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Sample records for water displacement functions

  1. The estimation of oil water displacement functions

    Scientific Electronic Library Online (English)

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

    2007-09-01

    Full Text Available 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.

  2. Protein-water displacement distributions.

    Science.gov (United States)

    Doster, Wolfgang; Settles, Marcus

    2005-06-01

    The statistical properties of fast protein-water motions are analyzed by dynamic neutron scattering experiments. Using isotopic exchange, one probes either protein or water hydrogen displacements. A moment analysis of the scattering function in the time domain yields model-independent information such as time-resolved mean square displacements and the Gauss-deviation. From the moments, one can reconstruct the displacement distribution. Hydration water displays two dynamical components, related to librational motions and anomalous diffusion along the protein surface. Rotational transitions of side chains, in particular of methyl groups, persist in the dehydrated and in the solvent-vitrified protein structure. The interaction with water induces further continuous protein motions on a small scale. Water acts as a plasticizer of displacements, which couple to functional processes such as open-closed transitions and ligand exchange. PMID:15893505

  3. Water displacement mercury pump

    Science.gov (United States)

    Nielsen, Marshall G. (Woodside, CA)

    1985-01-01

    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.

  4. Head-related transfer function filter interpolation by root displacement

    OpenAIRE

    Hacihabiboglu, H; Gunel, B; Kondoz, AM

    2005-01-01

    Head-related transfer function (HRTF) Þlters are used in virtual auditory displays for the binaural synthesis of the direction of a sound source over headphones. Once low-order HRTF Þlters are designed, the interpolation of these Þlters becomes an important is- sue for the synthesis of moving sound sources. An HRTF Þlter in- terpolation method based on the displacement of HRTF Þlter roots is proposed. It is possible to obtain a minimum-phase interpolated Þlter given that the original Þ...

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

    Science.gov (United States)

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

    2014-12-01

    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.

  6. Modified (1+1)-Dimensional Displacement Shallow Water Wave System

    International Nuclear Information System (INIS)

    Recently, a (1+1)-dimensional displacement shallow water wave system (1DDSWWS) was constructed by applying variational principle of the analytic mechanics under the Lagrange coordinates. However, fluid viscidity is not considered in the 1DDSWWS, which is the same as the famous Korteweg-de Vries (KdV) equation. We modify the 1DDSWWS and add the term related to fluid viscosity to the model by means of dimension analysis. For the perfect fluids, the coefficient of kinematic viscosity is zero, then the modified 1DDSWWS (M1DDSWWS) will degenerate to 1DDSWWS. The KdV-Burgers equation and the Abel equation can be derived from the M1DDSWWS. The calculation on symmetry shows that the system is invariant under the Galilean transformations and the spacetime translations. Two types of exact solutions and some evolution graphs of the M1DDSWWS are proposed

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

    Science.gov (United States)

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

    2013-04-01

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

  8. A many-body dissipative particle dynamics study of forced water-oil displacement in capillary.

    Science.gov (United States)

    Chen, Chen; Zhuang, Lin; Li, Xuefeng; Dong, Jinfeng; Lu, Juntao

    2012-01-17

    The forced water-oil displacement in capillary is a model that has important applications such as the groundwater remediation and the oil recovery. Whereas it is difficult for experimental studies to observe the displacement process in a capillary at nanoscale, the computational simulation is a unique approach in this regard. In the present work, the many-body dissipative particle dynamics (MDPD) method is employed to simulate the process of water-oil displacement in capillary with external force applied by a piston. As the property of all interfaces involved in this system can be manipulated independently, the dynamic displacement process is studied systematically under various conditions of distinct wettability of water in capillary and miscibility between water and oil as well as of different external forces. By analyzing the dependence of the starting force on the properties of water/capillary and water/oil interfaces, we find that there exist two different modes of the water-oil displacement. In the case of stronger water-oil interaction, the water particles cannot displace those oil particles sticking to the capillary wall, leaving a low oil recovery efficiency. To minimize the residual oil content in capillary, enhancing the wettability of water and reducing the external force will be beneficial. This simulation study provides microscopic insights into the water-oil displacement process in capillary and guiding information for relevant applications. PMID:22133087

  9. Expansion of a function about a displaced centre

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2015-01-01

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

  11. Using the Aesop's Fable Paradigm to Investigate Causal Understanding of Water Displacement by New Caledonian Crows

    OpenAIRE

    Jelbert, Sarah A.; Taylor, Alex H.; Cheke, Lucy G.; Clayton, Nicola S.; Gray, Russell D.

    2014-01-01

    Understanding causal regularities in the world is a key feature of human cognition. However, the extent to which non-human animals are capable of causal understanding is not well understood. Here, we used the Aesop's fable paradigm – in which subjects drop stones into water to raise the water level and obtain an out of reach reward – to assess New Caledonian crows' causal understanding of water displacement. We found that crows preferentially dropped stones into a water-filled tube instea...

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

    Science.gov (United States)

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

    2013-12-15

    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

  13. New method to determine initial surface water displacement at tsunami source

    Science.gov (United States)

    Lavrentyev, Mikhail; Romanenko, Alexey; Tatarintsev, Pavel

    2013-04-01

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

  14. Experimental study of displacement of viscous oil in pipes by water

    OpenAIRE

    Kazemihatami, Milad

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Larter Steve R

    2001-08-01

    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.

  17. Using the Aesop's fable paradigm to investigate causal understanding of water displacement by New Caledonian crows.

    Science.gov (United States)

    Jelbert, Sarah A; Taylor, Alex H; Cheke, Lucy G; Clayton, Nicola S; Gray, Russell D

    2014-01-01

    Understanding causal regularities in the world is a key feature of human cognition. However, the extent to which non-human animals are capable of causal understanding is not well understood. Here, we used the Aesop's fable paradigm--in which subjects drop stones into water to raise the water level and obtain an out of reach reward--to assess New Caledonian crows' causal understanding of water displacement. We found that crows preferentially dropped stones into a water-filled tube instead of a sand-filled tube; they dropped sinking objects rather than floating objects; solid objects rather than hollow objects, and they dropped objects into a tube with a high water level rather than a low one. However, they failed two more challenging tasks which required them to attend to the width of the tube, and to counter-intuitive causal cues in a U-shaped apparatus. Our results indicate that New Caledonian crows possess a sophisticated, but incomplete, understanding of the causal properties of displacement, rivalling that of 5-7 year old children. PMID:24671252

  18. Mean square displacement evaluation by elastic neutron scattering self-distribution function

    Science.gov (United States)

    Magazù, Salvatore; Maisano, Giacomo; Migliardo, Federica; Benedetto, Antonio

    2008-06-01

    In the present work an operational recipe for the mean square displacement (MSD) determination, highlighting the connection between elastic incoherent neutron scattering (EINS) intensity profiles and the associated self-distribution function, is presented. The determination of the thermal behavior of the total MSD and of its partial contributions is tested on EINS data collected by the backscattering spectrometer IN13 (ILL, Grenoble) on a model system such as PolyEthylene Glycol with a mean molecular weight of 400 Dalton (PEG 400).

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

    OpenAIRE

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

    2005-01-01

    The methods of density-functional perturbation theory may be used to calculate various physical response properties of insulating crystals including elastic, dielectric, Born charge, and piezoelectric tensors. These and other important tensors may be defined as second derivatives of the total energy with respect to atomic-displacement, electric-field, or strain perturbations, or as mixed derivatives with respect to two of these perturbations. The resulting tensor quantities ...

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

    International Nuclear Information System (INIS)

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

  1. Mean square displacement from self-distribution function evaluation by elastic incoherent neutron scattering

    Science.gov (United States)

    Magazù, S.; Maisano, G.; Migliardo, F.; Benedetto, A.

    2008-06-01

    The determination of the different contributions to the mean square displacement (MSD) associated with different relaxation mechanisms together with their time and thermal behaviour is performed by evaluating the self-distribution function derived by Elastic Incoherent Neutron Scattering (EINS). The analysis of the standard approach for MSD determination leads to an operational recipe that highlights the connection with the self-distribution function. The approach is tested on EINS data collected by the backscattering spectrometer IN13 (ILL, Grenoble) on a model system such as PolyEthylene Glycol with mean molecular weight Mw = 400 (PEG 400).

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

    CERN Document Server

    Jung, Youngeui

    2013-01-01

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

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

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C; Aage, Helle Karina

    2006-01-01

    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.

  4. Nozzle optimization for water jet propulsion with a positive displacement pump

    Science.gov (United States)

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

    2014-06-01

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

  5. Modified (2+1)-dimensional displacement shallow water wave system and its approximate similarity solutions

    International Nuclear Information System (INIS)

    Recently, a new (2+1)-dimensional shallow water wave system, the (2+1)-dimensional displacement shallow water wave system (2DDSWWS), was constructed by applying the variational principle of the analytic mechanics in the Lagrange coordinates. The disadvantage is that fluid viscidity is not considered in the 2DDSWWS, which is the same as the famous Kadomtsev—Petviashvili equation and Korteweg—de Vries equation. Applying dimensional analysis, we modify the 2DDSWWS and add the term related to the fluid viscidity to the 2DDSWWS. The approximate similarity solutions of the modified 2DDSWWS (M2DDSWWS) is studied and four similarity solutions are obtained. For the perfect fluids, the coefficient of kinematic viscosity is zero, then the M2DDSWWS will degenerate to the 2DDSWWS. (general)

  6. Energy displacement function as a signature for octupole deformation in excited states

    CERN Document Server

    Raduta, A A; Ursu, I I

    2003-01-01

    Energies for three positive and three negative parity bands predicted by the extended coherent states model (ECSM) in sup 2 sup 2 sup 6 Ra are calculated and used to point out new signatures for octupole deformation in ground as well as in beta and gamma bands. A beat pattern is found by using a new displacement energy function which is more appropriate for a spectrum which exhibits large deviation from a linear J(J+1) dependence. The stability against octupole deformation is revisited from a new point of view. (authors)

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

    DEFF Research Database (Denmark)

    Nerini, Francesco Fuso; Valentini, Francesco

    2015-01-01

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

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

    Science.gov (United States)

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

    2005-07-01

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

  9. Dynamic Stochastic Analysis of Radial Displacement in Functionally Graded Thick Hollow Cylinder Using Hybrid Numerical Method and Monte Carlo Simulation

    Science.gov (United States)

    Hosseini, Seyed Mahmoud; Shahabian, Farzad

    2009-09-01

    In this article, the dynamic responses of functionally graded thick hollow cylinders are studied from stochastic view using Monte Carlo method. The FG cylinder is subjected to mechanical shock loads applied to inner surface of cylinder. The FG cylinder is assumed to be in plane strain conditions and axisymmetry conditions. To obtain the radial displacement in each point, the Navier equation in displacement form is derived using isotropic elements. To solve the problem, the combined numerical method is used (Galerkin finite element and Newmark finite difference methods). The maximum, mean and minimum values of radial displacement also variance of variation in radial displacement are calculated in various points across thickness for different values of volume fraction exponent (in mechanical properties function of FG cylinder).

  10. 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

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

    CERN Document Server

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

    2005-01-01

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

  12. Effect of water storage on tooth displacement in maxillary complete dentures

    Scientific Electronic Library Online (English)

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

    Full Text Available 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.

  13. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-15

    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.

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

    Directory of Open Access Journals (Sweden)

    D. Vrebos

    2013-06-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Sebastião do Amaral Machado , ,, ,

    2006-09-01

    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.

  17. Probing of Competitive Displacement Adsorption of Casein at Oil-in-Water Interface Using Equilibrium Force Distance Measurements.

    Science.gov (United States)

    Mahendran, V; Sangeetha, J; Philip, John

    2015-06-01

    The equilibrium force distance measurement is employed for the first time to probe the competitive and displacement adsorption of casein at an oil-water (O/W) emulsion interface that was initially adsorbed with either a diblock polymer or an anionic surfactant. A significant change in the force-distance profile was observed under the competitive displacement adsorption of casein, which is further confirmed from the hydrodynamic diameter and zeta potential measurements. A decrease in the onset of repulsion and decay length are observed on competitive adsorption of smaller size casein molecules at O/W interface. With addition of casein in PVA-vac diblock polymer stabilized emulsion, the onset of repulsion decreases from 88 to 48 nm whereas the magnitude of force increases from 1 to 19 nN. The force decay length is reduced from 10.5 to 4.5 nm upon addition of casein. Our results suggest the complete replacement of adsorbed diblock polymers by casein molecules. The hydrodynamic diameter and zeta potential measurements corroborate the casein mediated polymer displacement and the competitive adsorption of casein at the O/W interface. In the case of anionic surfactant covered O/W interfaces, casein molecules weakly associate at the interface without displacing the smaller size surfactant molecules where no significant changes in the onset repulsion and force profiles are observed. These results suggest that the casein molecules are effective displacers for replacement of adsorbed macromolecules from formulations, which has several important practical applications. PMID:25965075

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

    Science.gov (United States)

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

    2012-10-16

    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

  19. A dual-function ESPI system for the measurement of out-of-plane displacement and slope

    Science.gov (United States)

    Bhaduri, B.; Mohan, N. K.; Kothiyal, M. P.

    2006-06-01

    A dual-function ESPI system is developed for the measurement of out-of-plane displacement and its slope change. The proposed system is convenient and also efficient to switch over from an out-of-plane sensitive configuration to shearography. A difference-of-phase method with a five-step algorithm is used for speckle fringe analysis.

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

    OpenAIRE

    Eihab Fathelrahman; Amalia Davies; Stephen Davies; James Pritchett

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-11-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-01

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

  3. Inkjet-printed disposable metal complexing indicator-displacement assay for sulphide determination in water.

    Science.gov (United States)

    Ariza-Avidad, M; Agudo-Acemel, M; Salinas-Castillo, A; Capitán-Vallvey, L F

    2015-05-01

    A sulphide selective colorimetric metal complexing indicator-displacement assay has been developed using an immobilized copper(II) complex of the azo dye 1-(2-pyridylazo)-2-naphthol printed by inkjetting on a nylon support. The change in colour measured from the image of the disposable membrane acquired by a digital camera using the H coordinate of the HSV colour space as the analytical parameter is able to sense sulphide in aqueous solution at pH 7.4 with a dynamic range up to 145?M, a detection limit of 0.10?M and a precision between 2 and 11%. PMID:25892069

  4. Functional outcome and patient satisfaction after displaced intra-articular calcaneal fractures: a comparison among open, percutaneous, and nonoperative treatment.

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

    Zhang, Guoqing; Pan, Zhongming

    2011-12-01

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

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

    OpenAIRE

    Larter Steve R; Ct, Duin Adri

    2001-01-01

    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 ca...

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

    Science.gov (United States)

    2011-01-01

    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.

  8. 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

  9. Tests of dielectric model descriptions of chemical charge displacements in water

    International Nuclear Information System (INIS)

    A dielectric model of electrostatic solvation is applied to describe potentials of mean force in water along reaction paths for (a) pairing of sodium and/or chloride ions; (b) the symmetric SN2 exchange of chloride in methylchloride; (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 poor. 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 salvation of classical electrostatic interactions the dielectric models appear to perform as well as the more detailed XRISM theory

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

    Directory of Open Access Journals (Sweden)

    Eihab Fathelrahman

    2014-06-01

    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.

  11. Immiscible displacement of oil by water in a microchannel: Asymmetric flow behavior and nonlinear stability analysis of core-annular flow

    Science.gov (United States)

    Foroughi, Hooman; Abbasi, Alireza; Das, Kausik S.; Kawaji, Masahiro

    2012-02-01

    The immiscible displacement of oil by water in a circular microchannel was investigated. A fused silica microchannel with an inner diameter of 250 ?m and a length of 7 cm was initially filled with a viscous silicone oil. Only water then was injected into the channel. We describe our flow observations based on the two-dimensional images captured in the middle of the channel. The water finger displaced the oil and left an oil film on the channel wall. While the oil was being displaced at the core, the flow resistance decreased, which resulted in increases in water flow rate and inertia. Eventually, the water finger reached the channel exit and formed a core-annular flow pattern. The wavelength of the waves formed at the oil-water interface also increased with the increase in inertia. The initially symmetric interfacial waves became asymmetric with time. Also, the water core shifted from the center of the channel and left a thinner oil film on one side of the microchannel. Under all flow rates tested in this study, as long as the water was continuously injected, the water core was stable and no breakup into droplets was observed. We also discuss the flow stability based on nonlinear and linear stability analyses performed on the core-annular flow. Compared to the linear analysis, which ignores the inertia effects, the nonlinear analysis, which includes the inertia effects, predicts longer interfacial wavelengths by a factor of (1)/(1-(ao)/(2)(Wew+Weo(ao2)/(1-ao2))) where Wew and Weo are the Weber numbers of the water and the oil phases, respectively, and ao is the unperturbed water core radius made dimensionless by the channel radius.

  12. 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)

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

    DEFF Research Database (Denmark)

    Bove, Jeppe; Viberg, Bjarke

    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

  14. 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)iew)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  16. Displaced Supersymmetry

    Science.gov (United States)

    Graham, Peter W.; Kaplan, David E.; Rajendran, Surjeet; Saraswat, Prashant

    2012-07-01

    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 LH 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 ˜1-103 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 framework motivates collider searches for detector-scale displaced vertices. LHCb may be ideally suited to trigger on such events, while ATLAS and CMS may need to trigger on missing energy or multijet signatures.

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

    OpenAIRE

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

    2009-01-01

    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 ar...

  18. Functionalization of carbon nanotubes by water plasma

    International Nuclear Information System (INIS)

    Multiwall carbon nanotubes grown by plasma enhanced chemical vapour deposition were functionalized by H2O plasma treatment. Through a controlled functionalization process of the carbon nanotubes (CNTs) we were able to modify and tune their chemical reactivity, expanding the range of potential applications in the field of energy and environment. In particular, different oxygen groups were attached to the surfaces of the nanotubes (e.g. carboxyl, hydroxyl and carbonyl), which changed their physicochemical properties. In order to optimize the main operational parameters of the H2O plasma treatment, pressure and power, a Box–Wilson experimental design was adopted. Analysis of the morphology, electrochemical properties and functional groups attached to the surfaces of the CNTs allowed us to determine which treatment conditions were suitable for different applications. After water plasma treatment the specific capacitance of the nanotubes increased from 23 up to 68 F g?1 at a scan rate of 10 mV s?1. (paper)

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

    International Nuclear Information System (INIS)

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

  20. 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

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

    International Nuclear Information System (INIS)

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

  2. 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)

    M. Ghasempour

    2009-01-01

    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.

  3. Lateral displacement and rotational displacement sensor

    Science.gov (United States)

    Duden, Thomas

    2014-04-22

    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.

  4. 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)

    Michel-Ange Amorim

    2010-01-01

    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.

  5. 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)

  6. Effect of anisotropy of the surface of threshold energy displacement on the calculation of a cascade function

    International Nuclear Information System (INIS)

    The technique is developed and numerical solution of a cascade function for various directions of primary knocked-out atoms moving in monocrystals and amorphous substances is carried out. It is shown that in the first case the function depends on the direction of PVA escape and is of oscillating character, which is caused by the surface anisotropy of the shift threshold energy. In case of amorphous substances the results obtained are approximated by the analytical expression

  7. A molecular density functional theory to study solvation in water

    CERN Document Server

    Jeanmairet, Guillaume

    2014-01-01

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

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

    LENUS (Irish Health Repository)

    Good, Daniel W

    2012-08-01

    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.

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

    International Nuclear Information System (INIS)

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

  10. Structure and dynamics of water inside endohedrally functionalized carbon nanotubes

    Science.gov (United States)

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

    2014-05-01

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

  11. 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

  12. 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)

    GjØrup, Caroline; Zerahn, B.

    2010-01-01

    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

  13. Water transport through functionalized nanotubes with tunable hydrophobicity

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-14

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

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

    DEFF Research Database (Denmark)

    Karunarathna, Anurudda Kumara; Kawamoto, Ken

    2010-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    ???

    2012-08-01

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

  16. Modelling Toehold-Mediated RNA Strand Displacement

    Science.gov (United States)

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

    2015-03-01

    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.

  17. Modelling toehold-mediated RNA strand displacement

    CERN Document Server

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

    2014-01-01

    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.

  18. Water distribution function across the curved lipid bilayer: SANS study

    International Nuclear Information System (INIS)

    The neutron scattering length density across the membrane is simulated on the basis of fluctuated model of lipid bilayer. The use of a separated form factors method has been applied for the identification of the structural features of the polydispersed unilamellar DMPC vesicle system. The hydration of vesicle is described by sigmoid distribution function of the water molecules. The application of the model to the obtained SANS spectra allow the determination of the main parameters of the system, such as the average vesicle radius (and its polydispersity), the membrane thickness, the thickness of hydrocarbon chain region, the number of water molecules located per lipid molecule, and the phospholipid surface area. Moreover the approach allow the calculation of some relevant parameters connected with the water distribution function across the bilayer system. The main features of the obtained results furnish an explanation of why lipid membrane is easily penetrated by the water molecules of the solution

  19. Displacer rod for use in a mechanical spectral shift reactor

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    LeBihan, Denis

    2007-04-01

    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'.

  1. Characterization of silica-functionalized carbon nanotubes dispersed in water

    International Nuclear Information System (INIS)

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

  2. The electronic structure of liquid water within density functional theory

    CERN Document Server

    Prendergast, D; Galli, G; Prendergast, David; Grossman, Jeffrey C.; Galli, Giulia

    2005-01-01

    In the last decade, computational studies of liquid water have mostly concentrated on ground state properties. However recent spectroscopic measurements have been used to infer the structure of water, and the interpretation of optical and x-ray spectra requires accurate theoretical models of excited electronic states, not only of the ground state. To this end, we investigate the electronic properties of water at ambient conditions using ab initio density functional theory within the generalized gradient approximation (DFT/GGA), focussing on the unoccupied subspace of Kohn-Sham eigenstates. We generate long (250 ps) classical trajectories for large supercells, up to 256 molecules, from which uncorrelated configurations of water molecules are extracted for use in DFT/GGA calculations of the electronic structure. We find that the density of occupied states of this molecular liquid is well described with 32 molecule supercells using a single k-point (k = 0) to approximate integration over the first Brillouin zone...

  3. Effects of Bridge Functions on Radial Distribution Functions of Liquid Water

    CERN Document Server

    Tanaka, Shigenori

    2014-01-01

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

  4. Internal Displacement Monitoring Centre

    Science.gov (United States)

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

  5. Etiopathogenesis of abomasal displacement in cattle

    Directory of Open Access Journals (Sweden)

    Šamanc Horea

    2003-01-01

    Full Text Available Abomasal displacement presents topographic gastropathy, where this organ has changed its position, and there is simultaneous dilatation which can vary in intensity. The incidence of this disorder in herds of high-yield dairy cows varies to a great degree (1 to 18 %. Abomasal displacement was established in herds of East-Frisian cows in 1 to 3% animals, and in Holstein cow herds in 5 to 18 % animals. The most frequent abomasal displacement is to the left (88%. There is significant seasonal variation in the incidence of abomasal displacement. About two-thirds of cases of abomasal displacement are diagnosed from October until April. The disorder appears more frequently in cows with repeated lactations. It has been established that it appears after the first calving in 27.8% cases, after the second to fifth calving in 66.7% cases, and after the sixth and seventh calving in 5.5% of the cows. The response of endocrine pancreas B-cells for insulin secretion to hyperglycaemia caused by applying an excess-glucose test is reduced in cows with left abomasal displacement, and there is constant hyperglycaemia in cows with right abomasal displacement. The excess-glucose test indicates a disrupted function of the endocrine pancreas in diseased animals. It has been determined through examinations of Aml genotypes in Holstein cow herds in connection with the appearance of abomasal displacement, that the occurrence of this disorder cannot be attributed to a genetic predisposition.

  6. Function and biotechnology of extremophilic enzymes in low water activity

    Directory of Open Access Journals (Sweden)

    Karan Ram

    2012-02-01

    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.

  7. Viscous stabilization of 2D drainage displacements with trapping

    OpenAIRE

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

    1999-01-01

    We investigate the stabilization mechanisms due to viscous forces in the invasion front during 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 varies almost linearly as function of height separation in the direction of the displacement. The numerical result supports arguments taking into account the loopless displacement patt...

  8. Functional diversity in three Mediterranean transitional water ecosystems

    Science.gov (United States)

    Sigala, Kalliopi; Reizopoulou, Sofia; Basset, Alberto; Nicolaidou, Artemis

    2012-09-01

    Biological trait analysis (BTA) is a method that describes ecological functioning of species assemblages incorporating information on species' distributions and their biological characteristics. In the present study, soft bottom communities of three Mediterranean coastal lagoons with different degree of salinity range were analyzed for seven biological traits (mobility, habitat, feeding type, habitat modification, body form, body size and feeding apparatus) in order to investigate the differences in communities' structure and functional diversity across a scale of natural stress. In more variable environments semi-mobile and epibenthic organisms prevailed, while predators were found under more stable conditions. Multivariate analyses using biological traits gave similar results with those obtained by the traditional analyses using species abundances; however, the distinction among lagoons was less evident, indicating that in transitional waters species can be different but their biological traits similar. This supports the idea of species redundancy in transitional water ecosystems.

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

    Science.gov (United States)

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

    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.

  10. Time-dependent Displaced and Squeezed Number States

    CERN Document Server

    Kim, S P

    2004-01-01

    We generalize the wave functions of the displaced and squeezed number states, found by Nieto, to a time-dependent harmonic oscillator with variable mass and frequency. These time-dependent displaced and squeezed number states are obtained by first squeezing and then displacing the exact number states and are exact solutions of the Schr\\"{o}dinger equation. Further, these wave functions are the time-dependent squeezed harmonic-oscillator wave functions centered at classical trajectories.

  11. Time-dependent Displaced and Squeezed Number States

    OpenAIRE

    kim, Sang Pyo

    2003-01-01

    We generalize the wave functions of the displaced and squeezed number states, found by Nieto, to a time-dependent harmonic oscillator with variable mass and frequency. These time-dependent displaced and squeezed number states are obtained by first squeezing and then displacing the exact number states and are exact solutions of the Schr\\"{o}dinger equation. Further, these wave functions are the time-dependent squeezed harmonic-oscillator wave functions centered at classical t...

  12. Advanced Triangulation Displacement Sensors

    Science.gov (United States)

    Poteet, Wade M.; Cauthen, Harold K.

    1996-01-01

    Advanced optoelectronic triangulation displacement sensors undergoing development. Highly miniaturized, more stable, more accurate, and relatively easy to use. Incorporate wideband electronic circuits suitable for real-time monitoring and control of displacements. Measurements expected to be accurate to within nanometers. In principle, sensors mass-produced at relatively low unit cost. Potential applications numerous. Possible industrial application in measuring runout of rotating shaft or other moving part during fabrication in "zero-defect" manufacturing system, in which measured runout automatically corrected.

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

    International Nuclear Information System (INIS)

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

  14. 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

  15. 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)

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

    1593-15-01

    Full Text Available 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.

  16. Determination of point displacements in the geodetic network

    OpenAIRE

    Savšek, Simona; Ambroži?, Tomaž; Stopar, Bojan; Turk, Goran

    2006-01-01

    This paper describes the procedure for testing the statistical significance of point displacements in the geodetic network as the intermediate stage between the adjustment of respective epochs measurements and an in-depth deformation analysis. The cumulative distribution function of the test statistic, presenting the relation between the displacement and the displacement accuracy, is determined by simulations. On the basis of this cumulative distribution function a critical value of the test ...

  17. Supersymmetric Displaced Number States

    Directory of Open Access Journals (Sweden)

    Fredy R. Zypman

    2015-06-01

    Full Text Available We introduce, generate and study a family of supersymmetric displaced number states (SDNS that can be considered generalized coherent states of the supersymmetric harmonic oscillator. The family is created from the seminal supersymmetric boson-fermion entangling annihilation operator introduced by Aragone and Zypman and later expanded by Kornbluth and Zypman. Using the momentum representation, the states are obtained analytically in compact form as displaced supersymmetric number states. We study their position-momentum uncertainties, and their bunchiness by classifying them according to their Mandel Q-parameter in phase space. We were also able to find closed form analytical representations in the space and number basis.

  18. 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)

    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

    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)

  19. Production Functions for Water Delivery Systems: Analysis and Estimation Using Dual Cost Function and Implicit Price Specifications

    Science.gov (United States)

    Teeples, Ronald; Glyer, David

    1987-05-01

    Both policy and technical analysis of water delivery systems have been based on cost functions that are inconsistent with or are incomplete representations of the neoclassical production functions of economics. We present a full-featured production function model of water delivery which can be estimated from a multiproduct, dual cost function. The model features implicit prices for own-water inputs and is implemented as a jointly estimated system of input share equations and a translog cost function. Likelihood ratio tests are performed showing that a minimally constrained, full-featured production function is a necessary specification of the water delivery operations in our sample. This, plus the model's highly efficient and economically correct parameter estimates, confirms the usefulness of a production function approach to modeling the economic activities of water delivery systems.

  20. The Reliability of a Functional Agility Test for Water Polo

    Directory of Open Access Journals (Sweden)

    Tucher Guilherme

    2014-07-01

    Full Text Available 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.

  1. Piezoelectric displacement in ceramics

    International Nuclear Information System (INIS)

    This Good Practice Guide is intended to aid a user to perform displacement measurements on piezoelectric ceramic materials such as PZT (lead zirconium titanate) in either monolithic or multilayer form. The various measurement issues that the user must consider are addressed, and good measurement practise is described for the four most suitable methods. (author)

  2. 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).

  3. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

    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)

  5. Groundwater resources monitoring and population displacement in northern Uganda

    Science.gov (United States)

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

    2009-04-01

    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.

  6. Shore line displacement in Oeregrundsgrepen

    International Nuclear Information System (INIS)

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

  7. Shore line displacement in Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Brydsten, Lars [Umeaa Univ. (Sweden). Dept. of Ecology and Environmental Science

    1999-12-15

    This report is a part of the SKB project 'SAFE' (Safety Assessment of the Final Repository of Radioactive Operational Waste). The aim of project SAFE is to update the previous safety analysis of SFR-1. The analysis is to be presented to the Swedish authorities not later than the end of 2000. SFR-1 is a facility for disposal of low and intermediate level radioactive waste and is situated in bedrock beneath the Baltic Sea, 1 km off the coast near the Forsmark nuclear power plant in Northern Uppland. The shore displacement in the Oeregrundsgrepen area is at present approximately 60 cm per 100 years and is slowly decreasing, but will still be substantial for many thousands of years. Since Oeregrundsgrepen is a relatively shallow part of the Bothnian Sea, the positive shore displacement will greatly effect the proportions of land and sea in the future. Within 2000 years (4000 AD) half of the current water area in Oeregrundsgrepen will be land and the water volume will be decreased with two thirds. At 7000 AD, the whole Oeregrundsgrepen area will be without brackish water. The effects on the landscape evolution due to shore displacement in the Oeregrundsgrepen area are illustrated in a chronological series of digital maps in Power Point format available saved on the supplied CD-rom and entitled 'Elevation.ppt '. The bedrock tectonics in the area are in two dominating directions: one northern that can be seen in the west shoreline of the island Graesoe and one in a north-westerly direction seen in the shoreline of the mainland. Many of the large basins that will be established in the area due to the shore displacement will be elongated in one of these directions. Some of the basins are relatively shallow and therefore probably will be totally filled with organic rich sediments and will form peat or bogs. Other basins, especially Graesoeraennan (the deep channel on the west side of Graesoe) are deep basins and will form a long chain of deep lakes. One of the deeper basins will be formed close to the SFR-1. The catchment to this former lake constitutes the inner model area that is studied in more detail. The landscape evolution in this area is also illustrated as a time series of digital maps in Power Point format 'Elev{sub i}nre.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 m{sup 2} )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.

  8. Displacement and Velocity Ratios

    Science.gov (United States)

    Bourassa, James

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

  9. Fiber Optic Displacement Sensor with New Reflectivity Compensation Method

    OpenAIRE

    Ansgar Wego; Gundolf Geske

    2013-01-01

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

  10. Genetics of bovine abomasal displacement.

    Science.gov (United States)

    Zerbin, Ina; Lehner, Stefanie; Distl, Ottmar

    2015-04-01

    Displacement of the abomasum (DA) is a common inherited condition in Holstein cows. This article reviews the genetics of DA including risk factors, genetic parameters and molecular genetic results. Breeds other than Holsteins affected by DA include Guernseys, Jerseys, Brown Swiss, Ayrshires and Simmental-Red Holsteins. In most DA cases, left displacements of the abomasum (LDA) are seen. Lactation incidence rates are higher for DA in first lactation Holsteins compared to later lactations. For Holstein cows, heritability estimates for DA are between 0.03 and 0.53. Genetic correlation estimates among DA and milk production traits range from positive to negative. Genome-wide significant genomic regions associated with LDA are located on bovine chromosomes (BTA) 1, 3, 11, 20 and 23. Motilin-associated single nucleotide polymorphisms on BTA23 exhibit a functional relationship with LDA. Pathways for deposition of calcium, insulin-dependent diabetes mellitus and synaptic transmission are significantly related to LDA in Holsteins. Deciphering the DA-associated genomic regions and genes may be an important step in the quest to understand the underlying disease-causing mechanisms and in unravelling mutations with a causal relationship to DA. PMID:25840863

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

    International Nuclear Information System (INIS)

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

  12. A displacement-doubling prism

    International Nuclear Information System (INIS)

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

  13. An improved displacement damage monitor

    International Nuclear Information System (INIS)

    A frequency-domain technique for measuring carrier lifetime in GaAs LED displacement damage monitors capable of high sensitivity and repeatability has been developed. Applications of this technique are described, including the determination of displacement energy threshold in GaAs. The minimum electron energy for displacement damage has been measured as 270 ± 15 keV, corresponding to a threshold atomic displacement energy of 10.0 ± 0.7 eV, assuming the defect is a displaced arsenic atom

  14. Rapid In Situ Identification of Source Water and Leaf Water in a Variety of Plant Species and Functional Types

    Science.gov (United States)

    Still, C. J.; Hu, J.; Berkelhammer, M. B.; Barnard, H. R.; Rahn, T.; Hsiao, G.; Raudzens Bailey, A.; Noone, D. C.

    2011-12-01

    Plant rooting distributions and use of soil water resources are important determinants of ecological and hydrological function. The isotope composition of plant xylem water can be used to infer soil water source variations, in particular differences among species and plant functional types. We report here on dynamics in the oxygen and hydrogen isotope composition of plant and soil water pools and fluxes within the Manitou Experimental Forest in the Colorado Rockies. For this work, we used multiple in situ laser-based spectroscopic analyzers to collect isotope data on soil water, leaf water, stem water, transpiration water, and canopy vapor from multiple heights in the canopy. Using an Induction Module - Cavity Ring-Down Spectroscopy system, which extracts and analyzes soil and plant samples in a few minutes, we measured soil and plant water isotopic composition from multiple soil depths and plant species at several points throughout the growing season. Stem (source) water isotopic composition varied greatly among the various plant species and functional types (pine trees, shrubs, forbs, grasses), broadly in agreement with expected plant rooting depths. The steady-state isotopic composition of leaf transpiration, another proxy of source water, was also consistent with this variation by plant functional type and rooting depth. Leaf water generally followed these patterns, but pine needles exhibited dramatic isotopic gradients along the needle length, with hydrogen isotope gradients of close to 100 per mil from leaf base to tip. We also introduced an isotopic label in two pines of different sizes (that were previously instrumented with sapflow probes and dendrometers) to further identify the pathways and pace of water flow though the trees. These results demonstrate the complex interactions between multiple source and fluxes of water, and that simple ecosystem isotope models, while generally valid, require careful evaluation as high-frequency and in situ isotopic data become more widely available.

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

    CERN Document Server

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  17. Fiber optic multimode displacement sensor

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, K.A.; Jarzynski, J. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States)

    1996-04-01

    An underwater Optical Motion Sensor (OMS) based on a design first presented by W. B. Spillman, {ital Schlieren} {ital multimode} {ital fiber}-{ital optic} {ital hydrophone}, Applied Physics Letters 37(2), 15 July 1980, p. 145{endash}146 is described. The displacement sensor uses the same acoustooptical intensity modulation mechanism as Spillman, however the sensing mechanism is isolated from the ambient fluid environment by a small cylindrical aluminum enclosure (1{double_prime} OD{times}3/4{double_prime}). The enclosure contains an inertial mass and the fiber collimators. The inertial mass is suspended in the center of the enclosure by three small wires rigidly mounted to the walls. The mass and wires act as a cantilever beam system with a mechanical resonance near 100 Hz. The transduction mechanism consists of two opposed optical gratings aligned and positioned between the fiber collimators. One grating is mounted on the inertial mass while the other is mounted on the lower end cap of the enclosure. Relative motion between the gratings causes a modulation of the light transmitted through the gratings. The modulated beam is focused onto a photodetector and converted to electric current. The frequency response is flat from 200 Hz{endash}9 kHz with a minimum detectable displacement of 0.002 A and the dynamic range is 136 dB. The small size and light weight give the sensor an effective density of 1.08 g/cm{sup 3} making it almost neutrally buoyant in water. This in conjunction with the performance characteristics make this sensor suitable for use in acoustical sensing applications. {copyright} {ital 1996 American Institute of Physics.}

  18. Displacement Parameter Inversion for a Novel Electromagnetic Underground Displacement Sensor

    Directory of Open Access Journals (Sweden)

    Nanying Shentu

    2014-05-01

    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.

