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1

Water displacement during sparging under perched water-table conditions  

International Nuclear Information System (INIS)

The feasibility of using sparging to purposefully displace perched water in silt loam soils was evaluated at a field site in northwestern Oklahoma. Soils and groundwater are contaminated with petroleum hydrocarbons, trichloroethene (TCE), and vinyl chloride. During sparging, a transient response in water level measurements was observed in observation wells which is attributed to water displacement. Evidence of water displacement was manifested by water-table collapse upon the cessation of sparging

2

WATER DISPLACEMENT DURING SPARGING UNDER PERCHED WATER-TABLE CONDITIONS  

Science.gov (United States)

The feasibility of using sparging to purposefully displace perched water in silt loam soils was evaluated at a field site in Northwestern Oklahoma. uring sparging, a transient response in water level measurements was observed in observation wells which is attributed to water disp...

3

Displacement of crude oil by water in continuously stratified systems  

Energy Technology Data Exchange (ETDEWEB)

A mathematical treatment of the following problem is presented: displacement of oil by water in a linear system with 50 layers of equal thickness; no residual water saturation; log normal permeabillity distribution; the layers having the same characteristics except for permeability; and Buckley-Leverett type displacement in every layer. The necessary formulas are given, and the results represented as curves of recovery vs. cumulative water injection. The results are also compared to those of a Dykstra-Parsons calculation. As expected, the recovery decreases as the nonuniformity of the system increases.

Codreanu, D.; Ioachimciuc, R.

1968-06-01

4

Functional outcome in conservatively treated non-displaced scaphoid fractures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Purpose: This study evaluated the functional outcome after conservative treatment of non-displaced scaphoid fractures using an international validated outcome scale (DASH). Methods and materials: Between 2005 and 2010, 60 patients with a non-displaced scaphoid fracture were included. When a patient visited the emergency department and was clinically suspected of a scaphoid fracture radiography was performed. If no fracture was diagnosed with this modality a CT or MRI-scan both in combination ...

Tessa Drijkoningen; Beeres, Frank J. P.; Leerdam, Roderick H.; Daan Ootes; Grootendorst, Diana C.; Marleen Otoide-Vree; Rhemrev, Steven J.

2012-01-01

5

Experimental Research on Profile Control for Oil Displacement by Functional Polymer in Low Permeability Fractured Reservoir  

Science.gov (United States)

Utilizing artificial fractured cores with low permeability, a physical simulation experiment on profile control for oil displacement was carried out. The result showed that 23.63% extra oil recovery was realized by functional polymer, and 29.05% extra oil recovery was realized by functional polymer with gas which is higher than water flooding alone. The experiment demonstrates that functional polymer is effective for enhance oil recovery for low permeability fractured reservoir significantly.

Li, Li; Xiuting, Han; Lin, Meng

6

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

7

Functional outcome in conservatively treated non-displaced scaphoid fractures  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: This study evaluated the functional outcome after conservative treatment of non-displaced scaphoid fractures using an international validated outcome scale (DASH. Methods and materials: Between 2005 and 2010, 60 patients with a non-displaced scaphoid fracture were included. When a patient visited the emergency department and was clinically suspected of a scaphoid fracture radiography was performed. If no fracture was diagnosed with this modality a CT or MRI-scan both in combination with bonescintigraphy was performed. Patients with scaphoid fractures diagnosed with CT/MRI and bonescintigraphy were treated with a six-week scaphoid forearm cast. Within 1 year after cast removal patients filled in the DASH questionnaire. Results: Sixty (80% patients returned the DASH questionnaire at 12 months after treatment. Thirty-eight (63.3% were male and the mean age was 35 (range 11 - 83. Forty-four (73.3% patients had a mid-waist fracture of the scaphoid, 13 (21.7% had a fracture of the distal pole and three (0.05% had a proximal fracture. Median DASH score at one year after the trauma was 6 (range 3 - 15 for patients with a distal pole fracture and 5 (range 0 - 21.5 for mid-waist fractures (p = 0.7, table 2. For the three patients with a proximal scaphoid fracture the DASH scores appeared higher and were 83, 82 and 30 respectively. Conclusion: Conservative treatment for six weeks with a below the elbow cast is sufficient for the majority of patients with an occult distal or mid-waist scaphoid fracture and results in a good functional outcome according to the DASH questionnaire.

Tessa Drijkoningen

2012-12-01

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

On the use of NURBS functions for displacement derivatives measurment by digital image correlation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, we propose to investigate the potential improvement of using Non-Uniform Rational B-Spline (NURBS) functions for displacement measurements by digital image correlation (DIC). The aim is at improving the performance of DIC to capture with low uncertainty and low noise levels not only the displacement field but also its derivatives. Indeed, when the displacement field is used to feed constitutive law identification procedures, displacement derivatives are required and thus may be...

Re?thore?, Julien; Elguedj, Thomas; Simon, Pierre; Coret, Michel

2010-01-01

10

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

11

Expansion of a function about a displaced centre  

International Nuclear Information System (INIS)

We review the progress recently made in obtaining closed form expressions for the expansion of general orbitals about a displaced centre and establish the equivalence between different expansions. We also examine how these expressions do have the desired limit as the displacement approaches zero. (author)

12

Comparison of positional surfactant isomers for displacement of rubisco protein from the air-water interface.  

Science.gov (United States)

Protein-surfactant interaction, which is a function of the protein and surfactant characteristics, is a common phenomenon in a wide range of industrial applications. In this work, we used rubisco, the most abundant protein in nature, as a model protein and sodium dodecylbenzenesulfonate (SDOBS), one of the most widely used commercial surfactants, with two positional isomers (SDOBS-2 and SDOBS-6), as a model surfactant. We first examined the surface tension and the mechanical properties of interfacial mixed rubisco-SDOBS films adsorbed at the air-water interface. The concentration of rubisco in solution was fixed at 0.1 mg mL(-1) while the SDOBS concentration varied from 0 to 150 ?M. Both the surface tension and the mechanical strength of the interfacial film decreased with increasing SDOBS concentration. Overall, the surface tension of a rubisco-SDOBS-6 mixture is lower than that of rubisco-SDOBS-2, while the mechanical strength of both systems is similar. Neutron reflection data suggest that rubisco protein is likely denatured at the interface. The populations of rubisco and SDOBS of the mixed systems at the interface were determined by combining non-deuterated and deuterated SDOBS to provide contrast variation. At a low surfactant concentration, SDOBS-6 has a stronger ability to displace rubisco from the air-water interface than SDOBS-2. However, when surfactant concentration reaches 50 ?M, SDOBS-2 has a higher population than SDOBS-6, with more rubisco displaced from the interface. The results presented in this work suggest that the extent of protein displacement from the air-water interface, and hence the nature of the protein-surfactant interactions at the interface, are strongly affected by the position of surfactant isomerisation, which might allow the design of formulations for efficient removal of protein stains. PMID:21571294

He, Lizhong; Onaizi, Sagheer A; Dimitrijev-Dwyer, Mirjana; Malcolm, Andrew S; Shen, Hsin-Hui; Dong, Chuchuan; Holt, Stephen A; Thomas, Robert K; Middelberg, Anton P J

2011-08-15

13

Micronized-coal-water slurry sprays from a diesel engine positive displacement fuel injection system  

Energy Technology Data Exchange (ETDEWEB)

Experiments have been conducted to characterize the sprays from a modified positive displacement fuel injection system for a diesel engine. Diesel fuel water and three concentrations of micronized-coal-water slurry were used in these experiments. The injection system includes an injection jerk pump driven by an electric motor, a specially designed diaphragm to separate the abrasive coal slurry fuel from the pump, and a single-hole fuel nozzle. The sprays were injected into a pressurized chamber equipped with windows. High speed movies and still photographs of the sprays were obtained. In addition, instaneous fuel line pressures and needle lifts were obtained. Data were acquired as a function of fluid, nozzle orifice diameter, rack setting and chamber conditions. The high speed movies were used to determine spray penetration and spray growth.

Caton, J.A.; Kihm, K.D.; Seshadri, A.K.; Zicterman, G. [Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering

1991-12-31

14

Comparison of total body water determinations in lactating women by anthropometry, water displacement, and deuterium isotope dilution  

International Nuclear Information System (INIS)

To expand the limited data on the total body water in lactating women, the authors have determined total body water contents, in eight subjects from anthropometric measurements, water displacement, and isotope dilution of deuterium oxide. On the day of the study, their skinfold thicknesses were measured over the biceps and triceps muscles and at the suprailiac and subscapular areas. Their body densities were measured by water displacement. Deuterium oxide was administered orally at 100 mg/kg of body weight. One predose milk sample was collected from each subject. The milk samples were defatted by centrifugation and the milk water was reduced to hydrogen gas for hydrogen isotope ratio measurements by gas-isotope-ratio mass spectrometry. The results indicated that total body water in lactating women estimated from anthropometric measurements was 49.7 +/- 3.3% of body weight, by water displacement was 54.9 +/- 7.2%, and by isotope dilution was 50.8 +/- 3.7%

15

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

16

Functional outcome following proximal humeral interlocking system plating for displaced proximal humeral fractures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aim: To assess the functional outcome following internal fixation with the PHILOS (proximal humeral interlocking system) for displaced proximal humeral fractures. Patients and Methods: We reviewed 30 consecutive patients treated surgically with the proximal humeral locking plate for a displaced proximal humeral fracture. Functional outcome was determined using the American Shoulder and Elbow Society (ASES) score and Constant Murley score. Results: Average age of the ...

Thyagarajan David; Haridas Samarth; Jones Denise; Dent Colin; Evans Richard; Williams Rhys

2009-01-01

17

Bayesian speckle tracking. Part I: an implementable perturbation to the likelihood function for ultrasound displacement estimation.  

Science.gov (United States)

Accurate and precise displacement estimation has been a hallmark of clinical ultrasound. Displacement estimation accuracy has largely been considered to be limited by the Cramer-Rao lower bound (CRLB). However, the CRLB only describes the minimum variance obtainable from unbiased estimators. Unbiased estimators are generally implemented using Bayes' theorem, which requires a likelihood function. The classic likelihood function for the displacement estimation problem is not discriminative and is difficult to implement for clinically relevant ultrasound with diffuse scattering. Because the classic likelihood function is not effective, a perturbation is proposed. The proposed likelihood function was evaluated and compared against the classic likelihood function by converting both to posterior probability density functions (PDFs) using a noninformative prior. Example results are reported for bulk motion simulations using a 6? tracking kernel and 30 dB SNR for 1000 data realizations. The canonical likelihood function assigned the true displacement a mean probability of only 0.070 ± 0.020, whereas the new likelihood function assigned the true displacement a much higher probability of 0.22 ± 0.16. The new likelihood function shows improvements at least for bulk motion, acoustic radiation force induced motion, and compressive motion, and at least for SNRs greater than 10 dB and kernel lengths between 1.5 and 12?. PMID:23287920

Byram, Brett; Trahey, Gregg E; Palmeri, Mark

2013-01-01

18

Improved Displacement Transfer Functions for Structure Deformed Shape Predictions Using Discretely Distributed Surface Strains  

Science.gov (United States)

In the formulations of earlier Displacement Transfer Functions for structure shape predictions, the surface strain distributions, along a strain-sensing line, were represented with piecewise linear functions. To improve the shape-prediction accuracies, Improved Displacement Transfer Functions were formulated using piecewise nonlinear strain representations. Through discretization of an embedded beam (depth-wise cross section of a structure along a strain-sensing line) into multiple small domains, piecewise nonlinear functions were used to describe the surface strain distributions along the discretized embedded beam. Such piecewise approach enabled the piecewise integrations of the embedded beam curvature equations to yield slope and deflection equations in recursive forms. The resulting Improved Displacement Transfer Functions, written in summation forms, were expressed in terms of beam geometrical parameters and surface strains along the strain-sensing line. By feeding the surface strains into the Improved Displacement Transfer Functions, structural deflections could be calculated at multiple points for mapping out the overall structural deformed shapes for visual display. The shape-prediction accuracies of the Improved Displacement Transfer Functions were then examined in view of finite-element-calculated deflections using different tapered cantilever tubular beams. It was found that by using the piecewise nonlinear strain representations, the shape-prediction accuracies could be greatly improved, especially for highly-tapered cantilever tubular beams.

Ko, William L.; Fleischer, Van Tran

2012-01-01

19

Position-momentum and number-phase Wigner functions and their respective displacement operators  

Science.gov (United States)

The Galilei invariance under displacements of position and momentum is a defining property of Wigner's quasi-probability function Wpm. The analogous defining property of the number-phase Wigner function WNP is invariance under discrete upward shifts in photon number and shifts in phase. We use these different invariance properties to highlight distinct differences and similarities between the two quasi-probability functions Wpm and WNP. In the process we introduce the number-shifted coherent states in analogy with the displaced number states and discuss their properties.

Vaccaro, J. A.; Joshi, Amitabh

1998-06-01

20

Fall with Linear Drag and Wien's Displacement Law: Approximate Solution and Lambert Function  

Science.gov (United States)

We present an approximate solution for the downward time of travel in the case of a mass falling with a linear drag force. We show how a quasi-analytical solution implying the Lambert function can be found. We also show that solving the previous problem is equivalent to the search for Wien's displacement law. These results can be of interest for…

Vial, Alexandre

2012-01-01

 
 
 
 
21

On the calculation of the treshold function of atom displacement in crystals  

International Nuclear Information System (INIS)

In the framework of the Vinetsky diffusion approach are fulfilled calculations of the threshold function of atom displacement in crystals. The Frenkel pair production cross sections are determined for Si and Ge in the case of electron irradiation in the energy interval 0.2-1 MeV

22

Experimental study of displacement of viscous oil in pipes by water  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

23

Fall with linear drag and Wien's displacement law: approximate solution and Lambert function  

International Nuclear Information System (INIS)

We present an approximate solution for the downward time of travel in the case of a mass falling with a linear drag force. We show how a quasi-analytical solution implying the Lambert function can be found. We also show that solving the previous problem is equivalent to the search for Wien's displacement law. These results can be of interest for undergraduate students, as they show that some transcendental equations found in physics may be solved without purely numerical methods. Moreover, as will be seen in the case of Wien's displacement law, solutions based on series expansion can be very accurate even with few terms. (paper)

24

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.

25

Functional outcome following proximal humeral interlocking system plating for displaced proximal humeral fractures  

Directory of Open Access Journals (Sweden)

Full Text Available Aim: To assess the functional outcome following internal fixation with the PHILOS (proximal humeral interlocking system for displaced proximal humeral fractures. Patients and Methods: We reviewed 30 consecutive patients treated surgically with the proximal humeral locking plate for a displaced proximal humeral fracture. Functional outcome was determined using the American Shoulder and Elbow Society (ASES score and Constant Murley score. Results: Average age of the patients was 58 years (range, 19-92 years. The average overall ASES score was 66.5. The average overall Constant score was 57.5. Conclusion: Our results show that good fracture stability was achieved, and the functional outcome was very good in younger patients and it declined with increasing age. Early mobilization of the shoulder can be achieved without compromising fracture union.

Thyagarajan David

2009-01-01

26

Displacement of oil by water in heterogeneous rocks and evaluation of hetreogeneity in reservoir engineering calculations  

Energy Technology Data Exchange (ETDEWEB)

The partial results are decribed of a research project being done in Romania on the possibilities of evaluating rock heterogeneity on a suitable scale for reservoir engineering calculations. The horizontal heterogeneity of rocks was studied from cores taken from horizontal bore holes in the Sarata-Monteoru mine. Findings showed that a marked heterogeneity existed which is measureable in centimeters. Tests of oil displacement by water on physical models revealed the existence of crossflow between layers. Calculations led to the conclusion that the variation of displacement processes in a heterogeneous system cannot be expressed by an average relative permeability curve combining the relative permeability curves of the uniform zones in a heterogeneous system. If the horizontal heterogeneity is quite pronounced, it appears that the detailed variation of the rock characteristics cannot be determined with precision. In reservoir engineering calculations, moreover, heterogeneity must be considered on a regional scale. (35 refs.)

Codreanu, D.; Vernescu, A.; Hauer, R.

1966-01-01

27

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

28

First-and Second-Order Displacement Transfer Functions for Structural Shape Calculations Using Analytically Predicted Surface Strains  

Science.gov (United States)

New first- and second-order displacement transfer functions have been developed for deformed shape calculations of nonuniform cross-sectional beam structures such as aircraft wings. The displacement transfer functions are expressed explicitly in terms of beam geometrical parameters and surface strains (uniaxial bending strains) obtained at equally spaced strain stations along the surface of the beam structure. By inputting the measured or analytically calculated surface strains into the displacement transfer functions, one could calculate local slopes, deflections, and cross-sectional twist angles of the nonuniform beam structure for mapping the overall structural deformed shapes for visual display. The accuracy of deformed shape calculations by the first- and second-order displacement transfer functions are determined by comparing these values to the analytically predicted values obtained from finite element analyses. This comparison shows that the new displacement transfer functions could quite accurately calculate the deformed shapes of tapered cantilever tubular beams with different tapered angles. The accuracy of the present displacement transfer functions also are compared to those of the previously developed displacement transfer functions.

Ko, William L.; Fleischer, Van Tran

2012-01-01

29

Large-Deformation Displacement Transfer Functions for Shape Predictions of Highly Flexible Slender Aerospace Structures  

Science.gov (United States)

Large deformation displacement transfer functions were formulated for deformed shape predictions of highly flexible slender structures like aircraft wings. In the formulation, the embedded beam (depth wise cross section of structure along the surface strain sensing line) was first evenly discretized into multiple small domains, with surface strain sensing stations located at the domain junctures. Thus, the surface strain (bending strains) variation within each domain could be expressed with linear of nonlinear function. Such piecewise approach enabled piecewise integrations of the embedded beam curvature equations [classical (Eulerian), physical (Lagrangian), and shifted curvature equations] to yield closed form slope and deflection equations in recursive forms.

Ko, William L.; Fleischer, Van Tran

2013-01-01

30

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

DEFF Research Database (Denmark)

The movement of connate water spiked with gamma emitting 22Na was studied during laboratory water flooding of oil saturated chalk from a North Sea oil reservoir. Using a one dimensional gamma monitoring technique is was observed that connate water is piled-up at the front of the injection water and forms a mixed water bank with almost 100% connate water in the front behind which a gradual transition to pure injection water occurs. This result underpins log interpretations from waterflooded chalk reservoirs. An ad hoc model was set up by use of the results, and the process was examined theoretically at a larger scale.

Korsbech, Uffe C C; Aage, Helle Karina

2006-01-01

31

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

32

Possibilities of crack mouth opening displacement (CMOD) measurement under boiling and pressurized water reactor conditions  

International Nuclear Information System (INIS)

Fracture mechanics investigations carried out so far in laboratory conditions cover only part of the material stresses, as effects which occur in nuclear powerstations, in particular, such as corrosion and radioactive radiation are largely left out of account. Therefore experiments including these effects were recently carried out in autoclaves, test rigs simulating reactors (HRD experimental plant) and in experimental reactors. An important parameter of experimental fracture mechanics is the measurement of crack opening displacement (COD). The crack opening is measured with socalled clip gauges (transmitters based on strain gauges, which convert mechanical deformation of springs into electrical signals) on standard samples in the laboratory. It was therefore sensible to use these high temperature strain gauges (HTD) for the development of a measuring system for travel for pressurized water and boiling water reactor conditions. (orig.)

33

Influence of reconstruction water-bearing levels on surface displacement of post-mining areas  

Science.gov (United States)

The phenomenon of secondary deformation characteristic of the post-mining areas is not sufficiently recognized. For ground surfaces phenomenon may be continuous or discontinuous. There is no sufficient information that describes behavior of the rock mass in the long term after end of exploitation. It is considered that this phenomenon is gradually disappears with end of exploitation. Reliable quantitative data comes only from the analysis of direct measurements in selected areas: geodetic and satellites measurements. Analyzing current situation of operating mines can be said that in the near years, more centers will limit the mining of coal mining. This will contribute to separation further of post-mining areas, in which will be required to maintaining a permanent monitoring and making predictions on the impact of ended exploitation of the rock mass surface. This will be particularly important for highly urbanized areas. This study used finite element method (FEM) to describe phenomenon of reconstruction water-bearing levels and its impact on displacement on the ground surface. It was assumed that significant factors that influence the occurrence and size of secondary deformations are: reconstruction of water-bearing levels in the prior drainer rock mass, size of past exploitation, spatial distribution of coal seams and geological and tectonic structure has been assumed. The transversally isotropic model of six elastic constants: E1 = E2, E3, ? = ?12, ?13, G12, G13 has been assumed to describe of rock mass in the numerical calculations. Geometrical models used in the numerical calculations have been developed using GIS tools. For the study two-dimensional and three-dimensional models characterized by different geological conditions and different configuration of mining data have been developed. The results obtained displacements of the ground surface for the period of mining activity has been verified with the results based on the Knothe theory. The results of analysis showed that during end of mining may claim to secondary deformations, significant in terms of surface displacement (subsidence or uplift of surface). It was also shown heterogeneous structure of the rock mass significantly affects the size and scope of surface displacement.

Milczarek, Wojciech; Blachowski, Jan; Grzempowski, Piotr

2014-05-01

34

Stresses and Displacements in Functionally Graded Materials of Semi-Infinite Extent Induced by Rectangular Loadings  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents the stress and displacement fields in a functionally graded material (FGM) caused by a load. The FGM is a graded material of Si3N4-based ceramics and is assumed to be of semi-infinite extent. The load is a distributed loading over a rectangular area that is parallel to the external surface of the FGM and either on its external surface or within its interior space. The point-load analytical solutions or so-called Yue’s solutions are used for the numerical integration over...

Zhong-Qi Yue; Hong-Tian Xiao

2012-01-01

35

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

36

Use of airborne and terrestrial lidar to detect ground displacement hazards to water systems  

Science.gov (United States)

We investigate the use of multiepoch airborne and terrestrial lidar to detect and measure ground displacements of sufficient magnitude to damage buried pipelines and other water system facilities that might result, for example, from earthquake or rainfall-induced landslides. Lidar scans are performed at three sites with coincident measurements by total station surveying. Relative horizontal accuracy is evaluated by measurements of lateral dimensions of well defined objects such as buildings and tanks; we find misfits ranging from approximately 5 to 12 cm, which is consistent with previous work. The bias and dispersion of lidar elevation measurements, relative to total station surveying, is assessed at two sites: (1) a power plant site (PP2) with vegetated steeply sloping terrain; and (2) a relatively flat and unvegetated site before and after trenching operations were performed. At PP2, airborne lidar showed minimal elevation bias and a standard deviation of approximately 70 cm, whereas terrestrial lidar did not produce useful results due to beam divergence issues and inadequate sampling of the study region. At the trench site, airborne lidar showed minimal elevation bias and reduced standard deviation relative to PP2 (6-20 cm), whereas terrestrial lidar was nearly unbiased with very low dispersion (4-6 cm). Pre- and posttrench bias-adjusted normalized residuals showed minimal to negligible correlation, but elevation change was affected by relative bias between epochs. The mean of elevation change bias essentially matches the difference in means of pre- and posttrench elevation bias, whereas elevation change standard deviation is sensitive to the dispersion of individual epoch elevations and their correlation coefficient. The observed lidar bias and standard deviations enable reliable detection of damaging ground displacements for some pipelines types (e.g., welded steel) but not all (e.g., concrete with unwelded, mortared joints). ?? ASCE 2009.

Stewart, J.P.; Hu, J.; Kayen, R.E.; Lembo, A.J., Jr.; Collins, B.D.; Davis, C.A.; O'Rourke, T. D.

2009-01-01

37

Stresses and Displacements in Functionally Graded Materials of Semi-Infinite Extent Induced by Rectangular Loadings  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the stress and displacement fields in a functionally graded material (FGM caused by a load. The FGM is a graded material of Si3N4-based ceramics and is assumed to be of semi-infinite extent. The load is a distributed loading over a rectangular area that is parallel to the external surface of the FGM and either on its external surface or within its interior space. The point-load analytical solutions or so-called Yue’s solutions are used for the numerical integration over the distributed loaded area. The loaded area is discretized into 200 small equal-sized rectangular elements. The numerical integration is carried out with the regular Gaussian quadrature. Weak and strong singular integrations encountered when the field points are located on the loaded plane, are resolved with the classical methods in boundary element analysis. The numerical integration results have high accuracy.

Zhong-Qi Yue

2012-01-01

38

Systematic treatment of displacements, strains and electric fields in density-functional perturbation theory  

CERN Document Server

The methods of density-functional perturbation theory may be used to calculate various physical response properties of insulating crystals including elastic, dielectric, Born charge, and piezoelectric tensors. These and other important tensors may be defined as second derivatives of the total energy with respect to atomic-displacement, electric-field, or strain perturbations, or as mixed derivatives with respect to two of these perturbations. The resulting tensor quantities tend to be coupled in complex ways in polar crystals, giving rise to a variety of variant definitions. For example, it is generally necessary to distinguish between elastic tensors defined under different electrostatic boundary conditions, and between dielectric tensors defined under different elastic boundary conditions. Here, we describe an approach for computing all of these various response tensors in a unified and systematic fashion. Applications are presented for two materials, wurtzite ZnO and rhombohedral BaTiO3, at zero temperatur...

Wu, X; Hamann, D R; Wu, Xifan; Vanderbilt, David

2005-01-01

39

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

40

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

 
 
 
 
41

Water displacement leg volumetry in clinical studies - A discussion of error sources  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Water displacement leg volumetry is a highly reproducible method, allowing the confirmation of efficacy of vasoactive substances. Nevertheless errors of its execution and the selection of unsuitable patients are likely to negatively affect the outcome of clinical studies in chronic venous insufficiency (CVI. Discussion Placebo controlled double-blind drug studies in CVI were searched (Cochrane Review 2005, MedLine Search until December 2007 and assessed with regard to efficacy (volume reduction of the leg, patient characteristics, and potential methodological error sources. Almost every second study reported only small drug effects (? 30 mL volume reduction. As the most relevant error source the conduct of volumetry was identified. Because the practical use of available equipment varies, volume differences of more than 300 mL - which is a multifold of a potential treatment effect - have been reported between consecutive measurements. Other potential error sources were insufficient patient guidance or difficulties with the transition from the Widmer CVI classification to the CEAP (Clinical Etiological Anatomical Pathophysiological grading. Summary Patients should be properly diagnosed with CVI and selected for stable oedema and further clinical symptoms relevant for the specific study. Centres require a thorough training on the use of the volumeter and on patient guidance. Volumetry should be performed under constant conditions. The reproducibility of short term repeat measurements has to be ensured.

Stücker Markus

2010-01-01

42

Carbon, land, and water footprint accounts for the European Union: consumption, production, and displacements through international trade.  

Science.gov (United States)

A nation's consumption of goods and services causes various environmental pressures all over the world due to international trade. We use a multiregional input-output model to assess three kinds of environmental footprints for the member states of the European Union. Footprints are indicators that take the consumer responsibility approach to account for the total direct and indirect effects of a product or consumption activity. We quantify the total environmental pressures (greenhouse gas emissions: carbon footprint; appropriation of biologically productive land and water area: land footprint; and freshwater consumption: water footprint) caused by consumption in the EU. We find that the consumption activities by an average EU citizen in 2004 led to 13.3 tCO(2)e of induced greenhouse gas emissions, appropriation of 2.53 gha (hectares of land with global-average biological productivity), and consumption of 179 m(3) of blue water (ground and surface water). By comparison, the global averages were 5.7 tCO(2)e, 1.23 gha, and 163 m(3) blue water, respectively. Overall, the EU displaced all three types of environmental pressures to the rest of the world, through imports of products with embodied pressures. Looking at intra-EU displacements only, the UK was the most important displacer overall, while the largest net exporters of embodied environmental pressures were Poland (greenhouse gases), France (land), and Spain (freshwater). PMID:23013466

Steen-Olsen, Kjartan; Weinzettel, Jan; Cranston, Gemma; Ercin, A Ertug; Hertwich, Edgar G

2012-10-16

43

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

44

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

45

Lagrangian analysis of MIV (Magnetic Impulse-Velocity) gauge experiments on PBX 9502 using the mass-displacement moment function  

Energy Technology Data Exchange (ETDEWEB)

Magnetic Impulse-Velocity (MIV) gauges were used to measure the impulse and particle-velocity fields at discrete Lagrangian positions in two samples of the TATB explosive PBX 9502. Each sample was shock driven by a 6.4 mm layer of reacting superfine TATB (/rho//sub 0/ = 1.80 g/cm/sup 3/), which was itself shocked by a gas driven projectile. The gauge histories of particle velocity and impulse, and the derived displacement history were simultaneously fit to the partial derivatives of the mass-displacement moment function employing a single set of parameters. (The function also gives volume, energy, pressure and their time derivatives.) With an assumed mixture equation of state, the reaction extent and reaction rate were calculated. The two experiments were compared and rate correlations were examined. 8 refs.

