Comparison of upconing under vertical and horizontal wells in freshwater lenses: sand-box experiments and numerical modeling

NASA Astrophysics Data System (ADS)

Stoeckl, Leonard; Stefan, Loeffler; Houben, Georg

2013-04-01

Freshwater lenses on islands and in inland areas are often the primary freshwater resource there. The fragile equilibrium between saline and fresh groundwater can be disrupted by excessive pumping, leading to an upward migration of the saline water underneath the well. Sand-box experiments were conducted to compare the upconing at vertical and horizontal wells pumping from a freshwater lens. Results were then compared to numerical simulations. To simulate the cross-section of an "infinite strip island", an acrylic box with a spacing of 5 cm was filled with coarse sand. After saturating the model with degassed saltwater from bottom to top, freshwater recharge was applied from above. By coloring the infiltrating freshwater with different tracer colors using uranine and indigotine we were able to visualize flow paths during pumping. A horizontal and a vertical well were placed at the left and right side of the symmetric island. Both had equal diameter, screen length, depth of placement, and distance to shore. Three increasing pumping rates were applied to each well successively and the electrical conductivity of the abstracted water was continuously measured using a through-flow cell. Results show that no saltwater entered the wells when pumping at the lowest rate. Still, slight saltwater upconing and a shift of the freshwater divide in the island were observed. At the second rate a clear saltwater breakthrough into the vertical well occurred, while the electrical conductivity remained nearly unchanged in the horizontal well. Applying the third (highest) abstraction rate to each of the wells saltwater entered both wells, exceeding drinking water standards in the vertical well. The described behavior indicates the advantage of horizontal over vertical wells on islands and in coastal zones prone to saltwater up-coning. Numerical simulations show similar patterns, even though deviations exist between the second and the third pumping rate, which are under and overestimated by the numerical simulation, respectively. Further investigations are necessary to investigate the dynamics of pumping from freshwater lenses under the influence of climate change (i.e. sea level rise).

Disposable sludge dewatering container and method

DOEpatents

Cole, Clifford M.

1993-01-01

A device and method for preparing sludge for disposal comprising a box with a thin layer of gravel on the bottom and a thin layer of sand on the gravel layer, an array of perforated piping deployed throughout the gravel layer, and a sump in the gravel layer below the perforated piping array. Standpipes connect the array and sump to an external ion exchanger/fine particulate filter and a pump. Sludge is deposited on the sand layer and dewatered using a pump connected to the piping array, topping up with more sludge as the aqueous component of the sludge is extracted. When the box is full and the free standing water content of the sludge is acceptable, the standpipes are cut and sealed and the lid secured to the box.

78 FR 46315 - Foreign-Trade Zone (FTZ) 247-Erie, Pennsylvania, Notification of Proposed Production Activity, GE...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-31

...; cover assemblies; strainer assemblies; oil filter assemblies; air filter assemblies; screen assemblies; filter assemblies; breather assemblies; filter box assemblies; sand trap assemblies; valve stems; brake... holders; staples; rivets; brazing alloys; diesel engines; frame assemblies; air inlets; filter box air...

Salt tectonics in an experimental turbiditic tank

NASA Astrophysics Data System (ADS)

Sellier, Nicolas; Vendeville, Bruno

2010-05-01

We modelled the effect of the deposition of clastic sediments wedges along passive margin by combining two different experimental approaches. The first approach, which uses flume experiments in order to model turbiditic transport and deposition, had focused, so far mainly on the stratigraphic architecture and flow properties. But most experiments have not accounted for the impact of syndepositional deformation. The second approach is the classic tectonic modelling (sand-box experiments) is aimed essentially at understanding deformation, for example the deformation of a sediment wedge deposited onto a mobile salt layer. However, with this approach, the sediment transport processes are crudely modelled by adding each sediment layer uniformly, regardless of the potential influence of the sea-floor bathymetry on the depositional pattern. We designed a new tectono-stratigraphic modelling tank, which combines modelling of the turbiditic transport and deposition, and salt-related deformation driven by sediment loading. The set-up comprises a channel connected to a main water tank. A deformation box is placed at the mouth of the channel, on the base of the tank. The base of the box can be filled with various kinds of substrates either rigid (sand) or viscous (silicone polymer, simulating mobile salt layer having varying length and thickness). A mixture of fine-grained powder and water is maintained in suspension in a container, and then released and channelled toward the basin, generating an analogue of basin-floor fans or lobes. We investigated the effect of depositing several consecutive turbiditic lobes on the deformation of the salt body and its overburden. The dynamics of experimental turbidity currents lead to deposits whose thickness varied gradually laterally: the lobe is thick in the proximal region and thins progressively distally, thus creating a very gentle regional surface slope. As the fan grows by episodic deposition of successive turbiditic lobes, the model deforms spontaneously by vertical collapse and lateral spreading of the entire overburden. We conducted a series of systematic experiments varying the length and thickness of the salt body, as well as the sediment input and nature.

77 FR 55224 - Notice of Availability of the Proposed Imperial Sand Dunes Recreation Area Management Plan and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-07

...: Regular Mail: BLM Director (210), Attention: Brenda Hudgens- Williams, P.O. Box 71383, Washington, DC 20024-1383. Overnight Mail: BLM Director (210), Attention: Brenda Hudgens- Williams, 20 M Street SE...; and visual resources. The Proposed Imperial Sand Dunes RAMP and CDCA Plan Amendment/Final EIS includes...

Children's Worlds: An Exploration of Latino Students' Play in Rural New Mexico

ERIC Educational Resources Information Center

Ulibarri, Reyna M.

2016-01-01

I present an ethnographic study of thirteen nine-year-old, U.S.-born Latino children in rural New Mexico. I employ in-depth individual and group interviews, participant observation, and sand play (a method borrowed from clinical psychology in which children "make a world" in a box of sand) to explore how play interactions represent,…

Bioturbation, advection, and diffusion of a conserved tracer in a laboratory flume

NASA Astrophysics Data System (ADS)

Work, P. A.; Moore, P. R.; Reible, D. D.

2002-06-01

Laboratory experiments indicating the relative influences of advection, diffusion, and bioturbation on transport of NaCl tracer between a stream and streambed are described. Data were collected in a recirculating flume housing a box filled with test sediments. Peclet numbers ranged from 0 to 1.5. Sediment components included a medium sand (d50 = 0.31 mm), kaolinite, and topsoil. Lumbriculus variegatus were introduced as bioturbators. Conductivity probes were employed to document the flux of the tracer solution out of the bed. Measurements are compared to one-dimensional effective diffusion models assuming one or two horizontal sediment layers. These simple models provide a good indication of tracer half-life in the bed if a suitable effective diffusion coefficient is chosen but underpredict initial flux and overpredict flux at long times. Organism activity was limited to the upper reaches of the sediment test box but eventually exerts a secondary influence on flux from deeper regions.

Seismic wave propagation in granular media

NASA Astrophysics Data System (ADS)

Tancredi, Gonzalo; López, Francisco; Gallot, Thomas; Ginares, Alejandro; Ortega, Henry; Sanchís, Johnny; Agriela, Adrián; Weatherley, Dion

2016-10-01

Asteroids and small bodies of the Solar System are thought to be agglomerates of irregular boulders, therefore cataloged as granular media. It is a consensus that many asteroids might be considered as rubble or gravel piles.Impacts on their surface could produce seismic waves which propagate in the interior of these bodies, thus causing modifications in the internal distribution of rocks and ejections of particles and dust, resulting in a cometary-type comma.We present experimental and numerical results on the study of propagation of impact-induced seismic waves in granular media, with special focus on behavior changes by increasing compression.For the experiment, we use an acrylic box filled with granular materials such as sand, gravel and glass spheres. Pressure inside the box is controlled by a movable side wall and measured with sensors. Impacts are created on the upper face of the box through a hole, ranging from free-falling spheres to gunshots. We put high-speed cameras outside the box to record the impact as well as piezoelectic sensors and accelerometers placed at several depths in the granular material to detect the seismic wave.Numerical simulations are performed with ESyS-Particle, a software that implements the Discrete Element Method. The experimental setting is reproduced in the numerical simulations using both individual spherical particles and agglomerates of spherical particles shaped as irregular boulders, according to rock models obtained with a 3D scanner. The numerical experiments also reproduces the force loading on one of the wall to vary the pressure inside the box.We are interested in the velocity, attenuation and energy transmission of the waves. These quantities are measured in the experiments and in the simulations. We study the dependance of these three parameters with characteristics like: impact speed, properties of the target material and the pressure in the media.These results are relevant to understand the outcomes of impacts in rubble/gravel pile asteroids.

Detoxification, endocrine, and immune responses of tree swallow nestlings naturally exposed to air contaminants from the Alberta oil sands.

PubMed

Cruz-Martinez, Luis; Fernie, Kim J; Soos, Catherine; Harner, Tom; Getachew, Fitsum; Smits, Judit E G

2015-01-01

Changes in environmental and wildlife health from contaminants in tailings water on the Canadian oil sands have been well-studied; however, effects of air contaminants on wildlife health have not. A field study was conducted to assess biological costs of natural exposure to oil sands-related air emissions on birds. Nest boxes for tree swallows (Tachycineta bicolor) were erected at two sites; within 5 km of active oil sands mining and extraction, and ≥ 60 km south, at one reference site. Passive air monitors were deployed at the nest boxes to measure nitrogen dioxide, sulfur dioxide, ozone, volatile organic compounds, and polycyclic aromatic hydrocarbons (PAHs). Nestlings were examined at day 9 post hatching to assess T cell function and morphometry. At day 14 post hatching, a subset of nestlings was euthanized to measure detoxification enzymes, endocrine changes, and histological alterations of immune organs. Except for ozone, all air contaminants were higher at the two oil sands sites than the reference site (up to 5-fold). Adult birds had similar reproductive performance among sites (p>0.05). Nestlings from industrial sites showed higher hepatic ethoxyresorufin O-dealkylase (EROD) induction (p<0.0001) with lower relative hepatic mass (p=0.0001), a smaller T cell response to the phytohemagglutinin skin test (p=0.007), and smaller bursae of Fabricius (p<0.02); a low sample size for one site indicating lower body condition scores (p=0.01) at day 14 warrants cautious interpretation. There were no differences among nestlings for feather corticosterone (p>0.6), and no histological alterations in the spleen or bursa of Fabricius (p>0.05). This is the first report examining toxicological responses in wild birds exposed to air contaminants from industrial activity in the oil sands. It is also the first time that small, individual air contaminant monitors have been used to determine local contaminant levels in ambient air around nest boxes of wild birds. Copyright © 2014 Elsevier B.V. All rights reserved.

Sandbox experiments on Uraninite Ore: ERT and SP measurments.

NASA Astrophysics Data System (ADS)

Singh, R. K.

2015-12-01

Nuclear energy, considering its own intrinsic merits, would be a leading source for meeting the energy requirement in present and future scenario. Concealed Uranium deposits under sedimentary cover, with poor surface indications calls for reorientation of survey with large inputs involving integrated geophysical approach. Sand Box experiments have been carried out over Uraninite ore. The tank is a glass fish tank (height 39 cm, length 75 cm, width 30 cm). It was filled with sand up to 35 cm high. The sand was saturated from below to minimize the entrapment of the gas bubbles. The average size for sand grains is ~ 0.295mm. The formation factor of the sand is 3.5, with a negligible surface conductivity because of the coarse nature of the sand grains. The dimension of considered Uraninite ore sample is 4cm x 4cm x 4cm. The depth of top of the ore sample is kept at 3cm. In this paper both resistivity and self-potential measurements were carried out for possible detection of Uraninite. The resistivity measurements were made with 64 non-polarizable electrodes using Electrical Resistivity Tomography (ERT) equipment of FlashRes Universal developed by ZZ Resistivity Imaging Pty. Ltd. We have used screws of length 3cm as electrodes. The separation between these electrodes are ~ 1cm. The resistivity tomography results clearly outlines the target Uraninite body. The resistivity tomography results also detects small heterogeneities associated with air bubbles possibly due to unsaturated pore spaces. SP measurements were made using two non-polarizing Pb/PbCl2 electrodes and a Fluke 289 voltmeter (sensitivity 0.001 mV, internal impedance 100 MOhm). The reference electrode was located on the corner of the sandbox. The other electrode was used to scan the electrical potential at the surface of the sand. SP measurements were made with a spacing of 3 cm over the same ERT profile. The SP results also shows a dip (or a low SP anomaly) over the target ore body sample. Thus, both SP and ERT results show the presence of Uraninite and could be used on the routine basis for possible detection of Uraninite.

Efficient high-dimensional characterization of conductivity in a sand box using massive MRI-imaged concentration data

NASA Astrophysics Data System (ADS)

Lee, J. H.; Yoon, H.; Kitanidis, P. K.; Werth, C. J.; Valocchi, A. J.

2015-12-01

Characterizing subsurface properties, particularly hydraulic conductivity, is crucial for reliable and cost-effective groundwater supply management, contaminant remediation, and emerging deep subsurface activities such as geologic carbon storage and unconventional resources recovery. With recent advances in sensor technology, a large volume of hydro-geophysical and chemical data can be obtained to achieve high-resolution images of subsurface properties, which can be used for accurate subsurface flow and reactive transport predictions. However, subsurface characterization with a plethora of information requires high, often prohibitive, computational costs associated with "big data" processing and large-scale numerical simulations. As a result, traditional inversion techniques are not well-suited for problems that require coupled multi-physics simulation models with massive data. In this work, we apply a scalable inversion method called Principal Component Geostatistical Approach (PCGA) for characterizing heterogeneous hydraulic conductivity (K) distribution in a 3-D sand box. The PCGA is a Jacobian-free geostatistical inversion approach that uses the leading principal components of the prior information to reduce computational costs, sometimes dramatically, and can be easily linked with any simulation software. Sequential images of transient tracer concentrations in the sand box were obtained using magnetic resonance imaging (MRI) technique, resulting in 6 million tracer-concentration data [Yoon et. al., 2008]. Since each individual tracer observation has little information on the K distribution, the dimension of the data was reduced using temporal moments and discrete cosine transform (DCT). Consequently, 100,000 unknown K values consistent with the scale of MRI data (at a scale of 0.25^3 cm^3) were estimated by matching temporal moments and DCT coefficients of the original tracer data. Estimated K fields are close to the true K field, and even small-scale variability of the sand box was captured to highlight high K connectivity and contrasts between low and high K zones. Total number of 1,000 MODFLOW and MT3DMS simulations were required to obtain final estimates and corresponding estimation uncertainty, showing the efficiency and effectiveness of our method.

A study on cow comfort and risk for lameness and mastitis in relation to different types of bedding materials.

PubMed

van Gastelen, S; Westerlaan, B; Houwers, D J; van Eerdenburg, F J C M

2011-10-01

The aim was to obtain data regarding the effects of 4 freestall bedding materials (i.e., box compost, sand, horse manure, and foam mattresses) on cow comfort and risks for lameness and mastitis. The comfort of freestalls was measured by analyzing the way cows entered the stalls, the duration and smoothness of the descent movement, and the duration of the lying bout. The cleanliness of the cows was evaluated on 3 different body parts: (1) udder, (2) flank, and (3) lower rear legs, and the bacteriological counts of the bedding materials were determined. The combination of the cleanliness of the cows and the bacteriological count of the bedding material provided an estimate of the risk to which dairy cows are exposed in terms of intramammary infections. The results of the hock assessment revealed that the percentage of cows with healthy hocks was lower (20.5 ± 6.7), the percentage of cows with both damaged and swollen hocks was higher (26.8 ± 3.2), and the severity of the damaged hock was higher (2.32 ± 0.17) on farms using foam mattresses compared with deep litter materials [i.e., box compost (64.0 ± 10.4, 3.5 ± 4.7, 1.85 ± 0.23, respectively), sand (54.6 ± 8.2, 2.0 ± 2.8, 1.91 ± 0.09, respectively), and horse manure (54.6 ± 4.5, 5.5 ± 5.4, 1.85 ± 0.17, respectively)]. In addition, cows needed more time to lie down (140.2 ± 84.2s) on farms using foam mattresses compared with the deep litter materials sand and horse manure (sand: 50.1 ± 31.6s, horse manure: 32.9 ± 0.8s). Furthermore, the duration of the lying bout was shorter (47.9 ± 7.4 min) on farms using foam mattresses compared to sand (92.0 ± 12.9 min). These results indicate that deep litter materials provide a more comfortable lying surface compared with foam mattresses. The 3 deep litter bedding materials differed in relation to each other in terms of comfort and their estimate of risk to which cows were exposed in terms of intramammary infections [box compost: 17.8 cfu (1.0(4)) ± 19.4/g; sand: 1.2 cfu (1.0(4)) ± 1.6/g; horse manure: 110.5 cfu (1.0(4)) ± 86.3/g]. Box compost had a low gram-negative bacterial count compared with horse manure, and was associated with less hock injury compared with foam mattresses, but did not improve lying behavior (lying descent duration: 75.6 ± 38.8s, lying bout duration: 46.1 ± 18.5 min). Overall, sand provided the best results, with a comfortable lying surface and a low bacterial count. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Oil Sands Operations in Alberta, Canada: A large source of secondary organic aerosol

NASA Astrophysics Data System (ADS)

Liggio, J.; Li, S. M.; Hayden, K.; Taha, Y. M.; Stroud, C.; Darlington, A. L.; Drollette, B.; Gordon, M.; Lee, P.; Liu, P.; Leithead, A.; Moussa, S.; Wang, D.; O'Brien, J.; Mittermeier, R. L.; Brook, J.; Lu, G.; Staebler, R. M.; Han, Y.; Tokarek, T. W.; Osthoff, H. D.; Makar, P.; Zhang, J.; Plata, D.; Gentner, D. R.

2015-12-01

Little is known of the reaction products of emissions to the atmosphere from extraction of oil from unconventional sources in the oil sands (OS) region of Alberta, Canada. This study examines these reaction products, and in particular, the extent to which they form secondary organic aerosol (SOA), which can significantly contribute to regional particulate matter formation. An aircraft measurement campaign was conducted over the Athabasca oil sands region between August 13 and September 7, 2013. A broad suite of measurements were made during 22 flights, including organic aerosol mass and composition with a High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and organic aerosol gas-phase precursors by Proton Transfer Reaction (PTR) and off-line gas chromatography mass spectrometry. Large concentrations of organic aerosol were measured downwind of the OS region, which we show to be entirely secondary in nature. Laboratory experiments demonstrated that bitumen (the mined product) contains semi-volatile vapours in the C12-C18 range that will be emitted at ambient temperatures. When oxidized, these vapours form SOA with highly similar HR-ToF-AMS spectra to the SOA measured in the flights. Box modelling of the OS plume evolution indicated that the measured levels of traditional volatile organic compounds (VOCs) are not capable of accounting for the amount of SOA formed in OS plumes. This discrepancy is only reconciled in the model by including bitumen vapours along with their oxidation and condensation into the model. The concentration of bitumen vapours required to produce SOA matching observations is similar to that of traditional VOC precursors of SOA. It was further estimated that the cumulative SOA mass formation approximately 100 km downwind of the OS during these flights, and under these meteorological conditions was up to 82 tonnes/day. The combination of airborne measurements, laboratory experiments and box modelling indicated that semi-volatile organic compounds (SVOC) are emitted from OS operations which accounted for >85% of the formed SOA mass in these plumes. Implications of this SOA formation will be discussed.

"Techniques for Teachers" Section

ERIC Educational Resources Information Center

Manchester, P., Ed.

1976-01-01

Presented are two science demonstration projects: (1) the simulation of a magnetic survey utilizing a bar magnet buried in a sand box and (2) an investigation of the reaction between lead nitrate and sodium hydroxide. (SL)

Laboratory study of polymer solutions used for mobility control during in situ NAPL recovery

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

Martel, K.E.; Martel, R.; Lefebvre, R.

1998-12-31

The use of surfactant solutions for the in situ recovery of residual NAPL in aquifers is increasingly considered as a viable remediation technique. The injection of a few pore volumes of high-concentration surfactant solutions can mobilize or solubilize most of the residual NAPL contacted by the solutions. However, the washing solutions` physico-chemical properties (low density and high viscosity), combined with the natural porous media heterogeneity, can prevent a good sweep of the entire contaminated volume. The objective of this laboratory study is first to select and characterize polymers that would be suitable for aquifer restoration. Their experiments showed that amongmore » several polymers, xanthan gum is the most suitable for aquifer remediation. An evaluation of xanthan gum solution rheology was made in order to predict shear rates, xanthan gum concentrations, salinity, and temperature effects on solution viscosity. The second set of experiments were made with a sand box which was designed to reproduce a simple heterogeneous media consisting of layers of sand with different permeability. These tests illustrate the xanthan gum solution`s ability to increase surfactant solution`s sweep efficiency and limit viscous fingering.« less

The Delta Box: a Table-top Glimpse Into Sequence Stratigraphy

NASA Astrophysics Data System (ADS)

Campbell, K. M.; Hickson, T.; Martin, J.; Paola, C.

2006-12-01

Physical models offer an effective means of providing greater understanding of surface processes and depositional products. At the National Center for Earth-surface Dynamics' research facility, St. Anthony Falls Laboratory; we have seen that in addition to being critically important to the advancement of surface process research, experiments are extremely effective tools for engaging students, especially undergraduates, in understanding these linkages. However, many colleges and universities cannot afford the space or time to support large research or teaching flumes, so we have devised an inexpensive table-top tank that can be used in teaching deltaic depositional processes and concepts of sequence stratigraphy. Our "Delta Box" measures approximately 1.2 by 0.6 meters and is built primarily of parts available at local hardware stores or lumberyards. A simple pond pump drives a water recirculation system, while a constant head tank constructed from PVC pipe regulates the rate of water flow into the flume. A sand/coal sediment mix, fed by hand into the tank, provides a very clear visual distinction between coarse and fine particles on a continental shelf and slope constructed of foam insulation. We have tested the box with a group of undergraduate faculty from around the United States at an "On the Cutting Edge" workshop, at which we were able to consistently build many classic deltaic features, as well as show delta progradation, the effects of waves on sediment transport and deposition, and the formation of sequence boundaries and the entire suite of key sequence stratigraphic features. A manual for building the box, as well as a short movie clip of the workshop participants experimenting with it, is available at http://www.nced.edu/SERC.html. Several of the participants are currently building additional boxes; we plan to post improved instructions and example exercises on the National Center for Earth-surface Dynamics website.

GPR monitoring for non-uniform infiltration through a high permeable gravel layer in the test sand box

NASA Astrophysics Data System (ADS)

Kuroda, Seiichiro; Ishii, Nobuyuki; Morii, Toshihiro

2017-04-01

Recently capillary barriers have been known as a method to protect subsurface regions against infiltration from soil surface. It has essentially non-uniform structure of permeability or soil physical property. To identify the function of the capillary barrier, the site-characterization technique for non-uniform soil moisture distribution and infiltration process is needed. We built a sand box in which a thin high-permeable gravel layer was embedded and conducted a infiltration test, including non-uniform flow of soil water induced by capillary barrier effects. We monitored this process by various types of GPR measurements, including time-lapsed soundings with multi-frequency antenna and transmission measurements like one using cross-borehole radar. Finally we will discuss the applicability of GPR for monitoring the phenomena around the capillary barrier of soil. This work has partially supported by JSPS Grant-in-aid Scientific Research program, No.16H02580.

Testing of the box transformer 10/04.4 kV in the network of the electricity supply company

NASA Astrophysics Data System (ADS)

Cichowski, R.; Nickling, G.

1983-08-01

Applications of a 10/0.4 kV box transformer are studied. Single phase and triple phase prototypes were tested in a distribution network. Test results show that heat loss, hence ground desiccation danger is eliminated by using lean concrete as bedding material (ratio of weight sand: cement: water = 19:1:2). Redistribution of no-load losses and winding losses reduces the total loss from 460 to 324 W, and improves the connection technique.

23. CORE WORKER OPERATING A COREBLOWER THAT PNEUMATICALLY FILLED CORE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. CORE WORKER OPERATING A CORE-BLOWER THAT PNEUMATICALLY FILLED CORE BOXES WITH RESIGN IMPREGNATED SAND AND CREATED A CORE THAT THEN REQUIRED BAKING, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

Modeling Polymer Stabilized Nano-scale Zero Valent Iron Transport Experiments in Porous Media to Understand the Transport Behavior

NASA Astrophysics Data System (ADS)

Mondal, P.; Krol, M.; Sleep, B. E.

2015-12-01

A wide variety of groundwater contaminants can be treated with nano-scale zero valent iron (nZVI). However, delivery of nZVI in the subsurface to the treatment zones is challenging as the bare nZVI particles have a higher tendency to agglomerate. The subsurface mobility of nZVI can be enhanced by stabilizing nZVI with polymer, such as carboxymethyl cellulose (CMC). In this study, numerical simulations were conducted to evaluate CMC stabilized nZVI transport behavior in porous media. The numerical simulations were based on a set of laboratory-scale transport experiments that were conducted in a two-dimensional water-saturated glass-walled sandbox (length - 55 cm; height - 45 cm; width - 1.4 cm), uniformly packed with silica sand. In the transport experiments: CMC stabilized nZVI and a non-reactive dye tracer Lissamine Green B (LGB) were used; water specific discharge and CMC concentration were varied; movements of LGB, and CMC-nZVI in the sandbox were tracked using a camera, a light source and a dark box. The concentrations of LGB, CMC, and CMC-nZVI at the sandbox outlet were analyzed. A 2D multiphase flow and transport model was applied to simulate experimental results. The images from LGB dye transport experiments were used to determine the pore water velocities and media permeabilities in various layers in the sand box. These permeability values were used in the subsequent simulations of CMC-nZVI transport. The 2D compositional simulator, modified to include colloid filtration theory (CFT), treated CMC as a solute and nZVI as a colloid. The simulator included composition dependent viscosity to account for CMC injection and mixing, and attachment efficiency as a fitting parameter for nZVI transport modeling. In the experiments, LGB and CMC recoveries were greater than 95%; however, CMC residence time was significantly higher than the LGB residence time and the higher CMC concentration caused higher pressure drops in the sandbox. The nZVI recovery was lower than 40% in all experiments. The simulation results were found to be in good agreement with the experimental results, implying that the compositional simulator including CFT-modified transport equations could be utilized for the estimation of CMC-stabilized nZVI transport in porous media and design of field scale implementations of CMC-nZVI for remediation.

High-Frequency, Crosswell Radar Data Collected in a Laboratory Tank

USGS Publications Warehouse

Peters, Bas; Moulton, Craig W.; Ellefsen, Karl J.; Horton, Robert J.; McKenna, Jason R.

2010-01-01

Crosswell radar data were collected among three wells in a laboratory tank filled with dry sand. Embedded within the sand was a long plastic box, which was the target for the data collection. Two datasets were collected between each pair of wells, making a total of six datasets. The frequencies in the data ranged from 0.5 to 1.5 gigahertz, and the peak frequency was 0.9 gigahertz. The data are well suited for evaluating various processing algorithms, and the data linearly scale to typical field conditions.

Understanding the primary emissions and secondary formation of gaseous organic acids in the oil sands region of Alberta, Canada

NASA Astrophysics Data System (ADS)

Liggio, John; Moussa, Samar G.; Wentzell, Jeremy; Darlington, Andrea; Liu, Peter; Leithead, Amy; Hayden, Katherine; O'Brien, Jason; Mittermeier, Richard L.; Staebler, Ralf; Wolde, Mengistu; Li, Shao-Meng

2017-07-01

Organic acids are known to be emitted from combustion processes and are key photochemical products of biogenic and anthropogenic precursors. Despite their multiple environmental impacts, such as on acid deposition and human-ecosystem health, little is known regarding their emission magnitudes or detailed chemical formation mechanisms. In the current work, airborne measurements of 18 gas-phase low-molecular-weight organic acids were made in the summer of 2013 over the oil sands region of Alberta, Canada, an area of intense unconventional oil extraction. The data from these measurements were used in conjunction with emission retrieval algorithms to derive the total and speciated primary organic acid emission rates, as well as secondary formation rates downwind of oil sands operations. The results of the analysis indicate that approximately 12 t day-1 of low-molecular-weight organic acids, dominated by C1-C5 acids, were emitted directly from off-road diesel vehicles within open pit mines. Although there are no specific reporting requirements for primary organic acids, the measured emissions were similar in magnitude to primary oxygenated hydrocarbon emissions, for which there are reporting thresholds, measured previously ( ≈ 20 t day-1). Conversely, photochemical production of gaseous organic acids significantly exceeded the primary sources, with formation rates of up to ≈ 184 t day-1 downwind of the oil sands facilities. The formation and evolution of organic acids from a Lagrangian flight were modelled with a box model, incorporating a detailed hydrocarbon reaction mechanism extracted from the Master Chemical Mechanism (v3.3). Despite evidence of significant secondary organic acid formation, the explicit chemical box model largely underestimated their formation in the oil sands plumes, accounting for 39, 46, 26, and 23 % of the measured formic, acetic, acrylic, and propionic acids respectively and with little contributions from biogenic VOC precursors. The model results, together with an examination of the carbon mass balance between the organic acids formed and the primary VOCs emitted from oil sands operations, suggest the existence of significant missing secondary sources and precursor emissions related to oil sands and/or an incomplete mechanistic and quantitative understanding of how they are processed in the atmosphere.

Photographic copy of 3 ½” x 5” glass lantern slide ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photographic copy of 3 ½” x 5” glass lantern slide no. 20 of drawing. Located in wooden pine box #23 in box 84 of 94 at the National Museum of American History, Smithsonian Institution, Archives Center, Work and industry Division, Washington, D.C. Original photographer, Milton R. Homes, Philadelphia, Pennsylvania. Illustrator Unknown. DRAWING ENTITLED “THE SAND ISLAND METHOD”. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

Analogue modelling for localization of deformation in the extensional pull-apart basins: comparison with the west part of NAF, Turkey

NASA Astrophysics Data System (ADS)

Bulkan, Sibel; Storti, Fabrizio; Cavozzi, Cristian; Vannucchi, Paola

2017-04-01

Analogue modelling remains one of the best methods for investigating progressive deformation of pull apart systems in strike slip faults that are poorly known. Analogue model experiments for the North Anatolian Fault (NAF) system around the Sea of Marmara are extremely rare in the geological literature. Our purpose in this work is to monitor the relation between the horizontal propagation and branching of the strike slip fault, and the structural and topographic expression resulting from this process. These experiments may provide insights into the geometric evolution and kinematic of west part of the NAF system. For this purpose, we run several 3D sand box experiments, appropriately scaled. Plexiglass sheets were purposely cut to simulate the geometry of the NAF. Silicone was placed on the top of these to simulate the viscous lower crust, while the brittle upper crust was simulated with pure dry sand. Dextral relative fault motion was imposed as well using different velocities to reproduce different strain rates and pull apart formation at the releasing bend. Our experiments demonstrate the variation of the shear zone shapes and how the master-fault propagates during the deformation, helping to cover the gaps between geodetic and geologic slip information. Lower crustal flow may explain how the deformation is transferred to the upper crust, and stress partitioned among the strike slip faults and pull-apart basin systems. Stress field evolution seems to play an interesting role to help strain localization. We compare the results of these experiments with natural examples around the western part of NAF and with seismic observations.

Generation of buckle folds in Naga fold thrust belt, north-east India

NASA Astrophysics Data System (ADS)

Saha, B.; Dietl, C.

2009-04-01

Naga fold thrust belt (NFTB), India, formed as a result of northward migration of the Indian plate initiated in Eocene and its subsequent collision with the Burmese plate during Oligocene. The NW-SE oriented compression generated a spectrum of structures; among them, we intend to focus on the folds- varying from gentle to tight asymmetric in geometry. Large recumbent folds are often associated with thrusting. Buckle folds forming under shallow crustal conditions are frequently reported from NFTB. Buckle folding occurs mainly within sandstones with intercalated shale layers which are in the study area typical for the Barail, Surma and Tipam Groups. We have tried to explain the controlling factors behind the variation of the buckle fold shapes and their varying wavelengths throughout the fold thrust belt with the aid of analogue (sand box) modelling. It is undoubted that competence contrast along with the layer parallel compressive stress are the major influencing factors in generation of buckle folds. Schmalholz and Podladchikov (1999) and Jeng et al. (2002) have shown that when low strain rate and low temperature are applicable, not only the viscosity contrast, but also the elasticity contrast govern the geometry of the developing buckle folds. Rocks deforming under high temperature and high pressure deform in pure viscous manner, whereas, rocks undergoing less confining stress and less temperature, are subjected to pure elastic deformation. However, they are the end members, and most of the deformations are a combination of these two end members, i.e. of viscoelastic nature. Our models are made up of sieved sand (0.5 mm grain size) and mica layers (1-5 mm) This interlayering imparts a mechanical anisotropy in the model. Mica is not a pure viscous material, rather it displays more elastic behaviour. The mica layers in the model produce bedding parallel slip during shortening through internal reorganization of the individual mica crystals leading to the thickening of the layer. The experiments are performed in a low stress and low temperature environment (ambient temperature being room temperature). The models produce a spectrum of fold shapes ranging from tight asymmetric to gentle. The folds generate initially as gentle folds with rounded hinges in the thick incompetent mica layers and box folds in the thin incompetent mica layers. Thrusts develop and grow by intersecting the existing fold limbs. With incremental compression, the folds become tighter. The thin mica layer is more affected by thrusting than the thicker layer. Our models have a clear advantage of using mixed layer models (sand + mica) over that of pure sand models, because mica accommodates the applied stress both by folding and thrusting. The pure sand models fail to reflect the subtle competence contrast and thus the buckle folds though they excellently simulate the upper crustal layer deformation through thrusting. From our experiments we infer that the difference in fold and thrust morphology is governed by the interplay of two main factors; namely: degree of competence contrast and thickness of competent unit. High mechanical anisotropy give rise to box folds with steep straight limbs, horizontal hinge and conjugate axial planes when the competent unit is a thick one; whereas comparatively low mechanical anisotropy generates rounded buckle fold when the competent unit is a thin one. The geometry of the buckle folds in the NFTB are in good agreement with our experimentally produced buckle folds. The competence contrast throughout the belt has been consistent, only minor variations of sand-shale content have been observed. The competence contrast remaining more or less constant throughout the region, the variable thickness of the stratigraphic units plays a significant role in determining the fold shape. The thicker incompetent units give rise to rounded tight folds and the thinner ones to open box shaped folds, both modified by simultaneously or later generated thrusts. This coexistence of folds as well as thrusts developing simultaneously has been well demonstrated with our models. Therefore, our modelling results give insight into the folding process and the occurrence of differing buckle fold geometry across the NFTB. Reference: Jeng F. S., Lin M.L., Lai Y.C., Teng M.H., 2002. Influence of strain rate on buckle folding of an elasto-viscous single layer. Journal of Structural Geology 24, 501-516. Schmalholz S.M., Podladchikov, Y.Y., 1999. Buckling versus folding: importance of viscoelasticity. Geophysical Research Letters 26, 2641-2644.

Optimized conditions for phytoremediation of diesel by Scirpus grossus in horizontal subsurface flow constructed wetlands (HSFCWs) using response surface methodology.

PubMed

Al-Baldawi, Israa Abdul Wahab; Sheikh Abdullah, Siti Rozaimah; Abu Hasan, Hassimi; Suja, Fatihah; Anuar, Nurina; Mushrifah, Idris

2014-07-01

This study investigated the optimum conditions for total petroleum hydrocarbon (TPH) removal from diesel-contaminated water using phytoremediation treatment with Scirpus grossus. In addition, TPH removal from sand was adopted as a second response. The optimum conditions for maximum TPH removal were determined through a Box-Behnken Design. Three operational variables, i.e. diesel concentration (0.1, 0.175, 0.25% Vdiesel/Vwater), aeration rate (0, 1 and 2 L/min) and retention time (14, 43 and 72 days), were investigated by setting TPH removal and diesel concentration as the maximum, retention time within the given range, and aeration rate as the minimum. The optimum conditions were found to be a diesel concentration of 0.25% (Vdiesel/Vwater), a retention time of 63 days and no aeration with an estimated maximum TPH removal from water and sand of 76.3 and 56.5%, respectively. From a validation test of the optimum conditions, it was found that the maximum TPH removal from contaminated water and sand was 72.5 and 59%, respectively, which was a 5 and 4.4% deviation from the values given by the Box-Behnken Design, providing evidence that S. grossus is a Malaysian native plant that can be used to remediate wastewater containing hydrocarbons. Copyright © 2014 Elsevier Ltd. All rights reserved.

Home Mechanics for the Visually Impaired.

ERIC Educational Resources Information Center

Utrup, Robert G.

The manual is intended to be used in a course on home mechanics for the visually handicapped and is organized into 17 lessons. Lessons cover the following topics: adhesives (such as Elmer's glue), cleaning drains, faucet repairs, fire extinguishers, the flush tank, the fuse box, glazing, hammers, hand sanding, handsaws, hangers, nails and wood…

Landscape in a Lacquer Box

ERIC Educational Resources Information Center

Savage, Martha

2010-01-01

A symbolic dry landscape garden of Eastern origin holds a special fascination for the author's middle-school students, which is why the author chose to create a project exploring this view of nature. A dry landscape garden, or "karesansui," is an arrangement of rocks, worn by nature and surrounded by a "sea" of sand, raked into patterns…

Effect of Fractal Dimension on the Strain Behavior of Particulate Media

NASA Astrophysics Data System (ADS)

Altun, Selim; Sezer, Alper; Goktepe, A. Burak

2016-12-01

In this study, the influence of several fractal identifiers of granular materials on dynamic behavior of a flexible pavement structure as a particulate stratum is considered. Using experimental results and numerical methods as well, 15 different grain-shaped sands obtained from 5 different sources were analyzed as pavement base course materials. Image analyses were carried out by use of a stereomicroscope on 15 different samples to obtain quantitative particle shape information. Furthermore, triaxial compression tests were conducted to determine stress-strain and shear strength parameters of sands. Additionally, the dynamic response of the particulate media to standard traffic loads was computed using finite element modeling (FEM) technique. Using area-perimeter, line divider and box counting methods, over a hundred grains for each sand type were subjected to fractal analysis. Relationships among fractal dimension descriptors and dynamic strain levels were established for assessment of importance of shape descriptors of sands at various scales on the dynamic behavior. In this context, the advantage of fractal geometry concept to describe irregular and fractured shapes was used to characterize the sands used as base course materials. Results indicated that fractal identifiers can be preferred to analyze the effect of shape properties of sands on dynamic behavior of pavement base layers.

Steam and air co-injection in removing residual TCE in unsaturated layered sandy porous media.

PubMed

Peng, Sheng; Wang, Ning; Chen, Jiajun

2013-10-01

Steam and air co-injection is a promising technique for volatile and semi-volatile organic contaminant remediation in heterogeneous porous media. In this study, removal of trichloroethene (TCE) with steam-air co-injection was investigated through a series of 2D sandbox experiments with different layered sand structures, and through numerical simulations. The results show that a layered structure with coarse sand, in which steam and air convection are relatively rapid, resulted in a higher removal rate and a larger removal ratio than those observed in an experiment using finer sand; however, the difference was not significant, and the removal ratios from three experiments ranged from 85% to 94%. Slight downward movement of TCE was observed for Experiment 1 (TCE initially in a fine sand zone encased in a coarse sand), while no such movement was observed for Experiment 2 (TCE initially in two fine sand layers encased in a coarse sand) or 3 (TCE initially in a silty sand zone encased in a coarse sand). Simulations show accumulation of TCE at the interface of the layered sands, which indicates a capillary barrier effect in restraining the downward movement of TCE. This effect is illustrated further by a numerical experiment with homogeneous coarse sand, in which continuous downward TCE movement to the bottom of the sandbox was simulated. Another numerical experiment with higher water saturation was also conducted. The results illustrate a complicated influence of water saturation on TCE removal in a layered sand structure. Published by Elsevier B.V.

77 FR 29961 - Fisheries of the Exclusive Economic Zone off Alaska and Pacific Halibut Fisheries; Observer Program

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-21

... Science Center, 7600 Sand Point Way NE., Building 4, Observer Training Room (1055), Seattle, WA 98115..., Sustainable Fisheries Division, Alaska Region NMFS, Attn: Ellen Sebastian. Mail comments to P.O. Box 21668..., Sustainable Fisheries Division, Alaska Region NMFS, Attn: Ellen Sebastian. Fax comments to 907-586-7557. Hand...

Primary school children and teachers discover the nature and science of planet Earth and Mars

NASA Astrophysics Data System (ADS)

Kleinhans, Maarten; Verkade, Alex; Bastings, Mirjam; Reichwein, Maarten

2016-04-01

For various reasons primary schools emphasise language and calculus rather than natural sciences. When science is taught at all, examination systems often favour technological tricks and knowledge of the 'right' answer over the process of investigation and logical reasoning towards that answer. Over the long term, this is not conducive to curiosity and scientific attitude in large parts of the population. Since the problem is more serious in primary than in secondary education, and as children start their school career with a natural curiosity and great energy to explore their world, we focus our efforts on primary school teachers in close collaboration with teachers and researchers. Our objective was to spark children's curiosity and their motivation to learn and discover, as well as to help teachers develop self-afficacy in science education. To this end we developed a three-step program with a classroom game and sand-box experiments related to planet Earth and Mars. The classroom game Expedition Mundus simulates science in its focus on asking questions, reasoning towards answers on the basis of multiple sources and collaboration as well as growth of knowledge. Planet Mundus is entirely fictitional to avoid differences in foreknowledge between pupils. The game was tested in hundreds of classes in primary schools and the first years of secondary education and was printed (in Dutch) and distributed over thousands of schools as part of teacher education through university science hubs. Expedition Mundus was developed by the Young Academy of the Royal Netherlands Academy of Arts and Sciences and De Praktijk. The tested translations in English and German are available on http://www.expeditionmundus.org. Following the classroom game, we conducted simple landscape experiments in sand boxes supported by google earth imagery of real rivers, fans and deltas on Earth and Mars. This was loosely based on our fluvial morphodynamics research. This, in the presence of a scientist, evoked questions that were developed by Aristotelian discourse towards researchable empirical questions. Here teachers and scientists closely collaborated to develop effective queries. The final questions were then investigated by couples of pupils following the empirical cycle up to the point of a poster presentation.

Let us keep observing and play in sand boxes (Henry Darcy Medal Lecture)

NASA Astrophysics Data System (ADS)

Illangasekare, T. H.

2012-04-01

Henry Darcy was a civil engineer recognized for a number of technical achievements and scientific discoveries. The sand column experiments for which he is known revealed the linear relationship that exists between fluid motion and driving forces at low velocities. Freeze and Back (1983) stated, ''The experiments carried out by Darcy with the help of his assistant, Ritter, in Dijon, France in 1855 and 1856 represent the beginning of groundwater hydrology as a quantitative science." Because of the prominence given to this experiment, two important facts behind Darcy's contributions to subsurface hydrology have not received much attention. First, Darcy was not only a good engineer, but he was also a highly respected scientist whose knowledge of both the fundamentals of fluid mechanics and the natural world of geology led to better conceptualizing and quantifying of groundwater processes at relevant scales to solve practical problems. The experiments for which he is known may have already been conceived, based on his theoretical understanding, and the results were anticipated (Brown 2002). Second, Darcy, through his contributions with Dupuit, showed that they understood hydrologeology at a regional scale and developed methods for quantification at the scale of geologic stratum (Ritz and Bobek, 2008). The primary thesis of this talk is that scientific contributions such as the one Darcy made require appreciation and a thorough understanding of fundamental theory coupled with observation and recording of phenomena both in nature and in the laboratory. Along with all of the significant theoretical, mathematical modeling, and computational advances we have made in the last several decades, laboratory experiments designed to observe phenomena and processes for better insight, accurate data generation, and hypothesis development are critically important to make scientific and engineering advances to address some of the emerging and societally important problems in hydrology and water resources engineering. Kleinhans et al. (2010) convincingly argued the same point, noting, "Many major issues of hydrology are open to experimental investigation." Current and emerging problems with water supply and their hydrologic implications are associated with sustainability of water as a resource for global food production, clean water for potable use, protection of human health, and impacts and implications of global warming and climate change on water resources. This talk will address the subsurface hydrologic science issues that are central to these problems and the role laboratory experimentation can play in helping to advance the basic knowledge. Improved understanding of fundamental flow, transport, reactive, and biological processes that occur at the pore-scale and their manifestation at different modeling and observational scales will continue to advance the subsurface science. Challenges also come from the need to integrate porous media systems with bio-geochemical and atmospheric systems, requiring observing and quantifying complex phenomena across interfaces (e.g., fluid/fluid in pores to land/atmospheric in the field). This talk will discuss how carefully designed and theory driven experiments at various test scales can play a central role in providing answers to critical scientific questions and how they will help to fill knowledge gaps. It will also be shown that careful observations will lead to the refinement of existing theories or the development of new ones. Focusing on the subsurface, the need to keep observing through controlled laboratory experimentation in various test scales from small cells to large sand boxes will be emphasized. How the insights obtained from such experiments will complement modeling and field investigations are highlighted through examples.

Thermomechanical properties and fracture of resin-bonded-sand cores - Experimental study and application in aluminium foundry

NASA Astrophysics Data System (ADS)

Menet, Claire; Reynaud, Pascal; Fantozzi, Gilbert; Thibault, Delphine; Laforêt, Adrien

2017-06-01

Sand cores are used to produce internal cavities of metallic cast parts with complex shapes like automotive cylinder heads. Foundry cores are granular materials made of sand grains aggregated with binder bridges. In the cold box coring process, the binder is a polyurethane resin. It is noteworthy that during the casting of the liquid metal, the polymer binder is seriously damaged. This kind of materials has been poorly investigated so far. This study aims for a better understanding of the mechanical behaviour and fracture of cores subjected to various loads and thermal ageing. Particularly, the focus is on the decoring step, which consists in removing the sand by hammering and vibration of the metallic part after casting. This major project, generated from the collaboration of the aluminum casting company Montupet, and two laboratories Centre des Matériaux (CdM) and MATEIS, includes both experimental and numerical activities in order to model the decoring step of cylinder heads based on empiric data. Here, the experimental part of the work is presented.