  19. Measuring vulnerability to disaster displacement

    Science.gov (United States)

    Brink, Susan A.; Khazai, Bijan; Power, Christopher; Wenzel, Friedemann

    2015-04-01

    Large scale disasters can cause devastating impacts in terms of population displacement. Between 2008 and 2013, on average 27 million people were displaced annually by disasters (Yonetani 2014). After large events such as hurricane Katrina or the Port-au-Prince earthquake, images of inadequate public shelter and concerns about large scale and often inequitable migration have been broadcast around the world. Population displacement can often be one of the most devastating and visible impacts of a natural disaster. Despite the importance of population displacement in disaster events, measures to understand the socio-economic vulnerability of a community often use broad metrics to estimate the total socio-economic risk of an event rather than focusing on the specific impacts that a community faces in a disaster. Population displacement is complex and multi-causal with the physical impact of a disaster interacting with vulnerability arising from the response, environmental issues (e.g., weather), cultural concerns (e.g., expectations of adequate shelter), and many individual factors (e.g., mobility, risk perception). In addition to the complexity of the causes, population displacement is difficult to measure because of the wide variety of different terms and definitions and its multi-dimensional nature. When we speak of severe population displacement, we may refer to a large number of displaced people, an extended length of displacement or associated difficulties such as poor shelter quality, risk of violence and crime in shelter communities, discrimination in aid, a lack of access to employment or other difficulties that can be associated with large scale population displacement. We have completed a thorough review of the literature on disaster population displacement. Research has been conducted on historic events to understand the types of negative impacts associated with population displacement and also the vulnerability of different groups to these impacts. We aggregate these ideas into a framework of disaster displacement vulnerability that distinguishes between three main aspects of disaster displacement. Disaster displacement can be considered in terms of the number of displaced people and the length of that displacement. However, the literature emphasizes that the severity of disaster displacement can not be measured completely in quantitative terms. Thus, we include a measure representing people who are trapped and unable to leave their homes due to mobility, resources or for other reasons. Finally the third main aspect considers the difficulties that are associated with displacement and reflects the difference between the experiences of those who are displaced into safe and supportive environments as compared to those whose only alternate shelter is dangerous and inadequate for their needs. Finally, we apply the framework to demonstrate a methodology to estimate vulnerability to disaster displacement. Using data from the Global Earthquake Model (GEM) Social and Economic Vulnerability sub-National Database, we generate an index to measure the vulnerability of Japanese prefectures to the dimensions of displacement included in the framework. References Yonitani, M. (2014). Global Estimates 2014: People displaced by disasters. http://www.internal-displacement.org/publications/2014/global-estimates-2014-people-displaced-by-disasters/

  20. Feature displacement interpolation

    DEFF Research Database (Denmark)

    Nielsen, Mads; Andresen, Per RØnsholt

    1998-01-01

    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.

  1. Strategies for displacing oil

    Science.gov (United States)

    Rao, Vikram; Gupta, Raghubir

    2015-03-01

    Oil currently holds a monopoly on transportation fuels. Until recently biofuels were seen as the means to break this stranglehold. They will still have a part to play, but the lead role has been handed to natural gas, almost solely due to the increased availability of shale gas. The spread between oil and gas prices, unprecedented in its scale and duration, will cause a secular shift away from oil as a raw material. In the transport fuel sector, natural gas will gain traction first in the displacement of diesel fuel. Substantial innovation is occurring in the methods of producing liquid fuel from shale gas at the well site, in particular in the development of small scale distributed processes. In some cases, the financing of such small-scale plants may require new business models.

  2. Job displacement penalties in Japan

    OpenAIRE

    Bognanno, Michael; Delgado, Lisa

    2005-01-01

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

  3. Point Coupled Displacement Sensor Project

    National Aeronautics and Space Administration — Real-time displacement measurement techniques are needed to acquire aerodynamic and structural system characteristics in flight. This proposal describes the...

  4. 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)

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

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

  5. 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)

  6. The Reconstruction of Functioning of the Water Supply System in Ferrari's Garden in Štanjel

    OpenAIRE

    Andoljs?ek, Andrej

    2006-01-01

    The graduation thesis describes the reconstruction of functioning of the water supply system in Ferrari’s garden in Štanjel. The first part of thesis deals with methods and devices for detecting waterwork elements and losses on water supply systems. Further on are described different modes of functioning of devices and methods, interpretation of results and how was each method used at the water supply system reconstruction. The second part describes the course of reconstruction in fieldwor...

  7. Novel water overlayer growth on Pd(111) characterized with scanning tunneling microscopy and density functional theory

    OpenAIRE

    Cerda, J.; Michaelides, A.; Bocquet, M. L.; Feibelman, P. J.; Mitsui, T.; ROSE, M; Fomin, E.; Salmeron, M.

    2004-01-01

    Scanning tunneling microscopy (STM) images of water submonolayers on Pd(111) reveal quasiperiodic and isolated adclusters with internal structure that would ordinarily be ascribed to icelike puckered hexagonal units. However, density functional theory and STM simulations contradict this conventional picture, showing instead that the water adlayers are composed mainly of flat-lying molecules arranged in planar water hexagons. A new rule for two dimensional (2D) water growth is offered that gen...

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

    OpenAIRE

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

    2011-01-01

    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 an...

  9. Ko Displacement Theory for Structural Shape Predictions

    Science.gov (United States)

    Ko, William L.

    2010-01-01

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

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

    OpenAIRE

    Song, Yutong

    2012-01-01

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

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

    Science.gov (United States)

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

    2012-12-01

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

  12. Aquaporin structure-function relationships: water flow through plant living cells.

    Science.gov (United States)

    Zhao, Chang-Xing; Shao, Hong-Bo; Chu, Li-Ye

    2008-04-01

    Plant aquaporins play an important role in water uptake and movement-an aquaporin that opens and closes a gate that regulates water movement in and out of cells. Some plant aquaporins also play an important role in response to water stress. Since their discovery, advancing knowledge of their structures and properties led to an understanding of the basic features of the water transport mechanism and increased illumination to water relations. Meanwhile, molecular and functional characterization of aquaporins has revealed the significance of their regulation in response to the adverse environments such as salinity and drought. This paper reviews the structure, species diversity, physiology function, regulation of plant aquaporins, and the relations between environmental factors and plant aquaporins. Complete understanding of aquaporin function and regulation is to integrate those mechanisms in time and space and to well regulate the permeation of water across biological membranes under changing environmental and developmental conditions. PMID:18063350

  13. 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

  14. Zion service water system: Can it perform its safety function?

    International Nuclear Information System (INIS)

    The Zion station's service water system (SWS) has a safety-related portion designed to remove heat from components and intermediate systems during all modes of operation. This safety-related portion, including pumps and heat exchangers, was designed to remove design-basis accident heat loads with very limiting (or very high) Lake Michigan water temperature. During daily operation, with significantly cooler Lake Michigan water, the heat exchangers can easily remove the heat as required by the normal operation of various components and systems. A significant question has recently been prompted by the SWS impending generic letter: can the safety-related portion of the Zion SWS remove the required heat loads given design-basis accident conditions? Commonwealth Edison Company (CECo) and Zion station are in the process of determining the answer. This paper first describes the Zion SWS and then discusses the actions being taken by CECo to determine the status of their SWS

  15. Woody plant willow in function of river water protection

    Directory of Open Access Journals (Sweden)

    Babincev Ljiljana M.

    2011-01-01

    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.

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

    OpenAIRE

    Martins, Rita; Fortunato, Adelino; Coelho, Fernando

    2006-01-01

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

  17. A Measuring Method for Angular Displacement Based on Correlation Algorithm

    Directory of Open Access Journals (Sweden)

    Ping Yan

    2012-10-01

    Full Text Available The existing angular displacement measurement methods rely on the manufacturing precision of the fixed-plate and moving-plate with high manufacturing cost, and it is difficult to overcome a static error and drift for the static measurement method. A kind of angular displacement measuring method based on correlation algorithm is presented with the characteristics of a low manufacturing cost, high precision, anti-noise and anti-partially damaged properties and so on. The method is that firstly full circle broadband or white noise, random data is a pre-prepared coaxially in a rotating body, then the periodic random signal is continuously formed using pickup head reads this data in the basic uniform rotation process of the rotating body. The instantaneous angular displacement of the pickup head relative to the rotating body is obtained by means of the correlation operations between the periodic random signal and the signal sequence of pre-stored data. The angular displacement among the different pickup heads is gained by subtraction for the instantaneous angular displacement of different pickup heads relative to the rotating body at the same instant. The functional relationship between the relative angular displacement of the different pickup heads and the measured angular displacement is determined by linkage equations, which is used to calculate the measured angular displacement. Furthermore, the schematics of detective devices and the principle of the signal processing are developed to implement the method.

  18. 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

  19. Functional polyelectrolyte multilayer membranes for water purification applications

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  20. OIL DISPLACEMENT IN MISCIBLE CONDITION

    Directory of Open Access Journals (Sweden)

    Ivanka Juttner

    1997-12-01

    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.

  1. 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)

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

    1999-02-01

    Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and {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.)

  2. Hysteresis of Soil Point Water Retention Functions Determined by Neutron Radiography

    Science.gov (United States)

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

    2010-12-01

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

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

    Science.gov (United States)

    Rani, Pooja; Biswas, Parbati

    2014-08-01

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

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

    International Nuclear Information System (INIS)

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

  5. Displacement sensing system and method

    Science.gov (United States)

    VunKannon, Jr., Robert S

    2006-08-08

    A displacement sensing system and method addresses demanding requirements for high precision sensing of displacement of a shaft, for use typically in a linear electro-dynamic machine, having low failure rates over multi-year unattended operation in hostile environments. Applications include outer space travel by spacecraft having high-temperature, sealed environments without opportunity for servicing over many years of operation. The displacement sensing system uses a three coil sensor configuration, including a reference and sense coils, to provide a pair of ratio-metric signals, which are inputted into a synchronous comparison circuit, which is synchronously processed for a resultant displacement determination. The pair of ratio-metric signals are similarly affected by environmental conditions so that the comparison circuit is able to subtract or nullify environmental conditions that would otherwise cause changes in accuracy to occur.

  6. Function and biotechnology of extremophilic enzymes in low water activity

    OpenAIRE

    Karan Ram; Capes Melinda D; DasSarma Shiladitya

    2012-01-01

    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 ...

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

    Directory of Open Access Journals (Sweden)

    ABC Oliveira

    2006-01-01

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

  8. Charge-displacement analysis for excited states

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  9. Measurement of the Cryomodule cold mass displacement using the WPM

    International Nuclear Information System (INIS)

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

  10. Radionuclide migration as a function of the quality of irrigation water

    International Nuclear Information System (INIS)

    The depth migration of radionuclides (137Cs, 54Mn, 60Co) and their different chemical forms available as a function of the quality of the irrigation water were investigated in two types of soils. The notion of irrigation water quality should be introduced in order to assess the potential radioactive contamination of soils

  11. Dynamics of confined water reconstructed from inelastic x-ray scattering measurements of bulk response functions

    Science.gov (United States)

    Coridan, Robert H.; Schmidt, Nathan W.; Lai, Ghee Hwee; Abbamonte, Peter; Wong, Gerard C. L.

    2012-03-01

    Nanoconfined water and surface-structured water impacts a broad range of fields. For water confined between hydrophilic surfaces, measurements and simulations have shown conflicting results ranging from “liquidlike” to “solidlike” behavior, from bulklike water viscosity to viscosity orders of magnitude higher. Here, we investigate how a homogeneous fluid behaves under nanoconfinement using its bulk response function: The Green's function of water extracted from a library of S(q,?) inelastic x-ray scattering data is used to make femtosecond movies of nanoconfined water. Between two confining surfaces, the structure undergoes drastic changes as a function of surface separation. For surface separations of ?9 Å, although the surface-associated hydration layers are highly deformed, they are separated by a layer of bulklike water. For separations of ?6 Å, the two surface-associated hydration layers are forced to reconstruct into a single layer that modulates between localized “frozen’ and delocalized “melted” structures due to interference of density fields. These results potentially reconcile recent conflicting experiments. Importantly, we find a different delocalized wetting regime for nanoconfined water between surfaces with high spatial frequency charge densities, where water is organized into delocalized hydration layers instead of localized hydration shells, and are strongly resistant to `freezing' down to molecular distances (<6 Å).

  12. Dynamics of stable viscous displacement in porous media

    OpenAIRE

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

    1999-01-01

    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 to the viscous forces in the liquids. We find that the capillary pressure difference between two different points along the front varies almost linearly as function of height separation in the direction of the displacement. The numerical results support arguments that dif...

  13. 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 disprmal 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

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

    Science.gov (United States)

    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

    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.

  15. Conversion function between the Linke turbidity and the atmospheric water vapor and aerosol content

    OpenAIRE

    Ineichen, Pierre

    2008-01-01

    This technical note presents a conversion function between the widely used Linke turbidity coefficient TL, the atmospheric water vapor and urban aerosol content. It takes into account the altitude of the application site. The function is based on radiative transfer calculations and validated with the help of an independent clear sky model. Its precision is around 0.12 units of TL.

  16. Digital image correlation: displacement accuracy estimation

    Directory of Open Access Journals (Sweden)

    Wattrisse B.

    2010-06-01

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

  17. Functional groups in North Chilean desert shrub species, based on the water sources used

    International Nuclear Information System (INIS)

    Primary productivity and vegetation structure in arid ecosystems are determined by water availability. In studies conducted in the coastal dry land of North Central Chile (29 degrees 43'S; 71degrees 14'0, 300m), the mechanisms to use different water sources by shrubs species, in two contrasting rainfall years were compared. Information on pheno logical studies, root architecture and water sources used by shrubs through the use of stable isotopes is are discussed. Six functional groups based on water uptake and water use are recognized. The functional groups were defined based on their habits (deciduous and evergreen), their root systems, (shallow, dimorphic and deep), and their ability to use different water sources (surficial and/or deep). Because of the differential impact of the goat overgrazing on different functional groups, this would result on a lower utilization of surficial waters. A management and/or restoration plan should maximize the use of all water sources available to recover the primary productivity and the system stability

  18. A multi-functional oil-water separator from a selectively pre-wetted superamphiphobic paper.

    Science.gov (United States)

    Ge, Dengteng; Yang, Lili; Wang, Chenbo; Lee, Elaine; Zhang, Yongquan; Yang, Shu

    2015-04-11

    A multi-functional oil-water separator is prepared from a paper towel spray coated with superamphiphobic (i.e., superhydrophobic and superoleophobic) nanoparticles. After the separator is pre-wetted with ethanol, followed by water, water can be removed from the light oil-water mixture and emulsions by gravity with high separation efficiency (99.9%) and separation flux. Vice versa, heavy oil can be removed by gravity on an ethanol-oil pre-wetted SA-paper. PMID:25750982

  19. Asymmetry in Reproductive Character Displacement

    Directory of Open Access Journals (Sweden)

    Jang, Yikweon

    2008-11-01

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

  20. 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

  1. Establishing a water isotope framework for investigating ecosystem functioning and agricultural water use in central Kenya

    Science.gov (United States)

    Soderberg, K.; Gitonga, J. M.; Caylor, K. K.

    2012-12-01

    Central Kenya is a region with a steep precipitation gradient, strong seasonality, and large inter-annual variability. Population and development pressures are raising questions about the sustainability of water supplies, necessitating a better basic understanding of regional hydrology. Here we present two years (2010-2012) of isotope data (?2H, ?18O) for various water, soil and plant samples from Laikipia in Central Kenya. The samples were collected in support of evapotranspiration partitioning research at an eddy covariance flux tower located at Mpala Research Center. However, these results can be more widely useful in that they provide a framework for understanding short and long-term variability in the isotopic composition of various components of the hydrologic cycle. Through event-scale sampling of rain events, we have found a similar local meteoric water line, but with significantly more enriched precipitation compared with the long-term GNIP sites in Kenya. Boreholes, springs and streams were sampled periodically and reveal some distinct water sources in the region. Woody plant stem water isotopic composition tends to be more depleted than volume-averaged local rainfall, suggesting recharge in the root zone from highly depleted precipitation events. However, during the study period there was no significant correlation between isotopic composition and rain depth or rain rate.

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

    CERN Document Server

    Jeanmairet, Guillaume; Sergiievskyi, Volodymyr; Borgis, Daniel

    2015-01-01

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

  3. Health, safe water and sanitation: a cross-sectional health production function for central Java, Indonesia.

    OpenAIRE

    Wibowo, D.; Tisdell, C.

    1993-01-01

    The study describes the development of health production functions and their application in the evaluation of the health impacts of investments in safe water and sanitation. For this purpose, data on the morbidity of waterborne diseases and diarrhoea were collected from medical records in the province of Central Java, Indonesia. A reciprocal production function was found to fit the data best. The health production functions exhibit constant return to scale, i.e., a simultaneous m-fold increas...

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

    Science.gov (United States)

    Toon, Katherine P.; Lovell, Randal W.

    2010-01-01

    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.

  5. 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.

  6. Fiber Optic Displacement Sensor with New Reflectivity Compensation Method

    Directory of Open Access Journals (Sweden)

    Ansgar Wego

    2013-06-01

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

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

    Science.gov (United States)

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

    2013-04-01

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

  8. Particle displacement tracking for PIV

    Science.gov (United States)

    Wernet, Mark P.

    1990-01-01

    A new Particle Imaging Velocimetry (PIV) data acquisition and analysis system, which is an order of magnitude faster than any previously proposed system has been constructed and tested. The new Particle Displacement Tracing (PDT) system is an all electronic technique employing a video camera and a large memory buffer frame-grabber board. Using a simple encoding scheme, a time sequence of single exposure images are time coded into a single image and then processed to track particle displacements and determine velocity vectors. Application of the PDT technique to a counter-rotating vortex flow produced over 1100 velocity vectors in 110 seconds when processed on an 80386 PC.

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

    DEFF Research Database (Denmark)

    Battilani, Adriano; Steiner, Michele

    2010-01-01

    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.

  10. Regeneration of strong-base anion-exchange resins by sequential chemical displacement

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Gilbert M. (Knoxville, TN); Gu, Baohua (Oak Ridge, TN); Moyer, Bruce A. (Oak Ridge, TN); Bonnesen, Peter V. (Knoxville, TN)

    2002-01-01

    A method for regenerating strong-base anion exchange resins utilizing a sequential chemical displacement technique with new regenerant formulation. The new first regenerant solution is composed of a mixture of ferric chloride, a water-miscible organic solvent, hydrochloric acid, and water in which tetrachloroferrate anion is formed and used to displace the target anions on the resin. The second regenerant is composed of a dilute hydrochloric acid and is used to decompose tetrachloroferrate and elute ferric ions, thereby regenerating the resin. Alternative chemical displacement methods include: (1) displacement of target anions with fluoroborate followed by nitrate or salicylate and (2) displacement of target anions with salicylate followed by dilute hydrochloric acid. The methodology offers an improved regeneration efficiency, recovery, and waste minimization over the conventional displacement technique using sodium chloride (or a brine) or alkali metal hydroxide.

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

    Science.gov (United States)

    Gottipati, Manoj K.

    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.

  12. Chemically functionalized water-soluble single-walled carbon nanotubes modulate morpho-functional characteristics of astrocytes.

    Science.gov (United States)

    Gottipati, Manoj K; Kalinina, Irina; Bekyarova, Elena; Haddon, Robert C; Parpura, Vladimir

    2012-09-12

    We 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. PMID:22924813

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

    Science.gov (United States)

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

    2013-12-01

    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.

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

    Science.gov (United States)

    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

    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

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

    DEFF Research Database (Denmark)

    Karunarathna, Anurudda Kumara; MØldrup, Per

    2010-01-01

    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.

  16. Monitoring Changes in Moisture Load Using Elastic Displacements in the Vadose Zone

    Science.gov (United States)

    Thrash, C. J.; Murdoch, L. C.; Germanovich, L. N.; Weinberg, A.

    2014-12-01

    Monitoring changes in mass over scales of several meters to hundreds of meters or more has many applications to characterization of the Critical Zone, including assessing changes in soil moisture, erosion or deposition of sediment, and melting or accumulation of snow or ice. A technique has been developed to monitor average changes in mass on those scales using continuous high-resolution measurements of displacement made with a vertical extensometer (called a DELTA extensometer). An increase of mass above the extensometer causes the soil to contract, which causes the extensometer to function similar to a weighing lysimeter. DELTA extensometers have been deployed at field sites near Clemson, South Carolina, and in northern Texas. The extensometers in South Carolina are in saprolite derived from biotite gneiss, whereas the ones in Texas are in clayey silt underlying playas. The instruments are in the vadose zone at depths of 3m to 6m. Signals from co-located extensometers are remarkably similar, demonstrating reproducibility of the technique. The extensometers respond to loading from a person or vehicle, and this load is used to estimate the Young's modulus of soil enveloping the extensometer. Displacement during small to moderate rainfalls is typically linear with the accumulated rain (~0.2 micron/mm of rain, for example). The displacement levels out during large rainfalls, potentially due to the onset of overland flow that would limit the water load during precipitation. This suggests that the onset of overland flow could be evaluated using this technique. Seasonal temperature fluctuations at the soil surface can penetrate to the depths of the extensometers causing displacement from thermal expansion and contraction. Thermal effects account for approximately 100 ?m of displacement over an annual cycle at one instrument. It appears that much of the thermal signal can be removed by data analysis. Pore pressure changes in the vicinity of the extensometer can also affect displacement and we are currently measuring pressures in an effort to identify this component of the signal. At one of the Texas sites, a series of step-like compressions totally 100 microns accompanied several rainfalls as water accumulated and filled the playa.

  17. Energies of ions in water and nanopores within density functional theory

    Science.gov (United States)

    Leung, Kevin; Marsman, Martijn

    2007-10-01

    Accurate calculations of electrostatic potentials and treatment of substrate polarizability are critical for predicting the permeation of ions inside water-filled nanopores. The ab initio molecular dynamics method, based on density functional theory (DFT), accounts for the polarizability of materials, water, and solutes, and it should be the method of choice for predicting accurate electrostatic energies of ions. In practice, DFT coupled with the use of periodic boundary conditions in a charged system leads to large energy shifts. Results obtained using different DFT packages may vary because of the way pseudopotentials and long-range electrostatics are implemented. Using maximally localized Wannier functions, we apply robust corrections that yield relatively unambiguous ion energies in select molecular and aqueous systems and inside carbon nanotubes. Large binding energies are predicted for ions in metallic carbon nanotube arrays, while Na+ and Cl- energies are found to exhibit asymmetry in water that is smaller than but comparable with those computed using nonpolarizable water force fields.

  18. Potential energy functions for atomic-level simulations of water and organic and biomolecular systems

    OpenAIRE

    Jorgensen, William L.; Tirado-Rives, Julian

    2005-01-01

    An overview is provided on the development and status of potential energy functions that are used in atomic-level statistical mechanics and molecular dynamics simulations of water and of organic and biomolecular systems. Some topics that are considered are the form of force fields, their parameterization and performance, simulations of organic liquids, computation of free energies of hydration, universal extension for organic molecules, and choice of atomic charges. The discussion of water mo...

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

    OpenAIRE

    B. Witkowska-Walczak; C. Sławiński; M. Korus

    2007-01-01

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

  20. Testing peatland water-table depth transfer functions using high-resolution hydrological monitoring data

    Science.gov (United States)

    Swindles, Graeme T.; Holden, Joseph; Raby, Cassandra L.; Turner, T. Edward; Blundell, Antony; Charman, Dan J.; Menberu, Meseret Walle; Kløve, Bjørn

    2015-07-01

    Transfer functions are now commonly used to reconstruct past environmental variability from palaeoecological data. However, such approaches need to be critically appraised. Testate amoeba-based transfer functions are an established method for the quantitative reconstruction of past water-table variations in peatlands, and have been applied to research questions in palaeoclimatology, peatland ecohydrology and archaeology. We analysed automatically-logged peatland water-table data from dipwells located in England, Wales and Finland and a suite of three year, one year and summer water-table statistics were calculated from each location. Surface moss samples were extracted from beside each dipwell and the testate amoebae community composition was determined. Two published transfer functions were applied to the testate-amoeba data for prediction of water-table depth (England and Europe). Our results show that estimated water-table depths based on the testate amoeba community reflect directional changes, but that they are poor representations of the real mean or median water-table magnitudes for the study sites. We suggest that although testate amoeba-based reconstructions can be used to identify past shifts in peat hydrology, they cannot currently be used to establish precise hydrological baselines such as those needed to inform management and restoration of peatlands. One approach to avoid confusion with contemporary water-table determinations is to use residuals or standardised values for peatland water-table reconstructions. We contend that our test of transfer functions against independent instrumental data sets may be more powerful than relying on statistical testing alone.

  1. Energies of ions in water and nanopores within Density Functional Theory

    OpenAIRE

    Leung, Kevin; Marsman, Martijn

    2007-01-01

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

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

    Science.gov (United States)

    Toon, Katherine P.; Lovell, Randal W.

    2009-01-01

    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.

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2012-03-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-01

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

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

    OpenAIRE

    Antonioli, Barbara; Filippini, Massimo

    2005-01-01

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

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

    Science.gov (United States)

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

    2013-07-01

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

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

    OpenAIRE

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

    2010-01-01

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

  9. A fibre optic displacement sensor

    OpenAIRE

    Sohlström, Hans; Holm, Ulf

    1982-01-01

    Fibre optics is beginning to find use for sensing purposes. Fibre optic sensors have many interesting features, e.g., their immunity to interference from electromagnetic fields. The paper briefly discusses different sensor principles. A displacement sensor using multimode, step index fibres is desccribed. Measurement data showing a resolution of 0.05 nm/sqrt(Hz) in a 150 µm linear range is given. In this sensor, the light coupling between two fibre ends varies with the position of a movabl...

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

    Science.gov (United States)

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

    2015-03-15

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

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

    CERN Document Server

    Jeanmairet, Guillaume; Borgis, Daniel

    2013-01-01

    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 ...

  12. Fabrication of amine-functionalized magnetite nanoparticles for water treatment processes

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  13. 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.

  14. The thermotidal exciting function for water vapour absorption of solar radiation

    Directory of Open Access Journals (Sweden)

    M. BONAFEDE

    1976-06-01

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

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

    Science.gov (United States)

    Newman, J. C., Jr.

    1981-01-01

    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.

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

    OpenAIRE

    Belleri, Andrea; Torquati, Mauro; Riva, Paolo

    2012-01-01

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

  17. The case for character displacement in plants

    OpenAIRE

    Beans, Carolyn M

    2014-01-01

    The evidence for character displacement as a widespread response to competition is now building. This progress is largely the result of the establishment of rigorous criteria for demonstrating character displacement in the animal literature. There are, however, relatively few well-supported examples of character displacement in plants. This review explores the potential for character displacement in plants by addressing the following questions: (1) Why aren't examples of character displacemen...

  18. Towards spatially smart abatement of human pharmaceuticals in surface waters: Defining impact of sewage treatment plants on susceptible functions.

    Science.gov (United States)

    Coppens, Lieke J C; van Gils, Jos A G; Ter Laak, Thomas L; Raterman, Bernard W; van Wezel, Annemarie P

    2015-09-15

    For human pharmaceuticals, sewage treatment plants (STPs) are a major point of entry to surface waters. The receiving waters provide vital functions. Modeling the impact of STPs on susceptible functions of the surface water system allows for a spatially smart implementation of abatement options at, or in the service area of, STPs. This study was performed on a nation-wide scale for the Netherlands. Point source emissions included were 345 Dutch STPs and nine rivers from neighboring countries. The Dutch surface waters were represented by 2511 surface water units. Modeling was performed for two extreme discharge conditions. Monitoring data of 7 locations along the rivers Rhine and Meuse fall mostly within the range of modeled concentrations. Half of the abstracted volumes of raw water for drinking water production, and a quarter of the Natura 2000 areas (European Union nature protection areas) hosted by the surface waters, are influenced by STPs at low discharge. The vast majority of the total impact of all Dutch STPs during both discharge conditions can be attributed to only 19% of the STPs with regard to the drinking water function, and to 39% of the STPs with regard to the Natura 2000 function. Attributing water treatment technologies to STPs as one of the possible measures to improve water quality and protect susceptible functions can be done in a spatially smart and cost-effective way, using consumption-based detailed hydrological and water quality modeling. PMID:26102555

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

    Scientific Electronic Library Online (English)

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

    2014-01-01

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

  20. Density Functional Theory Meta-GGA+U Study of Water Incorporation in the Metal Organic Framework Material Cu-BTC

    OpenAIRE

    Cockayne, Eric; Nelson, Eric B

    2015-01-01

    Water absorption in the metal-organic framework (MOF) material Cu-BTC, up to a concentration of 3.5 H$_2$O per Cu ion, is studied via density functional theory at the meta-GGA+U level. The stable arrangements of water molecules show chains of hydrogen-bonded water molecules and a tendency to form closed cages at high concentration. Water clusters are stabilized primarily by a combination of water-water hydrogen bonding and Cu-water oxygen interactions. Stability is further e...

  1. Theoretical Investigation on the Solubilization in Water of Functionalized Single-Wall Carbon Nano tubes

    International Nuclear Information System (INIS)

    An important technique to increase the solubility and reactivity of carbon nano tube is through functionalization. In this study, the effects of functionalization of some single-walled carbon nano tubes (SWCNTs) were investigated with the aid of density functional theory. The SWCNT model used in the study consists of a finite, (5, 0) zigzag nano tube segment containing 60 C atoms with hydrogen atoms added to the dangling bonds of the perimeter carbons. There are three water-dispersible SWCNTs used in this study that were functionalized with (a) formic acid, as a model of carboxylic acid, (b) isophthalic acid, as a model aromatic dicarboxylic acid, and (c) benzenesulfonic acid, as a model aromatic sulfonic acid. Binding energies of the organic radicals to the nano tubes are calculated, as well as the HOMO-LUMO gaps and dipole moments of both nano tubes and functionalized nano tubes. Binding was found out to be thermodynamically favorable. The functionalization increases the electrical dipole moments and results in an enhancement in the solubility of the nano tubes in water manifested through favorable changes in the free energies of solvation. This should lower the toxicity of nano tubes and improve their biocompatibility.

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

    Science.gov (United States)

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

    2015-04-01

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

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

    Science.gov (United States)

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

    2015-04-01

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

  4. 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.

  5. Recovery of a boundary function by observation data in a problem for the shallow water model

    Science.gov (United States)

    Dementyeva, E.; Karepova, E.; Shaidurov, V.

    2014-11-01

    In the paper, the shallow water equations are applied to describe the propagation of long waves in the coastal area of an ocean. The boundary condition involves an additional function on the open water boundary. In general case this function is unknown. For its determination an inverse problem is considered. To close the inverse problem the observation data on elevation of the sea surface along some part of the boundary is used. In actual, the observation data may have sufficiently large gaps. To improve the conditioning of this ill-posed inverse problem a regularization functional is considered that corresponds to higher smoothness of the data involved. The problem is solved numerically using optimal control methods, adjoint operators, and finite element method. As the result, the boundary function is recovered on the whole open water boundary including observations gaps. In the paper a solvability of the inverse problem is proved and the proposed numerical method is justified. The results are illustrated by a numerical example.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  7. 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.

  8. Measurement uncertainty of a fibre-optic displacement sensor

    International Nuclear Information System (INIS)

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

  9. Topology synthesis of large-displacement compliant mechanisms

    DEFF Research Database (Denmark)

    Pedersen, Claus B. Wittendorf; Buhl, Thomas

    2001-01-01

    This paper describes the use of topology optimization as a synthesis tool for the design of large-displacement compliant mechanisms. An objective function for the synthesis of large-displacement mechanisms is proposed together with a formulation for synthesis of path-generating compliant mechanisms. The responses of the compliant mechanisms are modelled using a total Lagrangian finite element formulation, the sensitivity analysis is performed using the adjoint method and the optimization problem is solved using the method of moving asymptotes. Procedures to circumvent some numerical problems are discussed. Copyright (C) 2001 John Wiley & Sons, Ltd.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-09-01

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

  11. Characteristics of children with hip displacement in cerebral palsy

    Directory of Open Access Journals (Sweden)

    Wagner Philippe

    2007-10-01

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

  12. 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

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

    Science.gov (United States)

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

    2015-02-28

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

  14. Displacement cross sections of electron irradiated graphene and carbon nanotubes

    Science.gov (United States)

    Yan, Qiang; Wang, Jing; Chen, Di; Gigax, Jonathan; Shao, Lin

    2015-05-01

    We calculate the displacement cross-sections (DCS) of low dimensional carbon systems under electron irradiation and present an analytical formula being able to evaluate displacement creations under various conditions. The calculations consider Mott scattering, charge screening effects and thermal vibrations of target atoms. DCS values of graphene and single-walled carbon nanotubes (SWNTs) as a function of electron beam energies, substrate temperatures, and tube diameters are calculated through combination with carbon threshold displacement energies obtained from molecular dynamics simulations. For SWNTs, the smaller the tube diameters the higher the DCS values. Such diameter dependence is the most pronounced for low energy electron beams. Furthermore, DCS values are most sensitive to temperatures when electron beam energy is low. However, the temperature sensitivity disappears at higher electron energy, specifically at 200 keV and beyond.

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

    CERN Document Server

    Dehghani, A

    2014-01-01

    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...

  16. Current density and plasma displacement near perturbed rational surfaces

    International Nuclear Information System (INIS)

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

  17. Atomic displacement effects in near-edge resonant 'forbidden' reflections

    Energy Technology Data Exchange (ETDEWEB)

    Ovchinnikova, E.N. [Moscow State University, Physical Department, 119992 Moscow (Russian Federation)]. E-mail: ovtchinnikova@mtu-net.ru; Dmitrienko, V.E. [A.V. Shubnikov Institute of Crystallography, 119333 Moscow (Russian Federation)]. E-mail: dmitrien@ns.crys.ras.ru; Ishida, K. [Tokyo University of Science, Noda, Chiba 278-8510 (Japan); Kirfel, A. [Mineralogisch-Petrologisches Institut der Universitat Bonn, D-53115 Bonn (Germany); Collins, S.P. [Diamond Light Source, Rutherford Appleton Laboratory, Chilton, Didcot OX11 OQX, UK (United Kingdom); Oreshko, A.P. [A.V. Shubnikov Institute of Crystallography, 119333 Moscow (Russian Federation); Cabaret, D. [Laboratoire de Mineralogie-Cristallographie, case 115, 4 place Jussieu, 75252 Paris (France); Vedrinskii, R.V. [Rostov State University, 344090 Rostov-Don (Russian Federation); Kraizman, V.L. [Rostov State University, 344090 Rostov-Don (Russian Federation); Novakovich, A.A. [Rostov State University, 344090 Rostov-Don (Russian Federation); Krivitskii, E.V. [Rostov State University, 344090 Rostov-Don (Russian Federation); Tolochko, B.P. [Institute of Solid State Chemistry and Mechanochemistry, 630128 Novosibirsk (Russian Federation)

    2005-05-01

    A survey of atomic displacement effects in the resonant scattering of synchrotron radiation is presented. It is shown that the dynamical displacements, associated with thermal vibrations, provide the thermal-motion-induced (TMI) 'forbidden' reflections, while static displacements (e.g. induced by impurities) provide the point-defect-induced (PDI) 'forbidden' reflections. Both kinds of reflections occur owing to perturbation of valent electrons wave functions by atomic displacements. The results of numerical calculations of TMI forbidden reflections in Ge and ZnO are compared with experimental data.

  18. Water

    Science.gov (United States)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  1. Interferometric fiber optic displacement sensor

    Science.gov (United States)

    Farah, John (M.I.T. P.O. Box 397301, Cambridge, MA 02139)

    1999-01-01

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically.

  2. Displaced femoral neck fractures in the elderly : treatment with arthroplasties

    OpenAIRE

    Inngul, Christian

    2015-01-01

    Treatment of displaced femoral neck fractures in the elderly with arthroplasties has become standard practice during the last decade and results in good and predictable outcomes regarding hip function and health-related quality of life (HRQoL). There is, however, a lack of evidence concerning certain types of arthroplasties and different subgroups of patients. Patients with severe cognitive dysfunction have a very limited life expectancy after a hip fracture and low functional ...

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

    OpenAIRE

    Sawai, Nobuhiko; Takara, Kaoru; Kobayashi, Kenichiro

    2013-01-01

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

  4. Korean Red Ginseng Water Extract Restores Impaired Endothelial Function by Inhibiting Arginase Activity in Aged Mice

    OpenAIRE

    Choi, Kwanhoon; Yoon, Jeongyeon; Lim, Hyun Kyo; Ryoo, Sungwoo

    2014-01-01

    Cardiovascular disease is the prime cause of morbidity and mortality and the population ages that may contribute to increase in the occurrence of cardiovascular disease. Arginase upregulation is associated with impaired endothelial function in aged vascular system and thus may contribute to cardiovascular disease. According to recent research, Korean Red Ginseng water extract (KRGE) may reduce cardiovascular disease risk by improving vascular system health. The purpose of this study was to ex...

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

    OpenAIRE

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

    2003-01-01

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

  6. Inversion of the volume scattering function and spectral absorption in coastal waters with biogeochemical implications

    OpenAIRE

    ZHANG, X; Huot, Y.; Gray, D. J.; Weidemann, A; W. J. Rhea

    2013-01-01

    In the aquatic environment, particles can be broadly separated into phytoplankton (PHY), non-algal particle (NAP) and dissolved (or very small particle, VSP) fractions. Typically, absorption spectra are inverted to quantify these fractions, but volume scattering functions (VSFs) can also be used. Both absorption spectra and VSFs were used to calculate particle fractions for an experiment in Chesapeake Bay. A complete set of water inherent optical properties was measured using a suite of co...

  7. Dielectric constant of water as a function of separation in a slab geometry: A molecular dynamics study.

    Science.gov (United States)

    Itoh, Hidenosuke; Sakuma, Hiroshi

    2015-05-14

    Water in confining geometries shows various anomalous properties related to its structure and dynamics compared with bulk water. Here, the dielectric constant of water as a function of separation in a graphite slab geometry was studied using molecular dynamics simulations. The dielectric constants of water were calculated from the orientational polarization of water molecules when an external electric field was applied parallel and normal to the slabs. The reduction of the dielectric constant of water compared with bulk water can be explained by investigating the structure and dynamics of water in slab geometries. We found a preferred orientation of water molecules in the layer closest to the graphite surface. The self-diffusion coefficient distribution of water molecules along the direction normal to the slabs was also computed. Highly mobile water molecules in the intermediate region were generated by the weak hydrogen bonding produced by the preferred orientation of water molecules in the layer. We concluded that the dielectric constant of water in the slab geometry is lower than that of bulk water because of the reduction of the polarization of water and the highly mobile water molecules in the intermediate region arising from the preferred orientation of water molecules. PMID:25978901

  8. Dielectric constant of water as a function of separation in a slab geometry: A molecular dynamics study

    Science.gov (United States)

    Itoh, Hidenosuke; Sakuma, Hiroshi

    2015-05-01

    Water in confining geometries shows various anomalous properties related to its structure and dynamics compared with bulk water. Here, the dielectric constant of water as a function of separation in a graphite slab geometry was studied using molecular dynamics simulations. The dielectric constants of water were calculated from the orientational polarization of water molecules when an external electric field was applied parallel and normal to the slabs. The reduction of the dielectric constant of water compared with bulk water can be explained by investigating the structure and dynamics of water in slab geometries. We found a preferred orientation of water molecules in the layer closest to the graphite surface. The self-diffusion coefficient distribution of water molecules along the direction normal to the slabs was also computed. Highly mobile water molecules in the intermediate region were generated by the weak hydrogen bonding produced by the preferred orientation of water molecules in the layer. We concluded that the dielectric constant of water in the slab geometry is lower than that of bulk water because of the reduction of the polarization of water and the highly mobile water molecules in the intermediate region arising from the preferred orientation of water molecules.

