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1

The estimation of oil water displacement functions  

Scientific Electronic Library Online (English)

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

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

2007-09-01

2

Water displacement mercury pump  

Science.gov (United States)

A water displacement mercury pump has a fluid inlet conduit and diffuser, a valve, a pressure cannister, and a fluid outlet conduit. The valve has a valve head which seats in an opening in the cannister. The entire assembly is readily insertable into a process vessel which produces mercury as a product. As the mercury settles, it flows into the opening in the cannister displacing lighter material. When the valve is in a closed position, the pressure cannister is sealed except for the fluid inlet conduit and the fluid outlet conduit. Introduction of a lighter fluid into the cannister will act to displace a heavier fluid from the cannister via the fluid outlet conduit. The entire pump assembly penetrates only a top wall of the process vessel, and not the sides or the bottom wall of the process vessel. This insures a leak-proof environment and is especially suitable for processing of hazardous materials.

Nielsen, Marshall G. (Woodside, CA)

1985-01-01

3

Displacement functions for diatomic materials  

Energy Technology Data Exchange (ETDEWEB)

An extension of the methods of Lindhard et at. was used to calculate the total displacement function n/sub ij/(E) for a number of diatomic materials, where n/sub ij/(E) is defined to be the average number of atoms of type j which are displaced from their sites in a displacement cascade initiated by a PKA of type i and energy E. From the n/sub ij/(E) one can calculate the fraction n/sub ij/(E) of the displacements produced by a type i PKA with energy E which are of type j. Values of the n/sub ij/ for MgO, CaO, Al/sub 2/O/sub 3/, and TaO are presented. It is shown that for diatomic materials with mass ratios reasonably near one (e.g., MgO, Al/sub 2/O/sub 3/) and equal displacement thresholds for the two species the n/sub ij/ become independent of the PKA type i at energies only a few times threshold. However, for larger mass ratios the n/sub ij/ do not become independent of i until much larger, energies are reached - e.g. > 10/sup 5/ eV for TaO. In addition, it is found that the n/sub ij/ depend sensitively on the displacement thresholds, with very dramatic charges occuring when the two thresholds become significantly different from one another.

Panrkin, D.M.; Coulter, C.A.

1979-01-29

4

Experimental Study of Heavy Oil Displacement by Hot Water in Porous Media  

Science.gov (United States)

The injection of one fluid to displace another in a porous medium is the basis of many industrial processes such as Enhanced Oil Recovery (EOR). EOR applications are encouraged by high oil prices and growing oil demand. Therefore, performance prediction of EOR processes is of great importance to their success. Core flooding experiments are well known practices in the petroleum industry that provide economical means of determining the responses of reservoir rock and fluids to the driving mechanism responsible for production. Lab experiments provide both insight into the behavior of fluid displacements and data with which to test and calibrate numerical simulators. In this study, laboratory experiments were conducted in order to test the effectiveness of hot water injection to displace heavy oil from a given porous medium. The objective was to find the optimum design parameters in terms of injection temperature and hot water slug size that will yield the best performance. Analysis of these experiments has revealed the functional relationships between the scaling groups describing the displacement and the oil recovery obtained from such displacement. Results obtained from several design configurations are presented. These relationships can be used as a tool for the design of hot water injection to recover heavy oil. They also provide conditions under which a given design may yield better recovery performance.

Alajmi, Abdullah; Gharbi, Ridha; Algharaib, Meshal

2008-11-01

5

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.

2013-11-01

6

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

7

Neuronal activity significantly reduces water displacement: DWI of a vital rat spinal cord with no hemodynamic effect.  

Science.gov (United States)

Changes in the diffusion weighted MRI (DWI) signal were observed to be correlated with neuronal activity during chemically induced brain activity, epileptic seizures, or visual stimulation. These changes suggest a possible reduction in water displacement that accompanies neuronal activity, but were possibly affected by other physiological mechanisms such as blood oxygenation level and blood flow. We developed an imaging experiment of an excised and vital newborn rat spinal cord to examine the effect of neuronal function on the displacement of water molecules as measured by DWI signal. This approach provides a DWI experiment of a vital mammalian CNS tissue in the absence of some of the systemic sources of noise. We detected a significant and reproducible drop with an average value of 19.5 ± 1.6% (mean ± SE) upon activation. The drop repeated itself in three orthogonal directions. ADC values corresponded to an oblate anisotropy. This result was validated by high resolution DWI of a fixed tissue, imaged with an ultra-high field MRI. The results support our working hypothesis that water displacement is affected by neuronal activation. These results further imply that water displacement might serve as a potential marker for brain function, and that, although commonly viewed as wholly electrochemical, neuronal activity includes a significant mechanical dimension that affects water displacement. PMID:23507391

Tirosh, Nitzan; Nevo, Uri

2013-08-01

8

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

9

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%

10

Neuropsychological functioning in posttraumatic stress disorder following forced displacement in older adults and their offspring.  

Science.gov (United States)

The aim of the present study was to investigate neuropsychological performance in an untried trauma sample of older adults displaced during childhood at the end of World War II (WWII) with and without posttraumatic stress disorder (PTSD) as well as transgenerational effects of trauma and PTSD on their offspring. Displaced older adults with (n=20) and without PTSD (n=24) and nondisplaced healthy individuals (n=11) as well as one of their respective offspring were assessed with a large battery of cognitive tests (primarily targeting memory functioning). No evidence for deficits in neuropsychological performance was found in the aging group of displaced people with PTSD. Moreover, no group difference emerged in the offspring groups. Findings may be interpreted as first evidence for a rather resilient PTSD group of older adults that is available for assessment 60 years after displacement. PMID:23896354

Jelinek, Lena; Wittekind, Charlotte E; Moritz, Steffen; Kellner, Michael; Muhtz, Christoph

2013-12-15

11

Formation of intercalation compound of kaolinite-glycine via displacing guest water by glycine.  

Science.gov (United States)

The kaolinite-glycine intercalation compound was successfully formed by displacing intercalated guest water molecules in kaolinite hydrate as a precursor. The microstructure of the compound was characterized by X-ray diffraction, Fourier Transform Infrared Spectroscopy and Scanning Electron Microscope. Results show that glycine can only be intercalated into hydrated kaolinite to form glycine-kaolinite by utilizing water molecules as a transition phase. The intercalated glycine molecules were squeezed partially into the ditrigonal holes in the silicate layer, resulting in the interlayer distance of kaolinite reaching 1.03nm. The proper intercalation temperature range was between 20°C and 80°C. An intercalation time of 24h or above was necessary to ensure the complete formation of kaolinite-glycine. The highest intercalation degree of about 84% appeared when the system was reacted at the temperature of 80°C for 48h. There were two activation energies for the intercalation of glycine into kaolinite, one being 21kJ/mol within the temperature range of 20-65°C and the other 5.8kJ/mol between 65°C and 80°C. The intercalation degree (N) and intercalation velocity (v) of as a function of intercalation time (t) can be empirically expressed as N=-79.35e(-)(t)(/14.8)+80.1 and v=5.37e(-)(t)(/14.8), respectively. PMID:25086722

Zheng, Wan; Zhou, Jing; Zhang, Zhenqian; Chen, Likun; Zhang, Zhongfei; Li, Yong; Ma, Ning; Du, Piyi

2014-10-15

12

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

13

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)

14

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

15

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

Science.gov (United States)

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) Å-1 whereas they are different in the high Q domain (1.7÷4) Å-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.

Benedetto, A.; Magazù, S.; Migliardo, F.; Mondelli, C.; Gonzalez, M. A.

2012-02-01

16

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.

17

Three-dimensional point spread function characterization of a radially displaced scatterer  

Science.gov (United States)

For synthetic aperture radar (SAR) systems utilizing a circular aperture for target recognition, it is important to know how a target's point spread function (PSF) behaves as a function of various radar functional parameters and target positional changes that may occur during data collection. The purpose of this research is characterizing the three dimensional (3D) point spread function (3D PSF) behavior of a radially displaced point scatterer for circular synthetic aperture radar (CSAR). For an automatic target recognition (ATR) systems requiring target identification with a high degree of confidence, CSAR processing represents a viable alternative given it can produce images with resolution less than a wavelength. With very large CSAR apertures (90°r or more) three dimensional imaging is possible with a single phase center and a single pass. Using a backprojection image formation process, point target PSF responses are generated at various target locations at a given radar bandwidth, depression angle and full 360°r CSAR apertures. Consistent with previous studies, the 3D PSF for a point target located at the image center is cone shaped and serves as the basis for comparing and characterizing the 3D PSFs for radially displaced scatterers. For radially displaced point target, simulated results show 3D PSF response is asymmetric and tends to become an elliptic shape.

Majumder, Uttam K.; Temple, Michael A.; Minardi, Michael J.; Zelnio, Edmund G.

2007-04-01

18

Constant load and constant displacement stress corrosion in simulated water reactor environments  

International Nuclear Information System (INIS)

The stress corrosion behaviour of selected water reactor constructional materials, as determined by constant load or constant displacement test techniques, is reviewed. Experimental results obtained using a very wide range of conditions have been collected in a form for easy reference. A discussion is given of some apparent trends in these data. The possible reasons for these trends are considered together with a discussion of how the observed discrepancies may be resolved. (author)

19

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

Directory of Open Access Journals (Sweden)

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

Larter Steve R

2001-08-01

20

Frontal densification and displacement: A scenario of North Pacific Intermediate Water formation  

Science.gov (United States)

The formation of North Pacific Intermediate Water (NPIW) requires a densification of ˜0.2-0.3 ? ? through interior transformation processes. Evidence of this density anomaly is discovered on neutral density surfaces in the subarctic-tropical frontal zone (SATFZ) showing an eastward tongue of positive density anomaly coincident with a cabbeling maximum tongue. The northward displacement of the SATFZ with depth east of dateline enables the transformed dense water from overlying thermocline to sink into the northeast subtropical NPIW domain. The further southward and southwestward spreading across the subtropical gyre yields the observed distribution of NPIW.

You, Yuzhu

2010-07-01

 
 
 
 
21

Corrections to the displacement estimation based on analytic minimization of adaptive regularized cost functions for ultrasound elastography.  

Science.gov (United States)

Ultrasound elastography has been widely applied in clinical diagnosis. To produce high-quality elastograms, displacement estimation is important to generate ne displacement map from the original ratio-frequency signals. Traditional displacement estimation methods are based on the local information of signals pair, such as cross-correlation method, phase zero estimation. However, the tissue movement is nonlocal during realistic elasticity process due to the compression coming from the surface. Recently, regularized cost functions have been broadly used in ultrasound elastography. In this paper, we tested the using of analytic minimization of adaptive regularized cost function, a combination of different regularized cost functions, to correct the displacement estimation calculated by cross-correlation method directly or by lateral displacement guidance. We have demonstrated that the proposed method exhibit obvious advantages in terms of imaging quality with higher levels of elastographic signal-to-noise ratio and elastographic contrast-to-noise ratio in the simulation and phantom experiments respectively. PMID:25226985

Peng, Bo; Lai, Junliang; Wang, Ling; Liu, Dong C

2014-01-01

22

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

23

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

Directory of Open Access Journals (Sweden)

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

P NAYAK,

2011-04-01

24

33 CFR 150.445 - When is oil in a single point mooring-oil transfer system (SPM-OTS) displaced with water?  

Science.gov (United States)

...single point mooring-oil transfer system (SPM-OTS) displaced with water? 150.445...single point mooring-oil transfer system (SPM-OTS) displaced with water? (a) The oil in an SPM-OTS must be displaced with water, and...

2010-07-01

25

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

Science.gov (United States)

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. PMID:18180088

Wahla, Intkhab Hazoor; Kirkham, M B

2008-09-01

26

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

27

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.)

28

An image displacement correction algorithm for functional MRI using phase differences in k-space  

International Nuclear Information System (INIS)

In functional MRI (fMRI) examinations using Echo-planar Imaging (EPI) sequences, brain displacement in the reconstructed images occurs due to physiological motion artifacts and static magnetic field drift. We have developed a new reordering technique to correct for such displacement. This reordering technique is based on the principle that the displacement can be reduced when using an EPI sequence by removing first-order phase shift along the k-space axes; that is, by using a phase-mapping technique. We applied the reordering technique to an fMRI data set to confirm its effectiveness. The fMRI data set was acquired with a 1.5-T MRI system (MRH1500AD, Hitachi Medial Corporation) using a multislice interleaved EPI sequence (4 slices, 8 shots per slice, FOV=240 x 240 mm, slice thickness=6 mm, matrix size=128 x 128, TR/TE=1250/10 ms, FA=60deg). We used the first image of each slice as the reference image. The inclination angles along the k-space axes were calculated with the least-squares method. The signal-to-noise ratio will affect the precision of the inclination angles, so we tried to optimize the data-selection parameters by varying the number of data points from the origin in k-space (±10 to 30 points), and by varying the threshold value (1% to 5% of the signal intensity of the origin in k-space). After correcting for displacement, we made error images of each imaging plane to estimate the accuracy of the selection methods. All error images before the correction haAll error images before the correction had high error value regions. We compared the error values in the regions for various parameter values and found that setting the threshold value at 1% could achieve the most accurate correction. We conclude that this reordering technique using phase maps can be used to accurately correct an fMRI data set taken from an EPI sequence. (author)

29

Non-surgical functional treatment for displaced olecranon fractures in the elderly.  

Science.gov (United States)

We retrospectively evaluated the clinical and radiological outcomes of a consecutive cohort of patients aged > 70 years with a displaced fracture of the olecranon, which was treated non-operatively with early mobilisation. We identified 28 such patients (27 women) with a mean age of 82 years (71 to 91). The elbow was initially immobilised in an above elbow cast in 90° of flexion of the elbow for a mean of five days. The cast was then replaced by a sling. Active mobilisation was encouraged as tolerated. No formal rehabilitation was undertaken. At a mean follow-up of 16 months (12 to 26), the mean ranges of flexion and extension were 140° and 15° respectively. On a visual analogue scale of 1 (no pain) to 10, the mean pain score was 1 (0 to 8). Of the original 28 patients 22 developed nonunion, but no patients required surgical treatment. We conclude that non-operative functional treatment of displaced olecranon fractures in the elderly gives good results and a high rate of satisfaction. PMID:24692623

Gallucci, G L; Piuzzi, N S; Slullitel, P A I; Boretto, J G; Alfie, V A; Donndorff, A; De Carli, P

2014-04-01

30

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

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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

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

International Nuclear Information System (INIS)

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

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Molecular organization of phospholipid monolayers on the water surface by Maxwell displacement current measurement  

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The monolayer of organic molecules at the air-water interface has been studied using the Maxwell displacement current (MDC) technique. The materials used in this study were the biological materials of phosphatidyl ethanolamine (PE) and phosphatidic acids (PA). The configuration of the experimental set-up consists of the metal/air-gap/monolayer/metal coupled with the Langmuir method. This measurement enables the detection of current without destroying the monolayer. The phase transition and molecular orientation of the phospholipid monolayers were investigated using MDC measurement without mechanical contact between electrodes and the materials. Direct evidence of phase transition from gaseous to the polar ordering phase can be obtained across phospholipid monolayers even though at very low surface pressure. Relaxation process of the phospholipid monolayers was investigated by using the step compression on the MDC signals.

Sulaiman, Khaulah; Majid, Wan Haliza Abdul; Muhamad, Muhamad Rasat

2006-02-01

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Interpretation of tracer displacement during infiltration of river water to ground water  

International Nuclear Information System (INIS)

The accidental release of a tritium pulse of about 500 Ci into a river in northern Switzerland allowed the measurement of travel times at a site where the river recharges a granular aquifer almost perpendicularly to the ground water flow. A series of sampling wells had been previously installed in the aquifer. Most wells give access to shallow freshly infiltrated water. The infiltrated water flows along in the top layer of the aquifer, thus allowing for a one-dimensional analysis of the spreading process from the river to the ground water in the wells. The linear ground water flow velocities calculated from the tritium responses at distances from the river of up to 500 m confirm the velocities determined from an earlier local-scale uranine experiment at the same site. The scarce data used to describe tracer transport in the aquifer allowed for an assessment of dispersivity with the method of moments. A linearly scale-dependent dispersivity is evaluated from the mode of increase of the temporal variance of the tracer concentration distribution. Some wells revealed bimodal responses; here the method of moments is applied in combination with a two-layer model

34

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

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Effect of water storage on tooth displacement in maxillary complete dentures  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Este estudo avaliou a movimentação dental sob influência da imersão em água ocorrida na armazenagem da prótese à temperatura de 37ºC. Foram confeccionadas 10 próteses totais superiores com resina acrílica Clássico pelo método convencional de prensagem em muflas metálicas. Pontos referenciais metálic [...] os foram colocados nos dentes incisivos centrais (I), pré-molares (PM) e molares (M). Doze horas após a prensagem final, a resina acrílica foi polimerizada em água aquecida a 74ºC por 9 h. As muflas foram removidas da unidade polimerizadora após esfriamento da água e as próteses foram desincluídas, acabadas e armazenadas em água à temperatura de 37ºC pelos períodos de 1 semana, 1 mês e 3 meses. A movimentação dos dentes foi verificada nas distâncias transversais I-I, PM-PM e M-M e ântero-posteriores IE-ME e ID-MD após demuflagem e nos intervalos de armazenagem em água, com microscópio comparador óptico com precisão de 0,0005 mm. Os resultados foram submetidos à análise de variância e ao teste de Tukey (5%). Comparando-se os períodos de avaliação para cada ponto de referência transversal e ântero-posterior, não houve diferença estatisticamente significante (p>0.05) entre os valores pós-demuflagem e após os intervalos de armazenamento em água para as distâncias I-I, PM-PM, M-M e RI-RM. Para o ponto LI-LM, entretanto, os valores de demuflagem foram estatisticamente diferentes daqueles observados após estocagem em água por 1 semana, 1 mês e 3 meses (p0.05). Esses resultados confirmam a complexidade da movimentação dos dentes em próteses totais. Do ponto de vista clínico, a diferença observada para a distância LI-LM após a armazenagem em água não seria percebida pelos pacientes durante o uso clínico. Abstract in english The purpose of this study was to investigate the effect of water storage at 37ºC (1 week, 1 month and 3 months) on tooth displacement in maxillary complete dentures. Ten maxillary dentures were constructed with Clássico acrylic resin using the conventional method of packing in metallic flasks. Metal [...] lic reference pins were placed in the incisal border of the central incisors (I), labial cusp of the first premolars (PM), and mesiolabial cusp of the second molars (M). Twelve hours after final flask closure, the acrylic resin was cured in water at 74ºC for 9 h. The flasks were removed from the thermo-polymerizing unit after water-cooling and the dentures were deflasked, finished and stored in water at a temperature of 37ºC for 1 week, 1 month and 3 months. At deflasking and at the water storage intervals, the I-I (incisor to incisor), PM-PM (pre-molar to pre-molar), and M-M (molar to molar) transversal distances, and LI-LM (left incisor to left molar) and RI-RM (right incisor to right molar) anteroposterior distances were measured using an optical microscope with 0.0005 mm accuracy. Data were submitted to ANOVA and Tukey´s test (5%). Comparing the evaluation periods for each individual transversal and anteroposterior reference point, no statistically significant differences were observed among deflasking and the water storage intervals for I-I, PM-PM, M-M and RI-RM distances (p>0.05). For LI-LM, however, deflasking values were statistically different from those of 1-week, 1-month and 3-month water storage intervals (p0.05). These results confirm the complexity of tooth displacement in complete dentures. From a clinical standpoint, the difference observed in LI-LM distance after water storage would not be detected by the patients during clinical use.

Rafael Leonardo Xediek, Consani; Marcelo Ferraz, Mesquita; Simonides, Consani; Lourenço, Correr Sobrinho; Manoel Damião, Sousa-Neto.

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

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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

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

Science.gov (United States)

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

Seo, Kyung Won; Lee, Sang Joon

2014-06-30

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

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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

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

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

Sebastião do Amaral Machado , ,, ,

2006-09-01

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The four-year functional result after a displaced subcapital hip fracture treated with three different surgical options  

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According to the literature, hip function after hip fracture is affected by the type of surgery. Our aim was to determine the correlation between surgical treatment of hip fracture and postoperative function in the elderly. Inclusion criteria were displaced hip fracture and age over 70 years. One hundred and twenty-nine participants were randomly divided into three groups according to the type of the surgical operation they underwent (hemi-arthroplasty [Merete, Berlin, Germany], total arthro...

Mouzopoulos, George; Stamatakos, Michalis; Arabatzi, Helen; Vasiliadis, George; Batanis, George; Tsembeli, Anastasia; Tzurbakis, Mathaios; Safioleas, Michalis

2008-01-01

 
 
 
 
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Near-Infrared Studies of Glucose and Sucrose in Aqueous Solutions: Water Displacement Effect and Red Shift in Water Absorption from Water-Solute Interaction  

Science.gov (United States)

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 the concentration up to our highest concentration. We also performed the same measurements and analysis with sucrose instead of glucose as solute and compare.

Jung, Youngeui; Hwang, Jungseek

2013-02-01

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

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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

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-01-01

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Experimental study of the influence of certain parameters characteristic of heterogeneous formations, on the displacement of oil by water  

Energy Technology Data Exchange (ETDEWEB)

The displacement of oil by water was studied in models with various types of permeability variations. The permeability variations were in a checkered ''Dalmatian'' pattern. The effect of the following factors on oil recovery was determined: ratio of sand permeabilities, ratio of length to height in the high-permeability streaks, and the ratio of high-permeability area to the low-permeability area. Results of all floods are shown in 6 graphs and 7 photographs. It is concluded that the displacement of immiscible liquids in a heterogeneous medium is greatly influenced by the permeability ratio of various sand sections and the ratio of high-permeability area to low-permeability area. The shape of permeability variations is of less importance. (10 refs.)

Martyntsiv, O.F.

1965-11-01

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

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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

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

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A series of molecular dynamics simulations have been performed on organic–water mixtures near mineral surfaces. These simulations show that, in contrast to apolar compounds, small polar organic compounds such as phenols can penetrate through thin water films to adsorb on these mineral surfaces. Furthermore, additional simulations involving demixing of an organic–water mixture near a surfactant-covered mineral surface demonstrate that even low concentrations of adsorbed polar compo...

Larter Steve R; Ct, Duin Adri

2001-01-01

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

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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

49

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

International Nuclear Information System (INIS)

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

50

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

Science.gov (United States)

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

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

2014-03-14

51

Development of extensometer system for measuring displacement of gauge length of low cycle fatigue specimen in high temperature and high pressure water  

International Nuclear Information System (INIS)

Low cycle fatigue experiment in high temperature and high pressure water have been conducted to evaluate environmental fatigue characteristics of nuclear materials which are used in the primary water. The experimental methods of evaluating low cycle fatigue properties are to control by either load or displacement. The study is about the development of extensometer system for measuring displacement in gauge length of low cycle fatigue specimen in autoclave which simulated high temperature and high pressure water. The developed extensometer system showed precise change of displacement data by controlling actuator in room temperature as well as high temperature and high pressure water. This device can be applied to various material testings in high temperature and high pressure environments and is expected to greatly contribute on acquiring more detailed test data.

52

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

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Effect of pore geometry and interfacial tension on water-oil displacement efficiency in oil-wet microfluidic porous media analogs  

Science.gov (United States)

Using oil-wet polydimethylsiloxane (PDMS) microfluidic porous media analogs, we studied the effect of pore geometry and interfacial tension on water-oil displacement efficiency driven by a constant pressure gradient. This situation is relevant to the drainage of oil from a bypassed oil-wet zone during water flooding in a heterogeneous formation. The porosity and permeability of analogs are 0.19 and 0.133-0.268 × 10-12 m2, respectively; each analog is 30 mm in length and 3 mm in width, with the longer dimension aligned with the flow direction. The pore geometries include three random networks based on Voronoi diagrams and eight periodic networks of triangles, squares, diamonds, and hexagons. We found that among random networks both pore width distribution and vugs (large cavities) decreased the displacement efficiency, among the periodic networks the displacement efficiency decreased with increasing coordination number, and the random network with uniform microfluidic channel width was similar to the hexagon network in the displacement efficiency. When vugs were present, displacement was controlled by the sequence of vug-filling and the structure of inter-vug texture was less relevant. Surfactant (0.5 wt. % ethoxylated alcohol) increased the displacement efficiency in all geometries by increasing the capillary number and suppressing the capillary instability.