34. DESPATCH CORE OVENS, GREY IRON FOUNDRY CORE ROOM, BAKES ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

34. DESPATCH CORE OVENS, GREY IRON FOUNDRY CORE ROOM, BAKES CORES THAT ARE NOT MADE ON HEATED OR COLD BOX CORE MACHINES, TO SET BINDING AGENTS MIXED WITH THE SAND CREATING CORES HARD ENOUGH TO WITHSTAND THE FLOW OF MOLTEN IRON INSIDE A MOLD. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

Factors influencing dust exposure: finishing activities in drywall construction.

PubMed

Simmons, Catherine E; Jones, Rachael M; Boelter, Fred W

2011-05-01

Sanding drywall joint compound is a dusty construction activity. We studied potential factors influencing exposure to respirable and total dust for sanders and bystanders in the area of drywall joint compound finishing in 17 test events within a room-scale isolation chamber. We found the air change rate to be negatively correlated with dust C(twa) both in the sander's personal breathing zone and surrounding area. We could not conclude that sanding tool type systematically influences dust C(twa), but the use of 80-grit abrasive was associated with the highest dust C(twa). We found respirable dusts were uniformly dispersed 1-8.2 m from sanding activities at a fixed location. As anticipated, both respirable and total dust C(twa) in the sander's personal breathing zone are higher than in the surrounding area. The respirable fraction of the total dust mass C(twa) was greater in the surrounding area than in the sander's personal breathing zone. Respirable dust concentrations measured in real time increased over the duration of sanding, exhibiting a temporal trend that is similar to that predicted by the well-mixed box model with contaminant removal by mechanical ventilation only, and continuous emission. Dust concentrations returned to pre-activity (background) levels 2-4 hr after cessation of the sanding activity.

Laboratory Study of Quaternary Sediment Resistivity Related to Groundwater Contamination at Mae-Hia Landfill, Mueang District, Chiang Mai Province

NASA Astrophysics Data System (ADS)

Sichan, N.

2007-12-01

This study was aimed to understand the nature of the resistivity value of the sediment when it is contaminated, in order to use the information solving the obscure interpretation in the field. The pilot laboratory experiments were designed to simulate various degree of contamination and degree of saturation then observe the resulting changes in resistivity. The study was expected to get a better understanding of how various physical parameters effect the resistivity values in term of mathematic function. And also expected to apply those obtained function to a practical quantitatively interpretation. The sediment underlying the Mae-Hia Landfill consists of clay-rich material, with interfingerings of colluvium and sandy alluvium. A systematic study identified four kinds of sediment, sand, clayey sand, sandy clay, and clay. Representative sediment and leachate samples were taken from the field and returned to the laboratory. Both the physical and chemical properties of the sediments and leachate were analyzed to delineate the necessary parameters that could be used in Archie's equation. Sediment samples were mixed with various concentration of leachate solutions. Then the resistivity values were measured at various controlled steps in the saturation degree in a well- calibrated six-electrode model resistivity box. The measured resistivity values for sand, clayey sand, sandy clay when fully and partly saturated were collected, then plotted and fitted to Archie's equation, to obtain a mathematical relationship between bulk resistivity, porosity, saturation degree and resistivity of pore fluid. The results fit well to Archie's equation, and it was possible to determine all the unknown parameters representative of the sediment samples. For sand, clayey sand, sandy clay, and clay, the formation resistivity factors (F) are 2.90, 5.77, 7.85, and 7.85 with the products of cementation factor (m) and the pore geometry factors (a) (in term of -am) are 1.49, -1.63, -1.92, -2.24 and the saturation exponents (n) are 2.06, 2.58, 3.52, and 2.46, respectively. These results were used to reinterpret the existing resistivity data of this area. The result of this reinterpretation is a map showing the quantitative distribution of the contaminant plume in the vicinity of the Mae-Hia Landfill.

Small, Lightweight, Collapsible Glove Box

NASA Technical Reports Server (NTRS)

James, Jerry

2009-01-01

A small, lightweight, collapsible glove box enables its user to perform small experiments and other tasks. Originally intended for use aboard a space shuttle or the International Space Station (ISS), this glove box could also be attractive for use on Earth in settings in which work space or storage space is severely limited and, possibly, in which it is desirable to minimize weight. The development of this glove box was prompted by the findings that in the original space-shuttle or ISS setting, (1) it was necessary to perform small experiments in a large general-purpose work station, so that, in effect, they occupied excessive space; and it took excessive amounts of time to set up small experiments. The design of the glove box reflects the need to minimize the space occupied by experiments and the time needed to set up experiments, plus the requirement to limit the launch weight of the box and the space needed to store the box during transport into orbit. To prepare the glove box for use, the astronaut or other user has merely to insert hands through the two fabric glove ports in the side walls of the box and move two hinges to a locking vertical position (see figure). The user could do this while seated with the glove box on the user fs lap. When stowed, the glove box is flat and has approximately the thickness of two pieces of 8-in. (.20 cm) polycarbonate.

KSC-99pp0553

NASA Image and Video Library

1999-05-18

KENNEDY SPACE CENTER, FLA. -- In the Vehicle Assembly Building (VAB), United Space Alliance technician Robert Williams sands the repaired areas near the top of Space Shuttle Discovery's external tank. Repairs were required for damage caused by hail during recent storms. Because access to all of the damaged areas was not possible at the pad, the Shuttle was rolled back from Pad 39B to the VAB. The work is expected to take two to three days, allowing Discovery to roll back to the pad late this week for launch of mission STS-96, the 94th launch in the Space Shuttle Program. Liftoff will occur no earlier than May 27. STS-96 is a logistics and resupply mission for the International Space Station, carrying such payloads as a Russian crane, the Strela; a U.S.-built crane; the Spacehab Oceaneering Space System Box (SHOSS), a logistics items carrier; and STARSHINE, a student-shared experiment

CSRI Summer Proceedings 2010

DTIC Science & Technology

2010-12-17

AND ADDRESSES U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS Mathematics; Computer Science Eric C...Institute at Sandia National Laboratories Editors: Eric C. Cyr and S. Scott Collis Sandia National Laboratories December 17, 2010 SAND2010-8783P...CSRI and its activities which have benefited both Sandia and the greater research community. Eric C. Cyr S. Scott Collis December 17, 2010 iv CSRI

Two-dimensional explosion experiments examining the interaction between a blast wave and a sand hill

NASA Astrophysics Data System (ADS)

Sugiyama, Y.; Izumo, M.; Ando, H.; Matsuo, A.

2018-05-01

Two-dimensional explosion experiments were conducted to discuss the interaction between a blast wave and sand and show the mitigation effect of the sand on the blast wave. The explosive used was a detonating cord 1.0 m in length, which was initiated in a sand hill shaped like a triangular prism and whose cross section was an isosceles triangle with base angles of 30°. Sand-hill heights of 30 and 60 mm were used as parameters to discuss the effect of sand mass upon blast-wave strength. The interaction of the blast wave with the sand/air interface causes multiple peaks in the blast wave, which are induced by successive transmissions at the interface. The increase in the sand mass further mitigates the blast parameters of peak overpressure and positive impulse. The results of this experiment can be utilized to validate the numerical method of solving the problem of interaction between a compressible fluid and a particle layer.

Two-dimensional explosion experiments examining the interaction between a blast wave and a sand hill

NASA Astrophysics Data System (ADS)

Sugiyama, Y.; Izumo, M.; Ando, H.; Matsuo, A.

2018-02-01

Two-dimensional explosion experiments were conducted to discuss the interaction between a blast wave and sand and show the mitigation effect of the sand on the blast wave. The explosive used was a detonating cord 1.0 m in length, which was initiated in a sand hill shaped like a triangular prism and whose cross section was an isosceles triangle with base angles of 30°. Sand-hill heights of 30 and 60 mm were used as parameters to discuss the effect of sand mass upon blast-wave strength. The interaction of the blast wave with the sand/air interface causes multiple peaks in the blast wave, which are induced by successive transmissions at the interface. The increase in the sand mass further mitigates the blast parameters of peak overpressure and positive impulse. The results of this experiment can be utilized to validate the numerical method of solving the problem of interaction between a compressible fluid and a particle layer.

Two dimensional fall of granular columns controlled by slow horizontal withdrawal of a retaining wall

NASA Astrophysics Data System (ADS)

Mériaux, Catherine

2006-09-01

This paper describes a series of experiments designed to investigate the fall of granular columns in a quasi-static regime. Columns made of alternatively green and red sand layers were initially laid out in a box and then released when a retaining wall was set in slow motion with constant speed. The dependence of the dynamics of the fall on the initial aspect ratio of the columns, the velocity of the wall, and the material properties was investigated within the quasi-static regime. A change in the behavior of the columns was identified to be a function of the aspect ratio (height/length) of the initial sand column. Columns of high aspect ratio first subsided before sliding along failure planes, while columns of small aspect ratio were only observed to slide along failure planes. The transition between these two characteristic falls occurred regardless of the material and the velocity of the wall in the context of the quasi-static regime. When the final height and length of the piles were analyzed, we found power-law relations of the ratio of initial to final height and final run-out to initial length with the aspect ratio of the column. The dissipation of energy is also shown to increase with the run-out length of the pile until it reaches a plateau. Finally, we find that the structure of the slip planes that develop in our experiments are not well described by the failure of Coulomb's wedges for twin retaining rough walls.

Shake table test of soil-pile groups-bridge structure interaction in liquefiable ground

NASA Astrophysics Data System (ADS)

Tang, Liang; Ling, Xianzhang; Xu, Pengju; Gao, Xia; Wang, Dongsheng

2010-03-01

This paper describes a shake table test study on the seismic response of low-cap pile groups and a bridge structure in liquefiable ground. The soil profile, contained in a large-scale laminar shear box, consisted of a horizontally saturated sand layer overlaid with a silty clay layer, with the simulated low-cap pile groups embedded. The container was excited in three El Centro earthquake events of different levels. Test results indicate that excessive pore pressure (EPP) during slight shaking only slightly accumulated, and the accumulation mainly occurred during strong shaking. The EPP was gradually enhanced as the amplitude and duration of the input acceleration increased. The acceleration response of the sand was remarkably influenced by soil liquefaction. As soil liquefaction occurred, the peak sand displacement gradually lagged behind the input acceleration; meanwhile, the sand displacement exhibited an increasing effect on the bending moment of the pile, and acceleration responses of the pile and the sand layer gradually changed from decreasing to increasing in the vertical direction from the bottom to the top. A jump variation of the bending moment on the pile was observed near the soil interface in all three input earthquake events. It is thought that the shake table tests could provide the groundwork for further seismic performance studies of low-cap pile groups used in bridges located on liquefiable groun.

Optimization of permeability for quality improvement by using factorial design

NASA Astrophysics Data System (ADS)

Said, Rahaini Mohd; Miswan, Nor Hamizah; Juan, Ng Shu; Hussin, Nor Hafizah; Ahmad, Aminah; Kamal, Mohamad Ridzuan Mohamad

2017-05-01

Sand castings are used worldwide by the manufacturing process in Metal Casting Industry, whereby the green sand are the commonly used sand mould type in the industry of sand casting. The defects on the surface of casting product is one of the problems in the industry of sand casting. The problems that relates to the defect composition of green sand are such as blowholes, pinholes shrinkage and porosity. Our objective is to optimize the best composition of green sand in order to minimize the occurrence of defects. Sand specimen of difference parameters (Bentonite, Green Sand, Cold dust and water) were design and prepared to undergo permeability test. The 24 factorial design experiment with four factors at difference composition were runs, and the total of 16 runs experiment were conducted. The developed models based on the experimental design necessary models were obtained. The model with a high coefficient of determination (R2=0.9841) and model for predicted and actual fitted well with the experimental data. Using the Analysis of Design Expert software, we identified that bentonite and water are the main interaction effect in the experiments. The optimal settings for green sand composition are 100g silica sand, 21g bentonite, 6.5 g water and 6g coal dust. This composition gives an effect of permeability number 598.3GP.

Deformation of Fold-and-Thrust Belts above a Viscous Detachment: New Insights from Analogue Modelling Experiments

NASA Astrophysics Data System (ADS)

Nogueira, Carlos R.; Marques, Fernando O.

2015-04-01

Theoretical and experimental studies on fold-and-thrusts belts (FTB) have shown that, under Coulomb conditions, deformation of brittle thrust wedges above a dry frictional basal contact is characterized by dominant frontward vergent thrusts (forethrusts) with thrust spacing and taper angle being directly influenced by the basal strength (increase in basal strength leading to narrower thrust spacing and higher taper angles); whereas thrust wedges deformed above a weak viscous detachment, such as salt, show a more symmetric thrust style (no prevailing vergence of thrusting) with wider thrust spacing and shallower wedges. However, different deformation patterns can be found on this last group of thrust wedges both in nature and experimentally. Therefore we focused on the strength (friction) of the wedge basal contact, the basal detachment. We used a parallelepiped box with four fixed walls and one mobile that worked as a vertical piston drove by a computer controlled stepping motor. Fine dry sand was used as the analogue of brittle rocks and silicone putty (PDMS) with Newtonian behaviour as analogue of the weak viscous detachment. To investigate the strength of basal contact on thrust wedge deformation, two configurations were used: 1) a horizontal sand pack with a dry frictional basal contact; and 2) a horizontal sand pack above a horizontal PDMS layer, acting as a basal weak viscous contact. Results of the experiments show that: the model with a dry frictional basal detachment support the predictions for the Coulomb wedges, showing a narrow wedge with dominant frontward vergence of thrusting, close spacing between FTs and high taper angle. The model with a weak viscous frictional basal detachment show that: 1) forethrusts (FT) are dominant showing clearly an imbricate asymmetric geometry, with wider spaced thrusts than the dry frictional basal model; 2) after FT initiation, the movement on the thrust can last up to 15% model shortening, leading to great amount of displacement along the FT; 3) intermittent reactivation of FTs also occurs despite the steepening of the FT plane and existence of new FT ahead, creating a high critical taper angle; 4) injection of PDMS from the basal weak layer into the FTs planes also favours to the long living of FTs and to the high critical taper angle; 5) vertical sand thickening in the hanging block also added to the taper angle.

Effects of sand and straw bedding on the lying behavior, cleanliness, and hoof and hock injuries of dairy cows.

PubMed

Norring, M; Manninen, E; de Passillé, A M; Rushen, J; Munksgaard, L; Saloniemi, H

2008-02-01

This experiment compared the effects of sand and straw bedding in free stalls on resting time, cleanliness, hock injuries, and hoof health of dairy cows and tested whether cow preferences for a bedding material depended on the familiarity with the material. A total of 52 dairy cows were kept either on straw bedded concrete stalls or sand stalls for at least 21 wk. The lying behavior was observed, and hock lesions, hoof health, and cleanliness of the cows and stalls were measured. A 5-d preference test between sand and straw stalls was conducted at the end of the experiment. The total daily duration of lying was longer for cows on straw bedding than on sand bedding (straw 749 +/- 16 vs. sand 678 +/- 19 min). During the preference test, cows that had been kept on straw bedding preferred lying in straw stalls [straw 218.7 (133.4 to 239.7) vs. sand 9.0 min (2.8 to 44.8)]; however, cows that had been kept on sand showed no preference [straw 101.3 (51.7 to 205.9) vs. sand 94.3 min (54.1 to 156.1, median and interquartile range)]. Although there were no differences in the dirtiness of stalls, the cows using straw stalls were dirtier than cows using sand stalls [straw 6.04 (5.39 to 6.28) vs. sand 4.19 (3.62 to 5.16)]. At the end of experiment the severity of hock lesions was lower for cows on sand than for cows on straw [sand 0.5 (0.0 to 1.0) vs. straw 1.0 (1.0 to 2.0)]. The improvement in overall hoof health over the observation period was greater for cows kept on sand compared with cows kept on straw [sand -2.00 (-3.75 to -0.25) vs. straw 0.00 (-2.00 to 2.00)]. Straw bedding increased the time that cows spend lying, and cows preferred straw stalls to sand stalls. However, previous experience with sand reduces avoidance of sand stalls. Sand stalls were advantageous for cow cleanliness and health; hock lesions and claw diseases healed more quickly for cows using sand stalls compared with straw.

Owl Monkeys (Aotus nigriceps and A. infulatus) Follow Routes Instead of Food-Related Cues during Foraging in Captivity

PubMed Central

da Costa, Renata Souza; Bicca-Marques, Júlio César

2014-01-01

Foraging at night imposes different challenges from those faced during daylight, including the reliability of sensory cues. Owl monkeys (Aotus spp.) are ideal models among anthropoids to study the information used during foraging at low light levels because they are unique by having a nocturnal lifestyle. Six Aotus nigriceps and four A. infulatus individuals distributed into five enclosures were studied for testing their ability to rely on olfactory, visual, auditory, or spatial and quantitative information for locating food rewards and for evaluating the use of routes to navigate among five visually similar artificial feeding boxes mounted in each enclosure. During most experiments only a single box was baited with a food reward in each session. The baited box changed randomly throughout the experiment. In the spatial and quantitative information experiment there were two baited boxes varying in the amount of food provided. These baited boxes remained the same throughout the experiment. A total of 45 sessions (three sessions per night during 15 consecutive nights) per enclosure was conducted in each experiment. Only one female showed a performance suggestive of learning of the usefulness of sight to locate the food reward in the visual information experiment. Subjects showed a chance performance in the remaining experiments. All owl monkeys showed a preference for one box or a subset of boxes to inspect upon the beginning of each experimental session and consistently followed individual routes among feeding boxes. PMID:25517894

Owl monkeys (Aotus nigriceps and A. infulatus) follow routes instead of food-related cues during foraging in captivity.

PubMed

da Costa, Renata Souza; Bicca-Marques, Júlio César

2014-01-01

Foraging at night imposes different challenges from those faced during daylight, including the reliability of sensory cues. Owl monkeys (Aotus spp.) are ideal models among anthropoids to study the information used during foraging at low light levels because they are unique by having a nocturnal lifestyle. Six Aotus nigriceps and four A. infulatus individuals distributed into five enclosures were studied for testing their ability to rely on olfactory, visual, auditory, or spatial and quantitative information for locating food rewards and for evaluating the use of routes to navigate among five visually similar artificial feeding boxes mounted in each enclosure. During most experiments only a single box was baited with a food reward in each session. The baited box changed randomly throughout the experiment. In the spatial and quantitative information experiment there were two baited boxes varying in the amount of food provided. These baited boxes remained the same throughout the experiment. A total of 45 sessions (three sessions per night during 15 consecutive nights) per enclosure was conducted in each experiment. Only one female showed a performance suggestive of learning of the usefulness of sight to locate the food reward in the visual information experiment. Subjects showed a chance performance in the remaining experiments. All owl monkeys showed a preference for one box or a subset of boxes to inspect upon the beginning of each experimental session and consistently followed individual routes among feeding boxes.

Physical and numerical modeling of seawater intrusion in coastal aquifers

NASA Astrophysics Data System (ADS)

Crestani, Elena; Camporese, Matteo; Salandin, Paolo

2016-04-01

Seawater intrusion in coastal aquifers is a worldwide problem caused, among others factors, by aquifer overexploitation, rising sea levels, and climate changes. To limit the deterioration of both surface water and groundwater quality caused by saline intrusion, in recent years many research studies have been developed to identify possible countermeasures, mainly consisting of underground barriers. In this context, physical models are fundamental to study the saltwater intrusion, since they provide benchmarks for numerical model calibrations and for the evaluation of the effectiveness of general solutions to contain the salt wedge. This work presents a laboratory experiment where seawater intrusion was reproduced in a specifically designed sand-box. The physical model, built at the University of Padova, represents the terminal part of a coastal aquifer and consists of a flume 500 cm long, 30 cm wide and 60 cm high, filled for an height of 49 cm with glass beads characterized by a d50 of 0.6 mm and a uniformity coefficient d60/d10 ≈ 1.5. The resulting porous media is homogeneous, with porosity of about 0.37 and hydraulic conductivity of about 1.3×10-3 m/s. Upstream from the sand-box, a tank filled by freshwater provides the recharge to the aquifer. The downstream tank simulates the sea and red food dye is added to the saltwater to easily visualize the salt wedge. The volume of the downstream tank is about five times the upstream one, and, due to the small filtration discharge, salt concentration variations (i.e., water density variations) due to the incoming freshwater flow are negligible. The hydraulic gradient during the tests is constant, due to the fixed water level in the two tanks. Water levels and discharged flow rate are continuously monitored. The experiment presented here had a duration of 36 h. For the first 24 h, the saltwater wedge was let to evolve until quasi stationary condition was obtained. In the last 12 h, water withdrawal was carried out at a depth of 7 cm and at a distance of about 50 cm from the downstream tank by means of a draining trench. The experiment was monitored by means of photos collected with regular frequency as well as ERT (electrical resistivity tomography) with a joint surface and cross-borehole configuration, specifically designed for the laboratory flume. The experimental results are also compared with numerical simulations performed by the SUTRA software.

A Laboratory Experiment on the Evolution of a Sand Gravel Reach Under a Lack of Sediment Supply

NASA Astrophysics Data System (ADS)

Orru, C.; Chavarrias, V.; Ferrara, V.; Blom, A.

2014-12-01

A flume experiment was conducted to examine the evolution of a sand-gravel reach under a lack of sediment supply. The experimental data are used to validate a numerical sand-gravel model. A bed composed of a bi-modal sediment mixture is installed with a uniform slope and an imposed gradual fining pattern. Initially, the sand fraction gradually increases in streamwise direction until the bed is fully composed of sand. The water discharge and downstream water level were constant, and the sediment feed rate was equal to zero. The experiment was dominated by bed load, partial transport, and a subcritical flow regime was imposed. The flow rate was such that only sand was mobile (partial transport), which led to a coarsening over the upstream reach and a gradual reduction of the sediment transport rate during the experiment. New equipment was used to measure the evolution of the grain size distribution of the bed surface during the experiment over the entire flume using image analysis. In the upstream reach we observed a gradual coarsening over time and the formation of an armour layer, which resulted in a more abrupt transition in grain size of the bed surface. Bed degradation increased in streamwise direction. This is due to the initial streamwise increase in the availability of sand in the bed. The different volume fraction content of sand in the bed allowed for the gravel to sink more in the downstream part of the upstream reach. The sand reach suffered from a larger degradation. Finally, we see one reach dominated by sand, small bedforms, and a small bed slope, and a gravel reach dominated by a larger bed slope.

Sediment Transport During Three Controlled-Flood Experiments on the Colorado River Downstream from Glen Canyon Dam, with Implications for Eddy-Sandbar Deposition in Grand Canyon National Park

USGS Publications Warehouse

Topping, David J.; Rubin, David M.; Grams, Paul E.; Griffiths, Ronald E.; Sabol, Thomas A.; Voichick, Nicholas; Tusso, Robert B.; Vanaman, Karen M.; McDonald, Richard R.

2010-01-01

Three large-scale field experiments were conducted on the Colorado River downstream from Glen Canyon Dam in 1996, 2004, and 2008 to evaluate whether artificial (that is, controlled) floods released from the dam could be used in conjunction with the sand supplied by downstream tributaries to rebuild and sustainably maintain eddy sandbars in the river in Grand Canyon National Park. Higher suspended-sand concentrations during a controlled flood will lead to greater eddy-sandbar deposition rates. During each controlled flood experiment, sediment-transport and bed-sediment data were collected to evaluate sediment-supply effects on sandbar deposition. Data collection substantially increased in spatial and temporal density with each subsequent experiment. The suspended- and bed-sediment data collected during all three controlled-flood experiments are presented and analyzed in this report. Analysis of these data indicate that in designing the hydrograph of a controlled flood that is optimized for sandbar deposition in a given reach of the Colorado River, both the magnitude and the grain size of the sand supply must be considered. Because of the opposing physical effects of bed-sand area and bed-sand grain size in regulating suspended-sand concentration, larger amounts of coarser sand on the bed can lead to lower suspended-sand concentrations, and thus lower rates of sandbar deposition, during a controlled flood than can lesser amounts of finer sand on the bed. Although suspended-sand concentrations were higher at all study sites during the 2008 controlled-flood experiment (CFE) than during either the 1996 or 2004 CFEs, these higher concentrations were likely associated with more sand on the bed of the Colorado River in only lower Glen Canyon. More sand was likely present on the bed of the river in Grand Canyon during the 1996 CFE than during either the 2004 or 2008 CFEs. The question still remains as to whether sandbars can be sustained in the Colorado River in Grand Canyon National Park through use of controlled floods in conjunction with typical amounts and grain sizes of sand supplied by the tributaries that enter the Colorado River downstream from Glen Canyon Dam.

Mobile Satellite Services - A Survey of Business Needs

DTIC Science & Technology

1992-01-01

project. The Delta Clipper could fly either manned or unmanned from the White Sands Missile Range site in New Mexico. The vehicle "would carry 9888 Kg...Robert and Manning , Peter. Handbook of Social Science Methods. 1982, Ballinger Publications Co. 67 CHAPTER U ANALYSIS OF SURUEY Suruegs are an intricate...30303 4. Betz Laboratories 4636 Somerton Rd. Trevose, Pa. 19053 Great Lakes Chemical P 0 Box 2200 West Lafayette, In. 47906 Lubrizol 29400 Lakeland, Blvd

12. (Credit CBF) West end of McNeil Street Station in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. (Credit CBF) West end of McNeil Street Station in November 1911. The settling basins are visible on the far right. In the foreground is a pile of filter sand and several barrels of chemicals (probably lime or alum). The box car is delivering chemicals to storage in the west wing of the station. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

A Mobile App for Military Operational Entomology Pesticide Applications

DTIC Science & Technology

2014-09-01

combinations of equipment, formula - tions, and techniques for aerosol and residual pesticide treatments in 6 ecological regions against a range of mosquito, sand...materiel from the military inventory or commercial off-the-shelf products and precision use of equipment and formula - tions that maximize efficacy and... Veterinary Entomology, 1600 SW 23rd Drive, Gaines- ville, FL 32608. 2 Navy Entomology Center of Excellence, Naval Air Station, PO Box 43, Jacksonville, FL

2D fall of granular columns controlled by slow horizontal withdrawal of a retaining wall

NASA Astrophysics Data System (ADS)

Mériaux, C. A.

2006-12-01

This paper describes a series of experiments designed to investigate the fall of granular columns in quasi- static regime. Columns made of alternatively green and red sand layers were initially laid out in a box and then released when a retaining wall was set in slow motion with constant speed. The dependence of the dynamics of the fall on the initial aspect ratio of the columns, the velocity of the wall and the material properties was investigated within the quasi-static regime. A change in the behaviour of the columns was identified to be a function of the aspect ratio (height/length) of the initial sand column. Columns of high aspect ratio first subsided before sliding along failure planes, while columns of small aspect ratio were only observed to slide along failure planes. The transition between these two characteristic falls occurred regardless of the material and the velocity of the wall in the context of the quasi-static regime. When the final height and length of the piles were analyzed, we found power-law relations of the ratio of initial to final height and final run-out to initial length with the aspect ratio of the column. The dissipation of energy is also shown to increase with the run-out length of the pile until it reaches a plateau.

Threshold for sand mobility on Mars calibrated from seasonal variations of sand flux.

PubMed

Ayoub, F; Avouac, J-P; Newman, C E; Richardson, M I; Lucas, A; Leprince, S; Bridges, N T

2014-09-30

Coupling between surface winds and saltation is a fundamental factor governing geological activity and climate on Mars. Saltation of sand is crucial for both erosion of the surface and dust lifting into the atmosphere. Wind tunnel experiments along with measurements from surface meteorology stations and modelling of wind speeds suggest that winds should only rarely move sand on Mars. However, evidence for currently active dune migration has recently accumulated. Crucially, the frequency of sand-moving events and the implied threshold wind stresses for saltation have remained unknown. Here we present detailed measurements of Nili Patera dune field based on High Resolution Imaging Science Experiment images, demonstrating that sand motion occurs daily throughout much of the year and that the resulting sand flux is strongly seasonal. Analysis of the seasonal sand flux variation suggests an effective threshold for sand motion for application to large-scale model wind fields (1-100 km scale) of τ(s)=0.01±0.0015 N m(-2).

Destination memory for self-generated actions.

PubMed

El Haj, Mohamad

2016-10-01

There is a substantial body of literature showing memory enhancement for self-generated information in normal aging. The present paper investigated this outcome for destination memory or memory for outputted information. In Experiment 1, younger adults and older adults had to place (self-generated actions) and observe an experimenter placing (experiment-generated actions) items into two different destinations (i.e., a black circular box and a white square box). On a subsequent recognition task, the participants had to decide into which box each item had originally been placed. These procedures showed better destination memory for self- than experimenter-generated actions. In Experiment 2, destination and source memory were assessed for self-generated actions. Younger adults and older adults had to place items into the two boxes (self-generated actions), take items out of the boxes (self-generated actions), and observe an experimenter taking items out of the boxes (experiment-generated actions). On a subsequent recognition task, they had to decide into which box (destination memory)/from which box (source memory) each item had originally been placed/taken. For both populations, source memory was better than destination memory for self-generated actions, and both were better than source memory for experimenter-generated actions. Taken together, these findings highlight the beneficial effect of self-generation on destination memory in older adults.

Hydrogen sulfide removal from sediment and water in box culverts/storm drains by iron-based granules.

PubMed

Sun, J L; Shang, C; Kikkert, G A

2013-01-01

A renewable granular iron-based technology for hydrogen sulfide removal from sediment and water in box culverts and storm drains is discussed. Iron granules, including granular ferric hydroxide (GFH), granular ferric oxide (GFO) and rusted waste iron crusts (RWIC) embedded in the sediment phase removed aqueous hydrogen sulfide formed from sedimentary biological sulfate reduction. The exhausted iron granules were exposed to dissolved oxygen and this regeneration process recovered the sulfide removal capacities of the granules. The recovery is likely attributable to the oxidation of the ferrous iron precipitates film and the formation of new reactive ferric iron surface sites on the iron granules and sand particles. GFH and RWIC showed larger sulfide removal capacities in the sediment phase than GFO, likely due to the less ordered crystal structures on their surfaces. This study demonstrates that the iron granules are able to remove hydrogen sulfide from sediment and water in box culverts and storm drains and they have the potential to be regenerated and reused by contacting with dissolved oxygen.

Methods to Reduce Sand Ejecta from Projectile Impact - a Scaled Study with the Goal of Application to Depleted Uranium Penetrator Catch Boxes

DTIC Science & Technology

2012-04-01

caliber ammunition that were commercially available were used in this study: (1) lead ball (M33 ball) and (2) armor piercing ( machine hardened steel, M2 ...each test fire. The barrel will be a machined 0.50 caliber, 1 in 15-inch right twist bore, 29-inch length barrel without a muzzle brake; muzzle brake...11 Figure 15. Fired M2 50-caliber round

Augmenting Sand Simulation Environments through Subdivision and Particle Refinement

NASA Astrophysics Data System (ADS)

Clothier, M.; Bailey, M.

2012-12-01

Recent advances in computer graphics and parallel processing hardware have provided disciplines with new methods to evaluate and visualize data. These advances have proven useful for earth and planetary scientists as many researchers are using this hardware to process large amounts of data for analysis. As such, this has provided opportunities for collaboration between computer graphics and the earth sciences. Through collaboration with the Oregon Space Grant and IGERT Ecosystem Informatics programs, we are investigating techniques for simulating the behavior of sand. We are also collaborating with the Jet Propulsion Laboratory's (JPL) DARTS Lab to exchange ideas and gain feedback on our research. The DARTS Lab specializes in simulation of planetary vehicles, such as the Mars rovers. Their simulations utilize a virtual "sand box" to test how a planetary vehicle responds to different environments. Our research builds upon this idea to create a sand simulation framework so that planetary environments, such as the harsh, sandy regions on Mars, are more fully realized. More specifically, we are focusing our research on the interaction between a planetary vehicle, such as a rover, and the sand beneath it, providing further insight into its performance. Unfortunately, this can be a computationally complex problem, especially if trying to represent the enormous quantities of sand particles interacting with each other. However, through the use of high-performance computing, we have developed a technique to subdivide areas of actively participating sand regions across a large landscape. Similar to a Level of Detail (LOD) technique, we only subdivide regions of a landscape where sand particles are actively participating with another object. While the sand is within this subdivision window and moves closer to the surface of the interacting object, the sand region subdivides into smaller regions until individual sand particles are left at the surface. As an example, let's say there is a planetary rover interacting with our sand simulation environment. Sand that is actively interacting with a rover wheel will be represented as individual particles whereas sand that is further under the surface will be represented by larger regions of sand. The result of this technique allows for many particles to be represented without the computational complexity. In developing this method, we have further generalized these subdivision regions into any volumetric area suitable for use in the simulation. This is a further improvement of our method as it allows for more compact subdivision sand regions. This helps to fine tune the simulation so that more emphasis can be placed on regions of actively participating sand. We feel that through the generalization of our technique, our research can provide other opportunities within the earth and planetary sciences. Through collaboration with our academic colleagues, we continue to refine our technique and look for other opportunities to utilize our research.

Three-dimensional numerical simulations of crustal-scale wrenching using a non-linear failure criterion

NASA Astrophysics Data System (ADS)

Braun, Jean

1994-08-01

We have developed a three-dimensional finite element model to study wrench deformation of the crust regarded as an elasto-plastic material obeying Murrell's extension of Griffith's failure criterion. Numerical experiments using this model predict that the imposed basal wrenching is accommodated by an array of oblique Riedel-like shears and Y-shears (parallel to the direction of wrenching). The partitioning of deformation between the two types of structure depends on the width of the zone of imposed basal wrenching and the existence of a component of deformation in the x-direction (normal to the direction of wrenching). The Riedel shears are arranged in spiral-like structures that root into the basal wrench zone. In cross-section, the Riedel shears resemble wedge-shaped flower structures similar to those often observed in seismic cross-sections. The 'polarity' of the flower structures is positive (or palm-tree-like) in transpression experiments and negative (or tulip-like) in transtension experiments. The orientation of the Riedel shears throughout the crust obeys Mohr's hypothesis for incipient faulting combined with Murrell's failure criterion. The model also predicts plastic dilatancy inversely proportional to the square root of the confining pressure; this result agrees qualitatively with field observations and the results of sand-box experiments and quantitatively with direct measurement of dilatancy during high-pressure rock-deformation experiments.

Formation of Manganese Oxide Coatings onto Sand for Adsorption of Trace Metals from Groundwater.

PubMed

Tilak, A S; Ojewole, S; Williford, C W; Fox, G A; Sobecki, T M; Larson, S L

2013-11-01

Manganese oxide (MnO) occurs naturally in soil and has a high affinity for trace metals adsorption. In this work, we quantified the factors (pH; flow rate; use of oxidants such as bleach, HO, and O; initial Mn(II) concentrations; and two types of geologic media) affecting MnO coatings onto Ottawa and aquifer sand using batch and column experiments. The batch experiments consisted of manual and automated titration, and the column experiments mimicked natural MnO adsorption and oxidation cycles as a strategy for in situ adsorption. A Pb solution of 50 mg L was passed through MnO-coated sand at a flow rate of 4 mL min to determine its adsorption capacity. Batch experimental results showed that MnO coatings increased from pH 6 to 8, with maximum MnO coating occurring at pH 8. Regarding MnO coatings, bleach and O were highly effective compared with HO. The Ottawa sand had approximately twice the MnO coating of aquifer sand. The sequential increase in initial Mn(II) concentrations on both sands resulted in incremental buildup of MnO. The automated procedure enhanced MnO coatings by 3.5 times compared with manual batch experiments. Column results showed that MnO coatings were highly dependent on initial Mn(II) and oxidant concentrations, pH, flow rate, number of cycles (h), and the type of geologic media used. Manganese oxide coating exceeded 1700 mg kg for Ottawa sand and 130 mg kg for aquifer sand. The Pb adsorption exceeded 2200 mg kg for the Ottawa sand and 300 mg kg for the aquifer sand. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Mice housed on coal dust-contaminated sand: A model to evaluate the impacts of coal mining on health.

PubMed

Caballero-Gallardo, Karina; Olivero-Verbel, Jesus

2016-03-01

Coal dust is the most important air pollutant in coal mining in regards to producing deleterious health effects. It permeates the surrounding environment threatening public health. The aim of this study was to evaluate the toxic effects associated with exposure to sand contaminated with coal dust particles below 38 μm in diameter, obtained from a mineral sample collected in the largest coal mine in South America, La Loma, Cesar, Colombia. Sterilized sand was spiked with coal dust to obtain concentrations ranging from zero to 4% coal dust. To model natural exposure, mice were housed for eight weeks in boxes containing this mixture as bedding after which, they were euthanized and blood and tissue samples were collected. Real time PCR analysis revealed an increase in Cyp1A1 mRNA for living on sand with coal dust concentrations greater than 2% compared to mice living on sand without coal dust. Unexpectedly, for mice on coal dust-polluted sand, Sod1, Scd1 and Nqo1 hepatic mRNA were downregulated. The Comet assay in peripheral blood cells and the micronucleus test in blood smears, showed a significant potential genotoxic effect only at the highest coal dust concentration. Histopathological analysis revealed vascular congestion and peribronchial inflammation in the lungs. A dose-response relationship for the presence of hepatic steatosis, vacuolization and nuclei enlargements was observed in the exposed animals. The data suggest living on a soil polluted with coal dust induces molecular, cellular and histopathological changes in mice. Accordingly, the proposed model can be used to identify deleterious effects of exposure to coal dust deposited in soils that may pose health risks for surrounding wildlife populations. Copyright © 2016 Elsevier Inc. All rights reserved.

Experimental Observations of Localization Phenomena in Sands: Plane Strain Versus Triaxial Compression Conditions

NASA Technical Reports Server (NTRS)

Alshibli, Khalid A.; Batiste, Susan N.; Sture, Stein; Curreri, Peter A. (Technical Monitor)

2002-01-01

A comprehensive experimental investigation was conducted to investigate the effects of loading condition and confining pressure on strength properties and instability phenomena in sands. A uniform sub-rounded to rounded natural silica sand known as F-75 Ottawa sand was used in the investigation. The results of a series on Conventional Triaxial Compression (CTC) experiments tested under very low confining pressures (0.05 - 1.30) kPa tested in a Microgravity environment abroad the NASA Space Shuttle are presented in addition to the results similar specimens tested in terrestrial laboratory to investigate the effect of confining pressure on the constitutive behavior of sands. The behavior of the CTC experiments is compared with the results of Plane Strain (PS) experiments. Computed tomography and other digital imaging techniques were used to study the development and evolution of shear bands.

Survival potential of Escherichia coli and Enterococci in subtropical beach sand: implications for water quality managers.

PubMed

Hartz, A; Cuvelier, M; Nowosielski, K; Bonilla, T D; Green, M; Esiobu, N; McCorquodale, D S; Rogerson, A

2008-01-01

Fecal bacteria have traditionally been used as indicator organisms to monitor the quality of recreational waters. Recent work has questioned the robustness of traditional indicators, particularly at seawater bathing beaches. For example, a study of Florida beaches found unexpectedly high abundances of Escherichia coli, fecal coliforms, and enterococci in beach sand. The aim of the present study was to explain these abundances by assessing the survival of E. coli and enterococci in beach sand relative to seawater. We used a combination of quantitative laboratory mesocosm experiments and field observations. Results suggested that E. coli and enterococci exhibited increased survivability and growth in sand relative to seawater. Because fecal bacteria are capable of replicating in sand, at least under controlled laboratory conditions, the results suggest that sand may be an important reservoir of metabolically active fecal organisms. Experiments with "natural" mesocosms (i.e., unsterilized sand or water rich in micropredators and native bacteria) failed to show the same increases in fecal indicators as was found in sterile sand. It is postulated that this was due to predation and competition with indigenous bacteria in these "natural" systems. Nonetheless, high populations of indicators were maintained and recovered from sand over the duration of the experiment as opposed to the die-off noted in water. Indicator bacteria may wash out of sand into shoreline waters during weather and tidal events, thereby decreasing the effectiveness of these indicators as predictors of health risk and complicating the interpretations for water quality managers.

Effect of Additives on Green Sand Molding Properties using Design of Experiments and Taguchi's Quality Loss Function - An Experimental Study

NASA Astrophysics Data System (ADS)

Desai, Bhagyashree; Mokashi, Pavani; Anand, R. L.; Burli, S. B.; Khandal, S. V.

2016-09-01

The experimental study aims to underseek the effect of various additives on the green sand molding properties as a particular combination of additives could yield desired sand properties. The input parameters (factors) selected were water and powder (Fly ash, Coconut shell and Tamarind) in three levels. Experiments were planned using design of experiments (DOE). On the basis of plans, experiments were conducted to understand the behavior of sand mould properties such as compression strength, shear strength, permeability number with various additives. From the experimental results it could be concluded that the factors have significant effect on the sand properties as P-value found to be less than 0.05 for all the cases studied. The optimization based on quality loss function was also performed. The study revealed that the quality loss associated with the tamarind powder was lesser compared to other additives selected for the study. The optimization based on quality loss function and the parametric analysis using ANOVA suggested that the tamarind powder of 8 gm per Kg of molding sand and moisture content of 7% yield better properties to obtain sound castings.

Installation Restoration Program Phase 2. Confirmation/Quantification. Stage 1. Volume 1.

DTIC Science & Technology

1986-10-10

FIGUR 1- EEA LNO EFIG I AiNLanfl GUARD BASESHOWING PHSE II INVTIGTOIE I 1- ........ Site No. - I MAA Site No.Northwest Landfill TS Site.No.4 West...Protective Steel PVC Cap Flush Mount in Casing Plastic Nelson Valve Box Land Surface PVC Cap . Cement Grout 0 L n aBentonite Pellet 4" Diameter Seal...12.0 feet BLS. Clays of high plasticity predominate in all three wells. No sand lenses were encountered and the topsoil at all three well locations is

The Evaluation of Small Arms Effectiveness Criteria, Volume I

DTIC Science & Technology

1975-05-01

UNCLASSIFIED AD NUMBER ADB004382 NEW LIMITATION CHANGE TO Approved for public release, distribution unlimited FROM Distribution authorized to U.S...aimedSand pointed fire E-14 E-4 Frequency distribution of sizes of M16 and BAR bursts of automatic fire E-16 SE-5 Percent of times each range bracket...defense range F-10 F-4 Weapon-signature simuilator F-15 1 F-5 Target components in armored target box F-17 F-6 Portable round counter for the M16 rifle

Nine Optical Black-Box Experiments for Lower-Secondary Students

ERIC Educational Resources Information Center

Rode, Henning; Friege, Gunnar

2017-01-01

In this paper a sequence of nine, easy to manufacture optical black-box experiments with increasing levels of difficulty, and supportive frameworks for physics classes are introduced. They have been evaluated in a lower-secondary school at the end of optics lessons. A black-box is a kind of experimental task where the inner structure is not…

John Henry--The Steel Driving Man

ERIC Educational Resources Information Center

Murphy, David E.; Gulley, Laura L.

2005-01-01

The story of John Henry provided the setting for sixth-grade class to participate in a John Henry Day of mathematics experiments. The students collected data from experiments where students competed against machines and technology. The student analyzed the data by comparing two box plots, a box plot of human data, and a box plot of machine or…

The Shell Seeker: What Is the Quantity of Shell in the Lido di Venezia Sand? A Calibration DRIFTS Experiment

ERIC Educational Resources Information Center

Pezzolo, Alessandra De Lorenzi

2011-01-01

In this experiment, students are given a fanciful application of the standard addition method to evaluate the approximate quantity of the shell component in a sample of sand collected on the Lido di Venezia seashore. Several diffuse reflectance infrared Fourier transform (DRIFT) spectra are recorded from a sand sample before and after addition of…

Site fidelity, mate fidelity, and breeding dispersal in American kestrels

USGS Publications Warehouse

Steenhof, K.; Peterson, B.E.

2009-01-01

We assessed mate fidelity, nest-box fidelity, and breeding dispersal distances of American Kestrels (falco sparverius) nesting in boxes in southwestern Idaho from 1990 through 2006. Seventy-seven percent of boxes had different males and 87% had different females where nest-box occupants were identified in consecutive years. High turnover rates were partly a result of box-switching. Forty-eight percent of males and 58% of females that nested within the study area in successive years used different boxes. The probability of changing boxes was unrelated to gender, nesting success in the prior year, or years of nesting experience. Breeding dispersal distances for birds that moved to different boxes averaged 2.2 km for males (max = 22 km) and 3.2 km for females (max = 32 km). Approximately 70% of birds that nested in consecutive years on the study area had a different mate in the second year. Mate fidelity was related to box fidelity but not to prior nesting success or years of nesting experience. Mate changes occurred 32% of the time when the previous mate was known to be alive and nesting in the area. Kestrels that switched mates and boxes did not improve or decrease their subsequent nesting success. Kestrels usually switched to mates with less experience and lower lifetime productivity than their previous mates. The costs of switching boxes and mates were low, and there were no obvious benefits to fidelity. The cost of "waiting" for a previous mate that might have died could be high in species with high annual mortality.

