WorldWideScience
1

The estimation of oil water displacement functions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: English Abstract in english We introduce an algorithm to solve an inverse problem for a non-linear hyperbolic partial differential equation. It can be used to estimate the oil-fractional flow function from the Buckley-Leverett equation. The direct model is non-linear: the sought for parameter is a function of the solution of t [...] he equation. Traditionally, the estimation of functions requires the election of a fitting parametric model. The algorithm that we develop does not require a predetermined parameter model. Therefore, the estimation problem is carried out over a set of parameters which are functions. The parameter is inferred from measurements of saturation at different spatial points as a function of time. The estimation procedure is carried out linearizing the solution of the direct model with respect to the parameter and then computing the least-squares solution in functional spaces. The sensitivity equations are derived. We test the algorithm with several numerical experiments.

G. B., Savioli; E. M., Fernández-Berdaguer.

2007-09-01

2

Above Water: Buoyancy & Displacement  

Science.gov (United States)

In an investigation called "Shape It!" learners craft tiny boats out of clay, set them afloat on water and then add weight loads to them, in order to explore: how objects stay afloat in water; what the relationship is among surface tension, buoyancy, density and displacement; and how shape, size, and type of material affect an object's ability to remain buoyant. The introductory text discusses how heavy steel ships can float on bodies of water like rivers, bays and oceans.

New Jersey

2006-01-01

3

Surface-functionalized nanoparticle permeation triggers lipid displacement and water and ion leakage.  

Science.gov (United States)

Functionalized nanoparticles (NPs) are considered suitable carriers for targeted drug delivery systems. However, the ion and water leakage induced by permeation of these nanoparticles is a challenge in these drug delivery methods because of cytotoxic effects of some ions. In this study, we have carried out a series of coarse-grained molecular dynamics simulations to investigate the effect of length of ligands on permeation of a nanoparticle across a protein-free phospholipid bilayer membrane. Water and ion penetration as well as incidence of lipid flip-flop events and loss of lipid molecules from the membrane are explored in this study while varying the nanoparticle size, length of ligand, ion concentration gradient, pressure differential across the membrane, and nanoparticle permeation velocity. Some results from our studies include (1) the number of water molecules in the interior of the membrane during ligand-coated nanoparticle permeation increases with nanoparticle size, ligand length, pressure differential, and permeation velocity but is not sensitive to the ion concentration gradient; (2) some lipid molecules leave the membrane by being entangled with ligands of the NP instead of completing the flip-flop that permits them to rejoin the membrane, thereby leading to fewer flip-flop events; and (3) the formation of water columns or water "fingers" provides a mechanism of ion transport across lipid bilayer membranes, but such ion penetration events are less likely for sodium ions than chloride ions and less likely for nanoparticles with longer-ligands. PMID:25549137

Oroskar, Priyanka A; Jameson, Cynthia J; Murad, Sohail

2015-01-27

4

Monitoring Changes in Soil Water Content Using Subsurface Displacement  

Science.gov (United States)

Closing the water balance is important in many research and water resource applications, but it can be difficult to accomplish due to a variety of factors. A new technique that measures vertical displacement of soil in order to estimate the change in mass of water stored in overlying material is being developed. The measurement technique uses an extensometer that functions as a lysimeter, and we refer to the technique as Displacement Extensometry for Lysimetric Terrain Analysis (DELTA). DELTA extensometers are 2-m-long devices deployed by creating a friction fit with intact soil below a cased borehole. The instrument measures small displacements (better than 10 nm resolution) in response to changes of mass in the overlying soil, or other factors. The instrument averages over a region that scales with the depth of installation (the radius of influence is approximately 2x the depth). The spatial averaging of this instrument extends over regions representative of agricultural fields, hydrologic model grid blocks, and small watersheds. Five DELTA extensometers have been deployed at a field site near Clemson, SC at depths of 3, 6, and 9 m within saprolite derived from biotite gneiss. Barometric pressure, precipitation, and soil moisture are being measured along with displacement. Signals from the co-located extensometers are remarkably similar, demonstrating reproducibility of the technique. Rainfall causes soil compression, and at 6 m depth there is approximately 200 nm of compression per 1 mm of rainfall. There is gradual expansion, which ranges from 0.15 to 1.75 ?m/day, following rainfall. The gradual unloading of the soil is interpreted as water loss due to evapotranspiration. Superimposed on the signal are diurnal fluctuations of 0.5 to 1 ?m, which correlate to changes in barometric pressure. Four DELTA extensometers were recently deployed in hard, clayey sediments at two field locations south of Amarillo, TX. The instruments will compliment current research on groundwater recharge in playas. Two other extensometers were deployed in loess at a field site near Holdredge, NE, where they will be used to help characterize water cycling beneath irrigated agriculture. Calibration data has been obtained and the instruments appear to be functioning properly. The preliminary data suggest that the DELTA technique should be applicable in a variety of soil types.

Thrash, C. J.; Miller, S.; Murdoch, L. C.; Germanovich, L. N.; Gates, J. B.; Volkmer, A.; Weinburg, A.

2013-12-01

5

Liquid CO2 Displacement of Water in a Dual-Permeability Pore Network Micromodel  

Energy Technology Data Exchange (ETDEWEB)

Permeability contrasts exist in multilayer geological formations under consideration for carbon sequestration. To improve our understanding of heterogeneous pore-scale displacements, liquid CO2 (LCO2) - water displacement was evaluated in a pore network micromodel with two distinct permeability zones. Due to the low viscosity ratio (logM = -1.1), unstable displacement occurred at all injection rates over two orders of magnitude. LCO2 displaced water only in the high permeability zone at low injection rates with the mechanism shifting from capillary fingering to viscous fingering with increasing flow rate. At high injection rates, LCO2 displaced water in the low permeability zone with capillary fingering as the dominant mechanism. LCO2 saturation (SLCO2) as a function of injection rate was quantified using fluorescent microscopy. In all experiments, more than 50% of LCO2 resided in the active flowpaths, and this fraction increased as displacement transitioned from capillary to viscous fingering. A continuum-scale two-phase flow model with independently determined fluid and hydraulic parameters was used to predict SLCO2 in the dual-permeability field. Agreement with the micromodel experiments was obtained for low injection rates. However, the numerical model does not account for the unstable viscous fingering processes observed experimentally at higher rates and hence overestimated SLCO2.

Zhang, Changyong; Oostrom, Martinus; Grate, Jay W.; Wietsma, Thomas W.; Warner, Marvin G.

2011-09-01

6

Liquid CO2 displacement of water in a dual-permeability pore network micromodel.  

Science.gov (United States)

Permeability contrasts exist in multilayer geological formations under consideration for carbon sequestration. To improve our understanding of heterogeneous pore-scale displacements, liquid CO(2) (LCO(2))-water displacement was evaluated in a pore network micromodel with two distinct permeability zones. Due to the low viscosity ratio (logM = -1.1), unstable displacement occurred at all injection rates over 2 orders of magnitude. LCO(2) displaced water only in the high permeability zone at low injection rates with the mechanism shifting from capillary fingering to viscous fingering with increasing flow rate. At high injection rates, LCO(2) displaced water in the low permeability zone with capillary fingering as the dominant mechanism. LCO(2) saturation (S(LCO2)) as a function of injection rate was quantified using fluorescent microscopy. In all experiments, more than 50% of LCO(2) resided in the active flowpaths, and this fraction increased as displacement transitioned from capillary to viscous fingering. A continuum-scale two-phase flow model with independently determined fluid and hydraulic parameters was used to predict S(LCO2) in the dual-permeability field. Agreement with the micromodel experiments was obtained for low injection rates. However, the numerical model does not account for the unstable viscous fingering processes observed experimentally at higher rates and hence overestimated S(LCO2). PMID:21774502

Zhang, Changyong; Oostrom, Mart; Grate, Jay W; Wietsma, Thomas W; Warner, Marvin G

2011-09-01

7

Displaced Water Volume, Potential Energy of Initial Elevation, and Tsunami Intensity: Analysis of Recent Tsunami Events  

Science.gov (United States)

We consider recent ocean-bottom earthquakes for which detailed slip distribution data are available. Using these data and the Okada formulae, we calculate the vector fields of co-seismic bottom deformations, which allow us to determine the displaced water volume and the potential energy of initial elevation of the tsunami source. It is shown that, in the majority of cases, the horizontal components of bottom deformation provide an additional contribution to the displaced water volume and virtually never diminish the contribution of the vertical component. The absolute value of the relative contribution of the horizontal components of bottom deformation to the displaced volume varies from 0.07 to 55 %, on average amounting to 14 %. The displaced volume and the energy of initial elevation (tsunami energy) are examined as functions of the moment magnitude, and the relevant regressions (least-squares fits) are derived. The obtained relationships exhibit good correspondence with the theoretical upper limits that had been obtained under the assumption of uniform slip distribution along a rectangular fault. Tsunami energy calculated on the basis of finite fault model data is compared with the earthquake energy determined from the energy-magnitude relationship by Kanamori. It is shown that tsunami takes from 0.001 to 0.34 % of the earthquake energy, and on average 0.04 %. Finally, we analyze the Soloviev-Imamura tsunami intensity as a function of the following three quantities: (1) the moment magnitude, (2) the decimal logarithm of the absolute value of displaced volume, and (3) the decimal logarithm of the potential energy of initial elevation. The first dependence exhibits rather poor correlation, whereas the second and third dependences demonstrate noticeably higher correlation coefficients. This gives us grounds to suggest considering the displaced volume and the energy of initial elevation as measures of the tsunamigenic potential of an earthquake.

Nosov, Mikhail A.; Bolshakova, Anna V.; Kolesov, Sergey V.

2014-12-01

8

Landslide velocity prediction using a rainfall to displacements transfer function. La Barmasse case study (Valais, Switzerland).  

Science.gov (United States)

We present a model for ground displacements prediction using a transfer function. Model was mainly tested at the Barmasse rockslide (Valais, Switzerland) which is an active structurally-controlled instability formed by intensively deformed and metamorphosed mica schists. The kinematics of the slide, which currently threatens roads and inhabitants of the Bal de Bagnes Valley, is characterized by a continuous displacement with variable rates of displacements. Indeed, the velocity is strongly affected by external forces: a sharp increase in landslide velocity is observed with a short delay after every snow melting period and after each rainfall pulse. The instability is currently monitored by different remote sensing and in situ techniques (Terrestrial LiDAR, GB Radar and extensometers). In order to predict ground displacements, we developed a new model composed by two different parts: (a) calculation of the Effective Rainfall (Peff) and (b) modelling of the landslide velocity. First of all, Peff was obtained using Thornthwaite (1946) method, which estimates the water that infiltrates into the terrain as a function of the total precipitation, Real Evapo-Transpiration (ETR) and water recharge. Afterwards, the rates of displacement were modelled through a stochastic transfer function which links the Peff (input) with daily displacements (output). Model computes the displacement rates at each time lapse (e.g. one day) as a convolution of the above mentioned transfer function times daily effective rainfall during a certain time lapse (50 days in our case). The transfer function has two components: first component account for the sudden increase of landslide velocities after each rainfall pulse and second component account for the progressive decay. The variables of these functions were optimized in Matlab in order to minimize the error between the real and the modelled velocities. The model performance was assessed for two different response functions (following either exponential or power laws) through errors in timing, duration, magnitude and Root Mean Square of the differences between the model and the real measurements. Furthermore, predictive capabilities of the model were tested by using training and testing sets, showing good resemblance between modelled and real displacements. Nevertheless, we observed a non-stationary response of the transfer function along the different years of the period of study, which should be analysed more in detail. At a wider perspective, we tested the applicability of our model to other pilot study areas using both digitised datasets available in literacy and RAW datasets provided by other research groups. This analysis proved generalisation of our method to different environmental conditions, materials permeability, failure mechanisms, degree of damage, etc. Due to the ease of data input variables (rainfall and temperature), relative simplicity of the model, high performance of the results and generalisation of the model to other study areas, it is our belief that transfer function models will be a common tool for landslide velocity forecasting in the near future.

Abellán, Antonio; Michoud, Clément; Jaboyedoff, Michel; Baillifard, François; Demierre, Jonathan; Carrea, Dario

2013-04-01

9

Lattice Boltzmann simulations of supercritical CO2-water drainage displacement in porous media: CO2 saturation and displacement mechanism.  

Science.gov (United States)

CO2 geosequestration in deep aquifers requires the displacement of water (wetting phase) from the porous media by supercritical CO2 (nonwetting phase). However, the interfacial instabilities, such as viscous and capillary fingerings, develop during the drainage displacement. Moreover, the burstlike Haines jump often occurs under conditions of low capillary number. To study these interfacial instabilities, we performed lattice Boltzmann simulations of CO2-water drainage displacement in a 3D synthetic granular rock model at a fixed viscosity ratio and at various capillary numbers. The capillary numbers are varied by changing injection pressure, which induces changes in flow velocity. It was observed that the viscous fingering was dominant at high injection pressures, whereas the crossover of viscous and capillary fingerings was observed, accompanied by Haines jumps, at low injection pressures. The Haines jumps flowing forward caused a significant drop of CO2 saturation, whereas Haines jumps flowing backward caused an increase of CO2 saturation (per injection depth). We demonstrated that the pore-scale Haines jumps remarkably influenced the flow path and therefore equilibrium CO2 saturation in crossover domain, which is in turn related to the storage efficiency in the field-scale geosequestration. The results can improve our understandings of the storage efficiency by the effects of pore-scale displacement phenomena. PMID:25427299

Yamabe, Hirotatsu; Tsuji, Takeshi; Liang, Yunfeng; Matsuoka, Toshifumi

2015-01-01

10

Displacement as a predictor of functional impairment in tsunami-exposed children.  

Science.gov (United States)

Thirty months after the Indian Ocean tsunami of 26 December 2004, thousands of families in Aceh Province, Indonesia, remained in temporary barracks while sanitation conditions and non-governmental organisation support deteriorated. This study sought to determine the factors associated with functional impairment in a sample of 138 displaced and non-displaced Acehnese children. Using multivariate linear regression models, it was found that displacement distance was a consistent predictor of impairment using the Brief Impairment Scale. Exposure to tsunami-related trauma markers was not significantly linked with impairment in the model. Paternal employment was a consistent protective factor for child functioning. These findings suggest that post-disaster displacement and the subsequent familial economic disruption are significant predictors of impaired functioning in children's daily activities. Post-disaster interventions should consider the disruption of familiar environments for families and children when relocating vulnerable populations to avoid deleterious impacts on children's functioning. PMID:25231556

Lee, Christopher; Du, Ye Beverly; Christina, Desy; Palfrey, Judith; O'Rourke, Edward; Belfer, Myron

2015-01-01

11

New method to determine initial surface water displacement at tsunami source  

Science.gov (United States)

Friday, March 11, 2011 at 05:46:23 UTC, Japan was struck by an 8.9-magnitude earthquake near its Northeastern coast. This is one of the largest earthquakes that Japan has ever experienced. Tsunami waves swept away houses and cars and caused massive human losses. To predict tsunami wave parameters better and faster, we propose to improve data inversion scheme and achieve the performance gain of data processing. One of the reasons of inaccurate predictions of tsunami parameters is that very little information is available about the initial disturbance of the sea bed at tsunami source. In this paper, we suggest a new way of improving the quality of tsunami source parameters prediction. Modern computational technologies can accurately calculate tsunami wave propagation over the deep ocean provided that the initial displacement (perturbation of the sea bed at tsunami source) is known [4]. Direct geophysical measurements provide the location of an earthquake hypocenter and its magnitude (the released energy evaluation). Among the methods of determination of initial displacement the following ones should be considered. Calculation through the known fault structure and available seismic information. This method is widely used and provides useful information. However, even if the exact knowledge about rock blocks shifts is given, recalculation in terms of sea bed displacement is needed. This results in a certain number of errors. GPS data analysis. This method was developed after the December 2004 event in the Indian Ocean. A good correlation between dry land based GPS sensors and tsunami wave parameters was observed in the particular case of the West coast of Sumatra, Indonesia. This approach is very unique and can hardly been used in other geo locations. Satellite image analysis. The resolution of modern satellite images has dramatically improved. In the future, correct data of sea surface displacement will probably be available in real time, right after a tsunamigenic earthquake. However, today it is not yet possible. Ground-based sea radars. This is an effective tool for direct measurement of tsunami wave. At the same time, the wave is measured at a rather narrow area in front of the radar and does not include information about neighboring parts of the wave. Direct measurement of tsunami wave at deep water [2]. Today, this technology is certainly among the most useful and promising. The DART II® system consists of a seafloor bottom pressure recording (BPR) system, capable of detecting tsunamis as small as 1 cm, and a moored surface buoy for real-time communications. We focus our research on improving the later method, direct measurement of tsunami wave at deep water. We suggest the new way to analyze DART data, modifying the methodology originally proposed by V. Titov. Smaller system of unit sources [3] should be considered to approximate all typical shapes of initial disturbance by several suitable basis functions. To successfully implement it, performance of data analysis should be dramatically improved. This could be done by using a signal orthogonalization procedure for considered system of unit sources and calculation of Fourier coefficients of the measured time series with respect to orthogonal basis. The approach suggested was used as a part of computerized workstation for tsunami hazard monitoring [5-6]. National Oceanic and Atmospheric Administration Center for Tsunami Research. URL: http://nctr.pmel.noaa.gov/honshu20110311/ National Data Buoy Center. URL: http://www.ndbc.noaa.gov/dart.shtml National Oceanic and Atmospheric Administration Center for Tsunami Research. URL: http://sift.pmel.noaa.gov/thredds/dodsC/uncompressed/ National Oceanic and Atmospheric Administration Center for Tsunami Research. URL: http://nctr.pmel.noaa.gov/model.html Alexey Romanenko, Mikhail Lavrentiev-jr, Vasily Titov, "Modern Architecture for Tsunami Hazard Mitigation" // Asia Oceania Geosciences Society (AOGS-2012), ISBN 978-981-07-2049-0 Mikhail Lavrentiev-jr, Andrey Marchuk, Alexey Romanenko, Konstantin Simonov, and Vasiliy T

Lavrentyev, Mikhail; Romanenko, Alexey; Tatarintsev, Pavel

2013-04-01

12

Experimental study of displacement of viscous oil in pipes by water  

OpenAIRE

This study is specifically concerned with the understanding of real restart procedure that is very crucial for prediction of oil-water columns displacement after un-expected shut down at water-viscous crude oil transportation. This issue gets more important for subsea pipeline which is generally located in ups and downs topology and in average cold medium. At subsea pipelines the risk of formation of oil-water columns is high and in addition the viscosity of crude oil gets higher due to heat ...

Kazemihatami, Milad

2013-01-01

13

Displacement field analysis based on the combination digital speckle correlation method with radial basis function interpolation.  

Science.gov (United States)

The digital speckle correlation method (DSCM) has been widely used to resolve displacement and deformation gradient fields. The computational time and the computational accuracy are still two challenging problems faced in this area. In this paper, we introduce the radial basis function (RBF) interpolation method to DSCM and propose a method for displacement field analysis based on the combination of DSCM with RBF interpolation. We test the proposed method on two computer-simulated and two experimentally obtained deformation measurements and compare it with the widely used Newton-Raphson iteration (NR method). The experimental results demonstrate that our method performs better than the NR method in terms of both quantitative evaluation and visual quality. In addition, the total computational time of our method is considerably shorter than that of the NR method. Our method is particularly suitable for displacement field analysis of large regions. PMID:20733625

Tang, Chen; Wang, Linlin; Yan, Si; Wu, Jian; Cheng, Liyan; Li, Cancan

2010-08-20

14

Towards a better understanding of soluble adsorbed water displacing ionic additives  

OpenAIRE

Paper presented at the 25th Annual Southern African Transport Conference 10 - 13 July 2006 "2010: Will transport infrastructure and systems be ready?", CSIR International Convention Centre, Pretoria, South Africa. ABSTRACT: The use of SAWDIA (Soluble Adsorbed Water Displacing Ionic Additives) has not been as extensive in South Africa as the products really merit. These liquid stabilizers have been on the market in South Africa for over 30 years but even today many road engineers are not in fa...

Savage, P. F.

2008-01-01

15

Resolution Effects on the Mean Square Displacement as Obtained by the Self-Distribution-Function Procedure  

International Nuclear Information System (INIS)

In the present contribution, a procedure for molecular motion characterization based on the evaluation of the Mean Square Displacement (MSD), through the Self-Distribution Function (SDF), is presented. It is shown how MSD, which represents an important observable for the characterization of dynamical properties, can be decomposed into different partial contributions associated to system dynamical processes within a specific spatial scale. It is also shown how the SDF procedure allows us to evaluate both total MSD and partial MSDs through total and partial SDFs. As a result, total MSD is the weighed sum of partial MSDs in which the weights are obtained by the fitting procedure of measured Elastic Incoherent Neutron Scattering (EINS) intensity. We apply SDF procedure to data collected,by IN13, IN10 and IN4 spectrometers (Institute Laue Langevin), on aqueous mixtures of two homologous disaccharides (sucrose and trehalose) and on dry and hydrated (H2O and D2O) lysozyme with and without disaccharides. It emerges that the hydrogen bond imposed network of the water-trehalose mixture appears to be stronger with respect to that of the water-sucrose mixture. This result can justify the higher bioprotectant effectiveness of trehalose. Furthermore, it emerges that partial MSDs of sucrose and trehalose are equivalent in the low Q domain (0÷1.7) ??1 whereas they are different in the high Q domain (1.7÷4) ??1. This suggests that up>?1. This suggests that the higher structure sensitivity of sucrose should be related to the small spatial observation windows. Moreover, the role of the instrumental resolution in EINS is considered. The nature of the dynamical transition is highlighted and it is shown that it occurs when the system relaxation time becomes shorter than the instrumental energy time. Finally, the bioprotectants effect on protein dynamics and the amplitude of vibrations in lysozyme are presented.

16

A computational chemical study of penetration and displacement of water films near mineral surfaces  

Directory of Open Access Journals (Sweden)

Full Text Available A series of molecular dynamics simulations have been performed on organic–water mixtures near mineral surfaces. These simulations show that, in contrast to apolar compounds, small polar organic compounds such as phenols can penetrate through thin water films to adsorb on these mineral surfaces. Furthermore, additional simulations involving demixing of an organic–water mixture near a surfactant-covered mineral surface demonstrate that even low concentrations of adsorbed polar compounds can induce major changes in mineral surface wettability, allowing sorption of apolar molecules. This strongly supports a two-stage adsorption mechanism for organic solutes, involving initial migration of small polar organic molecules to the mineral surface followed by water film displacement due to co-adsorption of the more apolar organic compounds, thus converting an initial water-wet mineral system to an organic-covered surface. This has profound implications for studies of petroleum reservoir diagenesis and wettability changes.

Larter Steve R

2001-08-01

17

STRESS, STRAIN AND DISPLACEMENT OF A FUNCTIONALLY GRADED THICK SPHERICAL VESSEL  

OpenAIRE

This work aims at the determination of the displacements, strains, and stresses from the general analytical solution of a functionally graded thick spherical vessel with the consideration that theproperties of the material i.e. modulus of elasticity, thermal expansion coefficient and thermal conductivity, vary with the power-law of radius and Poisson’s ratio remains constant. With the third kind thermal boundary conditions, with steady-state unidirectional radial heat conduction and general...

P NAYAK,; S C MONDAL,; Nandi, A.

2011-01-01

18

Simple model of bouncing ball dynamics: displacement of the table assumed as quadratic function of time  

OpenAIRE

Nonlinear dynamics of a bouncing ball moving in gravitational field and colliding with a moving limiter is considered. Displacement of the limiter is a quadratic function of time. Several dynamical modes, such as fixed points, 2 - cycles and chaotic bands are studied analytically and numerically. It is shown that chaotic bands appear due to homoclinic structures created from unstable 2 - cycles in a corner-type bifurcation.

Okninski, Andrzej; Radziszewski, Boguslaw

2010-01-01

19

Evaluation of upper-extremity function following surgical treatment of displaced proximal humerus fractures in children.  

Science.gov (United States)

This study aims to assess the functional outcome of children treated with elastic stable intramedullary nailing (ESIN) for displaced proximal humerus fractures using the short version of the disabilities of the arm, shoulder, and hand outcome questionnaire (Quick DASH). Fifty-eight consecutive children with displaced proximal humerus fractures were treated with ESIN. Fifty-two children (89.7%) were available for follow-up and responded to the questionnaire after hardware removal. Average age at time of injury was 11.1 ± 2.8 years (range, 4-15.9). Among the 52 patients available for evaluation, 37 had a Quick DASH score of 0 (71.1%), seven a score of 2.3 (13.5%), four a score of 4.5 (7.7%), and four a score of 6.5 (7.7%). Shoulder and elbow ranges of motion were comparable with the noninjured side. No skin irritation or local infections were observed. There was no radiographic evidence of delayed union, refracture, hardware migration, or secondary displacement. Mean follow-up was 18.3 ± 8.3 months (range, 6-39.5). Our study reports good functional outcomes in children with closed isolated fractures, both physeal and metaphyseal, of the proximal humerus treated with ESIN. The use of a standardized rating scale is recommended to homogeneously compare functional outcome and may facilitate the comparison of clinical outcome in different patient populations. PMID:24172646

Canavese, Federico; Athlani, Lionel; Marengo, Lorenza; Rousset, Marie; Rouel-Rabiau, Nadege; Samba, Antoine; Andreacchio, Antonio

2014-03-01

20

Heavy metal displacement in salt-water-irrigated soil during phytoremediation  

International Nuclear Information System (INIS)

In regions where phytoremediation is carried out, brackish water must often be used. However, no information exists concerning the consequences of saline-water irrigation on the mobility of heavy metals in sludge applied to soil during phytoremediation. The purpose of this experiment was to determine the effect of NaCl irrigation on displacement of seven heavy metals in sludge (Cd, Cu, Fe, Mn, Ni, Pb, Zn) applied to the surface of soil columns containing barley plants. Half the columns received NaCl irrigation (10,000 mg L-1) and half the columns received tap-water irrigation. Half the columns were treated with the chelating agent EDTA. With no EDTA, irrigation with the NaCl solution increased the concentrations of Cd, Fe, Mn, and Pb in the drainage water above drinking-water standards. Irrigation of sludge farms with brackish water is not recommended, because saline water increased the mobility of the heavy metals and they polluted the drainage water. - Irrigation with brackish water mobilizes heavy metals in contaminated soils

21

Water displacer rod with hollow annular support pellets having sealed internal voids  

International Nuclear Information System (INIS)

This patent describes in a fuel assembly for use in a nuclear reactor having moderator-coolant liquid flowing therein, the fuel assembly including an organized array of nuclear fuel rods and at least one improved water displacer rod disposed among the fuel rods for displacing a portion of the moderator-coolant liquid flowing along the fuel rods. The displacer rod consists of (a) an elongated hollow hermetically-sealed tubular member; and (b) pellets composed of a material substantially transparent to neutrons and disposed in a stacked relationship within the tubular member throughout the length of the member, each of at least a substantial number of the pellets having (i) a body with opposite ends and a hollow annular cross-sectional shape defining a central void through the pellet, the central void of the body being substantially transparent to neutrons, and (ii) a solid web extending across and connected with at least one of the opposite ends of the body so as to close the void at the one body end such that the body end such that the respective voids of the bodies of the pellets disposed in the stacked relationship are enclosed individually one from the next

22

Near-infrared studies of glucose and sucrose in aqueous solutions: water displacement effect and red shift in water absorption from water-solute interaction  

CERN Document Server

We use near infrared spectroscopy to obtain concentration dependent glucose absorption spectra in their aqueous solutions in the near-infrared range (3800 - 7500 cm^{-1}). We introduce a new method to obtain reliable glucose absorption bands from aqueous glucose solutions without measuring the water displacement coefficients of glucose separately. Additionally, we are able to extract the water displacement coefficients of glucose, and this may give a new general method using spectroscopy techniques applicable to other water soluble materials. We also observe red shifts in the absorption bands of water in the hydration shell around solute molecules, which comes from contribution of the interacting water molecules around the glucose molecules in solutions. The intensity of the red shift get larger as the concentration increases, which indicates that as the concentration increases more water molecules are involved in the interaction. However, the red shift in frequency does not seem to depend significantly on th...

Jung, Youngeui

2013-01-01

23

Nozzle optimization for water jet propulsion with a positive displacement pump  

Science.gov (United States)

In the water jet propulsion system with a positive displacement (PD) pump, the nozzle, which converts pressure energy into kinetic energy, is one of the key parts exerting great influence on the reactive thrust and the efficiency of the system due to its high working pressure and easily occurring cavitation characteristics. Based on the previous studies of the energy loss and the pressure distribution of different nozzles, a model of water jet reactive thrust, which fully takes the energy loss and the nozzle parameters into consideration, is developed to optimize the nozzle design. Experiments and simulations are carried out to investigate the reactive thrust and the conversion efficiency of cylindrical nozzles, conical nozzles and optimized nozzles. The results show that the optimized nozzles have the largest reactive thrust and the highest energy conversion efficiency under the same inlet conditions. The related methods and conclusions are extended to the study of other applications of the water jet, such as water jet cutting, water mist fire suppression, water injection molding.

Yang, You-sheng; Xie, Ying-chun; Nie, Song-lin

2014-06-01

24

STRESS, STRAIN AND DISPLACEMENT OF A FUNCTIONALLY GRADED THICK SPHERICAL VESSEL  

Directory of Open Access Journals (Sweden)

Full Text Available This work aims at the determination of the displacements, strains, and stresses from the general analytical solution of a functionally graded thick spherical vessel with the consideration that theproperties of the material i.e. modulus of elasticity, thermal expansion coefficient and thermal conductivity, vary with the power-law of radius and Poisson’s ratio remains constant. With the third kind thermal boundary conditions, with steady-state unidirectional radial heat conduction and general mechanical boundary conditions, the equilibrium equation reduces to Navier equation. A study of the equivalent stress is made to check whether yielding occurs.

P NAYAK,

2011-04-01

25

Evaluation of water displacement energetics in protein binding sites with grid cell theory.  

Science.gov (United States)

Excess free energies, enthalpies and entropies of water in protein binding sites were computed via classical simulations and Grid Cell Theory (GCT) analyses for three pairs of congeneric ligands in complex with the proteins scytalone dehydratase, p38? MAP kinase and EGFR kinase respectively. Comparative analysis is of interest since the binding modes for each ligand pair differ in the displacement of one binding site water molecule, but significant variations in relative binding affinities are observed. Protocols that vary in their use of restraints on protein and ligand atoms were compared to determine the influence of protein-ligand flexibility on computed water structure and energetics, and to assess protocols for routine analyses of protein-ligand complexes. The GCT-derived binding affinities correctly reproduce experimental trends, but the magnitude of the predicted changes in binding affinities is exaggerated with respect to results from a previous Monte Carlo Free Energy Perturbation study. Breakdown of the GCT water free energies into enthalpic and entropic components indicates that enthalpy changes dominate the observed variations in energetics. In EGFR kinase GCT analyses revealed that replacement of a pyrimidine by a cyanopyridine perturbs water energetics up three hydration shells away from the ligand. PMID:25600031

Gerogiokas, G; Southey, M W Y; Mazanetz, M P; Hefeitz, A; Bodkin, M; Law, R J; Michel, J

2015-04-01

26

The Energy and Water Emergency Module; A containerized solution for meeting the energy and water needs in protracted displacement situations  

DEFF Research Database (Denmark)

The world has faced many natural and man-made disasters in the past few years, resulting in millions of people living in temporary camps across the globe. The energy and clean water needs of the relief operators in such emergency situations are primarily satisfied by diesel engine based generators and importing clean water to the site, in certain cases even for several years after the emergency. This approach results in problems such as low security of supply and high costs. Especially targeting the prolonged displacement situations, this paper presents an alternative solution – the Energy and Water Emergency Module. The proposed solution aims towards reducing the dependency on fossil fuel in prolonged emergency situations to a minimum while including local energy sources in the energy supply in a flexible and reliable way. The proposed module is built in a standard 20 ft container, and encompasses hybrid generation from solar, wind and biomass, with the possibility of using fossil sources too thanks to a dual fuel gas engine. The module can work both in grid connected and stand-alone mode. In addition the module includes a water purification unit to meet the water needs of displaced population. A demonstration unit was assembled at the Royal Institute of Technology in Stockholm during the year 2012 as a ‘concept proof’, and is now being tested and optimized for future deployment on the field. Preliminary testing and modelling shows that the proposed solution can reliably support emergency situations, and is already cost competitive with the current water and energy supply solutions for emergency situations. © 2015 Elsevier Ltd. All rights reserved.

Nerini, Francesco Fuso; Valentini, Francesco

2015-01-01

27

Irradiation creep and void swelling of austenitic stainless steels at low displacement rates in light water energy systems  

International Nuclear Information System (INIS)

The majority of the high fluence data on the void swelling and irradiation creep of austenitic steels was generated at relatively high displacement rates characteristic of fast reactors. The application of these data to other reactor systems which operate at lower displacement rates requires that some estimate be made of the dependence of swelling and irradiation creep on displacement rate. Austenitic components in typical light water reactors (LWRs) experience displacement rates that are an order of magnitude or more lower than that found in fast reactors. Since irradiation creep has a component that is proportional to swelling, it is anticipated that irradiation creep will exhibit a sensitivity to displacement rate that is a direct expression of the dependence of swelling on displacement rate. Until recently, however, the non-swelling-related component of creep was also thought to exhibit its own dependence on displacement rate, increasing at lower fluxes. This perception originally arose from the work of Lewthwaite and Mosedale on irradiation creep of cold-worked steels in the Dounreay Fast Reactor at temperatures in the 270-350 C range. It now appears that this interpretation is incorrect and, in fact, the steady-state value of the non-swelling component of irradiation creep is relatively insensitive to displacement rate. The earlier perceived flux dependence appears to have arisen from a failure to properly separate the transient and steady-state regimes of irradransient and steady-state regimes of irradiation creep. As evidence begins to accumulate on void swelling of stainless steels at LWR-relevant displacement rates, voids are being observed at lower-than-expected temperatures and often at very low dpa levels, implying that the 'temperature shift' phenomenon may indeed be operating to increase swelling. It is demonstrated in this paper that if swelling exceeds ?10% at PWR-relevant temperatures, stainless steels become very brittle. (orig.)

28

Structured water molecules in the binding site of bromodomains can be displaced by cosolvent.  

Science.gov (United States)

Bromodomains are ?-helical bundles of approximately 110 residues that recognize acetylated lysine side chains mainly on histone tails. Bromodomains are known to play an important role in cancer and inflammation, and as such, significant efforts are being made to identify small-molecule inhibitors of these epigenetic reader proteins. Here, explicit solvent molecular dynamics (MD) simulations of two bromodomains (BAZ2B and CREBBP) are used to analyze the water molecules that seem to be conserved at the bottom of the acetyl-lysine binding site in most crystal structures of bromodomains. The MD runs suggest that the occupancy of the structured water molecules is influenced by conformational transitions of the loop that connects helices Z and A. Additional simulations in the presence of 50?molecules of cosolvent (i.e., 440?mM of dimethylsulfoxide, methanol, or ethanol) indicate that some of the structured water molecules can be displaced transiently. The residence time in the acetyl-lysine binding site is calculated to be about 1?ns, 2-5?ns, and 10-30?ns for methanol, ethanol, and dimethylsulfoxide, respectively, while the affinity of the three cosolvents for BAZ2B and CREBBP is in the range of 50-500?mM. The results described have implications for ligand design, suggesting that only structured water molecules that do not exchange with cosolvent should be maintained in crystal structures used for docking campaigns, and that hydroxy substituents should be incorporated in the ligand so as to map the structured water molecules replaced by (m)ethanol. PMID:23804246

Huang, Danzhi; Rossini, Emanuele; Steiner, Sandra; Caflisch, Amedeo

2014-03-01

29

An accurate higher order displacement model with shear and normal deformations effects for functionally graded plates  

Energy Technology Data Exchange (ETDEWEB)

Highlights: • We model through-thickness variation of material properties in functionally graded (FG) plates. • Effect of material grading index on deformations, stresses and natural frequency of FG plates is studied. • Effect of higher order terms in displacement models is studied for plate statics. • The benchmark solutions for the static analysis and free vibration of thick FG plates are presented. -- Abstract: Functionally graded materials (FGMs) are the potential candidates under consideration for designing the first wall of fusion reactors with a view to make best use of potential properties of available materials under severe thermo-mechanical loading conditions. A higher order shear and normal deformations plate theory is employed for stress and free vibration analyses of functionally graded (FG) elastic, rectangular, and simply (diaphragm) supported plates. Although FGMs are highly heterogeneous in nature, they are generally idealized as continua with mechanical properties changing smoothly with respect to spatial coordinates. The material properties of FG plates are assumed here to vary through thickness of plate in a continuous manner. Young's modulii and material densities are considered to be varying continuously in thickness direction according to volume fraction of constituents which are mathematically modeled here as exponential and power law functions. The effects of variation of material properties in terms of material gradation index on deformations, stresses and natural frequency of FG plates are investigated. The accuracy of present numerical solutions has been established with respect to exact three-dimensional (3D) elasticity solutions and the other models’ solutions available in literature.

Jha, D.K., E-mail: dkjha@barc.gov.in [Civil Engineering Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Kant, Tarun [Department of Civil Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076 (India); Srinivas, K. [Civil Engineering Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Singh, R.K. [Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2013-12-15

30

Water displacement by sewer infrastructure in the Grote Nete catchment, Belgium, and its hydrological regime effects  

Directory of Open Access Journals (Sweden)

Full Text Available Urbanization and especially impervious areas, in combination with wastewater treatment infrastructure, can exert several pressures on the hydrological cycle. These pressures were studied for the Grote Nete catchment in Belgium (8.18% impervious area and 3.89% effective impervious area, based on a combination of empirical and model-based approaches. The effective impervious area, combined with the extent of the wastewater collection regions which do not coincide with the natural catchment boundaries, was used as an indicator for the urbanization pressure. Our study revealed changes in the total upstream areas of the subcatchments between ?16% and +3%, and in upstream impervious areas between ?99% and +64%. These changes lead to important inter-catchment water transfers. Based on simulations with a physically-based and spatially-distributed hydrological catchment model, profound impacts of effective impervious area on infiltration and runoff were found. The model results show that the changes in impervious areas and related water displacements in and between catchments due to the installation of the wastewater treatment infrastructure severely impacted low flows, peak flows and seasonal trends. They moreover show that it is difficult, but of utmost importance, to incorporate these pressures and artificial processes in an accurate way during the development of hydrological models for urbanized catchments.

D. Vrebos

2013-06-01

31

Colorimetric sensing of anions in water using ratiometric indicator-displacement assay.  

Science.gov (United States)

The analysis of anions in water presents a difficult challenge due to their low charge-to-radius ratio, and the ability to discriminate among similar anions often remains problematic. The use of a 3×6 ratiometric indicator-displacement assay (RIDA) array for the colorimetric detection and identification of ten anions in water is reported. The sensor array consists of different combinations of colorimetric indicators and metal cations. The colorimetric indicators chelate with metal cations, forming the color changes. Upon the addition of anions, anions compete with the indicator ligands according to solubility product constants (K(sp)). The indicator-metal chelate compound changes color back dramatically when the competition of anions wins. The color changes of the RIDA array were used as a digital representation of the array response and analyzed with standard statistical methods, including principal component analysis and hierarchical clustering analysis. No confusion or errors in classification by hierarchical clustering analysis were observed in 44 trials. The limit of detection was calculated approximately, and most limits of detections of anions are well below ?M level using our RIDA array. The pH effect, temperature influence, interfering anions were also investigated, and the RIDA array shows the feasibility of real sample testing. PMID:22882818

Feng, Liang; Li, Hui; Li, Xiao; Chen, Liang; Shen, Zheng; Guan, Yafeng

2012-09-19

32

The central cell model: a mesoscopic hopping model for the study of the displacement autocorrelation function.  

Science.gov (United States)

On the mesoscale, the molecular motion in a microporous material can be represented as a sequence of hops between different pore locations and from one pore to the other. On the same scale, the memory effects in the motion of a tagged particle are embedded in the displacement autocorrelation function (DACF), the discrete counterpart of the velocity autocorrelation function (VACF). In this paper, a mesoscopic hopping model, based on a lattice-gas automata dynamics, is presented for the coarse-grained modeling of the DACF in a microporous material under conditions of thermodynamic equilibrium. In our model, that we will refer to as central cell model, the motion of one tagged particle is mimicked through probabilistic hops from one location to the other in a small lattice of cells where all the other particles are indistinguishable; the cells closest to the one containing the tagged particle are simulated explicitly in the canonical ensemble, whereas the border cells are treated as mean-field cells in the grand-canonical ensemble. In the present paper, numerical simulation of the central cell model are shown to provide the same results as a traditional lattice-gas simulation. Along with this a mean-field theory of self-diffusion which incorporates time correlations is discussed. PMID:21568499

Pazzona, F G; Gabrieli, A; Pintus, A M; Demontis, P; Suffritti, G B

2011-05-14

33

COMPARISON OF ABSOLUTE VOLUME CALCULATION METHODS WITH WATER-DISPLACEMENT TECHNIQUE FOR Mimosa scabrella BENTHAM .  

Directory of Open Access Journals (Sweden)

Full Text Available The observed volumes obtained by several volume calculation methods for the bole and sections of the bole of Mimosa scabrella trees were compared with theirs respective true volumes obtained by measurements in xylometer (water-displacement technique. Fifty four sample trees were felled and measured into several municipal districts of the Curitiba Metropolitan Region, in the Paraná State. The sample trees presented DBH from 7,2 to 29,5cm and were gruped in 4 DBH classes. The treatments statistically analysed were the xylometer (control; four absolute volume calculation procedures (Smalian, Huber, Newton and Centroid, each one with three different section lengths (1m, 2m and 4m; the four DBH classes configured the blocks for the statistical analysis. All the treatments presented significant statistic difference related to the xylometer. Amongst the absolute volume calculation procedures the Huber’s formula seems to be the most accurate, although having presented significant statistic difference related to the true volume.

Sebastião do Amaral Machado , ,, ,

2006-09-01

34

High-accuracy measurement of depth-displacement using a focus function and its cross- correlation in holographic PTV.  

Science.gov (United States)

We propose a method using a focus function and its cross-correlation to measure depth-position and precise depth-displacement. The focus function provides acceptable results in the determination of depth-position of a transparent particle, an opaque particle, and a red blood cell. However, positional errors and a short time interval can cause unreliable results in identifying depth-displacement (?z) and depth-directional velocity in digital holographic particle tracking velocimetry (DHPTV). To minimize the errors in ?z, we propose a method that directly obtains depth displacement from the cross-correlation of focus values between consecutive holograms. The feasibility of this method is demonstrated by quantitatively visualizing a 3D flow using HPTV. PMID:24977812

Seo, Kyung Won; Lee, Sang Joon

2014-06-30

35

Monitoring soil-water and displacement conditions leading to landslide occurrence in partially saturated clays  

Science.gov (United States)

Shallow landslides frequently occur during transient rainfall infiltration and under partially saturated conditions. However, a detailed analysis of what triggers them, particularly in clayey soils, is often hindered by the lack of field measurements. It is uncommon, in fact, to capture their occurrence in an instrumented natural slope. This paper presents results from an integrated field experiment monitoring the soil-water and displacement conditions that lead to the occurrence of a shallow landslide in partially saturated clays. The integration of a variety of experimental techniques allowed for the examination of interplay between soil hydrological and mechanical properties. This research also evaluates a slope stability model based on the suction stress concept. Since the model was applied after the occurrence of the landslide, the results are interpreted as a hind-casting technique for model evaluation. Nevertheless, the detailed field measurements acquired during the monitoring activity and the occurrence of a landslide during the experiment provided significant information on model parameters and data interpretation. The station provides remote satellite monitoring of data on weather variables, soil water content and soil suction. A time domain reflectometry cable was installed vertically to detect potential soil failure. The experimental area had a high probability of landslide occurrence. Indeed, slope failure occurred during the observation period, showing the effectiveness of the station in detecting the occurrence, time and depth of landslides. The landslide was triggered in consequence of changes in suction stress. The failure plane occurred at a depth of 1.4 m, corresponding to the interface between a superficial layer of higher permeability of 1 to 1.45 m thickness, slipping over a compacted substrate having lower permeability. The analysis allowed for testing of the validity of the model and the description of the triggering mechanisms of the observed shallow landslide in unsaturated conditions, indicating that oscillations in soil matric suction were the dominant variables determining soil failure.

Bittelli, Marco; Valentino, Roberto; Salvatorelli, Fiorenzo; Rossi Pisa, Paola

2012-11-01

36

Simple model of bouncing ball dynamics. Displacement of the limiter assumed as a cubic function of time  

OpenAIRE

Nonlinear dynamics of a bouncing ball moving vertically in a gravitational field and colliding with a moving limiter is considered and the Poincare map, describing evolution from an impact to the next impact, is described. Displacement of the limiter is assumed as periodic, cubic function of time. Due to simplicity of this function analytical computations are possible. Several dynamical modes, such as fixed points, 2 - cycles and chaotic bands are studied analytically and nu...

Okninski, Andrzej; Radziszewski, Boguslaw

2012-01-01

37

Assessing Climate Change Impacts on Water Resources and Colorado Agriculture Using an Equilibrium Displacement Mathematical Programming Model  

OpenAIRE

This research models selected impacts of climate change on Colorado agriculture several decades in the future, using an Economic Displacement Mathematical Programming model. The agricultural economy in Colorado is dominated by livestock, which accounts for 67% of total receipts. Crops, including feed grains and forages, account for the remainder. Most agriculture is based on irrigated production, which depends on both groundwater, especially from the Ogallala aquifer, and surface water that c...

Eihab Fathelrahman; Amalia Davies; Stephen Davies; James Pritchett

2014-01-01

38

Pore-scale simulation of liquid CO2 displacement of water using a two-phase lattice Boltzmann model  

Science.gov (United States)

A lattice Boltzmann color-fluid model, which was recently proposed by Liu et al. (2012) based on a concept of continuum surface force, is improved to simulate immiscible two-phase flows in porous media. The new improvements allow the model to account for different kinematic viscosities of both fluids and to model fluid-solid interactions. The capability and accuracy of this model is first validated by two benchmark tests: a layered two-phase flow with a variable viscosity ratio, and a dynamic capillary intrusion. This model is then used to simulate liquid CO2 (LCO2) displacing water in a dual-permeability pore network. The extent and behavior of LCO2 preferential flow (i.e., fingering) is found to depend on the capillary number (Ca), and three different displacement patterns observed in previous micromodel experiments are reproduced. The predicted variation of LCO2 saturation with Ca, as well as variation of specific interfacial length with LCO2 saturation, are both in reasonable agreement with the experimental observations. To understand the effect of heterogeneity on pore-scale displacement, we also simulate LCO2 displacing water in a randomly heterogeneous pore network, which has the same size and porosity as the simulated dual-permeability pore network. In comparison to the dual-permeability case, the transition from capillary fingering to viscous fingering occurs at a higher Ca, and LCO2 saturation is higher at low Ca but lower at high Ca. In either pore network, the LCO2-water specific interfacial length is found to obey a power-law dependence on LCO2 saturation.

Liu, Haihu; Valocchi, Albert J.; Werth, Charles; Kang, Qinjun; Oostrom, Mart

2014-11-01

39

Pore-scale simulation of liquid CO2 displacement of water using a two-phase lattice Boltzmann model  

Energy Technology Data Exchange (ETDEWEB)

A lattice Boltzmann color-fluid model, which was recently proposed by Liu et al. [H. Liu, A.J. Valocchi, and Q. Kang. Three-dimensional lattice Boltzmann model for immiscible two-phase flow simulations. Phys. Rev. E, 85:046309, 2012.] based on a concept of continuum surface force, is improved to simulate immiscible two-phase flows in porous media. The new improvements allow the model to account for different kinematic viscosities of both fluids and to model fluid-solid interactions. The capability and accuracy of this model is first validated by two benchmark tests: a layered two-phase flow with a viscosity ratio, and a dynamic capillary intrusion. This model is then used to simulate liquid CO2 (LCO2) displacing water in a dual-permeability pore network. The extent and behavior of LCO2 preferential flow (i.e., fingering) is found to depend on the capillary number (Ca), and three different displacement patterns observed in previous micromodel experiments are reproduced. The predicted variation of LCO2 saturation with Ca, as well as variation of specific interfacial length with LCO2 saturation, are both in good agreement with the experimental observations. To understand the effect of heterogeneity on pore-scale displacement, we also simulate LCO2 displacing water in a randomly heterogeneous pore network, which has the same size and porosity as the dual-permeability pore network. In comparison to the dual-permeability case, the transition from capillary fingering to viscous fingering occurs at a higher Ca, and LCO2 saturation is higher at low Ca but lower at high Ca. In either pore network, the LCO2-water specific interfacial length is found to obey a power-law dependence on LCO2 saturation.

Liu, Haihu; Valocchi, Albert J.; Werth, Charles J.; Kang, Oinjun; Oostrom, Martinus

2014-11-01

40

Experimental study of crossover from capillary to viscous fingering for supercritical CO2-water displacement in a homogeneous pore network.  

Science.gov (United States)

Carbon sequestration in saline aquifers involves displacing brine from the pore space by supercritical CO(2) (scCO(2)). The displacement process is considered unstable due to the unfavorable viscosity ratio between the invading scCO(2) and the resident brine. The mechanisms that affect scCO(2)-water displacement under reservoir conditions (41 °C, 9 MPa) were investigated in a homogeneous micromodel. A large range of injection rates, expressed as the dimensionless capillary number (Ca), was studied in two sets of experiments: discontinuous-rate injection, where the micromodel was saturated with water before each injection rate was imposed, and continuous-rate injection, where the rate was increased after quasi-steady conditions were reached for a certain rate. For the discontinuous-rate experiments, capillary fingering and viscous fingering are the dominant mechanisms for low (logCa ? -6.61) and high injection rates (logCa ? -5.21), respectively. Crossover from capillary to viscous fingering was observed for logCa = -5.91 to -5.21, resulting in a large decrease in scCO(2) saturation. The discontinuous-rate experimental results confirmed the decrease in nonwetting fluid saturation during crossover from capillary to viscous fingering predicted by numerical simulations by Lenormand et al. (J. Fluid Mech.1988, 189, 165-187). Capillary fingering was the dominant mechanism for all injection rates in the continuous-rate experiment, resulting in monotonic increase in scCO(2) saturation. PMID:22676368

Wang, Ying; Zhang, Changyong; Wei, Ning; Oostrom, Mart; Wietsma, Thomas W; Li, Xiaochun; Bonneville, Alain

2013-01-01

41

Experimental study of crossover from capillary to viscous fingering for supercritical CO2 - water displacement in a homogeneous pore network  

Energy Technology Data Exchange (ETDEWEB)

Carbon sequestration in saline aquifers involves displacing resident brine from the pore space by supercritical CO2 (scCO2). The displacement process is considered unstable due to the unfavorable viscosity ratio (logM < 0). The unstable mechanisms that affect scCO2 - water displacement under reservoir conditions (i.e., 41 °C, 9 MPa) were investigated in a homogeneous micromodel. A wide range of injection rates (logCa = -7.61~-4.73) was studied in two sets of experiments: discontinuous-rate injection, where the micromodel was first cleaned and saturated with water before each injection rate was imposed, and continuous-rate injection, where the rate was increased after quasi-steady conditions were reached for a certain rate. For the discontinuous-rate experiments, capillary fingering and viscous fingering are the dominant mechanisms for low (logCa <= -6.61) and high injection rates (logCa >= -5.21), respectively. Crossover from capillary to viscous fingering was observed for logCa = -5.91~-5.21, resulting in a large decrease in scCO2 saturation. The discontinuous-rate experimental results confirmed the decrease in nonwetting fluid saturation during crossover from capillary to viscous fingering predicted by numerical simulations by Lenormand et al. (1988).1 Capillary fingering was the only mechanism that dominates all injection rates in the continuous-rate experiment, and resulted in monotonic increase in scCO2 saturation.

Wang, Ying; Zhang, Changyong; Wei, Ning; Oostrom, Martinus; Wietsma, Thomas W.; Li, Xiaochun; Bonneville, Alain

2013-01-01

42

Application of the Moliere multiple scattering angle-lateral displacement function in Monte-Carlo calculations  

International Nuclear Information System (INIS)

A two-dimensional approximation is found for the multiple scattering angle-lateral displacement correlation formula which satisfies two conditions: first, that it be close to the Moliere one (better than 10-3) and, second, that it be suitable for Monte Carlo calculations. These Monte Carlo calculations are made for relativistic particles. (orig.)

43

Molecular simulations with solvent competition quantify water displaceability and provide accurate interaction maps of protein binding sites.  

Science.gov (United States)

Binding sites present well-defined interaction patterns that putative ligands must meet. Knowing them is essential to guide structure-based drug discovery projects. However, complex aspects of molecular recognition-such as protein flexibility or the effect of aqueous solvation-hinder accurate predictions. This is particularly true for polar contacts, which are heavily influenced by the local environment and the behavior of discrete water molecules. Here we present and validate MDmix (Molecular Dynamics simulations with mixed solvents) as a method that provides much more accurate interaction maps than ordinary potentials (e.g., GRID). Additionally, MDmix also affords water displaceability predictions, with advantages over methods that use pure water as solvent (e.g., inhomogeneous fluid solvation theory). With current MD software and hardware solutions, predictions can be obtained in a matter of hours and visualized in a very intuitive manner. Thus, MDmix is an ideal complement in everyday structure-based drug discovery projects. PMID:25275946

Alvarez-Garcia, Daniel; Barril, Xavier

2014-10-23

44

Functional Outcome and Patient Satisfaction after Displaced Intra-articular Calcaneal Fractures: A Comparison Among Open, Percutaneous, and Nonoperative Treatment.  