Forest, C.A.; Wackerle, J.; Dick, J.J.; Sheffield, S.A.; Pettit, D.R.

1989-01-01

46

Modelling the relationship between water level and vertical displacements on the Yamula Dam, Turkey  

Directory of Open Access Journals (Sweden)

Full Text Available Monitoring deformation pattern of dams is often one of the most effective ways to understand their safety status. The main objective of the study is to find the extent to which rising reservoir level affects the mechanism of deformation of The Yamula Dam under certain change in the reservoir level conditions during to the first filling period. Three different deformation analysis techniques, namely static, kinematic and dynamic, were used to analyze four geodetic monitoring records consisting of vertical displacements of nine object points established on the Dam and six reference points surrounding of it, to see whether the rising reservoir level have a role in the vertical deformations during the first filling period. The largest vertical displacements were in the middle of the dam. There is an apparent linear relationship between the dam subsidence and the reservoir level. A dynamic deformation model was developed to model this situation. The model infers a causative relationship between the reservoir level and the dam deformations. The analysis of the results determines the degree of the correlation between the change in the reservoir level and the observed structural deformation of the dam.

T. Bayrak

2007-01-01

47

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

48

Concept of a novel nano displacement magnetostrictive actuator with self-sensing function  

Science.gov (United States)

Giant magnetostrictive materials can be used in the micro driving or sensing system for that the shape of materials changes under the different external magnetic field, which is called one effect of magnetostriction. As for the common Terfenol-D bars, the magnetostriction is expressed by the length change in the direction of the magnetic field, and the value of length change is too small to be detected. This paper presents a design of nano scale driving and measuring system which utilizes the thick film resistor (TFR) strain gauge mounted on the surface of Terfenol-D bar to measure the strain change of giant magnetostrictive materials directly, the in-situ measuring method has better flexibility and sensibility than indirect measuring methods such as capacitor sensor or other displacement measuring devices. A DSP based weak signal processing system has been developed to excite the micro displacement sensing system and calculate the strain of Terfenol-D bars from the signal output from thick film strain gauge instantly. The design scheme improves the resolution and accuracy of deformation measurement of the Terfenol-D bar, which is fundamental to the control of system and fulfills the requirements of real-time precise driving or sensing.

Zhang, Guoqing; Pan, Zhongming

2011-12-01

49

Effect of a Selected Physical Exercise on the Development of Displacement Movement Skills in Highly Functional Autistic Children  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: The study is about to examine the effect of the selective physical exercises on the development of displacement skills in High Function Autistic (HFA) children. Materials and Methods: In this research, 10 children (7.9±1.4 years) among of 33 children with HFA in Sahr-e-Kord city (in Iran) based on their pre-test scores randomly were selected. The measuring tool was Test of Gross Motor Development-2000 (TGMD-2). Selected motor program (SPARK motor program) in this research incl...

Fatemeh Keyhani; Rasool Hemayat-Talab; Mahmoud Sheykh; Saeed Kosari

2014-01-01

50

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

51

Effect of a Selected Physical Exercise on the Development of Displacement Movement Skills in Highly Functional Autistic Children  

Directory of Open Access Journals (Sweden)

Full Text Available Background: The study is about to examine the effect of the selective physical exercises on the development of displacement skills in High Function Autistic (HFA children. Materials and Methods: In this research, 10 children (7.9±1.4 years among of 33 children with HFA in Sahr-e-Kord city (in Iran based on their pre-test scores randomly were selected. The measuring tool was Test of Gross Motor Development-2000 (TGMD-2. Selected motor program (SPARK motor program in this research includes motor strengthening activities, games and sports for children that were performed for 12 sessions by our subjects. Normal distribution of data checked by K-S test and appropriate statistical Levine's and ANOVA tests (dependent and independent types were used for compare mean values (?=0.05. Results: Twelfth sessions of selected physical exercises training in experiment group made significant differences in some research variables but it was not the case for the control group. There were significant differences in running (p=0.002, trotting (p=0.08, jumping (p=0.002 and gliding (p=0.004 and there were non-significant differences in hop (p=0.035 and leaping (p=0.02. Conclusion: According to the results of this research we suggest that the selected physical exercise programs that derived from SPARK motor program can improve displacement motor skills in children with HFA.

Fatemeh Keyhani

2014-09-01

52

Displacement of the crude oil by water in continously stratified systems. Pt. 1  

Energy Technology Data Exchange (ETDEWEB)

The known analytical solutions concerning the oil dislocation by water or in general the dislocation of 2 nonmiscible liquids can be divided into 2 categories: The first category consists of the solutions based on the presumption of the existence of a flooding front and the absence of an oil flow behind it, the saturation in oil being suddenly reduced at the value of the irreductible saturation. In some cases the viscosity of the fluids and the effective permeabilities are considered equal. For simple flow geometries, (unidimensional or radial) solutions were obtained in which the difference of viscosity between oil and water is taken into account and in other cases, the existence of 2 or 3 different mobility zones (the zone initially saturated with oil, the washed zone and eventually the zone initially saturated with water). The second category takes into consideration the existence of many zones. Solutions of different viscosities and mobilities were obtained also for nonuniform porous media on the vertical formed by layers of different permeabilities hydrodynamically separated. (41 refs.)

Codreanu, D.; Ionescu, P.

1968-04-01

53

Quantitative measures of damage to subchondral bone are associated with functional outcome following treatment of displaced acetabular fractures.  

Science.gov (United States)

Current analysis of displaced acetabular fractures is limited in its ability to predict functional outcome. This study aimed to (1) quantify initial acetabular damage following acetabular fracture through measurement of subchondral bone density and fracture lines, and (2) evaluate associations between acetabular damage and functional outcomes following fracture. Subchondral bone intensity maps were created for 24 patients with unilateral acetabular fractures. Measures of crack length and density differences between corresponding regions in the fractured acetabuli, normalized by the unfractured side, were generated from preoperative CT images. Damage measures were compared to quality of life survey data collected for each patient at least 2 years post-injury (Musculoskeletal Functional Assessment [MFA] and Short Form-36 [SF-36], with specific focus on parameters that best describe patients' physical health). CT image quantification of initial damage to acetabular subchondral bone was associated with functional outcome post-injury. In general, damage as quantified through differences in density in the superior dome region (zones 8 and 12) and the central anterior region of the acetabulum (zone 3) were found to be the strongest significant predictors of functional outcome (adjusted R(2) = 0.3-0.45, p fractures toward improving clinical prognoses. PMID:23940014

Lubovsky, Omri; Kreder, Michael; Wright, David A; Kiss, Alex; Gallant, Aimee; Kreder, Hans J; Whyne, Cari M

2013-12-01

54

Quantum displacements  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, first we explain what are the `quantum displacements'. We establish a group of bases, which contains the coupled bases coupling a ququart and a bipartite qubit systems. By these bases, we can realize the quantum displacements. We discuss some possible forms of them. At last, we point out that a so-call ''non-imprecisely-cloning theorem'' also holds.

Zhong, Zai-zhe

2004-01-01

55

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.

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

2014-03-01

56

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

57

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

Energy Technology Data Exchange (ETDEWEB)

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.

Guido, Ciro A., E-mail: ciro.guido@ecp.fr; Cortona, Pietro [Laboratoire Structures, Propriétés et Modélisation des Solides (SPMS), CNRS UMR 8580, École Centrale Paris, Grande Voie des Vignes, F-92295 Châtenay-Malabry (France); Adamo, Carlo [Laboratoire d’Électrochimie, Chimie des Interfaces et Modélisation pour l’Energie, CNRS UMR-7575, Chimie ParisTech, 11 rue P. et M. Curie, F-75231 Paris Cedex 05 (France); Institut Universitaire de France, 103 Bd Saint-Michel, F-75005 Paris (France)

2014-03-14

58

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

59

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

60

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

 
 
 
 
61

The role of pore geometry and connate water on miscible displacement of heavy oil with hydrocarbon solvents in strongly water-wet and oil-wet media using five-spot micromodels  

Energy Technology Data Exchange (ETDEWEB)

This paper reported on a study in which five-spot glass micromodels were used to investigate the hydrocarbon solvent flooding behaviour on heavy oil recovery in different wettability and pore geometries. This included the effects of wettability, connate water, different pore throat size ratio, throat-to-pore coordination number, and type of nonrandom heterogeneity of the porous media. The study demonstrated the successful use of micromodel experiments for studying enhanced oil recovery techniques in well defined five-spot models. It revealed that the displacement efficiency of the solvents depends on the surface wettability and is generally higher in strongly water-wet medium. A thin film of water coated the surface during hydrocarbon solvent injection in the water-wet condition in presence of connate water, thereby causing the oil to be displaced more easily. Also, some droplets in narrow throats caused the solvent to be more dispersed providing conditions for higher sweep efficiency. The study showed that there are more access routes connecting pores in pore systems with higher coordination numbers, which favors high displacement efficiency. Lowering the pore to throat ratio was shown to facilitate solvent propagation, causing higher recovery efficiency for miscible displacement. Heterogeneities provided higher residual oil saturation by making it easier for the solvent to bypass and causing the oil to be trapped. 11 refs., 2 tabs., 13 figs.

Dehghan, A.A. [Calgary Univ., AB (Canada); Tehran Petroleum Research Center, Tehran (Iran, Islamic Republic of); Petroleum Univ. of Technology Research Center, Tehran (Iran, Islamic Republic of); Farzaneh, S.A.; Kharrat, R.; Ghazanfari, M.H. [Tehran Petroleum Research Center, Tehran (Iran, Islamic Republic of); Petroleum Univ. of Technology Research Center, Tehran (Iran, Islamic Republic of)

2009-07-01

62

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

63

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

64

Fuel cycle and waste management. 4. Using the Water Displacer Rod Concept to Improve the Fuel Utilization of SMART  

International Nuclear Information System (INIS)

In this study, the water displacer rod (WDR) concept based on spectral shift technology was introduced to increase the fuel utilization of the System-integrated Modular Advanced Reactor (SMART) while minimizing the core design changes and the effects on the core safety. The WDR concept is a kind of mechanical spectral shift technology. SMART is a nuclear reactor of small capacity, 330 MW(thermal), and it has been developed by the Korea Atomic Energy Research Institute for the purpose of local heating and desalination of seawater. The refueling cycle and the fuel enrichment of SMART are 36 months and 4.95 wt%, respectively. The single-batch core is adapted for the convenience of maintenance activity. Especially, the core of SMART is a soluble boron free core. To predict the effect of WDR on the fuel utilization of SMART, a sensitivity analysis of the point of time and the numbers of WDR insertion/withdrawal was performed. The change of k? and the mass fraction of the residual fissile material were evaluated in the case of WDR application. To maximize the effect of WDR, the core was rearranged according to the sensitivity analysis. Figures 1a and 1b show the change of k? and the mass fraction of the fissile material for burnup increment. Burnup calculations were performed for the SMART cores with and without WDR. To evaluate the effect of WDR, the critical control rod positions for the burnup increment were compared for the two cases. Figure 2a compared for the two cases. Figure 2a shows the results of the comparison. WDR insertion is performed at 0 and 200 effective full-power days (EFPDs). WDR withdrawal is performed at 50 and 900 EFPDs. To evaluate the effect of WDR on the core safety, the three-dimensional local power peaking factor (Fq) and cold shutdown reactivity were analyzed. The maximum Fq of the core with WDR was 2.7154, and the cold shutdown reactivity was 0.98614. For each burnup step, the axial offsets of each case were analyzed, and Fig. 2b shows the result. According to the results of the burnup analysis, the cycle length increment is ?5 EFPDs. The cycle length did not increase as expected because of two following reasons. First, because of the high residual fuel enrichment, the effect of fissile plutonium was not remarkable. Second, the neutron absorption by burnable poison overwhelms that by fertile uranium. Therefore, conversion of fertile material to fissile material did not occur as much as expected. According to the results of the safety analysis, WDR application did not harm the reactor safety. In terms of the fine reactivity control capability of the WDR concept, it is worthy of application to the field of fuel management through the further studies on the optimization for the enrichment of the fuel and burnable poison. (authors)

65

Density-driven displacement of pore water as possible factor affecting the vertical distribution of Chernobyl-derived radionuclides in a Baltic Sea sediment  

International Nuclear Information System (INIS)

The vertical distribution of radionuclides in the bottom sediment of Gaevle Bay, southern Bothnian Sea, was investigated after the Chernobyl fallout. Sediment cores collected two years after the initial fallout revealed the highest radionuclide concentrations found in the Baltic Sea, reflecting the heavy fallout over this region. Concentrations of nuclides were almost constant down to about 8 cm sediment depth. Results from calculations by solving the one-dimensional diffusion equation were compared with the measured concentrations of radionuclide. The computed values were much lower than the observed ones, and diffusion alone could not account for the distribution pattern in the sediment. The macrobenthic community was scarce and vertical mixing of pore water could not be explained by bioturbation either. Vertical displacement of the pore water, caused by changes in density of the overlying water column, is a possible mechanism which could explain the rapid penetration of fallout nuclides in the soft bottom sediment. 8 refs, 16 figs, 3 tabs

66

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

67

Reduction of left ventricular longitudinal global and segmental systolic functions in patients with hypertrophic cardiomyopathy: Study of two-dimensional tissue motion annular displacement  

Science.gov (United States)

The early detection of abnormal left ventricular systolic functions in patients with hypertrophic cardiomyopathy (HCM) remains a challenge. The aim of this study was to identify a novel method for the assessment of left ventricular systolic function in patients with HCM. A total of 65 patients with HCM were included in this study. The patients were divided into obstructive HCM (HOCM; 16 cases) and non-obstructive HCM (NOHCM; 49 cases) groups. The healthy control group comprised 48 participants. Two-dimensional (2D) speckle-tracking technology was used to measure the left ventricular global and segmental longitudinal strains and mitral annular displacement (MADs). Compared with healthy control group, the six segmental strains and the global strain of the left ventricle (LSglobal) increased while six segmental MADs and MADglobal of the mitral annulus decreased in the HOCM and NOHCM groups (P<0.05). In addition, the six segmental MADs of the mitral annulus were significantly negatively correlated with the six segmental strains of the left ventricle (r=?0.744 to ?0.647, P<0.001). MADglobal was significantly negatively correlated with LSglobal (r=?0.857, P<0.001). The tissue motion annular displacement (TMAD) at the midpoint was significantly negatively correlated with LSglobal (r=?0.871, P<0.001). The 2D TMAD technique of measuring MAD was feasible and practically approachable for rapidly evaluating the left ventricular longitudinal global and segmental systolic functions of patients with HCM. PMID:24926326

LIU, LIWEN; TUO, SHENGJUN; ZHANG, JIANLEI; ZUO, LEI; LIU, FANG; HAO, LILI; SUN, YANDAN; YANG, LIPING; SHAO, HONG; QI, WEI; ZHOU, XIAODONG; GE, SHUPING

2014-01-01

68

Lateral displacement and rotational displacement sensor  

Energy Technology Data Exchange (ETDEWEB)

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

69

Combined effects of Mass and Velocity on forward displacement and phenomenological ratings: a functional measurement approach to the Momentum metaphor  

Directory of Open Access Journals (Sweden)

Full Text Available Representational Momentum (RepMo refers to the phenomenon that the vanishing position of a moving target is perceived as displaced ahead in the direction of movement. Originally taken to reflect a strict internalization of physical momentum, the finding that the target implied mass did not have an effect led to its subsequent reinterpretation as a second-order isomorphism between mental representations and principles of the physical world. However, very few studies have addressed the effects of mass on RepMo, and consistent replications of the null effect are lacking. The extent of motor engagement of the observers in RepMo tasks has, on the other hand, been suggested to determine the occurrence of the phenomenon; however, no systematic investigations were made of the degree to which it might modulate the effect of target mass. In the present work, we use Information Integration Theory to study the joint effects of different motor responses, target velocity and target mass on RepMo, and also of velocity and target mass on rating responses. Outcomes point not only to an effect of mass on RepMo, as to a differential effect of response modality on kinematic (e.g., velocity and dynamic (e.g., mass variables. Comparisons of patterns of mislocalisation with phenomenological ratings suggest that simplification of physical principles, rather than strict internalization or isomorphism per se, might underlie RepMo.

Michel-Ange Amorim

2010-01-01

70

Dynamical heterogeneity and the freezing transition in hard-sphere suspensions: further analysis of the mean square displacement and the velocity autocorrelation function.  

Science.gov (United States)

The velocity autocorrelation function is derived from the mean-squared displacement measured on a colloidal suspension of particles with hard-sphere-like interactions. It decays to zero from below and follows a stretched exponential function of delay time for the thermodynamically stable suspension. For the metastable suspension a power-law decay emerges. The results are discussed in terms of the classical Lorentz gas and the model that describes diffusion confined to one dimension. With the aid of these models, the experimental results provide a characterization of the dynamical heterogeneities which are observed microscopically, and an explanation for the enhanced resistance to flow and diffusion usually found in undercooled fluids upon approaching the glass transition. PMID:17930034

van Megen, W; Bryant, G

2007-08-01

71

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)

72

Structure–function analysis of the RNA polymerase cleft loops elucidates initial transcription, DNA unwinding and RNA displacement  

Science.gov (United States)

The active center clefts of RNA polymerase (RNAP) from the archaeon Pyrococcus furiosus (Pfu) and of yeast RNAP II are nearly identical, including four protruding loops, the lid, rudder, fork 1 and fork 2. Here we present a structure–function analysis of recombinant Pfu RNAP variants lacking these cleft loops, and analyze the function of each loop at different stages of the transcription cycle. All cleft loops except fork 1 were required for promoter-directed transcription and efficient elongation. Unprimed de novo transcription required fork 2, the lid was necessary for primed initial transcription. Analysis of templates containing a pre-melted bubble showed that rewinding of upstream DNA drives RNA separation from the template. During elongation, downstream DNA strand separation required template strand binding to an invariant arginine in switch 2, and apparently interaction of an invariant arginine in fork 2 with the non-template strand. PMID:18073196

Naji, Souad; Bertero, Michela G.; Spitalny, Patrizia; Cramer, Patrick; Thomm, Michael

2008-01-01

73

Clavicle hook plate fixation for displaced lateral-third clavicle fractures (Neer type II): a functional outcome study.  

LENUS (Irish Health Repository)

Controversy exists with the use of the acromioclavicular hook plate for the treatment of lateral-third clavicle fractures (Neer type II). This is thought to stem from problems associated with the hook plate causing impingement symptoms, which can cause long-term limitation of movement and pain. Our aim was to evaluate the functional outcomes of patients with lateral-third clavicle fractures treated with the hook plate.

Good, Daniel W

2012-08-01

74

Influence of water on the work function of certain metals  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Experiments were carried out to explore the effect of light on Au, Pt and Cu surfaces immersed in water, in order to study the changes of work function arising from the interaction between the metallic surfaces and water. The results show an action of liquid water about three times larger than that of low-temperature ice. Theoretical calculations, present in literature, have predicted values much lower than those we measured. The substantial changes in work function measured here appear to ar...

Musumeci, Francesco; Pollack, Gerald H.

2012-01-01

75

Probing the role of water in protein conformation and function.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Life began in a bath of water and has never escaped it. Cellular function has forced the evolution of many mechanisms ensuring that cellular water concentration has never changed significantly. To free oneself of any conceptual distinction among all small molecules, solutes and solvents, means that experiments to probe water's specific role in molecular function can be designed like any classical chemical reaction. Such an 'osmotic stress' strategy will be described in general and for an enzy...

Rand, R. P.

2004-01-01

76

Local and average crystal structure and displacements of La{sup 11}B{sub 6} and EuB{sub 6} as a function of temperature  

Energy Technology Data Exchange (ETDEWEB)

Measurements of both the average crystal structure from Rietveld refinement of neutron powder diffraction (NPD) data and the local structure from La L{sub III}-edge x-ray-absorption fine-structure (XAFS) are presented for a La{sup 11}B{sub 6} sample as a function of temperature ({approx}10-320 K). These data are compared to XAFS results on a EuB{sub 6} sample. The single-site La and B positional distribution widths and the La-B and La-La bond length distribution widths and their temperature dependence are compared. This comparison allows an estimate of the La and B site displacements, and we find that these sublattices are only slightly correlated with each other. Moreover, while the temperature dependence of the displacement parameters of the average sites from diffraction fit an Einstein model well, the temperature dependence of the La-B bond length distribution width requires at least two vibrational frequencies, corresponding to the La and B frequencies of the individual sites. XAFS data on EuB{sub 6} indicate that the situation is the same in the Eu compound. In addition, comparisons between data taken below and above the ferromagnetic transition temperature for EuB{sub 6} place stringent limits on the lattice involvement in the associated metal-insulator transition and the ensuing large magnetoresistance effect. This lack of lattice involvement in the magnetoresistance transition is in sharp contrast to the strong lattice involvement observed in the colossal magnetoresistance lanthanum manganese perovskites.

Booth, C.H.; Sarrao, J.L.; Hundley, M.F.; Cornelius, A.L.; Kwei, G.H.; Bianchi, A.; Fisk, Z.; Lawrence, J.M.

2001-01-30

77

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

78

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

79

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

80

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)

 
 
 
 
81

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

82

Improved association in a classical density functional theory for water  

Energy Technology Data Exchange (ETDEWEB)

We present a modification to our recently published statistical associating fluid theory-based classical density functional theory for water. We have recently developed and tested a functional for the averaged radial distribution function at contact of the hard-sphere fluid that is dramatically more accurate at interfaces than earlier approximations. We now incorporate this improved functional into the association term of our free energy functional for water, improving its description of hydrogen bonding. We examine the effect of this improvement by studying two hard solutes (a hard hydrophobic rod and a hard sphere) and a Lennard-Jones approximation of a krypton atom solute. The improved functional leads to a moderate change in the density profile and a large decrease in the number of hydrogen bonds broken in the vicinity of the hard solutes. We find an improvement of the partial radial distribution for a krypton atom in water when compared with experiment.

Krebs, Eric J.; Schulte, Jeff B.; Roundy, David [Department of Physics, Oregon State University, Corvallis, Oregon 97331 (United States)

2014-03-28

83

New Transfer Functions for Correcting Turbulent Water Vapour Fluxes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We address the problem of the high-frequency correction of water vapour fluxes measured by eddy covariance with a closed-path infrared gas analyser (IRGA). Different transfer functions are compared and evaluated at a forested (Vielsalm, Belgium) and an agricultural (Lonz,e, Belgium) site. Classical functions, usually applied to correct CO2 fluxes (Gaussian, Lorentzian), are found to be unsuited to water vapour cospectral corrections, being characterised by too sharp a decrease at high frequen...

Ligne, Anne; Heinesch, Bernard; Aubinet, Marc

2010-01-01

84

Water Quality Models with Different Functions of Exotech Radiometer Bands  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Surveillance of water quality by remote sensing technique can be pursued with advantage. An attempt has been made in this paper to obtain regional models of water quality of inland tanks and lakes. Stepwise multiple linear regression analysis between water quality parameters and several functions of Exotech radiometer band reflectance values, namely, bands alone, bands and their ratios, and, bands and their products are evaluated with respect to performance of the regression parameters. It is...

Rao, K. R.; Krishnan, R.; Chakraborty, A. K.; Deekshatulu, B. L.

1981-01-01

85

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

86

Water transport through functionalized nanotubes with tunable hydrophobicity.  

Science.gov (United States)

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. PMID:25399197

Moskowitz, Ian; Snyder, Mark A; Mittal, Jeetain

2014-11-14

87

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

88

Measured silicon displacement damage ratios support the need to replace the ASTM E-722 damage function with the NJOY calculated function  

Science.gov (United States)

Experiments with discrete silicon bipolar transistors exposed to 14 MeV neutrons and Sandia Pulsed Reactor (SPR III) fission type neutrons demonstrate that the silicon damage function listed in ASTM standard E-722 needs to be replaced by the NJOY calculated function to ensure simulation fidelity in testing for transient radiation effects in electronic devices. An annealing procedure applied between exposures ensured accurate damage comparisons between the two environments. Re-evaluation of the dosimetry foil cross sections and fluence determination methodology was also necessary to ensure that damage per neutron/sq cm could be evaluated properly. The results provide a clear distinction between the two damage predictions and show that the NJOY function is the one of choice.

Kelly, J. G.; Griffin, P. J.

89

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

90

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

91

A Simple Beta-Function Model for Soil-Water Repellency as a Function of Water and Organic Carbon Contents  

DEFF Research Database (Denmark)

Soil-water content (?) and soil organic carbon (SOC) are key factors controlling the occurrence and magnitude of soil-water repellency (WR). Although expressions have recently been proposed to describe the nonlinear variation of WR with ?, the inclusion of easily measurable parameters in predictive WR(?) models is still lacking. In this study, a simple empirical beta function was suggested to describe the effect of changing soil-water content on the change of WR given as apparent contact angle (?) measured by the molarity of ethanol droplet (MED) method. The beta function for predicting ?(?) is based on measurement of WR on air-dry soil and three additional model parameters: the water contents at which the maximum WR (highest ?) occurs and where WR ceases (? = 90 degrees), and the maximum ? value. The MED data for three data sets from literature comprising WR measurements across moisture conditions for 19 soils were used to test the model. The beta function successfully reproduced all the measured soil-water repellency characteristic, ?(?), curves. Significant correlations were found between model parameters and SOC content (1%-14%). The model was independently tested against data for further three soils and performed accurately for all three. Consequently, we suggest that the ?(?) model represents a useful strategy to predict the entire soil-water repellency characteristic curve, and thus potential risks for enhanced runoff and preferential (fingered) soil-water flow at given initial soil-water contents, from measurements of only air-dry soil-water repellency and SOC content.

Karunarathna, Anurudda Kumara; Kawamoto, Ken

2010-01-01

92

Water transport through functionalized nanotubes with tunable hydrophobicity  

Science.gov (United States)

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 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

2014-11-01

93

Displacer rod for use in a mechanical spectral shift reactor  

International Nuclear Information System (INIS)

A displacer rod for use in a mechanical spectral shift pressurized water nuclear reactor comprises a sectioned substantially hollow low neutron absorbing metal rod capable of displacing reactor coolant without absorbing a high amount of neutrons. The tubular sections preferably consist of stainless steel and Zircaloy tubing interconnected by a solid Zircaloy metal rod and may contain pellets for weighting the displacer rod. (author)

94

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

95

Intrinsic mean-square displacements in proteins  

Science.gov (United States)

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; Glyde, Henry R.

2012-07-01

96

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

97

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.

98

Abomasal displacement in cattle  

Directory of Open Access Journals (Sweden)

Full Text Available Left abomasal displacement can be treated among other techniques also with the rolling technique accompanied with a percutaneus paramedian abomasopexy using toggle pin fixators of cornel wood. This method is reliable, quick and cheap.

Zemlji? Borut

2003-01-01

99

Kinematics Problem: Displacement  

Science.gov (United States)

A bowling ball is lifted from rest onto a shelf by an external agent (position is in meters and time is in seconds). Rank the paths by the displacement of the bowling ball during the animations (greatest first).

Christian, Wolfgang; Belloni, Mario

2006-01-20

100

Displacement chromatography of biomolecules.  

