument has much lower initial and maintenance costs than mass spectrometers and is substantially easier to operate. Thus, these instruments have the potential to bring about a paradigm shift in isotope applications by enabling researchers in all fields to measure isotope ratios by themselves. The appendix contains a detailed procedure for the installation and operation of the instrument. Using the procedure, new users should be able to install the instrument in less than two hours. It also provides step

  15. Investigation of Amourphous Deposits and Potential Corrosion Mechanisms in Offshore Water Injection Systems

    DEFF Research Database (Denmark)

    Eroini, Violette; Oehler, Mike Christian; Graver, Britt Kathrine

    2017-01-01

    Increasing incidence of amorphous deposits in both production and water injection systems has caused considerable problems for offshore oil fields. Amorphous deposits, which are a widely recognized, but often poorly explained phenomenon, are typically comprised of both organic (biological...... or hydrocarbons) and inorganic material, but with compositions that vary considerably. One recurrent form of deposits, found in offshore water injection flowlines and wells, consisting mainly of magnetite as the corrosion product, was further investigated with the objectives of explaining its formation......, composed of both organic and inorganic compounds, has caused concerns within operating assets due to the detrimental effect on production and injection, in addition to challenges with intervention and integrity. The variety of deposits and poor understanding of their nature has led to confusion...

  16. Role of passive valves & devices in poison injection system of advanced heavy water reactor

    International Nuclear Information System (INIS)

    Sapra, M.K.; Kundu, S.; Vijayan, P.K.; Vaze, K.K.; Sinha, R.K.

    2014-01-01

    The Advanced Heavy Water Reactor (AHWR) is a 300 MWe pressure tube type boiling light water (H 2 O) cooled, heavy water (D 2 O) moderated reactor. The reactor design is based on well-proven water reactor technologies and incorporates a number of passive safety features such as natural circulation core cooling; direct in-bundle injection of light water coolant during a Loss of Coolant Accident (LOCA) from Advanced Accumulators and Gravity Driven Water Pool by passive means; Passive Decay Heat Removal using Isolation Condensers, Passive Containment Cooling System and Passive Containment Isolation System. In addition to above, there is another passive safety system named as Passive Poison Injection System (PPIS) which is capable of shutting down the reactor for a prolonged time. It is an additional safety system in AHWR to fulfill the shutdown function in the event of failure of wired shutdown systems i.e. primary and secondary shut down systems of the reactor. When demanded, PPIS injects the liquid poison into the moderator by passive means using passive valves and devices. On increase of main heat transport (MHT) system pressure beyond a predetermined value, a set of rupture disks burst, which in-turn actuate the passive valve. The opening of passive valve initiates inrush of high pressure helium gas into poison tanks to push the poison into the moderator system, thereby shutting down the reactor. This paper primarily deals with design and development of Passive Poison Injection System (PPIS) and its passive valves & devices. Recently, a prototype DN 65 size Poison Injection Passive Valve (PIPV) has been developed for AHWR usage and tested rigorously under simulated conditions. The paper will highlight the role of passive valves & devices in PPIS of AHWR. The design concept and test results of passive valves along with rupture disk performance will also be covered. (author)

  17. Isotopic modeling of water and sodium distribution and exchange kinetics in 7 stable hemodialysis patients

    International Nuclear Information System (INIS)

    Chamoiseau, S.; Bertrou, L.; Pujo, J.M.; Massol, M.

    1988-01-01

    Sequential serum sampling over 24 h. has been performed in 7 hemodialysis patients after simultaneous intra-venous injection of tritiated water and 24 Na. Each time-activity curve fits a biexponential pattern. A compartment analysis leads to describe either a simple but incomplete single compartment model or a much more satisfactory open two-compartment mamillary model featuring 2 intercompartment transfer rate constants k 21 and k 12 , and a loss out of the system, k 01 . These constants can be related to intrabody resistances to sodium and water transfers. Compartment analysis allows a comprehensive quantitated description of the exchange and transfer kinetics of sodium and water throughout the system. Evidence for a sodium reservoir, probably located in bone, can be drawn from the results and leads to propose a strategy for a targetted bone sodium removal [fr

  18. Dew water effects on leaf water using a stable isotope approach

    Science.gov (United States)

    Kim, K.; Lee, X.

    2009-12-01

    The presence of dew is a common meteorological phenomenon in field conditions and takes into account for significant portion of hydrologic processes in terrestrial ecosystems. The isotope composition of leaf water plays an important role in the isotopic water and carbon fluxes between terrestrial plants and the atmosphere. However, the consequence of dew formation in the plant-atmosphere relations has been ignored in many studies. The objective of this study is to improve our understanding of environmental and biological controls on the leaf water in equilibrium with dew water through laboratory experiments. Five species of plants (soybean, corn, sorghum, wheat, cotton) were grown hydroponically with water of a known isotopic content in a greenhouse. On the day of the experiment, they were first moved to ambient environment in full sunlight for at least 6 hr and then into a dark container inside the lab for up to 48 hr in which water vapor isotope ratios, temperature, and humidity were controlled. This arrangement created a step change in the forcing on the plant isotopic exchange. Leaves were sampled prior to the transfer to the dark container and 6 more times every 4 - 12 hr over the experiment. Humidity inside the container was saturated to mimic dew events in field conditions. Water from the leaf samples was extracted by a vacuum line and was analyzed for both δD and δ18O. The dataset will allow us to evaluate leaf water isotopic theories by exploring the transitions of the isotopic ratio of leaf water in response to the step change. Specifically, we are interested in whether the stomatal opening is an effective pathway for gaseous exchange in total darkness and how the transitional behaviors of the isotopic ratio of leaf water differ between the C3 and C4 photosynthesis pathways.

  19. Test facility for fast gas injections into a vessel filled with water

    International Nuclear Information System (INIS)

    Wilhelm, D.; Kirstahler, M.

    1987-11-01

    The Fast Gas Injection Facility (SGI) was set up to study the hydrodynamics during the expansion of a gas bubble into a vessel filled with water. The gas stored in a pressure vessel expands against gravity through a circular duct into a large cylindrical vessel partly with water. This report covers the description of the test facility and the data acquisition. Results of the first test series are added. (orig.) [de

  20. Method for reducing heat loss during injection of hot water into an oil stratum

    Energy Technology Data Exchange (ETDEWEB)

    Evgenev, A E; Kalashnikov, V N; Raiskii, Yu D

    1968-07-01

    A method is described for reduction of heat loss during the injection of hot water into an oil stratum. During the transportation of the hot water to the face of the bore holes, it has high-molecular polymers added to it. The high-molecular polymer may be guanidine or polyoxyethylene in the quantity of 0.01 to 0.03% by wt.

  1. Partitioning evapotranspiration fluxes with water stable isotopic measurements: from the lab to the field

    Science.gov (United States)

    Quade, M. E.; Brueggemann, N.; Graf, A.; Rothfuss, Y.

    2017-12-01

    Water stable isotopes are powerful tools for partitioning net into raw water fluxes such as evapotranspiration (ET) into soil evaporation (E) and plant transpiration (T). The isotopic methodology for ET partitioning is based on the fact that E and T have distinct water stable isotopic compositions, which in turn relies on the fact that each flux is differently affected by isotopic kinetic effects. An important work to be performed in parallel to field measurements is to better characterize these kinetic effects in the laboratory under controlled conditions. A soil evaporation laboratory experiment was conducted to retrieve characteristic values of the kinetic fractionation factor (αK) under varying soil and atmospheric water conditions. For this we used a combined soil and atmosphere column to monitor the soil and atmospheric water isotopic composition profiles at a high temporal and vertical resolution in a nondestructive manner by combining micro-porous membranes and laser spectroscopy. αK was calculated by using a well-known isotopic evaporation model in an inverse mode with the isotopic composition of E as one input variable, which was determined using a micro-Keeling regression plot. Knowledge on αK was further used in the field (Selhausen, North Rhine-Westphalia, Germany) to partition ET of catch crops and sugar beet (Beta vulgaris) during one growing season. Soil and atmospheric water isotopic profiles were measured automatically across depths and heights following a similar modus operandi as in the laboratory experiment. Additionally, a newly developed continuously moving elevator was used to obtain water vapor isotopic composition profiles with a high vertical resolution between soil surface, plant canopy and atmosphere. Finally, soil and plant samples were collected destructively to provide a comparison with the traditional isotopic methods. Our results illustrate the changing proportions of T and E along the growing season and demonstrate the

  2. Stable Water Use Efficiency under Climate Change of Three Sympatric Conifer Species at the Alpine Treeline.

    Science.gov (United States)

    Wieser, Gerhard; Oberhuber, Walter; Gruber, Andreas; Leo, Marco; Matyssek, Rainer; Grams, Thorsten Erhard Edgar

    2016-01-01

    The ability of treeline associated conifers in the Central Alps to cope with recent climate warming and increasing CO2 concentration is still poorly understood. We determined tree ring stable carbon and oxygen isotope ratios of Pinus cembra, Picea abies, and Larix decidua trees from 1975 to 2010. Stable isotope ratios were compared with leaf level gas exchange measurements carried out in situ between 1979 and 2007. Results indicate that tree ring derived intrinsic water-use efficiency (iWUE) of P. cembra, P. abies and L. decidua remained constant during the last 36 years despite climate warming and rising atmospheric CO2. Temporal patterns in Δ(13)C and Δ(18)O mirrored leaf level gas exchange assessments, suggesting parallel increases of CO2-fixation and stomatal conductance of treeline conifer species. As at the study site soil water availability was not a limiting factor iWUE remained largely stable throughout the study period. The stability in iWUE was accompanied by an increase in basal area increment (BAI) suggesting that treeline trees benefit from both recent climate warming and CO2 fertilization. Finally, our results suggest that iWUE may not change species composition at treeline in the Austrian Alps due to similar ecophysiological responses to climatic changes of the three sympatric study species.

  3. Stable water use efficiency under climate change of three sympatric conifer species at the Alpine treeline

    Directory of Open Access Journals (Sweden)

    Gerhard eWieser

    2016-06-01

    Full Text Available The ability of treeline associated conifers in the Central Alps to cope with recent climate warming and increasing CO2 concentration is still poorly understood. We determined tree ring stable carbon and oxygen isotope ratios of Pinus cembra, Picea abies and Larix decidua trees from 1975-2010. Stable isotope ratios were compared with leaf level gas exchange measurements carried out in situ between 1979 and 2007. Results indicate that tree ring derived intrinsic water-use efficiency (iWUE of P. cembra, P. abies and L. decidua remained constant during the last 36 years despite climate warming and rising atmospheric CO2. Temporal patterns in Δ13C and Δ18O mirrored leaf level gas exchange assessments, suggesting parallel increases of CO2-fixation and stomatal conductance of treeline conifer species. As at the study site soil water availability was not a limiting factor iWUE remained largely stable throughout the study period. The stability in iWUE was accompanied by an increase in basal area increment (BAI suggesting that treeline trees benefit from both recent climate warming and CO2 fertilization. Finally, our results suggest that iWUE may not change species composition at treeline in the Austrian Alps due to similar ecophysiological responses to climatic changes of the three sympatric study species.

  4. Constraining water uptake depths in semiarid environments using water stable isotopes

    Science.gov (United States)

    Beyer, Matthias; Königer, Paul; Himmelsbach, Thomas

    2017-04-01

    The biophysical process of transpiration recently received increased attention by ecohydrologists as it has been proven the largest flux of the global water balance. However, fundamental aspects related to the questions how and from which sources plants receive their water are not fully understood. Especially the process of plant water uptake from deeper soil and its impact on the water balance requires increased scientific effort. In this study we combined tracer experiments with the analysis of natural isotopic compositions in order to: i) derive a suitable site-specific root water uptake distribution for hydrological modeling; ii) find indicators for groundwater use by specific plants; and iii) evaluate the importance of deep unsaturated zone water uptake using HYDRUS 1D. The bayesian mixing model MixSIAR was applied at a semiarid site with a deep unsaturated zone in northern Namibia in order to identify source water contributions of the most abundant species (A.erioloba, B.plurijuga, C.collinum, S.luebertii and T.sericea). In addition, a previously developed method for the investigation of root water uptake depths based on deuterium labeling (2H2O) at specific depths (0.5 to 4 m) and monitoring of tracer uptake by plants was carried out with a focus on the deeper unsaturated zone. With the experimental results a root water uptake distribution for the lateral root zone was derived which allows to constrain the source water contributions estimated with MixSIAR. Finally, a HYDRUS 1D model was established and unsaturated zone water transport was evaluated. The analysis of the natural isotopic compositions reveals a significant contribution of groundwater (median: 48%) to the isotopic composition of A.erioloba at the end of the dry season indicating the presence of deep tap roots for a number of individuals. All other investigated species obtain their water from the shallow (median: 22%) or deeper (median: 62%) unsaturated zone at this time of the year. The water

  5. An experimental study on tissue damage following subcutaneous injection of water soluble contrast media

    International Nuclear Information System (INIS)

    Kim, Seung Hyup; Park, Jae Hyung; Kang, Heung Sik; Kim, Chu Wan; Han, Man Chung; Kim, Yong Il

    1989-01-01

    The water soluble contrast media cause tissue necrosis infrequently by extravasation during intravenous injection in various radiological examinations. However, it has not been well documented that what kind and what concentration of contrast media can cause tissue necrosis. And also, the mechanism of tissue necrosis by extravasated contrast media has not been well known. The purpose of this experimental study was to evaluate the frequency and severity of tissue damage following subcutaneous injection of various water soluble contrast media to investigate the characteristics of the contrast media acting on the tissue damage, and to provide the basic data for the clinical application. Meglumine ioxithalamate,sodium and meglumine ioxithalamate, iopromide, iopamidol, ioxaglate,meglumine diatrizoate and sodium diatrizoate of various iodine content and osmolality were injected into subcutaneous tissue of the dorsum of 970 feet of 485 rats. The tissue reaction of injection sites were grossly examined with period from 1 day to 8 weeks after the injection. Representative gross changes were correlated with histologic findings. The results were as follows; 1. The basic tissue damage by extravasated contrast media was acute and chronic inflammatory reaction of the soft tissue with subsequent progress into the hemorrhagic and necrotizing lesion. 2. Lager volume of contrast media caused more severe tissue damage. 3. Contrast media of higher osmolality caused more severe tissue damage. 4. At same osmolality, contrast media of higher iodine content caused more severe tissue damage

  6. Performance of single cylinder, direct injection Diesel engine using water fuel emulsions

    International Nuclear Information System (INIS)

    Abu-Zaid, M.

    2004-01-01

    A single cylinder Diesel engine study of water-in-Diesel emulsions was conducted to investigate the effect of water emulsification on the engine performance and gases exhaust temperature. Emulsified Diesel fuels of 0, 5, 10, 15 and 20 water/Diesel ratios by volume, were used in a single cylinder, direct injection Diesel engine, operating at 1200-3300 rpm. The results indicate that the addition of water in the form of emulsion improves combustion efficiency. The engine torque, power and brake thermal efficiency increase as the water percentage in the emulsion increases. The average increase in the brake thermal efficiency for 20% water emulsion is approximately 3.5% over the use of Diesel for the engine speed range studied. The proper brake specific fuel consumption and gases exhaust temperature decrease as the percentage of water in the emulsion increases

  7. Stable chlorine isotope compositions in waters from the Kusatsu-Shirane volcanic system, Japan

    International Nuclear Information System (INIS)

    Musashi, Masaaki

    1999-01-01

    Chlorine stable isotope compositions (δ 37 Cl, per-mil: per mille, vs. a standard sea water, SMOC) of six waters collected in 1984 from Kusatsu area (three springs), Manza area (two springs), and a crater lake Yugama, in the Kusatsu-Shirane volcanic system, Japan, are analysed with the overall precision of 0.12 per mille (2σ). The δ 37 Cl values range between -0.05 per mille and +0.20 per mille (the mean, +0.04 per mille), and are nearly equal to that of the sea water. And the values are not significantly different between the Kusatsu and Manza areas, although their thermal features have a strong chemical and geological variations with a geographical separation of over 8 km between the two areas. (author)

  8. The Effect of Temperature and Injection Rate during Water Flooding Using Carbonate Core Samples: An Experimental Approach

    Directory of Open Access Journals (Sweden)

    Yaser Ahmadi

    2016-10-01

    Full Text Available In many reservoirs, after water flooding, a large volume of oil is still left behind. Hot water injection is the most basic type of thermal recovery which increase recovery by improved sweep efficiency and thermal expansion of crude.In the present work, the effects of injection rate and the temperature of the injected water were surveyed by using core flooding apparatus. Water flooding was performed at different rates (0.2, 0.3, and 0.4 cc/min and temperatures (20 and 90 °C, and the reservoir temperature was about 63 °C. Oil recovery during hot water injection was more than water injection. Moreover, it was concluded that at injection rates of 0.2, 0.3, and 0.4 cc/min breakthrough time in hot water injection occurred 10 min later in comparison to water injection. The results showed that higher oil recovery and longer breakthrough time were obtained as a result of reducing injection rate. In the first 50 minutes, the oil recovery at injection rates of 0.2, 0.3 and 0.4 cc/min was 27.5, 34, and 46% respectively. It was found that at the beginning of injection, thermal and non-thermal injection recovery factors are approximately equal. Moreover, according to the results, recovery factor at the lowest rate in hot water (T=90 °C and q=0.2 cc/min is the best condition to obtain the highest recovery.

  9. Optical trapping and binding of particles in an optofluidic stable Fabry-Pérot resonator with single-sided injection.

    Science.gov (United States)

    Gaber, Noha; Malak, Maurine; Marty, Frédéric; Angelescu, Dan E; Richalot, Elodie; Bourouina, Tarik

    2014-07-07

    In this article, microparticles are manipulated inside an optofluidic Fabry-Pérot cylindrical cavity embedding a fluidic capillary tube, taking advantage of field enhancement and multiple reflections within the optically-resonant cavity. This enables trapping of suspended particles with single-side injection of light and with low optical power. A Hermite-Gaussian standing wave is developed inside the cavity, forming trapping spots at the locations of the electromagnetic field maxima with a strong intensity gradient. The particles get arranged in a pattern related to the mechanism affecting them: either optical trapping or optical binding. This is proven to eventually translate into either an axial one dimensional (1D) particle array or a cluster of particles. Numerical simulations are performed to model the field distributions inside the cavity allowing a behavioral understanding of the phenomena involved in each case.

  10. Accident tolerant high-pressure helium injection system concept for light water reactors

    International Nuclear Information System (INIS)

    Massey, Caleb; Miller, James; Vasudevamurthy, Gokul

    2016-01-01

    Highlights: • Potential helium injection strategy is proposed for LWR accident scenarios. • Multiple injection sites are proposed for current LWR designs. • Proof-of-concept experimentation illustrates potential helium injection benefits. • Computational studies show an increase in pressure vessel blowdown time. • Current LOCA codes have the capability to include helium for feasibility calculations. - Abstract: While the design of advanced accident-tolerant fuels and structural materials continues to remain the primary focus of much research and development pertaining to the integrity of nuclear systems, there is a need for a more immediate, simple, and practical improvement in the severe accident response of current emergency core cooling systems. Current blowdown and reflood methodologies under accident conditions still allow peak cladding temperatures to approach design limits and detrimentally affect the integrity of core components. A high-pressure helium injection concept is presented to enhance accident tolerance by increasing operator response time while maintaining lower peak cladding temperatures under design basis and beyond design basis scenarios. Multiple injection sites are proposed that can be adapted to current light water reactor designs to minimize the need for new infrastructure, and concept feasibility has been investigated through a combination of proof-of-concept experimentation and computational modeling. Proof-of-concept experiments show promising cooling potential using a high-pressure helium injection concept, while the developed choked-flow model shows core depressurization changes with added helium injection. Though the high-pressure helium injection concept shows promise, future research into the evaluation of system feasibility and economics are needed.Classification: L. Safety and risk analysis

  11. Stable water isotopic composition of the Antarctic subglacial Lake Vostok: implications for understanding the lake's hydrology.

    Science.gov (United States)

    Ekaykin, Alexey A; Lipenkov, Vladimir Y; Kozachek, Anna V; Vladimirova, Diana O

    2016-01-01

    We estimated the stable isotopic composition of water from the subglacial Lake Vostok using two different sets of samples: (1) water frozen on the drill bit immediately after the first lake unsealing and (2) water frozen in the borehole after the unsealing and re-drilled one year later. The most reliable values of the water isotopic composition are: -59.0 ± 0.3 ‰ for oxygen-18, -455 ± 1 ‰ for deuterium and 17 ± 1 ‰ for d-excess. This result is also confirmed by the modelling of isotopic transformations in the water which froze in the borehole, and by a laboratory experiment simulating this process. A comparison of the newly obtained water isotopic composition with that of the lake ice (-56.2 ‰ for oxygen-18, -442.4 ‰ for deuterium and 7.2 ‰ for d-excess) leads to the conclusion that the lake ice is very likely formed in isotopic equilibrium with water. In turn, this means that ice is formed by a slow freezing without formation of frazil ice crystals and/or water pockets. This conclusion agrees well with the observed physical and chemical properties of the lake's accreted ice. However, our estimate of the water's isotopic composition is only valid for the upper water layer and may not be representative for the deeper layers of the lake, so further investigations are required.

  12. Study of the Effect of Clay Particles on Low Salinity Water Injection in Sandstone Reservoirs

    Directory of Open Access Journals (Sweden)

    Sina Rezaei Gomari

    2017-03-01

    Full Text Available The need for optimal recovery of crude oil from sandstone and carbonate reservoirs around the world has never been greater for the petroleum industry. Water-flooding has been applied to the supplement primary depletion process or as a separate secondary recovery method. Low salinity water injection is a relatively new method that involves injecting low salinity brines at high pressure similar to conventional water-flooding techniques, in order to recover crude oil. The effectiveness of low salinity water injection in sandstone reservoirs depends on a number of parameters such as reservoir temperature, pressure, type of clay particle and salinity of injected brine. Clay particles present on reservoir rock surfaces adsorb polar components of oil and modify wettability of sandstone rocks to the oil-wet state, which is accountable for the reduced recovery rates by conventional water-flooding. The extent of wettability alteration caused by three low salinity brines on oil-wet sandstone samples containing varying clay content (15% or 30% and type of clay (kaolinite/montmorillonite were analyzed in the laboratory experiment. Contact angles of mica powder and clay mixture (kaolinite/montmorillonite modified with crude oil were measured before and after injection with three low salinity sodium chloride brines. The effect of temperature was also analyzed for each sample. The results of the experiment indicate that samples with kaolinite clay tend to produce higher contact angles than samples with montmorillonite clay when modified with crude oil. The highest degree or extent of wettability alteration from oil-wet to intermediate-wet state upon injection with low salinity brines was observed for samples injected with brine having salinity concentration of 2000 ppm. The increase in temperature tends to produce contact angles values lying in the higher end of the intermediate-wet range (75°–115° for samples treated at 50 °C, while their corresponding

  13. Geochemical and hydrological characterization of shallow aquifer water following a nearby deep CO2 injection in Wellington, Kansas

    Science.gov (United States)

    Datta, S.; Andree, I.; Johannesson, K. H.; Kempton, P. D.; Barker, R.; Birdie, T. R.; Watney, W. L.

    2017-12-01

    Salinization or CO2 leakage from local Enhanced Oil Recovery (EOR) projects has become a possible source for contamination and water quality degradation for local irrigation or potable well users in Wellington, Kansas. Shallow domestic and monitoring wells, as well as surface water samples collected from the site, were analyzed for a wide array of geochemical proxies including major and trace ions, rare earth elements (REE), stable isotopes, dissolved organic carbon and dissolved hydrocarbons; these analytes were employed as geotracers to understand the extent of hydrologic continuity throughout the Paleozoic stratigraphic section. Previous research by Barker et al. (2012) laid the foundation through a mineralogical and geochemical investigation of the Arbuckle injection zone and assessment of overlying caprock integrity, which led to the conclusion that the 4,910-5,050' interval will safely sequester CO2 with high confidence of a low leakage potential. EOR operations using CO2 as the injectant into the Mississippian 3,677-3,706' interval was initiated in Jan 2016. Two groundwater sampling events were conducted to investigate any temporal changes in the surface and subsurface waters. Dissolved (Ca+Mg)/Na and Na/Cl mass ratio values of two domestic wells and one monitoring well ranged from 0.67 to 2.01 and 0.19 to 0.39, respectively, whereas a nearby Mississippian oil well had values of 0.20 and 0.62, respectively . δ18O and δ2H ranged from -4.74 to -5.41 ‰VSMOW and -31.4 to -34.3 ‰VSMOW, respectively, among the domestic wells and shallowest monitoring well. Conservative ion relationships in drill-stem-test waters from Arbuckle and Mississippian injection zones displayed significant variability, indicating limited vertical hydrologic communication. Total aquifer connectivity is inconclusive based on the provided data; however, a paleoterrace and incised valley within the study site are thought to be connected through a Mississippian salt plume migration

  14. Effect of water injection on nitric oxide emissions of a gas turbine combustor burning natural gas fuel

    Science.gov (United States)

    Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

    1973-01-01

    The effect of direct water injection on the exhaust gas emissions of a turbojet combustor burning natural gas fuel was investigated. The results are compared with the results from similar tests using ASTM Jet-A fuel. Increasing water injection decreased the emissions of oxides of nitrogen (NOX) and increased the emissions of carbon monoxide and unburned hydrocarbons. The greatest percentage decrease in NOX with increasing water injection was at the lowest inlet-air temperature tested. The effect of increasing inlet-air temperature was to decrease the effect of the water injection. The reduction in NOX due to water injection was almost identical to the results obtained with Jet-A fuel. However, the emission indices of unburned hydrocarbons, carbon monoxide, and percentage nitric oxide in NOX were not.

  15. Zinc injection on the EDF pressurized light water reactors. Current results and operating experience feedback

    International Nuclear Information System (INIS)

    Piana, Olivier; Duval, Arnaud; Moleiro, Edgar; Benfarah, Moez; Bretelle, Jean-Luc; Chaigne, Guy

    2014-01-01

    Nowadays, zinc injection, as well as pH management and hydrogen control, is increasingly considered as an essential element of PWR Primary Water Chemistry worldwide. After a first implementation of zinc injection at Bugey 2 since 2004 and Bugey 4 since 2006, EDF decided to extend this practice, which constitutes a modification of primary circuit chemical conditioning, to other units of its fleet. Currently, 15 among the 58 reactors of the French fleet are injecting depleted zinc acetate into the primary coolant water. Three main goals were identified at the beginning of this program. Indeed, the expected benefits of zinc injection were: Reduction of the rate of generalized corrosion and mitigation of stress corrosion cracking initiation on nickel based alloys (Material goal). Curative or preventive reduction of radiation sources to which workers are exposed (Radiation fields' goal). Mitigation of the AOA or CIPS risks by reduction of corrosion products releases and mitigation of crud deposition (Fuel protection goal). To monitor the zinc addition, EDF has defined a complete survey program concerning: chemistry and radiochemistry responses (primary coolant monitoring of corrosion and fission products and calculation of zinc injected, zinc removed and zinc incorporated in RCS surfaces) ; radiation fields (dose rates and deposited activities measurements) ; materials (statistical analysis of SG tube cracks) ; fuel (oxide thickness measurements and visual exams) ; effluents (corrosion products releases and isotopic distribution follow up) ; wastes (radiochemical characterization of filters). This paper will detail the present results of this monitoring program. It appears that the expected benefits of zinc injection have yet to be fully realized; further operating experience will be required in order to fully evaluate its impact. (author)

  16. Interactions between surface waters in King George Island, Antarctica - a stable isotope perspective

    Science.gov (United States)

    Perşoiu, Aurel; Bădăluşă, Carmen

    2017-04-01

    In this paper we present a first study of the isotopic composition of surface waters in the southern peninsulas (Barton, Fildes, Weaver and Potter) of King George Island, Antarctica. We have collected > 200 samples of snow and snowmelt, water (lake, river and spring), ice (glacier ice and permafrost) from the four peninsulas in February 2016 and analyzed them for their oxygen and hydrogen stable isotopic composition. Samples from lake water (50+) indicate a clear west-east depletion trend, suggesting a rain-out process as air masses are moving westward (and are progressively depleted in heavy isotopes) from their origin in the Drake Passage. In both Fildes and Barton Peninsulas, permafrost samples have the heaviest isotopic composition, most probably due to preferential incorporation of heavy isotopes in the ice during freezing (and no fractionation during melting). As permafrost melts, the resulting water mixes with isotopically lighter infiltrated snowmelt, and thus the groundwater has a lower isotopic composition. Further, lake and river (the later fed by lakes) water has the lightest isotopic composition, being derived mostly from the melting of light snow and glacier ice. It seems feasible to separate isotopically water in lakes/rivers (largely fed by melting multi-year glaciers and snow) and water from melting of snow/ground ice This preliminary study suggests that it is possible to separate various water sources in the southern peninsulas of King George Island, and this separation could be used to study permafrost degradation, as well as feeding and migration patterns in the bird fauna, with implications for protection purposes. Acknowledgments. The National Institute of Research and Development for Biological Sciences (Bucharest, Romania) and the Korean polar institute financially supported fieldwork in King George Island. We thank the personal at King Sejong (South Korea), Belingshaussen (Russia) and Carlini (Argentina) stations in King George Island for

  17. Bacterial diversity in water injection systems of Brazilian offshore oil platforms.

    Science.gov (United States)

    Korenblum, Elisa; Valoni, Erika; Penna, Mônica; Seldin, Lucy

    2010-01-01

    Biogenic souring and microbial-influenced corrosion is a common scenario in water-flooded petroleum reservoirs. Water injection systems are continuously treated to control bacterial contamination, but some bacteria that cause souring and corrosion can persist even after different treatments have been applied. Our aim was to increase our knowledge of the bacterial communities that persist in the water injection systems of three offshore oil platforms in Brazil. To achieve this goal, we used a culture-independent molecular approach (16S ribosomal RNA gene clone libraries) to analyze seawater samples that had been subjected to different treatments. Phylogenetic analyses revealed that the bacterial communities from the different platforms were taxonomically different. A predominance of bacterial clones affiliated with Gammaproteobacteria, mostly belonging to the genus Marinobacter (60.7%), were observed in the platform A samples. Clones from platform B were mainly related to the genera Colwellia (37.9%) and Achromobacter (24.6%), whereas clones obtained from platform C were all related to unclassified bacteria. Canonical correspondence analyses showed that different treatments such as chlorination, deoxygenation, and biocide addition did not significantly influence the bacterial diversity in the platforms studied. Our results demonstrated that the injection water used in secondary oil recovery procedures contained potentially hazardous bacteria, which may ultimately cause souring and corrosion.

  18. Chaotic behavior of water column oscillator simulating pressure balanced injection system in passive safety reactor

    International Nuclear Information System (INIS)

    Morimoto, Y.; Madarame, H.; Okamoto, K.

    2001-01-01

    Japan Atomic Energy Research Institute (JAERI) proposed a passive safety reactor called the System-integrated Pressurized Water Reactor (SPWR). In a loss of coolant accident, the Pressurizing Line (PL) and the Injection Line (IL) are passively opened. Vapor generated by residual heat pushes down the water level in the Reactor Vessel (RV). When the level is lower than the inlet of the PL, the vapor is ejected into the Containment Vessel (CV) through the PL. Then boronized water in the CV is injected into the RV through the IL by the static head. In an experiment using a simple apparatus, gas ejection and water injection were found to occur alternately under certain conditions. The gas ejection interval was observed to fluctuate considerably. Though stochastic noise affected the interval, the experimental results suggested that the large fluctuation was produced by an inherent character in the system. A set of piecewise linear differential equations was derived to describe the experimental result. The large fluctuation was reproduced in the analytical solution. Thus it was shown to occur even in a deterministic system without any source of stochastic noise. Though the derived equations simulated the experiment well, they had ten independent parameters governing the behavior of the solution. There appeared chaotic features and bifurcation, but the analytical model was too complicated to examine the features and mechanism of bifurcation. In this study, a new simple model is proposed which consists of a set of piecewise linear ordinary differential equations with only four independent parameters. (authors)

  19. Mass spectrometric method for the determination of the stable isotopic content of nitrous oxide by the technique of direct injection

    International Nuclear Information System (INIS)

    Rahn, T.; Wahlen, M.

    2002-01-01

    A method for the direct isotopic analysis of N 2 O has been developed for VG-Prism H dynamic dual inlet stable isotope mass spectrometer. Tests have shown extreme sensitivity to contamination by carbon dioxide with a dependence of 6.8 per mille per % CO 2 for δ 15 N and 12.4 per mille per % CO 2 for δ 18 O. Trace amounts of CO 2 have proven difficult to eliminate, particularly for small sample sizes. In order to ensure accurate analyses an indicator of CO 2 contamination must be monitored and corrections applied when necessary. We have found that ions with mass to charge ratios of 12 and 22 are excellent proxies for CO 2 contamination. Empirical relationships between these indicator species and CO 2 contamination are documented which allow for corrections to be applied to raw data. Additional corrections required due to the presence of isobaric molecules containing 17 O are described. Issues of standardization are discussed and sample handling procedures described. Finally, these methods and corrections are applied to a suite of stratospheric air samples. (author)

  20. Evaluation of an accident management strategy of emergency water injection using fire engines in a typical pressurized water reactor

    Directory of Open Access Journals (Sweden)

    Soo-Yong Park

    2015-10-01

    Full Text Available Following the Fukushima accident, a special safety inspection was conducted in Korea. The inspection results show that Korean nuclear power plants have no imminent risk for expected maximum potential earthquake or coastal flooding. However long- and short-term safety improvements do need to be implemented. One of the measures to increase the mitigation capability during a prolonged station blackout (SBO accident is installing injection flow paths to provide emergency cooling water of external sources using fire engines to the steam generators or reactor cooling systems. This paper illustrates an evaluation of the effectiveness of external cooling water injection strategies using fire trucks during a potential extended SBO accident in a 1,000 MWe pressurized water reactor. With regard to the effectiveness of external cooling water injection strategies using fire engines, the strategies are judged to be very feasible for a long-term SBO, but are not likely to be effective for a short-term SBO.

  1. Stable solar-driven oxidation of water by semiconducting photoanodes protected by transparent catalytic nickel oxide films

    KAUST Repository

    Sun, Ke; Saadi, Fadl H.; Lichterman, Michael F.; Hale, William G.; Wang, Hsinping; Zhou, Xinghao; Plymale, Noah T.; Omelchenko, Stefan T.; He, Jr-Hau; Papadantonakis, Kimberly M.; Brunschwig, Bruce S.; Lewis, Nathan S.

    2015-01-01

    Reactively sputtered nickel oxide (NiOx) films provide transparent, antireflective, electrically conductive, chemically stable coatings that also are highly active electrocatalysts for the oxidation of water to O2(g). These NiOx coatings provide

  2. Cerebral water and ion balance remains stable when humans are exposed to acute hypoxic exercise

    DEFF Research Database (Denmark)

    Avnstorp, Magnus B; Rasmussen, Peter; Brassard, Patrice

    2015-01-01

    both circumstances. No cerebral net exchange of Na(+) or K(+) was evident. Likewise, no significant net-exchange of water over the brain was demonstrated and the arterial and jugular venous hemoglobin concentrations were similar. CONCLUSION: Challenging exercise in hypoxia for 30 min affected muscle......Avnstorp, Magnus B., Peter Rasmussen, Patrice Brassard, Thomas Seifert, Morten Overgaard, Peter Krustrup, Niels H. Secher, and Nikolai B. Nordsborg. Cerebral water and ion balance remains stable when humans are exposed to acute hypoxic exercise. High Alt Med Biol 16:000-000, 2015.-Background...... intense exercise is carried out in hypoxia and monitored the influence of muscle metabolism for changes in arterial variables. METHODS: On two separate days, in random order, 30 min cycling exercise was performed in either hypoxia (10% O2) or normoxia at an intensity that was exhaustive in the hypoxic...

  3. Toxicity of methylmercury injected into eggs when dissolved in water versus corn oil

    Science.gov (United States)

    Heinz, G.H.; Hoffman, D.J.; Klimstra, J.D.; Stebbins, K.R.; Kondrad, S.L.

    2011-01-01

    In a previous study, the embryotoxicity of methylmercury dissolved in corn oil was compared among 26 species of birds. Corn oil is not soluble in the water-based matrix that constitutes the albumen of an egg. To determine whether the use of corn oil limited the usefulness of this earlier study, a comparison was made of the embryotoxicity of methylmercury dissolved in corn oil versus water. Mallard (Anas platyrhynchos) and chicken (Gallus gallus) eggs were injected with methylmercury chloride dissolved in corn oil or water to achieve concentrations of 0, 0.2, 0.4, 0.8, and 1.6??g/g mercury in the egg on a wet weight basis. Hatching success at each dose of mercury was compared between the two solvents. For mallards, 16.4% of the eggs injected with 1.6??g/g mercury dissolved in water hatched, which was statistically lower than the 37.6% hatch rate of eggs injected with 1.6??g/g mercury dissolved in corn oil, but no differences in hatching success were observed between corn oil and water at any of the other doses. With chicken eggs, no significant differences occurred in percentage hatch of eggs between corn oil and water at any of the mercury doses. Methylmercury dissolved in corn oil seems to have a toxicity to avian embryos similar to that of does methylmercury dissolved in water. Consequently, the results from the earlier study that described the toxicity of methylmercury dissolved in corn oil to avian embryos were probably not compromised by the use of corn oil as a solvent. ?? 2011 SETAC.

  4. Improved process for the injection of water for secondary recovery of petroleum

    Energy Technology Data Exchange (ETDEWEB)

    1967-07-24

    In this process for the secondary recovery of petroleum from the formation, an aqueous displacing medium is injected through an injection well in communication with the formation. In this aqueous medium, a polymer is dissolved and the petroleum is thus displaced toward a producing well also in communication with the formation. The polymer is a liquid organic polymer, substantially linear, water-soluble, and having a resistance characteristic of at least 1.5. The polymer is dissolved in water in sufficient quantity such that the viscosity of the displacing medium is 0.5-15% of the viscosity of the crude oil to be displaced. The displacing medium is substantially free of molecular oxygen.

  5. Contingency power for small turboshaft engines using water injection into turbine cooling air

    Science.gov (United States)

    Biesiadny, Thomas J.; Berger, Brett; Klann, Gary A.; Clark, David A.

    1987-01-01

    Because of one engine inoperative requirements, together with hot-gas reingestion and hot day, high altitude takeoff situations, power augmentation for multiengine rotorcraft has always been of critical interest. However, power augmentation using overtemperature at the turbine inlet will shorten turbine life unless a method of limiting thermal and mechanical stresses is found. A possible solution involves allowing the turbine inlet temperature to rise to augment power while injecting water into the turbine cooling air to limit hot-section metal temperatures. An experimental water injection device was installed in an engine and successfully tested. Although concern for unprotected subcomponents in the engine hot section prevented demonstration of the technique's maximum potential, it was still possible to demonstrate increases in power while maintaining nearly constant turbine rotor blade temperature.

  6. Contingency power for a small turboshaft engine by using water injection into turbine cooling air

    Science.gov (United States)

    Biesiadny, Thomas J.; Klann, Gary A.

    1992-01-01

    Because of one-engine-inoperative (OEI) requirements, together with hot-gas reingestion and hot-day, high-altitude take-off situations, power augmentation for multiengine rotorcraft has always been of critical interest. However, power augmentation by using overtemperature at the turbine inlet will shorten turbine life unless a method of limiting thermal and mechanical stress is found. A possible solution involves allowing the turbine inlet temperature to rise to augment power while injecting water into the turbine cooling air to limit hot-section metal temperatures. An experimental water injection device was installed in an engine and successfully tested. Although concern for unprotected subcomponents in the engine hot section prevented demonstration of the technique's maximum potential, it was still possible to demonstrate increases in power while maintaining nearly constant turbine rotor blade temperature.

  7. [Research advances in identifying nitrate pollution sources of water environment by using nitrogen and oxygen stable isotopes].

    Science.gov (United States)

    Mao, Wei; Liang, Zhi-wei; Li, Wei; Zhu, Yao; Yanng, Mu-yi; Jia, Chao-jie

    2013-04-01

    Water body' s nitrate pollution has become a common and severe environmental problem. In order to ensure human health and water environment benign evolution, it is of great importance to effectively identify the nitrate pollution sources of water body. Because of the discrepant composition of nitrogen and oxygen stable isotopes in different sources of nitrate in water body, nitrogen and oxygen stable isotopes can be used to identify the nitrate pollution sources of water environment. This paper introduced the fractionation factors of nitrogen and oxygen stable isotopes in the main processes of nitrogen cycling and the composition of these stable isotopes in main nitrate sources, compared the advantages and disadvantages of five pre-treatment methods for analyzing the nitrogen and oxygen isotopes in nitrate, and summarized the research advances in this aspect into three stages, i. e. , using nitrogen stable isotope alone, using nitrogen and oxygen stable isotopes simultaneously, and combining with mathematical models. The future research directions regarding the nitrate pollution sources identification of water environment were also discussed.

  8. Influence of capillary forces on water injection into hot rock, saturated with superheated vapour

    Energy Technology Data Exchange (ETDEWEB)

    Tsypkin, G.G. [Institute for Problems in Mechanics, RAS, Vernadskogo Ave. 101, 119420 Moscow (Russian Federation); Calore, C. [Istituto di Geoscienze e Georisorse - CNR, Sezione di Firenze, via La Pira 4, 50121 Florence (Italy)

    2007-07-15

    The results of a theoretical study and numerical analysis of the role of capillary pressure of cold water injection into depleted geothermal reservoirs are presented. A simplified 1-D mathematical model is developed, that describes the motion of a sharp vaporization front. Some asymptotic estimates for a wide range of parameters are given and a similarity solution is derived. Analytical results are then compared with those obtained from the numerical reservoir simulator TOUGH2, showing a good agreement between the two. (author)

  9. A comparison of water-diesel emulsion and timed injection of water into the intake manifold of a diesel engine for simultaneous control of NO and smoke emissions

    International Nuclear Information System (INIS)

    Subramanian, K.A.

    2011-01-01

    Experiments were conducted to compare the effects of water-diesel emulsion and water injection into the intake manifold on performance, combustion and emission characteristics of a DI diesel engine under similar operating conditions. The water to diesel ratio for the emulsion was 0.4:1 by mass. The same water-diesel ratio was maintained for water injection method in order to assess both potential benefits. All tests were done at the constant speed of 1500 rpm at different outputs. The static injection timing of 23 o BTDC was kept as constant for all experimental tests. In the first phase, experiments were carried out to asses the performance, combustion and emission characteristics of the engine using the water-diesel emulsion. The emulsion was prepared using the surfactant of HLB:7. The emulsion was injected using the conventional injection system during the compression stroke. The second phase of work was that water was injected into the intake manifold of the engine using an auxiliary injector during the suction stroke. An electronic control unit (ECU) was developed to control the injector operation such as start of injection and water injection duration with respect to the desired crank angle. The experimental result indicates the both methods (emulsion and injection) could reduce NO emission drastically in diesel engines. At full load, NO emission decreased drastically from 1034 ppm with base diesel to 645 ppm with emulsion and 643 ppm with injection. But, NO emission reduction is lesser with injection than emulsion at part loads. Smoke emission is lower with the emulsion (2.7 BSU) than with water injection (3.2 BSU) as compared to base diesel (3.6 BSU). However, CO and HC levels were higher with emulsion than water injection. As regards NO and smoke reduction, the emulsion was superior to injection at all loads. Peak pressure, ignition delay and maximum rate of pressure rise were lesser with water injection as compared to the emulsion. It is well demonstrated

  10. Estimates of water source contributions in a dynamic urban water supply system inferred via a Bayesian stable isotope mixing model

    Science.gov (United States)

    Jameel, M. Y.; Brewer, S.; Fiorella, R.; Tipple, B. J.; Bowen, G. J.; Terry, S.

    2017-12-01

    Public water supply systems (PWSS) are complex distribution systems and critical infrastructure, making them vulnerable to physical disruption and contamination. Exploring the susceptibility of PWSS to such perturbations requires detailed knowledge of the supply system structure and operation. Although the physical structure of supply systems (i.e., pipeline connection) is usually well documented for developed cities, the actual flow patterns of water in these systems are typically unknown or estimated based on hydrodynamic models with limited observational validation. Here, we present a novel method for mapping the flow structure of water in a large, complex PWSS, building upon recent work highlighting the potential of stable isotopes of water (SIW) to document water management practices within complex PWSS. We sampled a major water distribution system of the Salt Lake Valley, Utah, measuring SIW of water sources, treatment facilities, and numerous sites within in the supply system. We then developed a hierarchical Bayesian (HB) isotope mixing model to quantify the proportion of water supplied by different sources at sites within the supply system. Known production volumes and spatial distance effects were used to define the prior probabilities for each source; however, we did not include other physical information about the supply system. Our results were in general agreement with those obtained by hydrodynamic models and provide quantitative estimates of contributions of different water sources to a given site along with robust estimates of uncertainty. Secondary properties of the supply system, such as regions of "static" and "dynamic" source (e.g., regions supplied dominantly by one source vs. those experiencing active mixing between multiple sources), can be inferred from the results. The isotope-based HB isotope mixing model offers a new investigative technique for analyzing PWSS and documenting aspects of supply system structure and operation that are

  11. Exhaust gas heat recovery through secondary expansion cylinder and water injection in an internal combustion engine

    Directory of Open Access Journals (Sweden)

    Nassiri Toosi Ali

    2017-01-01

    Full Text Available To enhance thermal efficiency and increase performance of an internal combustion engine, a novel concept of coupling a conventional engine with a secondary 4-stroke cylinder and direct water injection process is proposed. The burned gases after working in a traditional 4-stroke combustion cylinder are transferred to a secondary cylinder and expanded even more. After re-compression of the exhaust gases, pre-heated water is injected at top dead center. The evaporation of injected water not only recovers heat from exhaust gases, but also increases the mass of working gas inside the cylinder, therefore improves the overall thermal efficiency. A 0-D/1-D model is used to numerically simulate the idea. The simulations outputs showed that the bottoming cycle will be more efficient at higher engines speeds, specifically in a supercharged/turbocharged engine, which have higher exhaust gas pressure that can reproduce more positive work. In the modeled supercharged engine, results showed that brake thermal efficiency can be improved by about 17%, and brake power by about 17.4%.

  12. Numerical investigation of CAI Combustion in the Opposed- Piston Engine with Direct and Indirect Water Injection

    Science.gov (United States)

    Pyszczek, R.; Mazuro, P.; Teodorczyk, A.

    2016-09-01

    This paper is focused on the CAI combustion control in a turbocharged 2-stroke Opposed-Piston (OP) engine. The barrel type OP engine arrangement is of particular interest for the authors because of its robust design, high mechanical efficiency and relatively easy incorporation of a Variable Compression Ratio (VCR). The other advantage of such design is that combustion chamber is formed between two moving pistons - there is no additional cylinder head to be cooled which directly results in an increased thermal efficiency. Furthermore, engine operation in a Controlled Auto-Ignition (CAI) mode at high compression ratios (CR) raises a possibility of reaching even higher efficiencies and very low emissions. In order to control CAI combustion such measures as VCR and water injection were considered for indirect ignition timing control. Numerical simulations of the scavenging and combustion processes were performed with the 3D CFD multipurpose AVL Fire solver. Numerous cases were calculated with different engine compression ratios and different amounts of directly and indirectly injected water. The influence of the VCR and water injection on the ignition timing and engine performance was determined and their application in the real engine was discussed.

  13. Mapping Precipitation Patterns from the Stable Isotopic Composition of Surface Waters: Olympic Peninsula, Washington State

    Science.gov (United States)

    Anders, A. M.; Brandon, M. T.

    2008-12-01

    Available data indicate that large and persistent precipitation gradients are tied to topography at scales down to a few kilometers, but precipitation patterns in the majority of mountain ranges are poorly constrained at scales less than tens of kilometers. A lack of knowledge of precipitation patterns hampers efforts to understand the processes of orographic precipitation and identify the relationships between geomorphic evolution and climate. A new method for mapping precipitation using the stable isotopic composition of surface waters is tested in the Olympic Mountains of Washington State. Measured δD and δ18O of 97 samples of surface water are linearly related and nearly inseparable from the global meteoric water line. A linear orographic precipitation model extended to include in effects of isotopic fractionation via Rayleigh distillation predicts precipitation patterns and isotopic composition of surface water. Seven parameters relating to the climate and isotopic composition of source water are used. A constrained random search identifies the best-fitting parameter set. Confidence intervals for parameter values are defined and precipitation patterns are determined. Average errors for the best-fitting model are 4.8 permil in δD. The difference between the best fitting model and other models within the 95% confidence interval was less than 20%. An independent high-resolution precipitation climatology documents precipitation gradients similar in shape and magnitude to the model derived from surface water isotopic composition. This technique could be extended to other mountain ranges, providing an economical and fast assessment of precipitation patterns requiring minimal field work.

  14. Stable water isotope variation in a Central Andean watershed dominated by glacier and snowmelt

    Directory of Open Access Journals (Sweden)

    N. Ohlanders

    2013-03-01

    Full Text Available Central Chile is an economically important region for which water supply is dependent on snow- and ice melt. Nevertheless, the relative contribution of water supplied by each of those two sources remains largely unknown. This study represents the first attempt to estimate the region's water balance using stable isotopes of water in streamflow and its sources. Isotopic ratios of both H and O were monitored during one year in a high-altitude basin with a moderate glacier cover (11.5%. We found that the steep altitude gradient of the studied catchment caused a corresponding gradient in snowpack isotopic composition and that this spatial variation had a profound effect on the temporal evolution of streamflow isotopic composition during snowmelt. Glacier melt and snowmelt contributions to streamflow in the studied basin were determined using a quantitative analysis of the isotopic composition of streamflow and its sources, resulting in a glacier melt contribution of 50–90% for the unusually dry melt year of 2011/2012. This suggests that in (La Niña years with little precipitation, glacier melt is an important water source for central Chile. Predicted decreases in glacier melt due to global warming may therefore have a negative long-term impact on water availability in the Central Andes. The pronounced seasonal pattern in streamflow isotope composition and its close relation to the variability in snow cover and discharge presents a potentially powerful tool to relate discharge variability in mountainous, melt-dominated catchments with related factors such as contributions of sources to streamflow and snowmelt transit times.

  15. Assessment of water quality of the Odaw river catchment using hydrochemistry and stable isotope techniques

    International Nuclear Information System (INIS)

    Kemetse, J. K.

    2014-07-01

    The physico-chemical and isotopic properties of water In the Odaw River catchment including some hand-dug wells and water from the unsaturated zone were assessed to ascertain the impact of human activities on the water quality and also to assess the vulnerability of ground water resources in the catchment. Samples were collected from October, 2013 to March, 2014 using well washed plastic bottles. During every sampling session; temperature, conductivity, salinity, turbidity and pH were measured in situ using HACH portable conductivity meter and a pH meter. Alkalinity and bicarbonates were determined by titration. In the laboratory, total dissolved solid (TDS) and total suspended solids (TSS) were determined using calorimetric methods. Total hardness, chemical oxygen demand (COD), biochemical oxygen demand (BOD) and dissolved oxygen (DO) and calcium were determined by titration. Anions such as nitrates, phosphates, sulphate, chloride, fluoride were analyzed by Ion Chromatography, while Flame Photometry was used to analyze sodium and potassium. Atomic Absorption Spectroscopy (AAS) was used to determine magnesium, cadmium, mercury, lead and arsenic. Liquid isotope analyzer was also used for the determination of 18 O and 2 H. Stable isotopes of 18 O, 2 H and 15 N were analyzed to help understand the source and flow of nutrients into the catchment. Data were analyzed using Microsoft Excel-2003 and CCME WQI. From the results pH for the water samples upstream was acidic to slightly alkaline (2.8 - 8.1), midstream was alkaline (7.3 - 11.5) and the downstream was 6.4 -7.7; TDS, EC and salinity increased from the upstream to the downstream as the river approaches the lagoon. There was some amount of heavy metal contamination in all the samples with the exception of Cd which was below detection limit. Hg was also below detection limit in the upstream. The CCME WQI was calculated for the surface water samples using 16 physico-chemical parameters. Results indicated that the

  16. Automatic estimation of aquifer parameters using long-term water supply pumping and injection records

    Science.gov (United States)

    Luo, Ning; Illman, Walter A.

