WorldWideScience

Sample records for reservoir wetting conditions

  1. Effect of Temperature on Wettability and Optimum Wetting Conditions for Maximum Oil Recovery in Carbonate Reservoir System

    DEFF Research Database (Denmark)

    Sohal, Muhammad Adeel Nassar; Thyne, Geoffrey; Søgaard, Erik Gydesen

    2017-01-01

    , lithology, pH, oil acid and base numbers to improve water wetting has been tested in recovery experiments. In these studies temperature is mainly investigated to observe the reactivity of potential anions (SO42-, PO33-, and BO33-) at different concentrations. But the influence of systematically increasing...

  2. Modeling of wettability alteration during spontaneous imbibition of mutually soluble solvents in mixed wet fractured reservoirs

    NARCIS (Netherlands)

    Chahardowli, M.; Bruining, J.

    2014-01-01

    Mutually-soluble solvents can enhance oil recovery both in mixed-wet fractured reservoirs. When a partially waterwet matrix is surrounded by an immiscible wetting phase in the fracture, spontaneous imbibition is the most important production mechanism. Initially, the solvent moves with the imbibing

  3. Wet microcontact printing (µCP) for micro-reservoir drug delivery systems

    International Nuclear Information System (INIS)

    Lee, Hong-Pyo; Ryu, WonHyoung

    2013-01-01

    When micro-reservoir-type drug delivery systems are fabricated, loading solid drugs in drug reservoirs at microscale is often a non-trivial task. This paper presents a simple and effective solution to load a small amount of drug solution at microscale using ‘wet’ microcontact printing (µCP). In this wet µCP, a liquid solution containing drug molecules (methylene blue and tetracycline HCl) dissolved in a carrier solvent was transferred to a target surface (drug reservoir) by contact printing process. In particular, we have investigated the dependence of the quantity and morphology of transferred drug molecules on the stamp size, concentration, printing times, solvent types and surfactant concentration. It was also found that the repetition of printing using a non-volatile solvent such as polyethylene glycol (PEG) as a drug carrier material actually increased the transferred amount of drug molecules in proportion to the printing times based on asymmetric liquid bridge formation. Utilizing this wet µCP, drug delivery devices containing different quantity of drugs in micro-reservoirs were fabricated and their performance as controlled drug delivery devices was demonstrated. (paper)

  4. Aerodynamic force coefficients of plain bridge cables in wet conditions

    DEFF Research Database (Denmark)

    Matteoni, Giulia; Georgakis, Christos T.

    In this paper, the aerodynamic forces and force coefficients from preliminary static wind tunnel tests on a plain cable in wet conditions are presented. The presented results are for several different relative cable wind-angles. A comparison is made with tests in dry conditions. In dry conditions...

  5. Water Age Responses to Weather Conditions in a Hyper-Eutrophic Channel Reservoir in Southern China

    Directory of Open Access Journals (Sweden)

    Wei Du

    2016-08-01

    Full Text Available Channel reservoirs have the characteristics of both rivers and lakes, in which hydrodynamic conditions and the factors affecting the eutrophication process are complex and highly affected by weather conditions. Water age at any location in the reservoir is used as an indicator for describing the spatial and temporal variations of water exchange and nutrient transport. The hyper-eutrophic Changtan Reservoir (CTR in Southern China was investigated. Three weather conditions including wet, normal, and dry years were considered for assessing the response of water age by using the coupled watershed model Soil Water Assessment Tool (SWAT and the three-dimensional hydrodynamic model Environmental Fluid Hydrodynamic Code (EFDC. The results showed that the water age in CTR varied tremendously under different weather conditions. The averaged water ages at the downstream of CTR were 3 d, 60 d, and 110 d, respectively in the three typical wet, normal, and dry years. The highest water ages at the main tributary were >70 d, >100 d, and >200 d, respectively. The spatial distribution of water ages in the tributaries and the reservoir were mainly affected by precipitation. This paper provides useful information on water exchange and transport pathways in channel reservoir, which will be helpful in understanding nutrient dynamics for controlling algal blooms.

  6. Microclimate conditions in ventilated wet-walled greenhouses in a ...

    African Journals Online (AJOL)

    Spatial variations of microclimatic conditions in enclosed north–south (N–S) oriented single-arched greenhouse polycarbonate structures, with a wet-wall providing evaporative cooling at the S end, were investigated and displayed online in near real-time. Temperature-controlled fans at the N end extracted air.

  7. Sustainable Irrigation Allocation Model for Dry and Wet Periods using Reservoir Storage and Inflow

    Science.gov (United States)

    Surianarayanan, S.; Suribabu, C. R.; Ramakrishnan, K.

    2017-07-01

    The dry period agriculture is inevitable both for the farmers for their earning, and for the soil for its fertility by crop-rotation. In tropical countries like INDIA, dry period agriculture becomes difficult because of less (or) no rain fall. Hence a simple water balancing model for irrigation scheduling, using the measure “Volumetric Reliability” is prepared in this paper, with the storage and inflow of a reservoir both for the dry and wet periods. The case-study is done for a reservoir in INDIA with thirty one years of hydrological data(from 1982 to 2012). The objective of this paper is to prepare a simple water balance model taking 10 days periods of demand and supply for ID crop(Irrigated Dry crop, ground nut) with usage of volumetric reliability concept for the periods of deficiency and adoption of less water requirement crops to reduce the water-stress during critical periods of crop growth, and finally arrive at a feasible allocation schedule for the success of agriculture and the yield throughout the year both for wet and dry crops with the available storage on the start of irrigation for a particular year. The reservoir is divided for storages such as full, deficient and critical storages. The starting storage for the dry period from January is used after adequate allocation for wet crops, the quantity for riparian rights and for drinking water, for the sustainability. By the water-balancing, the time-series for thirty one years, it is found that for twenty two years the demand for the ID crops is satisfied with the storage in the reservoir, and in the remaining years of deficient inflows, for three years (1986,1996,2004)the demand is managed by using the safe reliability factor for demand which can nullify the deficit in demand for the whole supply period. But it is genuine to assure that the reduction in the amount of water for each 10 days periods should not exceed the survival limit of the crop. Necessary soil-moisture must be ensured in the crop

  8. Atmospheric corrosion of copper under wet/dry cyclic conditions

    Energy Technology Data Exchange (ETDEWEB)

    EL-Mahdy, Gamal A. [Department of Metallurgical System Engineering, Yonsei University, 134-Shinchon-dong, Seodaemun-Ku, Seoul, 120-749 (Korea, Republic of)

    2005-06-01

    The polarization resistance of copper subjected to NaCl and an ammonium sulfate solution under wet/dry cycling conditions was monitored using an EIS impedance technique. The copper samples were exposed to 1 h of immersion using different solutions of pH, temperature and surface orientation and 7 h of drying. The copper plates corroded more substantially on the skyward side than those for a ground ward side. The degree of protection copper oxide provides decrease in an acidic medium (pH 4) more than in a neutral medium (pH 7). The corrosion rate of copper increases rapidly during the initial stages of exposure then decreases slowly and eventually attains the steady state during the last stages of exposure. The corrosion products were analyzed using X-ray diffraction. The corrosion mechanism for copper studied under wet/dry cyclic conditions was found to proceed under the dissolution-precipitation mechanism.

  9. Designing Yellow Intervals for Rainy and Wet Roadway Conditions

    Directory of Open Access Journals (Sweden)

    Huan Li

    2012-06-01

    Full Text Available The research presented in this paper quantifies and models the impact of wet pavement surface and rainy weather conditions on driver perception-reaction times (PRTs, deceleration levels, and traffic signal change interval durations. A total of 648 stop-run records were collected as part of the research effort for a 72 km/h (45 mi/h approach speed where participant drivers encountered a yellow indication initiation at different distances from the intersection. The participant drivers were randomly selected in different age groups (under 40 years old, 40 to 59 years old, and 60 years of age or older and genders (female and male. Using the gathered data, statistical models for driver PRT and deceleration levels were developed, considering roadway surface and environmental parameters, driver attributes (age and gender, roadway grade, approaching speed, and time and distance to the intersection at the onset of yellow. Inclement weather yellow timings were then developed and summarized in lookup tables as a function of different factors (driver age/gender, roadway grade, speed limit, precipitation level, and roadway surface condition to provide practical guidelines for the design of yellow signal timings in wet and rainy weather conditions. The results indicate that wet roadway surface conditions require a 5 percent increase in the change interval and that rainy conditions require a 10 percent or more increase in the duration of the change interval. These recommended change durations can also be integrated within the Vehicle Infrastructure Integration (VII initiative to provide customizable driver warnings prior to a transition to a red indication.

  10. Wetting of bituminized ion-exchangers under simulated repository conditions

    International Nuclear Information System (INIS)

    Aalto, H.; Valkiainen, M.

    2001-01-01

    According to the present plans the spent nuclear fuel from four Finnish nuclear power units will be transferred after interim storage to the final disposal site where it will be encapsulated and disposed of in a final repository constructed into the bedrock at a depth of 500 meters. Low and medium level waste generated at nuclear power plants will be finally disposed of in caverns constructed in the bedrock at the power plant site. The safety of the final disposal is based on a multibarrier concept and the degree of safety is estimated by using predictive models. The properties of the waste form are taken into account in the design of the repository construction. Bitumen has been chosen as an immobilisation agent for the wet wastes at Olkiluoto Power Plant, where two BWR units, TVO 1 and TVO 2, have separate bituminization facilities designed by Asea-Atom. Properties of bituminized spent ion-exchange resins from Olkiluoto power plant have been studied by VTT Chemical Technology since the late 70's. These studies have concentrated mainly on determining the long-term behaviour of the bituminization product under the repository conditions. Current interest lies on wetted product as a diffusion barrier. For this purpose a microscopic method for the visualisation of the structure of the wetted product has been developed. The equilibration of the samples in simulated concrete groundwater is currently going on at a temperature of 5-8 deg. C. Preliminary results are presented in this paper. Diffusion experiments have been planned for the further characterising of the wetted product as a release barrier for radionuclides including modelling. (author)

  11. Condition of research reactor spent nuclear fuels in wet storage

    International Nuclear Information System (INIS)

    Lambert, J.D.B.; Maksimkin, O.P.

    2004-01-01

    Full text: The condition of spent nuclear fuel (SNF) in wet storage at ten Soviet-designed research reactors has been assessed in the light of international experience in order to identify any associated safety issues. These reactors use Al-clad UO 2 -Al or U-Al alloy dispersion fuels of ≥20% enrichment that were fabricated in Russia; the reactors have been in operation since 1955-70. Although originally sent for reprocessing, much of the SNF generated over the last 25-30 years has been stored in fuel storage pools (FSPs) of variable water quality. The external condition of wet-stored SNF assemblies from the reactors surveyed varied from significant failure due to galvanic corrosion that was driven by poor water quality, through gradual pitting caused by slightly impure water, to a stable condition of no observable change in the oxidized Al alloy surface of the irradiated fuel. SNF stability in wet storage seems to depend on three factors: Al being the sole metal in the FSP (to avoid galvanic action); good water chemistry to suppress attack of the oxide layer by aggressive ions like Cl - , and gentle handling to limit physical damage to the oxide layer. If one of these factors is not satisfied, SNF degradation will take place; if more than one factor is not satisfied, failure of the Al cladding may occur. In general, however, even SNF failure in wet storage does not appear to raise significant safety concerns. A possible exception is where galvanic corrosion combined with poor water quality has caused massive fuel failure, as at the RA reactor in Belgrade. A potential safety problem was identified at reactors where unalloyed Al liners had been used in the FSPs. Unlike SNF that develops a protective oxide layer in-reactor, these Al liners were unprotected and prone to significant corrosion during an ill-defined early period of poor water quality. The risk of losing water from FSPs due to liner failure should be evaluated for all research reactors. Where the risk

  12. In situ characterization of mixed-wettability in a reservoir rock at subsurface conditions.

    Science.gov (United States)

    Alhammadi, Amer M; AlRatrout, Ahmed; Singh, Kamaljit; Bijeljic, Branko; Blunt, Martin J

    2017-09-07

    We used X-ray micro-tomography to image the in situ wettability, the distribution of contact angles, at the pore scale in calcite cores from a producing hydrocarbon reservoir at subsurface conditions. The contact angle was measured at hundreds of thousands of points for three samples after twenty pore volumes of brine flooding.We found a wide range of contact angles with values both above and below 90°. The hypothesized cause of wettability alteration by an adsorbed organic layer on surfaces contacted by crude oil after primary drainage was observed with Scanning Electron Microscopy (SEM) and identified using Energy Dispersive X-ray (EDX) analysis. However, not all oil-filled pores were altered towards oil-wet conditions, which suggests that water in surface roughness, or in adjacent micro-porosity, can protect the surface from a strong wettability alteration. The lowest oil recovery was observed for the most oil-wet sample, where the oil remained connected in thin sheet-like layers in the narrower regions of the pore space. The highest recovery was seen for the sample with an average contact angle close to 90°, with an intermediate recovery in a more water-wet system, where the oil was trapped in ganglia in the larger regions of the pore space.

  13. Ecological Aspects of Condition of Ground Deposits in Shershnevsky Reservoir

    Science.gov (United States)

    Arkanova, I. A.; Denisov, S. E.; Knutarev, D. Yu

    2017-11-01

    The article considers the aspects of the condition of ground deposits influencing the operating conditions of the water intake facilities in the Shershnevsky reservoir being the only source of the utility and drinking water supply in Chelyabinsk. The object of the research is a section near the Sosnovskie intake stations of the Shershnevsky reservoir. Based on the hydrometric surveys of the studied section and using the Kriging method and the Surfer suite, we calculated the volume of ground deposits. As a result of the analyses, the authors have proved that ground deposits in the studied section have a technology-related nature which is connected with the annual growth of the volume of ground deposits which is inadmissible in the operating conditions of the pump stations of water intake facilities whereas ground deposits will fully block the intake windows of pump stations. In case the bed area of the Shershnevsky reservoir is not timely treated, the ground deposits here will complicate the operation of the pump stations which will result in a technological problem of the treatment facilities operation up to a transfer of the pump station premises to other territories less exposed to the deposits. The treatment of the Shershnevsky reservoir from the ground deposits accumulated in the course of time will help to considerably increase its actual capacity, which will allow one to increase water circulation paths and to improve the water quality indices. In its turn, the water quality improvement will decrease the supply of suspended solids into the water intake facilities and cut the reagent costs in the course of the treatment water works operation.

  14. Effect of superhydrophobicity on flashover characteristics of silicone rubber under wet conditions

    OpenAIRE

    Yufeng Li; Haiyun Jin; Shichao Nie; Cheng Tong; Naikui Gao

    2018-01-01

    Superhydrophobic surface has aroused much interest among researchers due to the low adhesion between water and a substrate surface. This study focuses on the influence of the low adhesion of superhydrophobic surface on flashover characteristics under wet conditions. The flashover experiments were conducted under two different wet conditions. One was placing a constant volume droplet on the silicone rubber. The other one was that silicone rubber was wetted by salt fog. It was found that the ad...

  15. Deformation of fine-grained synthetic peridotite under wet conditions

    NARCIS (Netherlands)

    McDonnell, R.D.

    1997-01-01

    Fine-grained hydrated peridotite mylonites have been proposed to play an important role in controlling the strength of the continental lithosphere during rifting. For this reason, the deformation behaviour of wet fine-grained forsterite and forsterite-enstatite materials and the underlying

  16. New boundary conditions for oil reservoirs with fracture

    Science.gov (United States)

    Andriyanova, Elena; Astafev, Vladimir

    2017-06-01

    Based on the fact that most of oil fields are on the late stage of field development, it becomes necessary to produce hard-to-extract oil, which can be obtained only by use of enhance oil recovery methods. For example many low permeable or shale formations can be developed only with application of massive hydraulic fracturing technique. In addition, modern geophysical researches show that mostly oil bearing formations are complicated with tectonic faults of different shape and permeability. These discontinuities exert essential influence on the field development process and on the well performance. For the modeling of fluid flow in the reservoir with some area of different permeability, we should determine the boundary conditions. In this article for the first time the boundary conditions for the problem of fluid filtration in the reservoir with some discontinuity are considered. This discontinuity represents thin but long area, which can be hydraulic fracturing of tectonic fault. The obtained boundary condition equations allow us to take into account pressure difference above and below the section and different values of permeability.

  17. Estimation of antecedent wetness conditions for flood modelling in northern Morocco

    Directory of Open Access Journals (Sweden)

    Y. Tramblay

    2012-11-01

    Full Text Available In northern Morocco are located most of the dams and reservoirs of the country, while this region is affected by severe rainfall events causing floods. To improve the management of the water regulation structures, there is a need to develop rainfall–runoff models to both maximize the storage capacity and reduce the risks caused by floods. In this study, a model is developed to reproduce the flood events for a 655 km2 catchment located upstream of the 6th largest dam in Morocco. Constrained by data availability, a standard event-based model combining a SCS-CN (Soil Conservation Service Curve Number loss model and a Clark unit hydrograph was developed for hourly discharge simulation using 16 flood events that occurred between 1984 and 2008. The model was found satisfactory to reproduce the runoff and the temporal evolution of floods, even with limited rainfall data. Several antecedent wetness conditions estimators for the catchment were compared with the initial condition of the model. Theses estimators include an antecedent discharge index, an antecedent precipitation index and a continuous daily soil moisture accounting model (SMA, based on precipitation and evapotranspiration. The SMA model performed the best to estimate the initial conditions of the event-based hydrological model (R2 = 0.9. Its daily output has been compared with ASCAT and AMSR-E remote sensing data products, which were both able to reproduce with accuracy the daily simulated soil moisture dynamics at the catchment scale. This same approach could be implemented in other catchments of this region for operational purposes. The results of this study suggest that remote sensing data are potentially useful to estimate the soil moisture conditions in the case of ungauged catchments in Northern Africa.

  18. Cosmetic Cleansing Oil Absorption by Soft Contact Lenses in Dry and Wet Conditions.

    Science.gov (United States)

    Tsukiyama, Junko; Miyamoto, Yuko; Kodama, Aya; Fukuda, Masahiko; Shimomura, Yoshikazu

    2017-09-01

    Previous reports showed that cosmetic cleansing oil for removing makeup, which contains mineral oil and surfactant, can deform some silicone hydrogel contact lenses (SHCLs) when applied directly to the lenses, although plasma-coated SHCLs (lotrafilcon A and B) were not affected. In the present study, we investigated hydrogel lenses and SHCLs in both wet and dry conditions. Several brands of hydrogel and SHCLs were immersed in a cleansing oil solution containing Sudan Black B for 5 min under wet and dry conditions. The lenses under the wet condition were simply picked up from the saline, whereas those under the dry condition were blotted with paper wipes. After immersing, the excess solution remaining on the lenses was removed by finger rubbing with a multipurpose solution. The lenses were then examined using a stereomicroscope, and their mean brightness was measured and compared. The cosmetic cleansing oil was not absorbed by the hydrogel lenses under wet or dry conditions. However, four of seven brands of SHCLs absorbed the cosmetic cleansing oil under both conditions (dry and wet), whereas asmofilcon A absorbed it only under the dry condition. Lotrafilcon B and delefilcon A did not absorb cleansing oil even under the dry condition. Hydrogel lenses resist cosmetic cleansing oil. However, SHCLs have different degrees of resistance depending on the lens material. Some SHCLs absorbed cosmetic cleansing oil more under dry conditions than under wet conditions.

  19. U02 pellets surface properties and environmental conditions effects on the wet adsorption

    International Nuclear Information System (INIS)

    Junqueira, Fabio da S.; Carnaval, Joao Paulo R.

    2013-01-01

    Angra power plants fuels are made bye en riche uranium dioxide (UO 2 ) pellets which are assembled inside metal tubes. These tubes are welded and arranged in order to perform the final product, the fuel assembly. The UO 2 pellets have a specified humidity tolerance designed to comply with security and performance requirements when working under operating conditions in the reactor. This work intends to verify the pellet opened porosity and the environmental conditions (relative humidity and temperature) influence on the wet adsorption by UO 2 pellet. The work was done in 2 parts: Firstly, pallets groups from 3 opened porosity levels were tested under a fixed relative humidity, temperature and time. In the second part of the work, the most critical pallet group upon wet adsorption was tested under different relative humidity and temperature conditions, regarding design of experiments. The opened porosity and environmental conditions tests allowed the evolution of the wet adsorption by the UO 2 pallet. (author)

  20. A New Experimental Method for in Situ Corrosion Monitoring Under Alternate Wet-Dry Conditions

    Directory of Open Access Journals (Sweden)

    Wei Ke

    2009-12-01

    Full Text Available A new experimental method was applied in in situ corrosion monitoring of mild steel Q235 under alternate wet-dry conditions. The thickness of the electrolyte film during the wet cycle was monitored by a high-precision balance with a sensibility of 0.1 mg. At the same time, an electrochemical impedance technique was employed to study the effect of film thickness on corrosion rates. Experimental results showed that there was a critical electrolyte film condition for which the corrosion rate reached a maximum during wet-dry cycles. For the substrate, the critical condition could be described by a film thickness of about 17 μm. For the rusted specimen, the critical condition could be described by an electrolyte amount of about 0.038 g, which is equivalent to a film thickness of 38 μm. This monitoring system was very useful for studying atmospheric corrosion of metals covered by corrosion products.

  1. Standard practice for measurement of time-of-wetness on surfaces exposed to wetting conditions as in atmospheric corrosion testing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1989-01-01

    1.1 This practice covers a technique for monitoring time-of-wetness (TOW) on surfaces exposed to cyclic atmospheric conditions which produce depositions of moisture. 1.2 The practice is also applicable for detecting and monitoring condensation within a wall or roof assembly and in test apparatus. 1.3 Exposure site calibration or characterization can be significantly enhanced if TOW is measured for comparison with other sites, particularly if this data is used in conjunction with other site-specific instrumentation techniques. 1.4 The values stated in SI units are to be regarded as the standard. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  2. Chemical conditions of the Japanese neutral geothermal reservoirs

    International Nuclear Information System (INIS)

    Chiba, H.

    1991-01-01

    The aqueous speciation were calculated for fluids of seven Japanese geothermal systems. The aqueous composition as well as CO 2 partial pressure of fluid in neutral pH geothermal reservoir are controlled by silicate, calcite and anhydrite minerals. The chemical composition of neutral pH geothermal reservoir can be predictable if two parameters (e.g. temperature and one of the cation activities) are provided. (author)

  3. Substrate Wetting Under the Conditions of Drop Free Falling on a Heated Surface

    Directory of Open Access Journals (Sweden)

    Batischeva Ksenia A.

    2015-01-01

    Full Text Available We conducted an experimental study of a heated substrate wetting by drops of distilled water under the conditions of their free-falling. The studies were conducted using a shadow system, which consists of a light source, lens and high-speed video camera. It was found that the maximum wetted area of drop is directly proportional to its volume. The main ranges of evolution of distilled water drop behavior on the heated surface (change of geometry at contact with the surface have been conditionally divided.

  4. Buoyancy-driven CO2/brine flow at reservoir conditions

    Science.gov (United States)

    Oh, J.; Kim, K.; Han, W.; Kim, T.; Kim, J.; Park, E.

    2013-12-01

    Suitable geological formations should guarantee a long-term safe and reliable storage of the injected supercritical CO2. In this study we targeted the cases of gravity-driven CO2 plume migration in a storage formation and the resulting CO2 leakage to overlying formation through a possible fractures or abandoned wells. A laboratory experiment and numerical model for two-phase core-flooding tests were designed to understand the buoyancy effect on supercritical CO2 migration under reservoir conditions. A series of core flooding tests were performed with Berea sandstone cores which have 20 % porosity and 1.7×10-13 m2 permeability. Unlike the normal core-flooding tests, the core was set up in a vertical direction and the CO2 was released at the bottom of the core to investigate the gravity effect on CO2 migration. During the test, the downstream pressure was maintained at 10 MPa, and the confining pressure was kept at 20 MPa. The temperature was set to be 40 °C to reflect the 1 km subsurface environment. The CO2-flooding (drainage) tests with brine-saturated core were performed with various CO2-release periods. The CO2 saturation was measured with a linear X-ray scanner. In addition to laboratory experiments, numerical simulations were performed to provide further insight into the CO2 migration behavior. TOUGH2 with ECO2N module was used to simulate CO2/brine core-flooding tests. Dimensionless numbers (Capillary number and Bond number) were calculated with the simulation results at various time points covering both the release and monitoring period.

  5. Effect of superhydrophobicity on flashover characteristics of silicone rubber under wet conditions

    Science.gov (United States)

    Li, Yufeng; Jin, Haiyun; Nie, Shichao; Tong, Cheng; Gao, Naikui

    2018-01-01

    Superhydrophobic surface has aroused much interest among researchers due to the low adhesion between water and a substrate surface. This study focuses on the influence of the low adhesion of superhydrophobic surface on flashover characteristics under wet conditions. The flashover experiments were conducted under two different wet conditions. One was placing a constant volume droplet on the silicone rubber. The other one was that silicone rubber was wetted by salt fog. It was found that the adhesion between water droplets and a superhydrophobic surface was very low because of the presence of air cushion. Accordingly, water droplets were easy to slide on a superhydrophobic surface under the effect of electric filed. The sliding of droplets could provide a longer insulation path before flashover occurred. Results showed that flashover voltage could be improved greatly on a superhydrophobic silicone rubber surface.

  6. Effect of superhydrophobicity on flashover characteristics of silicone rubber under wet conditions

    Directory of Open Access Journals (Sweden)

    Yufeng Li

    2018-01-01

    Full Text Available Superhydrophobic surface has aroused much interest among researchers due to the low adhesion between water and a substrate surface. This study focuses on the influence of the low adhesion of superhydrophobic surface on flashover characteristics under wet conditions. The flashover experiments were conducted under two different wet conditions. One was placing a constant volume droplet on the silicone rubber. The other one was that silicone rubber was wetted by salt fog. It was found that the adhesion between water droplets and a superhydrophobic surface was very low because of the presence of air cushion. Accordingly, water droplets were easy to slide on a superhydrophobic surface under the effect of electric filed. The sliding of droplets could provide a longer insulation path before flashover occurred. Results showed that flashover voltage could be improved greatly on a superhydrophobic silicone rubber surface.

  7. Conversion of wet glass to melt at lower seismogenic zone conditions: Implications for pseudotachylyte creep

    Science.gov (United States)

    Proctor, Brooks; Lockner, David A.; Lowenstern, Jacob B.; Beeler, Nicholas M.

    2018-01-01

    Coseismic frictional melting and the production of quenched glass called pseudotachylyte is a recurring process during earthquakes. To investigate how glassy materials affect the postseismic strength and stability of faults, obsidian gouges were sheared under dry and wet conditions from 200°C to 300°C at ~150 MPa effective normal stress. Dry glass exhibited a brittle rheology at all conditions tested, exhibiting friction values and microstructures consistent with siliciclastic materials. Likewise, wet glass at 200°C exhibited a brittle rheology. In contrast, wet gouges at 300°C transitioned from brittle sliding to linear‐viscous (Newtonian) flow at strain rates studies assuming that pseudotachylyte formation and flow is solely coseismic.

  8. Gas Dispersion in Granular Porous Media under Air-Dry and Wet Conditions

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Hamamoto, S; Kawamoto, K

    2012-01-01

    dispersion. Glass beads and various sands of different shapes (angular and rounded) with mean particle diameters (d50) ranging from 0.19 to 1.51 mm at both air-dry and variable moisture contents were used as granular porous media. Gas dispersion coefficients and gas dispersivities (a = DH/v, where v...... is the pore-gas velocity) were determined by fitting the advection–dispersion equation to the measured breakthrough curves. For all test conditions, DH increased linearly with v. The test results showed that neither soil column length nor diameter had significant effect on gas dispersivity. Under air......-dry conditions, higher gas dispersivities were observed for media with wider particle size distribution and higher dry bulk density. The minor effect of particle shape on gas dispersivity was found under both air-dry and wet conditions. Under wet conditions, the variations in gas dispersivity were mainly...

  9. Adhesive Wear Performance of CFRP Multilayered Polyester Composites Under Dry/wet Contact Conditions

    Science.gov (United States)

    Danaelan, D.; Yousif, B. F.

    The tribo-performance of a new engineering composite material based on coconut fibers was investigated. In this work, coconut fibers reinforced polyester (CFRP) composites were developed. The tribo-experiments were conducted by using pin-on-disc machine under dry and wet sliding contact condition against smooth stainless steel counterface. Worn surfaces were observed using optical microscope. Friction coefficient and specific wear rate were presented as a function of sliding distance (0-0.6 km) at different sliding velocities (0.1-0.28 m/s). The effect of applied load and sliding velocity was evaluated. The results showed that all test parameters have significant influence on friction and wear characteristics of the composites. Moreover, friction coefficient increased as the normal load and speed increased, the values were about 0.7-0.9 under dry contact condition. Meanwhile, under wet contact condition, there was a great reduction in the friction coefficient, i.e. the values were about 0.1-0.2. Furthermore, the specific wear rates were found to be around 2-4 (10-3) mm3/Nm under dry contact condition and highly reduced under wet condition. In other words, the presence of water as cleaner and polisher assisted to enhance the adhesive wear performance of CFRP by about 10%. The images from optical microscope showed evidence of adhesive wear mode with transition to abrasive wear mode at higher sliding velocities due to third body abrasion. On the other hand, optical images for wet condition showed less adhesive wear and smooth surfaces.

  10. Development of Future Rule Curves for Multipurpose Reservoir Operation Using Conditional Genetic and Tabu Search Algorithms

    Directory of Open Access Journals (Sweden)

    Anongrit Kangrang

    2018-01-01

    Full Text Available Optimal rule curves are necessary guidelines in the reservoir operation that have been used to assess performance of any reservoir to satisfy water supply, irrigation, industrial, hydropower, and environmental conservation requirements. This study applied the conditional genetic algorithm (CGA and the conditional tabu search algorithm (CTSA technique to connect with the reservoir simulation model in order to search optimal reservoir rule curves. The Ubolrat Reservoir located in the northeast region of Thailand was an illustrative application including historic monthly inflow, future inflow generated by the SWAT hydrological model using 50-year future climate data from the PRECIS regional climate model in case of B2 emission scenario by IPCC SRES, water demand, hydrologic data, and physical reservoir data. The future and synthetic inflow data of reservoirs were used to simulate reservoir system for evaluating water situation. The situations of water shortage and excess water were shown in terms of frequency magnitude and duration. The results have shown that the optimal rule curves from CGA and CTSA connected with the simulation model can mitigate drought and flood situations than the existing rule curves. The optimal future rule curves were more suitable for future situations than the other rule curves.

  11. Influence of oil/gas reservoir driving conditions on reserves estimation using computer simulation

    Directory of Open Access Journals (Sweden)

    Stanisław Rychlicki

    2006-10-01

    Full Text Available One of the methods of assessing reserves is a calibration of a numerical model of a field with assumed driving conditions of the field. The influence of various energy systems assumed for the calculation on the calibration results are presented in the paper. A light oil field was selected for verification of resources on the basis of an analysis of driving conditions. At the first stage of calculations, a „Black Oil” type numerical model was used. The results of a classical „Black – Oil” model made the authors search for an alternative description of energy conditions in the reservoir. Therefore, a modified „Black-Oil” model with „vaporized oil” option, assuming that initially, after evaporation, the condensate in the reservoir was in a gaseous phase was used. The obtained simulation results for the analyzed reservoir prove the accuracy of energy conditions in the reservoir.

  12. An assessment of the skid resistance effect on traffic safety under wet-pavement conditions.

    Science.gov (United States)

    Pardillo Mayora, José M; Jurado Piña, Rafael

    2009-07-01

    Pavement-tire friction provides the grip that is required for maintaining vehicle control and for stopping in emergency situations. Statistically significant negative correlations of skid resistance values and wet-pavement accident rates have been found in previous research. Skid resistance measured with SCRIM and crash data from over 1750km of two-lane rural roads in the Spanish National Road System were analyzed to determine the influence of pavement conditions on safety and to assess the effects of improving pavement friction on safety. Both wet- and dry-pavement crash rates presented a decreasing trend as skid resistance values increased. Thresholds in SCRIM coefficient values associated with significant decreases in wet-pavement crash rates were determined. Pavement friction improvement schemes were found to yield significant reductions in wet-pavement crash rates averaging 68%. The results confirm the importance of maintaining adequate levels of pavement friction to safeguard traffic safety as well as the potential of pavement friction improvement schemes to achieve significant crash reductions.

  13. Friction between footwear and floor covered with solid particles under dry and wet conditions.

    Science.gov (United States)

    Li, Kai Way; Meng, Fanxing; Zhang, Wei

    2014-01-01

    Solid particles on the floor, both dry and wet, are common but their effects on the friction on the floor were seldom discussed in the literature. In this study, friction measurements were conducted to test the effects of particle size of solid contaminants on the friction coefficient on the floor under footwear, floor, and surface conditions. The results supported the hypothesis that particle size of solids affected the friction coefficient and the effects depended on footwear, floor, and surface conditions. On dry surfaces, solid particles resulted in friction loss when the Neolite footwear pad was used. On the other hand, solid particles provided additional friction when measured with the ethylene vinyl acetate (EVA) footwear pad. On wet surfaces, introducing solid particles made the floors more slip-resistant and such effects depended on particle size. This study provides information for better understanding of the mechanism of slipping when solid contaminants are present.

  14. Spatiotemporal characteristics of severe dry and wet conditions in the Free State Province, South Africa

    Science.gov (United States)

    Mbiriri, M.; Mukwada, G.; Manatsa, D.

    2018-02-01

    This paper assesses the spatiotemporal characteristics of agricultural droughts and wet conditions in the Free State Province of South Africa for the period between 1960 and 2013. Since agriculturally, the Free State Province is considered the bread basket of the country, understanding the variability of drought and wet conditions becomes necessary. The Standardised Precipitation Index (SPI) computed from gridded monthly precipitation data was used to assess the rainfall extreme conditions. Hot spot analysis was used to divide the province into five homogenous clusters where the spatiotemporal characteristics for each cluster were analysed. The results show a west to east increase in seasonal average total precipitation. However, the eastern part of the province demonstrates higher occurrences of droughts, with SPI ≤ - 1.282. This is despite the observation that the region shows a recent increase in droughts unlike the western region. It is also noted that significant differences in drought/wet intensities between clusters are more pronounced during the early compared to the late summer period.

  15. Conversion of Wet Glass to Melt at Lower Seismogenic Zone Conditions: Implications for Pseudotachylyte Creep

    Science.gov (United States)

    Proctor, B. P.; Lockner, D. A.; Lowenstern, J. B.; Beeler, N. M.

    2017-10-01

    Coseismic frictional melting and the production of quenched glass called pseudotachylyte is a recurring process during earthquakes. To investigate how glassy materials affect the postseismic strength and stability of faults, obsidian gouges were sheared under dry and wet conditions from 200°C to 300°C at 150 MPa effective normal stress. Dry glass exhibited a brittle rheology at all conditions tested, exhibiting friction values and microstructures consistent with siliciclastic materials. Likewise, wet glass at 200°C exhibited a brittle rheology. In contrast, wet gouges at 300°C transitioned from brittle sliding to linear-viscous (Newtonian) flow at strain rates glass by diffusion of pore water was the dominant process reducing the viscosity and promoting viscous flow. As much as 5 wt % water diffused into the glass. These results may provide insight into postseismic-slip behaviors and challenge some interpretations of fault kinematics based on studies assuming that pseudotachylyte formation and flow is solely coseismic.

  16. Air-side performance of a micro-channel heat exchanger in wet surface conditions

    Directory of Open Access Journals (Sweden)

    Srisomba Raviwat

    2017-01-01

    Full Text Available The effects of operating conditions on the air-side heat transfer, and pressure drop of a micro-channel heat exchanger under wet surface conditions were studied experimentally. The test section was an aluminum micro-channel heat exchanger, consisting of a multi-louvered fin and multi-port mini-channels. Experiments were conducted to study the effects of inlet relative humidity, air frontal velocity, air inlet temperature, and refrigerant temperature on air-side performance. The experimental data were analyzed using the mean enthalpy difference method. The test run was performed at relative air humidities ranging between 45% and 80%; air inlet temperature ranges of 27, 30, and 33°C; refrigerant-saturated temperatures ranging from 18 to 22°C; and Reynolds numbers between 128 and 166. The results show that the inlet relative humidity, air inlet temperature, and the refrigerant temperature had significant effects on heat transfer performance and air-side pressure drop. The heat transfer coefficient and pressure drop for the micro-channel heat exchanger under wet surface conditions are proposed in terms of the Colburn j factor and Fanning f factor.

  17. Improving of spent fuel monitoring in condition of Slovak wet interim spent fuel storage facility

    International Nuclear Information System (INIS)

    Miklos, M.; Krsjak, V.; Bozik, M.; Vasina, D.

    2008-01-01

    Monitoring of WWER fuel assemblies condition in Slovakia is presented in the paper. The leak tightness results of fuel assemblies used in Slovak WWER units in last 20 years are analyzed. Good experiences with the 'Sipping system' are described. The Slovak wet interim spent fuel storage facility in NPP Jaslovske Bohunice was build and put in operation in 1986. Since 1999, leak tests of WWER-440 fuel assemblies are provided by special leak tightness detection system 'Sipping in Pool' delivered by Framatome-ANP facility with external heating for the precise detection of active specimens. Another system for monitoring of fuel assemblies condition was implemented in December 2006 under the name 'SVYPP-440'. First non-active tests started at February 2007 and are described in the paper. Although those systems seems to be very effective, the detection time of all fuel assemblies in one storage pool is too long (several months). Therefore, a new 'on-line' detection system, based on new sorbent KNiFC-PAN for effective 134 Cs and 137 Cs activity was developed. This sorbent was compared with another type of sorbent NIFSIL and results are presented. The design of this detection system and its possible application in the Slovak wet spent fuel storage facility is discussed. For completeness, the initial results of the new system are also presented. (authors)

  18. A comparative study on performance of CBN inserts when turning steel under dry and wet conditions

    Science.gov (United States)

    Abdullah Bagaber, Salem; Razlan Yusoff, Ahmad

    2017-10-01

    Cutting fluids is the most unsustainable components of machining processes, it is negatively impacting on the environmental and additional energy required. Due to its high strength and corrosion resistance, the machinability of stainless steel has attracted considerable interest. This study aims to evaluate performance of cubic boron nitride (CBN) inserts for the machining parameters includes the power consumption and surface roughness. Due to the high single cutting-edge cost of CBN, the performance of significant is importance for hard finish turning. The present work also deals with a comparative study on power consumption and surface roughness under dry and flood conditions. Turning process of the stainless steel 316 was performed. A response surface methodology based box-behnken design (BBD) was utilized for statistical analysis. The optimum process parameters are determined as the overall performance index. The comparison study has been done between dry and wet stainless-steel cut in terms of minimum value of energy and surface roughness. The result shows the stainless still can be machined under dry condition with 18.57% improvement of power consumption and acceptable quality compare to the wet cutting. The CBN tools under dry cutting stainless steel can be used to reduce the environment impacts in terms of no cutting fluid use and less energy required which is effected in machining productivity and profit.

  19. CO{sub 2} interfacial properties: application to multiphase flow at reservoir conditions; Proprietes interfaciales du CO{sub 2}: application aux ecoulements en milieu poreux en pression et temperature

    Energy Technology Data Exchange (ETDEWEB)

    Chalbaud, C

    2007-07-15

    In this work we deal with the interfacial properties of CO{sub 2} at reservoir conditions with a special interest on deep saline aquifers. Each chapter of this dissertation represents a different physical scale studied with different experimental devices and simulation tools. The results obtained in the first part of this study represent a complete data set of brine-CO{sub 2} interfacial tension at reservoir conditions. A semi-analytical equation is proposed in order to facilitate the work of reservoir engineers. The second deals with the interfacial properties at the pore scale using glass micro-models at different wettability conditions. This part shows the wetting behavior of CO{sub 2} on hydrophobic or oil-wet solid surfaces. A pore network model was used for the interpretation and exploitation of these results. The third part corresponds to two different experimental approaches at the core scale at different wettability conditions associated to a modelling at flue Darcy scale. This part is a significant contribution to the validation of COORES compositional reservoir simulator developed by IFP. It has also allow us to estimate multiphase properties, Pc and kr, for brine-CO{sub 2} systems at reservoir conditions. This study presents the necessary scales to model CO{sub 2} storage in deep saline aquifers. (author)

  20. Adaptation of a leaf wetness duration model for tomato under Colombian greenhouse conditions

    Directory of Open Access Journals (Sweden)

    Rodrigo Gil

    2015-04-01

    Full Text Available Greenhouse tomato production uses structures that protect crops from extreme environmental conditions; however, the climate inside Colombian greenhouses is often not optimal and crops are susceptible to attack by fungal diseases. The use of simulation models for early warnings of attack by diseases have helped to rationalize the use of chemical pesticides by increasing their efficiency when sprayed at critical times of disease onset. The aim of this study was to calibrate the surface wetness energy balance (SWEB model to estimate the leaf wetness duration (LWD for greenhouse tomatoes in the Alto Ricaurte province (Boyaca. For the validation, the performances of the SWEB model were evaluated by comparing a simulated LWD with records from dielectric leaf wetness sensors. The model adequately represented the phenomenon of free water on the leaves for plants in two greenhouses of Santa Sofia and Sutamarchan. The model simulated an average LWD of 9.9 and 12.1 hours day-1 in Santa Sofia and Sutamarchan, respectively. However, the simulations for the two greenhouses indicated different behaviors, with average differences between the observed and simulated daily number of hours with free water of 0.8 hours for Santa Sofia, while, for Sutamarchan, the difference reached 4 hours. The fraction of correct estimates index indicated the model had the ability to correctly predict 92 and 72% of the hours with a presence or absence of LWD in Santa Sofia and Sutamarchan, respectively. The SWEB model is a useful tool for early warnings for the attack of fungal diseases in greenhouse tomatoes. However, due to the shortcomings of the greenhouse structures used for production, the crops are highly susceptible to attack from these pathogens.

  1. New insights on the complex dynamics of two-phase flow in porous media under intermediate-wet conditions.

    Science.gov (United States)

    Rabbani, Harris Sajjad; Joekar-Niasar, Vahid; Pak, Tannaz; Shokri, Nima

    2017-07-04

    Multiphase flow in porous media is important in a number of environmental and industrial applications such as soil remediation, CO 2 sequestration, and enhanced oil recovery. Wetting properties control flow of immiscible fluids in porous media and fluids distribution in the pore space. In contrast to the strong and weak wet conditions, pore-scale physics of immiscible displacement under intermediate-wet conditions is less understood. This study reports the results of a series of two-dimensional high-resolution direct numerical simulations with the aim of understanding the pore-scale dynamics of two-phase immiscible fluid flow under intermediate-wet conditions. Our results show that for intermediate-wet porous media, pore geometry has a strong influence on interface dynamics, leading to co-existence of concave and convex interfaces. Intermediate wettability leads to various interfacial movements which are not identified under imbibition or drainage conditions. These pore-scale events significantly influence macro-scale flow behaviour causing the counter-intuitive decline in recovery of the defending fluid from weak imbibition to intermediate-wet conditions.

  2. A Capillary-Based Static Phase Separator for Highly Variable Wetting Conditions

    Science.gov (United States)

    Thomas, Evan A.; Graf, John C.; Weislogel, Mark M.

    2010-01-01

    The invention, a static phase separator (SPS), uses airflow and capillary wetting characteristics to passively separate a two-phase (liquid and air) flow. The device accommodates highly variable liquid wetting characteristics. The resultant design allows for a range of wetting properties from about 0 to over 90 advancing contact angle, with frequent complete separation of liquid from gas observed when using appropriately scaled test conditions. Additionally, the design accommodates a range of air-to-liquid flow-rate ratios from only liquid flow to over 200:1 air-to-liquid flow rate. The SPS uses a helix input section with an ice-cream-cone-shaped constant area cross section (see figure). The wedge portion of the cross section is on the outer edge of the helix, and collects the liquid via centripetal acceleration. The helix then passes into an increasing cross-sectional area vane region. The liquid in the helix wedge is directed into the top of capillary wedges in the liquid containment section. The transition from diffuser to containment section includes a 90 change in capillary pumping direction, while maintaining inertial direction. This serves to impinge the liquid into the two off-center symmetrical vanes by the airflow. Rather than the airflow serving to shear liquid away from the capillary vanes, the design allows for further penetration of the liquid into the vanes by the air shear. This is also assisted by locating the air exit ports downstream of the liquid drain port. Additionally, any droplets not contained in the capillary vanes are re-entrained downstream by a third opposing capillary vane, which directs liquid back toward the liquid drain port. Finally, the dual air exit ports serve to slow the airflow down, and to reduce the likelihood of shear. The ports are stove-piped into the cavity to form an unfriendly capillary surface for a wetting fluid to carryover. The liquid drain port is located at the start of the containment region, allowing for

  3. Optimization of wet lay-up conditions for steam generators hydrazine chemical treatment

    International Nuclear Information System (INIS)

    Long, A.; Organista, M.; Brun, C.; Combrade, P.

    2002-01-01

    Since a long time, hydrazine is used as a chemical agent to prevent corrosion of unalloyed steels. This is a conventional treatment widely used by nuclear power plant operators. But its application in SG lay-up at French nuclear power plants has, however, lead to some drawbacks. Effluent releases: Due to regulation relative to release of hydrazine and alkaline chemical compounds, some plant operators limit the concentrations of reagents to levels that could lead to insufficient protection of materials. Safety hazards associated with SG nitrogen blanketing: Prohibiting use of nitrogen blankets for SG wet lay-up due to associated safety hazards could likewise jeopardize corrosion protection at normally specified hydrazine levels. As the exact limits of hydrazine action against corrosion during SG lay-up are not well known, it is sometimes difficult to evaluate the risk associated to low dosage of N 2 H 4 . In order to answer to these problems, Framatome ANP (France) decided to carry out a test program aimed to determine the limit conditions for use of hydrazine in a wet lay-up environment. (authors)

  4. Integration of advanced oxidation processes at mild conditions in wet scrubbers for odourous sulphur compounds treatment.

    Science.gov (United States)

    Vega, Esther; Martin, Maria J; Gonzalez-Olmos, Rafael

    2014-08-01

    The effectiveness of different advanced oxidation processes on the treatment of a multicomponent aqueous solution containing ethyl mercaptan, dimethyl sulphide and dimethyl disulphide (0.5 mg L(-1) of each sulphur compound) was investigated with the objective to assess which one is the most suitable treatment to be coupled in wet scrubbers used in odour treatment facilities. UV/H2O2, Fenton, photo-Fenton and ozone treatments were tested at mild conditions and the oxidation efficiency obtained was compared. The oxidation tests were carried out in magnetically stirred cylindrical quartz reactors using the same molar concentration of oxidants (hydrogen peroxide or ozone). The results show that ozone and photo-Fenton are the most efficient treatments, achieving up to 95% of sulphur compounds oxidation and a mineralisation degree around 70% in 10 min. Furthermore, the total costs of the treatments taking into account the capital and operational costs were also estimated for a comparative purpose. The economic analysis revealed that the Fenton treatment is the most economical option to be integrated in a wet scrubber to remove volatile organic sulphur compounds, as long as there are no space constraints to install the required reactor volume. In the case of reactor volume limitation or retrofitting complexities, the ozone and photo-Fenton treatments should be considered as viable alternatives. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Water level influences on body condition of Geophagus brasiliensis (Perciformes: Cichlidae in a Brazilian oligotrophic reservoir

    Directory of Open Access Journals (Sweden)

    Alejandra Filippo Gonzalez Neves dos Santos

    Full Text Available Effects of water level fluctuations on body condition of Geophagus brasiliensis were studied in a 30 km² Brazilian oligotrophic reservoir. Physiological condition (K and gonadosomatic index (GSI were compared according to water level (low and high. Females' best conditions were associated to higher resources availability during high water, since gonad development did not change between low and high water. Males' condition did not change between water levels, while the highest gonad development occurred in low water. Females presented higher reproductive investment than males, which allocated most of energy for somatic development. This strategy could be a mechanism to undergo the stress caused by oligotrophic characteristics of the reservoir enhanced during low water level.

  6. Relationship between Amount of Exited Blood During Wet-cupping with Patient's Individual Conditions and the Time of Doing it

    Directory of Open Access Journals (Sweden)

    M. Ghazanfari

    2017-04-01

    Full Text Available Aims: Wet-cupping as a therapeutic method has been recommended to be done on certain days based on authentic sources of traditional medicine in Iran. The purpose of this study was to determine the relationship between amount of exited blood during wet-cupping with patient's individual conditions and the time it was performed. Instruments & Methods: In this descriptive cross-sectional study, 391 men who were referred to a cupping center in Saveh city in the spring of 2016, were selected by simple sampling and wet-cupping in the position between the two scapula was performed. The research instrument was a questionnaire including demographic characteristics, date of reference (day, month and year, age, height, weight and amount of exited blood during the wet-cupping in gram. Data were analyzed by SPSS 16 software and using chi-square test, paired t test and one-way analysis of variance. Findings: The means of age, weight and body mass index were significantly related to the mean of amount of exited blood during wet-cupping (p0.05, but the amount of exited blood was higher in people with previous history of wet-cupping than those without previous history (p<0.001. Also, in people with hypertension, the amount of exited blood was higher than other treatment groups (p<0.05. Conclusion: Individual characteristics such as age, weight, body mass index, cause of referral and previous history of wet-cupping affect the amount of exited blood during wet-cupping, but the time of wet-cupping (day and month does not affect the amount of exited blood.

  7. Evolution of the Petrophysical and Mineralogical Properties of Two Reservoir Rocks Under Thermodynamic Conditions Relevant for CO2 Geological Storage at 3 km Depth

    International Nuclear Information System (INIS)

    Rimmel, G.; Barlet-Gouedard, V.; Renard, F.

    2010-01-01

    Injection of carbon dioxide (CO 2 ) underground, for long-term geological storage purposes, is considered as an economically viable option to reduce greenhouse gas emissions in the atmosphere. The chemical interactions between supercritical CO 2 and the potential reservoir rock need to be thoroughly investigated under thermodynamic conditions relevant for geological storage. In the present study, 40 samples of Lavoux limestone and Adamswiller sandstone, both collected from reservoir rocks in the Paris basin, were experimentally exposed to CO 2 in laboratory autoclaves specially built to simulate CO 2 -storage-reservoir conditions. The two types of rock were exposed to wet supercritical CO 2 and CO 2 -saturated water for one month, at 28 MPa and 90 C, corresponding to conditions for a burial depth approximating 3 km. The changes in mineralogy and micro-texture of the samples were measured using X-ray diffraction analyses, Raman spectroscopy, scanning-electron microscopy, and energy-dispersion spectroscopy microanalysis. The petrophysical properties were monitored by measuring the weight, density, mechanical properties, permeability, global porosity, and local porosity gradients through the samples. Both rocks maintained their mechanical and mineralogical properties after CO 2 exposure despite an increase of porosity and permeability. Microscopic zones of calcite dissolution observed in the limestone are more likely to be responsible for such increase. In the sandstone, an alteration of the petro-fabric is assumed to have occurred due to clay minerals reacting with CO 2 . All samples of Lavoux limestone and Adamswiller sandstone showed a measurable alteration when immersed either in wet supercritical CO 2 or in CO 2 -saturated water. These batch experiments were performed using distilled water and thus simulate more severe conditions than using formation water (brine). (authors)

  8. CO2 Capture by Injection of Flue Gas or CO2-N2 Mixtures into Hydrate Reservoirs: Dependence of CO2 Capture Efficiency on Gas Hydrate Reservoir Conditions.

    Science.gov (United States)

    Hassanpouryouzband, Aliakbar; Yang, Jinhai; Tohidi, Bahman; Chuvilin, Evgeny; Istomin, Vladimir; Bukhanov, Boris; Cheremisin, Alexey

    2018-04-03

    Injection of flue gas or CO 2 -N 2 mixtures into gas hydrate reservoirs has been considered as a promising option for geological storage of CO 2 . However, the thermodynamic process in which the CO 2 present in flue gas or a CO 2 -N 2 mixture is captured as hydrate has not been well understood. In this work, a series of experiments were conducted to investigate the dependence of CO 2 capture efficiency on reservoir conditions. The CO 2 capture efficiency was investigated at different injection pressures from 2.6 to 23.8 MPa and hydrate reservoir temperatures from 273.2 to 283.2 K in the presence of two different saturations of methane hydrate. The results showed that more than 60% of the CO 2 in the flue gas was captured and stored as CO 2 hydrate or CO 2 -mixed hydrates, while methane-rich gas was produced. The efficiency of CO 2 capture depends on the reservoir conditions including temperature, pressure, and hydrate saturation. For a certain reservoir temperature, there is an optimum reservoir pressure at which the maximum amount of CO 2 can be captured from the injected flue gas or CO 2 -N 2 mixtures. This finding suggests that it is essential to control the injection pressure to enhance CO 2 capture efficiency by flue gas or CO 2 -N 2 mixtures injection.

  9. Wet-Strengthening of Paper in Neutral pH Papermaking Conditions

    Science.gov (United States)

    Crisp, M. T.; Riehle, Richard J.

    The ability to wet-strengthen paper is an important requirement of the paper industry because wet strength agents allow for the manufacture of a variety of paper grades and products. The most significant area of application is in the manufacture of hygiene grades of paper, including hand towels and facial tissues, kitchen towels and serviettes, and other tableware products. Another important area of application is in packaging grades, including liquid packaging board for fruit juice and milk cartons; carrier bags and paper sacks; and corrugated cardboard boxes for transportation of fruit, meat and other items. Speciality grades, such as tea bags and coffee filters, bottle labels and currency paper, and wallpaper and poster paper also use wet strength agents. In fact, any grade of paper that needs to maintain a degree of strength and integrity after becoming wet involves the application of a wet strength agent.

  10. Constructing development and integrated coastal zone management in the conditions of the landslide slopes of Cheboksary water reservoir (Volga River)

    Science.gov (United States)

    Nikonorova, I. V.

    2018-01-01

    Uncontrolled construction and insufficient accounting of engineering-geological and hydro-geological conditions of the coastal zone, intensified technogenic impact on sloping surfaces and active urbanization led to the emergence of serious problems and emergency situations on the coasts of many Volga reservoirs, including the Cheboksary reservoir, within Cheboksary urban district and adjacent territories of Chuvashia. This article is devoted to substantiation of the possibility of rational construction development of landslide slopes of the Cheboksary water reservoir.

  11. Multiple long-term trends and trend reversals dominate environmental conditions in a man-made freshwater reservoir.

    Science.gov (United States)

    Znachor, Petr; Nedoma, Jiří; Hejzlar, Josef; Seďa, Jaromír; Kopáček, Jiří; Boukal, David; Mrkvička, Tomáš

    2018-05-15

    Man-made reservoirs are common across the world and provide a wide range of ecological services. Environmental conditions in riverine reservoirs are affected by the changing climate, catchment-wide processes and manipulations with the water level, and water abstraction from the reservoir. Long-term trends of environmental conditions in reservoirs thus reflect a wider range of drivers in comparison to lakes, which makes the understanding of reservoir dynamics more challenging. We analysed a 32-year time series of 36 environmental variables characterising weather, land use in the catchment, reservoir hydrochemistry, hydrology and light availability in the small, canyon-shaped Římov Reservoir in the Czech Republic to detect underlying trends, trend reversals and regime shifts. To do so, we fitted linear and piecewise linear regression and a regime shift model to the time series of mean annual values of each variable and to principal components produced by Principal Component Analysis. Models were weighted and ranked using Akaike information criterion and the model selection approach. Most environmental variables exhibited temporal changes that included time-varying trends and trend reversals. For instance, dissolved organic carbon showed a linear increasing trend while nitrate concentration or conductivity exemplified trend reversal. All trend reversals and cessations of temporal trends in reservoir hydrochemistry (except total phosphorus concentrations) occurred in the late 1980s and during 1990s as a consequence of dramatic socioeconomic changes. After a series of heavy rains in the late 1990s, an administrative decision to increase the flood-retention volume of the reservoir resulted in a significant regime shift in reservoir hydraulic conditions in 1999. Our analyses also highlight the utility of the model selection framework, based on relatively simple extensions of linear regression, to describe temporal trends in reservoir characteristics. This approach can

  12. Mechanical characteristics of nanocellulose-PEG bionanocomposite wound dressings in wet conditions.

    Science.gov (United States)

    Sun, Fengzhen; Nordli, Henriette R; Pukstad, Brita; Kristofer Gamstedt, E; Chinga-Carrasco, Gary

    2017-05-01

    Wood nanocellulose has been proposed for wound dressing applications partly based on its capability to form translucent films with good liquid absorption capabilities. Such properties are adequate for non-healing and chronic wounds where adequate management of exudates is a requirement. In addition, the translucency will allow to follow the wound development without the necessity to remove the dressing from the wound. Understanding the mechanical properties of nanocellulose films and dressings are also most important for tailoring optimizing wound dressing structures with adequate strength, conformability, porosity and exudate management. Mechanical properties are usually assessed in standard conditions (50% relative humidity, RH), which is not relevant in a wound management situation. In this study we have assessed the mechanical properties of three nanocellulose grades varying in the degree of nanofibrillation. The effect of nanofibrillation and of polyethylene glycol (PEG) addition, on the tensile strength, elongation and elastic modulus were assessed after 24h in water and in phosphate-buffered saline (PBS). The results reveal the behavior of the nanocellulose dressings after wetting and shed light into the development of mechanical properties in environments, which are relevant from a wound management point of view. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Performance evaluation of two wet bulb globe temperature equipment for heat stress assessment in hot/dry and hot/wet conditions

    Directory of Open Access Journals (Sweden)

    Habibollah Dehghan

    2014-01-01

    Conclusion: Since there is a high correlation between the values recorded by two devices and a remarkable cost - efficacy of WBGT Model 686 , using WBGT Model 686 is an acceptable method for measuring the heat stress if the prediction equations are utilized. According to the different temperature conditions, was obtained dry temperature, wet temperature and globe temperature both devices measurement in different climatic conditions equation WBGT Casella = 2.04 + 1.03 (WBGT Model 686 . About 2 units WBGT Model 686 lower than the WBGT Casella and recommend the measures to be considered in this case as well as the manufacturers also, recommend doing that the reform of sensor measurements and the calculation methods.

  14. A non-reflecting boundary condition for the finite element modeling of infinite reservoir with layered sediment

    Science.gov (United States)

    Gogoi, Indrani; Maity, Damodar

    2006-10-01

    The design of seismic resistant concrete gravity dam necessitates accurate determination of hydrodynamic pressure developed in the adjacent reservoir. The hydrodynamic pressure developed on structure is dependent on the physical characteristics of the boundaries surrounding the reservoir including reservoir bottom. The sedimentary material in the reservoir bottom absorbs energy at the bottom, which will affect the hydrodynamic pressure at the upstream face of the dam. The fundamental parameter characterizing the effect of absorption of hydrodynamic pressure waves at the reservoir bottom due to sediment is the reflection coefficient. The wave reflection coefficient is determined from parameters based on sediment layer thickness, its material properties and excitation frequencies. An analytical or a closed-form solution cannot account for the arbitrary geometry of the dam or reservoir bed profile. This problem can be efficiently tackled with finite element technique. The need for an accurate truncation boundary is felt to reduce the computational domain of the unbounded reservoir system. An efficient truncation boundary condition (TBC) which accounts for the reservoir bottom effect is proposed for the finite element analysis of infinite reservoir. The results show the efficiency of the proposed truncation boundary condition.

  15. The sensitivity of Sphagnum to surface layer conditions in a re-wetted bog: a simulation study of water stress

    NARCIS (Netherlands)

    Schouwenaars, J.M.; Gosen, A.M.

    2007-01-01

    The behaviour of the water table in re-wetted bogs varies widely between different locations so that recolonising Sphagnum is vulnerable to water stress, especially when the water table is drawn down in summer. It is important to understand how physical site conditions influence the occurrence of

  16. Dry/Wet Conditions Monitoring Based on TRMM Rainfall Data and Its Reliability Validation over Poyang Lake Basin, China

    Directory of Open Access Journals (Sweden)

    Xianghu Li

    2013-11-01

    Full Text Available Local dry/wet conditions are of great concern in regional water resource and floods/droughts disaster risk management. Satellite-based precipitation products have greatly improved their accuracy and applicability and are expected to offer an alternative to ground rain gauges data. This paper investigated the capability of Tropical Rainfall Measuring Mission (TRMM rainfall data for monitoring the temporal and spatial variation of dry/wet conditions in Poyang Lake basin during 1998–2010, and validated its reliability with rain gauges data from 14 national meteorological stations in the basin. The results show that: (1 the daily TRMM rainfall data does not describe the occurrence and contribution rates of precipitation accurately, but monthly TRMM data have a good linear relationship with rain gauges rainfall data; (2 both the Z index and Standardized Precipitation Index (SPI based on monthly TRMM rainfall data oscillate around zero and show a consistent interannual variability as compared with rain gauges data; (3 the spatial pattern of moisture status, either in dry months or wet months, based on both the Z index and SPI using TRMM data, agree with the observed rainfall. In conclusion, the monthly TRMM rainfall data can be used for monitoring the variation and spatial distribution of dry/wet conditions in Poyang Lake basin.

  17. Non-Markovian decay and lasing condition in an optical microcavity coupled to a structured reservoir

    International Nuclear Information System (INIS)

    Longhi, Stefano

    2006-01-01

    The decay dynamics of the classical electromagnetic field in a leaky optical resonator supporting a single mode coupled to a structured continuum of modes (reservoir) is theoretically investigated, and the issue of threshold condition for lasing in presence of an inverted medium is comprehensively addressed. Specific analytical results are given for a single-mode microcavity resonantly coupled to a coupled resonator optical waveguide, which supports a band of continuous modes acting as decay channels. For weak coupling, the usual exponential Weisskopf-Wigner (Markovian) decay of the field in the bare resonator is found, and the threshold for lasing increases linearly with the coupling strength. As the coupling between the microcavity and the structured reservoir increases, the field decay in the passive cavity shows nonexponential features, and correspondingly the threshold for lasing ceases to increase, reaching a maximum and then starting to decrease as the coupling strength is further increased. A singular behavior for the 'laser phase transition', which is a clear signature of strong non-Markovian dynamics, is found at critical values of the coupling between the microcavity and the reservoir

  18. Adaptation of continuous biogas reactors operating under wet fermentation conditions to dry conditions with corn stover as substrate.

    Science.gov (United States)

    Kakuk, Balázs; Kovács, Kornél L; Szuhaj, Márk; Rákhely, Gábor; Bagi, Zoltán

    2017-08-01

    Corn stover (CS) is the agricultural by-product of maize cultivation. Due to its high abundance and high energy content it is a promising substrate for the bioenergy sector. However, it is currently neglected in industrial scale biogas plants, because of its slow decomposition and hydrophobic character. To assess the maximum biomethane potential of CS, long-term batch fermentations were carried out with various substrate concentrations and particle sizes for 72 days. In separate experiments we adapted the biogas producing microbial community in wet fermentation arrangement first to the lignocellulosic substrate, in Continuous Stirred Tank Reactor (CSTR), then subsequently, by continuously elevating the feed-in concentration, to dry conditions in solid state fermenters (SS-AD). In the batch tests, the produce 90% of the total biomethane yield than the amount of substrate added to the fermentation lowered the specific methane yield. In the CSTR experiment, the daily substrate loading was gradually increased from 1 to 2 g vs /L/day until the system produced signs of overloading. Then the biomass was transferred to SS-AD reactors and the adaptation process was studied. Although the specific methane yields were lower in the SS-AD arrangement (177 mL CH 4 /g vs in CSTR vs. 105 mL in SS-AD), the benefits of process operational parameters, i.e. lower energy consumption, smaller reactor volume, digestate amount generated and simpler configuration, may compensate the somewhat lower yield. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Determination of aerodynamic damping of twin cables in wet conditions through passive-dynamic wind tunnel tests

    DEFF Research Database (Denmark)

    Eriksen, Mads Beedholm; Mattiello, E.; Georgakis, Christos T.

    2013-01-01

    Moderate amplitude cable vibrations continue to be reported on the cable-stayed Øresund Bridge, despite the presence of helical fillets and dampers. The vibrations are particularly notable in wet conditions, which would suggest a form of rain-wind induced vibrations (RWIV). A statistical...... operational modal analysis of the monitored vibrations revealed, in certain conditions and for specific wind velocities, the presence of negative aerodynamic damping.To investigate the observed aerodynamic damping of the twin cable arrangement further, a series of 1:2.3 scale passive-dynamic wind tunnel tests...... was performed at the DTU/FORCETechnology ClimaticWind Tunnel facility in Kgs. Lyngby, Denmark. Tests were performed for both dry and wet conditions, with and without helical fillets. The specific relative cable-wind angle tested was identified as critical from the aforementioned full-scale monitoring...

  20. Structural analysis of porous rock reservoirs subjected to conditions of compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Friley, J.R.

    1980-01-01

    Investigations are described which were performed to assess the structural behavior of porous rock compressed air energy storage (CAES) reservoirs subjected to loading conditions of temperature and pressure felt to be typical of such an operation. Analyses performed addressed not only the nominal or mean reservoir response but also the cyclic response due to charge/discharge operation. The analyses were carried out by assuming various geometrical and material related parameters of a generic site. The objective of this study was to determine the gross response of a generic porous reservoir. The site geometry for this study assumed a cylindrical model 122 m in dia and 57 m high including thicknesses for the cap, porous, and base rock formations. The central portion of the porous zone was assumed to be at a depth of 518 m and at an initial temperature of 20/sup 0/C. Cyclic loading conditions of compressed air consisted of pressure values in the range of 4.5 to 5.2 MPa and temperature values between 143 and 204/sup 0/C.Various modes of structural behavior were studied. These response modes were analyzed using loading conditions of temperature and pressure (in the porous zone) corresponding to various operational states during the first year of simulated site operation. The results of the structural analyses performed indicate that the most severely stressed region will likely be in the wellbore vicinity and hence highly dependent on the length of and placement technique utilized in the well production length. Analyses to address this specific areas are currently being pursued.

  1. Comparison of friction forces between stainless orthodontic steel brackets and TiNi wires in wet and dry conditions.

    Science.gov (United States)

    Phukaoluan, Aphinan; Khantachawana, Anak; Kaewtatip, Pongpan; Dechkunakorn, Surachai; Anuwongnukroh, Niwat; Santiwong, Peerapong; Kajornchaiyakul, Julathep

    2017-03-01

    In sliding mechanics, frictional force is an important counter-balancing element to orthodontic tooth movement, which must be controlled in order to allow application of light continuous forces. The purpose of this study was to compare the frictional forces between a stainless steel bracket and five different wire alloys under dry and wet (artificial saliva) conditions. TiNi, TiNiCu, TiNiCo, commercial wires A and commercial wires B with equal dimensions of 0.016×0.022'' were tested in this experiment. The stainless steel bracket was chosen with a slot dimension of 0.022''. Micro-hardness of the wires was measured by the Vickers micro-hardness test. Surface topography of wires was measured by an optical microscope and quantified using surface roughness testing. Static and kinetic friction forces were measured using a custom-designed apparatus, with a 3-mm stretch of wire alloy at a crosshead speed of 1mm/min. The static and dynamic frictions in the wet condition tended to decrease more slowly than those in the dry condition. Therefore, the friction of TiNiCu and commercial wires B would increase. Moreover, these results were associated with scarred surfaces, i.e. the increase in friction would result in a larger bracket microfracture. From the results, it is seen that copper addition resulted in an increase in friction under both wet and dry conditions. However, the friction in the wet condition was less than that in dry condition due to the lubricating effect of artificial saliva. Copyright © 2016 CEO. Published by Elsevier Masson SAS. All rights reserved.

  2. Uncooled EGR as a means of limiting wall-wetting under early direct injection conditions

    NARCIS (Netherlands)

    Boot, M.D.; Luijten, C.C.M.; Somers, L.M.T.; Eguz, U.; Erp, D.D.T.M. van; Albrecht, A.; Baert, R.S.G.

    2009-01-01

    Collision of injected fuel spray against the cylinder liner (wall-wetting) is one of the main hurdles that must be overcome in order for early direct injection Premixed Charge Compression Ignition (EDI PCCI) combustion to become a viable alternative for conventional DI diesel combustion. Preferably,

  3. Organic matter cycling in a neotropical reservoir: effects of temperature and experimental conditions

    Directory of Open Access Journals (Sweden)

    Flávia Bottino

    2013-06-01

    Full Text Available AIM:This study reports a comparison between decomposition kinetics of detritus derived from two macrophyte species (Polygonum lapathifolium L.: Polygonaceae; Eichhornia azurea (Sw. Kunth.: Pontederiaceae growing in a neotropical reservoir (Brazil, under laboratory and field conditions, in order to assess hypotheses on the main differences in factors affecting organic matter cycling, including the effect of temperature. METHODS: Plant and water samples were collected from the reservoir in August 2009. In field incubation mass loss was assessed using a litter bag technique and in the laboratory the decay was followed using a decomposition chamber maintained under controlled conditions (i.e. in the dark, at 15 ºC and 25 ºC. A kinetic model was adopted to explain and compare the organic matter decay, ANOVA (Repeated Measures testing was used to describe the differences between the treatments and a linear correlation was used to compare in situ and in vitro experiments. RESULTS: The mass decay was faster in natural conditions with rapid release of the labile-soluble portion. The simulated values of mineralization rates of dissolved organic matter and refractory organic matter were rapid in high temperatures (25 ºC. The high Q10 results (mainly for E. azurea, and experimental conditions, and outcomes of ANOVA testing indicate the temperature variation (10 ºC influence the rates of mass decay. CONCLUSIONS: The results suggested rapid organic matter cycling in warm months (from October to December supporting the microbial loop. Although the particulate organic matter losses are high in field conditions the results are of the same magnitude in both conditions suggesting an equivalence of the mass decay kinetic.