The effects of sexual experience and estrus on male-seeking motivated behavior in the female rat

PubMed Central

Nofrey, Barbara; Rocha, Beatriz; Lopez, Hassan H.; Ettenberg, Aaron

2008-01-01

Ovariectomized (OVX) female rats were trained to traverse a straight alley and return to a goal box where they had previously encountered a male rat, a female rat or an empty goal box. The time required to run the alley was used as an index of the subjects’ motivation to re-engage the goal box target. Subjects were tested in both estrus and non-estrus, first sexually naïve and then again after sexual experience. Female rats ran most quickly for a male target, most slowly for an empty goal box, and at intermediate speeds for a female target. Sexual experience tended to slow run times for all but male targets. Estrus enhanced approach behavior for males and an empty goal box, but tended to slow the approach toward females, both before and after sexual experience. This latter finding was further investigated in a second experiment in which sexually naïve OVX females were tested during estrus and non-estrus in a locomotor activity apparatus, a runway with an empty goal box, and an open field. Estrus produced no changes in spontaneous locomotion either in the activity box or the open field, but decreased run times in the alley and increased the number of center-square entries in the open-field. Thus, estrus produces increases in sexual motivation that selectively enhance exploratory, presumably male-seeking behavior, but not simple spontaneous locomotion. PMID:18761024

The Box Task: A tool to design experiments for assessing visuospatial working memory.

PubMed

Kessels, Roy P C; Postma, Albert

2017-09-15

The present paper describes the Box Task, a paradigm for the computerized assessment of visuospatial working memory. In this task, hidden objects have to be searched by opening closed boxes that are shown at different locations on the computer screen. The set size (i.e., number of boxes that must be searched) can be varied and different error scores can be computed that measure specific working memory processes (i.e., the number of within-search and between-search errors). The Box Task also has a developer's mode in which new stimulus displays can be designed for use in tailored experiments. The Box Task comes with a standard set of stimulus displays (including practice trials, as well as stimulus displays with 4, 6, and 8 boxes). The raw data can be analyzed easily and the results of individual participants can be aggregated into one spreadsheet for further statistical analyses.

Prestressing force monitoring method for a box girder through distributed long-gauge FBG sensors

NASA Astrophysics Data System (ADS)

Chen, Shi-Zhi; Wu, Gang; Xing, Tuo; Feng, De-Cheng

2018-01-01

Monitoring prestressing forces is essential for prestressed concrete box girder bridges. However, the current monitoring methods used for prestressing force were not applicable for a box girder neither because of the sensor’s setup being constrained or shear lag effect not being properly considered. Through combining with the previous analysis model of shear lag effect in the box girder, this paper proposed an indirect monitoring method for on-site determination of prestressing force in a concrete box girder utilizing the distributed long-gauge fiber Bragg grating sensor. The performance of this method was initially verified using numerical simulation for three different distribution forms of prestressing tendons. Then, an experiment involving two concrete box girders was conducted to study the feasibility of this method under different prestressing levels preliminarily. The results of both numerical simulation and lab experiment validated this method’s practicability in a box girder.

“Insight” in Pigeons: Absence of Means-End Processing in Displacement Tests

PubMed Central

Cook, Robert G.; Fowler, Catherine

2013-01-01

The understanding of functional relations between action and consequence is a critical component of intelligence. To examine this linkage in pigeons, we investigated their understanding of the relations of the elements tested in an extension of Köhler's box-stacking task to this species (Epstein et al. 1984). In the experiments, the pigeons had to move a spatially displaced box under an out-of-reach target. Experiment 1 successfully replicated and extended the previous finding showing that when separately trained to move a box and stand on it to peck the target, pigeons can synthesize these behaviors to solve the single-box displacement problem quickly on their first attempt. Experiment 2 tested whether pigeons, when given a simultaneous choice among two boxes with identical reinforcement histories, would selectively choose the box with the correct functional affordance (i.e., permitting standing) to solve the problem rather than a nonfunctional one. Their extensive, equivalent, and undirected behavior in moving both boxes during these tests suggests the pigeons did not possess a means-end understanding of the functional properties of the boxes. Instead, their results were consistent with an analysis of their earlier synthetic behavior as being due to the temporal and spatial relations of the physical elements in the task and their prior learned behaviors. PMID:23774955

"Insight" in pigeons: absence of means-end processing in displacement tests.

PubMed

Cook, Robert G; Fowler, Catherine

2014-03-01

The understanding of functional relations between action and consequence is a critical component of intelligence. To examine this linkage in pigeons, we investigated their understanding of the relations of the elements tested in an extension of Köhler's box stacking task to this species. In the experiments, the pigeons had to move a spatially displaced box under an out-of-reach target. Experiment 1 successfully replicated and extended the previous finding showing that when separately trained to move a box and stand on it to peck the target, pigeons can synthesize these behaviors to solve the single-box displacement problem quickly on their first attempt. Experiment 2 tested whether pigeons, when given a simultaneous choice between two boxes with identical reinforcement histories, would selectively choose the box with the correct functional affordance (i.e., permitting standing) to solve the problem rather than a non-functional one. Their extensive, equivalent, and undirected behavior in moving both boxes during these tests suggests the pigeons did not possess a means-end understanding of the functional properties of the boxes. Instead, their results were consistent with an analysis of their earlier synthetic behavior as being due to the temporal and spatial relations of the physical elements in the task and their prior learned behaviors.

Spatial ecology and behavior of eastern box turtles on the hardwood ecosystem experiment: pre-treatment results

Treesearch

Andrea F. Currylow; Brian J. MacGowan; Rod N. Williams

2013-01-01

To understand better how eastern box turtles (Terrapene carolina carolina) are affected by forest management practices, we monitored movements of box turtles prior to silvicultural treatments within the Hardwood Ecosystem Experiment (HEE) in Indiana. During 2007 and 2008, we tracked 23-28 turtles on six units of the HEE. Estimated minimum convex...

Bonn eXperimental System (BoXS): An open-source platform for interactive experiments in psychology and economics.

PubMed

Seithe, Mirko; Morina, Jeronim; Glöckner, Andreas

2016-12-01

The increased interest in complex-interactive behavior on the one hand and the cognitive and affective processes underlying behavior on the other are a challenge for researchers in psychology and behavioral economics. Research often necessitates that participants strategically interact with each other in dyads or groups. At the same time, to investigate the underlying cognitive and affective processes in a fine-grained manner, not only choices but also other variables such as decision time, information search, and pupil dilation should be recorded. The Bonn eXperimental System (BoXS) introduced in this article is an open-source platform that allows interactive as well as non-interactive experiments to be conducted while recording process measures very efficiently and completely browser-based. In the current version, BoXS has particularly been extended to enable conducting interactive eye-tracking and mouse-tracking experiments. One core advantage of BoXS is its simplicity. Using BoXS does not require prior installation for both experimenters and participants, which allows for running studies outside the laboratory and over the internet. Learning to program for BoXS is easy even for researchers without previous programming experience.

Cesium migration in saturated silica sand and Hanford sediments as impacted by ionic strength.

PubMed

Flury, Markus; Czigány, Szabolcs; Chen, Gang; Harsh, James B

2004-07-01

Large amounts of 137Cs have been accidentally released to the subsurface from the Hanford nuclear site in the state of Washington, USA. The cesium-containing liquids varied in ionic strengths, and often had high electrolyte contents, mainly in the form of NaNO3 and NaOH, reaching concentrations up to several moles per liter. In this study, we investigated the effect of ionic strengths on Cs migration through two types of porous media: silica sand and Hanford sediments. Cesium sorption and transport was studied in 1, 10, 100, and 1000 mM NaCl electrolyte solutions at pH 10. Sorption isotherms were constructed from batch equilibrium experiments and the batch-derived sorption parameters were compared with column breakthrough curves. Column transport experiments were analyzed with a two-site equilibrium-nonequilibrium model. Cesium sorption to the silica sand in batch experiments showed a linear sorption isotherm for all ionic strengths, which matched well with the results from the column experiments at 100 and 1000 mM ionic strength; however, the column experiments at 1 and 10 mM ionic strength indicated a nonlinear sorption behavior of Cs to the silica sand. Transport through silica sand occurred under one-site sorption and equilibrium conditions. Cesium sorption to Hanford sediments in both batch and column experiments was best described with a nonlinear Freundlich isotherm. The column experiments indicated that Cs transport in Hanford sediments occurred under two-site equilibrium and nonequilibrium sorption. The effect of ionic strength on Cs transport was much more pronounced in Hanford sediments than in silica sands. Effective retardation factors of Cs during transport through Hanford sediments were reduced by a factor of 10 when the ionic strength increased from 100 to 1000 mM; for silica sand, the effective retardation was reduced by a factor of 10 when ionic strength increased from 1 to 1000 mM. A two order of magnitude change in ionic strength was needed in the silica sand to observe the same change in Cs retardation as in Hanford sediments. Copyright 2003 Elsevier B.V.

Dual leakoff beehavior in hydraulic fracturing of tight, lenticular gas sands

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

Warpinski, N.R.

Stimulation experiments conducted in anisotropic, naturally fractured, tight, lenticular, gas sandstones have shown the existence of a dual leakoff phenomenon. Below a threshold, leakoff increases by a factor of 50, slurries dehydrate rapidly, and screenouts occur in minutes. The leakoff has been shown to be controllable to some extent with 100-mesh sand. Results of three stimulation experiments are presented; three include a treatment that screened out, a minifrac experiment that showed the effectiveness of 100-mesh sand, and a final successful stimulation. 30 refs., 14 figs., 6 tabs.

Revisiting the horizontal redistribution of water in soils: Experiments and numerical modeling.

PubMed

Zhuang, L; Hassanizadeh, S M; Kleingeld, P J; van Genuchten, M Th

2017-09-01

A series of experiments and related numerical simulations were carried out to study one-dimensional water redistribution processes in an unsaturated soil. A long horizontal Plexiglas box was packed as homogenously as possible with sand. The sandbox was divided into two sections using a very thin metal plate, with one section initially fully saturated and the other section only partially saturated. Initial saturation in the dry section was set to 0.2, 0.4, or 0.6 in three different experiments. Redistribution between the wet and dry sections started as soon as the metal plate was removed. Changes in water saturation at various locations along the sandbox were measured as a function of time using a dual-energy gamma system. Also, air and water pressures were measured using two different kinds of tensiometers at various locations as a function of time. The saturation discontinuity was found to persist during the entire experiments, while observed water pressures were found to become continuous immediately after the experiments started. Two models, the standard Richards equation and an interfacial area model, were used to simulate the experiments. Both models showed some deviations between the simulated water pressures and the measured data at early times during redistribution. The standard model could only simulate the observed saturation distributions reasonably well for the experiment with the lowest initial water saturation in the dry section. The interfacial area model could reproduce observed saturation distributions of all three experiments, albeit by fitting one of the parameters in the surface area production term.

Rheological measurements in reduced gravity

NASA Astrophysics Data System (ADS)

Bakhtiyarov, Sayavur I.; Overfelt, Ruel A.

1999-01-01

Rheology of fluidized beds and settling suspensions were studied experimentally in a series of reduced gravity parabolic flights aboard NASA's KC-135 aircraft. Silica sands of two different size distributions were fluidized by air. The slurries were made using silica sand and Glycerol solution. The experimental set up incorporated instrumentation to measure the air flow rate, the pressure drop and the apparent viscosity of the fluidized sand and sand suspensions at a wide range of the shear rates. The fluidization chamber and container had transparent walls to allow visualization of the structure changes involved in fluidization and in Couette flow in reduced gravity. Experiments were performed over a broad range of gravitational accelerations including microgravity and double gravity conditions. The results of the flight and ground experiments reveal significant differences in overall void fraction and hence in the apparent viscosity of fluidized sand and sand suspensions under microgravity as compared to one-g conditions.

Non-robust numerical simulations of analogue extension experiments

NASA Astrophysics Data System (ADS)

Naliboff, John; Buiter, Susanne

2016-04-01

Numerical and analogue models of lithospheric deformation provide significant insight into the tectonic processes that lead to specific structural and geophysical observations. As these two types of models contain distinct assumptions and tradeoffs, investigations drawing conclusions from both can reveal robust links between first-order processes and observations. Recent studies have focused on detailed comparisons between numerical and analogue experiments in both compressional and extensional tectonics, sometimes involving multiple lithospheric deformation codes and analogue setups. While such comparisons often show good agreement on first-order deformation styles, results frequently diverge on second-order structures, such as shear zone dip angles or spacing, and in certain cases even on first-order structures. Here, we present finite-element experiments that are designed to directly reproduce analogue "sandbox" extension experiments at the cm-scale. We use material properties and boundary conditions that are directly taken from analogue experiments and use a Drucker-Prager failure model to simulate shear zone formation in sand. We find that our numerical experiments are highly sensitive to numerous numerical parameters. For example, changes to the numerical resolution, velocity convergence parameters and elemental viscosity averaging commonly produce significant changes in first- and second-order structures accommodating deformation. The sensitivity of the numerical simulations to small parameter changes likely reflects a number of factors, including, but not limited to, high angles of internal friction assigned to sand, complex, unknown interactions between the brittle sand (used as an upper crust equivalent) and viscous silicone (lower crust), highly non-linear strain weakening processes and poor constraints on the cohesion of sand. Our numerical-analogue comparison is hampered by (a) an incomplete knowledge of the fine details of sand failure and sand properties, and (b) likely limitations to the use of a continuum Drucker-Prager model for representing shear zone formation in sand. In some cases our numerical experiments provide reasonable fits to first-order structures observed in the analogue experiments, but the numerical sensitivity to small parameter variations leads us to conclude that the numerical experiments are not robust.

Advanced Techniques for Simulating the Behavior of Sand

NASA Astrophysics Data System (ADS)

Clothier, M.; Bailey, M.

2009-12-01

Computer graphics and visualization techniques continue to provide untapped research opportunities, particularly when working with earth science disciplines. Through collaboration with the Oregon Space Grant and IGERT Ecosystem Informatics programs we are developing new techniques for simulating sand. In addition, through collaboration with the Oregon Space Grant, we’ve been communicating with the Jet Propulsion Laboratory (JPL) to exchange ideas and gain feedback on our work. More specifically, JPL’s DARTS Laboratory specializes in planetary vehicle simulation, such as the Mars rovers. This simulation utilizes a virtual "sand box" to test how planetary rovers respond to different terrains while traversing them. Unfortunately, this simulation is unable to fully mimic the harsh, sandy environments of those found on Mars. Ideally, these simulations should allow a rover to interact with the sand beneath it, particularly for different sand granularities and densities. In particular, there may be situations where a rover may become stuck in sand due to lack of friction between the sand and wheels. In fact, in May 2009, the Spirit rover became stuck in the Martian sand and has provided additional motivation for this research. In order to develop a new sand simulation model, high performance computing will play a very important role in this work. More specifically, graphics processing units (GPUs) are useful due to their ability to run general purpose algorithms and ability to perform massively parallel computations. In prior research, simulating vast quantities of sand has been difficult to compute in real-time due to the computational complexity of many colliding particles. With the use of GPUs however, each particle collision will be parallelized, allowing for a dramatic performance increase. In addition, spatial partitioning will also provide a speed boost as this will help limit the number of particle collision calculations. However, since the goal of this research is to simulate the look and behavior of sand, this work will go beyond simple particle collision. In particular, we can continue to use our parallel algorithms not only on single particles but on particle “clumps” that consist of multiple combined particles. Since sand is typically not spherical in nature, these particle “clumps” help to simulate the coarse nature of sand. In a simulation environment, multiple combined particles could be used to simulate the polygonal and granular nature of sand grains. Thus, a diversity of sand particles can be generated. The interaction between these particles can then be parallelized using GPU hardware. As such, this research will investigate different graphics and physics techniques and determine the tradeoffs in performance and visual quality for sand simulation. An enhanced sand model through the use of high performance computing and GPUs has great potential to impact research for both earth and space scientists. Interaction with JPL has provided an opportunity for us to refine our simulation techniques that can ultimately be used for their vehicle simulator. As an added benefit of this work, advancements in simulating sand can also benefit scientists here on earth, especially in regard to understanding landslides and debris flows.

Simulating Sand Behavior through Terrain Subdivision and Particle Refinement

NASA Astrophysics Data System (ADS)

Clothier, M.

2013-12-01

Advances in computer graphics, GPUs, and parallel processing hardware have provided researchers with new methods to visualize scientific data. In fact, these advances have spurred new research opportunities between computer graphics and other disciplines, such as Earth sciences. Through collaboration, Earth and planetary scientists have benefited by using these advances in hardware technology to process large amounts of data for visualization and analysis. At Oregon State University, we are collaborating with the Oregon Space Grant and IGERT Ecosystem Informatics programs to investigate techniques for simulating the behavior of sand. In addition, we have also been collaborating with the Jet Propulsion Laboratory's DARTS Lab to exchange ideas on our research. The DARTS Lab specializes in the simulation of planetary vehicles, such as the Mars rovers. One aspect of their work is testing these vehicles in a virtual "sand box" to test their performance in different environments. Our research builds upon this idea to create a sand simulation framework to allow for more complex and diverse environments. As a basis for our framework, we have focused on planetary environments, such as the harsh, sandy regions on Mars. To evaluate our framework, we have used simulated planetary vehicles, such as a rover, to gain insight into the performance and interaction between the surface sand and the vehicle. Unfortunately, simulating the vast number of individual sand particles and their interaction with each other has been a computationally complex problem in the past. However, through the use of high-performance computing, we have developed a technique to subdivide physically active terrain regions across a large landscape. To achieve this, we only subdivide terrain regions where sand particles are actively participating with another object or force, such as a rover wheel. This is similar to a Level of Detail (LOD) technique, except that the density of subdivisions are determined by their proximity to the interacting object or force with the sand. To illustrate an example, as a rover wheel moves forward and approaches a particular sand region, that region will continue to subdivide until individual sand particles are represented. Conversely, if the rover wheel moves away, previously subdivided sand regions will recombine. Thus, individual sand particles are available when an interacting force is present but stored away if there is not. As such, this technique allows for many particles to be represented without the computational complexity. We have also further generalized these subdivision regions in our sand framework into any volumetric area suitable for use in the simulation. This allows for more compact subdivision regions and has fine-tuned our framework so that more emphasis can be placed on regions of actively participating sand. We feel that this increases the framework's usefulness across scientific applications and can provide for other research opportunities within the earth and planetary sciences. Through continued collaboration with our academic partners, we continue to build upon our sand simulation framework and look for other opportunities to utilize this research.

Effects of porous media preparation on bacteria transport through laboratory columns.

PubMed

Brown, Derick G; Stencel, Joseph R; Jaffé, Peter R

2002-01-01

Bacterial and colloid transport experiments related to environmental systems are typically performed in the laboratory, with sand often used as the porous media. In order to prepare the sand, mechanical sieving is frequently used to tighten the sand grain size distribution. However, mechanical sieving has been reported to provide insufficient repeatability between identical colloidal transport experiments. This work examined the deficiencies of mechanical sieving with respect to bacterial transport through sand columns. It was found that sieving with standard brass sieves (1) contaminates the sand with copper and zinc as a linear function of sieving time and (2) inefficiently sizes sand grains below 300 microm (the largest size examined in this study) due to rapid clogging of the sieves. A procedure was developed that allows utilization of brass sieves for sizing the sand grains and removes the metal contamination introduced from the sieves. Bacterial transport experiments utilizing this column preparation procedure gave repeatable breakthrough curves. Further examination of the effects of these treatments on bacterial transport showed interesting results. First, it was found that the metal contamination did not affect the clean-bed bacterial transport. Second. it was found that variations of the column flushing procedure did not alter the clean-bed breakthrough of the bacteria, but did alter the inter-particle blocking. Finally, it was found that the shape of the sand grains (oblong vs. rounded) significantly alters the bacterial transport. with the transport being dominated by the smallest dimension of the oblong grains.

Bioclogging Effects Relevant to In-Situ Bioremediation of Organic Contaminants

NASA Astrophysics Data System (ADS)

Bielefeldt, A. R.; Illangasekare, T.

2002-05-01

This presentation will summarize 5 years of laboratory experiments investigating the effects of biodegradation of organic contaminants on the hydrodynamic properties of saturated sand due to biomass accumulation. The contaminants studied included naphthalene, decane, diesel fuel, propylene glycol, and aircraft de-icing fluid (ADF). Most of the experiments were conducted in columns (~6 cm dia x 15 cm L). A wide range of environmental conditions were simulated including low to high organic loading (1.2 to 38,000 mg C/kg dry sand/d), various nutrient concentrations (C:N 3:1 to 5424:1), seepage velocity (0.5-11 m/d), and sand size (average diameter 0.19, 0.32, 0.49 mm). Changes in the hydraulic conductivity and dispersivity of the media over time and the biomass distribution in the sand at the end of the experiments were measured. In general, the hydraulic conductivity in the columns declined over time until a steady-state minimum was reached when the new biogrowth was balanced by endogenous decay and shear stress losses from the system. The minimum conductivity was generally 2 to 4 orders of magnitude below that of the clean sand. Dispersivity was evaluated using bromide tracer tests and monitoring the break-through curves. Dispersivity after biomass growth was always higher than that of the clean sand (up to 10x), but trends over time did not always consistently increase. Under selected conditions the dispersivity initially increased and then decreased, although never achieving a level below that of the clean sand. Final biomass concentrations in the sand at steady state ranged from 0.1 to 10 mg dry weight/g dry sand. In some experiments the biomass was evenly distributed through the sand while in others significantly more biomass was present at the column inlet. Some experiments were also conducted in larger 2-D tanks (122 cm L x 46 cm H x 6 cm W) which allowed the groundwater flow to route around local areas of bioclogging as would be likely to occur in subsurface environments. The implications of ignoring bioclogging effects of the magnitude measured in the experimental systems when predicting contaminant plumes in the subsurface will be illustrated using simple models that incorporate biokinetics and hydrodynamic effects. The models will show the importance of including bioclogging effects when designing enhanced in-situ bioremediation systems.

Analysis of Time-Series Quasi-Experiments. Final Report.

ERIC Educational Resources Information Center

Glass, Gene V.; Maguire, Thomas O.

The objective of this project was to investigate the adequacy of statistical models developed by G. E. P. Box and G. C. Tiao for the analysis of time-series quasi-experiments: (1) The basic model developed by Box and Tiao is applied to actual time-series experiment data from two separate experiments, one in psychology and one in educational…

A Temporal and Spatial Analysis of Wave-Generated Foam Patterns in the Surf Zone

DTIC Science & Technology

2017-01-10

region, rectange B depicts the gap region, rectangle C is the plunging breaker, circle D represents a foam hole, rectangle E depict a top box...structures: The hidden skeleton of fluid flows . Phys. Today, 66, 41–47. 35 V. CONCLUSION Unique surf zone imagery, acquired from a UAV at Sand City...MacMahan, J. H., E . B . Thornton, T. P. Stanton, and A. J. H. M. Reniers, 2005: RIPEX: Observations of a rip current system. Mar. Geol., 218, 113–134

Al SahawaThe Awakening Volume III: Al Anbar Province, Western Euphrates River Valley, Area of Operations Denver- Transcripts

DTIC Science & Technology

2016-05-01

could not be stopped or stalled . On 1 September 2008, conditions were stable enough to hand over the province to the Iraqis Government. What happened...international jihadists]. On any given day, they’d play well together in the sand box; that probably wasn’t a good day for us. Other days they’d fight...roam around up there, by all means, go for it, just let us know for purposes of de-confliction. You’re free to operate anywhere ten clicks north of the

STS-72 Mission Specialist Koichi Wakata during ASCAN training

NASA Image and Video Library

1995-01-09

S95-00353 (12-14 September 1992) --- Several 1992 astronaut candidates brush the sand and gravel off one another following one of several phases of parachute familiarization and survival training at Vance Air Force Base in Oklahoma. Recognizable in the picture are Wendy B. Lawrence, Michael E. Lopez-Alegria, Chris A. Hadfield, Winston E. Scott and Koichi Wakata. The trainees had just completed an exercise, which required their jumping off a box into a gravel pit, in order to familiarize them the proper way to meet the ground following an emergency parachute drop.

Influence of Air Discontinuity and Wall Effects on the Measurements of Hydraulic Parameters Under Dynamic Conditions

NASA Astrophysics Data System (ADS)

Looms, M. C.; Jensen, K. H.; Wildenschild, D.; Christensen, B. S.; Gudbjerg, J.

2003-12-01

Both dynamic (one-step) and semi-static (syringe pump) outflow experiments were carried out in the lab to test whether the resulting retention characteristics differed according to experiment type. Three sands of varying uniformity and coarseness were packed in a cylindrical sample holder. Compressed air was used to control the air phase pressure, while water was allowed to drain at atmospheric pressure from the outlet at the bottom of the sample. During the outflow experiments the capillary pressure was measured within the sample holder using a tensiometer connected to a pressure transducer. A medical CT-scanner was used to visualize and quantify the outflow patterns within the sand matrix during selected outflow experiments. Positive vertical shifts in capillary pressure during dynamic experiments were found in all three sand types at saturations close to porosity. The size and shape of the shifts corresponded with the dynamic effects found in previous work on the topic. Furthermore, the shifts were slightly greater in the coarsest and most uniform sand type. Numerical simulations of the one-step experiments using HYDRUS1D and T2VOC showed, however, that one of the basic assumptions when calculating the capillary pressure was most likely violated. The air phase could not be considered to be continuous at all times, and assuming this to be the case would result in positive shifts of the retention curves when running T2VOC. The results of using the CT-scanner showed the importance of achieving a homogeneous packing, since the investigated sand packing turned out to have an area at the edge of the sample holder with a higher porosity. This caused the edge to control the initial drainage. Therefore, the data collected at high saturations could not be expected to adequately describe the hydraulic properties of the inner sand. We also found that the time at which the inner sand commenced drainage coincided with a jump in capillary pressure for the resulting measured retention curve.

Small-scale modelling of cementation by descending silica-bearing fluids: Explanation of the origin of arenitic caves in South American tepuis

NASA Astrophysics Data System (ADS)

Aubrecht, R.; Lánczos, T.; Schlögl, J.; Audy, M.

2017-12-01

Geoscientific research was performed on South American table mountains (tepuis) and in their sandstone cave systems. To explain speleogenesis in these poorly soluble rocks, two theories were introduced: a) arenization theory implying selective weathering of quartz along grain boundaries and releasing of sand grains, b) selective lithification theory implying cementation by descending silica-bearing fluid flow. The latter theory presumes that the descending fluid flow becomes unstable on the interface between two layers with different porosity and splits to separate flow channels (so-called ;finger flow;). The arenites outside these channels remain uncemented. To verify the latter theory, small-scale modelling was performed, using layered sands and sodium-silicate solution. Fine to medium sand was used (0.08-0.5 mm), along with a coarse sand fraction (0.5-1.5 mm). The sands were layered and compacted in a transparent plastic boxes. Three liters of sodium-silicate solution (so-called water glass) were left to drip for several hours to the top of the sediment. The fine-grained layers were perfectly laterally impregnated, whereas the descending fluid flows split to ;fingers; in the coarse-grained layers due their higher hydraulic conductivity. This small-scale laboratory simulation mimics the real diagenesis by descending silica-bearing fluids and matches the real phenomena observed on the tepuis. The resulting cemented constructions closely mimic many geomorphological features observed on tepuis and inside their caves, e.g. ;finger-flow; pillars, overhangs, imperfectly formed (aborted) pillars in forms of hummocks hanging from ceilings, locally also thicker central pillars that originated by merging of smaller fluid-flow channels. The modelling showed that selective lithification theory can explain most of the geomorphological aspects related to the speleogenesis in tepuis.

Additive colours approach for dental ceramics translucency characteristics made from Sumatra and Java natural sands

NASA Astrophysics Data System (ADS)

Takarini, V.; Gunawan, J.; Hasratiningsih, Z.; Rudyawan, A.

2018-04-01

Translucency is one of dental ceramics desirable aesthetic characteristics, which can be used as an indirect restoration. Dental ceramics can also be made using Computed Aided Design/Computer Aided Manufacturing (CAD/CAM) unit that can create variety blocks as an ingot into a customized restoration. This paper presents the results of self-synthesized porcelain blocks generated from natural sand of Sumatera and Java Islands to promote national independency. This research aims to determine the translucency of dental ceramics made from Indonesia’s natural sand. Six samples each of two different synthesized temperatures, 1150 °C and 1200 °C, were made. To analyse translucency of the sample, their image was taken in bright light background in a black box, then additive green and blue colours histogram channel with range 0 (opaque) to 255 (transparent) were evaluated using Matlab R2015B. The result revealed that mean of green peaks on 1150 °C has an average translucency value of 41%, compared to 34% of blue peaks. Lower percentage of translucency, 31% and 25% on the green and blue channel respectively were attained in samples synthesized in 1200 °C. These suggest that 1150 °C is the optimum temperature for translucency for these ceramic samples from natural sands as they contain leucite crystals shown by the XRD analyses as a result of silica-undersaturated mixture indicated by the Electron Dispersive Spectroscopy. SEM (Scanning Electron Microscope) results show remnant of air pocket in the samples sintered at higher temperature.In conclusion, natural sand from Sumatera and Java can be considered as reliable, cheap basic material options in developing self-synthesized dental ceramics with a desirable translucency. These preliminary results indicate that better balance between strength and translucency could potentially be achieved by making nano-sized dental ceramics.

An Experimental Investigation Into the Colonization of Concealed Cadavers by Necrophagous Blowflies

PubMed Central

Charabidze, D.; Hedouin, V.; Gosset, D.

2015-01-01

We used seven baited boxes with different combinations of access holes and odor diffusion surfaces to study the arrival of necrophagous flies. During laboratory experiments, 30 gravid Lucilia sericata females were kept in a chamber with one of the boxes. The box with the largest odor diffusion surface (99 cm2) combined with the lowest accessibility (one 1 cm2 entrance hole) was entered least (5 ± 3.7 flies per run). In contrast, the most frequently entered box (one 9 cm2 entrance hole with no additional odor diffusion surface) caught a mean of 24.6 ± 3.4 flies per run. These results indicate that 1) L. sericata entered nearly inaccessible places and 2) both odor diffusion and accessibility impacted the number of flies caught. During field experiments, the seven boxes were placed together outdoors. The box with the most entrances (ten 9-cm2 holes) caught the most flies (55.6–99.4% of the total). Only a few flies entered the other boxes. Access to the less accessible boxes (poor odor diffusion and small entrances) was also delayed. The major conclusions of the field experiments are that 1) boxes with low accessibility took longer to be accessed; 2) larger odor diffusion surfaces were more attractive to flies; and 3) flies accessed boxes more readily through larger holes than through an equivalent surface area made up of smaller holes. With these conclusions in mind, attempts to quantify the preappearance interval or to interpret the number of flies observed in indoor forensic entomology cases should be approached with caution. PMID:26496788

Moisture Effects on the High Strain-Rate Behavior of Sand (Preprint)

DTIC Science & Technology

2008-04-01

1986) used a conventional SHPB to evaluate a single short pressure pulse traveling through long specimens of 20/40 dry sand, 50/80 dry sand...constant strain-rate within the specimen. In a conventional SHPB experiment, e.g., on dry sand by Veyera (1994), the incident pulse is nearly...strain-rate of 400 s-1. The sand specimen confined in a hardened steel tube, had a dry density of 1.50 g/cm3 with moisture contents varied from 3% to 20

Analysis of wind-blown sand movement over transverse dunes.

PubMed

Jiang, Hong; Huang, Ning; Zhu, Yuanjian

2014-12-01

Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand particle saltation. In this paper, we propose a numerical model for the coupling effect between wind flow and saltating sand particles to simulate wind-blown sand movement over the slope surface and use the SIMPLE algorithm to calculate wind flow and simulate sands transport by tracking sand particle trajectories. We furthermore compare the result of numerical simulation with wind tunnel experiments. These results prove that sand particles have obvious effect on wind flow, especially that over the leeward slope. This study is a preliminary study on windblown sand movement in a complex terrain, and is of significance in the control of dust storms and land desertification.

Analysis of Wind-blown Sand Movement over Transverse Dunes

PubMed Central

Jiang, Hong; Huang, Ning; Zhu, Yuanjian

2014-01-01

Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand particle saltation. In this paper, we propose a numerical model for the coupling effect between wind flow and saltating sand particles to simulate wind-blown sand movement over the slope surface and use the SIMPLE algorithm to calculate wind flow and simulate sands transport by tracking sand particle trajectories. We furthermore compare the result of numerical simulation with wind tunnel experiments. These results prove that sand particles have obvious effect on wind flow, especially that over the leeward slope. This study is a preliminary study on windblown sand movement in a complex terrain, and is of significance in the control of dust storms and land desertification. PMID:25434372

Direct geoelectrical evidence of mass transfer at the laboratory scale

NASA Astrophysics Data System (ADS)

Swanson, Ryan D.; Singha, Kamini; Day-Lewis, Frederick D.; Binley, Andrew; Keating, Kristina; Haggerty, Roy

2012-10-01

Previous field-scale experimental data and numerical modeling suggest that the dual-domain mass transfer (DDMT) of electrolytic tracers has an observable geoelectrical signature. Here we present controlled laboratory experiments confirming the electrical signature of DDMT and demonstrate the use of time-lapse electrical measurements in conjunction with concentration measurements to estimate the parameters controlling DDMT, i.e., the mobile and immobile porosity and rate at which solute exchanges between mobile and immobile domains. We conducted column tracer tests on unconsolidated quartz sand and a material with a high secondary porosity: the zeolite clinoptilolite. During NaCl tracer tests we collected nearly colocated bulk direct-current electrical conductivity (σb) and fluid conductivity (σf) measurements. Our results for the zeolite show (1) extensive tailing and (2) a hysteretic relation between σf and σb, thus providing evidence of mass transfer not observed within the quartz sand. To identify best-fit parameters and evaluate parameter sensitivity, we performed over 2700 simulations of σf, varying the immobile and mobile domain and mass transfer rate. We emphasized the fit to late-time tailing by minimizing the Box-Cox power transformed root-mean square error between the observed and simulated σf. Low-field proton nuclear magnetic resonance (NMR) measurements provide an independent quantification of the volumes of the mobile and immobile domains. The best-fit parameters based on σf match the NMR measurements of the immobile and mobile domain porosities and provide the first direct electrical evidence for DDMT. Our results underscore the potential of using electrical measurements for DDMT parameter inference.

Direct geoelectrical evidence of mass transfer at the laboratory scale

USGS Publications Warehouse

Swanson, Ryan D.; Singha, Kamini; Day-Lewis, Frederick D.; Binley, Andrew; Keating, Kristina; Haggerty, Roy

2012-01-01

Previous field-scale experimental data and numerical modeling suggest that the dual-domain mass transfer (DDMT) of electrolytic tracers has an observable geoelectrical signature. Here we present controlled laboratory experiments confirming the electrical signature of DDMT and demonstrate the use of time-lapse electrical measurements in conjunction with concentration measurements to estimate the parameters controlling DDMT, i.e., the mobile and immobile porosity and rate at which solute exchanges between mobile and immobile domains. We conducted column tracer tests on unconsolidated quartz sand and a material with a high secondary porosity: the zeolite clinoptilolite. During NaCl tracer tests we collected nearly colocated bulk direct-current electrical conductivity (σb) and fluid conductivity (σf) measurements. Our results for the zeolite show (1) extensive tailing and (2) a hysteretic relation between σf and σb, thus providing evidence of mass transfer not observed within the quartz sand. To identify best-fit parameters and evaluate parameter sensitivity, we performed over 2700 simulations of σf, varying the immobile and mobile domain and mass transfer rate. We emphasized the fit to late-time tailing by minimizing the Box-Cox power transformed root-mean square error between the observed and simulated σf. Low-field proton nuclear magnetic resonance (NMR) measurements provide an independent quantification of the volumes of the mobile and immobile domains. The best-fit parameters based on σf match the NMR measurements of the immobile and mobile domain porosities and provide the first direct electrical evidence for DDMT. Our results underscore the potential of using electrical measurements for DDMT parameter inference.

Mice housed on coal dust-contaminated sand: A model to evaluate the impacts of coal mining on health

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

Caballero-Gallardo, Karina, E-mail: kcaballerog@unicartagena.edu.co; Olivero-Verbel, Jesus, E-mail: joliverov@unicartagena.edu.co

Coal dust is the most important air pollutant in coal mining in regards to producing deleterious health effects. It permeates the surrounding environment threatening public health. The aim of this study was to evaluate the toxic effects associated with exposure to sand contaminated with coal dust particles below 38 μm in diameter, obtained from a mineral sample collected in the largest coal mine in South America, La Loma, Cesar, Colombia. Sterilized sand was spiked with coal dust to obtain concentrations ranging from zero to 4% coal dust. To model natural exposure, mice were housed for eight weeks in boxes containingmore » this mixture as bedding after which, they were euthanized and blood and tissue samples were collected. Real time PCR analysis revealed an increase in Cyp1A1 mRNA for living on sand with coal dust concentrations greater than 2% compared to mice living on sand without coal dust. Unexpectedly, for mice on coal dust-polluted sand, Sod1, Scd1 and Nqo1 hepatic mRNA were downregulated. The Comet assay in peripheral blood cells and the micronucleus test in blood smears, showed a significant potential genotoxic effect only at the highest coal dust concentration. Histopathological analysis revealed vascular congestion and peribronchial inflammation in the lungs. A dose–response relationship for the presence of hepatic steatosis, vacuolization and nuclei enlargements was observed in the exposed animals. The data suggest living on a soil polluted with coal dust induces molecular, cellular and histopathological changes in mice. Accordingly, the proposed model can be used to identify deleterious effects of exposure to coal dust deposited in soils that may pose health risks for surrounding wildlife populations. - Highlights: • Mice were exposed to coal dust-contaminated sand. • mRNA Markers for PAH exposure, lipid metabolism and oxidative stress increased. • ALT activity in plasma increased at the highest exposure to coal dust. • Liver tissues of exposed mice showed steatosis and inflammation. • Coal dust exposure produced changes in several blood components.« less

Silica dust exposures during selected construction activities.

PubMed

Flanagan, Mary Ellen; Seixas, Noah; Majar, Maria; Camp, Janice; Morgan, Michael

2003-01-01

This study characterized exposure for dust-producing construction tasks. Eight common construction tasks were evaluated for quartz and respirable dust exposure by collecting 113 personal task period samples for cleanup; demolition with handheld tools; concrete cutting; concrete mixing; tuck-point grinding; surface grinding; sacking and patching concrete; and concrete floor sanding using both time-integrating filter samples and direct-reading respirable dust monitors. The geometric mean quartz concentration was 0.10 mg/m(3) (geometric standard deviation [GSD]=4.88) for all run time samples, with 71% exceeding the threshold limit value. Activities with the highest exposures were surface grinding, tuck-point grinding, and concrete demolition (GM[GSD] of 0.63[4.12], 0.22[1.94], and 0.10[2.60], respectively). Factors recorded each minute were task, tool, work area, respiratory protection and controls used, estimated cross draft, and whether anyone nearby was making dust. Factors important to exposure included tool used, work area configuration, controls employed, cross draft, and in some cases nearby dust. More protective respirators were employed as quartz concentration increased, although respiratory protection was found to be inadequate for 42% of exposures. Controls were employed for only 12% of samples. Exposures were reduced with three controls: box fan for surface grinding and floor sanding, and vacuum/shroud for surface grinding, with reductions of 57, 50, and 71%, respectively. Exposures were higher for sweeping compound, box fan for cleanup, ducted fan dilution, and wetted substrate. Construction masons and laborers are frequently overexposed to silica. The usual protection method, respirators, was not always adequate, and engineering control use was infrequent and often ineffective.

Simultaneous attenuation of pharmaceuticals, organic matter, and nutrients in wastewater effluent through managed aquifer recharge: Batch and column studies.

PubMed

Im, Huncheol; Yeo, Inseol; Maeng, Sung Kyu; Park, Chul Hwi; Choi, Heechul

2016-01-01

Batch and column experiments were conducted to evaluate the removal of organic matter, nutrients, and pharmaceuticals and to identify the removal mechanisms of the target contaminants. The sands used in the experiments were obtained from the Youngsan River located in South Korea. Neutral and cationic pharmaceuticals (iopromide, estrone, and trimethoprim) were removed with efficiencies greater than 80% from different sand media during experiments, due to the effect of sorption between sand and pharmaceuticals. However, the anionic pharmaceuticals (sulfamethoxazole, ketoprofen, ibuprofen, and diclofenac) were more effectively removed by natural sand, compared to baked sand. These observations were mainly attributed to biodegradation under natural conditions of surface organic matter and ATP concentrations. The removal of organic matter and nitrogen was also found to increase under biotic conditions. Therefore, it is indicated that biodegradation plays an important role and act as major mechanisms for the removal of organic matter, nutrients, and selected pharmaceuticals during sand passage and the managed aquifer recharge, which is an effective treatment method for removing target contaminants. However, the low removal efficiencies of pharmaceuticals (e.g., carbamazepine and sulfamethoxazole) require additional processes (e.g., AOPs, NF and RO membrane), a long residence time, and long travel distance for increasing the removal efficiencies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Wastewater use in agriculture: irrigation of sugar cane with effluents from the Cañaveralejo wastewater treatment plant in Cali, Colombia.

PubMed

Madera, C A; Silva, J; Mara, D D; Torres, P

2009-09-01

In Valle del Cauca, south-west Colombia, surface and ground waters are used for sugar cane irrigation at a rate of 100 m3 of water per tonne of sugar produced. In addition large quantities of artificial fertilizers and pesticides are used to grow the crop. Preliminary experiments were undertaken to determine the feasibility of using effluents from the Cañaveralejo primary wastewater treatment plant in Cali. Sugar cane variety CC 8592 was planted in 18 box plots, each 0.5 m2. Six were irrigated with conventional primary effluent, six with chemically enhanced primary effluent and six with groundwater. For each set of six box plots, three contained local soil and three a 50:50 mixture of sand and rice husks. The three irrigation waters were monitored for 12 months, and immediately after harvest the sugar content of the sugar cane juice determined. All physico-chemical quality parameters for the three irrigation waters were lower than the FAO guideline values for irrigation water quality; on the basis of their sodium absorption ratios and electrical conductivity values, both wastewater effluents were in the USDA low-to-medium risk category C2S1. There was no difference in the sugar content of the cane juice irrigated with the three waters. However, the microbiological quality (E. coli and helminth numbers) of the two effluents did not meet the WHO guidelines and therefore additional human exposure control measures are required in order to minimize any resulting adverse health risks to those working in the wastewater-irrigated fields.

Batch experiments characterizing the reduction of chromium(VI) using suboxic material from a mildly reducing sand and gravel aquifer

USGS Publications Warehouse

Anderson, Linda Davis; Kent, Douglas B.; Davis, James A.

1994-01-01

Batch experiments were conducted with sand collected from a shallow sand and gravel aquifer to identify the principal chemical reactions influencing the reduction of Cr(VI), so that field-observed Cr(V1) reduction could be described. The reduction appeared to be heterogeneous and occurred primarily on Fe(I1)-bearing minerals. At only 1 wt % , the fine fraction (<64 μm diameter) of the sediments dominated the amount of aqueous Cr(V1) reduction because of its greater reactivity and surface area. Although reduction of Cr(V1) increased with decreasing pH, small variations in the abundance of fine fraction among the replicate samples obscured pH trends in the batch experiments. Consistent results could only be obtained by separating the fine material from the sand and running parallel experiments on each fraction. As pH decreased (6.4 to 4.5), Cr(V1) reduction increased from 30 to 50 nmol/m2 for the sand fraction (64-1000 μm) and from 130 to 200 nmol/m2 for the fine fraction. The amount of Cr(V1) reduced in both the sand-sized and fine material increased from 35 to 80 and from 130 to 1000 nmol/m2, respectively, for a 10-fold increase in Cr(VI)initial. A consistent description of the rate data was achieved by assuming that intraparticle diffusion limited the observed rate of reduction.

Effect of reference frames and number of cues available on the spatial orientation of males and females in a virtual memory task.

PubMed

Cánovas, Rosa; García, Rubén Fernández; Cimadevilla, Jose Manuel

2011-01-01

The aim of this study was to examine the influence of the number of cues and cue location in human spatial learning. To assess their importance, subjects performed variants of a virtual task called "The Boxes Room". Participants were trained to locate, in a computer-generated environment with 16 boxes, the rewarded boxes through 8 trials. In experiment I, the number of distal cues available was zero, one, two or the standard arrangement (seven cues). In experiment II, place navigation was compared based on distal landmarks (extra-maze cues placed on the walls) and proximal landmarks (proximal cues placed between the boxes). The results of experiment I demonstrated that one cue in the room is enough to obtain a good performance in the task. Experiment II showed that groups using proximal cues were slower and less accurate than groups using distal cues. In addition, our data suggest that men are better navigators than women, as they found the rewarded boxes sooner and committed fewer errors in both studies. These results indicate that performance can change depending on the number and location of available cues. Copyright © 2010 Elsevier B.V. All rights reserved.

Stress and Temperature Distributions of Individual Particles in a Shock Wave Propagating through Dry and Wet Sand Mixtures

NASA Astrophysics Data System (ADS)

Schumaker, Merit; Stewart, Sarah T.; Borg, John P.

2015-06-01

Determining stress and temperature distributions of dynamically compacted particles is of interest to the geophysical and astrological research communities. However, these particle interactions during a shock event are not easily observed in planar shock experiments; it is with the utilization of mesoscale simulations that these granular particle interactions can be unraveled. Unlike homogenous materials, the overall averaged hugoniot state for heterogeneous granular materials differs from the individual stress and temperature states of particles during a shock event. From planar shock experiments on dry and wet sand mixtures, simulations were constructed using CTH. A baseline dry sand simulation was also setup to be compared to sand grains that possessed water particles between grains. It is from these simulations that the distributions of stress and temperatures for individual sand and water particles are presented and compared in this document.

Examination of a Junction-Box Adhesion Test for Use in Photovoltaic Module Qualification: Preprint

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

Miller, D. C.; Wohlgemuth, J. H.

