High-resolution continuous-flow analysis setup for water isotopic measurement from ice cores using laser spectroscopy

NASA Astrophysics Data System (ADS)

Emanuelsson, B. D.; Baisden, W. T.; Bertler, N. A. N.; Keller, E. D.; Gkinis, V.

2015-07-01

Here we present an experimental setup for water stable isotope (δ18O and δD) continuous-flow measurements and provide metrics defining the performance of the setup during a major ice core measurement campaign (Roosevelt Island Climate Evolution; RICE). We also use the metrics to compare alternate systems. Our setup is the first continuous-flow laser spectroscopy system that is using off-axis integrated cavity output spectroscopy (OA-ICOS; analyzer manufactured by Los Gatos Research, LGR) in combination with an evaporation unit to continuously analyze water samples from an ice core. A Water Vapor Isotope Standard Source (WVISS) calibration unit, manufactured by LGR, was modified to (1) enable measurements on several water standards, (2) increase the temporal resolution by reducing the response time and (3) reduce the influence from memory effects. While this setup was designed for the continuous-flow analysis (CFA) of ice cores, it can also continuously analyze other liquid or vapor sources. The custom setups provide a shorter response time (~ 54 and 18 s for 2013 and 2014 setup, respectively) compared to the original WVISS unit (~ 62 s), which is an improvement in measurement resolution. Another improvement compared to the original WVISS is that the custom setups have a reduced memory effect. Stability tests comparing the custom and WVISS setups were performed and Allan deviations (σAllan) were calculated to determine precision at different averaging times. For the custom 2013 setup the precision after integration times of 103 s is 0.060 and 0.070 ‰ for δ18O and δD, respectively. The corresponding σAllan values for the custom 2014 setup are 0.030, 0.060 and 0.043 ‰ for δ18O, δD and δ17O, respectively. For the WVISS setup the precision is 0.035, 0.070 and 0.042 ‰ after 103 s for δ18O, δD and δ17O, respectively. Both the custom setups and WVISS setup are influenced by instrumental drift with δ18O being more drift sensitive than δD. The σAllan values for δ18O are 0.30 and 0.18 ‰ for the custom 2013 and WVISS setup, respectively, after averaging times of 104 s (2.78 h). Using response time tests and stability tests, we show that the custom setups are more responsive (shorter response time), whereas the University of Copenhagen (UC) setup is more stable. More broadly, comparisons of different setups address the challenge of integrating vaporizer/spectrometer isotope measurement systems into a CFA campaign with many other analytical instruments.

A Non-Equilibrium Sediment Transport Model for Coastal Inlets and Navigation Channels

DTIC Science & Technology

2011-01-01

exchange of water , sediment, and nutrients between estuaries and the ocean. Because of the multiple interacting forces (waves, wind, tide, river...in parallel using OpenMP. The CMS takes advantage of the Surface- water Modeling System (SMS) interface for grid generation and model setup, as well...as for plotting and post- processing (Zundel, 2000). The circulation model in the CMS (called CMS-Flow) computes the unsteady water level and

Levels at gaging stations

USGS Publications Warehouse

Kenney, Terry A.

2010-01-01

Operational procedures at U.S. Geological Survey gaging stations include periodic leveling checks to ensure that gages are accurately set to the established gage datum. Differential leveling techniques are used to determine elevations for reference marks, reference points, all gages, and the water surface. The techniques presented in this manual provide guidance on instruments and methods that ensure gaging-station levels are run to both a high precision and accuracy. Levels are run at gaging stations whenever differences in gage readings are unresolved, stations may have been damaged, or according to a pre-determined frequency. Engineer's levels, both optical levels and electronic digital levels, are commonly used for gaging-station levels. Collimation tests should be run at least once a week for any week that levels are run, and the absolute value of the collimation error cannot exceed 0.003 foot/100 feet (ft). An acceptable set of gaging-station levels consists of a minimum of two foresights, each from a different instrument height, taken on at least two independent reference marks, all reference points, all gages, and the water surface. The initial instrument height is determined from another independent reference mark, known as the origin, or base reference mark. The absolute value of the closure error of a leveling circuit must be less than or equal to ft, where n is the total number of instrument setups, and may not exceed |0.015| ft regardless of the number of instrument setups. Closure error for a leveling circuit is distributed by instrument setup and adjusted elevations are determined. Side shots in a level circuit are assessed by examining the differences between the adjusted first and second elevations for each objective point in the circuit. The absolute value of these differences must be less than or equal to 0.005 ft. Final elevations for objective points are determined by averaging the valid adjusted first and second elevations. If final elevations indicate that the reference gage is off by |0.015| ft or more, it must be reset.

On the use of wave parameterizations and a storm impact scaling model in National Weather Service Coastal Flood and decision support operations

USGS Publications Warehouse

Mignone, Anthony; Stockdon, H.; Willis, M.; Cannon, J.W.; Thompson, R.

2012-01-01

National Weather Service (NWS) Weather Forecast Offices (WFO) are responsible for issuing coastal flood watches, warnings, advisories, and local statements to alert decision makers and the general public when rising water levels may lead to coastal impacts such as inundation, erosion, and wave battery. Both extratropical and tropical cyclones can generate the prerequisite rise in water level to set the stage for a coastal impact event. Forecasters use a variety of tools including computer model guidance and local studies to help predict the potential severity of coastal flooding. However, a key missing component has been the incorporation of the effects of waves in the prediction of total water level and the associated coastal impacts. Several recent studies have demonstrated the importance of incorporating wave action into the NWS coastal flood program. To follow up on these studies, this paper looks at the potential of applying recently developed empirical parameterizations of wave setup, swash, and runup to the NWS forecast process. Additionally, the wave parameterizations are incorporated into a storm impact scaling model that compares extreme water levels to beach elevation data to determine the mode of coastal change at predetermined “hotspots” of interest. Specifically, the storm impact model compares the approximate storm-induced still water level, which includes contributions from tides, storm surge, and wave setup, to dune crest elevation to determine inundation potential. The model also compares the combined effects of tides, storm surge, and the 2 % exceedance level for vertical wave runup (including both wave setup and swash) to dune toe and crest elevations to determine if erosion and/or ocean overwash may occur. The wave parameterizations and storm impact model are applied to two cases in 2009 that led to significant coastal impacts and unique forecast challenges in North Carolina: the extratropical “Nor'Ida” event during 11-14 November and the large swell event from distant Hurricane Bill on 22 August. The coastal impacts associated with Nor'Ida were due to the combined effects of surge, tide, and wave processes and led to an estimated 5.8 million dollars in damage. While the impacts from Hurricane Bill were not as severe as Nor'Ida, they were mainly associated with wave processes. Thus, this event exemplifies the importance of incorporating waves into the total water level and coastal impact prediction process. These examples set the stage for potential future applications including adaption to the more complex topography along the New England coast.

The characteristics and dynamics of wave-driven flow across a platform coral reef in the Red Sea

NASA Astrophysics Data System (ADS)

Lentz, S. J.; Churchill, J. H.; Davis, K. A.; Farrar, J. T.; Pineda, J.; Starczak, V.

2016-02-01

Current dynamics across a platform reef in the Red Sea near Jeddah, Saudi Arabia, are examined using 18 months of current profile, pressure, surface wave, and wind observations. The platform reef is 700 m long, 200 m across with spatial and temporal variations in water depth over the reef ranging from 0.6 to 1.6 m. Surface waves breaking at the seaward edge of the reef cause a 2-10 cm setup of sea level that drives cross-reef currents of 5-20 cm s-1. Bottom stress is a significant component of the wave setup balance in the surf zone. Over the reef flat, where waves are not breaking, the cross-reef pressure gradient associated with wave setup is balanced by bottom stress. The quadratic drag coefficient for the depth-average flow decreases with increasing water depth from Cda = 0.17 in 0.4 m of water to Cda = 0.03 in 1.2 m of water. The observed dependence of the drag coefficient on water depth is consistent with open-channel flow theory and a hydrodynamic roughness of zo = 0.06 m. A simple one-dimensional model driven by incident surface waves and wind stress accurately reproduces the observed depth-averaged cross-reef currents and a portion of the weaker along-reef currents over the focus reef and two other Red Sea platform reefs. The model indicates the cross-reef current is wave forced and the along-reef current is partially wind forced.

An alternative cost-effective image processing based sensor for continuous turbidity monitoring

NASA Astrophysics Data System (ADS)

Chai, Matthew Min Enn; Ng, Sing Muk; Chua, Hong Siang

2017-03-01

Turbidity is the degree to which the optical clarity of water is reduced by impurities in the water. High turbidity values in rivers and lakes promote the growth of pathogen, reduce dissolved oxygen levels and reduce light penetration. The conventional ways of on-site turbidity measurements involve the use of optical sensors similar to those used in commercial turbidimeters. However, these instruments require frequent maintenance due to biological fouling on the sensors. Thus, image processing was proposed as an alternative technique for continuous turbidity measurement to reduce frequency of maintenance. The camera was kept out of water to avoid biofouling while other parts of the system submerged in water can be coated with anti-fouling surface. The setup developed consisting of a webcam, a light source, a microprocessor and a motor used to control the depth of a reference object. The image processing algorithm quantifies the relationship between the number of circles detected on the reference object and the depth of the reference object. By relating the quantified data to turbidity, the setup was able to detect turbidity levels from 20 NTU to 380 NTU with measurement error of 15.7 percent. The repeatability and sensitivity of the turbidity measurement was found to be satisfactory.

Sele coastal plain flood risk due to wave storm and river flow interaction

NASA Astrophysics Data System (ADS)

Benassai, Guido; Aucelli, Pietro; Di Paola, Gianluigi; Della Morte, Renata; Cozzolino, Luca; Rizzo, Angela

2016-04-01

Wind waves, elevated water levels and river discharge can cause flooding in low-lying coastal areas, where the water level is the interaction between wave storm elevated water levels and river flow interaction. The factors driving the potential flood risk include weather conditions, river water stage and storm surge. These data are required to obtain inputs to run the hydrological model used to evaluate the water surface level during ordinary and extreme events regarding both the fluvial overflow and storm surge at the river mouth. In this paper we studied the interaction between the sea level variation and the river hydraulics in order to assess the location of the river floods in the Sele coastal plain. The wave data were acquired from the wave buoy of Ponza, while the water level data needed to assess the sea level variation were recorded by the tide gauge of Salerno. The water stages, river discharges and rating curves for Sele river were provided by Italian Hydrographic Service (Servizio Idrografico e Mareografico Nazionale, SIMN).We used the dataset of Albanella station (40°29'34.30"N, 15°00'44.30"E), located around 7 km from the river mouth. The extreme river discharges were evaluated through the Weibull equation, which were associated with their return period (TR). The steady state river water levels were evaluated through HEC-RAS 4.0 model, developed by Hydrologic Engineering Center (HEC) of the United States Army Corps of Engineers Hydrologic Engineering Center (USACE,2006). It is a well-known 1D model that computes water surface elevation (WSE) and velocity at discrete cross-sections by solving continuity, energy and flow resistance (e.g., Manning) equation. Data requirements for HEC-RAS include topographic information in the form of a series of cross-sections, friction parameter in the form of Manning's n values across each cross-section, and flow data including flow rates, flow change locations, and boundary conditions. For a steady state sub-critical simulation, the boundary condition is a known downstream WSE, in this case the elevated water level due to wave setup, wind setup and inverted barometer, while the upstream boundary condition consisted in WSE corresponding to river discharges associated to different return periods. The results of the simulations evidence, for the last 10 kilometers of the river, the burst of critical inundation scenarios even with moderate flow discharge, if associated with concurrent storm surge which increase the water level at the river mouth, obstructing normal flow discharge.

Projections of extreme water level events for atolls in the western Tropical Pacific

NASA Astrophysics Data System (ADS)

Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

2014-12-01

Conditions that lead to extreme water levels and coastal flooding are examined for atolls in the Republic of the Marshall Islands based on a recent field study of wave transformations over fringing reefs, tide gauge observations, and wave model hindcasts. Wave-driven water level extremes pose the largest threat to atoll shorelines, with coastal levels scaling as approximately one-third of the incident breaking wave height. The wave-driven coastal water level is partitioned into a mean setup, low frequency oscillations associated with cross-reef quasi-standing modes, and wind waves that reach the shore after undergoing high dissipation due to breaking and bottom friction. All three components depend on the water level over the reef; however, the sum of the components is independent of water level due to cancelling effects. Wave hindcasts suggest that wave-driven water level extremes capable of coastal flooding are infrequent events that require a peak wave event to coincide with mid- to high-tide conditions. Interannual and decadal variations in sea level do not change the frequency of these events appreciably. Future sea-level rise scenarios significantly increase the flooding threat associated with wave events, with a nearly exponential increase in flooding days per year as sea level exceeds 0.3 to 1.0 m above current levels.

A Plumber's-Eye View of Xylem Water Transport in Woody Plants

ERIC Educational Resources Information Center

Martinez-Vilalta, Jordi; Pinol, Josep

2004-01-01

We present a practical for university-level students aimed at measuring and comparing xylem hydraulic properties of co-existing plant species. After sampling branches of several woody species in the field, their main hydraulic properties were measured using a simple set-up. Hydraulic conductivity ("K[subscript h]") was calculated as the ratio…

Water tunnel flow visualization using a laser

NASA Technical Reports Server (NTRS)

Beckner, C.; Curry, R. E.

1985-01-01

Laser systems for flow visualization in water tunnels (similar to the vapor screen technique used in wind tunnels) can provide two-dimensional cross-sectional views of complex flow fields. This parametric study documents the practical application of the laser-enhanced visualization (LEV) technique to water tunnel testing. Aspects of the study include laser power levels, flow seeding (using flourescent dyes and embedded particulates), model preparation, and photographic techniques. The results of this study are discussed to provide potential users with basic information to aid in the design and setup of an LEV system.

Preliminary Study of Realistic Blast Impact on Cultured Brain Slices

DTIC Science & Technology

2015-04-01

and/or multiple impacts in water. 3. Experimental Setup 3.1 The Aquarium Setup A 30.5-cm by 34.5- × 65-cm water-filled polymethylmethacrylate ...sodium bicarbonate PAGE polyacrylamide gel electrophoresis PMMA polymethylmethacrylate RDECOM U.S. Army Research Development and Engineering Command

A water pumping control system with a programmable logic controller (PLC) and industrial wireless modules for industrial plants--an experimental setup.

PubMed

Bayindir, Ramazan; Cetinceviz, Yucel

2011-04-01

This paper describes a water pumping control system that is designed for production plants and implemented in an experimental setup in a laboratory. These plants contain harsh environments in which chemicals, vibrations or moving parts exist that could potentially damage the cabling or wires that are part of the control system. Furthermore, the data has to be transferred over paths that are accessible to the public. The control systems that it uses are a programmable logic controller (PLC) and industrial wireless local area network (IWLAN) technologies. It is implemented by a PLC, an communication processor (CP), two IWLAN modules, and a distributed input/output (I/O) module, as well as the water pump and sensors. Our system communication is based on an Industrial Ethernet and uses the standard Transport Control Protocol/Internet Protocol for parameterisation, configuration and diagnostics. The main function of the PLC is to send a digital signal to the water pump to turn it on or off, based on the tank level, using a pressure transmitter and inputs from limit switches that indicate the level of the water in the tank. This paper aims to provide a convenient solution in process plants where cabling is not possible. It also has lower installation and maintenance cost, provides reliable operation, and robust and flexible construction, suitable for industrial applications. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

The efficiency of macroporous polystyrene ion-exchange resins in natural organic matter removal from surface water

NASA Astrophysics Data System (ADS)

Urbanowska, Agnieszka; Kabsch-Korbutowicz, Małgorzata

2017-11-01

Natural water sources used for water treatment contains various organic and inorganic compounds. Surface waters are commonly contaminated with natural organic matter (NOM). NOM removal from water is important e.g. due to lowering the risk of disinfection by-product formation during chlorination. Ion exchange with the use of synthetic ion-exchange resins is an alternative process to typical NOM removal approach (e.g. coagulation, adsorption or oxidation) as most NOM compounds have anionic character. Moreover, neutral fraction could be removed from water due to its adsorption on resin surface. In this study, applicability of two macroporous, polystyrene ion exchange resins (BD400FD and A100) in NOM removal from water was assessed including comparison of treatment efficiency in various process set-ups and conditions. Moreover, resin regeneration effectivity was determined. Obtained results shown that examined resins could be applied in NOM removal and it should be noticed that column set-up yielded better results (contrary to batch set-up). Among the examined resins A100 one possessed better properties. It was determined that increase of solution pH resulted in a slight decrease in treatment efficiency while higher temperature improved it. It was also observed that regeneration efficiency was comparable in both tested methods but batch set-up required less reagents.

Forecasting the impact of storm waves and sea-level rise on Midway Atoll and Laysan Island within the Papahānaumokuākea Marine National Monument—a comparison of passive versus dynamic inundation models

USGS Publications Warehouse

Storlazzi, Curt D.; Berkowitz, Paul; Reynolds, Michelle H.; Logan, Joshua B.

2013-01-01

Two inundation events in 2011 underscored the potential for elevated water levels to damage infrastructure and affect terrestrial ecosystems on the low-lying Northwestern Hawaiian Islands in the Papahānaumokuākea Marine National Monument. The goal of this study was to compare passive "bathtub" inundation models based on geographic information systems (GIS) to those that include dynamic water levels caused by wave-induced set-up and run-up for two end-member island morphologies: Midway, a classic atoll with islands on the shallow (2-8 m) atoll rim and a deep, central lagoon; and Laysan, which is characterized by a deep (20-30 m) atoll rim and an island at the center of the atoll. Vulnerability to elevated water levels was assessed using hindcast wind and wave data to drive coupled physics-based numerical wave, current, and water-level models for the atolls. The resulting model data were then used to compute run-up elevations using a parametric run-up equation under both present conditions and future sea-level-rise scenarios. In both geomorphologies, wave heights and wavelengths adjacent to the island shorelines increased more than three times and four times, respectively, with increasing values of sea-level rise, as more deep-water wave energy could propagate over the atoll rim and larger wind-driven waves could develop on the atoll. Although these increases in water depth resulted in decreased set-up along the islands’ shorelines, the larger wave heights and longer wavelengths due to sea-level rise increased the resulting wave-induced run-up. Run-up values were spatially heterogeneous and dependent on the direction of incident wave direction, bathymetry, and island configuration. Island inundation was modeled to increase substantially when wave-driven effects were included, suggesting that inundation and impacts to infrastructure and terrestrial habitats will occur at lower values of predicted sea-level rise, and thus sooner in the 21st century, than suggested by passive GIS-based "bathtub" inundation models. Lastly, observations and the modeling results suggest that classic atolls with islands on a shallow atoll rim are more susceptible to the combined effects of sea-level rise and wave-driven inundation than atolls characterized by a deep atoll rim.

Spatial and temporal controls of atoll island inundation: implications for urbanized atolls in the Marshall Islands.

NASA Astrophysics Data System (ADS)

Ford, M.; Becker, J. M.; Merrifield, M. A.

2012-12-01

Atoll islands are highly vulnerable to a range of inundation hazards. The impacts of such hazards are expected to be magnified as a result of continued sea-level rise. Both recent and historic inundation events provide unique insights into the requisite conditions necessary to initiate island inundation. A number of recent and historic inundation events are presented in order to examine the oceanographic and meteorological conditions driving inundation of a densely populated, urbanized atoll in the central Pacific. Analysis of inundation events suggests that a number of key drivers contribute to the spatial and temporal extent of island inundation, with unique degrees of predictability and resultant impact signatures apparent on island geomorphology and local anthropogenic activities. Results indicate three distinct drivers of inundation hazards exist. Firstly, tropical storms and typhoons elevate sea level through inverse barometric setup, wind setup and a range of wave driven processes and have caused considerable impact on atolls within the Marshall Islands. Secondly, super-elevated sea level conditions resulting from the combination of seasonal high tides and quasi-cyclical La Nina conditions drive inundation of low-lying lagoon facing coastal areas. Thirdly, long period swell conditions, typically generated by distant storms, can elevate reef-flat water levels through wave setup and infragravity wave oscillations. Such wave conditions can over wash the ocean-facing island ridge, often inundating large sections of the island. Reef-flat wave conditions are tidally modulated, with inundation events typically occurring around high tide. However, the two most recent destructive swell-driven inundation events have occurred while tide levels were significantly lower than spring tide levels, suggesting high water levels are not a necessary prerequisite for wave-driven inundation. The different modes of inundation are discussed and grounded within recent and historic inundation events, as well as results of a lengthy reef flat wave observation dataset from Kwajalein and Majuro Atolls in the Republic of the Marshall Islands. Future impacts of continued sea-level rise are considered on each mode of island inundation and the implications for local response discussed within the context of urbanised atoll islands.

Mechanisms of wave‐driven water level variability on reef‐fringed coastlines

USGS Publications Warehouse

Buckley, Mark L.; Lowe, Ryan J.; Hansen, Jeff E; van Dongeren, Ap R.; Storlazzi, Curt

2018-01-01

Wave‐driven water level variability (and runup at the shoreline) is a significant cause of coastal flooding induced by storms. Wave runup is challenging to predict, particularly along tropical coral reef‐fringed coastlines due to the steep bathymetric profiles and large bottom roughness generated by reef organisms, which can violate assumptions in conventional models applied to open sandy coastlines. To investigate the mechanisms of wave‐driven water level variability on a reef‐fringed coastline, we performed a set of laboratory flume experiments on an along‐shore uniform bathymetric profile with and without bottom roughness. Wave setup and waves at frequencies lower than the incident sea‐swell forcing (infragravity waves) were found to be the dominant components of runup. These infragravity waves were positively correlated with offshore wave groups, signifying they were generated in the surf zone by the oscillation of the breakpoint. On the reef flat and at the shoreline, the low‐frequency waves formed a standing wave pattern with energy concentrated at the natural frequencies of the reef flat, indicating resonant amplification. Roughness elements used in the flume to mimic large reef bottom roughness reduced low frequency motions on the reef flat and reduced wave run up by 30% on average, compared to the runs over a smooth bed. These results provide insight into sea‐swell and infragravity wave transformation and wave setup dynamics on steep‐sloped coastlines, and the effect that future losses of reef bottom roughness may have on coastal flooding along reef‐fringed coasts.

Efficacy and workload analysis of a fixed vertical couch position technique and a fixed‐action–level protocol in whole‐breast radiotherapy

PubMed Central

Verhoeven, Karolien; Weltens, Caroline; Van den Heuvel, Frank

2015-01-01

Quantification of the setup errors is vital to define appropriate setup margins preventing geographical misses. The no‐action–level (NAL) correction protocol reduces the systematic setup errors and, hence, the setup margins. The manual entry of the setup corrections in the record‐and‐verify software, however, increases the susceptibility of the NAL protocol to human errors. Moreover, the impact of the skin mobility on the anteroposterior patient setup reproducibility in whole‐breast radiotherapy (WBRT) is unknown. In this study, we therefore investigated the potential of fixed vertical couch position‐based patient setup in WBRT. The possibility to introduce a threshold for correction of the systematic setup errors was also explored. We measured the anteroposterior, mediolateral, and superior–inferior setup errors during fractions 1–12 and weekly thereafter with tangential angled single modality paired imaging. These setup data were used to simulate the residual setup errors of the NAL protocol, the fixed vertical couch position protocol, and the fixed‐action–level protocol with different correction thresholds. Population statistics of the setup errors of 20 breast cancer patients and 20 breast cancer patients with additional regional lymph node (LN) irradiation were calculated to determine the setup margins of each off‐line correction protocol. Our data showed the potential of the fixed vertical couch position protocol to restrict the systematic and random anteroposterior residual setup errors to 1.8 mm and 2.2 mm, respectively. Compared to the NAL protocol, a correction threshold of 2.5 mm reduced the frequency of mediolateral and superior–inferior setup corrections with 40% and 63%, respectively. The implementation of the correction threshold did not deteriorate the accuracy of the off‐line setup correction compared to the NAL protocol. The combination of the fixed vertical couch position protocol, for correction of the anteroposterior setup error, and the fixed‐action–level protocol with 2.5 mm correction threshold, for correction of the mediolateral and the superior–inferior setup errors, was proved to provide adequate and comparable patient setup accuracy in WBRT and WBRT with additional LN irradiation. PACS numbers: 87.53.Kn, 87.57.‐s

Under-estimated wave contribution to coastal sea-level rise

NASA Astrophysics Data System (ADS)

Melet, Angélique; Meyssignac, Benoit; Almar, Rafael; Le Cozannet, Gonéri

2018-03-01

Coastal communities are threatened by sea-level changes operating at various spatial scales; global to regional variations are associated with glacier and ice sheet loss and ocean thermal expansion, while smaller coastal-scale variations are also related to atmospheric surges, tides and waves. Here, using 23 years (1993-2015) of global coastal sea-level observations, we examine the contribution of these latter processes to long-term sea-level rise, which, to date, have been relatively less explored. It is found that wave contributions can strongly dampen or enhance the effects of thermal expansion and land ice loss on coastal water-level changes at interannual-to-multidecadal timescales. Along the US West Coast, for example, negative wave-induced trends dominate, leading to negative net water-level trends. Accurate estimates of past, present and future coastal sea-level rise therefore need to consider low-frequency contributions of wave set-up and swash.

Application of water-assisted ultraviolet light processing on the inactivation of murine norovirus on blueberries.

PubMed

Liu, Chuhan; Li, Xinhui; Chen, Haiqiang

2015-12-02

In this study, a novel set-up using water-assisted UV processing was developed and evaluated for its decontamination efficacy against murine norovirus (MNV-1) inoculated on fresh blueberries for both small and large-scale experimental setups. Blueberries were skin-inoculated with MNV-1 and treated for 1-5 min with UV directly (dry UV) or immersed in agitated water during UV treatment (water-assisted UV). The effect of the presence of 2% (v/v) blueberry juice or 5% crushed blueberries (w/w) in wash water was also evaluated. Results showed that water-assisted UV treatment generally showed higher efficacies than dry UV treatment. With 12,000 J/m(2) UV treatment in small-scale setup, MNV reductions of >4.32- and 2.48-log were achieved by water-assisted UV and dry UV treatments, respectively. Water-assisted UV showed similar inactivating efficacy as 10-ppm chlorine wash. No virus was detected in wash water after UV treatment or chlorine wash. MNV-1 was more easily killed on skin-inoculated blueberries compared with calyx-inoculated berries. When clear water was used as wash water in the large-scale setup, water-assisted UV treatment (UV dose of 12,000 J/m(2)) resulted in >3.20 log and 1.81 log MNV-1 reductions for skin- and calyx-inoculated berries, respectively. The presence of 2% blueberry juice in wash water decreased the decontamination efficacy of water-assisted UV and chlorine washing treatments. To improve the inactivation efficacy, the effect of combining water-assisted UV treatment with chlorine washing was also evaluated. The combined treatment had better or similar inactivation efficacy compared to water-assisted UV treatment and chlorine washing alone. Findings of this study suggest that water-assisted UV treatment could be used as an alternative to chlorine washing for blueberries and potentially for other fresh produce. Copyright © 2015 Elsevier B.V. All rights reserved.

Make Your Own Transpiring Tree

ERIC Educational Resources Information Center

Martinez Vilalta, Jordi; Sauret, Miquel; Duro, Alicia; Pinol, Josep

2003-01-01

In this paper we present a simple set-up that illustrates the mechanism of sap ascent in plants and demonstrates that it can easily draw water up to heights of a few meters. The set-up consists of a tube with the lower end submerged in water and the upper one connected to a filter supported by a standard filter-holder. The evaporation of water…

Operating manual for the R200 downhole recorder with husky hunter retriever

USGS Publications Warehouse

Johnson, Roy A.; Rorabaugh, James I.

1988-01-01

The R200 Downhole Recorder is a battery-powered device that, when placed in a well casing, monitors water levels for a period of up to 1 year. This instrument measures a 1- to 70-foot range of water levels. These water-level data can be retrieved through use of a commercially available portable microcomputer. The R200 Downhole Recorder was developed at the U.S. Geological Survey 's Hydrologic Instrumentation Facility, Stennis Space Center, Mississippi. This operating manual describes the R200 Downhole Recorder, provides initial set-up instructions, and gives directions for on-site operation. Design specifications and routine maintenance steps are included. The R200 data-retriever program is a user-friendly, menu-driven program. The manual guides the user through the procedures required to perform specific operations. Numerous screens are reproduced in the text with a discussion of user input for desired responses. Help is provided for specific problems. (USGS)

Operating manual for the R200 downhole recorder with Tandy 102 retriever

USGS Publications Warehouse

Johnson, Roy A.; Rorabaugh, James I.

1988-01-01

The R200 Downhole Recorder is a battery-powered device that, when placed in a well casing, monitors water levels for a period of up to 1 year. This instrument measures a 1- to 70-ft range of water levels. These water level data can be retrieved through use of a commercially available portable microcomputer. The R200 Downhole Recorder was developed at the U. S. Geological Survey 's Hydrologic Instrumentation Facility, Stennis Space Center, Mississippi. This operating manual describes the R200 Downhole Recorder, provides initial set-up instructions, and gives directions for on-site operation. Design specifications and routine maintenance steps are included. The R200 data-retriever program is a user-friendly, menu-driven program. The manual guides the user through the procedures required to perform specific operations. Numerous screens are reproduced in the text with a discussion of user input for desired responses. Help is provided for specific problems. (USGS)

Experimental Evaluation of a Water Shield for a Surface Power Reactor

NASA Technical Reports Server (NTRS)

Pearson, J. B.; Reid, R.; Sadasivan, P.; Stewart, E.

2007-01-01

A water based shielding system is being investigated for use on initial lunar surface power systems. The use of water may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. A representative lunar surface reactor design is evaluated at various power levels in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The evaluation compares the experimental data from the WST to CFD models. Performance of a water shield on the lunar surface is predicted by CFD models anchored to test data, and by matching relevant dimensionless parameters.

Understanding Variability in Beach Slope to Improve Forecasts of Storm-induced Water Levels

NASA Astrophysics Data System (ADS)

Doran, K. S.; Stockdon, H. F.; Long, J.

2014-12-01

The National Assessment of Hurricane-Induced Coastal Erosion Hazards combines measurements of beach morphology with storm hydrodynamics to produce forecasts of coastal change during storms for the Gulf of Mexico and Atlantic coastlines of the United States. Wave-induced water levels are estimated using modeled offshore wave height and period and measured beach slope (from dune toe to shoreline) through the empirical parameterization of Stockdon et al. (2006). Spatial and temporal variability in beach slope leads to corresponding variability in predicted wave setup and swash. Seasonal and storm-induced changes in beach slope can lead to differences on the order of a meter in wave runup elevation, making accurate specification of this parameter essential to skillful forecasts of coastal change. Spatial variation in beach slope is accounted for through alongshore averaging, but temporal variability in beach slope is not included in the final computation of the likelihood of coastal change. Additionally, input morphology may be years old and potentially very different than the conditions present during forecast storm. In order to improve our forecasts of hurricane-induced coastal erosion hazards, the temporal variability of beach slope must be included in the final uncertainty of modeled wave-induced water levels. Frequently collected field measurements of lidar-based beach morphology are examined for study sites in Duck, North Carolina, Treasure Island, Florida, Assateague Island, Virginia, and Dauphin Island, Alabama, with some records extending over a period of 15 years. Understanding the variability of slopes at these sites will help provide estimates of associated water level uncertainty which can then be applied to other areas where lidar observations are infrequent, and improve the overall skill of future forecasts of storm-induced coastal change. Stockdon, H. F., Holman, R. A., Howd, P. A., and Sallenger Jr, A. H. (2006). Empirical parameterization of setup,swash, and runup. Coastal engineering, 53(7), 573-588.

[Testing the efficacy of disinfectants during drinking water treatment. A new experimental set-up at the German EPA (Umweltbundesamt - UBA)].

PubMed

Grützmacher, G; Bartel, H; Althoff, H W; Clemen, S

2007-03-01

A set-up for experiments in the flow-through mode was constructed in order to test the efficacy of substances used for disinfecting water during drinking water treatment. A flow-through mode - in contrast to experiments under stationary conditions (so-called batch experiments) - was chosen, because this experimental design allows experiments to be carried out under constant conditions for an extended time (up to one week) and because efficacy testing is possible repeatedly, simultaneously and under exactly the same conditions for short (about 0.5 min) and also longer (about 47 min) contact times. With this experimental design the effect of biofilms along the inner pipe surfaces can be included in the observations. The construction of the experimental set-up is based on experience with laboratory flow-through systems that were installed by the UBA's drinking water department (formerly Institute for Water-, Soil- and Air Hygiene (WaBoLu) Institute) for testing disinfection with chlorine. In the first step, a test pipe for the simulation of a water works situation was installed. Water of different qualities can be mixed in large volumes beforehand so that the experimental procedure can be run with constant water quality for a minimum of one week. The kinetics of the disinfection reaction can be observed by extracting samples from eight sampling ports situated along the test pipe. In order to assign exact residence times to each of the sampling ports, tracer experiments were performed prior to testing disinfectant efficacy. This paper gives the technical details of the experimental set-up and presents the results of the tracer experiments to provide an introduction with respect to its potential.

Seasonal forecasts of groundwater levels in Lanyang Plain in Taiwan

NASA Astrophysics Data System (ADS)

Chang, Ya-Chi; Lin, Yi-Chiu

2017-04-01

Groundwater plays a critical and important role in world's freshwater resources and it is also an important part of Taiwan's water supply for domestic, agricultural and industrial use. Prolonged dry climatic conditions can induce groundwater drought and may have huge impact on water resources. Therefore, this study utilizes seasonal rainfall forecasts from the Model for Prediction Across Scales (MPAS) to simulate groundwater levels in Lanyang Plain in Taiwan up to three months into future. The MPAS is setup with 120 km uniform grid and the physics schemes including WSM6 micorphysics scheme, Kain-Fritsch cumulus scheme, RRTMG radiation scheme, and YSU planetary boundary layer scheme are used to provide the rainfall forecasts. Results of this study can provide a reference for water resources management to ensure the sustainability of groundwater resources in Lanyang Plain.

Advancing Best Practices for the Formulation of Localized Sea Level Rise/Coastal Inundation Extremes Scenarios for Military Installations in the Pacific Islands

DTIC Science & Technology

2015-07-14

Development Program SLP - Sea Level Pressure SOI - Southern Oscillation Index SON - Statement of Need SST - Sea Surface Temperature iv SWL - Still Water...Level Pressure ( SLP ) from NCEP/NCAR reanalysis). Midway has known wave setup (Aucan et al., 2012) so we explored to what extent we could find an 12...Guam ONI 0.9 Kwajalein ONI 1.1 Pago Pago ONI 1.0 Honolulu SLP 1.3 Nawiliwili SLP 1.4 Kahului SLP 1.2 Hilo SLP 1.3 Mokuoloe SLP 1.2 Naha PDO 1.0 Kawaihae

Direct Coexistence Methods to Determine the Solubility of Salts in Water from Numerical Simulations. Test Case NaCl.

PubMed

Manzanilla-Granados, Héctor M; Saint-Martín, Humberto; Fuentes-Azcatl, Raúl; Alejandre, José

2015-07-02

The solubility of NaCl, an equilibrium between a saturated solution of ions and a solid with a crystalline structure, was obtained from molecular dynamics simulations using the SPC/E and TIP4P-Ew water models. Four initial setups on supersaturated systems were tested on sodium chloride (NaCl) solutions to determine the equilibrium conditions and computational performance: (1) an ionic solution confined between two crystal plates of periodic NaCl, (2) a solution with all the ions initially distributed randomly, (3) a nanocrystal immersed in pure water, and (4) a nanocrystal immersed in an ionic solution. In some cases, the equilibration of the system can take several microseconds. The results from this work showed that the solubility of NaCl was the same, within simulation error, for the four setups, and in agreement with previously reported values from simulations with the setup (1). The system of a nanocrystal immersed in supersaturated solution was found to equilibrate faster than others. In agreement with laser-Doppler droplet measurements, at equilibrium with the solution the crystals in all the setups had a slight positive charge.

Thermal diffusion forced Rayleigh scattering setup optimized for aqueous mixtures.

PubMed

Wiegand, Simone; Ning, Hui; Kriegs, Hartmut

2007-12-27

We developed a thermal diffusion forced Rayleigh scattering (TDFRS) setup operating at a writing wavelength of 980 nm, which corresponds to an absorption band of water with an absorption coefficient of approximately 0.5 cm(-1). Therefore, aqueous mixtures require no dye to convert the light into heat energy. Especially for aqueous system with a complex phase behavior such as surfactant systems, the addition of a water soluble dye can cause artifacts. The infrared-TDFRS (IR-TDFRS) setup has been validated for water/ethanol mixtures with water weight fractions c = 0.5-0.95 and in a temperature range between T = 15 degrees C to T = 35 degrees C. Comparison with literature data shows an excellent agreement. The addition of a small amount (c(dye) approximately 10(-6) wt) of adsorbing dye at the writing wavelength allows also the investigation of organic mixtures. We investigated the three binary mixtures of dodecane, isobutylbenzene, and 1,2,3,4-tetrahydronaphthalene at a weight fraction of c = 0.5 at a temperature of 25 degrees C and found good agreement with the Soret coefficients, which had been obtained in a benchmark test under the same conditions. Therefore, the presented setup is suitable for the investigation of the thermal diffusion behavior in aqueous and organic mixtures, and in the case of aqueous systems, the addition of a dye can be avoided.

Making optics appealing in Colombia through low-cost experiments with lasers

NASA Astrophysics Data System (ADS)

Álvarez, Juan R.; Barbosa, Nicolás.; Cotrino, Sergio; Guzmán, David A.; Mahecha, Víctor; Medina, Cristian; Navarrete, M. Cristina; Uribe, Leonardo; Valencia, Alejandra

2015-10-01

With the aim of making optics reachable to all audiences, regardless of their age or area of study, we have decided to select, build and test a set of four experiments based on optical phenomena. An important factor in our approach is that the experiments should be used by any non-experienced exhibitor to amaze the audience and to arise in them interest in optics. Ease of setup is therefore desired. Requirements such as durability, repeatability and reduced cost are welcome as well. Taking advantage of the low prices of laser pointers, we focused on experiments which use this nowadays accessible element. The experiments that integrate our selection, costing less than USD75, are: a water stream optical fiber, curved light beams on a honey-water mixture, an optical music transmitter-receiver, and holographic film projections. Among the covered concepts are reflection and refraction of light, color, optical communications, optical interference and modern everyday life's applications. We have presented these setups in activities at our university to a wide range of educational levels, from 12-year old students, passing by last year high school students on a career day event, not leaving behind undergraduate students of any discipline. Moved by the positive response of the audience, we plan to expand its application to continuing education courses and kids' science fairs. We proved that having low-cost setups, useful when teaching science in developing countries, can help to broaden the target audience.

Controls on Water Storage, Mixing and Release in a Nested Catchment Set-up with Clean and Mixed Physiographic Characteristics

NASA Astrophysics Data System (ADS)

Pfister, L.; McDonnell, J.; Hissler, C.; Martínez-Carreras, N.; Klaus, J.

2015-12-01

With catchment water storage being only rarely determined, storage dynamics remain largely unknown to date. However, storage bears considerable potential for catchment inter-comparison exercises, as well as it is likely to have an important role in regulating catchment functions. Catchment comparisons across a wide range of environments and scales will help to increase our understanding of relationships between storage dynamics and catchment processes. With respect to the potential of catchment storage for bringing new momentum to catchment classification and catchment processes understanding we currently investigate spatial and temporal variability of dynamic storage in a nested catchment set-up (16 catchments) of the Alzette River basin (Luxembourg, Europe), covering a wide range of geological settings, catchment areas, contrasted landuse, and hydro-meteorological and tracer series. We define catchment storage as the total amount of water stored in a control volume, delimited by the catchment's topographical boundaries and depth of saturated and unsaturated zones. Complementary storage assessments (via input-output dynamics of natural tracers, geographical sounding, groundwater level measurements, soil moisture measurements, hydrometry) are carried out for comparison purposes. In our nested catchment set-up we have (1) assessed dependencies between geology, catchment permeability and winter runoff coefficients, (2) calculated water balance derived catchment storage and mixing potential and quantified how dynamic storage differs between catchments and scales, and (3) examined how stream baseflow dD (as a proxy for baseflow transit time) and integrated flow measures (like the flow duration curve) relate to bedrock geology. Catchments with higher bedrock permeability exhibited larger storage capacities and eventually lower average winter runoff coefficients. Over a time-span of 11 years, all catchments re-produced the same winter runoff coefficients year after year, regardless of their bedrock geology, permeability and winter season storage filling ratios. Ultimately, catchment organisation in our area of interest (i.e. geology, permeability, flowpath length) appeared to have a strong control on winter runoff coefficients, catchment storage and subsequently baseflow dD.

Terahertz Measurement of the Water Content Distribution in Wood Materials

NASA Astrophysics Data System (ADS)

Bensalem, M.; Sommier, A.; Mindeguia, J. C.; Batsale, J. C.; Pradere, C.

2018-02-01

Recently, THz waves have been shown to be an effective technique for investigating the water diffusion within porous media, such as biomaterial or insulation materials. This applicability is due to the sufficient resolution for such applications and the safe levels of radiation. This study aims to achieve contactless absolute water content measurements at a steady state case in semi-transparent solids (wood) using a transmittance THz wave range setup. First, a calibration method is developed to validate an analytical model based on the Beer-Lambert law, linking the absorption coefficient, the density of the solid, and its water content. Then, an estimation of the water content on a local scale in a transient-state case (drying) is performed. This study shows that THz waves are an effective contactless, safe, and low-cost technique for the measurement of water content in a porous medium, such as wood.

Temporal Dynamics and Persistence of Spatial Patterns: from Groundwater to Soil Moisture to Transpiration

NASA Astrophysics Data System (ADS)

Blume, T.; Hassler, S. K.; Weiler, M.

2017-12-01

Hydrological science still struggles with the fact that while we wish for spatially continuous images or movies of state variables and fluxes at the landscape scale, most of our direct measurements are point measurements. To date regional measurements resolving landscape scale patterns can only be obtained by remote sensing methods, with the common drawback that they remain near the earth surface and that temporal resolution is generally low. However, distributed monitoring networks at the landscape scale provide the opportunity for detailed and time-continuous pattern exploration. Even though measurements are spatially discontinuous, the large number of sampling points and experimental setups specifically designed for the purpose of landscape pattern investigation open up new avenues of regional hydrological analyses. The CAOS hydrological observatory in Luxembourg offers a unique setup to investigate questions of temporal stability, pattern evolution and persistence of certain states. The experimental setup consists of 45 sensor clusters. These sensor clusters cover three different geologies, two land use classes, five different landscape positions, and contrasting aspects. At each of these sensor clusters three soil moisture/soil temperature profiles, basic climate variables, sapflow, shallow groundwater, and stream water levels were measured continuously for the past 4 years. We will focus on characteristic landscape patterns of various hydrological state variables and fluxes, studying their temporal stability on the one hand and the dependence of patterns on hydrological states on the other hand (e.g. wet vs dry). This is extended to time-continuous pattern analysis based on time series of spatial rank correlation coefficients. Analyses focus on the absolute values of soil moisture, soil temperature, groundwater levels and sapflow, but also investigate the spatial pattern of the daily changes of these variables. The analysis aims at identifying hydrologic signatures of the processes or landscape characteristics acting as major controls. While groundwater, soil water and transpiration are closely linked by the water cycle, they are controlled by different processes and we expect this to be reflected in interlinked but not necessarily congruent patterns and responses.

The 2004 Indian Ocean Tsunami in Maldives: waves and disaster affected by shape of coral reefs and islands

NASA Astrophysics Data System (ADS)

Kan, H.; Ali, M.; Riyaz, M.

2005-12-01

In Maldives, 39 islands are significantly damaged among 200 inhabited islands and nearly a third of the Maldivian people are severely affected by the Indian Ocean Tsunami in 26 December 2004. We surveyed tsunami impact in 43 islands by measuring island topography and run-up height, interview to local people and mapping of the flooded and destructed areas. The differences in tsunami height and disaster corresponding to the atoll shape and island topography are observed. In the northern atolls, atoll rims consist of many ring-shaped reefs, i.e. miniature atolls called `faro', and interrupted many channels between them. The interrupted atoll rim may play an important role to reducing tsunami run-up height. Severe damage was not observed in the eastern coast of the islands. Beach ridge also contribute to the protection against tsunami. However, in some islands, houses beside the lagoon are damaged by backwashing floodwater from the lagoon. Water marks show the run-up height of -1.8m above MSL. The lagoon water-level seems to set-up by tsunami which permeates into the lagoon through the interrupted atoll rim. The disaster was severe at the southern atolls of Meemu, Thaa and Laamu. The higher run-up heights of up to 3.2m above MSL and enormous building damages were observed at the islands on the eastern atoll rims. The continuous atoll rim of these atolls may reinforce tsunami impact at the eastern islands. In addition, tsunami surge washed the islands totally because of low island topography without beach ridge. Significant floodwater from lagoon was not observed in these atolls. It seems the lagoon water-level was not set-up largely. The continuous atoll rim reduces the tsunami influence to the lagoon and the western side of the atolls. The continuity of atoll rim is probably the major factor to cause the difference in water movement, i.e. tsunami run-up and lagoon set-up, which affects the disaster in the islands. Beach ridge contribute to reduce the tsunami impact to the settlement and agricultural land. Our results may elucidate secure atoll and island type to mitigate the risk of future tsunamis on atoll nations/districts in the Pacific and the Indian Ocean.

Laser-induced fluorescence spectrometer based on tunable color center laser for low-impurity-solution diagnostic and analysis

NASA Astrophysics Data System (ADS)

Basiev, Tasoltan T.; Fedorov, Vladimir V.; Karasik, Alexander Y.; Lin'kov, S. I.; Orlovskii, Yurii V.; Osiko, Vyacheslav V.; Panov, Vitaly A.; Prokhorov, Alexander M.; Vorob'ev, Ivan N.; Zverev, Peter G.

1996-11-01

Solid state (SS) tunable LiF:F2 color center laser with second and fourth harmonic generation for visible and ultra violet spectral ranges was developed for the laser induced fluorescence spectroscopy (LIFS). The construction and properties of excitation, registration and flame atomization systems for water solution diagnostic are discussed. The testing experiment with low iron concentrated water sample exhibits ultrahigh sensitivity which was estimated to be 0.05 ppb in our set-up. The SS LIFS spectrometer developed is usable to measure more than 42 metal elements in solution on the ppm, ppb level for various medical and biological applications.

SI-traceable and dynamic reference gas mixtures for water vapour at polar and high troposphere atmospheric levels

NASA Astrophysics Data System (ADS)

Guillevic, Myriam; Pascale, Céline; Mutter, Daniel; Wettstein, Sascha; Niederhauser, Bernhard

2017-04-01

In the framework of METAS' AtmoChem-ECV project, new facilities are currently being developed to generate reference gas mixtures for water vapour at concentrations measured in the high troposphere and polar regions, in the range 1-20 µmol/mol (ppm). The generation method is dynamic (the mixture is produced continuously over time) and SI-traceable (i.e. the amount of substance fraction in mole per mole is traceable to the definition of SI-units). The generation process is composed of three successive steps. The first step is to purify the matrix gas, nitrogen or synthetic air. Second, this matrix gas is spiked with the pure substance using a permeation technique: a permeation device contains a few grams of pure water in liquid form and loses it linearly over time by permeation through a membrane. In a third step, to reach the desired concentration, the first, high concentration mixture exiting the permeation chamber is then diluted with a chosen flow of matrix gas with one or two subsequent dilution steps. All flows are piloted by mass flow controllers. All parts in contact with the gas mixture are passivated using coated surfaces, to reduce adsorption/desorption processes as much as possible. The mixture can eventually be directly used to calibrate an analyser. The standard mixture produced by METAS' dynamic setup was injected into a chilled mirror from MBW Calibration AG, the designated institute for absolute humidity calibration in Switzerland. The used chilled mirror, model 373LX, is able to measure frost point and sample pressure and therefore calculate the water vapour concentration. This intercomparison of the two systems was performed in the range 4-18 ppm water vapour in synthetic air, at two different pressure levels, 1013.25 hPa and 2000 hPa. We present here METAS' dynamic setup, its uncertainty budget and the first results of the intercomparison with MBW's chilled mirror.

Adaptive resolution simulation of oligonucleotides

NASA Astrophysics Data System (ADS)

Netz, Paulo A.; Potestio, Raffaello; Kremer, Kurt

2016-12-01

Nucleic acids are characterized by a complex hierarchical structure and a variety of interaction mechanisms with other molecules. These features suggest the need of multiscale simulation methods in order to grasp the relevant physical properties of deoxyribonucleic acid (DNA) and RNA using in silico experiments. Here we report an implementation of a dual-resolution modeling of a DNA oligonucleotide in physiological conditions; in the presented setup only the nucleotide molecule and the solvent and ions in its proximity are described at the atomistic level; in contrast, the water molecules and ions far from the DNA are represented as computationally less expensive coarse-grained particles. Through the analysis of several structural and dynamical parameters, we show that this setup reliably reproduces the physical properties of the DNA molecule as observed in reference atomistic simulations. These results represent a first step towards a realistic multiscale modeling of nucleic acids and provide a quantitatively solid ground for their simulation using dual-resolution methods.

An Environmental Friendly Procedure for Photometric Determination of Hypochlorite in Tap Water Employing a Miniaturized Multicommuted Flow Analysis Setup

PubMed Central

Borges, Sivanildo S.; Reis, Boaventura F.

2011-01-01

A photometric procedure for the determination of ClO− in tap water employing a miniaturized multicommuted flow analysis setup and an LED-based photometer is described. The analytical procedure was implemented using leucocrystal violet (LCV; 4,4′,4′′-methylidynetris (N,N-dimethylaniline), C25H31N3) as a chromogenic reagent. Solenoid micropumps employed for solutions propelling were assembled together with the photometer in order to compose a compact unit of small dimensions. After control variables optimization, the system was applied for the determination of ClO− in samples of tap water, and aiming accuracy assessment samples were also analyzed using an independent method. Applying the paired t-test between results obtained using both methods, no significant difference at the 95% confidence level was observed. Other useful features include low reagent consumption, 2.4 μg of LCV per determination, a linear response ranging from 0.02 up to 2.0 mg L−1  ClO−, a relative standard deviation of 1.0% (n = 11) for samples containing 0.2 mg L−1  ClO−, a detection limit of 6.0 μg L−1  ClO−, a sampling throughput of 84 determinations per hour, and a waste generation of 432 μL per determination. PMID:21747732

Absolute, pressure-dependent validation of a calibration-free, airborne laser hygrometer transfer standard (SEALDH-II) from 5 to 1200 ppmv using a metrological humidity generator

NASA Astrophysics Data System (ADS)

Buchholz, Bernhard; Ebert, Volker

2018-01-01

Highly accurate water vapor measurements are indispensable for understanding a variety of scientific questions as well as industrial processes. While in metrology water vapor concentrations can be defined, generated, and measured with relative uncertainties in the single percentage range, field-deployable airborne instruments deviate even under quasistatic laboratory conditions up to 10-20 %. The novel SEALDH-II hygrometer, a calibration-free, tuneable diode laser spectrometer, bridges this gap by implementing a new holistic concept to achieve higher accuracy levels in the field. We present in this paper the absolute validation of SEALDH-II at a traceable humidity generator during 23 days of permanent operation at 15 different H2O mole fraction levels between 5 and 1200 ppmv. At each mole fraction level, we studied the pressure dependence at six different gas pressures between 65 and 950 hPa. Further, we describe the setup for this metrological validation, the challenges to overcome when assessing water vapor measurements on a high accuracy level, and the comparison results. With this validation, SEALDH-II is the first airborne, metrologically validated humidity transfer standard which links several scientific airborne and laboratory measurement campaigns to the international metrological water vapor scale.

Water Quality Assessment of Ayeyarwady River in Myanmar

NASA Astrophysics Data System (ADS)

Thatoe Nwe Win, Thanda; Bogaard, Thom; van de Giesen, Nick

2015-04-01

Myanmar's socio-economic activities, urbanisation, industrial operations and agricultural production have increased rapidly in recent years. With the increase of socio-economic development and climate change impacts, there is an increasing threat on quantity and quality of water resources. In Myanmar, some of the drinking water coverage still comes from unimproved sources including rivers. The Ayeyarwady River is the main river in Myanmar draining most of the country's area. The use of chemical fertilizer in the agriculture, the mining activities in the catchment area, wastewater effluents from the industries and communities and other development activities generate pollutants of different nature. Therefore water quality monitoring is of utmost importance. In Myanmar, there are many government organizations linked to water quality management. Each water organization monitors water quality for their own purposes. The monitoring is haphazard, short term and based on individual interest and the available equipment. The monitoring is not properly coordinated and a quality assurance programme is not incorporated in most of the work. As a result, comprehensive data on the water quality of rivers in Myanmar is not available. To provide basic information, action is needed at all management levels. The need for comprehensive and accurate assessments of trends in water quality has been recognized. For such an assessment, reliable monitoring data are essential. The objective of our work is to set-up a multi-objective surface water quality monitoring programme. The need for a scientifically designed network to monitor the Ayeyarwady river water quality is obvious as only limited and scattered data on water quality is available. However, the set-up should also take into account the current socio-economic situation and should be flexible to adjust after first years of monitoring. Additionally, a state-of-the-art baseline river water quality sampling program is required which will take place during the low water season of March, 2015. The water quality information available for the Ayeyarwady as well as the baseline sampling of March 2015 will be presented. Furthermore, the specific scientific ideas but also organisational challenges for the future surface water quality monitoring network of the Ayeyarwady will be discussed.

Laboratory tests on heat treatment of ballast water using engine waste heat.

PubMed

Balaji, Rajoo; Lee Siang, Hing; Yaakob, Omar; Koh, Kho King; Adnan, Faizul Amri Bin; Ismail, Nasrudin Bin; Ahmad, Badruzzaman Bin; Ismail, Mohd Arif Bin; Wan Nik, W B

2018-05-01

Waste heat recovery from shipboard machineries could be a potential source for heat treatment of ballast water. Similar to a shipboard schematic arrangement, a laboratory-scale engine-heat exchanger set-up harvesting waste heat from jacket water and exhaust gases was erected to test the level of species' mortalities. Mortalities were also assessed under experimental conditions for cultured and natural plankton communities at laboratory level. Effect of pump impellers on species' mortalities were also tested. Exposures between 60°C and 70°C for 60 sec resulted in 80-100% mortalities. Mortalities due to pump impeller effects were observed in the range of 70-100% for zooplankton. On the laboratory-scale arrangement, >95% mortalities of phytoplankton, zooplankton and bacteria were recorded. It was demonstrated that the temperature of tropical sea waters used as secondary coolant can be raised to cause species' mortalities, employing engine exhaust gases. The results also indicated that pump impeller effects will enhance species' mortalities. The limitations of the shipboard application of this method would be the large ballast volumes, flow rates and time for treatment.

Heavy duty precision leveling jacks expedite setup time on horizontal boring mill

NASA Technical Reports Server (NTRS)

Dellenbaugh, W.; Jones, C.

1966-01-01

Leveling jack is a precise alignment tool which expedites the setup of components or assemblies up to 2500 pounds on horizontal boring mills. This tool eliminates the necessity of wedges and blocks to shim the components to proper position.

SU-E-J-39: Dosimetric Benefit of Implanted Marker-Based CBCT Setup for Definitive Prostatic Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhen, H; Wu, Z; Bluemenfeld, P

Purpose Daily setup for definitive prostatic radiotherapy is challenged by suboptimal visibility of the prostate boundary and daily variation of rectum shape and position. For patients with improved bowel preparation, we conducted a dosimetric comparison between prostate implanted marker (IM)-based daily setup and anterior rectal wall (ARW)-based setup, with the hypothesis that the former leads to adequate target coverage with better rectal sparing. Methods Five IMRT/VMAT prostate cases with implanted markers were selected for analysis. Daily CBCT showed improvement of the rectal volume compared to planning CT. For each patient, the prostate and rectum were contoured on three CBCT imagesmore » (fraction 5/15/25) with subsequent physician review. The CBCTs were then registered to a planning CT using IM-based registration. The deviation of ARW positions from planning CT to CBCT were analyzed at various sup-inf levels (−1.8 cm to 1.8 cm from level of prostate center). To estimate the potential dosimetric impact from ARW-based setup, the treatment plans were recalculated using A-P shifts ranging from −1mm to +6mm. Clinically important rectum DVH values including Dmax, D3cc and Dmean were computed. Results For the studied patients, we observed on average 32% rectum volume reduction from planning CT to CBCT. As a Results, the ARW on average shifts posteriorly by −1mm to +5mm, depending on the sup-inf level of observation, with larger shifts observed at more superior levels. Recalculation shows that when ARW shifts 1mm posteriorly, ARW-based CBCT setup leads to a 1.0%, 4.2%, and 3.2% increase in rectum Dmax, D3cc, and Dmean, respectively, compared to IM-based setup. The dosimetric deviations increase to 4.7%, 25.8% and 24.7% when ARW shifts 6mm posteriorly. No significant prostate-only dose difference was observed. Conclusion For patients with improved bowel preparation, IM-based CBCT setup leads to accurate prostate coverage along with significantly lower rectal dose, compared to ARW-based setup.« less

Optical sensor nanoparticles in artificial sediments--a new tool to visualize O2 dynamics around the rhizome and roots of seagrasses.

PubMed

Koren, Klaus; Brodersen, Kasper E; Jakobsen, Sofie L; Kühl, Michael

2015-02-17

Seagrass communities provide important ecosystems services in coastal environments but are threatened by anthropogenic impacts. Especially the ability of seagrasses to aerate their below-ground tissue and immediate rhizosphere to prevent sulfide intrusion from the surrounding sediment is critical for their resilience to environmental disturbance. There is a need for chemical techniques that can map the O2 distribution and dynamics in the seagrass rhizosphere upon environmental changes and thereby identify critical stress thresholds of e.g. water flow, turbidity, and O2 conditions in the water phase. In a novel experimental approach, we incorporated optical O2 sensor nanoparticles into a transparent artificial sediment matrix consisting of pH-buffered deoxygenated sulfidic agar. Seagrass growth and photosynthesis was not inhibited in the experimental setup when the below-ground biomass was immobilized in the artificial sulfidic sediment with nanoparticles and showed root growth rates (∼ 5 mm day(-1)) and photosynthetic quantum yields (∼ 0.7) comparable to healthy seagrasses in their natural habitat. We mapped the real-time below ground O2 distribution and dynamics in the whole seagrass rhizosphere during experimental manipulation of light exposure and O2 content in the overlaying water. Those manipulations showed that oxygen release from the belowground tissue is much higher in light as compared to darkness and that water column hypoxia leads to diminished oxygen levels around the rhizome/roots. Oxygen release was visualized and analyzed on a whole rhizosphere level, which is a substantial improvement to existing methods relying on point measurements with O2 microsensors or partial mapping of the rhizosphere in close contact with a planar O2 optode. The combined use of optical nanoparticle-based sensors with artificial sediments enables imaging of chemical microenvironments in the rhizosphere of aquatic plants at high spatiotemporal resolution with a relatively simple experimental setup and thus represents a significant methodological advancement for studies of environmental impacts on aquatic plant ecophysiology.

Combustion of Coal/Oil/Water Slurries

NASA Technical Reports Server (NTRS)

Kushida, R. O.

1982-01-01

Proposed test setup would measure combustion performance of new fuels by rapidly heating a droplet of coal/oil/water mixture and recording resulting explosion. Such mixtures are being considered as petroleum substitutes in oil-fired furnaces.

Modelled interglacial carbon cycle dynamics during the Holocene, the Eemian and Marine Isotope Stage (MIS) 11

NASA Astrophysics Data System (ADS)

Kleinen, Thomas; Brovkin, Victor; Munhoven, Guy

2016-11-01

Trends in the atmospheric concentration of CO2 during three recent interglacials - the Holocene, the Eemian and Marine Isotope Stage (MIS) 11 - are investigated using an earth system model of intermediate complexity, which we extended with process-based modules to consider two slow carbon cycle processes - peat accumulation and shallow-water CaCO3 sedimentation (coral reef formation). For all three interglacials, model simulations considering peat accumulation and shallow-water CaCO3 sedimentation substantially improve the agreement between model results and ice core CO2 reconstructions in comparison to a carbon cycle set-up neglecting these processes. This enables us to model the trends in atmospheric CO2, with modelled trends similar to the ice core data, forcing the model only with orbital and sea level changes. During the Holocene, anthropogenic CO2 emissions are required to match the observed rise in atmospheric CO2 after 3 ka BP but are not relevant before this time. Our model experiments show a considerable improvement in the modelled CO2 trends by the inclusion of the slow carbon cycle processes, allowing us to explain the CO2 evolution during the Holocene and two recent interglacials consistently using an identical model set-up.

Uncertainty Evaluation of the New Setup for Measurement of Water-Vapor Permeation Rate by a Dew-Point Sensor

NASA Astrophysics Data System (ADS)

Hudoklin, D.; Šetina, J.; Drnovšek, J.

2012-09-01

The measurement of the water-vapor permeation rate (WVPR) through materials is very important in many industrial applications such as the development of new fabrics and construction materials, in the semiconductor industry, packaging, vacuum techniques, etc. The demand for this kind of measurement grows considerably and thus many different methods for measuring the WVPR are developed and standardized within numerous national and international standards. However, comparison of existing methods shows a low level of mutual agreement. The objective of this paper is to demonstrate the necessary uncertainty evaluation for WVPR measurements, so as to provide a basis for development of a corresponding reference measurement standard. This paper presents a specially developed measurement setup, which employs a precision dew-point sensor for WVPR measurements on specimens of different shapes. The paper also presents a physical model, which tries to account for both dynamic and quasi-static methods, the common types of WVPR measurements referred to in standards and scientific publications. An uncertainty evaluation carried out according to the ISO/IEC guide to the expression of uncertainty in measurement (GUM) shows the relative expanded ( k = 2) uncertainty to be 3.0 % for WVPR of 6.71 mg . h-1 (corresponding to permeance of 30.4 mg . m-2. day-1 . hPa-1).

Wave setup over a Pacific Island fringing reef

NASA Astrophysics Data System (ADS)

Vetter, O.; Becker, J. M.; Merrifield, M. A.; Pequignet, A.-C.; Aucan, J.; Boc, S. J.; Pollock, C. E.

2010-12-01

Measurements obtained across a shore-attached, fringing reef on the southeast coast of the island of Guam are examined to determine the relationship between incident waves and wave-driven setup during storm and nonstorm conditions. Wave setup on the reef flat correlates well (r > 0.95) and scales near the shore as approximately 35% of the incident root mean square wave height in 8 m water depth. Waves generated by tropical storm Man-Yi result in a 1.3 m setup during the peak of the storm. Predictions based on traditional setup theory (steady state, inviscid cross-shore momentum and depth-limited wave breaking) and an idealized model of localized wave breaking at the fore reef are in agreement with the observations. The reef flat setup is used to estimate a similarity parameter at breaking that is in agreement with observations from a steeply sloping sandy beach. A weak (˜10%) increase in setup is observed across the reef flat during wave events. The inclusion of bottom stress in the cross-shore momentum balance may account for a portion of this signal, but this assessment is inconclusive as the reef flat currents in some cases are in the wrong direction to account for the increase. An independent check of fringing reef setup dynamics is carried out for measurements at the neighboring island of Saipan with good agreement.

Visible optical radiation generates bactericidal effect applicable for inactivation of health care associated germs demonstrated by inactivation of E. coli and B. subtilis using 405-nm and 460-nm light emitting diodes

NASA Astrophysics Data System (ADS)

Hönes, Katharina; Stangl, Felix; Sift, Michael; Hessling, Martin

2015-07-01

The Ulm University of Applied Sciences is investigating a technique using visible optical radiation (405 nm and 460 nm) to inactivate health-hazardous bacteria in water. A conceivable application could be point-of-use disinfection implementations in developing countries for safe drinking water supply. Another possible application field could be to provide sterile water in medical institutions like hospitals or dental surgeries where contaminated pipework or long-term disuse often results in higher germ concentrations. Optical radiation for disinfection is presently mostly used in UV wavelength ranges but the possibility of bacterial inactivation with visible light was so far generally disregarded. One of the advantages of visible light is, that instead of mercury arc lamps, light emitting diodes could be used, which are commercially available and therefore cost-efficient concerning the visible light spectrum. Furthermore they inherit a considerable longer life span than UV-C LEDs and are non-hazardous in contrast to mercury arc lamps. Above all there are specific germs, like Bacillus subtilis, which show an inactivation resistance to UV-C wavelengths. Due to the totally different deactivation mechanism even higher disinfection rates are reached, compared to Escherichia coli as a standard laboratory germ. By 460 nm a reduction of three log-levels appeared with Bacillus subtilis and a half log-level with Escherichia coli both at a dose of about 300 J/cm². By the more efficient wavelength of 405 nm four and a half log-levels are reached with Bacillus subtilis and one and a half log-level with Escherichia coli also both at a dose of about 300 J/cm². In addition the employed optical setup, which delivered a homogeneous illumination and skirts the need of a stirring technique to compensate irregularities, was an important improvement compared to previous published setups. Evaluated by optical simulation in ZEMAX® the designed optical element provided proven homogeneity distributions with maximum variation of ± 10 %.

An experimental investigation of convective heat transfer at evaporation of kerosene and water in the closed volume

NASA Astrophysics Data System (ADS)

Trushlyakov, V. I.; Lesnyak, I. Y.; Galfetti, L.

2017-09-01

An evaporation of kerosene and water was investigated based on convective heat transfer in the experimental setup simulating a typical volume of the fuel tank of the launch vehicle. Basic criteria of similarity used in choosing the design parameters of the setup, parameters of the coolant and model liquids, were numbers of Reynolds, Prandtl, Biot, and Nusselt. The used coolants were gases, including air and nitrogen; in addition, at the stage of preliminary experiments, products of combustion of hydroxyl-terminated polybutadiene (HTPB) were considered. Boundary conditions were taken for the liquid located on the plate in the form of "drop" and at its uniform film spread in the experimental model setup. On the basis of experimental investigations, the temperature values were obtained for the system "gas-liquid-wall", and areas of mass transfer surface and heat transfer coefficients of "gas-liquid" and "gas-plate" were determined for coolants (air and nitrogen) and for liquids (water and kerosene). The comparative analysis of the obtained results and the known data was carried out. Proposals for experiments using coolants based on HTPB combustion products have been formulated.

Vadose Zone Monitoring as a Key to Groundwater Protection from Pollution Hazard

NASA Astrophysics Data System (ADS)

Dahan, Ofer

2016-04-01

Minimization subsurface pollution is much dependent on the capability to provide real-time information on the chemical and hydrological properties of the percolating water. Today, most monitoring programs are based on observation wells that enable data acquisitions from the saturated part of the subsurface. Unfortunately, identification of pollutants in well water is clear evidence that the contaminants already crossed the entire vadose-zone and accumulated in the aquifer water to detectable concentration. Therefore, effective monitoring programs that aim at protecting groundwater from pollution hazard should include vadose zone monitoring technologies that are capable to provide real-time information on the chemical composition of the percolating water. Obviously, identification of pollution process in the vadose zone may provide an early warning on potential risk to groundwater quality, long before contaminates reach the water-table and accumulate in the aquifers. Since productive agriculture must inherently include down leaching of excess lower quality water, understanding the mechanisms controlling transport and degradation of pollutants in the unsaturated is crucial for water resources management. A vadose-zone monitoring system (VMS), which was specially developed to enable continuous measurements of the hydrological and chemical properties of percolating water, was used to assess the impact of various agricultural setups on groundwater quality, including: (a) intensive organic and conventional greenhouses, (b) citrus orchard and open field crops , and (c) dairy farms. In these applications frequent sampling of vadose zone water for chemical and isotopic analysis along with continuous measurement of water content was used to assess the link between agricultural setups and groundwater pollution potential. Transient data on variation in water content along with solute breakthrough at multiple depths were used to calibrate flow and transport models. These models where then used to assess the long term impact of various agricultural setups on the quantity and quality of groundwater recharge. Relevant publications: Turkeltaub et al., WRR. 2016; Turkeltaub et al., J. Hydrol. 2015: Dahan et al., HESS 2014. Baram et al., J. Hydrol. 2012.

A Novel Experimental Setup to Investigate Magnetized Dusty Plasmas

NASA Astrophysics Data System (ADS)

Romero-Talamas, C. A.; Larocque, P.; Alvarez, J.; Sardin, J.

2013-10-01

Progress on the design and construction of a novel experimental setup to investigate dusty plasmas at the University of Maryland, Baltimore County (UMBC) is presented. The setup includes separation adjustability of discharge electrodes and their orientation with respect to gravity without breaking vacuum, and a pair of water-cooled coils to produce magnetic fields with strengths of up to several Tesla. The coils' orientation is also designed to be adjustable with respect to gravity. A pulse-forming network to power the coils with flattop times of several seconds is under design. The setup is mounted inside a large glass bell jar to provide wide optical access to the dusty plasmas, and to minimize interference of chamber walls and mounts with imposed electric or magnetic fields. Planned experiments include crystallization and wave propagation under strong magnetic fields.

Supercritical Water Experimental Setup for µSR

NASA Astrophysics Data System (ADS)

Liu, Guangdong; Chen, Yanggang; Morrison, Alexander H.; Koda, Akihiro; Percival, Paul W.; Ghandi, Khashayar

The Canadian design for Generation IV nuclear reactors uses supercritical water (SCW, water above its critical point of 374 °C, 221 bar (1 bar = 100 kPa)) as the coolant. Supercritical water-cooled reactors (SCWRs) are designed towards sustainability, economic benefits, improved safety, and longer lifespan. Despite the potential advantages of SCWRs, we know very little about the kinetics of radiolysis products that are formed in them because of the limitations of experimental instruments under the extreme conditions of SCW. The radiolysis products can accumulate over time and create a very corrosive environment. Our group has developed and tested an apparatus suitable for muon spin rotation (µSR) studies of water and aqueous solutions up to 550 °C and 250 bar, close to the conditions at the reactor outlet of the proposed Canadian SCWR design (625 °C and 250 bar). The reaction kinetics information obtained from our setup, together with computer simulations, will aid us in developing chemical control strategies to minimize corrosion in SCWRs.

How Significant is the Slope of the Sea-side Boundary for Modelling Seawater Intrusion in Coastal Aquifers?

NASA Astrophysics Data System (ADS)

Walther, Marc; Graf, Thomas; Kolditz, Olaf; Lield, Rudolf; Post, Vincent

2017-04-01

A large number of people live in coastal areas using the available water resources, which in (semi-)arid regions are often taken from groundwater resources as the only sufficient source. Compared to surface water, these usually provide a safe water supply due to the remediation and retention capabilities of the subsurface, their high yield, and potentially longer term stability. With a water withdrawal from a coastal aquifer, coastal water management, however, has to ensure that seawater intrusion is retained in order to keep the water salinity at an acceptable level for all water users (e.g. agriculture, industry, households). Besides monitoring of water levels and saline intrusion, it has become a common practice to use numerical modeling for evaluating the coastal water resources and projecting future scenarios. When applying a model, it is necessary for the simplifications implied during the conceptualization of the setup to include the relevant processes (here variable-density flow and mass transport) and sensitive parameters (for a steady state commonly hydraulic conductivity, density ratio, dispersivity). Additionally, the model's boundary conditions are essential to the simulation results. In order to reduce the number of elements, and thus, the computational burden, one simplification that is made in most regional scale saltwater intrusion applications, is to represent the sea-side boundary with a vertical geometry, contrary to the natural conditions, that usually show a very shallow decent of the interface between the aquifer and the open seawater. We use the scientific open-source modeling toolbox OpenGeoSys [1] to quantify the influence of this simplification on the saline intrusion, submarine groundwater discharge, and groundwater residence times. Using an ensemble of different shelf shapes for a steady state setup, we identified a significant dependency of saline intrusion length on the geometric parameters of the sea-side boundary. Results show that the additional effort to implement a sloped sea-side boundary may have a significant impact for assessing coastal water resources, and its influence may be of a similar magnitude as that of other common uncertainties in numerical modelling. Literature [1] Kolditz, O., Bauer, S., Bilke, L., Böttcher, N., Delfs, J. O., Fischer, T., Görke, U. J., et al. (2012). OpenGeoSys: an open-source initiative for numerical simulation of thermo-hydro-mechanical/chemical (THM/C) processes in porous media. Environmental Earth Sciences, 67(2), 589-599. doi:10.1007/s12665-012-1546-x

Wii mote as hydrological sensor: observation of water level fluctuations

NASA Astrophysics Data System (ADS)

Luxemburg, W.; Hut, R.; Weijs, S.; Hegnauer, M.

2009-12-01

The input device of the Nintendo Wii, the Wii-mote offers scientist a multitude of cheap, high quality sensors; ideal for proof of concept testing. For a specific application, i.e. the water level fluctuation in a floating evaporation pan the Wii-mote was tested as the observing device. It is shown that the controller can observe movements with high enough temporal and spatial resolution of up to 4 infrared LED’s to describe water level movements. Floating pans positioned in lakes and reservoirs better represent open water evaporation than evaporation pans installed on land. On the other hand performing water level measurements in a floating pan is more complicated due to movement of the pan and wave activities in the pan. The Wii-mote was mounted on the side of a standard class A-pan and a float was placed in the middle of the pan, with 4 LED’s on top moving along a fixed bar. The information that the Wii-mote wirelessly sends by blue tooth was captured on a laptop. With a MATLAB routine this data was converted into movement of the LED’s relatively to the controller. The observations show that wave activities are nicely captured with a typical spatial resolution smaller than 0.1 mm in our set-up and a temporal resolution of maximum 100 Hz. A frequency domain filter was applied to the observed datasets to obtain average water levels. In our laboratory setting the pan was placed in a large basin with a wave generator. A constant, but small, rate of water was added to the evaporation pan. The average pan levels from the filtered datasets showed systematically lower levels compared to the level without any wave activities. This is a typical effect of waves that occur in shallow basins. However, the added water with rates up to 5 mm/hour were clearly recognized in the filtered datasets which indicates that the Wii-mote is very well capable as a sensor for water level observations.

River Water Pollution Status and Water Policy Scenario in Ethiopia: Raising Awareness for Better Implementation in Developing Countries.

PubMed

Awoke, Aymere; Beyene, Abebe; Kloos, Helmut; Goethals, Peter L M; Triest, Ludwig

2016-10-01

Despite the increasing levels of pollution in many tropical African countries, not much is known about the strength and weaknesses of policy and institutional frameworks to tackle pollution and ecological status of rivers and their impacts on the biota. We investigated the ecological status of four large river basins using physicochemical water quality parameters and bioindicators by collecting samples from forest, agriculture, and urban landscapes of the Nile, Omo-Gibe, Tekeze, and Awash River basins in Ethiopia. We also assessed the water policy scenario to evaluate its appropriateness to prevent and control pollution. To investigate the level of understanding and implementation of regulatory frameworks and policies related to water resources, we reviewed the policy documents and conducted in-depth interviews of the stakeholders. Physicochemical and biological data revealed that there is significant water quality deterioration at the impacted sites (agriculture, coffee processing, and urban landscapes) compared to reference sites (forested landscapes) in all four basins. The analysis of legal, policy, and institutional framework showed a lack of cooperation between stakeholders, lack of knowledge of the policy documents, absence of enforcement strategies, unavailability of appropriate working guidelines, and disconnected institutional setup at the grass root level to implement the set strategies as the major problems. In conclusion, river water pollution is a growing challenge and needs urgent action to implement intersectoral collaboration for water resource management that will eventually lead toward integrated watershed management. Revision of policy and increasing the awareness and participation of implementers are vital to improve ecological quality of rivers.

A preliminary evaluation of nearhore extreme sea level and wave models for fringing reef environments

NASA Astrophysics Data System (ADS)

Hoeke, R. K.; Reyns, J.; O'Grady, J.; Becker, J. M.; Merrifield, M. A.; Roelvink, J. A.

2016-02-01

Oceanic islands are widely perceived as vulnerable to sea level rise and are characterized by steep nearshore topography and fringing reefs. In such settings, near shore dynamics and (non-tidal) water level variability tends to be dominated by wind-wave processes. These processes are highly sensitive to reef morphology and roughness and to regional wave climate. Thus sea level extremes tend to be highly localized and their likelihood can be expected to change in the future (beyond simple extrapolation of sea level rise scenarios): e.g. sea level rise may increase the effective mean depth of reef crests and flats and ocean acidification and/or increased temperatures may lead to changes in reef structure. The problem is sufficiently complex that analytic or numerical approaches are necessary to estimate current hazards and explore potential future changes. In this study, we evaluate the capacity of several analytic/empirical approaches and phase-averaged and phase-resolved numerical models at sites in the insular tropical Pacific. We consider their ability to predict time-averaged wave setup and instantaneous water level exceedance probability (or dynamic wave run-up) as well as computational cost; where possible, we compare the model results with in situ observations from a number of previous studies. Preliminary results indicate analytic approaches are by far the most computationally efficient, but tend to perform poorly when alongshore straight and parallel morphology cannot be assumed. Phase-averaged models tend to perform well with respect to wave setup in such situations, but are unable to predict processes related to individual waves or wave groups, such as infragravity motions or wave run-up. Phase-resolved models tend to perform best, but come at high computational cost, an important consideration when exploring possible future scenarios. A new approach of combining an unstructured computational grid with a quasi-phase averaged approach (i.e. only phase resolving motions below a frequency cutoff) shows promise as a good compromise between computational efficiency and resolving processes such as wave runup and overtopping in more complex bathymetric situations.

Soil moisture flow and nitrate transport through partially saturated zone considering mobile-immobile approach using 3D tank setup

NASA Astrophysics Data System (ADS)

Tomar, J.; Yadav, B. K.

2016-12-01

The aim of this study is to investigate the soil water flow and nitrate movement through vadose zone considering mobile-immobile approach using large scale three dimensional (3D) tank setup. The three dimensional sand tank setup was fabricated having dimension of 60 cm length, 30 cm width and 60 cm height and embedded with horizontal and vertical layers of sampling ports. The tank was filled with a porous media of average size of 0.5 to 1.0 mm homogeneous and nitrate concentration of 300 mg/l was applied with a distributed constant water flux of 150ml/hr. at the top using a sprinkler system. Pore water samples were collected hourly from the sampling ports and were analyzed using UV-spectrophotometer. The soil hydraulic and solute transport parameters were deduced from the laboratory experiments for simulating the considered 3D domain using the mobile-immobile approach. Soil moisture flow and contaminant transport equations are numerically solved for simulating the nitrate movement in the tank setup. The simulated break through curves (BTC) show the nitrate movement is rapid in mobile region by a factor of 1.2 as compared with the immobile region. The results show that the mobile-immobile approach of predicting solute transport in variably saturated zone can be used effectively in field after getting the required parameters using the laboratory experiments under similar environmental conditions. The high concentration 130 ppm was observed in lateral and transverse axis at 05 cm depth. This results will help in further investigation in field and in implementation of decontamination techniques.