  4. Significance of settling model structures and parameter subsets in modelling WWTPs under wet-weather flow and filamentous bulking conditions

    DEFF Research Database (Denmark)

    Ramin, Elham; Sin, Gürkan; Mikkelsen, Peter Steen

    2014-01-01

    Current research focuses on predicting and mitigating the impacts of high hydraulic loadings on centralized wastewater treatment plants (WWTPs) under wet-weather conditions. The maximum permissible inflow to WWTPs depends not only on the settleability of activated sludge in secondary settling tanks...... (SSTs) but also on the hydraulic behaviour of SSTs. The present study investigates the impacts of ideal and non-ideal flow (dry and wet weather) and settling (good settling and bulking) boundary conditions on the sensitivity of WWTP model outputs to uncertainties intrinsic to the one-dimensional (1-D......) SST model structures and parameters. We identify the critical sources of uncertainty in WWTP models through global sensitivity analysis (GSA) using the Benchmark simulation model No. 1 in combination with first- and second-order 1-D SST models. The results obtained illustrate that the contribution...

  5. In vitro assessment of ultraviolet protection of coloured cotton knitted fabrics with different structures under stretched and wet conditions.

    Science.gov (United States)

    Wong, W Y; Lam, J K C; Kan, C W; Postle, R

    2015-04-01

    Clothing provides intrinsic ultraviolet (UV) protection that can be improved by colouration. However, the daily wearing condition can undermine the UV protection of coloured clothing wherein garments are stretched by body movement and/or wetted by perspiration of wearers. Knitwear is an indispensable clothing in summer, but its UV protection against wearing conditions lacks extensive study especially in a fabric structural approach. This article aimed at narrowing the research gap by focusing on the UV protection against stretch and wetness provided by various knitted fabric constructions incorporating the knit, tuck and miss stitches. The results show that the black knitted fabrics exhibit a significant reduction in the UV protection factor by 53% on average at a 10% stretch level. Knitted fabrics with miss stitches retained good UV protection even when the fabrics were stretched by 20% of its original dimensions. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Relationships among cyanobacteria, zooplankton and fish in sub-bloom conditions in the Sulejow Reservoir

    Directory of Open Access Journals (Sweden)

    Zbigniew Kaczkowski

    2017-01-01

    Full Text Available The occurrence of cyanobacteria is particularly characteristic of shallow eutrophic waters, and they often form massive ‘blooms’ that can affect aquatic invertebrates and fish. However, even a low abundance of cyanobacteria can be hazardous to aquatic organisms, due to the production of toxic metabolites. The aim of this study was to investigate the relationship between cyanobacteria and their toxicity (biological activity towards zooplankton and fish communities, when only low concentrations of cyanobacterial chlorophyll a (less than 20 μg L-1 are detected, i.e. in sub-bloom conditions. Measurements were performed in Sulejow Reservoir (Central Poland, a shallow, lowland, eutrophic reservoir, in which cyanobacterial blooms occur regularly. Fish were assessed using echo-sounding (distribution and by gillnetting (species composition. Simultaneously, zooplankton, cyanobacteria and physico-chemical characteristics were studied at 14 stations situated along hydroacoustic transects. Parameters that characterized the cyanobacteria (cyanobacterial chlorophyll a concentration, the number of 16S rRNA and the mcyA gene copies and microcystin (MC concentration were consistently correlated (based on a principal component analysis, and the highest values were found in the downstream region of the study area. This ‘cyano-complex’ was also positively correlated with oxygen concentration, pH and phosphate levels, but was negatively correlated with temperature and the concentrations of nitrates and nitrites. In Sulejow Reservoir in 2013 the biomass of large zooplankton filter feeders decreased along with increasing MC concentration and fish densities, while small filter feeders did not present such relationships with regards to fish densities. Fish abundance tended to decrease at stations with a lower abundance of cyanobacteria and with growing toxic genotype copies and MC concentration.

  7. Magma reservoir conditions beneath Tsurumi volcano, SW Japan: Evidence from amphibole thermobarometry and seismicity

    Science.gov (United States)

    Nagasaki, Shiho; Ishibashi, Hidemi; Suwa, Yukiko; Yasuda, Atsushi; Hokanishi, Natsumi; Ohkura, Takahiro; Takemura, Keiji

    2017-05-01

    Calcic amphibole phenocrysts in the Tsurumidake summit (TS) lava, which was produced during the most recent eruption at Tsurumi Volcano (SW Japan) at around 7.5-10.5 ka, have been analyzed to determine the pre-eruptive conditions, such as temperature (T), pressure (P), oxygen fugacity (fO2), SiO2 content (SiO2melt), and FeO*/MgO ratio (FeO*/MgOmelt), of coexisting silicate melts in the magma reservoir beneath the volcano. Although most of the amphibole phenocrysts have been completely decomposed to a fine-grained opaque symplectite, 6% of the grains remain intact. The degree of amphibole breakdown (DAB), defined as the ratio of the area of symplectite to the area of symplectite plus relict amphibole in each phenocryst, varies from 20% to 100%. Compositional zoning was not observed in the amphibole grains, however, two distinct groups of amphibole phenocrysts have been identified based on their chemical compositions: group-I amphiboles, which are relatively Si-poor, and [6]Al-rich, and have a relatively high Mg# [100Mg/(Mg + Fe2 +)]; and group-II amphiboles, which are Si-rich, and [6]Al-poor, and have a relatively low Mg#. Empirical equations for geothermobarometry, oxygen barometry and chemometry that exclusively rely on the amphibole composition were applied to estimate the T-P-fO2-SiO2melt-FeO*/MgOmelt conditions of the silicate melts with which the amphibole crystals equilibrated. The results show that group-I and group-II amphiboles equilibrated with andesitic melts (group-I melts) and dacitic-rhyolitic melts (group-II melts), respectively. The T-P-fO2 conditions of group-I melts were estimated as 374-483 MPa ( 13.9-17.9 km depth), 950 °C, and NNO + 1.3, respectively, and those of group-II melts were 93-242 MPa ( 3.4-9.0 km depth), 824-913 °C, and NNO + 0.6-1.7, respectively. The estimated T-P-fO2-SiO2melt-FeO*/MgOmelt conditions were almost constant for group-I melts, whereas the T, ΔNNO, and FeO*/MgOmelt values of group-II melts decreased with increasing

  8. Sustainability of small reservoirs and large scale water availability under current conditions and climate change

    NARCIS (Netherlands)

    Krol, Martinus S.; de Vries, Marjella J.; van Oel, P.R.; Carlos de Araújo, José

    2011-01-01

    Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts

  9. Ecological aspects of the hydro power industry and possible means to improve ecological conditions of water reservoirs

    International Nuclear Information System (INIS)

    Chaika, A.

    1997-01-01

    In this report the analyse a hydro power generating structure as a multitask water management scheme and its environmental impact of water users was viewed. It is possible to improve sanitary, biological and hydraulic condition of reservoirs and limit water overgrowing by implementing the following set of measures: 1) limitation of poorly purified and non-organic discharges in these reservoirs by implementing purification structures; 2) construction of accumulation reservoirs for sewage water planted with plants-biological accumulators with consequent periodic removal of these plants; use of purificated water for irrigation; 3) limitation of biogens coming with agricultural drainage water; 4) annual removal of water plants in shallow places of reservoirs; 5) removal of silt (cleaning of the bottom) where technically possible; 6) aeration of reservoirs or their parts, especially shallow areas, including recreation areas; 7) controlled development of flora and fauna of reservoirs and neighbouring territories; it has been discovered that plant-eating fish has useful impact as biological purificatiors; 8) processing of seston (weighted plankton and remains of organisms) and water plants to get different producers (forage additions for animals, albumin-vitamin additions, chlorophyll and carotene paste, pharmaceutical materials and forage yeast). Development of silt removal technology is a very sharp problem especially for particular areas of Kiev reservoir contaminated with radioactive waste

  10. Acute Illness Among Surfers After Exposure to Seawater in Dry- and Wet-Weather Conditions.

    Science.gov (United States)

    Arnold, Benjamin F; Schiff, Kenneth C; Ercumen, Ayse; Benjamin-Chung, Jade; Steele, Joshua A; Griffith, John F; Steinberg, Steven J; Smith, Paul; McGee, Charles D; Wilson, Richard; Nelsen, Chad; Weisberg, Stephen B; Colford, John M

    2017-10-01

    Rainstorms increase levels of fecal indicator bacteria in urban coastal waters, but it is unknown whether exposure to seawater after rainstorms increases rates of acute illness. Our objective was to provide the first estimates of rates of acute illness after seawater exposure during both dry- and wet-weather periods and to determine the relationship between levels of indicator bacteria and illness among surfers, a population with a high potential for exposure after rain. We enrolled 654 surfers in San Diego, California, and followed them longitudinally during the 2013-2014 and 2014-2015 winters (33,377 days of observation, 10,081 surf sessions). We measured daily surf activities and illness symptoms (gastrointestinal illness, sinus infections, ear infections, infected wounds). Compared with no exposure, exposure to seawater during dry weather increased incidence rates of all outcomes (e.g., for earache or infection, adjusted incidence rate ratio (IRR) = 1.86, 95% confidence interval (CI): 1.27, 2.71; for infected wounds, IRR = 3.04, 95% CI: 1.54, 5.98); exposure during wet weather further increased rates (e.g., for earache or infection, IRR = 3.28, 95% CI: 1.95, 5.51; for infected wounds, IRR = 4.96, 95% CI: 2.18, 11.29). Fecal indicator bacteria measured in seawater (Enterococcus species, fecal coliforms, total coliforms) were strongly associated with incident illness only during wet weather. Urban coastal seawater exposure increases the incidence rates of many acute illnesses among surfers, with higher incidence rates after rainstorms. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.

  11. The competition between H2O and CO2 adhesion at reservoir conditions

    DEFF Research Database (Denmark)

    Sølling, Theis Ivan; Budi, Akin; Mogensen, K.

    2015-01-01

    Density functional theory was applied (B3LYP) to answer whether conditions exist where CO2 adhesion to three different lithologies becomes stronger than H2O adhesion. The answer is that it does not seem to be the case. This is taken to indicate that the reservoirs that we have represented by simple...... models are prone to CO2 storage. Moreover, we have obtained an overview of the effect of including entropy contributions and zero point vibrational energies in the calculation of the adhesion energies. The consequence of applying simple dispersion and solvent models are also addressed. The study is based...... around very simplified model systems of calcite, quartz and clays in order address the basic effects. Rather than attempting to obtain quantitative agreement we are observing the qualitative trends. When entropy, ZPE and a continuum model is included the result is smaller binding energies. However...

  12. A Combined Thermodynamic and Kinetic Model for Barite Prediction at Oil Reservoir Conditions

    DEFF Research Database (Denmark)

    Zhen Wu, Bi Yun

    dependence of Pitzer parameters for NaCl, Na2SO4 and BaCl2 were derived from published osmotic coefficient data (PhD Study 2). Furthermore, barite solubility was determined experimentally at 90 °C and pressures of 150 and 250 bar. Comparison of barite solubilities calculated with the Pitzer model...... of this research was to develop a model, based on thermodynamics and kinetics, for predicting barite precipitation rates in saline waters at the pressures and temperatures of oil bearing reservoirs, using the geochemical modelling code PHREEQC. This task is complicated by the conditions where traditional methods...... to 90 C at 1 bar of pressure. Resulting thermodynamic and kinetic parameters were combined and coupled with PHREEQC to predict precipitation scaling rates in three oil production wells, where barite has been observed. Average linear growth rates of 3, 2.5 and 2 mm of barite per year were estimated...

  13. Study on Surface Integrity of AISI 1045 Carbon Steel when machined by Carbide Cutting Tool under wet conditions

    Directory of Open Access Journals (Sweden)

    Tamin N. Fauzi

    2017-01-01

    Full Text Available This paper presents the evaluation of surface roughness and roughness profiles when machining carbon steel under wet conditions with low and high cutting speeds. The workpiece materials and cutting tools selected in this research were AISI 1045 carbon steel and canela carbide inserts graded PM25, respectively. The cutting tools undergo machining tests by CNC turning operations and their performances were evaluated by their surface roughness value and observation of the surface roughness profile. The machining tests were held at varied cutting speeds of 35 to 53 m/min, feed rate of 0.15 to 0.50 mm/rev and a constant depth of cut of 1 mm. From the analysis, it was found that surface roughness increased as the feed rate increased. Varian of surface roughness was suspected due to interaction between cutting speeds and feed rates as well as nose radius conditions; whether from tool wear or the formation of a built-up edge. This study helps us understand the effect of cutting speed and feed rate on surface integrity, when machining AISI 1045 carbon steel using carbide cutting tools, under wet cutting conditions.

  14. Conditioning of Si-interfaces by wet-chemical oxidation: Electronic interface properties study by surface photovoltage measurements

    Science.gov (United States)

    Angermann, Heike

    2014-09-01

    The field-modulated surface photovoltage (SPV) method, a very surface sensitive technique, was utilized to determine electronic interface properties on wet-chemically oxidized and etched silicon (Si) interfaces. The influence of preparation-induced surface micro-roughness and un-stoichiometric oxides on the resulting the surface charge, energetic distribution Dit(E), and density Dit,min of rechargeable states was studied by simultaneous, spectroscopic ellipsometry (SE) measurements on polished Si(111) and Si(100) substrates. Based on previous findings and new research, a study of conventional and newly developed wet-chemical oxidation methods was established, correlating the interactions between involved oxidizing and etching solutions and the initial substrate morphology to the final surface conditioning. It is shown, which sequences of wet-chemical oxidation and oxide removal, have to be combined in order to achieve atomically smooth, hydrogen terminated surfaces, as well as ultra-thin oxide layers with low densities of rechargeable states on flat, saw damage etched, and textured Si substrates, as commonly applied in silicon device and solar cell manufacturing. These conventional strategies for wet-chemical pre-treatment are mainly based on concentrated solutions. Therefore, special attention was put on the development of more environmentally acceptable processes, utilizing e.g. hot pure water with low contents of oxygen or hydrochloric acid, and of ozone, working at ambient temperatures. According to our results, these methods could be a high quality and low cost alternative to current approaches with liquid chemicals for the preparation of hydrophobic Si substrate surfaces and ultra-thin passivating oxide layers. As demonstrated for selected examples, the effect of optimized wet-chemical pre-treatments can be preserved during subsequent soft plasma enhanced chemical vapor depositions of Si oxides (SiOx), or amorphous materials such as Si (a-Si:H), Si nitride (a

  15. Estimation of different coal compressibilities of coalbed methane reservoirs under replicated in situ condition

    Science.gov (United States)

    Liu, Shimin

    Studies completed recently have shown that desorption of methane results in a change in the matrix volume of coal thus altering the permeability of, and production rates from, coalbed methane (CBM) reservoirs. An accurate estimation of different coal compressibilities is, therefore, critical in CBM operations in order to model and project gas production rates. Furthermore, a comprehensive knowledge of the dynamic permeability helps in understanding the unique feature of CBM production, an initial negative gas decline rate. In this study, different coal compressibility models were developed based on the assumption that the deformation of a depleting coalbed is limited to the vertical direction, that is, the reservoir is under uniaxial strain conditions. Simultaneously, experimental work was carried out replicating these conditions. The results showed that the matrix volumetric strain typically follows the Langmuir-type relationship. The agreement between the experimental results and those obtained using the proposed model was good. The proposed volumetric strain model successfully isolated the sorption-induced strain from the strain resulting from mechanical compression. It, therefore, provides a technique to integrate the sorption-induced strain alone into different analytical permeability models. The permeability variation of coal with a decrease in pore pressure under replicated in situ stress/strain conditions was measured. The results showed that decreasing pore pressure resulted in a significant decrease in horizontal stress and increased permeability. The permeability increased non-linearly with decreasing pore pressure, with a small increase in the high pressure range, increasing progressively as the pressure dropped below a certain value. The experimental results were also used to test the proposed coupled sorption-induced strain model and several analytical permeability models. One of the commonly used models overestimated the permeability increase between

  16. Spatial Variability of Wet Troposphere Delays Over Inland Water Bodies

    Science.gov (United States)

    Mehran, Ali; Clark, Elizabeth A.; Lettenmaier, Dennis P.

    2017-11-01

    Satellite radar altimetry has enabled the study of water levels in large lakes and reservoirs at a global scale. The upcoming Surface Water and Ocean Topography (SWOT) satellite mission (scheduled launch 2020) will simultaneously measure water surface extent and elevation at an unprecedented accuracy and resolution. However, SWOT retrieval accuracy will be affected by a number of factors, including wet tropospheric delay—the delay in the signal's passage through the atmosphere due to atmospheric water content. In past applications, the wet tropospheric delay over large inland water bodies has been corrected using atmospheric moisture profiles based on atmospheric reanalysis data at relatively coarse (tens to hundreds of kilometers) spatial resolution. These products cannot resolve subgrid variations in wet tropospheric delays at the spatial resolutions (of 1 km and finer) that SWOT is intended to resolve. We calculate zenith wet tropospheric delays (ZWDs) and their spatial variability from Weather Research and Forecasting (WRF) numerical weather prediction model simulations at 2.33 km spatial resolution over the southwestern U.S., with attention in particular to Sam Rayburn, Ray Hubbard, and Elephant Butte Reservoirs which have width and length dimensions that are of order or larger than the WRF spatial resolution. We find that spatiotemporal variability of ZWD over the inland reservoirs depends on climatic conditions at the reservoir location, as well as distance from ocean, elevation, and surface area of the reservoir, but that the magnitude of subgrid variability (relative to analysis and reanalysis products) is generally less than 10 mm.

  17. Calculation of Interfacial Tensions of Hydrocarbon-water Systems under Reservoir Conditions

    DEFF Research Database (Denmark)

    Zuo, You-Xiang; Stenby, Erling Halfdan

    1998-01-01

    Assuming that the number densities of each component in a mixture are linearly distributed across the interface between the coexisting vapor-liquid or liquid-liquid phases, we developed in this research work a linear-gradient-theory (LGT) model for computing the interfacial tension of hydrocarbon......-brine systems. The new model was tested on a number of hydrocarbon-water/brine mixtures and two crude oil-water systems under reservoir conditions. The results show good agreement between the predicted and the experimental interfacial tension data.......Assuming that the number densities of each component in a mixture are linearly distributed across the interface between the coexisting vapor-liquid or liquid-liquid phases, we developed in this research work a linear-gradient-theory (LGT) model for computing the interfacial tension of hydrocarbon-water...... mixtures on the basis of the SRK equation of state. With this model, it is unnecessary to solve the time-consuming density-profile equations of the gradient-theory model. In addition, a correlation was developed for representing the effect of electrolytes on the interfacial tension of hydrocarbon...

  18. Calculation of Interfacial Tensions of Hydrocarbon-water Systems under Reservoir Conditions

    DEFF Research Database (Denmark)

    Zuo, You-Xiang; Stenby, Erling Halfdan

    1998-01-01

    Assuming that the number densities of each component in a mixture are linearly distributed across the interface between the coexisting vapor-liquid or liquid-liquid phases, we developed in this research work a linear-gradient-theory (LGT) model for computing the interfacial tension of hydrocarbon......-brine systems. The new model was tested on a number of hydrocarbon-water/brine mixtures and two crude oil-water systems under reservoir conditions. The results show good agreement between the predicted and the experimental interfacial tension data.......Assuming that the number densities of each component in a mixture are linearly distributed across the interface between the coexisting vapor-liquid or liquid-liquid phases, we developed in this research work a linear-gradient-theory (LGT) model for computing the interfacial tension of hydrocarbon......-water mixtures on the basis of the SRK equation of state. With this model, it is unnecessary to solve the time-consuming density-profile equations of the gradient-theory model. In addition, a correlation was developed for representing the effect of electrolytes on the interfacial tension of hydrocarbon...

  19. The effect of poling conditions on the performance of piezoelectric energy harvesters fabricated by wet chemistry

    KAUST Repository

    Fuentes-Fernandez, Erika Maria-Anai

    2015-03-25

    The effect of poling conditions on the power output of piezoelectric energy harvesters using sol-gel based Pb(Zr0.53,Ti0.47)O3-Pb(Zn1/3,Nb2/3)O3 piezoelectric thin-films has been investigated. A strong correlation was established between the poling efficiency and harvester output. A method based on simple capacitance-voltage measurements is shown to be an effective approach to estimate the power output of harvesters poled under different conditions. The poling process was found to be thermally activated with an activation energy of 0.12 eV, and the optimum poling conditions were identified (200 kV cm-1, 250 °C for 50 min). The voltage output and power density obtained under optimum poling conditions were measured to be 558 V cm-2 and 325 μW cm-2, respectively. © The Royal Society of Chemistry.2015.

  20. An experimental study on creep of partially molten granulite under high temperature and wet conditions

    Science.gov (United States)

    Zhou, Yongsheng; Zhang, Huiting; Yao, Wenming; Dang, Jiaxiang; He, Changrong

    2017-05-01

    Samples of natural granulite were deformed in a gas medium apparatus to evaluate the flow strength of the lower crust. The sample consists of ∼52 vol% plagioclase, ∼40 vol% pyroxene, ∼3 vol% quartz, ∼5 vol% magnetite and ilmenite. Water content was ∼0.17 ± 0.05 wt% in the deformed samples. 40 creep tests were performed on 13 samples at 300 MPa confining pressure, temperatures of 900-1200 °C, and strain rates between 3.13 × 10-6 and 5 × 10-5/s, resulting in axial stresses of 12-764 MPa and the total strain up to 7.8-20.5%. At low temperatures of 900-1000 °C, the microstructural observations show that the granulite samples were deformed in semi-brittle deformation regime, mainly by dislocation glide and intragranular microcracking. At medium temperatures (MT) of 1050-1100 °C, deformation was observed to be dominated by grain boundary migration recrystallization, corresponding to stress exponent nMT of 5.7 ± 0.1, activation energies QMT of 525 ± 34 kJ/mol, log AMT of 1.3. At high temperatures (HT) of 1125-1150 °C, the samples was deformed mainly by grain boundary migration recrystallization accommodated by partial melting and metamorphic reactions characterized by neo-crystallization of fine-grained olivine, with nHT of 4.8 ± 0.1, QHT of 1392 ± 63 kJ/mol, and log AHT of 37.5. Partial melting at high temperatures of 1125-1200 °C, which induces grain boundaries slip and enhances diffusion, has a significant weakening effect on the rheology of granulite, with an estimated strain rate enhancement by 5 times at melt fraction of ∼2 vol%. Reaction from pyroxene to olivine may affect the flow law parameters and deformation mechanism. Based on our data, a wet and cool continental lower crust may still be in brittle deformation regime, whereas a hot lower crust may likely have a weak layer with plastic deformation.

  1. Behavior of two phenyl urea herbicides in clayey soils and effect of alternating dry-wet conditions on their availability.

    Science.gov (United States)

    Haouari, Jamila; Dahchour, Abdelmalek; Peña-Heras, Arancha; Louchard, Xzavier; Lennartz, Berndt; Alaoui, Mohamed Elbelghiti; Satrallah, Ahmad

    2006-01-01

    Adsorption and mobility of linuron (3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea) and diuron (3-(3,4-dichlorophenyl)-1, 1-dimethylurea) were studied in clayey soils from the Gharb area (Morocco). Soils A and B were planted with sun flower (Helianthus annuus) while soil C was planted with sugar cane (Saccharum offcinarum). Adsorption was studied for linuron in soils A and B, while mobility was studied only in soil B. Adsorption data were found to fit the Freundlich equation with correlation coefficients r2 > 0.9. Freundlich coefficients (Kf, nf) were in agreement with L and S isotherm types for soils A and B, respectively. Values of Koc (195 and 102) indicate moderate adsorption. Desorption isotherms for linuron showed hysteresis for both soils. The pesticide would be more bound to soil A (H = 8.44) than to soil B (H = 4.01). The effect of alternating wet and dry conditions was tested for soils A and B. Results showed that retention would increase in soil subject to an additional wet and dry cycle. In the case of diuron isotherm was of type L in soil C. Desorption was noticeable at high concentrations and tended to decrease when concentrations diminished. Mobility of linuron was tested in polyvinyle chloride (PVC) columns, which received different treatments before their percolation. The pesticide was more mobile in a previously saturated column. In columns subject to a drying step after saturation with water, linuron mobility was greatly reduced.

  2. Antecedent growth conditions alter retention of environmental Escherichia coli isolates in transiently wetted porous media

    DEFF Research Database (Denmark)

    Yang, H.-H.; Morrow, J. B.; Grasso, D.

    2008-01-01

    retentive capacity, may present one such approach. Eight environmental E coli isolates were selected to conduct operational retention tests (ORT) with potential biobarrier materials Pyrax or dolomite, or silica glass as control. The conditions in the ORT were chosen to simulate conditioning by manure......The physical transport of Escherichia coli in terrestrial environments may require control to prevent its dissemination from potential high-density sources, such as confined animal feedlot operations. Biobarriers, wherein convective flows carrying pathogens pass through a porous matrix with high...... solutes, a pulse application of a bacterial load followed by rainfall infiltration, and natural drainage. Removal was limited, and likely caused by the relatively high velocities during drainage, and the conditioning of otherwise favorable adhesion sites. Flagella-mediated motility showed the strongest...

  3. Wet Belly in Reindeer (Rangifer tarandus tarandus in Relation to Body Condition, Body Temperature and Blood Constituents

    Directory of Open Access Journals (Sweden)

    Olsson K

    2002-06-01

    Full Text Available Wet belly, when the reindeer becomes wet over the lower parts of the thorax and abdomen, sometimes occurs in reindeer during feeding. In a feeding experiment, 11 out of 69 reindeer were affected by wet belly. The problem was first observed in 7 animals during a period of restricted feed intake. When the animals were then fed standard rations, 3 additional animals fed only silage, and 1 fed pellets and silage, became wet. Four animals died and 1 had to be euthanised. To investigate why reindeer developed wet belly, we compared data from healthy reindeer and reindeer affected by wet belly. Urea, plasma protein, glucose, insulin and cortisol were affected by restricted feed intake or by diet but did not generally differ between healthy reindeer and those with wet belly. The wet animals had low body temperature and the deaths occurred during a period of especially cold weather. Animals that died were emaciated and showed different signs of infections and stress. In a second experiment, with 20 reindeer, the feeding procedure of the most affected group in the first experiment was repeated, but none of the reindeer showed any signs of wet belly. The study shows that wet belly is not induced by any specific diet and may affect also lichen-fed reindeer. The fluid making the fur wet was proven to be of internal origin. Mortality was caused by emaciation, probably secondary to reduced energy intake caused by diseases and/or unsuitable feed.

  4. Sedimentary tectonic evolution and reservoir-forming conditions of the Dazhou–Kaijiang paleo-uplift, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Yueming Yang

    2016-12-01

    Full Text Available Great breakthrough recently achieved in the Sinian–Lower Paleozoic gas exploration in the Leshan–Longnüsi paleo-uplift, Sichuan Basin, has also made a common view reached, i.e., large-scale paleo-uplifts will be the most potential gas exploration target in the deep strata of this basin. Apart from the above-mentioned one, the other huge paleo-uplifts are all considered to be the ones formed in the post-Caledonian period, the impact of which, however, has rarely ever been discussed on the Sinian–Lower Paleozoic oil and gas reservoir formation. In view of this, based on outcrops, drilling and geophysical data, we analyzed the Sinian–Lower Paleozoic tectonic setting and sedimentary background in the East Sichuan Basin, studied the distribution rules of reservoirs and source rocks under the control of paleo-uplifts, and finally discussed, on the basis of structural evolution analysis, the conditions for the formation of Sinian–Lower Paleozoic gas reservoirs in this study area. The following findings were achieved. (1 The Dazhou–Kaijiang inherited uplift in NE Sichuan Basin which was developed before the Middle Cambrian controlled a large area of Sinian and Cambrian beach-facies development. (2 Beach-facies reservoirs were developed in the upper part of the paleo-uplift, while in the peripheral depression belts thick source rocks were developed like the Upper Sinian Doushantuo Fm and Lower Cambrian Qiongzhusi Fm, so there is a good source–reservoir assemblage. (3 Since the Permian epoch, the Dazhou–Kaijiang paleo-uplift had gradually become elevated from the slope zone, where the Permian oil generation peak occurred in the slope or lower and gentle uplift belts, while the Triassic gas generation peak occurred in the higher uplift belts, both with a favorable condition for hydrocarbon accumulation. (4 The lower structural layers, including the Lower Cambrian and its underlying strata, in the East Sichuan Basin, are now equipped with a

  5. A field experiment on microwave forest radiometry: L-band signal behaviour for varying conditions of surface wetness

    DEFF Research Database (Denmark)

    Grant, J. P.; Wigneron, J. P.; Van de Grind, A. A.

    2007-01-01

    France, using a multi-angle L-band (1.4 GHz) radiometer to measure from above the forest at horizontal polarization. At the same time, ground measurements were taken of soil and litter moisture content, while precipitation was also permanently monitored. This experiment was done in the context...... of the upcoming SMOS mission in order to improve our understanding of the behaviour of the L-band signal from forested areas for different wetness conditions and viewing angles. This is especially relevant for solving the problem of heterogeneity since a large fraction of SMOS pixels (~30x30 km²) is partially...... covered by forest. This paper describes the objectives and the overall set-up of the Bray-2004 experiment and shows some first results. The greater part of the horizontally polarized L-band signal is found to be dominated by the influence of physical temperature. Variations in soil and/or litter moisture...

  6. Reaction kinetics of hydrazine neutralization in steam generator wet lay-up solution: Identifying optimal degradation conditions

    International Nuclear Information System (INIS)

    Schildermans, Kim; Lecocq, Raphael; Girasa, Emmanuel

    2012-09-01

    During a nuclear power plant outage, hydrazine is used as an oxygen scavenger in the steam generator lay-up solution. However, due to the carcinogenic effects of hydrazine, more stringent discharge limits are or will be imposed in the environmental permits. Hydrazine discharge could even be prohibited. Consequently, hydrazine alternatives or hydrazine degradation before discharge is needed. This paper presents the laboratory tests performed to characterize the reaction kinetics of hydrazine neutralization using bleach or hydrogen peroxide, catalyzed with either copper sulfate (CuSO 4 ) or potassium permanganate (KMnO 4 ). The tests are performed on two standard steam generator lay-up solutions based on different pH control agents: ammonia or ethanolamine. Different neutralization conditions are tested by varying temperature, oxidant addition, and catalyst concentration, among others, in order to identify the optimal parameters for hydrazine neutralization in a steam generator wet lay-up solution. (authors)

  7. Effect of wet-cold weather transportation conditions on thermoregulation and the development of accidental hypothermia in pullets under tropical conditions

    Science.gov (United States)

    Minka, Ndazo S.; Ayo, Joseph O.

    2016-03-01

    The present study examines onboard thermal microclimatic conditions and thermoregulation of pullets exposed to accidental hypothermia during wet-cold weather transportation conditions, and the effect of rewarming on colonic temperature (CT) of the birds immediately after transportation. A total of 2200 pullets were transportation for 5 h in two separate vehicles during the nighttime. The last 3 h of the transportation period was characterized by heavy rainfall. During the precipitation period, each vehicle was covered one fourth way from the top-roof with a tarpaulin. The onboard thermal conditions inside the vehicles during transportation, which comprised ambient temperature and relative humidity were recorded, while humidity ratio and specific enthalpy were calculated. The CT of the birds was recorded before and after transportation. During transportation, onboard thermal heterogeneity was observed inside the vehicles with higher ( p < 0.05) values in the front and center, and lower values recorded at the air inlets at the sides and rear planes. The CT values recorded in birds at the front and center planes were between 42.2 and 42.5 °C, indicative of mild hypothermia; while lower CT values between 28 and 38 °C were recorded at the sides and rear planes, indicative of mild to severe hypothermia. Several hours of gradual rewarming returned the CT to normal range. The result, for the first time, demonstrated the occurrence of accidental hypothermia in transported pullets under tropical conditions and a successful rewarming outcome. In conclusion, transportation of pullets during wet weather at onboard temperature of 18-20 °C induced hypothermia on birds located at the air inlets, which recovered fully after several hours of gradual rewarming.

  8. Computer code (WETBERAN) for wet sequence behavior of radioactive nuclides in LWR plant at accident conditions

    International Nuclear Information System (INIS)

    Shimooke, T.; Kobayashi, K.; Sato, S.

    1985-01-01

    The WETBERAN code has been developed to simulate the isotopic- and time-dependent behaviors of fission products (FP) which leak through the multiple paths of liquid and gas flows within LWR plant under accident conditions. In this code, emphasis is put on the phenomena pertinent to the presence of water. The TMI, SL-1 and Ginna accidents were analyzed to show the code capability. The TMI 40 day analysis gave detailed information of FP behaviors, both leaking from and remaining in the plant, and proved effectiveness of the network model describing the multiple leakage paths. The SL-1 analysis was made to study halogen reduction by water, which cannot be taken into account by CORRAL. The Ginna analysis was to check the iodine transport by droplets usually generated by primary water flashing at SG tube rupture

  9. Technical Note: Quantification of interferences of wet chemical HONO LOPAP measurements under simulated polar conditions

    Directory of Open Access Journals (Sweden)

    J. Kleffmann

    2008-11-01

    Full Text Available In the present pilot study, an optimized LOPAP instrument (LOng Path Absorption Photometer for the detection of nitrous acid (HONO in the atmosphere (DL 0.2 pptV was tested at the high alpine research station Jungfraujoch at 3580 m altitude in the Swiss Alps under conditions comparable to polar regions. HONO concentrations in the range <0.5–50 pptV with an average of 7.5 pptV were observed at the Jungfraujoch. The diurnal profiles obtained exhibited clear maxima at noon and minima with very low concentration during the night supporting the proposed photochemical production of HONO. In good agreement with recent measurements at the South Pole, it was demonstrated, that interferences of chemical HONO instruments can significantly influence the measurements and lead to considerable overestimations, especially for low pollution level. Accordingly, the active correction of interferences is of paramount importance for the determination of reliable HONO data.

  10. Relationship between Amount of Exited Blood During Wet-cupping with Patient’s Individual Conditions and the Time of Doing it

    Directory of Open Access Journals (Sweden)

    Ghazanfari M

    2017-12-01

    Full Text Available Aims Wet-cupping as a therapeutic method has been recommended to be done on certain days based on authentic sources of traditional medicine in Iran. The purpose of this study was to determine the relationship between amount of exited blood during wet-cupping with patient’s individual conditions and the time it was performed. Instruments & Methods In this descriptive cross-sectional study, 391 men who were referred to a cupping center in Saveh city in the spring of 2016, were selected by simple sampling and wet-cupping in the position between the two scapula was performed. The research instrument was a questionnaire including demographic characteristics, date of reference (day, month and year, age, height, weight and amount of exited blood during the wet-cupping in gram. Data were analyzed by SPSS 16 software and using chi-square test, paired t test and one-way analysis of variance. Findings The means of age, weight and body mass index were significantly related to the mean of amount of exited blood during wet-cupping (p0.05, but the amount of exited blood was higher in people with previous history of wet-cupping than those without previous history (p<0.001. Also, in people with hypertension, the amount of exited blood was higher than other treatment groups (p<0.05. Conclusion Individual characteristics such as age, weight, body mass index, cause of referral and previous history of wet-cupping affect the amount of exited blood during wet-cupping, but the time of wet-cupping (day and month does not affect the amount of exited blood.

  11. Stabilized oil production conditions in the development equilibrium of a water-flooding reservoir

    Directory of Open Access Journals (Sweden)

    Renshi Nie

    2016-12-01

    Full Text Available Water injection can compensate for pressure depletion of production. This paper firstly investigated into the equilibrium issue among water influx, water injection and production. Equilibrium principle was elaborated through deduction of equilibrium equation and presentation of equilibrium curves with an “equilibrium point”. Influences of artificial controllable factors (e.g. well ratio of injection to production and total well number on equilibrium were particularly analyzed using field data. It was found that the influences were mainly reflected as the location move of equilibrium point with factor change. Then reservoir pressure maintenance level was especially introduced to reveal the variation law of liquid rate and oil rate with the rising of water cut. It was also found that, even if reservoir pressure kept constant, oil rate still inevitably declined. However, in the field, a stabilized oil rate was always pursued for development efficiency. Therefore, the equilibrium issue of stabilized oil production was studied deeply through probing into some effective measures to realize oil rate stability after the increase of water cut for the example reservoir. Successful example application indicated that the integrated approach was very practical and feasible, and hence could be used to the other similar reservoir.

  12. Effects of evaporative cooling on reproductive performance and milk production of dairy cows in hot wet conditions

    Science.gov (United States)

    Khongdee, S.; Chaiyabutr, N.; Hinch, G.; Markvichitr, K.; Vajrabukka, C.

    2006-05-01

    Fourteen animals of second and third lactation of Thai Friesian crossbred cows (87.5% Friesian × 12.5% Bos indicus) located at Sakol Nakhon Research and Breeding Centre, Department of Livestock Development, Ministry of Agriculture and Cooperatives, were divided randomly into two groups of seven each to evaluate the effects of evaporative cooling on reproductive and physiological traits under hot, humid conditions. Results indicated that installation of evaporating cooling in the open shed gave a further improvement in ameliorating heat stress in dairy cows in hot-wet environments by utilising the low humidity conditions that naturally occur during the day. The cows housed in an evaporatively cooled environment had both a rectal temperature and respiration rate (39.09°C, 61.39 breaths/min, respectively) significantly lower than that of the non-cooled cows (41.21°C; 86.87 breaths/min). The former group also had higher milk yield and more efficient reproductive performance (pregnancy rate and reduced days open) than the latter group. It is suggested that the non-evaporatively cooled cows did not gain benefit from the naturally lower heat stress during night time.

  13. Smolt Condition and Timing of Arrival at Lower Granite Reservoir, 1987 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Nelson, V. Lance

    1990-01-01

    This project monitored the daily passage of smolts during the 1988 spring outmigration at two migrant traps; one each on the Snake and Clearwater rivers. Due to the low runoff year, chinook salmon catch at the Snake River trap was very low. Steelhead trout catch was higher than normal, probably due to trap modifications and because the trap was moved to the east side of the river. Chinook salmon and steelhead trout catch at the Clearwater River trap was similar to 1987. Total cumulative recovery of PIT tagged fish at the three dams, with PIT tag detection systems was: 55% for chinook salmon, 73% for hatchery steelhead trout, and 75% for wild steelhead trout. Travel time through Lower Granite Reservoir for PIT tagged chinook salmon and steelhead trout, marked at the head of the reservoir, was affected by discharge. Statistical analysis showed that as discharge increased from 40 kcfs to 80 kcfs, chinook salmon travel time decreased three fold, and steelhead trout travel time decreased two fold. There was a statistical difference between estimates of travel time through Lower Granite Reservoir for PIT tagged and freeze branded steelhead trout, but not for chinook salmon. These differences may be related to the estimation techniques used for PIT tagged and freeze branded groups, rather than real differences in travel time. 10 figs, 15 tabs.

  14. Smolt Condition and Timing of Arrival at Lower Granite Reservoir, 1988 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Nelson, William R.

    1989-10-01

    This project monitored the daily passage of smelts during the 1988 spring outmigration at two migrant traps; one each on the Snake and Clear-water rivers. Due to the low runoff year, chinook salmon catch at the Snake River trap was very low. Steelhead trout catch was higher than normal, probably due to trap modifications and because the trap was moved to the east side of the river. Chinook salmon and steelhead trout catch at the Clearwater River trap was similar to 1987. Total cumulative recovery of PIT tagged fish at the three dams, with PIT tag detection systems was: 55% for chinook salmon, 73% for hatchery steelhead trout, and 75% for wild steelhead trout. Travel time through Lower Granite Reservoir for PIT tagged chinook salmon and steelhead trout, marked at the head of the reservoir, was affected by discharge. Statistical analysis showed that as discharge increased from 40 kcfs to 80 kcfs, chinook salmon travel time decreased three fold, and steelhead trout travel time decreased two fold. There was a statistical difference between estimates of travel time through Lower Granite Reservoir for PIT tagged and freeze branded steelhead trout, but not for chinook salmon. These differences may be related to the estimation techniques used for PIT tagged and freeze branded groups, rather than real differences in travel time.

  15. Three Gorges Reservoir Area: soil erosion under natural condition vs. soil erosion under current land use

    Science.gov (United States)

    Schönbrodt, Sarah; Behrens, Thorsten; Scholten, Thomas

    2010-05-01

    Apparently, the current most prominent human-induced example for large scale environmental impact is the Three Gorges Dam in China. The flooding alongside the Yangtze River, and its tributaries results in a vast loss of settlement and farmland area with productive, fertile valley soils. Due to the associated high land use dynamic on uphill-sites, the soil resources are underlying high land use pressure. Within our study, the soil erosion under natural conditions is compared to the soil erosion under current land use after the impoundment. Both were modeled using the empirical Universal Soil Loss Equation (USLE) which is able to predict long-term annual soil loss with limited data. The database consists of digital terrain data (45 m resolution DEM, erosive slope length based on Monte-Carlo-Aggregation according to Behrens et al. (2008)), field investigations of recent erosion forms, and literature studies. The natural disposition to soil erosion was calculated considering the USLE factors R, S, and K. The soil erosion under current land use was calculated taking into account all USLE factors. The study area is the catchment of the Xiangxi River in the Three Gorges Reservoir area. Within the Xiangxi Catchment (3,200 km²) the highly dynamic backwater area (580 km²), and two micro-scale study sites (Xiangjiaba with 2.8 km², and Quyuan with 88 km²) are considered more detailed as they are directly affected by the river impoundment. Central features of the Xiangxi Catchment are the subtropical monsoon climate, an extremely steep sloping relief (mean slope angle 39°, SD 22.8°) artificially fractured by farmland terraces, and a high soil erodibility (mean K factor 0.37, SD 0.13). On the catchment scale the natural disposition to soil erosion makes up to mean 518.0 t ha-1 a-1. The maximum potential soil loss of 1,730.1 t ha-1 a-1 under natural conditions is reached in the Quyuan site (mean 635.8 t ha-1 a-1) within the backwater area (mean 582.9 t ha-1 a-1). In the

  16. Effects of impoundment on the body condition of fish in the Manso reservoir, Mato Grosso State, Brazil

    Directory of Open Access Journals (Sweden)

    Sandra Maria Lopes de Moura

    2014-12-01

    Full Text Available AIM: This study evaluated the body condition de Acestrorhynchus pantaneiro, Auchenipterus osteomystax, Pimelodus maculatus, Psectrogaster curviventris and Schizodon borellii in the Manso reservoir, Mato Grosso State, Brazil, during the first years after its formation (years I, II, III and IV. We hypothesized that sudden environmental changes alter differently the body condition, according to the time (sampling years and sex of individuals. Also, we checked the influence of the amount of food ingested and the reproductive status on nutritional status of the species. METHODS: The body condition (Kn, the feeding activity (SRI and reproductive (GSI were calculated only for adults. The difference between the sampling years and sexes (used as factors was assessed using the nonparametric Kruskal-Wallis test. Temporal influence was tested by Spearman correlation and the interaction between both factors by PERMANOVA. RESULTS: The values of the Kn showed two groups: group 1: species whose body condition decreased in the year II, with a posterior increase (A. pantaneiro, P. curviventris and S. borelli, considered sensitive to the reservoir filling; group 2: species whose body condition increased in the year II (A. osteomystax and P. maculatus, indicating a more rapid adaptation to new environmental conditions. Still, all parameters investigated were somehow affected by the dam, mainly the body condition and gonadosomatic index for several species. On the other hand, the least affected factor was the feeding activity. CONCLUSIONS: The results did not evidence a same pattern of either increase or decrease of body condition for all species examined, since everything indicates that responses are species-specific. Even with a lack of consistency in some results, we can draw some suggestions for future investigations. Responses to these questions will certainly contribute to aggregate data to help better explain the body condition of fish species in dammed

  17. Chemical and physical reservoir parameters at initial conditions in Berlin geothermal field, El Salvador: a first assessment

    Energy Technology Data Exchange (ETDEWEB)

    D`Amore, F. [CNR, Pisa (Italy). International Institute for Geothermal Research ; Mejia, J.T. [Comision Ejuctiva Hidroelectrica del Rio Lempa, El Salvador (El Salvador)

    1999-02-01

    A study has been made to obtain the main chemical and physical reservoir conditions of the Berlin field (El Salvador), before the commencement of large-scale exploitation of the geothermal resource. The upflow zone and the main flow path within the geothermal system have been determined from the area distribution of chemical parameters such as Cl concentrations, ratios such as Na/K, K/Mg, K/Ca, and temperatures computed from silica concentrations and cation ratios. Gas compositions have been used to calculate reservoir parameters such as temperature, steam fraction and P{sub CO{sub 2}}. The computer code WATCH (new edition 1994) has been used to evaluate the temperature of equilibrium between the aqueous species and selected alteration minerals in the reservoir. The fluid in Berlin flows to the exploited reservoir from the south, entering it in the vicinity of well TR-5. Along its flow-path (south-north direction), the fluid is cooled by boiling and conductive cooling. The chloride-enthalpy diagram indicates the existence of a parent water, with a chemical composition similar to well TR-5, that boils and the residual brine produces the fluid of well TR-3, which is very concentrated in salts. The fluid of TR-5 is probably produced from this parent water, generating the fluids of wells TR-2 and TR-9 by boiling, and the fluids of wells TR-1 and TR-4 by conductive cooling. The computed values for the deep steam fraction clearly indicate that this is a liquid-dominated system, with computed temperature values decreasing from 310{sup o}C (upflow zone) to about 230{sup o}C, from south to north. (author)

  18. Smolt Condition and Timing of Arrival at Lower Granite Reservoir, 1985 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Scully, Richard J.; Buettner, Edwin W.

    1986-08-01

    This project monitored the daily passage of smolts during the 1985 spring outmigration at three migrant traps, one each on the Snake, Clearwater, and Salmon rivers. Yearling chinook migration rate between Salmon River release sites and the Salmon River scoop trap averaged 23 km per day, about half the migration rate for the same brand groups when migrating from the Salmon River trap to the Snake River trap (48 km/day). Average migration rates for branded chinook and steelhead between release sites and the head of Lower Granite Reservoir were both near 27 km per day. The yearling chinook migration begins in earnest when Salmon River discharge makes a significant rise in early to mid-April. Most yearling chinook pass into Lower Granite Reservoir in April followed by passage of steelhead in May. Chinook smolt recapture data from the Snake River trap suggest a strong dependence of migration rate on quantity of Snake and Salmon river discharge. The ability of the Salmon River trap to catch yearling chinook decreased as discharge increased. No correlation between discharge level and efficiency was observed at the Snake or Clearwater trap for chinook or steelhead smolts. When comparing the size of smolts in the Salmon and Clearwater rivers, the former river has smaller yearling chinook and larger hatchery and wild steelhead. Salmon River hatchery steelhead smolts in 1985 averaged 2 cm smaller than in 1983 and were much healthier than in 1983. 4 refs., 32 figs., 18 tabs.

  19. Smolt Condition and Timing of Arrival at Lower Granite Reservoir, 1986 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Buettner, Edwin W.; Nelson, V. Lance

    1987-09-01

    This project monitored the daily passage of smolts during the 1986 spring outmigration at two migrant traps, one each on the Snake and Clearwater rivers. Average migration rates for freeze-branded chinook salmon smolts were 28.2 km per day and 22.1 km per day for steelhead trout smolts between release sites and the head of Lower Granite Reservoir. The yearling chinook salmon migration begins in earnest when Salmon River discharge makes a significant rise in early to mid-April. Most yearling chinook salmon pass into Lower Granite Reservoir in April followed by passage of steelhead trout in May. Chinook salmon smolt recapture data from the Snake River trap suggest a strong dependence of migration rate on quantity of Snake and Salmon River discharge, although no statistical correlation exists at this time. Daily and seasonal descaling rates were calculated for each species at each trap. Rates were highest for hatchery steelhead trout, intermediate for yearling chinook salmon, and lowest for wild steelhead trout. Descaling rates were generally higher in 1986 than those observed in 1984 and 1985. 4 refs., 9 figs., 15 tabs.

  20. Operation of Dokan Reservoir under Stochastic Conditions as Regards the Inflows and the Energy Demands

    Science.gov (United States)

    Rashed, G. I.

    2018-02-01

    This paper presented a way of obtaining certain operating rules on time steps for the management of a large reservoir operation with a peak hydropower plant associated to it. The rules were allowed to have the form of non-linear regression equations which link a decision variable (here the water volume in the reservoir at the end of the time step) by several parameters influencing it. This paper considered the Dokan hydroelectric development KR-Iraq, which operation data are available for. It was showing that both the monthly average inflows and the monthly power demands are random variables. A model of deterministic dynamic programming intending the minimization of the total amount of the squares differences between the demanded energy and the generated energy is run with a multitude of annual scenarios of inflows and monthly required energies. The operating rules achieved allow the efficient and safe management of the operation and it is quietly and accurately known the forecast of the inflow and of the energy demand on the next time step.

  1. Dokan Hydropower Reservoir Operation under Stochastic Conditions as Regards the Inflows and the Energy Demands

    Science.gov (United States)

    Izat Rashed, Ghamgeen

    2018-03-01

    This paper presented a way of obtaining certain operating rules on time steps for the management of a large reservoir operation with a peak hydropower plant associated to it. The rules were allowed to have the form of non-linear regression equations which link a decision variable (here the water volume in the reservoir at the end of the time step) by several parameters influencing it. This paper considered the Dokan hydroelectric development KR-Iraq, which operation data are available for. It was showing that both the monthly average inflows and the monthly power demands are random variables. A model of deterministic dynamic programming intending the minimization of the total amount of the squares differences between the demanded energy and the generated energy is run with a multitude of annual scenarios of inflows and monthly required energies. The operating rules achieved allow the efficient and safe management of the operation and it is quietly and accurately known the forecast of the inflow and of the energy demand on the next time step.

  2. Analysis of Geothermal Reservoir and Well Operational Conditions using Monthly Production Reports from Nevada and California

    Energy Technology Data Exchange (ETDEWEB)

    Beckers, Koenraad J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Young, Katherine R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Johnston, Henry [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Snyder, Diana M. [Georgia State University

    2017-10-04

    When conducting techno-economic analysis of geothermal systems, assumptions are typically necessary for reservoir and wellbore parameters such as producer/injector well ratio, production temperature drawdown, and production/injection temperature, pressure and flow rate. To decrease uncertainty of several of these parameters, we analyzed field data reported by operators in monthly production reports. This paper presents results of a statistical analysis conducted on monthly production reports at 19 power plants in California and Nevada covering 196 production wells and 175 injection wells. The average production temperature was 304 degrees F (151 degrees C) for binary plants and 310 degrees F (154 degrees C) for flash plants. The average injection temperature was 169 degrees F (76 degrees C) for binary plants and 173 degrees F (78 degrees C) for flash plants. The average production temperature drawdown was 0.5% per year for binary plants and 0.8% per year for flash plants. The average production well flow rate was 112 L/s for binary plant wells and 62 L/s for flash plant wells. For all 19 plants combined, the median injectivity index value was 3.8 L/s/bar, and the average producer/injector well ratio was 1.6. As an additional example of analysis using data from monthly production reports, a coupled reservoir-wellbore model was developed to derive productivity curves at various pump horsepower settings. The workflow and model were applied to two example production wells.

  3. Anaerobic digestion performance of sweet potato vine and animal manure under wet, semi-dry, and dry conditions.

    Science.gov (United States)

    Zhang, Enlan; Li, Jiajia; Zhang, Keqiang; Wang, Feng; Yang, Houhua; Zhi, Suli; Liu, Guangqing

    2018-03-22

    Sweet potato vine (SPV) is an abundant agricultural waste, which is easy to obtain at low cost and has the potential to produce clean energy via anaerobic digestion (AD). The main objectives of this study were to reveal methane production and process stability of SPV and the mixtures with animal manure under various total solid conditions, to verify synergetic effect in co-digestion of SPV and manure in AD systems, and to determine the kinetics characteristics during the full AD process. The results showed that SPV was desirable feedstock for AD with 200.22 mL/g VS added of methane yield in wet anaerobic digestion and 12.20 L methane /L working volume in dry anaerobic digestion (D-AD). Synergistic effects were found in semi-dry anaerobic digestion and D-AD with each two mixing feedstock. In contrast with SPV mono-digestion, co-digestion with manure increased methane yield within the range of 14.34-49.11% in different AD digesters. The values of final volatile fatty acids to total alkalinity (TA) were below 0.4 and the values of final pH were within the range of 7.4-8.2 in all the reactors, which supported a positive relationship between carbohydrate hydrolysis and methanogenesis during AD process. The mathematical modified first order model was applied to estimate substrate biodegradability and methane production potential well with conversion constant ranged from 0.0003 to 0.0953 1/day, which indicated that co-digestion increased hydrolysis efficiency and metabolic activity. This work provides useful information to improve the utilization and stability of digestion using SPV and livestock or poultry manure as substrates.

  4. Length-weight relationship and condition factor of Macrobrachium amazonicum (Heller, 1862 (Decapoda, Palaemonidae from a reservoir in Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Sérgio Schwarz da Rocha

    Full Text Available ABSTRACT Macrobrachium amazonicum (Heller, 1862 is a freshwater prawn occurring in rivers and reservoirs of Central and South America. Given its broad geographical distribution, the species shows great intraspecific morphological, reproductive, physiological and ecological plasticity. Furthermore, it also stands out for its economic importance, especially in the states of North (Pará and Amapá and Northeast Brazil. Despite the wide geographic distribution and economic importance of M. amazonicum, the biology of this species is poorly known, particularly in Northeast Brazil. We analyzed the length-weight relationships and condition factor of males and females of M. amazonicum. Specimens were collected monthly from September 2008 to August 2009 at the Pedra do Cavalo Reservoir, city of Cabaceiras do Paraguaçu, State of Bahia. All specimens were sexed, measured and weighted. After that, length-weight relationships and the allometric (K and relative (Kr condition factors were calculated. Altogether 2,974 specimens were analyzed, 334 of which were males (11% and 2,640 were females (89%. Females were larger and heavier than males. Males and females showed isometric and negative allometric growth, respectively. Monthly variations in the condition factor were similar for both sexes, and correlated strongly with rainfall regime and temperature in the region. Such variations are not correlated with the reproductive cycle of the species, but are probably correlated with food availability and somatic growth.

  5. Wet oxidation of quinoline

    DEFF Research Database (Denmark)

    Thomsen, A.B.; Kilen, H.H.

    1998-01-01

    The influence of oxygen pressure (0.4 and 2 MPa). reaction time (30 and 60 min) and temperature (260 and 280 degrees C) on the wet oxidation of quinoline has been studied. The dominant parameters for the decomposition of quinoline were oxygen pressure and reaction temperature. whereas the reaction...... time was less important within the range studied. Nitrifying bacteria were used to measure the inhibition from wet oxidative-treated samples to study the effect of the (wet oxidation) reaction conditions. Wet oxidation made quinoline more toxic to Nitrosomonas. This was observed for Nitrobacter as well....... The combined wet oxidation and biological treatment of reaction products resulted in 91% oxidation of the parent compound to CO2 and water. Following combined wet oxidation and biological treatment the sample showed low toxicity towards Nitrosomonas and no toxicity towards Nitrobacter. (C) 1998 Elsevier...

  6. Optical properties of a tropical estuary during wet and dry conditions in the Nha Phu estuary, Khanh Hoa Province, south-east Vietnam

    DEFF Research Database (Denmark)

    Lund-Hansen, Lars Chresten; Hai, Doan Nhu; Lam, Nguyen Ngoc

    2010-01-01

    into the estuary. This complied with a residence time of four and a half days derived from a basic physical relation. Optical properties were in general comparable to temperate estuaries in dry conditions although Chl a concentrations were lower in Nha Phu. A second distinctive point, as compared to temperate...... properties in a tropical wet and dry estuary are compared and discussed in relation to those of temperate estuaries. Sampling in the Nha Phu estuary, Vietnam, consisted of five stations on a transect from head to mouth that was sampled four times during dry conditions and three times during wet conditions...... with high values at the head and lower in the central part of the estuary. The depth of the photic zone was reduced by up to 50% during wet conditions. A residence time in the estuary of 5–6 days was derived from the rate of change of K d(PAR) after a period of heavy rain and discharge of freshwater...

  7. Scoping Summary Report: Development of Lower Basin Shortage Guidelines and Coordinated Management Strategies for Lake Powell and Lake Mead, Particularly Under Low Reservoir Conditions

    OpenAIRE

    U.S. Department of the Interior, Bureau of Reclamation

    2006-01-01

    The Bureau of Reclamation (Reclamation) acting on behalf of the Secretary of the Department of the Interior (Secretary) proposes to take action to adopt specific Colorado River Lower Basin shortage guidelines and coordinated reservoir management strategies to address operations of Lake Powell and Lake Mead, particularly under low reservoir conditions. This proposed Action will provide a greater degree of certainty to all water users and managers in the Colorado River Basin by providing more d...

  8. Accumulation conditions and enrichment patterns of natural gas in the Lower Cambrian Longwangmiao Fm reservoirs of the Leshan-Longnǚsi Palaeohigh, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Xu Chunchun

    2014-10-01

    Full Text Available As several major new gas discoveries have been made recently in the Lower Cambrian Longwangmiao Fm reservoirs in the Leshan-Longnǚsi Palaeohigh of the Sichuan Basin, a super-huge gas reservoir group with multiple gas pay zones vertically and cluster reservoirs laterally is unfolding in the east segment of the palaeohigh. Study shows that the large-scale enrichment and accumulation of natural gas benefits from the good reservoir-forming conditions, including: (1 multiple sets of source rocks vertically, among which, the high-quality Lower Paleozoic source rocks are widespread, and have a hydrocarbon kitchen at the structural high of the Palaeohigh, providing favorable conditions for gas accumulation near the source; (2 three sets of good-quality reservoirs, namely, the porous-vuggy dolomite reservoirs of mound-shoal facies in the 2nd and 4th members of the Sinian Dengying Fm as well as the porous dolomite reservoirs of arene-shoal facies in the Lower Cambrian Longwangmiao Fm, are thick and wide in distribution; (3 structural, lithological and compound traps developed in the setting of large nose-like uplift provide favorable space for hydrocarbon accumulation. It is concluded that the inheritance development of the Palaeohigh and its favorable timing configuration with source rock evolution are critical factors for the extensive enrichment of gas in the Lower Cambrian Longwangmiao Fm reservoirs. The structural high of the Palaeohigh is the favorable area for gas accumulation. The inherited structural, stratigraphic and lithological traps are the favorable sites for gas enrichment. The areas where present structures and ancient structures overlap are the sweet-spots of gas accumulation.

  9. Status of Wheeler Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-01

    This is one in a series of status reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Wheeler Reservoir summarizes reservoir purposes and operation, reservoir and watershed characteristics, reservoir uses and use impairments, and water quality and aquatic biological conditions. The information presented here is from the most recent reports, publications, and original data available. If no recent data were available, historical data were summarized. If data were completely lacking, environmental professionals with special knowledge of the resource were interviewed. 12 refs., 2 figs.

  10. Wettability of supercritical carbon dioxide/water/quartz systems: simultaneous measurement of contact angle and interfacial tension at reservoir conditions.

    Science.gov (United States)

    Saraji, Soheil; Goual, Lamia; Piri, Mohammad; Plancher, Henry

    2013-06-11

    Injection of carbon dioxide in deep saline aquifers is considered as a method of carbon sequestration. The efficiency of this process is dependent on the fluid-fluid and rock-fluid interactions inside the porous media. For instance, the final storage capacity and total amount of capillary-trapped CO2 inside an aquifer are affected by the interfacial tension between the fluids and the contact angle between the fluids and the rock mineral surface. A thorough study of these parameters and their variations with temperature and pressure will provide a better understanding of the carbon sequestration process and thus improve predictions of the sequestration efficiency. In this study, the controversial concept of wettability alteration of quartz surfaces in the presence of supercritical carbon dioxide (sc-CO2) was investigated. A novel apparatus for measuring interfacial tension and contact angle at high temperatures and pressures based on Axisymmetric Drop Shape Analysis with no-Apex (ADSA-NA) method was developed and validated with a simple system. Densities, interfacial tensions, and dynamic contact angles of CO2/water/quartz systems were determined for a wide range of pressures and temperatures relevant to geological sequestration of CO2 in the subcritical and supercritical states. Image analysis was performed with ADSA-NA method that allows the determination of both interfacial tensions and contact angles with high accuracy. The results show that supercritical CO2 alters the wettability of quartz surface toward less water-wet conditions compared to subcritical CO2. Also we observed an increase in the water advancing contact angles with increasing temperature indicating less water-wet quartz surfaces at higher temperatures.

  11. Comparison of Clinical Success of Applying a Kind of Fissure Sealant on the Lower Permanent Molar Teeth in Dry and Wet Conditions.

    Science.gov (United States)

    Eskandarian, Tahereh; Baghi, Saeid; Alipoor, Abbas

    2015-09-01

    Fissure sealant therapy is among the most effective methods of preventing dental caries. However, it is lengthy and isolation of the teeth is difficult in this procedure especially in young children. Using new hydrophilic fissure sealant may reduce such problems. This study aimed to evaluate the clinical success of a hydrophilic fissure sealant on the lower permanent molar teeth in dry and wet conditions. This clinical trial assessed 31 patients (mean age 8.13±1.77 years) who needed fissure sealant therapy on their first or second mandibular permanent molar. Having performed dental prophylaxis, the teeth were etched and rinsed. Then one of the two was randomly selected and sealed with smartseal & loc in isolated and dry conditions; while, the other was wetted on the etched enamel by using a saliva-contaminated micro brush, and was then sealed with the same fissure as the first tooth. Six and 12 months later, two independent observers examined the clinical success of sealant through checking the marginal integrity, marginal discoloration, and anatomical form. Data were analyzed by using SPSS software, version 16. The bivariate Chi-square and Exact Fisher tests were used to compare the clinical success of the two treatment methods. There was a high interpersonal reliability between the two examiners (K= 0.713). After 12 months, 90.3% clinical success was observed in dry conditions and 83.9% in wet conditions for smartseal & loc; however, the difference was not statistically significant (p= 0.0707). According to the results of this study, it seems that using new hydrophilic fissure sealant can reduce technical sensitivities and consequently decreases the apprehensions on saliva contamination of etched enamel during treatment procedures.

  12. Utility of remote sensing-based surface energy balance models to track water stress in rain-fed switchgrass under dry and wet conditions

    Science.gov (United States)

    Bhattarai, Nishan; Wagle, Pradeep; Gowda, Prasanna H.; Kakani, Vijaya G.

    2017-11-01

    The ability of remote sensing-based surface energy balance (SEB) models to track water stress in rain-fed switchgrass (Panicum virgatum L.) has not been explored yet. In this paper, the theoretical framework of crop water stress index (CWSI; 0 = extremely wet or no water stress condition and 1 = extremely dry or no transpiration) was utilized to estimate CWSI in rain-fed switchgrass using Landsat-derived evapotranspiration (ET) from five remote sensing based single-source SEB models, namely Surface Energy Balance Algorithm for Land (SEBAL), Mapping ET with Internalized Calibration (METRIC), Surface Energy Balance System (SEBS), Simplified Surface Energy Balance Index (S-SEBI), and Operational Simplified Surface Energy Balance (SSEBop). CWSI estimates from the five SEB models and a simple regression model that used normalized difference vegetation index (NDVI), near-surface temperature difference, and measured soil moisture (SM) as covariates were compared with those derived from eddy covariance measured ET (CWSIEC) for the 32 Landsat image acquisition dates during the 2011 (dry) and 2013 (wet) growing seasons. Results indicate that most SEB models can predict CWSI reasonably well. For example, the root mean square error (RMSE) ranged from 0.14 (SEBAL) to 0.29 (SSEBop) and the coefficient of determination (R2) ranged from 0.25 (SSEBop) to 0.72 (SEBAL), justifying the added complexity in CWSI modeling as compared to results from the simple regression model (R2 = 0.55, RMSE = 0.16). All SEB models underestimated CWSI in the dry year but the estimates from SEBAL and S-SEBI were within 7% of the mean CWSIEC and explained over 60% of variations in CWSIEC. In the wet year, S-SEBI mostly overestimated CWSI (around 28%), while estimates from METRIC, SEBAL, SEBS, and SSEBop were within 8% of the mean CWSIEC. Overall, SEBAL was the most robust model under all conditions followed by METRIC, whose performance was slightly worse and better than SEBAL in dry and wet years

  13. Microfluidic Investigation of Oil Mobilization in Shale Fracture Networks at Reservoir Conditions

    Science.gov (United States)

    Porter, M. L.; Jimenez-Martinez, J.; Carey, J. W.; Viswanathan, H. S.

    2015-12-01

    Investigations of pore-scale fluid flow and transport phenomena using engineered micromodels has steadily increased in recent years. In these investigations fluid flow is restricted to two-dimensions allowing for real time visualization and quantification of complex flow and reactive transport behavior, which is difficult to obtain in other experimental systems. One drawback to these studies is the use of engineered materials that do not faithfully represent the rock properties (e.g., porosity, wettability, roughness, etc.) encountered in subsurface formations. In this work, we describe a unique high pressure (up to 1500 psi) and temperature (up to 80 °C) microfluidics experimental system in which we investigate fluid flow and transport in geo-material (e.g., shale, Portland cement, etc.) micromodels. The use of geo-material micromodels allows us to better represent fluid-rock interactions including wettability, chemical reactivity, and nano-scale porosity at conditions representative of natural subsurface environments. Here, we present experimental results in fracture systems with applications to hydrocarbon mobility in hydraulically fractured shale. Complex fracture network patterns are derived from 3D x-ray tomography images of actual fractures created in shale rock cores. We use both shale and glass micromodels, allowing for a detailed comparison between flow phenomena in the different materials. We discuss results from two-phase huff-and-puff experiments involving N2 and n-Decane, as well as three-phase displacement experiments involving supercritical CO2, brine, and n-Decane.

  14. Measurement and modeling of CO2 diffusion coefficient in Saline Aquifer at reservoir conditions

    Science.gov (United States)

    Azin, Reza; Mahmoudy, Mohamad; Raad, Seyed; Osfouri, Shahriar

    2013-12-01

    Storage of CO2 in deep saline aquifers is a promising techniques to mitigate global warming and reduce greenhouse gases (GHG). Correct measurement of diffusivity is essential for predicting rate of transfer and cumulative amount of trapped gas. Little information is available on diffusion of GHG in saline aquifers. In this study, diffusivity of CO2 into a saline aquifer taken from oil field was measured and modeled. Equilibrium concentration of CO2 at gas-liquid interface was determined using Henry's law. Experimental measurements were reported at temperature and pressure ranges of 32-50°C and 5900-6900 kPa, respectively. Results show that diffusivity of CO2 varies between 3.52-5.98×10-9 m2/s for 5900 kPa and 5.33-6.16×10-9 m2/s for 6900 kPa initial pressure. Also, it was found that both pressure and temperature have a positive impact on the measures of diffusion coefficient. Liquid swelling due to gas dissolution and variations in gas compressibility factor as a result of pressure decay was found negligible. Measured diffusivities were used model the physical model and develop concentration profile of dissolved gas in the liquid phase. Results of this study provide unique measures of CO2 diffusion coefficient in saline aquifer at high pressure and temperature conditions, which can be applied in full-field studies of carbon capture and sequestration projects.