    2016-09-01

    Analyses are presented of long-term hydrographs perturbed by variable pumping/injection events in a confined aquifer at a municipal water-supply well field in the Region of Waterloo, Ontario (Canada). Such records are typically not considered for aquifer test analysis. Here, the water-level variations are fingerprinted to pumping/injection rate changes using the Theis model implemented in the WELLS code coupled with PEST. Analyses of these records yield a set of transmissivity ( T) and storativity ( S) estimates between each monitoring and production borehole. These individual estimates are found to poorly predict water-level variations at nearby monitoring boreholes not used in the calibration effort. On the other hand, the geometric means of the individual T and S estimates are similar to those obtained from previous pumping tests conducted at the same site and adequately predict water-level variations in other boreholes. The analyses reveal that long-term municipal water-level records are amenable to analyses using a simple analytical solution to estimate aquifer parameters. However, uniform parameters estimated with analytical solutions should be considered as first rough estimates. More accurate hydraulic parameters should be obtained by calibrating a three-dimensional numerical model that rigorously captures the complexities of the site with these data.

  17. Laboratory evaluation and field application of a water swellable polymer for fracture shutoff in injection wells

    Energy Technology Data Exchange (ETDEWEB)

    Creel, Prentice [Kinder Morgan, Houston, TX (United States); Vasquez, Julio; Eoff, Larry [Halliburton, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    This paper presents the laboratory evaluation and field application of a water swelling polymer (WSP) that can be bullheaded to shut off fractures in injection wells. The WSP is capable of absorbing 30 to 400 times its own weight in water. The material was evaluated for its effectiveness in providing controllable swelling rates, shutting off the flow of water in synthetic cores with simulated fractures, and providing long-term stability in H{sub 2}S and CO{sub 2} environments. In addition, this paper presents the field implementation of this technology along with successful case histories in west Texas. The water swellable material is mixed on the fly, entering fissures and fracture systems as they swell without invading the matrix of the rock. The rate of absorption can be controlled based on the specified particle size ranging from 600-mesh size up to 14 mm and the type of carrier fluid. This WSP presents an innovative technology for fracture, fissure, and highly eroded out permeability shutoff to improve the sweep efficiency of water and gas injection. In addition, the WSP is resistant to acid contamination and CO{sub 2} and H{sub 2}S environments. To date, more than 200 jobs have been performed with this technology. (author)

  18. Air Sparging Versus Gas Saturated Water Injection for Remediation of Volatile LNAPL in the Borden Aquifer

    Science.gov (United States)

    Barker, J.; Nelson, L.; Doughty, C.; Thomson, N.; Lambert, J.

    2009-05-01

    In the shallow, rather homogeneous, unconfined Borden sand aquifer, field trials of air sparging (Tomlinson et al., 2003) and pulsed air sparging (Lambert et al., 2009) have been conducted, the latter to remediate a residual gasoline source emplaced below the water table. As well, a supersaturated (with CO2) water injection (SWI) technology, using the inVentures inFusion system, has been trialed in two phases: 1. in the uncontaminated sand aquifer to evaluate the radius of influence, extent of lateral gas movement and gas saturation below the water table, and 2. in a sheet pile cell in the Borden aquifer to evaluate the recovery of volatile hydrocarbon components (pentane and hexane) of an LNAPL emplaced below the water table (Nelson et al., 2008). The SWI injects water supersaturated with CO2. The supersaturated injected water moves laterally away from the sparge point, releasing CO2 over a wider area than does gas sparging from a single well screen. This presentation compares these two techniques in terms of their potential for remediating volatile NAPL components occurring below the water table in a rather homogeneous sand aquifer. Air sparging created a significantly greater air saturation in the vicinity of the sparge well than did the CO2 system (60 percent versus 16 percent) in the uncontaminated Borden aquifer. However, SWI pushed water, still supersaturated with CO2, up to about 2.5 m from the injection well. This would seem to provide a considerable advantage over air sparging from a point, in that gas bubbles are generated at a much larger radius from the point of injection with SWI and so should involve additional gas pathways through a residual NAPL. Overall, air sparging created a greater area of influence, defined by measurable air saturation in the aquifer, but air sparging also injected about 12 times more gas than was injected in the SWI trials. The pulsed air sparging at Borden (Lambert et al.) removed about 20 percent (4.6 kg) of gasoline

  19. Partitioning the effects of Global Warming on the Hydrological Cycle with Stable Isotopes in Water Vapor

    Science.gov (United States)

    Dee, S. G.; Russell, J. M.; Nusbaumer, J. M.; Konecky, B. L.; Buenning, N. H.; Lee, J. E.; Noone, D.

    2016-12-01

    General circulation models (GCMs) suggest that much of the global hydrological cycle's response to anthropogenic warming will be caused by increased lower-tropospheric water vapor concentrations and associated feedbacks. However, fingerprinting changes in the global hydrological cycle due to anthropogenic warming remains challenging. Held and Soden (2006) predicted that as lower-tropospheric water vapor increases, atmospheric circulation will weaken as climate warms to maintain the surface energy budget. Unfortunately, the strength of this feedback and the fallout for other branches of the hydrological cycle is difficult to constrain in situ or with GCMs alone. We demonstrate the utility of stable hydrogen isotope ratios in atmospheric water vapor to quantitatively trace changes in atmospheric circulation and convective mass flux in a warming world. We compare water isotope-enabled GCM experiments for control (present-day) CO2 vs. high CO2(2x, 4x) atmospheres in two GCMs, IsoGSM and iCAM5. We evaluate changes in the distribution of water vapor, vertical velocity (omega), and the stream function between these experiments in order to identify spatial patterns of circulation change over the tropical Pacific (where vertical motion is strong) and map the δD of water vapor associated with atmospheric warming. We also probe the simulations to isolate isotopic signatures associated with water vapor residence time, precipitation efficiency, divergence, and cloud physics. We show that there are robust mechanisms that moisten the troposphere and weaken convective mass flux, and that these mechanisms can be tracked using the δD of water vapor. Further, we find that these responses are most pronounced in the upper troposphere. These findings provide a framework to develop new metrics for the detection of global warming impacts to the hydrological cycle. Further, currently available satellite missions measure δD in the atmospheric boundary layer, the free atmosphere, or the

  20. An analysis on water hammer in liquid injection shutdown system of CANDU-9

    International Nuclear Information System (INIS)

    Kim, T. H.; Heo, J.; Han, S. K.; Choi, H. Y.; No, T. S.

    2000-01-01

    The water hammer analysis code, PTRAN, is used for computation of transient pressures and pressure differentials in the Liquid Injection Shutdown System(LISS) piping network of CANDU-9 to ensure that the design allowables for LEVEL C Service Limit are met for the water hammer loads resulting from the water hammer. The LISS piping network of CANDU-9 has incorporated design improvement in considering the water hammer, such as declining the horizontal part of helium header, and raising the elevation of the overall system piping configuration, etc. The maximum pressure in the LISS piping network is found to be 7.92 MPa(a) at the closed valve in the vent line, which is below the allowable working pressure and the valve design pressure under Level C service conditions. And it is also shown that the maximum pressure in CANDU-9 is much lower than that in CANDU-6

  1. Effect of capillary number on the oil recovery using oil-water emulsion injection in core flooding experiments

    Energy Technology Data Exchange (ETDEWEB)

    Guillen Nunez, Victor Raul; Carvalho, Marcio da Silveira [Pontifical Catholic University of Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. of Mechanical Engineering], E-mail: msn@puc-rio.br; Basante, Vladimir Alvarado [University of Wyoming, Laramie, WY (United States). Dept. of Chemical/Petroleum Engineering], E-mail: valvard@uwyo.edu

    2010-07-01

    The Water injection flooding is a common method to improve reservoir sweep and pressure maintenance. The heavy-oil-recovery efficiency is in part limited by the high water-to-oil mobility ratio. Several enhanced oil recovery methods are being developed as more efficient alternatives to water flooding. Dispersion injection, in particular oil-water emulsion injection, has been tried with relative success as an enhanced oil recovery method, but the technique is not fully developed or understood. If emulsion injection proves to be an effective EOR method, its use would bring the added benefit of disposing produced water with small oil content that could be modified to serve as the injected oil-water emulsion. The use of such methods requires a detailed analysis of the different flow regimes of emulsions through the porous space of a reservoir rock. If the drop size of the disperse phase is of the same order of magnitude as the pore size, the drops may agglomerate and partially block water flow through pores. This flow regime may be used to control the mobility of the injected liquid, leading to higher recovery factor. We have shown in recent experiments of oil displacement in a sandstone core that, the oil recovery factor could be raised from approximately 40 %, obtained with water injection only, up to approximately 75 % by alternating water and emulsion injection. Although these results clearly show the improvement in the recovery factor, the mechanisms responsible for the phenomenon have not been clearly elucidated. In this work, two sandstone cores were used to demonstrate the effect of flow rate (capillary number) on the mobility control by emulsion injection. Figure 1 shows a schematic representation of the experiment set-up. The experiments show that raising the flow rate by a factor of 10 (0.03 ml/min to 0.3 ml/min), the oil recovered factor decreases considerably. (author)

  2. Corrosion Study of the Injection Equipments in Water in Al-Ahdeb Wells ‐Iraq

    Directory of Open Access Journals (Sweden)

    Hassan Abdulkadhim Alwan Alsaadi

    2015-01-01

    Full Text Available Water injection equipments such as pipelines, which are used in the second recovery of oil in the Al-Ahdeb wells, suffer from the corrosion in water during maintaining vacuum deoxygenated tower that used to decrease concentration of the dissolved oxygen gas in the water from 6.2-9.1 ppm to o.5 ppm. This study involved calculation the corrosion rates of the internal surfaces of the pipelines either during operation of the vacuum unit or when the tower out of operation. Finally, find the solution by one of the following suggestions. In the first suggestion removal of the dissolved O2 from water is achieved by increasing the dosage of the oxygen scavenger (sodium sulphite. The second suggestion involves removing the dissolved O2 from water by bubbling the oxygenated water with nitrogen gas. The study showed that the corrosion rates of various inside diameter pipelines are between 0.13 mm/yr and 1.5 mm/yr during operation of the vacuum tower and between 3.2 mm/yr and 18.5 mm/yr when the tower out of the operation. While the results showed that the corrosion rate of the pipelines when the tower out of operation reached to the acceptable value of 0.1 mm/y when the dissolved oxygen in the injected water removed by increasing the dosage of the sodium sulphite (Na2SO3 to 48-72 ppm. The results also explained that corrosion rates of the pipelines reached to 0.5 mm/y when the dissolved oxygen removed by bubbling the water with nitrogen gas.

  3. Stable isotopes of water as a natural tracer for infiltration into urban sewer systems

    Science.gov (United States)

    Kracht, O.; Gresch, M.; de Bénédittis, J.; Prigiobbe, V.; Gujer, W.

    2003-04-01

    An adequate understanding of the hydraulic interaction between leaky sewers and groundwater is essential for the sustainable management of both sewer systems and aquifers in urbanized areas. Undesirable infiltration of groundwater into sewers can contribute over 50% of the total discharge and is detrimental to treatment plant efficiency. On the other hand, in many European cities groundwater surface levels seem to be particularly controlled by the drainage effect of permeable sewer systems. However, nowadays methods for the quantification of these exchange processes are still subject to considerable uncertainties due to their underlying assumptions. The frequently used assumption that the night time minimum in the diurnal wastewater hydrograph is equal to the "parasitic discharge" has to be reconsidered to today's patterns of human life as well as to the long residence time of wastewater in the sewer networks of modern cities. The suitability of stable water isotopes as a natural tracer to differentiate the origin of water in the sewer ("real" wastewater or infiltrating groundwater) is currently investigated in three different catchment areas. The studies are carried out within the framework of the European research project APUSS (Assessing Infiltration and Exfiltration on the Performance of Urban Sewer Systems): 1) The village of Rümlang (Zürich, Switzerland) is predominantly served with drinking water from the Lake Zürich. A large fraction of the lakes water is derived from precipitation in the Alps. This drinking water represents the intrinsic provenience of the wastewater with an δ18O value around -11,5 per mill and δ^2H value around -82 per mill vs. SMOW. In contrast, the local groundwater is originating from precipitation in a moderate altitude of about 450 m above sea level and shows comparatively enriched mean δ18O values of -9,7 per mill and δ^2H values of -70 per mill with only small natural variations. The isotopic separation between these

  4. A stable isotopic view on lianas' and trees' below ground competition for water

    Science.gov (United States)

    De Deurwaerder, Hannes; Hervé-Fernández, Pedro; Stahl, Clément; Bonal, Damien; Burban, Benoît; Petronelli, Pascal; Boeckx, Pascal; Verbeeck, Hans

    2017-04-01

    Various studies highlight an increase in liana abundance and biomass in the neotropics in the last decades. To date, the reason why this growth form expresses this trend is still unclear. One of the proposed hypotheses ascribes tropical lianas, in comparison to tropical trees, of being able to adapt better to increased drought conditions resulting from climate change. Moreover, lianas presumably have a deeper root system, providing access to deeper soil layers less susceptible for dehydration during drought events. A dual stable water isotopic approach (δ18O and δ2H) enables studying vegetation below ground competition and in combination with Bayesian mixing models can provide insight in the fractional contribution of distinct soil layer depths. In this perspective, precipitation (bulk and through fall), bulk soil (at different depths), stream and xylem water of both lianas and trees were sampled between October 7-13, 2015. The study focusses on two distinct plots differing in soil texture (sand and clay), localized in close vicinity of the Guyana flux tower at Paracou (French Guyana). Our study highlights the erroneous of the deep tap root hypothesis and provides new insights in water and nutrient competition between tropical lianas and trees during dry season. Lianas isotopic signature is enriched compared to those of trees. This can be linked to water source depth and soil seasonal replenishment. Moreover, liana displaying a very active soil surface root activity, efficiently capturing the low amount of dry season precipitation, while trees show to tap the deeper and less drought susceptible soil layers. A strategy, which not only results in a spatial niche separation in the underground competition for water, but it also provides lianas with a definite advantage in nutrient competition.

  5. Electrospun water-stable zein/ethyl cellulose composite nanofiber and its drug release properties

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Hangyi; Wang, Qingqing; Li, Guohui [Key Laboratory of Eco-textiles, Jiangnan University, Wuxi (China); Qiu, Yuyu [Key Laboratory of Eco-textiles, Jiangnan University, Wuxi (China); Laboratory of Natural Medicine, Wuxi Medical School, Jiangnan University (China); Wei, Qufu, E-mail: qfwei@jiangnan.edu.cn [Key Laboratory of Eco-textiles, Jiangnan University, Wuxi (China)

    2017-05-01

    A simple and cost-effective way to prepare water-stable zein-based nanofibers for potential drug delivery was presented in this article. Corn protein zein was co-electrospun with hydrophobic ethyl cellulose. Indomethacin, as a model drug, was incorporated in situ into the composite nanofibers. Scanning electron microscopy and element mapping revealed the morphologies of drug-loaded nanofibers and drug distribution, respectively. Fourier transform infrared spectra confirmed the physical blending among the components. Differential scanning calorimetry and X-ray diffraction demonstrated the physical state of drug and polymers in the nanofiber matrix. The composite nanofibers showed a sustained diffusion-controlled release according to the results of in vitro dissolution tests. - Highlights: • A simple, non-toxic and cost-effective way to improve water stability of zein nanofibers was proposed. • Electrospun zein/ethyl cellulose nanofibers with improved water stability and mechanical strength were prepared. • Indomethacin was homogeneously distributed in the zein/ethyl cellulose nanofibers with no aggregation or cluster. • The zein/ethyl cellulose nanofibers presented a sustained drug release profile, following Fickican diffusion mechanism.

  6. Experimental studies on seasonal heat storage based on stable supercooling of a sodium acetate water mixture

    DEFF Research Database (Denmark)

    Furbo, Simon; Dragsted, Janne; Fan, Jianhua

    2011-01-01

    to transfer heat to and from the module have been tested. Further, a solidification start method, based on a strong cooling of a small part of the salt water mixture in the module by boiling CO2 in a small brass tank in good thermal contact to the outer side of the module wall, has been tested. Tests......Laboratory tests of a 230 l seasonal heat storage module with a sodium acetate water mixture have been carried out. The aim of the tests is to elucidate how best to design a seasonal heat storage based on the salt water mixture, which supercools in a stable way. The module can be a part...... of a seasonal heat storage, that will be suitable for solar heating systems which can fully cover the yearly heat demand of Danish low energy buildings. The tested module has approximately the dimensions 2020 mm x 1285 mm x 80 mm. The module material is steel and the wall thickness is 2 mm. Different methods...

  7. Measurement of stable isotope ratio of organic carbon in water samples

    International Nuclear Information System (INIS)

    Fujii, Toshihiro; Otsuki, Akira

    1977-01-01

    A new method for the measurement of stable isotope ratios was investigated and applied to organic carbon's isotope ratio measurements in water samples. A few river water samples from Tsuchiura city were tested. After the wet oxidation of organic carbons to carbon dioxide in a sealed ampoule, the isotope ratios were determined with the gas chromatograph-quadrupole mass spectrometer combined with a total organic carbon analyser, under the dynamic conditions. The GC-MS had been equipped with the multiple ion detector-digital integrator system. The ion intensities at m/e 44 and 45 were simultaneously measured at a switching rate of 1 ms. The measurements with carbon dioxide acquired from sodium carbonate (53 μg) gave the isotope ratios with the variation coefficient of 0.62%. However, the variation coefficients obtained from organic carbons in natural water samples were 2 to 3 times as high as that from sodium carbonate. This method is simple and rapid and may be applied to various fields especially in biology and medicine. (auth.)

  8. Antifungal activity of water-stable copper-containing metal-organic frameworks

    Science.gov (United States)

    Bouson, Supaporn; Krittayavathananon, Atiweena; Phattharasupakun, Nutthaphon; Siwayaprahm, Patcharaporn; Sawangphruk, Montree

    2017-10-01

    Although metal-organic frameworks (MOFs) or porous coordination polymers have been widely studied, their antimicrobial activities have not yet been fully investigated. In this work, antifungal activity of copper-based benzene-tricarboxylate MOF (Cu-BTC MOF), which is water stable and industrially interesting, is investigated against Candida albicans, Aspergillus niger, Aspergillus oryzae and Fusarium oxysporum. The Cu-BTC MOF can effectively inhibit the growth rate of C. albicans and remarkably inhibit the spore growth of A. niger, A. oryzae and F. oxysporum. This finding shows the potential of using Cu-BTC MOF as a strong biocidal material against representative yeasts and moulds that are commonly found in the food and agricultural industries.

  9. Use of stable isotopes of water (d and o-18) in hydrological studies in the Jonkershoek valley

    CSIR Research Space (South Africa)

    Midgley, JJ

    1994-04-01

    Full Text Available Stable isotopes of water in rainfall and streams in the Jonkershoek Valley were used to determine the relative contribution of new water (i.e. rain) during storm flow conditions. Significant differences between rain and stream isotopic signatures...

  10. Impact on caesarean section rates following injections of sterile water (ICARIS): a multicentre randomised controlled trial.

    Science.gov (United States)

    Lee, Nigel; Mårtensson, Lena B; Homer, Caroline; Webster, Joan; Gibbons, Kristen; Stapleton, Helen; Dos Santos, Natalie; Beckmann, Michael; Gao, Yu; Kildea, Sue

    2013-05-03

    Sterile water injections have been used as an effective intervention for the management of back pain during labour. The objective of the current research is to determine if sterile water injections, as an intervention for back pain in labour, will reduce the intrapartum caesarean section rate. A double blind randomised placebo controlled trialSetting: Maternity hospitals in AustraliaParticipants: 1866 women in labour, ≥18 years of age who have a singleton pregnancy with a fetus in a cephalic presentation at term (between 37 + 0 and 41 + 6 weeks gestation), who assess their back pain as equal to or greater than seven on a visual analogue scale when requesting analgesia and able to provide informed consent. Participants will be randomised to receive either 0.1 to 0.3 millilitres of sterile water or a normal saline placebo via four intradermal injections into four anatomical points surrounding the Michaelis' rhomboid over the sacral area. Two injections will be administered over the posterior superior iliac spine (PSIS) and the remaining two at two centimetres posterior, and one centimetre medial to the PSIS respectively. Proportion of women who have a caesarean section in labour.Randomisation: Permuted blocks stratified by research site.Blinding (masking):Double-blind trial in which participants, clinicians and research staff blinded to group assignment. Funded by the National Health and Medical Research CouncilTrial registration:Australian New Zealand Clinical Trials Registry (No ACTRN12611000221954). Sterile water injections, which may have a positive effect on reducing the CS rate, have been shown to be a safe and simple analgesic suitable for most maternity settings. A procedure that could reduce intervention rates without adversely affecting safety for mother and baby would benefit Australian families and taxpayers and would reduce requirements for maternal operating theatre time. Results will have external validity, as the technique may be easily applied to

  11. Every apple has a voice: using stable isotopes to teach about food sourcing and the water cycle

    Science.gov (United States)

    Oerter, Erik; Malone, Molly; Putman, Annie; Drits-Esser, Dina; Stark, Louisa; Bowen, Gabriel

    2017-07-01

    Agricultural crops such as fruits take up irrigation and meteoric water and incorporate it into their tissue (fruit water) during growth, and the geographic origin of a fruit may be traced by comparing the H and O stable isotope composition (δ2H and δ18O values) of fruit water to the global geospatial distribution of H and O stable isotopes in precipitation. This connection between common fruits and the global water cycle provides an access point to connect with a variety of demographic groups to educate about isotope hydrology and the water cycle. Within the context of a 1-day outreach activity designed for a wide spectrum of participants (high school students, undergraduate students, high school science teachers) we developed introductory lecture materials, in-class participatory demonstrations of fruit water isotopic measurement in real time, and a computer lab exercise to couple actual fruit water isotope data with open-source online geospatial analysis software. We assessed learning outcomes with pre- and post-tests tied to learning objectives, as well as participant feedback surveys. Results indicate that this outreach activity provided effective lessons on the basics of stable isotope hydrology and the water cycle. However, the computer lab exercise needs to be more specifically tailored to the abilities of each participant group. This pilot study provides a foundation for further development of outreach materials that can effectively engage a range of participant groups in learning about the water cycle and the ways in which humans modify the water cycle through agricultural activity.

  12. Influence of ph on corrosion control of carbon steel by peroxide injection in sour water

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Martins Magda; Baptista, Walmar; Joia, Carlos Jose Bandeira de Mello [PROTEMP - PETROBRAS/CENPES, Cidade Universitaria, Quadra 7, Rio de Janeiro, CEP 21949-900 (Brazil); Ponciano, Gomes Jose Antonio da Cunha [Departamento de Engenharia Metalurgica e de Materiais-COPPE/UFRJ, Cidade Universitaria, Rio de Janeiro (Brazil)

    2004-07-01

    Sour hydrogen damage is considered the most important corrosive process in the light-ends recovery section of Fluid Catalytic Cracking Units (FCCU). Corrosion in this condition is due to heavy gas oil that originates great amount of contaminants, such as H{sub 2}S, NH{sub 3} and HCN. Hydrogen absorption is promoted by the presence of free cyanides in the environment. The attenuation of this process requires the use of some inhibitors, such as oxygen, hydrogen peroxide (H{sub 2}O{sub 2}) or commercial polysulfides. The effect of these compounds is to neutralize free cyanides (CN{sup -}) into thio-sulfides (SCN{sup -}). When peroxide injection is selected, cyanide concentration in sour water has been used as key parameter to start the peroxide introduction. However, the importance of pH in this system has been pointed out by many authors. The aim of this work is to investigate the influence of pH when peroxide injection is carried out in less alkaline conditions of sour water. Electrochemical techniques - like anodic polarization and hydrogen permeation tests - and weight loss measurements were used to evaluate the effectiveness of corrosion control of carbon steel. It was concluded that at pH 7.5 peroxide injection can drive to an increment of the corrosion rate. Besides that, it was concluded that hydrogen permeation into the metal is promoted. Both detrimental effects were due to elemental sulfur generation in this pH range. The adoption of pH as a key parameter for peroxide injection is then suggested. (authors)

  13. Surface self-potential patterns related to transmissive fracture trends during a water injection test

    Science.gov (United States)

    DesRoches, A. J.; Butler, K. E.; MacQuarrie, K. TB

    2018-03-01

    Variations in self-potential (SP) signals were recorded over an electrode array during a constant head injection test in a fractured bedrock aquifer. Water was injected into a 2.2 m interval isolated between two inflatable packers at 44 m depth in a vertical well. Negative SP responses were recorded on surface corresponding to the start of the injection period with strongest magnitudes recorded in electrodes nearest the well. SP response decreased in magnitude at electrodes further from the well. Deflation of the packer system resulted in a strong reversal in the SP signal. Anomalous SP patterns observed at surface at steady state were found to be aligned with dominant fracture strike orientations found within the test interval. Numerical modelling of fluid and current flow within a simplified fracture network showed that azimuthal patterns in SP are mainly controlled by transmissive fracture orientations. The strongest SP gradients occur parallel to hydraulic gradients associated with water flowing out of the transmissive fractures into the tighter matrix and other less permeable cross-cutting fractures. Sensitivity studies indicate that increasing fracture frequency near the well increases the SP magnitude and enhances the SP anomaly parallel to the transmissive set. Decreasing the length of the transmissive fractures leads to more fluid flow into the matrix and into cross-cutting fractures proximal to the well, resulting in a more circular and higher magnitude SP anomaly. Results from the field experiment and modelling provide evidence that surface-based SP monitoring during constant head injection tests has the ability to identify groundwater flow pathways within a fractured bedrock aquifer.

  14. The effect of water injection on nitric oxide emissions of a gas turbine combustor burning ASTM Jet-A fuel

    Science.gov (United States)

    Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

    1973-01-01

    Tests were conducted to determine the effect of water injection on oxides of nitrogen (NOx) emissions of a full annular, ram induction gas turbine combustor burning ASTM Jet-A fuel. The combustor was operated at conditions simulating sea-level takeoff and cruise conditions. Water at ambient temperature was injected into the combustor primary zone at water-fuel ratios up to 2. At an inlet-air temperature of 589 K (600 F) water injection decreased the NOx emission index at a constant exponential rate: NOx = NOx (o) e to the -15 W/F power (where W/F is the water-fuel ratio and NOx(o) indicates the value with no injection). The effect of increasing combustor inlet-air temperature was to decrease the effect of the water injection. Other operating variables such as pressure and reference Mach number did not appear to significantly affect the percent reduction in NOx. Smoke emissions were found to decrease with increasing water injection.

  15. 40 CFR 60.4340 - How do I demonstrate continuous compliance for NOX if I do not use water or steam injection?

    Science.gov (United States)

    2010-07-01

    ... compliance for NOX if I do not use water or steam injection? 60.4340 Section 60.4340 Protection of....4340 How do I demonstrate continuous compliance for NOX if I do not use water or steam injection? (a) If you are not using water or steam injection to control NOX emissions, you must perform annual...

  16. Increasing hydro turbine operation range and efficiencies using water injection in draft tubes

    Energy Technology Data Exchange (ETDEWEB)

    Francke, Haakon Hjort

    2010-09-15

    It is a well known fact that most Francis turbines, because of the fixed blade design, faces challenges when running at partial load operation. Especially in the operating range below approximately 50 % of the rated output, it is common to observe severe pressure pulsations and surge in the draft tube. These pressure fluctuations are believed to be related to the swirling flow exiting the runner. By using water jets in the draft tube cone directed towards the swirling flow, the swirl strength is believed to be reduced and thereby also the pressure fluctuations produced by the swirl. This system thus has a potential of increasing the turbine operating range. The system can be activated when needed, and will not affect the turbine when running at its best efficiency point.Based on the main hypothesis, a simplified swirl rig was designed and constructed in order to investigate the nozzle influence on the swirling flow and on the pressure pulsations in a simplified environment. To expand the understanding of the nozzle performance in a Francis turbine, experiments were conducted in a model turbine with a prototype of movable nozzles. To establish a link between laboratory nozzle measurements and full scale nozzle measurements, field measurements were carried out on full scale Francis turbines running at partial discharge. For this purpose the turbines installed at Skarsfjord Power Station and Skibotn Power Station were used, where full scale nozzle injection systems were installed. The test results suggested that the concept of water injection worked, but not unconditionally. A reduction in pressure fluctuations was achieved both in laboratory and field experiments, as well as a noticeable reduction regarding fluctuations in the shaft run-out at Skibotn. In addition, water injection gave a surprisingly positive effect at overload conditions in the model turbine, even though the nozzle angle was directed in the same direction as the overload swirl. Ideally, the results

  17. Uniform and non-uniform inlet temperature of a vertical hot water jet injected into a rectangular tank

    KAUST Repository

    El-Amin, Mohamed; Sun, Shuyu

    2010-01-01

    In most of real-world applications, such as the case of heat stores, inlet is not kept at a constant temperature but it may vary with time during charging process. In this paper, a vertical water jet injected into a rectangular storage tank is measured experimentally and simulated numerically. Two cases of study are considered; one is a hot water jet with uniform inlet temperature (UIT) injected into a cold water tank, and the other is a cold water jet with non-uniform inlet temperature (NUIT) injected into a hot water tank. Three different temperature differences and three different flow rates are studied for the hot water jet with UIT which is injected into a cold water tank. Also, three different initial temperatures with constant flow rate as well as three different flow rates with constant initial temperature are considered for the cold jet with NUIT which is injected into a hot water tank. Turbulence intensity at the inlet as well as Reynolds number for the NUIT cases are therefore functions of inlet temperature and time. Both experimental measurements and numerical calculations are carried out for the same measured flow and thermal conditions. The realizable k-ε model is used for modeling the turbulent flow. Numerical solutions are obtained for unsteady flow while pressure, velocity, temperature and turbulence distributions inside the water tank are analyzed. The simulated results are compared to the measured results, and they show a good agreement at low temperatures. © 2010 IEEE.

  18. Uniform and non-uniform inlet temperature of a vertical hot water jet injected into a rectangular tank

    KAUST Repository

    El-Amin, Mohamed

    2010-12-01

    In most of real-world applications, such as the case of heat stores, inlet is not kept at a constant temperature but it may vary with time during charging process. In this paper, a vertical water jet injected into a rectangular storage tank is measured experimentally and simulated numerically. Two cases of study are considered; one is a hot water jet with uniform inlet temperature (UIT) injected into a cold water tank, and the other is a cold water jet with non-uniform inlet temperature (NUIT) injected into a hot water tank. Three different temperature differences and three different flow rates are studied for the hot water jet with UIT which is injected into a cold water tank. Also, three different initial temperatures with constant flow rate as well as three different flow rates with constant initial temperature are considered for the cold jet with NUIT which is injected into a hot water tank. Turbulence intensity at the inlet as well as Reynolds number for the NUIT cases are therefore functions of inlet temperature and time. Both experimental measurements and numerical calculations are carried out for the same measured flow and thermal conditions. The realizable k-ε model is used for modeling the turbulent flow. Numerical solutions are obtained for unsteady flow while pressure, velocity, temperature and turbulence distributions inside the water tank are analyzed. The simulated results are compared to the measured results, and they show a good agreement at low temperatures. © 2010 IEEE.

  19. Stable, water extractable isothiocyanates from Moringa oleifera leaves attenuate inflammation in vitro.

    Science.gov (United States)

    Waterman, Carrie; Cheng, Diana M; Rojas-Silva, Patricio; Poulev, Alexander; Dreifus, Julia; Lila, Mary Ann; Raskin, Ilya

    2014-07-01

    Moringa (Moringa oleifera Lam.) is an edible plant used as both a food and medicine throughout the tropics. A moringa concentrate (MC), made by extracting fresh leaves with water, utilized naturally occurring myrosinase to convert four moringa glucosinolates into moringa isothiocyanates. Optimum conditions maximizing MC yield, 4-[(α-L-rhamnosyloxy)benzyl]isothiocyanate, and 4-[(4'-O-acetyl-α-L-rhamnosyloxy)benzyl]isothiocyanate content were established (1:5 fresh leaf weight to water ratio at room temperature). The optimized MC contained 1.66% isothiocyanates and 3.82% total polyphenols. 4-[(4'-O-acetyl-α-L-rhamnosyloxy)benzyl]isothiocyanate exhibited 80% stability at 37°C for 30 days. MC, and both of the isothiocyanates described above significantly decreased gene expression and production of inflammatory markers in RAW macrophages. Specifically, both attenuated expression of iNOS and IL-1β and production of nitric oxide and TNFα at 1 and 5 μM. These results suggest a potential for stable and concentrated moringa isothiocyanates, delivered in MC as a food-grade product, to alleviate low-grade inflammation associated with chronic diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Highly Water-Stable Lanthanide-Oxalate MOFs with Remarkable Proton Conductivity and Tunable Luminescence.

    Science.gov (United States)

    Zhang, Kun; Xie, Xiaoji; Li, Hongyu; Gao, Jiaxin; Nie, Li; Pan, Yue; Xie, Juan; Tian, Dan; Liu, Wenlong; Fan, Quli; Su, Haiquan; Huang, Ling; Huang, Wei

    2017-09-01

    Although proton conductors derived from metal-organic frameworks (MOFs) are highly anticipated for various applications including solid-state electrolytes, H 2 sensors, and ammonia synthesis, they are facing serious challenges such as poor water stability, fastidious working conditions, and low proton conductivity. Herein, we report two lanthanide-oxalate MOFs that are highly water stable, with so far the highest room-temperature proton conductivity (3.42 × 10 -3 S cm -1 ) under 100% relative humidity (RH) among lanthanide-based MOFs and, most importantly, luminescent. Moreover, the simultaneous response of both the proton conductivity and luminescence intensity to RH allows the linkage of proton conductivity with luminescence intensity. This way, the electric signal of proton conductivity variation versus RH will be readily translated to optical signal of luminescence intensity, which can be directly visualized by the naked eye. If proper lanthanide ions or even transition-metal ions are used, the working wavelengths of luminescence emissions can be further extended from visible to near infrared light for even wider-range applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Pleistocene paleo-groundwater as a pristine fresh water resource in southern Germany – evidence from stable and radiogenic isotopes

    International Nuclear Information System (INIS)

    Geldern, Robert van; Baier, Alfons; Subert, Hannah L.; Kowol, Sigrid; Balk, Laura; Barth, Johannes A.C.

    2014-01-01

    Shallow groundwater aquifers are often influenced by anthropogenic contaminants or increased nutrient levels. In contrast, deeper aquifers hold potentially pristine paleo-waters that are not influenced by modern recharge. They thus represent important water resources, but their recharge history is often unknown. In this study groundwater from two aquifers in southern Germany were analyzed for their hydrogen and oxygen stable isotope compositions. One sampling campaign targeted the upper aquifer that is actively recharged by modern precipitation, whereas the second campaign sampled the confined, deep Benkersandstein aquifer. The groundwater samples from both aquifers were compared to the local meteoric water line to investigate sources and conditions of groundwater recharge. In addition, the deep groundwater was dated by tritium and radiocarbon analyses. Stable and radiogenic isotope data indicate that the deep-aquifer groundwater was not part of the hydrological water cycle in the recent human history. The results show that the groundwater is older than ∼20,000 years and most likely originates from isotopically depleted melt waters of the Pleistocene ice age. Today, the use of this aquifer is strictly regulated to preserve the pristine water. Clear identification of such non-renewable paleo-waters by means of isotope geochemistry will help local water authorities to enact and justify measures for conservation of these valuable resources for future generations in the context of a sustainable water management. - Highlights: • Groundwater from deep aquifer identified as paleo-water with age over 20,000 years. • Low stable isotope values indicate recharge during Pleistocene. • Shallow aquifer mirrors stable isotope signature of average modern precipitation. • Identification of non-renewable paleo-waters enhance sustainable water management. • Strict protection measures of authorities justified by isotope geochemistry

  2. Pleistocene paleo-groundwater as a pristine fresh water resource in southern Germany – evidence from stable and radiogenic isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Geldern, Robert van, E-mail: robert.van.geldern@fau.de [Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Department of Geography and Geosciences, GeoZentrum Nordbayern, Schlossgarten 5, 91054 Erlangen (Germany); Baier, Alfons; Subert, Hannah L. [Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Department of Geography and Geosciences, GeoZentrum Nordbayern, Schlossgarten 5, 91054 Erlangen (Germany); Kowol, Sigrid [Erlanger Stadtwerke AG, Äußere Brucker Str. 33, 91052 Erlangen (Germany); Balk, Laura; Barth, Johannes A.C. [Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Department of Geography and Geosciences, GeoZentrum Nordbayern, Schlossgarten 5, 91054 Erlangen (Germany)

    2014-10-15

    Shallow groundwater aquifers are often influenced by anthropogenic contaminants or increased nutrient levels. In contrast, deeper aquifers hold potentially pristine paleo-waters that are not influenced by modern recharge. They thus represent important water resources, but their recharge history is often unknown. In this study groundwater from two aquifers in southern Germany were analyzed for their hydrogen and oxygen stable isotope compositions. One sampling campaign targeted the upper aquifer that is actively recharged by modern precipitation, whereas the second campaign sampled the confined, deep Benkersandstein aquifer. The groundwater samples from both aquifers were compared to the local meteoric water line to investigate sources and conditions of groundwater recharge. In addition, the deep groundwater was dated by tritium and radiocarbon analyses. Stable and radiogenic isotope data indicate that the deep-aquifer groundwater was not part of the hydrological water cycle in the recent human history. The results show that the groundwater is older than ∼20,000 years and most likely originates from isotopically depleted melt waters of the Pleistocene ice age. Today, the use of this aquifer is strictly regulated to preserve the pristine water. Clear identification of such non-renewable paleo-waters by means of isotope geochemistry will help local water authorities to enact and justify measures for conservation of these valuable resources for future generations in the context of a sustainable water management. - Highlights: • Groundwater from deep aquifer identified as paleo-water with age over 20,000 years. • Low stable isotope values indicate recharge during Pleistocene. • Shallow aquifer mirrors stable isotope signature of average modern precipitation. • Identification of non-renewable paleo-waters enhance sustainable water management. • Strict protection measures of authorities justified by isotope geochemistry.

  3. Stable water isotopes in the coupled atmosphere–land surface model ECHAM5-JSBACH

    Directory of Open Access Journals (Sweden)

    B. Haese

    2013-09-01

    Full Text Available In this study we present first results of a new model development, ECHAM5-JSBACH-wiso, where we have incorporated the stable water isotopes H218O and HDO as tracers in the hydrological cycle of the coupled atmosphere–land surface model ECHAM5-JSBACH. The ECHAM5-JSBACH-wiso model was run under present-day climate conditions at two different resolutions (T31L19, T63L31. A comparison between ECHAM5-JSBACH-wiso and ECHAM5-wiso shows that the coupling has a strong impact on the simulated temperature and soil wetness. Caused by these changes of temperature and the hydrological cycle, the δ18O in precipitation also shows variations from −4‰ up to 4‰. One of the strongest anomalies is shown over northeast Asia where, due to an increase of temperature, the δ18O in precipitation increases as well. In order to analyze the sensitivity of the fractionation processes over land, we compare a set of simulations with various implementations of these processes over the land surface. The simulations allow us to distinguish between no fractionation, fractionation included in the evaporation flux (from bare soil and also fractionation included in both evaporation and transpiration (from water transport through plants fluxes. While the isotopic composition of the soil water may change for δ18O by up to +8&permil:, the simulated δ18O in precipitation shows only slight differences on the order of ±1‰. The simulated isotopic composition of precipitation fits well with the available observations from the GNIP (Global Network of Isotopes in Precipitation database.

  4. Stable water isotope simulation by current land-surface schemes:Results of IPILPS phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Henderson-Sellers, A.; Fischer, M.; Aleinov, I.; McGuffie, K.; Riley, W.J.; Schmidt, G.A.; Sturm, K.; Yoshimura, K.; Irannejad, P.

    2005-10-31

    Phase 1 of isotopes in the Project for Intercomparison of Land-surface Parameterization Schemes (iPILPS) compares the simulation of two stable water isotopologues ({sup 1}H{sub 2} {sup 18}O and {sup 1}H{sup 2}H{sup 16}O) at the land-atmosphere interface. The simulations are off-line, with forcing from an isotopically enabled regional model for three locations selected to offer contrasting climates and ecotypes: an evergreen tropical forest, a sclerophyll eucalypt forest and a mixed deciduous wood. Here we report on the experimental framework, the quality control undertaken on the simulation results and the method of intercomparisons employed. The small number of available isotopically-enabled land-surface schemes (ILSSs) limits the drawing of strong conclusions but, despite this, there is shown to be benefit in undertaking this type of isotopic intercomparison. Although validation of isotopic simulations at the land surface must await more, and much more complete, observational campaigns, we find that the empirically-based Craig-Gordon parameterization (of isotopic fractionation during evaporation) gives adequately realistic isotopic simulations when incorporated in a wide range of land-surface codes. By introducing two new tools for understanding isotopic variability from the land surface, the Isotope Transfer Function and the iPILPS plot, we show that different hydrological parameterizations cause very different isotopic responses. We show that ILSS-simulated isotopic equilibrium is independent of the total water and energy budget (with respect to both equilibration time and state), but interestingly the partitioning of available energy and water is a function of the models' complexity.

  5. Flow injection spectrophotometric determination of low concentrations of orthosphate in natural waters employing ion exchange resin

    International Nuclear Information System (INIS)

    Pessenda, L.C.R.

    1981-01-01

    A simple and fast method for the determination of low concentrations of orthophosphate in natural waters is described. Ion exchange is incorporated into a flow injection system by usina a resin column in the sample loop of a proportion injector. Effects of sample aspiration rate, sampling time, eluting agent concentration, pumping rate of the sample carrier stream and interfaces, were investigated both using 32 PO 3- 4 or 31 PO 3- 4 with columns coupled to a gerger-muller detector and incorporated in a flow system with molybdenum blue colorinetry. (M.A.C.) [pt

  6. Debinding behaviour of a water soluble PEG/PMMA binder for Ti metal injection moulding

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Gang [Department of Chemical and Materials Engineering, The University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Cao, Peng, E-mail: p.cao@auckland.ac.nz [Department of Chemical and Materials Engineering, The University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Wen, Guian [Department of Chemical and Materials Engineering, The University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Edmonds, Neil [School of Chemical Science, The University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand)

    2013-05-15

    Polyethylene glycol (PEG) has been becoming a common component in the design of water soluble binder systems for metal injection moulding. Similar to solvent debinding, PEG can be leached out by water and the mechanism of debinding was proposed in the literature with somehow misleading information about the debinding mechanism, particularly about the formation of PEG gel. This work investigates the debinding behaviours of a PEG-based binder in titanium compacts. Titanium powder is formulated with PEG, poly(methyl methacrylate) (PMMA) and stearic acid (SA) to formulate titanium feedstock. To determine the debinding kinetics, the PEG removal percentages are measured at three different temperatures and for various specimen thicknesses. A mathematic model based on diffusion-controlled debinding process is established. The evolution of porous microstructure during the water debinding process is observed using scanning electron microscopy. Based on these observations, a water debinding mechanism for titanium alloy compacts formulated with PEG-based binders is proposed. - Highlights: ► The water-debinding behaviours of the PEG binder system were investigated. ► PEG dissolution and transportation, and the pore structure development. ► A water debinding mechanism of PEG-based binders is proposed. ► Incorrect explanation of PEG gelling in the literature is corrected. ► Correction/modification made as per the reviewers' comments and suggestions.

  7. Water-hammer in the cold leg during an SBLOCA due to cold ECCS injection

    International Nuclear Information System (INIS)

    Ortiz, M.G.; Ghan, L.S.

    1991-01-01

    Water-hammer might occur in the cold leg of pressurized water reactors (PWR) during small break loss-of-coolant accidents (SBLOCA's), when cold emergency core cooling system (ECCS) water is injected into a pipe that may be partially filled with saturated steam. The water may mix with the steam and cause it to condense abruptly. Depending on the flow regime present, slugs of liquid may then be accelerated towards each other or against the piping structure. The possibility of this phenomenon is of concern to us because it may become a dominant phenomenon and change the character of the transient. In performing the code scaling, applicability, and uncertainty study (CSAU) on a SBLOCA scenario, we had to examine the possibility that the transient being analyzed could experience water-hammer and thus depart from the scope of the study. Two criteria for water-hammer initiation were investigated and tested using a RELAP5/MOD3 simulation of the transient. Our results indicated a very low likelihood of occurrence of the phenomenon. 8 refs., 6 figs

  8. Debinding behaviour of a water soluble PEG/PMMA binder for Ti metal injection moulding

    International Nuclear Information System (INIS)

    Chen, Gang; Cao, Peng; Wen, Guian; Edmonds, Neil

    2013-01-01

    Polyethylene glycol (PEG) has been becoming a common component in the design of water soluble binder systems for metal injection moulding. Similar to solvent debinding, PEG can be leached out by water and the mechanism of debinding was proposed in the literature with somehow misleading information about the debinding mechanism, particularly about the formation of PEG gel. This work investigates the debinding behaviours of a PEG-based binder in titanium compacts. Titanium powder is formulated with PEG, poly(methyl methacrylate) (PMMA) and stearic acid (SA) to formulate titanium feedstock. To determine the debinding kinetics, the PEG removal percentages are measured at three different temperatures and for various specimen thicknesses. A mathematic model based on diffusion-controlled debinding process is established. The evolution of porous microstructure during the water debinding process is observed using scanning electron microscopy. Based on these observations, a water debinding mechanism for titanium alloy compacts formulated with PEG-based binders is proposed. - Highlights: ► The water-debinding behaviours of the PEG binder system were investigated. ► PEG dissolution and transportation, and the pore structure development. ► A water debinding mechanism of PEG-based binders is proposed. ► Incorrect explanation of PEG gelling in the literature is corrected. ► Correction/modification made as per the reviewers' comments and suggestions

  9. Detailed evaluation of the natural circulation mass flow rate of water propelled by using an air injection

    International Nuclear Information System (INIS)

    Park, Rae-Joon; Ha, Kwang-Soon; Kim, Jae-Cheol; Hong, Seong-Wan; Kim, Sang-Baik

    2008-01-01

    One-dimensional (1D) air-water two-phase natural circulation flow in the thermohydraulic evaluation of reactor cooling mechanism by external self-induced flow - one-dimensional' (THERMES-1D) experiment has been verified and evaluated by using the RELAP5/MOD3 computer code. Experimental results on the 1D natural circulation mass flow rate of water propelled by using an air injection have been evaluated in detail. The RELAP5 results have shown that an increase in the air injection rate to 50% of the total heat flux leads to an increase in the water circulation mass flow rate. However, an increase in the air injection rate from 50 to 100% does not affect the water circulation mass flow rate, because of the inlet area condition. As the height increases in the air injection part, the void fraction increases. However, the void fraction in the upper part of the air injector maintains a constant value. An increase in the air injection mass flow rate leads to an increase in the local void fraction, but it has no influence on the local pressure. An increase in the coolant inlet area leads to an increase in the water circulation mass flow rate. However, the water outlet area does not have an influence on the water circulation mass flow rate. As the coolant outlet moves to a lower position, the water circulation mass flow rate decreases. (author)

  10. Two Water Stable Copper Metal-Organic Frameworks with Performance in the Electrocatalytic Activity for Water Oxidation

    Directory of Open Access Journals (Sweden)

    Liu Xiuping

    2018-01-01

    Full Text Available Two novel water stable metal-organic frameworks, [Cu(L·(4,4′-bipy·(ClO4]n (1, [Cu(L·(phen·(ClO4·(H2O]2 (2, have been constructed by HL=[5-Mercapto-1-methyl] tetrazole acetic acid and Cu (II salt in the presence of assistant N-containing ligands. MOF 1 and MOF 2 with open CuII sites, resulting the framework 1 and 2 show electrocatalytic activity for water oxidation in alkaline solution. The electrochemical properties of complex for oxygen evolution reaction (OER were evaluated by linear sweep voltammetry (LSV and the Tafel slopes. Complex 1 has a higher LSV activity with a lower over potential of 1.54 V and a much higher increase in current density. Meanwhile, the Tafel slope of complex 1 (122.0 mV dec-1 is much lower than complex 2 (243.5 mV dec-1. This phenomenon makes complex 1 a promising porous material for electrocatalytic activity.

  11. A comparison of the toluene distillation and vacuum/heat methods for extracting soil water for stable isotopic analysis

    Science.gov (United States)

    Ingraham, Neil L.; Shadel, Craig

    1992-12-01

    Hanford Loam, from Richland, Washington, was used as a test soil to determine the precision, accuracy and nature of two methods to extract soil water for stable isotopic analysis: azeotropic distillation using toluene, and simple heating under vacuum. The soil was oven dried, rehydrated with water of known stable isotopic compositions, and the introduced water was then extracted. Compared with the introduced water, initial aliquots of evolved water taken during a toluene extraction were as much as 30 ‰ more depleted in D and 2.7 ‰ more depleted in 18O, whereas final aliquots were as much as 40 ‰ more enriched in D and 14.3 ‰ more enriched in 18O. Initial aliquots collected during the vacuum/heat extraction were as much as 64 ‰ more depleted in D and 8.4 ‰ more depleted in 18O than was the introduced water, whereas the final aliquots were as much as 139 ‰ more enriched in D, and 20.8 ‰ more enriched in 18O. Neither method appears quantitative; however, the difference in stable isotopic composition between the first and last aliquots of water extracted by the toluene method is less than that from the vacuum/heat method. This is attributed to the smaller fractionation factors involved with the higher average temperatures of distillation of the toluene. The average stable isotopic compositions of the extracted water varied from that of the introduced water by up to 1.4 ‰ in δD and 4.2 ‰ in δ18O with the toluene method, and by 11.0 ‰ in δD and 1.8 ‰ in δ18O for the vacuum/heat method. The lack of accuracy of the extraction methods is thought to be due to isotopic fractionation associated with water being weakly bound (not released below 110°C) in the soil. The isotopic effect of this heat-labile water is larger at low water contents (3.6 and 5.2% water by weight) as the water bound in the soil is a commensurately larger fraction of the total. With larger soilwater contents the small volume of water bound with an associated fractionation is

  12. Study of the effect of injecting cold or hot water on the operation of an oil field

    Energy Technology Data Exchange (ETDEWEB)

    Gusein-Zade, M A; Kolosovskaya, A K; Lebedev, V V; Chicherov, L G

    1968-11-01

    Several Soviet reservoirs contain either highly paraffinic or viscous crude oils, where recovery by an ordinary waterflood is poor. Under such circumstances, hot water injection appears to be advantageous. Hot water injection is advisable when: (1) the reservoir is heterogeneous and contains low-permeability sections; (2) the oil is saturated with paraffin at reservoir temperature; and (3) reservoir pressure is only slightly higher than static pressure. In Uzen field, hot water injection should recover 1.5 times more oil than would be recovered with cold water. Various problems involved with hot water injection such as equipment and methods of heating the water, transportation of the water of the wellhead, heat losses in transport of hot water, and well equipment for handling hot water are discussed. Calculations indicate that it should be possible to transport 100/sup 0/C water through a 5 km pipeline with a 4/sup 0/ to 6/sup 0/C temperature drop; then deliver to the well bottom at a temperature of 90/sup 0/ to 92/sup 0/C.

  13. Stable isotope estimates of evaporation: inflow and water residence time for lakes across the United States as a tool for national lake water quality assessments

    Science.gov (United States)

    Stable isotope ratios of water (delta18O and delta2H) can be very useful in large-scale monitoring programs because water samples are easy to collect and isotope ratios integrate information about basic hydrologic processes such as evaporation as a percentage of inflow (E/I) and ...

  14. Simulation bidimensional of water and gas alternative injection; Simulacao bidimensional de injecao alternada de agua e gas

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Ana Paula Silva C. de

    1999-07-01

    This dissertation presents a study of the unidimensional of water and gas alternate injection (WAG) using the stream line theory. It is considered incompressible fluid., unit mobility ratio, negligible capillary and gravitational effects, homogeneous and isotropic reservoir, isothermal flow two phases, oil and water, and three components, oil, water and gas. In the stream line theory, the following injection schemes are considered: staggered line five-spot, direct line and seven-spot. It is also considered that there is no flow among the streams. In the WAG calculations it is used the fractional flow theory and the method of characteristics, which consists of shock waves and rarefactions. The composition of these waves is said compatible if it satisfies the entropy condition. The solution goes through a certain path from the left to the right side constrained by the initial and boundary conditions. The gas injection is at a high pressure to ensure miscible displacement. It is considered first injection of a water bank and then, injection of a gas bank. We concluded that the gas injection at a high pressure recoveries all residual oil and the water saturation remains is greater than initial saturation. (author)

  15. A fast alternative to core plug tests for optimising injection water salinity for EOR

    DEFF Research Database (Denmark)

    Hassenkam, Tue; Andersson, Martin Peter; Hilner, Emelie Kristin Margareta

    2014-01-01

    of the clays which would lead to permanent reservoir damage but evidence of effectiveness at moderate salinity would offer the opportunity to dispose of produced water. The goal is to define boundary conditions so injection water salinity is high enough to prevent reservoir damage and low enough to induce...... the low salinity effect while keeping costs and operational requirements at a minimum. Traditional core plug testing for optimising conditions has some limitations. Each test requires a fresh sample, core testing requires sophisticated and expensive equipment, and reliable core test data requires several...... experiments can be done relatively quickly on very little material, it gives the possibility of testing salinity response on samples from throughout a reservoir and for gathering statistics. Our approach provides a range of data that can be used to screen core plug testing conditions and to provide extra data...