  9. Molecular density functional theory for water with liquid-gas coexistence and correct pressure

    Science.gov (United States)

    Jeanmairet, Guillaume; Levesque, Maximilien; Sergiievskyi, Volodymyr; Borgis, Daniel

    2015-04-01

    The solvation of hydrophobic solutes in water is special because liquid and gas are almost at coexistence. In the common hypernetted chain approximation to integral equations, or equivalently in the homogenous reference fluid of molecular density functional theory, coexistence is not taken into account. Hydration structures and energies of nanometer-scale hydrophobic solutes are thus incorrect. In this article, we propose a bridge functional that corrects this thermodynamic inconsistency by introducing a metastable gas phase for the homogeneous solvent. We show how this can be done by a third order expansion of the functional around the bulk liquid density that imposes the right pressure and the correct second order derivatives. Although this theory is not limited to water, we apply it to study hydrophobic solvation in water at room temperature and pressure and compare the results to all-atom simulations. The solvation free energy of small molecular solutes like n-alkanes and hard sphere solutes whose radii range from angstroms to nanometers is now in quantitative agreement with reference all atom simulations. The macroscopic liquid-gas surface tension predicted by the theory is comparable to experiments. This theory gives an alternative to the empirical hard sphere bridge correction used so far by several authors.

  10. Evaluation of Iodine and Water Co-adsorption on Silver-Functionalized Aerogel

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, B. B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, S. H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Walker, J. F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-04-30

    The co-adsorption of iodine and water on silver-functionalized silica aerogel was evaluated using research quantities of the aerogel prepared at Pacific Northwest National Laboratory. A macro thermogravimetric analyzer was used to measure weight changes in a thin bed of the aerogel as air streams containing moisture and/or iodine flowed through the bed. The total gas flow in all tests was adjusted to achieve a velocity of 10 m/min through the bed. Initial heating of the aerogel sample to 150°C in dry air (dew point < -60°C) resulted in weight loss on the order of 1 wt %. Because subsequent phases of the tests indicated that the aerogel did not sorb water, the weight loss was speculated to be caused by volatilization of material that may have been used in the manufacture of the aerogel. Follow-on tests are recommended to ascertain if the aerogel sorbs water at low temperatures, such as 25°C—this would help to determine if a manufacturing reagent is volatilized when raising the sample to iodine sorption temperatures (i.e., 150°C). Alternatively, the off-gas released upon heating could be condensed and analyzed. In tests using humidified air streams with dew points between -60°C and +10°C, the aerogel did not adsorb water at test temperatures of either 75°C or 150°C. Because water alone was not adsorbed, tests were performed to ascertain if iodine sorption varied between cases when nearly no water was present in the gas stream and when water was present. In one experiment, the gas stream consisted of dry air (dew point < -60°C) with an iodine concentration of 50 ppmv. In the other experiment, the gas stream consisted of air with a water dew point of 0°C and an iodine concentration of 50 ppmv. The ultimate weight gain was nearly the same in both experiments and was presumed to be due entirely to adsorption of iodine. However, a reduced rate of iodine uptake is indicated when water vapor is present. The reason for this is unclear. In both cases, purging the sample with dry, iodine-free air resulted in some weight loss (~2 wt %). It is recommended that the gas phase chemistry of the iodine–water system be reviewed to ascertain if iodine species that are less reactive with silver than molecular iodine are present; this could explain the reduced sorption rates when water is present. Further evaluation of the desorption is recommended, especially to determine how raising the temperature would affect desorption.

  11. Preventing re-displacement through genuine reintegration in Burundi

    Directory of Open Access Journals (Sweden)

    Lucy Hovil

    2012-12-01

    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.

  12. The population genetics of sperm displacement

    DEFF Research Database (Denmark)

    Prout, Timothy; Bundgaard, JØrgen

    1977-01-01

    This article reports the results of some sperm displacement experiments, as well as the results of a theoretical study of selection arising from genetic differences in displacing ability. The experimental work involved the use of three genetic marker stocks in double and triple matings. The speed of displacement following the matings was determined by scoring the progeny of each female daily. There were clear differences between strains in their displacing ability. It is shown how new information concerning the displacement process results when three markers are used; however, no new light is shed by these experiments on the mechanism of displacement. The theoretical study of selection resulting from displacement uses a one-locus, two-allele model in which three diploid male genotypes confer different displacing abilities. The results indicate stable equilibria if (1) there is heterosis, and (2) there are certain nontransitive relationships in displacing ability among the different kinds of double matings. Some evolutionary consequences are discussed in which sperm displacement is regarded as a form of sexual selection.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  14. 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

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

    Directory of Open Access Journals (Sweden)

    Kardassis Dimitris

    2009-07-01

    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.

  16. Variable delivery, fixed displacement pump

    Science.gov (United States)

    Sommars, Mark F. (Sparland, IL)

    2001-01-01

    A variable delivery, fixed displacement pump comprises a plurality of pistons reciprocated within corresponding cylinders in a cylinder block. The pistons are reciprocated by rotation of a fixed angle swash plate connected to the pistons. The pistons and cylinders cooperate to define a plurality of fluid compression chambers each have a delivery outlet. A vent port is provided from each fluid compression chamber to vent fluid therefrom during at least a portion of the reciprocal stroke of the piston. Each piston and cylinder combination cooperates to close the associated vent port during another portion of the reciprocal stroke so that fluid is then pumped through the associated delivery outlet. The delivery rate of the pump is varied by adjusting the axial position of the swash plate relative to the cylinder block, which varies the duration of the piston stroke during which the vent port is closed.

  17. Policies for displaced workers: An american perspective

    OpenAIRE

    O Leary, Christopher J.

    2010-01-01

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

  18. Displacement speeds in turbulent premixed flame simulations

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

    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.

  19. Displacing AIDS: therapeutic transitions in Northern Uganda

    OpenAIRE

    Wilhelm-solomon, M. M.; Alexander, Jocelyn; Daley, Patricia

    2014-01-01

    This doctoral project, entitled 'Displacing AIDS: Therapeutic Transitions in Northern Uganda' examines the biosocial transitions engendered by the treatment of HIV, focusing on antiretroviral therapy (ART/ARV) interventions, and the ways these are intertwined with the social transitions of conflict, displacement and return. The research involved an inter-disciplinary qualitative study with internally displaced communities living with HIV in northern Uganda, during 10 months fieldwork between ...

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

    International Nuclear Information System (INIS)

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

  1. Assembly of Acid-Functionalized Single-Walled Carbon Nanotubes at Oil/Water Interfaces

    Science.gov (United States)

    Feng, Tao; Hoagland, David; Russell, Thomas

    2014-03-01

    The segregation of water-soluble acid-functionalized single-walled carbon nanotubes (SWCNTs) at the oil/water interface was induced by dissolving low-molecular-weight amine-terminated polystyrene (PS-NH2) in the oil phase. Salt-bridge interactions between carboxylic acid groups of SWCNTs and amine groups of PS drove assembly of a mixed interfacial film, monitored by pendant drop tensiometry and laser scanning confocal microscopy. The influence of PS end-group functionality, PS and SWCNT concentrations, and degree of SWCNT acid modification on interfacial activity were assessed, and a sharp drop in interfacial tension was observed above a critical SWCNT concentration. Interfacial tensions were low enough to support stable oil/water emulsions. Further experiments, including potentiometric titrations and replacement of SWCNTs by other carboxyl-containing species, demonstrated that the interfacial tension drop reflects the loss of SWCNT charge as pH falls near/below the intrinsic carboxyl dissociation constant; species lacking multivalent carboxylic acid groups are inactive. The interfacial assemblies of SWCNTs appear neither ordered nor oriented. Research Advisor.

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

    Science.gov (United States)

    Cluis, D A

    1983-06-01

    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

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

    Science.gov (United States)

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

    2013-12-01

    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.

  4. 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)

  5. Displacement of Monolithic Rubble-Mound Breakwater Crown-Walls

    DEFF Research Database (Denmark)

    NØrgaard, JØrgen Harck; Andersen, Lars Vabbersgaard

    2012-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-12-15

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

  7. Cation exchange displacement batch chromatography of proteins guided by screening of protein purification parameters.

    Science.gov (United States)

    Kotasi?ska, Marta; Richter, Verena; Thiemann, Joachim; Schlüter, Hartmut

    2012-11-01

    Displacement chromatography has been shown to be an effective alternative for protein purification. We investigated in this study sample displacement chromatography, which does not require a displacer molecule. Furthermore, we performed a screening for determination of parameters for an optimal sample displacement chromatography. We screened the affinities of cytochrome C, lysozyme, myoglobin, and ribonuclease A toward a cation exchange material as a function of different pH values and to presence of different concentrations of sodium chloride in the sample application buffer. Sample displacement chromatography in batch chromatography mode for the separation of the protein mixture was studied with a sample application buffer with a pH of 5 and 7. As predicted by the screening experiments, sample displacement chromatography was most effective at pH 7 since this pH guaranteed the largest differences of the affinities of the four proteins toward the stationary phase. In summary, we describe here sample displacement chromatography in the batch chromatography mode for the separation of proteins, which is a simple and fast alternative to conventional displacement chromatography. Systematic screening of chromatographic parameters prior to sample displacement chromatography promises a successful separation of a target protein. PMID:22707445

  8. Layered double hydroxide functionalized textile for effective oil/water separation and selective oil adsorption.

    Science.gov (United States)

    Liu, Xiaojuan; Ge, Lei; Li, Wei; Wang, Xiuzhong; Li, Feng

    2015-01-14

    The removal of oil and organic pollutants from water is highly desired due to frequent oil spill accidents, as well as the increase of industrial oily wastewater. Here, superhydrophobic and superoleophilic textile has been successfully prepared for the application of effective oil/water separation and selective oil adsorption. This textile was fabricated by functionalizing the commercial textile with layered double hydroxide (LDH) microcrystals and low surface energy molecules. The LDH microcrystals were immobilized on the microfibers of the textile through an in situ growth method, and they formed a nestlike microstructure. The combination of the hierarchical structure and the low surface energy molecules made the textile superhydrophobic and superoleophilic. Further experiments demonstrated that the as-prepared textile not only can be applied as effective membrane materials for the separation of oil and water mixtures with high separation efficiency (>97%), but also can be used as a bag for the selective oil adsorption from water. Thus, such superhydrophobic and superoleophilic textile is a very promising material for the application of oil spill cleanup and industrial oily wastewater treatment. PMID:25490110

  9. 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

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

    International Nuclear Information System (INIS)

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

  11. Steel corrosion in concrete: Determinist modeling of cathodic reaction as a function of water saturation degree

    International Nuclear Information System (INIS)

    The prediction of the long-term behavior of reinforced concrete structures involved in the nuclear waste storage requires the assessment and the modeling of the corrosion processes of steel reinforcement. This paper deals with the modeling of the cathodic reaction that is one of the main mechanisms of steel rebar corrosion. This model takes into account oxygen reduction and oxygen diffusion through a diffusion barrier (iron oxide and/or carbonated concrete) as a function of water saturation degree. It is demonstrated that corrosion rate of reinforcement embedded in concrete with water saturation degree as low as 0.9 could be under oxygen diffusion control. Thus, transport properties of concrete (aqueous and gaseous phase, dissolved species) are key parameters that must be taken into account to model electrochemical processes on the reinforcement

  12. Bio-functionalized water-soluble ZnS quantum dots using carboxymethylchitosan

    Science.gov (United States)

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

    2015-03-01

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

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

    International Nuclear Information System (INIS)

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

  14. Assessment of carbon atom displacement rate in the irradiation facility of the IRT-2000 reactor

    International Nuclear Information System (INIS)

    The article showed displacement number of atom, the damage function, according to the energy of the carbon atom on the basis of the analysis of the displacement processes of crystal atom formed at the time when the high speed carbon atom penetrated through the graphite crystal. Using the neutron spectra and damage function in the irradiation facility of the IRT-2000 reactor which was calculated by Monte Carlo method, we studied the displaced rate of the carbon atom in the graphite crystal per unit of nickel fission flux. The result is as follows. DNi=1063x10-24, atom/atomxsecx?Ni. (author)

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

    Science.gov (United States)

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

    2012-07-01

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

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

    Directory of Open Access Journals (Sweden)

    J. Moeys

    2012-02-01

    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.

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

    Directory of Open Access Journals (Sweden)

    J. Moeys

    2012-07-01

    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.

  18. Measurement of source transfer function and space dependence using pulsed neutron source on beryllium-light water lattice

    International Nuclear Information System (INIS)

    This paper describes an on-line pulsed neutron source experiment on beryl lium-light water lattice. Pulsed neutron source transfer functions are given. Space-dependent neutron decay constant ? has been found and results are discussed

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

    Scientific Electronic Library Online (English)

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

    2004-12-01

    Full Text Available 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.

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

    International Nuclear Information System (INIS)

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

  1. 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.)

  2. Video Games, Adolescents, and the Displacement Effect

    Science.gov (United States)

    Fisher, Carla Christine

    2012-01-01

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

  3. Displacement of atoms and radiation induced defects

    International Nuclear Information System (INIS)

    Physical radiation effects of fast neutrons on DT fusion reactor materials are reviewed. First fundamental processes of displacement and the cascade damage of materials induced by high-energy particles are explained. Next the annihilation process and bias effect of radiation-induced defects are discussed. Finally, the definition of dpa, a measure of displacement is given. (J.P.N.)

  4. Modeling the Impact of Deformation on Unstable Miscible Displacements in Porous Media

    Science.gov (United States)

    Santillán, D.; Cueto-Felgueroso, L.

    2014-12-01

    Coupled flow and geomechanics is a critical research challenge in engineering and the geosciences. The simultaneous flow of two or more fluids with different densities or viscosities through deformable media is ubiquitous in environmental, industrial, and biological processes, including the removal of non-aqueous phase liquids from underground water bodies, the geological storage of CO2, and current challenges in energy technologies, such as enhanced geothermal systems, unconventional hydrocarbon resources or enhanced oil recovery techniques. Using numerical simulation, we study the interplay between viscous-driven flow instabilities (viscous fingering) and rock mechanics, and elucidate the structure of the displacement patterns as a function of viscosity contrast, injection rate and rock mechanical properties. Finally, we discuss the role of medium deformation on transport and mixing processes in porous media.

  5. Displaced proximal humeral fractures: an Indian experience with locking plates

    OpenAIRE

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

    2010-01-01

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

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

    Scientific Electronic Library Online (English)

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

    2014-12-01

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

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

    Scientific Electronic Library Online (English)

    Wely Brasil, Floriano; Marco Antonio Chaer, Nascimento.

    2004-03-01

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

  8. Functional Traits and Water Transport Strategies in Lowland Tropical Rainforest Trees

    Science.gov (United States)

    Apgaua, Deborah M. G.; Ishida, Françoise Y.; Tng, David Y. P.; Laidlaw, Melinda J.; Santos, Rubens M.; Rumman, Rizwana; Eamus, Derek; Holtum, Joseph A. M.; Laurance, Susan G. W.

    2015-01-01

    Understanding how tropical rainforest trees may respond to the precipitation extremes predicted in future climate change scenarios is paramount for their conservation and management. Tree species clearly differ in drought susceptibility, suggesting that variable water transport strategies exist. Using a multi-disciplinary approach, we examined the hydraulic variability in trees in a lowland tropical rainforest in north-eastern Australia. We studied eight tree species representing broad plant functional groups (one palm and seven eudicot mature-phase, and early-successional trees). We characterised the species’ hydraulic system through maximum rates of volumetric sap flow and velocities using the heat ratio method, and measured rates of tree growth and several stem, vessel, and leaf traits. Sap flow measures exhibited limited variability across species, although early-successional species and palms had high mean sap velocities relative to most mature-phase species. Stem, vessel, and leaf traits were poor predictors of sap flow measures. However, these traits exhibited different associations in multivariate analysis, revealing gradients in some traits across species and alternative hydraulic strategies in others. Trait differences across and within tree functional groups reflect variation in water transport and drought resistance strategies. These varying strategies will help in our understanding of changing species distributions under predicted drought scenarios. PMID:26087009

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

    DEFF Research Database (Denmark)

    Takeyama, Yuko; Ohsawa, Teruo

    2013-01-01

    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.

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

    Science.gov (United States)

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

    2010-09-01

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

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

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal

    1995-01-01

    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.

  12. Density Functional Theory simulations of water: phase-diagram and electrical conductivity

    Science.gov (United States)

    Mattsson, Thomas R.; Desjarlais, Michael P.

    2006-10-01

    Knowledge of the properties of water is essential for correctly describing the physics of giant planets as well as shock waves in water. 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/ superionic/ electronic liquid). There is a rapid transition to ionic conduction at 2000 K and 2 g/cm^3 while electronic conduction dominates at temperatures at and above 6000 K. We predict that the fluid bordering the superionic phase is conducting above 4000 K and 100 GPa [1]. Earlier work instead has the superionic phase bordering an insulating fluid, with a transition to metallic fluid not until 7000 K and 250 GPa. The LDRD office at SNL supported this work. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. [1] T.R. Mattsson and M.P. Desjarlais, Phys. Rev. Lett. 97, 017801 (2006).

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

    CERN Document Server

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

    2011-01-01

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Desjarlais, Michael Paul; Mattsson, Thomas Kjell Rene

    2006-03-01

    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.

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

    Science.gov (United States)

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

    2014-03-01

    The 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.

  16. 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.

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

    International Nuclear Information System (INIS)

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

  18. Evaluation of water quality functions of conventional and advanced soil-based onsite wastewater treatment systems.

    Science.gov (United States)

    Cooper, Jennifer A; Loomis, George W; Kalen, David V; Amador, Jose A

    2015-05-01

    Shallow narrow drainfields are assumed to provide better wastewater renovation than conventional drainfields and are used for protection of surface and ground water. To test this assumption, we evaluated the water quality functions of two advanced onsite wastewater treatment system (OWTS) drainfields-shallow narrow (SND) and Geomat (GEO)-and a conventional pipe and stone (P&S) drainfield over 12 mo using replicated ( = 3) intact soil mesocosms. The SND and GEO mesocosms received effluent from a single-pass sand filter, whereas the P&S received septic tank effluent. Between 97.1 and 100% of 5-d biochemical oxygen demand (BOD), fecal coliform bacteria, and total phosphorus (P) were removed in all drainfield types. Total nitrogen (N) removal averaged 12.0% for P&S, 4.8% for SND, and 5.4% for GEO. A mass balance analysis accounted for 95.1% (SND), 94.1% (GEO), and 87.6% (P&S) of N inputs. When the whole treatment train (excluding the septic tank) is considered, advanced systems, including sand filter pretreatment and SND or GEO soil-based treatment, removed 99.8 to 99.9% of BOD, 100% of fecal coliform bacteria and P, and 26.0 to 27.0% of N. In contrast, the conventional system removed 99.4% of BOD and 100% of fecal coliform bacteria and P but only 12.0% of N. All drainfield types performed similarly for most water quality functions despite differences in placement within the soil profile. However, inclusion of the pretreatment step in advanced system treatment trains results in better N removal than in conventional treatment systems despite higher drainfield N removal rates in the latter. PMID:26024275

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

    DEFF Research Database (Denmark)

    Bolam, Stefan; Kenny, Andrew

    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

  20. Displacement cross section and DPA calculations using NMTC/JAERI

    International Nuclear Information System (INIS)

    A new function calculating displacement cross sections using the Lindhard-Robinson model is implemented in the nucleon-meson transport code NMTC/JAERI. The nucleon-nucleus cross sections in the energy region above 950 MeV and the angular distribution data of elastic scattering are also modified to evaluate the displacement cross sections as accurate as possible. The displacement cross sections of Cr, Fe Ni, and type 316 stainless steel are calculated with the updated version of NMTC/JAERI. It is confirmed that the calculated displacement cross sections caused by the elastic scattering connect smoothly with the value of the JENDL PKA File at 20 MeV. With these calculation values, the displacement per atoms (DPA) in the beam window and target vessel of a mercury target are estimated in a framework of the neutronics design study of the spallation target bombarded with 1.5 GeV protons with a power of 5 MW. The following three beam conditions are selected in this calculation; (a) uniform distribution with average current density of 48 ?A/cm2, (b) parabolic distribution with average current density of 48 ?A/cm2, and (c) that with average current density of 24 ?A/cm2. The DPAs are estimated as (a) 68, (b) 114, and (c) 70 DPA/yr at the beam windows, and (a) 41, (b) 52, and (c) 37 DPA/yr at the target vessel for the three cases, respectively. It is found that the DPAs obtained in this study are almost the same as the results of other design studies for spallation neutron source facilities. (author)

  1. Spatial characteristics of displacement cascades in metals

    International Nuclear Information System (INIS)

    The binary-collision simulation code marlowe has been applied to study spatial characteristics of displacement cascades in fcc metals, particularly Cu. Mean densities of vacancies and interstitials and expressed in terms of radii of gyration of the defect configurations, have been determined as functions of cascade energy. In Cu, decreases from approx.6 x 10-2 to approx.4 x 10-4 for energies between 1 and 150 keV, whereas approx.3 x 10-3 is roughly constant at energies below 20 keV and approaches asymptotically at higher energies. Although / decreases with energy, the mean vacancy-interstitial separation R/sub i/v is relatively constant. This result supports the classical picture of depleted zones in which increasing numbers of vacancy clusters surrounded by clouds of interstitials are formed as the energy is increased. Perspective plots of the defect configurations in individual cascades presented here also support this picture. Channeling is concluded to have a small effect on , but strongly influences the skewness of damage depth profiles. Results are presented for the cascade contraction factor delta. The tendency to form defect clusters and subcascades is discussed

  2. Factors shaping bacterial phylogenetic and functional diversity in coastal waters of the NW Mediterranean Sea

    Science.gov (United States)

    Boras, Julia A.; Vaqué, Dolors; Maynou, Francesc; Sà, Elisabet L.; Weinbauer, Markus G.; Sala, Maria Montserrat

    2015-03-01

    To evaluate the main factors shaping bacterioplankton phylogenetic and functional diversity in marine coastal waters, we carried out a two-year study based on a monthly sampling in Blanes Bay (NW Mediterranean). We expected the key factors driving bacterial diversity to be (1) temperature and nutrient concentration, together with chlorophyll a concentration as an indicator of phytoplankton biomass and, hence, a carbon source for bacteria (here called bottom-up factors), and (2) top-down pressure (virus- and protist-mediated mortality of bacteria). Phylogenetic diversity was analyzed by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA. Functional diversity was assessed by using monomeric carbon sources in Biolog EcoPlates and by determining the activity of six extracellular enzymes. Our results indicate that the bacterial phylogenetic and functional diversity in this coastal system is shaped mainly by bottom-up factors. A dendrogram analysis of the DGGE banding patterns revealed three main sample clusters. Two clusters differed significantly in temperature, nitrate and chlorophyll a concentration, and the third was characterized by the highest losses of bacterial production due to viral lysis detected over the whole study period. Protistan grazing had no effect on bacterial functional diversity, since there were no correlations between protist-mediated mortality (PMM) and extracellular enzyme activities, and utilization of only two out of the 31 carbon sources (N-acetyl-D-glucosamine and ?-cyclodextrin) was correlated with PMM. In contrast, virus-mediated mortality correlated with changes in the percentage of use of four carbon sources, and also with specific leu-aminopeptidase and ?-glucosidase activity. This suggests that viral lysate provides a pool of labile carbon sources, presumably including amino acids and glucose, which may inhibit proteolytic and glucosidic activity. Our results indicate that bottom-up factors play a more important role than top-down factors (i.e. viral lysis and protistan grazing) in shaping bacterial community structure and activity. Furthermore, they suggest that viruses play a more important role than protists in modifying community structure and functional diversity of bacteria in oligotrophic marine coastal waters.

  3. Gastric emptying of water in children with severe functional fecal retention

    Directory of Open Access Journals (Sweden)

    V.P.I. Fernandes

    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.

  4. Gastric emptying of water in children with severe functional fecal retention

    Scientific Electronic Library Online (English)

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

    2013-03-15

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

  5. Sensitivity of Displaced-Beam Scintillometer Measurements of Area-Average Heat Fluxes to Uncertainties in Topographic Heights

    OpenAIRE

    Gruber, Matthew; Fochesatto, Javier; Hartogensis, Oscar

    2014-01-01

    Displaced-beam scintillometer measurements of the turbulence inner-scale length $l_o$ and refractive index structure function $C_n^2$ resolve area-average turbulent fluxes of heat and momentum through the Monin-Obukhov similarity equations. Sensitivity studies have been produced for the use of displaced-beam scintillometers over flat terrain. Many real field sites feature variable topography. We develop here an analysis of the sensitivity of displaced-beam scintillometer der...

  6. Density Functional Theory in High Energy Density Physics: phase-diagram and electrical conductivity of water

    Science.gov (United States)

    Mattsson, Thomas R.

    2007-06-01

    Atomistic simulations employing Density Functional Theory (DFT) have recently emerged as a powerful way of increasing our understanding of materials and processes in high energy density physics. Knowledge of the properties of water (equation of state, electrical conductivity, diffusion, low-energy opacity) is essential for correctly describing the physics of giant planets as well as shock waves in water. Although a qualitative picture of water electrical conductivity has emerged, the necessary quantitative information is scarce over a wide range of temperature and density. Since experiments can only access certain areas of phase space, and often require modeling as a part of the analysis, Quantum Molecular Dynamics simulations play a vital role. Using finite-temperature density functional theory (FT-DFT), we have investigated the structure and electronic conductivity of water across three phase transitions (molecular liquid/ ionic liquid/ superionic/ electronic liquid). The ionic contribution to the conduction is calculated from proton diffusion and the electronic contribution is calculated using the Kubo-Greenwood formula. The calculations are performed with VASP, a plane-wave pseudo-potential code. There is a rapid transition to ionic conduction at 2000 K and 2 g/cm^3, whereas electronic conduction dominates at temperatures at and above 6000 K&[tilde;1]. Contrary to earlier results using the Car-Parrinello method&[tilde;2], we predict that the fluid bordering the superionic phase is conducting above 4000 K and 100 GPa. Our comprehensive use of FT-DFT explains the new findings. The calculated conductivity is compared to experimental data. I gratefully acknowledge Mike Desjarlais, my collaborator in this effort. The LDRD office at Sandia supported this work. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. [1] T.R. Mattsson and M.P. Desjarlais, Phys. Rev. Lett. 97, 017801 (2006). [2] C. Cavazzoni, et. al. Science 283, 44 (1999).

  7. 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)

  8. Graphene on ferromagnetic surfaces and its functionalization with water and ammonia

    Directory of Open Access Journals (Sweden)

    Voloshina Elena

    2011-01-01

    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.

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  11. Water Extract of Acer tegmentosum Reduces Bone Destruction by Inhibiting Osteoclast Differentiation and Function

    Directory of Open Access Journals (Sweden)

    Hyunil Ha

    2014-04-01

    Full Text Available The stem of Acer tegmentosum has been widely used in Korea for the treatment of hepatic disorders. In this study, we investigated the bone protective effect of water extract of the stem of Acer tegmentosum (WEAT. We found that WEAT inhibits osteoclast differentiation induced by receptor activator of nuclear factor-?B ligand (RANKL, an essential cytokine for osteoclast differentiation. In osteoclast precursor cells, WEAT inhibited RANKL-induced activation of JNK, NF-?B, and cAMP response element-binding protein, leading to suppression of the induction of c-Fos and nuclear factor of activated T cells cytoplasmic 1, key transcription factors for osteoclast differentiation. In addition, WEAT inhibited bone resorbing activity of mature osteoclasts. Furthermore, the oral administration of WEAT reduced RANKL-induced bone resorption and trabecular bone loss in mice. Taken together, our study demonstrates that WEAT possesses a protective effect on bone destruction by inhibiting osteoclast differentiation and function.

  12. Making work safe for displaced women

    Directory of Open Access Journals (Sweden)

    Dale Buscher

    2012-12-01

    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.

  13. Displacement field measurement in the nanometer range

    Science.gov (United States)

    Surrel, Yves; Fournier, Nicolas

    1996-09-01

    The grid method is a classical tool for displacement measurement, which provides field data. This method has benefited very much from the phase-shifting technique in recent years. Two examples of applications of this method in the nanometer range are presented. The first one concerns the materials science: it is shown that microgrids observed by SEM can provide displacement field data with an accuracy of a few nanometers. The second one concerns the measurement of a rigid-body displacement. In this case, displacement data can be averaged over the whole field, drastically increasing the sensitivity. It is shown that a sensitivity of 7 nm can be achieved by using a coarse grid with 8 lines per mm. This sensitivity corresponds to 1/18000 of the grid pitch.

  14. Epitaxial growth by monolayer restricted galvanic displacement

    Directory of Open Access Journals (Sweden)

    Vasili? Rastko

    2012-01-01

    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.

  15. Assisting the return of displaced Dinka Bor

    Directory of Open Access Journals (Sweden)

    Paul Murphy

    2005-11-01

    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.

  16. 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

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

    Science.gov (United States)

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

    2014-11-01

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

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

    DEFF Research Database (Denmark)

    Shi, X. R.; Wang, Shengguang

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2014-09-01

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

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

    Scientific Electronic Library Online (English)

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

    1365-13-01

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

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

    Directory of Open Access Journals (Sweden)

    Kang Zhou

    2012-12-01

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

  3. The intergenerational effects of worker displacement

    OpenAIRE

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

    2005-01-01

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

  4. PDT - PARTICLE DISPLACEMENT TRACKING SOFTWARE

    Science.gov (United States)

    Wernet, M. P.

    1994-01-01

    Particle Imaging Velocimetry (PIV) is a quantitative velocity measurement technique for measuring instantaneous planar cross sections of a flow field. The technique offers very high precision (1%) directionally resolved velocity vector estimates, but its use has been limited by high equipment costs and complexity of operation. Particle Displacement Tracking (PDT) is an all-electronic PIV data acquisition and reduction procedure which is simple, fast, and easily implemented. The procedure uses a low power, continuous wave laser and a Charged Coupled Device (CCD) camera to electronically record the particle images. A frame grabber board in a PC is used for data acquisition and reduction processing. PDT eliminates the need for photographic processing, system costs are moderately low, and reduced data are available within seconds of acquisition. The technique results in velocity estimate accuracies on the order of 5%. The software is fully menu-driven from the acquisition to the reduction and analysis of the data. Options are available to acquire a single image or 5- or 25-field series of images separated in time by multiples of 1/60 second. The user may process each image, specifying its boundaries to remove unwanted glare from the periphery and adjusting its background level to clearly resolve the particle images. Data reduction routines determine the particle image centroids and create time history files. PDT then identifies the velocity vectors which describe the particle movement in the flow field. Graphical data analysis routines are included which allow the user to graph the time history files and display the velocity vector maps, interpolated velocity vector grids, iso-velocity vector contours, and flow streamlines. The PDT data processing software is written in FORTRAN 77 and the data acquisition routine is written in C-Language for 80386-based IBM PC compatibles running MS-DOS v3.0 or higher. Machine requirements include 4 MB RAM (3 MB Extended), a single or multiple frequency RGB monitor (EGA or better), a math co-processor, and a pointing device. The printers supported by the graphical analysis routines are the HP Laserjet+, Series II, and Series III with at least 1.5 MB memory. The data acquisition routines require the EPIX 4-MEG video board and optional 12.5MHz oscillator, and associated EPIX software. Data can be acquired from any CCD or RS-170 compatible video camera with pixel resolution of 600hX400v or better. PDT is distributed on one 5.25 inch 360K MS-DOS format diskette. Due to the use of required proprietary software, executable code is not provided on the distribution media. Compiling the source code requires the Microsoft C v5.1 compiler, Microsoft QuickC v2.0, the Microsoft Mouse Library, EPIX Image Processing Libraries, the Microway NDP-Fortran-386 v2.1 compiler, and the Media Cybernetics HALO Professional Graphics Kernal System. Due to the complexities of the machine requirements, COSMIC strongly recommends the purchase and review of the documentation prior to the purchase of the program. The source code, and sample input and output files are provided in PKZIP format; the PKUNZIP utility is included. PDT was developed in 1990. All trade names used are the property of their respective corporate owners.

  5. Allosteric indicator displacement enzyme assay for a cyanogenic glycoside.

    Science.gov (United States)

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

    2013-10-18

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

  6. Packing defects functionalize soluble proteins.

    Science.gov (United States)

    Fernández, Ariel

    2015-04-13

    This work explores the participation of protein packing defects, the so-called dehydrons, in biochemical events. We delineate the enabling role of dehydrons as activators of nucleophilic groups. This activation results from the induction of chemical basicity in interfacial water molecules, promoting deprotonation of adjacent nucleophiles. Through multiple steering molecular dynamics with pulling along the proton-displacement coordinate, we show that nucleophilic groups are functionally enabled by nearby dehydrons that promote proton transference. The computations are validated against experimentally determined pKa decreases at functional sites and biochemical probes of deregulated catalytic activity arising from dehydron-generating mutations. PMID:25771861

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

    DEFF Research Database (Denmark)

    Kelkkanen, Kari André; Lundqvist, Bengt

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2013-08-21

    Indium tin oxide (ITO) surfaces of triple junction photovoltaic cells were functionalized with oxygen evolving catalysts (OECs) based on amorphous hydrous earth-abundant metal oxides (metal = Fe, Ni, Co), obtained by straightforward Successive Ionic Layer Adsorption and Reaction (SILAR) in an aqueous environment. Functionalization with Fe(iii) oxides gave the best results, leading to photoanodes capable of efficiently splitting water, with photocurrent densities up to 6 ± 1 mA cm(-2) at 0 V vs. the reversible hydrogen electrode (RHE) under AM 1.5 G simulated sunlight illumination. The resulting Solar To Hydrogen (STH) conversion efficiencies, measured in two electrodes configuration, were in the range 3.7-5%, depending on the counter electrode that was employed. Investigations on the stability showed that these photoanodes were able to sustain 120 minutes of continuous illumination with a < 10% photocurrent loss at 0 V vs. RHE. Pristine photoanodic response of the cells could be fully restored by an additional SILAR cycle, evidencing that the observed loss is due to the detachment of the more weakly surface bound catalyst. PMID:23820552

  10. Korean red ginseng water extract restores impaired endothelial function by inhibiting arginase activity in aged mice.

    Science.gov (United States)

    Choi, Kwanhoon; Yoon, Jeongyeon; Lim, Hyun Kyo; Ryoo, Sungwoo

    2014-04-01

    Cardiovascular disease is the prime cause of morbidity and mortality and the population ages that may contribute to increase in the occurrence of cardiovascular disease. Arginase upregulation is associated with impaired endothelial function in aged vascular system and thus may contribute to cardiovascular disease. According to recent research, Korean Red Ginseng water extract (KRGE) may reduce cardiovascular disease risk by improving vascular system health. The purpose of this study was to examine mechanisms contributing to age-related vascular endothelial dysfunction and to determine whether KRGE improves these functions in aged mice. Young (10±3 weeks) and aged (55±5 weeks) male mice (C57BL/6J) were orally administered 0, 10, or 20 mg/mouse/day of KRGE for 4 weeks. Animals were sacrificed and the aortas were removed. Endothelial arginase activity, nitric oxide (NO) generation and reactive oxygen species (ROS) production, endothelial nitric oxide synthase (eNOS) coupling, vascular tension, and plasma peroxynitrite production were measured. KRGE attenuated arginase activity, restored nitric oxide (NO) generation, reduced ROS production, and enhanced eNOS coupling in aged mice. KRGE also improved vascular tension in aged vessels, as indicated by increased acetylcholine-induced vasorelaxation and improved phenylephrine-stimulated vasoconstriction. Furthermore, KRGE prevented plasma peroxynitrite formation in aged mice, indicating reduced lipid peroxidation. These results suggest KRGE exerts vasoprotective effects by inhibiting arginase activity and augmenting NO signaling and may be a useful treatment for age-dependent vascular diseases. PMID:24757370

  11. Phase control of a perovskite transition-metal oxide through oxygen displacement at the heterointerface.

    Science.gov (United States)

    Kan, Daisuke; Aso, Ryotaro; Kurata, Hiroki; Shimakawa, Yuichi

    2015-06-21

    Controlling structural distortions that are closely related to functional properties in transition-metal oxides is a key not only to exploring novel phenomena but also to developing novel oxide-based electronic devices. In this review article, we overview investigations revealing that oxygen displacement at the heterointerface is a key parameter characterizing structure-property relationships of heterostructures. We further demonstrate that the interface engineering of the oxygen displacement is useful to control structural and electronic properties of strained oxides. PMID:25848647

  12. Geostationary Satellite Observation of Precipitable Water Vapor Using an Empirical Orthogonal Function (EOF based Reconstruction Technique over Eastern China

    Directory of Open Access Journals (Sweden)

    Man Sing Wong

    2015-05-01

    Full Text Available Water vapor, as one of the most important greenhouse gases, is crucial for both climate and atmospheric studies. Considering the high spatial and temporal variations of water vapor, a timely and accurate retrieval of precipitable water vapor (PWV is urgently needed, but has long been constrained by data availability. Our study derived the vertically integrated precipitable water vapor over eastern China using Multi-functional Transport Satellite (MTSAT data, which is in geostationary orbit with high temporal resolution. The missing pixels caused by cloud contamination were reconstructed using an Empirical Orthogonal Function (EOF decomposition method over both spatial and temporal dimensions. GPS meteorology data were used to validate the retrieval and the reconstructed results. The diurnal variation of PWV over eastern China was analyzed using harmonic analysis, which indicates that the reconstructed PWV data can depict the diurnal cycle of PWV caused by evapotranspiration and local thermal circulation.