Xu, Wei; Ok, Jeong Tae; Xiao, Feng; Neeves, Keith B.; Yin, Xiaolong

2014-09-01

54

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

Science.gov (United States)

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

2011-01-01

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

DEFF Research Database (Denmark)

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

Bove, Jeppe; Viberg, Bjarke

56

Deuterium and oxygen-18 isotope effects on nucleophilic displacement by monomeric water in aprotic solvents  

International Nuclear Information System (INIS)

The H2O/D2O rate-constant ratio for nucleophilic attack by water at a methyl carbon (eq 1) is reduced to very near unity when the water is a dilute solute in L2O+CH3X?L2O+CH3+X- a dipolar aprotic solvent. This effect was observed for three leaving groups [CH3X equals 1-methylthiophenium ion (MeTh+), methyl perchlorate (MeOCl3), and methyl trifluoromethanesulfonate (MeOTf)] and for two aprotic solvents acetonitrile (MeCn), and tetrahydrothiophene 1,1-dioxide (TMSO:'';sulfolane). It was also observed that the corresponding H216O/H218O rate-constant ratio is 1.002 +- 0.004 (95% confidence limits) for the reaction of MeTh+ with dilute H2O in TMSO2 at 350C. Although alternative explanations exist (vide infra), these observations are consistent with a mechanism in which no significant positive charge is present on the L2O oxygen in the rate-determining transition state and thus in which the rate-determining process does not involve (and is not preceded by) any significant covalent-bonding interaction between the nucleophile and the methyl carbon. All reactions were followed by uv spectroscopy in a Cary 16K spectrophotometer

57

Tests of Dielectric Model Descriptions of Chemical Charge Displacements in Water  

CERN Document Server

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

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

1994-01-01

58

Displacement transducer  

International Nuclear Information System (INIS)

A displacement transducer comprises a pot magnet having an annular pole and a central pole to sense the displacement of a magnetic material target, the central pole being secured at its end which lies at the mouth of the magnet and being free at its other end. Preferably a stainless steel closure body of annular cup form is braced both to the annular pole and central pole. Mineral insulated cable primary and secondary coils are sealed in the pot magnet. (author)

59

Functional water molecules in rhodopsin activation.  

Science.gov (United States)

G-protein-coupled receptors (GPCRs) are integral membrane proteins that mediate cellular response to an extensive variety of extracellular stimuli. Studies of rhodopsin, a prototype GPCR, have suggested that water plays an important role in mediating the activation of family A GPCRs. However, our understanding of the function of water molecules in the GPCR activation is still rather limited because resolving the functional water molecules solely based on the results from existing experiments is challenging. Using all-atom molecular dynamics simulations in combination with inhomogeneous fluid theory, we identify in this work the positioning of functional water molecules in the inactive state, the Meta II state, and the constitutive active state of rhodopsin, basing on the thermodynamic signatures of the water molecules. We find that one hydration site likely functions as a switch to regulate the distance between Glu181 and the Schiff base in the rhodopsin activation. We observe that water molecules adjacent to the "NpxxY" motif are not as stable in the Meta II state as in the inactive state as indicated by the thermodynamics signatures, and we rationalize that the behaviors of these water molecules are closely correlated with the rearrangement of the water-mediated hydrogen-bond network in the "NPxxY" motif, which is essential for mediating the activation of the receptor. We thereby propose a hypothesis of the water-mediated rhodopsin activation pathway. PMID:25166739

Sun, Xianqiang; Agren, Hans; Tu, Yaoquan

2014-09-18

60

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

 
 
 
 
61

Effect of viscosity of the liquids, saturating the porous medium, on the displacement of oil by water from heterogeneous reservoirs with different thickness ratios of stratified layers  

Energy Technology Data Exchange (ETDEWEB)

A series of waterfloods was performed in a rectangular sand-packed model (690 mm x 120 mm x 48 mm) consisting of 2 stratified layers. The ratio of the stratified layer thicknesses was varied from 0.5 to 5, while the viscosity ratio of oil to water was varied from 1 to 22. It was found that for all ratios of stratified layer thicknesses, both total oil recovery and oil recovery at water breakthrough decreased, as the ratio of oil-to-water viscosity increased. From photographic records of the displacement process, it was shown that as the oil-to-water viscosity ratio increased, stability and uniformity of the displacement front decreased.

Asadov, A.I.; Babalyan, G.A.; Safarov, I.A.; Tairov, N.D.

1964-01-01

62

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

63

The 'wet mind': water and functional neuroimaging  

International Nuclear Information System (INIS)

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

64

Combined Effects of Mass and Velocity on Forward Displacement and Phenomenological Ratings: A Functional Measurement Approach to the Momentum Metaphor  

Science.gov (United States)

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…

De Sa Teixeira, Nuno; Oliveira, Armando Monica; Amorim, Michel-Ange

2010-01-01

65

Assessment of HAM and PEM to Find Analytical Solution for Calculating Displacement Functions of Geometrically Nonlinear Prestressed Cable Structures with Concentrated Mass  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study, two powerful analytical methods, called He’s Parameter-Expanding Methods (PEM) and Homotopy Analysis Method (HAM) are used to calculating displacement functions of geometrically nonlinear prestressed cable structures. In this study, the results of two methods are compared and it is shown that one term in series expansions is sufficient to obtain a solution by using the PEM. Comparison of the obtained solutions with those obtained using numerical method shows that two methods ...

Ghasempour, M.; Rokni, E.; Kimiaeifar, A.; Rahimpour, M.

2009-01-01

66

Displaced Supersymmetry  

CERN Document Server

The apparent absence of light superpartners at the LHC strongly constrains the viability of the MSSM as a solution to the hierarchy problem. These constraints can be significantly alleviated by R-parity violation (RPV). Bilinear R-parity violation, with the single operator L H_u, does not require any special flavor structure and can be naturally embedded in a GUT while avoiding constraints from proton decay (unlike baryon-number-violating RPV). The LSP in this scenario can be naturally long-lived, giving rise to displaced vertices. Many collider searches, particularly those selecting b-jets or leptons, are insensitive to events with such detector-scale displaced decays owing to cuts on track quality and impact parameter. We demonstrate that for decay lengths in the window ~1-1000 mm, constraints on superpartner masses can be as low as ~450 GeV for squarks and ~40 GeV for LSPs. In some parts of parameter space light LSPs can dominate the Higgs decay width, hiding the Higgs from existing searches. This framewor...

Graham, Peter W; Rajendran, Surjeet; Saraswat, Prashant

2012-01-01

67

Displacement cascades in diatomic materials  

International Nuclear Information System (INIS)

A new function, the specified-projectile displacement function p/sub ijk/ (E), is introduced to describe displacement cascades in polyatomic materials. This function describes the specific collision events that produce displacements and hence adds new information not previously available. Calculations of p/sub ijk/ (E) for MgO, Al2O3 and TaO are presented and discussed. Results show that the parameters that have the largest effect on displacement collision events are the PKA energy and the mass ratio of the atom types in the material. It is further shown that the microscopic nature of the displacement events changes over the entire recoil energy range relevant to fusion neutron spectra and that these changes are different in materials whose mass ratio is near one than in those where it is far from one

68

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 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)

69

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

70

Assessment of HAM and PEM to Find Analytical Solution for Calculating Displacement Functions of Geometrically Nonlinear Prestressed Cable Structures with Concentrated Mass  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, two powerful analytical methods, called He’s Parameter-Expanding Methods (PEM and Homotopy Analysis Method (HAM are used to calculating displacement functions of geometrically nonlinear prestressed cable structures. In this study, the results of two methods are compared and it is shown that one term in series expansions is sufficient to obtain a solution by using the PEM. Comparison of the obtained solutions with those obtained using numerical method shows that two methods are effective and convenient for solving this problem. These two methods introduce a capable tool for solving this kind of nonlinear problems.

M. Ghasempour

2009-01-01

71

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

72

Study of the fluid dynamic and the efficiency of displacement in oil-water systems; Estudo da fluidodinamica e da eficiencia de deslocamento em sistemas agua-oleo  

Energy Technology Data Exchange (ETDEWEB)

Several operations and procedures in the oil industry are related to immiscible displacement of a fluid by another one. Some examples can be listed: the natural and artificial oil elevation from wells, the pumping of high viscosity oils through pipelines using water injection and secondary oil recovery. The performance of the last one is a direct consequence of the interfacial phenomena inherent to oil/water systems. As occur in oil leakages from submarine pipelines, the phase inversion phenomenon can also be considered in this context. Therefore, it is of major importance to realize experimental analysis of the oil/water interface stability and the facts that leads to the fingering phenomenon appearance. This phenomenon is represented into the other one like one or more fingers. The mathematical model used to describe the immiscible displacement of another one is initially developed to Hele-Shaw cells. Experimental observations with a Hele-Shaw cell enable the evaluation of the proposed model and its capability to adequately describe the viscous fingering phenomenon related to physical (density, viscosity and interfacial tension) and geometric properties of the system. (author)

Fiorese, Eliana K.; Quadri, Marintho B.; Machado, Ricardo A.F.; Nogueira, Andre L.; Lopes, Toni J. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Quimica e de Alimentos; Baptista, Renan M. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2004-07-01

73

Displacement deformed quantum fields  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A displacement operator d_\\zeta is introduced, verifying commutation relations [d_\\zeta, a_f^\\dagger]=[d_\\zeta, a_f]=\\zeta(f)d_\\zeta with field creation and annihilation operators that verify [a_f,a_g]=0, [a_f,a_g^\\dagger]=(g,f), as usual. f and g are test functions, \\zeta is a Poincare invariant real-valued function on the test function space, and (g,f) is a Poincare invariant Hermitian inner product. The *-algebra generated by all these operators, and a state defined on it...

Morgan, Peter

2006-01-01

74

A molecular density functional theory to study solvation in water  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 sol...

Jeanmairet, Guillaume

2014-01-01

75

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

76

Impurities in the [18O]water target and their effect on the yield of an aromatic displacement reaction with [18F]fluoride  

International Nuclear Information System (INIS)

Fluorine-18 in the form of fluoride ion has widespread utility in PET radiochemistry. This paper explores the effect of possible metal ion contamination of the water on the yield of the displacement of a nitro group of dinitrobenzene by fluoride has been investigated as a model reaction for fluoride displacement. The metal ions were found to have a profound effect if they were at the level of the carbonate added to the synthetic procedure. The yields from the reaction are best fit by a model in which the metal ions complex the carbonate ion and thus reduce the pH which in turn reduces the efficiency of the reaction. The formation of [18F]fluoroacetate in the target was explored as a mode for making the fluoride in the target unreactive. It was found that essentially no fluoracetate was formed under our irradiation conditions. The sources of carrier fluoride were examined. It was found that carrier fluoride was introduced during the transfer of water into and out of the target and not during the irradiation. (Author)

77

Crystal Structure of Lysine Sulfonamide Inhibitor Reveals the Displacement of the Conserved Flap Water Molecule in Human Immunodeficiency Virus Type 1 Protease?  

Science.gov (United States)

Human immunodeficiency virus type 1 (HIV-1) protease has been continuously evolving and developing resistance to all of the protease inhibitors. This requires the development of new inhibitors that bind to the protease in a novel fashion. Most of the inhibitors that are on the market are peptidomimetics, where a conserved water molecule mediates hydrogen bonding interactions between the inhibitors and the flaps of the protease. Recently a new class of inhibitors, lysine sulfonamides, was developed to combat the resistant variants of HIV protease. Here we report the crystal structure of a lysine sulfonamide. This inhibitor binds to the active site of HIV-1 protease in a novel manner, displacing the conserved water and making extensive hydrogen bonds with every region of the active site. PMID:17596316

Nalam, Madhavi N. L.; Peeters, Anik; Jonckers, Tim H. M.; Dierynck, Inge; Schiffer, Celia A.

2007-01-01

78

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

79

Semiautomated Thyroid Volumetry Using 3D CT: Prospective Comparison With Measurements Obtained Using 2D Ultrasound, 2D CT, and Water Displacement Method of Specimen.  

Science.gov (United States)

OBJECTIVE. The objective of our study was to measure thyroid volumes using semiautomated 3D CT and to compare the 3D CT volumes with volumes measured using 2D ultrasound, 2D CT, and the water displacement method. SUBJECTS AND METHODS. In 47 patients, 2D ultrasound volumes and 2D CT volumes of the thyroid gland were estimated using the ellipsoid volume formula, and 3D CT volumes were calculated using semiautomated reconstructive techniques. All volume data were compared with thyroid specimen volumes obtained using the water displacement method and were statistically analyzed using the one-way ANOVA, the Pearson correlation coefficient (R), linear regression, and the concordance correlation coefficient (CCC). The processing time of semiautomated 3D CT thyroid volumetry was measured. RESULTS. The paired mean differences ± SD between the three imaging-determined volumes and the specimen volumes were 0.8 ± 3.1 mL for 2D ultrasound, 4.0 ± 4.7 mL for 2D CT, and 0.2 ± 2.5 mL for 3D CT. A significant difference in the mean thyroid volume was found between 2D CT and specimen volumes (p = 0.016) compared with the other pairs (p = 0.937 for 2D ultrasound mean volume vs specimen mean volume, and p = 0.999 for 3D CT mean volume vs specimen mean volume). Between specimen volume and 2D ultrasound volume, specimen volume and 2D CT volume, and specimen volume and 3D CT volume, R values were 0.885, 0.724, and 0.929, respectively, and CCC values were 0.876, 0.598, and 0.925, respectively. The mean processing time of semiautomated 3D CT thyroid volumetry was 7.0 minutes. CONCLUSION. Thyroid volumes measured using 2D ultrasound or semiautomated 3D CT are substantially close to thyroid specimen volumes measured using the water displacement method. Semiautomated 3D CT thyroid volumetry can provide a more reliable measure of thyroid volume than 2D ultrasound. PMID:25341167

Lee, Sun Jin; Chong, Semin; Kang, Kyung Ho; Hur, Joonho; Hong, Byung-Woo; Kim, Hyun Jung; Kim, Soo Jin

2014-11-01

80

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

International Nuclear Information System (INIS)

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

 
 
 
 
81

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

Energy Technology Data Exchange (ETDEWEB)

A study of oxide film formed inside pre cracked CT specimens during a rising displacement test in high temperature water (288 C) was performed in this study, The environmental conditions used during the experiments were similar to these found in Boiling Water Reactors (BWR): Normal Water Condition (NWC - 200 ppb O{sub 2}) and Hydrogen Water Chemistry (HWC - 125 ppb H2). The oxide films formed were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). In both cases the oxide film consisted of two layers identified as magnetite. In the case of HWC the results agree with previous reports that mention magnetite as a stable phase in reducing conditions. However the stable phase in oxidant conditions is hematite and this work shows the presence of magnetite crystals in the narrow crack of CT specimens in spite of the oxidant environmental condition. This situation confirms that inside the pre-cracked CT specimens the environmental conditions were different from the oxidant bulk, and probably a poor oxygen access and stagnant conditions within the narrow crack promoted a localized reducing environment that permitted the magnetite formation. Is evident that the crack growth studies should consider the conditions inside crack because they are significantly different. (Author)

Diaz S, A. [ININ, Carretera Mexico-Toluca s/n, 52750 LaMarquesa, Ocoyoacac (Mexico); Castano M, V. [Instituto de Fisica Aplicada, UNAM, Km 15.5 Carretera Queretaro-San Luis Potosi, Juriquilla, Queretaro (Mexico)]. e-mail: ads@nuclear.inin.mx

2007-07-01

82

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)

83

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

84

Temperature dependence of mean square displacement by IN13: a comparison between trehalose and sucrose water mixtures  

International Nuclear Information System (INIS)

An analysis in terms of elastic scans of the neutron intensity in mixtures of homologues disaccharides (i.e., trehalose and sucrose)/D2O as a function of temperature has been carried out. The study provides an effective way for characterizing the dynamical behavior, furnishing a set of parameters characterizing the 'flexibility' and the 'rigidity' that justifies the better cryptobiotic effect of trehalose in respect to sucrose. Elastic scans make evident a non-Gaussian behavior of the intensity profiles which is more marked for sucrose, with a dynamical transition at T?253 K and T?250 K for trehalose/D2O and sucrose/D2O mixtures, respectively

85

Temperature dependence of mean square displacement by IN13: a comparison between trehalose and sucrose water mixtures  

Energy Technology Data Exchange (ETDEWEB)

An analysis in terms of elastic scans of the neutron intensity in mixtures of homologues disaccharides (i.e., trehalose and sucrose)/D{sub 2}O as a function of temperature has been carried out. The study provides an effective way for characterizing the dynamical behavior, furnishing a set of parameters characterizing the 'flexibility' and the 'rigidity' that justifies the better cryptobiotic effect of trehalose in respect to sucrose. Elastic scans make evident a non-Gaussian behavior of the intensity profiles which is more marked for sucrose, with a dynamical transition at T{approx}253 K and T{approx}250 K for trehalose/D{sub 2}O and sucrose/D{sub 2}O mixtures, respectively.

Magazu, S.; Migliardo, F.; Mondelli, C.; Romeo, G

2003-08-01

86

Displacement trends in DRC  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Internal displacement has plagued the Democratic Republic of Congo (DRC) for nearly 20 years. This article provides an overview of the scale and causes of displacement during this period as well as efforts to address the assistance and protection needs of internally displaced persons (IDPs).

Greta Zeender; Jacob Rothing

2010-01-01

87

Displacement trends in DRC  

Directory of Open Access Journals (Sweden)

Full Text Available Internal displacement has plagued the Democratic Republic of Congo (DRC for nearly 20 years. This article provides an overview of the scale and causes of displacement during this period as well as efforts to address the assistance and protection needs of internally displaced persons (IDPs.

Greta Zeender

2010-11-01

88

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

Energy Technology Data Exchange (ETDEWEB)

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

Li Yan; Huang Yanfeng; Jiang Yan; Tian Bolin; Han Fei [Research Center for Analytical Sciences, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin 300071 (China); Yan Xiuping, E-mail: xpyan@nankai.edu.cn [Research Center for Analytical Sciences, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin 300071 (China)

2011-04-29

89

Water-displacement plethysmography: a technique for the simultaneous thermal manipulation and measurement of whole-hand and whole-foot blood flows.  

Science.gov (United States)

The purpose of this project was to design, construct and validate water-displacement plethysmographs for the forearm, hand and foot that could clamp segmental skin temperature whilst simultaneously measuring cutaneous blood flow. Two experiments were performed. In the first, the forearm plethysmograph was validated against a mercury-in-silastic plethysmograph under thermoneutral conditions, with and without forearm heating. Cutaneous vascular conductance was elevated almost three-fold by this treatment, however, there were no significant differences between the two forms of plethysmography in either state (P?>?0.05). In study two, hand and foot blood flows were measured under clamped thermoneutral conditions, but with three local skin temperature treatments (5, 25, 40?°C). The hand had significantly higher blood flows than the foot at both 25?°C (4.07 versus 2.20?mL.100?mL(?-?1).min(?-?1); P heat loss and conservation, and these plethysmographs will now be used to map cutaneous vascular responses (forearm, hand, calf, foot) across combinations of core and local skin temperatures. PMID:25120039

Caldwell, Joanne N; Taylor, Nigel A S

2014-09-01

90

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

91

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

Directory of Open Access Journals (Sweden)

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

Batta Vineet

2012-06-01

92

Improved association in a classical density functional theory for water  

International Nuclear Information System (INIS)

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

93

Improved association in a classical density functional theory for water  

Science.gov (United States)

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

2014-03-01

94

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

95

XY displacement device:  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An XY-displacement device (1) with a four-fold symmetry comprises a reference frame (10); an object mount (20) for holding an object (22) to be displaced; an X-manipulator (100) coupled between the reference frame (10) and the object mount (20), which provides a rigid coupling between the object mount (20) and a piezoelectric X-actuator (140), allows a Y-displacement of the object mount (20) relative to the reference frame (10), and counteracts a Z-displacement of the object mount (20) relati...

Heerens, W. C.; Laham, C. D.; Holman, A. E.

1997-01-01

96

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

97

Water in Photosystem II: structural, functional and mechanistic considerations.  

Science.gov (United States)

Water is clearly important for the functioning of Photosystem II (PSII). Apart from being the very substrate that needs to be transported in this water oxidation enzyme, water is also vital for the transport of protons to and from the catalytic center as well as other important co-factors and key residues in the enzyme. The latest crystal structural data of PSII have enabled detailed analyses of the location and possible function of water molecules in the enzyme. Significant progress has also been made recently in the investigation of channels and pathways through the protein complex. Through these studies, the mechanistic significance of water for PSII is becoming increasingly clear. An overview and discussion of key aspects of the current research on water in PSII is presented here. The role of water in three other systems (aquaporin, bacteriorhodopsin and cytochrome P450) is also outlined to illustrate further points concerning the central significance that water can have, and potential applications of these ideas for continued research on PSII. It is advocated that water be seen as an integral part of the protein and far from a mere solvent. PMID:23978393

Linke, Katrin; Ho, Felix M

2014-01-01

98

Continuing displacement in DRC  

Directory of Open Access Journals (Sweden)

Full Text Available Despite successful elections in late 2006 and an overall increase in the level of stability, over a million people remain displaced in the east of the Democratic Republic of Congo (DRC. The situation is particularly worrying in North Kivu where over a hundred thousand people have been displaced in recent months.

Greta Zeender

2007-07-01

99

Continuing displacement in DRC  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Despite successful elections in late 2006 and an overall increase in the level of stability, over a million people remain displaced in the east of the Democratic Republic of Congo (DRC). The situation is particularly worrying in North Kivu where over a hundred thousand people have been displaced in recent months.

Greta Zeender

2007-01-01

100

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

 
 
 
 
101

Intrinsic Mean Square Displacements in Proteins  

CERN Document Server

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

Vural, Derya

2012-01-01

102

Abomasal displacement in cattle  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

103

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

104

Determination of chromium by radiochemical displacement  

International Nuclear Information System (INIS)

A rapid and sensitive method has been developed for the determination of microgram amounts of chromium based on the radiochemical displacement of 65Zn from labeled Zn-[1-(2-pyridylazo-2-naphthol]2 complex by chromium. The effect of pH on the displacement of 65Zn was studied. 5-65 ?g of chromium could be determined with great accuracy. The effect of various ions on the displacement of 65Zn by chromium was investigated and the method developed was utilized for the determination of chromium content present in geological water samples. The results were compared with values obtained by Atomic Absorption Spectrophotometry. (author) 3 refs.; 2 figs.; 1 tab

105

Dynamics of water/methanol mixtures at functionalized chromatographic interfaces.  

Science.gov (United States)

Fully atomistic simulations of water/methanol mixtures of varying compositions (80/20 and 50/50) at chromatographic interfaces with different functionalizations are presented. The dynamical properties in terms of equilibration times and solvent exchange dynamics are characterized and found to depend on the different systems on the nanosecond time scale. The solvent density profile and the structuring of the stationary phase differ for derivatizations including (-CN, NO(2), -NH(2), -C(6)H(5)) of the C(18) chain. The time scale and intensity of the water exchange dynamics differs for the different realizations of the chromatographic systems and ranges from 200 to 500 ps. Water exchange rates depend on solvent composition as well as on the functionalization of alkyl chains. Simulations with acridine as a probe molecule provide atomistic insight into the slot model. PMID:22839971

Gupta, Prashant Kumar; Meuwly, Markus

2012-09-01

106

Characterization of silica-functionalized carbon nanotubes dispersed in water  

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-01-15

107

Testing a full-range soil-water retention function in modeling water potential and temperature  

Science.gov (United States)

Recent work has emphasized development of full-range water-retention functions that are applicable under both wet and dry soil conditions, but evaluation of such functions in numerical modeling has been limited. Here we show that simulations using the Rossi-Nimmo (RN) full-range function compared favorably with those using the common Brooks-Corey function and that the RN function can improve prediction of water potentials in near-surface soil, particularly under dry conditions. Simulations using the RN function also improved prediction of temperatures throughout the soil profile. Such improvements could be important for calculations of liquid and vapor flow in near-surface soils and in deep unsaturated zones of arid and semiarid regions.

Andraski, B.J.; Jacobson, E.A.

2000-01-01

108

Functional reconstitution of the isolated erythrocyte water channel CHIP28.  