Supporting inland waterway transport on German waterways by operational forecasting services - water-levels, discharges, river ice

NASA Astrophysics Data System (ADS)

Meißner, Dennis; Klein, Bastian; Ionita, Monica; Hemri, Stephan; Rademacher, Silke

2017-04-01

Inland waterway transport (IWT) is an important commercial sector significantly vulnerable to hydrological impacts. River ice and floods limit the availability of the waterway network and may cause considerable damages to waterway infrastructure. Low flows significantly affect IWT's operation efficiency usually several months a year due to the close correlation of (low) water levels / water depths and (high) transport costs. Therefore "navigation-related" hydrological forecasts focussing on the specific requirements of water-bound transport (relevant forecast locations, target parameters, skill characteristics etc.) play a major role in order to mitigate IWT's vulnerability to hydro-meteorological impacts. In light of continuing transport growth within the European Union, hydrological forecasts for the waterways are essential to stimulate the use of the free capacity IWT still offers more consequently. An overview of the current operational and pre-operational forecasting systems for the German waterways predicting water levels, discharges and river ice thickness on various time-scales will be presented. While short-term (deterministic) forecasts have a long tradition in navigation-related forecasting, (probabilistic) forecasting services offering extended lead-times are not yet well-established and are still subject to current research and development activities (e.g. within the EU-projects EUPORIAS and IMPREX). The focus is on improving technical aspects as well as on exploring adequate ways of disseminating and communicating probabilistic forecast information. For the German stretch of the River Rhine, one of the most frequented inland waterways worldwide, the existing deterministic forecast scheme has been extended by ensemble forecasts combined with statistical post-processing modules applying EMOS (Ensemble Model Output Statistics) and ECC (Ensemble Copula Coupling) in order to generate water level predictions up to 10 days and to estimate its predictive uncertainty properly. Additionally for the key locations at the international waterways Rhine, Elbe and Danube three competing forecast approaches are currently tested in a pre-operational set-up in order to generate monthly to seasonal (up to 3 months) forecasts: (1) the well-known Ensemble Streamflow Prediction approach (ensemble based on historical meteorology), (2) coupling hydrological models with post-processed outputs from ECMWF's general circulation model (System 4), and (3) a purely statistical approach based on the stable relationship (teleconnection) of global or regional oceanic, climate and hydrological data with river flows. The current results, still pre-operational, reveal the existence of a valuable predictability of water levels and streamflow also at monthly up to seasonal time-scales along the larger rivers used as waterways in Germany. Last but not least insight into the technical set-up of the aforementioned forecasting systems operated at the Federal Institute of Hydrology, which are based on a Delft-FEWS application, will be given focussing on the step-wise extension of the former system by integrating new components in order to meet the growing needs of the customers and to improve and extend the forecast portfolio for waterway users.

SU-F-T-642: Sub Millimeter Accurate Setup of More Than Three Vertebrae in Spinal SBRT with 6D Couch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, X; Zhao, Z; Yang, J

Purpose: To assess the initial setup accuracy in treating more than 3 vertebral body levels in spinal SBRT using a 6D couch. Methods: We retrospectively analyzed last 20 spinal SBRT patients (4 cervical, 9 thoracic, 7 lumbar/sacrum) treated in our clinic. These patients in customized immobilization device were treated in 1 or 3 fractions. Initial setup used ExacTrac and Brainlab 6D couch to align target within 1 mm and 1 degree, following by a cone beam CT (CBCT) for verification. Our current standard practice allows treating a maximum of three continuous vertebrae. Here we assess the possibility to achieve submore » millimeter setup accuracy for more than three vertebrae by examining the residual error in every slice of CBCT. The CBCT had a range of 17.5 cm, which covered 5 to 9 continuous vertebrae depending on the patient and target location. In the study, CBCT from the 1st fraction treatment was rigidly registered with the planning CT in Pinnacle. The residual setup error of a vertebra was determined by expanding the vertebra contour on the planning CT to be large enough to enclose the corresponding vertebra on CBCT. The margin of the expansion was considered as setup error. Results: Out of the 20 patients analyzed, initial setup accuracy can be achieved within 1 mm for a span of 5 or more vertebrae starting from T2 vertebra to inferior vertebra levels. 2 cervical and 2 upper thoracic patients showed the cervical spine was difficult to achieve sub millimeter accuracy for multi levels without a customized immobilization headrest. Conclusion: If the curvature of spinal columns can be reproduced in customized immobilization device during treatment as simulation, multiple continuous vertebrae can be setup within 1 mm with the use of a 6D couch.« less

Effect of sulfate on the transformation of corrosion scale composition and bacterial community in cast iron water distribution pipes

EPA Science Inventory

The stability of iron corrosion products and the bacterial composition of biofilm in drinking water distribution systems (DWDS) could have great impact on the water safety at the consumer ends. In this work, pipe loops were setup to investigate the transformation characteristics ...

Hydrodynamic response of a fringing coral reef to a rise in mean sea level

NASA Astrophysics Data System (ADS)

Taebi, Soheila; Pattiaratchi, Charitha

2014-07-01

Ningaloo Reef, located along the northwest coast of Australia, is one of the longest fringing coral reefs in the world extending ~300 km. Similar to other fringing reefs, it consists of a barrier reef ~1-6 km offshore with occasional gaps, backed by a shallow lagoon. Wave breaking on the reef generates radiation stress gradients that produces wave setup across the reef and lagoon and mean currents across the reef. A section of Ningaloo Reef at Sandy Bay was chosen as the focus of an intense 6-week field experiment and numerical simulation using the wave model SWAN coupled to the three-dimensional circulation model ROMS. The physics of nearshore processes such as wave breaking, wave setup and mean flow across the reef was investigated in detail by examining the various momentum balances established in the system. The magnitude of the terms and the distance of their peaks from reef edge in the momentum balance were sensitive to the changes in mean sea level, e.g. the wave forces decreased as the mean water depth increased (and hence, wave breaking dissipation was reduced). This led to an increase in the wave power at the shoreline, a slight shift of the surf zone to the lee side of the reef and changes in the intensity of the circulation. The predicted hydrodynamic fields were input into a Lagrangian particle tracking model to estimate the transport time scale of the reef-lagoon system. Flushing time of the lagoon with the open ocean was computed using two definitions in renewal of semi-enclosed water basins and revealed the sensitivity of such a transport time scale to methods. An increase in the lagoon exchange rate at smaller mean sea-level rise and the decrease at higher mean sea-level rise was predicted through flushing time computed using both methods.

Sea Extremes: Integrated impact assessment in coastal climate adaptation

NASA Astrophysics Data System (ADS)

Sorensen, Carlo; Knudsen, Per; Broge, Niels; Molgaard, Mads; Andersen, Ole

2016-04-01

We investigate effects of sea level rise and a change in precipitation pattern on coastal flooding hazards. Historic and present in situ and satellite data of water and groundwater levels, precipitation, vertical ground motion, geology, and geotechnical soil properties are combined with flood protection measures, topography, and infrastructure to provide a more complete picture of the water-related impact from climate change at an exposed coastal location. Results show that future sea extremes evaluated from extreme value statistics may, indeed, have a large impact. The integrated effects from future storm surges and other geo- and hydro-parameters need to be considered in order to provide for the best protection and mitigation efforts, however. Based on the results we present and discuss a simple conceptual model setup that can e.g. be used for 'translation' of regional sea level rise evidence and projections to concrete impact measures. This may be used by potentially affected stakeholders -often working in different sectors and across levels of governance, in a common appraisal of the challenges faced ahead. The model may also enter dynamic tools to evaluate local impact as sea level research advances and projections for the future are updated.

Y-piece temperature and humidification during mechanical ventilation.

PubMed

Solomita, Mario; Daroowalla, Feroza; Leblanc, Deniese S; Smaldone, Gerald C

2009-04-01

Practitioners often presume there is adequate humidification in the ventilator circuit if the Y-piece is at a specified temperature, but control of Y-piece temperature may be inadequate to ensure adequate humidification. In an in vitro bench model we measured water-vapor delivery with several heated humidification setups and a wide range of minute volume (V (E)) values. The setup included a condenser, hygrometry, and thermometer. First, we calibrated the system with a point-source humidifier and water pump. Then we tested the water-vapor delivery during non-heated-wire humidification and during heated-wire humidification with a temperature gradient of +3 degrees C, 0 degrees C, and -3 degrees C between the humidifier and the Y-piece. We compared the results to 2 recommended humidification values: 100% saturated (absolute humidity 44 mg H(2)O/L) gas at 37 degrees C (saturated/37 degrees C); and 75% saturated (absolute humidity 33 mg H(2)O/L), which is the humidity recommended by the International Organization for Standardization (the ISO standard). In all the experiments the setup was set to provide 35 degrees C at the Y-piece. Our method for measuring water-vapor delivery closely approximated the amount delivered by a calibrated pump, but slightly underestimated the water-vapor delivery in all the experiments and the whole V (E) range. At all V (E) values, water-vapor delivery during non-heated-wire humidification matched or exceeded saturated/37 degrees C and was significantly greater than that during heated-wire humidification. During heated-wire humidification, water-vapor delivery varied with the temperature gradient and did not reach saturated/37 degrees C at V (E) > 6 L/min. Water-vapor delivery with the negative temperature gradient was below the ISO standard. Maintaining temperature at one point in the inspiratory circuit (eg, Y-piece), does not ensure adequate water-vapor delivery. Other factors (humidification system, V (E), gradient setting) are critical. At a given temperature, humidification may be significantly higher or lower than expected.

Numerical modeling of the impact of sea-level rise on fringing coral reef hydrodynamics and sediment transport

USGS Publications Warehouse

Storlazzi, C.D.; Elias, E.; Field, M.E.; Presto, M.K.

2011-01-01

Most climate projections suggest that sea level may rise on the order of 0.5-1.0 m by 2100; it is not clear, however, how fluid flow and sediment dynamics on exposed fringing reefs might change in response to this rapid sea-level rise. Coupled hydrodynamic and sediment-transport numerical modeling is consistent with recent published results that suggest that an increase in water depth on the order of 0.5-1.0 m on a 1-2 m deep exposed fringing reef flat would result in larger significant wave heights and setup, further elevating water depths on the reef flat. Larger waves would generate higher near-bed shear stresses, which, in turn, would result in an increase in both the size and the quantity of sediment that can be resuspended from the seabed or eroded from adjacent coastal plain deposits. Greater wave- and wind-driven currents would develop with increasing water depth, increasing the alongshore and offshore flux of water and sediment from the inner reef flat to the outer reef flat and fore reef where coral growth is typically greatest. Sediment residence time on the fringing reef flat was modeled to decrease exponentially with increasing sea-level rise as the magnitude of sea-level rise approached the mean water depth over the reef flat. The model results presented here suggest that a 0.5-1.0 m rise in sea level will likely increase coastal erosion, mixing and circulation, the amount of sediment resuspended, and the duration of high turbidity on exposed reef flats, resulting in decreased light availability for photosynthesis, increased sediment-induced stress on the reef ecosystem, and potentially affecting a number of other ecological processes.

An experimental study of dependence of hydro turbine vibration parameters on pressure pulsations in the flow path

NASA Astrophysics Data System (ADS)

Dekterev, D.; Maslennikova, A.; Abramov, A.

2017-09-01

The operation modes of the hydraulic power plant water turbine with the formation of a precessing vortex core were studied on the hydrodynamic set-up with the model of hydraulic unit. The dependence of low-frequency vibrations on flow pressure pulsations in the hydraulic unit was established. The results of the air injection effect on the vibrational parameters of the hydrodynamic set-up were presented.

Comparison of different statistical methods for estimation of extreme sea levels with wave set-up contribution

NASA Astrophysics Data System (ADS)

Kergadallan, Xavier; Bernardara, Pietro; Benoit, Michel; Andreewsky, Marc; Weiss, Jérôme

2013-04-01

Estimating the probability of occurrence of extreme sea levels is a central issue for the protection of the coast. Return periods of sea level with wave set-up contribution are estimated here in one site : Cherbourg in France in the English Channel. The methodology follows two steps : the first one is computation of joint probability of simultaneous wave height and still sea level, the second one is interpretation of that joint probabilities to assess a sea level for a given return period. Two different approaches were evaluated to compute joint probability of simultaneous wave height and still sea level : the first one is multivariate extreme values distributions of logistic type in which all components of the variables become large simultaneously, the second one is conditional approach for multivariate extreme values in which only one component of the variables have to be large. Two different methods were applied to estimate sea level with wave set-up contribution for a given return period : Monte-Carlo simulation in which estimation is more accurate but needs higher calculation time and classical ocean engineering design contours of type inverse-FORM in which the method is simpler and allows more complex estimation of wave setup part (wave propagation to the coast for example). We compare results from the two different approaches with the two different methods. To be able to use both Monte-Carlo simulation and design contours methods, wave setup is estimated with an simple empirical formula. We show advantages of the conditional approach compared to the multivariate extreme values approach when extreme sea-level occurs when either surge or wave height is large. We discuss the validity of the ocean engineering design contours method which is an alternative when computation of sea levels is too complex to use Monte-Carlo simulation method.

Are annual layers preserved in NorthGRIP Eemian ice?

NASA Astrophysics Data System (ADS)

Kettner, E.; Bigler, M.; Nielsen, M. E.; Steffensen, J. P.; Svensson, A.

2009-04-01

A newly developed setup for continuous flow analysis (CFA) of ice cores in Copenhagen is optimized for high resolution analysis of four components: Soluble sodium (mainly deriving from sea salt), soluble ammonium (related to biological processes and biomass burning events), insoluble dust particles (basically transported from Asian deserts to Greenland), and the electrolytic melt water conductivity (which is a bulk signal for all ionic constituents). Furthermore, we are for the first time implementing a flow cytometer to obtain high quality dust concentration and size distribution profiles based on individual dust particle measurements. Preliminary measurements show that the setup is able to resolve annual layers of 1 cm thickness. Ice flow models predict that annual layers in the Eemian section of the Greenland NorthGRIP ice core (130-115 ka BP) have a thickness of around 1 cm. However, the visual stratigraphy of the ice core indicates that the annual layering in the Eemian section may be disturbed by micro folds and rapid crystal growth. In this case study we will measure the impurity content of an Eemian segment of the NorthGRIP ice core with the new CFA setup. This will allow for a comparison to well-known impurity levels of the Holocene in both Greenland and Antarctic ice and we will attempt to determine if annual layers are still present in the ice.

Modelling rapid subsurface flow at the hillslope scale with explicit representation of preferential flow paths

NASA Astrophysics Data System (ADS)

Wienhöfer, J.; Zehe, E.

2012-04-01

Rapid lateral flow processes via preferential flow paths are widely accepted to play a key role for rainfall-runoff response in temperate humid headwater catchments. A quantitative description of these processes, however, is still a major challenge in hydrological research, not least because detailed information about the architecture of subsurface flow paths are often impossible to obtain at a natural site without disturbing the system. Our study combines physically based modelling and field observations with the objective to better understand how flow network configurations influence the hydrological response of hillslopes. The system under investigation is a forested hillslope with a small perennial spring at the study area Heumöser, a headwater catchment of the Dornbirnerach in Vorarlberg, Austria. In-situ points measurements of field-saturated hydraulic conductivity and dye staining experiments at the plot scale revealed that shrinkage cracks and biogenic macropores function as preferential flow paths in the fine-textured soils of the study area, and these preferential flow structures were active in fast subsurface transport of artificial tracers at the hillslope scale. For modelling of water and solute transport, we followed the approach of implementing preferential flow paths as spatially explicit structures of high hydraulic conductivity and low retention within the 2D process-based model CATFLOW. Many potential configurations of the flow path network were generated as realisations of a stochastic process informed by macropore characteristics derived from the plot scale observations. Together with different realisations of soil hydraulic parameters, this approach results in a Monte Carlo study. The model setups were used for short-term simulation of a sprinkling and tracer experiment, and the results were evaluated against measured discharges and tracer breakthrough curves. Although both criteria were taken for model evaluation, still several model setups produced acceptable matches to the observed behaviour. These setups were selected for long-term simulation, the results of which were compared against water level measurements at two piezometers along the hillslope and the integral discharge response of the spring to reject some non-behavioural model setups and further reduce equifinality. The results of this study indicate that process-based modelling can provide a means to distinguish preferential flow networks on the hillslope scale when complementary measurements to constrain the range of behavioural model setups are available. These models can further be employed as a virtual reality to investigate the characteristics of flow path architectures and explore effective parameterisations for larger scale applications.

Novel Electrochemical Raman Spectroscopy Enabled by Water Immersion Objective.

PubMed

Zeng, Zhi-Cong; Hu, Shu; Huang, Sheng-Chao; Zhang, Yue-Jiao; Zhao, Wei-Xing; Li, Jian-Feng; Jiang, Chaoyang; Ren, Bin

2016-10-04

Electrochemical Raman spectroscopy is a powerful molecular level diagnostic technique for in situ investigation of adsorption and reactions on various material surfaces. However, there is still a big room to improve the optical path to meet the increasing request of higher detection sensitivity and spatial resolution. Herein, we proposed a novel electrochemical Raman setup based on a water immersion objective. It dramatically reduces mismatch of the refractive index in the light path. Consequently, significant improvement in detection sensitivity and spatial resolution has been achieved from both Zemax simulation and the experimental results. Furthermore, the thickness of electrolyte layer could be expanded to 2 mm without any influence on the signal collection. Such a thick electrolyte layer allows a much normal electrochemical response during the spectroelectrochemical investigations of the methanol oxidation.

Quantitative and simultaneous non-invasive measurement of skin hydration and sebum levels

PubMed Central

Ezerskaia, Anna; Pereira, S. F.; Urbach, H. Paul; Verhagen, Rieko; Varghese, Babu

2016-01-01

We report a method on quantitative and simultaneous non-contact in-vivo hydration and sebum measurements of the skin using an infrared optical spectroscopic set-up. The method utilizes differential detection with three wavelengths 1720, 1750, and 1770 nm, corresponding to the lipid vibrational bands that lay “in between” the prominent water absorption bands. We have used an emulsifier containing hydro- and lipophilic components to mix water and sebum in various volume fractions which was applied to the skin to mimic different oily-dry skin conditions. We also measured the skin sebum and hydration values on the forehead under natural conditions and its variations to external stimuli. Good agreement was found between our experimental results and reference values measured using conventional biophysical methods such as Corneometer and Sebumeter. PMID:27375946

The effect of systematic set-up deviations on the absorbed dose distribution for left-sided breast cancer treated with respiratory gating

NASA Astrophysics Data System (ADS)

Edvardsson, A.; Ceberg, S.

2013-06-01

The aim of this study was 1) to investigate interfraction set-up uncertainties for patients treated with respiratory gating for left-sided breast cancer, 2) to investigate the effect of the inter-fraction set-up on the absorbed dose-distribution for the target and organs at risk (OARs) and 3) optimize the set-up correction strategy. By acquiring multiple set-up images the systematic set-up deviation was evaluated. The effect of the systematic set-up deviation on the absorbed dose distribution was evaluated by 1) simulation in the treatment planning system and 2) measurements with a biplanar diode array. The set-up deviations could be decreased using a no action level correction strategy. Not using the clinically implemented adaptive maximum likelihood factor for the gating patients resulted in better set-up. When the uncorrected set-up deviations were simulated the average mean absorbed dose was increased from 1.38 to 2.21 Gy for the heart, 4.17 to 8.86 Gy to the left anterior descending coronary artery and 5.80 to 7.64 Gy to the left lung. Respiratory gating can induce systematic set-up deviations which would result in increased mean absorbed dose to the OARs if not corrected for and should therefore be corrected for by an appropriate correction strategy.

Determination of lead in samples of zooplankton, water, and sediments in a Mexican reservoir: evidence for lead biomagnification in lower/intermediate trophic levels?

PubMed

Rubio-Franchini, Isidoro; Mejía Saavedra, Jesús; Rico-Martínez, Roberto

2008-08-01

We have determined lead concentration of water, sediment, and zooplankton samples of El Niágara, a reservoir in Aguascalientes, Mexico. Our results include the first report of bioconcentration factor (BCF) obtained in an actual ecosystem (as opposed to the experimental setups in the laboratory) for a rotifer species; Asplanchna brigthwellii (BCF ca. 49 300). The BCF of this predatory zooplanktonic species (A. brigthwellii) are up to four times greater than those of two grazing zooplanktonic species (Daphnia similis and Moina micrura). In this contaminated reservoir that lacks fishes, Asplanchna, and Culex sp. together with ducks and other bigger invertebrates might represent the top predators. Our data suggest that biomagnification of lead through at least one trophic level can occur in freshwater systems. Biomagnification in A. brigthwellii might be explained in part by predation of this voracious predator on young of the herbivorous cladoceran, M. micrura. Our findings stand opposite to the current theoretical framework where lead biomagnification occurs only in lower trophic levels.

High-frequency monitoring of water fluxes and nutrient loads to assess the effects of controlled drainage on water storage and nutrient transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rozemeijer, J. C.; Visser, A.; Borren, W.

High nitrogen (N) and phosphorus (P) fluxes from upstream agriculture threaten aquatic ecosystems in surface waters and estuaries, especially in areas characterized by high agricultural N and P inputs and densely drained catchments like the Netherlands. Controlled drainage has been recognized as an effective option to optimize soil moisture conditions for agriculture and to reduce unnecessary losses of fresh water and nutrients. This is achieved by introducing control structures with adjustable overflow levels into subsurface tube drain systems. A small-scale (1 ha) field experiment was designed to investigate the hydrological and chemical changes after introducing controlled drainage. Precipitation rates andmore » the response of water tables and drain fluxes were measured in the periods before the introduction of controlled drainage (2007–2008) and after (2009–2011). For the N and P concentration measurements, auto-analyzers for continuous records were combined with passive samplers for time-averaged concentrations at individual drain outlets. The experimental setup enabled the quantification of changes in the water and solute balance after introducing controlled drainage. The results showed that introducing controlled drainage reduced the drain discharge and increased the groundwater storage in the field. To achieve this, the overflow levels have to be elevated in early spring, before the drain discharge stops due to dryer conditions and falling groundwater levels. The groundwater storage in the field would have been larger if the water levels in the adjacent ditch were controlled as well by an adjustable weir. The N concentrations and loads increased, which was largely related to elevated concentrations in one of the three monitored tube drains. The P loads via the tube drains reduced due to the reduction in discharge after introducing controlled drainage. Furthermore, this may be counteracted by the higher groundwater levels and the larger contribution of N- and P-rich shallow groundwater and overland flow to the surface water.« less

High-frequency monitoring of water fluxes and nutrient loads to assess the effects of controlled drainage on water storage and nutrient transport

DOE PAGES

Rozemeijer, J. C.; Visser, A.; Borren, W.; ...

2016-01-19

High nitrogen (N) and phosphorus (P) fluxes from upstream agriculture threaten aquatic ecosystems in surface waters and estuaries, especially in areas characterized by high agricultural N and P inputs and densely drained catchments like the Netherlands. Controlled drainage has been recognized as an effective option to optimize soil moisture conditions for agriculture and to reduce unnecessary losses of fresh water and nutrients. This is achieved by introducing control structures with adjustable overflow levels into subsurface tube drain systems. A small-scale (1 ha) field experiment was designed to investigate the hydrological and chemical changes after introducing controlled drainage. Precipitation rates andmore » the response of water tables and drain fluxes were measured in the periods before the introduction of controlled drainage (2007–2008) and after (2009–2011). For the N and P concentration measurements, auto-analyzers for continuous records were combined with passive samplers for time-averaged concentrations at individual drain outlets. The experimental setup enabled the quantification of changes in the water and solute balance after introducing controlled drainage. The results showed that introducing controlled drainage reduced the drain discharge and increased the groundwater storage in the field. To achieve this, the overflow levels have to be elevated in early spring, before the drain discharge stops due to dryer conditions and falling groundwater levels. The groundwater storage in the field would have been larger if the water levels in the adjacent ditch were controlled as well by an adjustable weir. The N concentrations and loads increased, which was largely related to elevated concentrations in one of the three monitored tube drains. The P loads via the tube drains reduced due to the reduction in discharge after introducing controlled drainage. Furthermore, this may be counteracted by the higher groundwater levels and the larger contribution of N- and P-rich shallow groundwater and overland flow to the surface water.« less

High-frequency monitoring of water fluxes and nutrient loads to assess the effects of controlled drainage on water storage and nutrient transport

NASA Astrophysics Data System (ADS)

Rozemeijer, J. C.; Visser, A.; Borren, W.; Winegram, M.; van der Velde, Y.; Klein, J.; Broers, H. P.

2016-01-01

High nitrogen (N) and phosphorus (P) fluxes from upstream agriculture threaten aquatic ecosystems in surface waters and estuaries, especially in areas characterized by high agricultural N and P inputs and densely drained catchments like the Netherlands. Controlled drainage has been recognized as an effective option to optimize soil moisture conditions for agriculture and to reduce unnecessary losses of fresh water and nutrients. This is achieved by introducing control structures with adjustable overflow levels into subsurface tube drain systems. A small-scale (1 ha) field experiment was designed to investigate the hydrological and chemical changes after introducing controlled drainage. Precipitation rates and the response of water tables and drain fluxes were measured in the periods before the introduction of controlled drainage (2007-2008) and after (2009-2011). For the N and P concentration measurements, auto-analyzers for continuous records were combined with passive samplers for time-averaged concentrations at individual drain outlets. The experimental setup enabled the quantification of changes in the water and solute balance after introducing controlled drainage. The results showed that introducing controlled drainage reduced the drain discharge and increased the groundwater storage in the field. To achieve this, the overflow levels have to be elevated in early spring, before the drain discharge stops due to dryer conditions and falling groundwater levels. The groundwater storage in the field would have been larger if the water levels in the adjacent ditch were controlled as well by an adjustable weir. The N concentrations and loads increased, which was largely related to elevated concentrations in one of the three monitored tube drains. The P loads via the tube drains reduced due to the reduction in discharge after introducing controlled drainage. However, this may be counteracted by the higher groundwater levels and the larger contribution of N- and P-rich shallow groundwater and overland flow to the surface water.

Ocean modelling and Early-Warning System for the Gulf of Thailand

NASA Astrophysics Data System (ADS)

de Lima Rego, Joao; Yan, Kun; Sisomphon, Piyamarn; Thanathanphon, Watin; Twigt, Daniel; Irazoqui Apecechea, Maialen

2017-04-01

Storm surges associated with severe tropical cyclones are among the most hazardous and damaging natural disasters to coastal areas. The Gulf of Thailand (GoT) has been periodically affected by typhoon induced storm surges in the past (e.g. storm Harriet in 1962, storm Gay in 1989 and storm Linda in 1997). Due to increased touristic / economic development and increased population density in the coastal zone, the combined effect and risk of high water level and increased rainfall / river discharge has dramatically increased and are expected to increase in future due to climate change effects. This presentation describes the development and implementation of the first real-time operational storm surge, wave and wave setup forecasting system in the GoT, a joint applied research initiative by Deltares in The Netherlands and the Hydro and Agro Informatics Institute (HAII) in Thailand. The modelling part includes a new hydrodynamic model to simulate tides and storm surges and two wave models (regional and local). The hydrodynamic model is based on Delft3D Flexible Mesh, capable of simulating water levels and detailed flows. The regional and the recently-developed local wave model are based on the SWAN model, a third-generation wave model. The operational platform is based on Delft-FEWS software, which coordinates all the data inputs, the modelling tasks and the automatic forecast exports including overland inundation in the upper Gulf of Thailand. The main objective of the Gulf of Thailand EWS is to provide daily accurate storm surge, wave and wave setup estimates automatically with various data exports possibilities to support this task. It adds a coastal component to HAII's existing practice of providing daily reports on fluvial flood forecasts, used for decision-support in issuing flood warnings for inland water systems in Thailand. Every day, three-day coastal forecasts are now produced based on the latest regional meteorological predictions. Examples are given to illustrate the system's development and main features, with a focus on decision-support products.

Calibration of a mosfet detection system for 6-MV in vivo dosimetry.

PubMed

Scalchi, P; Francescon, P

1998-03-01

Metal oxide semiconductor field-effect transistor (MOSFET) detectors were calibrated to perform in vivo dosimetry during 6-MV treatments, both in normal setup and total body irradiation (TBI) conditions. MOSFET water-equivalent depth, dependence of the calibration factors (CFs) on the field sizes, MOSFET orientation, bias supply, accumulated dose, incidence angle, temperature, and spoiler-skin distance in TBI setup were investigated. MOSFET reproducibility was verified. The correlation between the water-equivalent midplane depth and the ratio of the exit MOSFET readout divided by the entrance MOSFET readout was studied. MOSFET midplane dosimetry in TBI setup was compared with thermoluminescent dosimetry in an anthropomorphic phantom. By using ionization chamber measurements, the TBI midplane dosimetry was also verified in the presence of cork as a lung substitute. The water-equivalent depth of the MOSFET is about 0.8 mm or 1.8 mm, depending on which sensor side faces the beam. The field size also affects this quantity; Monte Carlo simulations allow driving this behavior by changes in the contaminating electron mean energy. The CFs vary linearly as a function of the square field side, for fields ranging from 5 x 5 to 30 x 30 cm2. In TBI setup, varying the spoiler-skin distance between 5 mm and 10 cm affects the CFs within 5%. The MOSFET reproducibility is about 3% (2 SD) for the doses normally delivered to the patients. The effect of the accumulated dose on the sensor response is negligible. For beam incidence ranging from 0 degrees to 90 degrees, the MOSFET response varies within 7%. No monotonic correlation between the sensor response and the temperature is apparent. Good correlation between the water-equivalent midplane depth and the ratio of the exit MOSFET readout divided by the entrance MOSFET readout was found (the correlation coefficient is about 1). The MOSFET midplane dosimetry relevant to the anthropomorphic phantom irradiation is in agreement with TLD dosimetry within 5%. Ionization chamber and MOSFET midplane dosimetry in inhomogeneous phantoms are in agreement within 2%. MOSFET characteristics are suitable for the in vivo dosimetry relevant to 6-MV treatments, both in normal and TBI setup. The TBI midplane dosimetry using MOSFETs is valid also in the presence of the lung, which is the most critical organ, and allows verifying that calculation of the lung attenuator thicknesses based only on the density is not correct. Our MOSFET dosimetry system can be used also to determine the surface dose by using the water-equivalent depth and extrapolation methods. This procedure depends on the field size used.

Instrumentation and signal processing for the detection of heavy water using off axis-integrated cavity output spectroscopy technique

NASA Astrophysics Data System (ADS)

Gupta, A.; Singh, P. J.; Gaikwad, D. Y.; Udupa, D. V.; Topkar, A.; Sahoo, N. K.

2018-02-01

An experimental setup is developed for the trace level detection of heavy water (HDO) using the off axis-integrated cavity output spectroscopy technique. The absorption spectrum of water samples is recorded in the spectral range of 7190.7 cm-1-7191.5 cm-1 with the diode laser as the light source. From the recorded water vapor absorption spectrum, the heavy water concentration is determined from the HDO and water line. The effect of cavity gain nonlinearity with per pass absorption is studied. The signal processing and data fitting procedure is devised to obtain linear calibration curves by including nonlinear cavity gain effects into the calculation. Initial calibration of mirror reflectivity is performed by measurements on the natural water sample. The signal processing and data fitting method has been validated by the measurement of the HDO concentration in water samples over a wide range from 20 ppm to 2280 ppm showing a linear calibration curve. The average measurement time is about 30 s. The experimental technique presented in this paper could be applied for the development of a portable instrument for the fast measurement of water isotopic composition in heavy water plants and for the detection of heavy water leak in pressurized heavy water reactors.

High level tritiated water monitoring by Bremsstrahlung counting using a silicon drift detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niemes, S.; Sturm, M.; Michling, R.

2015-03-15

The β-ray induced X-ray spectrometry (BIXS) is a promising technique to monitor the tritium concentration in a fuel cycle of a fusion reactor. For in-situ measurements of high level tritiated water by Bremsstrahlung counting, the characteristics of a low-noise silicon drift detector (SDD) have been examined at the Tritium Laboratory Karlsruhe (TLK). In static measurements with constant sample volume and tritium concentration, the Bremsstrahlung spectra of tritiated water samples in a concentration range of 0.02 to 15 MBq/ml have been obtained. The volume has been kept constant at 5 cm{sup 3}. The observed spectra are well above the noise threshold.more » In addition to X-rays induced by β-rays, the spectra feature X-ray fluorescence peaks of the surrounding materials. No indications of memory effects have been observed. A linear relation between the X-ray intensity and the tritium concentration was obtained and the lower detection limit of the setup has been determined to 1 MBq ml{sup -1}, assessed by the Curie criterion. In addition, the spectra obtained experimentally could be reproduced with high agreement by Monte-Carlo simulations using the GEANT4-tool-kit. It was found that the present detection system is applicable to non-invasive measurements of high-level tritiated water and the SDD is a convenient tool to detect the low energy Bremsstrahlung X-rays. (authors)« less

An innovative experimental setup for Large Scale Particle Image Velocimetry measurements in riverine environments

NASA Astrophysics Data System (ADS)

Tauro, Flavia; Olivieri, Giorgio; Porfiri, Maurizio; Grimaldi, Salvatore

2014-05-01

Large Scale Particle Image Velocimetry (LSPIV) is a powerful methodology to nonintrusively monitor surface flows. Its use has been beneficial to the development of rating curves in riverine environments and to map geomorphic features in natural waterways. Typical LSPIV experimental setups rely on the use of mast-mounted cameras for the acquisition of natural stream reaches. Such cameras are installed on stream banks and are angled with respect to the water surface to capture large scale fields of view. Despite its promise and the simplicity of the setup, the practical implementation of LSPIV is affected by several challenges, including the acquisition of ground reference points for image calibration and time-consuming and highly user-assisted procedures to orthorectify images. In this work, we perform LSPIV studies on stream sections in the Aniene and Tiber basins, Italy. To alleviate the limitations of traditional LSPIV implementations, we propose an improved video acquisition setup comprising a telescopic, an inexpensive GoPro Hero 3 video camera, and a system of two lasers. The setup allows for maintaining the camera axis perpendicular to the water surface, thus mitigating uncertainties related to image orthorectification. Further, the mast encases a laser system for remote image calibration, thus allowing for nonintrusively calibrating videos without acquiring ground reference points. We conduct measurements on two different water bodies to outline the performance of the methodology in case of varying flow regimes, illumination conditions, and distribution of surface tracers. Specifically, the Aniene river is characterized by high surface flow velocity, the presence of abundant, homogeneously distributed ripples and water reflections, and a meagre number of buoyant tracers. On the other hand, the Tiber river presents lower surface flows, isolated reflections, and several floating objects. Videos are processed through image-based analyses to correct for lens distortions and analyzed with a commercially available PIV software. Surface flow velocity estimates are compared to supervised measurements performed by visually tracking objects floating on the stream surface and to rating curves developed by the Ufficio Idrografico e Mareografico (UIM) at Regione Lazio, Italy. Experimental findings demonstrate that the presence of tracers is crucial for surface flow velocity estimates. Further, considering surface ripples and patterns may lead to underestimations in LSPIV analyses.

Surface forces between colloidal particles at high hydrostatic pressure

NASA Astrophysics Data System (ADS)

Pilat, D. W.; Pouligny, B.; Best, A.; Nick, T. A.; Berger, R.; Butt, H.-J.

2016-02-01

It was recently suggested that the electrostatic double-layer force between colloidal particles might weaken at high hydrostatic pressure encountered, for example, in deep seas or during oil recovery. We have addressed this issue by means of a specially designed optical trapping setup that allowed us to explore the interaction of a micrometer-sized glass bead and a solid glass wall in water at hydrostatic pressures of up to 1 kbar. The setup allowed us to measure the distance between bead and wall with a subnanometer resolution. We have determined the Debye lengths in water for salt concentrations of 0.1 and 1 mM. We found that in the pressure range from 1 bar to 1 kbar the maximum variation of the Debye lengths was <1 nm for both salt concentrations. Furthermore, the magnitude of the zeta potentials of the glass surfaces in water showed no dependency on pressure.

Water Cooled Mirror Design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dale, Gregory E.; Holloway, Michael Andrew; Pulliam, Elias Noel

2015-03-30

This design is intended to replace the current mirror setup being used for the NorthStar Moly 99 project in order to monitor the target coupon. The existing setup has limited movement for camera alignment and is difficult to align properly. This proposed conceptual design for a water cooled mirror will allow for greater thermal transfer between the mirror and the water block. It will also improve positioning of the mirror by using flexible vacuum hosing and a ball head joint capable of a wide range of motion. Incorporating this design into the target monitoring system will provide more efficient coolingmore » of the mirror which will improve the amount of diffraction caused by the heating of the mirror. The process of aligning the mirror for accurate position will be greatly improved by increasing the range of motion by offering six degrees of freedom.« less

SU-E-J-55: End-To-End Effectiveness Analysis of 3D Surface Image Guided Voluntary Breath-Holding Radiotherapy for Left Breast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, M; Feigenberg, S

Purpose To evaluate the effectiveness of using 3D-surface-image to guide breath-holding (BH) left-side breast treatment. Methods Two 3D surface image guided BH procedures were implemented and evaluated: normal-BH, taking BH at a comfortable level, and deep-inspiration-breath-holding (DIBH). A total of 20 patients (10 Normal-BH and 10 DIBH) were recruited. Patients received a BH evaluation using a commercialized 3D-surface- tracking-system (VisionRT, London, UK) to quantify the reproducibility of BH positions prior to CT scan. Tangential 3D/IMRT plans were conducted. Patients were initially setup under free-breathing (FB) condition using the FB surface obtained from the untaged CT to ensure a correct patientmore » position. Patients were then guided to reach the planned BH position using the BH surface obtained from the BH CT. Action-levels were set at each phase of treatment process based on the information provided by the 3D-surface-tracking-system for proper interventions (eliminate/re-setup/ re-coaching). We reviewed the frequency of interventions to evaluate its effectiveness. The FB-CBCT and port-film were utilized to evaluate the accuracy of 3D-surface-guided setups. Results 25% of BH candidates with BH positioning uncertainty > 2mm are eliminated prior to CT scan. For >90% of fractions, based on the setup deltas from3D-surface-trackingsystem, adjustments of patient setup are needed after the initial-setup using laser. 3D-surface-guided-setup accuracy is comparable as CBCT. For the BH guidance, frequency of interventions (a re-coaching/re-setup) is 40%(Normal-BH)/91%(DIBH) of treatments for the first 5-fractions and then drops to 16%(Normal-BH)/46%(DIBH). The necessity of re-setup is highly patient-specific for Normal-BH but highly random among patients for DIBH. Overall, a −0.8±2.4 mm accuracy of the anterior pericardial shadow position was achieved. Conclusion 3D-surface-image technology provides effective intervention to the treatment process and ensures favorable day-to-day setup accuracy. DIBH setup appears to be more uncertain and this would be the patient group who will definitely benefit from the extra information of 3D surface setup.« less

Time-of-Flight Measurement of the Speed of Sound in Water

ERIC Educational Resources Information Center

Ganci, Salvatore

2016-01-01

A simple setup is designed to investigate a "time-of-flight" measurement of the speed of sound in water. This experiment only requires low cost components and is also very simple to understand by students. It could be easily used as a demonstration experiment.

A Monte Carlo simulation and setup optimization of output efficiency to PGNAA thermal neutron using 252Cf neutrons

NASA Astrophysics Data System (ADS)

Zhang, Jin-Zhao; Tuo, Xian-Guo

2014-07-01

We present the design and optimization of a prompt γ-ray neutron activation analysis (PGNAA) thermal neutron output setup based on Monte Carlo simulations using MCNP5 computer code. In these simulations, the moderator materials, reflective materials, and structure of the PGNAA 252Cf neutrons of thermal neutron output setup are optimized. The simulation results reveal that the thin layer paraffin and the thick layer of heavy water moderating effect work best for the 252Cf neutron spectrum. Our new design shows a significantly improved performance of the thermal neutron flux and flux rate, that are increased by 3.02 times and 3.27 times, respectively, compared with the conventional neutron source design.

Modeling flow and solute transport at a tile drain field site by explicit representation of preferential flow structures: Equifinality and uncertainty

NASA Astrophysics Data System (ADS)

Zehe, E.; Klaus, J.

2011-12-01

Rapid flow in connected preferential flow paths is crucial for fast transport of water and solutes through soils, especially at tile drained field sites. The present study tests whether an explicit treatment of worm burrows is feasible for modeling water flow, bromide and pesticide transport in structured heterogeneous soils with a 2-dimensional Richards based model. The essence is to represent worm burrows as morphologically connected paths of low flow resistance and low retention capacity in the spatially highly resolved model domain. The underlying extensive database to test this approach was collected during an irrigation experiment, which investigated transport of bromide and the herbicide Isoproturon at a 900 sqm tile drained field site. In a first step we investigated whether the inherent uncertainty in key data causes equifinality i.e. whether there are several spatial model setups that reproduce tile drain event discharge in an acceptable manner. We found a considerable equifinality in the spatial setup of the model, when key parameters such as the area density of worm burrows and the maximum volumetric water flows inside these macropores were varied within the ranges of either our measurement errors or measurements reported in the literature. Thirteen model runs yielded a Nash-Sutcliffe coefficient of more than 0.9. Also, the flow volumes were in good accordance and peak timing errors where less than or equal to 20 min. In the second step we investigated thus whether this "equifinality" in spatial model setups may be reduced when including the bromide tracer data into the model falsification process. We simulated transport of bromide for the 13 spatial model setups, which performed best with respect to reproduce tile drain event discharge, without any further calibration. Four of this 13 model setups allowed to model bromide transport within fixed limits of acceptability. Parameter uncertainty and equifinality could thus be reduced. Thirdly, we selected one of those four setups for simulating transport of Isoproturon, which was applied the day before the irrigation experiment, and tested different parameter combinations to characterise adsorption according to the footprint data base. Simulations could, however, only reproduce the observed event based leaching behaviour, when we allowed for retardation coefficients that were very close to one. This finding is consistent with observations various field observations. We conclude: a) A realistic representation of dominating structures and their topology is of key importance for predicting preferential water and mass flows at tile drained hillslopes. b) Parameter uncertainty and equifinality could be reduced, but a system inherent equifinality in a 2-dimensional Richards based model has to be accepted.

Sulfur Speciation and Extraction in Jet A (Briefing Charts)

DTIC Science & Technology

2015-08-16

Extraction fluid: denatured ethanol from Fisher Scientific and deionized water – Jet A fuel , approximately 500-800 ppm sulfur by weight – Data...Outline • Background • Experimental Setup – Extraction of sulfur compounds from fuel to alcohol/water extraction fluid – Each rinse is...Hydrophobic / Oleophillic Membrane Oleophobic / Hydrophillic Membrane Emulsion Phase Fuel Phase Water (Extraction Fluid) Phase DISTRIBUTION A

Using Pneumatics to Perform Laboratory Hydraulic Conductivity Tests on Gravel with Underdamped Responses

NASA Astrophysics Data System (ADS)

Judge, A. I.

2011-12-01

A permeameter has been designed and built to perform laboratory hydraulic conductivity tests on various kinds of gravel samples with hydraulic conductivity values ranging from 0.1 to 1 m/s. The tests are commenced by applying 200 Pa of pneumatic pressure to the free surface of the water column in a riser connected above a cylinder that holds large gravel specimens. This setup forms a permeameter specially designed for these tests which is placed in a barrel filled with water, which acts as a reservoir. The applied pressure depresses the free surface in the riser 2 cm until it is instantly released by opening a ball valve. The water then flows through the base of the cylinder and the specimen like a falling head test, but the water level oscillates about the static value. The water pressure and the applied air pressure in the riser are measured with vented pressure transducers at 100 Hz. The change in diameter lowers the damping frequency of the fluctuations of the water level in the riser, which allows for underdamped responses to be observed for all tests. The results of tests without this diameter change would otherwise be a series of critically damped responses with only one or two oscillations that dampen within seconds and cannot be evaluated with equations for the falling head test. The underdamped responses oscillate about the static value at about 1 Hz and are very sensitive to the hydraulic conductivity of all the soils tested. These fluctuations are also very sensitive to the inertia and friction in the permeameter that are calculated considering the geometry of the permeameter and verified experimentally. Several gravel specimens of various shapes and sizes are tested that show distinct differences in water level fluctuations. The friction of the system is determined by calibrating the model with the results of tests performed where the cylinder had no soil in it. The calculation of the inertia in the response of the water column for the typical testing setup was also verified by performing tests without soil. The friction coefficient of the cylinder base below the specimen where the water enters and exits throughout the test has a minor loss which is determined by analyzing these results. The hydraulic conductivity is then calculated by calculating the friction of the system and subtracting the friction loss from the frictional component of the damping frequency calibrated to the measured data for each test. This allows for a very precise and accurate calculation of the hydraulic conductivity of the soil tested because the closed form analytical model developed and used considers the underdamped responses which fit to the measured data unique to every test more easily than any other method. The average error in predicting the head values for preliminary results is 1 mm, or about 4% of the initial displacement for all tests.

Biogas from mesophilic digestion of cow dung using charcoal and gelatin as additives

NASA Astrophysics Data System (ADS)

Islam, Md Rashedul; Salam, Bodius; Rahman, Md Mizanur; Mamun, Abdullah Al

2017-06-01

Biogas, a source of renewable energy is produced from bacteria in the process of biodegradation of organic matter under anaerobic conditions. A research work was performed to find out the production of biogas from cow dung using charcoal and gelatin as additives. Five laboatory scale experimental set-up were constructed using 0, 0.2, 0.4, 0.6 and 0.8% gelatin with cow dung as additive to perform the research work. For all the set-up 0.5% charcoal was also added. All the set-ups were made from 1-liter capacity conical flask. The amount of water and cow dung was used respectively 382 gm. and 318 gm. in every set-up. Total solid content was maintained 8% throughout all set-ups. The digesters were operated at ambient temperature of 26°-32°C. The total gas yield without using gelatin additive was found to be 12 L/kg cow dung. The maximum gas yield was found from 0.2% gelatin additive and 23% more as compared to without gelatin gas production. The retention time varied from 28 to 79 days for the experiments.

Constructing a strategic, national resource: European policies and the up-scaling of water services in the Algarve, Portugal.

PubMed

Thiel, Andreas

2010-07-01

Water management has been significantly reshaped throughout recent decades in Europe and worldwide. Vivid examples of this restructuring include Southern European coastal zones which have been transformed into the European "pleasure periphery" over the last 40 years, requiring significant changes in water service provision. Taking it as an illustrative case of the Southern European coastal freshwater crisis and the way different European Member States have dealt with it, the article provides an account of the Algarve, indicative of typical Portuguese dynamics, and compares it with developments in other European countries. Expanding demands on water services in this region led to a crisis situation throughout the nineties, which was resolved by shifting physical infrastructures and competencies to the supra-local level. The re-scaling of water management was instrumental to expanding national control over the sector at the expense of local authorities and privatization. The national level used European funds and regulations to re-configure the institutional and infrastructure set-up in order to provide for tourism and agricultural expansion. Quality tourism was constructed as a decentral, hegemonic state spatial project, with the Algarvian's entire water resource base being put at its disposal. The solution found illustrates a modified version of the supply side and surface water oriented "hydraulic paradigm" in Portugal: geared towards tourism and urban areas and the maintenance of irrigation agriculture. Delays in infrastructures, ideological preferences, maintaining national control over strategic water services and territoriality contributed towards the construction of water services as part of this hegemonic state spatial strategy for tourism expansion.

Constructing a Strategic, National Resource: European Policies and the Up-Scaling of Water Services in the Algarve, Portugal

NASA Astrophysics Data System (ADS)

Thiel, Andreas

2010-07-01

Water management has been significantly reshaped throughout recent decades in Europe and worldwide. Vivid examples of this restructuring include Southern European coastal zones which have been transformed into the European “pleasure periphery” over the last 40 years, requiring significant changes in water service provision. Taking it as an illustrative case of the Southern European coastal freshwater crisis and the way different European Member States have dealt with it, the article provides an account of the Algarve, indicative of typical Portuguese dynamics, and compares it with developments in other European countries. Expanding demands on water services in this region led to a crisis situation throughout the nineties, which was resolved by shifting physical infrastructures and competencies to the supra-local level. The re-scaling of water management was instrumental to expanding national control over the sector at the expense of local authorities and privatization. The national level used European funds and regulations to re-configure the institutional and infrastructure set-up in order to provide for tourism and agricultural expansion. Quality tourism was constructed as a decentral, hegemonic state spatial project, with the Algarvian’s entire water resource base being put at its disposal. The solution found illustrates a modified version of the supply side and surface water oriented “hydraulic paradigm” in Portugal: geared towards tourism and urban areas and the maintenance of irrigation agriculture. Delays in infrastructures, ideological preferences, maintaining national control over strategic water services and territoriality contributed towards the construction of water services as part of this hegemonic state spatial strategy for tourism expansion.

Humidity scanning quartz crystal microbalance with dissipation monitoring setup for determination of sorption-desorption isotherms and rheological changes

NASA Astrophysics Data System (ADS)

Björklund, Sebastian; Kocherbitov, Vitaly

2015-05-01

A new method to determine water sorption-desorption isotherms with high resolution in the complete range of water activities (relative humidities) is presented. The method is based on quartz crystal microbalance with dissipation monitoring (QCM-D). The QCM-D is equipped with a humidity module in which the sample film is kept in air with controlled humidity. The experimental setup allows for continuous scanning of the relative humidity from either dry to humid conditions or vice versa. The amount of water sorbed or desorbed from the sample is determined from the resonance frequencies of the coated quartz sensor, via analysis of the overtone dependence. In addition, the method allows for characterization of hydration induced changes of the rheological properties from the dissipation data, which is closely connected to the viscoelasticity of the film. The accuracy of the humidity scanning setup is confirmed in control experiments. Sorption-desorption isotherms of pig gastric mucin and lysozyme, obtained by the new method, show good agreement with previous results. Finally, we show that the deposition technique used to coat the quartz sensor influences the QCM-D data and how this issue can be used to obtain further information on the effect of hydration. In particular, we demonstrate that spin-coating represents an attractive alternative to obtain sorption-desorption isotherms, while drop-coating provides additional information on changes of the rheological properties during hydration.

Nearshore Tsunami Inundation Model Validation: Toward Sediment Transport Applications

USGS Publications Warehouse

Apotsos, Alex; Buckley, Mark; Gelfenbaum, Guy; Jaffe, Bruce; Vatvani, Deepak

2011-01-01

Model predictions from a numerical model, Delft3D, based on the nonlinear shallow water equations are compared with analytical results and laboratory observations from seven tsunami-like benchmark experiments, and with field observations from the 26 December 2004 Indian Ocean tsunami. The model accurately predicts the magnitude and timing of the measured water levels and flow velocities, as well as the magnitude of the maximum inundation distance and run-up, for both breaking and non-breaking waves. The shock-capturing numerical scheme employed describes well the total decrease in wave height due to breaking, but does not reproduce the observed shoaling near the break point. The maximum water levels observed onshore near Kuala Meurisi, Sumatra, following the 26 December 2004 tsunami are well predicted given the uncertainty in the model setup. The good agreement between the model predictions and the analytical results and observations demonstrates that the numerical solution and wetting and drying methods employed are appropriate for modeling tsunami inundation for breaking and non-breaking long waves. Extension of the model to include sediment transport may be appropriate for long, non-breaking tsunami waves. Using available sediment transport formulations, the sediment deposit thickness at Kuala Meurisi is predicted generally within a factor of 2.

Acoustic Noise Levels of Dental Equipments and Its Association with Fear and Annoyance Levels among Patients Attending Different Dental Clinic Setups in Jaipur, India

PubMed Central

Ganta, Shravani; Nagaraj, Anup; Pareek, Sonia; Atri, Mansi; Singh, Kushpal; Sidiq, Mohsin

2014-01-01

Background: Noise is a source of pervasive occupational hazard for practicing dentists and the patients. The sources of dental sounds by various dental equipments can pose as a potential hazard to hearing system and add to the annoyance levels of the patients. The aim of the study was to analyze the noise levels from various equipments and evaluate the effect of acoustic noise stimulus on dental fear and annoyance levels among patients attending different dental clinic setups in Jaipur, India. Methodology: The sampling frame comprised of 180 patients, which included 90 patients attending 10 different private clinics and 90 patients attending a Dental College in Jaipur. The levels of Acoustic Noise Stimulus originating from different equipments were determined using a precision sound level meter/decibulometer. Dental fear among patients was measured using Dental Fear Scale (DFS). Results: Statistical analysis was performed using chi square test and unpaired t-test. The mean background noise levels were found to be maximum in the pre-clinical setup/ laboratory areas (69.23+2.20). Females and the patients attending dental college setup encountered more fear on seeing the drill as compared to the patients attending private clinics (p<0.001). Conclusion: The sources of dental sounds can pose as a potential hazard to hearing system. It was analyzed that the environment in the clinics can directly have an effect on the fear and annoyance levels of patients. Hence it is necessary control the noise from various dental equipments to reduce the fear of patients from visiting a dental clinic. PMID:24959512

Integrative monitoring of water storage variations at the landscape-scale with an iGrav superconducting gravimeter in a field enclosure

NASA Astrophysics Data System (ADS)

Guntner, A.; Reich, M.; Mikolaj, M.; Creutzfeldt, B.; Schroeder, S.; Wziontek, H.

2017-12-01

In spite of the fundamental role of the landscape water balance for the Earth's water and energy cycles, monitoring the water balance and related storage dynamics beyond the point scale is notoriously difficult due to the multitude of flow and storage processes and their spatial heterogeneity. We present the first outdoor deployment of an iGrav superconducting gravimeter (SG) in a minimized field enclosure on a wet-temperate grassland site for integrative monitoring of water storage changes. It is shown that the system performs similarly precise as SGs that have hitherto been deployed in observatory buildings, but with higher sensitivity to hydrological variations in the surroundings of the instrument. Gravity variations observed by the field setup are almost independent of the depth below the terrain surface where water storage changes occur, and thus the field SG system directly observes the total water storage change in an integrative way. We provide a framework to single out the water balance components actual evapotranspiration and lateral subsurface discharge from the gravity time series on annual to daily time scales. With about 99% and 85% of the gravity signal originating within a radius of 4000 and 200 meter around the instrument, respectively, the setup paves the road towards gravimetry as a continuous hydrological field monitoring technique for water storage dynamics at the landscape scale.

Stereoscopic Feature Tracking System for Retrieving Velocity of Surface Waters

NASA Astrophysics Data System (ADS)

Zuniga Zamalloa, C. C.; Landry, B. J.

2017-12-01

The present work is concerned with the surface velocity retrieval of flows using a stereoscopic setup and finding the correspondence in the images via feature tracking (FT). The feature tracking provides a key benefit of substantially reducing the level of user input. In contrast to other commonly used methods (e.g., normalized cross-correlation), FT does not require the user to prescribe interrogation window sizes and removes the need for masking when specularities are present. The results of the current FT methodology are comparable to those obtained via Large Scale Particle Image Velocimetry while requiring little to no user input which allowed for rapid, automated processing of imagery.

Simultaneous measurements of water optical properties by AC9 transmissometer and ASP-15 inherent optical properties meter in Lake Baikal

NASA Astrophysics Data System (ADS)

Balkanov, V.; Belolaptikov, I.; Bezrukov, L.; Budnev, N.; Capone, A.; Chensky, A.; Danilchenko, I.; Domogatsky, G.; Dzhilkibaev, Zh.-A.; Fialkovsky, S.; Gaponenko, O.; Gress, O.; Gress, T.; Il'Yasov, R.; Klabukov, A.; Klimov, A.; Klimushin, S.; Konischev, K.; Koshechkin, A.; Kuznetzov, Vy.; Kuzmichev, L.; Kulepov, V.; Lubsandorzhiev, B.; Masullo, R.; Migneco, E.; Mikheyev, S.; Milenin, M.; Mirgazov, R.; Moseiko, N.; Osipova, E.; Panfilov, A.; Pan'kov, L.; Parfenov, Yu.; Pavlov, A.; Petruccetti, M.; Pliskovsky, E.; Pokhil, P.; Poleschuk, V.; Popova, E.; Prosin, V.; Riccobene, G.; Rozanov, M.; Rubtzov, V.; Semeney, Yu.; Spiering, Ch.; Streicher, O.; Tarashansky, B.; Vasiljev, R.; Wischnewski, R.; Yashin, I.; Zhukov, V.

2003-02-01

Measurements of optical properties in media enclosing Cherenkov neutrino telescopes are important not only at the moment of the selection of an adequate site, but also for the continuous characterization of the medium as a function of time. Over the two last decades, the Baikal collaboration has been measuring the optical properties of the deep water in Lake Baikal (Siberia) where, since April 1998, the neutrino telescope NT-200 is in operation. Measurements have been made with custom devices. The NEMO Collaboration, aiming at the construction of a km3 Cherenkov neutrino detector in the Mediterranean Sea, has developed an experimental setup for the measurement of oceanographic and optical properties of deep sea water. This setup is based on a commercial transmissometer. During a joint campaign of the two collaborations in March and April 2001, light absorption, scattering and attenuation in water have been measured. The results are compatible with previous ones reported by the Baikal Collaboration and show convincing agreement between the two experimental techniques.

New large solar photocatalytic plant: set-up and preliminary results.

PubMed

Malato, S; Blanco, J; Vidal, A; Fernández, P; Cáceres, J; Trincado, P; Oliveira, J C; Vincent, M

2002-04-01

A European industrial consortium called SOLARDETOX has been created as the result of an EC-DGXII BRITE-EURAM-III-financed project on solar photocatalytic detoxification of water. The project objective was to develop a simple, efficient and commercially competitive water-treatment technology, based on compound parabolic collectors (CPCs) solar collectors and TiO2 photocatalysis, to make possible easy design and installation. The design, set-up and preliminary results of the main project deliverable, the first European industrial solar detoxification treatment plant, is presented. This plant has been designed for the batch treatment of 2 m3 of water with a 100 m2 collector-aperture area and aqueous aerated suspensions of polycrystalline TiO2 irradiated by sunlight. Fully automatic control reduces operation and maintenance manpower. Plant behaviour has been compared (using dichloroacetic acid and cyanide at 50 mg l(-1) initial concentration as model compounds) with the small CPC pilot plants installed at the Plataforma Solar de Almería several years ago. The first results with high-content cyanide (1 g l(-1)) waste water are presented and plant treatment capacity is calculated.

Set Up of an Automatic Water Quality Sampling System in Irrigation Agriculture

PubMed Central

Heinz, Emanuel; Kraft, Philipp; Buchen, Caroline; Frede, Hans-Georg; Aquino, Eugenio; Breuer, Lutz

2014-01-01

We have developed a high-resolution automatic sampling system for continuous in situ measurements of stable water isotopic composition and nitrogen solutes along with hydrological information. The system facilitates concurrent monitoring of a large number of water and nutrient fluxes (ground, surface, irrigation and rain water) in irrigated agriculture. For this purpose we couple an automatic sampling system with a Wavelength-Scanned Cavity Ring Down Spectrometry System (WS-CRDS) for stable water isotope analysis (δ2H and δ18O), a reagentless hyperspectral UV photometer (ProPS) for monitoring nitrate content and various water level sensors for hydrometric information. The automatic sampling system consists of different sampling stations equipped with pumps, a switch cabinet for valve and pump control and a computer operating the system. The complete system is operated via internet-based control software, allowing supervision from nearly anywhere. The system is currently set up at the International Rice Research Institute (Los Baños, The Philippines) in a diversified rice growing system to continuously monitor water and nutrient fluxes. Here we present the system's technical set-up and provide initial proof-of-concept with results for the isotopic composition of different water sources and nitrate values from the 2012 dry season. PMID:24366178

Process connectivity in a naturally prograding river delta

NASA Astrophysics Data System (ADS)

Sendrowski, Alicia; Passalacqua, Paola

2017-03-01

River deltas are lowland systems that can display high hydrological connectivity. This connectivity can be structural (morphological connections), functional (control of fluxes), and process connectivity (information flow from system drivers to sinks). In this work, we quantify hydrological process connectivity in Wax Lake Delta, coastal Louisiana, by analyzing couplings among external drivers (discharge, tides, and wind) and water levels recorded at five islands and one channel over summer 2014. We quantify process connections with information theory, a branch of mathematics concerned with the communication of information. We represent process connections as a network; variables serve as network nodes and couplings as network links describing the strength, direction, and time scale of information flow. Comparing process connections at long (105 days) and short (10 days) time scales, we show that tides exhibit daily synchronization with water level, with decreasing strength from downstream to upstream, and that tides transfer information as tides transition from spring to neap. Discharge synchronizes with water level and the time scale of its information transfer compares well to physical travel times through the system, computed with a hydrodynamic model. Information transfer and physical transport show similar spatial patterns, although information transfer time scales are larger than physical travel times. Wind events associated with water level setup lead to increased process connectivity with highly variable information transfer time scales. We discuss the information theory results in the context of the hydrologic behavior of the delta, the role of vegetation as a connector/disconnector on islands, and the applicability of process networks as tools for delta modeling results.

A user-friendly software package to ease the use of VIC hydrologic model for practitioners

NASA Astrophysics Data System (ADS)

Wi, S.; Ray, P.; Brown, C.

2016-12-01

The VIC (Variable Infiltration Capacity) hydrologic and river routing model simulates the water and energy fluxes that occur near the land surface and provides users with useful information regarding the quantity and timing of available water at points of interest within the basin. However, despite its popularity (proved by numerous applications in the literature), its wider adoption is hampered by the considerable effort required to prepare model inputs; e.g., input files storing spatial information related to watershed topography, soil properties, and land cover. This study presents a user-friendly software package (named VIC Setup Toolkit) developed within the MATLAB (matrix laboratory) framework and accessible through an intuitive graphical user interface. The VIC Setup Toolkit enables users to navigate the model building process confidently through prompts and automation, with an intention to promote the use of the model for both practical and academic purposes. The automated processes include watershed delineation, climate and geographical input set-up, model parameter calibration, graph generation and output evaluation. We demonstrate the package's usefulness in various case studies with the American River, Oklahoma River, Feather River and Zambezi River basins.

Illumination-parameter adjustable and illumination-distribution visible LED helmet for low-level light therapy on brain injury

NASA Astrophysics Data System (ADS)

Wang, Pengbo; Gao, Yuan; Chen, Xiao; Li, Ting

2016-03-01

Low-level light therapy (LLLT) has been clinically applied. Recently, more and more cases are reported with positive therapeutic effect by using transcranial light emitting diodes (LEDs) illumination. Here, we developed a LLLT helmet for treating brain injuries based on LED arrays. We designed the LED arrays in circle shape and assembled them in multilayered 3D printed helmet with water-cooling module. The LED arrays can be adjust to touch the head of subjects. A control circuit was developed to drive and control the illumination of the LLLT helmet. The software portion provides the control of on and off of each LED arrays, the setup of illumination parameters, and 3D distribution of LLLT light dose in human subject according to the illumination setups. This LLLT light dose distribution was computed by a Monte Carlo model for voxelized media and the Visible Chinese Human head dataset and displayed in 3D view at the background of head anatomical structure. The performance of the whole system was fully tested. One stroke patient was recruited in the preliminary LLLT experiment and the following neuropsychological testing showed obvious improvement in memory and executive functioning. This clinical case suggested the potential of this Illumination-parameter adjustable and illuminationdistribution visible LED helmet as a reliable, noninvasive, and effective tool in treating brain injuries.

A concept to transfer a therapeutic splint position into permanent occlusion with a customized lingual appliance.

PubMed

Sachse, Tina; Schwestka-Polly, Rainer; Flieger, Stefanie; Wiechmann, Dirk

2012-05-21

The role of occlusion concerning temporomandibular disorder is still unclear but seems to be the only component of the stomathognathic system dentists are able to change morphologically. The aim of the paper is to describe the orthodontist's approach for transferring and maintaining a therapeutic splint position into permanent occlusion using a fully customized lingual appliance. Fixed acrylic bite planes on lower molars were used to maintain a symptom-free condyle position prior to orthodontic treatment. Silicone impressions of the arches including the fixed bite planes were used for the Incognito laboratory procedure. Two digital setups were made. One setup represents the target occlusion. A second setup including the bite planes was used to fabricate an additional set of lower molar brackets. In the leveling stage all teeth except the lower molars were settled to maintain the therapeutic condyle position. Finally, the fixed bite planes were stepwise removed and molar brackets were replaced to establish the permanent occlusion planned with the first setup. The advantage of an individual lingual appliance consists in the high level of congruence between the fabricated setups and the final clinical result. Both the individual scope for design and the precision of the appliance were vitally important in the treatment of a patient with a functional disorder of the masticatory system.

The effects of ocean circulation on ocean-ice interaction and potential feedbacks in an idealized shelf cavity

NASA Astrophysics Data System (ADS)

Bishop, S. P.; Thompson, A. F.; Schodlok, M.

2016-02-01

The West Antarctic ice sheet is melting at unprecedented rates, which will impact global sea level rise. The ocean may be playing the dominant role in this ice melt through the upwelling of warm and salty Circumpolar Deep Water (CDW) in regions such as Pine Island Glacier (PIG). There is evidence that the Antarctic Slope Front at the continental shelf constrains shoreward transport of CDW by mesoscale eddies. However, little is known about the ocean-ice interaction and potential feedbacks that take place once this water is advected into ice shelf cavities. In this talk we use MITgcm to simulate an idealized setup of the PIG ice shelf cavity, similar to the setup in De Rydt et al. 2014, to understand the effects of ocean circulation and potential feedbacks of ice-shelf melt on the ocean circulation. To do this we run the model in two different configurations with and without a wind-driven current at the northern edge of the ice shelf and annually updating the geometry of the ice shelf based on the parameterized ice-shelf melt. Eddy heat and potential vorticity fluxes are diagnosed and presented for each of the simulations and compared with control simulations where the ice-shelf cavity is not modified. Results show high ice shelf melt during the first year with maximum values in excess of 60 meters near the grounding line, but settle to tens of meters during the following years.

The Effect of Diethylene Glycol Monomethyl Ether (DiEGME) on Microbial Contamination of Jet Fuel: A Minimum Concentration Study

DTIC Science & Technology

2010-03-01

added as appropriate. Fuel was filtered with a 0.45µm hydrophobic cellulose nitrate filter (Nalge Nunc, Rochester, NY) prior to use in the test setup...it may not be clear from the images above, biofilms were also present in all 0% test setups. In fuel systems, a biofilm is a microbial growth...formation that typically appears as a sheen, pellicule, or mat that forms between the fuel and water layers or on the interior sides of a tank. Biofilms

Design, development, and demonstration of a fully LabVIEW controlled in situ electrochemical Fourier transform infrared setup combined with a wall-jet electrode to investigate the electrochemical interface of nanoparticulate electrocatalysts under reaction conditions.

PubMed

Nesselberger, Markus; Ashton, Sean J; Wiberg, Gustav K H; Arenz, Matthias

2013-07-01

We present a detailed description of the construction of an in situ electrochemical ATR-FTIR setup combined with a wall-jet electrode to investigate the electrocatalytic properties of nanoparticulate catalysts in situ under controlled mass transport conditions. The presented setup allows the electrochemical interface to be probed in combination with the simultaneous determination of reaction rates. At the same time, the high level of automation allows it to be used as a standard tool in electrocatalysis research. The performance of the setup was demonstrated by probing the oxygen reduction reaction on a platinum black catalyst in sulfuric electrolyte.

Direct screening and confirmation of priority volatile organic pollutants in drinking water.

PubMed

Caro, J; Serrano, A; Gallego, M

2007-01-05

A screening tool was proposed for the rapid detection of eight priority volatile organic pollutants according to European standards in drinking water. The method is based on the direct coupling of a headspace sampler with a mass spectrometer, using a chromatographic column heated to 175 degrees C as an interface. The water sample was subjected to the headspace extraction process and the volatile fraction was introduced directly into the mass spectrometer, without prior chromatographic separation, achieving low detection limits (0.6-1.2 ng/ml) for all compounds. The mass spectrum resulting from the simultaneous ionization and fragmentation of the mixture of molecules constitutes the volatile profile of each sample. An appropriate chemometric treatment of these signals permitted them to be classified, on the basis of their volatile composition, as contaminated or uncontaminated with respect to the legally established concentration levels for these compounds in drinking water, and providing no false negatives. A conventional confirmation method was carried out to analyze positive water samples by using the same instrumental setup as in the screening method, but using an appropriate temperature program in the chromatographic column to separate, identify and quantify each analyte.

Experimental Evaluation of the Thermal Performance of a Water Shield for a Surface Power Reactor

NASA Technical Reports Server (NTRS)

Pearson, J. Boise; Stewart, Eric T.; Reid, Robert S.

2007-01-01

A water based shielding system is being investigated for use on initial lunar surface power systems. The use of water may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a representative lunar surface reactor shield design is evaluated at various power levels in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to anchor a CFD model. Performance of a water shield on the lunar surface is then predicted by CFD models anchored to test data. The accompanying viewgraph presentation includes the following topics: 1) Testbed Configuration; 2) Core Heater Placement and Instrumentation; 3) Thermocouple Placement; 4) Core Thermocouple Placement; 5) Outer Tank Thermocouple Placement; 6) Integrated Testbed; 7) Methodology; 8) Experimental Results: Core Temperatures; 9) Experimental Results; Outer Tank Temperatures; 10) CFD Modeling; 11) CFD Model: Anchored to Experimental Results (1-g); 12) CFD MOdel: Prediction for 1/6-g; and 13) CFD Model: Comparison of 1-g to 1/6-g.

Photoacoustic measurement of ammonia in the atmosphere: influence of water vapor and carbon dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rooth, R.A.; Verhage, A.J.L.; Wouters, L.W.

1990-09-01

The photoacoustic determination of the ammonia concentration in atmospheric air by absorption of CO{sub 2} laser radiation at 9.22 {mu}m is influenced by the presence of H{sub 2}O and CO{sub 2}. Kinetic cooling due to the coupling of excited CO{sub 2} and N{sub 2} levels causes important changes in phase and amplitude of the photoacoustic signal. Theoretical background is presented to deduce the correct NH{sub 3} concentration from the signal. The experimental setup used to perform field measurements is described. Adhesion of NH{sub 3} to the walls of the resonant photoacoustic cell was investigated. Temperature effects are treated. Field datamore » of NH{sub 3} and H{sub 2}O concentrations are presented. Key words: Photoacoustics, ammonia, kinetic cooling, trace gas measurements, ammonia adhesion, acoustic resonance, CO{sub 2} laser radiation, water vapor absorption, carbon dioxide absorption.« less

Hydro-geophysical observations integration in numerical model: case study in Mediterranean karstic unsaturated zone (Larzac, france)

NASA Astrophysics Data System (ADS)

Champollion, Cédric; Fores, Benjamin; Le Moigne, Nicolas; Chéry, Jean

2016-04-01

Karstic hydro-systems are highly non-linear and heterogeneous but one of the main water resource in the Mediterranean area. Neither local measurements in boreholes or analysis at the spring can take into account the variability of the water storage. Since a few years, ground-based geophysical measurements (such as gravity, electrical resistivity or seismological data) allows following water storage in heterogeneous hydrosystems at an intermediate scale between boreholes and basin. Behind classical rigorous monitoring, the integration of geophysical data in hydrological numerical models in needed for both processes interpretation and quantification. Since a few years, a karstic geophysical observatory (GEK: Géodésie de l'Environnement Karstique, OSU OREME, SNO H+) has been setup in the Mediterranean area in the south of France. The observatory is surrounding more than 250m karstified dolomite, with an unsaturated zone of ~150m thickness. At the observatory water level in boreholes, evapotranspiration and rainfall are classical hydro-meteorological observations completed by continuous gravity, resistivity and seismological measurements. The main objective of the study is the modelling of the whole observation dataset by explicit unsaturated numerical model in one dimension. Hydrus software is used for the explicit modelling of the water storage and transfer and links the different observations (geophysics, water level, evapotranspiration) with the water saturation. Unknown hydrological parameters (permeability, porosity) are retrieved from stochastic inversions. The scale of investigation of the different observations are discussed thank to the modelling results. A sensibility study of the measurements against the model is done and key hydro-geological processes of the site are presented.

Factors controlling stream water nitrate and phosphor loads during precipitation events

NASA Astrophysics Data System (ADS)

Rozemeijer, J. C.; van der Velde, Y.; van Geer, F. G.; de Rooij, G. H.; Broers, H. P.; Bierkens, M. F. P.

2009-04-01

Pollution of surface waters in densely populated areas with intensive land use is a serious threat to their ecological, industrial and recreational utilization. European and national manure policies and several regional and local pilot projects aim at reducing pollution loads to surface waters. For the evaluation of measures, water authorities and environmental research institutes are putting a lot of effort into monitoring surface water quality. Fro regional surface water quality monitoring, the measurement locations are usually situated in the downstream part of the catchment to represent a larger area. The monitoring frequency is usually low (e.g. monthly), due to the high costs for sampling and analysis. As a consequence, human induced trends in nutrient loads and concentrations in these monitoring data are often concealed by the large variability of surface water quality caused by meteorological variations. Because natural surface water quality variability is poorly understood, large uncertainties occur in the estimates of (trends in) nutrient loads or average concentrations. This study aims at uncertainty reduction in the estimates of mean concentrations and loads of N and P from regional monitoring data. For this purpose, we related continuous N and P records of stream water to variations in precipitation, discharge, groundwater level and tube drain discharge. A specially designed multi scale experimental setup was installed in an agricultural lowland catchment in The Netherlands. At the catchment outlet, continuous measurements of water quality and discharge were performed from July 2007-January 2009. At an experimental field within the catchment continuous measurements of precipitation, groundwater levels and tube drain discharges were collected. 20 significant rainfall events with a variety of antecedent conditions, durations and intensities were selected for analysis. Singular and multiple regression analysis was used to identify relations between the continuous N and P records and characteristics of the dynamics of discharge, precipitation, groundwater level and tube drain discharge. From this study, we conclude that generally available and easy to measure explanatory data (such as continuous records of discharge, precipitation and groundwater level) can reduce uncertainty in estimations of N and P loads and mean concentrations. However, for capturing the observed short load pulses of P, continuous or discharge proportional sampling is needed.

A novel explicit approach to model bromide and pesticide transport in connected soil structures

NASA Astrophysics Data System (ADS)

Klaus, J.; Zehe, E.

2011-07-01

The present study tests whether an explicit treatment of worm burrows and tile drains as connected structures is feasible for simulating water flow, bromide and pesticide transport in structured heterogeneous soils at hillslope scale. The essence is to represent worm burrows as morphologically connected paths of low flow resistance in a hillslope model. A recent Monte Carlo study (Klaus and Zehe, 2010, Hydrological Processes, 24, p. 1595-1609) revealed that this approach allowed successful reproduction of tile drain event discharge recorded during an irrigation experiment at a tile drained field site. However, several "hillslope architectures" that were all consistent with the available extensive data base allowed a good reproduction of tile drain flow response. Our second objective was thus to find out whether this "equifinality" in spatial model setups may be reduced when including bromide tracer data in the model falsification process. We thus simulated transport of bromide for the 13 spatial model setups that performed best with respect to reproduce tile drain event discharge, without any further calibration. All model setups allowed a very good prediction of the temporal dynamics of cumulated bromide leaching into the tile drain, while only four of them matched the accumulated water balance and accumulated bromide loss into the tile drain. The number of behavioural model architectures could thus be reduced to four. One of those setups was used for simulating transport of Isoproturon, using different parameter combinations to characterise adsorption according to the Footprint data base. Simulations could, however, only reproduce the observed leaching behaviour, when we allowed for retardation coefficients that were very close to one.

A novel explicit approach to model bromide and pesticide transport in soils containing macropores

NASA Astrophysics Data System (ADS)

Klaus, J.; Zehe, E.

2011-01-01

The present study tests whether an explicit treatment of worm burrows is feasible for simulating water flow, bromide and pesticide transport in structured heterogeneous soils. The essence is to represent worm burrows as morphologically connected paths of low flow resistance in the spatially highly resolved model domain. A recent Monte Carlo study (Klaus and Zehe, 2010) revealed that this approach allowed successful reproduction of tile drain event discharge recorded during an irrigation experiment at a tile drained field site. However, several "hillslope architectures" that were all consistent with the available extensive data base allowed a good reproduction of tile drain flow response. Our second objective was thus to find out whether this "equifinality" in spatial model setups may be reduced when including bromide tracer data in the model falsification process. We thus simulated transport of bromide and Isoproturon (IPU) for the 13 spatial model setups, which performed best with respect to reproduce tile drain event discharge, without any further calibration. All model setups allowed a very good prediction of the temporal dynamics of cumulated bromide leaching into the tile drain, while only four of them matched the accumulated water balance and accumulated bromide loss into the tile drain. The number of behavioural model architectures could thus be reduced to four. One of those setups was used for simulating transport of IPU, using different parameter combinations to characterise adsorption according to the Footprint data base. Simulations could, however, only reproduce the observed leaching behaviour, when we allowed for retardation coefficients that were very close to one.

Reliable measurement of E. coli single cell fluorescence distribution using a standard microscope set-up.

PubMed

Cortesi, Marilisa; Bandiera, Lucia; Pasini, Alice; Bevilacqua, Alessandro; Gherardi, Alessandro; Furini, Simone; Giordano, Emanuele

2017-01-01

Quantifying gene expression at single cell level is fundamental for the complete characterization of synthetic gene circuits, due to the significant impact of noise and inter-cellular variability on the system's functionality. Commercial set-ups that allow the acquisition of fluorescent signal at single cell level (flow cytometers or quantitative microscopes) are expensive apparatuses that are hardly affordable by small laboratories. A protocol that makes a standard optical microscope able to acquire quantitative, single cell, fluorescent data from a bacterial population transformed with synthetic gene circuitry is presented. Single cell fluorescence values, acquired with a microscope set-up and processed with custom-made software, are compared with results that were obtained with a flow cytometer in a bacterial population transformed with the same gene circuitry. The high correlation between data from the two experimental set-ups, with a correlation coefficient computed over the tested dynamic range > 0.99, proves that a standard optical microscope- when coupled with appropriate software for image processing- might be used for quantitative single-cell fluorescence measurements. The calibration of the set-up, together with its validation, is described. The experimental protocol described in this paper makes quantitative measurement of single cell fluorescence accessible to laboratories equipped with standard optical microscope set-ups. Our method allows for an affordable measurement/quantification of intercellular variability, whose better understanding of this phenomenon will improve our comprehension of cellular behaviors and the design of synthetic gene circuits. All the required software is freely available to the synthetic biology community (MUSIQ Microscope flUorescence SIngle cell Quantification).

Comparison of two types of neonatal extracorporeal life support systems with pulsatile and nonpulsatile flow.