Science.gov (United States)

Displacement chromatography was used for the preparative-scale separation of peptides, antibiotics, and proteins. The feed components were both purified and concentrated during the separation processes. The components of a peptide mixture were separated on a reverse-phase analytical column using 2-(2-butoxyethoxy) ethanol as the displacer. The use of organic modifiers in the carrier along with an elevated column temperature of 45 degrees C enabled the efficient separation of relatively hydrophobic peptides by displacement chromatography. In addition, the throughput of the process was significantly increased by carrying out the separation at an elevated flow-rate with no adverse effect on product purity. The antibiotic cephalosporin C was isolated from impurities in a fermentation broth using 2-(2-butoxyethoxy)ethanol as the displacer along with a step change in column temperature. The proteins cytochrome c and lysozyme were purified on a weak cation-exchanger column using cationic polymers as the displacers. While polymers of 60 and 20 kilodaltons were both found to be good displacers for these proteins, only the lower molecular weight polymer was readily removed from the column by standard regeneration techniques. PMID:3403648

Subramanian, G; Phillips, M W; Cramer, S M

1988-05-20

 
 
 
 
101

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

102

Bacterial diversity and ecological function in lake water bodies  

Directory of Open Access Journals (Sweden)

Full Text Available The healthy development of lake ecosystems is a global issue. Bacteria are not only an integral component of food webs, but also play a key role in controlling and regulating water quality in lake ecosystems. Hence, in order to provide some suggestions for maintaining the long-term and healthy development of lake ecosystems, this review discusses and analyses concepts and assessment of bacterial diversity, the distribution of bacteria communities, mechanisms of formation, and the ecological functions of such communities in lake water bodies. In total, there are 21 freshwater bacterial phyla typically found in lake waters at present. Among them, Proteobacteria, Cyanobacteria, Bacteroidetes, Actinobacteria and Verrucomicrobia are the most important. The Beijerinck and Baas-Becking perspective and the meta- community hypothesis suggest that bacterial community diversity and species distributions in lake water bodies are caused by the combinedaction of stochastic and determinate processes. Research on the function of lake bacteria has mainly focused on processes that bacteria are involved in, for example water quality and elemental biogeochemical cycles. Despite efforts over the past 10 years, knowledge on lake bacterial community diversity and function is still very limited. Lake bacterial ecology is still a young science, which restricts people further understanding of microbial communities in lake bodies. Future research is required on: (1 integrating bacterialphenotype, genotype, phylogeny and ecological features to define the concept of bacterial “species”; (2 the dispersal of bacteria between different locations at a regional scale; (3 bacterial community diversity and functional characteristics at the micro scale; (4 ecological theories and hypotheses of bacterial community diversity in lake ecosystems to improve the theoretical framework of microbial ecology.

Lijuan Ren

2013-07-01

103

Function of Serum Complement in Drinking Water Arsenic Toxicity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

104

Function and biotechnology of extremophilic enzymes in low water activity.  

Science.gov (United States)

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. PMID:22480329

Karan, Ram; Capes, Melinda D; Dassarma, Shiladitya

2012-01-01

105

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

106

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)

107

Point processes and stochastic displacement fields  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The effect of a stochastic displacement field on a statistically independent point process is analyzed. Stochastic displacement fields can be divided into two large classes: spatially correlated and uncorrelated. For both cases exact transformation equations for the two-point correlation function and the power spectrum of the point process are found, and a detailed study of them with important paradigmatic examples is done. The results are general and in any dimension. A par...

Gabrielli, Andrea

2004-01-01

108

Transport properties of water at functionalized molecular interfaces  

Science.gov (United States)

Understanding transport properties of solvent such as diffusion and viscosity at interfaces with biomacromolecules and hard materials is of fundamental importance to both biology and biotechnology. Our study utilizes equilibrium molecular dynamics simulations to calculate solvent transport properties at a model peptide and microarray surface. Both diffusion and selected components of viscosity are considered. Solvent diffusion is found to be affected near the peptide and surface. The stress-stress correlation function of solvent near the hard surface exhibits long time memory. Both diffusion and viscosity are shown to be closely correlated with the density distribution function of water along the microarray surface. PMID:19791920

Feng, Jun; Wong, Ka-Yiu; Dyer, Kippi; Pettitt, B. Montgomery

2009-01-01

109

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

110

Theoretical Investigations of Water Clusters, Ice Clathrates and Functionalized Nanoparticles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Nanosized structures are of intermediate size between individual molecules and bulkmaterials which gives them several unique properties. At the same time their relative limitedsizes make them suitable for studies by the methods of computational chemistry. In this thesiswater clusters, ice clathrates and functionalized metal-oxide nanoparticles have been studiedby quantum-chemical calculations and statistical thermodynamics. The stabilities of water clusters composed of up to 100 molecules hav...

Lenz, Annika

2009-01-01

111

Water molecules in clay minerals: Thermodynamic functions and hydration  

Science.gov (United States)

Thermodynamic functions and adsorption of water molecules are very important properties for clay minerals. Smectite MX-80 and mixed-layer illite-smectite ISCz-1 were selected. They were first carefully characterized (HRTEM with EDX analysis), revealing original results. Then, the thermodynamic properties of water in clay were obtained by (i) comparison of the thermodynamic properties of anhydrous and hydrated minerals, between 0 and 350 K (adiabatic calorimetry, solution isothermal calorimetry), and (ii) water vapor adsorption isotherms, between 300 and 380 K (magnetic suspension thermobalance). Solution isothermal calorimetry is used to determine the enthalpies of formation of the minerals (1 bar and 298 K). Comparison of the results, for the anhydrous and the hydrated minerals, leads to the enthalpies of hydration at 298 K. Adiabatic calorimetry measurements give the heat capacities of the minerals from 5 to 350 K. Entropies, enthalpies of formation and Gibbs free energies of formation, for the anhydrous and the hydrated minerals, and then, entropies of hydration, enthalpies of hydration and Gibbs free energies of hydration, between 0 and 350 K, are finally obtained. Comparison of two close hydration states leads to the entropy, the enthalpy and the Gibbs free energy of the adsorption reaction: H2O free - H2O adsorbed. The Cp(T) curve, for the heat capacity of water in clay - i.e., the difference between the heat capacities of the hydrated and the anhydrous minerals -, shows that water in clay is a glass at low temperature, undergoes one or two continuous glass transitions between 150 and 270 K, and behaves as free liquid water above 273 K. The two glass transitions might correspond to two types of water molecules: (i) first adsorbed water molecules, bound to the interlayer cations of the clay mineral; (ii) last adsorbed water molecules, not bound to the interlayer cations. In addition, water vapor adsorption isotherms are obtained from 298 to 378 K (magnetic suspension thermobalance) and well fitted with a BET type model (with three layers of adsorbed water molecules). The Gibbs free energy of the adsorption reaction and the Gibbs free energy of hydration, for any hydration state, can be determined. They are in agreement with the above calorimetric values. Gailhanou H., van Miltenburg J.C., Rogez J., Olives J., Amouric M., Gaucher E.C., Blanc P. (2007).Thermodynamic properties of anhydrous smectite, illite and illite-smectite. (Part 1) Geochim Cosmochim. Acta 71, 5463-5473.

Gailhanou, Helène; Amouric, Marc; Olives, Juan; Rogez, Jacques; van Miltenburg, J. C.; van der Berg, G. J. K.; de Weireld, G.; Gaucher, E.; Blanc, P.

2010-05-01

112

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)

113

Optical displacement sensor  

Science.gov (United States)

An optical displacement sensor is disclosed which uses a vertical-cavity surface-emitting laser (VCSEL) coupled to an optical cavity formed by a moveable membrane and an output mirror of the VCSEL. This arrangement renders the lasing characteristics of the VCSEL sensitive to any movement of the membrane produced by sound, vibrations, pressure changes, acceleration, etc. Some embodiments of the optical displacement sensor can further include a light-reflective diffractive lens located on the membrane or adjacent to the VCSEL to control the amount of lasing light coupled back into the VCSEL. A photodetector detects a portion of the lasing light from the VCSEL to provide an electrical output signal for the optical displacement sensor which varies with the movement of the membrane.

Carr, Dustin W. (Albuquerque, NM)

2008-04-08

114

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

115

Compressed facade displacement maps.  

Science.gov (United States)

We describe an approach to render massive urban models. To prevent a memory transfer bottleneck we propose to render the models from a compressed representation directly. Our solution is based on rendering crude building outlines as polygons and generating details by ray-tracing displacement maps in the fragment shader. We demonstrate how to compress a displacement map so that a decompression algorithm can selectively and quickly access individual entries in a fragment shader. Our prototype implementation shows how a massive urban model can be compressed by a factor of 85 and outperform a basic geometry-based renderer by a factor of 40 to 80 in rendering speed. PMID:19147890

Ali, Saif; Ye, Jieping; Razdan, Anshuman; Wonka, Peter

2009-01-01

116

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

117

Military-induced displacement  

Directory of Open Access Journals (Sweden)

Full Text Available Since the fall of the former government, Iraqis have primarily fled their homes because of sectarian and generalised violence. However, counter-insurgency operations by the US military and their Iraqi allies continue to be a significant cause of death, destruction and internal displacement in parts of Iraq.

Dina Abou Samra

2007-06-01

118

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)

119

The Reliability of a Functional Agility Test for Water Polo  

Science.gov (United States)

Few functional agility tests for water polo take into consideration its specific characteristics. The preliminary objective of this study was to evaluate the reliability of an agility test for water polo players. Fifteen players (16.3 ± 1.8 years old) with a minimum of two years of competitive experience were evaluated. A Functional Test for Agility Performance (FTAP) was designed to represent the context of this sport. Several trials were performed to familiarize the athlete with the movement. Two experienced coaches measured three repetitions of the FTAP. Descriptive statistics, repeated measures analysis of variance (ANOVA), 95% limit of agreement (LOA), intraclass correlation coefficient (ICC) and standard error of measurements (SEM) were used for data analysis. It was considered that certain criteria of reliability measures were met. There was no significant difference between the repetitions, which may be explained by an effect of the evaluator, the ability of the players or fatigue (p > 0.05). The ICC average from evaluators was high (0.88). The SEM varied between 0.13 s and 0.49 s. The CV average considering each individual was near 6–7%. These values depended on the condition of measurement. As the FTAP contains some characteristics that create a degree of unpredictability, the same athlete may reach different performance results, increasing variability. An adjustment in the sample, familiarization and careful selection of subjects help to improve this situation and enhance the reliability of the indicators. PMID:25114745

Tucher, Guilherme; de Souza Castro, Flávio Antônio; Garrido, Nuno Domingos; Martins da Silva, António José Rocha

2014-01-01

120

Electrical conductivity of shocked water from density functional theory  

International Nuclear Information System (INIS)

We present Density Functional Theory (DFT) calculations of water in a region of phase space of interest in shock experiments. The onset of electrical conductivity in shocked water is determined by ionic conductivity, with the electron contribution dominating at higher pressures. The ionic contribution to the conduction is calculated from proton diffusion (Green-Kubo formula) and the electronic contribution is calculated using the Kubo-Greenwood formula (1). The calculations are performed with VASP, a plane-wave pseudopotential code. At 2000K and a density of 2.3 g/cc, we find a significant dissociation of water into H, OH, and H3O, not only intermittent formation of OH - H3O pairs as suggested earlier for 2000 K and 1.95 g/cc (2). The calculated conductivity is compared to experimental data (3). Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Safety Administration under contract DE-AC04-94AL85000. This project was supported by the Sandia LDRD office. (1) M. P. Desjarlais, J. D. Kress, and L. A. Collins; Phys. Rev. B 66, 025401 (2002). (2) E. Schwegler, et al. Phys. Rev. Lett. 87, 265501 (2001). (3) P.M. Celliers, et. al. Physics of Plasmas 11, L41 (2004).

 
 
 
 
121

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

122

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

123

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

124

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

125

Physiological evidence that pyramidal neurons lack functional water channels.  

Science.gov (United States)

The physiological conditions that swell mammalian neurons are clinically important but contentious. Distinguishing the neuronal component of brain swelling requires viewing intact neuronal cell bodies, dendrites, and axons and measuring their changing volume in real time. Cultured or dissociated neuronal somata swell within minutes under acutely overhydrated conditions and shrink when strongly dehydrated. But paradoxically, most central nervous system (CNS) neurons do not express aquaporins, the membrane channels that conduct osmotically driven water. Using 2-photon laser scanning microscopy (2PLSM), we monitored neuronal volume under osmotic stress in real time. Specifically, the volume of pyramidal neurons in cerebral cortex and axon terminals comprising cerebellar mossy fibers was measured deep within live brain slices. The expected swelling or shrinking of the gray matter was confirmed by recording altered light transmittance and by indirectly measuring extracellular resistance over a wide osmotic range of -80 to +80 milliOsmoles (mOsm). Neurons expressing green fluorescent protein were then imaged with 2PLSM between -40 and +80 mOsm over 20 min. Surprisingly, pyramidal somata, dendrites, and spines steadfastly maintained their volume, as did the cerebellar axon terminals. This precluded a need for the neurons to acutely regulate volume, preserved their intrinsic electrophysiological stability, and confirmed that these CNS nerve cells lack functional aquaporins. Thus, whereas water easily permeates the aquaporin-rich endothelia and glia driving osmotic brain swelling, neurons tenatiously maintain their volume. However, these same neurons then swell dramatically upon oxygen/glucose deprivation or [K+]0 elevation, so prolonged depolarization (as during stroke or seizure) apparently swells neurons by opening nonaquaporin channels to water. PMID:16723408

Andrew, R David; Labron, Mark W; Boehnke, Susan E; Carnduff, Lisa; Kirov, Sergei A

2007-04-01

126

The oxygen isotope partition function ratio of water and the structure of liquid water  

Science.gov (United States)

By means of the CO2-equilibration technique, the temperature dependence and absolute values of the oxygen isotope partition function ratio of liquid water have been determined, often at 1?? intervals, from -2 to 85??. A linear relationship between In (Q2/Q1) (H2O) and T-1 was obtained that is explicable in terms of the Bigeleisen-Mayer theory of isotopic fractionation. The data are incompatible with conventional, multicomponent mixture models of water because liquid water behaves isotopically as a singly structured homogeneous substance over the entire temperature range studied. A two-species model of water is proposed in which approximately 30% of the hydrogen bonds in ice are broken on melting at 0?? and in which this per cent of monomer changes by only a small amount over the entire liquid range. Because of the high precision and the fundamental property determined, the isotopic fractionation technique is particularly well suited to the detection of thermal anomalies. No anomalies were observed and those previously reported are ascribed to under-estimates of experimental error.

O'Neil, J.R.; Adami, L.H.

1969-01-01

127

Nonlinear Brownian motion - mean square displacement  

Directory of Open Access Journals (Sweden)

Full Text Available The stochastic dynamics of self-propelled Brownian particles is studied by means of the Langevin and the Fokker-Planck approach. We model the driving by a nonlinear friction function which has a negative part at small velocities, leading to active Brownian motion of the particles. The mean square displacement is estimated analytically and compared with numerical simulations.

W.Ebeling

2004-01-01

128

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

129

Effect of connate-water saturation, oil viscosity, and matrix permeability on rate of gravity drainage during immiscible and miscible displacement tests in matrix-fracture experimental model  

Energy Technology Data Exchange (ETDEWEB)

There has been a substantial increase in interest regarding miscible injection of carbon dioxide (CO{sub 2}) for the purpose of enhanced oil recovery in conventional oil reservoirs. However, due to presumed low performance efficiency, naturally fractured reservoirs, which are among the largest oil reserves in the world, are considered bad candidates for this process. This paper presented the results of an experimental study on the effect of connate water saturation, matrix permeability, and oil viscosity on the performance of gravity drainage from the matrix into fracture when it was surrounded by a CO{sub 2}-filled fracture. An experimental model was used under different operating pressures to study both immiscible and miscible conditions. Experiments were conducted using synthetic oil and light crude oil in two Berea cores having large differences in permeability. The effect of connate water saturation was also examined by performing experiments in an initially brine saturated Berea core and comparing the results with those obtained when the core was 100 per cent saturated with oil. The paper described the laboratory study including the materials, experimental setup, and experimental procedure. Results were presented for the effect of connate water saturation; effect of oil viscosity; effect of matrix permeability; and oil in place. It was concluded that matrix permeability has a significant effect on the rate of gravity drainage when CO{sub 2} is injected under immiscible conditions. 11 refs., 1 tab., 7 figs.

Torabi, F.; Asghari, K. [Regina Univ., SK (Canada)

2009-07-01

130

Reduction of left ventricular longitudinal global and segmental systolic functions in patients with hypertrophic cardiomyopathy: Study of two-dimensional tissue motion annular displacement  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The early detection of abnormal left ventricular systolic functions in patients with hypertrophic cardiomyopathy (HCM) remains a challenge. The aim of this study was to identify a novel method for the assessment of left ventricular systolic function in patients with HCM. A total of 65 patients with HCM were included in this study. The patients were divided into obstructive HCM (HOCM; 16 cases) and non-obstructive HCM (NOHCM; 49 cases) groups. The healthy control group comprised 48 participant...

Liu, Liwen; Tuo, Shengjun; Zhang, Jianlei; Zuo, Lei; Liu, Fang; Hao, Lili; Sun, Yandan; Yang, Liping; Shao, Hong; Qi, Wei; Zhou, Xiaodong; Ge, Shuping

2014-01-01

131

Simulation of turbostatic structure by the probability function of a displacement of carbon layer planes; Tanso amimen no zure no kakuritsu kansu wo mochiita ranso kozo simulation  

Energy Technology Data Exchange (ETDEWEB)

The probability functions for the 1st and 2nd nearest neighbor layers were calculated for the carbon black, the Fourier coefficients A{sub n}(hk) of which were obtained by Houska and Warren. As a result, the probability function indicating the AB stacking was obtained and it was in good agreement with the positions of carbon atoms in an unit cell of hexagonal system. Twist angle between the adjacent layers due to the turbostratic structure was estimated to be 1.14{degree} from the probability function of the 1st nearest neighbor layer. The simulation of turbostratic structure based on the result shows the moire patterns indicating the existence of the island structure of AA stacking with the equi-distance of ca. 11nm. 6 refs., 6 figs., 1 tab.

Fujimoto, H. [Osaka Gas Co. Ltd., Osaka (Japan)

1995-09-10

132

Linking Species Traits to the Abiotic Template of Flowing Waters: Contrasting Eco physiologies Underlie Displacement of Zebra Mussels by Quagga Mussels in a Large River-Estuary  

Science.gov (United States)

The St. Lawrence River-Estuary was the gateway of entry for dreissenids to North America and holds some of the oldest populations. The St. Lawrence also has four distinct physical-chemical water masses (a regional scale abiotic template) that both species inhabit. Despite their ecological similarities, quagga mussels are supplanting zebra mussels in much of their shared range. In order to try to better understand the changing distributions of these two species we compared glycogen, shell mass and tissue biomass in each of the water masses. This comparative physiological combined with experimental approaches (estuarine salinity experiments and reciprocal transplants) showed that while quagga mussels should dominate in most habitats, that abiotic/bioenergetic constraints in two regions (the Ottawa River plume and the freshwater-marine transition zone) might prevent them from dominating these locations. These findings are an example of how the interaction of landscape scale abiotic heterogeneity and a species-specific physiology can have strong impacts of distribution of biota large rivers.

Casper, A. F.

2005-05-01

133

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

134

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)

135

Hyoid Displacement in Post-Treatment Cancer Patients: Preliminary Findings  

Science.gov (United States)

Purpose: Dysphagia after head and neck cancer treatment is a health care issue; in some cases, the cause of death is not cancer but, rather, the passage of food or liquid into the lungs. Hyoid displacement is known to be important to safe swallowing function. The purpose of this study was to evaluate hyoid displacement after cancer treatment.…

Zu, Yihe; Yang, Zhenyu; Perlman, Adrienne L.

2011-01-01

136

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

137

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

138

Surface-tension-driven liquid liquid displacement in a capillary  

Science.gov (United States)

This paper presents theoretical and experimental studies of the surface-tension-driven, two-immiscible liquid-liquid displacement in a horizontal capillary. Using the dynamic contact angle approach, a one-dimensional mathematical model is developed to describe the capillary displacement of a fixed liquid column by another liquid that continuously flows into the capillary by surface tension. Experiments for a water column displaced by silicon oil were carried out to examine the effect of the water column length and capillary diameter on the displacement dynamics. It was found that a faster and longer displacement is achieved for a shorter water column in a larger capillary. The theoretical predictions agree reasonably well with the experimental studies conducted for the capillary displacement of the silicon oil-water interface. In addition, for a single liquid capillary flow, dimensionless Pi groups are derived using the similarity analysis. It is demonstrated that using the derived Pi groups, the experimental data for the displacement of silicon oil of various viscosities in capillaries of various diameters can collapse into one curve that is consistent with the Washburn equation.

Chan, W. K.; Yang, C.

2005-09-01

139

Mathematic Model of Green Function with Two-Dimensional Free Water Surface  

Directory of Open Access Journals (Sweden)

Full Text Available Adopting complex number theory, a mathematic model of Green function is built for two dimension free water surface, and an analytic expression of Green function is obtained by introducing two parameters. The intrinsic properties of Green function are discussed on vertical line and horizontal line. At last, the derivation expression of Green function is obtained from the formula of Green function.

Sujing Jin

2013-07-01

140

OIL DISPLACEMENT IN MISCIBLE CONDITION  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Ivanka Juttner

1997-01-01

 
 
 
 
141

Asymmetry in Reproductive Character Displacement  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 stat...

Jang, Yikweon

2008-01-01

142

MRI of displaced meniscal fragments  

Energy Technology Data Exchange (ETDEWEB)

A torn meniscus frequently requires surgical fixation or debridement as definitive treatment. Meniscal tears with associated fragment displacement, such as bucket handle and flap tears, can be difficult to recognize and accurately describe on MRI, and displaced fragments can be challenging to identify at surgery. A displaced meniscal fragment can be obscured by synovium or be in a location not usually evaluated at arthroscopy. We present a pictorial essay of meniscal tears with displaced fragments in patients referred to a pediatric hospital in order to increase recognition and accurate interpretation by the radiologist, who in turn can help assist the surgeon in planning appropriate therapy. (orig.)

Dunoski, Brian [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States); Children' s Hospital of Michigan, Department of Radiology, Detroit, MI (United States); Zbojniewicz, Andrew M.; Laor, Tal [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States)

2012-01-15

143

Estimation of average to maximum displacement ratio by using fault displacement-distance profiles  

Science.gov (United States)

Fault displacement is an important factor in the study of discontinuous deformation. Considering that the values of average displacement (Dav) and maximum displacement (Dmx) are linearly related by Dav = ?Dmx, we calculate the values of ? estimated from 205 published displacement-distance profiles. The following results are obtained: (a) the value of ? is largest for the mesa-type or flat-topped (M-type) profiles; (b) the value of ? increases when ductile (continuous) deformation is added to the displacement profile; (c) generally, the value of ? for a linked fault array is smaller than that for segmented faults in the array, i.e., the value of ? changes with fault evolution, and at the stage where linkage occurs, the value of ? becomes smaller; (d) the simulation results indicate that for an ellipse function, the value of ? varies from 0.667 to 0.785. For trapezoid (M-type) profiles, the value of ? is from 0.5 to 1, depending on the ratio of the upper base to the lower base. For best fit polynomial curves, the value of ? can be less than 0.5; (e) the values of ? more frequently observed in the published profiles are between 0.6 and 0.7; the average value is 0.6023 and the standard deviation 0.1123. These data indicate that the displacement-distance profiles are hybrids from the triangular profile to the elliptical or mesa profile. The average value (0.6023) would be useful to determine the average displacement in cases where not enough displacement data can be obtained. Finally, the value change of ? with fault evolution can be used to quantitatively evaluate the level of interaction between segmented faults.

Xu, S.-S.; Nieto-Samaniego, A. F.; Alaniz-Álvarez, S. A.

2014-12-01

144

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 SciELO Brazil | Language: Portuguese Abstract in portuguese 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.

145

Canal Lock Displacement  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this project we determine the time needed for a pump to raise the water level in a canal lock in order for a boat to continue upstream. Using calculus methods and elementary physics, it was determined that it would take roughly 5 minutes for a single 60 horsepower pump to raise the water level the required 10 feet. We conclude that the lock is fairly efficient but offer some suggestions to increase the time efficiency of the lock system.

Rick Blanton

2010-01-01

146

Functional Design of the National Monitoring Drinking Water Quality  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The laboratory of Water and Drinking Water Research of the National Institute of Public Health and Environmental Protection (RIVM) is responsible for the monitoring of the drinking water quality in the Netherlands. For this activity an information system will be developed to registrate the quality data and to report to the government. This design is the first part of an overall information system containing several aspects of the public watersupply. Other information w...

Pjtm, Puijenbroek

2012-01-01

147

Dispossession and displacement in Libya  

Directory of Open Access Journals (Sweden)

Full Text Available Inability to access pre-displacement housing, land and property poses a significant obstacle to the achievement of durable solutions for most IDPs in Libya. Displacement and dispossession cannot be separated from the legacy of the Gaddafi era.

Rhodri C Williams

2012-06-01

148

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

2014-11-22

149

Inherent Properties of Two Dimension Green Function with Linear Boundary Condition of Free Water Surface  

Directory of Open Access Journals (Sweden)

Full Text Available A mathematic model of Green function is build for two dimension free water surface. The analytic expression of Green function is obtained by introducing a parameter of complex number. The intrinsic properties of Green function are discussed for the special parameter values. The real and imaginary parts of H function are shown in the paper.

Xing Wang

2013-07-01

150

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

151

Data assimilation with soil water content sensors and pedotransfer functions in soil water flow modeling  

Science.gov (United States)

Soil water flow models are based on a set of simplified assumptions about the mechanisms, processes, and parameters of water retention and flow. That causes errors in soil water flow model predictions. Soil water content monitoring data can be used to reduce the errors in models. Data assimilation (...

152

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

153

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

154

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

155

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)

156

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

157

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

158

Is Fibular Fracture Displacement Consistent with Tibiotalar Displacement?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2010-01-01

159

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

160

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

 
 
 
 
161

Thermal Care of Functional Dyspepsia Based on Bicarbonate-Sulphate-Calcium Water: A Sequential Clinical Trial  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Drug treatment of functional dyspepsia is often unsatisfactory. We assessed the efficacy of a bicarbonate-sulphate-calcium thermal water cycle of 12 days, in patients with functional dyspepsia. Patients with functional dyspepsia were sent by their general practitioners to 12 days of treatment with thermal water, 200–400 ml in the morning, at temperature of 33°C (91.4 F) and were evaluated on a strict intention to treat basis. Four efficacy endpoints were analyzed as follows: (i) reduction ...

Ferruccio Bonino; Brunetto, Maurizia R.; Filippo Oliveri; Nadia Rocca; Federico Dioni; Giuseppe Rocca

2007-01-01

162

Water ecosystem service function assessment based on eco-hydrological process in Luanhe Basin,China  

Science.gov (United States)

At present, ecological water are mainly occupied by a rapid development of social economic and population explosion, which seriously threat the ecological security and water security in watershed and regional scale. Due to the lack of a unified standard of measuring the benefit of water resource, social economic and ecosystem, the water allocation can't take place in social economic and ecosystem. The function which provided by water in terrestrial, aquatic and social economic system can be addressed through water ecosystem service function research, and it can guide the water allocation in water resource management. The function which provided by water in terrestrial, aquatic and social economic system can be addressed through water ecosystem service function research, and it can guide the water allocation in water resource management. Throughout the researches of water ecosystem service, a clear identification of the connection of water ecosystem service function has not been established, and eco-economic approach can't meet the practical requirement of water allocation. Based on "nature-artificiality" dual water cycle theory and eco-hydrological process, this paper proposes a connection and indicator system of water ecosystem service function. In approach, this paper establishes an integrated assessment approach through prototype observation technology, numerical simulation, physical simulation and modern geographic information technology. The core content is to couple an eco-hydrological model, which involves the key processes of distributed hydrological model (WEP), ecological model (CLM-DGVM), in terms of eco-hydrological process. This paper systematically evaluates the eco-hydrological process and evolution of Luanhe Basin in terms of precipitation, ET, runoff, groundwater, ecosystem's scale, form and distribution. According to the results of eco-hydrological process, this paper assesses the direct and derived service function. The result indicates that the general service function of 2010 has minor increase than 2007, however the general function of two years are in common level; Compare with different region, the upstream, middle stream and downstream indicates "worse", "common" and "good" level respectively. The first three derived functions are leisure, offer products and industrial water use. In the end, this paper investigates the evolution of water ecosystem service function under rising temperatures and elevated CO2 concentration scenarios in Luanhe Basin through eco-hydrological model. The results elaborate that the water ecosystem service functions would decline when temperature rising, and warming to 1.5 degree is the mutation point of sharp drop; Increased CO2 concentration scenario will improve the direct service function in the whole Basin; under the overlying scenario, different region shows different results, the direct service function will increased in upstream and middle stream, direct service function will drop in downstream. A comprehensive analysis indicates that the rising temperature is the major driven of water ecosystem service function in Luanhe Basin.

Zhang, C.; Hao, C.; Qin, T.; Wang, G.; Weng, B.

2012-12-01

163

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

164

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

165

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)

166

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.