Science.gov (United States)

Measurements of water permeability indicate the existence of a facilitated water transporting pathway in erythrocytes, kidney tubules and amphibian urinary bladder. Two lines of evidence suggest that one type of water channel is an approximately 30-kDa protein: the approximately 30-kDa target size determined by radiation inactivation (van Hoek, A. N., Hom, M. L., Luthjens, L. H., de Jong, M. D., Dempster, J. A., and van Os, C. H. (1991) J. Biol. Chem. 266, 16633-16635) and the increased water permeability in oocytes that express mRNA encoding a 28-kDa erythrocyte protein (CHIP28, Preston, B. M., Carroll, T. P., Guggino, W. B., and Agre, P. (1992) Science 256, 385-387). We report direct evidence that CHIP28 is the erythrocyte water channel. Osmotic water permeability (Pf) remained high (0.029 cm/s, 37 degrees C) when erythrocyte membranes were stripped of nearly all proteins except for CHIP28. N-terminal sequence analysis confirmed that the 28-kDa protein was CHIP28. Pf in proteoliposomes reconstituted with solubilized CHIP28 was high (Pf = 0.03 cm/s, 37 degrees C), the activation energy was low (2.2 kcal/mol), and Pf was decreased by greater than 50-fold by mercurial sulfhydryl reagents and Me2SO. The single-channel water permeability was approximately 10(-13) cm3/s, slightly higher than that of the gramicidin A channel. The water channel excluded the small solute urea. These data establish a procedure to reconstitute functional water channels into liposomes and demonstrate that CHIP28 is the erythrocyte water channel. PMID:1526967

van Hoek, A N; Verkman, A S

1992-09-15

109

Frequency response of polypyrrole trilayer actuator displacement  

Science.gov (United States)

Conducting polymer trilayers are attractive for use in functional devices, given low actuation voltages, operation in air and potentially useful stresses and strains; however, their dynamic behavior must be understood from an engineering perspective before they can be effectively incorporated into a design. As a step towards the identification of the actuator dynamics, frequency response analysis has been performed to identify the magnitude and phase shift of displacement in response to a sinusoidal voltage input. The low damping of the trilayer operating in air and the use of a laser displacement sensor has allowed the frequency response to be continuously identified up to 100Hz, demonstrating a resonant peak at 80Hz for a 10mm long actuator. Two linear transfer function models have been fitted to the frequency response of the trilayer displacement (i) a 3rd order model to represent the dynamics below 20Hz and (ii) a higher complexity 6th order model to also include the resonant peak. In response to a random input signal, the 3rd order model coarsely follows the experimental identified displacement, while the 6th order model is able to fully simulate the real trilayer movement. Step responses have also been obtained for the 3rd and 6th order transfer functions, with both models capable of following the first 4 seconds of experimental displacement. The application of empirical transfer function models will facilitate accurate simulation and analysis of trilayer displacement, and will lead to the design of accurate positional control systems.

John, Stephen; Alici, Gursel; Cook, Christopher

2008-03-01

110

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

111

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

112

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

113

Periodic Density Functional Theory Study of Water Adsorption on the a-Quartz (101) Surface.  

Energy Technology Data Exchange (ETDEWEB)

Plane wave density functional theory (DFT) calculations have been performed to study the atomic structure, preferred H2O adsorption sites, adsorption energies, and vibrational frequencies for water adsorption on the R-quartz (101) surface. Surface energies and atomic displacements on the vacuum-reconstructed, hydrolyzed, and solvated surfaces have been calculated and compared with available experimental and theoretical data. By considering different initial positions of H2O molecules, the most stable structures of water adsorption at different coverages have been determined. Calculated H2O adsorption energies are in the range -55 to -65 kJ/mol, consistent with experimental data. The lowest and the highest O-H stretching vibrational bands may be attributed to different states of silanol groups on the watercovered surface. The dissociation energy of the silanol group on the surface covered by the adsorption monolayer is estimated to be 80 kJ/mol. The metastable states for the protonated surface bridging O atoms (Obr), which may lead to hydrolysis of siloxane bonds, have been investigated. The calculated formation energy of a Q2 center from a Q3 center on the (101) surface with 2/3 dense monolayer coverage is equal to 70 kJ/mol which is in the range of experimental activation energies for quartz dissolution.

Bandura, Andrei V. [St. Petersburg State University, St. Petersburg, Russia; Kubicki, James D. [Pennsylvania State University; Sofo, Jorge O. [Pennsylvania State University

2011-01-01

114

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

115

Water hammer prediction and control: the Green's function method  

Science.gov (United States)

By Green's function method we show that the water hammer (WH) can be analytically predicted for both laminar and turbulent flows (for the latter, with an eddy viscosity depending solely on the space coordinates), and thus its hazardous effect can be rationally controlled and minimized. To this end, we generalize a laminar water hammer equation of Wang et al. (J. Hydrodynamics, B2, 51, 1995) to include arbitrary initial condition and variable viscosity, and obtain its solution by Green's function method. The predicted characteristic WH behaviors by the solutions are in excellent agreement with both direct numerical simulation of the original governing equations and, by adjusting the eddy viscosity coefficient, experimentally measured turbulent flow data. Optimal WH control principle is thereby constructed and demonstrated.

Xuan, Li-Jun; Mao, Feng; Wu, Jie-Zhi

2012-04-01

116

Water Purification Using Functional Nanomaterials: Sequestering Toxic Heavy Metals  

Energy Technology Data Exchange (ETDEWEB)

Water, and water quality, are issues of critical importance to the future of humankind. Our water supply has been contaminated by a wide variety of industrial, military and natural sources. There is a serious need for technologies to remove toxic heavy metals and radionuclides from the world’s water supplies. Surfactant templated synthesis of mesoporous ceramics provides a versatile foundation upon which to create high efficiency environmental sorbents. These nanoporous ceramics condense a huge amount of surface area into a very small volume. These mesoporous architectures can be subsequently functionalized through molecular self-assembly. These functional mesoporous materials offer significant capabilities in terms of removal of heavy metals and radionuclides from groundwater and other liquid media. They are highly efficient sorbents, whose interfacial chemistry can be fine-tuned to selectively sequester a specific target species, such as heavy metals, tetrahedral oxometallate anions and radionuclides. Their rigid, open pore structure allows for rapid, efficient sorption kinetics. This manuscript provides an overview of the design, synthesis and performance of the sorbent materials.

Fryxell, Glen E.

2008-02-01

117

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)

118

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

119

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)

120

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

 
 
 
 
121

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

122

DISPLACEMENT-DISPERSIVE LIQUID-LIQUID MICROEXTRACTION BASED ON SOLIDIFICATION FLOATING ORGANIC DROP TRACE AMOUNTS OF LEAD IN WATER SAMPLE PRIOR TO FLAME ATOMIC ABSORPTION SPECTROMETRY DETERMINATION  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english In this study, a novel method using displacement-dispersive liquid-liquid microextraction based on solidification of floating organic drop in complicated samples prior to flame atomic absorption spectrometry determination was developed. This method involves two consecutive dispersive liquid-liquid m [...] icroextraction based on solidification. In step I, Zn(II) ions reacted with ammonium pyrrolidine dithio carbamate (APDC) to form Zn-APDC complex and was extracted with the solidified floating organic drop microextraction procedure using 1-undecanol (extraction solvent) and ethanol (dispersive solvent). In step II, after centrifugation and solidification, the separated drop was dissolved in dimethylformamide (DMF) and then dispersed into the sample solution containing lead ion and another dispersive liquid-liquid microextraction based on solidification procedure was carried out. Due to the greater stability of Pb-APDC, Pb displaces Zn from the pre-extracted Zn-APDC and preconcentration of Pb was achieved. Under the optimized conditions, the calibration curve was linear in the range of 4-700 ng mL-1 with detection limit of 0.7 ng mL-1(3a b). The relative standard deviation of ±1.6% was obtained (n=7) and the enrichment factor was found to be 35.0.

DARYOUSH, AFZALI; MARYAM, FAYAZI; ALIMOSTA, FAVI.

1593-15-01

123

DISPLACEMENT-DISPERSIVE LIQUID-LIQUID MICROEXTRACTION BASED ON SOLIDIFICATION FLOATING ORGANIC DROP TRACE AMOUNTS OF LEAD IN WATER SAMPLE PRIOR TO FLAME ATOMIC ABSORPTION SPECTROMETRY DETERMINATION  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english In this study, a novel method using displacement-dispersive liquid-liquid microextraction based on solidification of floating organic drop in complicated samples prior to flame atomic absorption spectrometry determination was developed. This method involves two consecutive dispersive liquid-liquid m [...] icroextraction based on solidification. In step I, Zn(II) ions reacted with ammonium pyrrolidine dithio carbamate (APDC) to form Zn-APDC complex and was extracted with the solidified floating organic drop microextraction procedure using 1-undecanol (extraction solvent) and ethanol (dispersive solvent). In step II, after centrifugation and solidification, the separated drop was dissolved in dimethylformamide (DMF) and then dispersed into the sample solution containing lead ion and another dispersive liquid-liquid microextraction based on solidification procedure was carried out. Due to the greater stability of Pb-APDC, Pb displaces Zn from the pre-extracted Zn-APDC and preconcentration of Pb was achieved. Under the optimized conditions, the calibration curve was linear in the range of 4-700 ng mL-1 with detection limit of 0.7 ng mL-1(3a b). The relative standard deviation of ±1.6% was obtained (n=7) and the enrichment factor was found to be 35.0.

DARYOUSH, AFZALI; MARYAM, FAYAZI; ALIMOSTA, FAVI.

124

Applications of water-based magnetic gradiometry to assess the geometry and displacement for concealed faults in the southern Adirondack Mountains, New York, U.S.A  

Science.gov (United States)

An integrated magnetic gradiometry and structural analysis was conducted on three lakes in the southern Adirondacks Mountains, New York, in order to develop a geometric and kinematic model for concealed and long lived faults that transect the Proterozoic basement structures, offset Paleozoic strata to the south, and may be associated with the development of the post-Paleozoic cratonic dome (the Adirondack dome). Two lakes occur along the trace of two of the most prominent topographic lineaments that have been proposed to be faults in the southern Adirondack Mountains, and a third lake is located at the apparent fault intersection. Hinkley Lake occurs over the east-west trending lineament that corresponds to the trace of the Prospect fault. Indian Lake resides in a set of north-northeast trending pronounced lineaments that transect an anorthosite-cored structural dome and are inferred to be faults on the NYS geologic map. Piseco Lake is immediately adjacent to the intersection of the two proposed fault zones (Prospect and Indian Lake fault zones). Magnetic surveys were conducted on all three lakes, resulting in anomaly maps. Accompanying two dimensional geologic models for Hinkley and Piseco Lake were produced. At Piseco Lake, field evidence supports a brittle deformation history with sinistral-normal displacement. A similar deformation history is consistent with field data collected at Indian Lake. Correlation of the two dimensional magnetic models resulted in a sinistral, releasing-bend fault geometry beneath Piseco Lake, and the fault truncation of a granitic gneiss cored antiform for the subsurface geology of Hinkley Lake. The magnetic data and models suggest that Piseco Lake resides over a sinistral, pull-apart structure with sufficient throw to preserve the lowermost Paleozoic strata that once covered much of the Adirondack dome. This would account for both sinistral strike-slip and normal displacement on the interpreted faults, at Piseco and Indian Lakes, and rotation of structural blocks as the result of fault interaction. Relative timing, regional relationships, and ties to published ages suggest that the distribution of the faults is a relic of Neoproterozoic Iapetan rifting, Paleozoic displacement, and Mesozoic uplift of the Adirondack dome. Finally there is probable correlation of these faults with modern seismic activity.

Valentino, David W.; Chiarenzelli, Jeffrey R.; Hewitt, Elise M.; Valentino, Joshua D.

2012-01-01

125

Classical density functional calculation of radial distribution functions of liquid water  

Science.gov (United States)

We have calculated the radial distribution functions (RDFs) of liquid water on the basis of the classical density functional theory combined with the reference interaction site model for molecular liquids. The density expansion for the Helmholtz free energy functional is retained up to the third order in order to take into account the effects of the bridge functions beyond the hypernetted-chain (HNC) approximation. The ternary direct correlation functions in the expression of the bridge functions are then given by a factorization approximation in terms of the site-site pair correlation functions, thus leading to a closed set of integral equations for the determination of the RDFs. We have obtained a numerical result in which a poor description by the HNC approximation for the second peak of the oxygen-oxygen RDF at room temperature has been improved to some extent by incorporating the oxygen-oxygen bridge function. Some directions toward more satisfactory agreement with computer simulation results are addressed as well.

Tanaka, Shigenori; Nakano, Miki

2014-02-01

126

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, Flavio Antonio; Garrido, Nuno Domingos; Martins da Silva, Antonio Jose Rocha

2014-01-01

127

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

2014-06-28

128

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).

129

Electrical conductivity of shocked water from density functional theory.  

Energy Technology Data Exchange (ETDEWEB)

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).

Desjarlais, Michael Paul; Mattsson, Thomas Kjell Rene

2005-07-01

130

Atmospheric pressure loading displacement of SLR stations  

Science.gov (United States)

This paper addresses the local displacement at ground stations of the world-wide Satellite Laser Ranging (SLR) network induced by atmospheric pressure variations. Since currently available modelling options do not satisfy the requirements for the target application (real-time availability, complete coverage of SLR network), a new representation is developed. In a first step, the 3-dimensional displacements are computed from a 6-hourly grid of 1°×1° global pressure data obtained from the ECMWF, for the period 1997-2002. After having been converted into pressure anomalies, this pressure grid is propagated into horizontal and vertical station displacements using Green's functions and integrating contributions covering the entire globe; oceans are assumed to follow the inverted barometer (IB) approximation. In the next step, a linear regression model is developed for each station that approximates the time-series of the predicted vertical displacements as well as possible; this regression model relates the vertical displacement of a particular station to the local (and instantaneous) pressure anomaly. It is shown that such a simple model may represent the actual vertical displacements with an accuracy of better than 1 mm; horizontal displacements are shown to be negligible. Finally, the regression model is tested on actual SLR data on the satellites LAGEOS-1 and LAGEOS-2, covering the period January 2002 until April 2003 (inclusive). Also, two model elements are shown to be potential risk factors: the global pressure field representation (for the convolution method) and the local reference pressure (for the regression method). The inclusion of the atmospheric pressure displacement model gives improvements on most of the elements of the computations, although the effects are smaller than expected since the nominal effect is absorbed by solved-for satellite parameters.

Bock, D.; Noomen, R.; Scherneck, H.-G.

2005-04-01

131

River Elbe water quality: MISO Transfer Function modelling  

Science.gov (United States)

The paper will explore here the specific features of algae generation in the River Elbe, Germany. Multiple-Input, Single Output (MISO), non-linear transfer function modelling, using the Stochastic Transfer Function (STF) and State Dependent Parameter (SDP) modelling tools in the CAPTAIN Matlab toolbox, is developed as a statistical counterpart of a mechanistic model with the objective of combining the two approaches using the Data-Based, Mechanistic (DBM) modelling approach. In this paper we focus on the description of the process of oxygen concentration changes, which mainly depends on the algae. The main goal of the paper is to demonstrate the utility of the Captain toolbox in water quality modelling and the analysis of the relations between various water quality variables. The results of the analysis show that the linear STF models, based on temperature and radiation as input variables, may be used for the estimation of the average behaviour of the oxygen concentrations in the Elbe. However, changes related to the dependence of biological processes on nutrients are not explained by this linear model. On the other hand, the introduction of pH as an additional input representing, in some sense, the state of biological processes affecting water quality, yields much better estimation and validation results. Also, our initial consideration of the non-linear STF models in DBM terms has led to a multi-rate model, with two different sampling intervals: one hourly for the "external forces" of temperature and radiation; and the other 12 hourly for the "internal force" of pH. This multi-rate model indicates the existence of differences in the physical mechanisms governing the relationships between temperature and radiation and DO; and pH and DO.

Romanowicz, R.; Young, P. C.

2003-04-01

132

Crack-opening displacement transducer  

Science.gov (United States)

Crack-opening displacement transducer consists of 30 deg cone, coil spring, and linear-displacement transducer. Conical probe is used to measure crack opening. Cone is pressed firmly into crack by spring. As applied load causes crack to open up, cone is pushed further into it. Movement of cone, and thus crack growth, is monitored by linear-displacement transducer. Method gives more accurate measurement of crack-opening displacement of very narrow slots.

Simonds, R. A.

1980-01-01

133

Truncation Effects of Shift Function Methods in Bulk Water Systems  

Directory of Open Access Journals (Sweden)

Full Text Available A reduction of the cost for long-range interaction calculation is essential for large-scale molecular systems that contain a lot of point charges. Cutoff methods are often used to reduce the cost of long-range interaction calculations. Molecular dynamics (MD simulations can be accelerated by using cutoff methods; however, simple truncation or approximation of long-range interactions often offers serious defects for various systems. For example, thermodynamical properties of polar molecular systems are strongly affected by the treatment of the Coulombic interactions and may lead to unphysical results. To assess the truncation effect of some cutoff methods that are categorized as the shift function method, MD simulations for bulk water systems were performed. The results reflect two main factors, i.e., the treatment of cutoff boundary conditions and the presence/absence of the theoretical background for the long-range approximation.

Kazuaki Z. Takahashi

2013-08-01

134

Nonlinear Brownian motion - mean square displacement  

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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

135

Does oxidation affect the water functionality of myofibrillar proteins?  

Science.gov (United States)

Water-binding properties of myofibrils extracted from porcine muscle, and added hemoglobin with and without exposure to H2O2, were characterized using low-field proton NMR T2 relaxometry. The effects of pH and ionic strength in the samples were investigated as pH was adjusted to 5.4, 6.2, and 7.0 and ionic strength was adjusted to 0.29, 0.46, and 0.71 M, respectively. The formation of dityrosine as a measure of oxidative protein cross-linking revealed a significant increase in dityrosine concentrations upon H2O2 activation. The formation of dityrosine was strongly pH-dependent and increased with decreasing pH. In addition, increased levels of thiobarbituric acid reactive substances were observed upon addition of H2O2, implying that lipid oxidation was enhanced, however, with a different oxidation pattern as compared to the myofibrillar proteins. Low-field NMR relaxation measurements revealed reduced T2 relaxation times upon H2O2 activation, which corresponds to reduced water-holding capacity upon oxidation. However, a direct relationship between degree of oxidation and T2 relaxation time was not observed with various pH values and ionic strengths, and further studies are needed for a complete understanding of the effect of oxidation on myofibrillar functionality. PMID:17316016

Bertram, Hanne Christine; Kristensen, Mette; Østdal, Henrik; Baron, Caroline P; Young, Jette F; Andersen, Henrik Jørgen

2007-03-21

136

Groundwater resources monitoring and population displacement in northern Uganda  

Science.gov (United States)

Northern Uganda has been devastated by more than 20 years of open conflict by the LRA (Lord's Resistance Army) and the Government of Uganda. This war has been marked by extreme violence against civilians, who had been gathered in protected IDP (Internally Displaced Persons) camps. At the height of the displacement in 2007, the UN office for coordination of humanitarian affairs, estimated that nearly 2.5 million people were interned into approximately 220 camps throughout Northern Uganda. With the improved security since mid-2006, the people displaced by the conflict in Northern Uganda started to move out of the overcrowded camps and return either to their villages/parishes of origin or to resettlement/transit sites. However, basic water, sanitation and hygiene infrastructure in the return areas or any new settlements sites are minimal. People returning to their villages of origin encounter a situation where in many cases there is no access to safe water. Since 1998 ACF (Action Against Hunger, part of the Action Contre la Faim International Network) activities have been concentrated in the Acholi and Lango regions of Northern Uganda. ACF's WASH (Water, sanitation and hygiene) department interventions concern sanitation infrastructure, hygiene education and promotion as well as water points implementation. To ensure safe water access, actions are focused in borehole construction and traditional spring rehabilitation, also called "protected" springs. These activities follow the guidelines as set forth by the international WASH cluster, led by UNICEF. A three year project (2008-2010) is being implemented by ACF, to monitor the available groundwater resources in Northern Uganda. The main objectives are: 1. to monitor the groundwater quality from existing water points during different hydrological seasons, 2. to identify, if any, potential risks of contamination from population concentrations and displacement, lack of basic infrastructure and land use, and finally 3. to provide a guideline for a sustainable exploration of groundwater resources within the investigated regions, relating to population movements and potential of aquifers. To achieve these objectives a) groundwater samples are collected and analyzed (microbiologically, chemically and physically) from all types of water points, boreholes and "protected" springs, during rainy, dry and intermediate seasons, b) a network of piezometers is being installed for monitoring groundwater level, and comparison with available rainfall data will define groundwater balance. During these steps results are compared with the population's displacement and density in order to quantify the consequences towards the groundwater resources. Preliminary results after microbiological analysis show the inadequacy of traditional "protected" springs in providing safe water. Feacal pollution is observed in "protected" springs even though it was not being observed before and during rehabilitation. It is mainly due to recent population concentration around the available water resources and the lack of comprehensive hydrogeological study of the functioning of the near surface aquifers. Accordingly all operations concerning spring rehabilitation are on hold. No evidence regarding microbiological contamination was found from borehole water samples. However, high concentration in ferrous iron and total iron was found in several boreholes. Concentrations in the water of weathered bedrock are expected and specific treatment is necessary.

Chalikakis, K.; Hammache, Y.; Nawa, A.; Slinski, K.; Petropoulos, G.; Muteesasira, A.

2009-04-01

137

Fiber Optic Displacement Sensor with New Reflectivity Compensation Method  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, a fiber optic displacement sensor with a new reflectivity compensation method is presented. The proposed compensation method is based on two light receiving channels with characteristic displacement sensitivities. The sensitivity characteristic for each channel is achieved by using fibers with different numerical apertures. The ratio of the intensity values of the two receiving channels is a function of the object displacement and fairly independ...

Ansgar Wego; Gundolf Geske

2013-01-01

138

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

139

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

140

Displacements, mean-squared displacements, and codisplacements for the calculation of nonequilibrium properties.  

Science.gov (United States)

We study two situations in which nonequilibrium phenomena can be efficiently calculated using displacements, mean-squared displacements, or codisplacements instead of accumulating velocities or currents. The flow velocity profile for a fluid confined within a pore can be expressed as a sum of displacements within slabs from a molecular dynamics trajectory. In this form, an accurate flow profile is obtained from very sparse sampling of the trajectory. We also recast the linear response theory expression for the flow velocity profile in terms of mean codisplacements and demonstrate that this provides an efficient route for estimating the Green-Kubo expression for the velocity profile. Finally, we calculate the ionic contribution to the frequency-dependent electric susceptibility using dipolar displacements, instead of the conventional current-current correlation function. We expect these methods to be useful for generating transport properties from stored trajectories in very large systems or systems where relaxation times are long. PMID:24791611

Agnihotri, Mithila V; Chen, Si-Han; Beck, Corey; Singer, Sherwin J

2014-07-17

 
 
 
 
141

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

142

Displacement Parameter Inversion for a Novel Electromagnetic Underground Displacement Sensor  

Science.gov (United States)

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. PMID:24858960

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

2014-01-01

143

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

144

Shore line displacement in Oeregrundsgrepen  

International Nuclear Information System (INIS)

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

145

Displacement interpolations from a Hamiltonian point of view  

CERN Document Server

A large part of the optimal transportation theory is devoted to the study of convexity properties of functionals along a special kind of curves, called displacement interpolations, in the space of probability measures. In this paper, we study displacement interpolations from the point of view of Hamiltonian systems and give a unifying approach to various known results.

Lee, Paul W Y

2012-01-01

146

National response to internal displacement  

Directory of Open Access Journals (Sweden)

Full Text Available In many cases the international community acts to protect and assist the world's internally displaced people in absence of responsible and effective national action. This is, at least partly, because countries experiencing crises of internal displacement are unlikely to possess national institutions capable of effectively providing their displaced citizens with the necessary support. Strengthening national capacity for response is essential in order that governments themselves can assume immediate responsibility in humanitarian emergencies without having to depend on external aid.

Jennifer McLean

1998-04-01

147

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

148

Uncertainty in Fuzzy Membership Functions for a River Water Quality Management Problem  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Uncertainty associated with fuzzy membership functions for a water quality management problem is addressed through interval grey numbers. The lower and upper bounds of the membership functions are expressed as interval grey numbers, and the membership functions are modeled as imprecise membership functions. A grey fuzzy optimization model for water quality management of a river system is developed. Application of the optimization model with imprecise membership functions is illustrated with a...