2012-08-01

Engineering robust adhesion of the junction-box (j-box) is a hurdle typically encountered by photovoltaic (PV) module manufacturers during product development. There are historical incidences of adverse effects (e.g., fires) caused when the j-box/adhesive/module system has failed in the field. The addition of a weight to the j-box during the 'damp heat' IEC qualification test is proposed to verify the basic robustness of its adhesion system. The details of the proposed test will be described, in addition to the preliminary results obtained using representative materials and components. The described discovery experiments examine moisture-cured silicone, foam tape, and hot-melt adhesives used inmore » conjunction with PET or glass module 'substrates.' To be able to interpret the results, a set of material-level characterizations was performed, including thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. PV j-boxes were adhered to a substrate, loaded with a prescribed weight, and then placed inside an environmental chamber (at 85C, 85% relative humidity). Some systems did not remain attached through the discovery experiments. Observed failure modes include delamination (at the j-box/adhesive or adhesive/substrate interface) and phase change/creep. The results are discussed in the context of the application requirements, in addition to the plan for the formal experiment supporting the proposed modification to the qualification test.« less

Transport and retention of bacteria and viruses in biochar-amended sand.

PubMed

Sasidharan, Salini; Torkzaban, Saeed; Bradford, Scott A; Kookana, Rai; Page, Declan; Cook, Peter G

2016-04-01

The transport and retention of Escherichia coli and bacteriophages (PRD1, MS2 and ФX174), as surrogates for human pathogenic bacteria and viruses, respectively, were studied in the sand that was amended with several types of biochar produced from various feedstocks. Batch and column studies were conducted to distinguish between the role of attachment and straining in microbe retention during transport. Batch experiments conducted at various solution chemistries showed negligible attachment of viruses and bacteria to biochar before or after chemical activation. At any given solution ionic strength, the attachment of viruses to sand was significantly higher than that of biochar, whereas bacteria showed no attachment to either sand or biochar. Consistent with batch results, biochar addition (10% w/w) to sand reduced virus retention in the column experiments, suggesting a potential negative impact of biochar application to soil on virus removal. In contrast, the retention of bacteria was enhanced in biochar-amended sand columns. However, elimination of the fine fraction (<60μm) of biochar particles in biochar-amended sand columns significantly reduced bacteria retention. Results from batch and column experiments suggest that land application of biochar may only play a role in microbe retention via straining, by alteration of pore size distribution, and not via attachment. Consequently, the particle size distribution of biochar and sediments is a more important factor than type of biochar in determining whether land application of biochar enhances or diminishes microbial retention. Copyright © 2016 Elsevier B.V. All rights reserved.

Granular Crater Formation

NASA Astrophysics Data System (ADS)

Clark, Abe; Behringer, Robert; Brandenburg, John

2009-11-01

This project characterizes crater formation in a granular material by a jet of gas impinging on a granular material, such as a retro-rocket landing on the moon. We have constructed a 2D model of a planetary surface, which consists of a thin, clear box partially filled with granular materials (sand, lunar and Mars simulants...). A metal pipe connected to a tank of nitrogen gas via a solenoid valve is inserted into the top of the box to model the rocket. The results are recorded using high-speed video. We process these images and videos in order to test existing models and develop new ones for describing crater formation. A similar set-up has been used by Metzger et al.footnotetextP. T. Metzger et al. Journal of Aerospace Engineering (2009) We find that the long-time shape of the crater is consistent with a predicted catenary shape (Brandenburg). The depth and width of the crater both evolve logarithmically in time, suggesting an analogy to a description in terms of an activated process: dD/dt = A (-aD) (D is the crater depth, a and A constants). This model provides a useful context to understand the role of the jet speed, as characterized by the pressure used to drive the flow. The box width also plays an important role in setting the width of the crater.

Operational improvements of long-term predicted ephemerides of the Tracking and Data Relay Satellites (TDRSs)

NASA Technical Reports Server (NTRS)

Kostoff, J. L.; Ward, D. T.; Cuevas, O. O.; Beckman, R. M.

1995-01-01

Tracking and Data Relay Satellite (TDRS) orbit determination and prediction are supported by the Flight Dynamics Facility (FDF) of the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD). TDRS System (TDRSS)-user satellites require predicted TDRS ephemerides that are up to 10 weeks in length. Previously, long-term ephemerides generated by the FDF included predictions from the White Sands Complex (WSC), which plans and executes TDRS maneuvers. TDRSs typically have monthly stationkeeping maneuvers, and predicted postmaneuver state vectors are received from WSC up to a month in advance. This paper presents the results of an analysis performed in the FDF to investigate more accurate and economical long-term ephemerides for the TDRSs. As a result of this analysis, two new methods for generating long-term TDRS ephemeris predictions have been implemented by the FDF. The Center-of-Box (COB) method models a TDRS as fixed at the center of its stationkeeping box. Using this method, long-term ephemeris updates are made semiannually instead of weekly. The impulse method is used to model more maneuvers. The impulse method yields better short-term accuracy than the COB method, especially for larger stationkeeping boxes. The accuracy of the impulse method depends primarily on the accuracy of maneuver date forecasting.

Power Scaling of the Mainland Shoreline of the Atlantic Coast of the United States

NASA Astrophysics Data System (ADS)

Vasko, E.; Barton, C. C.; Geise, G. R.; Rizki, M. M.

2017-12-01

The fractal dimension of the mainland shoreline of the Atlantic coast of the United Stated from Maine to Homestead, FL has been measured in 1000 km increments using the box-counting method. The shoreline analyzed is the NOAA Medium Resolution Shoreline (https://shoreline.noaa.gov/data/datasheets/medres.html). The shoreline was reconstituted into sequentially numbered X-Y coordinate points in UTM Zone 18N which are spaced 50 meters apart, as measured continuously along the shoreline. We created a MATLAB computer code to measure the fractal dimension by box counting while "walking" along the shoreline. The range of box sizes is 0.7 to 450 km. The fractal dimension ranges from 1.0 to1.5 along the mainland shoreline of the Atlantic coast. The fractal dimension is compared with beach particle sizes (bedrock outcrop, cobbles, pebbles, sand, clay), tidal range, rate of sea level rise, rate and direction of vertical crustal movement, and wave energy, looking for correlation with the measured fractal dimensions. The results show a correlation between high fractal dimensions (1.3 - 1.4) and tectonically emergent coasts, and low fractal dimensions (1.0 - 1.2) along submergent and stable coastal regions. Fractal dimension averages 1.3 along shorelines with shoreline protection structures such as seawalls, jetties, and groins.

The growth-defense trade-off and habitat specialization by plants in Amazonian forests.

PubMed

Fine, Paul V A; Miller, Zachariah J; Mesones, Italo; Irazuzta, Sebastian; Appel, Heidi M; Stevens, M Henry H; Sääksjärvi, Ilari; Schultz, Jack C; Coley, Phyllis D

2006-07-01

Tropical forests include a diversity of habitats, which has led to specialization in plants. Near Iquitos, in the Peruvian Amazon, nutrient-rich clay forests surround nutrient-poor white-sand forests, each harboring a unique composition of habitat specialist trees. We tested the hypothesis that the combination of impoverished soils and herbivory creates strong natural selection for plant defenses in white-sand forest, while rapid growth is favored in clay forests. Recently, we reported evidence from a reciprocal-transplant experiment that manipulated the presence of herbivores and involved 20 species from six genera, including phylogenetically independent pairs of closely related white-sand and clay specialists. When protected from herbivores, clay specialists exhibited faster growth rates than white-sand specialists in both habitats. But, when unprotected, white-sand specialists outperformed clay specialists in white-sand habitat, and clay specialists outperformed white-sand specialists in clay habitat. Here we test further the hypothesis that the growth defense trade-off contributes to habitat specialization by comparing patterns of growth, herbivory, and defensive traits in these same six genera of white-sand and clay specialists. While the probability of herbivore attack did not differ between the two habitats, an artificial defoliation experiment showed that the impact of herbivory on plant mortality was significantly greater in white-sand forests. We quantified the amount of terpenes, phenolics, leaf toughness, and available foliar protein for the plants in the experiment. Different genera invested in different defensive strategies, and we found strong evidence for phylogenetic constraint in defense type. Overall, however, we found significantly higher total defense investment for white-sand specialists, relative to their clay specialist congeners. Furthermore, herbivore resistance consistently exhibited a significant trade-off against growth rate in each of the six phylogenetically independent species-pairs. These results confirm theoretical predictions that a trade-off exists between growth rate and defense investment, causing white-sand and clay specialists to evolve divergent strategies. We propose that the growth-defense trade-off is universal and provides an important mechanism by which herbivores govern plant distribution patterns across resource gradients.

Provenance of sand on the Poverty Bay shelf, the link between source and sink sectors of the Waipaoa River sedimentary system

NASA Astrophysics Data System (ADS)

Parra, Julie G.; Marsaglia, Kathleen M.; Rivera, Kevin S.; Dawson, Shelby T.; Walsh, J. P.

2012-12-01

The Poverty Shelf, North Island, New Zealand, is a segment of the Waipaoa Sedimentary System (WSS), a MARGINS Source-to-Sink focus site. Our petrographic analysis of sand from shelf core samples indicates that the sand fraction is mainly derived from intra- and potentially extrabasinal sources, but surprisingly, the major fluvial system that drains into Poverty Bay, the Waipaoa River (mean %QFL = xQyFzL), is not the dominant source. Only one vibracore at the mouth of Poverty Bay contained sand (%QFL = xQyFzL) potentially derived from the Waipaoa River. The shelf sand (mean %QFL = xQyFzL) more strongly resembles beach sand (mean %QFL = xQyFzL) collected along the coast, which is likely sourced from pervasive local cliff erosion of Miocene-Pliocene sedimentary units that exhibit similar sandstone detrital modes (mean %QFL = xQyFzL). Texturally, coarser, more poorly sorted and more angular sand is located along the outer shelf, while finer, well-sorted sand characterizes the mid-shelf. These findings suggest a shorter transport history for the material near the outer-shelf bathymetric high areas, and this observation along with the composition data suggests that they were sourced by erosion of locally exposed Miocene-Pliocene units. A potential extrabasinal source of shelf sediment is indicated by anomalous prolate and equant-shaped greywacke (Torlesse) and minor red chert pebbles collected in two outer-shelf box cores on the Lachlan anticline; these are not lithologies found within the terrestrial segment of the WSS or strata comprising the outer-shelf highs. The clast shapes are also distinctly different from the oblate-shaped, pebble-sized greywacke gravel clasts on beaches in Hawke Bay. Rather, these sediments are more similar to Torlesse stream gravel. Seismic and multibeam data support the possibility that during the most recent sea-level lowstand, the Hawke Bay fluvial system flowed into Poverty Canyon, bringing these unique gravels onto what is now the Poverty outer shelf. The presence of the Torlesse gravel is significant in that it highlights how the WSS was not a closed sedimentary system in the past, just as recent sedimentary research has shown in the case today.

Combined effects of astragalus soup and persistent Taiji boxing on improving the immunity of elderly women.

PubMed

Song, Qing-Hua; Xu, Rong-Mei; Zhang, Quan-Hai; Shen, Guo-Qing; Ma, Ming; Zhao, Xin-Ping; Guo, Yan-Hua; Wang, Yi

2014-01-01

To observe the combined effects of astragalus soup and persistent Taiji boxing on improving the immunity of women of advanced years. 120 elderly women lacking daily exercise were chosen as the study subjects. By using the table of random numbers, they were then divided into the control group and the experiment group, consisting of 60 each. The control group practiced Taiji boxing for 45 minutes twice a day. The experiment group did the same, and, in addition, took astragalus soup after each boxing. Indexes related to physical immunity of the two groups were observed and compared when they were first chosen, when the alternative treatment was applied three, six and twelve months later, respectively. The two groups demonstrated no significant differences in general data and research indexes when chosen (P > 0.05). Three months after the two groups were chosen and treated differently, the control group demonstrated no significant improvement while most indexes of the experiment group improved considerably (P > 0.05). After six months, the related indexes of both groups improved substantially (P < 0.05) and the improvement with the experiment was even clearer (P < 0.05). Twelve months later, the improvement with the experiment group was more noticeable (P < 0.01 or P < 0.05). In a relatively short period of three months, Taiji boxing produces no noticeable effect on the improvement of immunity in elderly women. However, when they resume the exercise for another three months and longer, Taiji boxing has a noticeable advantage and the effect is the most favorable when it is combined with astragalus soup.

Box Plots in the Australian Curriculum

ERIC Educational Resources Information Center

Watson, Jane M.

2012-01-01

This article compares the definition of "box plot" as used in the "Australian Curriculum: Mathematics" with other definitions used in the education community; describes the difficulties students experience when dealing with box plots; and discusses the elaboration that is necessary to enable teachers to develop the knowledge…

Consumer reaction to call boxes on the Dulles toll road in Virginia

DOT National Transportation Integrated Search

2001-06-01

This study represents the first part of an assessment of consumer reactions to the introduction of call boxes on the Dulles Toll Road (Northern Virginia). It initially looks at the existing experiences with call boxes in the US. Despite their adoptio...

Effect of Binder and Mold parameters on Collapsibility and Surface Finish of Gray Cast Iron No-bake Sand Molds

NASA Astrophysics Data System (ADS)

Srinivasulu Reddy, K.; Venkata Reddy, Vajrala; Mandava, Ravi Kumar

2017-08-01

Chemically bonded no-bake molds and cores have good mechanical properties and produce dimensionally accurate castings compared to green sand molds. Poor collapsibility property of CO2 hardened sodium silicate bonded sand mold and phenolic urethane no-bake (PUN) binder system, made the reclamation of the sands more important. In the present work fine silica sand is mixed with phenolic urethane no-bake binder and the sand sets in a very short time within few minutes. In this paper it is focused on optimizing the process parameters of PUN binder based sand castings for better collapsibility and surface finish of gray cast iron using Taguchi design. The findings were successfully verified through experiments.

Effects of sand burial and wind disturbances on moss soil crusts in a revegetated area of the Tennger Desert, Northern China

NASA Astrophysics Data System (ADS)

Jia, R. L.; Li, X. R.; Liu, L. C.; Gao, Y. H.

2012-04-01

Sand burial and wind are two predominant natural disturbances in the desert ecosystems worldwide. However, the effects of sand burial and wind disturbances on moss soil crusts are still largely unexplored. In this study, two sets of experiments were conducted separately to evaluated the effects of sand burial (sand depth of 0, 1, 2, 3 and 4 mm) and wind blowing (wind speed of 0.2, 3, 6 and 9ms-1) on ecophysiological variables of two moss soil crusts collected from a revegetated area of the Tengger Desert, Northern China. Firstly, the results from the sand burial experiment revealed that respiration rate was significantly decreased and that moss shoot elongation was significantly increased after burial. In addition, Bryum argenteum crust showed the fastest speed of emergence and highest tolerance index, followed by Didymodon vinealis crust. This sequence was consistent with the successional order of the two moss crusts that happened in our study area, indicating that differential sand burial tolerance explains their succession sequence. Secondly, the results from the wind experiment showed that CO2 exchange, PSII photochemical efficiency, photosynthetic pigments, shoot upgrowth, productivity and regeneration potential of the two moss soil crust mentioned above were all substantially depressed. Furthermore, D. vinealis crust exhibited stronger wind resistance than B. argenteum crust from all aspects mentioned above. And this is comparison was identical with their contrasting microhabitats with B. argenteum crust being excluded from higher wind speed microsites in the windward slopes, suggesting that the differential wind resistance of moss soil crusts explains their microdistribution pattern. In conclusion, the ecogeomorphological processes of moss soil crusts in desert ecosystems can be largely determined by natural disturbances caused by sand burial and wind blowing in desert ecosystems.

A continuously weighing, high frequency sand trap: Wind tunnel and field evaluations

NASA Astrophysics Data System (ADS)

Yang, Fan; Yang, XingHua; Huo, Wen; Ali, Mamtimin; Zheng, XinQian; Zhou, ChengLong; He, Qing

2017-09-01

A new continuously weighing, high frequency sand trap (CWHF) has been designed. Its sampling efficiency is evaluated in a wind tunnel and the potential of the new trap has been demonstrated in field trials. The newly designed sand trap allows fully automated and high frequency measurement of sediment fluxes over extensive periods. We show that it can capture the variations and structures of wind-driven sand transport processes and horizontal sediment flux, and reveal the relationships between sand transport and meteorological parameters. Its maximum sampling frequency can reach 10 Hz. Wind tunnel tests indicated that the sampling efficiency of the CWHF sand trap varies between 39.2 to 64.3%, with an average of 52.5%. It achieved a maximum sampling efficiency of 64.3% at a wind speed of 10 m s- 1. This is largely achieved by the inclusion of a vent hole which leads to a higher sampling efficiency than that of a step-like sand trap at high wind speeds. In field experiments, we show a good agreement between the mass of sediment from the CWHF sand trap, the wind speed at 2 m and the number of saltating particles at 5 cm above the ground surface. According to analysis of the horizontal sediment flux at four heights from the CWHF sand trap (25, 35, 50, and 100 cm), the vertical distribution of the horizontal sediment flux up to a height of 100 cm above the sand surface follows an exponential function. Our field experiments show that the new instrument can capture more detailed information on sediment transport with much reduced labor requirement. Therefore, it has great potential for application in wind-blown sand monitoring and process studies.

Hydraulic experiment on tsunami sand deposits relating with grain size distribution and magnitude of incident waves

NASA Astrophysics Data System (ADS)

Yamamoto, A.; Takahashi, T.; Harada, K.; Nojima, K.

2016-12-01

A huge earthquake occurred off the Tohoku district in Japan on March 11th, 2011. A massive tsunami generated by the earthquake attacked coastal areas and caused serious damage. The tsunami disaster requires to reconsider tsunami measures in the Nankai Trough. Many of the measures are based on histories of large earthquakes and tsunamis. Because they are low frequency disasters and their historical documents are limited, tsunami sand deposits have been expected to analyze paleotsunamis. Tsunami sand deposits, however, are only used to confirm the fact of tsunamis and to determine the relative magnitudes. The thickness of sand layer and the grain size may be clues to estimate the tsunami force. Further, it could reveal the tsunami source. These results are also useful to improve the present tsunami measures. The objective of this study is to investigate the formation mechanism of tsunami sand deposits by hydraulic experiment. A two-dimensional water channel consisted of a wave maker, a flat section and a slope section. A movable bed section with various grain sizes and distribution of sand was set at the end of flat section. Bore waves of several heights transported the sand to the slope section by run-up. Water surface elevation and velocity were measured at several points. Tsunami sand deposit distribution was also measured along the slope section. The experimental result showed that the amount of tsunami sand deposit was relating with the grain size distribution and the magnitude of incident waves. Further, the number of incident waves affected the profile of tsunami sand deposits.

Using Multimedia Metadata to Improve Network Efficiency

DTIC Science & Technology

2012-09-01

the north-aligned bounding box. When compared using all angular variations for the direction-of-travel-aligned 3:4 aspect ratio bounding box, the...programs that run the experiment are written in Java . The experiment consists of two distinct programs that communicate via Java sockets (TCP). 1

Volunteers build Bay St. Louis playground

NASA Image and Video Library

2005-12-17

More than 650 volunteers - many of them employees at NASA's Stennis Space Center - weathered rain and cold to transform Bay St. Louis' old City Park into a playground Dec. 17. Volunteers assembled and erected a slide, swing set, jungle gym, sand box and planter benches in an eight-hour time frame. The playground was the first new structure built in the town devastated by Hurricane Katrina and the first on the Gulf Coast after the storm. The project was financed and led by nonprofit organization KaBOOM!, whose vision is to create a great place to play within walking distance of every child in America.

Volunteers build Bay St. Louis playground

NASA Technical Reports Server (NTRS)

2005-01-01

More than 650 volunteers - many of them employees at NASA's Stennis Space Center - weathered rain and cold to transform Bay St. Louis' old City Park into a playground Dec. 17. Volunteers assembled and erected a slide, swing set, jungle gym, sand box and planter benches in an eight-hour time frame. The playground was the first new structure built in the town devastated by Hurricane Katrina and the first on the Gulf Coast after the storm. The project was financed and led by nonprofit organization KaBOOM!, whose vision is to create a great place to play within walking distance of every child in America.

Modernized Approach for Generating Reproducible Heterogeneity Using Transmitted-Light for Flow Visualization Experiments

NASA Astrophysics Data System (ADS)

Jones, A. A.; Holt, R. M.

2017-12-01

Image capturing in flow experiments has been used for fluid mechanics research since the early 1970s. Interactions of fluid flow between the vadose zone and permanent water table are of great interest because this zone is responsible for all recharge waters, pollutant transport and irrigation efficiency for agriculture. Griffith, et al. (2011) developed an approach where constructed reproducible "geologically realistic" sand configurations are deposited in sandfilled experimental chambers for light-transmitted flow visualization experiments. This method creates reproducible, reverse graded, layered (stratified) thin-slab sand chambers for point source experiments visualizing multiphase flow through porous media. Reverse-graded stratification of sand chambers mimic many naturally occurring sedimentary deposits. Sandfilled chambers use light as nonintrusive tools for measuring water saturation in two-dimensions (2-D). Homogeneous and heterogeneous sand configurations can be produced to visualize the complex physics of the unsaturated zone. The experimental procedure developed by Griffith, et al. (2011) was designed using now outdated and obsolete equipment. We have modernized this approach with new Parker Deadel linear actuator and programed projects/code for multiple configurations. We have also updated the Roper CCD software and image processing software with the latest in industry standards. Modernization of transmitted-light source, robotic equipment, redesigned experimental chambers, and newly developed analytical procedures have greatly reduced time and cost per experiment. We have verified the ability of the new equipment to generate reproducible heterogeneous sand-filled chambers and demonstrated the functionality of the new equipment and procedures by reproducing several gravity-driven fingering experiments conducted by Griffith (2008).

Freestall maintenance: effects on lying behavior of dairy cattle.

PubMed

Drissler, M; Gaworski, M; Tucker, C B; Weary, D M

2005-07-01

In a series of 3 experiments, we documented how sand-bedding depth and distribution changed within freestalls after new bedding was added and the effect of these changes on lying behavior. In experiment 1, we measured changes in bedding depth over a 10-d period at 43 points in 24 freestalls. Change in depth of sand was the greatest the day after new sand was added and decreased over time. Over time, the stall surface became concave, and the deepest part of the stall was at the center. Based on the results of experiment 1, we measured changes in lying behavior when groups of cows had access to freestalls with sand bedding that was 0, 3.5, 5.2, or 6.2 cm at the deepest point, below the curb, while other dimensions remained fixed. We found that daily lying time was 1.15 h shorter in stalls with the lowest levels of bedding compared with stalls filled with bedding. Indeed, for every 1-cm decrease in bedding, cows spent 11 min less time lying down during each 24-h period. In a third experiment, we imposed 4 treatments that reflected the variation in sand depth within stalls: 0, 6.2, 9.9, and 13.7 cm below the curb. Again, lying times reduced with decreasing bedding, such that cows using the stalls with the least amount of bedding (13.7 cm below curb) spent 2.33 h less time per day lying down than when housed with access to freestalls filled with sand (0 cm below curb).

Broadband Scattering from Sand and Sand/Mud Sediments with Extensive Environmental Characterization

DTIC Science & Technology

2017-01-30

experiment , extensive envi- ronmental characterization was also performed to support data/model comparisons for both experimental efforts. The site...mechanisms, potentially addressing questions left unresolved from the previous sediment acoustics experiments , SAX99 and SAX04. This work was also to provide...environmental characterization to support the analysis of data collected during the Target and Reverberation Experiment in 2013 (TREX13) as well as

Movement of tagged dredged sand at thalweg disposal sites in the Upper Mississippi River. Volume 2. Savanna Bay and Duck Creek sites

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

Paddock, R.A.; McCown, D.L.

Experiments were conducted on the Upper Mississippi River at two sites, Savanna Bay and Duck Creek, to investigate the movement of dredged sand after disposal in the thalweg. These experiments are part of a larger study, which includes similar experiments conducted earlier at two other sites on the Upper Mississippi River. At the Savanna Bay site, hydraulically dredged sand was tagged with sand coated with fluorescent dye before being deposited as a pile in the thalweg. Bathymetric surveys and surficial bottom sampling were conducted on five occasions over a nine-month period following disposal to identify changes in the topography ofmore » the pile and to detect the presence of dyed sand. At the Duck Creek site, only bathymetric surveys were conducted. The general behavior of the disposal piles at these two new sites was similar to that of the piles at the first two sites. Topographic evidence of the piles disappeared, and bottom conditions similar to the predisposal conditions were reestablished following the first period of high river flows after disposal. At Savanna Bay, as had happened at the first two sites, the tagged sand remained in the main river channel as it moved downstream in response to flood currents and did not migrate into nearby border areas, backwaters, or sloughs. 6 references, 89 figures, 2 tables.« less

Environmental Sense Box: A Strategy for Helping Elementary School Students Understand Abstract Environments through Concrete Learning Activities.

ERIC Educational Resources Information Center

Sesow, F. Wm.

This paper suggests a technique for the development, collection, and organization of materials that will aid learning through the use of the senses by building an environmental sense box. England is used as an example of a place that provides many sensory experiences which can be duplicated in such a box. The box can be made from a cardboard…

Effects of three types of free-stall surfaces on preferences and stall usage by dairy cows.

PubMed

Tucker, C B; Weary, D M; Fraser, D

2003-02-01

One important criterion in choosing appropriate housing systems for dairy cattle is that the freestall provides a comfortable surface for the cow. This paper describes two experiments testing the effects of commonly used lying surfaces on stall preference and stall usage by Holstein cows. In both experiments, 12 cows were housed individually in separate pens. Each pen contained three free stalls with a different surface: deep-bedded sawdust, deep-bedded sand, and a geotextile mattress covered with 2 to 3 cm of sawdust. The animals were restricted to each surface in turn, in a random order for either 2 (Experiment 1) or 3 d (Experiment 2). Both before and after this restriction phase, the animals were allowed access to all three surfaces, and preference was determined, based on lying times. Of the 12 cows used in Experiment 1, 10 preferred sawdust before and nine after the restriction phase. During the restriction phase, average lying times and number of lying events during the restriction phase were significantly lower for the sand-bedded stalls (P < or = 0.05), and standing times were higher on mattresses (P < or = 0.05), compared with sawdust. Although these cows had some experience with all three surfaces during the experiment, they had been housed in sawdust-bedded stalls during their previous lactation. Cows used in Experiment 2 had spent their previous lactation in sand bedded stalls. In this experiment, about half the cows preferred sand and half sawdust, after the restriction phase. During the restriction phase of experiment, lying times and number of lying events were lower, and standing times were higher when the animals were restricted to the mattresses compared to either sand or sawdust (P < or = 0.05). These results indicate that (1) free stall surface can affect both stall preferences and stall usage, and (2) mattresses are less preferred.

A Simulation of an Energy-Efficient Home.

ERIC Educational Resources Information Center

McLeod, Richard J.; And Others

1981-01-01

A shoe box is converted into a model home to demonstrate the energy efficiency of various insulation measures. Included are instructions for constructing the model home from a shoe box, insulating the shoe box, several activities involving different insulation measures, extensions of the experiment, and post-lab discussion topics. (DS)

Laparoscopic surgical box model training for surgical trainees with no prior laparoscopic experience.

PubMed

Nagendran, Myura; Toon, Clare D; Davidson, Brian R; Gurusamy, Kurinchi Selvan

2014-01-17

Surgical training has traditionally been one of apprenticeship, where the surgical trainee learns to perform surgery under the supervision of a trained surgeon. This is time consuming, costly, and of variable effectiveness. Training using a box model physical simulator - either a video box or a mirrored box - is an option to supplement standard training. However, the impact of this modality on trainees with no prior laparoscopic experience is unknown. To compare the benefits and harms of box model training versus no training, another box model, animal model, or cadaveric model training for surgical trainees with no prior laparoscopic experience. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and Science Citation Index Expanded to May 2013. We included all randomised clinical trials comparing box model trainers versus no training in surgical trainees with no prior laparoscopic experience. We also included trials comparing different methods of box model training. Two authors independently identified trials and collected data. We analysed the data with both the fixed-effect and the random-effects models using Review Manager for analysis. For each outcome, we calculated the standardised mean difference (SMD) with 95% confidence intervals (CI) based on intention-to-treat analysis whenever possible. Twenty-five trials contributed data to the quantitative synthesis in this review. All but one trial were at high risk of bias. Overall, 16 trials (464 participants) provided data for meta-analysis of box training (248 participants) versus no supplementary training (216 participants). All the 16 trials in this comparison used video trainers. Overall, 14 trials (382 participants) provided data for quantitative comparison of different methods of box training. There were no trials comparing box model training versus animal model or cadaveric model training. Box model training versus no training: The meta-analysis showed that the time taken for task completion was significantly shorter in the box trainer group than the control group (8 trials; 249 participants; SMD -0.48 seconds; 95% CI -0.74 to -0.22). Compared with the control group, the box trainer group also had lower error score (3 trials; 69 participants; SMD -0.69; 95% CI -1.21 to -0.17), better accuracy score (3 trials; 73 participants; SMD 0.67; 95% CI 0.18 to 1.17), and better composite performance scores (SMD 0.65; 95% CI 0.42 to 0.88). Three trials reported movement distance but could not be meta-analysed as they were not in a format for meta-analysis. There was significantly lower movement distance in the box model training compared with no training in one trial, and there were no significant differences in the movement distance between the two groups in the other two trials. None of the remaining secondary outcomes such as mortality and morbidity were reported in the trials when animal models were used for assessment of training, error in movements, and trainee satisfaction. Different methods of box training: One trial (36 participants) found significantly shorter time taken to complete the task when box training was performed using a simple cardboard box trainer compared with the standard pelvic trainer (SMD -3.79 seconds; 95% CI -4.92 to -2.65). There was no significant difference in the time taken to complete the task in the remaining three comparisons (reverse alignment versus forward alignment box training; box trainer suturing versus box trainer drills; and single incision versus multiport box model training). There were no significant differences in the error score between the two groups in any of the comparisons (box trainer suturing versus box trainer drills; single incision versus multiport box model training; Z-maze box training versus U-maze box training). The only trial that reported accuracy score found significantly higher accuracy score with Z-maze box training than U-maze box training (1 trial; 16 participants; SMD 1.55; 95% CI 0.39 to 2.71). One trial (36 participants) found significantly higher composite score with simple cardboard box trainer compared with conventional pelvic trainer (SMD 0.87; 95% CI 0.19 to 1.56). Another trial (22 participants) found significantly higher composite score with reverse alignment compared with forward alignment box training (SMD 1.82; 95% CI 0.79 to 2.84). There were no significant differences in the composite score between the intervention and control groups in any of the remaining comparisons. None of the secondary outcomes were adequately reported in the trials. The results of this review are threatened by both risks of systematic errors (bias) and risks of random errors (play of chance). Laparoscopic box model training appears to improve technical skills compared with no training in trainees with no previous laparoscopic experience. The impacts of this decreased time on patients and healthcare funders in terms of improved outcomes or decreased costs are unknown. There appears to be no significant differences in the improvement of technical skills between different methods of box model training. Further well-designed trials of low risk of bias and random errors are necessary. Such trials should assess the impacts of box model training on surgical skills in both the short and long term, as well as clinical outcomes when the trainee becomes competent to operate on patients.

Protection against suspended sand: the function of the branchial membrane in the blue mussel Mytilus edulis

NASA Astrophysics Data System (ADS)

de Vooys, C. G. N.

2006-09-01

Blue mussels ( Mytilus edulis) living in estuaries have to cope with varying concentrations of suspended sand. Sand flowing through the inhalant siphons comes into the infrabranchial chamber. The inhalant siphon can be partially closed by the branchial membrane. As a result the inward flow decreases, and suspended sand sinks and can be eliminated. Experiments with mussels from three ecologically different locations showed about the same response of the branchial membrane on contact with suspended sand. The presence and function of the branchial membrane appears to be an adaptation of mussels to their estuarine environment.

National Metal Casting Research Institute final report. Volume 1, Sand reclamation

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

Vondra, L.F.; Burningham, J.S.

1995-08-01

A mobile thermal foundry sand reclamation unit was designed and constructed. This unit consisted of thermal and mechanical sand reclamation equipment installed on the bed of a 50 foot low-boy trailer. It was transported to a number of Midwest foundries for on-site demonstration of the sand reclamation process. This allowed participating foundries to have their own refuse sand (10-100 tons) processed and then reused in production for evaluation. The purpose for building the unit was to demonstrate to foundries through ``hands on`` experience that refuse sands can be reclaimed and successfully reused particularly in regard to product quality. Most ofmore » the participating foundries indicated a high level of satisfaction with the reclaimed sand. Laboratory testing of samples of the used sand, before and after processing by the demonstration unit, verified the usability of the reclaimed sand. One of the foundries participating was a brass foundry, the sand from this foundry contained lead and is classified as a hazardous material. After reclamation the sand was no longer hazardous and could also be reused in the foundry.« less

Transmission experiment of elastic waves with short wavelengths through a highly porous sand soil during water injection

NASA Astrophysics Data System (ADS)

Nakayama, M.; Kawakata, H.; Hirano, S.; Doi, I.; Takahashi, N.

2016-12-01

Transmitted waves at high frequencies attenuate strongly through highly porous media such as shallow ground, although the waves enable us to investigate physical properties of the media with high-spatial resolutions. Nakayama et al. (2015, AGU) tried to investigate the spatio-temporal variations in physical properties of a highly porous sand soil during water injection in laboratory. Accelerometers installed in the sand soil received only the signals of no higher than 0.5 kHz, although they used rectangular waveforms as input signals. The wavelength corresponding to 0.5 kHz is about 400 mm because the measured wave velocity is about 200 m/s. The wavelength is comparable to the path lengths of the transmitted waves, so that it cannot be discussed how the temporal variations in physical properties depend on the paths. In this study, we try to transmit waves with wavelengths much shorter than a sand soil and path lengths through a highly porous sand soil. We make a sand soil (750 mm long, 300 mm wide, and 300 mm high) with porosity about 40%. We install a shaker as a wave source at a deep part in the sand soil. In addition, we install accelerometers, pore pressure gauges, and electrodes at different depths. We inject tap water into the sand soil from the bottom, and record transmitted waves together with pore pressure and electrode voltage until the sand soil becomes saturated. Note that we adopt sweep signals (0.1-10 kHz) as the source so that the shaker can generate high frequency waves more strongly than rectangular signals. Accelerometers receive the signals at least up to 5 kHz during the experiment (Figure 1). The wavelength corresponding to 5 kHz is about 40 mm. In conclusion, we succeed in detecting transmitted waves propagating through the highly porous sand soil whose path lengths are about ten times their wave lengths. Acknowledgment: We are grateful to Takayoshi Kishida for supporting the experiment. This work is supported by JSPS KAKENHI Grant Numbers JP15H02996 and 26750135.

ArduiPod Box: a low-cost and open-source Skinner box using an iPod Touch and an Arduino microcontroller.

PubMed

Pineño, Oskar

2014-03-01

This article introduces the ArduiPod Box, an open-source device built using two main components (i.e., an iPod Touch and an Arduino microcontroller), developed as a low-cost alternative to the standard operant conditioning chamber, or "Skinner box." Because of its affordability, the ArduiPod Box provides an opportunity for educational institutions with small budgets seeking to set up animal laboratories for research and instructional purposes. A pilot experiment is also presented, which shows that the ArduiPod Box, in spite of its extraordinary simplicity, can be effectively used to study animal learning and behavior.

Grid systems for Earth radiation budget experiment applications

NASA Technical Reports Server (NTRS)

Brooks, D. R.

1981-01-01

Spatial coordinate transformations are developed for several global grid systems of interest to the Earth Radiation Budget Experiment. The grid boxes are defined in terms of a regional identifier and longitude-latitude indexes. The transformations associate longitude with a particular grid box. The reverse transformations identify the center location of a given grid box. Transformations are given to relate the rotating (Earth-based) grid systems to solar position expressed in an inertial (nonrotating) coordinate system. The FORTRAN implementations of the transformations are given, along with sample input and output.

Transfer of chlorfenapyr among workers of Reticulitermes flavipes (Isoptera: Rhinotermitidae) in the laboratory

Treesearch

Thomas G. Shelton; Joseph E. Mulroonery; Terence L. Wagner

2006-01-01

The potential for transfer of chlorfenapyr among subterranean termites was investigated using a donor-recipient (5:95 ratio) experiment. In one experiment, workers of Reticulitermes flavipeS(Kollar) (Isoptera: Rhinotermitidae) were exposed to treated sand at 0,50,100,250, and 500 ppm chlorfenapyr (wt [AI] /wt sand). Exposed workers were allowed to...

How Do Symbols Affect 3- to 4-Year-Olds' Executive Function? Evidence from a Reverse-Contingency Task

ERIC Educational Resources Information Center

Apperly, Ian A.; Carroll, Daniel J.

2009-01-01

In two experiments, 330 3- to 4-year-olds competed for stickers in a game in which the optimal response strategy was to point to an empty box that their opponent would receive in order to obtain a baited box for themselves. When the baited box contained stickers, children showed a strong tendency to point at the baited box and therefore lose the…

Sediments from the Boxing Day tsunami on the coasts of southeastern India and Kenya

NASA Astrophysics Data System (ADS)

Weiss, R.; Bahlburg, H.

2006-12-01

On the Boxing Day 2004, the world community experienced a catastrophic tsunami in the Indian Ocean and could also saw how unprepared and unaware countries along the Indian ocean were. Beyond the tragedy of the tremendous loss of lives, the result of this event is an opportunity to study a global tsunami (mega-tsunami) in many regards. Here, we report on tsunami sediments left behind on beaches at the coast of Tamil Nadu (India) and on beaches between Malindi and Lamu (Kenya). Characteristic debris accumulations on the beach surface at Tamil Nadu (India) showed the impact of three tsunami waves. In this area, the tsunami climbed ~5 m up the beach; the last traces of a tsunami wave were found ~580 m away from the shoreline. Palm trees indicated an overland flow depth of 3.5 m, ~50 m from the shoreline. The tsunami deposits were up to 30 cm thick. They had an erosional base to the underlying soil and pre-tsunami beach deposits and were made up of moderately well- to well-sorted coarse and medium sand. The sand sheet thins inland, but without a decrease in grain size. Three distinct layers could be identified within the tsunami deposit. The lower one occasionally displayed cross-bedding with foresets dipping landward indicating deposition during run-up. The two upper layers were graded or parallel-laminated without indicators of flow directions. The boundaries between the different layers were marked by dark laminae, rich in heavy minerals. Also, the presence of benthic foraminifera indicates entrainment of sediment into the water column by the incoming tsunami wave in water depths less than 30 m. On beaches between Malindi and Lamu, Kenya, the traces of only one tsunami wave could be found, which attained a run-up height of about 3 m and traveled ~35 m inland with respect to the tidal stage at tsunami impact. The tsunami sediments consist of one layer of fine sand and are predominantly composed of heavy minerals supplied to the sea by nearby rivers. A slight fining-inland trend could be identified in the thinning- inland sand layer. Benthic foraminifera also indicate an entrainment of sediment by the incoming tsunami wave in a water depth less than 30 m, however there are indications that sediment might be entrained in a water depth of 80 m. The fact that only one sand layer occurs in Kenya as opposed to three at Tamil Nadu might lead to the conclusion that only one wave approached the Kenyan coast. This interpretation is misleading because the Kenyan coast is several thousand kilometers away from source area of the tsunami; the non-linear behavior of the incoming tsunami waves, especially the interaction with the nearby reef, may have resulted in the discovered sedimentologic evidence of the tsunami impact on the Kenyan coast.

Examining the Displacement of Energy during Formation of Shear Bands

NASA Astrophysics Data System (ADS)

Hernandez, M.; Hilley, G. E.

2011-12-01

M.X. Hernandez, G. Hilley Department of Geological and Environmental Sciences, Stanford University, Stanford, CA This study has originated from an experimental (sandbox) setting that we have previously used to document the link between the kinematics and dynamics of deforming sand in the verge of frictional failure. Our initial experimental setting included a load control system that allowed us to track the changes in load, that when applied to the sand, deform and generate individual shear bands or localized faults. Over the course of earlier experiments, three cameras located at different positions outside the sandbox monitored the movement throughout the run. This current stage of analysis includes using computer programs such as QuickTime to create image sequences of the shear band formation, and Microsoft Excel to visually graph and plot each data sequence. This allows us to investigate the correlation between changes in work measured within our experiments, the construction of topography, slip along shear bands, and the creation of new shear bands. We observed that the measured load generally increased during the experiment to maintain a constant displacement rate as the sand wedge thickened and modeled topography increased. Superposed on this trend were periodic drops in load that appeared temporally coincident with the formation of shear bands in the sand. Using the time series of the loads applied during the experiment, changes in the position of the backstop over time, and the loads measured before, during, and after the time of each shear band formation, we are examining the fraction of the apples work that is absorbed by friction and shear band formation, and what fraction of the apples work is expended in increasing the potential energy of the thickening sand wedge. Our results indicate that before the formation of a continuous shear band, the rate of work done on the sand by the experimental apparatus decreases. This may suggest that once formed, work done against friction in the sand is significantly less than that expended in forming shear bands and thickening the sand wedge.

Preparation and characterization of poly(acrylic acid)—corn starch blend for use as chemical sand-fixing materials

NASA Astrophysics Data System (ADS)

Dang, Xugang; Chen, Hui; Shan, Zhihua

2017-07-01

One chemical sand-fixing materials based on poly(acrylic acid)-corn starch (PACS) blend was studied in this work. The PACS blend was prepared by solution mixing method between PA and CS. In order to prepare sand-fixing materials for environmental applications using the well-established method of spraying evenly PACS blend solution on the surfaces of fine sand. Fourier transform infrared spectroscopy (FT-IR) revealed the existence of the intermolecular interactions between the blend components. Scanning electron microscope (SEM) analysis showed a continuous phase of blend, and it also showed the good sand-fixing capacity. The test results of hygroscopicity and water retention experiments indicated that the blends had excellent water-absorbing and water-retention capacity. The results of contact angle measurements between the PACS solutions and fine sand showed that the PACS blend has a satisfactory effect on fine sand wetting. And the PACS, as a sand-fixation material, has excellent sand-fixation rate up to 99.5%.

Laparoscopic surgical box model training for surgical trainees with limited prior laparoscopic experience.

PubMed

Gurusamy, Kurinchi Selvan; Nagendran, Myura; Toon, Clare D; Davidson, Brian R

2014-03-01

Surgical training has traditionally been one of apprenticeship, where the surgical trainee learns to perform surgery under the supervision of a trained surgeon. This is time consuming, costly, and of variable effectiveness. Training using a box model physical simulator is an option to supplement standard training. However, the value of this modality on trainees with limited prior laparoscopic experience is unknown. To compare the benefits and harms of box model training for surgical trainees with limited prior laparoscopic experience versus standard surgical training or supplementary animal model training. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and Science Citation Index Expanded to May 2013. We planned to include all randomised clinical trials comparing box model trainers versus other forms of training including standard laparoscopic training and supplementary animal model training in surgical trainees with limited prior laparoscopic experience. We also planned to include trials comparing different methods of box model training. Two authors independently identified trials and collected data. We analysed the data with both the fixed-effect and the random-effects models using Review Manager 5. For each outcome, we calculated the risk ratio (RR), mean difference (MD), or standardised mean difference (SMD) with 95% confidence intervals (CI) based on intention-to-treat analysis whenever possible. We identified eight trials that met the inclusion criteria. One trial including 17 surgical trainees did not contribute to the meta-analysis. We included seven trials (249 surgical trainees belonging to various postgraduate years ranging from year one to four) in which the participants were randomised to supplementary box model training (122 trainees) versus standard training (127 trainees). Only one trial (50 trainees) was at low risk of bias. The box trainers used in all the seven trials were video trainers. Six trials were conducted in USA and one trial in Canada. The surgeries in which the final assessments were made included laparoscopic total extraperitoneal hernia repairs, laparoscopic cholecystectomy, laparoscopic tubal ligation, laparoscopic partial salpingectomy, and laparoscopic bilateral mid-segment salpingectomy. The final assessments were made on a single operative procedure.There were no deaths in three trials (0/82 (0%) supplementary box model training versus 0/86 (0%) standard training; RR not estimable; very low quality evidence). The other trials did not report mortality. The estimated effect on serious adverse events was compatible with benefit and harm (three trials; 168 patients; 0/82 (0%) supplementary box model training versus 1/86 (1.1%) standard training; RR 0.36; 95% CI 0.02 to 8.43; very low quality evidence). None of the trials reported patient quality of life. The operating time was significantly shorter in the supplementary box model training group versus the standard training group (1 trial; 50 patients; MD -6.50 minutes; 95% CI -10.85 to -2.15). The proportion of patients who were discharged as day-surgery was significantly higher in the supplementary box model training group versus the standard training group (1 trial; 50 patients; 24/24 (100%) supplementary box model training versus 15/26 (57.7%) standard training; RR 1.71; 95% CI 1.23 to 2.37). None of the trials reported trainee satisfaction. The operating performance was significantly better in the supplementary box model training group versus the standard training group (seven trials; 249 trainees; SMD 0.84; 95% CI 0.57 to 1.10).None of the trials compared box model training versus animal model training or versus different methods of box model training. There is insufficient evidence to determine whether laparoscopic box model training reduces mortality or morbidity. There is very low quality evidence that it improves technical skills compared with standard surgical training in trainees with limited previous laparoscopic experience. It may also decrease operating time and increase the proportion of patients who were discharged as day-surgery in the first total extraperitoneal hernia repair after box model training. However, the duration of the benefit of box model training is unknown. Further well-designed trials of low risk of bias and random errors are necessary. Such trials should assess the long-term impact of box model training on clinical outcomes and compare box training with other forms of training.

Bacteriophage PRD1 batch experiments to study attachment, detachment and inactivation processes

NASA Astrophysics Data System (ADS)

Sadeghi, Gholamreza; Schijven, Jack F.; Behrends, Thilo; Hassanizadeh, S. Majid; van Genuchten, Martinus Th.