167

A novel linear displacement sensor  

Science.gov (United States)

With development of time grating technology in the past 10 years, the theory of using time to measure spatial displacement has been completed greatly. In the study of time grating, one novel linear displacement sensor is proposed based on the measurement principles of time grating. The measurement principles of linear displacement are similar to that of angular displacement. Both of them need one endless coordinate with uniform velocity. The theory of linear AC motor is used, and the three-phase winding with equal division space of 120° and three-phase exciting signal with uniform time are utilized to generate the endless moving coordinate with uniform velocity. The magnetic traveling wave arises from the left endpoint and disappears in the right endpoint, and it travels pole pitch distance of W during the periodic time of T with the uniform velocity. When magnetic traveling wave passes by the static probe and the moving probe, the electric signals will be induced on the winding, respectively. Therefore, the linear displacement can be achieved by comparing the phase between the two output induced signals from he static probe and the moving probe. Furthermore, in order to improve the machining technique, four kinds of winding framework are designed to employ. The experimental results show that advantages and disadvantages both exist in the design methods and the precision of experiment results reaches +/-2µm. The next study plan is to choose the most excellent design method through further experiments and improve the precision of displacement sensor greatly.

Yang, Ji-sen; Zhang, Jing; Chen, Xi-hou; Zhang, Tian-heng

2011-12-01

168

Evaluation of Parametric Pedotransfer Functions for Estimating Soil Water Characteristic Curve in Fars Province  

Directory of Open Access Journals (Sweden)

Full Text Available Soil water characteristic curve shows the relationship between soil water content and matric suction, which has an important role in water movement in the soil. The measurement of this curve is expensive and time-consuming in laboratory; therefore, many methods have been proposed for its estimation including pedotransfer functions. By using the pedotransfer functions, soil water characteristic curve can be estimated based on other easily measured soil physicochemical properties. Parametric pedotransfer functions have been offered for parameters of the existing soil water characteristic curve models. In this study, 12 internal and external parametric pedotransfer functions of Brooks and Corey, Campbell and van Genuchten models were used and evaluated for 30 top soil samples in Fars province. To this end, the soil water characteristic curve and other necessary soil properties were measured, and then all soils according to the texture were divided into three groups of fine, medium and course textures. The results showed that the parametric pedotransfer functions of van Genuchten model were better than the other models, beacause of the better fit of this model to the measured data. Also, the results demonstrated that the parametric pedotransfer functions of Wosten et al. were the most appropriate method for estimating the soil water characteristic curve for the selected soils in Fars province, and that internal pedotransfer functions were not appropriate

H. R. Fooladmand

2012-03-01

169

Bladder displacement due to dilated veins  

International Nuclear Information System (INIS)

The authors report three children who demonstrated unilateral displacement of the urinary bladder associated with acute iliofemoral vein thrombosis. The displacement is caused by dilated collateral veins. The anatomic considerations are discussed. Other causes for bladder displacement are listed. (orig.)

170

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

171

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

172

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...

173

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

174

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

175

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)

176

Measurement of the Cryomodule cold mass displacement using the WPM  

International Nuclear Information System (INIS)

A method for indirect measurement of the cryomodule cold mass displacement using the wire position monitor (WPM) is developed in the work. An analytical expression for the transfer functions of the test signal is obtained for the WPM. Dependences of the x, y coordinates of the cold mass displacement upon the amplitude of the electrode signals and the parameters of the monitor are determined. The displacement functions are applicable in the deviation range r ?0,82 R and do not depend upon the test signal amplitude. The results are of interest for the monitoring of the beam position and the cryomodule cold mass displacement in new-generation accelerators like ILC, NICA, FAIR and XFEL

177

Function and biotechnology of extremophilic enzymes in low water activity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 te...

Karan Ram; Capes Melinda D; DasSarma Shiladitya

2012-01-01

178

Hysteresis of Soil Point Water Retention Functions Determined by Neutron Radiography  

Science.gov (United States)

Soil point water retention functions are needed for modeling flow and transport in partially-saturated porous media. Such functions are usually determined by inverse modeling of average water retention data measured experimentally on columns of finite length. However, the resulting functions are subject to the appropriateness of the chosen model, as well as the initial and boundary condition assumptions employed. Soil point water retention functions are rarely measured directly and when they are the focus is invariably on the main drying branch. Previous direct measurement methods include time domain reflectometry and gamma beam attenuation. Here we report direct measurements of the main wetting and drying branches of the point water retention function using neutron radiography. The measurements were performed on a coarse sand (Flint #13) packed into 2.6 cm diameter x 4 cm long aluminum cylinders at the NIST BT-2 (50 ?m resolution) and ORNL-HFIR CG1D (70 ?m resolution) imaging beamlines. The sand columns were saturated with water and then drained and rewetted under quasi-equilibrium conditions using a hanging water column setup. 2048 x 2048 pixel images of the transmitted flux of neutrons through the column were acquired at each imposed suction (~10-15 suction values per experiment). Volumetric water contents were calculated on a pixel by pixel basis using Beer-Lambert’s law in conjunction with beam hardening and geometric corrections. The pixel rows were averaged and combined with information on the known distribution of suctions within the column to give 2048 point drying and wetting functions for each experiment. The point functions exhibited pronounced hysteresis and varied with column height, possibly due to differences in porosity caused by the packing procedure employed. Predicted point functions, extracted from the hanging water column volumetric data using the TrueCell inverse modeling procedure, showed very good agreement with the range of point functions measured within the column using neutron radiography. Extension of these experiments to 3-dimensions using neutron tomography is planned.

Perfect, E.; Kang, M.; Bilheux, H.; Willis, K. J.; Horita, J.; Warren, J.; Cheng, C.

2010-12-01

179

Dispersive effects of transverse displacements of SLC Arc magnets  

International Nuclear Information System (INIS)

The SLC Arc magnets are subject to random displacements and field errors resulting in unpredictable transverse displacement of the central trajectory from that of the design. The chosen method of correcting this perturbed trajectory in the SLC Arcs utilizes mechanical movement of the combined function magnets which compose the Arc transport lines. Here we present the results of a recent investigation substantiating the earlier results which led to the adoption of this method

180

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

 
 
 
 
181

Mountain border area of eastern Serbia in the function of the spring zones of surface water  

Directory of Open Access Journals (Sweden)

Full Text Available Border mountain area of eastern Serbia has a distinct potential and importance in the function of surface water sources, which are characterized by range of geographical and environmental characteristics and similarities determined by mountainous character of the territory. For the purposes of this paper, border area of Serbia towards Bulgaria is provisionally determined by iso-border of 25 km. On the defined area of eastern Serbia there are 11 individual territories allocated in the function of being surface water source. Key objects for the realization of the goals of rational and functional exploitation of surface water sources are accumulations. They are the link between the system of surface water sources and water supply system.

Milin?i? Miroljub

2012-01-01

182

Functionalized gold nanoparticles for the detection of arsenic in water.  

Science.gov (United States)

Gold nanoparticles are attractive as sensing materials because of their size and shape are related with their optical properties. The color change produced by the aggregation of functionalized AuNPs allows the detection of arsenic at low levels. A simple, cheap and fast analytical procedure to perform arsenic determination using functionalized gold nanoparticles (AuNPs) and VIS spectrometry as a detection technique is studied. Three different synthesis procedures to obtain the AuNPs and two different functionalization modes were studied. AuNPs functionalized with GSH-DTT-CYs-PDCA were selected as the most adequate. The correlation between the decrease in the absorbance signal and the arsenic concentration was good in the 2-20 µg l(-1)interval. Repeatability, expressed as average of RSD (%), obtained for the different arsenic concentrations studied was 0.6%. The average value of the analytical recovery was 99.7%. The detection and quantifications limits were 2.5 and 8.4 µg l(-1) respectively. These limits are sufficient to detect World Health Organization's guideline value of 10 µg l(-1). PMID:24274297

Domínguez-González, R; González Varela, L; Bermejo-Barrera, P

2014-01-01

183

Digital image correlation: displacement accuracy estimation  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this collaborative work is to study the uncertainties associated with Digital Image Correlation techniques (DIC. More specifically, the link between displacement uncertainties and several correlation parameters chosen by the user and relative to the image analysis software and several image characteristics like speckle size and image noise is emphasized. A previous work [1] has been done for situations with spatially fluctuating displacement fields which dealt with mismatch error linked to the discrepancy between the adopted shape function and the real displacement field in the subset. This present work is focused on the ultimate error regime. To ensure that there is no mismatch error, synthetic images of plane rigid body translation have been analysed. DIC softwares developed by or used in the French community were used to study a large number of settings. The first observations are: (a bias amplitude is almost always insensitive to the subset size, (b DIC formulations can be split up into two families. For the first one, the bias amplitude increases with the noise while it remains constant for the second one. For both families, the mean value of the random error increases with the noise level and with the inverse of the subset size. Furthermore, the random error decreases with the radius of the speckle for the first family, while it increases for the second one. These two different behaviours of the tested DIC package are probably due to their underlying DIC formulation (interpolation, correlation criteria, optimisation process.

Wattrisse B.

2010-06-01

184

A computationally efficacious free-energy functional for studies of inhomogeneous liquid water  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present an accurate equation of state for water based on a simple microscopic Hamiltonian, with only four parameters that are well-constrained by bulk experimental data. With one additional parameter for the range of interaction, this model yields a computationally efficient free-energy functional for inhomogeneous water which captures short-ranged correlations, cavitation energies and, with suitable long-range corrections, the non-linear dielectric response of water, mak...

Sundararaman, Ravishankar; Letchworth-weaver, Kendra; Arias, T. A.

2011-01-01

185

Thermal properties calculated from measured water content as a function of depth in porcine skin.  

Science.gov (United States)

In order to develop a realistic tissue water boiling routine for a mathematical model of burn development, it was necessary to know the water content and the thermal properties of skin as a function of depth. Split thickness skin samples were obtained from several pigs using an air-powered dermatome. Alternate segments of these skin slices were processed for skin water content determination and for histopathologic measurements of skin thickness. Tissue samples were weighed, dried and subsequently weighed again using standardized methods to determine tissue water content. In some instances the volume of tissue was also determined to allow the calculation of tissue density. Given a table of measured values of water content as a function of skin thickness, a least-squares cubic polynomial was fitted to the data and water content as a function of depth was computed from the following formula: w(T-d) = T/d x (WT-WT-d)+WT-d where T is the total thickness of a skin slice, WT is the fraction of water computed from the cubic equation, d is the thickness of the skin slice at a depth T-d, and WT-d is the fraction of water above the thin slice. Stratum corneum hydration was calculated from measured ambient relative humidity based on a relationship previously described by Rushmer et al. (1966). Skin thermal properties as a function of depth were calculated using the formulation of Cooper and Trezek (1971).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3454688

Knox, F S; Wachtel, T L; McCahan, G R; Knapp, S C

1986-12-01

186

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

187

A priori classical density functionals of water: toward first principles exploration of aqueous based energy systems  

Science.gov (United States)

The microscopic structure of inhomogeneous water plays a critical role in the properties of a wide variety of important energy systems including fuel cells and photoelectrochemical cells. Joint density functional theory has proven to be an efficient tool for the quantum-mechanical modeling of systems such as Pt electrodes in the presence of water, but requires theories for water which go beyond semi-empirical continuum solvation models, and accurate models for the coupling between water and electronic systems ootnotetextK. L. Weaver et al, to be presented at APS March Meeting 2011. Toward this end, we present a new density-functional description of liquid water capable of predicting interatomic correlation functions, the linear and nonlinear dielectric response, and solvation energies without empirical fit parameters. The functional itself is built upon the site-potential representation of the ideal gas, a hard sphere reference fluid for the repulsive correlations, and an equation of state that reproduces the bulk properties of water over the entire extent of its liquid phase. Hydrogen bonding, the local tetrahedral structure and orientational correlations are captured a priori by a density-functional reformulation of the Kirkwood model for the dielectric constant.

Sundararaman, Ravishankar; Letchworth Weaver, Kendra; Arias, Tomas

2011-03-01

188

Displacement based seismic design methods  

International Nuclear Information System (INIS)

A research effort was undertaken to determine the need for any changes to USNRC's seismic regulatory practice to reflect the move, in the earthquake engineering community, toward using expected displacement rather than force (or stress) as the basis for assessing design adequacy. The research explored the extent to which displacement based seismic design methods, such as given in FEMA 273, could be useful for reviewing nuclear power stations. Two structures common to nuclear power plants were chosen to compare the results of the analysis models used. The first structure is a four-story frame structure with shear walls providing the primary lateral load system, referred herein as the shear wall model. The second structure is the turbine building of the Diablo Canyon nuclear power plant. The models were analyzed using both displacement based (pushover) analysis and nonlinear dynamic analysis. In addition, for the shear wall model an elastic analysis with ductility factors applied was also performed. The objectives of the work were to compare the results between the analyses, and to develop insights regarding the work that would be needed before the displacement based analysis methodology could be considered applicable to facilities licensed by the NRC. A summary of the research results, which were published in NUREG/CR-6719 in July 2001, is presented in this paper. (author)

189

DISPLACEMENT BASED SEISMIC DESIGN METHODS  

International Nuclear Information System (INIS)

A research effort was undertaken to determine the need for any changes to USNRC's seismic regulatory practice to reflect the move, in the earthquake engineering community, toward using expected displacement rather than force (or stress) as the basis for assessing design adequacy. The research explored the extent to which displacement based seismic design methods, such as given in FEMA 273, could be useful for reviewing nuclear power stations. Two structures common to nuclear power plants were chosen to compare the results of the analysis models used. The first structure is a four-story frame structure with shear walls providing the primary lateral load system, referred herein as the shear wall model. The second structure is the turbine building of the Diablo Canyon nuclear power plant. The models were analyzed using both displacement based (pushover) analysis and nonlinear dynamic analysis. In addition, for the shear wall model an elastic analysis with ductility factors applied was also performed. The objectives of the work were to compare the results between the analyses, and to develop insights regarding the work that would be needed before the displacement based analysis methodology could be considered applicable to facilities licensed by the NRC. A summary of the research results, which were published in NUREGICR-6719 in July 2001, is presented in this paper

190

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

191

Integrated control and health monitoring capacitive displacement sensor development task. Orbit transfer rocket engine technology program  

Science.gov (United States)

The development of a miniature multifunction turbomachinery shaft displacement sensor using state-of-the-art non-contract capacitive sensing technology is described. Axial displacement, radial displacement, and speed are sensed using a single probe within the envelope normally required for a single function. A survey of displacement sensing technology is summarized including inductive, capacitive, optical and ultrasonic techniques. The design and operation of an experimental triple function sensor is described. Test results are included showing calibration tests and simultaneous dynamic testing of multiple functions. Recommendations for design changes are made to improve low temperature performance, reliability, and for design of a flight type signal conditioning unit.

Collamore, Frank N.

1989-01-01

192

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

193

International Space Station USOS Potable Water Dispenser On-Orbit Functionality Versus Design  

Science.gov (United States)

The International Space Station (ISS) currently provides potable water dispensing for rehydrating crewmember food and drinking packages. There is one system located in the United States On-orbit Segment (USOS) and one system in the Russian Segment. Shuttle mission STS-126 delivered the USOS Potable Water Dispenser (PWD) to ISS on ULF2; subsequent activation occurred on November 2008. The PWD is capable of supporting an ISS crew of six, but nominally supplies only half this crew size. The PWD design provides incremental quantities of hot and ambient temperature potable water to US food and beverage packages. PWD receives iodinated water from the US Water Recovery System (WRS) Fuel Cell Water Bus, which feeds from the Water Processing Assembly (WPA). The PWD removes the biocidal iodine to make the water potable prior to dispensing. A heater assembly contained within the unit supplies up to 2.0 L of hot water (65 to 93 ?C) every 30 min. During a single meal, this quantity of water supports three to four crewmembers? food rehydration and beverages. The unit design has a functional life expectancy of 10 years, with replacement of limited life items, such as filters. To date, the PWD on-orbit performance is acceptable. Since activation of the PWD, there were several differences between on-orbit functionality and expected performance of hardware design. The comparison of on-orbit functionality to performance of hardware design is discussed for the following key areas: 1) microbial contamination, 2) no-dispense and water leakage scenarios, and 3) under-dispense scenarios.

Toon, Katherine P.; Lovell, Randal W.

2010-01-01

194

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

195

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

196

Morphology and functions of astrocytes cultured on water-repellent fractal tripalmitin surfaces.  

Science.gov (United States)

In the brain, astrocytes play an essential role with their multiple functions and sophisticated structure, as surrounded by a fractal environment which has not been available in our traditional cell culture. Water-repellent fractal tripalmitin (PPP) surfaces can imitate the fractal environment in vivo, so the morphology and biochemical characterization of astrocytes on these surfaces are examined. Water-repellent fractal PPP surface can induce astrocytes to display sophisticated morphology with smaller size of cell area, longer and finer filopodium-like processes, and higher morphological complexity. The super water-repellent fractal PPP surface with water contact angle of 150°?160° produces the maximal effects compared with other surfaces at lower water contact angles. The trends of characteristic protein expression, including that of nestin, vimentin, GFAP and glutamine synthetase, for astrocytes cultured on super water-repellent fractal PPP surfaces approximate more to in vivo pattern. The super water-repellent PPP surface also render astrocytes to perform more pronounced promotion of neurogenesis by increasing the release of nerve growth factor in a co-culture system. Altogether, our results suggest that the super water-repellent fractal PPP surface facilitates the astrocytes to mimic their in vivo performance, thus provides a closer-to-natural culture environment for experimental assessment of glial structure and functions. PMID:24894646

Hu, Wei-wei; Wang, Zhe; Zhang, Shan-shan; Jiang, Lei; Zhang, Jing; Zhang, Xiangnan; Lei, Qun-fang; Park, Hyun-Joo; Fang, Wen-jun; Chen, Zhong

2014-08-01

197

A multi-decadal meridional displacement of the Subpolar Front in the Newfoundland Basin  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Observations since the 1950s show a multi-decadal cycle of a meridional displacement of the Subpolar Front (SPF) in the Newfoundland Basin (NFB) in the North Atlantic. The SPF displacement is associated with corresponding variations in the path of the North Atlantic Current. We use the ocean general circulation model MPIOM with enhanced horizontal and vertical resolutions and forced with NCEP/NCAR reanalysis data to study the relation of the SPF displacement to Labrador Sea Water (LSW...

Nu?n?ez-riboni, I.; Bersch, M.; Haak, H.; Jungclaus, J. H.

2011-01-01

198

Effects of acidic functional groups on dielectric properties of sodium alginates and carrageenans in water.  

Science.gov (United States)

This study investigated the dielectric properties of sodium alginates and carrageenans in water at frequencies between 100MHz and 20GHz in regard to water-hydrocolloid interactions via acidic functional groups. Both sodium alginates and carrageenans showed conduction loss at lower frequencies and dielectric loss at higher frequencies. Reduction and desulfation of sodium alginates and carrageenans, which decreased the numbers of acidic functional groups, decreased their conduction loss. In addition, H(+)-form carrageenans showed the highest ionic conduction. Correlational analysis of dielectric properties and related physical parameters showed that the loss tangent (tan?) of the hydrocolloid solution was determined by the conductivity of the aqueous solution. Especially at pH below 2, strong H(+) conduction was associated with high tan? probably due to the Grotthuss mechanism. The molecular dynamics of free water and H(+), viscosity conditions were also suggested to be associated with dielectric property of water-hydrocolloid system. PMID:25439871

Tsubaki, Shuntaro; Hiraoka, Masanori; Hadano, Shingo; Okamura, Kei; Ueda, Tadaharu; Nishimura, Hiroshi; Kashimura, Keiichiro; Mitani, Tomohiko

2015-01-22

199

Energies of ions in water and nanopores within Density Functional Theory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Accurate calculations of electrostatic potentials and treatment of substrate polarizability are critical for predicting the permeation of ions inside water-filled nanopores. The {\\it ab initio} molecular dynamics method (AIMD), based on Density Functional Theory (DFT), accounts for the polarizability of materials, water, and solutes, and it should be the method of choice for predicting accurate electrostatic energies of ions. In practice, DFT coupled with the use of periodic...

Leung, Kevin; Marsman, Martijn

2007-01-01

200

Effect of head-out water immersion on vascular function in healthy subjects.  

Science.gov (United States)

Immersion in thermoneutral water increases cardiac output and peripheral blood flow and reduces systemic vascular resistance. This study examined the effects of head-out water immersion on vascular function. Twelve healthy middle-aged males were immersed during 60 min in the seated position, with water at the level of xiphoid. Local and central vascular tone regulating systems were studied during that time. Brachial artery diameter and blood flow were recorded using ultrasonography and Doppler. Endothelial function was assessed with flow-mediated dilation. Results were compared with the same investigations performed under reference conditions in ambient air. During water immersion, brachial artery diameter increased (3.7 ± 0.2 mm in ambient air vs. 4 ± 0.2 mm in water immersion; p immersion than in ambient air (10% vs. 15%; p = 0.01). Nevertheless, the difference disappeared when the percentage vasodilatation of the brachial artery was normalized to the shear stimulus. Smooth muscle-mediated dilation was similar in the 2 conditions. Spectral analysis of systolic blood pressure variability indicated a decrease in sympathetic vascular activity. Plasma levels of nitric oxide metabolites remained unchanged, whereas levels of natriuretic peptides were significantly elevated. An increase in brachial blood flow, a decrease in sympathetic activity, a warming of the skin, and an increase in natriuretic peptides might be involved in the increase in reference diameter observed during water immersion. Endothelial cell reactivity and smooth muscle function did not appear to be altered. PMID:24669983

Ayme, Karine; Gavarry, Olivier; Rossi, Pascal; Desruelle, Anne-Virginie; Regnard, Jacques; Boussuges, Alain

2014-04-01

 
 
 
 
201

Determination of water storage and permeability functions for oil sands tailings  

Energy Technology Data Exchange (ETDEWEB)

Mining projects in the Alberta oil sands produce tailings in a slurry form with high water content and that makes it difficult to characterize the unsaturated soil property functions. This paper discusses the determination of water storage and permeability functions for oil sands tailings. The objective is to describe a way to conduct a conventional soil-water characteristic curve test and use it with an independently measured shrinkage curve to determine the proper unsaturated soil property functions for numerically modeling the drying process. A lab procedure for measuring and interpreting shrinkage behavior of oil sands tailings is given with the results. To obtain a closed-form equation for the shrinkage curve, a regression curve-fitting analysis was used. The saturated coefficient of permeability is combined with the soil-water characteristic curve (SWCC) to compute hydraulic properties for the oil sands tailings. From the results it can be concluded that the volumetric water content is essential to computing the water storage characteristics of oil sands tailings.

Fredlund, Delwyn G.; Stone, Jeff; Stianson, Jason [Golder Associates Ltd. (Canada); Sedgwick, Andrea [Total EandP Canada (Canada)

2011-07-01

202

[The water-salt balance and renal function in space flights and in model experiments].  

Science.gov (United States)

Study of a condition of mineral and water-electrolyte metabolism, function of kidneys, and their hormonal regulation during model experiments (hypokinesia, bed rest, immersion etc.), and also in space flights and in readaptation period, has shown a major role of water-electrolyte homeostasis during general adaptation of humans and animals to new conditions of life and to conditions of weightlessness in particular. The change in regulation of volumes of fluid milieu in an initial period of weightlessness was shown to be the consequence of redistribution of blood and hemodynamics of the shifts resulting in change of production of volume-regulation hormones, formation of negative water balance, and redistribution of fluid in the organism among various fluid compartments. At later stages of flight or long-term hypokinesia, a change of water-electrolyte homeostasis occurs with a decrease in the kidneys excretion of sodium, and diuresis, but with an increased excretion of calcium and production of ADH and RAAS hormones. Following returning to earth gravitation, the majority of astronauts have adaptive reactions, compensating for the loss extracellular fluid and mineral substances and formation of "earth" water-electrolyte homeostasis. For estimation of water-electrolyte homeostasis and the functions of kidneys in astronauts, various functional loading tests have been developed. The developed system of preventive maintenance is successfully used for abolition of adverse changes at various stages of space flight and in readaptation period. PMID:12968528

Morukov, B V; Noskov, V B; Larina, I M; Natochin, Iu V

2003-03-01

203

Efficient classical density-functional theories of rigid-molecular fluids and a simplified free energy functional for liquid water  

Science.gov (United States)

Classical density-functional theory provides an efficient alternative to molecular dynamics simulations for understanding the equilibrium properties of inhomogeneous fluids. However, application of density-functional theory to multi-site molecular fluids has so far been limited by complications due to the implicit molecular geometry constraints on the site densities, whose resolution typically requires expensive Monte Carlo methods. Here, we present a general scheme of circumventing this so-called inversion problem: compressed representations of the orientation density. This approach allows us to combine the superior iterative convergence properties of multipole representations of the fluid configuration with the improved accuracy of site-density functionals. Armed with the above general framework, we construct a simplified free-energy functional for water which captures the radial distributions, cavitation energies, and the linear and nonlinear dielectric response of liquid water. The resulting approach will enable efficient and reliable first-principles studies of atomic-scale processes in contact with solution or other liquid environments.

Sundararaman, Ravishankar; Arias, T. A.

2014-03-01

204

Nonlinear programming using an expanded Lagrangian function : a water resources management case study  

International Nuclear Information System (INIS)

A special form of potential function called the Expanded Lagrangian Function was combined with the trust region algorithm to solve large-scale optimization problems regarding water resource management at large hydro-power plants. The proposed algorithm can be used to determine a feasible descent direction using a linear combination of an inexact Newton's direction and a steepest descent direction. A bi-dimensional trust region scheme is used to obtain fast convergence. The proposed method was successfully tested on real data from the Great Lakes water resources problem

205

Design of the FEM-FIR filter for displacement reconstruction using accelerations and displacements measured at different sampling rates  

Science.gov (United States)

This paper presents a displacement reconstruction scheme using acceleration measured at a high sampling rate and displacement measured at a considerably low sampling rate. The governing equation and the boundary conditions for the reconstruction are derived using the variational statement of an inverse problem to minimize the errors between measured and reconstructed responses. The transfer function of the governing equation is identically 1 over whole frequency domain, and the proposed scheme would not result in any reconstruction error. A finite impulse response filter (FIR filter) is formulated through the finite element discretization of the governing equation. The Hermitian shape function is adopted to interpolate the displacement in a finite element. The transfer functions of the FIR filter are derived, and their characteristics are thoroughly discussed. It is recommended that the displacement sampling rate should be higher than the Nyquist rate of the target frequency, which is the lowest physically meaningful frequency in measured acceleration. In case the displacement sampling rate is lower than the recommended rate, the use of a higher target accuracy, which is the predefined accuracy at the target frequency, is required. The reconstruction of velocity with the proposed scheme is also presented. The validity of the proposed scheme is demonstrated with a numerical simulation study and a field test on a simply-supported railway bridge.

Hong, Yun Hwa; Lee, Se Gun; Lee, Hae Sung

2013-07-01

206

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

207

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

208

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

209

On the analyticity of periodic gravity water waves with integrable vorticity function  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We prove that the streamlines and the profile of periodic gravity water waves traveling over a flat bed with wavespeed which exceeds the horizontal velocity of all fluid particles are real-analytic graphs if the vorticity function is merely integrable.

Escher, Joachim; Matioc, Bogdan-vasile

2013-01-01

210

A triple-function zwitterion for preparing water compatible diclofenac imprinted polymers.  

Science.gov (United States)

A novel zwitterion acting as both a functional monomer and a crosslinker with the protein-resistant ability concomitantly was synthesized for preparing water compatible diclofenac imprinted polymers. This new imprinted polymer showed high imprinting efficiency for template and strong anti-protein adsorption in aqueous medium. PMID:25387988

Shen, Feng; Zhang, Qingxi; Ren, Xueqin

2015-01-01

211

Density functional description of water condensation in proximity of nanoscale asperity  

CERN Document Server

We apply non-local density functional formalism to describe an equilibrium distribution of the water-like fluid in the asymmetric nanoscale junction presenting an atomic force microscope (AFM) tip dwelling above an arbitrary surface. The hydrogen bonding dominating in intermolecular attraction is modeled as a square well potential with two adjustable parameters (energy and length) characterizing well's depth and width. A water meniscus formed inside nanoscale junction is explicitly described for different humidity. Furthermore, we suggest a simple approach using polymolecular adsorption isotherms for the evaluation of an energetic parameter characterizing fluid (water) attraction to substrate. This model can be easily generalized for more complex geometries and effective intermolecular potentials. Our study establishes a framework for the density functional description of fluid with orientational anisotropy induced by non-uniform external electric field.

Paramonov, P B; Paramonov, Pavel B.; Lyuksyutov, Sergei F.

2005-01-01

212

Digestibility prediction of cooked plantain flour as a function of water content and temperature.  