PubMed

Haines, Nikkole; Wang, Shigang; Myers, John L; Undar, Akif

2009-11-01

We compared the effects of two neonatal extracorporeal life support (ECLS) systems on circuit pressures and surplus hemodynamic energy levels in a simulated ECLS model. The clinical set-up included the Jostra HL-20 heart-lung machine, either the Medtronic ECMO (0800) or the MEDOS 800LT systems with company-provided circuit components, a 10 Fr arterial cannula, and a pseudo-patient. We tested the system in nonpulsatile and pulsatile flow modes at two flow rates using a 40/60 glycerin/water blood analog, for a total of 48 trials, with n = 6 for each set-up. The pressure drops over the Medtronic ECLS were significantly higher than those over the MEDOS system regardless of the flow rate or perfusion mode (144.8 +/- 0.2 mm Hg vs. 35.7 +/- 0.2 mm Hg, respectively, at 500 mL/min in nonpulsatile mode, P < 0.001). The preoxygenator mean arterial pressures were significantly increased and the precannula hemodynamic energy values were decreased with the Medtronic ECLS circuit. These results suggest that the MEDOS ECLS circuit better transmits hemodynamic energy to the patient, keeps mean circuit pressures lower, and has lower pressure drops than the Medtronic Circuit.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Chu-Lin; Perfect, Edmund; Kang, Misun

Water retention curves are essential for understanding the hydrologic behavior of partially-saturated porous media and modeling flow transport processes within the vadose zone. In this paper we report direct measurements of the main drying and wetting branches of the average water retention function obtained using 2-dimensional neutron radiography. Flint sand columns were saturated with water and then drained under quasi-equilibrium conditions using a hanging water column setup. Digital images (2048 x 2048 pixels) of the transmitted flux of neutrons were acquired at each imposed matric potential (~10-15 matric potential values per experiment) at the NCNR BT-2 neutron imaging beam line.more » Volumetric water contents were calculated on a pixel by pixel basis using Beer-Lambert s law after taking into account beam hardening and geometric corrections. To remove scattering effects at high water contents the volumetric water contents were normalized (to give relative saturations) by dividing the drying and wetting sequences of images by the images obtained at saturation and satiation, respectively. The resulting pixel values were then averaged and combined with information on the imposed basal matric potentials to give average water retention curves. The average relative saturations obtained by neutron radiography showed an approximate one-to-one relationship with the average values measured volumetrically using the hanging water column setup. There were no significant differences (at p < 0.05) between the parameters of the van Genuchten equation fitted to the average neutron radiography data and those estimated from replicated hanging water column data. Our results indicate that neutron imaging is a very effective tool for quantifying the average water retention curve.« less

Monitoring water cycle elements using GNSS geodetic receivers at the field research station Marquardt, Germany

NASA Astrophysics Data System (ADS)

Simeonov, Tzvetan; Vey, Sibylle; Alshawaf, Fadwa; Dick, Galina; Guerova, Guergana; Güntner, Andreas; Hohmann, Christian; Kunwar, Ajeet; Trost, Benjamin; Wickert, Jens

2017-04-01

Water storage variations in the atmosphere and in soils are among the most dynamic within the Earth's water cycle. The continuous measurement of water storage in these media with a high spatial and temporal resolution is a challenging task, not yet completely solved by various observation techniques. With the development of the Global Navigation Satellite Systems (GNSS) a new approach for atmospheric water vapor estimation in the atmosphere and in parallel of soil moisture in the vicinity of GNSS ground stations was established in the recent years with several key advantages compared to traditional techniques. Regional and global GNSS networks are nowadays operationally used to provide the Integrated Water Vapor (IWV) information with high temporal resolution above the individual stations. Corresponding data products are used to improve the day-by-day weather prediction of leading forecast centers. Selected stations from these networks can be used to additionally derive the soil moisture in the vicinity of the receivers. Such parallel measurement of IWV and soil moisture using a single measuring device provides a unique possibility to analyze water fluxes between the atmosphere and the land surface. We installed an advanced experimental GNSS setup for hydrology at the field research station of the Leibniz Institute for Agricultural Engineering and Bioeconomy in Marquardt, around 30km West of Berlin, Germany. The setup includes several GNSS receivers, various Time Domain Reflectometry (TDR) sensors at different depths for soil moisture measurement and an meteorological station. The setup was mainly installed to develop and improve GNSS based techniques for soil moisture determination and to analyze GNSS IWV and SM in parallel on a long-term perspective. We introduce initial results from more than two years of measurements. The comparison in station Marquardt shows good agreement (correlation 0.79) between the GNSS derived soil moisture and the TDR measurements. A detailed study for several periods with different GNSS settings, vegetation and soil conditions in the vicinity of the station is presented with emphasis on the behavior of GNSS derived soil moisture, compared to TDR. Case studies of intense rainfall events and lasting dry periods show the interaction between the IWV and soil moisture.

Virtual gait training for children with cerebral palsy using the Lokomat gait orthosis.

PubMed

Koenig, Alexander; Wellner, Mathias; Köneke, Susan; Meyer-Heim, Andreas; Lünenburger, Lars; Riener, Robert

2008-01-01

The Lokomat gait orthosis was developed in the Spinal Cord Injury Center at the University Hospital Balgrist Zurich and provides automatic gait training for patients with neurological gait impairments, such as Cerebral Palsy (CP). Each patient undergoes a task-oriented Lokomat rehabilitation training program via a virtual reality setup. In four virtual scenarios, the patient is able to exercise tasks such as wading through water, playing soccer, overstepping obstacles or training in a street scenario, each task offering varying levels of difficulty. Patients provided positive feedback in reference to the utilized haptic method, specifically addressing the sufficient degree of realism. In a single case study, we verified the task difficulty.

Thermodynamics of information exchange between two coupled quantum dots

NASA Astrophysics Data System (ADS)

Kutvonen, Aki; Sagawa, Takahiro; Ala-Nissila, Tapio

2016-03-01

We propose a setup based on two coupled quantum dots where thermodynamics of a measurement can be quantitatively characterized. The information obtained in the measurement can be utilized by performing feedback in a manner apparently breaking the second law of thermodynamics. In this way the setup can be operated as a Maxwell's demon, where both the measurement and feedback are performed separately by controlling an external parameter. This is analogous to the case of the original Szilard engine. Since the setup contains both the microscopic demon and the engine itself, the operation of the whole measurement-feedback cycle can be explained in detail at the level of single realizations. In addition, we derive integral fluctuation relations for both the bare and coarse-grained entropy productions in the setup.

Application of the Methods of Gas Dynamics to Water Flows with Free Surface II : Flows with Momentum Discontinuities (hydraulic Jumps)

NASA Technical Reports Server (NTRS)

Preiswerk, Ernst

1940-01-01

In this paper an introduction to shock polar diagrams is given which then leads into an examination of water depths in hydraulic jumps. Energy loss during these jumps is considered along with an extended look at elementary solutions of flow. An experimental test set-up is described and the results presented.

Visualization of the contact line during the water exit of flat plates

NASA Astrophysics Data System (ADS)

Tassin, A.; Breton, T.; Forest, B.; Ohana, J.; Chalony, S.; Le Roux, D.; Tancray, A.

2017-08-01

We investigate experimentally the time evolution of the wetted surface during the lifting of a body initially floating at the water surface. This phenomenon is referred to as the water exit problem. The water exit experiments were conducted with transparent (PMMA) mock-ups of two different shapes: a circular disc and a square flat plate. Two different lighting systems were used to diffuse light in the mock-up material: a central high-power LED light normal to the surface and an edge-lighting system featuring an array of LED lights. These setups make it possible to illuminate the contact line, which delimits the surface of contact between the mock-up and the water. The characteristic size of the mock-ups is about 20 cm and the acceleration of the mock-up oscillates between 0 and 25 m/s^2. We show that the central light setup gives satisfactory results for the circular disc and that the edge lighting technique makes it possible to follow a contact line with a time-evolving complex shape (strong changes of convexity) up to 1000 fps. The observations presented in the paper support the possibility of extending this promising technique to more general three-dimensional bodies with arbitrary motion (e.g., including pitch motion).

Monitoring leaf water content with THz and sub-THz waves.

PubMed

Gente, Ralf; Koch, Martin

2015-01-01

Terahertz technology is still an evolving research field that attracts scientists with very different backgrounds working on a wide range of subjects. In the past two decades, it has been demonstrated that terahertz technology can provide a non-invasive tool for measuring and monitoring the water content of leaves and plants. In this paper we intend to review the different possibilities to perform in-vivo water status measurements on plants with the help of THz and sub-THz waves. The common basis of the different methods is the strong absorption of THz and sub-THz waves by liquid water. In contrast to simpler, yet destructive, methods THz and sub-THz waves allow for the continuous monitoring of plant water status over several days on the same sample. The technologies, which we take into focus, are THz time domain spectroscopy, THz continuous wave setups, THz quasi time domain spectroscopy and sub-THz continuous wave setups. These methods differ with respect to the generation and detection schemes, the covered frequency range, the processing and evaluation of the experimental data, and the mechanical handling of the measurements. Consequently, we explain which method fits best in which situation. Finally, we discuss recent and future technological developments towards more compact and budget-priced measurement systems for use in the field.

Characterization of Advanced Avalanche Photodiodes for Water Vapor Lidar Receivers

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Halama, Gary E.; DeYoung, Russell J.

2000-01-01

Development of advanced differential absorption lidar (DIAL) receivers is very important to increase the accuracy of atmospheric water vapor measurements. A major component of such receivers is the optical detector. In the near-infrared wavelength range avalanche photodiodes (APD's) are the best choice for higher signal-to-noise ratio, where there are many water vapor absorption lines. In this study, characterization experiments were performed to evaluate a group of silicon-based APD's. The APD's have different structures representative of different manufacturers. The experiments include setups to calibrate these devices, as well as characterization of the effects of voltage bias and temperature on the responsivity, surface scans, noise measurements, and frequency response measurements. For each experiment, the setup, procedure, data analysis, and results are given and discussed. This research was done to choose a suitable APD detector for the development of an advanced atmospheric water vapor differential absorption lidar detection system operating either at 720, 820, or 940 nm. The results point out the benefits of using the super low ionization ratio (SLIK) structure APD for its lower noise-equivalent power, which was found to be on the order of 2 to 4 fW/Hz(sup (1/2)), with an appropriate optical system and electronics. The water vapor detection systems signal-to-noise ratio will increase by a factor of 10.

Determination of phenylurea herbicides in water samples using online sorptive preconcentration and high-performance liquid chromatography with UV or electrospray mass spectrometric detection.

PubMed

Baltussen, E; Snijders, H; Janssen, H G; Sandra, P; Cramers, C A

1998-04-10

A recently developed method for the extraction of organic micropollutants from aqueous samples based on sorptive enrichment in columns packed with 100% polydimethylsiloxane (PDMS) particles was coupled on-line with HPLC analysis. The sorptive enrichment procedure originally developed for relatively nonpolar analytes was used to preconcentrate polar phenylurea herbicides from aqueous samples. PDMS extraction columns of 5, 10 and 25 cm were used to extract the herbicides from distilled, tap and river water samples. A model that allows prediction of retention and breakthrough volumes is presented. Despite the essentially apolar nature of the PDMS material, it is possible to concentrate sample volumes up to 10 ml on PDMS cartridges without losses of the most polar analyte under investigation, fenuron. For less polar analytes significantly larger sample volumes can be applied. Since standard UV detection does not provide adequate selectivity for river water samples, an electrospray (ES)-MS instrument was used to determine phenylurea herbicides in a water sample from the river Dommel. Methoxuron was present at a level of 80 ng/l. The detection limit of the current set-up, using 10 ml water samples and ES-MS detection is 10 ng/l in river water samples. Strategies for further improvement of the detection limits are identified.

Underwater Electromagnetic Sensor Networks—Part I: Link Characterization †

PubMed Central

Quintana-Díaz, Gara; Mena-Rodríguez, Pablo; Pérez-Álvarez, Iván; Jiménez, Eugenio; Dorta-Naranjo, Blas-Pablo; Zazo, Santiago; Pérez, Marina; Quevedo, Eduardo; Cardona, Laura; Hernández, J. Joaquín

2017-01-01

Underwater Wireless Sensor Networks (UWSNs) using electromagnetic (EM) technology in marine shallow waters are examined, not just for environmental monitoring but for further interesting applications. Particularly, the use of EM waves is reconsidered in shallow waters due to the benefits offered in this context, where acoustic and optical technologies have serious disadvantages. Sea water scenario is a harsh environment for radiocommunications, and there is no standard model for the underwater EM channel. The high conductivity of sea water, the effect of seabed and the surface make the behaviour of the channel hard to predict. This justifies the need of link characterization as the first step to approach the development of EM underwater sensor networks. To obtain a reliable link model, measurements and simulations are required. The measuring setup for this purpose is explained and described, as well as the procedures used. Several antennas have been designed and tested in low frequency bands. Agreement between attenuation measurements and simulations at different distances was analysed and made possible the validation of simulation setups and the design of different communications layers of the system. This leads to the second step of this work, where data and routing protocols for the sensor network are examined. PMID:28106843

Underwater Electromagnetic Sensor Networks-Part I: Link Characterization.

PubMed

Quintana-Díaz, Gara; Mena-Rodríguez, Pablo; Pérez-Álvarez, Iván; Jiménez, Eugenio; Dorta-Naranjo, Blas-Pablo; Zazo, Santiago; Pérez, Marina; Quevedo, Eduardo; Cardona, Laura; Hernández, J Joaquín

2017-01-19

Underwater Wireless Sensor Networks (UWSNs) using electromagnetic (EM) technology in marine shallow waters are examined, not just for environmental monitoring but for further interesting applications. Particularly, the use of EM waves is reconsidered in shallow waters due to the benefits offered in this context, where acoustic and optical technologies have serious disadvantages. Sea water scenario is a harsh environment for radiocommunications, and there is no standard model for the underwater EM channel. The high conductivity of sea water, the effect of seabed and the surface make the behaviour of the channel hard to predict. This justifies the need of link characterization as the first step to approach the development of EM underwater sensor networks. To obtain a reliable link model, measurements and simulations are required. The measuring setup for this purpose is explained and described, as well as the procedures used. Several antennas have been designed and tested in low frequency bands. Agreement between attenuation measurements and simulations at different distances was analysed and made possible the validation of simulation setups and the design of different communications layers of the system. This leads to the second step of this work, where data and routing protocols for the sensor network are examined.

Evaluation of dosimetric properties of shielding disk used in intraoperative electron radiotherapy: A Monte Carlo study.

PubMed

Robatjazi, Mostafa; Baghani, Hamid Reza; Mahdavic, Seied Rabi; Felici, Giuseppe

2018-05-01

A shielding disk is used for IOERT procedures to absorb radiation behind the target and protect underlying healthy tissues. Setup variation of shielding disk can affect the corresponding in-vivo dose distribution. In this study, the changes of dosimetric parameters due to the disk setup variations is evaluated using EGSnrc Monte Carlo (MC) code. The results can help treatment team to decide about the level of accuracy in the setup procedure and delivered dose to the target volume during IOERT. Copyright © 2018 Elsevier Ltd. All rights reserved.

Biodegradation of paper waste using Eisenia foetida by vermicomposting Technology

NASA Astrophysics Data System (ADS)

Mathivanan, Mahalakshmi; Aravind Vishnu Saravanan, G.; Baji, Aravindh; Manoj kumar, J.

2017-07-01

The paper wastes are being a big concern over past decades. The process of reuse of the paper wastes is employed by ‘eisenia foetida’ in Vermiculture. The paper waste in SASTRA is collected around 50kg and organic wastes like vegetable wastes and cow dung wastes are also collected. In the adjacent area of Nirman Vihar, SASTRA, the experimental setup is done in a Geosynthetic polymer bag. The area is divided into three segments and in each segment appropriate amount of paper waste and organic waste were added along with 25 numbers of earthworms. The setup is watered daily and monitored periodically and it is kindled for proper aeration. The soil samples were collected on 20 days, 45 days and 60 days from the day the earthworms were added. After 60 days of the experiment, the paper wastes, compost and earthworms are separated. The quantity of the wastes was compared to the initial amount and the composts are collected. The elemental analysis of the soil used as Vermi-bed is analyzed for improvement of soil nutrients. The vermiwashed water of the setup is analyzed for total protein. The number of earthworm is also compared to initial quantity. Out of all, the loss percentage of the organic waste and paper waste shows the degradation of the paper wastes.

Automation of a high-speed imaging setup for differential viscosity measurements

NASA Astrophysics Data System (ADS)

Hurth, C.; Duane, B.; Whitfield, D.; Smith, S.; Nordquist, A.; Zenhausern, F.

2013-12-01

We present the automation of a setup previously used to assess the viscosity of pleural effusion samples and discriminate between transudates and exudates, an important first step in clinical diagnostics. The presented automation includes the design, testing, and characterization of a vacuum-actuated loading station that handles the 2 mm glass spheres used as sensors, as well as the engineering of electronic Printed Circuit Board (PCB) incorporating a microcontroller and their synchronization with a commercial high-speed camera operating at 10 000 fps. The hereby work therefore focuses on the instrumentation-related automation efforts as the general method and clinical application have been reported earlier [Hurth et al., J. Appl. Phys. 110, 034701 (2011)]. In addition, we validate the performance of the automated setup with the calibration for viscosity measurements using water/glycerol standard solutions and the determination of the viscosity of an "unknown" solution of hydroxyethyl cellulose.

Clinical multiphoton and CARS microscopy

NASA Astrophysics Data System (ADS)

Breunig, H. G.; Weinigel, M.; Darvin, M. E.; Lademann, J.; König, K.

2012-03-01

We report on clinical CARS imaging of human skin in vivo with the certified hybrid multiphoton tomograph CARSDermaInspect. The CARS-DermaInspect provides simultaneous imaging of non-fluorescent intradermal lipid and water as well as imaging of two-photon excited fluorescence from intrinsic molecules. Two different excitation schemes for CARS imaging have been realized: In the first setup, a combination of fs oscillator and optical parametric oscillator provided fs-CARS pump and Stokes pulses, respectively. In the second setup a fs oscillator was combined with a photonic crystal fiber which provided a broadband spectrum. A spectral range out of the broadband-spectrum was selected and used for CARS excitation in combination with the residual fs-oscillator output. In both setups, in addition to CARS, single-beam excitation was used for imaging of two-photon excited fluorescence and second harmonic generation signals. Both CARS-excitation systems were successfully used for imaging of lipids inside the skin in vivo.

Automation of a high-speed imaging setup for differential viscosity measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurth, C.; Duane, B.; Whitfield, D.

We present the automation of a setup previously used to assess the viscosity of pleural effusion samples and discriminate between transudates and exudates, an important first step in clinical diagnostics. The presented automation includes the design, testing, and characterization of a vacuum-actuated loading station that handles the 2 mm glass spheres used as sensors, as well as the engineering of electronic Printed Circuit Board (PCB) incorporating a microcontroller and their synchronization with a commercial high-speed camera operating at 10 000 fps. The hereby work therefore focuses on the instrumentation-related automation efforts as the general method and clinical application have beenmore » reported earlier [Hurth et al., J. Appl. Phys. 110, 034701 (2011)]. In addition, we validate the performance of the automated setup with the calibration for viscosity measurements using water/glycerol standard solutions and the determination of the viscosity of an “unknown” solution of hydroxyethyl cellulose.« less

Space Shuttle Main Engine Low Pressure Oxidizer Turbo-Pump Inducer Dynamic Environment Characterization through Water Model and Hot-Fire Testing

NASA Technical Reports Server (NTRS)

Arellano, Patrick; Patton, Marc; Schwartz, Alan; Stanton, David

2006-01-01

The Low Pressure Oxidizer Turbopump (LPOTP) inducer on the Block II configuration Space Shuttle Main Engine (SSME) experienced blade leading edge ripples during hot firing. This undesirable condition led to a minor redesign of the inducer blades. This resulted in the need to evaluate the performance and the dynamic environment of the redesign, relative to the current configuration, as part of the design acceptance process. Sub-scale water model tests of the two inducer configurations were performed, with emphasis on the dynamic environment due to cavitation induced vibrations. Water model tests were performed over a wide range of inlet flow coefficient and pressure conditions, representative of the scaled operating envelope of the Block II SSME, both in flight and in ground hot-fire tests, including all power levels. The water test hardware, facility set-up, type and placement of instrumentation, the scope of the test program, specific test objectives, data evaluation process and water test results that characterize and compare the two SSME LPOTP inducers are discussed. In addition, dynamic characteristics of the two water models were compared to hot fire data from specially instrumented ground tests. In general, good agreement between the water model and hot fire data was found, which confirms the value of water model testing for dynamic characterization of rocket engine turbomachinery.

Ensemble-based evaluation of extreme water levels for the eastern Baltic Sea

NASA Astrophysics Data System (ADS)

Eelsalu, Maris; Soomere, Tarmo

2016-04-01

The risks and damages associated with coastal flooding that are naturally associated with an increase in the magnitude of extreme storm surges are one of the largest concerns of countries with extensive low-lying nearshore areas. The relevant risks are even more contrast for semi-enclosed water bodies such as the Baltic Sea where subtidal (weekly-scale) variations in the water volume of the sea substantially contribute to the water level and lead to large spreading of projections of future extreme water levels. We explore the options for using large ensembles of projections to more reliably evaluate return periods of extreme water levels. Single projections of the ensemble are constructed by means of fitting several sets of block maxima with various extreme value distributions. The ensemble is based on two simulated data sets produced in the Swedish Meteorological and Hydrological Institute. A hindcast by the Rossby Centre Ocean model is sampled with a resolution of 6 h and a similar hindcast by the circulation model NEMO with a resolution of 1 h. As the annual maxima of water levels in the Baltic Sea are not always uncorrelated, we employ maxima for calendar years and for stormy seasons. As the shape parameter of the Generalised Extreme Value distribution changes its sign and substantially varies in magnitude along the eastern coast of the Baltic Sea, the use of a single distribution for the entire coast is inappropriate. The ensemble involves projections based on the Generalised Extreme Value, Gumbel and Weibull distributions. The parameters of these distributions are evaluated using three different ways: maximum likelihood method and method of moments based on both biased and unbiased estimates. The total number of projections in the ensemble is 40. As some of the resulting estimates contain limited additional information, the members of pairs of projections that are highly correlated are assigned weights 0.6. A comparison of the ensemble-based projection of extreme water levels and their return periods with similar estimates derived from local observations reveals an interesting pattern of match and mismatch. The match is almost perfect in measurement sites where local effects (e.g., wave-induced set-up or local surge in very shallow areas that are not resolved by circulation models) do not contribute to the observed values of water level. There is, however, substantial mismatch between projected and observed extreme values for most of the Estonian coast. The mismatch is largest for sections that are open to high waves and for several bays that are deeply cut into mainland but open for predominant strong wind directions. Detailed quantification of this mismatch eventually makes it possible to develop substantially improved estimates of extreme water levels in sections where local effects considerably contribute into the total water level.

SWAT Model Configuration, Calibration and Validation for Lake Champlain Basin

EPA Pesticide Factsheets

The Soil and Water Assessment Tool (SWAT) model was used to develop phosphorus loading estimates for sources in the Lake Champlain Basin. This document describes the model setup and parameterization, and presents calibration results.

Couch height–based patient setup for abdominal radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohira, Shingo; Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita; Ueda, Yoshihiro

2016-04-01

There are 2 methods commonly used for patient positioning in the anterior-posterior (A-P) direction: one is the skin mark patient setup method (SMPS) and the other is the couch height–based patient setup method (CHPS). This study compared the setup accuracy of these 2 methods for abdominal radiation therapy. The enrollment for this study comprised 23 patients with pancreatic cancer. For treatments (539 sessions), patients were set up by using isocenter skin marks and thereafter treatment couch was shifted so that the distance between the isocenter and the upper side of the treatment couch was equal to that indicated on themore » computed tomographic (CT) image. Setup deviation in the A-P direction for CHPS was measured by matching the spine of the digitally reconstructed radiograph (DRR) of a lateral beam at simulation with that of the corresponding time-integrated electronic portal image. For SMPS with no correction (SMPS/NC), setup deviation was calculated based on the couch-level difference between SMPS and CHPS. SMPS/NC was corrected using 2 off-line correction protocols: no action level (SMPS/NAL) and extended NAL (SMPS/eNAL) protocols. Margins to compensate for deviations were calculated using the Stroom formula. A-P deviation > 5 mm was observed in 17% of SMPS/NC, 4% of SMPS/NAL, and 4% of SMPS/eNAL sessions but only in one CHPS session. For SMPS/NC, 7 patients (30%) showed deviations at an increasing rate of > 0.1 mm/fraction, but for CHPS, no such trend was observed. The standard deviations (SDs) of systematic error (Σ) were 2.6, 1.4, 0.6, and 0.8 mm and the root mean squares of random error (σ) were 2.1, 2.6, 2.7, and 0.9 mm for SMPS/NC, SMPS/NAL, SMPS/eNAL, and CHPS, respectively. Margins to compensate for the deviations were wide for SMPS/NC (6.7 mm), smaller for SMPS/NAL (4.6 mm) and SMPS/eNAL (3.1 mm), and smallest for CHPS (2.2 mm). Achieving better setup with smaller margins, CHPS appears to be a reproducible method for abdominal patient setup.« less

An Attosecond Transient Absorption Spectroscopy Setup with a Water Window Attosecond source

NASA Astrophysics Data System (ADS)

Chew, Andrew; Yin, Yanchun; Li, Jie; Ren, Xiaoming; Wang, Yang; Wu, Yi; Chang, Zenghu

2017-04-01

Attosecond transient absorption, or time-resolved pump-probe spectroscopy, are excellent tools that can be used to investigate fast electron dynamics for a given atomic or molecular system. Recent push for high energy long wavelength few cycle laser sources has resulted in the production of x-ray spectra that would allow the probing of electron dynamics at the carbon k-edge in molecules such as CH4 and CO2. The motion of charges can be caused by photo-dissociation and charge migration. We present here the first results from our experimental setup where we produce a broadband attosecond pulse with spectra that stretches into the water window. National Science Foundation (1068604), Army Research Oce (W911NF-14-1-0383), Air Force Oce of Scientic Research (FA9550-15-1-0037, FA9550-16-1-0013) and the DARPA PULSE program by a Grant from AMRDEC (W31P4Q1310017).

Crosstalk in an FDM Laboratory Setup and the Athena X-IFU End-to-End Simulator

NASA Astrophysics Data System (ADS)

den Hartog, R.; Kirsch, C.; de Vries, C.; Akamatsu, H.; Dauser, T.; Peille, P.; Cucchetti, E.; Jackson, B.; Bandler, S.; Smith, S.; Wilms, J.

2018-04-01

The impact of various crosstalk mechanisms on the performance of the Athena X-IFU instrument has been assessed with detailed end-to-end simulations. For the crosstalk in the electrical circuit, a detailed model has been developed. In this contribution, we test this model against measurements made with an FDM laboratory setup and discuss the assumption of deterministic crosstalk in the context of the weak link effect in the detectors. We conclude that crosstalk levels predicted by the model are conservative with respect to the observed levels.

Pupil light reflex evoked by light-emitting diode and computer screen: Methodology and association with need for recovery in daily life.

PubMed

Wang, Yang; Zekveld, Adriana A; Wendt, Dorothea; Lunner, Thomas; Naylor, Graham; Kramer, Sophia E

2018-01-01

Pupil light reflex (PLR) has been widely used as a method for evaluating parasympathetic activity. The first aim of the present study is to develop a PLR measurement using a computer screen set-up and compare its results with the PLR generated by a more conventional setup using light-emitting diode (LED). The parasympathetic nervous system, which is known to control the 'rest and digest' response of the human body, is considered to be associated with daily life fatigue. However, only few studies have attempted to test the relationship between self-reported daily fatigue and physiological measurement of the parasympathetic nervous system. Therefore, the second aim of this study was to investigate the relationship between daily-life fatigue, assessed using the Need for Recovery scale, and parasympathetic activity, as indicated by the PLR parameters. A pilot study was conducted first to develop a PLR measurement set-up using a computer screen. PLRs evoked by light stimuli with different characteristics were recorded to confirm the influence of light intensity, flash duration, and color on the PLRs evoked by the system. In the subsequent experimental study, we recorded the PLR of 25 adult participants to light flashes generated by the screen set-up as well as by a conventional LED set-up. PLR parameters relating to parasympathetic and sympathetic activity were calculated from the pupil responses. We tested the split-half reliability across two consecutive blocks of trials, and the relationships between the parameters of PLRs evoked by the two set-ups. Participants rated their need for recovery prior to the PLR recordings. PLR parameters acquired in the screen and LED set-ups showed good reliability for amplitude related parameters. The PLRs evoked by both set-ups were consistent, but showed systematic differences in absolute values of all parameters. Additionally, higher need for recovery was associated with faster and larger constriction of the PLR. This study assessed the PLR generated by a computer screen and the PLR generated by a LED. The good reliability within set-ups and the consistency between the PLRs evoked by the set-ups indicate that both systems provides a valid way to evoke the PLR. A higher need for recovery was associated with faster and larger constricting PLRs, suggesting increased levels of parasympathetic nervous system activity in people experiencing higher levels of need for recovery on a daily basis.

Simple shielding reduces dose to the contralateral breast during prone breast cancer radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goyal, Uma, E-mail: uma.goyal@gmail.com; Locke, Angela; Smith-Raymond, Lexie

Our goal was to design a prone breast shield for the contralateral breast and study its efficacy in decreasing scatter radiation to the contralateral breast in a prone breast phantom setup receiving radiation therapy designed for breast cancer. We constructed a prone breast phantom setup consisting of (1) A thermoplastic mask with a left-sided depression created by a water balloon for a breast shape; (2) 2 plastic bags to hold water in the thermoplastic mask depression; (3) 2000 mL of water to fill the thermoplastic mask depression to create a water-based false breast; (4) 1-cm thick bolus placed in themore » contralateral breast holder; (5) 2 lead (Pb) sheets, each 0.1-cm thick for blocking scatter radiation in the contralateral bolus-based false breast; (6) a prone breast board to hold the thermoplastic mask, water, bolus, and lead; (7) 9 cm solid water on top of the breast board to simulate body; (8) a diode was used to verify dose for each treatment field of the treated water-based breast; (9) metal–oxide–semiconductor-field effect transistor (MOSFET) dosimeters to measure dose to the contralateral bolus-based breast. The phantom prone breast setup was CT simulated and treatment was designed with 95% isodose line covering the treated breast. The maximum dose was 107.1%. Megavoltage (MV) port images ensured accurate setup. Measurements were done using diodes on the treated water-based breast and MOSFET dosimeters at the medial and lateral sides of the contralateral bolus-based breast without and with the Pb shield. Five treatments were done for each of the 3 data sets and recorded individually for statistical purposes. All treatments were completed with 6 MV photons at 200 cGy per treatment. The dose contributions from each of the 3 data sets including 15 treatments total without and with the prone lead shield to the medial and lateral portions of contralateral bolus-based breast were averaged individually. Unshielded dose means were 37.11 and 2.94 cGy, and shielded dose means were 12.68 and 1.54 cGy, respectively. When comparing medial and lateral portions of the contralateral bolus-based doses without and with Pb, the shield significantly reduced dose to both sides of the contralateral breast (medial p = 2.64 × 10{sup −14}, lateral p = 4.91 × 10{sup −6}). The prone 0.2-cm Pb shield significantly reduced scatter dose to the contralateral breast on the order of 2 to 3 times. Reductions may be clinically relevant for women younger than 45 years by decreasing the risk of contralateral radiation-induced breast cancer in patients receiving radiation therapy for breast cancer. This shield is simple as it would be a part of the prone breast board during treatments, but future studies are warranted for safety and efficacy clinically.« less

Addressing reverse osmosis fouling within water reclamation--a side-by-side comparison of low-pressure membrane pretreatments.

PubMed

Kent, Fraser C; Farahbakhsh, Khosrow

2011-06-01

A tertiary membrane filtration (TMF) pilot operating on secondary effluent and a membrane bioreactor (MBR) were setup in a side-by-side study as pretreatments for two identical reverse osmosis pilot systems. The water quality of the permeate from both low-pressure membrane pretreatment systems and the fouling rate of the reverse osmosis systems were compared to assess the capabilities of the two low-pressure membrane pretreatments to prevent organic fouling of the reverse osmosis systems. Both pretreatment pilots were setup using typical operating conditions (i.e., solids retention time and mixed-liquor suspended solids). A consistent difference in water quality and reverse osmosis performance was demonstrated during the 12-month study. The MBR permeate consistently had significantly lower total organic carbon (TOC) and chemical oxygen demand concentrations, but higher color and specific UV absorbance compared with the permeate from the TMF pretreatment. The pretreatment with the MBR gave an average reverse osmosis fouling rate over the entire study (0.27 Lmh/bar.month) that was less than half of the value found for the reverse osmosis with TMF pretreatment (0.60 Lmh/bar.month). A correlation of reverse osmosis feed TOC concentration with average reverse osmosis fouling rate also was established, independent of the pretreatment method used. Results from a cleaning analysis, energy dispersive spectroscopy, and fourier transformed infrared reflectometry confirmed that the foulants were primarily organic in nature. It is concluded that, for this type of application and setup, MBR systems present an advantage over tertiary membrane polishing of secondary effluent for reverse osmosis pretreatment.

A multifunctional setup to record FTIR and UV-vis spectra of organic molecules and their photoproducts in astronomical ices.

PubMed

Kofman, V; Witlox, M J A; Bouwman, J; Ten Kate, I L; Linnartz, H

2018-05-01

This article describes a new, multi-functional, high-vacuum ice setup that allows to record the in situ and real-time spectra of vacuum UV (VUV)-irradiated non-volatile molecules embedded in a low-temperature (10 K) amorphous solid water environment. Three complementary diagnostic tools-UV-visible (UV-vis) and Fourier Transform Infrared (FTIR) spectroscopy and temperature-programmed desorption quadrupole mass spectrometry-can be used to simultaneously study the physical and chemical behavior of the organic molecules in the ice upon VUV irradiation. The setup is equipped with a temperature-controlled sublimation oven that enables the controlled homogeneous deposition of solid species such as amino acids, nucleobases, and polycyclic aromatic hydrocarbons (PAHs) in ice mixtures prepared from precursor gases and/or liquids. The resulting ice is photo-processed with a microwave discharge hydrogen lamp, generating VUV radiation with a spectral energy distribution representative for the interstellar medium. The characteristics, performance, and future potential of the system are discussed by describing three different applications. First, a new method is introduced, which uses broadband interference transmission fringes recorded during ice deposition, to determine the wavelength-dependent refractive index, n λ , of amorphous solid water. This approach is also applicable to other solids, pure and mixed. Second, the UV-vis and FTIR spectroscopy of an VUV-irradiated triphenylene:water ice mixture is discussed, monitoring the ionization efficiency of PAHs in interstellar ice environments. The third and final example investigates the stability of solid glycine upon VUV irradiation by monitoring the formation of dissociation products in real time.

IMAGE Project: Results of Laboratory Tests on Tracers for Supercritical Conditions.

NASA Astrophysics Data System (ADS)

Brandvoll, Øyvind; Opsahl Viig, Sissel; Nardini, Isabella; Muller, Jiri

2016-04-01

The use of tracers is a well-established technique for monitoring dynamic behaviour of water and gas through a reservoir. In geothermal reservoirs special challenges are encountered due to high temperatures and pressures. In this work, tracer candidates for monitoring water at supercritical conditions (temperature > 374°C, pressure ca 218 bar), are tested in laboratory experiments. Testing of tracers at supercritical water conditions requires experimental set-ups which tolerate harsh conditions with respect to high temperature and pressure. In addition stringent HES (health, environment and safety) factors have to be taken into consideration when designing and performing the experiments. The setup constructed in this project consists of a pressure vessel, high pressure pump, instrumentation for pressure and temperature control and instrumentation required for accurate sampling of tracers. In order to achieve accurate results, a special focus has been paid to the development of the tracer sampling technique. Perfluorinated cyclic hydrocarbons (PFCs) have been selected as tracer candidates. This group of compounds is today commonly used as gas tracers in oil reservoirs. According to the literature they are stable at temperatures up to 400°C. To start with, five PFCs have been tested for thermal stability in static experiments at 375°C and 108 bar in the experimental setup described above. The tracer candidates will be further tested for several months at the relevant conditions. Preliminary results indicate that some of the PFC compounds show stability after three months. However, in order to arrive at conclusive results, the experiments have to be repeated over a longer period and paying special attention to more accurate sampling procedures.

A multifunctional setup to record FTIR and UV-vis spectra of organic molecules and their photoproducts in astronomical ices

NASA Astrophysics Data System (ADS)

Kofman, V.; Witlox, M. J. A.; Bouwman, J.; ten Kate, I. L.; Linnartz, H.

2018-05-01

This article describes a new, multi-functional, high-vacuum ice setup that allows to record the in situ and real-time spectra of vacuum UV (VUV)-irradiated non-volatile molecules embedded in a low-temperature (10 K) amorphous solid water environment. Three complementary diagnostic tools—UV-visible (UV-vis) and Fourier Transform Infrared (FTIR) spectroscopy and temperature-programmed desorption quadrupole mass spectrometry—can be used to simultaneously study the physical and chemical behavior of the organic molecules in the ice upon VUV irradiation. The setup is equipped with a temperature-controlled sublimation oven that enables the controlled homogeneous deposition of solid species such as amino acids, nucleobases, and polycyclic aromatic hydrocarbons (PAHs) in ice mixtures prepared from precursor gases and/or liquids. The resulting ice is photo-processed with a microwave discharge hydrogen lamp, generating VUV radiation with a spectral energy distribution representative for the interstellar medium. The characteristics, performance, and future potential of the system are discussed by describing three different applications. First, a new method is introduced, which uses broadband interference transmission fringes recorded during ice deposition, to determine the wavelength-dependent refractive index, nλ, of amorphous solid water. This approach is also applicable to other solids, pure and mixed. Second, the UV-vis and FTIR spectroscopy of an VUV-irradiated triphenylene:water ice mixture is discussed, monitoring the ionization efficiency of PAHs in interstellar ice environments. The third and final example investigates the stability of solid glycine upon VUV irradiation by monitoring the formation of dissociation products in real time.

In-situ hydrogen in metal determination using a minimum neutron source strength and exposure time.

PubMed

Hatem, M; Agamy, S; Khalil, M Y

2013-08-01

Water is frequently present in the environment and is a source of hydrogen that can interact with many materials. Because of its small atomic size, a hydrogen atom can easily diffuse into a host metal, and though the metal may appear unchanged for a time, the metal will eventually abruptly lose its strength and ductility. Thus, measuring the hydrogen content in metals is important in many fields, such as in the nuclear industry, in automotive and aircraft fabrication, and particularly, in offshore oil and gas fields. It has been demonstrated that the use of nuclear methods to measure the hydrogen content in metals can achieve sensitivity levels on the order of parts per million. However, the use of nuclear methods in the field has not been conducted for two reasons. The first reason is due to exposure limitations. The second reason is due to the hi-tech instruments required for better accuracy. In this work, a new method using a low-strength portable neutron source is explored in conjunction with detectors based on plastic nuclear detection films. The following are the in-situ requirements: simplicity in setup, high reliability, minimal exposure dose, and acceptable accuracy at an acceptable cost. A computer model of the experimental setup is used to reproduce the results of a proof-of-concept experiment and to predict the sensitivity levels under optimised experimental conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Landscape-scale water balance monitoring with an iGrav superconducting gravimeter in a field enclosure

NASA Astrophysics Data System (ADS)

Güntner, Andreas; Reich, Marvin; Mikolaj, Michal; Creutzfeldt, Benjamin; Schroeder, Stephan; Wziontek, Hartmut

2017-04-01

In spite of the fundamental role of the landscape water balance for the Earth's water and energy cycles, monitoring the water balance and its components beyond the point scale is notoriously difficult due to the multitude of flow and storage processes and their spatial heterogeneity. Here, we present the first deployment of an iGrav superconducting gravimeter (SG) in a minimized field enclosure on a grassland site for integrative monitoring of water storage changes. Results of the field SG were compared to data provided by a nearby SG located in the controlled environment of an observatory building. For wet-temperate climate conditions, the system proves to provide gravity time series that are similarly precise as those of the observatory SG. At the same time, the field SG is more sensitive to hydrological variations than the observatory SG. We demonstrate that the gravity variations observed by the field setup are almost independent of the depth below the terrain surface where water storage changes occur (contrary to SGs in buildings), and thus the field SG system directly observes the total water storage change, i.e., the water balance, in its surroundings in an integrative way. We provide a framework to single out the water balance components actual evapotranspiration and lateral subsurface discharge from the gravity time series on annual to daily time scales. With about 99% and 85% of the gravity signal originating within a radius of 4000 and 200 meter around the instrument, respectively, this setup paves the road towards gravimetry as a continuous hydrological field monitoring technique at the landscape scale.

Characterization of a new MOSFET detector configuration for in vivo skin dosimetry.

PubMed

Scalchi, Paolo; Francescon, Paolo; Rajaguru, Priyadarshini

2005-06-01

The dose released to the patient skin during a radiotherapy treatment is important when the skin is an organ at risk, or on the contrary, is included in the target volume. Since most treatment planning programs do not predict dose within several millimeters of the body surface, it is important to have a method to verify the skin dose for the patient who is undergoing radiotherapy. A special type of metal oxide semiconductors field-effect transistors (MOSFET) was developed to perform in vivo skin dosimetry for radiotherapy treatments. Water-equivalent depth (WED), both manufacturing and sensor reproducibility, dependence on both field size and angulation of the sensor were investigated using 6 MV photon beams. Patient skin dosimetries were performed during 6 MV total body irradiations (TBI). The resulting WEDs ranged from 0.04 and 0.15 mm (0.09 mm on average). The reproducibility of the sensor response, for doses of 50 cGy, was within +/-2% (maximum deviation) and improves with increasing sensitivity or dose level. As to the manufacturing reproducibility, it was found to be +/-0.055 mm. No WED dependence on the field size was verified, but possible variations of this quantity with the field size could be hidden by the assessment uncertainty. The angular dependence, for both phantom-surface and in-air setups, when referred to the mean response, is within +/-27% until 80 degree rotations. The results of the performed patient skin dosimetries showed that, normally, our TBI setup was suitable to give skin the prescribed dose, but, for some cases, interventions were necessary: as a consequence the TBI setup was corrected. The water-equivalent depth is, on average, less than the thinnest thermoluminescent dosimeters (TLD). In addition, when compared with TLDs, the skin MOSFETs have significant advantages, like immediate both readout and reuse, as well as the permanent storage of dose. These sensors are also waterproof. The in vivo dosimetries performed prove the importance of verifying the dose to the skin of the patient undergoing radiotherapy.

Protein/ionic liquid/glassy carbon sensors following analyte focusing by ionic liquid micelle collapse for simultaneous determination of water soluble vitamins in plasma matrices.

PubMed

Abd El-Hady, D; Albishri, H M

2015-07-01

Two novel sensors based on human serum albumin (HSA)-ionic liquid (IL) and bovine serum albumin (BSA)-ionic liquid (IL) composites modified glassy carbon electrode (GCE) were produced for simultaneous determination of water soluble vitamins B2, B6 and C in human plasma following analytes focusing by IL micelles collapse (AFILMC). For selective and efficient extraction, vitamins were dissolved in 3.0molL(-1) micellar solution of 1-octyl-3-methyl imidazolium bromide IL. The extracted vitamins were hydrodynamically injected by 25mbar for 20s into a running buffer of 12.5mmolL(-1) phosphate at pH 6.0 followed by electrochemical detection (ECD) on protein/1-octyl-3-methyl imidazolium hexafluorophosphate IL/GC sensors. The chemical stability of proposed sensors was achieved up to 7 days without any decomposition of PF6-based IL/protein and adsorption of interfering ions. In the current work, the sensitivity enhancement factor (SEF) up to 5000-fold was achieved using the AFILMC/ECD setup compared to conventional CE/UV. Under optimal conditions, linear calibration graphs were obtained from 0.5, 0.5 and 1.0 to 1500.0µgmL(-1) of vitamins B2, B6 and C, respectively. Detection limits of analytes were ranged from 180.0 to 520.0ngmL(-1). The proposed AFILMC/ECD setup was successfully applied to the assay of trace level quantification of vitamins in human plasma samples and also their binding constants with HSA and BSA were determined. The concurrent use of IL micelles for the proposed separation and detection processes exhibited some advantages, such as, a reduction of use toxic solvents, an efficient extraction and a direct injection of samples with a short-single run. Furthermore, IL micelles, having variable possibility of interactions, facilitated the successful achievements of AFILMC/ECD setup for the quantification of vitamins in plasma matrices. Copyright © 2015 Elsevier B.V. All rights reserved.

PSA discriminator influence on (222)Rn efficiency detection in waters by liquid scintillation counting.

PubMed

Stojković, Ivana; Todorović, Nataša; Nikolov, Jovana; Tenjović, Branislava

2016-06-01

A procedure for the (222)Rn determination in aqueous samples using liquid scintillation counting (LSC) was evaluated and optimized. Measurements were performed by ultra-low background spectrometer Quantulus 1220™ equipped with PSA (Pulse Shape Analysis) circuit which discriminates alpha/beta spectra. Since calibration procedure is carried out with (226)Ra standard, which has both alpha and beta progenies, it is clear that PSA discriminator has vital importance in order to provide precise spectra separation. Improvement of calibration procedure was done through investigation of PSA discriminator level and, consequentially, the activity of (226)Ra calibration standard influence on (222)Rn efficiency detection. Quench effects on generated spectra i.e. determination of radon efficiency detection were also investigated with quench calibration curve obtained. Radon determination in waters based on modified procedure according to the activity of (226)Ra standard used, dependent on PSA setup, was evaluated with prepared (226)Ra solution samples and drinking water samples with assessment of measurement uncertainty variation included. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physical modelling of LNG rollover in a depressurized container filled with water

NASA Astrophysics Data System (ADS)

Maksim, Dadonau; Denissenko, Petr; Hubert, Antoine; Dembele, Siaka; Wen, Jennifer

2015-11-01

Stable density stratification of multi-component Liquefied Natural Gas causes it to form distinct layers, with upper layer having a higher fraction of the lighter components. Heat flux through the walls and base of the container results in buoyancy-driven convection accompanied by heat and mass transfer between the layers. The equilibration of densities of the top and bottom layers, normally caused by the preferential evaporation of Nitrogen, may induce an imbalance in the system and trigger a rapid mixing process, so-called rollover. Numerical simulation of the rollover is complicated and codes require validation. Physical modelling of the phenomenon has been performed in a water-filled depressurized vessel. Reducing gas pressure in the container to levels comparable to the hydrostatic pressure in the water column allows modelling of tens of meters industrial reservoirs using a 20 cm laboratory setup. Additionally, it allows to model superheating of the base fluid layer at temperatures close the room temperature. Flow visualizations and parametric studies are presented. Results are related to outcomes of numerical modelling.

Characteristics and Limitations of Submerged GPS L1 Observations

NASA Astrophysics Data System (ADS)

Steiner, Ladina; Geiger, Alain

2017-04-01

Extensive amount of water stored in snow covers has a high impact on flood development during snow melting periods. Early assessment of these parameters in mountain environments enhance early-warning and thus prevention of major impacts. Sub-snow GNSS techniques are lately suggested to determine liquid water content, snow water equivalent or considered for avalanche rescue. This technique is affordable, flexible, and provides accurate and continuous observations independent on weather conditions. However, the characteristics of GNSS observations for applications within a snow-pack still need to be further investigated. The magnitude of the main interaction processes involved for the GPS wavelength propagating through different layers of snow, ice or water is theoretically examined. Liquid water exerts the largest influence on GPS signal propagation through a snow-pack. Therefore, we focus on determining the characteristics of GNSS observables under water. An experiment was set-up to investigate the characteristics and limitations of submerged GPS observations using a pool, a level control by communicating pipes, a geodetic and a low-cost GPS antenna, and a water level sensor. The GPS antennas were placed into the water. The water level was increased daily by a step of two millimeters up to thirty millimeters above the antenna. Based on this experiment, the signal penetration depth, satellite availability, the attenuation of signal strength and the quality of solutions are analyzed. Our experimental results show an agreement with the theoretically derived attenuation parameter and signal penetration depth. The assumption of water as the limiting parameter for GPS observations within a snow-pack can be confirmed. Higher wetness in a snow-pack leads to less transmission, higher refraction, higher attenuation and thus a decreased penetration depth as well as a reduced quality of the solutions. In consequence, GPS applications within a snow-pack are heavily impacted by wetness which is even more pronounced during melting period. In this poster, we present a short introduction to the principle, explain the developed algorithms and show results of experiments dedicated to the signal propagation in water.

Field induced anomalous spreading, oscillation, ejection, spinning, and breaking of oil droplets on a strongly slipping water surface.

PubMed

Kumar, Sunny; Sarma, Bhaskarjyoti; Dasmahapatra, Ahsok Kumar; Dalal, Amaresh; Basu, Dipankar Narayan; Bandyopadhyay, Dipankar

2017-07-01

Application of an electric field on an oil droplet floating on the surface of a deionized water bath showed interesting motions such as spreading, oscillation, and ejection. The electric field was generated by connecting a pointed platinum cathode at the top of the oil droplet and a copper anode coated with polymer at the bottom of the water layer. The experimental setup mimicked a conventional electrowetting setup with the exception that the oil was spread on a soft and deformable water isolator. While at relatively lower field intensities we observed spreading of the droplet, at intermediate field intensities the droplet oscillated around the platinum cathode, before ejecting out at a speed as high as ∼5 body lengths per second at even stronger field intensities. The experiments suggested that when the electric field was ramped up abruptly to a particular voltage, any of the spreading, oscillation, or ejection motions of the droplet could be engendered at lower, intermediate and higher field intensities, respectively. However, when the field was ramped up progressively by increasing by a definite amount of voltage per unit time, all three aforementioned motions could be generated simultaneously with the increase in the field intensity. Interestingly, when the aforementioned setup was placed on a magnet, the droplet showed a rotational motion under the influence of the Lorentz force, which was generated because of the coupling of the weak leakage current with the externally applied magnetic field. The spreading, oscillation, ejection, and rotation of the droplet were found to be functions of the oil-water interfacial tension, viscosity, and size of the oil droplet. We developed simple theoretical models to explain the experimental results obtained. Importantly, rotating at a higher speed broke the droplet into a number of smaller ones, owing to the combined influence of the spreading due to the centripetal force and the shear at the oil-water interface. While the oscillatory and rotational motions of the incompressible droplet could be employed as stirrers or impellers inside microfluidic devices for mixing applications, the droplet ejection could be employed for futuristic applications such as payload transport or drug delivery.

Observations of infragravity motions for reef fringed islands and atolls

NASA Astrophysics Data System (ADS)

Becker, J. M.; Merrifield, M. A.; Ford, M.

2012-12-01

The frequency of flooding events that affect low lying islands and atolls in the Pacific is expected to increase under current sea level rise projections. Infragravity (IG) motions, with periods ranging from approximately 25 to 400 seconds, are an important component of wave driven flooding events for reef fringed islands and atolls. The IG variability during wave events is analyzed and interpreted dynamically from pressure and current observations at four cross-reef transects in the North Pacific Ocean that include sites in the Republic of the Marshall Islands and Guam. The IG motions are shown to depend upon the spectral properties of the incident wave forcing and reef flat characteristics that include reef flat length (ranging from 100m to 450m at the four sites) and total water level due to setup and tides. A small inundation event at one of the sites is shown to occur due to large shoreline infragravity energy.

Assimilation of CryoSat-2 altimetry to a hydrodynamic model of the Brahmaputra river

NASA Astrophysics Data System (ADS)

Schneider, Raphael; Nygaard Godiksen, Peter; Ridler, Marc-Etienne; Madsen, Henrik; Bauer-Gottwein, Peter

2016-04-01

Remote sensing provides valuable data for parameterization and updating of hydrological models, for example water level measurements of inland water bodies from satellite radar altimeters. Satellite altimetry data from repeat-orbit missions such as Envisat, ERS or Jason has been used in many studies, also synthetic wide-swath altimetry data as expected from the SWOT mission. This study is one of the first hydrologic applications of altimetry data from a drifting orbit satellite mission, namely CryoSat-2. CryoSat-2 is equipped with the SIRAL instrument, a new type of radar altimeter similar to SRAL on Sentinel-3. CryoSat-2 SARIn level 2 data is used to improve a 1D hydrodynamic model of the Brahmaputra river basin in South Asia set up in the DHI MIKE 11 software. CryoSat-2 water levels were extracted over river masks derived from Landsat imagery. After discharge calibration, simulated water levels were fitted to the CryoSat-2 data along the Assam valley by adapting cross section shapes and datums. The resulting hydrodynamic model shows accurate spatio-temporal representation of water levels, which is a prerequisite for real-time model updating by assimilation of CryoSat-2 altimetry or multi-mission data in general. For this task, a data assimilation framework has been developed and linked with the MIKE 11 model. It is a flexible framework that can assimilate water level data which are arbitrarily distributed in time and space. Different types of error models, data assimilation methods, etc. can easily be used and tested. Furthermore, it is not only possible to update the water level of the hydrodynamic model, but also the states of the rainfall-runoff models providing the forcing of the hydrodynamic model. The setup has been used to assimilate CryoSat-2 observations over the Assam valley for the years 2010 to 2013. Different data assimilation methods and localizations were tested, together with different model error representations. Furthermore, the impact of different filtering and clustering methods and error descriptions of the CryoSat-2 observations was evaluated. Performance improvement in terms of discharge and water level forecast due to the assimilation of satellite altimetry data was then evaluated. The model forecasts were also compared to climatology and persistence forecasts. Using ensemble based filters, the evaluation was done not only based on performance criteria for the central forecast such as root-mean-square error (RMSE) and Nash-Sutcliffe model efficiency (NSE), but also based on sharpness, reliability and continuous ranked probability score (CRPS) of the ensemble of probabilistic forecasts.

Physical response of a back-barrier estuary to a post-tropical cyclone

USGS Publications Warehouse

Beudin, Alexis; Ganju, Neil Kamal; Defne, Zafer; Aretxabaleta, Alfredo

2017-01-01

This paper presents a modeling investigation of the hydrodynamic and sediment transport response of Chincoteague Bay (VA/MD, USA) to Hurricane Sandy using the Coupled Ocean-Atmosphere-Wave-Sediment-Transport (COAWST) modeling system. Several simulation scenarios with different combinations of remote and local forces were conducted to identify the dominant physical processes. While 80% of the water level increase in the bay was due to coastal sea level at the peak of the storm, a rich spatial and temporal variability in water surface slope was induced by local winds and waves. Local wind increased vertical mixing, horizontal exchanges, and flushing through the inlets. Remote waves (swell) enhanced southward flow through wave setup gradients between the inlets, and increased locally generated wave heights. Locally generated waves had a negligible effect on water level but reduced the residual flow up to 70% due to enhanced apparent roughness and breaking-induced forces. Locally generated waves dominated bed shear stress and sediment resuspension in the bay. Sediment transport patterns mirrored the interior coastline shape and generated deposition on inundated areas. The bay served as a source of fine sediment to the inner shelf, and the ocean-facing barrier island accumulated sand from landward-directed overwash. Despite the intensity of the storm forcing, the bathymetric changes in the bay were on the order of centimeters. This work demonstrates the spectrum of responses to storm forcing, and highlights the importance of local and remote processes on back-barrier estuarine function.

A periodic review integrated inventory model with controllable setup cost, imperfect items, and inspection errors under service level constraint

NASA Astrophysics Data System (ADS)

Saga, R. S.; Jauhari, W. A.; Laksono, P. W.

2017-11-01

This paper presents an integrated inventory model which consists of single vendor and buyer. The buyer managed its inventory periodically and orders products from the vendor to satisfy the end customer’s demand, where the annual demand and the ordering cost were in the fuzzy environment. The buyer used a service level constraint instead of the stock-out cost term, so that the stock-out level per cycle was bounded. Then, the vendor produced and delivered products to the buyer. The vendor had a choice to commit an investment to reduce the setup cost. However, the vendor’s production process was imperfect, thus the lot delivered contained some defective products. Moreover, the buyer’s inspection process was not error-free since the inspector could be mistaken in categorizing the product’s quality. The objective was to find the optimum value for the review period, the setup cost, and the number of deliveries in one production cycle which might minimize the joint total cost. Furthermore, the algorithm and numerical example were provided to illustrate the application of the model.

Assessment of the dynamics of human glymphatic system by near-infrared spectroscopy.

PubMed

Myllylä, Teemu; Harju, Markus; Korhonen, Vesa; Bykov, Alexander; Kiviniemi, Vesa; Meglinski, Igor

2017-08-12

Fluctuations in brain water content has attracted increasing interest, particularly as regards studies of the glymphatic system, which is connected with the complex organization of dural lymphatic vessels, responsible for cleaning tissue. Disturbances of glymphatic circulation are associated with several brain disorders, including dementia. This article introduces an approach to noninvasive measurement of water dynamics in the human brain utilizing near-infrared spectroscopy (NIRS). We demonstrate the possibility to sense dynamic variations of water content between the skull and grey matter, for instance, in the subarachnoid space. Measured fluctuations in water content, especially in the cerebrospinal fluid (CSF), are assumed to be correlated with the dynamics of glymphatic circulation. The sampling volume for the NIRS optode was estimated by Monte Carlo modelling for the wavelengths of 660, 740, 830 and 980 nm. In addition, using combinations of these wavelengths, this article presents the calculation models for quantifying water and haemodynamics. The presented NIRS technique allows long-term functional brain monitoring, including sleeping time. Furthermore, it is used in combination with different magnetic neuroimaging techniques, particularly magnetic resonance encephalography. Using the combined setup, we report the preliminary results on the interaction between CSF and blood oxygen level-dependent fluctuations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Long-Term Monitoring of Regional Sea Surface Height Variability Using High-Resolution Satellite Altimetry

NASA Astrophysics Data System (ADS)

Rice, A. E.; Crout, R. L.

2017-12-01

Shallow water altimetry is an emerging field that in recent years has rapidly gained attention for both the numerous applications it can offer to the oceanographic community (e.g. assessment of climate change impacts to the coastal zone; quantification of sea state etc.) and, depending on the altimeter used, for the wealth of available historical data that can be employed for climatological studies. In this study we focus on the long-term analysis of regional sea surface height anomaly (SSHA) variability over the mid and outer shelf (≥ 16 km from the coast) for 18 selected coastal altimeter tracks located on the east coast of the US and Asia for a period of eight years (294 passes from July 2008 to July 2016) using Jason-2 20 Hz altimeter data from the L2 AVISO-PISTACH experimental products. After implementing geophysical corrections to the raw altimeter range, signal noise in the individual SSH passes was reduced by applying a median filter followed by a 60-point (18 km) low-pass filter as in Birol and Delebeque (2014). Since individual altimeter passes did not cease to collect data at the same distance from the coastline, a nearest-point-to-land (NPTL) was determined for each track for statistical analysis of the data. NPTL time series and SSHA envelopes, computed by subtracting mean SSHAs from individual passes, were used for the analysis. A comparison of wind and water level gauge data to a US east coast track reveals correlation between SSHA and winds and a relationship to subtidal water level frequencies. Time series of NPTL for all tracks show intra-annual and inter and intra-seasonal variability, with higher and lower water levels linked to seasons. Lastly, envelope plots display higher SSHA variability over the mid shelf than the outer shelf, revealing the location and magnitude (up to 0.5 m water level differences) of setup and set down occurrences. Various products derived from the analysis that are useful for oceanographic operations, including water level change percentages and width of coastal boundary layers, are discussed.

Collider shot setup for Run 2 observations and suggestions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Annala, J.; Joshel, B.

1996-01-31

This note is intended to provoke discussion on Collider Run II shot setup. We hope this is a start of activities that will converge on a functional description of what is needed for shot setups in Collider Run II. We will draw on observations of the present shot setup to raise questions and make suggestions for the next Collider run. It is assumed that the reader has some familiarity with the Collider operational issues. Shot setup is defined to be the time between the end of a store and the time the Main Control Room declares colliding beams. This ismore » the time between Tevatron clock events SCE and SCB. This definition does not consider the time experiments use to turn on their detectors. This analysis was suggested by David Finley. The operational scenarios for Run II will require higher levels of reliability and speed for shot setup. See Appendix I and II. For example, we estimate that a loss of 3 pb{sup {minus}1}/week (with 8 hour stores) will occur if shot setups take 90 minutes instead of 30 minutes. In other words: If you do 12 shots for one week and accept an added delay of one minute in each shot, you will loose more than 60 nb{sup {minus}1} for that week alone (based on a normal shot setup of 30 minutes). These demands should lead us to be much more pedantic about all the factors that affect shot setups. Shot setup will be viewed as a distinct process that is composed of several inter- dependent `components`: procedures, hardware, controls, and sociology. These components don`t directly align with the different Accelerator Division departments, but are topical groupings of the needed accelerator functions. Defining these components, and categorizing our suggestions within them, are part of the goal of this document. Of course, some suggestions span several of these components.« less

A nested observation and model approach to non linear groundwater surface water interactions.

NASA Astrophysics Data System (ADS)

van der Velde, Y.; Rozemeijer, J. C.; de Rooij, G. H.

2009-04-01

Surface water quality measurements in The Netherlands are scattered in time and space. Therefore, water quality status and its variations and trends are difficult to determine. In order to reach the water quality goals according to the European Water Framework Directive, we need to improve our understanding of the dynamics of surface water quality and the processes that affect it. In heavily drained lowland catchment groundwater influences the discharge towards the surface water network in many complex ways. Especially a strong seasonal contracting and expanding system of discharging ditches and streams affects discharge and solute transport. At a tube drained field site the tube drain flux and the combined flux of all other flow routes toward a stretch of 45 m of surface water have been measured for a year. Also the groundwater levels at various locations in the field and the discharge at two nested catchment scales have been monitored. The unique reaction of individual flow routes on rainfall events at the field site allowed us to separate the discharge at a 4 ha catchment and at a 6 km2 into flow route contributions. The results of this nested experimental setup combined with the results of a distributed hydrological model has lead to the formulation of a process model approach that focuses on the spatial variability of discharge generation driven by temporal and spatial variations in groundwater levels. The main idea of this approach is that discharge is not generated by catchment average storages or groundwater heads, but is mainly generated by points scale extremes i.e. extreme low permeability, extreme high groundwater heads or extreme low surface elevations, all leading to catchment discharge. We focused on describing the spatial extremes in point scale storages and this led to a simple and measurable expression that governs the non-linear groundwater surface water interaction. We will present the analysis of the field site data to demonstrate the potential of nested-scale, high frequency observations. The distributed hydrological model results will be used to show transient catchment scale relations between groundwater levels and discharges. These analyses lead to a simple expression that can describe catchment scale groundwater surface water interactions.

Picosecond imaging of sprays

NASA Technical Reports Server (NTRS)

Breisacher, Kevin; Liou, Larry; Wang, L.; Liang, X.; Galland, P.; Ho, P. P.; Alfano, R. R.

1994-01-01

Preliminary results from applying a Kerr-Fourier imaging system to a water/air spray produced by a shear coaxial element are presented. The physics behind ultrafast time-gated optical techniques is discussed briefly. A typical setup of a Kerr-Fourier time gating system is presented.

Landscape-scale water balance monitoring with an iGrav superconducting gravimeter in a field enclosure

NASA Astrophysics Data System (ADS)

Güntner, Andreas; Reich, Marvin; Mikolaj, Michal; Creutzfeldt, Benjamin; Schroeder, Stephan; Wziontek, Hartmut

2017-06-01

In spite of the fundamental role of the landscape water balance for the Earth's water and energy cycles, monitoring the water balance and its components beyond the point scale is notoriously difficult due to the multitude of flow and storage processes and their spatial heterogeneity. Here, we present the first field deployment of an iGrav superconducting gravimeter (SG) in a minimized enclosure for long-term integrative monitoring of water storage changes. Results of the field SG on a grassland site under wet-temperate climate conditions were compared to data provided by a nearby SG located in the controlled environment of an observatory building. The field system proves to provide gravity time series that are similarly precise as those of the observatory SG. At the same time, the field SG is more sensitive to hydrological variations than the observatory SG. We demonstrate that the gravity variations observed by the field setup are almost independent of the depth below the terrain surface where water storage changes occur (contrary to SGs in buildings), and thus the field SG system directly observes the total water storage change, i.e., the water balance, in its surroundings in an integrative way. We provide a framework to single out the water balance components actual evapotranspiration and lateral subsurface discharge from the gravity time series on annual to daily timescales. With about 99 and 85 % of the gravity signal due to local water storage changes originating within a radius of 4000 and 200 m around the instrument, respectively, this setup paves the road towards gravimetry as a continuous hydrological field-monitoring technique at the landscape scale.

An ultra-stable iodine-based frequency reference for space applications

NASA Astrophysics Data System (ADS)

Schuldt, Thilo; Braxmaier, Claus; Doeringshoff, Klaus; Keetman, Anja; Reggentin, Matthias; Kovalchuk, Evgeny; Peters, Achim

2012-07-01

Future space missions require for ultra-stable optical frequency references. Examples are the gravitational wave detector LISA/eLISA (Laser Interferometer Space Antenna), the SpaceTime Asymmetry Research (STAR) program, the aperture-synthesis telescope Darwin and the GRACE (Gravity Recovery and Climate Experiment) follow on mission exploring Earth's gravity. As high long-term frequency stability is required, lasers stabilized to atomic or molecular transitions are preferred, also offering an absolute frequency reference. Frequency stabilities in the 10 ^{-15} domains at longer integration times (up to several hours) are demonstrated in laboratory experiments using setups based on Doppler-free spectroscopy. Such setups with a frequency stability comparable to the hydrogen maser in the microwave domain, have the potential to be developed space compatible on a relatively short time scale. Here, we present the development of ultra-stable optical frequency references based on modulation-transfer spectroscopy of molecular iodine. Noise levels of 2\\cdot10 ^{-14} at an integration time of 1 s and below 3\\cdot10 ^{-15} at integration times between 100 s and 1000 s are demonstrated with a laboratory setup using an 80 cm long iodine cell in single-pass configuration in combination with a frequency-doubled Nd:YAG laser and standard optical components and optomechanic mounts. The frequency stability at longer integration times is (amongst other things) limited by the dimensional stability of the optical setup, i.e. by th pointing stability of the two counter-propagating beams overlapped in the iodine cell. With the goal of a future space compatible setup, a compact frequency standard on EBB (elegant breadboard) level was realized. The spectroscopy unit utilizes a baseplate made of Clearceram-HS, a glass ceramics with an ultra-low coefficient of thermal expansion of 2\\cdot10 ^{-8} K ^{-1}. The optical components are joint to the baseplate using adhesive bonding technology, which was developed in a cooperation of HTWG Konstanz and Astrium Friedrichshafen. This setup ensures a higher long-term frequency stability due to enhanced pointing stability. Also, it takes into account space mission related criteria such as compactness, robustness, MAIVT and environmental influences (shock, vibration and thermal tests). The assembly-integration technology was already successfully environmentally tested and demonstrated in a previous setup of a compact fiber-coupled heterodyne interferometer, which serves as a demonstrator for the optical readout of the LISA gravitational reference sensor. We present first measurements of the EBB setup and a first design of an iodine frequency standard on engineering model (EM) level. The EM-setup is based on the EBB experience, but features smaller dimensions by using a multipass iodine cell and less optical components. Financial support by the German Space Agency DLR with funds provided by the Federal Ministry of Economics and Technology (BMWi) under grant number 50 QT 1102 is highly appreciated.

Effects of potentised substances on growth rate of the water plant Lemna gibba L.

PubMed

Scherr, Claudia; Simon, Meinhard; Spranger, Jörg; Baumgartner, Stephan

2009-04-01

This study investigated, whether the growth rate of Lemna gibba L. (duckweed) can be influenced by the application of homeopathic potencies of gibberellic acid, kinetin, argentum nitricum, and lemna minor. Duckweed was grown in either potencies (14x-30x, decimal steps) or water controls (unsuccussed and succussed) over seven days. Frond (leaf-like structure) growth was measured using a non-destructive image analysis system. Growth rates were calculated for three time intervals (0-7, 0-3, 3-7 days). Five to six independent, randomized and blinded experiments were analysed for each of the four tested substances. Water control experiments were performed repeatedly to test the reliability of the experimental set-up (systematic negative controls). The systematic negative control experiments did not yield any significant effects. Hence, false positive results could be excluded. The test system had a low coefficient of variation (1.5%). Out of the four tested substances gibberellic acid had the most pronounced effect (p=0.0002, F-test) on the main outcome parameter frond growth rate (r(area) day 0-7). Potency levels 15x, 17x, 18x, 23x and 24x reduced growth rate of Lemna gibba (p<0.05 against the pooled water control, LSD test). Lemna gibba may be considered as a suitable test organism for further studies on the efficacy of homeopathic potencies. Evidence accumulates, that adjacent potency levels may strongly differ in their biological activity. Potential consequences for therapeutical application might be worth investigating.

Evaluating a sensor setup with respect to near-surface soil water monitoring and determination of in-situ water retention functions

NASA Astrophysics Data System (ADS)

Nolz, R.; Kammerer, G.

2017-06-01

Monitoring water status near the soil surface is a prerequisite for studying hydrological processes at the soil-atmosphere boundary and an option for calibrating remotely sensed water content data, for instance. As the water status of the uppermost soil layer is highly variable in space and time, adequate sensors are required to enable accurate measurements. Therefore, a sensor setup was tested and evaluated in the laboratory and in the field for such a purpose. The arrangement included Hydra Probe and MPS-2 sensors to measure water content and matric potential, respectively. Performance of the MPS-2 was validated in the laboratory by comparing sensor readings with the water potential of a soil, drained to equilibrium for certain pressure steps inside a pressure plate apparatus. Afterwards, six Hydra Probes and twelve MPS-2 sensors were installed in bare soil at a small field plot of about 9 m2. The measurements represented soil water status to a depth of 6 cm from surface. Core samples were repeatedly excavated around the measurement spots. Their water content was determined and the samples were further utilized to analyze water retention characteristics. The tested setup properly reflected changes of near-surface soil water status due to rainfall and evaporation. However, some shortcomings weakened the potential of the chosen arrangement. Site-specific calibration of the Hydra Probes - implemented by relating sensor readings to the water content values of the core samples - confirmed the applicability of the recommended standard calibration parameters for the respective soil texture. The derived user calibration enabled a measurement accuracy of 0.02 cm3·cm-3. Further improvement was restrained by the spatial variability of soil moisture. In this context, spots that were permanently drier or wetter than the others were discovered by means of a temporal stability approach. Performance of MPS-2 sensors was more critical with respect to the objectives. Sensor-to-sensor variation was small at the applied pressure steps of -20, -50, and -100 kPa, but the respective averaged readings were -18, -37, and -57 kPa. At matric potentials of -200 and -300 kPa, the MPS-2 revealed substantial sensor-to-sensor variation. The large deviation of the sensor readings in the field confirmed that the calibration of the MPS-2 should be improved. However, in spite of this inaccuracy, the wide measuring range of the MPS-2 offers suitability to a wide range of potential applications. As an example, water retention functions were calculated from the in-situ data and compared to retention data from the core samples.

A New Optical Scheme for a Polarimetric-Based Glucose Sensor

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Boeckle, Stefan; Rovati, Luigi; Salzman, Jack A. (Technical Monitor)

2002-01-01

We describe a new optical scheme to perform polarimetric measurements to detect glucose concentration in the aqueous humor of a model eye. The ultimate aim is to apply this technique in designing a new instrument for measuring glucose levels in diabetic patients routinely, frequently, and non-invasively. The scheme exploits the Brewsterreflection of circularly polarized light off of the lens of the eye. Theoretically, this backreflected linearly polarized light on its way to the detector is expected to rotate its state of polarization due to the presence of glucose molecules in the aqueous humor of patients. An experimental laboratory setup based on this scheme was designed and tested by measuring a range of known concentration of glucose solutions dissolved in water.

Uncertainty quantification in operational modal analysis with stochastic subspace identification: Validation and applications

NASA Astrophysics Data System (ADS)

Reynders, Edwin; Maes, Kristof; Lombaert, Geert; De Roeck, Guido

2016-01-01

Identified modal characteristics are often used as a basis for the calibration and validation of dynamic structural models, for structural control, for structural health monitoring, etc. It is therefore important to know their accuracy. In this article, a method for estimating the (co)variance of modal characteristics that are identified with the stochastic subspace identification method is validated for two civil engineering structures. The first structure is a damaged prestressed concrete bridge for which acceleration and dynamic strain data were measured in 36 different setups. The second structure is a mid-rise building for which acceleration data were measured in 10 different setups. There is a good quantitative agreement between the predicted levels of uncertainty and the observed variability of the eigenfrequencies and damping ratios between the different setups. The method can therefore be used with confidence for quantifying the uncertainty of the identified modal characteristics, also when some or all of them are estimated from a single batch of vibration data. Furthermore, the method is seen to yield valuable insight in the variability of the estimation accuracy from mode to mode and from setup to setup: the more informative a setup is regarding an estimated modal characteristic, the smaller is the estimated variance.

The virtual slice setup.

PubMed

Lytton, William W; Neymotin, Samuel A; Hines, Michael L

2008-06-30

In an effort to design a simulation environment that is more similar to that of neurophysiology, we introduce a virtual slice setup in the NEURON simulator. The virtual slice setup runs continuously and permits parameter changes, including changes to synaptic weights and time course and to intrinsic cell properties. The virtual slice setup permits shocks to be applied at chosen locations and activity to be sampled intra- or extracellularly from chosen locations. By default, a summed population display is shown during a run to indicate the level of activity and no states are saved. Simulations can run for hours of model time, therefore it is not practical to save all of the state variables. These, in any case, are primarily of interest at discrete times when experiments are being run: the simulation can be stopped momentarily at such times to save activity patterns. The virtual slice setup maintains an automated notebook showing shocks and parameter changes as well as user comments. We demonstrate how interaction with a continuously running simulation encourages experimental prototyping and can suggest additional dynamical features such as ligand wash-in and wash-out-alternatives to typical instantaneous parameter change. The virtual slice setup currently uses event-driven cells and runs at approximately 2 min/h on a laptop.

SU-F-T-383: Robustness for Patient Setup Error in Total Body Irradiation Using Volumetric Modulated Arc Therapy (VMAT)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takahashi, Y; National Cancer Center, Kashiwa, Chiba; Tachibana, H

Purpose: Total body irradiation (TBI) and total marrow irradiation (TMI) using Tomotherapy have been reported. A gantry-based linear accelerator uses one isocenter during one rotational irradiation. Thus, 3–5 isocenter points should be used for a whole plan of TBI-VMAT during smoothing out the junctional dose distribution. IGRT provides accurate and precise patient setup for the multiple junctions, however it is evident that some setup errors should occur and affect accuracy of dose distribution in the area. In this study, we evaluated the robustness for patient’s setup error in VMAT-TBI. Methods: VMAT-TBI Planning was performed in an adult whole-body human phantommore » using Eclipse. Eight full arcs with four isocenter points using 6MV-X were used to cover the entire whole body. Dose distribution was optimized using two structures of patient’s body as PTV and lung. The two arcs were shared with one isocenter and the two arcs were 5 cm-overlapped with the other two arcs. Point absolute dose using ionization-chamber and planer relative dose distribution using film in the junctional regions were performed using water-equivalent slab phantom. In the measurements, several setup errors of (+5∼−5mm) were added. Results: The result of the chamber measurement shows the deviations were within ±3% when the setup errors were within ±3 mm. In the planer evaluation, the pass ratio of gamma evaluation (3%/2mm) shows more than 90% if the errors within ±3 mm. However, there were hot/cold areas in the edge of the junction even with acceptable gamma pass ratio. 5 mm setup error caused larger hot and cold areas and the dosimetric acceptable areas were decreased in the overlapped areas. Conclusion: It can be clinically acceptable for VMAT-TBI when patient setup error is within ±3mm. Averaging effects from patient random error would be helpful to blur the hot/cold area in the junction.« less

SU-F-J-192: A Quick and Effective Method to Validate Patient’s Daily Setup and Geometry Changes Prior to Proton Treatment Delivery Based On Water Equivalent Thickness Projection Imaging (WETPI) for Head Neck Cancer (HNC) Patient

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, G; Qin, A; Zhang, J

Purpose: With the implementation of Cone-beam Computed-Tomography (CBCT) in proton treatment, we introduces a quick and effective tool to verify the patient’s daily setup and geometry changes based on the Water-Equivalent-Thickness Projection-Image(WETPI) from individual beam angle. Methods: A bilateral head neck cancer(HNC) patient previously treated via VMAT was used in this study. The patient received 35 daily CBCT during the whole treatment and there is no significant weight change. The CT numbers of daily CBCTs were corrected by mapping the CT numbers from simulation CT via Deformable Image Registration(DIR). IMPT plan was generated using 4-field IMPT robust optimization (3.5% rangemore » and 3mm setup uncertainties) with beam angle 60, 135, 300, 225 degree. WETPI within CTV through all beam directions were calculated. 3%/3mm gamma index(GI) were used to provide a quantitative comparison between initial sim-CT and mapped daily CBCT. To simulate an extreme case where human error is involved, a couch bar was manually inserted in front of beam angle 225 degree of one CBCT. WETPI was compared in this scenario. Results: The average of GI passing rate of this patient from different beam angles throughout the treatment course is 91.5 ± 8.6. In the cases with low passing rate, it was found that the difference between shoulder and neck angle as well as the head rest often causes major deviation. This indicates that the most challenge in treating HNC is the setup around neck area. In the extreme case where a couch bar is accidently inserted in the beam line, GI passing rate drops to 52 from 95. Conclusion: WETPI and quantitative gamma analysis give clinicians, therapists and physicists a quick feedback of the patient’s setup accuracy or geometry changes. The tool could effectively avoid some human errors. Furthermore, this tool could be used potentially as an initial signal to trigger plan adaptation.« less

Detection of the effect of nanoparticles on myelin figures growth using a compact digital holographic microscope

NASA Astrophysics Data System (ADS)

Ebrahimi, Samira; Soltani, Peyman; Moradi, Ali-Reza; Tayebi, Lobat

2013-11-01

Digital holographic microscopy (DHM) is an effective and non-destructive technique for quantitative phase contrast imaging of biological samples and living organelles. In this paper, using a simple and stable common-path DHM setup we study lipid bilayer dynamics and detect their morphological changes. Stacks of lipid amphiphilic molecules in excess water and at the presence of an external stimulus, stress, or force have great capability for the formation of multilamellar cylindrical tubes that are called myelin figures(MFs). MFs can be found in various healthy and diseased living cells and their formation and dynamics in various conditions involve mysterious configurations that have been of high interest. We utilized nanoparticles solved in water with different concentrations as an external stimulus for MFs of POPC lipid. The nanoparticles are injected into the sample container via a microinjection pump in a constant rate and MFs growth rate and their volume changes are measured by a compact digital holographic system. The setup is based on a binocular conventional microscope making the setup very stable against vibrations and noises. The recorded holograms are then computationally reconstructed. The measurements and investigations are performed by analyzing the reconstruction process. We showed that nanoparticles increase the growth rate of MFs during the first few seconds. However, after few seconds, the growth rate does not alter significantly comparing to the absence of nanoparticles.

Simulation of Columbia River Floods in the Hanford Reach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waichler, Scott R.; Serkowski, John A.; Perkins, William A.

Columbia River water elevations and flows in the Hanford Reach affect the environment and facilities along the shoreline, including movement of contaminants in groundwater, fish habitat, and infrastructure subject to flooding. This report describes the hydraulic simulation of hypothetical flood flows using the best available topographic and bathymetric data for the Hanford Reach and the Modular Aquatic Simulation System in 1 Dimension (MASS1) hydrodynamic model. The MASS1 model of the Hanford Reach was previously calibrated to field measurements of water surface elevations. The current model setup can be used for other studies of flow, water levels, and temperature in themore » Reach. The existing MASS1 channel geometry and roughness and other model configuration inputs for the Hanford Reach were used for this study, and previous calibration and validation results for the model are reprinted here for reference. The flood flows for this study were simulated by setting constant flow rates obtained from the U.S. Army Corps of Engineers (USACE) for the Columbia, Snake, and Yakima Rivers, and a constant water level at McNary Dam, and then running the model to steady state. The discharge levels simulated were all low-probability events; for example, a 100-year flood is one that would occur on average every 100 years, or put another way, in any given year there is a 1% chance that a discharge of that level or higher will occur. The simulated floods and their corresponding Columbia River discharges were 100-year (445,000 cfs), 500-year (520,000 cfs), and the USACE-defined Standard Project Flood (960,000 cfs). The resulting water levels from the steady-state floods can be viewed as “worst case” outcomes for the respective discharge levels. The MASS1 output for water surface elevations was converted to the North American Vertical Datum of 1988 and projected across the channel and land surface to enable mapping of the floodplain for each scenario. Floodplain maps show that for the 100-year and 500-year discharge levels, flooding is mainly confined to the topographic trench that is the river channel. The flooded area for the Standard Project Flood extends out of the channel area in some places, particularly in the 100-F Area. All of the output from the simulations have been archived and are available for future investigations in the Hanford Reach.« less

Contribution of water hyacinth (Eichhornia crassipes (Mart.) Solms) grown under different nutrient conditions to Fe-removal mechanisms in constructed wetlands.