Science.gov (United States)

The aim of the present study was to compare the outcomes of patients with a displaced calcaneal fracture treated by open reduction and internal fixation (ORIF), percutaneous treatment, or nonoperative methods. A retrospective cohort study was conducted at a level I trauma center of patients with a displaced intra-articular calcaneal fracture treated from January 1, 2002 to December 31, 2011. The patient-reported outcome measures included the Foot Function Index, American Orthopaedic Foot and Ankle Society hindfoot scale, Short Form-36, the EQ-5D from the EuroQol Group, and a 10-point visual analog scale. Clinical data were collected from 169 patients, and questionnaires were obtained from 78 patients (18 nonoperatively, 27 ORIF, and 33 percutaneously). The late intervention rate was significantly greater in the percutaneous group (n = 18; 30%) than in the ORIF group (n = 6; 12%) or the nonoperative group (n = 8; 13%; p = .030). Significantly more disability was reported in the nonoperative group (median Foot Function Index score, 40 points) than in the ORIF group (median, 16 points; p = .010) or in the percutaneous group (median, 21 points; p = .034). In conclusion, the operatively treated patients (ORIF and percutaneous treatment) reported better functional outcome scores (Foot Function Index and American Orthopaedic Foot and Ankle Society hindfoot scale) than did the nonoperatively treated patients. PMID:24891090

De Boer, A Siebe; Van Lieshout, Esther M M; Den Hartog, Dennis; Weerts, Bas; Verhofstad, Michael H J; Schepers, Tim

2014-05-30

45

Water Production Functions For High Plains Crops  

Science.gov (United States)

Increasing demands on limited water supplies will require maximizing crop production per unit water. Field studies are being carried out near Greeley, Colorado to develop water production functions for crops grown in the Great Plains. These yield per unit water relationships can be used to determi...

46

Influence of Viscous and Capillary Forces on Immiscible Fluid Displacement: Pore-Scale Experimental Study in a Water-Wet Micromodel Demonstrating Viscous and Capillary Fingering  

Energy Technology Data Exchange (ETDEWEB)

Unstable immiscible fluid displacement in porous media affects geological carbon sequestration, enhanced oil recovery, and groundwater contamination by nonaqueous phase liquids. Characterization of immiscible displacement processes at the pore-scale is important to better understand macroscopic processes at the continuum-scale. A series of displacement experiments was conducted to investigate the impacts of viscous and capillary forces on displacement stability and fluid saturation distributions in a homogeneous water-wet pore network micromodel with precisely-microfabricated pore structures. Displacements were studied using seven wetting-nonwetting fluid pairs with viscosity ratios M (viscosity of the advancing nonwetting fluid divided by the viscosity of the displaced wetting fluid) ranging four orders of magnitude from logM = -1.95 to 1.88. The micromodel was initially saturated with either polyethylene glycol 200 (PEG200) or water as a wetting fluid, which was then displaced by a nonwetting alkane fluid under different flow rates. Capillary numbers (Ca) ranged over four orders of magnitude for the reported experiments, from logCa = -5.88 to -1.02. Fluorescent microscopy was used to visualize displacement and measure nonwetting fluid saturation distributions. These experiments extend the classical work by Lenormand et al. by using water-wet micromodels, high-precision fabrication, and enhanced image analysis of the saturation distributions. In the micromodel experiments initially saturated with PEG200, a viscous wetting fluid, unstable displacement occurred by viscous fingering over the whole range of imposed capillary numbers. For the experiments initially saturated with water, unstable displacement occurred by capillary fingering at low capillary numbers. When the viscous forces were increased by increasing the injection rate, crossover into stable displacement was observed for the fluid pairs with M > 0. For unstable displacement experiments applying the same capillary number for the various fluid pairs, nonwetting fluid saturations were higher when capillary fingering was the dominant fingering process compared to viscous fingering. Our saturation distributions are consistent with other published experimental work and confirm the numerical results obtained by Lenormand et al.

Zhang, Changyong; Oostrom, Martinus; Wietsma, Thomas W.; Grate, Jay W.; Warner, Marvin G.

2011-08-18

47

Pore invasion dynamics during fluid front displacement in porous media determine functional pore size distribution and phase entrapment  

Science.gov (United States)

Dynamics of fluid fronts in porous media shape transport properties of the unsaturated zone and affect management of petroleum reservoirs and their storage properties. What appears macroscopically as smooth and continuous motion of a displacement fluid front may involve numerous rapid interfacial jumps often resembling avalanches of invasion events. Direct observations using high-speed camera and pressure sensors in sintered glass micro-models provide new insights on the influence of flow rates, pore size, and gravity on invasion events and on burst size distribution. Fundamental differences emerge between geometrically-defined pores and "functional" pores invaded during a single burst (invasion event). The waiting times distribution of individual invasion events and decay times of inertial oscillations (following a rapid interfacial jump) are characteristics of different displacement regimes. An invasion percolation model with gradients and including the role of inertia provide a framework for linking flow regimes with invasion sequences and phase entrapment. Model results were compared with measurements and with early studies on invasion burst sizes and waiting times distribution during slow drainage processes by Måløy et al. [1992]. The study provides new insights into the discrete invasion events and their weak links with geometrically-deduced pore geometry. Results highlight factors controlling pore invasion events that exert strong influence on macroscopic phenomena such as front morphology and residual phase entrapment shaping hydraulic properties after the passage of a fluid front.

Moebius, F.; Or, D.

2012-12-01

48

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

International Nuclear Information System (INIS)

Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and 15N. Its great advantage over radioactive tracers (e.g. tritium), which outweighs their extreme sensitivity and ease of measurement and which it has in common with stable isotopes, is that it does not require radiation protection measures. However, there are also constraints on the use of bromide as a tracer in soil/water/plant systems. Our own studies on different soils using D2O, bromide and [15N]-nitrate in lysimeters suggest that the above assumptions on bromide tracers need not always be valid under conditions as they prevail in biologically active soils. As the present paper shows, these studies permit a good assessment of the possibilities and limits to these tracers

49

Effective electron displacements: A tool for time-dependent density functional theory computational spectroscopy  

International Nuclear Information System (INIS)

We extend our previous definition of the metric ?r for electronic excitations in the framework of the time-dependent density functional theory [C. A. Guido, P. Cortona, B. Mennucci, and C. Adamo, J. Chem. Theory Comput. 9, 3118 (2013)], by including a measure of the difference of electronic position variances in passing from occupied to virtual orbitals. This new definition, called ?, permits applications in those situations where the ?r-index is not helpful: transitions in centrosymmetric systems and Rydberg excitations. The ?-metric is then extended by using the Natural Transition Orbitals, thus providing an intuitive picture of how locally the electron density changes during the electronic transitions. Furthermore, the ? values give insight about the functional performances in reproducing different type of transitions, and allow one to define a “confidence radius” for GGA and hybrid functionals

50

Effective electron displacements: a tool for time-dependent density functional theory computational spectroscopy.  

Science.gov (United States)

We extend our previous definition of the metric ?r for electronic excitations in the framework of the time-dependent density functional theory [C. A. Guido, P. Cortona, B. Mennucci, and C. Adamo, J. Chem. Theory Comput. 9, 3118 (2013)], by including a measure of the difference of electronic position variances in passing from occupied to virtual orbitals. This new definition, called ?, permits applications in those situations where the ?r-index is not helpful: transitions in centrosymmetric systems and Rydberg excitations. The ?-metric is then extended by using the Natural Transition Orbitals, thus providing an intuitive picture of how locally the electron density changes during the electronic transitions. Furthermore, the ? values give insight about the functional performances in reproducing different type of transitions, and allow one to define a "confidence radius" for GGA and hybrid functionals. PMID:24628146

Guido, Ciro A; Cortona, Pietro; Adamo, Carlo

2014-03-14

51

Light's Speed in Water (radical functions, modeling)  

Science.gov (United States)

2 days. Hands-on activity using the actual path of light through your container of water. Students compute the speed of light in water and develop an understanding of why light reflects back if below a critical angle. It provides an opportunity to build a fairly complicated function from simpler ones in a physical setting, and then investigate the function to learn something about the real world. It involves investigation of function with a parameter. This unit is appropriate for a precalculus course in a unit on functions or or in a unit on functions involving radicals. It has also been used in elementary calculus courses as a conceptual introduction to optimization.

2011-01-01

52

Tests of Dielectric Model Descriptions of Chemical Charge Displacements in Water  

CERN Document Server

A dielectric model of electrostatic solvation is applied to describe potentials of mean force in water along reaction paths for: a) formation of a sodium chloride ion pair; b) the symmetric SN2 exchange of chloride in methylchloride; and c) nucleophilic attack of formaldehyde by hydroxide anion. For these cases simulation and XRISM results are available for comparison. The accuracy of model predictions varies from spectacular to mediocre. It is argued that: a) dielectric models are physical models, even though simplistic and empirical; b) their successes suggest that second-order perturbation theory is a physically sound description of free energies of electrostatic solvation; and c) the most serious deficiency of the dielectric models lies in the definition of cavity volumes. Second-order perturbation theory should therefore be used to refine the dielectric models. These dielectric models make no attempt to assess the role of packing effects but for solvation of classical electrostatic interactions the diele...

Tawa, G J; Tawa, Gregory J.; Pratt, Lawrence R.

1994-01-01

53

Water displacement by sewer infrastructure in the Grote Nete catchment, Belgium, and its hydrological regime effects  

Science.gov (United States)

Urbanization and especially increases in impervious areas, in combination with the installation of wastewater treatment infrastructure, can impact the runoff from a catchment and river flows in a significant way. These effects were studied for the Grote Nete catchment in Belgium based on a combination of empirical and model-based approaches. Effective impervious area, combined with the extent of the wastewater collection regions, was considered as an indicator for urbanization pressure. It was found that wastewater collection regions ranging outside the boundaries of the natural catchment boundaries caused changes in upstream catchment area between -16 and +3%, and upstream impervious areas between -99 and +64%. These changes lead to important intercatchment water transfers. Simulations with a physically based and spatially distributed hydrological catchment model revealed not only significant impacts of effective impervious area on seasonal runoff volumes but also low and peak river flows. Our results show the importance, as well as the difficulty, of explicitly accounting for these artificial pressures and processes in the hydrological modeling of urbanized catchments.

Vrebos, D.; Vansteenkiste, T.; Staes, J.; Willems, P.; Meire, P.

2014-03-01

54

Assessing Climate Change Impacts on Water Resources and Colorado Agriculture Using an Equilibrium Displacement Mathematical Programming Model  

Directory of Open Access Journals (Sweden)

Full Text Available This research models selected impacts of climate change on Colorado agriculture several decades in the future, using an Economic Displacement Mathematical Programming model. The agricultural economy in Colorado is dominated by livestock, which accounts for 67% of total receipts. Crops, including feed grains and forages, account for the remainder. Most agriculture is based on irrigated production, which depends on both groundwater, especially from the Ogallala aquifer, and surface water that comes from runoff derived from snowpack in the Rocky Mountains. The analysis is composed of a Base simulation, designed to represent selected features of the agricultural economy several decades in the future, and then three alternative climatic scenarios are run. The Base starts with a reduction in agricultural water by 10.3% from increased municipal and industrial water demand, and assumes a 75% increase in corn extracted-ethanol production. From this, the first simulation (S1 reduces agricultural water availability by a further 14.0%, for a combined decrease of 24.3%, due to climatic factors and related groundwater depletion. The second simulation (S2-WET describes wet year conditions, which negatively affect yields of irrigated corn and milking cows, but improves yields for important crops such as non-irrigated wheat and forages. In contrast, the third simulation (S3-DRY describes a drought year, which leads to reduced dairy output and reduced corn and wheat. Consumer and producer surplus losses are approximately $10 million in this simulation. The simulation results also demonstrate the importance of the modeling trade when studying climate change in a small open economy, and of linking crop and livestock activities to quantify overall sector effects. This model has not taken into account farmers’ adaptation strategies, which would reduce the climate impact on yields, nor has it reflected climate-induced shifts in planting decisions and production practices that have environmental impacts or higher costs. It also focuses on a comparative statics approach to the analysis in order to identify several key effects of changes in water availability and yields, without having a large number of perhaps confounding assumptions.

Eihab Fathelrahman

2014-06-01

55

Complications and functional outcome after internal fixation of dorsally displaced distal radial fractures  

DEFF Research Database (Denmark)

Background: Recently there has been an increasing interest in open reduction and internal fixation of distal radius fractures. Even so further studies are still needed. Purpose: To document the functional outcome and identify complica- tions among patients treated with a volar locking plate (DVR-locking plate, DePuy Orthopaedics) newly introduced in our department. Methods: The study was designed as a historical cohort study. 37 females and 6 males with a mean (CI) age of 72,6 (69,5-75,6) were included. 35 received 6 months follow up (median 6,4) and 30 received 1 year follow up (median 14,0). Outcome measures included the Dis- ability of the Arm, shoulder and Hand (DASH) questionnaire, grip strength, active wrist and forearm range of motion and radiographic parameters. Findings: The mean DASH score was 15,5 (10,5- 20,6) at 6 months and 6,3 (2,5-10) at 1 year. There were at 1 year statistical significant differ- ence between thefractured and non-fractured wrist for flexion, extension and grip strength but not for supination and pronation. X-rays showed an improvement from preoperative to postoperative in dorsal angulation (17,7 degrees), inclination (6,6 degrees) and radial length (4,8 mm). A total of 10 major complications were identified: 4 had screws in the joint, 2 tendon ruptures, 2 plates were removed, 1 carpal tunnel syn- drome, 1 lacking radiological healing. There were no association between major complications and the surgeons experience level (> 10 operations). Evaluation of the X-ray images showed 14 cases of too radi- al plate placement and 1 one forgotten tower. Conclusion: The literature describes an overall complication frequency between 0 and 27%, with a lower frequency of secondary procedures compared to this study. There is still a need for further studies

Bove, Jeppe; Viberg, Bjarke

56

Effects of Buoyancy Forces on Immiscible Water/Oil Displacements in a Vertically Oriented Porous Medium Effets des facteurs de flottabilité sur les déplacements non-miscibles eau/huile dans un milieu poreux vertical  

OpenAIRE

The effects of buoyancy forces on liquid-liquid displacement processes occurring in porous media are important in a variety of practical situations, in particular during the displacement of oil from partially-depleted underground reservoirs by means of aqueous solutions. Most previous studies involving the visualization of water/oil displacements in porous media have been undertaken in horizontal two-dimensional porous medium cells. The objective of the present work was to determine the effec...

Thirunavu S. R.; Neale G. H.

2006-01-01

57

Triplet correlation functions in liquid water  

Science.gov (United States)

Triplet correlations have been shown to play a crucial role in the transformation of simple liquids to anomalous tetrahedral fluids [M. Singh, D. Dhabal, A. H. Nguyen, V. Molinero, and C. Chakravarty, Phys. Rev. Lett. 112, 147801 (2014)]. Here we examine triplet correlation functions for water, arguably the most important tetrahedral liquid, under ambient conditions, using configurational ensembles derived from molecular dynamics (MD) simulations and reverse Monte Carlo (RMC) datasets fitted to experimental scattering data. Four different RMC data sets with widely varying hydrogen-bond topologies fitted to neutron and x-ray scattering data are considered [K. T. Wikfeldt, M. Leetmaa, M. P. Ljungberg, A. Nilsson, and L. G. M. Pettersson, J. Phys. Chem. B 113, 6246 (2009)]. Molecular dynamics simulations are performed for two rigid-body effective pair potentials (SPC/E and TIP4P/2005) and the monatomic water (mW) model. Triplet correlation functions are compared with other structural measures for tetrahedrality, such as the O-O-O angular distribution function and the local tetrahedral order distributions. In contrast to the pair correlation functions, which are identical for all the RMC ensembles, the O-O-O triplet correlation function can discriminate between ensembles with different degrees of tetrahedral network formation with the maximally symmetric, tetrahedral SYM dataset displaying distinct signatures of tetrahedrality similar to those obtained from atomistic simulations of the SPC/E model. Triplet correlations from the RMC datasets conform closely to the Kirkwood superposition approximation, while those from MD simulations show deviations within the first two neighbour shells. The possibilities for experimental estimation of triplet correlations of water and other tetrahedral liquids are discussed.

Dhabal, Debdas; Singh, Murari; Wikfeldt, Kjartan Thor; Chakravarty, Charusita

2014-11-01

58

Triplet correlation functions in liquid water.  

Science.gov (United States)

Triplet correlations have been shown to play a crucial role in the transformation of simple liquids to anomalous tetrahedral fluids [M. Singh, D. Dhabal, A. H. Nguyen, V. Molinero, and C. Chakravarty, Phys. Rev. Lett. 112, 147801 (2014)]. Here we examine triplet correlation functions for water, arguably the most important tetrahedral liquid, under ambient conditions, using configurational ensembles derived from molecular dynamics (MD) simulations and reverse Monte Carlo (RMC) datasets fitted to experimental scattering data. Four different RMC data sets with widely varying hydrogen-bond topologies fitted to neutron and x-ray scattering data are considered [K. T. Wikfeldt, M. Leetmaa, M. P. Ljungberg, A. Nilsson, and L. G. M. Pettersson, J. Phys. Chem. B 113, 6246 (2009)]. Molecular dynamics simulations are performed for two rigid-body effective pair potentials (SPC/E and TIP4P/2005) and the monatomic water (mW) model. Triplet correlation functions are compared with other structural measures for tetrahedrality, such as the O-O-O angular distribution function and the local tetrahedral order distributions. In contrast to the pair correlation functions, which are identical for all the RMC ensembles, the O-O-O triplet correlation function can discriminate between ensembles with different degrees of tetrahedral network formation with the maximally symmetric, tetrahedral SYM dataset displaying distinct signatures of tetrahedrality similar to those obtained from atomistic simulations of the SPC/E model. Triplet correlations from the RMC datasets conform closely to the Kirkwood superposition approximation, while those from MD simulations show deviations within the first two neighbour shells. The possibilities for experimental estimation of triplet correlations of water and other tetrahedral liquids are discussed. PMID:25381528

Dhabal, Debdas; Singh, Murari; Wikfeldt, Kjartan Thor; Chakravarty, Charusita

2014-11-01

59

Spinal Cord Contusion Based on Precise Vertebral Stabilization and Tissue Displacement Measured by Combined Assessment to Discriminate Small Functional Differences  

OpenAIRE

Contusive spinal cord injury (SCI) is the most common type of spinal injury seen clinically. Several rat contusion SCI models have been described, and all have strengths and weaknesses with respect to sensitivity, reproducibility, and clinical relevance. We developed the Louisville Injury System Apparatus (LISA), which contains a novel spine-stabilizing device that enables precise and stable spine fixation, and is based on tissue displacement to determine the severity of injury. Injuries grad...

Zhang, Yi Ping; Burke, Darlene A.; Shields, Lisa B. E.; Chekmenev, Sergey Y.; Dincman, Toros; Zhang, Yongjie; Zheng, Yiyan; Smith, Rebecca R.; Benton, Richard L.; Devries, William H.; Hu, Xiaoling; Magnuson, David S. K.; Whittemore, Scott R.; Shields, Christopher B.

2008-01-01

60

The swelling of SS AISI 316L under dual beam irradiation as function of the displacement rate  

International Nuclear Information System (INIS)

The displacement rate dependence of swelling of austenitic stainless steel AISI 316L under dual beam irradiation was measured at T=898 K. For irradiation 25 keV He+ and 300 keV Ni+ ions were used. The material was investigated in the solution annealed state. Specimens were examined by TEM. Under all applied conditions bimodal cavity distributions were observed. After accounting for the cavity denuded zone of about 30 nm below the irradiated surface the results are free of any surface influence. Swelling was found to increase distinctly with decreasing displacement rate. This behaviour is due to the enhanced nucleation rate of small cavities at the higher displacement rates leading to a lower growth rate of the large cavities. Applying a model for cavity growth the bias of dislocations could be calculated to 15.4±3.3%. The capture efficiencies of cavities for defects had to be taken into account. Because of the cavity preference for interstitials this leads to a lower effective bias in the equation for cavity growth. This effective bias depends on the cavity size. (orig.)

61

Assessment of functional displacement of bone marrow by osteoplastic metastases from prostatic carcinoma with bone marrow scintigraphy  

International Nuclear Information System (INIS)

The detailed examination of the skeleton in prostate cancer has become more critical since surgical treatment requires the non-evidence of bone metastases. The data of 30 patients have been evaluated. All patients had a bone scan and a bone marrow scintigraphy with [99mTc[-anti-NCA95. In this study we compared the degree of bone marrow displacement with the extent of metastatic deposits identified on the bone scan. Six patients showing the criterias of a superscan (maximal avidity of the osteotrope radiatracer) had as a correlate a complete displacement of the hematopoesis in the bone marrow scintigraphy and an increased activity in liver and spleen. The degree of the peripheral extension correlated strongly with the decrease of the haemoglobin in blood samples. The grading was based upon the number of metastatic deposits identified on the scan (0=no metastases; 1?6 metastases; 2=multiple metastases; 3=superscan). In 28 of 30 patients (93%) we found corresponding results in both the bone scan and the bone marrow scintigraphy. The bone marrow scintigraphy is a sensitive method in the detection of metastatic disease and gives additional information about the extent of bone marrow displacement by osteoplastic metastases. (orig.)

62

The Van Hove Scattering Function for Water  

International Nuclear Information System (INIS)

Measurements, using the Chalk River rotating crystal spectrometer at a resolution of 2 x 10-4 eV, of the energy distributions of neutrons scattered by water at 25 and 75°C have been reported previously. From the results the Van Hove scattering function, S(Q, ?), was formed for wave vector transfers in the range 0.4 ? Q ? 2.0 Å-1 at 75°C and 0.4 ? Q ? 2. 6 Å-1at 25°C. Since, for the smaller values of Q used, the energy distributions for fixed Q show quasi-elastic peaks of widths much less than the resolution of the spectrometer, the results were analysed without constructing a scattering function which had been corrected for resolution. The previously reported S(Q, ?) have now been corrected for resolution. The correction has been carried out by assuming that S(Q, ?) can be represented by the quotient of a slowly varying function of e and a Lorentz function. It is found that in the region of the quasi-elastic peak S(Q, ?) can be represented by the Lorentzian form AW/?2 + W2) where A is slightly Q-dependent and W deviates only slightly from the value DQ2. D is a constant having values in good agreement with the values of the diffusion constant of water measured at the appropriate temperature. The resolution-corrected S(Q, ?) have been used to construct the frequency spectra of the velocity autocorrelation function. No evidence has been found for a dip near the origin caused by a partial separation of diffusive modes of motion from other types of modes. (author)

63

The importance function in water hammer problems  

International Nuclear Information System (INIS)

In a previous work the differential method was applied to the sensitivity analysis for water hammer problems in hydraulic networks. In this paper, the formalism is generalized to multi pipe components (namely concentrated losses - valves, bends, etc - tees, pumps, etc.). The corresponding adjoint component can be derived for any component in the direct problem. Moreover, an analogy is established in which transmission and reflection coefficients can be derived for any adjoint component. The importance or adjoint function is analyzed when the piezo metric head or velocity at a given position and time is chosen as response functional. In this case, it is shown that the importance function is represented by delta functions traveling along the hydraulic network with the propagation speed. The calculation of the sensitivity coefficients is extended to the cases in which the initial condition of the problem is the steady state and the parameters under consideration influence this initial condition. For this case, the calculation can be performed by solving sequentially two perturbative problems: the first one is non-steady, while the second one is steady, with an appropriate selection of a weighting function coming from unsteady perturbative problem. (author). 11 refs., 3 figs

64

Molecular Density Functional Theory of Water  

CERN Document Server

Three dimensional implementations of liquid state theories offer an efficient alternative to computer simulations for the atomic-level description of aqueous solutions in complex environments. In this context, we present a (classical) molecular density functional theory (MDFT) of water that is derived from first principles and is based on two classical density fields, a scalar one, the particle density, and a vectorial one, the multipolar polarization density. Its implementation requires as input the partial charge distribution of a water molecule and three measurable bulk properties, namely the structure factor and the k-dependent longitudinal and transverse dielectric constants. It has to be complemented by a solute-solvent three-body term that reinforces tetrahedral order at short range. The approach is shown to provide the correct three-dimensional microscopic solvation profile around various molecular solutes, possibly possessing H-bonding sites, at a computer cost two-three orders of magnitude lower tha...

Jeanmairet, Guillaume; Vuilleumier, Rodolphe; Borgis, Daniel; 10.1021/jz301956b

2013-01-01

65

Lateral displacement and rotational displacement sensor  

Science.gov (United States)

A position measuring sensor formed from opposing sets of capacitor plates measures both rotational displacement and lateral displacement from the changes in capacitances as overlapping areas of capacitors change. Capacitances are measured by a measuring circuit. The measured capacitances are provided to a calculating circuit that performs calculations to obtain angular and lateral displacement from the capacitances measured by the measuring circuit.

Duden, Thomas

2014-04-22

66

Flow injection on-line displacement/solid phase extraction system coupled with flame atomic absorption spectrometry for selective trace silver determination in water samples.  

Science.gov (United States)

A novel flow injection (FI) on-line displacement solid phase extraction preconcentration and/or separation method coupled with FAAS in order to minimize interference from other metals was developed for trace silver determination. The proposed method involved the on-line formation and subsequently pre-sorption of lead diethyldithiocarbamate (Pb-DDTC) into a column packed with PTFE-turnings. The preconcentration and/or separation of the Ag(I) took place through a displacement reaction between Ag(I) and Pb(II) of the pre-sorbed Pb-DDTC. Finally, the retained analyte was eluted with isobutyl methyl ketone (IBMK) and delivered directly to nebulizer for measuring. Interference from co-existing ions with lower DDTC complex stability in comparison with Pb-DDTC, was eliminated without need for any masking reagent. With 120 s of preconcentration time at a sample flow rate of 7.6 mL min(-1), an enhancement factor of 110 and a detection limit (3s) of 0.2 microg L(-1) were obtained. The precision (RSD, n=10) was 3.1% at the 10 mug L(-1) level. The developed method was successfully applied to trace silver determination in a variety of environmental water samples and certified reference material. PMID:19174217

Christou, Chrysoula K; Anthemidis, Aristidis N

2009-04-15

67

Study of oxide film formed in a pre cracked CT specimen of AISI 304L during a rising displacement test in 288 C water  

International Nuclear Information System (INIS)

A study of oxide film formed inside pre cracked CT specimens during a rising displacement test in high temperature water (288 C) was performed in this study, The environmental conditions used during the experiments were similar to these found in Boiling Water Reactors (BWR): Normal Water Condition (NWC - 200 ppb O2) and Hydrogen Water Chemistry (HWC - 125 ppb H2). The oxide films formed were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). In both cases the oxide film consisted of two layers identified as magnetite. In the case of HWC the results agree with previous reports that mention magnetite as a stable phase in reducing conditions. However the stable phase in oxidant conditions is hematite and this work shows the presence of magnetite crystals in the narrow crack of CT specimens in spite of the oxidant environmental condition. This situation confirms that inside the pre-cracked CT specimens the environmental conditions were different from the oxidant bulk, and probably a poor oxygen access and stagnant conditions within the narrow crack promoted a localized reducing environment that permitted the magnetite formation. Is evident that the crack growth studies should consider the conditions inside crack because they are significantly different. (Author)

68

Postsynthetic acetylation of histones during the cell cycle: a general function for the displacement of histones during chromatin rearrangements.  

Science.gov (United States)

Postsynthetic acetylation of core histones exhibits a peak during S-phase of the Physarum cell cycle. The maximum 3H-acetate incorporation precedes the maximum of histone synthesis. Acetate is incorporated into all core histones during S-phase, but only into H2A and H2B during G2-period. Resolution of acetylated H4-subspecies reveals acetate incorporation into preexisting H4, but not into newly synthesized molecules during mitosis and early S-phase. In a protamine competition assay histones from S-phase chromatin are released at lower protamine concentrations as compared to the lower acetylated G2-chromatin. We demonstrate a preferential release of highly acetylated H4-subspecies at low protamine concentrations. Our results fit into a general model of the relationship between histone acetylation and chromatin assembly. According to this model acetylation of core histones would serve as a signal for displacement of histones from nucleosomes by modulating histone-protein or histone-DNA interactions. We propose that this mechanism operates during DNA-replication and transcription, as well as during other chromatin rearrangements. PMID:3118335

Loidl, P; Gröbner, P

1987-10-26

69

The Role of Drinking Water Shortages on Human Psychological Functioning  

Directory of Open Access Journals (Sweden)

Full Text Available This study is grounded on an ecopsychological approach towards the effect of water shortages on human psychological functioning. The purpose of this study was to: (1 to examine the prevalence of psychological problems in rural residents with and without water shortages; (2 to evaluate human attributions about the possible causes of water scarcity; (3 to explore human coping styles towards water shortage; and (4 to recognize the role of sociocultural factors on the aforesaid factors. Participants included 3850 Iranian rural residents, those with water shortages (WWS, and those without water shortages (WOWS. A demographic questionnaire and several self-rating measures were used. Resulting data indicates that the prevalence of mental health problems is significantly higher in rural residents who suffer with water shortages. Attributional styles towards water shortages consisted of four components: personal, social, natural, and organizational. Coping styles of participants (with water shortages indicated an emotional-avoidant coping style, the utilization of water consumption methods to optimize water usage, the use of water-free technologies, social adaptation to life with regards to water, and the application of high quality technologies for water saving. Demographic and sociocultural factors influence psychological functioning with regards to water scarcity. This study demonstrates that mental health problems are more prevalent in areas with water shortages. It also indicates the impact of attributional styles, coping methods and the role of demographic and sociocultural factors on psychological functioning when water shortages occur,

Siamak Khodarahimi

2014-08-01

70

Irradiation damage 'displacement zone'  

International Nuclear Information System (INIS)

It is well known that a charged particle (ion, primary atom, etc...) moving in a solid slows down and can cause a cascade of displacements of the atoms in the solid. A study is made here of the extent to which the cascade is made up, or not, of independent collisions, as a function of the energy of the initial charged particle. When the distance between the collisions is small, these latter are no longer independent; the cascade, which then has to be considered as a whole, perturbs and locates, in the irradiated solid , a zone which has been named a 'displacement zone'. It is shown that the proportion of displacement zones increases with increasing atom size (high atomic number Z), with decreasing atomic distance D in the substance considered and with decreasing energy of the ion undergoing the slowing down process (although always remaining above a few hundred eV). The proportions obtained are higher than those corresponding to the calculations of J. A. Brinkman [3]. An interatomic potential required for this work has also been determined. (author)

71

Water Production Functions For High Plains Crops  

Science.gov (United States)

Declining water supplies is the critical resource issue for irrigated agriculture in the High Plains and much of the western U.S. Farmers need to maximize production per unit water consumed to remain economically viable and sustain irrigated agriculture. The Agricultural Research Service (ARS) Wat...

72

Generation of plastic influence functions for J-integral and crack opening displacement of thin-walled pipes with a short circumferential through-wall crack  

International Nuclear Information System (INIS)

Fracture mechanics parameters such as the J-integral and crack opening displacement (COD), are necessary for Leak-Before-Break (LBB) evaluation. The famous two estimation methods, the GE/EPRI and the Reference Stress Method (RSM), have their applicability limit with regard to the ratio of a pipe mean radius to thickness (Rm/t). In order to extend their applicability limit to a thin walled pipe, several finite element analyses are performed for the J-integral and COD, and then new plastic influence functions are developed for thin-walled pipes with a short circumferential through-wall crack. With the newly generated plastic influence functions, the GE/EPRI and the RSM give closer results with those obtained from detailed finite element analyses. In addition, C*-integral and COD rate are estimated by using the new plastic influence functions and they are well matched with elastic–creep finite element analysis results under the power-law creep condition. Since the LBB concept can be applied to a piping system in a Korean Sodium-cooled Fast Reactor (SFR) which is designed to have thin-walled pipes and to operate in high temperature enough to cause creep, this paper can be applied for the LBB assessment of thin-walled pipes with a short through-wall crack in the SFR

73

A molecular density functional theory to study solvation in water  

CERN Document Server

A classical density functional theory is applied to study solvation of solutes in water. An approx- imate form of the excess functional is proposed for water. This functional requires the knowledge of pure solvent direct correlation functions. Those functions can be computed by using molecular simulations such as molecular dynamic or Monte Carlo. It is also possible to use functions that have been determined experimentally. The functional minimization gives access to the solvation free energy and to the equilibrium solvent density. Some correction to the functional are also proposed to get the proper tetrahedral order of solvent molecules around a charged solute and to reproduce the correct long range hydrophobic behavior of big apolar solutes. To proceed the numerical minimization of the functional, the theory has been discretized on two tridimensional grids, one for the space coordinates, the other for the angular coordinates, in a functional minimization code written in modern Fortran, mdft. This program i...

Jeanmairet, Guillaume

2014-01-01

74

Leaf water absorption and desorption functions for three turfgrasses  

Science.gov (United States)

SummaryPlant leaf can absorb water when the leaf is in contact with water. This happens when the rainfall is intercepted by plant leaves, where the intercepted part of rain remains on the leaf surface. When the intercepted water is either absorbed or subsequently evaporated into the atmosphere, the plant leaves can dissipate water through the desorption process until the plant is dry or rewatered. In this paper, two symptomatic models in the form of exponential functions for leaf water absorption and leaf water desorption were derived and validated by experimental data using leaves of three turfgrasses (Tall fescue, Perennial ryegrass and Kentucky bluegrass). Both the models and measured data showed that the rate of leaf water absorption was high at the low initial leaf water content and then gradually leveled off toward the saturated leaf water content. The rate of leaf water desorption was high at the high initial leaf water content then decreased drastically over time toward zero. The different plant leaves showed different exponents and other parameters of the functions which indicate the difference of plant species. Both the absorption and desorption rates were relatively higher for the Kentucky bluegrass and lower for the Tall fescue and Perennial ryegrass. The concept of specific leaf area ( SLA) was used to understand the saturated leaf water content ( C s) of the three turfgrasses. Linear relationships were found between C s and SLA. The leaf water absorption and desorption functions are useful for deriving physiological parameters of the plant such as permanent wilting leaf water content, naturally irreducible leaf water content, exponential leaf water absorption coefficient, and exponential leaf desorption coefficient, as well as for evaluating the effects of rainfall interception on plant growth and water use efficiency.

Liang, Xi; Su, Derong; Yin, Shuxia; Wang, Zhi

2009-09-01

75

Molecular dynamics simulation of liquid water: Hybrid density functionals  

Energy Technology Data Exchange (ETDEWEB)

The structure, dynamical and electronic properties of liquid water utilizing different hybrid density functionals were tested within the plane wave framework of first principles molecular dynamics simulations. The computational approach, which employs modified functionals with short-ranged Hartree-Fock exchange, was first tested in calculations of the structural and bonding properties of the water dimer and cyclic water trimer. Liquid water simulations were performed at the state point of 350 K at the experimental density. Simulations included three different hybrid functionals, a meta functional, four gradient corrected functionals, the local density and Hartree-Fock approximation. It is found that hybrid functionals are superior in reproducing the experimental structure and dynamical properties as measured by the radial distribution function and self diffusion constant when compared to the pure density functionals. The local density and Hartree-Fock approximations show strongly over- and under-structured liquids, respectively. Hydrogen bond analysis shows that the hybrid functionals give slightly smaller averaged numbers of hydrogen bonds and similar hydrogen bond populations as pure density functionals. The average molecular dipole moments in the liquid from the three hybrid functionals are lower than from the corresponding pure density functionals.

Todorova, T; Seitsonen, A; Hutter, J; Kuo, W; Mundy, C

2005-09-12

76

Functional systems of a pressurized water reactor  

International Nuclear Information System (INIS)

The main topics, discussed in the present paper, are: - Principle design of the reactor coolant system - reactor pressure vessel with internals - containment design - residual heat removal and emergency cooling systems - nuclear component cooling systems - emergency feed water systems - plant electric power supply system. (orig./RW)

77

Assessment of Volume Measurement of Breast Cancer-Related Lymphedema by Three Methods: Circumference Measurement, Water Displacement, and Dual Energy X-Ray Absorptiometry  

DEFF Research Database (Denmark)

Background: Following treatment for breast cancer 12%-60% develop breast cancer-related lymphedema (BCRL). There are several ways of assessing BCRL. Circumference measurement (CM) and water displacement (WD) for volume measurements (VM) are frequently used methods in practice and research, respectively. The aim of this study was to evaluate CM and WD for VM of the BCRL arm and the contralateral arm, comparing the results with regional dual energy X-ray absorptiometry (DXA). Methods and Results: Twenty-four women with unilateral BCRL were included in the study. Blinded duplicate VM were obtained from both arms using the three methods mentioned above. CM and DXA were performed by two observers. WD was performed by a group of observers. Mean differences (d) in duplicated volumes, limits of agreement (LOA), and 95% confidence intervals (CI) were calculated for each method. The repeatability expressed as d (95% CI) between the duplicated VM of the BCRL arm and the contralateral arm was for DXA 3 ml (-6-11) and 3 ml (1-7), respectively. For CM and WD, the d (95% CI) of the BCRL arm were 107 ml (86-127) and 26 ml (-26-79), respectively and in the contralateral arm 100 ml (78-122) and 6 ml (-29-17), respectively. Conclusions: DXA is superior in repeatability when compared to CM and WD for VM, especially for the BCRL arm but also the contralateral arm

GjØrup, Caroline; Zerahn, B.

2010-01-01

78

Structure and dynamics of water inside endohedrally functionalized carbon nanotubes.  

Science.gov (United States)

We have carried out classical molecular dynamics simulations on the formation of extended water chains inside single-walled carbon nanotubes (SWCNTs) in water in the presence of selected functional groups covalently attached to the inner wall of the tube. Analogues of polar amino acid sidechains have been chosen to carry out the endohedral functionalization of SWCNTs. Our results show a spontaneous and asymmetric filling of the nanotube with dynamical water chains in all the cases studied. The presence of Asp- and Glu-like sidechains is found to result in the formation of well-ordered water chains across the tube having the maximum number of water molecules being retained within the core with the largest residence times. The presence of methyl or methylene groups along the suspended chain is observed to disrupt the formation of water chains with higher length and/or longer residence times. The importance of hydrogen bonding in forming these water chains is assessed in terms of the relaxations of different hydrogen bond correlation functions. For a given dimension of the hydrophobic nanopore, we thus obtain a scale comparing the ability of carboxylic, alcohol, and imidazole groups in controlling the structure and dynamics of water in it. Our results also suggest that SWCNTs of varying lengths, endohedrally functionalized with Asp- and Glu-like sidechains, may be used as design templates in CNT-based water storage devices. PMID:24832292

Paul, Sanjib; Abi, T G; Taraphder, Srabani

2014-05-14

79

MACROSCOPIC APPROACHES TO MODELING ROOT WATER UPTAKE AS A FUNCTION OF WATER AND SALINITY STRESS  

Science.gov (United States)

Analyzing irrigation, soil salinization, or crop production problems often requires simulations of root water uptake as a function of water and salinity stress. We give an overview of macroscopic modeling approaches that are based on the Richards equation with a sink term specifying water uptake. ...

80

Displacement ventilation in lecture halls  

OpenAIRE

This thesis considers several important goals. The main purpose is to see how displacement ventilation sys-tem works in the lecture hall of M-building and compare obtained results with D2 and Indoor Climate Classi-fication. The second one is to analyze the function of the ventilation system. The last one is to realize when displacement ventilation is preferable to mixing ventilation. Analysis of the system was carried out with instruments from MUAS HVAC laboratory. In lecture hall were me...

Egorov, Artem

2013-01-01

81

Displacement solid-phase extraction on mercapto-functionalized magnetite microspheres for inductively coupled plasma mass spectrometric determination of trace noble metals  

International Nuclear Information System (INIS)

A flow injection online displacement solid-phase extraction (DSPE) via magnetic immobilization of mercapto-functionalized magnetite microspheres onto the inner walls of a knotted reactor (KR) coupled with inductively coupled plasma mass spectrometry was developed for selective preconcentration and determination of trace noble metals (Ru, Rh, Pd, Pt, Ir and Au) in complex matrices. Online DSPE of 2.7 mL aqueous solution gave the enhancement factors of 32-46 for the six noble metals in comparison with direct nebulization of aqueous sample solution, and the detection limits (3 s) of 2.1 ng L-1 for Ru, 1.9 ng L-1 for Rh, 2.5 ng L-1 for Pd, 1.8 ng L-1 for Ir, 1.9 ng L-1 for Pt and 1.7 ng L-1 for Au. The sample throughput of the developed method was about 20 samples h-1, and the relative standard deviation for eleven replicate determinations of the noble metals at the 30 ng L-1 level ranged from 1.2% to 2.1%. The recoveries of Ru, Rh, Pd, Pt, Ir and Au still maintained 90% even after successive 140 cycles of DSPE. The developed method was successfully applied to selective determination of trace Ru, Rh, Pd, Pt, Ir and Au in complex matrices.

82

Water transport through functionalized nanotubes with tunable hydrophobicity  

Energy Technology Data Exchange (ETDEWEB)

Molecular dynamics simulations are used to study the occupancy and flow of water through nanotubes comprised of hydrophobic and hydrophilic atoms, which are arranged on a honeycomb lattice to mimic functionalized carbon nanotubes (CNTs). We consider single-file motion of TIP3P water through narrow channels of (6,6) CNTs with varying fractions (f) of hydrophilic atoms. Various arrangements of hydrophilic atoms are used to create heterogeneous nanotubes with separate hydrophobic/hydrophilic domains along the tube as well as random mixtures of the two types of atoms. The water occupancy inside the nanotube channel is found to vary nonlinearly as a function of f, and a small fraction of hydrophilic atoms (f ? 0.4) are sufficient to induce spontaneous and continuous filling of the nanotube. Interestingly, the average number of water molecules inside the channel and water flux through the nanotube are less sensitive to the specific arrangement of hydrophilic atoms than to the fraction, f. Two different regimes are observed for the water flux dependence on f – an approximately linear increase in flux as a function of f for f < 0.4, and almost no change in flux for higher f values, similar to the change in water occupancy. We are able to define an effective interaction strength between nanotube atoms and water's oxygen, based on a linear combination of interaction strengths between hydrophobic and hydrophilic nanotube atoms and water, that can quantitatively capture the observed behavior.

Moskowitz, Ian; Snyder, Mark A.; Mittal, Jeetain, E-mail: jeetain@lehigh.edu [Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015 (United States)

2014-11-14

83

Water transport through functionalized nanotubes with tunable hydrophobicity  

International Nuclear Information System (INIS)

Molecular dynamics simulations are used to study the occupancy and flow of water through nanotubes comprised of hydrophobic and hydrophilic atoms, which are arranged on a honeycomb lattice to mimic functionalized carbon nanotubes (CNTs). We consider single-file motion of TIP3P water through narrow channels of (6,6) CNTs with varying fractions (f) of hydrophilic atoms. Various arrangements of hydrophilic atoms are used to create heterogeneous nanotubes with separate hydrophobic/hydrophilic domains along the tube as well as random mixtures of the two types of atoms. The water occupancy inside the nanotube channel is found to vary nonlinearly as a function of f, and a small fraction of hydrophilic atoms (f ? 0.4) are sufficient to induce spontaneous and continuous filling of the nanotube. Interestingly, the average number of water molecules inside the channel and water flux through the nanotube are less sensitive to the specific arrangement of hydrophilic atoms than to the fraction, f. Two different regimes are observed for the water flux dependence on f – an approximately linear increase in flux as a function of f for f < 0.4, and almost no change in flux for higher f values, similar to the change in water occupancy. We are able to define an effective interaction strength between nanotube atoms and water's oxygen, based on a linear combination of interaction strengths between hydrophobic and hydrophilic nanotube atoms and water, that can quantitatively capture the observed behavior

84

Simulation of miscible laboratory displacements by the total dispersion method  

International Nuclear Information System (INIS)

The total dispersion method was developed to simulate first-contact miscible displacements performed in the laboratory. Simulations applying this method add sufficient dispersivity to the numerical dispersion inherent in finite differencing methods so the sum approximates the actual physical dispersion. This paper describes the application of this technique to model three floods taken from the literature and three displacements performed in a CT scanner. A key variable for modelling miscible displacements is dispersion. Numerical dispersion for both 1-point and 2-point upstream weighing was characterized as a function of grid block size and through put for an IMPES simulator. After quantifying numerical dispersion, three floods reported in the literature were simulated to confirm the total dispersion method. Recovery curves for two displacements dominated by viscous fingering that one exhibiting gravity override were modelled with good agreement. The authors' next objective was to determine if concentration profiles as well as recovery curves could be matched in a well characterized rock. First, longitudinal convective dispersion was measured for Bentheimer sandstone by a series of tritiated water displacements

85

No difference in the long term final functional outcome after nailing or cast bracing of high energy displaced tibial shaft fractures  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Cast bracing (CB has been a well established method of treating tibial shaft fractures. Majority of the recent literature on treatment of tibial shaft fractures have upheld intramedullary nailing (IMN as the treatment of choice. Most of these studies are from the west, in public funded health set ups and in hospitals with very low rates of infection. This has lead to bewilderment in the minds of surgeons wishing to opt for conservative treatment in countries with scarcity of health resources. We therefore undertook this study to compare the two modalities in the scenario of the developing world. Material and methods Sixty-eight consecutive patients were treated alternately with CB and IMN for high energy, displaced, closed and Gustilo Grade 1 open fractures of the tibial shaft, between 1995 and 2001. Results An average follow up at 4.3?years revealed no statistical difference in the final functional outcome as per Johner and Wruhs' criteria with modification to Indian lifestyle. IMN group had a slightly shorter time to fracture union (mean 21.3?weeks versus 23.1?weeks for CB, p?>?0.05, (b lesser time off work (mean 17.6?weeks versus 25.6?weeks for CB, p Conclusion Treating tibial shaft fracture either with IMN or CB provided equally gratifying results with no statistical difference in final functional outcome. The economic cost to the patient in Indian conditions is significantly less with CB and therefore stands as an equally reliable treatment option, especially in countries with fewer resources.

Batta Vineet

2012-06-01

86

Modelling toehold-mediated RNA strand displacement.  

Science.gov (United States)

We study the thermodynamics and kinetics of an RNA toehold-mediated strand displacement reaction with a recently developed coarse-grained model of RNA. Strand displacement, during which a single strand displaces a different strand previously bound to a complementary substrate strand, is an essential mechanism in active nucleic acid nanotechnology and has also been hypothesized to occur in vivo. We study the rate of displacement reactions as a function of the length of the toehold and temperature and make two experimentally testable predictions: that the displacement is faster if the toehold is placed at the 5' end of the substrate; and that the displacement slows down with increasing temperature for longer toeholds. PMID:25762335

Šulc, Petr; Ouldridge, Thomas E; Romano, Flavio; Doye, Jonathan P K; Louis, Ard A

2015-03-10

87

Modeling Displacement Measurement using Vibration Transducers  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents some aspects regarding to small displacement measurement using vibration transducers. Mechanical faults, usages, slackness’s, cause different noises and vibrations with different amplitude and frequency against the normal sound and movement of the equipment. The vibration transducers, accelerometers and microphone are used for noise and/or sound and vibration detection with fault detection purpose. The output signal of the vibration transducers or accelerometers is an acceleration signal and can be converted to either velocity or displacement, depending on the preferred measurement parameter. Displacement characteristics are used to indicate when the machine condition has changed. There are many problems using accelerometers to measure position or displacement. It is important to determine displacement over time. To determinate the movement from acceleration a double integration is needed. A transfer function and Simulink model was determinate for accelerometers with capacitive sensing element. Using these models the displacement was reproduced by low frequency input.

AGOSTON Katalin

2014-05-01

88

Modelling toehold-mediated RNA strand displacement  

CERN Document Server

We study the thermodynamics and kinetics of an RNA toehold-mediated strand displacement reaction with a recently developed coarse-grained model of RNA. Strand displacement, during which a single strand displaces a different strand previously bound to a complementary substrate strand, is an essential mechanism in active nucleic acid nanotechnology and has also been hypothesized to occur in vivo. We study the rate of displacement reactions as a function of the length of the toehold and temperature and make two experimentally testable predictions: that the displacement is faster if the toehold is placed at the 5' end of the substrate and that the displacement slows down with increasing temperature for longer toeholds.

Šulc, Petr; Romano, Flavio; Doye, Jonathan P K; Louis, Ard A

2014-01-01

89

Updated model for dielectric response function of liquid water  

International Nuclear Information System (INIS)

A modified and updated version of the model of the dielectric response function of liquid water as currently implemented in the PARTRAC code is presented. The updated version takes advantage of the newer experimental information from the Sendai group and implements some improvements in modeling and usability. - Highlights: ? Updated model of the dielectric response function and energy loss function of liquid water is presented. ? The new model includes new available experimental information (Sendai data). ? It is an analytical model. ? The mean excitation energy is calculated as 78.3 eV

90

????????????????????? Water Environmental Capacity Allocation Method for Water Function Area Based on Fairness  

Directory of Open Access Journals (Sweden)

Full Text Available ?????????????????????????????????????????????????????????????????????????????????????????????????????COD???????????????????????????0.47(??????0.29(?????????????????????????????????????????????????????????????????????????????????????????????????????Gini coefficient distribution method is one for water environmental capacity in the water functional area on the basis of the allocation principle of fairness and the criterion of Gini coefficient, with comprehensively considering a variety of factors. The example research shows that the ratio of COD capacity distribution accounting Gini coefficient of total industry production based on Gini coefficient distribution method is from 0.47 (unfairness down to 0.29 (relatively fairness through the water environmental capacity allocation of towns in the Dongyin Canal water function area in Dongguan City, the rest Gini coefficient of factors all are in the scope of fairness. The results display that, all Gini coefficient is in the range of fairness by more factors introduced to comprehensively evaluate and the distribution capacity of objects adjusted for Gini coefficient distribution method. Also, the water environmental capacity allocation in the water function area is more fair and reasonable.

???

2012-08-01

91

Measuring tidal displacement using GPS  

Science.gov (United States)

GPS is making possible high-precision, high-resolution measurements of tidal displacement that could not be achieved with other methods. Earth's surface deforms due to both body tides—the deformation of the solid Earth due to the pull of the Sun and the Moon—and ocean tides—the redistribution of water mass loading over Earth's surface. Body tides and ocean tides both have components that vary on semidiurnal, diurnal, and longer periods.

Balcerak, Ernie

2013-06-01

92

Effects of wettability and pore-level displacement on hydrocarbon trapping  

Science.gov (United States)

We use a three-dimensional mixed-wet random network model representing Berea sandstone to extend our previous work on relative permeability hysteresis during water-alternating-gas (WAG) injection cycles [Suicmez, VS, Piri, M, Blunt, MJ, 2007, Pore-scale simulation of water alternate gas injection, Transport Porous Med 66(3), 259-86]. We compute the trapped hydrocarbon saturation for tertiary water-flooding, which is water injection into different initial gas saturations, Sgi, established by secondary gas injection after primary drainage. Tertiary water-flooding is continued until all the gas and oil is trapped. We study four different wettability conditions: water-wet, weakly water-wet, weakly oil-wet and oil-wet. We demonstrate that the amounts of oil and gas that are trapped show surprising trends with wettability that cannot be captured using previously developed empirical trapping models. We show that the amount of oil that is trapped by water in the presence of gas increases as the medium becomes more oil-wet, which is opposite from that seen for two-phase flow. It is only through a careful analysis of displacement statistics and fluid configurations that these results can be explained. This illustrates the need to have detailed models of the displacement processes that represent the three-phase displacement physics as carefully as possible. Further work is needed to explore the full range of behavior as a function of wettability and displacement path.

Suicmez, V. Sander; Piri, Mohammad; Blunt, Martin J.

2008-03-01

93

Effects of Bridge Functions on Radial Distribution Functions of Liquid Water  

OpenAIRE

In this report the radial distribution functions (RDFs) of liquid water are calculated on the basis of the classical density functional theory combined with the reference interaction site model for molecular liquids. The bridge functions, which are neglected in the hypernetted-chain (HNC) approximation, are taken into account through the density expansion for the Helmholtz free energy functional up to the third order. A factorization approximation to the ternary direct corre...

Tanaka, Shigenori; Nakano, Miki

2014-01-01

94

Positive displacement liquid meters  

Energy Technology Data Exchange (ETDEWEB)

A discussion covers the importance of measuring petroleum liquid hydrocarbons from the well to the refinery and then on through the distribution of products via pipeline, bulk terminal, and tank truck to the ultimate consumer; the metering operations and the role of positive displacement meters throughout this complex system; and the theory of operation of the positive displacement meter.

Bloser, B.L.

1977-09-01

95

No difference in the long term final functional outcome after nailing or cast bracing of high energy displaced tibial shaft fractures  

Science.gov (United States)

Background Cast bracing (CB) has been a well established method of treating tibial shaft fractures. Majority of the recent literature on treatment of tibial shaft fractures have upheld intramedullary nailing (IMN) as the treatment of choice. Most of these studies are from the west, in public funded health set ups and in hospitals with very low rates of infection. This has lead to bewilderment in the minds of surgeons wishing to opt for conservative treatment in countries with scarcity of health resources. We therefore undertook this study to compare the two modalities in the scenario of the developing world. Material and methods Sixty-eight consecutive patients were treated alternately with CB and IMN for high energy, displaced, closed and Gustilo Grade 1 open fractures of the tibial shaft, between 1995 and 2001. Results An average follow up at 4.3?years revealed no statistical difference in the final functional outcome as per Johner and Wruhs' criteria with modification to Indian lifestyle. IMN group had a) slightly shorter time to fracture union (mean 21.3?weeks versus 23.1?weeks for CB, p?>?0.05), (b) lesser time off work (mean 17.6?weeks versus 25.6?weeks for CB, p <0.01), (c) fewer outpatient visits (mean 6.2 versus 9.7 for CB, p?functional outcome. The economic cost to the patient in Indian conditions is significantly less with CB and therefore stands as an equally reliable treatment option, especially in countries with fewer resources. PMID:22694876

2012-01-01

96

Aryl acrylate porous functional polymer supports from water-in-oil-in-water multiple emulsions  

OpenAIRE

Porous functional polymer supports are a class of material of wide interest due to the possibility of immobilising reactive species. A simplified procedure was applied for the preparation of porous polymer supports using a water-in-oil-in-water multiple emulsion. The primary emulsion was a high internal phase emulsion, having a volume fraction of water phase up to 95%. Two reactive acrylates, namely 4-nitrophenyl acrylate and 2,4,6-trichlorophenyl acrylate, were (separately) incorporated in t...

S?tefanec, Dejan; Krajnc, Peter

2012-01-01

97

MACROSCOPIC APPROACHES TO ROOT WATER UPTAKE AS A FUNCTION OF WATER AND SALINITY STRESS  

Science.gov (United States)

Computer simulation models can be important tools for analyzing and managing site-specific irrigation, soil salinization, or crop production problems. For many of these problems, computer analyses require simulations of root water uptake as a function of water and salinity stress. We give an over...