2013-09-01

Knowledge of virus removal in subsurface environments is pivotal for assessing the risk of viral contamination of water resources and developing appropriate protection measures. Columns packed with sand are frequently used to quantify attachment, detachment and inactivation rates of viruses. Since column transport experiments are very laborious, a common alternative is to perform batch experiments where usually one or two measurements are done assuming equilibrium is reached. It is also possible to perform kinetic batch experiments. In that case, however, it is necessary to monitor changes in the concentration with time. This means that kinetic batch experiments will be almost as laborious as column experiments. Moreover, attachment and detachment rate coefficients derived from batch experiments may differ from those determined using column experiments. The aim of this study was to determine the utility of kinetic batch experiments and investigate the effects of different designs of the batch experiments on estimated attachment, detachment and inactivation rate coefficients. The experiments involved various combinations of container size, sand-water ratio, and mixing method (i.e., rolling or tumbling by pivoting the tubes around their horizontal or vertical axes, respectively). Batch experiments were conducted with clean quartz sand, water at pH 7 and ionic strength of 20 mM, and using the bacteriophage PRD1 as a model virus. Values of attachment, detachment and inactivation rate coefficients were found by fitting an analytical solution of the kinetic model equations to the data. Attachment rate coefficients were found to be systematically higher under tumbling than under rolling conditions because of better mixing and more efficient contact of phages with the surfaces of the sand grains. In both mixing methods, more sand in the container yielded higher attachment rate coefficients. A linear increase in the detachment rate coefficient was observed with increased solid-water ratio using tumbling method. Given the differences in the attachment rate coefficients, and assuming the same sticking efficiencies since chemical conditions of the batch and column experiments were the same, our results show that collision efficiencies of batch experiments are not the same as those of column experiments. Upscaling of the attachment rate from batch to column experiments hence requires proper understanding of the mixing conditions. Because batch experiments, in which the kinetics are monitored, are as laborious as column experiments, there seems to be no major advantage in performing batch instead of column experiments.

Precipitation of sparingly soluble salts in packed sandbeds

NASA Astrophysics Data System (ADS)

Pavlakou, Efstathia I.; Sygouni, Varvara; Paraskeva, Christakis A.

2015-04-01

One of the main problems encountered by the oil extraction industry, is the reduction of the local permeability of the rock formation near the extraction wells because of salt deposition in the pores of the rocks during the injection of brine water to displace the trapped oil ganglia within the oil formations. This phenomenon makes the oil recovery less efficient and under extreme cases the well is abandoned with a large amount of oil entrapped. Several detailed studies have been conducted in the past concerning sand bed consolidation using sparingly soluble salts for varying conditions (e.g. temperature, grain size, sand type, salt concentrations etc) and various salts [1]. Nevertheless, salt precipitation in the rock formation pores under the presence of other miscible or immiscible substances with water has not been investigated in details yet. In the present study, salt (CaCO3) precipitation experiments were performed in small beds packed with sea sand mixed with a low amount of CaCO3 seed grains. The experiments were performed using pure solutions (NaHCO3, CaCl2.2H2O) and solutions mixed with Ethylene Glycol in sand beds. Additionally, precipitation experiments were performed using pure solutions in sand beds saturated with oil phase (n-dodecane) for a wide range of solution supersaturation. During the experiments the ionic strength was kept constant. pH and concentration values of calcium ion of the effluent were measured and the precipitated salt crystals were identified using X-ray Diffraction (XRD) method. At the end of each experiment Scanning Electron Microscope (SEM) was conducted using a sample of the precipitated sand to identify the morphology of the precipitated crystals and their cohesion with sand grains. Acknowledgments This research was partially funded by the European Union (European Social Fund-ESF) and Greek National Funds through the Operational program "Education and Lifelong Learning" under the action Aristeia II (Code No 4420). References [1] Paraskeva C. A., Charalampous P. C., Stokka L. E., Klepetsanis P. G., Koutsoukos P. G., Read P., Ostvold, T. and Payatakes A. C. (2000), ''Sandbed Consolidation with Mineral Precipitation'', Journal of Colloid and Interface Science, 232, 326-339.

Identification and validation of reference genes for quantification of target gene expression with quantitative real-time PCR for tall fescue under four abiotic stresses.

PubMed

Yang, Zhimin; Chen, Yu; Hu, Baoyun; Tan, Zhiqun; Huang, Bingru

2015-01-01

Tall fescue (Festuca arundinacea Schreb.) is widely utilized as a major forage and turfgrass species in the temperate regions of the world and is a valuable plant material for studying molecular mechanisms of grass stress tolerance due to its superior drought and heat tolerance among cool-season species. Selection of suitable reference genes for quantification of target gene expression is important for the discovery of molecular mechanisms underlying improved growth traits and stress tolerance. The stability of nine potential reference genes (ACT, TUB, EF1a, GAPDH, SAND, CACS, F-box, PEPKR1 and TIP41) was evaluated using four programs, GeNorm, NormFinder, BestKeeper, and RefFinder. The combinations of SAND and TUB or TIP41 and TUB were most stably expressed in salt-treated roots or leaves. The combinations of GAPDH with TIP41 or TUB were stable in roots and leaves under drought stress. TIP41 and PEPKR1 exhibited stable expression in cold-treated roots, and the combination of F-box, TIP41 and TUB was also stable in cold-treated leaves. CACS and TUB were the two most stable reference genes in heat-stressed roots. TIP41 combined with TUB and ACT was stably expressed in heat-stressed leaves. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) assays of the target gene FaWRKY1 using the identified most stable reference genes confirmed the reliability of selected reference genes. The selection of suitable reference genes in tall fescue will allow for more accurate identification of stress-tolerance genes and molecular mechanisms conferring stress tolerance in this stress-tolerant species.

GASCan 2 payload integration

NASA Technical Reports Server (NTRS)

Cody, Dennis J.; Concepcion, Allan G.; Watras, Edward C., III

1995-01-01

This project, conducted in cooperation with the NASA Advanced Space Design Program, is part of an ongoing effort to place an experiment package into space. The goal of this project is to build and test flight-ready hardware that can be launched from the Space Shuttle. Get Away Special Canister 2 (GASCan 2) consists of three separate experiments. The Ionospheric Properties and Propagation Experiment (IPPE) determines effects of the ionosphere on radio wave propagation. The Microgravity Ignition experiment (MGI) tests the effects of combustion in a microgravity environment. The Rotational Fluid Flow experiment (RFF) examines fluid behavior under varying levels of gravity. This year the following tasks were completed: design of the IPPE antenna, X- and J-cell battery boxes, J-cell battery box enclosure, and structural bumpers; construction of the MGI canisters, MGI mounting brackets, IPPE antenna, and battery boxes; and the selection of the RFF's operating fluid and the analysis of the fluid behavior under microgravity test conditions.

The inhibitory avoidance discrimination task to investigate accuracy of memory.

PubMed

Atucha, Erika; Roozendaal, Benno

2015-01-01

The present study was aimed at developing a new inhibitory avoidance task, based on training and/or testing rats in multiple contexts, to investigate accuracy of memory. In the first experiment, male Sprague-Dawley rats were given footshock in an inhibitory avoidance apparatus and, 48 h later, retention latencies of each rat were assessed in the training apparatus (Shock box) as well as in a novel, contextually modified, apparatus. Retention latencies in the Shock box were significantly longer than those in the Novel box, indicating accurate memory of the training context. When the noradrenergic stimulant yohimbine (0.3 mg/kg, sc) was administered after the training, 48-h retention latencies in the Shock box, but not Novel box, were increased, indicating that the noradrenergic activation enhanced memory of the training experience without reducing memory accuracy. In the second experiment, rats were trained on an inhibitory avoidance discrimination task: They were first trained in an inhibitory avoidance apparatus without footshock (Non-Shock box), followed 1 min later by footshock training in a contextually modified apparatus (Shock box). Forty-eight-hour retention latencies in the Shock and Non-Shock boxes did not differ from each other but were both significantly longer than those in a Novel box, indicating that rats remembered the two training contexts but did not have episodic-like memory of the association of footshock with the correct training context. When the interval between the two training episodes was increased to 2 min, rats showed accurate memory of the association of footshock with the training context. Yohimbine administered after the training also enhanced rats' ability to remember in which training context they had received actual footshock. These findings indicate that the inhibitory avoidance discrimination task is a novel variant of the well-established inhibitory avoidance task suitable to investigate accuracy of memory.

Sand and Dust on Mars

NASA Technical Reports Server (NTRS)

Greeley, Ronald; Haberle, Robert M.

1991-01-01

Mars is a planet of high scientific interest. Various studies are currently being made that involve vehicles that have landed on Mars. Because Mars is known to experience frequent wind storms, mission planners and engineers require knowledge of the physical and chemical properties of Martian windblown sand and dust, and the processes involved in the origin and evolution of sand and dust storms.

Penetration of different human pathogenic viruses into sand columns percolated with distilled water, groundwater, or wastewater.

PubMed Central

Dizer, H; Nasser, A; Lopez, J M

1984-01-01

The adsorption of several enteroviruses and rotavirus SA11 to sand from an aquifer in the Federal Republic of Germany was estimated in sand-filled columns loaded with ca. 10(7) PFU and run at a velocity of 2.5 m/day for 12 h. After either distilled water, groundwater, secondary effluent, or tertiary effluent was percolated, the sand core was slowly extruded out of the column and cut in 1-cm slices. The slices were eluted with nutrient broth, and the amount of viruses in the broth was estimated. The best adsorption was promoted by groundwater and tertiary effluent, followed by distilled water and secondary effluent. Similar experiments, carried out at different percolation rates, indicated that a 50-day underground stay of recharged water probably suffices to eliminate viruses in the groundwater-recharged tertiary effluent. However, when viruses and sand were incubated in the presence of the surfactants sodium dodecyl sulfate, nonyl phenol, dodigen 226, or alkylbenzylsulfonate, the adsorption of the viruses was substantially diminished. Experiments in the presence of nonyl phenol seem to indicate that hydrophobic interactions are involved in the adsorption of viruses to sand. PMID:6324676

Avian Conservation Practices Strengthen Ecosystem Services in California Vineyards

PubMed Central

Jedlicka, Julie A.; Greenberg, Russell; Letourneau, Deborah K.

2011-01-01

Insectivorous Western Bluebirds (Sialia mexicana) occupy vineyard nest boxes established by California winegrape growers who want to encourage avian conservation. Experimentally, the provision of available nest sites serves as an alternative to exclosure methods for isolating the potential ecosystem services provided by foraging birds. We compared the abundance and species richness of avian foragers and removal rates of sentinel prey in treatments with songbird nest boxes and controls without nest boxes. The average species richness of avian insectivores increased by over 50 percent compared to controls. Insectivorous bird density nearly quadrupled, primarily due to a tenfold increase in Western Bluebird abundance. In contrast, there was no significant difference in the abundance of omnivorous or granivorous bird species some of which opportunistically forage on grapes. In a sentinel prey experiment, 2.4 times more live beet armyworms (Spodoptera exigua) were removed in the nest box treatment than in the control. As an estimate of the maximum foraging services provided by insectivorous birds, we found that larval removal rates measured immediately below occupied boxes averaged 3.5 times greater than in the control. Consequently the presence of Western Bluebirds in vineyard nest boxes strengthened ecosystem services to winegrape growers, illustrating a benefit of agroecological conservation practices. Predator addition and sentinel prey experiments lack some disadvantages of predator exclusion experiments and were robust methodologies for detecting ecosystem services. PMID:22096555

Avian conservation practices strengthen ecosystem services in California vineyards.

PubMed

Jedlicka, Julie A; Greenberg, Russell; Letourneau, Deborah K

2011-01-01

Insectivorous Western Bluebirds (Sialia mexicana) occupy vineyard nest boxes established by California winegrape growers who want to encourage avian conservation. Experimentally, the provision of available nest sites serves as an alternative to exclosure methods for isolating the potential ecosystem services provided by foraging birds. We compared the abundance and species richness of avian foragers and removal rates of sentinel prey in treatments with songbird nest boxes and controls without nest boxes. The average species richness of avian insectivores increased by over 50 percent compared to controls. Insectivorous bird density nearly quadrupled, primarily due to a tenfold increase in Western Bluebird abundance. In contrast, there was no significant difference in the abundance of omnivorous or granivorous bird species some of which opportunistically forage on grapes. In a sentinel prey experiment, 2.4 times more live beet armyworms (Spodoptera exigua) were removed in the nest box treatment than in the control. As an estimate of the maximum foraging services provided by insectivorous birds, we found that larval removal rates measured immediately below occupied boxes averaged 3.5 times greater than in the control. Consequently the presence of Western Bluebirds in vineyard nest boxes strengthened ecosystem services to winegrape growers, illustrating a benefit of agroecological conservation practices. Predator addition and sentinel prey experiments lack some disadvantages of predator exclusion experiments and were robust methodologies for detecting ecosystem services.

Microbial Transport Mechanisms in Silty, Sandy Media as Inferred From Short Core Experiments Performed in the Field.

NASA Astrophysics Data System (ADS)

Mailloux, B.; Hall, j; Fuller, M.; Scheibe, T.; DeFlaun, M.; Onstott, T.

2001-12-01

A novel approach to examining the mechanisms controlling the velocity and attachment of bacteria in porous media was developed for the South Oyster Bacterial Transport Field Site. Instead of performing bacterial transport experiments in the lab using repacked materials and artificial water, samples of sediment core, 7 cm. in length, were connected to multi-level samplers at the field site, the groundwater from select levels in the aquifer was pumped through the cores, and an aliquot of cells stained with a viable, fluorescent dye was injected with Br into the influent end of the cores. The same cells, Br and groundwater were simultaneously passed through repacked cores composed of sieved sand of varying grain size fractions (100 to 600  diameter) and a single grain size fraction coated with Fe and Al synthetic oxides. The grain size of the coated sand and the Fe and Al concentrations of the coated sand (500 to 1000 ppm) were representative of the average value of the aquifer. By using this approach, the parameters that are difficult to reproduce in the lab, e.g., the dissolved gas concentrations, pH, temperature, dissolved organic matter, the indigenous bacterial and protist populations, could be replicated. One of the results derived from 29 short core experiments indicate that the enhanced velocity of adhesion deficient DA001 that has been reported in laboratory experiments was greatly reduced in the field experiments for the Fe and Al coated sands and greatly enhanced for the fine grained sands.

The sand-deposition impact of artificial gravel beds on the protection of the Mogao Grottoes

PubMed Central

Li, Guo Shuai; Qu, Jian Jun; Li, Xu Zhi; Wang, Wan Fu

2014-01-01

Gravel beds can prevent sand-dust emission and weaken sand-dust flux. We used wind-tunnel experiments and field observations on artificial gravel beds above the Mogao Grottoes to quantify their impact. In the report, we identified a significant correlation between gravel roughness and its ability to trap wind-transported sand. The optimal combinations of gravel diameter and coverage were determined. The greatest roughness is achieved when small gravel coverage is 75%, medium 40% and large 45%. We found that initial wind speed and gravel coverage are the key factors controlling the amount of sand trapped by the gravel beds. PMID:24614183

Influence of permeability on nanoscale zero-valent iron particle transport in saturated homogeneous and heterogeneous porous media.

PubMed

Strutz, Tessa J; Hornbruch, Götz; Dahmke, Andreas; Köber, Ralf

2016-09-01

Nanoscale zero-valent iron (NZVI) particles can be used for in situ groundwater remediation. The spatial particle distribution plays a very important role in successful and efficient remediation, especially in heterogeneous systems. Initial sand permeability (k 0) influences on spatial particle distributions were investigated and quantified in homogeneous and heterogeneous systems within the presented study. Four homogeneously filled column experiments and a heterogeneously filled tank experiment, using different median sand grain diameters (d 50), were performed to determine if NZVI particles were transported into finer sand where contaminants could be trapped. More NZVI particle retention, less particle transport, and faster decrease in k were observed in the column studies using finer sands than in those using coarser sands, reflecting a function of k 0. In heterogeneous media, NZVI particles were initially transported and deposited in coarse sand areas. Increasing the retained NZVI mass (decreasing k in particle deposition areas) caused NZVI particles to also be transported into finer sand areas, forming an area with a relatively homogeneous particle distribution and converged k values despite the different grain sizes present. The deposited-particle surface area contribution to the increasing of the matrix surface area (θ) was one to two orders of magnitude higher for finer than coarser sand. The dependency of θ on d 50 presumably affects simulated k changes and NZVI distributions in numerical simulations of NZVI injections into heterogeneous aquifers. The results implied that NZVI can in principle also penetrate finer layers.

Examination of pulverized waste recycled glass as filter media in slow sand filtration. Final report

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

Piccirillo, J.B.; Letterman, R.D.

1997-10-01

The purpose of this study was to investigate the pulverization of waste recycled glass to produce glass sand for slow sand filters. Pulverization experiments were performed using a fail mill pulverizer. The glass sand product from the pulverizer meets the size distribution requirements of ASTM-C-33 without size distribution adjustment. The size distribution must be adjusted to meet the grain size distribution requirements of the Ten States Standards and the USEPA for filter media used in slow sand filters. Pulverized glass that meet slow sand filter media specifications is an effective alternative to silica sand as a filter media for slowmore » sand filtration. Three pilot plant slow sand filters with glass sand filter media were compared to a fourth filter containing silica sand filter media. Over an 8 month period of continuous operation, the performance of the glass sand filter media was as good or better than the silica sands, with removals of 56% to 96% for turbidity; 99.78% to 100.0% for coliform bacteria; 99.995% to 99.997% for giardia cysts; 99.92% and 99.97% for cryptosporidium oocysts. Based on a cost-benefit analysis, converting waste glass into filter media may be economically advantageous for recycling facilities.« less

A Classification of Subaqueous Density Flows Based on Transformations From Proximal to Distal Regions

NASA Astrophysics Data System (ADS)

Hermidas, Navid; Eggenhuisen, Joris; Luthi, Stefan; Silva Jacinto, Ricardo; Toth, Ferenc; Pohl, Florian

2017-04-01

Transformations of a subaqueous density flow from proximal to distal regions are investigated. A classification of these transformations based on the state of the free shear and boundary layers and existence of a plug layer during transition from a debris flow to a turbidity current is presented. A connection between the emplaced deposit by the flow and the relevant flow type is drawn through the results obtained from a series of laboratory flume experiments. These were performed using 9%, 15%, and 21% sediment mixture concentrations composed of sand, silt, clay, and tap water, on varying bed slopes of 6°, 8°, and 9.5°, and with discharge rates of 10[m3/h] and 15[m3/h]. Stress-controlled rheometry experiments were performed on the mixtures to obtain apparent viscosity data. A classification was developed based on the imposed flow conditions, where a cohesive flow may fall within one of five distinct flow types: 1) a cohesive plug flow (PF) with a laminar free shear and boundary layers, 2) a top transitional plug flow (TTPF) containing a turbulent free shear layer, a plug layer, and a laminar boundary layer, 3) a complete transitional plug flow (CTPF) consisting of a turbulent free shear and boundary layers and a plug, 4) a transitional turbidity current (TTC) with a turbulent free shear layer and a laminar boundary layer, and, 5) a completely turbulent turbidity current (TC). During the experiments, flow type PF resulted in en masse deposition of a thick uniform ungraded muddy sand mixture, which was emplaced once the yield stress overcame the gravitational forces within the tail region of the flow. Flow type TTPF resulted in deposition of a thin ungraded basal clean sand layer during the run. This layer was covered by a muddy sand deposit from the tail. Flow type TTC did not deposit any sediment during the run. A uniform muddy sand mixture was emplaced by the tail of the flow. Flow type TC resulted in deposition of poorly sorted massive bottom sand layer. This layer was overlain by either a muddy sand mixture or a sand and silt planar lamination. Flow type CTPF was not observed during the experiments. Furthermore, it was observed that flows which are in transition from a TTC to a TTPF result in a thin bottom clean sand layer covered by a banded transitional interval. This was overlain by a muddy sand layer and a very thin clean sand layer, resulting from traction by dilute turbulent wake. In all cases a mud cap was emplaced on top of the deposit after the runs were terminated.

Dissolved phosphorus retention of light-weight expanded shale and masonry sand used in subsurface flow treatment wetlands.

PubMed

Forbes, Margaret G; Dickson, Kenneth R; Golden, Teresa D; Hudak, Paul; Doyle, Robert D

2004-02-01

Using surface flow constructed wetlands for long-term phosphorus (P) retention presents a challenge due to the fact that P is stored primarily in the sediments. Subsurface flow wetlands have the potential to greatly increase P retention; however, the substrate needs to have both high hydraulic conductivity and high P sorption capacity. The objective of our study was to assess the P retention capacity of two substrates, masonry sand and lightweight expanded shale. We used sorption/desorption isotherms, flow-through column experiments, and pilot-scale wetlands to quantify P retained from treated municipal wastewater. Langmuir sorption isotherms predicted that the expanded shale has a maximum sorption capacity of 971 mg/kg and the masonry sand 58.8 mg/kg. In column desorption and column flow-through experiments, the masonry sand desorbed P when exposed to dilute P solutions. The expanded shale, however, had very little desorption and phosphorus did not break through the columns during our experiment. In pilot cells, masonry sand retained (mean +/- standard deviation) 45 +/- 62 g P/m2/yr and expanded shale retained 164 +/- 110 g P/m2/yr. We conclude that only the expanded shale would be a suitable substrate for retaining P in a subsurface flow wetland.

Adaptation to life in aeolian sand: how the sandfish lizard, Scincus scincus, prevents sand particles from entering its lungs.

PubMed

Stadler, Anna T; Vihar, Boštjan; Günther, Mathias; Huemer, Michaela; Riedl, Martin; Shamiyeh, Stephanie; Mayrhofer, Bernhard; Böhme, Wolfgang; Baumgartner, Werner

2016-11-15

The sandfish lizard, Scincus scincus (Squamata: Scincidae), spends nearly its whole life in aeolian sand and only comes to the surface for foraging, defecating and mating. It is not yet understood how the animal can respire without sand particles entering its respiratory organs when buried under thick layers of sand. In this work, we integrated biological studies, computational calculations and physical experiments to understand this phenomenon. We present a 3D model of the upper respiratory system based on a detailed histological analysis. A 3D-printed version of this model was used in combination with characteristic ventilation patterns for computational calculations and fluid mechanics experiments. By calculating the velocity field, we identified a sharp decrease in velocity in the anterior part of the nasal cavity where mucus and cilia are present. The experiments with the 3D-printed model validate the calculations: particles, if present, were found only in the same area as suggested by the calculations. We postulate that the sandfish has an aerodynamic filtering system; more specifically, that the characteristic morphology of the respiratory channel coupled with specific ventilation patterns prevent particles from entering the lungs. © 2016. Published by The Company of Biologists Ltd.

Infants use compression information to infer objects’ weights: Examining cognition, exploration, and prospective action in a preferential-reaching task

PubMed Central

Hauf, Petra; Paulus, Markus; Baillargeon, Renée

2012-01-01

The present research used a preferential-reaching task to examine whether 9- and 11-month-olds (n = 144) could infer the relative weights of two objects resting on a soft, compressible platform. Experiment 1 established that infants reached preferentially for the lighter of two boxes. In Experiments 2 to 4, infants saw two boxes identical except in weight resting on a cotton wool platform. Infants reached prospectively for the lighter box, but only when their initial exploratory activities provided critical information. At 11 months, infants succeeded as long as they first determined that the platform was compressible; at 9 months, infants succeeded only if they also explored the boxes and thus had advance knowledge that they differed in weight. PMID:22861050

Validation of Reference Genes for Gene Expression Studies in Virus-Infected Nicotiana benthamiana Using Quantitative Real-Time PCR

PubMed Central

Han, Chenggui; Yu, Jialin; Li, Dawei; Zhang, Yongliang

2012-01-01

Nicotiana benthamiana is the most widely-used experimental host in plant virology. The recent release of the draft genome sequence for N. benthamiana consolidates its role as a model for plant–pathogen interactions. Quantitative real-time PCR (qPCR) is commonly employed for quantitative gene expression analysis. For valid qPCR analysis, accurate normalisation of gene expression against an appropriate internal control is required. Yet there has been little systematic investigation of reference gene stability in N. benthamiana under conditions of viral infections. In this study, the expression profiles of 16 commonly used housekeeping genes (GAPDH, 18S, EF1α, SAMD, L23, UK, PP2A, APR, UBI3, SAND, ACT, TUB, GBP, F-BOX, PPR and TIP41) were determined in N. benthamiana and those with acceptable expression levels were further selected for transcript stability analysis by qPCR of complementary DNA prepared from N. benthamiana leaf tissue infected with one of five RNA plant viruses (Tobacco necrosis virus A, Beet black scorch virus, Beet necrotic yellow vein virus, Barley stripe mosaic virus and Potato virus X). Gene stability was analysed in parallel by three commonly-used dedicated algorithms: geNorm, NormFinder and BestKeeper. Statistical analysis revealed that the PP2A, F-BOX and L23 genes were the most stable overall, and that the combination of these three genes was sufficient for accurate normalisation. In addition, the suitability of PP2A, F-BOX and L23 as reference genes was illustrated by expression-level analysis of AGO2 and RdR6 in virus-infected N. benthamiana leaves. This is the first study to systematically examine and evaluate the stability of different reference genes in N. benthamiana. Our results not only provide researchers studying these viruses a shortlist of potential housekeeping genes to use as normalisers for qPCR experiments, but should also guide the selection of appropriate reference genes for gene expression studies of N. benthamiana under other biotic and abiotic stress conditions. PMID:23029521

Comparison of postbuckling model and finite element model with compression strength of corrugated boxes

Treesearch

Thomas J. Urbanik; Edmond P. Saliklis

2002-01-01

Conventional compression strength formulas for corrugated fiberboard boxes are limited to geometry and material that produce an elastic postbuckling failure. Inelastic postbuckling can occur in squatty boxes and trays, but a mechanistic rationale for unifying observed strength data is lacking. This study employs a finite element model, instead of actual experiments, to...

The Development of Regret

ERIC Educational Resources Information Center

O'Connor, Eimear; McCormack, Teresa; Feeney, Aidan

2012-01-01

In two experiments, 4- to 9-year-olds played a game in which they selected one of two boxes to win a prize. On "regret" trials the unchosen box contained a better prize than the prize children actually won, and on "baseline" trials the other box contained a prize of the same value. Children rated their feelings about their prize before and after…

Experimental Determination of Unknown Masses and Their Positions in a Mechanical Black Box

ERIC Educational Resources Information Center

Chakrabarti, Bhupati; Pathare, Shirish; Huli, Saurabhee; Nachane, Madhura

2013-01-01

An experiment with a mechanical black box containing unknown masses is presented. The experiment involves the determination of these masses and their locations by performing some nondestructive tests. The set-ups are inexpensive and easy to fabricate. They are very useful to gain an understanding of some well-known principles of mechanics.

Modeling Hidden Circuits: An Authentic Research Experience in One Lab Period

ERIC Educational Resources Information Center

Moore, J. Christopher; Rubbo, Louis J.

2016-01-01

Two wires exit a black box that has three exposed light bulbs connected together in an unknown configuration. The task for students is to determine the circuit configuration without opening the box. In the activity described in this paper, we navigate students through the process of making models, developing and conducting experiments that can…

DSMC simulations of vapor transport toward development of the lithium vapor box divertor concept

NASA Astrophysics Data System (ADS)

Jagoe, Christopher; Schwartz, Jacob; Goldston, Robert

2016-10-01

The lithium vapor divertor box concept attempts to achieve volumetric dissipation of the high heat efflux from a fusion power system. The vapor extracts the heat of the incoming plasma by ionization and radiation, while remaining localized in the vapor box due to differential pumping based on rapid condensation. Preliminary calculations with lithium vapor at densities appropriate for an NSTX-U-scale machine give Knudsen numbers between 0.01 and 1, outside both the range of continuum fluid dynamics and of collisionless Monte Carlo. The direct-simulation Monte Carlo (DSMC) method, however, can simulate rarefied gas flows in this regime. Using the solver contained in the OpenFOAM package, pressure-driven flows of water vapor will be analyzed. The use of water vapor in the relevant range of Knudsen number allows for a flexible similarity experiment to verify the reliability of the code before moving to tests with lithium. The simulation geometry consists of chains of boxes on a temperature gradient, connected by slots with widths that are a representative fraction of the dimensions of the box. We expect choked flow, sonic shocks, and order-of-magnitude pressure and density drops from box to box, but this expectation will be tested in the simulation and then experiment. This work is supported by the Princeton Environmental Institute.

Potential of iron sand from Betaf beach, Sarmi regency and river sand from Doyo, Jayapura regency, Papua as basic materials of mortar as nuclear radiation shielding

NASA Astrophysics Data System (ADS)

Haryati, E.; Dahlan, K.

2018-03-01

According to the SNI, the type of concrete for use as nuclear radiation shielding is concrete or mortar that contains hematite, ilmenite, magnetite, barite, or ferrophosphorus synthesis. This study is focused on the characterization of iron sand from and river sand from Papua. The purpose of this research was to determine the specific content of gravity and minerals in iron sand and river sand from Papua. The specific gravities of the sands were measured by manual experiment in a laboratory, while their mineral content were calculated using XRF and SEM - EDS method. The result showed that the specific gravities of iron sand and river sand were 2.66 and 2.50, respectively. The XRF method revealed that the iron sand contained 41.68% Silica, 33.84% Iron, and 24.48% other minerals. The river sand on the other hand contained 58.98% Silica (Si), 26.87% Iron (Fe), and 14.15% other minerals. The SEM -EDS method showed that the iron sand was composed of 39.99 % SiO2, 21.67 % FeO, and, and 38.34 % others; while the river sand contained 39.28% SiO2, 17.45 % FeO, and 43.27 % others. The result showed that both sands have the potentials to be isolated from hematite minerals or magnetite.

Electrochemical and Dry Sand Impact Erosion Studies on Carbon Steel

PubMed Central

Naz, M. Y.; Ismail, N. I.; Sulaiman, S. A.; Shukrullah, S.

2015-01-01

This study investigated the dry and aqueous erosion of mild steel using electrochemical and dry sand impact techniques. In dry sand impact experiments, mild steel was eroded with 45 μm and 150 μm sand particles. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and micro-hardness techniques were used to elaborate the surface morphology of the eroded samples. The results revealed significant change in morphology of the eroded samples. In-depth analysis showed that although the metal erosion due to larger particles was significantly higher, the fines also notably damaged the metal surface. The surface damages were appreciably reduced with decrease in impact angle of the accelerated particles. The maximum damages were observed at an impact angle of 90°. The hardness of the samples treated with 45 μm and 150 μm sand remained in the range of 88.34 to 102.31 VHN and 87.7 to 97.55 VHN, respectively. In electrochemical experiments, a triple electrode probe was added into the metal treatment process. The linear polarization resistance (LPR) measurements were performed in slurries having 5% (by weight) of sand particles. LPR of the samples treated with 45 μm and 150 μm sand slurries was calculated about 949 Ω.cm2 and 809 Ω.cm2, respectively. PMID:26561231

Electrochemical and Dry Sand Impact Erosion Studies on Carbon Steel.

PubMed

Naz, M Y; Ismail, N I; Sulaiman, S A; Shukrullah, S

2015-11-12

This study investigated the dry and aqueous erosion of mild steel using electrochemical and dry sand impact techniques. In dry sand impact experiments, mild steel was eroded with 45 μm and 150 μm sand particles. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and micro-hardness techniques were used to elaborate the surface morphology of the eroded samples. The results revealed significant change in morphology of the eroded samples. In-depth analysis showed that although the metal erosion due to larger particles was significantly higher, the fines also notably damaged the metal surface. The surface damages were appreciably reduced with decrease in impact angle of the accelerated particles. The maximum damages were observed at an impact angle of 90°. The hardness of the samples treated with 45 μm and 150 μm sand remained in the range of 88.34 to 102.31 VHN and 87.7 to 97.55 VHN, respectively. In electrochemical experiments, a triple electrode probe was added into the metal treatment process. The linear polarization resistance (LPR) measurements were performed in slurries having 5% (by weight) of sand particles. LPR of the samples treated with 45 μm and 150 μm sand slurries was calculated about 949 Ω.cm(2) and 809 Ω.cm(2), respectively.

Measuring Helicase Inhibition of the DEAD-box Protein Dbp2 by Yra1

PubMed Central

Ma, Wai Kit; Tran, Elizabeth J.

2016-01-01

Despite the highly conserved helicase core, individual DEAD-box proteins are specialized in diverse RNA metabolic processes. One mechanism that determines DEAD-box protein specificity is enzymatic regulation by other protein cofactors. In this chapter, we describe a protocol for purifying the Saccharomyces cerevisiae DEAD-box RNA helicase Dbp2 and RNA-binding protein Yra1 and subsequent analysis of helicase regulation. The experiments described here can be adapted to RNA helicase and purified co-factor. PMID:25579587

A field study of littoral processes in Estero Bay, California

USGS Publications Warehouse

Dingler, J.R.; Anima, R.J.; Molzan, D.E.; Luepke, Gretchen; Peterson, C.L.

1982-01-01

Estero Bay, which lies on the central California coast, has rocky headlands at both ends and sandy beaches within it. The shoreline of the bay has adjusted to be in equilibrium with the predominant wave climate, which is from the northwest. Because of its present shoreline configuration, the net southward littoral transport found along much of the California coast does not occur within Estero Bay. Instead, the sand primarily moves on- and offshore with a reversing longshore component. This sand transport pattern produces a littoral cell within Estero Bay even though there is no submarine canyon in the area. The primary sand sinks for this cell appear to be the sand spit south of Morro Rock and the entrance to Morro Bay itself, although this opinion was not experimentally verified. Field work during one summer (1978) and the following winter (1979) produced baseline data on the profile of and grain-size distribution across the littoral zone. In the offshore part of the littoral zone we also studied ripple size and type, internal structure, depth of erosion, and mineralogy. Although these data, which were collected along nine transects spaced 2 km apart, are inadequate to yield transport and energy rates, they indicate a northward decrease in wave energy within Estero Bay and a mixing of the sediments in the offshore. Box core and rod height data from grid points in seven meters of water showed that on the order of a meter of erosion occurred in the central part of the bay between the two sampling periods. Offshore, the data were incomplete, but at one station, in 17 m of water, at least 20 cm of erosion occurred.

Quantifying and communicating the uncertainty of mineral resource evaluations

NASA Astrophysics Data System (ADS)

Mee, Katy; Marchant, Ben; Mankelow, Joseph; Deady, Eimear

2015-04-01

Three-dimensional subsurface models are increasingly being used to assess the value of sand and gravel mineral deposits. Planners might use this information to decide when deposits should be protected from new developments. The models are generally based on interpretations of relatively sparse boreholes and are therefore uncertain. This uncertainty propagates into the predictions of the value of the deposit and must be quantified and communicated to planners in a manner which permits informed decision-making. We discuss these issues in relation to a 60 km by 40 km study area in the south of England. We use the interpretations of 630 boreholes to build statistical models of the subsurface. Mineral deposit categories are defined in terms of the ratio of mineral depth to overburden depth and the proportion of fine particles within the mineral. We use a linear model of coregionalization to model the spatial distribution of these parameters. Furthermore, we use stochastic simulation methods to produce maps of the probability of each category of mineral deposit occurring at each location in the study area. These maps indicate where deposits of suitable sand and gravel might be expected to occur. However, they are only telling us the probability that if a borehole was to be drilled at a location that its contents would satisfy the criteria of each mineral category. Planners require information for areas much larger than a single borehole. Therefore, we demonstrate how the model can be up-scaled to a 1 km2 site. We again use a stochastic simulation method to produce box-whisker plots which illustrate the proportions of gravels, sands, fine sands and fine material that are predicted to occur in the region and the uncertainty associated with the predictions.

Compressive behavior of fine sand.

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

Martin, Bradley E.; Kabir, Md. E.; Song, Bo

2010-04-01

The compressive mechanical response of fine sand is experimentally investigated. The strain rate, initial density, stress state, and moisture level are systematically varied. A Kolsky bar was modified to obtain uniaxial and triaxial compressive response at high strain rates. A controlled loading pulse allows the specimen to acquire stress equilibrium and constant strain-rates. The results show that the compressive response of the fine sand is not sensitive to strain rate under the loading conditions in this study, but significantly dependent on the moisture content, initial density and lateral confinement. Partially saturated sand is more compliant than dry sand. Similar trendsmore » were reported in the quasi-static regime for experiments conducted at comparable specimen conditions. The sand becomes stiffer as initial density and/or confinement pressure increases. The sand particle size become smaller after hydrostatic pressure and further smaller after dynamic axial loading.« less

Sand dredging and environmental efficiency of artisanal fishermen in Lagos state, Nigeria.

PubMed

Sowunmi, Fatai A; Hogarh, Jonathan N; Agbola, Peter O; Atewamba, Calvin

2016-03-01

Environmentally detrimental input (water turbidity) and conventional production inputs were considered within the framework of stochastic frontier analysis to estimate technical and environmental efficiencies of fishermen in sand dredging and non-dredging areas. Environmental efficiency was low among fishermen in the sand dredging areas. Educational status and experience in fishing and sand dredging were the factors influencing environmental efficiency in the sand dredging areas. Average quantity of fish caught per labour- hour was higher among fishermen in the non-dredging areas. Fishermen in the fishing community around the dredging areas travelled long distance in order to reduce the negative effect of sand dredging on their fishing activity. The study affirmed large household size among fishermen. The need to regulate the activities of sand dredgers by restricting license for sand dredging to non-fishing communities as well as intensifying family planning campaign in fishing communities to reduce the negative effect of high household size on fishing is imperative for the sustainability of artisanal fishing.

Tidal and Lunar Data for Point Mugu, San Nicolas Island, and the Barking Sands Area During 1988.

DTIC Science & Technology

1987-12-31

C l vNvN-A -0%Ow’!’N N r--Me’a In v-(v0r-v inav -f -X W WI- 0 -!)0 N~o CD NI- 0V NMQ-N o ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ V KU LMM tt-y d tL) J O’ed.ci I o -a NM...Commander Third Fleet 1 Pearl Harbor, HI 96860-7500 Commander Naval Weapons Center Attn: Earth and Planetary Sciences Division 1 Code 343 (Technical...Center P.O. Box 271 Attn: Fishery-Oceanographic Group La Jolla, CA 92037 University of California Department of Biological Sciences Attn: Dr. A. M

Some Experiments on Evaporation of High-TDS Phreatic Water in an Arid Area

NASA Astrophysics Data System (ADS)

Li, X.; Jin, M.; Zhou, J.; Liu, Y.; Zhao, Y.

2012-12-01

Most experiments that had been done on evaporation of phreatic water were limited to waters with fresh or low total dissolved solids (TDS, no more than 10g/L). The TDS of phreatic water is always dozens or even hundreds of grams per liter in extremely arid areas. Thus, experiments on phreatic water evaporation of different TDS (3g/L, 30g/L, 100g/L, 250g/L) were carried out in an arid plain of south Xinjiang, China. The results showed that there was significant linear positive correlation between TDS of phreatic water and cumulative salinity in soil profile. The variation of phreatic water evaporation was lag behind the change of surface water measured by E20 equipment, but both of them were more drastic at nighttime than the daytime. The research shows that the daytime evaporation capacity has significant effect on nighttime evaporation, and the soil water vapor condense at profile also is an important driving factor for the nighttime evaporation. Capillary rise is a significant contributor of soil salinity in extremely arid areas. Experiments about effects of different grains of sand soil and TDS of phreatic water (1, 30, 100, 250 g/L) on capillary rise showed that TDS had significant effects on capillary rise in later stage of experiments. For coarse sand, the higher TDS made the lower height of capillary rise. But for fine sand, the height of capillary rise of 1g/L was obviously larger than others. The sequence of height from larger to lower of capillary rise in silt was 30, 100, 250 and 1g/L. At the beginning of experiments on coarse sand, the higher TDS made the lower velocity of capillary rise, but other soil groups were not. Compared to high-TDS, the grain of sand soil was a more primary controlling factor of capillary rise. The research indicates that high-TDS not only changes the gravity of capillary water but also the pore size of soil during the processes of capillary rise in fine sand.

Temperature-dependent residual shear strength characteristics of smectite-rich landslide soils

NASA Astrophysics Data System (ADS)

Shibasaki, Tatsuya; Matsuura, Sumio; Okamoto, Takashi

2015-04-01

On gentle clayey slopes in weathered argillaceous rock areas, there exist many landslides which repeatedly reactivate with slow movement. The slip surface soils of these landslides are sometimes composed dominantly of swelling clay mineral (smectite) which is well known to show extremely low residual friction angle. From field data monitored at landslide sites in Japan, it has become clear that some landslides with relatively shallow slip surface begin to move and become active in late autumn or early winter every year. In such cases, the triggering mechanisms of landslides have not been understood well enough, because landslide initiation and movement are not always clearly linked with rises in pore water pressures (ground water levels). In this study, we focus on the influence of seasonal variation in ground temperature on slope stability and have investigated the effect of temperature on the shear strength of slip surface soils. Undisturbed soil samples were collected by boring from the Busuno landslide in Japan. We performed box shear experiments on undisturbed slip surface soils at low temperature ranges (approximately 5-25 °C). XRD analysis revealed that these soils contain high fraction of smectite. Slickensided slip surface within test specimen was coincided with the shearing plane of the shear box and shear displacement was applied precisely along the localized slip surface. Experiments were performed under slow shearing rate condition (0.005mm/min) and the results showed that shear strength decreased with decreasing temperature. Temperature effect was rather significant on frictional angle than on cohesion. Ring shear experiments were also performed on normally-consolidated remoulded samples. Under residual strength condition, temperature-change experiments (cooling-event tests) ranging approximately from 5 to 25 °C were performed on smectite-rich landslide soils and commercial bentonites. As well as the results by box shear test, shear weakening behaviors were also recognized during cooling-event tests. Shear stress fluctuations, which were obtained by 1 Hz data sampling, showed that shear behavior characteristically changed in response to temperature conditions. Stick-slip behavior prevailed under room temperature conditions, whereas shear behavior gradually changed into stable sliding behavior as temperature decreased. SEM (Scanning Electric Microscope) observation on shear surfaces indicated that silt- and sand-size asperities in the vicinity of the shear surface influence the occurrence of stick-slip behavior. It is also characteristically noted that rod-shaped smectitic clays, here called "roll", developed on shear surfaces and are arrayed densely perpendicular to the shearing direction in a micrometer scale. We assume that these rolls are probably rotating slowly within shear zone and acting as a lubricant which affects the temperature-dependent frictional properties of the shearing plane. These experimental results show that residual strength characteristics of smectite-rich soils are sensitive to temperature conditions. Our findings imply that if slip surface soils contain a high fraction of smectite, a decrease in ground temperature can lead to lowered shear resistance of the slip surface and triggering of slow landslide movement.

Mystery Boxes, X Rays, and Radiology.

ERIC Educational Resources Information Center

Thomson, Norman

2000-01-01

Indicates the difficulties of teaching concepts beyond light and color and creating memorable learning experiences. Recommends sequential activities using the mystery box approach to explain how scientists and doctors use photon applications. (YDS)

Active video games as a form of exercise and the effect of gaming experience: a preliminary study in healthy young adults.

PubMed

O'Donovan, C; Hussey, J

2012-09-01

To examine the energy expenditure and heart rate response while playing active video games, and the effect of gaming experience on energy expenditure. Cross-sectional study. Twenty-eight healthy participants (18 male, age 19 to 27 years) played either Wii Sports Boxing, Tennis and Baseball, or Wii Sports Boxing and Wii Fit Free Jogging. Percentage maximal heart rate (%HRmax) and metabolic equivalents (METs) were measured during 15 minutes of rest and during each game. Mean %HRmax and METs while playing each of the four games were as follows: Wii Fit Free Jogging 71% [standard deviation (SD) 13%], 5.9 (SD 1.8); Wii Sports Boxing 58% (SD 13%), 3.2 (SD 1.1); Wii Sports Baseball 42% (SD 6%), 2.0 (SD 0.5); and Wii Sports Tennis 42% (SD 7%), 2.0 (SD 0.4). Subjects with gaming experience achieved a lower heart rate playing Wii Sports Tennis compared with subjects without gaming experience. Wii Sports Boxing, Tennis and Baseball are light-intensity activities, and Wii Fit Free Jogging is a moderate-intensity activity. Experience of gaming may affect the exercise intensity of games requiring controller skill. Copyright © 2012 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

The Laser Synthesis of Linear Polyynes: The Particle in a Box Revisited

ERIC Educational Resources Information Center

Anderson, Bruce D.; Gordon, Christopher M.

2008-01-01

In this experiment, linear polyynes are synthesized and then the predictions of a one-dimensional, particle in a box are used to calculate the quantum mechanical box length for the polyynes. A solution of graphite in ethanol is irradiated with a Nd:YAG laser (532 nm) and the resulting solution is filtered and analyzed. Data from gas…

Self-inhibition can limit biologically enhanced TCE dissolution from a TCE DNAPL.