  15. Assessing crop-specific impacts of extremely wet (2007) and dry (2003) conditions in France on regional maize and wheat yields

    Science.gov (United States)

    van der Velde, Marijn

    2010-05-01

    Extreme weather conditions can strongly affect agricultural production. In France, crop yields were greatly influenced by drought and heat stress in 2003 and by extremely wet conditions in 2007. Both maize and wheat yield where historically low in 2003, in contrast to 2007 when wheat yields were lower and maize yields were higher than long-term averages. Even though maize yield loss was lower in regions with higher maize irrigation percentages; yield loss was still very considerable. Remotely sensed (AMSR-E) JJA soil moisture related significantly to reported regional crop yield for 2002-2007. The spatial correlation between JJA soil moisture and wheat yield anomalies was positive in dry 2003 and negative in wet 2007. Biweekly soil moisture correlated positively from the first half of June until the second half of July in 2003. In 2007, the relation was negative the first half of June until the second half of August. An analysis with a spatial version (10 by 10 km) of the EPIC crop growth model was used to infer causal relations between rainfall, soil moisture and rainfed wheat and rainfed and irrigated maize yield. The negative impacts of the 2003 heat wave and drought on wheat yield were captured by the model, while negative damages to yield due to excessive wetness in 2007 were not. Modelling suggests that regional drought mitigation increased with increasing maize irrigation percentages from 0 to 40%. At higher irrigation percentages the compensating effect of irrigation was small. The above average maize yields in 2007 were reproduced by the model, but the below average wheat yields were not. The model overestimation of wheat yield in 2007 may be due to a misrepresentation of the impact of wet conditions on plant physiological processes, or due to the incapacity of the model to represent determining factors such as lodging and unfavourable harvesting conditions. Strenghts and limitations of this regional assessment will be discussed. Extreme events affect

  16. EQUILGAS: Program to estimate temperatures and in situ two-phase conditions in geothermal reservoirs using three combined FT-HSH gas equilibria models

    Science.gov (United States)

    Barragán, Rosa María; Núñez, José; Arellano, Víctor Manuel; Nieva, David

    2016-03-01

    Exploration and exploitation of geothermal resources require the estimation of important physical characteristics of reservoirs including temperatures, pressures and in situ two-phase conditions, in order to evaluate possible uses and/or investigate changes due to exploitation. As at relatively high temperatures (>150 °C) reservoir fluids usually attain chemical equilibrium in contact with hot rocks, different models based on the chemistry of fluids have been developed that allow deep conditions to be estimated. Currently either in water-dominated or steam-dominated reservoirs the chemistry of steam has been useful for working out reservoir conditions. In this context, three methods based on the Fischer-Tropsch (FT) and combined H2S-H2 (HSH) mineral-gas reactions have been developed for estimating temperatures and the quality of the in situ two-phase mixture prevailing in the reservoir. For these methods the mineral buffers considered to be controlling H2S-H2 composition of fluids are as follows. The pyrite-magnetite buffer (FT-HSH1); the pyrite-hematite buffer (FT-HSH2) and the pyrite-pyrrhotite buffer (FT-HSH3). Currently from such models the estimations of both, temperature and steam fraction in the two-phase fluid are obtained graphically by using a blank diagram with a background theoretical solution as reference. Thus large errors are involved since the isotherms are highly nonlinear functions while reservoir steam fractions are taken from a logarithmic scale. In order to facilitate the use of the three FT-HSH methods and minimize visual interpolation errors, the EQUILGAS program that numerically solves the equations of the FT-HSH methods was developed. In this work the FT-HSH methods and the EQUILGAS program are described. Illustrative examples for Mexican fields are also given in order to help the users in deciding which method could be more suitable for every specific data set.

  17. Limnological Conditions and Occurrence of Taste-and-Odor Compounds in Lake William C. Bowen and Municipal Reservoir #1, Spartanburg County, South Carolina, 2006-2009

    Science.gov (United States)

    Journey, Celeste A.; Arrington, Jane M.; Beaulieu, Karen M.; Graham, Jennifer L.; Bradley, Paul M.

    2011-01-01

    Limnological conditions and the occurrence of taste-and-odor compounds were studied in two reservoirs in Spartanburg County, South Carolina, from May 2006 to June 2009. Lake William C. Bowen and Municipal Reservoir #1 are relatively shallow, meso-eutrophic, warm monomictic, cascading impoundments on the South Pacolet River. Overall, water-quality conditions and phytoplankton community assemblages were similar between the two reservoirs but differed seasonally. Median dissolved geosmin concentrations in the reservoirs ranged from 0.004 to 0.006 microgram per liter. Annual maximum dissolved geosmin concentrations tended to occur between March and May. In this study, peak dissolved geosmin production occurred in April and May 2008, ranging from 0.050 to 0.100 microgram per liter at the deeper reservoir sites. Peak dissolved geosmin production was not concurrent with maximum cyanobacterial biovolumes, which tended to occur in the summer (July to August), but was concurrent with a peak in the fraction of genera with known geosmin-producing strains in the cyanobacteria group. Nonetheless, annual maximum cyanobacterial biovolumes rarely resulted in cyanobacteria dominance of the phytoplankton community. In both reservoirs, elevated dissolved geosmin concentrations were correlated to environmental factors indicative of unstratified conditions and reduced algal productivity, but not to nutrient concentrations or ratios. With respect to potential geosmin sources, elevated geosmin concentrations were correlated to greater fractions of genera with known geosmin-producing strains in the cyanobacteria group and to biovolumes of a specific geosmin-producing cyanobacteria genus (Oscillatoria), but not to actinomycetes concentrations. Conversely, environmental factors that correlated with elevated cyanobacterial biovolumes were indicative of stable water columns (stratified conditions), warm water temperatures, reduced nitrogen concentrations, longer residence times, and high

  18. A.C. and D.C. conductivity of NiZn ferrite nanoparticles in wet and dry conditions

    Science.gov (United States)

    Saafan, S. A.; Meaz, T. M.; El-Ghazzawy, E. H.; El Nimr, M. K.; Ayad, M. M.; Bakr, M.

    2010-08-01

    Promising future applications of ferrite nanoparticles in medicine, drug delivery, sensors and ferrofluids are expected to be in wet or humid environments. Therefore nanostructured powders of ferrites having the chemical compositions. Ni xZn (1- x) Fe 2O 4 with ( x=0.0, 0.25, 0.5, 0.75, and 1) were pressed immediately after preparation - by the co-precipitation method - without any drying to simulate a humid environment. The nanoparticles were characterized by X-ray diffraction analysis (XRD) to be sure of the formation of the ferrite in nanoscale. The infrared (IR) spectroscopy of the samples ensures the existence of water as well as the characteristic absorption bands of ferrites. The ac and dc conductivity of the samples had been investigated immediately after preparation (the as-prepared samples). Then, the samples were dried at 200 °C for about 12 h and reinvestigated. The behavior of conductivity differs significantly in the two cases showing a noticeable effect due to humidity. Also, the magnetic induction of the as-prepared samples was investigated by using the vibrating sample magnetometer (VSM). The samples show superparamagnetic behavior.

  19. Large reservoirs: Chapter 17

    Science.gov (United States)

    Miranda, Leandro E.; Bettoli, Phillip William

    2010-01-01

    expressed effects, such as turbidity and water quality, zooplankton density and size composition, or fish growth rates and assemblage composition, are the upshot of large-scale factors operating outside reservoirs and not under the direct control of reservoir managers. Realistically, abiotic and biotic conditions in reservoirs are shaped by factors working inside and outside reservoirs, with the relative importance of external factors differing among reservoirs. With this perspective, large reservoirs are viewed from a habitat standpoint within the framework of a conceptual model in which individual reservoir characteristics are influenced by both local- and landscape-scale factors (Figure 17.1). In the sections that follow, how each element of this hierarchical model influences habitat and fish assemblages in reservoirs is considered. Important in-reservoir habitat issues and reservoirs as part of larger systems, where reservoir management requires looking for real solutions outside individual reservoirs are described.

  20. Prediction in Ungauged Basins (PUB) for estimating water availability during water scarcity conditions: rainfall-runoff modelling of the ungauged diversion inflows to the Ridracoli water supply reservoir

    Science.gov (United States)

    Toth, Elena

    2013-04-01

    The Ridracoli reservoir is the main drinking water supply reservoir serving the whole Romagna region, in Northern Italy. Such water supply system has a crucial role in an area where the different characteristics of the communities to be served, their size, the mass tourism and the presence of food industries highlight strong differences in drinking water needs. Its operation allows high quality drinking water supply to a million resident customers, plus a few millions of tourists during the summer of people and it reduces the need for water pumping from underground sources, and this is particularly important since the coastal area is subject also to subsidence and saline ingression into aquifers. The system experienced water shortage conditions thrice in the last decade, in 2002, in 2007 and in autumn-winter 2011-2012, when the reservoir water storage fell below the attention and the pre-emergency thresholds, thus prompting the implementation of a set of mitigation measures, including limitations to the population's water consumption. The reservoir receives water not only from the headwater catchment, closed at the dam, but also from four diversion watersheds, linked to the reservoir through an underground water channel. Such withdrawals are currently undersized, abstracting only a part of the streamflow exceeding the established minimum flows, due to the design of the water intake structures; it is therefore crucial understanding how the reservoir water availability might be increased through a fuller exploitation of the existing diversion catchment area. Since one of the four diversion catchment is currently ungauged (at least at the fine temporal scale needed for keeping into account the minimum flow requirements downstream of the intakes), the study first presents the set up and parameterisation of a continuous rainfall-runoff model at hourly time-step for the three gauged diversion watersheds and for the headwater catchment: a regional parameterisation

  1. An intuitionistic fuzzy multi-objective non-linear programming model for sustainable irrigation water allocation under the combination of dry and wet conditions

    Science.gov (United States)

    Li, Mo; Fu, Qiang; Singh, Vijay P.; Ma, Mingwei; Liu, Xiao

    2017-12-01

    Water scarcity causes conflicts among natural resources, society and economy and reinforces the need for optimal allocation of irrigation water resources in a sustainable way. Uncertainties caused by natural conditions and human activities make optimal allocation more complex. An intuitionistic fuzzy multi-objective non-linear programming (IFMONLP) model for irrigation water allocation under the combination of dry and wet conditions is developed to help decision makers mitigate water scarcity. The model is capable of quantitatively solving multiple problems including crop yield increase, blue water saving, and water supply cost reduction to obtain a balanced water allocation scheme using a multi-objective non-linear programming technique. Moreover, it can deal with uncertainty as well as hesitation based on the introduction of intuitionistic fuzzy numbers. Consideration of the combination of dry and wet conditions for water availability and precipitation makes it possible to gain insights into the various irrigation water allocations, and joint probabilities based on copula functions provide decision makers an average standard for irrigation. A case study on optimally allocating both surface water and groundwater to different growth periods of rice in different subareas in Heping irrigation area, Qing'an County, northeast China shows the potential and applicability of the developed model. Results show that the crop yield increase target especially in tillering and elongation stages is a prevailing concern when more water is available, and trading schemes can mitigate water supply cost and save water with an increased grain output. Results also reveal that the water allocation schemes are sensitive to the variation of water availability and precipitation with uncertain characteristics. The IFMONLP model is applicable for most irrigation areas with limited water supplies to determine irrigation water strategies under a fuzzy environment.

  2. Wet and cold climate conditions recorded by coral geochemical proxies during the beginning of the first millennium CE in the northern South China Sea

    Science.gov (United States)

    Xiao, Hangfang; Deng, Wenfeng; Chen, Xuefei; Wei, Gangjian; Zeng, Ti; Zhao, Jian-xin

    2017-03-01

    The past two millennia include some distinct climate intervals, such as the Medieval Warm Period (MWP) and the Little Ice Age (LIA), which were caused by natural forcing factors, as well as the Current Warm Period (CWP) that has been linked to anthropogenic factors. Therefore, this period has been of great interest to climate change researchers. However, most studies are based on terrestrial proxy records, historical documentary data, and simulation results, and the ocean and the tropical record are very limited. The Eastern Han, Three Kingdoms, and Western Jin periods (25-316 CE) cover the beginning first millennium CE in China, and were characterized by a cold climate and frequent wars and regime changes. This study used paired Sr/Ca and δ18O series recovered from a fossil coral to reconstruct the sea surface water conditions during the late Eastern Han to Western Jin periods (167-309 CE) at Wenchang, eastern Hainan Island in the northern South China Sea (SCS), to investigate climate change at this time. The long-term sea surface temperature (SST) during the study interval was 25.1 °C, which is about 1.5 °C lower than that of the CWP (26.6 °C). Compared with the average value of 0.40‰ during the CWP, the long-term average seawater δ18O (-0.06‰) was more negative. These results indicate that the climate conditions during the study period were cold and wet and comparable with those of the LIA. This colder climate may have been associated with the weaker summer solar irradiance. The wet conditions were caused by the reduced northward shift of the intertropical convergence zone/monsoon rainbelt associated with the retreat of the East Asian summer monsoon. Interannual and interdecadal climate variability may also have contributed to the variations in SST and seawater δ18O recorded over the study period.

  3. Assessment of managed aquifer recharge at Sand Hollow Reservoir, Washington County, Utah, updated to conditions through 2007

    Science.gov (United States)

    Heilweil, Victor M.; Ortiz, Gema; Susong, David D.

    2009-01-01

    Sand Hollow Reservoir in Washington County, Utah, was completed in March 2002 and is operated primarily as an aquifer storage and recovery project by the Washington County Water Conservancy District (WCWCD). Since its inception in 2002 through 2007, surface-water diversions of about 126,000 acre-feet to Sand Hollow Reservoir have resulted in a generally rising reservoir stage and surface area. Large volumes of runoff during spring 2005-06 allowed the WCWCD to fill the reservoir to a total storage capacity of more than 50,000 acre-feet, with a corresponding surface area of about 1,300 acres and reservoir stage of about 3,060 feet during 2006. During 2007, reservoir stage generally decreased to about 3,040 feet with a surface-water storage volume of about 30,000 acre-feet. Water temperature in the reservoir shows large seasonal variation and has ranged from about 3 to 30 deg C from 2003 through 2007. Except for anomalously high recharge rates during the first year when the vadose zone beneath the reservoir was becoming saturated, estimated ground-water recharge rates have ranged from 0.01 to 0.09 feet per day. Estimated recharge volumes have ranged from about 200 to 3,500 acre-feet per month from March 2002 through December 2007. Total ground-water recharge during the same period is estimated to have been about 69,000 acre-feet. Estimated evaporation rates have varied from 0.04 to 0.97 feet per month, resulting in evaporation losses of 20 to 1,200 acre-feet per month. Total evaporation from March 2002 through December 2007 is estimated to have been about 25,000 acre-feet. Results of water-quality sampling at monitoring wells indicate that by 2007, managed aquifer recharge had arrived at sites 37 and 36, located 60 and 160 feet from the reservoir, respectively. However, different peak arrival dates for specific conductance, chloride, chloride/bromide ratios, dissolved oxygen, and total dissolved-gas pressures at each monitoring well indicate the complicated nature of

  4. Heat treatment of wet wood fiber: A study of the effect of reaction conditions on the formation of furfurals

    Science.gov (United States)

    Mandla A. Tshabalala; James D. McSweeny; Roger M. Rowell

    2012-01-01

    Furan monomers are produced when wood is heated at high temperatures. To understand the process conditions for production of furfural (FF) and hydroxymethylfurfural (HMF) from wood, samples of milled aspen wood were subjected to autohydrolyzis by microwave heating in a sealed Teflon reactor. The experiments were designed to simulate temperature and pressure variables...

  5. Evapotranspiration and land surface process responses to afforestation in western Taiwan: A comparison between dry and wet weather conditions

    Science.gov (United States)

    Yongqiang Liu; L.B. Zhang; L. Hao; Ge Sun; S.-C. Liu

    2016-01-01

    An afforestation project was initiated in the western plain of Taiwan to convert abandoned farming lands into forests to improve the ecological and environmental conditions. This study was conducted to understand the potential impacts of this land cover change on evapotranspiration (ET) and other land surface processes and the...

  6. Wetting front instability in an initially wet unsaturated fracture

    International Nuclear Information System (INIS)

    Nicholl, M.J.; Glass, R.J.; Nguyen, H.A.

    1993-01-01

    Experimental results exploring gravity-driven wetting from instability in a pre-wetted, rough-walled analog fractures such as those at Yucca Mountain are presented. Initial conditions considered include a uniform moisture field wetted to field capacity of the analog fracture and the structured moisture field created by unstable infiltration into an initially dry fracture. As in previous studies performed under dry initial conditions, instability was found to result both at the cessation of stable infiltration and at flux lower than the fracture capacity under gravitational driving force. Individual fingers were faster, narrower, longer, and more numerous than observed under dry initial conditions. Wetting fronts were found to follow existing wetted structure, providing a mechanism for rapid recharge and transport

  7. Variation in the Asian monsoon intensity and dry-wet conditions since the Little Ice Age in central China revealed by an aragonite stalagmite

    Science.gov (United States)

    Yin, J.-J.; Yuan, D.-X.; Li, H.-C.; Cheng, H.; Li, T.-Y.; Edwards, R. L.; Lin, Y.-S.; Qin, J.-M.; Tang, W.; Zhao, Z.-Y.; Mii, H.-S.

    2014-10-01

    This paper focuses on the climate variability in central China since AD 1300, involving: (1) a well-dated, 1.5-year resolution stalagmite δ18O record from Lianhua Cave, central China (2) links of the δ18O record with regional dry-wet conditions, monsoon intensity, and temperature over eastern China (3) correlations among drought events in the Lianhua record, solar irradiation, and ENSO (El Niño-Southern Oscillation) variation. We present a highly precise, 230Th / U-dated, 1.5-year resolution δ18O record of an aragonite stalagmite (LHD1) collected from Lianhua Cave in the Wuling Mountain area of central China. The comparison of the δ18O record with the local instrumental record and historical documents indicates that (1) the stalagmite δ18O record reveals variations in the summer monsoon intensity and dry-wet conditions in the Wuling Mountain area. (2) A stronger East Asian summer monsoon (EASM) enhances the tropical monsoon trough controlled by ITCZ (Intertropical Convergence Zone), which produces higher spring quarter rainfall and isotopically light monsoonal moisture in the central China. (3) The summer quarter/spring quarter rainfall ratio in central China can be a potential indicator of the EASM strength: a lower ratio corresponds to stronger EASM and higher spring rainfall. The ratio changed from 1 after 1950, reflecting that the summer quarter rainfall of the study area became dominant under stronger influence of the Northwestern Pacific High. Eastern China temperatures varied with the solar activity, showing higher temperatures under stronger solar irradiation, which produced stronger summer monsoons. During Maunder, Dalton and 1900 sunspot minima, more severe drought events occurred, indicating a weakening of the summer monsoon when solar activity decreased on decadal timescales. On an interannual timescale, dry conditions in the study area prevailed under El Niño conditions, which is also supported by the spectrum analysis. Hence, our record

  8. Variation in the Asian monsoon intensity and dry-wet condition since the Little Ice Age in central China revealed by an aragonite stalagmite

    Science.gov (United States)

    Yin, J.-J.; Yuan, D.-X.; Li, H.-C.; Cheng, H.; Li, T.-Y.; Edwards, R. L.; Lin, Y.-S.; Qin, J.-M.; Tang, W.; Zhao, Z.-Y.; Mii, H.-S.

    2014-04-01

    Highlight: this paper focuses on the climate variability in central China since 1300 AD, involving: 1. A well-dated, 1.5 year resolution stalagmite δ18O record from Lianhua Cave, central China; 2. Links of the δ18O record with regional dry-wet condition, monsoon intensity, and temperature over eastern China; 3. Correlations among drought events in the Lianhua record, solar irradiation, and ENSO index. We present a highly precisely 230Th/U dated, 1.5 year resolution δ18O record of an aragonite stalagmite (LHD1) collected from Lianhua Cave in Wuling mountain area of central China. The comparison of the δ18O record with the local instrumental record and historical documents exhibits at least 15 drought events in the Wuling mountain and adjacent areas during the Little Ice Age, in which some of them were corresponding to megadrought events in the broad Asian monsoonal region of China. Thus, the stalagmite δ18O record reveals variations in the summer monsoon precipitation and dry-wet condition in Wuling mountain area. The eastern China temperature varied with the solar activity, showing higher temperature under stronger solar irradiation which produces stronger summer monsoon. During Maunder, Dalton and 1900 sunspot minima, more severe drought events occurred, indicating weakening of the summer monsoon when solar activity decreased on decadal time scales. On interannual time scale, dry conditions in the studying area were prevailing under El Niño condition, which is also supported by the spectrum analysis. Hence, our record illustrates the linkage of Asian summer monsoon precipitation to solar irradiation and ENSO: wetter condition under stronger summer monsoon during warm periods and vice versa; During cold periods, the Walker circulation will shift toward central Pacific under El Niño condition, resulting further weakening of Asian summer monsoon. However, the δ18O of LHD1 record is positively correlated with temperature after ~1940 AD which is opposite to the

  9. WETTABILITY AND IMBIBITION: MICROSCOPIC DISTRIBUTION OF WETTING AND ITS CONSEQUENCES AT THE CORE AND FIELD SCALES

    Energy Technology Data Exchange (ETDEWEB)

    Jill S. Buckley; Norman R. Morrow; Chris Palmer; Purnendu K. Dasgupta

    2003-02-01

    The questions of reservoir wettability have been approached in this project from three directions. First, we have studied the properties of crude oils that contribute to wetting alteration in a reservoir. A database of more than 150 different crude oil samples has been established to facilitate examination of the relationships between crude oil chemical and physical properties and their influence on reservoir wetting. In the course of this work an improved SARA analysis technique was developed and major advances were made in understanding asphaltene stability including development of a thermodynamic Asphaltene Solubility Model (ASM) and empirical methods for predicting the onset of instability. The CO-Wet database is a resource that will be used to guide wettability research in the future. The second approach is to study crude oil/brine/rock interactions on smooth surfaces. Contact angle measurements were made under controlled conditions on mica surfaces that had been exposed to many of the oils in the CO-Wet database. With this wealth of data, statistical tests can now be used to examine the relationships between crude oil properties and the tendencies of those oils to alter wetting. Traditionally, contact angles have been used as the primary wetting assessment tool on smooth surfaces. A new technique has been developed using an atomic forces microscope that adds a new dimension to the ability to characterize oil-treated surfaces. Ultimately we aim to understand wetting in porous media, the focus of the third approach taken in this project. Using oils from the CO-Wet database, experimental advances have been made in scaling the rate of imbibition, a sensitive measure of core wetting. Application of the scaling group to mixed-wet systems has been demonstrated for a range of core conditions. Investigations of imbibition in gas/liquid systems provided the motivation for theoretical advances as well. As a result of this project we have many new tools for studying

  10. No measurable adverse effects of Lassa, Morogoro and Gairo arenaviruses on their rodent reservoir host in natural conditions

    Czech Academy of Sciences Publication Activity Database

    Mariën, J.; Borremans, B.; Gryseels, S.; Soropogui, B.; De Bruyn, L.; Ngiala Bongo, G.; Becker-Ziaja, B.; Goüy de Bellocq, Joëlle; Günther, S.; Magassouba, N.; Leirs, H.; Fichet-Calvet, E.

    2017-01-01

    Roč. 10, č. 1 (2017), č. článku 210. ISSN 1756-3305 Institutional support: RVO:68081766 Keywords : Arenavirus * Lassa virus * Morogoro virus * Gairo virus * Mastomys natalensis * Rodent-borne disease * Host-pathogen interaction * Reservoir host Subject RIV: EG - Zoology OBOR OECD: Parasitology Impact factor: 3.080, year: 2016

  11. Tear film dynamics with evaporation, wetting, and time-dependent flux boundary condition on an eye-shaped domain

    Science.gov (United States)

    Li, Longfei; Braun, R. J.; Maki, K. L.; Henshaw, W. D.; King-Smith, P. E.

    2014-01-01

    We study tear film dynamics with evaporation on a wettable eye-shaped ocular surface using a lubrication model. The mathematical model has a time-dependent flux boundary condition that models the cycles of tear fluid supply and drainage; it mimics blinks on a stationary eye-shaped domain. We generate computational grids and solve the nonlinear governing equations using the OVERTURE computational framework. In vivo experimental results using fluorescent imaging are used to visualize the influx and redistribution of tears for an open eye. Results from the numerical simulations are compared with the experiment. The model captures the flow around the meniscus and other dynamic features of human tear film observed in vivo. PMID:24926191

  12. Multivariate Optimization of Conditions for Digestion of Wet Feeds for Dogs and Cats Using a Closed Digester Block and Multielement Determination by ICP-OES.

    Science.gov (United States)

    Ávila, Dayara Virgínia Lino; Souza, Sidnei Oliveira; Costa, Silvânio Silvério Lopes; Garcia, Carlos Alexandre Borges; Alves, José do Patrocínio Hora; Araujo, Rennan Geovanny Oliveira; Passos, Elisangela Andrade

    2017-09-01

    A full 24 factorial design was applied to find the best combination of diluted reagents (HNO3 and H2O2), time, and temperature for the digestion of samples of wet feed for dogs and cats using a closed digestion block. The residual carbon concentration (RCC) was used as the response in the factorial design. All variables and their interactions significantly influenced the digestion of the feed samples, as indicated by the RCC. The conditions established for the digestion of 0.05 g (dry mass) wet feed samples were the addition of 3.0 mol/L HNO3 and 5.0% m/m H2O2 in a final volume of 10 mL, followed by heating in a closed digestion block at a temperature of 170°C for 120 min. Analyses were performed by inductively coupled plasma (ICP) optical emission spectrometry (OES). LOQs ranged from 0.2 μg/g (Mg and Sr) to 51 μg/g (P). Accuracy of the analytical method was confirmed through the analysis of the Standard Reference Materials Tomato Leaves (NIST 1573), Apple Leaves (NIST 1515), and Peach Leaves (NIST 1547). The agreement values achieved ranged from 80.2 ± 0.3% for Ba to 113.8 ± 7.1% for Zn (n = 3). Addition and recovery tests were carried out by adding the analytes to a feed sample at two concentration levels, and the recoveries were between 84 ± 6 and 114 ± 10% for macroelements (Ca, K, Mg, and P; n = 3) and between 88 ± 3 and 113 ± 7% for microelements and trace elements (B, Cu, Fe, Sr, and Zn; n = 3). The precision values achieved for the different elements, expressed as RSDs, were better than 7.3% (Zn; n = 3) except for Cu determination, that was 14.6% (n=3). The optimized analytical method was applied to 10 commercial samples of wet feed for cats and dogs, with the concentrations of Al, B, Ba, Ca, Cu, Fe, K, Mg, Mn, P, Sr, and Zn determined by ICP-OES.

  13. In situ investigation of wet chemical processes for chalcopyrite solar cells by L-edge XAS under ambient conditions

    Energy Technology Data Exchange (ETDEWEB)

    Greil, Stefanie M. [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Lauermann, Iver, E-mail: Iver.lauermann@helmholtz-berlin.d [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Ennaoui, Ahmed; Kropp, Timo; Lange, Kathrin M.; Weber, Matthieu [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Aziz, Emad F., E-mail: Emad.Aziz@helmholtz-berlin.d [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin (Germany)

    2010-02-15

    Two instrumental setups for in situ soft X-ray absorption spectroscopy in liquid systems are demonstrated in this work. One for investigating chemical reactions in solutions and a new one for the solid component of a liquid / (as in both / absorber) solid interface. We used these setups for investigating two production processes for chalcopyrite solar cells under ambient conditions, probing the L-edge of Zn and Cu. The first one is a flow cell with a silicon nitride membrane to study the chemical bath deposition process for Cd-free buffer layers. Examining the electronic structure of involved Zn complexes allows to determine the exact reaction mechanism taking place during this process. The second setup is a rotating disk for investigating the bath/absorber interface upon the etching process of superficial binary copper compounds of the absorber as a function of time. The time resolution of the chemical reaction demonstrated in this study ranges from the second to minute time scale.

  14. In situ investigation of wet chemical processes for chalcopyrite solar cells by L-edge XAS under ambient conditions

    International Nuclear Information System (INIS)

    Greil, Stefanie M.; Lauermann, Iver; Ennaoui, Ahmed; Kropp, Timo; Lange, Kathrin M.; Weber, Matthieu; Aziz, Emad F.

    2010-01-01

    Two instrumental setups for in situ soft X-ray absorption spectroscopy in liquid systems are demonstrated in this work. One for investigating chemical reactions in solutions and a new one for the solid component of a liquid / (as in both / absorber) solid interface. We used these setups for investigating two production processes for chalcopyrite solar cells under ambient conditions, probing the L-edge of Zn and Cu. The first one is a flow cell with a silicon nitride membrane to study the chemical bath deposition process for Cd-free buffer layers. Examining the electronic structure of involved Zn complexes allows to determine the exact reaction mechanism taking place during this process. The second setup is a rotating disk for investigating the bath/absorber interface upon the etching process of superficial binary copper compounds of the absorber as a function of time. The time resolution of the chemical reaction demonstrated in this study ranges from the second to minute time scale.

  15. In situ investigation of wet chemical processes for chalcopyrite solar cells by L-edge XAS under ambient conditions

    Science.gov (United States)

    Greil, Stefanie M.; Lauermann, Iver; Ennaoui, Ahmed; Kropp, Timo; Lange, Kathrin M.; Weber, Matthieu; Aziz, Emad F.

    2010-02-01

    Two instrumental setups for in situ soft X-ray absorption spectroscopy in liquid systems are demonstrated in this work. One for investigating chemical reactions in solutions and a new one for the solid component of a liquid / (as in both / absorber) solid interface. We used these setups for investigating two production processes for chalcopyrite solar cells under ambient conditions, probing the L-edge of Zn and Cu. The first one is a flow cell with a silicon nitride membrane to study the chemical bath deposition process for Cd-free buffer layers. Examining the electronic structure of involved Zn complexes allows to determine the exact reaction mechanism taking place during this process. The second setup is a rotating disk for investigating the bath/absorber interface upon the etching process of superficial binary copper compounds of the absorber as a function of time. The time resolution of the chemical reaction demonstrated in this study ranges from the second to minute time scale.

  16. A new method suitable for calculating accurately wetting temperature over a wide range of conditions: Based on the adaptation of continuation algorithm to classical DFT

    Science.gov (United States)

    Zhou, Shiqi

    2017-11-01

    A new scheme is put forward to determine the wetting temperature (Tw) by utilizing the adaptation of arc-length continuation algorithm to classical density functional theory (DFT) used originally by Frink and Salinger, and its advantages are summarized into four points: (i) the new scheme is applicable whether the wetting occurs near a planar or a non-planar surface, whereas a zero contact angle method is considered only applicable to a perfectly flat solid surface, as demonstrated previously and in this work, and essentially not fit for non-planar surface. (ii) The new scheme is devoid of an uncertainty, which plagues a pre-wetting extrapolation method and originates from an unattainability of the infinitely thick film in the theoretical calculation. (iii) The new scheme can be similarly and easily applied to extreme instances characterized by lower temperatures and/or higher surface attraction force field, which, however, can not be dealt with by the pre-wetting extrapolation method because of the pre-wetting transition being mixed with many layering transitions and the difficulty in differentiating varieties of the surface phase transitions. (iv) The new scheme still works in instance wherein the wetting transition occurs close to the bulk critical temperature; however, this case completely can not be managed by the pre-wetting extrapolation method because near the bulk critical temperature the pre-wetting region is extremely narrow, and no enough pre-wetting data are available for use of the extrapolation procedure.

  17. Changes in sources and storage in a karst aquifer during a transition from drought to wet conditions

    Science.gov (United States)

    Wong, C.I.; Mahler, B.J.; Musgrove, M.; Banner, J.L.

    2012-01-01

    Understanding the sources and processes that control groundwater compositions and the timing and magnitude of groundwater vulnerability to potential surface-water contamination under varying meteorologic conditions is critical to informing groundwater protection policies and practices. This is especially true in karst terrains, where infiltrating surface water can rapidly affect groundwater quality. We analyzed the evolution of groundwater compositions (major ions and Sr isotopes) during the transition from extreme drought to wetconditions, and used inverse geochemical modeling (PHREEQC) to constrain controls on groundwater compositions during this evolution. Spring water and groundwater from two wells dominantly receiving diffuse and conduit flow (termed diffuse site and conduit site, respectively) in the Barton Springs segment of the Edwards aquifer (central Texas, USA) and surface water from losing streams that recharge the aquifer were sampled every 3–4 weeks during November 2008–March 2010. During this period, water compositions at the spring and conduit sites changed rapidly but there was no change at the diffuse site, illustrating the dual nature (i.e., diffuse vs. conduit) of flow in this karst system. Geochemical modeling demonstrated that, within a month of the onset of wetconditions, the majority of spring water and groundwater at the conduit site was composed of surface water, providing quantitative information on the timing and magnitude of the vulnerability of groundwater to potential surface-water contamination. The temporal pattern of increasing spring discharge and changing pattern of covariation between spring discharge and surface-water (steam) recharge indicates that that there were two modes of aquifer response—one with a small amount of storage and a second that accommodates more storage.

  18. Two-phase flow visualization under reservoir conditions for highly heterogeneous conglomerate rock: A core-scale study for geologic carbon storage.

    Science.gov (United States)

    Kim, Kue-Young; Oh, Junho; Han, Weon Shik; Park, Kwon Gyu; Shinn, Young Jae; Park, Eungyu

    2018-03-20

    Geologic storage of carbon dioxide (CO 2 ) is considered a viable strategy for significantly reducing anthropogenic CO 2 emissions into the atmosphere; however, understanding the flow mechanisms in various geological formations is essential for safe storage using this technique. This study presents, for the first time, a two-phase (CO 2 and brine) flow visualization under reservoir conditions (10 MPa, 50 °C) for a highly heterogeneous conglomerate core obtained from a real CO 2 storage site. Rock heterogeneity and the porosity variation characteristics were evaluated using X-ray computed tomography (CT). Multiphase flow tests with an in-situ imaging technology revealed three distinct CO 2 saturation distributions (from homogeneous to non-uniform) dependent on compositional complexity. Dense discontinuity networks within clasts provided well-connected pathways for CO 2 flow, potentially helping to reduce overpressure. Two flow tests, one under capillary-dominated conditions and the other in a transition regime between the capillary and viscous limits, indicated that greater injection rates (potential causes of reservoir overpressure) could be significantly reduced without substantially altering the total stored CO 2 mass. Finally, the capillary storage capacity of the reservoir was calculated. Capacity ranged between 0.5 and 4.5%, depending on the initial CO 2 saturation.

  19. Determining Carbon and Oxygen Stable Isotope Systematics in Brines at Elevated p/T Conditions to Enhance Monitoring of CO2 Induced Processes in Carbon Storage Reservoirs

    Science.gov (United States)

    Becker, V.; Myrttinen, A.; Mayer, B.; Barth, J. A.

    2012-12-01

    Stable carbon isotope ratios (δ13C) are a powerful tool for inferring carbon sources and mixing ratios of injected and baseline CO2 in storage reservoirs. Furthermore, CO2 releasing and consuming processes can be deduced if the isotopic compositions of end-members are known. At low CO2 pressures (pCO2), oxygen isotope ratios (δ18O) of CO2 usually assume the δ18O of the water plus a temperature-dependent isotope fractionation factor. However, at very high CO2 pressures as they occur in CO2 storage reservoirs, the δ18O of the injected CO2 may in fact change the δ18O of the reservoir brine. Hence, changing δ18O of brine constitutes an additional tracer for reservoir-internal carbon dynamics and allows the determination of the amount of free phase CO2 present in the reservoir (Johnson et al. 2011). Further systematic research to quantify carbon and oxygen isotope fractionation between the involved inorganic carbon species (CO2, H2CO3, HCO3-, CO32-, carbonate minerals) and kinetic and equilibrium isotope effects during gas-water-rock interactions is necessary because p/T conditions and salinities in CO2 storage reservoirs may exceed the boundary conditions of typical environmental isotope applications, thereby limiting the accuracy of stable isotope monitoring approaches in deep saline formations (Becker et al. 2011). In doing so, it is crucial to compare isotopic patterns observed in laboratory experiments with artificial brines to similar experiments with original fluids from representative field sites to account for reactions of dissolved inorganic carbon (DIC) with minor brine components. In the CO2ISO-LABEL project, funded by the German Ministry for Education and Research, multiple series of laboratory experiments are conducted to determine the influence of pressure, temperature and brine composition on the δ13C of DIC and the δ18O of brines in water-CO2-rock reactions with special focus placed on kinetics and stable oxygen and carbon isotope fractionation

  20. iTOUGH2-EOS1SC. Multiphase Reservoir Simulator for Water under Sub- and Supercritical Conditions. User's Guide

    Energy Technology Data Exchange (ETDEWEB)

    Magnusdottir, Lilja [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Finsterle, Stefan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-03-01

    Supercritical fluids exist near magmatic heat sources in geothermal reservoirs, and the high enthalpy fluid is becoming more desirable for energy production with advancing technology. In geothermal modeling, the roots of the geothermal systems are normally avoided but in order to accurately predict the thermal behavior when wells are drilled close to magmatic intrusions, it is necessary to incorporate the heat sources into the modeling scheme. Modeling supercritical conditions poses a variety of challenges due to the large gradients in fluid properties near the critical zone. This work focused on using the iTOUGH2 simulator to model the extreme temperature and pressure conditions in magmatic geothermal systems.

  1. Intermittent Flooding of Arctic Lagoon Wet Sedge Areas: an investigation of past and future conditions at Arey Lagoon, Eastern Arctic Alaska

    Science.gov (United States)

    Gibbs, A.; Erikson, L. H.; Richmond, B. M.

    2017-12-01

    Arctic lagoons and mainland coasts support highly productive ecosystems, where soft substrate and coastal wet sedge fringing the shores act as feeding grounds and nurseries for a variety of marine fish and waterfowl. Much tundra vegetation is intolerant to saltwater flooding, but some vegetation cherished by geese for example, is maintained by flooding one to two times per month. The balance of northern ecosystems such as these may be in jeopardy as the Arctic climate is rapidly changing. In this study, sea level rise and 21st century storms are simulated with a numerical model to evaluate changes in ocean-driven flooding of low-lying tundra and coastal wet sedge that fringe the shores of Arey Lagoon, located in eastern Arctic Alaska. Numerically modeled extreme surge levels are projected to increase from a historical range of 0.5 m - 1.3 m (1976-2010) to 1.0 m - 2.0 m by end-of-century (2011-2100). The maximum storm surge of the projected time-period translates to > 6 km2 of flooded tundra, much of which consists of salt-intolerant vegetation. Monthly flood extents that might be expected to maintain halophytic vegetation were calculated by extracting the maximum monthly water levels of months that had more than 21 days ( 70%) of ice-free conditions. Median monthly water levels are shown to range from 0.46 m in 1981-1990 to 0.91 m by the final decades of the 21st century. The temporal trend is strongly linear (r2 = 0.82). An overlay of these water elevations onto a 10 m resolution elevation model shows that monthly flood extents will increase by 26% by the end of the century compared to the present decade (2011 to 2020) (from 2.86 km2 to 3.60 km2). The rate at which the flood extents are projected to increase will dictate if inland succession of salt-tolerant vegetation will survive. By combining the frequency and magnitude of extreme storm surge events with the progression of modeled monthly inland flood extents, it might be possible to identify areas along this

  2. Condition factor and diet of Chrysichthys nigrodigitatus and Chrysichthys auratus (Siluriformes: Bagridae from Aiba Reservoir, Iwo, Nigeria

    Directory of Open Access Journals (Sweden)

    Oluwatosin Ebenezer Atobatele

    2011-09-01

    Full Text Available Chrysichthys nigrodigitatus and C. auratus are important, highly valued and threatened freshwater species. To contribute with their ecological knowledge, the condition factor and diet of these two congeneric species were studied between April 2005 and April 2006. Food items of fish were evaluated by occurrence and numerical abundance methods, and the possible changes among sexes, seasons and sizes were considered. Results showed that generally C. nigrodigitatus were better conditioned than C. auratus. The males of C. nigrodigitatus and females of C. auratus were in better condition than their respective opposite sex throughout the year, and during the wet season compared to the dry. The food items of C. nigrodigitatus and C. auratus were similar and comprised twelve species belonging to five groups: Insecta (three species, Crustacea (five species, Arachnida (one species, Rotifera (one species and Mollusca (two species. Other food items included fish scales, unidentified green eggs, plant parts, detritus and sand. Insecta and Crustacea dominated the food items in both species. For C. nigrodigitatus, insect consumption increased with fish size, while Crustacea items decreased (from 89.59% for 8.1cm - 12.0cm size class to 1.58% for 20.1cm - 26.0cm size class. However, while C. auratus smaller sized fish preferred Crustacea (98.72% for 8.1cm -12.0cm size class, larger sized fish had both groups in relatively similar amounts. Schoener Overlap Index for both species and between seasons is 1.00. Diet breadth ranged from 0.00-1.47 for C. nigrodigitatus and 0.00-1.32 for C. auratus. Food Richness ranged from 0.00-1.44 for both species. Gut Repletion Index for C. nigrodigitatus and C. auratus are 76.39% and 76.27% respectively. Although, there is considerable similarity and overlap in the utilization of food resource for both coexisting species, condition factor and feeding behavior suggest strategies to reduce intra- and inter-specific competition. Rev

  3. Well testing in gas hydrate reservoirs

    OpenAIRE

    Kome, Melvin Njumbe

    2015-01-01

    Reservoir testing and analysis are fundamental tools in understanding reservoir hydraulics and hence forecasting reservoir responses. The quality of the analysis is very dependent on the conceptual model used in investigating the responses under different flowing conditions. The use of reservoir testing in the characterization and derivation of reservoir parameters is widely established, especially in conventional oil and gas reservoirs. However, with depleting conventional reserves, the ...

  4. FRACTURED PETROLEUM RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Abbas Firoozabadi

    1999-06-11

    The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly

  5. Performance analysis and comparison of an Atkinson cycle coupled to variable temperature heat reservoirs under maximum power and maximum power density conditions

    International Nuclear Information System (INIS)

    Wang, P.-Y.; Hou, S.-S.

    2005-01-01

    In this paper, performance analysis and comparison based on the maximum power and maximum power density conditions have been conducted for an Atkinson cycle coupled to variable temperature heat reservoirs. The Atkinson cycle is internally reversible but externally irreversible, since there is external irreversibility of heat transfer during the processes of constant volume heat addition and constant pressure heat rejection. This study is based purely on classical thermodynamic analysis methodology. It should be especially emphasized that all the results and conclusions are based on classical thermodynamics. The power density, defined as the ratio of power output to maximum specific volume in the cycle, is taken as the optimization objective because it considers the effects of engine size as related to investment cost. The results show that an engine design based on maximum power density with constant effectiveness of the hot and cold side heat exchangers or constant inlet temperature ratio of the heat reservoirs will have smaller size but higher efficiency, compression ratio, expansion ratio and maximum temperature than one based on maximum power. From the view points of engine size and thermal efficiency, an engine design based on maximum power density is better than one based on maximum power conditions. However, due to the higher compression ratio and maximum temperature in the cycle, an engine design based on maximum power density conditions requires tougher materials for engine construction than one based on maximum power conditions

  6. Mechanical changes caused by CO2-driven cement dissolution in the Morrow B Sandstone at reservoir conditions: Experimental observations

    Science.gov (United States)

    Wu, Z.; Luhmann, A. J.; Rinehart, A. J.; Mozley, P.; Dewers, T. A.

    2017-12-01

    Carbon Capture, Utilization and Storage (CCUS) in transmissive reservoirs is a proposed mechanism in reducing CO2 emissions. Injection of CO2 perturbs reservoir chemistry, and can modify porosity and permeability and alter mineralogy. However, little work has been done on the coupling of rock alteration by CO2 injection and the mechanical integrity of the reservoir. In this study, we perform flow-through experiments on calcite- and dolomite-cemented Pennsylvanian Morrow B Sandstone (West Texas, USA) cores. We hypothesize that poikilotopic calcite cement has a larger impact on chemo-mechanical alteration than disseminated dolomite cement given similar CO2 exposure. With one control brine flow-through experiment and two CO2-plus-brine flow-through experiments for each cement composition, flow rates of 0.1 and 0.01 ml/min were applied under 4200 psi pore fluid pressure and 5000 psi confining pressure at 71 °C. Fluid chemistry and permeability data enable monitoring of mineral dissolution. Ultrasonic velocities were measured pre-test using 1.2 MHz source-receiver pairs at 0.5 MPa axial load and show calcite-cemented samples with higher dynamic elastic moduli than dolomite-cemented samples. Velocities measured post-experiment will identify changes from fluid-rock interaction. We plan to conduct cylinder-splitting destructive mechanical test (Brazil test) to measure the pristine and altered tensile strength of different cemented sandstones. The experiments will identify extents to which cement composition and texture control chemo-mechanical degradation of CCUS reservoirs. Funding for this project is provided by the U.S. Department of Energy's (DOE) National Energy Technology Laboratory (NETL) through the Southwest Regional Partnership on Carbon Sequestration (SWP) under Award No. DE-FC26-05NT42591. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of

  7. Large scale in-situ BOrehole and Geofluid Simulator (i.BOGS) for the development and testing of borehole technologies at reservoir conditions

    Science.gov (United States)

    Duda, Mandy; Bracke, Rolf; Stöckhert, Ferdinand; Wittig, Volker

    2017-04-01

    A fundamental problem of technological applications related to the exploration and provision of geothermal energy is the inaccessibility of subsurface processes. As a result, actual reservoir properties can only be determined using (a) indirect measurement techniques such as seismic surveys, machine feedback and geophysical borehole logging, (b) laboratory experiments capable of simulating in-situ properties, but failing to preserve temporal and spatial scales, or vice versa, and (c) numerical simulations. Moreover, technological applications related to the drilling process, the completion and cementation of a wellbore or the stimulation and exploitation of the reservoir are exposed to high pressure and temperature conditions as well as corrosive environments resulting from both, rock formation and geofluid characteristics. To address fundamental and applied questions in the context of geothermal energy provision and subsurface exploration in general one of Europe's largest geoscientific laboratory infrastructures is introduced. The in-situ Borehole and Geofluid Simulator (i.BOGS) allows to simulate quasi scale-preserving processes at reservoir conditions up to depths of 5000 m and represents a large scale pressure vessel for iso-/hydrostatic and pore pressures up to 125 MPa and temperatures from -10°C to 180°C. The autoclave can either be filled with large rock core samples (25 cm in diameter, up to 3 m length) or with fluids and technical borehole devices (e.g. pumps, sensors). The pressure vessel is equipped with an ultrasound system for active transmission and passive recording of acoustic emissions, and can be complemented by additional sensors. The i.BOGS forms the basic module for the Match.BOGS finally consisting of three modules, i.e. (A) the i.BOGS, (B) the Drill.BOGS, a drilling module to be attached to the i.BOGS capable of applying realistic torques and contact forces to a drilling device that enters the i.BOGS, and (C) the Fluid.BOGS, a geofluid

  8. Reservoir management

    International Nuclear Information System (INIS)

    Satter, A.; Varnon, J.E.; Hoang, M.T.

    1992-01-01

    A reservoir's life begins with exploration leading to discovery followed by delineation of the reservoir, development of the field, production by primary, secondary and tertiary means, and finally to abandonment. Sound reservoir management is the key to maximizing economic operation of the reservoir throughout its entire life. Technological advances and rapidly increasing computer power are providing tools to better manage reservoirs and are increasing the gap between good and neutral reservoir management. The modern reservoir management process involves goal setting, planning, implementing, monitoring, evaluating, and revising plans. Setting a reservoir management strategy requires knowledge of the reservoir, availability of technology, and knowledge of the business, political, and environmental climate. Formulating a comprehensive management plan involves depletion and development strategies, data acquisition and analyses, geological and numerical model studies, production and reserves forecasts, facilities requirements, economic optimization, and management approval. This paper provides management, engineers geologists, geophysicists, and field operations staff with a better understanding of the practical approach to reservoir management using a multidisciplinary, integrated team approach

  9. Hotwater Geochemistry for Interpreting The Condition of Geothermal Reservoir, Dieng Plateau Case, Banjarnegara-Wonosobo Regency, Central Java

    Directory of Open Access Journals (Sweden)

    Yuris Ramadhan

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i2.158The researched area, located in the Dieng Plateau, is included into the Holocene Dieng Volcanic Rock Unit. The regional structure in this area is originated from the major caldera with local fault having orientation of SE - NW. Surface manifestations found in the researched area are hot springs located in Bitingan, Sileri, Siglagah, Pulosari, Kaliputih, and Sikidang. Fumaroles occur in Candradimuka and Pagerkandang and mud pools are located in Sileri and Sikidang craters. Temperatures of the hot springs ranges from 43 C to 61 C, pH of 6 - 7, and their conductivity are of 38-78 MeV. The type of hotwater is a mixture of bicarbonate, sulfate, and chloride sulfate deriving from condensation of steam. Based on a relative composition of Cl-Li-B, the hot water is originated from four different reservoirs with different rock associations, while their reservoir temperatures vary from 225 C to 300 C.

  10. Infection of Siberian chipmunks (Tamias sibiricus barberi) with Borrelia sp. reveals a low reservoir competence under experimental conditions.

    Science.gov (United States)

    Bonnet, Sarah; Choumet, Valérie; Masseglia, Sébastien; Cote, Martine; Ferquel, Elisabeth; Lilin, Thomas; Marsot, Maud; Chapuis, Jean-Louis; Vourc'h, Gwenaël

    2015-04-01

    Reservoir competence is a key parameter in understanding the role of host species in the epidemiology of multi-host-especially vector-borne-pathogens. With this aim in view, we studied the reservoir competence of the Siberian chipmunk (Tamias sibiricus barberi) recently introduced into Europe, for the multi-host tick-borne bacteria, Borrelia burgdorferi sl, the agent of Lyme borreliosis. T. sibiricus were experimentally exposed to bites from Ixodes ricinus ticks infected with Borrelia burgdorferi sensu stricto and Borrelia afzelii, with subsequent assessment of bacteremia and antibody responses. Borrelia was detected in chipmunk blood samples, ear biopsies and organ necropsies, and in nymphs used for xenodiagnosis (at one and six months after the initial chipmunk infection) via both serological and molecular methods. In total, eight out of twelve chipmunks showed evidence of infection by Borrelia sp., either by ELISA or PCR. Five chipmunks developed an immune response against the bacteria one month after infection. Borrelia infection in at least one organ was observed in seven animals at 14, 38, 93 or 178 days post-infection. Xenodiagnosis was positive for one chipmunk at 38 days, but no longer at 178 days post-infection. Four chipmunks remained uninfected, despite similar infection pressures to those observed in the field. Taken together, these results suggest that chipmunks can be infected through Borrelia-infected tick bites, and can transmit Borrelia to nymphs, but do not remain persistently infected. Copyright © 2015 Elsevier GmbH. All rights reserved.

  11. Estimating long-term evolution of fine sediment budget in the Iffezheim reservoir using a simplified method based on classification of boundary conditions

    Science.gov (United States)

    Zhang, Qing; Hillebrand, Gudrun; Hoffmann, Thomas; Hinkelmann, Reinhard

    2017-04-01

    The Iffezheim reservoir is the last of a series of reservoirs on the Upper Rhine in Germany. Since its construction in 1977, approximately 115,000 m3 of fine sediments accumulate annually in the weir channel (WSA Freiburg, 2011). In order to obtain detailed information about the space-time development of the topography, the riverbed evolution was measured using echo sounding by the German Federal Waterways and Shipping Administration (WSV). 37 sets of sounding data, which have been obtained between July 2000 and February 2011, were used in this research. In a previous work, the morphodynamic processes in the Iffezheim reservoir were investigated using a high-resolution 3D model. The 3D computational fluid dynamic software SSIIM II (Olsen, 2014) was used for this purpose (Zhang et al., 2015). The model was calibrated using field measurements. A computational time of 14.5 hours, using 24 cores of a 2.4 GHz reference computer, was needed for simulating a period of three months on a grid of 238,013 cells. Thus, the long-term (e.g. 30 years) simulation of morphodynamics of the fine sediment budget in the Iffezheim reservoir with this model is not feasible. A low complexity approach of "classification of the boundary conditions of discharge and suspended sediment concentration" was applied in this research for a long-term numerical simulation. The basic idea of the approach is to replace instationary or quasi-steady simulations of deposition by a limited series of stationary ones. For these, daily volume changes were calculated considering representative discharge and concentration. Representative boundary conditions were determined by subdividing time series of discharge and concentration into classes and using central values per class. The amount of the deposition in the reservoir for a certain period can then be obtained by adding up the calculated daily depositions. This approach was applied to 10 short-term periods, between two successive echo sounding measurements

  12. Hydrological controls on cascade reservoirs regulating phosphorus retention and downriver fluxes.

    Science.gov (United States)

    Lu, Ting; Chen, Nengwang; Duan, Shuiwang; Chen, Zhuhong; Huang, Bangqin

    2016-12-01

    Many coastal rivers have a system of cascade reservoirs, but the role of these reservoirs in regulating nutrient transport from watershed to coast is still unknown. In this study, phosphorus (P) in surface water and top sediment was investigated along the North Jiulong River (southeast China) under three hydrological conditions (high flow, medium flow and low flow) in 2012-2013, and P dynamics in a cascade reservoir (Xipi Reservoir) were studied on a monthly scale. Results showed that the concentrations of dissolved reactive phosphorus (DRP) consistently decreased longitudinally in the upper river with the lowest values observed in the section of cascade reservoirs, likely due to tributary inputs and in situ uptakes. The decrease was most rapid during base flow when DRP was highest in the free-flowing river section and lowest in cascade reservoirs. Results from monthly monitoring on the Xipi Reservoir showed general downriver decreases in DRP, total particulate phosphorus (TPP) and total phosphorus (TP) in the riverine zone and transition zone. Mass balance results on an annual basis suggest that the Xipi Reservoir (lacustrine zone) was an overall sink for TPP (6 % retention) but somewhat a source of DRP (-0.3 %) with TP retention (1 %). Even scaled up to the whole cascade reservoir system, P retention was low compared with worldwide reservoirs, which we ascribe to the high P loading and short hydraulic residence time. Nevertheless, major processes controlling P retention in coastal rivers with cascade reservoirs varied from sedimentation in the dry-cold season to biotic transformation in the wet-warm season, thereby affecting loading and composition of P from watershed to the coast. This study highlights the hydrological controls on the role of cascade reservoirs in regulating P retention and downriver fluxes in different seasons.

  13. Hydrological and environmental conditions as key drivers for spatial and seasonal changes in PCDD/PCDF concentrations, transport and deposition along urban cascade reservoirs.

    Science.gov (United States)

    Urbaniak, Magdalena; Skowron, Aleksandra; Zieliński, Marek; Zalewski, Maciej

    2012-09-01

    To investigate the drivers for transport and deposition of 17 2,3,7,8-substituted PCDDs/PCDFs along an urban river, water samples from five reservoirs located along the river course were collected in January and July 2008. The concentrations of 17 congeners of PCDD/PCDF were determined and compared to environmental - physical, chemical and biological - conditions. The obtained data revealed that the concentration of the sum of toxic PCDDs/PCDFs in water samples differ between reservoirs as well as between seasons, ranging from 12.04 pg L(-1) in UP (first in the cascade) to 1327.94 pg L(-1) in PR (last in the cascade) during winter of 2008; and from 34.94 pg L(-1) in UP to 1352.50 pg L(-1) in TR (next to last) in summer 2008. In comparison, water samples collected from the river had a concentration several times lower at the first two sites (sites no. 1 and 4) and no detectable values at the last three stations (sites no. 7, 8, 10). The obtained data demonstrated strong or moderate correlations between the sum of 17 PCDDs/PCDFs and TEQ in reservoir water samples and physical, chemical and biological conditions, such as: Mg(2+) (R=0.82; R=0.80, respectively), SO(4)(2-) (R=0.80; R=0.80, respectively), K(+) (R=0.80; R=0.80, respectively), Ca(2+) (R=0.67, R=0.70, respectively), OSM (R=0.63, R=0.70, respectively). In addition, the positive strong correlation between TEQ concentrations and the water temperature (R=0.63) and chlorophyll a content (R=0.90) was noted. The violent weather conditions occurred during the research season with periods of intensive storm events (up to 32 mm in mid July), and thus the increased river flow velocity (up to 0.45 m(3)s(-1)) could have a direct and indirect influence on PCDDs/PCDFs concentration through changes in the sedimentation/resuspension ratio and consequently in transport, deposition and degradation processes along the river/reservoirs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Study of different factors affecting the electrical properties of natural gas reservoir rocks based on digital cores

    International Nuclear Information System (INIS)

    Jiang, Liming; Sun, Jianmeng; Wang, Haitao; Liu, Xuefeng

    2011-01-01

    The effects of the wettability and solubility of natural gas in formation water on the electrical properties of natural gas reservoir rocks are studied using the finite element method based on digital cores. The results show that the resistivity index of gas-wet reservoir rocks is significantly higher than that of water-wet reservoir rocks in the entire range of water saturation. The difference between them increases with decreasing water saturation. The resistivity index of natural gas reservoir rocks decreases with increasing additional conduction of water film. The solubility of natural gas in formation water has a dramatic effect on the electrical properties of reservoir rocks. The resistivity index of reservoir rocks increases as the solubility of natural gas increases. The effect of the solubility of natural gas on the resistivity index is very obvious under conditions of low water saturation, and it becomes weaker with increasing water saturation. Therefore, the reservoir wettability and the solubility of natural gas in formation water should be considered in defining the saturation exponent

  15. Encapsulated microsensors for reservoir interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Eddie Elmer; Aines, Roger D.; Spadaccini, Christopher M.

    2016-03-08

    In one general embodiment, a system includes at least one microsensor configured to detect one or more conditions of a fluidic medium of a reservoir; and a receptacle, wherein the receptacle encapsulates the at least one microsensor. In another general embodiment, a method include injecting the encapsulated at least one microsensor as recited above into a fluidic medium of a reservoir; and detecting one or more conditions of the fluidic medium of the reservoir.

  16. Monitoring spatiotemporal variations in nutrients in a large drinking water reservoir and their relationships with hydrological and meteorological conditions based on Landsat 8 imagery.

    Science.gov (United States)

    Li, Yuan; Zhang, Yunlin; Shi, Kun; Zhu, Guangwei; Zhou, Yongqiang; Zhang, Yibo; Guo, Yulong

    2017-12-01

    Nutrient enrichment is a major cause of water eutrophication, and variations in nutrient enrichment are influenced by environmental changes and anthropogenic activities. Accurately estimating nutrient concentrations and understanding their relationships with environmental factors are vital to develop nutrient management strategies to mitigate eutrophication. Landsat 8 Operational Land Imager (OLI) data is used to estimate nutrient concentrations and analyze their responses to hydrological and meteorological conditions. Two well-accepted empirical models are developed and validated to estimate the total nitrogen (TN) and total phosphorus (TP) concentrations (C TN and C TP ) in the Xin'anjiang Reservoir using Landsat 8 OLI data from 2013 to 2016. Spatially, C TN decreased from the transition zone to the riverine zone and the lacustrine zone. On the other hand, C TP decreased from the riverine zone to the transition zone and the lacustrine zone. Temporally, C TN displayed elevated values during the late fall and winter and had lower values during the summer and early fall, whereas C TP was higher during the spring and lower during the winter. Among the environmental factors, the rainfall and the inflow rate have strong positive correlations with the nutrient concentrations. TN is more sensitive to meteorological factors (wind speed, temperature, sunshine duration), and the spatial driving forces vary among the different sections of the reservoir. However, TP is more easily influenced by human activities, such as fishery and agricultural activities. Current results would improve our understanding of the drivers of nutrients spatiotemporal variability and the approach in this study can be applicable to other similar reservoir to develop related strategies to mitigate eutrophication. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. CO2 Reaction Induced Wettability Alteration and its Impacts on CO2 Storage: Pore to Core Scale Reservoir Condition Experimental Studies

    Science.gov (United States)

    Wan, J.; Tokunaga, T. K.; Kim, Y.; Jung, J.; Kim, T.; Dong, W.

    2013-12-01

    Wettability of the mineral surfaces plays an important role in subsurface multiphase flow and transport. Wettability affects the capillary pressure-saturation (Pc- S) relations, relative permeability (kr) of each fluid phase, and relative phase occupancy in reservoir pores. Although wettability issues have been studied extensively in other fields, significant knowledge gaps remain when applying the existing understanding to geological carbon sequestration; due largely to the unique physical-chemical properties of supercritical (sc) CO2 relative to other common non-wetting fluids such as air and oil. Here, we report our recent progress on wettability alteration upon reaction with CO2 and the resulting differences in capillary trapping of CO2 versus air. (1) Pore Scale Studies. There are conflict predictions in the literature concerning the effect of wettability on capillary trapping; some find that larger contact angles lead to lower capillary trapping while others have found opposite behavior. We hypothesized that spontaneous imbibition becomes energetically unfavorable with decreased wettability, so that increased residual trapping of scCO2 should occur during the post-injection inbibition stage. We developed a laboratory high-pressure and elevated temperature microscopic-micromodel system that is capable of controlling fine scale capillary pressure of scCO2-brine, and enabled us to conduct imbibition under controlled capillary pressures at the pore scale. We found that the de-wetting enhanced scCO2 capillary trapping is significant. These results suggest that scCO2 reaction induced dewetting can result in higher degrees of CO2 residual trapping in the post-injection stage than previously predicted. (2) Core Scale Studies. Capillary scaling is used routinely to predict Pc(S) relations for scCO2-brine systems at field scale, based on relations measured with air-water or mercury porosimetry. However, scaling-based predictions for CO2-brine systems have not been

  18. Integrase-independent HIV-1 infection is augmented under conditions of DNA damage and produces a viral reservoir

    International Nuclear Information System (INIS)

    Ebina, Hirotaka; Kanemura, Yuka; Suzuki, Yasutsugu; Urata, Kozue; Misawa, Naoko; Koyanagi, Yoshio

    2012-01-01

    HIV-1 possesses a viral protein, integrase (IN), which is necessary for its efficient integration in target cells. However, it has been reported that an IN-defective HIV strain is still capable of integration. Here, we assessed the ability of wild type (WT) HIV-1 to establish infection in the presence of IN inhibitors. We observed a low, yet clear infection of inhibitor-incubated cells infected with WT HIV which was identical to cells infected with IN-deficient HIV, D64A. Furthermore, the IN-independent integration could be enhanced by the pretreatment of cells with DNA-damaging agents suggesting that integration is mediated by a DNA repair system. Moreover, significantly faster viral replication kinetics with augmented viral DNA integration was observed after infection in irradiated cells treated with IN inhibitor compared to nonirradiated cells. Altogether, our results suggest that HIV DNA has integration potential in the presence of an IN inhibitor and may serve as a virus reservoir.

  19. Integrase-independent HIV-1 infection is augmented under conditions of DNA damage and produces a viral reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Ebina, Hirotaka, E-mail: hebina@virus.kyoto-u.ac.jp; Kanemura, Yuka; Suzuki, Yasutsugu; Urata, Kozue; Misawa, Naoko; Koyanagi, Yoshio

    2012-05-25

    HIV-1 possesses a viral protein, integrase (IN), which is necessary for its efficient integration in target cells. However, it has been reported that an IN-defective HIV strain is still capable of integration. Here, we assessed the ability of wild type (WT) HIV-1 to establish infection in the presence of IN inhibitors. We observed a low, yet clear infection of inhibitor-incubated cells infected with WT HIV which was identical to cells infected with IN-deficient HIV, D64A. Furthermore, the IN-independent integration could be enhanced by the pretreatment of cells with DNA-damaging agents suggesting that integration is mediated by a DNA repair system. Moreover, significantly faster viral replication kinetics with augmented viral DNA integration was observed after infection in irradiated cells treated with IN inhibitor compared to nonirradiated cells. Altogether, our results suggest that HIV DNA has integration potential in the presence of an IN inhibitor and may serve as a virus reservoir.

  20. 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.

  1. Demulsification of W/O emulsion at petroleum field and reservoir conditions using some demulsifiers based on polyethylene and propylene oxides

    Directory of Open Access Journals (Sweden)

    A.M. Alsabagh

    2016-12-01

    Full Text Available In this work, polymer molecules of alkene oxides diesters with varying HLB values and molecular weights (ED1, ED2, ED3, PD1, PD2 and PD3 were synthesized, elsewhere (Alsabagh et al., 2016. The demulsification efficiency was evaluated at field and reservoir conditions. At field conditions (60 °C and 1 atm the data revealed that the maximum demulsification efficiency was obtained by ED3 and PD3 at 60 °C, 600 ppm after 55 and 40 min, respectively. At reservoir conditions (85 °C and 5000 psi, the PD3 and ED3 showed also the maximum demulsification efficiency was 76% and 70%, respectively, in spite of the 2% from the blank emulsion (12% BS&W separated after 7 days. The interfacial tension (IFT at the crude oil/water interface was measured for PD3 and ED3. From the results, it was found that the values of IFT were 0.7 and 0.8 mN m−1 respectively. The rheological behavior of the same demulsifiers was investigated. The results showed that the demulsifiers PD3 and ED3 enhance the dynamic viscosities (3.9 and 3.8 mPa s, respectively and the (τB yield values were 0.77 and 1.23 Pa s, respectively at temperature 85 °C, whereas, they were 3.95 mPa s and 1.5 Pa s for the blank emulsion sample.

  2. Sticky or Slippery Wetting: Network Formation Conditions Can Provide a One-Way Street for Water Flow on Platinum-cured Silicone.

    Science.gov (United States)

    Wang, Chenyu; Nair, Sithara S; Veeravalli, Sharon; Moseh, Patricia; Wynne, Kenneth J

    2016-06-08

    In the course of studies on Sylgard 184 (S-PDMS), we discovered strong effects on receding contact angles (CAs), θrec, while cure conditions have little effect on advancing CAs. Network formation at high temperatures resulted in high θadv of 115-120° and high θrec ≥ 80°. After network formation at low temperatures (≤25 °C), θadv was still high but θrec was 30-50°. Uncertainty about compositional effects on wetting behavior resulted in similar experiments with a model D(V)D(H) silicone elastomer (Pt-PDMS) composed of a vinyl-terminated poly(dimethylsiloxane) (PDMS) base and a polymeric hydromethylsilane cross-linker. Again, network formation at high temperature (∼100 °C) resulted in high CAs, while low-temperature curing retained high advancing CAs but gave low receding CAs (θrec 30-50°). These changes in receding CAs translate to strong effects on water adhesion, wp, which is the actual work required to separate a liquid (water) from a surface: wp ∝ (1 + θrec). When the values θrec 84° for high-temperature and θrec 50° for low-temperature network formation are used, wp is ∼1.5 times higher for curing at low temperature. The origin of low receding contact angles was investigated by attenuated total reflectance IR spectroscopy. Absorptions for Si-OH hydrogen-bonded to water (3350 cm(-1)) were stronger for low- versus high-temperature curing. This result is attributed to faster hydrosilylation during curing at higher temperatures that consumes Si-H before autoxidation to Si-OH. Sharp bands at 3750 and 3690 cm(-1) due to isolated -Si-OH are more prominent for Pt-PDMS than those for S-PDMS, which may be due to an effect of functionalized nanofiller. To explore the impact of wp on water droplet flow, gradient coatings of S-PDMS and Pt-PDMS elastomers were prepared by coating a slide, maintaining opposite ends at high and low temperatures and thus forming a thermal gradient. When the slide was tilted, a droplet moved easily on the high

  3. Wet-dog shake

    Science.gov (United States)

    Dickerson, Andrew; Mills, Zack; Hu, David

    2010-11-01

    The drying of wet fur is a critical to mammalian heat regulation. We investigate experimentally the ability of hirsute animals to rapidly oscillate their bodies to shed water droplets, nature's analogy to the spin cycle of a washing machine. High-speed videography and fur-particle tracking is employed to determine the angular position of the animal's shoulder skin as a function of time. We determine conditions for drop ejection by considering the balance of surface tension and centripetal forces on drops adhering to the animal. Particular attention is paid to rationalizing the relationship between animal size and oscillation frequency required to self-dry.

  4. Methane mitigation in transplanting and direct-wet seeding rice fields treated with fertilizers under condition of alternately flooding and soil aerating

    Directory of Open Access Journals (Sweden)

    Sanwangsi, M.

    2006-05-01

    Full Text Available Rice is main staple crop of the world. Growing rice in flooded water entails methane (CH4 emission. CH4 is one of greenhouse gases contributing to global warming. The experiment aimed to clarify the influence of fertilizer and water management on total methane emission (TME, methane mitigation and rice yields (RY. The experimental design was a split - split plot with 3 replications taking 2 cultivation in main plots, transplanting (TP rice and direct-wet seeding (DWS rice fields; 2 basal fertilizers, 16-16-8, 20 kg/rai and chicken manure pallet (CMP, 105 kg/rai in sub plots; and 3 top dressing fertilizers 1 none, 2 urea (46% N, 15 kg/rai and 3 ammonium sulfate (AS, 21% N, 30 kg/rai in sub-sub plots. It also examined relationship between quantity of paddy-soil water, TME and RY of both cultivations. Methane emission rate (MER occurred during the whole growth period and was characterized by 2 large peaks: one from after transplanting or broadcasting to maximum tillering stage and the other from flowering to yellow ripening stage. Rapid declines of MER were dictated by soil aeration recognized as 3-5 days cracks. In TP rice plot based with CMP, 105 kg/rai, topped with AS, 30 kg/rai, TME decreased to 73.0% and RY increased to 14.7% over that of untreated plots with top dressing fertilizer, while in that topped with urea, 15 kg/rai, TME decreased to 68.9% and RY increased to 16.9%. In all of DWS rice plots which were topped with AS or urea, declines of TME ranged from 27.3 to 56.4% and increase of RY ranged from 31.3 to 47.9% over those without top dressing. In both TP and DWS plots, TMEs were closely correlated with the quantity of paddy-soil water (r = 0.83 and 0.86, respectively and with submergence days (r = 0.94 and 0.89, respectively. Hence, saturated condition in paddy soil is a primary factor for methanogenesis. Moreover, for TP rice, the relationship between TME and RY was weakly positive (r = 0.16, whereas that for DWS rice was obviously

  5. Reactivity of hydrocarbons in response to injection of a CO2/O2 mixture under depleted reservoir conditions: experimental and numerical modeling

    International Nuclear Information System (INIS)

    Pacini-Petitjean, Claire

    2015-01-01

    The geological storage of CO 2 (CO 2 Capture-Storage - CCS) and the Enhanced Oil Recovery (EOR) by CO 2 injection into petroleum reservoirs could limit CO 2 atmospheric accumulation. However, CO 2 can be associated with oxygen. To predict the hydrocarbon evolution under these conditions involves the study of oxidation mechanisms. Oxidation experiment and kinetic detailed modeling were carried out with pure compounds. The comparison between experimental and modeling results led to the construction of a hydrocarbon oxidation kinetic model and emphasized the parameters leading to auto ignition. The good agreement between our experiments and modeling are promising for the development of a tool predicting the critical temperature leading to auto-ignition and the evolution of hydrocarbon composition, to estimate the stability of a petroleum system in CO 2 injection context. (author) [fr

  6. Mercury speciation in piscivorous fish from mining-impacted reservoirs

    Science.gov (United States)

    Kuwabara, J.S.; Arai, Y.; Topping, B.R.; Pickering, I.J.; George, G.N.