Science.gov (United States)

The effect of temperature (T=55-120°C) and water content (X1=1.4-2.0kgkg(-1) dry basis) on the gelatinization and digestibility of plantain flour (Dominico Harton genotype) were investigated. The degree of plantain starch gelatinization (?) was measured by DSC and modelled as a function of T and X1, using the Weibull model. Rapidly digestible starch (RDS) and resistant starch (RS) fractions were evaluated for different ? values. An appropriate dimensionless variable was introduced to the analyzed and modelled RDS and RS as a function of ?. Starch gelatinization begins at a temperature above 59.6±0.5°C and ? is strongly dependent on T in non-limiting water conditions. The combined effects of T and X1 on the RDS and RS can be explained by ?. We demonstrate that various heat treatments and water contents lead to the same ?, with the same RDS and RS values. PMID:25542132

Giraldo Toro, A; Gibert, O; Ricci, J; Dufour, D; Mestres, C; Bohuon, P

2015-03-15

213

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

214

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

215

Displacement Current and Surface Flashover  

Energy Technology Data Exchange (ETDEWEB)

High-voltage vacuum insulator failure is generally due to surface flashover rather than insulator bulk breakdown. Vacuum surface flashover is widely believed to be initiated by a secondary electron emission avalanche along the vacuum-insulator interface. This process requires a physical mechanism to cause secondary electrons emitted from the insulator surface to return to that surface. Here, we show that when an insulator is subjected to a fast high-voltage pulse, the magnetic field due to displacement current through the insulator can provide this mechanism. This indicates the importance of the voltage pulse shape, especially the rise time, in the flashover initiation process.

harris, J R; Caporaso, G J; Blackfield, D; Chen, Y J

2007-07-17

216

Guest displacement in silicon clathrates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study both theoretically and experimentally the structure of the doped silicon clathrate II NaxSi34. We find that contrary to published works, the sodium atoms do not retain the T-d symmetry inside the Si-28 cages and move about 1 A away from the center of the cage. This displacement, in conjunction with that of a sodium atom in an adjacent Si-28 cage, leads to a ``dimerization'' of sodium atoms. As a consequence, Rietveld refinements of x-ray diffraction spectra and transport, vibrational...

Tournus, F.; Masenelli, B.; Melinon, P.; Conne?table, Damien; Blase, Xavier; Flank, A. M.; Lagarde, P.; Cros, C.; Pouchard, M.

2004-01-01

217

Guest displacement in silicon clathrates  

International Nuclear Information System (INIS)

We study both theoretically and experimentally the structure of the doped silicon clathrate II NaxSi34. We find that contrary to published works, the sodium atoms do not retain the Td symmetry inside the Si28 cages and move about 1 A away from the center of the cage. This displacement, in conjunction with that of a sodium atom in an adjacent Si28 cage, leads to a 'dimerization' of sodium atoms. As a consequence, Rietveld refinements of x-ray diffraction spectra and transport, vibrational, and electronic properties must be revisited

218

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

219

Assessment of density functional approximations for the hemibonded structure of water dimer radical cation  

CERN Document Server

Due to the severe self-interaction errors associated with some density functional approximations, conventional density functionals often fail to dissociate the hemibonded structure of water dimer radical cation (H2O)2+ into the correct fragments: H2O and H2O+. Consequently, the binding energy of the hemibonded structure (H2O)2+ is not well-defined. For a comprehensive comparison of different functionals for this system, we propose three criteria: (i) The binding energies, (ii) the relative energies between the conformers of the water dimer radical cation, and (iii) the dissociation curves predicted by different functionals. The long-range corrected (LC) double-hybrid functional, omegaB97X-2(LP) [J.-D. Chai and M. Head-Gordon, J. Chem. Phys., 2009, 131, 174105.], is shown to perform reasonably well based on these three criteria. Reasons that LC hybrid functionals generally work better than conventional density functionals for hemibonded systems are also explained in this work.

Pan, Piin-Ruey; Tsai, Ming-Kang; Kuo, Jer-Lai; Chai, Jeng-Da

2012-01-01

220

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

 
 
 
 
221

Chromophoric and dendritic phosphoramidites enable construction of functional dendrimers with exceptional brightness and water solubility.  

Science.gov (United States)

The fluorescence brightness of a molecular probe determines whether it can be effectively measured and its water solubility dictates if it can be applied in real-world biological systems. However, molecules brighter than the most efficient fluorescent dyes or particles brighter than quantum dots are hard to come by, especially when they must also be soluble in water. In this report, chromophoric phosphoramidites are used in a solid-state synthesis to construct functional dendrimers. When highly twisted chromophores are chosen and the proper spacers and dendrons are introduced, the resultant dendrimers emit exceptionally bright fluorescence. Chromophores, spacers, and dendrons are stitched together by efficient phosphoramidite reagents, which afford high-yield water-soluble phosphodiester linkages after deprotection. The resulting water-soluble dendrimers are exceptionally bright. PMID:25111357

Shaller, Andrew D; Wan, Wei; Zhao, Baoming; Li, Alexander D Q

2014-09-15

222

Comparison of Pattern Recognition, Artificial Neural Network and Pedotransfer Functions for Estimation of Soil Water Parameters  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the comparison of three different approaches to estimate soil water content at defined values of soil water potential based on selected parameters of soil solid phase. Forty different sampling locations in northeast of Iran were selected and undisturbed samples were taken to measure the water content at field capacity (FC, -33 kPa, and permanent wilting point (PWP, -1500 kPa. At each location solid particle of each sample including the percentage of sand, silt and clay were measured. Organic carbon percentage and soil texture were also determined for each soil sample at each location. Three different techniques including pattern recognition approach (k nearest neighbour, k-NN, Artificial Neural Network (ANN and pedotransfer functions (PTF were used to predict the soil water at each sampling location. Mean square deviation (MSD and its components, index of agreement (d, root mean square difference (RMSD and normalized RMSD (RMSDr were used to evaluate the performance of all the three approaches. Our results showed that k-NN and PTF performed better than ANN in prediction of water content at both FC and PWP matric potential. Various statistics criteria for simulation performance also indicated that between kNN and PTF, the former, predicted water content at PWP more accurate than PTF, however both approach showed a similar accuracy to predict water content at FC.

Nasrin GORBANZADEH

2010-09-01

223

Interfacial effects on the band edges of functionalized si surfaces in liquid water.  

Science.gov (United States)

By combining ab initio molecular dynamics simulations and many-body perturbation theory calculations of electronic energy levels, we determined the band edge positions of functionalized Si(111) surfaces in the presence of liquid water, with respect to vacuum and to water redox potentials. We considered surface terminations commonly used for Si photoelectrodes in water splitting experiments. We found that, when exposed to water, the semiconductor band edges were shifted by approximately 0.5 eV in the case of hydrophobic surfaces, irrespective of the termination. The effect of the liquid on band edge positions of hydrophilic surfaces was much more significant and determined by a complex combination of structural and electronic effects. These include structural rearrangements of the semiconductor surfaces in the presence of water, changes in the orientation of interfacial water molecules with respect to the bulk liquid, and charge transfer at the interfaces, between the solid and the liquid. Our results showed that the use of many-body perturbation theory is key to obtain results in agreement with experiments; they also showed that the use of simple computational schemes that neglect the detailed microscopic structure of the solid-liquid interface may lead to substantial errors in predicting the alignment between the solid band edges and water redox potentials. PMID:25402590

Pham, Tuan Anh; Lee, Donghwa; Schwegler, Eric; Galli, Giulia

2014-12-10

224

Current Density and Plasma Displacement Near Perturbed Rational Surface  

Energy Technology Data Exchange (ETDEWEB)

The current density in the vicinity of a rational surface of a force-free magnetic field subjected to an ideal perturbation is shown to be the sum of both a smooth and a delta-function distribution, which give comparable currents. The maximum perturbation to the smooth current density is comparable to a typical equilibrium current density and the width of the layer in which the current flows is shown to be proportional to the perturbation amplitude. In the standard linearized theory, the plasma displacement has an unphysical jump across the rational surface, but the full theory gives a continuous displacement.

A.H. Boozer and N. Pomphrey

2010-10-10

225

SPS data on tunnel displacements and the ATL law  

International Nuclear Information System (INIS)

In this article we analyze data from long-term measurements of quadrupole displacements in the Super Proton Synchrotron ring at CERN. The variance of displacement can be approximated by ATL law with coefficient A = (0.1--0.4) * 10-4 ?m2/s/m, with T the time interval between measurements and L the distance between two points of the tunnel. The shape of the distribution function is found to be close to Gaussian. The results of the analysis are compared with other data on slow ground motion

226

Simulation of threshold displacements in NiAl  

International Nuclear Information System (INIS)

Modified many-body interatomic potentials for modeling high-energy atomic collision in NiAl are constructed and described. The displacement threshold energy as a function of the primary recoil direction for Ni atoms and Al atoms in NiAl has been investigated by molecular dynamics simulations using the modified potentials. The defect structure induced by recoil events has been presented. The results show that the lowest threshold displacement energy, Ed, is near the orientation and the mean value of Ed for an Al atom is higher than a Ni. A crowdion in the compact crystalline directions, , incorporating an extra Ni atom is the stable interstitial configuration

227

Simulation of displacement cascades in Ni-Al ordered alloys  

Science.gov (United States)

Molecular dynamics was used to investigate defect production induced by displacement cascades in ordered intermetallic alloys NiAl and Ni3Al. The composite potentials obtained from the embedded atom potentials (EAM) and the universal function of Biersack and Ziegler were used. The number of point defects and their final structure produced by displacement cascades were investigated and compared with the standard NRT prediction. Crystalline structure, atomic mixing and chemical disordering were also studied during the evolution of the cascades, by measuring their characteristic parameters in the cells of the subdivided crystal.

Doan, N. V.; Vascon, R.

228

Analysis of a plastic optical fiber-based displacement sensor.  

Science.gov (United States)

An easy-to-manufacture setup for a displacement sensor based on plastic optical fiber (POF) is analyzed, showing computational and experimental results. If the displacement is the consequence of force or pressure applied to the device, this can be used as a force or pressure transducer. Its principle of operation consists of bending a POF section around a flexible cylinder and measuring light attenuation when the whole set is subjected to side pressure. Attenuations are obtained computationally as a function of side deformation for different design parameters. Experimental results with an actually built prototype are also provided. PMID:17805359

Jiménez, Felipe; Arrue, Jon; Aldabaldetreku, Gotzon; Durana, Gaizka; Zubia, Joseba; Ziemann, Olaf; Bunge, Christian-Alexander

2007-09-01

229

Steering of H{sup -} ion beamlet by aperture displacement  

Energy Technology Data Exchange (ETDEWEB)

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{sup -} 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 {approx}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{sup -} 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)

Inoue, Takashi; Miyamoto, Kenji; Okumura, Yoshikazu [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Suzuki, Yasuo [Toshiba Corp., Kawasaki, Kanagawa (Japan)

2000-09-01

230

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

231

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 horizontal displacement and vertical displacement vary apparently and dynamically so both may require monitoring. In this study, a II-type deep displacement sensor is designed by revising our I-type sensor to simultaneously monitor the deep horizontal displacement and vertical displacement variations at different depths within a sliding mass. Meanwhile, a new theoretical modeling called the numerical integration-based equivalent loop approach (NIELA has been proposed to quantitatively depict II-type sensors’ mutual inductance properties with respect to predicted horizontal displacements and vertical displacements. After detailed examinations and comparative studies between measured mutual inductance voltage, NIELA-based mutual inductance and EELA-based mutual inductance, NIELA has verified to be an effective and quite accurate analytic model for characterization of II-type sensors. The NIELA model is widely applicable for II-type sensors’ monitoring on all kinds of landslides and other related geohazards with satisfactory estimation accuracy and calculation efficiency.

Xiong Li

2011-12-01

232

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

233

Long-time mean-square displacements in proteins  

Science.gov (United States)

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, Iinc(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 Iinc(Q,t). Specifically, the is defined in the usual way in terms of the Debye-Waller factor as I(Q,t=?)=exp(-Q2/3). 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 and to 10 ns is found to be the same. The intrinsic is approximately twice the value of the MSD that is reached in simulations after times of 1 ns which correspond to those observed using neutron instruments that have an energy resolution width of 1 ?eV.

Vural, Derya; Hong, Liang; Smith, Jeremy C.; Glyde, Henry R.

2013-11-01

234

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

Science.gov (United States)

The scaled versions of the newly introduced [S. S. Xantheas and J. C. Werhahn, J. Chem. Phys. 141, 064117 (2014)] generalized forms of some popular potential energy functions (PEFs) describing intermolecular interactions - Mie, Lennard-Jones, Morse, and Buckingham exponential-6 - have been used to fit the ab initio relaxed approach paths and fixed approach paths for the halide-water, X-(H2O), X = F, Cl, Br, I, and alkali metal-water, M+(H2O), M = Li, Na, K, Rb, Cs, interactions. The generalized forms of those PEFs have an additional parameter with respect to the original forms and produce fits to the ab initio data that are between one and two orders of magnitude better in the ?2 than the original PEFs. They were found to describe both the long-range, minimum and repulsive wall of the respective potential energy surfaces quite accurately. Overall the 4-parameter extended Morse (eM) and generalized Buckingham exponential-6 (gBe-6) potentials were found to best fit the ab initio data for these two classes of ion-water interactions. The fitted values of the parameter of the (eM) and (gBe-6) PEFs that control the repulsive wall of the potential correlate remarkably well with the ionic radii of the halide and alkali metal ions.

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

2014-08-01

235

An adaptive displacement estimation algorithm for improved reconstruction of thermal strain.  

Science.gov (United States)

Thermal strain imaging (TSI) can be used to differentiate between lipid and water-based tissues in atherosclerotic arteries. However, detecting small lipid pools in vivo requires accurate and robust displacement estimation over a wide range of displacement magnitudes. Phase-shift estimators such as Loupas' estimator and time-shift estimators such as normalized cross-correlation (NXcorr) are commonly used to track tissue displacements. However, Loupas' estimator is limited by phase-wrapping and NXcorr performs poorly when the SNR is low. In this paper, we present an adaptive displacement estimation algorithm that combines both Loupas' estimator and NXcorr. We evaluated this algorithm using computer simulations and an ex vivo human tissue sample. Using 1-D simulation studies, we showed that when the displacement magnitude induced by thermal strain was >?/8 and the electronic system SNR was >25.5 dB, the NXcorr displacement estimate was less biased than the estimate found using Loupas' estimator. On the other hand, when the displacement magnitude was ??/4 and the electronic system SNR was ?25.5 dB, Loupas' estimator had less variance than NXcorr. We used these findings to design an adaptive displacement estimation algorithm. Computer simulations of TSI showed that the adaptive displacement estimator was less biased than either Loupas' estimator or NXcorr. Strain reconstructed from the adaptive displacement estimates improved the strain SNR by 43.7 to 350% and the spatial accuracy by 1.2 to 23.0% (P < 0.001). An ex vivo human tissue study provided results that were comparable to computer simulations. The results of this study showed that a novel displacement estimation algorithm, which combines two different displacement estimators, yielded improved displacement estimation and resulted in improved strain reconstruction. PMID:25585398

Ding, Xuan; Dutta, Debaditya; Mahmoud, Ahmed; Tillman, Bryan; Leers, Steven; Kim, Kang

2015-01-01

236

THz absorption spectra and stability of Fe water complexes calculated by density functional theory  

Science.gov (United States)

Monitoring of water contaminants implies a need for determining their dielectric response properties with re- spect to electromagnetic wave excitation at various frequencies. Iron is a naturally occurring water contaminant resulting from decaying vegetation, which is at much higher concentrations than any other metal contaminant. The present study uses density functional theory (DFT) for the calculation of ground state resonance struc- ture and molecular stability analysis for Fe water complexes. The calculations presented are for excitation by electromagnetic waves at frequencies within the THz range. Dielectric response functions calculated by DFT can be used for the analysis of water contaminants. These functions provide quantitative initial estimates of spectral response features for subsequent adjustment with respect to additional information such as laboratory measurements and other types of theory based calculations. In addition, with respect to qualitative analysis, DFT calculated absorption spectra provide for molecular level interpretation of response structure. The DFT software GAUSSIAN was used for the calculations of ground state resonance structure presented here.

Huang, L.; Lambrakos, S. G.; Shabaev, A.; Massa, L.; Yapijakis, C.

2013-05-01

237

Work function changes of cobalt films at 77 K upon water adsorption  

Science.gov (United States)

From the model of immobile adsorption an equation is deduced to interpret the dependence of work function ? on coverage ?. The equation is proved to be useful to get a better insight into the interaction mechanism between water molecules and Co films at 77 K. The films were obtained in UHV by condensation of the vapour at 77 K. They were prepared with different morphologies, achieved by sintering at temperatures up to 478 K and characterized by the work function ? and the electrical resistance R. Besides monitoring the changes in ? and R, the processes were followed by thermal desorption mass spectroscopy (TDMS). In all cases, water adsorption at 77 K up to a monolayer caused a decrease in ? which was greater the higher the initial ?. TDMS results on clean films sintered at 77 K showed only the desorption of H 2, while those sintered at 478 K mainly water. Successive cycles of H 2O adsorption at 77 K followed by thermodesorption by heating up to 478 K, completely passivated the surface for water decomposition. The parameters obtained from fitting the model to experimental data are physically meaningful only for passivated surfaces. This points to a decomposition of water at 77 K, the extent of which is greater the lower the initial ? of the Co-surface.

Heras, J. M.; Albano, E. V.

238

Density-modified displacement for dense nonaqueous-phase liquid source-zone remediation: density conversion using a partitioning alcohol.  

Science.gov (United States)

Entrapped and pooled dense nonaqueous-phase liquids (DNAPLs) often persist in aquifers and serve as a long-term source of groundwater contamination. To address the problematic nature of DNAPL remediation, a surfactant-enhanced aquifer remediation (SEAR) technology, density-modified displacement (DMD), has been developed which significantly reduces the risk of downward migration of displaced DNAPLs. The DMD method is designed to accomplish DNAPL density conversion through the introduction of a partitioning alcohol, n-butanol (BuOH), in a predisplacement flood using conventional horizontal flushing schemes. Subsequent displacement and recovery of the resulting LNAPL is achieved by flushing with a low-interfacial tension surfactant solution. The objective of this study was to investigate density conversion of two representative DNAPLs, chlorobenzene (CB) and trichloroethene (TCE). A series of batch experiments was performed to assess changes in NAPL composition, density, and phase behavior as a function of BuOH mole fraction. Experimental results were used to develop contaminant/BuOH/water ternary phase diagrams and to elucidate regions of contrasting NAPL density. UNIQUAC calculations are presented to support measured compositional and phase behavior data. Density conversion of CB and TCE, relative to water, occurred at NAPL BuOH mole fractions of 0.38 and 0.50, respectively. Significant incorporation of water into the organic phase was observed at relatively high BuOH mole fractions and was shown to limit changes in NAPL composition and density. Interfacial tensions between CB-NAPL and TCE-NAPL and a 6% (by wt) BuOH aqueous solution were found to decrease with increasing NAPL BuOH mole fraction, although in both cases the measured values remained above 2.5 dyn/cm. Total trapping number calculations suggest that, in most aquifer formations, density conversion can be achieved without premature NAPL displacement using a 6% (by wt) BuOH aqueous solution. PMID:12026997

Ramsburg, C Andrew; Pennell, Kurt D

2002-05-01

239

Multi-functional manipulations of microobjects based on electrolysis of water  

Science.gov (United States)

The micromanipulation technology still faces some challenges. Direct rotary step-driving of a microobject has not been realized by physical means. The implementation of 3-D attitude adjustment of a microobject usually involves a complicated driving and controlling system. The capability and controllability of releasing sticky microobjects from a probe is still limited. In this paper, we demonstrate a strategy to use hydrogen bubbles generated by electrolysis of water to manipulate microobjects in water on a substrate surface. Manipulation functions implemented by this strategy include direct rotary step-driving and attitude adjustment of a single microparticle, and controlled release of a single sticky microparticle.

Li, Ning; Hu, Junhui

2013-09-01

240

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.

 
 
 
 
241

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

Energy Technology Data Exchange (ETDEWEB)

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-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.

Okoli, Chuka [Royal Institute of Technology (KTH), Environmental Microbiology (Sweden); Boutonnet, Magali; Jaeras, Sven [Royal Institute of Technology (KTH), Chemical Technology (Sweden); Rajarao-Kuttuva, Gunaratna, E-mail: gkr@kth.se [Royal Institute of Technology (KTH), Environmental Microbiology (Sweden)

2012-10-15

242

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

243

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

244

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

245

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 ...

246

Analysis of irreversible displacements of Daniel-Johnson dam  

Energy Technology Data Exchange (ETDEWEB)

Irreversible displacements in dams are associated with alkali-aggregate reaction, creep, and other damaging effects that compromise the safety of dams. An identification of the nature of irreversible displacements is needed to predict the future behaviour of dams as well as to select appropriate remedial measures. This paper provided details of a principal component analysis (PCA) used to investigate swelling and small irreversible displacements observed at the Daniel-Johnson dam in Quebec. PCA is a multivariate statistical method that performs the analysis of correlations or covariances between several random variables simultaneously. Three datasets were used: (1) reservoir water level; (2) air temperature; and (3) pendulum displacements. Standard linear regression analyses (HST) were performed for each variable in order to eliminate outliers and replace missing values. The multivariate dataset was then used to perform PCA on the entire dataset as well as on subsets from the original data. Displacement data from pendulums were used in the multivariate statistical analysis in which each component was treated as a separate variable. The comparison of irreversible displacements of the dam from HST analysis and principal component analysis (PCA) indicated that results were consistent with the data. The PCA analysis identified dominant patterns of behaviour and detected 2 distinct components of irreversible deformations arising from creep and swelling of concrete. Results of the study showed that the PCA analysis led to a better understanding of the overall behaviour of the dam and of individual arches and buttresses. It was concluded that the PCA analysis method will help to improve dam safety in addition to more accurately predicting the future behaviour of dams. 6 refs., 2 tabs., 9 figs.

Chouinard, L.; Zhao, W. [McGill Univ., Montreal, PQ (Canada); Lariviere, R. [Hydro-Quebec, Montreal, PQ (Canada); Cote, P. [Hydro-Quebec Production, Baie-Comeau, PQ (Canada)

2006-07-01

247

Gold-catalyzed tandem cycloisomerization/functionalization of in situ generated ?-oxo gold carbenes in water.  

Science.gov (United States)

A gold-catalyzed tandem cycloisomerization/functionalization of in situ generated ?-oxo gold carbenes in water has been developed, which provides ready access to highly functionalized indole derivatives from o-alkynyl anilines and ynamides. Importantly, gold serves dual catalytic roles to mediate both the cycloisomerization of o-alkynyl anilines and the intermolecular oxidation of ynamides at the same time, thus providing a new type of concurrent tandem catalysis. The use of readily available starting materials, a simple procedure, and mild reaction conditions are other notable features of this method. PMID:25229883

Shen, Cang-Hai; Li, Long; Zhang, Wei; Liu, Shuang; Shu, Chao; Xie, Yun-Er; Yu, Yong-Fei; Ye, Long-Wu

2014-10-01

248

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

249

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)

250

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)

251

Estimating hysteresis in the soil water retention function from cone permeameter experiments  

Science.gov (United States)

Data obtained from modified cone penetrometer experiments were used to estimate the hysteretic soil hydraulic properties with a parameter estimation technique which combined a numerical solution of the Richards equation with Marquardt-Levenberg optimization. The modified cone penetrometer was designed to inject water into a soil through a cylindrical screen, measure the infiltration rate with time, and track the movement of the wetting front using two tensiometer rings positioned above the screen. After reaching relatively stable tensiometer readings during the experiments, the source of water was cut off and pressure head readings measured while water in the soil profile redistributed. Cumulative inflow and pressure head readings for two experiments with different supply pressures were analyzed to obtain estimates of the soil water retention and hydraulic conductivity functions. Analysis of flow responses obtained during the infiltration period, and of those obtained during the combined infiltration and redistribution phases, demonstrated the importance of hysteresis of the soil hydraulic functions. We found that the redistribution phase could not be described accurately when hysteresis was neglected. Hysteresis in the soil hydraulic functions was modeled using a relatively simple empirical model in which wetting scanning curves are scaled from the main wetting curve and drying scanning curves are scaled from the main drying curve. This model was deemed adequate for our examples. Optimization results for various combinations of unknown soil hydraulic parameters were compared to results of standard laboratory and in situ methods. Estimates of the saturated hydraulic conductivity were well within the range of in situ measurements. The estimated main hysteretic loops of the soil water retention curve were for the most part situated between the wetting and drying curves obtained with standard methods.

Šim?nek, Ji?í; Kodešová, Radka; Gribb, Molly M.; van Genuchten, Martinus T.

252

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

253

Functionality of grass software for topographic analysis for the methodology of tracking water flow  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the thesis I thoroughly examined the free and open-source software package GRASS (Geographic Resources Analysis Support System), which is considered as being one of the most comprehensive and multi-purpose »Desktop« GIS (Geographic Information System). I focused on the review of GRASS software modules for carrying out topographical analyses, which are based on the methodology of tracking or routing of water flow, and on the display of their functionality in a real case. The thesis i...

Poljans?ek, Sas?o

2012-01-01

254

Mountain border area of eastern Serbia in the function of the spring zones of surface water  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Border mountain area of eastern Serbia has a distinct potential and importance in the function of surface water sources, which are characterized by range of geographical and environmental characteristics and similarities determined by mountainous character of the territory. For the purposes of this paper, border area of Serbia towards Bulgaria is provisionally determined by iso-border of 25 km. On the defined area of eastern Serbia there are 11 individual territories allocated in the fu...

Milin?i? Miroljub; Mihajlovi? Bojana; Šabi? Dejan; ?ur?i? Nina

2012-01-01

255

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

256

Displacement speeds in turbulent premixed flame simulations  

Energy Technology Data Exchange (ETDEWEB)

The theory of turbulent premixed flames is based on acharacterization of the flame as a discontinuous surface propagatingthrough the fluid. The displacement speed, defined as the local speed ofthe flame front normal to itself, relative to the unburned fluid,provides one characterization of the burning velocity. In this paper, weintroduce a geometric approach to computing displacement speed anddiscuss the efficacy of the displacement speed for characterizing aturbulent flame.

Day, Marcus S.; Shepherd, Ian G.; Bell, J.; Grcar, Joseph F.; Lijewski, Michael J.

2007-07-01

257

Displacement energy of unit cotangent bundles  

CERN Document Server

For given Riemannian manifold, we study the displacement energy of its unit cotangent bundle in its cotangent bundle. This displacement energy is obviously equal to infinity when the Riemannian manifold is closed. On the otherhand, our main result gives a nice upper bound of this displacement energy when the Riemannian manifold is noncompact. As an application, we prove the existence of a "short" periodic billiard trajectory on any compact Riemannian manifold with boundary.

Irie, Kei

2011-01-01

258

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

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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

259

Interaction of TiO2(-) with water: photoelectron spectroscopy and density functional calculations.  