  16. Numerical analysis of water hammer induced by injection of subcooled water into steam flow in a horizontal pipe

    International Nuclear Information System (INIS)

    Minato, Akihiko; Nagoyoshi, Takuji; Nakamura, Akira; Fujii, Yuzo; Aya, Izuo; Yamane, Kenji

    2004-01-01

    Subcooled water injection into steam flow in piping systems may generate a water column containing a large steam slug. The steam slug collapses due to rapid condensation and interfaces on both sides collides with each other. Water hammer takes place and sharp pressure pulse propagates through the pipe. The purpose of this study is to show capability of the present numerical simulation method for predictions of pressure transient and loads on a piping system following steam slug collapse. A three-dimensional computer code for transient gas-liquid two-phase flow was applied to simulate an experiment of steam-condensation-induced water hammer with a horizontal polycarbonate pipe. The code was based on the extended two-fluid model, which treated interface motion using the VOF (Volume of Fluid) technique. The Godunov scheme of highly compressible single-phase flow was modified for application to the Riemann problem solution of gas-liquid mixture. Analysis of local steam slug collapse resulted in comparable peak pressure and pulse width of pressure transients with the observation. The calculation of pressure pulse propagation and impact load on piping system showed the quasi-steady pressure load was imposed especially on elbow at 1/10 of water hammer peak pressure. (author)

  17. Design and experimental investigations on six-stroke SI engine using acetylene with water injection.

    Science.gov (United States)

    Gupta, Keshav; Suthar, Kishanlal; Jain, Sheetal Kumar; Agarwal, Ghanshyam Das; Nayyar, Ashish

    2018-06-02

    In the present study, a four-stroke cycle gasoline engine is redesigned and converted into a six-stroke cycle engine and experimental study has been conducted using gasoline and acetylene as fuel with water injection at the end of the recompression stroke. Acetylene has been used as an alternative fuel along with gasoline and performance of the six-stroke spark ignition (SI) engine with these two fuels has been studied separately and compared. Brake power and thermal efficiency are found to be 5.18 and 1.55% higher with acetylene as compared to gasoline in the six-stroke engine. However, thermal efficiency is found to be 45% higher with acetylene in the six-stroke engine as compared to four-stroke SI engine. The CO and HC emissions were found to be reduced by 13.33 and 0.67% respectively with acetylene as compared to gasoline due to better combustion of acetylene. The NO x emission was reduced by 5.65% with acetylene due to lower peak temperature by water injection. The experimental results showed better engine performance and emissions with acetylene as fuel in the six-stroke engine.

  18. Stable Water Isotopologues in the Stratosphere Retrieved from Odin/SMR Measurements

    Directory of Open Access Journals (Sweden)

    Tongmei Wang

    2018-01-01

    Full Text Available Stable Water Isotopologues (SWIs are important diagnostic tracers for understanding processes in the atmosphere and the global hydrological cycle. Using eight years (2002–2009 of retrievals from Odin/SMR (Sub-Millimetre Radiometer, the global climatological features of three SWIs, H216O, HDO and H218O, the isotopic composition δD and δ18O in the stratosphere are analysed for the first time. Spatially, SWIs are found to increase with altitude due to stratospheric methane oxidation. In the tropics, highly depleted SWIs in the lower stratosphere indicate the effect of dehydration when the air comes through the cold tropopause, while, at higher latitudes, more enriched SWIs in the upper stratosphere during summer are produced and transported to the other hemisphere via the Brewer–Dobson circulation. Furthermore, we found that more H216O is produced over summer Northern Hemisphere and more HDO is produced over summer Southern Hemisphere. Temporally, a tape recorder in H216O is observed in the lower tropical stratosphere, in addition to a pronounced downward propagating seasonal signal in SWIs from the upper to the lower stratosphere over the polar regions. These observed features in SWIs are further compared to SWI-enabled model outputs. This helped to identify possible causes of model deficiencies in reproducing main stratospheric features. For instance, choosing a better advection scheme and including methane oxidation process in a specific model immediately capture the main features of stratospheric water vapor. The representation of other features, such as the observed inter-hemispheric difference of isotopic component, is also discussed.

  19. Determination of stable and radioactive isotopes in rain water in Sahel in 1975 and 1976

    International Nuclear Information System (INIS)

    Baudet, J.; Abi, B.

    1979-01-01

    The problem of desertification in Africa incites to materialize the circuit of the water vapour between its main source, the Gulf of Guinea, and its precipitation site. Some rainwater samples have been collected in Ouagadougou in 1975 and 1976 during the rainy season. The dosage of the stable isotopes D and O 18 and radioactive isotope T shows that in 1975, a year with a general rain deficit, the rain was formed in a continental air mass. On the contrary, in 1976, a year with excess rain, the rain was formed in a maritime air mass. A study of the wind flows at 600, 900, 1500 and 2100 m shows that in 1975 the monsoon penetration is limited to the bottom of the Gulf of Guinea facing Cameroons, while in 1976 it entered the African Continent through the whole Gulf Coast, from Senegal to Cameroons. In 1976, the monsoon went up in latitude 3 0 to 5 0 more to the north than in 1975 [fr

  20. Simulation and optimization of stable isotope 18O separation by water vacuum distillation

    International Nuclear Information System (INIS)

    Chen Yuyan; Qin Chuanjiang; Xiao Bin; Xu Jing'an

    2012-01-01

    In the research, a stable isotope 18 O separation column was set up by water vacuum distillation with 20 m packing height and 0.1 m diameter of the column. The self-developed special packing named PAC- 18 O was packed inside the column. Firstly, a model was created by using the Aspen Plus software, and then the simulation results were validated by test results. Secondly, a group of simulation results were created by Aspen Plus, and the optimal operation conditions were gotten by using the artificial neural network (ANN) and Statistica software. Considering comprehensive factors drawn from column pressure and from withdrawing velocity, conclusions were reached on the study of the impact on the abundance of the isotope 18 O. The final results show that the abundance of the isotope 18 O increases as column pressure dropping and withdrawing velocity decreasing. Besides, the optimal column pressure and the incidence formula between the abundance of the isotope 18 O and withdrawing velocity were gotten. The conclusion is that the method of simulation and optimization can be applied to 18 O industrial design and will be popular in traditional distillation process to realize optimization design. (authors)

  1. Physiochemical and environmental stable isotope profile of marine coastal water, Pakistan

    International Nuclear Information System (INIS)

    Mashiatullah, A.; Qureshi, R.M.; Javed, T.; Fazil, M.; Latif, Z.; Ahmad, N.

    2005-01-01

    Physiochemical and environmental stable isotope (delta /sup 13/C, delta /sup 18/O delta /sup 2/H, delta /sup 34/S) analysis of seawater samples collected from selected locations off Pakistan. Coast was performed to assess pollution scenario during 2002. Objective of the study was to establish a baseline data profile of Pakistan coastal waters. Coastal location includes: Indus Delta, Karachi Harbour, Southeast Coast Karachi, Northwest Coast Karachi, Sonmiani, Ormara. Pasni, Gwadar and Jiwani. In-situ physiochemical parameters such as: pH, electrical conductivity (E.C), salinity, turbidity and dissolved oxygen (DO) were performed with portable meters. Stable isotope of oxygen, hydrogen, carbon and sulfur was performed on GD -150 modified Mass Spectrometer. Values of delta /sup 18/O along the Sindh Coast (Indus Delta, Karachi Harbour High Tide, Karachi Harbour Low Tide, North West Coast South East Coast, Gadani), lie in range of -6.3 to -2.4 , -0.17 to -0.2, -0.13 to + 1.16, + 0.65 to + 1.25, + 0.88 to +0.93, and 1.14 %. SMOW respectively. The values of delta /sup 18/O along Baluchistan Coast (Sonmiani, Ormara, Pasni, Gwadar, and Jiwani) lie in the range of 0.74 to 1.08,0.77 to 0.82, 0.96 to + 1.07,0.38 to 1.23, and 0.45 to 0.83 % SMOW respectively. Values of delta /sup 13/ C of total dissolved inorganic carbon (TDIC) along Sindh Coast lie in the range of -2.7 to 0.55, -7.0 to -2.14, -11.48 to -2.98, -1.26 to 2.12, -2.91 to -0.56, and -1.31 to -0.28 % V- PDB. Values of delta /sup 13/ C of total dissolved inorganic carbon (TDIC) off Baluchistan Coast lie in the range of - 2.65 to -0.68, -8.5 to 0.07, -1.1 to 0.01, -1.3 to 0.47 and -5.2 to 0 % V-PDB respectively. Significantly depleted delta /sup 13/C (TDIC) values observed in water samples collected off Karachi coast, Indus Delta and Armor Coast indicate pollution inputs from industrial and domestic waste drains into shallow marine environment off these coasts. Carbon Isotope data shows that the Gwadar and Pasni are

  2. Identification of source and recharge zones in an aquifer system from water stable isotope. Case Study Bajo Cauca Antioqueno

    International Nuclear Information System (INIS)

    Palacio B, Paola Andrea; Betancur V, Teresita

    2008-01-01

    Hydrology and hydrogeochemical are auxiliary techniques to valid conceptual hydrogeology an recharge models. Stable isotopes from water trace sources and path flow and Tritium indicates age. This paper is about the use of D 18, D 2H y 3H to study the aquifer system on Bajo Cauca antioqueno

  3. New insights on ecosystem mercury cycling revealed by stable isotopes of mercury in water flowing from a headwater peatland catchment

    Science.gov (United States)

    Glenn E. Woerndle; Martin Tsz-Ki Tsui; Stephen D. Sebestyen; Joel D. Blum; Xiangping Nie; Randall K. Kolka

    2018-01-01

    Stable isotope compositions of mercury (Hg) were measured in the outlet stream and in soil cores at different landscape positions in a 9.7-ha boreal upland-peatland catchment. An acidic permanganate/persulfate digestion procedure was validated for water samples with high dissolved organic matter (DOM) concentrations through Hg spike addition analysis. We report a...

  4. Reconstruction of three centuries of annual accumulation rates based on the record of stable isotopes of water from Lomonosovfonna, Svalbard

    NARCIS (Netherlands)

    Pohjola, V.; Martma, T.; Meijer, H.A.J.; Moore, J.; Isaksson, E.; Vaikmae, R.; van de Wal, R.S.W.

    2002-01-01

    We use the upper 81 in of the record of stable isotopes of water from a 122 in long ice core from Lomonosovfonna, central Spitsbergen, Svalbard, to construct an ice-core chronology and the annual accumulation rates over the icefield. The isotope cycles are counted in the ice-core record using a

  5. Indian primacy procedures handbook for the public water system supervision (PWSS) program and the underground injection control (UIC) program

    International Nuclear Information System (INIS)

    1993-03-01

    The handbook defines primacy, the responsibilities of primacy, primacy's advantages and limitations, and how to seek primacy. Primacy is a provision in the 1986 Amendments to the Safe Drinking Water Act (SDWA). It allows Indian Tribes the opportunity to assume principal responsibility in the enforcement of public drinking water and/or underground injection control (UIC) regulations within the Indian Tribe's jurisdiction. To attain primacy a Tribe must have drinking water and underground injection control regulations which are at least as strict as EPA regulations, and must have an independent agency or organization within the Tribal government that has the power to enforce its regulations

  6. Identification of temperature-dependent water quality changes during a deep well injection experiment in a pyritic aquifer

    NARCIS (Netherlands)

    Prommer, H.; Stuijfzand, P.J.

    2005-01-01

    Artificial recharge is a technique used increasingly to supplement drinking water supplies. To assess the potential water quality changes that occur during subsurface passage, a comprehensive deep-well injection experiment was carried out for a recharge scheme, where pretreated, aerobic surface

  7. Study on the Effect of water Injection Momentum on the Cooling Effect of Rocket Engine Exhaust Plume

    Science.gov (United States)

    Yang, Kan; Qiang, Yanhui; Zhong, Chenghang; Yu, Shaozhen

    2017-10-01

    For the study of water injection momentum factors impact on flow field of the rocket engine tail flame, the numerical computation model of gas-liquid two phase flow in the coupling of high temperature and high speed gas flow and low temperature liquid water is established. The accuracy and reliability of the numerical model are verified by experiments. Based on the numerical model, the relationship between the flow rate and the cooling effect is analyzed by changing the water injection momentum of the water spray pipes. And the effective mathematical expression is obtained. What’s more, by changing the number of the water spray and using small flow water injection, the cooling effect is analyzed to check the application range of the mathematical expressions. The results show that: the impact and erosion of the gas flow field could be reduced greatly by water injection, and there are two parts in the gas flow field, which are the slow cooling area and the fast cooling area. In the fast cooling area, the influence of the water flow momentum and nozzle quantity on the cooling effect can be expressed by mathematical functions without causing bifurcation flow for the mainstream gas. The conclusion provides a theoretical reference for the engineering application.

  8. Integrated use of NMR, petrel and modflow in the modeling of SAGD produced water re-injection

    International Nuclear Information System (INIS)

    Campbell, K.; Phair, C; Alloisio, S; Novotny, M; Raven, S

    2011-01-01

    In the oil industry, steam assisted gravity drainage (SAGD) is a method used to enhance oil recovery in which production water disposal is a challenge. During this process, production water is re-injected into the reservoir and operators have to verify that it will not affect the quality of the surrounding fresh groundwater. This research aimed at determining the flow path and the time that produced water would take to reach an adjacent aquifer. This study was carried out on a horizontal well pair at the Axe Lake Area in northwestern Saskatchewan, using existing site data in Petrel to create a static hydrogeological model which was then exported to Modflow to simulate injection scenarios. This innovative method provided flow path of the re-injected water and time to reach the fresh with advantages over conventional hydrogeological modeling. The innovative workflow presented herein successfully provided useful information to assess the feasibility of the SAGD project and could be used for other projects.

  9. Plant Water Use Strategy in Response to Spatial and Temporal Variation in Precipitation Patterns in China: A Stable Isotope Analysis

    Directory of Open Access Journals (Sweden)

    Ying Zhao

    2018-03-01

    Full Text Available Spatial and temporal variation in precipitation patterns can directly alter the survival and growth of plants, yet in China there is no comprehensive and systematic strategy for plant use based on the effects of precipitation patterns. Here, we examined information from 93 published papers (368 plant species on plant xylem water stable isotopes (δD and δ18O in China. The results showed that: (1 The slope of the local meteoric water line (LMWL gradually increased from inland areas to the coast, as a result of continental and seasonal effects. The correlation between δD and δ18O in plant stem water is also well fitted and the correlation coefficients range from 0.78 to 0.89. With respect to the soil water line, the δ18O values in relation to depth (0–100 cm varied over time; (2 Plants’ main water sources are largely affected by precipitation patterns. In general, plants prioritize the use of stable and continuous water sources, while they have a more variable water uptake strategy under drought conditions; (3 There are no spatial and temporal variations in the contribution of the main water source (p > 0.05 because plants maintain growth by shifting their use of water sources when resources are unreliable.

  10. Pleistocene paleo-groundwater as a pristine fresh water resource in southern Germany--evidence from stable and radiogenic isotopes.

    Science.gov (United States)

    van Geldern, Robert; Baier, Alfons; Subert, Hannah L; Kowol, Sigrid; Balk, Laura; Barth, Johannes A C

    2014-10-15

    Shallow groundwater aquifers are often influenced by anthropogenic contaminants or increased nutrient levels. In contrast, deeper aquifers hold potentially pristine paleo-waters that are not influenced by modern recharge. They thus represent important water resources, but their recharge history is often unknown. In this study groundwater from two aquifers in southern Germany were analyzed for their hydrogen and oxygen stable isotope compositions. One sampling campaign targeted the upper aquifer that is actively recharged by modern precipitation, whereas the second campaign sampled the confined, deep Benkersandstein aquifer. The groundwater samples from both aquifers were compared to the local meteoric water line to investigate sources and conditions of groundwater recharge. In addition, the deep groundwater was dated by tritium and radiocarbon analyses. Stable and radiogenic isotope data indicate that the deep-aquifer groundwater was not part of the hydrological water cycle in the recent human history. The results show that the groundwater is older than ~20,000 years and most likely originates from isotopically depleted melt waters of the Pleistocene ice age. Today, the use of this aquifer is strictly regulated to preserve the pristine water. Clear identification of such non-renewable paleo-waters by means of isotope geochemistry will help local water authorities to enact and justify measures for conservation of these valuable resources for future generations in the context of a sustainable water management. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Every apple has a voice: using stable isotopes to teach about food sourcing and the water cycle

    Directory of Open Access Journals (Sweden)

    E. Oerter

    2017-07-01

    Full Text Available Agricultural crops such as fruits take up irrigation and meteoric water and incorporate it into their tissue (fruit water during growth, and the geographic origin of a fruit may be traced by comparing the H and O stable isotope composition (δ2H and δ18O values of fruit water to the global geospatial distribution of H and O stable isotopes in precipitation. This connection between common fruits and the global water cycle provides an access point to connect with a variety of demographic groups to educate about isotope hydrology and the water cycle. Within the context of a 1-day outreach activity designed for a wide spectrum of participants (high school students, undergraduate students, high school science teachers we developed introductory lecture materials, in-class participatory demonstrations of fruit water isotopic measurement in real time, and a computer lab exercise to couple actual fruit water isotope data with open-source online geospatial analysis software. We assessed learning outcomes with pre- and post-tests tied to learning objectives, as well as participant feedback surveys. Results indicate that this outreach activity provided effective lessons on the basics of stable isotope hydrology and the water cycle. However, the computer lab exercise needs to be more specifically tailored to the abilities of each participant group. This pilot study provides a foundation for further development of outreach materials that can effectively engage a range of participant groups in learning about the water cycle and the ways in which humans modify the water cycle through agricultural activity.

  12. Development of flow injection method for indirect copper determination with amperometric detection in drinking water samples

    Directory of Open Access Journals (Sweden)

    Nikolić-Mandić Snežana

    2012-01-01

    Full Text Available A gas-diffusion flow injection method with amperometric detection for indirect copper determination on a silver electrode is developed. The flow through system is equipped with two injection valves and a gas-diffusion unit. In the first step, a signal of cyanide solution was recorded. In the following step a signal of cyanide in the presence of copper was measured. Interferences (Cd(II, Co(II, Ag(I, Ni(II, Fe(III, Hg(II and Zn(II were investigated and successfully removed. The calibration graph is linear in the range 1-90 μmol dm-3 of copper, correlation coefficient is 0.993, the regression equation is I = (0.0455±0.0015c + (0.4611±0.0671, I is relative signal decrease in μA and c is concentration in μmol dm-3. Relative standard deviation for six consecutive injections of 30 μmol dm-3 copper(II was 1.47 % and for 1 μmol dm-3 copper(II was 3.40 %. The detection limit, calculated as 3 s/m (where s is a standard deviation of nine measurement of a reagent blank and m is the slope of the calibration curve, was 0.32 μmol dm-3, which corresponds to 2.44 ng of copper(II (loop volume was 0.12 cm3. The method enables 60 analyses per hour and it was successfully applied on determination of copper in drinking water samples. [Acknowledgements. The authors acknowledge the grant from the Ministry of Education and Science of the Republic of Serbia, Project number 172051

  13. Experimental and numerical study on the fracture of rocks during injection of CO2-saturated water

    Science.gov (United States)

    Li, Qi; Wu, Zhishen; Lei, Xing-Lin; Murakami, Yutaka; Satoh, Takashi

    2007-02-01

    Geological sequestration of CO2 into depleted hydrocarbon reserviors or saline aquifers presents the enormous potential to reduce greenhouse gas emission from fossil fuels. However, it may give rise to a complicated coupling physical and chemical process. One of the processes is the hydro-mechanical impact of CO2 injection. During the injection project, the increase of pore pressures of storing formations can induce the instability, which finally results in a catastrophic failure of disposal sites. This paper focuses mainly on the role of CO2-saturated water in the fracturing behavior of rocks. To investigate how much the dissolved CO2 can influence the pore pressure change of rocks, acoustic emission (AE) experiments were performed on sandstone and granite samples under triaxial conditions. The main innovation of this paper is to propose a time dependent porosity method to simulate the abrupt failure process, which is observed in the laboratory and induced by the pore pressure change due to the volume dilatancy of rocks, using a finite element scheme associated with two-phase characteristics. The results successfully explained the phenomena obtained in the physical experiments.

  14. Flow structure of conical distributed multiple gas jets injected into a water chamber

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jiajun; Yu, Yonggang [Nanjing University of Science and Technology, Nanjing (China)

    2017-04-15

    Based on an underwater gun firing project, a mock bullet with several holes on the head was designed and experimented to observe the combustion gas injected into a cylindrical water chamber through this mock bullet. The combustion gas jets contain one vertical central jet and 4 to 8 slant lateral jets. A high speed camera system was used to record the expansion of gas jets in the experimental study. In numerical simulations, the Euler two-fluid model and volume of fluid method were adopted to describe the gas-liquid flow. The results show the backflow zone in lateral jet is the main factor influencing the gas-liquid turbulent mixing in downstream. On cross sections, the gas volume fraction increased with time but the growth rate decreased. With a change of nozzle structure, the gas fraction was more affected than the shock structure.

  15. The Global Network of Isotopes in Rivers (GNIR): Integration of Stable Water Isotopes in Riverine Research and Management

    International Nuclear Information System (INIS)

    Halder, J.; Terzer, S.; Wassenaar, L.; Araguas, L.; Aggarwal, P.

    2015-01-01

    Rivers play a crucial role in the global water cycle as watershed-integrating hydrological conduits for returning terrestrial precipitation, runoff, surface and groundwater, as well as melting snow and ice back to the world’s oceans. The IAEA Global Network of Isotopes in Rivers (GNIR) is the coherent extension of the IAEA Global Network for Isotopes in Precipitation (GNIP) and aims to fill the informational data gaps between rainfall and river discharge. Whereas the GNIP has been surveying the stable hydrogen and oxygen isotopes, and tritium composition in precipitation, the objective of GNIR is to accumulate and disseminate riverine isotope data. We introduce the new global database of riverine water isotopes and evaluate its current long-term data holdings with the objective to improve the application of water isotopes and to inform water managers and researchers. An evaluation of current GNIR database holdings confirmed that seasonal variations of the stable water isotope composition in rivers are closely coupled to precipitation and snow-melt water run-off on a global scale. Rivers could be clustered on the basis of seasonal variations in their isotope composition and latitude. Results showed furthermore, that there were periodic phases within each of these groupings and additional modelling exercises allowed a priori prediction of the seasonal variability as well as the isotopic composition of stable water isotopes in rivers. This predictive capacity will help to improve existing and new sampling strategies, help to validate and interpret riverine isotope data, and identify important catchment processes. Hence, the IAEA promulgates and supports longterm hydrological isotope observation networks and the application of isotope studies complementary with conventional hydrological, water quality, and ecological studies. (author)

  16. Comparison of Microbial Community Compositions of Injection and Production Well Samples in a Long-Term Water-Flooded Petroleum Reservoir

    Science.gov (United States)

    Ren, Hong-Yan; Zhang, Xiao-Jun; Song, Zhi-yong; Rupert, Wieger; Gao, Guang-Jun; Guo, Sheng-xue; Zhao, Li-Ping

    2011-01-01

    Water flooding plays an important role in recovering oil from depleted petroleum reservoirs. Exactly how the microbial communities of production wells are affected by microorganisms introduced with injected water has previously not been adequately studied. Using denaturing gradient gel electrophoresis (DGGE) approach and 16S rRNA gene clone library analysis, the comparison of microbial communities is carried out between one injection water and two production waters collected from a working block of the water-flooded Gudao petroleum reservoir located in the Yellow River Delta. DGGE fingerprints showed that the similarities of the bacterial communities between the injection water and production waters were lower than between the two production waters. It was also observed that the archaeal composition among these three samples showed no significant difference. Analysis of the 16S rRNA gene clone libraries showed that the dominant groups within the injection water were Betaproteobacteria, Gammaproteobacteria and Methanomicrobia, while the dominant groups in the production waters were Gammaproteobacteria and Methanobacteria. Only 2 out of 54 bacterial operational taxonomic units (OTUs) and 5 out of 17 archaeal OTUs in the injection water were detected in the production waters, indicating that most of the microorganisms introduced by the injection water may not survive to be detected in the production waters. Additionally, there were 55.6% and 82.6% unique OTUs in the two production waters respectively, suggesting that each production well has its specific microbial composition, despite both wells being flooded with the same injection water. PMID:21858049

  17. Experimental and Numerical Investigation of the Effect of Process Conditions on Residual Wall Thickness and Cooling and Surface Characteristics of Water-Assisted Injection Molded Hollow Products

    Directory of Open Access Journals (Sweden)

    Hyungpil Park

    2015-01-01

    Full Text Available Recently, water-assisted injection molding was employed in the automobile industry to manufacture three-dimensional hollow tube-type products with functionalities. However, process optimization is difficult in the case of water-assisted injection molding because of the various rheological interactions between the injected water and the polymer. In this study, the boiling phenomenon that occurs because of the high melt temperature when injecting water and the molding characteristics of the hollow section during the water-assisted injection process were analyzed by a water-assisted injection molding analysis. In addition, the changes in the residual wall thickness accompanying changes in the process conditions were compared with the analysis results by considering water-assisted injection molding based on gas-assisted injection molding. Furthermore, by comparing the cooling characteristics and inner wall surface qualities corresponding to the formation of the hollow section by gas and water injections, a water-assisted injection molding technique was proposed for manufacturing hollow products with functionality.

  18. Using stable isotopes to determine seasonal variations in water uptake of summer maize under different fertilization treatments

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ying, E-mail: maying@igsnrr.ac.cn [Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 100101 Beijing (China); State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 210008 Nanjing (China); Song, Xianfang [Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 100101 Beijing (China)

    2016-04-15

    Fertilization and water both affect root water uptake in the nutrient and water cycle of the Soil-Plant-Atmosphere-Continuum (SPAC). In this study, dual stable isotopes (D and {sup 18}O) were used to determine seasonal variations in water uptake patterns of summer maize under different fertilization treatments in Beijing, China during 2013–2014. The contributions of soil water at different depths to water uptake were quantified by the MixSIAR Bayesian mixing model. Water uptake was mainly sourced from soil water in the 0–20 cm depth at the seeding (67.7%), jointing (60.5%), tasseling (47.5%), dough (41.4%), and harvest (43.9%) stages, and the 20–50 cm depth at the milk stage (32.8%). Different levels of fertilization application led to considerable differences in the proportional contribution of soil water at 0–20 cm (6.0–58.5%) and 20–50 cm (6.1–26.3%). There was little difference of contributions in the deep layers (50–200 cm) among treatments in 2013, whereas differences were observed in 50–90 cm at the milk stage and 50–200 cm at the dough stage during 2014. The main water uptake depth was concentrated in the upper soil layers (0–50 cm) during the wet season (2013), whereas a seasonal drought in 2014 promoted the contribution of soil water in deep layers. The contribution of soil water was significantly and positively correlated with the proportions of root length (r = 0.753, p < 0.01). The changes of soil water distribution were consistent with the seasonal variation in water uptake patterns. The present study identified water sources for summer maize under varying fertilization treatments and provided scientific implications for fertilization and irrigation management. - Highlights: • Dual stable isotopes and MixSIAR were coupled to quantify water uptake of maize. • Maize mainly used soil water in 20–50 cm at milk stage and 0–20 cm at other stages. • Fertilization treatments led to distinct water uptake pattern at 0–50 cm

  19. Using stable isotopes to determine seasonal variations in water uptake of summer maize under different fertilization treatments

    International Nuclear Information System (INIS)

    Ma, Ying; Song, Xianfang

    2016-01-01

    Fertilization and water both affect root water uptake in the nutrient and water cycle of the Soil-Plant-Atmosphere-Continuum (SPAC). In this study, dual stable isotopes (D and "1"8O) were used to determine seasonal variations in water uptake patterns of summer maize under different fertilization treatments in Beijing, China during 2013–2014. The contributions of soil water at different depths to water uptake were quantified by the MixSIAR Bayesian mixing model. Water uptake was mainly sourced from soil water in the 0–20 cm depth at the seeding (67.7%), jointing (60.5%), tasseling (47.5%), dough (41.4%), and harvest (43.9%) stages, and the 20–50 cm depth at the milk stage (32.8%). Different levels of fertilization application led to considerable differences in the proportional contribution of soil water at 0–20 cm (6.0–58.5%) and 20–50 cm (6.1–26.3%). There was little difference of contributions in the deep layers (50–200 cm) among treatments in 2013, whereas differences were observed in 50–90 cm at the milk stage and 50–200 cm at the dough stage during 2014. The main water uptake depth was concentrated in the upper soil layers (0–50 cm) during the wet season (2013), whereas a seasonal drought in 2014 promoted the contribution of soil water in deep layers. The contribution of soil water was significantly and positively correlated with the proportions of root length (r = 0.753, p < 0.01). The changes of soil water distribution were consistent with the seasonal variation in water uptake patterns. The present study identified water sources for summer maize under varying fertilization treatments and provided scientific implications for fertilization and irrigation management. - Highlights: • Dual stable isotopes and MixSIAR were coupled to quantify water uptake of maize. • Maize mainly used soil water in 20–50 cm at milk stage and 0–20 cm at other stages. • Fertilization treatments led to distinct water uptake pattern at 0–50 cm depth

  20. Analysis of gas turbine engines using water and oxygen injection to achieve high Mach numbers and high thrust

    Science.gov (United States)

    Henneberry, Hugh M.; Snyder, Christopher A.

    1993-01-01

    An analysis of gas turbine engines using water and oxygen injection to enhance performance by increasing Mach number capability and by increasing thrust is described. The liquids are injected, either separately or together, into the subsonic diffuser ahead of the engine compressor. A turbojet engine and a mixed-flow turbofan engine (MFTF) are examined, and in pursuit of maximum thrust, both engines are fitted with afterburners. The results indicate that water injection alone can extend the performance envelope of both engine types by one and one-half Mach numbers at which point water-air ratios reach 17 or 18 percent and liquid specific impulse is reduced to some 390 to 470 seconds, a level about equal to the impulse of a high energy rocket engine. The envelope can be further extended, but only with increasing sacrifices in liquid specific impulse. Oxygen-airflow ratios as high as 15 percent were investigated for increasing thrust. Using 15 percent oxygen in combination with water injection at high supersonic Mach numbers resulted in thrust augmentation as high as 76 percent without any significant decrease in liquid specific impulse. The stoichiometric afterburner exit temperature increased with increasing oxygen flow, reaching 4822 deg R in the turbojet engine at a Mach number of 3.5. At the transonic Mach number of 0.95 where no water injection is needed, an oxygen-air ratio of 15 percent increased thrust by some 55 percent in both engines, along with a decrease in liquid specific impulse of 62 percent. Afterburner temperature was approximately 4700 deg R at this high thrust condition. Water and/or oxygen injection are simple and straightforward strategies to improve engine performance and they will add little to engine weight. However, if large Mach number and thrust increases are required, liquid flows become significant, so that operation at these conditions will necessarily be of short duration.

  1. Effects of zinc injection on electrochemical corrosion and cracking behavior of stainless steels in borated and lithiated high temperature water

    International Nuclear Information System (INIS)

    Wu Xinqiang; Liu Xiahe; Han Enhou; Ke Wei

    2014-01-01

    Zinc (Zn) injection water chemistry (ZWC) adopted in primary coolant system in pressurized water reactors (PWRs) is to reduce the radiation buildup as well as retard the corrosion degradation in high temperature pressurized water through improving the characteristics of oxide scales formed on components materials. However, Zn injection involved corrosion and cracking behavior and related mechanisms are still under discussion. The understanding of Zn-bearing oxide scale characteristics and their protective property is of significance to clarify the environmentally assisted material failure problems in PWRs power plants. In the present work, in-situ potentiodynamic polarization curves and electrochemical impedance spectra measurements in high temperature borated and lithiated water as well as ex-situ X-ray photoelectron spectroscopy analyses have been done to investigate the effects of temperature (R.T.-603 K), pH T value at 573 K (6.9-7.4) and Zn-injection concentration (0-150 ppb) on electrochemical corrosion behavior and oxide scale characteristics of nuclear-grade stainless steels. The protective property of oxide scales under Zn-free and Zn-injected conditions degraded with increasing temperature, with Cr-rich oxide layer playing a key role on retarding further corrosion. The composition of oxide scales appeared slightly pH T dependent: rich in chromites and ferrites at pH T =6.9 and pH T =7.4, respectively. The corrosion rate decreased significantly in the high pH T value solution with Zn injection due to the formation of thin and compact oxide scales. The ≤50 ppb Zn injection could significantly affect the formation of Zn-bearing oxides on the surfaces, while >50 ppb Zn injection showed no obvious influence on the oxide scales. A modified point defect model was proposed to discuss the effects of injected Zn concentrations on the oxide scales in high temperature water. A 10 ppb Zn injection obviously decreased the intergranular cracking susceptibility of

  2. Stable water isotope patterns in a climate change hotspot: the isotope hydrology framework of Corsica (western Mediterranean).

    Science.gov (United States)

    van Geldern, Robert; Kuhlemann, Joachim; Schiebel, Ralf; Taubald, Heinrich; Barth, Johannes A C

    2014-06-01

    The Mediterranean is regarded as a region of intense climate change. To better understand future climate change, this area has been the target of several palaeoclimate studies which also studied stable isotope proxies that are directly linked to the stable isotope composition of water, such as tree rings, tooth enamel or speleothems. For such work, it is also essential to establish an isotope hydrology framework of the region of interest. Surface waters from streams and lakes as well as groundwater from springs on the island of Corsica were sampled between 2003 and 2009 for their oxygen and hydrogen isotope compositions. Isotope values from lake waters were enriched in heavier isotopes and define a local evaporation line (LEL). On the other hand, stream and spring waters reflect the isotope composition of local precipitation in the catchment. The intersection of the LEL and the linear fit of the spring and stream waters reflect the mean isotope composition of the annual precipitation (δP) with values of-8.6(± 0.2) ‰ for δ(18)O and-58(± 2) ‰ for δ(2)H. This value is also a good indicator of the average isotope composition of the local groundwater in the island. Surface water samples reflect the altitude isotope effect with a value of-0.17(± 0.02) ‰ per 100 m elevation for oxygen isotopes. At Vizzavona Pass in central Corsica, water samples from two catchments within a lateral distance of only a few hundred metres showed unexpected but systematic differences in their stable isotope composition. At this specific location, the direction of exposure seems to be an important factor. The differences were likely caused by isotopic enrichment during recharge in warm weather conditions in south-exposed valley flanks compared to the opposite, north-exposed valley flanks.

  3. Reverse flow injection spectrophotometric determination of thiram and nabam fungicides in natural water samples

    International Nuclear Information System (INIS)

    Asghar, M.; Yaqoob, M.; Nabi, A.

    2014-01-01

    A reverse flow injection (rFI) spectrophotometric method is reported for determination of thiram and nabam fungicides in natural water samples. The method is based on the reduction of iron(III) in the presence of thiram/nabam in acidic medium at 60 degree C and formation of iron(II)-ferricyanide complex was measured at 790 nm. The limits of detection (3s blank) were 0.01 and 0.05 micro g mL1 for thiram and nabam respectively with a sample throughput of 60 h1. Calibration graphs were linear over the range of 0.02 - 8.0 micro g mL1 (R2 = 0.9999, n = 8) and 0.1 - 30 micro g mL1 (R2 = 0.9982, n = 10) for thiram and nabam with relative standard deviations (RSDs; n = 3) in the range of 0.8 - 1.6% respectively. Experimental parameters and potential interferences were examined. Thiram and nabam were determined in natural water samples using solid-phase extraction (SPE) procedure and recoveries were in the range of 93+-3 - 105+-2% and 87+-4 - 102+-3% respectively. The results obtained were not significantly different compared with a HPLC method. (author)

  4. A multisyringe flow injection method for the determination of thorium in water samples using spectrophotometric detection

    International Nuclear Information System (INIS)

    Guzman-Mar, J.L.; Aracely Hernandez-Ramirez; Lopez-Chuken, U.J.; Lopez-de-Alba, P.L.; Victor Cerda

    2011-01-01

    A fast and simple multisyringe flow injection analysis (MSFIA) method for routine determination of thorium in water samples was developed. The methodology was based on the complexation reaction of thorium with arsenazo (III) at pH 2.0. Thorium concentrations were spectrophotometrically detected at 665 nm. Under optimal conditions, Beer's law was obeyed over the range from 0.2 to 4.5 μg mL -1 thorium, a 3σ detection limit of 0.05 μg mL -1 , and a 10σ quantification limit of 0.2 μg mL -1 were obtained. The relative standard deviations (RSD, %) at 0.5, 2.5 and 4.5 μg mL -1 was 2.8, 1.5 and 0.8%, respectively (n = 10). It was found that most of the common metal ions and anions did not interfere with the thorium determination. The proposed method was successfully applied to its analysis in various water samples. (author)

  5. Determination of Nitrite and Nitrate in Natural Waters Using Flow Injection with Spectrophotometric Detection

    International Nuclear Information System (INIS)

    Yaqoob, M.; Nabi, A.

    2013-01-01

    A simple and sensitive flow injection spectrophotometric method is reported for the room temperature determination of nitrite and nitrate based on the Griess reaction and a copperised cadmium column for reduction of nitrate. Calibration graphs were linear over the range 2 - 1000 micro g N L /sup -1/ (R2 = 0.9997 and 0.9999, n = 9) with a limit of detection (3 s.d.) of 1.0 micro g N L and relative standard deviations (n = 10) of 0.9 and 1.2% for 50 micro g N L nitrite and nitrate respectively. The sample throughput was 50 h. The effect of reagent concentrations, physical parameters (flow rate, sample volume, reaction coil and copperised cadmium column length) and the potential interferences are reported. The effect of salinity on the blank and on the determination of nitrite and nitrate are also presented. The method was applied to natural waters (rainwater, freshwater and estuarine water) and the results for nitrite + nitrate (140 - 7310 micro g N L/sup -1/) were not significantly different (95% confidence interval) from results obtained using a segmented flow analyser reference method with spectrophotometric detection. (author)

  6. Understanding the circulation of geothermal waters in the Tibetan Plateau using oxygen and hydrogen stable isotopes

    International Nuclear Information System (INIS)

    Tan, Hongbing; Zhang, Yanfei; Zhang, Wenjie; Kong, Na; Zhang, Qing; Huang, Jingzhong

    2014-01-01

    Highlights: • Unique geothermal resources in Tibetan Plateau were discussed. • Isotopes were used to trace circulation of geothermal water. • Magmatic water mixing dominates geothermal water evolution. - Abstract: With the uplift of the Tibetan Plateau, many of the world’s rarest and most unique geothermal fields have been developed. This study aims to systematically analyze the characteristics of the hydrogen and oxygen isotopic data of geothermal, river, and lake waters to understand the circulation of groundwater and to uncover the mechanism of geothermal formation in the Tibetan Plateau. Field observations and isotopic data show that geothermal water has higher temperatures and hydraulic pressures, as well as more depleted D and 18 O isotopic compositions than river and lake waters. Thus, neither lakes nor those larger river waters are the recharge source of geothermal water. Snow-melt water in high mountains can vertically infiltrate and deeply circulate along some stretching tensile active tectonic belts or sutures and recharge geothermal water. After deep circulation, cold surface water evolves into high-temperature thermal water and is then discharged as springs at the surface again in a low area, under high water-head difference and cold–hot water density difference. Therefore, the large-scale, high-temperature, high-hydraulic-pressure geothermal systems in the Tibetan Plateau are developed and maintained by rapid groundwater circulation and the heat source of upwelled residual magmatic water. Inevitably, the amount of geothermal water will increase if global warming accelerates the melting of glaciers in high mountains

  7. Investigating hydraulic connections and the origin of water in a mine tunnel using stable isotopes and hydrographs

    International Nuclear Information System (INIS)

    Walton-Day, Katherine; Poeter, Eileen

    2009-01-01

    Turquoise Lake is a water-supply reservoir located north of the historic Sugarloaf Mining district near Leadville, Colorado, USA. Elevated water levels in the reservoir may increase flow of low-quality water from abandoned mine tunnels in the Sugarloaf District and degrade water quality downstream. The objective of this study was to understand the sources of water to Dinero mine drainage tunnel and evaluate whether or not there was a direct hydrologic connection between Dinero mine tunnel and Turquoise Lake from late 2002 to early 2008. This study utilized hydrograph data from nearby draining mine tunnels and the lake, and stable isotope (δ 18 O and δ 2 H) data from the lake, nearby draining mine tunnels, imported water, and springs to characterize water sources in the study area. Hydrograph results indicate that flow from the Dinero mine tunnel decreased 26% (2006) and 10% (2007) when lake elevation (above mean sea level) decreased below approximately 3004 m (approximately 9855 feet). Results of isotope analysis delineated two meteoric water lines in the study area. One line characterizes surface water and water imported to the study area from the western side of the Continental Divide. The other line characterizes groundwater including draining mine tunnels, springs, and seeps. Isotope mixing calculations indicate that water from Turquoise Lake or seasonal groundwater recharge from snowmelt represents approximately 10% or less of the water in Dinero mine tunnel. However, most of the water in Dinero mine tunnel is from deep groundwater having minimal isotopic variation. The asymmetric shape of the Dinero mine tunnel hydrograph may indicate that a limited mine pool exists behind a collapse in the tunnel and attenutates seasonal recharge. Alternatively, a conceptual model is presented (and supported with MODFLOW simulations) that is consistent with current and previous data collected in the study area, and illustrates how fluctuating lake levels change the local

  8. Investigating hydraulic connections and the origin of water in a mine tunnel using stable isotopes and hydrographs

    Science.gov (United States)

    Walton-Day, Katherine; Poeter, Eileen

    2009-01-01

    Turquoise Lake is a water-supply reservoir located north of the historic Sugarloaf Mining district near Leadville, Colorado, USA. Elevated water levels in the reservoir may increase flow of low-quality water from abandoned mine tunnels in the Sugarloaf District and degrade water quality downstream. The objective of this study was to understand the sources of water to Dinero mine drainage tunnel and evaluate whether or not there was a direct hydrologic connection between Dinero mine tunnel and Turquoise Lake from late 2002 to early 2008. This study utilized hydrograph data from nearby draining mine tunnels and the lake, and stable isotope (δ18O and δ2H) data from the lake, nearby draining mine tunnels, imported water, and springs to characterize water sources in the study area. Hydrograph results indicate that flow from the Dinero mine tunnel decreased 26% (2006) and 10% (2007) when lake elevation (above mean sea level) decreased below approximately 3004 m (approximately 9855 feet). Results of isotope analysis delineated two meteoric water lines in the study area. One line characterizes surface water and water imported to the study area from the western side of the Continental Divide. The other line characterizes groundwater including draining mine tunnels, springs, and seeps. Isotope mixing calculations indicate that water from Turquoise Lake or seasonal groundwater recharge from snowmelt represents approximately 10% or less of the water in Dinero mine tunnel. However, most of the water in Dinero mine tunnel is from deep groundwater having minimal isotopic variation. The asymmetric shape of the Dinero mine tunnel hydrograph may indicate that a limited mine pool exists behind a collapse in the tunnel and attenutates seasonal recharge. Alternatively, a conceptual model is presented (and supported with MODFLOW simulations) that is consistent with current and previous data collected in the study area, and illustrates how fluctuating lake levels change the local water

  9. Hydrogeochemical and stable isotopic investigations on CO2-rich mineral waters from Harghita Mts. (Eastern Carpathians, Romania)

    Science.gov (United States)

    Kis, Boglárka-Mercedesz; Baciu, Călin; Kármán, Krisztina; Kékedy-Nagy, Ladislau; Francesco, Italiano

    2013-04-01

    There is a worldwide interest on geothermal, mineral and groundwater as a resource for energy, drinking water supply and therapeutic needs. The increasing trend in replacing tap water with commercial bottled mineral water for drinking purposes has become an economic, hydrogeologic and medical concern in the last decades. Several investigations have been carried out worldwide on different topics related to geothermal and mineral waters, dealing with mineral water quality assessment, origin of geothermal and mineral waters, geochemical processes that influence water chemistry and water-rock interaction In Romania, the Călimani-Gurghiu-Harghita Neogene to Quaternary volcanic chain (Eastern Carpathians) is one of the most important areas from the point of view of CO2-rich mineral waters. These mineral water springs occur within other post-volcanic phenomena like dry CO2 emissions, moffettes, bubbling pools, H2S gas emissions etc. Mineral waters from this area are used for bottling, local spas and drinking purposes for local people. The number of springs, around 2000 according to literature data, shows that there is still a significant unexploited potential for good quality drinking water in this area. Within the youngest segment of the volcanic chain, the Harghita Mts., its volcaniclastic aprons and its boundary with the Transylvanian Basin, we have carried out an investigation on 23 CO2-rich mineral water springs from a hydrogeochemical and stable isotopic point of view. The mineral waters are Ca-Mg-HCO3 to Na-Cl type. Sometimes mixing between the two types can be observed. We have detected a great influence of water-rock interaction on the stable isotopic composition of the mineral waters, shown by isotopic shifts to the heavier oxygen isotope, mixing processes between shallow and deeper aquifers and local thermal anomalies. Acknowledgements: The present work was financially supported by the Romanian National Research Council, Project PN-II-ID-PCE-2011-3-0537 and by

  10. p-Type Transparent Conducting Oxide/n-Type Semiconductor Heterojunctions for Efficient and Stable Solar Water Oxidation.

    Science.gov (United States)

    Chen, Le; Yang, Jinhui; Klaus, Shannon; Lee, Lyman J; Woods-Robinson, Rachel; Ma, Jie; Lum, Yanwei; Cooper, Jason K; Toma, Francesca M; Wang, Lin-Wang; Sharp, Ian D; Bell, Alexis T; Ager, Joel W

    2015-08-05

    Achieving stable operation of photoanodes used as components of solar water splitting devices is critical to realizing the promise of this renewable energy technology. It is shown that p-type transparent conducting oxides (p-TCOs) can function both as a selective hole contact and corrosion protection layer for photoanodes used in light-driven water oxidation. Using NiCo2O4 as the p-TCO and n-type Si as a prototypical light absorber, a rectifying heterojunction capable of light driven water oxidation was created. By placing the charge separating junction in the Si using a np(+) structure and by incorporating a highly active heterogeneous Ni-Fe oxygen evolution catalyst, efficient light-driven water oxidation can be achieved. In this structure, oxygen evolution under AM1.5G illumination occurs at 0.95 V vs RHE, and the current density at the reversible potential for water oxidation (1.23 V vs RHE) is >25 mA cm(-2). Stable operation was confirmed by observing a constant current density over 72 h and by sensitive measurements of corrosion products in the electrolyte. In situ Raman spectroscopy was employed to investigate structural transformation of NiCo2O4 during electrochemical oxidation. The interface between the light absorber and p-TCO is crucial to produce selective hole conduction to the surface under illumination. For example, annealing to produce more crystalline NiCo2O4 produces only small changes in its hole conductivity, while a thicker SiOx layer is formed at the n-Si/p-NiCo2O4 interface, greatly reducing the PEC performance. The generality of the p-TCO protection approach is demonstrated by multihour, stable, water oxidation with n-InP/p-NiCo2O4 heterojunction photoanodes.

  11. Stable isotopic study of soil water from the WIPP site: Constraints on the origin of water in the Rustler Fm, Delaware Basin, NM

    International Nuclear Information System (INIS)

    Campbell, A.R.; Vanlandingham, R.J.; Phillips, F.M.

    1992-01-01

    The Rustler Fm. overlies the salt beds in Salado Fm. in which the Waste Isolation Pilot Plant is being developed. The water in the Rustler Fm. aquifers have been the subject of various studies, including stable isotopes. Lambert and Harvey note that the Rustler waters all have δD below -43% whereas the other young ground waters in the region have δD's above 41%. They conclude that the water in the Rustler is not from modern recharge but is fossil water from a past climatic regime. Chapman on the other hand concludes that waters on Carlsbad Caverns are isotopically heavier than the Rustler water due to cave evaporation, and thus the Rustler water could be from modern recharge. The two different interpretations have very different implications for the hydrological characterization of the WIPP site. In order to further study this issue the authors have collected six shallow cores from the unconsolidated sand in the vicinity of WIPP. Water was extracted from each sample by vacuum distillation. For these samples the projected meteoric waters would have δD values in the range of -45 to -55%. This falls well within the range of the δD values for the Rustler Fm. From this the author concludes that the Rustler water could result from modern precipitation, although not from infiltration through a soil where evaporation is active. Soil waters may provide important isotopic constraints on the origins of water in regional aquifer systems

  12. An inexpensive and stable LED Sun photometer for measuring the water vapor column over South Texas from 1990 to 2001

    Science.gov (United States)

    Mims, Forrest M.

    2002-07-01

    A Sun photometer that uses near-infrared light-emitting diodes (LEDs) as spectrally-selective photodetectors has measured total column water vapor in South Texas since February 1990. The 12 years of solar noon observations to date are correlated with upper air soundings at Del Rio, Texas (r2 = 0.75), and highly correlated with measurements by a Microtops II filter Sun photometer (r2 = 0.94). LEDs are inexpensive and have far better long term stability than the interference filters in conventional Sun photometers. The LED Sun photometer therefore provides an inexpensive, stable and portable means for measuring column water vapor.

  13. Estimate for interstage water injection in air compressor incorporated into gas-turbine cycles and combined power plants cycles

    Science.gov (United States)

    Kler, A. M.; Zakharov, Yu. B.; Potanina, Yu. M.

    2017-05-01

    The objects of study are the gas turbine (GT) plant and combined cycle power plant (CCPP) with opportunity for injection between the stages of air compressor. The objective of this paper is technical and economy optimization calculations for these classes of plants with water interstage injection. The integrated development environment "System of machine building program" was a tool for creating the mathematic models for these classes of power plants. Optimization calculations with the criterion of minimum for specific capital investment as a function of the unit efficiency have been carried out. For a gas-turbine plant, the economic gain from water injection exists for entire range of power efficiency. For the combined cycle plant, the economic benefit was observed only for a certain range of plant's power efficiency.

  14. Stable isotope composition of environmental water and food products as a tracer of origin

    International Nuclear Information System (INIS)

    Wierzchnicki, R.; Owczarczyk, A.; Soltyk, W.

    2004-01-01

    The paper is the review of Institute of Nuclear Chemistry and Technology (INCT) activity in application of stable isotope ratios (especially D/H and 18 O/ 16 O) for environmental studies and food origin control. INCT has at disposal since 1998, a high class instrument - Isotope Ratio Mass Spectrometer, Delta Plus, Finnigan MAT, Germany - suitable to perform such measurements. (author)

  15. Stable isotopes use in hydrogeology studies of mineral and thermal waters (Lindoia region, Sao Paulo, Brazil)

    International Nuclear Information System (INIS)

    Yoshinaga, S.; Silva, A.A.K. de; Matsui, E.

    1991-01-01

    Deuterium and oxygen-18 studies were used to investigate the origin and the mineralizing processes of the mineral water and thermal water in Aguas de Lindoia and Lindoia, Brazilian municipal districts. (M.V.M.)

  16. Studies on the electrochemical disinfection of water containing Escherichia coli using a Dimensionally Stable Anode

    Directory of Open Access Journals (Sweden)

    Isabel Celeste Caíres Pereira Gusmão

    2010-10-01

    Full Text Available The aim of this work was to investigate the disinfectant effect of electrolysis on chlorine-free water, artificially contaminated with Escherichia coli (CCT-1457 and to evaluate the bactericidal activity of electrolysis and kinetic behavior of a single-cell reactor, with a DSA (Dimensionally Stable Anode electrode to develop a scaled-up system. A high-density E. coli suspension (10(6 CFU mL-1 was electrolyzed in this reactor at 25, 50 and 75 mA cm-2 for up to 60 min, at flow rates of 200 and 500 L h-1. Bacterial survival fell by 98.9% without addition of chlorinated compounds and a power consumption rate not more than 5.60 kWh m-3 at flow rate of 200 L h-1 and 75 mA cm-2. The process produced a germicidal effect that reached this inactivation rate within a relatively short contact time. Also, a solution of electrolyzed 0.08 M Na2SO4 added to the inoculum showed residual bactericidal effect. The efficiency of disinfection was regulated by both the contact time and current density applied, and a kinetic function for the survival rate was developed for the purpose of scaling up.Água contaminada é uma das maiores origens de doenças em seres humanos. Em todo o mundo, a cloração é o método mais utilizado para promover desinfecção em águas de abastecimento devido ao seu efeito residual, quando adequadamente calculado. Contudo, se a água apresentar matéria orgânica, pode haver a geração de organoclorados, os quais são genotóxicos e carcinogênicos. Sob esta óptica, investigamos o efeito bactericida da aplicação da eletrólise em água sem cloro contaminada com Escherichia coli (CCT-1457. O objetivo deste estudo foi avaliar o poder de desinfecção e o comportamento cinético da eletrólise realizada em reator de compartimento único e usando eletrodos ADE (Anodo Dimensionalmente Estável, visando ampliação de escala. Uma suspensão contendo elevada concentração de E. coli (10(6 UFC mL-1 foi submetida ao tratamento no reator em 25

  17. High-resolution stable isotope monitoring reveals differential vegetation-soil water feedbacks among plant functional types

    Science.gov (United States)

    Volkmann, T. H. M.; Haberer, K.; Troch, P. A. A.; Gessler, A.; Weiler, M.