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

    Science.gov (United States)

    Asaduzzaman, Abu; Muralidharan, Krishna; Ganguly, Jibamitra

    2015-04-01

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

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

    Scientific Electronic Library Online (English)

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

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

  15. Stimulatory Effects of Balanced Deep Sea Water on Mitochondrial Biogenesis and Function

    Science.gov (United States)

    Ha, Byung Geun; Park, Jung-Eun; Cho, Hyun-Jung; Shon, Yun Hee

    2015-01-01

    The worldwide prevalence of metabolic diseases, including obesity and diabetes, is increasing. Mitochondrial dysfunction is recognized as a core feature of these diseases. Emerging evidence also suggests that defects in mitochondrial biogenesis, number, morphology, fusion, and fission, contribute to the development and progression of metabolic diseases. Our previous studies revealed that balanced deep-sea water (BDSW) has potential as a treatment for diabetes and obesity. In this study, we aimed to investigate the mechanism by which BDSW regulates diabetes and obesity by studying its effects on mitochondrial metabolism. To determine whether BDSW regulates mitochondrial biogenesis and function, we investigated its effects on mitochondrial DNA (mtDNA) content, mitochondrial enzyme activity, and the expression of transcription factors and mitochondria specific genes, as well as on the phosphorylation of signaling molecules associated with mitochondria biogenesis and its function in C2C12 myotubes. BDSW increased mitochondrial biogenesis in a time and dose-dependent manner. Quantitative real-time PCR revealed that BDSW enhances gene expression of PGC-1?, NRF1, and TFAM for mitochondrial transcription; MFN1/2 and DRP1 for mitochondrial fusion; OPA1 for mitochondrial fission; TOMM40 and TIMM44 for mitochondrial protein import; CPT-1? and MCAD for fatty acid oxidation; CYTC for oxidative phosphorylation. Upregulation of these genes was validated by increased mitochondria staining, CS activity, CytC oxidase activity, NAD+ to NADH ratio, and the phosphorylation of signaling molecules such as AMPK and SIRT1. Moreover, drinking BDSW remarkably improved mtDNA content in the muscles of HFD-induced obese mice. Taken together, these results suggest that the stimulatory effect of BDSW on mitochondrial biogenesis and function may provide further insights into the regulatory mechanism of BDSW-induced anti-diabetic and anti-obesity action. PMID:26068191

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

    International Nuclear Information System (INIS)

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

  17. Study of degenerate parabolic system modeling the hydrogen displacement in a nuclear waste repository

    OpenAIRE

    Caro, Florian; Saad, Bilal; Saad, Mazen

    2012-01-01

    Our goal is the mathematical analysis of a two phase (liquid and gas) two components (water and hydrogen) system modeling the hydrogen displacement in a storage site for radioactive waste. We suppose that the water is only in the liquid phase and is incompressible. The hydrogen in the gas phase is supposed compressible and could be dissolved into the water with the Henry's law. The flow is described by the conservation of the mass of each components. The model is treated wit...

  18. A mathematical model of the shore level displacement in Fennoscandia

    International Nuclear Information System (INIS)

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

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

    DEFF Research Database (Denmark)

    Krag, Aleksander; MØller, SØren

    2010-01-01

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

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

    International Nuclear Information System (INIS)

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

  1. Modelling of the Vajont rockslide displacements by delayed plasticity of interacting sliding blocks

    Science.gov (United States)

    Castellanza, riccardo; Hedge, Amarnath; Crosta, Giovanni; di Prisco, Claudio; Frigerio, Gabriele

    2015-04-01

    In order to model complex sliding masses subject to continuous slow movements related to water table fluctuations it is convenient to: i) model the time-dependent mechanical behaviour of the materials by means of a viscous-plastic constitutive law; ii) assume the water table fluctuation as the main input to induce displacement acceleration; iii) consider, the 3D constrains by maintaining a level of simplicity such to allow the implementation into EWS (Early Warning System) for risk management. In this work a 1D pseudo-dynamic visco-plastic model (Secondi et al. 2011), based on Perzyna's delayed plasticity theory is applied. The sliding mass is considered as a rigid block subject to its self weight, inertial forces and seepage forces varying with time. All non-linearities are lumped in a thin layer positioned between the rigid block and the stable bedrock. The mechanical response of this interface is assumed to be visco-plastic. The viscous nucleus is assumed to be of the exponential type, so that irreversible strains develop for both positive and negative values of the yield function; the sliding mass is discretized in blocks to cope with complex rockslide geometries; the friction angle is assumed to reduce with strain rate assuming a sort of strain - rate law (Dietrich-Ruina law). To validate the improvements introduced in this paper the simulation of the displacements of the Vajont rockslide from 1960 to the failure, occurred on October the 9th 1963, is perfomed. It will be shown that, in its modified version, the model satisfactorily fits the Vajont pre-collapse displacements triggered by the fluctuation of the Vajont lake level and the associated groundwater level. The model is able to follow the critical acceleration of the motion with a minimal change in friction properties.The discretization in interacting sliding blocks confirms its suitability to model the complex 3D rockslide behaviour. We are currently implementing a multi-block model capable to include the mutual influence of multiple blocks, characterized by different geometry and groundwater levels, shear zone properties and type of interconnection. Secondi M., Crosta G., Di Prisco C., Frigerio G., Frattini P., Agliardi F. (2011) "Landslide motion forecasting by a dynamic visco-plastic model", Proc. The Second World Landslide Forum, L09 - Advances in slope modelling, Rome, 3-9 October 2011, paper WLF2-2011-0571

  2. Inefficiency of upward displacement operating theatre ventilation.

    Science.gov (United States)

    Friberg, B; Friberg, S; Burman, L G; Lundholm, R; Ostensson, R

    1996-08-01

    A new thermally based ventilation system ('Floormaster') with inlet of cool clean air at floor level, and evacuation at the ceiling of the air warmed by activity in the room (upward displacement ventilation, 17 air changes/h) was compared with a standard positive pressure (plenum) ventilation system with air supply through an inclined perforated screen along one wall at the ceiling and evacuation at floor level (conventional turbulent or mixing system, 16 air changes/h). The study was made during rigidly standardized sham operations (N = 20) performed in the same operating room by a six-member team wearing non-woven disposable or cotton clothing. In general the upward displacement system removed dust particles too small to carry bacteria (0.16-<0.3 microm, 0.001displacement system also yielded two to threefold higher air and surface bacterial counts in areas important for surgical asepsis (wound area, instrument table) especially with regard to bacterial sedimentation (0.001displacement system was insufficient elimination of the larger bacteria-carrying particles. The type of clothing worn by the members of the team did not influence the overall results. We conclude that an upward displacement system will lead to increased counts of airborne and sedimenting bacteria and thus increase the risk of postoperative infection in comparison with conventional operating room ventilation systems. PMID:8999051

  3. Hydraulic differences along the water transport system of South American Nothofagus species: do leaves protect the stem functionality?

    Science.gov (United States)

    Bucci, Sandra J; Scholz, Fabian G; Campanello, Paula I; Montti, Lia; Jimenez-Castillo, Mylthon; Rockwell, Fulton A; Manna, Ludmila La; Guerra, Pedro; Bernal, Pablo Lopez; Troncoso, Oscar; Enricci, Juan; Holbrook, Michele N; Goldstein, Guillermo

    2012-07-01

    Hydraulic traits were studied for six Nothofagus species from South America (Argentina and Chile), and for three of these species two populations were studied. The main goal was to determine if properties of the water conductive pathway in stems and leaves are functionally coordinated and to assess if leaves are more vulnerable to cavitation than stems, consistent with the theory of hydraulic segmentation along the vascular system of trees in ecosystems subject to seasonal drought. Vulnerability to cavitation, hydraulic conductivity of stems and leaves, leaf water potential, wood density and leaf water relations were examined. Large variations in vulnerability to cavitation of stems and leaves were observed across populations and species, but leaves were consistently more vulnerable than stems. Water potential at 50% loss of maximum hydraulic efficiency (P(50)) ranged from -0.94 to -2.44 MPa in leaves and from -2.6 to -5.3 MPa in stems across species and populations. Populations in the driest sites had sapwood and leaves more vulnerable to cavitation than those grown in the wettest sites. Stronger diurnal down-regulation in leaf hydraulic conductance compared with stem hydraulic conductivity apparently has the function to slow down potential water loss in stems and protect stem hydraulics from cavitation. Species-specific differences in wood density and leaf hydraulic conductance (K(Leaf)) were observed. Both traits were functionally related: species with higher wood density had lower K(Leaf). Other stem and leaf hydraulic traits were functionally coordinated, resulting in Nothofagus species with an efficient delivery of water to the leaves. The integrity of the more expensive woody portion of the water transport pathway can thus be maintained at the expense of the replaceable portion (leaves) of the stem-leaf continuum under prolonged drought. Compensatory adjustments between hydraulic traits may help to decrease the rate of embolism formation in the trees more vulnerable to cavitation. PMID:22684354

  4. One-pot synthesis of molecular bottle-brush functionalized single-walled carbon nanotubes with superior dispersibility in water.

    Science.gov (United States)

    Deng, Yong; Hu, Qin; Yuan, Qiulin; Wu, Yan; Ling, Ying; Tang, Haoyu

    2014-01-01

    Molecular bottle-brush functionalized single-walled carbon nanotubes (SWCNTs) with superior dispersibility in water are prepared by a one-pot synthetic methodology. Elongating the main-chain and side-chain length of molecular bottle-brushes can further increase SWCNT dispersibility. They show significant enhancement of SWCNT dispersibility up to four times higher than those of linear molecular functionalized SWCNTs. PMID:24307218

  5. Numerical and experimental modeling of viscous fingering during liquid-liquid miscible displacement

    Energy Technology Data Exchange (ETDEWEB)

    Saghir, M.Z.; Chaalal, O. [UAE University Halifax, NS (United Arab Emirates); Islam, M.R. [Faculty of Engineering, Dalhousie University, B3J 2X4 Halifax, NS (Canada)

    2000-05-01

    Viscous fingering takes place when the viscous forces of a displacing phase has greater momentum than that of the displaced phase. Viscous fingering is an extremely important phenomenon in many applications of enhanced oil recovery, underground liquid waste disposal, and geothermal energy production. While the onset and propagation of viscous fingers during liquid-liquid displacement is considered to be of severe engineering consequences, little has been done to mathematically model the onset and propagation of a viscous finger. Viscous finger under double diffusive conditions is even less understood. In this paper, two-dimensional non-linear double diffusive convection in a multi-porous cavity is considered, both numerically and experimentally. The Darcy equation, including Brinkman term to account for the viscous effects, is used as the momentum balance equation. The model consists of two rectangular cavities filled with a porous medium. The smaller cavity is located at the top of the larger one. The larger cavity is filled initially with glycerin while the smaller one contains fresh water. At the initial time, the fresh water is injected with either constant flow rate (numerical) or constant hydrostatic head (experiments) and the viscous fingering formation is studied in details. The momentum, solutal, energy and continuity equations are solved numerically using the finite element technique. This transient problem is solved to study the thermal displacement, the isothermal displacement and the microgravity displacement of glycerin by water to understand the onset and the propagation of viscous fingering. For each case, the variation of the distance between the tip of the finger with time is studied in details. The effects of aspect ratio and displacement velocity are studied, both in the context of onset and propagation of viscous fingers. Experimentally, an ingenious method is developed for visualizing 2-D flow in a porous medium. A carbonate formation is used as the porous medium. Chemical dyeing is used to delineate the propagating front of a viscous finger. Initial series of experiments are conducted under isothermal conditions.

  6. Water

    Science.gov (United States)

    ... 1986 and 1996 amendments to the Safe Drinking Water Act ( http://www.epa.gov/safewater/sdwa/index.html ) ... for 1–2 minutes ; b . Then, fill a clean container(s) with water from this tap. This water will be suitable ...

  7. Rhetorics of Displacement: Constructing Identities in Forced Relocations

    Science.gov (United States)

    Powell, Katrina M.

    2012-01-01

    Forced displacement has often involved the use of rhetoric, both by government institutions and by people who struggle not only to survive displacement, but also to resist it. In this article, the author offers first a theoretical framework that informs her thinking about displacement narratives. She briefly examines two published displacement

  8. Forced displacement and women's security in Colombia.

    Science.gov (United States)

    Meertens, Donny

    2010-04-01

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

  9. Mathematical modelling of steam-water cycle with auxiliary empirical functions application

    Science.gov (United States)

    Szapajko, Grzegorz; Rusinowski, Henryk

    2010-09-01

    Research oriented on identification of operating states variations with the application of mathematical models of thermal processes has been developed in the field of energy processes diagnostics. Simple models, characterised by short calculation time, are necessary for thermal diagnostics needs. Such models can be obtained using empirical modelling methods. Good results brings the construction of analytical model with auxiliary empirical built-in functions. The paper presents a mathematical model of a steam-water cycle containing mass and energy balances and semiempirical models of steam expansion line in turbine as well as heat transfer in exchangers. A model of steam expansion line in a turbine is worked out with the application of a steam flow capacity equation and an internal efficiency of process equation for each group of stages for the analysed turbine. A model of a heat exchanger contains energy balance and the relation describing heat transfer in an exchanger, proposed by Beckman. Estimation of empirical equations coefficients was realised with the application of special and reliable measurements. Estimation criterion was a weighted relative sum of the remainder squares. There are exemplary calculations results presented in the final part of paper.

  10. Facile synthesis and functionalization of water-soluble gold nanoparticles for a bioprobe

    International Nuclear Information System (INIS)

    In this work, we report the size tunable synthesis of water-dispersed gold nanoparticles by using octadecylamine (ODA) as the reducing agent, that electrostatically complexes with the chloroaurate ions, reduces them, and subsequently caps the gold nanoparticles. Amine-capped gold nanoparticles, thus formed, were subsequently coordinated with a secondary monolayer of an anionic surfactant, sodium bis(2-ethylhexyl)-sulfosuccinate (AOT) which helps in providing sufficient hydrophilicity to the gold nanoparticles. Functionalized gold nanoparticles were characterized by UV-vis, IR spectrophotometric, dynamic light scattering, zeta-potential and transmission electron microscopic techniques, which demonstrated high stability of gold nanoparticles in aqueous media, indicating stabilization via bilayers of ODA and AOT. The gold nanoparticles were further conjugated with a protein (bovine serum albumin) and the interaction was investigated by circular dichroism studies as well as by measuring the fluorescence quenching of the tryptophan residues of protein molecules after the binding of nanoparticles to specific sites of the protein. The binding constant and the stoichiometry values indicated that the particles with larger core size are less site-specific but show higher binding affinity with protein molecules. The use of a bio-compatible synthetic process and the stabilization of the gold nanoparticles by ODA and AOT are interesting from the point of view of making bioprobes fom the point of view of making bioprobes for life science applications

  11. Density Functional Investigation of the Adsorption of Isooctane, Ethanol, and Acetic Acid on a Water-Covered Fe(100) Surface

    Science.gov (United States)

    2014-01-01

    The presence of water in biofuels poses the question of how it affects the frictional performance of additives in fuels containing organic substances. To investigate the effect of water on the adsorption of molecules present in fuel and its additives we simulated within the framework of density functional theory the adsorption of ethanol, isooctane (2,2,4-trimethylpentane), and acetic acid on a bare and a water-covered Fe(100) surface. Van der Waals interactions are taken into account in our computations. In those molecules, where dispersion forces contribute significantly to the binding mechanism, the water layer has a stronger screening effect. Additionally, this effect can be enhanced by the presence of polar functional groups in the molecule. Thus, with the introduction of a water layer, the adsorption energy of isooctane and ethanol is reduced but it is increased in the case of the acetic acid. The adsorption configuration of ethanol is changed, while the one of acetic acid is moderately, and for isooctane only very slightly altered. Therefore, the effect of a water layer in the adsorption of organic molecules on an Fe(100) surface strongly depends on the type of bond and consequently, so do the tribological properties. PMID:25243045

  12. Density Functional Investigation of the Adsorption of Isooctane, Ethanol, and Acetic Acid on a Water-Covered Fe(100) Surface.

    Science.gov (United States)

    Bedolla, Pedro O; Feldbauer, Gregor; Wolloch, Michael; Gruber, Christoph; Eder, Stefan J; Dörr, Nicole; Mohn, Peter; Redinger, Josef; Vernes, András

    2014-09-18

    The presence of water in biofuels poses the question of how it affects the frictional performance of additives in fuels containing organic substances. To investigate the effect of water on the adsorption of molecules present in fuel and its additives we simulated within the framework of density functional theory the adsorption of ethanol, isooctane (2,2,4-trimethylpentane), and acetic acid on a bare and a water-covered Fe(100) surface. Van der Waals interactions are taken into account in our computations. In those molecules, where dispersion forces contribute significantly to the binding mechanism, the water layer has a stronger screening effect. Additionally, this effect can be enhanced by the presence of polar functional groups in the molecule. Thus, with the introduction of a water layer, the adsorption energy of isooctane and ethanol is reduced but it is increased in the case of the acetic acid. The adsorption configuration of ethanol is changed, while the one of acetic acid is moderately, and for isooctane only very slightly altered. Therefore, the effect of a water layer in the adsorption of organic molecules on an Fe(100) surface strongly depends on the type of bond and consequently, so do the tribological properties. PMID:25243045

  13. Water and potassium metabolism in functional disturbances of the thyroid gland

    International Nuclear Information System (INIS)

    Total body water, extracellular water (bromide space), plasma volume and total potassium were evaluated in hypothyroid (n=24) and hyperthyroid (n=18) patients and in controls (n=10). Whereas the relative extracellular water was the same in all groups investigated, the relative intracellular water was found to be reduced in hyperthyroidism and increased in hypothyroidism (p4) is thought to be attributable to an alteration of the lean body mass. (orig.)

  14. Water-Metal Surfaces : Insights from core-level spectroscopy and density functional theory

    OpenAIRE

    Schiros, Theanne

    2008-01-01

    Computational methods are combined with synchrotron-based techniques to analyze the structure and bonding of water and water plus hydroxyl at metal surfaces under UHV and at near-ambient conditions. Water-metal interaction plays a crucial role in a multitude of cosmic, atmospheric and biological phenomena as well as heterogeneous catalysis, electrochemistry and corrosion. A spotlight of renewed interest has recently been cast on water-metal systems due to their relevance for surface chemical ...

  15. Development of Protein-Functionalized Magnetic Iron Oxide Nanoparticles: Potential Application in Water Treatment

    OpenAIRE

    Okoli, Chuka

    2012-01-01

    The treatment of water to make it safe for human consumption is a problem of immense concern, both in developing and developed countries. However, the production of clean water with chemicals as coagulants has several drawbacks associated with cost, health risks and complexity in sludge management. The application of nanotechnology in water treatment is a fast growing discipline proposed as an efficient alternative that will combat these hurdles. The aim of this thesis is to develop new water...

  16. Passive Smoking in a Displacement Ventilated Room

    DEFF Research Database (Denmark)

    BjØrn, Erik; Nielsen, Peter V.

    1997-01-01

    The aim of this research is to see if the displacement ventilation principle can protect a person from exposure to passive tobacco smoking. This is done by full-scale experiments with two breathing thermal manikins, smoke visualisations, and tracer gas measurements. In some situations, exhaled smoke will stratify in a certain height due to the vertical temperature gradient. This horizontal layer of exhaled tobacco smoke may lead to exposure. In other situations, the smoke is mixed into the upper zone, and the passive smoker is protected to some extent by the displacement principle and the convective boundary layer flow around the body.

  17. Displacement Echoes: Classical Decay and Quantum Freeze

    International Nuclear Information System (INIS)

    Motivated by neutron scattering experiments, we investigate the decay of the fidelity with which a wave packet is reconstructed by a perfect time-reversal operation performed after a phase-space displacement. In the semiclassical limit, we show that the decay rate is generically given by the Lyapunov exponent of the classical dynamics. For small displacements, we additionally show that, following a short-time Lyapunov decay, the decay freezes well above the ergodic value because of quantum effects. Our analytical results are corroborated by numerical simulations

  18. DNA fork displacement rates in human cells

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    AlexanderGarthe

    2013-05-01

    Full Text Available 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 review we discuss evidence that the large diversity of protocols and setups used is an important aspect in interpreting the differences in the results that have been obtained. Even simple parameters such as pool size, number and configuration of visual landmarks, or number of trials can become highly relevant for getting the new neurons involved at all. Sets of parameters are often chosen with implicit or explicit concepts in mind and these might lead to different views on the function of adult-generated neurons. We propose that the classical parameters usually used to measure spatial learning performance in the water maze might not be particularly well suited to sensitively and specifically detect the supposedly highly specific functional changes elicited by the experimental modulation of adult hippocampal neurogenesis. As adult neurogenesis is supposed to affect specific aspects of information processing only in the hippocampus, any claim for a functional relevance of the new neurons has to be based on hippocampus-specific parameters. We also placed a special emphasis on the fact that the DG facilitates the differentiation between contexts as opposed to just differentiating places. In conclusion, while the Morris water maze has proven to be one of the most effective testing paradigms to assess hippocampus-dependent spatial learning, new and more specific questions ask for new parameters. Therefore, the full potential of the water maze task remains to be tapped.

  20. Equilibrium isotopic fractionation in the kaolinite, quartz, water system: Prediction from first-principles density-functional theory

    Science.gov (United States)

    Méheut, Merlin; Lazzeri, Michele; Balan, Etienne; Mauri, Francesco

    2007-07-01

    Isotopic fractionation factors for oxygen, hydrogen and silicon have been calculated using first-principles methods for the kaolinite, quartz, water (ice and gas water) system. Good agreement between theory and experiment is obtained for mineral-water oxygen isotope fractionation. This approach gives reliable results on isotopic fractionation factors as a function of temperature, within a relative precision of typically 5%. These calculations provide independent quantitative constraints on the internal fractionation of oxygen in kaolinite, the fractionation of silicon isotopes at equilibrium, or hydrogen fractionation between kaolinite and water. Calculated fractionation factors at 300 K are 12.5‰ for the kaolinite internal-fractionation of oxygen, and 1.6‰ for silicon fractionation between quartz and kaolinite.

  1. Micro-pixel accuracy centroid displacement estimation and detector calibration

    CERN Document Server

    Zhai, Chengxing; Goullioud, Renaud; Nemati, Bijan

    2011-01-01

    Precise centroid estimation plays a critical role in accurate astrometry using telescope images. Conventional centroid estimation fits a template point spread function (PSF) to the image data. Because the PSF is typically not known to high accuracy due to wavefront aberrations and uncertainties in optical system, a simple Gaussian function is commonly used. PSF knowledge error leads to systematic errors in the conventional centroid estimation. In this paper, we present an accurate centroid estimation algorithm by reconstructing the PSF from well sampled (above Nyquist frequency) pixelated images. In the limit of an ideal focal plane array whose pixels have identical response function (no inter-pixel variation), this method can estimate centroid displacement between two 32$\\times$32 images to sub-micropixel accuracy. Inter-pixel response variations exist in real detectors, {\\it e.g.}~CCDs, which we can calibrate by measuring the pixel response of each pixel in Fourier space. The Fourier transforms of the inter...

  2. Effects of Temperature on Immiscible Displacement of a Viscous NAPL

    Science.gov (United States)

    O'Carroll, D. M.; Sleep, B. E.

    2005-12-01

    Thermal remediation techniques, such as hot water flooding, are emerging technologies that have been proposed to remove significant amounts of nonaqueous phase liquids (NAPLs) from the subsurface. These techniques were originally developed in the petroleum industry for enhanced petroleum recovery and later adapted for the remediation of NAPL contaminated sites. Hot water flooding exploits the temperature dependence of fluid properties, such as viscosity and interfacial tension, to improve NAPL removal efficiencies. Improved NAPL removal efficiencies result in reduced source longevity. Although hot water flooding has been applied at various remediation field sites it has received relatively little laboratory study in the contaminant hydrology community. This presentation describes results of a laboratory and modeling investigation designed to determine if hot water flooding techniques improve NAPL mass removal when compared to ambient temperature water flushing. Experiments were conducted in a bench scale two-dimensional sandbox (55 cm by 45 cm by 1.3 cm) and NAPL saturations were quantified using a light transmission apparatus in conjunction with a 14 bit CCD camera (1536 x 1024 pixels).Two immiscible displacement experiments were conducted in which the aqueous phase displaced a NAPL saturated zone. In the first experiment fluids were at ambient temperature (22 oC) and in the second fluid temperatures were elevated to approximately 50 oC. The hydraulic properties of the selected LNAPL, Voltesso 35, are strongly temperature dependent. At 50 oC Voltesso35 viscosity is 30 % of its value at ambient temperatures and the aqueous phase/Voltesso 35 interfacial tension is 83 % of its value at ambient temperatures. Experimental results of both the cold and hot water flooding experiments will be presented. A numerical simulator has been modified to include simultaneous flow of water and organic phases, energy transport, temperature and pressure. Model predictions of mass removal and NAPL saturation profiles compare well with observed behavior. A sensitivity analysis will be presented, exploring the temperature dependency of NAPL hydraulic properties, to assess the conditions under which it is advantageous to employ hot water flooding techniques.

  3. Common characteristics of displacive and relaxor ferroelectrics.

    Czech Academy of Sciences Publication Activity Database

    Bishop, A. R.; Bussmann-Holder, A.; Kamba, Stanislav; Maglione, M.

    2010-01-01

    Ro?. 81, ?. 6 (2010), 064106/1-064106/9. ISSN 1098-0121 R&D Projects: GA ?R(CZ) GA202/09/0682 Institutional research plan: CEZ:AV0Z10100520 Keywords : relaxor ferroelectrics * soft modes * breather * displacive phase transition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.772, year: 2010

  4. Education: protecting the rights of displaced children

    Directory of Open Access Journals (Sweden)

    Suba Mahalingam

    2002-10-01

    Full Text Available UNICEF and its partners work with displaced communitiesto provide material assistance and protection, using as their basis the UN Convention on the Rights of the Child1 and other internationallegal instruments. Education has proven a valuable tool in this effort, not only making children aware of their rights but also providing a way to participate in the realisation of these rights.

  5. Opening Doors for the Displaced Worker.

    Science.gov (United States)

    Moore, Martha Norris

    2000-01-01

    Describes the many benefits now available to laid-off and displaced textile and apparel-related workers through the North American Free Trade Agreement's Transitional Adjustment Allowance (NAFTA-TAA), which allows them to attend college for the first time. Examines the effectiveness of the TAA program and concludes that there is room for "cautious…

  6. Olympic scale of sport-induced displacement

    Directory of Open Access Journals (Sweden)

    Jean du Plessis

    2007-07-01

    Full Text Available The Olympic Games have displaced more than two million people in the last 20 years, disproportionately affecting particular groups such as the homeless, the poor, Roma and African-Americans. Mega-events such as the Olympic Games often leave a negative housing legacy for local populations.

  7. Displacement Damage in Bipolar Linear Integrated Circuits

    Science.gov (United States)

    Rax, B. G.; Johnston, A. H.; Miyahira, T.

    2000-01-01

    Although many different processes can be used to manufacture linear integrated circuits, the process that is used for most circuits is optimized for high voltage -- a total power supply voltage of about 40 V -- and low cost. This process, which has changed little during the last twenty years, uses lateral and substrate p-n-p transistors. These p-n-p transistors have very wide base regions, increasing their sensitivity to displacement damage from electrons and protons. Although displacement damage effects can be easily treated for individual transistors, the net effect on linear circuits can be far more complex because circuit operation often depends on the interaction of several internal transistors. Note also that some circuits are made with more advanced processes with much narrower base widths. Devices fabricated with these newer processes are not expected to be significantly affected by displacement damage for proton fluences below 1 x 10(exp 12) p/sq cm. This paper discusses displacement damage in linear integrated circuits with more complex failure modes than those exhibited by simpler devices, such as the LM111 comparator, where the dominant response mode is gain degradation of the input transistor. Some circuits fail catastrophically at much lower equivalent total dose levels compared to tests with gamma rays. The device works satisfactorily up to nearly 1 Mrad(Si) when it is irradiated with gamma rays, but fails catastrophically between 50 and 70 krad(Si) when it is irradiated with protons.

  8. Displacing Media: LCD LAB Artistic Residency

    OpenAIRE

    Filipe Pais

    2012-01-01

    This review refers to an artistic residency which took place at LCD LAB -  CAAA at Guimarães, in March, exploring a strategy for media art called Media Displacement. The text introduces the strategy very briefly and describes the residency's organization, structure, processses and the results produced.

  9. Displacing Media: LCD LAB Artistic Residency

    Directory of Open Access Journals (Sweden)

    Filipe Pais

    2012-12-01

    Full Text Available This review refers to an artistic residency which took place at LCD LAB -  CAAA at Guimarães, in March, exploring a strategy for media art called Media Displacement. The text introduces the strategy very briefly and describes the residency's organization, structure, processses and the results produced.

  10. Rotational melting in displacive quantum paraelectrics

    International Nuclear Information System (INIS)

    Displacive quantum paraelectrics are discussed as possible realizations of rotational quantum melting. The phenomenology of SrTiO3 and KTaO3 is discussed in this light. Both old and fresh theoretical work on two-dimensional lattice models for quantum paraelectricity is reviewed. (author). 73 refs, 15 figs

  11. Functional and histologic assessment of rat gastric mucosa after chronic treatment with sulphurous thermal water.

    Science.gov (United States)

    Coruzzi, Gabriella; Adami, Maristella; Pozzoli, Cristina; Solenghi, Elvira; Grandi, Daniela

    2010-01-01

    The effect of a chronic (4 weeks) administration of sulphurous thermal water on gastric acid secretion and mucosal defense was investigated in rats. Animals were randomized to receive daily intake of tap water or of thermal water obtained from a local spa center (Tabiano, Parma, Italy). Rats were followed for one month as for water and food consumption, body weight and general conditions. At the end of the watering period, the following study protocols were carried out: (a) study of basal and stimulated gastric acid secretion under general anesthesia, and (b) study of the gastric mucosal resistance against the damage induced by ethanol and indomethacin in conscious rats. Basal acid secretion and the acid response to pentagastrin or to histamine were similar in rats assuming ordinary drinking water or thermal water. As for resistance to gastric damage, histological, but not macroscopic, evaluation revealed that rats which assumed thermal water were slightly more resistant to the gastrolesive effect of ethanol (either absolute or diluted). Again, when indomethacin was used as a noxious stimulus, no difference was noted between the two groups as for macroscopic damage; only a nonsignificant reduction of damage was observed histologically in stomachs of rats assuming thermal water. In conclusion, these results indicate that chronic treatment of rats with thermal water, rich in sulphur compounds, may have only minimal effects on the rat gastric mucosa and did not significantly affect mucosal defense mechanisms. The observed tendency to gastroprotection would possibly need further investigation with longer periods of administration. PMID:20145426

  12. Displacement and stress fields around rock fractures opened by irregular overpressure variations

    Directory of Open Access Journals (Sweden)

    ShigekazuKusumoto

    2014-05-01

    Full Text Available Many rock fractures are entirely driven open by fluids such as ground water, geothermal water, gas, oil, and magma. These are a subset of extension fractures (mode I cracks; e.g., dikes, mineral veins and joints referred to as hydrofractures. Field measurements show that many hydrofractures have great variations in aperture. However, most analytical solutions for fracture displacement and stress fields assume the loading to be either constant or with a linear variation. While these solutions have been widely used, it is clear that a fracture hosted by heterogeneous and anisotropic rock is normally subject to loading that is neither constant nor with a linear variation. Here we present new general solutions for the displacement and stress fields around hydrofractures, modelled as two-dimensional elastic cracks, opened by irregular overpressure variations given by the Fourier cosine series. Each solution has two terms. The first term gives the displacement and stress fields due to the average overpressure acting inside the crack; it is given by the initial term of the Fourier coefficients expressing the overpressure variation. The second term gives the displacement and stress fields caused by the overpressure variation; it is given by general terms of the Fourier coefficients and solved through numerical integration. Our numerical examples show that the crack aperture variation closely reflects the overpressure variation. Also, that the general displacement and stress fields close to the crack follow the overpressure variation but tend to be more uniform far from the crack. The present solutions can be used to estimate the displacement and stress fields around any fluid-driven crack, that is, any hydrofracture, as well as its aperture, provided the variation in overpressure can be described by Fourier series. The solutions add to our understanding of local stresses, displacements, and fluid transport associated with hydrofractures in the crust.

  13. Density functional theory of water-gas shift reaction on molybdenum carbide.

    Science.gov (United States)

    Tominaga, Hiroyuki; Nagai, Masatoshi

    2005-11-01

    The density functional theory (DFT) of the water-gas shift (WGS) reaction over molybdenum carbide was studied with the aim of understanding the dissociation of H(2)O, the OH group, and CO to determine on what sections of molybdenum carbide CO(2) and H(2) formed and whether they played a role in the reaction. The energy diagram of each elementary step, the reaction of the hydrogen and oxygen atoms with CO, and the transition state for this elementary step were also studied. The IR spectra of the CO adsorption was experimentally analyzed for the identification of several candidates of the CO adsorption modes. The adsorptions of the threefold Mo site (a) with and (b) without the underlying C atom of the second layer have the second and highest adsorption energies of -281.59 and -321.00 kJ/mol, respectively. The IR data showed that the bands at 1626 cm(-1) from the IR experiments are (a) the nearest adsorption of the threefold Mo site with the underlying C atom at the calculated/corrected band of 1621 cm(-1). The calculated/corrected threefold adsorption (b) had the highest adsorption energy but exhibited an IR band at 1147 cm(-1) which was not observed in the experimental data. The C-O bond length increased to 1.49 from 1.36 after the H(2)O adsorption (b), suggesting the dissociation of C-O after the H(2)O coadsorption. The WGS reaction on the beta-Mo(2)C(001) slab carbide was calculated and took place as follows: H(2)O was dissociated into OH and H on the Mo(2)C surface and the OH subsequently dissociated into H and O atoms. CO approached the O atom to form CO(2). PMID:16853642

  14. Inversion of the volume scattering function and spectral absorption in coastal waters with biogeochemical implications

    Directory of Open Access Journals (Sweden)

    X. Zhang

    2013-06-01

    Full Text Available In the aquatic environment, particles can be broadly separated into phytoplankton (PHY, non-algal particle (NAP and dissolved (or very small particle, VSP fractions. Typically, absorption spectra are inverted to quantify these fractions, but volume scattering functions (VSFs can also be used. Both absorption spectra and VSFs were used to calculate particle fractions for an experiment in Chesapeake Bay. A complete set of water inherent optical properties was measured using a suite of commercial instruments and a prototype Multispectral Volume Scattering Meter (MVSM; the chlorophyll concentration, [Chl] was determined using the HPLC method. The total scattering coefficient (measured by an ac-s and the VSF (at a few backward angles, measured by a HydroScat 6 and an ECO-VSF agreed with the LISST and MVSM data within 5%, thus indicating inter-instrument consistency. The size distribution and scattering parameters for PHY, NAP and VSP were inverted from measured VSFs. For the absorption inversion, the "dissolved" absorption spectra were measured for filtrate passing through a 0.2 ?m filter, whereas [Chl] and NAP absorption spectra were inverted from the particulate fraction. Even though the total scattering coefficient showed no correlation with [Chl], estimates of [Chl] from the VSF-inversion agreed well with the HPLC measurements (r = 0.68, mean relative error s = ?20%. The scattering associated with NAP and VSP both correlated well with the NAP and "dissolved" absorption coefficients, respectively. While NAP dominated forward, and hence total, scattering, our results also suggest that the scattering by VSP was far from negligible and dominated backscattering.

  15. Effects of sulfation on the physicochemical and functional properties of a water-insoluble polysaccharide preparation from Ganoderma lucidum.

    Science.gov (United States)

    Liu, Wei; Wang, Hengyu; Yao, Wenbing; Gao, Xiangdong; Yu, Liangli Lucy

    2010-03-24

    The sulfation of a water-insoluble Ganoderma lucidum polysaccharide (GLP) was successfully carried out with chlorosulfonic acid-pyridine in dimethyl formamide to prepare three sulfated GLP derivatives, named sGLP1, sGLP2, and sGLP3. The chemical structure of the sulfated GLP was confirmed by Fourier transform infrared and (13)C NMR analyses. The sGLPs were evaluated for their water solubility, degree of substitution (DS), antioxidant properties, and bile acid-binding capacities. The results showed that sulfation improved the water solubility of GLP and increased its scavenging capacities against hydroxyl and superoxide anion radicals, hydrogen peroxide-scavenging activity, Fe(II) chelating ability, reducing power, and bile acid-binding capacities. It was also observed that the DS may influence the physicochemical and functional properties of sGLPs. For instance, the sulfated GLP with the lowest DS had the greatest bile acid-binding capacity, and the sGLP that had the highest DS showed the lowest bile acid-binding ability under the experimental conditions. The results from this study suggested that sulfation is a possible approach to obtain novel water-soluble derivatives of GLP with improved physicochemical, functional, and biological properties for potential utilization in functional foods or supplemental products. PMID:20163182

  16. Functional interactions in bacteriorhodopsin: a theoretical analysis of retinal hydrogen bonding with water.

    OpenAIRE

    Nina, M.; Roux, B.; Smith, J. C.

    1995-01-01

    The light-driven proton pump, bacteriorhodopsin (bR) contains a retinal molecule with a Schiff base moiety that can participate in hydrogen-bonding interactions in an internal, water-containing channel. Here we combine quantum chemistry and molecular mechanics techniques to determine the geometries and energetics of retinal Schiff base-water interactions. Ab initio molecular orbital calculations are used to determine potential surfaces for water-Schiff base hydrogen-bonding and to characteriz...

  17. Modelling water table levels to integrate wetland management and ecosystem functions

    Science.gov (United States)

    Acreman, M.; Bradford, R.

    2003-04-01

    The Somerset Levels and Moors (UK) contain a range of wetland types with different management regimes, including important areas of wet grassland habitats. A groundwater flow model, MODFLOW, is applied at the field-scale to predict spatial and temporal variations in water table levels. The results are used for a range of applications, including the impact of controlled water levels for the conflicting water requirements of agriculture and biodiversity and to assist the study of microbial activity that controls methane production.