Science.gov (United States)

The interactions of titania with water molecules were studied via photoelectron spectroscopy and density functional calculations of TiO(OH)2(-) and Ti(OH)4(H2O)n(-) (n = 0-5) clusters which are corresponding to the TiO2(H2O)(-) and TiO2(H2O)n+2(-) (n = 0-5) systems, respectively. Experimental observation and theoretical calculations confirmed that TiO(OH)2(-) was produced when TiO2(-) interacts with one water molecule, and Ti(OH)4(H2O)n(-) (n = 0-5) were produced successively when TiO2(-) interacts with two or more water molecules. The structures of Ti(OH)4(H2O)n(-) with n = 4, 5 are slightly different from those of n = 1-3. The structures of Ti(OH)4(H2O)1-3(-) can be viewed as the water molecules interacting with the Ti(OH)4(-) core through hydrogen bonds; however, in Ti(OH)4(H2O)4,5(-), one of the water molecules interacts directly with the Ti atom via its oxygen atom instead of a hydrogen bond and distorted the Ti(OH)4(-) core. PMID:24320270

Li, Ren-Zhong; Xu, Hong-Guang; Cao, Guo-Jin; Xu, Xi-Ling; Zheng, Wei-Jun

2013-11-14

260

Comparison of Water Production Functions for Winter Wheat in Mashhad Region  

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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

 
 
 
 
261

Interaction of TiO2? with water: Photoelectron spectroscopy and density functional calculations  

International Nuclear Information System (INIS)

The interactions of titania with water molecules were studied via photoelectron spectroscopy and density functional calculations of TiO(OH)2? and Ti(OH)4(H2O)n? (n = 0–5) clusters which are corresponding to the TiO2(H2O)? and TiO2(H2O)n+2? (n = 0–5) systems, respectively. Experimental observation and theoretical calculations confirmed that TiO(OH)2? was produced when TiO2? interacts with one water molecule, and Ti(OH)4(H2O)n? (n = 0–5) were produced successively when TiO2? interacts with two or more water molecules. The structures of Ti(OH)4(H2O)n? with n = 4, 5 are slightly different from those of n = 1–3. The structures of Ti(OH)4(H2O)1-3? can be viewed as the water molecules interacting with the Ti(OH)4? core through hydrogen bonds; however, in Ti(OH)4(H2O)4,5?, one of the water molecules interacts directly with the Ti atom via its oxygen atom instead of a hydrogen bond and distorted the Ti(OH)4? core

262

Displacement of Monolithic Rubble-Mound Breakwater Crown-Walls  

DEFF Research Database (Denmark)

This paper evaluates the validity of a simple one-dimensional dynamic analysis as well as a Finite-Element model to determine the sliding of a rubble-mound breakwater crown-wall. The evaluation is based on a case example with real wave load time-series and displacements measured from two-dimensional physical model tests. The outcome is a more reliable evaluation of the applicability of simple dynamic calculations for the estimation of displacement of rubble-mound superstructures. The case example clearly demonstrates that a simplified one-dimensional sliding model provides a safe estimate of the accumulated sliding distance of crown-wall superstructures, which is in contrast to findings from previous similar studies on caisson breakwaters. The calculated sliding distance is approximately three times larger than the measured one when using the original one-dimensional model suggested in previous studies on caisson breakwaters, but correction terms are suggested in the present paper to obtain almost equal measured and estimated displacements. This is of great practical importance since many existing rubble-mound crown-walls are subjected to increasing wave loads due to rising sea water level from climate changes. Reliable and safe estimates are needed to determine whether displacements of crown wall superstructures during extreme situations would be acceptable or whether they lead to total failure of the structures.

NØrgaard, JØrgen Harck; Andersen, Lars Vabbersgaard

2012-01-01

263

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)

264

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

265

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

266

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

267

Benefit of warm water immersion on biventricular function in patients with chronic heart failure  

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Full Text Available Abstract Background Regular physical activity and exercise are well-known cardiovascular protective factors. Many elderly patients with heart failure find it difficult to exercise on land, and hydrotherapy (training in warm water could be a more appropriate form of exercise for such patients. However, concerns have been raised about its safety. The aim of this study was to investigate, with echocardiography and Doppler, the acute effect of warm water immersion (WWI and effect of 8 weeks of hydrotherapy on biventricular function, volumes and systemic vascular resistance. A secondary aim was to observe the effect of hydrotherapy on brain natriuretic peptide (BNP. Methods Eighteen patients [age 69 ± 8 years, left ventricular ejection fraction 31 ± 9%, peakVO2 14.6 ± 4.5 mL/kg/min] were examined with echocardiography on land and in warm water (34°C. Twelve of these patients completed 8 weeks of control period followed by 8 weeks of hydrotherapy twice weekly. Results During acute WWI, cardiac output increased from 3.1 ± 0.8 to 4.2 ± 0.9 L/min, LV tissue velocity time integral from 1.2 ± 0.4 to 1.7 ± 0.5 cm and right ventricular tissue velocity time integral from 1.6 ± 0.6 to 2.5 ± 0.8 cm (land vs WWI, p There was no change in the cardiovascular response or BNP after 8 weeks of hydrotherapy. Conclusion Hydrotherapy was well tolerated by all patients. The main observed cardiac effect during acute WWI was a reduction in heart rate, which, together with a decrease in afterload, resulted in increases in systolic and diastolic biventricular function. Although 8 weeks of hydrotherapy did not improve cardiac function, our data support the concept that exercise in warm water is an acceptable regime for patients with heart failure.

Kardassis Dimitris

2009-07-01

268

Water  

Science.gov (United States)

... drinking water by consuming only bottled water or water from a filtration system that has been certified by an independent ... 15 ppb, CDC recommends using bottled water or water from a filtration system that has been certified by an independent ...

269

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

Directory of Open Access Journals (Sweden)

Full Text Available Immersion freezing of water and aqueous (NH42SO4 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.

Y. J. Rigg

2013-02-01

270

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

271

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

272

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

273

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)

274

Fractal dimensionality of cascades of atomic displacements  

International Nuclear Information System (INIS)

The cascades of opening displacements, formed during irradiation of solids are the most typical process of dissipation of the energy of incident particles and the generation of radiation defects. The aim of the present work is the examination of the energy dependence of the fractal dimensionality of the cascades of atomic displacements in the solid

275

Intramolecular cyclization of aspartic acid residues assisted by three water molecules: a density functional theory study  

Science.gov (United States)

Aspartic acid (Asp) residues in peptides and proteins (l-Asp) are known to undergo spontaneous nonenzymatic reactions to form l-?-Asp, d-Asp, and d-?-Asp residues. The formation of these abnormal Asp residues in proteins may affect their three-dimensional structures and hence their properties and functions. Indeed, the reactions have been thought to contribute to aging and pathologies. Most of the above reactions of the l-Asp residues proceed via a cyclic succinimide intermediate. In this paper, a novel three-water-assisted mechanism is proposed for cyclization of an Asp residue (forming a gem-diol precursor of the succinimide) by the B3LYP/6-31 + G(d,p) density functional theory calculations carried out for an Asp-containing model compound (Ace-Asp-Nme, where Ace = acetyl and Nme = NHCH3). The three water molecules act as catalysts by mediating ‘long-range’ proton transfers. In the proposed mechanism, the amide group on the C-terminal side of the Asp residue is first converted to the tautomeric iminol form (iminolization). Then, reorientation of a water molecule and a conformational change occur successively, followed by the nucleophilic attack of the iminol nitrogen on the carboxyl carbon of the Asp side chain to form the gem-diol species. A satisfactory agreement was obtained between the calculated and experimental energetics.

Takahashi, Ohgi; Kirikoshi, Ryota

2014-01-01

276

Conductive methyl blue-functionalized reduced graphene oxide with excellent stability and solubility in water  

International Nuclear Information System (INIS)

Graphical abstract: MB-rGO was synthesized by making use of ? stacking and water-solubility of MB to assist the hydrazine mediated reduction of graphene oxide (GO) in aqueous solution. The resulting MB-rGO shows excellent solubility and stability in aqueous solution, and the electrical conductivity of MB-rGO is almost two orders of magnitude larger than that of GO. Highlights: ? Methyl blue (MB) stacks onto the plane of reduced graphene oxide (rGO) by strong ?–? interactions. ? Sulfo groups of MB prevent rGO from aggregating by electrostatic and steric repulsions. ? MB-functionalized rGO (MB-rGO) shows excellent solubility and stability in aqueous solution. ? Electrical conductivity of MB-rGO is almost two orders of magnitude larger than that of GO. -- Abstract: ? stacking and water-solubility of methyl blue (MB) are expected to facilitate the hydrazine mediated reduction of graphene oxide (GO) in aqueous environment. Our newly obtained MB-functionalized reduced graphene oxide (MB-rGO) exhibited excellent solubility and stability in water. The results showed that the MB molecules stacked non-covalently onto the basal plane of rGO while the sulfo groups of MB prevented the rGO from aggregation. In addition, the better electrical conductivity of MB-rGO than that of GO was analyzed. This novel conductive MB-rGO should have promising applications in diverse nanotechnological areas, such as electronic and optoelectronic devices, photovoltaics, sensors, and microfabrication.

277

Source water partitioning as a means of characterizing hydrologic function in mangroves  

Science.gov (United States)

Mangrove ecosystems rely on seawater, rain-derived flow, and groundwater for hydrologic sustenance, flushing, and inflow of nutrients and sediments. The relative contribution of these source waters and their variability through time and space can provide key information concerning the hydrologic function of ecosystems. We used hydrologic tracers to partition source waters and trace their movements in the Enipoas stream, a river-dominated mangrove ecosystem on the island of Pohnpei, Federated States of Micronesia (FSM) and in the Yela watershed, an interior mangrove ecosystem on the island of Kosrae, FSM. The Enipoas site was characterized as a salt wedge estuary whose source water contributions alternated between predominantly seawater and rain-derived flow, depending on the tide. The source waters in the interior Yela site were also predominantly seawater and rain-derived flow, however the relative contribution of each was much more stable. The mean groundwater contribution was 5% (SD = 5.5) for the Enipoas site and 20% (SD = 11.0) for the Yela site. Although a small contributor to flow, groundwater was a steady source of freshwater for both systems. Hydrologic linkages between mangroves and adjacent ecosystems were demonstrated by the temporal and spatial distribution of source waters. The 0.8 km Enipoas estuary, with its highly dynamic bi-directional flows, transported source waters along a hydrologic continuum comprised of coral reef, mangroves, and palm forest. In the interior mangroves of the Yela watershed, the presence of rain-derived flow and groundwater demonstrated a hydraulic connection between the mangroves and an upstream freshwater swamp. Interior mangroves with such linkages avoid stresses such as desiccation and heightened salinity, and thus are more productive than those with little or no freshwater flows.

Drexler, J.Z.; De Carlo, E. W.

2002-01-01

278

Adsorption and capillary condensation in porous media as a function of the chemical potential of water in carbon dioxide  

Science.gov (United States)

chemical potential of water may play an important role in adsorption and capillary condensation of water under multiphase conditions at geologic CO2 storage sites. Injection of large volumes of anhydrous CO2 will result in changing values of the chemical potential of water in the supercritical CO2 phase. We hypothesize that the chemical potential will at first reflect the low concentration of dissolved water in the dry CO2. As formation water dissolves into and is transported by the CO2 phase, the chemical potential of water will increase. We present a pore-scale model of the CO2-water interface or menisci configuration based on the augmented Young-Laplace equation, which combines adsorption on flat surfaces and capillary condensation in wedge-shaped pores as a function of chemical potential of water. The results suggest that, at a given chemical potential for triangular and square pores, liquid water saturation will be less in the CO2-water system under potential CO2 sequestration conditions relative to the air-water vadose zone system. The difference derives from lower surface tension of the CO2-water system and thinner liquid water films, important at pore sizes reservoir rocks, but still may be important in finer grained, clayey caprocks, where very small pores may retain water and draw water back into the system via adsorption and capillary condensation, if dry-out and then rewetting were to occur.

Heath, Jason E.; Bryan, Charles R.; Matteo, Edward N.; Dewers, Thomas A.; Wang, Yifeng; Sallaberry, Cédric J.

2014-03-01

279

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

280

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

 
 
 
 
281

Optimal Model on Canal Water Distribution Based on Dynamic Penalty Function and Genetic Algorithm  

Science.gov (United States)

The present optimal water delivery scheduling models are based on the assumed equal design discharges of lateral canals, which are not in accordance with practical water delivery scheduling demand in most irrigation systems. In order to solve this problem, a model of lateral canals with unequal discharges and a solution method were proposed; At present, traditional fixed penalty factor have some problem, such as it is difficulty to use unified dimension and to get a higher searching precision, besides, it prematurely converge to local optimal solution. Therefore, the thought of simulated annealing was referred to design a dynamic penalty function. In the progress of genetic operation, the SGA (Simple Genetic Algorithm) adopted adaptive crossover mutation method, and compared distinct solutions of model which based on the method in this paper, Adaptive genetic algorithm (AGA) and traditional methods used in irrigation district widely respectively. Comparing with water delivery plan compiled using traditional methods, the results illustrate that using this method can get much more reasonable lateral canals water delivery time and homogeneous discharges of upper canal. AGA can adjust the genetic controlling parameters automatically on the basis of values of individual fitness and degree of population dispersion, and get a high precision solution. So it has a higher practical value in irrigation system management.

Zhao, Wenju; Ma, Xiaoyi; Kang, Yinhong; Ren, Hongyi; Su, Baofeng

282

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

283

Non-reflecting boundary flux function for finite volume shallow-water models  

Science.gov (United States)

An approach to implement non-reflecting boundary conditions in finite-volume based shallow-water models is presented. Shallow-water models are routinely applied to sections of rivers, estuaries, and coastal zones, introducing computational boundaries where no physical control is present, and necessitating a condition that supplies information to the model while it simultaneously allows disturbances from the interior to pass out unhampered. The approach presented here builds upon the finite-volume convention of constructing a Riemann problem at the interface between cells and then solving it with a flux function. Hence, non-reflecting boundary conditions are achieved using a non-reflecting flux function on cell faces aligned with open boundaries. Numerical tests show that the non-reflecting flux function performs extremely well when waves advance toward the boundary with a small incident angle (approximately less than 45° from the boundary normal direction), while very minor reflections are present when the incident angle is larger. The presence of minor reflections, when the incident angle is large, is consistent with non-reflecting conditions previously implemented in finite-difference based schemes.

Sanders, Brett F.

284

Evaluation of renal function by dynamic MR imaging. Effect of water load  

International Nuclear Information System (INIS)

The aim of this study was to investigate the usefulness of magnetic resonance (MR) imaging in the evaluation of renal function, with particular attention to the effects of water load. Ten healthy volunteers underwent dynamic MR imaging after an injection of gadolinium diethylenetriaminepenta-acetic acid (Gd-DTPA) as a contrast agent to evaluate renal function by the following four methods: the positive method [longitudinal relaxation time (T1) shortening is the dominant effect], the negative method [transverse relaxation time (T2) shortening is the dominant effect] and two intermediate methods by switching the Gd-DTPA concentrations used in the positive and negative methods. A prolonged cortical peak time and a reduced medullary peak level were observed by the positive method under a dehydrated condition, suggesting that these variables were slightly influenced by Gd-DTPA concentrated in the medulla. By the negative method, low signals due to T2* (T2* is the effective transverse relaxation time, typically shorter than T2) shortening appeared in the medulla under normal conditions, but these signals were unclear when the subject was under an overhydrated condition. These results indicate that water metabolism, in addition to imaging parameters and Gd-DTPA dose levels, should be considered when renal function is evaluated by dynamic MR imaging. Analysis of both the pattern of MR images and the time-signal intensity curves may be useful in the evaluation of renal functio useful in the evaluation of renal function. The results also indicate that the positive method is perferred when the patient is overhydrated as it allows the evaluation of the local renal kinetic function by recording changes in the regional contract agent levels. (author)

285

Accuracy enhancement of point triangulation probes for linear displacement measurement  

Science.gov (United States)

Point triangulation probes (PTBs) fall into a general category of noncontact height or displacement measurement devices. PTBs are widely used for their simple structure, high resolution, and long operating range. However, there are several factors that must be taken into account in order to obtain high accuracy and reliability; measurement errors from inclinations of an object surface, probe signal fluctuations generated by speckle effects, power variation of a light source, electronic noises, and so on. In this paper, we propose a novel signal processing algorithm, named as EASDF (expanded average square difference function), for a newly designed PTB which is composed of an incoherent source (LED), a line scan array detector, a specially selected diffuse reflecting surface, and several optical components. The EASDF, which is a modified correlation function, is able to calculate displacement between the probe and the object surface effectively even if there are inclinations, power fluctuations, and noises.

Kim, Kyung-Chan; Kim, Jong-Ahn; Oh, SeBaek; Kim, Soo Hyun; Kwak, Yoon Keun

2000-03-01

286

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.

287

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

Science.gov (United States)

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±0.7h, 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. PMID:22281049

de Bruyn, Warren J; Clark, Catherine D; Ottelle, Katherine; Aiona, Paige

2012-03-01

288

Elasticity of water-saturated rocks as a function of temperature and pressure.  

Science.gov (United States)

Compressional and shear wave velocities of water-saturated rocks were measured as a function of both pressure and temperature near the melting point of ice to confining pressure of 2 kb. The pore pressure was kept at about 1 bar before the water froze. The presence of a liquid phase (rather than ice) in microcracks of about 0.3% porosity affected the compressional wave velocity by about 5% and the shear wave velocity by about 10%. The calculated effective bulk modulus of the rocks changes rapidly over a narrow range of temperature near the melting point of ice, but the effective shear modulus changes gradually over a wider range of temperature. This phenomenon, termed elastic anomaly, is attributed to the existence of liquid on the boundary between rock and ice due to local stresses and anomalous melting of ice under pressure.

Takeuchi, S.; Simmons, G.

1973-01-01

289

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

290

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 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

291

Present Situation Research on Axial Flow Displacement Theory During Cementing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

292

A quantum mechanical study of water adsorption on the (110) surfaces of rutile SnO? and TiO?: investigating the effects of intermolecular interactions using hybrid-exchange density functional theory.  

Science.gov (United States)

Periodic hybrid-exchange density functional theory calculations are used to explore the first layer of water at model oxide surfaces, which is an important step for understanding the photocatalytic reactions involved in solar water splitting. By comparing the structure and properties of SnO2(110) and TiO2(110) surfaces in contact with water, the effects of structural and electronic differences on the water chemistry are examined. The dissociative adsorption mode at low coverage (1/7 ML) up to monolayer coverage (1 ML) on both SnO2 and TiO2(110) surfaces is analysed. To investigate further the intermolecular interactions between adjacent adsorbates, monolayer adsorption on each surface is explored in terms of binding energies and bond lengths. Analysis of the water adsorption geometry and energetics shows that the relative stability of water adsorption on SnO2(110) is governed largely by the strength of the chemisorption and hydrogen bonds at the surface of the adsorbate-substrate system. However on TiO2(110), a more complicated scenario of the first layer of water on its surface arises in which there is an interplay between chemisorption, hydrogen bonding and adsorbate-induced atomic displacements in the surface. Furthermore the projected density of states of each surface in contact with a mixture of adsorbed water molecules and adsorbed hydroxyls is presented and sheds some light on the nature of the crystalline chemical bonds as well as on why adsorbed water has often been reported to be unstable on rutile SnO2(110). PMID:24979063

Patel, M; Sanches, F F; Mallia, G; Harrison, N M

2014-10-21

293

Displaced proximal humeral fractures: an Indian experience with locking plates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 wi...

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

2010-01-01

294

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

295

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

296

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

297

Cardiorespiratory responses during deep water running with and without horizontal displacement at different cadences / Respostas cardiorrespiratórias durante a corrida em piscina funda com e sem deslocamento horizontal em diferentes ritmos / Respuestas cardiorrespiratorias de la carrera en aguas profundas con y sin desplazamiento horizontal y en diferentes cadencias  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: English Abstract in portuguese Objetivo: comparar as respostas cardiorrespiratórias durante corrida em piscina funda profunda com e sem deslocamento horizontal em diferentes ritmos. Métodos: Doze mulheres jovens realizaram corrida aquática com e sem deslocamento durante quatro minutos, em três ritmos distintos: a) 60 bpm; b) 80 b [...] pm; e c) 100 bpm. A frequência cardíaca (FC), ventilação (VE) e o consumo de oxigênio (VO2) foram coletados no último minuto de cada teste. Two-way ANOVA para medidas repetidas foi utilizada com o teste post hoc Bonferroni's (p Abstract in spanish Objetivo: comparar las respuestas cardiorrespiratorias durante la carrera en aguas profundas con y sin desplazamiento horizontal y a diferentes cadencias. Método: Doce mujeres jóvenes realizaron la carrera en aguas profundas con y sin desplazamiento durante cuatro minutos a tres cadencias diferentes [...] : a) 60 bpm, b) 80 bpm, y c) 100 bpm. La frecuencia cardíaca (FC), la ventilación (VE) y el consumo de oxígeno (VO2) se recogieron en el último minuto de cada prueba. ANOVA de dos vías para medidas repetidas con post hoc de Bonferroni (p Abstract in english Objective: To compare the cardiorespiratory responses during deep water running with and without displacement at different cadences. Methods: Twelve young women performed deep water running with and without displacement during 4 min at three separate cadences: (a) 60 bpm; (b) 80 bpm; and (c) 100 bpm [...] . The heart rate (HR), ventilation (Ve) and oxygen uptake (VO2) were collected in the last minute of each test. Two-way ANOVA for repeated measures was used with Bonferroni's post hoc test (p

A.C., Kanitz; G.V., Liedtke; S.S., Pinto; C.L., Alberton; L.F.M., Kruel.

2014-12-01

298

Understanding ceria/noble metal interactions for water -gas -shift catalysts using density functional theory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The water-gas-shift (WGS) reaction (CO + H2O ? H 2 + CO2) is important for CO removal. Ceria (CeO2) is an active potential support for WGS when combined with various metals (Pt, Au, Pd, Rh, Cu), and an understanding of the mechanism for WGS on ceria-supported catalysts is missing. Using density functional theory I have attempted to gain better understanding of ceria surfaces under WGS conditions. ^ Ceria-supported metals that are active for WGS are known to exist in a cationic form as...

Deskins, Nathaniel Aaron

2006-01-01

299

Comparison of Water Production Functions for Winter Wheat in Mashhad Region  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Ghahraman, B.; Nakhjavani Moghaddam, M. M.

2005-01-01

300

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

 
 
 
 
301

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

302

Conductance of Nafion 117 membranes as a function of temperature and water content  

Energy Technology Data Exchange (ETDEWEB)

The conductance of Nafion membranes was investigated by means of impedance spectroscopy as a function of temperature and of sample treatment. In addition to other treatments, the hot-pressing of Nafion membranes was also considered, because of its relevance for making membrane-electrode assemblies (MEA) for proton exchange membrane fuel cells (PEMFC). An Arrhenius-type analysis of the conductance shows two regimes, with a change in activation energy observed at transition temperatures between 225 and 260 K which depends on the water content

Cappadonia, Marcella; Wilhelm Erning, J.; Saberi Niaki, Seyedeh M.; Stimming, Ulrich [Institute of Energy Process Engineering IEV, Research Centre Juelich KFA, Juelich (Germany)

1995-04-01

303

Multiquadric and Compactly Supported Radial Basis Functions for Shallow Water Equations  

Science.gov (United States)

Meshfree methods have gained much attention in recent years, not only in the mathematics but also in the engineering community. The computer and numerical methods are powerful tools of analysing wide rang of engineering and industrial application. For long time researchers recognised problems when using a mesh-based method. Developing the meshless methods overcome these problems. In the present paper, we present the application of both the global and the compactly supported radial basis functions (CSRBFs) for solving a system of shallow water hydrodynamic model for marine environments. As the technique is based on the collocation formulation and does not require the generation of a grid and any integral evaluation, the technique is considered as purely meshless method. The Computational efficiency and accuracy of both used functions are verified by comparing the analytic and observed solution.

Alhuri, Y.; Taik, A.; Naji, A.

2009-04-01

304

Modeling the influence of irradiation temperature and displacement rate on hardening due to point defect clusters in ferritic steels  

International Nuclear Information System (INIS)

The influence of irradiation temperature and displacement rate have been investigated using a detailed kinetic model that incorporates an explicit description of point defect clustering. These clusters are potentially responsible for the fraction of the radiation-induced hardening that is attributed to the so-called ''matrix defect.'' The model considers both interstitial and vacancy clustering, with the former treated as Frank loops and the later treated as microvoids. The point defect clusters can be formed either directly in the displacement cascade or by diffusive encounters between free point defects. The results indicate that the assumption of steady state point defect concentrations is not valid for temperatures much below the light water reactor pressure vessel operating temperature of about 288 degrees C. At lower temperatures, the time required for the point defect concentrations to reach steady state can exceed an operating reactor's lifetime. Even at 288 degrees C, the length of the point defect transient could influence the interpretation of irradiation experiments conducted at accelerated damage rates. The hardening due to point defect clusters was calculated using a simple dislocation barrier model. The model predicts that both cluster types can give rise to significant hardening. The relative importance of each type is shown to be a function of irradiation temperature and displacement rate

305

Digital image correlation using energy minimization in full-field displacement and strain measurement  

Science.gov (United States)

Digital image correlation (DIC) method is an effective way for full-field strain measurement. Optical flow estimation methods combined with a global searching strategy for displacement field measurement are introduced in this paper. Compared with the conventional DIC method, this strategy can lessen possible mismatching between the reference image and warped image. By minimization the energy function of displacement field, displacement continuity and displacement gradients continuity among calculation points are achieved. For detecting large displacements, a coarse-tofine strategy is also employed. More importantly, the architecture parallelization of optical flow estimation and searching strategy can decrease the running time of this method for time-critical conditions. This proposed method is universally applicable to the images with shadows, rotation, and large deformation. Several pairs of simulated digital speckle images were used to evaluate the performance of this novel DIC method, and the experimental results clearly demonstrate its robustness and effectiveness.

Huo, Xing; Cheng, Teng; Tan, Jieqing; Gao, Yue; Cai, Yulong

2013-06-01

306

Water of coconut: Nutritional and functional properties and processing/
Água-de-coco: Propriedades nutricionais, funcionais e processamento
 

Digital Repository Infrastructure Vision for European Research (DRIVER)

This review presents the important aspects of the coconut water, such as its chemical composition, nutritional value and functional properties, which allied to its sweetened taste, turned it into a much appreciated beverage, favoring the increase of its consumption. It also reports the types of commercialization of the coconut water and the related aspects of the industrialization of the coconut water, balancing the offer of green coconut along the year. The important factors during the indus...

Geraldo Arraes Maia Junior; Paulo Henrique Machado de Sousa; Geraldo Arraes Maia; Joelia Marques Carvalho

2006-01-01

307

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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

308

Study of the diacetamide-water dimer with ab initio and density functional theory methods  

International Nuclear Information System (INIS)

The hydrogen bonding of 1:1 complexes formed between diacetamide and water molecule have been completely investigated in the present study using density functional theory and second order Moller-Plesset perturbation (MP2) method. The large basis sets 6-311++g(d,p) and 6-311++g(2d,2p) have been employed to determine the equilibrium structure of the interacting complexes. All the results reveal a planar configuration of the amide groups and a tendency of the CH3 group to eclipse the C=O bond for the geometry of the isolated diacetamide molecule. Calculations at different theoretical levels indicate that cis-trans configuration is the most stable isomer in both gas phase and solution phase. Three reasonable geometries on the potential energy hypersurface of diacetamide with water system are considered with the global minimum being a cyclic double-hydrogen bonded structure. The optimized geometric parameters and interaction energies for various isomers at different levels are estimated and a result that two carbonyl groups have about the same proton acceptor ability has been obtained. Finally, the solution phase studies are also carried out using the onsager reaction field model at B3LYP/6-311++g** level for the isolated diacetamide molecule and the hydrogen-bonded complex of diacetamide with water. The results indicate the polarity of the solvent has played an important role on the structures and relative stabilities of different isomersf different isomers

309

Objective determination of the water level in frequency-domain deconvolution for receiver function analysis  

Science.gov (United States)

Deconvolution is the central operation carried out in teleseismic receiver function (RF) analysis. It transforms the recorded teleseismic signal into the Earth's impulse response by effectively removing the source and instrument responses from this signal. The operation can be carried out either in the time domain or in the frequency domain. Time-domain deconvolution is generally more computationally intensive, but it allows for automatic convergence towards a stable solution (i.e., an RF devoid of ringing) for noisy data. Frequency-domain deconvolution is faster to compute, but it often requires user input to find the optimal regularization/water-level parameter that yields a stable solution. In this study, we investigate ways to objectively determine the optimal water level parameter for frequency-domain deconvolution of teleseismic RFs. Using synthetic and field data, we compare various optimization schemes with L-curves that provide a tradeoff between the root-mean-square error, L2-norm, signal sparseness and spectral flatness of the computed RF. We find that maximising the spectral flatness of the computed RF is the best way to find the optimum water level. Applications to field data from central and northern Norway illustrate the viability of this objective optimization scheme. The resulting RF profiles show clear signals from the Moho (with relief associated with the central Scandes) as well as from the 410 and 660 km-discontinuities below Norway.