    2007-01-01

    Guadalupe Reservoir (GUA), California, and Lahontan Reservoir (LAH), Nevada, U.S. are both affected either directly or indirectly by the legacy of gold and silver mining in the Sierra Nevada during the nineteenth century. Analysis of total mercury in fish from these lentic systems consistently indicate elevated concentrations (>1 ??g??g-1 wet weight; hereinafter, all concentrations are reported as wet weight unless indicated otherwise) well above the U.S. Environmenal Protection Agency's human consumption advisory level for fish (hybrid striped bass from GUA and LAH were performed to determine predominant chemical species of mercury accumulated by these high-trophic-level piscivores that are exposed to elevated mercury through trophic transfer in mining-impacted lentic systems. Despite distinct differences in mercury source, the proximity of the source, and concentrations of complexing ligands, results of XANES analysis clearly indicated that mercury accumulated in these individual fish from the two reservoirs were dominated by methylmercury cysteine complexes. These findings are consistent with results from commercial fish species inhabiting marine environments which are presumed to include differing mercury sources (e.g., atmospheric, hydrothermal, or benthic). The dominance of methylmercury cysteine complexes in muscle tissues of fish obtained from such contrasting environments and exposure conditions suggests that a generic toxicological model for the consumption of fish could be applicable over a wide range of ecologic settings. ?? 2007 American Chemical Society.

  7. Seasonal effect on trace metal elements behaviour in a reservoir of northern Thailand.

    Science.gov (United States)

    Grellier, S; Janeau, J L; Thothong, W; Boonsaner, A; Bonnet, M P; Lagane, C; Seyler, P

    2013-07-01

    Trace metal elements (TME) can be real threats for living organisms. However, few studies dealt with TME in reservoirs in rural areas where farming practises could induce negative effects. Mae Thang reservoir (northern Thailand) has been studied for 3 years to understand the seasonal behaviour of dissolved TME: Fe, Mn, Cd, Al, Pb, V, Cr, Co, Ni, Cu, Zn, Mo, U and As and associated physicochemical parameters. In situ measurements of these parameters were done during the dry and the wet seasons as well as water samples along the water column for further analyses and TME determination by inductively coupled plasma-mass spectrometry (ICP-MS). In the dry season, the water column was characterized by a strong stratification and anoxic conditions in the hypolimnion. High rain and water input from the watershed during the wet season induced mixing of the water. All TME, except Ni, Co and Cr were less concentrated in the wet season indicating a dilution effect by water input. There was thus no important dissolved pollution coming from the watershed. The anoxic conditions in the dry season enhanced the reduction of Fe and Mn and the desorption processes. Depth, and thus oxic-anoxic conditions were the main drivers of TME in the dry season, while in the wet season, dissolution processes from parent rocks of watershed were favoured. The average concentrations of TME in the reservoir were in the limit of the international and Thai standards. Only localized values in the bottom of the reservoir for Fe and Mn were higher than the limits.

  8. Lithium wetting of stainless steel for plasma facing components

    Science.gov (United States)

    Skinner, C. H.; Capece, A. M.; Roszell, J. P.; Koel, B. E.

    2014-10-01

    Ensuring continuous wetting of a solid container by the liquid metal is a critical issue in the design of liquid metal plasma facing components foreseen for NSTX-U and FNSF. Ultrathin wetting layers may form on metallic surfaces under ultrahigh vacuum (UHV) conditions if material reservoirs are present from which spreading and wetting can start. The combined scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and ion beam etching capabilities of a Scanning Auger Microprobe (SAM) have been used to study the spreading of lithium films on stainless steel substrates. A small (mm-scale) amount of metallic lithium was applied to a stainless steel surface in an argon glove box and transferred to the SAM. Native impurities on the stainless steel and lithium surfaces were removed by Ar+ ion sputtering. Elemental mapping of Li and Li-O showed that surface diffusion of Li had taken place at room temperature, well below the 181°C Li melting temperature. The influence of temperature and surface oxidation on the rate of Li spreading on stainless steel will be reported. Support was provided through DOE Contract Number DE-AC02-09CH11466.

  9. Methane mitigation in transplanting and direct-wet seeding rice fields treated with fertilizers under condition of alternately flooding and soil aerating

    OpenAIRE

    Sanwangsi, M.; Saenjan, P.; Prongjunteak, K.

    2006-01-01

    Rice is main staple crop of the world. Growing rice in flooded water entails methane (CH4) emission. CH4 is one of greenhouse gases contributing to global warming. The experiment aimed to clarify the influence of fertilizer and water management on total methane emission (TME), methane mitigation and rice yields (RY). The experimental design was a split - split plot with 3 replications taking 2 cultivation in main plots, transplanting (TP) rice and direct-wet seeding (DWS) rice fields; 2 basal...

  10. Effect of habitat conditions on parasite infection in 0+juvenile perch (Perca fluviatilis L.) in two Czech reservoirs

    Czech Academy of Sciences Publication Activity Database

    Francová, K.; Ondračková, Markéta

    2014-01-01

    Roč. 721, č. 1 (2014), s. 57-66 ISSN 0018-8158 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Parasite * Intermediate host * Food availability * Habitat conditions * Lentic * Littoral Subject RIV: EG - Zoology Impact factor: 2.275, year: 2014

  11. Theoretical and practical meaning of ecological morphophysiological research og fish reproduction in the reservoir with ecology changed conditions

    Directory of Open Access Journals (Sweden)

    N. I. Rabazanov

    2009-01-01

    Full Text Available Fish reproduction research showed that the change of existence conditions changes the character of sexual cell growth changes. Evident changes in the duration of protoplasmatic growth are observed as well as the asynchronism degree of sexual cells and their development rate during annual period.

  12. Dissolved methane in Indian freshwater reservoirs

    Digital Repository Service at National Institute of Oceanography (India)

    Narvenkar, G.; Naqvi, S.W.A.; Kurian, S.; Shenoy, D.M.; Pratihary, A.K.; Naik, H.; Patil, S.; Sarkar, A.; Gauns, M.

    Emission of methane (CH4), a potent greenhouse gas, from tropical reservoirs is of interest because such reservoirs experience conducive conditions for CH4 production through anaerobic microbial activities. It has been suggested that Indian...

  13. Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4-CO2-H2O) Interactions in Shale Nanopores under Reservoir Conditions: Quarterly Report.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yifeng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-11-01

    Shale is characterized by the predominant presence of nanometer-scale (1-100 nm) pores. The behavior of fluids in those pores directly controls shale gas storage and release in shale matrix and ultimately the wellbore production in unconventional reservoirs. Recently, it has been recognized that a fluid confined in nanopores can behave dramatically differently from the corresponding bulk phase due to nanopore confinement (Wang, 2014). CO2 and H2O, either preexisting or introduced, are two major components that coexist with shale gas (predominately CH4) during hydrofracturing and gas extraction. Note that liquid or supercritical CO2 has been suggested as an alternative fluid for subsurface fracturing such that CO2 enhanced gas recovery can also serve as a CO2 sequestration process. Limited data indicate that CO2 may preferentially adsorb in nanopores (particularly those in kerogen) and therefore displace CH4 in shale. Similarly, the presence of water moisture seems able to displace or trap CH4 in shale matrix. Therefore, fundamental understanding of CH4-CO2-H2O behavior and their interactions in shale nanopores is of great importance for gas production and the related CO2 sequestration. This project focuses on the systematic study of CH4-CO2-H2O interactions in shale nanopores under high-pressure and high temperature reservoir conditions. The proposed work will help to develop new stimulation strategies to enable efficient resource recovery from fewer and less environmentally impactful wells.

  14. Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4-CO2-H2O) Interactions in Shale Nanopores under Reservoir Conditions.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yifeng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-02-01

    Shale is characterized by the predominant presence of nanometer-scale (1-100 nm) pores. The behavior of fluids in those pores directly controls shale gas storage and release in shale matrix and ultimately the wellbore production in unconventional reservoirs. Recently, it has been recognized that a fluid confined in nanopores can behave dramatically differently from the corresponding bulk phase due to nanopore confinement (Wang, 2014). CO2 and H2O, either preexisting or introduced, are two major components that coexist with shale gas (predominately CH4) during hydrofracturing and gas extraction. Note that liquid or supercritical CO2 has been suggested as an alternative fluid for subsurface fracturing such that CO2 enhanced gas recovery can also serve as a CO2 sequestration process. Limited data indicate that CO2 may preferentially adsorb in nanopores (particularly those in kerogen) and therefore displace CH4 in shale. Similarly, the presence of water moisture seems able to displace or trap CH4 in shale matrix. Therefore, fundamental understanding of CH4-CO2-H2O behavior and their interactions in shale nanopores is of great importance for gas production and the related CO2 sequestration. This project focuses on the systematic study of CH4-CO2-H2O interactions in shale nanopores under high-pressure and high temperature reservoir conditions. The proposed work will help to develop new stimulation strategies to enable efficient resource recovery from fewer and less environmentally impactful wells.

  15. Vertical and temporal variation in phytoplankton assemblages correlated with environmental conditions in the Mundaú reservoir, semi-arid northeastern Brazil

    Directory of Open Access Journals (Sweden)

    GAST LIRA

    Full Text Available The goal of this study was to analyse the vertical structure of the phytoplankton community at the Mundaú reservoir, located in the semi-arid region of northeastern Brazil, and to correlate it to environmental conditions over two distinct seasons, dry and rainy. Samples were collected bimonthly at eight depths in the dry and rainy season for analyses of the physical and chemical variables of the water, as well as density, abundance, dominance, species diversity index and equitability of the community. Analysis of variance (ANOVA-two way was used to analyse the vertical and seasonal differences, and Canonical Correspondence Analysis (CCA was used to assess associations between phytoplankton and environmental variables Cylindrospermopsis raciborskii (Woloszynska Seenaya and Subba Raju was the only dominant species and Geitlerinema amphibium (C. Agardh Anagnostidis, Merismopedia punctata Meyen and Synedra rumpens Kützing. Others six taxa were abundant in at least one of the samples. Distinct vertical distribution patterns were observed for the abundant taxa between depths and seasons. The cyanobacteria, with the exception of C. raciborskii, showed similar seasonal patterns, with higher densities in the dry season. The CCA showed a strong correlation between the density of the phytoplanktonic species and abiotic variables. The vertical changes in abundant taxa revealed distinct patterns regulated by the variation in the environmental factors that were directly linked to seasonality, with the success of one or more species being dependent on their life strategies and ecological needs. The present study restates the importance of environmental and seasonal factors for phytoplankton composition and distribution in a freshwater tropical reservoir through a vertical gradient.

  16. Modeled Wet Nitrate Deposition

    Data.gov (United States)

    U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

  17. Designer-Wet Micromodels for Studying Potential Changes in Wettability during Microbial Enhanced Oil Recovery

    Science.gov (United States)

    Armstrong, R. T.; Wildenschild, D.

    2010-12-01

    Microbial Enhanced Oil Recovery (MEOR) is a process where microorganisms are used for tertiary recovery of oil. Some bacteria can facilitate the mobilization of oil through the production of amphiphilic compounds called biosurfactants that reduce the interfacial tension (IFT) between immiscible phases. Additionally, most bacteria have an inclination to colonize surfaces and form biofilm, which can change a reservoir's wetting properties or clog preferential flow paths. Herein, we aim to understand changes in wettability during MEOR under mixed wettability conditions within silicon etched micromodels and to identify the type of oil field (i.e. based on wettability) in which MEOR is likely to be most profitable. To quantify porous media wettability, macro-scale indexes (obtained with techniques such as the Carter or Amott methods) are used regularly. However, these measurements lack the capability for characterization of changes in wettability during MEOR treatment, and only provide macro-scale information. In an effort to understand micro-scale temporal and spatial changes in wettability we measure interfacial curvature from stereo microscope images using level set methods. Curvature, from the perspective of the oil phase, is positive for a concave interface (i.e. water-wet surface) and negative for a convex interface (i.e. oil-wet surface). Thus, shifts in the radius of curvature distribution (i.e. from positive to negative or conversely) are indicative of wettability changes. Both curvature distributions using level-set methods and the Carter method are used to characterize wettability before and after microbial treatment. In preliminary studies aimed at understanding wettability changes due to microbial surface interactions by Bacillus mojavensis JF-2, oil droplets were placed on glass slides suspended in growth media and the resulting contact angle was measured over time. Results showed that a water-wet surface will become more water wet as JF-2 accumulated in

  18. Impact factors on water quality in the confluence zone of the Daning River and the Yangtze River at different hydrological conditions in the Three Gorges Reservoir

    Science.gov (United States)

    Holbach, A.; Wang, L.; Chen, H.; Hu, W.; Schleicher, N.; Zheng, B.; Norra, S.

    2012-04-01

    Water quality of the Three Gorges Reservoir (TGR) in the Yangtze River became a major concern since the first closure of the dam in 2003. Increasing eutrophication and algal bloom events, especially in confluence bays and backwater areas are observed. Substance transport, water exchange and interaction between water masses in confluence areas of tributaries and the Yangtze main stream are of special interest and mainly driven by large scale water level fluctuations and temporal discharge variations in the reservoir. The Daning River, one tributary of the TGR also adjoins to Dachang city and Wushan city which are by backwater of the TGR. In the frame of the Sino-German "Yangtze-Project" [1] water quality data and samples were collected in the Daning River and its confluence zone with the Yangtze River during two fieldtrips in August and December, 2011. Remarkable hydrological changes during the sampling time were present in August whereas conditions in December were rather stable. Water quality data was recorded in-situ and on-line in varying depths with a towed underwater sensor system. The monitored data comprise seven important physico-chemical water parameters (temperature, electrical conductivity, turbidity, dissolved oxygen, oxygen saturation, pH, chlorophyll a) coupled with a 3D positioning system. Geostatistical evaluation and interpolation of the physico-chemical water parameter data was conducted to get 3D distribution models for the parameters in the water bodies. Selective water samples for analysis of inorganic components (anions, cations, nutrients) in the dissolved and particulate phases were taken from different depths by a free flow sampler. Results reveal that pollutant plumes in the water above the thermocline surround the urban areas during the stable conditions of December. In August the degree of mixing of Yangtze main stream water with the Daning River water was the main driving force for the water chemistry. Contrarily, water quality was

  19. Haptic perception of wetness

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kosters, N.D.; Daanen, H.A.M.; Kappers, A.M.L.

    2011-01-01

    The sensation of wetness is well-known but barely investigated. There are no specific wetness receptors in the skin, but the sensation is mediated by temperature and pressure perception. In our study, we have measured discrimination thresholds for the haptic perception of wetness of three di erent

  20. [Metazoan parasites of Micropterus salmoides (Centrarchidae: Perciformes) from reservoirs of Nuevo León, México and their association with condition factor and gender].

    Science.gov (United States)

    Galaviz S, Lucio; Escobar G, Baldemar; Iruegas B, Francisco Javier; Molina, Zinnia Judith

    2016-06-01

    The largemouth bass Micropterus salmoides is a very valuable fish species for aquaculture and sport fishing; however, there are no systematic studies on fish metazoan parasites in Mexico. The main objective of the present study was to describe the prevalence, abundance, and intensity of M. salmoides metazoan parasites, and their association with fish condition factor and gender. The sample size was composed by 672 hosts, collected between 2011-2013 from the following reservoirs of Nuevo Leon, México: Rodrigo Gómez dam (“La Boca”, LB), Cuchillo-Solidaridad dam (CS), Salinillas lagoon (LS), Mariano Escobedo dam (“Sombreretillo”, S), and José López Portillo dam (“Cerro Prieto”, CP). Living fish were transported to the laboratory; sizes and weights were then recorded to calculate the Fulton condition factor (k). If possible, gender was also recorded. Parasites were detected under stereoscopy, recollected and preserved by traditional techniques. Statistical analysis of association between parasitic load, gender, and Fulton condition factor were calculated, using the X2 and the Student-t tests. Results showed that 12 different metazoans were identified, two flukes (Posthodiplostomum minimum centrarchi and Phyllodistomum pearsei), one tapeworm (Proteocephalus ambloplitis), three roundworms (Contracaecum sp., Spinitectus carolini and Philometra nodulosa), two acantocephalan (Neoechinorhynchus cylindratus and Arhythmorhynchus sp.), one leech (Myzobdella moorei), and three copepods (Ergasilus versicolor; Ergasilus arthrosis and Ergasilus cerastes). HSD Tukey test showed that infected fish from LB were significantly different than LS, CS, CP, and S (P<0.05). Parasites most commonly collected in all five locations were P. m. centrarchi, Contracaecum sp. and E. versicolor. The frequency of P. m. centrarchi was highly significant (P<0.001) than other parasites; furthermore, this parasite showed the highest prevalence (97.5 %), abundance (10.12-83.6), and

  1. Zn(II, Mn(II and Sr(II Behavior in a Natural Carbonate Reservoir System. Part II: Impact of Geological CO2 Storage Conditions

    Directory of Open Access Journals (Sweden)

    Auffray B.

    2016-07-01

    Full Text Available Some key points still prevent the full development of geological carbon sequestration in underground formations, especially concerning the assessment of the integrity of such storage. Indeed, the consequences of gas injection on chemistry and petrophysical properties are still much discussed in the scientific community, and are still not well known at either laboratory or field scale. In this article, the results of an experimental study about the mobilization of Trace Elements (TE during CO2 injection in a reservoir are presented. The experimental conditions range from typical storage formation conditions (90 bar, supercritical CO2 to shallower conditions (60 and 30 bar, CO2 as gas phase, and consider the dissolution of the two carbonates, coupled with the sorption of an initial concentration of 10−5 M of Zn(II, and the consequent release in solution of Mn(II and Sr(II. The investigation goes beyond the sole behavior of TE in the storage conditions: it presents the specific behavior of each element with respect to the pressure and the natural carbonate considered, showing that different equilibrium concentrations are to be expected if a fluid with a given concentration of TE leaks to an upper formation. Even though sorption is evidenced, it does not balance the amount of TE released by the dissolution process. The increase in porosity is clearly evidenced as a linear function of the CO2 pressure imposed for the St-Emilion carbonate. For the Lavoux carbonate, this trend is not confirmed by the 90 bar experiment. A preferential dissolution of the bigger family of pores from the preexisting porosity is observed in one of the samples (Lavoux carbonate while the second one (St-Emilion carbonate presents a newly-formed family of pores. Both reacted samples evidence that the pore network evolves toward a tubular network type.

  2. Ovine wet carcass syndrome of unknown aetiology

    African Journals Online (AJOL)

    A condition of unknown aetiology, known as 'the wet sheep carcass syndrome' has led to the loss of about ... aetiology. Introduction. Wet sheep carcasses were seen with increasing frequency at abattoirs from January 1981. ... the holding pens, and transport stress. In the high incidence area (see Figure 1), feeding systems.

  3. Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4-CO2-H2O) Interactions in Shale Nanopores under Reservoir Conditions. Quarterly Report.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yifeng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-10-27

    This project focuses on the systematic study of CH4-CO2-H2O interactions in shale nanopores under high-pressure and high temperature reservoir conditions. The proposed work will help to develop new stimulation strategies to enable efficient resource recovery from fewer and less environmentally impactful wells.

  4. Chalk as a reservoir

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    basin, so stylolite formation in the chalk is controlled by effective burial stress. The stylolites are zones of calcite dissolution and probably are the source of calcite for porefilling cementation which is typical in water zone chalk and also affect the reservoirs to different extent. The relatively...... 50% calcite, leaving the remaining internal surface to the fine grained silica and clay. The high specific surface of these components causes clay- and silica rich intervals to have high irreducible water saturation. Although chalks typically are found to be water wet, chalk with mixed wettability...... stabilizes chemically by recrystallization. This process requires energy and is promoted by temperature. This recrystallization in principle does not influence porosity, but only specific surface, which decreases during recrystallization, causing permeability to increase. The central North Sea is a warm...

  5. Amplitude various angles (AVA) phenomena in thin layer reservoir: Case study of various reservoirs

    International Nuclear Information System (INIS)

    thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" data-affiliation=" (Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Basic Science Center A 4thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" >Nurhandoko, Bagus Endar B.; Susilowati

    2015-01-01

    Amplitude various offset is widely used in petroleum exploration as well as in petroleum development field. Generally, phenomenon of amplitude in various angles assumes reservoir’s layer is quite thick. It also means that the wave is assumed as a very high frequency. But, in natural condition, the seismic wave is band limited and has quite low frequency. Therefore, topic about amplitude various angles in thin layer reservoir as well as low frequency assumption is important to be considered. Thin layer reservoir means the thickness of reservoir is about or less than quarter of wavelength. In this paper, I studied about the reflection phenomena in elastic wave which considering interference from thin layer reservoir and transmission wave. I applied Zoeppritz equation for modeling reflected wave of top reservoir, reflected wave of bottom reservoir, and also transmission elastic wave of reservoir. Results show that the phenomena of AVA in thin layer reservoir are frequency dependent. Thin layer reservoir causes interference between reflected wave of top reservoir and reflected wave of bottom reservoir. These phenomena are frequently neglected, however, in real practices. Even though, the impact of inattention in interference phenomena caused by thin layer in AVA may cause inaccurate reservoir characterization. The relation between classes of AVA reservoir and reservoir’s character are different when effect of ones in thin reservoir and ones in thick reservoir are compared. In this paper, I present some AVA phenomena including its cross plot in various thin reservoir types based on some rock physics data of Indonesia

  6. PREFACE: Dynamics of wetting Dynamics of wetting

    Science.gov (United States)

    Grest, Gary S.; Oshanin, Gleb; Webb, Edmund B., III

    2009-11-01

    Capillary phenomena associated with fluids wetting other condensed matter phases have drawn great scientific interest for hundreds of years; consider the recent bicentennial celebration of Thomas Young's paper on equilibrium contact angles, describing the geometric shape assumed near a three phase contact line in terms of the relevant surface energies of the constituent phases [1]. Indeed, nearly a century has passed since the seminal papers of Lucas and Washburn, describing dynamics of capillary imbibition [2, 3]. While it is generally appreciated that dynamics of fluid wetting processes are determined by the degree to which a system is out of capillary equilibrium, myriad complications exist that challenge the fundamental understanding of dynamic capillary phenomena. The topic has gathered much interest from recent Nobel laureate Pierre-Gilles de Gennes, who provided a seminal review of relevant dissipation mechanisms for fluid droplets spreading on solid surfaces [4] Although much about the dynamics of wetting has been revealed, much remains to be learned and intrinsic technological and fundamental interest in the topic drives continuing high levels of research activity. This is enabled partly by improved experimental capabilities for resolving wetting processes at increasingly finer temporal, spatial, and chemical resolution. Additionally, dynamic wetting research advances via higher fidelity computational modeling capabilities, which drive more highly refined theory development. The significance of this topic both fundamentally and technologically has resulted in a number of reviews of research activity in wetting dynamics. One recent example addresses the evaluation of existing wetting dynamics theories from an experimentalist's perspective [5]. A Current Opinion issue was recently dedicated to high temperature capillarity, including dynamics of high temperature spreading [6]. New educational tools have recently emerged for providing instruction in wetting

  7. Encapsulation technology of MR6 spent fuel and quality analysis of the EK-10 and WWR-SM spent fuel stored more than 30 years in wet conditions

    International Nuclear Information System (INIS)

    Borek-Kruszewska, E.; Bykowski, W.; Chwaszczewski, S.; Czajkowski, W.; Madry, M.

    2002-01-01

    The research reactor MARIA has been in operation for more than twenty years and all the spent fuel assemblies used since the first commissioning of the reactor are stored in wet facility on site. The present paper deals with the spent fuel MR-6 encapsulation technology in MARIA reactor. The encapsulated spent MR-6 fuel will be stored under water in the same pool unless some other solution is available. The capsules made of stainless steel are capable to accommodate one MR-6 fuel assembly. The encapsulation process is performed in the hot cell by the MARIA reactor. The spent fuel having its leg cut off is loaded to the transport cylinder manually and next transferred to a trolley. The trolley is moving to a position directly below the entrance to the hot cell and the spent fuel is entering the hot cell. The spent fuel assembly is then put into the drying cell. Dried out spent fuel is moved into the capsule mounted on the grip of the machine. Next, the capsule lid is pressed in and welded. After the leak test and filling up with helium the capsule returns from the hot cell to the pool. The hermetic capsule is sunk back into the water and positioned in the separator . The results presented earlier show, that the limiting time of WWR-SM and Ek-10 type spent fuel residence in wet storage is about 40-45 years. Therefore, the systematic quality investigation of all Ek-10 fuel elements and WWR-SM fuel assemblies discharged from EWA reactor in the period of 1959-1969 was performed. Altogether, about 2500 Ek-10 fuel elements and 47 WWR-SM fuel assemblies were investigated. The results of these investigations are presented in the present work. The sipping test, visual investigation and ultrasonic techniques were used for that purpose. The radioactive isotope Cs-137 was used as the indicator of fission product release from the fuel assembly. Taking into account the value of Cs-137 release from damaged WWR-SM fuel assembly the criteria of damaged fuel assembly were proposed. It

  8. Reservoir Simulations of Low-Temperature Geothermal Reservoirs

    Science.gov (United States)

    Bedre, Madhur Ganesh

    The eastern United States generally has lower temperature gradients than the western United States. However, West Virginia, in particular, has higher temperature gradients compared to other eastern states. A recent study at Southern Methodist University by Blackwell et al. has shown the presence of a hot spot in the eastern part of West Virginia with temperatures reaching 150°C at a depth of between 4.5 and 5 km. This thesis work examines similar reservoirs at a depth of around 5 km resembling the geology of West Virginia, USA. The temperature gradients used are in accordance with the SMU study. In order to assess the effects of geothermal reservoir conditions on the lifetime of a low-temperature geothermal system, a sensitivity analysis study was performed on following seven natural and human-controlled parameters within a geothermal reservoir: reservoir temperature, injection fluid temperature, injection flow rate, porosity, rock thermal conductivity, water loss (%) and well spacing. This sensitivity analysis is completed by using ‘One factor at a time method (OFAT)’ and ‘Plackett-Burman design’ methods. The data used for this study was obtained by carrying out the reservoir simulations using TOUGH2 simulator. The second part of this work is to create a database of thermal potential and time-dependant reservoir conditions for low-temperature geothermal reservoirs by studying a number of possible scenarios. Variations in the parameters identified in sensitivity analysis study are used to expand the scope of database. Main results include the thermal potential of reservoir, pressure and temperature profile of the reservoir over its operational life (30 years for this study), the plant capacity and required pumping power. The results of this database will help the supply curves calculations for low-temperature geothermal reservoirs in the United States, which is the long term goal of the work being done by the geothermal research group under Dr. Anderson at

  9. Changes in steam production due to the reservoir conditions in Cerro Prieto, Baja California; Cambios en la produccion de vapor debido a las condiciones del yacimiento en Cerro Prieto, Baja California

    Energy Technology Data Exchange (ETDEWEB)

    Morales Cardenas, Ramon; Rodriguez Rodriguez, Marco H. [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)]. E-mail: marco.rodriguez01@gfe.gob.mx

    2011-07-15

    In more than 35 years of exploitation, thermodynamic conditions have changed in the Cerro Prieto geothermal reservoir. The effects are analyzed of the changes to the reservoir and their consequences to steam production in different field zones. For steam production, the most important features of reservoir fluids are enthalpies and pressures. The evolution of these features is presented in an enthalpy-pressure diagram. Here it can be seen that some reservoir zones have almost reached abandonment conditions. [Spanish] En mas de 35 anos de explotacion el yacimiento geotermico de Cerro Prieto ha experimentado cambios en sus condiciones termodinamicas. En este trabajo se analiza el efecto de esos cambios del yacimiento y su repercusion en la produccion de vapor para las diferentes zonas en las que se ha dividido el campo. Las propiedades mas importantes del fluido en el yacimiento para la produccion de vapor son su entalpia y su presion, por lo que se presenta la evolucion de esas propiedades en un diagrama de presion-entalpia, en el que se observa que hay zonas del yacimiento que estan proximas a alcanzar condiciones de abandono.

  10. Dynamic reservoir-condition microtomography of reactive transport in complex carbonates: Effect of initial pore structure and initial brine pH

    Science.gov (United States)

    Menke, H. P.; Bijeljic, B.; Blunt, M. J.

    2017-05-01

    We study the impact of brine acidity and initial pore structure on the dynamics of fluid/solid reaction at high Péclet numbers and low Damköhler numbers. A laboratory μ-CT scanner was used to image the dissolution of Ketton, Estaillades, and Portland limestones in the presence of CO2-acidified brine at reservoir conditions (10 MPa and 50 °C) at two injected acid strengths for a period of 4 h. Each sample was scanned between 6 and 10 times at ∼4 μm resolution and multiple effluent samples were extracted. The images were used as inputs into flow simulations, and analysed for dynamic changes in porosity, permeability, and reaction rate. Additionally, the effluent samples were used to verify the image-measured porosity changes. We find that initial brine acidity and pore structure determine the type of dissolution. Dissolution is either uniform where the porosity increases evenly both spatially and temporally, or occurs as channelling where the porosity increase is concentrated in preferential flow paths. Ketton, which has a relatively homogeneous pore structure, dissolved uniformly at pH = 3.6 but showed more channelized flow at pH = 3.1. In Estaillades and Portland, increasingly complex carbonates, channelized flow was observed at both acidities with the channel forming faster at lower pH. It was found that the effluent pH, which is higher than that injected, is a reasonably good indicator of effective reaction rate during uniform dissolution, but a poor indicator during channelling. The overall effective reaction rate was up to 18 times lower than the batch reaction rate measured on a flat surface at the effluent pH, with the lowest reaction rates in the samples with the most channelized flow, confirming that transport limitations are the dominant mechanism in determining reaction dynamics at the fluid/solid boundary.

  11. Understanding and Mitigating Reservoir Compaction: an Experimental Study on Sand Aggregates

    Science.gov (United States)

    Schimmel, M.; Hangx, S.; Spiers, C. J.

    2016-12-01

    Fossil fuels continue to provide a source for energy, fuels for transport and chemicals for everyday items. However, adverse effects of decades of hydrocarbons production are increasingly impacting society and the environment. Production-driven reduction in reservoir pore pressure leads to a poro-elastic response of the reservoir, and in many occasions to time-dependent compaction (creep) of the reservoir. In turn, reservoir compaction may lead to surface subsidence and could potentially result in induced (micro)seismicity. To predict and mitigate the impact of fluid extraction, we need to understand production-driven reservoir compaction in highly porous siliciclastic rocks and explore potential mitigation strategies, for example, by using compaction-inhibiting injection fluids. As a first step, we investigate the effect of chemical environment on the compaction behaviour of sand aggregates, comparable to poorly consolidated, highly porous sandstones. The sand samples consist of loose aggregates of Beaujean quartz sand, sieved into a grainsize fraction of 180-212 µm. Uniaxial compaction experiments are performed at an axial stress of 35 MPa and temperature of 80°C, mimicking conditions of reservoirs buried at three kilometres depth. The chemical environment during creep is either vacuum-dry or CO2-dry, or fluid-saturated, with fluids consisting of distilled water, acid solution (CO2-saturated water), alkaline solution (pH 9), aluminium solution (pH 3) and solution with surfactants (i.e., AMP). Preliminary results show that compaction of quartz sand aggregates is promoted in a wet environment compared to a dry environment. It is inferred that deformation is controlled by subcritical crack growth when dry and stress corrosion cracking when wet, both resulting in grain failure and subsequent grain rearrangement. Fluids inhibiting these processes, have the potential to inhibit aggregate compaction.

  12. Long term wet spent nuclear fuel storage

    International Nuclear Information System (INIS)

    1987-04-01

    The meeting showed that there is continuing confidence in the use of wet storage for spent nuclear fuel and that long-term wet storage of fuel clad in zirconium alloys can be readily achieved. The importance of maintaining good water chemistry has been identified. The long-term wet storage behaviour of sensitized stainless steel clad fuel involves, as yet, some uncertainties. However, great reliance will be placed on long-term wet storage of spent fuel into the future. The following topics were treated to some extent: Oxidation of the external surface of fuel clad, rod consolidation, radiation protection, optimum methods of treating spent fuel storage water, physical radiation effects, and the behaviour of spent fuel assemblies of long-term wet storage conditions. A number of papers on national experience are included

  13. Incorporating teleconnection information into reservoir operating policies using Stochastic Dynamic Programming and a Hidden Markov Model

    Science.gov (United States)

    Turner, Sean; Galelli, Stefano; Wilcox, Karen

    2015-04-01

    Water reservoir systems are often affected by recurring large-scale ocean-atmospheric anomalies, known as teleconnections, that cause prolonged periods of climatological drought. Accurate forecasts of these events -- at lead times in the order of weeks and months -- may enable reservoir operators to take more effective release decisions to improve the performance of their systems. In practice this might mean a more reliable water supply system, a more profitable hydropower plant or a more sustainable environmental release policy. To this end, climate indices, which represent the oscillation of the ocean-atmospheric system, might be gainfully employed within reservoir operating models that adapt the reservoir operation as a function of the climate condition. This study develops a Stochastic Dynamic Programming (SDP) approach that can incorporate climate indices using a Hidden Markov Model. The model simulates the climatic regime as a hidden state following a Markov chain, with the state transitions driven by variation in climatic indices, such as the Southern Oscillation Index. Time series analysis of recorded streamflow data reveals the parameters of separate autoregressive models that describe the inflow to the reservoir under three representative climate states ("normal", "wet", "dry"). These models then define inflow transition probabilities for use in a classic SDP approach. The key advantage of the Hidden Markov Model is that it allows conditioning the operating policy not only on the reservoir storage and the antecedent inflow, but also on the climate condition, thus potentially allowing adaptability to a broader range of climate conditions. In practice, the reservoir operator would effect a water release tailored to a specific climate state based on available teleconnection data and forecasts. The approach is demonstrated on the operation of a realistic, stylised water reservoir with carry-over capacity in South-East Australia. Here teleconnections relating

  14. TRITIUM RESERVOIR STRUCTURAL PERFORMANCE PREDICTION

    Energy Technology Data Exchange (ETDEWEB)

    Lam, P.S.; Morgan, M.J

    2005-11-10

    The burst test is used to assess the material performance of tritium reservoirs in the surveillance program in which reservoirs have been in service for extended periods of time. A materials system model and finite element procedure were developed under a Savannah River Site Plant-Directed Research and Development (PDRD) program to predict the structural response under a full range of loading and aged material conditions of the reservoir. The results show that the predicted burst pressure and volume ductility are in good agreement with the actual burst test results for the unexposed units. The material tensile properties used in the calculations were obtained from a curved tensile specimen harvested from a companion reservoir by Electric Discharge Machining (EDM). In the absence of exposed and aged material tensile data, literature data were used for demonstrating the methodology in terms of the helium-3 concentration in the metal and the depth of penetration in the reservoir sidewall. It can be shown that the volume ductility decreases significantly with the presence of tritium and its decay product, helium-3, in the metal, as was observed in the laboratory-controlled burst tests. The model and analytical procedure provides a predictive tool for reservoir structural integrity under aging conditions. It is recommended that benchmark tests and analysis for aged materials be performed. The methodology can be augmented to predict performance for reservoir with flaws.

  15. Challenges of reservoir properties and production history matching in a CHOPS reservoir study

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Mahbub [Department of Geoscience, University of Calgary (Canada)

    2011-07-01

    In order to meet increasing world energy demand, wells have to be drilled within very thin reservoir beds. This paper, we present one of the solutions for optimizing the reservoir characterization. Reservoir characterization is the process between the discovery of a property and the reservoir management phase. Principal data for reservoir modeling are: 4D Seismic interpretation, wireline log interpretation, core analysis, and petrophysical analysis. Reservoir conditions, perforation and completion technology are the key issues to the production rate of cold production. Reservoir modeling intends to minimize the risk factor, maximize production, and help determine the location for infill drillings. Cold heavy oil production with sand (CHOPS) is a method for enhancing primary production from heavy oil reservoirs. Gravitational forces, natural fluid pressure gradients and foamy oil flow phenomena are the major driving forces of the CHOPS mechanism. Finally, Reservoir characterization allows better understanding of permeability and porosity prediction.

  16. The behaviour of an old catalyst revisited in a wet environment: Co ions in APO-5 split water under mild conditions.

    Science.gov (United States)

    Bonelli, Barbara; Armandi, Marco; Hernandez, Simelys; Vankova, Svetoslava; Celasco, Edvige; Tomatis, Maura; Saracco, Guido; Garrone, Edoardo

    2014-04-21

    Samples of the activated microporous aluminophosphate Co-APO-5, featuring ca. 20% of Co(3+) cations, when immersed in water evolve molecular oxygen at room temperature in an endothermic process, without the need for either light or a sacrificial reactant. Successive drying of the sample at temperatures around 520 K releases molecular hydrogen, with recovery of the initial conditions. Several hydration-dehydration cycles may be performed without loss of activity, i.e. water is split in a thermal cycle under relatively mild conditions.

  17. Chickamauga reservoir embayment study - 1990

    Energy Technology Data Exchange (ETDEWEB)

    Meinert, D.L.; Butkus, S.R.; McDonough, T.A.

    1992-12-01

    The objectives of this report are three-fold: (1) assess physical, chemical, and biological conditions in the major embayments of Chickamauga Reservoir; (2) compare water quality and biological conditions of embayments with main river locations; and (3) identify any water quality concerns in the study embayments that may warrant further investigation and/or management actions. Embayments are important areas of reservoirs to be considered when assessments are made to support water quality management plans. In general, embayments, because of their smaller size (water surface areas usually less than 1000 acres), shallower morphometry (average depth usually less than 10 feet), and longer detention times (frequently a month or more), exhibit more extreme responses to pollutant loadings and changes in land use than the main river region of the reservoir. Consequently, embayments are often at greater risk of water quality impairments (e.g. nutrient enrichment, filling and siltation, excessive growths of aquatic plants, algal blooms, low dissolved oxygen concentrations, bacteriological contamination, etc.). Much of the secondary beneficial use of reservoirs occurs in embayments (viz. marinas, recreation areas, parks and beaches, residential development, etc.). Typically embayments comprise less than 20 percent of the surface area of a reservoir, but they often receive 50 percent or more of the water-oriented recreational use of the reservoir. This intensive recreational use creates a potential for adverse use impacts if poor water quality and aquatic conditions exist in an embayment.

  18. Evaluatie Wet openbare manifestaties

    NARCIS (Netherlands)

    Roorda, Berend; Brouwer, Jan; Schilder, A.E.

    2015-01-01

    Het rapport betreft een uitgebreide evaluatie van de Wet openbare manifestaties (Wom) in opdracht van het Ministerie van Binnenlandse Zaken en Koninkrijksrelaties. Op grond van onderzoek naar de parlementaire geschiedenis van de Wom, de literatuur, de jurisprudentie, gesprekken met beleidsadviseurs

  19. Enuresis (Bed-Wetting)

    Science.gov (United States)

    ... Symptoms of enuresis Enuresis is when an older child (age 7 or older) wets the bed at night ... feel guilt and embarrassment. It’s true that your child should take responsibility for bedwetting. He or she could do this ...

  20. Helminths in rodents from Wet Markets in Thailand

    Directory of Open Access Journals (Sweden)

    Ribas A.

    2016-12-01

    Full Text Available Only a few surveys have ever been carried out of the helminths of the commensal rodents found in the traditional wet markets that play such an important part of daily life in South-east Asia. The potential of rodents as reservoirs of zoonoses including helminths is of great interest since in these markets humans and rodents come into closer contact than in other environments and food may be indirectly contaminated via rodent faeces. Helminths in a total of 98 rats belonging to two species (Rattus norvegicus and Rattus exulans were surveyed in eight traditional wet markets in Udon Thani, Thailand. Thirteen species of helminths were recovered, seven of which are potentially zoo-notic, with an overall prevalence of 89.8 %. Our results show that rodents in wet markets could pose a threat to human health as potential reservoirs of zoonotic helminthiases.

  1. Avoided critical behavior in dynamically forced wetting.

    Science.gov (United States)

    Snoeijer, Jacco H; Delon, Giles; Fermigier, Marc; Andreotti, Bruno

    2006-05-05

    A solid object can be coated by a nonwetting liquid since a receding contact line cannot exceed a critical speed. In this Letter we study the dynamical wetting transition at which a liquid film gets deposited by withdrawing a vertical plate out of a liquid reservoir. It has recently been predicted that this wetting transition is critical with diverging time scales and coincides with the disappearance of stationary menisci. We demonstrate experimentally and theoretically that the transition is due to the formation of a solitary wave, well below the critical point. As a consequence, relaxation times remain finite at threshold. The structure of the liquid deposited on the plate involves a capillary ridge that does not trivially match the Landau-Levich film.

  2. Leaf wetness distribution within a potato crop

    Science.gov (United States)

    Heusinkveld, B. G.

    2010-07-01

    The Netherlands has a mild maritime climate and therefore the major interest in leaf wetness is associated with foliar plant diseases. During moist micrometeorological conditions (i.e. dew, fog, rain), foliar fungal diseases may develop quickly and thereby destroy a crop quickly. Potato crop monocultures covering several hectares are especially vulnerable to such diseases. Therefore understanding and predicting leaf wetness in potato crops is crucial in crop disease control strategies. A field experiment was carried out in a large homogeneous potato crop in the Netherlands during the growing season of 2008. Two innovative sensor networks were installed as a 3 by 3 grid at 3 heights covering an area of about 2 hectares within two larger potato crops. One crop was located on a sandy soil and one crop on a sandy peat soil. In most cases leaf wetting starts in the top layer and then progresses downward. Leaf drying takes place in the same order after sunrise. A canopy dew simulation model was applied to simulate spatial leaf wetness distribution. The dew model is based on an energy balance model. The model can be run using information on the above-canopy wind speed, air temperature, humidity, net radiation and within canopy air temperature, humidity and soil moisture content and temperature conditions. Rainfall was accounted for by applying an interception model. The results of the dew model agreed well with the leaf wetness sensors if all local conditions were considered. The measurements show that the spatial correlation of leaf wetness decreases downward.

  3. Oil/water displacement in microfluidic packed beds under weakly water-wetting conditions: competition between precursor film flow and piston-like displacement

    Science.gov (United States)

    Tanino, Yukie; Zacarias-Hernandez, Xanat; Christensen, Magali

    2018-02-01

    Optical microscopy was used to measure depth-averaged oil distribution in a quasi-monolayer of crushed marble packed in a microfluidic channel as it was displaced by water. By calibrating the transmitted light intensity to oil thickness, we account for depth variation in the fluid distribution. Experiments reveal that oil saturation at water breakthrough decreases with increasing Darcy velocity, U_{ {w}}, between capillary numbers {Ca} = μ _{ {w}} U_{ {w}}/σ = 9× 10^{-7} and 9× 10^{-6}, where μ _{ {w}} is the dynamic viscosity of water and σ is the oil/water interfacial tension, under the conditions considered presently. In contrast, end-point (long-time) remaining oil saturation depends only weakly on U_{ {w}}. This transient dependence on velocity is attributed to the competition between precursor film flow, which controls early time invasion dynamics but is inefficient at displacing oil, and piston-like displacement, which controls ultimate oil recovery. These results demonstrate that microfluidic experiments using translucent grains and fluids are a convenient tool for quantitative investigation of sub-resolution liquid/liquid displacement in porous media.

  4. Development of a 'wet' variant of electron beam gas treatment technology adapted to economic and technological conditions of developing countries to remove NOx, SO2 and particulates from flue gas and produce fertilizers

    International Nuclear Information System (INIS)

    Fainchtein, O.L.; Piotrovskiy, V.V.; Savenkov, A.S.; Smirnov, I.K.; Salimov, R.A.

    1998-01-01

    The Institute Energostal with its co-authors has carried out real gas tests of the EB flue gas treatment technology at a 1000 m 3 /h experimental installation at Lipetsk Metallurgical Plant (Lipetsk, Russia), including agricultural tests to utilize the by-product. On the basis of the results obtained, a ''wet'' variant of the EB technology has been developed. A conceptual, basic and working design was engineered for a 100,000 m 3 /h EB demonstration unit at Slavyanskaya Power Plant (Donbass, Ukraine). In a ''wet'' variant of the technology, the following problems are believed to be harmoniously solved: reduction of power consumption for irradiation due to heterogenous reactions based on the so-called droplet mechanism, efficiency and reliability of collecting ammonia salts by wet dust catchers, wet granulation of the by-product using traditional equipment. A ''wet'' variant of the EB technology has a low capital cost and requires less floor area. Therefore, despite all its disadvantages typical for any wet method of gas purification, the ''wet'' EB technology can find its application in developing countries with low levels of economy. In many countries of this type, in particular, in the countries of the former Soviet Union, wet methods of gas treatment and fertilizer granulation are still widely used. As a matter of fact, it is a conventionally ''wet'' method (hence the inverted commas), since no waste water is discharged into the environment

  5. Vicissitudes of oxidative stress biomarkers in the estuarine crab Scylla serrata with reference to dry and wet weather conditions in Ennore estuary, Tamil Nadu, India.

    Science.gov (United States)

    Ragunathan, M G

    2017-03-15

    The primary objective of this study was to understand the impact of monsoon and summer seasons on the Polychlorinated Biphenyls (PCB's) and petroleum hydrocarbon compounds (PHC's) load in Ennore estuary and how the physiological response of estuarine Scylla serrata inhabiting in this estuary changed with reference to antioxidant defense. Seasonal levels of PCB's and PHC's were assessed in the water along with their bioaccumulation in gills, hemolymph, hepatopancreas and ovary of S. serrata. Concentration of PCB's and PHC's in water and their bioaccumulation was found to be higher in summer season when compared to monsoon season. Enzymic antioxidant assays [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione-S-transferase (GST)]; non-enzymic antioxidant assays [glutathione (GSH), vitamin C, vitamin E] and macromolecular alterations [membrane lipid peroxidation (LPO), and DNA Damage (strand breaks)] were assessed in the gills, hemolymph and hepatopancreas of S. serrata. There was a significant (p<0.05) upregulation in lipid peroxidation activity and DNA damage activity collected during the summer season when compared to the pre- and post-monsoon seasons. On the contrary, the enzymic and non-enzymic antioxidants exhibited significant (p<0.05) down regulation in the gills, hemolymph, hepatopancreas and ovary of S. serrata. Oxidative stress biomarkers represented a significant (p<0.05) maximum in gills when compared to hemolymph and hepatopancreas of S. serrata. Present study provided scientific evidences of how the antioxidant defense status of S. serrata responded to PCB's and PAH's stress with reference to seasonal vicissitudes, which indirectly represented the environmental health conditions of the estuary. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Influence of the reheat temperature on the efficiency of the wet-steam turbines of thermal power plants that operate under variable conditions

    Science.gov (United States)

    Tarelin, A. A.

    2017-04-01

    A brief analysis of the existing methods for controlling the operating conditions of the turbine units that operate at variable loads is presented. In practice, the outdated rule of operation is most frequently used that states that the higher the parameters of the live and reheat steam and the lower the condenser pressure are, the higher is the efficiency of the turbine unit. However, in the technical literature, there is sufficiently substantiated evidence that this approach is not always correct, especially under low loads. This applies to both the regulation of the initial and final pressure and reheat temperature t r. In the article, particular stress is laid on the controllable parameter t r, the effect of which in the operational practices, according to the results of the analysis, is underestimated. The causes are considered that constrain more effective use of reheat temperature t r as a process variable. The results of field trials to investigate the influence of t r on the efficiency of turbine units of various capacities, viz., of 210, 250, 300, and 325 MW, during operation at varying loads are presented. It is shown that a decrease in t r to an optimal value of 10-30°C, depending on the load and the condenser pressure, increases the thermal efficiency by 1-2%. The following general pattern has been set: the lower the load, the lower the optimal reheat temperature. The main causes and factors that result in more efficient use of the heat phase transition in the steam path of the low-pressure cylinder and increased efficiency of the unit under rational choice of the reheat temperature are studied.

  7. How to determine wet-snow instability

    Science.gov (United States)

    Reiweger, Ingrid; Mitterer, Christoph

    2017-04-01

    Processes leading to wet-snow instability are very complex and highly non-linear in time and space. Infiltrating water changes wet-snow strength and other mechanical properties. A high liquid water content presumably favors fracture propagation, which consequently has an influence on the formation of wet slab avalanches. The weakening of snow due to liquid water within the snowpack might be gradual (melt event) or sudden (rain-on-snow event). There are several feedback mechanisms between liquid water and snow stratigraphy, making the weakening process complex. We used modelled stability indices to determine periods with high wet-snow instability. These indices were either based on energy and mass balances indicating critical amounts of water within the snowpack or on simple hydro-mechanical relationships. In addition to the modelled indices, preliminary field studies investigated the fracture initiation and fracture propagation propensity within wet snowpacks. We therefore performed Rutschblock and propagation saw tests in faceted weak layers with different volumetric liquid water contents. Results of simulations and field experiments showed that a critical amount of liquid water combined with a pre-critical snow stratigraphy were relevant for wet-snow instability. The critical amount of water was assumed to drive both failure initiation and fracture propagation. The simulated indices and observed stability tests indicated a high wet-snow instability when the volumetric liquid water content within faceted weak layers exceeded 3. Within our propagation saw test measurements crack propagation propensity even slightly decreased at very low liquid water contents compared to completely dry conditions, presumably due to capillary forces. For liquid water contents higher than 3-4%, however, crack propagation propensity strongly increased, which we assume was due to the weakening of bonds between grains within the increasingly wet weak snow layer. Our results could be used

  8. Wet storage integrity update

    International Nuclear Information System (INIS)

    Bailey, W.J.; Johnson, A.B. Jr.

    1983-09-01

    This report includes information from various studies performed under the Wet Storage Task of the Spent Fuel Integrity Project of the Commercial Spent Fuel Management (CSFM) Program at Pacific Northwest Laboratory. An overview of recent developments in the technology of wet storage of spent water reactor fuel is presented. Licensee Event Reports pertaining to spent fuel pools and the associated performance of spent fuel and storage components during wet storage are discussed. The current status of fuel that was examined under the CSFM Program is described. Assessments of the effect of boric acid in spent fuel pool water on the corrosion and stress corrosion cracking of stainless steel and the stress corrosion cracking of stainless steel piping containing stagnant water at spent fuel pools are discussed. A list of pertinent publications is included. 84 references, 21 figures, 11 tables

  9. Advanced reservoir characterization and evaluation of CO2 gravity drainage in the naturally fractured Spraberry Trend Area. Annual report, September 1, 1996--August 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, P.

    1998-06-01

    The objective of the Spraberry CO{sub 2} pilot project is to determine the technical and economic feasibility of continuous CO{sub 2} injection in the naturally fractured reservoirs of the Spraberry Trend. In order to describe, understand, and model CO{sub 2} flooding in the naturally fractured Spraberry reservoirs, characterization of the fracture system is a must. Additional reservoir characterization was based on horizontal coring in the second year of the project. In addition to characterization of natural fractures, horizontal coring has confirmed a previously developed rock model for describing the Spraberry Trend shaly sands. A better method for identifying Spraberry pay zones has been verified. The authors have completed the reservoir characterization, which includes matrix description and detection (from core-log integration) and fracture characterization. This information is found in Section 1. The authors have completed extensive imbibition experiments that strongly indicate that the weakly water-wet behavior of the reservoir rock may be responsible for poor waterflood response observed in many Spraberry fields. The authors have also made significant progress in analytical and numerical simulation of performance in Spraberry reservoirs as seen in Section 3. They have completed several suites of CO{sub 2} gravity drainage in Spraberry and Berea whole cores at reservoir conditions and reported in Section 4. The results of these experiments have been useful in developing a model for free-fall gravity drainage and have validated the premise that CO{sub 2} will recover oil from tight, unconfined Spraberry matrix.

  10. Differences in the heat stress associated with white sportswear and being semi-nude in exercising humans under conditions of radiant heat and wind at a wet bulb globe temperature of greater than 28 °C.

    Science.gov (United States)

    Tsuji, Michio; Kume, Masashi; Tuneoka, Hideyuki; Yoshida, Tetsuya

    2014-08-01

    This study investigated whether wearing common white sportswear can reduce heat stress more than being semi-nude during exercise of different intensities performed under radiant heat and wind conditions, such as a hot summer day. After a 20-min rest period, eight male subjects performed three 20 min sessions of cycling exercise at a load intensity of 20 % or 50 % of their peak oxygen uptake (VO2peak) in a room maintained at a wet bulb globe temperature (WBGT) of 28.7 ± 0.1 °C using two spot lights and a fan (0.8 m/s airflow). Subjects wore common white sportswear (WS) consisting of a long-sleeved shirt (45 % cotton and 55 % polyester) and short pants (100 % polyester), or only swimming pants (SP) under the semi-nude condition. The mean skin temperature (Tsk) was greater when subjects wore SP than WS under both the 20 % and 50 % exercise conditions. During the 50 % exercise, the rating of perceived exertion (RPE) and thermal sensation (TS), and the increases in esophageal temperature (ΔTes) and heart rate were significantly higher (Pheat storage (S), calculated from the changes in the mean body temperature (0.9Tes + 0.1 Tsk), was significantly lower in the WS trials than in the SP trials during the 20 min resting period before exercise session. However, S was similar between conditions during the 20 % exercise, but was greater in the WS than in the SP trials during 50 % exercise. These results suggest that, under conditions of radiant heat and wind at a WBGT greater than 28 °C, the heat stress associated with wearing common WS is similar to that of being semi-nude during light exercise, but was greater during moderate exercise, and the storage of body heat can be reduced by wearing WS during rest periods.

  11. Fractured Petroleum Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Firoozabadi, Dr. Abbas

    2000-01-18

    In this report the results of experiments of water injection in fractured porous media comprising a number of water-wet matrix blocks are reported for the first time. The blocks experience an advancing fracture-water level (FWL). Immersion-type experiments are performed for comparison; the dominant recovery mechanism changed from co-current to counter-current imbibition when the boundary conditions changed from advancing FWL to immersion-type. Single block experiments of co-current and counter-current imbibition was performed and co-current imbibition leads to more efficient recovery was found.

  12. Minimal thermodynamic conditions in the reservoir to produce steam at the Cerro Prieto geothermal field, BC; Condiciones termodinamicas minimas del yacimiento para producir vapor en el campo geotermico de Cerro Prieto, B.C.

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rodriguez; Marco Helio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx

    2009-01-15

    Minimal thermodynamic conditions in the Cerro Prieto geothermal reservoir for steam production are defined, taking into account the minimal acceptable steam production at the surface, considering a rank of mixed-enthalpies for different well-depths, and allowing proper assessments for the impacts of the changes in fluid reservoir pressure and enthalpy. Factors able to influence steam production are discussed. They have to be considered when deciding whether or not to drill or repair a well in a particular area of the reservoir. These evaluations become much more relevant by considering the huge thermodynamic changes that have occurred at the Cerro Prieto geothermal reservoir from its development, starting in 1973, which has lead to abandoning some steam producing areas in the field. [Spanish] Las condiciones termodinamicas minimas del yacimiento geotermico de Cerro Prieto, BC, para producir vapor se determinan tomando en cuenta la minima produccion de vapor aceptable en superficie, considerando un rango de entalpias de la mezcla y para diferentes profundidades de pozos, lo que permite valorar adecuadamente el impacto de la evolucion de la presion y entalpia del fluido en el yacimiento. Se discuten los factores que pueden afectar la produccion de vapor, los cuales se deben tomar en cuenta para determinar la conveniencia o no de perforar o reparar un pozo en determinada zona del yacimiento. Estas evaluaciones adquieren gran relevancia al considerar los enormes cambios termodinamicos que ha presentado el yacimiento geotermico de Cerro Prieto, como resultado de su explotacion iniciada en 1973, lo que ha llevado a abandonar algunas zonas del campo para la produccion de vapor. Palabras Clave: Cerro Prieto, entalpia, evaluacion de yacimientos, politicas de explotacion, presion, produccion de vapor.

  13. The 12.4 ka Upper Apoyeque Tephra, Nicaragua: stratigraphy, dispersal, composition, magma reservoir conditions and trigger of the plinian eruption

    Science.gov (United States)

    Wehrmann, Heidi; Freundt, Armin; Kutterolf, Steffen

    2016-06-01

    Upper Apoyeque Tephra (UAq) was formed by a rhyodacitic plinian eruption in west-central Nicaragua at 12.4 ka BP. The fallout tephra was dispersed from a progressively rising plinian eruption column that became exposed to different wind speeds and directions at different heights in the stratosphere, leading to an asymmetric tephra fan with different facies in the western and southern sector. Tephra dispersal data integrated with geochemical compositions of lava flows in the area facilitate delimitation of the source vent to the south of Chiltepe Peninsula. UAq, Lower Apoyeque Tephra, Apoyeque Ignimbrite, and two lava lithic clasts in San Isidro Tephra together form a differentiation trend distinct from that of the younger tephras and lavas at Chiltepe Volcanic Complex in a TiO2 versus K2O diagram, compositionally precluding a genetic relationship of UAq with the present-day Apoyeque stratovolcano. Apoyeque Volcano in its present shape did not exist at the time of the UAq eruption. The surface expression of the UAq vent is now obscured by younger eruption products and lake water. Pressure-temperature constraints based on mineral-melt equilibria and fluid inclusions in plagioclase indicate at least two magma storage levels. Clinopyroxenes crystallised in a deep crustal reservoir at ˜24 km depth as inferred from clinopyroxene-melt inclusion pairs. Chemical disequilibrium between clinopyroxenes and matrix glasses indicates rapid magma ascent to the shallower reservoir at ˜5.4 km depth, where magnesiohornblendes and plagioclase fractionated at a temperature of ˜830 °C. Water concentrations were ˜5.5 wt.% as derived from congruent results of amphibole and plagioclase-melt hygrometry. The eruption was triggered by injection of a hotter, more primitive melt into a water-supersaturated reservoir.

  14. Development of gas and gas condensate reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    In the study of gas reservoir development, the first year topics are restricted on reservoir characterization. There are two types of reservoir characterization. One is the reservoir formation characterization and the other is the reservoir fluid characterization. For the reservoir formation characterization, calculation of conditional simulation was compared with that of unconditional simulation. The results of conditional simulation has higher confidence level than the unconditional simulation because conditional simulation considers the sample location as well as distance correlation. In the reservoir fluid characterization, phase behavior calculations revealed that the component grouping is more important than the increase of number of components. From the liquid volume fraction with pressure drop, the phase behavior of reservoir fluid can be estimated. The calculation results of fluid recombination, constant composition expansion, and constant volume depletion are matched very well with the experimental data. In swelling test of the reservoir fluid with lean gas, the accuracy of dew point pressure forecast depends on the component characterization. (author). 28 figs., 10 tabs.

  15. Remotely Sensed Based Lake/Reservoir Routing in Congo River Basin

    Science.gov (United States)

    Raoufi, R.; Beighley, E.; Lee, H.

    2017-12-01

    Lake and reservoir dynamics can influence local to regional water cycles but are often not well represented in hydrologic models. One challenge that limits their inclusion in models is the need for detailed storage-discharge behavior that can be further complicated in reservoirs where specific operation rules are employed. Here, the Hillslope River Routing (HRR) model is combined with a remotely sensed based Reservoir Routing (RR) method and applied to the Congo River Basin. Given that topographic data are often continuous over the entire terrestrial surface (i.e., does not differentiate between land and open water), the HRR-RR model integrates topographic derived river networks and catchment boundaries (e.g., HydroSHEDs) with water boundary extents (e.g., Global Lakes and Wetlands Database) to develop the computational framework. The catchments bordering lakes and reservoirs are partitioned into water and land portions, where representative flowpath characteristics are determined and vertical water balance and lateral routings is performed separately on each partition based on applicable process models (e.g., open water evaporation vs. evapotranspiration). To enable reservoir routing, remotely sensed water surface elevations and extents are combined to determine the storage change time series. Based on the available time series, representative storage change patterns are determined. Lake/reservoir routing is performed by combining inflows from the HRR-RR model and the representative storage change patterns to determine outflows. In this study, a suite of storage change patterns derived from remotely sensed measurements are determined representative patterns for wet, dry and average conditions. The HRR-RR model dynamically selects and uses the optimal storage change pattern for the routing process based on these hydrologic conditions. The HRR-RR model results are presented to highlight the importance of lake attenuation/routing in the Congo Basin.

  16. Wetting of real surfaces

    CERN Document Server

    Bormashenko, Edward Yu

    2013-01-01

    The problem of wetting and drop dynamics on various surfaces is very interesting from both the scientificas well as thepractical viewpoint, and subject of intense research.The results are scattered across papers in journals, sothis workwill meet the need for a unifying, comprehensive work.

  17. WetVegEurope

    NARCIS (Netherlands)

    Landucci, Flavia; Řezníčková, Marcela; Šumberová, Kateřina; Hennekens, S.M.; Schaminée, J.H.J.

    2015-01-01

    WetVegEurope is a research project (http://www.sci.muni.cz/botany/vegsci/wetveg) whose goal is to provide a synthesized formalized classification of the aquatic and marsh vegetation across Europe at the level of phytosociological associations. In order to achieve the project objective, a

  18. Characterization of Cold-Wet Conditions

    Science.gov (United States)

    1988-06-01

    0a000. 30 Precpltation 20’- •O0 SOL 1 01 to 00 -,s -to -5 0 5 Temperature (Deg.C.) Fro.m1 LiquidO Time (X) 40 000 o0 N Prelpitatlm 0 0 * 0 0 II to 0 -15...classification of Title. Abstract, Keywords) DOCUMENT CONTROL DATA (Security classification of title, body of abstract and indexing ennotition must be

  19. Understanding the True Stimulated Reservoir Volume in Shale Reservoirs

    KAUST Repository

    Hussain, Maaruf

    2017-06-06

    Successful exploitation of shale reservoirs largely depends on the effectiveness of hydraulic fracturing stimulation program. Favorable results have been attributed to intersection and reactivation of pre-existing fractures by hydraulically-induced fractures that connect the wellbore to a larger fracture surface area within the reservoir rock volume. Thus, accurate estimation of the stimulated reservoir volume (SRV) becomes critical for the reservoir performance simulation and production analysis. Micro-seismic events (MS) have been commonly used as a proxy to map out the SRV geometry, which could be erroneous because not all MS events are related to hydraulic fracture propagation. The case studies discussed here utilized a fully 3-D simulation approach to estimate the SRV. The simulation approach presented in this paper takes into account the real-time changes in the reservoir\\'s geomechanics as a function of fluid pressures. It is consisted of four separate coupled modules: geomechanics, hydrodynamics, a geomechanical joint model for interfacial resolution, and an adaptive re-meshing. Reservoir stress condition, rock mechanical properties, and injected fluid pressure dictate how fracture elements could open or slide. Critical stress intensity factor was used as a fracture criterion governing the generation of new fractures or propagation of existing fractures and their directions. Our simulations were run on a Cray XC-40 HPC system. The studies outcomes proved the approach of using MS data as a proxy for SRV to be significantly flawed. Many of the observed stimulated natural fractures are stress related and very few that are closer to the injection field are connected. The situation is worsened in a highly laminated shale reservoir as the hydraulic fracture propagation is significantly hampered. High contrast in the in-situ stresses related strike-slip developed thereby shortens the extent of SRV. However, far field nature fractures that were not connected to

  20. Fundamentals of Reservoir Surface Energy as Related to Surface Properties, Wettability, Capillary Action, and Oil Recovery from Fractured Reservoirs by Spontaneous Imbibition

    Energy Technology Data Exchange (ETDEWEB)

    Norman Morrow; Herbert Fischer; Yu Li; Geoffrey Mason; Douglas Ruth; Siddhartha Seth; Zhengxin Tong; Evren Unsal; Siluni Wickramathilaka; Shaochang Wo; Peigui Yin

    2008-06-30

    The objective of this project is to increase oil recovery from fractured reservoirs through improved fundamental understanding of the process of spontaneous imbibition by which oil is displaced from the rock matrix into the fractures. Spontaneous imbibition is fundamentally dependent on the reservoir surface free energy but this has never been investigated for rocks. In this project, the surface free energy of rocks will be determined by using liquids that can be solidified within the rock pore space at selected saturations. Thin sections of the rock then provide a two-dimensional view of the rock minerals and the occupant phases. Saturations and oil/rock, water/rock, and oil/water surface areas will be determined by advanced petrographic analysis and the surface free energy which drives spontaneous imbibition will be determined as a function of increase in wetting phase saturation. The inherent loss in surface free energy resulting from capillary instabilities at the microscopic (pore level) scale will be distinguished from the decrease in surface free energy that drives spontaneous imbibition. A mathematical network/numerical model will be developed and tested against experimental results of recovery versus time over broad variation of key factors such as rock properties, fluid phase viscosities, sample size, shape and boundary conditions. Two fundamentally important, but not previously considered, parameters of spontaneous imbibition, the capillary pressure acting to oppose production of oil at the outflow face and the pressure in the non-wetting phase at the no-flow boundary versus time, will also be measured and modeled. Simulation and network models will also be tested against special case solutions provided by analytic models. In the second stage of the project, application of the fundamental concepts developed in the first stage of the project will be demonstrated. The fundamental ideas, measurements, and analytic/numerical modeling will be applied to mixed-wet

  1. Fundamentals of reservoir surface energy as related to surface properties, wettability, capillary action, and oil recovery from fractured reservoirs by spontaneous imbibition

    Energy Technology Data Exchange (ETDEWEB)

    Norman R. Morrow; Herbert Fischer; Yu Li; Geoffrey Mason; Douglas Ruth; Siddhartha Seth; Jason Zhengxin Tong; Peigui Yin; Shaochang Wo

    2006-06-08

    The objective of this project is to increase oil recovery from fractured reservoirs through improved fundamental understanding of the process of spontaneous imbibition by which oil is displaced from the rock matrix into the fractures. Spontaneous imbibition is fundamentally dependent on the reservoir surface free energy but this has never been investigated for rocks. In this project, the surface free energy of rocks will be determined by using liquids that can be solidified within the rock pore space at selected saturations. Thin sections of the rock then provide a two-dimensional view of the rock minerals and the occupant phases. Saturations and oil/rock, water/rock, and oil/water surface areas will be determined by advanced petrographic analysis and the surface free energy which drives spontaneous imbibition will be determined as a function of increase in wetting phase saturation. The inherent loss in surface free energy resulting from capillary instabilities at the microscopic (pore level) scale will be distinguished from the decrease in surface free energy that drives spontaneous imbibition. A mathematical network/numerical model will be developed and tested against experimental results of recovery versus time over broad variation of key factors such as rock properties, fluid phase viscosities, sample size, shape and boundary conditions. Two fundamentally important, but not previously considered, parameters of spontaneous imbibition, the capillary pressure acting to oppose production of oil at the outflow face and the pressure in the non-wetting phase at the no-flow boundary versus time, will also be measured and modeled. Simulation and network models will also be tested against special case solutions provided by analytic models. In the second stage of the project, application of the fundamental concepts developed in the first stage of the project will be demonstrated. The fundamental ideas, measurements, and analytic/numerical modeling will be applied to mixed-wet

  2. Differences in the heat stress associated with white sportswear and being semi-nude in exercising humans under conditions of radiant heat and wind at a wet bulb globe temperature of greater than 28 °C

    Science.gov (United States)

    Tsuji, Michio; Kume, Masashi; Tuneoka, Hideyuki; Yoshida, Tetsuya

    2014-08-01

    This study investigated whether wearing common white sportswear can reduce heat stress more than being semi-nude during exercise of different intensities performed under radiant heat and wind conditions, such as a hot summer day. After a 20-min rest period, eight male subjects performed three 20 min sessions of cycling exercise at a load intensity of 20 % or 50 % of their peak oxygen uptake (VO2peak) in a room maintained at a wet bulb globe temperature (WBGT) of 28.7 ± 0.1 °C using two spot lights and a fan (0.8 m/s airflow). Subjects wore common white sportswear (WS) consisting of a long-sleeved shirt (45 % cotton and 55 % polyester) and short pants (100 % polyester), or only swimming pants (SP) under the semi-nude condition. The mean skin temperature was greater when subjects wore SP than WS under both the 20 % and 50 % exercise conditions. During the 50 % exercise, the rating of perceived exertion (RPE) and thermal sensation (TS), and the increases in esophageal temperature (ΔTes) and heart rate were significantly higher ( P < 0.001-0.05), or tended to be higher ( P < 0.07), in the WS than SP trials at the end of the third 20-min exercise session. The total sweat loss ( m sw,tot) was also significantly higher in the WS than in the SP trials ( P < 0.05). However, during the 20 % exercise, the m sw,tot during exercise, and the ΔTes, RPE and TS at the end of the second and third sessions of exercise did not differ significant between conditions. The heat storage (S), calculated from the changes in the mean body temperature (0.9Tes + 0.1 ), was significantly lower in the WS trials than in the SP trials during the 20 min resting period before exercise session. However, S was similar between conditions during the 20 % exercise, but was greater in the WS than in the SP trials during 50 % exercise. These results suggest that, under conditions of radiant heat and wind at a WBGT greater than 28 °C, the heat stress associated with wearing common WS is similar to that

  3. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions. [Lower Rio Grande Valley Test Site: Weslaco, Texas; Falco Reservoir and the Gulf of Mexico

    Science.gov (United States)

    Wiegand, C. L.; Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J. (Principal Investigator)

    1980-01-01

    The author has identified the following significant results. HCMM day/night coverage 12 hours apart cannot be obtained at 26 deg N latitude; nor have any pairs 36 hours apart been obtained. A day-IR scene and a night scene for two different dates were analyzed. A profile across the test site for the same latitude shows that the two profiles are near mirror images of each other over land surfaces and that the temperature of two large water bodies, Falcon Reservoir and the Gulf of Mexico, are nearly identical on two dates. During the time interval between overpasses, the vegetative cover remained static due to winter dormancy. The data suggest that day/night temperature differences measured weeks apart may yield meaningful information about the contrast between daytime maximum and nighttime minimum temperatures for a given site.