  18. Displacement of D1, HP1 and topoisomerase II from satellite heterochromatin by a specific polyamide

    OpenAIRE

    Blattes, Roxane; Monod, Caroline; Susbielle, Guillaume; Cuvier, Olivier; Wu, Jian-hong; Hsieh, Tao-shih; Laemmli, Ulrich K.; Ka?s, Emmanuel

    2006-01-01

    The functions of DNA satellites of centric heterochromatin are difficult to assess with classical molecular biology tools. Using a chemical approach, we demonstrate that synthetic polyamides that specifically target AT-rich satellite repeats of Drosophila melanogaster can be used to study the function of these sequences. The P9 polyamide, which binds the X-chromosome 1.688 g/cm3 satellite III (SAT III), displaces the D1 protein. This displacement in turn results in a selective loss of HP1 and...

  19. Wettability Control on Fluid-Fluid Displacements in Patterned Microfluidics

    Science.gov (United States)

    Zhao, B.; Trojer, M.; Cueto-Felgueroso, L.; Juanes, R.

    2014-12-01

    Two-phase flow in porous media is important in many natural and industrial processes like geologic CO2 sequestration, enhanced oil recovery, and water infiltration in soil. While it is well known that the wetting properties of porous media can vary drastically depending on the type of media and the pore fluids, the effect of wettability on fluid displacement continues to challenge our microscopic and macroscopic descriptions. Here we study this problem experimentally, starting with the classic experiment of two-phase flow in a capillary tube. We image the shape of the meniscus and measure the associated capillary pressure for a wide range of capillary numbers. We confirm that wettability exerts a fundamental control on meniscus deformation, and synthesize new observations on the dependence of the dynamic capillary pressure on wetting properties (contact angle) and flow conditions (viscosity contrast and capillary number). We compare our experiments to a macroscopic phase-field model of two-phase flow. We use the insights gained from the capillary tube experiments to explore the viscous fingering instability in the Hele-Shaw geometry in the partial-wetting regime. A key difference between a Hele-Shaw cell and a porous medium is the existence of micro-structures (i.e. pores and pore throats). To investigate how these micro-structrues impact fluid-fluid displacement, we conduct experiments on a planar microfluidic device patterned with vertical posts. We track the evolution of the fluid-fluid interface and elucidate the impact of wetting on the cooperative nature of fluid displacement during pore invasion events. We use the insights gained from the capillary tube and patterned microfluidics experiments to elucidate the effect of wetting properties on viscous fingering and capillary fingering in a Hele-Shaw cell filled with glass beads, where we observe a contact-angle-dependent stabilizing behavior for the emerging flow instabilities, as the system transitions from drainage to imbibition.

  20. Present Situation Research on Axial Flow Displacement Theory During Cementing

    Directory of Open Access Journals (Sweden)

    AI Chi

    2014-01-01

    Full Text Available It is well known that displacing drilling fluid effectively is the premise to obtain good cementing quality. During cementing axial flow is the major way to displace annular drilling fluid. So we put emphasis on the research of axial flow displacement theory. At present axial flow displacement theory mainly focuses on three aspects: displacement theory study based on wall shear stress; displacement theory study based on the numerical simulation technique for the displacement interface stability; displacement theory study based on laboratory experiments. In this paper, we analyzes the present research situation and their respective advantages and defects of the above mentioned three aspects in displacement theory. We put forward that infinitesimal mechanical analysis for displacement interface and numerical simulation technology for the interface stability should combine organically. In order to achieve good cementing effect, we should stress on the research and measurement of profile displacement efficiency and put the interface moving steadily as a prerequisite. As a result, our research can lay a fundamental the future development of axial flow displacement theory.Key words: Axial flow; Displacement theory; Wall shear stress; Interface stability; Displacement efficiency

  1. Aerogels from quaternary ammonium-functionalized cellulose nanofibers for rapid removal of Cr(VI) from water.

    Science.gov (United States)

    He, Xu; Cheng, Long; Wang, Yaru; Zhao, Jiangqi; Zhang, Wei; Lu, Canhui

    2014-10-13

    An efficient heavy metal adsorbent from quaternary ammonium-functionalized cellulose nanofiber aerogels was successfully developed. The highly porous aerogel could well retain its large specific surface area, which allowed rapid and effective removal of Cr(VI) from contaminated water. The aerogel adsorbent became mechanically robust after chemical crosslinking. It could be easily separated from water after adsorption without complicated centrifugation or filtration process. With only 1g of aerogel, more than 99% of Cr(VI) in 1L of 1mg/L solution could be removed in 50 min. Besides, the aerogel also exhibited excellent reusability. PMID:25037403

  2. Interaction potential for water dimer from symmetry-adapted perturbation theory based on density functional description of monomers

    Science.gov (United States)

    Bukowski, Robert; Szalewicz, Krzysztof; Groenenboom, Gerrit; van der Avoird, Ad

    2006-07-01

    A new six-dimensional interaction potential for the water dimer has been obtained by fitting interaction energies computed at 2510 geometries using a variant of symmetry-adapted perturbation theory (SAPT) based on density functional theory (DFT) description of monomers, referred to as SAPT(DFT). The stationary points, second virial coefficient, vibration-rotation-tunneling spectrum, and structure of liquid water computed with the new potential are in very good agreement with experiment and advanced ab initio calculations, confirming the high level of accuracy provided by SAPT(DFT).

  3. Functionalization of graphene and grafting of temperature-responsive surfaces from graphene by ATRP 'on water'

    Energy Technology Data Exchange (ETDEWEB)

    Ren Lulu; Huang Shu; Zhang Chao; Wang Ruiyu [Fudan University, State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science (China); Tjiu, Weng Weei [Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A-STAR) (Singapore); Liu Tianxi, E-mail: txliu@fudan.edu.cn [Fudan University, State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science (China)

    2012-06-15

    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, {sup 1}H 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.

  4. Specific leaf areas of the tank bromeliad Guzmania monostachia perform distinct functions in response to water shortage.

    Science.gov (United States)

    Freschi, Luciano; Takahashi, Cassia Ayumi; Cambui, Camila Aguetoni; Semprebom, Thais Ribeiro; Cruz, Aline Bertinatto; Mioto, Paulo Tamoso; de Melo Versieux, Leonardo; Calvente, Alice; Latansio-Aidar, Sabrina Ribeiro; Aidar, Marcos Pereira Marinho; Mercier, Helenice

    2010-05-01

    Leaves comprise most of the vegetative body of tank bromeliads and are usually subjected to strong longitudinal gradients. For instance, while the leaf base is in contact with the water accumulated in the tank, the more light-exposed middle and upper leaf sections have no direct access to this water reservoir. Therefore, the present study attempted to investigate whether different leaf portions of Guzmania monostachia, a tank-forming C(3)-CAM bromeliad, play distinct physiological roles in response to water shortage, which is a major abiotic constraint in the epiphytic habitat. Internal and external morphological features, relative water content, pigment composition and the degree of CAM expression were evaluated in basal, middle and apical leaf portions in order to allow the establishment of correlations between the structure and the functional importance of each leaf region. Results indicated that besides marked structural differences, a high level of functional specialization is also present along the leaves of this bromeliad. When the tank water was depleted, the abundant hydrenchyma of basal leaf portions was the main reservoir for maintaining a stable water status in the photosynthetic tissues of the apical region. In contrast, the CAM pathway was intensified specifically in the upper leaf section, which is in agreement with the presence of features more suitable for the occurrence of photosynthesis at this portion. Gas exchange data indicated that internal recycling of respiratory CO(2) accounted for virtually all nighttime acid accumulation, characterizing a typical CAM-idling pathway in the drought-exposed plants. Altogether, these data reveal a remarkable physiological complexity along the leaves of G. monostachia, which might be a key adaptation to the intermittent water supply of the epiphytic niche. PMID:19954859

  5. Study of fast neutron scattering. The displacement cross-section (1962)

    International Nuclear Information System (INIS)

    We propose a method for calculating the biological efficiency of fast neutrons emitted by in-pile fission sources. This method justifies the empirical theory of Albert and Welton. In making simple assumptions concerning the cross-sections, we have supposed that the propagation can ben reduced to a mono-kinetic problem. A system of orthonormal functions is then set up making it possible to calculate the flux leaving a planar source. This method generalises the results obtained by Platzek to the case where the elastic cross-sections are not isotropic, and make it possible in particular to define a displacement cross-section: extension of the diffusion coefficient. This method can be generalised to the case of neutron diffraction as a function of time, and to the study of slowing-down. Numerical results are given in an appendix for the following: H2O, D2O, Fe, Be, Pb, CH, CH2. These cross-sections have been verified experimentally in water and in graphite for neutrons of 2.5 and 14 MeV using a SAMES accelerator and a 2 MeV Van De Graaff. (author)

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

    OpenAIRE

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

    2012-01-01

    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 (pedo)transfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which account...

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

    OpenAIRE

    Moeys, J.; Larsbo, M.; Bergstro?m, L.; Brown, C. D.; Coquet, Y.; Jarvis, N. J.

    2012-01-01

    Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisations usually rely on a set of lookup tables and (pedo)transfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accoun...

  8. Holding Water in the Landscape; striking a balance between food production and healthy catchment function

    Science.gov (United States)

    Quinn, Paul; Wilkinson, Mark; Stutter, Marc; Adams, Russell

    2015-04-01

    Here it is proposed that ~5 % of the rural landscape could be modified to hold water during storm events. Hence ~95% of land remains for food production, commercial forestry and amenity. This is a catchment scale commitment to sustainably reducing flood and drought risk, improving water quality, biodiversity and thereby climate proofing our catchments. The farmed landscape has intensified and as a result, runoff rates are no longer in balance with the catchment needs, which in turn contributes to floods, droughts and water pollution problems. The loss of infiltration rates, soil water holding capacity and the increase in ditches and drains through intense farming has resulted in a reduction of the overall water holding capacity of the landscape, therefore deeper soil and aquifer recharge rates are lower. However, adequate raw water supply and food production is also vital. Here we consider how ~5% of productive land could be used to physically hold water during and after storms. This is a simple philosophy for water stewardship that could be delivered by farmers and land managers themselves. In this poster we consider a 'treatment train' of mitigation in headwaters by the construction of:- Rural SuDs - by creating swales, bunds and grassy filters; Buffer Strips - (designed to hold water); The Ditch of The Future - by creating the prime location for holding water and recovering lost top soil and finally the better use of Small Headwater Floodplains - by storing flood water, creating wetlands, planting new forest, installing woody debris and new habitats. We present examples of where and how these measures have been installed and show the cost-effectiveness of temporarily holding storm runoff in several case study catchments taken from the UK.

  9. Experimental study of miscible displacement fronts in rough self-affine fractures.

    Science.gov (United States)

    Auradou, H; Hulin, J P; Roux, S

    2001-06-01

    Miscible fluid displacements are studied experimentally in a radial flow between two complementary replica of a self-affine rough granite fracture surface. The displacement front between a dyed fluid and a transparent (but otherwise identical) one is followed optically through one face of the cell. The evolution of its geometry is studied as a function of time, flow-rate, and normal and lateral relative displacements between the two surfaces. For a purely normal displacement, the front is globally smooth, due to the constant local distance between surfaces. For a finite lateral displacement, the front is rough due to spatial variations of this distance; its geometry is fractal and its dimension is directly related to the Hurst exponent H approximately 0.8 of the surface. The fractal regime is observed only above a lower cut-off scale that depends on the normal spacing of the surfaces and an upper one that increases with the injected volume and with the amplitude of the lateral displacement. PMID:11415226

  10. Noise analysis and improvement of displacement vector estimation from angular displacements

    OpenAIRE

    Chen, Hao; Varghese, Tomy

    2008-01-01

    Elastography or elasticity imaging techniques typically image local strains or Young’s modulus variations along the insonification direction. Recently, techniques that utilize angular displacement estimates obtained from multiple angular insonification of tissue have been reported. Angular displacement estimates obtained along different angular insonification directions have been utilized for spatial-angular compounding to reduce noise artifacts in axial-strain elastograms, and for estimati...

  11. Displacement fields from point cloud data: Application of particle imaging velocimetry to landslide geodesy

    Science.gov (United States)

    Aryal, Arjun; Brooks, Benjamin A.; Reid, Mark E.; Bawden, Gerald W.; Pawlak, Geno R.

    2012-03-01

    Acquiring spatially continuous ground-surface displacement fields from Terrestrial Laser Scanners (TLS) will allow better understanding of the physical processes governing landslide motion at detailed spatial and temporal scales. Problems arise, however, when estimating continuous displacement fields from TLS point-clouds because reflecting points from sequential scans of moving ground are not defined uniquely, thus repeat TLS surveys typically do not track individual reflectors. Here, we implemented the cross-correlation-based Particle Image Velocimetry (PIV) method to derive a surface deformation field using TLS point-cloud data. We estimated associated errors using the shape of the cross-correlation function and tested the method's performance with synthetic displacements applied to a TLS point cloud. We applied the method to the toe of the episodically active Cleveland Corral Landslide in northern California using TLS data acquired in June 2005-January 2007 and January-May 2010. Estimated displacements ranged from decimeters to several meters and they agreed well with independent measurements at better than 9% root mean squared (RMS) error. For each of the time periods, the method provided a smooth, nearly continuous displacement field that coincides with independently mapped boundaries of the slide and permits further kinematic and mechanical inference. For the 2010 data set, for instance, the PIV-derived displacement field identified a diffuse zone of displacement that preceded by over a month the development of a new lateral shear zone. Additionally, the upslope and downslope displacement gradients delineated by the dense PIV field elucidated the non-rigid behavior of the slide.

  12. Translational diffusion of hydration water correlates with functional motions in folded and intrinsically disordered proteins

    Science.gov (United States)

    Schirò, Giorgio; Fichou, Yann; Gallat, Francois-Xavier; Wood, Kathleen; Gabel, Frank; Moulin, Martine; Härtlein, Michael; Heyden, Matthias; Colletier, Jacques-Philippe; Orecchini, Andrea; Paciaroni, Alessandro; Wuttke, Joachim; Tobias, Douglas J.; Weik, Martin

    2015-03-01

    Hydration water is the natural matrix of biological macromolecules and is essential for their activity in cells. The coupling between water and protein dynamics has been intensively studied, yet it remains controversial. Here we combine protein perdeuteration, neutron scattering and molecular dynamics simulations to explore the nature of hydration water motions at temperatures between 200 and 300?K, across the so-called protein dynamical transition, in the intrinsically disordered human protein tau and the globular maltose binding protein. Quasi-elastic broadening is fitted with a model of translating, rotating and immobile water molecules. In both experiment and simulation, the translational component markedly increases at the protein dynamical transition (around 240?K), regardless of whether the protein is intrinsically disordered or folded. Thus, we generalize the notion that the translational diffusion of water molecules on a protein surface promotes the large-amplitude motions of proteins that are required for their biological activity.

  13. Translational diffusion of hydration water correlates with functional motions in folded and intrinsically disordered proteins

    Science.gov (United States)

    Schirò, Giorgio; Fichou, Yann; Gallat, Francois-Xavier; Wood, Kathleen; Gabel, Frank; Moulin, Martine; Härtlein, Michael; Heyden, Matthias; Colletier, Jacques-Philippe; Orecchini, Andrea; Paciaroni, Alessandro; Wuttke, Joachim; Tobias, Douglas J.; Weik, Martin

    2015-01-01

    Hydration water is the natural matrix of biological macromolecules and is essential for their activity in cells. The coupling between water and protein dynamics has been intensively studied, yet it remains controversial. Here we combine protein perdeuteration, neutron scattering and molecular dynamics simulations to explore the nature of hydration water motions at temperatures between 200 and 300?K, across the so-called protein dynamical transition, in the intrinsically disordered human protein tau and the globular maltose binding protein. Quasi-elastic broadening is fitted with a model of translating, rotating and immobile water molecules. In both experiment and simulation, the translational component markedly increases at the protein dynamical transition (around 240?K), regardless of whether the protein is intrinsically disordered or folded. Thus, we generalize the notion that the translational diffusion of water molecules on a protein surface promotes the large-amplitude motions of proteins that are required for their biological activity. PMID:25774711

  14. On switching H? controllers for nuclear steam generator water level: A multiple parameter-dependent Lyapunov functions approach

    International Nuclear Information System (INIS)

    Poor control of the steam generator (SG) water level in the secondary circuit of a nuclear power plant can lead to frequent reactor shutdowns. From the viewpoint of economic operation, it is critical to keep the water level of SG in well control. This paper presents a new framework for addressing this problem based on switching control to linear parameter varying (LPV) systems. A family of LPV controllers are designed, and each of them is suitable for a specific operating range. Under the admissible switching logic, the closed-loop system remains stable and achieves prescribed H? performance in the entire operating range. The approach is based on multiple parameter-dependent Lyapunov functions, which is less conservative than the employment of a single Lyapunov function. The switching LPV control scheme is then applied to the level control problem

  15. Amine functionalized radiation-induced grafted water hyacinth fibers for Pb2+, Cu2+ and Cr3+ uptake

    International Nuclear Information System (INIS)

    An amine group containing fibrous adsorbent was prepared by reaction of grafted water hyacinth fibers with ethylenediamine. Glycidyl methacrylate (GMA) was grafted onto water hyacinth fibers using gamma radiation induced graft polymerization through simultaneous grafting technique and this was used as base material for producing the amine type adsorbents. The conversion of the epoxy group from GMA into amine group was investigated. The concentration of ethylenediamine solution that gave the highest amine functional group density was 50% by volume in 2-propanol. The amine functionalized water hyacinth fibers were characterized using Attenuated Total Reflectance-Fourier Transformed Infrared Spectroscopy (ATR-FTIR), Thermogravimetric Analysis (TGA), and Energy Dispersive X-ray Spectroscopy (EDX). Information derived from these analyses confirms the successful conversion of the epoxy group. The amine-type adsorbent was evaluated for its uptake of Pb2+, Cu2+ and Cr3+ from aqueous solutions. The initial concentration of the metal ions and pH of the solutions were found to influence the amount of metal ions adsorbed by the amine-type adsorbent. The kinetics of adsorption was observed to follow Lagergren's first order equation. Results of ion sorption studies indicate that gamma radiation-induced grafting and subsequent chemical modification improved the ion sorption behaviour of water hyacinth fibers. - Highlights: • RIGP and amination imparted higher ion sorption capacity to water hyacinth fibers. • The epoxy group of grafted glycidyl methacrylate was reacted with ethylenediamine. • TGA, ATR-FTIR and EDX analysis confirmed successful amine functionalization. • The amine type fibrous adsorbent has higher affinity for Cu2+ and Pb2+ than Cr3+

  16. Displacive phase transformation in vanadium - substituted lanthanum niobate

    International Nuclear Information System (INIS)

    The displacive transformations in complex oxides of the type LaNb/sub 1-x/V/sub x/O4 has been studied by x-ray diffraction and Raman scattering for 0 ? x 6) to the monoclinic low-temperature structure (C/sub 2h/6) is higher than first order and that the transformation temperature T/sub c/ is depressed significantly by V substitution. Raman scattering results show that the force constant between the nearest (Nb, V)O4 tetrahedral units behave uniquely compared to others. It softens at T/sub c/ as a function of composition and it also softens as a function of temperature as T/sub c/ is approached from above. 10 references, 2 figures, 2 tables

  17. Optimization of Membership Functions for the Fuzzy Controllers of the Water Tank and Inverted Pendulum with Differents PSO Variants

    Directory of Open Access Journals (Sweden)

    Patricia Melin

    2013-11-01

    Full Text Available In this paper the Particle Swarm Optimization metaheuristic and two of its variants (inertia weight and constriction coefficient are used as an optimization strategy for the design of optimal membership functions of fuzzy control systems for the water tank and inverted pendulum benchmark problems. Each variant has its own advantages in the algorithm, allowing the exploration and exploitation in different ways and this allows finding the optimal solution in a better way.

  18. Optimization of Membership Functions for the Fuzzy Controllers of the Water Tank and Inverted Pendulum with Differents PSO Variants

    OpenAIRE

    Patricia Melin; Fevrier Valdez; Oscar Castillo; Resffa Fierro

    2013-01-01

    In this paper the Particle Swarm Optimization metaheuristic and two of its variants (inertia weight and constriction coefficient) are used as an optimization strategy for the design of optimal membership functions of fuzzy control systems for the water tank and inverted pendulum benchmark problems. Each variant has its own advantages in the algorithm, allowing the exploration and exploitation in different ways and this allows finding the optimal solution in a better way.

  19. Improvement of Hydraulic and Water Quality Renovation Functions by Intermittent Aeration of Soil Treatment Areas in Onsite Wastewater Treatment Systems

    OpenAIRE

    David V. Kalen; Josef H. Görres; Erika L. Patenaude; David A. Potts; George W. Loomis; Amador, José A.

    2010-01-01

    We tested intermittent aeration of the soil treatment area (STA) of onsite wastewater treatment systems (OWTS) for its ability to restore and maintain STA hydraulic flow and improve the water quality functions of conventional OWTS. Evaluation was conducted on hydraulically-failed conventional OWTS at three state-owned medical group homes in Washington County, RI, USA. Testing was conducted in two phases, with Phase I (before intermittent soil aeration (ISA)) comprising the first 6 months of t...

  20. Crack border stress and displacement equations revisited

    Science.gov (United States)

    Eftis, J.; Subramonian, N.; Liebowitz, H.

    1977-01-01

    It is more or less accepted in fracture mechanics that the elastic stress and displacements very near to the tip of a plane line crack can be approximated with sufficient accuracy, for all geometries and outer boundary loading conditions, by a one-parameter representation, i.e., strictly in terms of the stress intensity factors KI and/or KII. It is shown here that this presumption which appears to be reasonable on face value, quantitatively speaking, is nevertheless unacceptable as a general proposition. The reason lies with the quite arbitrary practice of omitting the second term of the series representation for the stresses, a contribution which is independent of distance from the crack tip. It is not difficult to show by way of specific examples how such omission can lead to error of serious qualitative nature in the prediction of stress and displacement related quantities of interest.

  1. Selfhood and Exile : Displacement, Worldliness, Trust

    DEFF Research Database (Denmark)

    Christensen, Gry Ardal

    2010-01-01

    Victims of traumatic events such as torture or life threatening assault often turn to a specific set of metaphors when trying to explain what it is like to be in the world afterwards. Spatial descriptions such as displacement, exile, homelessness and alienation occur repeatedly as significant terms for how living now differs from what it was like before. These spatial metaphors regularly occur in such first-person narratives along with descriptions of what can be called disturbances of the self: it seems that the feeling of being a self, of being this someone, suffers with such displacement. The purpose of this article is to investigate the relationship between spatiality and selfhood by way of how it feels when it is disrupted, or, in other words, to make sense of the claim raised by trauma survivors that they are exiled and that their selves are shattered

  2. MYTHIC DISPLACEMENT IN NIGERIAN NARRATIVES: AN INTRODUCTION

    Scientific Electronic Library Online (English)

    Ignatius, Chukwumah.

    2013-12-01

    Full Text Available Five decades of resorting to humanistic critical procedures have bequeathed to the Nigerian critical practice the legacy of examining and discovering in Nigerian and African narratives the historical and social concepts of the time and times they are presumed to posit. These concepts include colonia [...] lism, corruption, war, political instability, and culture conflict. These procedures are undertaken without due regard to seeing the whole of the literary tradition as a stream out of which narratives emerge. This article, therefore, by way of introduction, seeks to retrieve Nigerian narratives from "every author" and humanistic critical approach by placing them in a realm where a holistic method such as Frye's could be applied. Here, the traverses of the structure of mythical imagery such as the mythos of crime and punishment as embodied in these narratives and how this structure was displaced/shrouded from Frye's first mimetic mode to the last, via the concept of mythic displacement, will be analysed.

  3. Planar Displacement Detection with Point Feature Matching

    Directory of Open Access Journals (Sweden)

    Chen Feng-Dong

    2009-01-01

    Full Text Available A novel planar displacement detection method is implemented using Scale Invariant Feature Transform (SIFT point feature matching on a calibrated optical grating-vision measuring platform. SIFT is a method for extracting and describing image key-points, which are robustly invariant to scale, rotation and translation as well as robust to illumination changes and limited changes of viewpoint. The platform is moved along its x axis step by step and a series of images are captured with corresponding grating sensor values. SIFT feature points are extracted and matched between the successive images through a K-Dimension Tree (KD-Tree based feature matching algorithm to detect the displacement of each step. The detected values are compared with the corresponding grating sensor values. Experimental results prove that the accuracy of the method is less than 10 ?m in this environment.

  4. Density functional theory study of oxygen and water adsorption on SrTiO{sub 3}(001)

    Energy Technology Data Exchange (ETDEWEB)

    Guhl, Hannes

    2010-12-03

    Strontium titanate is an extensively studied material with a wide range of application, for instance in photo-catalysis and most importantly, it is used as a substrate in growth of functional oxides. The surface chemistry is crucial and hence understanding the surface structure on atomic scale is essential for gaining insight into the fundamental processes in the aforementioned applications. Moreover, there exist a lot of evidence that this surface chemistry might be controlled to considerably by extrinsic species, such as residual hydrogen and water. Investigating the properties of water and oxygen on the strontium titanate surface is certainly a natural starting point for a theoretical study based on density functional theory, because these species are practically present on the surface on a wide range of experimental conditions and they are computationally feasible. For the oxygen and water adsorption the binding energy is controlled by long-range surface relaxations leading to an effective repulsion of the adsorbed specimen. The isolated oxygen ad-atom forms a covalently bonded ''quasi-peroxide anion'' in combination with a lattice oxygen atom. Contrariwise, in all investigated configurations containing water molecules and hydroxyl groups, the respective oxygen atoms assumed positions close to the oxygen sites of the continued perovskite lattice of the substrate. Most remarkably, on the strontium oxide termination, the water molecules adsorbs and dissociates effortlessly leading to the formation of a pair of hydroxyl groups. For the titanium dioxide termination, a coverage dependent adsorption mode is observed. Densely packings stabilize water molecules, whereas at lower coverage and finite temperatures the formation of hydroxyl groups is found. The energetics responsible for this behavior is consistent with recent experiments by Iwahori and coworkers. (orig.)

  5. Density functional theory study of oxygen and water adsorption on SrTiO3(001)

    International Nuclear Information System (INIS)

    Strontium titanate is an extensively studied material with a wide range of application, for instance in photo-catalysis and most importantly, it is used as a substrate in growth of functional oxides. The surface chemistry is crucial and hence understanding the surface structure on atomic scale is essential for gaining insight into the fundamental processes in the aforementioned applications. Moreover, there exist a lot of evidence that this surface chemistry might be controlled to considerably by extrinsic species, such as residual hydrogen and water. Investigating the properties of water and oxygen on the strontium titanate surface is certainly a natural starting point for a theoretical study based on density functional theory, because these species are practically present on the surface on a wide range of experimental conditions and they are computationally feasible. For the oxygen and water adsorption the binding energy is controlled by long-range surface relaxations leading to an effective repulsion of the adsorbed specimen. The isolated oxygen ad-atom forms a covalently bonded ''quasi-peroxide anion'' in combination with a lattice oxygen atom. Contrariwise, in all investigated configurations containing water molecules and hydroxyl groups, the respective oxygen atoms assumed positions close to the oxygen sites of the continued perovskite lattice of the substrate. Most remarkably, on the strontium oxide termination, the water molecules adsorbs and dissociates effortlessly leading to the formation of a pair of hydroxyl groups. For the titanium dioxide termination, a coverage dependent adsorption mode is observed. Densely packings stabilize water molecules, whereas at lower coverage and finite temperatures the formation of hydroxyl groups is found. The energetics responsible for this behavior is consistent with recent experiments by Iwahori and coworkers. (orig.)

  6. Amine functionalized radiation-induced grafted water hyacinth fibers for Pb2+, Cu2+ and Cr3+ uptake

    Science.gov (United States)

    Madrid, Jordan F.; Nuesca, Guillermo M.; Abad, Lucille V.

    2014-04-01

    An amine group containing fibrous adsorbent was prepared by reaction of grafted water hyacinth fibers with ethylenediamine. Glycidyl methacrylate (GMA) was grafted onto water hyacinth fibers using gamma radiation induced graft polymerization through simultaneous grafting technique and this was used as base material for producing the amine type adsorbents. The conversion of the epoxy group from GMA into amine group was investigated. The concentration of ethylenediamine solution that gave the highest amine functional group density was 50% by volume in 2-propanol. The amine functionalized water hyacinth fibers were characterized using Attenuated Total Reflectance-Fourier Transformed Infrared Spectroscopy (ATR-FTIR), Thermogravimetric Analysis (TGA), and Energy Dispersive X-ray Spectroscopy (EDX). Information derived from these analyses confirms the successful conversion of the epoxy group. The amine-type adsorbent was evaluated for its uptake of Pb2+, Cu2+ and Cr3+ from aqueous solutions. The initial concentration of the metal ions and pH of the solutions were found to influence the amount of metal ions adsorbed by the amine-type adsorbent. The kinetics of adsorption was observed to follow Lagergren's first order equation. Results of ion sorption studies indicate that gamma radiation-induced grafting and subsequent chemical modification improved the ion sorption behaviour of water hyacinth fibers.

  7. Light-induced water oxidation at silicon electrodes functionalized with a cobalt oxygen-evolving catalyst

    OpenAIRE

    Pijpers, Joep J. H.; Winkler, Mark T.; Surendranath, Yogesh; Buonassisi, Tonio; Nocera, Daniel G.

    2011-01-01

    Integrating a silicon solar cell with a recently developed cobalt-based water-splitting catalyst (Co-Pi) yields a robust, monolithic, photo-assisted anode for the solar fuels process of water splitting to O2 at neutral pH. Deposition of the Co-Pi catalyst on the Indium Tin Oxide (ITO)-passivated p-side of a np-Si junction enables the majority of the voltage generated by the solar cell to be utilized for driving the water-splitting reaction. Operation under neutral pH conditions fosters enhanc...

  8. Hierarchic Theory of Condensed Matter Role of water in protein dynamics, function and cancer emergency

    CERN Document Server

    Kaivarainen, A

    2000-01-01

    1. Role of inter-domain water clusters in large-scale dynamics of proteins; 2. Description of large-scale dynamics of proteins based on generalized Stokes-Einstein and Eyring-Polany equation; 3. Dynamic model of protein-ligand complexes formation; 4. The life-time of quasiparticles and frequencies of their excitation; 5. Mesoscopic mechanism of enzyme catalysis; 6. The mechanism of ATP hydrolysis energy utilization in muscle contraction and protein polymerization; 7. Water activity as a regulative factor in the intra- and inter-cell processes; 8. Water and cancer.

  9. Effect of varying water intake on renal function in healthy preterm babies.

    OpenAIRE

    Coulthard, M. G.; Hey, E. N.

    1985-01-01

    Renal control of water and electrolyte homeostasis was studied in 10 healthy babies (gestation 29 to 34 weeks; birthweight 1.19 to 2.19 kg) while water intake was varied. Glomerular filtration rate and urine flow were estimated daily from spot plasma and urine samples for six days using a constant inulin infusion, and simultaneous sodium, potassium, osmolar, and free water clearances were calculated. The infusion was started at an average age of 14 hours. Each baby received a total fluid inta...

  10. Social capital in involuntary displacement and resettlement

    OpenAIRE

    Navarra, M.; Niehof, A.; Vaart, W.

    2013-01-01

    Social capital is often seen as a substitute for lack of other types of capital among poor people. Because of the recognized applicability of the social capital concept and its correlation with the different dimensions of poverty, it has been used in evaluating the adaptation and integration of involuntarily displaced individuals into their new environment. This paper presents insights based on a review of the findings of studies that looked into the role of social capital in conflict- a...

  11. Removal of mercury (II) by dithiocarbamate surface functionalized magnetite particles: application to synthetic and natural spiked waters.

    Science.gov (United States)

    Figueira, P; Lopes, C B; Daniel-da-Silva, A L; Pereira, E; Duarte, A C; Trindade, T

    2011-11-01

    In order to take advantage of the high affinity between mercury and sulphur, magnetite (Fe(3)O(4)) particles functionalized with dithiocarbamate groups (CS(2)(-)), were synthesized to be used as a new type of sorbent to remove Hg (II) from synthetic and natural spiked waters. The effectiveness of this type of sorbent was studied, and its potential as cleanup agent for contaminated waters was assessed. Batch stirred tank experiments were carried out by contacting a volume of solution with known amounts of functionalized Fe(3)O(4) particles, in order to study the effect of sorbent dose, salinity, and the kinetics and the equilibrium of this unit operation. A complete Hg (II) removal (ca. 99.8%) was attained with 6 mg/L of magnetic particles for an initial metal concentration of 50 ?g/L. It was confirmed that highly complex matrices, such as seawater (ca. 99%) and river water (ca. 97%), do not affect the removal capacity of the functionalized magnetic particles. Concerning isotherms, no significant differences were observed between two- and three-parameter models (P = 0.05%); however, Sips isotherm provided the lowest values of SS and S(x/y), predicting a maximum sorption capacity of 206 mg/g, in the range of experimental conditions under study. The solid loadings measured in this essay surmount the majority of the values found in literature for other type of sorbents. PMID:21924455

  12. Comparing Teaching Approaches About Maxwell's Displacement Current

    Science.gov (United States)

    Karam, Ricardo; Coimbra, Debora; Pietrocola, Maurício

    2014-08-01

    Due to its fundamental role for the consolidation of Maxwell's equations, the displacement current is one of the most important topics of any introductory course on electromagnetism. Moreover, this episode is widely used by historians and philosophers of science as a case study to investigate several issues (e.g. the theory-experiment relationship). Despite the consensus among physics educators concerning the relevance of the topic, there are many possible ways to interpret and justify the need for the displacement current term. With the goal of understanding the didactical transposition of this topic more deeply, we investigate three of its domains: (1) The historical development of Maxwell's reasoning; (2) Different approaches to justify the term insertion in physics textbooks; and (3) Four lectures devoted to introduce the topic in undergraduate level given by four different professors. By reflecting on the differences between these three domains, significant evidence for the knowledge transformation caused by the didactization of this episode is provided. The main purpose of this comparative analysis is to assist physics educators in developing an epistemological surveillance regarding the teaching and learning of the displacement current.

  13. Displacing Lagrangian toric fibers via probes

    CERN Document Server

    McDuff, Dusa

    2009-01-01

    This note studies the geometric structure of monotone moment polytopes (the duals of smooth Fano polytopes) using probes. The latter are line segments that enter the polytope at an interior point of a facet and whose direction is integrally transverse to this facet. A point inside the polytope is displaceable by a probe if it lies less than half way along it. Using a construction due to Fukaya--Oh--Ohta--Ono, we show that every rational polytope has a central point that is not displaceable by probes. In the monotone (or more generally, the reflexive) case, this central point is its unique interior integral point. In the monotone case, every other point is displaceable by probes if and only if the polytope satisfies the star Ewald condition. (This is a strong version of the Ewald conjecture concerning the integral symmetric points in the polytope.) Further, in dimensions up to and including three every monotone polytope is star Ewald. These results are closely related to the Fukaya--Oh--Ohta--Ono calculations ...

  14. A reference material for dynamic displacement calibration

    Directory of Open Access Journals (Sweden)

    Whelan M.

    2010-06-01

    Full Text Available Calibration of displacement and strain measurement systems is an essential step in providing traceability and confidence in stress and strain distributions obtained from experiment and used to validate simulations employed in engineering design. Reference materials provide a simple, well-defined distribution of the measured quantity that can be traced to an international standard and can be used to assess the uncertainty associated with the measurement system. Previous work has established a reference material and procedure for calibrating optical systems for measuring static, in-plane strain distributions and also demonstrated its use. A new effort is in progress to extend this work to the measurement of three-dimensional displacement distributions induced by cyclic and dynamic loading, including transients and large-scale deformation. The first step in this effort has been to define both the essential and desirable attributes of a reference material for calibrating systems capable of measurements of dynamic displacement and strain. An international consortium of research laboratories, system designers, manufacturers and end-users has identified a list of attributes and members of the experimental mechanics community have been asked to weight the importance of these attributes. The attributes are being utilised to evaluate candidate designs for the reference material which have been generated through a series of brain-storming sessions within the consortium.

  15. Interferometric nanocomparator for calibrating precision displacement sensors

    Science.gov (United States)

    Cizek, Martin; Buchta, Zdenek; Mikel, Bretislav; Lazar, Josef; Cip, Ondrej

    2010-08-01

    Presented work deals with the description of a novel interferometric nanocomparator intended for calibrating displacement sensors with nanometer resolution used in precision engineering. The nanocomparator is based on a 633 nm laser homodyne interferometer with 2-pass measuring arm. Digital signal filtering increases the SNR and allows achieving sub-nanometer resolution of interferometric measurements. High dynamic range of the measuring mirror displacement is achieved using a two-stage positioning system formed of a linear guide way and piezoelectric actuators. A linear guide way is used for positioning over a 100 mm range with 50 nm resolution. Piezoelectric actuators linked in a closed loop locked to the interferometer value are used for fine positioning with better than 1 nm resolution over a 5 um range. Two alternative versions of the mechanical design of the coarse positioning stage were tested and compared: a design utilizing a linear guide way with ball carrier bearings and a positioning system formed of a parallelogram frame with flexible junctions. Wearing out of linear guide ways may cause angular deviations of the mirror from the ideally perpendicular position to the laser beam. Active stabilization of the mirror using piezoelectric actuators linked to a 4-quadrant light detector was developed to eliminate these deviations and other angular errors. A set of experimental calibrations of inductive and incremental rule precision displacement sensors was conducted.