PubMed

Jayaweera, Mahesh W; Kasturiarachchi, Jagath C; Kularatne, Ranil K A; Wijeyekoon, Suren L J

2008-05-01

Severe contamination of water resources including groundwater with iron (Fe) due to various anthropogenic activities has been a major environmental problem in industrial areas of Sri Lanka. Hence, the use of the obnoxious weed, water hyacinth (Eichhornia crassipes (Mart.) Solms) in constructed wetlands (floating aquatic macrophyte-based plant treatment systems) to phytoremediate Fe-rich wastewaters seems to be an appealing option. Although several studies have documented that hyacinths are good metal-accumulating plants none of these studies have documented the ability of this plant grown under different nutrient conditions to remove heavy metals from wastewaters. This paper, therefore, reports the phytoremediation efficiencies of water hyacinth grown under different nutrient conditions for Fe-rich wastewaters in batch-type constructed wetlands. This study was conducted for 15 weeks after 1-week acclimatization by culturing young water hyacinth plants (average height of 20+/-2cm) in 590L capacity fiberglass tanks under different nutrient concentrations of 1-fold [28 and 7.7mg/L of total nitrogen (TN) and total phosphorous (TP), respectively], 2-fold, 1/2-fold, 1/4-fold and 1/8-fold with synthetic wastewaters containing 9.27Femg/L. Another set-up of hyacinths containing only Fe as a heavy metal but without any nutrients (i.e., 0-fold) was also studied. A mass balance was carried out to investigate the phytoremediation efficiencies and to determine the different mechanisms governing Fe removal from the wastewaters. Fe removal was largely due to phytoremediation mainly through the process of rhizofiltration and chemical precipitation of Fe2O3 and FeOH3 followed by flocculation and sedimentation. However, chemical precipitation was more significant especially during the first 3 weeks of the study. Plants grown in the 0-fold set-up showed the highest phytoremediation efficiency of 47% during optimum growth at the 6th week with a highest accumulation of 6707Femg/kg dry weight. Active effluxing of Fe back to the wastewater at intermittent periods and with time was a key mechanism of avoiding Fe phytotoxicity in water hyacinth cultured in all set-ups. Our study elucidated that water hyacinth grown under nutrient-poor conditions are ideal to remove Fe from wastewaters with a hydraulic retention time of approximately 6 weeks.

Simplifiying global biogeochemistry models to evaluate methane emissions

NASA Astrophysics Data System (ADS)

Gerber, S.; Alonso-Contes, C.

2017-12-01

Process-based models are important tools to quantify wetland methane emissions, particularly also under climate change scenarios, evaluating these models is often cumbersome as they are embedded in larger land-surface models where fluctuating water table and the carbon cycle (including new readily decomposable plant material) are predicted variables. Here, we build on these large scale models but instead of modeling water table and plant productivity we provide values as boundary conditions. In contrast, aerobic and anaerobic decomposition, as well as soil column transport of oxygen and methane are predicted by the model. Because of these simplifications, the model has the potential to be more readily adaptable to the analysis of field-scale data. Here we determine the sensitivity of the model to specific setups, parameter choices, and to boundary conditions in order to determine set-up needs and inform what critical auxiliary variables need to be measured in order to better predict field-scale methane emissions from wetland soils. To that end we performed a global sensitivity analysis that also considers non-linear interactions between processes. The global sensitivity analysis revealed, not surprisingly, that water table dynamics (both mean level and amplitude of fluctuations), and the rate of the carbon cycle (i.e. net primary productivity) are critical determinants of methane emissions. The depth-scale where most of the potential decomposition occurs also affects methane emissions. Different transport mechanisms are compensating each other to some degree: If plant conduits are constrained, methane emissions by diffusive flux and ebullition compensate to some degree, however annual emissions are higher when plants help to bypass methanotrophs in temporally unsaturated upper layers. Finally, while oxygen consumption by plant roots help creating anoxic conditions it has little effect on overall methane emission. Our initial sensitivity analysis helps guiding further model development and improvement. However, an important goal for our model is to use it in field settings as a tool to deconvolve the different processes that contribute to the net transfer of methane from soils to atmosphere.

Hurricane-related air-sea interactions, circulation modifications, and coastal impacts on the eastern Louisiana coastline

NASA Astrophysics Data System (ADS)

Walker, N. D.; Pilley, C.; Li, C.; Liu, B.; Leben, R. R.; Raghunthan, V.; Ko, D.; Teague, W. J.

2012-12-01

Beginning in 1995, Atlantic hurricane activity increased significantly relative to the 1970s and 1980s. In 2005, records were broken when two hurricanes intensified rapidly to Category 5 for a period of time within the Gulf of Mexico, later landed, and flooded vast expanses of Louisiana's coastal regions within the span of 30 days. In this study, we investigate major hurricane events (including 2005) to elucidate air-sea interactions pertinent to hurricane intensity changes, shelf circulation, coastal flooding, and coastal land losses. We employ satellite measurements from passive sensors (temperature, true color, pigments) and active sensors (scatterometers, altimeters) in tandem with in-situ measurements from WAVCIS, NDBC, USGS, and NRL, as well as dedicated field campaigns along the coast. A selection of hurricane events during the 1998 to 2008 time period are used in this investigation. Research has shown that the Loop Current and its warm-core anticyclonic eddies (with high heat content) can intensify hurricanes transiting the Gulf; whereas, the cold-core cyclonic eddies (which are upwelling regions) can weaken hurricanes. Hurricane winds can intensify cold-core cyclonic eddies, which in some cases can impact outer shelf currents, mixing, and thermal structure throughout the water column. The exceptionally strong winds and waves in the northeast quadrant of these cyclonic atmospheric storms drive strong and long-lived westward currents. Storm surges and/or set-up of 2-6 m commonly occur along the Louisiana coastline, sometimes as a result of hurricanes traveling across the central Gulf of Mexico, at great distances from the coastal region experiencing the flooding (e.g. Hurricanes Rita and Gustav). The eastern shelf, north of the Mississippi River Birdfoot Delta, is particularly vulnerable to water level set-up and storm surge intensification due to the coastal orientation that causes the trapping of water. This area experienced land loss of 169 km2, or ~20%, due to extreme winds, waves and a storm surge of at least 6 m during Hurricane Katrina.

Laser-induced fluorescence detection platform for point-of-care testing

NASA Astrophysics Data System (ADS)

Berner, Marcel; Hilbig, Urs; Schubert, Markus B.; Gauglitz, Günter

2017-08-01

Point-of-care testing (POCT) devices for continuous low-cost monitoring of critical patient parameters require miniaturized and integrated setups for performing quick high-sensitivity analyses, away from central clinical laboratories. This work presents a novel and promising laser-induced fluorescence platform for measurements in direct optical test formats that leads towards such powerful POCT devices based on fluorescence-labeled immunoassays. Ultimate sensitivity of thin film photodetectors, integrated with microfluidics, and a comprehensive optimization of all system components aim at low-level signal detection in the targeted biosensor application. The setup acquires fluorescence signals from the volume of a microfluidic channel. An innovative sandwiching process forms a flow channel in the microfluidic chips by embedding laser-cut double-sided adhesive tapes. The custom fit of amorphous silicon based photodiode arrays to the geometry of the flow channel enables miniaturization, fully adequate for POCT devices. A free-beam laser excitation with line focus provides excellent alignment stability, allows for easy and reliable swapping of the disposable microfluidic chips, and therewith greatly improves the ease of use of the resulting integrated device. As a proof-of-concept of this novel in-volume measurement approach, the limit of detection for the dye DY636-COOH in pure water as a model fluorophore is examined and found to be 26 nmol l-1 .

Life on rock. Scaling down biological weathering in a new experimental design at Biosphere-2

NASA Astrophysics Data System (ADS)

Zaharescu, D. G.; Dontsova, K.; Burghelea, C. I.; Chorover, J.; Maier, R.; Perdrial, J. N.

2012-12-01

Biological colonization and weathering of bedrock on Earth is a major driver of landscape and ecosystem development, its effects reaching out into other major systems such climate and geochemical cycles of elements. In order to understand how microbe-plant-mycorrhizae communities interact with bedrock in the first phases of mineral weathering we developed a novel experimental design in the Desert Biome at Biosphere-2, University of Arizona (U.S.A). This presentation will focus on the development of the experimental setup. Briefly, six enclosed modules were designed to hold 288 experimental columns that will accommodate 4 rock types and 6 biological treatments. Each module is developed on 3 levels. A lower volume, able to withstand the weight of both, rock material and the rest of the structure, accommodates the sampling elements. A middle volume, houses the experimental columns in a dark chamber. A clear, upper section forms the habitat exposed to sunlight. This volume is completely sealed form exterior and it allows a complete control of its air and water parameters. All modules are connected in parallel with a double air purification system that delivers a permanent air flow. This setup is expected to provide a model experiment, able to test important processes in the interaction rock-life at grain-to- molecular scale.

Comparison of Fiber Optic and Conduit Attenuated Total Reflection (ATR) Fourier Transform Infrared (FT-IR) Setup for In-Line Fermentation Monitoring.

PubMed

Koch, Cosima; Posch, Andreas E; Herwig, Christoph; Lendl, Bernhard

2016-12-01

The performance of a fiber optic and an optical conduit in-line attenuated total reflection mid-infrared (IR) probe during in situ monitoring of Penicillium chrysogenum fermentation were compared. The fiber optic probe was connected to a sealed, portable, Fourier transform infrared (FT-IR) process spectrometer via a plug-and-play interface. The optical conduit, on the other hand, was connected to a FT-IR process spectrometer via a knuckled probe with mirrors that had to be adjusted prior to each fermentation, which were purged with dry air. Penicillin V (PenV) and its precursor phenoxyacetic acid (POX) concentrations were determined by online high-performance liquid chromatography and the obtained concentrations were used as reference to build partial least squares regression models. Cross-validated root-mean-square errors of prediction were found to be 0.2 g L -1 (POX) and 0.19 g L -1 (PenV) for the fiber optic setup and 0.17 g L -1 (both POX and PenV) for the conduit setup. Higher noise-levels and spectrum-to-spectrum variations of the fiber optic setup lead to higher noise of estimated (i.e., unknown) POX and PenV concentrations than was found for the conduit setup. It seems that trade-off has to be made between ease of handling (fiber optic setup) and measurement accuracy (optical conduit setup) when choosing one of these systems for bioprocess monitoring. © The Author(s) 2016.

Thai National Telescope beam simulator testbed development status

NASA Astrophysics Data System (ADS)

Buisset, Christophe; Prasit, Apirat; Lépine, Thierry; Poshyachinda, Saran; Leckngam, A.

2016-07-01

The Thai National Telescope (TNT) is a Ritchey-Chretien Telescope with a clear aperture ΦM1 = 2.3 m, a focal ratio f/10 and a central obstruction Obsc = 0.3. The TNT is the main instrument of the Thai National Observatory (TNO) which is located near the summit of the Doi Inthanon, situated in the Chiang Mai Province of Thailand at altitude 2,457 meters. The median seeing on this site is approximately 0.9" and is remarkably stable on most nights, rarely exceeding 2". We decided to develop an optical setup to simulate in laboratory conditions the geometry of the TNT output beam. This, in order to carefully prepare and to improve the efficiency of the test to be performed in real conditions at the TNT focal plane level. We specified the setup to be representative of the TNT optical design, beam aperture, central obscuration, geometry of the spider, wavefront quality and PSF size under various seeing conditions. This setup comprises 2 identical Cassegrain telescopes mounted on dedicated supports with 5 degree-of-Freedom. The first application of this setup will be the preparation of the TNT optical alignment. The second application of this setup will be the development and the test of the future instruments for the TNT such as a focal reducer or a spectrograph. In this paper, we discuss the setup specifications we describe the setup optical and mechanical design and we present the performance.

Laboratory-based micro-X-ray fluorescence setup using a von Hamos crystal spectrometer and a focused beam X-ray tube

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kayser, Y., E-mail: yves.kayser@psi.ch; Paul Scherrer Institut, 5232 Villigen-PSI; Błachucki, W.

2014-04-15

The high-resolution von Hamos bent crystal spectrometer of the University of Fribourg was upgraded with a focused X-ray beam source with the aim of performing micro-sized X-ray fluorescence (XRF) measurements in the laboratory. The focused X-ray beam source integrates a collimating optics mounted on a low-power micro-spot X-ray tube and a focusing polycapillary half-lens placed in front of the sample. The performances of the setup were probed in terms of spatial and energy resolution. In particular, the fluorescence intensity and energy resolution of the von Hamos spectrometer equipped with the novel micro-focused X-ray source and a standard high-power water-cooled X-raymore » tube were compared. The XRF analysis capability of the new setup was assessed by measuring the dopant distribution within the core of Er-doped SiO{sub 2} optical fibers.« less

Quantifying the transport properties of lipid mesophases by theoretical modelling of diffusion experiments

NASA Astrophysics Data System (ADS)

Antognini, Luca M.; Assenza, Salvatore; Speziale, Chiara; Mezzenga, Raffaele

2016-08-01

Lyotropic Liquid Crystals (LLCs) are a class of lipid-based membranes with a strong potential for drug-delivery employment. The characterization and control of their transport properties is a central issue in this regard, and has recently prompted a notable volume of research on the topic. A promising experimental approach is provided by the so-called diffusion setup, where the drug molecules diffuse from a feeding chamber filled with water to a receiving one passing through a LLC. In the present work we provide a theoretical framework for the proper description of this setup, and validate it by means of targeted experiments. Due to the inhomogeneity of the system, a rich palette of different diffusion dynamics emerges from the interplay of the different time- and lengthscales thereby present. Our work paves the way to the employment of diffusion experiments to quantitatively characterize the transport properties of LLCs, and provides the basic tools for device diffusion setups with controlled kinetic properties.

Systematic testing of flood adaptation options in urban areas through simulations

NASA Astrophysics Data System (ADS)

Löwe, Roland; Urich, Christian; Sto. Domingo, Nina; Mark, Ole; Deletic, Ana; Arnbjerg-Nielsen, Karsten

2016-04-01

While models can quantify flood risk in great detail, the results are subject to a number of deep uncertainties. Climate dependent drivers such as sea level and rainfall intensities, population growth and economic development all have a strong influence on future flood risk, but future developments can only be estimated coarsely. In such a situation, robust decision making frameworks call for the systematic evaluation of mitigation measures against ensembles of potential futures. We have coupled the urban development software DAnCE4Water and the 1D-2D hydraulic simulation package MIKE FLOOD to create a framework that allows for such systematic evaluations, considering mitigation measures under a variety of climate futures and urban development scenarios. A wide spectrum of mitigation measures can be considered in this setup, ranging from structural measures such as modifications of the sewer network over local retention of rainwater and the modification of surface flow paths to policy measures such as restrictions on urban development in flood prone areas or master plans that encourage compact development. The setup was tested in a 300 ha residential catchment in Melbourne, Australia. The results clearly demonstrate the importance of considering a range of potential futures in the planning process. For example, local rainwater retention measures strongly reduce flood risk a scenario with moderate increase of rain intensities and moderate urban growth, but their performance strongly varies, yielding very little improvement in situations with pronounced climate change. The systematic testing of adaptation measures further allows for the identification of so-called adaptation tipping points, i.e. levels for the drivers of flood risk where the desired level of flood risk is exceeded despite the implementation of (a combination of) mitigation measures. Assuming a range of development rates for the drivers of flood risk, such tipping points can be translated into anticipated time spans over which a measure will be effective. While the new simulation setup is limited to situations where the planner is able to define realistic ranges for the development of drivers of flood risk, it certainly contributes to an improved consideration of deep uncertainties in the planning process. Future work will particularly focus on the application of the framework in a variety of urban development contexts.

A periodic review integrated inventory model with controllable safety stock and setup cost under service level constraint and distribution-free demand

NASA Astrophysics Data System (ADS)

Kurdhi, N. A.; Jamaluddin, A.; Jauhari, W. A.; Saputro, D. R. S.

2017-06-01

In this study, we consider a stochastic integrated manufacturer-retailer inventory model with service level constraint. The model analyzed in this article considers the situation in which the vendor and the buyer establish a long-term contract and strategic partnership to jointly determine the best strategy. The lead time and setup cost are assumed can be controlled by an additional crashing cost and an investment, respectively. It is assumed that shortages are allowed and partially backlogged on the buyer’s side, and that the protection interval (i.e., review period plus lead time) demand distribution is unknown but has given finite first and second moments. The objective is to apply the minmax distribution free approach to simultaneously optimize the review period, the lead time, the setup cost, the safety factor, and the number of deliveries in order to minimize the joint total expected annual cost. The service level constraint guarantees that the service level requirement can be satisfied at the worst case. By constructing Lagrange function, the analysis regarding the solution procedure is conducted, and a solution algorithm is then developed. Moreover, a numerical example and sensitivity analysis are given to illustrate the proposed model and to provide some observations and managerial implications.

Polymer mobilization and drug release during tablet swelling. A 1H NMR and NMR microimaging study.

PubMed

Dahlberg, Carina; Fureby, Anna; Schuleit, Michael; Dvinskikh, Sergey V; Furó, István

2007-09-26

The objective of this study was to investigate the swelling characteristics of a hydroxypropyl methylcellulose (HPMC) matrix incorporating the hydrophilic drug antipyrine. We have used this matrix to introduce a novel analytical method, which allows us to obtain within one experimental setup information about the molecular processes of the polymer carrier and its impact on drug release. Nuclear magnetic resonance (NMR) imaging revealed in situ the swelling behavior of tablets when exposed to water. By using deuterated water, the spatial distribution and molecular dynamics of HPMC and their kinetics during swelling could be observed selectively. In parallel, NMR spectroscopy provided the concentration of the drug released into the aqueous phase. We find that both swelling and release are diffusion controlled. The ability of monitoring those two processes using the same experimental setup enables mapping their interconnection, which points on the importance and potential of this analytical technique for further application in other drug delivery forms.

Hygroscopic analysis of individual Beijing haze aerosol particles by environmental scanning electron microscopy

NASA Astrophysics Data System (ADS)

Bai, Zhangpeng; Ji, Yuan; Pi, Yiqun; Yang, Kaixiang; Wang, Li; Zhang, Yinqi; Zhai, Yadi; Yan, Zhengguang; Han, Xiaodong

2018-01-01

Investigating the hygroscopic behavior of haze aerosol particles is essential for understanding their physicochemical properties and their impacts on regional weather and visibility. An environmental scanning electron microscope equipped with a home-made transmission-scattering electron imaging setup and an energy dispersive spectrometer was used for in-situ observations of pure water-soluble (WS) salts and Beijing haze particles. This imaging setup showed obvious advantages for improving the resolution and acquiring internal information of mixed particles in hydrated environments. We measured the deliquescence relative humidity of pure NaCl, NH4NO3, and (NH4)2SO4 by deliquescence-crystallization processes with an accuracy of up to 0.3% RH. The mixed haze particles showed hygroscopic activation like water uptake and morphological changes when they included WS components such as nitrates, sulfates, halides, ammoniums, and alkali metal salts. In addition, the hygroscopic behavior provides complementary information for analyzing possible phases in mixed haze particles.

Optical Waveguide Lightmode Spectroscopic Techniques for Investigating Membrane-Bound Ion Channel Activities

PubMed Central

Székács, Inna; Kaszás, Nóra; Gróf, Pál; Erdélyi, Katalin; Szendrő, István; Mihalik, Balázs; Pataki, Ágnes; Antoni, Ferenc A.; Madarász, Emilia

2013-01-01

Optical waveguide lightmode spectroscopic (OWLS) techniques were probed for monitoring ion permeation through channels incorporated into artificial lipid environment. A novel sensor set-up was developed by depositing liposomes or cell-derived membrane fragments onto hydrophilic polytetrafluoroethylene (PTFE) membrane. The fibrous material of PTFE membrane could entrap lipoid vesicles and the water-filled pores provided environment for the hydrophilic domains of lipid-embedded proteins. The sensor surface was kept clean from the lipid holder PTFE membrane by a water- and ion-permeable polyethylene terephthalate (PET) mesh. The sensor set-up was tested with egg yolk lecithin liposomes containing gramicidin ion channels and with cell-derived membrane fragments enriched in GABA-gated anion channels. The method allowed monitoring the move of Na+ and organic cations through gramicidin channels and detecting the Cl–-channel functions of the (α5β2γ2) GABAA receptor in the presence or absence of GABA and the competitive GABA-blocker bicuculline. PMID:24339925

Design of an experimental apparatus for measurement of the surface tension of metastable fluids

NASA Astrophysics Data System (ADS)

Vinš, V.; Hrubý, J.; Hykl, J.; Blaha, J.; Šmíd, B.

2013-04-01

A unique experimental apparatus for measurement of the surface tension of aqueous mixtures has been designed, manufactured, and tested in our laboratory. The novelty of the setup is that it allows measurement of surface tension by two different methods: a modified capillary elevation method in a long vertical capillary tube and a method inspired by the approach of Hacker (National Advisory Committee for Aeronautics, Technical Note 2510, 1-20, 1951), i.e. in a short horizontal capillary tube. Functionality of all main components of the apparatus, e.g., glass chamber with the capillary tube, temperature control unit consisting of two thermostatic baths with special valves for rapid temperature jumps, helium distribution setup allowing pressure variation above the liquid meniscus inside the capillary tube, has been successfully tested. Preliminary results for the surface tension of the stable and metastable supercooled water measured by the capillary elevation method at atmospheric pressure are provided. The surface tension of water measured at temperatures between +26 °C and -11 °C is in good agreement with the extrapolated IAPWS correlation (IAPWS Release on Surface Tension of Ordinary Water Substance, September 1994); however it disagrees with data by Hacker.

Practical Use of the Extended No Action Level (eNAL) Correction Protocol for Breast Cancer Patients With Implanted Surgical Clips

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penninkhof, Joan, E-mail: j.penninkhof@erasmusmc.nl; Quint, Sandra; Baaijens, Margreet

Purpose: To describe the practical use of the extended No Action Level (eNAL) setup correction protocol for breast cancer patients with surgical clips and evaluate its impact on the setup accuracy of both tumor bed and whole breast during simultaneously integrated boost treatments. Methods and Materials: For 80 patients, two orthogonal planar kilovoltage images and one megavoltage image (for the mediolateral beam) were acquired per fraction throughout the radiotherapy course. For setup correction, the eNAL protocol was applied, based on registration of surgical clips in the lumpectomy cavity. Differences with respect to application of a No Action Level (NAL) protocolmore » or no protocol were quantified for tumor bed and whole breast. The correlation between clip migration during the fractionated treatment and either the method of surgery or the time elapsed from last surgery was investigated. Results: The distance of the clips to their center of mass (COM), averaged over all clips and patients, was reduced by 0.9 {+-} 1.2 mm (mean {+-} 1 SD). Clip migration was similar between the group of patients starting treatment within 100 days after surgery (median, 53 days) and the group starting afterward (median, 163 days) (p = 0.20). Clip migration after conventional breast surgery (closing the breast superficially) or after lumpectomy with partial breast reconstructive techniques (sutured cavity). was not significantly different either (p = 0.22). Application of eNAL on clips resulted in residual systematic errors for the clips' COM of less than 1 mm in each direction, whereas the setup of the breast was within about 2 mm of accuracy. Conclusions: Surgical clips can be safely used for high-accuracy position verification and correction. Given compensation for time trends in the clips' COM throughout the treatment course, eNAL resulted in better setup accuracies for both tumor bed and whole breast than NAL.« less

Root Water Uptake and Soil Moisture Pattern Dynamics - Capturing Connections, Controls and Causalities

NASA Astrophysics Data System (ADS)

Blume, T.; Heidbuechel, I.; Hassler, S. K.; Simard, S.; Guntner, A.; Stewart, R. D.; Weiler, M.

2015-12-01

We hypothesize that there is a shift in controls on landscape scale soil moisture patterns when plants become active during the growing season. Especially during the summer soil moisture patterns are not only controlled by soils, topography and related abiotic site characteristics but also by root water uptake. Root water uptake influences soil moisture patterns both in the lateral and vertical direction. Plant water uptake from different soil depths is estimated based on diurnal fluctuations in soil moisture content and was investigated with a unique setup of 46 field sites in Luxemburg and 15 field sites in Germany. These sites cover a range of geologies, soils, topographic positions and types of vegetation. Vegetation types include pasture, pine forest (young and old) and different deciduous forest stands. Available data at all sites includes information at high temporal resolution from 3-5 soil moisture and soil temperature profiles, matrix potential, piezometers and sapflow sensors as well as standard climate data. At sites with access to a stream, discharge or water level is also recorded. The analysis of soil moisture patterns over time indicates a shift in regime depending on season. Depth profiles of root water uptake show strong differences between different forest stands, with maximum depths ranging between 50 and 200 cm. Temporal dynamics of signal strength within the profile furthermore suggest a locally shifting spatial distribution of root water uptake depending on water availability. We will investigate temporal thresholds (under which conditions spatial patterns of root water uptake become most distinct) as well as landscape controls on soil moisture and root water uptake dynamics.

Dynamics of flood water infiltration and ground water recharge in hyperarid desert.

PubMed

Dahan, Ofer; Tatarsky, Boaz; Enzel, Yehouda; Kulls, Christoph; Seely, Mary; Benito, Gererdo

2008-01-01

A study on flood water infiltration and ground water recharge of a shallow alluvial aquifer was conducted in the hyperarid section of the Kuiseb River, Namibia. The study site was selected to represent a typical desert ephemeral river. An instrumental setup allowed, for the first time, continuous monitoring of infiltration during a flood event through the channel bed and the entire vadose zone. The monitoring system included flexible time domain reflectometry probes that were designed to measure the temporal variation in vadose zone water content and instruments to concurrently measure the levels of flood and ground water. A sequence of five individual floods was monitored during the rainy season in early summer 2006. These newly generated data served to elucidate the dynamics of flood water infiltration. Each flood initiated an infiltration event which was expressed in wetting of the vadose zone followed by a measurable rise in the water table. The data enabled a direct calculation of the infiltration fluxes by various independent methods. The floods varied in their stages, peaks, and initial water contents. However, all floods produced very similar flux rates, suggesting that the recharge rates are less affected by the flood stages but rather controlled by flow duration and available aquifer storage under it. Large floods flood the stream channel terraces and promote the larger transmission losses. These, however, make only a negligible contribution to the recharge of the ground water. It is the flood duration within the active streambed, which may increase with flood magnitude that is important to the recharge process.

A technique for the measurement of organic aerosol hygroscopicity, oxidation level, and volatility distributions

NASA Astrophysics Data System (ADS)

Cain, Kerrigan P.; Pandis, Spyros N.

2017-12-01

Hygroscopicity, oxidation level, and volatility are three crucial properties of organic pollutants. This study assesses the feasibility of a novel measurement and analysis technique to determine these properties and establish their relationship. The proposed experimental setup utilizes a cloud condensation nuclei (CCN) counter to quantify hygroscopic activity, an aerosol mass spectrometer to measure the oxidation level, and a thermodenuder to evaluate the volatility. The setup was first tested with secondary organic aerosol (SOA) formed from the ozonolysis of α-pinene. The results of the first experiments indicated that, for this system, the less volatile SOA contained species that had on average lower O : C ratios and hygroscopicities. In this SOA system, both low- and high-volatility components can have comparable oxidation levels and hygroscopicities. The method developed here can be used to provide valuable insights about the relationships among organic aerosol hygroscopicity, oxidation level, and volatility.

Modelling Growth and Form of the Scleractinian Coral Pocillopora verrucosa and the Influence of Hydrodynamics

PubMed Central

Chindapol, Nol; Kaandorp, Jaap A.; Cronemberger, Carolina; Mass, Tali; Genin, Amatzia

2013-01-01

The growth of scleractinian corals is strongly influenced by the effect of water motion. Corals are known to have a high level of phenotypic variation and exhibit a diverse range of growth forms, which often contain a high level of geometric complexity. Due to their complex shape, simulation models represent an important option to complement experimental studies of growth and flow. In this work, we analyzed the impact of flow on coral's morphology by an accretive growth model coupled with advection-diffusion equations. We performed simulations under no-flow and uni-directional flow setup with the Reynolds number constant. The relevant importance of diffusion to advection was investigated by varying the diffusion coefficient, rather than the flow speed in Péclet number. The flow and transport equations were coupled and solved using COMSOL Multiphysics. We then compared the simulated morphologies with a series of Computed Tomography (CT) scans of scleractinian corals Pocillopora verrucosa exposed to various flow conditions in the in situ controlled flume setup. As a result, we found a similar trend associated with the increasing Péclet for both simulated forms and in situ corals; that is uni-directional current tends to facilitate asymmetrical growth response resulting in colonies with branches predominantly developed in the upstream direction. A closer look at the morphological traits yielded an interesting property about colony symmetry and plasticity induced by uni-directional flow. Both simulated and in situ corals exhibit a tendency where the degree of symmetry decreases and compactification increases in conjunction with the augmented Péclet thus indicates the significant importance of hydrodynamics. PMID:23326222

Mid-Infrared Photoacoustic Detection of Glucose in Human Skin: Towards Non-Invasive Diagnostics

PubMed Central

Kottmann, Jonas; Rey, Julien M.; Sigrist, Markus W.

2016-01-01

Diabetes mellitus is a widespread metabolic disease without cure. Great efforts are being made to develop a non-invasive monitoring of the blood glucose level. Various attempts have been made, including a number of non-optical approaches as well as optical techniques involving visible, near- and mid-infrared light. However, no true breakthrough has been achieved so far, i.e., there is no fully non-invasive monitoring device available. Here we present a new study based on mid-infrared spectroscopy and photoacoustic detection. We employ two setups, one with a fiber-coupled photoacoustic (PA) cell and a tunable quantum cascade laser (QCL), and a second setup with two QCLs at different wavelengths combined with PA detection. In both cases, the PA cells are in direct skin contact. The performance is tested with an oral glucose tolerance test. While the first setup often gives reasonable qualitative agreement with ordinary invasive blood glucose measurements, the dual-wavelength approach yields a considerably improved stability and an uncertainty of only ±30 mg/dL of the blood glucose concentration level at a confidence level of 90%. This result is achieved without advanced data treatment such as principal component analysis involving extended wavelength ranges. PMID:27735878

COMPARISON OF LAPAROSCOPIC SKILLS PERFORMANCE USING SINGLE-SITE ACCESS (SSA) DEVICES VS. AN INDEPENDENT-PORT SSA APPROACH

PubMed Central

Schill, Matthew R.; Varela, J. Esteban; Frisella, Margaret M.; Brunt, L. Michael

2015-01-01

Background We compared performance of validated laparoscopic tasks on four commercially available single site access (SSA) access devices (AD) versus an independent port (IP) SSA set-up. Methods A prospective, randomized comparison of laparoscopic skills performance on four AD (GelPOINT™, SILS™ Port, SSL Access System™, TriPort™) and one IP SSA set-up was conducted. Eighteen medical students (2nd–4th year), four surgical residents, and five attending surgeons were trained to proficiency in multi-port laparoscopy using four laparoscopic drills (peg transfer, bean drop, pattern cutting, extracorporeal suturing) in a laparoscopic trainer box. Drills were then performed in random order on each IP-SSA and AD-SSA set-up using straight laparoscopic instruments. Repetitions were timed and errors recorded. Data are mean ± SD, and statistical analysis was by two-way ANOVA with Tukey HSD post-hoc tests. Results Attending surgeons had significantly faster total task times than residents or students (p< 0.001), but the difference between residents and students was NS. Pair-wise comparisons revealed significantly faster total task times for the IP-SSA set-up compared to all four AD-SSA’s within the student group only (p<0.05). Total task times for residents and attending surgeons showed a similar profile, but the differences were NS. When data for the three groups was combined, the total task time was less for the IP-SSA set-up than for each of the four AD-SSA set-ups (p < 0.001). Similarly,, the IP-SSA set-up was significantly faster than 3 of 4 AD-SSA set-ups for peg transfer, 3 of 4 for pattern cutting, and 2 of 4 for suturing. No significant differences in error rates between IP-SSA and AD-SSA set-ups were detected. Conclusions When compared to an IP-SSA laparoscopic set-up, single site access devices are associated with longer task performance times in a trainer box model, independent of level of training. Task performance was similar across different SSA devices. PMID:21993938

A New Look for Coriolis.

ERIC Educational Resources Information Center

Levi, F. A.

1988-01-01

Describes a demonstration of Coriolis acceleration. Discusses two different meanings of "Coriolis" and two causes of Coriolis acceleration. Gives a set-up method of the demonstration apparatus by using a rotary disk with rubber tubing for tap water, switches, lamps, battery, and counterweight. Provides two pictures with operating method.…

IMPACT OF WATER CHEMISTRY ON MANGANESE REMOVAL DURING OXIDATION/FILTRATION TREATMENT

EPA Science Inventory

This is a poster showing the purpose and setup of our pilot plant experiments with manganese filtration. The focus is on the differences, effectiveness, and problems with using chlorine and potassium permanganate in oxidation/filtration. The poster will show the results and findi...

Ab initio simulations of water splitting on hematite

NASA Astrophysics Data System (ADS)

Seriani, Nicola

2017-11-01

In recent years, hematite has attracted great interest as a photocatalyst for water splitting, but many questions remain unanswered about the mechanisms and the main limiting factors. For this reason, density functional theory has been used to understand the optical, electronic and chemical properties of this material at an atomistic level. Bulk doping can be used to reduce the band gap, and to increase photoabsorption and charge mobility. Charge transport takes place through adiabatic polaron hopping. The stable (0 0 0 1) surface has a stoichiometric termination when exposed to oxygen, it becomes hydroxylated in water, and it has an oxygen-rich termination under illumination in a photoelectrochemical setup. On the oxygen-rich termination, surface states are present that might act as recombination centres for electrons and holes. On the contrary, on the hydroxylated termination surface states appear only on reaction intermediates. The intrinsic surface states disappear in the presence of an overlayer of gallium oxide. The reaction of water oxidation is assumed to proceed by four proton-coupled electron transfers and it is shown to involve a nucleophilic attack with the formation of an OOH group. Calculated overpotentials are in the range of 0.5-0.6 V. Open questions and future research directions are briefly discussed.

The abiotic environment of the interstitial of a small Swiss river in the foothills of the Alps and its influence on gravel spawning brown trout (Salmo trutta L.)

NASA Astrophysics Data System (ADS)

Schindler, Yael; Michel, Christian; Holm, Patricia; Alewell, Christine

2010-05-01

The hyporheic zone can be characterized by multiple abiotic parameters (e.g. bulk density, texture, temperature, oxygen, ammonium, nitrate) which are all influenced directly or indirectly by the exchange processes between surface water and groundwater. These processes can vary both in time and space and are mainly driven by river discharge, ground water level and flow patterns. The input of fine sediment particles can change water-riverbed interactions through river bed clogging potentially affecting the embryonal development and survival of gravel spawning fish, such as brown trout (Salmo trutta L.). With our investigations we aim to understand these complex interactions spatially and temporally on a relevant small scale, i.e. within individual artificial brown trout redds. We designed an experimental field setup to directly investigate i) the influence of the abiotic river and redd environment on brown trout embryo development and ii) the hydrological dynamics affecting the abiotic environment in artificial brown trout. Additionally, our setup allows investigating the temporal dynamics of i) fine-sediment infiltration into the artificial redds and ii) embryo survival to two distinct developmental stages (i.e. eyed stage and hatch) The experiment was conducted in three sites of a typical Swiss river (Enziwigger, Canton of Luzern) with a strongly modified morphology. Individual sites represented a high, medium and low fine-sediment load. In each site, six artificial redds (18 in total) were built and data were collected during the entire incubation phase. Redds were located in places where natural spawning of brown trout is present. We adapted multiple established methods to the smaller scale of our river to study the dynamics of the most relevant abiotic parameters potentially affecting embryo development: Oxygen content and temperature was monitored continuously in different depths, fine sediment (bedload, suspended sediment load and its input in the river bed) was measured weekly and water samples for DOC and nitrogen components analysis were collected regularly. In addition, all redds were equipped with mini piezometers to measure the hydraulic gradient through the redds. Finally, water stage and turbidity were monitored continuously. Results of the first spawning season will be presented. Dynamic of abiotic parameters and their influence on spawning of brown trout will be discussed.

Characterization of a multi-axis ion chamber array.

PubMed

Simon, Thomas A; Kozelka, Jakub; Simon, William E; Kahler, Darren; Li, Jonathan; Liu, Chihray

2010-11-01

The aim of this work was to characterize a multi-axis ion chamber array (IC PROFILER; Sun Nuclear Corporation, Melbourne, FL, USA) that has the potential to simplify the acquisition of LINAC beam data. The IC PROFILER (or panel) measurement response was characterized with respect to radiation beam properties, including dose, dose per pulse, pulse rate frequency (PRF), and energy. Panel properties were also studied, including detector-calibration stability, power-on time, backscatter dependence, and the panel's agreement with water tank measurements [profiles, fractional depth dose (FDD), and output factors]. The panel's relative deviation was typically within (+/-) 1% of an independent (or nominal) response for all properties that were tested. Notable results were (a) a detectable relative field shape change of approximately 1% with linear accelerator PRF changes; (b) a large range in backscatter thickness had a minimal effect on the measured dose distribution (typically less than 1%); (c) the error spread in profile comparison between the panel and scanning water tank (Blue Phantom, CC13; IBA Schwarzenbruck, DE) was approximately (+/-) 0.75%. The ability of the panel to accurately reproduce water tank profiles, FDDs, and output factors is an indication of its abilities as a dosimetry system. The benefits of using the panel versus a scanning water tank are less setup time and less error susceptibility. The same measurements (including device setup and breakdown) for both systems took 180 min with the water tank versus 30 min with the panel. The time-savings increase as the measurement load is increased.

Integrating biofiltration with SVE: A case study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lesley, M.P.; Rangan, C.R.

1996-12-01

A prototype integrated soil vacuum extraction/biofiltration system has been designed and installed at a gasoline contaminated LUST site in southern Delaware. The prototype system remediates contaminated moisture entrained in the air stream, employs automatic water level controls in the filters, and achieves maximum vapor extraction and VOC destruction efficiency with an optimum power input. In addition, the valving and piping layout allows the direction of air flow through the filters to be reversed at a given time interval, which minimizes biofouling, thereby increasing efficiency by minimizing the need for frequent cleaning. This integrated system achieves constant VOC destruction rates ofmore » 40 to 70% while maintaining optimal VOC removal rates from the subsurface. The modular design allows for easy mobilization, setup and demobilization at state-lead LUST sites throughout Delaware.« less

Direct injection GC method for measuring light hydrocarbon emissions from cooling-tower water.

PubMed

Lee, Max M; Logan, Tim D; Sun, Kefu; Hurley, N Spencer; Swatloski, Robert A; Gluck, Steve J

2003-12-15

A Direct Injection GC method for quantifying low levels of light hydrocarbons (C6 and below) in cooling water has been developed. It is intended to overcome the limitations of the currently available technology. The principle of this method is to use a stripper column in a GC to strip waterfrom the hydrocarbons prior to entering the separation column. No sample preparation is required since the water sample is introduced directly into the GC. Method validation indicates that the Direct Injection GC method offers approximately 15 min analysis time with excellent precision and recovery. The calibration studies with ethylene and propylene show that both liquid and gas standards are suitable for routine calibration and calibration verification. The sampling method using zero headspace traditional VOA (Volatile Organic Analysis) vials and a sample chiller has also been validated. It is apparent that the sampling method is sufficient to minimize the potential for losses of light hydrocarbons, and samples can be held at 4 degrees C for up to 7 days with more than 93% recovery. The Direct Injection GC method also offers <1 ppb (w/v) level method detection limits for ethylene, propylene, and benzene. It is superior to the existing El Paso stripper method. In addition to lower detection limits for ethylene and propylene, the Direct Injection GC method quantifies individual light hydrocarbons in cooling water, provides better recoveries, and requires less maintenance and setup costs. Since the instrumentation and supplies are readily available, this technique could easily be established as a standard or alternative method for routine emission monitoring and leak detection of light hydrocarbons in cooling-tower water.

Simulating groundwater-induced sewer flooding

NASA Astrophysics Data System (ADS)

Mijic, A.; Mansour, M.; Stanic, M.; Jackson, C. R.

2016-12-01

During the last decade, Chalk catchments of southern England experienced severe groundwater flooding. High groundwater levels resulted in the groundwater ingress into the sewer network that led to restricted toilet use and the overflow of diluted, but untreated sewage to road surfaces, rivers and water courses. In response to these events the water and sewerage company Thames Water Utilities Ltd (TWUL) had to allocate significant funds to mitigate the impacts. It was estimated that approximately £19m was spent responding to the extreme wet weather of 2013-14, along with the use of a fleet of over 100 tankers. However, the magnitude of the event was so large that these efforts could not stop the discharge of sewage to the environment. This work presents the analysis of the risk of groundwater-induced sewer flooding within the Chalk catchment of the River Lambourn, Berkshire. A spatially distributed groundwater model was used to assess historic groundwater flood risk and the potential impacts of changes in future climate. We then linked this model to an urban groundwater model to enable us to simulate groundwater-sewer interaction in detail. The modelling setup was used to identify relationships between infiltration into sewers and groundwater levels at specific points on TWUL's sewer network, and to estimate historic and future groundwater flood risk, and how this varies across the catchment. The study showed the significance of understanding the impact of groundwater on the urban water systems, and producing information that can inform a water company's response to groundwater flood risk, their decision making process and their asset management planning. However, the knowledge gained through integrated modelling of groundwater-sewer interactions has highlighted limitations of existing approaches for the simulation of these coupled systems. We conclude this work with number of recommendations about how to improve such hydrological/sewer analysis.

Measuring the radioactivity of drinking water with the liquid counters M2H in combination with contamination meters IM 4457

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vanhemmen, J.J.; Vanhoek, L.P.; Aten, J.B.T.

1976-01-01

The relationship between the meter indications and the radioactivity of fission products in drinking water for the combination contamination meter IM 4457 and liquid counter M2H was investigated. The experimental setup is presented, the efficiency of the liquid counter for a mixture of fission products is briefly dealt with, and the use of the combination counter/meter in the field is discussed.

Large Volume Non-Equilibrium Air Plasma at Atmospheric Pressure: A Novel Method with Low Power Requirements

DTIC Science & Technology

2007-02-28

of magnitude in size. Also unlike corona -like devices such as the plasma needle , which generates 2-3 mm long plasma at the tip of a sharp wire...Distribution Unlimited Table of Contents Abstract AC System with Water Electrode Current voltage characteristics Plasma diagnostics results Experimental setup...Laroussi, PI. 4 AC SYSTEM WITH WATER ELECTRODE Recently, non-equilibrium atmospheric pressure plasmas have been used in a variety of material processing

Noninvasive measurement of wave speed of porcine cornea in ex vivo porcine eyes for various intraocular pressures.

PubMed

Zhou, Boran; Sit, Arthur J; Zhang, Xiaoming

2017-11-01

The objective of this study was to extend an ultrasound surface wave elastography (USWE) technique for noninvasive measurement of ocular tissue elastic properties. In particular, we aim to establish the relationship between the wave speed of cornea and the intraocular pressure (IOP). Normal ranges of IOP are between 12 and 22mmHg. Ex vivo porcine eye balls were used in this research. The porcine eye ball was supported by the gelatin phantom in a testing container. Some water was pour into the container for the ultrasound measurement. A local harmonic vibration was generated on the side of the eye ball. An ultrasound probe was used to measure the wave propagation in the cornea noninvasively. A 25 gauge butterfly needle was inserted into the vitreous humor of the eye ball under the ultrasound imaging guidance. The needle was connected to a syringe. The IOP was obtained by the water height difference between the water level in the syringe and the water level in the testing container. The IOP was adjusted between 5mmHg and 30mmHg with a 5mmHg interval. The wave speed was measured at each IOP for three frequencies of 100, 150 and 200Hz. Finite element method (FEM) was used to simulate the wave propagation in the corneal according to our experimental setup. A linear viscoelastic FEM model was used to compare the experimental data. Both the experiments and the FEM analyses showed that the wave speed of cornea increased with IOP. Copyright © 2017 Elsevier B.V. All rights reserved.

A study of surface dosimetry for breast cancer radiotherapy treatments using Gafchromic EBT2 film

PubMed Central

Hill, Robin F.; Whitaker, May; Kim, Jung‐Ha; Kuncic, Zdenka

2012-01-01

The present study quantified surface doses on several rectangular phantom setups and on curved surface phantoms for a 6 MV photon field using the Attix parallel‐plate chamber and Gafchromic EBT2 film. For the rectangular phantom setups, the surface doses on a homogenous water equivalent phantom and a water equivalent phantom with 60 mm thick lung equivalent material were measured. The measurement on the homogenous phantom setup showed consistency in surface and near‐surface doses between an open field and enhanced dynamic wedge (EDW) fields, whereas physical wedged fields showed small differences. Surface dose measurements made using the EBT2 film showed good agreement with results of the Attix chamber and results obtained in previous studies which used other dosimeters within the measurement uncertainty of 3.3%. The surface dose measurements on the phantom setup with lung equivalent material showed a small increase without bolus and up to 6.9% increase with bolus simulating the increase of chest wall thickness. Surface doses on the cylindrical CT phantom and customized Perspex chest phantom were measured using the EBT2 film with and without bolus. The results indicate the important role of the presence of bolus if the clinical target volume (CTV) is quite close to the surface. Measurements on the cylindrical phantom suggest that surface doses at the oblique positions of 60° and 90° are mainly caused by the lateral scatter from the material inside the phantom. In the case of a single tangential irradiation onto Perspex chest phantom, the distribution of the surface dose with and without bolus materials showed opposing inclination patterns, whereas the dose distribution for two opposed tangential fields gave symmetric dose distribution. This study also demonstrates the suitability of Gafchromic EBT2 film for surface dose measurements in megavoltage photon beams. PACS number: 87.53.Bn PMID:22584169

SDMProjectBuilder: SWAT Setup for Nutrient Fate and Transport

EPA Science Inventory

This tutorial reviews some of the screens, icons, and basic functions of the SDMProjectBuilder (SDMPB) and explains how one uses SDMPB output to populate the Soil and Water Assessment Tool (SWAT) input files for nutrient fate and transport modeling in the Salt River Basin. It dem...

7 CFR 1924.253 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... structural defect. (d) Structural defect. A defect in the dwelling or unit, installation or set-up of a unit... of the dwelling or unit or site such as faulty wiring, or failure of sewage disposal or water supply systems located on the property securing the loan caused by faulty materials or improper installation. (3...

Raindrop and flow interactions for interrill erosion with wind-driven rain

USDA-ARS?s Scientific Manuscript database

Wind-driven rain (WDR) experiments were conducted to evaluate interrill component of the Water Erosion Prediction Project (WEPP) model with two-dimensional experimental set-up in wind tunnel. Synchronized wind and rain simulations were applied to soil surfaces on windward and leeward slopes of 7, 15...

Controller design for a class of nonlinear MIMO coupled system using multiple models and second level adaptation.

PubMed

Pandey, Vinay Kumar; Kar, Indrani; Mahanta, Chitralekha

2017-07-01

In this paper, an adaptive control method using multiple models with second level adaptation is proposed for a class of nonlinear multi-input multi-output (MIMO) coupled systems. Multiple estimation models are used to tune the unknown parameters at the first level. The second level adaptation provides a single parameter vector for the controller. A feedback linearization technique is used to design a state feedback control. The efficacy of the designed controller is validated by conducting real time experiment on a laboratory setup of twin rotor MIMO system (TRMS). The TRMS setup is discussed in detail and the experiments were performed for regulation and tracking problem for pitch and yaw control using different reference signals. An Extended Kalman Filter (EKF) has been used to observe the unavailable states of the TRMS. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Validation of the Lanzarote Tide Gauges system designed at the Royal Observatory of Belgium

NASA Astrophysics Data System (ADS)

van Ruymbeke, Michel; Dumont, Philippe; Seknik, Matej

2017-04-01

A series of tide gauges was set-up in a very favorable site located inside a lava tube plunging in the Atlantic ocean. The damping of waves motion is dramaticaly large, allowing to observe very tight modulations of the sea level. The gauges are based on the EDAS interface connected to a capacitor variying with the level of the sea . Filtering is gained by counting of frequency modulated signal during a one minute interval The scale factor is defined by comparizon of the output signals of sensors and reading the water level at different time. We evaluate the performance of our design by analysing the long series of records at disposal. The analysis is based on a stacking approach to extract components for periodicities existing in the spectrum of sea tides . Concordance of the results between the three gauges recording simultaneously the same signal confirms applicability of our design in such environment. After de-tiding application, the residuals signals are correlated to various physical parameters which could contribute to the understanding of the involved geophysical process.

Measurement of SO2 and SO3 using a tunable diode laser system

NASA Astrophysics Data System (ADS)

Berkoff, Timothy A.; Wormhoudt, Joda C.; Miake-Lye, R. C.

1999-02-01

We describe the set-up and operation of a mid-infrared (lead- salt) tunable diode laser system used to measure SO2 and SO3 levels in the exhaust plume of an aircraft engine in an altitude test chamber. These measurements were part of an on-going effort to determine the sulfur emission and conversion of SO2 to SO3 in a representative exhaust under different altitudes, power conditions, and fuel sulfur loadings. Results obtained using this set-up demonstrate the ability to measure SO2 concentrations in the low ppmv range and the possibility of detecting SO3 when it is present at similar levels.

Percentage depth dose calculation accuracy of model based algorithms in high energy photon small fields through heterogeneous media and comparison with plastic scintillator dosimetry.

PubMed

Alagar, Ananda Giri Babu; Mani, Ganesh Kadirampatti; Karunakaran, Kaviarasu

2016-01-08

Small fields smaller than 4 × 4 cm2 are used in stereotactic and conformal treatments where heterogeneity is normally present. Since dose calculation accuracy in both small fields and heterogeneity often involves more discrepancy, algorithms used by treatment planning systems (TPS) should be evaluated for achieving better treatment results. This report aims at evaluating accuracy of four model-based algorithms, X-ray Voxel Monte Carlo (XVMC) from Monaco, Superposition (SP) from CMS-Xio, AcurosXB (AXB) and analytical anisotropic algorithm (AAA) from Eclipse are tested against the measurement. Measurements are done using Exradin W1 plastic scintillator in Solid Water phantom with heterogeneities like air, lung, bone, and aluminum, irradiated with 6 and 15 MV photons of square field size ranging from 1 to 4 cm2. Each heterogeneity is introduced individually at two different depths from depth-of-dose maximum (Dmax), one setup being nearer and another farther from the Dmax. The central axis percentage depth-dose (CADD) curve for each setup is measured separately and compared with the TPS algorithm calculated for the same setup. The percentage normalized root mean squared deviation (%NRMSD) is calculated, which represents the whole CADD curve's deviation against the measured. It is found that for air and lung heterogeneity, for both 6 and 15 MV, all algorithms show maximum deviation for field size 1 × 1 cm2 and gradually reduce when field size increases, except for AAA. For aluminum and bone, all algorithms' deviations are less for 15 MV irrespective of setup. In all heterogeneity setups, 1 × 1 cm2 field showed maximum deviation, except in 6MV bone setup. All algorithms in the study, irrespective of energy and field size, when any heterogeneity is nearer to Dmax, the dose deviation is higher compared to the same heterogeneity far from the Dmax. Also, all algorithms show maximum deviation in lower-density materials compared to high-density materials.

Acclimation of bloom-forming and perennial seaweeds to elevated pCO2 conserved across levels of environmental complexity.

PubMed

Xu, Dong; Schaum, Charlotte-Elisa; Lin, Fan; Sun, Ke; Munroe, James R; Zhang, Xiao W; Fan, Xiao; Teng, Lin H; Wang, Yi T; Zhuang, Zhi M; Ye, Naihao

2017-11-01

Macroalgae contribute approximately 15% of the primary productivity in coastal marine ecosystems, fix up to 27.4 Tg of carbon per year, and provide important structural components for life in coastal waters. Despite this ecological and commercial importance, direct measurements and comparisons of the short-term responses to elevated pCO 2 in seaweeds with different life-history strategies are scarce. Here, we cultured several seaweed species (bloom forming/nonbloom forming/perennial/annual) in the laboratory, in tanks in an indoor mesocosm facility, and in coastal mesocosms under pCO 2 levels ranging from 400 to 2,000 μatm. We find that, across all scales of the experimental setup, ephemeral species of the genus Ulva increase their photosynthesis and growth rates in response to elevated pCO 2 the most, whereas longer-lived perennial species show a smaller increase or a decrease. These differences in short-term growth and photosynthesis rates are likely to give bloom-forming green seaweeds a competitive advantage in mixed communities, and our results thus suggest that coastal seaweed assemblages in eutrophic waters may undergo an initial shift toward communities dominated by bloom-forming, short-lived seaweeds. © 2017 John Wiley & Sons Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bahena, A.; Villasenor, L.

We describe a simple experimental setup to measure the rate of arrival of muons at the surface of the Earth by using a single water Cerenkov detector and home-made electronics. We find a strong anti-correlation between the muon rates averaged over one-hour periods and the atmospheric pressure, with a measured correlation coefficient of -0.67% per hPa. After applying this correction we achieve sufficient sensitivity to observe long term (hours) variations in the averaged muon rates which are greater than 2%. Forbush decreases as big as 4% have been observed with muon detectors located at similar magnetic rigidities compared to Morelia,more » therefore our experimental setup will detect Forbush decreases as soon as the Sun enters into a more active phase.« less

UV-vis Imaging of Piroxicam Supersaturation, Precipitation, and Dissolution in a Flow-Through Setup.

PubMed

Sun, Yu; Chapman, Alex; Larsen, Susan W; Jensen, Henrik; Petersen, Nickolaj J; Goodall, David M; Østergaard, Jesper

2018-06-05

Evaluation of drug precipitation is important in order to address challenges regarding low and variable bioavailability of poorly water-soluble drugs, to assess potential risk of patient safety with infusion therapy, and to explore injectable in situ suspension-forming drug delivery systems. Generally, drug precipitation is assessed in vitro through solution concentration analysis methods. Dual-wavelength UV-vis imaging is a novel imaging technique that may provide an opportunity for simultaneously monitoring changes in both solution and solid phases during precipitation. In the present study, a multimodal approach integrating UV-vis imaging, light microscopy, and Raman spectroscopy was developed for characterization of piroxicam supersaturation, precipitation, and dissolution in a flow-through setup. A solution of piroxicam dissolved in 1-methyl-2-pyrrolidinone was injected into a flowing aqueous environment (pH 7.4), causing piroxicam to precipitate. Imaging at 405 and 280 nm monitored piroxicam concentration distributions during precipitation and revealed different supersaturation levels dependent on the initial concentration of the piroxicam solution. The combination with imaging at 525 nm, light microscopy, and Raman spectroscopy measurements demonstrated concentration-dependent precipitation and the formation, growth, and dissolution of individual particles. Results emphasize the importance of the specific hydrodynamic conditions on the piroxicam precipitation. The approach used may facilitate comprehensive understanding of drug precipitation and dissolution processes and may be developed further into a basic tool for formulation screening and development.

A catheter friction tester using balance sensor: Combined evaluation of the effects of mechanical properties of tubing materials and surface coatings.

PubMed

Røn, Troels; Jacobsen, Kristina Pilgaard; Lee, Seunghwan

2018-04-24

In this study, we introduce a new experimental approach to characterize the forces emerging from simulated catherization. This setup allows for a linear translation of urinary catheters in vertical direction as controlled by an actuator. By employing silicone-based elastomer with a duct of comparable diameter with catheters as urethra model, sliding contacts during the translation of catheters along the duct is generated. A most unique design and operation feature of this setup is that a digital balance was employed as the sensor to detect emerging forces from simulated catherization. Moreover, the possibility to give a variation in environment (ambient air vs. water), clearance, elasticity, and curvature of silicone-based urethra model allows for the detection of forces arising from diverse simulated catherization conditions. Two types of commercially available catheters varying in tubing materials and surface coatings were tested together with their respective uncoated catheter tubing. The first set of testing on the catheter samples showed that this setup can probe the combined effect from flexural strain of bulk tubing materials and slipperiness of surface coatings, both of which are expected to affect the comfort and smooth gliding in clinical catherization. We argue that this new experimental setup can provide unique and valuable information in preclinical friction testing of urinary catheters. Copyright © 2018 Elsevier Ltd. All rights reserved.

Single-photon interference experiment for high schools

NASA Astrophysics Data System (ADS)

Bondani, Maria

2014-07-01

We follow the reductio ad absurdum reasoning described in the book "Sneaking a Look at God's Cards" by Giancarlo Ghirardi to demonstrate the wave-particle duality of light in a Mach-Zehnder interferometric setup analog to the conventional Young double-slit experiment. We aim at showing the double nature of light by measuring the existence of interference fringes down to the single-photon level. The setup includes a strongly attenuated laser, polarizing beam splitters, half-waveplates, polarizers and single-photon detectors.

Integration of Grid and Local Batch Resources at DESY

NASA Astrophysics Data System (ADS)

Beyer, Christoph; Finnern, Thomas; Gellrich, Andreas; Hartmann, Thomas; Kemp, Yves; Lewendel, Birgit

2017-10-01

As one of the largest resource centres DESY has to support differing work flows of users from various scientific backgrounds. Users can be for one HEP experiments in WLCG or Belle II as well as local HEP users but also physicists from other fields as photon science or accelerator development. By abandoning specific worker node setups in favour of generic flat nodes with middleware resources provided via CVMFS, we gain flexibility to subsume different use cases in a homogeneous environment. Grid jobs and the local batch system are managed in a HTCondor based setup, accepting pilot, user and containerized jobs. The unified setup allows dynamic re-assignment of resources between the different use cases. Monitoring is implemented on global batch system metrics as well as on a per job level utilizing corresponding cgroup information.

Investigation of Coastal CDOM Distributions Using In-Situ and Remote Sensing Observations and a Predictive CDOM Fate and Transport Model

DTIC Science & Technology

2009-01-01

complementary description of CDOM photodegradation and, importantly, CDOM biomass and light absorption. As part of this work, we setup and run the new high...related loss terms from the ECOSIM 2.0 formulation (Bissett 2005 and FERI 2004) and included diffuse light attenuation in the water column based on...Huang, pers. comm.), c) we improved the photolysis rate equations and included light attenuation in the water column, and d) we expanded the limited

Setup in the Surfzone

DTIC Science & Technology

2007-09-01

broken wave would recover if it were to propagate in a constant water depth and ,b=Hbreak/ Hrms . The height of wave breaking Hbr ak is found from a...varies slightly for individual data records, the histograms of best-fit y are not significantly different for any of the error metrics (Figure 2- 4C ...i.e., for Hrm ,,o> 2 in), ij will become more important to the local water depth for h < I m. 3.4.2 Additional Terms 3.4.2.1 Summary Including bottom

Technologies for Humans in Space with Terrestrial Application for Testing in :envihab

NASA Astrophysics Data System (ADS)

Belz, Stefan; Henn, Norbert

Technologies for humans in space and for a sustainable resource management on Earth are faced to similar recycling challenges. The main differences between life support systems (LSS) in human spaceflight and Earth’s environment are the buffer capacities and enormous diversity of material and organisms in Earth. Thus, LSS in space as a small-scale set-up show quickly the problems of artificial cycle management. Such a cycle management becomes more and more important with increase on world’s population and enlargement of (mega-)cities, in order to provide clean air, clean water and no wasting the environment. There is a need of technologies on Earth and for crewed long-term missions in space focusing on efficient and clean electricity generation, as well as on air, water, food, and waste management at lowest power demand. Existing technologies shall be adapted, and new technologies shall be developed for enhancing quality of life on Earth. The poster demonstrates some significant activities in Germany in the field of air revitalization, biomass and food production by microalgae cultivation, biological water regeneration, synergetic use of fuel cells and electrolyzers, respectively hydrogen and oxygen, in life support and energy systems. These technologies make a strong contribution to higher cycle closures, especially combined in an overall system configuration. The facility of :envihab (Environment and Habitat) in Cologne/Germany enables a unique testbed for integrative experiments from component level to system level, in order to demonstrate and investigate compatibilities, required peripherals devices and diagnostic tools.

Sequential UV- and chlorine-based disinfection to mitigate Escherichia coli in drinking water biofilms.

PubMed

Murphy, H M; Payne, S J; Gagnon, G A

2008-04-01

This study was designed to examine the potential downstream benefits of sequential disinfection to control the persistence of Escherichia coli under conditions relevant to drinking water distribution systems. Eight annular reactors (four polycarbonate and four cast iron) were setup in parallel to address various factors that could influence biofilm growth in distribution systems. Eight reactors were treated with chlorine, chlorine dioxide and monochloramine alone or in combination with UV to examine the effects on Escherichia coli growth and persistence in both the effluent and biofilm. In general, UV-treated systems in combination with chlorine or chlorine dioxide and monochloramine achieved greater log reductions in both effluent and biofilm than systems treated with chlorine-based disinfectants alone. However, during UV-low chlorine disinfection, E. coli was found to persist at low levels, suggesting that the UV treatment had instigated an adaptive mutation. During UV-chlorine-dioxide treatment, the E. coli that was initially below the detection limit reappeared during a low level of disinfection (0.2 mg/L) in the cast iron systems. Chloramine was shown to be effective in disinfecting suspended E. coli in the effluent but was unable to reduce biofilm counts to below the detection limit. Issues such as repair mechanism of E. coli and nitrification could help explain some of these aberrations. Improved understanding of the ability of chlorine-based disinfectant in combination with UV to provide sufficient disinfection will ultimately effect in improved management and safety of drinking water.

fMRI brain mapping during motion capture and FES induced motor tasks: signal to noise ratio assessment.

PubMed

Gandolla, Marta; Ferrante, Simona; Casellato, Claudia; Ferrigno, Giancarlo; Molteni, Franco; Martegani, Alberto; Frattini, Tiziano; Pedrocchi, Alessandra

2011-10-01

Functional Electrical Stimulation (FES) is a well known clinical rehabilitation procedure, however the neural mechanisms that underlie this treatment at Central Nervous System (CNS) level are still not completely understood. Functional magnetic resonance imaging (fMRI) is a suitable tool to investigate effects of rehabilitative treatments on brain plasticity. Moreover, monitoring the effective executed movement is needed to correctly interpret activation maps, most of all in neurological patients where required motor tasks could be only partially accomplished. The proposed experimental set-up includes a 1.5 T fMRI scanner, a motion capture system to acquire kinematic data, and an electro-stimulation device. The introduction of metallic devices and of stimulation current in the MRI room could affect fMRI acquisitions so as to prevent a reliable activation maps analysis. What we are interested in is that the Blood Oxygenation Level Dependent (BOLD) signal, marker of neural activity, could be detected within a given experimental condition and set-up. In this paper we assess temporal Signal to Noise Ratio (SNR) as image quality index. BOLD signal change is about 1-2% as revealed by a 1.5 T scanner. This work demonstrates that, with this innovative set-up, in the main cortical sensorimotor regions 1% BOLD signal change can be detected at least in the 93% of the sub-volumes, and almost 100% of the sub-volumes are suitable for 2% signal change detection. The integrated experimental set-up will therefore allows to detect FES induced movements fMRI maps simultaneously with kinematic acquisitions so as to investigate FES-based rehabilitation treatments contribution at CNS level. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

Nutrient changes and biodynamics of Eisenia fetida during vermicomposting of water lettuce (Pistia sp.) biomass: a noxious weed of aquatic system.

PubMed

Suthar, Surindra; Pandey, Bhawna; Gusain, Rita; Gaur, Rubia Zahid; Kumar, Kapil

2017-01-01

This paper reports the results of vermicomposting of water lettuce biomass (WL) spiked with cow dung at ratios of 20, 40, 60, and 80 % employing Eisenia fetida. A total of four treatments were established and changes in chemical properties of mixtures were observed. Vermicomposting caused a decrease in pH, TOC, volatile solids, and C/N ratio by 1.01-1.08-fold, 0.85-0.92-fold, 0.94-0.96-fold, 0.56-0.70-fold, respectively, but increase in EC, tot N, tot P, tot K, tot Ca, tot Zn, tot Fe, and tot Cu, by 1.19-1.42-fold, 1.33-1.68-fold, 1.38-1.69-fold, 1.13-1.24-fold, 1.04-1.11-fold, 1.16-1.37-fold, 1.05-1.113-fold, 1.10-1.27-fold, respectively. Overall, the treatment with 60-80 % of WL showed the maximum decomposition and mineralization rates. The earthworm showed the growth and reproduction rate in considerable ranges in all treatment setups but setups with 60-80 % WL proportion exhibited the optimum results. Results reveal that biomass of water lettuce can be utilized effectively for production of valuable manure through vermicomposting system.

Hydrostatic Water Level Systems At Homestake DUSEL

NASA Astrophysics Data System (ADS)

Stetler, L. D.; Volk, J. T.

2009-12-01

Two arrays of Fermilab-style hydrostatic water level sensors have been installed in the former Homestake gold mine in Lead, SD, the site of the new Deep Underground Science and Engineering Laboratory (DUSEL). Sensors were constructed at Fermilab from 8.5 cm diameter PVC pipe (housing) that was sealed on the ends and fit with a proximity sensor. The instrument have a height of 10 cm. Two ports in each sensor housing provide for connectivity, the upper port for air and the bottom port for water. Multiple instruments connected in series provide a precise water level and differences in readings between successive sensors provide for ground tilt to be resolved. Sensor resolution is 5 μm per count and has a range of approximately 1.25 cm. Data output from each sensor is relayed to a Fermilab-constructed readout card that also has temperature/relative humidity and barometric pressure sensors connected. All data are relayed out of the mine by fiber optic cable and can be recorded by Ethernet at remote locations. The current arrays have been installed on the 2000-ft level (610 m) and consist of six instruments in each array. Three sensors were placed in a N-S oriented drift and three in an E-W oriented drift. Using this orientation, it is anticipated that tilt direction may be resolved in addition to overall tilt magnitude. To date the data show passage of earth tides and frequency analysis has revealed five components to this signal, three associated with the semi-diurnal (~12.4 hr) and two with the diurnal (~24.9 hr) tides. Currently, installation methods are being analyzed between concrete pillar and rib-mounting using the existing setup on the 2000-ft level. Using these results, two additional arrays of Fermilab instruments will be installed on the 4550-ft and 4850-ft levels (1387 and 1478 m, respectively). In addition to Fermilab instruments, several high resolution Budker tiltmeters (1 μm resolution) will be installed in the mine workings in the near future, some correlated to Fermilab instruments (for comparative analysis) and others in independent arrays. All tiltmeter data will be analyzed with water reduction data (currently being collected from the #6 winze as the mine is dewatered) and data from rock stress/fracture experiments to document net ground settling due to dewatering, potential collapse of stope areas and renewed excavation activities.

U.S. Naval Research Laboratory Final Analysis Report to NATO Above Water Warfare Capabilities Group 2016 Naval Electromagnetic Operations Trials

DTIC Science & Technology

2017-05-23

Systems and the NRL Code 5763 Radio Frequency (RF) Stimulator. It includes and covers system descriptions , setup, data collection, and test goals that...6 4. Test Asset Descriptions ...7 4.1. Description of FOXTROT Anti-ship Missile (ASM) Simulator ......................................... 7

Variable Temperature Equipment for a Commercial Magnetic Susceptibility Balance

ERIC Educational Resources Information Center

Lotz, Albert

2008-01-01

Variable temperature equipment for the magnetic susceptibility balance MSB-MK1 of Sherwood Scientific, Ltd., is described. The sample temperature is controlled with streaming air heated by water in a heat exchanger. Whereas the balance as sold commercially can be used only for room temperature measurements, the setup we designed extends the…

Laboratory Evaluation of EGS Shear Stimulation-Test 001

DOE Data Explorer

Bauer, Steve

2014-07-29

this is the results of an initial setup-shakedon test in order to develop the plumbing system for this test design. a cylinder of granite with offset holes was jacketed and subjected to confining pressure and low temperature (85C) and pore water pressure. flow through the sample was developed at different test stages.

Optimization of the cleaning process on a pilot filtration setup for waste water treatment accompanied by flow visualization

NASA Astrophysics Data System (ADS)

Bílek, Petr; Hrůza, Jakub

2018-06-01

This paper deals with an optimization of the cleaning process on a liquid flat-sheet filter accompanied by visualization of the inlet side of a filter. The cleaning process has a crucial impact on the hydrodynamic properties of flat-sheet filters. Cleaning methods avoid depositing of particles on the filter surface and forming a filtration cake. Visualization significantly helps to optimize the cleaning methods, because it brings new overall view on the filtration process in time. The optical method, described in the article, enables to see flow behaviour in a thin laser sheet on the inlet side of a tested filter during the cleaning process. Visualization is a strong tool for investigation of the processes on filters in details and it is also possible to determine concentration of particles after an image analysis. The impact of air flow rate, inverse pressure drop and duration on the cleaning mechanism is investigated in the article. Images of the cleaning process are compared to the hydrodynamic data. The tests are carried out on a pilot filtration setup for waste water treatment.

Factors controlling stream water nitrate and phosphor loads during precipitation events

NASA Astrophysics Data System (ADS)

Rozemeijer, J.; van der Velde, Y.; van Geer, F.; de Rooij, G. H.; Broers, H.; Bierkens, M. F.

2009-12-01

Pollution of surface waters in densely populated areas with intensive land use is a serious threat to their ecological, industrial and recreational utilization. European and national manure policies and several regional and local pilot projects aim at reducing pollution loads to surface waters. For the evaluation of measures, water authorities and environmental research institutes are putting a lot of effort into monitoring surface water quality. Within regional surface water quality monitoring networks, the measurement locations are usually situated in the downstream part of the catchment to represent a larger area. The monitoring frequency is usually low (e.g. monthly), due to the high costs for sampling and analysis. As a consequence, human induced trends in nutrient loads and concentrations in these monitoring data are often concealed by the large variability of surface water quality caused by meteorological variations. Because this natural variability in surface water quality is poorly understood, large uncertainties occur in the estimates of (trends in) nutrient loads or average concentrations. This study aims at uncertainty reduction in the estimates of mean concentrations and loads of N and P from regional monitoring data. For this purpose, we related continuous records of stream water N and P concentrations to easier and cheaper to collect quantitative data on precipitation, discharge, groundwater level and tube drain discharge. A specially designed multi scale experimental setup was installed in an agricultural lowland catchment in The Netherlands. At the catchment outlet, continuous measurements of water quality and discharge were performed from July 2007-January 2009. At an experimental field within the catchment we collected continuous measurements of precipitation, groundwater levels and tube drain discharges. 20 significant rainfall events with a variety of antecedent conditions, durations and intensities were selected for analysis. Singular and multiple regression analysis were used to identify relations between the N and P response to the rainfall events and the quantitative event characteristics. We successfully used these relations to predict the N and P responses to events and to improve the interpolation between low frequency grab sample measurements. Incorporating the predicted concentration changes during high discharge events dramatically improved the precision of our load estimations.

Stakeholder participation in the new water management approach: a case study of the Save catchment, Zimbabwe

NASA Astrophysics Data System (ADS)

Dube, Dumisani; Swatuk, Larry A.

The 1998 Zimbabwe Water Act introduced the ideas of 'lowest appropriate authority' in the management of water resources. To this end, the country has been divided into seven catchments. This new set-up is intended to achieve efficiency, accountability and sustainability through stakeholder participation. This paper critically examines the way in which the idea of 'stakeholder participation' has been operationalised in the new water reform process. We examine recent experiences of participation in the creation and operation of the new water management structure, in particular Catchment Councils in Zimbabwe, and argue against an uncritical or atheoretical understanding of 'participation'. To simply assume that inclusivist language translates into wider benefits for society is to ignore the profoundly political nature of the entire water reform process.

A novel water-assisted pulsed light processing for decontamination of blueberries.

PubMed

Huang, Yaoxin; Chen, Haiqiang

2014-06-01

Sample heating and shadowing effect have limited the application of pulsed light (PL) technology for decontamination of fresh produce. In this study, a novel setup using water-assisted PL processing was developed to overcome these limitations. Blueberries inoculated with Escherichia coli O157:H7 or Salmonella were either treated with PL directly (dry PL treatment) or immersed in agitated water during the PL treatment (wet PL treatment) for 5-60 s. Although both pathogens were effectively inactivated by the dry PL treatments, the appearance of the blueberries was adversely affected and a maximum temperature of 64.8 °C on the blueberry surface was recorded. On the other hand, the visual appearance of blueberries remained unchanged after wet PL treatments and sample heating was significantly reduced. The wet PL treatments were more effective than chlorine washing on inactivating both pathogens. After a 60-s wet PL treatment, the populations of E. coli O157:H7 inoculated on calyx and skin of blueberries were reduced by 3.0 and >5.8 log CFU/g, respectively. Salmonella on blueberry calyx and skin was reduced by 3.6 and >5.9 log CFU/g, respectively. No viable bacterial cells were recovered from the water used in the wet PL treatments, demonstrating that this setup could prevent the risk of cross-contamination during fresh produce washing. Our results suggest that this new water-assisted PL treatment could be a potential non-chemical alternative (residue free) to chlorine washing since it is both more effective and environmentally friendly than chlorine washing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterization of a multi-axis ion chamber array

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simon, Thomas A.; Kozelka, Jakub; Simon, William E.

Purpose: The aim of this work was to characterize a multi-axis ion chamber array (IC PROFILER; Sun Nuclear Corporation, Melbourne, FL USA) that has the potential to simplify the acquisition of LINAC beam data. Methods: The IC PROFILER (or panel) measurement response was characterized with respect to radiation beam properties, including dose, dose per pulse, pulse rate frequency (PRF), and energy. Panel properties were also studied, including detector-calibration stability, power-on time, backscatter dependence, and the panel's agreement with water tank measurements [profiles, fractional depth dose (FDD), and output factors]. Results: The panel's relative deviation was typically within ({+-}) 1% ofmore » an independent (or nominal) response for all properties that were tested. Notable results were (a) a detectable relative field shape change of {approx}1% with linear accelerator PRF changes; (b) a large range in backscatter thickness had a minimal effect on the measured dose distribution (typically less than 1%); (c) the error spread in profile comparison between the panel and scanning water tank (Blue Phantom, CC13; IBA Schwarzenbruck, DE) was approximately ({+-}) 0.75%. Conclusions: The ability of the panel to accurately reproduce water tank profiles, FDDs, and output factors is an indication of its abilities as a dosimetry system. The benefits of using the panel versus a scanning water tank are less setup time and less error susceptibility. The same measurements (including device setup and breakdown) for both systems took 180 min with the water tank versus 30 min with the panel. The time-savings increase as the measurement load is increased.« less

Polymer gel water equivalence and relative energy response with emphasis on low photon energy dosimetry in brachytherapy

NASA Astrophysics Data System (ADS)

Pantelis, E.; Karlis, A. K.; Kozicki, M.; Papagiannis, P.; Sakelliou, L.; Rosiak, J. M.

2004-08-01

The water equivalence and stable relative energy response of polymer gel dosimeters are usually taken for granted in the relatively high x-ray energy range of external beam radiotherapy based on qualitative indices such as mass and electron density and effective atomic number. However, these favourable dosimetric characteristics are questionable in the energy range of interest to brachytherapy especially in the case of lower energy photon sources such as 103Pd and 125I that are currently utilized. In this work, six representative polymer gel formulations as well as the most commonly used experimental set-up of a LiF TLD detector-solid water phantom are discussed on the basis of mass attenuation and energy absorption coefficients calculated in the energy range of 10 keV-10 MeV with regard to their water equivalence as a phantom and detector material. The discussion is also supported by Monte Carlo simulation results. It is found that water equivalence of polymer gel dosimeters is sustained for photon energies down to about 60 keV and no corrections are needed for polymer gel dosimetry of 169Yb or 192Ir sources. For 125I and 103Pd sources, however, a correction that is source-distance dependent is required. Appropriate Monte Carlo results show that at the dosimetric reference distance of 1 cm from a source, these corrections are of the order of 3% for 125I and 2% for 103Pd. These have to be compared with corresponding corrections of up to 35% for 125I and 103Pd and up to 15% even for the 169Yb energies for the experimental set-up of the LiF TLD detector-solid water phantom.

Polymer gel water equivalence and relative energy response with emphasis on low photon energy dosimetry in brachytherapy.

PubMed

Pantelis, E; Karlis, A K; Kozicki, M; Papagiannis, P; Sakelliou, L; Rosiak, J M

2004-08-07

The water equivalence and stable relative energy response of polymer gel dosimeters are usually taken for granted in the relatively high x-ray energy range of external beam radiotherapy based on qualitative indices such as mass and electron density and effective atomic number. However, these favourable dosimetric characteristics are questionable in the energy range of interest to brachytherapy especially in the case of lower energy photon sources such as 103Pd and 125I that are currently utilized. In this work, six representative polymer gel formulations as well as the most commonly used experimental set-up of a LiF TLD detector-solid water phantom are discussed on the basis of mass attenuation and energy absorption coefficients calculated in the energy range of 10 keV-10 MeV with regard to their water equivalence as a phantom and detector material. The discussion is also supported by Monte Carlo simulation results. It is found that water equivalence of polymer gel dosimeters is sustained for photon energies down to about 60 keV and no corrections are needed for polymer gel dosimetry of 169Yb or 192Ir sources. For 125I and 103Pd sources, however, a correction that is source-distance dependent is required. Appropriate Monte Carlo results show that at the dosimetric reference distance of 1 cm from a source, these corrections are of the order of 3% for 125I and 2% for 103Pd. These have to be compared with corresponding corrections of up to 35% for 125I and 103Pd and up to 15% even for the 169Yb energies for the experimental set-up of the LiF TLD detector-solid water phantom.

Offshore multiphase meter nears acceptable accuracy level

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaisford, S.; Amdal, J.; Berentsen, H.

1993-05-17

Companies worldwide are looking for new production methods for offshore oil fields. In many areas, undeveloped smaller fields cannot bear the cost of dedicated production facilities. Multiphase transportation to existing production facilities can extend the distance over which unseparated oil, water, and gas streams can be transported, from a limit of several kilometers today to perhaps 200 km in the future. An encouraging multiphase meter test was sponsored by Saga Petroleum AS and carried out by Den norske stats oljeselskap AS (Statoil) on the Gullfaks B platform, Norwegian sector of the North Sea. The complete multiphase meter has two separatemore » meters. One is the composition meter for measuring the instantaneous volume or mass fractions of oil, water, and gas in the sensor. The other is a velocity meter for determining the speed of the mixture through the sensor. An instantaneous volume or mass production rate for each component is calculated by combining the outputs from the two meters. The paper describes the multiphase meter; measurements; limitations; the test setup; calibration; test results for the composition meter, velocity meter, and production rates; and future plans.« less

Automation of sample processing for ICP-MS determination of 90Sr radionuclide at ppq level for nuclear technology and environmental purposes.

PubMed

Kołacińska, Kamila; Chajduk, Ewelina; Dudek, Jakub; Samczyński, Zbigniew; Łokas, Edyta; Bojanowska-Czajka, Anna; Trojanowicz, Marek

2017-07-01

90 Sr is a widely determined radionuclide for environmental purposes, nuclear waste control, and can be also monitored in coolants in nuclear reactor plants. In the developed method, the ICP-MS detection was employed together with sample processing in sequential injection analysis (SIA) setup, equipped with a lab-on-valve with mechanized renewal of sorbent bed for solid-phase extraction. The optimized conditions of determination included preconcentration of 90 Sr on cation-exchange column and removal of different type of interferences using extraction Sr-resin. The limit of detection of the developed procedure depends essentially on the configuration of the employed ICP-MS spectrometer and on the available volume of the sample to be analyzed. For 1L initial sample volume, the method detection limit (MDL) value was evaluated as 2.9ppq (14.5BqL -1 ). The developed method was applied to analyze spiked river water samples, water reference materials, and also simulated and real samples of the nuclear reactor coolant. Copyright © 2016 Elsevier B.V. All rights reserved.