98

INVITED TOPICAL REVIEW: The 'wet mind': water and functional neuroimaging  

Science.gov (United States)

Functional neuroimaging has emerged as an important approach to study the brain and the mind. Surprisingly, although they are based on radically different physical approaches both positron emission tomography (PET) and magnetic resonance imaging (MRI) make brain activation imaging possible through measurements involving water molecules. So far, PET and MRI functional imaging have relied on the principle that neuronal activation and blood flow are coupled through metabolism. However, a new paradigm has emerged to look at brain activity through the observation with MRI of the molecular diffusion of water. In contrast with the former approaches diffusion MRI has the potential to reveal changes in the intrinsic water physical properties during brain activation, which could be more intimately linked to the neuronal activation mechanisms and lead to an improved spatial and temporal resolution. However, this link has yet to be fully confirmed and understood. To shed light on the possible relationship between water and brain activation, this introductory paper reviews the most recent data on the physical properties of water and on the status of water in biological tissues, and evaluates their relevance to brain diffusion MRI. The biophysical mechanisms of brain activation are then reassessed to reveal their intimacy with the physical properties of water, which may come to be regarded as the 'molecule of the mind'.

LeBihan, Denis

2007-04-01

99

Intrinsic Mean Square Displacements in Proteins  

CERN Document Server

The thermal mean square displacement (MSD) of hydrogen in proteins and its associated hydration water is measured by neutron scattering experiments and used an indicator of protein function. The observed MSD as currently determined depends on the energy resolution width of the neutron scattering instrument employed. We propose a method for obtaining the intrinsic MSD of H in the proteins, one that is independent of the instrument resolution width. The intrinsic MSD is defined as the infinite time value of that appears in the Debye-Waller factor. The method consists of fitting a model to the resolution broadened elastic incoherent structure factor or to the resolution dependent MSD. The model contains the intrinsic MSD, the instrument resolution width and a rate constant characterizing the motions of H in the protein. The method is illustrated by obtaining the intrinsic MSD of heparan sulphate (HS-0.4), Ribonuclease A and Staphysloccal Nuclase (SNase) from data in the literature.

Vural, Derya

2012-01-01

100

Intrinsic Mean Square Displacement in Lysozyme  

Science.gov (United States)

The internal dynamics of proteins is the essential interest of biophysics. The mean square displacement (MSD) of hydrogen in proteins and its associated hydration water is obtained by molecular dynamic (MD) simulation. The MSD as currently determined depends on the time of the MD simulation. A method is proposed in this paper to obtain the intrinsic MSD of hydrogen in the proteins. The intrinsic MSD is independent of the simulation time and defined as the infinite time value of calculated MSD that appears in the Debye-Waller factor. The method consists of fitting a model to the incoherent intermediate scattering function. The model contains the intrinsic MSD and a rate constant characterizing the motions of H in the protein. The method is illustrated by obtaining the intrinsic MSD of lysozyme in 100 ns and 1 ?s MD simulations.

Vural, Derya; Glyde, Henry R.; Hong, Liang

2013-03-01

101

Internal Displacement Monitoring Centre  

Science.gov (United States)

The Internal Displacement Monitoring Centre (IDMC) was established twelve years ago in the hope that they would "raise awareness of the plight of internally displaced people (IDP), point to gaps in national and international responses and promote solutions reflecting international standards and best practices." The Centre also keeps a database of 50 countries in which people have been displaced within their own country due to conflicts or human rights violations. To get a sense of where displaced persons are and how many countries have IDPs, visitors can click on the small world map on the far right hand side of the homepage. Scrolling over the map will reveal the number of displaced people by continent. Visitors interested in learning about an individual country can click on the continent, then click on one of the countries for an "Internal Displacement Profile", "Country Statistics", and an "Overview". The Resources tab, at the top of any page, includes "IDMC Publications", "Picture Galleries" of internally displaced people in India, Cyprus, and the West Bank, to name a few, and "IDP Maps" which has dozens of maps of from 2001 to 2009.

102

Characterization of silica-functionalized carbon nanotubes dispersed in water  

International Nuclear Information System (INIS)

Carbon nanotubes (CNTs) have the potential to enhance the strength, toughness, and multifunctional ability of composite materials. However, suitable dispersion and interfacial bonding remain as key challenges. Composites that are formed by reactions with water, like Portland cement concrete and mortar, pose a special challenge for dispersing the inherently hydrophobic nanotubes. The hydration of Portland cement also offers a specific chemical framework for interfacial bonding. In this study, nanoscale silica functional groups are covalently bonded to CNTs to improve their dispersion in water while providing interfacial bond sites for the proposed matrix material. The bond signatures of treated nanotubes are characterized using Fourier transform infrared spectroscopy. In situ dispersion is characterized using cryogenic transmission electron microscopy and point of zero charge (PZC) measurements. At the nanoscale, interparticle spacing was greatly increased. A slight increase in the PZC after treatment indicates the importance of steric effects in the dispersion mechanism. Overall, results indicate successful functionalization and dramatically improved dispersion stability in water.

103

Characterization of silica-functionalized carbon nanotubes dispersed in water  

Energy Technology Data Exchange (ETDEWEB)

Carbon nanotubes (CNTs) have the potential to enhance the strength, toughness, and multifunctional ability of composite materials. However, suitable dispersion and interfacial bonding remain as key challenges. Composites that are formed by reactions with water, like Portland cement concrete and mortar, pose a special challenge for dispersing the inherently hydrophobic nanotubes. The hydration of Portland cement also offers a specific chemical framework for interfacial bonding. In this study, nanoscale silica functional groups are covalently bonded to CNTs to improve their dispersion in water while providing interfacial bond sites for the proposed matrix material. The bond signatures of treated nanotubes are characterized using Fourier transform infrared spectroscopy. In situ dispersion is characterized using cryogenic transmission electron microscopy and point of zero charge (PZC) measurements. At the nanoscale, interparticle spacing was greatly increased. A slight increase in the PZC after treatment indicates the importance of steric effects in the dispersion mechanism. Overall, results indicate successful functionalization and dramatically improved dispersion stability in water.

Stynoski, Peter, E-mail: pstynos2@illinois.edu; Mondal, Paramita, E-mail: pmondal@illinois.edu [University of Illinois at Urbana-Champaign, Department of Civil and Environmental Engineering (United States); Wotring, Erik, E-mail: erik.wotring@usace.army.mil; Marsh, Charles, E-mail: charles.p.marsh@usace.army.mil [US Army Construction Engineering Research Laboratory (United States)

2013-01-15

104

Effects of bridge functions on radial distribution functions of liquid water.  

Science.gov (United States)

In this report the radial distribution functions (RDFs) of liquid water are calculated on the basis of the classical density functional theory combined with the reference interaction site model for molecular liquids. The bridge functions, which are neglected in the hypernetted-chain (HNC) approximation, are taken into account through the density expansion for the Helmholtz free energy functional up to the third order. A factorization approximation to the ternary direct correlation functions in terms of the site-site pair correlation functions is then employed in the expression of the bridge functions, thus leading to a closed set of integral equations for the determination of the RDFs. It is confirmed through numerical calculations that incorporation of the oxygen-oxygen bridge function substantially improves the poor descriptions by the HNC approximation at room temperature, e.g., for the second peak of the oxygen-oxygen RDF. PMID:25118654

Tanaka, Shigenori; Nakano, Miki

2014-08-14

105

Effects of Bridge Functions on Radial Distribution Functions of Liquid Water  

CERN Document Server

In this report the radial distribution functions (RDFs) of liquid water are calculated on the basis of the classical density functional theory combined with the reference interaction site model for molecular liquids. The bridge functions, which are neglected in the hypernetted-chain (HNC) approximation, are taken into account through the density expansion for the Helmholtz free energy functional up to the third order. A factorization approximation to the ternary direct correlation functions in terms of the site-site pair correlation functions is then employed in the expression of the bridge functions, thus leading to a closed set of integral equations for the determination of the RDFs. It is confirmed through numerical calculations that incorporation of the oxygen-oxygen bridge function substantially improves the poor descriptions by the HNC approximation at room temperature, e.g., for the second peak of the oxygen-oxygen RDF.

Tanaka, Shigenori

2014-01-01

106

Function and biotechnology of extremophilic enzymes in low water activity  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Enzymes from extremophilic microorganisms usually catalyze chemical reactions in non-standard conditions. Such conditions promote aggregation, precipitation, and denaturation, reducing the activity of most non-extremophilic enzymes, frequently due to the absence of sufficient hydration. Some extremophilic enzymes maintain a tight hydration shell and remain active in solution even when liquid water is limiting, e.g. in the presence of high ionic concentrations, or at cold temperature when water is close to the freezing point. Extremophilic enzymes are able to compete for hydration via alterations especially to their surface through greater surface charges and increased molecular motion. These properties have enabled some extremophilic enzymes to function in the presence of non-aqueous organic solvents, with potential for design of useful catalysts. In this review, we summarize the current state of knowledge of extremophilic enzymes functioning in high salinity and cold temperatures, focusing on their strategy for function at low water activity. We discuss how the understanding of extremophilic enzyme function is leading to the design of a new generation of enzyme catalysts and their applications to biotechnology.

Karan Ram

2012-02-01

107

Function of Serum Complement in Drinking Water Arsenic Toxicity  

OpenAIRE

Serum complement function was evaluated in 125 affected subjects suffering from drinking water arsenic toxicity. Their mean duration of exposure was 7.4 ± 5.3?yrs, and the levels of arsenic in drinking water and urine samples were 216 ± 211 and 223 ± 302??g/L, respectively. The mean bactericidal activity of complement from the arsenic patients was 92% and that in the unexposed controls was 99% (P < 0.01), but heat-inactivated serum showed slightly elevated activity than in controls. I...

Islam, Laila N.; Shamim Hasan Zahid, M.; Nurun Nabi, A. H. M.; Mahmud Hossain

2012-01-01

108

Soil water diffusivity as a function of water content and time  

International Nuclear Information System (INIS)

The soil-water diffusivity has been studied as a function of water content and time. From the idea of studying the horizontal movement of water in swelling soils, a simple formulation has been achieved which allows for the diffusivity, water content dependency and time dependency, to be estimated, not only of this kind of soil, but for any other soil as well. It was observed that the internal rearrangement of soil particles is a more important phenomenon than swelling, being responsible for time dependency. The method 2? is utilized, which makes it possible to simultaneously determine the water content and density, point by point, in a soil column. The diffusivity data thus obtained are compared to those obtained when time dependency is not considered. Finally, a new soil parameter, ?, is introduced and the values obtained agrees with the internal rearrangment assumption and time dependency for diffusivity (Author)

109

Functional brain studies with O-15 water and PET  

International Nuclear Information System (INIS)

Positron emission tomography (PET) with intravenous injection of O-15 water allows regional cerebral blood flow (rCBF) images to be obtained repeatedly within a short period of time. Since increased electrical activity in a specific brain region is followed by an abrupt increase in rCBF, the technique with O-15 water and PET is suitable for functional stimulation-activation studies. In general, the images are analyzed by making a subtraction image (activation minus baseline) and then identifying the activated areas on anatomical structures. This approach is widely applicable, ranging from simple stimulation to highly integrated tasks. The detectability and amplitude of the responsive area depend on the PET system and methodology. In this article, we mainly describe the methodological aspects of activaiton analysis and review some of PET data for exploring higher cognitive functions. (author) 43 refs

110

Regulation of Isotopic Composition of Water - way of Improvement of Cosmonauts Drinking Water Functional Properties  

Science.gov (United States)

The problem in providing drinking water to cosmonauts is solved - at this moment there is a task to improve the functional properties of the water. One of the perspectives of this trend is the use of light isotopic water. The animal studies have shown that long-term consumption of water with a depletion of deuterium and oxygen heavy isotopes accelerates the rise of mass non-irradiated mice, the phase fluctuations reducing or increasing hematological parameters were having adaptive nature. These fluctuations didn’t overcome values beyond the physiological norm of this type of animal. It is established that the therapeutic use of light isotopic water with 35 - 90 ppm in deuterium increases the survival of irradiated mice by an average of 30%, contributes to the preservation of irradiated animals body weight. Treatment of acute radiation sickness with light isotopic water stimulates hematopoietic recovery. At the same time, keeping mice drinking light isotopic water for 7 - 8 days before the irradiation (from 4 to 8.5 Gr) has no effect on the level of radio resistance. Longer keeping mice on light isotopic water, for 14 -21 days - reduction in life expectancy, animal mass, bone marrow cellularity and the level of white blood cells in irradiated animals is noted. It was established that keeping mice on light isotopic water for 14 days before exposure in experimental animals causes an increase in the mitotic index and the frequency of formation of aberrant mitosis after 24 hours of Co(60) gamma radiation in doses of 1 , 2, and 4 Gr. Thus, it is clear that the regulation of the isotopic composition of drinking water - way to improve its functional properties.

Kulikova, Ekaterina; Utina, Dina; Vorozhtsova, Svetlana; Severyuhin, Yuri; Abrosimova, Anna; Sinyak, Yuri; Ivanov, Alexander

111

Study of Xe poisoning effect on fuel displacement strategies in a nuclear electric plant equipped with a natural uranium - heavy water reactor  

International Nuclear Information System (INIS)

The effect of Xenon poisoning on fuel handling strategies in a natural uranium reactor was studied. A computer code, called PRODFIS was devised to have a permanent control on the concentrations of fission products, allowing to obtain the concentration values for a fission product, at any moment. This computer code can simultaneously follow 19 fission products and supply information at different time intervals depending on the computer storage used. The problems concerning the behaviour of Xe and Sm concentrations in the reactor and their influence on its functioning were mathematically treated. The influence of Xe concentration oscillations on the functioning of a natural uranium-heavy water reactor was analysed by means of a computer code called OSCXEN that allowed us to obtain the radial and axial values for fast and thermal neutron flows at certain time intervals and iodine and Xenon concentration values on different time ranges. Dynamic programming methods were applied to the study of the control of Xe and Sm poisoning, obtaining the solutions for two aspects of this problem, namely the minimization of the Xe concentration value and Xe concentration maximum. This problem is solved by using a control system of ''bang-bang'' type. A computer code called XENPROG was devised to determine the best version for the neutron flow when the reactor is stopped in such a way as the two conditions imposed by Xe concentration minimization or minimization of Xe concentration maximum to be fulfilled. Ex.perimental measurements were performed on the V/V. R-S reactor in order to verify the results obtained with XENPROG channel. Agreement between experimental results, applying XENPROG code indications, and results obtained bY means of calculation confirms the correctness of the computer code. (author)

112

Uranium enrichment by displacement chromatography  

International Nuclear Information System (INIS)

Natural Uranium contains 0.72% of fissile isotope 235U. Need for 235U enriched uranium for light water moderated reactors and other uses are well known. Uranium enrichment is a highly complex and tedious process owing to extremely small separation factor. Several processes have been tried; however, gaseous diffusion and centrifugation techniques based on mass dependent isotope effect are being exploited for producing enriched uranium. In the recent past, Isotope fractionation based on mass independent isotope effect such as LASER technique, ion exchange displacement chromatography etc. have drawn the attention of separation scientist and efforts are being made for development and industrial deployment of these technologies. Indian Nuclear Power Programme is based on use of natural uranium (PHWRs) and slightly enriched uranium (BWRs, PWRs) with emphasis on use of vast resources of thorium. Spent fuel from PHWRs, which is depleted in 235U (0.2 to 0.3%), appears to be a promising source of slightly enriched uranium (1 to 3% 235U). Harnessing this source for 235U enrichment would augment fuel supply for PHWR and light water reactors. Ion exchange displacement chromatography is a proliferation resistant novel technique for 235U enrichment. It is based on nuclear field shift - an isotope shift in orbital electrons resulting from the isotopic difference in nuclear size and shape. Due to this effect lighter isotope (235U) exhibits a stronger tendency for a higher valence i.e. UO22+ as compared to heavier isotope (238U). Preliminary laboratory study is being carried out at HWP, Manuguru for exploring feasibility of using ion exchange displacement chromatography for enriching 235U using 4-vinyl pyridine based anion exchange resin

113

Performance of an agricultural tractor in no tillage as a function of displacement speed and the seeders' tire inflation pressure  

Energy Technology Data Exchange (ETDEWEB)

The performance of an agricultural tractor under field conditions results from the tire wheel interaction together with its displacement speed. This work was developed to assess the performance of an agricultural tractor under the (75, 70, and 60 psi) tire inflation pressure conditions of a seeder and in two different gears providing speeds of 3.0 and 6.0 km h{sup -1}. The experiment took place at Sao Paulo State University (UNESP), at the Jaboticabal Campus, and was conducted by Laboratory of Machines and Agricultural Mechanization (LAMMA) at the Department of Rural Engineering. The delineation used was entirely randomized in a 2-factor factorial scheme (3 x 2) with 4 repetitions. We also observed that fuel consumption was influenced only by the tractor gear. Energy consumption was greater as speed increased, caused by gear shifting. The displacement speed was greater for the 75-psi pressure due to a lesser slippage in the seeder when under this pressure. Tractor slippage and initial stand did not change with the tested factors. (author)

Furlani, Carlos Eduardo Angeli; Cortez, Jorge Wilson; Silva, Rouverson Pereira da; Grotta, Danilo Cesar Checchio; Toledo, Anderson de [Universidade Estadual Paulista (UNESP), Jaboticabal, SP (Brazil)], E-mail: furlani@fcav.unesp.br

2008-07-01

114

Experimental determinations of correction factors as a function of vertical displacement of radioactive sources in the radionuclide calibrators of the CRCN-NE, Pernambuco, Brazil  

Energy Technology Data Exchange (ETDEWEB)

In nuclear medicine, the accurate knowledge of the activity of radio-pharmaceuticals which will be administered to the patients is an important factor to ensure the success of diagnosis or therapy. The activity measurements are performed in reentrant ionization chambers, also known as radionuclide calibrators. These equipment are sensitive to changes in radioactive sample geometry and its position within the chamber well. The purpose this work was to evaluate the behavior of radionuclide calibrators by means of vertical displacement of radioactive sources in the well and to determine experimentally the correction factors for each radionuclide, recognizing the specific positions in which the measurements must be made to ensure the highest sensitivity. The highest activity was obtained between 6 and 8 cm from the bottom of the well for both radionuclide calibrators utilized at this work. (author)

Fragoso, Maria da Conceiao de Farias; Albuquerque, Antonio Morais de Sa; Lacerda, Isabelle Viviane Batista de; Oliveira, Mercia L. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, MG (Brazil)

2011-07-01

115

Experimental determinations of correction factors as a function of vertical displacement of radioactive sources in the radionuclide calibrators of the CRCN-NE, Pernambuco, Brazil  

International Nuclear Information System (INIS)

In nuclear medicine, the accurate knowledge of the activity of radio-pharmaceuticals which will be administered to the patients is an important factor to ensure the success of diagnosis or therapy. The activity measurements are performed in reentrant ionization chambers, also known as radionuclide calibrators. These equipment are sensitive to changes in radioactive sample geometry and its position within the chamber well. The purpose this work was to evaluate the behavior of radionuclide calibrators by means of vertical displacement of radioactive sources in the well and to determine experimentally the correction factors for each radionuclide, recognizing the specific positions in which the measurements must be made to ensure the highest sensitivity. The highest activity was obtained between 6 and 8 cm from the bottom of the well for both radionuclide calibrators utilized at this work. (author)

116

Measurement of interfacial displacement of a liquid film in microchannels using laser focus displacement meter  

International Nuclear Information System (INIS)

This paper presents a new method for measuring the interfacial displacement of a liquid film in microchannels using a laser focus displacement meter (LFD). The purpose of the study is to clarify the effectiveness of the new method for obtaining detailed information concerning interfacial displacement, especially in the case of a thin liquid film, in micro- and mini-channels. To prevent the tube wall signal from disturbing that of the gas-liquid interface, a fluorocarbon tube with water box was used; the refraction index of this device is same as that for water. With this method, accurate instantaneous measurements of interfacial displacement of the liquid film were achieved. The error caused by refraction of the laser beam passing through the acrylic water box and fluorocarbon tube was estimated analytically and experimentally. The formulated analytical equation can estimate the real interface displacement using measured displacement in a fluorocarbon tube of 25 ?m to 2.0 mm I.D. A preliminary test using fluorocarbon tubes of 1 and 2 mm I.D. showed that the corrected interface displacement calculated by the equation agreed with real displacement within a 1% margin of error. It was also confirmed that the LFD in the system could measure a liquid film of 0.25 ?m at the thinnest. We made simultaneous measurements of the interface in fluorocarbon tubes of 0.5 and 1 mm I.D. using the LFD and a high-speed video camera with a microscope. These showed that the LFD could meaope. These showed that the LFD could measure the interface of a liquid film with high spatial and temporal resolution during annular, slug, and piston flow regimes. The data also clarified the existence of a thin liquid film less than 1 ?m in thickness in slug and annular flow regions. (author)

117

Displacement and Velocity Ratios  

Science.gov (United States)

This interactive presentation, created by James Bourassa and John Rosz for the Electromechanical Digital Library, discusses displacement and velocity ratios. Bourassa and Rosz begin by providing detailed definitions of both topics and then provide mathematical examples of each. Once this basic explanation is complete, the authors allow students to practice these theories in a set of self-correcting quiz questions. Bourassa and Rosz explain each using helpful interactive flash animations. These are not only useful in explanation, but they allow the student to more fully engage with the topic. Overall, this is a nice introduction to the physical and mathematical concepts of displacement and velocity ratios. This could be a valuable learning resource in everything from a physics to a technical education classroom.

Bourassa, James

118

Shore line displacement in Oeregrundsgrepen  

International Nuclear Information System (INIS)

This report is a part of the SKB project 'SAFE' (Safety Assessment of the Final Repository of Radioactive Operational Waste). The aim of project SAFE is to update the previous safety analysis of SFR-1. The analysis is to be presented to the Swedish authorities not later than the end of 2000. SFR-1 is a facility for disposal of low and intermediate level radioactive waste and is situated in bedrock beneath the Baltic Sea, 1 km off the coast near the Forsmark nuclear power plant in Northern Uppland. The shore displacement in the Oeregrundsgrepen area is at present approximately 60 cm per 100 years and is slowly decreasing, but will still be substantial for many thousands of years. Since Oeregrundsgrepen is a relatively shallow part of the Bothnian Sea, the positive shore displacement will greatly effect the proportions of land and sea in the future. Within 2000 years (4000 AD) half of the current water area in Oeregrundsgrepen will be land and the water volume will be decreased with two thirds. At 7000 AD, the whole Oeregrundsgrepen area will be without brackish water. The effects on the landscape evolution due to shore displacement in the Oeregrundsgrepen area are illustrated in a chronological series of digital maps in Power Point format available saved on the supplied CD-rom and entitled 'Elevation.ppt '. The bedrock tectonics in the area are in two dominating directions: one northern that can be seen in the west shoreline of the island Graesoe and one in a north-westerly direction seen in the shoreline of the mainland. Many of the large basins that will be established in the area due to the shore displacement will be elongated in one of these directions. Some of the basins are relatively shallow and therefore probably will be totally filled with organic rich sediments and will form peat or bogs. Other basins, especially Graesoeraennan (the deep channel on the west side of Graesoe) are deep basins and will form a long chain of deep lakes. One of the deeper basins will be formed close to the SFR-1. The catchment to this former lake constitutes the inner model area that is studied in more detail. The landscape evolution in this area is also illustrated as a time series of digital maps in Power Point format 'Elevinre.ppt'. The sea bottom directly above SFR-1 will start to drain approximately 2400 AD and will be completely dry approximately 3500 AD. The inner model area will be without brackish water approximately 5000 AD and at least 20 new basins (>10000 m2 )will be formed within this area. Most of them will be shallow basins and will therefore quickly be transformed into peat or bogs. When the inner model area is drained of brackish water approximately 75% of the area will be bedrock or wave washed till and 25% peat, bog or lake

119

Transient Response Functions for Conjunctive Water Management in the Snake River Plain, Idaho  

Science.gov (United States)

Increasing demands on western water are causing a mounting need for the conjunctive management of surface water and ground water resources. Under western water law, the senior water rights holder has priority over the junior water rights holder in times of water shortage. Water managers have been reluctant to conjunctively manage surface water and ground water resources because of the difficulty of quantification of the impacts to surface water resources from ground water stresses. Impacts from ground water use can take years to propagate through an aquifer system. Prediction of the degree of impact to surface water resources over time and the spatial distribution of impacts is very difficult. Response functions mathematically describe the relationship between a unit ground water stress applied at a specific location and stream depletion or aquifer water level change elsewhere in the system. Response functions can be used to help quantify the spatial and temporal impacts to surface water resources caused by ground water pumping. This paper describes the theory of response functions and presents an application of transient response functions in the Snake River Plain, Idaho. Transient response functions can be used to facilitate the conjunctive management of surface and ground water not only in the eastern Snake River Plain basin, but also in similar basins throughout the western United States.

Cosgrove, Donna M.; Johnson, Gary S.

2004-12-01

120

Exercising divers' thermal protection as a function of water temperature.  

Science.gov (United States)

Physiological adjustments and passive thermal insulation are not sufficient to protect divers in the cold and warm waters experienced by sport, professional and military divers. In a previous study of resting subjects, divers were protected by actively heated/cooled water that perfused a six-zone (head, torso, arms, hands, legs and feet) tube suit. Subsequently a self-contained diver thermal protection system (DTPS) was developed and used in this study to test male divers (n = 8) wearing a 6-mm foam neoprene wetsuit in water temperatures (T(W)) of 10 degrees C-39 degrees C at 4 feet in depth. The DTPS is a scuba backpack containing five thermoelectric devices that heat/cool water to 30 degrees C, six pumps that circulate the water through a six-zone tube suit via two manifolds, and an electronic controller. Skin temperatures (T(S), n = 17) and core temperature (T(C), capsule) were measured. The DTPS and each zone of the tube suit were also instrumented. Divers were tested with the DTPS operational (protected) and turned off (unprotected) for 90 minutes. In the unprotected condition, T(S) decreased and approached T(W), while T(C) trended to decrease over the exposure time. Mean T(S) as a function of T(W) was T(S) = 0.44 T(W) + 21.23 degrees C while unprotected, but T(S) = 0.19 T(W) + 27.1 degrees C when the diver was protected. The average total heating/cooling power required to protect the diver was 166 +/- 78W, 86 +/- 95W, 9 +/- 75W, 72 +/- 45W, 135 +/- 73W, 279 +/- 87W and 336 +/- 95W at 10, 15, 20, 25, 30, 35 and 39 degrees C water temperatures, respectively. This power requirement was nominally split 4%, 22%, 22%, 14%, 25% and 13% for head, torso, arms, hands, legs and feet, respectively. While unprotected, divers T(S) and T(C) did not remain within acceptable limits in T(W) below 25 degrees C or above 30 degrees C. When using the DTPS, however, they did remain within acceptable limits, and the divers reported they were comfortable. PMID:21510272

Pendergast, David R; Mollendorf, Joseph

2011-01-01

121

Virtual Displacement in Lagrangian Dynamics  

OpenAIRE

The confusion and ambiguity encountered by students, in understanding virtual displacement and virtual work, is addressed in this article. A definition of virtual displacement is presented that allows one to express them explicitly for both time independent and time dependent constraints. It is observed that for time independent constraints the virtual displacements are the displacements allowed by the constraints. However this is not so for a general time dependent case. Fo...

Ray, Subhankar; Shamanna, J.

2004-01-01

122

Effects of Buoyancy Forces on Immiscible Water/Oil Displacements in a Vertically Oriented Porous Medium Effets des facteurs de flottabilité sur les déplacements non-miscibles eau/huile dans un milieu poreux vertical  

Directory of Open Access Journals (Sweden)

Full Text Available The effects of buoyancy forces on liquid-liquid displacement processes occurring in porous media are important in a variety of practical situations, in particular during the displacement of oil from partially-depleted underground reservoirs by means of aqueous solutions. Most previous studies involving the visualization of water/oil displacements in porous media have been undertaken in horizontal two-dimensional porous medium cells. The objective of the present work was to determine the effects of buoyancy forces; on the fingering pattern and oil recovery by conducting immiscible displacement experiments in two-dimensional consolidated porous medium cells aligned in the vertical plane. In order to obtain a clear understanding of the favourable and unfavourable effects of buoyancy forces, experiments were carried out in three different flow modes, namely horizontal, vertical upward, and vertical downward. As the effects of buoyancy forces are negligible for two-dimensional porous media in the horizontal flow mode, the recoveries obtained in this mode were used as a reference for comparison with those obtained in the two vertical modes. Displacements using five different density ratios were studied. The breakthrough time and percentage oil recovery were measured in each case. The effects of buoyancy forces, viscous forces, and capillary forces, as well as the injection flow rate, were also recorded. The results obtained indicate that the effects of buoyancy forces are very pronounced at low flow rates and low oil/water density ratios, and that even a slight increase in the flow rate causes the buoyancy forces to rapidly become less significant. Les facteurs de flottabilité exercent un effet important sur les déplacements liquide/liquide en milieu poreux dans toute une gamme de situations pratiques, en particulier lorsqu'on veut déplacer l'huile de roches réservoirs partiellement épuisées à l'aide de solutions aqueuses. La plupart des études effectuées jusqu'ici ont fait intervenir la visualisation des déplacements eau/huile en deux dimensions, dans des milieux poreux horizontaux. L'objectif de la présente recherche est de déterminer les effets des facteurs de flottabilité sur le phénomène de digitation et la récupération de l'huile, en effectuant des expériences de déplacements non-miscibles sur des milieux poreux consolidés, bi-dimensionnels, à cellules alignées dans un plan vertical. Pour bien comprendre les effets positifs et négatifs des facteurs de flottabilité, nous avons effectué des expériences avec trois modes d'écoulement différents : horizontal, vertical ascendant et vertical descendant. L'effet des facteurs de flottabilité étant négligeable pour les milieux poreux bi-dimensionnels en cas d'écoulement horizontal, les données de récupération obtenues dans ce cas ont servi de référence pour comparaison avec les données obtenues en cas d'écoulement vertical. L'étude des déplacements a été effectuée avec cinq solutions de densité différente. Dans chaque cas, nous avons mesuré le temps de percée et le pourcentage de récupération de pétrole. Les effets des facteurs de flottabilité, de capillarité et de viscosité ont été enregistrés, ainsi que le débit d'injection. Les résultats obtenus indiquent que les facteurs de flottabilité exercent un effet très prononcé à faible débit et pour une faible densité huile/eau, et que la moindre augmentation du débit entraîne une baisse rapide de cet effet.

Thirunavu S. R.

2006-11-01

123

Displacement Based Multilevel Structural Optimization  

Science.gov (United States)

In the complex environment of true multidisciplinary design optimization (MDO), efficiency is one of the most desirable attributes of any approach. In the present research, a new and highly efficient methodology for the MDO subset of structural optimization is proposed and detailed, i.e., for the weight minimization of a given structure under size, strength, and displacement constraints. Specifically, finite element based multilevel optimization of structures is performed. In the system level optimization, the design variables are the coefficients of assumed polynomially based global displacement functions, and the load unbalance resulting from the solution of the global stiffness equations is minimized. In the subsystems level optimizations, the weight of each element is minimized under the action of stress constraints, with the cross sectional dimensions as design variables. The approach is expected to prove very efficient since the design task is broken down into a large number of small and efficient subtasks, each with a small number of variables, which are amenable to parallel computing.

Sobieszezanski-Sobieski, J.; Striz, A. G.

1996-01-01

124

A displacement-doubling prism  

Energy Technology Data Exchange (ETDEWEB)

A novel prism has been devised which can be used in place of the ‘flag’ in an optical shadow-sensing type of displacement sensor, for example. In this way, theoretically the displacement sensitivity of the sensor can be doubled. Such a prism has been manufactured, and its displacement-doubling property has been verified. - Highlights: • A new type of glass prism doubles linear displacement of optical beams. • Optical operation has been verified. • Light beams enter and exit at normal incidence to prism's windows. • Optical path length through prism remains constant, as prism is moved. • Designed to double the displacement sensitivity of knife-edge shadow sensors.

Lockerbie, Nicholas A., E-mail: N.Lockerbie@strath.ac.uk [Department of Physics, SUPA (Scottish Universities Physics Alliance), University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow G4 0NG, Scotland (United Kingdom); Associate of the Institute for Gravitational Research, University of Glasgow, G12 8QQ, Scotland (United Kingdom)

2014-03-21

125

Understanding the Impact of Open-Framework Conglomerates on Water-Oil Displacements: Victor Interval of the Ivishak Reservoir, Prudhoe Bay Field, Alaska  

CERN Document Server

The Victor Unit of the Ivishak Formation in the Prudhoe Bay Oilfield is characterized by high net-to-gross fluvial sandstones and conglomerates. The highest permeability is found within sets of cross-strata of open-framework conglomerate (OFC). They are preserved within unit bar deposits and assemblages of unit bar deposits within compound (braid) bar deposits. They are thief zones limiting enhanced oil recovery. We incorporate recent research that has quantified important attributes of their sedimentary architecture within preserved deposits. We use high-resolution models to demonstrate the fundamental aspects of their control on oil production rate, water breakthrough time, and spatial and temporal distribution of residual oil saturation. We found that when the pressure gradient is oriented perpendicular to the paleoflow direction, the total oil production and the water breakthrough time are larger, and remaining oil saturation is smaller, than when it is oriented parallel to paleoflow. The pressure differe...

Gershenzon, Naum I; Ritzi, Robert W; Dominic, David F

2014-01-01

126

Catalytic molecular logic devices by DNAzyme displacement.  

Science.gov (United States)

Chemical reactions catalyzed by DNAzymes offer a route to programmable modification of biomolecules for therapeutic purposes. To this end, we have developed a new type of catalytic DNA-based logic gates in which DNAzyme catalysis is controlled via toehold-mediated strand displacement reactions. We refer to these as DNAzyme displacement gates. The use of toeholds to guide input binding provides a favorable pathway for input recognition, and the innate catalytic activity of DNAzymes allows amplification of nanomolar input concentrations. We demonstrate detection of arbitrary input sequences by rational introduction of mismatched bases into inhibitor strands. Furthermore, we illustrate the applicability of DNAzyme displacement to compute logic functions involving multiple logic gates. This work will enable sophisticated logical control of a range of biochemical modifications, with applications in pathogen detection and autonomous theranostics. PMID:24692254

Brown, Carl W; Lakin, Matthew R; Stefanovic, Darko; Graves, Steven W

2014-05-01

127

Diffusion of cations in homo-ionic swelling clays as a function of the water content  

International Nuclear Information System (INIS)

Document available in extended abstract form only. In the past years, dielectric spectroscopy has been recognized as a powerful tool for studying the dynamics of cations in aluminosilicate compounds such as zeolites or clays minerals. In the case of nuclear waste storage, clays show remarkable properties for confinement: swelling capacity and cation retention. Indeed, exchangeable cations are more weakly linked to the adjacent atoms than framework ions and thus are more mobile. They consequently contribute to the whole dielectric signal, assuming that the network can be considered as rigid. Furthermore, polar molecules, such as water, that strongly interact with the cations or/and with the structural aluminosilicate network, have relatively large dielectric effects. It is thus possible to investigate adsorption process with dielectric spectroscopy. Besides, in the case of clays their swelling capacity complicates the interpretation of results and modifies the activation energy for cation diffusion. The present work reports conductivity data, by means of Complex Impedance Spectroscopy (CIS), recorded on clays samples: homo-ionic montmorillonites (i.e. saturated by alkaline or alkaline-earth cations) and mixed Na-Ca montmorillonite. Purified MX-80 bentonite is considered in our study as a model for montmorillonite. The dynamics of exchangeable cations, in terms of the activation energy ?E required for the charge carrier displacement, is discussed as a function of: i) tment, is discussed as a function of: i) the nature of the clays, ii) the nature of the exchangeable cations (Li+, Na+, K+, Cs+ and Ca2+) and iii) the hydration state. In the latter, CIS results are interpreted in the light of the data recorded from Sample Controlled Thermal Analysis (SCTA). It is thus shown that the comparison between ?E obtained on dry solids and ?E determined on water saturated systems is an efficient way to estimate the hydration energy and the swelling process. The values are compared with theoretical hydration energy values based on electrostatic calculations. It follows that the agreement and the differences obtained between the two approaches allows us to distinguish different behaviors as a function of the nature of the interlayer cations. Another powerful result is the estimation of the diffusion coefficients of the interlayer cations. Conductivity measurements as a function of the relative humidity are combined with a recent approach used to determine the specific surface area. It is then possible to extract cations diffusion coefficients as a function of the relative humidity. The evolution of these diffusion coefficients clearly shows the influence of the hydration state of the cations as well as the opening of the interlayer space. It results that for some cations (Li+ and Na+), diffusion coefficients can reach very high values at high relative humidity, while for larger cations (Cs+ in particular), the diffusion coefficients stay at a very low value. These results are in agreement with the classical description of hydration in swelling clays where the smaller cations can hydrate with a complete water layer, in contrast with the larger cations which are strongly bonded to the clay layer, even at high hydration states. (authors)

128

Computer Simulation of Displacement Damage in Silicon Carbide  

International Nuclear Information System (INIS)

We have performed molecular dynamics simulation of displacement events on silicon and carbon sublattices in silicon carbide for displacement doses ranging from 0.005 to 0.5 displacements per atom. Our results indicate that the displacement threshold energy is about 21 eV for C and 35 eV for Si, and amorphization can occur by accumulation of displacement damage regardless of whether Si or C is displaced. In addition, we have simulated defect production in high-energy cascades as a function of the primary knock-on atom energy and observed features that are different from the case of damage accumulation in Si. These systematic studies shed light on the phenomenon of non-ionizing energy loss that is relevant to understanding space radiation effects in semiconductor devices

129

Displacement Parameter Inversion for a Novel Electromagnetic Underground Displacement Sensor  

OpenAIRE

Underground displacement monitoring is an effective method to explore deep into rock and soil masses for execution of subsurface displacement measurements. It is not only an important means of geological hazards prediction and forecasting, but also a forefront, hot and sophisticated subject in current geological disaster monitoring. In previous research, the authors had designed a novel electromagnetic underground horizontal displacement sensor (called the H-type sensor) by combining basic el...

Nanying Shentu; Qing Li; Xiong Li; Renyuan Tong; Nankai Shentu; Guoqing Jiang; Guohua Qiu

2014-01-01

130

Fluorescent organic nanoparticles of dihydropyrimidone derivatives for selective recognition of iodide using a displacement assay: application of the sensors in water and biological fluids.  

Science.gov (United States)

Fluorescent organic nanoparticles (FON's) derived from dihydropyrimidone derivatives (1-4) were developed and evaluated for their sensor properties. Nano-aggregates of compound 3 and 4 resulted in sensors. Nano-aggregates of compound 3 showed enhancement in the monomer peaks of the pyrene moiety after the addition of mercury. Nano-aggregates of compound 4 resulted in quenching of intensity upon addition of Hg(2+). On the other hand, no sensor activity was recorded for nano-aggregates of compounds 1 and 2. Further, the complex of nano-aggregates of 3 and mercury (3·Hg(2+)) recognised iodide ions by showing quenching in monomer and excimer emission with a detection limit of 0.2 nM in aqueous medium; however the resultant metal complex 4·Hg(2+) does not show any anion sensing activity. Receptor 3·Hg(2+) has a highly sensitive and selective response toward I(-) ions. Therefore, the iodide content of tap water, urine and blood serum is monitored using this sensor and it is found that the sensor can detect a range of iodide in tap water, urine and blood serum. To the best of our knowledge, the system represents the first example of iodide recognition using FONs. PMID:25428514

Kaur, Amanpreet; Raj, Tilak; Kaur, Simanpreet; Singh, Narinder; Kaur, Navneet

2015-01-28

131

Displacement Parameter Inversion for a Novel Electromagnetic Underground Displacement Sensor  

Directory of Open Access Journals (Sweden)

Full Text Available Underground displacement monitoring is an effective method to explore deep into rock and soil masses for execution of subsurface displacement measurements. It is not only an important means of geological hazards prediction and forecasting, but also a forefront, hot and sophisticated subject in current geological disaster monitoring. In previous research, the authors had designed a novel electromagnetic underground horizontal displacement sensor (called the H-type sensor by combining basic electromagnetic induction principles with modern sensing techniques and established a mutual voltage measurement theoretical model called the Equation-based Equivalent Loop Approach (EELA. Based on that work, this paper presents an underground displacement inversion approach named “EELA forward modeling-approximate inversion method”. Combining the EELA forward simulation approach with the approximate optimization inversion theory, it can deduce the underground horizontal displacement through parameter inversion of the H-type sensor. Comprehensive and comparative studies have been conducted between the experimentally measured and theoretically inversed values of horizontal displacement under counterpart conditions. The results show when the measured horizontal displacements are in the 0–100 mm range, the horizontal displacement inversion discrepancy is generally tested to be less than 3 mm under varied tilt angles and initial axial distances conditions, which indicates that our proposed parameter inversion method can predict underground horizontal displacement measurements effectively and robustly for the H-type sensor and the technique is applicable for practical geo-engineering applications.

Nanying Shentu

2014-05-01

132

Feature displacement interpolation  

DEFF Research Database (Denmark)

Given a sparse set of feature matches, we want to compute an interpolated dense displacement map. The application may be stereo disparity computation, flow computation, or non-rigid medical registration. Also estimation of missing image data, may be phrased in this framework. Since the features often are very sparse, the interpolation model becomes crucial. We show that a maximum likelihood estimation based on the covariance properties (Kriging) show properties more expedient than methods such as Gaussian interpolation or Tikhonov regularizations, also including scale-selection. The computational complexities are identical. We apply the maximum likelihood interpolation to growth analysis of the mandibular bone. Here, the features used are the crest-lines of the object surface.

Nielsen, Mads; Andresen, Per RØnsholt

1998-01-01

133

Job displacement penalties in Japan  

OpenAIRE

The costs of job displacement are examined on a sample of Japanese workers successfully provided job placement services from 2000 to 2003, a period of economic stagnation and structural change in Japan. We find that displaced workers suffer a loss of approximately $1,100 for each additional year of age. Workers also incur a large penalty when they change industries after being displaced. The age-earnings loss relationship is consistent with the operation of a delayed compensation scheme in la...

Bognanno, Michael; Delgado, Lisa

2005-01-01

134

Comparação entre as medidas inferenciais de edema de membros inferiores utilizando o Leg-O-Meter e o deslocador de água / Comparison between inferential measurements of lower limb edema utilizing the Leg-O-Meter and water displacement  

Scientific Electronic Library Online (English)

Full Text Available INTRODUÇÃO: A quantificação precisa da severidade e extensão de edema periférico é necessária antes e após a intervenção fisioterapêutica para avaliar a eficiência do tratamento. O objetivo deste estudo foi comparar as medidas de volume em membros inferiores (MMII) obtidas com dois instrumentos o Le [...] g-O-Meter (LM) e o deslocador de água (DA) em um período de 2 semanas. Materiais e métodos: Trinta e uma mulheres portadoras de edema de MMII com idade entre 20 e 70 anos participaram deste estudo. O edema foi inicialmente avaliado pela perimetria (LM) dos MMII ao nível do tornozelo e pelo volume de água deslocada após imersão do membro (DA). Após 2 semanas as medidas foram repetidas sem que houvesse alteração na medicação ou na rotina diária. Resultado: O percentual de alteração de edema no membro inferior direito (MID) com o LM e com o DA foi 0,3±4,18% e 0,9±3,31% (p=0,21), respectivamente. Para o membro inferior esquerdo o percentual de alteração foi de 0,7±3,44% e 0,5±3,84% (p=0,29), com o LM e o DA, respectivamente. A magnitude da correlação entre as medidas obtidas com o LM e o DL foi alta e significativa, variando de r=0,73 a r=0,83 (p Abstract in english Background: Precise quantification of the severity and extent of edema is necessary before and after physiotherapeutic intervention, in order to evaluate the efficiency of the treatment. The objective of this study was to compare lower limb (LL) volume measurements from two methods: Leg-O-Meter (LM) [...] and water displacement (WD), over a two-week interval. Method: Thirty-one women with LL edema, aged between 20 and 70 years, participated in this study. Edema was initially evaluated by circumference measurement (LM) at the ankle level, and by means of the volume of water displaced upon immersion of the limb (WD). After 2 weeks, these measurements were repeated without there having been any change in daily routines or medication intake. Results: the percent changes in edema in the right lower limb (RLL) using LM and WD were 0.3±4.18% and 0.9±3.31% (p=0.21), respectively. For the left lower limb (LLL) the percent changes were 0.7±3.44% and 0.5±3.84% (p=0.29), utilizing LM and WD, respectively. The magnitude of the correlation between the measurements obtained via the two techniques was high and significant, ranging from r=0.73 to r=0.83 (p

ABC, Oliveira; CPO, Lara; SS, Lins; IT, Cunha-Filho.

135

CONCEPTUAL MODEL FOR ASSESSING ECOLOGICAL RISK TO WATER QUALITY FUNCTION OF BOTTOMLAND HARDWOOD FORESTS  

Science.gov (United States)

Ecological risk assessment provides a methodology for evaluating the threats of ecosystem function associated with environmental perturbations or stressors. his report documents the development of a conceptual model for assessing the ecological risk to the water quality function ...

136

Sorption and displacement of pyrene in soils and sediments.  

Science.gov (United States)

Sorption isotherms of pyrene on soils and sediments were examined to understand its sorption behavior. All systems examined exhibited nonlinear sorption. Sorption nonlinearity was found to be a function of the polarity index of soil/sediment organic matter (SOM), suggesting that the degree of condensation of SOM, characterized by its polarity index, was correlated with the sorption behavior of pyrene. The polarity index of SOM could be a new factor for explaining the sorption nonlinearity. The sorption affinity of two soils and two sediments for pyrene increased with decreasing SOM polarity. A higher sorption affinity in the two soils was associated with a higher degree of condensation of SOM compared to that of the two sediments. A displacement test was performed after pyrene sorption using phenanthrene as a displacer. Pyrene was displaced in all systems examined, and nonlinearity became less pronounced after displacement. Such an increase in isotherm linearity implied that sorption site energies became more homogeneous after displacement. Furthermore, the site energy distribution IE*) derived from the Freundlich model parameters showed that energy reduction of high-energy sites was more significant than that of low-energy sites after displacement. In addition, a decrease in sorption capacity after displacement could be ascribed to the partial depletion of sorption sites by the displacer. The displacement data indicated that the cocontaminant can have potential effects on the fate and bioavailability of anthropogenic organic pollutants sorbed in soils and sediments, thus affecting their exposure risks. PMID:16323767

Wang, Xilong; Sato, T; Xing, Baoshan

2005-11-15

137

ASF1 and the SWI/SNF complex interact functionally during nucleosome displacement, while FACT is required for nucleosome reassembly at yeast heat shock gene promoters during sustained stress.  

Science.gov (United States)

Histone chaperones are an integral part of the transcription regulatory machinery. We investigated the involvement of histone chaperones and their functional interactions with ATP-dependent chromatin remodeling complexes in the regulation of yeast heat shock genes. Strong functional interaction between the histone chaperone ASF1 and the ATP-dependent chromatin remodeling complex SWI/SNF is exhibited in synergistic diminishment of nucleosome displacement during heat shock in the ?ASF1/?SNF2 strain in comparison to individual ASF1 or SNF2 inactivation. A similar but less pronounced effect was observed for ISW1/ASF1 inactivation but not for ASF1/STH1 (RSC complex) combinatorial inactivation. The depletion of Spt16, which is a major subunit of the FACT histone chaperone complex, leads to a severe growth defect phenotype associated with unusual thermotolerance. The acquired thermotolerance in the Spt16-depleted strain is associated with a defect in the reassembly of nucleosomes at the promoters of heat shock genes during sustained heat stress, leading to increased recruitment of the transcriptional activator HSF and RNA polymerase II. The defect in nucleosome assembly associated with Spt16 depletion also leads to an increased tolerance to stress due to an increased concentration of NaCl. PMID:25416387

Erkina, Tamara Y; Erkine, Alexandre

2015-03-01

138

Displaced rotations of coherent states  

CERN Document Server

We propose an approach that enables to use it for construction of rotations of coherent states, in particular, it gives a possibility to construct Hadamard gate for the coherent states. Our approach is based on representation of arbitrary one-mode pure state in free-travelling fields, in particular superposition of coherent states (SCSs), in terms of displaced number states with arbitrary amplitude of displacement. Studied optical scheme is based on alternation of photon additions and displacement operators (in general case, photon additions and displacements are required) with seed coherent state to generate both even and odd displaced squeezed SCSs (DSSCSs) regardless of number of used photon additions. It is shown the studied optical scheme is sensitive to seed coherent state provided that other parameters are invariable. Output states approximate with high fidelity either even squeezed SCS or odd SCS shifted relative each other by some value. It enables to construct local rotation operator for coherent st...

Podoshvedov, Sergey A

2011-01-01

139

Electrolysis cell functions as water vapor dehumidifier and oxygen generator  

Science.gov (United States)

Water vapor is absorbed in hygroscopic electrolyte, and oxygen generated by absorbed water electrolysis at anode is added simultaneously to air stream. Cell applications include on-board aircraft oxygen systems, portable oxygen generators, oxygen concentration requirements, and commercial air conditioning and dehumidifying systems.

Clifford, J. E.

1971-01-01

140

Density Functional Theory Study of the Complexation of the Uranyl Dication with Anionic Phosphate Ligands with and without Water Molecules  

Energy Technology Data Exchange (ETDEWEB)

The structures, vibrational frequencies and energetics of anhydrous and hydrated complexes of UO2 2+ with the phosphate anions H2PO4 ?, HPO4 2?, and PO4 3? were predicted at the density functional theory (DFT) and MP2 molecular orbital theory levels as isolated gas phase species and in aqueous solution by using self-consistent reaction field (SCRF) calculations with different solvation models. The geometries and vibrational frequencies of the major binding modes for these complexes are compared to experiment where possible and good agreement is found. The uranyl moiety is nonlinear in many of the complexes, and the coordination number (CN) 5 in the equatorial plane is the predominant binding motif. The phosphates are found to bind in both monodentate and bidentate binding modes depending on the charge and the number of water molecules. The SCRF calculations were done with a variety of approaches, and different SCRF approaches were found to be optimal for different reaction types. The acidities of HxPO4 3?x in HxPO4 3?x(H2O)4, x = 0?3 complexes were calculated with different SCRF models and compared to experiment. Phosphate anions can displace water molecules from the first solvation shell at the uranyl exothermically. The addition of water molecules can cause the bonding of H2PO4 ? and HPO4 2? to change from bidentate to monodentate exothermically while maintaining CN 5. The addition of water can generate monodentate structures capable of cross-linking to other uranyl phosphates to form the types of structures found in the solid state. [UO2(HPO4)(H2O)3] is predicted to be a strong base in the gas phase and in aqueous solution. It is predicted to be a much weaker acid than H3PO4 in the gas phase and in solution.

Jackson, Virgil E.; Gutowski, Keith E.; Dixon, David A.

2013-09-12

141

Density functional theory study of the complexation of the uranyl dication with anionic phosphate ligands with and without water molecules.  

Science.gov (United States)

The structures, vibrational frequencies and energetics of anhydrous and hydrated complexes of UO2(2+) with the phosphate anions H2PO4(-), HPO4(2-), and PO4(3-) were predicted at the density functional theory (DFT) and MP2 molecular orbital theory levels as isolated gas phase species and in aqueous solution by using self-consistent reaction field (SCRF) calculations with different solvation models. The geometries and vibrational frequencies of the major binding modes for these complexes are compared to experiment where possible and good agreement is found. The uranyl moiety is nonlinear in many of the complexes, and the coordination number (CN) 5 in the equatorial plane is the predominant binding motif. The phosphates are found to bind in both monodentate and bidentate binding modes depending on the charge and the number of water molecules. The SCRF calculations were done with a variety of approaches, and different SCRF approaches were found to be optimal for different reaction types. The acidities of HxPO4(3-x) in HxPO4(3-x)(H2O)4, x = 0-3 complexes were calculated with different SCRF models and compared to experiment. Phosphate anions can displace water molecules from the first solvation shell at the uranyl exothermically. The addition of water molecules can cause the bonding of H2PO4(-) and HPO4(2-) to change from bidentate to monodentate exothermically while maintaining CN 5. The addition of water can generate monodentate structures capable of cross-linking to other uranyl phosphates to form the types of structures found in the solid state. [UO2(HPO4)(H2O)3] is predicted to be a strong base in the gas phase and in aqueous solution. It is predicted to be a much weaker acid than H3PO4 in the gas phase and in solution. PMID:23905705

Jackson, Virgil E; Gutowski, Keith E; Dixon, David A

2013-09-12

142

Ko Displacement Theory for Structural Shape Predictions  

Science.gov (United States)

The development of the Ko displacement theory for predictions of structure deformed shapes was motivated in 2003 by the Helios flying wing, which had a 247-ft (75-m) wing span with wingtip deflections reaching 40 ft (12 m). The Helios flying wing failed in midair in June 2003, creating the need to develop new technology to predict in-flight deformed shapes of unmanned aircraft wings for visual display before the ground-based pilots. Any types of strain sensors installed on a structure can only sense the surface strains, but are incapable to sense the overall deformed shapes of structures. After the invention of the Ko displacement theory, predictions of structure deformed shapes could be achieved by feeding the measured surface strains into the Ko displacement transfer functions for the calculations of out-of-plane deflections and cross sectional rotations at multiple locations for mapping out overall deformed shapes of the structures. The new Ko displacement theory combined with a strain-sensing system thus created a revolutionary new structure- shape-sensing technology.

Ko, William L.

2010-01-01

143

Computer simulation of displacement cascades in copper  

International Nuclear Information System (INIS)

More than 500 displacement cascades in copper have been generated with the computer simulation code MARLOWE over an energy range pertinent to both fission and fusion neutron spectra. Three-dimensional graphical depictions of selected cascades, as well as quantitative analysis of cascade shapes and sizes and defect densities, illustrate cascade behavior as a function of energy. With increasing energy, the transition from production of single compact damage regions to widely spaced multiple damage regions is clearly demonstrated

144

A relative permeability model to derive fractional-flow functions of water-alternating-gas and surfactant-alternating-gas foam core-floods  

Science.gov (United States)

Foam is used in enhanced oil recovery to improve the sweep efficiency by controlling the gas mobility. The surfactant-alternating-gas (SAG) foam process is used as an alternative to the water-alternating-gas (WAG) injection. In the WAG technique, the high mobility and the low density of the gas lead the gas to flow in channels through the high permeability zones of the reservoir and to rise to the top of the reservoir by gravity segregation. As a result, the sweep efficiency decreases and there will be more residual oil in the reservoir. The foam can trap the gas in liquid films and reduces the gas mobility. The fractional-flow method describes the physics of immiscible displacements in porous media. Finding the water fractional flow theoretically or experimentally as a function of the water saturation represents the heart of this method. The relative permeability function is the conventional way to derive the fractional-flow function. This study presents an improved relative permeability model to derive the fractional-flow functions for WAG and SAG foam core-floods. The SAG flow regimes are characterized into weak foam, strong foam without a shock front and strong foam with a shock front.