  16. International Monetary Fund and aid displacement.

    Science.gov (United States)

    Stuckler, David; Basu, Sanjay; McKee, Martin

    2011-01-01

    Several recent papers find evidence that global health aid is being diverted to reserves, education, military, or other sectors, and is displacing government spending. This is suggested to occur because ministers of finance have competing, possibly corrupt, priorities and deprive the health sector of resources. Studies have found that development assistance for health routed to governments has a negative impact on health spending and that similar assistance routed to private nongovernmental organizations has a positive impact. An alternative hypothesis is that World Bank and IMF macro-economic policies, which specifically advise governments to divert aid to reserves to cope with aid volatility and keep government spending low, could be causing the displacement of health aid. This article evaluates whether aid displacement was greater when countries undertook a new borrowing program from the IMF between 1996 and 2006. As found in existing studies, for each $1 of development assistance for health, about $0.37 is added to the health system. However, evaluating IMF-borrowing versus non-IMF-borrowing countries reveals that non-borrowers add about $0.45 whereas borrowers add less than $0.01 to the health system. On average, health system spending grew at about half the speed when countries were exposed to the IMF than when they were not. It is important to take account of the political economy of global health finance when interpreting data on financial flows. PMID:21319721

  17. Vertical displacement and position control in tokamaks

    International Nuclear Information System (INIS)

    Free-boundary nearly rigid displacements are considered in a plasma confined by a magnetic field consisting of one part generated by the plasma current density, and one part being due to steady currents in fixed external conductors. An induced surface current effect and a related force on the plasma arise when the externally applied field is inhomogeneous in the direction of displacement. This additional force has not been taken into account in conventional MHD theory. In the particular case of tokamaks , the induced surface current effect has two impacts on vertical nearly rigid displacements. First, there arises an additional restoring force and a positive contribution to the change in potential energy when the externally applied field is inhomogeneous in the vertical direction. A special design of poloidal field coils can thus provide new means for vertical position control in tokamaks, also in the case of strongly elongated cross-sections. Second, an earlier simplified model, in which the plasma is represented by a line current, has to be modified since the plasma is a highly conducting body of finite size. 4 refs

  18. Maximum Entropy Method for Operational Loads Feedback Using Concrete Dam Displacement

    Directory of Open Access Journals (Sweden)

    Jingmei Zhang

    2015-05-01

    Full Text Available Safety control of concrete dams is required due to the potential great loss of life and property in case of dam failure. The purpose of this paper is to feed back the operational control loads for concrete dam displacement using the maximum entropy method. The proposed method is not aimed at a judgement about the safety conditions of the dam. When a strong trend-line effect is evident, the method should be carefully applied. In these cases, the hydrostatic and temperature effects are added to the irreversible displacements, thus maximum operational loads should be accordingly reduced. The probability density function for the extreme load effect component of dam displacement can be selected by employing the principle of maximum entropy, which is effective to construct the least subjective probability density distribution merely given the moments information from the stated data. The critical load effect component in the warning criterion can be determined through the corresponding cumulative distribution function obtained by the maximum entropy method. Then the control loads feedback of concrete dam displacement is realized by the proposed warning criterion. The proposed method is applied to a concrete dam. A comparison of the results shows that the maximum entropy method can feed back rational control loads for the dam displacement. The control loads diagram obtained can be a straightforward and visual tool to the operation and management department of the concrete dam. The result from the proposed method is recommended to be used due to minimal subjectivity.

  19. Assessment of Regional Myocardial Displacement via Spectral Tissue Doppler Compared with Color Tissue Tracking

    Directory of Open Access Journals (Sweden)

    Zahra Ojaghi-Haghighi

    2008-12-01

    Full Text Available Background: The recent developments in tissue Doppler imaging (TDI now more than ever permit the quantification of the myocardial function. In the current systems, tissue tracking or displacement curves are generated from color tissue Doppler data through the instantaneous temporal integral of velocity-time curves. Methods: The purpose of the present study was to assess regional myocardial displacement via spectral TDI. Maximum myocardial velocities were extracted from spectral pulsed tissue Doppler images using a developed computer program and were integrated throughout the cardiac cycle. Spectral tissue Doppler echocardiography was performed to evaluate longitudinal and radial functions in 20 healthy men, and the calculated end-systolic displacements were subsequently compared with the displacements measured from the same areas via color tissue tracking. Results: According to the Bland-Altman analysis between spectral tissue tracking and color tissue tracking, the significant arithmetic mean was 7.34 mm with SD mean differences of ±2.24 mm in all of the evaluated segments. Despite significant differences (p<0.001, there was a good significant correlation between the two methods (r=0.79, p<0.001. Conclusion: A verification study showed that the proposed approach had the ability to assess regional myocardial displacement using spectral TDI, which can be used in a wider range of equipment than is currently possible.

  20. HIV and the internally displaced: Burundi in focus

    OpenAIRE

    Raquel Wexler

    2003-01-01

    "Special attention should also be given to the prevention of contagious and infectious diseases, including AIDS, among internally displaced persons." (Guiding Principles on InternalDisplacement, 19.3)

  1. HIV and the internally displaced: Burundi in focus

    Directory of Open Access Journals (Sweden)

    Raquel Wexler

    2003-01-01

    Full Text Available "Special attention should also be given to the prevention of contagious and infectious diseases, including AIDS, among internally displaced persons." (Guiding Principles on InternalDisplacement, 19.3

  2. 24 CFR 941.207 - Displacement, relocation, and acquisition.

    Science.gov (United States)

    2010-04-01

    ...including data indicating the race, ethnic, gender and disability status of displaced persons. (h) Definition of displaced person. (1) For purposes...be covered by this section. (i) Definition of initiation of negotiations. For...

  3. 24 CFR 886.338 - Displacement, relocation, and acquisition.

    Science.gov (United States)

    2010-04-01

    ...maintain data on the race, ethnic, gender, and handicap status of displaced persons. (g) Definition of displaced person. (1) For purposes...be covered by this section. (h) Definition of initiation of negotiations....

  4. 24 CFR 886.138 - Displacement, relocation, and acquisition.

    Science.gov (United States)

    2010-04-01

    ...maintain data on the race, ethnic, gender, and handicap status of displaced persons. (g) Definition of displaced person. (1) for purposes...be covered by this section. (h) Definition of initiation of negotiations....

  5. 24 CFR 882.810 - Displacement, relocation, and acquisition.

    Science.gov (United States)

    2010-04-01

    ...maintain data on the racial, ethnic, gender, and disability status of displaced persons. (g) Definition of displaced person. (1) For purposes...be covered by this section. (h) Definition of initiation of negotiations....

  6. 24 CFR 236.1001 - Displacement, relocation, and acquisition.

    Science.gov (United States)

    2010-04-01

    ...maintain data on the race, ethnic, gender, and disability status of displaced persons. (g) Definition of displaced person. (1) For purposes...be covered by this section. (h) Definition of initiation of negotiations....

  7. Functional colocalization of water channels and proton pumps in endosomes from kidney proximal tubule

    OpenAIRE

    1989-01-01

    The apical membrane of mammalian proximal tubule undergoes rapid membrane cycling by exocytosis and endocytosis. Osmotic water and ATP- driven proton transport were measured in endocytic vesicles from rabbit and rat proximal tubule apical membrane labeled in vivo with the fluid phase marker fluorescein-dextran. Osmotic water permeability (Pf) was determined from the time course of fluorescein-dextran fluorescence after exposure of endosomes to an inward osmotic gradient in a stopped- flow app...

  8. Application of renormalized coupled-cluster methods to potential function of water

    OpenAIRE

    Piecuch, Piotr; Wloch, Marta; António J. C. Varandas

    2008-01-01

    Abstract The goal of this paper is to examine the performance of the conventional and renormalized single-reference coupled-cluster (CC) methods in calculations of the potential energy surface of the water molecule. A comparison with the results of the internally contracted multi-reference configuration interaction calculations including the quasi-degenerate Davidson correction (MRCI(Q)) and the spectroscopically accurate potential energy surface of water resulting from the use of the energy...

  9. Use of stream response functions to determine impacts of replacing surface-water use with groundwater withdrawals

    Science.gov (United States)

    Pruneda, Erik B.; Barber, Michael E.; Allen, Diana M.; Wu, Joan Q.

    2010-08-01

    A regional-scale numerical groundwater model is used to study the impacts of replacing surface-water use with groundwater wells to improve low-flow stream conditions for endangered species within the Bertrand and Fishtrap watersheds, southern British Columbia, Canada and Washington, USA. Stream response functions ranging from 0 to 1.0 were calculated for individual wells placed within a steady-state groundwater flow model at varying distances from the streams to determine the impact that these replacement wells, operating under sustained pumping rates, would have on summer instream flows. Lower response ratios indicate groundwater pumping will have less of an impact on streamflow than taking an equivalent amount of water directly from a surface-water source. Results show that replacing surface-water use with groundwater withdrawals may be a viable alternative for increasing summer streamflows. Assuming combined response factors should be ?0.5 for irrigators to undergo the expense of installing new wells, ~57% of the land area within 0.8 km of Bertrand Creek would be suitable for replacement wells. Similarly, 70% of the land area within 0.8 km of Fishtrap Creek was found to be appropriate. A visual analysis tool was developed using STELLA to allow stakeholders to quickly evaluate the impact associated with moving their water right.

  10. Climate change and water use partitioning by different plant functional groups in a grassland on the Tibetan Plateau.

    Science.gov (United States)

    Hu, Jia; Hopping, Kelly A; Bump, Joseph K; Kang, Sichang; Klein, Julia A

    2013-01-01

    The Tibetan Plateau (TP) is predicted to experience increases in air temperature, increases in snowfall, and decreases in monsoon rains; however, there is currently a paucity of data that examine the ecological responses to such climate changes. In this study, we examined the effects of increased air temperature and snowfall on: 1) water use partitioning by different plant functional groups, and 2) ecosystem CO2 fluxes throughout the growing season. At the individual plant scale, we used stable hydrogen isotopes (?D) to partition water use between shallow- and deep-rooted species. Prior to the arrival of summer precipitation (typically mid-July), snowmelt was the main water source in the soils. During this time, shallow and deep-rooted species partitioned water use by accessing water from shallow and deep soils, respectively. However, once the monsoon rains arrived, all plants used rainwater from the upper soils as the main water source. Snow addition did not result in increased snowmelt use throughout the growing season; instead, snowmelt water was pushed down into deeper soils when the rains arrived. At the larger plot scale, CO2 flux measurements demonstrated that rain was the main driver for net ecosystem productivity (NEP). NEP rates were low during June and July and reached a maximum during the monsoon season in August. Warming decreased NEP through a reduction in gross primary productivity (GPP), and snow additions did not mitigate the negative effects of warming by increasing NEP or GPP. Both the isotope and CO2 flux results suggest that rain drives productivity in the Nam Tso region on the TP. This also suggests that the effects of warming-induced drought on the TP may not be mitigated by increased snowfall. Further decreases in summer monsoon rains may affect ecosystem productivity, with large implications for livestock-based livelihoods. PMID:24069425

  11. Simulation of viscous instabilities in miscible and immiscible displacement

    OpenAIRE

    Gilje, Eli

    2008-01-01

    This study includes modeling of viscous instabilities at both miscible and immiscible displacement. Oil recovery of heavy oil leads to unstable displacement for adverse mobility ratio for both miscible and immiscible displacement. Simulation studies of viscous fingering in miscible and immiscible displacements were performed in order to history match 2D slab laboratory experiments performed at CIPR, Centre for Integrated Petroleum Research. History matching of a polymer flood experiment i...

  12. How destructive is creative destruction? The costs of worker displacement

    OpenAIRE

    Huttunen, Kristiina; Møen, Jarle; Salvanes, Kjell Gunnar

    2006-01-01

    We analyze the long-term effects of worker displacement using a large administrative matched employer–employee database spanning throughout the entire Norwegian economy. Our focus is on prime-age male manufacturing sector workers displaced due to plant closure or significant downsizing of the plant. The data follows these workers within the Norwegian economy up to seven years after displacement. We demonstrate that displacement significantly increases the probability of exiting the labor fo...

  13. Effect of water chemistry on the oxide film on Alloy 690 during simulated hot functional testing of a pressurised water reactor

    International Nuclear Information System (INIS)

    Highlights: ? Influence of hot functional test chemistry on Alloy 690 oxidation studied by EIS/XPS. ? Increase in LiOH concentration leads to a higher dissolution rate of the oxide. ? Higher boric acid content leads to more efficient passivation of the surface. ? Oxidation parameters estimated by comparison of results to the Mixed-Conduction Model. - Abstract: Electrochemical impedance spectroscopic measurements to follow the oxidation of Alloy 690 in high-temperature water environments simulating hot functional test (HFT) chemistries are presented and discussed. The thickness and in-depth composition of the formed oxides is estimated by X-ray photoelectron spectroscopy. Kinetic and transport parameters of the oxidation process are estimated by quantitative comparison of the results with the mixed-conduction model for oxide films. Based on the influence of LiOH and H3BO3 concentrations on the parameter values, conclusions for the relationship between HFT water chemistry and the electrical and electrochemical properties of the passive layer on reactor coolant circuit surfaces are drawn.

  14. Isolation of monoclonal antibody charge variants by displacement chromatography.

    Science.gov (United States)

    McAtee, C Patrick; Hornbuckle, Jacob

    2012-08-01

    This unit discusses the important parameters in designing and optimizing a separation of monoclonal antibody (mAb) charge variants from process streams by ion-exchange displacement chromatography, including sample preparation and selection of matrix, column, and appropriate buffer. A protocol is provided for determination of optimal column binding and displacement conditions, including cleaning and regeneration of the displacement columns. PMID:22851499

  15. Year of displaced people’s rights in Colombia

    OpenAIRE

    Marco Alberto Romero

    2007-01-01

    A Campaign for the Rights of Displaced People in Colombia, launched in 2007 by UNHCR, Colombian NGO CODHES and the Catholic Church, has tried to raise awareness in Colombia and the international community about the severity of the country’s displacement crisis and its failure to guarantee the rights of displaced people.

  16. Comments on “Electrical conductivity of wadsleyite as a function of temperature and water content” by Manthilake et al.

    Science.gov (United States)

    Karato, Shun-ichiro; Dai, Lidong

    2009-05-01

    In a recent paper, Manthilake et al. [Manthilake, M.A.G.M., et al. Electrical conductivity of wadsleyite as a function of temperature and water content. Physics of the Earth and Planetary Interiors, in press] presented the results of experimental study on the electrical conductivity of wadsleyite and concluded that the influence of water is small at transition zone temperatures and that a high concentration of water (hydrogen) cannot explain the observed conductivity in the transition zone as oppose to the conclusion originally obtained by Huang et al. [Huang, X., Xu, Y., Karato, S., 2005. Water content of the mantle transition zone from the electrical conductivity of wadsleyite and ringwoodite. Nature 434, 746-749) from a similar experimental study. In this note, we discuss the causes of discrepancies between the results by two groups and show that almost all the differences are due to the experimental artifacts in the studies by Manthilake et al. and Yoshino et al. [Manthilake, M.A.G.M., et al. Electrical conductivity of wadsleyite as a function of temperature and water content. Physics of the Earth and Planetary Interiors, in press; Yoshino, T., Manthilake, G., Matsuzaki, T., Katsura, T., 2008a. Dry mantle transition zone inferred from the conductivity of wadsleyite and ringwoodite. Nature 451, 326-329] namely (i) the use of inappropriate method of determining electrical conductivity and (ii) the use of the data from a sample of wadsleyite with a substantial amount of water as a "dry" conductivity. A comparison of electrical conductivity of truly "dry" wadsleyite and olivine shows that the conductivity is similar at the same pressure and temperature. We also show that the use of one frequency method results in systematic errors in the conductivity measurements that explains the discrepancies in the results by two sets of studies. When an appropriate method for determining electrical conductivity (i.e., the impedance spectroscopy) is used and when the results of truly dry sample are used for the background dry conductivity, we find that the influence of water (hydrogen) is large enough to explain a majority of variation of electrical conductivity by the regional variation in water content.

  17. Experimental and simulated displacement of oil in sand berea cores using aqueous solutions

    International Nuclear Information System (INIS)

    The development of a mathematical algorithm to simulate the displacement of a resident fluid using a displacing one in a saturated anisotropic porous media is shown in this work. The algorithm was included in the simulator developed by the present authors in previous works to represent the anisotropic distribution of the porous media properties and the fluid injection [Ramirez A et al. Mathematical simulation of oil reservoir properties. Chaos, solitons and Fractals 2008;38:778-88, Ramirez A et al. Simulation of uncompressible fluid flow through a porous media. Chaos, Solitons and Fractals 2009;39:1753-63] in a nested loop to analyze the participant nodes in the transport process and calculate the volumes of the resident and new fluids. The new routine developed takes in count the mobility of both fluids. Additionally experimental fluid displacement tests were done using heavy oil from Mexican reservoirs as a resident fluid in sand berea cores. The injection of new fluids in natural oil reservoirs is a part of the Enhanced oil recovery (EOR) methods used to improve the oil displacement and increase production after the primary stage of the oil recovery has been finished. Water is an available and economical resource to be used as a displacing fluid due to many of the producers (off-shores) of the oil industries are placed in the sea near the coast.

  18. Hemimicelle capped functionalized carbon nanotubes-based nanosized solid-phase extraction of arsenic from environmental water samples

    International Nuclear Information System (INIS)

    The end functionalization of CNTs can introduce oxygen-containing negatively functional groups such as -COOH, -OH, or -C=O on their surface site. If cationic surfactant such as cetyltrimethylammonium chloride (CTAC) was added to the functionalized CNTs, then interactions such as hydrophobic and ionic may lead to formation of hemimicelle/admicelle aggregates on the CNTs, a new kind of adsorbents, namely, the hemimicelle capped CMMWCNTs, is obtained. The application of the hemimicelle capped carbon nanotubes-based nanosized solid-phase extraction (SPE) adsorbents in environmental analysis is reported for the first time using arsenic as model target. The effect of adsorption and desorption conditions for arsenic including the amount of surfactant, initial pH of sample solution, the ultrasonic time of sample solution, the amount of electrolyte, flow rate, eluent and its amount were investigated and optimized prior to its determination by atomic fluorescence spectrophotometry (AFS). Arsenic can be quantitatively retained on the hemimicelle capped CMMWCNTs at pH 5-6 from sample volume up to 500 mL and then eluted completely with 2 mol L-1 HNO3 in the presence of 10 mg L-1 CTAC. The method detection limit for arsenic determination with AFS detection was 2 ng L-1, and the relative standard deviation (RSD, n = 11) was 5.3% at the 0.5 ?g L-1 level. The recoveries of arsenic in the spiked environmental water samples ranged piked environmental water samples ranged from 94% to 104.29% with 500 mL of water sample. The proposed method has been applied successfully to the analysis of arsenic in aqueous environmental samples, which demonstrates the hemimicelle capped CMMWCNTs can be an excellent SPE adsorbents for arsenic pretreatment and enrichment from real water samples

  19. Functional characterization of water transport and cellular localization of three aquaporin paralogs in the salmonid intestine

    DEFF Research Database (Denmark)

    Madsen, Steffen S; Olesen, Jesper H

    2011-01-01

    Intestinal water absorption is greatly enhanced in salmonids upon acclimation from freshwater (FW) to seawater (SW); however, the molecular mechanism for water transport is unknown. We conducted a pharmacological characterization of water absorption in the rainbow trout intestine along with an investigation of the distribution and cellular localization of three aquaporins (Aqp1aa, -1ab, and -8ab) in pyloric caeca, middle (M), and posterior (P) intestine of the Atlantic salmon. In vitro iso-osmotic water absorption (J(v)) was higher in SW than FW-trout and was inhibited by (mmol L(-1)): 0.1 KCN (41%), 0.1 ouabain (72%), and 0.1 bumetanide (82%) suggesting that active transport, Na(+), K(+)-ATPase and Na(+), K(+), 2Cl(-)-co-transport are involved in establishing the driving gradient for water transport. J(v) was also inhibited by 1?mmol?L(-1) HgCl(2), serosally (23% in M and 44% in P), mucosally (27% in M), or both (61% in M and 58% in P), suggesting involvement of both apical and basolateral aquaporins in water transport. The inhibition was antagonized by 5?mmol?L(-1) mercaptoethanol. By comparison, 10?mmol?L(-1) mucosal tetraethylammonium, an inhibitor of certain aquaporins, inhibited J(v) by 20%. In the presence of glucose, mucosal addition of phloridzin inhibited water transport by 20%, suggesting that water transport is partially linked to the Na(+)-glucose co-transporter. Using polyclonal antibodies against salmon Aqp1aa, -1ab, and -8ab, we detected Aqp1aa, and -1ab immunoreactivity in the brush border and sub-apical region of enterocytes in all intestinal segments. The Aqp8ab antibody showed a particularly strong immunoreaction in the brush border and sub-apical region of enterocytes throughout the intestine and also stained lateral membranes and peri-nuclear regions though at lower intensity. The present localization of three aquaporins in both apical and lateral membranes of salmonid enterocytes facilitates a model for transcellular water transport in the intestine of SW-acclimated salmonids.

  20. The displacement estimation error back-propagation (DEEP) method for a multiple structural displacement monitoring system

    International Nuclear Information System (INIS)

    Visually servoed paired structured light system (ViSP) has been found to be useful in estimating 6-DOF relative displacement. The system is composed of two screens facing each other, each with one or two lasers, a 2-DOF manipulator and a camera. The displacement between two sides is estimated by observing positions of the projected laser beams and rotation angles of the manipulators. To apply the system to massive structures, the whole area should be partitioned and each ViSP module is placed in each partition in a cascaded manner. The estimated displacement between adjoining ViSPs is combined with the next partition so that the entire movement of the structure can be estimated. The multiple ViSPs, however, have a major problem that the error is propagated through the partitions. Therefore, a displacement estimation error back-propagation (DEEP) method which uses Newton–Raphson or gradient descent formulation inspired by the error back-propagation algorithm is proposed. In this method, the estimated displacement from the ViSP is updated using the error back-propagated from a fixed position. To validate the performance of the proposed method, various simulations and experiments have been performed. The results show that the proposed method significantly reduces the propagation error throughout the multiple modules. (paper)

  1. Immersion freezing of water and aqueous ammonium sulfate droplets initiated by humic-like substances as a function of water activity

    Directory of Open Access Journals (Sweden)

    Y. J. Rigg

    2013-07-01

    Full Text Available Immersion freezing of water and aqueous (NH42SO4 droplets containing leonardite (LEO and Pahokee peat (PP serving as surrogates for humic-like substances (HULIS has been investigated. Organic aerosol containing HULIS are ubiquitous in the atmosphere; however, their potential for ice cloud formation is uncertain. Immersion freezing has been studied for temperatures as low as 215 K and solution water activity, aw, from 0.85 to 1.0. The freezing temperatures of water and aqueous solution droplets containing LEO and PP are 5–15 K warmer than homogeneous ice nucleation temperatures. Heterogeneous freezing temperatures can be represented by a horizontal shift of the ice melting curve as a function of solution aw by ?aw = 0.2703 and 0.2466, respectively. Corresponding hetrogeneous ice nucleation rate coefficients, Jhet, are (9.6 ± 2.5×104 and (5.4 ± 1.4×104 cm?2 s?1 for LEO and PP containing droplets, respectively, and remain constant along freezing curves characterized by ?aw. Consequently predictions of freezing temperatures and kinetics can be made without knowledge of the solute type when relative humidity and ice nuclei (IN surface areas are known. The acquired ice nucleation data are applied to evaluate different approaches to fit and reproduce experimentally derived frozen fractions. In addition, we apply a basic formulation of classical nucleation theory (?(T-model to calculate contact angles and frozen fractions. Contact angles calculated for each ice nucleus as a function of temperature, ?(T-model, reproduce exactly experimentally derived frozen fractions without involving free-fit parameters. However, assigning the IN a single contact angle for the entire population (single-? model is not suited to represent the frozen fractions. Application of ?-PDF, active sites, and deterministic model approaches to measured frozen fractions yield similar good representations. Furthermore, when using a single parameterization of ?-PDF or active sites distribution to fit all individual aw immersion freezing data simultaneously, frozen fraction curves are not reproduced. This implies that these fitting formulations cannot be applied to immersion freezing of aqueous solutions, and suggests that derived fit parameters do not represent independent particle properties. Thus, from fitting frozen fractions only, the underlying ice nucleation mechanism and nature of the ice nucleating sites cannot be inferred. In contrast to using fitted functions obtained to represent experimental conditions only, we suggest to use experimentally derived Jhet as a function of temperature and aw that can be applied to conditions outside of those probed in laboratory. This is because Jhet(T is independent of time and IN surface areas in contrast to the fit parameters obtained by representation of experimentally derived frozen fractions.

  2. Supersymmetry and coherent states for the displacement-operator-derived effective mass system

    Science.gov (United States)

    Vubangsi, M.; Tchoffo, M.; Fai, L. C.; Pis'mak, Yu. M.

    2015-01-01

    Applying the supersymmetric quantum mechanics approach, we derive shape-invariant trigonometric potentials for the displacement-operator-derived effective mass Hamiltonian. By linearizing the algebra resulting from SUSY-QM factorization of the constructed systems, their coherent states are defined and shown to be exponentially dependent on a function of the quantum numbers.

  3. Coulomb displacement energy calculations for the A=28;T=1 Triad

    International Nuclear Information System (INIS)

    Coulomb energy displacements have been calculated for the A=28;T=1 triad using shell model wave functions. Averaging the small deviations between calculated and available experimental values, one has calculated six additional 28Si;T=1 levels of which four can be associated with experimental levels with previously unknown T-values

  4. Water

    Science.gov (United States)

    ... or walk, especially on a hot day. Remember, water is a good way to add fluids to your daily routine without adding calories. Learn More: Important Nutrients to Know Healthy Lifestyle Related publications: Go4Life: Drinking Enough Fluids (PDF, 570K) ...

  5. Gamma radiation-induced grafting of glycidyl methacrylate to water hyacinth fibers: functionalization and metal ion uptake kinetics

    International Nuclear Information System (INIS)

    Water hyacinth fibers (WHF) were functionalized using gamma radiation-induced graft polymerization of glycidyl methacrylate (GMA) to obtain fibers with oxirane groups for chemical modification. The simultaneous grafting technique was employed wherein the WHF were irradiated in nitrogen atmosphere in the presence of GMA dissolved in water/methanol solvent. The effects of different grafting parameters to the grafting yield were evaluated. The optimal values of solvent, radiation absorbed dose, dose rate, concentration of monomer were found to be 1:3 (volume/volume) water-methanol solvent, 10 kGy, 8 kGy hour -1 dose rate and 5% (volume/volume) GMA, respectively. Using the optimum conditions, grafting yield approximately 58% was achieved. The GMA grafted WHF were subsequently modified with ethylenediamine and sodium sulfite. The resulting amine and sulfonic acid functionalized WHF, together with the grafted WHF, were characterized using Attenuated Total Reflectance-Fourier Transformed Infrared Spectroscopy (ATR-FTIR). Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The sorption of Cu2+, Cr3+ and Pb2+ ions on the amine functionalized WHF was studied. The initial concentration of the metal ions and pH of the solution were found to have important effect on the adsorption of the metal ions onto the amine functionalized WHF. The kinetics of adsorption was observed t The kinetics of adsorption was observed to follow Lagergren first order equation. Results of ion sorption studies indicate that radiation induced grafting and subsequent chemical modification improved the ion sorption behavior of WHF. (author)

  6. Adsorption of surface functionalized silica nanoparticles onto mineral surfaces and decane/water interface

    International Nuclear Information System (INIS)

    The adsorption of silica nanoparticles onto representative mineral surfaces and at the decane/water interface was studied. The effects of particle size (the mean diameters from 5 to 75 nm), concentration and surface type on the adsorption were studied in detail. Silica nanoparticles with four different surfaces [unmodified, surface modified with anionic (sulfonate), cationic (quaternary ammonium (quat)) or nonionic (polyethylene glycol (PEG)) surfactant] were used. The zeta potential of these silica nanoparticles ranges from ?79.8 to 15.3 mV. The shape of silica particles examined by a Hitachi-S5500 scanning transmission electron microscope (STEM) is quite spherical. The adsorption of all the nanoparticles (unmodified or surface modified) on quartz and calcite surfaces was found to be insignificant. We used interfacial tension (IFT) measurements to investigate the adsorption of silica nanoparticles at the decane/water interface. Unmodified nanoparticles or surface modified ones with sulfonate or quat do not significantly affect the IFT of the decane/water interface. It also does not appear that the particle size or concentration influences the IFT. However, the presence of PEG as a surface modifying material significantly reduces the IFT. The PEG surface modifier alone in an aqueous solution, without the nanoparticles, yields the same IFT reduction for an equivalent PEG concentration as that used for modifying the surface of nanoparticles. Contact angle measurementsanoparticles. Contact angle measurements of a decane droplet on quartz or calcite plate immersed in water (or aqueous nanoparticle dispersion) showed a slight change in the contact angle in the presence of the studied nanoparticles. The results of contact angle measurements are in good agreement with experiments of adsorption of nanoparticles on mineral surfaces or decane/water interface. This study brings new insights into the understanding and modeling of the adsorption of surface-modified silica nanoparticles onto mineral surfaces and water/decane interface.

  7. Functional-analytical capabilities of GIS technology in the study of water use risks

    Science.gov (United States)

    Nevidimova, O. G.; Yankovich, E. P.; Yankovich, K. S.

    2015-02-01

    Regional security aspects of economic activities are of great importance for legal regulation in environmental management. This has become a critical issue due to climate change, especially in regions where severe climate conditions have a great impact on almost all types of natural resource uses. A detailed analysis of climate and hydrological situation in Tomsk Oblast considering water use risks was carried out. Based on developed author's techniques an informational and analytical database was created using ArcGIS software platform, which combines statistical (quantitative) and spatial characteristics of natural hazards and socio-economic factors. This system was employed to perform areal zoning according to the degree of water use risks involved.

  8. Effects of soil water repellency on microbial community structure and functions in Mediterranean pine forests

    Science.gov (United States)

    Lozano, Elena; Grayston, Sue J.; Mataix-Solera, Jorge; Arcenegui, Victoria; Jimenez-Pinilla, Patricia; Mataix-Beneyto, Jorge

    2015-04-01

    Soil water repellency (SWR) is a property commonly observed in forest areas showing wettable and water repellent patches with high spatial variability. SWR can greatly influence the hydrology and the ecology of forest soils. The capacity of soil microorganisms to degrade different organic compounds depends upon species composition, so this may affect changes in SWR on the microsite scale (such as the presence of soil water repellent patches; Mülleret al., 2010). In the Mediterranean forest context, SWR has been found to be related to microbial community composition. The accumulation of different hydrophobic compounds might be causing the shifts in microbial community structure (Lozano et al., 2014). In this study we investigated the effects of SWR persistence on soil microbial community structure and enzyme activity under Pinus halepensis forest in three different sites: Petrer, Gorga and Jávea (Alicante, E Spain). Soil samples were classified into three different water repellency classes (wettable, slight or strongly water repellent samples) depending on the SWR persistence. The soil microbial community was determined through phospholipid fatty acids (PLFAs). Enzyme activities chosen for this study were cellulase, ?-glucosidase and N-acetyl-?-glucosaminide (NAG). The relationships between microbiological community structure and some soil properties such as pH, Glomalin Related Soil Protein, soil organic matter content and soil respiration were also studied. Redundancy analyses and decomposition of the variances were performed to clarify how microbial community composition and enzyme activities are affected by SWR and soil properties. The effect of SWR on microbial community composition differed between locations. This effect was clearer in the Petrer site. Enzyme activity varied considerably depending on SWR persistence. The highest activities were found in slightly SWR samples and the lowest mostly in the strongly water repellent ones. These preliminary results suggest a possible influence of SWR on microbial structure and its activity in soils. References: Lozano, E., García-Orenes, F., Bárcenas-Moreno, G., Jiménez-Pinilla, P., Mataix-Solera, J., Arcenegui, V., Morugán-Coronado, A., Mataix-Beneyto, J., 2014. Relationships between soil water repellency and microbial community composition under different plant species in a Mediterranean semiarid forest. J. Hydrol. Hydromech., 62, 101-107 Müller, K., Deurer, M., Newton, P.C.D., 2010. Is there a link between elevated atmospheric carbon dioxide concentration, soil water repellency and soil carbon mineralization? Agric. Ecosyst. Environ., 139, 98-109. Acknowledgements: to the "Ministerio de Economía and Competitividad" of Spanish Government for finance the POSTFIRE project (CGL2013- 47862-C2-1-R), Generalitat Valenciana for PhD grant, and Spanish Soil Science Society and FUEGORED for their support.

  9. Food and water intake as functions of resource consumption costs in a closed economy.

    OpenAIRE

    Mathis, C. E.; Johnson, D. F.; Collier, G.

    1996-01-01

    In two experiments, rats living in a closed economy were offered continuous, concurrent access to four resources: food, water, a nest, and a running wheel. Costs of consuming food and water were imposed with bar-press requirements, and the price of either one or both resources was raised. As the consumption cost increased, less was consumed in each bout of resource use. Bout frequency increased, but not sufficiently to compensate for the fall in bout size, and total intake fell. Food and wate...

  10. An Instrument for In Situ Measuring the Volume Scattering Function of Water: Design, Calibration and Primary Experiments

    Directory of Open Access Journals (Sweden)

    Chaoying Guo

    2012-04-01

    Full Text Available The optical volume scattering function (VSF of seawater is a fundamental property used in the calculation of radiative transfer for applications in the study of the upper-ocean heat balance, the photosynthetic productivity of the ocean, and the chemical transformation of photoreactive compounds. A new instrument to simultaneously measure the VSF in seven directions between 20° to 160°, the attenuation coefficient, and the depth of water is presented. The instrument is self-contained and can be automatically controlled by the depth under water. The self-contained data can be easily downloaded by an ultra-short-wave communication system. A calibration test was performed in the laboratory based on precise estimation of the scattering volume and optical radiometric calibration of the detectors. The measurement error of the VSF measurement instrument has been estimated in the laboratory based on the Mie theory, and the average error is less than 12%. The instrument was used to measure and analyze the variation characteristics of the VSF with angle, depth and water quality in Daya Bay for the first time. From these in situ data, we have found that the phase functions proposed by Fournier-Forand, measured by Petzold in San Diego Harbor and Sokolov in Black Sea do not fit with our measurements in Daya. These discrepancies could manly due to high proportion of suspended calcium carbonate mineral-like particles with high refractive index in Daya Bay.

  11. Homodyne and heterodyne optical interferometry for frequency dependent piezoelectric displacement measurement

    Science.gov (United States)

    Delahoussaye, Keith; Guo, Ruyan; Bhalla, Amar

    2014-09-01

    The electromechanical coupling in piezoelectric materials has been widely studied however a unified view of this interaction as function of frequencies using different measurement techniques has not previously been available. This study examines and compares multiple optical based homodyne and heterodyne interferometry techniques for displacement measurement over a wide range of frequencies and including a comparison made by using a commercial Laser Doppler Vibrometer. Ferroelectric lead titanate PbTiO3 with high ferroelectric strain is studied in this work. Frequency dependence of the electromechanical displacement is obtained using multiple techniques and the emphasis is given to near resonant frequency interrogations.

  12. Interfraction patient motion and implant displacement in prostate high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To quantify movement of prostate cancer patients undergoing treatment, using an in-house developed motion sensor in order to determine a relationship between patient movement and high dose rate (HDR) brachytherapy implant displacement. Methods: An electronic motion sensor was developed based on a three axis accelerometer. HDR brachytherapy treatment for prostate is delivered at this institution in two fractions 24 h apart and 22 patients were monitored for movement over the interval between fractions. The motion sensors functioned as inclinometers, monitoring inclination of both thighs, and the inclination and roll of the abdomen. The implanted HDR brachytherapy catheter set was assessed for displacement relative to fiducial markers in the prostate. Angle measurements and angle differences over a 2 s time base were binned, and the standard deviations of the resulting frequency distributions used as a metric for patient motion in each monitored axis. These parameters were correlated to measured catheter displacement using regression modeling. Results: The mean implant displacement was 12.6 mm in the caudal direction. A mean of 19.95 h data was recorded for the patient cohort. Patients generally moved through a limited range of angles with a mean of the exception of two patients who spent in excess of 2 h lying on their side. When tested for a relationship between movement in any of the four monitored axes and the implant displacement, none was significant. Connt displacement, none was significant. Conclusions: It is not likely that patient movement influences HDR prostate implant displacement. There may be benefits to patient comfort if nursing protocols were relaxed to allow patients greater freedom to move while the implant is in situ.

  13. Comparison of Gas Displacement based on Thermometry in the Pulse Tube with Rayleigh Scattering

    Science.gov (United States)

    Hagiwara, Yasumasa; Nara, Kenichi; Ito, Seitoku; Saito, Takamoto

    A pulse tube refrigerator has high reliability because of its simple structure. Recently the level of development activity of the pulse tube refrigerator has increased, but the quantitative understanding of the refrigeration mechanism has not fully been obtained. Therefore various explanations were proposed. The concept of virtual gas piston in particular helps us to understand the function of a phase shifter such as a buffer tank and an orifice because the virtual gas piston corresponds to a piston of a Stirling refrigerator. However it is difficult to directly measure the averaged gas displacement which corresponds to the virtual gas piston because uniform gas flow such as a gas piston does not always exist. For example, there are a jet flow from orifice and circulated flows in a pulse tube, which are predicted theoretically. In spite of these phenomena, the averaged gas displacement is very important in practical use because it can simply predict the performance from the displacement. In this report, we calculate the averaged gas displacement and mass flow through an orifice. The mass flow is calculated from the pressure change in a buffer tank. The averaged gas displacement is calculated from temperature profiles in the pulse tube and the mass flow. It is necessary to measure temperature in the pulse tube as widely as possible in order to calculate the averaged gas displacement. We apply a method using the Rayleigh Scattering the thermometry in the pulse tube. With this method, it is possible to perform 2-dimensional measurement without disturbing the gas flow. By this method, the averaged gas displacements and the temperature profiles of basic and orifice types of refrigeration were compared.

  14. A Probe of Fiber Optic OTDR Displacement Sensor

    International Nuclear Information System (INIS)

    The probes of fiber optic OTDR (Optical Time Domain Reflectometry) sensor was developed to measure displacements of social infrastructures. This probe was simply constructed with two conventional optical fiber connectors, and a fiber bending part, which transforms displacement to optical loss. When the displacement was affected on the bending loss part, the reflected light intensity of one optical connector was changed. The displacement was determined from this reflected light intensity change of the connector. Fiber optic OTDR displacement sensor was developed as the multiplexed type of one fiber line with 5 sensor probes. Multiplexing operation was tested by these 5 sensor probes

  15. Properties of novel anion selective material with DABCO functional groups for alkaline water electrolysis.

    Czech Academy of Sciences Publication Activity Database

    Hnát, J.; Žitka, Jan; Paidar, M.; Bouzek, K.