Illustrating the quantum approach with an Earth magnetic field MRI

NASA Astrophysics Data System (ADS)

Pars Benli, Kami; Dillmann, Baudouin; Louelh, Ryma; Poirier-Quinot, Marie; Darrasse, Luc

2015-05-01

Teaching imaging of magnetic resonance (MR) today is still as challenging as it has always been, because it requires admitting that we cannot express fundamental questions of quantum mechanics with straightforward language or without using extensive theory. Here we allow students to face a real MR setup based on the Earth's magnetic field. We address the applied side of teaching MR using a device that is affordable and that proves to be sufficiently robust, at universities in Orsay, France, and San Sebastian, Spain, in experimental practicals at undergraduate and graduate levels. We specifically present some of the advantages of low field for measuring R2 relaxation rates, reaching a power of separation of 1.5 μmol on Mn(II) ions between two water bottles each of half a liter. Finally we propose key approaches for the lecturers to adopt when they are asked to pass from theoretical knowledge to teachable knowhow. The outcomes are fast calibration and the MR acquisition protocols, demonstrating the reproducibility of energy transfer during the saturation pulses, and the quantitative nature of MR, with water protons and a helium-3 sample.

HIGH POWER BEAM DUMP AND TARGET / ACCELERATOR INTERFACE PROCEDURES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blokland, Willem; Plum, Michael A; Peters, Charles C

Satisfying operational procedures and limits for the beam target interface is a critical concern for high power operation at spallation neutron sources. At the Oak Ridge Spallation Neutron Source (SNS) a number of protective measures are instituted to ensure that the beam position, beam size and peak intensity are within acceptable limits at the target and high power Ring Injection Dump (RID). The high power beam dump typically handles up to 50 100 kW of beam power and its setup is complicated by the fact that there are two separate beam components simultaneously directed to the dump. The beam onmore » target is typically in the 800-1000 kW average power level, delivered in sub- s 60 Hz pulses. Setup techniques using beam measurements to quantify the beam parameters at the target and dump will be described. However, not all the instrumentation used for the setup and initial qualification is available during high power operation. Additional techniques are used to monitor the beam during high power operation to ensure the setup conditions are maintained, and these are also described.« less

Dielectric relaxation measurement and analysis of restricted water structure in rice kernels

NASA Astrophysics Data System (ADS)

Yagihara, Shin; Oyama, Mikio; Inoue, Akio; Asano, Megumi; Sudo, Seiichi; Shinyashiki, Naoki

2007-04-01

Dielectric relaxation measurements were performed for rice kernels by time domain reflectometry (TDR) with flat-end coaxial electrodes. Difficulties in good contact between the surfaces of the electrodes and the kernels are eliminated by a TDR set-up with a sample holder for a kernel, and the water content could be evaluated from relaxation curves. Dielectric measurements were performed for rice kernels, rice flour and boiled rice with various water contents, and the water amount and dynamic behaviour of water molecules were explained from restricted dynamics of water molecules and also from the τ-β (relaxation time versus the relaxation-time distribution parameter of the Cole-Cole equation) diagram. In comparison with other aqueous systems, the dynamic structure of water in moist rice is more similar to aqueous dispersion systems than to aqueous solutions.

New optical scheme for a polarimetric-based glucose sensor

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Bockle, Stefan; Rovati, Luigi

2004-01-01

A new optical scheme to detect glucose concentration in the aqueous humor of the eye is presented. The ultimate aim is to apply this technique in designing a new instrument for, routinely and frequently, noninvasively monitoring blood glucose levels in diabetic patients without contact (no index matching) between the eye and the instrument. The optical scheme exploits the Brewster reflection of circularly polarized light off of the lens of the eye. Theoretically, this reflected linearly polarized light on its way to the detector is expected to rotate its state of polarization, owing to the presence of glucose molecules in the aqueous humor of a patient's eye. An experimental laboratory setup based on this scheme was designed and tested by measuring a range of known concentrations of glucose solutions dissolved in water. (c) 2004 Society of Photo-Optical Instrumentation Engineers.

Efficient bone cutting with the novel diode pumped Er:YAG laser system: in vitro investigation and optimization of the treatment parameters

NASA Astrophysics Data System (ADS)

Stock, Karl; Diebolder, Rolf; Hausladen, Florian; Hibst, Raimund

2014-03-01

It is well known that flashlamp pumped Er:YAG lasers allow efficient bone ablation due to strong absorption at 3μm by water. Preliminary experiments revealed also a newly developed diode pumped Er:YAG laser system (Pantec Engineering AG) to be an efficient tool for use for bone surgery. The aim of the present in vitro study is the investigation of a new power increased version of the laser system with higher pulse energy and optimization of the treatment set-up to get high cutting quality, efficiency, and ablation depth. Optical simulations were performed to achieve various focus diameters and homogeneous beam profile. An appropriate experimental set-up with two different focusing units, a computer controlled linear stage with sample holder, and a shutter unit was realized. By this we are able to move the sample (slices of pig bone) with a defined velocity during the irradiation. Cutting was performed under appropriate water spray by moving the sample back and forth. After each path the ablation depth was measured and the focal plane was tracked to the actual bottom of the groove. Finally, the cuts were analyzed by light microcopy regarding the ablation quality and geometry, and thermal effects. In summary, the results show that with carefully adapted irradiation parameters narrow and deep cuts (ablation depth > 6mm, aspect ratio approx. 20) are possible without carbonization. In conclusion, these in vitro investigations demonstrate that high efficient bone cutting is possible with the diode pumped Er:YAG laser system using appropriate treatment set-up and parameters.

SU-E-T-282: Dose Measurements with An End-To-End Audit Phantom for Stereotactic Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, R; Artschan, R; Thwaites, D

Purpose: Report on dose measurements as part of an end-to-end test for stereotactic radiotherapy, using a new audit tool, which allows audits to be performed efficiently either by an onsite team or as a postal audit. Methods: Film measurements have been performed with a new Stereotactic Cube Phantom. The phantom has been designed to perform Winston Lutz type position verification measurements and dose measurements in one setup. It comprises a plastic cube with a high density ball in its centre (used for MV imaging with film or EPID) and low density markers in the periphery (used for Cone Beam Computedmore » Tomography, CBCT imaging). It also features strategically placed gold markers near the posterior and right surfaces, which can be used to calculate phantom rotations on MV images. Slit-like openings allow insertion of film or other detectors.The phantom was scanned and small field treatment plans were created. The fields do not traverse any inhomogeneities of the phantom on their paths to the measurement location. The phantom was setup at the delivery system using CBCT imaging. The calculated treatment fields were delivered, each with a piece of radiochromic film (EBT3) placed in the anterior film holder of the phantom. MU had been selected in planning to achieve similar exposures on all films. Calibration films were exposed in solid water for dose levels around the expected doses. Films were scanned and analysed following established procedures. Results: Setup of the cube showed excellent suitability for CBCT 3D alignment. MV imaging with EPID allowed for clear identification of all markers. Film based dose measurements showed good agreement for MLC created fields down to 0.5 mm × 0.5 mm. Conclusion: An end-to-end audit phantom for stereotactic radiotherapy has been developed and tested.« less

Detecting technology of biophotons

NASA Astrophysics Data System (ADS)

Ma, Junfu; Zhu, Zhaohui; Zhu, Yanbin

2002-03-01

A key technique of detecting the ultra-weak photon emission from biological system (UPE) is to change the light signal of an extremely weak level into electric signal of a considerable level when the photo-electric detecting system were be applied. This paper analyzed the difficult for detecting the ultra-weak photon emission from biological system (UPE) mainly is in the absence of high sensitivity detector in UV-visible-infra spectra region. An experimental setup for testing UPE in different spectral region was designed. Using the experimental setup the test data of different several spectral regions from 300 nm to 1060 nm has were tested. The test result show the UPE of living biological system exists in wide spectra region from UV- visible to infrared.

Forced Convective Heat Transfer of Aqueous Al₂O₃ Nanofluid Through Shell and Tube Heat Exchanger.

PubMed

Haque, A K M Mahmudul; Kim, Sedong; Kim, Junhyo; Noh, Jungpil; Huh, Sunchul; Choi, Byeongkeun; Chung, Hanshik; Jeong, Hyomin

2018-03-01

This study presents the forced convective heat transfer of a nanofluid consisting of distilled water and different weight concentrations (1 wt% and 2 wt%) of Al2O3 nanoparticles flowing in a vertical shell and tube heat exchanger under counter flow and laminar flow regime with certain constant heat flaxes (at 20 °C, 30 °C, 40 °C and 50 °C). The Al2O3 nanoparticles of about 50 nm diameter are used in the present study. Stability of aqueous Al2O3 nanofluids, TEM, thermal conductivity, temperature differences, heat transfer rate, T-Q diagrams, LMTD and convective heat transfer coefficient are investigated experimentally. Experimental results emphasize the substantial enhancement of heat transfer due to the Al2O3 nanoparticles presence in the nanofluid. Heat transfer rate for distilled water and aqueous nanofluids are calculated after getting an efficient setup which shows 19.25% and 35.82% enhancement of heat transfer rate of 1 wt% and 2 wt% aqueous Al2O3 nanofluids as compared to that of distilled water. Finally, the analysis shows that though there are 27.33% and 59.08% enhancement of 1 wt% Al2O3 and 2 wt% Al2O3 respectively as compared to that of distilled water at 30 °C, convective heat transfer coefficient decreases with increasing heat flux of heated fluid in this experimental setup.

Absorption spectroscopy setup for determination of whole human blood and blood-derived materials spectral characteristics

NASA Astrophysics Data System (ADS)

Wróbel, M. S.; Gnyba, M.; Milewska, D.; Mitura, K.; Karpienko, K.

2015-09-01

A dedicated absorption spectroscopy system was set up using tungsten-halogen broadband source, optical fibers, sample holder, and a commercial spectrometer with CCD array. Analysis of noise present in the setup was carried out. Data processing was applied to the absorption spectra to reduce spectral noise, and improve the quality of the spectra and to remove the baseline level. The absorption spectra were measured for whole blood samples, separated components: plasma, saline, washed erythrocytes in saline and human whole blood with biomarkers - biocompatible nanodiamonds (ND). Blood samples had been derived from a number of healthy donors. The results prove a correct setup arrangement, with adequate preprocessing of the data. The results of blood-ND mixtures measurements show no toxic effect on blood cells, which proves the NDs as a potential biocompatible biomarkers.

High Energy Rate Forming Induced Phase Transition in Austenitic Steel

NASA Astrophysics Data System (ADS)

Kovacs, T.; Kuzsella, L.

2017-02-01

In this study, the effects of explosion hardening on the microstructure and the hardness of austenitic stainless steel have been studied. The optimum explosion hardening technology of austenitic stainless steel was researched. In case of the explosive hardening used new idea means indirect hardening setup. Austenitic stainless steels have high plasticity and can be cold formed easily. However, during cold processing the hardening phenomena always occurs. Upon the explosion impact, the deformation mechanism indicates a plastic deformation and this deformation induces a phase transformation (martensite). The explosion hardening enhances the mechanical properties of the material, includes the wear resistance and hardness [1]. In case of indirect hardening as function of the setup parameters specifically the flayer plate position the hardening increased differently. It was find a relationship between the explosion hardening setup and the hardening level.

Degradation of partially immersed glass: A new perspective

NASA Astrophysics Data System (ADS)

Chinnam, R. K.; Fossati, P. C. M.; Lee, W. E.

2018-05-01

The International Simple Glass (ISG) is a six-component borosilicate glass which was developed as a reference for international collaborative studies on high level nuclear waste encapsulation. Its corrosion behaviour is typically examined when it is immersed in a leaching solution, or when it is exposed to water vapour. In this study, an alternative situation is considered in which the glass is only partially immersed for 7 weeks at a temperature of 90 °C. In this case, half of the glass sample is directly in the solution itself, and the other half is in contact with a water film formed by condensation of water vapour that evaporated from the solution. This results in a different degradation behaviour compared to standard tests in which the material is fully immersed. In particular, whilst in standard tests the system reaches a steady state with a very low alteration rate thanks to the formation of a protective gel layer, in partially-immersed tests this steady state could not be reached because of the continuous alteration from the condensate water film. The constant input of ions from the emerged part of the sample caused a supersaturation of the solution, which resulted in early precipitation of secondary crystalline phases. This setup mimics storage conditions once small amounts of water have entered a glass waste form containing canister. It offers a more realistic outlook of corrosion mechanisms happening in such situations than standard fully-immersed corrosion tests.

Calibration and use of continuous heat-type automated seepage meters for submarine groundwater discharge measurements

USGS Publications Warehouse

Mwashote, B.M.; Burnett, W.C.; Chanton, J.; Santos, I.R.; Dimova, N.; Swarzenski, P.W.

2010-01-01

Submarine groundwater discharge (SGD) assessments were conducted both in the laboratory and at a field site in the northeastern Gulf of Mexico, using a continuous heat-type automated seepage meter (seepmeter). The functioning of the seepmeter is based on measurements of a temperature gradient in the water between downstream and upstream positions in its flow pipe. The device has the potential of providing long-term, high-resolution measurements of SGD. Using a simple inexpensive laboratory set-up, we have shown that connecting an extension cable to the seepmeter has a negligible effect on its measuring capability. Similarly, the observed influence of very low temperature (???3 ??C) on seepmeter measurements can be accounted for by conducting calibrations at such temperatures prior to field deployments. Compared to manual volumetric measurements, calibration experiments showed that at higher water flow rates (>28 cm day-1 or cm3 cm-2 day-1) an analog flowmeter overestimated flow rates by ???7%. This was apparently due to flow resistance, turbulence and formation of air bubbles in the seepmeter water flow tubes. Salinity had no significant effect on the performance of the seepmeter. Calibration results from fresh water and sea water showed close agreement at a 95% confidence level significance between the data sets from the two media (R2 = 0.98). Comparatively, the seepmeter SGD measurements provided data that are comparable to manually-operated seepage meters, the radon geochemical tracer approach, and an electromagnetic (EM) seepage meter. ?? 2009 Elsevier Ltd.

Real-time hydrological early warning system at national scale for surface water and groundwater with stakeholder involvement

NASA Astrophysics Data System (ADS)

He, X.; Stisen, S.; Henriksen, H. J.

2015-12-01

Hydrological models are important tools to support decision making in water resource management in the past few decades. Nowadays, frequent occurrence of extreme hydrological events has put focus on development of real-time hydrological modeling and forecasting systems. Among the various types of hydrological models, it is only the rainfall-runoff models for surface water that are commonly used in the online real-time fashion; and there is never a tradition to use integrated hydrological models for both surface water and groundwater with large scale perspective. At the Geological Survey of Denmark and Greenland (GEUS), we have setup and calibrated an integrated hydrological model that covers the entire nation, namely the DK-model. So far, the DK-model has only been used in offline mode for historical and future scenario simulations. Therefore, challenges arise when operating the DK-model in real-time mode due to lack of technical experiences and stakeholder awareness. In the present study, we try to demonstrate the process of bringing the DK-model online while actively involving the opinions of the stakeholders. Although the system is not yet fully operational, a prototype has been finished and presented to the stakeholders which can simulate groundwater levels, streamflow and water content in the root zone with a lead time of 48 hours and refreshed every 6 hours. The active involvement of stakeholders has provided very valuable insights and feedbacks for future improvements.

Experimental investigation of the flow dynamics and rheology of complex fluids in pipe flow by hybrid multi-scale velocimetry

NASA Astrophysics Data System (ADS)

Haavisto, Sanna; Cardona, Maria J.; Salmela, Juha; Powell, Robert L.; McCarthy, Michael J.; Kataja, Markku; Koponen, Antti I.

2017-11-01

A hybrid multi-scale velocimetry method utilizing Doppler optical coherence tomography in combination with either magnetic resonance imaging or ultrasound velocity profiling is used to investigate pipe flow of four rheologically different working fluids under varying flow regimes. These fluids include water, an aqueous xanthan gum solution, a softwood fiber suspension, and a microfibrillated cellulose suspension. The measurement setup enables not only the analysis of the rheological (bulk) behavior of a studied fluid but gives simultaneously information on their wall layer dynamics, both of which are needed for analyzing and solving practical fluid flow-related problems. Preliminary novel results on rheological and boundary layer flow properties of the working fluids are reported and the potential of the hybrid measurement setup is demonstrated.

Prediction and uncertainty analysis of surface and groundwater exchange in a Rhine floodplain in south-west Germany

NASA Astrophysics Data System (ADS)

Maier, Nadine; Breuer, Lutz; Kraft, Philipp

2017-04-01

Inundations and the resulting exchange between surface water and groundwater are of importance for all floodplain ecosystems. Because of the high groundwater level in floodplains and the groundwater dependence of floodplain vegetation habitat models of floodplains should include detailed information of groundwater and surface water dynamics. Such models can, for example, serve as a basis for restoration measures, focusing on the re-establishment of rare species. To capture these groundwater and surface water dynamics we use a distributed model approach to simulate the groundwater levels in a floodplain stream section of the Rhine in Hesse, Germany (14.8 km2). This area is part of the large nature reserve "Kühkopf-Knoblochsaue" and hosts rare and endangered flora and fauna. We developed a physical-deterministic model of a floodplain to simulate the groundwater situation and the flooding events in the floodplain. The model is built with the Catchment Modeling Framework (CMF) and includes the interaction of groundwater and surface water flow. To reduce the computation time of the model, we used a simple flood distribution scheme instead of solving the St. Venant equation for surface water fluxes. The floodplain is split into two sub-regions, according to the two nature reserve regions with the same model setup. Each model divides the study area laterally into irregular polygonal cells (270 - 400) with different sizes (114 - 480'000 m2), based on similar elevation and land use. For each sub-region the water level of the Rhine and the groundwater levels of three monitoring wells at the boundary of the model area are used as driving factors. As predictor variables we use observation data from four to six different groundwater monitoring wells in the sub-regions. For each model we run 5,000 simulations following a Latin Hypercube sampling procedure to investigate parameter uncertainty and derive behavioral model runs. We received RMSEs between 0.18 and 0.28 m for the different groundwater wells for the calibration period of 2.5 years and RMSEs between 0.16 and 0.23 m for the validation period of 9.5 years. Finally, we derived hydrological predictors (e.g. longest flooding period, amount of flooding days during the vegetation period, etc) from the model runs for following habitat models.

GRAPhEME: a setup to measure (n, xn γ) reaction cross sections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henning, Greg; Bacquias, A.; Capdevielle, O.

2015-07-01

Most of nuclear reactor developments are using evaluated data base for numerical simulations. However, the considered databases present still large uncertainties and disagreements. To improve their level of precision, new measurements are needed, in particular for (n, xn) reactions, which are of great importance as they modify the neutron spectrum, the neutron population, and produce radioactive species. The IPHC group started an experimental program to measure (n, xn gamma) reaction cross sections using prompt gamma spectroscopy and neutron energy determination by time of flight. Measurements of (n, xn gamma) cross section have been performed for {sup 235,238}U, {sup 232}Th, {supmore » nat,182,183,184,186}W, {sup nat}Zr. The experimental setup is installed at the neutron beam at GELINA (Geel, Belgium). The setup has recently been upgraded with the addition of a highly segmented 36 pixels planar HPGe detector. Significant efforts have been made to reduce radiation background and electromagnetic perturbations. The setup is equipped with a high rate digital acquisition system. The analysis of the segmented detector data requires a specific procedure to account for cross signals between pixels. An overall attention is paid to the precision of the measurement. The setup characteristic and the analysis procedure will be presented along with the acquisition and analysis challenges. Examples of results and their impact on models will be discussed. (authors)« less

Set-up of a decision support system to support sustainable development of the Laguna de Bay, Philippines.

PubMed

Nauta, Tjitte A; Bongco, Alicia E; Santos-Borja, Adelina C

2003-01-01

Over recent decades, population expansion, deforestation, land conversion, urbanisation, intense fisheries and industrialisation have produced massive changes in the Laguna de Bay catchment, Philippines. The resulting problems include rapid siltation of the lake, eutrophication, inputs of toxics, flooding problems and loss of biodiversity. Rational and systematic resolution of conflicting water use and water allocation interests is now urgently needed in order to ensure sustainable use of the water resources. With respect to the competing and conflicting pressures on the water resources, the Laguna Lake Development Authority (LLDA) needs to achieve comprehensive management and development of the area. In view of these problems and needs, the Government of the Netherlands was funding a two-year project entitled 'Sustainable Development of the Laguna de Bay Environment'.A comprehensive tool has been developed to support decision-making at catchment level. This consists of an ArcView GIS-database linked to a state-of-the-art modelling suite, including hydrological and waste load models for the catchment area and a three-dimensional hydrodynamic and water quality model (Delft3D) linked to a habitat evaluation module for the lake. In addition, MS Office based tools to support a stakeholder analysis and financial and economic assessments have been developed. The project also focused on technical studies relating to dredging, drinking water supply and infrastructure works. These aimed to produce technically and economically feasible solutions to water quantity and quality problems. The paper also presents the findings of a study on the development of polder islands in the Laguna de Bay, addressing the water quantity and quality problems and focusing on the application of the decision support system.

The effect of porosity and flexibility on the hydrodynamics behind a mangrove-like root model

NASA Astrophysics Data System (ADS)

Kazemi, Amirkhosro; Parry, Samantha; van de Riet, Keith; Curet, Oscar

2015-11-01

Mangroves play a prominent role in coastal areas in subtropics regions. Mangrove forests are of special interest to protect shorelines against storm surges, hurricane winds, sea-level rise and tsunamis. In addition, mangroves play a critical role in filtering water and providing habitat to different organisms. In this work we study the complex interaction of water flow and mangrove roots which were modeled with a circular array of cylinders with different spacing between them as well as different configurations. In addition, we modeled the flexibility of the roots by attaching rigid cylinders to torsional connectors. The models were tested in a water tunnel for a range of Reynolds number from 2200 to 12000. In a series of experiments we measured the drag force, instant and mean velocity behind the models. We also performed 2D flow visualization for the models in a flowing soap film setup. The results show that the minimum velocity of the wake is highly dependent on the porosity and flexibility of the roots. We observed that there is a small-scale turbulent region. This turbulence is recombined downstream in a larger vortex structure eventually forming a von Karman vortex street wake. We compare the results from rigid cylinder and the flexible counterpart.

Measurement of isoprene solubility in water, human blood and plasma by multiple headspace extraction gas chromatography coupled with solid phase microextraction.

PubMed

Mochalski, Paweł; King, Julian; Kupferthaler, Alexander; Unterkofler, Karl; Hinterhuber, Hartmann; Amann, Anton

2011-12-01

The aim of this study was to determine the solubility (liquid-to-air ratios) of isoprene in water, human blood and plasma. To this end, an experimental setup combining multiple headspace extraction, solid phase microextraction and gas chromatography-mass spectrometry was applied. The water:air partition coefficients of isoprene were determined for the temperature range 4.5-37 °C and amounted to 1.171-0.277 (g mL(l)(-1)) (g mL(a)(-1))(-1). On the basis of these data, the enthalpy of volatilization was calculated as 29.46 ± 2.83 kJ mol(-1). The blood:air partition coefficients at 37 °C were determined for ten normal healthy volunteers spread around a median value of 0.95 ± 0.09 (g mL(l)(-1)) (g mL(a)(-1))(-1) and were approximately 16% lower than the plasma:air partition coefficients (1.11 ± 0.2). The applied methodology can be particularly attractive for solubility studies targeting species at very low concentrations in the solution, i.e. when headspace sample enrichment is necessary to provide sufficient measurement sensitivity and reliability. This can be especially helpful if environmental or physiological solute levels have to be considered.

Automated extraction of DNA from blood and PCR setup using a Tecan Freedom EVO liquid handler for forensic genetic STR typing of reference samples.

PubMed

Stangegaard, Michael; Frøslev, Tobias G; Frank-Hansen, Rune; Hansen, Anders J; Morling, Niels

2011-04-01

We have implemented and validated automated protocols for DNA extraction and PCR setup using a Tecan Freedom EVO liquid handler mounted with the Te-MagS magnetic separation device (Tecan, Männedorf, Switzerland). The protocols were validated for accredited forensic genetic work according to ISO 17025 using the Qiagen MagAttract DNA Mini M48 kit (Qiagen GmbH, Hilden, Germany) from fresh whole blood and blood from deceased individuals. The workflow was simplified by returning the DNA extracts to the original tubes minimizing the risk of misplacing samples. The tubes that originally contained the samples were washed with MilliQ water before the return of the DNA extracts. The PCR was setup in 96-well microtiter plates. The methods were validated for the kits: AmpFℓSTR Identifiler, SGM Plus and Yfiler (Applied Biosystems, Foster City, CA), GenePrint FFFL and PowerPlex Y (Promega, Madison, WI). The automated protocols allowed for extraction and addition of PCR master mix of 96 samples within 3.5h. In conclusion, we demonstrated that (1) DNA extraction with magnetic beads and (2) PCR setup for accredited, forensic genetic short tandem repeat typing can be implemented on a simple automated liquid handler leading to the reduction of manual work, and increased quality and throughput. Copyright © 2011 Society for Laboratory Automation and Screening. Published by Elsevier Inc. All rights reserved.

Optimized 31P MRS in the human brain at 7 T with a dedicated RF coil setup

PubMed Central

van de Bank, Bart L.; Orzada, Stephan; Smits, Frits; Lagemaat, Miriam W.; Rodgers, Christopher T.; Bitz, Andreas K.

2015-01-01

The design and construction of a dedicated RF coil setup for human brain imaging (1H) and spectroscopy (31P) at ultra‐high magnetic field strength (7 T) is presented. The setup is optimized for signal handling at the resonance frequencies for 1H (297.2 MHz) and 31P (120.3 MHz). It consists of an eight‐channel 1H transmit–receive head coil with multi‐transmit capabilities, and an insertable, actively detunable 31P birdcage (transmit–receive and transmit only), which can be combined with a seven‐channel receive‐only 31P array. The setup enables anatomical imaging and 31P studies without removal of the coil or the patient. By separating transmit and receive channels and by optimized addition of array signals with whitened singular value decomposition we can obtain a sevenfold increase in SNR of 31P signals in the occipital lobe of the human brain compared with the birdcage alone. These signals can be further enhanced by 30 ± 9% using the nuclear Overhauser effect by B 1‐shimmed low‐power irradiation of water protons. Together, these features enable acquisition of 31P MRSI at high spatial resolutions (3.0 cm3 voxel) in the occipital lobe of the human brain in clinically acceptable scan times (~15 min). © 2015 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd. PMID:26492089

Hydrological Modeling of Rainfall-Watershed-Bioretention System with EPA SWMM

NASA Astrophysics Data System (ADS)

gülbaz, sezar; melek kazezyılmaz-alhan, cevza

2016-04-01

Water resources should be protected for the sustainability of water supply and water quality. Human activities such as high urbanization with lack of infrastructure system and uncontrolled agricultural facilities adversely affect the water resources. Therefore, recent techniques should be investigated in detail to avoid present and future problems like flood, drought and water pollution. Low Impact Development-Best Management Practice (LID-BMP) is such a technique to manage storm water runoff and quality. There are several LID storm water BMPs such as bioretention facilities, rain gardens, storm water wetlands, vegetated rooftops, rain barrels, vegetative swales and permeable pavements. Bioretention is a type of Low Impact Developments (LIDs) implemented to diminish adverse effects of urbanization by reducing peak flows over the surface and improving surface water quality simultaneously. Different soil types in different ratios are considered in bioretention design which affects the performance of bioretention systems. Therefore, in this study, a hydrologic model for bioretention is developed by using Environmental Protection Agency Storm Water Management Model (EPA SWMM). Part of the input data is supplied to the hydrologic model by experimental setup called Rainfall-Watershed-Bioretention (RWB). RWB System is developed to investigate the relation among rainfall, watershed and bioretention. This setup consists of three main parts which are artificial rainfall system, drainage area and four bioretention columns with different soil mixture. EPA SWMM is a dynamic simulation model for the surface runoff which develops on a watershed during a rainfall event. The model is commonly used to plan, analyze, and control storm water runoff, to design drainage system components and to evaluate watershed management of both urban and rural areas. Furthermore, EPA SWMM is a well-known program to model LID-Bioretention in the literature. Therefore, EPA SWMM is employed in drainage and bioretention modeling. Calibration of hydrologic model is made using part of the measured data in RWB System for drainage area and for each bioretention column separately. Finally, performance of the model is evaluated by comparing the model results with the experimental data collected in RWB system.

Waiweras Warmwasserreservoir - Welche Aussagekraft haben Modelle?

NASA Astrophysics Data System (ADS)

Kühn, Michael; Altmannsberger, Charlotte; Hens, Carmen

2016-06-01

The warm water geothermal reservoir below the village of Waiwera in New Zealand has been known by the native Maori for centuries. Development by the European immigrants began in 1863. Until the year 1969, the warm water flowing from all drilled wells was artesian. Due to overproduction, water up to 50 °C now needs to be pumped to surface. Further, between 1975 and 1976, all warm water seeps on the beach of Waiwera ran dry. Within the context of sustainable water management, hydrogeological models must be developed as part of a management plan. Approaches of varying complexity have been set-up and applied since the 1980s. However, none of the models directly provide all results required for optimal water management. Answers are given simply to parts of the questions, nonetheless improving resource management of the geothermal reservoir.

Wind effects on water and salt loss in playa lakes

NASA Astrophysics Data System (ADS)

Torgersen, T.

1984-10-01

The theory behind wind stress induced setup of water surface slope on a playa lake is reviewed. Due to the low gradient of the bottom in most playa lakes (1-20 cm km -1), the advance and retreat of lake waters due to wind stress can expose or cover many square kilometers. It is even possible for the surface slope to exceed the bottom slope and thereby create a "roving" lake. Such water movements can transport lake water over undersaturated "shore" sediments and water can therefore infiltrate and be lost without an increase in lake salinity. This case is demonstrated with data from Lake George, New South Wales, Australia. Such wind effects need to be examined for their relation to the diagenesis of sediments, the composition of the bitterns, and the salt budget of playa lakes.

Cone-Beam Computed Tomography–Guided Positioning of Laryngeal Cancer Patients with Large Interfraction Time Trends in Setup and Nonrigid Anatomy Variations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gangsaas, Anne, E-mail: a.gangsaas@erasmusmc.nl; Astreinidou, Eleftheria; Quint, Sandra

2013-10-01

Purpose: To investigate interfraction setup variations of the primary tumor, elective nodes, and vertebrae in laryngeal cancer patients and to validate protocols for cone beam computed tomography (CBCT)-guided correction. Methods and Materials: For 30 patients, CBCT-measured displacements in fractionated treatments were used to investigate population setup errors and to simulate residual setup errors for the no action level (NAL) offline protocol, the extended NAL (eNAL) protocol, and daily CBCT acquisition with online analysis and repositioning. Results: Without corrections, 12 of 26 patients treated with radical radiation therapy would have experienced a gradual change (time trend) in primary tumor setup ≥4more » mm in the craniocaudal (CC) direction during the fractionated treatment (11/12 in caudal direction, maximum 11 mm). Due to these trends, correction of primary tumor displacements with NAL resulted in large residual CC errors (required margin 6.7 mm). With the weekly correction vector adjustments in eNAL, the trends could be largely compensated (CC margin 3.5 mm). Correlation between movements of the primary and nodal clinical target volumes (CTVs) in the CC direction was poor (r{sup 2}=0.15). Therefore, even with online setup corrections of the primary CTV, the required CC margin for the nodal CTV was as large as 6.8 mm. Also for the vertebrae, large time trends were observed for some patients. Because of poor CC correlation (r{sup 2}=0.19) between displacements of the primary CTV and the vertebrae, even with daily online repositioning of the vertebrae, the required CC margin around the primary CTV was 6.9 mm. Conclusions: Laryngeal cancer patients showed substantial interfraction setup variations, including large time trends, and poor CC correlation between primary tumor displacements and motion of the nodes and vertebrae (internal tumor motion). These trends and nonrigid anatomy variations have to be considered in the choice of setup verification protocol and planning target volume margins. eNAL could largely compensate time trends with minor prolongation of fraction time.« less

SU-F-J-142: Proposed Method to Broaden Inclusion Potential of Patients Able to Use the Calypso Tracking System in Prostate Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fiedler, D; Kuo, H; Bodner, W

2016-06-15

Purpose: To introduce a non-standard method of patient setup, using BellyBoard immobilization, to better utilize the localization and tracking potential of an RF-beacon system with EBRT for prostate cancer. Methods: An RF-beacon phantom was imaged using a wide bore CT scanner, both in a standard level position and with a known rotation (4° pitch and 7.5° yaw). A commercial treatment planning system (TPS) was used to determine positional coordinates of each beacon, and the centroid of the three beacons for both setups. For each setup at the Linac, kV AP and Rt Lateral images were obtained. A full characterization ofmore » the RF-beacon system in clinical mode was completed for various beacons’ array-to-centroid distances, which includes vertical, lateral, and longitudinal offset data, as well as pitch and yaw offset measurements for the tilted phantom. For the single patient who has been setup using the proposed BellyBoard method, a supine simulation was first obtained. When abdominal protrusion was found to be exceeding the limits of the RF-Beacon system through distance-based analysis in the TPS, the patient is re-simulated prone with the BellyBoard. Array to centroid distance is measured again in the TPS, and if found to be within the localization or tracking region it is applied. Results: Characterization of limitations for the RF-beacon system in clinical mode showed acceptable consistency of offset determination for phantom setup accuracy. The nonstandard patient setup method reduced the beacons’ centroid-to-array distance by 8.32cm, from 25.13cm to 16.81cm; completely out of tracking range (greater than 20cm) to within setup tracking range (less than 20cm). Conclusion: Using the RF-beacon system in combination with this novel patient setup can allow patients who would otherwise not be candidates for beacon enhanced EBRT to now be able to benefit from the reduced PTV margins of this treatment method.« less

Spatio-temporal image-based parametric water surface reconstruction: a novel methodology based on refraction

NASA Astrophysics Data System (ADS)

Engelen, L.; Creëlle, S.; Schindfessel, L.; De Mulder, T.

2018-03-01

This paper presents a low-cost and easy-to-implement image-based reconstruction technique for laboratory experiments, which results in a temporal description of the water surface topography. The distortion due to refraction of a known pattern, located below the water surface, is used to fit a low parameter surface model that describes the time-dependent and three-dimensional surface variation. Instead of finding the optimal water depth for characteristic points on the surface, the deformation of the entire pattern is compared to its original shape. This avoids the need for feature tracking adopted in similar techniques, which improves the robustness to suboptimal optical conditions and small-scale, high-frequency surface perturbations. Experimental validation, by comparison with water depth measurements using a level gauge and pressure sensor, proves sub-millimetre accuracy for smooth and steady surface shapes. Although such accuracy cannot be achieved in case of highly dynamic surface phenomena, the low-frequency and large-scale free surface oscillations can still be measured with a temporal and spatial resolution mostly limited by the available optical set-up. The technique is initially intended for periodic surface phenomena, but the results presented in this paper indicate that also irregular surface shapes can robustly be reconstructed. Therefore, the presented technique is a promising tool for other research applications that require non-intrusive, low-cost surface measurements while maintaining visual access to the water below the surface. The latter ensures that the suggested surface reconstruction is compatible with simultaneous image-based velocity measurements, enabling a detailed study of the flow.

Complex magnetic susceptibility setup for spectroscopy in the extremely low-frequency range.

PubMed

Kuipers, B W M; Bakelaar, I A; Klokkenburg, M; Erné, B H

2008-01-01

A sensitive balanced differential transformer was built to measure complex initial parallel magnetic susceptibility spectra in the 0.01-1000 Hz range. The alternating magnetic field can be chosen sufficiently weak that the magnetic structure of the samples is only slightly perturbed and the low frequencies make it possible to study the rotational dynamics of large magnetic colloidal particles or aggregates dispersed in a liquid. The distinguishing features of the setup are the novel multilayered cylindrical coils with a large sample volume and a large number of secondary turns (55 000) to measure induced voltages with a good signal-to-noise ratio, the use of a dual channel function generator to provide an ac current to the primary coils and an amplitude- and phase-adjusted compensation voltage to the dual phase differential lock-in amplifier, and the measurement of several vector quantities at each frequency. We present the electrical impedance characteristics of the coils, and we demonstrate the performance of the setup by measurement on magnetic colloidal dispersions covering a wide range of characteristic relaxation frequencies and magnetic susceptibilities, from chi approximately -10(-5) for pure water to chi>1 for concentrated ferrofluids.

The WeIzmann Supercooled Droplets Observation on a Microarray (WISDOM) and application for ambient dust

NASA Astrophysics Data System (ADS)

Reicher, Naama; Segev, Lior; Rudich, Yinon

2018-01-01

The WeIzmann Supercooled Droplets Observation on Microarray (WISDOM) is a new setup for studying ice nucleation in an array of monodisperse droplets for atmospheric implications. WISDOM combines microfluidics techniques for droplets production and a cryo-optic stage for observation and characterization of freezing events of individual droplets. This setup is designed to explore heterogeneous ice nucleation in the immersion freezing mode, down to the homogeneous freezing of water (235 K) in various cooling rates (typically 0.1-10 K min-1). It can also be used for studying homogeneous freezing of aqueous solutions in colder temperatures. Frozen fraction, ice nucleation active surface site densities and freezing kinetics can be obtained from WISDOM measurements for hundreds of individual droplets in a single freezing experiment. Calibration experiments using eutectic solutions and previously studied materials are described. WISDOM also allows repeatable cycles of cooling and heating for the same array of droplets. This paper describes the WISDOM setup, its temperature calibration, validation experiments and measurement uncertainties. Finally, application of WISDOM to study the ice nucleating particle (INP) properties of size-selected ambient Saharan dust particles is presented.

Gas-phase lifetimes of nucleobase analogues by picosecond pumpionization and streak techniques.

PubMed

Blaser, Susan; Frey, Hans-Martin; Heid, Cornelia G; Leutwyler, Samuel

2014-01-01

The picosecond (ps) timescale is relevant for the investigation of many molecular dynamical processes such as fluorescence, nonradiative relaxation, intramolecular vibrational relaxation, molecular rotation and intermolecular energy transfer, to name a few. While investigations of ultrafast (femtosecond) processes of biological molecules, e.g. nucleobases and their analogues in the gas phase are available, there are few investigations on the ps time scale. We have constructed a ps pump-ionization setup and a ps streak camera fluorescence apparatus for the determination of lifetimes of supersonic jet-cooled and isolated molecules and clusters. The ps pump-ionization setup was used to determine the lifetimes of the nucleobase analogue 2-aminopurine (2AP) and of two 2AP˙(H2O)n water cluster isomers with n=1 and 2. Their lifetimes lie between 150 ps and 3 ns and are strongly cluster-size dependent. The ps streak camera setup was used to determine accurate fluorescence lifetimes of the uracil analogue 2-pyridone (2PY), its self-dimer (2PY)2, two isomers of its trimer (2PY)3 and its tetramer (2PY)4, which lie in the 7-12 ns range.

The use of wind tunnel facilities to estimate hydrodynamic data

NASA Astrophysics Data System (ADS)

Hoffmann, Kristoffer; Tophøj Rasmussen, Johannes; Hansen, Svend Ole; Reiso, Marit; Isaksen, Bjørn; Egeberg Aasland, Tale

2016-03-01

Experimental laboratory testing of vortex-induced structural oscillations in flowing water is an expensive and time-consuming procedure, and the testing of high Reynolds number flow regimes is complicated due to the requirement of either a large-scale or high-speed facility. In most cases, Reynolds number scaling effects are unavoidable, and these uncertainties have to be accounted for, usually by means of empirical rules-of-thumb. Instead of performing traditional hydrodynamic measurements, wind tunnel testing in an appropriately designed experimental setup may provide an alternative and much simpler and cheaper framework for estimating the structural behavior under water current and wave loading. Furthermore, the fluid velocities that can be obtained in a wind tunnel are substantially higher than in a water testing facility, thus decreasing the uncertainty from scaling effects. In a series of measurements, wind tunnel testing has been used to investigate the static response characteristics of a circular and a rectangular section model. Motivated by the wish to estimate the vortex-induced in-line vibration characteristics of a neutrally buoyant submerged marine structure, additional measurements on extremely lightweight, helium-filled circular section models were conducted in a dynamic setup. During the experiment campaign, the mass of the model was varied in order to investigate how the mass ratio influences the vibration amplitude. The results show good agreement with both aerodynamic and hydrodynamic experimental results documented in the literature.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Björklund, Sebastian, E-mail: sebastianbjorklund@gmail.com; Kocherbitov, Vitaly; Biofilms—Research Center for Biointerfaces, Malmö University, Malmö

A new method to determine water sorption-desorption isotherms with high resolution in the complete range of water activities (relative humidities) is presented. The method is based on quartz crystal microbalance with dissipation monitoring (QCM-D). The QCM-D is equipped with a humidity module in which the sample film is kept in air with controlled humidity. The experimental setup allows for continuous scanning of the relative humidity from either dry to humid conditions or vice versa. The amount of water sorbed or desorbed from the sample is determined from the resonance frequencies of the coated quartz sensor, via analysis of the overtonemore » dependence. In addition, the method allows for characterization of hydration induced changes of the rheological properties from the dissipation data, which is closely connected to the viscoelasticity of the film. The accuracy of the humidity scanning setup is confirmed in control experiments. Sorption-desorption isotherms of pig gastric mucin and lysozyme, obtained by the new method, show good agreement with previous results. Finally, we show that the deposition technique used to coat the quartz sensor influences the QCM-D data and how this issue can be used to obtain further information on the effect of hydration. In particular, we demonstrate that spin-coating represents an attractive alternative to obtain sorption-desorption isotherms, while drop-coating provides additional information on changes of the rheological properties during hydration.« less

A set-up for simultaneous measurement of second harmonic generation and streaming potential and some test applications.

PubMed

Lützenkirchen, Johannes; Scharnweber, Tim; Ho, Tuan; Striolo, Alberto; Sulpizi, Marialore; Abdelmonem, Ahmed

2018-06-15

We present a measurement cell that allows simultaneous measurement of second harmonic generation (SHG) and streaming potential (SP) at mineral-water interfaces with flat specimen that are suitable for non-linear optical (NLO) studies. The set-up directly yields SHG data for the interface of interest and can also be used to obtain information concerning the influence of flow on NLO signals from that interface. The streaming potential is at present measured against a reference substrate (PTFE). The properties of this inert reference can be independently determined for the same conditions. With the new cell, for the first time the SHG signal and the SP for flat surfaces have been simultaneously measured on the same surface. This can in turn be used to unambiguously relate the two observations for identical solution composition. The SHG test of the cell with a fluorite sample confirmed previously observed differences in NLO signal under flow vs. no flow conditions in sum frequency generation (SFG) investigations. As a second test surface, an inert ("hydrophobic") OTS covered sapphire-c electrolyte interface was studied to verify the zeta-potential measurements with the new cell. For this system we obtained combined zeta-potential/SHG data in the vicinity of the point of zero charge, which were found to be proportional to each other as expected. Furthermore, on the accessible time scales of the SHG measurements no effects of flow, flow velocity and stopped flow occurred on the interfacial water structure. This insensitivity to flow for the inert surface was corroborated by concomitant molecular dynamics simulations. Finally, the set-up was used for simultaneous measurements of the two properties as a function of pH in automated titrations with an oxidic surface. Different polarization combinations obtained in two separate titrations, yielded clearly different SHG data, while under identical conditions zeta-potentials were exactly reproduced. The polarization combination that is characteristic for dipoles perpendicular to the surface scaled with the zeta-potentials over the pH-range studied, while the other did not. The work provides an advanced approach for investigating liquid/surface interactions which play a major role in our environment. The set-up can be upgraded for SFG studies, which will allow more detailed studies on the chemistry and the water structure at a given interface, but also the combined study of specific adsorption including kinetics in combination with electrokinetics. Such investigations are crucial for the basic understanding of many environmental processes from aquatic to atmospheric systems. Copyright © 2018 Elsevier Inc. All rights reserved.

Quantum-projection-noise-limited interferometry with coherent atoms in a Ramsey-type setup

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doering, D.; McDonald, G.; Debs, J. E.

2010-04-15

Every measurement of the population in an uncorrelated ensemble of two-level systems is limited by what is known as the quantum projection noise limit. Here, we present quantum-projection-noise-limited performance of a Ramsey-type interferometer using freely propagating coherent atoms. The experimental setup is based on an electro-optic modulator in an inherently stable Sagnac interferometer, optically coupling the two interfering atomic states via a two-photon Raman transition. Going beyond the quantum projection noise limit requires the use of reduced quantum uncertainty (squeezed) states. The experiment described demonstrates atom interferometry at the fundamental noise level and allows the observation of possible squeezing effectsmore » in an atom laser, potentially leading to improved sensitivity in atom interferometers.« less

A Simple and Reliable Setup for Monitoring Corrosion Rate of Steel Rebars in Concrete

PubMed Central

Jibran, Mohammed Abdul Azeem; Azad, Abul Kalam

2014-01-01

The accuracy in the measurement of the rate of corrosion of steel in concrete depends on many factors. The high resistivity of concrete makes the polarization data erroneous due to the Ohmic drop. The other source of error is the use of an arbitrarily assumed value of the Stern-Geary constant for calculating corrosion current density. This paper presents the outcomes of a research work conducted to develop a reliable and low-cost experimental setup and a simple calculation procedure that can be utilised to calculate the corrosion current density considering the Ohmic drop compensation and the actual value of the Stern-Geary constants calculated using the polarization data. The measurements conducted on specimens corroded to different levels indicate the usefulness of the developed setup to determine the corrosion current density with and without Ohmic drop compensation. PMID:24526907

A novel experimental setup for energy loss and charge state measurements in dense moderately coupled plasma using laser-heated hohlraum targets

NASA Astrophysics Data System (ADS)

Ortner, A.; Schumacher, D.; Cayzac, W.; Frank, A.; Basko, M. M.; Bedacht, S.; Blazevic, A.; Faik, S.; Kraus, D.; Rienecker, T.; Schaumann, G.; Tauschwitz, An.; Wagner, F.; Roth, M.

2016-03-01

We report on a new experimental setup for ion energy loss measurements in dense moderately coupled plasma which has recently been developed and tested at GSI Darmstadt. A partially ionized, moderately coupled carbon plasma (ne ≤ 0.8• 1022 cm-3, Te = 15 eV, z = 2.5, Γ = 0.5) is generated by volumetrical heating of two thin carbon foils with soft X-rays. This plasma is then probed by a bunched heavy ion beam. For that purpose, a special double gold hohlraum target of sub-millimeter size has been developed which efficiently converts intense laser light into thermal radiation and guarantees a gold-free interaction path for the ion beam traversing the carbon plasma. This setup allows to do precise energy loss measurements in non-ideal plasma at the level of 10 percent solid-state density.

Percentage depth dose calculation accuracy of model based algorithms in high energy photon small fields through heterogeneous media and comparison with plastic scintillator dosimetry

PubMed Central

Mani, Ganesh Kadirampatti; Karunakaran, Kaviarasu

2016-01-01

Small fields smaller than 4×4 cm2 are used in stereotactic and conformal treatments where heterogeneity is normally present. Since dose calculation accuracy in both small fields and heterogeneity often involves more discrepancy, algorithms used by treatment planning systems (TPS) should be evaluated for achieving better treatment results. This report aims at evaluating accuracy of four model‐based algorithms, X‐ray Voxel Monte Carlo (XVMC) from Monaco, Superposition (SP) from CMS‐Xio, AcurosXB (AXB) and analytical anisotropic algorithm (AAA) from Eclipse are tested against the measurement. Measurements are done using Exradin W1 plastic scintillator in Solid Water phantom with heterogeneities like air, lung, bone, and aluminum, irradiated with 6 and 15 MV photons of square field size ranging from 1 to 4 cm2. Each heterogeneity is introduced individually at two different depths from depth‐of‐dose maximum (Dmax), one setup being nearer and another farther from the Dmax. The central axis percentage depth‐dose (CADD) curve for each setup is measured separately and compared with the TPS algorithm calculated for the same setup. The percentage normalized root mean squared deviation (%NRMSD) is calculated, which represents the whole CADD curve's deviation against the measured. It is found that for air and lung heterogeneity, for both 6 and 15 MV, all algorithms show maximum deviation for field size 1×1 cm2 and gradually reduce when field size increases, except for AAA. For aluminum and bone, all algorithms' deviations are less for 15 MV irrespective of setup. In all heterogeneity setups, 1×1 cm2 field showed maximum deviation, except in 6 MV bone setup. All algorithms in the study, irrespective of energy and field size, when any heterogeneity is nearer to Dmax, the dose deviation is higher compared to the same heterogeneity far from the Dmax. Also, all algorithms show maximum deviation in lower‐density materials compared to high‐density materials. PACS numbers: 87.53.Bn, 87.53.kn, 87.56.bd, 87.55.Kd, 87.56.jf PMID:26894345

A facile, bio-based, novel approach for synthesis of covalently functionalized graphene nanoplatelet nano-coolants toward improved thermo-physical and heat transfer properties.

PubMed

Sadri, Rad; Hosseini, Maryam; Kazi, S N; Bagheri, Samira; Abdelrazek, Ali H; Ahmadi, Goodarz; Zubir, Nashrul; Ahmad, Roslina; Abidin, N I Z

2018-01-01

In this study, we synthesized covalently functionalized graphene nanoplatelet (GNP) aqueous suspensions that are highly stable and environmentally friendly for use as coolants in heat transfer systems. We evaluated the heat transfer and hydrodynamic properties of these nano-coolants flowing through a horizontal stainless steel tube subjected to a uniform heat flux at its outer surface. The GNPs functionalized with clove buds using the one-pot technique. We characterized the clove-treated GNPs (CGNPs) using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). We then dispersed the CGNPs in distilled water at three particle concentrations (0.025, 0.075 and 0.1wt%) in order to prepare the CGNP-water nanofluids (nano-coolants). We used ultraviolet-visible (UV-vis) spectroscopy to examine the stability and solubility of the CGNPs in the distilled water. There is significant enhancement in thermo-physical properties of CGNPs nanofluids relative those for distilled water. We validated our experimental set-up by comparing the friction factor and Nusselt number for distilled water obtained from experiments with those determined from empirical correlations, indeed, our experimental set-up is reliable and produces results with reasonable accuracy. We conducted heat transfer experiments for the CGNP-water nano-coolants flowing through the horizontal heated tube in fully developed turbulent condition. Our results are indeed promising since there is a significant enhancement in the Nusselt number and convective heat transfer coefficient for the CGNP-water nanofluids, with only a negligible increase in the friction factor and pumping power. More importantly, we found that there is a significant increase in the performance index, which is a positive indicator that our nanofluids have potential to substitute conventional coolants in heat transfer systems because of their overall thermal performance and energy savings benefits. Copyright © 2017 Elsevier Inc. All rights reserved.

An ultra-stable optical frequency reference for space

NASA Astrophysics Data System (ADS)

Schuldt, T.; Döringshoff, K.; Kovalchuk, E.; Pahl, J.; Gohlke, M.; Weise, D.; Johann, U.; Peters, A.; Braxmaier, C.

2017-11-01

We realized ultra-stable optical frequency references on elegant breadboard (EBB) and engineering model (EM) level utilizing Doppler-free spectroscopy of molecular iodine near 532nm. A frequency stability of about 1•10-14 at an integration time of 1 s and below 5•10-15 at integration times between 10 s and 100 s was achieved. These values are comparable to the currently best laboratory setups. Both setups use a baseplate made of glass material where the optical components are joint using a specific assembly-integration technology. Compared to the EBB setup, the EM setup is further developed with respect to compactness and mechanical and thermal stability. The EM setup uses a baseplate made of fused silica with dimensions of 380 x 180 x 40 mm3 and a specifically designed 100 x 100 x 30 mm3 rectangular iodine cell in nine-pass configuration with a specific robust cold finger design. The EM setup was subjected to thermal cycling and vibrational testing. Applications of such an optical frequency reference in space can be found in fundamental physics, geoscience, Earth observation, and navigation & ranging. One example is the proposed mSTAR (mini SpaceTime Asymmetry Research) mission, dedicated to perform a Kennedy-Thorndike experiment on a satellite in a sunsynchronous low-Earth orbit. By comparing an iodine standard to a cavity-based frequency reference and integration over 2 year mission lifetime, the Kennedy-Thorndike coefficient will be determined with up to two orders of magnitude higher accuracy than the current best ground experiment. In a current study, the compatibility of the payload with the SaudiSat-4 host vehicle is investigated.

Eddy Covariance measurements of stable isotopes (δD and δ18O) in water vapor

NASA Astrophysics Data System (ADS)

Braden-Behrens, Jelka; Knohl, Alexander

2017-04-01

Stable isotopes are a promising tool to enhance our understanding of ecosystem gas exchanges. Studying 18O and 2H in water vapour (H2Ov) can e.g. help partitioning evapotranspiration into its components. With recent developments in laser spectroscopy direct Eddy Covariance (EC) measurements for investigating fluxes of stable isotopologues became feasible. So far very few case studies have applied the EC method to measure stable isotopes in water vapor. We continuously measure fluxes of water vapor isotopologues with the EC method in a managed beech forest in Thuringia, Germany, since autumn 2015 using the following setup: An off-axis integrated cavity output water vapor isotope analyzer (WVIA, Los Gatos Research. Inc, USA) measures the water vapour concentration and its isotopic composition (δD and δ18O). The instrument, that was optimized for high flow rates (app. 4slpm) to generate high frequency (2Hz) measurements, showed sufficient precision with Allan Deviations of app. 0.12 ‰ for δD and 0.06 ‰ for δ18O for averaging periods of 100s. The instrument was calibrated hourly using a high-flow optimized version of the water vapor isotope standard source (WVISS, Los Gatos Research. Inc, USA) that provides water vapor with known isotopic composition for a large range of different concentrations. Our calibration scheme includes a near continuous concentration range calibration instead of a simple 2 or 3-point calibration to face the analyzers strong concentration dependency within a range of app. 6 000 to 16 000 ppm in winter and app. 8 000 to 23 000 ppm in summer. In the used setup, the high-flow and high-frequency optimized water vapor isotope analyzer (WVIA) showed suitable characteristics (Allan deviation and spectral energy distribution) to perform Eddy covariance measurements of stable isotopes in H2Ov. Thus, this novel instrument for EC measurements of water vapor isotopologues provides a new opportunity for studying the hydrological cycle in long-term observation networks like Fluxnet and ICOS.

The impact of future sea-level rise on the global tides

NASA Astrophysics Data System (ADS)

Pickering, M. D.; Horsburgh, K. J.; Blundell, J. R.; Hirschi, J. J.-M.; Nicholls, R. J.; Verlaan, M.; Wells, N. C.

2017-06-01

Tides are a key component in coastal extreme water levels. Possible changes in the tides caused by mean sea-level rise (SLR) are therefore of importance in the analysis of coastal flooding, as well as many other applications. We investigate the effect of future SLR on the tides globally using a fully global forward tidal model: OTISmpi. Statistical comparisons of the modelled and observed tidal solutions demonstrate the skill of the refined model setup with no reliance on data assimilation. We simulate the response of the four primary tidal constituents to various SLR scenarios. Particular attention is paid to future changes at the largest 136 coastal cities, where changes in water level would have the greatest impact. Spatially uniform SLR scenarios ranging from 0.5 to 10 m with fixed coastlines show that the tidal amplitudes in shelf seas globally respond strongly to SLR with spatially coherent areas of increase and decrease. Changes in the M2 and S2 constituents occur globally in most shelf seas, whereas changes in K1 and O1 are confined to Asian shelves. With higher SLR tidal changes are often not proportional to the SLR imposed and larger portions of mean high water (MHW) changes are above proportional. Changes in MHW exceed ±10% of the SLR at 10% of coastal cities. SLR scenarios allowing for coastal recession tend increasingly to result in a reduction in tidal range. The fact that the fixed and recession shoreline scenarios result mainly in changes of opposing sign is explained by the effect of the perturbations on the natural period of oscillation of the basin. Our results suggest that coastal management strategies could influence the sign of the tidal amplitude change. The effect of a spatially varying SLR, in this case fingerprints of the initial elastic response to ice mass loss, modestly alters the tidal response with the largest differences at high latitudes.

An FDTD-based computer simulation platform for shock wave propagation in electrohydraulic lithotripsy.

PubMed

Yılmaz, Bülent; Çiftçi, Emre

2013-06-01

Extracorporeal Shock Wave Lithotripsy (ESWL) is based on disintegration of the kidney stone by delivering high-energy shock waves that are created outside the body and transmitted through the skin and body tissues. Nowadays high-energy shock waves are also used in orthopedic operations and investigated to be used in the treatment of myocardial infarction and cancer. Because of these new application areas novel lithotriptor designs are needed for different kinds of treatment strategies. In this study our aim was to develop a versatile computer simulation environment which would give the device designers working on various medical applications that use shock wave principle a substantial amount of flexibility while testing the effects of new parameters such as reflector size, material properties of the medium, water temperature, and different clinical scenarios. For this purpose, we created a finite-difference time-domain (FDTD)-based computational model in which most of the physical system parameters were defined as an input and/or as a variable in the simulations. We constructed a realistic computational model of a commercial electrohydraulic lithotriptor and optimized our simulation program using the results that were obtained by the manufacturer in an experimental setup. We, then, compared the simulation results with the results from an experimental setup in which oxygen level in water was varied. Finally, we studied the effects of changing the input parameters like ellipsoid size and material, temperature change in the wave propagation media, and shock wave source point misalignment. The simulation results were consistent with the experimental results and expected effects of variation in physical parameters of the system. The results of this study encourage further investigation and provide adequate evidence that the numerical modeling of a shock wave therapy system is feasible and can provide a practical means to test novel ideas in new device design procedures. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

On the distribution of uranium in hair: Non-destructive analysis using synchrotron radiation induced X-ray fluorescence microprobe techniques

NASA Astrophysics Data System (ADS)

Israelsson, A.; Eriksson, M.; Pettersson, H. B. L.

2015-06-01

In the present study the distribution of uranium in single human hair shafts has been evaluated using two synchrotron radiation (SR) based micro X-ray fluorescence techniques; SR μ-XRF and confocal SR μ-XRF. The hair shafts originated from persons that have been exposed to elevated uranium concentrations. Two different groups have been studied, i) workers at a nuclear fuel fabrication factory, exposed mainly by inhalation and ii) owners of drilled bedrock wells exposed by ingestion of water. The measurements were carried out on the FLUO beamline at the synchrotron radiation facility ANKA, Karlsruhe. The experiment was optimized to detect U with a beam size of 6.8 μm × 3 μm beam focus allowing detection down to ppb levels of U in 10 s (SR μ-XRF setup) and 70 s (SR confocal μ-XRF setup) measurements. It was found that the uranium was present in a 10-15 μm peripheral layer of the hair shafts for both groups studied. Furthermore, potential external hair contamination was studied by scanning of unwashed hair shafts from the workers. Sites of very high uranium signal were identified as particles containing uranium. Such particles, were also seen in complementary analyses using variable pressure electron microscope coupled with energy dispersive X-ray analyzer (ESEM-EDX). However, the particles were not visible in washed hair shafts. These findings can further increase the understanding of uranium excretion in hair and its potential use as a biomonitor.

Optimization and development of solar power system under diffused sunlight condition in rural areas with supercapacitor integration

NASA Astrophysics Data System (ADS)

Castelino, Roystan V.; Jana, Suman; Kumhar, Rajesh; Singh, Niraj K.

2018-04-01

The simulation and hardware based experiment in this presented paper shows a possibility of increasing the reliability of solar power under diffused condition by using super capacitor module. This experimental setup can be used in those areas where the sun light is intermittent and under the diffused radiation condition. Due to diffused radiation, solar PV cells operate very poorly, but by using this setup the power efficiency can be increased greatly. Sometimes dependent numerical models are used to measure the voltage and current response of the hardware setup in MATLAB Simulink based environment. To convert the scattered solar radiation to electricity using the conventional solar PV module, batteries have to be linked with the rapid charging or discharging device like super capacitor module. The conventional method consists of a charging circuit, which dumps the power if the voltage is below certain voltage level, but this circuit utilizes the entire power even if the voltage is low under diffused sun light conditions. There is no power dumped in this circuit. The efficiency and viability of this labscale experimental setup can be examined with further experiment and industrial model.

Establishing a Numerical Modeling Framework for Hydrologic Engineering Analyses of Extreme Storm Events

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Xiaodong; Hossain, Faisal; Leung, L. Ruby

In this study a numerical modeling framework for simulating extreme storm events was established using the Weather Research and Forecasting (WRF) model. Such a framework is necessary for the derivation of engineering parameters such as probable maximum precipitation that are the cornerstone of large water management infrastructure design. Here this framework was built based on a heavy storm that occurred in Nashville (USA) in 2010, and verified using two other extreme storms. To achieve the optimal setup, several combinations of model resolutions, initial/boundary conditions (IC/BC), cloud microphysics and cumulus parameterization schemes were evaluated using multiple metrics of precipitation characteristics. Themore » evaluation suggests that WRF is most sensitive to IC/BC option. Simulation generally benefits from finer resolutions up to 5 km. At the 15km level, NCEP2 IC/BC produces better results, while NAM IC/BC performs best at the 5km level. Recommended model configuration from this study is: NAM or NCEP2 IC/BC (depending on data availability), 15km or 15km-5km nested grids, Morrison microphysics and Kain-Fritsch cumulus schemes. Validation of the optimal framework suggests that these options are good starting choices for modeling extreme events similar to the test cases. This optimal framework is proposed in response to emerging engineering demands of extreme storm events forecasting and analyses for design, operations and risk assessment of large water infrastructures.« less

Medium Deep High Temperature Heat Storage

NASA Astrophysics Data System (ADS)

Bär, Kristian; Rühaak, Wolfram; Schulte, Daniel; Welsch, Bastian; Chauhan, Swarup; Homuth, Sebastian; Sass, Ingo

2015-04-01

Heating of buildings requires more than 25 % of the total end energy consumption in Germany. Shallow geothermal systems for indirect use as well as shallow geothermal heat storage systems like aquifer thermal energy storage (ATES) or borehole thermal energy storage (BTES) typically provide low exergy heat. The temperature levels and ranges typically require a coupling with heat pumps. By storing hot water from solar panels or thermal power stations with temperatures of up to 110 °C a medium deep high temperature heat storage (MDHTS) can be operated on relatively high temperature levels of more than 45 °C. Storage depths of 500 m to 1,500 m below surface avoid conflicts with groundwater use for drinking water or other purposes. Permeability is typically also decreasing with greater depth; especially in the crystalline basement therefore conduction becomes the dominant heat transport process. Solar-thermal charging of a MDHTS is a very beneficial option for supplying heat in urban and rural systems. Feasibility and design criteria of different system configurations (depth, distance and number of BHE) are discussed. One system is designed to store and supply heat (300 kW) for an office building. The required boreholes are located in granodioritic bedrock. Resulting from this setup several challenges have to be addressed. The drilling and completion has to be planned carefully under consideration of the geological and tectonical situation at the specific site.

Filling the observational void: Scientific value and quantitative validation of hydrometeorological data from a community-based monitoring programme

NASA Astrophysics Data System (ADS)

Walker, David; Forsythe, Nathan; Parkin, Geoff; Gowing, John

2016-07-01

This study shows how community-based hydrometeorological monitoring programmes can provide reliable high-quality measurements comparable to formal observations. Time series of daily rainfall, river stage and groundwater levels obtained by a local community in Dangila woreda, northwest Ethiopia, have passed accepted quality control standards and have been statistically validated against formal sources. In a region of low-density and declining formal hydrometeorological monitoring networks, a situation shared by much of the developing world, community-based monitoring can fill the observational void providing improved spatial and temporal characterisation of rainfall, river flow and groundwater levels. Such time series data are invaluable in water resource assessment and management, particularly where, as shown here, gridded rainfall datasets provide gross under or over estimations of rainfall and where groundwater level data are non-existent. Discussions with the local community during workshops held at the setup of the monitoring programme and since have demonstrated that the community have become engaged in the project and have benefited from a greater hydrological knowledge and sense of ownership of their resources. This increased understanding and empowerment is at the relevant scale required for effective community-based participatory management of shallow groundwater and river catchments.

Feasibility of using a dose-area product ratio as beam quality specifier for photon beams with small field sizes.

PubMed

Pimpinella, Maria; Caporali, Claudio; Guerra, Antonio Stefano; Silvi, Luca; De Coste, Vanessa; Petrucci, Assunta; Delaunay, Frank; Dufreneix, Stéphane; Gouriou, Jean; Ostrowsky, Aimé; Rapp, Benjamin; Bordy, Jean-Marc; Daures, Josiane; Le Roy, Maïwenn; Sommier, Line; Vermesse, Didier

2018-01-01

To investigate the feasibility of using the ratio of dose-area product at 20 cm and 10 cm water depths (DAPR 20,10 ) as a beam quality specifier for radiotherapy photon beams with field diameter below 2 cm. Dose-area product was determined as the integral of absorbed dose to water (D w ) over a surface larger than the beam size. 6 MV and 10 MV photon beams with field diameters from 0.75 cm to 2 cm were considered. Monte Carlo (MC) simulations were performed to calculate energy-dependent dosimetric parameters and to study the DAPR 20,10 properties. Aspects relevant to DAPR 20,10 measurement were explored using large-area plane-parallel ionization chambers with different diameters. DAPR 20,10 was nearly independent of field size in line with the small differences among the corresponding mean beam energies. Both MC and experimental results showed a dependence of DAPR 20,10 on the measurement setup and the surface over which D w is integrated. For a given setup, DAPR 20,10 values obtained using ionization chambers with different air-cavity diameters agreed with one another within 0.4%, after the application of MC correction factors accounting for effects due to the chamber size. DAPR 20,10 differences among the small field sizes were within 1% and sensitivity to the beam energy resulted similar to that of established beam quality specifiers based on the point measurement of D w . For a specific measurement setup and integration area, DAPR 20,10 proved suitable to specify the beam quality of small photon beams for the selection of energy-dependent dosimetric parameters. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Digital holographic interferometry: a novel optical calorimetry technique for radiation dosimetry.

PubMed

Cavan, Alicia; Meyer, Juergen

2014-02-01

To develop and demonstrate the proof-of-principle of a novel optical calorimetry method to determine radiation absorbed dose in a transparent medium. The calorimetric property of water is measured during irradiation by means of an interferometer, which detects temperature-induced changes in the refractive index that can be mathematically related to absorbed dose. The proposed method uses a technique called digital holographic interferometry (DHI), which comprises an optical laser interferometer setup and consecutive physical reconstruction of the recorded wave fronts by means of the Fresnel transform. This paper describes the conceptual framework and provides the mathematical basis for DHI dosimetry. Dose distributions from a high dose rate Brachytherapy source were measured by a prototype optical setup to demonstrate the feasibility of the approach. The developed DHI dosimeter successfully determined absorbed dose distributions in water in the region adjacent to a high dose rate Brachytherapy source. A temperature change of 0.0381 K across a distance of 6.8 mm near the source was measured, corresponding to a dose of 159.3 Gy. The standard deviation in a typical measurement set was ± 3.45 Gy (corresponding to an uncertainty in the temperature value of ± 8.3 × 10(-4) K). The relative dose fall off was in agreement with treatment planning system modeled data. First results with a prototype optical setup and a Brachytherapy source demonstrate the proof-of-principle of the approach. The prototype achieves high spatial resolution of approximately 3 × 10(-4) m. The general approach is fundamentally independent of the radiation type and energy. The sensitivity range determined indicates that the method is predominantly suitable for high dose rate applications. Further work is required to determine absolute dose in all three dimensions.

g--Acceleration of Gravity: Its Measurement from the Shape of Water by Using a Computerized Rotational System

ERIC Educational Resources Information Center

Pintao, Carlos A. F.; de Souza Filho, Moacir P.

2007-01-01

This paper proposes a different experimental setup compared with the traditional ones, in order to determine the acceleration of gravity, which is carried out by using a fluid at a constant rotation. A computerized rotational system--by using a data acquisition system with specific software, a power amplifier and a rotary motion sensor--is…

A Simple System for Observing Dynamic Phase Equilibrium via an Inquiry-Based Laboratory or Demonstration

ERIC Educational Resources Information Center

Cloonan, Carrie A.; Andrew, Julie A.; Nichol, Carolyn A.; Hutchinson, John S.

2011-01-01

This article describes an activity that can be used as an inquiry-based laboratory or demonstration for either high school or undergraduate chemistry students to provide a basis for understanding both vapor pressure and the concept of dynamic phase equilibrium. The activity includes a simple setup to create a closed system of only water liquid and…

The impact of wild birds and farm management on Campylobacter and Salmonella in small ruminants

USDA-ARS?s Scientific Manuscript database

This study was designed to evaluate the potential pathways and control of foodborne pathogen transmission between wild-birds and farm animals. At two farms, a total of 14 one-acre pastures were fenced to each host 12 sheep and 12 goats. For the control group, pastures were set-up with open water tub...

Effect of electrolytes on bubble coalescence in columns observed with visualization techniques.

PubMed

Aguilera, María Eugenia; Ojeda, Antonieta; Rondón, Carolina; López De Ramos, Aura

2002-10-01

Bubble coalescence and the effect of electrolytes on this phenomenon have been previously studied. This interfacial phenomenon has attracted attention for reactor design/operation and enhanced oil recovery. Predicting bubble coalescence may help prevent low yields in reactors and predict crude oil recovery. Because of the importance of bubble coalescence, the objectives of this work were to improve the accuracy of measuring the percentage of coalescing bubbles and to observe the interfacial gas-liquid behavior. An experimental setup was designed and constructed. Bubble interactions were monitored with a visualization setup. The percentage of air bubble coalescence was 100% in distilled water, about 50% in 0.1 M sodium chloride (NaCl) aqueous solution, and 0% in 0.145 M NaCl aqueous solution. A reduction of the contact gas-liquid area was observed in distillate water. The volume of the resulting bubble was the sum of the original bubble volumes. Repulsion of bubbles was observed in NaCl solutions exceeding 0.07 M. The percentage of bubble coalescence diminishes as the concentration of NaCl chloride increases. High-speed video recording is an accurate technique to measure the percentage of bubble coalescence, and represents an important advance in gas-liquid interfacial studies.

Intracavitary moderator balloon combined with (252)Cf brachytherapy and boron neutron capture therapy, improving dosimetry in brain tumour and infiltrations.

PubMed

Brandão, S F; Campos, T P R

2015-07-01

This article proposes a combination of californium-252 ((252)Cf) brachytherapy, boron neutron capture therapy (BNCT) and an intracavitary moderator balloon catheter applied to brain tumour and infiltrations. Dosimetric evaluations were performed on three protocol set-ups: (252)Cf brachytherapy combined with BNCT (Cf-BNCT); Cf-BNCT with a balloon catheter filled with light water (LWB) and the same set-up with heavy water (HWB). Cf-BNCT-HWB has presented dosimetric advantages to Cf-BNCT-LWB and Cf-BNCT in infiltrations at 2.0-5.0 cm from the balloon surface. However, Cf-BNCT-LWB has shown superior dosimetry up to 2.0 cm from the balloon surface. Cf-BNCT-HWB and Cf-BNCT-LWB protocols provide a selective dose distribution for brain tumour and infiltrations, mainly further from the (252)Cf source, sparing the normal brain tissue. Malignant brain tumours grow rapidly and often spread to adjacent brain tissues, leading to death. Improvements in brain radiation protocols have been continuously achieved; however, brain tumour recurrence is observed in most cases. Cf-BNCT-LWB and Cf-BNCT-HWB represent new modalities for selectively combating brain tumour infiltrations and metastasis.

Nonequilibrium free diffusion in seed leachate

NASA Astrophysics Data System (ADS)

Ortiz G., Luis; Riquelme P., Pablo; Guzmán, R.

2013-11-01

In this work, we use a Schlieren-like Near Field Scattering (SNFS) setup to study nonequilibrium free diffusion behavior of a colloidal solution obtained from seeds leachate. The main objective is to compare the temporal behavior of the diffusion coefficient of seed leachate with an electric conductivity based vigor test. SNFS sizing measurements, based on Mie theory, were carried out to ensure its reliability and sensitivity. Then, we performed a typical nonequilibrium free diffusion experiment of a glycerol-water mixture. In this way, we confirmed that SNFS setup is sensitive to giant concentration fluctuations of nanocolloidal solutions. The results obtained in this stage reproduce properly the data reported elsewhere in literature. Moreover, seed leachate diffuse, in water, in a similar way that glycerol does. In both cases we used the same method (dynamic structure factor) to determine thermo-physical properties. We show that time evolution of diffusion coefficient of Lupinus Albus leachate exhibits three defined regimes as electric conductivity measurements. The results also exhibit a correspondence between the behavior of the diffusion coefficient and electric conductivity values of the two regions in the temporal range studied. Finally, we discuss biological processes involved in germination that could modulate this dependence, and the role played by the electrolytic nature of solutes.

Characterization of poly(vinyl acetate) based floating matrix tablets.

PubMed

Strübing, Sandra; Metz, Hendrik; Mäder, Karsten

2008-03-03

Floating Kollidon SR matrix tablets containing Propranolol HCl were developed and characterized with respect to drug release characteristics and floating strength. Kollidon SR was able to delay Propranolol HCl release efficiently. Drug release kinetics was evaluated using the Korsmeyer-Peppas model and found to be governed by Fickian diffusion. Tablet floating started immediately and continued for 24 h. It was possible to monitor the floating strength of the matrix devices using a simple experimental setup. Floating strength was related to Kollidon SR level with improved floating characteristics for samples with a high polymer/drug ratio. Swelling characteristics of the tablets were analyzed by applying the equation according to Therien-Aubin et al. The influence of the polymer content on swelling characteristics was found to be only marginal. Furthermore, the new method of benchtop MRI was introduced to study the water diffusion and swelling behaviour non-invasively and continuously.

Embedded-cluster calculations in a numeric atomic orbital density-functional theory framework.

PubMed

Berger, Daniel; Logsdail, Andrew J; Oberhofer, Harald; Farrow, Matthew R; Catlow, C Richard A; Sherwood, Paul; Sokol, Alexey A; Blum, Volker; Reuter, Karsten

2014-07-14

We integrate the all-electron electronic structure code FHI-aims into the general ChemShell package for solid-state embedding quantum and molecular mechanical (QM/MM) calculations. A major undertaking in this integration is the implementation of pseudopotential functionality into FHI-aims to describe cations at the QM/MM boundary through effective core potentials and therewith prevent spurious overpolarization of the electronic density. Based on numeric atomic orbital basis sets, FHI-aims offers particularly efficient access to exact exchange and second order perturbation theory, rendering the established QM/MM setup an ideal tool for hybrid and double-hybrid level density functional theory calculations of solid systems. We illustrate this capability by calculating the reduction potential of Fe in the Fe-substituted ZSM-5 zeolitic framework and the reaction energy profile for (photo-)catalytic water oxidation at TiO2(110).

Embedded-cluster calculations in a numeric atomic orbital density-functional theory framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berger, Daniel, E-mail: daniel.berger@ch.tum.de; Oberhofer, Harald; Reuter, Karsten

2014-07-14

We integrate the all-electron electronic structure code FHI-aims into the general ChemShell package for solid-state embedding quantum and molecular mechanical (QM/MM) calculations. A major undertaking in this integration is the implementation of pseudopotential functionality into FHI-aims to describe cations at the QM/MM boundary through effective core potentials and therewith prevent spurious overpolarization of the electronic density. Based on numeric atomic orbital basis sets, FHI-aims offers particularly efficient access to exact exchange and second order perturbation theory, rendering the established QM/MM setup an ideal tool for hybrid and double-hybrid level density functional theory calculations of solid systems. We illustrate this capabilitymore » by calculating the reduction potential of Fe in the Fe-substituted ZSM-5 zeolitic framework and the reaction energy profile for (photo-)catalytic water oxidation at TiO{sub 2}(110)« less

Plant growth using EMCS hardware on the ISS.

PubMed

Iversen, Tor-Henning; Fossum, Knut R; Svare, Hakon; Johnsson, Anders; Schiller, Peter

2002-07-01

Under separate contracts with ESA (FUMO and ERM Study) and as a link in the development of the European Modular Cultivation System's (EMCS) functionality and biocompatibility, plant studies have been performed at The Plant Biocentre in Trondheim, Norway. The main goal was to test whether the breadboards containing the major components planned for use in the EMCS would be optimal for space experiments with plant material. The test plans and the experimental set-up for the verification of biocompatibility and biological functionality included the use of a few model plant species including cress (Lepidium sativum L.) and Arabidopsis thaliana. The plants were tested at different developmental levels of morphological and physiological complexity (illumination, life support, humidity control, water supply, observation, short- and long-term plant growth experiments and contamination prevention). Results from the tests show that the EMCS concept is useful for long duration plant growth on the ISS.

Heterogeneous freezing of super cooled water droplets in micrometre range- freezing on a chip

NASA Astrophysics Data System (ADS)

Häusler, Thomas; Witek, Lorenz; Felgitsch, Laura; Hitzenberger, Regina; Grothe, Hinrich

2017-04-01

A new setup to analyse the freezing behaviour of ice nucleation particles (INPs) dispersed in aqueous droplets has been developed with the aim to analyse ensembles of droplets with sizes in the micrometre range, in which INPs are immersed. Major disadvantages of conventional drop-freezing experiments like varying drop sizes or interactions between the water- oil mixture and the INP, were solved by introducing a unique freezing- chip consisting of an etched and sputtered 15x15x1 mm gold-plated silicon or pure gold film (Pummer et al., 2012; Zolles et al., 2015). Using this chip, isolated micrometre-sized droplets can be generated with sizes similar to droplets in real world clouds. The experimental set-up for drop-freezing experiments was revised and improved by establishing automated process control and image evaluation. We were able to show the efficiency and accuracy of our setup by comparing measured freezing temperatures of different INPs (Snomax®, K- feldspar, birch pollen (Betula pendula) washing water, juniper pollen suspension (Juniperus communis) and ultrapure water) with already published results (Atkinson et al., 2013; Augustin et al., 2013; Pruppacher and Klett, 1997; Pummer et al., 2012; Wex et al., 2015; Zolles et al., 2015). Comparison of our measurements with literature data show the important impact of droplet size, INP concentration and number of active sites on the T50 values. Here, the new set-up exhibits its strength in reproducibility and accuracy which is due to the defined and isolated droplets. Finally, it opens a temperature window down to -37˚ C for freezing experiments which was not accessible with former traditional approaches .Atkinson, J. D., Murray, B. J., Woodhouse, M. T., Whale, T. F., Baustian, K. J., Carslaw, K. S., Dobbie, S., O'Sullivan, D., and Malkin, T. L.: The importance of feldspar for ice nucleation by mineral dust in mixed-phase clouds (vol 498, pg 355, 2013), Nature, 500, 491-491, 2013. Augustin, S., Wex, H., Niedermeier, D., Pummer, B., Grothe, H., Hartmann, S., Tomsche, L., Clauss, T., Voigtlander, J., Ignatius, K., and Stratmann, F.: Immersion freezing of birch pollen washing water, Atmos Chem Phys, 13, 10989-11003, 2013. Pruppacher, H. R. and Klett, J. D.: Microphysics of Clouds and Precipitation, Kluwer Academic Publishers, Dordrecht, 1997. Pummer, B. G., Bauer, H., Bernardi, J., Bleicher, S., and Grothe, H.: Suspendable macromolecules are responsible for ice nucleation activity of birch and conifer pollen, Atmos Chem Phys, 12, 2541-2550, 2012. Wex, H., Augustin-Bauditz, S., Boose, Y., Budke, C., Curtius, J., Diehl, K., Dreyer, A., Frank, F., Hartmann, S., Hiranuma, N., Jantsch, E., Kanji, Z. A., Kiselev, A., Koop, T., Mohler, O., Niedermeier, D., Nillius, B., Rosch, M., Rose, D., Schmidt, C., Steinke, I., and Stratmann, F.: Intercomparing different devices for the investigation of ice nucleating particles using Snomax (R) as test substance, Atmos Chem Phys, 15, 1463-1485, 2015. Zolles, T., Burkart, J., Hausler, T., Pummer, B., Hitzenberger, R., and Grothe, H.: Identification of Ice Nucleation Active Sites on Feldspar Dust Particles, Journal of Physical Chemistry A, 119, 2692-2700, 2015.