Karmakar, Subhankar; Mujumdar, Pp

2004-01-01

149

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

150

Progressive brain compression; Changes in vital physiological variables, correlated with brain tissue water content and brain tissue displacement. Experimental MR imaging in dogs  

Energy Technology Data Exchange (ETDEWEB)

Continuous recording of vital physiological variables and sequential MR imaging were performed simultaneously during continuous expansion of an epidural rubber balloon over the left hemisphere in anaesthetised dogs. Balloon expansion led to a progressive and slgithly nonlinear rise in intracranial CSF pressures and a full in local perfusion pressures. Changes in systemic arterial pressure, pulse rate, and respiration rate usually appeared at a balloon volume of 4% to 5% of the intracranial volume (reaction volume), together with a marked transtentorial pressure gradient and MR imaging changes consistent with tentorial herniation. Respiratory arrest occurred at a balloon volume of approximately 10% of the intracranial volume (apnoea volume), which was associated with occulsion of the cisterna magna, consistent with some degree of foramen magnum herniation. Increase in tissue water was observed beginning at approximately the reaction volume, presumably due to ischaemic oedema, due to the fall in perfusion pressures. (orig.).

Thuomas, K.AA. (Depts. of Diagnostic Radiology and Neurosurgery, Univ. Hospital, Uppsala (Sweden) Inst. of Surgical Research, National Hospital, Oslo (Norway). Section of Experimental Neurosurgery); Vlajkovic, S. (Depts. of Diagnostic Radiology and Neurosurgery, Univ. Hospital, Uppsala (Sweden) Inst. of Surgical Research, National Hospital, Oslo (Norway). Section of Experimental Neurosurgery); Ganz, J.C. (Depts. of Diagnostic Radiology and Neurosurgery, Univ. Hospital, Uppsala (Sweden) Inst. of Surgical Research, National Hospital, Oslo (Norway). Section of Experimental Neurosurgery); Nilsson, P. (Depts. of Diagnostic Radiology and Neurosurgery, Univ. Hospital, Uppsala (Sweden) Inst. of Surgical Research, National Hospital, Oslo (Norway). Section of Experimental Neurosurgery); Bergstroem, K. (Depts. of Diagnostic Radiology and Neurosurgery, Univ. Hospital, Uppsala (Sweden) Inst. of Surgical Research, National Hospital, Oslo (Norway). Section of Experimental Neurosurgery); Ponten,

1993-05-01

151

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) 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)

152

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

153

Investigations on water jets - functional interdependences between selected jet parameters  

Energy Technology Data Exchange (ETDEWEB)

The nozzles used for wet dust abatement in mining are identified by their construction type, pressure, and throughput. These data should be supplemented by further data, e.g. jet formation, water distribution on the sprayed surface, sprayed surface area, droplet size and distribution. The experimental set-up and results are described, and the interdependences between nozzle size, water pressure and water volume are established. The experiments were carried out with different types of nozzles.

Bauer, H.D.; Werner, W.

1982-01-01

154

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

Science.gov (United States)

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

155

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.

156

Borehole optical lateral displacement sensor  

Science.gov (United States)

There is provided by this invention an optical displacement sensor that utilizes a reflective target connected to a surface to be monitored to reflect light from a light source such that the reflected light is received by a photoelectric transducer. The electric signal from the photoelectric transducer is then imputed into electronic circuitry to generate an electronic image of the target. The target`s image is monitored to determine the quantity and direction of any lateral displacement in the target`s image which represents lateral displacement in the surface being monitored. 4 figs.

Lewis, R.E.

1998-10-20

157

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

158

Functional oxygenated groups of carbon and their role in the water absorption process when preparing coal/water mixtures  

Energy Technology Data Exchange (ETDEWEB)

Certain functional oxygenated groups of carbon enhance water absorption and play a significant role in the preparation of coal/water mixtures. There is a number of analytical methods available for determining the carboxyl, hydroxyl and carbonyl groups. The authors describe the properties of these functional groupings, their analytical determination and the effect of the prevailing atmosphere, during the crushing stage, on the modification of the oxygenated groups and on the water absorption rate. It concludes by discussing the results of their investigation. 47 references.

Tartarelli, R.; Belli, R.

1985-09-01

159

Investigations of water jets - functional relationships between certain jet parameters  

Energy Technology Data Exchange (ETDEWEB)

Many water jets are used underground for dust suppression. They differ in construction, shape of spray, pressure and flow, but in order to evaluate their effectiveness, these parameters are often insufficient. Jet formation, water distribution, droplet size and distribution are also of great importance and should be considered. A series of investigations was carried out in order to clarify the relationship between these parameters and to develop reproducible test methods and objective evaluation criteria.

Bauer, D.; Werner, W.

1982-09-01

160

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

 
 
 
 
161

Density functional theory simulations of water-metal interfaces: waltzing waters, a novel 2D ice phase, and more  

Energy Technology Data Exchange (ETDEWEB)

There are few molecules, if any, more important than water. Yet remarkably little is known about how it interacts with solid surfaces, particularly at the all important atomic level. This is true despite widespread general interest and compelling environmental and economic incentives. Here, I discuss detailed density-functional theory studies aimed at putting our understanding of water-solid interfaces, specifically water-metal interfaces, on a much firmer footing. In this paper, I attempt to answer some key questions: Where do isolated water monomers adsorb on flat metal surfaces? How do water monomers diffuse across metal surfaces? How do water dimers adsorb and diffuse across metal surfaces? What factors control the structure and stability of water bilayers on metal surfaces? (orig.) (orig.)

Michaelides, A. [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin (Germany)

2006-12-15

162

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-09-12

163

Internal displacement in eastern Burma  

Directory of Open Access Journals (Sweden)

Full Text Available The history of post-independent Burma is characterisedby numerous conflicts in this extraordinarily heterogeneous country. Since military rule began in 196 2 Burmahas witnessed gross human rights abuses andmassive displacement.

Heather Rae

2007-07-01

164

Crack embrittlement displacement fields  

Science.gov (United States)

When using precracked fracture toughness specimens to study liquid metal embrittlement is has been necessary to estimate the crack length and applied load as a function of time. These parameters are sometimes difficult to obtain and accuracy is often questionable. Further, these data provide the basis for calculating crack growth rate (d a/d t) as a function of applied stress intensity factor KI. This paper presents an approach based on use of moiré interferometry in conjunction with fracture toughness specimens and acoustic emission techniques to study liquid mercury amalgam embrittlement of 6061-T 6 aluminum. Moiré interferometry provides a unique method for obtaining KI, at the crack tip, without requiring knowledge of crack length and load. This paper describes the approach and provides an evaluation based on test results.

Epstein, J. S.; Reuter, W. G.; Keiser, D. D.

165

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)

166

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)

167

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

168

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

169

Boiling water reactor stability analysis by stochastic transfer function identification  

International Nuclear Information System (INIS)

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

170

Medium characterization from interface-wave impedance and ellipticity using simultaneous displacement and pressure measurements.  

Science.gov (United States)

The interface-wave impedance and ellipticity are wave attributes that interrelate the full waveforms as observed in different components. For each of the fluid/elastic-solid interface waves, i.e., the pseudo-Rayleigh (pR) and Stoneley (St) waves, the impedance and ellipticity are found to have different functional dependencies on Young's modulus and Poisson's ratio. By combining the attributes in a cost function, unique and stable estimates of these parameters can be obtained, particularly when using the St wave. In a validation experiment, the impedance of the laser-excited pR wave is successfully extracted from simultaneous measurements of the normal particle displacement and the fluid pressure at a water/aluminum interface. The displacement is measured using a laser Doppler vibrometer (LDV) and the pressure with a needle hydrophone. Any LDV measurement is perturbed by refractive-index changes along the LDV beam once acoustic waves interfere with the beam. Using a model that accounts for these perturbations, an impedance decrease of 28% with respect to the plane wave impedance of the pR wave is predicted for the water/aluminum configuration. Although this deviation is different for the experimentally extracted impedance, there is excellent agreement between the observed and predicted pR waveforms in both the particle displacement and fluid pressure. PMID:21895072

van Dalen, K N; Drijkoningen, G G; Smeulders, D M J; Heller, H K J; Glorieux, C; Sarens, B; Verstraeten, B

2011-09-01

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

Functional polyelectrolyte multilayer membranes for water purification applications.  

Science.gov (United States)

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. PMID:23557682

Tripathi, Bijay P; Dubey, Nidhi C; Stamm, M

2013-05-15

173

Functional polyelectrolyte multilayer membranes for water purification applications  

International Nuclear Information System (INIS)

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

174

The nation's water resources: the Second National Water Assessment. Part III. Functional water uses. [1975 and projections to 1985 and 2000  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this report is to focus on the national perspectives regarding existing (1975) and future (1985 and 2000) requirements for water to meet offstream, instream, and flow management needs for eleven major functional categories.

1978-04-01

175

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

176

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

177

Examples of oil cavitation erosion in positive displacement pumps  

Science.gov (United States)

The effects of cavitation flow on piston type, positive displacement, hydraulic pumps are discussed. The operating principles of the pump and the components which are most subject to erosion effects are described. The mechanisms of cavitation phenomena are identified from photographic records. Curves are developed to show the solubility of air in water, oil-water emulsion, and industrial hydraulic oil.

Halat, J. A.; Ellis, G. O.

1974-01-01

178

A density functional study on iodine dioxide-water complexes  

Energy Technology Data Exchange (ETDEWEB)

The calculations of geometric structures, relative energies, vibrational frequencies, infrared intensities and binding energies of OIO-H{sub 2}O and OIO-2H{sub 2}O clusters have been performed using three DFT methods (B3LYP, B3P86 and B3PW91) at 6-311++G(3df, 3pd) basis set level. There are two kinds of interactions between iodine dioxide and water, one is the hydrogen bonding between the oxygen atom on iodine dioxide and the hydrogen atom on water, another is van der Waals interaction between I atom and the oxygen atom on H{sub 2}O. The analysis of the natural bond orbital (NBO) second-order interaction energies has also been employed to illuminate the binding energies and the stability of these OIO-nH{sub 2}O (n = 1, 2) complexes.

Wang Weigang [State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Haidian, Beijing 100080 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Ge Maofa [State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Haidian, Beijing 100080 (China)], E-mail: gemaofa@iccas.ac.cn; Wang Dianxun [State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Haidian, Beijing 100080 (China)

2006-09-29

179

Viscous Stabilization of 2D Drainage Displacements with Trapping  

CERN Document Server

We investigate the stabilization mechanisms due to viscous forces of the invasion front in drainage displacement in two dimensional porous media using a network simulator. We find that in horizontal displacement the capillary pressure difference between two different points along the front vary linearly as function of height separation in the direction of the displacement. We conclude that existing theory from percolation fails to describe our simulation results. We have also compared our results with some experimental data and find that the width of the front scales similar to gravitational stabilization.

Aker, E; Hansen, A; Aker, Eyvind; Maloy, Knut Jorgen; Hansen, Alex

2000-01-01

180

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)

 
 
 
 
181

Structure and function of carboxypeptidase A alpha in supercooled water.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The spectral and enzymatic characteristics of chromophoric derivatives of carboxypeptidase A alpha (EC 3.4.17.1) have been examined at subzero temperatures in supercooled water-in-oil emulsions. Substrate and temperature dependencies of enzyme kinetics indicated the existence of a solution-like enzyme phase that greatly extends the temperature range (greater than 60 degrees C) over which the activity of this enzyme can be measured. The emulsion spectra were virtually identical to those of sol...

Thompson, J. S.; Gehring, H.; Vallee, B. L.

1980-01-01

182

[A hockey player with displacement of the wrist].  

Science.gov (United States)

A 17-year-old boy had a painful left wrist after he fell while playing hockey. Examination showed volar displacement of the distal part of the ulna; the ulnar styloid prominence was absent. X-rays showed isolated volar displacement of the distal ulna. The diagnosis 'distal radio-ulnar joint dislocation' was made. Treatment consisted of K-wire fixation and an upper arm cast. He reached functional recovery. PMID:25027218

Pfaff, Aletta; de Klerk, Sietske D; Stallmann, Hein P

2014-01-01

183

Earthquake damage to underground facilities and earthquake related displacement fields  

International Nuclear Information System (INIS)

The potential seismic risk for an underground facility is considered in the evaluation of its location and design. The possible damage resulting from either large-scale displacements or high accelerations should be considered in evaluating potential sites of underground facilities. Scattered through the available literature are statements to the effect that below a few hundred meters shaking and damage in mines is less than at the surface; however, data for decreased damage underground have not been completely reported or explained. In order to assess the seismic risk for an underground facility, a data base was established and analyzed to evaluate the potential for seismic disturbance. Substantial damage to underground facilities is usually the result of displacements primarily along pre-existing faults and fractures, or at the surface entrance to these facilities. Evidence of this comes from both earthquakes as a function of depth is important in the evaluation of the hazard to underground facilities. To evaluate potential displacements due to seismic effects of block motions along pre-existing or induced fractures, the displacement fields surrounding two types of faults were investigated. Analytical models were used to determine relative displacements of shafts and near-surface displacement of large rock masses. Numerical methods were used to determine the displacement fields associated with pure strike-slip and vertical normal faults. Results are presented as displacements for various fault lengths as a function of depth and distance. This provides input to determine potential displacements in terms of depth and distance for underground facilities, important for assessing potential sites and design parameters

184

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

185

Multiplexed fiber optic displacement sensors  

International Nuclear Information System (INIS)

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

186

How well do testate amoebae transfer functions relate to high-resolution water-table records?  

Science.gov (United States)

Testate amoebae (TA) community composition records from peat cores are often used to infer past water-table conditions on peatland sites. However, one of the problems is that validation of water-table depths used in such work typically comes from a one-off water-table measurement or a few measurements of water-table depth from the testate amoebae sample extraction point. Furthermore, one value of water-table depth is produced by the transfer function reconstruction, with sample-specific errors generated through a statistical resampling approach. However, we know that water tables fluctuate in peatlands and are dynamic. Traditional TA water-table data may not adequately capture a mean value from a site, and may not account for water-table dynamics (e.g. seasonal or annual variability) that could influence the TA community composition. We analysed automatically logged (at least hourly, mainly 15-min) peatland water-table data from 72 different dipwells located across northern Sweden, Wales and the Pennine region of England. Each location had not been subject to recent management intervention. A suite of characteristics of water-table dynamics for each point were determined. At each point surface samples were extracted and the TA community composition was determined. Our results show that estimated water-table depth based on the TA community transfer functions poorly represents the real mean or median water tables for the study sites. The TA approach does, however, generally identify sites that have water tables that are closer to the surface for a greater proportion of the year compared to sites with deeper water tables for large proportions of the year. However, the traditional TA approach does not differentiate between sites with similar mean (or median) water-table depths yet which have quite different water table variability (e.g. interquartile range). We suggest some ways of improving water-table metrics for use in Holocene peatland hydrology reconstructions.

Holden, Joseph; Swindles, Graeme; Raby, Cassandra; Blundell, Antony

2014-05-01

187

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

Science.gov (United States)

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

O'Reilly, Andrew M.

2004-01-01

188

Structural Waters Define a Functional Channel Mediating Activation of the GPCR, rhodopsin  

Energy Technology Data Exchange (ETDEWEB)

Structural water molecules may act as prosthetic groups indispensable for proper protein function. In the case of allosteric activation of G protein-coupled receptors (GPCRs), water likely imparts structural plasticity required for agonist-induced signal transmission. Inspection of structures of GPCR superfamily members reveals the presence of conserved embedded water molecules likely important to GPCR function. Coupling radiolytic hydroxyl radical labeling with rapid H2O18 solvent mixing, we observed no exchange of these structural waters with bulk solvent in either ground state or for the Meta II or opsin states. However, the radiolysis approach permitted labeling of selected side chain residues within the transmembrane helices and revealed activation-induced changes in local structural constraints likely mediated by dynamics of both water and protein. These results suggest both a possible general mechanism for water-dependent communication in family A GPCRs based on structural conservation, and a strategy for probing membrane protein structure.

Angel, T.; Gupta, S; Jastrzebska, B; Palczewski, K; Chance, M

2009-01-01

189

[Functional load tests for the investigation of the kidneys and water-electrolyte metabolism].  

Science.gov (United States)

The paper deals with the application of functional load tests to assess the renal function and water-salt metabolism in human subjects during spaceflight simulating experiments and in cosmonauts in orbit and in the course of postflight recovery. The tests gave insight into mechanisms of the osmotic and volumetric regulation systems and enabled the development upon this knowledge of countermeasures to correct shifts in water-salt homeostasis. PMID:23789381

Grigor'ev, A I; Noskov, V B

2013-01-01

190

Dispersive effects of transverse magnet displacements in rolled arc achromats  

International Nuclear Information System (INIS)

The effect of transverse displacements of combined function magnets is investigated where the disperion in not matched due to roll. This dispersion function is perturbed by displacement of combined function magnets either singly or coherently. In the latter case the effect of a systematic (or DC) offset of magnets is examined. This type of error can occur due to systematics in the placement or the readout of Beam Position Monitors or equivalently by correcting the orbit of a beam of the wrong momentum with respect to the Arc magnet excitation. 5 refs., 18 figs

191

Displacement and difference in Lubumbashi  

Directory of Open Access Journals (Sweden)

Full Text Available Signs on the outskirts of the second largest city in the Democratic Republic of Congo (DRC welcome visitors to ‘the city of peace’. Lubumbashi has a reputation as a haven of tolerance in a violent nation but how are displaced people treated?

Aurelia Wa Kabwe-Segatti

2007-01-01

192

Retraining Displaced Workers. Policy Brief  

Science.gov (United States)

Robert LaLonde of the University of Chicago and Daniel Sullivan of the Federal Reserve Bank of Chicago suggest that retraining through our nation's community colleges is a way to reduce the skills gaps of at least some of these displaced workers and increase their reemployment earnings. Although workers may still experience significant earnings…

LaLonde, Robert; Sullivan, Daniel

2010-01-01

193

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

Science.gov (United States)

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

Wang, Wenhan; Shen, Yanqing; Wang, Xiaoou; Zhou, Zhongxiang; Fei, Weidong

2014-04-01

194

Water Mediated Ligand Functional Group Cooperativity: The Contribution of a Methyl Group to Binding Affinity is Enhanced by a COO? Group Through Changes in the Structure and Thermo dynamics of the Hydration Waters of Ligand-Thermolysin Complexes  

Science.gov (United States)

Ligand functional groups can modulate the contributions of one another to the ligand-protein binding thermodynamics, producing either positive or negative cooperativity. Data presented for four thermolysin phosphonamidate inhibitors demonstrate that the differential binding free energy and enthalpy caused by replacement of a H with a Me group, which binds in the well-hydrated S2? pocket, are more favorable in presence of a ligand carboxylate. The differential entropy is however less favorable. Dissection of these differential thermodynamic parameters, X-ray crystallography, and density-functional theory calculations suggest that these cooperativities are caused by variations in the thermodynamics of the complex hydration shell changes accompanying the H?Me replacement. Specifically, the COO? reduces both the enthalpic penalty and the entropic advantage of displacing water molecules from the S2? pocket, and causes a subsequent acquisition of a more enthalpically, less entropically, favorable water network. This study contributes to understanding the important role water plays in ligand-protein binding. PMID:22894131

Nasief, Nader N; Tan, Hongwei; Kong, Jing; Hangauer, David

2012-01-01

195

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

196

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

Energy Technology Data Exchange (ETDEWEB)

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

Chaudhari, Ajay [Department of Chemistry and Biochemistry, National Chung Cheng University, Ming-Hsiung, Chia Yi 62104, Taiwan (China)]. E-mail: ajaychau5@yahoo.com; Lee, S.-L. [Department of Chemistry and Biochemistry, National Chung Cheng University, Ming-Hsiung, Chia Yi 62104, Taiwan (China)]. E-mail: chesll@ccu.edu.tw

2005-04-04

197

Dynamic Measurement of Air Permeability as a Function of Water Content  

Science.gov (United States)

Determining the air permeability of a soil column as a function of water content is typically a tedious task because each measurement of permeability requires a constant water content over space and time. Between each individual measurement of permeability, the water content of the sample must be modified and allowed to equilibrate. A dynamic air permeability test is proposed that measures airflow rate, water content, and air pressure, while continually modifying the water content. Dry air is pumped into the inlet of an initially wet soil column, which slowly dries the soil within approximately 24-48 hours. A computer controlled gamma ray attenuation system measures and logs the water content along the length of the soil column over time. Hypodermic needles are inserted into the soil column and connected to pressure transducers, which measure the air pressure at multiple locations over time. An electronic flow meter logs the airflow rate over time. These measurements enable direct calculation of air permeability as a function of water content. Due to the large number of air pressure and water content measurements along the length of the soil column, the air permeability functions of individual layers can be distinguished from the remainder of the soil core. Because all measurements are computer controlled and logged, the system is completely autonomous.

Crenshaw, A. D.; Tyner, J. S.

2003-12-01

198

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

199

Modulation of morpho-functional characteristics of astrocytes using chemically-functionalized water-soluble single-walled carbon nanotubes  

Science.gov (United States)

In this thesis, I report the use of chemically functionalized water-soluble single-walled carbon nanotubes (ws-SWCNTs) for the modulation of morpho-functional characteristics of astrocytes. When added to the culturing medium, ws-SWCNTs were able to make astrocytes larger and stellate/mature, changes associated with the increase in glial fibrillary acidic protein immunoreactivity. Thus, ws-SWCNTs could have more beneficial effects at the injury site than previously thought; by affecting astrocytes, they could provide for a more comprehensive re-establishment of the brain computational power. Keywords: Carbon nanotubes, graft copolymers, astrocytes, glial fibrillary acidic protein.

Gottipati, Manoj K.

200

Force transmissibility versus displacement transmissibility  

Science.gov (United States)

It is well-known that when a single-degree-of-freedom (sdof) system is excited by a continuous motion of the foundation, the force transmissibility, relating the force transmitted to the foundation to the applied force, equals the displacement transmissibility. Recent developments in the generalization of the transmissibility to multiple-degree-of-freedom (mdof) systems have shown that similar simple and direct relations between both types of transmissibility do not appear naturally from the definitions, as happens in the sdof case. In this paper, the authors present their studies on the conditions under which it is possible to establish a relation between force transmissibility and displacement transmissibility for mdof systems. As far as the authors are aware, such a relation is not currently found in the literature, which is justified by being based on recent developments in the transmissibility concept for mdof systems. Indeed, it does not appear naturally, but the authors observed that the needed link is present when the displacement transmissibility is obtained between the same coordinates where the applied and reaction forces are considered in the force transmissibility case; this implies that the boundary conditions are not exactly the same and instead follow some rules. This work presents a formal derivation of the explicit relation between the force and displacement transmissibilities for mdof systems, and discusses its potential and limitations. The authors show that it is possible to obtain the displacement transmissibility from measured forces, and the force transmissibility from measured displacements, opening new perspectives, for example, in the identification of applied or transmitted forces. With this novel relation, it becomes possible, for example, to estimate the force transmissibility matrix with the structure off its supports, in free boundary conditions, and without measuring the forces. As far as force identification is concerned, this novel approach significantly decreases the computational effort when compared to conventional approaches, as it requires only local information of the sets of coordinates involved. Numerical simulations and experimental examples are presented and discussed, to illustrate the proposed developments.

Lage, Y. E.; Neves, M. M.; Maia, N. M. M.; Tcherniak, D.

2014-10-01

 
 
 
 
201

Estimating Hydrologic Processes from Subsurface Soil Displacements  

Science.gov (United States)

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

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

2012-12-01

202

Temporal trend and source apportionment of water pollution in different functional zones of Qiantang River, China.  