Idrees Al-Mossawy, Mohammed; Demiral, Birol; Raja, D. M. Anwar

2013-04-01

145

A relative permeability model to derive fractional-flow functions of water-alternating-gas and surfactant-alternating-gas foam core-floods  

International Nuclear Information System (INIS)

Foam is used in enhanced oil recovery to improve the sweep efficiency by controlling the gas mobility. The surfactant-alternating-gas (SAG) foam process is used as an alternative to the water-alternating-gas (WAG) injection. In the WAG technique, the high mobility and the low density of the gas lead the gas to flow in channels through the high permeability zones of the reservoir and to rise to the top of the reservoir by gravity segregation. As a result, the sweep efficiency decreases and there will be more residual oil in the reservoir. The foam can trap the gas in liquid films and reduces the gas mobility. The fractional-flow method describes the physics of immiscible displacements in porous media. Finding the water fractional flow theoretically or experimentally as a function of the water saturation represents the heart of this method. The relative permeability function is the conventional way to derive the fractional-flow function. This study presents an improved relative permeability model to derive the fractional-flow functions for WAG and SAG foam core-floods. The SAG flow regimes are characterized into weak foam, strong foam without a shock front and strong foam with a shock front. (paper)

146

Measurement of chest wall displacement based on terahertz wave  

Science.gov (United States)

Measurement of chest wall displacement is an important approach for measuring mechanics of chest wall, which has considerable significance for assessing respiratory system and diagnosing pulmonary diseases. However, existing optical methods for measuring chest wall displacement are inconvenient for some specific patients such as the female patients and the patients with bandaged chest. In this letter, we proposed a method for measuring chest wall displacement based on terahertz wave and established corresponding mathematic model and set up a terahertz measurement system. The main advantages of this method are that it can measure the chest wall displacement of the subjects without taking off clothes or arranging any markers. To validate this method and assess the performance of the terahertz system, in vitro, the displacement of a water module driven by a linear guide rail was measured by the terahertz system and compared with the actual displacement of the water module. The results showed that the waveforms measured with two methods have a good agreement, and the relative error is less than 5% and sufficiently good for measurement demands. In vivo, the synchronous experiment was performed on five human volunteers with the terahertz system and a respiratory belt transducer. The results demonstrate that this method has good performance and promising prospects for measuring chest wall displacement.

Li, Hui; Lv, Hao; Jiao, Teng; Lu, Guohua; Li, Sheng; Li, Zhao; Liu, Miao; Jing, Xijing; Wang, Jianqi

2015-02-01

147

Boron isotopic enrichment by displacement chromatography  

International Nuclear Information System (INIS)

10B enriched boron is used in applications requiring high volumetric neutron absorption (absorption cross section- 3837 barn for thermal and 1 barn for 1 MeV fast neutron). It is used in fast breeder reactor (as control rod material), in neutron counter, in Boron Neutron Capture Therapy etc. Owing to very small separation factor, boron isotopic enrichment is a complex process requiring large number of separation stages. Heavy Water Board has ventured in industrial scale production of 10B enriched boron using Exchange Distillation Process as well as Ion Displacement Chromatography Process. Ion Displacement Chromatography process is used in Boron Enrichment Plant at HWP, Manuguru. It is based on isotopic exchange between borate ions (B(OH)4-) on anion exchange resin and boric acid passing through resin. The isotopic exchange takes place due to difference in zero point energy of 10B and 11B

148

Is Fibular Fracture Displacement Consistent with Tibiotalar Displacement?  

OpenAIRE

We believed open reduction with internal fixation is required for supination-external rotation ankle fractures located at the level of the distal tibiofibular syndesmosis (Lauge-Hanssen SER II and Weber B) with 2 mm or more fibular fracture displacement. The rationale for surgery for these ankle fractures is based on the notion of elevated intraarticular contact pressures with lateral displacement. To diagnose these injuries, we presumed that in patients with a fibular fracture with at least...

Den Bekerom, Michel P. J.; Dijk, C. Niek

2009-01-01

149

OIL DISPLACEMENT IN MISCIBLE CONDITION  

Directory of Open Access Journals (Sweden)

Full Text Available After primary oil recovery in reservoirs remains about 70% of unexploited oil. To improve the recovery of the remaining reserves, injection of a fluid provide the extra energy in a mchunical form. Oil displacement can he achieved by gas injection of lean natural gas, mainly methane, carbon dioxide etc. Oil displacement can be in immiscible or miscible conditions. This paper deals with mechanism of miscible gas drive. On the basis of simulation of the oil displacement process by gas injection into oil field Žutica the character of process, i. c. a degree of miscibility or immiscibility between the injected fluid and reservoir oil was determined.

Ivanka Juttner

1997-12-01

150

Displacement Ventilation : theory and design  

DEFF Research Database (Denmark)

Displacement ventilation is an interesting new type of air distribution principle which should be considered in connection with design of comfort ventilation in both smal1 and large spaces. Research activities on displacement ventilation are large all over the world and new knowledge of design methods appears continuously. This book gives an easy introduction to the basis of displacement ventilation and the chapters are written in the order which is used in a design procedure. The main text is extended by five appendices which show some of the new research activities taking place at Aalborg University.

Nielsen, Peter Vilhelm

1993-01-01

151

Studies on astrocyte function : potential roles in brain water homeostasis and neuroprotection  

OpenAIRE

Astrocytes are essential in brain homeostasis and function, including maintenance of water and ion balance. Astrocytes express the water channel aquaporin 4 (AQP4), implicated in both physiological functions and injury processes associated with brain edema, a common consequence of brain diseases. As part of the tripartite synapse astrocytes are tightly coupled to normal brain function via neuron-astrocyte interactions and by providing metabolic support to neurons as well as con...

Song, Yutong

2012-01-01

152

Measuring Volume by Displacement of Water  

Science.gov (United States)

This nine minute video shows highlights of a fifth grade class measuring the volume of irregular objects. The students learn to read a graduated cylinder in milliliters before and after an object is submersed. Students make a volume estimate beforehand and are asked to explain the measuring process verbally and in writing. A teacher interview is included.

2013-01-01

153

Functional traits composition predict macrophytes community productivity along a water depth gradient in a freshwater lake  

OpenAIRE

Functional trait composition of plant communities has been proposed as a helpful key for understanding the mechanisms of biodiversity effects on ecosystem functioning. In this study, we applied a step-wise modeling procedure to test the relative effects of taxonomic diversity, functional identity, and functional diversity on macrophytes community productivity along water depth gradient. We sampled 42 plots and 1513 individual plants and measured 16 functional traits and abundance of 17 macrop...

Fu, Hui; Zhong, Jiayou; Yuan, Guixiang; Ni, Leyi; Xie, Ping; Cao, Te

2014-01-01

154

Nucleophilic displacement as a function of hydration number and temperature: rate constants and product distributions for OD-(D2O)012 + CH3Cl at 200-500 K  

International Nuclear Information System (INIS)

Nucleophilic displacement reactions which are exothermic do not react on every collision in the gas phase. They exhibit a negative temperature dependence, rate constants decreasing with increasing temperature, and reaction at 300 K is quenched dramatically by the addition of only one-three solvate molecules. In each respect nucleophilic displacement differs from proton transfer, as contrasted in the companion paper. Here we report how hydration influences the rate constant and the product distribution of the nucleophilic displacement reaction OD- + CH2Cl = CH3OD + Cl- ?H0 = -50 kcal/mol11 (1) within the temperature range 200-500 K. Such data invite interpretation using hypersurfaces calculated for hydrated reactants

155

New functions for sewage water treatment plants; Nieuwe functies rioolwaterzuiveringsinstallaties  

Energy Technology Data Exchange (ETDEWEB)

The sewage water treatment plant of the future continues to be a place where waste water arrives, but also constitutes an integral part of the surroundings. Waste has become a raw material for nutrient, energy and water plants, or even a combination of these (NEwater plant).Anticipating climate change and increasing sustainability are leading in further developments. [Dutch] De rioolwaterzuiveringsinstallatie (RWZI) van de toekomst blijft een centrale plek waar afvalwater binnenkomt maar is nadrukkelijker een integraal onderdeel van de omgeving. Het is dan ook een nutrienten-, energie- of waterfabriek, of zelfs een NEwaterfabriek, waar afval een grondstof is geworden. Anticiperen op klimaatverandering en vergroting van de duurzaamheid zijn bij de verdere ontwikkeling leidend.

Scheffer, W.

2010-09-15

156

Functionalization of multi-walled carbon nanotubes using water-assisted chemical vapor deposition  

Science.gov (United States)

A simple and novel method, water-assisted chemical vapor deposition (CVD) was developed to functionalize multi-walled carbon nanotubes (MWCNTs) during the synthesis process. The functionalized MWCNTs were characterized using Raman spectroscopy, XPS, TGA, NH3-TPD, SEM and HR-TEM. It was found that new defects are introduced and the amount of acidic groups is increased on the MWCNT surface during the water-assisted CVD process. The amount of C-OH and C-O group on the MWCNT surface is found to be increased from 21.1% to 42% with water vapor assistance. Density functional theory (DFT) was employed to study the chemical behavior of water vapor molecule on the catalyst particle surface of Ni(1 1 1) cluster. Based on the experimental and DFT simulation results, a mechanism for functionalization of MWCNTs by water-assisted CVD is proposed.

Ran, Maofei; Sun, Wenjing; Liu, Yan; Chu, Wei; Jiang, Chengfa

2013-01-01

157

Functionalization of multi-walled carbon nanotubes using water-assisted chemical vapor deposition  

International Nuclear Information System (INIS)

A simple and novel method, water-assisted chemical vapor deposition (CVD) was developed to functionalize multi-walled carbon nanotubes (MWCNTs) during the synthesis process. The functionalized MWCNTs were characterized using Raman spectroscopy, XPS, TGA, NH3-TPD, SEM and HR-TEM. It was found that new defects are introduced and the amount of acidic groups is increased on the MWCNT surface during the water-assisted CVD process. The amount of C–OH and C–O group on the MWCNT surface is found to be increased from 21.1% to 42% with water vapor assistance. Density functional theory (DFT) was employed to study the chemical behavior of water vapor molecule on the catalyst particle surface of Ni(1 1 1) cluster. Based on the experimental and DFT simulation results, a mechanism for functionalization of MWCNTs by water-assisted CVD is proposed. - Graphical abstract: Water is adsorbed and activated on Ni surface, then dissociated into OH and O species, followed by part of OH and O species desorbed from the surface. Finally, the desorbed OH and O species oxidize the unsaturated carbon atoms of carbon nanotubes, form defects and oxygen-containing groups. Highlights: ? MWCNTs were functionalized by water-assisted CVD method. ? Defects and weak-medium acidic sites were created on the MWCNT sidewalls. ? Oxygen-containing groups in functionalized MWCNT were increased from 21.1% to 42%. ? A mechanism for the influence of water vapor on MWCNTs was proposed.MWCNTs was proposed.

158

Bromide as a tracer for studying water movement and nitrate displacement in soils: comparison with stable isotope tracers; Bromid als Tracer zur Untersuchung der Wasserbewegung und der Nitratverlagerung in Boeden: Vergleich mit stabilisotopen Tracern  

Energy Technology Data Exchange (ETDEWEB)

Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and {sup 15}N. Its great advantage over radioactive tracers (e.g. tritium), which outweighs their extreme sensitivity and ease of measurement and which it has in common with stable isotopes, is that it does not require radiation protection measures. However, there are also constraints on the use of bromide as a tracer in soil/water/plant systems. Our own studies on different soils using D{sub 2}O, bromide and [{sup 15}N]-nitrate in lysimeters suggest that the above assumptions on bromide tracers need not always be valid under conditions as they prevail in biologically active soils. As the present paper shows, these studies permit a good assessment of the possibilities and limits to these tracers. [Deutsch] Fuer die Untersuchung der Wasserbewegung sowie der daran gekoppelten Nitrat-Verlagerung ist der Einsatz von Tracern das Mittel der Wahl. Dabei wird Bromid als Tracer haeufig bevorzugt, da es allgemein als ein repraesentativer Tracer fuer Wasser und als konservativer Tracer (nicht involviert in chemische und biologische Bodenprozesse) zur Untersuchung des Anionentransportes in Boeden angesehen wird und es gegenueber den stabilen Isotopen Deuterium und {sup 15}N billiger und einfacher zu bestimmen ist. Gegenueber den radioaktiven Tracern (z.B. Tritium), die zwar sehr empfindlich und einfach messbar sind, besteht der grosse Vorteil, dass, wie bei den stabilen Isotopen, keine Strahlenschutzmassnahmen ergriffen werden muessen. Es gibt jedoch auch einschraenkende Hinweise fuer die Verwendung von Bromid als Tracer im System Boden/Wasser-Pflanze. Eigene Untersuchungen mit D{sub 2}O, Bromid und [{sup 15}N]Nitrat in Lysimetern mit verschiedenen Boeden weisen aber darauf hin, dass die obigen Annahmen fuer Bromid-Tracer unter den Bedingungen von biologisch aktiven Boeden nur bedingt zutreffen und lassen eine gute Einschaetzung der Moeglichkeiten und Grenzen dieser Tracer zu, wie nachstehende Ausfuehrungen zeigen. (orig.)

Russow, R.; Knappe, S. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Bad Lauchstaedt (Germany). Sektion Bodenforschung

1999-02-01

159

Thermodynamic properties, gradients and functions for saturated steam and water  

International Nuclear Information System (INIS)

The tables presented in this report were produced to provide steam and water properties required in dynamic simulations of steam/water systems. In addition to the usual thermodynamic and transport properties of liquid and vapour at saturation, the tables provide certain partial derivatives of one thermodynamic property with respect to another, covering the pressure range from 0.1 to 22.0 MPa. Also tabulated are surface tension, acoustic velocities and isentropic expansion exponents for dry and wet saturated steam, shown only graphically, or not at all, in conventional steam tables. (author)

160

Woody plant willow in function of river water protection  

Directory of Open Access Journals (Sweden)

Full Text Available Coastal area surrounding the river Ibar, in the area between cities of Kosovska Mitrovica and Leposavi? in the north of Kosovo and Metohija, is occupied with seven industrial waste dumps. These dumps were all part of the exploitation and flotation refinement of raw mineral materials, metallurgic refinement of concentrates, chemical industry, industrial refinement and energetic facilities of Trep?a industrial complex. The existing waste dumps, both active and inactive, are of heterogenic chemical composition. Its impact on the river water is shown by the content of heavy metals found in it. Removal of lead, cadmium and zinc would be economically unrewarding, regardless of the technology used. Wooden plant that prevails in this area is white willow. This work is focused on the removal of heavy metals (Pb, Cd and Zn from the water of the river Ibar using white willow. Roots of the willow are cultivated using the method of water cultures in an individual solution of heavy metals and river water sample. The preparation of the samples for analysis was performed by burning the herbal material and dissolving ashes in the appropriate acids. The concentrations of metals were determined by the stripping analysis. In the investigated heavy metal solutions the biomass increase is 25.6% in lead solution, 27.3% in cadmium and 30.7% in zinc solution. The increase of biomass in nutritional solution, without the heavy metals, is 32.4% and in river water sample 27.5%. The coefficient of bioaccumulation in solutions with heavy metals is 1.6% in lead solution, 1.9% in cadmium and 2.2% in zinc solution. Heavy metals accumulation is 18.74 ?g of lead, 20.09 ?g of cadmium and 22.89 ?g of zinc. The coefficient of bioaccumulation of the water samples, that contained 44.83 ?g/dm3 of lead, 29.21 ?g/dm3 of cadmium and 434.00 ?g/dm3 of zinc, during the period of 45 days, was 30.3% for lead, 53.4% for cadmium and 3.9% for zinc. The concentrations of accumulated metals from the river water are 19.01 ?g of lead, 21.85 ?g of cadmium and 23.96 ?g of zinc in grams dry matter. The obtained results indicate that the willow can contribute to the decontamination of moderately contaminated river water from Pb, Cd and Zn.

Babincev Ljiljana M.

2011-01-01

161

Job Displacement Insurance: An Overview  

OpenAIRE

Earnings losses from permanent job separations are a serious threat to the financial security of long-tenured workers. Job displacement insurance is presumably designed to offset these losses, but evidence suggests that consumption smoothing among the long-tenured displaced is seriously incomplete, at least in lightly regulated labor markets. Unemployment and reemployment wage insurance could fully cover these losses, but are costly to provide. Severance pay has emerged as a supplemental, if ...

Parsons, Donald O.

2014-01-01

162

Functional polyelectrolyte multilayer membranes for water purification applications  

International Nuclear Information System (INIS)

Highlights: ? LBL film on the surface and in to the pores was prepared via flow through method. ? The membranes showed high rejection of Congo Red with sufficiently high flux. ? High antifouling ability in terms of both organic and bio fouling was observed. -- Abstract: A diverse set of supported multilayer assemblies with controllable surface charge, hydrophilicity, and permeability to water and solute was fabricated by pressure driven permeation of poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDDA) solution through poly(ethylene terephthalate) (PET) track-etched membranes. The polyelectrolyte multilayer fabrication was confirmed by means of FTIR, SEM, AFM, ellipsometry, zetapotential, and contact angle characterization. The prepared membranes were characterized in terms of their pure water permeability, flux recovery, and resistance to organic and biofouling properties. The antifouling behavior of the membranes was assessed in terms of protein adsorption and antibacterial behavior. Finally, the membranes were tested for rejection of selected water soluble dyes to establish their usefulness for organic contaminant removal from water. The membranes were highly selective and capable of nearly complete rejection of congo red with sufficiently high fluxes. The feasibility of regenerating the prepared membranes fouled by protein was also demonstrated and good flux recovery was obtained. In summary, the multilayer approach to surface and pore modification was shown to enable the design of membranes with the unique combination of desirable separation characteristics, regenerability of the separation layer, and antifouling behavior

163

Water homeostasis, frailty and congnitive function in the nursing home  

Science.gov (United States)

The goal of this study is to develop and test a practical clinical method to assess frailty in nursing homes and to investigate the relationship between cognitive status of the elderly and the balance between water compartments of their body composition. This is a cross-sectional study, conducted a...

164

Functional polyelectrolyte multilayer membranes for water purification applications  

Energy Technology Data Exchange (ETDEWEB)

Highlights: ? LBL film on the surface and in to the pores was prepared via flow through method. ? The membranes showed high rejection of Congo Red with sufficiently high flux. ? High antifouling ability in terms of both organic and bio fouling was observed. -- Abstract: A diverse set of supported multilayer assemblies with controllable surface charge, hydrophilicity, and permeability to water and solute was fabricated by pressure driven permeation of poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDDA) solution through poly(ethylene terephthalate) (PET) track-etched membranes. The polyelectrolyte multilayer fabrication was confirmed by means of FTIR, SEM, AFM, ellipsometry, zetapotential, and contact angle characterization. The prepared membranes were characterized in terms of their pure water permeability, flux recovery, and resistance to organic and biofouling properties. The antifouling behavior of the membranes was assessed in terms of protein adsorption and antibacterial behavior. Finally, the membranes were tested for rejection of selected water soluble dyes to establish their usefulness for organic contaminant removal from water. The membranes were highly selective and capable of nearly complete rejection of congo red with sufficiently high fluxes. The feasibility of regenerating the prepared membranes fouled by protein was also demonstrated and good flux recovery was obtained. In summary, the multilayer approach to surface and pore modification was shown to enable the design of membranes with the unique combination of desirable separation characteristics, regenerability of the separation layer, and antifouling behavior.

Tripathi, Bijay P., E-mail: bijayptripathi@yahoo.com [Department of Nanostructured Materials, Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, 01069 Dresden (Germany); Dubey, Nidhi C. [Department of Nanostructured Materials, Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, 01069 Dresden (Germany); Technische Universität Dresden, Department of Chemistry, 01069 Dresden (Germany); Stamm, M., E-mail: stamm@ipfdd.de [Department of Nanostructured Materials, Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, 01069 Dresden (Germany); Technische Universität Dresden, Department of Chemistry, 01069 Dresden (Germany)

2013-05-15

165

Charge-displacement analysis for excited states  

Energy Technology Data Exchange (ETDEWEB)

We extend the Charge-Displacement (CD) analysis, already successfully employed to describe the nature of intermolecular interactions [L. Belpassi et al., J. Am. Chem. Soc. 132, 13046 (2010)] and various types of controversial chemical bonds [L. Belpassi et al., J. Am. Chem. Soc. 130, 1048 (2008); N. Salvi et al., Chem. Eur. J. 16, 7231 (2010)], to study the charge fluxes accompanying electron excitations, and in particular the all-important charge-transfer (CT) phenomena. We demonstrate the usefulness of the new approach through applications to exemplary excitations in a series of molecules, encompassing various typical situations from valence, to Rydberg, to CT excitations. The CD functions defined along various spatial directions provide a detailed and insightful quantitative picture of the electron displacements taking place.

Ronca, Enrico, E-mail: enrico@thch.unipg.it; Tarantelli, Francesco, E-mail: francesco.tarantelli@unipg.it [Istituto CNR di Scienze e Tecnologie Molecolari, via Elce di Sotto 8, I-06123 Perugia (Italy); Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, via Elce di Sotto 8, I-06123 Perugia (Italy); Pastore, Mariachiara, E-mail: chiara@thch.unipg.it; Belpassi, Leonardo; De Angelis, Filippo [Istituto CNR di Scienze e Tecnologie Molecolari, via Elce di Sotto 8, I-06123 Perugia (Italy); Angeli, Celestino; Cimiraglia, Renzo [Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Ferrara, via Borsari 46, I-44100 Ferrara (Italy)

2014-02-07

166

Comparação entre as medidas inferenciais de edema de membros inferiores utilizando o Leg-O-Meter e o deslocador de água Comparison between inferential measurements of lower limb edema utilizing the Leg-O-Meter and water displacement  

Directory of Open Access Journals (Sweden)

Full Text Available INTRODUÇÃO: A quantificação precisa da severidade e extensão de edema periférico é necessária antes e após a intervenção fisioterapêutica para avaliar a eficiência do tratamento. O objetivo deste estudo foi comparar as medidas de volume em membros inferiores (MMII obtidas com dois instrumentos o Leg-O-Meter (LM e o deslocador de água (DA em um período de 2 semanas. Materiais e métodos: Trinta e uma mulheres portadoras de edema de MMII com idade entre 20 e 70 anos participaram deste estudo. O edema foi inicialmente avaliado pela perimetria (LM dos MMII ao nível do tornozelo e pelo volume de água deslocada após imersão do membro (DA. Após 2 semanas as medidas foram repetidas sem que houvesse alteração na medicação ou na rotina diária. Resultado: O percentual de alteração de edema no membro inferior direito (MID com o LM e com o DA foi 0,3±4,18% e 0,9±3,31% (p=0,21, respectivamente. Para o membro inferior esquerdo o percentual de alteração foi de 0,7±3,44% e 0,5±3,84% (p=0,29, com o LM e o DA, respectivamente. A magnitude da correlação entre as medidas obtidas com o LM e o DL foi alta e significativa, variando de r=0,73 a r=0,83 (pBackground: Precise quantification of the severity and extent of edema is necessary before and after physiotherapeutic intervention, in order to evaluate the efficiency of the treatment. The objective of this study was to compare lower limb (LL volume measurements from two methods: Leg-O-Meter (LM and water displacement (WD, over a two-week interval. Method: Thirty-one women with LL edema, aged between 20 and 70 years, participated in this study. Edema was initially evaluated by circumference measurement (LM at the ankle level, and by means of the volume of water displaced upon immersion of the limb (WD. After 2 weeks, these measurements were repeated without there having been any change in daily routines or medication intake. Results: the percent changes in edema in the right lower limb (RLL using LM and WD were 0.3±4.18% and 0.9±3.31% (p=0.21, respectively. For the left lower limb (LLL the percent changes were 0.7±3.44% and 0.5±3.84% (p=0.29, utilizing LM and WD, respectively. The magnitude of the correlation between the measurements obtained via the two techniques was high and significant, ranging from r=0.73 to r=0.83 (p<0.01. Conclusion: There was no detectable difference in the extent of the LL edema over a two-week period, when the LM and WD techniques were compared.

ABC Oliveira

2006-01-01

167

Cost Structure of the Portuguese Water Industry: a Cubic Cost Function Application  

OpenAIRE

The main scope of this paper is to confirm, or otherwise, the idea usually presented in national reports and strategic programmes for the water sector that the Portuguese water market is a natural monopoly. Based on a multi-product approach (considering the m3 of potable water delivered and wastewater collected as the outputs) we use a cubic functional specification to estimate water utilities cost function, and then to look for the presence of economies of scale and of scope. The estimated r...

Martins, Rita; Fortunato, Adelino; Coelho, Fernando

2006-01-01

168

A method for simulating transient ground-water recharge in deep water-table settings in central Florida by using a simple water-balance/transfer-function model  

Science.gov (United States)

A relatively simple method is needed that provides estimates of transient ground-water recharge in deep water-table settings that can be incorporated into other hydrologic models. Deep water-table settings are areas where the water table is below the reach of plant roots and virtually all water that is not lost to surface runoff, evaporation at land surface, or evapotranspiration in the root zone eventually becomes ground-water recharge. Areas in central Florida with a deep water table generally are high recharge areas; consequently, simulation of recharge in these areas is of particular interest to water-resource managers. Yet the complexities of meteorological variations and unsaturated flow processes make it difficult to estimate short-term recharge rates, thereby confounding calibration and predictive use of transient hydrologic models. A simple water-balance/transfer-function (WBTF) model was developed for simulating transient ground-water recharge in deep water-table settings. The WBTF model represents a one-dimensional column from the top of the vegetative canopy to the water table and consists of two components: (1) a water-balance module that simulates the water storage capacity of the vegetative canopy and root zone; and (2) a transfer-function module that simulates the traveltime of water as it percolates from the bottom of the root zone to the water table. Data requirements include two time series for the period of interest?precipitation (or precipitation minus surface runoff, if surface runoff is not negligible) and evapotranspiration?and values for five parameters that represent water storage capacity or soil-drainage characteristics. A limiting assumption of the WBTF model is that the percolation of water below the root zone is a linear process. That is, percolating water is assumed to have the same traveltime characteristics, experiencing the same delay and attenuation, as it moves through the unsaturated zone. This assumption is more accurate if the moisture content, and consequently the unsaturated hydraulic conductivity, below the root zone does not vary substantially with time. Results of the WBTF model were compared to those of the U.S. Geological Survey variably saturated flow model, VS2DT, and to field-based estimates of recharge to demonstrate the applicability of the WBTF model for a range of conditions relevant to deep water-table settings in central Florida. The WBTF model reproduced independently obtained estimates of recharge reasonably well for different soil types and water-table depths.

O'Reilly, Andrew M.

2004-01-01

169

Boiling water reactor stability analysis by stochastic transfer function identification  

International Nuclear Information System (INIS)

The univariate and the bivariate ARMA models are proposed as the stochastic transfer function models for the identification of BWR systems. This technique has been developed as a new method for on-line system identification, optimum control, and malfunction monitoring of nuclear power plants. The relationships between the stochastic transfer function model and the differential equation model are derived. The estimation algorithms are developed through the related covariance functions and Green's function by the least squares method. It has been shown that the stochastic models can also be used for fitting the stochastic data which are contaminated with sinusoidal waves. Both the univariate and the bivariate modeling are applied in the BWR system identification and stability analysis. The univariate modeling is applied to decompose the pressure dynamics from the neutron data. From both of the normal operation data and the perturbation experiment data, the reactor dynamics are consistently estimated. The dynamics of the reactor core are estimated as a second order mode with a natural frequency of 0.4 Hz and a damping ratio of 0.1. The univariate modeling is also applied to monitor the local performance of the coolant channel in the reactor. The transfer functions between system's variables are obtained by use of bivariate modeling. The obtained transfer functions are closely related to the stability analysis of thermal-hydraulics in the reactor. The transition of the sys in the reactor. The transition of the system dynamics from normal operation to the perturbation experiment are observed

170

Eddy-shape signature in Thorpe's displacement profiles : advances in characterization of turbulent overturns.  

Science.gov (United States)

The detection of inversions in density profiles is commonly used to find locations of vigorous mixing in the ocean. When turbulence, induced by shear or internal wave breaking, is strong enough to overturn the isopycnals, dense water masses can come upon less dense water, leading to an unstable configuration and to mixing. Thorpe (1977) has proposed to compute the local displacement of fluid parcels by adiabatically sorting the density profile, and the variance of this so-called Thorpe's displacement is used as an estimate of the size of turbulent eddies. Thorpe's displacement is also related, via the Ozmidov scale, to the turbulent eddy diffusity and the turbulent dissipation rate, using the formulas from Dillon (1982). Still, little is known about the precise scenario leading to the observed inversions. Thorpe (1977) suggests that internal wave breaking or Kelvin-Helmholtz instabilities can produce inversions. We wanted to see if more information about the dynamics of the overturn could be retrieved from the displacement profile itself. When displayed as function of z, the displacement points d(z) reveals a characteristic zig-zag shape. The zig-zag itself consists of branches with different slopes. Using model-overturns, we show that the inner slope equals 1/2 for a half-turn solid body rotation, while a more sophisticated Rankine vortex overturn model, here employed on half a turn in the vertical, has slopes slightly larger then 1/2 in the interior and larger than 1 along the sides. Also, when the vortex advecttion is longer than half a turn, the Z shape splits itself in different subsets, but still with the same slopes as for a half-turn. In the case of a mixed layer, possibly observed after mixing has occured, displacement points fill a parallelogram with side-edges having a slope of 1. The models are used to interpret overturn shapes in NE-Atlantic Ocean data from moderately deep, turbulent waters above Rockall Bank (off Ireland) and from deep, weakly-stratified waters above Mount Josephine (off Portugal). Dynamically, most overturns are found to resemble the Rankine vortex model overturn and very few a solid body rotation. Thorpe, S. A. Turbulence and Mixing in a Scottish Loch Royal Society of London Philosophical Transactions Series A, 1977, 286, 125-181 Dillon, T. M. Vertical Overturns: A Comparison of Thorpe and Ozmidov Length Scales J. Geophys. Res., AGU, 1982, 87, 9601-9613 H. van Haren and L. Gostiaux. Characterizing turbulent overturns in CTD-data. Submitted to Dynamics of Atmospheres and Oceans.

Gostiaux, Louis; van Haren, Hans

2014-05-01

171

Temporomandibular joint - normal features and disc displacements: magnetic resonance imaging  

International Nuclear Information System (INIS)

Disc displacement of the temporomandibular joint has been defined as an abnormal relationship between the articular disc and the mandibular condyle, fossa and articular eminence. Disc displacements may occur without immediate interference in the function of the joint. Magnetic resonance imaging shows high diagnostic accuracy in the determination of articular disc position and has been indicated as the diagnostic method of choice for soft tissue abnormalities of the temporomandibular joint. The aim of this study is to review the literature including the normal features and different types of disc displacement of the temporomandibular joint as well as the imaging findings, emphasizing the role of magnetic resonance imaging. (author)

172

Shape dependence of the radial distribution function of hydration water around proteins  

Science.gov (United States)

The characterization of hydration water in proteins is important to understand their structure, function and folding properties. A calculation of the shape parameters reveals considerable asymmetry in the shapes of globular proteins. The present study suggests a generalized approach for the calculation of radial distribution of hydration water by accounting for the shape asymmetry in proteins. The surface and radial distribution function is analyzed for three groups of high resolution globular proteins and nonglobular proteins. This generalized approach depicts a considerable difference in the hydration water distribution pattern around aspherical proteins as compared to the earlier method and this difference is more pronounced for nonglobular proteins. The peaks for normalized RDF are found to be sharper compared to those of bulk water. The normalized RDF of hydration water exactly coincides with that of the bulk beyond 8.0 Å. The radial distribution of hydration water as a function of the water-protein distance matches with the experimentally observed distribution of hydration water around myoglobin. The results reveal that the distribution of hydration water is dependent on the shapes of proteins and hence a generalized approach should be used for the calculation of hydration water distribution around proteins, especially for nonglobular proteins.

Rani, Pooja; Biswas, Parbati

2014-08-01

173

Long-time correlation effects on displacement distributions  

International Nuclear Information System (INIS)

The distribution of displacements in a fluid of hard disks is found by molecular dynamics to be non-Gaussian in the long-time limit, as surmised from the moments of the distribution that yield divergent diffusion and Burnett coefficients. On the other hand, for the Lorentz gas of hard disks, the distribution of displacements is Gaussian in the long-time limit and the diffusion coefficient exists, though the autocorrelation functions have power law tails, which lead to divergent Burnett coefficients

174

Ultrasound Elastography Based on Multiscale Estimations of Regularized Displacement Fields  

OpenAIRE

Elasticity imaging is based on the measurements of local tissue deformation. The approach to ultrasound elasticity imaging presented in this paper relies on the estimation of dense displacement fields by a coarse-to-fine minimization of an energy function that combines constraints of conservation of echo amplitude and displacement field continuity. The multiscale optimization scheme presents several characteristics aimed at improving and accelerating the convergence of the m...

Pellot-barakat, Claire; Frouin, Fre?de?rique; Insana, Michael F.; Herment, Alain

2004-01-01

175

Selective removal of copper (II) from natural waters by nanoporous sorbents functionalized with chelating diamines  

OpenAIRE

Copper has been identified as a pollutant of concern by the Environmental Protection Agency (EPA) because of its widespread occurrence and toxic impact in the environment. Three nanoporous sorbents containing chelating diamine functionalities were evaluated for Cu2+ adsorption from natural waters -- ethylenediamine functionalized self-assembled monolayers on mesoporous supports (EDA-SAMMS®), ethylenediamine functionalized activated carbon (AC-CH2-EDA), and 1,10-Phenanthroline functionalized ...

Chouyyok, Wilaiwan; Shin, Yongsoon; Davidson, Joseph; Samuels, William D.; Lafemina, Nikki H.; Rutledge, Ryan D.; Fryxell, Glen E.; Sangvanich, Thanapon; Yantasee, Wassana

2010-01-01

176

Enhanced gas recovery : factors affecting gas-gas displacement efficiency  

Energy Technology Data Exchange (ETDEWEB)

This paper provided details of a joint industry project (JIP) that examined enhanced gas recovery (EGR) from low pressure volumetric reservoirs in advanced stages of exploitation. The aim of the study was to examine the ability of pressure maintenance with waste gas injection to arrest declines in gas production. Laboratory tests were conducted to identify key factors influencing the extent of mixing during gas-gas displacement within porous media. A sensitivity study was also conducted to examine the effects of grid size; molecular diffusion, dispersion on the width of the displacement front; and the effect of gas solubility in water. Both the tests and the experimental studies indicated that methane recovery increased with increased displacement pressures and displacement velocities. CO{sub 2} provided better methane recovery rates at the breakthrough point than nitrogen. The higher solubility of CO{sub 2} in connate water resulted in delayed CO{sub 2} breakthrough. This delay increased rates of natural gas production and reduced CO{sub 2} production costs. The study also demonstrated that molecular diffusion had a dominating effect on methane recovery during low velocity gas-gas displacement. It was concluded that gas-gas displacement prolongs the production life of wells and increases natural gas recovery from volumetric gas reservoirs.13 refs., 2 tabs., 11 figs.

Sim, S.S.K.; Turta, A.T.; Singhal, A.K.; Hawkins, B.F. [Alberta Research Council, Edmonton, AB (Canada)

2008-07-01

177

A facile method to fabricate functionally integrated devices for oil/water separation  

Science.gov (United States)

In this paper, we present a facile method for the fabrication of a functionally integrated device, which has the multi-functions of the oil-containment boom, oil-sorption material, and water/oil-separating film, through a single immersion step in an ethanol solution of stearic acid. During the simple immersion process, the two dominant factors of superhydrophobicity, surface roughness and low-surface-energy coatings, could be accomplished simultaneously. The as-prepared functionally integrated device with superhydrophobicity/superoleophilicity displayed a lower density than that of water, such that it could float on water and act as an oil-containment boom; an efficient oil-absorbing property, which was attributed to the capillary effect caused by micrometer-sized pore structures and could be used as oil-sorption materials; a high oil/water separating efficiency which was suitable for water/oil-separating film. In this way, the functions of oil collection, absorption, and water/oil separation are integrated into a single device, and these functions could work independently, reducing the cost in terms of energy consumption and being versatile for a wide range of applications.In this paper, we present a facile method for the fabrication of a functionally integrated device, which has the multi-functions of the oil-containment boom, oil-sorption material, and water/oil-separating film, through a single immersion step in an ethanol solution of stearic acid. During the simple immersion process, the two dominant factors of superhydrophobicity, surface roughness and low-surface-energy coatings, could be accomplished simultaneously. The as-prepared functionally integrated device with superhydrophobicity/superoleophilicity displayed a lower density than that of water, such that it could float on water and act as an oil-containment boom; an efficient oil-absorbing property, which was attributed to the capillary effect caused by micrometer-sized pore structures and could be used as oil-sorption materials; a high oil/water separating efficiency which was suitable for water/oil-separating film. In this way, the functions of oil collection, absorption, and water/oil separation are integrated into a single device, and these functions could work independently, reducing the cost in terms of energy consumption and being versatile for a wide range of applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr00026b

An, Qi; Zhang, Yihe; Lv, Kaikai; Luan, Xinglong; Zhang, Qian; Shi, Feng

2015-02-01

178

Using the soil and water assessment tool to estimate dissolved inorganic nitrogen water pollution abatement cost functions in central portugal.  

Science.gov (United States)

Coastal aquatic ecosystems are increasingly affected by diffuse source nutrient water pollution from agricultural activities in coastal catchments, even though these ecosystems are important from a social, environmental and economic perspective. To warrant sustainable economic development of coastal regions, we need to balance marginal costs from coastal catchment water pollution abatement and associated marginal benefits from coastal resource appreciation. Diffuse-source water pollution abatement costs across agricultural sectors are not easily determined given the spatial heterogeneity in biophysical and agro-ecological conditions as well as the available range of best agricultural practices (BAPs) for water quality improvement. We demonstrate how the Soil and Water Assessment Tool (SWAT) can be used to estimate diffuse-source water pollution abatement cost functions across agricultural land use categories based on a stepwise adoption of identified BAPs for water quality improvement and corresponding SWAT-based estimates for agricultural production, agricultural incomes, and water pollution deliveries. Results for the case of dissolved inorganic nitrogen (DIN) surface water pollution by the key agricultural land use categories ("annual crops," "vineyards," and "mixed annual crops & vineyards") in the Vouga catchment in central Portugal show that no win-win agricultural practices are available within the assessed BAPs for DIN water quality improvement. Estimated abatement costs increase quadratically in the rate of water pollution abatement, with largest abatement costs for the "mixed annual crops & vineyards" land use category (between 41,900 and 51,900 € tDIN yr) and fairly similar abatement costs across the "vineyards" and "annual crops" land use categories (between 7300 and 15,200 € tDIN yr). PMID:25602550

Roebeling, P C; Rocha, J; Nunes, J P; Fidélis, T; Alves, H; Fonseca, S

2014-01-01

179

Effects of mineral water with high radiation on the immunological function of mice  

International Nuclear Information System (INIS)

66 Kunming mice were randomly divided into 3 groups, drinking tap water and two high radiation mineral water, respectively. At the end of 150 days, samples were collected for the detection of immunological function. The parameters used in observation included histopathological sections of the immunological organ, the number of HB and WBC, the phagocytotic function of peritoneum macrophage and the primary humoral immune response to SRBC. The results showed that only the number of HB has significant difference compared with the control group

180

Job Displacement Among Single Mothers:  

Science.gov (United States)

Given the recent era of economic upheaval, studying the effects of job displacement has seldom been so timely and consequential. Despite a large literature associating displacement with worker well-being, relatively few studies focus on the effects of parental displacement on child well-being, and fewer still focus on implications for children of single parent households. Moreover, notwithstanding a large literature on the relationship between single motherhood and children’s outcomes, research on intergenerational effects of involuntary employment separations among single mothers is limited. Using 30 years of nationally representative panel data and propensity score matching methods, we find significant negative effects of job displacement among single mothers on children’s educational attainment and social-psychological well-being in young adulthood. Effects are concentrated among older children and children whose mothers had a low likelihood of displacement, suggesting an important role for social stigma and relative deprivation in the effects of socioeconomic shocks on child well-being. PMID:25032267

Brand, Jennie E.; Thomas, Juli Simon

2015-01-01

181

Asymmetry in Reproductive Character Displacement  

Directory of Open Access Journals (Sweden)

Full Text Available A commonly held view in studies of character displacement is that character states of both speciesare shifted in areas of sympatry. This view has been confirmed in an overwhelming number of cases for ecologicalcharacter displacement. Excluding species pairs in which one of the two interacting species is found onlywithin the distribution of the other species and species displaying gynogenesis, the pattern of reproductivecharacter displacement is asymmetrical in that the shift in character states between areas of symaptry andallopatry occurs in only one of the two interacting species. Hypotheses for the reasons behind this asymmetryin reproductive character displacement include (1 homogenization by gene flow, (2 other mechanisms of reproductiveisolation, and (3 sufficient reproductive isolation being provided by one of the interacting species exhibitinga pattern of reproductive character displacement. Because reproductive isolation can be achieved by divergenceat any point in a sequence of premating reproductive behaviors and postmating developments, it is necessaryto understand the mechanisms of reproductive isolation of two interacting taxa in areas of sympatry and allopatryand to analyze the relative contributions of potential factors to reproductive isolation to disentangle hypothesesfor the patterns of asymmetry.

Jang, Yikweon

2008-11-01

182

Residual value and production function approaches to valuation of irrigation water in sugar  

OpenAIRE

The main objective of the study was to estimate non-market value of irrigation water as an input in sugar cane production in the Lowveld of Swaziland. This study used two independent approaches to non-market valuation, the residual value and production function approaches, to calculate the value that sugar cane farmers in the Lowveld region of Swaziland attach to irrigation water. The former estimated the average value of water, while the latter estimated the marginal value. Th...

Sacolo, Thabo Thandokuhle

2013-01-01

183

Multiplexed fiber optic displacement sensors  

International Nuclear Information System (INIS)

A multiplexed bend loss type single-mode fiber-optic sensor system was prepared to measure the displacement of several cm of the civil engineering structures such as many bridges, tunnels and various buildings. This bend loss type fiber-optic sensor used the signal difference between two reflection signals due to various bend losses generating at a pair of optical connectors by using OTDR (optical time domain reflectometer) for measuring displacements. The experiments were conducted for showing the measurement feasibility on the range of 10 cm, and the multiplexing experiments were also performed to measure the displacements of 5 measuring positions of an object by setting these 5 fiber-optic sensors on a single mode fiber simultaneously.

184

Adsorption of water on the KNTN (0 0 1) surface: A density functional theory study  

International Nuclear Information System (INIS)

Graphical abstract: - Highlights: • Density functional theory study of water adsorption on K1?yNayTa1?xNbxO3 surface terminations. • Water monomer prefers to adsorb at the K–Na bridge site on the K(Na)O-termination and the Nb top site on the Ta(Nb)O2-termination. • The surface geometry becomes more roughness with the coverage increasing. • The strong interaction between water and substrate results in a band gap increase of KNTN surface. - Abstract: We present a density functional theory study of water adsorption on K1?yNayTa1?xNbxO3 (KNTN) surface terminations. The adsorption configuration and energy are determined and the bond formation between water molecule and KNTN surface are investigated by analysis of difference electron density and partial density of states. Our calculations reveal that the energetically favorable configurations for water monomer adsorption is at the K–Na bridge site on the K(Na)O-termination and the Nb top site on the Ta(Nb)O2-termination. With the coverage increasing, the water–surface interaction per water molecule decreases because of the formation of interwater hydrogen bonds, whereas the surface geometry becomes more roughness. The variation of bandgap for water adsorbed KNTN surface is also studied. We find that the interaction between water and surface would lead to a bandgap increase of KNTN surface, which is correlated to the electrons density redistribution

185

Assessing physiological responses of dune forest functional groups to changing water availability: from Tropics to Mediterranean.  

Science.gov (United States)

Alterations in water availability are important to vegetation as can produce dramatic changes in plant communities, on physiological performance or survival of plant species. Particularly, groundwater lowering and surface water diversions will affect vulnerable coastal dune forests, ecosystems particularly sensitive to groundwater limitation. Reduction of water tables can prevent the plants from having access to one of their key water sources and inevitably affect groundwater-dependent species. The additional impact of drought due to climatic change on groundwater-dependent ecosystems has become of increasing concern since it aggravates groundwater reduction impacts with consequent uncertainties about how vegetation will respond over the short and long term. Sand dune plant communities encompass a diverse number of species that differ widely in root depth, tolerance to drought and capacity to shift between seasonal varying water sources. Plant functional groups may be affected by water distribution and availability differently. The high ecological diversity of sand dune forests, characterized by sandy soils, well or poorly drained, poor in nutrients and with different levels of salinity, can occur in different climatic regions of the globe. Such is the case of Tropical, Meso-mediterranean and Mediterranean areas, where future climate change is predicted to change water availability. Analyses of the relative natural abundances of stable isotopes of carbon (13C/12C) and oxygen (18O/16O) have been used across a wide range of scales, contributing to our understanding of plant ecology and interactions. This approach can show important temporal and spatial changes in utilization of different water sources by vegetation. Accordingly, the core idea of this work is to evaluate, along a climatic gradient, the responses and capacity of different coastal plant communities to adapt to changing water availability. This large-climatic-scale study, covering Brazil, Portugal and Spain, provide an excellent experimental network to study the water dynamics and community functioning in natural ecosystems of high ecological value. To fulfill the main objective, a stable isotope approach (leaf ?13C and xylem+water sources ?18O) was used as a tool to assess physiological performance and water strategies integrated in spatio-temporal water dynamics. Plant functional groups' water use was characterized in a water changing situation (at different seasons) in a climatic gradient. We evaluated stress sensitivity of the functional groups to seasonal changes in water availability in different communities and tried to understand their water use strategy.

Antunes, Cristina; Lo Cascio, Mauro; Correia, Otília; Vieira, Simone; Cruz Diaz Barradas, Maria; Zunzunegui, Maria; Ramos, Margarida; João Pereira, Maria; Máguas, Cristina

2014-05-01

186

Computational study of glycine-(water)3 complex by density functional method  

International Nuclear Information System (INIS)

Glycine-(water)3 complexes have been studied by means of B3LYP density functional method using 6-311++G* basis set. In the complex considered here, the three water molecule are either attached to the carboxylic group or bridge between the amino group and carboxylic group of glycine. Four such complexes are studied. Relaxation energies, two-, three- and four-body interaction energies are obtained by applying many-body analysis to know their role in binding energy of the complex. The results are compared with recent work on glycine-(water)3 complex with (-NH3+) group as proton donor [A. Chaudhari, P.K. Sahu, S.L. Lee, J. Chem. Phys. 120 (2004) 170]. In the most stable structure of glycine-(water)3 complex, the three water molecules are attached to the carboxylic group of glycine and it is 5.3 kcal/mol lower in energy than that of the most stable structure reported earlier. The three-body term from water-water-water interaction in the most stable in this work and that reported earlier is unique since the distances between the water molecules are almost same. The two-body term from water-water interaction has significant contribution to the total two-body term when the distance between water molecules is less than 3 A

187

Fiber Optic Displacement Sensor with New Reflectivity Compensation Method  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a fiber optic displacement sensor with a new reflectivity compensation method is presented. The proposed compensation method is based on two light receiving channels with characteristic displacement sensitivities. The sensitivity characteristic for each channel is achieved by using fibers with different numerical apertures. The ratio of the intensity values of the two receiving channels is a function of the object displacement and fairly independent from the reflectivity of the measured object. The sensor is characterized by a well-defined measurement spot. By use of a focus lens mounted onto the fiber optics probe head, the object displacement range can be extended. The sensor is suitable for measurements with changing object reflectivity and demanding distance ranges.

Ansgar Wego

2013-06-01

188

Functionalization of multi-walled carbon nanotubes using water-assisted chemical vapor deposition  

Energy Technology Data Exchange (ETDEWEB)

A simple and novel method, water-assisted chemical vapor deposition (CVD) was developed to functionalize multi-walled carbon nanotubes (MWCNTs) during the synthesis process. The functionalized MWCNTs were characterized using Raman spectroscopy, XPS, TGA, NH{sub 3}-TPD, SEM and HR-TEM. It was found that new defects are introduced and the amount of acidic groups is increased on the MWCNT surface during the water-assisted CVD process. The amount of C-OH and C-O group on the MWCNT surface is found to be increased from 21.1% to 42% with water vapor assistance. Density functional theory (DFT) was employed to study the chemical behavior of water vapor molecule on the catalyst particle surface of Ni(1 1 1) cluster. Based on the experimental and DFT simulation results, a mechanism for functionalization of MWCNTs by water-assisted CVD is proposed. - Graphical abstract: Water is adsorbed and activated on Ni surface, then dissociated into OH and O species, followed by part of OH and O species desorbed from the surface. Finally, the desorbed OH and O species oxidize the unsaturated carbon atoms of carbon nanotubes, form defects and oxygen-containing groups. Highlights: Black-Right-Pointing-Pointer MWCNTs were functionalized by water-assisted CVD method. Black-Right-Pointing-Pointer Defects and weak-medium acidic sites were created on the MWCNT sidewalls. Black-Right-Pointing-Pointer Oxygen-containing groups in functionalized MWCNT were increased from 21.1% to 42%. Black-Right-Pointing-Pointer A mechanism for the influence of water vapor on MWCNTs was proposed.

Ran Maofei [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Institute of Chemical and Engineering Sciences (ICES), A-STAR, 627833 Singapore (Singapore); Sun Wenjing [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Liu Yan, E-mail: liu_yan@ices.a-star.edu.sg [Institute of Chemical and Engineering Sciences (ICES), A-STAR, 627833 Singapore (Singapore); Chu Wei, E-mail: chuwei1965@scu.edu.cn [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Jiang Chengfa [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China)

2013-01-15

189

Polymeric nanospheres as a displacement fluid in enhanced oil recovery  

Science.gov (United States)

This paper presents the investigation of using nanoscale polyacrylamide-based spheres (nanospheres) as a displacement fluid in enhanced oil recovery (EOR). Coreflood experiments were conducted to evaluate the impact of nanospheres and its concentration dispersed in model formation water on oil recovery during a tertiary oil recovery process. The coreflood results showed that nanospheres can enhance residual oil recovery in the sandstone rock samples and its concentration showed a significant impact into incremental oil. By evaluating the contact angle, it was observed that wettability alteration also might be involved in the possible oil displacement mechanism in this process together with fluid behavior and permeability to water that might divert injected fluid into unswept oil areas and enhance the residual oil recovery. These investigations promote nanospheres aqueous disperse solution as a potential displacement fluid in EOR.

Hendraningrat, Luky; Zhang, Julien

2015-01-01

190

Heavy water effects on the structure, functions and behavior of biological systems  

International Nuclear Information System (INIS)

The H2O substitution for D2O either in environment or in the culture medium of the living systems generates changes in their main functions and composition. In this paper some of the heavy water effects in biological systems such as structural and functional changes were reviewed: normal cell architecture alterations, cell division and membrane functions disturbance, muscular contractility and the perturbations of biological oscillators such as circadian rhythm, heart rate, respiratory cycle, tidal and ultradian rhythm. (authors)

191

Molecular Density Functional Theory for water with liquid-gas coexistence and correct pressure  

CERN Document Server

The solvation of hydrophobic solutes in water is special because liquid and gas are almost at coexistence. In the common hypernetted chain approximation to integral equations, or equivalently in the homogenous reference fluid of molecular density functional theory, coexistence is not taken into account. Hydration structures and energies of nanometer-scale hydrophobic solutes are thus incorrect. In this article, we propose a bridge functional that corrects this thermodynamic inconsistency by introducing a metastable gas phase for the homogeneous solvent. We show how this can be done by a third order expansion of the functional around the bulk liquid density that imposes the right pressure and the correct second order derivatives. Although this theory is not limited to water, we apply it to study hydrophobic solvation in water at room temperature and pressure and compare the results to all-atom simulations. With this correction, molecular density functional theory gives, at a modest computational cost, quantita...

Jeanmairet, Guillaume; Sergiievskyi, Volodymyr; Borgis, Daniel

2015-01-01

192

Rampant exchange of the structure and function of extramembrane domains between membrane and water soluble proteins.  