A new test procedure to evaluate the performance of substations for collective heating systems

NASA Astrophysics Data System (ADS)

Baetens, Robin; Verhaert, Ivan

2017-11-01

The overall heat demand of a single dwelling, existing out of space heating and domestic hot water production, decreases due to higher insulation rates. Because of this, investing in efficient and renewable heat generation becomes less interesting. Therefore, to incorporate renewables or residual heat on a larger scale, district heating or collective heating systems grow in importance. Within this set-up, the substation is responsible for the interaction between local demand for comfort and overall energy performance of the collective heating system. Many different configurations of substations exist, which influence both local comfort and central system performance. Next to that, also hybrids exist with additional local energy input. To evaluate performance of such substations, a new experimental-based test procedure is developed in order to evaluate these different aspects, characterized by the two roles a substation has, namely as heat generator and as heat consumer. The advantage of this approach is that an objective comparison between individual and central systems regarding performance on delivering local comfort can be executed experimentally. The lab set-up consists out of three different subsystems, namely the central system, the domestic hot water consumption and the local space heating. The central system can work with different temperature regimes and control strategies, as these aspects have proven to have the largest influence on actual performance. The domestic hot water system is able to generate similar tap profiles according to eco-design regulation for domestic hot water generation. The space heating system is able to demand a modular heat load.

Development of a coherent optical particle spectrometer for industrial applications: a feasibility investigation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, H.T.; Bachalo, W.D.

1984-10-01

The feasibility of developing a particle-sizing instrument for in-situ measurements in industrial environments, based on the method of optical heterodyne or coherent detection, was investigated. The instrument, a coherent optical particle spectrometer, or COPS, is potentially capable of measuring several important particle parameters, such as particle size, number density, and speed, because of the versatility of the optical heterodyne method. Water droplets generated by an aerosol/particle generator were used to test the performance of the COPS. Study findings have shown that the optical setup of the COPS is extremely sensitive to even minute mechanical or acoustic vibrations. At the optimalmore » setup, the COPS performs satisfactorily and has more than adequate signal-to-noise even with a 0.5 mW He-Ne laser.« less

Thermoresponsive electrospun fibers for water harvesting applications

NASA Astrophysics Data System (ADS)

Thakur, Neha; Baji, Avinash; Ranganath, Anupama Sargur

2018-03-01

Temperature triggered switchable cellulose acetate-poly(N-isopropylacrylamide) (CA-PNIPAM) core-shell and blend nanofibers are fabricated for controlled moisture harvesting applications. Core-shell fibers are fabricated using a co-axial electrospinning setup whereas the conventional electrospinning setup is employed for fabricating the blend fibers. Investigation of their wettability behaviour demonstrated that the blend fibers are superhydrophilic whereas the core-shell fibers are hydrophilic at ambient temperature. Furthermore, both the samples have an ability to switch between the two states viz. hydrophilic to hydrophobic state based on thermal stimulus. The core-shell fibers are shown to have higher moisture sorption ability compared to the blend fibers. This study investigates the mechanism behind the switchable wettability behaviour of the core-shell fibers and demonstrates the crucial role played by the functional groups present on the surface layer of fibers in governing their moisture collection efficiency.

WE-H-BRA-05: Investigation of LET Spectral Dependence of the Biological Effects of Therapeutic Protons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guan, F; Bronk, L; Kerr, M

Purpose: To investigate the dependence of biologic effect (BE) of therapeutic protons on LET spectra by comparing BEs with equal dose-averaged LET (LETd) derived from different LET spectra using high-throughput in vitro clonogenic survival assays. Methods: We used Geant4 to design the relevant experimental setups and perform the dose, LETd, and LET spectra calculations for spot-scanning protons. The clonogenic assay was performed using the H460 lung cancer cell line cultured in 96-well plates. In the first experimental setup (S1), cells were irradiated using 127.4 MeV protons with a 93.22 mm Lucite buildup resulting in a LETd value of 3.4 keV/µmmore » in the cell layer. In the second experimental setup (S2), cells were irradiated by a combination of 127.4 MeV and 136.4 MeV protons with a 96.61 mm Lucite buildup. The LETd values in the cell layer were 11.4 keV/µm and 1.5 keV/µm respectively, but an average LETd of 3.4 keV/µm was obtained by adjusting the relative fluence of each beam. Ten discrete dose levels with 0.5 Gy increments were delivered. Results: In the two setups, the energies or LET spectra were different but resulted in identical LETd values. We quantified the dose contributions from high-LET (≥10 keV/µm, threshold determined by previous experiments) events in the LET spectra separately for these two setups as 3.2% and 10.5%. The biologic effects at each identical dose level yielded statistically significant different survival curves (extra sum-of-squares F-test, P<0.0001). The second setup with a higher contribution from high-LET events exhibited the higher biologic effect with a dose enhancement factor of 1.17±0.03 at 0.10 surviving fraction. Conclusion: The dose-averaged LET may not be an accurate indicator of the biological effects of protons. Detailed LET spectra may need to be considered explicitly to accurately quantify the biologic effects of protons. Funding Support: U19 CA021239-35, R21 CA187484-01 and MDACC-IRG.« less

Performance Analysis of Water Based Copper Oxide Nano Fluids in Heat Exchanger with Twisted Insert

NASA Astrophysics Data System (ADS)

Ashok Reddy, K.; Hanmanthu, Bhukya

2018-03-01

A new experimental setup has been designed for conducting experiments in a copper round pipe heat exchanger with inner diameter di=14.5mm and outer diameter do=16mm and length L = 1720 mm . By using two copper oxide nano concentrations of 0.1% and 0.3% with water as based fluid, the heat transfer rates have been obtained with helical twisted insert H/D=5 in turbulent flow condition. Reynolds number and friction factor with pressure gradient have been evaluated. The heat transfer rates of 0.1% conc. Nano-fluid with insert was found to be 13.77% more when compared to water.

Hydraulic logic gates: building a digital water computer

NASA Astrophysics Data System (ADS)

Taberlet, Nicolas; Marsal, Quentin; Ferrand, Jérémy; Plihon, Nicolas

2018-03-01

In this article, we propose an easy-to-build hydraulic machine which serves as a digital binary computer. We first explain how an elementary adder can be built from test tubes and pipes (a cup filled with water representing a 1, and empty cup a 0). Using a siphon and a slow drain, the proposed setup combines AND and XOR logical gates in a single device which can add two binary digits. We then show how these elementary units can be combined to construct a full 4-bit adder. The sequencing of the computation is discussed and a water clock can be incorporated so that the machine can run without any exterior intervention.

Process-based model predictions of hurricane induced morphodynamic change on low-lying barrier islands

USGS Publications Warehouse

Plant, Nathaniel G.; Thompson, David M.; Elias, Edwin; Wang, Ping; Rosati, Julie D.; Roberts, Tiffany M.

2011-01-01

Using Delft3D, a Chandeleur Island model was constructed to examine the sediment-transport patterns and morphodynamic change caused by Hurricane Katrina and similar storm events. The model setup included a coarse Gulf of Mexico domain and a nested finer-resolution Chandeleur Island domain. The finer-resolution domain resolved morphodynamic processes driven by storms and tides. A sensitivity analysis of the simulated morphodynamic response was performed to investigate the effects of variations in surge levels. The Chandeleur morphodynamic model reproduced several important features that matched observed morphodynamic changes. A simulation of bathymetric change driven by storm surge alone (no waves) along the central portion of the Chandeleur Islands showed (1) a general landward retreat and lowering of the island chain and (2) multiple breaches that increased the degree of island dissection. The locations of many of the breaches correspond with the low-lying or narrow sections of the initial bathymetry. The major part of the morphological change occurred prior to the peak of the surge when overtopping of the islands produced a strong water-level gradient and induced significant flow velocities.

Isothermal dehydration of thin films of water and sugar solutions

NASA Astrophysics Data System (ADS)

Heyd, R.; Rampino, A.; Bellich, B.; Elisei, E.; Cesàro, A.; Saboungi, M.-L.

2014-03-01

The process of quasi-isothermal dehydration of thin films of pure water and aqueous sugar solutions is investigated with a dual experimental and theoretical approach. A nanoporous paper disk with a homogeneous internal structure was used as a substrate. This experimental set-up makes it possible to gather thermodynamic data under well-defined conditions, develop a numerical model, and extract needed information about the dehydration process, in particular the water activity. It is found that the temperature evolution of the pure water film is not strictly isothermal during the drying process, possibly due to the influence of water diffusion through the cellulose web of the substrate. The role of sugar is clearly detectable and its influence on the dehydration process can be identified. At the end of the drying process, trehalose molecules slow down the diffusion of water molecules through the substrate in a more pronounced way than do the glucose molecules.

Isothermal dehydration of thin films of water and sugar solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heyd, R.; Rampino, A.; Laboratory of Physical and Macromolecular Chemistry, University of Trieste, Via Giorgieri 1, 34127 Trieste

The process of quasi-isothermal dehydration of thin films of pure water and aqueous sugar solutions is investigated with a dual experimental and theoretical approach. A nanoporous paper disk with a homogeneous internal structure was used as a substrate. This experimental set-up makes it possible to gather thermodynamic data under well-defined conditions, develop a numerical model, and extract needed information about the dehydration process, in particular the water activity. It is found that the temperature evolution of the pure water film is not strictly isothermal during the drying process, possibly due to the influence of water diffusion through the cellulose webmore » of the substrate. The role of sugar is clearly detectable and its influence on the dehydration process can be identified. At the end of the drying process, trehalose molecules slow down the diffusion of water molecules through the substrate in a more pronounced way than do the glucose molecules.« less

Effect of Climate Change and Transaction Costs on Performance of a Groundwater Market

NASA Astrophysics Data System (ADS)

Khan, H. F.; Brown, C.

2017-12-01

With surface water resources becoming increasingly stressed, groundwater extraction, much of it unmanaged, has increased globally. Incentive-based policies, such as the cap-and-trade system, have been shown to be useful in the context of groundwater management. Previous research has shown that optimal groundwater markets (i.e. incentives-based policy) outperforms water quotas (command and control policy) with regards to both economic and environmental outcomes. In this work, we investigate whether these advantages of a water market over water quotas hold when assumptions of perfect information are violated due to climate change and hydrogeologic heterogeneity. We also assess whether the benefits of a cap-and-trade system outweigh the costs of implementing it, and how changes in future climate affect the performance a cap-and trade system. We use a sub-basin of the Republican River Basin, overlying the Ogallala aquifer in the High Plains of the United States, as a case study. We develop a multi-agent system model where individual benefits of each self-interested agent are maximized subject to bounds on irrigation requirements and water use permits. This economic model is coupled with a calibrated physically based groundwater model for the study region. Results show that permitting farmers to trade results in increased economic benefits and reduced environmental violations. However, the benefits of trading are dependent on the total allocations and the resulting level of water demand. We quantify third party impacts and environmental externalities for different water allocations, and highlight the unequal distributional effects of uniform water allocations resulting in `winners' and `losers'. The study reveals that high transaction costs can reduce the efficiency of the cap-and-trade system even below that of water quotas. Future changes in climate are shown to significantly influence the dynamics of the water market, and emphasize the need to address climate sensitivity in the setup of water markets.

Toward a simple, repeatable, non-destructive approach to measuring stable-isotope ratios of water within tree stems

NASA Astrophysics Data System (ADS)

Raulerson, S.; Volkmann, T.; Pangle, L. A.

2017-12-01

Traditional methodologies for measuring ratios of stable isotopes within the xylem water of trees involve destructive coring of the stem. A recent approach involves permanently installed probes within the stem, and an on-site assembly of pumps, switching valves, gas lines, and climate-controlled structure for field deployment of a laser spectrometer. The former method limits the possible temporal resolution of sampling, and sample size, while the latter may not be feasible for many research groups. We present results from initial laboratory efforts towards developing a non-destructive, temporally-resolved technique for measuring stable isotope ratios within the xylem flow of trees. Researchers have used direct liquid-vapor equilibration as a method to measure isotope ratios of the water in soil pores. Typically, this is done by placing soil samples in a fixed container, and allowing the liquid water within the soil to come into isotopic equilibrium with the headspace of the container. Water can also be removed via cryogenic distillation or azeotropic distillation, with the resulting liquid tested for isotope ratios. Alternatively, the isotope ratios of the water vapor can be directly measured using a laser-based water vapor isotope analyzer. Well-established fractionation factors and the isotope ratios in the vapor phase are then used to calculate the isotope ratios in the liquid phase. We propose a setup which would install a single, removable chamber onto a tree, where vapor samples could non-destructively and repeatedly be taken. These vapor samples will be injected into a laser-based isotope analyzer by a recirculating gas conveyance system. A major part of what is presented here is in the procedure of taking vapor samples at 100% relative humidity, appropriately diluting them with completely dry N2 calibration gas, and injecting them into the gas conveyance system without inducing fractionation in the process. This methodology will be helpful in making temporally resolved measurements of the stable isotopes in xylem water, using a setup that can be easily repeated by other research groups. The method is anticipated to find broad application in ecohydrological analyses, and in tracer studies aimed at quantifying age distributions of soil water extracted by plant roots.

Generation of multivariate near shore extreme wave conditions based on an extreme value copula for offshore boundary conditions.

NASA Astrophysics Data System (ADS)

Leyssen, Gert; Mercelis, Peter; De Schoesitter, Philippe; Blanckaert, Joris

2013-04-01

Near shore extreme wave conditions, used as input for numerical wave agitation simulations and for the dimensioning of coastal defense structures, need to be determined at a harbour entrance situated at the French North Sea coast. To obtain significant wave heights, the numerical wave model SWAN has been used. A multivariate approach was used to account for the joint probabilities. Considered variables are: wind velocity and direction, water level and significant offshore wave height and wave period. In a first step a univariate extreme value distribution has been determined for the main variables. By means of a technique based on the mean excess function, an appropriate member of the GPD is selected. An optimal threshold for peak over threshold selection is determined by maximum likelihood optimization. Next, the joint dependency structure for the primary random variables is modeled by an extreme value copula. Eventually the multivariate domain of variables was stratified in different classes, each of which representing a combination of variable quantiles with a joint probability, which are used for model simulation. The main variable is the wind velocity, as in the area of concern extreme wave conditions are wind driven. The analysis is repeated for 9 different wind directions. The secondary variable is water level. In shallow waters extreme waves will be directly affected by water depth. Hence the joint probability of occurrence for water level and wave height is of major importance for design of coastal defense structures. Wind velocity and water levels are only dependent for some wind directions (wind induced setup). Dependent directions are detected using a Kendall and Spearman test and appeared to be those with the longest fetch. For these directions, wind velocity and water level extreme value distributions are multivariately linked through a Gumbel Copula. These distributions are stratified into classes of which the frequency of occurrence can be calculated. For the remaining directions the univariate extreme wind velocity distribution is stratified, each class combined with 5 high water levels. The wave height at the model boundaries was taken into account by a regression with the extreme wind velocity at the offshore location. The regression line and the 95% confidence limits where combined with each class. Eventually the wave period is computed by a new regression with the significant wave height. This way 1103 synthetic events were selected and simulated with the SWAN wave model, each of which a frequency of occurrence is calculated for. Hence near shore significant wave heights are obtained with corresponding frequencies. The statistical distribution of the near shore wave heights is determined by sorting the model results in a descending order and accumulating the corresponding frequencies. This approach allows determination of conditional return periods. For example, for the imposed univariate design return periods of 100 years for significant wave height and 30 years for water level, the joint return period for a simultaneous exceedance of both conditions can be computed as 4000 years. Hence, this methodology allows for a probabilistic design of coastal defense structures.

SU-F-T-515: Increased Skin Dose in Supine Craniospinal Irradiation Due to Carbon Fiber Couch and Vacuum Bag Immobilization Device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robertson, D; Zhao, Z; Wang, X

2016-06-15

Purpose: To measure the surface dose for supine craniospinal irradiation employing posterior beams, treating through an imaging couch and BlueBag immobilization device. Methods: The percentage depth dose (PDD) in the buildup region of a clinical 6 MV photon beam was measured using an Advanced Markus parallel plate ionization chamber in a solid water phantom. The PDD from a 10×10 cm{sup 2} anterior beam was measured at 100 cm SSD, simulating a traditional prone craniospinal technique. The measurements were compared to commissioning and treatment planning system data. The PDD was also measured in a posterior setup with the phantom surface layingmore » directly on the Brainlab carbon fiber imaging couch, with the phantom surface 100 cm from the source, simulating a supine craniospinal setup. The posterior measurements were repeated with a BlueBag vacuum immobilization device between the couch and phantom, with thicknesses of 1.7 cm and 5 cm. The PDD from a 10×10 cm{sup 2} field and a typical 6×30 cm{sup 2} craniospinal field were also compared. The PDDs were normalized at 5 cm to reflect typical craniospinal prescription dose normalization. Results: The measured PDD curve from the anterior setup agreed well with commissioning and treatment planning data, with surface doses of 19.9%, 28.8% and 27.7%, respectively. The surface doses of the 10×10 cm{sup 2} and 6×30 cm{sup 2} fields delivered through the imaging couch were both 122.4%. The supine setup yielded surface doses of 122.4%, 121.6%, and 119.6% for the couch only, 1.7 cm bag, and 5 cm bag setups, respectively. Conclusion: Delivering craniospinal irradiation through a carbon fiber couch removes the majority of skin sparing. The addition of a vacuum bag immobilization device restores some skin sparing, but the magnitude of this effect is negligible.« less

Inverse analysis of water profile in starch by non-contact photopyroelectric method

NASA Astrophysics Data System (ADS)

Frandas, A.; Duvaut, T.; Paris, D.

2000-07-01

The photopyroelectric (PPE) method in a non-contact configuration was proposed to study water migration in starch sheets used for biodegradable packaging. A 1-D theoretical model was developed, allowing the study of samples having a water profile characterized by an arbitrary continuous function. An experimental setup was designed or this purpose which included the choice of excitation source, detection of signals, signal and data processing, and cells for conditioning the samples. We report here the development of an inversion procedure allowing for the determination of the parameters that influence the PPE signal. This procedure led to the optimization of experimental conditions in order to identify the parameters related to the water profile in the sample, and to monitor the dynamics of the process.

Signal Processing for Determining Water Height in Steam Pipes with Dynamic Surface Conditions

NASA Technical Reports Server (NTRS)

Lih, Shyh-Shiuh; Lee, Hyeong Jae; Bar-Cohen, Yoseph

2015-01-01

An enhanced signal processing method based on the filtered Hilbert envelope of the auto-correlation function of the wave signal has been developed to monitor the height of condensed water through the steel wall of steam pipes with dynamic surface conditions. The developed signal processing algorithm can also be used to estimate the thickness of the pipe to determine the cut-off frequency for the low pass filter frequency of the Hilbert Envelope. Testing and analysis results by using the developed technique for dynamic surface conditions are presented. A multiple array of transducers setup and methodology are proposed for both the pulse-echo and pitch-catch signals to monitor the fluctuation of the water height due to disturbance, water flow, and other anomaly conditions.

Burrowing behaviour of robotic bivalves with synthetic morphologies.

PubMed

Germann, D P; Carbajal, J P

2013-12-01

Several bivalve species burrow into sandy sediments to reach their living position. There are many hypotheses concerning the functional morphology of the bivalve shell for burrowing. Observational studies are limited and often qualitative and should be complemented by a synthetic approach mimicking the burrowing process using a robotic emulation. In this paper we present a simple mechatronic set-up to mimic the burrowing behaviour of bivalves. As environment we used water and quartz sand contained in a glass tank. Bivalve shells were mathematically modelled on the computer and then materialized using a 3D printer. The burrowing motion of the shells was induced by two external linear motors. Preliminary experiments did not expose any artefacts introduced to the burrowing process by the set-up. We tested effects of shell size, shape and surface sculpturing on the burrowing performance. Neither the typical bivalve shape nor surface sculpture did have a clear positive effect on burrowing depth in the performed experiments. We argue that the presented method is a valid and promising approach to investigate the functional morphology of bivalve shells and should be improved and extended in future studies. In contrast to the observation of living bivalves, our approach offers complete control over the parameters defining shell morphology and motion pattern. The technical set-up allows the systematic variation of all parameters to quantify their effects. The major drawback of the built set-up was that the reliability and significance of the results was limited by the lack of an optimal technique to standardize the sediment state before experiments.

Radiated Emissions Test Approach

DOT National Transportation Integrated Search

2015-10-02

1. Draft Department of Transportation (DOT) Test Plan to Develop : Interference Tolerance Masks for GNSS Receivers in the L1 : Radiofrequency Band (1559 1610 MHz) provides high level : overview of radiated emissions test setup : 2. Presenta...

Exposure setup to study potential adverse effects at GSM 1800 and UMTS frequencies on the auditory systems of rats.

PubMed

Lopresto, V; Pinto, R; De Vita, A; Mancini, S; Galloni, P; Marino, C; Ravazzani, P; Lovisolo, G A

2007-01-01

To investigate possible biological effects of exposure to electromagnetic (EM) fields at the frequencies of global system for mobile communication (GSM) 1800 system and universal mobile telecommunication system (UMTS) on the auditory system of rats, an exposure setup for in vivo experiments is presented. The study was carried out in the framework of two European research projects. The target of the investigation was the cochlea. A dosimetric study was performed, both numerically and through direct measurements, to assess the interaction of the radiated fields and the dose distribution in the biological target. For the local exposure of rats, a loop antenna operating at the frequency bands of interest was designed, realised and characterised through numerical and experimental dosimetric procedures. Moreover, an exposure apparatus was set up, consisting of three arrays of four loop antennas, placed on three levels, thus allowing simultaneous exposure of 12 rats to give statistical power to the experiments. To isolate the exposure arrays, the setup was assembled by a wooden rack with EM field absorbing panels, inserted among the levels and at the four sides of the rack. Isolation was verified by direct measurements. Two exposure arrays were simultaneously supplied, whereas the third one was used for sham exposure. Blind exposure was achieved through a black box, hiding physical connections to the microwave power supply. During exposure sessions, rats were restrained in special plastic jigs for repeatable positioning, thus assuring the fixed level of dose in the target.

Study of Parameters Affecting the Level of Ultrasound Exposure with In Vitro Set-Ups

NASA Astrophysics Data System (ADS)

Leskinen, Jarkko J.; Hynynen, Kullervo

2010-03-01

Ultrasound (US) exposures are widely used with in vitro cell systems e.g. in stem cell and tissue engineering research. However, without the knowledge of factors affecting the level of US exposure, the outcome of the biological result may vary from test to test or even be misinterpreted. Thereby, some of the factors affecting in vitro US exposures were studied. The level of US exposure was characterized in standard commercial cell culturing plates. The temperature distributions were measured inside the wells using infrared camera and fine wire thermocouples, and pressure and intensity distributions using a laser vibrometer and a schlieren system. The measurements were made at operating frequency of around 1 MHz with varying temporal parameters and powers (up to 2 W of acoustic power). Heat accumulation between the wells varied up to 40-50% depending on the location of the well on the plate. This well-to-well variation was be linked to the activity of reporter plasmid on osteoblastic cells. Similar temperature variations within the wells were also measured. Small sub-wavelength change in the exposure distance or, respectively, liquid volume inside the well was found to alter the acoustic field in both magnitude and shape due the standing waves. The gathered data reveals the complexity of the acoustic field in a typical in vitro set-up and gives new information about the environment of the in vitro cells during US exposures. This data may be especially useful when US set-ups are designed or characterized.

Validation and Simulation of Ares I Scale Model Acoustic Test - 3 - Modeling and Evaluating the Effect of Rainbird Water Deluge Inclusion

NASA Technical Reports Server (NTRS)

Strutzenberg, Louise L.; Putman, Gabriel C.

2011-01-01

The Ares I Scale Model Acoustics Test (ASMAT) is a series of live-fire tests of scaled rocket motors meant to simulate the conditions of the Ares I launch configuration. These tests have provided a well documented set of high fidelity measurements useful for validation including data taken over a range of test conditions and containing phenomena like Ignition Over-Pressure and water suppression of acoustics. Building on dry simulations of the ASMAT tests with the vehicle at 5 ft. elevation (100 ft. real vehicle elevation), wet simulations of the ASMAT test setup have been performed using the Loci/CHEM computational fluid dynamics software to explore the effect of rainbird water suppression inclusion on the launch platform deck. Two-phase water simulation has been performed using an energy and mass coupled lagrangian particle system module where liquid phase emissions are segregated into clouds of virtual particles and gas phase mass transfer is accomplished through simple Weber number controlled breakup and boiling models. Comparisons have been performed to the dry 5 ft. elevation cases, using configurations with and without launch mounts. These cases have been used to explore the interaction between rainbird spray patterns and launch mount geometry and evaluate the acoustic sound pressure level knockdown achieved through above-deck rainbird deluge inclusion. This comparison has been anchored with validation from live-fire test data which showed a reduction in rainbird effectiveness with the presence of a launch mount.

Versatile Mobile and Stationary Low-Cost Approaches for Hydrological Measurements

NASA Astrophysics Data System (ADS)

Kröhnert, M.; Eltner, A.

2018-05-01

In the last decades, an increase in the number of extreme precipitation events has been observed, which leads to increasing risks for flash floods and landslides. Thereby, conventional gauging stations are indispensable for monitoring and prediction. However, they are expensive in construction, management, and maintenance. Thus, density of observation networks is rather low, leading to insufficient spatio-temporal resolution to capture hydrological extreme events that occur with short response times especially in small-scale catchments. Smaller creeks and rivers require permanent observation, as well, to allow for a better understanding of the underlying processes and to enhance forecasting reliability. Today's smartphones with inbuilt cameras, positioning sensors and powerful processing units may serve as wide-spread measurement devices for event-based water gauging during floods. With the aid of volunteered geographic information (VGI), the hydrological network of water gauges can be highly densified in its spatial and temporal domain even for currently unobserved catchments. Furthermore, stationary low-cost solutions based on Raspberry Pi imaging systems are versatile for permanent monitoring of hydrological parameters. Both complementary systems, i.e. smartphone and Raspberry Pi camera, share the same methodology to extract water levels automatically, which is explained in the paper in detail. The annotation of 3D reference data by 2D image measurements is addressed depending on camera setup and river section to be monitored. Accuracies for water stage measurements are in range of several millimetres up to few centimetres.

Forensic Hydrological Investigation of the Blanco River Flood May 2015, Wimberley, TX

NASA Astrophysics Data System (ADS)

Furl, C.

2015-12-01

A forensic hydrological investigation of a major flash flood was conducted for the Blanco River in south-central Texas. The unprecedented flood occurred during the early morning hours of May 24th leaving 12 dead in the towns of Wimberley and San Marcos. Hundreds of homes were damaged or destroyed, two reinforced concrete bridges were washed off their piers, and nearly 100 high water rescues were made the following day. The present work characterizes the meteorological setup leading to the event, describes the flood hydrology using the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model, and reports on an extensive field campaign seeking to document high water marks throughout the 1200 km2 basin. Results indicate high precipitable water values, large CAPE, and strong mid and upper level winds aided in impressive divergence over the region. This allowed for storms to continually produce heavy rainfall over the same areas. Large regions of the catchment received greater than 200 mm across the upper portion of the basin with 24 hr maximums around 330 mm. GSSHA simulations indicate good performance when compared to a stage hydrograph recorded mid-catchment. The remaining USGS gauges failed early on during the rising limb of the hydrograph. Model estimates indicate peak streamflow was approximately 5500 cms with stage values nearing 13 m as the flood wave moved through the town of Wimberley. Approximately 125 locations were examined for high water marks along the mainstem of the river using RTK GPS. Stage values ranged from 12 - 18 m.

Structure of the ordered hydration of amino acids in proteins: analysis of crystal structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biedermannová, Lada, E-mail: lada.biedermannova@ibt.cas.cz; Schneider, Bohdan

2015-10-27

The hydration of protein crystal structures was studied at the level of individual amino acids. The dependence of the number of water molecules and their preferred spatial localization on various parameters, such as solvent accessibility, secondary structure and side-chain conformation, was determined. Crystallography provides unique information about the arrangement of water molecules near protein surfaces. Using a nonredundant set of 2818 protein crystal structures with a resolution of better than 1.8 Å, the extent and structure of the hydration shell of all 20 standard amino-acid residues were analyzed as function of the residue conformation, secondary structure and solvent accessibility. Themore » results show how hydration depends on the amino-acid conformation and the environment in which it occurs. After conformational clustering of individual residues, the density distribution of water molecules was compiled and the preferred hydration sites were determined as maxima in the pseudo-electron-density representation of water distributions. Many hydration sites interact with both main-chain and side-chain amino-acid atoms, and several occurrences of hydration sites with less canonical contacts, such as carbon–donor hydrogen bonds, OH–π interactions and off-plane interactions with aromatic heteroatoms, are also reported. Information about the location and relative importance of the empirically determined preferred hydration sites in proteins has applications in improving the current methods of hydration-site prediction in molecular replacement, ab initio protein structure prediction and the set-up of molecular-dynamics simulations.« less

Brain activity and connectivity changes in response to glucose ingestion.

PubMed

van Opstal, A M; Hafkemeijer, A; van den Berg-Huysmans, A A; Hoeksma, M; Blonk, C; Pijl, H; Rombouts, S A R B; van der Grond, J

2018-05-27

The regulatory role of the brain in directing eating behavior becomes increasingly recognized. Although many areas in the brain have been found to respond to food cues, very little data is available after actual caloric intake. The aim of this study was to determine normal whole brain functional responses to ingestion of glucose after an overnight fast. Twenty-five normal weight, adult males underwent functional MRI on two separate visits. In a single-blind randomized study setup, participants received either glucose solution (50 g/300 ml of water) or plain water. We studied changes in Blood Oxygen Level Dependent (BOLD) signal, voxel-based connectivity by Eigenvector Centrality Mapping, and functional network connectivity. Ingestion of glucose led to increased centrality in the thalamus and to decreases in BOLD signal in various brain areas. Decreases in connectivity in the sensory-motor and dorsal visual stream networks were found. Ingestion of water resulted in increased centrality across the brain, and increases in connectivity in the medial and lateral visual cortex network. Increased BOLD intensity was found in the intracalcarine and cingulate cortex. Our data show that ingestion of glucose leads to decreased activity and connectivity in brain areas and networks linked to energy seeking and satiation. In contrast, drinking plain water leads to increased connectivity probably associated with continued food seeking and unfulfilled reward. Trail registration: This study combines data of two studies registered at clinicaltrails.gov under numbers NCT03202342 and NCT03247114.

Polyimide-Based Capacitive Humidity Sensor

PubMed Central

Steinmaßl, Matthias; Endres, Hanns-Erik; Drost, Andreas; Eisele, Ignaz; Kutter, Christoph; Müller-Buschbaum, Peter

2018-01-01

The development of humidity sensors with simple transduction principles attracts considerable interest by both scientific researchers and industrial companies. Capacitive humidity sensors, based on polyimide sensing material with different thickness and surface morphologies, are prepared. The surface morphology of the sensing layer is varied from flat to rough and then to nanostructure called nanograss by using an oxygen plasma etch process. The relative humidity (RH) sensor selectively responds to the presence of water vapor by a capacitance change. The interaction between polyimide and water molecules is studied by FTIR spectroscopy. The complete characterization of the prepared capacitive humidity sensor performance is realized using a gas mixing setup and an evaluation kit. A linear correlation is found between the measured capacitance and the RH level in the range of 5 to 85%. The morphology of the humidity sensing layer is revealed as an important parameter influencing the sensor performance. It is proved that a nanograss-like structure is the most effective for detecting RH, due to its rapid response and recovery times, which are comparable to or even better than the ones of commercial polymer-based sensors. This work demonstrates the readiness of the developed RH sensor technology for industrialization. PMID:29751632

A learning setup for a post-coma adolescent with profound multiple disabilities involving small forehead movements and new microswitch technology.

PubMed

Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Sigafoos, Jeff; Didden, Robert; Oliva, Doretta; Calzolari, Cinzia; Montironi, Gianluigi

2007-09-01

A learning setup was arranged for an adolescent with profound multiple disabilities and a diagnosis of vegetative state. Signs of learning by the adolescent would underline an improvement in his immediate situation with potential implications for his general prospect, and could help revise his diagnosis. The response adopted in the learning setup was forehead skin movement. The microswitch technology used for detecting such a response consisted of (a) an optic sensor (i.e., barcode reader), (b) a small tag with horizontal bars attached to the participant's forehead, and (c) an electronic control system that activated stimuli in relation to the participant's forehead responses. The study followed an ABABACAB sequence, in which A represented baseline periods, B intervention periods with stimuli contingent on the response, and C a control condition with stimuli presented non-contingently. Data showed that the level of responding during the B phases was significantly higher than the levels observed during the A phases as well as the C phase, indicating clear signs of learning. Intervention strategies based on a learning format and suitable technology might be useful to improve the situation and prospect of persons with profound multiple disabilities and a diagnosis of vegetative state.

CAOS: the nested catchment soil-vegetation-atmosphere observation platform

NASA Astrophysics Data System (ADS)

Weiler, Markus; Blume, Theresa

2016-04-01

Most catchment based observations linking hydrometeorology, ecohydrology, soil hydrology and hydrogeology are typically not integrated with each other and lack a consistent and appropriate spatial-temporal resolution. Within the research network CAOS (Catchments As Organized Systems), we have initiated and developed a novel and integrated observation platform in several catchments in Luxembourg. In 20 nested catchments covering three distinct geologies the subscale processes at the bedrock-soil-vegetation-atmosphere interface are being monitored at 46 sensor cluster locations. Each sensor cluster is designed to observe a variety of different fluxes and state variables above and below ground, in the saturated and unsaturated zone. The numbers of sensors are chosen to capture the spatial variability as well the average dynamics. At each of these sensor clusters three soil moisture profiles with sensors at different depths, four soil temperature profiles as well as matric potential, air temperature, relative humidity, global radiation, rainfall/throughfall, sapflow and shallow groundwater and stream water levels are measured continuously. In addition, most sensors also measure temperature (water, soil, atmosphere) and electrical conductivity. This setup allows us to determine the local water and energy balance at each of these sites. The discharge gauging sites in the nested catchments are also equipped with automatic water samplers to monitor water quality and water stable isotopes continuously. Furthermore, water temperature and electrical conductivity observations are extended to over 120 locations distributed across the entire stream network to capture the energy exchange between the groundwater, stream water and atmosphere. The measurements at the sensor clusters are complemented by hydrometeorological observations (rain radar, network of distrometers and dense network of precipitation gauges) and linked with high resolution meteorological models. In this presentation, we will highlight the potential of this integrated observation platform to estimate energy and water exchange between the terrestrial and aquatic systems and the atmosphere, to trace water flow pathways in the unsaturated and saturated zone, and to understand the organization of processes and fluxes and thus runoff generation at different temporal and spatial scales.

A fast signal subspace approach for the determination of absolute levels from phased microphone array measurements

NASA Astrophysics Data System (ADS)

Sarradj, Ennes

2010-04-01

Phased microphone arrays are used in a variety of applications for the estimation of acoustic source location and spectra. The popular conventional delay-and-sum beamforming methods used with such arrays suffer from inaccurate estimations of absolute source levels and in some cases also from low resolution. Deconvolution approaches such as DAMAS have better performance, but require high computational effort. A fast beamforming method is proposed that can be used in conjunction with a phased microphone array in applications with focus on the correct quantitative estimation of acoustic source spectra. This method bases on an eigenvalue decomposition of the cross spectral matrix of microphone signals and uses the eigenvalues from the signal subspace to estimate absolute source levels. The theoretical basis of the method is discussed together with an assessment of the quality of the estimation. Experimental tests using a loudspeaker setup and an airfoil trailing edge noise setup in an aeroacoustic wind tunnel show that the proposed method is robust and leads to reliable quantitative results.

Wetting properties of phospholipid dispersion on tunable hydrophobic SiO2-glass plates.

PubMed

Alexandrova, Lidia; Karakashev, Stoyan I; Grigorov, L; Phan, Chi M; Smoukov, Stoyan K

2015-06-01

We study the wetting properties of very small droplets of salty aqueous suspensions of unilamellar liposomes of DMPC (dimyristoylphosphatidylcholine), situated on SiO2-glass surfaces with different levels of hydrophobicity. We evaluated two different measures of hydrophobicity of solid surfaces - receding contact angles and the thickness of wetting films trapped between an air bubble and the solid surface at different levels of hydrophobicity. We established a good correlation between methods which differ significantly in measurement difficulty and experimental setup. We also reveal details of the mechanism of wetting of different surfaces by the DMPC liposome suspension. Hydrophilic surfaces with water contact angles in the range of 0° to 35° are readily hydrophobized by the liposomes and only showed corresponding contact angles in the range 27°-43°. For same range of surface hydrophobicities, there was a clear reduction of the thickness of the wetting films between the surface and a bubble, reaching a minimum in the 35°-40° range. At higher levels of hydrophobicity both pure water and the liposome suspension show similar contact angles, and the thickness of wetting films between a bubble and those surfaces increases in parallel. Our analysis showed that the only force able to stabilize the film under these experimental conditions is steric repulsion. The latter suggests that nanobubbles adsorbed on hydrophobic parts of the surface, and coated with a DMPC layer, may be the cause of the 40-70 nm thickness of wetting films we observe. Copyright © 2014 Elsevier B.V. All rights reserved.

Computation of an ESD-induced E-field Envirnoment and Definition of a Current Injector Test set-up at Equipment Level

NASA Astrophysics Data System (ADS)

Marque, J. P.; Issac, F.; Parmantier, J. P.; Bertuol, S.

1998-11-01

The ESD-induced electromagnetic field on a S/C is computed using the 3D PIC code GEODE. Typical E-field waveforms are deduced and a new susceptibility test at equipment level is proposed as an alternative to the plane wave approach.

Picometre and nanoradian heterodyne interferometry and its application in dilatometry and surface metrology

NASA Astrophysics Data System (ADS)

Schuldt, T.; Gohlke, M.; Kögel, H.; Spannagel, R.; Peters, A.; Johann, U.; Weise, D.; Braxmaier, C.

2012-05-01

A high-sensitivity heterodyne interferometer implementing differential wavefront sensing for tilt measurement was developed over the last few years. With this setup, using an aluminium breadboard and compact optical mounts with a beam height of 2 cm, noise levels less than 5 pm Hz-1/2 in translation and less than 10 nrad Hz-1/2 in tilt measurement, both for frequencies above 10-2 Hz, have been demonstrated. Here, a new, compact and ruggedized interferometer setup utilizing a baseplate made of Zerodur, a thermally and mechanically highly stable glass ceramic with a coefficient of thermal expansion (CTE) of 2 × 10-8 K-1, is presented. The optical components are fixed to the baseplate using a specifically developed, easy-to-handle, assembly-integration technology based on a space-qualified two-component epoxy. While developed as a prototype for future applications aboard satellite space missions (such as Laser Interferometer Space Antenna), the interferometer is used in laboratory experiments for dilatometry and surface metrology. A first dilatometer setup with a demonstrated accuracy of 10-7 K-1 in CTE measurement was realized. As it was seen that the accuracy is limited by the dimensional stability of the sample tube support, a new setup was developed utilizing Zerodur as structural material for the sample tube support. In another activity, the interferometer is used for characterization of high-quality mirror surfaces at the picometre level and for high-accuracy two-dimensional surface characterization in a prototype for industrial applications. In this paper, the corresponding designs, their realizations and first measurements of both applications in dilatometry and surface metrology are presented.

Interface Modeling for Electro-Osmosis in Subgrade Structures

DTIC Science & Technology

2004-12-01

aggregate and different clays ( kaolinite , montmorillonite , limestone and quartz sands) created to simulate below grade structures. A direct current 30...Quartz Sand 100 Sieve Ca Montmorillonite Na Montmorillonite Kaolinite The test setup used a 0.45 water to cement ratio concrete cylinder... Kaolinite cell Figure 4. Measured pH for Concrete and Na Montmorillonite cell 4 Scaling occurred at the interface between the anode

Assessing storm surge hazard and impact of sea level rise in the Lesser Antilles case study of Martinique

NASA Astrophysics Data System (ADS)

Krien, Yann; Dudon, Bernard; Roger, Jean; Arnaud, Gael; Zahibo, Narcisse

2017-09-01

In the Lesser Antilles, coastal inundations from hurricane-induced storm surges pose a great threat to lives, properties and ecosystems. Assessing current and future storm surge hazards with sufficient spatial resolution is of primary interest to help coastal planners and decision makers develop mitigation and adaptation measures. Here, we use wave-current numerical models and statistical methods to investigate worst case scenarios and 100-year surge levels for the case study of Martinique under present climate or considering a potential sea level rise. Results confirm that the wave setup plays a major role in the Lesser Antilles, where the narrow island shelf impedes the piling-up of large amounts of wind-driven water on the shoreline during extreme events. The radiation stress gradients thus contribute significantly to the total surge - up to 100 % in some cases. The nonlinear interactions of sea level rise (SLR) with bathymetry and topography are generally found to be relatively small in Martinique but can reach several tens of centimeters in low-lying areas where the inundation extent is strongly enhanced compared to present conditions. These findings further emphasize the importance of waves for developing operational storm surge warning systems in the Lesser Antilles and encourage caution when using static methods to assess the impact of sea level rise on storm surge hazard.

Automatized set-up procedure for transcranial magnetic stimulation protocols.

PubMed

Harquel, S; Diard, J; Raffin, E; Passera, B; Dall'Igna, G; Marendaz, C; David, O; Chauvin, A

2017-06-01

Transcranial Magnetic Stimulation (TMS) established itself as a powerful technique for probing and treating the human brain. Major technological evolutions, such as neuronavigation and robotized systems, have continuously increased the spatial reliability and reproducibility of TMS, by minimizing the influence of human and experimental factors. However, there is still a lack of efficient set-up procedure, which prevents the automation of TMS protocols. For example, the set-up procedure for defining the stimulation intensity specific to each subject is classically done manually by experienced practitioners, by assessing the motor cortical excitability level over the motor hotspot (HS) of a targeted muscle. This is time-consuming and introduces experimental variability. Therefore, we developed a probabilistic Bayesian model (AutoHS) that automatically identifies the HS position. Using virtual and real experiments, we compared the efficacy of the manual and automated procedures. AutoHS appeared to be more reproducible, faster, and at least as reliable as classical manual procedures. By combining AutoHS with robotized TMS and automated motor threshold estimation methods, our approach constitutes the first fully automated set-up procedure for TMS protocols. The use of this procedure decreases inter-experimenter variability while facilitating the handling of TMS protocols used for research and clinical routine. Copyright © 2017 Elsevier Inc. All rights reserved.

Optimizing MR imaging-guided navigation for focused ultrasound interventions in the brain

NASA Astrophysics Data System (ADS)

Werner, B.; Martin, E.; Bauer, R.; O'Gorman, R.

2017-03-01

MR imaging during transcranial MR imaging-guided Focused Ultrasound surgery (tcMRIgFUS) is challenging due to the complex ultrasound transducer setup and the water bolus used for acoustic coupling. Achievable image quality in the tcMRIgFUS setup using the standard body coil is significantly inferior to current neuroradiologic standards. As a consequence, MR image guidance for precise navigation in functional neurosurgical interventions using tcMRIgFUS is basically limited to the acquisition of MR coordinates of salient landmarks such as the anterior and posterior commissure for aligning a stereotactic atlas. Here, we show how improved MR image quality provided by a custom built MR coil and optimized MR imaging sequences can support imaging-guided navigation for functional tcMRIgFUS neurosurgery by visualizing anatomical landmarks that can be integrated into the navigation process to accommodate for patient specific anatomy.

Two-phase flow patterns in adiabatic and diabatic corrugated plate gaps

NASA Astrophysics Data System (ADS)

Polzin, A.-E.; Kabelac, S.; de Vries, B.

2016-09-01

Correlations for two-phase heat transfer and pressure drop can be improved considerably, when they are adapted to specific flow patterns. As plate heat exchangers find increasing application as evaporators and condensers, there is a need for flow pattern maps for corrugated plate gaps. This contribution presents experimental results on flow pattern investigations for such a plate heat exchanger background, using an adiabatic visualisation setup as well as a diabatic setup. Three characteristic flow patterns were observed in the considered range of two-phase flow: bubbly flow, film flow and slug flow. The occurrence of these flow patterns is a function of mass flux, void fraction, fluid properties and plate geometry. Two different plate geometries having a corrugation angle of 27° and 63°, respectively and two different fluids (water/air and R365mfc liquid/vapor) have been analysed. A flow pattern map using the momentum flux is presented.

Baking sunflower hulls within an aluminum envelope in a common laboratory oven yields charcoal.

PubMed

Arnal, Pablo Maximiliano

2015-01-01

Charcoals have been widely used by scientist to research the removal of contaminants from water and air. One key feature of charcoal is that it keeps macropores from the parent material - though anisotropically contracted - and can even develop meso- and micropores. However, the controlled thermochemical conversion of biomass into charcoal at laboratory scale normally requires special setups which involve either vacuum or inert gas. Those setups may not be affordable in research groups or educational institutions where the research of charcoals would be highly welcome. In this work, I propose a simple and effective method to steer the thermochemical process that converts sunflower hulls (SFH) into charcoal with basic laboratory resources. The carbonization method: •Place SFH in an airtight aluminum envelope.•Thermally treat SFH within the envelope in a common laboratory oven.•Open the envelope to obtain the carbonized sunflower hulls.

Antagonistic effect of chosen lactic acid bacteria strains on Yersinia enterocolitica species in model set-ups, meat and fermented sausages.

PubMed

Gomółka-Pawlicka, M; Uradziński, J

2003-01-01

The present study was aimed at determining the influence of 15 strains of lactic acid bacteria on the growth of 8 Yersinia enterocolitica strains in model set-ups, and in meat and ageing fermented sausages. The investigations were performed within the framework of three alternate stages which differed in respect to the products studied, the number of Lactobacillus sp. strains and, partly, methodological approach. The ratio between lactic acid bacteria and Yersinia enterocolitica strains studied was, depending on the variant of experiment, 1:1, 1:2 and 2:1, respectively. The study also considered water activity (aw) and pH of the products investigated. The results suggest that all the lactic acid bacteria strains used within the framework of the model set-ups had antagonistic effect on all the Salmonella sp. strains. However, this ability was not observed with respect to of tested lactic acid bacteria strains in meat and fermented sausage. This ability was possessed by one of the strains investigated--Lactobacillus helveticus T 78. The temperature and time of the incubation of sausages, but not aw and pH, were found to have a distinct influence on the antagonistic interaction between the bacteria tested.

Intraseasonal variability of sea level and circulation in the Gulf of Thailand: the role of the Madden-Julian Oscillation

NASA Astrophysics Data System (ADS)

Oliver, Eric C. J.

2014-01-01

Intraseasonal variability of the tropical Indo-Pacific ocean is strongly related to the Madden-Julian Oscillation (MJO). Shallow seas in this region, such as the Gulf of Thailand, act as amplifiers of the direct ocean response to surface wind forcing by efficient setup of sea level. Intraseasonal ocean variability in the Gulf of Thailand region is examined using statistical analysis of local tide gauge observations and surface winds. The tide gauges detect variability on intraseasonal time scales that is related to the MJO through its effect on local wind. The relationship between the MJO and the surface wind is strongly seasonal, being most vigorous during the monsoon, and direction-dependent. The observations are then supplemented with simulations of sea level and circulation from a fully nonlinear barotropic numerical ocean model (Princeton Ocean Model). The numerical model reproduces well the intraseasonal sea level variability in the Gulf of Thailand and its seasonal modulations. The model is then used to map the wind-driven response of sea level and circulation in the entire Gulf of Thailand. Finally, the predictability of the setup and setdown signal is discussed by relating it to the, potentially predictable, MJO index.

Influence of sea ice on Arctic coasts

NASA Astrophysics Data System (ADS)

Barnhart, K. R.; Kay, J. E.; Overeem, I.; Anderson, R. S.

2017-12-01

Coasts form the dynamic interface between the terrestrial and oceanic systems. In the Arctic, and in much of the world, the coast is a focal point for population, infrastructure, biodiversity, and ecosystem services. A key difference between Arctic and temperate coasts is the presence of sea ice. Changes in sea ice cover can influence the coast because (1) the length of the sea ice-free season controls the time over which nearshore water can interact with the land, and (2) the location of the sea ice edge controls the fetch over which storm winds can interact with open ocean water, which in turn governs nearshore water level and wave field. We first focus on the interaction of sea ice and ice-rich coasts. We combine satellite records of sea ice with a model for wind-driven storm surge and waves to estimate how changes in the sea ice-free season have impacted the nearshore hydrodynamic environment along Alaska's Beaufort Sea Coast for the period 1979-2012. This region has experienced some of the greatest changes in both sea ice cover and coastal erosion rates in the Arctic: the median length of the open-water season has expanded by 90 percent, while coastal erosion rates have more than doubled from 8.7 to 19 m yr-1. At Drew Point, NW winds increase shoreline water levels that control the incision of a submarine notch, the rate-limiting step of coastal retreat. The maximum water-level setup at Drew Point has increased consistently with increasing fetch. We extend our analysis to the entire Arctic using both satellite-based observations and global coupled climate model output from the Community Earth System Model Large Ensemble (CESM-LE) project. This 30-member ensemble employs a 1-degree version of the CESM-CAM5 historical forcing for the period 1920-2005, and RCP 8.5 forcing from 2005-2100. A control model run with constant pre-industrial (1850) forcing characterizes internal variability in a constant climate. Finally, we compare observations and model results to identify locations of both observed and expected rapid sea ice change. Based on satellite observations, the median length of the 2012 open-water season expanded by between 1.5 and 3-fold relative to 1979 over the Arctic Sea region. This results in open water during the stormy Arctic fall, with implications for not only coastal processes but for amplification of warming on land.

Cone beam CT-based set-up strategies with and without rotational correction for stereotactic body radiation therapy in the liver.

PubMed

Bertholet, Jenny; Worm, Esben; Høyer, Morten; Poulsen, Per

2017-06-01

Accurate patient positioning is crucial in stereotactic body radiation therapy (SBRT) due to a high dose regimen. Cone-beam computed tomography (CBCT) is often used for patient positioning based on radio-opaque markers. We compared six CBCT-based set-up strategies with or without rotational correction. Twenty-nine patients with three implanted markers received 3-6 fraction liver SBRT. The markers were delineated on the mid-ventilation phase of a 4D-planning-CT. One pretreatment CBCT was acquired per fraction. Set-up strategy 1 used only translational correction based on manual marker match between the CBCT and planning CT. Set-up strategy 2 used automatic 6 degrees-of-freedom registration of the vertebrae closest to the target. The 3D marker trajectories were also extracted from the projections and the mean position of each marker was calculated and used for set-up strategies 3-6. Translational correction only was used for strategy 3. Translational and rotational corrections were used for strategies 4-6 with the rotation being either vertebrae based (strategy 4), or marker based and constrained to ±3° (strategy 5) or unconstrained (strategy 6). The resulting set-up error was calculated as the 3D root-mean-square set-up error of the three markers. The set-up error of the spinal cord was calculated for all strategies. The bony anatomy set-up (2) had the largest set-up error (5.8 mm). The marker-based set-up with unconstrained rotations (6) had the smallest set-up error (0.8 mm) but the largest spinal cord set-up error (12.1 mm). The marker-based set-up with translational correction only (3) or with bony anatomy rotational correction (4) had equivalent set-up error (1.3 mm) but rotational correction reduced the spinal cord set-up error from 4.1 mm to 3.5 mm. Marker-based set-up was substantially better than bony-anatomy set-up. Rotational correction may improve the set-up, but further investigations are required to determine the optimal correction strategy.

Selection of monitoring locations for storm water quality assessment.

PubMed

Langeveld, J G; Boogaard, F; Liefting, H J; Schilperoort, R P S; Hof, A; Nijhof, H; de Ridder, A C; Kuiper, M W

2014-01-01

Storm water runoff is a major contributor to the pollution of receiving waters. Storm water characteristics may vary significantly between locations and events. Hence, for each given location, this necessitates a well-designed monitoring campaign prior to selection of an appropriate storm water management strategy. The challenge for the design of a monitoring campaign with a given budget is to balance detailed monitoring at a limited number of locations versus less detailed monitoring at a large number of locations. This paper proposes a methodology for the selection of monitoring locations for storm water quality monitoring, based on (pre-)screening, a quick scan monitoring campaign, and final selection of locations and design of the monitoring setup. The main advantage of the method is the ability to prevent the selection of monitoring locations that turn out to be inappropriate. In addition, in this study, the quick scan resulted in a first useful dataset on storm water quality and a strong indication of illicit connections at one of the monitoring locations.

Influences on water-hammer wave shape: an experimental study

NASA Astrophysics Data System (ADS)

Traudt, T.; Bombardieri, C.; Manfletti, C.

2016-09-01

Water-hammer phenomena are of strong interest in a number of different industrial fields, amongst which the space industry. Here the priming of feedlines during start-up of an engine as well as the rapid closing of valves upon shutdown may lead to pressure peaks symptomatic of a water-hammer wave. Test benches used to conduct tests on future as well as current engines are also sensitive to water-hammer waves traveling along their feedlines. To enhance the understanding of water-hammer, we investigated different configurations and their influence on the wave shape in the frequency domain. The configurations feature a coiled pipe setup with a support structure and without a support structure. Two other phenomena will be presented. We found a beat phenomenon which is likely to be the so called Poisson-coupling beat. Finally we will show that the second water-hammer peak can reach pressures a lot higher than the first peak by additive interference of the primary and secondary water-hammer wave.

A multi-imaging approach to study the root–soil interface

PubMed Central

Rudolph-Mohr, Nicole; Vontobel, Peter; Oswald, Sascha E.

2014-01-01

Background and Aims Dynamic processes occurring at the soil–root interface crucially influence soil physical, chemical and biological properties at a local scale around the roots, and are technically challenging to capture in situ. This study presents a novel multi-imaging approach combining fluorescence and neutron radiography that is able to simultaneously monitor root growth, water content distribution, root respiration and root exudation. Methods Germinated seeds of white lupins (Lupinus albus) were planted in boron-free glass rhizotrons. After 11 d, the rhizotrons were wetted from the bottom and time series of fluorescence and neutron images were taken during the subsequent day and night cycles for 13 d. The following day (i.e. 25 d after planting) the rhizotrons were again wetted from the bottom and the measurements were repeated. Fluorescence sensor foils were attached to the inner sides of the glass and measurements of oxygen and pH were made on the basis of fluorescence intensity. The experimental set-up allowed for simultaneous fluorescence imaging and neutron radiography. Key Results The interrelated patterns of root growth and distribution in the soil, root respiration, exudation and water uptake could all be studied non-destructively and at high temporal and spatial resolution. The older parts of the root system with greater root-length density were associated with fast decreases of water content and rapid changes in oxygen concentration. pH values around the roots located in areas with low soil water content were significantly lower than the rest of the root system. Conclusions The results suggest that the combined imaging set-up developed here, incorporating fluorescence intensity measurements, is able to map important biogeochemical parameters in the soil around living plants with a spatial resolution that is sufficiently high enough to relate the patterns observed to the root system. PMID:25344936

Rain water transport and storage in a model sandy soil with hydrogel particle additives.

PubMed

Wei, Y; Durian, D J

2014-10-01

We study rain water infiltration and drainage in a dry model sandy soil with superabsorbent hydrogel particle additives by measuring the mass of retained water for non-ponding rainfall using a self-built 3D laboratory set-up. In the pure model sandy soil, the retained water curve measurements indicate that instead of a stable horizontal wetting front that grows downward uniformly, a narrow fingered flow forms under the top layer of water-saturated soil. This rain water channelization phenomenon not only further reduces the available rain water in the plant root zone, but also affects the efficiency of soil additives, such as superabsorbent hydrogel particles. Our studies show that the shape of the retained water curve for a soil packing with hydrogel particle additives strongly depends on the location and the concentration of the hydrogel particles in the model sandy soil. By carefully choosing the particle size and distribution methods, we may use the swollen hydrogel particles to modify the soil pore structure, to clog or extend the water channels in sandy soils, or to build water reservoirs in the plant root zone.

Changes in the Treatment of Some Physico-Chemical Properties of Cassava Mill Effluents Using Saccharomyces cerevisiae.

PubMed

Izah, Sylvester Chibueze; Bassey, Sunday Etim; Ohimain, Elijah Ige

2017-10-16

Cassava is majorly processed into gari by smallholders in Southern Nigeria. During processing, large volume of effluents are produced in the pressing stage of cassava tuber processing. The cassava mill effluents are discharged into the soil directly and it drain into nearby pits, surface water, and canals without treatment. Cassava mill effluents is known to alter the receiving soil and water characteristics and affects the biota in such environments, such as fishes (water), domestic animals, and vegetation (soil). This study investigated the potential of Saccharomyces cerevisiae to be used for the treatment of some physicochemical properties of cassava mill effluents. S. cerevisiae was isolated from palm wine and identified based on conventional microbiological techniques, viz. morphological, cultural, and physiological/biochemical characteristics. The S. cerevisiae was inoculated into sterile cassava mill effluents and incubated for 15 days. Triplicate samples were withdrawn from the setup after the fifth day of treatment. Portable equipment was used to analyze the in-situ parameters, viz. total dissolved solids (TDS), pH, dissolved oxygen (DO), conductivity, salinity, and turbidity. Anions (nitrate, sulphate, and phosphate) and chemical oxygen demand (COD) were analyzed using spectrophotometric and open reflux methods respectively. Results showed a decline of 37.62%, 22.96%, 29.63%, 20.49%, 21.44%, 1.70%, 53.48%, 68.00%, 100%, and 74.48% in pH, conductivity, DO, TDS, salinity, sulphate, nitrate, phosphate, and COD levels respectively, and elevation of 17.17% by turbidity. The study showed that S. cerevisiae could be used for the treatment of cassava mill effluents prior to being discharged into the environment so as to reduce the pollution or contamination and toxicity levels.

Maximizing effectiveness of adaptation action in Pacific Island communities using coastal wave attenuation models

NASA Astrophysics Data System (ADS)

Jung, H.; Carruthers, T.; Allison, M. A.; Weathers, D.; Moss, L.; Timmermans, H.

2017-12-01

Pacific Island communities are highly vulnerable to the effects of climate change, specifically accelerating rates of sea level rise, changes to storm intensity and associated rainfall patterns resulting in flooding and shoreline erosion. Nature-based adaptation is being planned not only to reduce the risk from shoreline erosion, but also to support benefits of a healthy ecosystem (e.g., supporting fisheries or coral reefs). In order to assess potential effectiveness of the nature-based actions to dissipate wave energy, two-dimensional X-Beach models were developed to predict the wave attenuation effect of coastal adaptation actions at the pilot sites—the villages of Naselesele and Somosomo on Taveuni island, Fiji. Both sites are experiencing serious shoreline erosion due to sea level rise and storm wave. The water depth (single-beam bathymetry), land elevation (truck-based LiDAR), and vegetation data including stem density and height were collected in both locations in a June 2017 field experiment. Wave height and water velocity were also measured for the model setup and calibration using a series of bottom-mounted instruments deployed in the 0-15 m water depth portions of the study grid. The calibrated model will be used to evaluate a range of possible adaptation actions identified by the community members of Naselesele and Somosomo. Particularly, multiple storm scenario runs with management-relevant shoreline restoration/adaptation options will be implemented to evaluate efficiencies of each adaptation action (e.g., no action, with additional planted trees, with sand mining, with seawalls constructed with natural materials, etc.). These model results will help to better understand how proposed adaption actions may influence future shoreline change and maximize benefits to communities in island nations across the SW Pacific.

SU-F-BRD-09: Is It Sufficient to Use Only Low Density Tissue-Margin to Compensate Inter-Fractionation Setup Uncertainties in Lung Treatment?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nie, K; Yue, N; Chen, T

2014-06-15

Purpose: In lung radiation treatment, PTV is formed with a margin around GTV (or CTV/ITV). Although GTV is most likely of water equivalent density, the PTV margin may be formed with the surrounding low-density tissues, which may lead to unreal dosimetric plan. This study is to evaluate whether the concern of dose calculation inside the PTV with only low density margin could be justified in lung treatment. Methods: Three SBRT cases were analyzed. The PTV from the original plan (Plan-O) was created with a 5–10 mm margin outside the ITV to incorporate setup errors and all mobility from 10 respiratorymore » phases. Test plans were generated with the GTV shifted to the PTV edge to simulate the extreme situations with maximum setup uncertainties. Two representative positions as the very posterior-superior (Plan-PS) and anterior-inferior (Plan-AI) edge were considered. The virtual GTV was assigned a density of 1.0 g.cm−3 and surrounding lung, including the PTV margin, was defined as 0.25 g.cm−3. Also, additional plan with a 1mm tissue-margin instead of full lung-margin was created to evaluate whether a composite-margin (Plan-Comp) has a better approximation for dose calculation. All plans were generated on the average CT using Analytical Anisotropic Algorithm with heterogeneity correction on and all planning parameters/monitor unites remained unchanged. DVH analyses were performed for comparisons. Results: Despite the non-static dose distribution, the high-dose region synchronized with tumor positions. This might due to scatter conditions as greater doses were absorbed in the solid-tumor than in the surrounding low-density lungtissue. However, it still showed missing target coverage in general. Certain level of composite-margin might give better approximation for the dosecalculation. Conclusion: Our exploratory results suggest that with the lungmargin only, the planning dose of PTV might overestimate the coverage of the target during treatment. The significance of this overestimation might warrant further investigation.« less

An introduction to photocatalysis through methylene blue photodegradation

NASA Astrophysics Data System (ADS)

Petit, Matthieu; Michez, Lisa; Raimundo, Jean-Manuel; Malinowski, Tuhiti; Dumas, Philippe

2016-11-01

We described a simple experimental set-up for lab work on the photocatalytic degradation of methylene blue by TiO2 nanoparticles. The photocatalysis process can be used for many applications. Treatments for diluted wastewater industries, air purifying in underground car parks, and preventing fouling on glass surfaces, are some of the potential applications of this phenomenon. The described experiment is easy to perform and the interpretation can be easily adapted to different levels of students, from high school students demonstrating their interest in sustainable development, to students obtaining a Masters in science departments who want to propose a full explanation for all phenomena of the photocatalytic process. Starting with a description of the experimental set-up, we analysed the photocatalyst nanoparticles and applied the Langmuir-Hinshelwood model to our experimental data. Finally we briefly discussed the respective energetic levels of the photocatalyst semiconductor and methylene blue.

Experimental investigation of all-optical packet-level time slot assignment using two optical buffers cascaded.

PubMed

Sheng, Xinzhi; Feng, Zhen; Li, Bing

2013-04-20

We proposed and experimentally demonstrated all-optical packet-level time slot assignment scheme with two optical buffers cascaded. The function of time-slot interchange (TSI) was successfully implemented on two and three optical packets at a data rate of 10 Gb/s. Therefore, the functions of TSI on N packets should be implemented easily by the use of N-1 stage optical buffer. On the basis of the above experiment, we carried out the TSI experiment on four packets with the same two-stage experimental setup. Furthermore, packets compression on three optical packets was also carried out with the same experimental setup. The shortest guard time of the packets compression can reach to 13 ns due to the limit of FPGA's control accuracy. Due to the use of the same optical buffer, the proposed scheme has the advantages of simple and scalable configuration, modularization, and easy integration.

Assessing water resources in Azerbaijan using a local distributed model forced and constrained with global data

NASA Astrophysics Data System (ADS)

Bouaziz, Laurène; Hegnauer, Mark; Schellekens, Jaap; Sperna Weiland, Frederiek; ten Velden, Corine

2017-04-01

In many countries, data is scarce, incomplete and often not easily shared. In these cases, global satellite and reanalysis data provide an alternative to assess water resources. To assess water resources in Azerbaijan, a completely distributed and physically based hydrological wflow-sbm model was set-up for the entire Kura basin. We used SRTM elevation data, a locally available river map and one from OpenStreetMap to derive the drainage direction network at the model resolution of approximately 1x1 km. OpenStreetMap data was also used to derive the fraction of paved area per cell to account for the reduced infiltration capacity (c.f. Schellekens et al. 2014). We used the results of a global study to derive root zone capacity based on climate data (Wang-Erlandsson et al., 2016). To account for the variation in vegetation cover over the year, monthly averages of Leaf Area Index, based on MODIS data, were used. For the soil-related parameters, we used global estimates as provided by Dai et al. (2013). This enabled the rapid derivation of a first estimate of parameter values for our hydrological model. Digitized local meteorological observations were scarce and available only for limited time period. Therefore several sources of global meteorological data were evaluated: (1) EU-WATCH global precipitation, temperature and derived potential evaporation for the period 1958-2001 (Harding et al., 2011), (2) WFDEI precipitation, temperature and derived potential evaporation for the period 1979-2014 (by Weedon et al., 2014), (3) MSWEP precipitation (Beck et al., 2016) and (4) local precipitation data from more than 200 stations in the Kura basin were available from the NOAA website for a period up to 1991. The latter, together with data archives from Azerbaijan, were used as a benchmark to evaluate the global precipitation datasets for the overlapping period 1958-1991. By comparing the datasets, we found that monthly mean precipitation of EU-WATCH and WFDEI coincided well with NOAA stations and that MSWEP slightly overestimated precipitation amounts. On a daily basis, there were discrepancies in the peak timing and magnitude between measured precipitation and the global products. A bias between EU-WATCH and WFDEI temperature and potential evaporation was observed and to model the water balance correctly, it was needed to correct EU-WATCH to WFDEI mean monthly values. Overall, the available sources enabled rapid set-up of a hydrological model including the forcing of the model with a relatively good performance to assess water resources in Azerbaijan with a limited calibration effort and allow for a similar set-up anywhere in the world. Timing and quantification of peak volume remains a weakness in global data, making it difficult to be used for some applications (flooding) and for detailed calibration. Selecting and comparing different sources of global meteorological data is important to have a reliable set which improves model performance. - Beck et al., 2016. MSWEP: 3-hourly 0.25° global gridded precipitation (1979-2014) by merging gauge, satellite, and reanalysis data. Hydrol. Earth Syst. Sci. Discuss. - Dai Y. et al. ,2013. Development of a China Dataset of Soil Hydraulic Parameters Using Pedotransfer Functions for Land Surface Modeling. Journal of Hydrometeorology - Harding, R. et al., 2011., WATCH: Current knowledge of the Terrestrial global water cycle, J. Hydrometeorol. - Schellekens, J. et al., 2014. Rapid setup of hydrological and hydraulic models using OpenStreetMap and the SRTM derived digital elevation model. Environmental Modelling&Software - Wang-Erlandsson L. et al., 2016. Global Root Zone Storage Capacity from Satellite-Based Evaporation. Hydrology and Earth System Sciences - Weedon, G. et al., 2014. The WFDEI meteorological forcing data set: WATCH Forcing Data methodology applied to ERA-Interim reanalysis data, Water Resources Research.

Dietary choline, betaine and lecithin mitigates endosulfan-induced stress in Labeo rohita fingerlings.

PubMed

Kumar, Neeraj; Jadhao, S B; Chandan, N K; Kumar, Kundan; Jha, A K; Bhushan, S; Kumar, Saurav; Rana, R S

2012-08-01

A five-week experiment was conducted to delineate stress-mitigating effects of three different methyl donors in Labeo rohita fingerlings subjected to endosulfan toxicity. Four iso-nitrogenous and iso-caloric feed were prepared with and without supplementation of methyl donors. The feed were basal or control diet (i.e., without methyl donor supplementation), feed supplemented with choline, feed supplemented with betaine and feed supplemented with lecithin. Two hundred and twenty-five fishes were distributed randomly in five treatment groups each with three replicates. The experimental setup were normal water (without endosulfan) and fed with control diet (control group), endosulfan-treated water and fed with control diet (T₁), endosulfan-treated water and fed with choline supplemented feed (T₂), endosulfan-treated water and fed with betaine supplemented feed (T₃) and endosulfan-treated water and fed with lecithin-supplemented feed (T₄). The level of endosulfan in endosulfan treated water was maintained at the level of 1/10 of LC₅₀, that is, 0.2 ppb. During the experiment, growth performances, metabolic enzyme activity and histological examination were done to assess the effect of treatments. The growth performance (percentage weight gain, feed conversion ratio, specific growth rate and protein efficiency ratio) and nutrient digestibility were significantly different (P<0.01) in lecithin, betaine and choline fed group when compared to endosulfan-exposed group fed with basal diet. The liver LDH and MDH activity were significantly (P<0.01) improved in the groups fed with methyl donor supplemented diet. The liver AST and ALT, brain AChE and muscle ALT did not change with supplementation in the diet, but muscle ALT and G6PDH significantly (P<0.01) changed with supplementation. The gill and liver ATPase and intestinal ALP were significantly (P<0.01) noticeably changed in supplemented group. After endosulfan exposure, histopathology alter like slight large vacuolation in hepatocyte and lipoid vacuole were observed and with supplementation normal appearance of liver were observed. The chromosome aberration (karyotype) was observed in endosulfan-exposed group. The result obtained in present study concluded that inclusion of methyl donors, particularly lecithin and betaine, in feed as nutritional supplements has a potential stress-mitigating effect in L. rohita fingerlings.

Cadmium determination in natural waters at the limit imposed by European legislation by isotope dilution and TiO2 solid-phase extraction.

PubMed

García-Ruiz, Silvia; Petrov, Ivan; Vassileva, Emilia; Quétel, Christophe R

2011-11-01

The cadmium content in surface water is regulated by the last European Water Framework Directive to a maximum between 0.08 and 0.25 μg L(-1) depending on the water type and hardness. Direct measurement of cadmium at this low level is not straightforward in real samples, and we hereby propose a validated method capable of addressing cadmium content below μg L(-1) level in natural water. It is based on solid-phase extraction using TiO(2) nanoparticles as solid sorbent (0.05 g packed in mini-columns) to allow the separation and preconcentration of cadmium from the sample, combined to direct isotope dilution and detection by inductively coupled plasma mass spectrometry (ID-ICP-MS). The extraction setup is miniaturised and semi-automated to reduce risks of sample contamination and improve reproducibility. Procedural blanks for the whole measurement process were 5.3 ± 2.8 ng kg(-1) (1 s) for 50 g of ultrapure water preconcentrated ten times. Experimental conditions influencing the separation (including loading pH, sample flow rates, and acid concentration in the eluent) were evaluated. With isotope dilution the Cd recovery rate does not have to be evaluated carefully. Moreover, the mathematical model associated to IDMS is known, and provides transparency for the uncertainty propagation. Our validation protocol was in agreement with guidelines of the ISO/IEC 17025 standard (chapter 5.4.5). Firstly, we assessed the experimental factors influencing the final result. Secondly, we compared the isotope ratios measured after our separation procedure to the reference values obtained with a different protocol for the digested test material IMEP-111 (mineral feed). Thirdly, we analysed the certified reference material BCR-609 (groundwater). Finally, combined uncertainties associated to our results were estimated according to ISO-GUM guidelines (typically, 3-4% k = 2 for a cadmium content of around 100 ng kg(-1)). We applied the developed method to the groundwater and wastewater samples ERM-CA615 and BCR-713, respectively, and results agreed with certificate values within uncertainty statements.

Quantification of the impact of hydrology on agricultural production as a result of too dry, too wet or too saline conditions

NASA Astrophysics Data System (ADS)

Hack-ten Broeke, Mirjam J. D.; Kroes, Joop G.; Bartholomeus, Ruud P.; van Dam, Jos C.; de Wit, Allard J. W.; Supit, Iwan; Walvoort, Dennis J. J.; van Bakel, P. Jan T.; Ruijtenberg, Rob

2016-08-01

For calculating the effects of hydrological measures on agricultural production in the Netherlands a new comprehensive and climate proof method is being developed: WaterVision Agriculture (in Dutch: Waterwijzer Landbouw). End users have asked for a method that considers current and future climate, that can quantify the differences between years and also the effects of extreme weather events. Furthermore they would like a method that considers current farm management and that can distinguish three different causes of crop yield reduction: drought, saline conditions or too wet conditions causing oxygen shortage in the root zone. WaterVision Agriculture is based on the hydrological simulation model SWAP and the crop growth model WOFOST. SWAP simulates water transport in the unsaturated zone using meteorological data, boundary conditions (like groundwater level or drainage) and soil parameters. WOFOST simulates crop growth as a function of meteorological conditions and crop parameters. Using the combination of these process-based models we have derived a meta-model, i.e. a set of easily applicable simplified relations for assessing crop growth as a function of soil type and groundwater level. These relations are based on multiple model runs for at least 72 soil units and the possible groundwater regimes in the Netherlands. So far, we parameterized the model for the crops silage maize and grassland. For the assessment, the soil characteristics (soil water retention and hydraulic conductivity) are very important input parameters for all soil layers of these 72 soil units. These 72 soil units cover all soils in the Netherlands. This paper describes (i) the setup and examples of application of the process-based model SWAP-WOFOST, (ii) the development of the simplified relations based on this model and (iii) how WaterVision Agriculture can be used by farmers, regional government, water boards and others to assess crop yield reduction as a function of groundwater characteristics or as a function of the salt concentration in the root zone for the various soil types.

WATER FORMATION IN THE UPPER ATMOSPHERE OF THE EARLY EARTH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fleury, Benjamin; Carrasco, Nathalie; Marcq, Emmanuel

2015-07-10

The water concentration and distribution in the early Earth's atmosphere are important parameters that contribute to the chemistry and the radiative budget of the atmosphere. If the atmosphere above the troposphere is generally considered as dry, photochemistry is known to be responsible for the production of numerous minor species. Here we used an experimental setup to study the production of water in conditions simulating the chemistry above the troposphere of the early Earth with an atmospheric composition based on three major molecules: N{sub 2}, CO{sub 2}, and H{sub 2}. The formation of gaseous products was monitored using infrared spectroscopy. Watermore » was found as the major product, with approximately 10% of the gas products detected. This important water formation is discussed in the context of the early Earth.« less

Preliminary Analysis of a Water Shield for a Surface Power Reactor

NASA Technical Reports Server (NTRS)

Pearson, J. Boise

2006-01-01

A water based shielding system is being investigated for use on initial lunar surface power systems. The use of water may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. A simple 1-D thermal model indicates the necessity of natural convection to maintain acceptable temperatures and pressures in the water shield. CFD analysis is done to quantify the natural convection in the shield, and predicts sufficient natural convection to transfer heat through the shield with small temperature gradients. A test program will he designed to experimentally verify the thermal hydraulic performance of the shield, and to anchor the CFD models to experimental results.

Study on the quality and stability of compost through a Demo Compost Plant.

PubMed

Hasan, K M M; Sarkar, G; Alamgir, M; Bari, Q H; Haedrich, G

2012-11-01

This study is concerned with the performance of a Demo Compost Plant for the development of acceptable composting technology in Bangladesh. The Demo Compost Plant was setup at the adjacent area of an existing compost plant located at Khulna city in Bangladesh. Four different composting technologies were considered, where Municipal Solid Waste (MSW) were used as a raw material for composting, collected from the adjacent areas of the plant. Initially the whole composting system was conducted through two experimental setups. In the 1st setup three different types of aerators (horizontal and vertical passively aerator and forced aerator) were selected. For a necessary observation four piles, using only MSW as the input materials in the first three compost pile, the fourth one was the existing Samadhan's compost pile. Based on the analysis of the experimental findings, the horizontal passively aerated composting technique is suitable for Bangladesh as it had better performance for reducing composting period than that of the others. It was being observed from the quality parameters of compost in the both 1st and 2nd setup that as the waste directly come from kitchen, degradation rate of waste shows a positive result for reducing this waste and there is no possibility of toxic contamination, when it would be used as a soil conditioner. Though there is no significant improvement in the quality of the final product in the 2nd setup as comparing with the 1st setup but it fulfills one of the main objectives of this study is to reduce the whole composting period as well as immediate management of the increasing amount of waste and reducing load on landfill. Selfheating tests reveal that degree of stability of compost with respect to maturation period was remained in the acceptable level, which was further accelerated due to the use of organic additives. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Multi-Index Approach to Delineate Surface Water Bodies in the Pastoral Regions of Mali Using ASTER Imagery

NASA Astrophysics Data System (ADS)

Alemu, H.; Velpuri, N.; Senay, G. B.; Angerer, J.

2011-12-01

Information on the location and availability of water resources is a day-to-day challenge for pastoralists in the Sahelian region of Mali. They move seasonally along their migration corridors in search for water and forage. Satellite data can be used to map the spatial and temporal dynamics of these water resources. In this work, ASTER imagery is selected for its high (15 m) spatial resolution and suitable spectral bands for water body identification. Our research indicates that as most of the waterholes of interest in the study area are very shallow and heavily sediment-laden, using only one of those commonly used water identification indices such as the Simple Band Ratio (SBR), or the Normalized Difference Water Index (NDWI) alone does not help in effectively characterizing all the surface water bodies in the region. As a result, we used four different spectral indices to identify surface water features: (i) Simple Band Ratio (SBR), (ii) Normalized Difference Water Index (NDWI), (iii) Modified Normalized Difference Water Index (MNDWI), and (iv) the Mean Absolute Deviation (MAD) to identify and delineate surface water bodies using 91 ASTER images. Initial results indicate that the SBR method identified 17 waterholes while the NDWI 18, the MNDWI 36, and the MAD method identified 28 waterholes. However, by combining the results from the four aforementioned spectral indices following a multi-index approach, 89 waterholes that were previously unidentified by a single approach alone were identified. Furthermore, our analysis indicates that the SBR and the NDWI methods identify relatively clearer waterholes better (29% of the waterholes), whereas MNDWI and MAD proved to be good indices for identifying sediment-laden waterholes. Identifying the location and spatial distribution of surface water bodies is the first step towards monitoring their seasonal dynamics using a hydrologic modeling system, similar to an existing setup for east Africa (http://watermon.tamu.edu/). Seasonal trends in relative surface water levels are one of the most important inputs in the livestock early warning system (LEWS) along with forage and livestock market prices.

Geophysical observations at cavity collapse

NASA Astrophysics Data System (ADS)

Jousset, Philippe; Bazargan-Sabet, Behrooz; Lebert, François; Bernardie, Séverine; Gourry, Jean-Christophe

2010-05-01

In Lorraine region (France) salt layers at about 200 meters depth are exploited by Solvay using solution mining methodology which consists in extracting the salt by dissolution, collapsing the cavern overburden during the exploitation phase and finally reclaiming the landscape by creating a water area. In this process, one of the main challenges for the exploiting company is to control the initial 120-m diameter collapse so as to minimize possible damages. In order to detect potential precursors and understand processes associated with such collapses, a wide series of monitoring techniques including micro seismics, broad-band seismology, hydro-acoustic, electromagnetism, gas probing, automatic leveling, continuous GPS, continuous gravity and borehole extensometry was set-up in the frame of an in-situ study carried out by the "Research Group for the Impact and Safety of Underground Works" (GISOS, France). Equipments were set-up well before the final collapse, giving a unique opportunity to analyze a great deal of information prior to and during the collapse process which has been successfully achieved on February the 13th, 2009 by controlling the cavity internal pressure. In this work, we present the results of data recorded by a network of 3 broadband seismometers, 2 accelerometers, 2 tilt-meters and a continuously gravity meter. We relate the variations of the brine pumping rate with the evolutions of the induced geophysical signals and finally we propose a first mechanical model for describing the controlled collapse. Beyond the studied case, extrapolation of the results obtained might contribute to the understanding of uncontrolled cavity collapses, such as pit-craters or calderas at volcanoes.

Extracting Maximum Total Water Levels from Video "Brightest" Images

NASA Astrophysics Data System (ADS)

Brown, J. A.; Holman, R. A.; Stockdon, H. F.; Plant, N. G.; Long, J.; Brodie, K.