  4. Upper Hiwassee River Basin reservoirs 1989 water quality assessment

    International Nuclear Information System (INIS)

    Fehring, J.P.

    1991-08-01

    The water in the Upper Hiwassee River Basin is slightly acidic and low in conductivity. The four major reservoirs in the Upper Hiwassee River Basin (Apalachia, Hiwassee, Chatuge, and Nottely) are not threatened by acidity, although Nottely Reservoir has more sulfates than the other reservoirs. Nottely also has the highest organic and nutrient concentrations of the four reservoirs. This results in Nottely having the poorest water clarity and the most algal productivity, although clarity as measured by color and secchi depths does not indicate any problem with most water use. However, chlorophyll concentrations indicate taste and odor problems would be likely if the upstream end of Nottely Reservoir were used for domestic water supply. Hiwassee Reservoir is clearer and has less organic and nutrient loading than either of the two upstream reservoirs. All four reservoirs have sufficient algal activity to produce supersaturated dissolved oxygen conditions and relatively high pH values at the surface. All four reservoirs are thermally stratified during the summer, and all but Apalachia have bottom waters depleted in oxygen. The very short residence time of Apalachia Reservoir, less than ten days as compared to over 100 days for the other three reservoirs, results in it being more riverine than the other three reservoirs. Hiwassee Reservoir actually develops three distinct water temperature strata due to the location of the turbine intake. The water quality of all of the reservoirs supports designated uses, but water quality complaints are being received regarding both Chatuge and Nottely Reservoirs and their tailwaters

  5. Wetting 101 degrees.

    Science.gov (United States)

    Gao, Lichao; McCarthy, Thomas J

    2009-12-15

    We review our 2006-2009 publications on wetting and superhydrophobicity in a manner designed to serve as a useful primer for those who would like to use the concepts of this field. We demonstrate that the 1D (three-phase, solid/liquid/vapor) contact line perspective is simpler, more intuitive, more useful, and more consistent with facts than the disproved but widely held-to-be-correct 2D view. We give an explanation of what we believe to be the reason that the existing theoretical understanding is wrong and argue that the teaching of surface science over the last century has led generations of students and scientists to a misunderstanding of the wetting of solids by liquids. We review our analyses of the phenomena of contact angle hysteresis, the lotus effect, and perfect hydrophobicity and suggest that needlessly complex theoretical understandings, incorrect models, and ill-defined terminology are not useful and can be destructive.

  6. Wetting of porous solids.

    Science.gov (United States)

    Patkar, Saket; Chaudhuri, Parag

    2013-09-01

    This paper presents a simple, three stage method to simulate the mechanics of wetting of porous solid objects, like sponges and cloth, when they interact with a fluid. In the first stage, we model the absorption of fluid by the object when it comes in contact with the fluid. In the second stage, we model the transport of absorbed fluid inside the object, due to diffusion, as a flow in a deforming, unstructured mesh. The fluid diffuses within the object depending on saturation of its various parts and other body forces. Finally, in the third stage, oversaturated parts of the object shed extra fluid by dripping. The simulation model is motivated by the physics of imbibition of fluids into porous solids in the presence of gravity. It is phenomenologically capable of simulating wicking and imbibition, dripping, surface flows over wet media, material weakening, and volume expansion due to wetting. The model is inherently mass conserving and works for both thin 2D objects like cloth and for 3D volumetric objects like sponges. It is also designed to be computationally efficient and can be easily added to existing cloth, soft body, and fluid simulation pipelines.

  7. CO2 wettability of seal and reservoir rocks and the implications for carbon geo-sequestration

    Science.gov (United States)

    Iglauer, Stefan; Pentland, C. H.; Busch, A.

    2015-01-01

    We review the literature data published on the topic of CO2 wettability of storage and seal rocks. We first introduce the concept of wettability and explain why it is important in the context of carbon geo-sequestration (CGS) projects, and review how it is measured. This is done to raise awareness of this parameter in the CGS community, which, as we show later on in this text, may have a dramatic impact on structural and residual trapping of CO2. These two trapping mechanisms would be severely and negatively affected in case of CO2-wet storage and/or seal rock. Overall, at the current state of the art, a substantial amount of work has been completed, and we find that:Sandstone and limestone, plus pure minerals such as quartz, calcite, feldspar, and mica are strongly water wet in a CO2-water system.Oil-wet limestone, oil-wet quartz, or coal is intermediate wet or CO2 wet in a CO2-water system.The contact angle alone is insufficient for predicting capillary pressures in reservoir or seal rocks.The current contact angle data have a large uncertainty.Solid theoretical understanding on a molecular level of rock-CO2-brine interactions is currently limited.In an ideal scenario, all seal and storage rocks in CGS formations are tested for their CO2 wettability.Achieving representative subsurface conditions (especially in terms of the rock surface) in the laboratory is of key importance but also very challenging.

  8. Water resources review: Wheeler Reservoir, 1990

    Energy Technology Data Exchange (ETDEWEB)

    Wallus, R.; Cox, J.P.

    1990-09-01

    Protection and enhancement of water quality is essential for attaining the full complement of beneficial uses of TVA reservoirs. The responsibility for improving and protecting TVA reservoir water quality is shared by various federal, state, and local agencies, as well as the thousands of corporations and property owners whose individual decisions affect water quality. TVA's role in this shared responsibility includes collecting and evaluating water resources data, disseminating water resources information, and acting as a catalyst to bring together agencies and individuals that have a responsibility or vested interest in correcting problems that have been identified. This report is one in a series of status reports that will be prepared for each of TVA's reservoirs. The purpose of this status report is to provide an up-to-date overview of the characteristics and conditions of Wheeler Reservoir, including: reservoir purposes and operation; physical characteristics of the reservoir and the watershed; water quality conditions: aquatic biological conditions: designated, actual, and potential uses of the reservoir and impairments of those uses; ongoing or planned reservoir management activities. Information and data presented here are form the most recent reports, publications, and original data available. 21 refs., 8 figs., 29 tabs.

  9. Reservoir fisheries of Asia

    International Nuclear Information System (INIS)

    Silva, S.S. De.

    1990-01-01

    At a workshop on reservoir fisheries research, papers were presented on the limnology of reservoirs, the changes that follow impoundment, fisheries management and modelling, and fish culture techniques. Separate abstracts have been prepared for three papers from this workshop

  10. The wetting transition in water

    Science.gov (United States)

    Friedman, Serah Ruth

    This work addresses both the design and experimental procedure for finding the wetting transition in water on a variety of solid surfaces. When a liquid drop is placed onto a solid surface it will either completely spread out or form a finite contact angle between 0 and 180 degrees. When a drop spreads, forming a film across the surface, this is called complete wetting. If a drop forms a finite contact angle with the surface, this is called partial wetting. A wetting transition is a surface phase transition from partial to complete wetting. This work is the first to experimentally measure the wetting transition in water on a solid surface. The temperature at which the wetting transition occurs is called the wetting temperature. The wetting temperature for solid-liquid-vapor systems can be theoretically predicted using both molecular dynamics simulations and density functional theory. Density functional theory predicts, with reasonable accuracy, the wetting temperature of "simple" non-polar liquids on a solid surface. The accuracy of density functional theory in predicting wetting temperature has yet to be experimentally tested on more complex polar liquids, and more specifically on water. In this work, we set out to measure the wetting transition in water on a variety of surfaces, namely: Graphite, Sapphire, Quartz, Mica, Gold, Silicon and Hexagonal Boron Nitride.

  11. The impact of intermediate wet states on two-phase flow in porous media, studied by network modelling

    Energy Technology Data Exchange (ETDEWEB)

    Hoeiland, Linda Kaada

    2006-04-15

    Reservoir wettability is a measure of a rocks preference for the oil and/or the brine phase. Wettability has a dominant impact on fluid movements in porous media, hence oil displacement in reservoir rocks. Understanding the local wettability and the effect of wettability on the fluid movements are therefore of interest in relation to oil recovery processes. Contrary to the earlier believed homogenous wetted cases where the porous media was strongly oil-wet for carbonate reservoirs or strongly water-wet for clastic reservoirs, it is now believed that most reservoir rocks experience some kind of intermediate wet state. Since wettability affects oil recovery, different classes of intermediate wettability are expected to have different impacts on the fluid flow processes. The major subject treated in this thesis is how different intermediate wet states affect fluid flow parameters which are important for the oil recovery. This is done by use of a capillary dominated network model of two-phase flow, where the network is based on a model of reconstructed sandstone. The existence of different intermediate wet classes is argued in Paper I, while Paper II, III and IV analyse the effect different intermediate wet classes have on wettability indices, residual oil saturation, capillary pressure and relative permeability (author)

  12. On the CO2 Wettability of Reservoir Rocks: Addressing Conflicting Information

    Science.gov (United States)

    Garing, C.; Wang, S.; Tokunaga, T. K.; Wan, J.; Benson, S. M.

    2017-12-01

    Conventional wisdom is that siliclastic rocks are strongly water wet for the CO2-brine system, leading to high irreducible water saturation, moderate residual gas trapping and implying that tight rocks provide efficient seals for buoyant CO2. If the wetting properties become intermediate or CO2 wet, the conclusions regarding CO2 flow and trapping could be very different. Addressing the CO2 wettability of seal and reservoir rocks is therefore essential to predict CO2 storage in geologic formation. Although a substantial amount of work has been dedicated to the topic, contact angle data show a large variability and experiments on plates, micromodels and cores report conflicting results regarding the influence of supercritical CO2 (scCO2) exposure on wetting properties: whereas some experimental studies suggest dewetting upon reaction with scCO2, some others observe no wettability alteration under reservoir scCO2 conditions. After reviewing evidences for and against wettability changes associated with scCO2, we discuss potential causes for differences in experimental results. They include the presence of organic matter and impact of sample treatment, the type of media (non consolidated versus real rock), experimental time and exposure to scCO2, and difference in measurement system (porous plate versus stationary fluid method). In order to address these points, new scCO2/brine drainage-imbibition experiments were conducted on a same Berea sandstone rock core, first untreated, then fired and finally exposed to scCO2 for three weeks, using the stationary fluid method. The results are compared to similar experiments performed on quartz sands, untreated and then baked, using the porous plate method. In addition, a comparative experiment using the same Idaho gray sandstone rock core was performed with both the porous plate and the stationary fluid methods to investigate possible method-dependent results.

  13. Reservoir simulation with imposed flux continuity conditions on heterogeneous and anisotropic media for general geometries, and the inclusion of hysteresis in forward modeling

    Energy Technology Data Exchange (ETDEWEB)

    Eigestad, Geir Terje

    2003-04-01

    The thesis is divided into two main parts. Part I gives an overview and summary of the theory that lies behind the flow equations and the discretization principles used in the work. Part II is a collection of research papers that have been written by the candidate (in collaboration with others). The main objective of this thesis is the discretization of an elliptic PDE which describes the pressure in a porous medium. The porous medium will in general be described by permeability tensors which are heterogeneous and anisotropic. In addition, the geometry is often complex for practical applications. This requires discretization approaches that are suited for the problems in mind. The discretization approaches used here are based on imposed flux and potential continuity, and will be discussed in detail in Chapter 3 of Part I. These methods are called Multi Point Flux Approximation Methods, and the acronym MPFA will be used for them. Issues related to these methods will be the main issue of this thesis. The rest of this thesis is organised as follows: Part I: Chapter 1 gives a brief overview of the physics and mathematics behind reservoir simulation. The standard mass balance equations are presented, and we try to explain what reservoir simulation is. Some standard discretization s methods are briefly discussed in Chapter 2. The main focus in Part I is on the MPFA discretization approach for various geometries, and is given in Chapter 3. Some details may have been left out in the papers of Part II, and the section serves both as a summary of the discretization method(s), as well as a more detailed description than what is found in the papers. In Chapter 4, extensions to handle time dependent and nonlinear problems are discussed. Some of the numerical examples presented in Part II deal with two phase flow, and are based on the extension given in this chapter. Chapter 5 discusses numerical results that have been obtained for the MPFA methods for elliptic problems, and

  14. Double Barreled Wet Colostomy: Initial Experience and Literature Review

    OpenAIRE

    Luis Salgado-Cruz; Eloy Espin-Basany; Francesc Vallribera-Valls; Jose Sanchez-Garcia; Luis Miguel Jimenez-Gomez; Marc Marti-Gallostra; Ana Garza-Maldonado

    2014-01-01

    Background. Pelvic exenteration and multivisceral resection in colorectal have been described as a curative and palliative intervention. Urinary tract reconstruction in a pelvic exenteration is achieved in most cases with an ileal conduit of Bricker, although different urinary reservoirs have been described. Methods. A retrospective and observational study of six patients who underwent a pelvic exenteration and urinary tract reconstruction with a double barreled wet colostomy (DBWC) was done,...

  15. Installation of a Devonian Shale Reservoir Testing Facility and acquisition of reservoir property measurements

    Energy Technology Data Exchange (ETDEWEB)

    Locke, C.D.; Salamy, S.P.

    1991-09-01

    In October, a contract was awarded for the Installation of a Devonian Shale Reservoir Testing Facility and Acquisition of Reservoir Property measurements from wells in the Michigan, Illinois, and Appalachian Basins. Geologic and engineering data collected through this project will provide a better understanding of the mechanisms and conditions controlling shale gas production. This report summarizes the results obtained from the various testing procedures used at each wellsite and the activities conducted at the Reservoir Testing Facility.

  16. Installation of a Devonian Shale Reservoir Testing Facility and acquisition of reservoir property measurements. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Locke, C.D.; Salamy, S.P.

    1991-09-01

    In October, a contract was awarded for the Installation of a Devonian Shale Reservoir Testing Facility and Acquisition of Reservoir Property measurements from wells in the Michigan, Illinois, and Appalachian Basins. Geologic and engineering data collected through this project will provide a better understanding of the mechanisms and conditions controlling shale gas production. This report summarizes the results obtained from the various testing procedures used at each wellsite and the activities conducted at the Reservoir Testing Facility.

  17. Stream, Lake, and Reservoir Management.

    Science.gov (United States)

    Dai, Jingjing; Mei, Ying; Chang, Chein-Chi

    2017-10-01

    This review on stream, lake, and reservoir management covers selected 2016 publications on the focus of the following sections: Stream, lake, and reservoir management • Water quality of stream, lake, and reservoirReservoir operations • Models of stream, lake, and reservoir • Remediation and restoration of stream, lake, and reservoir • Biota of stream, lake, and reservoir • Climate effect of stream, lake, and reservoir.

  18. Optical wet steam monitor

    Science.gov (United States)

    Maxey, L.C.; Simpson, M.L.

    1995-01-17

    A wet steam monitor determines steam particle size by using laser doppler velocimeter (LDV) device to produce backscatter light. The backscatter light signal is processed with a spectrum analyzer to produce a visibility waveform in the frequency domain. The visibility waveform includes a primary peak and a plurality of sidebands. The bandwidth of at least the primary frequency peak is correlated to particle size by either visually comparing the bandwidth to those of known particle sizes, or by digitizing the waveform and comparing the waveforms electronically. 4 figures.

  19. Model based management of a reservoir system

    Energy Technology Data Exchange (ETDEWEB)

    Scharaw, B.; Westerhoff, T. [Fraunhofer IITB, Ilmenau (Germany). Anwendungszentrum Systemtechnik; Puta, H.; Wernstedt, J. [Technische Univ. Ilmenau (Germany)

    2000-07-01

    The main goals of reservoir management systems consist of prevention against flood water damages, the catchment of raw water and keeping all of the quality parameters within their limits besides controlling the water flows. In consideration of these goals a system model of the complete reservoir system Ohra-Schmalwasser-Tambach Dietharz was developed. This model has been used to develop optimized strategies for minimization of raw water production cost, for maximization of electrical energy production and to cover flood situations, as well. Therefore a proper forecast of the inflow to the reservoir from the catchment areas (especially flooding rivers) and the biological processes in the reservoir is important. The forecast model for the inflow to the reservoir is based on the catchment area model of Lorent and Gevers. It uses area precipitation, water supply from the snow cover, evapotranspiration and soil wetness data to calculate the amount of flow in rivers. The other aim of the project is to ensure the raw water quality using quality models, as well. Then a quality driven raw water supply will be possible. (orig.)

  20. Handling of wet residues in industry

    DEFF Research Database (Denmark)

    Villanueva, Alejandro

    to water bodies and uses of such bodies, distance to available agricultural land, characteristics of the local wastewater treatment plant, local and national legislation, or availability of subsidies. This study uses as example the geographical, legislative, economic and social boundary conditions......In countries with high prices of fresh water use and wastewater discharge, water recycling has become an alternative to traditional water consumption and discharge for industries with water-based processes. Industrial water recycling means in many cases that water has to be treated and cleaned......, to remove from it the substances which presence impedes reusing the water. These substances accumulate in a by-product called wet residue. An integral part of water recycling projects in the industry is the handling and disposal of the wet residues generated. The treatment, utilisation and disposal of wet...

  1. Wet-cupping removes oxidants and decreases oxidative stress.

    Science.gov (United States)

    Tagil, Suleyman Murat; Celik, Huseyin Tugrul; Ciftci, Sefa; Kazanci, Fatmanur Hacievliyagil; Arslan, Muzeyyen; Erdamar, Nazan; Kesik, Yunus; Erdamar, Husamettin; Dane, Senol

    2014-12-01

    Wet-cupping therapy is one of the oldest known medical techniques. Although it is widely used in various conditions such as acute\\chronic inflammation, infectious diseases, and immune system disorders, its mechanism of action is not fully known. In this study, we investigated the oxidative status as the first step to elucidate possible mechanisms of action of wet cupping. Wet cupping therapy is implemented to 31 healthy volunteers. Venous blood samples and Wet cupping blood samples were taken concurrently. Serum nitricoxide, malondialdehyde levels and activity of superoxide dismutase and myeloperoxidase were measured spectrophotometrically. Wet cupping blood had higher activity of myeloperoxidase, lower activity of superoxide dismutase, higher levels of malondialdehyde and nitricoxide compared to the venous blood. Wet cupping removes oxidants and decreases oxidative stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Pacifiers: a microbial reservoir.

    Science.gov (United States)

    Comina, Elodie; Marion, Karine; Renaud, François N R; Dore, Jeanne; Bergeron, Emmanuelle; Freney, Jean

    2006-12-01

    The permanent contact between the nipple part of pacifiers and the oral microflora offers ideal conditions for the development of biofilms. This study assessed the microbial contamination on the surface of 25 used pacifier nipples provided by day-care centers. Nine were made of silicone and 16 were made of latex. The biofilm was quantified using direct staining and microscopic observations followed by scraping and microorganism counting. The presence of a biofilm was confirmed on 80% of the pacifier nipples studied. This biofilm was mature for 36% of them. Latex pacifier nipples were more contaminated than silicone ones. The two main genera isolated were Staphylococcus and Candida. Our results confirm that nipples can be seen as potential reservoirs of infections. However, pacifiers do have some advantages; in particular, the potential protection they afford against sudden infant death syndrome. Strict rules of hygiene and an efficient antibiofilm cleaning protocol should be established to answer the worries of parents concerning the safety of pacifiers.

  3. PREFACE: Wetting: introductory note

    Science.gov (United States)

    Herminghaus, S.

    2005-03-01

    The discovery of wetting as a topic of physical science dates back two hundred years, to one of the many achievements of the eminent British scholar Thomas Young. He suggested a simple equation relating the contact angle between a liquid surface and a solid substrate to the interfacial tensions involved [1], γlg cos θ = γsg - γsl (1) In modern terms, γ denotes the excess free energy per unit area of the interface indicated by its indices, with l, g and s corresponding to the liquid, gas and solid, respectively [2]. After that, wetting seems to have been largely ignored by physicists for a long time. The discovery by Gabriel Lippmann that θ may be tuned over a wide range by electrochemical means [3], and some important papers about modifications of equation~(1) due to substrate inhomogeneities [4,5] are among the rare exceptions. This changed completely during the seventies, when condensed matter physics had become enthusiastic about critical phenomena, and was vividly inspired by the development of the renormalization group by Kenneth Wilson [6]. This had solved the long standing problem of how to treat fluctuations, and to understand the universal values of bulk critical exponents. By inspection of the critical exponents of the quantities involved in equation~(1), John W Cahn discovered what he called critical point wetting: for any liquid, there should be a well-defined transition to complete wetting (i.e., θ = 0) as the critical point of the liquid is approached along the coexistence curve [7]. His paper inspired an enormous amount of further work, and may be legitimately viewed as the entrance of wetting into the realm of modern physics. Most of the publications directly following Cahn's work were theoretical papers which elaborated on wetting in relation to critical phenomena. A vast amount of interesting, and in part quite unexpected, ramifications were discovered, such as the breakdown of universality in thin film systems [8]. Simultaneously, a number

  4. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2014-03-01

    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  5. Stochastic Reservoir Characterization Constrained by Seismic Data

    Energy Technology Data Exchange (ETDEWEB)

    Eide, Alfhild Lien

    1999-07-01

    In order to predict future production of oil and gas from a petroleum reservoir, it is important to have a good description of the reservoir in terms of geometry and physical parameters. This description is used as input to large numerical models for the fluid flow in the reservoir. With increased quality of seismic data, it is becoming possible to extend their use from the study of large geologic structures such as seismic horizons to characterization of the properties of the reservoir between the horizons. Uncertainties because of the low resolution of seismic data can be successfully handled by means of stochastic modeling, and spatial statistics can provide tools for interpolation and simulation of reservoir properties not completely resolved by seismic data. This thesis deals with stochastic reservoir modeling conditioned to seismic data and well data. Part I presents a new model for stochastic reservoir characterization conditioned to seismic traces. Part II deals with stochastic simulation of high resolution impedance conditioned to measured impedance. Part III develops a new stochastic model for calcite cemented objects in a sandstone background; it is a superposition of a marked point model for the calcites and a continuous model for the background.

  6. FUNDAMENTALS OF RESERVOIR SURFACE ENERGY AS RELATED TO SURFACE PROPERTIES, WETTABILITY, CAPILLARY ACTION, AND OIL RECOVERY FROM FRACTURED RESERVOIRS BY SPONTANEOUS IMBIBITION

    Energy Technology Data Exchange (ETDEWEB)

    Norman R. Morrow; Herbert Fischer; Yu Li; Geoffrey Mason; Douglas Ruth; Siddhartha Seth; Peigui Yin; Shaochang Wo

    2004-10-01

    The objective of this project is to increase oil recovery from fractured reservoirs through improved fundamental understanding of the process of spontaneous imbibition by which oil is displaced from the rock matrix into the fractures. Spontaneous imbibition is fundamentally dependent on the reservoir surface free energy but this has never been investigated for rocks. In this project, the surface free energy of rocks will be determined by using liquids that can be solidified within the rock pore space at selected saturations. Thin sections of the rock then provide a two-dimensional view of the rock minerals and the occupant phases. Saturations and oil/rock, water/rock, and oil/water surface areas will be determined by advanced petrographic analysis and the surface free energy which drives spontaneous imbibition will be determined as a function of increase in wetting phase saturation. The inherent loss in surface free energy resulting from capillary instabilities at the microscopic (pore level) scale will be distinguished from the decrease in surface free energy that drives spontaneous imbibition. A mathematical network/numerical model will be developed and tested against experimental results of recovery versus time over broad variation of key factors such as rock properties, fluid phase viscosities, sample size, shape and boundary conditions. Two fundamentally important, but not previously considered, parameters of spontaneous imbibition, the capillary pressure acting to oppose production of oil at the outflow face and the pressure in the nonwetting phase at the no-flow boundary versus time, will also be measured and modeled. Simulation and network models will also be tested against special case solutions provided by analytic models. In the second stage of the project, application of the fundamental concepts developed in the first stage of the project will be demonstrated. The fundamental ideas, measurements, and analytic/numerical modeling will be applied to mixed-wet

  7. Comparisons of Simulated Hydrodynamics and Water Quality for Projected Demands in 2046, Pueblo Reservoir, Southeastern Colorado

    Science.gov (United States)

    Ortiz, Roderick F.; Galloway, Joel M.; Miller, Lisa D.; Mau, David P.

    2008-01-01

    Pueblo Reservoir is one of southeastern Colorado's most valuable water resources. The reservoir provides irrigation, municipal, and industrial water to various entities throughout the region. The reservoir also provides flood control, recreational activities, sport fishing, and wildlife enhancement to the region. The Bureau of Reclamation is working to meet its goal to issue a Final Environmental Impact Statement (EIS) on the Southern Delivery System project (SDS). SDS is a regional water-delivery project that has been proposed to provide a safe, reliable, and sustainable water supply through the foreseeable future (2046) for Colorado Springs, Fountain, Security, and Pueblo West. Discussions with the Bureau of Reclamation and the U.S. Geological Survey led to a cooperative agreement to simulate the hydrodynamics and water quality of Pueblo Reservoir. This work has been completed and described in a previously published report, U.S. Geological Survey Scientific Investigations Report 2008-5056. Additionally, there was a need to make comparisons of simulated hydrodynamics and water quality for projected demands associated with the various EIS alternatives and plans by Pueblo West to discharge treated water into the reservoir. Plans by Pueblo West are fully independent of the SDS project. This report compares simulated hydrodynamics and water quality for projected demands in Pueblo Reservoir resulting from changes in inflow and water quality entering the reservoir, and from changes to withdrawals from the reservoir as projected for the year 2046. Four of the seven EIS alternatives were selected for scenario simulations. The four U.S. Geological Survey simulation scenarios were the No Action scenario (EIS Alternative 1), the Downstream Diversion scenario (EIS Alternative 2), the Upstream Return-Flow scenario (EIS Alternative 4), and the Upstream Diversion scenario (EIS Alternative 7). Additionally, the results of an Existing Conditions scenario (water years 2000 through

  8. Destratification of an impounding reservoir using compressed air??case of Mudi reservoir, Blantyre, Malawi

    Science.gov (United States)

    Chipofya, V. H.; Matapa, E. J.

    This paper reviews the operational and cost effectiveness of a compressed air destratification system that was installed in the Mudi reservoir for destratifying the reservoir. Mudi reservoir is a raw water source for the Blantyre Water Board. It has a capacity of 1,400,000 cubic metres. The reservoir is 15.3 m deep at top water level. In the absence of any artificial circulation of air, the reservoir stratifies into two layers. There is a warm epilimnion in the top 3 m of the reservoir, with temperatures ranging from 23 to 26 °C. There is prolific algal growth in this layer. The bottom layer has much lower temperatures, and is oxygen deficient. Under such anaerobic conditions, ammonia, sulphides, iron and manganese are released from the sediments of the reservoir. As a result of nutrient inflow from the catchments, coupled with tropical ambient temperatures, the reservoir is most times infested with blue-green algae. This results into water treatment problems in respect of taste and odour and iron and manganese soluble salts. To abate such problems, air is artificially circulated in the reservoir, near the intake tower, through a perforated pipe that is connected to an electrically driven compressor. This causes artificial circulation of water in the hypolimnion region of the reservoir. As a result of this circulation, a hostile environment that inhibits the propagation of algae is created. Dissolved oxygen and temperature profiles are practically uniform from top to bottom of reservoir. Concentrations of iron and manganese soluble salts are much reduced at any of the draw-off points available for the water treatment process. The paper concludes by highlighting the significant cost savings in water treatment that are accrued from the use of compressed air destratification in impounding water storage reservoirs for the control of algae and other chemical pollutants.

  9. Adsorption of hydrocarbons in chalk reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, L.

    1996-12-31

    The present work is a study on the wettability of hydrocarbon bearing chalk reservoirs. Wettability is a major factor that influences flow, location and distribution of oil and water in the reservoir. The wettability of the hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. Organic compounds such as carboxylic acids are found in formation waters from various hydrocarbon reservoirs and in crude oils. In the present investigation the wetting behaviour of chalk is studied by the adsorption of the carboxylic acids onto synthetic calcite, kaolinite, quartz, {alpha}-alumina, and chalk dispersed in an aqueous phase and an organic phase. In the aqueous phase the results clearly demonstrate the differences between the adsorption behaviour of benzoic acid and hexanoic acid onto the surfaces of oxide minerals and carbonates. With NaCl concentration of 0.1 M and with pH {approx_equal} 6 the maximum adsorption of benzoic acid decreases in the order: quartz, {alpha}-alumina, kaolinite. For synthetic calcite and chalk no detectable adsorption was obtaind. In the organic phase the order is reversed. The maximum adsorption of benzoic acid onto the different surfaces decreases in the order: synthetic calcite, chalk, kaolinite and quartz. Also a marked difference in adsorption behaviour between probes with different functional groups onto synthetic calcite from organic phase is observed. The maximum adsorption decreases in the order: benzoic acid, benzyl alcohol and benzylamine. (au) 54 refs.

  10. Characteristics of wetting temperature during spray cooling

    International Nuclear Information System (INIS)

    Mitsutake, Yuichi; Monde, Masanori; Hidaka, Shinichirou

    2006-01-01

    An experimental study has been done to elucidate the effects of mass flux and subcooling of liquid and thermal properties of solid on the wetting temperature during cooling of a hot block with spray. A water spray was impinged at one of the end surfaces of a cylindrical block initially heated at 400 or 500degC. The experimental condition was mass fluxes G=1-9 kg/m 2 s and degrees of subcooling ΔT sub =20, 50, 80 K. Three blocks of copper, brass and carbon steel were prepared. During spray cooling internal block temperature distribution and sputtering sound pressure level were recorded and the surface temperature and heat flux were evaluated with 2D inverse heat conducting analysis. Cooling process on cooling curves is divided into four regimes categorized by change in a flow situation and the sound level. The wetting temperature defined as the wall temperature at a minimum heat flux point was measured over an extensive experimental range. The wetting wall temperature was correlated well with the parameter of GΔT sub . The wetting wall temperature increases as GΔT sub increases and reaches a constant value depending on the material of the surface at higher region of GΔT sub . (author)

  11. A Percolation Study of Wettability Effect on the Electrical Properties of Reservoir Rocks

    DEFF Research Database (Denmark)

    Zhou, Dengen; Arbabi, Sepehr; Stenby, Erling Halfdan

    1997-01-01

    Measurements of the electrical resistivity of oil reservoirs are commonly used to estimate other properties of reservoirs, such as porosity and hydrocarbon reserves. However, the interpretation of the measurements is based on empirical correlations, because the underlying mechanisms that control...... the electrical properties of oil bearing rocks have not been well understood. In this paper, we employ percolation concepts to investigate the effect of wettability on the electrical conductivity of a reservoir formation. A three-dimensional simple cubic network is used to represent an ideal reservoir formation...... behavior of reservoir resistivities of different wettabilities. It demonstrates that the resistivity index depends on saturation history and wettability. For strongly oil-wet systems, significant hysteresis is expected, while there is little hysteresis for strongly water-wet systems, and some hysteresis...

  12. Transport of reservoir fines

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander; Stenby, Erling Halfdan

    Modeling transport of reservoir fines is of great importance for evaluating the damage of production wells and infectivity decline. The conventional methodology accounts for neither the formation heterogeneity around the wells nor the reservoir fines’ heterogeneity. We have developed an integral...

  13. SILTATION IN RESERVOIRS

    African Journals Online (AJOL)

    Calls have been made to the government through various media to assist its populace in combating this nagging problem. It was concluded that sediment maximum accumulation is experienced in reservoir during the periods of maximum flow. Keywords: reservoir model, siltation, sediment, catchment, sediment transport. 1.

  14. Dynamic reservoir well interaction

    NARCIS (Netherlands)

    Sturm, W.L.; Belfroid, S.P.C.; Wolfswinkel, O. van; Peters, M.C.A.M.; Verhelst, F.J.P.C.M.

    2004-01-01

    In order to develop smart well control systems for unstable oil wells, realistic modeling of the dynamics of the well is essential. Most dynamic well models use a semi-steady state inflow model to describe the inflow of oil and gas from the reservoir. On the other hand, reservoir models use steady

  15. Reservoir Engineering Management Program

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.; Schwarz, W.J.

    1977-12-14

    The Reservoir Engineering Management Program being conducted at Lawrence Berkeley Laboratory includes two major tasks: 1) the continuation of support to geothermal reservoir engineering related work, started under the NSF-RANN program and transferred to ERDA at the time of its formation; 2) the development and subsequent implementation of a broad plan for support of research in topics related to the exploitation of geothermal reservoirs. This plan is now known as the GREMP plan. Both the NSF-RANN legacies and GREMP are in direct support of the DOE/DGE mission in general and the goals of the Resource and Technology/Resource Exploitation and Assessment Branch in particular. These goals are to determine the magnitude and distribution of geothermal resources and reduce risk in their exploitation through improved understanding of generically different reservoir types. These goals are to be accomplished by: 1) the creation of a large data base about geothermal reservoirs, 2) improved tools and methods for gathering data on geothermal reservoirs, and 3) modeling of reservoirs and utilization options. The NSF legacies are more research and training oriented, and the GREMP is geared primarily to the practical development of the geothermal reservoirs. 2 tabs., 3 figs.

  16. What's So Bad about Being Wet All Over: Investigating Leaf Surface Wetness.

    Science.gov (United States)

    Brewer, Carol A.

    1996-01-01

    Presents investigations of leaf surface wetness that provide ideal opportunities for students to explore the relationships between leaf form and function, to study surface conditions of leaves and plant physiology, and to make predictions about plant adaptation in different environments. Describes simple procedures for exploring questions related…

  17. Mathematical and field analysis of longitudinal reservoir infill

    Science.gov (United States)

    Ke, W. T.; Capart, H.

    2016-12-01

    In reservoirs, severe problems are caused by infilled sediment deposits. In long term, the sediment accumulation reduces the capacity of reservoir storage and flood control benefits. In the short term, the sediment deposits influence the intakes of water-supply and hydroelectricity generation. For the management of reservoir, it is important to understand the deposition process and then to predict the sedimentation in reservoir. To investigate the behaviors of sediment deposits, we propose a one-dimensional simplified theory derived by the Exner equation to predict the longitudinal sedimentation distribution in idealized reservoirs. The theory models the reservoir infill geomorphic actions for three scenarios: delta progradation, near-dam bottom deposition, and final infill. These yield three kinds of self-similar analytical solutions for the reservoir bed profiles, under different boundary conditions. Three analytical solutions are composed by error function, complementary error function, and imaginary error function, respectively. The theory is also computed by finite volume method to test the analytical solutions. The theoretical and numerical predictions are in good agreement with one-dimensional small-scale laboratory experiment. As the theory is simple to apply with analytical solutions and numerical computation, we propose some applications to simulate the long-profile evolution of field reservoirs and focus on the infill sediment deposit volume resulting the uplift of near-dam bottom elevation. These field reservoirs introduced here are Wushe Reservoir, Tsengwen Reservoir, Mudan Reservoir in Taiwan, Lago Dos Bocas in Puerto Rico, and Sakuma Dam in Japan.

  18. Comminution of B4C powders with a high-energy mill operated in air in dry or wet conditions and its effect on their spark-plasma sinterability

    DEFF Research Database (Denmark)

    Ortiz, Angel L.; Sánchez-Bajo, Florentino; Leal, Victor Manuel Candelario

    2017-01-01

    to the nanoscale. While this is accompanied by oxidation and aggregation, these are not serious drawbacks. Wet shaker milling in methanol (i.e., conventional ball-milling) resulted only in a moderate B4C particle refinement with greater contamination by the milling tools, which limits its usefulness. It was also......-plasma sintering confirmed this recommendation, and also showed the usefulness of dry shaker milling to obtain refined B4C microstructures for structural applications....

  19. conditions

    Directory of Open Access Journals (Sweden)

    M. Venkatesulu

    1996-01-01

    Full Text Available Solutions of initial value problems associated with a pair of ordinary differential systems (L1,L2 defined on two adjacent intervals I1 and I2 and satisfying certain interface-spatial conditions at the common end (interface point are studied.

  20. Should there be a "Wet" Soil Order in Soil Taxonomy?

    Science.gov (United States)

    Rabenhorst, Martin; Wessel, Barret; Stolt, Mark; Lindbo, David

    2017-04-01

    Early soil classification systems recognized wet soils at the highest categorical level. Among the Intrazonal Soils of the US classification utilized between the 1920s and 1960, were included as Great Soil Groups, the Wiesenboden, Bog, Half-Bog, Ground-Water Podzols and Ground-Water Laterites. In other systems, groups named with such terms as ground water gley and pseudogley were also used. With the advent of Soil Taxonomy and it's precursor (1960, 1975), Histosols (organic soils) were distinguished as one of the initial 10 soil orders, and while many of these organic soils are wet soils, some are not (Folists for example). Thus, for over 50 years, with the exception of Histosols, wet soils (which typically represent the wettest end of subaerial wet soils) have not been collectively recognized within taxa at the highest categorical level (order) in the US soil classification system. Rather, the wettest soils were designated at the second categorical level as wet (Aqu) suborders among the various soil orders, and more recently, subaqueous soils as "Wass" suborders of Entisols and Histosols. Soils with less-wet conditions have been recognized at the subgroup (4th) level. Further, in impoundments and regions of transgressing coastlines, submerged upland soils have been found that still classify in soil orders that do not accommodate subaqueous soils ("Wass" suborders). Notwithstanding, other contemporary soil classification systems do (have continued to) recognize wet soils at the highest level. In the World Reference Base (WRB) for example, wet soils are designated as Gleysols or Stagnosols. As efforts are underway to revisit, simplify, and revise Soil Taxonomy, questions have been raised regarding whether wet soils should again be moved back with a place among taxa at the highest category using a name such as Hydrasols, Aquasols, etc. This paper will explore and consider the questions and arguments for and against such proposals and the difficult question regarding

  1. Risk Analysis of Extreme Rainfall Effects on the Shihmen Reservoir

    Science.gov (United States)

    Ho, Y.; Lien, W.; Tung, C.

    2009-12-01

    Typhoon Morakot intruded Taiwan during 7th and 8th of August 2009, brought about 2,700 mm of total rainfall which caused serious flood and debris to the southern region of Taiwan. One of the serious flooded areas is in the downstream of Zengwen reservoir. People believed that the large amount of floodwater released from Zengwen reservoir led to the severe inundation. Therefore, the Shihmen reservoir is one of the important reservoirs in northern Taiwan. The Taipei metropolis, which is in downstream of Shihmen reservoir, is the political and economical center of Taiwan. If heavy rainfall as those brought by Typhoon Marakot falls in the Shihmen reservoir watershed, it may create a bigger disaster. This study focused on the impacts of a typhoon, like Morakot, in Shihmen reservoir. The hydrological model is used to simulate the reservoir inflows under different rainfall conditions. The reservoir water balance model is developed to calculate reservoir’s storage and outflows under the inflows and operational rules. The ability of flood mitigation is also evaluated. Besides, the released floodwater from reservoir and the inflows from different tributaries are used to determine whether or not the river stage will overtop levee. Also, the maximum released floodwater and other inflows which could lead to damages will be stated. Lastly, the criteria of rainfall conditions and initial stages of reservoir will be analyzed in this study.

  2. Sediment management for reservoir

    International Nuclear Information System (INIS)

    Rahman, A.

    2005-01-01

    All natural lakes and reservoirs whether on rivers, tributaries or off channel storages are doomed to be sited up. Pakistan has two major reservoirs of Tarbela and Managla and shallow lake created by Chashma Barrage. Tarbela and Mangla Lakes are losing their capacities ever since first impounding, Tarbela since 1974 and Mangla since 1967. Tarbela Reservoir receives average annual flow of about 62 MAF and sediment deposits of 0.11 MAF whereas Mangla gets about 23 MAF of average annual flows and is losing its storage at the rate of average 34,000 MAF annually. The loss of storage is a great concern and studies for Tarbela were carried out by TAMS and Wallingford to sustain its capacity whereas no study has been done for Mangla as yet except as part of study for Raised Mangla, which is only desk work. Delta of Tarbala reservoir has advanced to about 6.59 miles (Pivot Point) from power intakes. In case of liquefaction of delta by tremor as low as 0.12g peak ground acceleration the power tunnels I, 2 and 3 will be blocked. Minimum Pool of reservoir is being raised so as to check the advance of delta. Mangla delta will follow the trend of Tarbela. Tarbela has vast amount of data as reservoir is surveyed every year, whereas Mangla Reservoir survey was done at five-year interval, which has now been proposed .to be reduced to three-year interval. In addition suspended sediment sampling of inflow streams is being done by Surface Water Hydrology Project of WAPDA as also some bed load sampling. The problem of Chasma Reservoir has also been highlighted, as it is being indiscriminately being filled up and drawdown several times a year without regard to its reaction to this treatment. The Sediment Management of these reservoirs is essential and the paper discusses pros and cons of various alternatives. (author)

  3. Revised Comparisons of Simulated Hydrodynamics and Water Quality for Projected Demands in 2046, Pueblo Reservoir, Southeastern Colorado

    Science.gov (United States)

    Ortiz, Roderick F.; Miller, Lisa D.

    2009-01-01

    Pueblo Reservoir is one of southeastern Colorado's most valuable water resources. The reservoir provides irrigation, municipal, and industrial water to various entities throughout the region. The reservoir also provides flood control, recreational activities, sport fishing, and wildlife enhancement to the region. The Southern Delivery System (SDS) project is a regional water-delivery project that has been proposed to provide a safe, reliable, and sustainable water supply through the foreseeable future (2046) for Colorado Springs, Fountain, Security, and Pueblo West. Discussions with the Bureau of Reclamation and the U.S. Geological Survey led to a cooperative agreement to simulate the hydrodynamics and water quality of Pueblo Reservoir. This work has been completed and described in a previously published report, U.S. Geological Survey Scientific Investigations Report 2008-5056. Additionally, there was a need to make comparisons of simulated hydrodynamics and water quality for projected demands associated with the various Environmental Impact Statements (EIS) alternatives and plans by Pueblo West to discharge treated wastewater into the reservoir. Wastewater plans by Pueblo West are fully independent of the SDS project. This report compares simulated hydrodynamics and water quality for projected demands in Pueblo Reservoir resulting from changes in inflow and water quality entering the reservoir, and from changes to withdrawals from the reservoir as projected for the year 2046. Four of the seven EIS alternatives were selected for scenario simulations. The four U.S. Geological Survey simulation scenarios were the No Action scenario (EIS Alternative 1), the Downstream Diversion scenario (EIS Alternative 2), the Upstream Return-Flow scenario (EIS Alternative 4), and the Upstream Diversion scenario (EIS Alternative 7). Additionally, the results of an Existing Conditions scenario (year 2006 demand conditions) were compared to the No Action scenario (projected demands in

  4. High Frequency monitoring of cyanoHABs and cyanotoxin production to characterize periods of greatest risk on an inland reservoir

    Science.gov (United States)

    A monitoring approach combining wet chemistry and high frequency (HF) water quality sensors has been employed to improve our understanding of the ecology of an inland reservoir with a history of cyanoHAB events. Lake Harsha is a multi-use reservoir managed by the USACE in southwe...

  5. Fluid Assisted Compaction and Deformation of Reservoir Lithologies; FINAL

    International Nuclear Information System (INIS)

    Kronenberg, A.K.; Chester, F.M.; Chester, J.S.; Hajash, A.; He, W.; Karner, S.; Lenz, S.

    2002-01-01

    The compaction and diagenesis of sandstones that form reservoirs to hydrocarbons depend on mechanical compaction processes, fluid flow at local and regional scales, and chemical processes of dissolution, precipitation and diffusional solution transport. The compaction and distortional deformation of quartz aggregates exposed to reactive aqueous fluids have been investigated experimentally at varying critical and subcritical stress states and time scales. Pore fluid compositions and reaction rates during deformation have been measured and compared with creep rates. Relative contributions of mechanical and chemical processes to deformation and pore structure evolution have been evaluated using acoustic emission (AE) measurements and scanning electron microscope (SEM) observations. At the subcritical conditions investigated, creep rates and acoustic emission rates fit transient logarithmic creep laws. Based on AE and SEM observations, we conclude that intragranular cracking and grain rearrangement are the dominant strain mechanisms. Specimens show little evidence of stress-enhanced solution transfer. At long times under wet conditions, the dominant strain mechanism gradually shifts from critical cracking at grain contacts with high stress concentrations to fluid-assisted sub-critical cracking

  6. Reservoir characterization of Pennsylvanian sandstone reservoirs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, M.

    1995-02-01

    This final report summarizes the progress during the three years of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description; (ii) scale-up procedures; (iii) outcrop investigation. The first section describes the methods by which a reservoir can be described in three dimensions. The next step in reservoir description is to scale up reservoir properties for flow simulation. The second section addresses the issue of scale-up of reservoir properties once the spatial descriptions of properties are created. The last section describes the investigation of an outcrop.

  7. Thermogenic Wet Gas in Immature Caprock Sections: Leakage or Generation.

    Science.gov (United States)

    Abrakasa, Selegha; Beka, Francis; Ndukauba, Egesi

    2017-04-01

    Gas geochemistry, an aspect of Petroleum Geoscience is a growing science, various concepts has been used to evaluation potential source rock for shale gas while in conventional petroleum exploration similar concepts have been used to determine potential productive formation for liquid hydrocarbons. Prior to the present times, headspace gas data had been used to recognize by pass pays, serve as indicators of petroleum accumulations, evaluate maturity and productive capacity of corresponding formations, evaluate the maturity and source of gas accumulations. Integrating studies in bid to achieve high degree of accuracy, data on direct hydrocarbon indicators (DHIs) such as oil stains, oil shows and seeps have been employed. Currently popular among professionals is the use of gas clouds on seismic cross sections. In contemporary times, advancement in gas geochemistry has witnessed the application of concepts on headspace gas to expound the efficiency of petroleum caprocks whose major role is to foster accumulation and preservation. This enables extricating potential leakage mechanism via caprock reservoir interface and unravel its corresponding migrational pathways. In this study thermogenic wet gas has been used as a dependable tool for delineating caprock leakage by discriminating migrant from indigenous hydrocarbons in caprock rock sections overlying the reservoirs. The thermogenic gas profile in corroboration with the thermogenic signature and maturity data were used. Summary statistics indicates that 60% of the 50 wells studied has wet gas up to 500m above the reservoir-caprock interface and 10% of the leaking wells are fracture prone leakage.The amount of wet gas ranges of up to 200,000 ppm in the caprock sections, this indicates pervasive leakage. Log view plots were modelled using Schlumbergers' Techlog, while descriptive lithologies were modeled using Zetawares' genesis.

  8. Simulation of petroleum recovery in naturally fractured reservoirs: physical process representation

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, Hernani P.; Miranda Filho, Daniel N. de [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Schiozer, Denis J. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

    2012-07-01

    The naturally fractured reservoir recovery normally involves risk especially in intermediate to oil wet systems because of the simulations poor efficiency results under waterflood displacement. Double-porosity models are generally used in fractured reservoir simulation and have been implemented in the major commercial reservoir simulators. The physical processes acting in petroleum recovery are represented in double-porosity models by matrix-fracture transfer functions, therefore commercial simulators have their own implementations, and as a result different kinetics and final recoveries are attained. In this work, a double porosity simulator was built with Kazemi et al. (1976), Sabathier et al. (1998) and Lu et al. (2008) transfer function implementations and their recovery results have been compared using waterflood displacement in oil-wet or intermediate-wet systems. The results of transfer function comparisons have showed recovery improvements in oil-wet or intermediate-wet systems under different physical processes combination, particularly in fully discontinuous porous medium when concurrent imbibition takes place, coherent with Firoozabadi (2000) experimental results. Furthermore, the implemented transfer functions, related to a double-porosity model, have been compared to double-porosity commercial simulator model, as well a discrete fracture model with refined grid, showing differences between them. Waterflood can be an effective recovery method even in fully discontinuous media for oil-wet or intermediate-wet systems where concurrent imbibition takes place with high enough pressure gradients across the matrix blocks. (author)

  9. MIKROMITSETY- MIGRANTS IN MINGECHEVIR RESERVOIR

    Directory of Open Access Journals (Sweden)

    M. A. Salmanov

    2017-01-01

    Full Text Available Aim. It is hardly possible to predict the continued stability of the watercourse ecosystems without the study of biological characteristics and composition of organisms inhabiting them. In the last 35-40 years, environmental conditions of the Mingachevir reservoir are determined by the stationary anthropogenic pressure. It was found that such components of plankton as algae, bacteria and fungi play a leading role in the transformation and migration of pollutants. The role of the three groups of organisms is very important in maintaining the water quality by elimination of pollutants. Among the organisms inhabiting the Mingachevir Reservoir, micromycetes have not yet been studied. Therefore, the study of the species composition and seasonal dynamics, peculiarities of their growth and development in the environment with the presence of some of the pollutants should be considered to date.Methods. In order to determine the role of micromycetes-migrants in the mineralization of organic substrates, as an active participant of self-purification process, we used water samples from the bottom sediments as well as decaying and skeletonized stalks of cane, reeds, algae, macrophytes, exuvia of insects and fish remains submerged in water.Findings. For the first time, we obtained the data on the quality and quantity of microscopic mycelial fungi in freshwater bodies on the example of the Mingachevir water reservoir; we also studied the possibilities for oxygenating the autochthonous organic matter of allochthonous origin with micromycetes-migrants.Conclusions. It was found that the seasonal development of micromycetes-migrants within the Mingachevir reservoir is characterized by an increase in the number of species in the summer and a gradual reduction in species diversity in the fall. 

  10. Wettability measurement under high P-T conditions using X-ray imaging with application to the brine-supercritical CO2 system

    Science.gov (United States)

    Chaudhary, Kuldeep; Guiltinan, Eric J.; Cardenas, M. Bayani; Maisano, Jessica A.; Ketcham, Richard A.; Bennett, Philip C.

    2015-09-01

    We present a new method for measuring wettability or contact angle of minerals at reservoir pressure-temperature conditions using high-resolution X-ray computed tomography (HRXCT) and radiography. In this method, a capillary or a narrow slot is constructed from a mineral or a rock sample of interest wherein two fluids are allowed to form an interface that is imaged using X-rays. After some validation measurements at room pressure-temperature conditions, we illustrate this method by measuring the contact angle of CO2-brine on quartz, muscovite, shale, borosilicate glass, polytetrafluoroethylene (PTFE or Teflon), and polyether ether ketone (PEEK) surfaces at 60-71°C and 13.8-22.8 MPa. At reservoir conditions, PTFE and PEEK surfaces were found to be CO2-wet with contact angles of 140° and 127°, respectively. Quartz and muscovite were found to be water-wet with contact angles of 26° and 58°, respectively, under similar conditions. Borosilicate glass-air-brine at room conditions showed strong water-wet characteristics with a contact angle of 9°, whereas borosilicate glass-CO2-brine at 13.8 MPa and 60°C showed a decrease in its water-wetness with contact angle of 54°. This method provides a new application for X-ray imaging and an alternative to other methods.

  11. On the effects of adaptive reservoir operating rules in hydrological physically-based models

    Science.gov (United States)

    Giudici, Federico; Anghileri, Daniela; Castelletti, Andrea; Burlando, Paolo

    2017-04-01

    Recent years have seen a significant increase of the human influence on the natural systems both at the global and local scale. Accurately modeling the human component and its interaction with the natural environment is key to characterize the real system dynamics and anticipate future potential changes to the hydrological regimes. Modern distributed, physically-based hydrological models are able to describe hydrological processes with high level of detail and high spatiotemporal resolution. Yet, they lack in sophistication for the behavior component and human decisions are usually described by very simplistic rules, which might underperform in reproducing the catchment dynamics. In the case of water reservoir operators, these simplistic rules usually consist of target-level rule curves, which represent the average historical level trajectory. Whilst these rules can reasonably reproduce the average seasonal water volume shifts due to the reservoirs' operation, they cannot properly represent peculiar conditions, which influence the actual reservoirs' operation, e.g., variations in energy price or water demand, dry or wet meteorological conditions. Moreover, target-level rule curves are not suitable to explore the water system response to climate and socio economic changing contexts, because they assume a business-as-usual operation. In this work, we quantitatively assess how the inclusion of adaptive reservoirs' operating rules into physically-based hydrological models contribute to the proper representation of the hydrological regime at the catchment scale. In particular, we contrast target-level rule curves and detailed optimization-based behavioral models. We, first, perform the comparison on past observational records, showing that target-level rule curves underperform in representing the hydrological regime over multiple time scales (e.g., weekly, seasonal, inter-annual). Then, we compare how future hydrological changes are affected by the two modeling

  12. SEISMIC DETERMINATION OF RESERVOIR HETEROGENEITY; APPLICATION TO THE CHARACTERIZATION OF HEAVY OIL RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Matthias G. Imhof; James W. Castle

    2003-11-01

    The objective of the project is to examine how seismic and geologic data can be used to improve characterization of small-scale heterogeneity and their parameterization in reservoir models. The study is performed at West Coalinga Field in California. We continued our investigation on the nature of seismic reactions from heterogeneous reservoirs. We began testing our algorithm to infer parameters of object-based reservoir models from seismic data. We began integration of seismic and geologic data to determine the deterministic limits of conventional seismic data interpretation. Lastly, we began integration of seismic and geologic heterogeneity using stochastic models conditioned both on wireline and seismic data.

  13. Purification technology of low-level active water of the wet spent fuel storage from radiocesium with selective inorganic sorbent

    International Nuclear Information System (INIS)

    Rovny, S.I.; Logunov, M.V.; Skobtsov, A.S.; Pazdnikov, A.P.; Voroshilov, Yu.A.

    2003-01-01

    During operational process of the radiochemical production it is impossible to avoid formation of the considerable amount of liquid low-level solutions, activity of which is basically caused by Cs-137. At Mayak PA water of the wet storage for the spent fuel assemblies can be referred to solutions of the given type. Wet storage for the spent fuel assemblies of RT-1 plant is an artificial reservoir with capacity 25000 m 3 filled with desalted water. Cs-137 content in the pond water was (1.14-5.33)·10 4 Bq/l, that made ∼ 90 % of the total beta-activity. It is known that one of the most efficient methods of the low-level waste purification from Cs-137 is a sorption method with the use of inorganic sorbents. For determination of the most perspective sorbent type cesium-137 mass distribution factors were estimated with some artificial and natural materials. The obtained results are presented. For selection of the optimum sorbent type from the most perspective samples - ferrocyanides, phosphates, zeolites - full-scale dynamic laboratory tests were carried out with real water of the wet storage for spent fuel assemblies. Filtration rate in downward direction was maintained at about 20 column volumes per hour. During experimental-industrial tests it was stated that in the specified operational conditions the effective filter cycle on the sorbent NZhA achieves 100,000 column volumes that corresponds to the experimental data. The effective filter cycle with the Selex-CFN sorbent, manufactured at Mayak PA, makes not less than 350,000 column volumes of water. During 9 months of continuous work of the column about 50 Ci of Cs-137 was deposited in 65 l of sorbent, and radionuclide activity concentration in the wet storage water reduced 5 times that corresponds well to the calculated data. (authors)

  14. Water in chalk reservoirs: 'friend or foe?'

    International Nuclear Information System (INIS)

    Hjuler, Morten Leth

    2004-01-01

    Most of the petroleum fields in the Norwegian sector of the North Sea are sandstone reservoirs; the oil and gas are trapped in different species of sandstone. But the Ekofisk Field is a chalk reservoir, which really challenges the operator companies. When oil is produced from chalk reservoirs, water usually gets in and the reservoir subsides. The subsidence may be expensive for the oil companies or be used to advantage by increasing the recovery rate. Since 60 per cent of the world's petroleum reserves are located in carbonate reservoirs, it is important to understand what happens as oil and gas are pumped out. Comprehensive studies at the Department of Petroleum Technology and Applied Geophysics at Stavanger University College in Norway show that the mechanical properties of chalk are considerably altered when the pores in the rock become saturated with oil/gas or water under different stress conditions. The processes are extremely complex. The article also maintains that the effects of injecting carbon dioxide from gas power plants into petroleum reservoirs should be carefully studied before this is done extensively

  15. Mrica Reservoir Sedimentation: Current Situation and Future Necessary Management

    Directory of Open Access Journals (Sweden)

    Puji Utomo

    2017-09-01

    Full Text Available Mrica Reservoir is one of many reservoirs located in Central Java that experienced a considerably high sedimentation during the last ten years. This condition has caused a rapid decrease in reservoir capacity. Various countermeasures have been introduced to reduce the rate of the reservoir sedimentation through catchment management and reservoir operation by means of flushing and/or dredging. However, the sedimentation remains intensive so that the fulfillment of water demand for electrical power generation was seriously affected. This paper presents the results of evaluation on the dynamics of the purpose of this research is to evaluate the sediment balance of the Mrica Reservoir based on two different scenarios, i.e. the existing condition and another certain type of reservoir management. The study on sediment balance was carried out by estimating the sediment inflow applying sheet erosion method in combination with the analysis of sediment rating curve. The measurement of the deposited sediment rate in the reservoir was conducted through the periodic echo sounding, whereas identification of the number of sediment that has been released from the reservoir was carried out through the observation on both flushing and dredging activities. The results show that during the last decade, the rate of the sediment inflow was approximately 5.869 MCM/year, whereas the released sediment from the reservoir was 4.097 MCM/year. In order to maintain the reservoir capacity, therefore, at least 1.772 MCM/year should be released from the reservoir by means of either flushing or dredging. Sedimentation management may prolong the reservoir’s service life to exceed the design life. Without sediment management, the lifetime of the reservoir would have finished by 2016, whereas with the proper management the lifetime may be extended to 2025.

  16. Study of polycaprolactone wet electrospinning process

    Directory of Open Access Journals (Sweden)

    E. Kostakova

    2014-08-01

    Full Text Available Wet electrospinning is a useful method for 3-dimensional structure control of nanofibrous materials. This innovative technology uses a liquid collector instead of the metal one commonly used for standard electrospinning. The article compares the internal structural features of polycaprolactone (PCL nanofibrous materials prepared by both technologies. We analyze the influence of different water/ethanol compositions used as a liquid collector on the morphology of the resultant polycaprolactone nanofibrous materials. Scanning electron micro-photographs have revealed a bimodal structure in the wet electrospun materials composed of micro and nanofibers uniformly distributed across the sample bulk. We have shown that the full-faced, twofold fiber distribution is due to the solvent composition and is induced and enhanced by increasing the ethanol weight ratio. Moreover, the comparison of fibrous layers morphology obtained by wet and dry spinning have revealed that beads that frequently appeared in dry spun materials are created by Plateau-Rayleigh instability of the fraction of thicker fibers. Theoretical conditions for spontaneous and complete immersion of cylindrical fibers into a liquid collector are also derived here.

  17. Wetting of Water on Graphene

    KAUST Repository

    Bera, Bijoyendra

    2016-11-28

    The wetting properties of graphene have proven controversial and difficult to assess. The presence of a graphene layer on top of a substrate does not significantly change the wetting properties of the solid substrate, suggesting that a single graphene layer does not affect the adhesion between the wetting phase and the substrate. However, wetting experiments of water on graphene show contact angles that imply a large amount of adhesion. Here, we investigate the wetting of graphene by measuring the mass of water vapor adsorbing to graphene flakes of different thickness at different relative humidities. Our experiments unambiguously show that the thinnest of graphene flakes do not adsorb water, from which it follows that the contact angle of water on these flakes is ~180o. Thicker flakes of graphene nanopowder, on the other hand, do adsorb water. A calculation of the van der Waals (vdW) interactions that dominate the adsorption in this system confirms that the adhesive interactions between a single atomic layer of graphene and water are so weak that graphene is superhydrophobic. The observations are confirmed in an independent experiment on graphene-coated water droplets that shows that it is impossible to make liquid \\'marbles\\' with molecularly thin graphene.

  18. Using Biosurfactants Produced from Agriculture Process Waste Streams to Improve Oil Recovery in Fractured Carbonate Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Johnson; Mehdi Salehi; Karl Eisert; Sandra Fox

    2009-01-07

    surfactant concentrations. To reliably quantify both benchmark surfactants and surfactin, a surfactant ion-selective electrode was used as an indicator in the potentiometric titration of the anionic surfactants with Hyamine 1622. The wettability change mediated by dilute solutions of a commercial preparation of SLS (STEOL CS-330) and surfactin was assessed using two-phase separation, and water flotation techniques; and surfactant loss due to retention and adsorption on the rock was determined. Qualitative tests indicated that on a molar basis, surfactin is more effective than STEOL CS-330 in altering wettability of crushed Lansing-Kansas City carbonates from oil-wet to water-wet state. Adsorption isotherms of STEOL CS-330 and surfactin on crushed Lansing-Kansas City outcrop and reservoir material showed that surfactin has higher specific adsorption on these oomoldic carbonates. Amott wettability studies confirmed that cleaned cores are mixed-wet, and that the aging procedure renders them oil-wet. Tests of aged cores with no initial water saturation resulted in very little spontaneous oil production, suggesting that water-wet pathways into the matrix are required for wettability change to occur. Further investigation of spontaneous imbibition and forced imbibition of water and surfactant solutions into LKC cores under a variety of conditions--cleaned vs. crude oil-aged; oil saturated vs. initial water saturation; flooded with surfactant vs. not flooded--indicated that in water-wet or intermediate wet cores, sodium laureth sulfate is more effective at enhancing spontaneous imbibition through wettability change. However, in more oil-wet systems, surfactin at the same concentration performs significantly better.

  19. Climate variability and sedimentation of a hydropower reservoir

    International Nuclear Information System (INIS)

    Riedel, M.

    2008-01-01

    As part of the relicensing of a large Hydroelectric Project in the central Appalachians, large scale watershed and reservoir sedimentation models were developed to forecast potential sedimentation scenarios. The GIS based watershed model was spatially explicit and calibrated to long term observed data. Potential socio/economic development scenarios were used to construct future watershed land cover scenarios. Climatic variability and potential change analysis were used to identify future climate regimes and shifts in precipitation and temperature patterns. Permutations of these development and climate changes were forecasted over 50 years and used to develop sediment yield regimes to the project reservoir. Extensive field work and reservoir survey, including current and wave instrumentation, were used to characterize the project watershed, rivers and reservoir hydrodynamics. A fully 3 dimensional hydrodynamic reservoir sedimentation model was developed for the project and calibrated to observed data. Hydrologic and sedimentation results from watershed forecasting provided boundary conditions for reservoir inputs. The calibrated reservoir model was then used to forecast changes in reservoir sedimentation and storage capacity under different future climate scenarios. Results indicated unique zones of advancing sediment deltas and temporary storage areas. Forecasted changes in reservoir bathymetry and sedimentation patterns were also developed for the various climate change scenarios. The warmer and wetter scenario produced sedimentation impacts similar to extensive development under no climate change. The results of these analyses are being used to develop collaborative watershed and soil conservation partnerships to reduce future soil losses and reservoir sedimentation from projected development. (author)

  20. Functional age as an indicator of reservoir senescence

    Science.gov (United States)

    Miranda, Leandro E.; Krogman, R. M.

    2015-01-01

    It has been conjectured that reservoirs differ in the rate at which they manifest senescence, but no attempt has been made to find an indicator of senescence that performs better than chronological age. We assembled an indicator of functional age by creating a multimetric scale consisting of 10 metrics descriptive of reservoir environments that were expected to change directionally with reservoir senescence. In a sample of 1,022 U.S. reservoirs, chronological age was not correlated with functional age. Functional age was directly related to percentage of cultivated land in the catchment and inversely related to reservoir depth. Moreover, aspects of reservoir fishing quality and fish population characteristics were related to functional age. A multimetric scale to indicate reservoir functional age presents the possibility for management intervention from multiple angles. If a reservoir is functionally aging at an accelerated rate, action may be taken to remedy the conditions contributing most to functional age. Intervention to reduce scores of selected metrics in the scale can potentially reduce the rate of senescence and increase the life expectancy of the reservoir. This leads to the intriguing implication that steps can be taken to reduce functional age and actually make the reservoir grow younger.

  1. Optimising reservoir operation

    DEFF Research Database (Denmark)

    Ngo, Long le

    Anvendelse af optimeringsteknik til drift af reservoirer er blevet et væsentligt element i vandressource-planlægning og -forvaltning. Traditionelt har reservoirer været styret af heuristiske procedurer for udtag af vand, suppleret i en vis udstrækning af subjektive beslutninger. Udnyttelse af...... reservoirer involverer en lang række interessenter med meget forskellige formål (f.eks. kunstig vanding, vandkraft, vandforsyning mv.), og optimeringsteknik kan langt bedre lede frem til afbalancerede løsninger af de ofte modstridende interesser. Afhandlingen foreslår en række tiltag, hvormed traditionelle...... driftsstrategier kan erstattes af optimale strategier baseret på den nyeste udvikling indenfor computer-baserede beregninger. Hovedbidraget i afhandlingen er udviklingen af et beregningssystem, hvori en simuleringsmodel er koblet til en model for optimering af nogle udvalgte beslutningsvariable, der i særlig grad...

  2. Pelagic behaviour of reservoir fishes: sinusoidal swimming and associated behaviour

    OpenAIRE

    JAROLÍM, Oldřich

    2009-01-01

    Annotation Long-term fixed-location hydroacoustic study with uplooking transducer was performed during 2005 in Římov reservoir, Czech Republic. It dealt mainly with fish behaviour in the open water of reservoir, especially with sinusoidal swimming behaviour. The dependence of pelagic fish behaviour on environmental conditions was also studied.

  3. Geothermal reservoir engineering

    CERN Document Server

    Grant, Malcolm Alister

    2011-01-01

    As nations alike struggle to diversify and secure their power portfolios, geothermal energy, the essentially limitless heat emanating from the earth itself, is being harnessed at an unprecedented rate.  For the last 25 years, engineers around the world tasked with taming this raw power have used Geothermal Reservoir Engineering as both a training manual and a professional reference.  This long-awaited second edition of Geothermal Reservoir Engineering is a practical guide to the issues and tasks geothermal engineers encounter in the course of their daily jobs. The bo

  4. Session: Reservoir Technology

    Energy Technology Data Exchange (ETDEWEB)

    Renner, Joel L.; Bodvarsson, Gudmundur S.; Wannamaker, Philip E.; Horne, Roland N.; Shook, G. Michael

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five papers: ''Reservoir Technology'' by Joel L. Renner; ''LBL Research on the Geysers: Conceptual Models, Simulation and Monitoring Studies'' by Gudmundur S. Bodvarsson; ''Geothermal Geophysical Research in Electrical Methods at UURI'' by Philip E. Wannamaker; ''Optimizing Reinjection Strategy at Palinpinon, Philippines Based on Chloride Data'' by Roland N. Horne; ''TETRAD Reservoir Simulation'' by G. Michael Shook

  5. [Research progress on phosphorus budgets and regulations in reservoirs].

    Science.gov (United States)

    Shen, Xiao; Li, Xu; Zhang, Wang-shou

    2014-12-01

    Phosphorus is an important limiting factor of water eutrophication. A clear understanding of its budget and regulated method is fundamental for reservoir ecological health. In order to pro- mote systematic research further and improve phosphorus regulation system, the budget balance of reservoir phosphorus and its influencing factors were concluded, as well as conventional regulation and control measures. In general, the main phosphorus sources of reservoirs include upstream input, overland runoff, industrial and domestic wastewater, aquaculture, atmospheric deposition and sediment release. Upstream input is the largest phosphorus source among them. The principal output path of phosphorus is the flood discharge, the emission load of which is mainly influenced by drainage patterns. In addition, biological harvest also can export a fraction of phosphorus. There are some factors affecting the reservoir phosphorus balance, including reservoirs' function, hydrological conditions, physical and chemical properties of water, etc. Therefore, the phosphorus budgets of different reservoirs vary greatly, according to different seasons and regions. In order to reduce the phosphorus loading in reservoirs, some methods are carried out, including constructed wetlands, prefix reservoir, sediment dredging, biomanipulation, etc. Different methods need to be chosen and combined according to different reservoirs' characteristics and water quality management goals. Thus, in the future research, it is reasonable to highlight reservoir ecological characteristics and proceed to a complete and systematic analysis of the inherent complexity of phosphorus budget and its impact factors for the reservoirs' management. Besides, the interaction between phosphorus budget and other nutrients in reservoirs also needs to be conducted. It is fundamental to reduce the reservoirs' phosphorus loading to establish a scientific and improved management system based on those researches.