    2016-12-01

    Understanding the linked dynamics of rain water recharge to soils and its utilization by plants is critical for predicting the impact of climate and land use changes on the productivity of ecosystems and the hydrologic cycle. While plants require vast quantities of water from the soil to sustain growth and function, they exert important direct and indirect controls on the movement of water through the rooted soil horizons, thereby potentially affecting their own resource availability. However, the specific ecohydrological belowground processes associated with different plant types and their rooting systems have been difficult to quantify with traditional methods. Here, we report on the use of techniques for monitoring stable isotopes in soil and plant water pools that allow us to track water infiltration and root uptake dynamics non-destructively and in high resolution. The techniques were applied in controlled rain pulse experiments with distinct plant types (grass, deciduous trees, grapevine) that we let develop on an initially uniform soil for two years. Our results show that plant species and types differed widely in their plasticity and pattern of root uptake under variable water availability. Thereby, and through notably co-acting indirect effects related to differential root system traits and co-evolution of soil properties, the different plants induced contrasting hydrological dynamics in the soil they had inhabited for only a short period of time. Taken together, our data suggest that the studied soil-vegetation systems evolved a positive infiltration-uptake feedback in which hydrological flow pathways underlying different species diverged in a way that complemented their specific water utilization strategy. Such a feedback could present an indirect competitive mechanism by which plants improve their own water supply and modulate hydrological cycling at the land surface. The ability to directly measure this feedback using in situ isotope methodology

  18. Spectral analysis software improves confidence in plant and soil water stable isotope analyses performed by isotope ratio infrared spectroscopy (IRIS).

    Science.gov (United States)

    West, A G; Goldsmith, G R; Matimati, I; Dawson, T E

    2011-08-30

    Previous studies have demonstrated the potential for large errors to occur when analyzing waters containing organic contaminants using isotope ratio infrared spectroscopy (IRIS). In an attempt to address this problem, IRIS manufacturers now provide post-processing spectral analysis software capable of identifying samples with the types of spectral interference that compromises their stable isotope analysis. Here we report two independent tests of this post-processing spectral analysis software on two IRIS systems, OA-ICOS (Los Gatos Research Inc.) and WS-CRDS (Picarro Inc.). Following a similar methodology to a previous study, we cryogenically extracted plant leaf water and soil water and measured the δ(2)H and δ(18)O values of identical samples by isotope ratio mass spectrometry (IRMS) and IRIS. As an additional test, we analyzed plant stem waters and tap waters by IRMS and IRIS in an independent laboratory. For all tests we assumed that the IRMS value represented the "true" value against which we could compare the stable isotope results from the IRIS methods. Samples showing significant deviations from the IRMS value (>2σ) were considered to be contaminated and representative of spectral interference in the IRIS measurement. Over the two studies, 83% of plant species were considered contaminated on OA-ICOS and 58% on WS-CRDS. Post-analysis, spectra were analyzed using the manufacturer's spectral analysis software, in order to see if the software correctly identified contaminated samples. In our tests the software performed well, identifying all the samples with major errors. However, some false negatives indicate that user evaluation and testing of the software are necessary. Repeat sampling of plants showed considerable variation in the discrepancies between IRIS and IRMS. As such, we recommend that spectral analysis of IRIS data must be incorporated into standard post-processing routines. Furthermore, we suggest that the results from spectral analysis be

  19. Water uptake in woody riparian phreatophytes of the southwestern United States: a stable isotope study

    International Nuclear Information System (INIS)

    Busch, D.E.; Ingraham, N.L.; Smith, S.D.

    1992-01-01

    Alluvial forest associations are often dominated by woody phreatophytes, plants that are tightly linked to aquifers for water uptake. Anthropogenic hydrological alterations (e.g., water impoundment or diversion) are of clear importance to riparian ecosystem function. Because decreased frequency of flooding and depression of water tables may, in effect, sever riparian plants from their natural water sources, research was undertaken to determine water uptake patterns for the dominant native and introduced woody taxa of riparian plant communities of the southwestern United States. At floodplain study sites along the Bill Williams and lower Colorado Rivers (Arizona, USA), naturally occurring D and 18 O were used to distinguish among potential water sources. Isotopic ratios from potential uptake locations were compared to water extracted from the dominant woody taxa of the study area (Populus fremontii, Salix gooddingii, and Tamarix ramosissima) to elucidate patterns of water absorption. Isotopic composition of water obtained from sapwood cores did not differ significantly from heartwood or branch water, suggesting that heartwood water exchange, stem capacitance, and phloem sap mixing may be inconsequential in actively transpiring Salix and Populus. There was evidence for close hydrologic linkage of river, ground, and soil water during the early part of the growing season. Surface soils exhibited D enrichment due to cumulative exposure to evaporation as the growing season progressed. Isotopic ratios of water extracted from Populus and Salix did not exhibit isotopic enrichment and were not significantly different from groundwater or saturated soil water sources, indicating a phreatophytic uptake pattern. Associations of isotopic ratios with water relations parameters indicated high levels of canopy evaporation and possible use of moisture from unsaturated alluvial soils in addition to groundwater in Tamarix. (author)

  20. Multi-scale heterogeneity in the temporal origin of water taken up by trees water uptake inferred using stable isotopes

    Science.gov (United States)

    Allen, S. T.; Kirchner, J. W.; Braun, S.; Siegwolf, R. T.; Goldsmith, G. R.

    2017-12-01

    Xylem water isotopic composition can reveal how water moves through soil and is subsequently taken up by plants. By examining how xylem water isotopes vary across distinct climates and soils, we test how these site characteristics control critical-zone water movement and tree uptake. Xylem water was collected from over 900 trees at 191 sites across Switzerland during a 10-day period in mid-summer 2015. Sites contained oak, beech and/or spruce trees and ranged in elevation from 260 to 1870 m asl with mean annual precipitation from 700 to 2060 mm. Xylem water samples were analyzed for 2H and 18O using isotope ratio mass spectrometry. Patterns in the temporal origin of xylem water showed regional differences. For example, trees in the southern and alpine regions had xylem water isotopic signatures that more closely resembled summer precipitation. The isotopic spatial range observed for mid-summer xylem waters was similar to the seasonal range of precipitation; that is, mid-summer xylem water at some sites resembled summer precipitation, and at other sites resembled winter precipitation. Xylem water from spruces, oaks, and beeches at the same sites did not differ from each other, despite these species having different rooting habits. Across all sites and species, precipitation amount correlated positively with xylem δ18O. In higher-precipitation areas, summer rain apparently displaces or mixes with older (winter) stored waters, thus reducing the winter-water isotopic signal in xylem water. Alternatively, in areas with limited precipitation, xylem water more closely matched winter water, indicating greater use of older stored water. We conclude that regional variations in precipitation deficits determine variations in the turnover rate of plant-available soil water and storage.

  1. Interactive Effects of CO2 Concentration and Water Regime on Stable Isotope Signatures, Nitrogen Assimilation and Growth in Sweet Pepper

    Directory of Open Access Journals (Sweden)

    María D. Serret

    2018-01-01

    Full Text Available Sweet pepper is among the most widely cultivated horticultural crops in the Mediterranean basin, being frequently grown hydroponically under cover in combination with CO2 fertilization and water conditions ranging from optimal to suboptimal. The aim of this study is to develop a simple model, based on the analysis of plant stable isotopes in their natural abundance, gas exchange traits and N concentration, to assess sweet pepper growth. Plants were grown in a growth chamber for near 6 weeks. Two [CO2] (400 and 800 μmol mol−1, three water regimes (control and mild and moderate water stress and four genotypes were assayed. For each combination of genotype, [CO2] and water regime five plants were evaluated. Water stress applied caused significant decreases in water potential, net assimilation, stomatal conductance, intercellular to atmospheric [CO2], and significant increases in water use efficiency, leaf chlorophyll content and carbon isotope composition, while the relative water content, the osmotic potential and the content of anthocyanins did change not under stress compared to control conditions support this statement. Nevertheless, water regime affects plant growth via nitrogen assimilation, which is associated with the transpiration stream, particularly at high [CO2], while the lower N concentration caused by rising [CO2] is not associated with stomatal closure. The stable isotope composition of carbon, oxygen, and nitrogen (δ13C, δ18O, and δ15N in plant matter are affected not only by water regime but also by rising [CO2]. Thus, δ18O increased probably as response to decreases in transpiration, while the increase in δ15N may reflect not only a lower stomatal conductance but a higher nitrogen demand in leaves or shifts in nitrogen metabolism associated with decreases in photorespiration. The way that δ13C explains differences in plant growth across water regimes within a given [CO2], seems to be mediated through its direct

  2. Caution on the storage of waters and aqueous solutions in plastic containers for hydrogen and oxygen stable isotope analysis.

    Science.gov (United States)

    Spangenberg, Jorge E

    2012-11-30

    The choice of containers for storage of aqueous samples between their collection, transport and water hydrogen ((2)H) and oxygen ((18)O) stable isotope analysis is a topic of concern for a wide range of fields in environmental, geological, biomedical, food, and forensic sciences. The transport and separation of water molecules during water vapor or liquid uptake by sorption or solution and the diffusive transport of water molecules through organic polymer material by permeation or pervaporation may entail an isotopic fractionation. An experiment was conducted to evaluate the extent of such fractionation. Sixteen bottle-like containers of eleven different organic polymers, including low and high density polyethylene (LDPE and HDPE), polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET), and perfluoroalkoxy-Teflon (PFA), of different wall thickness and size were completely filled with the same mineral water and stored for 659 days under the same conditions of temperature and humidity. Particular care was exercised to keep the bottles tightly closed and prevent loss of water vapor through the seals. Changes of up to +5‰ for δ(2)H values and +2.0‰ for δ(18)O values were measured for water after more than 1 year of storage within a plastic container, with the magnitude of change depending mainly on the type of organic polymer, wall thickness, and container size. The most important variations were measured for the PET and PC bottles. Waters stored in glass bottles with Polyseal™ cone-lined PP screw caps and thick-walled HDPE or PFA containers with linerless screw caps having an integrally molded inner sealing ring preserved their original δ(2)H and δ(18)O values. The carbon, hydrogen, and oxygen stable isotope compositions of the organic polymeric materials were also determined. The results of this study clearly show that for precise and accurate measurements of the water stable isotope composition in aqueous solutions, rigorous sampling and

  3. Numerical simulation of MH growth/dissociation by hot water injection on the Lab. experiment

    Science.gov (United States)

    Temma, N.; Sakamoto, Y.; Komai, T.; Yamaguchi, T.; Pawar, R.; Zyvoloski, G.

    2005-12-01

    Methane Hydrate (MH) is considered to be one of the new-generation energy resources. Aiming to develop the method of extraction of methane gas from MH, laboratory experiments have been performed in order to grasp the MH property in the National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba in Japan. In this paper, we present the results of the numerical simulation of experiment using by the hot water injection. In this calculation, FEHM (Finite Element Heat and Mass transfer) code is used. This code is developed at Los Alamos National Laboratory. In this experiment, temperature, pressure and cumulative gas production were measured. From these data, we suppose that MH growth/dissociation occurred by the flow of the hot water. And we make the model of the growth/dissociation. As this model consist of many parameters, it is difficult to determine parameters. Thus, we use PEST (Parameter ESTimation ) in order to determine parameters for the model of the MH growth/ dissociation. We use temperature data of experiment, as observed data. We make two observed data sets at the beginning and later term of experiment. At the results of PEST, we obtain two sets of parameters to get good match the observed data. We think that these sets indicate both the maximum and the minimum values of the MH growth/dissociation model. And, on this range, we continue to calculate until we get the good match. Finally, we obtain the numerical model of the experiment. Also, we conducted the sensitive analysis for the MH growth/ dissociation using this model.

  4. Spatial distribution and controlling factors of stable isotopes in meteoric waters on the Tibetan Plateau: Implications for paleoelevation reconstruction

    Science.gov (United States)

    Li, Lin; Garzione, Carmala N.

    2017-02-01

    Debates persist about the interpretations of stable isotope based proxies for the surface uplift of the central-northern Tibetan Plateau. These disputes arise from the uncertain relationship between elevation and the δ18 O values of meteoric waters, based on modern patterns of isotopes in precipitation and surface waters. We present a large river water data set (1,340 samples) covering most parts of the Tibetan Plateau to characterize the spatial variability and controlling factors of their isotopic compositions. Compared with the amount-weighted mean annual oxygen isotopic values of precipitation, we conclude that river water is a good substitute for isotopic studies of precipitation in the high flat (e.g., elevation >3,300 m) interior of the Tibetan Plateau in the mean annual timescale. We construct, for the first time based on field data, contour maps of isotopic variations of meteoric waters (δ18 O, δD and d-excess) on the Tibetan Plateau. In the marginal mountainous regions of the Plateau, especially the southern through eastern margins, the δ18 O and δD values of river waters decrease with increasing mean catchment elevation, which can be modeled as a Rayleigh distillation process. However, in the interior of the Plateau, northward increasing trends in δ18 O and δD values are pronounced and present robust linear relations; d-excess values are lower than the marginal regions and exhibit distinct contrasts between the eastern (8 ‰- 12 ‰) and western (Asian monsoon and Westerly winds; 2) contribution of moisture from recycled surface water; and 3) sub-cloud evaporation. We further provide a sub-cloud evaporation modified Rayleigh distillation and mixing model to simulate the isotopic variations in the western Plateau. Results of this work suggest that stable isotope-based paleoaltimetry studies are reliable in the southern through eastern Plateau margins; towards the central-northern Plateau, this method cannot be applied without additional

  5. A method for speciation of trace elements (stable and radioactive) in natural waters

    International Nuclear Information System (INIS)

    Salbu, B.; Bjornstad, H.E.; Pappas, A.C.

    1985-01-01

    Radioactive nuclides and stable trace metals entering natural aquatic systems interact with naturally occurring particles through exchange and sorption processes. The extent of which depends not only on the elements and particles in question, but also on size distribution of particles being most pronounced for colloids having large surface areas to volume ratios. The interaction of radionuclides and trace metals with colloids changes their size and charge characteristics and thereby influences their transport, mobility and bioavailability

  6. An organic water-gated ambipolar transistor with a bulk heterojunction active layer for stable and tunable photodetection

    Science.gov (United States)

    Xu, Haihua; Zhu, Qingqing; Wu, Tongyuan; Chen, Wenwen; Zhou, Guodong; Li, Jun; Zhang, Huisheng; Zhao, Ni

    2016-11-01

    Organic water-gated transistors (OWGTs) have emerged as promising sensing architectures for biomedical applications and environmental monitoring due to their ability of in-situ detection of biological substances with high sensitivity and low operation voltage, as well as compatibility with various read-out circuits. Tremendous progress has been made in the development of p-type OWGTs. However, achieving stable n-type operation in OWGTs due to the presence of solvated oxygen in water is still challenging. Here, we report an ambipolar OWGT based on a bulk heterojunction active layer, which exhibits a stable hole and electron transport when exposed to aqueous environment. The device can be used as a photodetector both in the hole and electron accumulation regions to yield a maximum responsivity of 0.87 A W-1. More importantly, the device exhibited stable static and dynamic photodetection even when operated in the n-type mode. These findings bring possibilities for the device to be adopted for future biosensing platforms, which are fully compatible with low-cost and low-power organic complementary circuits.

  7. Contribution to the study of evaporation of natural water using stable isotope

    International Nuclear Information System (INIS)

    Takaki, T.

    1979-01-01

    Procedures for measurements of isotopic ratios in natural waters have been developed, in order to study evaporation mechanism in reservoirs, in laboratory scale. Rayleigh's model of evaporation is discussed, considering evaporation in the presence of atmospheric water vapor. The results obtained for the variation of the concentration of O 18 and D, in function of remaining water fraction for four evaporation reservoirs agree with the model presented and allow an estimation of the local average relative humidity. The straight-line equation that relates the results for the concentrations of O 18 and D in our samples is proper to water reservoirs subjected to a significant reduction in its volume by evaporation. The content of O 18 and D, in water prior the evaporation directly obtained from the intersection, of the meteoric with our line agree with the values measured for the water used to fill the reservoirs [pt

  8. Physicochemical characterization and an injection formulation study of water insoluble ZCVI₄-2, a novel NO-donor anticancer compound.

    Science.gov (United States)

    Gao, Yuan; Li, Li; Zhang, Jianjun; Su, Feng; Gong, Zhenhua; Lai, Yisheng; Zhang, Yihua

    2012-07-01

    ZCVI(4)-2 was a novel nitric oxide-releasing glycosyl derivative of oleanolic acid that displayed strong cytotoxicity selectively against human hepatocellular carcinoma in vitro and in vivo. In this study, ZCVI(4)-2 was characterized by FT-IR spectroscopy, differential scanning calorimetry, powder X-ray diffractometry, Raman spectroscopy, hygroscopicity and stability. A high performance liquid chromatography method was also established for the quantitative determination of solubility and additional stability profile of ZCVI(4)-2. ZCVI(4)-2 was found to be an amorphous and stable solid with low solubility of less than 10 μg/mL. Based on the solubilization tests that included methods of cosolvency and micellization, the solution mixture of 5% Solutol HS-15, 5% 1, 2-propylene glycol and 5% anhydrous ethanol was determined to be the system for the preparation of the ZCVI(4)-2 early injection solution. The effect of pH, temperature, light and injectable isotonic glucose or NaCl solution on ZCVI(4)-2 injection was also investigated. Good stability was observed at all testing conditions. Under the conditions studied, the NO-releasing rate and amount of ZCVI(4)-2 from the early injection solution in rat plasma demonstrated a promising therapeutic efficacy while maintaining a good safety profile.

  9. The relationship between stable oxygen and hydrogen isotope ratios of water in astomatal plants

    Science.gov (United States)

    Cooper, Lee W.; DeNiro, Michael J.; Keeley, Jon E.; Taylor, H. P.; O'Neil, J. R.; Kaplan, I.R.

    1991-01-01

    Isotropic fractination of leaf water during transpiration is influenced by both equilibrium and kinetic factors. Previous workers have predicted that the influence of each factor varies depending upon the path of water loss,m whether centralized through stomata, or diffuse through the cuticle. We studied the relationship between the δD and δ18O values of lead and stem waters of laurel sumac, Rhus laurina (Nutt.) T. & G., and its parasite, dodder, Cuscuta subinclusa D. & H., growing in the field. Stomatal transpiration, associated with more stagnant boundary layers, predominates in R. laurina; cuticular transpiration, associated with more turbulent boundary layers, is most important in the largely astomatal C. subinclusa. We also studied the diurnal variation in the δD and δ18O values of lead waters of two astomatal plants, Chiloschista lunifera (Rchb. F.) J.J.S. and Stylites andicola Amstutz, and two stomatal plants, Tillandsia balbisiana Schult. and Lilaeopsis schaffneriana (Schlecht.) C. & R., growing with them under the same conditions in the laboratory. Slopes, m, for the relation δD = mδ18O + b were significantly higher for stem waters in C. subinclusa that for leaf waters in R. laurina (1.77), consistent with the difference in the boundary layers through which water was lost in the two species. The magnitude of diurnal heavy isotope enrichment of tissue water was smaller in C. subinclusa than in R. laurina, which is also consistent with predictions concerning evapotranspiration through difference types of boundary layers. The slopes, m, in plant waters in the laboratory experiments, conducted at high humidity, were not different than those observed during evaporation of water from pans, regardless of plant anatomy. The observation suggests that cuticular transpiration is important in influencing isotopic fractionation of water only at low humidity. Our results indicate that the isotopic composition of water vapor released by plants in arid regions may

  10. Determination of Tree and Understory Water Sources and Residence Times Using Stable Isotopes in a Southern Appalachian Forest

    Science.gov (United States)

    Stewart, A. N.; Knoepp, J.; Miniat, C.; Oishi, A. C.; Emanuel, R. E.

    2017-12-01

    The development of accurate hydrologic models is key to describing changes in hydrologic processes due to land use and climate change. Hydrologic models typically simplify biological processes associated with plant water uptake and transpiration, assuming that roots take up water from the same moisture pool that feeds the stream; however, this assumption is not valid for all systems. Novel combinations of climate and forest composition and structure, caused by ecosystem succession, management decisions, and climate variability, will require a better understanding of sources of water for transpiration in order to accurately estimate impact on forest water yield. Here we examine red maple (Acer rubrum), rhododendron (Rhododendron maximum), tulip poplar (Liriodendron tulipifera), and white oak (Quercus alba) trees at Coweeta Hydrologic Laboratory, a long-term hydrological and ecological research site in western NC, USA, and explore whether source water use differs by species and landscape position. We analyzed stable isotopes of water (18O and 2H) in tree cores, stream water, soil water, and precipitation using laser spectrometry and compare the isotopic composition of the various pools. We place these results in broader context using meteorological and ecophysiological data collected nearby. These findings have implications for plant water stress and drought vulnerability. They also contribute to process-based knowledge of plant water use that better captures the sensitivity of transpiration to physical and biological controls at the sub-catchment scale. This work aims to help establish novel ways to model transpiration and improve understanding of water balance, biogeochemical cycling, and transport of nutrients to streams.

  11. Vapour explosions (fuel-coolant interactions) resulting from the sub-surface injection of water into molten metals: preliminary results

    International Nuclear Information System (INIS)

    Asher, R.C.; Bullen, D.; Davies, D.

    1976-03-01

    Preliminary experiments are reported on the relationship between the injection mode of contact and the occurrence and magnitude of vapour explosions. Water was injected beneath the surface of molten metals, chiefly tin at 250 to 900 0 C. Vapour explosions occurred in many, but not all, cases. The results are compared with Dullforce's observations (Culham Report (CLM-P424) on the dropping mode of contact and it appears that rather different behaviour is found; in particular, the present results suggest that the Temperature Interaction Zone is different for the two modes of contact. (author)

  12. Determination of human-use pharmaceuticals in filtered water by direct aqueous injection: high-performance liquid chromatography/tandem mass spectrometry

    Science.gov (United States)

    Furlong, Edward T.; Noriega, Mary C.; Kanagy, Christopher J.; Kanagy, Leslie K.; Coffey, Laura J.; Burkhardt, Mark R.

    2014-01-01

    This report describes a method for the determination of 110 human-use pharmaceuticals using a 100-microliter aliquot of a filtered water sample directly injected into a high-performance liquid chromatograph coupled to a triple-quadrupole tandem mass spectrometer using an electrospray ionization source operated in the positive ion mode. The pharmaceuticals were separated by using a reversed-phase gradient of formic acid/ammonium formate-modified water and methanol. Multiple reaction monitoring of two fragmentations of the protonated molecular ion of each pharmaceutical to two unique product ions was used to identify each pharmaceutical qualitatively. The primary multiple reaction monitoring precursor-product ion transition was quantified for each pharmaceutical relative to the primary multiple reaction monitoring precursor-product transition of one of 19 isotope-dilution standard pharmaceuticals or the pesticide atrazine, using an exact stable isotope analogue where possible. Each isotope-dilution standard was selected, when possible, for its chemical similarity to the unlabeled pharmaceutical of interest, and added to the sample after filtration but prior to analysis. Method performance for each pharmaceutical was determined for reagent water, groundwater, treated drinking water, surface water, treated wastewater effluent, and wastewater influent sample matrixes that this method will likely be applied to. Each matrix was evaluated in order of increasing complexity to demonstrate (1) the sensitivity of the method in different water matrixes and (2) the effect of sample matrix, particularly matrix enhancement or suppression of the precursor ion signal, on the quantitative determination of pharmaceutical concentrations. Recovery of water samples spiked (fortified) with the suite of pharmaceuticals determined by this method typically was greater than 90 percent in reagent water, groundwater, drinking water, and surface water. Correction for ambient environmental

  13. Stable and accurate methods for identification of water bodies from Landsat series imagery using meta-heuristic algorithms

    Science.gov (United States)

    Gamshadzaei, Mohammad Hossein; Rahimzadegan, Majid

    2017-10-01

    Identification of water extents in Landsat images is challenging due to surfaces with similar reflectance to water extents. The objective of this study is to provide stable and accurate methods for identifying water extents in Landsat images based on meta-heuristic algorithms. Then, seven Landsat images were selected from various environmental regions in Iran. Training of the algorithms was performed using 40 water pixels and 40 nonwater pixels in operational land imager images of Chitgar Lake (one of the study regions). Moreover, high-resolution images from Google Earth were digitized to evaluate the results. Two approaches were considered: index-based and artificial intelligence (AI) algorithms. In the first approach, nine common water spectral indices were investigated. AI algorithms were utilized to acquire coefficients of optimal band combinations to extract water extents. Among the AI algorithms, the artificial neural network algorithm and also the ant colony optimization, genetic algorithm, and particle swarm optimization (PSO) meta-heuristic algorithms were implemented. Index-based methods represented different performances in various regions. Among AI methods, PSO had the best performance with average overall accuracy and kappa coefficient of 93% and 98%, respectively. The results indicated the applicability of acquired band combinations to extract accurately and stably water extents in Landsat imagery.

  14. Distribution and utilization of 15N in cowpeas injected into the stem under influence of water deficit.

    Science.gov (United States)

    Götz K-P; Herzog, H

    2000-01-01

    Investigations were carried out on Vigna unguiculata L. Walp. to estimate the distribution and utilization of 15N in different organs after stem injection during vegetative, flowering and pod filling stage. During flowering effects of water deficit were also examined. In well watered plants, within 4 days after injection, 65% of 15N accumulated in leaves. This was drastically reduced to 42% by water deficit. 15N accumulation in stems increased under water deficit. The translocation of 15N from the stem base to roots were not altered by water deficit. During pod filling 62% of recovered 15N in the plants had accumulated in seeds, 24% in leaves and 11% in stems within 4 days, whereas the uptake of nitrogen in pod walls and roots remained low (2%). These results demonstrate that the method of injecting very small quantities (1 mg/plant) of 15N into the stem base allows an exact and detailed quantitative assessment of N translocation/distribution with regard to different organs, different growth stages and different treatments.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  16. Stable isotope compositions and water contents of boninite series volcanic rocks from Chichi-jima, Bonin Islands, Japan

    Science.gov (United States)

    Dobson, P.F.; O'Neil, J.R.

    1987-01-01

    Measurements of stable isotope compositions and water contents of boninite series volcanic rocks from the island of Chichi-jima, Bonin Islands, Japan, confirm that a large amount (1.6-2.4 wt.%) of primary water was present in these unusual magmas. An enrichment of 0.6??? in 18O during differentiation is explained by crystallization of 18O-depleted mafic phases. Silicic glasses have elevated ??18O values and relatively low ??D values indicating that they were modified by low-temperature alteration and hydration processes. Mafic glasses, on the other hand, have for the most part retained their primary isotopic signatures since Eocene time. Primary ??D values of -53 for boninite glasses are higher than those of MORB and suggest that the water was derived from subducted oceanic lithosphere. ?? 1987.

  17. Determination of groundwater travel time in a karst aquifer by stable water isotopes, Tanour and Rasoun spring (Jordan)

    Science.gov (United States)

    Hamdan, Ibraheem; Wiegand, Bettina; Sauter, Martin; Ptak, Thomas

    2016-04-01

    Key words: karst aquifers, stable isotopes, water travel time, Jordan. Tanour and Rasoun karst springs are located about 75 kilometers northwest of the city of Amman in Jordan. The aquifer is composed of Upper Cretaceous limestone that exhibits a moderate to high degree of karstification. The two springs represent the main drinking water resources for the surrounding villages. The yearly water production is about 1,135,000 m3/yr for Tanour spring and 125,350 m3/yr for Rasoun spring (MWI 2015). Due to contamination from microbiological pollution (leakage of wastewater from septic tanks) or infiltration of wastewater from local olive presses, drinking water supply from the two springs is frequently interrupted. From November 2014 through March 2015, spring water samples were collected from Tanour and Rasoun spring for the analysis of stable hydrogen and oxygen isotopes to investigate spring response to precipitation and snowmelt events. Both Tanour and Rasoun spring show a fast response to precipitation and snowmelt events, implying short water travel times. Based on the variation of δ 18O and δ 2H in spring discharge, the average maximum water travel time is in the order of 8 days for Tanour spring and 6 days for Rasoun spring. Due to fast water travel times, Tanour and Rasoun spring can be considered as highly vulnerable to pollutants. δ 18O and δ 2H values of Tanour and Rasoun springs parallel other monitored parameter like water temperature, turbidity, electrical conductivity and spring discharge. In addition, a high turbidity peak was monitored in Tanour spring during a pollution event from olive mills wastewater (Hamdan et al., 2016; Hamdan, in prep.). The fast response in both Tanour and Rasoun springs to precipitation events requires monitoring potential sources of pollution within the catchment area. References: MWI (Ministry of Water and Irrigation) (2015) Monthly Production values for Tanour and Rasoun Springs for the time period between 1996 and 2014

  18. Stable isotopes of hydrogen and oxygen in surface water and ground water at selected sites on or near the Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Ott, D.S.; Cecil, L.D.; Knobel, L.L.

    1994-01-01

    Relative stable isotopic ratios for hydrogen and oxygen compared to standard mean ocean water are presented for water from 4 surface-water sites and 38 ground-water sites on or near the Idaho National Engineering Laboratory (INEL). The surface-water samples were collected monthly from March 1991 through April 1992 and after a storm event on June 18, 1992. The ground-water samples either were collected during 1991 or 1992. These data were collected as part of the US Geological Survey's continuing hydrogeological investigations at the INEL. The relative isotopic ratios of hydrogen and oxygen are reported as delta 2 H (δ 2 H) and as delta 18 O (δ 18 O), respectively. The values of δ 2 H and δ 18 O in water from the four surface-water sites ranged from -143.0 to -122 and from -18.75 to -15.55, respectively. The values of δ 2 H and δ 18 O in water from the 38 ground-water sites ranged from -141.0 to -120.0 and from -18.55 to -14.95, respectively

  19. Stable isotope ratio measurements on highly enriched water samples by means of laser spectrometry

    NARCIS (Netherlands)

    van Trigt, R; Kerstel, E.R.T.; Visser, GH; Meijer, H.A.J.

    2001-01-01

    We demonstrate the feasibility of using laser spectrometry (LS) to analyze isotopically highly enriched water samples (i.e., delta H-2 less than or equal to 15000 parts per thousand, delta O-18 less than or equal to 1200 parts per thousand), as often used in the biomedical doubly labeled water (DLW)

  20. Use of stable isotopes for estimating water and nitrogen transport in plants

    International Nuclear Information System (INIS)

    Grygoryuk, I.P.; Petrenko, N.I.; Shvedova, O.Yu.; Tkachev, V.I.; Yaroshenko, O.A.

    1998-01-01

    Peculiarities in the response of various wheat cultivars and maize hybrids to water deficiency were studied in laboratory and vegetation experiments. Their resistance to extemal environmental factors was estimated by changes in nitrogen ( 15 N) and water (HDO) accumulation, transport and distribution in plant organs. The water supply was maintained at 60% FWC (control) and was reduced to 30% FWC (experiment) in the absence of plant watering during different stages or with use of polyethylene glycol. Decrease in water potential of medium from -0.05 (control) to -0.5, -0.9 and -1.6 MPa resulted in inhibition of water absorption, transport and distribution in spring wheat organs. After 24-hour stress, root absorption of water of drought-resistant varieties as compared to non-drought resistant ones was more sensitive, during 5, 10 and 15 min intervals after HDO introduction in nutrition medium. Strong depression of water exchange was observed at weaker stress in non-resistant variety. HDO absorption of the low part of the stem at short exposure resembled that of roots. The 24-hour stress revealed the tendency to sharper inhibition of absorption of labelled water in leaves of resistant variety. At a more durable stress the intensity of leaf water-exchange resistant variety was stabilized, while in the non-resistant variety it was reduced considerably. The intensity of HDO and 15 N exchange under stress conditions depended on the lability of regulator mechanism of water transport. Genotypic specificity of N use by wheat and maize plants depending on water supply and inclusion of 15 N in total and protein N was found. The 15 N content in total N in spring wheat cultivars under optimum water supply and under drought made 3.65 to 6.20 and 1.69 to 3.47, respectively. The 15 N content in protein N under the above conditions was 3.03 to 5.96 and 2.36 to 2.93, respectively. At water stress the main mass of labelled N in plant roots and stems was localized, while its intake into

  1. Stable isotope study of ground water recharge and movement in the Shogawa Fan, Toyama

    International Nuclear Information System (INIS)

    Mizutani, Yoshihiko; Oda, Matsuhisa

    1983-01-01

    Deuterium and oxygen-18 measurements of ground and river waters of the Shogawa Fan, Toyama, have been used to identify sources of water in aquifers in the Fan. A significant difference exists in deltaD and delta 18 O values between two major rivers flowing onto the Fan. On the basis of this difference, it is indicated that aquifers in the eastern half of the Fan are recharged from the Sho River and those in the western half of the Fan are from the Oyabe River. Chloride measurements of the waters support this identification of water sources. Contributions of other water sources to the aquifers are also indicated. The flow rate of infiltration from the Sho River is estimated to be 10-13 m/day in the confined aquifers in the northern part of the Fan. (author)

  2. Characterizing interactions between surface water and groundwater in the Jialu River basin using major ion chemistry and stable isotopes

    Directory of Open Access Journals (Sweden)

    L. Yang

    2012-11-01

    Full Text Available The Jialu River, a secondary tributary of the Huaihe River, has been severely contaminated from major contaminant sources, such as a number of untreated or lightly treated sewage waste in some cities. Groundwater along the river is not an isolated component of the hydrologic system, but is instead connected with the surface water. This study aims to investigate temporal and spatial variations in water chemistry affected by humans and to characterize the relationships between surface water (e.g. reservoirs, lakes and rivers and groundwater near the river in the shallow Quaternary aquifer. Concentration of Cl in north Zhengzhou City increased prominently due to the discharge of a large amount of domestic water. Nitrate and potassium show maximum concentrations in groundwater in Fugou County. These high levels can be attributed to the use of a large quantity of fertilizer over this region. Most surface water appeared to be continuously recharged from the surrounding groundwater (regional wells based on comparison surface water with groundwater levels, stable-isotopes and major ion signatures. However, the groundwater of a transitional well (location SY3 seemed to be recharged by river water via bank infiltration in September 2010. Fractional contributions of river water to the groundwater were calculated based on isotopic and chemical data using a mass-balance approach. Results show that the groundwater was approximately composed of 60–70% river water. These findings should be useful for a better understanding of hydrogeological processes at the river-aquifer interface and ultimately benefit water management in the future.

  3. Geochemistry, water balance, and stable isotopes of a “clean” pit lake at an abandoned tungsten mine, Montana, USA

    International Nuclear Information System (INIS)

    Gammons, Christopher H.; Pape, Barbara L.; Parker, Stephen R.; Poulson, Simon R.; Blank, Carrine E.

    2013-01-01

    Highlights: • An abandoned open pit mine is now a 30 m deep lake with excellent water quality. • Concentrations of sulfate, nutrients, and most trace metals are extremely low. • Based on water isotopes, the lake is 30% evaporated with a 2.5 yr residence time. • Stable isotopes of DIC and DO track in-lake bio-geochemical processes. • Phytoplankton are active at depths as great as 20 m. - Abstract: The Calvert Mine is a small tungsten-rich (scheelite) skarn deposit in a remote, mountainous region of southwest Montana, USA. The open-pit mine closed in the 1970s and subsequently flooded to form a pit lake that is roughly conical in shape, 30 m deep and 120 m in diameter, with no surface inlet or outlet. The lake is holomictic with a groundwater flow-through hydrology and an estimated residence time of 2.5–5 y. Water isotopes show that the lake is at an approximate steady state with respect to water balance and has experienced 30% evaporation. The lake has a near-neutral pH, exceptional clarity, and extremely low concentrations of nutrients, sulfate, and most metals, including tungsten. Manganese concentrations are slightly elevated and increase with depth towards the sediment–water interface. Despite seasonally anoxic conditions in the deep water, dissolved Fe concentrations are orders of magnitude lower than Mn, suggesting that insufficient organic carbon is present in the sediment of this oligotrophic lake to drive bacterial Fe reduction. Based on stable isotope fingerprinting, diffuse seepage that enters a nearby headwater stream at the base of a large waste-rock pile can be directly linked to the partially evaporated pit lake. However, this seepage has neutral pH and low metal concentrations, and poses no threats to the environment. Stable isotopes of dissolved inorganic carbon (DIC) and dissolved oxygen (DO) are used to track the relative importance of photosynthesis and respiration with depth. In summer, a zone of high productivity exists near the

  4. Sensation of Cold during the Ice Water Test Corresponds to the Perception of Pain during Botulinum Toxin Bladder Wall Injections.

    Science.gov (United States)

    Reitz, André; Hüsch, Tanja; Doggweiler, Regula; Buse, Stephan; Haferkamp, Axel

    2018-01-01

    To investigate the association of bladder cold sensation (BCS) during the ice water test (IWT) and pain perception when botulinum toxin injections (BTI) are administered into the bladder wall. In 86 patients with idiopathic overactive bladder, the BCS during the IWT was investigated. Patients were divided into 2 groups: with and without BCS. During subsequent administration of BTI, the number of perceived and painful injections as well as the pain levels on a 0-100 pain scale were compared in both groups using Student t test. Thirty-five patients reported a BCS, while 51 did not. After 10 BTI, the mean number of perceived injections was 7.9 in patients with and 2.4 in patients without BCS (p sensation (p perceptions of cold and pain in the urinary bladder may use similar receptors and neuronal pathways. © 2018 S. Karger AG, Basel.

  5. Leaf water enrichment of stable water isotopes (δ18O and δD) in a mature oil palm plantation in Jambi province, Indonesia.

    Science.gov (United States)

    Bonazza, Mattia; Tjoa, Aiyen; Knohl, Alexander

    2017-04-01

    During the last few decades, Indonesia experienced rapid and large scale land-use change towards intensively managed crops, one of them is oil palm. This transition results in warmer and dryer conditions in microclimate. The impacts on the hydrological cycle and on water-use by plants are, however, not yet completely clear. Water stable isotopes are useful tracers of the hydrological processes and can provide means to partition evapotranspiration into evaporation and transpiration. A key parameter, however, is the enrichment of water stable isotope in plant tissue such as leaves that can provide estimates on the isotopic composition of transpiration. Here we present the results of a field campaign conducted in a mature oil palm plantation in Jambi province, Indonesia. We combined continuous measurements of water vapor isotopic composition and mixing ratio with isotopic analysis of water stored in different pools like oil palm leaves, epiphytes, trunk organic matter and soil collected over a three days period. Leaf enrichment varied from -2 ‰ to 10 ‰ relative to source (ground) water. The temporal variability followed Craig and Gordon model predictions for leaf water enrichment. An improved agreement was reached after considering the Péclet effect with an appropriate value of the characteristic length (L). Measured stomatal conductance (gs) on two different sets of leaves (top and bottom canopy) was mainly controlled by radiation (photosynthetically active radiation) and vapor pressure deficit. We assume that this control could be explained in conditions where soil water content is not representing a limiting factor. Understanding leaf water enrichment provides one step towards partitioning ET.

  6. Pu(V) as the stable form of oxidized plutonium in natural waters

    International Nuclear Information System (INIS)

    Orlandini, K.A.; Penrose, W.R.; Nelson, D.M.

    1986-01-01

    This work presents analytical evidence supporting the proposition that Pu(V) is the sole or predominant form of oxidized plutonium in natural waters. Two independent methods, the selective adsorption of Pu(VI) by silica gel, and the somewhat less selective coprecipitation of Pu(V) with calcium carbonate, were developed to separate Pu(V) from Pu(VI). Measurements of ambient plutonium in several natural waters by these methods found only Pu(V). In laboratory tracer studies, Pu(VI) was shown to be highly unstable in dilute bicarbonate solution and in Lake Michigan water, reducing in first-order fashion to Pu(V). (orig.)

  7. The application of stable carbon isotope ratios as water quality indicators in coastal areas of Karachi, Pakistan

    International Nuclear Information System (INIS)

    Qureshi, R.M.; Mashiatullah, A.; Javed, T.; Tasneem, M.A.; Sajjad, M.I.; Saleem, M.; Khan, S.H.; Rizvi, S.H.N.; Siddiqui, S.A.; Qari, R.

    1998-01-01

    Stable carbon isotope ratios (δ 13 C) of total dissolved inorganic carbon (TDIC), total inorganic and organic carbon in bottom sediments, as well as sea plants in polluted water sources, non-polluted Karachi Sea water and pollution recipients are used to elaborate pollution scenario of shallow marine environment off Karachi coast. These results are supplemented with stable isotope composition of nitrogen (δ 15 N) in seaweeds and mangroves, toxic/trace metal concentration in sea-bottom sediments, total Coliform bacterial population, electrical conductivity, temperature and turbidity. Isotopic data shows that the mangrove ecosystem and the tidal fluctuations play a key role in controlling contamination inventories in shallow sea water off Karachi coast, specifically the Manora Channel. The Karachi harbour zone is found to be the most heavily polluted marine site in Manora channel during high as well as low tide regimes. Significant concentrations of toxic metals such as Pb, Ni, Cr, Zn, V, U are observed in off-shore sediments of Karachi coast. The results show that sewage and industrial wastes are the main sources of heavy metal pollution in Karachi harbour, Manora Channel exit zone and the southeast coast. However, as compared to other coastal areas, the Karachi coast is moderately polluted. Studies suggest incorporation of quick remedial measures to combat pollution in shallow marine environments off Karachi Coast. (author)

  8. Direct Measurements of Quantum Kinetic Energy Tensor in Stable and Metastable Water near the Triple Point: An Experimental Benchmark.

    Science.gov (United States)

    Andreani, Carla; Romanelli, Giovanni; Senesi, Roberto

    2016-06-16

    This study presents the first direct and quantitative measurement of the nuclear momentum distribution anisotropy and the quantum kinetic energy tensor in stable and metastable (supercooled) water near its triple point, using deep inelastic neutron scattering (DINS). From the experimental spectra, accurate line shapes of the hydrogen momentum distributions are derived using an anisotropic Gaussian and a model-independent framework. The experimental results, benchmarked with those obtained for the solid phase, provide the state of the art directional values of the hydrogen mean kinetic energy in metastable water. The determinations of the direction kinetic energies in the supercooled phase, provide accurate and quantitative measurements of these dynamical observables in metastable and stable phases, that is, key insight in the physical mechanisms of the hydrogen quantum state in both disordered and polycrystalline systems. The remarkable findings of this study establish novel insight into further expand the capacity and accuracy of DINS investigations of the nuclear quantum effects in water and represent reference experimental values for theoretical investigations.

  9. Bromide as a tracer for studying water movement and nitrate displacement in soils: comparison with stable isotope tracers

    International Nuclear Information System (INIS)

    Russow, R.; Knappe, S.

    1999-01-01

    Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and 15 N. Its great advantage over radioactive tracers (e.g. tritium), which outweighs their extreme sensitivity and ease of measurement and which it has in common with stable isotopes, is that it does not require radiation protection measures. However, there are also constraints on the use of bromide as a tracer in soil/water/plant systems. Our own studies on different soils using D 2 O, bromide and [ 15 N]-nitrate in lysimeters suggest that the above assumptions on bromide tracers need not always be valid under conditions as they prevail in biologically active soils. As the present paper shows, these studies permit a good assessment of the possibilities and limits to these tracers [de

  10. Stable hydrogen and oxygen isotopes of tap water reveal structure of the San Francisco Bay Area's water system and adjustments during a major drought.

    Science.gov (United States)

    Tipple, Brett J; Jameel, Yusuf; Chau, Thuan H; Mancuso, Christy J; Bowen, Gabriel J; Dufour, Alexis; Chesson, Lesley A; Ehleringer, James R

    2017-08-01

    Water availability and sustainability in the Western United States is a major flashpoint among expanding communities, growing industries, and productive agricultural lands. This issue came to a head in 2015 in the State of California, when the State mandated a 25% reduction in urban water use following a multi-year drought that significantly depleted water resources. Water demands and challenges in supplying water are only expected to intensify as climate perturbations, such as the 2012-2015 California Drought, become more common. As a consequence, there is an increased need to understand linkages between urban centers, water transport and usage, and the impacts of climate change on water resources. To assess if stable hydrogen and oxygen isotope ratios could increase the understanding of these relationships within a megalopolis in the Western United States, we collected and analyzed 723 tap waters across the San Francisco Bay Area during seven collection campaigns spanning 21 months during 2013-2015. The San Francisco Bay Area was selected as it has well-characterized water management strategies and the 2012-2105 California Drought dramatically affected its water resources. Consistent with known water management strategies and previously collected isotope data, we found large spatiotemporal variations in the δ 2 H and δ 18 O values of tap waters within the Bay Area. This is indicative of complex water transport systems and varying municipality-scale management decisions. We observed δ 2 H and δ 18 O values of tap water consistent with waters originating from snowmelt from the Sierra Nevada Mountains, local precipitation, ground water, and partially evaporated reservoir sources. A cluster analysis of the isotope data collected in this study grouped waters from 43 static sampling sites that were associated with specific water utility providers within the San Francisco Bay Area and known management practices. Various management responses to the drought, such as

  11. The Use of Stable Water Isotopes as Tracers in Soil Aquifer Treatment (SAT and in Regional Water Systems

    Directory of Open Access Journals (Sweden)

    Ido Negev

    2017-01-01

    Full Text Available This study examines the feasibility of tracing and quantifying the progress of different water sources along the water–effluent–SAT (Soil Aquifer Treatment chain using 2H and 18O isotopes. The research was conducted at the Dan Region Reclamation Plant (Shafdan, which reclaims ~135 MCM/year of effluent for irrigation. Water samples representing different stages along the chain were taken in two surveys during 2010–2011 and 2014. δ18O and δ2H values were used for mixing ratios (MR calculations, and compared with calculated MRs using chloride and carbamazepine concentrations. The results showed a relative enrichment of 18O and 2H in the Israeli water system compared to the regional groundwater, due to the addition of massive quantities of desalinated water. A linear correlation for δ2H vs. δ18O with a slope of 4.5 was found for the different freshwater sources and their mixing products, suggesting evaporation-mixing effects. MR values indicate on the spreading of new type of effluent originating from desalinated water in the aquifer. A dilution model explains the isotopic compositions in the water system and of the Shafdan effluents. Water isotopes have an advantage over other tracers, due to the ability to predict their ratio in the supply system and in the effluent, based on mass balance calculations and on knowledge of water supply volumes.

  12. Fluid-structure interaction analysis of a water pool under loading caused by steam injection

    International Nuclear Information System (INIS)

    Timperi, A.; Paettikangas, T.; Niemi, J.; Ilvonen, M.

    2006-04-01

    CFD and structural analysis codes. MpCCI 3.0 was used for coupling Fluent CFD code with ABAQUS FE code. ES-FSI was used for coupling Star-CD CFD code with ABAQUS. FSI analyses, in which the calculation was carried out entirely in ABAQUS, were also performed. In this case, acoustic elements were used for the fluid and the acoustic and structural domains were coupled. FSI calculations were performed for simple test cases and for a test pool at Lappeenranta University of Technology. The Method of Images was studied as an alternative method for the analyses of the pool. Particularly, the determination of pressure source for the method was studied. Earlier work carried out with the homogenous two-phase model was continued by testing the model with Fluent. Calculation of condensation of steam in a water pool was tested with a new implementation. The two-directionally coupled simulations of the pool with MpCCI and ES-FSI were found to be numerically instable. It was concluded that an implicit coupling method may have to be used in order to avoid the instability. Calculations of the pool were finally performed by using one directional coupling. In the simulations with MpCCI, the incompressible and compressible VOF models of Fluent were used. With ES-FSI, the incompressible VOF model of Star-CD was used for modelling the beginning of a steam injection experiment. The magnitudes of pressure and stress peaks in the simulation and experiment were of comparable size. Otherwise, however, differences between the simulation and experiment were large due to the simplifications used in the simulation. Results obtained with the acoustic-structural FE analyses were compared to analytical and experimental results. The results indicated that the coupled acoustic-structural analysis can be used for calculating the coupled Eigenmodes of BWR pressure suppression pools. (au)

  13. Fluid-structure interaction analysis of a water pool under loading caused by steam injection

    Energy Technology Data Exchange (ETDEWEB)

    Timperi, A.; Paettikangas, T.; Niemi, J.; Ilvonen, M. [VTT Technical Researc Centre of Finland (Finland)

    2006-04-15

    CFD and structural analysis codes. MpCCI 3.0 was used for coupling Fluent CFD code with ABAQUS FE code. ES-FSI was used for coupling Star-CD CFD code with ABAQUS. FSI analyses, in which the calculation was carried out entirely in ABAQUS, were also performed. In this case, acoustic elements were used for the fluid and the acoustic and structural domains were coupled. FSI calculations were performed for simple test cases and for a test pool at Lappeenranta University of Technology. The Method of Images was studied as an alternative method for the analyses of the pool. Particularly, the determination of pressure source for the method was studied. Earlier work carried out with the homogenous two-phase model was continued by testing the model with Fluent. Calculation of condensation of steam in a water pool was tested with a new implementation. The two-directionally coupled simulations of the pool with MpCCI and ES-FSI were found to be numerically instable. It was concluded that an implicit coupling method may have to be used in order to avoid the instability. Calculations of the pool were finally performed by using one directional coupling. In the simulations with MpCCI, the incompressible and compressible VOF models of Fluent were used. With ES-FSI, the incompressible VOF model of Star-CD was used for modelling the beginning of a steam injection experiment. The magnitudes of pressure and stress peaks in the simulation and experiment were of comparable size. Otherwise, however, differences between the simulation and experiment were large due to the simplifications used in the simulation. Results obtained with the acoustic-structural FE analyses were compared to analytical and experimental results. The results indicated that the coupled acoustic-structural analysis can be used for calculating the coupled Eigenmodes of BWR pressure suppression pools. (au)

  14. Relationships of stable isotopes, water-rock interaction and salinization in fractured aquifers, Petrolina region, Pernambuco State, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Priscila Sousa, E-mail: priscila.silva@cprm.gov.br [Serviço Geológico do Brasil (CPRM), Manaus, AM (Brazil); Campos, José Eloi Guimarães; Cunha, Luciano Soares; Mancini, Luís Henrique, E-mail: eloi@unb.br, E-mail: lucianosc@unb.br, E-mail: lmancini@unb.br [Universidade de Brasília (UnB), Brasília, DF (Brazil)

    2018-01-15

    The Petrolina County, Pernambuco State, Brazil, presents specificities that make it unique from a hydrogeological point of view. Water resource scarcity is both a quantitative and qualitative issue. The climate is classified as semiarid, having low precipitation, along with high temperatures and evapotranspiration rates. Aquifer zones are related to low connected fractures resulting in a restricted water flow in the aquifer. The recharge is limited and the groundwater salinity is high. Stable isotope analyses of H and O were developed in groundwater samples (with different electrical conductivity) and surface water collected in a bypass channel flowing from the São Francisco River. The results were plotted in a δD ‰ versus δ{sup 18}O ‰ graph along with the curves of the global and local meteoric water line. Groundwater samples showed unexpected results showing a lighter sign pattern when compared to the meteoric waters. More negative δD and δ{sup 18}O values indicate an enrichment in light isotopes, which show that this process is not influenced by surface processes, where the enrichment occurs in heavy isotopes due to evaporation. The isotopic signature observed is interpreted either as resulting from the water-rock interaction, or as resulting from recharge from paleo rains. The waters are old and show restricted flow. So the water-rock contact time is extended. In the rock weathering processes, through the hydration of feldspars, there is preferential assimilation of heavy isotopes at the expense of the lighter ones that remain in the water. Analyses of the {sup 87}Sr/{sup 86}Sr ratio and isotopic groundwater dating assist in the interpretations. (author)

  15. A New Treatment Strategy for Inactivating Algae in Ballast Water Based on Multi-Trial Injections of Chlorine.

    Science.gov (United States)

    Sun, Jinyang; Wang, Junsheng; Pan, Xinxiang; Yuan, Haichao

    2015-06-09

    Ships' ballast water can carry aquatic organisms into foreign ecosystems. In our previous studies, a concept using ion exchange membrane electrolysis to treat ballast water has been proven. In addition to other substantial approaches, a new strategy for inactivating algae is proposed based on the developed ballast water treatment system. In the new strategy, the means of multi-trial injection with small doses of electrolytic products is applied for inactivating algae. To demonstrate the performance of the new strategy, contrast experiments between new strategies and routine processes were conducted. Four algae species including Chlorella vulgaris, Platymonas subcordiformis, Prorocentrum micans and Karenia mikimotoi were chosen as samples. The different experimental parameters are studied including the injection times and doses of electrolytic products. Compared with the conventional one trial injection method, mortality rate time (MRT) and available chlorine concentration can be saved up to about 84% and 40%, respectively, under the application of the new strategy. The proposed new approach has great potential in practical ballast water treatment. Furthermore, the strategy is also helpful for deep insight of mechanism of algal tolerance.