Halpaap, Felix; Spieker, Kathrin; Rondenay, Stéphane

2014-05-01

310

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

311

Instability in Immiscible Fluids Displacement from Cracks and Porous Samples  

Science.gov (United States)

problems of terrestrial engineering and technology. Surface tension affected flows in porous media could be much better understood in microgravity studies eliminating the masking effects of gravity. Saffman-Taylor instability of the interface could bring to formation and growth of "fingers" of gas penetrating the bulk fluid. The growth of fingers and their further coalescence could not be described by the linear analysis. Growth of fingers causes irregularity of the mixing zone. The tangential velocity difference on the interface separating fluids of different densities and viscousities could bring to a Kelvin-Helmholtz instability resulting in "diffusion of fingers" partial regularization of the displacement mixing zone. Thus combination of the two effects would govern the flow in the displacement process. fracture under a pressure differential displacing the high viscosity residual fracturing fluid. There are inherent instability and scalability problems associated with viscous fingering that play a key role in the cleanup procedure. Entrapment of residual fracturing fluid by the gas flow lowers down the quality of a fracture treatment leaving most of fluid in the hydraulic fracture thus decreasing the production rate. The gravity effects could play essential role in vertical hydraulic fractures as the problem is scale dependent. displacement of viscous fluid by a less viscous one in a two-dimensional channel with vertical breaks, and to determine characteristic size of entrapment zones. Extensive direct numerical simulations allow to investigate the sensitivity of the displacement process to variation of values of the main governing parameters. were found for the two limiting cases: infinitely wide cell, and narrow cell with an infinitely small gap between the finger and the side walls. governing parameters. The obtained solutions allowed to explain the physical meaning of the exiting empirical criteria for the beginning of viscous fingering and the growth of a number of fingers in the cell, and allowed us to make some additional suggestions for the cleanup procedure. depending on the resident fluid properties, for which the displacement still remains stable. viscous one were carried out. Validation of the code was performed by comparing the results of model problems simulations with the existing solutions published in literature. Being in a good agreement with the previously obtained results, nevertheless, the developed code is an advanced one. While the existing codes could operate with linear equations and regular geometry and initial disturbances only, the new code permits taking into account non-linear effects as well. characterizing the quality of displacement. The functional dependence of the dimensionless criteria on the values of governing parameters needs further investigations. Services, an international company in the oil and gas industry.

Smirnov, N. N.; Nikitin, V. F.; Ivashnyov, O. E.

2002-01-01

312

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

Science.gov (United States)

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 demographics. A THM level was estimated for each cycle based on residence and quarterly measurements made by water utilities during a 90-day period beginning 60 days before the cycle start date. We found a monotonic decrease in mean cycle length with increasing total THM (TTHM) level; at > 60 microg/L, the adjusted decrement was 1.1 days [95% confidence interval (CI), -1.8 to -0.40], compared with less than or equal to 40 microg/L. This finding was also reflected as a reduced follicular phase length (difference -0.94 day; 95% CI, -1.6 to -0.24). A decrement in cycle and follicular phase length of 0.18 days (95% CI, -0.29 to -0.07) per 10 microg/L unit increase in TTHM concentration was found. There was little association with luteal phase length, menses length, or cycle variability. Examining the individual THMs by quartile, we found the greatest association with chlorodibromomethane or the sum of the brominated compounds. Incorporating tap water consumption showed a similar pattern of reduced cycle length with increasing TTHM exposure. These findings suggest that THM exposure may affect ovarian function and should be confirmed in other studies. PMID:12782495

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

2003-06-01

313

Water permeability of the mammalian cochlea: functional features of an aquaporin-facilitated water shunt at the perilymph–endolymph barrier  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The cochlear duct epithelium (CDE) constitutes a tight barrier that effectively separates the inner ear fluids, endolymph and perilymph, thereby maintaining distinct ionic and osmotic gradients that are essential for auditory function. However, in vivo experiments have demonstrated that the CDE allows for rapid water exchange between fluid compartments. The molecular mechanism governing water permeation across the CDE remains elusive. We computationally determined the diffusional (PD) and osm...

Eckhard, A.; Mu?ller, M.; Salt, A.; Smolders, J.; Rask-andersen, H.; Lo?wenheim, H.

2014-01-01

314

Water  

...gr Interests: surface hydrology; water resources management and engineering; climate change impacts on hydrology and water resources; extreme hydrological events (...edu Interests: surface water/groundwater interactions; stable isotope hydrology; human impacts on water resources; wastewater; environmental geology * Section 'Groundwater' ...edu Interests: watershed hydrology; coastal hydrology; erosion and sediment transport; water quality; GIS and RS applications in water resources *...WF_ID=126 Interests: hydrology; vadose zone; soil physics; scaling; terrain; soil water; watershed modeling; global change Dr....

315

Understanding the interaction of water with anatase TiO2 (101) surface from density functional theory calculations  

International Nuclear Information System (INIS)

The behavior of water molecule on anatase TiO2 (101) surface has been investigated by density functional theory calculations. The primary purpose of this Letter is to clarify the distinctions between molecular adsorption and dissociative adsorption of water on anatase TiO2 (101) surface. By analyzing interaction potential forms and bonding mechanism, it is found that the dipole interaction is the crucial factor for water adsorption on anatase TiO2 (101) surface. The adiabatic potential energy surface calculations indicate that the on-surface diffusion of water molecule is anisotropy: its diffusion energy barrier along [010] direction is smaller than that of along [111-bar]/[11-bar 1-bar] direction. -- Highlights: ? We model the water adsorption on anatase TiO2 (101) surface. ? Water favors molecular adsorption to dissociation adsorption on this surface. ? The dipole interaction cannot be ignored in this case. ? The on-surface diffusion of water molecule is anisotropy.

316

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

317

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

318

Assisting the return of displaced Dinka Bor  

Directory of Open Access Journals (Sweden)

Full Text Available The issues involved in supporting the return of internally displaced Dinka Bor communities highlight the complex, and often ignored, challenges of addressing the consequencesof South-South conflict.

Paul Murphy

2005-11-01

319

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

320

Determining the impacts of trawling on benthic function in European waters : a biological traits approach  

DEFF Research Database (Denmark)

One of the most widespread yet manageable pressures we impose on the seabed is disturbance of the substrate by towed demersal fishing gear (bottom trawling and dredging). Over the past forty to fifty years, many studies have been conducted specifically aiming to understand the impacts of such fishing gear on the seabed communities. Their outcomes have demonstrated dramatic effects of bottom trawling on the structure of marine ecosystems although impacts tend to be wide-ranging, depending upon the gear, intensity, spatial area and the nature of the seabed habitats. However, understanding the functional impacts of this activity (as opposed to impacts on the structure of benthic assemblages) has only recently been attempted. Advances in the application of biological traits analysis (BTA) wherein the assemblages are described in terms of their life history, behavioural and morphological characteristics, have allowed us to better understand the interactions between the benthic fauna and their environment at a functional level. We present the initial findings of work conducted under the auspices of the EU-funded project ‘BENTHIS’ which aims to improve our understanding of the impacts of trawling on benthic ecosystem functioning over much larger spatial scales than previously undertaken. Biological traits information from 887 stations across European waters (Norwegian, UK, Belgian, Dutch, Danish waters, the Mediterranean and Black Sea) were analysed to: i) quantify the relationships between infaunal trait composition and environmental variables (depth, sediment granulometry); ii) determine the relationship between traits and habitat type (EUNIS level 4); and iii) assess the relationships between trawling pressure (using data derived under BENTHIS; see Eigaard et al., this volume) and traits composition

Bolam, Stefan; Kenny, Andrew

 
 
 
 
321

New hypotheses about the structure-function of proprotein convertase subtilisin/kexin type 9: analysis of the epidermal growth factor-like repeat A docking site using WaterMap.  

Science.gov (United States)

LDL cholesterol (LDL-C) is cleared from plasma via cellular uptake and internalization processes that are largely mediated by the low-density lipoprotein cholesterol receptor (LDL-R). LDL-R is targeted for lysosomal degradation by association with proprotein convertase subtilisin-kexin type 9 (PCSK9). Gain of function mutations in PCSK9 can result in excessive loss of receptors and dyslipidemia. On the other hand, receptor-sparing phenomena, including loss-of-function mutations or inhibition of PCSK9, can lead to enhanced clearance of plasma lipids. We hypothesize that desolvation and resolvation processes, in many cases, constitute rate-determining steps for protein-ligand association and dissociation, respectively. To test this hypothesis, we analyzed and compared the predicted desolvation properties of wild-type versus gain-of-function mutant Asp374Tyr PCSK9 using WaterMap, a new in silico method for predicting the preferred locations and thermodynamic properties of water solvating proteins ("hydration sites"). We compared these results with binding kinetics data for PCSK9, full-length LDL-R ectodomain, and isolated EGF-A repeat. We propose that the fast k(on) and entropically driven thermodynamics observed for PCSK9-EGF-A binding stem from the functional replacement of water occupying stable PCSK9 hydration sites (i.e., exchange of PCSK9 H-bonds from water to polar EGF-A groups). We further propose that the relatively fast k(off) observed for EGF-A unbinding stems from the limited displacement of solvent occupying unstable hydration sites. Conversely, the slower k(off) observed for EGF-A and LDL-R unbinding from Asp374Tyr PCSK9 stems from the destabilizing effects of this mutation on PCSK9 hydration sites, with a concomitant increase in the persistence of the bound complex. PMID:20589640

Pearlstein, Robert A; Hu, Qi-Ying; Zhou, Jing; Yowe, David; Levell, Julian; Dale, Bethany; Kaushik, Virendar K; Daniels, Doug; Hanrahan, Susan; Sherman, Woody; Abel, Robert

2010-09-01

322

Displacement error correction in sorting systems  

International Nuclear Information System (INIS)

In radiometric sorting a method of compensating for the count recorded by a detector for an ore particle which is displaced from the centre line of the detector. The compensation is effected by applying one of a plurality of calibration factors to the detector count. The calibration factors are statistically determined and are dependent on the measured displacement and optionally on at least one of the shape, height, volume or mass of the particle

323

Explanation of Displacement Current in a Vacuum  

CERN Document Server

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, P

2006-01-01

324

Pump adjustment system design for displacement control  

Digital Repository Infrastructure Vision for European Research (DRIVER)

One of the key enabling technologies required for successful commercialization of displacement controlled (DC) systems are the appropriate variable displacement pumps. This thesis aims to fill the current gap in literature with respect to the performance requirements of pumps used in DC systems as well as create a methodology to ensure a compact, low power, and low cost pump adjustment system design. This research looks both at the design considerations with respect to the individual componen...

Rose, Jess B.

2011-01-01

325

Soil Structure Interaction in Displacement Based Design  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

326

Comb-drive actuators for large displacements  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The design, fabrication and experimental results of lateral-comb-drive actuators for large displacements at low driving voltages is presented. A comparison of several suspension designs is given, and the lateral large deflection behaviour of clamped - clamped beams and a folded flexure design is modelled. An expression for the axial spring constant of folded flexure designs including bending effects from lateral displacements, which reduce the axial stiffness, is also derived. The maximum def...

Legtenberg, Rob; Groeneveld, A. W.; Elwenspoek, M.

1996-01-01

327

The intergenerational effects of worker displacement  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

328

Digital image correlation: displacement accuracy estimation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this collaborative work is to study the uncertainties associated with Digital Image Correlation techniques (DIC). More specifically, the link between displacement uncertainties and several correlation parameters chosen by the user and relative to the image analysis software and several image characteristics like speckle size and image noise is emphasized. A previous work [1] has been done for situations with spatially fluctuating displacement fields which dealt with mismatch error ...

Wattrisse B.; Bornert M.; Dupré J.C.; Robert L

2010-01-01

329

Myocardial strains from 3D displacement encoded magnetic resonance imaging  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The ability to measure and quantify myocardial motion and deformation provides a useful tool to assist in the diagnosis, prognosis and management of heart disease. The recent development of magnetic resonance imaging methods, such as harmonic phase analysis of tagging and displacement encoding with stimulated echoes (DENSE, make detailed non-invasive 3D kinematic analyses of human myocardium possible in the clinic and for research purposes. A robust analysis method is required, however. Methods We propose to estimate strain using a polynomial function which produces local models of the displacement field obtained with DENSE. Given a specific polynomial order, the model is obtained as the least squares fit of the acquired displacement field. These local models are subsequently used to produce estimates of the full strain tensor. Results The proposed method is evaluated on a numerical phantom as well as in vivo on a healthy human heart. The evaluation showed that the proposed method produced accurate results and showed low sensitivity to noise in the numerical phantom. The method was also demonstrated in vivo by assessment of the full strain tensor and to resolve transmural strain variations. Conclusions Strain estimation within a 3D myocardial volume based on polynomial functions yields accurate and robust results when validated on an analytical model. The polynomial field is capable of resolving the measured material positions from the in vivo data, and the obtained in vivo strains values agree with previously reported myocardial strains in normal human hearts.

Kindberg Katarina

2012-04-01

330

5 CFR 330.706 - Notification of displaced employees.  

Science.gov (United States)

... Notification of displaced employees. 330.706 Section 330...Assistance Plan for Displaced Employees § 330.706 Notification of displaced employees. (a) In addition to meeting the requirements of §...

2010-01-01

331

An Assessment of Relationship Between Arsenic in Drinking Water, Health Status and Intellectual Functioning of Children in District Kasur  

Directory of Open Access Journals (Sweden)

Full Text Available In this study determination of arsenic (As contamination in the drinking water and urine of children along with its effect on their health status and intellectual functioning was assessed. The study was carried out in order to determine any correlation between intake of arsenic and intellectual functioning level of the children. Raven Standard Progressive Matrices (RPM was administered on children of (8-15 years of age to assess their intellectual functioning and their health status was checked by measuring their height and weight. Water and urine sample were studied in both experimental and control group. In experimental area Arsenic level was above the World Health Organization (WHO permissible value which was compared with control area having arsenic level below WHO permissible value in both water and urine. An average 45% of arsenic level in drinking water samples was above WHO permissible value (10 ?g/L. Considering urinary arsenic as a biomarker of exposure to arsenic through drinking water, it was found that an average of 50% of children of the experimental group were found to have arsenic in their urine ranging from a concentration of 0.01-0.0119 ?g/L. Conclusively, this study showed that the intellectual functioning level of children drinking arsenic contaminated water was significantly lower as compared to those, drinking arsenic-free water.

Farooq Ahmad

2012-01-01

332

Thermal regulation of functional groups in running water ecosystems Technical progress report, October 1, 1976--June 30, 1977  

Energy Technology Data Exchange (ETDEWEB)

The research plan encompassed three general objectives: derivation of generalized models of detrital processing in stream ecosystems with special emphasis on thermal control; characterization of functional groups of running water organisms, particularly macroinvertebrates (shredders, collectors, scrapers, piercers, predators); and demonstration of the importance of food quality, and the interaction between temperature and food quality, in controlling growth and survivorship of stream functional groups.

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

1977-07-01

333

Regularized computation of interior displacements and stresses by BEM  

International Nuclear Information System (INIS)

The computation of interior displacements and stresses with the boundary element method (BEM) often requires the evaluation of nearly singular integrals. These integrals arise from the singular behaviour of the kernel functions in the Somigliana identity and the Somigliana stress identity. Treating them numerically in a standard way leads to inaccuracy near the boundary. This effect is always present in the calculation of field variables near the boundary and is called 'boundary layer effect'. In this paper regularization procedures are proposed which consist of an indirect evaluation of singular integrals and a special coordinate transformation. The proposed procedures eliminate the boundary layer effect for both, the calculation of displacements and stresses. In a numerical example of elastostatics the developed strategies are shown to work. Due to the generality of the proposed procedures they can be extended to any standard boundary element formulation for problems with bounded domains. (orig.)

334

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

335

Simulation of threshold displacements in NiAl  

Energy Technology Data Exchange (ETDEWEB)

Modified many-body interatomic potentials for modeling high-energy atomic collision in NiAl are constructed and described. The displacement threshold energy as a function of the primary recoil direction for Ni atoms and Al atoms in NiAl has been investigated by molecular dynamics simulations using the modified potentials. The defect structure induced by recoil events has been presented. The results show that the lowest threshold displacement energy, E{sub d}, is near the <1 0 0> orientation and the mean value of E{sub d} for an Al atom is higher than a Ni. A crowdion in the compact crystalline directions, <1 1 1>, incorporating an extra Ni atom is the stable interstitial configuration.

Wang Tianmin; Wang Yuexia; Wang Baoyi; Li Bo

1999-06-01

336

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

337

Gastric emptying of water in children with severe functional fecal retention  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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

338

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

339

Allosteric indicator displacement enzyme assay for a cyanogenic glycoside.  

Science.gov (United States)

Indicator displacement assays (IDAs) represent an elegant approach in supramolecular analytical chemistry. Herein, we report a chemical biosensor for the selective detection of the cyanogenic glycoside amygdalin in aqueous solution. The hybrid sensor consists of the enzyme ?-glucosidase and a boronic acid appended viologen together with a fluorescent reporter dye. ?-Glucosidase degrades the cyanogenic glycoside amygdalin into hydrogen cyanide, glucose, and benzaldehyde. Only the released cyanide binds at the allosteric site of the receptor (boronic acid) thereby inducing changes in the affinity of a formerly bound fluorescent indicator dye at the other side of the receptor. Thus, the sensing probe performs as allosteric indicator displacement assay (AIDA) for cyanide in water. Interference studies with inorganic anions and glucose revealed that cyanide is solely responsible for the change in the fluorescent signal. DFT calculations on a model compound revealed a 1:1 binding ratio of the boronic acid and cyanide ion. The fluorescent enzyme assay for ?-glucosidase uses amygdalin as natural substrate and allows measuring Michaelis-Menten kinetics in microtiter plates. The allosteric indicator displacement assay (AIDA) probe can also be used to detect cyanide traces in commercial amygdalin samples. PMID:24123550

Jose, D Amilan; Elstner, Martin; Schiller, Alexander

2013-10-18

340

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

 
 
 
 
341

Water in biological membranes at interfaces: does it play a functional role?  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: English Abstract in spanish El propósito de este trabajo es analizar la organización delaguaen la interfaz de una membrana biológica y su relevancia en las propiedades de superficie y en la adsorción de proteínas. El enfoque consiste en considerar que la función celular está confinada a un medio restringido en agua, el interio [...] r celular, en el cuaál la proximidad de la membrana puede ser clave para regular la actividad enzimática y la permeabilidad. Como la bicapa lipidica es la estructura básica de la membrana celular, los sitios de hidratación en la cabeza polar se analizan por medio de espectrometría infrarroja a transformada de Fourier. La contribución de la hidratación al potencial dipolar y la respuesta dinámica de monocapas de diferente composicioneslipídicas se investiganmediante determinación de potenciales de superficie yvoltametría cíclica. La modificación de esas propiedades a causa del reemplazo de agua por polioles como trehalosa y floretina y por la inserción de proteínas acuosolubles, ha sido también investigada. Abstract in english The purpose of this review is to examine and discuss the ways in which water is organized at the interface of a biological membrane. The relevance of this structure to the surface properties and to the adsorption of proteins in membranes is also analized. The approach is based on the idea that cell [...] functions are confined to a restricted water media, the cell interior, in which the proximity of the membrane may bekey to regulating the enzyme activity and the cell membrane permeability. As the lipid bilayer is the structural base ofcell membranes, the distribution of water in the surface sites of a phospholipid membrane is analyzed by means of Fourier Transform spectrometry. The polarization of water at the surface was looked into through the measure ofsurface potentials and the dynamics of the surface hydration by cyclic voltammetry. Modification of these properties by the replacement of water bypolyol molecules such as trehalose and phloretin and by the insertion of aqueous soluble enzymes, has also been investigated.

E. A., Disalvo; F., Lairion; F., Martini; H., Almaleck; S., Diaz; G., Gordillo.

2004-12-01

342

Water dissociation on alpha1-hafnium and ytterbium substituted Dawson polyoxotungstates: a density functional theory study.  

Science.gov (United States)

Density functional theory (DFT) calculations were devised to get insight into Lewis acidic catalysis by POMs, especially on the intriguing activation of complexed water molecules that was observed in some experimental cases. Computationally, it appears that deprotonation is feasible with [alpha(1)-Hf(H(2)O)P(2)W(17)O(61)](6-), but not with [alpha(1)-Yb(H(2)O)P(2)W(17)O(61)](7-). This reflects the difference of the electronic structures (diamagnetic for hafnium POM, paramagnetic for ytterbium POM). From a mechanistical point of view, indirect Brønsted catalysis cannot be excluded in the hafnium case, especially for Mannich reactions. But our calculations show that catalysis by [alpha(1)-Yb(H(2)O)P(2)W(17)O(61)](7-) (and presumably all the lanthanide series) proceeds through direct complexation of the substrates to the POM. PMID:18610951

Derat, Etienne; Lacôte, Emmanuel; Hasenknopf, Bernold; Thorimbert, Serge; Malacria, Max

2008-12-18

343

Graphene on ferromagnetic surfaces and its functionalization with water and ammonia  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract In this article, an angle-resolved photoelectron spectroscopy (ARPES, X-ray absorption spectroscopy (XAS, and density-functional theory (DFT investigations of water and ammonia adsorption on graphene/Ni(111 are presented. The results of adsorption on graphene/Ni(111 obtained in this study reveal the existence of interface states, originating from the strong hybridization of the graphene ? and spin-polarized Ni 3d valence band states. ARPES and XAS data of the H2O (NH3/graphene/Ni(111 system give an information regarding the kind of interaction between the adsorbed molecules and the graphene on Ni(111. The presented experimental data are compared with the results obtained in the framework of the DFT approach.

Voloshina Elena

2011-01-01

344

Temperature-modulated water filtration using microgel-functionalized hollow-fiber membranes.  

Science.gov (United States)

In the present work, we investigate the potential of aqueous polymer microgels in membrane technology, especially for filtration applications. The poly(N-vinylcaprolactam)-based microgels exhibit thermoresponsive behavior and were employed to coat hollow-fiber membranes used for micro- and ultrafiltration. We discuss the preparation of microgel-modified membranes (by "inside-out" as well as "outside-in" filtration in dead-end mode). The clean-water permeability and stability of these membranes was studied not only as a function of time, but also of temperature. The microgel-modified membranes exhibit a reversible thermoresponsive behavior whereby both the resistance and the retention increased with decreasing temperature. PMID:24740583

Menne, Daniel; Pitsch, Fee; Wong, John E; Pich, Andrij; Wessling, Matthias

2014-05-26

345

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)

346

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

347

Water permeability of the mammalian cochlea: functional features of an aquaporin-facilitated water shunt at the perilymph-endolymph barrier.  

Science.gov (United States)

The cochlear duct epithelium (CDE) constitutes a tight barrier that effectively separates the inner ear fluids, endolymph and perilymph, thereby maintaining distinct ionic and osmotic gradients that are essential for auditory function. However, in vivo experiments have demonstrated that the CDE allows for rapid water exchange between fluid compartments. The molecular mechanism governing water permeation across the CDE remains elusive. We computationally determined the diffusional (PD) and osmotic (Pf) water permeability coefficients for the mammalian CDE based on in silico simulations of cochlear water dynamics integrating previously derived in vivo experimental data on fluid flow with expression sites of molecular water channels (aquaporins, AQPs). The PD of the entire CDE (PD?=?8.18?×?10(-5) cm s(-1)) and its individual partitions including Reissner's membrane (PD?=?12.06?×?10(-5) cm s(-1)) and the organ of Corti (PD?=?10.2?×?10(-5) cm s(-1)) were similar to other epithelia with AQP-facilitated water permeation. The Pf of the CDE (Pf?=?6.15?×?10(-4) cm s(-1)) was also in the range of other epithelia while an exceptionally high Pf was determined for an epithelial subdomain of outer sulcus cells in the cochlear apex co-expressing AQP4 and AQP5 (OSCs; Pf?=?156.90?×?10(-3) cm s(-1)). The Pf/PD ratios of the CDE (Pf/PD?=?7.52) and OSCs (Pf/PD?=?242.02) indicate an aqueous pore-facilitated water exchange and reveal a high-transfer region or "water shunt" in the cochlear apex. This "water shunt" explains experimentally determined phenomena of endolymphatic longitudinal flow towards the cochlear apex. The water permeability coefficients of the CDE emphasise the physiological and pathophysiological relevance of water dynamics in the cochlea in particular for endolymphatic hydrops and Ménière's disease. PMID:24385019

Eckhard, A; Müller, M; Salt, A; Smolders, J; Rask-Andersen, H; Löwenheim, H

2014-10-01

348

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

349

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

International Nuclear Information System (INIS)

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 requency 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.

350

Dry under water: comparative morphology and functional aspects of air-retaining insect surfaces.  

Science.gov (United States)

Superhydrophobic surfaces prevent certain body parts of semiaquatic and aquatic insects from getting wet while submerged in water. The air layer on these surfaces can serve the insects as a physical gill. Using scanning electron microscopy, we investigated the morphology of air-retaining surfaces in five insect species with different levels of adaptation to aquatic habitats. We found surfaces with either large and sparse hairs (setae), small and dense hairs (microtrichia), or hierarchically structured surfaces with both types of hairs. The structural parameters and air-film persistence of these surfaces were compared. Air-film persistence varied between 2 days in the beetle Galerucella nymphaea possessing only sparse setae and more than 120 days in the bugs Notonecta glauca and Ilyocoris cimicoides possessing dense microtrichia (up to 6.6 × 10(6) microtrichia per millimeter square). From our results, we conclude that the density of the surface structures is the most important factor that affects the persistence of air films. Combinations of setae and microtrichia are not decisive for the overall persistence of the air film but might provide a thick air store for a short time and a thin but mechanically more stable air film for a long time. Thus, we assume that a dense cover of microtrichia acts as a "backup system" preventing wetting of the body surface in case the air-water interface is pressed toward the surface. Our findings might be beneficial for the development of biomimetic surfaces for long-term air retention and drag reduction under water. In addition, the biological functions of the different air retention capabilities are discussed. PMID:21290417

Balmert, Alexander; Florian Bohn, Holger; Ditsche-Kuru, Petra; Barthlott, Wilhelm

2011-04-01

351

Improved methodology for the preparation of water-soluble maleimide-functionalized small gold nanoparticles.  

Science.gov (United States)

Improved methodology to prepare maleimide-functionalized, water-soluble, small (Alder strategy that we developed for similar organic-soluble AuNP's is described. Importantly, our results suggest that a recent paper by Zhu, Waengler, Lennox, and Schirrmacher describing a similar strategy gave results inconsistent with the formation of the titled maleimide-modified AuNP (Zhu, J.; Waengler, C.; Lennox, R. B.; Schirrmacher, R. Langmuir2012, 28, 5508) as the major product, but consistent with the major product being an adduct derived from the hydrolysis of maleimide formed under the conditions used for the required deprotection of the maleimide. Our methodology provides an efficient and accessible route to pure maleimide-modified small AuNP's that circumvents the formation of the hydrolysis product. The maleimide-modified small AuNP's are versatile because they are soluble in water and in a wide range of organic solvents and their reactivity can now be properly exploited as a reactive moiety in Michael addition for bioconjugation studies in aqueous solution. PMID:22881999

Gobbo, Pierangelo; Workentin, Mark S

2012-08-21

352

Water adsorption on SrTiO3(001): A density-functional theory study  

International Nuclear Information System (INIS)

SrTiO3 is a technological oxide, with applications as photo-catalyst, gas-sensor or as substrate for film growth. In many of these applications the surface of SrTiO3 is deliberately or unintended in contact with water molecules. Aiming for the atomic-scale details of this interaction we perform density-functional theory calculations addressing the adsorption of H2O on both regular terminations of the SrTiO3(001) surface. We find that the binding energetics is crucially controlled by long-range surface relaxations. Using this energetics to construct a thermodynamic phase diagram we obtain a different propensity for hydroxylation of the two terminations that is consistent with recent experiments by Iwahori et al. Around room temperature the SrO-termination becomes hydroxylated already at lowest background humidity, whereas the TiO2-terminated domains stay practically water-free in the range of low and moderate H2O vapor pressures.

353

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

354

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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

355

Nanoporous membranes with cellulose nanocrystals as functional entity in chitosan: removal of dyes from water.  

Science.gov (United States)

Fully biobased composite membranes for water purification were fabricated with cellulose nanocrystals (CNCs) as functional entities in chitosan matrix via freeze-drying process followed by compacting. The chitosan (10 wt%) bound the CNCs in a stable and nanoporous membrane structure with thickness of 250-270 ?m, which was further stabilized by cross-linking with gluteraldehyde vapors. Scanning electron microscopy (SEM) studies revealed well-individualized CNCs embedded in a matrix of chitosan. Brunauer, Emmett and Teller (BET) measurements showed that the membranes were nanoporous with pores in the range of 13-10nm. In spite of the low water flux (64 Lm(-2) h(-1)), the membranes successfully removed 98%, 84% and 70% respectively of positively charged dyes like Victoria Blue 2B, Methyl Violet 2B and Rhodamine 6G, after a contact time of 24h. The removal of dyes was expected to be driven by the electrostatic attraction between negatively charged CNCs and the positively charged dyes. PMID:25129796

Karim, Zoheb; Mathew, Aji P; Grahn, Mattias; Mouzon, Johanne; Oksman, Kristiina

2014-11-01

356

Multihydroxy dendritic upconversion nanoparticles with enhanced water dispersibility and surface functionality for bioimaging.  