Science.gov (United States)

Of the membrane proteins of known structure, we found that a remarkable 67% of the water soluble domains are structurally similar to water soluble proteins of known structure. Moreover, 41% of known water soluble protein structures share a domain with an already known membrane protein structure. We also found that functional residues are frequently conserved between extramembrane domains of membrane and soluble proteins that share structural similarity. These results suggest membrane and soluble proteins readily exchange domains and their attendant functionalities. The exchanges between membrane and soluble proteins are particularly frequent in eukaryotes, indicating that this is an important mechanism for increasing functional complexity. The high level of structural overlap between the two classes of proteins provides an opportunity to employ the extensive information on soluble proteins to illuminate membrane protein structure and function, for which much less is known. To this end, we employed structure guided sequence alignment to elucidate the functions of membrane proteins in the human genome. Our results bridge the gap of fold space between membrane and water soluble proteins and provide a resource for the prediction of membrane protein function. A database of predicted structural and functional relationships for proteins in the human genome is provided at sbi.postech.ac.kr/emdmp. PMID:23555228

Nam, Hyun-Jun; Han, Seong Kyu; Bowie, James U; Kim, Sanguk

2013-01-01

193

Decentralised water and wastewater treatment technologies to produce functional water for irrigation  

DEFF Research Database (Denmark)

The EU project SAFIR aimed to help farmers solve problems related to the use of low quality water for irrigation in a context of increasing scarcity of conventional freshwater resources. New decentralised water treatment devices (prototypes) were developed to allow a safe direct or indirect reuse of wastewater produced by small communities/industries or the use of polluted surface water. Water treatment technologies were coupled with irrigation strategies and technologies to obtain a flexible, easy to use, integrated management of the system. The challenge is to apply new strategies and technologies which allow using the lowest irrigation water quality without harming food safety or yield and fruit or derivatives quality. This study presents the results of prototype testing of a small-scale compact pressurized membrane bioreactor and of a modular field treatment system including commercial gravel filters and heavy-metal specific adsorption materials. Decentralised compact pressurised membrane biobooster (MBR), was able to remove up to 99.99% of the inlet Escherichia coli and 98.52% of total coliforms. E. coli was completely removed from irrigation water in 53% of the samples by the last MBR prototype version. In 2008, 100% of samples fulfilled WHO standards (1989) and Global Gap requirement for faecal contamination. MBR removed from inlet flow in the average 82% of arsenic, 82% of cadmium, 97% of chromium, 93% of copper and 99% of lead. Boron and manganese were not removed from permeate. The field treatment system (FTS) proved to be effective against faecal contamination when applied with its complete set up including UV treatment. The sole gravel filter and heavy metal removal device (HMR) cannot provide sufficient and steadily treatment for microbial contamination. Nevertheless, gravel filter can remove up to 60% of E. coli but the removal process was not stable nor predictable. FTS removed 76% of arsenic, 80% of cadmium and copper, 88% of chromium and lead, and up to 97% of zinc. Like the MBR, boron and manganese were not removed from the irrigation water. Gravel filter directly fed with secondary treated wastewater was found able to remove 41% of arsenic, 36% of cadmium and lead, 48% of chromium and 46% of copper. The residual heavy metals concentration after the gravel filter was further reduced by the HMR: 35% for arsenic, 22% for cadmium, 25% for chromium, 33% for copper and 53% for lead.

Battilani, Adriano; Steiner, Michele

2010-01-01

194

Olive response to water availability: yield response functions, soil water content indicators and evaluation of adaptability to climate change  

Science.gov (United States)

Climate evolution, with the foreseen increase of temperature and frequency of drought events during the summer, could cause significant changes in the availability of water resources specially in the Mediterranean region. European countries need to encourage sustainable agriculture practices, reducing inputs, especially of water, and minimizing any negative impact on crop quantity and quality. Olive is an important crop in the Mediterranean region that has traditionally been cultivated with no irrigation and is known to attain acceptable production under dry farming. Therefore this crop will not compete for foreseen reduced water resources. However, a good quantitative knowledge must be available about effects of reduced precipitation and water availability on yield. Yield response functions, coupled with indicators of soil water availability, provide a quantitative description of the cultivar- specific behavior in relation to hydrological conditions. Yield response functions of 11 olive cultivars, typical of Mediterranean environment, were determined using experimental data (unpublished or reported in scientific literature). The yield was expressed as relative yield (Yr); the soil water availability was described by means of different indicators: relative soil water deficit (RSWD), relative evapotranspiration (RED) and transpiration deficit (RTD). Crops can respond nonlinearly to changes in their growing conditions and exhibit threshold responses, so for the yield functions of each olive cultivar both linear regression and threshold-slope models were considered to evaluate the best fit. The level of relative yield attained in rain-fed conditions was identified and defined as the acceptable yield level (Yrrainfed). The value of the indicator (RSWD, RED and RTD) corresponding to Yrrainfed was determined for each cultivar and indicated as the critical value of water availability. The error in the determination of the critical value was estimated. By means of a simulation model of the water flow in the soil-plant-atmosphere system, the indicators of soil water availability were calculated for different soil units in an area of Southern Italy, traditionally cultivated with olive. Simulations were performed for two climate scenarios: reference (1961-90) and future climate (2021-50). The potentiality of the indicators RSWD, RED and RTD to describe soil water availability was evaluated using simulated and experimental data. The analysis showed that RED values were correlated to RTD. The analysis demonstrated that RTD was more effective than RED in representing crop water availability RSWD is very well correlated to RTD and the degree of correlation depends of the period of deficit considered. The probability of adaptation of each cultivar was calculated for both climatic periods by comparing the critical values (and their error distribution) with soil availability indicators. Keywords: Olea europaea, soil water deficit, water availability critical value. The work was carried out within the Italian national project AGROSCENARI funded by the Ministry for Agricultural, Food and Forest Policies (MIPAAF, D.M. 8608/7303/2008)

Riccardi, Maria; Alfieri, Silvia Maria; Basile, Angelo; Bonfante, Antonello; Menenti, Massimo; Monaco, Eugenia; De Lorenzi, Francesca

2013-04-01

195

Estimating Hydrologic Processes from Subsurface Soil Displacements  

Science.gov (United States)

Soil moisture and the processes that control it are important components of the hydrologic cycle, but measuring these processes remains challenging. We have developed a new measurement method that offers flexibility compared to existing technology. The approach is to measure small vertical displacements in the soil which responds proportionally to distributed surface load changes such as variation in the near-surface water content. The instrument may be installed at a depth of several meters to hundreds of meters below the surface. Because the measurement averaging region scales with the depth of the displacement measurements, this approach provides the means for estimating the soil moisture time series over tens of square meters to tens of thousands of square meters. The instrument developed for this application is called a Sand-X, which is short for Sand Extensometer. It is designed for applications in unconsolidated material, ranging from clay to sand. The instrument is simple and relatively inexpensive, and it can be installed in a boring made with a hand auger or with a small drill rig. Studies at the field scale are ongoing at a field site near Clemson, SC. The site is underlain by saprolite weathered primarily from biotite gneiss. Several Sand-X devices are installed at a field site that is instrumented for validating soil moisture, precipitation, and evapotranspiration estimates. These instruments are emplaced at a depth of 6 m and respond to the weight of a vehicle out to 18 m from the well. Calibration is performed by comparing precipitation measurements to the soil displacement response. For example, the coefficient for one installation is roughly 185 nm soil displacement/mm water content change. The resolution of the instrument is approximately 10 nm, so the Sand-X is capable of detecting changes of soil moisture on the order of tenths of one mm in compliant soils like saprolite. A typical soil displacement time series shows alternating periods of abrupt compression and gradual extension of the soil corresponding to periods of rainfall and evaporation respectively. ET estimates based on local, historic, pan evaporation data range from about 1 to 4 mm/da, and estimates of ET based on the Sand-X data track within 25% of these averages for the first half of 2012. Daily ET averages reveal periods of ET at double the monthly average during the rainy season consistent with the increased availability of soil water for evaporation. In addition to ET, the Sand-X is sensitive to changes in barometric pressure and infiltration of soil water. For example, diurnal barometric variations create a signal that is more than 10 times greater than the sensor resolution. We have developed a poroelastic model to characterize the effect of barometric loading. This analysis is used to remove the effect of barometric fluctuations and improve the resolution of hydrologic processes. Other applications for the instrument include characterizing the accumulation or removal of sediments, snow, ice, biomass, etc.

Freeman, C. E.; Murdoch, L. C.; Germanovich, L.; MIller, S.

2012-12-01

196

Free displacer and Ringbom displacer for a Malone refrigerator  

Energy Technology Data Exchange (ETDEWEB)

Malone refrigeration uses a liquid near its critical point (instead of the customary gas) as the working fluid in a Stirling, Brayton, or similar regenerative or recuperative cycle. Thus far, we have focused on the Stirling cycle, to avoid the difficult construction of the high-pressure-difference counterflow recuperator required for a Brayton machine. Our first Malone refrigerator used liquid propylene (C{sub 3}H{sub 6}) in a double-acting 4-cylinder Stirling configuration. First measurements with a free displacer used in a liquid working fluid are presented. The displacer was operated both in harmonic mode and in Ringbom mode, in liquid carbon dioxide. The results are in reasonable agreement with expectations.

Swift, G.W.; Brown, A.O.

1994-05-01

197

Two-Region Model for Soil Water Repellency as a Function of Matric Potential and Water Content  

DEFF Research Database (Denmark)

Soil water repellency (WR) occurs worldwide and affects hydrologic processes such as infiltration, preferential flow, and surface erosion. The degree of WR varies with soil organic C (SOC) and water contents. In this study, we measured WR (by ethanol molarity) as a function of moisture conditions for two soil profiles (17 layers, of which 13 exhibited WR), representing different vegetation and SOC between 0.6 and 14%. Generally, WR was found at SOC ?2%. Based on measured data, a two-region water repellency (TRWR) model was developed. The model assumes two linear regions in a WR vs. pF (=log[-?], where ? is the soil water matric potential in centimeters of H2O) plot, with linear increase in WR from the moisture content where WR first occurs during drying to the maximum WR at pFWR-max, and a linear decrease from pFWR-max until ambient air-dried conditions. The van Genuchten soil water retention model was used to convert WR-? (where ? is the volumetric water content) to WR-pF. The TRWR model fitting parameters, slopes, and intercepts, were all highly correlated with SOC (R2 > 0.8). The TRWR model was tested against an independent data set for five soils with 2 to 12% SOC and predicted well the measured WR-? and WR-pF relations. For high-SOC surface soils, the TRWR model seems promising to predict WR from fully wettable to ambient air-dried conditions, i.e., within the interval where WR-induced fingered water flow probably occurs. Finally, our data imply that clay saturation by SOC (quantified by the so-called Dexter index) is useful for predicting if soils are likely to exhibit WR. Expression of soil water repellency depends on soil water content; however, only a limited amount of predictive description is available to date. In this study, based on experimental data, a simple two-region model was developed to predict the soil water repellency across the entire range of water content from air dryness to complete wetness.

Karunarathna, Anurudda Kumara; MØldrup, Per

2010-01-01

198

Functional traits composition predict macrophytes community productivity along a water depth gradient in a freshwater lake.  

Science.gov (United States)

Functional trait composition of plant communities has been proposed as a helpful key for understanding the mechanisms of biodiversity effects on ecosystem functioning. In this study, we applied a step-wise modeling procedure to test the relative effects of taxonomic diversity, functional identity, and functional diversity on macrophytes community productivity along water depth gradient. We sampled 42 plots and 1513 individual plants and measured 16 functional traits and abundance of 17 macrophyte species. Results showed that there was a significant decrease in taxonomic diversity, functional identity (i.e., stem dry mass content, leaf [C] and leaf [N]), and functional diversity (i.e., floating leaf, mean Julian flowering date and rooting depth) with increasing water depth. For the multiple-trait functional diversity (FD) indices, functional richness decreased, while functional divergence increased with water depth gradient. Macrophyte community productivity was strongly determined by functional trait composition within community, but not significantly affected by taxonomic diversity. Community-weighted means (CWM) showed a two times higher explanatory power relative to FD indices in determining variations in community productivity. For nine of sixteen traits, CWM and FD showed significant correlations with community productivity, although the strength and direction of those relations depended on selected trait. Furthermore, functional composition in a community affected productivity through either additive or opposite effects of CWM and FD, depending on the particular traits being considered. Our results suggested both mechanisms of mass ratio and niche complementarity can operate simultaneously on variations in community productivity, and considering both CWM and FD would lead to a more profound understanding of traits-productivity relationships. PMID:24967072

Fu, Hui; Zhong, Jiayou; Yuan, Guixiang; Ni, Leyi; Xie, Ping; Cao, Te

2014-05-01

199

The Fractal Behavior of Fluid Displacements in Porous Media  

Science.gov (United States)

Using a microcomputer-based imaging workstation, a flow visualization study in two-dimensional porous medium was performed to examine the dynamics of viscous fingering in miscible displacements. Detailed quantitative miscible displacement experiments on a variety of oil recovery fluid systems were performed. The effect of two dimensionless scaling groups, namely gravity number and viscosity ratio, on the displacement behavior was investigated. Based on image analysis, the irregular fingering patterns of the flow visualization experiments were analyzed for fractal behavior. Results indicate that the area swept by the injected fluid in unstable miscible displacements follows a fractal scaling law with a fractal dimension and proportionality constant related to the gravity number and the viscosity ratio. The study shows that the fractal dimension decreases with decreasing gravity number and increasing viscosity ratio. An empirical correlation was then developed which can be used to estimate the fractal dimension and the proportionality constant of miscible displacements as functions of the two scaling groups. These results have potential application in the mathematical modeling of enhanced oil recovery techniques and in the scaling of laboratory displacements to field conditions.

Gharbi, Ridha; Qasem, Fuad; Peters, Ekwere

2000-11-01

200

Attempt of water retention characteristcs estimation as pedotransfer function for organic soils  

OpenAIRE

This paper presents the results of statistical-physical modelling (pedotransfer function) relating soil water content at defined values of soil water potential to selected physical and chemical parameters of organic soils. The two models were developed as the result of the modelling. The independent variables of equations of both models are: ash content, specific surface area, bulk density, pH in KCl and Fe content. The following ranges of determination coefficient values between the measured...

Witkowska-walczak, B.; Sa?…a?‚awia?…a?„ski, C.; Korus, M.

2007-01-01

201

Small Displacement Measurement in Ultrasound: Quantitative Optical Noncontacting Detection Methods  

Science.gov (United States)

In this study the description and development of intensity-based laser interferometric techniques for the detection and measurement of ultrasonic stress waves and their small displacement amplitudes is presented. The dynamic displacement sensitive interferometers described in the following chapters allow the quantitative point -by-point measurement of both in-plane and out-of-plane components of surface displacement motion. These uniquely developed interferometric sensors are: (1) an optical system design for the detection of the surface acoustic wave (Rayleigh wave). The technique is based on the Fourier analysis of coherent light and diffraction imaging properties of an illuminated grating; (2) the design and construction of a two-beam unequal-path laser interferometer for the measurement of out-of-plane surface displacement of ultrasonic waves; (3) extension of a flexible fiber optic probing device which is optically coupled to the test arm of the above two-beam interferometer. This permits scanning of the test surface which may be at some distance from the main optical system components; (4) the design and construction of a laser speckle interferometer for retro-reflective diffusion surfaces in which the in -plane displacements of the ultrasonic wave are interrogated. The inherent advantages of these newly designed optical configurations in terms of their greater simplicity, feasibility, and sensitivity over the conventional counterparts (classical/speckle laser interferometers) are explained. The function-response limitations of these interferometric sensors on lateral displacement resolution, on upper and lower-bound displacement sensitivity (dynamic range), on high-frequency bandwidth probing capability, on low-frequency environmentally associated noise disturbance, and on specularly reflective or diffusively retro-reflective specimen surface preparation are also mentioned. Finally, in a series of experimental observations, the application of a couple of these acoustic sensors in pulsed-excitation ultrasonic testing methods is cited. Specifically, the optically detected ultrasonic signals revealing the true nature of the various surface displacement modes of vibration are presented.

Sarrafzadeh-Khoee, Adel

202

Displacement corrections used in absorbed dose determination  

International Nuclear Information System (INIS)

When an (exposure) calibrated ionization chamber is used for the determination of absorbed dose from a photon beam, the reading of the instrument must be multiplied by a number of factors, one of which is an attenuation correction for phantom material displaced by the chamber. The magnitude of this correction must depend on the size and shape of the ionization chamber as well as the energy of the radiation beam. For cobalt-60 radiation, a single number, 0.985, has generally been used. Recent measurements, however, and ''first scatter'' calculations, of kerma suggest that a more appropriate value for a Farmer-type chamber used in a water phantom would be 0.975. Such a change is small but would be important when dose calculations based on ''in phantom'' measurements are compared to calculations that are based on in air measurements. Values for the attenuation factor for other beam energies have not been generally available. We have carried out ''first scatter'' calculations for a rather wide range of energies and spectra. Measurements in 60Co beams and in a high-energy (25 MV) photon beam support the calculations. A set of proposed displacement correction factors is presented

203

Artificial Neural Network for Displacement Vectors Determination  

Directory of Open Access Journals (Sweden)

Full Text Available An artificial neural network (NN for displacement vectors (DV determination is presented in this paper. DV are computed in areas which are essential for image analysis and computer vision, in areas where are edges, lines, corners etc. These special features are found by edges operators with the following filtration. The filtration is performed by a threshold function. The next step is DV computation by 2D Hamming artificial neural network. A method of DV computation is based on the full search block matching algorithms. The pre-processing (edges finding is the reason why the correlation function is very simple, the process of DV determination needs less computation and the structure of the NN is simpler.

P. Bohmann

1997-09-01

204

Low-frequency dynamics of water absorbed in Nafion membranes as a function of the temperature.  

OpenAIRE

Abstract We performed a neutron scattering study to investigate the dynamical behavior of water absorbed in Nafion at low hydration level (?=6, ? = moles of water/moles of sulfonic acid sites) as a function of temperature in the range 200K-300K. To single out the signal of the confined water the measurements were done on samples hydrated with both H2O and D2O in the same temperature range. Due to the strong incoherent scattering cross section of hydrogen atoms with respect to deu...

Paciaroni, Alessandro; Casciola, Mario; Cornicchi, Elena; Marconi, Matteo; Onori, Giuseppe; Donnadio, A.; Sganappa, M.; Francesco, Alessio

2007-01-01

205

q-exponential distribution in time correlation function of water hydrogen bonds  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english In a series of molecular dynamics simulations we analyzed structural and dynamics properties of water at different temperatures (213 K to 360 K), using the Simple Point Charge-Extended (SPC/E) water. We detected a q-exponential behavior in the history-dependent bond correlation function of hydrogen [...] bonds. We found that q increases with T -1 below approximately 300 K and is correlated to the increase of the tetrahedral structure of water and the subdiffusive motion of the molecules.

M. G., Campo; G. L., Ferri; G. B., Roston.

2009-08-01

206

An Intermolecular Potential Function for Cyclen-Water Derived from Ab-Initio Molecular Orbital Calculations  

Science.gov (United States)

An interaction pair potential function for 1,4,7,10-tetraaza-cyclododecane (cyclen) and water has been derived from ab-initio molecular orbital computations. The 250 computed points of the energy surface for the water-cyclen interaction have been fitted with an analytical potential of the form where A, B. C, and D are constants, and qi, and qj are the atomic charges of the i-th atom of water and the j-th atom of cyclen at infinite separation.

Hannongbua, Supot V.; Rode, Bernd M.

1985-06-01

207

Attempt of water retention characteristcs estimation as pedotransfer function for organic soils  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the results of statistical-physical modelling (pedotransfer function relating soil water content at defined values of soil water potential to selected physical and chemical parameters of organic soils. The two models were developed as the result of the modelling. The independent variables of equations of both models are: ash content, specific surface area, bulk density, pH in KCl and Fe content. The following ranges of determination coefficient values between the measured and predicted water content were estimated for the models: 0.67 < R2 < 0.81 for the first and 0.68 < R2 < 0.91 for second one.

B. Witkowska-Walczak

2007-09-01

208

QSPR with TAU Indices: Water Solubility of Diverse Functional Acyclic Compounds  

Directory of Open Access Journals (Sweden)

Full Text Available The topochemically arrived unique (TAU scheme, developed in valence electron mobile (VEM environment, is unique in that it unravels specific contributions of functionality, branching, shape and size factors to the physicochemical property or biological activity while most other indices give mainly a global contribution of the molecule. QSPR/QSAR studies with TAU indices on different physicochemical properties/biological activities of diverse functional compounds will explore the usefulness of TAU indices in modeling studies. The present communication attempts to correlate water solubility, ln S, of 193 diverse functional acyclic compounds with different TAU indices, namely T, TR, F, B, NV, NP, NI, NX, and NY. Sometimes, TAU relations have been improved further upon inclusion of suitable indicator or integer variables. The statistical quality of the QSPR model has been judged by statistical parameters such as predicted variance Q2, explained variance Ra2, correlation coefficient R, and variance ratio F. This study shows that TAU indices, along with appropriate indicator variables, can predict up to 91.4% and explain 91.9% of the variance of water solubility. The relations can unravel specific contributions of molecular bulk (size, functionality, branching and shape parameters to the water solubility of diverse functional compounds. In general, water solubility increases with increase in functionality and branching, and decreases with increase in molecular bulk. Further, halocarbons and hydrocarbons specifically show reduced water solubility. Some of the hydrocarbons and halogen compounds act as outliers. The TAU index is an important tool in exploring structure-property relationships in view of its potential to unravel specific contributions of different structural parameters like molecular bulk, shape factors, branching, functionality and carbon skeletal structure.

Kunal Roy

2003-07-01

209

Inhibition of water activated by far infrared functional ceramics on proliferation of hepatoma cells.  

Science.gov (United States)

Rare earth (RE)/tourmaline composite materials prepared by the precipitation method are added to the ceramic raw materials at a certain percentage and sintered into RE functional ceramics with high far infrared emission features. Then the far infrared functional ceramics are used to interact with water. The influence of the ceramics on the physical parameters of water is investigated, and the effect of the activated water on the growth of Bel-7402 hepatoma cells cultured in vitro is further studied. The results indicate that, compared with the raw water, the water activated by the ceramics can inhibit the proliferation of hepatoma cells, with statistical probability P < 0.01, which means that the effect is significant. It can be explained that the water activated by the ceramics has a higher concentration of H+, which decreases the potential difference across the cell membrane to release the apoptosis inducing factor (AIF). After entering the cells, the activated water stimulates the mitochondria to produce immune substances that lead tumor cells to apoptosis. PMID:24734643

Zhang, Dongmei; Liang, Jinsheng; Ding, Yan; Meng, Junping; Zhang, Guangchuan

2014-05-01

210

Adsorption of water on the KNTN (0 0 1) surface: A density functional theory study  

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: - Highlights: • Density functional theory study of water adsorption on K{sub 1?y}Na{sub y}Ta{sub 1?x}Nb{sub x}O{sub 3} surface terminations. • Water monomer prefers to adsorb at the K–Na bridge site on the K(Na)O-termination and the Nb top site on the Ta(Nb)O{sub 2}-termination. • The surface geometry becomes more roughness with the coverage increasing. • The strong interaction between water and substrate results in a band gap increase of KNTN surface. - Abstract: We present a density functional theory study of water adsorption on K{sub 1?y}Na{sub y}Ta{sub 1?x}Nb{sub x}O{sub 3} (KNTN) surface terminations. The adsorption configuration and energy are determined and the bond formation between water molecule and KNTN surface are investigated by analysis of difference electron density and partial density of states. Our calculations reveal that the energetically favorable configurations for water monomer adsorption is at the K–Na bridge site on the K(Na)O-termination and the Nb top site on the Ta(Nb)O{sub 2}-termination. With the coverage increasing, the water–surface interaction per water molecule decreases because of the formation of interwater hydrogen bonds, whereas the surface geometry becomes more roughness. The variation of bandgap for water adsorbed KNTN surface is also studied. We find that the interaction between water and surface would lead to a bandgap increase of KNTN surface, which is correlated to the electrons density redistribution.

Wang, Wenhan [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Shen, Yanqing, E-mail: shenyanqing2004@163.com [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wang, Xiaoou; Zhou, Zhongxiang [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Fei, Weidong [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

2014-04-01

211

Fixture for Linearly Variable Displacement Transducers  

Science.gov (United States)

Original point of interest on shear panel tracked throughout loading. Technique and fixture measure out-of-plane displacements on shear panel using linearly variable displacement transducers (LVDT's) while tracking original panel location. Technique adaptable to any size shear panel.

Farley, G. L.; Baker, D. J.

1985-01-01

212

The use of a variable cost function in the regulation of the Italian water industry  

OpenAIRE

The purpose of this study is to estimate a multivariate variable cost function in order to analyze the cost structure of a sample of Italian water distribution companies. The empirical results of this study could be used by the Italian Regulation Authority of this sector for two purposes: first, to improve the actual tariff regulation process, based on a benchmarking of variable costs, and second, to define the optimal size of a service territory in this sector. A variable cost function was e...

Antonioli, Barbara; Filippini, Massimo

2005-01-01

213

Derivatives obtained directly from displacement data  

OpenAIRE

Two flexible shearing methods taking the derivative information directly from the data for displacement measurement are reported. The displacement information is obtained using a holographic recording directly on a CCD (charge-coupled-device) chip. Besides the advantage of taking the displacement information and the derivative information from a same set of data, other characteristics of these methods are that the derivative sensitivity can be controlled after recordings and displacement deri...

Zou, Yunlu; Pedrini, Giancarlo; Tiziani, Hans J.

1994-01-01

214

The advantages of deep ocean water for the development of functional fermentation food.  

Science.gov (United States)

Deep ocean water (DOW) is obtained from 600 m below the sea surface. In recent years, DOW has been applied in the development of fermentation biotechnologies and functional foods. DOW is rich in trace minerals, comprises multiple physiological and health functions, and is able to promote microbe growth; therefore, the application of DOW directly benefits the development of the fermentation industry and functional foods. This study integrated the current health functions and applications of DOW with the latest results from studies related to fermentation biotechnology. Subsequently, the influence of applying DOW in fermented functional food development and the effects in health function improvements were summarized. According to the previous studies, the main reasons for the increased effect of fermented functional foods through the application of DOW are increased generation of functional metabolite contents in the microbes, intrinsic health functions of DOW, and the microbial use of mechanisms of converting the absorbed inorganic ions into highly bioavailable organic ions for the human body. These combined advantages not only enhance the health functions of fermentation products but also provide fermentation products with the intrinsic health functions of DOW. PMID:25661817

Lee, Chun-Lin

2015-03-01

215

Comparison of shock-induced displacements with displacements produced by a centrifuge acceleration  

International Nuclear Information System (INIS)

Verification of the functional reliability of some electrical components under the action of mechanical shock is often desired. As an example, contact chatter (the closure for short-time intervals) of the normally open contact points in a thermal switch is a possible failure model which must be screened out by testing. Theoretically, it should be possible to do this acceptance testing with a centrifuge at a lower cost if one could determine the centrifuge acceleration level needed to produce the maximum displacement that could be realized under a given shock loading. A method was derived to determine this displacement relationship for the two different types of loads. A superposition-of-modes technique was used to develop the relationship. Numerical results are presented for a simple cantilever where closed-form solutions for modal parameters are readily available. The peak response in each mode is determined and all such peaks are summed to determine the maximum that could be realized from a based-excited, haversine acceleration pulse. This numerical result is then compared with the centrifuge-induced displacement to determine the desired relationship. This result was then successfully used to infer the cntrifuge level needed to test a small, mechanically complicated, thermal switch. 3 references, 3 figures

216

Functional water flow pathways and hydraulic regulation in the xylem network of Arabidopsis.  

Science.gov (United States)

In vascular plants, the xylem network constitutes a complex microfluidic system. The relationship between vascular network architecture and functional hydraulic regulation during actual water flow remains unexplored. Here, we developed a method to visualize individual xylem vessels of the 3D xylem network of Arabidopsis thaliana, and to analyze the functional activities of these vessels using synchrotron X-ray computed tomography with hydrophilic gold nanoparticles as flow tracers. We show how the organization of the xylem network changes dynamically throughout the plant, and reveal how the elementary units of this transport system are organized to ensure both long-distance axial water transport and local lateral water transport. Xylem vessels form distinct clusters that operate as functional units, and the activity of these units, which determines water flow pathways, is modulated not only by varying the number and size of xylem vessels, but also by altering their interconnectivity and spatial arrangement. Based on these findings, we propose a regulatory model of water transport that ensures hydraulic efficiency and safety. PMID:25520406

Park, Joonghyuk; Kim, Hae Koo; Ryu, Jeongeun; Ahn, Sungsook; Lee, Sang Joon; Hwang, Ildoo

2015-03-01

217

CHLORINATION BY-PRODUCTS IN DRINKING WATER AND MENSTRUAL CYCLE FUNCTION  

Science.gov (United States)

Chlorination by-Products in Drinking Water and Menstrual Cycle Function Gayle C. Windham1, Kirsten Waller2, Meredith Anderson2, Laura Fenster1, Pauline Mendola3, Shanna Swan4 1California Department of Health Services, Division of Environmental and Occupational Disea...

218

A Metal-free, Three-component Manifold for the C2-Functionalization of 1-Substituted Imidazoles Operating "On Water"  

OpenAIRE

A metal-free, three-component process for the C2-functionalization of N-alkylated imidazoles is reported The multicomponent manifold operates under ‘on water' conditions through the formation of a water-stable (permanent) nucleophilic imidazole carbene (imidazolium ylide). Whereas the incorporated vinyl ether functionality is a convenient handle for further chemical manipulation of the functionalized heterocycle (complexity generation), the use of water as the reaction media gives it a bonu...

Cruz-acosta, Fabio; Armas, Pedro; Garci?a-tellado, Fernando

2010-01-01

219

Zwitterion functionalized carbon nanotube/polyamide nanocomposite membranes for water desalination.  

Science.gov (United States)

We have shown from both simulations and experiments that zwitterion functionalized carbon nanotubes (CNTs) can be used to construct highly efficient desalination membranes. Our simulations predicted that zwitterion functional groups at the ends of CNTs allow a high flux of water, while rejecting essentially all ions. We have synthesized zwitterion functionalized CNT/polyamide nanocomposite membranes with varying loadings of CNTs and assessed these membranes for water desalination. The CNTs within the polyamide layer were partially aligned through a high-vacuum filtration step during membrane synthesis. Addition of zwitterion functionalized CNTs into a polyamide membrane increased both the flux of water and the salt rejection ratio. The flux of water was found to increase by more than a factor of 4, from 6.8 to 28.7 GFD (gallons per square foot per day), as the fraction of CNTs was increased from 0 to 20 wt %. Importantly, the ion rejection ratio increased slightly from 97.6% to 98.6%. Thus, the nanotubes imparted an additional transport mechanism to the polyamide membrane, having higher flow rate and the same or slightly better selectivity. Simulations show that when two zwitterions are attached to each end of CNTs having diameters of about 15 Å, the ion rejection ratio is essentially 100%. In contrast, the rejection ratio for nonfunctionalized CNTs is about 0%, and roughly 20% for CNTs having five carboxylic acid groups per end. The increase in ion rejection for the zwitterion functionalized CNTs is due to a combination of steric hindrance from the functional groups partially blocking the tube ends and electrostatic repulsion between functional groups and ions, with steric effects dominating. Theoretical predictions indicate that an ideal CNT/polymer membrane having a loading of 20 wt % CNTs would have a maximum flux of about 20000 GFD at the conditions of our experiments. PMID:23705642

Chan, Wai-Fong; Chen, Hang-yan; Surapathi, Anil; Taylor, Michael G; Shao, Xiaohong; Marand, Eva; Johnson, J Karl

2013-06-25

220

Displacement based assessment for precast concrete structures: application to a three story plane frame  

OpenAIRE

Starting from the Direct Displacement Based Design (DDBD) procedure, a new assessment method is investigated in order to evaluate precast concrete structures. The proposed assessment procedure (Displacement Based Assessment – DBA) takes into account the moment-curvature and force-displacement relationship of typical precast connections, beam to column and column to foundation, to estimate the system equivalent viscous damping as a function of rotational and translational ductility of the st...

Belleri, Andrea; Torquati, Mauro; Riva, Paolo

2012-01-01

221

Structural, dynamic, and spectroscopic properties of self-consistent charge density functional tight binding water models  

Science.gov (United States)

Because of its importance as a solvent and its many unique properties, water is a widely studied substance. Computational modeling can bring insight to detailed mechanisms of the interactions of water with itself or other chemicals. The accuracy of simulations of aqueous systems are limited by the accuracy of the water model used. A wide range of empirical models which accurately reproduce bulk water have been developed, but are limited to nonreactive systems. Ab initio models can accurately reproduce water properties, including reactions, but are limited to small systems. Semiempirical models can access larger systems and include reactions, but the transferability of the models is limited by the parameterization. The self-consistent charge density functional tight binding (SCC-DFTB) model was developed in the 1990s to have greater transferability and reliance on fewer parameters. The DFTB+ implementation of SCC-DFTB allows for second- and third-order expansions of the density uctuations in the energy. For each of these models the structural, dynamic, and spectroscopic properties of bulk SCC-DFTB water are compared to an empirical model, SPC/E, and experimental properties. Although all of the SCC-DFTB models exhibit some failures characteristic of the parent density functional theory, the third-order models are the best models. The experimental-density third-order model best reproduces the liquid structure and rotational dynamics, while the ambient-density third-order model best reproduces the diffusion and infrared line shape.

Kinnaman, Laura

222

The effects of a brief, water-based exercise intervention on cognitive function in older adults.  

Science.gov (United States)

Physical inactivity is a modifiable risk factor for accelerated cognitive decline in older adults. Water-based exercise provides the same physiological benefits as land-based exercise with reduced risk of acute injury. The current study evaluated the effects of a brief, water-based exercise intervention on cognitive functioning and cardiovascular fitness in a group of community dwelling older adults. The exercise group (n = 27, Mage = 63.26 ± 7.64, 78% female) attended one moderate intensity water aerobics class per day for six consecutive days whereas the control group (n = 33, Mage = 65.67 ± 6.69, 75% female) continued their typical routine. Neuropsychological and cardiovascular fitness tests were given the week before and the week after the intervention to both groups. The exercise group demonstrated significant improvements in cardiovascular fitness, as well as executive function, attention, and memory over controls. This suggests a brief exercise program can provide benefits for older adults. PMID:25638041

Fedor, Andrew; Garcia, Sarah; Gunstad, John

2015-03-01

223

Molecular Density Functional Theory of Water describing Hydrophobicity at Short and Long Length Scales  

CERN Document Server

We present an extension of our recently introduced molecular density functional theory of water [G. Jeanmairet et al., J. Phys. Chem. Lett. 4, 619, 2013] to the solvation of hydrophobic solutes of various sizes, going from angstroms to nanometers. The theory is based on the quadratic expansion of the excess free energy in terms of two classical density fields, the particle density and the multipolar polarization density. Its implementation requires as input a molecular model of water and three measurable bulk properties, namely the structure factor and the k-dependent longitudinal and transverse dielectric susceptibilities. The fine three-dimensional water structure around small hydrophobic molecules is found to be well reproduced. In contrast the computed solvation free-energies appear overestimated and do not exhibit the correct qualitative behavior when the hydrophobic solute is grown in size. These shortcomings are corrected, in the spirit of the Lum-Chandler-Weeks theory, by complementing the functional ...

Jeanmairet, Guillaume; Borgis, Daniel

2013-01-01

224

Electromagnetic device of linear displacement  

International Nuclear Information System (INIS)

The device moves a rod integral with a nuclear reactor control element. It has a grab for the rod operated by a mobil pole drive by a coil carried by a surrounding sealed casing, a second grab with fixed and mobile poles with facing surfaces shaped to limit the variation of magnetic force with distance between them, and a plunger driven by a coil to bear against another mobile pole moved by a coil. The invention proposes a device ensuring a displacement while the impact forces at the different level of the mechanism are reduced

225

Fabrication of amine-functionalized magnetite nanoparticles for water treatment processes  

Energy Technology Data Exchange (ETDEWEB)

Amine-functionalized magnetite nanoparticles are synthesized by a one pot water based process using N-[3-(trimethoxysilyl)propyl]diethylenetriamine (TRIS) as surfactant. The prepared functionalised nanoparticles are characterised by BET surface area measurements, X-ray diffraction, zeta potential measurement, and X-ray photoelectron spectrometry (XPS). The results clearly show the presence of TRIS on the surface of the nanoparticles. XPS analysis indicates the presence of very small amounts of maghemite on the surface of the magnetite nanoparticles. Water treatment test shows that the prepared nanoparticles are capable to remove natural organic matter (NOM) from natural water samples. The removal of NOM by the prepared particles is characterized by analysing the dissolved organic carbon (DOC) content and UV absorbance at 254 nm (UV{sub 254}) after the treatment of the water samples at various doses and treatment times.

Chan, Candace C. P. [University of South Australia, Ian Wark Research Institute (Australia); Gallard, Herve [Universite de Poitiers, Laboratoire de Chimie et Microbiologie de l' Eau (LCME)-UMR CNRS 6008 (France); Majewski, Peter, E-mail: peter.majewski@unisa.edu.au [Mawson Institute, University of South Australia, School of Advanced Manufacturing and Mechanical Engineering (Australia)

2012-03-15

226

Fabrication of amine-functionalized magnetite nanoparticles for water treatment processes  

International Nuclear Information System (INIS)

Amine-functionalized magnetite nanoparticles are synthesized by a one pot water based process using N-[3-(trimethoxysilyl)propyl]diethylenetriamine (TRIS) as surfactant. The prepared functionalised nanoparticles are characterised by BET surface area measurements, X-ray diffraction, zeta potential measurement, and X-ray photoelectron spectrometry (XPS). The results clearly show the presence of TRIS on the surface of the nanoparticles. XPS analysis indicates the presence of very small amounts of maghemite on the surface of the magnetite nanoparticles. Water treatment test shows that the prepared nanoparticles are capable to remove natural organic matter (NOM) from natural water samples. The removal of NOM by the prepared particles is characterized by analysing the dissolved organic carbon (DOC) content and UV absorbance at 254 nm (UV254) after the treatment of the water samples at various doses and treatment times.

227

The thermotidal exciting function for water vapour absorption of solar radiation  

Directory of Open Access Journals (Sweden)

Full Text Available The thermotidal exciting function J is considered, for
the absorption of solar radiation by water vapour, according to the model
derived by Siebert. The Mugge-Moller formula for water vapour absorption
is integrated numerically, using experimental data for the water vapour
concentration in the troposphere and the stratosphere. It appears that
Siebort's formula is a reasonable approximation at low tropospheric levels
but it dramatically overestimates the water vapour thermotidal heating
in the upper troposphere and in the stratosphere. It seems thus possible
that, if the correct vertical profile is employed for J , the amplitudes and
phases of the diurnal temperature oscillations and of the tidal wind speeds
may suffer significant changes from those previously calculated and possibly explain the three hours delay of the observed phases from the computed values.

M. BONAFEDE

1976-06-01

228

Evaluation of two-phase relative permeability and capillary pressure relations for unstable displacements in a pore network  

Energy Technology Data Exchange (ETDEWEB)

A series of displacement experiments was conducted using five wetting-nonwetting immiscible fluid pairs in a homogenous and uniform pore network. The micromodel was initially saturated with either polyethylene glycol 200 (PEG) or water as a wetting fluid, which was subsequently displaced by a nonwetting fluid (dodecane, hexadecane, or mineral oil) at different flow rates. The experiments were designed to allow determinations of nonwetting fluid relative permeabilities ( ), fluid saturations ( ), and capillary pressure heads ( ). In the displacements, nonwetting fluid saturations increased with increasing flow rates for all five fluid pairs, and viscous fingering, capillary fingering, and stable displacement were observed. Viscous fingering occurred when PEG was displaced by either dodecane or hexadecane. For the water displacements, capillary fingers were observed at low capillary numbers. Due to unstable fingering phenomena, values for the PEG displacements were smaller than for the water displacements. A fitting exercise using the Brooks-Corey (1964) relationship showed that the fitted entry pressure heads are reasonably close to the computed entry pressure head. The fitted pore geometry factor, ?? values for the displacements are considerably lower than what is expected for displacements in homogeneous, highly uniform, porous systems, demonstrating the impact of unstable displacement on the apparent value of ?. It was shown that a continuum-based multiphase model could be used to predict the average behavior for wetting fluid drainage in a pore network as long as independently fitted - and - relations are used. The use of a coupled approach through the Brooks-Corey pore geometry factor underpredicts observed values.

Dehoff, Karl J.; Oostrom, Martinus; Zhang, Changyong; Grate, Jay W.

2012-10-29

229

Pressure effects on the reduced partition function ratio for hydrogen isotopes in water  

Science.gov (United States)

We have developed a simple, yet accurate theoretical method for calculating the reduced isotope partition function ratio (RIPFR) for hydrogen of water at elevated pressures. This approach requires only accurate equations of state (EOS) for pure isotopic end-members (H 2O and D 2O), which are available in the literature. The effect of pressure or density on the RIPFR of water was calculated relative to that of ideal-gas water at infinitely low pressure for the temperature range from 0 to 527 °C. For gaseous and low-pressure (ca. ?15 MPa) supercritical phases of water, the RIPFR increases slightly (1-1.3‰) with pressure or density in a fashion similar to those of many other geologic materials. However, in liquid and high-pressure (>20 MPa) supercritical phases, the RIPFR of water decreases (0.5-6‰) with increasing pressure (or density) to 100 MPa. This rather unique phenomenon is ascribed to the inverse molar volume isotope effects (MVIE) of liquid and high-density supercritical waters, V (D 2O) > V (H 2O), while other substances including minerals show the normal MVIE. These theoretical predictions were experimentally confirmed by Horita et al. [Horita, J., Cole, D.R., Polyakov, V.B., Driesner, T., 2002. Experimental and theoretical study of pressure effects on hydrogen isotope fractionation in the system brucite-water at elevated temperatures. Geochim. Cosmochim. Acta66, 3769 - 3788.] for the system brucite-water. Although the P-T ranges for the EOS of normal and heavy waters are rather limited, our modeling indicates that the RIPFR of water continues to decrease with pressure above 100 MPa. The method developed here can be applied to any other geologic fluids, if accurate EOS for their isotopic end-members is available. These results have important implications for the interpretation of high-pressure isotopic partitioning in the Earth, the outer planets, and their moons.

Polyakov, V. B.; Horita, J.; Cole, D. R.

2006-04-01

230

Measurement uncertainty of a fibre-optic displacement sensor  

International Nuclear Information System (INIS)

The measurement uncertainty and linearity of a bundle fibre-optic displacement sensor were studied on a wide range of displacements using experimental and simulation approaches. The theoretical He–Cuomo distribution functions of light intensity yielded the simulated modulation characteristic that best fitted the experimental data in the range of dimensionless distances to the target surface from 0 to 50 but diverged beyond. The coefficient of variation of the output signal of the sensor varied non-monotonically with the distance to the target surface. This variation is suggested to stem from small randomly distributed imperfections on the mirror surface. (paper)

231

Diorganotin(IV) Complexes with Methionine Methyl Ester. Equilibria and Displacement by DNA Constituents  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english The coordination of methionine methyl ester with dimethyltin(IV) (DMT), dibutyltin(IV) (DBT) and diphenyltin(IV) (DPT) was investigated at 25 °C and 0.1 mol dm-3 ionic strength in water for dimethyltin(IV) and in 50 % dioxane-water mixture for dibutyltin(IV) and diphenyltin(IV). Methionine methyl es [...] ter forms 1:1 and 1:2 complexes with diorganotin(IV). The corresponding formation constants were calculated by using the non-linear least-squares program MINIQUAD-75. The concentration distribution of the various complex species was evaluated as a function of pH. The displacement of coordinated methionine methyl ester with some DNA constituents was calculated based on equilibrium aspects.

M.M., Shoukry; Ayser, Al-Alousi; Sameya M., Tarek.

2014-01-01

232

Steering of H- ion beamlet by aperture displacement  

International Nuclear Information System (INIS)

Focussing of multibeamlets produced from a large accelerator grid is a key issue of ion beam application to the neutral beam injector (NBI) of fusion devices. Another issue is highlighted in a case of negative ion based NBI to compensate beamlet deflection inside the extractor, where magnetic field is applied for suppression of electron extraction. Steering of H- beamlet was carried out by displacing apertures in an electrostatic extractor/accelerator composed of four grids, where the beam energy was in the range of ?50 keV. Out of a few combination of grid displacement, displacement of ESG (3rd grid) and/or GRG (4th grid) was found to be successful: 1) The beamlet steering angle of 50 mrad was obtained by displacing the apertures of 9 mm dia. up to 3 mm. It was confirmed that the steering angle was proportional fairly well to the displacement. The characteristic of the steering, i.e., the steering angle as a function of displacement, agrees well with the analysis based on the linear optics theory. 2) Neither significant divergence growth nor the beam interception were observed in the steered beams over a wide range of operation. The H- beams, of which divergent angle was 5 mrad, was obtained even under the beamlet steering. Thus the steering by displacement is suitable for the focusing of negative ion beam generated from multi-aperture grids. 3) It was found that the steering angle was independent of the magnetic field direction in the present extractor structure. This is an advantage of the steering technique for compensation of the beam deflection inside the extractor by magnetic field. (author)

233

Characteristics of children with hip displacement in cerebral palsy  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Hip dislocation in children with cerebral palsy (CP is a common and severe problem. The dislocation can be avoided, by screening and preventive treatment of children with hips at risk. The aim of this study was to analyse the characteristics of children with CP who develop hip displacement, in order to optimise a hip surveillance programme. Methods In a total population of children with CP a standardised clinical and radiological follow-up of the hips was carried out as a part of a hip prevention programme. The present study is based on 212 children followed until 9–16 years of age. Results Of the 212 children, 38 (18% developed displacement with Migration Percentage (MP >40% and further 19 (9% MP between 33 and 39%. Mean age at first registration of hip displacement was 4 years, but some hips showed MP > 40% already at two years of age. The passive range of hip motion at the time of first registration of hip displacement did not differ significantly from the findings in hips without displacement. The risk of hip displacement varied according to CP-subtype, from 0% in children with pure ataxia to 79% in children with spastic tetraplegia. The risk of displacement (MP > 40% was directly related to the level of gross motor function, classified according to the gross motor function classification system, GMFCS, from 0% in children in GMFCS level I to 64% in GMFCS level V. Conclusion Hip displacement in CP often occurs already at 2–3 years of age. Range of motion is a poor indicator of hips at risk. Thus early identification and early radiographic examination of children at risk is of great importance. The risk of hip displacement varies according to both CP-subtype and GMFCS. It is sometimes not possible to determine subtype before 4 years of age, and at present several definitions and classification systems are used. GMFCS is valid and reliable from 2 years of age, and it is internationally accepted. We recommend a hip surveillance programme for children with CP with radiographic examinations based on the child's age and GMFCS level.

Wagner Philippe

2007-10-01

234

On Estimation Accuracy of Points Displacement  

Directory of Open Access Journals (Sweden)

Full Text Available In the paper the estimates of position accuracy are given which are based on consistent and subsequent use of the true and meansquare errors propagation laws. Firstly the covariance matrices MU of the simple functions FX , FY, FZ of measured quantities L i, e.g.of the coordinates X, Y, Z of determined points U, are computed for each of the two measuring epochs compared. In following phasethe acuuracy of the polar coordinates s, ? of the monitored points displacements vectors s are derived. Reliability of the vectorsdepends upon proper relations of the introduced weights pi of the measured quantities Li , upon degrees of freedom in the horizontalnetwork parametric adjustment, upon stableness of the given points (ties K, and upon relative size of the residual systematic errors ciof measured quantities Li in relation to the respective random errors ?i.

Zden?k Nevosád

2009-11-01

235

Structure and dynamics of forsterite-scCO2/H2O interfaces as a function of water content  

Science.gov (United States)

Molecular dynamics (MD) simulations of forsterite surfaces in contact with supercritical carbon dioxide (scCO2) fluids of varying water content were performed to determine the partition of water between the scCO2 fluid and the mineral surface, the nature of CO2 and H2O bonding at the interface, and the regions of the interface that may be conducive to HCO3(2-x)- formation. Calculations of the free energy of the associative adsorption of water onto the (0 1 0) forsterite surface from the scCO2 phase indicated that the formation of a water film up to three-monolayer thick can be exothermic even for water contents below the water saturation concentration of the scCO2 fluid. In MD simulations of scCO2/H2O mixtures in contact with the (0 1 0) forsterite surface, H2O was found to readily displace CO2 at the surface and, therefore, CO2 directly contacted the surface only for water coverages below two monolayers. For thicker water films, a two-monolayer hydration layer formed that CO2 could not penetrate. The MD simulations thus suggest that, in the presence of sufficient water, HCO3(2-x)- formation occurs in the water films and not via direct reaction of CO2 with the forsterite surface. Simulations of the hydroxylated (0 1 0) surface and of the (0 1 1) surface suggested that this conclusion can be extended to forsterite surfaces with different surface structures and/or compositions. The density, diffusion, and degree of hydration of CO2 as well as the extent of CO2/H2O mixing at the interface were all predicted to depend strongly on the thickness of the water-rich film, i.e., on the water content of the scCO2 fluid.

Kerisit, Sebastien; Weare, John H.; Felmy, Andrew R.

2012-05-01

236

Long-Time Mean Square Displacements in Proteins  

CERN Document Server

We propose a method for obtaining the intrinsic, long time mean square displacement (MSD) of atoms and molecules in proteins from finite time molecular dynamics (MD) simulations. Typical data from simulations are limited to times of 1 to 10 ns and over this time period the calculated MSD continues to increase without a clear limiting value. The proposed method consists of fitting a model to MD simulation-derived values of the incoherent intermediate neutron scattering function, $I_{inc}(Q,t)$, for finite times. The infinite time MSD, $$, appears as a parameter in the model and is determined by fits of the model to the finite time $I_{inc}(Q,t)$. Specifically, the $$ is defined in the usual way in terms of the Debye-Waller factor as $I(Q,t = \\infty) = \\exp(- Q^2 /3)$. The method is illustrated by obtaining the intrinsic MSD $$ of hydrated lysozyme powder (h = 0.4 g water/g protein) over a wide temperature range. The intrinsic $$ obtained from data out to 1 ns and to 10 ns is found to be the same. The intrinsi...

Vural, Derya; Smith, Jeremy C; Glyde, Henry R

2013-01-01

237

Network modeling of residual oil displacement after polymer flooding  

Energy Technology Data Exchange (ETDEWEB)

Research on microscopic flow mechanisms can aid in improving oil recovery after polymer flooding. Based on a two-phase water-oil network model, a simulation model for polymer flooding is proposed that considers various percolation mechanisms of the polymer solution, such as thickening, diffusion, adsorption, entrapment and shear degradation. Thus, the pore structure and the rheological fluid properties can be integrated. This network model can provide an effective tool for the study of residual oil displacement after polymer flooding. The distribution laws for residual oil after polymer flooding were studied using this microscopic simulation. Results show that compared to water flooding, polymer flooding can greatly improve oil recovery. Moreover, the residual oil distribution after polymer flooding tends to be more disperse, complex and variable. At the same time, displacement methods and parameters of the residual oil were investigated. Methods such as increasing the viscosity of the injection fluid can be applied, but the viscosity must be very high. Injection of a slug of displacing liquid with low interfacial tension after polymer flooding can decrease irreducible oil saturation and improve the displacement efficiency, but the interfacial tension needs to be extremely low. (author)

Hou, Jian [Department of Petroleum Engineering, China University of Petroleum, Dongying 257061 (China)

2007-11-15

238

Nomarski imaging interferometry to measure the displacement field of MEMS  

CERN Document Server

We propose to use a Nomarski imaging interferometer to measure the out-of-plane displacement field of MEMS. It is shown that the measured optical phase arises both from height and slope gradients. Using four integrating buckets a more efficient approach to unwrap the measured phase is presented, thus making the method well suited for highly curved objects. Slope and height effects are then decoupled by expanding the displacement field on a functions basis, and the inverse transformation is applied to get a displacement field from a measure of the optical phase map change with a mechanical loading. A measurement reproducibility of about 10 pm is achieved, and typical results are shown on a microcantilever under thermal actuation, thereby proving the ability of such a set-up to provide a reliable full-field kinematic measurement without surface modification.

Amiot, F; Amiot, Fabien; Roger, Jean Paul

2006-01-01

239

Immersion freezing of water and aqueous ammonium sulphate droplets initiated by Humic Like Substances as a function of water activity  

Science.gov (United States)

Immersion freezing of water and aqueous (NH4)2SO4 droplets containing Leonardite (LEO) and Pahokee peat (PP) serving as surrogates for Humic Like Substances (HULIS) has been investigated. Organic aerosol containing HULIS are ubiquitous in the atmosphere, however, their potential for ice cloud formation is uncertain. Immersion freezing has been studied for temperatures as low as 215 K and solution water activity, aw, from 0.85-1.0. The freezing temperatures of water and aqueous solution droplets containing LEO and PP are 5-15 K warmer than homogeneous ice nucleation temperatures. Heterogeneous freezing temperatures can be represented by a horizontal shift of the ice melting curve as a function of solution aw, ?aw, by 0.2703 and 0.2466, respectively. Corresponding heterogeneous ice nucleation rate coefficients, Jhet, are (9.6 ± 2.5)×104 and (5.4 ± 1.4)×104 cm-2 s-1 for LEO and PP containing droplets, respectively, and remain constant along freezing curves characterized by ?aw. Consequently predictions of freezing temperatures and kinetics can be made without knowledge of the solute type when relative humidity and IN surface areas are known. The acquired ice nucleation data are applied to evaluate different approaches to fit and reproduce experimentally derived frozen fractions. In addition, we apply a basic formulation of classical nucleation theory (?(T)-model) to calculate contact angles and frozen fractions. Contact angles calculated for each ice nucleus as a function of temperature, ?(T)-model, reproduce exactly experimentally derived frozen fractions without involving free fit parameters. However, assigning the IN a single contact angle for entire population (single-? model) is not suited to represent the frozen fractions. Application of ?-PDF, active sites, and deterministic model approaches to measured frozen fractions yield similar good representations. Thus, from fitting frozen fractions only, the underlying ice nucleation mechanism and nature of the ice nucleating sites cannot be inferred. In contrast to using fitted functions obtained to represent experimental conditions only, we suggest to use experimentally derived Jhet as a function of temperature and aw that can be applied to conditions outside of those probed in laboratory. This is because Jhet(T) is independent of time and IN surface areas in contrast to the fit parameters obtained by representation of experimentally derived frozen fractions.

Rigg, Y. J.; Alpert, P. A.; Knopf, D. A.

2013-02-01

240

Selective removal of copper(II) from natural waters by nanoporous sorbents functionalized with chelating diamines.  

Science.gov (United States)

Copper has been identified as a pollutant of concern by the U.S. Environmental Protection Agency (EPA) because of its widespread occurrence and toxic impact in the environment. Three nanoporous sorbents containing chelating diamine functionalities were evaluated for Cu(2+) adsorption from natural waters: ethylenediamine functionalized self-assembled monolayers on mesoporous supports (EDA-SAMMS), ethylenediamine functionalized activated carbon (AC-CH(2)-EDA), and 1,10-phenanthroline functionalized mesoporous carbon (Phen-FMC). The pH dependence of Cu(2+) sorption, Cu(2+) sorption capacities, rates, and selectivity of the sorbents were determined and compared with those of commercial sorbents (Chelex-100 ion-exchange resin and Darco KB-B activated carbon). All three chelating diamine sorbents showed excellent Cu(2+) removal (approximately 95-99%) from river water and seawater over the pH range 6.0-8.0. EDA-SAMMS and AC-CH(2)-EDA demonstrated rapid Cu(2+) sorption kinetics (minutes) and good sorption capacities (26 and 17 mg Cu/g sorbent, respectively) in seawater, whereas Phen-FMC had excellent selectivity for Cu(2+) over other metal ions (e.g., Ca(2+), Fe(2+), Ni(2+), and Zn(2+)) and was able to achieve Cu below the EPA recommended levels for river and sea waters. PMID:20608701

Chouyyok, Wilaiwan; Shin, Yongsoon; Davidson, Joseph; Samuels, William D; LaFemina, Nikki H; Rutledge, Ryan D; Fryxell, Glen E; Sangvanich, Thanapon; Yantasee, Wassana

2010-08-15

241

Pedotransfer functions to determine water conducting macroporosity in South African soils.  