Science.gov (United States)

The increasingly serious river water pollution in developing countries poses great threat to environmental health and human welfare. The assignment of river function to specific uses, known as zoning, is a useful tool to reveal variations of water environmental adaptability to human impact. Therefore, characterizing the temporal trend and identifying responsible pollution sources in different functional zones could greatly improve our knowledge about human impacts on the river water environment. The aim of this study is to obtain a deeper understanding of temporal trends and sources of water pollution in different functional zones with a case study of the Qiantang River, China. Measurement data were obtained and pretreated for 13 variables from 41 monitoring sites in four categories of functional zones during the period 1996-2004. An exploratory approach, which combines smoothing and non-parametric statistical tests, was applied to characterize trends of four significant parameters (permanganate index, ammonia nitrogen, total cadmium and fluoride) accounting for differences among different functional zones identified by discriminant analysis. Aided by GIS, yearly pollution index (PI) for each monitoring site was further mapped to compare the within-group variations in temporal dynamics for different functional zones. Rotated principal component analysis and receptor model (absolute principle component score-multiple linear regression, APCS-MLR) revealed that potential pollution sources and their corresponding contributions varied among the four functional zones. Variations of APCS values for each site of one functional zone as well as their annual average values highlighted the uncertainties associated with cross space-time effects in source apportionment. All these results reinforce the notion that the concept of zoning should be taken seriously in water pollution control. Being applicable to other rivers, the framework of management-oriented source apportionment is thus believed to have potentials to offer new insights into water management and advance the source apportionment framework as an operational basis for national and local governments. PMID:21147494

Su, Shiliang; Li, Dan; Zhang, Qi; Xiao, Rui; Huang, Fang; Wu, Jiaping

2011-02-01

203

Functional brain studies with O-15 water and PET; Strategies and problems for approaching higher brain functions  

Energy Technology Data Exchange (ETDEWEB)

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

Momose, Toshimitsu; Rai, Tetsuji; Sasaki, Yasuto (Tokyo Univ. (Japan). Faculty of Medicine)

1994-04-01

204

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

205

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

206

Knowledge integration and displaced volume  

Science.gov (United States)

This study contrasted spontaneous and reflective knowledge integration instruction delivered using a computer learning environment to enhance understanding of displaced volume. Both forms of instruction provided animated experiments and required students to predict outcomes, observe results, and explain their ideas. In addition, the reflective instruction diagnosed specific inconsistencies in student reasoning and encouraged students to reflect on these dilemmas as well as to construct general principles. We distinguished the impact of instruction on students who believed scientific phenomena are governed by principles (cohesive beliefs) versus students who believed that science is a collection of unrelated ldquofactsrdquo (dissociated beliefs). Students typically held multiple models of displacement, using different explanations depending on the form of assessment. For example, we found that 17% of these middle school students made accurate predictions about displacement experiments prior to instruction and 25% could construct an accurate general principle. However, only 12% consistently used the same explanation across assessments. After instruction, students were more accurate and more consistent: over 50% accurately predicted experimental outcomes, 79% gave an accurate general principle, and about 40% gave consistent responses. We found no advantages for enhanced animations over straightforward animated experiments. The reflective integration instruction led to more substantial long-term changes in student understanding than did spontaneous integration instruction. Furthermore, on a delayed posttest we found that students with cohesive beliefs not only sustained their understanding of displaced volume, but, when exposed to reflective integration instruction, actually continued to construct more predictive views following instruction. In contrast, students with dissociated beliefs made no long-term progress independent of the form of instruction.

Linn, Marcia; Eylon, Bat-Sheva

2006-12-07

207

Repeated displacement in eastern DRC  

Directory of Open Access Journals (Sweden)

Full Text Available For the vast majority of those affected by conflict, displacementis often seen as the only option in an attempt to find safety. Theprovision of some basic assistance in places to which people fleemakes this process slightly easier but in the absence of state-ledprotection, multiple displacement has become a defining feature ofthe Kivu conflict. This has implications for both the humanitarian andthe development response.

Fran Beytrison

2013-05-01

208

A displacement amplifier using mechanical demodulation  

Science.gov (United States)

Piezoelectric ceramics can provide electromechanical transduction with high stresses but low displacements. To obtain larger displacements, several mechanical amplifying structures have been used. High alternating displacements can be obtained using resonant structures. We propose a displacement amplifier based on a mechanical rectifier, able to take advantage of the high displacements of resonant structures, and capable of obtaining a continuous displacement. A prototype composed of a Langevin resonator coupled to a mass-spring-damper system, acting as the rectifier, was constructed. Interferometric measurements on the proposed mechanical demodulator were carried out, validating the principle of operation. The possible applications are in the field of fast valves and micrometric positioning.

Carotenuto, Riccardo; Iula, Antonio; Pappalardo, Massimo; Lamberti, Nicola

1998-11-01

209

Metagenomic analysis reveals significant changes of microbial compositions and protective functions during drinking water treatment  

Science.gov (United States)

The metagenomic approach was applied to characterize variations of microbial structure and functions in raw (RW) and treated water (TW) in a drinking water treatment plant (DWTP) at Pearl River Delta, China. Microbial structure was significantly influenced by the treatment processes, shifting from Gammaproteobacteria and Betaproteobacteria in RW to Alphaproteobacteria in TW. Further functional analysis indicated the basic metabolic functions of microorganisms in TW did not vary considerably. However, protective functions, i.e. glutathione synthesis genes in `oxidative stress' and `detoxification' subsystems, significantly increased, revealing the surviving bacteria may have higher chlorine resistance. Similar results were also found in glutathione metabolism pathway, which identified the major reaction for glutathione synthesis and supported more genes for glutathione metabolism existed in TW. This metagenomic study largely enhanced our knowledge about the influences of treatment processes, especially chlorination, on bacterial community structure and protective functions (e.g. glutathione metabolism) in ecosystems of DWTPs.

Chao, Yuanqing; Ma, Liping; Yang, Ying; Ju, Feng; Zhang, Xu-Xiang; Wu, Wei-Min; Zhang, Tong

2013-12-01

210

Short-time fluctuations of displacements and work  

CERN Document Server

A recent theorem giving the initial behavior of very short-time fluctuations of particle displacements in classical many-body systems is discussed. It has applications to equilibrium and non-equilibrium systems, one of which is a series expansion of the distribution of work fluctuations around a Gaussian function. To determine the time-scale at which this series expansion is valid, we present preliminary numerical results for a Lennard-Jones fluid. These results suggest that the series expansion converges up to time scales on the order of a picosecond, below which a simple Gaussian function for the distribution of the displacements can be used.

Van Zon, R; Cohen, E G D; Zon, Ramses van

2006-01-01

211

Functional Abilities as a Predictor of Specific Motor Skills of Young Water Polo Players  

Science.gov (United States)

The purpose of this study was to assess the influence of functional abilities on specificmotor skills. A total number of 92 male water polo players (age 12±0.5 years, body height 156.96±22.3 cm, body weight 51.02±33.18 kg) with at least two years’ experience, were enrolled in the study. The investigation protocol consisted of standardized anthropometric measurements, estimation of maximum oxygen uptake, determination of the lung function values, specific swim tests and swim tests with a ball. The factor analysis was used for the estimation of the structure of specific motor skills. The influence of functional abilities on specific motor skills was estimated by regression analysis. Out of 15 correlations in total between the variables of space of functional abilities of water polo players, 6 were significant at the level of 95% (between the variables of aerobic power and lung function) and all of the correlations (15) between the variables of specific motor skills in water polo players were significant at the 99% level. Only one principal component, the General factor of specific motor skills in water polo (GFSWP) was obtained by way of factorization of the tests of specific motor skills, so the GFSWP represents the latent space of specific motor skills as a criterion. The regression analysis showed that functional abilities (as group predictors) (p= 0.00) and forced expiratory volume in 1 second (as a separate variable) have a significant influence on GFSWP (the criterion). The results of the study pointed out the impact of functional abilities on specific motor skills of selected young water polo players. This may be important for the selection and effective coaching in the early period of training and can affect the development of more appropriate and specific training programmes for optimal physical fitness preparation in young water polo players. PMID:23486729

Aleksandrovic, Marko; Radovanovic, Dragan; Okicic, Tomislav; Madic, Dejan; Georgiev, Georgi

2011-01-01

212

Quantum Monte Carlo benchmark of exchange-correlation functionals for bulk water  

Energy Technology Data Exchange (ETDEWEB)

The accurate description of the thermodynamic and dynamical properties of liquid water from first-principles is a very important challenge to the theoretical community. This represents not only a critical test of the predictive capabilities of first-principles methods, but it will also shed light into the microscopic properties of such an important substance. Density Functional Theory, the main workhorse in the field of first-principles methods, has been so far unable to properly describe water and its unusual properties in the liquid state. With the recent introduction of exact exchange and an improved description of dispersion interaction, the possibility of an accurate description of the liquid is finally within reach. Unfortunately, there is still no way to systematically improve exchange-correlation functionals and the number of available functionals is very large. In this article we use highly accurate quantum Monte Carlo calculations to benchmark a selection of exchange-correlation functionals typically used in Density Functional Theory simulations of bulk water. This allows us to test the predictive capabilities of these functionals in water, giving us a way not only to choose optimal functionals for first-principles simulations, but also giving us a route for the optimization of the functionals for the system at hand. We compare and contrast the importance of different features of functionals, including the hybrid component, the vdW component, and their importance within different aspects of the PES. In addition, we test a recently introduce scheme that combines Density Functional Theory with Coupled Cluster Calculations through a Many-Body expansion of the energy, in order to correct the inaccuracies in the description of short range interactions in the liquid.

Morales, Miguel A [Lawrence Livermore National Laboratory (LLNL); Gergely, John [University of Illinois, Urbana-Champaign; McMinis, Jeremy [Lawrence Livermore National Laboratory (LLNL); McMahon, Jeffrey [University of Illinois, Urbana-Champaign; Kim, Jeongnim [ORNL; Ceperley, David M. [University of Illinois, Urbana-Champaign

2014-01-01

213

Artificial Neural Network for Displacement Vectors Determination  

Directory of Open Access Journals (Sweden)

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

P. Bohmann

1997-09-01

214

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

Science.gov (United States)

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

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

2014-05-01

215

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

216

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

217

Displacement corrections used in absorbed dose determination  

International Nuclear Information System (INIS)

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

218

Water quality assessment of the Li Canal using a functional fuzzy synthetic evaluation model.  

Science.gov (United States)

Through introducing functional data analysis (FDA) theory into the conventional fuzzy synthetic evaluation (FSE) method, the functional fuzzy synthetic evaluation (FFSE) model is established. FFSE keeps the property of the conventional FSE that the fuzziness in the water quality condition can be suitably measured. Furthermore, compared with FSE, FFSE has the following advantages: (1) FFSE requires fewer conditions for observation, for example, pollutants can be monitored at different times, and missing data is accepted; (2) the dynamic variation of the water quality condition can be represented more comprehensively and intuitively. The procedure of FFSE is discussed and the water quality of the Li Canal in 2012 is evaluated as an illustration. The synthetic classification of the Li Canal is "II" in January, February and July, and "I" in other months, which can satisfy the requirement of the Chinese South-to-North Water Diversion Project. PMID:24835844

Feng, Yan; Ling, Liu

2014-07-01

219

Two exchange-correlation functionals compared for first-principles liquid water  

CERN Document Server

The first-principles description of liquid water using ab initio molecular dynamics (AIMD) based on Density Functional theory (DFT) has recently been found to require long equilibration times, giving too low diffusivities and a clear over-structuring of the liquid. In the light of these findings we compare here the room-temperature description offered by two different exchange correlation functionals: BLYP, the most popular for liquid water so far, and RPBE, a revision of the widely used PBE. We find for RPBE a less structured liquid with radial distribution functions closer to the experimental ones than the ones of BLYP. The diffusivity obtained with RPBE for heavy water is still 20% lower than the corresponding experimental value, but it represents a substantial improvement on the BLYP value, one order of magnitude lower than experiment. These characteristics and the hydrogen-bond (HB) network imperfection point to an effective temperature ~3% lower than the actual simulation temperature for the RPBE liquid...

Fernández-Serra, M V; Artacho, Emilio

2004-01-01

220

Water clusters to nanodrops: a tight-binding density functional study.  

Science.gov (United States)

We predict structures and energies of water clusters containing up to 100 waters with tight-binding density functional theory (DFTB). A per-hydrogen-bond energy correction is found to correct for systematic errors in the DFTB cluster energies. We compare the DFTB structures and energies to density functional theory (DFT) calculations and to the most accurate wave function theoretical (WFT) values available (ranging from coupled-cluster theory to second-order perturbation theory). After including the simple hydrogen bond correction, we achieve a root-mean-square difference of less than one kcal mol(-1) with the best estimates. As DFTB optimizations are orders of magnitude faster than DFT or canonical MP2, it is apparent that DFTB is a very practical method for calculating large water cluster structures and, with the hydrogen bond correction, also energies. PMID:23247323

Miró, Pere; Cramer, Christopher J

2013-02-14

 
 
 
 
221

The body stability in water and hand coordination of disabled swimmers function class swimming in freestyle  

Digital Repository Infrastructure Vision for European Research (DRIVER)

One of the main features of motory is coordination. In order to understand the hand coordination of disabled swimmers swimming in freestyle better, it’s vital to asses their body stability in water. The goal of the research is to measure the body stability in water and hand coordination of disabled swimmers function class swimming in freestyle. 6 disabled swimmers took part in the research. They were filmed from the front and from the side using an underwater filming system that ...

Gilaitiene?, Dovile?

2005-01-01

222

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

DEFF Research Database (Denmark)

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

Karunarathna, Anurudda Kumara; MØldrup, Per

2010-01-01

223

Dynamics of stable viscous displacement in porous media  

CERN Document Server

We investigate the stabilization mechanisms of the invasion front in two-dimensional drainage displacement in porous media by using a network simulator. We focus on the process when the front stabilizes due the viscous forces in the liquids. Especially, we study the variation of the capillary pressure along the front. We find that the capillary pressure difference between two different points along the front vary linearly as function of height separation in the direction of the displacement. Our result is inconsistent with earlier predictions for viscous stabilization when using percolation theory. Instead the behavior of the capillary pressure difference is found to be similar to what is known when gravity stabilizes the front. We also discuss the fluctuations in the capillary pressures between two different points along the front as function of injection rate. Our results are based on a network simulator modeling two phase drainage displacement on a two-dimensional lattice of tubes. We also compare some of ...

Aker, E; Hansen, A; Aker, Eyvind; Maloy, Knut Jorgen; Hansen, Alex

2000-01-01

224

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

225

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

Science.gov (United States)

The International Space Station (ISS) currently provides potable water dispensing for rehydrating crewmembers food and drinking packages with one system located in the United States On-orbit Segment (USOS) and one system in the Russian Segment. The USOS Potable Water Dispenser (PWD) was delivered to ISS on ULF2, Shuttle Mission STS-126, and was subsequently activated in November 2008. The PWD activation on ISS is capable of supporting an ISS crew of six but nominally supplies only half the crew. The PWD is designed to provide incremental quantities of hot and ambient temperature potable water to US style food packages. PWD receives iodinated water from the US Laboratory Fuel Cell Water Bus, which is fed 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 liters of hot water (65 to 93oC) every thirty minutes. This quantity supports three to four crewmembers to rehydrate their food and beverages from this location during a single meal. The unit is designed to remain functional for up to ten years with replacement of limited life items such as filters. To date, the PWD on-orbit performance has been acceptable. Since activation of the PWD, there have been several differences between on-orbit functionality and expected performance of hardware design. The comparison of on-orbit functionality to performance of hardware design is outlined for the following key areas: microbiology, PWD to food package water leakage, no-dispense scenarios, under-dispense scenarios, and crewmember feedback on actual on-orbit use.

Toon, Katherine P.; Lovell, Randal W.

2009-01-01

226

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

227

Density functional theory study of the water dissociation on platinum surfaces: general trends.  

Science.gov (United States)

We report a comparative periodic density functional theory study of the reaction of water dissociation on five platinum surfaces, e.g., Pt(111) Pt(100), Pt(110), Pt(211), and Pt(321). These surfaces were chosen to study the surface structural effects in the reaction of water dissociation. It was found that water molecules adsorb stronger on surfaces presenting low coordinated atoms in the surface. In the cases of the stepped Pt(110) and kinked Pt(321) surfaces, the activation energy barriers are smaller than the adsorption energies for the water molecule on the corresponding surfaces. Therefore, the calculations suggest that the dissociation reaction will take place preferentially at corner or edge sites on platinum particles with the (110) orientation. The inclusion of the results obtained in this work in previous derived BEP relationships confirms that the adsorption energy of the reaction products arises as the most appropriate descriptor for water dissociation on transition metal surfaces. PMID:24547954

Fajín, José L C; D S Cordeiro, M Natália; Gomes, José R B

2014-08-01

228

Vascular functioning and the water balance of ripening kiwifruit (Actinidia chinensis) berries.  

Science.gov (United States)

Indirect evidence suggests that water supply to fleshy fruits during the final stages of development occurs through the phloem, with the xylem providing little water, or acting as a pathway for water loss back to the plant. This inference was tested by examining the water balance and vascular functioning of ripening kiwifruit berries (Actinidia chinensis var. chinensis 'Hort16A') exhibiting a pre-harvest 'shrivel' disorder in California, and normal development in New Zealand. Dye labelling and mass balance experiments indicated that the xylem and phloem were both functional and contributed approximately equally to the fruit water supply during this stage of development. The modelled fruit water balance was dominated by transpiration, with net water loss under high vapour pressure deficit (D(a)) conditions in California, but a net gain under cooler New Zealand conditions. Direct measurement of pedicel sap flow under controlled conditions confirmed inward flows in both the phloem and xylem under conditions of both low and high D(a). Phloem flows were required for growth, with gradual recovery after a step increase in D(a). Xylem flows alone were unable to support growth, but did supply transpiration and were responsive to D(a)-induced pressure fluctuations. The results suggest that the shrivel disorder was a consequence of a high fruit transpiration rate, and that the perception of complete loss or reversal of inward xylem flows in ripening fruits should be re-examined. PMID:22155631

Clearwater, Michael J; Luo, Zhiwei; Ong, Sam Eng Chye; Blattmann, Peter; Thorp, T Grant

2012-03-01

229

The 'wet mind': water and functional neuroimaging  

Energy Technology Data Exchange (ETDEWEB)

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

Le Bihan, Denis [NeuroSpin, Batiment 145, CEA Saclay, 91191 Gif-sur-Yvette (France); Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto (Japan)

2007-04-07

230

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

231

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

232

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

Science.gov (United States)

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

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

2013-06-25

233

CHLORINATION BY-PRODUCTS IN DRINKING WATER AND MENSTRUAL CYCLE FUNCTION  

Science.gov (United States)

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

234

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

235

Dielectric permittivity enhancement in hydroxyl functionalized polyolefins via cooperative interactions with water  

Science.gov (United States)

Recent experiments have shown that polypropylene (PP) with a small fraction of hydroxyl (-OH) side groups displays a two-fold increase in the dielectric permittivity. It has been suggested that both the -OH groups and trapped water molecules may contribute to the dielectric constant increase. In this first principles computational study, using short polyolefin chains as models of PP, we shed light on the role played by -OH functional groups and the trapped moisture. Our results reveal that the trapped water molecules will inevitably accompany -OH incorporation (due to hydrogen bonding) and that both the -OH groups and water molecules will contribute cooperatively to the increase of the PP dielectric constant. These findings also provide insights into the effects of moisture on other molecularly functionalized materials systems.

Wang, C. C.; Pilania, G.; Ramprasad, R.; Agarwal, Manish; Misra, Mayank; Kumar, Sanat; Yuan, Xuepei; Mike Chung, T. C.

2013-04-01

236

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

237

Stress-intensity factors and crack-opening displacements for round compact specimens  

Science.gov (United States)

An improved method of boundary collocation based on the complex variable analysis of Muskhelishvili (1953) is applied to the two-dimensional stress analysis of round compact specimens with pin-loaded holes. Stress intensity factors and crack opening displacements are calculated for various round compact specimens as a function of crack-length-to-specimen-width ratios. A wide-range equation for the stress intensity factors and equations for crack-surface displacements and load-point displacements are developed.

Newman, J. C., Jr.

1981-01-01

238

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

Energy Technology Data Exchange (ETDEWEB)

The essential trace metal copper has been identified as a pollutant of concern by the Environmental Protection Agency (EPA) because of its widespread occurrence in the environment, often being found in concentrations capable of causing problems in organisms in that ecosystem. In this work, three different nanoporous sorbents containing chelating diamine functionalities were evaluated for Cu2+ adsorption in natural waters; these sorbents are ethylenediamine functionalized self-assembled monolayers on mesoporous supports (EDA-SAMMS®, SAMMS is a registered trademark of Steward Advanced Materials), ethylenediamine functionalized activated carbon (AC-CH2-EDA), and 1,10-Phenanthroline functionalized mesoporous carbon (Phen-FMC). The pH dependence of Cu2+ sorption and the Cu2+ sorption capacities of sorbents were determined. The Cu2+ adsorption rates and metal ion selectivity of these sorbents were compared to those of commercial sorbents (Chelex-100 ion exchange resin and Darco KB-B activated carbon). All three chelating diamine sorbents showed the excellent Cu2+ removal (~ 95-99%) from river water and sea water over the pH range of 6.0-8.0. Even under acidic conditions (e.g. pH of 3), AC-CH2-EDA and Phen-FMC were able to remove approximately ~49-58% of Cu2+ in sea water. EDA-SAMMS and AC-CH2-EDA demonstrated rapid Cu2+ sorption kinetics (reaching equilibrium within 5 min) and large adsorption capacities (26 and 17 mg Cu/g sorbent, respectively) in sea water. They also showed good selectivity for Cu2+ over other metal ions (e.g. Ca2+, Fe2+, Ni2+, and Zn2+) in sea water.

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

2010-04-13

239

Approximate functions for the fast computation of the thermodynamic properties of heavy water  

International Nuclear Information System (INIS)

A set of some approximate functions derived for the fast computation of the thermodynamic properties of heavy water at saturation, in subcooled liquid and superheated vapor states is presented. To derive these functions, the data given in the steam tables by Hill et al. (1981) were accurately and successfully fitted with curves by using the least-squares method. Specific volume (or density), specific enthalpy, specific entropy, constant-pressure specific heat and temperature at saturation were approximated by a number of piecewise continuous functions of pressure whereas pressure at saturation was approximated by a piecewise continuous function of temperature for heavy water. Density in subcooled liquid state, specific volume in superheated vapor state, specific enthalpy, specific entropy and constant-pressure specific heat in both of these states were also approximated as piecewise continuous functions of pressure and temperature for heavy water. The correlations presented in this study can be used in the two-phase thermalhydraulic system analysis of CANDU-PHW reactor with confidence. (orig.)

240

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

 
 
 
 
241

Avoiding condylar displacement after intraoral vertical ramus osteotomy.  

Science.gov (United States)

The intraoral vertical osteotomy is a versatile and simple technique usually applied to correct mandibular prognathism. Its greatest advantages include ease of performance and minimum neurosensory disturbances, whereas maxillomandibular fixation is pointed as its major disadvantage. Another important concern about this technique is condylar displacement, which may lead to temporomandibular dysfunction. Technical notes to avoid condylar luxation are discussed after 15 years of experience using this osteotomy as the technique of choice to correct mandibular prognathism. Three similar cases are presented, where 1 condyle was displaced from the glenoid fossa, resulting in mandibular deviation during function in patients requiring small mandibular setback. PMID:20485061

Ritto, Fabio; Parente, Eduardo; da Silveira, Henrique Martins; Medeiros, Paulo José; de Moraes, Márcio

2010-05-01

242

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

243

Molecular Dynamics Simulation of Displacement Cascades in Zircon  

International Nuclear Information System (INIS)

Molecular dynamics simulation with Buckingham and Morse empirical potentials has been used to study radiation damage in zircon (ZrSiO4) at 300 K, where an uranium atom was used as the primary knock-on and O-O RDF functions have been drawn. The results of the MD simulations show that the maximal number of displaced atoms is closely equal to 100 for t?0.27 ps, and the end number of displaced atoms is closely equal to 70 for t>1 ps

244

Steering of H- ion beamlet by aperture displacement  

International Nuclear Information System (INIS)

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

245

Effect of Carboxylic Functional Group Functionalized on Carbon Nanotubes Surface on the Removal of Lead from Water  

Science.gov (United States)

The adsorption mechanism of the removal of lead from water by using carboxylic functional group (COOH) functionalized on the surface of carbon nanotubes was investigated. Four independent variables including pH, CNTs dosage, contact time, and agitation speed were carried out to determine the influence of these parameters on the adsorption capacity of the lead from water. The morphology of the synthesized multiwall carbon nanotubes (MWCNTs) was characterized by using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) in order to measure the diameter and the length of the CNTs. The diameters of the carbon nanotubes were varied from 20 to 40?nm with average diameter at 24?nm and 10 micrometer in length. Results of the study showed that 100% of lead was removed by using COOH-MCNTs at pH 7, 150?rpm, and 2 hours. These high removal efficiencies were likely attributed to the strong affinity of lead to the physical and chemical properties of the CNTs. The adsorption isotherms plots were well fitted with experimental data. PMID:21350599

Atieh, Muataz Ali; Bakather, Omer Yehya; Al-Tawbini, Bassam; Bukhari, Alaadin A.; Abuilaiwi, Faraj Ahmad; Fettouhi, Mohamed B.

2010-01-01

246

Fabrication of amine-functionalized magnetite nanoparticles for water treatment processes  

International Nuclear Information System (INIS)

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

247

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

248

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

249

General Displaced SU (1,1) number states-revisited  

CERN Document Server

The most general displaced number states, based on the bosonic and an irreducible representation(IREP) of the Lie algebra symmetry of su(1, 1) and associated to 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...