  16. Letter Report: Stable Hydrogen and Oxygen Isotope Analysis of B-Complex Perched Water Samples

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Brady D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moran, James J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nims, Megan K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Saunders, Danielle L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-04-13

    Fine-grained sediments associated with the Cold Creek Unit at Hanford have caused the formation of a perched water aquifer in the deep vadose zone at the B Complex area, which includes waste sites in the 200-DV-1 Operable Unit and the single-shell tank farms in Waste Management Area B-BX-BY. High levels of contaminants, such as uranium, technetium-99, and nitrate, make this aquifer a continuing source of contamination for the groundwater located a few meters below the perched zone. Analysis of deuterium (2H) and 18-oxygen (18O) of nine perched water samples from three different wells was performed. Samples represent time points from hydraulic tests performed on the perched aquifer using the three wells. The isotope analyses showed that the perched water had δ2H and δ18O ratios consistent with the regional meteoric water line, indicating that local precipitation events at the Hanford site likely account for recharge of the perched water aquifer. Data from the isotope analysis can be used along with pumping and recovery data to help understand the perched water dynamics related to aquifer size and hydraulic control of the aquifer in the future.

  17. Fabrication of stable and durable superhydrophobic surface on copper substrates for oil-water separation and ice-over delay.

    Science.gov (United States)

    Guo, Jie; Yang, Fuchao; Guo, Zhiguang

    2016-03-15

    We report a simple and rapid method to fabricate superhydrophobic films on copper substrates via Fe(3+) etching and octadecanethiol (ODT) modification. The etching process can be as short as 5 min and the ODT treatment only takes several seconds. In addition, the whole process is quite flexible in reaction time. The superhydrophobicity of as-prepared surfaces is mechanically durable and chemically stable, which have great performance in oil-water separation and ice-over resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. On-line technique for preparingand measuring stable carbon isotopeof total dissolved inorganic carbonin water samples ( d13CTDIC

    Directory of Open Access Journals (Sweden)

    S. Inguaggiato

    2005-06-01

    Full Text Available A fast and completely automated procedure is proposed for the preparation and determination of d13C of total inorganic carbon dissolved in water ( d13CTDIC. This method is based on the acidification of water samples transforming the whole dissolved inorganic carbon species into CO2. Water samples are directly injected by syringe into 5.9 ml vials with screw caps which have a pierciable rubber septum. An Analytical Precision «Carbonate Prep System» was used both to flush pure helium into the vials and to automatically dispense a fixed amount of H3PO4. Full-equilibrium conditions between produced CO2 and water are reached at a temperature of 70°C (± 0.1°C in less than 24 h. Carbon isotope ratios (13C/ 12C were measured on an AP 2003 continuous flow mass spectrometer, connected on-line with the injection system. The precision and reproducibility of the proposed method was tested both on aqueous standard solutions prepared using Na2CO3 with d13C=-10.78 per mil versus PDB (1 s= 0.08, n = 11, and at five different concentrations (2, 3, 4, 5 and 20 mmol/l and on more than thirty natural samples. Mean d13CTDIC on standard solution samples is ?10.89 < per mil versus PDB (1 s= 0.18, n = 50, thus revealing both a good analytical precision and reproducibility. A comparison between average d13CTDIC values on a quadruplicate set of natural samples and those obtained following the chemical and physical stripping method highlights a good agreement between the two analytical methods.

  19. Diversity of Microbial Communities in Production and Injection Waters of Algerian Oilfields Revealed by 16S rRNA Gene Amplicon 454 Pyrosequencing

    Science.gov (United States)

    Lenchi, Nesrine; İnceoğlu, Özgül; Kebbouche-Gana, Salima; Gana, Mohamed Lamine; Llirós, Marc; Servais, Pierre; García-Armisen, Tamara

    2013-01-01

    The microorganisms inhabiting many petroleum reservoirs are multi-extremophiles capable of surviving in environments with high temperature, pressure and salinity. Their activity influences oil quality and they are an important reservoir of enzymes of industrial interest. To study these microbial assemblages and to assess any modifications that may be caused by industrial practices, the bacterial and archaeal communities in waters from four Algerian oilfields were described and compared. Three different types of samples were analyzed: production waters from flooded wells, production waters from non-flooded wells and injection waters used for flooding (water-bearing formations). Microbial communities of production and injection waters appeared to be significantly different. From a quantitative point of view, injection waters harbored roughly ten times more microbial cells than production waters. Bacteria dominated in injection waters, while Archaea dominated in production waters. Statistical analysis based on the relative abundance and bacterial community composition (BCC) revealed significant differences between production and injection waters at both OTUs0.03 and phylum level. However, no significant difference was found between production waters from flooded and non-flooded wells, suggesting that most of the microorganisms introduced by the injection waters were unable to survive in the production waters. Furthermore, a Venn diagram generated to compare the BCC of production and injection waters of one flooded well revealed only 4% of shared bacterial OTUs. Phylogenetic analysis of bacterial sequences indicated that Alpha-, Beta- and Gammaproteobacteria were the main classes in most of the water samples. Archaeal sequences were only obtained from production wells and each well had a unique archaeal community composition, mainly belonging to Methanobacteria, Methanomicrobia, Thermoprotei and Halobacteria classes. Many of the bacterial genera retrieved had already

  20. Theoretical study of hydraulic jump during circular horizontal hot leg injection in pressurized water reactor

    International Nuclear Information System (INIS)

    El Hawary, Shehab; Abu-Elyazeed, Osayed S.M.; Fahmy, Adel Alyan; Meglaa, Khairy

    2016-01-01

    Highlights: • The model is developed to predict the occurrence of onset hydraulic jump in a circular pipe. • Theoretical results are in agreement with experimental results and theory. • Effects of diameter of the injection pipe, Froude number and injected coolant mass are studied. - Abstract: One important phenomenon occurring during Loss of Coolant Accident (LOCA) is Counter-Current Flow Limitation (CCFL). The incidence of such CCFL is introduced by the onset of hydraulic jump. In the present work, a one dimensional model was modified to fit circular hot channel. The model was used to study the factors affecting the initial Froude number, the location of the occurrence of the hydraulic jump, and the critical coolant flow depth during circular horizontal hot leg injection in US-APWR Mitsubishi Reactor. The results showed good agreement with published experimental data of the Upper Plenum Test Facility (UPTF) at Mannheim, Germany. It was found that higher injected coolant mass flow rate increases the initial Froude number, the location of the occurrence of the hydraulic jump, and the critical injection depth divided by the diameter of the injection pipe. Such behavior is thought to be due to the increase of the inertia force by increasing of the injected coolant mass flow rate and the inverse of the diameter of the injection pipe. It was found also that, the location of the occurrence of hydraulic jump increases with decreasing load effect. Therefore, these results reveal that the avoidance of CCFL as well as hydraulic jump through hot leg at maximum load can be achieved by decreasing the distance between the injection point and the pressure vessel to below 0.3 m, and with diameter of 4 in (10.16 cm) as the design diameter of the injection pipe in US-APWR Mitsubishi Reactor. Moreover, the maximum critical depth (56 cm) is less than the diameter of the hot leg (78.74 cm) at an injected coolant mass flow of 400 kg/s, and with diameter of 4 in (10.16 cm) as the

  1. The process of isothermal compression of gasses at sub-atmospheric pressures through regulated water injection in Braysson cycles

    International Nuclear Information System (INIS)

    Georgiou, Demos P.; Xenos, Triantafyllos

    2011-01-01

    Although the Braysson cycle constitutes the ideal limit for the Combined Cycle Power Plants, its actual implementation has not been achieved due to the difficulty in building the required isothermal compressor. The present study proposes the incorporation of regulated water injection during the final compression, which could maintain the temperature constant due to the evaporation. The analysis for the thermodynamic implications of the injection on the ideal version of the Braysson cycle indicates that the (ideal cycle) efficiency reduction will be minimal. The study provides an analysis for the water injection rate that will permit such a process and shows that the additional work needed to drive the process will not be affected significantly by the injection. In addition, it shows that the minimum temperature of the Braysson cycle will be lower than the corresponding level of the conventional (Gas-Steam turbine Combined cycle plants), something that could improve the efficiency as well. Finally it shows that the process may be expressed by a polytropic relationship of the type pv β = constant, where β ∼ 1.06.

  2. Synchronized droplet size measurements for Coal-Water-Slurry (CWS) diesel sprays of an electronically-controlled fuel injection system

    Science.gov (United States)

    Kihm, K. D.; Terracina, D. P.; Payne, S. E.; Caton, J. A.

    Experiments were completed to study intermittent coal-water slurry (CWS) fuel sprays injected from an electronically-controlled accumulator injector system. A laser diffraction particle analyzing (LDPA) technique was used to measure the spray diameters (Sauter mean diameter, SMD) assuming the Rosin-Rammler two parameter model. In order to ensure an accurate synchronization of the measurement with the intermittent sprays, a new synchronization technique was developed using the light extinction signal as a triggering source for the data taking initiation. This technique allowed measurement of SMD's near the spray tip where the light extinction was low and the data were free from the multiscattering bias. Coal-water slurry fuel with 50% coal loading in mass containing 5 (mu)m mass median diameter coal particulates was considered. Injection pressures ranging from 28 to 110 MPa, two different nozzle orifice diameters, 0.2 ad 0.4 mm, and four axial measurement locations from 60 to 120 mm from the nozzle orifice were studied. Measurements were made for pressurized (2.0 MPa in gauge) and for ambient chamber conditions. The spray SMD showed an increase with the distance of the axial measurement location and with the ambient gas density, and showed a decrease with increasing injection pressure. A correlation of the Sauter mean diameter with the injection conditions was determined. The results were also compared with previous SMD correlations that were available only for diesel fuel sprays.

  3. Carbon-14, tritium, stable isotope and chemical measurements on thermal waters from the Tauranga region

    International Nuclear Information System (INIS)

    Stewart, M.K.; McGill, R.C.; Taylor, C.B.; Whitehead, N.E.; Downes, C.J.

    1984-03-01

    The chemical compositions of groundwater from the Tauranga region are affected to varying degrees by reducing conditions due to buried organic matter. The levels of some dissolved constituents are also affected by mixing with sea water contained within the rocks and by rock-water interaction. Dissolved gas compositions range from oxygen-bearing to methane-bearing reflecting the varying redox conditions. Excess air may be present but further experiments are necessary to confirm this. Apparent ages deduced from carbon-14 measurements (corrected using 12C dilution and 13C fractionation methods) range from 2-25,000 years, suggesting that some of the waters were recharged during late Pleistocene or early Holocene time. ΔD and Δ18 O values of the oldest waters are slightly more negative than those of younger samples; this may indicate recharge during a cooler climate, in agreement with the 14C ages. Very low but significantly non-zero tritium contents (TR=(0.007-0.059)+-0.007) were measured using the high tritium-enrichment facilities at INS and the very low-background counters at the University of Bern. The tritium is thought to derive from contamination or nuclear reactions in the aquifer rocks rather than from recharge water

  4. Experiment HFR-B1: A preliminary analysis of the water-vapor injection experiments in capsule 3

    International Nuclear Information System (INIS)

    Myers, B.F.

    1993-01-01

    A preliminary analysis of the response of uranium oxycarbide (UCO) fuel to water vapor addition in capsule 3 of experiment HFR-B1 (HFR-B1/3) has been conducted. The analysis provides an early indication of the behavior of fission gas release under a wider range of water-vapor pressures and of temperatures than heretofore studied. A preliminary analysis of selected aspects of the water-vapor injection tests in capsule 3 of experiment HFR-B1 is presented. The release of fission gas stored in bubbles and the diffusive release of fission-gas atoms are distinguished. The dependence of the release of stored fission gas ( 85m Kr) on water-vapor pressure, P(H 2 O), and temperature were established taking into account the contributing mechanisms of gaseous release, the effect of graphite hydrolysis, and the requirement of consistency with experiment HRB-17 in which similar water-vapor injection tests were conducted. The dependence on P(H 2 O) becomes weaker as temperatures increase above 770 degree C; the activation energy for release of stored-fission gas is 393 kJ/mol. Isorelease curves for the pressure-temperature plane were deduced from a derived functional relation. The stored-fission gas releases as a function of P(H 2 O) at a common temperature for experiments HFR-B1 and HRB-17 differ by a factor of 4; this discrepancy could be attributed to the differences in fission-rate density and neutron flux between the two experiments. Diffusive release of fission gas occurred during and after the release of stored gas. The ratio of diffusive release during water-vapor injection to that prior to injection varied in contrast to the results from HRB-17. The variation was attributed to the practice of injecting water vapor into HFR-B1 before sintering of the fuel, hydrolyzed in the previous test, was completed. The derived activation energy for diffusive release is 23.6 kJ/mol

  5. Experiment HFR-B1: A preliminary analysis of the water-vapor injection experiments in capsule 3

    Energy Technology Data Exchange (ETDEWEB)

    Myers, B.F.

    1993-08-01

    A preliminary analysis of the response of uranium oxycarbide (UCO) fuel to water vapor addition in capsule 3 of experiment HFR-B1 (HFR-B1/3) has been conducted. The analysis provides an early indication of the behavior of fission gas release under a wider range of water-vapor pressures and of temperatures than heretofore studied. A preliminary analysis of selected aspects of the water-vapor injection tests in capsule 3 of experiment HFR-B1 is presented. The release of fission gas stored in bubbles and the diffusive release of fission-gas atoms are distinguished. The dependence of the release of stored fission gas ({sup 85m}Kr) on water-vapor pressure, P(H{sub 2}O), and temperature were established taking into account the contributing mechanisms of gaseous release, the effect of graphite hydrolysis, and the requirement of consistency with experiment HRB-17 in which similar water-vapor injection tests were conducted. The dependence on P(H{sub 2}O) becomes weaker as temperatures increase above 770{degree}C; the activation energy for release of stored-fission gas is 393 kJ/mol. Isorelease curves for the pressure-temperature plane were deduced from a derived functional relation. The stored-fission gas releases as a function of P(H{sub 2}O) at a common temperature for experiments HFR-B1 and HRB-17 differ by a factor of 4; this discrepancy could be attributed to the differences in fission-rate density and neutron flux between the two experiments. Diffusive release of fission gas occurred during and after the release of stored gas. The ratio of diffusive release during water-vapor injection to that prior to injection varied in contrast to the results from HRB-17. The variation was attributed to the practice of injecting water vapor into HFR-B1 before sintering of the fuel, hydrolyzed in the previous test, was completed. The derived activation energy for diffusive release is 23.6 kJ/mol.

  6. A scalable synthesis of highly stable and water dispersible Ag 44(SR)30 nanoclusters

    KAUST Repository

    AbdulHalim, Lina G.; Ashraf, Sumaira; Katsiev, Khabiboulakh; Kirmani, Ahmad R.; Kothalawala, Nuwan; Anjum, Dalaver H.; Abbas, Sikandar Zameer; Amassian, Aram; Stellacci, Francesco; Dass, Amala; Hussain, Irshad; Bakr, Osman

    2013-01-01

    We report the synthesis of atomically monodisperse thiol-protected silver nanoclusters [Ag44(SR)30] m, (SR = 5-mercapto-2-nitrobenzoic acid) in which the product nanocluster is highly stable in contrast to previous preparation methods. The method is one-pot, scalable, and produces nanoclusters that are stable in aqueous solution for at least 9 months at room temperature under ambient conditions, with very little degradation to their unique UV-Vis optical absorption spectrum. The composition, size, and monodispersity were determined by electrospray ionization mass spectrometry and analytical ultracentrifugation. The produced nanoclusters are likely to be in a superatom charge-state of m = 4-, due to the fact that their optical absorption spectrum shares most of the unique features of the intense and broadly absorbing nanoparticles identified as [Ag44(SR) 30]4- by Harkness et al. (Nanoscale, 2012, 4, 4269). A protocol to transfer the nanoclusters to organic solvents is also described. Using the disperse nanoclusters in organic media, we fabricated solid-state films of [Ag44(SR)30]m that retained all the distinct features of the optical absorption spectrum of the nanoclusters in solution. The films were studied by X-ray diffraction and photoelectron spectroscopy in order to investigate their crystallinity, atomic composition and valence band structure. The stability, scalability, and the film fabrication method demonstrated in this work pave the way towards the crystallization of [Ag44(SR)30]m and its full structural determination by single crystal X-ray diffraction. Moreover, due to their unique and attractive optical properties with multiple optical transitions, we anticipate these clusters to find practical applications in light-harvesting, such as photovoltaics and photocatalysis, which have been hindered so far by the instability of previous generations of the cluster. © 2013 The Royal Society of Chemistry.

  7. Characterization of Adsorption Enthalpy of Novel Water-Stable Zeolites and Metal-Organic Frameworks

    Science.gov (United States)

    Kim, Hyunho; Cho, H. Jeremy; Narayanan, Shankar; Yang, Sungwoo; Furukawa, Hiroyasu; Schiffres, Scott; Li, Xiansen; Zhang, Yue-Biao; Jiang, Juncong; Yaghi, Omar M.; Wang, Evelyn N.

    2016-01-01

    Water adsorption is becoming increasingly important for many applications including thermal energy storage, desalination, and water harvesting. To develop such applications, it is essential to understand both adsorbent-adsorbate and adsorbate-adsorbate interactions, and also the energy required for adsorption/desorption processes of porous material-adsorbate systems, such as zeolites and metal-organic frameworks (MOFs). In this study, we present a technique to characterize the enthalpy of adsorption/desorption of zeolites and MOF-801 with water as an adsorbate by conducting desorption experiments with conventional differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). With this method, the enthalpies of adsorption of previously uncharacterized adsorbents were estimated as a function of both uptake and temperature. Our characterizations indicate that the adsorption enthalpies of type I zeolites can increase to greater than twice the latent heat whereas adsorption enthalpies of MOF-801 are nearly constant for a wide range of vapor uptakes.

  8. Characterization of Adsorption Enthalpy of Novel Water-Stable Zeolites and Metal-Organic Frameworks

    Science.gov (United States)

    Kim, Hyunho; Cho, H. Jeremy; Narayanan, Shankar; Yang, Sungwoo; Furukawa, Hiroyasu; Schiffres, Scott; Li, Xiansen; Zhang, Yue-Biao; Jiang, Juncong; Yaghi, Omar M.; Wang, Evelyn N.

    2016-01-01

    Water adsorption is becoming increasingly important for many applications including thermal energy storage, desalination, and water harvesting. To develop such applications, it is essential to understand both adsorbent-adsorbate and adsorbate-adsorbate interactions, and also the energy required for adsorption/desorption processes of porous material-adsorbate systems, such as zeolites and metal-organic frameworks (MOFs). In this study, we present a technique to characterize the enthalpy of adsorption/desorption of zeolites and MOF-801 with water as an adsorbate by conducting desorption experiments with conventional differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). With this method, the enthalpies of adsorption of previously uncharacterized adsorbents were estimated as a function of both uptake and temperature. Our characterizations indicate that the adsorption enthalpies of type I zeolites can increase to greater than twice the latent heat whereas adsorption enthalpies of MOF-801 are nearly constant for a wide range of vapor uptakes. PMID:26796523

  9. Geological Factors Affecting Flow Spatial Continuity in Water Injection of Units Operating in the LGITJ–0102 Ore Body

    Directory of Open Access Journals (Sweden)

    Ilver M. Soto-Loaiza

    2016-05-01

    Full Text Available The objective of the investigation was to identify the geological factors affecting the spatial continuity of the flow during the process of flank water injection in the units operating in the Lower Lagunilla Hydrocarbon Ore Body. This included the evaluation of the recovery factor, the petro-physic properties such as porosity, permeability, water saturation and rock type and quality in each flow unit. it was observed that the rock type of the geologic structure in the ore body is variable. The lowest values for the petro-physic properties were found in the southern area while a high variability of these parameters was observed in the northern and central areas. It was concluded that the northern area has a great potential for the development of new injection projects for petroleum recovery.

  10. The feasibility of water injection into the turbine coolant to permit gas turbine contingency power for helicopter application

    Science.gov (United States)

    Van Fossen, G. J.

    1983-01-01

    It is pointed out that in certain emergency situations it may be desirable to obtain power from a helicopter engine at levels greater than the maximum rating. Yost (1976) has reported studies concerning methods of power augmentation in the one engine inoperative (OEI) case. It was found that a combination of water/alcohol injection into the inlet and overtemperature/overspeed could provide adequate emergency power. The present investigation is concerned with the results of a feasibility study which analytically investigated the maximum possible level of augmentation with constant gas generator turbine stress rupture life as a constraint. In the proposed scheme, the increased engine output is obtained by turbine overtemperature, however, the temperature of the compressor bleed air used for hot section cooling is lowered by injecting and evaporating water.

  11. SiC-C Composite as A Highly Stable and Easily Regenerable Photothermal Material for Practical Water Evaporation

    KAUST Repository

    Shi, Le

    2018-05-26

    Solar-driven water distillation by photothermal materials is emerging as a promising way of renewable energy-driven clean water production. In designing photothermal materials, light absorption, photo-to-thermal conversion efficiency, and ability to localize thermal energy at the water-air interface are three important considerations. However, one additional consideration, regenerability, has so far slipped out of the photothermal material designs at status quo. This work reveals that there is a fouling layer formed during photothermal evaporation of real seawater (Red Sea water) and domestic wastewater, which once formed, would be difficult to remove. Herein, we synthesize a SiC-C composite monolith as an effective photothermal material where carbon acts as photothermal component and SiC serves as a heat conductor and strong structural support. The high mechanical strength of the monolithic composite makes it able to withstand repeatedly high strength physical cleaning by brush scrubbing and sonication and the anti-carbon-loss mechanism generates zero carbon loss during the physical cleaning. In the case of the domestic wastewater evaporation, the bio- and organic foulants on the SiC-C composite monolith can be totally removed by annealing at 1000 oC in N2 atmosphere. We believe that the SiC-C composite monoliths are promising photothermal materials in practical solar-driven water evaporation applications thanks to their highly stable and easily regenerable properties and therefore more research efforts are warranted to further improve their performances.

  12. Towards a stable ion-solvating polymer electrolyte for advanced alkaline water electrolysis

    DEFF Research Database (Denmark)

    Aili, David; Wright, Andrew G.; Kraglund, Mikkel Rykær

    2017-01-01

    Advanced alkaline water electrolysis using ion-solvating polymer membranes as electrolytes represents a new direction in the field of electrochemical hydrogen production. Polybenzimidazole membranes equilibrated in aqueous KOH combine the mechanical robustness and gas-tightness of a polymer...... stability in alkaline environments. The novel electrolytes are extensively characterized with respect to physicochemical and electrochemical properties and the chemical stability is assessed in 0-50 wt% aqueous KOH for more than 6 months at 88 degrees C. In water electrolysis tests using porous 3...

  13. Stable isotope characterization of pan-derived and directly sampled atmospheric water vapour

    International Nuclear Information System (INIS)

    Maric, R.; St. Amour, N.A.; Gibson, J.J.; Edwards, T.W.D.

    2002-01-01

    Isotopic characterization of atmospheric water vapour, δ A , and its temporal variability are important prerequisites for quantifying water balance of surface reservoirs and partitioning of evaporation and transpiration fluxes using isotope techniques. Here we present results from a detailed comparison of several methods for determining δ A in field situations, (i) by back-calculation from isotopic and micrometeorological monitoring of a steady-state terminal reservoir (standard Class-A evaporation pan) using boundary-layer mass transfer models [1], (ii) through direct (cryogenic) sampling of ambient atmospheric moisture, and (iii) using the precipitation-equilibrium approximation (i.e., δ A =δ P - ε*)

  14. Effect of administration of water enriched in O2 by injection or electrolysis on transcutaneous oxygen pressure in anesthetized pigs.

    Science.gov (United States)

    Charton, Antoine; Péronnet, François; Doutreleau, Stephane; Lonsdorfer, Evelyne; Klein, Alexis; Jimenez, Liliana; Geny, Bernard; Diemunsch, Pierre; Richard, Ruddy

    2014-01-01

    Oral administration of oxygenated water has been shown to improve blood oxygenation and could be an alternate way for oxygen (O2) supply. In this experiment, tissue oxygenation was compared in anesthetized pigs receiving a placebo or water enriched in O2 by injection or a new electrolytic process. Forty-two pigs randomized in three groups received either mineral water as placebo or water enriched in O2 by injection or the electrolytic process (10 mL/kg in the stomach). Hemodynamic parameters, partial pressure of oxygen in the arterial blood (PaO2), skin blood flow, and tissue oxygenation (transcutaneous oxygen pressure, or TcPO2) were monitored during 90 minutes of general anesthesia. Absorption and tissue distribution of the three waters administered were assessed using dilution of deuterium oxide. Mean arterial pressure, heart rate, PaO2, arteriovenous oxygen difference, and water absorption from the gut were not significantly different among the three groups. The deuterium to protium ratio was also similar in the plasma, skin, and muscle at the end of the protocol. Skin blood flow decreased in the three groups. TcPO2 slowly decreased over the last 60 minutes of the experiment in the three groups, but when compared to the control group, the values remained significantly higher in animals that received the water enriched in O2 by electrolysis. In this protocol, water enriched in O2 by electrolysis lessened the decline of peripheral tissue oxygenation. This observation is compatible with the claim that the electrolytic process generates water clathrates which trap O2 and facilitate O2 diffusion along pressure gradients. Potential applications of O2-enriched water include an alternate method of oxygen supply.

  15. A mobile and self-sufficient lab for high frequency measurements of stable water isotopes and chemistry of multiple water sources

    Science.gov (United States)

    Windhorst, David; Kraft, Philipp; Holly, Hartmut; Sahraei, Amir; Breuer, Lutz

    2017-04-01

    Technical advances over the last years have made instruments for stable water isotope and water chemistry measurements smaller, more durable and energy efficient. It is nowadays feasible to deploy such instruments in situ during field campaigns. Coupled to an automated sample delivery system, high temporal resolution online measurements of various sources are within the bounds of economic and technical possibility. However, the day to day operation of such equipment still requires either a lot of man power and infrastructure or the implementation of a quasi-self-sufficient system. The challenge remains on how to facilitate and remotely operate such a system. We present the design and implementation of the Water Analysis Trailer for Environmental Research (WATER), an autonomous platform consisting of instruments for stable water isotope and water chemistry analysis. The system takes and measures samples in high temporal resolution (operation of up to one week several issues need to be addressed. The essential topics are: - self-sufficient power supply, - automated sample delivery and preparation, and - autonomous measurements and management interfacing all instruments. In addition to the basic requirements we implemented: - communication of all system states, alarm messages and measurement results to an internal as well as an external database via cellular telemetry, - automated storage of up to 300 frozen reference samples (100 mL, stored at -18°C), - climate control for temperature sensitive equipment (±1°C), - a local and remote (up to 20 km using radio telemetry) sensor network (i.e. to record states of the hydrological system and climate and soil conditions), also suitable to trigger specific measurements - automatic fire suppression and security system. The initial instrumentation includes a UV spectrometer (ProPs, Trios GmBH, Germany) to measure NO3-, COD, TOC and total suspended sediments, multiparameter water quality probe (YSI600R, YSI, USA) to measure

  16. An Efficient and Stable Hydrophobic Molecular Cobalt Catalyst for Water Electro-oxidation at Neutral pH

    KAUST Repository

    Chen, Ba-Tian

    2016-06-14

    The synthesis of a library of molecular water oxidation catalysts based on the Co complex of tris(2-benzimidazolylmethyl)amine is described. Hydrophobicity was identified as the key variable in mediating the catalytic competence of the complexes. The change in this parameter correlates with both the conformational mobility of the ligand core and the structural changes in the local solvent environment around the metal site. The optimal Co complex identified is hydrophobic, because of three semifluorinated side chains. It catalyzes water electro-oxidation efficiently at neutral pH, with an overpotential of 390 mV and a turnover frequency (TOF) of 1.83 s-1 in the absence of soluble Co salts. The catalyst can be immobilized through physisorption, and it remains stable in prolonged electrolysis experiments. © 2016 American Chemical Society.

  17. Stable solar-driven oxidation of water by semiconducting photoanodes protected by transparent catalytic nickel oxide films.

    Science.gov (United States)

    Sun, Ke; Saadi, Fadl H; Lichterman, Michael F; Hale, William G; Wang, Hsin-Ping; Zhou, Xinghao; Plymale, Noah T; Omelchenko, Stefan T; He, Jr-Hau; Papadantonakis, Kimberly M; Brunschwig, Bruce S; Lewis, Nathan S

    2015-03-24

    Reactively sputtered nickel oxide (NiOx) films provide transparent, antireflective, electrically conductive, chemically stable coatings that also are highly active electrocatalysts for the oxidation of water to O2(g). These NiOx coatings provide protective layers on a variety of technologically important semiconducting photoanodes, including textured crystalline Si passivated by amorphous silicon, crystalline n-type cadmium telluride, and hydrogenated amorphous silicon. Under anodic operation in 1.0 M aqueous potassium hydroxide (pH 14) in the presence of simulated sunlight, the NiOx films stabilized all of these self-passivating, high-efficiency semiconducting photoelectrodes for >100 h of sustained, quantitative solar-driven oxidation of water to O2(g).

  18. The use of chitosan as bioadhesive and its property improvement by radiation treatment for water-stable shrimp feed production

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Nguyen Duy; Hung, Nguyen Manh; Quynh, Tran Minh; Diep, Tran Bang; Binh, Nguen Van [Vietnam Atomic Energy Commission, Institute for Nuclear Science and Techniques, Caugiay, Hanoi (Viet Nam); Dung, Vu [Ministry of Fisheries, Research Institute of Marine Product, Haiphong (Viet Nam); Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2002-03-01

    Among marine polysaccharides, only chitosan with small content in feed (0.48-0.75%) could be selected to prepare shrimp feed-pellet having so high water-stability that meet the Standard of Vietnam Ministry of Fisheries 28-TCN 102/1997. Solid-state radiation treatment of chitosan with dose ranging from 10 to 200 kGy not only increased its solubility in solvents of dilute acid, but also improved the water-stability of feed-pellet product. Radiation treatment at sterilization doses (20-40 kGy) was evaluated as the most practical technology because irradiated chitosan with reduced content of 0.34% has capacity to be prepared feed-pellets stable as comparable to imported products. Results from feeding trials shown that chitosan containing feed did not affect the growth response and feed utilization efficiency such as weight gain (WG), feed conversion ratio (FCR) and productivity at harvest. (author)

  19. An Efficient and Stable Hydrophobic Molecular Cobalt Catalyst for Water Electro-oxidation at Neutral pH

    KAUST Repository

    Chen, Batian; Morlanes, Natalia Sanchez; Adogla, Enoch; Takanabe, Kazuhiro; Rodionov, Valentin

    2016-01-01

    The synthesis of a library of molecular water oxidation catalysts based on the Co complex of tris(2-benzimidazolylmethyl)amine is described. Hydrophobicity was identified as the key variable in mediating the catalytic competence of the complexes. The change in this parameter correlates with both the conformational mobility of the ligand core and the structural changes in the local solvent environment around the metal site. The optimal Co complex identified is hydrophobic, because of three semifluorinated side chains. It catalyzes water electro-oxidation efficiently at neutral pH, with an overpotential of 390 mV and a turnover frequency (TOF) of 1.83 s-1 in the absence of soluble Co salts. The catalyst can be immobilized through physisorption, and it remains stable in prolonged electrolysis experiments. © 2016 American Chemical Society.

  20. Stable solar-driven oxidation of water by semiconducting photoanodes protected by transparent catalytic nickel oxide films

    KAUST Repository

    Sun, Ke

    2015-03-11

    Reactively sputtered nickel oxide (NiOx) films provide transparent, antireflective, electrically conductive, chemically stable coatings that also are highly active electrocatalysts for the oxidation of water to O2(g). These NiOx coatings provide protective layers on a variety of technologically important semiconducting photoanodes, including textured crystalline Si passivated by amorphous silicon, crystalline n-type cadmium telluride, and hydrogenated amorphous silicon. Under anodic operation in 1.0 M aqueous potassium hydroxide (pH 14) in the presence of simulated sunlight, the NiOx films stabilized all of these self-passivating, high-efficiency semiconducting photoelectrodes for >100 h of sustained, quantitative solar-driven oxidation of water to O2(g). © 2015, National Academy of Sciences. All rights reserved.

  1. Estimating Past Temperature Change in Antarctica Based on Ice Core Stable Water Isotope Diffusion

    Science.gov (United States)

    Kahle, E. C.; Markle, B. R.; Holme, C.; Jones, T. R.; Steig, E. J.

    2017-12-01

    The magnitude of the last glacial-interglacial transition is a key target for constraining climate sensitivity on long timescales. Ice core proxy records and general circulation models (GCMs) both provide insight on the magnitude of climate change through the last glacial-interglacial transition, but appear to provide different answers. In particular, the magnitude of the glacial-interglacial temperature change reconstructed from East Antarctic ice-core water-isotope records is greater ( 9 degrees C) than that from most GCM simulations ( 6 degrees C). A possible source of this difference is error in the linear-scaling of water isotopes to temperature. We employ a novel, nonlinear temperature-reconstruction technique using the physics of water-isotope diffusion to infer past temperature. Based on new, ice-core data from the South Pole, this diffusion technique suggests East Antarctic temperature change was smaller than previously thought. We are able to confirm this result using a simple, water-isotope fractionation model to nonlinearly reconstruct temperature change at ice core locations across Antarctica based on combined oxygen and hydrogen isotope ratios. Both methods produce a temperature change of 6 degrees C for South Pole, agreeing with GCM results for East Antarctica. Furthermore, both produce much larger changes in West Antarctica, also in agreement with GCM results and independent borehole thermometry. These results support the fidelity of GCMs in simulating last glacial maximum climate, and contradict the idea, based on previous work, that the climate sensitivity of current GCMs is too low.

  2. Determination of stable and radioactive isotopes in rain water for the equatorial and Sahel zones

    International Nuclear Information System (INIS)

    Baudet, J.; Lesne, H.

    1975-01-01

    The extension of desert zones to detriment of Sahel zones lead to look for the circuit followed by water vapor between its principal source, i.e. the Guinea Gulf, and the place where it is changed in precipitation. Samples of rainwater have been collected in Abidjan, Ouagadougou, and Niamey when the Intertropical Front was beginning its moving down towards the South, i.e. at the end of the rainy season for the Sahel zone, and at the beginning of the small rainy season for the equatorial zone. The analysis of these tritium, deuterium and oxygen-18 contents show that: the rains collected in Abidjan comes mainly from Ocean; the rains collected in Ouagadougou and Niamey have followed a long journey above the continent, as shown by the tritium content. The water evaporated in the Guinea Gulf is condensed in the convergence zone above Cameroon, and mixed with re-evaporated continental water. The content of one of the Ouagadougou sample shows that the rain issued from a local cumulonimbus has drawn a part of its water from the stratosphere [fr

  3. STABLE ISOTOPE ANALYSIS OF MTBE TO EVALUATE THE SOURCE OF TBA IN GROUND WATER

    Science.gov (United States)

    Although tert-butyl alcohol (TBA) has not been used as a fuel oxygenate in Orange County, California, the concentrations of TBA in ground water at gasoline spill sites are high compared those of the conventional fuel oxygenate methyl tert-butyl ether (MTBE). In the year 2002, th...

  4. The influence of the synoptic regime on stable water isotopes in precipitation at Dome C, East Antarctica

    Directory of Open Access Journals (Sweden)

    E. Schlosser

    2017-10-01

    Full Text Available The correct derivation of paleotemperatures from ice cores requires exact knowledge of all processes involved before and after the deposition of snow and the subsequent formation of ice. At the Antarctic deep ice core drilling site Dome C, a unique data set of daily precipitation amount, type, and stable water isotope ratios is available that enables us to study in detail atmospheric processes that influence the stable water isotope ratio of precipitation. Meteorological data from both automatic weather station and a mesoscale atmospheric model were used to investigate how different atmospheric flow patterns determine the precipitation parameters. A classification of synoptic situations that cause precipitation at Dome C was established and, together with back-trajectory calculations, was utilized to estimate moisture source areas. With the resulting source area conditions (wind speed, sea surface temperature, and relative humidity as input, the precipitation stable isotopic composition was modeled using the so-called Mixed Cloud Isotope Model (MCIM. The model generally underestimates the depletion of 18O in precipitation, which was not improved by using condensation temperature rather than inversion temperature. Contrary to the assumption widely used in ice core studies, a more northern moisture source does not necessarily mean stronger isotopic fractionation. This is due to the fact that snowfall events at Dome C are often associated with warm air advection due to amplification of planetary waves, which considerably increases the site temperature and thus reduces the temperature difference between source area and deposition site. In addition, no correlation was found between relative humidity at the moisture source and the deuterium excess in precipitation. The significant difference in the isotopic signal of hoarfrost and diamond dust was shown to disappear after removal of seasonality. This study confirms the results of an earlier study

  5. The influence of the synoptic regime on stable water isotopes in precipitation at Dome C, East Antarctica

    Science.gov (United States)

    Schlosser, Elisabeth; Dittmann, Anna; Stenni, Barbara; Powers, Jordan G.; Manning, Kevin W.; Masson-Delmotte, Valérie; Valt, Mauro; Cagnati, Anselmo; Grigioni, Paolo; Scarchilli, Claudio

    2017-10-01

    The correct derivation of paleotemperatures from ice cores requires exact knowledge of all processes involved before and after the deposition of snow and the subsequent formation of ice. At the Antarctic deep ice core drilling site Dome C, a unique data set of daily precipitation amount, type, and stable water isotope ratios is available that enables us to study in detail atmospheric processes that influence the stable water isotope ratio of precipitation. Meteorological data from both automatic weather station and a mesoscale atmospheric model were used to investigate how different atmospheric flow patterns determine the precipitation parameters. A classification of synoptic situations that cause precipitation at Dome C was established and, together with back-trajectory calculations, was utilized to estimate moisture source areas. With the resulting source area conditions (wind speed, sea surface temperature, and relative humidity) as input, the precipitation stable isotopic composition was modeled using the so-called Mixed Cloud Isotope Model (MCIM). The model generally underestimates the depletion of 18O in precipitation, which was not improved by using condensation temperature rather than inversion temperature. Contrary to the assumption widely used in ice core studies, a more northern moisture source does not necessarily mean stronger isotopic fractionation. This is due to the fact that snowfall events at Dome C are often associated with warm air advection due to amplification of planetary waves, which considerably increases the site temperature and thus reduces the temperature difference between source area and deposition site. In addition, no correlation was found between relative humidity at the moisture source and the deuterium excess in precipitation. The significant difference in the isotopic signal of hoarfrost and diamond dust was shown to disappear after removal of seasonality. This study confirms the results of an earlier study carried out at Dome

  6. Fabrication of Water Jet Resistant and Thermally Stable Superhydrophobic Surfaces by Spray Coating of Candle Soot Dispersion.

    Science.gov (United States)

    Qahtan, Talal F; Gondal, Mohammed A; Alade, Ibrahim O; Dastageer, Mohammed A

    2017-08-08

    A facile synthesis method for highly stable carbon nanoparticle (CNP) dispersion in acetone by incomplete combustion of paraffin candle flame is presented. The synthesized CNP dispersion is the mixture of graphitic and amorphous carbon nanoparticles of the size range of 20-50 nm and manifested the mesoporosity with an average pore size of 7 nm and a BET surface area of 366 m 2 g -1 . As an application of this material, the carbon nanoparticle dispersion was spray coated (spray-based coating) on a glass surface to fabricate superhydrophobic (water contact angle > 150° and sliding angle fabricated from direct candle flame soot deposition (candle-based coating). This study proved that water jet resistant and thermally stable superhydrophobic surfaces can be easily fabricated by simple spray coating of CNP dispersion gathered from incomplete combustion of paraffin candle flame and this technique can be used for different applications with the potential for the large scale fabrication.

  7. Use of water stable isotopes in climatology and paleoclimatology illustrated from polar ice cores studies

    International Nuclear Information System (INIS)

    Jouzel, J.; Lorius, C.

    1994-01-01

    The isotopic content of ancient waters (deuterium and oxygen 18) gives a key access to past climatic changes. An essentially linear relationship exists between the isotopic content of a precipitation and the temperature of the site (at least for medium and high latitudes). This link between water isotope atmospheric cycle and climate is presented through various isotopic models and illustrated from the deuterium profile obtained along the Vostok ice core in East Antarctica. This 2 km record which covers a full glacial-interglacial cycle (160000 years) confirms the existence of a link between insolation changes and climate (Milankovitch theory). It shows also that the greenhouse effect has played a role in glacial-interglacial changes in amplifying this orbital forcing. (authors). 10 figs., 23 refs

  8. Behavior of radon, chemical compounds and stable elements in underground water

    International Nuclear Information System (INIS)

    Lopez R, N.; Segovia, N.; Lopez, M.B.E.; Pena, P.; Armienta, M.A.; Godinez, L.; Seidel, J.L.

    2001-01-01

    The radon behavior, chemical compounds, major and trace elements in water samples of four springs and three wells of urban and agricultural zones around the Jocotitlan volcano and El Oro region was determined, both of them located in the medium part of the Mexican neo-volcanic axis. The 222 Rn was measured by the liquid scintillation method, the analysis of major components was realized with conventional chemical techniques, while the trace elements were quantified using an Icp-Ms. The average values of the radon concentrations obtained during one year were constant relatively, in an interval from 0.97 to 4.99 Bq/lt indicating a fast transport from the reload area toward the sampling points. the compounds, major and trace elements showed differences which indicate distinct origins of water from the site studies. (Author)

  9. Dissolved stable noble gas measurements from primary water of Paks NPP

    International Nuclear Information System (INIS)

    Palcsu, L.; Molnar, M.; Szanto, Zs.; Svingor, E.; Futo, I.; Pinter, T.

    2001-01-01

    A sampling and measuring method of noble gases from the primary water circuit of a VVER type NPP was developed to provide relevant information about the kilter of heating rods and detailed additional information about some working parameters. The helium concentrations and 3 He/ 4 He ratios was used to estimate the content of tritium and alpha emitting isotopes of the primary water. By argon content measurements the air penetration and the required hydrazine amount for the oxygen absorption could be estimated with high accuracy. Continuous monitoring of the concentration and isotope ratios of Xe and Kr in the dissolved gas is proved to be a good tool for high sensitivity detection of small leakage of fuel elements. In case of block-3 xenon surplus was detected. The results indicate possible leakage of fuel rods.(author)

  10. Stable silicon isotope signatures of marine pore waters - Biogenic opal dissolution versus authigenic clay mineral formation

    Science.gov (United States)

    Ehlert, Claudia; Doering, Kristin; Wallmann, Klaus; Scholz, Florian; Sommer, Stefan; Grasse, Patricia; Geilert, Sonja; Frank, Martin

    2016-10-01

    Dissolved silicon isotope compositions have been analysed for the first time in pore waters (δ30SiPW) of three short sediment cores from the Peruvian margin upwelling region with distinctly different biogenic opal content in order to investigate silicon isotope fractionation behaviour during early diagenetic turnover of biogenic opal in marine sediments. The δ30SiPW varies between +1.1‰ and +1.9‰ with the highest values occurring in the uppermost part close to the sediment-water interface. These values are of the same order or higher than the δ30Si of the biogenic opal extracted from the same sediments (+0.3‰ to +1.2‰) and of the overlying bottom waters (+1.1‰ to +1.5‰). Together with dissolved silicic acid concentrations well below biogenic opal saturation, our collective observations are consistent with the formation of authigenic alumino-silicates from the dissolving biogenic opal. Using a numerical transport-reaction model we find that approximately 24% of the dissolving biogenic opal is re-precipitated in the sediments in the form of these authigenic phases at a relatively low precipitation rate of 56 μmol Si cm-2 yr-1. The fractionation factor between the precipitates and the pore waters is estimated at -2.0‰. Dissolved and solid cation concentrations further indicate that off Peru, where biogenic opal concentrations in the sediments are high, the availability of reactive terrigenous material is the limiting factor for the formation of authigenic alumino-silicate phases.

  11. Archival processes of the water stable isotope signal in East Antarctic ice cores

    Science.gov (United States)

    Casado, Mathieu; Landais, Amaelle; Picard, Ghislain; Münch, Thomas; Laepple, Thomas; Stenni, Barbara; Dreossi, Giuliano; Ekaykin, Alexey; Arnaud, Laurent; Genthon, Christophe; Touzeau, Alexandra; Masson-Delmotte, Valerie; Jouzel, Jean

    2018-05-01

    The oldest ice core records are obtained from the East Antarctic Plateau. Water isotopes are key proxies to reconstructing past climatic conditions over the ice sheet and at the evaporation source. The accuracy of climate reconstructions depends on knowledge of all processes affecting water vapour, precipitation and snow isotopic compositions. Fractionation processes are well understood and can be integrated in trajectory-based Rayleigh distillation and isotope-enabled climate models. However, a quantitative understanding of processes potentially altering snow isotopic composition after deposition is still missing. In low-accumulation sites, such as those found in East Antarctica, these poorly constrained processes are likely to play a significant role and limit the interpretability of an ice core's isotopic composition. By combining observations of isotopic composition in vapour, precipitation, surface snow and buried snow from Dome C, a deep ice core site on the East Antarctic Plateau, we found indications of a seasonal impact of metamorphism on the surface snow isotopic signal when compared to the initial precipitation. Particularly in summer, exchanges of water molecules between vapour and snow are driven by the diurnal sublimation-condensation cycles. Overall, we observe in between precipitation events modification of the surface snow isotopic composition. Using high-resolution water isotopic composition profiles from snow pits at five Antarctic sites with different accumulation rates, we identified common patterns which cannot be attributed to the seasonal variability of precipitation. These differences in the precipitation, surface snow and buried snow isotopic composition provide evidence of post-deposition processes affecting ice core records in low-accumulation areas.

  12. The use of stable isotopes to trace the impact of landfill gases on environmental waters

    International Nuclear Information System (INIS)

    Kennel, P.; Hendy, C.H.

    1997-01-01

    The process of anaerobic fermentation leading to methanogenisis in landfills produces isotopically depleted methane and isotopically enriched carbon dioxide. While the inflammability of methane is a recognised environmental hazard, the impact of the carbon dioxide produced has not been recognised. Unlike methane, the carbon dioxide is very soluble in waters it comes in contact with and unlike leachates it is not contained by the engineered structure of modern landfills. The carbon dioxide gas has the potential of dissolving in ground waters, lowering their pH and degrading their water quality. We have used up to +13 per thousand delta/sup 13/C values of the CO/sub 2/ gas to trace and quantify the effect of the enhanced P/sub CO2/ on groundwater. The downstream consequences of enhanced P/sub CO2/ on groundwater quality also depend on matrix lithology, being more significant for basaltic environments such as those typical of Auckland landfills than for the rhyolitic sands and gravels common in Waikato landfills. (author)

  13. Testing and modelling of a novel oil-free co-rotating scroll machine with water injection

    International Nuclear Information System (INIS)

    Mendoza, Luis Carlos; Lemofouet, Sylvain; Schiffmann, Jürg

    2017-01-01

    Highlights: • Performance of novel oil-free co-rotating scroll expander presented. • Water injection allows reaching quasi-isothermal expansion process. • Comparison between experimental data, semi-empirical and deterministic models. • Flank leakage, water injection and rotor speed effects have been analyzed experimentally. • Design guidelines for co-rotating scroll improvement proposed. - Abstract: Efficient compressed air energy storage requires reversible isothermal compression and expansion devices. The isothermal compression and expansion processes can either be approached by several stages with intercooling or by the more convenient injection of a liquid, often water. While volumetric machines are readily available for dry processes the compression and expansion of a gas with the presence of liquid is still problematic. The concept of a co-rotating scroll has been identified as a promising technology to cope with the presence of liquid. The current paper discusses the first experimental results of an oil-free co-rotating scroll prototype tested in expansion mode on a wide range of rotational speeds, varying water injection flow rates and with different nominal flank clearances. A maximal overall isothermal efficiency of 34% and a maximum output power of 1.74 kW_e_l were measured with this first prototype, providing the proof of the technical feasibility of the oil-free co-rotating scroll expander concept. The experimental data indicate a positive effect of water injection suggesting good heat transfer behaviour between the water and the air in the individual chambers, which is a result of the relatively long residence time compared to other volumetric concepts. The experimental sensitivity analysis yields a strong dependency of the machine performance on both the nominal flank clearance and on the injected water rate. The analysis through a semi-empirical model suggests the inversion of a classical trend, i.e. the increase in total leakage area with

  14. Hydrogen and Oxygen stable isotope analysis of water in fruits and vegetables by using cavity ring-down spectrometry

    International Nuclear Information System (INIS)

    Suzuki, Yaeko

    2016-01-01

    We determined oxygen and hydrogen stable isotope ratios (δ"1"8O and δD) of water in fruits (citrus) and vegetables (ginger) using cavity ring-down spectrometry (CRDS) for assessment of their authenticity. The δ"1"8O and δD values of fruits and straight juice had higher than those of concentrated juice. The citrus fruits from Japan had relatively lower δ"1"8O and δD values of than those from Australia, South Africa and the United States. The δD values and d-excess of ginger samples from Japan were relatively higher than those of ginger samples from China. The δ"1"8O and δD values of water in fruits and vegetables would be representative of the ambient water, depending on geographical parameters such as the latitude and altitude. These results suggested that δ"1"8O and δD values of water in fruits and vegetables by using CRDS would be potentially useful for assessment of their authenticity. (author)

  15. Unit operation optimization for the manufacturing of botanical injections using a design space approach: a case study of water precipitation.

    Science.gov (United States)

    Gong, Xingchu; Chen, Huali; Chen, Teng; Qu, Haibin

    2014-01-01

    Quality by design (QbD) concept is a paradigm for the improvement of botanical injection quality control. In this work, water precipitation process for the manufacturing of Xueshuantong injection, a botanical injection made from Notoginseng Radix et Rhizoma, was optimized using a design space approach as a sample. Saponin recovery and total saponin purity (TSP) in supernatant were identified as the critical quality attributes (CQAs) of water precipitation using a risk assessment for all the processes of Xueshuantong injection. An Ishikawa diagram and experiments of fractional factorial design were applied to determine critical process parameters (CPPs). Dry matter content of concentrated extract (DMCC), amount of water added (AWA), and stirring speed (SS) were identified as CPPs. Box-Behnken designed experiments were carried out to develop models between CPPs and process CQAs. Determination coefficients were higher than 0.86 for all the models. High TSP in supernatant can be obtained when DMCC is low and SS is high. Saponin recoveries decreased as DMCC increased. Incomplete collection of supernatant was the main reason for the loss of saponins. Design space was calculated using a Monte-Carlo simulation method with acceptable probability of 0.90. Recommended normal operation region are located in DMCC of 0.38-0.41 g/g, AWA of 3.7-4.9 g/g, and SS of 280-350 rpm, with a probability more than 0.919 to attain CQA criteria. Verification experiment results showed that operating DMCC, SS, and AWA within design space can attain CQA criteria with high probability.

  16. Unit operation optimization for the manufacturing of botanical injections using a design space approach: a case study of water precipitation.