Science.gov (United States)

Macropores play an important role in the rapid transport of water, solutes and pollutants through the soil. Transport through these pores (>0.5 mm) is dominated by gravitational forces (i.e. matrix forces have low impact) resulting in flow rates orders of magnitude higher than rates that would be predicted, posing problems for modelling and understanding water and solute transport through soils. This study aimed to quantify the water conducting macroporosity (WCM) in a range of soils in South Africa and to develop three pedotransfer functions (PTFs) able to predict WCM. Saturated (K(s)) and unsaturated (K??) conductivities were measured in situ on 120 soil profiles using double ring and tension infiltrometers methods. Differences between K(s) and K?? in conjunction with Poiseuille's law and the capillary rise equation were used to calculate WCM. The first two multiple regression functions made use of all available soil properties influencing WCM using a 'best model' and 'backward' analysis approach respectively. The third model used only easily observable soil properties to predict the WCM. The functions were validated using a double-cross method. Results are encouraging with R² values of 0.78, 0.74 and 0.69 for functions 1, 2 and 3 respectively. PMID:22258688

van Tol, J J; Le Roux, P A L; Hensley, M

2012-01-01

242

Structural, functional, and ACE inhibitory properties of water-soluble polysaccharides from chickpea flours.  

Science.gov (United States)

The present study aimed to characterize and investigate the functional and angiotensin-I converting enzyme (ACE) inhibition activities of chickpea water-soluble polysaccharides (CPWSP). Physico-chemical characteristics were determined by nuclear magnetic resonance spectroscopy (NMR), Fourier transform-infrared spectroscopy (FT-IR) analysis, and X-ray diffractometry (XRD). Functional properties (water holding capacity: WHC, water solubility index: WSI, swelling capacity: SC, oil holding capacity: OHC, foaming, and emulsion properties) and ACE activities were also investigated using well-established procedures. The FT-IR spectra obtained for the CPWSP revealed two significant peaks, at about 3500 and 500cm(-1), which corresponded to the carbohydrate region and were characteristic of polysaccharides. All spectra showed the presence of a broad absorption between 1500 and 670cm(-1), which could be attributed to CH, CO, and OH bands in the polysaccharides. CPWSP had an XRD pattern that was typical for a semi-crystalline polymer with a major crystalline reflection at 19.6°C. They also displayed important techno-functional properties (SWC, WSI, WHC, and OHC) that can be modulated according to temperature. The CPWSP were also noted to display good anti-hypertensive activities. Overall, the results indicate that CPWSP have attractive chemical, biological, and functional properties that make them potential promising candidates for application as alternative additives in various food, cosmetic, and pharmaceutical preparations. PMID:25643994

Mokni Ghribi, Abir; Sila, Assaâd; Maklouf Gafsi, Ines; Blecker, Christophe; Danthine, Sabine; Attia, Hamadi; Bougatef, Ali; Besbes, Souhail

2015-04-01

243

On the mechanism of water oxidation by a bimetallic manganese catalyst: a density functional study.  

OpenAIRE

Density functional theory is used to explore possible mechanisms that lead to water oxidation by a bimetallic manganese catalyst developed by McKenzie and co-workers. On the basis of our calculations we propose that the key active intermediate is a mixed valent Mn(III)(?-O)Mn(IV)-O? oxyl radical species, the oxyl centre being the site of nucleophilic attack by water. The mixed-valent species is in equilibrium with an isomeric diamond-core Mn(IV)(?-O)(2)Mn(IV) structure, which acts as reser...

Sameera, Wm; Mckenzie, Cj; Mcgrady, Je

2011-01-01

244

Van der Waals density functional study of water binding in metal-organic frameworks  

Science.gov (United States)

Metal-organic frameworks (MOFs) are promising candidate materials for gas storage, gas separation and catalysis. However, MOFs are vulnerable to humid air and effective surface area drops dramatically on an exposure to water [1]. In this theoretical study, we investigate the interaction of single water molecule with MOF-74 on different binding sites by using van der Waals density functionals. We also explore how different type of metal cations affect the interaction.[4pt] [1] S. S. Kaye, A. Daily, O. M. Yaghi and J. R. Long, J. Am. Chem. Soc. 129, 14176 (2007).

Lee, Kyuho; Smit, Berend; Neaton, Jeffrey B.

2013-03-01

245

Thyroid Function Changes Related to Use of Iodinated Water in United States Space Program  

Science.gov (United States)

The National Aeronautics and Space Administration (NASA) has used iodination as a method of microbial disinfection of potable water systems in United States spacecraft and long-duration habitability modules. A review of the effects on the thyroid following consumption o iodinated water by NASA astronauts was conducted. Pharmacological doses of iodine consumed by astronauts transiently decreased thyroid function, as reflected in serum TSH values. Although the adverse effects of excess iodine consumption in susceptible individuals are well documented, exposure to high doses of iodine during space flight did not result in a statistically significant increase in long-term thyroid disease in the astronaut population.

McMonigal, Kathleen A.; Braverman, Lewis E.; Dunn, John T.; Stanbury, John B.; Wear, Mary L.; Hamm, Peggy B.; Sauer, Richard L.; Billica, Roger D.; Pool, Sam L.

1999-01-01

246

Protein-functionalized magnetic iron oxide nanoparticles: time efficient potential-water treatment  

International Nuclear Information System (INIS)

Recent advances in nanoscience suggest that the existing issues involving water quality could be resolved or greatly improved using nanomaterials, especially magnetic iron oxide nanoparticles. Magnetic nanoparticles have been synthesized for the development and use, in association with natural coagulant protein for water treatment. The nanoparticles size, morphology, structure, and magnetic properties were characterized by transmission electron microscope, X-ray diffraction, and superconducting quantum interference device magnetometry. Purified Moringa oleifera protein was attached onto microemulsions-prepared magnetic iron oxide nanoparticles (ME-MION) to form stable protein-functionalized magnetic nanoparticles (PMO+ME-MION). The turbidity removal efficiency in both synthetic and surface water samples were investigated and compared with the commonly used synthetic coagulant (alum) as well as PMO. More than 90 % turbidity could be removed from the surface waters within 12 min by magnetic separation of PMO+ME-MION; whereas gravimetrically, 70 % removal in high and low turbid waters can be achieved within 60 min. In contrast, alum requires 180 min to reduce the turbidity of low turbid water sample. These data support the advantage of separation with external magnetic field (magnetophoresis) over gravitational force. Time kinetics studies show a significant enhancement in ME-MION efficiency after binding with PMO implying the availability of large surface of the ME-MIONailability of large surface of the ME-MION. The coagulated particles (impurities) can be removed from PMO+ME-MION by washing with mild detergent or cleaning solution. To our knowledge, this is the first report on surface water turbidity removal using protein-functionalized magnetic nanoparticle.

247

Use of InSAR to identify land-surface displacements caused by aquifer-system compaction in the Paso Robles area, San Luis Obispo County, California, March to August 1997  

Science.gov (United States)

The population in San Luis Obispo County has grown steadily during the 1990s, and some land use has been converted from dry farming to grazing to irrigated vineyards and urban areas. Because insufficient surface-water supplies are available to meet the growing demand, ground-water pumpage has increased and the resulting water-level declines have raised concern that this water resource may become overstressed. One particular concern is whether the larger ground-water basins within the county function as large individual basins or whether subsurface structures divide these large basins into smaller subbasins, as differences in ground-water-level data suggest. Interferometric Synthetic Aperture Radar (InSAR) is used in locating land-surface displacement, which may indicate subsurface structures in ground-water basins by determining seasonal and historical land-surface changes. Owing to the high spatial detail of InSAR imagery, the InSAR-derived displacement maps can be used with ground-water-level data to reveal differential aquifer-system compaction related to the presence of geological structures or the distribution of compressible sediments that may define subbasin boundaries. This report describes InSAR displacement maps of the Paso Robles area of San Luis Obispo County and compares them to maps of seasonal changes in ground-water levels to detect the presence of aquifer-system compaction.

Valentine, David W.; Densmore, Jill N.; Galloway, Devin L.; Amelung, Falk

2001-01-01

248

Site-site direct correlation functions for three popular molecular models of liquid water  

Science.gov (United States)

Direct correlation functions (DCFs) play a pivotal role in the applications of classical density functional theory (DFT) to addressing the thermodynamic properties of inhomogeneous systems beyond the local-density or mean-field approximations. Whereas numerous studies have been dedicated to the radial distribution functions of liquid water - the most important solvent on earth, relatively little attention has been given to the site-site DCFs. The water DCFs are long-ranged and difficult to calculate directly by simulation, and the predictions from conventional liquid-state theories have been rarely calibrated. Here we report a computational procedure for accurate evaluation of the site-site DCFs of liquid water based on three popular molecular models (viz., SPC, SPC/E, and TIP3P). The numerical results provide a benchmark for calibration of conventional liquid-state theories and fresh insights into development of new DFT methods. We show that: (1) the long-range behavior of the site-site DCFs depends on both the molecular model and the thermodynamic condition; (2) the asymptotic limit of DCFs at large distance does not follow the mean-spherical approximation (MSA); (3) individual site-site DCFs are long ranged (˜40 nm) but a summation of all DCF pairs exhibits only short-range behavior (˜1 nm or a few water diameters); (4) the site-site bridge correlation functions behave as the DCFs, i.e., they are also long-ranged while the summation of all bridge correlation functions is short ranged. Our analytical and numerical analyses of the DCFs provide some simple strategies for possible improvement of the numerical performance of conventional liquid-state theories.

Zhao, Shuangliang; Liu, Yu; Liu, Honglai; Wu, Jianzhong

2013-08-01

249

Performance optimization of bundled fiber optic displacement sensors  

Science.gov (United States)

Bundled intensity-modulated fiber optic displacement sensors offer high-speed (kHz-MHz) performance with micrometer-level accuracy over a broad range of axial displacements, and they are particularly well-suited for applications where minimally invasive, non-contacting sensing is desired. Furthermore, differential versions of these sensors have the potential to contribute robustness to fluctuating environmental conditions. The performance limitations of these sensors are governed by the relationship between axial displacement and measured power at the locations of receiving fibers within a bundled probe. Since the propagating transmission's power level is spatially non-uniform, the relative locations of receiving fibers within a bundled probe are related to the sensor's output, and in this way fiber location is related to sensor performance. In this paper, measured power levels are simulated using a validated optical transmission model, and a genetic algorithm is employed for searching the intensity-modulated bundled displacement sensor's design space for bundle configurations that offer high-overall combinations of desired performance metrics (e.g., linearity, sensitivity, accuracy, axial displacement range, etc...). The genetic algorithm determines arrangements of fibers within the bundled probe that optimize a performance-based cost function and have the potential to offer high-performance operation. Multiple converged results of the genetic algorithm generated using different cost function structures are compared. Two optimized configurations are prototyped, and experimental sensor performance is related to simulated performance levels. The prototypes' linearity, sensitivity, accuracy, axial displacement range, and sensor robustness are described, and sensor bandwidth limitations are discussed. This paper has been approved by Los Alamos National Laboratory for unlimited public distribution (LA-UR 12-00642).

Moro, Erik A.; Todd, Michael D.; Puckett, Anthony D.

2012-04-01

250

On the dissolution of lithium sulfate in water: anion photoelectron spectroscopy and density functional theory calculations.  

Science.gov (United States)

The initial dissolution steps of lithium sulfate (Li2SO4) in water were investigated by performing anion photoelectron spectroscopy and density functional theory calculations on the Li2SO4(H2O)n(-) (n = 0-5) clusters. The plausible structures of these clusters and the corresponding neutral clusters were obtained using LC-?PBE/6-311++G(d,p) calculations by comparing the experimental and theoretical vertical electron detachment energies. Two types of structures for bare Li2SO4(-/0) were found: a turtle-shaped structure and a propeller-shaped structure. For Li2SO4(H2O)n(-) cluster anions with n = 1-3, two kinds of isomers derived from the turtle-shaped and propeller-shaped structures of bare Li2SO4(-) were identified. For n = 4-5, these two kinds of isomers present similar structural and energetic features and thus are not distinguishable. For the anionic clusters the water molecules prefer to firstly interact with one Li atom until fully coordinating it. While for the neutral clusters, the water molecules interact with the two Li atoms alternately, therefore, showing a pairwise solvation behavior. The Li-S distance increases smoothly upon addition of water molecules one by one. Addition of five water molecules to Li2SO4 cannot induce the dissociation of one Li(+) ion because the water molecules are shared by two Li(+) ions. PMID:25623553

Feng, Gang; Hou, Gao-Lei; Xu, Hong-Guang; Zeng, Zhen; Zheng, Wei-Jun

2015-02-10

251

What can density functional theory tell us about artificial catalytic water splitting?  

Science.gov (United States)

Water splitting by artificial catalysts is a critical process in the production of hydrogen gas as an alternative fuel. In this paper, we examine the essential role of theoretical calculations, with particular focus on density functional theory (DFT), in understanding the water-splitting reaction on these catalysts. First, we present an overview of DFT thermochemical calculations on water-splitting catalysts, addressing how these calculations are adapted to condensed phases and room temperature. We show how DFT-derived chemical descriptors of reactivity can be surprisingly good estimators for reactive trends in water-splitting catalysts. Using this concept, we recover trends for bulk catalysts using simple model complexes for at least the first-row transition-metal oxides. Then, using the CoPi cobalt oxide catalyst as a case study, we examine the usefulness of simulation for predicting the kinetics of water splitting. We demonstrate that the appropriate treatment of solvent effects is critical for computing accurate redox potentials with DFT, which, in turn, determine the rate-limiting steps and electrochemical overpotentials. Finally, we examine the ability of DFT to predict mechanism, using ruthenium complexes as a focal point for discussion. Our discussion is intended to provide an overview of the current strengths and weaknesses of the state-of-the-art DFT methodologies for condensed-phase molecular simulation involving transition metals and also to guide future experiments and computations toward the understanding and development of novel water-splitting catalysts. PMID:24694041

Mavros, Michael G; Tsuchimochi, Takashi; Kowalczyk, Tim; McIsaac, Alexandra; Wang, Lee-Ping; Voorhis, Troy Van

2014-07-01

252

A Theoretical Model to Predict Both Horizontal Displacement and Vertical Displacement for Electromagnetic Induction-Based Deep Displacement Sensors  

OpenAIRE

Deep displacement observation is one basic means of landslide dynamic study and early warning monitoring and a key part of engineering geological investigation. In our previous work, we proposed a novel electromagnetic induction-based deep displacement sensor (I-type) to predict deep horizontal displacement and a theoretical model called equation-based equivalent loop approach (EELA) to describe its sensing characters. However in many landslide and related geological engineering cases, both h...

Xiong Li; Renyuan Tong; Qing Li; Hongliang Zhou; Nanying Shentu; Hongjian Zhang

2011-01-01

253

Preventing re-displacement through genuine reintegration in Burundi  

Directory of Open Access Journals (Sweden)

Full Text Available Displacement is often part of a cyclical process of conflict anddisplacement. Preventing displacement, therefore, is not only aboutpreventing new displacement but about ensuring that people do notget re-displaced.

Lucy Hovil

2012-12-01

254

Displacement Based Seismic Design Criteria  

International Nuclear Information System (INIS)

The USNRC has initiated a project to determine if any of the likely revisions to traditional earthquake engineering practice are relevant to seismic design of the specialized structures, systems and components of nuclear power plants and of such significance to suggest that a change in design practice might be warranted. As part of the initial phase of this study, a literature survey was conducted on the recent changes in seismic design codes/standards, on-going activities of code-writing organizations/communities, and published documents on displacement-based design methods. This paper provides a summary of recent changes in building codes and on-going activities for future codes. It also discusses some technical issues for further consideration

255

A characteristic function to estimate the longitudinal dispersion coefficient in surface water flows over porous media  

Science.gov (United States)

One-dimensional modelling of solute transport in shallow water flows relies on an accurate approximation of the longitudinal dispersion coefficient, E, especially under transient conditions of the water flow during the solute residence time. Previous approaches have used expressions (e.g., the Rutherford equation) that allow the inclusion of spatiotemporal variability of E during the transport process, but their accuracy is reduced in marked transient regimes since the data were obtained from experimental work in rivers. This work proposes a different approach from experimental work with slow, shallow flows over porous media in fertigation essays, and provides us with a simple, parametric sigmoid function to estimate a priori effective values of E from simple measurements of flow characteristics and variables. The results have been successfully validated and compared to the Rutherford equation approach. Furthermore, the methodology to develop this characteristic function can be easily adapted for application in other practical cases.

Nofuentes, M.; Polo, M. J.

2012-04-01

256

Modeling the energy and momentum dependent loss function of the valence shells of liquid water  

International Nuclear Information System (INIS)

Within the Born approximation the loss function is the important material property for describing the inelastic interaction of charged particles with the extended electronic subsystem of condensed media. Following the dielectric approach as elaborated by Ritchie and co-workers we determine the loss function of liquid water by a two-step process: (i) an optical energy-loss model is deduced by an analytic representation of the available data at the long wavelength limit, and (ii) the momentum dependence is introduced by simple dispersion models which provide characteristic features of the Bethe surface. By this semi-empirical procedure many-body effects such as polarization, correlation and collective excitations, which are still impractical to compute, are accounted for in a self-consistent manner. Effects on the Bethe surface characteristics of liquid water associated with the choice of the optical-data model and its extension to the momentum plane are explored

257

Evaluation of radionuclide transfer functions from drainage basins of fresh water systems  

International Nuclear Information System (INIS)

Radionuclide transfer functions, defined as the amount of radionuclide flowing per unit time from an upstream drainage basin to a water body following a single pulse deposition of radioactive substance, were evaluated using contamination data collected by some European Laboratories in the rivers Po, Pryptiat, Dnieper, Teterev, Uzh and Rhine following the Chernobyl accident. The data analysed here allow detection of two main exponential decay components. The order of magnitude of the short term effective decay constant calculated here is 10-7 s-1 (radionuclides 137Cs, 90Sr and 103Ru). The geometric means of the effective decay constants of the long term component are 1.5 x 10-8 s-1 (137Cs) and 4.9 x 10-9 s-1 (90Sr). A significant non-linearity of 90Sr transfer functions with respect to the water flow through the drainage basin was detected. (author)

258

Energy Deposition in the TESLA Water Dump As a Function of its Size  

International Nuclear Information System (INIS)

The water dump of the future electron-positron collider TESLA has a very special regime. Each pulse of the electron or positron beam should, after crossing the interaction zone, be dumped in a cylindrical water dump. There is a quite important energy to be absorbed by the dump i.e. 8 MW for 250 GeV energy of the beam and 12 MW if the energy of the electrons is raised to 400 GeV. We should be prepared for an intensity of 2.04x1014 electrons/s for 250 GeV and 2.8x1014 electrons/s for 400 GeV case. The energy to be absorbed is important, therefore we tried to calculate the energy losses by all surfaces of the cylindrical water dump as a function of its size. (author)

259

Water  

Science.gov (United States)

... to drink more water Other drinks How much water do you need? top Water is very important, ... you probably need more water. What about bottled water? top Some people like bottled water for its ...

260

Using time-lapse seismic amplitude data to detect variations of pore pressure and fluid saturation due to oil displacement by water: a numerical study based on one-dimensional prestack inversion  

Science.gov (United States)

We describe a numerical study performed to appraise the ability of seismic amplitude data to infer the time evolution of pore pressure and fluid saturation due to hydrocarbon production. To this end, we construct a synthetic, spatially heterogeneous hydrocarbon reservoir model that is subject to numerical simulation of multiphase fluid flow. Hydrocarbon production is assumed in the form of one water-injection well and four oil-producing wells. The synthetic reservoir model exhibits average porosities of 20% and poses significant vertical resolution constraints to the usage of seismic amplitude data to ascertain variations of pore pressure and fluid saturation. We assume the availability of migrated prestack seismic amplitude and use one-dimensional models to simulate trace by trace the seismic amplitude data before and after the onset of production. One-dimensional seismic amplitude data are simulated in time-lapse mode making use of a rock physics model that includes the effect of differential compaction between sands and shales as a function of depth of burial. The sensitivity study presented in this paper is based on one-dimensional inversion and hence sheds light on the vertical resolution properties of noisy seismic amplitude data. Multiphase fluid-flow parameters have a measurable impact on fluid saturation and pore pressure and hence on the spatial distribution and time evolution of elastic parameters. However, the inverted spatial distributions of elastic parameters at best correlate with smooth spatial averages of the actual distributions of pore pressure and fluid saturation. Because for the case under consideration time-lapse seismic amplitude variations are of the order of 5%, such a correlation would be difficult, if not impossible, to ascertain without the use of one-dimensional inversion. We show that the elastic parameters inverted from prestack seismic amplitude data provide more degrees of freedom to discriminate between time variations of pore pressure and fluid saturation in the reservoir compared to distributions of acoustic impedance inverted from poststack seismic amplitude data.

Varela, Omar J.; Torres-Verdín, Carlos; Sen, Mrinal K.; Roy, Indrajit G.

2006-06-01

261

Estimating Entropy of Liquids from Atom-Atom Radial Distribution Functions: Silica, Beryllium Fluoride and Water  

OpenAIRE

Molecular dynamics simulations of water, liquid beryllium fluoride and silica melt are used to study the accuracy with which the entropy of ionic and molecular liquids can be estimated from atom-atom radial distribution function data. All three systems are known to display similar liquid-state thermodynamic and kinetic anomalies due to a region of anomalous excess entropy behaviour where entropy rises on isothermal compression. The pair correlation entropy is demonstrated to...

Sharma, Ruchi; Agarwal, Manish; Chakravarty, Charusita

2008-01-01

262

Chlorination by-products in drinking water and menstrual cycle function.  

OpenAIRE

We analyzed data from a prospective study of menstrual cycle function and early pregnancy loss to explore further the effects of trihalomethanes (THM) on reproductive end points. Premenopausal women ((italic)n(/italic) = 403) collected urine samples daily during an average of 5.6 cycles for measurement of steroid metabolites that were used to define menstrual parameters such as cycle and phase length. Women were asked about consumption of various types of water as well as other habits and dem...

Windham, Gayle C.; Waller, Kirsten; Anderson, Meredith; Fenster, Laura; Mendola, Pauline; Swan, Shanna

2003-01-01

263

Evaluation of water retention capacity and flood control function of the forest catchment  

OpenAIRE

This research quantitatively evaluates the water retention capacity and flood control function of the forest catchments by using hydrological data of the large flood events which happened after the serious droughts. The objective sites are the Oodo Dam and the Sameura Dam catchments in Japan. The kinematic wave model, which considers saturated and unsaturated sub-surface soil zones, is used for the rainfall-runoff analysis. The result shows that possible storage volume of the Oodo Dam catchme...

Sawai, Nobuhiko; Takara, Kaoru; Kobayashi, Kenichiro

2013-01-01

264

Simulation and Visualisation of Functional Landscapes: Effects of the Water Resource Competition between Plants  

OpenAIRE

Vegetation ecosystem simulation and visualisation are challenging topics involving multidisciplinary aspects. In this paper, we present a new generic frame for the simulation of natural phenomena through manageable and interacting models. It focuses on the functional growth of large vegetal ecosystems, showing coherence for scales ranging from the individual plant to communities and with a particular attention to the effects of water resource competition between plants. The proposed approach ...

Le Chevalier, Vincent; Jaeger, Marc; Mei, Xing; Courne?de, Paul-henry

2007-01-01

265

Structure and Dynamics of Forsterite-scCO2/H2O Interfaces as a Function of Water Content  

Energy Technology Data Exchange (ETDEWEB)

Molecular dynamics (MD) simulations of forsterite surfaces in contact with supercritical carbon dioxide (scCO2) fluids of varying water content were performed to determine the partition of water between the scCO2 fluid and the mineral surface, the nature of CO2 and H2O bonding at the interface, and the regions of the interface that may be conducive to HxCO3(2-x)- formation. Calculations of the free energy of the associative adsorption of water onto the (010) forsterite surface from the scCO2 phase indicated that the formation of a water film up to three-monolayer thick can be exothermic even for water contents below the water saturation concentration of the scCO2 fluid. In MD simulations of scCO2/H2O mixtures in contact with the (010) forsterite surface, H2O was found to readily displace CO2 at the surface and, therefore, CO2 directly contacted the surface only for water coverages below two monolayers. For thicker water films, a two-monolayer hydration layer formed that CO2 could not penetrate. Simulations of the hydroxylated (010) surface and of the (011) surface suggested that this conclusion can be extended to forsterite surfaces with different surface structures and/or compositions. The density, diffusion, and degree of hydration of CO2 as well as the extent of CO2/H2O mixing at the interface were all predicted to depend strongly on the thickness of the water-rich film, i.e., on the water content of the scCO2 fluid.

Kerisit, Sebastien N.; Weare, John H.; Felmy, Andrew R.

2012-05-01

266

Water balance and renal function in two species of African lungfish Protopterus dolloi and Protopterus annectens.  

Science.gov (United States)

The basic physiology of water balance and kidney function was characterized in two species of African lungfish, Protopterus dolloi and Protopterus annectens. Diffusive water efflux rate constants were low (0.13 h(-1)-0.38 h(-1) in various series) relative to values in freshwater teleost fish. Efflux rate constants increased approximately 3-fold after feeding in both species, and were greatly decreased after 8 months terrestrialization (P. dolloi only tested). Urine flow rates (UFR, 3.9-5.2 mL kg(-1) h(-1)) and glomerular filtration rates (GFR, 6.6-9.3 mL kg(-1) h(-1)) were quite high relative to values in most freshwater teleosts. However urinary ion excretion rates were low, with net re-absorption of >99% Na(+), >98% Cl(-), and >78% Ca(2+) from the primary filtrate, comparable to teleosts. Net water re-absorption was significantly greater in P. dolloi (56%) than in P. annectens (23%). We conclude that renal function in lungfish is similar to that in other primitive freshwater fish, but there is an interesting dichotomy between diffusive and osmotic permeabilities. Aquatic lungfish have low diffusive water permeability, an important pre-adaptation to life on land, and in accord with greatly reduced gill areas and low metabolic rates. However osmotic permeability is high, 4-12 times greater than diffusive permeability. A role for aquaporins in this dichotomy is speculated. PMID:18835584

Patel, Monika; Iftikar, Fathima I; Smith, Richard W; Ip, Yuen K; Wood, Chris M

2009-02-01

267

Effects of water temperature change on immune function in surf clams, Mactra veneriformis (Bivalvia: Mactridae).  

Science.gov (United States)

Surf clam, Mactra veneriformis is one of the crucial fishery resources in Korea. This study was performed to examine the immune functions of the surf clam under the stress of water temperature changes at 10 degrees C, 20 degrees C or 30 degrees C for 24h. Viable bacterial counts (VBC), total haemocyte count (THC), phagocytic activity, lysozyme activity, NRR times and SOD activity were assessed in three different water temperature groups. Clams held at 10 degrees C decreased in THC, lysozyme activity and NRR times, but phagocytic activity was increased. The highest temperature (30 degrees C) significantly increased in THC, whereas it decreased in phagocytic activity, lysozyme activity and NRR times. In clams maintained at 20 degrees C, phagocytic activity, lysozyme activity and NRR times were increased whereas THC was somewhat decreased with respect to clams held at 30 degrees C. However, water temperature changes did not elicit any alteration of VBC and SOD activity. The present study demonstrates that acute water temperature change affects the haemocytic and haemolymphatic functions, reducing immunosurveillance in stressed surf clam, M. veneriformis. PMID:19524589

Yu, Jin Ha; Song, Jae Hee; Choi, Min Chul; Park, Sung Woo

2009-09-01

268

Estuary water-stage forecasting by using radial basis function neural network  

Science.gov (United States)

The Radial basis function neural network (RBFNN) has been successfully applied to many tasks due to its powerful properties in classification and functional approximation. This paper presents a novel RBFNN for water-stage forecasting in an estuary under high flood and tidal effects. The RBFNN adopts a hybrid two-stage learning scheme, unsupervised and supervised learning. In the first scheme, fuzzy min-max clustering is proposed for choosing best patterns for cluster representation in an efficient and automatic way. The second scheme uses supervised learning, which is a multivariate linear regression method to produce a weighted sum of the output from the hidden layer. Since this network has only one layer using a supervised learning algorithm, its training process is much faster than the error back propagation based multilayer perceptrons. Moreover, only one parameter, ?, must be determined manually. The other parameters used in this model can be adjusted automatically by model training. The water-stage data of the Tanshui River under tidal effect are used to construct a water-stage forecasting model that can also be used during flood. The results show that the RBFNN can be applied successfully and provide high accuracy and reliability of water-stage forecasting in an estuary.

Chang, Fi-John; Chen, Yen-Chang

2003-01-01

269

Estimating marginal value of water for irrigated olive grove with the production function method  

Energy Technology Data Exchange (ETDEWEB)

Economic valuation of irrigation water is done through the use of production functions for the case of the olive grove. In order to do so the integration of an agronomic model (based on the production function) and an economic model linked to the profitability of the crop (the ratio of revenue and operating costs) in the area under study is proposed. The study case encompasses the Guadalbullon River Sub-basin area, belonging to the Guadalquivir River Hydrologic Demarcation (Southern Spain). Within the overall deficit of the Guadalquivir River basin, the Guadalbullon River poses a special problem as it is unregulated and there are important irrigated fields on its banks, most of them olive groves. Net marginal value of water obtained (having deducted the variable costs of production including harvesting and irrigation) is Euros 0.60 m{sup 3} for the allocation of 1,000 m{sup 3} ha{sup -}1 and Euros 0.53 m{sup 3} for the water right allowance of 1,500 m{sup 3} ha{sup -}1 (average for period 2005/2008). The results obtained support the recommendation by other authors suggesting the use of deficit irrigation in olive, additionally the high value of water estimated contributes to explain the substantial increase in irrigated olive area in Andalucia. (Author) 37 refs.

Mesa-Jurado, M. A.; Berbel, J.; Orgaz, F.

2010-07-01

270

Policies for displaced workers: An american perspective  

OpenAIRE

American employment policy for displaced workers started in the Great Depression with programs for the employment service, unemployment insurance, work experience, and direct job creation. Assistance for workers displaced by foreign competition emerged in the 1960s along with formalized programs for occupational job skill training. The policy focus on displaced workers was sharpened in the 1980s through the Worker Adjustment and Retraining Notification Act and the Economic Dislocation and Wor...

O Leary, Christopher J.

2010-01-01

271

Displacement measurement system for linear array detector  

International Nuclear Information System (INIS)

It presents a set of linear displacement measurement system based on encoder. The system includes displacement encoders, optical lens and read out circuit. Displacement read out unit includes linear CCD and its drive circuit, two amplifier circuits, second order Butterworth low-pass filter and the binarization circuit. The coding way is introduced, and various parts of the experimental signal waveforms are given, and finally a linear experimental test results are given. The experimental results are satisfactory. (authors)

272

A New system for Measuring Electrical Conductivity of Water as a Function of Admittance  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a new system for measuring water conductivity as a function of electrophysical property (admittance. The system is cheap and its manufacturing is easy. In addition, it dose not require any sort of electrolysis and calibration. The system consists of four electrodes made of silver (Ag 92.5 g to Cu 7.5 g fixed in a plastic tube filled by water which allows the use of two and four electrode setups. The admittance (reciprocal of impedance is measured for different water sources (distilled, rainfall, mineral, river and tap water using different frequencies between 50 Hz and 100 kHz. These measurements were taken twice, once with four electrodes and another with two electrodes of two modes (inner and outer electrodes. The results have shown good correlation between the measured admittance and the conductivity of all the water sources and the best correlation was found at low frequencies between 50 Hz and 20 kHz. The highest efficiency can be achieved by performing the four electrodes system which allows circumventing the effect of the electrode impedance. This result makes the system efficient compared to traditional conductivity meters which usually require high frequencies for good operation.

doi:10.5617/jeb.203
J Electr Bioimp, vol. 2, pp. 86-92, 2011

Haval Yacoob

2011-03-01

273

Comparison of Water Production Functions for Winter Wheat in Mashhad Region  

Directory of Open Access Journals (Sweden)

Full Text Available In order to determine the water production functions for winter wheat (Variety, C73,5, an experiment was conducted in through of a complete randomized block design with 9 treatments and 3 replications in Mashhad region. While the first treatment (as a control treatment was selected on the basis of irrigation in all growth stages of growing season, six treatments were selected on the basis of an irrigation cut in the six stages of growth season and two remaining treatments were also selected on the basis of a constant reduction of irrigation to the amount of 20 and 60 percent. In general the water stress was caused that the amounts of depth percolation were calculated negatively which was an indication of the water uptake from below the root zone. According to results, models of the yield in per unit of area had a higher correlation coefficient of determination in relation to the models of the yield in per unit of water. The derived sensitivity coefficients indicated that the winter grain formation and flowering stages were respectively the most sensitive stages of the growth season stages to the water deficit. There are some differences between these computed sensitivity coefficients and the amounts reported by the other researchers. Probably the variety, degree of stress, the climatic conditions and some unknown factors may explain these differences.

B. Ghahraman

2005-10-01

274

Contrast-transfer improvement for electrode displacement elastography  

Science.gov (United States)

Electrode displacement elastography is a strain imaging method that can be used for in-vivo imaging of radiofrequency ablation-induced lesions in abdominal organs such as the liver and kidney. In this technique, tissue motion or deformation is introduced by displacing the same electrode used to create the lesion. Minute displacements (on the order of a fraction of a millimetre) are applied to the thermal lesion through the electrode, resulting in localized tissue deformation. Ultrasound echo signals acquired before and after the electrode-induced displacements are then utilized to generate strain images. However, these local strains depend on the modulus distribution of the tissue region being imaged. Therefore, a quantitative evaluation of the conversion efficiency from modulus contrast to strain contrast in electrode-displacement elastograms is warranted. The contrast-transfer efficiency is defined as the ratio (in dB) of the observed elastographic strain contrast and the underlying true modulus contrast. It represents a measure of the efficiency with which elastograms depict the underlying modulus distribution in tissue. In this paper, we develop a contrast-transfer efficiency formalism for electrode displacement elastography (referred to as contrast-transfer improvement). Changes in the contrast-transfer improvement as a function of the underlying true modulus contrast and the depth of the inclusion in the simulated phantom are studied. We present finite element analyses obtained using a two-dimensional mechanical deformation and tissue motion model. The results obtained using finite element analyses are corroborated using experimental analysis and an ultrasound simulation program so as to incorporate noise artifacts.

Bharat, Shyam; Varghese, Tomy

2006-12-01

275

Effect of displacement on resistance and capacitance of polyaniline film  

International Nuclear Information System (INIS)

This paper investigates the properties of displacement sensors based on polyaniline (PANI) films. About 1 wt% of PANI micropowder is mixed and stirred in a solution of 90 wt% water and 10 wt% alcohol at room temperature. The films of PANI are deposited from solution by drop-casting on Ag electrodes, which are preliminary deposited on glass substrates. The thicknesses of the PANI films are in the range of 20 ?m–80 ?m. A displacement sensor with polyaniline film as an active material is designed and fabricated. The investigations showed that, on average, the AC resistance of the sensor decreases by 2 times and the capacitance accordingly increases by 1.6 times as the displacement changes in the range of 0 mm–0.5 mm. The polyaniline is the only active material of the displacement sensor. The resistance and capacitance of the PANI changes under the pressure of spring and elastic rubber, and this pressure is created by the downward movement of the micrometer. (general)

276

Lung function in subjects exposed to crude oil spill into sea water  

International Nuclear Information System (INIS)

A Greek oil-tanker ran aground, resulting in a huge oil spill along the costal areas of Karachi, Pakistan. The purpose of this study was to assess the lung function and follow up change after one year in subjects exposed to crude oil spill in sea water. It was a cross sectional study with follow up in 20 apparently healthy, non-smoking, male workers, who were exposed to a crude oil spill environment during oil cleaning operation. The exposed group was matched with 31 apparently healthy male control subjects. Pulmonary function test was performed using an electronic Spirometer. Subjects exposed to polluted air have significant reduction in forced vital capacity (FVC), forced expiratory volume in first second (FEV1), forced expiratory flow (FEF25-75%) and maximum voluntary ventilation (MVV) compared to their matched controls. This impairment was reversible and lung functions parameters were improved when the subjects were withdrawn from the polluted air environment

277

Lung function in subjects exposed to crude oil spill into sea water  

Energy Technology Data Exchange (ETDEWEB)

A Greek oil-tanker ran aground, resulting in a huge oil spill along the costal areas of Karachi, Pakistan. The purpose of this study was to assess the lung function and follow up change after one year in subjects exposed to crude oil spill in sea water. It was a cross sectional study with follow up in 20 apparently healthy, non-smoking, male workers, who were exposed to a crude oil spill environment during oil cleaning operation. The exposed group was matched with 31 apparently healthy male control subjects. Pulmonary function test was performed using an electronic Spirometer. Subjects exposed to polluted air have significant reduction in forced vital capacity (FVC), forced expiratory volume in first second (FEV{sub 1}), forced expiratory flow (FEF{sub 25-75%}) and maximum voluntary ventilation (MVV) compared to their matched controls. This impairment was reversible and lung functions parameters were improved when the subjects were withdrawn from the polluted air environment.

Meo, Sultan Ayoub [Department of Physiology, College of Medicine, King Saud University, P.O. Box 2925, Riyadh 11461 (Saudi Arabia)], E-mail: sultanmeo@hotmail.com; Al-Drees, Abdul Majeed [Department of Physiology, College of Medicine, King Saud University, P.O. Box 2925, Riyadh 11461 (Saudi Arabia); Meo, Imran M.U. [Hamdard College of Medicine and Dentistry, Hamdard University, Karachi (Pakistan); Al-Saadi, Muslim M. [Department of Pediatrics, College of Medicine, King Saud University, Riyadh (Saudi Arabia); Azeem, Muhammad Abdul [Department of Physiology, Ummal Qura University, Mecca (Saudi Arabia)

2008-01-15

278

Effect of calcium and water injection on structure-function relationships of cheese.  

Science.gov (United States)

Our objectives were to determine the effect of calcium and water injection on cheese structure and to relate changes in structure to changes in functional properties of cheese. Cheese with fat and moisture content similar to that of low-moisture part-skim Mozzarella was made according to a direct-acid, stirred/pressed-curd procedure. The cheese was then cut into blocks that were high-pressure-injected from one to five times, with either water or a 40% calcium chloride solution. Successive injections were performed 24 h apart. After 42 d of refrigerated storage, cheese microstructure and functionality were analyzed. When injected three or more times, water tended to increase cheese weight. The control, uninjected cheese, had the typical structure of a stirred/pressed-curd cheese: protein matrix interspersed with areas that originally contained fat and/or serum. Injecting water increased the area of cheese matrix occupied by protein, but it did not affect textural properties or melting of cheese. In contrast, when calcium was injected, a decrease in cheese weight was observed that was manifested through syneresis. The moisture content and pH of the cheese decreased as well. Calcium injection also decreased the area of cheese matrix occupied by protein. Cheese hardness increased, and cohesiveness and melting of cheese decreased upon calcium injection. We concluded that adding calcium to cheese alters how the proteins interact, which is manifested as changes in cheese microstructure. Such changes in cheese structure provide an understanding of changes in functional attributes of the cheese. PMID:12613854

Pastorino, A J; Ricks, N P; Hansen, C L; McMahon, D J

2003-01-01

279

Improving the controlled release of water-insoluble emodin from amino-functionalized mesoporous silica  

International Nuclear Information System (INIS)

Several types of amino-functionalized mesoporous silica, including F5-SBA-15, F10-SBA-15, and F15-SBA-15 were prepared through co-condensation of tetraethoxysilane (TEOS) and (3-aminopropyl)triethoxysilane (APTES) in varying molar ratios (5 mol%, 10 mol%, and 15 mol%) via a hydrothermal process. The materials obtained were characterized by means of small-angle X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption-desorption, Fourier transformed infrared spectra, and X-ray photoelectron spectroscopy. Increasing APTES molar ratios decreased the degree of orderliness of the functionalized mesoporous silica. Pure and amino-functionalized SBA-15 samples were employed as supports for the controlled release of water-insoluble drug emodin. Loading experiments showed that drug loading capacities mainly depended on the surface areas and pore diameters of the carriers. Controlled release profiles of emodin-loaded samples were studied in phosphate buffered saline (PBS, pH 7.4), and results indicated that the emodin release rate could be controlled by surface amino-functionalized carriers. Emodin loaded on functionalized mesoporous supports exhibited a lower release rate than that of loaded on pure SBA-15, emodin loaded on F10-SBA-15 showed the smallest release amount (71.74 wt%) after stirring in PBS for 60 h. Findings suggest that functionalized mesoporous SBA-15 is a promising carrier for achieving prolonged release t carrier for achieving prolonged release time periods.

280

Improving the controlled release of water-insoluble emodin from amino-functionalized mesoporous silica  

Science.gov (United States)

Several types of amino-functionalized mesoporous silica, including F5-SBA-15, F10-SBA-15, and F15-SBA-15 were prepared through co-condensation of tetraethoxysilane (TEOS) and (3-aminopropyl)triethoxysilane (APTES) in varying molar ratios (5 mol%, 10 mol%, and 15 mol%) via a hydrothermal process. The materials obtained were characterized by means of small-angle X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption-desorption, Fourier transformed infrared spectra, and X-ray photoelectron spectroscopy. Increasing APTES molar ratios decreased the degree of orderliness of the functionalized mesoporous silica. Pure and amino-functionalized SBA-15 samples were employed as supports for the controlled release of water-insoluble drug emodin. Loading experiments showed that drug loading capacities mainly depended on the surface areas and pore diameters of the carriers. Controlled release profiles of emodin-loaded samples were studied in phosphate buffered saline (PBS, pH 7.4), and results indicated that the emodin release rate could be controlled by surface amino-functionalized carriers. Emodin loaded on functionalized mesoporous supports exhibited a lower release rate than that of loaded on pure SBA-15, emodin loaded on F10-SBA-15 showed the smallest release amount (71.74 wt%) after stirring in PBS for 60 h. Findings suggest that functionalized mesoporous SBA-15 is a promising carrier for achieving prolonged release time periods.

Xu, Yunqiang; Wang, Chunfeng; Zhou, Guowei; Wu, Yue; Chen, Jing

2012-06-01

281

Virtual water maze learning in human increases functional connectivity between posterior hippocampus and dorsal caudate.  

Science.gov (United States)

Recent work has demonstrated that functional connectivity between remote brain regions can be modulated by task learning or the performance of an already well-learned task. Here, we investigated the extent to which initial learning and stable performance of a spatial navigation task modulates functional connectivity between subregions of hippocampus and striatum. Subjects actively navigated through a virtual water maze environment and used visual cues to learn the position of a fixed spatial location. Resting-state functional magnetic resonance imaging scans were collected before and after virtual water maze navigation in two scan sessions conducted 1 week apart, with a behavior-only training session in between. There was a large significant reduction in the time taken to intercept the target location during scan session 1 and a small significant reduction during the behavior-only training session. No further reduction was observed during scan session 2. This indicates that scan session 1 represented initial learning and scan session 2 represented stable performance. We observed an increase in functional connectivity between left posterior hippocampus and left dorsal caudate that was specific to scan session 1. Importantly, the magnitude of the increase in functional connectivity was correlated with offline gains in task performance. Our findings suggest cooperative interaction occurs between posterior hippocampus and dorsal caudate during awake rest following the initial phase of spatial navigation learning. Furthermore, we speculate that the increase in functional connectivity observed during awake rest after initial learning might reflect consolidation-related processing. Hum Brain Mapp, 2014. © 2014 Wiley Periodicals, Inc. PMID:25418860

Woolley, Daniel G; Mantini, Dante; Coxon, James P; D'Hooge, Rudi; Swinnen, Stephan P; Wenderoth, Nicole

2014-11-21

282

Effects of Fault Displacement on Emplacement Drifts  

International Nuclear Information System (INIS)

The purpose of this analysis is to evaluate potential effects of fault displacement on emplacement drifts, including drip shields and waste packages emplaced in emplacement drifts. The output from this analysis not only provides data for the evaluation of long-term drift stability but also supports the Engineered Barrier System (EBS) process model report (PMR) and Disruptive Events Report currently under development. The primary scope of this analysis includes (1) examining fault displacement effects in terms of induced stresses and displacements in the rock mass surrounding an emplacement drift and (2 ) predicting fault displacement effects on the drip shield and waste package. The magnitude of the fault displacement analyzed in this analysis bounds the mean fault displacement corresponding to an annual frequency of exceedance of 10-5 adopted for the preclosure period of the repository and also supports the postclosure performance assessment. This analysis is performed following the development plan prepared for analyzing effects of fault displacement on emplacement drifts (CRWMS M and O 2000). The analysis will begin with the identification and preparation of requirements, criteria, and inputs. A literature survey on accommodating fault displacements encountered in underground structures such as buried oil and gas pipelines will be conducted. For a given fault displacement, the least favorable scenario in term of the spatial relation of a fault to an emplacement drift is chosen, and the analysis is then performed analytically. Based on the analysis results, conclusions are made regarding the effects and consequences of fault displacement on emplacement drifts. Specifically, the analysis will discuss loads which can be induced by fault displacement on emplacement drifts, drip shield and/or waste packages during the time period of postclosure

283

Surface displacement and hydraulic connectivity in Bangkok plain inferred from persistent scatterer interferometry  

Science.gov (United States)

Land subsidence induced by the compaction of overdrafted aquifer systems have occurred in a lot of cities all over the world and have induced severe damage to buildings and infrastructures. In recent decades, some cities have taken measures to mitigate severe ground subsidence caused by groundwater extraction by, for instance, implementing artificial water injection schemes or regulating groundwater pumping, and surface rebound in these regions has been reported. Previously, SAR interferometry and persistent scatterer interferometry (PSI) has been successfully used as a monitoring tool for the uplifting event and we can also use the data to infer the extension of unrecognized fault and geological boundary as well as the elastic property of the aquifer. In this study, we first estimated recent ground displacement by using PSI analysis of ALOS/PALSAR images obtained during November 2007 and December 2010, focusing on the Bangkok, the capital city of Thailand. In this region, ground subsidence due to excessive groundwater pumping had been reported previously, however, we detected ground uplift from 0.5 to 3.0 cm during ALOS observation period. The estimated displacement time-series are consistent with those obtained from surface settlement measurement points in monitoring wells. Since groundwater usage has decreased in Bangkok due to the regulation of groundwater pumping, and groundwater level at productive aquifer has been rising at the estimated uplift area after the regulation, this uplift can be attributed to the increase in the hydraulic head due to the preceding depression in pore pressure. And then, we estimated the lateral connectivity of aquifer as well as the aquifer elastic properties using a temporal model. We considered seasonal factor by a sinusoidal function with a period of one year, and the non-seasonal factor by an exponential function. As a result, we found that non-seasonal uplift occurred uniformly over the whole area at the rate of 0.5-1.5 cm/year, whereas seasonal displacement was not found in all areas, and the time shift of the seasonal displacement differed even in those areas where it occurred. This result demonstrates lateral hydraulic connectivity within individual aquifers of the multi-aquifer system under the Bangkok plain. Moreover, the magnitude of the decay coefficient of the exponential function describing the secular uplift might reflect floodplain changes or the subsidence history. Our results demonstrate that the temporal model interpretation would be useful to investigate aquifer structure which cannot be easily inferred.

Ishitsuka, K.; Fukushima, Y.; Tsuji, T.; Yamada, Y.; Matsuoka, T.

2013-12-01

284

The Prediction of Plant Functional Diversity in Water-Limited Ecosystems  

Science.gov (United States)

This modeling study explores the relationships between seasonal precipitation patterns, physiological and morphological plant adaptations and plant functional diversity in arid and semi-arid ecosystems. At the basis of the study is a hydraulic soil-plant model that simulates photosynthetic carbon gain under water-limited conditions. Soil in the model is structured into two layers, with spring-summer precipitation assumed to recharge only the shallow soil layer and fall-winter precipitation recharging the deeper soil layer. Plants in the model are characterized primarily through the allocation of total biomass between roots and shoots and the allocation of root biomass between the two soil layers. Photosynthetic carbon gain is linked to plant water uptake through a photosynthesis model for C3 plants. Inherent in this model is a tradeoff between the capacity for water uptake from the shallow and the deeper soil layers, thus the use of warm-season and cold-season derived precipitation. Traits that facilitate the uptake of shallow soil moisture include a low root/shoot ratio and a predominantly shallow root system, while traits that facilitate the uptake of deeper soil moisture include a higher root/shoot ratio and a predominantly deep root system. Based on this tradeoff, we derived phenotypes that are optimally adapted to specific precipitation regimes, though maximizing plant carbon gain over a period of time. The result is an array of reasonably realistic "plant functional types", defined by the precipitation condition that selected them. We further show that diverse arrays of plant functional types, competing for soil moisture, form stable communities, but that seasonal precipitation distribution determines which functional type(s) become dominant.

Schwinning, S.; Ehleringer, J. R.

2001-12-01

285

Ecosystem function in waste stabilisation ponds: Improving water quality through a better understanding of biophysical coupling  

Science.gov (United States)

Wastewater stabilisation ponds (WSPs) are highly productive systems designed to treat wastewater using only natural biological and chemical processes. Phytoplankton, microbial communities and hydraulics play important roles for ecosystem functionality of these pond systems. Although WSPs have been used for many decades, they are still considered as 'black box' systems as very little is known about the fundamental ecological processes which occur within them. However, a better understanding of how these highly productive ecosystems function is particularly important for hydrological processes, as treated wastewater is commonly discharged into streams, rivers, and oceans, and subject to strict water quality guidelines. WSPs are known to operate at different levels of efficiency, and treatment efficiency of WSPs is dependent on physical (flow characteristics and sludge accumulation and distribution) and biological (microbial and phytoplankton communities) characteristics. Thus, it is important to gain a better understanding of the role and influence of pond hydraulics and vital microbial communities on pond performance and WSP functional stability. The main aim of this study is to investigate the processes leading to differences in treatment performance of WSPs. This study uses a novel and innovative approach to understand these factors by combining flow cytometry and metabolomics to investigate various biochemical characteristics, including the metabolite composition and microbial community within WSPs. The results of these analyses will then be combined with results from the characterisation of pond hydrodynamics and hydraulic performance, which will be performed using advanced hydrodynamic modelling and advanced sludge profiling technology. By understanding how hydrodynamic and biological processes influence each other and ecosystem function and stability in WSPs, we will be able to propose ways to improve the quality of the treatment using natural processes, with less reliance on chemical treatment. This will in turn contribute to the reduction in the cost of operation, but more importantly reduce the impact on the environment (i.e., discharge, GHGs), and increase water quality and the potential for water reuse worldwide.

Ghadouani, Anas; Reichwaldt, Elke S.; Coggins, Liah X.; Ivey, Gregory N.; Ghisalberti, Marco; Zhou, Wenxu; Laurion, Isabelle; Chua, Andrew

2014-05-01

286

Polybenzoxazole via aromatic nucleophilic displacement  

Science.gov (United States)

Polybenzoxazoles (PBO) are heterocyclic macromolecules which were first synthesized in a two-step process by the initial formation of aromatic diacid chlorides with bis(o-aminophenol)s through solution condensation of aromatic diacid chlorides with bis(o-aminophenol)s followed by thermal cyclodehydration. Since then several methods were utilized in their synthesis. The most common synthetic method for PBO involves a polycondensation of bis(o-aminophenol)s with aromatic diacid diphenyl esters. Another preparative route involves the solution polycondensation of the hydrochloride salts of bis(o-amino phenol)s with aromatic diacids in polyphosphoric acid. Another synthetic method involves the initial formation of poly(o-hydroxy amide)s from silylated bis(o-aminophenol)s with aromatic diacid chlorides followed by thermal cyclodehydration to PBO. A recent preparative route involves the reaction of aromatic bisphenols with bis(fluorophenyl) benzoxazoles by the displacement reaction to form PBO. The novelty of the present invention is that high molecular weight PBO of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

Hergenrother, Paul M. (inventor); Connell, John W. (inventor); Smith, Joseph G., Jr. (inventor)

1993-01-01

287

Water  

Science.gov (United States)

... it tested. You cannot see, taste, or smell lead in drinking water. Therefore, you must ask your water provider whether ... can also reduce or eliminate your exposure to lead in drinking water by consuming only bottled water or water from ...

288

Video Games, Adolescents, and the Displacement Effect  

Science.gov (United States)

The displacement effect (the idea that time spent in one activity displaces time spent in other activities) was examined within the lens of adolescents' video game use and their time spent reading, doing homework, in physically active sports and activities, in creative play, and with parents and friends. Data were drawn from the Panel Study…

Fisher, Carla Christine

2012-01-01

289

Unusual renal displacement due to massive splenomegaly  

International Nuclear Information System (INIS)

Report of a case of unusual renal displacement due to massive splenomegaly. The left kidney was displaced upwards by massive enlargement of the spleen. The own findings of ultrasonography, abdominal computed tomography and intravenous urogram are described and compared with the findings in the literature. (orig.)

290

Displacement and Knowledge Construction in Literature Reviews.  

Science.gov (United States)

Two literature reviews are interpreted to demonstrate how they are informed by what the author labels the "displacement story," that is, a story of how one prevailing professional paradigm is replaced by another. This study demonstrates how the narration, structure, and language in each review render particular tellings of the displacement story.…

Steinley, Gary

291

Biaxial laser-based displacement transducer  

Science.gov (United States)

A simple laser-based instrument is described which produces output voltages proportional to displacements in orthogonal directions. This instrument and the associated experimental techniques have been used to measure biaxial displacements across 400-micron slots at various angles in sheet specimens of various widths.

Sharpe, W. N., Jr.; Payne, T. S.; Smith, M. K.