  6. An insight into the mechanism and evolution of shale reservoir characteristics with over-high maturity

    Directory of Open Access Journals (Sweden)

    Xinjing Li

    2016-10-01

    Full Text Available Over-high maturity is one of the most vital characteristics of marine organic-rich shale reservoirs from the Lower Paleozoic in the south part of China. The organic matter (OM in shale gas reservoirs almost went through the entire thermal evolution. During this wide span, a great amount of hydrocarbon was available and numerous pores were observed within the OM including kerogen and solid bitumen/pyrobitumen. These nanopores in solid bitumen/pyrobitumen can be identified using SEM. The imaging can be dissected and understood better based on the sequence of diagenesis and hydrocarbon charge with the shape of OM and pores. In terms of the maturity process showed by the various typical cases, the main effects of the relationship between the reservoir porosity and organic carbon abundance are interpreted as follows: the change and mechanism of reservoirs properties due to thermal evolution are explored, such as gas carbon isotope from partial to complete rollover zone, wettability alteration from water-wet to oil-wet and then water-wet pore surface again, electrical resistivity reversal from the increasing to decreasing stage, and nonlinearity fluctuation of rock elasticity anisotropy. These indicate a possible evolution pathway for shale gas reservoirs from the Lower Paleozoic in the southern China, as well as the general transformation processes between different shale reservoirs in thermal stages.

  7. Does Surface Roughness Amplify Wetting?

    Czech Academy of Sciences Publication Activity Database

    Malijevský, Alexandr

    2014-01-01

    Roč. 141, č. 18 (2014), s. 184703 ISSN 0021-9606 R&D Projects: GA ČR GA13-09914S Institutional support: RVO:67985858 Keywords : density functional theory * wetting * roughness Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.952, year: 2014

  8. unconventional natural gas reservoirs

    International Nuclear Information System (INIS)

    Correa G, Tomas F; Osorio, Nelson; Restrepo R, Dora P

    2009-01-01

    This work is an exploration about different unconventional gas reservoirs worldwide: coal bed methane, tight gas, shale gas and gas hydrate? describing aspects such as definition, reserves, production methods, environmental issues and economics. The overview also mentioned preliminary studies about these sources in Colombia.

  9. Parallel reservoir simulator computations

    International Nuclear Information System (INIS)

    Hemanth-Kumar, K.; Young, L.C.

    1995-01-01

    The adaptation of a reservoir simulator for parallel computations is described. The simulator was originally designed for vector processors. It performs approximately 99% of its calculations in vector/parallel mode and relative to scalar calculations it achieves speedups of 65 and 81 for black oil and EOS simulations, respectively on the CRAY C-90

  10. Coupling of two-phase flow in fractured-vuggy reservoir with filling medium

    Directory of Open Access Journals (Sweden)

    Xie Haojun

    2017-03-01

    Full Text Available Caves in fractured-vuggy reservoir usually contain lots of filling medium, so the two-phase flow in formations is the coupling of free flow and porous flow, and that usually leads to low oil recovery. Considering geological interpretation results, the physical filled cave models with different filling mediums are designed. Through physical experiment, the displacement mechanism between un-filled areas and the filling medium was studied. Based on the experiment model, we built a mathematical model of laminar two-phase coupling flow considering wettability of the porous media. The free fluid region was modeled using the Navier-Stokes and Cahn-Hilliard equations, and the two-phase flow in porous media used Darcy's theory. Extended BJS conditions were also applied at the coupling interface. The numerical simulation matched the experiment very well, so this numerical model can be used for two-phase flow in fracture-vuggy reservoir. In the simulations, fluid flow between inlet and outlet is free flow, so the pressure difference was relatively low compared with capillary pressure. In the process of water injection, the capillary resistance on the surface of oil-wet filling medium may hinder the oil-water gravity differentiation, leading to no fluid exchange on coupling interface and remaining oil in the filling medium. But for the water-wet filling medium, capillary force on the surface will coordinate with gravity. So it will lead to water imbibition and fluid exchange on the interface, high oil recovery will finally be reached at last.

  11. Mercury and methylmercury in reservoirs in Indiana

    Science.gov (United States)

    Risch, Martin R.; Fredericksen, Amanda L.

    2015-01-01

    Mercury (Hg) is an element that occurs naturally, but evidence suggests that human activities have resulted in increased amounts being released to the atmosphere and land surface. When Hg is converted to methylmercury (MeHg) in aquatic ecosystems, MeHg accumulates and increases in the food web so that some fish contain levels which pose a health risk to humans and wildlife that consume these fish. Reservoirs unlike natural lakes, are a part of river systems that are managed for flood control. Data compiled and interpreted for six flood-control reservoirs in Indiana showed a relation between Hg transport, MeHg formation in water, and MeHg in fish that was influenced by physical, chemical, and biological differences among the reservoirs. Existing information precludes a uniform comparison of Hg and MeHg in all reservoirs in the State, but factors and conditions were identified that can indicate where and when Hg and MeHg levels in reservoirs could be highest.

  12. Integral cesium reservoir: Design and transient operation

    Science.gov (United States)

    Smith, Joe N., Jr.; Horner, M. Harlan; Begg, Lester L.; Wrobleski, William J.

    An electrically heated thermionic converter has been designed built and successfully tested in air. One of the unique features of this converter was an integral cesium reservoir thermally coupled to the emitter. The reservoir consisted of fifteen cesiated graphite pins located in pockets situated in the emitter lead with thermal coupling to the emitter, collector and the emitter terminal; there were no auxiliary electric heaters on the reservoir. Test results are described for conditions in which the input thermal power to the converter was ramped up and down between 50% and 100% of full power in times as short as 50 sec, with data acquisition occurring every 12 sec. During the ramps the emitter and collector temperature profiles. the reservoir temperature and the electric output into a fixed load resistor are reported. The converter responded promptly to the power ramps without excessive overshoot and with no tendency to develop instabilities. This is the rust demonstration of the performance of a cesium-graphite integral reservoir in a fast transient.

  13. WETTABILITY AND PREDICTION OF OIL RECOVERY FROM RESERVOIRS DEVELOPED WITH MODERN DRILLING AND COMPLETION FLUIDS

    Energy Technology Data Exchange (ETDEWEB)

    Jill S. Buckley; Norman R. Morrow

    2006-01-01

    The objectives of this project are: (1) to improve understanding of the wettability alteration of mixed-wet rocks that results from contact with the components of synthetic oil-based drilling and completion fluids formulated to meet the needs of arctic drilling; (2) to investigate cleaning methods to reverse the wettability alteration of mixed-wet cores caused by contact with these SBM components; and (3) to develop new approaches to restoration of wetting that will permit the use of cores drilled with SBM formulations for valid studies of reservoir properties.

  14. SCREENING METHODS FOR SELECTION OF SURFACTANT FORMULATIONS FOR IOR FROM FRACTURED CARBONATE RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    William A. Goddard III; Yongchun Tang; Patrick Shuler; Mario Blanco; Yongfu Wu; Seung Soon Jang

    2005-07-01

    This topical report presents details of the laboratory work performed to complete Task 1 of this project; developing rapid screening methods to assess surfactant performance for IOR (Improved Oil Recovery) from fractured carbonate reservoirs. The desired outcome is to identify surfactant formulations that increase the rate and amount of aqueous phase imbibition into oil-rich, oil-wet carbonate reservoir rock. Changing the wettability from oil-wet to water-wet is one key to enhancing this water-phase imbibition process that in turn recovers additional oil from the matrix portion of a carbonate reservoir. The common laboratory test to evaluate candidate surfactant formulations is to measure directly the aqueous imbibition rate and oil recovery from small outcrop or reservoir cores, but this procedure typically requires several weeks. Two methods are presented here for the rapid screening of candidate surfactant formulations for their potential IOR performance in carbonate reservoirs. One promising surfactant screening protocol is based on the ability of a surfactant solution to remove aged crude oil that coats a clear calcite crystal (Iceland Spar). Good surfactant candidate solutions remove the most oil the quickest from the chips, plus change the apparent contact angle of the remaining oil droplets on the surface that thereby indicate increased water-wetting. The other fast surfactant screening method is based on the flotation behavior of powdered calcite in water. In this test protocol, first the calcite power is pre-treated to make the surface oil-wet. The next step is to add the pre-treated powder to a test tube and add a candidate aqueous surfactant formulation; the greater the percentage of the calcite that now sinks to the bottom rather than floats, the more effective the surfactant is in changing the solids to become now preferentially water-wet. Results from the screening test generally are consistent with surfactant performance reported in the literature.

  15. Thickness of residual wetting film in liquid-liquid displacement

    Science.gov (United States)

    Beresnev, Igor; Gaul, William; Vigil, R. Dennis

    2011-08-01

    Core-annular flow is common in nature, representing, for example, how streams of oil, surrounded by water, move in petroleum reservoirs. Oil, typically a nonwetting fluid, tends to occupy the middle (core) part of a channel, while water forms a surrounding wall-wetting film. What is the thickness of the wetting film? A classic theory has been in existence for nearly 50 years offering a solution, although in a controversial manner, for moving gas bubbles. On the other hand, an acceptable, experimentally verified theory for a body of one liquid flowing in another has not been available. Here we develop a hydrodynamic, testable theory providing an explicit relationship between the thickness of the wetting film and fluid properties for a blob of one fluid moving in another, with neither phase being gas. In its relationship to the capillary number Ca, the thickness of the film is predicted to be proportional to Ca2 at lower Ca and to level off at a constant value of ˜20% the channel radius at higher Ca. The thickness of the film is deduced to be approximately unaffected by the viscosity ratio of the fluids. We have conducted our own laboratory experiments and compiled experimental data from other studies, all of which are mutually consistent and confirm the salient features of the theory. At the same time, the classic law, originally deduced for films surrounding moving gas bubbles but often believed to hold for liquids as well, fails to explain the observations.

  16. APPLICATION OF INTEGRATED RESERVOIR MANAGEMENT AND RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Jack Bergeron; Tom Blasingame; Louis Doublet; Mohan Kelkar; George Freeman; Jeff Callard; David Moore; David Davies; Richard Vessell; Brian Pregger; Bill Dixon; Bryce Bezant

    2000-03-01

    Reservoir performance and characterization are vital parameters during the development phase of a project. Infill drilling of wells on a uniform spacing, without regard to characterization does not optimize development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, especially carbonate reservoirs. These reservoirs are typically characterized by: (1) large, discontinuous pay intervals; (2) vertical and lateral changes in reservoir properties; (3) low reservoir energy; (4) high residual oil saturation; and (5) low recovery efficiency. The operational problems they encounter in these types of reservoirs include: (1) poor or inadequate completions and stimulations; (2) early water breakthrough; (3) poor reservoir sweep efficiency in contacting oil throughout the reservoir as well as in the nearby well regions; (4) channeling of injected fluids due to preferential fracturing caused by excessive injection rates; and (5) limited data availability and poor data quality. Infill drilling operations only need target areas of the reservoir which will be economically successful. If the most productive areas of a reservoir can be accurately identified by combining the results of geological, petrophysical, reservoir performance, and pressure transient analyses, then this ''integrated'' approach can be used to optimize reservoir performance during secondary and tertiary recovery operations without resorting to ''blanket'' infill drilling methods. New and emerging technologies such as geostatistical modeling, rock typing, and rigorous decline type curve analysis can be used to quantify reservoir quality and the degree of interwell communication. These results can then be used to develop a 3-D simulation model for prediction of infill locations. The application of reservoir surveillance techniques to identify additional reservoir ''pay'' zones

  17. Analysis of the influence of reservoirs utilization to water quality profiles in Indonesia (Saguling - Jatiluhur) and Malaysia (Temengor - Chenderoh) with special references to cascade reservoirs

    Science.gov (United States)

    Subehi, Luki; Norasikin Ismail, Siti; Ridwansyah, Iwan; Hamid, Muzzalifah Abd; Mansor, Mashhor

    2018-02-01

    Tropical reservoir is the one ecosystem which is functioning in both ecological and economical services. As the settling of water volume, it harbors many species of fish. The objective of this study is to analyze the utilization and management of reservoirs related to their water quality conditions, represent by tropical reservoirs from Indonesia and Malaysia. Survey at Jatiluhur and Saguling (Indonesia) was conducted in March 2014 and September 2015, respectively while in Temengor and Chenderoh (Malaysia), the survey was done in January 2014 and April 2017, respectively. Based on elevation, Saguling and Temengor are upstream reservoirs. On the contrary, Jatiluhur and Chenderoh are downstream reservoirs. The results of the surveys in Jatiluhur and Saguling reservoirs showed that the average depths are 32.9m and 17.9m, respectively. On the other hand, Temengor and Chenderoh reservoirs are 100m and 16.2m, respectively. All of them play multi-functional roles including as a source of power plant, fisheries and tourism, as well as water sources for irrigation. In addition, Saguling and Temengor reservoirs are relatively dendritic in shape. In Indonesia, there are three consecutive reservoirs along Citarum River, whereas in Malaysia there are four consecutive reservoirs along Perak River. The results showed the potential impact of fish cages as pollutant, especially at Indonesian reservoirs. In addition, these tropical reservoirs have become famous tourism getaway. The capabilities of economic values of these reservoirs and ecosystem should be balanced. Basic ecological information is necessary for the next study.

  18. Predicting germination in semi-arid wildland seedbeds II. Field validation of wet thermal-time models

    Science.gov (United States)

    Jennifer K. Rawlins; Bruce A. Roundy; Dennis Eggett; Nathan. Cline

    2011-01-01

    Accurate prediction of germination for species used for semi-arid land revegetation would support selection of plant materials for specific climatic conditions and sites. Wet thermal-time models predict germination time by summing progress toward germination subpopulation percentages as a function of temperature across intermittent wet periods or within singular wet...

  19. Assessing fish assemblages similarity above and below a dam in a Neotropical reservoir with partial blockage

    Directory of Open Access Journals (Sweden)

    FG. Araújo

    Full Text Available Damming rivers disrupts the water flow and changes the ichthyofauna organisation. We investigated an impoundment with permanent connection and homogeneous environmental conditions between the zones above and below the dam. Temperature was comparatively higher during wet season irrespective of zone, and both zones had higher dissolved oxygen, conductivity and transparency in the dry season. A total of 1687 individuals comprising 27 species were collected in the downriver zone, while the reservoir had 879 individuals and 23 species. Each zone had different fish assemblage composition and structure, but assemblages were not explained by the examined environmental variables (r2 = 0.08; p = 0.307. Migratory species such as Pimelodus maculatus, Pimelodus fur, Leporinus copelandii and Prochilodus lineatus were the most affected, and probably are prevented to perform upriver migrations. On the other hand, lentic adapted species such as G. brasiliensis, Hoplias malabaricus and Hoplosternum littorale successfully colonised the reservoir. Therefore we conclude that the presence of the lateral hydrological connectivity alone does not guarantee the ecological connectivity since fish assemblage similarity differed between the two zones. Fish passage facilities should be monitored and managed to evaluate and improve their functionality.

  20. Kinetic effects in dynamic wetting

    Science.gov (United States)

    Sprittles, James

    2017-11-01

    The maximum speed at which a liquid can wet a solid is limited by the need to displace gas lubrication films in front of the moving contact line. The characteristic height of these films is often comparable to the mean free path in the gas so that hydrodynamic models do not adequately describe the flow physics. In this talk, I will develop a model which incorporates kinetic effects in the gas, via the Boltzmann equation, and can predict experimentally-observed increases in the maximum speed of wetting when (a) the liquid's viscosity is varied, (b) the ambient gas pressure is reduced or (c) the meniscus is confined. This work was supported by the Leverhulme Trust (Research Project Grant) and the Engineering & Physical Sciences Research Council (Grant EP/N016602/1).

  1. Formative Assessment Probes: Wet Jeans

    Science.gov (United States)

    Keeley, Page

    2015-01-01

    Picture a wet towel or a puddle of water on a hot, sunny day. An hour later, the towel is dry and the puddle no longer exists. What happened to the water? Where did it go? These are questions that reveal myriad interesting student ideas about evaporation and the water cycle--ideas that provide teachers with a treasure trove of data they can use to…

  2. Wet water glass production plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant of a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997. and 1998, increasing detergent zeolite production, from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. The main goal was increasing the detergent zeolite production. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution (except for the filter cake. The wet water glass production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start - up, and repairs. By installing additional process equipment (centrifugal pumps and heat exchangers technological bottlenecks were overcome, and by adjusting the operation of autoclaves, and water glass filters and also by optimizing the capacities of process equipment.

  3. Contact line motion over heated substrates with spatially nonuniform wetting properties

    Science.gov (United States)

    Ajaev, V. S.; Gatapova, E. Ya

    2017-11-01

    We develop mathematical models of moving contact lines over flat heated solid surfaces with spatial variation of wetting properties under the conditions when evaporation is significant. The gas phase is assumed to be pure vapor and a lubrication-type framework is employed for describing viscous flow in the liquid. Substrate wetting properties are modeled through disjoining pressure, with the main focus on how the contact line motion changes near the regions of localized spatial variation of wetting properties.

  4. Numerical study on over reading coefficient in wet steam flow measurement

    International Nuclear Information System (INIS)

    Bai Xuesong; Yuan Dewen; Yan Xiao; Peng Xingjian

    2013-01-01

    This paper investigated the flow process of wet steam in Venturi under interested conditions with CFD simulation software. The effect of pressure, mass flow rate, throat radius on over reading factor was analyzed. This paper aims to improve the wet steam over reading model and the prediction accuracy in wet steam. The results prove that the mass flow has a small effect on over reading coefficient, while the effect that throat radius has on over reading coefficient increases as the pressure rises. (authors)

  5. Work reservoirs in thermodynamics

    Science.gov (United States)

    Anacleto, Joaquim

    2010-05-01

    We stress the usefulness of the work reservoir in the formalism of thermodynamics, in particular in the context of the first law. To elucidate its usefulness, the formalism is then applied to the Joule expansion and other peculiar and instructive experimental situations, clarifying the concepts of configuration and dissipative work. The ideas and discussions presented in this study are primarily intended for undergraduate students, but they might also be useful to graduate students, researchers and teachers.

  6. Characterizing the Water Balance of the Sooke Reservoir, British Columbia over the Last Century

    Directory of Open Access Journals (Sweden)

    Arelia T. Werner

    2015-03-01

    Full Text Available Infrastructure such as dams and reservoirs are critical water-supply features in several regions of the world. However, ongoing population growth, increased demand and climate variability/change necessitate the better understanding of these systems, particularly in terms of their long-term trends. The Sooke Reservoir (SR of British Columbia, Canada is one such reservoir that currently supplies water to ~300,000 people, and is subject to considerable inter and intra-annual climatic variations. The main objectives of this study are to better understand the characteristics of the SR through an in-depth assessment of the contemporary water balance when the basin was intensively monitored (1996–2005, to use standardized runoff to select the best timescale to compute the Standard Precipitation (SPI and Standard Precipitation Evaporation Indices (SPEI to estimate trends in water availability over 1919 to 2005. Estimates of runoff and evaporation were validated by comparing simulated change in storage, computed by adding inputs and subtracting outputs from the known water levels by month, to observed change in storage. Water balance closure was within ±11% of the monthly change in storage on average when excluding months with spill pre-2002. The highest evaporation, dry season (1998 and lowest precipitation, wet season (2000/2001 from the intensively monitored period were used to construct a worst-case scenario to determine the resilience of the SR to drought. Under such conditions, the SR could support Greater Victoria until the start of the third wet season. The SPEI and SPI computed on a three-month timescale had the highest correlation with the standardized runoff, R2 equaled 0.93 and 0.90, respectively. A trend toward drier conditions was shown by SPEI over 1919 to 2005, while moistening over the same period was shown by SPI, although trends were small in magnitude. This study contributes a validated application of SPI and SPEI, giving more

  7. Numerical Simulation of Two Dimensional Flows in Yazidang Reservoir

    Science.gov (United States)

    Huang, Lingxiao; Liu, Libo; Sun, Xuehong; Zheng, Lanxiang; Jing, Hefang; Zhang, Xuande; Li, Chunguang

    2018-01-01

    This paper studied the problem of water flow in the Yazid Ang reservoir. It built 2-D RNG turbulent model, rated the boundary conditions, used the finite volume method to discrete equations and divided the grid by the advancing-front method. It simulated the two conditions of reservoir flow field, compared the average vertical velocity of the simulated value and the measured value nearby the water inlet and the water intake. The results showed that the mathematical model could be applied to the similar industrial water reservoir.

  8. Microbial quality and phylogenetic diversity of fresh rainwater and tropical freshwater reservoir.

    Science.gov (United States)

    Kaushik, Rajni; Balasubramanian, Rajasekhar; Dunstan, Hugh

    2014-01-01

    The impact of rainwater on the microbial quality of a tropical freshwater reservoir through atmospheric wet deposition of microorganisms was studied for the first time. Reservoir water samples were collected at four different sampling points and rainwater samples were collected in the immediate vicinity of the reservoir sites for a period of four months (January to April, 2012) during the Northeast monsoon period. Microbial quality of all fresh rainwater and reservoir water samples was assessed based on the counts for the microbial indicators: Escherichia coli (E. coli), total coliforms, and Enterococci along with total heterotrophic plate counts (HPC). The taxonomic richness and phylogenetic relationship of the freshwater reservoir with those of the fresh rainwater were also assessed using 16 S rRNA gene clone library construction. The levels of E. coli were found to be in the range of 0 CFU/100 mL-75 CFU/100 mL for the rainwater, and were 10-94 CFU/100 mL for the reservoir water. The sampling sites that were influenced by highway traffic emissions showed the maximum counts for all the bacterial indicators assessed. There was no significant increase in the bacterial abundances observed in the reservoir water immediately following rainfall. However, the composite fresh rainwater and reservoir water samples exhibited broad phylogenetic diversity, including sequences representing Betaproteobacteria, Alphaproteobacteria, Gammaproteobacteria, Actinobacteria, Lentisphaerae and Bacteriodetes. Members of the Betaproteobacteria group were the most dominant in both fresh rainwater and reservoir water, followed by Alphaproteobacteria, Sphingobacteria, Actinobacteria and Gammaproteobacteria.

  9. Advantageous Reservoir Characterization Technology in Extra Low Permeability Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Yutian Luo

    2017-01-01

    Full Text Available This paper took extra low permeability reservoirs in Dagang Liujianfang Oilfield as an example and analyzed different types of microscopic pore structures by SEM, casting thin sections fluorescence microscope, and so on. With adoption of rate-controlled mercury penetration, NMR, and some other advanced techniques, based on evaluation parameters, namely, throat radius, volume percentage of mobile fluid, start-up pressure gradient, and clay content, the classification and assessment method of extra low permeability reservoirs was improved and the parameter boundaries of the advantageous reservoirs were established. The physical properties of reservoirs with different depth are different. Clay mineral variation range is 7.0%, and throat radius variation range is 1.81 μm, and start pressure gradient range is 0.23 MPa/m, and movable fluid percentage change range is 17.4%. The class IV reservoirs account for 9.56%, class II reservoirs account for 12.16%, and class III reservoirs account for 78.29%. According to the comparison of different development methods, class II reservoir is most suitable for waterflooding development, and class IV reservoir is most suitable for gas injection development. Taking into account the gas injection in the upper section of the reservoir, the next section of water injection development will achieve the best results.

  10. European wet deposition maps based on measurements

    NARCIS (Netherlands)

    Leeuwen EP van; Erisman JW; Draaijers GPJ; Potma CJM; Pul WAJ van; LLO

    1995-01-01

    To date, wet deposition maps on a European scale have been based on long-range transport model results. For most components wet deposition maps based on measurements are only available on national scales. Wet deposition maps of acidifying components and base cations based on measurements are needed

  11. Modeling Reservoir-River Networks in Support of Optimizing Seasonal-Scale Reservoir Operations

    Science.gov (United States)

    Villa, D. L.; Lowry, T. S.; Bier, A.; Barco, J.; Sun, A.

    2011-12-01

    HydroSCOPE (Hydropower Seasonal Concurrent Optimization of Power and the Environment) is a seasonal time-scale tool for scenario analysis and optimization of reservoir-river networks. Developed in MATLAB, HydroSCOPE is an object-oriented model that simulates basin-scale dynamics with an objective of optimizing reservoir operations to maximize revenue from power generation, reliability in the water supply, environmental performance, and flood control. HydroSCOPE is part of a larger toolset that is being developed through a Department of Energy multi-laboratory project. This project's goal is to provide conventional hydropower decision makers with better information to execute their day-ahead and seasonal operations and planning activities by integrating water balance and operational dynamics across a wide range of spatial and temporal scales. This presentation details the modeling approach and functionality of HydroSCOPE. HydroSCOPE consists of a river-reservoir network model and an optimization routine. The river-reservoir network model simulates the heat and water balance of river-reservoir networks for time-scales up to one year. The optimization routine software, DAKOTA (Design Analysis Kit for Optimization and Terascale Applications - dakota.sandia.gov), is seamlessly linked to the network model and is used to optimize daily volumetric releases from the reservoirs to best meet a set of user-defined constraints, such as maximizing revenue while minimizing environmental violations. The network model uses 1-D approximations for both the reservoirs and river reaches and is able to account for surface and sediment heat exchange as well as ice dynamics for both models. The reservoir model also accounts for inflow, density, and withdrawal zone mixing, and diffusive heat exchange. Routing for the river reaches is accomplished using a modified Muskingum-Cunge approach that automatically calculates the internal timestep and sub-reach lengths to match the conditions of

  12. Effects of wet torrefaction on the physicochemical properties and pyrolysis product properties of rice husk

    International Nuclear Information System (INIS)

    Zhang, Shuping; Chen, Tao; Xiong, Yuanquan; Dong, Qing

    2017-01-01

    Highlights: • Wet torrefaction of rice husk prior to pyrolysis was applied. • Wet torrefaction has the dual advantages of dry torrefaction and demineralisation. • Wet torrefaction at the mild reaction condition promoted the production of bio-oil. • Biochar produced can be used as the feedstock for preparation of nanosilica. - Abstract: Wet torrefaction in the temperature range from 150 to 240 °C for 60 min was applied on rice husk sample prior to pyrolysis process in this work. Its effects on the physicochemical properties and pyrolysis product properties were evaluated. The analysis results of physicochemical properties of raw and pretreated samples indicated that wet torrefaction not only improved the fuel characteristics but also removed a large amount of alkali and alkaline earth metal species with the dual advantages of dry torrefaction and demineralisation. On the basis of pyrolysis experiment results, it was found that wet torrefaction at the mild reaction condition had a positive impact on bio-oil production, but more severe wet torrefaction condition was not reasonable. The highest relative content of levoglucosan (57.2%) was obtained from pyrolysis of rice husk sample after wet torrefaction at 210 °C, which was about 6.2 times higher than that of raw rice husk. The results of biochar analysis suggested that biochar produced from sample after wet torrefaction and pyrolysis seems not a desirable solid fuel, it can be used as the feedstock for preparation of nanosilica.

  13. Enhanced wet air oxidation : synergistic rate acceleration upon effluent recirculation

    Science.gov (United States)

    Matthew J. Birchmeier; Charles G. Hill; Carl J. Houtman; Rajai H. Atalla; Ira A. Weinstock

    2000-01-01

    Wet air oxidation (WAO) reactions of cellobiose, phenol, and syringic acid were carried out under mild conditions (155°C; 0.93MPa 02; soluble catalyst, Na5[PV2Mo10O40]). Initial oxidation rates were rapid but decreased to small values as less reactive oxidation products accumulated. Recalcitrant oxidation products were consumed more rapidly, however, if additional...

  14. Energy and exergy analysis of counter flow wet cooling towers

    Directory of Open Access Journals (Sweden)

    Saravanan Mani

    2008-01-01

    Full Text Available Cooling tower is an open system direct contact heat exchanger, where it cools water by both convection and evaporation. In this paper, a mathematical model based on heat and mass transfer principle is developed to find the outlet condition of water and air. The model is solved using iterative method. Energy and exergy analysis infers that inlet air wet bulb temperature is found to be the most important parameter than inlet water temperature and also variation in dead state properties does not affect the performance of wet cooling tower. .

  15. Radiocesium dynamics in herons inhabiting a contaminated reservoir system

    International Nuclear Information System (INIS)

    Dombey, A.H.; Paine, D.; McFarlane, R.W.

    1977-01-01

    The little blue heron (Florida caerulea) and the green heron (Butorides virescens) nest at a radionuclide-contaminated reservoir on the Savannah River Plant near Aiken, South Carolina. Green herons distributed their nests singly along the periphery of the reservoir but fed their nestlings exclusively upon amphibians collected from adjacent uncontaminated Carolina bays. Radiocesium burdens in green heron nestlings did not exceed 5 pCi/g wet wt. and 12 regurgitated food pellets averaged 0.2 pCi/g. Twelve pairs of little blue herons established a heronry upon a small island and fed their nestlings fish and amphibians foraged from within the differentially radionuclide-contaminated reservoir system. Nestlings within the same nest did not exhibit significant differences in body burdens, and the maximum radiocesium burden determined was 27.4 pCi/g wet wt. Substantial differences were found between nestlings from different nests however. The radiocesium level of 43 regurgitated food pellets had a high correlation with observed levels in the nestlings, and variation in food contamination is believed to be the major contributor in the observed variation in the nestlings. The variable contamination of primary prey species was correlated with the differentially contaminated foraging sites and indicates that adult little blue herons tended to spatially partition the available foraging areas. (author)

  16. Wet season range fidelity in a tropical migratory ungulate.

    Science.gov (United States)

    Morrison, Thomas A; Bolger, Douglas T

    2012-05-01

    1. In migratory populations, the degree of fidelity and dispersal among seasonal ranges is an important population process with consequences for demography, management, sensitivity to habitat change and adaptation to local environmental conditions. 2. Characterizing patterns of range fidelity in ungulates, however, has remained challenging because of the difficulties of following large numbers of marked individuals across multiple migratory cycles and of identifying the appropriate scale of analysis. 3. We examined fidelity to wet season (i.e. breeding) ranges in a recently declining population of wildebeest Connochaetes taurinus Burchell in northern Tanzania across 3 years. We used computer-assisted photographic identification and capture-recapture to characterize return patterns to three wet season ranges that were ecologically discrete and topographically isolated from one another. 4. Among 2557 uniquely identified adult wildebeest, we observed 150 recaptures across consecutive wet seasons. Between the two migratory subpopulations, the probability of remaining faithful to wet season areas ranged between 0·82 and 1·00. Animals from a non-migratory segment of the population (near Lake Manyara National Park) were rarely observed in other wet season ranges, despite proximity to one of the migratory pathways. 5. We found no effect of sex on an individuals' probability of switching wet season ranges. However, the breeding status of females in year i had a strong influence on patterns of range selection in year i + 1, with surviving breeders over three times as likely to switch ranges as non-breeders. 6. Social-group associations between pairs of recaptured animals were random with respect to an individual's wet season range during the previous or forthcoming wet seasons, suggesting that an individual's herd identity during the dry season does not predict wet season range selection. 7. Examining fidelity and dispersal in terrestrial migrations improves

  17. Effective stress coefficient for uniaxial strain condition

    DEFF Research Database (Denmark)

    Alam, M.M.; Fabricius, I.L.

    2012-01-01

    one dimensional rock mechanical deformation. We further investigated the effect of boundary condition on the stress dependency of effective stress coefficient and discussed its application in reservoir study. As stress field in the reservoirs are most unlikely to be hydrostatic, effective stress...... determined under uniaxial strain condition will be more relevant in reservoir studies. Copyright 2012 ARMA, American Rock Mechanics Association....

  18. The Coupling Effect of Rainfall and Reservoir Water Level Decline on the Baijiabao Landslide in the Three Gorges Reservoir Area, China

    Directory of Open Access Journals (Sweden)

    Nenghao Zhao

    2017-01-01

    Full Text Available Rainfall and reservoir level fluctuation are two of the main factors contributing to reservoir landslides. However, in China’s Three Gorges Reservoir Area, when the reservoir water level fluctuates significantly, it comes at a time of abundant rainfall, which makes it difficult to distinguish which factor dominates the deformation of the landslide. This study focuses on how rainfall and reservoir water level decline affect the seepage and displacement field of Baijiabao landslide spatially and temporally during drawdown of reservoir water level in the Three Gorges Reservoir Area, thus exploring its movement mechanism. The monitoring data of the landslide in the past 10 years were analyzed, and the correlation between rainfall, reservoir water level decline, and landslide displacement was clarified. By the numerical simulation method, the deformation evolution mechanism of this landslide during drawdown of reservoir water level was revealed, respectively, under three conditions, namely, rainfall, reservoir water level decline, and coupling of the above two conditions. The results showed that the deformation of the Baijiabao landslide was the coupling effect of rainfall and reservoir water level decline, while the latter effect is more pronounced.

  19. WET SOLIDS FLOW ENHANCEMENT; SEMIANNUAL

    International Nuclear Information System (INIS)

    Hugo S. Caram; Natalie Foster

    1997-01-01

    The objective was to visualize the flow of granular materials in flat bottomed silo. This was done by for dry materials introducing mustard seeds and poppy seeds as tracer particles and imaging them using Nuclear Magnetic Resonance. The region sampled was a cylinder 25 mm in diameter and 40 mm in length. Eight slices containing 128*128 to 256*256 pixels were generated for each image. The size of the silo was limited by the size of the high resolution NMR imager available. Cross-sections of 150mm flat bottomed silos, with the tracer layers immobilized by a gel, showed similar qualitative patterns for both dry and wet granular solids

  20. Reservoir and injection technology and Heat Extraction Project

    Energy Technology Data Exchange (ETDEWEB)

    Horne, R.N.; Ramey, H.H. Jr.; Miller, F.G.; Brigham, W.E.; Kruger, P.

    1989-12-31

    For the Stanford Geothermal Program in the fiscal year 1989, the task areas include predictive modeling of reservoir behavior and tracer test interpretation and testing. Major emphasis is in reservoir technology, reinjection technology, and heat extraction. Predictive modeling of reservoir behavior consists of a multi-pronged approach to well test analysis under a variety of conditions. The efforts have been directed to designing and analyzing well tests in (1) naturally fractured reservoirs; (2) fractured wells; (3) complex reservoir geometries; and, (4) gas reservoirs including inertial and other effects. The analytical solutions for naturally fractured reservoirs are determined using fracture size distribution. In the study of fractured wells, an elliptical coordinate system is used to obtain semi-analytical solutions to finite conductivity fractures. Effort has also been directed to the modeling and creation of a user friendly computer program for steam/gas reservoirs including wellbore storage, skin and non-Darcy flow effects. This work has a complementary effort on modeling high flow rate wells including inertial effects in the wellbore and fractures. In addition, work on gravity drainage systems is being continued.

  1. Interpreting isotopic analyses of microbial sulfate reduction in oil reservoirs

    Science.gov (United States)

    Hubbard, C. G.; Engelbrektson, A. L.; Druhan, J. L.; Cheng, Y.; Li, L.; Ajo Franklin, J. B.; Coates, J. D.; Conrad, M. E.

    2013-12-01

    Microbial sulfate reduction in oil reservoirs is often associated with secondary production of oil where seawater (28 mM sulfate) is commonly injected to maintain reservoir pressure and displace oil. The hydrogen sulfide produced can cause a suite of operating problems including corrosion of infrastructure, health exposure risks and additional processing costs. We propose that monitoring of the sulfur and oxygen isotopes of sulfate can be used as early indicators that microbial sulfate reduction is occurring, as this process is well known to cause substantial isotopic fractionation. This approach relies on the idea that reactions with reservoir (iron) minerals can remove dissolved sulfide, thereby delaying the transport of the sulfide through the reservoir relative to the sulfate in the injected water. Changes in the sulfate isotopes due to microbial sulfate reduction may therefore be measurable in the produced water before sulfide is detected. However, turning this approach into a predictive tool requires (i) an understanding of appropriate fractionation factors for oil reservoirs, (ii) incorporation of isotopic data into reservoir flow and reactive transport models. We present here the results of preliminary batch experiments aimed at determining fractionation factors using relevant electron donors (e.g. crude oil and volatile fatty acids), reservoir microbial communities and reservoir environmental conditions (pressure, temperature). We further explore modeling options for integrating isotope data and discuss whether single fractionation factors are appropriate to model complex environments with dynamic hydrology, geochemistry, temperature and microbiology gradients.

  2. Geothermal reservoir management

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, C.R.; Golabi, K.

    1978-02-01

    The optimal management of a hot water geothermal reservoir was considered. The physical system investigated includes a three-dimensional aquifer from which hot water is pumped and circulated through a heat exchanger. Heat removed from the geothermal fluid is transferred to a building complex or other facility for space heating. After passing through the heat exchanger, the (now cooled) geothermal fluid is reinjected into the aquifer. This cools the reservoir at a rate predicted by an expression relating pumping rate, time, and production hole temperature. The economic model proposed in the study maximizes discounted value of energy transferred across the heat exchanger minus the discounted cost of wells, equipment, and pumping energy. The real value of energy is assumed to increase at r percent per year. A major decision variable is the production or pumping rate (which is constant over the project life). Other decision variables in this optimization are production timing, reinjection temperature, and the economic life of the reservoir at the selected pumping rate. Results show that waiting time to production and production life increases as r increases and decreases as the discount rate increases. Production rate decreases as r increases and increases as the discount rate increases. The optimal injection temperature is very close to the temperature of the steam produced on the other side of the heat exchanger, and is virtually independent of r and the discount rate. Sensitivity of the decision variables to geohydrological parameters was also investigated. Initial aquifer temperature and permeability have a major influence on these variables, although aquifer porosity is of less importance. A penalty was considered for production delay after the lease is granted.

  3. A review of monitoring methods for pharmaceutical wet granulation.

    Science.gov (United States)

    Hansuld, E M; Briens, L

    2014-09-10

    High-shear wet granulation is commonly used in the pharmaceutical industry to improve powder properties for downstream processes such as tabletting. Granule growth, however, is difficult to predict because the process is sensitive to raw material properties and operating conditions. Development of process analytical technologies is encouraged by regulatory bodies to improve process understanding and monitor quality online. The primary technologies investigated for high-shear wet granulation monitoring include power consumption, near-infrared spectroscopy, Raman spectroscopy, capacitance measurements, microwave measurements, imaging, focused beam reflectance measurements, spatial filter velocimetry, stress and vibration measurements, as well as acoustic emissions. This review summarizes relevant research related to each of these technologies and discusses the challenges associated with each approach as a possible process analytical technology tool for high-shear wet granulation. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Advances in photonic reservoir computing

    Science.gov (United States)

    Van der Sande, Guy; Brunner, Daniel; Soriano, Miguel C.

    2017-05-01

    We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir's complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  5. Textile UWB Antenna Bending and Wet Performances

    Directory of Open Access Journals (Sweden)

    Mai A. R. Osman

    2012-01-01

    Full Text Available The vision and ideas of wearable computing systems describe future electronic systems as an integral part of our everyday clothing that provides the wearer with such intelligent personal assistants. Recently, there has been growing interest in the antenna community to merge between wearable systems technology, ultrawideband (UWB technology and textile technology. This work aimed to make closer steps towards real wearability by investigating the possibilities of designing wearable UWB antenna where textile materials are used for the substrate as well as the conducting parts of the designed antenna. Two types of conducting materials have been used for conducting parts, while a nonconducting fabric has been used as antenna substrate material. A set of comparative results of the proposed design were presented and discussed. Moreover, effects on the return loss by means of measurements for each fabricated antenna prototype under bent and fully wet conditions were discussed in more details.

  6. Reservoir characteristics and control factors of Carboniferous volcanic gas reservoirs in the Dixi area of Junggar Basin, China

    Directory of Open Access Journals (Sweden)

    Ji'an Shi

    2017-02-01

    volcanic breccia reservoir more easily leached by fresh water or groundwater, leading to secondary erosion pores. Volcanic rock weathering obviously has control on reservoir properties, and while the thickness of the weathering crust is 200–300 m, the properties of volcanic rock reservoir are the best. This is attributed mainly to the period during and after the volcano eruption, in which tectonism made the brittle volcanic rock develop a large number of fractures and micro cracks. This has led to the increased permeability of volcanic rock reservoir, the weathering and leaching effect of volcanic rock diagenetic late phase (which also formed lots of secondary pores, and greatly improved reservoir conditions. The overlying Permian Wutonggou formation mudstone provided high-quality cap rock for oil and gas accumulation.

  7. Elucidating the mysteries of wetting.

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Edmund Blackburn, III (,; ); Bourdon, Christopher Jay; Grillet, Anne Mary; Sackinger, Philip A.; Grest, Gary Stephen; Emerson, John Allen; Ash, Benjamin Jesse; Heine, David R.; Brooks, Carlton, F.; Gorby, Allen D.

    2005-11-01

    Nearly every manufacturing and many technologies central to Sandia's business involve physical processes controlled by interfacial wetting. Interfacial forces, e.g. conjoining/disjoining pressure, electrostatics, and capillary condensation, are ubiquitous and can surpass and even dominate bulk inertial or viscous effects on a continuum level. Moreover, the statics and dynamics of three-phase contact lines exhibit a wide range of complex behavior, such as contact angle hysteresis due to surface roughness, surface reaction, or compositional heterogeneities. These thermodynamically and kinetically driven interactions are essential to the development of new materials and processes. A detailed understanding was developed for the factors controlling wettability in multicomponent systems from computational modeling tools, and experimental diagnostics for systems, and processes dominated by interfacial effects. Wettability probed by dynamic advancing and receding contact angle measurements, ellipsometry, and direct determination of the capillary and disjoining forces. Molecular scale experiments determined the relationships between the fundamental interactions between molecular species and with the substrate. Atomistic simulations studied the equilibrium concentration profiles near the solid and vapor interfaces and tested the basic assumptions used in the continuum approaches. These simulations provide guidance in developing constitutive equations, which more accurately take into account the effects of surface induced phase separation and concentration gradients near the three-phase contact line. The development of these accurate models for dynamic multicomponent wetting allows improvement in science based engineering of manufacturing processes previously developed through costly trial and error by varying material formulation and geometry modification.

  8. Anaerobic hydrocarbon biodegradation in deep subsurface oil reservoirs.

    Science.gov (United States)

    Aitken, Carolyn M; Jones, D M; Larter, S R

    2004-09-16

    Biodegradation of crude oil in subsurface petroleum reservoirs is an important alteration process with major economic consequences. Aerobic degradation of petroleum hydrocarbons at the surface is well documented and it has long been thought that the flow of oxygen- and nutrient-bearing meteoric waters into reservoirs was necessary for in-reservoir petroleum biodegradation. The occurrence of biodegraded oils in reservoirs where aerobic conditions are unlikely, together with the identification of several anaerobic microorganisms in oil fields and the discovery of anaerobic hydrocarbon biodegradation mechanisms, suggests that anaerobic degradation processes could also be responsible. The extent of anaerobic hydrocarbon degradation processes in the world's deep petroleum reservoirs, however, remains strongly contested. Moreover, no organism has yet been isolated that has been shown to degrade hydrocarbons under the conditions found in deep petroleum reservoirs. Here we report the isolation of metabolites indicative of anaerobic hydrocarbon degradation from a large fraction of 77 degraded oil samples from both marine and lacustrine sources from around the world, including the volumetrically important Canadian tar sands. Our results therefore suggest that anaerobic hydrocarbon degradation is a common process in biodegraded subsurface oil reservoirs.

  9. Nuclear stimulation of oil-reservoirs

    International Nuclear Information System (INIS)

    Delort, F.; Supiot, F.

    1970-01-01

    Underground nuclear explosions in the Hoggar nuclear test site have shown that the geological effects may increase the production of oil or gas reservoirs. By studying the permanent liquid flow-rate with approximate DUPUIT's equation, or with a computer code, it is shown that the conventional well flow-rate may be increased by a factor between 3 and 50, depending on the medium and explosion conditions. (author)

  10. Modeling reservoir geomechanics using discrete element method : Application to reservoir monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Alassi, Haitham Tayseer

    2008-09-15

    Understanding reservoir geomechanical behavior is becoming more and more important for the petroleum industry. Reservoir compaction, which may result in surface subsidence and fault reactivation, occurs during reservoir depletion. Stress changes and possible fracture development inside and outside a depleting reservoir can be monitored using time-lapse (so-called '4D') seismic and/or passive seismic, and this can give valuable information about the conditions of a given reservoir during production. In this study we will focus on using the (particle-based) Discrete Element Method (DEM) to model reservoir geomechanical behavior during depletion and fluid injection. We show in this study that DEM can be used in modeling reservoir geomechanical behavior by comparing results obtained from DEM to those obtained from analytical solutions. The match of the displacement field between DEM and the analytical solution is good, however there is mismatch of the stress field which is related to the way stress is measured in DEM. A good match is however obtained by measuring the stress field carefully. We also use DEM to model reservoir geomechanical behavior beyond the elasticity limit where fractures can develop and faults can reactivate. A general technique has been developed to relate DEM parameters to rock properties. This is necessary in order to use correct reservoir geomechanical properties during modeling. For any type of particle packing there is a limitation that the maximum ratio between P- and S-wave velocity Vp/Vs that can be modeled is 3 . The static behavior for a loose packing is different from the dynamic behavior. Empirical relations are needed for the static behavior based on numerical test observations. The dynamic behavior for both dense and loose packing can be given by analytical relations. Cosserat continuum theory is needed to derive relations for Vp and Vs. It is shown that by constraining the particle rotation, the S-wave velocity can be

  11. Biogeochemical characterization of the Cointzio reservoir (Morelia, Mexico) and identification of a watershed-dependent cycling of nutrients

    Science.gov (United States)

    Némery, J.; Alvarado, R.; Gratiot, N.; Duvert, C.; Mahé, F.; Duwig, C.; Bonnet, M.; Prat, C.; Esteves, M.

    2009-12-01

    The Cointzio reservoir (capacity 70 Mm3) is an essential component of the drinking water supply (20 %) of Morelia city (1 M inhabitants, Michoacán, Mexico). The watershed is 627 km2 and mainly forested (45 %) and cultivated (43 %) with recent increase of avocados plantations. The mean population density is 65 inh./km2 and there are no waste water treatment plants in the villages leading locally to high levels of organic and nutritive pollution. Soils are mostly volcanic and recent deforestations have led to important processes of erosion especially during the wet season (from June to October). As a result the reservoir presents a high turbidity level (Secchi Del Agua (CNA). The water residence time in the reservoir is lower than one year. Nutrients fluxes entering and exiting the reservoir were calculated as the product of water discharges and weekly concentrations of nutrients. Within the reservoir, the vertical distributions of temperature, oxygen, turbidity, pH (with a Hydrolab probe), nutrients (PO43-, NH4+, NO3-), Dissolved Organic Carbon, chlorophyll a (laboratory analysis with a Hach Lange spectrophotometer), phytoplankton and zooplankton (variety and abundance) were measured every month to determine its seasonal dynamics. Samples of deposited sediments were also taken to assess phosphorus (P) stock. Nutrient inputs revealed to be strongly conditioned by the watershed hydrology. During low flow period (November to May), the baseflow is much more concentrated in dissolved nutrients. On the contrary, the high flows (June to October) bring a high amount of suspended sediments (up to 50g/L) that transport nutrients such as particulate P. Despite the high turbidity level of the reservoir, chlorophyll a concentrations appear important (70 µg/L during the dry season) especially in the first five meters of the water column. The phytoplankton community is dominated by Euglenophyta and Cyanobacteria groups typical of eutrophic waters. This study is the first

  12. Three dimensional heat transport modeling in Vossoroca reservoir

    Science.gov (United States)

    Arcie Polli, Bruna; Yoshioka Bernardo, Julio Werner; Hilgert, Stephan; Bleninger, Tobias

    2017-04-01

    Freshwater reservoirs are used for many purposes as hydropower generation, water supply and irrigation. In Brazil, according to the National Energy Balance of 2013, hydropower energy corresponds to 70.1% of the Brazilian demand. Superficial waters (which include rivers, lakes and reservoirs) are the most used source for drinking water supply - 56% of the municipalities use superficial waters as a source of water. The last two years have shown that the Brazilian water and electricity supply is highly vulnerable and that improved management is urgently needed. The construction of reservoirs affects physical, chemical and biological characteristics of the water body, e.g. stratification, temperature, residence time and turbulence reduction. Some water quality issues related to reservoirs are eutrophication, greenhouse gas emission to the atmosphere and dissolved oxygen depletion in the hypolimnion. The understanding of the physical processes in the water body is fundamental to reservoir management. Lakes and reservoirs may present a seasonal behavior and stratify due to hydrological and meteorological conditions, and especially its vertical distribution may be related to water quality. Stratification can control heat and dissolved substances transport. It has been also reported the importance of horizontal temperature gradients, e.g. inflows and its density and processes of mass transfer from shallow to deeper regions of the reservoir, that also may impact water quality. Three dimensional modeling of the heat transport in lakes and reservoirs is an important tool to the understanding and management of these systems. It is possible to estimate periods of large vertical temperature gradients, inhibiting vertical transport and horizontal gradients, which could be responsible for horizontal transport of heat and substances (e.g. differential cooling or inflows). Vossoroca reservoir was constructed in 1949 by the impoundment of São João River and is located near to

  13. Biological fundamentals of stocking the Zaporizhzhia (Dnipro reservoir with fish

    Directory of Open Access Journals (Sweden)

    O. Fedonenko

    2017-12-01

    Full Text Available Purpose. The main purpose is developing effective measures for stocking the Zaporizhzhia (Dnipro reservoir with valuable fish species by studying the biological and fishery aspects of the formation and exploitation of their commercial stocks. Methods. During the work, we used the generalized results of integrated hydrobiological studies performed in 2015-2017. Materials were collected in the Zaporizhzhia (Dnipro reservoir using standard fishing gears for fish sampling. Collection and processing of phyto-, zooplankton and zoobenthos samples were carried out using conventional hydrobiological methods. Calculation of fish seed amounts was carried out using classical fishery and ichthyological methods. Findings. The status of fish feed supply of the Zaporizhzhia (Dnipro reservoir and its production potential was determined. Based on the obtained data, we calculated the potential productivity of the reservoir. It was found that the reservoir had certain feed supply reserves allowing large scale stocking with the juveniles of commercial fish species. The recommended amounts of reservoir stocking in 2017 were calculated as follows: 570 thousand 1+ carp (weight 100-130 g; 1560 thousand 1+ silver carp (weight of 100-130 g; 400 thousand 1+ bighead carp (weight of 100-130 g; 220 thousand 1+ grass carp (weight of 100-130 g; 135 thousand 0+ tench (weight of 10-20 g; 83 thousand 0+ pike (weight of 100 g; 83 thousand 1+ pikeperch (weight 100 g. Scientific novelty. The presented results of the study of the state of fish feed supply in the reservoir allow stocking with the calculated amounts creating the bases of the rational use of aquatic bioresources with the preservation of the productive potential of commercial fish species exploited by commercial fishery in the Zaporizhzhia (Dnipro reservoir. Practical value. Stocking the reservoir with fish allows improving the overall ecological status of the reservoir and increasing fish productivity under the

  14. A persistent Holocene wetting trend in arid central Asia, with wettest conditions in the late Holocene, revealed by multi-proxy analyses of loess-paleosol sequences in Xinjiang, China

    Science.gov (United States)

    Chen, Fahu; Jia, Jia; Chen, Jianhui; Li, Guoqiang; Zhang, Xiaojian; Xie, Haichao; Xia, Dunsheng; Huang, Wei; An, Chengbang

    2016-08-01

    There are significant differences in the interpretation of the moisture (precipitation) history of arid central Asia (ACA) during the Holocene, as inferred on one hand from speleothem oxygen isotope records, and on the other from lake sediments. Here we present the results of measurements of climatically-sensitive magnetic properties and soil color from four well-dated loess-paleosol sequences from the northern slopes of the Tienshan Mountains and the Yili River valley, Xinjiang, China, in the core area of ACA. Our results demonstrate that the characteristic Holocene paleosol, indicating relatively moist conditions, generally formed after ∼6 ka (1 ka = 1000 cal yr BP) in the study region, and that the accumulation of unweathered loess prevailed during the early Holocene, indicating a dry climate at that time. The magnetic proxies further reveal a trend of generally increasing moisture since the Last Glacial Maximum, with the wettest climate occurring during the late Holocene. This trend of increasing moisture during the Holocene is representative of the Xinjiang region and possibly of the whole of the core area of ACA, and is in marked contrast both to the mid-Holocene moisture maximum observed in the East Asian summer monsoon region and to the general decrease in the strength of the Indian summer monsoon since the early Holocene. Our findings are supported by the results of a climate simulation which indicate a trend of increasing summer and winter precipitation during the Holocene in the core area of ACA, caused mainly by an increase in the strength of the westerlies effected by an increasing latitudinal insolation gradient and by a negative trend of the Arctic Oscillation (AO) or North Atlantic Oscillation (NAO).

  15. Hydrothermal alteration zones and present reservoir conditions: an approach to define production zones at the eastern portion of the Cerro Prieto geothermal field, BC; Zonas de alteracion hidrotermal y condiciones actuales del yacimiento: un enfoque para determinar zonas productoras al oriente del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Camacho Hernandez, Juan Manuel [Comision Federal de Electricidad, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: juan.camacho02@cfe.gob.mx

    2009-07-15

    Geological factors are as essential for locating new wells as they are for defining the production zones of these wells. At the Cerro Prieto geothermal field (CGCP), one of the most important geological factors is identification of the hydrothermal alteration zones (ZAH). These are divided into silica and epidote mineralogical zones (ZMSE), without CaCO{sub 3}, and silica and epidote mineralogical transition zones (ZTMSE), with CaCO{sub 3}. It has been observed that the continuous variation of reservoir thermodynamic conditions (temperature, pressure and enthalpy) is due mainly to the exploitation of geothermal resources. The presence of new thermodynamic conditions recorded at the reservoir has led to the re-location of production wells originally located during the drilling campaign of 2004 to 2006. At the geological sections on the eastern part of the CGCP, adjustments made to the well completions lie on the limits between the ZMSE and ZTMSE zones. In turn, this is related to the current, superior, thermodynamic reservoir conditions. Based on this, a new geologic approach is proposed to define possible production zones for new wells, relating the ZAH zones to current thermodynamic reservoir conditions. [Spanish] Los factores geologicos son determinantes, tanto para establecer nuevos sitios de perforacion como para determinar el intervalo productor de un pozo nuevo. En el campo geotermico de Cerro Prieto (CGCP) una de los factores mas importantes es la determinacion de las zonas de alteracion hidrotermal (ZAH) que se dividen en dos: zona mineralogica de silice y epidota (ZMSE), sin presencia de CaCO{sub 3}, y zona de transicion mineralogica de silice y epidota (ZTMSE), con presencia de CaCO{sub 3}. Por otra parte, tambien se ha constatado que la continua variacion de las condiciones termodinamicas del yacimiento (temperatura, presion y entalpia) es originada en buena medida por la explotacion del recurso geotermico. La ocurrencia de nuevas condiciones

  16. Drop splashing is independent of substrate wetting

    Science.gov (United States)

    Latka, Andrzej; Boelens, Arnout M. P.; Nagel, Sidney R.; de Pablo, Juan J.

    2018-02-01

    A liquid drop impacting a dry solid surface with sufficient kinetic energy will splash, breaking apart into numerous secondary droplets. This phenomenon shows many similarities to forced wetting, including the entrainment of air at the contact line. Because of these similarities and the fact that forced wetting has been shown to depend on the wetting properties of the surface, existing theories predict splashing to depend on wetting properties as well. However, using high-speed interference imaging, we observe that at high capillary numbers wetting properties have no effect on splashing for various liquid-surface combinations. Additionally, by fully resolving the Navier-Stokes equations at length and time scales inaccessible to experiments, we find that the shape and motion of the air-liquid interface at the contact line/edge of the droplet are independent of wettability. We use these findings to evaluate existing theories and to compare splashing with forced wetting.

  17. Wetting and evaporation of binary mixture drops.

    Science.gov (United States)

    Sefiane, Khellil; David, Samuel; Shanahan, Martin E R

    2008-09-11

    Experimental results on the wetting behavior of water, methanol, and binary mixture sessile drops on a smooth, polymer-coated substrate are reported. The wetting behavior of evaporating water/methanol drops was also studied in a water-saturated environment. Drop parameters (contact angle, shape, and volume) were monitored in time. The effects of the initial relative concentrations on subsequent evaporation and wetting dynamics were investigated. Physical mechanisms responsible for the various types of wetting behavior during different stages are proposed and discussed. Competition between evaporation and hydrodynamic flow are evoked. Using an environment saturated with water vapor allowed further exploration of the controlling mechanisms and underlying processes. Wetting stages attributed to differential evaporation of methanol were identified. Methanol, the more volatile component, evaporates predominantly in the initial stage. The data, however, suggest that a small proportion of methanol remained in the drop after the first stage of evaporation. This residual methanol within the drop seems to influence subsequent wetting behavior strongly.

  18. Making cassava flour safe using the wetting method

    Directory of Open Access Journals (Sweden)

    J. Howard Bradbury

    2015-02-01

    Full Text Available Many people, particularly in Africa, suffer various conditions from eating bitter cassava which contains poisonous cyanogens. As well as poisoning, which sometimes causes death, these conditions include konzo, an irreversible paralysis of the legs, which affects mainly children and young women, impaired neurocognition in children, tropical ataxic neuropathy in older people, and aggravation of iodine deficiency disorders (such as goitre and cretinism in iodine deficient areas. The wetting method removes residual cyanogens, and is an additional method of processing cassava flour after its preparation by one of the traditional methods. The wetting method is simple and easy to use, the traditional thick porridge (fufu or ugali made from the treated flour tastes very good, and the method is readily accepted by rural women in East and Central Africa. Regular use of the wetting method by rural women in 13 villages in the Democratic Republic of Congo has prevented konzo amongst more than 9,000 people. We recommend that the wetting method be used as an additional method to traditional methods to remove cyanogens from cassava flour in tropical Africa.

  19. Wet motor geroter fuel pump

    Energy Technology Data Exchange (ETDEWEB)

    Wiernicki, M.V.

    1987-05-05

    This patent describes a wet motor gerotor fuel pump for pumping fuel from a fuel source to an internal combustion which consists of: gerotor pump means comprising an inner pump gear, an outer pump gear, and second tang means located on one of the inner and outer pump gears. The second tang means further extends in a second radial direction radially offset from the first radial direction and forms a driving connection with the first tang means such that the fuel pump pumps fuel from the fuel source into the narrow conduit inlet chamber, through the gerotor pump means past the electric motor means into the outlet housing means substantially along the flow axis to the internal combustion engine.

  20. A review of reservoir desiltation

    DEFF Research Database (Denmark)

    Brandt, Anders

    2000-01-01

    physical geography, hydrology, desilation efficiency, reservoir flushing, density-current venting, sediment slucing, erosion pattern, downstream effects, flow characteristics, sedimentation......physical geography, hydrology, desilation efficiency, reservoir flushing, density-current venting, sediment slucing, erosion pattern, downstream effects, flow characteristics, sedimentation...

  1. Reservoir sedimentation; a literature survey

    NARCIS (Netherlands)

    Sloff, C.J.

    1991-01-01

    A survey of literature is made on reservoir sedimentation, one of the most threatening processes for world-wide reservoir performance. The sedimentation processes, their impacts, and their controlling factors are assessed from a hydraulic engineering point of view with special emphasis on

  2. Reservoir engineering and hydrogeology

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Summaries are included which show advances in the following areas: fractured porous media, flow in single fractures or networks of fractures, hydrothermal flow, hydromechanical effects, hydrochemical processes, unsaturated-saturated systems, and multiphase multicomponent flows. The main thrust of these efforts is to understand the movement of mass and energy through rocks. This has involved treating fracture rock masses in which the flow phenomena within both the fractures and the matrix must be investigated. Studies also address the complex coupling between aspects of thermal, hydraulic, and mechanical processes associated with a nuclear waste repository in a fractured rock medium. In all these projects, both numerical modeling and simulation, as well as field studies, were employed. In the theoretical area, a basic understanding of multiphase flow, nonisothermal unsaturated behavior, and new numerical methods have been developed. The field work has involved reservoir testing, data analysis, and case histories at a number of geothermal projects

  3. Carbon nanotube fiber spun from wetted ribbon

    Science.gov (United States)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  4. Advances in photonic reservoir computing

    Directory of Open Access Journals (Sweden)

    Van der Sande Guy

    2017-05-01

    Full Text Available We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir’s complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  5. EXPLOITATION AND OPTIMIZATION OF RESERVOIR PERFORMANCE IN HUNTON FORMATION, OKLAHOMA

    Energy Technology Data Exchange (ETDEWEB)

    Mohan Kelkar

    2003-10-01

    increases, the remaining oil saturation decreases. This is evident from log and core analysis. (5) Using a compositional simulator, we are able to reproduce the important reservoir characteristics by assuming a two layer model. One layer is high permeability region containing water and the other layer is low permeability region containing mostly oil. The results are further verified by using a dual porosity model. Assuming that most of the volatile oil is contained in the matrix and the water is contained in the fractures, we are able to reproduce important reservoir performance characteristics. (6) Evaluation of secondary mechanisms indicates that CO{sub 2} flooding is potentially a viable option if CO{sub 2} is available at reasonable price. We have conducted detailed simulation studies to verify the effectiveness of CO{sub 2} huff-n-puff process. We are in the process of conducting additional lab tests to verify the efficacy of the same displacement. (7) Another possibility of improving the oil recovery is to inject surfactants to change the near well bore wettability of the rock from oil wet to water wet. By changing the wettability, we may be able to retard the water flow and hence improve the oil recovery as a percentage of total fluid produced. If surfactant is reasonably priced, other possibility is also to use huff-n-puff process using surfactants. Laboratory experiments are promising, and additional investigation continues. (8) Preliminary economic evaluation indicates that vertical wells outperform horizontal wells. Future work in the project would include: (1) Build multi-well numerical model to reproduce overall reservoir performance rather than individual well performance. Special emphasis will be placed on hydrodynamic connectivity between wells. (2) Collect data from adjacent Hunton reservoirs to validate our understanding of what makes it a productive reservoir. (3) Develop statistical methods to rank various reservoirs in Hunton formation. This will allow

  6. Gravity observations for hydrocarbon reservoir monitoring

    NARCIS (Netherlands)

    Glegola, M.A.

    2013-01-01

    In this thesis the added value of gravity observations for hydrocarbon reservoir monitoring and characterization is investigated. Reservoir processes and reservoir types most suitable for gravimetric monitoring are identified. Major noise sources affecting time-lapse gravimetry are analyzed. The

  7. Assesment of bathymetric maps via GIS for water in reservoir

    Directory of Open Access Journals (Sweden)

    Ayhan Ceylan

    Full Text Available In order to adopt measures for storing more water in reservoirs, lakes and ponds; to prevent water pollution, protect water sources and extend the service life of these facilities, it is important for manager (Municipalities, Directorates of the State Hydraulic Works (DSHW, Irrigation Unions etc. to know the current topographic conditions and any changes in the storage capacities of these facilities. This study aimed to identify the updated topographic and bathymetric data required for the efficient management and usage of Altınapa reservoir, changes in surface area and volume of the facility, and to form a Reservoir Information System (RIS. Two digital elevation models, from 2009 and 1984, were used to determine changes in the storage capacity of the reservoir. The calculations indicated that, within this 25-year period, the storage capacity of the reservoir decreased by 12.7% due to sedimentation. A Dam Information System (RIS was developed from a wide range of data sources, including topographic and bathymetric data of the reservoir and its surrounding area, data on specific features such as plant cover, water quality characteristics (Temperature, Dissolved Oxygen (DO, Secchi Disk Depth (SDD and pH, geological structure, average water level, water supplied from springs, evaporation value of the reservoir, and precipitation.

  8. Innovative MIOR Process Utilizing Indigenous Reservoir Constituents

    Energy Technology Data Exchange (ETDEWEB)

    D. O. Hitzman; A. K. Stepp; D. M. Dennis; L. R. Graumann

    2003-03-31

    This research program is directed at improving the knowledge of reservoir ecology and developing practical microbial solutions for improving oil production. The goal is to identify indigenous microbial populations which can produce beneficial metabolic products and develop a methodology to stimulate those select microbes with nutrient amendments to increase oil recovery. This microbial technology has the capability of producing multiple oil-releasing agents. Experimental laboratory work is underway. Microbial cultures have been isolated from produced water samples. Comparative laboratory studies demonstrating in situ production of microbial products as oil recovery agents were conducted in sand packs with natural field waters with cultures and conditions representative of oil reservoirs. Field pilot studies are underway.

  9. Analysis of real-time reservoir monitoring : reservoirs, strategies, & modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Mani, Seethambal S.; van Bloemen Waanders, Bart Gustaaf; Cooper, Scott Patrick; Jakaboski, Blake Elaine; Normann, Randy Allen; Jennings, Jim (University of Texas at Austin, Austin, TX); Gilbert, Bob (University of Texas at Austin, Austin, TX); Lake, Larry W. (University of Texas at Austin, Austin, TX); Weiss, Chester Joseph; Lorenz, John Clay; Elbring, Gregory Jay; Wheeler, Mary Fanett (University of Texas at Austin, Austin, TX); Thomas, Sunil G. (University of Texas at Austin, Austin, TX); Rightley, Michael J.; Rodriguez, Adolfo (University of Texas at Austin, Austin, TX); Klie, Hector (University of Texas at Austin, Austin, TX); Banchs, Rafael (University of Texas at Austin, Austin, TX); Nunez, Emilio J. (University of Texas at Austin, Austin, TX); Jablonowski, Chris (University of Texas at Austin, Austin, TX)

    2006-11-01

    The project objective was to detail better ways to assess and exploit intelligent oil and gas field information through improved modeling, sensor technology, and process control to increase ultimate recovery of domestic hydrocarbons. To meet this objective we investigated the use of permanent downhole sensors systems (Smart Wells) whose data is fed real-time into computational reservoir models that are integrated with optimized production control systems. The project utilized a three-pronged approach (1) a value of information analysis to address the economic advantages, (2) reservoir simulation modeling and control optimization to prove the capability, and (3) evaluation of new generation sensor packaging to survive the borehole environment for long periods of time. The Value of Information (VOI) decision tree method was developed and used to assess the economic advantage of using the proposed technology; the VOI demonstrated the increased subsurface resolution through additional sensor data. Our findings show that the VOI studies are a practical means of ascertaining the value associated with a technology, in this case application of sensors to production. The procedure acknowledges the uncertainty in predictions but nevertheless assigns monetary value to the predictions. The best aspect of the procedure is that it builds consensus within interdisciplinary teams The reservoir simulation and modeling aspect of the project was developed to show the capability of exploiting sensor information both for reservoir characterization and to optimize control of the production system. Our findings indicate history matching is improved as more information is added to the objective function, clearly indicating that sensor information can help in reducing the uncertainty associated with reservoir characterization. Additional findings and approaches used are described in detail within the report. The next generation sensors aspect of the project evaluated sensors and packaging

  10. Enhanced Oil Recovery from Oil-wet Carbonate Rock by Spontaneous Imbibition of Aqueous Surfactant Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Standnes, Dag Chun

    2001-09-01

    The main theme of this thesis is an experimental investigation of spontaneous imbibition (SI) of aqueous cationic surfactant solution into oil-wet carbonate (chalk- and dolomite cores). The static imbibition process is believed to represent the matrix flow of oil and water in a fractured reservoir. It was known that aqueous solution of C{sub 12}-N(CH{sub 3}){sub 3}Br (C12TAB) was able to imbibe spontaneously into nearly oil-wet chalk material, but the underlying mechanism was not understood. The present work was therefore initiated, with the following objectives: (1) Put forward a hypothesis for the chemical mechanism underlying the SI of C12TAB solutions into oil-wet chalk material based on experimental data and (2) Perform screening tests of low-cost commercially available surfactants for their ability to displace oil by SI of water into oil-wet carbonate rock material. It is essential for optimal use of the surfactant in field application to have detailed knowledge about the mechanism underlying the SI process. The thesis also discusses some preliminary experimental results and suggests mechanisms for enhanced oil recovery from oil-wet carbonate rock induced by supply of thermal energy.

  11. Random Vibration Testing of Advanced Wet Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander

    2015-01-01

    Advanced wet tantalum capacitors allow for improved performance of power supply systems along with substantial reduction of size and weight of the systems that is especially beneficial for space electronics. Due to launch-related stresses, acceptance testing of all space systems includes random vibration test (RVT). However, many types of advanced wet tantalum capacitors cannot pass consistently RVT at conditions specified in MIL-PRF-39006, which impedes their use in space projects. This requires a closer look at the existing requirements, modes and mechanisms of failures, specifics of test conditions, and acceptance criteria. In this work, different lots of advanced wet tantalum capacitors from four manufacturers have been tested at step stress random vibration conditions while their currents were monitored before, during, and after the testing. It has been shown that the robustness of the parts and their reliability are mostly due to effective self-healing processes and limited current spiking or minor scintillations caused by RVT do not increase the risk of failures during operation. A simple model for scintillations events has been used to simulate current spiking during RVT and optimize test conditions. The significance of scintillations and possible effects of gas generation have been discussed and test acceptance criteria for limited current spiking have been suggested.

  12. Air–water CO2 and CH4 fluxes along a river–reservoir continuum: Case study in the Pengxi River, a tributary of the Yangtze River in the Three Gorges Reservoir, China

    Science.gov (United States)

    Water surface greenhouse gas (GHG) emissions in freshwater reservoirs are closely related to limnological processes in the water column. Affected by both reservoir operation and seasonal changes, variations in the hydro-morphological conditions in the river–reservoir continuum will create distinctiv...