PubMed

Haest, P J; Springael, D; Seuntjens, P; Smolders, E

2012-11-01

Biodegradation of trichloroethene (TCE) near a Dense Non Aqueous Phase Liquid (DNAPL) can enhance the dissolution rate of the DNAPL by increasing the concentration gradient at the DNAPL-water interface. Two-dimensional flow-through sand boxes containing a TCE DNAPL and inoculated with a TCE dechlorinating consortium were set up to measure this bio-enhanced dissolution under anaerobic conditions. The total mass of TCE and daughter products in the effluent of the biotic boxes was 3-6 fold larger than in the effluent of the abiotic box. However, the mass of daughter products only accounted for 19-55% of the total mass of chlorinated compounds in the effluent, suggesting that bio-enhanced dissolution factors were maximally 1.3-2.2. The enhanced dissolution most likely primarily resulted from variable DNAPL distribution rather than biodegradation. Specific dechlorination rates previously determined in a stirred liquid medium were used in a reactive transport model to identify the rate limiting factors. The model adequately simulated the overall TCE degradation when predicted resident microbial numbers approached observed values and indicated an enhancement factor for TCE dissolution of 1.01. The model shows that dechlorination of TCE in the 2D box was limited due to the short residence time and the self-inhibition of the TCE degradation. A parameter sensitivity analysis predicts that the bio-enhanced dissolution factor for this TCE source zone can only exceed a value of 2 if the TCE self-inhibition is drastically reduced (when a TCE tolerant dehalogenating community is present) or if the DNAPL is located in a low-permeable layer with a small Darcy velocity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Non-local boxes and their implementation in Minecraft

NASA Astrophysics Data System (ADS)

Simnacher, Timo Yannick

PR-boxes are binary devices connecting two remote parties satisfying x AND y = a + b mod 2, where x and y denote the binary inputs and a and b are the respective outcomes without signaling. These devices are named after their inventors Sandu Popescu and Daniel Rohrlich and saturate the Clauser-Horne-Shimony-Holt (CHSH) inequality. This Bell-like inequality bounds the correlation that can exist between two remote, non-signaling, classical systems described by local hidden variable theories. Experiments have now convincingly shown that quantum entanglement cannot be explained by local hidden variable theories. Furthermore, the CHSH inequality provides a method to distinguish quantum systems from super-quantum correlations. The correlation between the outputs of the PR-box goes beyond any quantum entanglement. Though PR-boxes would have impressive consequences, as far as we know they are not physically realizable. However, by introducing PR-boxes to Minecraft as part of the redstone system, which simulates the electrical components for binary computing, we can experience the consequences of super-quantum correlations. For instance, Wim van Dam proved that two parties can use a sufficient number of PR-boxes to compute any Boolean function f(x,y) with only one bit of communication.

[Parameters optimization and cleaning efficiency evaluation of attrition scrubbing remediation of Pb-contaminated soil].

PubMed

Yang, Wen; Huang, Jin-lou; Peng, Hui-qing; Li, Si-tuo

2013-09-01

Attrition scrubbing was used to remediate lead contaminated-site soil, and the main purpose was to remove fine particles and lead contaminants from the surface of sand. The optimal parameters of attrition scrubbing were determined by orthogonal experiment, and three soil samples with different lead concentration were subjected to attrition scrubbing experiments. The results showed that the optimal scrubbing parameters were: a solid ratio of 70% dry matter, a temperature of 25 degrees C, an attrition time of 30 min, and an attrition speed of 1200 r x min(-1). Before attrition scrubbing, the screening and analysis of soil showed that in all three soil samples, lead was mainly enriched on sand and fine particles, and the distribution of lead was highly correlated to the organic matter. After attrition scrubbing, the washing efficiency of the original state lead contaminated sand soil in triplicates was 67.61%, 31.71% and 41.01%, respectively, which indicates that attrition scrubbing can remove part of the fine soil and lead contaminants from the surface of sand, to accomplish the purpose of pollutants enrichment. Scanning electron microscopy (SEM) analysis showed that the sand surface became smooth after attrition scrubbing. The results above show that attrition scrubbing has a good washing effect for the remediation of lead contaminated sand soil.

Sand filter clogging by septic tank effluent.

PubMed

Spychała, M; Błazejewski, R

2003-01-01

The aim of this study was to characterise conditions and factors affecting fine sand clogging by septic tank effluent on the basis of physical modelling. The physical model consisted of 12 sand columns dosed with sewage from one household (5 persons), preliminary treated in a septic tank. Hydraulic loadings of the sand filters were equal to 82 mm/d. The mean discharge from sand columns, measured as the effluent volume collected during 10 minutes, decreased significantly over the experiment period from 34 cm3/min in August 2000 to 20 cm3/min in August 2001 at the same temperature of about 20 degrees C. First the columns clogged almost completely after 480 days in December 2001, however six columns had remained unclogged till the end of the experiment (March 2002). The temperature had a significant impact on hydraulic conductivity. A vertical distribution of accumulated mass and biomass was investigated in partly clogged sand. Microscopic survey of the clogging layer showed a presence of live micro-organisms, residuals of dead micro-organisms, particularly pieces of small animal armour and many fibres. These particles accelerated the accumulation of solids in the upper clogging layer. The study indicated that temperature impact on the filter hydraulic conductivity was more significant for biological activity, than for sewage viscosity.

Bacteriophage PRD1 batch experiments to study attachment, detachment and inactivation processes.

PubMed

Sadeghi, Gholamreza; Schijven, Jack F; Behrends, Thilo; Hassanizadeh, S Majid; van Genuchten, Martinus Th

2013-09-01

Knowledge of virus removal in subsurface environments is pivotal for assessing the risk of viral contamination of water resources and developing appropriate protection measures. Columns packed with sand are frequently used to quantify attachment, detachment and inactivation rates of viruses. Since column transport experiments are very laborious, a common alternative is to perform batch experiments where usually one or two measurements are done assuming equilibrium is reached. It is also possible to perform kinetic batch experiments. In that case, however, it is necessary to monitor changes in the concentration with time. This means that kinetic batch experiments will be almost as laborious as column experiments. Moreover, attachment and detachment rate coefficients derived from batch experiments may differ from those determined using column experiments. The aim of this study was to determine the utility of kinetic batch experiments and investigate the effects of different designs of the batch experiments on estimated attachment, detachment and inactivation rate coefficients. The experiments involved various combinations of container size, sand-water ratio, and mixing method (i.e., rolling or tumbling by pivoting the tubes around their horizontal or vertical axes, respectively). Batch experiments were conducted with clean quartz sand, water at pH 7 and ionic strength of 20 mM, and using the bacteriophage PRD1 as a model virus. Values of attachment, detachment and inactivation rate coefficients were found by fitting an analytical solution of the kinetic model equations to the data. Attachment rate coefficients were found to be systematically higher under tumbling than under rolling conditions because of better mixing and more efficient contact of phages with the surfaces of the sand grains. In both mixing methods, more sand in the container yielded higher attachment rate coefficients. A linear increase in the detachment rate coefficient was observed with increased solid-water ratio using tumbling method. Given the differences in the attachment rate coefficients, and assuming the same sticking efficiencies since chemical conditions of the batch and column experiments were the same, our results show that collision efficiencies of batch experiments are not the same as those of column experiments. Upscaling of the attachment rate from batch to column experiments hence requires proper understanding of the mixing conditions. Because batch experiments, in which the kinetics are monitored, are as laborious as column experiments, there seems to be no major advantage in performing batch instead of column experiments. Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental Evidence that Abrasion of Carbonate Sand is a Significant Source of Carbonate Mud

NASA Astrophysics Data System (ADS)

Trower, L.; Kivrak, L.; Lamb, M. P.; Fischer, W. W.

2017-12-01

Carbonate mud is a major sedimentary component of modern and ancient tropical carbonate environments, yet its enigmatic origin remains debated. Early views on the origin of carbonate mud considered the abrasion of carbonate sand during sediment transport as a possible mechanism. In recent decades, however, prevailing thought has generally settled on a binary explanation: 1) precipitation of aragonite needles within the water column, and 2) post-mortem dispersal of biological aragonite, in particular from algae, and perhaps aided by fish. To test these different hypotheses, we designed a model and a set of laboratory experiments to quantify the rates of mud production associated with sediment transport. We adapted a recent model of ooid abrasion rate to predict the rate of mud production by abrasion of carbonate sand as a function of grain size and sediment transport mode. This model predicts large mud production rates, ranging from 103 to 104 g CaCO3/m2/yr for typical grain sizes and transport conditions. These rate estimates are at least one order of magnitude more rapid than the 102 g CaCO3/m2/yr estimates for other mechanisms like algal biomineralization, indicating that abrasion could produce much larger mud fluxes per area as other mechanisms. We tested these estimates using wet abrasion mill experiments; these experiments generated mud through mechanical abrasion of both ooid and skeletal carbonate sand for grain sizes ranging from 250 µm to >1000 µm over a range of sediment transport modes. Experiments were run in artificial seawater, including a series of controls demonstrating that no mud was produced via homogenous nucleation and precipitation in the absence of sand. Our experimental rates match the model predictions well, although we observed small systematic differences in rates between abrasion ooid sand and skeletal carbonate sand that likely stems from innate differences in grain angularity. Electron microscopy of the experimental products revealed aragonite needles 1-3 µm in length identical to those described in carbonate mud from a range of modern environments. Our results suggest that abrasion during bed load and suspended load transport of carbonate sand, even over small areas, is likely a significant potential source of carbonate mud in both modern and ancient carbonate environments.

Morphodynamics of Planetary Deserts: A Laboratory Approach

NASA Astrophysics Data System (ADS)

Garcia, A.; Courrech Du Pont, S.; Rodriguez, S.

2014-12-01

Earth deserts show a rich variety of dune shapes from transverse to barchan, star and linear dunes depending on the history of wind regimes (strength and variability) and sand availability [1]. In desert, exposed to one wind direction, dunes perpendicular to the wind direction are found to be transverse or barchans, only sand availability plays a key role on their formation and evolution. However, the evolution time scale of such structures (several years) limits our investigation of their morphodynamics understanding. We use here, a laboratory experiment able to considerably reduce space and time scales by reproducing millimeter to centimeter subaqueous dunes by controlling environmental parameters such as type of wind (multi-winds, bimodal, quasi-bimodal or unidirectional wind) and amount of sediment [2,3]. This set up allows us to characterize more precisely the different modes of dune formation and long-term evolution, and to constrain the physics behind the morphogenesis and dynamics of dunes. Indeed, the formation, evolution and transition between the different dune modes are better understood and quantified thanks to a new setting experiment able to give a remote sediment source in continuous (closer to what happens in terrestrial desert): a sand distributor that controls the input sand flow. Firstly, in a one wind direction conditions, we managed to follow and quantify the growth of the instability of transverse dunes that break into barchans when the sand supply is low and reversely when the sand supply is higher, barchan fields evolve to bars dunes ending to form transverse. The next step will be to perform experiments under two winds conditions in order to better constrain the formation mode of linear dunes, depending also only on the input sand flux. Previous experiments shown that linear "finger" dunes can be triggered by the break of transverse dunes and then the elongating of one barchan's arm [4]. These studies can farther explain more precisely in different wind history and sand supply, these patterns state that should emerge and, by applying the relevant scale law, to apply this laboratory work to terrestrial and planetary (Mars and Titan) desert dynamics. [1] Bagnold R.A. (1941). [2] Hersen P. (2004). [3] Reffet E. (2010). [4] Courrech Du Pont S. et al. (2014).

Analog models of convergence and divergence: perspectives of the tectonics of the Middle East

NASA Astrophysics Data System (ADS)

Mart, Yossi

2010-05-01

Three series of analog models of convergence and divergence of tectonic plates illuminate the possible tectonic processes that shaped the lithology of the Middle East since the early Miocene. The Mid-East geographic province extends from the Ionian Sea to the Arabian Sea, and comprises the Hellenic subduction zone, the Aegean back-arc basin, the motion of Anatolia southwestwards, the oblique collision of Arabia and Iran along the Zagros suture, and the continental break-up of the Gulf of Aden and the Red Sea. The tectonic evolution of all these diverse domains started in the Miocene nearly contemporaneously, and modeling suggests that the convergence and divergence, though derived from unrelated processes, their tectonics is intertwined. Centrifuge models of the initiation of subduction show the correlation between early subduction and the opening of its back-arc basin (Mart et al., 2005). The models emphasize the significance of extensive seawards roll-back of the deformation front when friction between the thrust slabs is reduced, and consequently, the pull within the overthrust slab that leads to its structural extension. That extension produced the Aegean domain with its volcanism and the exposure of its core complex, as well as the westwards displacement of Anatolia along the North and East Anatolian Faults. Sand-box models of oblique subduction, namely the gradual shift from subduction to collision along the convergence front, showed orthogonal patterns of extension in distal parts of the underthrust slab (Bellahsen et al., 2002). It is suggested that the extensional domains deflected the propagation of Carlsberg Ridge to swing 1200 and penetrate the Gulf of Aden in the early Miocene. The structural differences between the Gulf of Aden and the Red Sea can be accounted for by the results of sand-box experiments in oblique rifting (Mart and Dauteuil, 2000). The models suggest that oblique rifting, where the deviation from the normal extension was ca. 50, would propagate continuously like wedge. However, where the deviation exceeds 150, the rifting takes place in two stages. At first a series of structural basins develops along an axial zone with no continuous boundary fault. Then the basins expand in their axial direction and, in time, interconect to form a rift with boundary faults that determine the down-thrown rift from its elevated margins. When these structures were welded into a mountain chain, it would be very complicated to determine the low friction from the high friction subduction, the temporal transition from subduction to collision, and the penetration of a spreading ridge into a tectonic convergence zone. The Middle East offers a unique view into the structural development of the continental lithosphere as it takes place. References: Bellahsen, N., Faccenna, C., Funiciello, F., Daniel J. M., Jolivet, L., 2003. Why did Arabia separate from Africa? Insights from 3-D laboratory experiments. Earth Planet. Sci. Lett., 216, 365-381. Mart, Y. and Dauteuil, O., 2000. Analogue experiments of propagation of oblique rifts. Tectonophysics, 316: 121-132. Mart, Y., Aharonov, E., Mulugeta, G., Ryan, W.B.F., Tentler, T., Goren, L., 2005. Analog modeling of the initiation of subduction. Geophys. J. Int., 160, 1081-1091.

Electric conductivity for laboratory and field monitoring of induced partial saturation (IPS) in sands

NASA Astrophysics Data System (ADS)

Kazemiroodsari, Hadi

Liquefaction is loss of shear strength in fully saturated loose sands caused by build-up of excess pore water pressure, during moderate to large earthquakes, leading to catastrophic failures of structures. Currently used liquefaction mitigation measures are often costly and cannot be applied at sites with existing structures. An innovative, practical, and cost effective liquefaction mitigation technique titled "Induced Partial Saturation" (IPS) was developed by researchers at Northeastern University. The IPS technique is based on injection of sodium percarbonate solution into fully saturated liquefaction susceptible sand. Sodium percarbonate dissolves in water and breaks down into sodium and carbonate ions and hydrogen peroxide which generates oxygen gas bubbles. Oxygen gas bubbles become trapped in sand pores and therefore decrease the degree of saturation of the sand, increase the compressibility of the soil, thus reduce its potential for liquefaction. The implementation of IPS required the development and validation of a monitoring and evaluation technique that would help ensure that the sands are indeed partially saturated. This dissertation focuses on this aspect of the IPS research. The monitoring system developed was based on using electric conductivity fundamentals and probes to detect the transport of chemical solution, calculate degree of saturation of sand, and determine the final zone of partial saturation created by IPS. To understand the fundamentals of electric conductivity, laboratory bench-top tests were conducted using electric conductivity probes and small specimens of Ottawa sand. Bench-top tests were used to study rate of generation of gas bubbles due to reaction of sodium percarbonate solution in sand, and to confirm a theory based on which degree of saturation were calculated. In addition to bench-top tests, electric conductivity probes were used in a relatively large sand specimen prepared in a specially manufactured glass tank. IPS was implemented in the prepared specimen to validate the numerical simulation model and explore the use of conductivity probes to detect the transport of chemical solution, estimate degree of saturation achieved due to injection of chemical solution, and evaluate final zone of partial saturation. The conductivity probe and the simulation results agreed well. To study the effect of IPS on liquefaction response of the sand specimen, IPS was implemented in a large (2-story high) sand specimen prepared in the laminar box of NEES Buffalo and then the specimen was subjected to harmonic shaking. Electric conductivity probes were used in the specimen treatment by controlling the duration and spacing of injection of the chemical solution, in monitoring the transport of chemical solution, in the estimation of zone of partial saturation achieved, and in the estimation of degree of saturation achieved due to implementation of IPS. The conductivity probes indicated partial saturation of the specimen. The shaking tests results confirmed the partial saturation state of the sand specimen. In addition, to the laboratory works, electric conductivity probes were used in field implementation of IPS in a pilot test at the Wildlife Liquefaction Array (WLA) of NEES UCSB site. The conductivity probes in the field test helped decide the optimum injection pressure, the injection tube spacing, and the degree of saturation that could be achieved in the field. The various laboratory and field tests confirmed that electric conductivity and the probes devised and used can be invaluable in the implementation of IPS, by providing information regarding transport of the chemical solution, the spacing of injection tubes, duration of injection, and the zone and degree of partial saturation caused by IPS.

The influence of wetting dynamics on the residual air distribution

NASA Astrophysics Data System (ADS)

Sacha, J.; Snehota, M.; Trtik, P.; Vontobel, P.

2016-12-01

The amount and distribution of the residual air during the infiltration into a porous soil system has a strong influence on the infiltration rate. Concurrently, the amount of residual air is dependent on the wetting dynamics. In the presented study, two experiments were conducted on the same sample. The first experiment was performed under the constant water level condition (CWL) and the second under the constant water flux condition (CWF) at the top of the sample. The sample that composed of coarse and medium coarse fractions of sand and fine porous ceramics was packed into the quartz glass columns of the inner diameter of 29 mm. The coarse sand represented a highly conductive region connected from the top to the bottom of the sample with the exception of three low (2-3 mm) separation layers made up of the medium coarse sand. Three discs of fine ceramic formed slow flow regions. Infiltration experiments were monitored by neutron radiography on two different beamlines to produce two-dimensional (2D) projections. The CWL experiment was monitored by NEUTRA station with an acquisition time of 16 seconds per projection and the CWF experiment was visualized at BOA station with an acquisition time of 0.25 seconds per projection. Both stations are located at the Paul Scherrer Institut, Switzerland. The acquired radiograms of the dry sample were subtracted from all subsequent radiograms to determine the water thickness in projections. From series of corrected radiograms taken at the different angles three-dimensional (3D) image was reconstructed for steady state part of the experiment CWL and for entire experiment CWF. Then the series of 3D images mapped the wetting of the porous system over the corresponding phase of infiltration process. The results showed a faster steady state infiltration rate during the CWL. In this case, the air was mostly pushed out from the sample by moving wetting front. On the contrary, during the CWF the water infiltrated into the fine ceramics first and then into the medium coarse sand attracted by stronger capillary forces in comparison to the coarse sand. Due to this effect a significant amount of air was trapped in preferential pathways, and consequently blocking the water flow. The presence of medium coarse sand regions had a crucial impact on the water flow and amount of air trapping.

Hydraulic experiment on formation mechanism of tsunami deposit and verification of sediment transport model for tsunamis

NASA Astrophysics Data System (ADS)

Yamamoto, A.; Takahashi, T.; Harada, K.; Sakuraba, M.; Nojima, K.

2017-12-01

An underestimation of the 2011 Tohoku tsunami caused serious damage in coastal area. Reconsideration for tsunami estimation needs knowledge of paleo tsunamis. The historical records of giant tsunamis are limited, because they had occurred infrequently. Tsunami deposits may include many of tsunami records and are expected to analyze paleo tsunamis. However, present research on tsunami deposits are not able to estimate the tsunami source and its magnitude. Furthermore, numerical models of tsunami and its sediment transport are also important. Takahashi et al. (1999) proposed a model of movable bed condition due to tsunamis, although it has some issues. Improvement of the model needs basic data on sediment transport and deposition. This study investigated the formation mechanism of tsunami deposit by hydraulic experiment using a two-dimensional water channel with slope. In a fixed bed condition experiment, velocity, water level and suspended load concentration were measured at many points. In a movable bed condition, effects of sand grains and bore wave on the deposit were examined. Yamamoto et al. (2016) showed deposition range varied with sand grain sizes. In addition, it is revealed that the range fluctuated by number of waves and wave period. The measurements of velocity and water level showed that flow was clearly different near shoreline and in run-up area. Large velocity by return flow was affected the amount of sand deposit near shoreline. When a cutoff wall was installed on the slope, the amount of sand deposit repeatedly increased and decreased. Especially, sand deposit increased where velocity decreased. Takahashi et al. (1999) adapted the proposed model into Kesennuma bay when the 1960 Chilean tsunami arrived, although the amount of sand transportation was underestimated. The cause of the underestimation is inferred that the velocity of this model was underestimated. A relationship between velocity and sediment transport has to be studied in detail, but observation of velocity in Kesennnuma bay had a low accuracy. On the other hand, this hydraulic experiment measured accurate velocity and sand deposition distribution of various condition. Based on these data, we tried more accurate verification of the model of Takahashi et al. (1999).

An RFID-Based Smart Nest Box: An Experimental Study of Laying Performance and Behavior of Individual Hens

PubMed Central

Chen, Yu-Xian

2018-01-01

This study designed a radio-frequency identification (RFID)-based Internet of Things (IoT) platform to create the core of a smart nest box. At the sensing level, we have deployed RFID-based sensors and egg detection sensors. A low-frequency RFID reader is installed in the bottom of the nest box and a foot ring RFID tag is worn on the leg of individual hens. The RFID-based sensors detect when a hen enters or exits the nest box. The egg-detection sensors are implemented with a resistance strain gauge pressure sensor, which weights the egg in the egg-collection tube. Thus, the smart nest box makes it possible to analyze the laying performance and behavior of individual hens. An evaluative experiment was performed using an enriched cage, a smart nest box, web camera, and monitoring console. The hens were allowed 14 days to become accustomed to the experimental environment before monitoring began. The proposed IoT platform makes it possible to analyze the egg yield of individual hens in real time, thereby enabling the replacement of hens with egg yield below a pre-defined level in order to meet the overall target egg yield rate. The results of this experiment demonstrate the efficacy of the proposed RFID-based smart nest box in monitoring the egg yield and laying behavior of individual hens. PMID:29538334

An RFID-Based Smart Nest Box: An Experimental Study of Laying Performance and Behavior of Individual Hens.

PubMed

Chien, Ying-Ren; Chen, Yu-Xian

2018-03-14

This study designed a radio-frequency identification (RFID)-based Internet of Things (IoT) platform to create the core of a smart nest box. At the sensing level, we have deployed RFID-based sensors and egg detection sensors. A low-frequency RFID reader is installed in the bottom of the nest box and a foot ring RFID tag is worn on the leg of individual hens. The RFID-based sensors detect when a hen enters or exits the nest box. The egg-detection sensors are implemented with a resistance strain gauge pressure sensor, which weights the egg in the egg-collection tube. Thus, the smart nest box makes it possible to analyze the laying performance and behavior of individual hens. An evaluative experiment was performed using an enriched cage, a smart nest box, web camera, and monitoring console. The hens were allowed 14 days to become accustomed to the experimental environment before monitoring began. The proposed IoT platform makes it possible to analyze the egg yield of individual hens in real time, thereby enabling the replacement of hens with egg yield below a pre-defined level in order to meet the overall target egg yield rate. The results of this experiment demonstrate the efficacy of the proposed RFID-based smart nest box in monitoring the egg yield and laying behavior of individual hens.

Children's Perception of Black and White Boxes and Bobo Dolls as a Reflection of How They Regard Their Own and Other's Racial Membership.

ERIC Educational Resources Information Center

Stabler, John R.; Johnson, Edward E.

Investigation of how children's responses to black and white objects reflect racial concepts is reported. One series of experiments asking Headstart children to guess which objects they liked or disliked were hidden in black or white boxes. Although white children guessed more often that positively evaluated objects were in white boxes, black…

Terraforming planet Dune: Climate-vegetation interactions on a sandy planet

NASA Astrophysics Data System (ADS)

Cresto Aleina, F.; Baudena, M.; D'Andrea, F.; Provenzale, A.

2012-04-01

The climate and the biosphere of planet Earth interact in multiple, complicated ways and on many spatial and temporal scales. Some of these processes can be studied with the help of simple mathematical models, as done for the effects of vegetation on albedo in desert areas and for the mechanisms by which terrestrial vegetation affects water fluxes in arid environments. Conceptual models of this kind do not attempt at providing quantitative descriptions of the climate-biosphere interaction, but rather to explore avenues and mechanisms which can play a role in the real system, providing inspiration for further research. In this work, we develop a simple conceptual box model in the spirit illustrated above, to explore whether and how vegetation affects the planetary hydrologic cycle. We imagine a planet with no oceans and whose surface is entirely covered with sand, quite similar to planet Dune of the science-fiction series by Frank Herbert (1965). We suppose that water is entirely in the sand, below the surface. Without vegetation, only evaporation takes place, affecting the upper sand layer for a maximum depth of a few cm. The amount of water that is evaporated in the atmosphere is relatively small, and not sufficient to trigger a full hydrologic cycle. The question is what happens to this planet when vegetation is introduced: the root depth can reach a meter or more, and plant transpiration can then transfer a much larger amount of water to the atmosphere. One may wonder whether the presence of vegetation is sufficient to trigger a hydrologic cycle with enough precipitation to sustain the vegetation itself and, if the answer is positive, what is the minimum vegetation cover that is required to maintain the cycle active. In more precise terms, we want to know whether the introduction of vegetation and of the evapotranspiration feedback allows for the existence of multiple equilibria (or solutions) in the soil-vegetation-atmosphere system. Although the box model introduced here is best formulated in terms of a hypothetical sandy planet, the results can be used to study the hydrologic cycle on wide continental regions of the Earth. On the other hand, our findings show how the definition of a habitable climate may also depend on surface characteristics, and in particular on biosphere and climate interactions.

Standard-resolution TOVS observations for the FIRE/SRB Wisconsin experiment region from October 9 through November 2, 1986

NASA Technical Reports Server (NTRS)

Whitlock, Charles H.; Lecroy, Stuart R.; Darnell, Wayne L.

1987-01-01

Maps and concise tables are presented which show TIROS Operational Vertical Sounder (TOVS) box centroid locations, box size, and vertical sounding products from the NOAA-6 and -9 satellites for the FIRE/SRB (First ISCCP Regional Experiment/Surface Radiation Budget) Wisconsin experiment region during October 9 through November 2, 1986. In addition to the operational standard products, relative reflectance is calculated and presented based on values from HIRS/2 Band 20 measurements.

Computer simulations and experimental study on crash box of automobile in low speed collision

NASA Astrophysics Data System (ADS)

Liu, Yanjie; Ding, Lin; Yan, Shengyuan; Yang, Yongsheng

2008-11-01

Based on the problems of energy-absorbing components in the automobile low speed collision process, according to crash box frontal crash test in low speed as the example, the simulation analysis of crash box impact process was carried out by Hyper Mesh and LS-DYNA. Each parameter on the influence modeling was analyzed by mathematics analytical solution and test comparison, which guaranteed that the model was accurate. Combination of experiment and simulation result had determined the weakness part of crash box structure crashworthiness aspect, and improvement method of crash box crashworthiness was discussed. Through numerical simulation of the impact process of automobile crash box, the obtained analysis result was used to optimize the design of crash box. It was helpful to improve the vehicles structure and decrease the collision accident loss at most. And it was also provided a useful method for the further research on the automobile collision.

The First Derivative of an Exponential Function with the "White Box/Black Box" Didactical Principle and Observations with GeoGebra

ERIC Educational Resources Information Center

Budinski, Natalija; Subramaniam, Stephanie

2013-01-01

This paper shows how GeoGebra--a dynamic mathematics software--can be used to experiment, visualize and connect various concepts such as function, first derivative, slope, and tangent line. Students were given an assignment to determine the first derivative of the exponential function that they solved while experimenting with GeoGebra. GeoGebra…

The role of size of input box, location of input box, input method and display size in Chinese handwriting performance and preference on mobile devices.

PubMed

Chen, Zhe; Rau, Pei-Luen Patrick

2017-03-01

This study presented two experiments on Chinese handwriting performance (time, accuracy, the number of protruding strokes and number of rewritings) and subjective ratings (mental workload, satisfaction, and preference) on mobile devices. Experiment 1 evaluated the effects of size of the input box, input method and display size on Chinese handwriting performance and preference. It was indicated that the optimal input sizes were 30.8 × 30.8 mm, 46.6 × 46.6 mm, 58.9 × 58.9 mm and 84.6 × 84.6 mm for devices with 3.5-inch, 5.5-inch, 7.0-inch and 9.7-inch display sizes, respectively. Experiment 2 proved the significant effects of location of the input box, input method and display size on Chinese handwriting performance and subjective ratings. It was suggested that the optimal location was central regardless of display size and input method. Copyright © 2016 Elsevier Ltd. All rights reserved.

Supercritical solvent extraction of oil sand bitumen

NASA Astrophysics Data System (ADS)

Imanbayev, Ye. I.; Ongarbayev, Ye. K.; Tileuberdi, Ye.; Mansurov, Z. A.; Golovko, A. K.; Rudyk, S.

2017-08-01

The supercritical solvent extraction of bitumen from oil sand studied with organic solvents. The experiments were performed in autoclave reactor at temperature above 255 °C and pressure 29 atm with stirring for 6 h. The reaction resulted in the formation of coke products with mineral part of oil sands. The remaining products separated into SARA fractions. The properties of the obtained products were studied. The supercritical solvent extraction significantly upgraded extracted natural bitumen.

Acoustic Scattering from Sand Dollars (Dendraster excentricus): Modeling as High Aspect Ratio Oblate Objects and Comparison to Experiment

DTIC Science & Technology

2008-09-01

2004), forward scattering and backscattering from a sand dollar test, a bivalve shell , and a machined aluminum disk of similar size were measured over a...Abstract Benthic shells can contribute greatly to the scattering variability of the ocean bottom, particularly at low grazing angles. Among the...effects of shell aggregates are increased scattering strength and potential subcritical angle penetration of the seafloor. Sand dollars (Dendraster

A direct comparison of U.S. Environmental Protection Agency's method 304B and batch tests for determining activated-sludge biodegradation rate constants for volatile organic compounds

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

Cano, M.L.; Wilcox, M.E.; Compernolle, R. van

Biodegradation rate constants for volatile organic compounds (VOCs) in activated-sludge systems are needed to quantify emissions. One current US environmental Protection Agency method for determining a biodegradation rate constant is Method 304B. In this approach, a specific activated-sludge unit is simulated by a continuous biological treatment system with a sealed headspace. Batch experiments, however, can be alternatives to Method 304B. Two of these batch methods are the batch test that uses oxygen addition (BOX) and the serum bottle test (SBT). In this study, Method 304B was directly compared to BOX and SBT experiments. A pilot-scale laboratory reactor was constructed tomore » serve as the Method 304B unit. Biomass from the unit was also used to conduct BOX and modified SBT experiments (modification involved use of a sealed draft-tube reactor with a headspace recirculation pump instead of a serum bottle) for 1,2-dichloroethane, diisopropyl ether, methyl tertiary butyl ether, and toluene. Three experimental runs--each consisting of one Method 304B experiment, one BOX experiment, and one modified SBT experiment--were completed. The BOX and SBT data for each run were analyzed using a Monod model, and best-fit biodegradation kinetic parameters were determined for each experiment, including a first-order biodegradation rate constant (K{sub 1}). Experimental results suggest that for readily biodegradable VOCs the two batch techniques can provide improved means of determining biodegradation rate constants compared with Method 304B. In particular, these batch techniques avoid the Method 304B problem associated with steady-state effluent concentrations below analytical detection limits. However, experimental results also suggest that the two batch techniques should not be used to determine biodegradation rate constants for slowly degraded VOCs (i.e., K{sub 1} {lt} 0.1 L/g VSS-h).« less

Excess Foundry Sand Characterization and Experimental Investigation in Controlled Low-Strength Material and Hot-Mixing Asphalt

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

Tikalsky, Paul J.; Bahia, Hussain U.; Deng, An

2004-10-15

This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: a statistically sound evaluation of the characterization of foundry sand, a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis and leachate characterization. Notmore » limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at Nini, Ndes, and Nmax. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.« less

Excess Foundry Sand Characterization and Experimental Investigation in Controlled Low-Strength Material and Hot-Mixing Asphalt

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

Pauul J. Tikalsky

2004-10-31

This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: (1) a statistically sound evaluation of the characterization of foundry sand, (2) a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and (3) the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis andmore » leachate characterization. Not limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at N{sub ini}, N{sub des}, and N{sub max}. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.« less

Tensile strength and the mining of black holes.

PubMed

Brown, Adam R

2013-11-22

There are a number of important thought experiments that involve raising and lowering boxes full of radiation in the vicinity of black hole horizons. This Letter looks at the limitations placed on these thought experiments by the null energy condition, which imposes a fundamental bound on the tensile-strength-to-weight ratio of the materials involved, makes it impossible to build a box near the horizon that is wider than a single wavelength of the Hawking quanta, and puts a severe constraint on the operation of "space elevators" near black holes. In particular, it is shown that proposals for mining black holes by lowering boxes near the horizon, collecting some Hawking radiation, and dragging it out to infinity cannot proceed nearly as rapidly as has previously been claimed. As a consequence of this limitation, the boxes and all the moving parts are superfluous and black holes can be destroyed equally rapidly by threading the horizon with strings.

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

Warpinski, N.R.

Stimulation experiments conducted in anisotropic, naturally fractured, tight, lenticular gas sandstones have shown the existence of a dual-leakoff phenomenon. Below a threshold pressure, the leakoff coefficient is very low and fluids are very efficient. Above the threshold, leakoff increased by a factor of 50, slurries dehydrate rapidly, and screenouts occur in minutes. The leakoff has been shown to be controllable to some extent with 100-mesh sand. Results of three stimulation experiments are presented, including a treatment that screened out, a minifracture experiment that showed the effectiveness of 100-mesh sand, and a final successful stimulation.

Deflection monitoring for a box girder based on a modified conjugate beam method

NASA Astrophysics Data System (ADS)

Chen, Shi-Zhi; Wu, Gang; Xing, Tuo

2017-08-01

After several years of operation, a box girder bridge would commonly experience excessive deflection, which endangers the bridge’s life span as well as the safety of vehicles travelling on it. In order to avoid potential risks, it is essential to constantly monitor the defection of box girders. However, currently, the direct deflection monitoring methods are limited by the complicated environments beneath the bridges, such as rivers or other traffic lanes, which severely impede the layouts of the sensors. The other indirect deflection monitoring methods mostly do not thoroughly consider the inherent shear lag effect and shear deformation in the box girder, resulting in a rather large error. Under these circumstances, a deflection monitoring method suiting box girders is proposed in this article, based on the conjugate beam method and distributed long-gauge fibre Bragg grating (FBG) sensor. A lab experiment was conducted to verify the reliability and feasibility of this method under practical application. Further, the serviceability under different span-depth ratios and web thicknesses was examined through a finite element model.

Children's thinking about their own and others' regret and relief.

PubMed

Weisberg, Daniel P; Beck, Sarah R

2010-01-01

In two experiments using a decision-making game, we investigated children's thinking about regret and relief. In Experiment 1 (N=43, 31 children [5 years 4 months to 8 years 2 months of age] and 12 adults), participants chose between two boxes containing different numbers of stickers. They rated their happiness before learning that the other box contained more (regret) or fewer (relief) stickers. They rerated their chosen box with the counterfactual knowledge. The experience of regret was evident at 5 years of age, and the experience of relief was evident at 7 years of age. In Experiment 2 (N=69, 53 children [5 years 3 months to 6 years 11 months of age] and 16 adults), participants either played the game (self condition) or watched another play the game (other condition). Children in the self condition confirmed the results from Experiment 1. We found no evidence that children up to 7 years of age were able to predict others' regret and relief, a finding that suggests differing developmental trajectories between experiencing and understanding others' regret and relief. Copyright 2010 Elsevier Inc. All rights reserved.

Study on sand particles creep model and open pit mine landslide mechanism caused by sand fatigue liquefaction

NASA Astrophysics Data System (ADS)

Du, Dong-Ning; Wang, Lai-Gui; Zhang, Xiang-Dong; Zhang, Shu-Kun

2017-06-01

The sand particles in the sand - rock composite slope of the open pit mine occurs creep deformation and fatigue liquefaction under the action of vehicle load vibration and hydraulic gradient, which causes landslide geological disasters and it destroys the surface environment. To reveal the mechanism, a mechanics model based on the model considering the soil structural change with a new “plastic hinge” element is developed, to improve its constitutive and creep curve equations. Data from sand creep experiments are used to identify the parameters in the model and to validate the model. The results show that the mechanical model can describe the rotation progress between the sand particles, disclose the negative acceleration creep deformation stage during the third phase, and require fewer parameters while maintaining accuracy. It provides a new creep model considering rotation to analyze sand creep mechanism, which provides a theoretical basis for revealing the open pit mine landslide mechanism induced by creep deformation and fatigue liquefaction of sandy soil.

Miles Discusses Skylab Experiment With NASA Personnel

NASA Technical Reports Server (NTRS)

1972-01-01

Lexington, Massachusetts high school student, Judith Miles, discusses her proposed Skylab experiment with engineers and scientists during a design review of the experiment equipment. At left is Ron Pavlue of Kennedy Space Flight Center (KSC), holding a box is Keith Demorest of Marshall Space Flight Center (MSFC). Right of Miles is Dr. Raymond Gause, also of MSFC, who is Miles' scientific advisor. In her experiment, called the 'Web Formation in Zero Gravity', spiders were released into a box and their actions recorded to determine how well they adapt to the absence of gravity. Spiders are known to adapt quickly to other changes in the environment but nothing was known of their ability to adapt to weightlessness. At the same time spiders were weaving webs in Earth orbit, similar spiders were spinning webs in identical boxes on Earth under full gravity conditions. Miles was among the 25 winners of a contest in which some 3,500 high school students proposed experiments for the following year's Skylab mission. Of the 25 students, 6 did not see their experiments conducted on Skylab because the experiments were not compatible with Skylab hardware and timelines. Of the 19 remaining, 11 experiments required the manufacture of equipment.

Transport of Lactate-modified Nanoscale Iron Particles in Porous Media

NASA Astrophysics Data System (ADS)

Reddy, K. R.

2012-12-01

Nanoscale iron particles (NIP) have recently shown to be effective for dehalogenation of recalcitrant organic contaminants such as pentachlorphenol (PCP) and dinitrotoluene (DNT) in the environment. However, effective transport of NIP into the contaminated subsurface zones is crucial for the success of in-situ remediation. Previous studies showed that the transport of NIP in soils is very limited and surface-modification of NIP is required to achieve adequate transport. This paper investigates the transport of NIP and lactate-modified NIP (LMNIP) through four different porous media (sands with different particle size and distribution). A series of laboratory column experiments was conducted to quantify the transport of NIP and LMNIP at two different slurry concentrations of 1 g/L and 4 g/L under two different flow velcoities. NIP used in this study possessed magentic properties, thus a magnetic susceptibility sensor system was used to monitor the changes in magnetic susceptibility (MS) along the length of the column at different times during the experiments. At the end of testing, the distribution of total Fe in the sand column was measured. Results showed a linear correlation between the Fe concentration and MS and it was used to assess the transient transport of NIP and LMNIP in the sand columns. Results showed that LMNIP transported better than bare NIP and higher concentration of 4 g/L LMNIP exhibited unform and greater transport compared to other tested conditions. Transport of NIP increased in the order from fine Ottawa sand > medium field sand > coarse field sand > coarse Ottawa sand. Filtration theory and advective-dispersion equation with reaction were applied to capture the transport response of NIP and LMNIP in the sand columns.

Granular Mechanics and Surface Systems Lab

NASA Technical Reports Server (NTRS)

Randle, Leah

2007-01-01

The cratering of sand under gas jets is observed to further understanding of soil in hopes to further understand lunar soil. Lunar soil is important to understand because it is causing problems with the materials taken into space including the shuttle. Lunar soil is not rounded like beach sand. Lunar soil is sharp like little particles of glass, and some times when blown they can hook on to one another and become bigger particles. The experiments are designed to help to understand some of the basic physics in how the shuttle jets will interact with lunar soil and how to control the lunar soil. These experiments investigate the diameter of the gas jet and the size of the sand grains to determine how these parameters affect the erosion rate and the cratering processes. Therefore, the experiments preformed will point out what is dependent and what is independent.

Genome-wide identification, characterisation and expression analysis of the MADS-box gene family in Prunus mume.

PubMed

Xu, Zongda; Zhang, Qixiang; Sun, Lidan; Du, Dongliang; Cheng, Tangren; Pan, Huitang; Yang, Weiru; Wang, Jia

2014-10-01

MADS-box genes encode transcription factors that play crucial roles in plant development, especially in flower and fruit development. To gain insight into this gene family in Prunus mume, an important ornamental and fruit plant in East Asia, and to elucidate their roles in flower organ determination and fruit development, we performed a genome-wide identification, characterisation and expression analysis of MADS-box genes in this Rosaceae tree. In this study, 80 MADS-box genes were identified in P. mume and categorised into MIKC, Mα, Mβ, Mγ and Mδ groups based on gene structures and phylogenetic relationships. The MIKC group could be further classified into 12 subfamilies. The FLC subfamily was absent in P. mume and the six tandemly arranged DAM genes might experience a species-specific evolution process in P. mume. The MADS-box gene family might experience an evolution process from MIKC genes to Mδ genes to Mα, Mβ and Mγ genes. The expression analysis suggests that P. mume MADS-box genes have diverse functions in P. mume development and the functions of duplicated genes diverged after the duplication events. In addition to its involvement in the development of female gametophytes, type I genes also play roles in male gametophytes development. In conclusion, this study adds to our understanding of the roles that the MADS-box genes played in flower and fruit development and lays a foundation for selecting candidate genes for functional studies in P. mume and other species. Furthermore, this study also provides a basis to study the evolution of the MADS-box family.

A Statistics-Based Cracking Criterion of Resin-Bonded Silica Sand for Casting Process Simulation

NASA Astrophysics Data System (ADS)

Wang, Huimin; Lu, Yan; Ripplinger, Keith; Detwiler, Duane; Luo, Alan A.

2017-02-01

Cracking of sand molds/cores can result in many casting defects such as veining. A robust cracking criterion is needed in casting process simulation for predicting/controlling such defects. A cracking probability map, relating to fracture stress and effective volume, was proposed for resin-bonded silica sand based on Weibull statistics. Three-point bending test results of sand samples were used to generate the cracking map and set up a safety line for cracking criterion. Tensile test results confirmed the accuracy of the safety line for cracking prediction. A laboratory casting experiment was designed and carried out to predict cracking of a cup mold during aluminum casting. The stress-strain behavior and the effective volume of the cup molds were calculated using a finite element analysis code ProCAST®. Furthermore, an energy dispersive spectroscopy fractographic examination of the sand samples confirmed the binder cracking in resin-bonded silica sand.

An experimental study on dynamic response for MICP strengthening liquefiable sands

NASA Astrophysics Data System (ADS)

Han, Zhiguang; Cheng, Xiaohui; Ma, Qiang

2016-12-01

The technology of bio-grouting is a new technique for soft ground improvement. Many researchers have carried out a large number of experiments and study on this topic. However, few studies have been carried out on the dynamic response of solidified sand samples, such reducing liquefaction in sand. To study this characteristic of microbial-strengthened liquefiable sandy foundation, a microorganism formula and grouting scheme is applied. After grouting, the solidified samples are tested via dynamic triaxial testing to examine the cyclic performance of solidified sand samples. The results indicate that the solidified sand samples with various strengths can be obtained to meet different engineering requirements, the use of bacteria solution and nutritive salt is reduced, and solidified time is shortened to 1-2 days. Most importantly, in the study of the dynamic response, it is found that the MICP grouting scheme is effective in improving liquefiable sand characteristic, such as liquefaction resistance.

Quantum transport in coupled Majorana box systems

NASA Astrophysics Data System (ADS)

Gau, Matthias; Plugge, Stephan; Egger, Reinhold

2018-05-01

We present a theoretical analysis of low-energy quantum transport in coupled Majorana box devices. A single Majorana box represents a Coulomb-blockaded mesoscopic superconductor proximitizing two or more long topological nanowires. The box thus harbors at least four Majorana zero modes (MZMs). Setups with several Majorana boxes, where MZMs on different boxes are tunnel coupled via short nanowire segments, are key ingredients to recent Majorana qubit and code network proposals. We construct and study the low-energy theory for multiterminal junctions with normal leads connected to the coupled box device by lead-MZM tunnel contacts. Transport experiments in such setups can test the nonlocality of Majorana-based systems and the integrity of the underlying Majorana qubits. For a single box, we recover the previously described topological Kondo effect which can be captured by a purely bosonic theory. For several coupled boxes, however, nonconserved local fermion parities require the inclusion of additional local sets of Pauli operators. We present a renormalization group analysis and develop a nonperturbative strong-coupling approach to quantum transport in such systems. Our findings are illustrated for several examples, including a loop qubit device and different two-box setups.

Non-pumping reactive wells filled with mixing nano and micro zero-valent iron for nitrate removal from groundwater: Vertical, horizontal, and slanted wells

NASA Astrophysics Data System (ADS)

Hosseini, Seiyed Mossa; Tosco, Tiziana; Ataie-Ashtiani, Behzad; Simmons, Craig T.

2018-03-01

Non-pumping reactive wells (NPRWs) filled by zero-valent iron (ZVI) can be utilized for the remediation of groundwater contamination of deep aquifers. The efficiency of NPRWs mainly depends on the hydraulic contact time (HCT) of the pollutant with the reactive materials, the extent of the well capture zone (Wcz), and the relative hydraulic conductivity of aquifer and reactive material (Kr). We investigated nitrate removal from groundwater using NPRWs filled by ZVI (in nano and micro scales) and examined the effect of NPRWs orientations (i.e. vertical, slanted, and horizontal) on HCT and Wcz. The dependence of HCT on Wcz for different Kr values was derived theoretically for a homogeneous and isotropic aquifer, and verified using particle tracking simulations performed using the semi-analytical particle tracking and pathlines model (PMPATH). Nine batch experiments were then performed to investigate the impact of mixed nano-ZVI, NZVI (0 to 2 g l-1) and micro-ZVI, MZVI (0 to 4 g l-1) on the nitrate removal rate (with initial NO3-=132 mg l-1). The NPRWs system was tested in a bench-scale sand medium (60 cm length × 40 cm width × 25 cm height) for three orientations of NPRWs (vertical, horizontal, and slanted with inclination angle of 45°). A mixture of nano/micro ZVI, was used, applying constant conditions of pore water velocity (0.024 mm s-1) and initial nitrate concentration (128 mg l-1) for five pore volumes. The results of the batch tests showed that mixing nano and micro Fe0 outperforms these individual materials in nitrate removal rates. The final products of nitrate degradation in both batch and bench-scale experiments were NO2-, NH4+, and N2(gas). The results of sand-box experiments indicated that the slanted NPRWs have a higher nitrate reduction rate (57%) in comparison with vertical (38%) and horizontal (41%) configurations. The results also demonstrated that three factors have pivotal roles in expected HCT and Wcz, namely the contrast between the hydraulic conductivity of aquifer and reactive materials within the wells, the mass of Fe0 in the NPRWs, and the orientation of NPRWs adopted. A trade-off between these factors should be considered to increase the efficiency of remediation using the NPRWs system.