Dehghani, A

2014-01-01

250

Analysis of optical interferometric displacement detection in nanoelectromechanical systems  

International Nuclear Information System (INIS)

Optical interferometry has found recent use in the detection of nanometer scale displacements of nanoelectromechanical systems (NEMS). At the reduced length scale of NEMS, these measurements are strongly affected by the diffraction of light. Here, we present a rigorous numerical model of optical interferometric displacement detection in NEMS. Our model combines finite element methods with Fourier optics to determine the electromagnetic field in the near-field region of the NEMS and to propagate this field to a detector in the far field. The noise analysis based upon this model allows us to elucidate the displacement sensitivity limits of optical interferometry as a function of device dimensions as well as important optical parameters. Our results may provide benefits for the design of next generation, improved optical NEMS

251

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

252

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

253

Displacement measurement with intracavity interferometry  

Science.gov (United States)

We present a measuring technique for displacement and position sensing over a limited range with detection of standingwave pattern inside of a passive Fabry-Perot cavity. The concept considers locking of the laser optical frequency and the length of the Fabry-Perot cavity in resonance. Fixing the length of the cavity to e.g. a highly stable mechanical reference allows to stabilize wavelength of the laser in air and thus to eliminate especially the faster fluctuations of refractive index of air due to air flow and inhomogeneities. Sensing of the interference maxima and minima within the cavity along the beam axis has been tested and proven with a low loss photoresistive photodetector based on a thin polycrystalline silicon layer. Reduction of losses was achieved thanks to a design as an optimized set of interference layers acting as an antireflection coating. The principle is demonstrated on an experimental setup.

Lazar, Josef; Holá, Miroslava; Fejfar, Antonín.; Stuchlík, Ji?í; Ko?ka, Jan; Oulehla, Jind?ich; ?íp, Ond?ej

2014-05-01

254

Polyimidazoles via aromatic nucleophilic displacement  

Science.gov (United States)

Polyimidazoles (PI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl) imidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The reactions are carried out in polar aprotic solvents such as N,N-dimethyl acetamide, sulfolane, N-methylpyrrolidinone, dimethylsulfoxide, or diphenylsulfone using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. The di(hydroxyphenyl) imidazole monomers are prepared by reacting an aromatic aldehyde with a dimethoxybenzil or by reacting an aromatic dialdehyde with a methoxybenzil in the presence of ammonium acetate. The di(methoxyphenyl) imidazole is subsequently treated with aqueous hydrobromic acid to give the di(hydroxphenyl) imidazole monomer. This synthetic route has provided high molecular weight PI of new chemical structure, is economically and synthetically more favorable than other routes, and allows for facile chemical structure variation due to the availability of a large variety of activated aromatic dihalides and dinitro compounds.

Connell, John W. (inventor); Hergenrother, Paul M. (inventor)

1992-01-01

255

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.

256

Density functional theory simulations of the structure, stability and dynamics of iron sulphide clusters in water.  

Science.gov (United States)

Density Functional Theory-based calculations have been employed to investigate the structure, stability and dynamics of iron sulphide clusters, FexSy (x, y ? 4), in water. Car-Parrinello molecular dynamics simulations of the building unit FeS in explicit water show that the iron is only four-coordinated, which indicates that the effect of sulphur is to significantly reduce the coordination shell of iron compared with the typical octahedral arrangement of hexa-aqua iron complexes in water. The molecular dynamics simulations of FexSy particles (x, y ? 2) in explicit water reveal that these clusters are highly unstable as they dissociate after a few picoseconds. The Gibbs free energies to form the FeS and Fe2S2 species have been evaluated in a simulated aqueous environment, using the mPW1B95 density functional theory level for the gas-phase component and the UAHF-CPCM solvation model for the hydration contribution, and the results indicate that while FeS is thermodynamically stable in aqueous solution, the formation of a Fe2S2 cluster is endergonic, and dissociation is preferred under natural water conditions. PMID:23407642

Haider, Saima; Di Tommaso, Devis; de Leeuw, Nora H

2013-03-28

257

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-10-29

258

Functionalization of graphene and grafting of temperature-responsive surfaces from graphene by ATRP “on water  

International Nuclear Information System (INIS)

Water-dispersible graphene with temperature-responsive surfaces has successfully been synthesized by grafting poly(N-isopropylacrylamide) (PNIPAM) from graphene via surface-initiated atom transfer radical polymerization (ATRP). First, graphene surfaces are functionalized with aminophenol groups by diazonium reaction on water. Subsequently, bromoisobutyrate groups are covalently attached to the phenol-functionalized graphene (G-OH) surface by esterification of 2-bromoisobutyrate with the hydroxyl groups, forming bromoisobutyrate-functionalized graphene (G-Br). Finally, PNIPAM is then grafted from G-Br via ATRP. Data from Raman spectroscopy, 1H NMR, and transmission electron microscopy (TEM) confirm that PNIPAM chains grow from graphene by ATRP. Thermogravimetric analysis shows that the amount of PNIPAM grown from the graphene increases with the increase of monomer ratios. TEM images also show that functionalized polymer structures (PNIPAM cluster or agglutination) on graphene sheets can be well tuned by controlled polymerization. The obtained graphene-PNIPAM (G-PNIPAM) composite has PNIPAM surface which is highly sensitive to the temperature change. This temperature-responsive and water-dispersible G-PNIPAM composite may find potential applications in environmental devices as well as controlled release drug delivery.

259

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

Science.gov (United States)

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

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

1999-01-01

260

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

Science.gov (United States)

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

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

2013-03-01

 
 
 
 
261

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.

262

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

263

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

264

Ecological character displacement caused by reproductive interference.  

Science.gov (United States)

We carried out a theoretical investigation of whether ecological character displacement can be caused by reproductive interference. Our model assumes that a quantitative character is associated with both resource use and species recognition, and that heterospecific mating incurs costs. The model shows that ecological character displacement can occur as a consequence of evolution of premating isolation; this conclusion is based on the premise that resource competition is less intense between species than within species and that the ecological character also contributes to premating isolation. When resource competition between species is intense, extinction of either species may occur by competitive exclusion before ecological character divergence. Some observational studies have shown that character displacement in body size is associated with not only resources use but also species recognition. We propose that body size displacement can occur as a consequence of evolution of premating isolation. Our results suggest that ecological character displacement results from reproductive character displacement. PMID:17448500

Konuma, Junji; Chiba, Satoshi

2007-07-21

265

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

266

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

267

Functional diversity changes of microbial communities along a soil aquifer for reclaimed water recharge.  

Science.gov (United States)

The physiochemical and functional diversity of soil-attached microorganisms was investigated using a stabilized laboratory-scale soil aquifer treatment (SAT) system. In this system, reclaimed water after ozonation was used as the feed water, and 60% dissolved organic carbon was removed by the unsaturated vadose layer in 0.8 days. Soil biomass (volatile solids, phospholipid extraction) and functional diversity significantly decreased from the unsaturated vadose layer to the saturated aquifer, where they maintained the same level. Using principal components analysis based on substrate utilization pattern, the vadose layer soil sample was clearly separated from the saturated layer samples. Exceptionally, the oxidation rates of esters remained stable during SAT, indicating the purification potential on certain recalcitrant organic compounds in the saturated aquifer given an adequate retention time. Correlation analysis revealed that organic carbon was the key limiting factor for microbial biomass and activity, especially for tyrosine-like aromatic proteins and soluble microbial byproduct-like materials. PMID:22126459

Zhang, Xue; Zhao, Xuan; Zhang, Meng

2012-04-01

268

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

Science.gov (United States)

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 of the global symptoms score, (ii) reduction of intensity to a level not interfering with everyday activities, (iii) specific efficacy on ulcer-like or dysmotility-like dyspepsia and (iv) esophageal or abdominal-associated symptoms. Statistical significance was reached for all three primary outcomes after the first 29 consecutive patients. Thermal water reduced the global symptom score, reduced intensity of symptoms to a level not interfering with everyday activity, but was unable to completely suppress all symptoms. A parallel effect emerged for ulcer-like and dyspepsia-like subgroups. The effect on heartburn and abdominal symptoms was not significant, suggesting a specific effect of the water on the gastric and duodenal wall. The Roma II criteria identify a natural kind of dyspepsia that improves with thermal water. Ulcer-like and dysmotility-like are not therapeutically distinguishable subgroups. Patients with dominant esophageal or abdominal symptoms should receive a different therapy. Sequential methods are very effective for the evaluation of traditional care practices and should be considered preliminary and integrative to randomized controlled trials in this context. PMID:17965771

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

2007-01-01

269

Spent Fuel Dissolution Rates as a Function of Burnup and Water Chemistry  

International Nuclear Information System (INIS)

Several months ago, a report called PNNL-11895, 'Spent Fuel Dissolution Rates as a Function of Burnup and Water Chemistry', by W. J. Gray dated June 1998 was mailed out. Unfortunately, an error was discovered in this document. The technetium (Tc) data in Figures 5 to 8, pages 21 to 24, are incorrect. Replacement figures, which show the corrected Tc data, are presented. No other data in the report was affected by this error

270

Density functional treatment of water-carbon dioxide van der Waals complex  

Energy Technology Data Exchange (ETDEWEB)

LCGTO-LSD and LCGTO-NLSD methods have been tested for the study of water-carbon dioxide weakly bound binary complex. Different local and nonlocal exchange-correlation energy functionals and many grid radial points have been used. Results show that both nonlocal corrections and a large number of radial points in the grid are mandatory for well reproducing then experimental data. 19 refs., 1 fig., 2 tabs.

Abashkin, Y.; Mele, F.; Russo, N.; Toscano, M. [Universita della Calabria, Arcavacata di Rende (Italy)

1994-12-31

271

Stabilization of phase inversion temperature nanoemulsions by surfactant displacement.  

Science.gov (United States)

Nanoemulsions are finding increasing utilization in the food and beverage industry to encapsulate and protect lipophilic functional components. Low-intensity methods, such as the phase inversion temperature (PIT) approach, are of particular interest for forming food-grade nanoemulsions because of their ease of formation and relatively low energy costs. Nevertheless, this type of emulsion tends to be highly unstable to droplet coalescence after preparation. In this study, we develop a potential solution to this problem using model water/surfactant (Brij 30, C(12)E(4))/oil (tetradecane) systems. The PIT and system morphology were determined by monitoring the temperature dependence of the electrical conductivity, turbidity, and microstructure of the emulsions. Nanoemulsions were formed by holding water/surfactant/oil mixtures at their PIT and then rapidly cooling them. The influence of storage temperature on emulsion stability was investigated, which indicated that the optimum temperature (13 degrees C) was about 27 degrees C lower than the PIT (approximately 40 degrees C). Higher storage temperatures resulted in an increase in droplet growth rate due to coalescence, while lower temperatures led to gelation. Nanoemulsions that were relatively stable to coalescence could be formed at ambient temperatures by adding either Tween 80 (0.2 wt %) or SDS (0.1 wt %) to displace the Brij 30 from the droplet surfaces. We propose that these surfactants increase nanoemulsion stability by changing the optimum curvature of the interfacial layer, as well as by increasing the repulsive interactions (steric or electrostatic) between the droplets. This study may lead to a novel approach to create stable nanoemulsion-based delivery systems that are suitable for utilization within the food industry. PMID:20476765

Rao, Jiajia; McClements, David Julian

2010-06-01

272

Adsorption of water vapor and carbon dioxide at carboxylic functional groups on the surface of coal  

Energy Technology Data Exchange (ETDEWEB)

The adsorption of water vapor and carbon dioxide at room temperature in relation to carboxylic functional groups on the surfaces of 20 different types of coal was examined. The carboxylic functional groups on the surface of coal may be considered the preferential sites of adsorption when compared with the other groups. The adsorption of water vapor and carbon dioxide was found to increase in proportion to the square root of the carboxyl group concentration, regardless of the partial pressure or the gas species. Assuming functional group adsorption sites to be present on the surfaces of hydrophobic matrices and adsorption to occur in a liquid-like closed packed state, the adsorption on coal was determined based on the carboxyl group concentration on the coal surface, the molecular cross section and the molecular weight of the adsorbate. The surface area did not depend on the type of adsorbate, as was observed for water vapor and carbon dioxide adsorption on coal. 30 refs., 7 figs., 3 tabs.

Nishino, J. [Ishikawajima-Harima Heavy Industries Co. Ltd., Yokohama (Japan). Environmental Process Development Department, Industrial Machine & Plant Development Center

2001-04-01

273

A functional cutin matrix is required for plant protection against water loss  

Science.gov (United States)

The plant cuticle, a cutin matrix embedded with and covered by wax, seals the aerial organ's surface to protect the plant against uncontrolled water loss. The cutin matrix is essential for the cuticle to function as a barrier to water loss. Recently, we identified from wild barley a drought supersensitive mutant, eibi1, which is caused by a defective cutin matrix as the result of the loss of function of HvABCG31, an ABCG full transporter. Here, we report that eibi1 epidermal cells contain lipid-like droplets, which are supposed to consist of cutin monomers that have not been transported out of the cells. The eibi1 cuticle is fragile due to a defective cutin matrix. The rice ortholog of the EIBI1 gene has a similar pattern of expression, young shoot but not flag leaf blade, as the barley gene. The model of the function of Eibi1 is discussed. The HvABCG31 full transporter functions in the export of cutin components and contributed to land plant colonization, hence also to terrestrial life evolution. PMID:22019635

Ma, Jian Feng; Li, Chao; Yamaji, Naoki; Nevo, Eviatar

2011-01-01

274

Comparison of Water Production Functions for Winter Wheat in Mashhad Region  

Directory of Open Access Journals (Sweden)

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

B. Ghahraman

2005-10-01

275

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

276

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

277

Study of Hydrogen Bonding in Small Water Clusters with Density Functional Theory Calculations  

Energy Technology Data Exchange (ETDEWEB)

The unique characteristics of hydrogen bonding have left our understanding of liquid water far from complete in terms of its structure and properties. In order to better describe the hydrogen bond in water, we seek to understand the electronic states which show sensitivity to hydrogen bonding. We investigate the structure of unoccupied valence states by performing X-ray Absorption calculations on water clusters using Density Functional Theory. For each water cluster, studying how valence electronic structure is perturbed by changes in the local hydrogen bonding environment facilitates our description of the hydrogen bond. Also in this framework, we move toward a depiction of local structures in liquid water by comparison to experimental X-ray absorption spectra. We find consistent localization along internal bonds in the electronic structures of pre- and post-edge states for single-donor species. In addition, we propose a molecular orbital bonding-antibonding picture to explain this directional localization from dimer calculations, and show that the pre- and post-edge spectral regions have a resulting relationship.

Wendlandt, Johanna; /Wisconsin U., Madison /SLAC, SSRL

2005-12-15

278

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

Science.gov (United States)

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

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

2001-01-01

279

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

280

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

 
 
 
 
281

Transit times of water particles in the vadose zone across catchment states and catchments functional units  

Science.gov (United States)

Understanding the water movement in the vadose zone and its associated transport of solutes are of major interest to reduce nutrient leaching, pollution transport or other risks to water quality. Soil physical models are widely used to asses such transport processes, while the site specific parameterization of these models remains challenging. Inverse modeling is a common method to adjust the soil physical parameters in a way that the observed water movement or soil water dynamics are reproduced by the simulation. We have shown that the pore water stable isotope concentration can serve as an additional fitting target to simulate the solute transport and water balance in the unsaturated zone. In the presented study, the Mualem- van Genuchten parameters for the Richards equation and diffusivity parameter for the convection-dispersion equation have been parameterized using the inverse model approach with Hydrus-1D for 46 experimental sites of different land use, topography, pedology and geology in the Attert basin in Luxembourg. With the best parameter set we simulated the transport of a conservative solute that was introduced via a pulse input at different points in time. Thus, the transit times in the upper 2 m of the soil for different catchment states could be inferred for each location. It has been shown that the time a particle needs to pass the -2 m depth plane highly varies from the systems state and the systems forcing during and after infiltration of that particle. Differences in transit times among the study sites within the Attert basin were investigated with regards to its governing factors to test the concept of functional units. The study shows the potential of pore water stable isotope concentration for residence times and transport analyses in the unsaturated zone leading to a better understanding of the time variable subsurface processes across the catchment.

Sprenger, Matthias; Weiler, Markus

2014-05-01

282

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

Energy Technology Data Exchange (ETDEWEB)

Several types of amino-functionalized mesoporous silica, including F5-SBA-15, F10-SBA-15, and F15-SBA-15 were prepared through co-condensation of tetraethoxysilane (TEOS) and (3-aminopropyl)triethoxysilane (APTES) in varying molar ratios (5 mol%, 10 mol%, and 15 mol%) via a hydrothermal process. The materials obtained were characterized by means of small-angle X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, N{sub 2} adsorption-desorption, Fourier transformed infrared spectra, and X-ray photoelectron spectroscopy. Increasing APTES molar ratios decreased the degree of orderliness of the functionalized mesoporous silica. Pure and amino-functionalized SBA-15 samples were employed as supports for the controlled release of water-insoluble drug emodin. Loading experiments showed that drug loading capacities mainly depended on the surface areas and pore diameters of the carriers. Controlled release profiles of emodin-loaded samples were studied in phosphate buffered saline (PBS, pH 7.4), and results indicated that the emodin release rate could be controlled by surface amino-functionalized carriers. Emodin loaded on functionalized mesoporous supports exhibited a lower release rate than that of loaded on pure SBA-15, emodin loaded on F10-SBA-15 showed the smallest release amount (71.74 wt%) after stirring in PBS for 60 h. Findings suggest that functionalized mesoporous SBA-15 is a promising carrier for achieving prolonged release time periods.

Xu Yunqiang; Wang Chunfeng [Shandong Provincial Key Laboratory of Fine Chemicals, School of Chemistry, Shandong Polytechnic University, Jinan 250353, Shandong (China); Zhou Guowei, E-mail: guoweizhou@hotmail.com [Shandong Provincial Key Laboratory of Fine Chemicals, School of Chemistry, Shandong Polytechnic University, Jinan 250353, Shandong (China); Wu Yue; Chen Jing [Shandong Provincial Key Laboratory of Fine Chemicals, School of Chemistry, Shandong Polytechnic University, Jinan 250353, Shandong (China)

2012-06-15

283

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

Science.gov (United States)

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

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

2012-06-01

284

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)

285

Effect of displacement on resistance and capacitance of polyaniline film  

Science.gov (United States)

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.

Khasan Sanginovich, Karimov; Muhammad Tariq, Saeed; Fazal, Ahmad Khalid; Syed, Abdul Moiz

2011-04-01

286

Intramolecular indicator displacement assay for anions: supramolecular sensor for glyphosate.  

Science.gov (United States)

One of the well-known strategies for anion sensing is an indicator (dye) displacement assay. However, the disadvantage of the dye displacement assays is the low sensitivity due to the excess of the dye used. To overcome this setback, we have developed an "Intramolecular Indicator Displacement Assay (IIDA)". The IIDAs comprise a receptor and a spacer with an attached anionic chromophore in a single-molecule assembly. In the resting state, the environment-sensitive anionic chromophore is bound by the receptor, while the anionic substrate competes for binding into the receptor. The photophysical properties of the dye exhibit change in fluorescence when displaced by anions, which results in cross-reactive response. To illustrate the concept, we have prepared IID sensors 1 and 2. Here, the characterization of sensors and microtiter arrays comprising the IIDA are reported. The microtiter array including IID sensors 1 and 2 is capable of recognizing biological phosphates in water. The utility of the IIDA approach is demonstrated on sensing of a phosphonate herbicide glyphosate and other biologically important anions such as pyrophosphate in the presence of interferent sodium chloride. PMID:25051138

Minami, Tsuyoshi; Liu, Yuanli; Akdeniz, Ali; Koutnik, Petr; Esipenko, Nina A; Nishiyabu, Ryuhei; Kubo, Yuji; Anzenbacher, Pavel

2014-08-13

287

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

288

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

Directory of Open Access Journals (Sweden)

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

289

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)

290

Hamiltonian displacement of bidisks inside cylinders  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Comment: The paper has a flaw in the construction. The correct theorem about displacing bidisks can be found in the paper of Fukaya, Oh, Ohta and Ono, `Displacement of polydisks and Lagrangian Floer theory', J. Symplectic Geom., 11(2013), 231-268

Hind, Richard

2009-01-01

291

BLOCK DISPLACEMENT METHOD FIELD DEMONSTRATION AND SPECIFICATIONS  

Science.gov (United States)

The Block Displacement technique has been developed as a remedial action method for isolating large tracks of ground contaminated by hazardous waste. The technique places a low permeability barrier around and under a large block of contaminated earth. The Block Displacement proce...

292

Is Maxwell's Displacement Current a Current?  

Science.gov (United States)

Discusses in detail the claim that certain well-known physics experiments demonstrate the magnetic field produced by Maxwell's displacement current. Addresses the question of whether the displacement current acts as a source of magnetic field in the same way as a current in a wire would. (Contains 12 references.) (WRM)

French, A. P.

2000-01-01

293

Displaceability and the mean Euler characteristic  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this note we show that the mean Euler characteristic of equivariant symplectic homology is an effective obstruction against the existence of displaceable exact contact embeddings. As an application we show that certain Brieskorn manifolds do not admit displaceable exact contact embeddings.

Frauenfelder, Urs; Schlenk, Felix; Koert, Otto

2011-01-01

294

Unusual renal displacement due to massive splenomegaly  

International Nuclear Information System (INIS)

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

295

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

296

Evaluation of thermal water in patients with functional dyspepsia and irritable bowel syndrome accompanying constipation  

Science.gov (United States)

AIM: To evaluate the efficacy of water supplementation treatment in patients with functional dyspepsia or irritable bowe syndrome (IBS) accompanying predominant constipation. METHODS: A total of 3?872 patients with functional dyspepsia and 3?609 patients with irritable bowel syndrome were enrolled in the study by 18 Italina thermal centres. Patients underwent a first cycle of thermal therapy for 21 d. A year later patients were re-evaluated at the same centre and received another cycle of thermal therapy. A questionnare to collect personal data on social and occupational status, family and pathological case history, life style, clinical records, utilisation of welfare and health structure and devices was administered to each patient at basal time and one year after each thermal treatment. Sixty patients with functional dyspepsia and 20 with IBS and 80 healthy controls received an evaluation of gastric output and oro-cecal transit time by breath test analysis. Breath test was performed at basal time and after water supplementaton therapies. Gastrointestinal symptoms were evaluated at the same time points. Breath samples were analyzed with a mass spectometer and a gascromatograph. Results were expressed as T1/2 and T-lag for octanoic acid breath test and as oro-cecal transit time for lactulose breath test. RESULTS: A significant reduction of prevalence of symptoms was observed at the end of the first and second cycles of thermal therapy in dyspeptic and IBS patients. The analysis of variance showed a real and persistant improvement of symptoms in all patients. After water supplementation for 3 wk a reduction of gastric output was observed in 49 (87.5%) of 56 dyspeptic patients. Both T1/2 and T-lag were significantly reduced after the therapy compared to basal values [91?±?12 (T1/2) and 53?±?11 (T-lag), Tables 1 and 2] with results of octanoic acid breath test similar to healthy subjects. After water supplementation for 3 wk oro-cecal transit time was shorter than that at the beginning of the study. CONCLUSION: Mineral water supplementation treatment for functional dyspepsia or conspipation accompanying IBS can improve gastric acid output and intestinal transit time. PMID:16688801

Gasbarrini, Giovanni; Candelli, Marcello; Graziosetto, Riccardo Giuseppe; Coccheri, Sergio; Iorio, Ferdinando Di; Nappi, Giuseppe

2006-01-01

297

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

298

Displacement-dispersive liquid-liquid microextraction based on solidification of floating organic drop of trace amounts of palladium in water and road dust samples prior to graphite furnace atomic absorption spectrometry determination.  

Science.gov (United States)

A new displacement-dispersive liquid-liquid microextraction method based on the solidification of floating organic drop was developed for separation and preconcentration of Pd(ll) in road dust and aqueous samples. This method involves two steps of dispersive liquid-liquid microextraction based on solidification. In Step 1, Cu ions react with diethyldithiocarbamate (DDTC) to form Cu-DDTC complex, which is extracted by dispersive liquid-liquid microextraction based on a solidification procedure using 1-undecanol (extraction solvent) and ethanol (dispersive solvent). In Step 2, the extracted complex is first dispersed using ethanol in a sample solution containing Pd ions, then a dispersive liquid-liquid microextraction based on a solidification procedure is performed creating an organic drop. In this step, Pd(ll) replaces Cu(ll) from the pre-extracted Cu-DDTC complex and goes into the extraction solvent phase. Finally, the Pd(ll)-containing drop is introduced into a graphite furnace using a microsyringe, and Pd(ll) is determined using atomic absorption spectrometry. Several factors that influence the extraction efficiency of Pd and its subsequent determination, such as extraction and dispersive solvent type and volume, pH of sample solution, centrifugation time, and concentration of DDTC, are optimized. PMID:24000764

Ghanbarian, Maryam; Afzali, Daryoush; Mostafavi, Ali; Fathirad, Fariba

2013-01-01

299

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

300

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

 
 
 
 
301

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

302

Visual techniques for the detection of water quality trends: Double-mass curves and cusum functions.  