1978-01-01

292

Analysis by radiochemical displacement: determination of EDTA  

International Nuclear Information System (INIS)

A new radiochemical displacement method was developed for the determination of EDTA. The displacement of labelled zinc from Zn:PAN complex by EDTA at pH 5.5 in borate buffers can be conveniently utilized for the determination of 50-150 ?g of EDTA. Effects of diverse ions on the determination were also tested. (author)

293

Analysis by radiochemical displacement : determination of EDTA  

International Nuclear Information System (INIS)

A new radiochemical displacement method has been developed for the determination of EDTA. The displacement of labelled zinc from Zn:PAN complex by EDTA at pH 5.5 in borate buffers can be conveniently utilised for the determination of 50 - 150 ?g of EDTA. (author)

294

Analysis by radiochemical displacement: determination of EDTA  

Energy Technology Data Exchange (ETDEWEB)

A new radiochemical displacement method was developed for the determination of EDTA. The displacement of labelled zinc from Zn:PAN complex by EDTA at pH 5.5 in borate buffers can be conveniently utilized for the determination of 50-150 g of EDTA. Effects of diverse ions on the determination were also tested. 5 refs.

Sivamoorthy, V.; Varma, K.V.; Muralikrishna, K.V.; Rangamannar, B.

1987-02-16

295

Hydrated goethite (alpha-FeOOH) (100) interface structure: Ordered water and surface functional groups.  

Energy Technology Data Exchange (ETDEWEB)

Goethite({alpha}-FeOOH), an abundant and highly reactive iron oxyhydroxide mineral, has been the subject of numerous stud-ies of environmental interface reactivity. However, such studies have been hampered by the lack of experimental constraints on aqueous interface structure, and especially of the surface water molecular arrangements. Structural information of this type is crucial because reactivity is dictated by the nature of the surface functional groups and the structure or distribution of water and electrolyte at the solid-solution interface. In this study we have investigated the goethite(100) surface using surface diffraction techniques, and have determined the relaxed surface structure, the surface functional groups, and the three dimensional nature of two distinct sorbed water layers. The crystal truncation rod (CTR) results show that the interface structure consists of a double hydroxyl, double water terminated interface with significant atom relaxations. Further, the double hydroxyl terminated surface dominates with an 89% contribution having a chiral subdomain structure on the(100) cleavage faces. The proposed interface stoichiometry is ((H{sub 2}O)-(H{sub 2}O)-OH{sub 2}-OH-Fe-O-O-Fe-R) with two types of terminal hydroxyls; a bidentate (B-type) hydroxo group and a monodentate (A-type) aquo group. Using the bond-valence approach the protonation states of the terminal hydroxyls are predicted to be OH type (bidentate hydroxyl with oxygen coupled to two Fe{sup 3+} ions) and OH{sub 2} type (monodentate hydroxyl with oxygen tied to only one Fe{sup 3+}). A double layer three dimensional ordered water structure at the interface was determined from refinement of fits to the experimental data. Application of bond-valence constraints to the terminal hydroxyls with appropriate rotation of the water dipole moments allowed a plausible dipole orientation model as predicted. The structural results are discussed in terms of protonation and H-bonding at the interface, and the results provide an ideal basis for testing theoretical predictions of characteristic surface properties such as pK{sub a}, sorption equilibria, and surface water permittivity.

Ghose, S.K.; Waychunas, G.A.; Trainor, T.P.; Eng, P.J.

2009-12-15

296

Solvent isotope effects on nucleophilic displacement reactions  

International Nuclear Information System (INIS)

The kinetic solvent isotope effect, KSIE, (k/sub H2O//k/sub D2O/), at 25.00C and ionic strength, I, equal to 0.20 +- 0.02 M was measured for the nucleophilic displacement of iodine ion from iodomethane, iodoacetamide, and iodoacetate ion, thiophene from S-Methylthiophenium ion, and tosylate ion from methyl tosylate by bromide ion, chloride ion, acetate ion, hydroxide ion, water, ammonia, ethylenediamine, n-butylamine, piperazine, piperidine, quinuclidine, and 1,4-Diazabicyclo[2.2.2]octane (DABCO), and the monoprotonated cations of ethylenediamine, piperazine, and DABCO. By means of solvent partition measurements at 25.00C and I = 0.02 M between H2O and D2O and a common immiscible organic solvent, the ground state activity coefficients in D2O, the solution in H2O being chosen as the reference state, were determined for the nitrogen-containing nucleophiles (except ammonia) and the substrates methyl tosylate, iodoacetamide, and iodoacetic acid. The solubilities at 25.00C of the picrate and tetraphenylborate salts of the monoprotonated cationic forms of ethylenediamine, piperazine, and DABCO were measured to determine the activity coefficients in D2O of these ions relative to an H2O reference state. Applying the Eyring equation, the activity coefficients of the transition states in D2O, reference state H2O, were calculatede H2O, were calculated

297

Impact of water saturation on seismoelectric transfer functions: a laboratory study of coseismic phenomenon  

Science.gov (United States)

Seismic waves propagating in a porous medium, under favourable conditions, generate measurable electromagnetic fields due to electrokinetic effects. It has been proposed, following experimental and numerical studies, that these so-called `seismoelectromagnetic' couplings depend on pore fluid properties. The theoretical frame describing these phenomena are based on the original Biot's theory, assuming that pores are fluid-filled. We study here the impact of a partially saturated medium on amplitudes of those seismoelectric couplings by comparing experimental data to an effective fluid model. We have built a 1-m-length-scale experiment designed for imbibition and drainage of an homogeneous silica sand; the experimental set-up includes a seismic source, accelerometers, electric dipoles and capacitance probes in order to monitor seismic and seismoelectric fields during water saturation. Apparent velocities and frequency spectra (in the kiloHertz range) are derived from seismic and electrical measurements during experiments in varying saturation conditions. Amplitudes of seismic and seismoelectric waves and their ratios (i.e. transfer functions) are discussed using a spectral analysis performed by continuous wavelet transform. The experiments reveal that amplitude ratios of seismic to coseismic electric signals remain rather constant as a function of the water saturation in the Sw = [0.2-0.9] range, consistently with theoretically predicted transfer functions.

Bordes, C.; Sénéchal, P.; Barrière, J.; Brito, D.; Normandin, E.; Jougnot, D.

2015-03-01

298

Universal scaling of potential energy functions describing intermolecular interactions. II. The halide-water and alkali metal-water interactions  

Energy Technology Data Exchange (ETDEWEB)

The scaled forms of the newly introduced generalized potential energy functions (PEFs) describing intermolecular interactions [J. Chem. Phys. xx, yyyyy (2011)] have been used to fit the ab-initio minimum energy paths (MEPs) for the halide- and alkali metal-water systems X-(H2O), X=F, Cl, Br, I, and M+(H2O), M=Li, Na, K, Rb, Cs. These generalized forms produce fits to the ab-initio data that are between one and two orders of magnitude better in the ?2 than the original forms of the PEFs. They were found to describe both the long-range, minimum and repulsive wall of the potential energy surface quite well. Overall the 4-parameter extended Morse (eM) and generalized Buckingham exponential-6 (gB-e6) potentials were found to best fit the ab-initio data. Furthermore, a single set of parameters of the reduced form was found to describe all candidates within each class of interactions. The fact that in reduced coordinates a whole class of interactions can be represented by a single PEF, yields the simple relationship between the molecular parameters associated with energy (well depth, ?), structure (equilibrium distance, rm) and spectroscopy (anharmonic frequency, ?):€? = A? (? /?)1/ 2 /rm + B?? /rm 3 , where A and B are constants depending on the underlying PEF. This more general case of Badger’s rule has been validated using the experimentally measured frequencies of the hydrogen bonded OH stretching vibrations in the halide-water series.

Werhahn, Jasper C.; Akase, Dai; Xantheas, Sotiris S.

2014-08-14

299

Photochemical degradation of phenanthrene as a function of natural water variables modeling freshwater to marine environments  

International Nuclear Information System (INIS)

Photolysis rates of phenanthrene as a function of ionic strength (salinity), oxygen levels and humic acid concentrations were measured in aqueous solution over the range of conditions found in fresh to marine waters. Photolysis followed first order kinetics, with an estimated photodegradation half-life in sunlight in pure water of 10.3 ± 0.7 h, in the mid-range of published results. Photolysis rate constants decreased by a factor of 5 in solutions with humic acid concentrations from 0 to 10 mg C L?1. This decrease could be modeled entirely based on competitive light absorption effects due to the added humics. No significant ionic strength or oxygen effects were observed, consistent with a direct photolysis mechanism. In the absence of significant solution medium effects, the photodegradation lifetime of phenanthrene will depend only on solar fluxes (i.e. temporal and seasonal changes in sunlight) and not vary with a freshwater to marine environment.

300

Targeted functionalization of porous materials for separation of alcohol/water mixtures by modular assembly.  

Science.gov (United States)

Three isoreticular hydrogen-bonded frameworks with functionalized pore structures were constructed by a modular self-assembly process in which a series of amino acids with various substituents serve as facile exchange subassemblies to decorate the pore wall. The ordered amino acid side-chain groups in the pore channels play an important role in determining the adsorption behavior of the framework materials, and ensure exclusive adsorption of methanol/water over ethanol. Gas-chromatographic separation experiments demonstrated that alcohols can be efficiently separated from ternary water/methanol/ethanol mixtures and revealed a key influence of the adsorbate-host framework interaction on the practical separation performance of mixtures. PMID:25234745

Ren, Cai-Xia; Ji, Min; Yao, Qing-Xia; Cai, Li-Xuan; Tan, Bin; Zhang, Jie

2014-11-01

301

Water plasma functionalized CNTs/MnO2 composites for supercapacitors.  

Science.gov (United States)

A water plasma treatment applied to vertically-aligned multiwall carbon nanotubes (CNTs) synthesized by plasma enhanced chemical vapour deposition gives rise to surface functionalization and purification of the CNTs, along with an improvement of their electrochemical properties. Additional increase of their charge storage capability is achieved by anodic deposition of manganese dioxide lining the surface of plasma-treated nanotubes. The morphology (nanoflower, layer, or needle-like structure) and oxidation state of manganese oxide depend on the voltage window applied during charge-discharge measurements and are found to be key points for improved efficiency of capacitor devices. MnO2/CNTs nanocomposites exhibit an increase in their specific capacitance from 678?Fg(-1), for untreated CNTs, up to 750?Fg(-1), for water plasma-treated CNTs. PMID:24348189

Hussain, Shahzad; Amade, Roger; Jover, Eric; Bertran, Enric

2013-01-01

302

Bio-functionalized water-soluble ZnS quantum dots using carboxymethylchitosan  

Science.gov (United States)

The major goal of this study was to develop an innovative green route for synthesizing biocompatible water-soluble luminescent QDs using chemically modified chitosan as the ligand in aqueous media. The preparation of ZnS QDs bio-functionalized by carboxymethylchitosan (CMC) was performed using a single-step aqueous colloidal process at room temperature. The results showed that water-dispersible ZnS nanocrystals capped by CMC were produced within the quantum-size confinement regime. Moreover, the luminescent properties of ZnS QDs were significantly affected by the pH during the synthesis due to the size distribution of the nanoparticles and their density of surface states.

Mansur, A. A. P.; Mansur, H. S.; Borsagli, F. G. L. M.; Ramanery, F. P.

2015-03-01

303

The role of continuous and discrete water structures in protein function  

Science.gov (United States)

Proteins have evolved to perform numerous roles as specific catalysts and nano-machines. Some of the mechanisms exploited by evolution are clear. Hydrophobicity drives the stabilization energy of folding, charges mediate long-range interactions and facilitate catalysis, and specific geometries and hydrogen bonding patterns facilitate molecular recognition and catalysis. In this work, we examine the energy landscape of protein dynamics in terms of the continuous and discrete water structures that control protein dynamics. We observe that the internal structures at the active site of proteins are constantly shaped by strong interactions with hydration shell and bulk water motions. By describing the energy landscape of proteins in terms of its three component motions; conformational, hydration and protonation, and electronic structure, it is possible to systematically understand protein function.

McMahon, Benjamin H.; Frauenfelder, Hans; Fenimore, Paul W.

2014-04-01

304

Present Situation Research on Axial Flow Displacement Theory During Cementing  

OpenAIRE

It is well known that displacing drilling fluid effectively is the premise to obtain good cementing quality. During cementing axial flow is the major way to displace annular drilling fluid. So we put emphasis on the research of axial flow displacement theory. At present axial flow displacement theory mainly focuses on three aspects: displacement theory study based on wall shear stress; displacement theory study based on the numerical simulation technique for the displacement interface stabili...

Ai, Chi; Yu Fahao; Feng, Fuping; Chen, Dingfeng; Wei, Ting

2014-01-01

305

Water adsorption on clay minerals as a function of relative humidity: application of BET and Freundlich adsorption models.  

Science.gov (United States)

Water adsorption on kaolinite, illite, and montmorillonite clays was studied as a function of relative humidity (RH) at room temperature (298 K) using horizontal attenuated total reflectance (HATR) Fourier transform infrared (FTIR) spectroscopy equipped with a flow cell. The water content as a function of RH was modeled using the Brunauer, Emmett, and Teller (BET) and Freundlich adsorption isotherm models to provide complementary multilayer adsorption analysis of water uptake on the clays. A detailed analysis of model fit integrity is reported. From the BET fit to the experimental data, the water content on each of the three clays at monolayer (ML) water coverage was determined and found to agree with previously reported gravimetric data. However, BET analysis failed to adequately describe adsorption phenomena at RH values greater than 80%, 50%, and 70% RH for kaolinite, illite, and montmorillonite clays, respectively. The Freundlich adsorption model was found to fit the data well over the entire range of RH values studied and revealed two distinct water adsorption regimes. Data obtained from the Freundlich model showed that montmorillonite has the highest water adsorption strength and highest adsorption capacity at RH values greater than 19% (i.e., above ML water adsorption) relative to the kaolinite and illite clays. The difference in the observed water adsorption behavior between the three clays was attributed to different water uptake mechanisms based on a distribution of available adsorption sites. It is suggested that different properties drive water adsorption under different adsorption regimes resulting in the broad variability of water uptake mechanisms. PMID:22181675

Hatch, Courtney D; Wiese, Jadon S; Crane, Cameron C; Harris, Kenneth J; Kloss, Hannah G; Baltrusaitis, Jonas

2012-01-24

306

Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO  

Science.gov (United States)

Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisations usually rely on a set of lookup tables and (pedo)transfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved. Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42). Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = -0.26) due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72). Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is probably more important than the estimation of water flow parameters. Overall, the results are encouraging for the use of this modelling set-up to estimate pesticide leaching risks at the regional-scale, especially where the objective is to identify vulnerable soils and "source" areas of contamination.

Moeys, J.; Larsbo, M.; Bergström, L.; Brown, C. D.; Coquet, Y.; Jarvis, N. J.

2012-07-01

307

Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO  

Directory of Open Access Journals (Sweden)

Full Text Available Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisation usually rely on a set of lookup tables and (pedotransfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved.

Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42. Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = ?0.26 due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72. Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is probably more important than the estimation of water flow parameters. Overall, the results are encouraging for the use of this modelling set-up to estimate pesticide leaching risks at the regional-scale, especially where the objective is to identify vulnerable soils and "source" areas of contamination.

J. Moeys

2012-02-01

308

Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO  

Directory of Open Access Journals (Sweden)

Full Text Available Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisations usually rely on a set of lookup tables and (pedotransfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved.

Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42. Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = ?0.26 due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72. Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is probably more important than the estimation of water flow parameters. Overall, the results are encouraging for the use of this modelling set-up to estimate pesticide leaching risks at the regional-scale, especially where the objective is to identify vulnerable soils and "source" areas of contamination.

J. Moeys

2012-07-01

309

Identification of elastic parameters by displacement field measurement  

OpenAIRE

In this Note we study a parameter identification problem associated with a two-dimensional mechanical problem. In a first part, the experimental technique of determining the displacement field is presented. The variational method proposed herein is based on the minimization of a separately convex functional which leads to the reconstruction of the elastic tensor and the stress field. These two reconstructed fields are continuous and piecewise linear on a triangulation of the two-dimensional p...

Geymonat, Giuseppe; Hild, Franc?ois; Pagano, Ste?phane

2002-01-01

310

Displaced proximal humeral fractures: an Indian experience with locking plates  

OpenAIRE

Abstract Background The treatment of displaced proximal humerus fractures, especially in elderly, remains controversial. The objective of this study was to evaluate functional outcome of locking plate used for fixation of these fractures after open reduction. We also attempted to evaluate the complications and predictors of loss of fixation for such an implant. Methods Over two and a half years, 56 patients with an acute proximal humerus fracture were managed with locking plate osteosynthesis...

Aggarwal Sameer; Bali Kamal; Dhillon Mandeep S; Kumar Vishal; Mootha Aditya K

2010-01-01

311

Silicon Application Increases Drought Tolerance of Kentucky Bluegrass by Improving Plant Water Relations and Morphophysiological Functions  

OpenAIRE

Drought stress encumbers the growth of turfgrass principally by disrupting the plant-water relations and physiological functions. The present study was carried out to appraise the role of silicon (Si) in improving the drought tolerance in Kentucky bluegrass (Poa pratensis L.). Drought stress and four levels (0, 200, 400, and 800?mg?L?1) of Si (Na2SiO3·9H2O) were imposed after 2 months old plants cultured under glasshouse conditions. Drought stress was found to decrease the photosynthes...

Shah Saud; Xin Li; Yang Chen; Lu Zhang; Shah Fahad; Saddam Hussain; Arooj Sadiq; Yajun Chen

2014-01-01

312

Simple functions for fast calculations of selected thermodynamic properties of the ammonia-water system  

Energy Technology Data Exchange (ETDEWEB)

A set of five equations describing vapour-liquid equilibrium properties of the ammonia - water system is presented. They are intended for use in the design of absorption processes. Using variable dependences of technical relevance the equations make it possible to avoid iterative evaluations. The equations were constructed by fitting critically assessed experimental data using simple functional forms. They cover the region within which absorption cycles commonly used operate most often. The enthalpy of the gas phase has been calculated in the ideal mixture approximation. The results are presented in the form of an enthalpy-concentration diagram. (author)

Patek, J.; Klomfar, J. [Ceskoslovenska Akademie Ved, Prague (Czech Republic). Ustav Termomechaniky

1995-05-01

313

Fluorescence quantum yield of cresyl violet in methanol and water as a function of concentration  

Energy Technology Data Exchange (ETDEWEB)

Photothermal spectroscopies and fluorimetry have been used to determine absolute and relative fluorescence quantum yields for cresyl violet perchlorate in methanolic and aqueous solutions as a function of concentration. The concentration dependence of the fluorescence quantum yield is found to be significant and cannot be ignored as in past studies. The values of the fluorescence quantum yield are found to be affected by inner filter effects. In aqueous solution, the fluorescence quantum yield is also affected by quenching attributable to water structure and dye dimerization. 51 refs., 7 figs., 1 tab.

Isak, S.J.; Eyring, E.M. [Univ. of Utah, Salt Lake City, UT (United States)

1992-02-20

314

Aryl-derivatized, water-soluble functionalized carbon nanotubes for biomedical applications  

International Nuclear Information System (INIS)

The functionalization of very-thin multi-walled carbon nanotubes (VT-MWNTs) with an aniline derivative, via the protocol of in situ generated aryl diazonium salts results, upon acidic deprotection of the terminal BOC group, on the formation of the water-soluble positively charged ammonium functionalized VT-MWNTs-NH3+ material. The new materials have been structurally and morphologically characterized by infra-red (ATR-IR) spectroscopy and transmission electron microscopy (TEM). The quantitative calculation of the grafted aryl units onto the skeleton of VT-MWNTs has been estimated by thermogravimetric analysis (TGA), while the quantitative Kaiser test showed the amine group loaded onto VT-MWNTs-NH3+ material. The aqueous solubility of this material has allowed the performance of some initial toxicological in vitro investigations

315

Effects of threshold displacement energy on defect production by displacement cascades in ?, ? and ?-LiAlO2  

International Nuclear Information System (INIS)

Threshold displacement energy evaluation and a series of displacement cascade simulations in ?, ?, and ?-LiAlO2 were performed using molecular dynamics. Threshold displacement energy evaluations indicated that higher absolute ionic charge values and larger densities both increase threshold displacement energy. The displacement cascade simulations suggest that the influence of different crystal structures on the number of interstitial atoms generated in a displacement cascade is explainable almost entirely by the difference of the threshold displacement energy

316

Crossover from Fingering to Fracturing in Fluid-fluid Displacement in Deformable Granular Media: Theory and Experiments  

Science.gov (United States)

Predicting and, possibly, controlling the morphology of gas invasion in porous media is critical in many natural and engineered processes like enhanced oil recovery, hydraulic fracturing, methane venting from organic-rich sediments, and filter design. Here, we study fluid-fluid displacement in a deformable granular medium by means of laboratory experiments, computer simulations and scaling analysis. Experimentally, we inject air into a water-saturated glass beads packed in a slender cylindrical container, and record the evolution of the invasion pattern. We have three control variables: the injection rate, the bead size, and the confining stress. Under large confinement, when the granular pack behaves as a rigid medium, the invasion pattern experiences a transition from viscous to capillary fingering by decreasing the injection rate, in agreement with classical results [1]. We show, however, that for a fixed injection rate the system exhibits a crossover from fingering to "fracturing" as the bead size is decreased or the level of confinement is reduced. Thus, fracture opening is the dominant gas invasion mechanism in fine, soft sediments. Our mechanistic model and scaling analysis allow us to rationalize the different regimes of fluid displacement as a function of the properties of the fluids (interfacial tension and viscosity) and solid particles (particle size and stiffness), pore-scale disorder, injection rate and external confinement. We identify two dimensionless groups that describe the interplay between capillarity, viscosity and elasticity, and control the mode of fluid displacement [2].

Holtzman, R.; Szulczewski, M.; Darby, J.; Juanes, R.

2011-12-01

317

Functions of the water soluble chlorophyll-binding protein in plants.  

Science.gov (United States)

Functional aspects of water soluble chlorophyll-binding protein (WSCP) in plants were investigated during the courses of leaf senescence, chlorophyll biogenesis, stress response and photoprotection. The cDNA sequence encoding WSCP from cauliflower was cloned into a binary vector to facilitate Agrobacterium tumefaciens mediated transformation of Nicotiana tabacum. The resultant transgenic tobacco plants overexpressed the CauWSCP gene under the control of a 35S-promoter. Analyses of protein and pigment contents indicate that WSCP overexpression does not enhance chlorophyll catabolism in vivo, thus rendering a role of WSCP in Chl degradation unlikely. Accumulation of higher levels of protochlorophyllide in WSCP overexpressor plants corroborates a proposed temporary storage and carrier function of WSCP for chlorophyll and late precursors. Although WSCP overexpressor plants did not show significant differences in non-photochemical quenching of chlorophyll fluorescence, they are characterized by significantly lower zeaxanthin accumulation and peroxidase activity at different light intensities, even at high light intensities of 700-900?mol photons m(-2)s(-1). These results suggest a photoprotective function of the functional chlorophyll binding-WSCP tetramer by shielding of chlorophylls from molecular oxygen. PMID:21481489

Damaraju, Sridevi; Schlede, Stephanie; Eckhardt, Ulrich; Lokstein, Heiko; Grimm, Bernhard

2011-08-15

318

A significant enhancement of water vapour uptake at low pressure by amine-functionalization of UiO-67.  

Science.gov (United States)

The functionalization of UiO-67 with -NH2 groups enhances CO2 and CH4 adsorption at 1 bar and 298 K and positively influences the framework's interaction with water as evidenced by the significant enhancement of water vapour adsorption at 0.1 < P/P0 < 0.3 and 298 K. PMID:25519009

Ko, Nakeun; Hong, Jisu; Sung, Siyoung; Cordova, Kyle E; Park, Hye Jeong; Yang, Jin Kuk; Kim, Jaheon

2015-02-01

319

Experimental validation of a numerical model of two-phase displacement in porous medium  

International Nuclear Information System (INIS)

Burial in geological layers appears to be an interesting solution to dispose of radioactive wastes. This thesis analyzes and simulates the behaviour of gas produced by waste barrels corrosion. The released contaminated gas drains the water initially present in the host rock and yields a water-gas two phase flow. A literature survey of two phase flow shows that fluid interfaces may display instabilities for definite flow characteristics. When the displacement is stable a smooth interface proceeds through the porous medium. When the interface shows fingering, the displacement is said to be 'viscous-unstable', and when the front is jagged the displacement is called 'capillary' displacement. A dimensional analysis of classical equations governing two phase flow in porous media is combined with a classification of dominant forces to define an original map of flow regimes that includes gravitational forces. The map is based on three dimensionless numbers and predicts a priori the flow type. For typical data describing a radioactive waste repository a 'viscous-unstable' displacement is predicted by the map. We simulate water-gas displacement with a numerical model previously developed; this code, based on the Muskat model, uses the mixed-hybrid finite elements technique and is therefore well adapted for tracking moving interfaces. Fluxes are well conserved, however instabilities cannot be simulated. We assume that there is always a scale to be found where instabilities can bcale to be found where instabilities can be averaged and we try to validate the model with experimental two phase flows. We performed laboratory water-gas flow experiments for a variety of flow conditions. The observed displacement types are consistent with the map of flow regimes. Good agreement with numerical simulations is obtained when precise parameters of the displacements are available, in particular relative permeability curves. We conclude that our model allows a first approach of migration of gas near a radioactive waste repository and we present an example of a numerical simulation of a fictitious repository site. (author)

320

Extraction of atom-atom bridge and direct correlation functions from molecular simulations: A test for ambient water  

Science.gov (United States)

We compute partial structure factors for SPC/E water under ambient conditions, using radial distribution functions derived from simulations and employing finite-size corrections. We calculate atom-atom direct correlation functions by an inverse solution to reference interaction site model integral equations with account of long-range asymptotics of the functions as additional constraints. We split the short- and long-range contributions to the direct functions in the Ewald type manner. Finally we reconstruct atom-atom bridge functions. The obtained direct correlation functions are compared with the data obtained by the hypernetted chain approximation.

Chuev, Gennady N.; Vyalov, I.; Georgi, N.

2013-03-01

321

Comparison of Geophysical Model Functions for SAR Wind Speed Retrieval in Japanese Coastal Waters  

DEFF Research Database (Denmark)

This work discusses the accuracies of geophysical model functions (GMFs) for retrieval of sea surface wind speed from satellite-borne Synthetic Aperture Radar (SAR) images in Japanese coastal waters characterized by short fetches and variable atmospheric stability conditions. In situ observations from two validation sites, Hiratsuka and Shirahama, are used for comparison of the retrieved sea surface wind speeds using CMOD (C-band model)4, CMOD_IFR2, CMOD5 and CMOD5.N. Of all the geophysical model functions (GMFs), the latest C-band GMF, CMOD5.N, has the smallest bias and root mean square error at both sites. All of the GMFs exhibit a negative bias in the retrieved wind speed. In order to understand the reason for this bias, all SAR-retrieved wind speeds are separated into two categories: onshore wind (blowing from sea to land) and offshore wind (blowing from land to sea). Only offshore winds were found to exhibit the large negative bias, and short fetches from the coastline may be a possible reason for this. Moreover, it is clarified that in both the unstable and stable conditions, CMOD5.N has atmospheric stability effectiveness, and can keep the same accuracy with CMOD5 in the neutral condition. In short, at the moment, CMOD5.N is thought to be the most promising GMF for the SAR wind speed retrieval with the atmospheric stability correction in Japanese coastal waters, although there is ample room for future improvement for the effect from short fetch.

Takeyama, Yuko; Ohsawa, Teruo

2013-01-01

322

Dielectric constant and density of water as a function of pressure at constant temperature  

Scientific Electronic Library Online (English)

Full Text Available In order to simulate the effects of hydrostatic pressure on protein folding/unfolding it is necessary to accurately describe the behavior of the dielectric constant and the density of the solvent (water), in the range of pressures (between 0.1 MPa and 2.0 GPa) and temperatures (below 75 ° C) require [...] d for pressure-induced unfolding. A simple equation of the form X = X (T, Pi) + a0 ln (a i+ P)/(a i + Pi) [were X is the property, Pi (in MPa) is the reference pressure and a i are coefficients adjusted to fit experimental values] is proposed to describe both properties as function of pressure, at constant temperatures. The equation reproduces available data for dielectric constant and density of water to an accuracy of 0.1%. Because of its simplicity and accuracy, the proposed equation is useful for simulation studies and for any other problem where the knowledge of those properties as a function of pressure is needed.

Wely Brasil, Floriano; Marco Antonio Chaer, Nascimento.

2004-03-01

323

Recovery of functional materials with thermally stable antioxidative properties in squid muscle hydrolyzates by subcritical water.  

Science.gov (United States)

Subcritical water hydrolysis was carried out to produce functional materials from squid muscle using a batch reactor. The reaction temperatures and pressures for hydrolysis of thermal dried squid muscle were maintained from 160 to 280 °C and 6 to 66 bar for 3 min. The ratio of material to water for hydrolysis was 1:25 (w/v) and it was stirred at 140 rpm. Hydrolysis yield was increased after increasing the temperature and pressure while the protein in hydrolyzate decreased with the rise of temperature. The reducing sugar yield was high at temperature 220 °C in subcritical water hydrolysis of squid muscle. Low molecular weight peptides were found in all hydrolyzates by SDS-PAGE. The highest yield of free and structural amino acid in hydrolyzate was 421.53?±?1.24 and 380.58?±?2.25 mg/100 g, respectively at 250 °C. All essential amino acids were identified in muscle hydrolyzates and it was high at 220 °C. Among the essential amino acids, leucine was the most abundant. Antioxidative properties were found in all hydrolyzates and it was high at 220 °C. More than 98?±?0.26 % ABTS antioxidant activity was retained in hydrolyzates after long time heat treatment. PMID:25694687

Asaduzzaman, A K M; Chun, Byung-Soo

2015-02-01

324

High energy-density water: density functional theory calculations of structure and electrical conductivity.  

Energy Technology Data Exchange (ETDEWEB)

Knowledge of the properties of water is essential for correctly describing the physics of shock waves in water as well as the behavior of giant planets. By using finite temperature density functional theory (DFT), we have investigated the structure and electronic conductivity of water across three phase transitions (molecular liquid/ ionic liquid/super-ionic/electronic liquid). There is a rapid transition to ionic conduction at 2000 K and 2 g/cm{sup 3} while electronic conduction dominates at temperatures above 6000 K. We predict that the fluid bordering the super-ionic phase is conducting above 4000 K and 100 GPa. Earlier work instead has the super-ionic phase bordering an insulating fluid, with a transition to metallic fluid not until 7000 K and 250 GPa. The tools and expertise developed during the project can be applied to other molecular systems, for example, methane, ammonia, and CH foam. We are now well positioned to treat also complex molecular systems in the HEDP regime of phase-space.

Desjarlais, Michael Paul; Mattsson, Thomas Kjell Rene

2006-03-01

325

Adsorption and dissociation of water on Zr(0001) with density-functional theory studies  

CERN Document Server

The adsorption and dissociation of isolated water molecule on Zr(0001) surface are theoretically investigated for the first time by using density-functional theory calculations. Two kinds of adsorption configurations with almost the same adsorption energy are identified as the locally stable states, i.e., the flat and upright configurations respectively. It is shown that the flat adsorption states on the top site are dominated by the 1$b_{1}$-$d$ band coupling, insensitive to the azimuthal orientation. The diffusion between adjacent top sites reveals that the water molecule is very mobile on the surface. For the upright configuration, we find that besides the contribution of the molecular orbitals 1$b_{1}$ and 3$a_{1}$, the surface$\\rightarrow$water charge transfer occurring across the Fermi level also plays an important role. The dissociation of H$_{2}$O is found to be very facile, especially for the upright configuration, in good accordance with the attainable experimental results. The present results affor...

Wang, Shuang-Xi; Zhang, Peng; Zhao, Jian; Li, Shu-Shen

2011-01-01

326

Function of tyrosine Z in water oxidation by photosystem II: electrostatical promotor instead of hydrogen abstractor.  

Science.gov (United States)

Photosynthetic water oxidation by photosystem II is mediated by a Mn4 cluster, a cofactor X still chemically ill-defined, and a tyrosine, YZ (D1-Tyr161). Before the final reaction with water proceeds to yield O2 (transition S4-->S0), two oxidizing equivalents are stored on Mn4 (S0-->S1-->S2), a third on X (S2-->S3), and a forth on YZ(S3-->S4). It has been proposed that YZ functions as a pure electron transmitter between Mn4X and P680, or, more recently, that it acts as an abstractor of hydrogen from bound water. We scrutinized the coupling of electron and proton transfer during the oxidation of YZ in PSII core particles with intact or impaired oxygen-evolving capacity. The rates of electron transfer to P680+, of electrochromism, and of pH transients were determined as a function of the pH, the temperature, and the H/D ratio. In oxygen-evolving material, we found only evidence for electrostatically induced proton release from peripheral amino acid residues but not from YZox itself. The positive charge stayed near YZox, and the rate of electron transfer was nearly independent of the pH. In core particles with an impaired Mn4 cluster, on the other hand, the rate of the electron transfer became strictly dependent on the protonation state of a single base (pK approximately 7). At pH S4 as a prerequisite for the formation of oxygen upon S4-->S0. PMID:9454606

Ahlbrink, R; Haumann, M; Cherepanov, D; Bögershausen, O; Mulkidjanian, A; Junge, W

1998-01-27

327

The thermodynamical response functions and the origin of the anomalous behavior of liquid water.  

Science.gov (United States)

The density maximum of water dominates the thermodynamics of the system under ambient conditions, is strongly P-dependent, and disappears at a crossover pressure P(cross) approximately 1.8 kbar. We study this variable across a wide area of the T-P phase diagram. We consider old and new data of both the isothermal compressibility K(T)(T, P), the pressure constant specific heat C(P)(T) and the coefficient of thermal expansion alpha(P) (T, P). We observe that K(T)(T) shows a minimum at T* approximately 315 +/- 5 K for all of the studied pressures, whereas, at the same temperature, C(P)(T) has the minimal variation as a function of P in the interval 1 bar-4 kbar. We find the behavior of alpha(P) also to be surprising: all the alpha(P)(T) curves measured at different P cross at T*. The experimental data show a "singular and universal expansivity point" at T* approximately 315 K and alpha(P)(T*) = 0.44 10(-3) K(-1). Unlike other water singularities, we find this temperature to be thermodynamically consistent in the relationship connecting the three response functions. By considering also the P-T behavior of the self-diffusion coefficient D(S) and of the NMR proton chemical shift delta we have the information that at T* the water local order points out, with decreasing T, the crossover from a normal fluid to the anomalous and complex liquid characterized by the many anomalies. PMID:24640487

Mallamace, Francesco; Corsaro, Carmelo; Mallamace, Domenico; Vasic, Cirino; Stanley, H Eugene

2013-01-01

328

A theoretical solution for the angular displacement of electrostatic one-degree-of-freedom torsional microactuators  

International Nuclear Information System (INIS)

A theoretical solution for the angular displacement of electrostatic one-degree-of-freedom (one-DOF) torsional microactuators has been obtained as a function of the applied voltage and geometry. A nonlinear moment balance equation, representing the behavior of the actuator, is theoretically solved for the angular displacement corresponding to the applied voltage. The pull-in voltage and angular displacement are also derived in closed forms to provide a guideline for the maximum voltage and angular displacement of the actuator. The theoretical angular displacement is validated by comparing with both static and dynamic responses obtained from Newton–Raphson method and Park method, respectively. The theoretical pull-in voltage is in good agreement with the numerical solution within an error of 0.32%, while the theoretical angular displacement follows the numerical solution within an error of 1.50%. As such, the angular displacement and the pull-in angular displacement and voltage that are expressed in closed forms can be used for the design and analysis of one-DOF torsional actuators that are widely employed for various MEMS

329

Effect of pressure on the anomalous response functions of a confined water monolayer at low temperature.  

Science.gov (United States)

We study a coarse-grained model for a water monolayer that cannot crystallize due to the presence of confining interfaces, such as protein powders or inorganic surfaces. Using both Monte Carlo simulations and mean field calculations, we calculate three response functions: the isobaric specific heat C(P), the isothermal compressibility K(T), and the isobaric thermal expansivity ?(P). At low temperature T, we find two distinct maxima in C(P), K(T), and ??(P)?, all converging toward a liquid-liquid critical point (LLCP) with increasing pressure P. We show that the maximum in C(P) at higher T is due to the fluctuations of hydrogen (H) bond formation and that the second maximum at lower T is due to the cooperativity among the H bonds. We discuss a similar effect in K(T) and ??(P)?. If this cooperativity were not taken into account, both the lower-T maximum and the LLCP would disappear. However, comparison with recent experiments on water hydrating protein powders provides evidence for the existence of the lower-T maximum, supporting the hypothesized LLCP at positive P and finite T. The model also predicts that when P moves closer to the critical P the C(P) maxima move closer in T until they merge at the LLCP. Considering that other scenarios for water are thermodynamically possible, we discuss how an experimental measurement of the changing separation in T between the two maxima of C(P) as P increases could determine the best scenario for describing water. PMID:23206014

Mazza, Marco G; Stokely, Kevin; Stanley, H Eugene; Franzese, Giancarlo

2012-11-28

330

Epitaxial growth by monolayer restricted galvanic displacement  

Directory of Open Access Journals (Sweden)

Full Text Available The development of a new method for epitaxial growth of metals in solution by galvanic displacement of layers pre-deposited by underpotential deposition (UPD was discussed and experimentally illustrated throughout the lecture. Cyclic voltammetry (CV and scanning tunneling microscopy (STM are employed to carry out and monitor a “quasi-perfect”, two-dimensional growth of Ag on Au(111, Cu on Ag(111, and Cu on Au(111 by repetitive galvanic displacement of underpotentially deposited monolayers. A comparative study emphasizes the displacement stoichiometry as an efficient tool for thickness control during the deposition process and as a key parameter that affects the deposit morphology. The excellent quality of layers deposited by monolayer-restricted galvanic displacement is manifested by a steady UPD voltammetry and ascertained by a flat and uniform surface morphology maintained during the entire growth process.

Vasili? Rastko

2012-01-01

331

Micrograting Displacement Sensor with Integrated Electrostatic Actuation  

Science.gov (United States)

A high-resolution micro-grating displacement sensor with diffraction-based and integrated electrostatic actuation is proposed and experimentally demonstrated. The Al reflecting membrane is fabricated at the bottom of a silicon moving part and the Au micro-gratings are patterned on a transparent substrate. This structure forms a phase sensitive diffraction grating, providing the displacement sensitivity of the micro-grating interferometer. It shows sensitivity adjustment and self-calibration capabilities with electrostatic actuation. Additional system components include a coherent light source, photodiodes, and required electronics. Experimental results show that the displacement sensor has a sensitivity of about 1.8 mV/nm and a resolution of less than 1 nm in the linear region. This displacement sensor is very promising in the fields requiring high sensitivity, broad dynamic range, and immunity to electromagnetic interference.

Yao, Bao-Yin; Feng, Li-Shuang; Wang, Xiao; Liu, Wei-Fang; Liu, Mei-Hua

2014-07-01

332

Cold water immersion enhances recovery of submaximal muscle function after resistance exercise.  

Science.gov (United States)

We investigated the effect of cold water immersion (CWI) on the recovery of muscle function and physiological responses after high-intensity resistance exercise. Using a randomized, cross-over design, 10 physically active men performed high-intensity resistance exercise followed by one of two recovery interventions: 1) 10 min of CWI at 10°C or 2) 10 min of active recovery (low-intensity cycling). After the recovery interventions, maximal muscle function was assessed after 2 and 4 h by measuring jump height and isometric squat strength. Submaximal muscle function was assessed after 6 h by measuring the average load lifted during 6 sets of 10 squats at 80% of 1 repetition maximum. Intramuscular temperature (1 cm) was also recorded, and venous blood samples were analyzed for markers of metabolism, vasoconstriction, and muscle damage. CWI did not enhance recovery of maximal muscle function. However, during the final three sets of the submaximal muscle function test, participants lifted a greater load (P effect size: 1.3, 38%) after CWI compared with active recovery. During CWI, muscle temperature decreased ?7°C below postexercise values and remained below preexercise values for another 35 min. Venous blood O2 saturation decreased below preexercise values for 1.5 h after CWI. Serum endothelin-1 concentration did not change after CWI, whereas it decreased after active recovery. Plasma myoglobin concentration was lower, whereas plasma IL-6 concentration was higher after CWI compared with active recovery. These results suggest that CWI after resistance exercise allows athletes to complete more work during subsequent training sessions, which could enhance long-term training adaptations. PMID:25121612

Roberts, Llion A; Nosaka, Kazunori; Coombes, Jeff S; Peake, Jonathan M

2014-10-15

333

The intergenerational effects of worker displacement  

OpenAIRE

This paper uses variation induced by firm closures to explore the intergenerational effects of worker displacement. Using a Canadian panel of administrative data that follows almost 60,000 father-child pairs from 1978 to 1999 and includes detailed information about the firms at which the father worked, we construct narrow treatment and control groups whose fathers had the same level of permanent income prior to 1982 when some of the fathers were displaced. We demonstrate that job loss leads t...

Page, Marianne; Stevens, Ann Huff; Oreopoulos, Philip

2005-01-01

334

Soil Structure Interaction in Displacement Based Design  

OpenAIRE

The research investigates how to deal with Soil-Structure Interaction (SSI) in the Direct Displacement Based Design (DDBD) procedure of precast concrete industrial and commercial buildings, whose structural layout is typically made by cantilever columns connected at the top by prestressed precast beams supporting prestressed precast concrete roof elements. In these particular structures, neglecting the SSI could lead to an underestimation of the seismic displacements and therefore to unexpect...

Belleri, Andrea; Riva, Paolo

2011-01-01

335

Explanation of Displacement Current in a Vacuum  

OpenAIRE

It is considered that the time derivative of the electric intensity in the Maxwell-Ampere law (displacement current) denotes that a change of electric field generates a magnetic field. This paper shows that there is no reason to think a change of electric field generates a magnetic field and the displacement current term has a different meaning. It is necessary to be aware of distant conductors and their magnetic fields.

Slechta, Petr

2006-01-01

336

48 CFR 952.226-74 - Displaced employee hiring preference.  

Science.gov (United States)

...2010-10-01 false Displaced employee hiring preference. 952.226-74 ...226-74 Displaced employee hiring preference. As prescribed in...following clause. Displaced Employee Hiring Preference (JUN 1997) (a)...

2010-10-01

337

40 CFR 86.419-2006 - Engine displacement, motorcycle classes.  

Science.gov (United States)

...classes. (a)(1) Engine displacement shall be calculated using...2) For rotary engines, displacement means the maximum volume...will be divided into classes based on engine displacement. (1) Class I—0 to...

2010-07-01

338

40 CFR 86.419-78 - Engine displacement, motorcycle classes.  

Science.gov (United States)

...classes. (a)(1) Engine displacement shall be calculated using...2) For rotary engines, displacement means the maximum volume...will be divided into classes based on engine displacement. (1) Class I—50...

2010-07-01

339

Organic functional group transformations in water at elevated temperature and pressure: Reversibility, reactivity, and mechanisms  

Science.gov (United States)

Many transformation reactions involving hydrocarbons occur in the presence of H2O in hydrothermal systems and deep sedimentary systems. We investigate these reactions using laboratory-based organic chemistry experiments at high temperature and pressure (300 °C and 100 MPa). Organic functional group transformation reactions using model organic compounds based on cyclohexane with one or two methyl groups provided regio- and stereochemical markers that yield information about reversibility and reaction mechanisms. We found rapidly reversible interconversion between alkanes, alkenes, dienes, alcohols, ketones, and enones. The alkane-to-ketone reactions were not only completely reversible, but also exhibited such extensive reversibility that any of the functional groups along the reaction path (alcohol, ketone, and even the diene) could be used as the reactant and form all the other groups as products. There was also a propensity for these ring-based structures to dehydrogenate; presumably from the alkene, through a diene, to an aromatic ring. The product suites provide strong evidence that water behaved as a reactant and the various functional groups showed differing degrees of reactivity. Mechanistically-revealing products indicated reaction mechanisms that involve carbon-centered cation intermediates. This work therefore demonstrates that a wide range of organic compound types can be generated by abiotic reactions at hydrothermal conditions.

Shipp, Jessie; Gould, Ian R.; Herckes, Pierre; Shock, Everett L.; Williams, Lynda B.; Hartnett, Hilairy E.

2013-03-01

340

Gastric emptying of water in children with severe functional fecal retention  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this study was to evaluate gastric emptying (GE in pediatric patients with functional constipation. GE delay has been reported in adults with functional constipation. Gastric emptying studies were performed in 22 children with chronic constipation, fecal retention and fecal incontinence, while presenting fecal retention and after resuming regular bowel movements. Patients (18 boys, median age: 10 years; range: 7.2 to 12.7 years were evaluated in a tertiary pediatric gastroenterology clinic. Gastric half-emptying time of water (reference range: 12 ± 3?min was measured using a radionuclide technique immediately after first patient evaluation, when they presented fecal impaction (GE1, and when they achieved regular bowel movements (GE2, 12 ± 5 weeks after GE1. At study admission, 21 patients had reported dyspeptic symptoms, which were completely relieved after resuming regular bowel movements. Medians (and interquartile ranges for GE1 and GE2 were not significantly different [27.0 (16 and 27.5 (21 min, respectively (P = 0.10]. Delayed GE seems to be a common feature among children with chronic constipation and fecal retention. Resuming satisfactory bowel function and improvement in dyspeptic symptoms did not result in normalization of GE data.

V.P.I. Fernandes

341

Gastric emptying of water in children with severe functional fecal retention  

Scientific Electronic Library Online (English)

Full Text Available The objective of this study was to evaluate gastric emptying (GE) in pediatric patients with functional constipation. GE delay has been reported in adults with functional constipation. Gastric emptying studies were performed in 22 children with chronic constipation, fecal retention an [...] d fecal incontinence, while presenting fecal retention and after resuming regular bowel movements. Patients (18 boys, median age: 10 years; range: 7.2 to 12.7 years) were evaluated in a tertiary pediatric gastroenterology clinic. Gastric half-emptying time of water (reference range: 12 ± 3?min) was measured using a radionuclide technique immediately after first patient evaluation, when they presented fecal impaction (GE1), and when they achieved regular bowel movements (GE2), 12 ± 5 weeks after GE1. At study admission, 21 patients had reported dyspeptic symptoms, which were completely relieved after resuming regular bowel movements. Medians (and interquartile ranges) for GE1 and GE2 were not significantly different [27.0 (16) and 27.5 (21) min, respectively (P = 0.10)]. Delayed GE seems to be a common feature among children with chronic constipation and fecal retention. Resuming satisfactory bowel function and improvement in dyspeptic symptoms did not result in normalization of GE data.

V.P.I., Fernandes; M.C.L., Lima; E.E., Camargo; E.F., Collares; J.M., Bustorff-Silva; E.A., Lomazi.

2013-03-15

342

In situ variations and relationships of water quality index with periphyton function and diversity metrics in Baiyangdian Lake of China.  

Science.gov (United States)

The variations and associations of abiotic and biotic variables in Baiyangdian Lake, China, were analyzed in situ. Abiotic variables included eleven water quality parameters, and were characterized by water quality index (WQI). Biotic variables included periphyton function and diversity metrics. WQI differed in different seasons at sampling sites and the highest value of WQI was observed in October 2009. Periphyton function metrics, expressed by extracellular enzyme activities of alkaline phosphatase, ?-glucosidase and leucine aminopeptidase, gross primary productivity and daily respiration rate, and diversity indices, in terms of Shannon diversity index and Berger-Parker abundance index, showed significantly temporal and spatial variations. Regression linear analysis illustrated a fairly good correlation of WQI with periphyton function and diversity indices, Shannon diversity index was the best correlated with WQI (r = 0.904, P water quality, and give us messages for monitoring water quality accurately. PMID:24557602

Yan, Jinxia; Liu, Jingling; Ma, Muyuan

2014-05-01

343

Analysis of displacement damage effects on MOS capacitors  

Energy Technology Data Exchange (ETDEWEB)

Displacement damage effect on MOS capacitors is analyzed in this work with the aid of TCAD simulations. A noticeable capacitance reduction in the accumulation mode is observed in the High Frequency C–V characteristic curve after a 24 GeV proton irradiation. This effect is clearly distinguishable from ionizing damage effects, otherwise negligible under the specific conditions of the experiment. The capacitance reduction is identified with the increase of the substrate resistivity, due to the modification of its effective doping concentration. Supported on a well-established traps model, the expected displacement damage defects are simulated as a function of the fluence, allowing the identification of donor trap levels as the responsible of the phenomenon for p-type substrate MOS capacitors.

Fernández-Martínez, P., E-mail: pablo.fernandez@imb-cnm.csic.es [Centro Nacional de Microelectrónica-Instituto de Microelectrónica de Barcelona, CNM-IMB (CSIC), Campus Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Palomo, F.R., E-mail: rogelio@gte.esi.us.es [Electronic Engineering Department, School of Engineering, Sevilla University, Avda. de los Descubrimientos s/n, 41092 Sevilla (Spain); Hidalgo, S.; Fleta, C.; Campabadal, F.; Flores, D. [Centro Nacional de Microelectrónica-Instituto de Microelectrónica de Barcelona, CNM-IMB (CSIC), Campus Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)

2013-12-01

344

Displacement estimates of pipe elbows prior to plastic collapse loads  

International Nuclear Information System (INIS)

The non-differentiability of the plastic dissipation calculated through the Von-Mises yield function leads to convergence difficulties when using mathematical programming to solve Koeiter's kinematical formulation of the classical limit analysis. This problem is avoided replacing the plastic dissipation by the strain energy of a fictitious viscoelastoplastic material with a nearly infinite Young modulus. Classical limit analysis can only give information about the limit load multiplier and the plastic collapse mechanism. Based on Zarka's method and using the finite element method and mathematical programming, it is possible to obtain not only the limit load but also an estimate of the elastoplastic displacements. This is very useful because construction codes usually impose limits on the electroplastic displacements. Some pipeline systems are examined using a 1-dimensional shell type finite element to illustrate the procedure. The results obtained are compared with simplified analytical solutions and with alternative numerical results using 2-dimensional shell elements and realistic materials. (orig.)

345

Plane Stratified Flow in a Room Ventilated by Displacement Ventilation  

DEFF Research Database (Denmark)

Nielsen, P. V. : Nickel, J. : Baron, D. J. G. Plane Stratified Flow in a Room Ventilated by Displacement Ventilation. Submitted for ROOMVENT 2004, Air Distribution in Rooms, 5 - 8 September 2004, Coimbra , Portugal ABSTRACT The air movement in the occupied zone of a room ventilated by displacement ventilation exists as a stratified flow along the floor. This flow can be radial or plane according to the number of wall-mounted diffusers and the room geometry. The paper addresses the situations where plane flow is obtained and a semi-analytical expression for the velocity level in the occupied zone is given. It is shown that the flow has a constant velocity level independent of the distance from the diffuser and that the thickness or length scale of the stratified flow has a tendency to be constant everywhere in the flow. The thickness and the velocity are functions of the Archimedes number

Nielsen, Peter Vilhelm; Nickel, J.

2004-01-01

346

Analysis of displacement damage effects on MOS capacitors  

International Nuclear Information System (INIS)

Displacement damage effect on MOS capacitors is analyzed in this work with the aid of TCAD simulations. A noticeable capacitance reduction in the accumulation mode is observed in the High Frequency C–V characteristic curve after a 24 GeV proton irradiation. This effect is clearly distinguishable from ionizing damage effects, otherwise negligible under the specific conditions of the experiment. The capacitance reduction is identified with the increase of the substrate resistivity, due to the modification of its effective doping concentration. Supported on a well-established traps model, the expected displacement damage defects are simulated as a function of the fluence, allowing the identification of donor trap levels as the responsible of the phenomenon for p-type substrate MOS capacitors

347

Predicting The Transition From Gravity-Dominated to Viscous-Dominated Displacements in Heterogeneous Porous Media  

Science.gov (United States)

One of the most important characteristics in miscible displacements of oil in porous medium when a less dense fluid displaces a more dense fluid is gravity. At low rates, gravity override will occur leading to early breakthrough of the injected fluid and poor oil recovery. However, at high rates, due to the unfavorable viscosity ratio, viscous fingering will dominate the displacement resulting in bypassing of oil. A systematic approach that combines high-resolution numerical simulations with laboratory imaging experiments were developed to investigate the transition between gravity-dominated to viscous-dominated miscible displacements as a function of the heterogeneity of the porous medium. Several heterogeneous porous media were used that cover a wide range of permeability variations. In each of these porous media, several unstable miscible displacements each with different levels of gravity segregation were performed. Results show that the degree and the structure of the heterogeneity of the porous medium have a significant effect on the type of displacements. For each porous medium, a critical value of gravity number appears to sort viscous- dominated to gravity-dominated displacements. This transition was determined as a function of the heterogeneity of the porous medium and compared very well with that observed experimentally.

Gharbi, R.; Qasem, F.

1998-11-01

348

Complications in Receiver Function Analysis on the Ocean Floor: Water and Sediment Reverberations  

Science.gov (United States)

Receiver function analysis of ocean bottom seismometer (OBS) data provides a unique opportunity for high resolution imaging of subsurface seismic discontinuities. However, because the OBS is located at the fluid solid boundary of the seafloor, reverberations from both the water column above and the oceanic crust below complicate the deconvolved signal. In addition, ultra slow sediment layers ( .5) converted phases from the crust-sediment boundary, reverberate in the sediment column. Using the 11 month OBS deployment of the Gravity Lineations Intraplate Melting Petrology and Seismologic Expedition (GLIMPSE) we observe both the water column reverberations on the pressure record of the instruments as well as the sediment layer reverberations on the radial component from teleseismic events. We use this data to parameterize both types of reverberations to enhance the interpretation of receiver functions. Synthetic seismograms indicate that the amplitudes of water reverberations dominate the pressure record with a more subtle effect on the vertical record. Using reflection coefficient and the two way travel times determined from the observed pressure records we deconvolved the reverberation signal from the pressure and vertical component of our data, reducing the amplitudes of the water column reverberations in both records for up to 25 s before the effects of focusing and defocusing of the reverberation signal by heterogeneities render the assumption of simple reflections on a flat plane invalid. Similar analysis of synthetic seismograms indicates that sediment reverberations dominate the high frequency spectra of the radial component. We determined the S-P amplitude and delay time for the P-S conversion from the crust-sediment boundary from a suite of events at different slownesses. As expected the delay times are constant and on the order of a few tenths of a second because of the near vertical incidence caused by the sudden drop in shear velocity, and the S-P amplitudes increase with increasing slowness. With these two parameters we are able to invert for sediment layer thickness and shear velocity, and perhaps more importantly provide a minimum station correction for S delay times for use in body wave tomography.