Trial-Run of a Junction-Box Attachment Test for Use in Photovoltaic Module Qualification: Preprint

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

Miller, D. C.; Deibert, S. L.; Wohlgemuth, J. H.

Engineering robust adhesion of the junction box (j-box) is a hurdle typically encountered by photovoltaic module manufacturers during product development and manufacturing process control. There are historical incidences of adverse effects (e.g., fires) caused when the j-box/adhesive/module system has failed in the field. The addition of a weight to the j-box during the 'damp-heat,' 'thermal-cycle,' or 'creep' tests within the IEC qualification protocol is proposed to verify the basic robustness of the adhesion system. The details of the proposed test are described, in addition to a trial-run of the test procedure. The described experiments examine four moisture-cured silicones, four foammore » tapes, and a hot-melt adhesive used in conjunction with glass, KPE, THV, and TPE substrates. For the purpose of validating the experiment, j-boxes were adhered to a substrate, loaded with a prescribed weight, and then subjected to aging. The replicate mock-modules were aged in an environmental chamber (at 85 degrees C/85% relative humidity for 1000 hours; then 100 degrees C/<10% relative humidity for 200 hours) or fielded in Golden (CO), Miami (FL), and Phoenix (AZ) for one year. Attachment strength tests, including pluck and shear test geometries, were also performed on smaller component specimens.« less

Trial Run of a Junction-Box Attachment Test for Use in Photovoltaic Module Qualification (Presentation)

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

Miller, D.; Deibert, S.; Wohlgemuth, J.

Engineering robust adhesion of the junction-box (j-box) is a hurdle typically encountered by photovoltaic (PV) module manufacturers during product development and manufacturing process control. There are historical incidences of adverse effects (e.g., fires), caused when the j-box/adhesive/module system has failed in the field. The addition of a weight to the j-box during the 'damp-heat', 'thermal-cycle', or 'creep' tests within the IEC qualification protocol is proposed to verify the basic robustness of the adhesion system. The details of the proposed test are described, in addition to a trial run of the test procedure. The described experiments examine 4 moisture-cured silicones, 4more » foam tapes, and a hot-melt adhesive used in conjunction with glass, KPE, THV, and TPE substrates. For the purpose of validating the experiment, j-boxes were adhered to a substrate, loaded with a prescribed weight, and then subjected to aging. The replicate mock-modules were aged in an environmental chamber (at 85 deg C/85% relative humidity for 1000 hours; then 100 degrees C/<10% relative humidity for 200 hours) or fielded in Golden, Miami, and Phoenix for 1 year. Attachment strength tests, including pluck and shear test geometries, were also performed on smaller component specimens.« less

The influence of viewing conditions on radiological diagnosis of periapical inflammation.

PubMed

Patel, N; Rushton, V E; Macfarlane, T V; Horner, K

2000-07-08

To determine the effect of viewing conditions upon diagnosis of early periapical inflammatory pathosis on intra-oral radiographs, and to examine the effect of observer experience upon diagnostic performance in this task. 50 observers examined 18 periapical radiographs using three different viewing conditions (room lighting; viewing box; viewing box with x2 magnification and masking). Their diagnoses were compared with an 'expert' diagnosis provided by repeated viewings of the films by two dental radiologists. Sensitivities and specificities were determined. When 'ideal' viewing conditions were used, optimal sensitivity (78%) and specificity (78%) were obtained. Use of a viewing box was associated with significantly higher specificity than the use of room lighting (P = 0.0016). Use of masking and x2 magnification was associated with significantly higher sensitivity than a viewing box alone (P = 0.004). There were few significant differences in diagnostic performance between observers, but qualified dental staff had significantly higher specificities than 4th year (P = 0.01) and 5th year (P = 0.01) students when a viewing box was used alone. This study on early periapical inflammatory pathosis gives support to guidelines which recommend the use of a viewing box, x2 magnification and masking for interpreting intra-oral radiographs. It also suggests that observer experience may influence interpretation of early periapical pathosis.

Response of Soybean to Heterodera glycines Races 1 and 2 in Different Soil Types.

PubMed

Schmitt, D P; Ferris, H; Barker, K R

1987-04-01

Experiments were conducted for 3 years at four locations and 1 year with six soil types at a common location in North Carolina to determine damage and control-cost functions for Heterodera glycines races 1 and 2 on soybean. In the experiments on native loamy sand and sandy soils, tolerance limits for initial population densities were 0 or very low, whereas in a muck, the tolerance limit was 315 eggs/500 cm(3) soil. The aggressive race 2 was more damaging than race 1 in Lakeland sand and Norfolk loamy sand. The crop response was not different between races in the Appling sandy clay loam and Belhaven muck. Soybean yield responses to H. glycines were linear in six soil types in microplots at a common site. The amount of damage varied among these soil types, with lowest yields in the muck because of severe drought stress in this soil. An exponential function adequately described soybean yield response relative to nematode control with increasing rates of aldicarb in Norfolk loamy sand. Treatment with aldicarb in the Lakeland sand decreased the effective egg population of H. glycines but had only a minor effect in the muck.

Simple stochastic cellular automaton model for starved beds and implications about formation of sand topographic features in terms of sand flux

NASA Astrophysics Data System (ADS)

Endo, Noritaka

2016-12-01

A simple stochastic cellular automaton model is proposed for simulating bedload transport, especially for cases with a low transport rate and where available sediments are very sparse on substrates in a subaqueous system. Numerical simulations show that the bed type changes from sheet flow through sand patches to ripples as the amount of sand increases; this is consistent with observations in flume experiments and in the field. Without changes in external conditions, the sand flux calculated for a given amount of sand decreases over time as bedforms develop from a flat bed. This appears to be inconsistent with the general understanding that sand flux remains unchanged under the constant-fluid condition, but it is consistent with the previous experimental data. For areas of low sand abundance, the sand flux versus sand amount (flux-density relation) in the simulation shows a single peak with an abrupt decrease, followed by a long tail; this is very similar to the flux-density relation seen in automobile traffic flow. This pattern (the relation between segments of the curve and the corresponding bed states) suggests that sand sheets, sand patches, and sand ripples correspond respectively to the free-flow phase, congested phase, and jam phase of traffic flows. This implies that sand topographic features on starved beds are determined by the degree of interference between sand particles. Although the present study deals with simple cases only, this can provide a simplified but effective modeling of the more complicated sediment transport processes controlled by interference due to contact between grains, such as the pulsatory migration of grain-size bimodal mixtures with repetition of clustering and scattering.

Behavior of Windblown Sand on Mars: Results From Single-Particle Experiments

NASA Astrophysics Data System (ADS)

Marshall, J. R.; Borucki, J.; Sagan, C.

1996-03-01

Experiments are investigating the behavior of individual sand grains in the high-energy martian aeolian regime. Energy partitioning during impact of a saltating grain determines grain longevity, but it also influences the way in which the bed becomes mobilized by reptation. When single grains of sand are fired into loose beds, the bed can absorb up to 90% of the impact energy by momentum transfer to other grains; it has been discovered that the impacting grains cause circular craters even at low impact angles. Hundreds of grains can be splashed by a single high-velocity (100 m/s) impact causing more bed disturbance through reptation than previously thought. The research is supported by NASA's PG & G Program.

Physiological and subjective measures of workload when shovelling with a conventional and two-handled ('levered') shovel.

PubMed

Bridger, R S; Cabion, N; Goedecke, J; Rickard, S; Schabort, E; Westgarth-Taylor, C; Lambert, M I

1997-11-01

Previous studies have suggested that the two-handled (levered) shovel is advantageous over the conventional spade from a biomechanical point of view. The aim of this experiment was to determine whether less energy was consumed while shovelling a load of sand with this shovel compared to a conventional tool. Accordingly, an experiment was designed in which subjects (n = 10) shovelled 1815 kg sand under laboratory conditions using either a conventional or a levered shovel. Heart rate and oxygen consumption were measured continuously during the trial and subjective data on perceived exertion, general fatigue and body discomfort were recorded after the trial. Although total energy expenditure was similar under both conditions (120 +/- 20 and 125 +/- 25 kcal; conventional versus two-handled spade), average heart rate was 4% higher when the two-handled shovel was used (p < 0.05). In addition, the mass of sand per scoop was 4% less with the two-handled shovel (p < 0.05). In conclusion, subjects used similar energy expenditure to shovel 1815 kg sand with the conventional shovel and the two-handled tool despite lower mass of sand per scoop with the latter. This can be explained by the fact that the increased mass of the additional handle compensated for the lower mass of sand per scoop. The higher average heart rate while shovelling with the two-handled shovel can be explained by the more erect posture.

Double invisible displacement understanding in orangutans: testing in non-locomotor and locomotor space.

PubMed

Mallavarapu, Suma; Stoinski, Tara S; Perdue, Bonnie M; Maple, Terry L

2014-10-01

The nonadjacent double invisible displacement task has been used to test for the ability of different species to mentally represent the unperceived trajectory of an object. The task typically requires three occluders/boxes in a linear array and involves hiding an object in one of two nonadjacent boxes visited in succession. Previous research indicates that 19-, 26-, and 30-month-old children and various nonhuman species cannot solve these displacements. It has been hypothesized that this is because individuals are unable to inhibit searching in the unbaited center box that was never visited by the experimenter. It has been suggested that presenting the task in a large-scale locomotor space might allow individuals to overcome this inhibition problem. In the present study, we tested orangutans on adjacent and nonadjacent double invisible displacements with the traditional setup (experiment 1) and in locomotor space with boxes placed 1.22 m apart (experiment 2). In both experiments, subjects were able to solve adjacent, but not nonadjacent, trials. The failure on nonadjacent trials appeared to be because of an inability to inhibit sequential search on the second choice as well as because of a large number of first-choice errors (directly choosing an incorrect box). The current results support previous findings that orangutans exhibit some constraints when representing the invisible trajectory of objects.

Skylab

NASA Image and Video Library

1972-08-21

Lexington, Massachusetts high school student, Judith Miles, discusses her proposed Skylab experiment with engineers and scientists during a design review of the experiment equipment. At left is Ron Pavlue of Kennedy Space Flight Center (KSC), holding a box is Keith Demorest of Marshall Space Flight Center (MSFC). Right of Miles is Dr. Raymond Gause, also of MSFC, who is Miles’ scientific advisor. In her experiment, called the “Web Formation in Zero Gravity”, spiders were released into a box and their actions recorded to determine how well they adapt to the absence of gravity. Spiders are known to adapt quickly to other changes in the environment but nothing was known of their ability to adapt to weightlessness. At the same time spiders were weaving webs in Earth orbit, similar spiders were spinning webs in identical boxes on Earth under full gravity conditions. Miles was among the 25 winners of a contest in which some 3,500 high school students proposed experiments for the following year’s Skylab mission. Of the 25 students, 6 did not see their experiments conducted on Skylab because the experiments were not compatible with Skylab hardware and timelines. Of the 19 remaining, 11 experiments required the manufacture of equipment.

Soil pollution by petroleum products, III. Kerosene stability in soil columns as affected by volatilization

NASA Astrophysics Data System (ADS)

Galin, Ts.; Gerstl, Z.; Yaron, B.

1990-05-01

The stability of kerosene in soils as affected by volatization was determined in a laboratory column experiment by following the losses in the total concentration and the change in composition of the residuals in a dune sand, a loamy sand, and a silty loam soil during a 50-day period. Seven major compounds ranging between C 9 and C 15 were selected from a large variety of hydrocarbons forming kerosene and their presence in the remaining petroleum product was determined. The change in composition of kerosene during the experimental period was determined by gas chromatography and related to the seven major compounds selected. The experimental conditions — air-dairy soil and no subsequent addition of water—excluded both biodegradative and leaching. losses. The losses of kerosene in air-dried soil columns during the 50-day experimental period and the changes in the composition of the remaining residues due to volatilization are reported. The volatilization of all the components determined was greater from the dune sand and loamy sand soils than from the silty loam soil. It was assumed that the reason for this behavior was that the dune sand and the loamy sand soils contain a greater proportion of large pores (>4.5 μm) than the silty loam soil, even though the total porosity of the loamy sand and the silty loam is similar. In all the soils in the experiment, the components with a high carbon number formed the main fraction of the kerosene residues after 50 days of incubation.

Effect of Grain Scale Properties on Bulk Deformation of Granular Deposits Due to High Speed Projectile Impact

DTIC Science & Technology

2013-04-08

Details of 1D compression test Material: Florida coastal sand Mean diameter: 0.37(mm) Vessel: Stainless steel Vessel inner diameter 6.0(mm... turned out that the projectile deceleration behavior observed in the experiment is a consequence of the complicated compression behavior of sand...applicability of the proposed EOS into high-speed projectile impact experiment. It turned out that the projectile deceleration behavior observed in the

Numerical analysis of experiments on the generation of shock waves in aluminium under indirect (X-ray) action on the Iskra-5 facility

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

Bondarenko, S V; Dolgoleva, G V; Novikova, E A

The dynamics of laser and X-ray radiation fields in experiments with cylindrical converter boxes (illuminators), which had earlier been carried out on the Iskra-5 laser facility (the second harmonic of iodine laser radiation, {lambda} = 0.66 {mu}m) was investigated in a sector approximation using the SND-LIRA numerical technique. In these experiments, the X-ray radiation temperature in the box was determined by measuring the velocity of the shock wave generated in the sample under investigation, which was located at the end of the cylindrical illuminator. Through simulations were made using the SND-LIRA code, which took into account the absorption of lasermore » driver radiation at the box walls, the production of quasithermal radiation, as well as the formation and propagation of the shock wave in the sample under investigation. An analysis of the experiments permits determining the electron thermal flux limiter f: for f = 0.03 it is possible to match the experimental scaling data for X-ray in-box radiation temperature to the data of our simulations. The shock velocities obtained from the simulations are also consistent with experimental data. In particular, in the experiment with six laser beams (and a laser energy E{sub L} = 1380 J introduced into the box) the velocity of the shock front (determined from the position of a laser mark) after passage through a 50-{mu}m thick base aluminium layer was equal to 35{+-}1.6 km s{sup -1}, and in simulations to 36 km s{sup -1}. In the experiment with four laser beams (for E{sub L} = 850 J) the shock velocity (measured from the difference of transit times through the base aluminium layer and an additional thin aluminium platelet) was equal to 30{+-}3.6 km s{sup -1}, and in simulations to 30 km s{sup -1}. (interaction of laser radiation with matter)« less

Cryogenic distribution box for Fermi National Accelerator Laboratory

NASA Astrophysics Data System (ADS)

Svehla, M. R.; Bonnema, E. C.; Cunningham, E. K.

2017-12-01

Meyer Tool & Mfg., Inc (Meyer Tool) of Oak Lawn, Illinois is manufacturing a cryogenic distribution box for Fermi National Accelerator Laboratory (FNAL). The distribution box will be used for the Muon-to-electron conversion (Mu2e) experiment. The box includes twenty-seven cryogenic valves, two heat exchangers, a thermal shield, and an internal nitrogen separator vessel, all contained within a six-foot diameter ASME coded vacuum vessel. This paper discusses the design and manufacturing processes that were implemented to meet the unique fabrication requirements of this distribution box. Design and manufacturing features discussed include: 1) Thermal strap design and fabrication, 2) Evolution of piping connections to heat exchangers, 3) Nitrogen phase separator design, 4) ASME code design of vacuum vessel, and 5) Cryogenic valve installation.

The Radish Party

ERIC Educational Resources Information Center

Piotrowski, Jeff; Mildenstein, Tammy; Dungan, Kathy; Brewer, Carol

2007-01-01

The Radish Party inquiry is designed to teach the importance and relevance of soil organic matter to young students. In this investigation, students grow radishes in three different kinds of soils: sand, sand plus nutrients, and potting soil (soil that includes organic matter). The experience described here was conducted with first- and…

A Scientific World in a Grain of Sand

ERIC Educational Resources Information Center

Clary, Renee; Wandersee, James

2011-01-01

Students investigate local sand samples on a shoestring budget. This investigation reveals a fascinating Earth history that can address various interdisciplinary scientific topics, provide rich inquiry experiences, and move beyond the science classroom to integrate history, culture, and art. (Contains 3 figures and 14 online resources.)

Retention and remobilization of stabilized silver nanoparticles in an undisturbed loamy sand soil

USDA-ARS?s Scientific Manuscript database

Column experiments were conducted with undisturbed loamy sand soil under unsaturated conditions (around 90% saturation degree) to investigate the retention of surfactant stabilized silver nanoparticles (AgNPs) with various input concentration (Co), flow velocity, and ionic strength (IS), and the rem...

Lab-in-a-box @ school: Exiting hands-on experiments in soft matter physics

NASA Astrophysics Data System (ADS)

Jacobs, Karin; Brinkmann, Martin; Müller, Frank

2015-03-01

Soft materials like liquids and polymers are part of everyday life, yet at school, this topic is rarely touched. Within the priority program SPP 1064 'Nano- and Microfluidics' of the German Science Foundation, we designed an outreach project that allows pupils (age 14 to 18) to perform hands-on experiments (www.labinabox.de). The experiments allow them e.g. to feel viscosity and viscoelasticity, experience surface tension or see structure formation. We call the modus operandi 'subjective experiments' to contrast them with the scientifically objective experiments, which pupils often describe as being boring. Over a dozen different experiments under the topic 'physics of fluids' are collected in a big box that travels to the school. Three other topics of boxes are available, 'physics of light, 'physics of liquid crystals', and 'physics of adhesion and friction'. Each experiment can be performed by 1-3 pupils within 10 - 20 min. That way, each scholar can perform 6 to 8 different small experiments within one topic. 'Subjective experiments' especially catch the attention of girls without disadvantaging boys. Both are fascinated by the hands-on physics experience and are therefore eager to perform also 'boring' objective experiments. Morover, before/after polls reveal that their interest in physics has greatly advanced. The project can easily be taken over and/or adapted to other topics in the natural sciences. Financial support of the German Science Foundation DFG is acknowledged.

The North Carolina A and T State University Student Space Shuttle Program

NASA Technical Reports Server (NTRS)

Hooker, F. D.; Ahrens, S. T.

1987-01-01

Inspired into being in 1979 by the late astronaut, Dr. Ronald McNair, the primary goal of this student centered program is to perform two experiments, Arthopod Development Study and Crystal Growth Study. Since 1979, 78 different students representing 12 majors have participated in every phase of development of the payload -- from coming up with the original ideas to final fabrication and testing. Students have also been involved in many extra activities such as presenting their results at annual meetings and hosting tours of our lab for local schools. The program has received extensive outside support in the form of funds, technical assistance and donated parts. The payload, made primarily out of aluminum, consists of a central column structure, a battery box, a crystal growth box, an arthropod development box, four control circuit boxes, and a thermograph box. The battery box contains 24, Eveready 6V, Alkaline batteries. The thermograph box contains 3 Ryan TempMentors. Fabrication of the payload is essentially complete and a complete testing program has been initiated.

Unloading Characteristics of Sand-drift in Wind-shallow Areas along Railway and the Effect of Sand Removal by Force of Wind

PubMed Central

Cheng, Jian-jun; Xin, Guo-Wei; Zhi, Ling-yan; Jiang, Fu-qiang

2017-01-01

Wind-shield walls decrease the velocity of wind-drift sand flow in transit. This results in sand accumulating in the wind-shadow zone of both windshield wall and track line, causing severe sand sediment hazard. This study reveals the characteristics of sand accumulation and the laws of wind-blown sand removal in the wind-shadow areas of three different types of windshield walls, utilizing three-dimensional numerical simulations and wind tunnel experiments and on-site sand sediment tests. The results revealed the formation of apparent vortex and acceleration zones on the leeward side of solid windshield walls. For uniform openings, the vortex area moved back and narrowed. When bottom-opening windshield walls were adopted, the track-supporting layer at the step became a conflux acceleration zone, forming a low velocity vortex zone near the track line. At high wind speeds, windshield walls with bottom-openings achieved improved sand dredging. Considering hydrodynamic mechanisms, the flow field structure on the leeward side of different types of windshield structures is a result of convergence and diffusion of fluids caused by an obstacle. This convergence and diffusion effect of air fluid is more apparent at high wind velocities, but not obvious at low wind velocities. PMID:28120915

Experimental investigation of cephapirin adsorption to quartz filter sands and dune sands

NASA Astrophysics Data System (ADS)

Peterson, Jonathan W.; O'Meara, Theresa A.; Seymour, Michael D.

2008-08-01

Batch experiments were performed to investigate cephapirin (a widely used veterinary antibiotic) adsorption on various size sands of low total organic carbon content (0.08-0.36 wt%). In the aqueous concentration range investigated (11-112 μmol/L cephapirin), adsorption to nearly pure quartz filter sands (0.50-3.35 mm diameter) is low. Isotherms are S-shaped and most display a region of minimum adsorption, where decreased adsorption occurs with increasing solution concentration, followed by increased adsorption at higher concentrations. Cephapirin adsorption to quartz-rich, feldspar-bearing dune sands (0.06-0.35 mm diameter), and the smallest quartz filter sand investigated (0.43-0.50 mm), can be described by linear sorption isotherms over the range of concentrations investigated. Distribution coefficients ( K d) range from 0.94 to 3.45 L/kg. No systematic relationship exists between grain size and amount of adsorption for any of the sands investigated. Cephapirin adsorption is positively correlated to the feldspar ratio (K-feldspar/(albite + Ca-plagioclase). Feldspar-ratio normalization of distribution coefficients was more effective than organic carbon normalization at reducing variability of K d values in the dune sands investigated.

Benthic photosynthesis and oxygen consumption in permeable carbonate sediments at Heron Island, Great Barrier Reef, Australia

NASA Astrophysics Data System (ADS)

Rasheed, Mohammed; Wild, Christian; Franke, Ulrich; Huettel, Markus

2004-01-01

In order to investigate benthic photosynthesis and oxygen demand in permeable carbonate sands and the impact of benthic boundary layer flow on sedimentary oxygen consumption, in situ and laboratory chamber experiments were carried out at Heron Island, Great Barrier Reef, Australia. Total photosynthesis, net primary production and respiration were estimated to be 162.9±43.4, 98.0±40.7, and 64.9±15.0 mmol C m -2 d -1, respectively. DIN and DIP fluxes for these sands reached 0.34 and 0.06 mmol m -2 d -1, respectively. Advective pore water exchange had a strong impact on oxygen consumption in the permeable sands. Consumption rates in the chamber with larger pressure gradient (20 rpm, 1.2 Pa between centre and rim) simulating a friction velocity of 0.6 cm s -1 were approximately two-fold higher than in the chambers with slow stirring (10 rpm, 0.2 Pa between centre and rim, friction velocity of 0.3 cm s -1). In the laboratory chamber experiments with stagnant water column, oxygen consumption was eight times lower than in the chamber with fast stirring. Laboratory chamber experiments with Br - tracer revealed solute exchange rates of 2.6, 2.2, 0.7 ml cm -2 d -1 at stirring rates of 20, 10, and 0 rpm, respectively. In a laboratory experiment investigating the effect of sediment permeability on oxygen and DIC fluxes, a three-fold higher permeability resulted in two- to three-fold higher oxygen consumption and DIC release rates. These experiments demonstrate the importance of boundary flow induced flushing of the upper layer of permeable carbonate sediment on oxygen uptake in the coral sands. The high filtration and oxidation rates in the sub-tropical permeable carbonate sediments and the subsequent release of nutrients and DIC reveal the importance of these sands for the recycling of matter in this oligotrophic environment.

Generation rate and particle size distribution of wood dust by handheld sanding operation.

PubMed

Ojima, Jun

2016-11-29

The International Agency for Research on Cancer (IARC) and Japan Society for Occupational Health (JSOH) classified wood dust as a human carcinogen. Former studies have suggested that sanding with a portable sander is one of the processes that are liable to cause highest exposure to wood dust. However, the wood dust by sanding operation has not been investigated sufficiently. In this study, the generation rate and the particle size distribution of the wood dust produced by handheld sanding operation were observed by laboratory experiments. Beech and cypress were taken as typical hard and soft wood specimen respectively, and sanded with a portable sander. Three grades of sand paper (coarse, medium, fine) were attached to the sander in turn to be tested. The quantity of the wood dust produced by the sander was measured by weighing the specimen before and after the sanding and then the generation rate of the dust was calculated. Soft wood generated more dust than hard wood due to the difference in abrasion durability. A coarse sand paper produced more dust than a fine sand paper. The particles of less than 1 μm diameter were scarcely observed in the wood dust. When the specimens were sanded with a fine sand paper, the mass median aerodynamic diameters of beech dust and cypress dust were 9.0 μm and 9.8 μm, respectively. Respirable wood dust is able to be controlled by general ventilation with more than 0.7-4.2 m 3 /min ventilation rate.

Implementing Adlerian Sand Tray Therapy with Adult Male Substance Abuse Offenders: A Phenomenological Inquiry

ERIC Educational Resources Information Center

Monakes, Sarah; Garza, Yvonne; Wiesner, Van, III; Watts, Richard E.

2011-01-01

The purpose of this phenomenological study was to understand the perceptions of adult male substance offenders who experienced sand tray therapy as an adjunct to their cognitive behavioral rehabilitative treatment. Results indicate a positive experience for participants. Implications for counselors are discussed. (Contains 1 table.)

Novel insights into freshwater hydrocarbon-rich sediments using metatranscriptomics: Opening the black box.

PubMed

Reid, Thomas; Chaganti, Subba Rao; Droppo, Ian G; Weisener, Christopher G

2018-06-01

Baseline biogeochemical surveys of natural environments is an often overlooked field of environmental studies. Too often research begins once contamination has occurred, with a knowledge gap as to how the affected area behaved prior to outside (often anthropogenic) influences. These baseline characterizations can provide insight into proposed bioremediation strategies crucial in cleaning up chemical spill sites or heavily mined regions. Hence, this study was conducted to survey the in-situ microbial activity within freshwater hydrocarbon-rich environments cutting through the McMurray formation - the geologic strata constituting the oil sands. We are the first to report in-situ functional variations among these freshwater microbial ecosystems using metatranscriptomics, providing insight into the in-situ gene expression within these naturally hydrocarbon-rich sites. Key genes involved in energy metabolism (nitrogen, sulfur and methane) and hydrocarbon degradation, including transcripts relating to the observed expression of methane oxidation are reported. This information provides better linkages between hydrocarbon impacted environments, closing knowledge gaps for optimizing not only oil sands mine reclamation but also enhancing microbial reclamation strategies in various freshwater environments. These finding can also be applied to existing contaminated environments, in need of efficient reclamation efforts. Copyright © 2018 Elsevier Ltd. All rights reserved.

Global sand trade is paving the way for a tragedy of the sand commons

NASA Astrophysics Data System (ADS)

Torres, A.; Brandt, J.; Lear, K.; Liu, J.

2016-12-01

In the first 40 years of the 21st century, planet Earth is highly likely to experience more urban land expansion than in all of history, an increase in transportation infrastructure by more than a third, and a great variety of land reclamation projects. While scientists are beginning to quantify the deep imprint of human infrastructure on biodiversity at large scales, its off-site impacts and linkages to sand mining and trade have been largely ignored. Sand is the most widely used building material in the world. With an ever-increasing demand for this resource, sand is being extracted at rates that far exceed its replenishment, and is becoming increasingly scarce. This has already led to conflicts around the world and will likely lead to a "tragedy of the sand commons" if sustainable sand mining and trade cannot be achieved. We investigate the environmental and socioeconomic interactions over large distances (telecouplings) of infrastructure development and sand mining and trade across diverse systems through transdisciplinary research and the recently proposed telecoupling framework. Our research is generating a thorough understanding of the telecouplings driven by an increasing demand for sand. In particular, we address three main research questions: 1) Where are the conflicts related to sand mining occurring?; 2) What are the major "sending" and "receiving" systems of sand?; and 3) What are the main components (e.g. causes, effects, agents, etc.) of telecoupled systems involving sand mining and trade? Our results highlight the role of global sand trade as a driver of environmental degradation that threatens the integrity of natural systems and their capacity to deliver key ecosystem services. In addition, infrastructure development and sand mining and trade have important implications for other sustainability challenges such as over-fishing and global warming. This knowledge will help to identify opportunities and tools to better promote a more sustainable use of sand, ultimately helping avoid a "tragedy of the sand commons".

Dredging and Sedimentation Control -- 1980, Proceedings of a Symposium Held in Alexandria, Virginia, 22-23 April 1980,

DTIC Science & Technology

1980-01-01

Island Naval Shipyard. Another two experiments involved by-passing sand around the inlet of Agua Hedionda 1-2 Lagoon, California, using fluidized trenches...closed duct configurations is discussed in Bailard and Inman (1975). The Agua Hedionda Lagoon selected for these experiments is located 30 miles...erations on a flooding tide direct the influx, depositing a sand bar. The latest of several system designs for Agua Hedionda Lagoon consisted of a l-4m deep

Payload bay atmospheric vent airflow testing at the Vibration and Acoustic Test Facility

NASA Technical Reports Server (NTRS)

Johnston, James D., Jr.

1988-01-01

Several concerns related to venting the Space Shuttle Orbiter payload bay during launch led to laboratory experiments with a flight-type vent box installed in the wall of a subsonic wind tunnel. This report describes the test setups and procedures used to acquire data for characterization of airflow through the vent box and acoustic tones radiated from the vent-box cavity. A flexible boundary-layer spoiler which reduced the vent-tone amplitude is described.

Properties of Fly Ash Blocks Made from Adobe Mould

NASA Astrophysics Data System (ADS)

Chokhani, Alankrit; Divakar, B. S.; Jawalgi, Archana S.; Renukadevi, M. V.; Jagadish, K. S.

2018-02-01

Fly ash being one of the industrial waste products poses a serious disposal problem. This paper presents an experimental study of utilization of fly ash to produce blocks with varying proportions and mix combinations. Composition of fly ash blocks mainly consist of fly ash and sand, with cementitious product as either cement, lime or both, such as fly ash-sand-cement, fly ash-sand-lime and fly ash-sand-cement-lime are used. Four different proportions for each of the mix combinations are experimented. Compressive strength, water absorption, Initial rate of absorption, and dry density of fly ash blocks are studied. The influence of partial and complete replacement of cement by lime is examined.

Properties of Fly Ash Blocks Made from Adobe Mould

NASA Astrophysics Data System (ADS)

Chokhani, Alankrit; Divakar, B. S.; Jawalgi, Archana S.; Renukadevi, M. V.; Jagadish, K. S.

2018-06-01

Fly ash being one of the industrial waste products poses a serious disposal problem. This paper presents an experimental study of utilization of fly ash to produce blocks with varying proportions and mix combinations. Composition of fly ash blocks mainly consist of fly ash and sand, with cementitious product as either cement, lime or both, such as fly ash-sand-cement, fly ash-sand-lime and fly ash-sand-cement-lime are used. Four different proportions for each of the mix combinations are experimented. Compressive strength, water absorption, Initial rate of absorption, and dry density of fly ash blocks are studied. The influence of partial and complete replacement of cement by lime is examined.

When Field Experiments Yield Unexpected Results: Lessons Learned from Measuring Selection in White Sands Lizards

PubMed Central

Hardwick, Kayla M.; Harmon, Luke J.; Hardwick, Scott D.; Rosenblum, Erica Bree

2015-01-01

Determining the adaptive significance of phenotypic traits is key for understanding evolution and diversification in natural populations. However, evolutionary biologists have an incomplete understanding of how specific traits affect fitness in most populations. The White Sands system provides an opportunity to study the adaptive significance of traits in an experimental context. Blanched color evolved recently in three species of lizards inhabiting the gypsum dunes of White Sands and is likely an adaptation to avoid predation. To determine whether there is a relationship between color and susceptibility to predation in White Sands lizards, we conducted enclosure experiments, quantifying survivorship of Holbrookia maculate exhibiting substrate-matched and substrate-mismatched phenotypes. Lizards in our study experienced strong predation. Color did not have a significant effect on survival, but we found several unexpected relationships including variation in predation over small spatial and temporal scales. In addition, we detected a marginally significant interaction between sex and color, suggesting selection for substrate matching may be stronger for males than females. We use our results as a case study to examine six major challenges frequently encountered in field-based studies of natural selection, and suggest that insight into the complexities of selection often results when experiments turn out differently than expected. PMID:25714838

Fluensulfone sorption and mobility as affected by soil type.

PubMed

Morris, Kelly A; Li, Xiao; Langston, David B; Davis, Richard F; Timper, Patricia; Grey, Timothy L

2018-02-01

Fluensulfone is a fluoroalkenyl chemical with activity against multiple genera of plant-parasitic nematodes. The adsorption, desorption, and mobility of fluensulfone were evaluated on multiple soils from the USA in laboratory and column experiments. Adsorption data regressed to the logarithmic Freundlich equation resulted in isotherm values of 1.24 to 3.28. Soil adsorption of fluensulfone correlated positively with organic matter (0.67) and clay (0.34), but negatively with sand (-0.54). Fluensulfone soil desorption correlated to pH (0.38) and cation exchange capacity (0.44). Fluensulfone desorption from Arredondo sand soil was 26%, and from other soils ranged from 43 to 70%. In mobility experiments, fluensulfone in the leachate peaked at 3 h, gradually declining and becoming undetectable after 9 h. Recovery from leachate was 45% of the initial fluensulfone applied to the soil surface. In separate experiments, 30-cm-long soil columns were saturated with 1 L of water, and then segregated into three 10-cm sections. Fluensulfone recovery was 41, 34, 29, and 13% in Chualar sandy loam, Arredondo sand, Greenville sandy clay loam, and Tifton loamy sand, respectively, in the top 10-cm section. Data indicated that soil organic matter and clay contents will affect sorption, mobility, and dissipation of fluensulfone. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Numerical simulation of mud erosion rate in sand-mud alternate layer and comparison with experiment

NASA Astrophysics Data System (ADS)

Yoshida, T.; Yamaguchi, T.; Oyama, H.; Sato, T.

2015-12-01

For gas production from methane hydrates in sand-mud alternate layers, depressurization method is expected as feasible. After methane hydrate is dissociated, gas and water flow in pore space. There is a concern about the erosion of mud surface and it may result in flow blockage that disturbs the gas production. As a part of a Japanese National hydrate research program (MH21, funded by METI), we developed a numerical simulation of water-induced mud erosion in pore-scale sand-mud domains to model such mud erosion. The size of which is of the order of 100 micro meter. Water flow is simulated using a lattice Boltzmann method (LBM) and mud surface is treated as solid boundary with arbitrary shape, which changes with time. Periodic boundary condition is adopted at the domain boundaries, except for the surface of mud layers and the upper side. Shear stress acting on the mud surface is calculated using a momentum-exchange method. Mud layer is eroded when the shear stress exceeds a threshold coined a critical shear stress. In this study, we compared the simulated mud erosion rate with experimental data acquired from an experiment using artificial sand-mud core. As a result, the simulated erosion rate agrees well with that of the experiment.

Evaluation of Pre-marketing Factors to Predict Post-marketing Boxed Warnings and Safety Withdrawals.

PubMed

Schick, Andreas; Miller, Kathleen L; Lanthier, Michael; Dal Pan, Gerald; Nardinelli, Clark

2017-06-01

An important goal in drug regulation is understanding serious safety issues with new drugs as soon as possible. Achieving this goal requires us to understand whether information provided during the Food and Drug Administration (FDA) drug review can predict serious safety issues that are usually identified after the product is approved. However, research on this topic remains understudied. In this paper, we examine whether any pre-marketing drug characteristics are associated with serious post-marketing safety actions. We study this question using an internal FDA database containing every new small molecule drug submitted to the FDA's Center for Drug Evaluation and Research (CDER) on or after November 21, 1997, and approved and commercially launched before December 31, 2009. Serious post-marketing safety actions include whether these drugs ever experienced either a post-marketing boxed warning or a withdrawal from the market due to safety concerns. A random effects logistic regression model was used to test whether any pre-marketing characteristics were associated with either post-marketing safety action. A total of 219 new molecular entities were analyzed. Among these drugs, 11 experienced a safety withdrawal and 30 received boxed warnings by July 31, 2016. Contrary to prevailing hypotheses, we find that neither clinical trial sample sizes nor review time windows are associated with the addition of a post-marketing boxed warning or safety withdrawal. However, we do find that new drugs approved with either a boxed warning or priority review are more likely to experience post-marketing boxed warnings. Furthermore, drugs approved with boxed warnings tend to receive post-marketing boxed warnings resulting from new safety information that are unrelated to the original warning. Drugs approved with a boxed warning are 3.88 times more likely to receive a post-marketing boxed warning, while drugs approved with a priority review are 3.51 times more likely to receive a post-marketing boxed warning. Although drugs approved with a boxed warning or priority review are more likely to experience serious post-marketing safety events, other information provided during the FDA drug review that is easy to quantify is generally not associated with post-marketing safety events. It appears that these post-marketing events are not discernible during a pre-marketing review and therefore might not be avoidable using current review data.

Studies on uptake of trivalent and hexavalent chromium by maize (Zea mays).

PubMed

Mishra, S; Singh, V; Srivastava, S; Srivastava, R; Srivastava, M M; Dass, S; Satsangi, G P; Prakash, S

1995-05-01

Pot culture experiments were carried out to study the uptake and translocation of chromium from irrigation water when supplied in its trivalent and hexavalent states to maize plants grown in soil and sand culture. The uptake of chromium was observed to increase with increase in the concentration for both oxidation states of chromium. For the root, the observed order of uptake was CrIII sand > CrVI sand > CrIII soil > CrVI soil, whereas in the lower shoot, upper shoot and fruit the order was CrVI sand > CrVI soil > CrIII sand > CrIII soil. Significantly high uptake of chromium by roots in the sand culture (CrIII treatment) is attributed to the effect of root exudates and degradation products on the mobilization of CrIII. In aerial parts of the plants a higher uptake was observed when the initial supply was CrVI. The trends observed are explained on the basis of the redox behaviour of chromium.

Contaminant removal and hydraulic conductivity of laboratory rain garden systems for stormwater treatment.

PubMed

Good, J F; O'Sullivan, A D; Wicke, D; Cochrane, T A

2012-01-01

In order to evaluate the influence of substrate composition on stormwater treatment and hydraulic effectiveness, mesocosm-scale (180 L, 0.17 m(2)) laboratory rain gardens were established. Saturated (constant head) hydraulic conductivity was determined before and after contaminant (Cu, Zn, Pb and nutrients) removal experiments on three rain garden systems with various proportions of organic topsoil. The system with only topsoil had the lowest saturated hydraulic conductivity (160-164 mm/h) and poorest metal removal efficiency (Cu ≤ 69.0% and Zn ≤ 71.4%). Systems with sand and a sand-topsoil mix demonstrated good metal removal (Cu up to 83.3%, Zn up to 94.5%, Pb up to 97.3%) with adequate hydraulic conductivity (sand: 800-805 mm/h, sand-topsoil: 290-302 mm/h). Total metal amounts in the effluent were <50% of influent amounts for all experiments, with the exception of Cu removal in the topsoil-only system, which was negligible due to high dissolved fraction. Metal removal was greater when effluent pH was elevated (up to 7.38) provided by the calcareous sand in two of the systems, whereas the topsoil-only system lacked an alkaline source. Organic topsoil, a typical component in rain garden systems, influenced pH, resulting in poorer treatment due to higher dissolved metal fractions.

Experimental Study of Sand Production and Mud Erosion Phenomena for Sand Mud Alternate Layer

NASA Astrophysics Data System (ADS)

Oyama, H.; Sato, T.

2014-12-01

Methane hydrates are crystalline, ice-like compounds under specific thermodynamic conditions. The existence of methane hydrates is confirmed in the Nankai Trough, an offshore area of Japan. Japan's Methane Hydrate Research and Development Program (MH21) has been under way at this area. In the early 2013, the world's first intentional gas production attempt from marine gas hydrate deposits was tried and accomplished in the Daini Atumi Knoll area of the Eastern Nankai Trough. For gas production, depressurization method has been considered as a promising gas production technique from methane hydrate reservoirs. However, considering of continuous gas production over a long period, there is still something to clarify. The methane hydrate crystals are very small and existed in the intergranular pores of sandy layer of turbidite sediments. When the intergranular methane hydrates will be dissociated, it is considered that dissociated gas and water flow will cause sand production and mud erosion phenomena of turbidite sediments. The production of framework sands into a well is one of the problems plaguing the gas because of its adverse effects on well productivity and equipment. If the eroded mud is accumulated in the pore space of sand, skin is generated and permeability becomes lower. In addition, mud erosion has a negative effect for the well stability. This research presents an experimental study to understand sand production and mud erosion phenomena for sand mud alternate layer. The aims of this study are to understand these phenomena and clarify driving forces. In our experiments, we used an artificial sedimentary core and performed experiments under various conditions. As the results, the driving forces of these phenomena are not dissociation gas flow but water flow through pore.

Shear dilatancy and acoustic emission in dry and saturated granular materials

NASA Astrophysics Data System (ADS)

Brodsky, E. E.; Siman-Tov, S.

2017-12-01

Shearing of granular materials plays a strong role in naturally sheared systems as landslides and faults. Many works on granular flows have concentrated on dry materials, but relatively little work has been done on water saturated sands. Here we experimentally investigate dry versus saturated quartz-rich sand to understand the effect of the fluid medium on the rheology and acoustic waves emission of the sheared sand. The sand was sheared in a rotary shear rheometer under applied constant normal stress boundary at low (100 µm/s) to high (1 m/s) velocities. Mechanical, acoustic data and deformation were continuously recorded and imaged. For dry and water saturated experiments the granular volume remains constant for low shear velocities ( 10-3 m/s) and increases during shearing at higher velocities ( 1 m/s). Continuous imaging of the sheared sand show that the steady state shear band thickness is thicker during the high velocity steps. No significant change observed in the shear band thickness between dry and water saturated experiments. In contrast, the amount of dilation during water saturated experiments is about half the value measured for dry material. The measured decrease cannot be explained by shear band thickness change as such is not exist. However, the reduced dilation is supported by our acoustic measurements. In general, the event rate and acoustic event amplitudes increase with shear velocity. While isolated events are clearly detected during low velocities at higher the events overlap, resulting in a noisy signal. Although detection is better for saturated experiments, during the high velocity steps the acoustic energy measured from the signal is lower compared to that recorded for dry experiments. We suggest that the presence of fluid suppresses grain motion and particles impacts leading to mild increase in the internal pressure and therefore for the reduced dilation. In addition, the viscosity of fluids may influence the internal pressure via hydrodynamic lubrication which increases the fluid pressure and therefore increases the dilation compared to dry material. The effect is particularly strong for high viscosity fluids, as observed in the silicon oil experiment. Therefore, fluid viscosity can play a crucial role in determining the physics that controls the rheology of the sheared material.

Bedform development in mixed sand-mud: The contrasting role of cohesive forces in flow and bed

NASA Astrophysics Data System (ADS)

Baas, Jaco H.; Davies, Alan G.; Malarkey, Jonathan

2013-01-01

The majority of subaqueous sediment on Earth consists of mixtures of cohesive clay and cohesionless sand and silt, but the role of cohesion on the development and stability of sedimentary bedforms is poorly understood. The results of new laboratory flume experiments on bedform development in cohesive, mixed sand-mud beds are compared with the results of previous experiments in which cohesive forces in high concentration clay flows dominated bedform development. Even though both series of mixed sand-mud experiments were conducted at similar flow velocities, the textural and structural properties of the bedforms were sufficiently different to permit the designation of key criteria for identifying bedform generation under cohesive flows against bedform generation on cohesive substrates. These criteria are essential for improving bedform size predictions in sediment transport modelling in modern sedimentary environments and for the reconstruction of depositional processes in the geological record. The current ripples developing on the cohesive, mixed sand-mud beds, with bed mud fractions of up to 18%, were significantly smaller than equivalent bedforms in noncohesive sand. Moreover, the bedform height showed a stronger inversely proportional relationship with initial bed mud fraction than the bedform wavelength. This is in contrast with the bedforms developing under the cohesive clay flows, which tend to increase in size with increasing suspended clay concentration until the flow turbulence is fully suppressed. Selective removal of clay from the mixed beds, i.e., clay winnowing, was found to be an important process, with 82-100% clay entrained into suspension after 2 h of bedform development. This winnowing process led to the development of a sand-rich armouring layer. This armouring layer is inferred to have protected the underlying mixed sand-mud from prolonged erosion, and in conjunction with strong cohesive forces in the bed may have caused the smaller size of the bedforms. Winnowing was less efficient for the bedforms developing under the cohesive clay flows, where bedforms consisting of muddy sand were more characteristic. The winnowed sand was also found to heal irregularly scoured topography, thus reestablishing classic quasitriangular bedform shapes. In cohesive flows, the bedforms had more variable shapes, and the healing process was confined to lower transitional plug flows in which strong turbulence is only present close to the sediment bed. Furthermore, the bedforms on the cohesive beds tended to form angle-of-repose cross lamination, whereas low angle cross lamination was more common in bedforms under cohesive flows. In general terms, erosional bedforms prevail when cohesive forces in the bed dominate bedform dynamics, whereas depositional bedforms prevail when cohesive forces in the flow dominate bedform dynamics. Empirical relationships between the proportion of cohesive mud in the mixed sand-mud bed and the development rate and size of the bedforms are defined for future use in field and laboratory studies.