Science.gov (United States)

There is a great need for quantitative techniques to assess changes in water quality related to progressive watershed land-use developments, water-related impoundments or to evaluate the impact of recent sanitation programs. In choosing a physically representative variate for the water quality of the run-off, both concentrations and fluxes of pollutants must be taken into account. The importance of the climatic seasonal and hydrological factors associated with unstable event-related contributions of point and non-point pollution sources of the pollutants has lead us to simultaneously study water-discharge and pollutant flux time-series. The mass-discharge time-series are, in practice, far from being ideal for the application of classical trend analysis: they are relatively short and inaccurate: their distribution, orginating from mixed parent populations is very often highly skewed; they show a high level of serial dependence and the seasonal effects represent a large percentage of the variance, concealing possible long-term trends. Faced with the poor structure of these series which prohibits the use of statistical tests, experiments have been carried out with progressive-regressive inertial techniques, which imply the stationarity of water discharges. The double-mass technique was developed originally as a visual technique, to assess the homogeneity of precipitation records and was extended to study variations in sediment transport in modified watersheds. More recently confidence 'rails' and slope change detection have rendered its use more quantitative. Based on the same inertial principles, the Cumulative Sum (CUSUM) functions allow simultaneous evaluation of the covariability of the two series. An example involving weekly sampled nitrate concentrations and continuously monitored water discharges is developed. PMID:24258934

Cluis, D A

1983-06-01

303

A conceptual model for assessing ecological risk to water quality function of bottomland hardwood forests  

Science.gov (United States)

Ecological risk assessment provides a methodology for evaluating the threats to ecosystem function associated with environmental perturbations or stressors. This report documents the development of a conceptual model for assessing the ecological risk to the water quality function (WQF) of bottomland hardwood riparian ecosystems (BHRE) in the Tifton-Vidalia upland (TVU) ecoregion of Georgia. Previus research has demonstrated that mature BHRE are essential to maintaining water quality in this portion of the coastal plain. The WQF of these ecosystems is considered an assessment endpoit—an ecosystem function or set of functions that society chooses to value as evidenced by laws, regulations, or common usage. Stressors operate on ecosystems at risk through an exposure scenario to produce ecological effects that are linked to loss of the desired function or assessment end point. The WQF of BHRE is at risk because of the ecological and environmental quality effects of a suite of chemical, physical, and biological stressors. The stressors are related to nonpoint source pollution from adjacent land uses, especially agriculture; the conversion of BHRE to other land uses; and the encroachment of domestic animals into BHRE. Potential chemical, physical, and biological stressors to BHRE are identified, and the methodology for evaluating appropriate exposure scenarios is discussed. Field-scale and watershed-scale measurement end points of most use in assessing the effects of stressors on the WQF are identified and discussed. The product of this study is a conceptual model of how risks to the WQF of BHRE are produced and how the risk and associated uncertainties can be quantified.

Lowrance, Richard; Vellidis, George

1995-03-01

304

A new model for the structure function of integrated water vapor in turbulence  

International Nuclear Information System (INIS)

Turbulent fluctuation of integrated water vapor in the troposphere is one of the major noise sources in radio interferometry. Processed integrated water vapor estimates from microwave radiometers colocated with interferometers have been used to set bounds on this uncertainty. The bound has been in the form of a calculated structure function, which is a measure of temporal or spatial decorrelation of fluctuations. In this paper a new model is presented for the estimation of the structure function in the absence of radiometer measurements. Using this model, the structure function can be estimated using measurements or estimates of a limited number of meteorological parameters. These parameters include boundary layer depth, surface heat and humidity fluxes, entrainment humidity flux, average virtual potential temperature in the boundary layer, and geostrophic wind speed. These parameters can be found or estimated from radiosonde and surface eddy correlation system data. The model is based on a framework of turbulence meteorology and provides excellent agreement when compared with state-of-the-art atmospheric turbulence simulations. Results of preliminary comparisons with ground truth show some excellent agreement, as well as some problems. The performance of the new model exceeds that of one current model. (c) 1999 American Geophysical Union

305

Marine sediment shear velocity structure from the ratio of displacement to pressure of Rayleigh waves at seafloor  

Science.gov (United States)

The complex ratio of vertical displacement to pressure (D/P) at seafloor is a function of frequency. It is sensitive to the subsurface elastic properties, particularly the shear modulus, and therefore can be used to determine the shear velocity and thickness of marine sediments. Instead of using compliance in response to loading of long-period infragravity waves as in previous studies, we investigate the transfer function from pressure to displacement using Rayleigh waves generated by microseisms and earthquakes. We find that at frequencies between 0.1 and 0.2 Hz, the Rayleigh wave transfer function is very sensitive to marine sediments and can be reliably obtained from microseism noise. Using a surface wave mode method, we calculate synthetic D/P ratios and examine their sensitivity to water depth, shear wave speed, and thickness of sediments. We develop a method to invert the Rayleigh wave D/P ratio for a regional 1-D profile of sediment shear wave speed and associated sediment thickness beneath each ocean bottom seismograph (OBS). We apply our method to a group of deep water OBSs deployed in the Cascadia Initiative and obtain a well-resolved depth-dependent shear wave speed for sediments on the Juan de Fuca plate and shear wave traveltime delays caused by sediments at each station.

Ruan, Youyi; Forsyth, Donald W.; Bell, Samuel W.

2014-08-01

306

The effect of precordial lead displacement on ECG morphology.  

Science.gov (United States)

Inaccurate electrode placement and differences in inter-individual human anatomies can lead to misinterpretation of ECG examination. The aim of the study was to investigate the effect of precordial electrodes displacement on morphology of the ECG signal in a group of 60 patients with diagnosed cardiac disease. Shapes of ECG signals recorded from precordial leads were compared with signals interpolated at the points located at a distance up to 5 cm from lead location. Shape differences of the QRS and ST-T-U complexes were quantified using the distribution function method, correlation coefficient, root-mean-square error (RMSE), and normalized RMSE. The relative variability (RV) index was calculated to quantify inter-individual variability. ECG morphology changes were prominent in all shape parameters beyond 2 cm distance to precordial leads. Lead V2 was the most sensitive to displacement errors, followed by leads V3, V1, and V4, for which the direction of electrodes displacement plays a key role. No visible changes in ECG morphology were observed in leads V5 and V6, only scaling effect of signal amplitude. The RV ranged from 0.639 to 0.989. Distortions in ECG tracings increase with the distance from precordial lead, which are specific to chosen electrode, direction of displacement, and for ECG segment selected for calculations. PMID:24142562

Kania, Micha?; Rix, Hervé; Fereniec, Ma?gorzata; Zavala-Fernandez, Heriberto; Janusek, Dariusz; Mroczka, Tomasz; Stix, Günter; Maniewski, Roman

2014-02-01

307

Large-displacement strain theory and its application to graphene  

Science.gov (United States)

Under the application of a force a material will deform and, hence, the crystal lattice will experience strain. This induced strain will alter the electronic properties of the material. In particular, strain in graphene generates an artificial vector potential that, if spatially varying, admits a pseudomagnetic field. Current theories for spatially varying strain use linear or finite strain theory, whose derivation is based on small displacements of infinitesimal length vectors. Here we apply a differential geometry method to derive a strain theory for large displacements of finite length vectors. This method gives a finite displacement term whose contribution is comparable to that of the linear strain term. Furthermore, we show that a "domain-wall"-like pseudomagnetic-field profile can be generated when a wide graphene ribbon is subjected to a pair of opposing point forces (point stretch). The resulting field is a function of the new finite displacement term only and displays a maximum strength of over three times that which is predicted by the linear strain theory. These results extend the current theories of strain, which are based on the transformation of infinitesimal length vectors, to finite length vectors, thus providing an accurate description of pseudomagnetic-field structures in strained materials.

Crosse, J. A.

2014-07-01

308

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

309

Flood Reduction Function of Paddy Rice Fields under Different Water Saving Irrigation Techniques  

Directory of Open Access Journals (Sweden)

Full Text Available This study is conducted to investigate the function of paddy fields for flood reduction under different water saving irrigation techniques. A daily water balance component data including rainfall, percolation, and overflow through the paddy field levee were collected from experimental paddy rice fields during rainy season cultivation. Results show that paddy field was very effective in flood reduction. More than 40% of rainfall could be stored in the paddy fields. However, the effectiveness of paddy fields in flood reduction was highly depends on the WSI technique used. Semi dry cultivation technique was the most effective one in terms of flood reduction. It retained the rainfall up to 55.7% (365 mm of the total rainfall (636 mm without reducing the yield. In terms of flood volume reduction, the alternate wetting and drying performed similarly with traditional continuous flooding, i.e., 37.2% and 40.8%, respectively.

Joko Sujono

2010-06-01

310

Analysis of water hammer in pipelines by partial fraction expansion of transfer function in frequency domain  

International Nuclear Information System (INIS)

Understanding water hammer is very important to the prevention of excessive pressure build-up in pipelines. Many researchers have studied this phenomenon, drawing effective solutions through the time- and frequency-domain approaches. For the purposes of enhancing the advantages of the frequency-domain approach and, thereby, rendering investigations of the dynamic characteristics of pipelines more effective, we propose partial fraction expansion of the transfer function between the unsteady flow source and a given section. We simulate the proposed approach using a vibration element inserted into a simple pipeline, deducing much useful physical information pertaining to pipeline design. We conclude that locating the resonance of the vibration element between the first and second resonances of the pipeline can mitigate the excessive pressure build-up attendant on the occurrence of water hammer. Our method of partial fraction expansion is expected to be useful and effective in analyses of unsteady flows in pipelines

311

Iterated function system fractal image code on instability of vapor-water two-phase flow  

International Nuclear Information System (INIS)

A novel method is put forward for studying the instability of vapor-water two-phase flow. This method combines data compression and denoising based on wavelet analysis with the iterated function system (IFS) fractal image code techniques. Firstly, the experiment data are compressed and denoised by wavelet and the data signals can be expressed by the low and high main frequency coefficients of wavelet, and then the fractal codes are abstracted from the compressed experiment data based on IFS. The fractal codes can be divided into low and high frequency parts automatically. The farther studies on the instability of vapor-water two-phase flow can be carried out based on these fractal codes. (authors)

312

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

Science.gov (United States)

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

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

2014-11-01

313

Water transport between CNS compartments: functional and molecular interactions between aquaporins and ion channels.  

Science.gov (United States)

The physiological ability of the mammalian CNS to integrate peripheral stimuli and to convey information to the body is tightly regulated by its capacity to preserve the ion composition and volume of the perineuronal milieu. It is well known that astroglial syncytium plays a crucial role in such process by controlling the homeostasis of ions and water through the selective transmembrane movement of inorganic and organic molecules and the equilibration of osmotic gradients. Astrocytes, in fact, by contacting neurons and cells lining the fluid-filled compartments, are in a strategic position to fulfill this role. They are endowed with ion and water channel proteins that are localized in specific plasma membrane domains facing diverse liquid spaces. Recent data in rodents have demonstrated that the precise dynamics of the astroglia-mediated homeostatic regulation of the CNS is dependent on the interactions between water channels and ion channels, and their anchoring with proteins that allow the formation of macromolecular complexes in specific cellular domains. Interplay can occur with or without direct molecular interactions suggesting the existence of different regulatory mechanisms. The importance of molecular and functional interactions is pinpointed by the numerous observations that as consequence of pathological insults leading to the derangement of ion and volume homeostasis the cell surface expression and/or polarized localization of these proteins is perturbed. Here, we critically discuss the experimental evidence concerning: (1) molecular and functional interplay of aquaporin 4, the major aquaporin protein in astroglial cells, with potassium and gap-junctional channels that are involved in extracellular potassium buffering. (2) the interactions of aquaporin 4 with chloride and calcium channels regulating cell volume homeostasis. The relevance of the crosstalk between water channels and ion channels in the pathogenesis of astroglia-related acute and chronic diseases of the CNS is also briefly discussed. PMID:20026249

Benfenati, V; Ferroni, S

2010-07-28

314

Water relations of seedlings of Scots pine grown in peat as a function of soil water potential and soil temperature  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Seedlings of Pinus sylvestris, grown in low humified peat, were exposed to different soil water potentials (?s) and soil temperatures. The water potential and temperature were controlled by the use of a semi-permeable membrane system, and the seedlings were placed in a growth chamber during the experiments. Needle water potential (?s), needle conductance (g,) and plant water conductance (Gp) were measured on the seedlings. When the soil water potential decreased to - 0.1 MPa, the g, decreased...

O?rlander, Go?ran; Due, Karin

1986-01-01

315

Displacement chromatography of isomers and therapeutic compounds.  

Science.gov (United States)

Displacement chromatography was successfully used to separate a binary isomer mixture, epirubicin and doxorubicin, on Kromasil KR100-10 C18 250x4.6 mm I.D. (10 microm) column. Displacement parameters such as the types and the concentrations of displacer, the composition and the flow rate of the mobile phase were critically examined in this study. The displacer employed was 30 mg/ml benzethonium chloride. Loading of feed at lower initial organic level of mobile phase coupled with displacement at higher organic level was found to give efficient separation. A 30-mg amount of binary isomer mixture was separated on an analytical column. The purification of epirubicin from the closely related impurities present in raw product solution by displacement chromatography was also investigated. The purity of epirubicin required was greater than 99% with a recovery of 60%. The results have indicated that this process made good use of the high feed load, low solvent costs, and high resolution characteristics of displacement chromatography and offered the chromatographic engineer a powerful tool for the preparative purification of therapeutic compounds. PMID:12141564

Qi, Yan; Huang, Junxiong

2002-06-14

316

Percutaneous calcaneoplasty in displaced intraarticular calcaneal fractures.  

Science.gov (United States)

The ideal treatment for displaced intraarticular calcaneal fractures is still under debate. Open reduction and internal fixation is the most popular surgical procedure; however, wound complications, hardware failure and infection remain a major concern. The aim of this study was to evaluate the results of a new minimally-invasive surgical procedure: closed reduction technique combined with balloon-assisted fracture augmentation with cement or calcium phosphate (minimally-invasive percutaneous calcaneoplasty). We retrospectively reviewed 11 patients that sustained Sander's type II and III calcaneal fractures treated in our institution from January 2008 to June 2010. The same approach and technique was utilized in all cases. Conventional X-rays and CT scan have been performed pre- and post-operatively. The average follow-up was 24 months. The American Orthopaedic Foot and Ankle Society ankle/hindfoot score has been utilized for clinical evaluation and Bohler's angle to assess bone reduction. All cases obtained bony union in 2/3 months, with average Bohler's angle of 22.97° (from 14.21° to 32.83°). No skin complications or adverse reactions were observed, with only one patient complaining of residual pain in the hindfoot. Minimally-invasive percutaneous calcaneoplasty can represent an alternative to open reduction internal fixation in the treatment of calcaneal fractures, allowing stable reduction without plating, early function recovery and short hospital stay. PMID:23744105

Biggi, Francesco; Di Fabio, Stefano; D'Antimo, Corrado; Isoni, Francesco; Salfi, Cosimo; Trevisani, Silvia

2013-12-01

317

A comparative study of dielectric response function models for liquid water  

International Nuclear Information System (INIS)

Various methodologies that aim at an analytic representation of the dielectric response function (DRF) of liquid water with emphasis on the Bethe ridge region are compared. The use of optical data is a common feature to all models presented providing an empirical ground for modelling the valence energy losses where many-body (and phase) effects are expected to be most prevalent. The dispersion models used for describing the momentum dependence of the DRF are evaluated against the recent inelastic X-ray scattering (IXS) spectroscopy data. Recent developments along the lines of Ritchie's extended-Drude scheme for an improved representation of the experimental Bethe ridge are presented. (authors)

318

The numerical calculation on displacement damage of Si and GaAs semiconductor material irradiated by neutron  

International Nuclear Information System (INIS)

Displacement damage function and damage level characterization of semiconductor material irradiated by neutron is summarized. With damage function from ASTM E722-94, the displacement damage of Si and GaAs irradiated by Maxwell fission neutron and Gaussian fusion neutron is calculated by MCNP program as well as equivalent parameter of damage for 1 MeV neutron. (authors)

319

Percolation line, response functions, and Voronoi polyhedra analysis in supercritical water  

Directory of Open Access Journals (Sweden)

Full Text Available The problem of a physical relevance (meaning of percolation in supercritical fluids is addressed considering a primitive model of water. Two different criteria, physical and configurational, are used for the cluster definition in Monte Carlo simulations over a range of pressures to determine the percolation line and skewness, and a theoretical analytic equation of state is used to evaluate response functions. It is found that both criteria yield practically the same percolation line. However, unlike the findings for simple fluids, the loci of the response function extrema exhibit density/pressure dependence quite different from that of the percolation line. The only potential coincidence between the loci of the extrema of a thermodynamic property and a detectable structural change is found for the coefficient of isothermal compressibility and Voronoi neighbors distribution skewness maximum.

J. Škvor

2012-06-01

320

Interaction of TiO{sub 2}{sup ?} with water: Photoelectron spectroscopy and density functional calculations  

Energy Technology Data Exchange (ETDEWEB)

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

Li, Ren-Zhong [College of Electronics and Information, Xi' an Polytechnic University, Xi' an 710048 (China); Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Xu, Hong-Guang; Cao, Guo-Jin; Xu, Xi-Ling; Zheng, Wei-Jun, E-mail: zhengwj@iccas.ac.cn [Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

2013-11-14

 
 
 
 
321

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

322

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

DEFF Research Database (Denmark)

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

Hasager, Charlotte Bay; Badger, Merete

2013-01-01

323

Interface structure and reactivity of water-oxidation Ru-polyoxometalate catalysts on functionalized graphene electrodes.  

Science.gov (United States)

We combine classical empirical potentials and density functional theory (DFT) calculations to characterize the catalyst/electrode interface of a promising device for artificial photosynthesis. This system consists of inorganic Ru-polyoxometalate (Ru-POM) molecules that are supported by a graphitic substrate functionalized with organic dendrimers. The experimental atomic-scale characterization of the active interface under working conditions is hampered by the complexity of its structure, composition, as well as by the presence of the electrolyte or solvent. We provide a detailed atomistic model of the electrode/catalyst interface and show that the catalyst anchoring is remarkably dependent on water solvation. A tight host-guest binding geometry between the surface dendrimers and the Ru-POM catalyst is predicted under vacuum conditions. The solvent destabilizes this geometry, leads to unfolding of the dendrimers and to their flattening on the graphitic surface. The Ru-POM catalyst binds to this organic interlayer through a stable electrostatic link between one POM termination and the charged terminations of the dendrimers. The calculated dynamics and mobility of the Ru-POM catalyst at the electrode surface are in fair agreement with the available high-resolution transmission electron microscopy data. In addition, we demonstrate that the high thermodynamic water-oxidation efficiency of the Ru-POM catalyst is not affected by the binding to the electrode, thus rationalizing the similar electrochemical performances measured for homogeneous and heterogeneous Ru-POM catalysts. PMID:24496469

Ma, Changru; Piccinin, Simone; Fabris, Stefano

2014-03-21

324

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.

325

Effect of hypoxaemia on water and sodium homeostatic hormones and renal function  

DEFF Research Database (Denmark)

Changes in body fluid homeostasis during acute hypoxaemia suggest a crucial role of renal function in acclimatization processes. Hypoxaemia stimulates sympathetic nervous activity, and also the cardiovascular system is affected with increases in heart rate and cardiac output. In most subjects, a hypoxic ventilatory response produces hypocapnia and respiratory alkalosis. Acute hypoxaemia depresses aldosterone secretion secondary to a direct effect on adrenal cells. Also plasma renin is decreased in resting hypoxaemic conditions, but the mechanism remains unknown. These hormonal changes may have the advantage of opposing excessive sodium and water retention, which characterizes acute mountain sickness. Short-term isocapnic or hypocapnic hypoxaemia in spontaneously breathing humans causes moderate if any increases in renal blood flow and only minor changes in GFR. In contrast, renal blood flow and GFR decreases during hypercapnic hypoxaemia. Renal clearance studies in humans after 24-48 hours in altitude hypoxia(4,350 m) demonstrate that glomerular and tubular function is only slightly changed in spite of marked depression of the renin-aldosterone system and increased plasma levels of norepinephrine. However, renal vascular tone may increase most probably secondary to the increased adrenosympathetic activity. In the first hours, acute hypoxaemia may induce an increased excretion of sodium and water. Previous studies suggest that the natriuretic response is caused by decreased reabsorption of sodium and bicarbonate in the proximal tubules secondary to the associated hyperventilation and hypocapnia. After 6 hours, sodium and water excretion is normalized or even depressed, dependent on the severity of acute mountain sickness. In view of the prompt increase in sodium and water excretion found during short-term hypoxaemia, the absence of such a response to more prolonged hypoxaemia suggests an adaptive time-dependent course of renal functional changes in hypoxaemia. Taken together, previous studies suggest that effectsof acute hypoxaemia on renal haemodynamics are minor compared with effects on cerebral and coronary circulation. This might be the result of an appropriate resetting of autoregulatory mechanisms that would maintain the role of the kidney as a major sense organ to hypoxaemia and, subsequently, as a mediator of plasma volume regulation and erythropoietin synthesis.

Olsen, Niels Vidiendal

1995-01-01

326

Making work safe for displaced women  

Directory of Open Access Journals (Sweden)

Full Text Available Displaced women need opportunities to make a living for themselves and their families but these opportunities should not increase their vulnerability. Understanding risk factors and protection strategies allows practitioners to ensure appropriate programme design and implementation.

Dale Buscher

2012-12-01

327

Natural disasters and indigenous displacement in Bolivia  

Directory of Open Access Journals (Sweden)

Full Text Available Those seeking to understand and address the reasons for growing numbers of displaced indigenous people in Bolivia should consider the relationship between traditional knowledge and the impacts of climate change.

Ludvik Girard

2012-12-01

328

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

329

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

330

An old test for new neurons: refining the Morris water maze to study the functional relevance of adult hippocampal neurogenesis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Morris water maze represents the de-facto standard for testing hippocampal function in laboratory rodents. In the field of adult hippocampal neurogenesis, however, using this paradigm to assess the functional relevance of the new neurons yielded surprisingly inconsistent results. While some authors found aspects of water maze performance to be linked to adult neurogenesis, others obtained different results or could not demonstrate any effect of manipulating adult neurogenesis. In this rev...

Garthe, Alexander; Kempermann, Gerd

2013-01-01

331

Complex electrical properties of shale as a function of frequency and water content  

Science.gov (United States)

The objective of this study is to analyze the change in complex electrical permittivity of shale as a function of water content. An experimental research program has been initiated to investigate the electrical properties of swelling shales, shales that have been exposed to water and are therefore expanding, across a wide frequency range, 5 Hz to 1.3 GHz. This range spans the spectrum of the commonly used down-hole logging measurements from the deep laterologs to the microwave dielectric tools. Two distinct measurement techniques have been used to span the range: four-electrode with balanced bridge for the low frequencies, and open-ended coaxial probe with network analyzer at the high end. The probe technique is simple to use, potentially enabling field measurements of complex permittivity to be taken, although some accuracy is sacrificed. The effects of swelling are most pronounced at the lowest frequencies. This investigation discovered a phenomenon of shale: it will generate a direct electrical current under stress that has a potential for a wellbore diagnostic tool. Also the best fluid for shale preservation was found to be Isopar M TM, a mineral oil saturated with deionized water.

Adisoemarta, Paulus Suryono

1999-10-01

332

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

333

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

334

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

Energy Technology Data Exchange (ETDEWEB)

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

Desjarlais, Michael Paul; Mattsson, Thomas Kjell Rene

2006-03-01

335

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

Energy Technology Data Exchange (ETDEWEB)

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 CH{sub 3} 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 isomers.