    Prague : University of Chemistry and Technology, Czech Hydrogen Technology Platform, 2015 - (Bouzek, K.; Doucek, A.). s. 28 ISBN 978-80-7080-920-4. [International Conference on Hydrogen Technologies /6./ - Hydrogen Days 2015. 18.03.2015-20.03.2015, Prague] Institutional support: RVO:61389013 Keywords : alkaline water electrolysis * anion selective polymer electrolyte * zero-gap arrangement Subject RIV: CD - Macromolecular Chemistry

  16. Function of the Membrane Water Channel Aquaporin-5 in the Salivary Gland

    International Nuclear Information System (INIS)

    The process of saliva production in the salivary glands requires transepithelial water transfer from the interstitium to the acinar lumen. There are two transepithelial pathways: the transcellular and paracellular. In the transcellular pathway, the aquaporin water channels induce passive water diffusion across the membrane lipid bilayer. It is well known that aquaporin-5 (AQP5) is expressed in the salivary glands, in which it is mainly localized at the apical membrane of the acinar cells. This suggests the physiological importance of AQP5 in transcellular water transfer. Reduced saliva secretion under pilocarpine stimulation in AQP5-null mice compared with normal mice further indicates the importance of AQP5 in this process, at least in stimulated saliva secretion. Questions remain therefore regarding the role and importance of AQP5 in basal saliva secretion. It has been speculated that there would be some short-term regulation of AQP5 such as a trafficking mechanism to regulate saliva secretion. However, no histochemical evidence of AQP5-trafficking has been found, although some of biochemical analyses suggested that it may occur. There are no reports of human disease caused by AQP5 mutations, but some studies have revealed an abnormal subcellular distribution of AQP5 in patients or animals with xerostomia caused by Sjögren’s syndrome and X-irradiation. These findings suggest the possible pathophysiological importance of AQP5 in the salivary glands

  17. Superconducting inductive displacement detection of a microcantilever

    Energy Technology Data Exchange (ETDEWEB)

    Vinante, A., E-mail: anvinante@fbk.eu [Istituto di Fotonica e Nanotecnologie, CNR - Fondazione Bruno Kessler, I-38123 Povo, Trento (Italy)

    2014-07-21

    We demonstrate a superconducting inductive technique to measure the displacement of a micromechanical resonator. In our scheme, a type I superconducting microsphere is attached to the free end of a microcantilever and approached to the loop of a dc Superconducting Quantum Interference Device (SQUID) microsusceptometer. A local magnetic field as low as 100??T, generated by a field coil concentric to the SQUID, enables detection of the cantilever thermomechanical noise at 4.2?K. The magnetomechanical coupling and the magnetic spring are in good agreement with image method calculations assuming pure Meissner effect. These measurements are relevant to recent proposals of quantum magnetomechanics experiments based on levitating superconducting microparticles.

  18. Simulating People Moving in Displacement Ventilated Rooms

    DEFF Research Database (Denmark)

    Mattsson, M.; BjØrn, Erik

    1997-01-01

    A displacement ventilation system works better the more uni-directional the air flow through the ventilated room is: from floor to ceiling. Thus, from an air quality point of view, there should be as little vertical mixing of the room air as possible. It is therefore comprehensible that physical activity in the room -like peoples movements -in previous studies has been shown to influence the effectiveness of the ventilation. In this study we have compared results from previous tests, where a cylindrical person simulator was used, to results obtained when using a person simulator of more human-like shape.

  19. Displacement Ventilation : effects of movement and exhalation

    DEFF Research Database (Denmark)

    BjØrn, Erik; Mattsson, Magnus

    1997-01-01

    Full-scale experiments were made in a displacement ventilated room with two breathing thermal manikins to study the effect of movements and breathing on the vertical contaminant distribution, and on the personal exposure of occupants. Concentrations were measured with tracer gas equipment in the room and in the inhalation of both manikins. Tracer gas was added in the heat plume above a sitting manikin, or in the exhalation through either the nose or the mouth. The other manikin moved back and forth at different speeds on a low trolley. The mentioned experimental conditions have a significant influence on contaminant distributions and personal exposures.

  20. Superconducting inductive displacement detection of a microcantilever

    CERN Document Server

    Vinante, Andrea

    2014-01-01

    We demonstrate a superconducting inductive technique to measure the displacement of a micromechanical resonator. In our scheme, a type I superconducting microsphere is attached to the free end of a microcantilever and approached to the loop of a dc Superconducting Quantum Interference Device (SQUID) microsusceptometer. A local magnetic field as low as 100 $\\mu$T, generated by a field coil concentric to the SQUID, enables detection of the cantilever thermomechanical noise at $4.2$ K. The magnetomechanical coupling and the magnetic spring are in good agreement with image method calculations assuming pure Meissner effect. These measurements are relevant to recent proposals of quantum magnetomechanics experiments based on levitating superconducting microparticles.

  1. Superconducting inductive displacement detection of a microcantilever

    International Nuclear Information System (INIS)

    We demonstrate a superconducting inductive technique to measure the displacement of a micromechanical resonator. In our scheme, a type I superconducting microsphere is attached to the free end of a microcantilever and approached to the loop of a dc Superconducting Quantum Interference Device (SQUID) microsusceptometer. A local magnetic field as low as 100??T, generated by a field coil concentric to the SQUID, enables detection of the cantilever thermomechanical noise at 4.2?K. The magnetomechanical coupling and the magnetic spring are in good agreement with image method calculations assuming pure Meissner effect. These measurements are relevant to recent proposals of quantum magnetomechanics experiments based on levitating superconducting microparticles.

  2. Dynamics and structure of energetic displacement cascades

    International Nuclear Information System (INIS)

    This paper summarizes recent progress in the understanding of energetic displacement cascades and the primary state of damage in metals. On the theoretical side, the availability of supercomputers has greatly enhanced our ability to simulate cascades by molecular dynamics. Recent application of this simulation technique to Cu and Ni provides new insight into the dynamics of cascade processes. On the experimental side, new data on ion beam mixing and in situ electron microscopy studies of ion damage at low temperatures reveal the role of the thermodynamic properties of the material on cascade dynamics and structure. 38 refs., 9 figs

  3. Inelastic cross-sections of energetic protons in liquid water calculated by model dielectric functions and optical data

    International Nuclear Information System (INIS)

    Total and differential inelastic inverse-mean-free-paths for the energy loss of protons in liquid water are calculated on the basis of the dielectric approach. Energetic protons, much above the Bragg peak, are considered where the first-Born-approximation is justified (?0.3-10 MeV). A model dielectric-response-function for the valence electrons of liquid water is constructed in accordance with the general properties of the Bethe-surface. A modified Drude-expansion model developed earlier provided the long-wavelength response, whereas several dispersion schemes were examined for introducing the momentum-transfer dependence. In particular, we have examined the ?-oscillator dispersion models of Ashley and Liljequist, and Ritchie's extended-Drude models. A comparison with optical dielectric models will also be presented for assessing the influence of the dispersion. In view of the limited experimental information for the inelastic properties of liquid water, the present work provides a comparative study of various - computationally tractable - schemes that may be used in analog Monte Carlo transport codes for protons and heavier ions in liquid water

  4. The Structure of Hydrated Electron. Part 1. Magnetic Resonance of Internally Trapping Water Anions: A Density Functional Theory Study

    CERN Document Server

    Shkrob, I A

    2006-01-01

    Density functional theory (DFT) is used to rationalize magnetic parameters of hydrated electron trapped in alkaline glasses as observed using Electron Paramagnetic Resonance (EPR) and Electron Spin Echo Envelope Modulation (ESEEM) spectroscopies. To this end, model water cluster anions (n=4-8 and n=20,24) that localize the electron internally are examined. It is shown that EPR parameters of such water anions (such as hyperfine coupling tensors of H/D nuclei in the water molecules) are defined mainly by the cavity size and the coordination number of the electron; the water molecules in the second solvation shell play a relatively minor role. An idealized model of hydrated electron (that is usually attributed to L. Kevan) in which six hydroxyl groups arranged in an octahedral pattern point towards the common center is shown to provide the closest match to the experimental parameters, such as isotropic and anisotropic hyperfine coupling constants for the protons (estimated from ESEEM), the second moment of the E...

  5. The structure of hydrated electron. Part 1. Magnetic resonance of internally trapping water anions : a density functional theory study.

    Energy Technology Data Exchange (ETDEWEB)

    Shkrob, I. A.; Chemistry

    2007-06-21

    Density functional theory is used to rationalize magnetic parameters of hydrated electron trapped in alkaline glasses as observed using electron paramagnetic resonance (EPR) and electron spin echo envelope modulation (ESEEM) spectroscopies. To this end, model water cluster anions (n = 4-8 and n = 20, 24) that localize the electron internally are examined. It is shown that hyperfine coupling tensors of H/D nuclei in the water molecules are defined mainly by the cavity size and the coordination number of the electron; the water molecules in the second solvation shell play a relatively minor role. An idealized model of the hydrated electron (that is usually attributed to L. Kevan) in which six hydroxyl groups arranged in an octahedral pattern point toward the common center is shown to provide the closest match to the experimental parameters, such as isotropic and anisotropic hyperfine coupling constants for the protons (estimated from ESEEM), the second moment of the EPR spectra, and the radius of gyration. The salient feature is the significant transfer (10-20%) of spin density into the frontal O 2p orbitals of water molecules. Spin bond polarization involving these oxygen orbitals accounts for small, negative hyperfine coupling constants for protons in hydroxyl groups that form the electron-trapping cavity. In Part 2, these results are generalized for more realistic geometries of core anions obtained using a dynamic one-electron mixed quantum/classical molecular dynamics model.

  6. A density functional theory study on the degradation mechanism of thin film of organic semiconductor by water molecules

    International Nuclear Information System (INIS)

    Hybrid density functional theory calculations have been carried out for the organic-inorganic hybrid complex of 1,4,5,8-naphthalene-tetracarboxylic-dianhydride (NTCDA) with an indium atom (In) to elucidate the degradation mechanism of thin films of molecular organic semiconductors by water molecules. This compound has been used as an organic semiconductor. The band gap of NTCDA was calculated to be as high as 3.39 eV as a single molecule, whereas a new band of NTCDA was formed as low-lying excited state (1.64 eV) after the interaction with the In atom. The water molecule attacked preferentially the In atom of In-NTCDA, and the solvation structure was formed around the In atom (solvation). Further addition of a water molecule to the system, the In atom is stripped off from NTCDA by water molecules, and solvation shell around the In atom is formed (separated solvation). The hydrogen-bond network was broken by the formation of solvation shell. The mechanism of degradation of the electron conductivity has been discussed on the basis of theoretical results

  7. Groyne fields--sink and source functions of "flow-reduced zones" for water content in the River Elbe (Germany).

    Science.gov (United States)

    Ockenfeld, K; Guhr, H

    2003-01-01

    The role of man-made "flow-reduced zones" as a sink or a source of water content is unknown for the River Elbe, Germany. We measured and compared: a) the concentration of suspended matter at the inflow and the outflow of one special groyne field ("UFZ groyne field") weekly for a period of two years; and b) the intensity of oxygen metabolism within several groyne fields and the main stream during a Lagrangian survey. Under discharge conditions near or below mean water, we found a significant reduction of suspended particulate matter and particle bound nutrients in the "UFZ groyne field". In contrast, concentrations of most soluble water contents and chlorophyll a did not significantly change between in- and outflow. During the Lagrangian survey, pelagic production and respiration rates developed nearly identically in both the main stream and the adjacent groyne fields but oxygen time curves showed higher amplitudes for the groyne fields compared to the river. This higher net-oxygen production in the groyne fields is due to reduced water depth and reduced stream velocity. It enhances the concentration of oxygen in the main stream. The contrary results show the coexistence of both sink and source functions of "flow-reduced zones" in rivers. PMID:14653630

  8. Elemental distribution and uptake by watercress (Nasturtium aquaticum) as a function of water quality.

    Science.gov (United States)

    Kisten, Kimona; Gounden, Denisha; Moodley, Roshila; Jonnalagadda, Sreekantha B

    2015-06-01

    Watercress (Nasturtium aquaticum), is an edible plant commonly found in Southern Africa, which grows both in terrestrial and aquatic environments. The elemental concentrations in the plant and surrounding water (growth solution) were investigated to determine the plants nutritional value and to establish impact of water quality on elemental uptake by the plant. The concentrations in the leaves, roots and water were analyzed at eight different sites along the east coast of KwaZulu-Natal, South Africa (30.0000° S, 25.0000° E). Elemental concentrations in the leaves/roots (?g g(-1), dry mass) and water exchangeable/total (?g L(-1)) at Verulam (situated in the northern part of KwaZulu-Natal) were: As (1.2/7.5 and 0.053/0.09), Ca (18272/26091 and 0.336/7.15), Cd (0.9/0.8 and 0.004/0.01), Co (37.2/34 and 0/0), Cr (7/35 and 0.003/0.03), Cu (3/19 and 0.016/0.16), Fe (528/4308 and 0.375/0.6), Mg (3444/1141 and 6.4/7), Mn (110/667 and 0/0), Ni (20/63 and 0/0.01), Pb (16/17 and 0.01/0.02), Se (28/11 and 0.003/0.01) and Zn (102/116 and 0.099/0.36). Elemental uptake was controlled by the plant but water quality did have an impact on uptake. Concentrations of metals in the leaves were in decreasing order of Ca > Mg > Fe > Mn > Zn > Cu > Cr > Ni > Pb > Se > Cd > As > Co. The watercress plant was found to be a rich source of essential elements especially Fe and Cr and contained low concentrations of the toxic metals investigated thereby making it safe for human consumption. PMID:25844866

  9. Selective displacement chromatography in multimodal cation exchange systems.

    Science.gov (United States)

    Sheth, Rahul D; Morrison, Christopher J; Cramer, Steven M

    2011-12-23

    A library of displacer analogues with varying degrees of electrostatic, hydrophobic and hydrogen bonding moieties was evaluated for their ability to enhance the selectivity of multimodal (MM) chromatography under high loading conditions. The library was screened for displacement of model proteins using a robotic liquid handling system and selective batch separations were achieved for proteins that were inseparable with linear gradient chromatography. Trends in protein displacement were identified and displacers with higher hydrophobicity and net charge exhibited improved protein displacements. Proteins that interacted with the resins primarily via electrostatic interactions were more readily displaced than those that possessed a significant hydrophobic contribution to their binding. In addition, multimodal displacers were found to be more selective than single mode electrostatic displacers. Column chromatography studies were also carried out and baseline separations were achieved for model protein pairs using selective displacement. Finally, operation of these columns in the desorption mode resulted in baseline separation of model proteins which were not separable by selective displacement chromatography. This study indicates that the inherent selectivity of MM resins can be augmented by the selectivity of the displacer under non-linear competitive binding conditions, creating new opportunities for protein separations not possible using traditional gradient operations. PMID:22098931

  10. Alexander Duality for Functions: the Persistent Behavior of Land and Water and Shore

    OpenAIRE

    Edelsbrunner, Herbert; Kerber, Michael

    2011-01-01

    This note contributes to the point calculus of persistent homology by extending Alexander duality to real-valued functions. Given a perfect Morse function $f: S^{n+1} \\to [0,1]$ and a decomposition $S^{n+1} = U \\cup V$ such that $M = \\U \\cap V$ is an $n$-manifold, we prove elementary relationships between the persistence diagrams of $f$ restricted to $U$, to $V$, and to $M$.

  11. Pulse tube stirling machine with warm gas-driven displacer

    Science.gov (United States)

    Zhu, Shaowei; Nogawa, Masafumi

    2010-05-01

    A pulse tube type stirling machine with warm gas-driven displacer which has a displacer rod is discussed with numerical simulation when it is used as a cryogenic refrigerator, room temperature refrigerator and engine. It has both the advantages of gas-driven-stirling machine with high efficiency and simplicity and the advantages of pulse tube machine with no moving parts at low temperatures. A nodal analysis method that includes the linear motor and the displacer in the machine is introduced. Numerical results show that it has high potential to be used as the cryogenic refrigerator, room temperature refrigerator and engine. In this type of machine, there is an optimum phase angle between displacer and piston, and an optimum swept volume ratio of displacer over compressor for efficiency. The phase angle and swept volume ratio can be adjusted by the natural frequency of the displacer and the diameter of the displacer rod when it is used as a refrigerator.

  12. Optimum design of seat region in valves suitable for digital displacement machines

    DEFF Research Database (Denmark)

    Roemer, Daniel Beck; Johansen, Per

    2014-01-01

    Digital displacement fluid power is an upcoming technology setting new standards for the achievable efficiency in variable displacement fluid power pumps and motors. In the present work, an annular seat valve suitable for use in digital displacement units is considered, and the valve geometry is optimised considering both the mechanical strength during pressure loading and fluid flow restriction in the open valve state. Material stresses are modelled using finite element (FE) analysis including non-linear material behaviour, contact elements and fluid pressure penetrating load, closely reflecting the actual load of the seat valve connected to a fluid pressure chamber. Valve pressure losses are modelled using computational fluid dynamics (CFD). On basis of an overall physical size requirement and material specification, optimum valve geometry and stroke length are given as function of a defined normalised flow coefficient directly related to the machine efficiency.

  13. Nomarski imaging interferometry to measure the displacement field of micro-electro-mechanical systems

    International Nuclear Information System (INIS)

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

  14. Fabrication and characterization of wide band AE sensors for quantitative detection of displacement and velocity

    International Nuclear Information System (INIS)

    Acoustic emission sensors to show a flat response for displacement and velocity of a specimen surface in a wide frequency were fabricated. The sensors were conical sensors employing conical type piezoelectric elements and a PVDF sensor employing PVDF piezoelctric polymer. The transient outputs of the sensors due to step-like forces and their sensitivity spectrum were measured. The results were compared with the theoretical displacement and velocity signals calculated using Green's function and a simulated ramp force. The sensor outputs and the theoretical signals were consistent with each other. The sensors showed flat sensitivity spectra in the wide frequency range. The present work showed that conical PZT sensors are suited for the direct measurement of vertical displacement, and PVDF sensors for that of the vertical velocity of a plate surface.

  15. Displacement threshold and Frenkel pair formation energy in ionic systems

    International Nuclear Information System (INIS)

    Displacement threshold energies (Ed) and Frenkel pair formation energies (EFp) are investigated in detail by molecular dynamics computer simulation for three different ionic systems with the same crystal structure, MgO, SrO and NaCl in order to see if there is a functional relationship between them. It is found that there are wide variations in the values of Ed depending on the direction in which energy is imparted to a static atom in the lattice. Large values of Ed are found along the major crystallographic directions and lower values elsewhere. Typically these thresholds are between 5 and 9 times bigger than the Frenkel pair formation energies EFp with no observable dependence on mass or ion charge. The differences in the interaction potentials also means that for any given direction, there is only limited correlation between values of Ed in the different systems studied and no quantifiable relationship with EFp.

  16. Off-Axis Gaussian Beams with Random Displacement in Atmospheric Turbulence

    Directory of Open Access Journals (Sweden)

    Yahya Baykal

    2006-10-01

    Full Text Available Our recent work in which we study the propagation of the general Hermite-sinusoidal-Gaussian laser beams in wireless broadband access telecommunication systems is elaborated in this paper to cover the special case of an off-axis Gaussian beam. We mainly investigate the propagation characteristics in atmospheric turbulence of an off-axis Gaussian beam possessing Gaussian distributed random displacement parameters. Our interest is to search for different types of laser beams that will improve the performance of a wireless broadband access system when atmospheric turbulence is considered. Our formulation is based on the basic solution of the second order mutual coherence function evaluated at the receiver plane. For fixed turbulence strength, the coherence length calculated at the receiver plane is found to decrease as the variance of the random displacement is increased. It is shown that as the turbulence becomes stronger, coherence lengths due to off-axis Gaussian beams tend to approach the same value, irrespective of the variance of the random displacement. As expected, the beam spreading is found to be pronounced for larger variance of displacement parameter. Average intensity profiles when atmospheric turbulence is present are plotted for different values of the variance of the random displacement parameter of the off-axis Gaussian beam.

  17. Wireless Displacement Sensing of Micromachined Spiral-Coil Actuator Using Resonant Frequency Tracking

    Directory of Open Access Journals (Sweden)

    Mohamed Sultan Mohamed Ali

    2014-07-01

    Full Text Available This paper reports a method that enables real-time displacement monitoring and control of micromachined resonant-type actuators using wireless radiofrequency (RF. The method is applied to an out-of-plane, spiral-coil microactuator based on shape-memory-alloy (SMA. The SMA spiral coil forms an inductor-capacitor resonant circuit that is excited using external RF magnetic fields to thermally actuate the coil. The actuation causes a shift in the circuit’s resonance as the coil is displaced vertically, which is wirelessly monitored through an external antenna to track the displacements. Controlled actuation and displacement monitoring using the developed method is demonstrated with the microfabricated device. The device exhibits a frequency sensitivity to displacement of 10 kHz/µm or more for a full out-of-plane travel range of 466 µm and an average actuation velocity of up to 155 µm/s. The method described permits the actuator to have a self-sensing function that is passively operated, thereby eliminating the need for separate sensors and batteries on the device, thus realizing precise control while attaining a high level of miniaturization in the device.

  18. On the Spatial Ambiguity Function

    CERN Document Server

    Yuryev, Arthur N

    2014-01-01

    The ambiguity function of a spatial signal in the "signal spatial frequency displacement vs antenna linear displacement" coordinates is considered in this paper; in case of a monochromatic signal with known carrier frequency, spatial signal vector angular displacement is considered as the second coordinate. The analysis is made taking into account an external (reradiated or thermal) background which contributes considerable peculiarities in the properties of the spatial ambiguity function. Accuracy of measuring the signal linear or angular displacement and resolution are determined. Examples for the Fresnel and Fraunhofer zones are given.

  19. Electronic structure and reactivity in water splitting of the iron oxide dimers and their hexacarbonyls: A density functional study

    International Nuclear Information System (INIS)

    The iron oxide dimers (FeO)2 and their peroxide isomers are studied with the B3LYP density functional as bare clusters and as hexacarbonyls. Among the bare clusters the planar four-member ring structures are more stable than the non-planar ones and the rhombic dioxide Fe2O2 with antiferromagnetically ordered electrons on iron centers is the global minimum. Water adsorption on the bare diiron dioxide is exothermic, but dissociation does not occur. Carbonylation favors a non-planar Fe2O2 ring for both the dioxides and the peroxides and high electron density at the Fe centers is induced, evidenced by the natural charge distribution, the high proton affinity, and the values of global electronegativity and hardness. The iron dioxide hexacarbonyl Fe2O2(CO)6 is diamagnetic in the state of the global minimum. It is separated from the next low-lying triplet state by a small energy gap of 0.22 eV. Time-dependent density functional theory methods were applied to examine electron excitations from the ground state to the low-lying triplet states in the hexacarbonyls and their adsorption complexes with water. Singlet-to-triplet state excitations occur via ligand-to-metal charge transfer in the hexacarbonyls; in the adsorption complexes excitations from the oxygen lone pairs to the adsorption center also occur and they appear in the IR-visible region. The lowest energy singlet and triplet state reaction paths for water splitting were followed. On the singlet potential energy surface (PES), water splitting is spontaneous, while for the triplet PES an activation barrier of 14.1 kJ mol?1 was determined

  20. Determination of Alkalinity and dissociation constants of high salinity waters: use of F5BC titration function

    Scientific Electronic Library Online (English)

    B.F, Cavalcanti; L.C.L, Agostinho; L, Nascimento.

    Full Text Available Medições de parâmetros expressos em termos de espécies carbônicas tais como Alcalinidade e Acidez de águas Salinas não analisam a influencia de parâmetros externos tais como Concentração de Espécies Carbônicas livre e associada, formação de pares iônicos e Potencial de Residual de Junção Líquida em [...] medições de pH. Este artigo mostra o desenvolvimento da função titulométrica F5BC com base nas titulações desenvolvidas por Gran (1952) para o sistema carbonatado de águas naturais. Para uso prático, amostras de água salina do açude de Pocinhos, PB foram submetidas à titulação e análise de regressão linear. Os resultados mostraram que a função F5BC compreende a determinação das funções tipo Gran F1x e F2x, respectivamente, para a obtenção de Alcalinidade e de Acidez sem conhecer "a priori" o ponto final da titulação. A função F5BC permite também a determinação da Primeira e da Segunda Constante Aparente de Dissociação do sistema carbonatado de águas salinas e de alta força iônica. Abstract in english Measurements of parameters expressed in terms of carbonic species such as Alkalinity and Acidity of saline waters do not analyze the influence of external parameters to the titration such as Total free and associated Carbonic Species Concentration, activity coefficient, ion pairing formation and Res [...] idual Liquid Junction Potential in pH measurements. This paper shows the development of F5BC titration function based on the titrations developed by Gran (1952) for the carbonate system of natural waters. For practical use, samples of saline waters from Pocinhos reservoir in Paraiba were submitted to titration and linear regression analysis. Results showed that F5BC involves F1x and F2x Gran functions determination, respectively, for Alkalinity and Acidity calculations without knowing "a priori" the endpoint of the titration. F5BC also allows the determination of the First and Second Apparent Dissociation Constant of the carbonate system of saline and high ionic strength waters.

  1. An extensin-rich matrix lines the carinal canals in Equisetum ramosissimum, which may function as water-conducting channels

    Science.gov (United States)

    Leroux, O.; Knox, J. P.; Masschaele, B.; Bagniewska-Zadworna, A.; Marcus, S. E.; Claeys, M.; van Hoorebeke, L.; Viane, R. L. L.

    2011-01-01

    Background and Aims The anatomy of Equisetum stems is characterized by the occurrence of vallecular and carinal canals. Previous studies on the carinal canals in several Equisetum species suggest that they convey water from one node to another. Methods Cell wall composition and ultrastructure have been studied using immunocytochemistry and electron microscopy, respectively. Serial sectioning and X-ray computed tomography were employed to examine the internode–node–internode transition of Equisetum ramosissimum. Key Results The distribution of the LM1 and JIM20 extensin epitopes is restricted to the lining of carinal canals. The monoclonal antibodies JIM5 and LM19 directed against homogalacturonan with a low degree of methyl esterification and the CBM3a probe recognizing crystalline cellulose also bound to this lining. The xyloglucan epitopes recognized by LM15 and CCRC-M1 were only detected in this lining after pectate lyase treatment. The carinal canals, connecting consecutive rings of nodal xylem, are formed by the disruption and dissolution of protoxylem elements during elongation of the internodes. Their inner surface appears smooth compared with that of vallecular canals. Conclusions The carinal canals in E. ramosissimum have a distinctive lining containing pectic homogalacturonan, cellulose, xyloglucan and extensin. These canals might function as water-conducting channels which would be especially important during the elongation of the internodes when protoxylem is disrupted and the metaxylem is not yet differentiated. How the molecularly distinct lining relates to the proposed water-conducting function of the carinal canals requires further study. Efforts to elucidate the spatial and temporal distribution of cell wall polymers in a taxonomically broad range of plants will probably provide more insight into the structural–functional relationships of individual cell wall components or of specific configurations of cell wall polymers. PMID:21752793

  2. Consumption of water containing over 3.5 mg of dissolved hydrogen could improve vascular endothelial function

    Directory of Open Access Journals (Sweden)

    Sakai T

    2014-10-01

    Full Text Available Takaaki Sakai,1 Bunpei Sato,2 Koji Hara,3 Yuichi Hara,3 Yuji Naritomi,3 Samon Koyanagi,1 Hiroshi Hara,3 Tetsuhiko Nagao,4 Toru Ishibashi51Department of Cardiology, Haradoi Hospital, Fukuoka, Japan; 2MiZ Company Limited, Fujisawa, Kanagawa, Japan; 3Department of Internal Medicine, Haradoi Hospital, Fukuoka, Japan; 4Midorino Clinic, Aoba, Higashi-ku, Fukuoka, Japan; 5Department of Rheumatology and Orthopedic Surgery, Haradoi Hospital, Fukuoka, Japan Background: The redox imbalance between nitric oxide and superoxide generated in the endothelium is thought to play a pivotal role in the development of endothelial dysfunction. A third reactive oxygen species (ROS, H2O2, is known to have both beneficial and detrimental effects on the vasculature. Nonetheless, the influence of the hydroxyl radical, a byproduct of H2O2 decay, is unclear, and there is no direct evidence that the hydroxyl radical impairs endothelial function in conduit arteries. Molecular hydrogen (H2 neutralizes detrimental ROS, especially the hydroxyl radical. Objectives: To assess the influence of the hydroxyl radical on the endothelium and to confirm that a gaseous antioxidant, H2, can be a useful modulator of blood vessel function. Methods: The efficacy of water containing a high concentration of H2 was tested by measuring flow-mediated dilation (FMD of the brachial artery (BA. The subjects were randomly divided into two groups: the high-H2 group, who drank high-H2 water containing 7 ppm H2 (3.5 mg H2 in 500 mL water; and the placebo group. Endothelial function was evaluated by measuring the FMD of the BA. After measurement of diameter of the BA and FMD at baseline, volunteers drank the high-H2 water or placebo water immediately and with a 30-minute interval; FMD was compared to baseline. Results: FMD increased in the high-H2 group (eight males; eight females from 6.80%±1.96% to 7.64%±1.68% (mean ± standard deviation and decreased from 8.07%±2.41% to 6.87%±2.94% in the placebo group (ten males; eight females. The ratio to the baseline in the changes of FMD showed significant improvement (P<0.05 in the high-H2 group compared to the placebo group. Conclusion: H2 may protect the vasculature from shear stress-derived detrimental ROS, such as the hydroxyl radical, by maintaining the nitric oxide-mediated vasomotor response. Keywords: flow-mediated dilation, reactive oxygen species, molecular hydrogen, hydroxyl radical, 5–7 ppm, peroxynitrite

  3. Histone displacement during nucleotide excision repair

    DEFF Research Database (Denmark)

    Dinant, C.; Bartek, J.

    2012-01-01

    Nucleotide excision repair (NER) is an important DNA repair mechanism required for cellular resistance against UV light and toxic chemicals such as those found in tobacco smoke. In living cells, NER efficiently detects and removes DNA lesions within the large nuclear macromolecular complex called chromatin. The condensed nature of chromatin inhibits many DNA metabolizing activities, including NER. In order to promote efficient repair, detection of a lesion not only has to activate the NER pathway but also chromatin remodeling. In general, such remodeling is thought on the one hand to precede NER, thus allowing repair proteins to efficiently access DNA. On the other hand, after completion of the repair, the chromatin must be returned to its previous undamaged state. Chromatin remodeling can refer to three separate but interconnected processes, histone post-translational modifications, insertion of histone variants and histone displacement (including nucleosome sliding). Here we review current knowledge, and speculate about current unknowns, regarding those chromatin remodeling activities that physically displace histones before, during and after NER. © 2012 by the authors; licensee MDPI, Basel, Switzerland.

  4. Transient digitizer with displacement current samplers

    Science.gov (United States)

    McEwan, Thomas E. (Livermore, CA)

    1996-01-01

    A low component count, high speed sample gate, and digitizer architecture using the sample gates is based on use of a signal transmission line, a strobe transmission line and a plurality of sample gates connected to the sample transmission line at a plurality of positions. The sample gates include a strobe pickoff structure near the strobe transmission line which generates a charge displacement current in response to propagation of the strobe signal on the strobe transmission line sufficient to trigger the sample gate. The sample gate comprises a two-diode sampling bridge and is connected to a meandered signal transmission line at one end and to a charge-holding cap at the other. The common cathodes are reverse biased. A voltage step is propagated down the strobe transmission line. As the step propagates past a capacitive pickoff, displacement current i=c(dv/dT), flows into the cathodes, driving the bridge into conduction and thereby charging the charge-holding capacitor to a value related to the signal. A charge amplifier converts the charge on the charge-holding capacitor to an output voltage. The sampler is mounted on a printed circuit board, and the sample transmission line and strobe transmission line comprise coplanar microstrips formed on a surface of the substrate. Also, the strobe pickoff structure may comprise a planar pad adjacent the strobe transmission line on the printed circuit board.

  5. Dynamic response of electromagnetic spatial displacement trackers.

    Science.gov (United States)

    Adelstein, B D; Johnston, E R; Ellis, S R

    1996-01-01

    Overall system latency--the elapsed time from input human motion until the immediate consequences of that input are available in the display--is one of the most frequently cited shortcoming of current virtual environment (VE) technology. Given that spatial displacement trackers are employed to monitor head and hand position and orientation in many VE applications, the dynamic response intrinsic to these devices is an unavoidable contributor to overall system latency. In this paper, we describe a testbed and method for measurement of tracker dynamic response that use a motorized rotary swing arm to sinusoidally displace the VE sensor at a number of frequencies spanning the bandwidth of volitional human movement. During the tests, actual swing arm angle and VE sensor reports are collected and time stamped. By calibrating the time stamping technique, the tracker's internal transduction and processing time are separated from data transfer and host computer software execution latencies. We have used this test-bed to examine several VE sensors--most recently to compare latency, gain, and noise characteristics of two commercially available electromagnetic trackers: Ascension Technology Corp.'s Flock of Birds(TM) and Polhemus Inc.'s Fastrak(TM). PMID:11540397

  6. Meridional displacement of the Antarctic Circumpolar Current.

    Science.gov (United States)

    Gille, Sarah T

    2014-07-13

    Observed long-term warming trends in the Southern Ocean have been interpreted as a sign of increased poleward eddy heat transport or of a poleward displacement of the entire Antarctic Circumpolar Current (ACC) frontal system. The two-decade-long record from satellite altimetry is an important source of information for evaluating the mechanisms governing these trends. While several recent studies have used sea surface height contours to index ACC frontal displacements, here altimeter data are instead used to track the latitude of mean ACC transport. Altimetric height contours indicate a poleward trend, regardless of whether they are associated with ACC fronts. The zonally averaged transport latitude index shows no long-term trend, implying that ACC meridional shifts determined from sea surface height might be associated with large-scale changes in sea surface height more than with localized shifts in frontal positions. The transport latitude index is weakly sensitive to the Southern Annular Mode, but is uncorrelated with El Niño/Southern Oscillation. PMID:24891396

  7. Do alternative energy sources displace fossil fuels?

    Science.gov (United States)

    York, Richard

    2012-06-01

    A fundamental, generally implicit, assumption of the Intergovernmental Panel on Climate Change reports and many energy analysts is that each unit of energy supplied by non-fossil-fuel sources takes the place of a unit of energy supplied by fossil-fuel sources. However, owing to the complexity of economic systems and human behaviour, it is often the case that changes aimed at reducing one type of resource consumption, either through improvements in efficiency of use or by developing substitutes, do not lead to the intended outcome when net effects are considered. Here, I show that the average pattern across most nations of the world over the past fifty years is one where each unit of total national energy use from non-fossil-fuel sources displaced less than one-quarter of a unit of fossil-fuel energy use and, focusing specifically on electricity, each unit of electricity generated by non-fossil-fuel sources displaced less than one-tenth of a unit of fossil-fuel-generated electricity. These results challenge conventional thinking in that they indicate that suppressing the use of fossil fuel will require changes other than simply technical ones such as expanding non-fossil-fuel energy production.

  8. Embryonic development time of the freshwater mysid Limnomysis benedeni Czerniavsky as a function of water temperature

    OpenAIRE

    Hanselmann, Almut; Gergs, Rene?; Rothhaupt, Karl-otto

    2011-01-01

    The numbers of alien species in freshwater systems and their detrimental impacts on the stability of ecosystems and global species diversity are increasing. To predict and assess such impacts, a thorough knowledge of the autecology and life cycle of the alien species is required. Limnomysis benedeni is common and one of the most invasive mysids in Europe. Here we show a clear dependency of the development time of the brood of L. benedeni on water temperature. In laboratory experiment...

  9. Subcritical water extraction of nutraceuticals with antioxidant activity from oregano. Chemical and functional characterization

    OpenAIRE

    Rodri?guez Meizoso, Irene; Marin, Francisco R.; Herrero, Miguel; Sen?orans, F. Javier; Reglero, Guillermo; Cifuentes, Alejandro; Iba?n?ez, Elena

    2006-01-01

    In the present work, oregano leaves (Origanum vulgare L.) are explored as natural source of nutraceuticals with antioxidant activity. To do this, subcritical water extraction (SWE), a new environmentally friendly technique, is employed as extraction procedure and HPLC coupled to DAD is used for the chemical characterization of the extracts. Moreover, the radical scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and the determination of the total phenolic content (measured with t...

  10. Studies of water-in-oil emulsions : energy and work threshold as a function of temperature

    International Nuclear Information System (INIS)

    A study was conducted in which the effect of temperature on the kinetics and stability of water-in-oil formation was examined. Previous studies have shown that viscosity influences the formation and stability of water in oil emulsions, therefore a viscosity window has been postulated as necessary for the formation of stable emulsions. The temperature dependence of this physical property is examined through a study of 3 oils, Green Canyon, Arabian Light and Point Arguello. The oils were subjected to mixing at 5, 15 and 25 degrees C. Both Arabian Light and Point Arguello formed meso-stable emulsions at 15 degrees C and were examined further. Arabian Light had a relatively high viscosity, while Point Arguello had a low viscosity. The objective was to examine the effects of changing viscosity resulting from changes in temperature on oil at either end of the observed viscosity window. The total energy applied to the oil/water in the emulsion formation apparatus was varied from about 50 to 600,000 ergs. Work was varied from 1 to 5123 Joules per second. It was determined that a minimum energy threshold is needed for most emulsion formation, but only work correlates with the stability value. The emulsions formed at lower temperatures exhibited higher stability than would be expected from the increase in viscosity. This is most likely because the increase was insufficient, in the case of Green Canyon oil, to result in the formation of emulsions. It was concluded that the stabiemulsions. It was concluded that the stability of an emulsion formed from a given oil increases with decreasing formation temperature. The apparent viscosity is higher at the lower temperature. The work was found to correlate most closely with the stability of the emulsion or water-in-oil state. 7 refs., 4 tabs., 6 figs

  11. Expression and functional characterization of four aquaporin water channels from the European eel (Anguilla anguilla)

    OpenAIRE

    Maciver, Bryce; Cutler, Christopher P.; Yin, Jia; Hill, Myles G.; Zeidel, Mark L.; Hill, Warren G.