  13. Sediment Characteristics of Tennessee Streams and Reservoirs

    National Research Council Canada - National Science Library

    Trimble, Stanley W; Carey, William P

    1984-01-01

    Suspended-sediment and reservoir sedimentation data have been analyzed to determine sediment yields and transport characteristics of Tennessee streams Data from 31 reservoirs plus suspended-sediment...

  14. Skid resistance determination for pavement management and wet-weather road safety

    Directory of Open Access Journals (Sweden)

    T.F. Fwa

    2017-09-01

    Full Text Available Road accidents during wet weather have been a topic of major concern of road engineers in regions of wet-tropical climate and in other parts of the world during the wet season of the year. Road safety studies indicate that approximately 20% of all road accidents occurred during wet weather, and that the skid resistance of wet pavements have a major influence on the occurrences of wet-weather accidents. Monitoring of wet pavement skid resistance has been an integral part of a typical pavement management system. However, because of the lack of prediction capability of pavement skid resistance under various rainfall intensities, the minimum skid resistance threshold for safe wet-weather driving has been specified by highway agencies based on either engineering judgement or past experience. It is shown in this paper that the single-point minimum skid resistance threshold is inadequate to offer a complete description of the skid resistance performance of the pavement sections in question for effective management of a road network. It is unable to assess the risk involved in an actual wet-weather condition where the pavement surface water-film thickness and vehicle speed are different from standard test conditions. This limitation of the current system of specifying a minimum skid resistance threshold can be overcome by adopting a theoretically sound approach to represent pavement skid resistance under different conditions of water-film thickness and vehicle speed. This paper describes the theoretical basis of the approach and the development of a mechanistically derived three-dimensional finite-element skid resistance simulation model to predict skid resistance. The application of the proposed approach and the skid resistance prediction procedure in pavement management system and wet-weather driving safety assessment is presented.

  15. Changes to the Bakomi Reservoir

    Directory of Open Access Journals (Sweden)

    Kubinský Daniel

    2014-08-01

    Full Text Available This article is focused on the analysis and evaluation of the changes of the bottom of the Bakomi reservoir, the total volume of the reservoir, ecosystems, as well as changes in the riparian zone of the Bakomi reservoir (situated in the central Slovakia. Changes of the water component of the reservoir were subject to the deposition by erosion-sedimentation processes, and were identifed on the basis of a comparison of the present relief of the bottom of reservoir obtained from feld measurements (in 2011 with the relief measurements of the bottom obtained from the 1971 historical maps, (i.e. over a period of 40 years. Changes of landscape structures of the riparian zone have been mapped for the time period of 1949–2013; these changes have been identifed with the analysis of ortophotomaps and the feld survey. There has been a signifcant rise of disturbed shores with low herb grassland. Over a period of 40 years, there has been a deposition of 667 m3 of sediments. The results showed that there were no signifcant changes in the local ecosystems of the Bakomi reservoir in comparison to the other reservoirs in the vicinity of Banská Štiavnica.

  16. New 'wet and dry' coolers; Neuentwicklung von Wet- und Dry-Kuehlern

    Energy Technology Data Exchange (ETDEWEB)

    Filippini, S.; Macchi, E.; Merlo, U. [LU-VE CONTARDO S.p.A., Uboldo (Italy)

    2003-07-01

    'Wet and dry' coolers are the result of a 4-year research programme. Theoretical fundamentals of heat transfer with and without water spraying are presented to begin with, as are the method of calculation using innovative FLUENTL software, and the experimental result. 'Wet and dry' systems consist of one or several chillers and a water conditioning system. They function as conventional dry coolers as long as the ambient temperature is low enough to ensure the required cooling water temperature. As the ambient temperature increases, demineralised water is sprayed onto the heat exchanger surface. The system has the following advantages as compared to conventional evaporation systems: (a) Water consumption is reduced significantly as water is required only during a limited period of the year; (b) Nearly complete evaporation of the sprayed water without water circulation, i.e. no collector basin is required below the heat exchanger. (c) Environment-friendliness: No undesired plumes, no health risk (e.g. legionellosis) from open basins of warm water, no residual droplets; (d) Automatic control minimises energy and water consumption in all seasons. (orig.) [German] Die Unterlage beschreibt die Ergebnisse eines vierjaehrigen Forschungsprogramms fuer die Entwicklung der extrem innovativen ''Wet-and-Dry''-Produktreihe. Es werden eingangs die wichtigsten theoretischen Grundlagen des Waermeuebergangs mit bzw. ohne Spruehwassereinsatz vorgestellt, die Berechnungsmethodologie mit innovativer FLUENT-Software und das experimentelle Ergebnis. Das ''Wet-and-Dry''-System besteht aus einem oder mehreren Kuehlern und einem Gesamtwasseraufbereitungssystem. Diese Produkte arbeiten als herkoemmliche ''Trocken-''Kuehler, solange die Aussentemperatur niedrig genug ist, um die verlangte Kuehlwassertemperatur zu gewaehrleisten. Wenn die Umgebungstemperatur steigt, wird entmineralisiertes Wasser auf die

  17. The tight reservoir microscopic classification of southern part of Qijia area in Songliao Basin

    Science.gov (United States)

    Hang, Fu

    2018-02-01

    With the decreasing of the conventional oil and gas reserves, the unconventional tight oil and gas are gradually becoming the focus of the study. The casting thin section, conventional mercury injection, constant velocity and pressure mercury and other experimental methods, tight reservoir microscopic characteristics in southern part of Qijia area were studied in this paper. Based on the above conditions, combined with the parameters of pore type, pore throat radius, the reservoir is divided into two types, conventional reservoir and low permeability tight reservoir. Reservoir conventional reservoir permeability values are greater than 1mD, low permeability tight reservoirs are classified into IIa type and IIb type, which provides some reference value for the actual exploration and development.

  18. Characteristics of wet work in nurses

    NARCIS (Netherlands)

    Jungbauer, FHW; Steenstra, FB; Groothoff, JW; Coenraads, PJ

    Background objectives: Nursing is known for its high prevalence of hand dermatitis, mainly caused by the intense exposure to wet work in nursing activities. We aimed to study the characteristics of wet work exposure in nursing. Method: Trained observers monitored the duration and frequency of

  19. Defined wetting properties of optical surfaces

    Science.gov (United States)

    Felde, Nadja; Coriand, Luisa; Schröder, Sven; Duparré, Angela; Tünnermann, Andreas

    2017-10-01

    Optical surfaces equipped with specific functional properties have attracted increasing importance over the last decades. In the light of cost reduction, hydrophobic self-cleaning behavior is aspired. On the other side, hydrophilic properties are interesting due to their anti-fog effect. It has become well known that such wetting states are significantly affected by the surface morphology. For optical surfaces, however, this fact poses a problem, as surface roughness can induce light scattering. The generation of optical surfaces with specific wetting properties, hence, requires a profound understanding of the relation between the wetting and the structural surface properties. Thus, our work concentrates on a reliable acquisition of roughness data over a wide spatial frequency range as well as on the comprehensive description of the wetting states, which is needed for the establishment of such correlations. We will present our advanced wetting analysis for nanorough optical surfaces, extended by a vibration-based procedure, which is mainly for understanding and tailoring the wetting behavior of various solid-liquid systems in research and industry. Utilizing the relationships between surface roughness and wetting, it will be demonstrated how different wetting states for hydrophobicity and hydrophilicity can be realized on optical surfaces with minimized scatter losses.

  20. Leaf Wetness within a Lily Canopy

    NARCIS (Netherlands)

    Jacobs, A.F.G.; Heusinkveld, B.G.; Klok, E.J.

    2005-01-01

    A wetness duration experiment was carried out within a lily field situated adjacent to coastal dunes in the Netherlands. A within-canopy model was applied to simulate leaf wetness in three layers, with equal leaf area indices, within the canopy. This simulation model is an extension of an existing

  1. Curvature controlled wetting in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Mikheev, Lev V.

    1995-01-01

    . As the radius of the substrate r0→∞, the leading effect of the curvature is adding the Laplace pressure ΠL∝r0-1 to the pressure balance in the film. At temperatures and pressures under which the wetting is complete in planar geometry, Laplace pressure suppresses divergence of the mean thickness of the wetting...

  2. TROPHIC STATE OF SMALL RETENTION RESERVOIRS IN PODLASIE VOIVODESHIP

    Directory of Open Access Journals (Sweden)

    Joanna Szczykowska

    2017-09-01

    Full Text Available The study was carried out using water samples from two small retention reservoirs located in the communes: Czarna Białostocka and Turośń Kościelna in Podlaskie Voivodeship. The main tasks of both reservoirs are to improve the water balance by means of regulating the levels and water outflow. Three characteristic measurement and control points were selected on both reservoirs in accordance to the water flow in the longitudinal section. The first and third points were located near the inflow and outflow of water, while the second in the middle of the reservoirs. Samples of water for the study were collected from the surface layer of the shore zone of the reservoirs once a month from March 2015 to February 2017 (water from two hydrological years was analyzed. Water samples were subject to determination of total phosphorus, total nitrogen, and chlorophyll “a” concentrations, as well as turbidity. Contamination of the water reservoirs with biogenic compounds is a common problem and at the same time difficult to eliminate due to the scattered nature of external sources of pollution, especially in the case of agricultural catchments, as well as the inflow of untreated sewage from areas directly adjacent to the reservoirs. Based on achieved results, high values of TSI (TN, TSI (TP, TSI (Chl, and overall TSI, clearly indicate the progressive degradation of water quality in analyzed reservoirs. Appearing water blooms due to the mass development of phytoplankton adversely affect the quality of water in the reservoirs and biochemical processes occurring both in water and bottom sediments, are conditioned by progressive eutrophication.

  3. Sediment problems in reservoirs. Control of sediment deposits

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, Tom

    1997-12-31

    When a reservoir is formed on a river, sediment will deposit in the reservoir. Such processes are unfortunate, for instance, for the implementation of hydroelectric energy. This thesis studies the problem of reservoir sedimentation and discusses methods of removing the sediments. Various aspects of reservoir sedimentation are discussed. Anthropogenic impacts seem to greatly affect the erosion processes. Temporal distribution is uneven, mainly because of the very large flood events. A world map showing the Reservoir Capacity: Annual Sediment Inflow ratio for reservoirs with volume equal to 10% of annual inflow has been prepared. The map shows that sedimentation is severe in the western parts of North and South America, eastern, southern and northern Africa, parts of Australia and most of Asia. The development of medium-sized reservoirs is difficult, as they are too large for conventional flushing technique and too small to store the sediment that accumulates during their economic lifetime. A computer model, SSIIM, was used with good results in a case study of two flood drawdown trials in Lake Roxburg, New Zealand. Two techniques have been developed that permits controlled suction of sediment and water into a pipe: the Slotted Pipe Sediment Sluicer (SPSS) and the Saxophone Sediment Sluicer (SSS). The techniques exploit the inflow pattern in through a slot in a pipe. An equation describing this inflow pattern was derived and verified experimentally. The SPSS is fixed near the reservoir bed, and sediment that deposits on top of it is removed in the sluicing process. The SSS sluices sediment from the surface of the sediment deposits. Some technical and economic conditions affecting the economics of sediment removal from reservoirs have been identified and studied. 79 refs., 112 figs., 14 tabs.

  4. A reservoir simulation approach for modeling of naturally fractured reservoirs

    Directory of Open Access Journals (Sweden)

    H. Mohammadi

    2012-12-01

    Full Text Available In this investigation, the Warren and Root model proposed for the simulation of naturally fractured reservoir was improved. A reservoir simulation approach was used to develop a 2D model of a synthetic oil reservoir. Main rock properties of each gridblock were defined for two different types of gridblocks called matrix and fracture gridblocks. These two gridblocks were different in porosity and permeability values which were higher for fracture gridblocks compared to the matrix gridblocks. This model was solved using the implicit finite difference method. Results showed an improvement in the Warren and Root model especially in region 2 of the semilog plot of pressure drop versus time, which indicated a linear transition zone with no inflection point as predicted by other investigators. Effects of fracture spacing, fracture permeability, fracture porosity, matrix permeability and matrix porosity on the behavior of a typical naturally fractured reservoir were also presented.

  5. Comparison of wet and dry corn stover harvest and storage

    Energy Technology Data Exchange (ETDEWEB)

    Shinners, Kevin J.; Binversie, Benjamin N. [University of Wisconsin, Madison, WI (United States). Department of Biological Systems Engineering; Muck, Richard E.; Weimer, Paul J. [US Dairy Forage Research Center, USDA-ARS, University of Wisconsin (United States)

    2007-04-15

    Corn stover has great potential as a biomass feedstock, but harvest and storage of this material is challenged by weather conditions at harvest; material moisture; and equipment shortcomings. Field drying characteristics, harvest efficiency and rate, product bulk density, and storage characteristics were quantified for stover harvested and stored in wet or dry form. Only in one case did stover reach dry baling moisture ({proportional_to}20%) in the first 4 d of field drying. Conventional hay and forage harvesting equipment (shredder, rake, forage harvester, round baler, and square baler) produced an average harvested yield of about 30% of the total available stover mass. Harvesting capacity of this equipment was limited by difficulty in gathering shredded stover. The density of chopped or baled stover was less than that typically expected with hay and forage crops. Losses of wet stover ensiled at 44% moisture averaged 3.9% with low levels of fermentation products. Dry stover losses were 3.3% and 18.1% for bales stored indoors and outdoors, respectively. Harvesting wet stover right after grain harvest was timelier and resulted in a greater harvesting rate and yield compared to dry stover harvest. Storing wet stover by ensiling resulted in lower losses and more uniform product moisture compared to dry stover bales stored outdoors. (author)

  6. Growth of Sulphuric Acid Nanoparticles Under Wet and Dry Conditions

    Czech Academy of Sciences Publication Activity Database

    Škrabalová, Lenka; Brus, David; Antilla, T.; Ždímal, Vladimír; Lihavainen, H.

    2014-01-01

    Roč. 14, č. 12 (2014), s. 6461-6475 ISSN 1680-7316 R&D Projects: GA AV ČR IAA200760905 Grant - others:AFCEP(FI) 1118615 Institutional support: RVO:67985858 Keywords : binary nucleation * sulphuric acid - water * condensational growth Subject RIV: BJ - Thermodynamics Impact factor: 5.053, year: 2014

  7. Global Warming Impact: Flood Events, Wet-Dry Conditions and ...

    African Journals Online (AJOL)

    Agriculture is weather-dependent so a significant alteration in the world climate would cause lot of changes in agricultural practice and agricultural productivity in the world. For man to feed himself adequately man must adjust his food production activities in line with the changes in the weather and climate. This paper ...

  8. A pore-level scenario for the development of mixed-wettability in oil reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Kovscek, A.R.; Wong, H.; Radke, C.J.

    1992-09-01

    Understanding the role of thin films in porous media is vital if wettability is to be elucidated at the pore level. The type and thickness of films coating pore walls determines reservoir wettability and whether or not reservoir rock can be altered from its initial state of wettability. Pore shape, especially pore wall curvature, is an important factor in determining wetting-film thicknesses. Yet, pore shape and the physics of thin wetting films are generally neglected in models of flow in porous rocks. This paper incorporates thin-film forces into a collection of star-shaped capillary tubes model to describe the geological development of mixed-wettability in reservoir rock. Here, mixed-wettability refers to continuous and distinct oil and water-wetting surfaces coexisting in the porous medium. The proposed model emphasizes the remarkable role of thin films. New pore-level fluid configurations arise that are quite unexpected. For example, efficient water displacement of oil (i.e, low residual oil saturation) characteristic of mixed-wettability porous media is ascribed to interconnected oil lenses or rivulets which bridge the walls adjacent to a pore corner. Predicted residual oil saturations are approximately 35 % less in mixed-wet rock compared to completely water-wet rock. Calculated capillary pressure curves mimic those of mixed-wet porous media in the primary drainage of water, imbibition of water, and secondary drainage modes. Amott-Harvey indices range from {minus}0.18 to 0.36 also in good agreement with experimental values. (Morrow et al, 1986; Judhunandan and Morrow, 1991).

  9. Advanced reservoir characterization and evaluation of CO{sub 2} gravity drainage in the naturally fractured Spraberry Trend Area. Annual report, September 1, 1996--August 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Schechter, D.S.

    1998-07-01

    The overall goal of this project is to assess the economic feasibility of CO{sub 2} flooding the naturally fractured Spraberry Trend Area in West Texas. This objective is being accomplished by conducting research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interaction in the reservoirs, (3) reservoir performance analysis, and (4) experimental investigations on CO{sub 2} gravity drainage in Spraberry whole cores. This report provides results of the second year of the five-year project for each of the four areas. In the first area, the author has completed the reservoir characterization, which includes matrix description and detection (from core-log integration) and fracture characterization. This information is found in Section 1. In the second area, the author has completed extensive inhibition experiments that strongly indicate that the weakly water-wet behavior of the reservoir rock may be responsible for poor waterflood response observed in many Spraberry fields. In the third area, the author has made significant progress in analytical and numerical simulation of performance in Spraberry reservoirs as seen in Section 3. In the fourth area, the author has completed several suites of CO{sub 2} gravity drainage in Spraberry and Berea whole cores at reservoir conditions and reported in Section 4. The results of these experiments have been useful in developing a model for free-fall gravity drainage and have validated the premise that CO{sub 2} will recover oil from tight, unconfined Spraberry matrix. The final three years of this project involves implementation of the CO{sub 2} pilot. Up to twelve new wells are planned in the pilot area; water injection wells to contain the CO{sub 2}, three production wells to monitor performance of CO{sub 2}, CO{sub 2} injection wells including one horizontal injection well and logging observation wells to monitor CO{sub 2} flood fronts. Results of drilling

  10. THE SURDUC RESERVOIR (ROMANIA

    Directory of Open Access Journals (Sweden)

    Niculae Iulian TEODORESCU

    2008-06-01

    Full Text Available The Surduc reservoir was projected to ensure more water when water is scarce and to thus provide especially the city Timisoara, downstream of it with water.The accumulation is placed on the main affluent of the Bega river, Gladna in the upper part of its watercourse.The dam behind which this accumulation was created is of a frontal type made of enrochements with a masque made of armed concrete on the upstream part and protected/sustained by grass on the downstream. The dam is 130m long on its coping and a constructed height of 34 m. It is also endowed with spillway for high water and two bottom outlets formed of two conduits, at the end of which is the microplant. The second part of my paper deals with the hydrometric analysis of the Accumulation Surduc and its impact upon the flow, especially the maximum run-off. This influence is exemplified through the high flood from the 29th of July 1980, the most significant flood recorded in the basin with an apparition probability of 0.002%.

  11. The Role of Wet Wrap Therapy in Skin Disorders - A literature Review

    DEFF Research Database (Denmark)

    Andersen, Rosa Marie; Thyssen, Jacob P; Maibach, Howard I

    2015-01-01

    with wet wrap bandages compared to emollients only. While temporary suppression of hypothalamic-pituitary-adrenocortical-axis was seen due to systemic bioactivity of corticosteroids, no long-term observation studies on putative adverse-effects were identified. One hypothesis suggests that wet wrap therapy......Wet wrap therapy, based on skin application of a double layer of tubular bandages or gauze with a moist first inner layer and a dry second outer layer, is utilized to treat various pruritic conditions, in particular severe and refractory atopic dermatitis. This review, by literature search......, evaluates current knowledge about wet wrap therapy. Wet wrap therapy superimposed topical corticosteroids appears more efficient than emollients only, at least for short-time treatments. Despite higher efficacy, there is a tendency towards more frequent infections when topical corticosteroids are covered...

  12. Visualization of viscous coupling effects in heavy oil reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz-Arango, J.D. [Calgary Univ., AB (Canada). Tomographic Imaging and Porous Media Laboratory; Kantzas, A. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Calgary Univ., AB (Canada). Tomographic Imaging and Porous Media Laboratory

    2008-10-15

    Some heavy oil reservoirs in Venezuela and Canada have shown higher than expected production rates attributed to the effects of foamy oil or enhanced solution gas drive. However, foamy oil 2-phase flow does not fully explain oil rate enhancement in heavy oil reservoirs. In this study, flow visualization experiments were conducted in a 2-D etched network micromodel in order to determine the effect of the viscosity ratio on oil mobility at the pore scale. The micromodel's pattern was characterized by macroscopic heterogeneities with a random network of larger pore bodies interconnected with a random network of smaller pore throats. Displacement tests were conducted with green-dyed distilled water as a wetting phase. N-octane, bromododecane and mineral oil were used as non-wetting phases. An unsteady-state method was used to obtain displacement data, and the Alternate method was used to calculate relative permeabilities. Results of the study showed that relative permeabilities depended on the viscosity ratio of the fluids flowing through the porous medium. Channel and annular flows co-existed, and water lubrication was stronger at higher water saturations. The results of the study explained the abnormally high production rates in heavier oil fields. 19 refs., 3 tabs., 14 figs.

  13. Experimental evaluation on the damages of different drilling modes to tight sandstone reservoirs

    Directory of Open Access Journals (Sweden)

    Gao Li

    2017-07-01

    Full Text Available The damages of different drilling modes to reservoirs are different in types and degrees. In this paper, the geologic characteristics and types of such damages were analyzed. Then, based on the relationship between reservoir pressure and bottom hole flowing pressure corresponding to different drilling modes, the experimental procedures on reservoir damages in three drilling modes (e.g. gas drilling, liquid-based underbalanced drilling and overbalanced drilling were designed. Finally, damage simulation experiments were conducted on the tight sandstone reservoir cores of the Jurassic Ahe Fm in the Tarim Basin and Triassic Xujiahe Fm in the central Sichuan Basin. It is shown that the underbalanced drilling is beneficial to reservoir protection because of its less damage on reservoir permeability, but it is, to some extent, sensitive to the stress and the empirical formula of stress sensitivity coefficient is obtained; and that the overbalanced drilling has more reservoir damages due to the invasion of solid and liquid phases. After the water saturation of cores rises to the irreducible water saturation, the decline of gas logging permeability speeds up and the damage degree of water lock increases. It is concluded that the laboratory experiment results of reservoir damage are accordant with the reservoir damage characteristics in actual drilling conditions. Therefore, this method reflects accurately the reservoir damage characteristics and can be used as a new experimental evaluation method on reservoir damage in different drilling modes.

  14. Microbial Life in an Underground Gas Storage Reservoir

    Science.gov (United States)

    Bombach, Petra; van Almsick, Tobias; Richnow, Hans H.; Zenner, Matthias; Krüger, Martin

    2015-04-01

    While underground gas storage is technically well established for decades, the presence and activity of microorganisms in underground gas reservoirs have still hardly been explored today. Microbial life in underground gas reservoirs is controlled by moderate to high temperatures, elevated pressures, the availability of essential inorganic nutrients, and the availability of appropriate chemical energy sources. Microbial activity may affect the geochemical conditions and the gas composition in an underground reservoir by selective removal of anorganic and organic components from the stored gas and the formation water as well as by generation of metabolic products. From an economic point of view, microbial activities can lead to a loss of stored gas accompanied by a pressure decline in the reservoir, damage of technical equipment by biocorrosion, clogging processes through precipitates and biomass accumulation, and reservoir souring due to a deterioration of the gas quality. We present here results from molecular and cultivation-based methods to characterize microbial communities inhabiting a porous rock gas storage reservoir located in Southern Germany. Four reservoir water samples were obtained from three different geological horizons characterized by an ambient reservoir temperature of about 45 °C and an ambient reservoir pressure of about 92 bar at the time of sampling. A complementary water sample was taken at a water production well completed in a respective horizon but located outside the gas storage reservoir. Microbial community analysis by Illumina Sequencing of bacterial and archaeal 16S rRNA genes indicated the presence of phylogenetically diverse microbial communities of high compositional heterogeneity. In three out of four samples originating from the reservoir, the majority of bacterial sequences affiliated with members of the genera Eubacterium, Acetobacterium and Sporobacterium within Clostridiales, known for their fermenting capabilities. In

  15. Drought and reservoirs: intended benefits and unintended consequences

    Science.gov (United States)

    Di Baldassarre, Giuliano; AghaKouchak, Amir; Rangecroft, Sally; Wanders, Niko; Kuil, Linda; Veldkamp, Ted; van Loon, Anne

    2017-04-01

    Socioeconomic drought can be broadly defined as a condition whereby water demand cannot be satisfied by water supply. Here we posit that while reservoirs often alleviate socioeconomic drought, they can lead to unintended consequences in the medium-long term. Losses caused by socioeconomic drought tend to trigger public pressure for action, which can result in the introduction or expansion of reservoirs to store more water during high flow conditions, and release it during low flow conditions. In the short term, increasing reservoir storage is often beneficial because frequency, magnitude, and duration of drought can be significantly reduced. Yet, it is important to note that reservoirs may fail in mitigating major, prolonged drought, because reservoir storage is unavoidably limited. In the medium-long term, two main dynamics tend to emerge, which often generate unintended consequences. The first one, termed here as "supply-demand cycle", is when increasing water supply triggers additional development and thus generates higher demand, which then offsets the benefit of reservoirs as a water supply source. This is a self-reinforcing feedback, or vicious cycle, as the occurrence of a new socioeconomic drought will then likely trigger further expansion of reservoir storage to, again, increase water supply. A second dynamic, termed here as "reservoir effect" (after White's "levee effect"), is when extended periods of abundant water supply, secured by reservoirs, generate a decline of coping capacities through increased competition for water and reduced shocks to the system, which in turn increases the vulnerability of the system to socio-economic drought. In other words, while a frequent experience of water shortages can help keep high levels of preparedness, some elements of system's resilience can be lost when minor-to-moderate events are avoided. As a result, the development of reservoirs can generate a shift from frequent socioeconomic drought conditions to rare

  16. Permeability restoration in underground disposal reservoirs

    International Nuclear Information System (INIS)

    Grubbs, D.M.; Haynes, C.D.; Whittle, G.P.

    1973-09-01

    The aim of the research performed was to explore methods of permeability restoration in underground disposal reservoirs that may improve the receptive capacity of a well to a level that will allow continued use of the disposal zone without resorting to elevated injection pressures. The laboratory investigation employed a simulated open-hole completion in a disposal well wherein the entire formation face is exposed to the well bore. Cylindrical core samples from representative reservoir rocks through which a central vertical opening or borehole had been drilled were injected with a liquid waste obtained from a chemical manufacturing plant. This particular waste material was found to have a moderate plugging effect when injected into samples of reservoir rocks in a prior study. A review was made of the chemical considerations that might account for the reduction of permeability in waste injection. Purpose of this study was to ascertain the conditions under which the precipitation of certain compounds might occur in the injection of the particular waste liquid employed. A summary of chemical calculations is contained in Appendix B. The data may be useful in the treatment of wastes prior to injection and in the design of restoration procedures where analyses of waste liquids and interstitial materials are available. The results of permeability restoration tests were analyzed mathematically by curve-fitting techniques performed by a digital computer. A summary of the analyses is set forth in the discussion of test results and examples of computer printouts are included in Appendix A

  17. Phytoplankton and water quality in a Mediterranean drinking-water reservoir (Marathonas Reservoir, Greece).

    Science.gov (United States)

    Katsiapi, Matina; Moustaka-Gouni, Maria; Michaloudi, Evangelia; Kormas, Konstantinos Ar

    2011-10-01

    Phytoplankton and water quality of Marathonas drinking-water Reservoir were examined for the first time. During the study period (July-September 2007), phytoplankton composition was indicative of eutrophic conditions although phytoplankton biovolume was low (max. 2.7 mm³ l⁻¹). Phytoplankton was dominated by cyanobacteria and diatoms, whereas desmids and dinoflagellates contributed with lower biovolume values. Changing flushing rate in the reservoir (up to 0.7% of reservoir's water volume per day) driven by water withdrawal and occurring in pulses for a period of 15-25 days was associated with phytoplankton dynamics. Under flushing pulses: (1) biovolume was low and (2) both 'good' quality species and the tolerant to flushing 'nuisance' cyanobacterium Microcystis aeruginosa dominated. According to the Water Framework Directive, the metrics of phytoplankton biovolume and cyanobacterial percentage (%) contribution indicated a moderate ecological water quality. In addition, the total biovolume of cyanobacteria as well as the dominance of the known toxin-producing M. aeruginosa in the reservoir's phytoplankton indicated a potential hazard for human health according to the World Health Organization.

  18. Water Productivity of Irrigated Rice under Transplanting, Wet Seeding and Dry Seeding Methods of Cultivation

    Directory of Open Access Journals (Sweden)

    Murali, NS.

    1997-01-01

    Full Text Available Water productivity (WP of irrigated lowland rice was determined during the 1994 dry (January to May and wet (August to December seasons on a heavy clay acid sulphate soil. Treatments consisted of three cultivation methods : transplanted rice, pregerminated seeds broadcasted on puddled soil (wet seeding and dry seeds broadcasted on unpuddled soil (dry seeding. In wet and dry seeded plots, continuous standing water condition was initiated 17 days after sowing. Total water requirement for rice production was highest in transplanted plots (755 mm in wet season and 1154 mm in dry season and was lowest in dry seeded plots (505 mm in wet season and 1040 mm in dry season. Dry seeding required no water for land preparation but transplanting and wet seeding methods required 18 - 20 % of total water requirement in dry season and 27 - 29 % in wet season. Total percolation was maximum (99 mm in wet season and 215 mm in dry season in dry seeding method and was minimum (62 mm in wet season and 94 mm in dry season in transplanting method. In dry and wet seeding methods, daily percolation gradually decreased with the age of the crop. Total seepage loss did not show any significant difference between the cultivation methods in the two seasons. Grain yield was not affected by the three cultivation methods in both seasons. Water productivity (the ratio between grain yield and total amount of water used in production was 3.5 - 4.1 kg ha-1 mm-1, 3.8 - 4.4 kg ha-1 mm-1 and 4.1 - 5.5 kg ha-1 mm-1 in transplanted, wet seeded and dry seeded rice, respectively. Labour requirement for land preparation and sowing was maximum in transplanted (219 - 226 man-hours ha-1 followed by wet (104 -112 man-hours ha-1 and dry seeded (94 - 99 man-hours ha-1 methods. However, in wet season extra labour (77 man-hours ha-1 was required for weeding after crop establishment in dry and wet seeding methods. Crop maturity was 20 days earlier in wet and dry seeding methods compared to

  19. Analysis of CO2 separation and simulation of a partially wetted hollow fiber membrane contactor.

    Science.gov (United States)

    Keshavarz, P; Fathikalajahi, J; Ayatollahi, S

    2008-04-15

    A steady state model was developed for a microporous hollow fiber membrane contactor operated under partially wetted conditions accompanied by chemical reactions, to analyze CO2 absorption into the aqueous solution of diethanolamine (DEA). The proposed diffusion-reaction model contains reversible chemical reactions in the liquid bulk as well as wetted parts of the membrane pores. A numerical scheme was employed to solve the simultaneous nonlinear mathematical expressions, and the results were validated with experimental data in the literature. The gas phase concentration and velocity profile in axial direction inside the shell, liquid concentration profile in axial and radial directions inside the fibers, and also those within the wetted parts of the pores were predicted by using the model. The results of the model and proposed numerical scheme show that membrane wetting, even in very low fractions, can decrease the absorption flux significantly. The wetting fraction of membrane was predicted both with and without consideration of chemical reactions inside the wetted pores. The results indicate that the chemical reactions inside the wetted pores, which have been disregarded in the literature, have considerable effects on the prediction of membrane wetting fraction.

  20. Comparison between water and ethanol wet bonding of resin composite to root canal dentin.

    Science.gov (United States)

    Sauro, Salvatore; Di Renzo, Simona; Castagnola, Raffaella; Grande, Nicola M; Plotino, Gianluca; Foschi, Federico; Mannocci, Francesco

    2011-02-01

    To evaluate the bond strength of resin dentin interfaces created with adhesives applied on root dentin using the water wet or ethanol wet bonding technique. The morphology of resin dentin interfaces was evaluated using confocal microscopy. Four experimental resin adhesives (R#A to R#D) and one commercial three-step/etch and rinse adhesive were applied to the root canal dentin of endodontically treated single canal incisors using the water (control) or ethanol wet bonding technique. The ethanol wet bonding substrate was achieved by keeping the root canal immersed in absolute ethanol (100%) for 3 minutes. The root dentin bonded specimens were sectioned into beams, stored in distilled water (24 hours) and finally tested for microtensile bond strengths (tTBS). Additional dentin surfaces were conditioned and bonded as previously described. They were prepared for the microscopy study and finally observed using confocal microscopy. The ethanol wet bonding technique gave higher bond strength values for all the adhesives tested: in Group 1 (water wet bonding technique) no significant difference was found between the resins tested; the only exception being the most hydrophilic Resin #4 showing the highest bond strength values (P < 0.05). In Group 2 (ethanol wet bonding technique) no statistical differences were present between Resin #A and Resin #D. Resin #C showed the highest bond strength values. Confocal microscopy showed better resin diffusion and hybrid layer formation when the ethanol wet bonding was used.

  1. Technical Efficiency of Wet Season Melon Farming

    Directory of Open Access Journals (Sweden)

    Ananti Yekti

    2017-03-01

    Full Text Available Melon is one of high-value horticulture commodity which is cultivated widely in Kulon Progo regency. The nature of agricultural products is heavily dependent on the season, so it causes the prices of agricultural products always fluctuated every time. In wet season the price of agricultural products tends to be more expensive. Melon cultivation in wet season provide an opportunity to earn higher profits than in the dry season. The price of agricultural products tends to be more expensive in wet season, thus melon cultivation in wet season prospectively generate high profits. In order to achieve high profitability, melon farming has to be done efficiently. Objective of this study was to 1 determined the factors that influence melon production in wet season 2 measured technical efficiency of melon farming and 3 identified the factors that influanced technical efficiency. Data collected during April – June 2014. Location determined by multistage cluster sampling. 45 samples of farmers who cultivated melon during wet season obtained based on quota sampling technique. Technical efficiency was measured using Cobb-Douglas Stochastic Frontier. The result reveals that 1 land use, quantity of seed, K fertilizer contributed significantly increasing melon production, while N fertilizer decreased melon production significantly 2 technical efficiency indeces ranged from 0.40 to 0.99, with a mean of  0.77; 3 farmer’s experience gave significant influence to technical efficiency of melon farming in wet season.

  2. Investigation of seasonal thermal flow in a real dam reservoir using 3-D numerical modeling

    Directory of Open Access Journals (Sweden)

    Üneş Fatih

    2015-03-01

    Full Text Available Investigations indicate that correct estimation of seasonal thermal stratification in a dam reservoir is very important for the dam reservoir water quality modeling and water management problems. The main aim of this study is to develop a hydrodynamics model of an actual dam reservoir in three dimensions for simulating a real dam reservoir flows for different seasons. The model is developed using nonlinear and unsteady continuity, momentum, energy and k-ε turbulence model equations. In order to include the Coriolis force effect on the flow in a dam reservoir, Coriolis force parameter is also added the model equations. Those equations are constructed using actual dimensions, shape, boundary and initial conditions of the dam and reservoir. Temperature profiles and flow visualizations are used to evaluate flow conditions in the reservoir. Reservoir flow’s process and parameters are determined all over the reservoir. The mathematical model developed is capable of simulating the flow and thermal characteristics of the reservoir system for seasonal heat exchanges. Model simulations results obtained are compared with field measurements obtained from gauging stations for flows in different seasons. The results show a good agreement with the field measurements.

  3. Mercury bioaccumulation in the food web of Three Gorges Reservoir (China): Tempo-spatial patterns and effect of reservoir management

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jun [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Zhou, Qiong, E-mail: hainan@mail.hzau.edu.cn [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Yuan, Gailing; He, Xugang [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Xie, Ping [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)

    2015-09-15

    Tempo-spatial patterns of mercury bioaccumulation and tropho-dynamics, and the potential for a reservoir effect were evaluated in the Three Gorges Reservoir (TGR, China) from 2011 to 2012, using total mercury concentrations (THg) and stable isotopes (δ{sup 13}C and δ{sup 15}N) of food web components (seston, aquatic invertebrates and fish). Hg concentrations in aquatic invertebrates and fish indicated a significant temporal trend associated with regular seasonal water-level manipulation. This includes water level lowering to allow for storage of water during the wet season (summer); a decrease of water levels from September to June providing a setting for flood storage. Hg concentrations in organisms were the highest after flooding. Higher Hg concentrations in fish were observed at the location farthest from the dam. Hg concentrations in water and sediment were correlated. Compared with the reservoirs of United States and Canada, TGR had lower trophic magnification factors (0.046–0.066), that are explained primarily by organic carbon concentrations in sediment, and the effect of “growth dilution”. Based on comparison before and after the impoundment of TGR, THg concentration in biota did not display an obvious long-term reservoir effect due to (i) short time since inundation, (ii) regular water discharge associated with water-level regulation, and/or (iii) low organic matter content in the sediment. - Highlights: • Hg concentrations were measured in biota of the main stem of 3 Gorges Reservoir. • Fish Hg concentration post-flood period > pre-flood period > flood period. • Fish Hg concentrations were the highest farthest from the dam. • THg in fish 2 years after inundation were the same as before impoundment. • Low biomagnification was ascribed to low DOC content in the sediment.

  4. Characteristics of wet work in nurses.

    Science.gov (United States)

    Jungbauer, F H W; Steenstra, F B; Groothoff, J W; Coenraads, P J

    2005-04-01

    Nursing is known for its high prevalence of hand dermatitis, mainly caused by the intense exposure to wet work in nursing activities. We aimed to study the characteristics of wet work exposure in nursing. Trained observers monitored the duration and frequency of different wet work activities in 45 randomly chosen nurses from different wards during a morning shift, using a method of continuous observation based on labour-observation techniques. Wet work in intensive care units accounted for 24% of the overall morning shift duration, with a frequency of 49 incidents. This was 16% in dialysis wards, with a frequency of 30 incidents, and 9% on regular wards, with a frequency of 39 incidents. The wet work activities had short mean duration cycles. The mean duration of occlusion by gloves was 3.1 min on regular wards and 6.7 min in intensive care units. The characteristics of wet work in nurses differed substantially, depending on the ward. According to the German regulation TRGS 531, our observations classify nursing as a wet work occupation, due to the frequency of wet work rather than its duration. The mean duration of occlusion in our observations was short, which makes an occlusion-induced irritating effect doubtful. Reduction in wet work exposure in nursing on regular wards could focus on the reduction of the frequency of hand-washing and patient-washing. We suggest increasing the use of gloves for patient washing. Although this will increase exposure to occlusion from gloves, it may reduce the frequency of exposure to water and soap by about a quarter.

  5. Reservoir characterization of Pennsylvanian Sandstone Reservoirs. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, M.

    1992-09-01

    This annual report describes the progress during the second year of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description and scale-up procedures; (ii) outcrop investigation; (iii) in-fill drilling potential. The first section describes the methods by which a reservoir can be characterized, can be described in three dimensions, and can be scaled up with respect to its properties, appropriate for simulation purposes. The second section describes the progress on investigation of an outcrop. The outcrop is an analog of Bartlesville Sandstone. We have drilled ten wells behind the outcrop and collected extensive log and core data. The cores have been slabbed, photographed and the several plugs have been taken. In addition, minipermeameter is used to measure permeabilities on the core surface at six inch intervals. The plugs have been analyzed for the permeability and porosity values. The variations in property values will be tied to the geological descriptions as well as the subsurface data collected from the Glen Pool field. The third section discusses the application of geostatistical techniques to infer in-fill well locations. The geostatistical technique used is the simulated annealing technique because of its flexibility. One of the important reservoir data is the production data. Use of production data will allow us to define the reservoir continuities, which may in turn, determine the in-fill well locations. The proposed technique allows us to incorporate some of the production data as constraints in the reservoir descriptions. The technique has been validated by comparing the results with numerical simulations.

  6. Thin wetting film lens-less imaging

    International Nuclear Information System (INIS)

    Allier, C.P.; Poher, V.; Coutard, J.G.; Hiernard, G.; Dinten, J.M.

    2011-01-01

    Lens-less imaging has recently attracted a lot of attention as a compact, easy-to-use method to image or detect biological objects like cells, but failed at detecting micron size objects like bacteria that often do not scatter enough light. In order to detect single bacterium, we have developed a method based on a thin wetting film that produces a micro-lens effect. Compared with previously reported results, a large improvement in signal to noise ratio is obtained due to the presence of a micro-lens on top of each bacterium. In these conditions, standard CMOS sensors are able to detect single bacterium, e.g. E. coli, Bacillus subtilis and Bacillus thuringiensis, with a large signal to noise ratio. This paper presents our sensor optimization to enhance the SNR; improve the detection of sub-micron objects; and increase the imaging FOV, from 4.3 mm 2 to 12 mm 2 to 24 mm 2 , which allows the detection of bacteria contained in 0.5 μl to 4 μl to 10 μl, respectively. (authors)

  7. Catalytic wet oxidation of black liquor

    OpenAIRE

    Viader Riera, Gerard

    2012-01-01

    The major aspects of wet air oxidation and catalytic wet air oxidation have been reviewed in this work paying special attention to the reaction mechanisms, kinetics and the industrial process. In the experimental section a set of heterogeneous catalysts have been tested in the wet oxidation of non-wood black liquor. The oxidation runs were performed batchwise in a laboratory-scale mechanically stirred slurry reactor for 1 h at a temperature of 170°C and total pressure of 12 bar. Pure oxygen w...

  8. Petroleum reservoir data for testing simulation models

    Energy Technology Data Exchange (ETDEWEB)

    Lloyd, J.M.; Harrison, W.

    1980-09-01

    This report consists of reservoir pressure and production data for 25 petroleum reservoirs. Included are 5 data sets for single-phase (liquid) reservoirs, 1 data set for a single-phase (liquid) reservoir with pressure maintenance, 13 data sets for two-phase (liquid/gas) reservoirs and 6 for two-phase reservoirs with pressure maintenance. Also given are ancillary data for each reservoir that could be of value in the development and validation of simulation models. A bibliography is included that lists the publications from which the data were obtained.

  9. A method to implement the reservoir-wave hypothesis using phase-contrast magnetic resonance imaging

    OpenAIRE

    Gray, Robert D.M.; Parker, Kim H.; Quail, Michael A.; Taylor, Andrew M.; Biglino, Giovanni

    2016-01-01

    The reservoir-wave hypothesis states that the blood pressure waveform can be usefully divided into a “reservoir pressure” related to the global compliance and resistance of the arterial system, and an “excess pressure” that depends on local conditions. The formulation of the reservoir-wave hypothesis applied to the area waveform is shown, and the analysis is applied to area and velocity data from high-resolution phase-contrast cardiovascular magnetic resonance (CMR) imaging. A validation stud...

  10. Flow of wet natural pozzolana

    Energy Technology Data Exchange (ETDEWEB)

    Medici, M E; Benegas, O A; Aguirre, F; Baudino, M R [Departamento de Mineria, Universidad Nacional de San Luis, 5700 San Luis (Argentina); Unac, R O; Vidales, A M [INFAP-CONICET, Departamento de Fisica, Universidad Nacional de San Luis, 5700 San Luis (Argentina); Ippolito, I, E-mail: avidales@unsl.edu.a [GMP, CONICET y Facultad de Ingenieria, Universidad de Buenos Aires, 1063 Buenos Aires (Argentina)

    2009-05-01

    We present experimental results on the flow and stability conditions for natural pozzolana, a natural volcanic sand widely used in concrete production. We measured different angles involved in equilibrium conditions for sand piles and relate them to the flux parameters necessary to produce a silo evacuation. We vary some of the geometrical parameters in the silo to inspect the different flux responses of the system. Results are showed as a function of humidity present in the system. In this way, we related critical angles with flux conditions through a silo under different geometric setups and different humidity degrees, thus setting up a basic phase diagram for flux.

  11. Soybean yield in relation to distance from the Itaipu reservoir

    Science.gov (United States)

    de Faria, Rogério Teixeira; Junior, Ruy Casão; Werner, Simone Silmara; Junior, Luiz Antônio Zanão; Hoogenboom, Gerrit

    2016-07-01

    Crops close to small water bodies may exhibit changes in yield if the water mass causes significant changes in the microclimate of areas near the reservoir shoreline. The scientific literature describes this effect as occurring gradually, with higher intensity in the sites near the shoreline and decreasing intensity with distance from the reservoir. Experiments with two soybean cultivars were conducted during four crop seasons to evaluate soybean yield in relation to distance from the Itaipu reservoir and determine the effect of air temperature and water availability on soybean crop yield. Fifteen experimental sites were distributed in three transects perpendicular to the Itaipu reservoir, covering an area at approximately 10 km from the shoreline. The yield gradient between the site closest to the reservoir and the sites farther away in each transect did not show a consistent trend, but varied as a function of distance, crop season, and cultivar. This finding indicates that the Itaipu reservoir does not affect the yield of soybean plants grown within approximately 10 km from the shoreline. In addition, the variation in yield among the experimental sites was not attributed to thermal conditions because the temperature was similar within transects. However, the crop water availability was responsible for higher differences in yield among the neighboring experimental sites related to water stress caused by spatial variability in rainfall, especially during the soybean reproductive period in January and February.

  12. Methane emissions from northern Amazon savanna wetlands and Balbina Reservoir

    Science.gov (United States)

    Kemenes, A.; Belger, L.; Forsberg, B.; Melack, J. M.

    2006-12-01

    To improve estimates of methane emission for the Amazon basin requires information from aquatic environments not represented in the central basin near the Solimoes River, where most of the current data were obtained. We have combined intensive, year-long measurements of methane emission and water levels made in interfluvial wetlands located in the upper Negro basin with calculations of inundation based on a time series of Radarsat synthetic aperature radar images. These grass-dominated savannas emitted methane at an average rate of 18 mg C per m squared per day, a low rate compared to the habitats with floating grasses the occur in the Solimoes floodplains. Reservoirs constructed in the Amazon typically flood forested landscapes and lead to conditions conducive for methane production. The methane is released to the atmosphere from the reservoir and as the water exits the turbines and from the downstream river. Balbina Reservoir near Manaus covers about 2400 km squared along the Uatuma River. Annual averages of measurements of methane emission from the various habitats in the reservoir range from 23 to 64 mg C per m squared per day. Total annual emission from the reservoir is about 58 Gg C. In addition, about 39 Gg C per year are released below the dam, about 50 percent of which is released as the water passes through the turbines. On an annual areal basis, Balbina Reservoir emits 40 Mg C km squared, in contrast to 30 Mg km squared for the Solimoes mainstem floodplain

  13. Sampling from stochastic reservoir models constrained by production data

    Energy Technology Data Exchange (ETDEWEB)

    Hegstad, Bjoern Kaare

    1997-12-31

    When a petroleum reservoir is evaluated, it is important to forecast future production of oil and gas and to assess forecast uncertainty. This is done by defining a stochastic model for the reservoir characteristics, generating realizations from this model and applying a fluid flow simulator to the realizations. The reservoir characteristics define the geometry of the reservoir, initial saturation, petrophysical properties etc. This thesis discusses how to generate realizations constrained by production data, that is to say, the realizations should reproduce the observed production history of the petroleum reservoir within the uncertainty of these data. The topics discussed are: (1) Theoretical framework, (2) History matching, forecasting and forecasting uncertainty, (3) A three-dimensional test case, (4) Modelling transmissibility multipliers by Markov random fields, (5) Up scaling, (6) The link between model parameters, well observations and production history in a simple test case, (7) Sampling the posterior using optimization in a hierarchical model, (8) A comparison of Rejection Sampling and Metropolis-Hastings algorithm, (9) Stochastic simulation and conditioning by annealing in reservoir description, and (10) Uncertainty assessment in history matching and forecasting. 139 refs., 85 figs., 1 tab.

  14. Gravity observations for hydrocarbon reservoir monitoring

    OpenAIRE

    Glegola, M.A.

    2013-01-01

    In this thesis the added value of gravity observations for hydrocarbon reservoir monitoring and characterization is investigated. Reservoir processes and reservoir types most suitable for gravimetric monitoring are identified. Major noise sources affecting time-lapse gravimetry are analyzed. The added value of gravity data for reservoir monitoring and characterization is analyzed within closed-loop reservoir management concept. Synthetic 2D and 3D numerical experiments are performed where var...

  15. Can Extreme Hydrological Events Rejuvenate Reservoir GHG Emissions?

    Science.gov (United States)

    Sherman, B. S.; Ford, P.

    2013-12-01

    Cotter Dam (Canberra, Australia), built in 1912 and enlarged to its current size (4 GL) in 1951, is a water supply reservoir that has recently been enlarged again (to 80 GL) to increase water security. Vegetation consists mainly of regrowth Pinus radiata and scrubby bushland as the catchment recovers from a devastating fire in 2003. Periodic floating chamber measurements of CO2 and CH4 fluxes using a Picarro 1301 CRDS have been undertaken to provide baseline flux measurements against which future GHG emissions can be compared as the dam fills and new soil and vegetation are inundated. After the first survey, drought-breaking rains led to heavy flooding for the first time in more than ten years with more than 80 GL passing through the reservoir during a two-month period. Areal mean CH4 emissions from the reservoir prior to the flooding were low (0.26 × 0.14 mmol m-2 d-1), relatively uniform across the 8 measurement sites, and therefore typical of 'mature' reservoirs. Following the flood, the mean reservoir CH4 emission increased to 6.2 × 1.4 mmol m-2 d-1 with emissions at the upstream end of the reservoir (the deposition zone) approximately 100 times greater (31 × 7.6 mmol m-2 d-1) than emissions near the dam wall (0.28 × 0.019 mmol m-2 d-1), a pattern we consistently observed in two other reservoirs in much wetter and more densely vegetated (subtropical and temperate rainforest) southeast Queensland. Over the following year, there has been a return to more normal runoff conditions, mean emissions have fallen to 2.0 × 0.75 mmol m-2 d-1 and the spatial gradient in emissions has weakened. These results raise important questions regarding the temporal and spatial sampling requirements necessary to provide representative estimates of reservoir methane emissions.

  16. Advancing reservoir operation description in physically based hydrological models

    Science.gov (United States)

    Anghileri, Daniela; Giudici, Federico; Castelletti, Andrea; Burlando, Paolo

    2016-04-01

    Last decades have seen significant advances in our capacity of characterizing and reproducing hydrological processes within physically based models. Yet, when the human component is considered (e.g. reservoirs, water distribution systems), the associated decisions are generally modeled with very simplistic rules, which might underperform in reproducing the actual operators' behaviour on a daily or sub-daily basis. For example, reservoir operations are usually described by a target-level rule curve, which represents the level that the reservoir should track during normal operating conditions. The associated release decision is determined by the current state of the reservoir relative to the rule curve. This modeling approach can reasonably reproduce the seasonal water volume shift due to reservoir operation. Still, it cannot capture more complex decision making processes in response, e.g., to the fluctuations of energy prices and demands, the temporal unavailability of power plants or varying amount of snow accumulated in the basin. In this work, we link a physically explicit hydrological model with detailed hydropower behavioural models describing the decision making process by the dam operator. In particular, we consider two categories of behavioural models: explicit or rule-based behavioural models, where reservoir operating rules are empirically inferred from observational data, and implicit or optimization based behavioural models, where, following a normative economic approach, the decision maker is represented as a rational agent maximising a utility function. We compare these two alternate modelling approaches on the real-world water system of Lake Como catchment in the Italian Alps. The water system is characterized by the presence of 18 artificial hydropower reservoirs generating almost 13% of the Italian hydropower production. Results show to which extent the hydrological regime in the catchment is affected by different behavioural models and reservoir

  17. Stochastic Rotation Dynamics simulations of wetting multi-phase flows

    Science.gov (United States)

    Hiller, Thomas; Sanchez de La Lama, Marta; Brinkmann, Martin

    2016-06-01

    Multi-color Stochastic Rotation Dynamics (SRDmc) has been introduced by Inoue et al. [1,2] as a particle based simulation method to study the flow of emulsion droplets in non-wetting microchannels. In this work, we extend the multi-color method to also account for different wetting conditions. This is achieved by assigning the color information not only to fluid particles but also to virtual wall particles that are required to enforce proper no-slip boundary conditions. To extend the scope of the original SRDmc algorithm to e.g. immiscible two-phase flow with viscosity contrast we implement an angular momentum conserving scheme (SRD+mc). We perform extensive benchmark simulations to show that a mono-phase SRDmc fluid exhibits bulk properties identical to a standard SRD fluid and that SRDmc fluids are applicable to a wide range of immiscible two-phase flows. To quantify the adhesion of a SRD+mc fluid in contact to the walls we measure the apparent contact angle from sessile droplets in mechanical equilibrium. For a further verification of our wettability implementation we compare the dewetting of a liquid film from a wetting stripe to experimental and numerical studies of interfacial morphologies on chemically structured surfaces.

  18. Developing reservoir monthly inflow forecasts using artificial intelligence and climate phenomenon information

    Science.gov (United States)

    Yang, Tiantian; Asanjan, Ata Akbari; Welles, Edwin; Gao, Xiaogang; Sorooshian, Soroosh; Liu, Xiaomang

    2017-04-01

    Reservoirs are fundamental human-built infrastructures that collect, store, and deliver fresh surface water in a timely manner for many purposes. Efficient reservoir operation requires policy makers and operators to understand how reservoir inflows are changing under different hydrological and climatic conditions to enable forecast-informed operations. Over the last decade, the uses of Artificial Intelligence and Data Mining [AI & DM] techniques in assisting reservoir streamflow subseasonal to seasonal forecasts have been increasing. In this study, Random Forest [RF), Artificial Neural Network (ANN), and Support Vector Regression (SVR) are employed and compared with respect to their capabilities for predicting 1 month-ahead reservoir inflows for two headwater reservoirs in USA and China. Both current and lagged hydrological information and 17 known climate phenomenon indices, i.e., PDO and ENSO, etc., are selected as predictors for simulating reservoir inflows. Results show (1) three methods are capable of providing monthly reservoir inflows with satisfactory statistics; (2) the results obtained by Random Forest have the best statistical performances compared with the other two methods; (3) another advantage of Random Forest algorithm is its capability of interpreting raw model inputs; (4) climate phenomenon indices are useful in assisting monthly or seasonal forecasts of reservoir inflow; and (5) different climate conditions are autocorrelated with up to several months, and the climatic information and their lags are cross correlated with local hydrological conditions in our case studies.

  19. The influence of a severe reservoir drawdown on springtime zooplankton and larval fish assemblages in Red Willow Reservoir, Nebraska

    Science.gov (United States)

    DeBoer, Jason A.; Webber, Christa M.; Dixon, Taylor A.; Pope, Kevin L.

    2016-01-01

    Reservoirs can be dynamic systems, often prone to unpredictable and extreme water-level fluctuations, and can be environments where survival is difficult for zooplankton and larval fish. Although numerous studies have examined the effects of extreme reservoir drawdown on water quality, few have examined extreme drawdown on both abiotic and biotic characteristics. A fissure in the dam at Red Willow Reservoir in southwest Nebraska necessitated an extreme drawdown; the water level was lowered more than 6 m during a two-month period, reducing reservoir volume by 76%. During the subsequent low-water period (i.e., post-drawdown), spring sampling (April–June) showed dissolved oxygen concentration was lower, while turbidity and chlorophyll-a concentration were greater, relative to pre-drawdown conditions. Additionally, there was an overall increase in zooplankton density, although there were differences among taxa, and changes in mean size among taxa, relative to pre-drawdown conditions. Zooplankton assemblage composition had an average dissimilarity of 19.3% from pre-drawdown to post-drawdown. The ratio of zero to non-zero catches was greater post-drawdown for larval common carp and for all larval fishes combined, whereas we observed no difference for larval gizzard shad. Larval fish assemblage composition had an average dissimilarity of 39.7% from pre-drawdown to post-drawdown. Given the likelihood that other dams will need repair or replacement in the near future, it is imperative for effective reservoir management that we anticipate the likely abiotic and biotic responses of reservoir ecosystems as these management actions will continue to alter environmental conditions in reservoirs.

  20. The Effect of Wetting on The Course of The Drum Granulation

    Directory of Open Access Journals (Sweden)

    Błaszczyk Michał

    2017-06-01

    Full Text Available This paper presents the results of experimental drum granulation of silica flour with the use of wetting liquids with different values of surface tension. Additionally, different liquid jet breakup and different residual moisture of the bed were applied in the tests. The process was conducted periodically in two stages: wetting and proper granulation, during which no liquid was supplied to the bed. The condition of the granulated material after the period of wetting (particle size distribution and moisture of separate fractions and a change in the particle size distribution during the further conduct of the process (granulation kinetics were determined.

  1. Structure of Wet Specimens in Electron Microscopy

    Science.gov (United States)

    Parsons, D. F.

    1974-01-01

    Discussed are past work and recent advances in the use of electron microscopes for viewing structures immersed in gas and liquid. Improved environmental chambers make it possible to examine wet specimens easily. (Author/RH)

  2. 7 CFR 51.897 - Wet.

    Science.gov (United States)

    2010-01-01

    ... the grapes are wet from moisture from crushed, leaking, or decayed berries or from rain. Grapes which are moist from dew or other moisture condensation such as that resulting from removing grapes from a...

  3. ROE Wet Nitrate Deposition 2011-2013

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 2011 to 2013. Summary data in this indicator were provided by EPA’s...

  4. ROE Wet Nitrate Deposition 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 1989 to 1991. Summary data in this indicator were provided by EPA’s...

  5. ROE Wet Sulfate Deposition 2009-2011

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  6. Wet granular matter a truly complex fluid

    CERN Document Server

    Herminghaus, Stephan

    2013-01-01

    This is a monograph written for the young and advanced researcher who is entering the field of wet granular matter and keen to understand the basic physical principles governing this state of soft matter. It treats wet granulates as an instance of a ternary system, consisting of the grains, a primary, and a secondary fluid. After addressing wetting phenomena in general and outlining the basic facts on dry granular systems, a chapter on basic mechanisms and their effects is dedicated to every region of the ternary phase diagram. Effects of grain shape and roughness are considered as well. Rather than addressing engineering aspects such as existing books on this topic do, the book aims to provide a generalized framework suitable for those who want to understand these systems on a more fundamental basis. Readership: For the young and advanced researcher entering the field of wet granular matter.

  7. 7 CFR 29.3567 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO... damage if treated in the customary manner. (See Rule 22, § 29.3623.) (For extremely wet or watered...

  8. 7 CFR 29.2316 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO... order. Wet applies to any tobacco which is not damaged but which is likely to damage if treated in the...

  9. 7 CFR 29.3077 - Wet (W).

    Science.gov (United States)

    2010-01-01

    ... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO... doubtful-keeping order. Wet applies to any tobacco which is not damaged but which is likely to damage if...

  10. Wet Mechanochemical Processing of Celestine using (NH42CO3

    Directory of Open Access Journals (Sweden)

    Deniz Bingöl

    2017-06-01

    Full Text Available In this study, traditional (univariate method of processing to the wet mechanochemical treatment were applied to obtain both SrCO3 and (NH42SO4 from celestite (SrSO4-(NH42CO3-H2O mixtures in a planetary ball mill. X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and chemical analysis were used to analyze products formed during wet milling. A hydrometallurgical process was carried out to examine milling time, ball to grinding material mass ratio, (NH42CO3 to SrSO4 mole ratio and rotational speed of the mill in a planetary mill. Under optimum conditions, a conversion approaching 100% of SrCO3 was obtained.

  11. Comparison of Wet and Dry Grinding in Electromagnetic Mill

    Directory of Open Access Journals (Sweden)

    Szymon Ogonowski

    2018-03-01

    Full Text Available Comparison of dry and wet grinding process in an electromagnetic mill is presented in this paper. The research was conducted in a batch copper ore grinding. Batch mode allows for precise parametrization and constant repetitive conditions of the experiments. The following key aspects were tested: processing time, feed size, size of the grinding media, mass of the material and graining media, and density of the pulp. The particles size distribution of the product samples was analyzed in the laboratory after each experiment. The paper discusses the experimental results as well as the concept of dry and wet grinding and classification circuits for the electromagnetic mill. The main points of the discussion are the size reduction effectiveness and power consumption of the entire system.

  12. Wet winter pore pressures in railway embankments

    OpenAIRE

    Briggs, Kevin M; Smethurst, Joel A; Powrie, William; O'Brien, Anthony S

    2013-01-01

    This paper demonstrates the influence of extreme wet winter weather on pore water pressures within clay fill railway embankments, using field monitoring data and numerical modelling. Piezometer readings taken across the London Underground Ltd network following the wet winter of 2000/2001 were examined, and showed occurrences of hydrostatic pore water pressure within embankments but also many readings below this. A correlation was found between the maximum pore water pressures and the permeabi...

  13. Determination of Three-Phase Relative Permeabilities under Reservoir Conditions by Hot Water and Steamflood Experiments Détermination de perméabilités relatives tri-phasiques en conditions de réservoir, à partir d'expériences de balayages à l'eau chaude et à la vapeur

    Directory of Open Access Journals (Sweden)

    Quettier L.

    2006-11-01

    Full Text Available In order to help the physical and numerical interpretation of Emeraude's steam pilot, two-phase waterfloods at four temperatures (between 30 and 240°C and a steamflood were performed in the laboratory using the same porous medium (compacted silt and under reservoir conditions. Dynamic isothermal displacements were interpreted with a thermal simulator taking into account capillary end effects. The corresponding oil-water relative permeability curves were obtained by matching observed pressure drop and oil production. Results show that temperature influences the end-point saturations but not the shape of the curves. The steamflood experiment was carried out in an adiabatic core holder. Oil stripping and production of a large amount of CO2 caused by dissolution of carbonates were pointed out. The numerical interpretation of this experiment, by making use of the oil-water relative permeabilities, provided the three-phase oil relative permeability which is an essential datum for numerical interpretation of a steam drive pilot. Then a parameter study was used to quantify the influence of the different mechanisms involved in hot water and steam floods. Dans le but de faciliter l'interprétation physique et numérique du pilote vapeur d' Emeraude, des balayages eau-huile à quatre températures (entre 30 et 240°C et un balayage à la vapeur ont été réalisés au laboratoire. Toutes ces expériences ont été effectuées sur le même milieu poreux (silt compacté et en conditions de réservoir. Les déplacements bi-phasiques isothermes, en écoulement transitoire, ont été interprétés avec un modèle numérique thermique qui prend en compte les effets capillaires aux extrémités de l'échantillon. Les courbes de perméabilités relatives dynamiques eau-huile sont déterminées par calage, sur les courbes expérimentales, de la différence de pression et de la production d'huile simulées. Les résultats montrent que la température influe sur les

  14. On the evaluation of steam assisted gravity drainage in naturally fractured oil reservoirs

    Directory of Open Access Journals (Sweden)

    Seyed Morteza Tohidi Hosseini

    2017-06-01

    Full Text Available Steam Assisted Gravity Drainage (SAGD as a successful enhanced oil recovery (EOR process has been applied to extract heavy and extra heavy oils. Huge amount of global heavy oil resources exists in carbonate reservoirs which are mostly naturally fractured reservoirs. Unlike clastic reservoirs, few studies were carried out to determine the performance of SAGD in carbonate reservoirs. Even though SAGD is a highly promising technique, several uncertainties and unanswered questions still exist and they should be clarified for expansion of SAGD methods to world wide applications especially in naturally fractured reservoirs. In this communication, the effects of some operational and reservoir parameters on SAGD processes were investigated in a naturally fractured reservoir with oil wet rock using CMG-STARS thermal simulator. The purpose of this study was to investigate the role of fracture properties including fracture orientation, fracture spacing and fracture permeability on the SAGD performance in naturally fractured reservoirs. Moreover, one operational parameter was also studied; one new well configuration, staggered well pair was evaluated. Results indicated that fracture orientation influences steam expansion and oil production from the horizontal well pairs. It was also found that horizontal fractures have unfavorable effects on oil production, while vertical fractures increase the production rate for the horizontal well. Moreover, an increase in fracture spacing results in more oil production, because in higher fracture spacing model, steam will have more time to diffuse into matrices and heat up the entire reservoir. Furthermore, an increase in fracture permeability results in process enhancement and ultimate recovery improvement. Besides, diagonal change in the location of injection wells (staggered model increases the recovery efficiency in long-term production plan.

  15. Reservoir-induced seismicity at Castanhao reservoir, NE Brazil

    Science.gov (United States)

    Nunes, B.; do Nascimento, A.; Ferreira, J.; Bezerra, F.

    2012-04-01

    Our case study - the Castanhão reservoir - is located in NE Brazil on crystalline rock at the Borborema Province. The Borborema Province is a major Proterozoic-Archean terrain formed as a consequence of convergence and collision of the São Luis-West Africa craton and the São Francisco-Congo-Kasai cratons. This reservoir is a 60 m high earth-filled dam, which can store up to 4.5 billion m3 of water. The construction begun in 1990 and finished in October 2003.The first identified reservoir-induced events occurred in 2003, when the water level was still low. The water reached the spillway for the first time in January 2004 and, after that, an increase in seismicity occured. The present study shows the results of a campaign done in the period from November 19th, 2009 to December 31th, 2010 at the Castanhão reservoir. We deployed six three-component digital seismographic station network around one of the areas of the reservoir. We analyzed a total of 77 events which were recorded in at least four stations. To determine hypocenters and time origin, we used HYPO71 program (Lee & Lahr, 1975) assuming a half-space model with following parameters: VP= 5.95 km/s and VP/VS=1.73. We also performed a relocation of these events using HYPODD (Waldhauser & Ellsworth, 2000) programme. The input data used we used were catalogue data, with all absolute times. The results from the spatio-temporal suggest that different clusters at different areas and depths are triggered at different times due to a mixture of: i - pore pressure increase due to diffusion and ii - increase of pore pressure due to the reservoir load.

  16. Allergenic Ingredients in Personal Hygiene Wet Wipes.

    Science.gov (United States)

    Aschenbeck, Kelly A; Warshaw, Erin M

    Wet wipes are a significant allergen source for anogenital allergic contact dermatitis. The aim of the study was to calculate the frequency of potentially allergenic ingredients in personal hygiene wet wipes. Ingredient lists from brand name and generic personal hygiene wet wipes from 4 large retailers were compiled. In the 54 personal hygiene wet wipes evaluated, a total of 132 ingredients were identified (average of 11.9 ingredients per wipe). The most common ingredients were Aloe barbadensis (77.8%), citric acid (77.8%), fragrance (72.2%), sorbic acid derivatives (63.0%), tocopherol derivatives (63.0%), glycerin (59.3%), phenoxyethanol (55.6%), disodium cocoamphodiacetate (53.7%), disodium ethylenediaminetetraacetic acid (EDTA) (42.6%), propylene glycol (42.6%), iodopropynyl butylcarbamate (40.7%), chamomile extracts (38.9%), sodium benzoate (35.2%), bronopol (22.2%), sodium citrate (22.2%), lanolin derivatives (20.4%), parabens (20.4%), polyethylene glycol derivatives (18.5%), disodium phosphate (16.7%), dimethylol dimethyl hydantoin (DMDM) (14.8%), and cocamidopropyl propylene glycol (PG)-dimonium chloride phosphate (11.1%). Of note, methylisothiazolinone (5.6%) was uncommon; methylchloroisothiazolinone was not identified in the personal hygiene wet wipes examined. There are many potential allergens in personal hygiene wet wipes, especially fragrance and preservatives.

  17. Reactive species generated during wet chemical etching of silicon in HF/HNO3 mixtures.

    Science.gov (United States)

    Steinert, Marco; Acker, Jörg; Krause, Matthias; Oswald, Steffen; Wetzig, Klaus

    2006-06-15

    The role of intermediate species generated during wet chemical etching of silicon in a HF-rich HF/HNO3 mixture was studied by spectroscopic and analytical methods at 1 degrees C. The intermediate N2O3 was identified by its cobalt blue color and the characteristic features in its UV-vis and Raman spectra. Furthermore, a complex N(III) species (3NO+.NO3-) denoted as [N4O6(2+)] is observed in these solutions. The time-dependent decay of the N(III) intermediates, mainly by their oxidation at the liquid-air interface, serves as a precondition for the study of the etch rate as function of the intermediate concentration measured by Raman spectroscopy. From a linear relationship between etch rate and [N4O6(2+)] concentration, NO+ is considered to be a reactive species in the rate-limiting step. This step is attributed to the oxidation of permanent existing Si-H bonds at the silicon surface by the reactive NO+ species. N2O3 serves as a reservoir for the generation of NO+ leading to a complete coverage of the silicon surface with reactive species at high intermediate concentrations. As long as this condition is valid (plateau region), the etch rate is constant and yields a smooth silicon surface upon completion of the etching. If the N2O3 concentration is insufficient to ensure a coverage of the Si surface by NO+, the etch rate decreases linearly with the N2O3 concentration and results in a roughening of the etched silicon surface (slope region).