    Directory of Open Access Journals (Sweden)

    Xingchu Gong

    Full Text Available Quality by design (QbD concept is a paradigm for the improvement of botanical injection quality control. In this work, water precipitation process for the manufacturing of Xueshuantong injection, a botanical injection made from Notoginseng Radix et Rhizoma, was optimized using a design space approach as a sample. Saponin recovery and total saponin purity (TSP in supernatant were identified as the critical quality attributes (CQAs of water precipitation using a risk assessment for all the processes of Xueshuantong injection. An Ishikawa diagram and experiments of fractional factorial design were applied to determine critical process parameters (CPPs. Dry matter content of concentrated extract (DMCC, amount of water added (AWA, and stirring speed (SS were identified as CPPs. Box-Behnken designed experiments were carried out to develop models between CPPs and process CQAs. Determination coefficients were higher than 0.86 for all the models. High TSP in supernatant can be obtained when DMCC is low and SS is high. Saponin recoveries decreased as DMCC increased. Incomplete collection of supernatant was the main reason for the loss of saponins. Design space was calculated using a Monte-Carlo simulation method with acceptable probability of 0.90. Recommended normal operation region are located in DMCC of 0.38-0.41 g/g, AWA of 3.7-4.9 g/g, and SS of 280-350 rpm, with a probability more than 0.919 to attain CQA criteria. Verification experiment results showed that operating DMCC, SS, and AWA within design space can attain CQA criteria with high probability.

  17. Viscoelastic diamine surfactant for stable carbon dioxide/water foams over a wide range in salinity and temperature.

    Science.gov (United States)

    Elhag, Amro S; Da, Chang; Chen, Yunshen; Mukherjee, Nayan; Noguera, Jose A; Alzobaidi, Shehab; Reddy, Prathima P; AlSumaiti, Ali M; Hirasaki, George J; Biswal, Sibani L; Nguyen, Quoc P; Johnston, Keith P

    2018-07-15

    The viscosity and stability of CO 2 /water foams at elevated temperature can be increased significantly with highly viscoelastic aqueous lamellae. The slow thinning of these viscoelastic lamellae leads to greater foam stability upon slowing down Ostwald ripening and coalescence. In the aqueous phase, the viscoelasticity may be increased by increasing the surfactant tail length to form more entangled micelles even at high temperatures and salinity. Systematic measurements of the steady state shear viscosity of aqueous solutions of the diamine surfactant (C 16-18 N(CH 3 )C 3 N(CH 3 ) 2 ) were conducted at varying surfactant concentrations and salinity to determine the parameters for formation of entangled wormlike micelles. The apparent viscosity and stability of CO 2 /water foams were compared for systems with viscoelastic entangled micellar aqueous phases relative to those with much less viscous spherical micelles. We demonstrated for the first time stable CO 2 /water foams at temperatures up to 120 °C and CO 2 volumetric fractions up to 0.98 with a single diamine surfactant, C 16-18 N(CH 3 )C 3 N(CH 3 ) 2 . The foam stability was increased by increasing the packing parameter of the surfactant with a long tail and methyl substitution on the amine to form entangled viscoelastic wormlike micelles in the aqueous phase. The foam was more viscous and stable compared to foams with spherical micelles in the aqueous lamellae as seen with C 12-14 N(EO) 2 and C 16-18 N(EO)C 3 N(EO) 2 . Copyright © 2018. Published by Elsevier Inc.

  18. [Difference of water relationships of poplar trees in Zhangbei County, Hebei, China based on stable isotope and thermal dissipation method].

    Science.gov (United States)

    Miao, Bo; Meng, Ping; Zhang, Jin Song; He, Fang Jie; Sun, Shou Jia

    2017-07-18

    The water sources and transpiration of poplar trees in Zhangbei County were measured using stable hydrogen isotope and thermal dissipation method. The differences in water relationships between dieback and non-dieback poplar trees were analyzed. The results showed that the dieback trees mainly used shallow water from 0-30 cm soil layer during growing season while the non-dieback trees mainly used water from 30-80 cm soil layer. There was a significant difference in water source between them. The non-dieback trees used more water from middle and deep soil layers than that of the dieback trees during the dry season. The percentage of poplar trees using water from 0-30 cm soil layer increased in wet season, and the increase of dieback trees was higher than that of non-dieback trees. The contributions of water from 30-180 cm soil layer of dieback and non-dieback trees both decreased in wet season. The sap flow rate of non-dieback trees was higher than that of dieback trees. There was a similar variation tend of sap flow rate between dieback and non-dieback trees in different weather conditions, but the start time of sap flow of non-dieback trees was earlier than that of dieback trees. Correlation analysis showed that the sap flow rate of either dieback or non-dieback poplar trees strongly related to soil temperature, wind speed, photosynthetically active radiation, relative humidity and air temperature. The sap flow rate of die-back poplar trees strongly negatively related to soil temperature and relative humidity, and strongly positively related to the other factors. The sap flow rate of non-dieback poplar trees only strongly negatively related to relative humidity but positively related to the other factors. The results revealed transpiration of both poplar trees was easily affected by environmental factors. The water consumption of dieback trees was less than non-dieback trees because the cumulative sap flow amount of dieback trees was lower. Reduced transpiration

  19. Effects of Water Vapor on the Data Quality of the Stable Oxygen Isotopic Ratio of Atmospheric Carbon Dioxide

    Science.gov (United States)

    Evans, C. U.; White, J. W.; Vaughn, B.; Tans, P. P.; Pardo, L.

    2007-12-01

    The stable oxygen isotopic ratio of carbon dioxide can potentially track fundamental indicators of environmental change such as the balance between photosynthesis and respiration on regional to global scales. The Stable Isotope Laboratory (SIL) at the Institute of Arctic and Alpine Research (INSTAAR), University of Colorado at Boulder, has measured the stable isotopes of atmospheric carbon dioxide from more than 60 NOAA/Earth System Research Laboratory (ESRL) air flask-sampling sites since the early 1990s. If air is sampled without drying, oxygen can exchange between carbon dioxide and water in the flasks, entirely masking the desired signal. An attempt to investigate how water vapor is affecting the δ18O signal is accomplished by comparing the SIL measurements with specific humidity, calculated from the National Climatic Data Center (NCDC) global integrated surface hourly temperature and dew point database, at the time of sampling. Analysis of sites where samples have been collected initially without drying, and subsequently with a drying kit, in conjunction with the humidity data, has led to several conclusions. Samples that initially appear isotopically unaltered, in that their δ18O values are within the expected range, are being subtly influenced by the water vapor in the air. At Bermuda and other tropical to semi-tropical sites, the 'wet' sampling values have a seasonal cycle that is strongly anti-correlated to the specific humidity, while the 'dry' values have a seasonal cycle that is shifted earlier than the specific humidity cycle by 1-2 months. The latter phasing is expected given the seasonal phasing between climate over the ocean and land, while the former is consistent with a small, but measurable isotope exchange in the flasks. In addition, we note that there is a strong (r > 0.96) correlation between the average specific humidity and the percent of rejected samples for 'wet' sampling. This presents an opportunity for determining a threshold of

  20. An injectable hybrid nanoparticle-in-oil-in-water submicron emulsion for improved delivery of poorly soluble drugs

    Science.gov (United States)

    Wang, Shuo; Wang, Hua; Liang, Wenquan; Huang, Yongzhuo

    2012-04-01

    Poor drugability problems are commonly seen in a class of chemical entities with poor solubility in water and oil, and moreover, physicochemical instability of these compounds poses extra challenges in design of dosage forms. Such problems contribute a significant high failure rate in new drug development. A hybrid nanoparicle-in-oil-in-water (N/O/W) submicron emulsion was proposed for improved delivery of poorly soluble and unstable drugs (e.g., dihydroartemisinin (DHA)). DHA is known for its potent antimalarial effect and antitumor activity. However, its insolubility and instability impose big challenges for formulations, and so far, no injectable dosage forms are clinically available yet. Therefore, an injectable DHA N/O/W system was developed. Unlike other widely-explored systems (e.g., liposomes, micelles, and emulsions), in which low drug load and only short-term storage are often found, the hybrid submicron emulsion possesses three-fold higher drug-loading capacity than the conventional O/W emulsion. Of note, it can be manufactured into a freeze-drying form and can render its storage up to 6 months even in room temperature. The in vivo studies demonstrated that the PK profiles were significantly improved, and this injectable system was effective in suppressing tumor growth. The strategy provides a useful solution to effective delivery of such a class of drugs.

  1. Groundwater discharge by evapotranspiration, flow of water in unsaturated soil, and stable isotope water sourcing in areas of sparse vegetation, Amargosa Desert, Nye County, Nevada

    Science.gov (United States)

    Moreo, Michael T.; Andraski, Brian J.; Garcia, C. Amanda

    2017-08-29

    This report documents methodology and results of a study to evaluate groundwater discharge by evapotranspiration (GWET) in sparsely vegetated areas of Amargosa Desert and improve understanding of hydrologic-continuum processes controlling groundwater discharge. Evapotranspiration and GWET rates were computed and characterized at three sites over 2 years using a combination of micrometeorological, unsaturated zone, and stable-isotope measurements. One site (Amargosa Flat Shallow [AFS]) was in a sparse and isolated area of saltgrass (Distichlis spicata) where the depth to groundwater was 3.8 meters (m). The second site (Amargosa Flat Deep [AFD]) was in a sparse cover of predominantly shadscale (Atriplex confertifolia) where the depth to groundwater was 5.3 m. The third site (Amargosa Desert Research Site [ADRS]), selected as a control site where GWET is assumed to be zero, was located in sparse vegetation dominated by creosote bush (Larrea tridentata) where the depth to groundwater was 110 m.Results indicated that capillary rise brought groundwater to within 0.9 m (at AFS) and 3 m (at AFD) of land surface, and that GWET rates were largely controlled by the slow but relatively persistent upward flow of water through the unsaturated zone in response to atmospheric-evaporative demands. Greater GWET at AFS (50 ± 20 millimeters per year [mm/yr]) than at AFD (16 ± 15 mm/yr) corresponded with its shallower depth to the capillary fringe and constantly higher soil-water content. The stable-isotope dataset for hydrogen (δ2H) and oxygen (δ18O) illustrated a broad range of plant-water-uptake scenarios. The AFS saltgrass and AFD shadscale responded to changing environmental conditions and their opportunistic water use included the time- and depth-variable uptake of unsaturated-zone water derived from a combination of groundwater and precipitation. These results can be used to estimate GWET in other areas of Amargosa Desert where hydrologic conditions are similar.

  2. Developing Optimal Procedure of Emergency Outside Cooling Water Injection for APR1400 Extended SBO Scenario Using MARS Code

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jong Rok; Oh, Seung Jong [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    In this study, we examined optimum operator actions to mitigate extended SBO using MARS code. Particularly, this paper focuses on analyzing outside core cooling water injection scenario, and aimed to develop optimal extended SBO procedure. Supplying outside emergency cooling water is the key feature of flexible strategy in extended SBO situation. An optimum strategy to maintain core cooling is developed for typical extended SBO. MARS APR1400 best estimate model was used to find optimal procedure. Also RCP seal leakage effect was considered importantly. Recent Fukushima accident shows the importance of mitigation capability against extended SBO scenarios. In Korea, all nuclear power plants incorporated various measures against Fukushima-like events. For APR1400 NPP, outside connectors are installed to inject cooling water using fire trucks or portable pumps. Using these connectors, outside cooling water can be provided to reactor, steam generators (SG), containment spray system, and spent fuel pool. In U. S., similar approach is chosen to provide a diverse and flexible means to prevent fuel damage (core and SFP) in external event conditions resulting in extended loss of AC power and loss of ultimate heat sink. Hence, hardware necessary to cope with extended SBO is already available for APR1400. However, considering the complex and stressful condition encountered by operators during extended SBO, it is important to develop guidelines/procedures to best cope with the event.

  3. Thermal shock studies associated with injection of emergency core coolant in pressurized water reactors

    International Nuclear Information System (INIS)

    Cheverton, R.D.; Bolt, S.E.; Iskander, S.K.

    1977-01-01

    Studies to determine the accuracy of calculational techniques for predicting crack initiation and arrest in PWR vessels due to thermal shock from ECC injection are described. The reference calculational model is reviewed, the experimental program and facilities are described, and some thermal shock experiments and results are discussed

  4. Reverse radiometric flow injection analysis (RFIA) of radioactive waste-waters with an ASIA (Ismatec) analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Myint, U; Win, N; San, K; Han, B; Myoe, K M [Yangon Univ. (Myanmar). Dept. of Chemistry; Toelgyessy, J [Slovak Technical Univ., Bratislava (Slovakia). Dept. of Environmental Science

    1994-07-01

    A new application of reverse radiometric flow injection analysis is described. RFIA was used for the analysis of radioactive wastewaters. ASIA (Ismatec) analyzer with NaI(Tl) scintillation detector was used in the study of analysis of [sup 131]I containing waste-aster. (author) 4 refs.; 3 figs.

  5. Numerical study of hot-leg ECC injection into the upper plenum of a pressurized water reactor

    International Nuclear Information System (INIS)

    Daly, B.J.; Torrey, M.D.; Rivard, W.C.

    1981-01-01

    In certain pressurized water reactor (PWR) designs, emergency core coolant (ECC) is injected through the hot legs into the upper plenum. The condensation of steam on this subcooled liquid stream reduces the pressure in the hot legs and upper plenum and thereby affects flow conditions throughout the reactor. In the present study, we examine countercurrent steam-water flow in the hot leg to determine the deceleration of the ECC flow that results from an adverse pressure gradient and from momentum exchange from the steam by interfacial drag and condensation. For the parameters examined in the study, water flow reversal is observed for a pressure drop of 22 to 32 mBar over the 1.5 m hot leg. We have also performed a three-dimensional study of subcooled water injection into air and steam environments of the upper plenum. The ECC water is deflected by an array of cylindrical guide tubes in its passage through the upper plenum. Comparisons of the air-water results with data obtained in a full scale experiment shows reasonable agreement, but indicates that there may be too much resistance to horizontal flow about the columns because of the use of a stair-step representation of the cylindrical guide tube cross section. Calculations of flow past single columns of stair-step, square and circular cross section do indicate excessive water deeentrainment by the noncircular column. This has prompted the use of an arbitrary mesh computational procedure to more accuratey represent the circular cross-section guide tubes. 15 figures

  6. Rayleigh-Plesset equation of the bubble stable cavitation in water: A nonequilibrium all-atom molecular dynamics simulation study

    Science.gov (United States)

    Man, Viet Hoang; Li, Mai Suan; Derreumaux, Philippe; Nguyen, Phuong H.

    2018-03-01

    The Rayleigh-Plesset (RP) equation was derived from the first principles to describe the bubble cavitation in liquids in terms of macroscopic hydrodynamics. A number of nonequilibrium molecular dynamics studies have been carried out to validate this equation in describing the bubble inertial cavitation, but their results are contradictory and the applicability of the RP equation still remains to be examined, especially for the stable cavitation. In this work, we carry out nonequilibrium all-atom simulation to validate the applicability of the RP equation in the description of the stable cavitation of nano-sized bubbles in water. We show that although microscopic effects are not explicitly included, this equation still describes the dynamics of subnano-bubbles quite well as long as the contributions of various terms including inertial, surface tension, and viscosity are correctly taken into account. These terms are directly and inversely proportional to the amplitude and period of the cavitation, respectively. Thus, their contributions to the RP equation depend on these two parameters. This may explain the discrepancy between the current results obtained using different parameters. Finally, the accuracy of the RP equation in the current mathematical modeling studies of the ultrasound-induced blood-brain-barrier experiments is discussed in some detail.

  7. Stable isotope variations (δ18O and δD) in modern waters across the Andean Plateau

    Science.gov (United States)

    Bershaw, John; Saylor, Joel E.; Garzione, Carmala N.; Leier, Andrew; Sundell, Kurt E.

    2016-12-01

    Environmental parameters that influence the isotopic composition of meteoric water (δ18O and δD) are well characterized up the windward side of mountains, where orographic precipitation results in a predictable relationship between the isotopic composition of precipitation and elevation. The topographic and climatic evolution of the Andean Plateau and surrounding regions has been studied extensively by exploiting this relationship through the use of paleowater proxies. However, interpretation on the plateau itself is challenged by a poor understanding of processes that fractionate isotopes during vapor transport and rainout, and by the relative contribution of unique moisture sources. Here, we present an extensive dataset of modern surface water samples for the northern Andean Plateau and surrounding regions to elucidate patterns and causes of isotope fractionation in this continental environment. These data show a progressive increase in δ18O of stream water west of the Eastern Cordillera (∼1‰/70 km), almost identical to the rate observed across the Tibetan Plateau, attributed to a larger fraction of recycled water in precipitation and/or increased evaporative enrichment downwind. This may lead to underestimates of paleoelevation, particularly for sites deep into the rainshadow of the Eastern Cordilleran crest. That said, elevation is a primary control on the isotopic composition of surface waters across the entire Andean Plateau and its flanks when considering the most negative δ18O values, highlighting the need for sufficiently large datasets to distinguish minimally evaporated samples. There is a general increase in δ18O on the plateau from north to south, concomitant with an increase in aridity and decrease in convective moistening (amount effect). Lastly, stable isotope and seasonal precipitation patterns suggest easterlies provide the vast majority of moisture that falls as precipitation across the Andean Plateau and Western Cordillera, from Peru to

  8. Zooplankton trophic niches respond to different water types of the western Tasman Sea: A stable isotope analysis

    Science.gov (United States)

    Henschke, Natasha; Everett, Jason D.; Suthers, Iain M.; Smith, James A.; Hunt, Brian P. V.; Doblin, Martina A.; Taylor, Matthew D.

    2015-10-01

    The trophic relationships of 21 species from an oceanic zooplankton community were studied using stable isotopes of carbon and nitrogen. Zooplankton and suspended particulate organic matter (POM) were sampled in three different water types in the western Tasman Sea: inner shelf (IS), a cold core eddy (CCE) and a warm core eddy (WCE). δ15N values ranged from 3.9‰ for the parasitic copepod Sapphirina augusta to 10.2‰ for the euphausiid, Euphausia spinifera. δ13C varied from -22.6 to -19.4‰ as a result of the copepod Euchirella curticauda and E. spinifera. The isotopic composition of POM varied significantly among water types; as did the trophic enrichment of zooplankton over POM, with the lowest enrichment in the recently upwelled IS water type (0.5‰) compared to the warm core eddy (1.6‰) and cold core eddy (2.7‰). The WCE was an oligotrophic environment and was associated with an increased trophic level for omnivorous zooplankton (copepods and euphausiids) to a similar level as carnivorous zooplankton (chaetognaths). Therefore carnivory in zooplankton can increase in response to lower abundance and reduced diversity in their phytoplankton and protozoan prey. Trophic niche width comparisons across three zooplankton species: the salp Thalia democratica, the copepod Eucalanus elongatus and the euphausiid Thysanoessa gregaria, indicated that both niche partitioning and competition can occur within the zooplankton community. We have shown that trophic relationships among the zooplankton are dynamic and respond to different water types. The changes to the zooplankton isotopic niche, however, were still highly variable as result of oceanographic variation within water types.

  9. Putative new heat-stable cytotoxic and enterotoxic factors in culture supernatant of Escherichia coli isolated from drinking water

    Directory of Open Access Journals (Sweden)

    DA Ribeiro

    2011-01-01

    Full Text Available Enteric infections caused by the ingestion of contaminated water, especially by Escherichia coli, are important to define the virulence properties of these bacteria. Due to frequent infantile diarrhea in the city of Ouro Preto, Minas Gerais state, Brazil, the phenotypic and genotypic diarrheagenic properties of E. coli isolated from drinking water were studied. The culture supernatants of 39 (40% among a total of 97 E. coli isolates from drinking water were positive by suckling mouse assay and induced cytotoxic effects on Vero cells. The enterotoxic and cytotoxic activities were present in the fraction with less than 10 kDa and were not lost when heated up to 60°C and 100°C for 30 minutes. PCR assays showed that among these 39 Vero cytotoxigenic E. coli, four (10.2% were positive for ST II (estB and two (5% positive for αHly (hlyA. Gene amplification of SLT (stx 1, stx 2, ST I (estA, LT (eltI, eltII, EAST1 (astA, EHly (enhly and plasmid-encoded enterotoxin (pet were not observed. This heat-stable cytotoxic enterotoxin of E. coli is probably a new putative diarrheagenic virulence factor, as a toxin presenting these characteristics has not yet been described.

  10. Characterization of para-Nitrophenol-Degrading Bacterial Communities in River Water by Using Functional Markers and Stable Isotope Probing.

    Science.gov (United States)

    Kowalczyk, Agnieszka; Eyice, Özge; Schäfer, Hendrik; Price, Oliver R; Finnegan, Christopher J; van Egmond, Roger A; Shaw, Liz J; Barrett, Glyn; Bending, Gary D

    2015-10-01

    Microbial degradation is a major determinant of the fate of pollutants in the environment. para-Nitrophenol (PNP) is an EPA-listed priority pollutant with a wide environmental distribution, but little is known about the microorganisms that degrade it in the environment. We studied the diversity of active PNP-degrading bacterial populations in river water using a novel functional marker approach coupled with [(13)C6]PNP stable isotope probing (SIP). Culturing together with culture-independent terminal restriction fragment length polymorphism analysis of 16S rRNA gene amplicons identified Pseudomonas syringae to be the major driver of PNP degradation in river water microcosms. This was confirmed by SIP-pyrosequencing of amplified 16S rRNA. Similarly, functional gene analysis showed that degradation followed the Gram-negative bacterial pathway and involved pnpA from Pseudomonas spp. However, analysis of maleylacetate reductase (encoded by mar), an enzyme common to late stages of both Gram-negative and Gram-positive bacterial PNP degradation pathways, identified a diverse assemblage of bacteria associated with PNP degradation, suggesting that mar has limited use as a specific marker of PNP biodegradation. Both the pnpA and mar genes were detected in a PNP-degrading isolate, P. syringae AKHD2, which was isolated from river water. Our results suggest that PNP-degrading cultures of Pseudomonas spp. are representative of environmental PNP-degrading populations. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Large-scale spatial and interspecies differences in trace elements and stable isotopes in marine wild fish from Chinese waters

    International Nuclear Information System (INIS)

    Zhang, Wei; Wang, Wen-Xiong

    2012-01-01

    Highlights: ► A large-scale study on trace element levels in marine wild fish from Chinese waters. ► Spatial variation found for Al, As, Cd, Cr, Fe, Ni, Pb, but not for Ag, Cu, Mo, Se and Zn. ► The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb. ► No biomagnification occurred for any of the trace elements studied in marine fish. ► No obvious health risk from the intake of trace elements through fish consumption. - Abstract: We conducted a large scale investigation of twelve trace element levels and stable isotopes (δ 13 C and δ 15 N) in twenty-nine marine wild fish species collected from Chinese coastal waters. Trace element levels varied significantly with species. Clear spatial variations were found for Al, As, Cd, Cr, Fe, Ni, and Pb, whereas Ag, Cu, Mo, Se and Zn did not show much spatial variation. The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb, whereas the most southern waters (Haikou) contained the lowest concentrations of Al, Fe, and Pb. There was no correlation between log-transformed trace elements concentrations and δ 15 N values or δ 13 C values, indicating no biomagnification among these trace elements. The calculated hazard quotients (HQ) of 10 elements were less than 1, thus there was no obvious health risk from the intake of trace elements through marine wild fish consumption.

  12. Stable water isotopologue ratios in fog and cloud droplets of liquid clouds are not size-dependent

    Science.gov (United States)

    Spiegel, J.K.; Aemisegger, F.; Scholl, M.; Wienhold, F.G.; Collett, J.L.; Lee, T.; van Pinxteren, D.; Mertes, S.; Tilgner, A.; Herrmann, H.; Werner, Roland A.; Buchmann, N.; Eugster, W.

    2012-01-01

    In this work, we present the first observations of stable water isotopologue ratios in cloud droplets of different sizes collected simultaneously. We address the question whether the isotope ratio of droplets in a liquid cloud varies as a function of droplet size. Samples were collected from a ground intercepted cloud (= fog) during the Hill Cap Cloud Thuringia 2010 campaign (HCCT-2010) using a three-stage Caltech Active Strand Cloud water Collector (CASCC). An instrument test revealed that no artificial isotopic fractionation occurs during sample collection with the CASCC. Furthermore, we could experimentally confirm the hypothesis that the δ values of cloud droplets of the relevant droplet sizes (μm-range) were not significantly different and thus can be assumed to be in isotopic equilibrium immediately with the surrounding water vapor. However, during the dissolution period of the cloud, when the supersaturation inside the cloud decreased and the cloud began to clear, differences in isotope ratios of the different droplet sizes tended to be larger. This is likely to result from the cloud's heterogeneity, implying that larger and smaller cloud droplets have been collected at different moments in time, delivering isotope ratios from different collection times.

  13. Stable water isotopologue ratios in fog and cloud droplets of liquid clouds are not size-dependent

    Directory of Open Access Journals (Sweden)

    J. K. Spiegel

    2012-10-01

    Full Text Available In this work, we present the first observations of stable water isotopologue ratios in cloud droplets of different sizes collected simultaneously. We address the question whether the isotope ratio of droplets in a liquid cloud varies as a function of droplet size. Samples were collected from a ground intercepted cloud (= fog during the Hill Cap Cloud Thuringia 2010 campaign (HCCT-2010 using a three-stage Caltech Active Strand Cloud water Collector (CASCC. An instrument test revealed that no artificial isotopic fractionation occurs during sample collection with the CASCC. Furthermore, we could experimentally confirm the hypothesis that the δ values of cloud droplets of the relevant droplet sizes (μm-range were not significantly different and thus can be assumed to be in isotopic equilibrium immediately with the surrounding water vapor. However, during the dissolution period of the cloud, when the supersaturation inside the cloud decreased and the cloud began to clear, differences in isotope ratios of the different droplet sizes tended to be larger. This is likely to result from the cloud's heterogeneity, implying that larger and smaller cloud droplets have been collected at different moments in time, delivering isotope ratios from different collection times.

  14. Bacterioplankton communities of Crater Lake, OR: Dynamic changes with euphotic zone food web structure and stable deep water populations

    Science.gov (United States)

    Urbach, E.; Vergin, K.L.; Larson, G.L.; Giovannoni, S.J.

    2007-01-01

    The distribution of bacterial and archaeal species in Crater Lake plankton varies dramatically over depth and with time, as assessed by hybridization of group-specific oligonucleotides to RNA extracted from lakewater. Nonmetric, multidimensional scaling (MDS) analysis of relative bacterial phylotype densities revealed complex relationships among assemblages sampled from depth profiles in July, August and September of 1997 through 1999. CL500-11 green nonsulfur bacteria (Phylum Chloroflexi) and marine Group I crenarchaeota are consistently dominant groups in the oxygenated deep waters at 300 and 500 m. Other phylotypes found in the deep waters are similar to surface and mid-depth populations and vary with time. Euphotic zone assemblages are dominated either by ??-proteobacteria or CL120-10 verrucomicrobia, and ACK4 actinomycetes. MDS analyses of euphotic zone populations in relation to environmental variables and phytoplankton and zooplankton population structures reveal apparent links between Daphnia pulicaria zooplankton population densities and microbial community structure. These patterns may reflect food web interactions that link kokanee salmon population densities to community structure of the bacterioplankton, via fish predation on Daphnia with cascading consequences to Daphnia bacterivory and predation on bacterivorous protists. These results demonstrate a stable bottom-water microbial community. They also extend previous observations of food web-driven changes in euphotic zone bacterioplankton community structure to an oligotrophic setting. ?? 2007 Springer Science+Business Media B.V.

  15. Defining a stable water isotope framework for isotope hydrology application in a large trans-boundary watershed (Russian Federation/Ukraine).

    Science.gov (United States)

    Vystavna, Yuliya; Diadin, Dmytro; Huneau, Frédéric

    2018-05-01

    Stable isotopes of hydrogen ( 2 H) and oxygen ( 18 O) of the water molecule were used to assess the relationship between precipitation, surface water and groundwater in a large Russia/Ukraine trans-boundary river basin. Precipitation was sampled from November 2013 to February 2015, and surface water and groundwater were sampled during high and low flow in 2014. A local meteoric water line was defined for the Ukrainian part of the basin. The isotopic seasonality in precipitation was evident with depletion in heavy isotopes in November-March and an enrichment in April-October, indicating continental and temperature effects. Surface water was enriched in stable water isotopes from upstream to downstream sites due to progressive evaporation. Stable water isotopes in groundwater indicated that recharge occurs mainly during winter and spring. A one-year data set is probably not sufficient to report the seasonality of groundwater recharge, but this survey can be used to identify the stable water isotopes framework in a weakly gauged basin for further hydrological and geochemical studies.

  16. Strontium isotopes test long-term zonal isolation of injected and Marcellus formation water after hydraulic fracturing.

    Science.gov (United States)

    Kohl, Courtney A Kolesar; Capo, Rosemary C; Stewart, Brian W; Wall, Andrew J; Schroeder, Karl T; Hammack, Richard W; Guthrie, George D

    2014-08-19

    One concern regarding unconventional hydrocarbon production from organic-rich shale is that hydraulic fracture stimulation could create pathways that allow injected fluids and deep brines from the target formation or adjacent units to migrate upward into shallow drinking water aquifers. This study presents Sr isotope and geochemical data from a well-constrained site in Greene County, Pennsylvania, in which samples were collected before and after hydraulic fracturing of the Middle Devonian Marcellus Shale. Results spanning a 15-month period indicated no significant migration of Marcellus-derived fluids into Upper Devonian/Lower Mississippian units located 900-1200 m above the lateral Marcellus boreholes or into groundwater sampled at a spring near the site. Monitoring the Sr isotope ratio of water from legacy oil and gas wells or drinking water wells can provide a sensitive early warning of upward brine migration for many years after well stimulation.

  17. Molecular diffusion of stable water isotopes in polar firn as a proxy for past temperatures

    Science.gov (United States)

    Holme, Christian; Gkinis, Vasileios; Vinther, Bo M.

    2018-03-01

    Polar precipitation archived in ice caps contains information on past temperature conditions. Such information can be retrieved by measuring the water isotopic signals of δ18O and δD in ice cores. These signals have been attenuated during densification due to molecular diffusion in the firn column, where the magnitude of the diffusion is isotopologue specific and temperature dependent. By utilizing the differential diffusion signal, dual isotope measurements of δ18O and δD enable multiple temperature reconstruction techniques. This study assesses how well six different methods can be used to reconstruct past surface temperatures from the diffusion-based temperature proxies. Two of the methods are based on the single diffusion lengths of δ18O and δD , three of the methods employ the differential diffusion signal, while the last uses the ratio between the single diffusion lengths. All techniques are tested on synthetic data in order to evaluate their accuracy and precision. We perform a benchmark test to thirteen high resolution Holocene data sets from Greenland and Antarctica, which represent a broad range of mean annual surface temperatures and accumulation rates. Based on the benchmark test, we comment on the accuracy and precision of the methods. Both the benchmark test and the synthetic data test demonstrate that the most precise reconstructions are obtained when using the single isotope diffusion lengths, with precisions of approximately 1.0 °C . In the benchmark test, the single isotope diffusion lengths are also found to reconstruct consistent temperatures with a root-mean-square-deviation of 0.7 °C . The techniques employing the differential diffusion signals are more uncertain, where the most precise method has a precision of 1.9 °C . The diffusion length ratio method is the least precise with a precision of 13.7 °C . The absolute temperature estimates from this method are also shown to be highly sensitive to the choice of fractionation factor

  18. Highly stable copper oxide composite as an effective photocathode for water splitting via a facile electrochemical synthesis strategy

    KAUST Repository

    Zhang, Zhonghai

    2012-01-01

    Hydrogen generation through photoelectrochemical (PEC) water splitting using solar light as an energy resource is believed to be a clean and efficient way to overcome the global energy and environmental problems. Extensive research effort has been focused on n-type metal oxide semiconductors as photoanodes, whereas studies of p-type metal oxide semiconductors as photocathodes where hydrogen is generated are scarce. In this paper, highly efficient and stable copper oxide composite photocathode materials were successfully fabricated by a facile two-step electrochemical strategy, which consists of electrodeposition of a Cu film on an ITO glass substrate followed by anodization of the Cu film under a suitable current density and then calcination to form a Cu 2O/CuO composite. The synthesized Cu 2O/CuO composite was composed of a thin layer of Cu 2O with a thin film of CuO on its top as a protecting coating. The rational control of chemical composition and crystalline orientation of the composite materials was easily achieved by varying the electrochemical parameters, including electrodeposition potential and anodization current density, to achieve an enhanced PEC performance. The best photocathode material among all materials prepared was the Cu 2O/CuO composite with Cu 2O in (220) orientation, which showed a highly stable photocurrent of -1.54 mA cm -2 at a potential of 0 V vs reversible hydrogen electrode at a mild pH under illumination of AM 1.5G. This photocurrent density was more than 2 times that generated by the bare Cu 2O electrode (-0.65 mAcm -2) and the stability was considerably enhanced to 74.4% from 30.1% on the bare Cu 2O electrode. The results of this study showed that the top layer of CuO in the Cu 2O/CuO composite not only minimized the Cu 2O photocorrosion but also served as a recombination inhibitor for the photogenerated electrons and holes from Cu 2O, which collectively explained much enhanced stability and PEC activity of the Cu 2O/CuO composite

  19. Stable isotope tracers of water vapor sources in the Atacama Desert, Northern Chile: a pilot study on the Chajnantor Plateau

    Science.gov (United States)

    Samuels, K. E.; Galewsky, J.; Sharp, Z. D.; Rella, C.; Ward, D.

    2010-12-01

    Subtropical deserts form in response to the interaction of large-scale processes, including atmospheric circulation and oceanic currents, with local features like topography. The degree to which each of these factors controls desert formation and the anticipated impacts of variations in each as climate changes, however, are poorly understood. Stable isotope compositions of water vapor in desert air can help to distinguish between moisture sources and processes that control aridity. The Atacama Desert, located in northern Chile between latitudes 23S and 27S, provides a natural laboratory in which to test the degree to which water vapor isotopologues enable the distinction between processes that control humidity, including the Hadley Circulation, the cold Humboldt Current off the coast of Chile, and the orographic effect of the Andes, in this subtropical desert. Water vapor isotopologues and concentrations were measured in real time using a cavity-ringdown spectrometer deployed on the Chajnantor Plateau over a three-week period from mid-July early August 2010. The elevation of the Plateau, 5000 m amsl (~550 hPa), places it above the boundary layer, allowing the evaluation of the Rayleigh fractionation model from the coast inland. Values reported by the instrument were verified with air samples taken at the coast and the Plateau, which were analyzed on an MAT-252 mass spectrometer. Water vapor concentrations and δD values varied spatially and temporally. Water vapor concentrations on the Plateau ranged from 200 to 3664 ppmv with a mean value of 536 ppmv. In contrast, water vapor concentrations at the coast were approximately 10000 ppmv, and at Yungay, 60 km inland, water vapor concentrations ranged from 1300 to 2000 ppmv from morning to evening. δD values on the Plateau ranged from -526‰ to -100‰ with a mean value of 290‰ with enriched values correlated to periods with higher water vapor concentrations. There are no strong diurnal variations in water vapor

  20. Soil water stable isotopes reveal evaporation dynamics at the soil–plant–atmosphere interface of the critical zone

    Directory of Open Access Journals (Sweden)

    M. Sprenger

    2017-07-01

    , when using stable isotopes as tracers to assess plant water uptake patterns within the critical zone or applying them to calibrate tracer-aided hydrological models either at the plot to the catchment scale.

  1. Quantification of long-term wastewater fluxes at the surface water/groundwater-interface: an integrative model perspective using stable isotopes and acesulfame.

    Science.gov (United States)

    Engelhardt, I; Barth, J A C; Bol, R; Schulz, M; Ternes, T A; Schüth, C; van Geldern, R

    2014-01-01

    The suitability of acesulfame to trace wastewater-related surface water fluxes from streams into the hyporheic and riparian zones over long-term periods was investigated. The transport behavior of acesulfame was compared with the transport of water stable isotopes (δ(18)O or δ(2)H). A calibrated model based on a joint inversion of temperature, acesulfame, and piezometric pressure heads was employed in a model validation using data sets of acesulfame and water stable isotopes collected over 5months in a stream and groundwater. The spatial distribution of fresh water within the groundwater resulting from surface water infiltration was estimated by computing groundwater ages and compared with the predicted acesulfame plume obtained after 153day simulation time. Both, surface water ratios calculated with a mixing equation from water stable isotopes and simulated acesulfame mass fluxes, were investigated for their ability to estimate the contribution of wastewater-related surface water inflow within groundwater. The results of this study point to limitations for the application of acesulfame to trace surface water-groundwater interactions properly. Acesulfame completely missed the wastewater-related surface water volumes that still remained in the hyporheic zone under stream-gaining conditions. In contrast, under stream-losing conditions, which developed after periods of stagnating hydraulic exchange, acesulfame based predictions lead to an overestimation of the surface water volume of up to 25% in the riparian zone. If slow seepage velocities prevail a proportion of acesulfame might be stored in smaller pores, while when released under fast flowing water conditions it will travel further downstream with the groundwater flow direction. Therefore, under such conditions acesulfame can be a less-ideal tracer in the hyporheic and riparian zones and additional monitoring with other environmental tracers such as water stable isotopes is highly recommended. © 2013 Elsevier

  2. A multivariate analysis of intrinsic soil components influencing the mean-weight diameter of water-stable aggregates

    International Nuclear Information System (INIS)

    Mbagwu, J.S.C.; Chukwu, W.I.E.

    1994-06-01

    A knowledge of the soil properties influencing the water-stability of soil aggregates is needed for selecting those more easily-determined properties that would be useful in areas where lack of facilities makes its direct determination impossible. In this laboratory study we evaluated the main soil physical, chemical and mineralogical properties influencing the stability of macro aggregates of some Italian surface soils in water. The objective is to select a subset of soil properties which predict optimally, soil aggregate stability. The index of stability used is the mean weight diameter of water-stable aggregates whereas the method of evaluation is the principal component analysis (PCA). The range in coefficients of variation (CV) among the properties was least in the physical (12.0-61.0%), medium in the mineralogical (28.0-116.2%) and highest in the chemical (8.2-110.8%) properties. The wider the range in CV in each subset of properties, the greater the number of components extracted by the PCA. The component defining variables, i.e. those with the highest loadings on each component and therefore, provide the best relationship between the variables and aggregate stability, revealed the ratio of total sand/clay and plastic limit as the significant physical properties. The significant chemical properties are Al 2 O 3 , FeO, MgO and MnO which contribute positively to aggregate stability. Feldspar, quartz and muscovite are the significant mineralogical properties each of which is negatively related to aggregate stability. These soil components are useful for developing empirical models for estimating the stability of aggregates of these soils in water. (author). 38 refs, 7 tabs

  3. FLOW INJECTION ANALYSIS SYSTEM COUPLED WITH ICP-EOS FOR DETERMINATION OF SOME METALLIC ELEMENTS IN DRINKING WATER

    Directory of Open Access Journals (Sweden)

    Cristina Dinu

    2009-06-01

    Full Text Available The European Drinking Water Directive (98/83/EC, transposed in Romanian Legislation as Low 458/2002, amended by Low 311/2004, imposes the limit of concentration for metallic elements in water intended for human consumption. The toxic metals arsenic and selenium are among these elements and the limit value is 10 μg/L. In the paper there are presented the working conditions for determination of As and Se from drinking water using modern techniques based on the fl ow injection-hydride generation with the inductively coupled plasma atomic emission spectrometry (FIAS-ICP-EOS. The analyses were performed on Optima 5300 DV Perkin Elmer equipment with FIAS 400 Flow Injection System, Perkin Elmer type. For the hydride generation two types of solution were used: 10% (v/v HCl as a carrier solution and 0.2 % NaBH4 in 0.05%NaOH solution as a reducing agent [1]. The treatment step of the samples and standard solutions consisted in reducing with mixed solutions of KI and ascorbic acid in acidic condition (HCl for As and only with HCl and high temperature for Se [2,3]. The paper contains the characteristic parameters of the methods, such as: low detection limit, quantifi cation limit, repeatability, precision, recovery, which were evaluated using Certifi ed Reference Materials for each element.

  4. The choice between two designs for the safety-injection system of a pressurized-water reactor, using probabilistic methods

    International Nuclear Information System (INIS)

    Villemeur, Alain

    1982-01-01

    A probabilistic study has been carried out to compare two designs for the safety-injection circuit of a pressurized-water reactor. It appears that unavailability of the circuit after an accident involving loss of coolant decreases little when one moves from a 2-line to a 3-line system. These results are compared with the disadvantages arising from increased redundancy, and in particular the increased cost of the installations. The 2-line circuit appears the optimum one on the basis of cost and reliability criteria. It has been chosen for the 1300-MWe units [fr

  5. Anticipated transient without scram analysis of the simplified boiling water reactor following main steam isolation valve closure with boron injection

    International Nuclear Information System (INIS)

    Khan, H.J.; Cheng, H.S.; Rohatgi, U.S.

    1996-01-01

    The simplified boiling water reactor (SBWR) operating in natural circulation is designed with many passive safety features. An anticipated transient without scram (ATWS) initiated by inadvertent closure of the main steam isolation valve (MSIV) in an SBWR has been analyzed using the RAMONA-4B code of Brookhaven National Laboratory. This analysis demonstrates the predicted performance of the SBWR during an MSIV closure ATWS, followed by shutdown of the reactor through injection of boron into the reactor core from the standby liquid control system

  6. Effect of injection water quality on permeability of productive sands in Shaimsk group of oil fields

    Energy Technology Data Exchange (ETDEWEB)

    Andreeva, N I; Ivanov, V N; Lazarev, V N; Maksimov, V P

    1966-01-01

    Water from the Kond River is used to flood Shaimsk oil fields. Effect of raw and filtered waters on permeability of Shaimsk cores was experimentally determined. The raw river water contained 26 mg/liter of suspended solids, 10.7 mg/liter of total iron, 4.3 mg/liter of suspended iron oxide, and a pH of 6.4. The filtered river water was free of suspended solids and had a pH of 6.2. It was found that both raw and filtered water decreased core permeability. The unfiltered water decreased permeability 2 to 7 times more than the filtered water. Also, the decrease in permeability occurs much more slowly with the filtered than the unfiltered water. The effect of water on core permeability is essentially irreversible. Efforts to restore core permeability by reversing flow direction were not successful. Among the reasons for the permeability decrease were hydration and swelling of clays and evolution of gases from water in the cores. (10 refs.)

  7. A Boiling-Water-Stable, Tunable White-Emitting Metal-Organic Framework from Soft-Imprint Synthesis.

    Science.gov (United States)

    He, Jun; Huang, Jian; He, Yonghe; Cao, Peng; Zeller, Matthias; Hunter, Allen D; Xu, Zhengtao

    2016-01-26

    A new avenue for making porous frameworks has been developed by borrowing an idea from molecularly imprinted polymers (MIPs). In lieu of the small molecules commonly used as templates in MIPs, soft metal components, such as CuI, are used to orient the molecular linker and to leverage the formation of the network. Specifically, a linear dicarboxylate linker with thioether side groups reacted simultaneously with Ln(3+) ions and CuI, leading to a bimetallic net featuring strong, chemically hard Eu(3+) -carboxylate links, as well as soft, thioether-bound Cu2 I2 clusters. The CuI block imparts water stability to the host; with the tunable luminescence from the lanthanide ions, this creates the first white-emitting MOF that is stable in boiling water. The Cu2 I2 block also readily reacts with H2 S, and enables sensitive colorimetric detection while the host net remains intact. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Effect of water and gluten on physico-chemical properties and stability of ready to eat shelf-stable pasta.

    Science.gov (United States)

    Diantom, Agoura; Carini, Eleonora; Curti, Elena; Cassotta, Fabrizio; D'Alessandro, Alessandro; Vittadini, Elena

    2016-03-15

    A multi-analytical and multi-dimensional approach was used to investigate the effect of moisture and gluten on physico-chemical properties of shelf-stable ready to eat (RTE) pasta. Moisture and frozen water contents were not affected by formulation nor storage time. Hardness and retrograded amylopectin significantly increased during storage in all samples, more markedly in pasta with the lowest moisture content. Higher amounts of water and gluten reduced pasta hardening and contributed to control RTE pasta quality. (1)H FID became steeper in all samples during storage, but no effect of high moisture and gluten levels was observed on the mobility of these protons. Three proton T2 populations were observed (population C, population D and population E). Population C and D were not resolved during all storage. (1)H T2 relaxation time of the most abundant population (population E) shifted to shorter times and the amount of protons increased during storage, more importantly in the samples with lower moisture and gluten content. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Stable carbon isotope ratios and intrinsic water-use efficiency of Miocene fossil leaves compared to modern congeners

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, J.D.; Zhang, J.; Rember, W.C.; Jennings, D.; Larson, P. (Univ. of Idaho, Moscow, ID (United States))

    1994-06-01

    Miocene fossil leaves of forest trees were extracted from the Clarkia, Idaho fossil beds and their stable carbon isotope ratios were analyzed. Fossils had higher lignin concentrations and lower cellulose concentrations that modern leaves due to diagenesis and the HF used to extract the fossils. Therefore, [delta][sup 13]C of extracted fossil lignin was compared to that of modern lignin. Fossil lignin [delta][sup 13]C was significantly different from that of congeneric modern leaves (paired t-test, P<0.0001), but was 1.9% less negative. Gymnosperms (Metasequoia, Taxodium) were less negative than angiosperms (e.g., Magnolia, Quercus, Acer, Persea), but no difference between evergreen and deciduous species was detected. Using published estimates of the concentration and [delta][sup 13]C of atmospheric CO[sub 2] during the Miocene was estimated the CO[sub 2] partial pressure gradient across the stomata (intrinsic water-use efficiency). Intrinsic water-use efficiency was at least 70% higher during this past [open quotes]greenhouse[close quotes] period than at present.

  10. Stable isotope geochemical study of Pamukkale travertines: New evidences of low-temperature non-equilibrium calcite-water fractionation

    Science.gov (United States)

    Kele, Sándor; Özkul, Mehmet; Fórizs, István; Gökgöz, Ali; Baykara, Mehmet Oruç; Alçiçek, Mehmet Cihat; Németh, Tibor

    2011-06-01

    In this paper we present the first detailed geochemical study of the world-famous actively forming Pamukkale and Karahayit travertines (Denizli Basin, SW-Turkey) and associated thermal waters. Sampling was performed along downstream sections through different depositional environments (vent, artificial channel and lake, terrace-pools and cascades of proximal slope, marshy environment of distal slope). δ 13C travertine values show significant increase (from + 6.1‰ to + 11.7‰ PDB) with increasing distance from the spring orifice, whereas the δ 18O travertine values show only slight increase downstream (from - 10.7‰ to - 9.1‰ PDB). Mainly the CO 2 outgassing caused the positive downstream shift (~ 6‰) in the δ 13C travertine values. The high δ 13C values of Pamukkale travertines located closest to the spring orifice (not affected by secondary processes) suggest the contribution of CO 2 liberated by thermometamorphic decarbonation besides magmatic sources. Based on the gradual downstream increase of the concentration of the conservative Na +, K +, Cl -, evaporation was estimated to be 2-5%, which coincides with the moderate effect of evaporation on the water isotope composition. Stable isotopic compositions of the Pamukkale thermal water springs show of meteoric origin, and indicate a Local Meteoric Water Line of Denizli Basin to be between the Global Meteoric Water Line (Craig, 1961) and Western Anatolian Meteoric Water Line (Şimşek, 2003). Detailed evaluation of several major and trace element contents measured in the water and in the precipitated travertine along the Pamukkale MM section revealed which elements are precipitated in the carbonate or concentrated in the detrital minerals. Former studies on the Hungarian Egerszalók travertine (Kele et al., 2008a, b, 2009) had shown that the isotopic equilibrium is rarely maintained under natural conditions during calcite precipitation in the temperature range between 41 and 67 °C. In this paper

  11. Pore Pressure and Field stress variation from Salt Water Injection; A case Study from Beaver Lodge Field in Williston Basin

    Science.gov (United States)

    Mohammed, R. A.; Khatibi, S.

    2017-12-01

    One of the major concerns in producing from oil and gas reservoirs in North American Basins is the disposal of high salinity salt water. It is a misconception that Hydro frack triggers Earthquakes, but due to the high salinity and density of water being pumped to the formation that has pore space of the rock already filled, which is not the case in Hydro-frack or Enhanced Oil Recovery in which fracturing fluid is pumped into empty pore space of rocks in depleted reservoirs. A review on the Bakken history showed that the concerns related to induce seismicity has increased over time due to variations in Pore pressure and In-situ stress that have shown steep changes in the region over the time. In this study, we focused on Pore pressure and field Stress variations in lower Cretaceous Inyan Kara and Mississippian Devonian Bakken, Inyan Kara is the major source for class-II salt-water disposal in the basin. Salt-water disposal is the major cause for induced seismicity. A full field study was done on Beaver Lodge Field, which has many salt-water disposal wells Adjacent to Oil and Gas Wells. We analyzed formation properties, stresses, pore-pressure, and fracture gradient profile in the field and. The constructed Mechanical Earth Model (MEM) revealed changes in pore pressure and stresses over time due to saltwater injection. Well drilled in the past were compared to recently drilled wells, which showed much stress variations. Safe mud weight Window of wells near proximity of injection wells was examined which showed many cases of wellbore instabilities. Results of this study will have tremendous impact in studying environmental issues and the future drilling and Fracking operations.

  12. Integrated Assessment Of Groundwater Recharge In The North Kelantan River Basin Using Environmental Water Stable Isotopes, Tritium And Chloride Data

    International Nuclear Information System (INIS)

    Wan Zakaria Wan Muhamad Tahir; Nur Hayati Hussin; Ismail Yusof; Kamaruzaman Mamat; Johari Abdul Latif; Rohaimah Demanah

    2014-01-01

    Estimation and understanding of groundwater recharge mechanism and capacity of aquifer are essential issues in water resources investigation. An integrated study of environmental chloride content in the unsaturated zone using chloride mass balance method (CMB) and isotopic analyses of deuterium, oxygen-18, and tritium values range in the alluvial channel aquifer profiles (quaternary sediments) of the North Kelantan River basin has been carried out in order to estimate and understand groundwater recharge processes. However, the rate of aquifer recharge is one of the most difficult factors to measure in the evaluation of ground water resources. Estimation of recharge, by whatever method, is normally subject to large uncertainties and errors. In this paper, changes in stable isotopic signatures in different seasons and tritium analysis of the sampled groundwater observed at different depth in the aquifer system were evaluated. Stable isotope data are slightly below the local meteoric water line (LMWL) indicating that there is some isotopic enrichment due to direct evaporation through the soil surface which is exposed prior or during the recharging process. The overall data on water isotopic signatures from boreholes and production wells (shallow and relatively deep aquifer system) are spread over a fairly small range but somewhat distinct compared to river water isotopic compositions. Such a narrow variation in isotopic signatures of the sampled groundwaters may suggest that all groundwater samples originated from the same area of direct recharge predominantly from rainfall and nearby rivers. Environmental tritium data measured in groundwater at different depths and locations together with a medium-term of limited monthly rainfall collections were used to investigate the groundwater age distributions (residence times). The existence of groundwater in the aquifer system (sampled wells) is predominantly designated as modern (young) water that has undergone recharged

  13. Development of form stable Poly(methyl methacrylate) (PMMA) coated thermal phase change material for solar water heater applications

    Science.gov (United States)

    Munusamy, Y.; Shanmugam, S.; Shi-Ying, Kee

    2018-04-01

    Phase change material (PCM) is one of the most popular and widely used thermal energy storage material in solar water heater because it able to absorb and release a large amount of latent heat during a phase change process over a narrow temperature range. However the practical application of PCM is limited by two major issues; 1) leakage which leads to material loss and corrosion of tank and 2) large volume change during phase change process which cause pressure build up in the tank. In this work, form-stable PCM was prepared by coating myristic acid with Poly(methyl methacrylate) (PMMA) to prevent leakage of PCM. PMMA was mixed with different weight percentage (0.1, 0.2, 0.3, 0.4 and 0.5 wt%) of dicumyl peroxide (DCP). The purpose of adding DCP to PMMA is to crosslink the polymer and to increase the mechanical strength of PMMA to hold the myristic acid content inside the coating during the phase change process. Leakage test results showed that PMMA mixed with 0.1% DCP exhibit 0% leakage. This result is further supported by Field Emission Scanning Electron Microscopy (FESEM) images and Fourier transform infrared spectroscopy (FTIR) analysis results, where a compact and uniform coating without cracks were formed for PCM coated with PMMA with 0.1% DCP. Differential scanning calorimetry (DSC) results shows that the melting point of form-stable PCM is 55°C, freezing point is 50°C, the latent heat of melting and freezing is 67.59 J/g.