    2009-01-01

    The European eel is a euryhaline teleost which has been shown to differentially up- and downregulate aquaporin (AQP) water channels in response to changes in environmental salinity. We have characterized the transport properties of four aquaporins localized to osmoregulatory organs – gill, esophagus, intestine and kidney. By sequence comparison these four AQP orthologs resemble human AQP1 (eel AQP1), AQP3 (eel AQP3) and AQP10 (AQPe). The fourth member is a duplicate ...

  12. Water extract of the fungi from Fuzhuan brick tea improves the beneficial function on inhibiting fat deposition.

    Science.gov (United States)

    Peng, Yuxuan; Xiong, Zhe; Li, Juan; Huang, Jian-An; Teng, Cuiqin; Gong, Yushun; Liu, Zhonghua

    2014-08-01

    Fuzhuan brick tea (FBT) is traditionally consumed by the ethnic group in the border region of northwest China. The unique yellow fungal (Eurotium cristatum) growth phase is considered to be the key process point in the manufacture of the brick tea. The fungi from FBT are not only strongly correlated to the quality of brick tea, but also have the potential function of preventing obesity. The water extract of fungi (100??g/mL) can significantly inhibit fat deposition in 3T3-L1 adipocyte and Caenorhabditis elegans. Furthermore, the inhibition of 3T3-L1 adipocyte formation was not due to the suppression on cell viability. PMID:24634994

  13. Radioactive probe studies of coordination modes of heavy metal ions from natural waters to functionalized magnetic nanoparticles

    CERN Multimedia

    Carvalho soares, J; Lopes, C; Araujo, J

    We propose to use PAC, Perturbed Angular Correlations, to study the local environment of ionic species (Hg$^{2+}$, Cd$^{2+}$) coordinated on functionalized magnetic nanoparticles. Studies include the analysis of different nanoparticles sizes (30-100nm), and the monitoring of time/steps dependence of the coordination of those cations at the nanoparticles surfaces. Combined with theoretical calculations, the obtained data will support the understanding of local coordination modes, which is essential to help to improve methods of magnetically assisted separation of such hazardous contaminants from water.

  14. Displaced squeezed number states: Position space representation, inner product, and some applications

    OpenAIRE

    Møller, Klaus Braagaard; Jørgensen, Thomas Godsk; Dahl, Jens Peder

    2006-01-01

    For some applications the overall phase of a quantum state is crucial. For the so-called displaced squeezed number state (DSN), which is a generalization of the well-known squeezed coherent state, we obtain the position space representation with the correct overall phase, from the dynamics in a harmonic potential. The importance of the overall phase is demonstrated in the context of characteristic or moment generating functions. For two special cases the characteristic function is shown to be...

  15. Variation in functional rooting depth and soil water partitioning along an elevational gradient in the southwestern U.S

    Science.gov (United States)

    Guo, J.; Hungate, B. A.; Kolb, T.; KOCH, G. W.

    2012-12-01

    In semi-arid environments, co-existing plant species may vary in rooting depth, reflecting functional differences in water sources. In mountains of the southwestern U.S., moisture availability increases with elevation and winter and summer precipitation inputs differ isotopically. Examining variation in functional rooting depth among different plant communities and seasons is important to understanding how these communities may respond to the predicted warming and drying of the Southwest. The goal of this study was to assess the water partitioning of the woody plant community along an elevational moisture gradient using water isotopes as a proxy for rooting depth. We hypothesized that spatial and temporal water partitioning would be greatest in low elevation, moisture-stressed sites and would decrease as moisture availability increases with elevation. Five plots were established in each of five biotic communities: upland Sonoran desert, pinyon-juniper woodland, ponderosa pine forest, mixed-conifer forest, and spruce-fir forest. Soils (surface, 20 cm, 40 cm) and stem samples of dominant woody perennials were sampled during the late spring dry season and in late summer following monsoon rains, water was extracted using a cryo-vacuum line, and ?D and ?18O values were determined by off-axis cavity ringdown spectroscopy. Soil moisture content increased with elevation across all sites and increased with soil depth in the desert, pinyon-juniper, and ponderosa sites. The ?D values differed significantly among species in the desert and the ponderosa forest communities (p=0.014 and 0.039 ), while no species differences in ?D were found in the pinyon-juniper woodland or mixed-conifer forest. With the exception of the pinyon-juniper woodland, these data support our hypothesis that niche differentiation between species becomes less significant higher on the topographic moisture gradient, in the mixed-conifer forest. While spatial water partitioning mostly follows our predictions during the late spring, the lack of differentiation between species in the pinyon-juniper woodland indicates that temporal partitioning may be key to species coexistence in this system.

  16. Why cold water delays the onset of vestibular vertigo-An functional MRI study

    International Nuclear Information System (INIS)

    The mechanism of vertigo is unclear. Generally, the peak time or the latency of blood oxygenation level dependent (BOLD) effect is about 6 s. However, clinically, the latency of vertigo or nystagmus induced by caloric stimulations is much longer than 6 s, commonly about 30 s induced by water of 30 deg. C or 44 deg. C. We hypothesize that there is an inhibitive power or mechanism for the occurrence of vestibular vertigo, since it is an unpleasant feeling. The caloric test was performed in healthy volunteers during the BOLD fMRI scanning. The overlaid results of statistical parametric mapping (SPM) showed that three brain regions showed neural activation during vestibular dizziness while deactivation occurred in response to cold water simulation: (1) supplementary motor area (SMA); (2) middle temporal area/medial superior temporal area (MT/MST); (3) visual association area (BA19). The time course of the regions further demonstrated that the signal decreased during the cold-water stimulation and increased during the period of vertigo. We therefore further hypothesize that there may be two forces for the production of vertigo: inhibitory power (IP) and promotive power (PP). The delayed onset of vertigo was the result of the interaction between IP and PP. All of our findings, for the first time, suggested such an original mechanism of vertigo

  17. Why cold water delays the onset of vestibular vertigo-An functional MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhi [Department of Radiology, Beijing Hospital, No. 1 Dahua Road Dongdan, Beijing 100730 (China)], E-mail: zhiwang76@gmail.com; Chen Min [Department of Radiology, Beijing Hospital, No. 1 Dahua Road Dongdan, Beijing 100730 (China); Gong Xia; Huang Weining [Department of E.N.T., Beijing Hospital, No. 1 Dahua Road Dongdan, Beijing 100730 (China); Xu Liang [Department of Radiology, Beijing Hospital, No. 1 Dahua Road Dongdan, Beijing 100730 (China); Zhou Cheng [Department of Radiology, Beijing Hospital, No. 1 Dahua Road Dongdan, Beijing 100730 (China)], E-mail: chengzhou2000@yahoo.com

    2008-09-15

    The mechanism of vertigo is unclear. Generally, the peak time or the latency of blood oxygenation level dependent (BOLD) effect is about 6 s. However, clinically, the latency of vertigo or nystagmus induced by caloric stimulations is much longer than 6 s, commonly about 30 s induced by water of 30 deg. C or 44 deg. C. We hypothesize that there is an inhibitive power or mechanism for the occurrence of vestibular vertigo, since it is an unpleasant feeling. The caloric test was performed in healthy volunteers during the BOLD fMRI scanning. The overlaid results of statistical parametric mapping (SPM) showed that three brain regions showed neural activation during vestibular dizziness while deactivation occurred in response to cold water simulation: (1) supplementary motor area (SMA); (2) middle temporal area/medial superior temporal area (MT/MST); (3) visual association area (BA19). The time course of the regions further demonstrated that the signal decreased during the cold-water stimulation and increased during the period of vertigo. We therefore further hypothesize that there may be two forces for the production of vertigo: inhibitory power (IP) and promotive power (PP). The delayed onset of vertigo was the result of the interaction between IP and PP. All of our findings, for the first time, suggested such an original mechanism of vertigo.

  18. Photosynthetic metabolism and quality of Eugenia pyriformis Cambess. seedlings on substrate function and water levels

    Scientific Electronic Library Online (English)

    SILVANA P.Q., SCALON; TATIANE S., JEROMINI; ROSILDA M., MUSSURY; DAIANE M., DRESCH.

    2014-12-01

    Full Text Available Objetivou-se no presente trabalho avaliar a qualidade e o metabolismo fotossintético das mudas de uvaia (Eugenia pyriformis Cambess.) em diferentes substratos e regimes hídricos. A semeadura foi realizada em tubetes de 50 x 190 mm nos seguintes substratos: Areia (A), Latossolo + areia (L + A) (1:1), [...] Latossolo + areia + cama de frango semidecomposta (L + A1 + CF) (1:1:0,5), Latossolo + areia + cama de frango semidecomposta (L + A2 + CF) (1:2:0,5), Latossolo + Bioplant® (L + B) (1:1) e os níveis de irrigação avaliados foram 50, 75 e 100% da capacidade de retenção de água. Aos 60, 90, 120 e 150 dias de idade as mudas foram avaliadas quanto ao índice de clorofila; a área foliar (cm2) e o índice de qualidade de Dickson (IQD) e aos 150 dias de idade foram avaliadas a concentração interna de carbono (mol m–2 s–1), condutância estomática (mol m–2 s–1), taxa de transpiração (mmol m–2 s–1), fotossíntese (µmol m–2 s–1) e eficiência no uso da água (µmol de CO2 / mmol de H2O). Até os 150 dias de idade, as mudas apresentaram maior qualidade e metabolismo fotossintético quando cultivadas com substratos contendo Latossolo + areia + cama de frango nas duas variações avaliadas e na capacidade de retenção de água de 50 %. Abstract in english The aim of this research was to evaluate the quality and photosynthetic metabolism of “uvaia” seedlings (Eugenia pyriformis Cambess.) on different substrates and water regimes. The seeds were sown in tubes of 50 x 190 mm in the following substrates: Sand (S), Latosol + Sand (L + S) (1:1), Latosol + [...] Sand + Semi Decomposed Poultry Litter (L + S1 + PL) ( 1:1:0.5), Latosol + Sand + Semi Decomposed Poultry Litter (L + S2 + PL) (1:2:0.5), Latosol + Bioplant® (L + B) (1:1), and the water levels assessed were 50, 75 and 100% of water retention capacity. At 60, 90, 120 and 150 days the seedlings were evaluated according to their chlorophyll index, leaf area (cm2) and Dickson Quality Index (DQI) and at 150 days their internal concentration of carbon (mol m–2 s–1), stomatal conductance (mol m–2 s–1), transpiration rate (mmol m–2 s–1), photosynthesis (µmol m–2 s–1) and efficiency of water use (µmol de CO2 / mmol de H2O). Until their 150th days, the seedlings had higher quality and photosynthetic metabolism when cultured with substrates containing latosol + sand + poultry litter on the two variations assessed and water retention capacity of 50%.

  19. Functional issues and environmental qualification of digital protection systems of advanced light-water nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Korsah, K.; Clark, R.L.; Wood, R.T. [Oak Ridge National Lab., TN (United States)

    1994-04-01

    Issues of obsolescence and lack of infrastructural support in (analog) spare parts, coupled with the potential benefits of digital systems, are driving the nuclear industry to retrofit analog instrumentation and control (I&C) systems with digital and microprocessor-based systems. While these technologies have several advantages, their application to safety-related systems in nuclear power plants raises key issues relating to the systems` environmental qualification and functional reliability. To bound the problem of new I&C system functionality and qualification, the authors focused this study on protection systems proposed for use in ALWRs. Specifically, both functional and environmental qualification issues for ALWR protection system I&C were addressed by developing an environmental, functional, and aging data template for a protection division of each proposed ALWR design. By using information provided by manufacturers, environmental conditions and stressors to which I&C equipment in reactor protection divisions may be subjected were identified. The resulting data were then compared to a similar template for an instrument string typically found in an analog protection division of a present-day nuclear power plant. The authors also identified fiber-optic transmission systems as technologies that are relatively new to the nuclear power plant environment and examined the failure modes and age-related degradation mechanisms of fiber-optic components and systems. One reason for the exercise of caution in the introduction of software into safety-critical systems is the potential for common-cause failure due to the software. This study, however, approaches the functionality problem from a systems point of view. System malfunction scenarios are postulated to illustrate the fact that, when dealing with the performance of the overall integrated system, the real issues are functionality and fault tolerance, not hardware vs. software.

  20. Functional issues and environmental qualification of digital protection systems of advanced light-water nuclear reactors

    International Nuclear Information System (INIS)

    Issues of obsolescence and lack of infrastructural support in (analog) spare parts, coupled with the potential benefits of digital systems, are driving the nuclear industry to retrofit analog instrumentation and control (I ampersand C) systems with digital and microprocessor-based systems. While these technologies have several advantages, their application to safety-related systems in nuclear power plants raises key issues relating to the systems' environmental qualification and functional reliability. To bound the problem of new I ampersand C system functionality and qualification, the authors focused this study on protection systems proposed for use in ALWRs. Specifically, both functional and environmental qualification issues for ALWR protection system I ampersand C were addressed by developing an environmental, functional, and aging data template for a protection division of each proposed ALWR design. By using information provided by manufacturers, environmental conditions and stressors to which I ampersand C equipment in reactor protection divisions may be subjected were identified. The resulting data were then compared to a similar template for an instrument string typically found in an analog protection division of a present-day nuclear power plant. The authors also identified fiber-optic transmission systems as technologies that are relatively new to the nuclear power plant environment and examined the failure modes and age-related degradation mechanisms of fiber-optic components and systems. One reason for the exercise of caution in the introduction of software into safety-critical systems is the potential for common-cause failure due to the software. This study, however, approaches the functionality problem from a systems point of view. System malfunction scenarios are postulated to illustrate the fact that, when dealing with the performance of the overall integrated system, the real issues are functionality and fault tolerance, not hardware vs. software

  1. What makes zeolitic imidazolate frameworks hydrophobic or hydrophilic? The impact of geometry and functionalization on water adsorption.

    Science.gov (United States)

    Ortiz, Aurélie U; Freitas, Alexy P; Boutin, Anne; Fuchs, Alain H; Coudert, François-Xavier

    2014-06-01

    We demonstrate, by means of Grand Canonical Monte Carlo simulation on different members of the ZIF family, how topology, geometry, and linker functionalization drastically affect the water adsorption properties of these materials, tweaking the ZIF materials from hydrophobic to hydrophilic. We show that adequate functionalization of the linkers allows one to tune the host-guest interactions, even featuring dual amphiphilic materials whose pore space features both hydrophobic and hydrophilic regions. Starting from an initially hydrophobic material (ZIF-8), various degrees of hydrophilicity could be obtained, with a gradual evolution from a type V adsorption isotherm in the liquid phase to a type I isotherm in the gas phase. This behavior is similar to what was described earlier in families of hydrophobic all-silica zeolites, with hydrophilic "defects" of various strength, such as silanol nests or the presence of extra-framework cations. PMID:24445495

  2. A Systematic Study of Chloride Ion Solvation in Water using van der Waals Inclusive Hybrid Density Functional Theory

    CERN Document Server

    Bankura, Arindam; DiStasio, Robert A; Swartz, Charles W; Klein, Michael L; Wu, Xifan

    2015-01-01

    In this work, the solvation and electronic structure of the aqueous chloride ion solution was investigated using Density Functional Theory (DFT) based \\textit{ab initio} molecular dynamics (AIMD). From an analysis of radial distribution functions, coordination numbers, and solvation structures, we found that exact exchange ($E_{\\rm xx}$) and non-local van der Waals (vdW) interactions effectively \\textit{weaken} the interactions between the Cl$^-$ ion and the first solvation shell. With a Cl-O coordination number in excellent agreement with experiment, we found that most configurations generated with vdW-inclusive hybrid DFT exhibit 6-fold coordinated distorted trigonal prism structures, which is indicative of a significantly disordered first solvation shell. By performing a series of band structure calculations on configurations generated from AIMD simulations with varying DFT potentials, we found that the solvated ion orbital energy levels (unlike the band structure of liquid water) strongly depend on the un...

  3. Synthesis and design of functionalized magnetic nanocolloids for water pollution remediation

    Science.gov (United States)

    Campos, A. F. C.; Ferreira, M. A.; Marinho, E. P.; Tourinho, F. A.; Depeyrot, J.

    This work focus on the potential applications of magnetic nanoparticles on pollution remediation. We draw attention to the chemical design of functionalized magnetic colloids based on tartrate ligands to be used in magnetic separation of heavy metals from wastewater. Coupling the speciation diagrams of nanoferrites particles surface with that of the tartaric acid, it was possible to provide a theoretical prediction of the optimal pH for particle surface-ligand complexation. Finally, from an electrochemical approach based on simultaneous potentiometric and conductimetric titrations it was possible to determine the saturation value of the surface charge density of the functionalized nanoparticles and its pH dependence.

  4. Displacements Prediction in Double-Arch Dam Rock Abutment Using SPSS Software Based on Extensometer Readings Case study: Karun 4 Concrete Dam, Iran

    Directory of Open Access Journals (Sweden)

    Hadi kamali Bandpey

    2012-11-01

    Full Text Available In this study we present a method for Displacements Prediction in Double-Arch Dam Rock Abutment Using SPSS Software Based on Extensometer Readings. Displacement in dams is the most tangible and important parameter which could be crucial in their safety. Different elevation displacements are yielded by various loadings and the thrust force imposed on foundation and abutment. Most concrete dams are constructed on stone foundations. Displacements in foundation and abutment are measured by extensometers. Karun 4 Concrete dam is designed with 11 galleries, from elevation 1016 to 802 m, in the order from top elevation (dam crest elevation 1032 to the bottom elevation (dam foundation elevation 806 within the dam body. As a whole, 19 extensometers in the left bank, 17 in the right, and one more in the middle are implemented in the dam. Karun 4 dam has already been impounded with water up to the elevation 1003. Displacements in Karun 4 are recorded by extensometers whence water was leveled in 7 elevations 943.68, 953.36, 973.55, 983.28, 993.17, 1003.13. In this study, using SPSS we have tried to predict the displacements for a situation in which water will be elevated to the elevations 1013, 1023, 1032 in the future for elevations which are equipped with anchor. The most predicted displacement pertaining to the left bank when water was leveled to the elevation 1013, was 3.65 mms by R2 = 0.9997 for the implemented anchor. Proceeding further, as water is leveled to the elevations 1023 and 1033, the most predicted displacement respectively would be 4.31 and 5.66 by R2 = 0.9941; and is related to the anchor implemented in the elevation 936.05. The most predicted displacement for the right bank is 5.9397, 7.2347 and 8.6877 mms by R2 = 0.9995 for the elevation 888.128 m.

  5. Long-term functionality of rural water services in developing countries: a system dynamics approach to understanding the dynamic interaction of factors.

    Science.gov (United States)

    Walters, Jeffrey P; Javernick-Will, Amy N

    2015-04-21

    Research has shown that sustainability of rural water infrastructure in developing countries is largely affected by the dynamic and systemic interactions of technical, social, financial, institutional, and environmental factors that can lead to premature water system failure. This research employs system dynamics modeling, which uses feedback mechanisms to understand how these factors interact dynamically to influence long-term rural water system functionality. To do this, the research first identified and aggregated key factors from the literature, then asked water sector experts to indicate the polarity and strength between factors through Delphi and cross impact survey questionnaires, and finally used system dynamics modeling to identify and prioritize feedback mechanisms. The resulting model identified 101 feedback mechanisms that were dominated primarily by three- and four-factor mechanisms that contained some combination of the factors: Water System Functionality, Community, Financial, Government, Management, and Technology, implying these factors were the most influential on long-term functionality. These feedback mechanisms were then scored and prioritized, with the most dominant feedback mechanism identified as Water System Functionality-Community-Finance-Management. This study showcases a way for practitioners to better understand the complexities inherent in rural water development using expert opinion and indicates the need for future research in rural water service sustainability that investigates the dynamic interaction of factors in different contexts. PMID:25775082

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

    Directory of Open Access Journals (Sweden)

    I. Núñez-Riboni

    2012-02-01

    Full Text Available Observations since the 1950s show a multi-decadal cycle of a meridional displacement of the Subpolar Front (SPF in the Newfoundland Basin (NFB in the North Atlantic. The SPF displacement is associated with corresponding variations in the path of the North Atlantic Current. We use the ocean general circulation model MPIOM with enhanced horizontal and vertical resolutions and forced with NCEP/NCAR reanalysis data to study the relation of the SPF displacement to atmospheric forcing, intensities of the subpolar gyre (SPG and Meridional Overturning Circulation (MOC, and Labrador Sea Water (LSW volume. The simulations indicate that the SPF displacement is associated with a circulation anomaly between the SPG and the subtropical gyre (STG, an inter-gyre gyre with a multi-decadal time scale. A sensitivity experiment indicates that both wind stress curl (WSC and heat fluxes (which match LSW changes contribute to the circulation anomalies in the frontal region and to the SPF displacement. An anticyclonic inter-gyre gyre is related to negative WSC and LSW anomalies and to a SPF north of its climatological position, indicating an expanding STG. A cyclonic inter-gyre gyre is related to positive WSC and LSW anomalies and a SPF south of its climatological position, indicating an expanding SPG. Therefore, the mean latitudinal position of the SPF in the NFB (a "SPF index" could be an indicator of the amount of LSW in the inter-gyre region. Spreading of LSW anomalies intensifies the MOC, suggesting our SPF index as predictor of the MOC intensity at multi-decadal time scales. The meridional displacement of the SPF has a pronounced influence on the meridional heat transport, both on its gyre and overturning components.

  7. Characteristics of acoustic emissions from fluid front displacement in porous media

    Science.gov (United States)

    Möbius, F.; Canone, D.; Or, D.

    2009-12-01

    Fluid displacement in porous media is of interest for environmental, petroleum and chemical engineering. Percolation theory and pore-scale models are useful in describing filling and emptying of pores and throats but fail to capture characteristics of the fast interfacial jumps and reconfigurations occurring during fluid displacement processes such as imbibitions and drainage. Energy release caused by these rapid events generates acoustic waves which propagate through the porous medium and can be detected at its surface using acoustic emission (AE) sensors. Through a series of experiment displacing various fluids through Hele-Shaw cells filled with glass beads of different sizes we investigate correlation between acoustic emission signals, fluid and pore space properties, and energy dissipation. Acoustic emission signals were quantified by considering number of hits (events) and amplitudes. The exponent of power law relating these characteristic values varied with the displacement process and pore size. The number of AE events and amplitudes dropped with decreasing liquid surface tension for displacement within the same porous medium (water, ethanol, silicon oil). Similar trends were observed with increasing liquid viscosity, only a few hits are recorded for silicon oil with 10 mPas. The results are interpreted considering air or liquid entry pressures into the pore spaces, with increasing pressure entries for small pores and liquid with higher surface tension. The viscosity plays an important role in restraining AE-producing jump events and dumping interfacial oscillations as could be shown theoretically for simple capillaries. The study establishes direct relationships between measured AE fluid and pore properties and offer potential for quantifying energy dissipation during fluid displacement in porous media as well as other transient flow characteristics using non invasive AE signals.

  8. Effects of switching functions on the behavior of liquid water in molecular dynamics simulations

    International Nuclear Information System (INIS)

    At 300 K, abrupt and switched cutoff methods are compared to the Ewald summation method. The switching method reduces the self-diffusion coefficient, makes the liquid more ordered, and strengthens the intermolecular interactions due to a fictitious retarding force introduced by the switching function. 62 refs., 4 figs., 3 tabs

  9. Percolation Line, Response Functions, and Voronoi Polyhedra Analysis in Supercritical Water.

    Czech Academy of Sciences Publication Activity Database

    Škvor, J.; Nezbeda, Ivo

    2012-01-01

    Ro?. 15, ?. 2 (2012), s. 23301. ISSN 1607-324X R&D Projects: GA AV ?R IAA200760905 Grant ostatní: GA UJEP(CZ) 53223–15–0010–01 Institutional support: RVO:67985858 Keywords : percolation line * response functions * widom lines Subject RIV: BJ - Thermodynamics Impact factor: 0.757, year: 2012

  10. Variable reluctance displacement transducer temperature compensated to 6500F

    International Nuclear Information System (INIS)

    In pressurized water reactor tests, compact instruments for accurate measurement of small displacements in a 6500F environment are often required. In the case of blowdown tests such as the Loss of Fluid Test (LOFT) or Semiscale computer code development tests, not only is the initial environment water at 6500F and 2200 psi but it undergoes a severe transient due to depressurization. Since the LOFT and Semiscale tests are run just for the purpose of obtaining data during the depressurization, instruments used to obtain the data must not give false outputs induced by the change in environment. A LOFT rho v2 probe and a Semiscale drag disk are described. Each utilizes a variable reluctance transducer (VRT) for indication of the drag-disk location and a torsion bar for drag-disk restoring force. The VRT, in addition to being thermally gain and null offset stable, is fabricated from materials known to be resistant to large nuclear radiation levels and has successfully passed a fast neutron radiation test of 2.7 x 1017 nvt without failure

  11. Water Oxidation by a Cytochrome P450: Mechanism and Function of the Reaction

    Science.gov (United States)

    Prasad, Brinda; Mah, Derrick J.; Lewis, Andrew R.; Plettner, Erika

    2013-01-01

    P450cam (CYP101A1) is a bacterial monooxygenase that is known to catalyze the oxidation of camphor, the first committed step in camphor degradation, with simultaneous reduction of oxygen (O2). We report that P450cam catalysis is controlled by oxygen levels: at high O2 concentration, P450cam catalyzes the known oxidation reaction, whereas at low O2 concentration the enzyme catalyzes the reduction of camphor to borneol. We confirmed, using 17O and 2H NMR, that the hydrogen atom added to camphor comes from water, which is oxidized to hydrogen peroxide (H2O2). This is the first time a cytochrome P450 has been observed to catalyze oxidation of water to H2O2, a difficult reaction to catalyze due to its high barrier. The reduction of camphor and simultaneous oxidation of water are likely catalyzed by the iron-oxo intermediate of P450cam, and we present a plausible mechanism that accounts for the 1?1 borneol:H2O2 stoichiometry we observed. This reaction has an adaptive value to bacteria that express this camphor catabolism pathway, which requires O2, for two reasons: 1) the borneol and H2O2 mixture generated is toxic to other bacteria and 2) borneol down-regulates the expression of P450cam and its electron transfer partners. Since the reaction described here only occurs under low O2 conditions, the down-regulation only occurs when O2 is scarce. PMID:23634216

  12. Atypical water lattices and their possible relevance to the amorphous ices: A density functional study

    OpenAIRE

    Anick, David J.

    2013-01-01

    Of the fifteen known crystalline forms of ice, eleven consist of a single topologically connected hydrogen bond network with four H-bonds at every O. The other four, Ices VI–VIII and XV, consist of two topologically connected networks, each with four H-bonds at every O. The networks interpenetrate but do not share H-bonds. This article presents two new periodic water lattice families whose topological connectivity is “atypical”: they consist of many two-dimensional layers that share no ...

  13. Automatic Alignment of Displacement-Measuring Interferometer

    Science.gov (United States)

    Halverson, Peter; Regehr, Martin; Spero, Robert; Alvarez-Salazar, Oscar; Loya, Frank; Logan, Jennifer

    2006-01-01

    A control system strives to maintain the correct alignment of a laser beam in an interferometer dedicated to measuring the displacement or distance between two fiducial corner-cube reflectors. The correct alignment of the laser beam is parallel to the line between the corner points of the corner-cube reflectors: Any deviation from parallelism changes the length of the optical path between the reflectors, thereby introducing a displacement or distance measurement error. On the basis of the geometrical optics of corner-cube reflectors, the length of the optical path can be shown to be L = L(sub 0)cos theta, where L(sub 0) is the distance between the corner points and theta is the misalignment angle. Therefore, the measurement error is given by DeltaL = L(sub 0)(cos theta - 1). In the usual case in which the misalignment is small, this error can be approximated as DeltaL approximately equal to -L(sub 0)theta sup 2/2. The control system (see figure) is implemented partly in hardware and partly in software. The control system includes three piezoelectric actuators for rapid, fine adjustment of the direction of the laser beam. The voltages applied to the piezoelectric actuators include components designed to scan the beam in a circular pattern so that the beam traces out a narrow cone (60 microradians wide in the initial application) about the direction in which it is nominally aimed. This scan is performed at a frequency (2.5 Hz in the initial application) well below the resonance frequency of any vibration of the interferometer. The laser beam makes a round trip to both corner-cube reflectors and then interferes with the launched beam. The interference is detected on a photodiode. The length of the optical path is measured by a heterodyne technique: A 100- kHz frequency shift between the launched beam and a reference beam imposes, on the detected signal, an interferometric phase shift proportional to the length of the optical path. A phase meter comprising analog filters and specialized digital circuitry converts the phase shift to an indication of displacement, generating a digital signal proportional to the path length.

  14. Statistical theory of X-ray scattering from crystals of finite size with pure displacement disorder in one dimension

    International Nuclear Information System (INIS)

    The statistical theory of X-ray scattering from a crystal that is disordered in one dimension is discussed. The state of disorder is characterized by probabilities that different types of scattering elements occupy specified positions. The effect this disorder has on the corresponding ensemble average axial reflections is determined. Finite size is explicitly accounted for. Motivated by recent experiments on water intercalation into thin, lyotropic multilayers, special consideration is given to systems whose components differ with respect to size, but not with respect to their scattering factors. Focusing on this case of pure displacement disorder in a binary mixture, a representation of the scattering function in closed form is derived. The case of a random binary mixture leads to the results of Hendricks and Teller, and Mering, while in the presence of nearest-neighbor correlations, a connection is established with the theory of Kakinoki and Komura. In extension of their treatment, systems with non-stationary transition probabilities are investigated. The effects on the scattering function of constraining composition fluctuations are also studied. Particular characteristics of the scattering function are displayed and discussed. (orig.)

  15. Enhanced sorption of mercury from compact fluorescent bulbs and contaminated water streams using functionalized multiwalled carbon nanotubes

    International Nuclear Information System (INIS)

    Highlights: • Oxidized (CNT-OX), CNT-I, CNT-S were prepared. • Capacity of CNT-S (151.5 mg/g) was higher than other CNTs. • Applied to the removal of Hg(II) from spiked and natural coal wash waters. • Applied to the removal of Hg(0) from compact fluorescent lamps. - Abstract: Three different functionalized multiwalled carbon nanotubes were prepared, namely, oxidized CNTs (CNT-OX), iodide incorporated MWCNT (CNT-I) and sulfur incorporated MWCNT (CNT-S). The as prepared adsorbents were structurally characterized by various spectral techniques like scanning electron microscopy (SEM), energy dispersive X-ray (EDAX), Brunauer, Emmett, and Teller (BET) surface area analyzer, Fourier transform infra red (FTIR) and Raman spectroscopy. Loading of iodide and sulfur was evident from the EDAX graphs. The adsorption properties of Hg2+ as a function of pH, contact time and initial metal concentration were characterized by Cold vapor AAS. The adsorption kinetics fitted the Pseudo second order kinetics and equilibrium was reached within 90 min. The experimental data were modeled with Langmuir, Freundlich, Dubinin-Redushkevich and Temkin isotherms and various isotherm parameters were evaluated. It was found that the mercury adsorption capacity for the prepared adsorbents were in the order of CNT-S > CNT-I > CNT-OX > CNT. Studies have been conducted to demonstrate the applicability of the sorbent toward the removal of Hg(0) from broken compact fluorescent light (CFL) bulbs and Hg(II) from contaminated water streams

  16. One-pot solvothermal synthesis of highly water-dispersible size-tunable functionalized magnetite nanocrystal clusters for lipase immobilization.

    Science.gov (United States)

    Zhu, Hao; Hou, Chen; Li, Yijing; Zhao, Guanghui; Liu, Xiao; Hou, Ke; Li, Yanfeng

    2013-07-01

    A facile one-pot synthesis of highly water-dispersible size-tunable magnetite (Fe3O4) nanocrystal clusters (MNCs) end-functionalized with amino or carboxyl groups by a modified solvothermal reduction reaction has been developed. Dopamine and 3,4-dihydroxyhydroxycinnamic acid were used for the first time as both a surfactant and interparticle linker in a polylol process for economical and environment-friendly purposes. Morphology, chemical composition, and magnetic properties of the prepared particles were investigated by several methods, including FESEM, TEM, XRD, XPS, Raman, FTIR, TGA, zeta potential, and VSM. The sizes of the particles could be easily tuned over a wide range from 175 to 500?nm by varying the surfactant concentration. Moreover, ethylene glycol/diethylene glycol (EG/DEG) solvent mixtures with different ratios could be used as reductants to obtain the particles with smaller sizes. The XRD data demonstrated that the surfactants restrained the crystal growth of the grains. The nanoparticles showed superior magnetic properties and high colloidal stability in water. The cytotoxicity results indicated the feasibility of using the synthesized nanocrystals in biology-related fields. To estimate the applicability of the obtained MNCs in biotechnology, Candida rugosa lipase was selected for the enzyme immobilization process. The immobilized lipase exhibited excellent thermal stability and reusability in comparison with the free enzyme. This novel strategy would simplify the reaction protocol and improve the efficiency of materials functionalization, thus offering new potential applications in biotechnology and organocatalysis. PMID:23616374

  17. Template-Free Synthesis of Functional 3D BN architecture for removal of dyes from water

    Science.gov (United States)

    Liu, Dan; Lei, Weiwei; Qin, Si; Chen, Ying

    2014-03-01

    Three-dimensional (3D) architectures are of interest in applications in electronics, catalysis devices, sensors and adsorption materials. However, it is still a challenge to fabricate 3D BN architectures by a simple method. Here, we report the direct synthesis of 3D BN architectures by a simple thermal treatment process. A 3D BN architecture consists of an interconnected flexible network of nanosheets. The typical nitrogen adsorption/desorption results demonstrate that the specific surface area for the as-prepared samples is up to 1156 m2 g-1, and the total pore volume is about 1.17 cm3 g-1. The 3D BN architecture displays very high adsorption rates and large capacities for organic dyes in water without any other additives due to its low densities, high resistance to oxidation, good chemical inertness and high surface area. Importantly, 88% of the starting adsorption capacity is maintained after 15 cycles. These results indicate that the 3D BN architecture is potential environmental materials for water purification and treatment.

  18. A Capacitive Displacement Sensing Technique for Early Detection of Unbalanced Loads in a Washing Machine

    OpenAIRE

    Karthik Tiruthani; Ramasubramanian, Melur K.

    2009-01-01

    Horizontal axis washing machines are water and energy efficient and becoming popular in the USA. Unlike a vertical axis washer, these do not have an agitator and depend solely on tumbling for the agitation of laundry during the wash cycle. However, due to the constant shifting of laundry during washing, the load distribution is often unbalanced during the high speed spin cycle. We present a displacement-based sensing method to detect unbalance early while the spin rate (rpm) is well below the...

  19. Pre-failure behaviour of an unstable limestone cliff from displacement and seismic data

    Directory of Open Access Journals (Sweden)

    J.-L. Got

    2010-04-01

    Full Text Available We monitored the displacement and seismic activity of an unstable vertical rock slice in a natural limestone cliff of the southeast Vercors massif, southeast France, during the months preceding its collapse. Displacement measurements showed an average acceleration of the movement of its top, with clear increases in the displacement velocity and in the discrete seismic event production rate during periods where temperature falls, with more activity when rainfall or frost occurs. Crises of discrete seismic events produce high amplitudes in periodograms, but do not change the high frequency base noise level rate. We infer that these crises express the critical crack growth induced by water weakening (from water vapor condensation or rain of the rock strength rather than to a rapid change in applied stresses. Seismic noise analysis showed a steady increase in the high frequency base noise level and the emergence of spectral modes in the signal recorded by the sensor installed on the unstable rock slice during the weeks preceding the collapse. High frequency seismic noise base level seems to represent subcritical crack growth. It is a smooth and robust parameter whose variations are related to generalized changes in the rupture process. Drop of the seismic noise amplitude was concomitant with the emergence of spectral modes – that are compatible with high-order eigenmodes of the unstable rock slice – during the later stages of its instability. Seismic noise analysis, especially high frequency base noise level analysis may complement that of inverse displacement velocity in early-warning approaches when strong displacement fluctuations occur.

  20. Calculation of Gamma Displacement Cross Sections: Generation of Recoil Spectra from ENDF/B-VII

    International Nuclear Information System (INIS)

    Radiation damage in materials is caused by the transfer of energy from an incident particle to the target atoms, which results in the redistribution of target atoms. During the nuclear reactor operation, various kinds of radiation are produced, including fast neutron, gamma, beta, high-energy ions etc. These radiations may affect the properties of reactor structural materials in a direct and/or indirect way. It is well known that fast neutrons have an effect on the degradation of materials. Whereas the impact of fast neutrons (En > 1 MeV) on material property changes is clearly recognized, the impact of gamma ray damage to materials is usually not significant. However, there has been some interest in gamma ray damage in metals in promoting accelerated embrittlement of reactor pressure vessel steels in the HFIR (High Flux Isotopes Reactor). In situations where there is a large water gap between pressure vessel and fuel assembly, gamma damage can become comparable to that produced by neutrons, on the basis of displacements per atom (dpa) parameter. A recent analysis of gamma ray displacement damage in the RPV of the General Electric Advanced Boiling Water Reactor (ABWR) indicated that the ratio of calculated gamma- to neutron-induced displacement damage rates is over 100% at the RPV inner diameter. Under a high gamma dose environment, embrittlement can be accelerated by radiation-enhanced mass transport mechanism. Because gamma rays are much more efficient than neutrons at producing freely-migrating defects, any radiation enhanced or induced processes that depend on the magnitude of defect fluxes to sinks, can be disproportionately affected by gamma. The direct evaluation of the contribution of gamma ray to damage in materials, quantified as a parameter of dpa, is made possible once the displacement damage cross section due to gamma rays are known. In this work, we present calculations for gamma ray displacement cross sections in various materials in the energy range from 0 to 14 MeV