  18. Data Integration for the Generation of High Resolution Reservoir Models

    Energy Technology Data Exchange (ETDEWEB)

    Albert Reynolds; Dean Oliver; Gaoming Li; Yong Zhao; Chaohui Che; Kai Zhang; Yannong Dong; Chinedu Abgalaka; Mei Han

    2009-01-07

    The goal of this three-year project was to develop a theoretical basis and practical technology for the integration of geologic, production and time-lapse seismic data in a way that makes best use of the information for reservoir description and reservoir performance predictions. The methodology and practical tools for data integration that were developed in this research project have been incorporated into computational algorithms that are feasible for large scale reservoir simulation models. As the integration of production and seismic data require calibrating geological/geostatistical models to these data sets, the main computational tool is an automatic history matching algorithm. The following specific goals were accomplished during this research. (1) We developed algorithms for calibrating the location of the boundaries of geologic facies and the distribution of rock properties so that production and time-lapse seismic data are honored. (2) We developed and implemented specific procedures for conditioning reservoir models to time-lapse seismic data. (3) We developed and implemented algorithms for the characterization of measurement errors which are needed to determine the relative weights of data when conditioning reservoir models to production and time-lapse seismic data by automatic history matching. (4) We developed and implemented algorithms for the adjustment of relative permeability curves during the history matching process. (5) We developed algorithms for production optimization which accounts for geological uncertainty within the context of closed-loop reservoir management. (6) To ensure the research results will lead to practical public tools for independent oil companies, as part of the project we built a graphical user interface for the reservoir simulator and history matching software using Visual Basic.

  19. Climate Change Assessment of Precipitation in Tandula Reservoir System

    Science.gov (United States)

    Jaiswal, Rahul Kumar; Tiwari, H. L.; Lohani, A. K.

    2018-02-01

    The precipitation is the principle input of hydrological cycle affect availability of water in spatial and temporal scale of basin due to widely accepted climate change. The present study deals with the statistical downscaling using Statistical Down Scaling Model for rainfall of five rain gauge stations (Ambagarh, Bhanpura, Balod, Chamra and Gondli) in Tandula, Kharkhara and Gondli reservoirs of Chhattisgarh state of India to forecast future rainfall in three different periods under SRES A1B and A2 climatic forcing conditions. In the analysis, twenty-six climatic variables obtained from National Centers for Environmental Prediction were used and statistically tested for selection of best-fit predictors. The conditional process based statistical correlation was used to evolve multiple linear relations in calibration for period of 1981-1995 was tested with independent data of 1996-2003 for validation. The developed relations were further used to predict future rainfall scenarios for three different periods 2020-2035 (FP-1), 2046-2064 (FP-2) and 2081-2100 (FP-3) and compared with monthly rainfalls during base period (1981-2003) for individual station and all three reservoir catchments. From the analysis, it has been found that most of the rain gauge stations and all three reservoir catchments may receive significant less rainfall in future. The Thiessen polygon based annual and seasonal rainfall for different catchments confirmed a reduction of seasonal rainfall from 5.1 to 14.1% in Tandula reservoir, 11-19.2% in Kharkhara reservoir and 15.1-23.8% in Gondli reservoir. The Gondli reservoir may be affected the most in term of water availability in future prediction periods.

  20. Isotopic insights into microbial sulfur cycling in oil reservoirs

    Directory of Open Access Journals (Sweden)

    Christopher G Hubbard

    2014-09-01

    Full Text Available Microbial sulfate reduction in oil reservoirs (biosouring is often associated with secondary oil production where seawater containing high sulfate concentrations (~28 mM is injected into a reservoir to maintain pressure and displace oil. The sulfide generated from biosouring can cause corrosion of infrastructure, health exposure risks, and higher production costs. Isotope monitoring is a promising approach for understanding microbial sulfur cycling in reservoirs, enabling early detection of biosouring, and understanding the impact of souring. Microbial sulfate reduction is known to result in large shifts in the sulfur and oxygen isotope compositions of the residual sulfate, which can be distinguished from other processes that may be occurring in oil reservoirs, such as precipitation of sulfate and sulfide minerals. Key to the success of this method is using the appropriate isotopic fractionation factors for the conditions and processes being monitored. For a set of batch incubation experiments using a mixed microbial culture with crude oil as the electron donor, we measured a sulfur fractionation factor for sulfate reduction of -30‰. We have incorporated this result into a simplified 1D reservoir reactive transport model to highlight how isotopes can help discriminate between biotic and abiotic processes affecting sulfate and sulfide concentrations. Modeling results suggest that monitoring sulfate isotopes can provide an early indication of souring for reservoirs with reactive iron minerals that can remove the produced sulfide, especially when sulfate reduction occurs in the mixing zone between formation waters containing elevated concentrations of volatile fatty acids and injection water containing elevated sulfate. In addition, we examine the role of reservoir thermal, geochemical, hydrological, operational and microbiological conditions in determining microbial souring dynamics and hence the anticipated isotopic signatures.

  1. Identification of Environment Chase in Surround of Sermo Reservoir; and the Influence Possibility for Function and at the Age of Reservoi

    Directory of Open Access Journals (Sweden)

    Sudarmadji Sudarmadji

    2004-01-01

    Full Text Available Sermo reservoir is the only one belongs to Yogyakarta Special Province; it is relatively a new reservoir with the area of 1.9 kilometer square and its capacity of 25 million cubic meter: It started to operate since 1996 as flood control, irigation, water supply, tourism and fishery purposes. As a reservoir it could be considered to be a manmade lake, as its condition nearly similar to a lake. Since it operated (even during construction period there were some significant environmental changes within the reservoir and in the area around the reservoir due to the human activities. These changes could threat the sustainability of the reservoir itself This research aims to identiflr the human activities living around the reservoir and visitors coming to the area, and to evaluate the potensial of the activities to produce wastes which is discharging in into the reservoir; which may threat the sustainability of the reservoir: The observatorium in the field has been conducted in the area of the reservoir and its sorrounding. I t was firund fiom the observation that activities o f fishery using net (karamba, tourism altogether with its facilities, land use around the reservoir for agriculture purposes, mining of class C ore, have given a lot of contribution to wastes (liquid and solids and sediments into the reservoir: Those activities may cause water quality of the reservoir lo decrease as well as reducing the reservoir depth. Those situation was observed in the northern and north western parts of the reservoir Water quality degradation of the reservoir may threat reservoir as source of domestic water supply, while the sedimentation may reduce the life time of the reservoir The fishery and tourism activities was estimated as a main cause of water quality degradation, beside agricultural and domestic wastes originated from sattlement area around the reservoir: Sediments coming into the reservoir are derived fiom transported and movement of

  2. Wettability of Oil-Producing Reservoir Rocks as Determined from X-ray Photoelectron Spectroscopy

    Science.gov (United States)

    Toledo; Araujo; Leon

    1996-11-10

    Wettability has a dominant effect in oil recovery by waterflooding and in many other processes of industrial and environmental interest. Recently, the suggestion has been made that surface science analytical techniques (SSAT) could be used to rapidly determine the wettability of reservoir materials. Here, we bring the capability of X-ray photoelectron spectroscopy (XPS) to bear on the wettability evaluation of producing reservoir rocks. For a suite of freshly exposed fracture surfaces of rocks we investigate the relationship between wettability and surface composition as determined from XPS. The classical wettability index as measured with the Amott-Harvey test is used here as an indicator of the wettability of natural sandstones. The XPS spectra of oil-wet surfaces of rocks reveal the existence of organic carbon and also of an "organic" silicon species, of the kind Si-CH relevant to silanes, having a well-defined binding energy which differs from that of the Si-O species of mineral grains. We provide quantifiable evidence that chemisorbed organic material on the pore surfaces defines the oil-wetting character of various reservoir sandstones studied here which on a mineralogic basis are expected to be water-wet. This view is supported by a strong correlation between C content of pore surfaces and rock wettability. The results also suggest a correlation between organic silicon content on the pore surfaces and rock hydrophobicity.

  3. Effects of Dry and Wet Sieving of Soil on Identification and Interpretation of Microbial Community Composition

    OpenAIRE

    Blaud, A.; Menon, M.; van der Zaan, B.; Lair, G.J.; Banwart, S.

    2016-01-01

    Soil aggregates are microhabitats for microorganisms, and directly influence microorganisms that live within and are influenced by microorganisms in return. Two methods are used to isolate soil aggregates by their size: dry sieving (sieving air-dried soil) and wet sieving (sieving soil in water). Wet-sieving methods are generally considered to represent separation of aggregate classes that are stable to physical disaggregation in water, a condition considered favorable for protecting soil str...

  4. Soil Wetness Influences Log Skidding

    Science.gov (United States)

    William N. Darwin

    1960-01-01

    One of the least explored variables in timber harvesting is the effect of ground conditions on log production . The Southern Hardwoods Laboratory is studying this variable and its influence on performance of skidding vehicles in Southern bottom lands. The test reported here was designed to evaluate the effects of bark features on skidding coefficients, but it also...

  5. Reservoir-induced Alterations in Flood Seasonality: Patterns, Processes, and Implications

    Science.gov (United States)

    Abeshu, G. W.; Li, H. Y.; Yigzaw, W.; Hejazi, M. I.; Tang, J.; Demissie, Y.

    2017-12-01

    Reservoirs are by far the most significant human activities that are imposing hydrologic alterations, specifically related to extreme flow conditions. This study presents the effects of reservoir regulation on flood seasonality in different hydrologic and climate settings across the contiguous United States. The data employed consists of reservoir information from the National Inventory of Dams (NID) and Global Reservoir and Dam (GRanD) database along with USGS stream flow data for pre- and post-impoundment periods. A new flood seasonality index was developed with circular statistics to reveal any significant shifts in flood timing between pre- and post-impoundments periods at each USGS station. Reservoir Impact Index (RII) was developed as a function of storage capacity and mean annual streamflow to quantify the regulation effects of reservoirs on flood seasonality. Process understanding of how reservoir regulation affects flow seasonality was analyzed based on RII using simple but physically-based reservoir models with different degrees of complexity, e.g., simple linear and hedging models. Results indicate that the shift in seasonality of annual maximum flood (AMF) at downstream generally increases with increasing RII, given that reservoir has enough storage to regulate the flood. The process modeling results also imply that reservoir state prior to the occurrence of AMF, antecedent climatic patterns and catchment state affect the shift in AMF arrival at downstream. These findings will help improve the ability to examine issues connected to flood frequency characteristics including nutrient delivery, sediment load and stream temperature shifts at downstream of dams.

  6. A Study of Sedimentation at the River Estuary on the Change of Reservoir Storage

    Directory of Open Access Journals (Sweden)

    Iskahar

    2018-01-01

    Full Text Available Estuary of the river that leads to the reservoir has characteristics include: relatively flat, there is a change in the increase of wet cross-sectional area and backwater. The backwater will cause the flow velocity to be reduced, so that the grains of sediment with a certain diameter carried by the flow will settle in the estuary of the river. The purpose of this research is to know the distribution and sedimentation pattern at the river estuary that leads to the reservoir with the change of water level in the reservoir storage, so the solution can be found to remove / reduce sediment before entering the reservoir. The method used is the experimental, by making the physical model of the river estuary leading to the reservoir. This study expects a solution to reduce sedimentation, so that sedimentation can be removed / minimized before entering the reservoir. This research tries to apply bypass channel to reduce the sedimentation at the river estuary. Bypass channels can be applied to overcome sedimentation at the river estuary, but in order for the sediment to be removed optimally, it is necessary to modify the mouth of bypass channel and channel angle.

  7. A Study of Sedimentation at the River Estuary on the Change of Reservoir Storage

    Science.gov (United States)

    Iskahar; Suripin; Isdiyana

    2018-02-01

    Estuary of the river that leads to the reservoir has characteristics include: relatively flat, there is a change in the increase of wet cross-sectional area and backwater. The backwater will cause the flow velocity to be reduced, so that the grains of sediment with a certain diameter carried by the flow will settle in the estuary of the river. The purpose of this research is to know the distribution and sedimentation pattern at the river estuary that leads to the reservoir with the change of water level in the reservoir storage, so the solution can be found to remove / reduce sediment before entering the reservoir. The method used is the experimental, by making the physical model of the river estuary leading to the reservoir. This study expects a solution to reduce sedimentation, so that sedimentation can be removed / minimized before entering the reservoir. This research tries to apply bypass channel to reduce the sedimentation at the river estuary. Bypass channels can be applied to overcome sedimentation at the river estuary, but in order for the sediment to be removed optimally, it is necessary to modify the mouth of bypass channel and channel angle.

  8. Molecular dynamics of wetting layer formation and forced water invasion in angular nanopores with mixed wettability

    Energy Technology Data Exchange (ETDEWEB)

    Sedghi, Mohammad, E-mail: msedghi@uwyo.edu; Piri, Mohammad; Goual, Lamia [Department of Chemical and Petroleum Engineering, University of Wyoming, 1000 East University Avenue, Laramie, Wyoming 82071 (United States)

    2014-11-21

    The depletion of conventional hydrocarbon reservoirs has prompted the oil and gas industry to search for unconventional resources such as shale gas/oil reservoirs. In shale rocks, considerable amounts of hydrocarbon reside in nanoscale pore spaces. As a result, understanding the multiphase flow of wetting and non-wetting phases in nanopores is important to improve oil and gas recovery from these formations. This study was designed to investigate the threshold capillary pressure of oil and water displacements in a capillary dominated regime inside nanoscale pores using nonequilibrium molecular dynamics (NEMD) simulations. The pores have the same cross-sectional area and volume but different cross-sectional shapes. Oil and water particles were represented with a coarse grained model and the NEMD simulations were conducted by assigning external pressure on an impermeable piston. Threshold capillary pressures were determined for the drainage process (water replaced by oil) in different pores. The molecular dynamics results are in close agreements with calculations using the Mayer-Stowe-Princen (MS-P) method which has been developed on the premise of energy balance in thermodynamic equilibrium. After the drainage simulations, a change in wall particles’ wettability from water-wet to oil-wet was implemented based on the final configuration of oil and water inside the pore. Waterflooding simulations were then carried out at the threshold capillary pressure. The results show that the oil layer formed between water in the corner and in the center of the pore is not stable and collapses as the simulation continues. This is in line with the predictions from the MS-P method.

  9. Ecological and floristic characteristics of higher aquatic plants in Volgograd reservoir

    Directory of Open Access Journals (Sweden)

    Kochetkova Anna Igorevna

    2016-12-01

    Full Text Available In this paper the long-term gydro-botanical studies of Volgograd reservoir were analyzed. Flora in different parts of the reservoir, located in Volgograd and Saratov regions was compared. In the floristic investigations, several species of flora, rare in Volgograd region and previously not noted were revealed. The regularities in the floristic composition changes depending on the amplification of climate aridity and features of the hydrological regime of the Volgograd reservoir were determined. Unstable hydrological conditions in the reservoir contribute to the emergence of new free habitats, which are so necessary for the spread and establishment of different plants, including new invasive ones and formed hybrids.

  10. A numerical investigation of combined heat storage and extraction in deep geothermal reservoirs

    DEFF Research Database (Denmark)

    Major, Márton; Poulsen, Søren Erbs; Balling, Niels

    2018-01-01

    Heat storage capabilities of deep sedimentary geothermal reservoirs are evaluated through numerical model simulations. We combine storage with heat extraction in a doublet well system when storage phases are restricted to summer months. The effects of stored volume and annual repetition on energy...... efficiency. Additional simulations concerning pressure build-up in the reservoir are carried out to show that safety levels may not be reached. Reservoir characteristics are inspired by Danish geothermal conditions, but results are assumed to have more general validity. Thus, deep sedimentary reservoirs...

  11. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-01-01

    Infill drilling if wells on a uniform spacing without regard to reservoir performance and characterization foes not optimize reservoir development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. New and emerging technologies, such as geostatistical modeling, rigorous decline curve analysis, reservoir rock typing, and special core analysis can be used to develop a 3-D simulation model for prediction of infill locations.

  12. Cloud computing and Reservoir project

    International Nuclear Information System (INIS)

    Beco, S.; Maraschini, A.; Pacini, F.; Biran, O.

    2009-01-01

    The support for complex services delivery is becoming a key point in current internet technology. Current trends in internet applications are characterized by on demand delivery of ever growing amounts of content. The future internet of services will have to deliver content intensive applications to users with quality of service and security guarantees. This paper describes the Reservoir project and the challenge of a reliable and effective delivery of services as utilities in a commercial scenario. It starts by analyzing the needs of a future infrastructure provider and introducing the key concept of a service oriented architecture that combines virtualisation-aware grid with grid-aware virtualisation, while being driven by business service management. This article will then focus on the benefits and the innovations derived from the Reservoir approach. Eventually, a high level view of Reservoir general architecture is illustrated.

  13. Twenty years of water-quality studies in the Cheney Reservoir Watershed, Kansas, 1996-2016

    Science.gov (United States)

    Graham, Jennifer L.; Foster, Guy M.; Kramer, Ariele R.

    2017-03-31

    Since 1996, the U.S. Geological Survey (USGS), in cooperation with the City of Wichita, has done studies in the Cheney Reservoir watershed to understand environmental effects on water-quality conditions. Early studies (1996–2001) determined subwatershed sources of contaminants, nutrient and sediment loading to Cheney Reservoir, changes in reservoir sediment quality over time, and watershed sources of phosphorus. Later studies (2001–present) focused on nutrient and sediment concentrations and mass transport from the watershed; the presence of cyanobacteria, cyanotoxins, and taste-and-odor compounds in the reservoir; and development of regression models for real-time computations of water-quality constituents of interest that may affect drinking-water treatment. This fact sheet summarizes key results from studies done by the USGS during 1996–2016 in the Cheney Reservoir watershed and Cheney Reservoir.

  14. Fish assemblage in a dammed tropical river: an analysis along the longitudinal and temporal gradients from river to reservoir

    Directory of Open Access Journals (Sweden)

    Bianca de Freitas Terra

    Full Text Available We analysed changes in the fish assemblage structure along a longitudinal gradient of the Paraíba do Sul River and Funil Reservoir. We tested the hypothesis that shifts from lotic to lentic environment affect the richness and structure of the assemblage which are modulated by seasonal rainfall changes. Standardised monthly samplings were carried out from October 2006 to September 2007 in four zones: 1 river upstream from the reservoir; 2 upper part of the reservoir; 3 lower part of the reservoir, and 4 river downstream from the reservoir. Fishes were caught using gillnets deployed for 15 hours. We collected a total of 4550 specimens, representing 35 species and 5 orders. The highest richness and diversity were recorded in zone 2, the transitional zone between river and reservoir. In this ecotone, lotic and lentic species overlap. Greater abundance and biomass was recorded in the river upstream from the reservoir (zone 1; however, there are no differences between the zones in the structure of assemblages during the wet season. During the dry season, the assemblage structure is more differentiated between zones, although no differences in abundance and biomass occur. The seasonal flow of the river is the major driving factor to influence the fish assemblage structure along the longitudinal gradient from the river to the reservoir.

  15. Reservoir effects in radiocarbon dating

    International Nuclear Information System (INIS)

    Head, M.J.

    1997-01-01

    Full text: The radiocarbon dating technique depends essentially on the assumption that atmospheric carbon dioxide containing the cosmogenic radioisotope 14 C enters into a state of equilibrium with all living material (plants and animals) as part of the terrestrial carbon cycle. Terrestrial reservoir effects occur when the atmospheric 14 C signal is diluted by local effects where systems depleted in 14 C mix with systems that are in equilibrium with the atmosphere. Naturally, this can occur with plant material growing close to an active volcano adding very old CO 2 to the atmosphere (the original 14 C has completely decayed). It can also occur in highly industrialised areas where fossil fuel derived CO 2 dilutes the atmospheric signal. A terrestrial reservoir effect can occur in the case of fresh water shells living in rivers or lakes where there is an input of ground water from springs or a raising of the water table. Soluble bicarbonate derived from the dissolution of very old limestone produces a 14 C dilution effect. Land snail shells and stream carbonate depositions (tufas and travertines) can be affected by a similar mechanism. Alternatively, in specific cases, these reservoir effects may not occur. This means that general interpretations assuming quantitative values for these terrestrial effects are not possible. Each microenvironment associated with samples being analysed needs to be evaluated independently. Similarly, the marine environment produces reservoir effects. With respect to marine shells and corals, the water depth at which carbonate growth occurs can significantly affect quantitative 14 C dilution, especially in areas where very old water is uplifted, mixing with top layers of water that undergo significant exchange with atmospheric CO 2 . Hence, generalisations with respect to the marine reservoir effect also pose problems. These can be exacerbated by the mixing of sea water with either terrestrial water in estuaries, or ground water where

  16. Laboratory monitoring of CO2 migration within brine-saturated reservoir rock though complex electrical impedance

    NARCIS (Netherlands)

    Kirichek, O.; Ghose, R.; Heller, H.K.J.

    2013-01-01

    We investigate the ability of complex electrical measurements to monitor the CO2 front propagation within brine-saturated reservoir rock. A laboratory facility has been developed to perform CO2-brine substitution experiments under reservoir conditions. In the present study, CO2 is injected into a

  17. Sedimentological and Geomorphological Effects of Reservoir Flushing: The Cachi Reservoir, Costa Rica, 1996

    DEFF Research Database (Denmark)

    Brandt, Anders; Swenning, Joar

    1999-01-01

    Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs......Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs...

  18. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

    Energy Technology Data Exchange (ETDEWEB)

    P. K. Pande

    1998-10-29

    Initial drilling of wells on a uniform spacing, without regard to reservoir performance and characterization, must become a process of the past. Such efforts do not optimize reservoir development as they fail to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. These reservoirs are typically characterized by: o Large, discontinuous pay intervals o Vertical and lateral changes in reservoir properties o Low reservoir energy o High residual oil saturation o Low recovery efficiency

  19. SIRIU RESERVOIR, BUZAU RIVER (ROMANIA

    Directory of Open Access Journals (Sweden)

    Daniel Constantin DIACONU

    2008-06-01

    Full Text Available Siriu reservoir, owes it`s creation to the dam built on the river Buzau, in the town which bears the same name. The reservoir has a hydro energetic role, to diminish the maximum flow and to provide water to the localities below. The partial exploitation of the lake, began in 1984; Since that time, the initial bed of the river began to accumulate large quantities of alluvia, reducing the retention capacity of the lake, which had a volume of 125 million m3. The changes produced are determined by many topographic surveys at the bottom of the lake.

  20. Introduction to the appropriate-stimulation degree of hydraulic fracture networks in shale gas reservoirs

    Directory of Open Access Journals (Sweden)

    Yuzhang Liu

    2018-02-01

    Full Text Available Due to the limitation of actual shale gas reservoir conditions and fracturing technologies, artificial fracture networks are different greatly even in the same or similar stimulated reservoir volume. Deviations and even faults occur in evaluation and cognition if only the stimulated reservoir volume (SRV is used to characterize and evaluate the effect of stimulation. In this paper, the spatial distribution of artificial fractures and natural fractures and the internal pressure state and degree of reserve recovery of stimulated shale gas reservoirs were studied by means of artificial fracture propagation numerical simulation and production numerical simulation. And three concepts were proposed, i.e., shale gas fracture network, ideal fracture network and appropriate-stimulation degree of fracture network. The study results indicate that, at the end of reservoir development, target zones can be classified into three types (i.e., relatively appropriate stimulation zone, transitional stimulation zone, and uncompleted stimulation zone according to the recovery degree and production time of stimulated reservoirs; and that the final morphologic parameter of fracture networks and the reservoir characteristic are two main factors affecting the appropriate-stimulation degree of fracture networks. As for a specific gas reservoir, the orientation, length, conduction, height and spatial location of its fracture network are the main factors influencing its appropriate-stimulation degree if the well trajectory is set. The proposal of the theory on the appropriate-stimulation degree of hydraulic fracture networks in shale gas reservoir enriches the theoretical system of shale reservoir stimulation technology, and it can be used as the reference for characterizing the fracture systems in other unconventional reservoirs, such as tight oil and gas reservoirs. Keywords: Shale gas, Reservoir stimulation, Ideal fracture network, Appropriate-stimulation degree of

  1. Spatially pooled depth-dependent reservoir storage, elevation, and water-quality data for selected reservoirs in Texas, January 1965-January 2010

    Science.gov (United States)

    Burley, Thomas E.; Asquith, William H.; Brooks, Donald L.

    2011-01-01

    The U.S. Geological Survey (USGS), in cooperation with Texas Tech University, constructed a dataset of selected reservoir storage (daily and instantaneous values), reservoir elevation (daily and instantaneous values), and water-quality data from 59 reservoirs throughout Texas. The period of record for the data is as large as January 1965-January 2010. Data were acquired from existing databases, spreadsheets, delimited text files, and hard-copy reports. The goal was to obtain as much data as possible; therefore, no data acquisition restrictions specifying a particular time window were used. Primary data sources include the USGS National Water Information System, the Texas Commission on Environmental Quality Surface Water-Quality Management Information System, and the Texas Water Development Board monthly Texas Water Condition Reports. Additional water-quality data for six reservoirs were obtained from USGS Texas Annual Water Data Reports. Data were combined from the multiple sources to create as complete a set of properties and constituents as the disparate databases allowed. By devising a unique per-reservoir short name to represent all sites on a reservoir regardless of their source, all sampling sites at a reservoir were spatially pooled by reservoir and temporally combined by date. Reservoir selection was based on various criteria including the availability of water-quality properties and constituents that might affect the trophic status of the reservoir and could also be important for understanding possible effects of climate change in the future. Other considerations in the selection of reservoirs included the general reservoir-specific period of record, the availability of concurrent reservoir storage or elevation data to match with water-quality data, and the availability of sample depth measurements. Additional separate selection criteria included historic information pertaining to blooms of golden algae. Physical properties and constituents were water

  2. Performance of a UASB reactor treating coffee wet wastewater

    International Nuclear Information System (INIS)

    Guardia Puebla, Yans; Rodríguez Pérez, Suyén; Janet Jiménez Hernández; Sánchez Girón, Víctor

    2014-01-01

    The present work shows the results obtained in the anaerobic digestion process of coffee wet wastewater processing. An UASB anaerobic reactor was operated in single-stage in mesophilic temperature controlled conditions (37±1ºC). The effect of both organic loading rate (OLR) and hydraulic retention time (HRT) in the anaerobic digestion of coffee wet wastewater was investigated. The OLR values considered in the single-stage UASB reactor varied in a range of 3,6-4,1 kgCOD m-3 d-1 and the HRT stayed in a range of 21,5-15,5 hours. The evaluation results show that the best performance of UASB reactor in single-stage was obtained at OLR of 3,6 kg COD m-3 d-1 with an average value of total and soluble COD removal of 77,2% and 83,4%, respectively, and average methane concentration in biogas of 61%. The present study suggests that the anaerobic digestion is suitable to treating coffee wet wastewater. (author)

  3. Understanding the edge effect in wetting: a thermodynamic approach.

    Science.gov (United States)

    Fang, Guoping; Amirfazli, A

    2012-06-26

    Edge effect is known to hinder spreading of a sessile drop. However, the underlying thermodynamic mechanisms responsible for the edge effect still is not well-understood. In this study, a free energy model has been developed to investigate the energetic state of drops on a single pillar (from upright frustum to inverted frustum geometries). An analysis of drop free energy levels before and after crossing the edge allows us to understand the thermodynamic origin of the edge effect. In particular, four wetting cases for a drop on a single pillar with different edge angles have been determined by understanding the characteristics of FE plots. A wetting map describing the four wetting cases is given in terms of edge angle and intrinsic contact angle. The results show that the free energy barrier observed near the edge plays an important role in determining the drop states, i.e., (1) stable or metastable drop states at the pillar's edge, and (2) drop collapse by liquid spilling over the edge completely or staying at an intermediate sidewall position of the pillar. This thermodynamic model presents an energetic framework to describe the functioning of the so-called "re-entrant" structures. Results show good consistency with the literature and expand the current understanding of Gibbs' inequality condition.

  4. Dynamics of the zooplankton assemblage of Ojirami Reservoir, Edo ...

    African Journals Online (AJOL)

    Zooplankton form an important trophic link between phytoplankton and fish in the aquatic food chain. Investigation was carried out on the zooplankton community of Ojirami, Reservoir, Nigeria, to document the composition, abundance and distribution and their interactions with the physico-chemical conditions. Surface water ...

  5. Wetting films on chemically patterned surfaces.

    Science.gov (United States)

    Karakashev, Stoyan I; Stöckelhuber, Klaus W; Tsekov, Roumen

    2011-11-15

    The behavior of thin wetting films on chemically patterned surfaces was investigated. The patterning was performed by means of imprinting of micro-grid on methylated glass surface with UV-light (λ=184.8 nm). Thus imprinted image of the grid contained hydrophilic cells and hydrophobic bars on the glass surface. For this aim three different patterns of grids were utilized with small, medium and large size of cells. The experiment showed that the drainage of the wetting aqueous films was not affected by the type of surface patterning. However, after film rupturing in the cases of small and medium cells of the patterned grid the liquid from the wetting film underwent fast self-organization in form of regularly ordered droplets covering completely the cells of the grid. The droplets reduced significantly their size upon time due to evaporation. In the cases of the largest cell grid, a wet spot on the place of the imprinted grid was formed after film rupturing. This wet spot disassembled slowly in time. In addition, formation of a periodical zigzag three-phase contact line (TPCL) was observed. This is a first study from the planned series of studies on this topic. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Modeling of Direct Contact Wet Cooling Tower in ETRR-2

    International Nuclear Information System (INIS)

    El Khatib, H.H.; Ismail, A.L.; ElRefaie, M.E.

    2008-01-01

    The Egyptian Testing and Research Reactor no.2 (ETRR-2) was commissioned at 1997 with maximum power 22 MW for research purposes; an induced draft wet cooling tower (counter flow type) was putted in operation in 2003 instead of the first one. Investigations are achieved to evaluate cooling tower performance to guarantee that the cooling tower capable to dissipate heat generated in reactor core. Merkel and Poppe analysis was applied to simulate this cooling tower packing. Merkel analysis was applied to predict water outlet temperature from cooling tower and also to show the effect of ambient conditions on this temperature. Poppe analysis was applied to predict Merkel number which evaluate cooling tower. The Runge-Kutta numerical method was applied to solve the differential equations in this model and an engineering equation solver (EES) is the language used to model the cooling tower. This research illustrates that the cooling tower achieves good performance in various sever ambient condition at maximum operating condition of reactor power. The results show that at severe summer condition of wet bulb temperature equals 24 degree c and tower inlet temperature equals 37 degree c, the outlet water temperature equals 30.4 degree c from cooling tower, while the Merkel number is be found 1.253

  7. Reservoir Sedimentation Based on Uncertainty Analysis

    Directory of Open Access Journals (Sweden)

    Farhad Imanshoar

    2014-01-01

    Full Text Available Reservoir sedimentation can result in loss of much needed reservoir storage capacity, reducing the useful life of dams. Thus, sufficient sediment storage capacity should be provided for the reservoir design stage to ensure that sediment accumulation will not impair the functioning of the reservoir during the useful operational-economic life of the project. However, an important issue to consider when estimating reservoir sedimentation and accumulation is the uncertainty involved in reservoir sedimentation. In this paper, the basic factors influencing the density of sediments deposited in reservoirs are discussed, and uncertainties in reservoir sedimentation have been determined using the Delta method. Further, Kenny Reservoir in the White River Basin in northwestern Colorado was selected to determine the density of deposits in the reservoir and the coefficient of variation. The results of this investigation have indicated that by using the Delta method in the case of Kenny Reservoir, the uncertainty regarding accumulated sediment density, expressed by the coefficient of variation for a period of 50 years of reservoir operation, could be reduced to about 10%. Results of the Delta method suggest an applicable approach for dead storage planning via interfacing with uncertainties associated with reservoir sedimentation.

  8. Zn(II, Mn(II and Sr(II Behavior in a Natural Carbonate Reservoir System. Part I: Impact of Salinity, Initial pH and Initial Zn(II Concentration in Atmospheric Conditions

    Directory of Open Access Journals (Sweden)

    Auffray B.

    2016-07-01

    Full Text Available The sorption of inorganic elements on carbonate minerals is well known in strictly controlled conditions which limit the impact of other phenomena such as dissolution and/or precipitation. In this study, we evidence the behavior of Zn(II (initially in solution and two trace elements, Mn(II and Sr(II (released by carbonate dissolution in the context of a leakage from a CO2 storage site. The initial pH chosen are either equal to the pH of the water-CO2 equilibrium (~ 2.98 or equal to the pH of the water-CO2-calcite system (~ 4.8 in CO2 storage conditions. From this initial influx of liquid, saturated or not with respect to calcite, the batch experiments evolve freely to their equilibrium, as it would occur in a natural context after a perturbation. The batch experiments are carried out on two natural carbonates (from Lavoux and St-Emilion with PCO2 = 10−3.5 bar, with different initial conditions ([Zn(II]i from 10−4 to 10−6 M, either with pure water or 100 g/L NaCl brine. The equilibrium regarding calcite dissolution is confirmed in all experiments, while the zinc sorption evidenced does not always correspond to the two-step mechanism described in the literature. A preferential sorption of about 10% of the concentration is evidenced for Mn(II in aqueous experiments, while Sr(II is more sorbed in saline conditions. This study also shows that this preferential sorption, depending on the salinity, is independent of the natural carbonate considered. Then, the simulations carried out with PHREEQC show that experiments and simulations match well concerning the equilibrium of dissolution and the sole zinc sorption, with log KZn(II ~ 2 in pure water and close to 4 in high salinity conditions. When the simulations were possible, the log K values for Mn(II and Sr(II were much different from those in the literature obtained by sorption in controlled conditions. It is shown that a new conceptual model regarding multiple Trace Elements (TE sorption is

  9. Evaporation from rain-wetted forest in relation to canopy wetness, canopy cover, and net radiation

    NARCIS (Netherlands)

    Klaassen, W.

    2001-01-01

    Evaporation from wet canopies is commonly calculated using E-PM, the Penman-Monteith equation with zero surface resistance. However, several observations show a lower evaporation from rain-wetted forest. Possible causes for the difference between E-PM and experiments are evaluated to provide rules

  10. Advanced methods for the treatment of organic aqueous wastes: wet air oxidation and wet peroxide oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Debellefontaine, Hubert; Chakchouk, Mehrez; Foussard, Jean Noel [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France). Dept. de Genie des Procedes Industriels; Tissot, Daniel; Striolo, Phillipe [IDE Environnement S.A., Toulouse (France)

    1993-12-31

    There is a growing concern about the problems of wastes elimination. Various oxidation techniques are suited for elimination of organic aqueous wastes, however, because of the environmental drawbacks of incineration, liquid phase oxidation should be preferred. `Wet Air Oxidation` and `Wet Peroxide Oxidation`are alternative processes which are discussed in this paper. 17 refs., 13 figs., 4 tabs.

  11. Thermoelastic properties of the Rotokawa Andesite: A geothermal reservoir constraint

    Science.gov (United States)

    Siratovich, P. A.; von Aulock, F. W.; Lavallée, Y.; Cole, J. W.; Kennedy, B. M.; Villeneuve, M. C.

    2015-08-01

    beneficial in reservoir stimulation procedures, but also poses potential risk to wellbore stability, so constraining the conditions at which this can occur can be beneficial to resource utilization.

  12. Data assimilation in reservoir management

    NARCIS (Netherlands)

    Rommelse, J.R.

    2009-01-01

    The research presented in this thesis aims at improving computer models that allow simulations of water, oil and gas flows in subsurface petroleum reservoirs. This is done by integrating, or assimilating, measurements into physics-bases models. In recent years petroleum technology has developed

  13. Reservoirs in the United States

    Science.gov (United States)

    Harbeck, G. Earl

    1948-01-01

    Man has engaged in the control of flowing water since history began. Among his early recorded efforts were reservoirs for muncipal water-supplies constructed near ancient Jerusalem to store water which was brought there in masonry conduits. 1/  Irrigation was practiced in Egypt as early as 2000 B. C. There the "basin system" was used from ancient times until the 19th century. The land was divided , into basins of approximately 40,000 acres, separated by earthen dikes. 2/  Flood waters of the Nile generally inundated the basins through canals, many of which were built by the Pharaohs. Even then the economic consequences of a deficient annual flood were recognized. Lake Maeris, which according to Herodotus was an ancient storage reservoir, is said to have had an area of 30,000 acres. In India, the British found at the time of their occupancy of the Presidency of Madras about 50,000 reservoirs for irrigation, many believed to be of ancient construction. 3/ During the period 115-130 A. D. reservoirs were built to improve the water-supply of Athens. Much has been written concerning the elaborate collection and distribution system built to supply Rome, and parts of it remain to this day as monuments to the engineering skill employed by the Romans in solving the problem of large-scale municipal water-supplies.

  14. Reasons for reservoir effect variability

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2013-01-01

    , aquatic plants and fish from the rivers Alster and Trave range between zero and about 3,000 radiocarbon years. The reservoir age of water DIC depends to a large extent on the origin of the water and is for example correlated with precipitation amounts. These short-term variations are smoothed out in water...

  15. Double barreled wet colostomy: initial experience and literature review.

    Science.gov (United States)

    Salgado-Cruz, Luis; Espin-Basany, Eloy; Vallribera-Valls, Francesc; Sanchez-Garcia, Jose; Jimenez-Gomez, Luis Miguel; Marti-Gallostra, Marc; Garza-Maldonado, Ana

    2014-01-01

    Pelvic exenteration and multivisceral resection in colorectal have been described as a curative and palliative intervention. Urinary tract reconstruction in a pelvic exenteration is achieved in most cases with an ileal conduit of Bricker, although different urinary reservoirs have been described. A retrospective and observational study of six patients who underwent a pelvic exenteration and urinary tract reconstruction with a double barreled wet colostomy (DBWC) was done, describing the preoperative diagnosis, the indication for the pelvic exenteration, the complications associated with the procedure, and the followup in a period of 5 years. A literature review of the case series reported of the technique was performed. Six patients had a urinary tract reconstruction with the DBWC technique, 5 male patients and one female patient. Age range was from 20 to 77 years, with a medium age 53.6 years. The most frequent complication presented was a pelvic abscess in 3 patients (42.85%); all complications could be resolved with a conservative treatment. In the group of our patients with pelvic exenteration and urinary tract reconstruction with a DBWC, it is a safe procedure and well tolerated by the patients, and most of the complications can be resolved with conservative treatment.

  16. Double Barreled Wet Colostomy: Initial Experience and Literature Review

    Directory of Open Access Journals (Sweden)

    Luis Salgado-Cruz

    2014-01-01

    Full Text Available Background. Pelvic exenteration and multivisceral resection in colorectal have been described as a curative and palliative intervention. Urinary tract reconstruction in a pelvic exenteration is achieved in most cases with an ileal conduit of Bricker, although different urinary reservoirs have been described. Methods. A retrospective and observational study of six patients who underwent a pelvic exenteration and urinary tract reconstruction with a double barreled wet colostomy (DBWC was done, describing the preoperative diagnosis, the indication for the pelvic exenteration, the complications associated with the procedure, and the followup in a period of 5 years. A literature review of the case series reported of the technique was performed. Results. Six patients had a urinary tract reconstruction with the DBWC technique, 5 male patients and one female patient. Age range was from 20 to 77 years, with a medium age 53.6 years. The most frequent complication presented was a pelvic abscess in 3 patients (42.85%; all complications could be resolved with a conservative treatment. Conclusion. In the group of our patients with pelvic exenteration and urinary tract reconstruction with a DBWC, it is a safe procedure and well tolerated by the patients, and most of the complications can be resolved with conservative treatment.

  17. Groundwater Salinity Simulation of a Subsurface Reservoir in Taiwan

    Science.gov (United States)

    Fang, H. T.

    2015-12-01

    The subsurface reservoir is located in Chi-Ken Basin, Pescadores (a group islands located at western part of Taiwan). There is no river in these remote islands and thus the freshwater supply is relied on the subsurface reservoir. The basin area of the subsurface reservoir is 2.14 km2 , discharge of groundwater is 1.27×106m3 , annual planning water supplies is 7.9×105m3 , which include for domestic agricultural usage. The annual average temperature is 23.3oC, average moisture is 80~85%, annual average rainfall is 913 mm, but ET rate is 1975mm. As there is no single river in the basin; the major recharge of groundwater is by infiltration. Chi-Ken reservoir is the first subsurface reservoir in Taiwan. Originally, the water quality of the reservoir is good. The reservoir has had the salinity problem since 1991 and it became more and more serious from 1992 until 1994. Possible reason of the salinity problem was the shortage of rainfall or the leakage of the subsurface barrier which caused the seawater intrusion. The present study aimed to determine the leakage position of subsurface barrier that caused the salinity problem. In order to perform the simulation for different possible leakage position of the subsurface reservoir, a Groundwater Modeling System (GMS) is used to define soils layer data, hydro-geological parameters, initial conditions, boundary conditions and the generation of three dimension meshes. A three dimension FEMWATER(Yeh , 1996) numerical model was adopted to find the possible leakage position of the subsurface barrier and location of seawater intrusion by comparing the simulation of different possible leakage with the observations. 1.By assuming the leakage position in the bottom of barrier, the simulated numerical result matched the observation better than the other assumed leakage positions. It showed that the most possible leakage position was at the bottom of the barrier. 2.The research applied three dimension FEMWATER and GMS as an interface

  18. Critical wetting of n-alkanes on water; Mouillage critique des alcanes sur l`eau

    Energy Technology Data Exchange (ETDEWEB)

    Ragil, K.

    1996-10-18

    This study concerns the wetting properties of n-alkanes on water under thermodynamic equilibrium conditions, a problem that is interesting for the petroleum industry as well as for the fundamental understanding of wetting phenomena. An experimental study using ellipsometry reveals that pentane on water undergoes a continuous or critical wetting transition at a temperature equal to 53.1 deg. C. This is the first experimental observation of such a transition, confirming theoretical predictions made on this subject over ten years. This transition is characterized by a continuous and reversible evolution of the thickness of the film of pentane with temperature from a thick (but finite film) to a macroscopic film. The critical wetting transition occurs when the Hamaker constant of the system, which gives the net interaction between the two interfaces bounding the wetting layer of pentane in terms of the van der Waals forces, changes sign. A theoretical approach based on the Cahn-Landau theory, which takes into account long range forces (van der Waals forces), enables us to explain the mechanism of the critical wetting transition and to show that a first-order wetting transition should precede it. Because of their similar dispersive properties, linear alkanes could all be able to show such a succession of transitions. An ellipsometry study performed on a brine/hexane/vapor system confirms that a discontinuous transition from a thin microscopic film to a thick but finite adsorbed film takes place. THis study demonstrates that the wetting of alkanes on water is determined by subtle interplay between short range and long range forces, which can lead to an intermediary state between partial and complete wetting. (author)

  19. Run don't walk: locomotor performance of geckos on wet substrates.

    Science.gov (United States)

    Stark, Alyssa Y; Ohlemacher, Jocelyn; Knight, Ashley; Niewiarowski, Peter H

    2015-08-01

    The gecko adhesive system has been under particular scrutiny for over a decade, as the field has recently attracted attention for its application to bio-inspired design. However, little is known about how the adhesive system behaves in ecologically relevant conditions. Geckos inhabit a variety of environments, many of which are characterized by high temperature, humidity and rain. The van der Waals-based gecko adhesive system should be particularly challenged by wet substrates because water can disrupt the intimate contact necessary for adhesion. While a few previous studies have focused on the clinging ability of geckos on wet substrates, we tested a dynamic performance characteristic, sprint velocity. To better understand how substrate wettability and running orientation affect locomotor performance of multiple species on wet substrates, we measured average sprint velocity of five species of gecko on substrates that were either hydrophilic or intermediately wetting and oriented either vertically or horizontally. Surprisingly, we found no indication that wet substrates impact average sprint velocity over 1 m, and rather, in some species, sprint velocity was increased on wet substrates rather than reduced. When investigating physical characteristics and behavior that may be associated with running on wet substrates, such as total number of stops, slips and wet toes at the completion of a race, we found that there may be habitat-related differences between some species. Our results show that in general, unlike clinging and walking, geckos running along wet substrates suffer no significant loss in locomotor performance over short distances. © 2015. Published by The Company of Biologists Ltd.

  20. Monitoring Reservoirs Using MERIS And LANDSAT Fused Images : A Case Study Of Polyfitos Reservoir - West Macedonia - Greece

    Science.gov (United States)

    Stefouli, M.; Charou, E.; Vasileiou, E.; Stathopoulos, N.; Perrakis, A.

    2012-04-01

    Research and monitoring is essential to assess baseline conditions in reservoirs and their watershed and provide necessary information to guide decision-makers. Erosion and degradation of mountainous areas can lead to gradual aggradation of reservoirs reducing their lifetime. Collected measurements and observations have to be communicated to the managers of the reservoirs so as to achieve a common / comprehensive management of a large watershed and reservoir system. At this point Remote Sensing could help as the remotely sensed data are repeatedly and readily available to the end users. Aliakmon is the longest river in Greece, it's length is about 297 km and the surface of the river basin is 9.210 km2.The flow of the river starts from Northwest of Greece and ends in Thermaikos Gulf. The riverbed is not natural throughout the entire route, because constructed dams restrict water and create artificial lakes, such as lake of Polyfitos, that prevent flooding. This lake is used as reservoir, for covering irrigational water needs and the water is used to produce energy from the hydroelectric plant of Public Power Corporation-PPC. The catchment basin of Polyfitos' reservoir covers an area of 847.76 km2. Soil erosion - degradation in the mountainous watershed of streams of Polyfitos reservoir is taking place. It has been estimated that an annual volume of sediments reaching the reservoir is of the order of 244 m3. Geomatic based techniques are used in processing multiple data of the study area. A data inventory was formulated after the acquisition of topographic maps, compilation of geological and hydro-geological maps, compilation of digital elevation model for the area of interest based on satellite data and available maps. It also includes the acquisition of various hydro-meteorological data when available. On the basis of available maps and satellite data, digital elevation models are used in order to delineate the basic sub-catchments of the Polyfytos basin as well as

  1. Contribution of dust inputs to dissolved organic carbon and water transparency in Mediterranean reservoirs

    Science.gov (United States)

    de Vicente, I.; Ortega-Retuerta, E.; Morales-Baquero, R.; Reche, I.

    2012-12-01

    The Mediterranean reservoirs receive frequent atmospheric Saharan dust inputs with soil-derived organic components mostly during the stratification periods, when run-off inputs are particularly limited. Here, we quantified and optically characterized the water-soluble organic carbon (WSOC) of the (dry and wet) atmospheric deposition in collectors placed near three reservoirs from the western Mediterranean Basin. In addition, we determined the WSOC contribution to the pool of dissolved organic carbon (DOC) in the reservoirs and the influence of dust-derived chromophoric organic components on the water transparency during their stratification periods. We found synchronous dynamics in the WSOC atmospheric inputs among the three collectors and in the DOC concentrations among the three reservoirs. The DOC concentrations and the WSOC atmospheric inputs were positive and significantly correlated in the most oligotrophic reservoir (Quéntar) and in the reservoir with the highest ratio of surface area to mixing water depth (Cubillas). Despite these correlations, WSOC atmospheric inputs represented less than 10% of the total DOC pool, suggesting that indirect effects of dust inputs on reservoir DOC may also promote these synchronous patterns observed in the reservoirs. Chromophoric components from dust inputs can significantly reduce the water transparency to the ultraviolet radiation (UVR). The depths where UVR at λ = 320 nm was reduced to ten percent of surface intensity (Z10%) decreased 27 cm in Béznar, 49 cm in Cubillas, and 69 cm in Quéntar due to the dust inputs. Therefore, the increasing dust export to the atmosphere may have consequences for the water transparency of aquatic ecosystems located under the influence of the global dust belt.

  2. Teknologi penyamakan kulit wet blue buaya

    Directory of Open Access Journals (Sweden)

    Bambang Oetojo

    1992-08-01

    Full Text Available For this study it was used 12 pieces of grain salted crocodile skin of 11 up to 14 inch width. All of the crocodile skin were process up to pickling with the same way. Furthermore pickled crocodile skins were process up to pickling with the same way. Furthermore pickled crocodile skins and was done twice. The wet blue output from the research was visual investigated for the coulor using staning scale method. For comparition it was used pickled crocodile skins. Statistical analysis pints out that there is unsignify difference (P<0.05 the influence of the used of basic chrome sulphate to the colour of wet blue crocodile skins. Practical meaning of the research is, for tanning of crocodile skins to the wet blue, it is used 1.5% basic chromium sulphate.

  3. Molecular Dynamics Simulations for Predicting Surface Wetting

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2014-06-01

    Full Text Available The investigation of wetting of a solid surface by a liquid provides important insights; the contact angle of a liquid droplet on a surface provides a quantitative measurement of this interaction and the degree of attraction or repulsion of that liquid type by the solid surface. Molecular dynamics (MD simulations are a useful way to examine the behavior of liquids on solid surfaces on a nanometer scale. Thus, we surveyed the state of this field, beginning with the fundamentals of wetting calculations to an examination of the different MD methodologies used. We highlighted some of the advantages and disadvantages of the simulations, and look to the future of computer modeling to understand wetting and other liquid-solid interaction phenomena.

  4. 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

  5. Insight into the wetting of a graphene-mica slit pore with a monolayer of water

    Science.gov (United States)

    Lin, Hu; Schilo, Andre; Kamoka, A. Rauf; Severin, Nikolai; Sokolov, Igor M.; Rabe, Jürgen P.

    2017-05-01

    Scanning force microscopy (SFM) and Raman spectroscopy allow the unraveling of charge doping and strain effects upon wetting and dewetting of a graphene-mica slit pore with water. SFM reveals a wetting monolayer of water, slightly thinner than a single layer of graphene. The Raman spectrum of the dry pore exhibits the D' peak of graphene, which practically disappears upon wetting, and recurs when the water layer dewets the pore. Based on the 2 D - and G -peak positions, the corresponding peak intensities, and the widths, we conclude that graphene on dry mica is charge-doped and variably strained. A monolayer of water in between graphene and mica removes the doping and reduces the strain. We attribute the D' peak to direct contact of the graphene with the ionic mica surface in dry conditions, and we conclude that a complete monolayer of water wetting the slit pore decouples the graphene from the mica substrate both mechanically and electronically.

  6. Reservoir Cathode for Electric Space Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a reservoir cathode to improve performance in both ion and Hall-effect thrusters. We propose to adapt our existing reservoir cathode technology to this...

  7. 49 CFR 236.792 - Reservoir, equalizing.

    Science.gov (United States)

    2010-10-01

    ... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of the equalizing piston chamber of the automatic brake valve, to provide uniform service reductions in brake pipe...

  8. Evaporation and wetted area of single droplets on waxy and hairy leaf surfaces.

    Science.gov (United States)

    Zhu, H; Yu, Y; Ozkan, H E; Derksen, R C; Krause, C R

    2008-01-01

    Understanding the evaporation of pesticide droplets and wetting of Leaf surfaces can increase foliar application efficiency and reduce pesticide use. Evaporation time and wetted area of single pesticide droplets on hairy and waxy geranium leaf surfaces were measured under the controlled conditions for five droplet sizes and three relative humidities. The sprays used to form droplets included water, a nonionic colloidal polymer drift retardant, an alkyl polyoxyethylene surfactant, and an insecticide. Adding the surfactant into spray mixtures greatly increased droplet wetted area on the surfaces while droplet evaporation time was greatly reduced. Adding the drift retardant into spray mixture slightly increased the droplet evaporation time and the wetted area. Also, droplets had Longer evaporation times on waxy leaves than on hairy leaves for all droplet diameters and all relative humidity conditions. Increasing relative humidity could increase the droplet evaporation time greatly but did not change the the wetted area. The droplet evaporation time and wetted area increased exponentially as the droplet size increased. Therefore, droplet size, surface characteristics of the target, relative humidity, and chemical composition of the spray mixtures (water alone, pesticide, additives) should be included as important factors that affect the efficacy and efficiency of pesticide applications.

  9. The Methane Hydrate Reservoir System

    Science.gov (United States)

    Flemings, P. B.; Liu, X.

    2007-12-01

    We use multi phase flow modeling and field examples (Hydrate Ridge, offshore Oregon and Blake Ridge, offshore North Carolina) to demonstrate that the methane hydrate reservoir system links traditional and non- traditional hydrocarbon system components: free gas flow is a fundamental control on this system. As in a traditional hydrocarbon reservoir, gas migrates into the hydrate reservoir as a separate phase (secondary migration) where it is trapped in a gas column beneath the base of the hydrate layer. With sufficient gas supply, buoyancy forces exceed either the capillary entry pressure of the cap rock or the fracture strength of the cap rock, and gas leaks into the hydrate stability zone, or cap rock. When gas enters the hydrate stability zone and forms hydrate, it becomes a very non traditional reservoir. Free gas forms hydrate, depletes water, and elevates salinity until pore water is too saline for further hydrate formation: salinity and hydrate concentration increase upwards from the base of the regional hydrate stability zone (RHSZ) to the seafloor and the base of the hydrate stability zone has significant topography. Gas chimneys couple the free gas zone to the seafloor through high salinity conduits that are maintained at the three-phase boundary by gas flow. As a result, significant amounts of gaseous methane can bypass the RHSZ, which implies a significantly smaller hydrate reservoir than previously envisioned. Hydrate within gas chimneys lie at the three-phase boundary and thus small increases in temperature or decreases in pressure can immediately transport methane into the ocean. This type of hydrate deposit may be the most economical for producing energy because it has very high methane concentrations (Sh > 70%) located near the seafloor, which lie on the three-phase boundary.

  10. The transformation of rivers’ temperature regime downstream of reservoirs

    Directory of Open Access Journals (Sweden)

    Kirvel Ivan

    2015-12-01

    Full Text Available The article is dedicated to the problem of the transformation of rivers’ temperature conditions influenced by artificial reservoirs. A quantitative estimation of average water temperatures over ten days, and maximum and average annual water temperatures of regulated rivers downstream of reservoirs was made on the basis of the data analysis of a complete period of instrumental observations of the Republican Hydrometeorological Centre of the Republic of Belarus. It is established that the character and the parameters of the transformation of temperature conditions of the regulated rivers along with morphometric features of the reservoirs are determined by the meteorological conditions of the year and the operating conditions of the water-engineering system. The length of the cooling period effect varies from 20 days downstream of small reservoirs to 50-70 days downstream of small and average size reservoirs. The warming effect is less significant by temperature, but lasts longer and is appreciable around 200-240 days in a year. An increase in the average annual water temperature up to 0.5°C and a decrease in maximum temperature down to 1.1°C are observed in the tail-water of average size storage pools. Small size storage pools demonstrate an annual increase in annual water temperature up to 0.3°C and a decrease in maximum temperature down to 0.3°C. Small size water pools show an increase both in annual water temperature up to 0.5°C and maximum water temperature up to 0.3°C. Typical changes in temperature conditions of rivers are observed for a distance of 130 kilometres below the dam of average size water pools, along 70 kilometres in small water pools and along 30 kilometres in tiny ones.

  11. Evaluation method for krypton-81m reservoir administration systems

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, A.G.; van Weeren, F.H.; de Goeij, J.J.; Wijnhoven, G.P.; Witsenboer, T.J.

    1989-05-01

    Large variations have been reported in counting rates during lung ventilation studies using different /sup 81m/Kr administration systems and among different patients. A method was set up to determine the activity utilization efficiency (AUE) using various administration systems. For that purpose a simple lung simulator was developed for combination with reservoir administration systems to be tested. It was found that under normal breathing conditions the AUE is 50% using a reservoir system and only 18% in the absence of a reservoir in the administration system. The measured results were confirmed by a mathematic model. The suggested simulator is suitable for use in hospitals and also enables an indirect check on the /sup 81/Rb//sup 81/mKr generator performance.

  12. A review on hydraulic fracturing of unconventional reservoir

    Directory of Open Access Journals (Sweden)

    Quanshu Li

    2015-03-01

    Full Text Available Hydraulic fracturing is widely accepted and applied to improve the gas recovery in unconventional reservoirs. Unconventional reservoirs to be addressed here are with very low permeability, complicated geological settings and in-situ stress field etc. All of these make the hydraulic fracturing process a challenging task. In order to effectively and economically recover gas from such reservoirs, the initiation and propagation of hydraulic fracturing in the heterogeneous fractured/porous media under such complicated conditions should be mastered. In this paper, some issues related to hydraulic fracturing have been reviewed, including the experimental study, field study and numerical simulation. Finally the existing problems that need to be solved on the subject of hydraulic fracturing have been proposed.

  13. Modeling Study of High Pressure and High Temperature Reservoir Fluids

    DEFF Research Database (Denmark)

    Varzandeh, Farhad

    S-characterization combinations and 260 reservoir fluids. PC-SAFT with the new general characterization method is shown to give the lowest AAD% and maximum deviation in calculation of saturation pressure, density and STO density, among all the tested characterization methods for PC-SAFT. Application of the new characterization...... be highly rewarding if successfully produced. This PhD project is part of the NextOil (New Extreme Oil and Gas in the Danish North Sea) project which is intended to reduce the uncertainties in HPHT field development. The main focus of this PhD is on accurate description of the reservoir fluid behavior under...... HPHT conditions to minimize the production risks from these types of reservoirs. In particular, the study has thoroughly evaluated several non-cubic Equations of State (EoSs) which are considered promising for HPHT fluid modeling, showing their advantages and short comings based on an extensive...

  14. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.

    2012-08-07

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  15. Reservoir characterization of the Snorre Field

    OpenAIRE

    Gjestvang, Jørgen

    2016-01-01

    Master's thesis in Petroleum engineering The fluvial sandstone in the Snorre field consists of braided to meander streams deposited in arid and in humid climate that show a clear differences in the sedimentology and reservoir properties, especially the silt content in large part of the reservoir which decrease the reservoir properties and water saturation. The heterogeneity of these fluvial formations combined with the faulting history makes this reservoir highly complex with many local an...

  16. Reservoir resistivity characterization incorporating flow dynamics

    KAUST Repository

    Arango, Santiago

    2016-04-07

    Systems and methods for reservoir resistivity characterization are provided, in various aspects, an integrated framework for the estimation of Archie\\'s parameters for a strongly heterogeneous reservoir utilizing the dynamics of the reservoir are provided. The framework can encompass a Bayesian estimation/inversion method for estimating the reservoir parameters, integrating production and time lapse formation conductivity data to achieve a better understanding of the subsurface rock conductivity properties and hence improve water saturation imaging.

  17. Stochastic optimal operation of reservoirs based on copula functions

    Science.gov (United States)

    Lei, Xiao-hui; Tan, Qiao-feng; Wang, Xu; Wang, Hao; Wen, Xin; Wang, Chao; Zhang, Jing-wen

    2018-02-01

    Stochastic dynamic programming (SDP) has been widely used to derive operating policies for reservoirs considering streamflow uncertainties. In SDP, there is a need to calculate the transition probability matrix more accurately and efficiently in order to improve the economic benefit of reservoir operation. In this study, we proposed a stochastic optimization model for hydropower generation reservoirs, in which 1) the transition probability matrix was calculated based on copula functions; and 2) the value function of the last period was calculated by stepwise iteration. Firstly, the marginal distribution of stochastic inflow in each period was built and the joint distributions of adjacent periods were obtained using the three members of the Archimedean copulas, based on which the conditional probability formula was derived. Then, the value in the last period was calculated by a simple recursive equation with the proposed stepwise iteration method and the value function was fitted with a linear regression model. These improvements were incorporated into the classic SDP and applied to the case study in Ertan reservoir, China. The results show that the transition probability matrix can be more easily and accurately obtained by the proposed copula function based method than conventional methods based on the observed or synthetic streamflow series, and the reservoir operation benefit can also be increased.

  18. Direct hydrocarbon exploration and gas reservoir development technology

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Young Hoon; Oh, Jae Ho; Jeong, Tae Jin [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)] [and others

    1995-12-01

    In order to enhance the capability of petroleum exploration and development techniques, three year project (1994 - 1997) was initiated on the research of direct hydrocarbon exploration and gas reservoir development. This project consists of four sub-projects. (1) Oil(Gas) - source rock correlation technique: The overview of bio-marker parameters which are applicable to hydrocarbon exploration has been illustrated. Experimental analysis of saturated hydrocarbon and bio-markers of the Pohang E and F core samples has been carried out. (2) Study on surface geochemistry and microbiology for hydrocarbon exploration: the test results of the experimental device for extraction of dissolved gases from water show that the device can be utilized for the gas geochemistry of water. (3) Development of gas and gas condensate reservoirs: There are two types of reservoir characterization. For the reservoir formation characterization, calculation of conditional simulation was compared with that of unconditional simulation. In the reservoir fluid characterization, phase behavior calculations revealed that the component grouping is more important than the increase of number of components. (4) Numerical modeling of seismic wave propagation and full waveform inversion: Three individual sections are presented. The first one is devoted to the inversion theory in general sense. The second and the third sections deal with the frequency domain pseudo waveform inversion of seismic reflection data and refraction data respectively. (author). 180 refs., 91 figs., 60 tabs.

  19. Use of Operational Climate Forecasts in Reservoir Management and Operation

    Science.gov (United States)

    Arumugam, S.; Lall, U.

    2005-12-01

    Seasonal streamflow forecasts contingent on climate information are essential for short-term planning and for setting up contingency measures during extreme years. Similarly, monthly updates of streamflow forecasts are useful in quantifying surplus and shortfall in addressing the change in streamflow potential during the season. In this study, an operational streamflow forecasts for managing the Angat Reservoir System, Philippines, is developed using the precipitation forecasts from Atmospheric General Circulation Models (AGCM) that are forced by persisted Sea Surface Temperature (SST) conditions. The methodology employs principal components regression (PCR) to downscale the AGCM predicted precipitation fields to monthly streamflow forecasts. By performing retrospective analyses that combines streamflow forecasts with a dynamic water allocation model, we show that use of updated climate forecasts in reservoir operation results in increased reservoir system yields in comparison to using the seasonal streamflow forecasts alone. Revising the reservoir operation strategy based on updated streamflow forecasts is particularly critical in hydropower systems, since the increased yields from reduced spillage could be effectively utilized for power generation during above-normal inflow years. Further, analyzing the system performance under different scenarios of storage and demand, we show that the utility of climate information based reservoir inflow forecasts is more pronounced for systems with low storage to demand ratio.

  20. Inflow forecasting using Artificial Neural Networks for reservoir operation

    Directory of Open Access Journals (Sweden)

    C. Chiamsathit

    2016-05-01

    Full Text Available In this study, multi-layer perceptron (MLP artificial neural networks have been applied to forecast one-month-ahead inflow for the Ubonratana reservoir, Thailand. To assess how well the forecast inflows have performed in the operation of the reservoir, simulations were carried out guided by the systems rule curves. As basis of comparison, four inflow situations were considered: (1 inflow known and assumed to be the historic (Type A; (2 inflow known and assumed to be the forecast (Type F; (3 inflow known and assumed to be the historic mean for month (Type M; and (4 inflow is unknown with release decision only conditioned on the starting reservoir storage (Type N. Reservoir performance was summarised in terms of reliability, resilience, vulnerability and sustainability. It was found that Type F inflow situation produced the best performance while Type N was the worst performing. This clearly demonstrates the importance of good inflow information for effective reservoir operation.

  1. Calculating Soil Wetness, Evapotranspiration and Carbon Cycle Processes Over Large Grid Areas Using a New Scaling Technique

    Science.gov (United States)

    Sellers, Piers

    2012-01-01

    Soil wetness typically shows great spatial variability over the length scales of general circulation model (GCM) grid areas (approx 100 km ), and the functions relating evapotranspiration and photosynthetic rate to local-scale (approx 1 m) soil wetness are highly non-linear. Soil respiration is also highly dependent on very small-scale variations in soil wetness. We therefore expect significant inaccuracies whenever we insert a single grid area-average soil wetness value into a function to calculate any of these rates for the grid area. For the particular case of evapotranspiration., this method - use of a grid-averaged soil wetness value - can also provoke severe oscillations in the evapotranspiration rate and soil wetness under some conditions. A method is presented whereby the probability distribution timction(pdf) for soil wetness within a grid area is represented by binning. and numerical integration of the binned pdf is performed to provide a spatially-integrated wetness stress term for the whole grid area, which then permits calculation of grid area fluxes in a single operation. The method is very accurate when 10 or more bins are used, can deal realistically with spatially variable precipitation, conserves moisture exactly and allows for precise modification of the soil wetness pdf after every time step. The method could also be applied to other ecological problems where small-scale processes must be area-integrated, or upscaled, to estimate fluxes over large areas, for example in treatments of the terrestrial carbon budget or trace gas generation.

  2. Tenth workshop on geothermal reservoir engineering: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-22

    The workshop contains presentations in the following areas: (1) reservoir engineering research; (2) field development; (3) vapor-dominated systems; (4) the Geysers thermal area; (5) well test analysis; (6) production engineering; (7) reservoir evaluation; (8) geochemistry and injection; (9) numerical simulation; and (10) reservoir physics. (ACR)

  3. 32 CFR 644.4 - Reservoir Projects.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Reservoir Projects. 644.4 Section 644.4 National... HANDBOOK Project Planning Civil Works § 644.4 Reservoir Projects. (a) Joint land acquisition policy for reservoir projects. The joint policies of the Department of the Interior and the Department of the Army...

  4. Heat treated twin wire arc spray AISI 420 coatings under dry and wet abrasive wear

    Science.gov (United States)

    Rodriguez, E.; González, M. A.; Monjardín, H. R.; Jimenez, O.; Flores, M.; Ibarra, J.

    2017-11-01

    The influence of applying two different heat treatments such as: deep cryogenic and tempering on dry/wet abrasive wear resistance of twin wire arc spray martensitic AISI 420 coatings was evaluated by using a modified rubber wheel type test apparatus. A load dependency was observed on the abrasive wear rate behavior of both; dry and wet tests. Three body (rolling) and two body (sliding) wear mechanisms were identified in dry conditions, prevailing rolling at lower and higher loads. However, at higher loads, more presence of grooving and pits formation was observed. Coatings tempered at 205 °C/1 h displayed better wear resistance than cryogenic treated ones. A change in wear mechanism between dry and wet conditions was observed; two body wear mechanism predominated respect to three body. In both; dry and wet conditions the microstructure (several inter-splat oxides) as well as strain and residual stress promotes brittle material removal which was more evident in cryogenic and as-sprayed samples during dry test and at higher loads in wet conditions.

  5. Monitoring gas reservoirs by seismic interferometry

    Science.gov (United States)

    Grigoli, Francesco; Cesca, Simone; Sens-Schoenfelder, Christoph; Priolo, Enrico

    2014-05-01

    Ambient seismic noise can be used to image spatial anomalies in the subsurface, without the need of recordings from seismic sources, such as earthquakes or explosions. Furthermore, the temporal variation of ambient seismic noise's can be used to infer temporal changes of the seismic velocities in the investigated medium. Such temporal variations can reflect changes of several physical properties/conditions in the medium. For example, they may be consequence of stress changes, variation of hydrogeological parameters, pore pressure and saturation changes due to fluid injection or extraction. Passive image interferometry allows to continuously monitor small temporal changes of seismic velocities in the subsurface, making it a suitable tool to monitor time-variant systems such as oil and gas reservoirs or volcanic environments. The technique does not require recordings from seismic sources in the classical sense, but is based on the processing of noise records. Moreover, it requires only data from one or two seismic stations, their locations constraining the sampled target area. Here we apply passive image interferometry to monitor a gas storage reservoir in northern Italy. The Collalto field (Northern Italy) is a depleted gas reservoir located at 1500 m depth, now used as a gas storage facility. The reservoir experience a significant temporal variation in the amount of stored gas: the injection phases mainly occur in the summer, while the extraction take place mostly in winter. In order to monitor induced seismicity related to gas storage operations, a seismic network (the Collalto Seismic Network) has been deployed in 2011. The Collalto Seismic Network is composed by 10 broadband stations, deployed within an area of about 20 km x 20 km, and provides high-quality continuous data since January 1st, 2012. In this work we present preliminary results from ambient noise interferometry using a two-months sample of continuous seismic data, i.e. from October 1st, 2012, to the

  6. Increasing Waterflooding Reservoirs in the Wilmington Oil Field through Improved Reservoir Characterization and Reservoir Management, Class III

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, Roy; Clarke, Don; Walker, Scott; Phillips, Chris; Nguyen, John; Moos, Dan; Tagbor, Kwasi

    2001-08-07

    This project was intended to increase recoverable waterflood reserves in slope and basin reservoirs through improved reservoir characterization and reservoir management. The particular application of this project is in portions of Fault Blocks IV and V of the Wilmington Oil Field, in Long Beach, California, but the approach is widely applicable in slope and basin reservoirs, transferring technology so that it can be applied in other sections of the Wilmington field and by operators in other slope and basin reservoirs is a primary component of the project.

  7. Real-time reservoir geological model updating using the hybrid EnKF and geostatistical technique

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.; Chen, S.; Yang, D. [Regina Univ., SK (Canada). Petroleum Technology Research Centre

    2008-07-01

    Reservoir simulation plays an important role in modern reservoir management. Multiple geological models are needed in order to analyze the uncertainty of a given reservoir development scenario. Ideally, dynamic data should be incorporated into a reservoir geological model. This can be done by using history matching and tuning the model to match the past performance of reservoir history. This study proposed an assisted history matching technique to accelerate and improve the matching process. The Ensemble Kalman Filter (EnKF) technique, which is an efficient assisted history matching method, was integrated with a conditional geostatistical simulation technique to dynamically update reservoir geological models. The updated models were constrained to dynamic data, such as reservoir pressure and fluid saturations, and approaches geologically realistic at each time step by using the EnKF technique. The new technique was successfully applied in a heterogeneous synthetic reservoir. The uncertainty of the reservoir characterization was significantly reduced. More accurate forecasts were obtain