2016-02-01

An important parameter for predicting storm-induced coastal change is the maximum total water level (TWL). Most studies estimate the TWL as the sum of slowly varying water levels, including tides and storm surge, and the extreme runup parameter R2%, which includes wave setup and swash motions over minutes to seconds. Typically, R2% is measured using video remote sensing data, where cross-shore timestacks of pixel intensity are digitized to extract the horizontal runup timeseries. However, this technique must be repeated at multiple alongshore locations to resolve alongshore variability, and can be tedious and time consuming. We seek an efficient, video-based approach that yields a synoptic estimate of TWL that accounts for alongshore variability and can be applied during storms. In this work, the use of a video product termed the "brightest" image is tested; this represents the highest intensity of each pixel captured during a 10-minute collection period. Image filtering and edge detection techniques are applied to automatically determine the shoreward edge of the brightest region (i.e., the swash zone) at each alongshore pixel. The edge represents the horizontal position of the maximum TWL along the beach during the collection period, and is converted to vertical elevations using measured beach topography. This technique is evaluated using video and topographic data collected every half-hour at Duck, NC, during differing hydrodynamic conditions. Relationships between the maximum TWL estimates from the brightest images and various runup statistics computed using concurrent runup timestacks are examined, and errors associated with mapping the horizontal results to elevations are discussed. This technique is invaluable, as it can be used to routinely estimate maximum TWLs along a coastline from a single brightest image product, and provides a means for examining alongshore variability of TWLs at high alongshore resolution. These advantages will be useful in validating numerical hydrodynamic models and improving coastal change predictions.

Processes Affecting the Variability of Fluorescence Signals from Benthic Targets in Shallow Waters

DTIC Science & Technology

1998-09-30

analysis of zooxanthellae isolated from coral samples. We examined fluorescence lifetimes from benthic targets using femtosecond laser based Single...a temporal resolution 5 ps. The laser set-up was employed for laboratory studies of fluorescence lifetimes from model targets such as zooxanthellae ...seagrasses. Over 200 measurements on isolated zooxanthellae were conducted with a bench-top FRR fluorometer and Phase Shift Fluorometer. During the CoBOP-98

Intracavitary moderator balloon combined with 252Cf brachytherapy and boron neutron capture therapy, improving dosimetry in brain tumour and infiltrations

PubMed Central

Brandão, S F

2015-01-01

Objective: This article proposes a combination of californium-252 (252Cf) brachytherapy, boron neutron capture therapy (BNCT) and an intracavitary moderator balloon catheter applied to brain tumour and infiltrations. Methods: Dosimetric evaluations were performed on three protocol set-ups: 252Cf brachytherapy combined with BNCT (Cf-BNCT); Cf-BNCT with a balloon catheter filled with light water (LWB) and the same set-up with heavy water (HWB). Results: Cf-BNCT-HWB has presented dosimetric advantages to Cf-BNCT-LWB and Cf-BNCT in infiltrations at 2.0–5.0 cm from the balloon surface. However, Cf-BNCT-LWB has shown superior dosimetry up to 2.0 cm from the balloon surface. Conclusion: Cf-BNCT-HWB and Cf-BNCT-LWB protocols provide a selective dose distribution for brain tumour and infiltrations, mainly further from the 252Cf source, sparing the normal brain tissue. Advances in knowledge: Malignant brain tumours grow rapidly and often spread to adjacent brain tissues, leading to death. Improvements in brain radiation protocols have been continuously achieved; however, brain tumour recurrence is observed in most cases. Cf-BNCT-LWB and Cf-BNCT-HWB represent new modalities for selectively combating brain tumour infiltrations and metastasis. PMID:25927876

Efficient low-power wireless communication setup for an autonomous soil moisture sensor

NASA Astrophysics Data System (ADS)

Surducan, Vasile; Surducan, Emanoil

2017-12-01

During July 2016 - September 2017, a micro-irrigation system was set up and tested in field and greenhouse-like conditions, using eight inexpensive soil moisture sensors designed and manufactured in our institute. Each sensor was powered by accumulators charged by an (8 × 14) cm2 solar panel. The energy budget was carefully managed to allow long operating time for both the moisture sensor and the irrigation automation. We present here the hardware-software setup implemented in our proprietary moisture sensor for wireless communication, using Bluetooth Low Energy modules (BLE). The autonomy of the system may reach 4-5 cloudy days without the need of recharging the accumulators from the sun. Over the entire operating period, the moisture sensors send data wirelessly every sampling time (15 to 30 minutes) following water drips on the soil for the next 30 seconds, pushed by a low power micro pump. The micro-irrigation process is repeated every sampling time, until the soil moisture threshold is reached. In between the operating states, the sensor and watering automation go to sleep. The software algorithm ensures low energy (max. 2.8 mWh) consumption for the moisture sensor and 20 mWh for the irrigation automation, substantially increasing the accumulators discharge cycle.

netherland hydrological modeling instrument

NASA Astrophysics Data System (ADS)

Hoogewoud, J. C.; de Lange, W. J.; Veldhuizen, A.; Prinsen, G.

2012-04-01

Netherlands Hydrological Modeling Instrument A decision support system for water basin management. J.C. Hoogewoud , W.J. de Lange ,A. Veldhuizen , G. Prinsen , The Netherlands Hydrological modeling Instrument (NHI) is the center point of a framework of models, to coherently model the hydrological system and the multitude of functions it supports. Dutch hydrological institutes Deltares, Alterra, Netherlands Environmental Assessment Agency, RWS Waterdienst, STOWA and Vewin are cooperating in enhancing the NHI for adequate decision support. The instrument is used by three different ministries involved in national water policy matters, for instance the WFD, drought management, manure policy and climate change issues. The basis of the modeling instrument is a state-of-the-art on-line coupling of the groundwater system (MODFLOW), the unsaturated zone (metaSWAP) and the surface water system (MOZART-DM). It brings together hydro(geo)logical processes from the column to the basin scale, ranging from 250x250m plots to the river Rhine and includes salt water flow. The NHI is validated with an eight year run (1998-2006) with dry and wet periods. For this run different parts of the hydrology have been compared with measurements. For instance, water demands in dry periods (e.g. for irrigation), discharges at outlets, groundwater levels and evaporation. A validation alone is not enough to get support from stakeholders. Involvement from stakeholders in the modeling process is needed. There fore to gain sufficient support and trust in the instrument on different (policy) levels a couple of actions have been taken: 1. a transparent evaluation of modeling-results has been set up 2. an extensive program is running to cooperate with regional waterboards and suppliers of drinking water in improving the NHI 3. sharing (hydrological) data via newly setup Modeling Database for local and national models 4. Enhancing the NHI with "local" information. The NHI is and has been used for many decision supports and evaluations. The main focus of the instrument is operational drought management and evaluating adaptive measures for different climate scenario's. It has also been used though as a basis to evaluate water quality of WFD-water bodies and measures, nutrient-leaching and describing WFD groundwater bodies. There is a toolkit to translate the hydrological NHI results to values for different water users. For instance with the NHI results agricultural yields can be calculated, effects on ground water dependant ecosystems, subsidence, shipping, drinking water supply. This makes NHI a valuable decision support system in Dutch water management.

Integrated Circuit Immunity

NASA Technical Reports Server (NTRS)

Sketoe, J. G.; Clark, Anthony

2000-01-01

This paper presents a DOD E3 program overview on integrated circuit immunity. The topics include: 1) EMI Immunity Testing; 2) Threshold Definition; 3) Bias Tee Function; 4) Bias Tee Calibration Set-Up; 5) EDM Test Figure; 6) EMI Immunity Levels; 7) NAND vs. and Gate Immunity; 8) TTL vs. LS Immunity Levels; 9) TP vs. OC Immunity Levels; 10) 7805 Volt Reg Immunity; and 11) Seventies Chip Set. This paper is presented in viewgraph form.

Fast high-energy X-ray imaging for Severe Accidents experiments on the future PLINIUS-2 platform

NASA Astrophysics Data System (ADS)

Berge, L.; Estre, N.; Tisseur, D.; Payan, E.; Eck, D.; Bouyer, V.; Cassiaut-Louis, N.; Journeau, C.; Tellier, R. Le; Pluyette, E.

2018-01-01

The future PLINIUS-2 platform of CEA Cadarache will be dedicated to the study of corium interactions in severe nuclear accidents, and will host innovative large-scale experiments. The Nuclear Measurement Laboratory of CEA Cadarache is in charge of real-time high-energy X-ray imaging set-ups, for the study of the corium-water and corium-sodium interaction, and of the corium stratification process. Imaging such large and high-density objects requires a 15 MeV linear electron accelerator coupled to a tungsten target creating a high-energy Bremsstrahlung X-ray flux, with corresponding dose rate about 100 Gy/min at 1 m. The signal is detected by phosphor screens coupled to high-framerate scientific CMOS cameras. The imaging set-up is established using an experimentally-validated home-made simulation software (MODHERATO). The code computes quantitative radiographic signals from the description of the source, object geometry and composition, detector, and geometrical configuration (magnification factor, etc.). It accounts for several noise sources (photonic and electronic noises, swank and readout noise), and for image blur due to the source spot-size and to the detector unsharpness. In a view to PLINIUS-2, the simulation has been improved to account for the scattered flux, which is expected to be significant. The paper presents the scattered flux calculation using the MCNP transport code, and its integration into the MODHERATO simulation. Then the validation of the improved simulation is presented, through confrontation to real measurement images taken on a small-scale equivalent set-up on the PLINIUS platform. Excellent agreement is achieved. This improved simulation is therefore being used to design the PLINIUS-2 imaging set-ups (source, detectors, cameras, etc.).

Extension of nano-scaled exploration into solution/liquid systems using tip-enhanced Raman scattering

NASA Astrophysics Data System (ADS)

Pienpinijtham, Prompong; Vantasin, Sanpon; Kitahama, Yasutaka; Ekgasit, Sanong; Ozaki, Yukihiro

2017-08-01

This review shows updated experimental cases of tip-enhanced Raman scattering (TERS) operated in solution/liquid systems. TERS in solution/liquid is still infancy, but very essential and challenging because crucial and complicated biological processes such as photosynthesis, biological electron transfer, and cellular respiration take place and undergo in water, electrolytes, or buffers. The measurements of dry samples do not reflect real activities in those kinds of systems. To deeply understand them, TERS in solution/liquid is needed to be developed. The first TERS experiment in solution/liquid is successfully performed in 2009. After that time, TERS in solution/liquid has gradually been developed. It shows a potential to study structural changes of biomembranes, opening the world of dynamic living cells. TERS is combined with electrochemical techniques, establishing electrochemical TERS (EC-TERS) in 2015. EC-TERS creates an interesting path to fulfil the knowledge about electrochemical-related reactions or processes. TERS tip can be functionalized with sensitive molecules to act as a "surface-enhanced Raman scattering (SERS) at tip" for investigating distinct properties of systems in solution/liquid e.g., pH and electron transfer mechanism. TERS setup is continuously under developing. Versatile geometry of the setup and a guideline of a systematic implementation for a setup of TERS in solution/liquid are proposed. New style of setup is also reported for TERS imaging in solution/liquid. From all of these, TERS in solution/liquid will expand a nano-scaled exploration into solution/liquid systems of various fields e.g., energy storages, catalysts, electronic devices, medicines, alternative energy sources, and build a next step of nanoscience and nanotechnology.

An investigation comparing traditional recitation instruction to computer tutorials which combine three-dimensional animation with varying levels of visual complexity, including digital video in teaching various chemistry topics

NASA Astrophysics Data System (ADS)

Graves, A. Palmer

This study examines the effect of increasing the visual complexity used in computer assisted instruction in general chemistry. Traditional recitation instruction was used as a control for the experiment. One tutorial presented a chemistry topic using 3-D animation showing molecular activity and symbolic representation of the macroscopic view of a chemical phenomenon. A second tutorial presented the same topic but simultaneously presented students with a digital video movie showing the phenomena and 3-D animation showing the molecular view of the phenomena. This experimental set-up was used in two different experiments during the first semester of college level general chemistry course. The topics covered were the molecular effect of heating water through the solid-liquid phase change and the kinetic molecular theory used in explaining pressure changes. The subjects used in the experiment were 236 college students enrolled in a freshman chemistry course at a large university. The data indicated that the simultaneous presentation of digital video, showing the solid to liquid phase change of water, with a molecular animation, showing the molecular behavior during the phase change, had a significant effect on student particulate understanding when compared to traditional recitation. Although the effect of the KMT tutorial was not statistically significant, there was a positive effect on student particulate understanding. The use of computer tutorial also had a significant effect on student attitude toward their comprehension of the lesson.

Long-term flow monitoring of submarine gas emanations

NASA Astrophysics Data System (ADS)

Spickenbom, K.; Faber, E.; Poggenburg, J.; Seeger, C.

2009-04-01

One of the Carbon Capture and Storage (CCS) strategies currently under study is the sequestration of CO2 in sub-seabed geological formations. Even after a thorough review of the geological setting, there is the possibility of leaks from the reservoirs. As part of the EU-financed project CO2ReMoVe (Research, Monitoring, Verification), which aims to develop innovative research and technologies for monitoring and verification of carbon dioxide geological storage, we are working on the development of submarine long-term gas flow monitoring systems. Technically, however, these systems are not limited to CO2 but can be used for monitoring of any free gas emission (bubbles) on the seafloor. The basic design of the gas flow sensor system was derived from former prototypes developed for monitoring CO2 and CH4 on mud volcanoes in Azerbaijan. This design was composed of a raft floating on the surface above the gas vent to collect the bubbles. Sensors for CO2 flux and concentration and electronics for data storage and transmission were mounted on the raft, together with battery-buffered solar panels for power supply. The system was modified for installation in open sea by using a buoy instead of a raft and a funnel on the seafloor to collect the gas, which is then guided above water level through a flexible tube. Besides some technical problems (condensed water in the tube, movement of the buoys due to waves leading to biased measurement of flow rates), this setup provides a cost-effective solution for shallow waters. However, a buoy interferes with ship traffic, and it is also difficult to adapt this design to greater water depths. These requirements can best be complied by a completely submersed system. To allow unattended long-term monitoring in a submarine environment, such a system has to be extremely durable. Therefore, we focussed on developing a mechanically and electrically as simple setup as possible, which has the additional advantage of low cost. The system consists of gas collector, sensor head and pressure housing for electronics and power supply. The collector is a plastic funnel, enclosed in a stainless-steel frame to add weight and stability. The whole unit is fixed to the sediment by nails or sediment screws. The sensor head is equipped with an "inverted tipping-bucket" sensor, which basically works like a turned upside-down rain gauge. It fills with the collected gas until full, then empties completely and starts again, which allows the calculation of the flow rate by container volume and frequency of the cycle. This sensor type is very robust due to a design nearly without moving parts and suitable for very low to medium flow rates. For higher flow rates different sensor heads using turbine wheels or pressure differences can be used. The pressure housing for this prototype is made of aluminium and contains a Hobo Pendant data logger with integrated battery supply. Since this setup is inexpensive, it can be deployed in numbers to cover larger areas. By addition of multi-channel data loggers, data transmission by acoustic modem or cable, relay stations on the seafloor or buoys etc. the infrastructure can be adapted to the environmental setting and financial budget. Prototype tests under laboratory conditions as well as field tests on natural submarine gas vents as an analogue to leaking storage sites have demonstrated the capabilities and robustness of the systems.

Water molecules in the nucleotide binding cleft of actin: effects on subunit conformation and implications for ATP hydrolysis.

PubMed

Saunders, Marissa G; Voth, Gregory A

2011-10-14

In the monomeric actin crystal structure, the positions of a highly organized network of waters are clearly visible within the active site. However, the recently proposed models of filamentous actin (F-actin) did not extend to including these waters. Since the water network is important for ATP hydrolysis, information about water position is critical to understanding the increased rate of catalysis upon filament formation. Here, we show that waters in the active site are essential for intersubdomain rotational flexibility and that they organize the active-site structure. Including the crystal structure waters during simulation setup allows us to observe distinct changes in the active-site structure upon the flattening of the actin subunit, as proposed in the Oda model for F-actin. We identify changes in both protein position and water position relative to the phosphate tail that suggest a mechanism for accelerating the rate of nucleotide hydrolysis in F-actin by stabilizing charge on the β-phosphate and by facilitating deprotonation of catalytic water. Copyright © 2011 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanabe, S; Utsunomiya, S; Abe, E

Purpose: To assess an accuracy of fiducial maker-based setup using ExacTrac (ExT-based setup) as compared with soft tissue-based setup using Cone-beam CT (CBCT-based setup) for patients with prostate cancer receiving intensity-modulated radiation therapy (IMRT) for the purpose of investigating whether ExT-based setup can be an alternative to CBCT-based setup. Methods: The setup accuracy was analyzed prospectively for 7 prostate cancer patients with implanted three fiducial markers received IMRT. All patients were treated after CBCT-based setup was performed and corresponding shifts were recorded. ExacTrac images were obtained before and after CBCT-based setup. The fiducial marker-based shifts were calculated based on thosemore » two images and recorded on the assumption that the setup correction was carried out by fiducial marker-based auto correction. Mean and standard deviation of absolute differences and the correlation between CBCT and ExT shifts were estimated. Results: A total of 178 image dataset were analyzed. On the differences between CBCT and ExT shifts, 133 (75%) of 178 image dataset resulted in smaller differences than 3 mm in all dimensions. Mean differences in the anterior-posterior (AP), superior-inferior (SI), and left-right (LR) dimensions were 1.8 ± 1.9 mm, 0.7 ± 1.9 mm, and 0.6 ± 0.8 mm, respectively. The percentages of shift agreements within ±3 mm were 76% for AP, 90% for SI, and 100% for LR. The Pearson coefficient of correlation for CBCT and ExT shifts were 0.80 for AP, 0.80 for SI, and 0.65 for LR. Conclusion: This work showed that the accuracy of ExT-based setup was correlated with that of CBCT-based setup, implying that ExT-based setup has a potential ability to be an alternative to CBCT-based setup. The further work is to specify the conditions that ExT-based setup can provide the accuracy comparable to CBCT-based setup.« less

A service evaluation of on-line image-guided radiotherapy to lower extremity sarcoma: Investigating the workload implications of a 3 mm action level for image assessment and correction prior to delivery.

PubMed

Taylor, C; Parker, J; Stratford, J; Warren, M

2018-05-01

Although all systematic and random positional setup errors can be corrected for in entirety during on-line image-guided radiotherapy, the use of a specified action level, below which no correction occurs, is also an option. The following service evaluation aimed to investigate the use of this 3 mm action level for on-line image assessment and correction (online, systematic set-up error and weekly evaluation) for lower extremity sarcoma, and understand the impact on imaging frequency and patient positioning error within one cancer centre. All patients were immobilised using a thermoplastic shell attached to a plastic base and an individual moulded footrest. A retrospective analysis of 30 patients was performed. Patient setup and correctional data derived from cone beam CT analysis was retrieved. The timing, frequency and magnitude of corrections were evaluated. The population systematic and random error was derived. 20% of patients had no systematic corrections over the duration of treatment, and 47% had one. The maximum number of systematic corrections per course of radiotherapy was 4, which occurred for 2 patients. 34% of episodes occurred within the first 5 fractions. All patients had at least one observed translational error during their treatment greater than 0.3 cm, and 80% of patients had at least one observed translational error during their treatment greater than 0.5 cm. The population systematic error was 0.14 cm, 0.10 cm, 0.14 cm and random error was 0.27 cm, 0.22 cm, 0.23 cm in the lateral, caudocranial and anteroposterial directions. The required Planning Target Volume margin for the study population was 0.55 cm, 0.41 cm and 0.50 cm in the lateral, caudocranial and anteroposterial directions. The 3 mm action level for image assessment and correction prior to delivery reduced the imaging burden and focussed intervention on patients that exhibited greater positional variability. This strategy could be an efficient deployment of departmental resources if full daily correction of positional setup error is not possible. Copyright © 2017. Published by Elsevier Ltd.

Optodynamic characterization of shock waves after laser-induced breakdown in water.

PubMed

Petkovsek, Rok; Mozina, Janez; Mocnik, Grisa

2005-05-30

Plasma and a cavitation bubble develop at the site of laser-induced breakdown in water. Their formation and the propagation of the shock wave were monitored by a beam-deflection probe and an arm-compensated interferometer. The interferometer part of the setup was used to determine the relative position of the laser-induced breakdown. The time-of-flight data from the breakdown site to the probe beam yielded the velocity, and from the velocity the shock-wave pressure amplitudes were calculated. Two regions were found where the pressure decays with different exponents, pointing to a strong attenuation mechanism in the initial phase of the shock-wave propagation.

A new method of measuring gravitational acceleration in an undergraduate laboratory program

NASA Astrophysics Data System (ADS)

Wang, Qiaochu; Wang, Chang; Xiao, Yunhuan; Schulte, Jurgen; Shi, Qingfan

2018-01-01

This paper presents a high accuracy method to measure gravitational acceleration in an undergraduate laboratory program. The experiment is based on water in a cylindrical vessel rotating about its vertical axis at a constant speed. The water surface forms a paraboloid whose focal length is related to rotational period and gravitational acceleration. This experimental setup avoids classical source errors in determining the local value of gravitational acceleration, so prevalent in the common simple pendulum and inclined plane experiments. The presented method combines multiple physics concepts such as kinematics, classical mechanics and geometric optics, offering the opportunity for lateral as well as project-based learning.

Water vapor and aerosol lidar measurements within an atmospheric instrumental super site to study the aerosols and the tropospheric trace gases in rome

NASA Astrophysics Data System (ADS)

Dionisi, D.; Iannarelli, A. M.; Scoccione, A.; Liberti, G. L.; Cacciani, M.; Argentini, S.; Baldini, L.; Barnaba, F.; Campanelli, M.; Casasanta, G.; Diémoz, H.; Di Liberto, L.; Gobbi, G. P.; Petenko, I.; Siani, A. M.; Von Bismarck, J.; Casadio, S.

2018-04-01

A joint instrumental Super Site, combining observation in urban ("Sapienza" University) and semi-rural (ESA-ESRIN and CNR-ISAC) environment, for atmospheric studies and satellites Cal/Val activities, has been set-up in the Rome area (Italy). Ground based active and passive remote sensing instruments located in both sites are operating in synergy, offering information for a wide range of atmospheric parameters. In this work, a comparison of aerosol and water vapor measurements derived by the Rayleigh-Mie-Raman (RMR) lidars, operating simultaneously in both experimental sites, is presented.

Plasma treatment of polyethylene tubes in continuous regime using surface dielectric barrier discharge with water electrodes

NASA Astrophysics Data System (ADS)

Galmiz, Oleksandr; Zemánek, Miroslav; Pavliňák, David; Černák, Mirko

2018-05-01

Combining the surface dielectric barrier discharges generated in contact with water based electrolytes, as the discharge electrodes, we have designed a new type of surface electric discharge, generating thin layers of plasma which propagate along the treated polymer surfaces. The technique was aimed to achieve uniform atmospheric pressure plasma treatment of polymeric tubes and other hollow bodies. The results presented in this work show the possibility of such system to treat outer surface of polymer materials in a continuous mode. The technical details of experimental setup are discussed as well as results of treatment of polyethylene tubes are shown.

Remote sensing reflectance simulation of coastal optical complex water in the East China Sea

NASA Astrophysics Data System (ADS)

He, Shuo; Lou, Xiulin; Zhang, Huaguo; Zheng, Gang

2018-02-01

In this work, remote sensing reflectance (Rrs) spectra of the Zhejiang coastal water in the East China Sea (ECS) were simulated by using the Hydrolight software with field data as input parameters. The seawater along the Zhejiang coast is typical Case II water with complex optical properties. A field observation was conducted in the Zhejiang coastal region in late May of 2016, and the concentration of ocean color constituents (pigment, SPM and CDOM), IOPs (absorption and backscattering coefficients) and Rrs were measured at 24 stations of 3 sections covering the turbid to clear inshore coastal waters. Referring to these ocean color field data, an ocean color model suitable for the Zhejiang coastal water was setup and applied in the Hydrolight. A set of 11 remote sensing reflectance spectra above water surface were modeled and calculated. Then, the simulated spectra were compared with the filed measurements. Finally, the spectral shape and characteristics of the remote sensing reflectance spectra were analyzed and discussed.

PILOT-SCALE EVALUATION OF ENGINEERED BARIER SYSTEMS FOR THE YUCCA MOUNTAIN PROJECT

DOE Office of Scientific and Technical Information (OSTI.GOV)

S.W. Webb; J.T. George; R.E. Finley

This paper describes two quarter-scale experiments (1.4 m diameter) and associated numerical analyses on granular backfill engineered barrier systems in support of the Yucca Mountain Project for the potential repository. The two configurations include a sloped capillary barrier and a plain backfill. The tests involve application of dyed water as a constant line infiltration source along the top of the test set-up, monitoring water movement through the test, and measuring water exiting the experiments. A complete water balance estimate is made for each test, and observed water movement is compared with (1) detailed numerical analyses conducted using the TOUGH2 codemore » for unsaturated flow in porous media and (2) posttest observations. The results of the testing and analyses show that for the injection rates and configuration applied, the capillary barrier design diverts a significant amount of all injected water and the TOUGH2 pretest predictions show qualitative and quantitative agreement with the experimental data.« less

High-accuracy measurement of low-water-content in liquid using NIR spectral absorption method

NASA Astrophysics Data System (ADS)

Peng, Bao-Jin; Wan, Xu; Jin, Hong-Zhen; Zhao, Yong; Mao, He-Fa

2005-01-01

Water content measurement technologies are very important for quality inspection of food, medicine products, chemical products and many other industry fields. In recent years, requests for accurate low-water-content measurement in liquid are more and more exigent, and great interests have been shown from the research and experimental work. With the development and advancement of modern production and control technologies, more accurate water content technology is needed. In this paper, a novel experimental setup based on near-infrared (NIR) spectral technology and fiber-optic sensor (OFS) is presented. It has a good measurement accuracy about -/+ 0.01%, which is better, to our knowledge, than most other methods published until now. It has a high measurement resolution of 0.001% in the measurement range from zero to 0.05% for water-in-alcohol measurement, and the water-in-oil measurement is carried out as well. In addition, the advantages of this method also include pollution-free to the measured liquid, fast measurement and so on.

Fiber Optic Sensor for Real-Time Sensing of Silica Scale Formation in Geothermal Water.

PubMed

Okazaki, Takuya; Orii, Tatsuya; Ueda, Akira; Ozawa, Akiko; Kuramitz, Hideki

2017-06-13

We present a novel fiber optic sensor for real-time sensing of silica scale formation in geothermal water. The sensor is fabricated by removing the cladding of a multimode fiber to expose the core to detect the scale-formation-induced refractive index change. A simple experimental setup was constructed to measure the transmittance response using white light as a source and a spectroscopy detector. A field test was performed on geothermal water containing 980 mg/L dissolved silica at 93 °C in Sumikawa Geothermal Power Plant, Japan. The transmittance response of the fiber sensor decreased due to the formation of silica scale on the fiber core from geothermal water. An application of this sensor in the evaluation of scale inhibitors was demonstrated. In geothermal water containing a pH modifier, the change of transmittance response decreased with pH decrease. The effectiveness of a polyelectrolyte inhibitor in prevention of silica scale formation was easily detectable using the fiber sensor in geothermal water.

VAPOR PRESSURE ISOTOPE EFFECTS IN THE MEASUREMENT OF ENVIRONMENTAL TRITIUM SAMPLES.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhne, W.

2012-12-03

Standard procedures for the measurement of tritium in water samples often require distillation of an appropriate sample aliquot. This distillation process may result in a fractionation of tritiated water and regular light water due to the vapor pressure isotope effect, introducing either a bias or an additional contribution to the total tritium measurement uncertainty. The magnitude of the vapor pressure isotope effect is characterized as functions of the amount of water distilled from the sample aliquot and the heat settings for the distillation process. The tritium concentration in the distillate is higher than the tritium concentration in the sample earlymore » in the distillation process, it then sharply decreases due to the vapor pressure isotope effect and becomes lower than the tritium concentration in the sample, until the high tritium concentration retained in the boiling flask is evaporated at the end of the process. At that time, the tritium concentration in the distillate again overestimates the sample tritium concentration. The vapor pressure isotope effect is more pronounced the slower the evaporation and distillation process is conducted; a lower heat setting during the evaporation of the sample results in a larger bias in the tritium measurement. The experimental setup used and the fact that the current study allowed for an investigation of the relative change in vapor pressure isotope effect in the course of the distillation process distinguish it from and extend previously published measurements. The separation factor as a quantitative measure of the vapor pressure isotope effect is found to assume values of 1.034 {+-} 0.033, 1.052 {+-} 0.025, and 1.066 {+-} 0.037, depending on the vigor of the boiling process during distillation of the sample. A lower heat setting in the experimental setup, and therefore a less vigorous boiling process, results in a larger value for the separation factor. For a tritium measurement in water samples, this implies that the tritium concentration could be underestimated by 3 - 6%.« less

A new optical ice particle counter at LACIS

NASA Astrophysics Data System (ADS)

Bieligk, Henner; Voelker, Georg Sebastian; Clauss, Tina; Grundmann, Marius; Stratmann, Frank

2014-05-01

Clouds play an important role within the climate system, especially for the radiative energy budget of the earth. The radiative properties of a cloud depend strongly on the fractions of ice crystals and water droplets, their size distributions, and the ice crystal shapes within the particular cloud. One option to gain this kind of information is using optical particle counters. A new optical particle counter is developed for laboratory work and is based on the concept of the Thermostabilized Optical Particle Spectrometer for the Detection of Ice Particles (TOPS-Ice, Clauss et al., 2013). TOPS-Ice uses linearly polarized green laser light and the depolarization of the scattered light at a scattering angle of 42.5° to discriminate between liquid water droplets and ice crystals in the lower μm range. However, the measurements are usually limited to ice fractions in the order of 1%. To improve the determination of the ice fraction, several modifications of the original setup are implemented including an additional detection system at another scattering angle. The new scattering angle is optimized for least interference between the droplet and ice signals. This is achieved by finding the angle with the maximum difference in scattered intensity of water droplets compared to ice crystals with the same volume equivalent diameter. The suitable scattering angle of 100° for linearly polarized light was chosen based on calculations using T-Matrix method, Lorenz-Mie theory, Müller matrices and distribution theory. The new optical setup is designed to run in combination with a laminar flow tube, the so-called Leipzig Aerosol Cloud Interaction Simulator (LACIS, Stratmann et al., 2004; Hartmann et al., 2011). Using LACIS and its precisely controlled thermodynamic conditions, we are able to form small water droplets and ice crystals which will then be detected, classified and sized by our new optical device. This setup is planned to be tested in ice measurements including Snomax® and several dusts (e.g. illite, kaolinite, ATD) as ice nuclei which all show different behaviors in ice formation. Furthermore, a detailed comparison of both instruments TOPS-Ice and the new setup is planned. This project is part of the Leipzig Graduate School on Clouds, Aerosols and Radiation and is partly supported by the German Research Foundation (DFG project WE 4722/1-1) within the DFG Research Unit FOR 1525 INUIT. Clauss, T., Kiselev, A., Hartmann, S., Augustin, S., Pfeifer, S., Niedermeier, D., Wex, H., and Stratmann, F, 2013, Application of linear polarized light for the discrimination of frozen and liquid droplets in ice nucleation experiments, Atmos. Meas. Tech., 6, 1041-1052. Hartmann, S., Niedermeier, D., Voigtländer, J., Clauss, T., Shaw, R. A., Kiselev, A., and Stratmann, F., 2011, Homogeneous and heterogeneous ice nucleation at LACIS: operating principle and theoretical studies, Atmos. Chem. Phys., 11, 1753-1767. Stratmann, F., Kiselev, A., Wurzler, S., Wendisch, M., Heintzenberg, J., Charlson, R. J., Diehl, K., Wex, H., and Schmidt, S., 2004, Laboratory Studies and Numerical Simulations of Cloud Droplet Formation under Realistic Supersaturation Conditions, J. Atmos. Oceanic. Technol., 21, 876-887.

Greenhouse gas emissions from short-rotation forestry on a drained and rewetted fen

NASA Astrophysics Data System (ADS)

Schlaipfer, Martina; Fuertes Sánchez, Alicia; Drösler, Matthias

2017-04-01

More than 95 % of German peatlands have been drained, primarily for agricultural and forestry use. They constitute a significant source of greenhouse gases (GHG) with emissions of approximately 47 million tons per year. Propelled by the German energy turnaround farmers have increasingly converted their cropland to short rotation forestry (SRF), amongst them some who are cultivating drained peatland. In this study GHG emissions from alder and poplar short rotation plantations with differing groundwater levels near Rosenheim, Bavaria, were monitored over the course of three-and-a-half years. Moreover, the effect of ploughing for SRF establishment was investigated as well. Understorey GHG fluxes were measured using closed-chamber approaches. Gas samples were enclosed in vials every second week and analysed for their CH4 and N2O concentrations by gas chromatography at a laboratory. On-site measurements of CO2 fluxes were carried out over the course of a day every three to four weeks with a dynamic closed-chamber technique. Allometric methods were employed to estimate carbon sequestration into trees. Sheet piling was installed around a set of measurement sites in December 2014 to accentuate the difference between the sites with high and low water tables. As a result the water level around those sites rose from an average of -36.1 ± 6.1 cm in 2013 and 2014 to -20.8 ± 3.7 cm in 2015. The water table outside the sheet piling showed values of -61.8 ± 5.7 cm and -72.1 ± 6.2 cm in those years, respectively. First results suggest a limited effect of ploughing for SRF establishment on understorey GHG emissions. However, there seems to be a distinct impact on tree productivity. CO2 fluxes in the understorey seem to be strongly influenced by water table, but also land management (mulching of understorey vegetation to reduce weed competition for trees during the first year and for pest control in subsequent years) and shading of the understorey vegetation by trees. There is a clear correlation between CH4 emissions and water table, with higher water levels causing higher emissions. So far it has not been possible to establish any such relationship for N2O emissions as they varied greatly throughout all experimental setups in 2014, and were relatively high in general in 2015. It is expected that the cool and rainy summer of 2016 with its accompanying high water tables inside the sheet piling (-6.8 ± 3.2 cm) led to a reduction of the climatic relevance of the wetter sites.

RF magnetized ring-shaped plasma for target utilization obtained with circular magnet monopole arrangement

NASA Astrophysics Data System (ADS)

Amzad Hossain, Md.; Ohtsu, Yasunori

2018-01-01

We proposed a new setup for generating outer ring-shaped radio frequency (RF) magnetized plasma near the chamber wall using monopole magnet setups. Three monopole magnet setups with (a) R = 5 mm, (b) R = 20 mm, and (c) R = 35 mm were investigated, where R is the gap between the magnets in consecutive circles. The distributions of the two dimensional magnetic flux lines, the absolute value of the horizontal magnetic flux density, and the discharge voltage were investigated for the proposed setups to produce outer ring-shaped plasma. A highly luminous ring-shaped plasma was observed for the setup (a), whereas multi-ring discharges were observed for the setups (b) and (c). It was found that the electron temperature decreases with increasing gas pressure for all cases. The electron temperatures were 2.42, 1.71, and 1.15 eV at an Ar gas pressure of 4 Pa for setups (a), (b), and (c), respectively. The plasma density was approximately the same for setups (b) and (c) at all gas pressures. The highest plasma densities were 6.26 × 1015, 1.06 × 1016, and 1.11 × 1016 m-3 at 5 Pa for setups (a), (b), and (c), respectively. It was found that the electron mean free path was 41.4, 63.17, and 84.66 mm at an Ar gas pressure of 5 Pa for setups (a), (b), and (c), respectively. The electron neutral collision frequency for setup (a) was higher than those for setups (b) and (c) at a constant RF power of 40 W and an axial distance of z = 13 mm from the target surface. The radial profile of the ion saturation current for setup (b) was more uniform than those for setups (a) and (c).

Annual budget of Gd and related Rare Earth Elements in a river basin heavily disturbed by anthropogenic activities.

NASA Astrophysics Data System (ADS)

Hissler, Christophe; Stille, Peter; Guignard, Cédric; François Iffly, Jean; Pfister, Laurent

2014-05-01

The real environmental impact of micropollutants in river systems can be difficult to assess, essentially due to uncertainties in the estimation of the relative significance of both anthropogenic and natural sources. The natural geochemical background is characterized by important variations at global, regional or local scales. Moreover, elements currently considered to be undisturbed by human activities and used as tracers of continental crust derived material have become more and more involved in industrial or agricultural processes. The global production of lanthanides (REE), used in industry, medicine and agriculture, for instance, has increased exponentially from a few tons in 1950 to projected 185 kt in 2015. Consequently, these new anthropogenic contributions impact the natural cycle of the REE. Gd and related REE are now worldwide recognized as emergent micropollutants in river systems. Nevertheless, there is still a gap concerning their temporal dynamics in rivers and especially the quantification of both the anthropogenic and natural contributions in surface water. The acquisition of such quantitative information is of primordial interest because elements from both origins may present different bioavailability and toxicity levels. Working at the river basin scale allows for quantifying micropollutant fluxes. For this reason, we monitored water quality and discharge of the Alzette River (Luxembourg, Europe) over two complete hydrological cycles (2010-2013). The substantial contamination, is principally due to the steel industry in the basin, which has been active from 1875 until now, and to the related increase of urban areas. The particulate and dissolved fractions of river water were monitored using a multitracer approach (standard parameters for water quality including REE concentrations, Pb, Sr, Nd radiogenic isotopes) with two sampling setups (bi-weekly and flood event based sampling). This extensive sampling design allowed quantifying the annual budget of the REE in the particulate and dissolved fractions of the river water and the waste water treatment plant effluents. Enrichments in Gd have been observed for the dissolved fraction of the water during low water levels. This enrichment has not been detected in the surrounding soils of the basin and can be related to the effluents of the waste water treatment plants, which control the REE chemistry of the dissolved fraction during the low water period. When flood events occur, the Gd anomaly progressively disappears and gives way to the chemical signature of the basin soils. The REE and intense hydrological monitoring we performed at the same time allowed for the annual quantification of the anthropogenic vs. natural REE fluxes in the river water of this heavily polluted basin.

Intraclass Correlation Coefficients in Hierarchical Design Studies with Discrete Response Variables: A Note on a Direct Interval Estimation Procedure

ERIC Educational Resources Information Center

Raykov, Tenko; Marcoulides, George A.

2015-01-01

A latent variable modeling procedure that can be used to evaluate intraclass correlation coefficients in two-level settings with discrete response variables is discussed. The approach is readily applied when the purpose is to furnish confidence intervals at prespecified confidence levels for these coefficients in setups with binary or ordinal…

PsiQuaSP-A library for efficient computation of symmetric open quantum systems.

PubMed

Gegg, Michael; Richter, Marten

2017-11-24

In a recent publication we showed that permutation symmetry reduces the numerical complexity of Lindblad quantum master equations for identical multi-level systems from exponential to polynomial scaling. This is important for open system dynamics including realistic system bath interactions and dephasing in, for instance, the Dicke model, multi-Λ system setups etc. Here we present an object-oriented C++ library that allows to setup and solve arbitrary quantum optical Lindblad master equations, especially those that are permutationally symmetric in the multi-level systems. PsiQuaSP (Permutation symmetry for identical Quantum Systems Package) uses the PETSc package for sparse linear algebra methods and differential equations as basis. The aim of PsiQuaSP is to provide flexible, storage efficient and scalable code while being as user friendly as possible. It is easily applied to many quantum optical or quantum information systems with more than one multi-level system. We first review the basics of the permutation symmetry for multi-level systems in quantum master equations. The application of PsiQuaSP to quantum dynamical problems is illustrated with several typical, simple examples of open quantum optical systems.

Eddy Covariance measurements of stable isotopes (δD and δ18O) in water vapor

NASA Astrophysics Data System (ADS)

Braden-Behrens, J.; Knohl, A.

2016-12-01

Stable isotopes are a promising tool to enhance our understanding of ecosystem gas exchanges. Studying 18O and 2H (D) in water vapour (H2Ov) can e.g. help partitioning evapotranspiration into its components. With recent developments in laser spectroscopy direct Eddy Covariance (EC) measurements to investigate fluxes of stable isotopologues became feasible. But so far only very few case studies applying the EC method to stable isotopes in water vapor have been carried out worldwide At our micrometeorological EC tower in a managed beech forest in Thuringia, Germany, we continuously measure fluxes of water vapor isotopologues using EC since autumn 2015. The set-up is based on an off-axis cavity output water vapor isotope analyzer (WVIA, Los Gatos Research. Inc, USA) that measures the water vapour concentration and its isotopic composition (δD and δ18O). The instrument is optimized for high flow rates (app. 4slpm) to generate high frequent (2Hz) measurements. The HF-optimized WVIA showed sufficient precision with a minimal Allan Deviation of 0.023 ‰ for δD and 0.02 ‰ for δ18O for averaging periods of app. 700 s and 400 s resp. The instrument is calibrated hourly using a high-flow optimized version of the water vapor isotope standard source (WVISS, Los Gatos Research. Inc, USA) that provides water vapor with known isotopic composition for a large range of different concentrations. Our calibration scheme includes a near continuous concentration range calibration instead of a simple 2 or 3-point calibration to face the analyzers large concentration dependency within a range of app. 6 000 to 16 000 ppm in winter and app. 8 000 to 23 000 ppm in summer. We evaluate the calibration approach, present specific aspects of the set-up such as the HF optimization and compare the measured and averaged spectra and cospectra of the isotopologue analyzer with those of the longterm EC installation (using a LI-6262 as well as a LI-7200 infrared gas analyzer at 10 Hz). Furthermore, we show results for the isotopologue fluxes before and after leaf unfolding in spring/summer 2016. This novel instrument for EC measurements of water vapor isotopologues provides a new exciting opportunity for studying the hydrological cycle in long-term observation networks like Ameriflux and ICOS.

Run 16 Tandem gold performance in the injectors and possible improvement with AGS type 6:3:1 bunch merge in the Booster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zeno, Keith

2016-10-21

During Run 16 the Tandem was used as the Gold pre-injector for a brief time so that RHIC could continue running while EBIS was down for repairs. Given the time constraints, the setup was largely derived from the EBIS Au setup. The EBIS Au setup used a 4:2:1 bunch merge in the Booster and a 12:6:2 bunch merge in the AGS.1 This note will describe the Tandem Au setup and compare it to that used for EBIS Au. The bunch merge in the Booster for Tandem Au did not work well, and it seems likely that the performance would’ve beenmore » significantly better if it did. An AGS type 6:3:1 merge in the Booster is described which might improve matters.2 Somewhat speculative estimates for the AGS bunch intensity and emittance, if that merge were successful in reducing the Booster extraction emittance to EBIS Au levels, are also given for several potential setups. Using 6 Booster loads from the Tandem, the AGS bunch intensity at extraction reached about 2.5e9 ions with a longitudinal emittance (ε) of about 0.59 eV·s/n.3 Using 12 Booster loads from EBIS, the peak bunch intensity and ε was about 3.1e9 ions and 0.75 eV·s/n, respectively. A 6.4 sec supercycle was used for both at the time, but the Tandem Au supercycle (barring any potential issues with Tandem) could probably have been reduced to about 4.6 sec.« less

Analysis of Tide and Offshore Storm-Induced Water Table Fluctuations for Structural Characterization of a Coastal Island Aquifer

NASA Astrophysics Data System (ADS)

Trglavcnik, Victoria; Morrow, Dean; Weber, Kela P.; Li, Ling; Robinson, Clare E.

2018-04-01

Analysis of water table fluctuations can provide important insight into the hydraulic properties and structure of a coastal aquifer system including the connectivity between the aquifer and ocean. This study presents an improved approach for characterizing a permeable heterogeneous coastal aquifer system through analysis of the propagation of the tidal signal, as well as offshore storm pulse signals through a coastal aquifer. Offshore storms produce high wave activity, but are not necessarily linked to significant onshore precipitation. In this study, we focused on offshore storm events during which no onshore precipitation occurred. Extensive groundwater level data collected on a sand barrier island (Sable Island, NS, Canada) show nonuniform discontinuous propagation of the tide and offshore storm pulse signals through the aquifer with isolated inland areas showing enhanced response to both oceanic forcing signals. Propagation analysis suggests that isolated inland water table fluctuations may be caused by localized leakage from a confined aquifer that is connected to the ocean offshore but within the wave setup zone. Two-dimensional groundwater flow simulations were conducted to test the leaky confined-unconfined aquifer conceptualization and to identify the effect of key parameters on tidal signal propagation in leaky confined-unconfined coastal aquifers. This study illustrates that analysis of offshore storm signal propagation, in addition to tidal signal propagation, provides a valuable and low resource approach for large-scale characterization of permeable heterogeneous coastal aquifers. Such an approach is needed for the effective management of coastal environments where water resources are threatened by human activities and the changing climate.

Cryogenic actuator testing for the SAFARI ground calibration setup

NASA Astrophysics Data System (ADS)

de Jonge, C.; Eggens, M.; Nieuwenhuizen, A. C. T.; Detrain, A.; Smit, H.; Dieleman, P.

2012-09-01

For the on-ground calibration setup of the SAFARI instrument cryogenic mechanisms are being developed at SRON Netherlands Institute for Space Research, including a filter wheel, XYZ-scanner and a flipmirror mechanism. Due to the extremely low background radiation requirement of the SAFARI instrument, all of these mechanisms will have to perform their work at 4.5 Kelvin and low-dissipative cryogenic actuators are required to drive these mechanisms. In this paper, the performance of stepper motors, piezoelectric actuators and brushless DC-motors as cryogenic actuators are compared. We tested stepper motor mechanical performance and electrical dissipation at 4K. The actuator requirements, test setup and test results are presented. Furthermore, design considerations and early performance tests of the flipmirror mechanism are discussed. This flipmirror features a 102 x 72 mm aluminum mirror that can be rotated 45°. A Phytron stepper motor with reduction gearbox has been chosen to drive the flipmirror. Testing showed that this motor has a dissipation of 49mW at 4K with a torque of 60Nmm at 100rpm. Thermal modeling of the flipmirror mechanism predicts that with proper thermal strapping the peak temperature of the flipmirror after a single action will be within the background level requirements of the SAFARI instrument. Early tests confirm this result. For low-duty cycle operations commercial stepper motors appear suitable as actuators for test equipment in the SAFARI on ground calibration setup.

A Novel Computer-Based Set-Up to Study Movement Coordination in Human Ensembles

PubMed Central

Alderisio, Francesco; Lombardi, Maria; Fiore, Gianfranco; di Bernardo, Mario

2017-01-01

Existing experimental works on movement coordination in human ensembles mostly investigate situations where each subject is connected to all the others through direct visual and auditory coupling, so that unavoidable social interaction affects their coordination level. Here, we present a novel computer-based set-up to study movement coordination in human groups so as to minimize the influence of social interaction among participants and implement different visual pairings between them. In so doing, players can only take into consideration the motion of a designated subset of the others. This allows the evaluation of the exclusive effects on coordination of the structure of interconnections among the players in the group and their own dynamics. In addition, our set-up enables the deployment of virtual computer players to investigate dyadic interaction between a human and a virtual agent, as well as group synchronization in mixed teams of human and virtual agents. We show how this novel set-up can be employed to study coordination both in dyads and in groups over different structures of interconnections, in the presence as well as in the absence of virtual agents acting as followers or leaders. Finally, in order to illustrate the capabilities of the architecture, we describe some preliminary results. The platform is available to any researcher who wishes to unfold the mechanisms underlying group synchronization in human ensembles and shed light on its socio-psychological aspects. PMID:28649217

Evaluation of the Hepato and Nephron-Protective Effect of a Polyherbal Mixture using Wistar Albino Rats

PubMed Central

Adebesin, Olumide Adedapo; Okpuzor, Joy

2014-01-01

Aim: A polyherbal formulation prepared from a mixture of leaves of Gongronema latifolia, Ocimum gratissimum and Vernonia amygdalina (GOV) was evaluated for hepato-nephro protective properties against acetaminophen-induced toxicity in Wistar albino rats. Materials and Methods: Normal Wistar albino rats were orally treated with different doses of GOV extract (2, 4 and 8 g/kg b. wt), distilled water and some standard hepatoprotective drugs such as Liv 52 and silymarin for 14 days. However, a day prior to the 14th day, 3 g/kg body weight dose of Acetaminophen (APAP) was administered p.o. 1h before GOV and the standard drugs to induce hepatic and renal damage. The normal control was setup which received only distilled water. The serum levels of liver marker enzymes, biochemical analytes, antioxidant enzymes and hematological parameters were monitored. Results: The results showed that pretreatment of experimental animals with a different doses of the polyherbal formulation dose dependently caused a significant (p≤0.05) increase in the levels of most of the measured hematological parameters but significantly (p≤0.05) reduced the levels of MCV and monocytes when compared to the APAP induced toxin control group. Rats pretreated with GOV exhibited significant (p < 0.05) increase in serum levels of ALP, ALT, AST, GGT, LDH, Cholesterol, Triglycerides, Urea and a subsequent decrease in Albumin, Creatine and Total protein when compared to the normal rats. This trend in enzyme and biochemical analytes levels were significantly (p < 0.05) reversed when compared to toxin control group. GOV significantly (p < 0.05) and dose dependently increased the serum, kidney and hepatic CAT, GPx, GSH, GST, SOD and total protein activity in APAP induced damage in rats compared to the toxin control groups. Conclusion: The data from this study suggest that the polyherbal formulation possess hepato and nephron-protective potential against acetaminophen induced hepatotoxicity in rats, thus providing scientific rationale for its use in traditional medicine for the treatment of liver diseases. PMID:25121002

Measurements of complex impedance in microwave high power systems with a new bluetooth integrated circuit.

PubMed

Roussy, Georges; Dichtel, Bernard; Chaabane, Haykel

2003-01-01

By using a new integrated circuit, which is marketed for bluetooth applications, it is possible to simplify the method of measuring the complex impedance, complex reflection coefficient and complex transmission coefficient in an industrial microwave setup. The Analog Devices circuit AD 8302, which measures gain and phase up to 2.7 GHz, operates with variable level input signals and is less sensitive to both amplitude and frequency fluctuations of the industrial magnetrons than are mixers and AM crystal detectors. Therefore, accurate gain and phase measurements can be performed with low stability generators. A mechanical setup with an AD 8302 is described; the calibration procedure and its performance are presented.

Global analysis of a renewable micro hydro power generation plant

NASA Astrophysics Data System (ADS)

Rahman, Md. Shad; Nabil, Imtiaz Muhammed; Alam, M. Mahbubul

2017-12-01

Hydroelectric power or Hydropower means the power generated by the help of flowing water with force. It is one the best source of renewable energy in the world. Water evaporates from the earth's surface, forms clouds, precipitates back to earth, and flows toward the ocean. Hydropower is considered a renewable energy resource because it uses the earth's water cycle to generate electricity. As far as Global is concerned, only a small fraction of electricity is generated by hydro-power. The aim of our analysis is to demonstrate and observe the hydropower of the Globe in micro-scale by our experimental setup which is completely new in concept. This paper consists of all the Global and National Scenario of Hydropower. And how we can more emphasize the generation of Hydroelectric power worldwide.

Dosimetric challenges of small animal irradiation with a commercial X-ray unit.

PubMed

Kuess, Peter; Bozsaky, Eva; Hopfgartner, Johannes; Seifritz, Gerhard; Dörr, Wolfgang; Georg, Dietmar

2014-12-01

A commercial X-ray unit was recently installed at the Medical University Vienna for partial and whole body irradiation of small experimental animals. For 200 kV X-rays the dose deviations with respect to the reference dose measured in the geometrical center of the potential available field size was investigated for various experimental setup plates used for mouse irradiations. Furthermore, the HVL was measured in mm Al and mm Cu at 200 kV for two types of filtration. Three different setup constructions for small animal irradiation were dosimetrically characterized, covering field sizes from 9×20 mm2 to 210×200 mm2. Different types of detectors were investigated. Additionally LiF:MG,Ti TLD chips were used for mouse in-vivo dosimetry. The use of an additional 0.5 mm Cu filter reduced the deviation of the dose between each irradiation position on the setup plates. Multiple animals were irradiated at the same time using an individual setup plate for each experimental purpose. The dose deviations of each irradiation position to the center was measured to be ±4% or better. The depth dose curve measured in a solid water phantom was more pronounced for smaller field sizes. The comparison between estimated dose and measured dose in a PMMA phantom regarding the dose decline yielded in a difference of 3.9% at 20 mm depth. In-vivo measurements in a mouse snouts irradiation model confirmed the reference dosimetry, accomplished in PMMA phantoms, in terms of administered dose and deviation within different points of measurement. The outlined experiments dealt with a wide variety of dosimetric challenges during the installation of a new X-ray unit in the laboratory. The depth dose profiles measured for different field sizes were in good agreement with literature data. Different field sizes and spatial arrangement of the animals (depending on each purpose) provide additional challenges for the dosimetric measurements. Thorough dosimetric commissioning has to be performed before a new experimental setup is approved for biological experiments. Copyright © 2014. Published by Elsevier GmbH.

SU-E-T-662: Quick and Efficient Daily QA for Compact PBS Proton Therapy Machine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, B; Syh, J; Ding, X

2015-06-15

Purpose: As proton therapy machines become widespread the need for a quick simple routine daily QA like that for linear accelerators becomes more important. Willis-Knighton has developed an accurate and efficient daily QA that can be performed in 15 minutes. Methods: A holder for a 2D ionization chamber array (MatriXX PT) was created that is indexed to the couch to allow for quick setup, lasers accuracy with respect to beam isocenter, and couch reproducibility. Image position/reposition was performed to check Isocentricity accuracy by placing BBs on the MatriXX. The couch coordinates are compared to that of commissioning. Laser positions weremore » confirmed with the MatriXX isocenter. After IGRT, three beams were separately delivered according to setup. For the first beam, range shifter was inserted and dose at R90, field size, flatness and symmetry in X and Y direction was measured. R90 was used so any minor changes in the range shifter can be detected. For the open beam, dose at center of SOBP, flatness and symmetry in X and Y direction was measured. Field size was measured in ±X and ±Y direction at FWHM. This is measured so any variation in spot size will be detected. For the third beam additional solid water was added and dose at R50 was measured so that any variation in beam energy will be detected. Basic mechanical and safety checks were also performed. Results: Medical physicists were able to complete the daily QA and reduce the time by half to two-third from initial daily QA procedure. All the values measured were within tolerance of that of the baseline which was established from water tank and initial MatriXX measurements. Conclusion: The change in daily QA procedure resulted in quick and easy setup and was able to measure all the basic functionality of the proton therapy PBS.« less

ASD FieldSpec Calibration Setup and Techniques

NASA Technical Reports Server (NTRS)

Olive, Dan

2001-01-01

This paper describes the Analytical Spectral Devices (ASD) Fieldspec Calibration Setup and Techniques. The topics include: 1) ASD Fieldspec FR Spectroradiometer; 2) Components of Calibration; 3) Equipment list; 4) Spectral Setup; 5) Spectral Calibration; 6) Radiometric and Linearity Setup; 7) Radiometric setup; 8) Datadets Required; 9) Data files; and 10) Field of View Measurement. This paper is in viewgraph form.

Barnes Maze Procedure for Spatial Learning and Memory in Mice.

PubMed

Pitts, Matthew W

2018-03-05

The Barnes maze is a dry-land based rodent behavioral paradigm for assessing spatial learning and memory that was originally developed by its namesake, Carol Barnes. It represents a well-established alternative to the more popular Morris Water maze and offers the advantage of being free from the potentially confounding influence of swimming behavior. Herein, the Barnes maze experimental setup and corresponding procedures for testing and analysis in mice are described in detail.

Reduction of erosion by protein-containing toothpastes.

PubMed

Jager, D H J; Vissink, A; Timmer, C J; Bronkhorst, E; Vieira, A M; Huysmans, M C D N J M

2013-01-01

To assess the effect of protein-containing toothpastes on the progression of dental erosion in situ (with pellicle) and in vitro (without pellicle). A combined split-mouth (extraoral water or toothpaste brushing) and crossover (type of toothpaste) setup was used. Two protein-containing (high/low concentrations of colostrum) and one nonprotein (placebo) toothpaste were investigated. Sixteen volunteers wore intraoral appliances containing 2 human enamel samples on 3 afternoons for pellicle growth during 90 min. One enamel sample was brushed for 5 s with one of the three toothpastes and subsequently exposed to a slurry of the corresponding toothpaste for 2 min. The other sample was exposed to water. Both samples were subsequently exposed to citric acid (extraorally). Loss of calcium and inorganic phosphate were determined. The same sequence of exposures was applied to 16 enamel samples in an in vitro setup without pellicle. With the in situ-formed pellicle, all toothpastes significantly reduced calcium loss compared to water brushing, although no significant differences were found among toothpastes (p = 0.073). For the loss of phosphate, a significant reduction could be found with the use of the high-protein toothpaste compared to the nonprotein toothpaste. Overall there were only slight differences between the toothpastes. Toothpaste effects were less clear in the in vitro experiment. The addition of proteins to toothpaste shows some promise for the prevention of erosion. Further research is needed to investigate the performance of the protein-containing toothpastes in longer in situ studies with regard to erosive wear. Copyright © 2012 S. Karger AG, Basel.

Dynamic groundwater flows and geochemistry in a sandy nearshore aquifer over a wave event

NASA Astrophysics Data System (ADS)

Malott, Spencer; O'Carroll, Denis M.; Robinson, Clare E.

2016-07-01

Dynamic coastal forcing influences the transport of pollutants in nearshore aquifers and their ultimate flux to coastal waters. In this study, field data are presented that show, for the first time, the influence of a period of intensified wave conditions (wave event) on nearshore groundwater flows and geochemistry in a sandy beach. Field measurements at a freshwater beach allow wave effects to be quantified without other complex forcing that are present along marine shorelines (e.g., tides). Pressure transducer data obtained over an isolated wave event reveal the development of transient groundwater flow recirculations. The groundwater flows were simulated in FEFLOW using a phase-averaged wave setup approach to represent waves acting on the sediment-water interface. Comparison of measured and simulated data indicates that consideration of wave setup alone is able to adequately capture wave-induced perturbations in groundwater flows. While prior studies have shown sharp pH and redox spatial zonations in nearshore aquifers, this study reveals rapid temporal variations in conductivity, pH, and redox (ORP) in shallow sediments (up to 0.5 m depth) in response to varying wave conditions. Comparison of head gradients with calculated conductivity and pH mixing ratios indicates the controlling effect of the wave-induced water exchange and flows in driving the observed geochemical dynamics. While we are not able to conclusively determine the extent to which temporal variations are caused by conservative mixing versus reactive processes, the pH and ORP variations observed will have significant implications for the fate of reactive pollutants discharging through sandy nearshore aquifers.

Plasmon-induced artificial photosynthesis

PubMed Central

Ueno, Kosei; Oshikiri, Tomoya; Shi, Xu; Zhong, Yuqing; Misawa, Hiroaki

2015-01-01

We have successfully developed a plasmon-induced artificial photosynthesis system that uses a gold nanoparticle-loaded oxide semiconductor electrode to produce useful chemical energy as hydrogen and ammonia. The most important feature of this system is that both sides of a strontium titanate single-crystal substrate are used without an electrochemical apparatus. Plasmon-induced water splitting occurred even with a minimum chemical bias of 0.23 V owing to the plasmonic effects based on the efficient oxidation of water and the use of platinum as a co-catalyst for reduction. Photocurrent measurements were performed to determine the electron transfer between the gold nanoparticles and the oxide semiconductor. The efficiency of water oxidation was determined through spectroelectrochemical experiments aimed at elucidating the electron density in the gold nanoparticles. A set-up similar to the water-splitting system was used to synthesize ammonia via nitrogen fixation using ruthenium instead of platinum as a co-catalyst. PMID:26052419

[Measurement and analysis of micropore aeration system's oxygenating ability under operation condition in waste water treatment plant].

PubMed

Wu, Yuan-Yuan; Zhou, Xiao-Hong; Shi, Han-Chang; Qiu, Yong

2013-01-01

Using the aeration pool in the fourth-stage at Wuxi Lucun Waste Water Treatment Plant (WWTP) as experimental setup, off-gas method was selected to measure the oxygenating ability parameters of micropore aerators in a real WWTP operating condition and these values were compared with those in fresh water to evaluate the performance of the micropore aerators. Results showed that the micropore aerators which were distributed in different galleries of the aeration pool had significantly different oxygenating abilities under operation condition. The oxygenating ability of the micropore aerators distributed in the same gallery changed slightly during one day. Comparing with the oxygenating ability in fresh water, it decreased a lot in the real aeration pool, in more details, under the real WWTP operating condition, the values of oxygen transfer coefficient K(La) oxygenation capacity OC and oxygen utilization E(a) decreased by 43%, 57% and 76%, respectively.

Repulsive hydration forces between calcite surfaces and their effect on the brittle strength of calcite-bearing rocks

NASA Astrophysics Data System (ADS)

Røyne, Anja; Dalby, Kim N.; Hassenkam, Tue

2015-06-01

The long-term mechanical strength of calcite-bearing rocks is highly dependent on the presence and nature of pore fluids, and it has been suggested that the observed effects are due to changes in nanometer-scale surface forces near fracture tips and grain contacts. In this letter, we present measurements of forces between two calcite surfaces in air and water-glycol mixtures using the atomic force microscope. We show a time- and load-dependent adhesion at low water concentrations and a strong repulsion in the presence of water, which is most likely due to hydration of the strongly hydrophilic calcite surfaces. We argue that this hydration repulsion can explain the commonly observed water-induced decrease in strength in calcitic rocks and single calcite crystals. Furthermore, this relatively simple experimental setup may serve as a useful tool for analyzing surface forces in other mineral-fluid combinations.

Pesticide-sampling equipment, sample-collection and processing procedures, and water-quality data at Chicod Creek, North Carolina, 1992

USGS Publications Warehouse

Manning, T.K.; Smith, K.E.; Wood, C.D.; Williams, J.B.

1994-01-01

Water-quality samples were collected from Chicod Creek in the Coastal Plain Province of North Carolina during the summer of 1992 as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Chicod Creek is in the Albemarle-Pamlico drainage area, one of four study units designated to test equipment and procedures for collecting and processing samples for the solid-phase extraction of selected pesticides, The equipment and procedures were used to isolate 47 pesticides, including organonitrogen, carbamate, organochlorine, organophosphate, and other compounds, targeted to be analyzed by gas chromatography/mass spectrometry. Sample-collection and processing equipment equipment cleaning and set-up procedures, methods pertaining to collecting, splitting, and solid-phase extraction of samples, and water-quality data resulting from the field test are presented in this report Most problems encountered during this intensive sampling exercise were operational difficulties relating to equipment used to process samples.

Droplets on bent fibers

NASA Astrophysics Data System (ADS)

Weyer, Floriane; Pan, Zhao; Pitt, William; Truscott, Tadd; Vandewalle, Nicolas

Droplets on fibers are part of our everyday lives. Many phenomena involve drops and fibers such as the formation of dew droplets on a spiderweb, the trapping of water droplets on cactus spines or the motion of droplets on wetted moss hairs. These topics have been widely studied. In particular, Lorenceau et al. determined the critical volume of a water droplet hanging on a horizontal fiber. Here, we address a similar question : we try to find out the maximum droplet size on bent fibers, which are able to hold significantly more water than horizontal fibers. Indeed, we noticed that, in nature, some specific plants can hold large rain droplets thanks to their Y-shaped leaves. We try to mimic these structures with nylon fibers, of different diameters, bent with various angles. For each set-up, the critical water volume is determined. Finally, we propose models of the physics involved in determining droplet size that could be implemented in future fiber-based microfluidic devices.

Towards metering tap water by Lorentz force velocimetry

NASA Astrophysics Data System (ADS)

Vasilyan, Suren; Ebert, Reschad; Weidner, Markus; Rivero, Michel; Halbedel, Bernd; Resagk, Christian; Fröhlich, Thomas

2015-11-01

In this paper, we present enhanced flow rate measurement by applying the contactless Lorentz Force Velocimetry (LFV) technique. Particularly, we show that the LFV is a feasible technique for metering the flow rate of salt water in a rectangular channel. The measurements of the Lorentz forces as a function of the flow rate are presented for different electrical conductivities of the salt water. The smallest value of conductivity is achieved at 0.06 S·m-1, which corresponds to the typical value of tap water. In comparison with previous results, the performance of LFV is improved by approximately 2 orders of magnitude by means of a high-precision differential force measurement setup. Furthermore, the sensitivity curve and the calibration factor of the flowmeter are provided based on extensive measurements for the flow velocities ranging from 0.2 to 2.5 m·s-1 and conductivities ranging from 0.06 to 10 S·m-1.

Infant multiple breath washout using a new commercially available device: Ready to replace the previous setup?

PubMed

Kentgens, Anne-Christianne; Guidi, Marisa; Korten, Insa; Kohler, Lena; Binggeli, Severin; Singer, Florian; Latzin, Philipp; Anagnostopoulou, Pinelopi

2018-05-01

Multiple breath washout (MBW) is a sensitive test to measure lung volumes and ventilation inhomogeneity from infancy on. The commonly used setup for infant MBW, based on ultrasonic flowmeter, requires extensive signal processing, which may reduce robustness. A new setup may overcome some previous limitations but formal validation is lacking. We assessed the feasibility of infant MBW testing with the new setup and compared functional residual capacity (FRC) values of the old and the new setup in vivo and in vitro. We performed MBW in four healthy infants and four infants with cystic fibrosis, as well as in a Plexiglas lung simulator using realistic lung volumes and breathing patterns, with the new (Exhalyzer D, Spiroware 3.2.0, Ecomedics) and the old setup (Exhalyzer D, WBreath 3.18.0, ndd) in random sequence. The technical feasibility of MBW with the new device-setup was 100%. Intra-subject variability in FRC was low in both setups, but differences in FRC between the setups were considerable (mean relative difference 39.7%, range 18.9; 65.7, P = 0.008). Corrections of software settings decreased FRC differences (14.0%, -6.4; 42.3, P = 0.08). Results were confirmed in vitro. MBW measurements with the new setup were feasible in infants. However, despite attempts to correct software settings, outcomes between setups were not interchangeable. Further work is needed before widespread application of the new setup can be recommended. © 2018 Wiley Periodicals, Inc.

Hexabromocyclododecane affects benthic-pelagic coupling in an experimental ecosystem.

PubMed

Bradshaw, Clare; Näslund, Johan; Hansen, Joakim; Kozlowsky-Suzuki, Betina; Sundström, Bo; Gustafsson, Kerstin

2015-11-01

Hexabromocyclododecane (HBCDD) is an additive brominated flame retardant and a recognized PBT chemical. However, little is known about its effects on coastal species, and even less on ecosystem effects. We investigated the dose-response effects of HBCDD over 8 months in 1000 L experimental mesocosms assembled from coastal Baltic Sea ecosystem components. HBCDD was added via spiked plankton material and a range of structural and functional endpoints were measured during the experiment. Increasing HBCDD concentration decreased the biomass of large Macoma balthica, resulting in a decreased recirculation of nutrients to the water. Changes in plankton communities were also observed, either due to direct toxic HBCDD effects or indirect via changes in benthic-pelagic coupling of nutrients. Such complex ecosystem responses can only be quantified and understood by using realistic experimental set-ups, and including knowledge of system-specific ecological interactions. This is the first study of HBCDD effects on ecosystem level. Copyright © 2015 Elsevier Ltd. All rights reserved.

Low-grazing angle laser scans of foreshore topography, swash and inner surf-zone wave heights, and mean water level: validation and storm response

NASA Astrophysics Data System (ADS)

Brodie, K. L.; McNinch, J. E.; Forte, M.; Slocum, R.

2010-12-01

Accurately predicting beach evolution during storms requires models that correctly parameterize wave runup and inner surf-zone processes, the principle drivers of sediment exchange between the beach and surf-zone. Previous studies that aimed at measuring wave runup and swash zone water levels have been restricted to analyzing water-elevation time series of (1) the shoreward-most swash excursion using video imaging or near-bed resistance wires, or (2) the free water surface at a particular location on the foreshore using pressure sensors. These data are often compared with wave forcing parameters in deeper water as well as with beach topography observed at finite intervals throughout the time series to identify links between foreshore evolution, wave spectra, and water level variations. These approaches have lead to numerous parameterizations and empirical equations for wave runup but have difficulty providing adequate data to quantify and understand short-term spatial and temporal variations in foreshore evolution. As a result, modeling shoreline response and changes in sub-aerial beach volume during storms remains a substantial challenge. Here, we demonstrate a novel technique in which a terrestrial laser scanner is used to continuously measure beach and foreshore topography as well as water elevation (and wave height) in the swash and inner surf-zone during storms. The terrestrial laser scanner is mounted 2-m above the dune crest at the Field Research Facility in Duck, NC in line with cross-shore wave gauges located at 2-m, 3-m, 5-m, 6-m, and 8-m of water depth. The laser is automated to collect hourly, two-dimensional, 20-minute time series of data along a narrow swath in addition to an hourly three-dimensional laser scan of beach and dune topography +/- 250m alongshore from the laser. Low grazing-angle laser scans are found to reflect off of the surface of the water, providing spatially (e.g. dx <= 0.1 m) and temporally (e.g. dt = 3Hz) dense elevation data of the foreshore, swash, and inner-surf zone bore heights. Foreshore elevation precision is observed to be < 0.01m. Sea surface elevation data is confined to the breaking region and is more extensive in rough, fully-dissipative surf zones, with the fronts of breaking waves and dissipated bores resolved most clearly. Time series of swash front (runup) data will be compared with simultaneously collected video-imaged swash timestacks, and wave height data of the inner surf zone will be compared with wave data from an aquadopp in 2m of water depth. In addition, analysis of the water level time series data at 10 cm intervals across the profile enables reconstruction of the shoreline setup profile as well as cross-shore variations in 1D wave spectra. Foreshore beach morphology evolution is analyzed using both the 2D cross-shore profile data, as well as the 3D topographic data during multiple storm events. Potential sources of error in the measurements, such as shadowing of the wave troughs or reflectance off of wave spray is identified and quantified.

A flexible hydrological warning system in Denmark for real-time surface water and groundwater simulations

NASA Astrophysics Data System (ADS)

He, Xin; Stisen, Simon; Wiese, Marianne B.; Jørgen Henriksen, Hans

2015-04-01

In Denmark, increasing focus on extreme weather events has created considerable demand for short term forecasts and early warnings in relation to groundwater and surface water flooding. The Geological Survey of Denmark and Greenland (GEUS) has setup, calibrated and applied a nationwide water resources model, the DK-Model, primarily for simulating groundwater and surface water flows and groundwater levels during the past 20 years. So far, the DK-model has only been used in offline historical and future scenario simulations. Therefore, challenges arise in operating such a model for online forecasts and early warnings, which requires access to continuously updated observed climate input data and forecast data of precipitation, temperature and global radiation for the next 48 hours or longer. GEUS has a close collaboration with the Danish Meteorological Institute in order to test and enable this data input for the DK model. Due to the comprehensive physical descriptions of the DK-Model, the simulation results can potentially be any component of the hydrological cycle within the models domain. Therefore, it is important to identify which results need to be updated and saved in the real-time mode, since it is not computationally economical to save every result considering the heavy load of data. GEUS have worked closely with the end-users and interest groups such as water planners and emergency managers from the municipalities, water supply and waste water companies, consulting companies and farmer organizations, in order to understand their possible needs for real time simulation and monitoring of the nationwide water cycle. This participatory process has been supported by a web based questionnaire survey, and a workshop that connected the model developers and the users. For qualifying the stakeholder engagement, GEUS has selected a representative catchment area (Skjern River) for testing and demonstrating a prototype of the web based hydrological warning system at the workshop, and illustrated simulated groundwater levels, streamflow and water content in the root zone. The webpages can be tailor-made to meet the requirements of the end-users and also enable flexibility to extend while the users' demand changes. The active involvement of stakeholders in the workshop provided very valuable insights and feedbacks for GEUS, relevant for the future development of the nationwide real-time modeling and water cycle monitoring system for Denmark, including possible linking to early warning and real-time forecasting systems operating at the local scale.

Evaluation of coastal vulnerability: comparison of two different methodologies adopted by the Emilia-Romagna Region (Italy)

NASA Astrophysics Data System (ADS)

Armaroli, Clara; Perini, Luisa; Calabrese, Lorenzo; Ciavola, Paolo; Salerno, Giovanni

2014-05-01

In the last years a large number of catastrophic events have occurred along worldwide coastlines (e.g.: 2012 Super-storm Sandy, US East Coast). European countries have to face similar calamities such as those caused by the recent Xaver cyclone (December 2013). The Emilia-Romagna coastline, Italy, along the North Adriatic Sea, is affected by storms that cause extensive damages. The coast has low elevations, is highly urbanised and there is a massive presence of defence structures. The area is micro-tidal (neap/spring tide ranges = 0.4/0.8 m), low energetic (65% Hs<=1 m) but subjected to significant surge levels (1 year return period = 0.85 m). Therefore an evaluation of the vulnerability of the coastal area is an urgent matter. The Regional Geological Survey has completed an analysis of three scenarios of damage produced by the concurrent happening of a marine storm and high surge levels (1-in-1, 10, 100 year return period) and high spring tidal levels (+0.45 m MSL). Wave heights were used to calculate run-up values along the whole coastline (on 187 equally spaced profiles extracted from LIDAR datasets). The result is a list of ten typology of different levels of damage obtained through the comparison between the computed water levels, for each scenario and along each profile, and the topography/human occupation of the coast. The assessment reveals that 60% of the coastline is vulnerable to the 1-in-1 year return period scenario, thus even modal meteorological conditions can generate significant losses. A comparison was made between the produced typologies and the actual damage caused by a recent storm and the correspondence is almost identical, underlining that the method is reliable. Because the above-mentioned methodology is only punctual, the Geological Survey has started a different evaluation of the areal extension of inundations. The methodology considers the concurrent happening of the same return period storms but in terms of wave set-up only (not including run-up) plus surge levels (extracted from the literature) plus high spring tide level. To find the extension of inundated areas and the intrusion distance of marine water inland, the Cost-Distance tool of ArcGIS was used. The tool is able to evaluate the contribution of each "cell", in which the coast has been divided (from LIDAR data), to avoid or favour the water movement inland, considering its location with respect to the shoreline, its elevation above MSL and the elevation/location of nearby cells. It does not account for water infiltration and terrain roughness, therefore, to avoid getting unrealistic results, an attenuation artifice was introduced: the maximum water level surface, calculated for each return period, is projected inland following a sloping plane. The intrusion distance is determined by the intersection of the oblique water surface and the ground. This artifice, together with the Cost-Distance tool, produces consistent results if compared to observed inundations with similar return periods. A further implementation of coastal vulnerability assessment will be performed through numerical modelling and Bayesian approaches (RISC-KIT EU Project, www.risckit.eu, GA 603458).

Impacts of urbanization and climate on groundwater in a growing Africa city: the case of Ouagadougou (Burkina Faso)

NASA Astrophysics Data System (ADS)

Mouhouddine, Alihoumadi; Yameogo, Suzanne; Genthon, Pierre; Travi, Yves

2016-04-01

African cities are presently facing the combined impacts of growing urbanization and climate change. In several instances; providing safe drinking water for all is still a challenge, especially for cities located on basement aquifers, were groundwater is scarce. Here we assess the effects of climate change and land use change on groundwater amount and quality in the main city of Ouagadougou (Burkina Faso) taking advantage of the CIEH borehole, where a mostly continuous record lasts since 1978. This record spans most of the Great African Drought (1970-1990) and recovery from the Drought since the 2000s. A piezometric network of 14 wells and boreholes was setup around the CIEH borehole and monitored during the 2013-2014 hydrologic year. The piezometric network spans an old settlement, the Ouagadougou University, a vegetable gardening area and a natural forested area. Water balance estimates are provided by a 1D box model. The study area, although it lies partly on an old settlement in Ouagadougou and on the University area, presents a rather uniform runoff coefficient of 22% and ET amounting to 80-90 % of rainfall, which usually characterizes natural areas. It is suspected that the almost absence of asphalted surfaces, the presence of trees and flow of rainwater from roofs toward bare soils or sumps could be responsible of this budget. However, the two wells located in the forested Bangr Weogo recreational area are characterized by almost no runoff and a nearly 100 % ET. While drinking water can be pumped in several places in the city of Ouagadougou, chemical major analyses show that two mechanisms impact groundwater quality during the rainy season: (i) rise of the water table at pit latrine level, mainly in old settlements, and entrainment of harmful substances from soil to the aquifer in gardening area near some artisan activities. The CIEH borehole is not fully representative of its neighboring area since (i) it lies in a piezometric low, (ii) it presents the smallest annual amplitude of the whole network. Modeling the 1978-2013 record at this borehole requires a nearly 10 % increase of recharge since 1990-1991, a period corresponding to partial and temporary recovery of rainfall after the Drought. Its water level lies nearly at the 1978 level; however, without the parameter change in 1991, it would lies 3 m below this level. Further extensive characterizations of hydrological properties near the CIEH borehole are suggested to allow further interpretations of its unique record.

A mobile detector for measurements of the atmospheric muon flux

NASA Astrophysics Data System (ADS)

Mitrica, B.; Brancus, I. M.; Margineanu, R.; Petcu, M.; Dima, M.; Sima, O.; Haungs, A.; Rebel, H.; Petre, M.; Toma, G.; Saftoiu, A.; Apostu, A.

2011-04-01

Measurements of the underground atmospheric muon flux are important in order to determine accurately the overburden in mwe (meter water equivalent) of an underground laboratory for appreciating which kind of experiments are feasible for that location. Slanic- Prohava is one of the 7 possible locations for the European large underground experiment LAGUNA (Large Apparatus studying Grand Unification and Neutrino Astrophysics). A mobile device consisting of 2 scintillator plates (≍0.9 m2, each) one above the other and measuring in coincidence, was set-up for determining the muon flux. The detector it is installed on a van which facilitates measurements on different positions at the surface or in the underground and it is in operation since autumn 2009. The measurements of muon fluxes presented in this contribution have been performed in the underground salt mine Slanic-Prahova, Romania, where IFIN-HH has built a low radiation level laboratory, and at the surface on different sites of Romania, at different elevations from 0 m a.s.l up to 655 m a.s.l. Based on our measurements we can say that Slanic site is a feasible location for LAGUNA in Unirea salt mine at a water equivalent depth of 600 mwe. The results have been compared with Monte-Carlo simulations performed with the simulation codes CORSIKA and MUSIC.

Calibrated complex impedance of CHO cells and E. coli bacteria at GHz frequencies using scanning microwave microscopy

NASA Astrophysics Data System (ADS)

Tuca, Silviu-Sorin; Badino, Giorgio; Gramse, Georg; Brinciotti, Enrico; Kasper, Manuel; Oh, Yoo Jin; Zhu, Rong; Rankl, Christian; Hinterdorfer, Peter; Kienberger, Ferry

2016-04-01

The application of scanning microwave microscopy (SMM) to extract calibrated electrical properties of cells and bacteria in air is presented. From the S 11 images, after calibration, complex impedance and admittance images of Chinese hamster ovary cells and E. coli bacteria deposited on a silicon substrate have been obtained. The broadband capabilities of SMM have been used to characterize the bio-samples between 2 GHz and 20 GHz. The resulting calibrated cell and bacteria admittance at 19 GHz were Y cell = 185 μS + j285 μS and Y bacteria = 3 μS + j20 μS, respectively. A combined circuitry-3D finite element method EMPro model has been developed and used to investigate the frequency response of the complex impedance and admittance of the SMM setup. Based on a proposed parallel resistance-capacitance model, the equivalent conductance and parallel capacitance of the cells and bacteria were obtained from the SMM images. The influence of humidity and frequency on the cell conductance was experimentally studied. To compare the cell conductance with bulk water properties, we measured the imaginary part of the bulk water loss with a dielectric probe kit in the same frequency range resulting in a high level of agreement.

[Study of high temperature water vapor concentration measurement method based on absorption spectroscopy].