  14. Large-scale spatial and interspecies differences in trace elements and stable isotopes in marine wild fish from Chinese waters

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei [Key Laboratory of Marine Bio-resources Sustainable Utilization, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Wang, Wen-Xiong, E-mail: wwang@ust.hk [Division of Life Science, HKUST, Clear Water Bay, Kowloon (Hong Kong)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer A large-scale study on trace element levels in marine wild fish from Chinese waters. Black-Right-Pointing-Pointer Spatial variation found for Al, As, Cd, Cr, Fe, Ni, Pb, but not for Ag, Cu, Mo, Se and Zn. Black-Right-Pointing-Pointer The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb. Black-Right-Pointing-Pointer No biomagnification occurred for any of the trace elements studied in marine fish. Black-Right-Pointing-Pointer No obvious health risk from the intake of trace elements through fish consumption. - Abstract: We conducted a large scale investigation of twelve trace element levels and stable isotopes ({delta}{sup 13}C and {delta}{sup 15}N) in twenty-nine marine wild fish species collected from Chinese coastal waters. Trace element levels varied significantly with species. Clear spatial variations were found for Al, As, Cd, Cr, Fe, Ni, and Pb, whereas Ag, Cu, Mo, Se and Zn did not show much spatial variation. The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb, whereas the most southern waters (Haikou) contained the lowest concentrations of Al, Fe, and Pb. There was no correlation between log-transformed trace elements concentrations and {delta}{sup 15}N values or {delta}{sup 13}C values, indicating no biomagnification among these trace elements. The calculated hazard quotients (HQ) of 10 elements were less than 1, thus there was no obvious health risk from the intake of trace elements through marine wild fish consumption.

  15. Stable isotopes and mercury in a model estuarine fish: Multibasin comparisons with water quality, community structure, and available prey base

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Douglas H., E-mail: Doug.Adams@MyFWC.com; Paperno, Richard

    2012-01-01

    Stable-isotope ratios ({delta}{sup 13}C and {delta}{sup 15}N) and mercury in a model predator, and associated prey community assessments were used to make inferences regarding food web relationships and how these relationships are influenced by habitat variability and anthropogenic factors. Although interconnected, the three major basins of the Indian River Lagoon system on the Atlantic coast of Florida comprise noticeably different available habitat types with spatially distinct faunal communities and available prey for spotted seatrout, Cynoscion nebulosus, a model predatory fish species. Water quality, degree of urbanization, human population density, and levels of nitrogen enrichment clearly differ between these representative estuarine basins. The differences can influence feeding ecology and therefore result in different mercury concentrations and different stable-isotope signatures of spotted seatrout between basins. Mercury concentrations in spotted seatrout were greatest in Mosquito Lagoon (ML) and least in the Indian River Lagoon proper (IRL), although concentrations were low for all basins. Spotted seatrout from IRL were carbon-depleted and nitrogen-enriched compared with those from the other basins; this suggests either that the fish's primary source of carbon in IRL is an algae- or phytoplankton-based food web or that the pathway through the food web is shorter there. The {delta}{sup 15}N values of IRL spotted seatrout were greater than those in the Banana River Lagoon or ML, suggesting slightly different trophic positioning of fish in these basins. The greater {delta}{sup 15}N values in IRL spotted seatrout may also reflect the greater human population density and resultant anthropogenic inputs (e.g., observed higher total nitrogen levels) in IRL compared with the other more pristine basins examined. Understanding species' responses to broad-scale habitat heterogeneity in estuaries and knowing basin-specific differences in stable isotopes

  16. Tomographic Imaging of Water Injection and Withdrawal in PEMFC Gas Diffusion Layers

    Energy Technology Data Exchange (ETDEWEB)

    McGill U; Gostick, J. T.; Gunterman, H. P.; Weber, A. Z.; Newman, J. S.; Kienitz, B. L.; MacDowell, A. A.

    2010-06-25

    X-ray computed tomography was used to visualize the water configurations inside gas diffusion layers for various applied capillary pressures, corresponding to both water invasion and withdrawal. A specialized sample holder was developed to allow capillary pressure control on the small-scale samples required. Tests were performed on GDL specimens with and without hydrophobic treatments.

  17. Potentials of cooled EGR and water injection for knock resistance and fuel consumption improvements of gasoline engines

    International Nuclear Information System (INIS)

    Bozza, Fabio; De Bellis, Vincenzo; Teodosio, Luigi

    2016-01-01

    Highlights: • 1D simulation of a turbocharged VVA engine under knock limited operation. • Description of turbulence, combustion and knock by phenomenological models. • Comparison of EGR and ported water injection at high load for knock mitigation and fuel economy. • Virtual calibration of engine control parameters by a 1D model. - Abstract: It is well known that the downsizing philosophy allows the improvement of the brake specific fuel consumption (BSFC) at part load operation for spark ignition (SI) engines. On the other hand, the BSFC is penalized at high load because of the knock occurrence and of further limitations on the turbine inlet temperature (TIT). Knock control forces the adoption of a late combustion phasing, causing a deterioration of the thermodynamic efficiency, while the TIT control requires the enrichment of the air-to-fuel ratio (A/F), with additional BSFC drawbacks. In this work, two promising techniques are investigated by a 1D approach with the aim of improving the fuel economy of a turbocharged SI engine at full load knock-limited operation. The first technique is the recirculation of low-pressure cooled exhaust gas (EGR), while the second is the injection of liquid water at the intake ports. Proper “in-house developed” sub-models are used to describe the turbulence, combustion and knock phenomena. The effects of the above techniques are studied in six operating points at full load and different speeds for various A/F levels and inert content, by varying the EGR rate and water-to-fuel ratio. The presented results highlight that both the solutions involve significant BSFC improvements, especially in the operating conditions at medium engine speeds. In fact, the introduction of inert gas in the cylinder contributes to reduce the knock tendency, resulting in the possibility to advance the combustion phasing and reduce, or even avoid, the mixture over-fuelling. The heat subtracted by the water evaporation enhances the above effects

  18. Temporal evolution of stable water isotopologues in cloud droplets in a hill cap cloud in central Europe (HCCT-2010

    Directory of Open Access Journals (Sweden)

    J. K. Spiegel

    2012-12-01

    humidity and temperature at the moisture source region or both. This study illustrates the sensitivity of stable isotope composition of cloud water to changes in large scale air mass properties and regional recycling of moisture.

  19. On the cross-sensitivity between water vapor mixing ratio and stable isotope measurements of in-situ analyzers

    KAUST Repository

    Parkes, Stephen

    2015-04-01

    In recent years there has been an increasing amount of water vapor stable isotope data collected using in-situ instrumentation. A number of papers have characterized the performance of these in-situ analyzers and suggested methods for calibrating raw measurements. The cross-sensitivity of the isotopic measurements on the mixing ratio has been shown to be a major uncertainty and a variety of techniques have been suggested to characterize this inaccuracy. However, most of these are based on relating isotopic ratios to water vapor mixing ratios from in-situ analyzers when the mixing ratio is varied and the isotopic composition kept constant. An additional correction for the span of the isotopic ratio scale is then applied by measuring different isotopic standards. Here we argue that the water vapor cross-sensitivity arises from different instrument responses (span and offset) of the parent H2O isotope and the heavier isotopes, rather than spectral overlap that could cause a true variation in the isotopic ratio with mixing ratio. This is especially relevant for commercial laser optical instruments where absorption lines are well resolved. Thus, the cross-sensitivity determined using more conventional techniques is dependent on the isotopic ratio of the standard used for the characterization, although errors are expected to be small. Consequently, the cross-sensitivity should be determined by characterizing the span and zero offset of each isotope mixing ratio. In fact, this technique makes the span correction for the isotopic ratio redundant. In this work we model the impact of changes in the span and offset of the heavy and light isotopes and illustrate the impact on the cross-sensitivity of the isotopic ratios on water vapor. This clearly shows the importance of determining the zero offset for the two isotopes. The cross-sensitivity of the isotopic ratios on water vapor is then characterized by determining the instrument response for the individual isotopes for a

  20. Temporal evolution of stable water isotopologues in cloud droplets in a hill cap cloud in central Europe (HCCT-2010)

    Science.gov (United States)

    Spiegel, J.K.; Aemisegger, F.; Scholl, M.; Wienhold, F.G.; Collett, J.L.; Lee, T.; van Pinxteren, D.; Mertes, S.; Tilgner, A.; Herrmann, H.; Werner, Roland A.; Buchmann, N.; Eugster, W.

    2012-01-01

    In this work, we present the first study resolving the temporal evolution of δ2H and δ18O values in cloud droplets during 13 different cloud events. The cloud events were probed on a 937 m high mountain chain in Germany in the framework of the Hill Cap Cloud Thuringia 2010 campaign (HCCT-2010) in September and October 2010. The δ values of cloud droplets ranged from −77‰ to −15‰ (δ2H) and from −12.1‰ to −3.9‰ (δ18O) over the whole campaign. The cloud water line of the measured δ values was δ2H=7.8×δ18O+13×10−3, which is of similar slope, but with higher deuterium excess than other Central European Meteoric Water Lines. Decreasing δ values in the course of the campaign agree with seasonal trends observed in rain in central Europe. The deuterium excess was higher in clouds developing after recent precipitation revealing episodes of regional moisture recycling. The variations in δ values during one cloud event could either result from changes in meteorological conditions during condensation or from variations in the δ values of the water vapor feeding the cloud. To test which of both aspects dominated during the investigated cloud events, we modeled the variation in δ values in cloud water using a closed box model. We could show that the variation in δ values of two cloud events was mainly due to changes in local temperature conditions. For the other eleven cloud events, the variation was most likely caused by changes in the isotopic composition of the advected and entrained vapor. Frontal passages during two of the latter cloud events led to the strongest temporal changes in both δ2H (≈ 6‰ per hour) and δ18O (≈ 0.6‰ per hour). Moreover, a detailed trajectory analysis for the two longest cloud events revealed that variations in the entrained vapor were most likely related to rain out or changes in relative humidity and temperature at the moisture source region or both. This study illustrates the sensitivity of stable isotope

  1. On the cross-sensitivity between water vapor mixing ratio and stable isotope measurements of in-situ analyzers

    KAUST Repository

    Parkes, Stephen; Wang,  Lixin; McCabe, Matthew

    2015-01-01

    In recent years there has been an increasing amount of water vapor stable isotope data collected using in-situ instrumentation. A number of papers have characterized the performance of these in-situ analyzers and suggested methods for calibrating raw measurements. The cross-sensitivity of the isotopic measurements on the mixing ratio has been shown to be a major uncertainty and a variety of techniques have been suggested to characterize this inaccuracy. However, most of these are based on relating isotopic ratios to water vapor mixing ratios from in-situ analyzers when the mixing ratio is varied and the isotopic composition kept constant. An additional correction for the span of the isotopic ratio scale is then applied by measuring different isotopic standards. Here we argue that the water vapor cross-sensitivity arises from different instrument responses (span and offset) of the parent H2O isotope and the heavier isotopes, rather than spectral overlap that could cause a true variation in the isotopic ratio with mixing ratio. This is especially relevant for commercial laser optical instruments where absorption lines are well resolved. Thus, the cross-sensitivity determined using more conventional techniques is dependent on the isotopic ratio of the standard used for the characterization, although errors are expected to be small. Consequently, the cross-sensitivity should be determined by characterizing the span and zero offset of each isotope mixing ratio. In fact, this technique makes the span correction for the isotopic ratio redundant. In this work we model the impact of changes in the span and offset of the heavy and light isotopes and illustrate the impact on the cross-sensitivity of the isotopic ratios on water vapor. This clearly shows the importance of determining the zero offset for the two isotopes. The cross-sensitivity of the isotopic ratios on water vapor is then characterized by determining the instrument response for the individual isotopes for a

  2. The O and H stable isotope composition of freshwaters in the British Isles. 2. Surface waters and groundwater

    Directory of Open Access Journals (Sweden)

    W. G. Darling

    2003-01-01

    Full Text Available The utility of stable isotopes as tracers of the water molecule has a long pedigree. The study reported here is part of an attempt to establish a comprehensive isotopic 'baseline' for the British Isles as background data for a range of applications. Part 1 of this study (Darling and Talbot, 2003 considered the isotopic composition of rainfall in Britain and Ireland. The present paper is concerned with the composition of surface waters and groundwater. In isotopic terms, surface waters (other than some upland streams are poorly characterised in the British Isles; their potential variability has yet to be widely used as an aid in hydrological research. In what may be the first study of a major British river, a monthly isotopic record of the upper River Thames during 1998 was obtained. This shows high damping of the isotopic variation compared to that in rainfall over most of the year, though significant fluctuations were seen for the autumn months. Smaller rivers such as the Stour and Darent show a more subdued response to the balance between runoff and baseflow. The relationship between the isotopic composition of rainfall and groundwater is also considered. From a limited database, it appears that whereas Chalk groundwater is a representative mixture of weighted average annual rainfall, for Triassic sandstone groundwater there is a seasonal selection of rainfall biased towards isotopically-depleted winter recharge. This may be primarily the result of physical differences between the infiltration characteristics of rock types, though other factors (vegetation, glacial history could be involved. In the main, however, groundwaters appear to be representative of bulk rainfall within an error band of 0.5‰ δ18O. Contour maps of the δ18O and δ2H content of recent groundwaters in the British Isles show a fundamental SW-NE depletion effect modified by topography. The range of measured values, while much smaller than those for rainfall, still covers

  3. A highly efficient six-stroke internal combustion engine cycle with water injection for in-cylinder exhaust heat recovery

    International Nuclear Information System (INIS)

    Conklin, James C.; Szybist, James P.

    2010-01-01

    A concept adding two strokes to the Otto or Diesel engine cycle to increase fuel efficiency is presented here. It can be thought of as a four-stroke Otto or Diesel cycle followed by a two-stroke heat recovery steam cycle. A partial exhaust event coupled with water injection adds an additional power stroke. Waste heat from two sources is effectively converted into usable work: engine coolant and exhaust gas. An ideal thermodynamics model of the exhaust gas compression, water injection and expansion was used to investigate this modification. By changing the exhaust valve closing timing during the exhaust stroke, the optimum amount of exhaust can be recompressed, maximizing the net mean effective pressure of the steam expansion stroke (MEP steam ). The valve closing timing for maximum MEP steam is limited by either 1 bar or the dew point temperature of the expansion gas/moisture mixture when the exhaust valve opens. The range of MEP steam calculated for the geometry of a conventional gasoline engine and is from 0.75 to 2.5 bars. Typical combustion mean effective pressures (MEP combustion ) of naturally aspirated gasoline engines are up to 10 bar, thus this concept has the potential to significantly increase the engine efficiency and fuel economy.

  4. Pilot Experimental Works on Injection of Hot Water with Surfactants into Bobrikovian Deposits of Berket-Klyuchevsky Field

    Directory of Open Access Journals (Sweden)

    R.N. Khusnutdinov

    2017-03-01

    Full Text Available The problem of developing and introducing new methods of enhancing oil recovery is especially important for heavy oil fields, the share of which in the structure of reserves is steadily growing. Conventional methods of oil recovery and stimulation of well productivity applied on heavy oil fields are often ineffective, in this regard, the increase in the efficiency of geological and technical measures at such objects is becoming increasingly dependent on the concentration of intensifying factors of influence on the reservoir and the proper choice of technology in accordance with geological and geophysical conditions. The authors have developed and introduced into production the resource-saving technology of complex stimulation on the productive layer, which includes a combination of physical, chemical, thermal and hydrodynamic factors of stimulation. A rational combination of these factors made it possible to increase the efficiency of developing a heavy oil deposit – to stabilize the decline and increase oil production. Technologically, the implemented development method consists in injecting hot water into the injection wells with a calculated content of surfactants. Associated gas of this section of the field, previously burned on the flare, is used as fuel for heating water. The introduction of the technology allowed to completely solve the problem of utilization of associated gas at the site: the flare was extinguished, as a result of which the emissions and technogenic load on the environment were also reduced.

  5. Stable oxygen isotope analysis reveal vegetation influence on soil water movement and ecosystem water fluxes in a semi-arid oak woodland

    Science.gov (United States)

    Piayda, Arndt; Dubbert, Maren; Werner, Christiane; Cuntz, Matthias

    2015-04-01

    Mechanistically disentangling the role and function of vegetation within the hydrological cycle is one of the key questions in the interdisciplinary field of ecohydrology. The presence of vegetation can have various impacts on soil water relations: transpiration of active vegetation causes great water losses, rainfall is intercepted, soil evaporation can be reduced and infiltration, hydraulic redistribution and translatory flow might be altered. In drylands, covering around 40% of the global land surface, the carbon cycle is closely coupled to water availability due to (seasonal) droughts. Specifically savannah type ecosystems, which cover large areas worldwide, are, due to their bi-layered structure, very suitable to study the effects of distinct vegetation types on the ecosystem water cycle. Oxygen isotope signatures (δ18O) have been used to partition ecosystem evapotranspiration (ET ) because of the distinct isotopic compositions of water transpired by leaves relative to soil evaporated vapor. Recent developments in laser spectroscopy enable measurements of δ18O in the vapor phase with high temporal resolution in the field and bear a novel opportunity to trace water movement within the ecosystem. In the present study, the effects of distinct vegetation layers (i.e. trees and herbaceous vegetation) on soil water infiltration and redistribution as well as ecosystem water fluxes in a Mediterranean cork-oak woodland are disentangled. An irrigation experiment was carried out using δ18O labeled water to quantify the distinct effects of trees and herbaceous vegetation on 1) infiltration and redistribution of water in the soil profile and 2) to disentangle the effects of tree cover on the contribution of unproductive soil evaporation and understory transpiration to total ET . First results proof that stable δ18O isotopes measured onsite with laser spectroscopy is a valuable tool to trace water movement in the soil showing a much higher sensitivity than common TDR

  6. A new unconditionally stable and consistent quasi-analytical in-stream water quality solution scheme for CSTR-based water quality simulators

    Science.gov (United States)

    Woldegiorgis, Befekadu Taddesse; van Griensven, Ann; Pereira, Fernando; Bauwens, Willy

    2017-06-01

    Most common numerical solutions used in CSTR-based in-stream water quality simulators are susceptible to instabilities and/or solution inconsistencies. Usually, they cope with instability problems by adopting computationally expensive small time steps. However, some simulators use fixed computation time steps and hence do not have the flexibility to do so. This paper presents a novel quasi-analytical solution for CSTR-based water quality simulators of an unsteady system. The robustness of the new method is compared with the commonly used fourth-order Runge-Kutta methods, the Euler method and three versions of the SWAT model (SWAT2012, SWAT-TCEQ, and ESWAT). The performance of each method is tested for different hypothetical experiments. Besides the hypothetical data, a real case study is used for comparison. The growth factors we derived as stability measures for the different methods and the R-factor—considered as a consistency measure—turned out to be very useful for determining the most robust method. The new method outperformed all the numerical methods used in the hypothetical comparisons. The application for the Zenne River (Belgium) shows that the new method provides stable and consistent BOD simulations whereas the SWAT2012 model is shown to be unstable for the standard daily computation time step. The new method unconditionally simulates robust solutions. Therefore, it is a reliable scheme for CSTR-based water quality simulators that use first-order reaction formulations.

  7. Study on Mixed Solvency Concept in Formulation Development of Aqueous Injection of Poorly Water Soluble Drug

    Directory of Open Access Journals (Sweden)

    Shailendra Singh Solanki

    2013-01-01

    Full Text Available In the present investigation, mixed-solvency approach has been applied for the enhancement of aqueous solubility of a poorly water- soluble drug, zaltoprofen (selected as a model drug, by making blends (keeping total concentrations 40% w/v, constant of selected water-soluble substances from among the hydrotropes (urea, sodium benzoate, sodium citrate, nicotinamide; water-soluble solids (PEG-4000, PEG-6000; and co-solvents (propylene glycol, glycerine, PEG-200, PEG-400, PEG-600. Aqueous solubility of drug in case of selected blends (12 blends ranged from 9.091 ± 0.011 mg/ml–43.055 ± 0.14 mg/ml (as compared to the solubility in distilled water 0.072 ± 0.012 mg/ml. The enhancement in the solubility of drug in a mixed solvent containing 10% sodium citrate, 5% sodium benzoate and 25 % S cosolvent (25% S cosolvent contains PEG200, PEG 400, PEG600, Glycerine and Propylene glycol was more than 600 fold. This proved a synergistic enhancement in solubility of a poorly water-soluble drug due to mixed cosolvent effect. Each solubilized product was characterized by ultraviolet and infrared techniques. Various properties of solution such as pH, viscosity, specific gravity and surface tension were studied. The developed formulation was studied for physical and chemical stability. This mixed solvency shall prove definitely a boon for pharmaceutical industries for the development of dosage form of poorly water soluble drugs.

  8. Managing Injected Water Composition To Improve Oil Recovery: A Case Study of North Sea Chalk Reservoirs

    DEFF Research Database (Denmark)

    Zahid, Adeel; Shapiro, Alexander; Stenby, Erling Halfdan

    2012-01-01

    of the temperature dependence of the oil recovery indicated that the interaction of the ions contained in brine with the rock cannot be the only determining mechanism of enhanced recovery. We observed no substitution of Ca2+ ions with Mg2+ ions at high temperatures for both rocks. Not only the injection brine......In recent years, many core displacement experiments of oil by seawater performed on chalk rock samples have reported SO42–, Ca2+, and Mg2+ as potential determining ions for improving oil recovery. Most of these studies were carried out with outcrop chalk core plugs. The objective of this study...... is to investigate the potential of the advanced waterflooding process by carrying out experiments with reservoir chalk samples. The study results in a better understanding of the mechanisms involved in increasing the oil recovery with potential determining ions. We carried out waterflooding instead of spontaneous...

  9. Seasonality of stable isotope composition of atmospheric water input at the southern slopes of Mt. Kilimanjaro, Tanzania

    Science.gov (United States)

    Otte, Insa; Detsch, Florian; Gutlein, Adrian; Scholl, Martha A.; Kiese, Ralf; Appelhans, Tim; Nauss, Thomas

    2017-01-01

    To understand the moisture regime at the southern slopes of Mt. Kilimanjaro, we analysed the isotopic variability of oxygen (δ18O) and hydrogen (δD) of rainfall, throughfall, and fog from a total of 2,140 samples collected weekly over 2 years at 9 study sites along an elevation transect ranging from 950 to 3,880 m above sea level. Precipitation in the Kilimanjaro tropical rainforests consists of a combination of rainfall, throughfall, and fog. We defined local meteoric water lines for all 3 precipitation types individually and the overall precipitation, δDprec = 7.45 (±0.05) × δ18Oprec + 13.61 (±0.20), n = 2,140, R2 = .91, p research site. We found an altitude effect of δ18Orain = −0.11‰ × 100 m−1, which varied according to precipitation type and season. The relatively weak isotope or altitude gradient may reveal 2 different moisture sources in the research area: (a) local moisture recycling and (b) regional moisture sources. Generally, the seasonality of δ18Orain values follows the bimodal rainfall distribution under the influences of south- and north-easterly trade winds. These seasonal patterns of isotopic composition were linked to different regional moisture sources by analysing Hybrid Single Particle Lagrangian Integrated Trajectory backward trajectories. Seasonality of dexcess values revealed evidence of enhanced moisture recycling after the onset of the rainy seasons. This comprehensive dataset is essential for further research using stable isotopes as a hydrological tracer of sources of precipitation that contribute to water resources of the Kilimanjaro region.

  10. Enhanced oil recovery by nitrogen and carbon dioxide injection followed by low salinity water flooding for tight carbonate reservoir: experimental approach

    Science.gov (United States)

    Georges Lwisa, Essa; Abdulkhalek, Ashrakat R.

    2018-03-01

    Enhanced Oil Recovery techniques are one of the top priorities of technology development in petroleum industries nowadays due to the increase in demand for oil and gas which cannot be equalized by the primary production or secondary production methods. The main function of EOR process is to displace oil to the production wells by the injection of different fluids to supplement the natural energy present in the reservoir. Moreover, these injecting fluids can also help in the alterations of the properties of the reservoir like lowering the IFTs, wettability alteration, a change in pH value, emulsion formation, clay migration and oil viscosity reduction. The objective of this experiment is to investigate the residual oil recovery by combining the effects of gas injection followed by low salinity water injection for low permeability reservoirs. This is done by a series of flooding tests on selected tight carbonate core samples taken from Zakuum oil field in Abu Dhabi by using firstly low salinity water as the base case and nitrogen & CO2injection followed by low salinity water flooding at reservoir conditions of pressure and temperature. The experimental results revealed that a significant improvement of the oil recovery is achieved by the nitrogen injection followed by the low salinity water flooding with a recovery factor of approximately 24% of the residual oil.

  11. Geostatistical analysis and isoscape of ice core derived water stable isotope records in an Antarctic macro region

    Science.gov (United States)

    Hatvani, István Gábor; Leuenberger, Markus; Kohán, Balázs; Kern, Zoltán

    2017-09-01

    Water stable isotopes preserved in ice cores provide essential information about polar precipitation. In the present study, multivariate regression and variogram analyses were conducted on 22 δ2H and 53 δ18O records from 60 ice cores covering the second half of the 20th century. Taking the multicollinearity of the explanatory variables into account, as also the model's adjusted R2 and its mean absolute error, longitude, elevation and distance from the coast were found to be the main independent geographical driving factors governing the spatial δ18O variability of firn/ice in the chosen Antarctic macro region. After diminishing the effects of these factors, using variography, the weights for interpolation with kriging were obtained and the spatial autocorrelation structure of the dataset was revealed. This indicates an average area of influence with a radius of 350 km. This allows the determination of the areas which are as yet not covered by the spatial variability of the existing network of ice cores. Finally, the regional isoscape was obtained for the study area, and this may be considered the first step towards a geostatistically improved isoscape for Antarctica.

  12. Water-stable NaLuF4-based upconversion nanophosphors with long-term validity for multimodal lymphatic imaging.

    Science.gov (United States)

    Zhou, Jing; Zhu, Xingjun; Chen, Min; Sun, Yun; Li, Fuyou

    2012-09-01

    Multimodal imaging is rapidly becoming an important tool for biomedical applications because it can compensate for the deficiencies of individual imaging modalities. Herein, multifunctional NaLuF(4)-based upconversion nanoparticles (Lu-UCNPs) were synthesized though a facile one-step microemulsion method under ambient condition. The doping of lanthanide ions (Gd(3+), Yb(3+) and Er(3+)/Tm(3+)) endows the Lu-UCNPs with high T(1)-enhancement, bright upconversion luminescence (UCL) emissions, and excellent X-ray absorption coefficient. Moreover, the as-prepared Lu-UCNPs are stable in water for more than six months, due to the protection of sodium glutamate and diethylene triamine pentacetate acid (DTPA) coordinating ligands on the surface. Lu-UCNPs have been successfully applied to the trimodal CT/MR/UCL lymphatic imaging on the modal of small animals. It is worth noting that Lu-UCNPs could be used for imaging even after preserving for over six months. In vitro transmission electron microscope (TEM), methyl thiazolyl tetrazolium (MTT) assay and histological analysis demonstrated that Lu-UCNPs exhibited low toxicity on living systems. Therefore, Lu-UCNPs could be multimodal agents for CT/MR/UCL imaging, and the concept can be served as a platform technology for the next-generation of probes for multimodal imaging. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. A Water-Stable Proton-Conductive Barium(II)-Organic Framework for Ammonia Sensing at High Humidity.

    Science.gov (United States)

    Guo, Kaimeng; Zhao, Lili; Yu, Shihang; Zhou, Wenyan; Li, Zifeng; Li, Gang

    2018-06-07

    In view of environmental protection and the need for early prediction of major diseases, it is necessary to accurately monitor the change of trace ammonia concentration in air or in exhaled breath. However, the adoption of proton-conductive metal-organic frameworks (MOFs) as smart sensors in this field is limited by a lack of ultrasensitive gas-detecting performance at high relative humidity (RH). Here, the pellet fabrication of a water-stable proton-conductive MOF, Ba( o-CbPhH 2 IDC)(H 2 O) 4 ] n (1) ( o-CbPhH 4 IDC = 2-(2-carboxylphenyl)-1 H-imidazole-4,5-dicarboxylic acid) is reported. The MOF 1 displays enhanced sensitivity and selectivity to NH 3 gas at high RHs (>85%) and 30 °C, and the sensing mechanism is suggested. The electrochemical impedance gas sensor fabricated by MOF 1 is a promising sensor for ammonia at mild temperature and high RHs.

  14. Experimental investigation of hydrogen energy share improvement in a compression ignition engine using water injection and compression ratio reduction

    International Nuclear Information System (INIS)

    Chintala, V.; Subramanian, K.A.

    2016-01-01

    Highlights: • Energy efficiency (EE) increased with increase in hydrogen (H_2) energy share. • H_2 energy share increased from 19% to 79% with combined CR reduction and water. • In-cylinder temperature decreased significantly with water addition and CR reduction. • HC, CO, smoke and NO_x emissions with water and CR are lower than base diesel. - Abstract: This study deals with the effect of water addition on enhancement of maximum hydrogen energy share in a compression ignition engine (7.4 kW rated power at 1500 rpm) under dual fuel mode. The specific water consumption (SWC) was varied from 130 to 480 g/kW h in step of 70 g/kW h using manifold and port injection methods. Subsequently, the combined effect of reduction of compression ratio (CR) of the engine (from 19.5:1 (base) to 16.5:1 and 15.4:1) along with water addition on further enhancement of hydrogen energy share is investigated. The hydrogen energy share was limited to 18.8% with conventional dual fuel mode due to knocking. However, the energy share increased to 66.5% with water addition (maximum SWC: 480 g/kW h), and 79% with combined control strategies (SWC of 340 g/kW h and CR reduction to 16.5:1). Thermal efficiency of the engine under water added dual fuel mode is higher than base diesel mode (single fuel mode), but it is lower than the conventional dual fuel mode without water. The efficiency of the engine with reduced CR and water addition is lower than the conventional dual fuel mode, however at the CR of 16.5:1 and SWC of 340 g/kW h, the efficiency is comparable with base diesel mode efficiency. Hydrocarbon, carbon monoxide, smoke, and oxides of nitrogen emissions of the engine with water addition (340 g/kW h) and CR reduction (to 16.5:1) decreased significantly as compared to base diesel mode, but slightly higher than conventional dual fuel mode.

  15. Flow Injection Analysis with Electrochemical Detection for Rapid Identification of Platinum-Based Cytostatics and Platinum Chlorides in Water

    Directory of Open Access Journals (Sweden)

    Marketa Kominkova

    2014-02-01

    Full Text Available Platinum-based cytostatics, such as cisplatin, carboplatin or oxaliplatin are widely used agents in the treatment of various types of tumors. Large amounts of these drugs are excreted through the urine of patients into wastewaters in unmetabolised forms. This phenomenon leads to increased amounts of platinum ions in the water environment. The impacts of these pollutants on the water ecosystem are not sufficiently investigated as well as their content in water sources. In order to facilitate the detection of various types of platinum, we have developed a new, rapid, screening flow injection analysis method with electrochemical detection (FIA-ED. Our method, based on monitoring of the changes in electrochemical behavior of analytes, maintained by various pH buffers (Britton-Robinson and phosphate buffer and potential changes (1,000, 1,100 and 1,200 mV offers rapid and cheap selective determination of platinum-based cytostatics and platinum chlorides, which can also be present as contaminants in water environments.

  16. Calculation of temperature field for complex heat exchange environments in multiple-layer reservoir systems on ''cold'' water injection

    Energy Technology Data Exchange (ETDEWEB)

    Vlasova, S.P.; Sukharev, G.M.; Koval' skii, E.V.

    1981-04-01

    Owing to the exhaustion of oil deposits in the arthesian basin of Eastern Subcaucasus situated in the Chechen-Ingush ASSR, it is proposed to inject cold wastewater into the wells for 25 years in order to cause underground thermal waters to rise and thus provide a steady supply of hot water for 25-30 years.

  17. No influence of CO2 on stable isotope analyses of soil waters with off-axis integrated cavity output spectroscopy (OA-ICOS).

    Science.gov (United States)

    Sprenger, Matthias; Tetzlaff, Doerthe; Soulsby, Chris

    2017-03-15

    It was recently shown that the presence of CO 2 affects the stable isotope (δ 2 H and δ 18 O values) analysis of water vapor via Wavelength-Scanned Cavity Ring-Down Spectroscopy. Here, we test how much CO 2 is emitted from soil samples and if the CO 2 in the headspace influences the isotope analysis with the direct equilibration method by Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS). The headspace above different amounts of sparkling water was sampled, and its stable isotopic composition (δ 2 H and δ 18 O values) and CO 2 concentration were measured by direct equilibration and by gas chromatography, respectively. In addition, the headspace above soil samples was analyzed in the same way. Furthermore, the gravimetric water content and the loss on ignition were measured for the soil samples. The experiment with the sparkling water showed that CO 2 does not influence the stable isotope analysis by OA-ICOS. CO 2 was emitted from the soil samples and correlated with the isotopic fractionation signal, but no causal relationship between the two was determined. Instead, the fractionation signal in pore water isotopes can be explained by soil evaporation and the CO 2 can be related to soil moisture and organic matter which both enhance microbial activity. We found, despite the high CO 2 emissions from soil samples, no need for a post-correction of the pore water stable isotope analysis results, since there is no relation between CO 2 concentrations and the stable isotope results of vapor samples obtained with OA-ICOS. © 2016 The Authors. Rapid Communications in Mass Spectrometry Published by John Wiley & Sons Ltd. © 2016 The Authors. Rapid Communications in Mass Spectrometry Published by John Wiley & Sons Ltd.

  18. Sources, migration and transformation of antimony contamination in the water environment of Xikuangshan, China: Evidence from geochemical and stable isotope (S, Sr) signatures

    International Nuclear Information System (INIS)

    Wen, Bing; Zhou, Jianwei; Zhou, Aiguo; Liu, Cunfu; Xie, Lina

    2016-01-01

    The Xikuangshan (XKS) mine in central China is the largest antimony (Sb) mine in the world. The mining activity has seriously contaminated the waters in the area. To determine the sources, migration and transformation of Sb contamination, 32 samples from groundwater (aquifer water), surface water and mine water were collected for water chemistry, trace element and S_S_O_4 and Sr stable isotope analyses. The results showed that the groundwater and surface water were in an oxidized environment. The S_S_O_4 and Sr isotope compositions in the water indicated that dissolved Sb and SO_4"2 originated from sulfide mineral (Sb_2S_3) oxidation, whereas radiogenic Sr may have been sourced from silicified limestone and stibnite in the Shetianqiao aquifer. Furthermore, a positive correlation between δ"3"4S_S_O_4 and δ"8"7Sr values revealed that the Sr, S and Sb in the waters had a common contamination source, i.e., silicified limestone and stibnite, whereas the Sr, S and Sb in rock and ore were sourced from Proterozoic basement clastics. The analysis also indicated that the isotope composition of dissolved SO_4"2 "− had been influenced by slight bacterial SO_4 reduction in the Magunao aquifer. Mining or rock collapse may have caused Shetianqiao aquifer water to contaminate the Magunao aquifer water via mixing. This study has demonstrated that the stable isotopes of "3"4S_S_O_4 and "8"7Sr, combined with hydrochemical methods, are effective in tracking the sources, migration and transformation of Sb contamination. - Highlights: • Mining activities at XKS mine have caused serious water contamination. • The characteristics of Sb contamination in water environment are still unclear. • Combine S isotopes of sulfate and Sr isotopes with hydrochemical methods. • Sr, S, and Sb in natural water had a common source: silicified limestone and stibnite. • Shetianqiao aquifer water contaminated the Magunao aquifer water via mixing.

  19. Effects of intracutaneous injections of sterile water in patients with acute low back pain: a randomized, controlled, clinical trial

    Directory of Open Access Journals (Sweden)

    J.Z. Cui

    2016-03-01

    Full Text Available Intracutaneous sterile water injection (ISWI is used for relief of low back pain during labor, acute attacks of urolithiasis, chronic neck and shoulder pain following whiplash injuries, and chronic myofascial pain syndrome. We conducted a randomized, double-blinded, placebo-controlled trial to evaluate the effect of ISWI for relief of acute low back pain (aLBP. A total of 68 patients (41 females and 27 males between 18 and 55 years old experiencing aLBP with moderate to severe pain (scores ≥5 on an 11-point visual analogue scale [VAS] were recruited and randomly assigned to receive either ISWIs (n=34 or intracutaneous isotonic saline injections (placebo treatment; n=34. The primary outcome was improvement in pain intensity using the VAS at 10, 45, and 90 min and 1 day after treatment. The secondary outcome was functional improvement, which was assessed using the Patient-Specific Functional Scale (PSFS 1 day after treatment. The mean VAS score was significantly lower in the ISWI group than in the control group at 10, 45, and 90 min, and 1 day after injection (P<0.05, t-test. The mean increment in PSFS score of the ISWI group was 2.9±2.2 1 day after treatment, while that in the control group was 0.9±2.2. Our study showed that ISWI was effective for relieving pain and improving function in aLBP patients at short-term follow-up. ISWI might be an alternative treatment for aLBP patients, especially in areas where medications are not available, as well as in specific patients (e.g., those who are pregnant or have asthma, who are unable to receive medications or other forms of analgesia because of side effects.

  20. State of radionuclides in seawater. Comparison of natural stable and artificial radioactive isotope s of mercury and zinc in natural waters of the arid zone of the USSR

    International Nuclear Information System (INIS)

    Rakhmatov, U; Khikmatov, K; Kist, A.A.; Kulmatov, R.A.; Teshabaev, S.T.; Volkov, A.A.

    1986-01-01

    This paper studies the state of stable and artificial radioactive isotopes of merury and zinc in natural waters of the arid zone of the USSR by radioactivity and radiochemical methods. Convergent results have been obtained for the dissolved forms of mercury and zinc in natural waters of the arid zone in a comparison of the results of radioactivation analysis and laboratory simulation using the radionuclides mercury-203 and zinc-65

  1. Geochemical and stable isotopic constraints on the generation and passive treatment of acidic, Fe-SO{sub 4} rich waters

    Energy Technology Data Exchange (ETDEWEB)

    Matthies, Romy, E-mail: rmatthies@uwaterloo.ca [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Aplin, Andrew C., E-mail: andrew.aplin@ncl.ac.uk [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Boyce, Adrian J., E-mail: a.boyce@suerc.gla.ac.uk [Scottish Universities Environment Research Centre, East Kilbride, G75 0QF (United Kingdom); Jarvis, Adam P., E-mail: a.p.jarvis@ncl.ac.uk [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom)

    2012-03-15

    Reducing and Alkalinity Producing Systems (RAPS) remediate net-acidic metalliferous mine drainage by creating anoxic conditions in which bacterial sulfate reduction (BSR) raises alkalinity and drives the precipitation of iron and other chalcophilic elements as sulfides. We report chemical and stable isotopic data from a study monitoring the biogeochemical processes involved in the generation of mine waters and their remediation by two RAPS. Sulfur isotopes show that sulfate in all mine waters has a common source (pyrite oxidation), whilst oxygen isotopes show that oxidation of pyritic sulfur is mediated by Fe(III){sub aq}. The isotopic composition of dissolved sulfide, combined with the sulfur and oxygen isotopic composition of sulfate in RAPS effluents, proves BSR and details its dual isotope systematics. The occurrence and isotopic composition of solid phase iron sulfides indicate the removal of reduced sulfur within the RAPS, with significant amounts of elemental sulfur indicating reoxidation steps. However, only 0 to 9% of solid phase iron occurs as Fe sulfides, with approximately 70% of the removed iron occurs as Fe(III) (hydr)oxides. Some of the (hydr)oxide is supplied to the wetland as solids and is simply filtered by the wetland substrate, playing no role in alkalinity generation or proton removal. However, the majority of iron is supplied as dissolved Fe(II), indicating that acid generating oxidation and hydrolysis reactions dominate iron removal. The overall contribution of BSR to the sulfur geochemistry in the RAPS is limited and sulfate retention is dominated by sulfate precipitation, comparable to aerobic treatment systems, and show that the proton acidity resulting from iron oxidation and hydrolysis must be subsequently neutralised by calcite dissolution and/or BSR deeper in the RAPS sediments. BSR is not as important as previously thought for metal removal in RAPS. The results have practical consequences for the design, treatment performance and long

  2. Decoration of Cotton Fibers with a Water-Stable Metal–Organic Framework (UiO-66 for the Decomposition and Enhanced Adsorption of Micropollutants in Water

    Directory of Open Access Journals (Sweden)

    Marion Schelling

    2018-02-01

    Full Text Available We report on the successful functionalization of cotton fabrics with a water-stable metal–organic framework (MOF, UiO-66, under mild solvothermal conditions (80 °C and its ability to adsorb and degrade water micropollutants. The functionalized cotton samples were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, energy-dispersive X-ray spectroscopy (EDX, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FTIR, and X-ray photoelectron spectroscopy (XPS. UiO-66 crystals grew in a uniform and conformal manner over the surface of the cotton fibers. The cotton fabrics functionalized with UiO-66 frameworks exhibited an enhanced uptake capacity for methylchlorophenoxypropionic acid (MCPP, a commonly used herbicide. The functionalized fabrics also showed photocatalytic activity, demonstrated by the degradation of acetaminophen, a common pharmaceutical compound, under simulated sunlight irradiation. These results indicate that UiO-66 can be supported on textile substrates for filtration and photocatalytic purposes and that these substrates can find applications in wastewater decontamination and micropollutant degradation.

  3. An Energy Analysis on Gasification of Sewage Sludge by a Direct Injection in Supercritical Water

    NARCIS (Netherlands)

    Yukananto, Riza; Louwes, Alexander Charnchai; Bramer, Eduard A.; Brem, Gerrit

    2017-01-01

    Supercritical Water Gasification is an efficient technology in converting wet biomass into H2 and CH4 in comparison to other conventional thermochemical processes. Coke deposition, however, remains as a major challenge in this technology. Coke formation is the result of polymerization reactions that

  4. Quantification of long-term wastewater fluxes at the surface water/groundwater-interface: An integrative model perspective using stable isotopes and acesulfame

    Energy Technology Data Exchange (ETDEWEB)

    Engelhardt, I., E-mail: i.engelhardt@fz-juelich.de [Forschungszentrum Jülich, Institute of Bio- and Geosciences, Agrosphere — IBG-3 (Germany); Technical University of Darmstadt, Institute of Applied Geosciences (Germany); Barth, J.A.C. [GeoZentrum Nordbayern, University of Erlangen-Nuremberg (Germany); Bol, R. [Forschungszentrum Jülich, Institute of Bio- and Geosciences, Agrosphere — IBG-3 (Germany); Schulz, M.; Ternes, T.A. [Federal Institute of Hydrology (BfG) (Germany); Schüth, C. [Technical University of Darmstadt, Institute of Applied Geosciences (Germany); van Geldern, R. [GeoZentrum Nordbayern, University of Erlangen-Nuremberg (Germany)

    2014-01-01

    The suitability of acesulfame to trace wastewater-related surface water fluxes from streams into the hyporheic and riparian zones over long-term periods was investigated. The transport behavior of acesulfame was compared with the transport of water stable isotopes (δ{sup 18}O or δ{sup 2}H). A calibrated model based on a joint inversion of temperature, acesulfame, and piezometric pressure heads was employed in a model validation using data sets of acesulfame and water stable isotopes collected over 5 months in a stream and groundwater. The spatial distribution of fresh water within the groundwater resulting from surface water infiltration was estimated by computing groundwater ages and compared with the predicted acesulfame plume obtained after 153 day simulation time. Both, surface water ratios calculated with a mixing equation from water stable isotopes and simulated acesulfame mass fluxes, were investigated for their ability to estimate the contribution of wastewater-related surface water inflow within groundwater. The results of this study point to limitations for the application of acesulfame to trace surface water–groundwater interactions properly. Acesulfame completely missed the wastewater-related surface water volumes that still remained in the hyporheic zone under stream-gaining conditions. In contrast, under stream-losing conditions, which developed after periods of stagnating hydraulic exchange, acesulfame based predictions lead to an overestimation of the surface water volume of up to 25% in the riparian zone. If slow seepage velocities prevail a proportion of acesulfame might be stored in smaller pores, while when released under fast flowing water conditions it will travel further downstream with the groundwater flow direction. Therefore, under such conditions acesulfame can be a less-ideal tracer in the hyporheic and riparian zones and additional monitoring with other environmental tracers such as water stable isotopes is highly recommended

  5. A Theoretical and Experimental Analysis of Post-Compression Water Injection in a Rolls-Royce M250 Gas Turbine Engine

    Science.gov (United States)

    2015-05-18

    ROLLS-ROYCE M250 GAS TURBINE ENGINE by Midshipman 1/C Brian R. He United States Naval Academy Annapolis, Maryland...Injection in a Rolls- Royce M250 Gas Turbine Engine 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) He...output, efficiency, operating conditions, and emissions of injecting water at the compressor discharge of a Rolls-Royce M250 . The results

  6. Subcutaneous injection of water-soluble multi-walled carbon nanotubes in tumor-bearing mice boosts the host immune activity

    International Nuclear Information System (INIS)

    Meng Jie; Yang Man; Jia Fumin; Kong Hua; Zhang Weiqi; Xu Haiyan; Wang Chaoying; Xie Sishen; Xing Jianmin

    2010-01-01

    The immunological responses induced by oxidized water-soluble multi-walled carbon nanotubes on a hepatocarcinoma tumor-bearing mice model via a local administration of subcutaneous injection were investigated. Experimental results show that the subcutaneously injected carbon nanotubes induced significant activation of the complement system, promoted inflammatory cytokines' production and stimulated macrophages' phagocytosis and activation. All of these responses increased the general activity of the host immune system and inhibited the progression of tumor growth.

  7. Subcutaneous injection of water-soluble multi-walled carbon nanotubes in tumor-bearing mice boosts the host immune activity

    Science.gov (United States)

    Meng, Jie; Yang, Man; Jia, Fumin; Kong, Hua; Zhang, Weiqi; Wang, Chaoying; Xing, Jianmin; Xie, Sishen; Xu, Haiyan

    2010-04-01

    The immunological responses induced by oxidized water-soluble multi-walled carbon nanotubes on a hepatocarcinoma tumor-bearing mice model via a local administration of subcutaneous injection were investigated. Experimental results show that the subcutaneously injected carbon nanotubes induced significant activation of the complement system, promoted inflammatory cytokines' production and stimulated macrophages' phagocytosis and activation. All of these responses increased the general activity of the host immune system and inhibited the progression of tumor growth.

  8. Subcutaneous injection of water-soluble multi-walled carbon nanotubes in tumor-bearing mice boosts the host immune activity

    Energy Technology Data Exchange (ETDEWEB)

    Jie, Meng; Man, Yang; Fumin, Jia; Hua, Kong; Weiqi, Zhang; Haiyan, Xu [Department of Biomedical Engineering, Institute of Basic Medical Sciences and School of Basic Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005 (China); Chaoying, Wang; Sishen, Xie [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 8 Nan San Jie, Zhongguancun, Beijing100080 (China); Xing Jianmin, E-mail: xuhy@pumc.edu.cn [Centre for Evidence-Based Chinese Medicine, Beijing University of Chinese Medicine, 11 Bei San Huan Dong Lu, Beijing 100029 (China)

    2010-04-09

    The immunological responses induced by oxidized water-soluble multi-walled carbon nanotubes on a hepatocarcinoma tumor-bearing mice model via a local administration of subcutaneous injection were investigated. Experimental results show that the subcutaneously injected carbon nanotubes induced significant activation of the complement system, promoted inflammatory cytokines' production and stimulated macrophages' phagocytosis and activation. All of these responses increased the general activity of the host immune system and inhibited the progression of tumor growth.

  9. Research and application of multi-hydrogen acidizing technology of low-permeability reservoirs for increasing water injection

    Science.gov (United States)

    Ning, Mengmeng; Che, Hang; Kong, Weizhong; Wang, Peng; Liu, Bingxiao; Xu, Zhengdong; Wang, Xiaochao; Long, Changjun; Zhang, Bin; Wu, Youmei

    2017-12-01

    The physical characteristics of Xiliu 10 Block reservoir is poor, it has strong reservoir inhomogeneity between layers and high kaolinite content of the reservoir, the scaling trend of fluid is serious, causing high block injection well pressure and difficulty in achieving injection requirements. In the past acidizing process, the reaction speed with mineral is fast, the effective distance is shorter and It is also easier to lead to secondary sedimentation in conventional mud acid system. On this point, we raised multi-hydrogen acid technology, multi-hydrogen acid release hydrogen ions by multistage ionization which could react with pore blockage, fillings and skeletal effects with less secondary pollution. Multi-hydrogen acid system has advantages as moderate speed, deep penetration, clay low corrosion rate, wet water and restrains precipitation, etc. It can reach the goal of plug removal in deep stratum. The field application result shows that multi-hydrogen acid plug removal method has good effects on application in low permeability reservoir in Block Xiliu 10.

  10. Modelling transient temperature distribution for injecting hot water through a well to an aquifer thermal energy storage system

    Science.gov (United States)

    Yang, Shaw-Yang; Yeh, Hund-Der; Li, Kuang-Yi

    2010-10-01

    Heat storage systems are usually used to store waste heat and solar energy. In this study, a mathematical model is developed to predict both the steady-state and transient temperature distributions of an aquifer thermal energy storage (ATES) system after hot water is injected through a well into a confined aquifer. The ATES has a confined aquifer bounded by aquicludes with different thermomechanical properties and geothermal gradients along the depth. Consider that the heat is transferred by conduction and forced convection within the aquifer and by conduction within the aquicludes. The dimensionless semi-analytical solutions of temperature distributions of the ATES system are developed using Laplace and Fourier transforms and their corresponding time-domain results are evaluated numerically by the modified Crump method. The steady-state solution is obtained from the transient solution through the final-value theorem. The effect of the heat transfer coefficient on aquiclude temperature distribution is appreciable only near the outer boundaries of the aquicludes. The present solutions are useful for estimating the temperature distribution of heat injection and the aquifer thermal capacity of ATES systems.

  11. Determination of pesticides and pesticide degradates in filtered water by direct aqueous-injection liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Sandstrom, Mark W.; Kanagy, Leslie K.; Anderson, Cyrissa A.; Kanagy, Christopher J.

    2016-01-11

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for determination of 229 pesticides compounds (113 pesticides and 116 pesticide degradates) in filtered water samples from stream and groundwater sites. The pesticides represent a broad range of chemical classes and were selected based on criteria such as current-use intensity, probability of occurrence in streams and groundwater, and toxicity to humans or aquatic organisms. More than half of the analytes are pesticide degradates. The method involves direct injection of a 100-microliter (μL) sample onto the LC-MS/MS without any sample preparation other than filtration. Samples are analyzed with two injections, one in electrospray ionization (ESI) positive mode and one in ESI negative mode, using dynamic multiple reaction monitoring (MRM) conditions, with two MRM transitions for each analyte. The LC-MS/MS instrument parameters were optimized for highest sensitivity for the most analytes. This report describes the analytical method and presents characteristics of the method validation including bias and variability, detection levels, and holding-time studies.

  12. Sodium hydroxide injection passivation work for the reactor water clean-up system in a new ABWR plant

    International Nuclear Information System (INIS)

    Wen, Tung-Jen; Lu, Ju-Huang

    2012-09-01

    Several studies have identified that Co-58 and Co-60 as the primary source of radiation build up on out-of-core components in new BWR plants. The deposition rate of Co on stainless steel and carbon steel is shown to be controlled mainly by the thickness of oxide films and its morphology formed through pretreatment. The passivation treatment was implemented accordingly at Lungmen unit 1 in an ABWR plant in September 2010. It is determined that the passivation conditions should be maintained at the temperature of 180∼230 deg. C, pH of 8.0∼8.5 and dissolved oxygen content over 400 ppb. The films would provide effective protection against radioactive deposition. The application of the pre-filming process on piping before the pre-operation is done during the flow induced vibration test (FIV) period. The protectiveness of stable magnetite can be increased by the pH control under the specific condition. The pre-filming control process and evaluation of passivation effectiveness is discussed in detail based on the surface analysis of the passivated specimens. Many efforts have been devoted to sodium hydroxide injection method for pH control of the system through the filter demineralizer under smooth operation. A comparison of test specimens on the properties of oxide film formed between laboratory and in-plant tests through alkaline treatment are also shown in this report. (authors)

  13. Sequential determination of multi-nutrient elements in natural water samples with a reverse flow injection system.

    Science.gov (United States)

    Lin, Kunning; Ma, Jian; Yuan, Dongxing; Feng, Sichao; Su, Haitao; Huang, Yongming; Shangguan, Qipei

    2017-05-15

    An integrated system was developed for automatic and sequential determination of NO 2 - , NO 3 - , PO 4 3- , Fe 2+ , Fe 3+ and Mn 2+ in natural waters based on reverse flow injection analysis combined with spectrophotometric detection. The system operation was controlled by a single chip microcomputer and laboratory-programmed software written in LabVIEW. The experimental parameters for each nutrient element analysis were optimized based on a univariate experimental design, and interferences from common ions were evaluated. The upper limits of the linear range (along with detection limit, µmolL -1 ) of the proposed method was 20 (0.03), 200 (0.7), 12 (0.3), 5 (0.03), 5 (0.03), 9 (0.2) µmolL -1 , for NO 2 - , NO 3 - , PO 4 3- , Fe 2+ , Fe 3+ and Mn 2+ , respectively. The relative standard deviations were below 5% (n=9-13) and the recoveries varied from 88.0±1.0% to 104.5±1.0% for spiked water samples. The sample throughput was about 20h -1 . This system has been successfully applied for the determination of multi-nutrient elements in different kinds of water samples and showed good agreement with reference methods (slope 1.0260±0.0043, R 2 =0.9991, n=50). Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Determination of hydrogen peroxide in water by chemiluminescence detection, (1). Flow injection type hydrogen peroxide detection system

    International Nuclear Information System (INIS)

    Yamashiro, Naoya; Uchida, Shunsuke; Satoh, Yoshiyuki; Morishima, Yusuke; Yokoyama, Hiroaki; Satoh, Tomonori; Sugama, Junichi; Yamada, Rie

    2004-01-01

    A flow injection type hydrogen peroxide detection system with a sub-ppb detection limit has been developed to determine hydrogen peroxide concentration in water sampled from a high temperature, high pressure hydrogen peroxide water loop. The hydrogen peroxide detector is based on luminol chemiluminescence spectroscopy. A small amount of sample water (20 μl) is mixed with a reagent mixture, an aqueous solution of luminol and Co 2+ catalyst, in a mixing cell which is installed just upstream from the detection cell. The optimum values for pH and the concentrations of luminol and Co 2+ ion have been determined to ensure a lower detectable limit and a higher reproducibility. The photocurrent detected by the detection system is expressed by a linear function of the hydrogen peroxide concentration in the region of lower concentration ([H 2 O 2 ] 2 O 2 ] in the region of higher concentration ([H 2 O 2 ] > 10 ppb). The luminous intensity of luminol chemiluminescence is the highest when pH of the reagent mixture is 11.0. Optimization of the major parameters gives the lowest detectable limit of 0.3 ppb. (author)

  15. Mapping water exchange rates in rat tumor xenografts using the late-stage uptake following bolus injections of contrast agent.