Science.gov (United States)

Upconversion nanoparticle (UCNP) as a new class of imaging agent is gaining prominence because of its unique optical properties. An ideal UCNP for bioimaging should simultaneously possess fine water dispersibility and favorable functional groups. In this paper, we present a simple but effective method to the synthesis of a UCNP-based nanohybrid bearing a multihydroxy hyperbranched polyglycerol (HPG) shell by the combination of a "grafting from" strategy with a ring-opening polymerization technique. The structure and morphology of the resulting UCNP-g-HPG nanohybrid were characterized in detail by Fourier transform infrared, (1)H NMR, thermogravimetric analysis, and transmission electron microscopy measurements. The results reveal that the amount of grafted HPG associated with the thickness of the HPG shell can be well tuned. UCNP-g-HPG shows high water dispersibility and strong and stable upconversion luminescence. On the basis of its numerous surface hydroxyl groups, UCNP-g-HPG can be tailored by a representative fluorescent dye rhodamine B to afford a UCNP-g-HPG-RB nanohybrid that simultaneously presents upconversion and downconversion luminescence. Preliminary biological studies demonstrate that UCNP-g-HPG shows low cytotoxicity, high luminescent contrast, and deep light penetration depth, posing promising potential for bioimaging applications. PMID:24749852

Zhou, Li; He, Benzhao; Huang, Jiachang; Cheng, Zehong; Xu, Xu; Wei, Chun

2014-05-28

357

Density functional theory study on water-gas-shift reaction over molybdenum disulfide  

DEFF Research Database (Denmark)

Density functional theory calculations have been carried out to investigate the adsorption of reaction intermediates appearing during water-gas-shift reaction at the sulfur covered MoS2 (1 0 0)surfaces, Mo-termination with 37.5% S coverage and S-termination with 50% S coverage using periodic slabs. The pathway for water-gas-shift reaction on both terminations has been carefully studied where the most favorable reaction path precedes the redox mechanism, namely the reaction takes place as follows: CO + H2O --> CO + OH + H --> CO + O + 2H --> CO2 + H-2. The most likely reaction candidates for the formate species HCOO formation is the surface CO2 reaction with H as a side reaction of CO2 desorption on S-termination with 50% S coverage. The formed HCOO species will react further with adsorbed hydrogen yielding H2COO followed by breaking its C-O bond to form the surface CH2O and O species.

Shi, X. R.; Wang, Shengguang

2009-01-01

358

Surgical treatment of displaced acetabular fractures  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction. Acetabular fractures are severe injuries, generally caused by high-energy trauma, most frequently from traffic accidents or falls from heights. Fractures of the extremities, head injuries, chest, abdomen and pelvic ring injuries are most commonly associated injuries. Objective. The purpose of this study was to evaluate the results of open reduction and internal fixation of acetabular fractures. The open anatomical reduction of the articular surface combined with a rigid internal fixation and early mobilisation have become the standard treatment of these injuries. Methods. We conducted a retrospective analysis of 22 patients of average age 43.13 years. The patients were treated by open reduction and internal fixation at the Orthopaedic Clinic of Niš from 2005-2009. The follow-up was 12 to 60 months, with the average of 21.18 months after surgery. Results. All injured patients were operated on between 4 and 11 days (5.7 days on the average. According to the classification by Judet and Letournel, 15 (68.18% patients had an elementary acetabular fracture, whereas 7 (31.82% patients had associated fracture. A satisfactory postoperative reduction implying less than 2 mm of displacement was achieved in 19 (86.36% patients. The radiological status of the hip joint, determined according to Matta score, was excellent in 15 (68.18% patients, good in 4 (18.18% patients and moderate in 3 (13.63% patients. According to Merle d’Aubigné Scale, the final functional results of the treatment of all operated patients were excellent in 12 (54.54% patients, good in 7 (31.81% patients and moderate in 3 (13.63% patients. Conclusion. Surgical treatment of dislocated acetabular fractures requires an open reduction and a stable internal fixation. Excellent and good results can be expected only if anatomical reduction and stable internal fixation are achieved.

Milenkovi? Saša

2011-01-01

359

Electronic Transport in Dual-Gated Bilayer Graphene at Large Displacement Fields  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study the electronic transport properties of dual-gated bilayer graphene devices. We focus on the regime of low temperatures and high electric displacement fields, where we observe a clear exponential dependence of the resistance as a function of displacement field and density, accompanied by a strong non-linear behavior in the transport characteristics. The effective transport gap is typically two orders of magnitude smaller than the optical band gaps reported by infrare...

Taychatanapat, Thiti; Jarillo-herrero, Pablo

2010-01-01

360

An Intensity-Modulated Optical Fibre Displacement Sensor with Convex Reflector  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A novel intensity-modulated optical fibre displacement sensor with convex reflector technology is described. A common form of the intensity-modulated optical fibre sensor performs its measurement by making use of a pair of straight optical fibres with a plane reflector. The reflected optical signal intensity changes as a function of change in displacement. This paper describes an alternative sensing structure with a convex reflector instead of a plane reflector and demonstrates the derivation...

Gaikwad, A. D.; Gawande, J. P.; Joshi, A. K.; Chile, R. H.

2013-01-01

 
 
 
 
361

Proximal humeral fractures : Aspects of treatment with special reference to displaced fractures in the elderly  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Proximal Humeral Fractures Aspects of treatment with special reference to displaced fractures in the elderly Karol Zyto From the Departments of Orthopaedic Surgery, Söder Hospital, Karolinska Institute, Stockholm, and University Hospital, Umeå University, Sweden The purpose of this thesis was to study the clinical and functional outcome after various treatments of displaced fractures of the proximal humerus in an elderly patient group. Conservative treatment c...

Zyto, Karol

1997-01-01

362

Capillary rise quantifications based on in-situ artificial deuterium peak displacement and laboratory soil characterization  

Directory of Open Access Journals (Sweden)

Full Text Available In arid environments, water rises from the saturated level of a shallow aquifer to the drying soil surface where evaporation occurs. This process plays important roles in terms of plant survival, salt balance and aquifer budget. A new field quantification method of this capillary rise flow is proposed using micro-injections (6 ?L of a deuterium-enriched solution (? value of 63 000‰ vs. V-SMOW into unsaturated soil at a 1 m depth. Evaluation of peak displacement from profile sampling 35 days later delivered an estimate that was compared with outputs of numerical simulation based on laboratory hydrodynamic measurements assuming a steady state regime. A rate of 3.7 cm y?1 was estimated at a Moroccan site, where the aquifer water depth was 2.44 m. This value was higher than that computed from the relationship between evaporation rates and water level depth based on natural isotopic profile estimates, but it was lower than every estimate established using integration of the van Genuchten closed-form functions for soil hydraulic conductivity and retention curve.

O. Grünberger

2011-05-01

363

Capillary rise quantifications based on in-situ artificial deuterium peak displacement and laboratory soil characterization  

Science.gov (United States)

In arid environments, water rises from the saturated level of a shallow aquifer to the drying soil surface where evaporation occurs. This process plays important roles in terms of plant survival, salt balance and aquifer budget. A new field quantification method of this capillary rise flow is proposed using micro-injections (6 ?L) of a deuterium-enriched solution (? value of 63 000‰ vs. V-SMOW) into unsaturated soil at a 1 m depth. Evaluation of peak displacement from profile sampling 35 days later delivered an estimate that was compared with outputs of numerical simulation based on laboratory hydrodynamic measurements assuming a steady state regime. A rate of 3.7 cm y-1 was estimated at a Moroccan site, where the aquifer water depth was 2.44 m. This value was higher than that computed from the relationship between evaporation rates and water level depth based on natural isotopic profile estimates, but it was lower than every estimate established using integration of the van Genuchten closed-form functions for soil hydraulic conductivity and retention curve.

Grünberger, O.; Michelot, J. L.; Bouchaou, L.; Macaigne, P.; Hsissou, Y.; Hammecker, C.

2011-05-01

364

Conflict induced internal displacement in Nepal.  

Science.gov (United States)

Nepal has witnessed a humanitarian crisis since the Maoist conflict began ten years ago. The plight of internally displaced persons (IDPs) in Nepal has received little international attention despite being rated one of the worst displacement scenarios in the world. An estimated 200,000 people have been displaced as a result of the conflict, with the far-western districts of Nepal being the worst affected. Internal displacement has stretched the carrying capacity of several cities with adverse physical and mental health consequences for the displaced. Vulnerable women and children have been the worst affected. The government has adopted a discriminatory approach and failed to fulfil its obligations towards IDPs. Non-governmental organisations and international agencies have provided inadequate services to IDPs in their programmes. Tackling the issues of IDPs requires co-operation between government and development agencies: acknowledging the burden of the problem of IDPs, adequate registration and needs assessment, along with health and nutritional surveys, and development of short-term emergency relief packages and long-term programmes for their assistance. PMID:17542185

Singh, Sonal; Sharma, Sharan Prakash; Mills, Edward; Poudel, Krishna C; Jimba, Masamine

2007-01-01

365

Wavelet denoising of displacement estimates in elastography.  

Science.gov (United States)

Wavelet shrinkage denoising of the displacement estimates to reduce noise artefacts, especially at high overlaps in elastography, is presented in this paper. Correlated errors in the displacement estimates increase dramatically with an increase in the overlap between the data segments. These increased correlated errors (due to the increased correlation or similarity between consecutive displacement estimates) generate the so-called "worm" artefact in elastography. However, increases in overlap on the order of 90% or higher are essential to improve axial resolution in elastography. The use of wavelet denoising significantly reduces errors in the displacement estimates, thereby reducing the worm artefacts, without compromising on edge (high-frequency or detail) information in the elastogram. Wavelet denoising is a term used to characterize noise rejection by thresholding the wavelet coefficients. Worm artefacts can also be reduced using a low-pass filter; however, low-pass filtering of the displacement estimates does not preserve local information such as abrupt change in slopes, causing the smoothing of edges in the elastograms. Simulation results using the analytic 2-D model of a single inclusion phantom illustrate that wavelet denoising produces elastograms with the closest correspondence to the ideal mechanical strain image. Wavelet denoising applied to experimental data obtained from an in vitro thermal lesion phantom generated using radiofrequency (RF) ablation also illustrates the improvement in the elastogram noise characteristics. PMID:15121250

Techavipoo, Udomchai; Varghese, Tomy

2004-04-01

366

Density functional for van der Waals forces accounts for hydrogen bond in benchmark set of water hexamers  

DEFF Research Database (Denmark)

A recent extensive study has investigated how various exchange-correlation (XC) functionals treat hydrogen bonds in water hexamers and has shown traditional generalized gradient approximation and hybrid functionals used in density-functional (DF) theory to give the wrong dissociation-energy trend of low-lying isomers and van der Waals (vdW) dispersion forces to give key contributions to the dissociation energy. The question raised whether functionals that incorporate vdW forces implicitly into the XC functional predict the correct lowest-energy structure for the water hexamer and yield accurate total dissociation energy is here answered affirmatively for the vdW-DF [M. Dion , Phys. Rev. Lett.92, 246401 (2004)].

Kelkkanen, Kari André; Lundqvist, Bengt

2009-01-01

367

European pressurized water reactor configuration, functional requirements and efficiency of the safety injection system  

International Nuclear Information System (INIS)

The paper presents the thermal-hydraulic behavior of the European Pressurized Water Reactor (EPR) under LOCA conditions and demonstrates the efficiency of EPR's Safety Injection System (SIS). Safety criteria as well as performance of the SIS - i.e., main functions, functional requirements, design and emergency core cooling mode - are discussed. The thermal-hydraulic response of the EPR to various LOCAs was analyzed by performing best-estimate or conservative LOCA-calculations with the advanced computer codes CATHARE, RELAP5/MOD2 and SPC-RELAP5. A large spectrum of leak sizes, from small leaks (? ? 25 mm) up to double ended guillotine breaks, was simulated. The calculation results demonstrate the efficiency of the SIS: a) in case of LOCAs caused by very small breaks (? ? 25 mm) the EPR's SIS is capable - in conjunction with the automatic particle cooldown of the secondary side - to prevent loop draining, even when only two Medium Head Safety Injection (MHSI) trains are effective. In case of small and intermediate leaks (? ? 150 mm) the SIS ensures sufficiently high injection rates for preventing core uncovery, again even when only two MHSIs are effective. For leaks within the range 150 ? ? ? 350 mm, the SIS is able to limit the core uncovery. b) In case of large break LOCAs the SIS ensures a fast reflood of the core within approximately 120 s; the peak cladding temperature is 810 deg. C. Reflood of the core is achieved by the accumulator injection. (authoccumulator injection. (author). 5 refs, 6 figs, 5 tabs

368

The Performance of Polymer Solution Added with Viscosity Stabilizer and the Evaluation of Its Oil Displacement Efficiency in Daqing Oilfield  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aiming at the low viscosity of polymer solution, which is compounded with fresh water but diluted with produced water, and at the problems concerning oil displacement efficiency, an onsite test on polymer solution with viscosity stabilizer (PSVS) is carried out. As a result, it has great and guiding significance to the application and popularization of viscosity stabilizer by studying the performance of polymer solution with viscosity stabilizer and its influence on oil displacement ...

Wei, Jianguang; Zhang, Qingjie; Jiang, Zhenhai; Zhang, Haijun; Ni, Xiangcai; Shao, Hongyan; Wang, Zhonghui

2012-01-01

369

Functional characterization of a water channel of the nematode Caenorhabditis elegans.  

Science.gov (United States)

A genome project for the species Caenorhabditis elegans has demonstrated the presence of eight cDNAs belonging to the major intrinsic protein (MIP) family. We previously characterized one of these cDNAs known as C01G6.1. C01G6.1 was confirmed to be a water channel and newly designated as AQP-CE1 [Am. J. Physiol. 275 (1998) C1459-C1464]. In this paper, we examined the function of another MIP protein encoded by F40F9.9. This cDNA encodes a 274-amino acid protein showing a high sequence identity with mammalian aquaporin-8 (AQP8) water channel (35%) and d-TIP (34%), an AQP of Arabidopsis. The expression of F40F9.9 in Xenopus oocytes increased the osmotic water permeability (P(f)) 10.4-fold, and the activation energy for P(f) from Arrhenius plot was 4.7 kcal/mol, suggesting that F40F9.9 is a water channel (AQP-CE2). AQP-CE2 was not permeable to glycerol or urea. Oocyte P(f) was reversibly inhibited by 58% after an incubation with 0.3 mM HgCl(2). To identify the mercury-sensitive site, four individual cysteine residues in AQP-CE2 (at positions 47, 132, 149, 259) were altered to serine by site-directed mutagenesis. Of these mutants, only C132S had a P(f) similar to that of the wild-type together with an acquired mercury resistance, suggesting that Cys-132 is the mercury-sensitive site. Similar results were obtained by the mutation of Cys-132 to alanine (C132A). Replacement of Cys-132 with tryptophan decreased P(f) by 64%, but P(f) was still 2.5 times higher than that of the control. Cys-132 is located in the transmembrane helix 3, close to the transition to the extracellular loop C. These results suggest that the transmembrane helix 3, including Cys-132, might participate in the aqueous pore formation, or, alternatively, that Cys-132 might contribute to the construction of the AQP protein. PMID:11118622

Kuwahara, M; Asai, T; Sato, K; Shinbo, I; Terada, Y; Marumo, F; Sasaki, S

2000-12-15

370

General displaced SU(1, 1) number states: Revisited  

Energy Technology Data Exchange (ETDEWEB)

The most general displaced number states, based on the bosonic and an irreducible representation of the Lie algebra symmetry of su(1, 1) and associated with the Calogero-Sutherland model are introduced. Here, we utilize the Barut-Girardello displacement operator instead of the Klauder-Perelomov counterpart, to construct new kind of the displaced number states which can be classified in nonlinear coherent states regime, too, with special nonlinearity functions. They depend on two parameters, and can be converted into the well-known Barut-Girardello coherent and number states, respectively, depending on which of the parameters equal to zero. A discussion of the statistical properties of these states is included. Significant are their squeezing properties and anti-bunching effects which can be raised by increasing the energy quantum number. Depending on the particular choice of the parameters of the above scenario, we are able to determine the status of compliance with flexible statistics. Major parts of the issue is spent on something that these states, in fact, should be considered as new kind of photon-added coherent states, too. Which can be reproduced through an iterated action of a creation operator on new nonlinear Barut-Girardello coherent states. Where the latter carry, also, outstanding statistical features.

Dehghani, A., E-mail: alireza.dehghani@gmail.com, E-mail: a-dehghani@tabrizu.ac.ir [Physics Department, Payame Noor University, P.O. Box 19395-3697 Tehran (Iran, Islamic Republic of)

2014-04-15

371

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

372

A displacement spindle in a micro/nano level  

Science.gov (United States)

This paper presents two micro/nano level displacement sensors, which consist of a mini LDGI (linear diffraction grating interferometer) and a focus probe. These two sensors are integrated into the spindle system of a micro/nano-CMM. This micro/nano spindle system is fixed on a rectangular granite bridge to achieve the z-axis function. The motion of the spindle is driven by an ultrasonic motor on a precision cross-roller slide. Its displacement is fed back by the LDGI. A DVD pick-up head is modified with its S-curve principle as the non-contact focus probe. Mounting the probe onto the spindle head, it is possible to achieve a large displacement and nanoresolution measuring spindle system with a feedback nanomotion control scheme. After accuracy calibration and error compensation, the spindle motion to 10 mm can perform 10 nm positioning accuracy and 30 nm measurement accuracy. Experiments on some ultraprecision profiles have shown the capability of this spindle system.

Fan, Kuang-Chao; Lai, Zi-Fa; Wu, Peitsung; Chen, Yung-Chang; Chen, Yejin; Jäger, Gerd

2007-06-01

373

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.

S., Arora; F., Pot& #367; & #269; ek.

2009-06-01

374

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

375

General displaced SU(1, 1) number states: Revisited  

International Nuclear Information System (INIS)

The most general displaced number states, based on the bosonic and an irreducible representation of the Lie algebra symmetry of su(1, 1) and associated with the Calogero-Sutherland model are introduced. Here, we utilize the Barut-Girardello displacement operator instead of the Klauder-Perelomov counterpart, to construct new kind of the displaced number states which can be classified in nonlinear coherent states regime, too, with special nonlinearity functions. They depend on two parameters, and can be converted into the well-known Barut-Girardello coherent and number states, respectively, depending on which of the parameters equal to zero. A discussion of the statistical properties of these states is included. Significant are their squeezing properties and anti-bunching effects which can be raised by increasing the energy quantum number. Depending on the particular choice of the parameters of the above scenario, we are able to determine the status of compliance with flexible statistics. Major parts of the issue is spent on something that these states, in fact, should be considered as new kind of photon-added coherent states, too. Which can be reproduced through an iterated action of a creation operator on new nonlinear Barut-Girardello coherent states. Where the latter carry, also, outstanding statistical features

376

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)

377

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 SciELO Chile | Language: English Abstract in english 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.

378

Tensor distribution function  

Science.gov (United States)

Diffusion weighted MR imaging is a powerful tool that can be employed to study white matter microstructure by examining the 3D displacement profile of water molecules in brain tissue. By applying diffusion-sensitizing gradients along a minimum of 6 directions, second-order tensors (represetnted by 3-by-3 positive definiite matrices) can be computed to model dominant diffusion processes. However, it has been shown that conventional DTI is not sufficient to resolve more complicated white matter configurations, e.g. crossing fiber tracts. More recently, High Angular Resolution Diffusion Imaging (HARDI) seeks to address this issue by employing more than 6 gradient directions. To account for fiber crossing when analyzing HARDI data, several methodologies have been introduced. For example, q-ball imaging was proposed to approximate Orientation Diffusion Function (ODF). Similarly, the PAS method seeks to reslove the angular structure of displacement probability functions using the maximum entropy principle. Alternatively, deconvolution methods extract multiple fiber tracts by computing fiber orientations using a pre-specified single fiber response function. In this study, we introduce Tensor Distribution Function (TDF), a probability function defined on the space of symmetric and positive definite matrices. Using calculus of variations, we solve for the TDF that optimally describes the observed data. Here, fiber crossing is modeled as an ensemble of Gaussian diffusion processes with weights specified by the TDF. Once this optimal TDF is determined, ODF can easily be computed by analytical integration of the resulting displacement probability function. Moreover, principle fiber directions can also be directly derived from the TDF.

Leow, Alex D.; Zhu, Siwei

2008-03-01

379

HELIUM EFFECTS ON DISPLACEMENT CASCADE IN TUNGSTEN  

Energy Technology Data Exchange (ETDEWEB)

Molecular dynamics (MD) simulations were performed to investigate He effects on displacement cascades in W. Helium content, proportion of interstitial and substitutional He and temperature were varied to reveal the various effects. The effect of interstitial He on the number of self-interstitial atoms (SIAs) produced during cascade damage appears to be insignificant. However, interstitial He tends to fill a vacancy (V). Nevertheless, this process is less favorable than SIA-V recombination particularly when excess SIAs are present before a cascade. The efficiency of He filling and SIA-V recombination increases as temperature increases due to increased point defect mobility. Likewise, substitutional He is more susceptible to displacement during a collision cascade than W. This susceptibility increases towards higher temperatures. Consequently, the number of surviving V is governed by the interplay between displaced substitutional He and SIA-V recombination. The temperature dependence of these processes results in a minimum number of V reached at an intermediate temperature.

Setyawan, Wahyu; Nandipati, Giridhar; Roche, Kenneth J.; Heinisch, Howard L.; Kurtz, Richard J.; Wirth, Brian D.

2013-09-30

380

Forced displacement and women's security in Colombia.  

Science.gov (United States)

In the protracted Colombian conflict, assistance to internally displaced persons has developed in the context of contradictory political processes. The Colombian government's launching of a transitional justice process in the midst of armed conflict has generated a complex situation displaying both conflict and post-conflict characteristics. The progressive Constitutional Court rulings on internal displacement, in particular the gender-sensitive Auto 092, constitute an attempt to bring together humanitarian interventions and transitional justice measures in a rights-based framework. However, the national government is reluctant to adopt them fully and local realities still hamper their integrated implementation. Displaced women, therefore, remain in an especially vulnerable position. This paper argues that gender-sensitive humanitarian interventions must take into account all of these complexities of scale and political process in order to make legal frameworks more effective at the local level. In these contexts, interventions should pay particular attention to strategies that contribute to transforming pre-existing gender regimes. PMID:20132270

Meertens, Donny

2010-04-01

 
 
 
 
381

The influence of temperature and density functional models in ab initio molecular dynamics simulation of liquid water  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The performance of density functional theory methods for the modeling of condensed aqueous systems is hard to predict and validation by ab initio molecular simulation of liquid water is absolutely necessary. In order to assess the reliability of these tests, the effect of temperature on the structure and dynamics of liquid water has been characterized with 16 simulations of 20 ps in the temperature range of 280-380 K. We find a pronounced influence of temperature on the pair correlation funct...

Vandevondele, J.; Mohamed, F.; Krack, M.; Hutter, J.; Sprik, M.; Parrinello, M.

2005-01-01

382

Towards an assessment of the accuracy of density functional theory for first principles simulations of water II  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A series of 20 ps ab initio molecular dynamic simulations of water at ambient density and temperatures ranging from 300 to 450K are presented. Both Car-Parrinello (CP) and Born-Oppenheimer (BO) molecular dynamics techniques are compared for systems containing 54 and 64 water molecules. At 300K, excellent agreement is found between radial distribution functions (RDFs) obtained with BO and CP dynamics, provided an appropriately small value of the fictitious mass parameter is u...

Schwegler, E.; Grossman, G. C.; Gygi, F.; Galli, G.

2004-01-01

383

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

384

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

385

A density-functional theory-based neural network potential for water clusters including van der Waals corrections.  

Science.gov (United States)

The fundamental importance of water for many chemical processes has motivated the development of countless efficient but approximate water potentials for large-scale molecular dynamics simulations, from simple empirical force fields to very sophisticated flexible water models. Accurate and generally applicable water potentials should fulfill a number of requirements. They should have a quality close to quantum chemical methods, they should explicitly depend on all degrees of freedom including all relevant many-body interactions, and they should be able to describe molecular dissociation and recombination. In this work, we present a high-dimensional neural network (NN) potential for water clusters based on density-functional theory (DFT) calculations, which is constructed using clusters containing up to 10 monomers and is in principle able to meet all these requirements. We investigate the reliability of specific parametrizations employing two frequently used generalized gradient approximation (GGA) exchange-correlation functionals, PBE and RPBE, as reference methods. We find that the binding energy errors of the NN potentials with respect to DFT are significantly lower than the typical uncertainties of DFT calculations arising from the choice of the exchange-correlation functional. Further, we examine the role of van der Waals interactions, which are not properly described by GGA functionals. Specifically, we incorporate the D3 scheme suggested by Grimme (J. Chem. Phys. 2010, 132, 154104) in our potentials and demonstrate that it can be applied to GGA-based NN potentials in the same way as to DFT calculations without modification. Our results show that the description of small water clusters provided by the RPBE functional is significantly improved if van der Waals interactions are included, while in case of the PBE functional, which is well-known to yield stronger binding than RPBE, van der Waals corrections lead to overestimated binding energies. PMID:23557541

Morawietz, Tobias; Behler, Jörg

2013-08-15

386

Displacement energy of unit disk cotangent bundles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We give an upper bound of a Hamiltonian displacement energy of a unit disk cotangent bundle $D^*M$ in a cotangent bundle $T^*M$, when the base manifold $M$ is an open Riemannian manifold. Our main result is that the displacement energy is not greater than $C r(M)$, where $r(M)$ is the inner radius of $M$, and $C$ is a dimensional constant. As an immediate application, we study symplectic embedding problems of unit disk cotangent bundles. Moreover, combined with results in sy...

Irie, Kei

2011-01-01

387

DNA fork displacement rates in human cells  

International Nuclear Information System (INIS)

DNA fork displacement rates were measured in 20 human cell lines by a bromodeoxyuridine-313 nm photolysis technique. Cell lines included representatives of normal diploid, Fanconi's anemia, ataxia telangiectasia, xeroderma pigmentosum, trisomy-21 and several transformed lines. The average value for all the cell lines was 0.53 +- 0.08 ?m/min. The average value for individual cell lines, however, displayed a 30% variation. Less than 10% of variation in the fork displacement rate appears to be due to the experimental technique; the remainder is probably due to true variation among the cell types and to culture conditions. (Auth.)

388

The tensor distribution function.  

Science.gov (United States)

Diffusion weighted magnetic resonance imaging is a powerful tool that can be employed to study white matter microstructure by examining the 3D displacement profile of water molecules in brain tissue. By applying diffusion-sensitized gradients along a minimum of six directions, second-order tensors (represented by three-by-three positive definite matrices) can be computed to model dominant diffusion processes. However, conventional DTI is not sufficient to resolve more complicated white matter configurations, e.g., crossing fiber tracts. Recently, a number of high-angular resolution schemes with more than six gradient directions have been employed to address this issue. In this article, we introduce the tensor distribution function (TDF), a probability function defined on the space of symmetric positive definite matrices. Using the calculus of variations, we solve the TDF that optimally describes the observed data. Here, fiber crossing is modeled as an ensemble of Gaussian diffusion processes with weights specified by the TDF. Once this optimal TDF is determined, the orientation distribution function (ODF) can easily be computed by analytic integration of the resulting displacement probability function. Moreover, a tensor orientation distribution function (TOD) may also be derived from the TDF, allowing for the estimation of principal fiber directions and their corresponding eigenvalues. PMID:19097208

Leow, A D; Zhu, S; Zhan, L; McMahon, K; de Zubicaray, G I; Meredith, M; Wright, M J; Toga, A W; Thompson, P M

2009-01-01

389

Interaction of ComO- (m = 1-3) with water: Anion photoelectron spectroscopy and density functional calculations  

Science.gov (United States)

We investigated the reactions between cobalt-oxides and water molecules using photoelectron spectroscopy and density functional calculations. It has been confirmed by both experimental observation and theoretical calculations that dihydroxide anions, Com(OH)2- (m = 1-3), were formed when ComO- clusters interact with the first water molecule. Addition of more water molecules produced solvated dihydroxide anions, Com(OH)2(H2O)n- (m = 1-3). Hydrated dihydroxide anions, Com(OH)2(H2O)n-, are more stable than their corresponding hydrated metal-oxide anions, ComO(H2O)n+1-.

Li, Ren-Zhong; Xu, Hong-Guang; Cao, Guo-Jin; Zhao, Yu-Chao; Zheng, Wei-Jun

2011-10-01

390

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

391

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

International Nuclear Information System (INIS)

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

392

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