PubMed

Chen, Jiu-ying; Liu, Jian-guo; He, Jun-feng; He, Ya-bai; Zhang, Guang-le; Xu, Zhen-yu; Gang, Qiang; Wang, Liao; Yao, Lu; Yuan, Song; Ruan, Jun; Dai, Yun-hai; Kan, Rui-feng

2014-12-01

Tunable diode laser absorption spectroscopy (TDLAS) has been developed to realize the real-time and dynamic measurement of the combustion temperature, gas component concentration, velocity and other flow parameters, owing to its high sensitivity, fast time response, non-invasive character and robust nature. In order to obtain accurate water vapor concentration at high temperature, several absorption spectra of water vapor near 1.39 μm from 773 to 1273 K under ordinary pressure were recorded in a high temperature experiment setup using a narrow band diode laser. The absorbance of high temperature absorption spectra was calculated by combined multi-line nonlinear least squares fitting method. Two water vapor absorption lines near 7154.35 and 7157.73 cm(-1) were selected for measurement of water vapor at high temperature. A model method for high temperature water vapor concentration was first proposed. Water vapor concentration from the model method at high temperature is in accordance with theoretical reasoning, concentration measurement standard error is less than 0.2%, and the relative error is less than 6%. The feasibility of this measuring method is verified by experiment.

An optical sensor for detecting the contact location of a gas-liquid interface on a body.

PubMed

Belden, Jesse; Jandron, Michael

2014-08-01

An optical sensor for detecting the dynamic contact location of a gas-liquid interface along the length of a body is described. The sensor is developed in the context of applications to supercavitating bodies requiring measurement of the dynamic cavity contact location; however, the sensing method is extendable to other applications as well. The optical principle of total internal reflection is exploited to detect changes in refractive index of the medium contacting the body at discrete locations along its length. The derived theoretical operation of the sensor predicts a signal attenuation of 18 dB when a sensed location changes from air-contacting to water-contacting. Theory also shows that spatial resolution (d) scales linearly with sensor length (L(s)) and a resolution of 0.01L(s) can be achieved. A prototype sensor is constructed from simple components and response characteristics are quantified for different ambient light conditions as well as partial wetting states. Three methods of sensor calibration are described and a signal processing framework is developed that allows for robust detection of the gas-liquid contact location. In a tank draining experiment, the prototype sensor resolves the water level with accuracy limited only by the spatial resolution, which is constrained by the experimental setup. A more representative experiment is performed in which the prototype sensor accurately measures the dynamic contact location of a gas cavity on a water tunnel wall.

A Comparative Study of Emotional Stability of Visually Impaired Students Studying at Secondary Level in Inclusive Setup and Special Schools

ERIC Educational Resources Information Center

Pant, Pankaj; Joshi, P. K.

2016-01-01

Visual impairment as an umbrella term includes all levels of vision loss. Researches in the field of visual disability are far from satisfactory in India. Some attempts have been made to study different aspects of the lives of visually disabled children. Such attempts help, revealing the facts of their life, characteristics, activities,…

The Effect of Defense Contracting Requirements on Just-In-Time Implementation

DTIC Science & Technology

1988-12-01

and purchasing efforts negatively impacted. The role of I11 contract uncertainty was weakest and had mixed effects. Difficult negotiations prior to...they recommend differs somewhat. Shingo stresses the use of setup reduction and layout changes early in his sequence with production leveling occurring...consciousness toward quality improvement, and use of foolproof mechanisms to prevent errors), higher level government quality standards stress separate

Performance Assessment of Passive Hearing Protection Devices

DTIC Science & Technology

2014-10-24

ear ................................................ 9 Figure 11. Schematic of the set-up of the explosive charge for the creation of a shock wave...10 Table 1: Type and mass of explosive and distance between ATF and explosive for different peak pressure levels and A-durations...OF TABLES Table 1: Type and mass of explosive and distance between ATF and explosive for different peak pressure levels and A-durations

Sizing and modelling of photovoltaic water pumping system

NASA Astrophysics Data System (ADS)

Al-Badi, A.; Yousef, H.; Al Mahmoudi, T.; Al-Shammaki, M.; Al-Abri, A.; Al-Hinai, A.

2018-05-01

With the decline in price of the photovoltaics (PVs) their use as a power source for water pumping is the most attractive solution instead of using diesel generators or electric motors driven by a grid system. In this paper, a method to design a PV pumping system is presented and discussed, which is then used to calculate the required size of the PV for an existing farm. Furthermore, the amount of carbon dioxide emissions saved by the use of PV water pumping system instead of using diesel-fuelled generators or electrical motor connected to the grid network is calculated. In addition, an experimental set-up is developed for the PV water pumping system using both DC and AC motors with batteries. The experimental tests are used to validate the developed MATLAB model. This research work demonstrates that using the PV water pumping system is not only improving the living conditions in rural areas but it is also protecting the environment and can be a cost-effective application in remote locations.

Efficient Light-Driven Water Oxidation Catalysis by Dinuclear Ruthenium Complexes.

PubMed

Berardi, Serena; Francàs, Laia; Neudeck, Sven; Maji, Somnath; Benet-Buchholz, Jordi; Meyer, Franc; Llobet, Antoni

2015-11-01

Mastering the light-induced four-electron oxidation of water to molecular oxygen is a key step towards the achievement of overall water splitting to produce alternative solar fuels. In this work, we report two rugged molecular pyrazolate-based diruthenium complexes that efficiently catalyze visible-light-driven water oxidation. These complexes were fully characterized both in the solid state (by X-ray diffraction analysis) and in solution (spectroscopically and electrochemically). Benchmark performances for homogeneous oxygen production have been obtained for both catalysts in the presence of a photosensitizer and a sacrificial electron acceptor at pH 7, and a turnover frequency of up to 11.1 s(-1) and a turnover number of 5300 were obtained after three successive catalytic runs. Under the same experimental conditions with the same setup, the pyrazolate-based diruthenium complexes outperform other well-known water oxidation catalysts owing to both electrochemical and mechanistic aspects. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isolation and identification of Mycobacterium avium complex and other nontuberculosis mycobacteria from drinking-water in Basra governorate, Iraq.

PubMed

Al-Sulami, A A; Al-Taee, A M R; Wida'a, Q H

2012-03-01

This study aimed to determine the occurrence of Mycobacterium avium complex and other nontuberculous mycobacteria in drinking-water in Basra governorate, Iraq and their susceptibility to several antibiotics and the effect of 0.5 mg/L of chlorine on their survival. A total of 404 samples of drinking-water were collected from 33 different districts of the governorate from November 2006 to August 2007. Filtered samples were incubated for 7 days or less in a monophasic-biphasic culture setup of tuberculosis broth and Lowenstein-Jensen agar. The 252 isolates were identified as M. avium complex (21), M. marinum (15), M. kansasii (30), M. simiae (20), M. szulgai (19), M. xenopi (16), M. malmoense (11), M. fortuitum (37), M. chelonae (50) and M. abscessus (33). Isolates were tested for antibiotic susceptibility as well as their ability to tolerate chlorine at a concentration of 0.5 mg/L. The presence of these pathogenic bacteria in drinking-water renders the water unfit for human consumption.

Analysis of dispatching rules in a stochastic dynamic job shop manufacturing system with sequence-dependent setup times

NASA Astrophysics Data System (ADS)

Sharma, Pankaj; Jain, Ajai

2014-12-01

Stochastic dynamic job shop scheduling problem with consideration of sequence-dependent setup times are among the most difficult classes of scheduling problems. This paper assesses the performance of nine dispatching rules in such shop from makespan, mean flow time, maximum flow time, mean tardiness, maximum tardiness, number of tardy jobs, total setups and mean setup time performance measures viewpoint. A discrete event simulation model of a stochastic dynamic job shop manufacturing system is developed for investigation purpose. Nine dispatching rules identified from literature are incorporated in the simulation model. The simulation experiments are conducted under due date tightness factor of 3, shop utilization percentage of 90% and setup times less than processing times. Results indicate that shortest setup time (SIMSET) rule provides the best performance for mean flow time and number of tardy jobs measures. The job with similar setup and modified earliest due date (JMEDD) rule provides the best performance for makespan, maximum flow time, mean tardiness, maximum tardiness, total setups and mean setup time measures.

Destructive tsunami-like wave generated by surf beat over a coral reef during Typhoon Haiyan.

PubMed

Roeber, Volker; Bricker, Jeremy D

2015-08-06

Storm surges cause coastal inundation due to setup of the water surface resulting from atmospheric pressure, surface winds and breaking waves. Here we show that during Typhoon Haiyan, the setup generated by breaking waves near the fringing-reef-protected town of Hernani, the Philippines, oscillated with the incidence of large and small wave groups, and steepened into a tsunami-like wave that caused extensive damage and casualties. Though fringing reefs usually protect coastal communities from moderate storms, they can exacerbate flooding during strong events with energetic waves. Typical for reef-type bathymetries, a very short wave-breaking zone over the steep reef face facilitates the freeing of infragravity-period fluctuations (surf beat) with little energy loss. Since coastal flood planning relies on phase-averaged wave modelling, infragravity surges are not being accounted for. This highlights the necessity for a policy change and the adoption of phase-resolving wave models for hazard assessment in regions with fringing reefs.

Destructive tsunami-like wave generated by surf beat over a coral reef during Typhoon Haiyan

PubMed Central

Roeber, Volker; Bricker, Jeremy D.

2015-01-01

Storm surges cause coastal inundation due to setup of the water surface resulting from atmospheric pressure, surface winds and breaking waves. Here we show that during Typhoon Haiyan, the setup generated by breaking waves near the fringing-reef-protected town of Hernani, the Philippines, oscillated with the incidence of large and small wave groups, and steepened into a tsunami-like wave that caused extensive damage and casualties. Though fringing reefs usually protect coastal communities from moderate storms, they can exacerbate flooding during strong events with energetic waves. Typical for reef-type bathymetries, a very short wave-breaking zone over the steep reef face facilitates the freeing of infragravity-period fluctuations (surf beat) with little energy loss. Since coastal flood planning relies on phase-averaged wave modelling, infragravity surges are not being accounted for. This highlights the necessity for a policy change and the adoption of phase-resolving wave models for hazard assessment in regions with fringing reefs. PMID:26245839

Pressure jump relaxation setup with IR detection and millisecond time resolution

NASA Astrophysics Data System (ADS)

Schiewek, Martin; Krumova, Marina; Hempel, Günter; Blume, Alfred

2007-04-01

An instrument is described that allows the use of Fourier transform infrared (FTIR) spectroscopy as a detection system for kinetic processes after a pressure jump of up to 100bars. The pressure is generated using a high performance liquid chromatography (HPLC) pump and water as a pressure transducing medium. A flexible membrane separates the liquid sample in the IR cell from the pressure transducing medium. Two electromagnetic switching valves in the setup enable pressure jumps with a decay time of 4ms. The FTIR spectrometer is configured to measure time resolved spectra in the millisecond time regime using the rapid scan mode. All components are computer controlled. For a demonstration of the capability of the method first results on the kinetics of a phase transition between two lamellar phases of an aqueous phospholipid dispersion are presented. This combination of FTIR spectroscopy with the pressure jump relaxation technique can also be used for other systems which display cooperative transitions with concomitant volume changes.

Stress dependence of permeability of intact and fractured shale cores.

NASA Astrophysics Data System (ADS)

van Noort, Reinier; Yarushina, Viktoriya

2016-04-01

Whether a shale acts as a caprock, source rock, or reservoir, understanding fluid flow through shale is of major importance for understanding fluid flow in geological systems. Because of the low permeability of shale, flow is thought to be largely confined to fractures and similar features. In fracking operations, fractures are induced specifically to allow for hydrocarbon exploration. We have constructed an experimental setup to measure core permeabilities, using constant flow or a transient pulse. In this setup, we have measured the permeability of intact and fractured shale core samples, using either water or supercritical CO2 as the transporting fluid. Our measurements show decreasing permeability with increasing confining pressure, mainly due to time-dependent creep. Furthermore, our measurements show that for a simple splitting fracture, time-dependent creep will also eliminate any significant effect of this fracture on permeability. This effect of confinement on fracture permeability can have important implications regarding the effects of fracturing on shale permeability, and hence for operations depending on that.

Effect of sound level on virtual and free-field localization of brief sounds in the anterior median plane.

PubMed

Marmel, Frederic; Marrufo-Pérez, Miriam I; Heeren, Jan; Ewert, Stephan; Lopez-Poveda, Enrique A

2018-06-14

The detection of high-frequency spectral notches has been shown to be worse at 70-80 dB sound pressure level (SPL) than at higher levels up to 100 dB SPL. The performance improvement at levels higher than 70-80 dB SPL has been related to an 'ideal observer' comparison of population auditory nerve spike trains to stimuli with and without high-frequency spectral notches. Insofar as vertical localization partly relies on information provided by pinna-based high-frequency spectral notches, we hypothesized that localization would be worse at 70-80 dB SPL than at higher levels. Results from a first experiment using a virtual localization set-up and non-individualized head-related transfer functions (HRTFs) were consistent with this hypothesis, but a second experiment using a free-field set-up showed that vertical localization deteriorates monotonically with increasing level up to 100 dB SPL. These results suggest that listeners use different cues when localizing sound sources in virtual and free-field conditions. In addition, they confirm that the worsening in vertical localization with increasing level continues beyond 70-80 dB SPL, the highest levels tested by previous studies. Further, they suggest that vertical localization, unlike high-frequency spectral notch detection, does not rely on an 'ideal observer' analysis of auditory nerve spike trains. Copyright © 2018 Elsevier B.V. All rights reserved.

A technique for searching for the 2 K capture in 124Xe with a copper proportional counter

NASA Astrophysics Data System (ADS)

Gavrilyuk, Yu. M.; Gangapshev, A. M.; Kazalov, V. V.; Kuzminov, V. V.; Panasenko, S. I.; Ratkevich, S. S.; Tekueva, D. A.; Yakimenko, S. P.

2015-12-01

An experimental technique for searching for the 2 K capture in 124Xe with a large low-background copper proportional counter is described. Such an experiment is conducted at the Baksan Neutrino Observatory of the Institute for Nuclear Research of the Russian Academy of Sciences. The experimental setup is located in the Low-Background Deep-Level Laboratory at a depth of 4900 m.w.e., where the flux of muons of cosmic rays is suppressed by a factor of 107 relative to that at the Earth's surface. The setup incorporates a proportional counter and low-background shielding (18 cm of copper, 15 cm of lead, and 8 cm of borated polyethylene). The results of processing the data obtained in 5 months of live measurement time are presented. A new limit on the half-life of 124Xe with respect to the 2 K capture is set at the level of 2.5 × 1021 years.

Aggregation and disaggregation dynamics of sedimented and charged superparamagnetic micro-particles in water suspension.

PubMed

Domínguez-García, P; Pastor, J M; Rubio, M A

2011-04-01

This article presents results on the aggregation and disaggregation kinetics on a 1 μm diameter charged superparamagnetic particles dispersed in water under a constant uniaxial magnetic field in experiments with salt (KCl) added to the suspension in order to observe the behaviour of the system when the electrical properties of the particles have been screened. These particles have an electric charge and are confined between two separated 100 μm thick quartz windows, and sediment near the charged bottom wall. The electrostatic interactions that take place in this experimental setup may affect the micro-structure and colloidal stability of the suspension and thus, the dynamics of aggregation and disaggregation.

Effects of coolant parameters on steady state temperature distribution in phospheric-acid fuel cell electrode

NASA Technical Reports Server (NTRS)

Alkasab, K. A.; Abdul-Aziz, A.

1991-01-01

The influence of thermophysical properties and flow rate on the steady-state temperature distribution in a phosphoric-acid fuel cell electrode plate was experimentally investigated. An experimental setup that simulates the operating conditions prevailing in a phosphoric-acid fuel cell stack was used. The fuel cell cooling system utilized three types of coolants to remove excess heat generated in the cell electrode and to maintain a reasonably uniform temperature distribution in the electrode plate. The coolants used were water, engine oil, and air. These coolants were circulated at Reynolds number ranging from 1165 to 6165 for water; 3070 to 6864 for air; and 15 to 79 for oil. Experimental results are presented.

Account of the intratrack radiolytic processes for interpretation of the AMOC spectrum of liquid water

NASA Astrophysics Data System (ADS)

Zvezhinskiy, D. S.; Butterling, M.; Wagner, A.; Krause-Rehberg, R.; Stepanov, S. V.

2013-06-01

Recent development of the Gamma-induced Positron Spectroscopy (GiPS) setup significantly extends applicability of the Age-Momentum Correlation technique (AMOC) for studies of the bulk samples. It also provides many advantages comparing with conventional positron annihilation experiments in liquids, such as extremely low annihilation fraction in vessel walls, absence of a positron source and positron annihilations in it. We have developed a new approach for processing and interpretation of the AMOC-GiPS data based on the diffusion recombination model of the intratrack radiolytic processes. This approach is verified in case of liquid water, which is considered as a reference medium in the positron and positronium chemistry.

Capillary Structures for Exploration Life Support (Capillary Structures)

NASA Image and Video Library

2017-07-10

iss052e013146 (July 10, 2017) --- Astronaut Jack Fischer is photographed during setup of hardware for the Capillary Structures for Exploration Life Support (Capillary Structures) two sorbent demonstrations. The Capillary Structures for Exploration Life Support (Capillary Structures) investigation studies a new method using structures of specific shapes to manage fluid and gas mixtures. The investigation studies water recycling and carbon dioxide removal, benefiting future efforts to design lightweight, more reliable life support systems for future space missions.

Oceanic Whitecaps and Associated, Bubble-Mediated, Air-Sea Exchange Processes

DTIC Science & Technology

1992-10-01

experiments performed in laboratory conditions using Air-Sea Exchange Monitoring System (A-SEMS). EXPERIMENTAL SET-UP In a first look, the Air-Sea Exchange...Model 225, equipped with a Model 519 plug-in module. Other complementary information on A-SEMS along with results from first tests and calibration...between 9.50C and 22.40C within the first 24 hours after transferring the water sample into laboratory conditions. The results show an enhancement of

Heat transfer augmentation of a car radiator using nanofluids

NASA Astrophysics Data System (ADS)

Hussein, Adnan M.; Bakar, R. A.; Kadirgama, K.; Sharma, K. V.

2014-05-01

The car radiator heat transfer enhancement by using TiO2 and SiO2 nanoparticles dispersed in water as a base fluid was studied experimentally. The test rig is setup as a car radiator with tubes and container. The range of Reynolds number and volume fraction are (250-1,750) and (1.0-2.5 %) respectively. Results showed that the heat transfer increases with increasing of nanofluid volume fraction. The experimental data is agreed with other investigator.

Closed Loop Control and Turbulent Flows

DTIC Science & Technology

2005-10-01

10 2.9 A schematic diagram of the PIV setup. The PIV controller synchronizes the firing of the lasers and camera...is 16 ms. Consequently, the frequency scaling factor, f*, is 62 Hz. Twin Nd:YAG PIv Back Laser , measurement tressur I5 area tank Water’SuppIly Laser ...YAG twin 532-nm laser was used to illuminate the flow field, and 8-bit gTay-scale images were captured using a 1360 by 1024-pixel resolution camera

Non-Dispersive Infrared Sensor for Online Condition Monitoring of Gearbox Oil.

PubMed

Rauscher, Markus S; Tremmel, Anton J; Schardt, Michael; Koch, Alexander W

2017-02-18

The condition of lubricating oil used in automotive and industrial gearboxes must be controlled in order to guarantee optimum performance and prevent damage to machinery parts. In normal practice, this is done by regular oil change intervals and routine laboratory analysis, both of which involve considerable operating costs. In this paper, we present a compact and robust optical sensor that can be installed in the lubrication circuit to provide quasi-continuous information about the condition of the oil. The measuring principle is based on non-dispersive infrared spectroscopy. The implemented sensor setup consists of an optical measurement cell, two thin-film infrared emitters, and two four-channel pyroelectric detectors equipped with optical bandpass filters. We present a method based on multivariate partial least squares regression to select appropriate optical bandpass filters for monitoring the oxidation, water content, and acid number of the oil. We perform a ray tracing analysis to analyze and correct the influence of the light path in the optical setup on the optical parameters of the bandpass filters. The measurement values acquired with the sensor for three different gearbox oil types show high correlation with laboratory reference data for the oxidation, water content, and acid number. The presented sensor can thus be a useful supplementary tool for the online condition monitoring of lubricants when integrated into a gearbox oil circuit.

Non-Dispersive Infrared Sensor for Online Condition Monitoring of Gearbox Oil

PubMed Central

Rauscher, Markus S.; Tremmel, Anton J.; Schardt, Michael; Koch, Alexander W.

2017-01-01

The condition of lubricating oil used in automotive and industrial gearboxes must be controlled in order to guarantee optimum performance and prevent damage to machinery parts. In normal practice, this is done by regular oil change intervals and routine laboratory analysis, both of which involve considerable operating costs. In this paper, we present a compact and robust optical sensor that can be installed in the lubrication circuit to provide quasi-continuous information about the condition of the oil. The measuring principle is based on non-dispersive infrared spectroscopy. The implemented sensor setup consists of an optical measurement cell, two thin-film infrared emitters, and two four-channel pyroelectric detectors equipped with optical bandpass filters. We present a method based on multivariate partial least squares regression to select appropriate optical bandpass filters for monitoring the oxidation, water content, and acid number of the oil. We perform a ray tracing analysis to analyze and correct the influence of the light path in the optical setup on the optical parameters of the bandpass filters. The measurement values acquired with the sensor for three different gearbox oil types show high correlation with laboratory reference data for the oxidation, water content, and acid number. The presented sensor can thus be a useful supplementary tool for the online condition monitoring of lubricants when integrated into a gearbox oil circuit. PMID:28218701

EXPERIMENTAL EVALUATION OF THE THERMAL PERFORMANCE OF A WATER SHIELD FOR A SURFACE POWER REACTOR

DOE Office of Scientific and Technical Information (OSTI.GOV)

REID, ROBERT S.; PEARSON, J. BOSIE; STEWART, ERIC T.

2007-01-16

Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WSTmore » is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 C. The CFD model with 1/6-g predicts a maximum water temperature of 88 C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield.« less

The role of beach morphodynamic state on infragravity swash on beaches: field observations.

NASA Astrophysics Data System (ADS)

Gomes da Silva, Paula; González, Mauricio; Medina, Raul

2017-04-01

The runup generated by waves can be defined as the maximum height above sea water level on the coastline and is an important criterion for costal structures/nourishment design and erosion/flooding risk analysis. Given the complexity of nonlinear processes involved in the runup generation, its prediction is commonly made by means of empirical formulations that relate wave and beach parameters. The most accepted parametrization presented till the moment was proposed by Stockdon et al. (2006), in which the runup exceeded by 2 percent of the waves (R2) is described in terms of setup (η - the steady superelevation of the mean water level caused by breaking waves) and incident and infragravity swash (Sinc and Sig- time-varying fluctuations around the setup caused by non-breaking waves). Such formulation has been widely accepted and its efficiency was appraised in many works. Nevertheless, although empirical parametrization of infragravity swash using incident wave's parameters shows reasonable skill, the correlation can still present considerable scatter. The amount of infragravity energy on swash is directly related to the morphodynamic beach state, in a way that beach profiles classified as reflective (low wave energy, coarse sediment and higher beach slope) tend to show lower Sig values than dissipative ones (high wave energy, fine sediment and lower beach slope). However, since Stockdon's formula for predicting infragravity swash consider only wave parameters, its use implies that beaches receiving the same wave energy but with different grain size and beach slope would present the same Sig values. This work assumed the hypothesis that the scatter verified on the predictions of the infragravity swash is mainly related to the lack of information about the beach state in Stockdon formula. Based on that, a field campaign was designed and carried out in Somo-El Puntal beach, north Spain, with the aim of generating data to be analyzed in terms of infragravity swash. An important aspect about this field site is that, given the gradient of wave energy that reaches each part of the beach, it can present many morphodynamic states simultaneously, allowing a high range of measurements in a single beach. Thus, wave, currents, sediment and runup data were measured in three different profiles, as well as the whole beach topography, bathymetry and video camera images. These data, summed to those available from Stockdon study, were used to verify the validity of the hypothesis and to propose a new approach for empirically determining infragravity swash on beaches.

Adhesive Bonding for Optical Metrology Systems in Space Applications

NASA Astrophysics Data System (ADS)

Gohlke, Martin; Schuldt, Thilo; Döringshoff, Klaus; Peters, Achim; Johann, Ulrich; Weise, Dennis; Braxmaier, Claus

2015-05-01

Laser based metrology systems become more and more attractive for space applications and are the core elements of planned missions such as LISA (NGO, eLISA) or NGGM where laser interferometry is used for distance measurements between satellites. The GRACE-FO mission will for the first time demonstrate a Laser Ranging Instrument (LRI) in space, starting 2017. Laser based metrology also includes optical clocks/references, either as ultra-stable light source for high sensitivity interferometry or as scientific payload e.g. proposed in fundamental physics missions such as mSTAR (mini SpaceTime Asymmetry Research), a mission dedicated to perform a Kennedy-Thorndike experiment on a satellite in a low-Earth orbit. To enable the use of existing optical laboratory setups, optimization with respect to power consumption, weight and dimensions is necessary. At the same time the thermal and structural stability must be increased. Over the last few years we investigated adhesive bonding of optical components to thermally highly stable glass ceramics as an easy-to-handle assembly integration technology. Several setups were implemented and tested for potential later use in space applications. We realized a heterodyne LISA related interferometer with demonstrated noise levels in the pm-range for translation measurement and nano-radiant-range for tilt measurements and two iodine frequency references on Elegant Breadboard (EBB) and Engineering Model (EM) level with frequency stabilities in the 10-15 range for longer integration times. The EM setup was thermally cycled and vibration tested.

samiDB: A Prototype Data Archive for Big Science Exploration

NASA Astrophysics Data System (ADS)

Konstantopoulos, I. S.; Green, A. W.; Cortese, L.; Foster, C.; Scott, N.

2015-04-01

samiDB is an archive, database, and query engine to serve the spectra, spectral hypercubes, and high-level science products that make up the SAMI Galaxy Survey. Based on the versatile Hierarchical Data Format (HDF5), samiDB does not depend on relational database structures and hence lightens the setup and maintenance load imposed on science teams by metadata tables. The code, written in Python, covers the ingestion, querying, and exporting of data as well as the automatic setup of an HTML schema browser. samiDB serves as a maintenance-light data archive for Big Science and can be adopted and adapted by science teams that lack the means to hire professional archivists to set up the data back end for their projects.

SU-E-J-22: A Feasibility Study On KV-Based Whole Breast Radiation Patient Setup

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Q; Zhang, M; Yue, N

Purpose: In room kilovoltage x-ray (kV) imaging provides higher contrast than Megavoltage (MV) imaging with faster acquisition time compared with on-board cone-beam computed tomography (CBCT), thus improving patient setup accuracy and efficiency. In this study we evaluated the clinical feasibility of utilizing kV imaging for whole breast radiation patient setup. Methods: For six breast cancer patients with whole breast treatment plans using two opposed tangential fields, MV-based patient setup was conducted by aligning patient markers with in room lasers and MV portal images. Beam-eye viewed kV images were acquired using Varian OBI system after the set up process. In housemore » software was developed to transfer MLC blocks information overlaying onto kV images to demonstrate the field shape for verification. KV-based patient digital shift was derived by performing rigid registration between kV image and the digitally reconstructed radiography (DRR) to align the bony structure. This digital shift between kV-based and MV-based setup was defined as setup deviation. Results: Six sets of kV images were acquired for breast patients. The mean setup deviation was 2.3mm, 2.2mm and 1.8mm for anterior-posterior, superior-inferior and left-right direction respectively. The average setup deviation magnitude was 4.3±1.7mm for six patients. Patient with large breast had a larger setup deviation (4.4–6.2mm). There was no strong correlation between MV-based shift and setup deviation. Conclusion: A preliminary clinical workflow for kV-based whole breast radiation setup was established and tested. We observed setup deviation of the magnitude below than 5mm. With the benefit of providing higher contrast and MLC block overlaid on the images for treatment field verification, it is feasible to use kV imaging for breast patient setup.« less

Dynamics of Phase Transitions in a Snow Mass Containing Water-Soluble Salt Particles

NASA Astrophysics Data System (ADS)

Zelenko, V. L.; Heifets, L. I.; Orlov, Yu. N.; Voskresenskiy, N. M.

2018-07-01

A macrokinetic approach is used to describe the dynamics of phase transitions in a snow mass containing water-soluble salt particles. Equations are derived that describe the rate of salt granule dissolution and the change in the phase composition and temperature of a snow mass under the conditions of heat transfer with an isothermal surface. An experimental setup that models the change in the state of a snow mass placed on an isothermal surface is created to verify theoretical conclusions. Experimental observations of the change in temperature of the snow mass are compared to theoretical calculations. The mathematical model that is developed can be used to predict the state of a snow mass on roads treated with a deicing agent, or to analyze the state of snow masses containing water-soluble salt inclusions and resting on mountain slopes.

Characterization of large area ZnS(Ag) detector for gross alpha and beta activity measurements in tap water plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lunardon, M.; Cester, D.; Mistura, G.

2015-07-01

In this work we present the characterization of a large area 200 x 200 mm{sup 2} EJ-444 scintillation detector to be used for monitoring gross alpha and beta activity in tap water plants. Specific tests were performed to determine the best setup to readout the light from the detector side in order to have the possibility to stack many detectors and get a compact device with total active area of the order of 1 m{sup 2}. Alpha/Beta discrimination, efficiency and homogeneity tests were carried out with alpha and beta sources. Background from ambient radioactivity was measured as well. Alpha/beta real-timemore » monitoring in drinking water is a goal of the EU project TAWARA{sub R}TM. (authors)« less

The tensile strength of ice and dust aggregates and its dependence on particle properties

NASA Astrophysics Data System (ADS)

Gundlach, B.; Schmidt, K. P.; Kreuzig, C.; Bischoff, D.; Rezaei, F.; Kothe, S.; Blum, J.; Grzesik, B.; Stoll, E.

2018-06-01

The knowledge of the tensile strength of astrophysical dust and ice aggregates is of major importance to understand the early stages of planet formation in our solar system and cometary activity. In this letter we report on an experimental setup, developed to measure the tensile strength of granular, astrophysical relevant materials, such as water ice and silica aggregates. We found that the tensile strength of aggregates composed of monodisperse silica particles depends on the grain size of the used material and is in a good agreement with the predictions of earlier works. For aggregates consisting of polydisperse water-ice particles, the measured tensile strength is very low compared to the theoretical prediction, which indicates that the specific surface energy of water ice at low temperatures is lower than previously assumed.

[Comparison of four identical electronic noses and three measurement set-ups].

PubMed

Koczulla, R; Hattesohl, A; Biller, H; Hofbauer, J; Hohlfeld, J; Oeser, C; Wirtz, H; Jörres, R A

2011-08-01

Volatile organic compounds (VOCs) can be used as biomarkers in exhaled air. VOC profiles can be detected by an array of nanosensors of an electronic nose. These profiles can be analysed using bioinformatics. It is, however, not known whether different devices of the same model measure identically and to which extent different set-ups and the humidity of the inhaled air influence the VOC profile. Three different measuring set-ups were designed and three healthy control subjects were measured with each of them, using four devices of the same model (Cyranose 320™, Smiths Detection). The exhaled air was collected in a plastic bag. Either ambient air was used as reference (set-up Leipzig), or the reference air was humidified (100% relative humidity) (set-up Marburg and set-up Munich). In the set-up Marburg the subjects inhaled standardised medical air (Aer medicinalis Linde, AGA AB) out of a compressed air bottle through a demand valve; this air (after humidification) was also used as reference. In the set-up Leipzig the subjects inhaled VOC-filtered ambient air, in the set-up Munich unfiltered room air. The data were evaluated using either the real-time data or the changes in resistance as calculated by the device. The results were clearly dependent on the set-up. Apparently, humidification of the reference air could reduce the variance between devices, but this result was also dependent on the evaluation method used. When comparing the three subjects, the set-ups Munich and Marburg mapped these in a similar way, whereas not only the signals but also the variance of the set-up Leipzig were larger. Measuring VOCs with an electronic nose has not yet been standardised and the set-up significantly affects the results. As other researchers use further methods, it is currently not possible to draw generally accepted conclusions. More systematic tests are required to find the most sensitive and reliable but still feasible set-up so that comparability is improved. © Georg Thieme Verlag KG Stuttgart · New York.

A Numerical Study of Hydrodynamics and Sediment Transport in Fourleague Bay, Louisiana

NASA Astrophysics Data System (ADS)

Hu, K.; Chen, Q. J.; Xu, K.; Bentley, S. J.; WANG, J.

2017-12-01

Fourleague Bay is a shallow and vertically well-mixed estuary in south-central Louisiana. This estuary is highly impacted by wind (e.g., cold fronts and tropical storms), river discharge from the Atchafalaya River and tides from the Gulf of Mexico, and is being used as an analog site to study impacts of sediment-diversion restoration strategies in the Mississippi River Delta. In this study, a coupled flow-wave Delft3D model was setup and applied to study hydrodynamics and sediment transport in this area. The model grid size is 1071x631 with a 50-m resolution in the bay. Vegetation is considered by rigid cylinders in both flow and wave modules. The offshore water level boundary conditions were provided by a Gulf-scale Delft3D model. Model parameters, especially for cohesive sediment transport such as settling velocity, erosion rate and critical bottom shear stress, were calibrated using the field observation data during three seasons from May 2015 to March 2016. The modeled water levels, currents, significant wave heights and suspended sediment concentrations agreed fairly well with measurements, which suggests a reasonable model performance. Seasonal variations were analyzed based on different scenarios. A series of numerical experiments were set up to quantify the contributions of different factors, such as river discharge, tides and waves to sediment transport in this area. This model will be further applied to be part of a landscape ecosystem model to test landscape and population change over time with manipulations to sediment delivery. This study was funded by the National Science Foundation (SEES-1427389 and CCF-1539567).

What is the difference between a 2, 3, 4, or 5 °C world and how good are we at telling this difference? Results from ISI-MIP the first Inter-Sectoral Impact Model Intercomparison Project

NASA Astrophysics Data System (ADS)

Frieler, K.; Huber, V.; Piontek, F.; Schewe, J.; Serdeczny, O.; Warszawski, L.

2012-12-01

The Inter-sectoral Impact Model Intercomparison Project (ISI-MIP) aims to synthesize the state-of-the-art knowledge of climate change impacts at different levels of global warming. Over 25 climate impact modelling teams from around the world, working within the agriculture, water, biomes, infrastructure and health sectors, are collaborating to find answers to the question "What is the difference between a 2, 3, 4, or 5 °C world and how good are we at telling this difference?". The analysis is based on common, bias-corrected climate projections, and socio-economic pathways. The first, fast-tracked phase of the ISI-MIP has a focus on global impact models. The project's experimental design is formulated to distinguish the uncertainty introduced by the impact models themselves, from the inherent uncertainty in the climate projections and the variety of plausible socio-economic futures. Novel metrics, developed to emphasize societal impacts, will be used to identify regional 'hot-spots' of climate change impacts, as well as to quantify the cross-sectoral impact of the increasing frequency of extreme events in future climates. We present here first results from the Fast-Track phase of the project covering impact simulations in the biomes, agriculture and water sectors, in which the societal impacts of climate change are quantified for different levels of global warming. We also discuss the design of the scenario set-up and impact indicators chosen to suit the unique cross-sectoral, multi-model nature of the project.

Trophic cascades of bottom-up and top-down forcing on nutrients and plankton in the Kattegat, evaluated by modelling

NASA Astrophysics Data System (ADS)

Petersen, Marcell Elo; Maar, Marie; Larsen, Janus; Møller, Eva Friis; Hansen, Per Juel

2017-05-01

The aim of the study was to investigate the relative importance of bottom-up and top-down forcing on trophic cascades in the pelagic food-web and the implications for water quality indicators (summer phytoplankton biomass and winter nutrients) in relation to management. The 3D ecological model ERGOM was validated and applied in a local set-up of the Kattegat, Denmark, using the off-line Flexsem framework. The model scenarios were conducted by changing the forcing by ± 20% of nutrient inputs (bottom-up) and mesozooplankton mortality (top-down), and both types of forcing combined. The model results showed that cascading effects operated differently depending on the forcing type. In the single-forcing bottom-up scenarios, the cascade directions were in the same direction as the forcing. For scenarios involving top-down, there was a skipped-level-transmission in the trophic responses that was either attenuated or amplified at different trophic levels. On a seasonal scale, bottom-up forcing showed strongest response during winter-spring for DIN and Chl a concentrations, whereas top-down forcing had the highest cascade strength during summer for Chl a concentrations and microzooplankton biomass. On annual basis, the system was more bottom-up than top-down controlled. Microzooplankton was found to play an important role in the pelagic food web as mediator of nutrient and energy fluxes. This study demonstrated that the best scenario for improved water quality was a combined reduction in nutrient input and mesozooplankton mortality calling for the need of an integrated management of marine areas exploited by human activities.

Application of Particle Swarm Optimization in Computer Aided Setup Planning

NASA Astrophysics Data System (ADS)

Kafashi, Sajad; Shakeri, Mohsen; Abedini, Vahid

2011-01-01

New researches are trying to integrate computer aided design (CAD) and computer aided manufacturing (CAM) environments. The role of process planning is to convert the design specification into manufacturing instructions. Setup planning has a basic role in computer aided process planning (CAPP) and significantly affects the overall cost and quality of machined part. This research focuses on the development for automatic generation of setups and finding the best setup plan in feasible condition. In order to computerize the setup planning process, three major steps are performed in the proposed system: a) Extraction of machining data of the part. b) Analyzing and generation of all possible setups c) Optimization to reach the best setup plan based on cost functions. Considering workshop resources such as machine tool, cutter and fixture, all feasible setups could be generated. Then the problem is adopted with technological constraints such as TAD (tool approach direction), tolerance relationship and feature precedence relationship to have a completely real and practical approach. The optimal setup plan is the result of applying the PSO (particle swarm optimization) algorithm into the system using cost functions. A real sample part is illustrated to demonstrate the performance and productivity of the system.

Deepwater Horizon Oil-Protection Sand Berm and its Morphologic Interactions with a Natural Barrier Island: an Overview

NASA Astrophysics Data System (ADS)

Sallenger, A. H.; Plant, N. G.; Flocks, J.; Long, J. W.; Miselis, J. L.; Sherwood, C. R.; Hansen, M.; Nayegandhi, A.; Wright, W.

2011-12-01

After the Deepwater Horizon explosion and oil spill, Louisiana received permission to build a sand berm parallel to and offshore of the ~30-km-long Chandeleur Islands to capture floating oil and keep it from reaching mainland marshes. The berm was built with dredged sand to a height of approximately 2 m above mean sea level and within 100 m of the Gulf-side of the natural barrier island. Here, we update the status of the sand berm and how its morphology has evolved since construction began in June 2010. This is part of a study of morphologic change involving time series of airborne lidar topographic and bathymetric surveys, boat acoustic bathymetric surveys, satellite imagery, and modeling of sediment transport. Waves and sea level are being monitored with models and in-situ sensors. We will examine, as of our latest surveys, whether the introduction of new sand from the berm has significantly changed peak elevations, Dhigh, along the natural islands and hence changed island vulnerability to being overtopped by storm-driven water levels, such as still-water level (η, due to tides, surge, and wave setup) and runup (R, due to swash). Vulnerabilities to overwash, where R > Dhigh, and inundation, where η > Dhigh, will be identified. We will investigate the impacts on the berm and island of extra-tropical storms through June 2011 and tropical storms through the hurricane season of summer and early fall 2011. For example, during a storm in early January 2011, significant wave heights of 4.9 m generated runup on the berm where R > Dhigh. Four breaches were cut through the berm, the largest 590 m wide. This study provides a unique opportunity to investigate the wave and current transport of a large quantity of introduced sand and determine whether and how the sand nourishes a severely eroding barrier island.

Cloud effects on middle ultraviolet global radiation

NASA Technical Reports Server (NTRS)

Borkowski, J.; Chai, A.-T.; Mo, T.; Green, A. E. O.

1977-01-01

An Eppley radiometer and a Robertson-Berger sunburn meter are employed along with an all-sky camera setup to study cloud effects on middle ultraviolet global radiation at the ground level. Semiempirical equations to allow for cloud effects presented in previous work are compared with the experimental data. The study suggests a means of defining eigenvectors of cloud patterns and correlating them with the radiation at the ground level.

Dual-resolution dose assessments for proton beamlet using MCNPX 2.6.0

NASA Astrophysics Data System (ADS)

Chao, T. C.; Wei, S. C.; Wu, S. W.; Tung, C. J.; Tu, S. J.; Cheng, H. W.; Lee, C. C.

2015-11-01

The purpose of this study is to access proton dose distribution in dual resolution phantoms using MCNPX 2.6.0. The dual resolution phantom uses higher resolution in Bragg peak, area near large dose gradient, or heterogeneous interface and lower resolution in the rest. MCNPX 2.6.0 was installed in Ubuntu 10.04 with MPI for parallel computing. FMesh1 tallies were utilized to record the energy deposition which is a special designed tally for voxel phantoms that converts dose deposition from fluence. 60 and 120 MeV narrow proton beam were incident into Coarse, Dual and Fine resolution phantoms with pure water, water-bone-water and water-air-water setups. The doses in coarse resolution phantoms are underestimated owing to partial volume effect. The dose distributions in dual or high resolution phantoms agreed well with each other and dual resolution phantoms were at least 10 times more efficient than fine resolution one. Because the secondary particle range is much longer in air than in water, the dose of low density region may be under-estimated if the resolution or calculation grid is not small enough.

Length matters: Improved high field EEG-fMRI recordings using shorter EEG cables.

PubMed

Assecondi, Sara; Lavallee, Christina; Ferrari, Paolo; Jovicich, Jorge

2016-08-30

The use of concurrent EEG-fMRI recordings has increased in recent years, allowing new avenues of medical and cognitive neuroscience research; however, currently used setups present problems with data quality and reproducibility. We propose a compact experimental setup for concurrent EEG-fMRI at 4T and compare it to a more standard reference setup. The compact setup uses short EEG cables connecting to the amplifiers, which are placed right at the back of the head RF coil on a form-fitting extension force-locked to the patient MR bed. We compare the two setups in terms of sensitivity to MR-room environmental noise, interferences between measuring devices (EEG or fMRI), and sensitivity to functional responses in a visual stimulation paradigm. The compact setup reduces the system sensitivity to both external noise and MR-induced artefacts by at least 60%, with negligible EEG noise induced from the mechanical vibrations of the cryogenic cooling compression pump. The compact setup improved EEG data quality and the overall performance of MR-artifact correction techniques. Both setups were similar in terms of the fMRI data, with higher reproducibility for cable placement within the scanner in the compact setup. This improved compact setup may be relevant to MR laboratories interested in reducing the sensitivity of their EEG-fMRI experimental setup to external noise sources, setting up an EEG-fMRI workplace for the first time, or for creating a more reproducible configuration of equipment and cables. Implications for safety and ergonomics are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Model Predictive Control application for real time operation of controlled structures for the Water Authority Noorderzijlvest, The Netherlands

NASA Astrophysics Data System (ADS)

van Heeringen, Klaas-Jan; Gooijer, Jan; Knot, Floris; Talsma, Jan

2015-04-01

In the Netherlands, flood protection has always been a key issue to protect settlements against storm surges and riverine floods. Whereas flood protection traditionally focused on structural measures, nowadays the availability of meteorological and hydrological forecasts enable the application of more advanced real-time control techniques for operating the existing hydraulic infrastructure in an anticipatory and more efficient way. Model Predictive Control (MPC) is a powerful technique to derive optimal control variables with the help of model based predictions evaluated against a control objective. In a project for the regional water authority Noorderzijlvest in the north of the Netherlands, it has been shown that MPC can increase the safety level of the system during flood events by an anticipatory pre-release of water. Furthermore, energy costs of pumps can be reduced by making tactical use of the water storage and shifting pump activities during normal operating conditions to off-peak hours. In this way cheap energy is used in combination of gravity flow through gates during low tide periods. MPC has now been implemented for daily operational use of the whole water system of the water authority Noorderzijlvest. The system developed to a real time decision support system which not only supports the daily operation but is able to directly implement the optimal control settings at the structures. We explain how we set-up and calibrated a prediction model (RTC-Tools) that is accurate and fast enough for optimization purposes, and how we integrated it in the operational flood early warning system (Delft-FEWS). Beside the prediction model, the weights and the factors of the objective function are an important element of MPC, since they shape the control objective. We developed special features in Delft-FEWS to allow the operators to adjust the objective function in order to meet changing requirements and to evaluate different control strategies.

Rock fragment movement in shallow rill flow - A laboratory study

NASA Astrophysics Data System (ADS)

Becker, Kerstin; Wirtz, Stefan; Seeger, Manuel; Gronz, Oliver; Remke, Alexander; Iserloh, Thomas; Brings, Christine; Casper, Markus; Ries, Johannes B.

2014-05-01

Studies concerning rill erosion mainly deal with the erosion and transport of fine material. The transport of rock fragments is examined mostly for mountain rivers. But there are important differences between the conditions and processes in rivers and in rills: (1) In most cases, the river cuts into a coarse substrate, where fine material is sparse, whereas rill erosion occurs on arable land. So the main part of the substrate is fine material and only single rock fragments influence the processes. (2) In rivers, the water depth is relatively high. There are a lot of studies about hydraulic parameters in such flows, but there is almost nothing known about hydraulic conditions in surface runoff events of a few centimeters. Additionally, little information exists about the rock fragment movement as a part of rill erosion processes on arable land. This knowledge should be increased because rock fragments cause non-stationary water turbulences in rills, which enhance the erosive force of flowing water. Field experiments can only show the fact that a certain rock fragment has moved: The starting point and the final position can be estimated. But the moving path and especially the initiation of the movement is not detectable under field conditions. Hence, we developed a laboratory setup to analyze the movement of rock fragments depending on rock fragment properties (size, form), slope gradient, flow velocity and surface roughness. By observing the rock fragments with cameras from two different angles we are able (1) to measure the rotation angles of a rock fragment during the experiment and (2) to deduce different rock fragment movement patterns. On this poster we want to present the experimental setup, developed within the scope of a master thesis, and the results of these experiments.

Analysis of sewage sludge using an experimental prompt gamma neutron activation analysis (pgnaa) set-up with an am-be source

NASA Astrophysics Data System (ADS)

Idiri, Z.; Redjem, F.; Beloudah, N.

2016-09-01

An experimental PGNAA set-up using a 1 Ci Am-Be source has been developed and used for analysis of bulk sewage sludge samples issued from a wastewater treatment plant situated in an industrial area of Algiers. The sample dimensions were optimized using thermal neutron flux calculations carried out with the MCNP5 Monte Carlo Code. A methodology is then proposed to perform quantitative analysis using the absolute method. For this, average thermal neutron flux inside the sludge samples is deduced using average thermal neutron flux in reference water samples and thermal flux measurements with the aid of a 3He neutron detector. The average absolute gamma detection efficiency is determined using the prompt gammas emitted by chlorine dissolved in a water sample. The gamma detection efficiency is normalized for sludge samples using gamma attenuation factors calculated with the MCNP5 code for water and sludge. Wet and dehydrated sludge samples were analyzed. Nutritive elements (Ca, N, P, K) and heavy metals elements like Cr and Mn were determined. For some elements, the PGNAA values were compared to those obtained using Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma (ICP) methods. Good agreement is observed between the different values. Heavy element concentrations are very high compared to normal values; this is related to the fact that the wastewater treatment plant is treating not only domestic but also industrial wastewater that is probably rejected by industries without removal of pollutant elements. The detection limits for almost all elements of interest are sufficiently low for the method to be well suited for such analysis.

Neutron Tomography Using Mobile Neutron Generators for Assessment of Void Distributions in Thermal Hydraulic Test Loops

NASA Astrophysics Data System (ADS)

Andersson, P.; Bjelkenstedt, T.; Sundén, E. Andersson; Sjöstrand, H.; Jacobsson-Svärd, S.

Detailed knowledge of the lateral distribution of steam (void) and water in a nuclear fuel assembly is of great value for nuclear reactor operators and fuel manufacturers, with consequences for both reactor safety and economy of operation. Therefore, nuclear relevant two-phase flows are being studied at dedicated thermal-hydraulic test loop, using two-phase flow systems ranging from simplified geometries such as heated circular pipes to full scale mock-ups of nuclear fuel assemblies. Neutron tomography (NT) has been suggested for assessment of the lateral distribution of steam and water in such test loops, motivated by a good ability of neutrons to penetrate the metallic structures of metal pipes and nuclear fuel rod mock-ups, as compared to e.g. conventional X-rays, while the liquid water simultaneously gives comparatively good contrast. However, these stationary test loops require the measurement setup to be mobile, which is often not the case for NT setups. Here, it is acknowledged that fast neutrons of 14 MeV from mobile neutron generators constitute a viable option for a mobile NT system. We present details of the development of neutron tomography for this purpose at the division of Applied Nuclear Physics at Uppsala University. Our concept contains a portable neutron generator, exploiting the fusion reaction of deuterium and tritium, and a detector with plastic scintillator elements designed to achieveadequate spatial and energy resolution, all mounted in a light-weight frame without collimators or bulky moderation to allow for a mobile instrument that can be moved about the stationary thermal hydraulic test sections. The detector system stores event-to-event pulse-height information to allow for discrimination based on the energy deposition in the scintillator elements.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, T; Eldib, A; Hossain, M

Purpose: Patient in-vivo measurements report lower readings than those predicted from TMR-based treatment planning on TBI patient knees and ankles where rice was placed to fill the gap between patient’s legs. This study is to understand and correct the under dosage of Total Body Irradiation(TBI) with rice tissue equivalent bolus placement at TBI treatment patient setup. Methods: Bilateral TBI scheme was investigated with rice bags bolus placing between patient’s two legs acting as missing tissue. In-house TMR based treatment planning system was commissioned with measurements under TBI condition at 10MV, i.e. source-to-reference distance 383.4cm with 40×40cm field size with 1cmmore » thickness Lucite. Predictions of patient specific dose points are reported at different sites with 200cGy prescription at patient umbilicus point. Solid water and rice bag phantoms are used at TBI conditions for the attenuation factor verification and CT scanned to verify the CT number and electron density. Results: We found that the rice bag bolus overall density is 11% lower than the water; however, the attenuation factor of rice bags could become 15% lower than that of water at TBI condition. This overestimate of rice bag electron density could cause the lack of lateral scatter and the lack of backscatter. This could Result in an overestimate of dose at in-vivo dosimeter measurement points with TMR-based treatment planning systems. Observations of patient specific optically stimulated luminescent dosimeters(OSLDs) were used to confirm this overestimation. Measurements of setups with increasing the rice bag filled patient leg separation were performed to demonstrate eliminating the overdose issue. Conclusion: Rice bolus has a lower electron density than water does(11%) but results in 15% lower in attenuation factor at TBI condition. This effect was observed in patient delivery with OSLD measurements and can be corrected by increasing the filling rice bolus thickness with 15% longer of separation.« less

Plant Enhanced Bioremediation of Dissolved Toluene in Large Scale Column Setup

NASA Astrophysics Data System (ADS)

Basu, S.; Yadav, B. K.; Mathur, S.

2016-12-01

Hydrocarbons like BTEX compounds entering the soil-water system through anthropogenic activities can be long lasting sources of pollution, and thus, it is essential to look for remediation options that are environmentally benign. Bioremediation is a promising cost effective technique causing no harm to the contaminated ecosystem as compared to the traditional physicochemical methods. Natural microbes degrade contaminants from polluted soil water resources in bioremediation; however this process of natural bioremediation is quite slow under prevailing environmental conditions of a typical polluted site. Research has also proven that plants play an important role when it comes to accelerate the degradation rate cost-effectively in enhanced bioremediation technique. Thus in this study, fate and transport of dissolved toluene from a source zone to down-gradient receptors in a continuous soil-water plant system was investigated. For this, two sets of large scale column experiments were performed by connecting them with a treatment wetland having canna plants in first set and unplanted gravel bed in the second set. A continuous source of toluene contaminated water was supplied at the top of the column setups. A constant groundwater flow velocity of 0.625 cm/hr was maintained in the vertical direction. Free drainage was allowed at the bottom and a constant hydraulic head of 2.0 cm was maintained at the top boundary throughout the period of the experiments in both the cases. The observed microbial colonies using the plate counting method along with measured dissolved oxygen (DO) proved that the BTEX compound degraded aerobically at a faster rate in the first set. Plants played a positive role in enhancing biodegradation rate of the BTEX compound during its transport through the porous media. Finally the observed data of the column experiments were compared with the breakthrough curves obtained numerically solving the advection dispersion equation. The results of this research can be used to obtain vital information on framing the engineered bioremediation planning for contaminated sites.

HAI, a new airborne, absolute, twin dual-channel, multi-phase TDLAS-hygrometer: background, design, setup, and first flight data

NASA Astrophysics Data System (ADS)

Buchholz, Bernhard; Afchine, Armin; Klein, Alexander; Schiller, Cornelius; Krämer, Martina; Ebert, Volker

2017-01-01

The novel Hygrometer for Atmospheric Investigation (HAI) realizes a unique concept for simultaneous gas-phase and total (gas-phase + evaporated cloud particles) water measurements. It has been developed and successfully deployed for the first time on the German HALO research aircraft. This new instrument combines direct tunable diode laser absorption spectroscopy (dTDLAS) with a first-principle evaluation method to allow absolute water vapor measurements without any initial or repetitive sensor calibration using a reference gas or a reference humidity generator. HAI contains two completely independent dual-channel (closed-path, open-path) spectrometers, one at 1.4 and one at 2.6 µm, which together allow us to cover the entire atmospheric H2O range from 1 to 40 000 ppmv with a single instrument. Both spectrometers each comprise a separate, wavelength-individual extractive, closed-path cell for total water (ice and gas-phase) measurements. Additionally, both spectrometers couple light into a common open-path cell outside of the aircraft fuselage for a direct, sampling-free, and contactless determination of the gas-phase water content. This novel twin dual-channel setup allows for the first time multiple self-validation functions, in particular a reliable, direct, in-flight validation of the open-path channels. During the first field campaigns, the in-flight deviations between the independent and calibration-free channels (i.e., closed-path to closed-path and open-path to closed-path) were on average in the 2 % range. Further, the fully autonomous HAI hygrometer allows measurements up to 240 Hz with a minimal integration time of 1.4 ms. The best precision is achieved by the 1.4 µm closed-path cell at 3.8 Hz (0.18 ppmv) and by the 2.6 µm closed-path cell at 13 Hz (0.055 ppmv). The requirements, design, operation principle, and first in-flight performance of the hygrometer are described and discussed in this work.

Gas-solid carbonation as a current alternative origin for carbonates in Martian regolith

NASA Astrophysics Data System (ADS)

Garenne, A.; Montes-Hernandez, G.; Beck, P.; Schmitt, B.; Brissaud, O.

2011-12-01

Carbonates are abundant sedimentary minerals at the surface and sub-surface of Earth and they have been proposed as tracers of liquid water in extraterrestrial environments (e.g. at Mars surface). Its formation mechanism is since generally associated with aqueous alteration processes. Recently, carbonates minerals have been discovered on Mars surface by different orbital or rovers missions. In particular, the phoenix mission has measured from 1 to 5% of calcium carbonate (calcite type). These occurrences have been reported in area were the relative humidity is significantly high (Boynton et al., 2009). The small concentration of carbonates suggests an alternative process than carbonation in aqueous conditions. Such an observation might rather point toward a possible formation mechanism by dust-gas reaction under current Martian conditions. For this reason, in the present study, we designed an experimental setup consisting of an infrared microscope coupled to a cryogenic reaction cell (IR-CryoCell setup) in order to investigate the gas-solid carbonation of three different mineral precursors for carbonates (Ca and Mg hydroxides, and a hydrated Ca silicate formed from Ca2SiO4) at low temperature (from -10 to 25°C) and at reduced CO2 pressure (from 100 to 1000 mbar). These mineral materials are crucial precursors to form respective Ca and Mg carbonates in humid environments (0 < relative humidity < 100%) at dust-CO2 or dust-water ice-CO2 interfaces. The results have revealed a significant and fast carbonation process for Ca hydroxide and hydrated Ca silicate. Conversely, slight carbonation process was observed for Mg hydroxide. These results suggest that gas-solid carbonation process or carbonate formation at the dust-water ice-CO2 interfaces could be a currently active Mars surface process. We note that the carbonation process at low temperature (<0°C) described in the present study could also have important implications on the dust-water ice-CO2 interactions in cold terrestrial environments (e.g. Antarctic).

Design and use of a sparged platform for energy flux measurements over lakes

NASA Astrophysics Data System (ADS)

Gijsbers, S.; Wenker, K.; van Emmerik, T.; de Jong, S.; Annor, F.; Van De Giesen, N.

2012-12-01

Energy flux measurements over lakes or reservoirs demand relatively stable platforms. Platforms can not be stabilized by fixing them on the bottom of the lake when the water body is too deep or when water levels show significant fluctuations. We present the design and first operational results of a sparged platform. The structure consists of a long PVC pipe, the sparge, which is closed at the bottom. On the PVC pipe rests an aluminum frame platform that carries instrumentation and solar power panel. In turn, the platform rests partially on a large inflated tire. At the bottom of the PVC pipe, lead weights and batteries were placed to ensure a very low point of gravity to minimize wave impact on the platform movement. The tire ensures a large second moment of the water plane. The overall volume of displacement is small in this sparged design. The combination of large second momentum of the water plane and small displacement ensure a high placement of the metacenter. The distance between the point of gravity and the metacenter is relatively long and the weight is large due to the weights and batteries. This ensures that the eigenfrequency of the platform is very low. The instrumentation load consisted of a WindMaster Pro (sonic anemometer for 3D wind speed and air temperature to perform eddy covariance measurements of sensible heat flux), a NR Lite (net radiometer), and air temperature and relative humidity sensors. The platform had a wind vane and the sparge could turn freely around its anchor cable to ensure that the anemometer always faced upwind. A compass in the logger completed this setup. The stability was measured with an accelerometer. In addition to the design and its stability, some first energy flux results will be presented.

Two-Phase Flow Model and Experimental Validation for Bubble Augmented Waterjet Propulsion Nozzle

NASA Astrophysics Data System (ADS)

Choi, J.-K.; Hsiao, C.-T.; Wu, X.; Singh, S.; Jayaprakash, A.; Chahine, G.

2011-11-01

The concept of thrust augmentation through bubble injection into a waterjet has been the subject of many patents and publications over the past several decades, and there are simplified computational and experimental evidence of thrust increase. In this work, we present more rigorous numerical and experimental studies which aim at investigating two-phase water jet propulsion systems. The numerical model is based on a Lagrangian-Eulerian method, which considers the bubbly mixture flow both in the microscopic level where individual bubble dynamics are tracked and in the macroscopic level where bubbles are collectively described by the local void fraction of the mixture. DYNAFLOW's unsteady RANS solver, 3DYNAFS-Vis is used to solve the macro level variable density mixture medium, and a fully unsteady two-way coupling between this and the bubble dynamics/tracking code 3DYNAFS-DSM is utilized. Validation studies using measurements in a half 3-D experimental setup composed of divergent and convergent sections are presented. Visualization of the bubbles, PIV measurements of the flow, bubble size and behavior are observed, and the measured flow field data are used to validate the models. Thrust augmentation as high as 50% could be confirmed both by predictions and by experiments. This work was supported by the Office of Naval Research under the contract N00014-07-C-0427, monitored by Dr. Ki-Han Kim.

Neutrinoless double beta decay in Gerda

NASA Astrophysics Data System (ADS)

Grabmayr, Peter; Gerda Collaboration

2015-10-01

The Germanium Detector Array (Gerda) experiment searches for the neutrinoless double beta decay in 76Ge. This lepton number violating process is predicted by extensions of the standard model. Gerda follows a staged approach by increasing mass and lowering the background level from phase to phase. Gerda is setup at the Gran Sasso underground laboratory of INFN, Italy. An array of high-purity germanium detectors is lowered directly in liquid argon for shielding and cooling. Further background reduction is achieved by an instrumented water buffer. In Phase I an exposure of 21.6 kg yr was collected at a background level of 10-2 cts/(keV kg yr). The lower limit on the half-life of 76Ge > 2 . 1 .1025 yr (90% C.L.) has been published. Further analyses search for decay into excited states or the accompanied Majoron decay. Presently, Phase II is in preparation which intends to reach a background level of 10-3 cts/(keV kg yr) and to increase the exposure to 100 kg yr. About 20 kg of novel thick-window BEGe (Broad Energy Germanium) detectors will be added and the liquid argon will be instrumented. The status of Phase II preparation and results from the commissioning runs will be presented as well as some further results from Phase I.

BRICK v0.2, a simple, accessible, and transparent model framework for climate and regional sea-level projections

NASA Astrophysics Data System (ADS)

Wong, Tony E.; Bakker, Alexander M. R.; Ruckert, Kelsey; Applegate, Patrick; Slangen, Aimée B. A.; Keller, Klaus

2017-07-01

Simple models can play pivotal roles in the quantification and framing of uncertainties surrounding climate change and sea-level rise. They are computationally efficient, transparent, and easy to reproduce. These qualities also make simple models useful for the characterization of risk. Simple model codes are increasingly distributed as open source, as well as actively shared and guided. Alas, computer codes used in the geosciences can often be hard to access, run, modify (e.g., with regards to assumptions and model components), and review. Here, we describe the simple model framework BRICK (Building blocks for Relevant Ice and Climate Knowledge) v0.2 and its underlying design principles. The paper adds detail to an earlier published model setup and discusses the inclusion of a land water storage component. The framework largely builds on existing models and allows for projections of global mean temperature as well as regional sea levels and coastal flood risk. BRICK is written in R and Fortran. BRICK gives special attention to the model values of transparency, accessibility, and flexibility in order to mitigate the above-mentioned issues while maintaining a high degree of computational efficiency. We demonstrate the flexibility of this framework through simple model intercomparison experiments. Furthermore, we demonstrate that BRICK is suitable for risk assessment applications by using a didactic example in local flood risk management.

An analogue conceptual rainfall-runoff model for educational purposes

NASA Astrophysics Data System (ADS)

Herrnegger, Mathew; Riedl, Michael; Schulz, Karsten

2016-04-01

Conceptual rainfall-runoff models, in which runoff processes are modelled with a series of connected linear and non-linear reservoirs, remain widely applied tools in science and practice. Additionally, the concept is appreciated in teaching due to its somewhat simplicity in explaining and exploring hydrological processes of catchments. However, when a series of reservoirs are used, the model system becomes highly parametrized and complex and the traceability of the model results becomes more difficult to explain to an audience not accustomed to numerical modelling. Since normally the simulations are performed with a not visible digital code, the results are also not easily comprehensible. This contribution therefore presents a liquid analogue model, in which a conceptual rainfall-runoff model is reproduced by a physical model. This consists of different acrylic glass containers representing different storage components within a catchment, e.g. soil water or groundwater storage. The containers are equipped and connected with pipes, in which water movement represents different flow processes, e.g. surface runoff, percolation or base flow. Water from a storage container is pumped to the upper part of the model and represents effective rainfall input. The water then flows by gravity through the different pipes and storages. Valves are used for controlling the flows within the analogue model, comparable to the parameterization procedure in numerical models. Additionally, an inexpensive microcontroller-based board and sensors are used to measure storage water levels, with online visualization of the states as time series data, building a bridge between the analogue and digital world. The ability to physically witness the different flows and water levels in the storages makes the analogue model attractive to the audience. Hands-on experiments can be performed with students, in which different scenarios or catchment types can be simulated, not only with the analogue but also in parallel with the digital model, thereby connecting real-world with science. The effects of different parameterization setups, which is important not only in hydrological sciences, can be shown in a tangible way. The use of the analogue model in the context of "children meet University" events seems an attractive approach to show a younger audience the basic ideas of catchment modelling concepts, which would otherwise not be possible.

Two-dimensional numerical modelling of sediment and chemical constituent transport within the lower reaches of the Athabasca River.

PubMed

Kashyap, Shalini; Dibike, Yonas; Shakibaeinia, Ahmad; Prowse, Terry; Droppo, Ian

2017-01-01

Flows and transport of sediment and associated chemical constituents within the lower reaches of the Athabasca River between Fort McMurray and Embarrass Airport are investigated using a two-dimensional (2D) numerical model called Environmental Fluid Dynamics Code (EFDC). The river reach is characterized by complex geometry, including vegetated islands, alternating sand bars and an unpredictable thalweg. The models were setup and validated using available observed data in the region before using them to estimate the levels of cohesive sediment and a select set of chemical constituents, consisting of polycyclic aromatic hydrocarbons (PAHs) and metals, within the river system. Different flow scenarios were considered, and the results show that a large proportion of the cohesive sediment that gets deposited within the study domain originates from the main stem upstream inflow boundary, although Ells River may also contribute substantially during peak flow events. The floodplain, back channels and islands in the river system are found to be the major areas of concern for deposition of sediment and associated chemical constituents. Adsorbed chemical constituents also tend to be greater in the main channel water column, which has higher levels of total suspended sediments, compared to in the flood plain. Moreover, the levels of chemical constituents leaving the river system are found to depend very much on the corresponding river bed concentration levels, resulting in higher outflows with increases in their concentration in the bed sediment.

SU-F-T-185: Study of the Robustness of a Proton Arc Technique Based On PBS Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Z; Zheng, Y

Purpose: One potential technique to realize proton arc is through using PBS beams from many directions to form overlaid Bragg peak (OBP) spots and placing these OBP spots throughout the target volume to achieve desired dose distribution. In this study, we analyzed the robustness of this proton arc technique. Methods: We used a cylindrical water phantom of 20 cm in radius in our robustness analysis. To study the range uncertainty effect, we changed the density of the phantom by ±3%. To study the setup uncertainty effect, we shifted the phantom by 3 & 5 mm. We also combined the rangemore » and setup uncertainties (3mm/±3%). For each test plan, we performed dose calculation for the nominal and 6 disturbed scenarios. Two test plans were used, one with single OBP spot and the other consisting of 121 OBP spots covering a 10×10cm{sup 2} area. We compared the dose profiles between the nominal and disturbed scenarios to estimate the impact of the uncertainties. Dose calculation was performed with Gate/GEANT based Monte Carlo software in cloud computing environment. Results: For each of the 7 scenarios, we simulated 100k & 10M events for plans consisting of single OBP spot and 121 OBP spots respectively. For single OBP spot, the setup uncertainty had minimum impact on the spot’s dose profile while range uncertainty had significant impact on the dose profile. For plan consisting of 121 OBP spots, similar effect was observed but the extent of disturbance was much less compared to single OBP spot. Conclusion: For PBS arc technique, range uncertainty has significantly more impact than setup uncertainty. Although single OBP spot can be severely disturbed by the range uncertainty, the overall effect is much less when a large number of OBP spots are used. Robustness optimization for PBS arc technique should consider range uncertainty with priority.« less

Evaluation of transverse dispersion effects in tank experiments by numerical modeling: parameter estimation, sensitivity analysis and revision of experimental design.

PubMed

Ballarini, E; Bauer, S; Eberhardt, C; Beyer, C

2012-06-01

Transverse dispersion represents an important mixing process for transport of contaminants in groundwater and constitutes an essential prerequisite for geochemical and biodegradation reactions. Within this context, this work describes the detailed numerical simulation of highly controlled laboratory experiments using uranine, bromide and oxygen depleted water as conservative tracers for the quantification of transverse mixing in porous media. Synthetic numerical experiments reproducing an existing laboratory experimental set-up of quasi two-dimensional flow through tank were performed to assess the applicability of an analytical solution of the 2D advection-dispersion equation for the estimation of transverse dispersivity as fitting parameter. The fitted dispersivities were compared to the "true" values introduced in the numerical simulations and the associated error could be precisely estimated. A sensitivity analysis was performed on the experimental set-up in order to evaluate the sensitivities of the measurements taken at the tank experiment on the individual hydraulic and transport parameters. From the results, an improved experimental set-up as well as a numerical evaluation procedure could be developed, which allow for a precise and reliable determination of dispersivities. The improved tank set-up was used for new laboratory experiments, performed at advective velocities of 4.9 m d(-1) and 10.5 m d(-1). Numerical evaluation of these experiments yielded a unique and reliable parameter set, which closely fits the measured tracer concentration data. For the porous medium with a grain size of 0.25-0.30 mm, the fitted longitudinal and transverse dispersivities were 3.49×10(-4) m and 1.48×10(-5) m, respectively. The procedures developed in this paper for the synthetic and rigorous design and evaluation of the experiments can be generalized and transferred to comparable applications. Copyright © 2012 Elsevier B.V. All rights reserved.

SU-F-T-509: Investigation into the Impact of the Linear Accelerator Treatment Table On Skin Dose to Prone Breast Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pedersen, K; Irwin, J; Sansourekidou, P

Purpose: To investigate the impact of the treatment table on skin dose for prone breast patients for which the breast contacts the table and to develop a method to decrease skin dose. Methods: We used 12cm stack of 15cmx15cm solid water slabs to imitate breast. Calibrated EBT3 radiochromic film was affixed to the bottom of the phantom. Treatments for 32 patients were analyzed to determine typical prone breast beam parameters. Based on the analysis, a field size and a range of gantry angles were chosen for the test beams. Three experimental setups were used. The first represented the patient setupmore » currently used in our clinics with the phantom directly on the table. The second was the skin sparing setup, with a 1.5cm Styrofoam slab between the phantom and the table. The third used a 7.5cm Styrofoam slab to examine the extent of skin sparing potential. The calibration curve was applied to each film to determine dose. Percent difference in dose between the current and skin sparing setups was calculated for each gantry angle and gantry angle pair. Results: Data showed that beams entering through the table showed a skin dose decrease ranging from 13%–30% with the addition of 7.5cm Styrofoam, while beams exiting through the table showed no significant difference. The addition of 1.5cm Styrofoam resulted in differences ranging from 0.5%–13% with the skin sparing setup. Conclusion: The results demonstrate that skin in contact with the table receives increased dose from beams entering through the table. By creating separation between the breast and the table with Styrofoam the skin dose can be lowered, but 1.5 cm did not fully mitigate the effect. Further investigation will be performed to identify a clinically practical thickness that maximizes this mitigation.« less

Experimental and Theoretical Probing of Molecular Dynamics at Catalytic and Ionic Liquid Interfaces

DTIC Science & Technology

2014-04-01

15. SUBJECT TERMS Surface, interface,  photocatalysis , fluorescence yield, ionic liquid, reactive force field    16. SECURITY CLASSIFICATION OF: 17...2, 3 which are promising photocatalysts for hydrogen production via photocatalytic water splitting. 1. Experimental The new experimental setup...Wang, G. Liu, G. Q. Lu, H.-M. Cheng, Int. J. of Hydrogen Energ., 2010, 35, 8199- 8205. 3. F. Xu, Y. Yuan, H. Han, D. Wu, Z. Gao, K. Jiang, CrystEngComm

The Energy Under Our Feet: A Study of Solar Radiation

NASA Astrophysics Data System (ADS)

Weiss, I.

2016-12-01

In this experiment I tested if asphalt pavement can produce enough solar heat to produce energy through a system that uses water, solar energy and heat. A setup that can conserve the water and prevent it from evaporating, as well as measuring the energy production is required to run this experiment. I have done a lot of research on this experiment and found that there are several variables that impact the results of this experiment. 1. The surface temperature compared to the air temperature 2. The Geographical location of the pavement 3. The time of the year 4. Cloud coverage for the day Overall there will be many variables I will have to keep out of the experiment such as temperature ranges, season changes and geographical location. My constant will be my location at 33.7086o North and 117.9564o West. Asphalt pavements do not reflect the sunlight and hence heat up faster than a light surface that would reflect the sunlight. This means the Asphalt absorbs the solar radiation, which increases the temperature of the air around the asphalt contributing to what is known as the urban heat island effect. This heating in turn contributes to the formation of smog and ozone products. With the population still growing this would also mean an increase in this temperature and hence an increase in smog and ozone, creating a significant health concern. Cities need to start looking at ways to cool their pavement and find ways to harvest the energy created by their streets. Installing pipes with water can provide that solution and not only reduce the heat reflected from the pavement but also harvest energy from this setup, and decrease the smog production and maintain a balance in ozone levels. As well as the asphalt needed to run the testing, a Stirling engine is required. A Stirling Engine is a highly efficient engine that can run on a variety of heat sources. Because it is highly compatible with alternative energy and renewable energy sources it could become increasingly significant as the cost of fuel keeps rising. One additional item I researched was the Solar Noon. This is the data that provides us with the best angle of the sun onto our pavement and the timeframe that would give us the highest concentration of solar radiation. For the testing location at my home the Solar Noon data was calculated on http://susdesign.com/sunangle.

Spray characterization of ULV sprayers typically used in vector control

USDA-ARS?s Scientific Manuscript database

Numerous spray machines are used to apply products for the control of human disease vectors, such as mosquitoes and flies. However, the selection and setup of these machines significantly affect the level of control achieved during an application. The droplet spectra produced by nine different ULV...

Promoting Chemistry at the Elementary Level: A Low-Maintenance Program of Chemical Demonstrations.

ERIC Educational Resources Information Center

Louters, Larry L.; Huisman, Richard D.

1999-01-01

Presents a chemical demonstration program designed to support elementary science education in which fifth- and sixth-grade students visit a college campus to watch chemical demonstrations performed by a professor. Contains suggestions for program set-up and references for demonstrations to use. (WRM)

Getting Shocks: Teaching Secondary School Physics through History.

ERIC Educational Resources Information Center

Heering, Peter

2000-01-01

Uses several replicas of experimental set-ups that were originally used in electrostatic research in teaching electrostatics through history on secondary school level. Makes visible the change of the style of electrostatic experimentation that took place at the end of the 18th century. (Contains 25 references.) (ASK)

Millikan Movies

ERIC Educational Resources Information Center

Zou, Xueli; Dietz, Eric; McGuire, Trevor; Fox, Louise; Norris, Tiara; Diamond, Brendan; Chavez, Ricardo; Cheng, Stephen

2008-01-01

Since Robert Millikan discovered the quantization of electric charge and measured its fundamental value over 90 years ago, his oil-drop experiment has become essential in physics laboratory classes at both the high school and college level. As physics instructors, however, many of us have used the traditional setup and experienced the tedium of…

A Biosafety Level 2 Virology Lab for Biotechnology Undergraduates

ERIC Educational Resources Information Center

Matza-Porges, Sigal; Nathan, Dafna

2017-01-01

Medical, industrial, and basic research relies heavily on the use of viruses and vectors. Therefore, it is important that bioscience undergraduates learn the practicalities of handling viruses. Teaching practical virology in a student laboratory setup presents safety challenges, however. The aim of this article is to describe the design and…

TERENO-MED: Terrestrial Environmental Observatories in the Mediterranean Region

NASA Astrophysics Data System (ADS)

Krueger, Elisabeth; Friesen, Jan; Kallioras, Andreas; Bogena, Heye; Devaraju, Anusuriya; Vereecken, Harry; Teutsch, Georg

2013-04-01

The Mediterranean region is one of the most imperilled regions in the world concerning present and future water scarcity. The region is delicately positioned at the crossroads between East and West, interlinking Europe, Asia and Africa. Societal and economic changes causing population growth, industrialisation and urbanisation lead to significant increases in food, water and energy demand. Hence, natural resources, such as water and soils, as well as ecosystems are put under pressure and water availability and quality will be severely affected in the future. At the same time, climate and extreme event projections from climate models for the Mediterranean are, unlike for most regions worldwide, consistent in their trends based on various scenarios. This consistency in the model predictions shows that the Mediterranean will face some of the most severe increases in dryness worldwide (based on consecutive dry days and soil moisture), and indicate a decrease of up to 50 % in available water resources within the next 50-100 years. These developments are accentuated by the fact that in many of the Mediterranean countries, natural renewable water resources are fully exploited or over-exploited already today, mainly due to agricultural irrigation, but also touristic activities. At the same time, the Mediterranean region is a global hot spot of freshwater biodiversity, with a high proportion of endemic and endangered species. While trend projections for water availability and climate change derived from global studies are consistent, regional patterns and heterogeneities, as well as local adaptation measures will largely determine the functioning of societies and the health of ecosystems. However, a lack of environmental data prohibits the development of sustainable adaptation measures to water scarcity on a scientific basis. Building on the experiences gained in the national TERENO network, a Mediterranean observatory network will be set-up, coordinated by two Helmholtz Centres and jointly operated with local partners across the Mediterranean region. In a number of Mediterranean mesoscale hydrological catchments TERENO-MED will investigate the long-term effects of global change on the quality and the dynamics of water resources in human-influenced environments under water scarcity. The Helmholtz Centres UFZ (overall coordinator) and FZJ have therefore initiated the set-up of a network of global change observatories in 5-10 Mediterranean river catchments. The TERENO-MED observatories will: - investigate societally relevant water problems in the context of 'typical' Mediterranean environments, - provide long-term and quality-controlled data available to the scientific community, - be operated and maintained through local research institutes and universities, - establish common monitoring platforms and foster synergies between research organizations, - provide solutions to pressing local and regional water problems by building partnerships between scientific partners and regional authorities.

Geodesic and hydrogeophysic long term observations in the Durzon karstic aquifer (Larzac, France)

NASA Astrophysics Data System (ADS)

Le Moigne, Nicolas; Bayer, Roger; Boudin, Frederick; Champollion, Cedric; Chery, Jean; Collard, Philippe; Daignières, Marc; Deville, Sabrina; Doerflinger, Erik; Vernant, Philippe

2010-05-01

Karsts are generally characterized by high heterogeneity at all scales for both the water storage properties and the mode of water transport. The Durzon karst system is located in south of France and is characterized by a unsaturated zone of 100-150 m width. The water input is exclusively rainfall and draining occurs at the Durzon perennial spring in a karstic valley. The Durzon aquifer has been monitored by our group by different geophysical methods (gravimetry, tiltmetry, more details below) for several years. The present-day stage of the project is to setup long term observations to assess hydrological properties of the karst in a small area of 500m*500m with numerous caves (up to 100 m deep and more than 2 km of development). The observations are of four major types: - Continuous high frequency and high accuracy gravimetry: Gravimetric observations can be directly linked to the variations of water masses in the unsaturated zone. The iGrav™ Superconducting Gravity Meter from GWR (San Diego, USA) will be used to record continuous gravity variations and track water mass variations at a few millimeters level. The iGrav™ is a new SG model from GWR that has been simplified for portable and field operation, but retains the stability and precision of previous SGs. With a drift rate of less than 0.5 microGal/month and a virtually constant scale factory, the iGrav™ will provide a much higher stability and precision than can be achieved with mechanical spring-type gravity meters. - Water flux measurements (atmospheric and in-situ): A flux tower provides evapo-transpiration measurements (output) allowing complete budget calculation with the help of gravity (storage variations) and rainfall (input). An original measurement corresponds to the measure of the in-situ flow inside karstic caves (stalactites and underground river). - Tiltmetry: In situ (in caves) measurements are completed by long base silica tiltmeters. Tiltmeters are sensible to water storage in fractures and provide another type of transfer observation with long term measurements recording. - Repeated hydro-geophysical methods (Resonance Magnetic Protonic, electric resistivity, seismic reflection): Repeated ground and boreholes electric resistivity measurements can be interpreted as a function of water saturation in the unsaturated zone and is perfectly complementary with Resonance Magnetic Protonic (RMP) which measures vertical profiles of water content. All the observations are used to constrained simple physical models of water transfer in the unsaturated zone of the karst. New observations as gravimetry, RMP or in-situ flow measurements are crucial to distinguish between different physical models and establish the level of heterogeneity of the water transfer. The observatory will be fully operational for the winter 2010 and welcomes collaborations. All data will be made publically available through the OREME and ORE H+ web services.