    Science.gov (United States)

    Bailey, Colleen; Moosvi, Firas; Stanisz, Greg J

    2014-05-01

    To map the intra-to-extracellular water exchange rate constant in rat xenografts using a two-compartment model of relaxation with water exchange and a range of contrast agent concentrations and compare with histology. MDA-MB-231 cells were xenografted into six nude rats. Three bolus injections of gadodiamide were administered. When uptake in the tumor demonstrated a steady-state, T1 data were acquired by spoiled gradient recalled acquisitions at four flip angles. A global fit of data to a two-compartment model incorporating exchange was performed, assuming a distribution volume of 20% of the rat. Voxels that did not reach steady-state and were excluded from parametric maps tended to be in large necrotic areas. TUNEL-negative (nonapoptotic) regions tended to have well-defined error bounds, with an average intra-to-extracellular exchange rate constant of 0.6 s(-1) . Apoptotic regions had higher exchange, but poorly determined upper bounds, with goodness of fit similar to that for a model assuming infinitely fast exchange. A lower bound of >3 s(-1) was used to establish voxels where the exchange rate constant was fast despite a large upper bound. Water exchange rates were higher in apoptotic regions, but examination of statistical errors was an important step in the mapping process. Copyright © 2013 Wiley Periodicals, Inc.

  16. Feasibility of water injection into the turbine coolant to permit gas turbine contingency power for helicopter application

    Science.gov (United States)

    Vanfossen, G. J.

    1983-01-01

    A system which would allow a substantially increased output from a turboshaft engine for brief periods in emergency situations with little or no loss of turbine stress rupture life is proposed and studied analytically. The increased engine output is obtained by overtemperaturing the turbine; however, the temperature of the compressor bleed air used for hot section cooling is lowered by injecting and evaporating water. This decrease in cooling air temperature can offset the effect of increased gas temperature and increased shaft speed and thus keep turbine blade stress rupture life constant. The analysis utilized the NASA-Navy-Engine-Program or NNEP computer code to model the turboshaft engine in both design and off-design modes. This report is concerned with the effect of the proposed method of power augmentation on the engine cycle and turbine components. A simple cycle turboshaft engine with a 16:1 pressure ratio and a 1533 K (2760 R) turbine inlet temperature operating at sea level static conditions was studied to determine the possible power increase and the effect on turbine stress rupture life that could be expected using the proposed emergency cooling scheme. The analysis showed a 54 percent increse in output power can be achieved with no loss in gas generator turbine stress rupture life. A 231 K (415 F) rise in turbine inlet temperature is required for this level of augmentation. The required water flow rate was found to be .0109 kg water per kg of engine air flow.

  17. Corrosion of low carbon steel by microorganisms from the 'pigging' operation debris in water injection pipelines.

    Science.gov (United States)

    Cote, Claudia; Rosas, Omar; Sztyler, Magdalena; Doma, Jemimah; Beech, Iwona; Basseguy, Régine

    2014-06-01

    Present in all environments, microorganisms develop biofilms adjacent to the metallic structures creating corrosion conditions which may cause production failures that are of great economic impact to the industry. The most common practice in the oil and gas industry to annihilate these biofilms is the mechanical cleaning known as "pigging". In the present work, microorganisms from the "pigging" operation debris are tested biologically and electrochemically to analyse their effect on the corrosion of carbon steel. Results in the presence of bacteria display the formation of black corrosion products allegedly FeS and a sudden increase (more than 400mV) of the corrosion potential of electrode immersed in artificial seawater or in field water (produced water mixed with aquifer seawater). Impedance tests provided information about the mechanisms of the interface carbon steel/bacteria depending on the medium used: mass transfer limitation in artificial seawater was observed whereas that in field water was only charge transfer phenomenon. Denaturing Gradient Gel Electrophoresis (DGGE) results proved that bacterial diversity decreased when cultivating the debris in the media used and suggested that the bacteria involved in the whole set of results are mainly sulphate reducing bacteria (SRB) and some other bacteria that make part of the taxonomic order Clostridiales. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Sub-1min separation in sequential injection chromatography for determination of synthetic water-soluble dyes in pharmaceutical formulation.

    Science.gov (United States)

    Davletbaeva, Polina; Chocholouš, Petr; Bulatov, Andrey; Šatínský, Dalibor; Solich, Petr

    2017-09-05

    Sequential Injection Chromatography (SIC) evolved from fast and automated non-separation Sequential Injection Analysis (SIA) into chromatographic separation method for multi-element analysis. However, the speed of the measurement (sample throughput) is due to chromatography significantly reduced. In this paper, a sub-1min separation using medium polar cyano monolithic column (5mm×4.6mm) resulted in fast and green separation with sample throughput comparable with non-separation flow methods The separation of three synthetic water-soluble dyes (sunset yellow FCF, carmoisine and green S) was in a gradient elution mode (0.02% ammonium acetate, pH 6.7 - water) with flow rate of 3.0mLmin -1 corresponding with sample throughput of 30h -1 . Spectrophotometric detection wavelengths were set to 480, 516 and 630nm and 10Hz data collection rate. The performance of the separation was described and discussed (peak capacities 3.48-7.67, peak symmetries 1.72-1.84 and resolutions 1.42-1.88). The method was represented by validation parameters: LODs of 0.15-0.35mgL -1 , LOQs of 0.50-1.25mgL -1 , calibration ranges 0.50-150.00mgL -1 (r>0.998) and repeatability at 10.0mgL -1 of RSD≤0.98% (n=6). The method was used for determination of the dyes in "forest berries" colored pharmaceutical cough-cold formulation. The sample matrix - pharmaceuticals and excipients were not interfering with vis determination because of no retention in the separation column and colorless nature. The results proved the concept of fast and green chromatography approach using very short medium polar monolithic column in SIC. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Stable isotopes, δ18O and δ2H, in the study of water balance of Lake Massoko, Tanzania: Investigation of the exchange between lake and underground water

    International Nuclear Information System (INIS)

    Bergonzini, L.; Gibert, E.; Winckel, A.

    2002-01-01

    Full text: The stable oxygen and deuterium isotope compositions of a lake depend upon its water balance. Therefore the balance equations of stable isotopes, which imply calculation of the composition of evaporating moisture α E , provide information for assessing the water balance. In most cases, this approach is used to investigate the relationships between lakes and groundwater. Lake Massoko (8 deg. 20'S, 33 deg. 45'E, 870 m.a.s.l.) is a freshwater maar-lake without surface outlet. The lake surface and its runoff area cover 0.38 and 0.55 km 2 respectively. In contrast with the mean annual rainfall in the other parts of south Tanzania (1000-1200 mm y -1 ), the presence of Lake Malawi to the South, and the high ranges to the North (Mounts Poroto, Rungwe and Livingstone) imply local climatic features. Air masses overloaded with humidity bypassing Lake Malawi are submitted, especially in April, to ascending currents, producing rainfalls up to 2450 mm y -1 over Massoko area. Because of the evaporation rate from the lake's surface (around 2100 mm y -1 ) and without taking into account the runoff from the drainage basin, hydrological balance is positive and imply underground lost. One of most difficult points in the establishment of the isotope balances is the calculation of the composition of the evaporated water (δ E ), which requires an estimation of the isotopic composition of the water vapour in the atmosphere over the lake (δ Atm ). Without direct measurements, two ways can be used for the determination of the vapour composition (i) equilibrium with precipitation and reconstitution from them, or (ii) calculation from the balances of a terminal lake of the region. Both approaches are presented and compared, but only the second one allows physical solutions. δ Atm determined from Lake Rukwa hydrological and isotope balances has been used to calculate values for δ E over Lake Massoko. The estimation of δ Atm obtained from Lake Rukwa budgets presents a deuterium

  20. Design and synthesis of a water-stable anionic uranium-based metal-organic framework (MOF) with ultra large pores

    Energy Technology Data Exchange (ETDEWEB)

    Li, Peng; Vermeulen, Nicolaas A.; Gong, Xirui; Malliakas, Christos D.; Stoddart, J. Fraser; Hupp, Joseph T. [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Farha, Omar K. [Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; King Abdulaziz Univ., Jeddah (Saudi Arabia). Dept. of Chemistry

    2016-08-22

    Ionic metal-organic frameworks (MOFs) are a subclass of porous materials that have the ability to incorporate different charged species in confined nanospace by ion-exchange. To date, however, very few examples combining mesoporosity and water stability have been realized in ionic MOF chemistry. Herein, we report the rational design and synthesis of a water-stable anionic mesoporous MOF based on uranium and featuring tbo-type topology. The resulting tbo MOF exhibits exceptionally large open cavities (3.9 nm) exceeding those of all known anionic MOFs. By supercritical CO{sub 2} activation, a record-high Brunauer-Emmett-Teller (BET) surface area (2100 m{sup 2} g{sup -1}) for actinide-based MOFs has been obtained. Most importantly, however, this new uranium-based MOF is water-stable and able to absorb positively charged ions selectively over negatively charged ones, enabling the efficient separation of organic dyes and biomolecules.

  1. Direct injection analysis of fatty and resin acids in papermaking process waters by HPLC/MS.

    Science.gov (United States)

    Valto, Piia; Knuutinen, Juha; Alén, Raimo

    2011-04-01

    A novel HPLC-atmospheric pressure chemical ionization/MS (HPLC-APCI/MS) method was developed for the rapid analysis of selected fatty and resin acids typically present in papermaking process waters. A mixture of palmitic, stearic, oleic, linolenic, and dehydroabietic acids was separated by a commercial HPLC column (a modified stationary C(18) phase) using gradient elution with methanol/0.15% formic acid (pH 2.5) as a mobile phase. The internal standard (myristic acid) method was used to calculate the correlation coefficients and in the quantitation of the results. In the thorough quality parameters measurement, a mixture of these model acids in aqueous media as well as in six different paper machine process waters was quantitatively determined. The measured quality parameters, such as selectivity, linearity, precision, and accuracy, clearly indicated that, compared with traditional gas chromatographic techniques, the simple method developed provided a faster chromatographic analysis with almost real-time monitoring of these acids. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Role of angiotensin II and vasopressin receptors within the supraoptic nucleus in water and sodium intake induced by the injection of angiotensin II into the medial septal area

    Directory of Open Access Journals (Sweden)

    Antunes V.R.

    1998-01-01

    Full Text Available In this study we investigated the effects of the injection into the supraoptic nucleus (SON of non-peptide AT1- and AT2-angiotensin II (ANG II receptor antagonists, DuP753 and PD123319, as well as of the arginine-vasopressin (AVP receptor antagonist d(CH25-Tyr(Me-AVP, on water and 3% NaCl intake induced by the injection of ANG II into the medial septal area (MSA. The effects on water or 3% NaCl intake were assessed in 30-h water-deprived or in 20-h water-deprived furosemide-treated adult male rats, respectively. The drugs were injected in 0.5 ml over 30-60 s. Controls were injected with a similar volume of 0.15 M NaCl. Antagonists were injected at doses of 20, 80 and 180 nmol. Water and sodium intake was measured over a 2-h period. Previous administration of the AT1 receptor antagonist DuP753 into the SON decreased water (65%, N = 10, P<0.01 and sodium intake (81%, N = 8, P<0.01 induced by the injection of ANG II (10 nmol into the MSA. Neither of these responses was significantly changed by injection of the AT2-receptor antagonist PD123319 into the SON. On the other hand, while there was a decrease in water intake (45%, N = 9, P<0.01, ANG II-induced sodium intake was significantly increased (70%, N = 8, P<0.01 following injection of the V1-type vasopressin antagonist d(CH25-Tyr(Me-AVP into the SON. These results suggest that both AT1 and V1 receptors within the SON may be involved in water and sodium intake induced by the activation of ANG II receptors within the MSA. Furthermore, they do not support the involvement of MSA AT2 receptors in the mediation of these responses.

  3. Highly stable copper oxide composite as an effective photocathode for water splitting via a facile electrochemical synthesis strategy

    KAUST Repository

    Zhang, Zhonghai; Wang, Peng

    2012-01-01

    focused on n-type metal oxide semiconductors as photoanodes, whereas studies of p-type metal oxide semiconductors as photocathodes where hydrogen is generated are scarce. In this paper, highly efficient and stable copper oxide composite photocathode

  4. The immunostimulatory effects of hot-water extract of Gelidium amansii via immersion, injection and dietary administrations on white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus.

    Science.gov (United States)

    Fu, Yu-Win; Hou, Wen-Ying; Yeh, Su-Tuen; Li, Chiu-Hsia; Chen, Jiann-Chu

    2007-06-01

    The total haemocyte count (THC), phenoloxidase activity, and respiratory burst were examined when white shrimp Litopenaeus vannamei were immersed in seawater (34 per thousand) containing hot-water extract of red alga Gelidium amansii at 200, 400 and 600 mg l(-1), injected with hot-water extract at 4 and 6 microg g(-1) shrimp, and fed diets containing hot-water extract at 0, 0.5, 1.0 and 2.0 g kg(-1). These parameters increased significantly when shrimp were immersed in seawater containing hot-water extract at 400 and 600 mg l(-1) after 1h, when shrimp were injected with hot-water extract at 6 microg g(-1) shrimp after one day, and when shrimp were fed diets containing hot-water extract at 1.0 and 2.0 g kg(-1) after 14 days. Phagocytic activity and clearance efficiency were significantly higher for the shrimp that were fed diets containing hot-water extract at 1.0 and 2.0 g kg(-1) than those of shrimp that were fed diets containing hot-water extract at 0 and 0.5 g kg(-1) after 14 and 28 days. In a separate experiment, L. vannamei which had received hot-water extract via injection, or fed diets containing hot-water extract, were challenged after 3h or 28 days with V. alginolyticus at 2 x 10(6) cfu shrimp(-1) and 1 x 10(6) cfu shrimp(-1), respectively, and then placed in seawater. The survival of shrimp that were injected with hot-water extract at 6 microg g(-1) was significantly higher than that of control shrimp after 1 day, and the survival of shrimp fed diets containing hot-water extract at 0.5, 1.0 and 2.0 g kg(-1) increased significantly after 3 days as well as at the end of the experiment (6 days after the challenge), respectively. It was concluded that L. vannamei that were immersed in hot-water extract at 400 mg l(-1), injected with hot-water extract at 6 microg g(-1) shrimp, and fed hot-water extract of G. amansii at 2.0 g kg(-1) or less showed increased immune ability as well as resistance to V. alginolyticus infection.

  5. Determination of thiram in natural waters using flow-injection with cerium(IV)-quinine chemiluminescence system.

    Science.gov (United States)

    Waseem, Amir; Yaqoob, Mohammad; Nabi, Abdul

    2010-01-01

    A simple and rapid flow-injection chemiluminescence method has been developed for the determination of dithiocarbamate fungicide thiram based on the chemiluminescence reaction of thiram with ceric sulfate and quinine in aqueous sulfuric acid. The present method allowed the determination of thiram in the concentration range of 7.5-2500 ng/mL and the detection limit (signal-to-noise ratio = 3) was 7.5 ng/mL with sample throughput of 120/h. The relative standard deviation was 2.5% for 10 replicate analyses of 500 ng/mL thiram. The effects of foreign species including various anions and cations present in water at environmentally relevant concentrations and some pesticides were also investigated. The proposed method was applied to determine thiram in spiked natural waters using octadecyl bonded phase silica (C(18)) cartridges for solid-phase extraction. The recoveries were in the range 99 +/- 1 to 104 +/- 1%. Copyright (c) 2009 John Wiley & Sons, Ltd.

  6. Influence of binder system and temperature on rheological properties of water atomized 316L powder injection moulding feedstocks

    Directory of Open Access Journals (Sweden)

    Uğur GÖKMEN

    2016-02-01

    Full Text Available In order to obtain a proper powder injection molding the rheological behavior of feedstocks should be known. To determine the binder effect on the rheological behavior of 316L stainless steel powders feedstock two different feedstock were prepared. In the current experiments water atomized 316L stainless steel powders (-20 µm were used. Two types of binders, one of which is mainly paraffin wax can be dissolved in heptane and the other Polietilenglikol (PEG based and can be dissolved in water, were used. Polypropylene was used as binder and steric acid was used as lubricant for both binder systems as skeleton binder. Dry binder system were mixed for 30 min in a three dimensional Turbola. Capillary rheometer was used to characterize the rheological properties of feed stocks at 150-200 °C and a pressures of 0.165-2.069 MPa. Powder loading capacity of PEG and PW based feed stocks were found to be %55 and %61 respectively. The lowest viscosity of PEG and PW based feed stocks were found to be 304.707 Pa.s and 48.857 Pa.s respectively.Keywords: PIM, Binder, Rheological properties

  7. Hydrogeochemistry and quality of surface water and groundwater in the vicinity of Lake Monoun, West Cameroon: approach from multivariate statistical analysis and stable isotopic characterization.

    Science.gov (United States)

    Kamtchueng, Brice T; Fantong, Wilson Y; Wirmvem, Mengnjo J; Tiodjio, Rosine E; Takounjou, Alain F; Ndam Ngoupayou, Jules R; Kusakabe, Minoru; Zhang, Jing; Ohba, Takeshi; Tanyileke, Gregory; Hell, Joseph V; Ueda, Akira

    2016-09-01

    With the use of conventional hydrogeochemical techniques, multivariate statistical analysis, and stable isotope approaches, this paper investigates for the first time surface water and groundwater from the surrounding areas of Lake Monoun (LM), West Cameroon. The results reveal that waters are generally slightly acidic to neutral. The relative abundance of major dissolved species are Ca(2+) > Mg(2+) > Na(+) > K(+) for cations and HCO3 (-) ≫ NO3 (-) > Cl(-) > SO4 (2-) for anions. The main water type is Ca-Mg-HCO3. Observed salinity is related to water-rock interaction, ion exchange process, and anthropogenic activities. Nitrate and chloride have been identified as the most common pollutants. These pollutants are attributed to the chlorination of wells and leaching from pit latrines and refuse dumps. The stable isotopic compositions in the investigated water sources suggest evidence of evaporation before recharge. Four major groups of waters were identified by salinity and NO3 concentrations using the Q-mode hierarchical cluster analysis (HCA). Consistent with the isotopic results, group 1 represents fresh unpolluted water occurring near the recharge zone in the general flow regime; groups 2 and 3 are mixed water whose composition is controlled by both weathering of rock-forming minerals and anthropogenic activities; group 4 represents water under high vulnerability of anthropogenic pollution. Moreover, the isotopic results and the HCA showed that the CO2-rich bottom water of LM belongs to an isolated hydrological system within the Foumbot plain. Except for some springs, groundwater water in the area is inappropriate for drinking and domestic purposes but good to excellent for irrigation.

  8. Determination of picloram in natural waters employing sequential injection square wave voltammetry using the hanging mercury drop electrode.

    Science.gov (United States)

    Dos Santos, Luciana B O; Masini, Jorge C

    2007-05-15

    This paper describes the development of a sequential injection analysis method to automate the determination of picloram by square wave voltammetry exploiting the concept of monosegmented flow analysis to perform in-line sample conditioning and standard addition. To perform these tasks, an 800muL monosegment is formed, composed by 400muL of sample and 400muL of conditioning/standard solution, in medium of 0.10molL(-1) H(2)SO(4). Homogenization of the monosegment is achieved by three flow reversals. After homogenization the mixture zone is injected toward the flow cell, which is adapted to the capillary of a hanging drop mercury electrode, at a flow rate of 50muLs(-1). After a suitable delay time, the potential is scanned from -0.5 to -1.0V versus Ag/AgCl at frequency of 300Hz and pulse height of 25mV. The linear dynamic range is observed for picloram concentrations between 0.10 and 2.50mgL(-1) fitting to the linear equation I(p)=(-2.19+/-0.03)C(picloram)+(0.096+/-0.039), with R(2)=0.9996, for which the slope is given in muALmg(-1). The detection and quantification limits are 0.036 and 0.12mgL(-1), respectively. The sampling frequency is 37h(-1) when the standard addition protocol is followed, but can be increased to 41h(-1) if the protocol to obtain in-line external calibration curve is used for quantification. The method was applied for determination of picloram in spiked water samples and the accuracy was evaluated by comparison with high performance liquid chromatography using molecular absorption at 220nm for detection. No evidences of statistically significant differences between the two methods were observed.

  9. Stable isotope (δ18O and δ2H) data for precipitation, stream water, and groundwater in Puerto Rico

    Science.gov (United States)

    Scholl, Martha A.; Torres-Sanchez, Angel; Rosario-Torres, Manuel

    2014-01-01

    Puerto Rico is located in the northeastern Caribbean Sea (18.2 °N, 66.3 °W), with the Atlantic Ocean on its northern coast. The U.S. Geological Survey’s Water, Energy, and Biogeochemical Budgets (WEBB) program study area in which most of these data were collected comprises the El Yunque National Forest and surrounding area of eastern Puerto Rico. Samples were collected in two forested watersheds, the Rio Mameyes and the Rio Icacos/Rio Blanco, on opposite sides of a ridge in the Luquillo Mountains on the eastern end of the island (fig. 1). Elevation in both watersheds ranges from sea level to approximately 1,000 meters (m). Near sea level, land use is mixed pasture, moist forest, and residential, grading to completely forested within the boundaries of El Yunque National Forest. Forest type changes with elevation from tabonuco to palo colorado to sierra palm to cloud forest above approximately 950 m (Murphy and others, 2012). The Rio Mameyes watershed is oriented north-northeast, and the basin is underlain by volcaniclastic bedrock (basaltic to andesitic volcanic sandstone/mudstone/conglomerate/breccia). The Rio Icacos/Rio Blanco watershed is oriented south-southeast. The Rio Icacos is one of the headwaters of the Rio Blanco and is underlain by quartz diorite. The lower Rio Blanco basin is underlain by andesitic volcaniclastic bedrock. This report also contains a long-term rain isotope dataset from the San Agustin site, in north-central Puerto Rico (fig. 1). Puerto Rico has a tropical climate dominated by easterly trade winds, and seasonal climate patterns affect the hydrology of the study area. The summer wet season is characterized by convective precipitation from tropical easterly waves, troughs, and cyclonic low-pressure systems, including tropical storms and hurricanes; in contrast, the drier winter season is characterized by trade-wind showers and frontal systems. The highest single-event rainfall totals tend to be associated with tropical storms

  10. Comparison of field-enhanced and pressure-assisted field-enhanced sample injection techniques for the analysis of water-soluble vitamins using CZE.

    Science.gov (United States)

    Liu, Qingqing; Liu, Yaling; Guan, Yu; Jia, Li

    2009-04-01

    A new online concentration method, namely pressure-assisted field-enhanced sample injection (PA-FESI), was developed and compared with FESI for the analysis of water-soluble vitamins by CZE with UV detection. In PA-FESI, negative voltage and positive pressure were simultaneously applied to initialize PA-FESI. PA-FESI uses the hydrodynamic flow generated by the positive pressure to counterbalance the reverse EOF in the capillary column during electrokinetic sample injection, which allowed a longer injection time than usual FESI mode without compromising the separation efficiency. Using the PA-FESI method, the LODs of the vitamins were at ng/mL level based on the S/N of 3 and the RSDs of migration time and peak area for each vitamin (1 microg/mL) were less than 5.1%. The developed method was applied to the analysis of water-soluble vitamins in corns.

  11. Tracing and quantifying lake water and groundwater fluxes in the area under mining dewatering pressure using coupled O and H stable isotope approach.

    Science.gov (United States)

    Lewicka-Szczebak, Dominika; Jędrysek, Mariusz-Orion

    2013-01-01

    Oxygen and hydrogen stable isotopic compositions of precipitation, lake water and groundwater were used to quantitatively asses the water budget related to water inflow and water loss in natural lakes, and mixing between lake water and aquifer groundwater in a mining area of the Lignite Mine Konin, central Poland. While the isotopic composition of precipitation showed large seasonal variations (δ(2)H from-140 to+13 ‰ and δ(18)O from-19.3 to+7.6 ‰), the lake waters were variously affected by evaporation (δ(2)H from-44 to-21 ‰ and δ(18)O from-5.2 to-1.7 ‰) and the groundwater showed varying contribution from mixing with surface water (δ(2)H from-75 to-39 ‰ and δ(18)O from-10.4 to-4.8 ‰). The lake water budget was estimated using a Craig-Gordon model and isotopic mass balance constraint, which enabled us to identify various water sources and to quantify inflow and outflow for each lake. Moreover, we documented that a variable recharge of lake water into the Tertiary aquifer was dependent on mining drainage intensity. A comparison of coupled δ(2)H-δ(18)O data with hydrogeological results indicated better precision of the δ(2)H-based calculations.

  12. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  13. Development and Validation of a Fast Procedure to Analyze Amoxicillin in River Waters by Direct-Injection LC-MS/MS

    Science.gov (United States)

    Homem, Vera; Alves, Arminda; Santos, Lu´cia

    2014-01-01

    A laboratory application with a strong component in analytical chemistry was designed for undergraduate students, in order to introduce a current problem in the environmental science field, the water contamination by antibiotics. Therefore, a simple and rapid method based on direct injection and high performance liquid chromatography-tandem mass…

  14. Stable, Long-Term, Spatial Memory in Young and Aged Rats Achieved with a One Day Morris Water Maze Training Protocol

    Science.gov (United States)

    Barrientos, Ruth M.; Kitt, Meagan M.; D'Angelo, Heather M.; Watkins, Linda R.; Rudy, Jerry W.; Maier, Steven F.

    2016-01-01

    Here, we present data demonstrating that a 1 d Morris water maze training protocol is effective at producing stable, long-term spatial memory in both young (3 mo old) and aged (24 mo old) F344xBN rats. Four trials in each of four sessions separated by a 2.5 h ISI produced robust selective search for the platform 1 and 4 d after training, in both…

  15. Development and Validation of a Fast Procedure To Analyze Amoxicillin in River Waters by Direct-Injection LC-MS/MS

    OpenAIRE

    Vera Homem; Arminda Alves; Lúcia Silveira Santos

    2014-01-01

    A laboratory application with a strong component in analytical chemistry was designed for undergraduate students, in order to introduce a current problem in the environmental science field, the water contamination by antibiotics. Therefore, a simple and rapid method based on direct injection and high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and optimized for the determination of amoxicillin in river water. Students learned the main optimization steps...

  16. External and Intraparticle Diffusion of Coumarin 102 with Surfactant in the ODS-silica Gel/water System by Single Microparticle Injection and Confocal Fluorescence Microspectroscopy

    OpenAIRE

    NAKATANI, Kiyoharu; MATSUTA, Emi

    2015-01-01

    The release mechanism of coumarin 102 from a single ODS-silica gel microparticle into the water phase in the presence of Triton X-100 was investigated by confocal fluorescence microspectroscopy combined with the single microparticle injection technique. The release rate significantly depended on the Triton X-100 concentration in the water phase and was not limited by diffusion in the pores of the microparticle. The release rate constant was inversely proportional to the microparticle radius s...

  17. Tracing stable isotopes (δ²H and δ¹⁸O) from meteoric water to groundwater in the Densu River basin of Ghana.

    Science.gov (United States)

    Adomako, Dickson; Gibrilla, Abass; Maloszewski, Piotr; Ganyaglo, Samuel Yao; Rai, Shive Prakash

    2015-05-01

    This study represents the first attempt to study soil water δ(18)O profiles in Ghana using a mechanical auger. In this paper, the characteristics of δ(18)O and δ(2)H in rain water, surface water, soil water and groundwater have been used to understand the transformation mechanism of rain water to groundwater. Rain waters were sampled in Koforidua and Accra. Surface water and groundwater were sampled from the Densu River and selected boreholes in the basin, respectively. Soil waters were taken from three typical sites, namely, Potroase (POT), Teacher Mante (TM) and Ayikai Doblo (AD) in the northern, middle and southern zone from 0.00- to 6-m depth. The soil water was extracted using vacuum distillation method. The distribution of the stable isotopes of rain water is influenced by rainfall amount with minimal temperature effect. In general, the soil water is of meteoric origin undergoing fractionation-controlled evaporation. In the middle zone, the soil water shows some evidence of recharge from enriched source. The three profiles show similar trend of enriched values in the upper depths with gradual depletions of δ(18)O with depth. The POT profile showed relatively more depleted values suggesting a fast infiltration. In all the three profiles, soil waters below 3 m were found to contribute to groundwater recharge with piston flow as the dominant mechanism. The study also revealed that there is a significant contribution of enrich source to the groundwater system leading to the dilution of the infiltrating water by the large aquifer.

  18. Advancement of In-Flight Alumina Powder Spheroidization Process with Water Droplet Injection Using a Small Power DC-RF Hybrid Plasma Flow System

    Science.gov (United States)

    Jang, Juyong; Takana, Hidemasa; Park, Sangkyu; Nishiyama, Hideya

    2012-09-01

    The correlation between plasma thermofluid characteristics and alumina powder spheroidization processes with water droplet injection using a small power DC-RF hybrid plasma flow system was experimentally clarified. Micro-sized water droplets with a low water flow rate were injected into the tail of thermal plasma flow so as not to disturb the plasma flow directly. Injected water droplets were vaporized in the thermal plasma flow and were transported upstream in the plasma flow to the torch by the backflow. After dissociation of water, the production of hydrogen was detected by the optical emission spectroscopy in the downstream RF plasma flow. The emission area of the DC plasma jet expanded and elongated in the vicinity of the RF coils. Additionally, the emission area of RF plasma flow enlarged and was visible as red emission in the downstream RF plasma flow in the vicinity below the RF coils due to hydrogen production. Therefore, the plasma flow mixed with produced hydrogen increased the plasma enthalpy and the highest spheroidization rate of 97% was obtained at a water flow rate of 15 Sm l/min and an atomizing gas flow rate of 8 S l/min using a small power DC-RF hybrid plasma flow system.

  19. Model experiment on change of seismic properties of a fracture caused by injecting/draining water; Chusui/haisui ni yoru kison kiretsu no dansei denpa tokusei no henka ni kansuru model jikken

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T; Koizumi, T; Sassa, K [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1997-05-27

    Effect of water injection/draining on elastic waves penetrating through cracks is examined by measuring elastic waves before, during, and after the injection/draining of water into/from cracks in presence in granite. Two blocks of rock, with their crack-containing surfaces in contact with each other, are placed in a vessel, and water injection/draining is done through a hole on a vessel bottom side so that water will penetrate into the cracks. When the blocks are dry, there is almost no contact between the cracks, and so no crack penetrating waves are observed. Crack penetrating waves are produced when water is injected, and the position of the receiver sensing the penetrating waves changes as the water level rises. When the water level is lowered from the high water level, the waveform changes again as the level changes. The change in waveform is not so remarkable, however, as that observed during water injection thanks to the water residual in the cracks. It is now inferred that crack investigation is more effective when it is carried out with water being injected into dry cracks. The difference produced between the dry state and wet state when water is injected into dry cracks is used to detect the presence of cracks in this experiment, and this may be applied also to the investigation of cracks in the shallow part of the ground. 4 refs., 11 figs.

  20. Sources, migration and transformation of antimony contamination in the water environment of Xikuangshan, China: Evidence from geochemical and stable isotope (S, Sr) signatures

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Bing [Geological Survey, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China); State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China); Zhou, Jianwei, E-mail: jw.zhou@cug.edu.cn [School of Environmental Studies, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China); Zhou, Aiguo; Liu, Cunfu [School of Environmental Studies, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China); Xie, Lina [School of Environmental Studies, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China); State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Lumo Rd 388, Wuhan 430074, Hubei (China)

    2016-11-01

    The Xikuangshan (XKS) mine in central China is the largest antimony (Sb) mine in the world. The mining activity has seriously contaminated the waters in the area. To determine the sources, migration and transformation of Sb contamination, 32 samples from groundwater (aquifer water), surface water and mine water were collected for water chemistry, trace element and S{sub SO4} and Sr stable isotope analyses. The results showed that the groundwater and surface water were in an oxidized environment. The S{sub SO4} and Sr isotope compositions in the water indicated that dissolved Sb and SO{sub 4}{sup 2} originated from sulfide mineral (Sb{sub 2}S{sub 3}) oxidation, whereas radiogenic Sr may have been sourced from silicified limestone and stibnite in the Shetianqiao aquifer. Furthermore, a positive correlation between δ{sup 34}S{sub SO4} and δ{sup 87}Sr values revealed that the Sr, S and Sb in the waters had a common contamination source, i.e., silicified limestone and stibnite, whereas the Sr, S and Sb in rock and ore were sourced from Proterozoic basement clastics. The analysis also indicated that the isotope composition of dissolved SO{sub 4}{sup 2} {sup −} had been influenced by slight bacterial SO{sub 4} reduction in the Magunao aquifer. Mining or rock collapse may have caused Shetianqiao aquifer water to contaminate the Magunao aquifer water via mixing. This study has demonstrated that the stable isotopes of {sup 34}S{sub SO4} and {sup 87}Sr, combined with hydrochemical methods, are effective in tracking the sources, migration and transformation of Sb contamination. - Highlights: • Mining activities at XKS mine have caused serious water contamination. • The characteristics of Sb contamination in water environment are still unclear. • Combine S isotopes of sulfate and Sr isotopes with hydrochemical methods. • Sr, S, and Sb in natural water had a common source: silicified limestone and stibnite. • Shetianqiao aquifer water contaminated the Magunao

  1. Testosterone Injection

    Science.gov (United States)

    ... typical male characteristics. Testosterone injection works by supplying synthetic testosterone to replace the testosterone that is normally ... as a pellet to be injected under the skin.Testosterone injection may control your symptoms but will ...

  2. Using stable isotopes to assess surface water source dynamics and hydrological connectivity in a high-latitude wetland and permafrost influenced landscape

    Science.gov (United States)

    Ala-aho, P.; Soulsby, C.; Pokrovsky, O. S.; Kirpotin, S. N.; Karlsson, J.; Serikova, S.; Vorobyev, S. N.; Manasypov, R. M.; Loiko, S.; Tetzlaff, D.

    2018-01-01

    Climate change is expected to alter hydrological and biogeochemical processes in high-latitude inland waters. A critical question for understanding contemporary and future responses to environmental change is how the spatio-temporal dynamics of runoff generation processes will be affected. We sampled stable water isotopes in soils, lakes and rivers on an unprecedented spatio-temporal scale along a 1700 km transect over three years in the Western Siberia Lowlands. Our findings suggest that snowmelt mixes with, and displaces, large volumes of water stored in the organic soils and lakes to generate runoff during the thaw season. Furthermore, we saw a persistent hydrological connection between water bodies and the landscape across permafrost regions. Our findings help to bridge the understanding between small and large scale hydrological studies in high-latitude systems. These isotope data provide a means to conceptualise hydrological connectivity in permafrost and wetland influenced regions, which is needed for an improved understanding of future biogeochemical changes.

  3. A Methodology for the Optimization of Flow Rate Injection to Looped Water Distribution Networks through Multiple Pumping Stations

    Directory of Open Access Journals (Sweden)

    Christian León-Celi

    2016-12-01

    Full Text Available The optimal function of a water distribution network is reached when the consumer demands are satisfied using the lowest quantity of energy, maintaining the minimal pressure required at the same time. One way to achieve this is through optimization of flow rate injection based on the use of the setpoint curve concept. In order to obtain that, a methodology is proposed. It allows for the assessment of the flow rate and pressure head that each pumping station has to provide for the proper functioning of the network while the minimum power consumption is kept. The methodology can be addressed in two ways: the discrete method and the continuous method. In the first method, a finite set of combinations is evaluated between pumping stations. In the continuous method, the search for the optimal solution is performed using optimization algorithms. In this paper, Hooke–Jeeves and Nelder–Mead algorithms are used. Both the hydraulics and the objective function used by the optimization are solved through EPANET and its Toolkit. Two case studies are evaluated, and the results of the application of the different methods are discussed.

  4. Differential soil water sourcing of managed Loblolly Pine and Sweet Gum revealed by stable isotopes in the Upper Coastal Plain, USA

    Science.gov (United States)

    Brockman, L. E.; Younger, S. E.; Jackson, C. R.; McDonnell, J.; Janzen, K. F.

    2017-12-01

    Stable isotope signatures of stem water can illuminate where in the soil profile different types of trees are accessing soil water and thereby contribute to our understanding of water movement through the soil plant atmosphere continuum. The objective of this study was to use 2H and 18O isotopes to characterize water sources of fourteen-year-old intensively managed Loblolly Pine and Sweet Gum stands in replicated (n=3) paired plots. In order to differentiate the isotopic signatures of tree and soil water, both species and five soil depths were sampled monthly for one year. Tree sap and soil water were extracted cryogenically and their isotopic signatures were determined. Although plant water uptake is generally considered a non-fractionating process, our dataset suggests a source of fractionation in 2H signatures in both species and during most of the thirteen sampling events. As a result, only the 18O isotopic data were used to determine the vertical distribution of soil water contributions to stem water. Statistically, we grouped the five soil sampling depths into three isotopic horizons. Shallow, intermediate and deep soil represent sampling depths of 0-10cm, 30-70cm and 100-125cm, respectively. These isotopic horizons were used in a direct inference approach and Bayesian mixing model analysis to determine the origin of stem water. In this study, Loblolly Pine used more water from intermediate and deep soil while Sweet Gum used more water from shallow and intermediate soil. In the winter months, January through March, Loblolly Pine transpired primarily deep soil where as Sweet Gum mainly utilized shallow soil for transpiration. These results indicate that both species have opportunistic water use patterns with seasonal variation.

  5. Water-to-fish transfer of stable elements in near-coastal seas around a nuclear site of Korea

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Y.H.; Lim, K.M.; Jun, I.; Kim, B.H.; Keum, D.K. [Korea Atomic Energy Research Institute (Korea, Republic of)

    2014-07-01

    In radiation dose assessment models for wildlife, the transfer of radionuclides to plant and animal species is usually quantified with concentration ratios (CRs) between them and environmental media. The IAEA recently produced a handbook of CR values covering various radionuclides and many kinds of plant and animal species. However, CR values can vary considerably with wildlife species and environmental conditions. Therefore, it is desirable to use as many site-specific CR data as possible. In the present study, the CR values of various stable elements as surrogates for radionuclides were investigated for several marine fish species inhabiting near-coastal seas around a nuclear power plant site of Korea. In May to June, 2012, fish and seawater samples were collected from six points in the sea within 10 km from Wolsung NPP site. For seawater samples, temperature, pH and salinity were measured immediately after collected. Fish samples were put in an icebox and carried to the laboratory, where they were freeze-dried and homogenized for the whole bodies using a grinder. Aliquots of the homogenized samples were changed into liquid samples as a result of chemical treatments. Sea water samples were filtered using a membrane filter (0.2 μm in pore size). Elemental concentrations were measured with the prepared liquid samples using the ICP-MS and ICP-AES. The CR value (L/kg-fresh) was expressed as the ratio of the fish concentration (Bq/kg-fresh) to the seawater concentration (Bq/L). The numbers of the elements and fish species investigated were 21 and 14, respectively. The CR values of Na and Mg were lower than 1 for all the fish species, whereas those of the remaining elements were always higher than 1 except for Li and U. Zn, Mn, Al and Fe formed a group of the highest CR values in general and their CR values mostly ranged from hundreds to thousands. In the case of Zn, CR values even higher than ten thousands were observed for seven species including greenling, sea bass

  6. Water-free transfer method for CVD-grown graphene and its application to flexible air-stable graphene transistors.

    Science.gov (United States)

    Kim, Hyun Ho; Chung, Yoonyoung; Lee, Eunho; Lee, Seong Kyu; Cho, Kilwon

    2014-05-28

    Transferring graphene without water enables water-sensitive substrates to be used in graphene electronics. A polymeric bilayer (PMMA/PBU) is coated on graphene as a supporting layer for the water-free transfer process and as an excellent passivation layer that enhances device operation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Connecting long term species changes and their water competitions in temperate forest Mt. Baegun, Rep. of Korea using hydrogen and oxygen stable isotope analysis

    Science.gov (United States)

    Jeon, J.; Lee, H.; Lee, M.; Song, W.; Byeon, S.; Lee, B.; Cho, S.; Park, J.; Kim, H. S.

    2017-12-01

    Many dynamic vegetation model simulations have predicted dramatic changes in species composition of temperate forests due to climate changes and successional reasons. Especially, conifer species are expected to lose their habitats and to be replaced by broadleaf species. Similarly, our more than 15-years-long 880 permenant plots tree survey data in Mt. Baegun, Rep. of Korea, showed substantial decrease of conifer species and their productivities and increase of broadleaved species. One of main reasons for these changes in species could be attributed to the water competition among tree species in the same stand. Therefore, we investigated the differences in water uptake scheme between conifer and broadleaf species from the temperate forests of Korea using stable isotopes. Six study plots showing high competition (conifers vs. broadleaf species) based on previous vegetation survey were chosen and the species-specific water uptake depth was estimated by measuring hydrogen(δ2H) and oxygen(δ18O) ratio from the xylem sap and leaves of individual species and by comparing them with those of soil water from 5 depths, (10, 30, 50, 100 and 120 cm), which extracted by lysimeter. The collection was conducted from April 2016 to Nov 2017. The conifer species included Pinus densiflora and Chamaecyparis obtusa vs. broadleaved species included Carpinus laxiflora, Prunus sargentii, Styrax obassia, Lindera erythrocarpa and Quercus species such as Q. mongolica, Q. serrata, Q. accuticima. Preliminary results showed the stable isotope signatures of soil water was increased from 10 cm to 30 cm, and then decreased gradually until 120 cm. In addition, current dominant canopy species, Chamaecyparis obtusa absorbed majority of their water from 10 to 30 cm depth. In comparison, current mid canopy but one of upcoming dominant species, Styrax obassia's major water source was 30 cm and deeper of soil. Our results could be essential for the prediction of species composition under climate change

  8. Rapid colorimetric assay for gentamicin injection.

    Science.gov (United States)

    Tarbutton, P

    1987-01-01

    A rapid colorimetric method for determining gentamicin concentration in commercial preparations of gentamicin sulfate injection was developed. Methods currently available for measuring gentamicin concentration via its colored complex with cupric ions in alkaline solution were modified to reduce the time required for a single analysis. The alkaline copper tartrate (ACT) reagent solution was prepared such that each milliliter contained 100 mumol cupric sulfate, 210 mumol potassium sodium tartrate, and 1.25 mmol sodium hydroxide. The assay involves mixing 0.3 mL gentamicin sulfate injection 40 mg/mL (of gentamicin), 1.0 mL ACT reagent, and 0.7 mL water; the absorbance of the resulting solution at 560 nm was used to calculate the gentamicin concentration in the sample. For injections containing 10 mg/mL of gentamicin, the amount of the injection was increased to 0.5 mL and water decreased to 0.5 mL. The concentration of gentamicin in samples representing 11 lots of gentamicin sulfate injection 40 mg/mL and 8 lots of gentamicin sulfate injection 10 mg/mL was determined. The specificity, reproducibility, and accuracy of the assay were assessed. The colored complex was stable for at least two hours. Gentamicin concentration ranged from 93.7 to 108% and from 95 to 109% of the stated label value of the 40 mg/mL and the 10 mg/mL injections, respectively. No components of the preservative system present in the injections interfered with the assay. Since other aminoglycosides produced a colored complex, the assay is not specific for gentamicin. The assay was accurate and reproducible over the range of 4-20 mg of gentamicin. This rapid and accurate assay can be easily applied in the hospital pharmacy setting.

  9. Stable carbon isotope composition (δ{sup 13}C), water use efficiency, and biomass productivity of Lycopersicon esculentum, Lycopersicon pennellii, and the F{sub 1} hybrid

    Energy Technology Data Exchange (ETDEWEB)

    Martin, B.; Thorstenson, Y. R.

    1988-09-01

    Three tomatoes, Lycopersicon esculentum Mill. cv UC82B, a droughttolerant wild related species, Lycopersicon pennellii (Cor.) D'Arcy, and their F{sub 1}, hybrid, were grown in containers maintained at three levels of soil moisture. Season-long water use was obtained by summing over the season daily weight losses of each container corrected for soil evaporation. Plant biomass was determined by harvesting and weighing entire dried plants. Season-long water use efficiency (gram dry weight/kilogram H{sub 2}O) was calculated by dividing the dry biomass by the season-long water use. The season-long water use efficiency was greatest in the wild parent, poorest in the domestic parent, and intermediate (but closer to the wild parent) in the F, hybrid. Instantaneous water-use efficiency (micromole CO{sub 2}/millimole H{sub 2}O) determined by gas exchange measurements on individual leaves was poorly correlated with season-long water use efficiency. However, the relative abundance of stable carbon isotopes of leaf tissue samples was strongly correlated with the season-long water use efficiency. Also, the isotopic composition and the season-long water use efficiency of each genotype alone were strongly negatively correlated with plant dry weight when the dry weight varied as a function of soil moisture. (author)

  10. A new high-quality set of singly (H-2) and doubly (H-2 and O-18) stable isotope labeled reference waters for biomedical and other isotope-labeled research

    NARCIS (Netherlands)

    Faghihi, V.; Verstappen-Dumoulin, B. M. A. A.; Jansen, H. G.; van Dijk, G.; Aerts-Bijma, A. T.; Kerstel, E. R. T.; Groening, M.; Meijer, H. A. J.

    2015-01-01

    RATIONALE: Research using water with enriched levels of the rare stable isotopes of hydrogen and/or oxygen requires well-characterized enriched reference waters. The International Atomic Energy Agency (IAEA) did have such reference waters available, but these are now exhausted. New reference waters

  11. The Influence of CO2 Solubility in Brine on Simulation of CO2 Injection into Water Flooded Reservoir and CO2 WAG

    DEFF Research Database (Denmark)

    Yan, Wei; Stenby, Erling Halfdan

    2010-01-01

    Injection of CO2 into depleted oil reservoirs is not only a traditional way to enhance oil recovery but also a relatively cheaper way to sequester CO2 underground since the increased oil production can offset some sequestration cost. CO2 injection process is often applied to water flooded...... simulations were made for seven oil samples within a wide range of temperature, pressure and salinity. The results were analyzed in terms of the change in oil recovery due to different phase equilibrium descriptions, the delay in breakthrough and the CO2 lost to the aqueous phase. The influence of different...

  12. Stable oxygen isotope and flux partitioning demonstrates understory of an oak savanna contributes up to half of ecosystem carbon and water exchange

    Directory of Open Access Journals (Sweden)

    Maren eDubbert

    2014-10-01

    Full Text Available Semi-arid ecosystems contribute about 40% to global net primary production (GPP even though water is a major factor limiting carbon uptake. Evapotranspiration (ET accounts for up to 95% of the water loss and in addition, vegetation can also mitigate drought effects by altering soil water distribution. Hence, partitioning of carbon and water fluxes between the soil and vegetation components is crucial to gain mechanistic understanding of vegetation effects on carbon and water cycling. However, the possible impact of herbaceous vegetation in savanna type ecosystems is often overlooked. Therefore, we aimed at quantifying understory vegetation effects on the water balance and productivity of a Mediterranean oak savanna. ET and net ecosystem CO2 exchange (NEE were partitioned based on flux and stable oxygen isotope measurements and also rain infiltration was estimated.The understory vegetation contributed importantly to total ecosystem ET and GPP with a maximum of 43% and 51%, respectively. It reached water-use efficiencies (WUE; ratio of carbon gain by water loss similar to cork-oak trees. The understory vegetation inhibited soil evaporation (E and, although E was large during wet periods, it did not diminish WUE during water-limited times. The understory strongly increased soil water infiltration, specifically following major rain events. At the same time, the understory itself was vulnerable to drought, which led to an earlier senescence of the understory growing under trees as compared to open areas, due to competition for water. Thus, beneficial understory effects are dominant and contribute to the resilience of this ecosystem. At the same time the vulnerability of the understory to drought suggests that future climate change scenarios for the Mediterranean basin threaten understory development. This in turn will very likely diminish beneficial understory effects like infiltration and ground water recharge and therefore ecosystem resilience to

  13. Coolant Mixing in a Pressurized Water Reactor: Deboration Transients, Steam-Line Breaks, and Emergency Core Cooling Injection

    International Nuclear Information System (INIS)

    Prasser, Horst-Michael; Grunwald, Gerhard; Hoehne, Thomas; Kliem, Soeren; Rohde, Ulrich; Weiss, Frank-Peter

    2003-01-01

    emergency core cooling (ECC) water entering the RPV through the ECC injection into the cold leg. The experimental results show an incomplete mixing with typical concentration and temperature distributions at the core inlet, which strongly depend on the boundary conditions. Computational fluid dynamics calculations were found to be in good agreement with the experiments

  14. External and Intraparticle Diffusion of Coumarin 102 with Surfactant in the ODS-silica Gel/water System by Single Microparticle Injection and Confocal Fluorescence Microspectroscopy.

    Science.gov (United States)

    Nakatani, Kiyoharu; Matsuta, Emi

    2015-01-01

    The release mechanism of coumarin 102 from a single ODS-silica gel microparticle into the water phase in the presence of Triton X-100 was investigated by confocal fluorescence microspectroscopy combined with the single microparticle injection technique. The release rate significantly depended on the Triton X-100 concentration in the water phase and was not limited by diffusion in the pores of the microparticle. The release rate constant was inversely proportional to the microparticle radius squared, indicating that the rate-determining step is the external diffusion between the microparticle and the water phase.

  15. External and intraparticle diffusion of coumarin 102 with surfactant in the ODS-silica gel/water system by single microparticle injection and confocal fluorescence microspectroscopy

    International Nuclear Information System (INIS)

    Nakatani, Kiyoharu; Matsuta, Emi

    2015-01-01

    The release mechanism of coumarin 102 from a single ODS-silica gel microparticle into the water phase in the presence of Triton X-100 was investigated by confocal fluorescence microspectroscopy combined with the single microparticle injection technique. The release rate significantly depended on the Triton X-100 concentration in the water phase and was not limited by diffusion in the pores of the microparticle. The release rate constant was inversely proportional to the microparticle radius squared, indicating that the rate-determining step is the external diffusion between the microparticle and the water phase. (author)

  16. Profiles of chloride and water stable isotope in porewater obtained from a 2000 m-deep borehole through the Mesozoic sedimentary series in the East of France

    International Nuclear Information System (INIS)

    Bensenouci, F.; Michelot, J.L.; Matray, J.M.; Savoye, S.

    2010-01-01

    Document available in extended abstract form only. A method to obtain information about fluid flow and solute transport in porous media with low hydraulic conductivity and low water content is based on the study of the natural tracer distribution in pore water. This approach was previously applied to the Callovo-Oxfordian argillites, studied by Andra at the Bure URL (East of France), using several natural tracer profiles ( 4 He, 2 H, 18 O, Cl - , 37 Cl). These profiles were interpreted as the result of a diffusive exchange between pore water in the aquitard and groundwater in the surrounding aquifers. Howe