Harmon, N.; Forsyth, D. W.; Webb, S. C.

2005-12-01

349

Effect of water flow in gravel pack with regards to heavy oil production  

OpenAIRE

The objective of the thesis is to see how the effect of water is displacing the oil through gravel pack. Experimental solutions have been developed for displacement performance of two vertical displacements and one horizontal. The two vertical displacements were done to calculate the absolute permeability, relative permeabilities and saturations. Production performance and displacement efficiency was also determined to find out the recovery of the vertical displacement. The horizontal displac...

Ramstad, Barbro

2010-01-01

350

External fixation for displaced 2-part proximal humeral fractures.  

Science.gov (United States)

Studies have reported conflicting results regarding external fixation for displaced proximal humeral fractures. Compared with open reduction and internal fixation, external fixation for displaced proximal humeral fractures avoids dissection and soft tissue stripping and leads to higher union rates, a lower incidence of avascular necrosis, less scaring of the scapulohumeral interface, and faster rehabilitation. Some authors have reported good or excellent results and minimum complications compared with open reduction and internal fixation; however, others have reported that external fixation does not ensure acceptable reduction and fracture stability, especially in patients with osteoporosis.This article describes 18 patients with displaced 2-part fractures of the surgical neck of the humerus treated with closed reduction and external fixation using the Tension Guide Fixator (Gexfix SA, Carouge, Switzerland) external fixation system between 2010 and 2011. The patients included 14 women and 4 men with a mean age of 39 years. Mean follow-up was 18 months (range, 15-24 months). Fracture union; function using the Constant score, University of California Los Angeles score, Oxford score, and Quick Disabilities of the Arm, Shoulder and Hand shoulder score; and complications were evaluated. All patients experienced fracture union at a mean of 11 weeks (range, 9-13 weeks). The Tension Guide Fixator was removed without anesthesia at the outpatient clinic at a mean of 6 weeks (range, 4-8 weeks) with no loss of reduction or secondary displacement after removal. At 1-year follow-up, mean Constant and University of California Los Angeles scores were excellent, mean Oxford score showed satisfactory joint function, and mean Quick Disabilities of the Arm, Shoulder and Hand score showed minimal pain with no disability. PMID:23218629

Benetos, Ioannis S; Karampinas, Panayiotis K; Mavrogenis, Andreas F; Romoudis, Pavlos; Pneumaticos, Spiros G; Vlamis, John

2012-12-01

351

Thermal regulation of functional groups in running water ecosystems. Progress report, October 1, 1975--June 30, 1976  

Energy Technology Data Exchange (ETDEWEB)

Progress is reported on the following research projects: characterization of functional groups of running water organisms, particularly macroconsumers; studies on relationship of functional groups to qualitative and quantitative characteristics of organic inputs to stream ecosystems; studies on relationship of functional groups to thermal regimes; and dimensioning the control of feeding and growth by temperature and food quality and quantity and determining the extent of compensatory action of each. (HLW)

Cummins, K.W.; Klug, M.J.

1976-07-01

352

Surface-functionalized diatom microcapsules for drug delivery of water-insoluble drugs.  

Science.gov (United States)

Naturally available and biocompatible materials are potential substitutes for synthetic mesoporous materials as suitable drug carriers for the development of cost-effective drug delivery systems. This work investigates the application of a porous silica material derived from diatoms, also known as diatomaceous earth. The aim is to explore the surface functionalization of diatom microcapsules and their impact on the drug loading and release characteristics of water-insoluble drugs. Indomethacin was used as the model for poorly soluble drug. The surface modification on diatoms was performed with two organosilanes; 3-aminopropyltriethoxy silane and N-(3-(trimethoxysilyl) propyl) ethylene diamine and phosphonic acids (2-carboxyethyl-phosphonic acid and 16-phosphono-hexadecanoic acid) providing organic surface hydrophilic and hydrophobic properties. Extensive characterizations using scanning electron microscopy, X-ray photoelectron spectroscopy and differential scanning calorimetry was performed to confirm covalent grafting of monolayer aminosilane and phosphonic acid on the diatom surfaces. Differences in loading capacity of diatoms (15-24%) and release time (6-15 days) were observed which is due to the presence of different functional groups on the surface. It was found that 2-carboxyethyl-phosphonic acid, 3-aminopropyltriethoxy silane and N-(3-(trimethoxysilyl) propyl) ethylene diamine render diatom surfaces hydrophilic, due to polar carboxyl functional group (COOH) and active amine species (NH and NH2) that favor drug adsorption; better encapsulation efficiency and prolonged release of drugs, over the hydrophobic surface created by 16-phosphono-hexadecanoic acid. This work demonstrates diatom porous silica as a promising drug carrier, with possibility to further improve their performances by tailoring their surface functionalities to achieve the required drug loading and release characteristics for different therapeutic conditions. PMID:22457043

Aw, Moom Sinn; Bariana, Manpreet; Yu, Yang; Addai-Mensah, Jonas; Losic, Dusan

2013-08-01

353

Regional GHG emission transfer functions of peatlands: An analysis based on water levels from process-based hydrological modeling  

Science.gov (United States)

At the point scale, many studies on greenhouse gas (GHG) emissions from peatlands are focused on developing accurate transfer functions that relate the amount of GHG emissions to site characteristics, like water table depth, vegetation and physical and chemical soil properties. Given that for a specific peatland environment such a 'point-scale' transfer function is uniquely defined, it can be spatially applied when the necessary spatial information about the function parameters is available. Assuming the point-scale transfer function was developed on an annual time scale, the spatially-variable average site conditions of one year (e.g. annual mean water table depth) can be translated into a regional estimate of the total GHG budget. When the conditions of the system change, e.g. due to rewetting measures or different climatic conditions, changes of the regional GHG budget can be estimated by applying the point-scale transfer function to the new site conditions. Here, we discuss the behavior of the GHG budget variability against changes of the spatial water table depth distribution. The latter is obtained from spatially-distributed process-based hydrological modeling using the hydrological modeling framework SIMGRO (Alterra Wageningen). The interaction of groundwater, unsaturated zone and surface water fluxes was modeled for a peatland area of 200 ha (Großes Moor, Gifhorn, Germany) using spatial information on vegetation, peat layer thickness, hydraulic properties, surface water system, system boundary conditions and a laser-scan digital elevation model (DEM) as well as measured water level time series as calibration input. Based on the water level data from various hydrological scenarios, GHG budgets were estimated. Results demonstrate that the analysis of the GHG budgets as a function of different mean regional water table depths provides insights into the behavior of the regional GHG budget for the study area. The resulting curves can be called 'regional transfer functions'. In contrast to the point-scale transfer function, the regional transfer function is not unique and depends on the specific change of the hydrological status. For the study area discussed here, the regional transfer functions show that, at the regional scale, climate neutral conditions are difficult to achieve by rewetting measures. The regional transfer functions also indicate the hydrological condition that leads to the lowest total sum of GHG emissions, for which trade-off between methane and CO2 emissions is optimal at the regional scale.

Bechtold, Michel; Tegge, Arne; Leiber-Sauheitl, Katharina; Tiemeyer, Bärbel; Veldhuizen, Ab; Freibauer, Annette

2014-05-01

354

Effect of heavy water on structure-function relationship of lactate dehydrogenase from Lactobacillus casei  

International Nuclear Information System (INIS)

Structural and functional behaviour of lactate dehydrogenase purified from Lactobacillus casei was compared in H2O and heavy water (D2O). The enzyme showed reduced activity in D2O, being only 45% of that observed in H2O. The modulations of the enzyme caused by the substrate and fructose 1,6-diphosphate examined at varying pH and pD values indicated decreased cooperativity in D2O. The elution profiles of the enzyme on Sephadex G-200 in the presence of the substrate and fructose 1, 6-diphosphate at varying pD values showed a shift towards lower molecular weight species. At pD 5,4 fructose diphosphate did not cause any further shift in the elution pattern which was otherwise observed in H2O. (author)

355

Effects of heavy water on ultrastructural and functional status of Hep 2 and CHO cells lysosomes  

International Nuclear Information System (INIS)

The heavy water effects on the ultrastructure and function of Hep 2 and CHO lysosomal cell compartment were investigated using electron microscopy and enzymatic studies. The cell viability, measured by neutral red uptake assay and the total protein content determination, have shown a dose dependent decrease in cell growth for both studied cell types. The electron microscopy study has revealed a progressive increase in number and size of lysosomes and autophagosomes after 96 h exposure to different deuterium concentrations media in a dose dependent manner. The enzymatic determination in the lysosomal pellet revealed an increased acid phosphatase activity in both cell types (15% and 33% for Hep 2 and 24% and 52% for CHO, respectively) exposed to media with high (65%, 90%) D2O content. (authors)

356

Solubility products, thermodynamic functions and stability constants for the praseodymium and ytterbium fluoride - water systems  

International Nuclear Information System (INIS)

The solubility products and thermodynamic functions for the praseodymium and ytterbium fluoride-water systems were measured using different analytical techniques for comparison among the measured values and literature data. Although there is not much difference among the values obtained by potentiometric, conductometric and radiometric methods, the values for PrF3 disagree with at least two of the reported values. The standard enthalpy and free energy changes for the dissolution of both fluorides were found to be positive although the enthalpy for YbP3 is about twice as high as that for PrF3. The standard entropy change for PrF3 is negative, but that for YbF3 is positive. The overall stability constants for the mono- and difluoride complexes of both Pr and Yb were measured potentiometrically. (author) 23 refs.; 4 figs.; 7 tabs

357

Unique selectivity windows using selective displacers/eluents and mobile phase modifiers on hydroxyapatite.  

Science.gov (United States)

A detailed study was carried out to combine the unique selectivity of ceramic hydroxyapatite (CHA) with the separation power of selective displacement chromatography. A robotic liquid handling system was employed to carry out a parallel batch screen on a displacer library made up of analogous compounds. By incorporating positively charged, metal chelating and/or hydrogen bonding groups into the design of the displacer, specific interaction sites on CHA were targeted, thus augmenting the selectivity of the separation. The effect of different mobile phase modifiers, such as phosphate, sulfate, lactate and borate, were also investigated. Important functional group moieties and trends for the design of CHA displacers were established. Selective batch separations were achieved between multiple protein pairs which were unable to be resolved using linear gradient techniques, demonstrating the applicability of this technique to multiple protein systems. The specific interaction moieties used on the selective displacer were found to dictate which protein was selectively displaced in the separation, a degree of control not possible using a mono-interaction type resin in displacement chromatography. Mobile phase modifiers were also shown to play a crucial role, augmenting the selectivity of a displacer in a synergistic fashion. Column separations were carried out using selective displacers and mobile phase modifiers identified in the batch experiments, and baseline separation of the previously unresolved protein pairs was achieved. Further, the elution order in these systems was able to be reversed while still maintaining baseline separations. This work establishes a new class of separations which combine the selectivities of multi-modal resins, displacers/eluents, and mobile phase modifiers to create unique selectivity windows unattainable using traditional modes of operation. PMID:20832806

Morrison, Christopher J; Gagnon, Pete; Cramer, Steven M

2010-10-15

358

Comparison of Geophysical Model Functions for SAR Wind Speed Retrieval in Japanese Coastal Waters  

Directory of Open Access Journals (Sweden)

Full Text Available This work discusses the accuracies of geophysical model functions (GMFs for retrieval of sea surface wind speed from satellite-borne Synthetic Aperture Radar (SAR images in Japanese coastal waters characterized by short fetches and variable atmospheric stability conditions. In situ observations from two validation sites, Hiratsuka and Shirahama, are used for comparison of the retrieved sea surface wind speeds using CMOD (C-band model4, CMOD_IFR2, CMOD5 and CMOD5.N. Of all the geophysical model functions (GMFs, the latest C-band GMF, CMOD5.N, has the smallest bias and root mean square error at both sites. All of the GMFs exhibit a negative bias in the retrieved wind speed. In order to understand the reason for this bias, all SAR-retrieved wind speeds are separated into two categories: onshore wind (blowing from sea to land and offshore wind (blowing from land to sea. Only offshore winds were found to exhibit the large negative bias, and short fetches from the coastline may be a possible reason for this. Moreover, it is clarified that in both the unstable and stable conditions, CMOD5.N has atmospheric stability effectiveness, and can keep the same accuracy with CMOD5 in the neutral condition. In short, at the moment, CMOD5.N is thought to be the most promising GMF for the SAR wind speed retrieval with the atmospheric stability correction in Japanese coastal waters, although there is ample room for future improvement for the effect from short fetch.

Merete Badger

2013-04-01

359

Barrier function parameters in various keratinization disorders: transepidermal water loss and vascular response to hexyl nicotinate.  

Science.gov (United States)

In this study, we characterized the stratum corneum barrier function in 39 patients with various keratinization disorders (autosomal dominant ichthyosis vulgaris [ADI] [n = 7], X-linked recessive ichthyosis [XRI] [n = 6], autosomal recessive congenital ichthyosis [CI] [n = 10], dyskeratosis follicularis [Darier's disease; DD] [n = 8], erythrokeratoderma variabilis [EKV] [n = 8]), and 21 healthy volunteers, using two non-invasive methods: transepidermal water loss (TEWL) measuring outward transport of water through the skin by evaporimetry, and the vascular response to hexyl nicotinate (HN) penetration into the skin as determined by laser-Doppler flowmetry. Significantly increased TEWL values were found on the volar forearm in all three forms of ichthyosis, compared with the healthy control group, with the highest TEWL values in the CI group. The penetration of HN on the volar forearm was accelerated in patients with ADI, XRI and CI, as indicated by a shorter lag time (t0) between HN application and initial vascular response. However, differentiation between CI and the other ichthyoses was not possible by this method. When using both methods in DD and EKV, no differences compared with the healthy controls could be detected on the volar forearm, where the skin was principally unaffected; only the measurements from the affected skin on alternative sites demonstrated significantly increased TEWL values. In ADI and CI, however, normal-appearing skin also showed impaired values. We conclude that both TEWL and the vascular response to penetration of HN are suitable methods to monitor the skin barrier function in keratinization disorders, and are helpful in discriminating between these disorders. PMID:8251350

Lavrijsen, A P; Oestmann, E; Hermans, J; Boddé, H E; Vermeer, B J; Ponec, M

1993-11-01

360

Effect of combined function of temperature and water activity on the growth of Vibrio harveyi  

Scientific Electronic Library Online (English)

Full Text Available Vibrio harveyi is considered as a causative agent of the systemic disease, vibriosis, which occurs in many biological fields. The effects of temperatures (12.9-27.1 ºC) and water activity (NaCl% 0.6%-3.4%) on V. harveyi were investigated. The behavior and growth characteristics of V. harveyi was stu [...] died and modeled. Growth curves were fitted by using Gompertz and Baranyi models, and the Baranyi model showed a better fittness. Then, the maximum growth rates (µmax) and lag phase durations (LPD, ?) obtained from both Gompertz and Baranyi model were modeled as a combination function of temperature and water activity using the response surface and Arrhenius-Davey models for secondary model. The value of r², MSE, bias and accuracy factor suggest Baranyi model has better fitness than Gompertz model. Furthermore, validation of the developed models with independent data from ComBase also shown better interrelationship between observed and predicted growth parameter when using Baranyi model.

Kang, Zhou; Meng, Gui; Pinglan, Li; Shaohua, Xing; Tingting, Cui; Zhaohui, Peng.

1365-13-01

361

Defluoridation of water using chitosan assisted ethylenediamine functionalized synthetic polymeric blends.  

Science.gov (United States)

In this paper, a new kind of approach undertakes for the synthesis of novel chitosan (CS) blended with ethylenediamine (ED) functionalized synthetic polymers viz., acrylonitrile/divinylbenzene/vinylbenzyl chloride (CS@AN/DVB/VBC-ED) and styrene/divinylbenzene/vinylbenzyl chloride (CS@ST/DVB/VBC-ED) for defluoridation of water. Under batch mode, various influencing parameters like shaking time, pH, competitor ions and temperature were optimized. The fluoride removal was reasonably explained using Freundlich, Langmuir and D-R isotherms. The thermodynamic parameters viz., ?G°, ?H° and ?S° indicates the nature of the fluoride sorption with the sorbents. The FT-IR, XRD and SEM with EDAX analysis were used to study the fluoride adsorption of CS@AN/DVB/VBC-ED and CS@ST/DVB/VBC-ED blends. The thermal stability of both the sorbents was tested using TGA/DSC analysis. Studies were also conducted to test the potential application of the prepared polymeric blends for fluoride removal from field water collected from the nearby fluoride endemic area. PMID:25036602

Prabhu, Subbaiah Muthu; Viswanathan, Natrayasamy; Meenakshi, Sankaran

2014-09-01

362

Humic acids removal from water by aminopropyl functionalized rice husk ash.  

Science.gov (United States)

The use of rice husk ash (RHA) as an adsorbent for the adsorption of humic acids from water was studied. Optimum conditions for humic acids adsorption were found in batch method as follows, 60 min equilibrium time and initial in the range of pH 3-4. In addition, RHA was functionalized with 3-aminopropyltriethoxysilane. Again, the adsorption behavior of the modified rice husk ash (RHA-NH(2)) was studied. Optimum conditions for humic acids adsorption were found to be 30 min equilibrium time and initial pH in the range of 3-4. The adsorption capacity of RHA-NH(2) was higher than that of RHA. Experimental adsorption data fitted well with the Langmuir equation and the maximum adsorption capacity was 8.2mg/g. at pH 6. The column method was also performed. The comparative adsorption efficiencies of RHA-NH(2) and commercial activated carbons showed insignificant difference. The RHA-NH(2) adsorbent was applied for humic acids removal from surface water. PMID:20869173

Imyim, Apichat; Prapalimrungsi, Eakachai

2010-12-15

363

Surface Displacements Near The Itoiz Reservoir, Navarra, Spain  

Science.gov (United States)

The Itoiz reservoir, located in Navarra, northern Spain, is a newly constructed gravity dam that stores the water from the Irati and the Urrobi rivers. The dam has a total height of 121 m, a total length of 525 m and a maximum water storage volume of 410 hm3. The aim of this work is to study the surface displacement field during the impoundment of the Itoiz water reservoir. Satellite Radar Interferometry (InSAR) has been proven to be a useful and powerful tool in tectonic areas for surveying subtle surface deformations over several years related to geodynamic phenomena. A DInSAR observation technique, called the Coherent Pixel Technique, (CPT), is being applied to study the existence of deformation areas in order to obtain mean velocities and time series of deformation. In this study the stack used is composed by 22 ENVISAT ascending images concerning to the period 2003-2008, 15 ENVISAT descending images concerning the 2004-2007 period and 50 ERS ascendending images concerning the 1996-2008 period. We then compare the observation results with an analytical model. Surface water loads and the associated displacements are computed by means of the Boussinesq solution for a vertical point load on a homogeneous elastic half-space. The surface vertical forces can be expressed by means of F(x,y,t)=? gsh(x,y,t) where ? is the water density, g is the gravity aceleration, s is the area of the spatial sampling rate from a digital elevation model of Itoiz area and h(x,y,t) is the water column height that depends on the spatial location at surface (x,y) and the time t during the reservoir impoundment.

Arjona, A.; Santoyo, M. Á.; Seco, A.; Monells, D.; Fernández, J.; Luzón, F.; Mallorquí, J.

2009-05-01

364

Development of measurement of displacement of the top of sub-assembly using super sonic sensor  

International Nuclear Information System (INIS)

It has been studied for safety plant test to demonstrate inherent safety of FBR core in JOYO. As a part of this study investigation of feedback reactivity was studied. And analysis code which can estimate the reactivity of core-bowing has been prepared. In post irradiation examination, remain bowing displacement of sub-assembly can only be measured, so development of measuring system of displacement of sub-assembly under operation is expected to improve estimation of core-bowing reactivity. It is supposed that an on-line measurement system of displacement of the top of sub-assembly using super sonic sensor under operation is an effective means. In this report, development of measurement of displacement of the top of sub-assembly using super sonic sensor was settled as follows. Characteristic test of heat-resistant super sonic sensor, Design of adjustment device of super sonic sensor, Examination of in-water test for estimation of temperature fluctuation. (author)

365

Displacement of polymers. II. Experiment. Determination of segmental adsorption energy of poly(vinyl-pyrrolidone) on silica  

OpenAIRE

The displacement of poly(vinylpyrrolidone) (PVP) from silica in two different solvents (water and dioxane) by a number of low molecular weight organic displacers was studied. The experimental data compare favorably with a theory developed in a previous paper. Using this theory we determined the segmental adsorption energy for PVP to be 4 kT, both in dioxane.and in water. This result is in good agreement with inferences from calorimetric and spectroscopic-bound fraction studies.

Cohen Stuart, M. A.; Fleer, G. J.; Scheutjens, J. M. H. M.

1984-01-01

366

Response functions near the liquid-liquid critical point of ST2 water  

Science.gov (United States)

We simulate the ST2 water model for time periods up to 1000 ns, and for four different system sizes, N = 63, 73, 83, and 93. We locate the liquid-liquid phase transition line and its critical point in the supercooled region. Near the liquidliquid phase transition line, we observe that the system continuously flips between the low-density and high-density liquid phases. We analyze the transition line further by calculating two thermodynamic response functions, the isobaric specific heat capacity CP and the isothermal compressibility KT. We use two different methods: (i) from fluctuations and (ii) with the relevant thermodynamic derivative. We find that, within the accuracy of our simulations, the maxima of two different response functions occur at the same temperatures. The lines of CP and KT maxima below the critical pressure approximate the Widom line which is continuous with the line of first-order transitions in the two-phase region where we observe the phase flipping.

Lascaris, Erik; Kesselring, T. A.; Franzese, G.; Buldyrev, S. V.; Herrmann, H. J.; Stanley, H. E.

2013-02-01

367

Efficient solar water oxidation using photovoltaic devices functionalized with earth-abundant oxygen evolving catalysts.  

Science.gov (United States)

Indium tin oxide (ITO) surfaces of triple junction photovoltaic cells were functionalized with oxygen evolving catalysts (OECs) based on amorphous hydrous earth-abundant metal oxides (metal = Fe, Ni, Co), obtained by straightforward Successive Ionic Layer Adsorption and Reaction (SILAR) in an aqueous environment. Functionalization with Fe(iii) oxides gave the best results, leading to photoanodes capable of efficiently splitting water, with photocurrent densities up to 6 ± 1 mA cm(-2) at 0 V vs. the reversible hydrogen electrode (RHE) under AM 1.5 G simulated sunlight illumination. The resulting Solar To Hydrogen (STH) conversion efficiencies, measured in two electrodes configuration, were in the range 3.7-5%, depending on the counter electrode that was employed. Investigations on the stability showed that these photoanodes were able to sustain 120 minutes of continuous illumination with a loss at 0 V vs. RHE. Pristine photoanodic response of the cells could be fully restored by an additional SILAR cycle, evidencing that the observed loss is due to the detachment of the more weakly surface bound catalyst. PMID:23820552

Cristino, Vito; Berardi, Serena; Caramori, Stefano; Argazzi, Roberto; Carli, Stefano; Meda, Laura; Tacca, Alessandra; Bignozzi, Carlo Alberto

2013-08-21

368

THE DETERMINATION OF DISPLACEMENTS ON THE SURFACE OF THE HALF SPACE CAUSED BY AN INNER CRACK NUCLEATION  

Directory of Open Access Journals (Sweden)

Full Text Available The dynamic problem on determination of the wave field of displacements on the surface of the elastic halfspace caused by an inner crack nucleation is presented. The problem is solved using boundary integral equations. The relationships between the parameters of displacements of the body surface points and the functions of opening of the defect walls are derived and analyzed.

V. R. Skalskiy

2010-03-01

369

Immersion freezing of water and aqueous ammonium sulphate droplets initiated by Humic Like Substances as a function of water activity  

OpenAIRE

Immersion freezing of water and aqueous (NH4)2SO4 droplets containing Leonardite (LEO) and Pahokee peat (PP) serving as surrogates for Humic Like Substances (HULIS) has been investigated. Organic aerosol containing HULIS are ubiquitous in the atmosphere, however, their potential for ice cloud formation is uncertain. Immersion freezing has been studied for temperatures as low as 215 K and solution water activity,

Rigg, Y. J.; Alpert, P. A.; Knopf, D. A.

2013-01-01

370

Atomic displacement in solids: analysis of the primary event and the collision cascade. Part I: Neutron and positive ion irradiation  

International Nuclear Information System (INIS)

A modern, mathematical-physics introduction to the analytical problem of atomic displacement in solids which is both technically adequate and relevant to an introductory graduate students' curriculum in radiation damage theory is reported. The problematic of atomic displacement in solids is introduced didactically, deriving first the primary event (that is, the formation of the primary knock-on atom) and then building on that specific set of results in order to extend their basics to secondary, tertiary and higher-order progeny-the collision cascade-for both neutrons and positive ions, namely, their average damage functions, displacement cross-sections and energy spectra. A comparison of atomic displacement in solids under neutron and positive ion irradiation is discussed in terms of the physical concept of concentration of displaced atoms (or displacement dose)

371

Frequency and wave-vector dependent dielectric function of water: Collective modes and relaxation spectra  

Science.gov (United States)

The longitudinal frequency and wave-vector dependent complex dielectric response function ?(k,?)=1-1/?(k,?) is calculated in a broad range of k values by means of molecular dynamics computer simulation for a central force model of water. Its imaginary part, i.e., Im{?(k,?)}/|?(k,?)|2, shows two main contributions in the region of small k values: Debye-like orientational relaxation in the lower frequency part of the spectrum and a damped librational resonance at the high frequency wing. The Debye relaxation time does not follow a de Gennes-like pattern: ?(k) goes through a maximum at k?k*?1.7 Å-1, while the static polar structure factor S(k) peaks at k?3 Å-1. The resonance frequency ?(k) and the decay decrement ?(k) show a dispersion law, indicative of a decaying optical-like mode, the libron. With an approximate normal mode approach, we analyze the origin of this mode on a molecular level which shows that it is due to a damped propagation of molecular orientational vibrations through the network of hydrogen bonds. At high k the decay, due to dissipation of collective into single particle motions, dominates. The static dielectric function is calculated on the basis of the response function spectra via the Kramers-Kronig relation. In the small k region ?(k) decreases from the macroscopic value ??80 to a value ?15, i.e. it exhibits a Lorentzian-type behavior. This behavior is shown to be determined by higher order multipole correlation functions. In the intermediate and high k range, our results on ?(k) and ?(k) are in excellent agreement with data extracted from experimental partial pair correlation functions: ?(k) exhibits two divergence points on the k axis with a range of negative values in between where a maximum in ?(k) is found with ?max(k)?1, indicative of overscreening. Consequences of quantum corrections to ?(k) with respect to a purely classical calculation are discussed and consequences are shown for the interaction energy between hydrated ions.

Bopp, Philippe A.; Kornyshev, Alexei A.; Sutmann, Godehard

1998-08-01

372

The behaviour of 39 pesticides in surface waters as a function of scale  

Science.gov (United States)

A portion of applied pesticides runs off agricultural fields and is transported through surface waters. In this study, the behaviour of 39 pesticides is examined as a function of scale across 14 orders of magnitude from the field to the ocean. Data on pesticide loads in streams from two US Geological Survey programs were combined with literature data from field and watershed studies. The annual load as percent of use (LAPU) was quantified for each of the fields and watersheds and was used as the normalization factor across watersheds and compounds. The in-stream losses of each pesticide were estimated for a model stream with a 15 day travel time (similar in characteristics to the upper Mississippi River). These estimated in-stream losses agreed well with the observed changes in apparent LAPU values as a function of watershed area. In general, herbicides applied to the soil surface had the greatest LAPU values and minimal in-stream losses. Soil-incorporated herbicides had smaller LAPU values and substantial in-stream losses. Insecticides generally had LAPU values similar to the incorporated herbicides, but had more variation in their in-stream losses. On the basis of the LAPU values of the 39 pesticides as a function of watershed area, a generalized conceptual model of the movement of pesticides from the field to the ocean is suggested. The importance of considering both field runoff and in-stream losses is discussed in relation to interpreting monitoring data and making regulatory decisions. Published in 2001 by John Wiley & Sons, Ltd.

Capel, Paul D.; Larson, Steven J.; Winterstein, Thomas A.

2001-05-01

373

A mathematical model of the shore level displacement in Fennoscandia  

International Nuclear Information System (INIS)

The shore level displacement in Fennoscandia (Scandinavia and Finland) is mainly due to two cooperative vertical movements, the glacio-isostatic uplift and the eustatic sea level rise. The course of the glacio-isostatic uplift has recently been made discernible according to an investigation of the lake tilting phenomenon. This new information has made it possible to start an iteration process for detailed estimations of the uplift and the rise using empirical data of the shore level displacement. Arctan-functions have proved to be suitable tools for describing the glacio-isostatic uplift. The model indicates that there are two mechanisms involved in the glacio-isostatic uplift, one slow that can be linked to viscous flow, and one fast that might be explained by compression followed by decompression. The future development regarding the glacio-isostatic uplift, the eustasy and the shore level displacement is predicted in Fennoscandia using the results from the modeling. The predictions are based on the assumption that the crustal and eustatic developments will follow the trends that exist today. 124 refs, 98 figs

374

SIFT flow for large-displacement object tracking.  

Science.gov (United States)

Traditional tracking methods place an emphasis on how to cope with the variations in target appearance effectively. However, when the motion displacement of the target between image frames becomes larger, these methods may be unstable. This paper presents a novel (to our knowledge) visual object tracking method. In this method, we first introduce scale-invariant feature transform (SIFT) flow into the tracking problem and develop a real-time motion prediction method to capture large displacement between consecutive image frames. Then we use belief propagation (BP) to convert the problem of finding maximum a posteriori probability (MAP) to globally minimizing an energy function to get the best matching pairs of points for producing good candidate regions of the target. And last, the refined point trajectories are obtained according to the bidirectional flow field consistency estimation and covariance region descriptor matching, which can update model states efficiently so as to achieve enhanced robustness for visual tracking. Compared with the state-of-art tracking methods, the experimental results demonstrate that the proposed algorithm shows favorable performance when the object undergoes large motion displacement between image frames. PMID:25322097

Zhang, Huanlong; Hu, Shiqiang; Zhang, Xiaoyu

2014-09-20

375

Modelling of displacement washing of packed bed of fibers  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The mechanism of displacement washing of packed bed of porous, compressible and cylindrical particles, e.g., fibers, is presented with the help of an axial dispersion model involving Peclet number (Pe) and Biot number (Bi). Bulk fluid concentration, intra-pore solute concentration and concentration [...] of solute adsorbed on the fiber surface are taken to be the function of washing time and position in the bed. Concentration of solute adsorbed on the fiber surface and intra-pore solute concentration are related by a Langmuir adsorption isotherm. Experiments have been performed on pulp beds formed from unbeaten, unbleached kraft fibers. Displacement washing has been simulated using a laboratory washing cell. Model equations are solved by using orthogonal collocation on finite elements (OCFE). Model predicted values are compared with the experimental values and key industrial parameters such as displacement ratio and efficiency are expressed in terms of exit and average solute concentrations.

376

Relationships between leaf anatomy, morphology, and water use efficiency in Aloe vera (L) Burm f. as a function of water availability  

Scientific Electronic Library Online (English)

Full Text Available The effects of water availability were evaluated on the photosynthetic tissue anatomy in Aloe vera(L) Burm f. and its relationship with morphological, physiological parameters, and water use efficiency as a function of aerial biomass and gel production. Plants were subjected to four levels of water [...] availability equivalent to 20% (T1), 15% (T2), 10% (T3), and 5% (T4) of the atmospheric evaporative demand. The plants exhibited anatomical, morphological, and physiological responses to the different watering treatments. The extreme treatments produced negative responses due to excess water in T1 and water deficit in T4. Treatments T2 and T3 elicited positive responses in cell characteristics and productivity. Anatomical and structural characteristics were closely linked to physiology. Increased stomata number was negatively related to leaf length, width, and thickness (r = -0.85, -0.81, and -0.59, respectively) and to biomass production (r = -0.84), and positively related to the increase of cuticle thickness (r = 0.78). Treatment T2 showed the maximum efficiency of water use for biomass production (24.6 g L-1), which was closely related to cell size (r = 0.68) and number of stomata (r = -0.70).

Herman, Silva; Susana, Sagardia; Mauricio, Ortiz; Nicolás, Franck; Marcela, Opazo; Madeleine, Quiroz; Cecilia, Baginsky; Cristián, Tapia.

377

Incorporation of water into olivine during nebular condensation: Insights from density functional theory and thermodynamics, and implications for phyllosilicate formation and terrestrial water inventory  

Science.gov (United States)

Using density functional theory, we have examined the hydration mechanism of olivine with the objective of understanding the reaction pathways toward the formation of crystalline serpentine and brucite. It is found that further supply of water beyond saturation of the adsorption sites on olivine surfaces leads to the formation of amorphous brucite and serpentine molecules, with the latter forming in the subsurface domain. The calculated activation energy for this process is ~25 kJ mol-1, which permits formation of the amorphous materials well within the life span of the solar nebula. In addition, molecular dynamic simulations show that the adsorbed water in olivine is stable at least up to 900 K—a finding that is in accord with independent experimental studies. Thus, adsorption plus subsurface reaction of H2O in olivine could have taken place at temperatures considerably higher than the stability limit of hydrous minerals in the nebular condition. Using the DFT derived enthalpy of adsorption data, and reasonable approximation for the entropy of adsorption, we have calculated the fractional coverage of the reactive surface sites of olivine grains of spherical geometry by adsorbed water, and the corresponding ocean equivalent water (OEW) that could have been accreted into the Earth. These results suggest that adsorption and the associated subsurface hydroxylation of olivine grains might have been responsible for a significant fraction of the Earth's water budget. The adsorption of water into olivine crystals in the solar nebula might also have led to the delivery of water to other planetary bodies.

Asaduzzaman, Abu; Muralidharan, Krishna; Ganguly, Jibamitra

2015-03-01

378

Incorporation of water into olivine during nebular condensation: Insights from density functional theory and thermodynamics, and implications for phyllosilicate formation and terrestrial water inventory  

Science.gov (United States)

Using density functional theory, we have examined the hydration mechanism of olivine with the objective of understanding the reaction pathways toward the formation of crystalline serpentine and brucite. It is found that further supply of water beyond saturation of the adsorption sites on olivine surfaces leads to the formation of amorphous brucite and serpentine molecules, with the latter forming in the subsurface domain. The calculated activation energy for this process is ~25 kJ mol-1, which permits formation of the amorphous materials well within the life span of the solar nebula. In addition, molecular dynamic simulations show that the adsorbed water in olivine is stable at least up to 900 K—a finding that is in accord with independent experimental studies. Thus, adsorption plus subsurface reaction of H2O in olivine could have taken place at temperatures considerably higher than the stability limit of hydrous minerals in the nebular condition. Using the DFT derived enthalpy of adsorption data, and reasonable approximation for the entropy of adsorption, we have calculated the fractional coverage of the reactive surface sites of olivine grains of spherical geometry by adsorbed water, and the corresponding ocean equivalent water (OEW) that could have been accreted into the Earth. These results suggest that adsorption and the associated subsurface hydroxylation of olivine grains might have been responsible for a significant fraction of the Earth's water budget. The adsorption of water into olivine crystals in the solar nebula might also have led to the delivery of water to other planetary bodies.

Asaduzzaman, Abu; Muralidharan, Krishna; Ganguly, Jibamitra

2015-04-01

379

Experimental study of the formation of fractal structures during oil displacement  

Energy Technology Data Exchange (ETDEWEB)

A macroprocess to determine the direction and rate of the liquid-liquid interface within an oil-bearing reservoir has been considered. The process of oil displacement by water using the Hele-Shaw cell has been studied. It has been shown that an optimum filtration rate exists, which is determined by the equality of molecular surface and hydrodynamic forces. Use of water treated by surfactants and composite systems as displacement agents has shown that the Chuoke formula does not always provide reliable results. The possibility of evaluating the pumping rate during the process of downhole treatment has been shown.

Salavatov, T.S.; Suleimanov, B.A. [Academy of Science, Baku (Azerbaijan). Inst. of Mathematics and Mechanics

1995-07-01

380

Effect of coupling displacement on thermal current of Frenkel-Kontorova lattices  

Science.gov (United States)

Effect of coupling displacement on thermal current of Frenkel-Kontorova (FK) lattices in the underdamped case is investigated by means of numerical calculations. The results indicate that: (i) as the system has less atoms and is symmetric, the coupling displacement can boost up its thermal current, and absolute value of the thermal current as a function of the coupling displacement exhibits one or two peaks, determined by period of the FK lattices. (ii) As the system with less atoms is asymmetric, the coupling displacement affects its thermal current only in the case of either negative temperature difference or positive temperature difference, depending on asymmetry of the on-site potentials of the FK lattices. The coupling displacement cannot only enhance negative differential thermal resistance effect but also regulate thermal rectifier of the system as a thermal switch. (iii) Along with an increasing atomic number of the FK lattices, the effect of the coupling displacement on the system gradually disappears. Our results have the implication that the coupling displacement between nonlinear lattices plays a crucial role in the design of thermal devices.

Zhang, Jianqiang; Chen, Xiuhua; Chen, Ruyin; Nie, Linru; Zheng, Zhigang

2014-06-01

381

A relationship between the fractal dimension and scaling groups of unstable miscible displacements  

Science.gov (United States)

A detailed two-dimensional flow visualization study was performed to examine the dynamics of viscous fingering in miscible displacements. Detailed quantitative miscible displacement experiments using a microcomputer-based imaging workstation on a variety of oil recovery fluid systems were performed. The effect of two dimensionless scaling groups, namely gravity number and viscosity ratio, on the displacement behavior was investigated. Based on image analysis, the irregular fingering patterns of the flow visualization experiments were analyzed for fractal characteristics. Results indicate that the areal sweep efficiency of unstable miscible displacement follows a fractal scaling law with a fractal dimension and proportionality constant related to the gravity number and the viscosity ratio. The study shows that the fractal dimension decreases with decreasing gravity number and increasing viscosity ratio. This relationship was mapped by an artificial neural network model, which can be used to estimate the fractal dimension and the proportionality constant of miscible displacements as functions of the two scaling groups. These results have potential application in the mathematical modeling of unstable EOR displacements and in the scaling of laboratory displacements to field conditions.

Gharbi, R. B. C.; Qasem, F.; Peters, E. J.

382

PSF dedicated to estimation of displacement vectors for tissue elasticity imaging with ultrasound  

DEFF Research Database (Denmark)

This paper investigates a new approach devoted to displacement vector estimation in ultrasound imaging. The main idea is to adapt the image formation to a given displacement estimationmethod to increase the precision of the estimation. The displacement is identified as the zero crossing of the phase of the complex cross-correlation between signals extracted from the lateral direction of the ultrasound RF image. For precise displacement estimation, a linearity of the phase slope is needed as well as a high phase slope. Consequently, a particular point spread function (PSF) dedicated to this estimator is designed. This PSF, showing oscillations in the lateral direction, leads to synthesis of lateral RF signals. The estimation is included in a 2-D displacement vector estimation method. The improvement of this approach is evaluated quantitatively by simulation studies. A comparison with a speckle tracking technique is also presented. The lateral oscillations improve both the speckle tracking estimation and our 2-D estimation method. Using our dedicated images, the precision of the estimation is improved by reducing the standard deviation of the lateral displacement error by a factor of 2 for speckle tracking and more than 3 with our method compared to using conventional images. Our method performs 7 times better than speckle tracking. Experimentally, the improvement in the case of a pure lateral translation reaches a factor of 7. Finally, the experimental feasibility of the 2-D displacement vector estimation is demonstrated on data acquired from a Cryogel phantom.

Liebgott, Herve; Wilhjelm, Jens E.

2007-01-01

383

Cumulative soil water evaporation as a function of depth and time  

Science.gov (United States)

Soil water evaporation is an important component of the surface water balance and the surface energy balance. Accurate and dynamic measurements of soil water evaporation enhance the understanding of water and energy partitioning at the land-atmosphere interface. The objective of this study is to mea...

384

Performance of displacement ventilation in practice  

DEFF Research Database (Denmark)

This paper presents results of a field study in offices with displacement ventilation. It comprises detailed physical measurements of the thermal environment and collection of occupants´ response at 227 workplaces. The results, both physical measurements and human response, identified draught as the major local discomfort in the rooms with displacement ventilation. Twenty-three percent of the occupants were daily bothered by draught. In some buildings the maintenance personnel tried to improve occupants´ thermal comfort by raising the supply air temperature or office workers themselves blocked the diffusers by rearranging the furniture. Half of the surveyed occupants were not satisfied with the indoor air quality. The main conclusion is that displacement ventilation needs careful design and room furnishing in order to ensure a comfortable environment. Occupants must understand the underlying ventilation principle. This will ensure proper and efficient operation of the system and occupants´ satisfaction.

Naidenov, K.; Pitchurov, G.

2002-01-01

385

Efficiency Improvements to the Displacement Based Multilevel Structural Optimization Algorithm  

Science.gov (United States)

Multilevel Structural Optimization (MSO) continues to be an area of research interest in engineering optimization. In the present project, the weight optimization of beams and trusses using Displacement based Multilevel Structural Optimization (DMSO), a member of the MSO set of methodologies, is investigated. In the DMSO approach, the optimization task is subdivided into a single system and multiple subsystems level optimizations. The system level optimization minimizes the load unbalance resulting from the use of displacement functions to approximate the structural displacements. The function coefficients are then the design variables. Alternately, the system level optimization can be solved using the displacements themselves as design variables, as was shown in previous research. Both approaches ensure that the calculated loads match the applied loads. In the subsystems level, the weight of the structure is minimized using the element dimensions as design variables. The approach is expected to be very efficient for large structures, since parallel computing can be utilized in the different levels of the problem. In this paper, the method is applied to a one-dimensional beam and a large three-dimensional truss. The beam was tested to study possible simplifications to the system level optimization. In previous research, polynomials were used to approximate the global nodal displacements. The number of coefficients of the polynomials equally matched the number of degrees of freedom of the problem. Here it was desired to see if it is possible to only match a subset of the degrees of freedom in the system level. This would lead to a simplification of the system level, with a resulting increase in overall efficiency. However, the methods tested for this type of system level simplification did not yield positive results. The large truss was utilized to test further improvements in the efficiency of DMSO. In previous work, parallel processing was applied to the subsystems level, where the derivative verification feature of the optimizer NPSOL had been utilized in the optimizations. This resulted in large runtimes. In this paper, the optimizations were repeated without using the derivative verification, and the results are compared to those from the previous work. Also, the optimizations were run on both, a network of SUN workstations using the MPICH implementation of the Message Passing Interface (MPI) and on the faster Beowulf cluster at ICASE, NASA Langley Research Center, using the LAM implementation of UP]. The results on both systems were consistent and showed that it is not necessary to verify the derivatives and that this gives a large increase in efficiency of the DMSO algorithm.

Plunkett, C. L.; Striz, A. G.; Sobieszczanski-Sobieski, J.

2001-01-01

386

Novel Pd Catalysts with ?-Diketiminates for Homopolymerization of Functionalized Norbornene Derivatives in Water/Organic Mixed Solvents  

Energy Technology Data Exchange (ETDEWEB)

Polynorbornenes prepared by vinyl addition pathway are known to have some desirable characteristics for wider application but they have some critical drawbacks such as brittleness, poor solubility and adhesion. In order to improve these drawbacks, extensive research for the successful homo- and copolymerization of polar functionalized norbornene with olefin has been carried out. Even though considerable advance has been achieved in the polymerization of polar functionalized monomers, successful catalytic systems for the homopolymerization of polar functionalized norbornene are rare. In this study, a novel successful catalytic system for the polymerization of polar functionalized norborene is proposed. This system employs Pd ?-diketiminate/borate cocatalyst in water/organic mixed solvents and it is unique due to introduction of water as a component of solvents. Polymers obtained in this study show high Mw with narrow PDI. Effects of several reaction parameters to the polymer activity and properties are investigated and optimal catalytic system are proposed.

Lee, Eung Jun; Won, Wook Kyoung; Lee, Byoungkil; Kye, Youn Hee; Lee Ik Mo [Inha Univ., Incheon (Korea, Republic of)

2013-09-15

387

Impaired free water excretion in child C cirrhosis and ascites: relations to distal tubular function and the vasopressin system  

DEFF Research Database (Denmark)

Abstract Background: Water retention in advanced cirrhosis and ascites may involve disturbances in renal distal tubular function and in the vasopressin system. Methods: Twelve patients with Child B cirrhosis and ascites were compared with 11 patients with Child C cirrhosis and ascites. The subjects were studied during a 400 ml/h oral water load. Results: Child C patients had a lower baseline glomerular filtration rate (32 vs 63 ml/min, P<0.001) and a lower urinary flow rate (V(u)) (0.86 vs 1.95 ml/min, P<0.001) than the Child B patients. However, the free water clearance () did not differ (-0.60 vs -0.21 ml/min, P=0.20). After the water loading, plasma vasopressin (AVP) decreased significantly in both the groups (P<0.05). The Child B patients had increased V(u) (1.95-3.24 ml/min, P<0.001) and (-0.21-1.21 ml/min, P<0.01) and distal fractional water excretion (10.5 vs 0% in Child C, P=0.01) and aquaporin-2 (AQP2) (P<0.058) after water loading. In contrast, the Child C patients did not have increased V(u) and in response to the water and the decrease in AVP. Furthermore, the markers of distal tubular water regulation, AQP2 excretion and distal fractional water excretion, were unaltered. Conclusion: In Child C cirrhosis, ascites and mild hyponatraemia, there is an impaired ability to excrete solute-free water. The patients are characterised by a low glomerular filtration rate, a low distal tubular flow and an inability to increase free water clearance during water loading. This may be related to a vasopressin-independent production of AQP2.

Krag, Aleksander; MØller, SØren

2010-01-01

388

A single-mask thermal displacement sensor in MEMS  

Science.gov (United States)

This work presents a MEMS displacement sensor based on the conductive heat transfer of a resistively heated silicon structure towards an actuated stage parallel to the structure. This differential sensor can be easily incorporated into a silicon-on-insulator-based process, and fabricated within the same mask as electrostatic actuators and flexure-based stages. We discuss a lumped capacitance model to optimize the sensor sensitivity as a function of the doping concentration, the operating temperature, the heater length and width. We demonstrate various sensor designs. The typical sensor resolution is 2 nm within a bandwidth of 25 Hz at a full scale range of 110 µm.

Krijnen, B.; Hogervorst, R. P.; van Dijk, J. W.; Engelen, J. B. C.; Woldering, L. A.; Brouwer, D. M.; Abelmann, L.; Soemers, H. M. J. R.

2011-07-01

389

Effect of Body Mass Index on Intrafraction Prostate Displacement Monitored by Real-Time Electromagnetic Tracking  

Energy Technology Data Exchange (ETDEWEB)

Purpose: To evaluate, using real-time monitoring of implanted radiofrequency transponders, the intrafraction prostate displacement of patients as a function of body mass index (BMI). Methods and Materials: The motions of Beacon radiofrequency transponders (Calypso Medical Technologies, Seattle, WA) implanted in the prostate glands of 66 men were monitored throughout the course of intensity modulated radiation therapy. Data were acquired at 10 Hz from setup to the end of treatment, but only the 1.7 million data points with a 'beam on' tag were used in the analysis. There were 21 obese patients, with BMI {>=}30 and 45 nonobese patients in the study. Results: Mean displacements were least in the left-right lateral direction (0.56 {+-} 0.24 mm) and approximately twice that magnitude in the superior-inferior and anterior-posterior directions. The net vector displacement was larger still, 1.95 {+-} 0.47 mm. Stratified by BMI cohort, the mean displacements per patient in the 3 Cartesian axes as well as the net vector for patients with BMI {>=}30 were slightly less (<0.2 mm) but not significantly different than the corresponding values for patients with lower BMIs. As a surrogate for the magnitude of oscillatory noise, the standard deviation for displacements in all measured planes showed no significant differences in the prostate positional variability between the lower and higher BMI groups. Histograms of prostate displacements showed a lower frequency of large displacements in obese patients, and there were no significant differences in short-term and long-term velocity distributions. Conclusions: After patients were positioned accurately using implanted radiofrequency transponders, the intrafractional displacements in the lateral, superior-inferior, and anterior-posterior directions as well as the net vector displacements were smaller, but not significantly so, for obese men than for those with lower BMI.

Butler, Wayne M., E-mail: wbutler@wheelinghospital.org [Schiffler Cancer Center, Wheeling Hospital, Wheeling, West Virginia (United States); Wheeling Jesuit University, Wheeling, West Virginia (United States); Morris, Mallory N. [Schiffler Cancer Center, Wheeling Hospital, Wheeling, West Virginia (United States); Merrick, Gregory S. [Schiffler Cancer Center, Wheeling Hospital, Wheeling, West Virginia (United States); Wheeling Jesuit University, Wheeling, West Virginia (United States); Kurko, Brian S.; Murray, Brian C. [Schiffler Cancer Center, Wheeling Hospital, Wheeling, West Virginia (United States)

2012-10-01

390

One-pot synthesis of molecular bottle-brush functionalized single-walled carbon nanotubes with superior dispersibility in water.  

Science.gov (United States)

Molecular bottle-brush functionalized single-walled carbon nanotubes (SWCNTs) with superior dispersibility in water are prepared by a one-pot synthetic methodology. Elongating the main-chain and side-chain length of molecular bottle-brushes can further increase SWCNT dispersibility. They show significant enhancement of SWCNT dispersibility up to four times higher than those of linear molecular functionalized SWCNTs. PMID:24307218

Deng, Yong; Hu, Qin; Yuan, Qiulin; Wu, Yan; Ling, Ying; Tang, Haoyu

2014-01-01

391

Impact of variable [CO2] and temperature on water transport structure-function relationships in Eucalyptus.  

Science.gov (United States)

Nearly 30 years ago, Whitehead and Jarvis and Whitehead et al. postulated an elegant mechanistic explanation for the observed relationship between tree hydraulic structure and function, hypothesizing that structural adjustments promote physiological homeostasis. To date, this framework has been nearly completely overlooked with regard to varying atmospheric carbon dioxide ([CO(2)]). Here, we evaluated Whitehead's hypothesis of leaf water potential (?(l)) homeostasis in faster-growing (Eucalyptus saligna) and slower-growing (Eucalyptus sideroxylon) tree saplings grown under three [CO(2)] (pre-industrial, current and future) and two temperature (ambient and ambient + 4°C) treatments. We tested for relationships between physiological (stomatal conductance and ?(l)) and structural (leaf and sapwood areas (A(l), A(s)), height (h), xylem conductivity (k(s))) plant variables as a function of the [CO(2)] and temperature treatments to assess whether structural variables adjusted to maintain physiological homeostasis. Structural components (A(l), A(s), h) generally increased with [CO(2)] or temperature, while g(s) was negatively correlated with [CO(2)]. Contrary to Whitehead's hypothesis, ?(l) did not exhibit homeostasis in either species; elevated temperatures were associated with more negative ?(l) in faster-growing E. saligna, and less negative ?(l) in slower-growing E. sideroxylon. Moreover, individual structural variables were generally uncorrelated with ?(l). However, across both species, the integrated hydraulic property of leaf specific hydraulic conductance (K(l)) was positively correlated with an independent calculation of K(l) determined exclusively from leaf physiological variables. These results suggest that physiological homeostasis may not apply to saplings exposed to global change drivers including [CO(2)] and temperature. Nevertheless, Whitehead et al.'s formulation identified K(l) as a sensitive measure of plant structural-physiological co-variation across species. PMID:21712237

Phillips, Nathan G; Attard, Renee D; Ghannoum, Oula; Lewis, James D; Logan, Barry A; Tissue, David T

2011-09-01

392

Displacement and competitive sorption of organic pollutants on multiwalled carbon nanotubes.  

Science.gov (United States)

Displacement of lindane presorbed on the pristine and OH-functionalized multiwalled carbon nanotubes (MWCNTs) by phenanthrene, naphthalene, and atrazine, and competition of these compounds with lindane on the aforementioned sorbents were investigated. Displacement of lindane presorbed on MWCNTs by atrazine, naphthalene, and phenanthrene, and competitive sorption effect of these chemicals with lindane on MWCNTs followed the same order: atrazine > naphthalene > phenanthrene. The lowest competition and displacement of lindane by phenanthrene were mainly because of the strong interactions between these two chemicals, whereas interaction of lindane with atrazine and naphthalene was quite low. The more pronounced displacement of lindane by atrazine than naphthalene and higher competitive sorption of lindane with atrazine than with naphthalene can be ascribed to the larger molecular volume of atrazine; thus, the steric hindrance effect is higher relative to naphthalene. This study is valuable for evaluating influence of the coexisting organic compounds on sorption of primary solute towards MWCNTs in the environment. PMID:25028316

Shen, Xiaofang; Wang, Xilong; Tao, Shu; Xing, Baoshan

2014-10-01

393

Functional independence of monomeric CHIP28 water channels revealed by expression of wild-type mutant heterodimers.  

Science.gov (United States)

CHIP28 is a major water transporting protein in erythrocytes and kidney which forms tetramers in membranes (Verbavatz, J. M., Brown, D., Sabolic, I., Valenti, G., Ausiello, D. A., Van Hoek, A. N., Ma, T., and Verkman, A. S. (1993) J. Cell Biol. 123, 605-618). To determine whether CHIP28 monomers function independently, chimeric cDNA dimers were constructed which contained wild-type CHIP28 in series with either wild-type CHIP28, a non-water transporting CHIP28 mutant (C189W), or a functional but mercurial-insensitive CHIP28 mutant (C189S). Transcribed cRNAs were injected in Xenopus oocytes and plasma membrane expression was assayed by quantitative immunofluorescence. Water channel function was measured by osmotically induced swelling. CHIP28 homo- and heterodimers were targeted to the oocyte plasma membrane and functioned as water channels. Relative osmotic water permeability (Pf) values (normalized for plasma membrane expression of monomeric subunits) were: 1.0 (CHIP28 monomer), 0.0 (C189W), 1.07 (C189S), 1.10 (CHIP28-CHIP28 dimer) and 0.52 (CHIP28-C189W). The increase in oocyte Pf was linearly related to plasma membrane expression of wild-type CHIP28 and C189S subunits. HgCl2 (0.3 mM) inhibited chan