Fu Aiping; Li Hongliang; Zhou Zhengyu; Feng Dacheng

2004-03-29

336

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

Science.gov (United States)

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

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

2011-12-01

337

Quantifying Bedform Geometry, Water Configuration, and Melt Rate Beneath Thwaites Glacier from Radar Scattering Functions  

Science.gov (United States)

The morphological, lithological, and hydrological basal boundary conditions of ice-sheets and glaciers can exert strong, even dominating, control on their behavior, evolution and stability. However, the scales at which the physical processes and observable signatures of this control occur are typically smaller than the spatial resolutions achievable using ice penetrating radar. Further, the strength of calibrated radar bed echo returns is a combination of both the material (i.e., relative permittivity, conductivity) and geometric (i.e., rms height, rms slope, auto correlation length) properties of the ice/bed interface. This ambiguity in the relative contribution of material and geometric bed properties, along with uncertainty in englacial attenuation from underconstrained ice temperature and chemistry, also makes definitive assessment of basal conditions from echo strengths extremely difficult. To address these challenges in interpreting geometric and material bed properties at glaciologically relevant scales, we apply a new algorithmic approach to measuring the radar scattering function of the ice/bed interface by performing range-migrated SAR focusing using multiple reference functions spanning different ranges of Doppler frequencies for the bed. We parameterize this scattering function in terms of the relative contribution of angularly narrow specular energy and isotropically scattered diffuse energy. This specularity content of the bed echo is insensitive to englacial attenuation and is a measure of both the angular distribution of returned echo energy and the geometry of the ice/bed interface at the sub-azimuth-resolution scale. We present the application of this technique to a gridded airborne radar survey over the entire catchment of Thwaites Glacier, West Antactica. We show how the information in the along-track scattering function of the bed can be used to assess the extent and configuration of distributed water across the catchment and detect the transition of the water system from distributed canals to concentrated channels. We also show how this information can be used to constrain the morphology of basal bedforms and infer the distribution of deformable sediments and crystalline bedrocks across the catchment. Finally, we compare the specularity and amplitude of bed echoes with the upstream drainage area of the distributed portion of the subglacial water system to constrain basal melt rates across the catchment.

Schroeder, D. M.; Blankenship, D. D.; Young, D. A.

2013-12-01

338

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

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: MB-rGO was synthesized by making use of {pi} 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: Black-Right-Pointing-Pointer Methyl blue (MB) stacks onto the plane of reduced graphene oxide (rGO) by strong {pi}-{pi} interactions. Black-Right-Pointing-Pointer Sulfo groups of MB prevent rGO from aggregating by electrostatic and steric repulsions. Black-Right-Pointing-Pointer MB-functionalized rGO (MB-rGO) shows excellent solubility and stability in aqueous solution. Black-Right-Pointing-Pointer Electrical conductivity of MB-rGO is almost two orders of magnitude larger than that of GO. -- Abstract: {pi} 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.

Cai, Xiang [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Tan, Shaozao, E-mail: shaozao@tom.com [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Xie, Agui; Lin, Minsong; Liu, Yingliang [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Zhang, Xiuju; Lin, Zhidan [Department of Material Science and Engineering, Jinan University, Guangzhou 510632 (China); Wu, Ting [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Mai, Wenjie, E-mail: wenjiemai@gmail.com [Department of Physics, Jinan University, Guangzhou 510632 (China)

2011-12-15

339

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

340

Micromachined capacitive long-range displacement sensor  

Digital Repository Infrastructure Vision for European Research (DRIVER)

First measurement results are presented for a surface-micromachined long-range (50– 100 ?m) periodic capacitive position sensor. The sensor consists of two periodic geometries (period = 10 ?m) sliding along each other with minimum spacing of about 1.5 ?m. The relative displacement between the two, results in a periodic change in capacitance. An electrostatic comb-drive actuator is employed to generate displacements. Measured maximum capacitance change ?C=0.72 fF corresponds to simulatio...

Kuijpers, Toon A. A.; Krijnen, Gijs J. M.; Lammerink, Theo S. J.; Wiegerink, Remco J.; Elwenspoek, Miko C.

2003-01-01

 
 
 
 
341

Anomalous displacement in osmium-substituted beryllium  

International Nuclear Information System (INIS)

Experimental evidence has been obtained, by the ion-beam channeling technique, that an osmium atom introduced into beryllium metal occupies positions displaced from a regular substitutional lattice site. The anomalous displacement is found to persist after annealing to a temperature above that at which impurity diffusion occurs. Of the several heavy-metal impurities in beryllium which have been previously studied, osmium is unique in this respect

342

Effects of Fault Displacement on Emplacement Drifts  

International Nuclear Information System (INIS)

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

343

Incorporating the effects of changes in vegetation functioning and CO2 on water availability in plant habitat models  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The direct effects of CO2 level changes on plant water availability are usually ignored in plant habitat models. We compare traditional proxies for water availability with changes in soil water (fAWC) predicted by a process-based ecosystem model, which simulates changes in vegetation structure and functioning, including CO2 physiological effects. We modelled current and future habitats of 108 European tree species using ensemble forecasting, comprising six habitat models, two model evaluation...

Rickebusch, Sophie; Thuiller, Wilfried; Hickler, Thomas; Arau´jo, Miguel B.; Sykes, Martin T.; Schweiger, Oliver; Lafourcade, Bruno

2008-01-01

344

Study of the technology of decontamination of water which has been regenerated from the liquid products of human vital functions  

Science.gov (United States)

Decontamination of water during its regeneration from products of the vital functions of man is considered. It has been shown that the starting products may contain a large quantity of microflora. In order to guarantee decontamination of the regenerated water the following technological procedures have been developed: conservation of urine, filtration of condensate of water through sorbents, and preparation of components of a system from materials which have antimicrobial properties.

Kryuchkov, V. A.; Rogatina, L. N.

1973-01-01

345

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 Sousa; Geraldo Arraes Maia; Joelia Marques Carvalho

2006-01-01

346

A time correlation function theory of two-dimensional infrared spectroscopy with applications to liquid water.  

Science.gov (United States)

A theory describing the third-order response function R((3))(t(1),t(2),t(3)), which is associated with two-dimensional infrared (2DIR) spectroscopy, has been developed. R((3)) can be written as sums and differences of four distinct quantum mechanical dipole (multi)time correlation functions (TCF's), each with the same classical limit; the combination of TCF's has a leading contribution of order variant Planck's over 2pi (3) and thus there is no obvious classical limit that can be written in terms of a TCF. In order to calculate the response function in a form amenable to classical mechanical simulation techniques, it is rewritten approximately in terms of a single classical TCF, B(R)(t(1),t(2),t(3))=micro(j)(t(2)+t(1))micro(i)(t(3)+t(2)+t(1))micro(k)(t(1))micro(l)(0), where the subscripts denote the Cartesian dipole directions. The response function is then given, in the frequency domain, as the Fourier transform of a classical TCF multiplied by frequency factors. This classical expression can then further be quantum corrected to approximate the true response function, although for low frequency spectroscopy no correction is needed. In the classical limit, R((3)) becomes the sum of multidimensional time derivatives of B(R)(t(1),t(2),t(3)). To construct the theory, the response function's four TCF's are rewritten in terms of a single TCF: first, two TCF's are eliminated from R((3)) using frequency domain detailed balance relationships, and next, two more are removed by relating the remaining TCF's to each other within a harmonic oscillator approximation; the theory invokes a harmonic approximation only in relating the TCF's and applications of theory involve fully anharmonic, atomistically detailed molecular dynamics (MD). Writing the response function as a single TCF thus yields a form amenable to calculation using classical MD methods along with a suitable spectroscopic model. To demonstrate the theory, the response function is obtained for liquid water with emphasis on the OH stretching portion of the spectrum. This approach to evaluating R((3)) can easily be applied to chemically interesting systems currently being explored experimentally by 2DIR and to help understand the information content of the emerging multidimensional spectroscopy. PMID:15303935

DeVane, Russell; Space, Brian; Perry, Angela; Neipert, Christine; Ridley, Christina; Keyes, T

2004-08-22

347

Functional groups of marine ciliated protozoa and their relationships to water quality.  

Science.gov (United States)

Ciliated protozoa (ciliates) play important ecological roles in coastal waters, especially regarding their interaction with environmental parameters. In order to increase our knowledge and understanding on the functional structure of ciliate communities and their relationships to environmental conditions in marine ecosystems, a 12-month study was carried out in a semi-enclosed bay in northern China. Samples were collected biweekly at five sampling stations with differing levels of pollution/eutrophication, giving a total of 120 samples. Thirteen functional groups of ciliates (A-M) were defined based on their specific spatio-temporal distribution and relationships to physico-chemical parameters. Six of these groups (H-M) were the primary contributors to the ciliate communities in the polluted/eutrophic areas, whereas the other seven groups (A-G) dominated the communities in less polluted areas. Six groups (A, D, G, H, I and K) dominated during the warm seasons (summer and autumn), with the other seven (B, C, E, F, J, L and M) dominating in the cold seasons (spring and winter). Of these, groups B (mainly aloricate ciliates), I (aloricate ciliates) and L (mainly loricate tintinnids) were the primary contributors to the communities. It was also shown that aloricate ciliates and tintinnids represented different roles in structuring and functioning of the communities. The results suggest that the ciliate communities may be constructed by several functional groups in response to the environmental conditions. Thus, we conclude that these functional groups might be potentially useful bioindicators for bioassessment and conservation in marine habitats. PMID:23381800

Jiang, Yong; Xu, Henglong; Hu, Xiaozhong; Warren, Alan; Song, Weibo

2013-08-01

348

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 < 0.05, Cohen's effect size: 1.3, 38%) after CWI compared with active recovery. During CWI, muscle temperature decreased ?7°C below postexercise values and remained below preexercise values for another 35 min. Venous blood O2 saturation decreased below preexercise values for 1.5 h after CWI. Serum endothelin-1 concentration did not change after CWI, whereas it decreased after active recovery. Plasma myoglobin concentration was lower, whereas plasma IL-6 concentration was higher after CWI compared with active recovery. These results suggest that CWI after resistance exercise allows athletes to complete more work during subsequent training sessions, which could enhance long-term training adaptations. PMID:25121612

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

2014-10-15

349

Viscosity and stress autocorrelation function in supercooled water: a molecular dynamics study  

Science.gov (United States)

Following GUO, G.-J., and ZHANG, Y.-G., 2001, Molec. Phys. , 99 , 283, which calculates the bulk and shear viscosities of SPC/E water at 30°C and 0.999gcm -3 , further molecular dynamics simulations have been performed at state points of 0°C,-20°C,-40°C, and -60°C along an approximate isobar with the previous state point. SACF and BACF (stress autocorrelation functions related to shear and bulk viscosities, respectively) of high precision have been obtained and compared for their similarities and differences. Shear and bulk viscosities calculated from them showed an increased deviation from real water with decreasing temperature. These correlation functions were then fitted using a uniform two-step relaxation function including a fast oscillatory Kohlrausch law and a slow straightforward Kohlrausch law. The fitting parameters of SACF and BACF have been analysed in detail, and several interesting dynamic phenomena were observed. (1) The oscillation frequency of SACF (44 ~ 48ps -1 ) for short time intervals agrees with the stretching mode of hydrogen bonds, while that of BACF (7 ~ 12ps -1 ) agrees with the bending mode of hydrogen bonds. (2) With decreasing temperature, the slow relaxation fraction of the BACF increases, while that of the SACF remains constant. (3) The exponents ?in the Kohlrausch laws with values greater than 1 are obtained for BACF at ambient temperatures. (4) With regard to both shear and bulk viscosities, the slow relaxation time largely increases with decreasing temperature, while the fast relaxation time slightly decreases. These phenomena are qualitatively explained and discussed.

Guo, Guang-Jun; Zhang, Yi-Gang; Refson, Keith; Zhao, Ya-Juan

350

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

351

Structure and functions of simple membrane-water interfaces. [Abstract only  

Science.gov (United States)

The structure and functions of the earliest ancestors of contemporary cells are focal points in studies of the origin of life. Probably the first cell-like structures were vesicles - closed, spheroidal structures with aqueous medium trapped inside. The membranous walls of vesicles were most likely bilayers composed of simple amphiphilic material available on early earth. The membrane studied was composed of glycerol 1-monooleate (GMO). Glycerol forms the polar head group and the oily tail contains 18 carbon atoms. All head groups have been found to be located in two narrow regions at the interfaces with water. The membrane interior, formed by the hydrophobic tails, is quite fluid with chain disorder increasing towards the center of the bilayer. These results are in agreement with x-ray and neutron scattering data from related bilayers. The width of the membrane is not constant, but fluctuates in time and space. Occasional thinning defects in the membrane, observed during the course of the simulations, may have a significant influence on rates of passive transport of small molecules across membranes. It has been found that water penetrates the head group region but not the oily interior of the membrane. Water molecules near the interface are oriented by dipoles of the head groups. The resulting electrostatic potential across the interface, determined in our simulations, has been found to be markedly larger than across the water-oil interface. This quantity has been implicated as the source of selectivity, with respect to the sign of the charge, as an ion approaches the interface and during transport of hydrophobic ions across membranes.

Pohorille, A.; Wilson, M. A.

1994-01-01

352

Structure and functions of water-membrane interfaces and their role in proto-biological evolution  

Science.gov (United States)

Among the most important developments in proto-biological evolution was the emergence of membrane-like structures. These are formed by spontaneous association of relatively simple amphiphilic molecules that would have been readily available in the primordial environment. The resulting interfacial regions between water and nonpolar interior of the membrane have several properties which made them uniquely suitable for promoting subsequent evolution. They can (1) selectively attract organic material and mediate its transport, (2) serve as simple catalysts for chemical reactions, and (3) promote the formation of trans-membrane electrical and chemical gradients which could provide energy sources for proto-cells. Understanding the structure of interfaces, their interactions with organic molecules and molecular mechanisms of their functions is an essential step to understanding proto-biological evolution. In our computer simulation studies, we showed that the structure of water at interfaces with nonpolar media is significantly different from that in the bulk. In particular, the average surface dipole density points from the vapor to the liquid. As a result, negative ions can approach the interface more easily than positive ions. Amphiphilic molecules composed of hydrocarbon conjugated rings and polar substituents (e.g., phenol) assume at the interface rigid orientations in which polar groups are buried in water while hydrocarbon parts are located in the nonpolar environment. These orientational differences are of special interest in connection with the ability of some of these molecules to efficiently absorb photons. Flexible molecules with polar substituents often adopt at interfaces conformations different from those in the bulk aquaeous solution and in the gas phase. As a result, in many instances both specificity and kinetics of chemical reactions in which these molecules can participate is modified by the presence of surfaces. Of special interest is the mechanism by which polar molecules are transferred across interface between water and a nonpolar medium. Our recent study showed that simple ionophores bind ions by the same mechanisms as ion channels and carriers from modern cells.

Pohorille, A.; Wilson, M.; Macelroy, R. D.

1991-01-01

353

Water Storage Dynamics of Saturated and Unsaturated Zones and its Function in Hydrological Modeling  

Science.gov (United States)

Subsurface water storage for hydrological processes can be divided into unsaturated soil moisture and saturated water storage (a shallow groundwater aquifer). Surface layer moisture content is a state variable that is either simulated or required as input in many hydrological models. The high or low of the shallow groundwater reservoir fast or slow of saturated flow and flow discharges from the catchment outlet. As a result of heterogeneity of soil properties, topography, land cover, evapotranspiration and precipitation, the soil moisture content and the shallow groundwater reservoir is highly variable in three-dimensional space and time (Engman, 1974; Wood et al., 1992). Expression of heterogeneity of soil moisture content and the shallow groundwater storage is critical for hydrological model development and success in hydrological simulation. In this study, we developed a new hydrological model with functions of water storage dynamics of saturated and unsaturated zones. A mathematical expression of topographic and soil controlled spatial heterogeneity of soil moisture holding capacity was derived in terms of Van Genuchten model and topographical index. The subsurface store and storage-discharge process is expressed by a horizontal Boussinesq equation with a power law hydraulic conductivity profile (Rupp and Selker, 2005). The "top-down" approach according to unsaturated accounting and the "bottom-up" approach according to baseflow separation were used to integrate both storage dynamics for developing the new model. The top-down and bottom-up methods enable the model parameters to be determined according to watershed soil, topography and flow discharge. Model testing was carried out in a number of nested sub-basins of a watershed (Huangnizhuang River in Huaihe basin) in the humid region in China. Simulation results show that the model is capable of describing spatial and temporal variations of water balance components, including soil moisture content, shallow groundwater storage, evapotranspiration and runoff, over the watershed. References: Engman, E.T., Rogowski, A.S. 1974. A partial area model for storm flow synthesis. Water Resources Research, 10: 464 - 472. Rupp D R, Selker J S. 2005. Drainage of a horizontal Boussinesq aquifer with a power law hydraulic conductivity profile.Water Resource Research, 41, W11422, doi:10.1029/2005WR004241. Wood, E.F., Lettenmaier, D.P., Zatarian, V.G. 1992. A land surface hydrology parameterization with subgrid variability for general circulation models. Journal of Geophysical Research, 97: 2717 - 2728.

Chen, X.; Zhang, Z.; Gao, M.; Song, Q.

2012-12-01

354

Uncertainty in Multimodel Water Flow Simulation Associated with Pedotransfer Functions and Weighting Methods  

Science.gov (United States)

Multimodeling (MM) has been developed during the last decade to improve prediction capability of hydrological models. The MM combined with the pedotransfer functions (PTFs) was successfully applied to soil water flow simulations. This study examined the uncertainty in water content simulations associated with the PTFs and MM weighting methods. Data on soil water contents were collected at the USDA-ARS Beltsville OPE3 field site from January to November 2007. Four locations were instrumented with Multisensor Capacitance Probes (SENTEK) to measure soil water content at depths from 10 to 100 cm with 10 cm increment. Standard meteorological data were measured in the vicinity of the site. Undisturbed soil samples were taken from the same depths to measure soil bulk density (BD), organic carbon content (OC) and soil texture in all locations. Fourteen PTFs, that had been developed from relatively large datasets (>200), were used to calculate soil hydraulic properties for each individual depth from measured BD, OC and soil texture. Thus, 14 sets of hydraulic parameters were obtained for each location. Then we solved the Richards equation with each set of hydraulic parameters for each location. Weighted predictions of those models were combined to obtain the multimodel predictions. The following weighting methods were compared in this study: (i) using only the best model; (ii) assigning equal weights to all models; (iii) using the superensemble; (iv) using the superensemble with the singular-value decomposition to find weights; (v) using Bayesian model averaging; and (vi) using information theory. The weighting methods were evaluated in terms of their accuracy and uncertainty (the average error and the standard deviation of errors in reproducing the test data). The multimodel training, i.e., weight determination, was done with daily water contents using moving windows that were from 30 to 150 day wide. All data outside the windows were used to test the model prediction. Generally, accuracy increased, while certainty decreased with an increase in the length of the training period. Weights of PTFs varied with depth for each location that meant these PTFs had different accuracy in predicting soil water content. Also different PTFs were used in models for the same depth at different locations, which implied that PTFs selection was depth- and site-specific. Accuracy and uncertainty of the multimodeling varied for six weighing methods. Best results were obtained with the singular value decomposition method; equal weighting resulted in the worst prediction. The highest uncertainty was associated with the singular value decomposition method. No statistically significant difference in the standard deviation of prediction errors was found between other weighting methods.

Guber, A.; Pachepsky, Y. A.; van Genuchten, M.; Rowland, R.; Nicholson, T. J.; Cady, R.

2009-12-01

355

Thermodynamic functions and phase diagram of water and high-pressure ices: Implication to an outer water-ice shell of Ganymede  

Science.gov (United States)

Water and water ice are important components of many space objects. Astrophysical and spectroscopic research shows that Solar system giant planets' satellites (Europa, Ganymede, Callisto, Titan & Enceladus), small transneptunian planets, asteroids and comets contain considerable amount of water and ice. «Galileo» and «Cassini-Huygens» missions show that liquid water could possibly exist under outer ice shells of Jupiter and Saturn satellites. Water oceans also hypothetically exist on Triton, Pluton and icy objects of Kuiper belt. Phase composition numerical modeling is the main method of internal structure and chemical evolution research for mentioned objects. Available physicochemical models of icy satellites' internal structure are based on geophysical and geochemical data obtained by space missions on one hand, and on thermodynamic data and equations of state on considered minerals and water phases on the other. This research attempts to summarize experimental and theoretical data on water and ices Ih, II, III, V, VI, VII, VIII, X phase diagram and their thermodynamic properties. Based on mathematical processing of equations of state for high-pressure ices and experimental data on phase transitions in water-ices system, phase equilibrium is being modeled and thermodynamic functions values (Gibbs free energy, enthalpy, entropy and volume change) for most phase transitions are computed. Based on geophysical (mass and moment of inertia from recent Galileo gravity measurements), geochemical (composition of chondrites) and thermodynamic (phase diagram of water and ices) constraints internally consistent models of Ganymede constitution are built. Total thickness of an outer water-ice shell of Ganymede is estimated.

Antsyshkin, Dmitry; Dunaeva, Anna; Kuskov, Oleg

2010-05-01

356

Analysis of displacement damage effects on MOS capacitors  

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-12-01

357

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

358

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

359

Iliac apophyseal displacement: an alternative in pediatric pelvic osteotomies.  

Science.gov (United States)

The traditional surgical exposure for a Salter or Chiari pelvic osteotomy involves splitting the iliac apophysis to facilitate subperiosteal separation of the muscles of the inner and outer table of the ilium. With healing, the iliac crest frequently becomes broad and prominent, and the iliac wing hypoplastic. We addressed this issue by separating the whole iliac apophysis laterally at the junction of cartilage and bone and displacing it medially. The ilium was then exposed by subperiosteal dissection of the inner and outer table musculature. From February 1988 to June 2000, twenty-five pelvic osteotomies were performed utilizing this approach. Satisfactory exposure was achieved in each case. All osteotomies healed without iliac growth disturbances, leaving excellent cosmetic results. Resuturing the previously elevated external oblique abdominus over the iliac apophysis further improved contour and appearance, Iliac apophyseal displacement rather than splitting provided appropriate access and consistently good function and cosmesis. PMID:18510161

Handelsman, John E; Weinberg, Jacob

2008-03-01

360

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

 
 
 
 
361

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

Science.gov (United States)

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

Capel, P. D.; Larson, S. J.; Winterstein, T. A.

2001-01-01

362

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

363

48 CFR 952.226-74 - Displaced employee hiring preference.  

Science.gov (United States)

... false Displaced employee hiring preference. 952.226-74 Section 952.226-74...226-74 Displaced employee hiring preference. As prescribed in 48 CFR (DEAR...clause. Displaced Employee Hiring Preference (JUN 1997) (a) Definition....

2010-10-01

364

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.

365

External fixation for displaced 2-part proximal humeral fractures.  

Science.gov (United States)

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

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

2012-12-01

366

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

367

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 <1 × 10-6 m, relative to the air-water system. Water movement due to capillary effects will likely be minimal in 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

368

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

369

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

370

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.

371

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

372

Correlation effects among atomic thermal displacements in oscillatory diffuse neutron scattering of ZnSe  

International Nuclear Information System (INIS)

Neutron scattering measurements have been performed on powder ZnSe at 15, 150 and 300 K. The temperature dependence of diffuse scattering is observed. Oscillatory diffuse scattering intensity is clearly observed at 150 and 300 K. The diffuse scattering theory including correlation effects among atomic thermal displacements is used as background function in the Rietveld analysis. The oscillatory diffuse neutron scattering intensity is explained by including the correlation effects among atomic thermal displacements of first, second and third nearest neighboring atoms. The inter-atomic distance and temperature dependence of the values of correlation effects among atomic thermal displacements are discussed.

373

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)

374

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

International Nuclear Information System (INIS)

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

375

Changes in T-lymphocyte function of mice induced by internal exposure to tritiated water  

International Nuclear Information System (INIS)

The change in transformation function of T lymphocytes and their capacity to secrete interleukin-2 (IL-2) were observed in mice exposed to various doses of tritiated water (HTO) by a lymphocyte transformation test and a technique for measuring IL-2. The results showed that the relationship between the dosage of HTO (x, 1.0-8.0 Gy) and the ratio of transformed lymphocytes (y, %) can be expressed by y = 166.6-162.61 gx (r = -0.992), and that there is little influence on secretion of IL-2 when internal doses of HTO are from 1.0 to 4.0 Gy, but 8.0 Gy can significantly inhibite IL-2 secretion (p < 0.05)

376

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

377

High-density reconstitution of functional water channels into vesicular and planar block copolymer membranes.  

Science.gov (United States)

The exquisite selectivity and unique transport properties of membrane proteins can be harnessed for a variety of engineering and biomedical applications if suitable membranes can be produced. Amphiphilic block