Salinization owing to evaporation from bare-soil surfaces and its influences on the evaporation

NASA Astrophysics Data System (ADS)

Shimojimaa, Eiichi; Yoshioka, Ryuma; Tamagawa, Ichiro

1996-04-01

To investigate the relationship between evaporation and salinization, the surfaces of three columns of uniform porous materials, desert dune sand, silica sand and glass beads, respectively, were exposed to a temperature-, humidity- and/or wind-speed-controlled ambient atmosphere. For the dune sand, chemicals such as Na +, Ca 2+, Cl - and SO 42-, dissolved mainly from CaSO 4, Na 2SO 4, CaCO 3 and NaC1 in the sand particles, caused marked salinization near the top surface. Slow dissolution of Na 2SO 4 and CaSO 4 influenced the development of concentration profiles for SO 42- and Na + markedly for months after the beginning of the experiment, while the profile of Cl - was not affected directly, because dissolution of NaCl was rapid. Concentration profiles of Cl - for the glass beads and for the silica sand columns filled with a high concentration of NaCI solution of (10 4 mg1 -1 for Cl -), were analysed similarly. Experimental results suggested that the vapour flux in a dry soil became larger because of the increase in the gradient of the vapour density caused by greater chemical enrichment near the top surface compared with that at the evaporation surface. The vapour flux also became smaller as the gradient of the vapour density decreased, owing to the markedly enriched evaporation surface. In the experiment with glass beads, filled with the NaCl solution, solute crystallization (4-10 mm thick) was observed. For the dune sand, only when a turbulent airflow was applied did a crust (a few millimetres in thickness) form entirely on the top surface. Such deposition led to a reduction in the flux of water vapour as the permeable cross-sectional area decreased. The resistance to transfer increased three to ten times for the glass beads but only by 30% for the dune sand. The lower increase for the dune sand may be due to penetration of the applied airflow into cracks in the crust.

Biochar-Induced Changes in Soil Hydraulic Conductivity and Dissolved Nutrient Fluxes Constrained by Laboratory Experiments

PubMed Central

Barnes, Rebecca T.; Gallagher, Morgan E.; Masiello, Caroline A.; Liu, Zuolin; Dugan, Brandon

2014-01-01

The addition of charcoal (or biochar) to soil has significant carbon sequestration and agronomic potential, making it important to determine how this potentially large anthropogenic carbon influx will alter ecosystem functions. We used column experiments to quantify how hydrologic and nutrient-retention characteristics of three soil materials differed with biochar amendment. We compared three homogeneous soil materials (sand, organic-rich topsoil, and clay-rich Hapludert) to provide a basic understanding of biochar-soil-water interactions. On average, biochar amendment decreased saturated hydraulic conductivity (K) by 92% in sand and 67% in organic soil, but increased K by 328% in clay-rich soil. The change in K for sand was not predicted by the accompanying physical changes to the soil mixture; the sand-biochar mixture was less dense and more porous than sand without biochar. We propose two hydrologic pathways that are potential drivers for this behavior: one through the interstitial biochar-sand space and a second through pores within the biochar grains themselves. This second pathway adds to the porosity of the soil mixture; however, it likely does not add to the effective soil K due to its tortuosity and smaller pore size. Therefore, the addition of biochar can increase or decrease soil drainage, and suggests that any potential improvement of water delivery to plants is dependent on soil type, biochar amendment rate, and biochar properties. Changes in dissolved carbon (C) and nitrogen (N) fluxes also differed; with biochar increasing the C flux from organic-poor sand, decreasing it from organic-rich soils, and retaining small amounts of soil-derived N. The aromaticity of C lost from sand and clay increased, suggesting lost C was biochar-derived; though the loss accounts for only 0.05% of added biochar-C. Thus, the direction and magnitude of hydraulic, C, and N changes associated with biochar amendments are soil type (composition and particle size) dependent. PMID:25251677

Evaluating Rotavirus and Norovirus transport processes in standardised and natural soil-water columns experiments

NASA Astrophysics Data System (ADS)

Gamazo, Pablo; Schijven, Jack; Victoria, Matias; Alvareda, Elena; López Tort, Fernando; Ramos, Julián; Lizasoain, Andrés; Sapriza, Gonzalo; Castells, Matias; Colina, Rodney

2017-04-01

In Uruguay, as in many developed and developing countries, rotavirus and norovirus are major causes of diarrhea and others symptoms of acute gastroenteritis. In some areas of Uruguay, groundwater is the only source of water for human consumption. In the rural area of the Salto district, virus contamination has been detected in several groundwater wells. Because sewer coverage is low, the most probable sources of contamination are nearby septic systems. This work aims to evaluate the transport of rotavirus and norovirus from clinic samples in two sets of column experiments under saturated conditions: 6.7-cm columns with quartz sand (ionic strength 1mM, pH 7.0) and with sand from the Salto aquifer (Uruguay) (9,2% coarse sand, 47,8% medium sand, 40,5% fine sand, magnesium/calcium bicarbonate water, Ionic strength 15.1 mM, pH 7.2). Both viruses were seeded for 2 pore volumes onto the columns. Samples were collected at the column outlet and viruses were enumerated by Q-PRCR. Breakthrough curves were constructed and fitted to a two-site kinetic attachment/detachment model, including blocking using Hydrus-1D. In the quartz sand column, both rotavirus and norovirus were removed two orders in magnitude. In the Salto sand column, rotavirus was removed 2 log10 as well, but norovirus was removed 4 log10. The fitting of the breakthrough curves indicated that blocking played a role for rotavirus in the Salto sand column. These results are consistent with the field observation where only rotavirus was detected in the Salto aquifer, while similar concentrations in Salto sewer effluent were measured for both viruses. This work, besides reporting actual parameters values for human virus transport modelling, shows the significant differences in transport that human viruses can have in standardised and natural soil-water systems.

Measuring and Modeling the Effect of Surface Moisture on the Spectral Reflectance of Coastal Beach Sand

PubMed Central

Nolet, Corjan; Poortinga, Ate; Roosjen, Peter; Bartholomeus, Harm; Ruessink, Gerben

2014-01-01

Surface moisture is an important supply limiting factor for aeolian sand transport, which is the primary driver of coastal dune development. As such, it is critical to account for the control of surface moisture on available sand for dune building. Optical remote sensing has the potential to measure surface moisture at a high spatio-temporal resolution. It is based on the principle that wet sand appears darker than dry sand: it is less reflective. The goals of this study are (1) to measure and model reflectance under controlled laboratory conditions as function of wavelength () and surface moisture () over the optical domain of 350–2500 nm, and (2) to explore the implications of our laboratory findings for accurately mapping the distribution of surface moisture under natural conditions. A laboratory spectroscopy experiment was conducted to measure spectral reflectance (1 nm interval) under different surface moisture conditions using beach sand. A non-linear increase of reflectance upon drying was observed over the full range of wavelengths. Two models were developed and tested. The first model is grounded in optics and describes the proportional contribution of scattering and absorption of light by pore water in an unsaturated sand matrix. The second model is grounded in soil physics and links the hydraulic behaviour of pore water in an unsaturated sand matrix to its optical properties. The optical model performed well for volumetric moisture content 24% ( 0.97), but underestimated reflectance for between 24–30% ( 0.92), most notable around the 1940 nm water absorption peak. The soil-physical model performed very well ( 0.99) but is limited to 4% 24%. Results from a field experiment show that a short-wave infrared terrestrial laser scanner ( = 1550 nm) can accurately relate surface moisture to reflectance (standard error 2.6%), demonstrating its potential to derive spatially extensive surface moisture maps of a natural coastal beach. PMID:25383709

The AR Sandbox: Augmented Reality in Geoscience Education

NASA Astrophysics Data System (ADS)

Kreylos, O.; Kellogg, L. H.; Reed, S.; Hsi, S.; Yikilmaz, M. B.; Schladow, G.; Segale, H.; Chan, L.

2016-12-01

The AR Sandbox is a combination of a physical box full of sand, a 3D (depth) camera such as a Microsoft Kinect, a data projector, and a computer running open-source software, creating a responsive and interactive system to teach geoscience concepts in formal or informal contexts. As one or more users shape the sand surface to create planes, hills, or valleys, the 3D camera scans the surface in real-time, the software creates a dynamic topographic map including elevation color maps and contour lines, and the projector projects that map back onto the sand surface such that real and projected features match exactly. In addition, users can add virtual water to the sandbox, which realistically flows over the real surface driven by a real-time fluid flow simulation. The AR Sandbox can teach basic geographic and hydrologic skills and concepts such as reading topographic maps, interpreting contour lines, formation of watersheds, flooding, or surface wave propagation in a hands-on and explorative manner. AR Sandbox installations in more than 150 institutions have shown high audience engagement and long dwell times of often 20 minutes and more. In a more formal context, the AR Sandbox can be used in field trip preparation, and can teach advanced geoscience skills such as extrapolating 3D sub-surface shapes from surface expression, via advanced software features such as the ability to load digital models of real landscapes and guiding users towards recreating them in the sandbox. Blueprints, installation instructions, and the open-source AR Sandbox software package are available at http://arsandbox.org .

TRANSPORT OF CHROMIUM AND SELENIUM IN A PRISTINE SAND AND GRAVEL AQUIFER: ROLE OF ADSORPTION PROCESSES

EPA Science Inventory

Field transport experiments were conducted in an oxic sand and gravel aquifer using Br (bromide ion), Cr (chromium, injected as Cr(VI)), Se (selenium, injected as Se(VI)), and other tracers. The aquifer has mildly acidic pH values and low concentrations of dissolved salts. Within...

Infants Make Quantity Discriminations for Substances

ERIC Educational Resources Information Center

Hespos, Susan J.; Dora, Begum; Rips, Lance J.; Christie, Stella

2012-01-01

Infants can track small groups of solid objects, and infants can respond when these quantities change. But earlier work is equivocal about whether infants can track continuous substances, such as piles of sand. Experiment 1 ("N" = 88) used a habituation paradigm to show infants can register changes in the size of piles of sand that they…

"Drawing in the Sand" as a Tool for Teaching Coastal Geography

ERIC Educational Resources Information Center

Fagan, Joseph B.; Sturm, Sean

2015-01-01

Field trips are recognized as an essential component of the study of geography. They are popular with learners and teachers, but their value as learning experiences is largely assumed. What is needed are interactive and relevant learning activities like "drawing in the sand," a participatory learning activity that has been introduced…

Investigation of Dynamic Properties of Water-Saturated Sand by the Results of the Inverse Experiment Technique

NASA Astrophysics Data System (ADS)

Bragov, A. M.; Balandin, Vl. V.; Kotov, V. L.; Balandin, Vl. Vl.

2018-04-01

We present new experimental results on the investigation of the dynamic properties of sand soil on the basis of the inverse experiment technique using a measuring rod with a flat front-end face. A limited applicability has been shown of the method using the procedure for correcting the shape of the deformation pulse due to dispersion during its propagation in the measuring rod. Estimates of the pulse maximum have been obtained and the results of comparison of numerical calculations with experimental data are given. The sufficient accuracy in determining the drag force during the quasi-stationary stage of penetration has been established. The parameters of dynamic compressibility and resistance to shear of water-saturated sand have been determined in the course of the experimental-theoretical analysis of the maximum values of the drag force and its values at the quasi-stationary stage of penetration. It has been shown that with almost complete water saturation of sand its shear properties are reduced but remain significant in the practically important range of penetration rates.

Generation rate and particle size distribution of wood dust by handheld sanding operation

PubMed Central

Ojima, Jun

2016-01-01

Objectives: The International Agency for Research on Cancer (IARC) and Japan Society for Occupational Health (JSOH) classified wood dust as a human carcinogen. Former studies have suggested that sanding with a portable sander is one of the processes that are liable to cause highest exposure to wood dust. However, the wood dust by sanding operation has not been investigated sufficiently. In this study, the generation rate and the particle size distribution of the wood dust produced by handheld sanding operation were observed by laboratory experiments. Methods: Beech and cypress were taken as typical hard and soft wood specimen respectively, and sanded with a portable sander. Three grades of sand paper (coarse, medium, fine) were attached to the sander in turn to be tested. The quantity of the wood dust produced by the sander was measured by weighing the specimen before and after the sanding and then the generation rate of the dust was calculated. Results: Soft wood generated more dust than hard wood due to the difference in abrasion durability. A coarse sand paper produced more dust than a fine sand paper. The particles of less than 1 μm diameter were scarcely observed in the wood dust. When the specimens were sanded with a fine sand paper, the mass median aerodynamic diameters of beech dust and cypress dust were 9.0 μm and 9.8 μm, respectively. Conclusions: Respirable wood dust is able to be controlled by general ventilation with more than 0.7-4.2 m3/min ventilation rate. PMID:27725491

The plant G box promoter sequence activates transcription in Saccharomyces cerevisiae and is bound in vitro by a yeast activity similar to GBF, the plant G box binding factor.

PubMed Central

Donald, R G; Schindler, U; Batschauer, A; Cashmore, A R

1990-01-01

G box and I box sequences of the Arabidopsis thaliana ribulose-bisphosphate-1,5-carboxylase small subunit (RBCS) promoter are required for expression mediated by the Arabidopsis rbcS-1A promoter in transgenic tobacco plants and are bound in vitro by factors from plant nuclear extracts termed GBF and GA-1, respectively. We show here that a -390 to -60 rbcS-1A promoter fragment containing the G box and two I boxes activates transcription from a truncated iso-1-cytochrome c (CYC1) gene promoter in Saccharomyces cerevisiae. Mutagenesis of either the rbcS-1A G box or both I box sequences eliminated the expression mediated by this fragment. When polymerized, I box oligonucleotides were also capable of enhancing expression from the truncated CYC1 promoter. Single-copy G box sequences from the Arabidopsis rbcS-1A, Arabidopsis Adh and tomato rbcS-3A promoters were more potent activators and were used in mobility shift assays to identify a DNA binding activity in yeast functionally similar to GBF. In methylation interference experiments, the binding specificity of the yeast protein was indistinguishable from that obtained with plant nuclear extracts. Images Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:2161333

Application of Magnetic and Geotechnical Methods for Archaeological Site Investigations

DTIC Science & Technology

2011-07-01

national historic preservation act NRM natural remnant magnetism NS north-south nT nano Tesla ID inside diameter OSB oriented strand board psi...3.4 Soil Box Experiments Compaction tests were conducted by loading soil into a wooden box (1 m3) constructed of oriented strand board ( OSB ) and

Synthesis of Bis(1,2-Dimethylimidazole)Copper(I)Hexafluorophosphate: An Experiment Using a Glove Box

ERIC Educational Resources Information Center

Niewahner, J. H.; Walters, Keith A.

2007-01-01

A detailed description of the synthesis of bis(1,2-dimethylimidazole)copper(I) hexafluorophosphate by using techniques in a glove box is presented. The results shows that the synthesis of the copper complex has a distinct color change indicating by-product oxidation by oxygen.

Barriers on the brink? The complex intertwined roles of geologic framework, sediment availability and sea-level rise in island evolution

USGS Publications Warehouse

Moore, Laura; List, Jeffrey H.; Williams, S. Jeffress; Patsch, Kiki; Rosati, Julie D.; Wang, Ping; Roberts, Tiffany M.

2011-01-01

Sensitivity experiments in the North Carolina Outer Banks (OBX) have previously revealed that substrate sand proportion, followed by substrate slope, sea-level rise rate and sediment-loss rate are the most important factors in determining how barrier islands respond to sea-level rise. High sediment-loss rates and low substrate sand proportions cause barriers to be smaller and more deeply incised. Thus, as sea level rise rates increase, more deeply incised barriers do not need to migrate as far landward as larger, less-incised barriers to liberate sand from the shoreface. However, if the combination of sand losses and substrate sand proportions requires a barrier to migrate landward faster than the shoreface can erode to replenish losses, a barrier will change state and begin to disintegrate. Because the substrate of the OBXis sand-rich, these barriers are likely to persist in the near-term. In contrast, model simulations for the Chandeleur Islands, Louisiana suggest sediment loss rates are too high and/or substrate sand proportions are too low to be matched by liberation of shoreface sand. These simulations further suggest that a state change, from a landward-migrating barrier system to a subaqueous shoal complex, is either already underway or imminent.

Electromagnetic Pulse (EMP) from the Magnetic Bubble Source as a Discriminator of Underground Nuclear Explosions, Including Cavity Decoupling

DTIC Science & Technology

2011-02-01

planned shock physics experiments (SPE) 4. Design/develop a very low frequency (VLF)/ELF pulsar to serve as an underground calibration source 5...Carry out underground (in tunnels, etc.) pulsar calibration experiments  A-1 APPENDIX A. ABBREVIATIONS AND ACRONYMS CORRTEX Continuous Reflectometry...Site Office P.O. Box 98521 M/S NLV 101 Las Vegas, NV 89193-8521 ATTN: Ping Lee 1 Los Alamos National Laboratory PO Box 1663 Los Alamos, NM 87545

Stress and temperature distributions of individual particles in a shock wave propagating through dry and wet sand mixtures

NASA Astrophysics Data System (ADS)

Schumaker, Merit G.; Kennedy, Gregory; Thadhani, Naresh; Hankin, Markos; Stewart, Sarah T.; Borg, John P.

2017-01-01

Determining stress and temperature distributions of dynamically compacted particles is of interest to the geophysical and astrological research communities. However, the researcher cannot easily observe particle interactions during a planar shock experiment. By using mesoscale simulations, we can unravel granular particle interactions. Unlike homogenous materials, the averaged Hugoniot state for heterogeneous granular materials differs from the individual stress and temperature states of particles during a shock event. From planar shock experiments for dry and water-saturated Oklahoma sand, we constructed simulations using Sandia National Laboratory code known as CTH and then compared these simulated results to the experimental results. This document compares and presents stress and temperature distributions from simulations, with a discussion on the difference between Hugoniot measurements and distribution peaks for dry and water-saturated sand.

BEATBOX v1.0: Background Error Analysis Testbed with Box Models

NASA Astrophysics Data System (ADS)

Knote, Christoph; Barré, Jérôme; Eckl, Max

2018-02-01

The Background Error Analysis Testbed (BEATBOX) is a new data assimilation framework for box models. Based on the BOX Model eXtension (BOXMOX) to the Kinetic Pre-Processor (KPP), this framework allows users to conduct performance evaluations of data assimilation experiments, sensitivity analyses, and detailed chemical scheme diagnostics from an observation simulation system experiment (OSSE) point of view. The BEATBOX framework incorporates an observation simulator and a data assimilation system with the possibility of choosing ensemble, adjoint, or combined sensitivities. A user-friendly, Python-based interface allows for the tuning of many parameters for atmospheric chemistry and data assimilation research as well as for educational purposes, for example observation error, model covariances, ensemble size, perturbation distribution in the initial conditions, and so on. In this work, the testbed is described and two case studies are presented to illustrate the design of a typical OSSE experiment, data assimilation experiments, a sensitivity analysis, and a method for diagnosing model errors. BEATBOX is released as an open source tool for the atmospheric chemistry and data assimilation communities.

Laboratory Experiments of Sand Ripples with Bimodal Size Distributions Under Asymmetric Oscillatory Flows

NASA Astrophysics Data System (ADS)

Calantoni, J.; Landry, B. J.

2010-12-01

The dynamics of sand ripples are vital to understanding numerous coastal processes such as sediment transport, wave attenuation, boundary layer development, and seafloor acoustic properties. Though significant laboratory research has been conducted to elucidate oscillatory flow morphodynamics under various constant and transient forcing conditions, the majority of the previous experiments were conducted only for beds with unimodal size distributions of sediment. Recent oscillatory flow experiments as well as past laboratory observations in uniform flows suggest that the presence of heterogeneous size sand compositions may significantly impact ripple morphology, resulting in a variety of observable effects (e.g., sediment sorting, bed armoring, and altered transport rates). Experimental work was conducted in a small oscillatory flow tunnel at the Sediment Dynamics Laboratory at the Naval Research Laboratory, Stennis Space Center. Three different monochromatic oscillatory forcings having velocity asymmetry were used to study sand ripple dynamics over five bimodal and two unimodal sediment beds. The seven different mixtures were composed using two unimodal sands of different colors (blue/white) and median grain diameters (d=0.31 mm / d=0.65 mm) combined into various mixtures by mass (i.e., 0/100; 10/90; 25/75; 50/50; 75/25; 90/10; and 100/0 which denotes mass percentage of blue/white sand, respectively, within each mixture). High-definition video of the sediment bed profile was acquired in conjunction with sediment trap measurements to resolve differences in ripple geometries, migration and evolution rates due to the different sediment mixtures and flow conditions. Observational findings clearly illustrate sediment stratification within ripple crests and the depth of the active mixing layer in addition to supporting sediment sorting in previous research on symmetric oscillatory flows in which the larger grains collect on top of ripple crests and smaller grains in the troughs. Preliminary quantitative results illuminate variations in equilibrium ripple geometry, ripple migration rates, and transition time scales between equilibrium states, all as functions of the sediment size mixture and flow forcing.

A novel F-box protein CaF-box is involved in responses to plant hormones and abiotic stress in pepper (Capsicum annuum L.).

PubMed

Chen, Rugang; Guo, Weili; Yin, Yanxu; Gong, Zhen-Hui

2014-02-10

The F-box protein family is characterized by an F-box motif that has been shown to play an important role in regulating various developmental processes and stress responses. In this study, a novel F-box-containing gene was isolated from leaves of pepper cultivar P70 (Capsicum annuum L.) and designated CaF-box. The full-length cDNA is 2088 bp and contains an open reading frame of 1914 bp encoding a putative polypeptide of 638 amino acids with a mass of 67.8 kDa. CaF-box was expressed predominantly in stems and seeds, and the transcript was markedly upregulated in response to cold stress, abscisic acid (ABA) and salicylic acid (SA) treatment, and downregulated under osmotic and heavy metal stress. CaF-box expression was dramatically affected by salt stress, and was rapidly increased for the first hour, then sharply decreased thereafter. In order to further assess the role of CaF-box in the defense response to abiotic stress, a loss-of-function experiment in pepper plants was performed using a virus-induced gene silencing (VIGS) technique. Measurement of thiobarbituric acid reactive substances (TBARS) and electrolyte leakage revealed stronger lipid peroxidation and cell death in the CaF-box-silenced plants than in control plants, suggesting CaF-box plays an important role in regulating the defense response to abiotic stress resistance in pepper plants.

A Novel F-Box Protein CaF-Box Is Involved in Responses to Plant Hormones and Abiotic Stress in Pepper (Capsicum annuum L.)

PubMed Central

Chen, Rugang; Guo, Weili; Yin, Yanxu; Gong, Zhen-Hui

2014-01-01

The F-box protein family is characterized by an F-box motif that has been shown to play an important role in regulating various developmental processes and stress responses. In this study, a novel F-box-containing gene was isolated from leaves of pepper cultivar P70 (Capsicum annuum L.) and designated CaF-box. The full-length cDNA is 2088 bp and contains an open reading frame of 1914 bp encoding a putative polypeptide of 638 amino acids with a mass of 67.8 kDa. CaF-box was expressed predominantly in stems and seeds, and the transcript was markedly upregulated in response to cold stress, abscisic acid (ABA) and salicylic acid (SA) treatment, and downregulated under osmotic and heavy metal stress. CaF-box expression was dramatically affected by salt stress, and was rapidly increased for the first hour, then sharply decreased thereafter. In order to further assess the role of CaF-box in the defense response to abiotic stress, a loss-of-function experiment in pepper plants was performed using a virus-induced gene silencing (VIGS) technique. Measurement of thiobarbituric acid reactive substances (TBARS) and electrolyte leakage revealed stronger lipid peroxidation and cell death in the CaF-box-silenced plants than in control plants, suggesting CaF-box plays an important role in regulating the defense response to abiotic stress resistance in pepper plants. PMID:24518684

Conventional box model training improves laparoscopic skills during salpingectomy on LapSim: a randomized trial.

PubMed

Akdemir, Ali; Ergenoğlu, Ahmet Mete; Yeniel, Ahmet Özgür; Sendağ, Fatih

2013-01-01

Box model trainers have been used for many years to facilitate the improvement of laparoscopic skills. However, there are limited data available on box trainers and their impact on skill acquisition, assessed by virtual reality systems. Twenty-two Postgraduate Year 1 gynecology residents with no laparoscopic experience were randomly divided into one group that received structured box model training and a control group. All residents performed a salpingectomy on LapSim before and after the training. Performances before and after the training were assessed using LapSim and were recorded using objective parameters, registered by a computer system (time, damage, and economy of motion scores). There were initially no differences between the two groups. The box trainer group showed significantly greater improvement in time (p=0.01) and economy of motion scores (p=0.001) compared with the control group post-training. The present study confirmed the positive effect of low cost box model training on laparoscopic skill acquisition as assessed using LapSim. Novice surgeons should obtain practice on box trainers and teaching centers should make efforts to establish training laboratories.

Blind Inlet as a Possible Technology for the Remediation of Phosphorus from Surface Runoff

NASA Astrophysics Data System (ADS)

Sturmlechner, M.; Wu, X.; Livingston, S.; Klik, A.; Huang, C. H.

2015-12-01

Phosphorus (P) is an essential element for plant life, but too much P in runoff water can cause eutrophication and harmful algal blooms. Hence, mitigation of agricultural P losses into the water cycle is a very important issue. In-stream P treatment is difficult to implement because the large amount of storm runoff needs to be treated in short durations. In this research, we evaluated the potential to use blind inlet as an in-field P treatment technology. A box system was built to simulate hydrological and chemical processes occurring in a blind inlet. Current blind inlets, which are already installed in the field, use a bed of limestone with a sand/pea gravel layer on the top. In this study, steel slags has been tested, which has a very high P sorption potential, as the filter media through a series of adsorption and desorption experiments. The P mass balance results are compared with the limestone material used in current blind inlet construction. The total mass of P which was absorbed by the limestone was 14 % of the P input into the system whereas 26 % P was absorbed by the steel slags. Therefore the steel slags show potential to sequester dissolved P. Additional research is on-going to come up with a design criteria for field implementation.

The behavior of self-compacting concrete (SCC) with bagasse ash

NASA Astrophysics Data System (ADS)

Hanafiah, Saloma, Whardani, Putri Nurul Kusuma

2017-11-01

Self-Compacting Concrete (SCC) has the ability to flow and self-compacting. One of the benefit of SCC can reduced the construction time and labor cost. The materials to be used for see slightly different with the conventional concrete. Less coarse aggregate to be used up to 50%. The maximum size of coarse aggregate was also limited e.g. 10 mm. Other material was quartz sand with grain size of 50-650 µm. For reducing the around of cement, bagasse ash was used as partial replacement of cement. In this research, the variations of w/c to be used, e.g. 0.275, 0.300, 0.325 and the percentage of bagasse ash substitution were 10%, 15%, and 20%. EFNARC standard was conducted for slump flow test following the V-funnel test and L-box shape test. The maximum value of slump flow test was 75.75 cm, V-funnel test was 4.95 second, and L-box test was 1.000 yielded by mixture with w/c = 0.325 and 0% of bagasse ash. The minimum value of slump flow test was 61.50 cm, V-funnel test is 21.05 second, and L-box test was 0.743 yielded by mixture with w/c = 0.275 and 20% of bagasse ash. The maximum value of compressive strength was 67.239 MPa yielded by mixture with w/c = 0.275 and 15% of bagasse ash. And the minimum value of compressive strength was 41.813 MPa yielded by mixture with w/c = 0.325 and 20% bagasse ash.

Factors influencing the natural regeneration of the pioneering shrub Calligonum mongolicum in sand dune stabilization plantations in arid deserts of northwest China.

PubMed

Fan, Baoli; McHugh, Allen David; Guo, Shujiang; Ma, Quanlin; Zhang, Jianhui; Zhang, Xiaojuan; Zhang, Weixing; Du, Juan; Yu, Qiushi; Zhao, Changming

2018-03-01

Calligonum mongolicum is a successful pioneer shrub to combat desertification, which is widely used for vegetation restoration in the desert regions of northwest China. In order to reveal the limitations to natural regeneration of C. mongolicum by asexual and sexual reproduction, following the process of sand dune stabilization, we assessed clonal shoots, seedling emergence, soil seed bank density, and soil physical characteristics in mobile and stabilized sand dunes. Controlled field and pot experiments were also conducted to assess germination and seedling emergence in different dune soil types and seed burial depths. The population density of mature C. mongolicum was significantly different after sand dune stabilization. Juvenile density of C. mongolicm was much lower in stabilized sand dunes than mobile sand dune. There was no significant difference in soil seed bank density at three soil depths between mobile and stabilized sand dunes, while the emergence of seedlings in stabilized dunes was much lower than emergence in mobile dunes. There was no clonal propagation found in stabilized dunes, and very few C. mongolicum seedlings were established on stabilized sand dunes. Soil clay and silt content, air-filled porosity, and soil surface compaction were significantly changed from mobile sand dune to stabilized dunes. Seedling emergence of C. mongolicm was highly dependent on soil physical condition. These results indicated that changes in soil physical condition limited clonal propagation and seedling emergence of C. mongolicum in stabilized sand dunes. Seed bank density was not a limiting factor; however, poor seedling establishment limited C. mongolicum's further natural regeneration in stabilized sand dunes. Therefore, clonal propagation may be the most important mode for population expansion in mobile sand dunes. As a pioneer species C. mongolicum is well adapted to propagate in mobile sand dune conditions, it appears unlikely to survive naturally in stabilized sand dune plantations.

Sand transportation and reverse patterns over leeward face of sand dune

NASA Astrophysics Data System (ADS)

Jiang, Hong; Dun, Hongchao; Tong, Ding; Huang, Ning

2017-04-01

Sand saltation has complex interactions with turbulent flow and dune form. Most models of wind-blown sand consider ideal circumstances such as steady wind velocity and a flat surface, and the bulk of data on wind flow and sand transport over an individual dune has focused mostly on the influence of dune shape or inter-dune space on the wind flow, neglecting the effect of morphology on sand saltation, particularly airflow and sand transportation over the leeward slope. Wind flow structures over the leeward slope of sand dunes have a fundamental influence on the organization of sand dunes. In order to understand sand dune dynamics, lee face airflow and sediment transportation should be paid more attention. Previous field observations could not measure turbulent flow structure well because of the limited observation points and the influence of experiment structure on wind field. In addition, the reverse sand particles over leeward face could not be collected by sand trap in field. Numerous field observations could not measure turbulent flow structure because of the limited observation points and the influence of experimental structures on the wind field. In addition, the reverse transport of sand particles over leeward face could not be collected by sand traps in field. Therefore, this paper aims to investigate the turbulent flow structure and sand transport pattern over the leeward slope. A numerical model of sand saltation over slope terrain is constructed, which also considers the coupling effects between air flow and sand particles. The large eddy simulation method is used to model turbulent flow. Sand transport is simulated by tracking the trajectory of each sand particle. The results show that terrain significantly alters the turbulent air flow structure and wind-blown sand movement, especially over the leeward slope. Here, mass flux increases initially and then decreases with height in the reversed flow region in the direction of wind flow, and the mass flux decreases with height in the reversed direction. The height of 0.5 H is the height of vortex core in the reversed flow region. The vortex core is a critical point in the flow region where few particles are transited. In the reversed region, the reversed mass flux of sand particles is 25% of the mass flux in the flow direction. This research may contribute to scientific understanding of the mechanisms of sand motion and wind flow over leeward of dune and it is likely to be significant in desertification control.

How does the wetting dynamics affect capillary trapping in heterogeneous soil: Neutron imaging study

NASA Astrophysics Data System (ADS)

Sacha, Jan; Snehota, Michal; Trtik, Pavel; Vontobel, Peter

2017-04-01

The wetting dynamics of the water infiltration into a porous soil system has a strong influence on the amount of entrapped air inside the soil. Simultaneously, a higher volume of entrapped air obstructs a water flow in the medium. This effect is more noticeable in soils with preferential pathways because the soil matrix has a higher capillary forces and therefore the air is accumulated in preferential pathways. In the presented study, two experiments were conducted on the same sample. The first experiment was performed under the constant water level condition (CWL) and the second experiment was carried out under the constant water flux condition (CWF) at the top of the sample. The sample was composed of coarse and medium coarse fractions of sand and fine porous ceramics. Materials were packed into the quartz glass column of the inner diameter of 29 mm. The coarse sand represented a highly conductive region connected from the top to the bottom of the sample with the exception of three thin (2-3 mm) separation layers made up of the medium coarse sand. Three discs of fine ceramics formed slow flow regions. Infiltration experiments were monitored by neutron radiography at two different beamlines to produce two-dimensional (2D) projections. The CWL experiment was monitored at NEUTRA station with an acquisition time of 16 seconds per projection and the CWF experiment was visualized at BOA station with an acquisition time of 0.25 seconds per projection. Both stations are located at the Paul Scherrer Institut, Switzerland. The acquired radiograms of the dry sample were subtracted from all subsequent radiograms to determine the water thickness in projections. From series of corrected radiograms taken at the different angles three-dimensional (3D) image was reconstructed for steady state stage of the CWL experiment and for the entire CWF experiment. Then the series of 3D images mapped the wetting of the porous system over the corresponding phase of infiltration process. The results show a higher steady state infiltration rate during the CWL experiment. In this case, the air was mostly pushed out from the sample by the moving wetting front. The infiltration rate was continuously decreasing during the infiltration up to the value of steady state infiltration rate. When the wetting front has reached the bottom of the sample the air was moving from matrix domain to preferential domain. Infiltration rate was still higher than during CWF. On the contrary, during the CWF the water infiltrated into the fine ceramics first and then into the medium coarse sand attracted by forces that were stronger in comparison to the coarse sand. Due to this effect a significant amount of air was trapped in preferential pathways, and consequently blocked the water flow primarily due to the presence of medium coarse sand regions.

A New Set of ESTs from Chickpea (Cicer arietinum L.) Embryo Reveals Two Novel F-Box Genes, CarF-box_PP2 and CarF-box_LysM, with Potential Roles in Seed Development

PubMed Central

Gupta, Shefali; Garg, Vanika; Bhatia, Sabhyata

2015-01-01

Considering the economic importance of chickpea (C. arietinum L.) seeds, it is important to understand the mechanisms underlying seed development for which a cDNA library was constructed from 6 day old chickpea embryos. A total of 8,186 ESTs were obtained from which 4,048 high quality ESTs were assembled into 1,480 unigenes that majorly encoded genes involved in various metabolic and regulatory pathways. Of these, 95 ESTs were found to be involved in ubiquitination related protein degradation pathways and 12 ESTs coded specifically for putative F-box proteins. Differential transcript accumulation of these putative F-box genes was observed in chickpea tissues as evidenced by quantitative real-time PCR. Further, to explore the role of F-box proteins in chickpea seed development, two F-box genes were selected for molecular characterization. These were named as CarF-box_PP2 and CarF-box_LysM depending on their C-terminal domains, PP2 and LysM, respectively. Their highly conserved structures led us to predict their target substrates. Subcellular localization experiment revealed that CarF-box_PP2 was localized in the cytoplasm and CarF-box_LysM was localized in the nucleus. We demonstrated their physical interactions with SKP1 protein, which validated that they function as F-box proteins in the formation of SCF complexes. Sequence analysis of their promoter regions revealed certain seed specific cis-acting elements that may be regulating their preferential transcript accumulation in the seed. Overall, the study helped in expanding the EST database of chickpea, which was further used to identify two novel F-box genes having a potential role in seed development. PMID:25803812

Mental Rotation in False Belief Understanding.

PubMed

Xie, Jiushu; Cheung, Him; Shen, Manqiong; Wang, Ruiming

2018-05-01

This study examines the spontaneous use of embodied egocentric transformation (EET) in understanding false beliefs in the minds of others. EET involves the participants mentally transforming or rotating themselves into the orientation of an agent when trying to adopt his or her visuospatial perspective. We argue that psychological perspective taking such as false belief reasoning may also involve EET because of what has been widely reported in the embodied cognition literature, showing that our processing of abstract, propositional information is often grounded in concrete bodily sensations which are not apparently linked to higher cognition. In Experiment 1, an agent placed a ball into one of two boxes and left. The ball then rolled out and moved either into the other box (new box) or back into the original one (old box). The participants were to decide from which box they themselves or the agent would try to recover the ball. Results showed that false belief performance was affected by increased orientation disparity between the participants and the agent, suggesting involvement of embodied transformation. In Experiment 2, false belief was similarly induced and the participants were to decide if the agent would try to recover the ball in one specific box. Orientation disparity was again found to affect false belief performance. The present results extend previous findings on EET in visuospatial perspective taking and suggest that false belief reasoning, which is a kind of psychological perspective taking, can also involve embodied rotation, consistent with the embodied cognition view. Copyright © 2018 Cognitive Science Society, Inc.

Varying Inundation Regimes Differentially Affect Natural and Sand-Amended Marsh Sediments.

PubMed

Wigand, C; Sundberg, K; Hanson, A; Davey, E; Johnson, R; Watson, E; Morris, J

2016-01-01

Climate change is altering sea level rise rates and precipitation patterns worldwide. Coastal wetlands are vulnerable to these changes. System responses to stressors are important for resource managers and environmental stewards to understand in order to best manage them. Thin layer sand or sediment application to drowning and eroding marshes is one approach to build elevation and resilience. The above- and below-ground structure, soil carbon dioxide emissions, and pore water constituents in vegetated natural marsh sediments and sand-amended sediments were examined at varying inundation regimes between mean sea level and mean high water (0.82 m NAVD88 to 1.49 m NAVD88) in a field experiment at Laws Point, part of the Plum Island Sound Estuary (MA). Significantly lower salinities, pH, sulfides, phosphates, and ammonium were measured in the sand-amended sediments than in the natural sediments. In natural sediments there was a pattern of increasing salinity with increasing elevation while in the sand-amended sediments the trend was reversed, showing decreasing salinity with increasing elevation. Sulfide concentrations generally increased from low to high inundation with highest concentrations at the highest inundation (i.e., at the lowest elevations). High pore water phosphate concentrations were measured at low elevations in the natural sediments, but the sand-amended treatments had mostly low concentrations of phosphate and no consistent pattern with elevation. At the end of the experiment the lowest elevations generally had the highest measures of pore water ammonium. Soil carbon dioxide emissions were greatest in the sand-amended mesocosms and at higher elevations. Differences in coarse root and rhizome abundances and volumes among the sediment treatments were detected with CT imaging, but by 20 weeks the natural and sand-amended treatments showed similar total belowground biomass at the intermediate and high elevations. Although differences in pore water nutrient concentrations, pH, salinity, and belowground root and rhizome morphology were detected between the natural and sand-amended sediments, similar belowground productivity and total biomass were measured by the end of the growing season. Since the belowground productivity supports organic matter accumulation and peat buildup in marshes, our results suggest that thin layer sand or sediment application is a viable climate adaptation action to build elevation and coastal resiliency, especially in areas with low natural sediment supplies.

Abrasion by aeolian particles: Earth and Mars

NASA Technical Reports Server (NTRS)

Greeley, R.; Marshall, J. R.; White, B. R.; Pollack, J. B.; Marshall, J.; Krinsley, D.

1984-01-01

Estimation of the rate of aeolian abrasion of rocks on Mars requires knowledge of: (1) particle flux, (2) susceptibilities to abrasion of various rocks, and (3) wind frequencies on Mars. Fluxes and susceptibilities for a wide range of conditions were obtained in the laboratory and combined with wind data from the Viking meteorology experiment. Assuming an abundant supply of sand-sized particles, estimated rates range up to 2.1 x 10 to the minus 2 power cm of abrasion per year in the vicinity of Viking Lander 1. This rate is orders of magnitude too great to be in agreement with the inferred age of the surface based on models of impact crater flux. The discrepancy in the estimated rate of abrasion and the presumed old age of the surface cannot be explained easily by changes in climate or exhumation of ancient surfaces. The primary reason is thought to be related to the agents of abrasion. At least some sand-sized (approx. 100 micrometers) grains appear to be present, as inferred from both lander and orbiter observations. High rates of abrasion occur for all experimental cases involving sands of quartz, basalt, or ash. However, previous studies have shown that sand is quickly comminuted to silt- and clay-sized grains in the martian aeolian regime. Experiments also show that these fine grains are electrostatically charged and bond together as sand-sized aggregates. Laboratory simulations of wind abrasion involving aggregates show that at impact velocities capable of destroying sand, aggregates from a protective veneer on the target surface and can give rise to extremely low abrasion rates.

A New Sand-Culture Apparatus for Tree Nutrition Research

Treesearch

B. G. Blackmon; N. E. Linnartz

1970-01-01

Research in tree nutrition often necessitates the use of rather large-scale installations of sand-culture equipment. The apparatus described below was developed during the course of experiments at Louisiana State University and provided daily irrigation to 102 culture units of loblolly pine (Pinus taeda L.) for a period of 10 months. This apparatus is a modification of...

LARGE-SCALE NATURAL GRADIENT TRACER TEST IN SAND AND GRAVEL, CAPE COD, MASSACHUSETTS - 1. EXPERIMENTAL DESIGN AND OBSERVED TRACER MOVEMENT

EPA Science Inventory

A large-scale natural gradient tracer experiment was conducted on Cape Cod, Massachusetts, to examine the transport and dispersion of solutes in a sand and gravel aquifer. The nonreactive tracer, bromide, and the reactive tracers, lithium and molybdate, were injected as a pulse i...

Breeding system and its consequence on fruit set of a rare sand dune shrub Eremosparton songoricum (Fabaceae: Papilionoideae): implications for conservation

USDA-ARS?s Scientific Manuscript database

The breeding system and its consequence on fruit set of Eremosparton songoricum (Litv.) Vass., a rare shrubby legume occurring in moving or semi-fixed sand dunes of Central Asian deserts, were examined by manipulative experiments and observational studies in natural populations during the period of ...

Earthquake Engineering Support

DTIC Science & Technology

1999-11-01

recovered from eql 3c 7 525 49% loose 79% dense 2 5/5/98 1 3 Nevada sand, ESB #2 3d 11 525 54% loose 80% dense 2 3/9/98 2.5 4 Nevada sand, ESB #2 3e...The pore pressure transducers used in the experiments were manufactured by Druck , and are widely used in centrifuge modelling. Typical

Contrafreeloading in grizzly bears: implications for captive foraging enrichment.

PubMed

McGowan, Ragen T S; Robbins, Charles T; Alldredge, J Richard; Newberry, Ruth C

2010-01-01

Although traditional feeding regimens for captive animals were focused on meeting physiological needs to assure good health, more recently emphasis has also been placed on non-nutritive aspects of feeding. The provision of foraging materials to diversify feeding behavior is a common practice in zoos but selective consumption of foraging enrichment items over more balanced "chow" diets could lead to nutrient imbalance. One alternative is to provide balanced diets in a contrafreeloading paradigm. Contrafreeloading occurs when animals choose resources that require effort to exploit when identical resources are freely available. To investigate contrafreeloading and its potential as a theoretical foundation for foraging enrichment, we conducted two experiments with captive grizzly bears (Ursus arctos horribilis). In Experiment 1, bears were presented with five foraging choices simultaneously: apples, apples in ice, salmon, salmon in ice, and plain ice under two levels of food restriction. Two measures of contrafreeloading were considered: weight of earned food consumed and time spent working for earned food. More free than earned food was eaten, with only two bears consuming food extracted from ice, but all bears spent more time manipulating ice containing salmon or apples than plain ice regardless of level of food restriction. In Experiment 2, food-restricted bears were presented with three foraging choices simultaneously: apples, apples inside a box, and an empty box. Although they ate more free than earned food, five bears consumed food from boxes and all spent more time manipulating boxes containing apples than empty boxes. Our findings support the provision of contrafreeloading opportunities as a foraging enrichment strategy for captive wildlife. (c) 2009 Wiley-Liss, Inc.

Bacterial transport in heterogeneous porous media: Observations from laboratory experiments

NASA Astrophysics Data System (ADS)

Silliman, S. E.; Dunlap, R.; Fletcher, M.; Schneegurt, M. A.

2001-11-01

Transport of bacteria through heterogeneous porous media was investigated in small-scale columns packed with sand and in a tank designed to allow the hydraulic conductivity to vary as a two-dimensional, lognormally distributed, second-order stationary, exponentially correlated random field. The bacteria were Pseudomonas ftuorescens R8, a strain demonstrating appreciable attachment to surfaces, and strain Ml, a transposon mutant of strain R8 with reduced attachment ability. In bench top, sand-filled columns, transport was determined by measuring intensity of fluorescence of stained cells in the effluent or by measuring radiolabeled cells that were retained in the sand columns. Results demonstrated that strain Ml was transported more efficiently than strain R8 through columns packed with either a homogeneous silica sand or a more heterogeneous sand with iron oxide coatings. Two experiments conducted in the tank involved monitoring transport of bacteria to wells via sampling from wells and sample ports in the tank. Bacterial numbers were determined by direct plate count. At the end of the first experiment, the distribution of the bacteria in the sediment was determined by destructive sampling and plating. The two experiments produced bacterial breakthrough curves that were quite similar even though the similarity between the two porous media was limited to first- and second-order statistical moments. This result appears consistent with the concept of large-scale, average behavior such as has been observed for the transport of conservative chemical tracers. The transported bacteria arrived simultaneously with a conservative chemical tracer (although at significantly lower normalized concentration than the tracer). However, the bacterial breakthrough curves showed significant late time tailing. The concentrations of bacteria attached to the sediment surfaces showed considerably more spatial variation than did the concentrations of bacteria in the fluid phase. This contrast between behavior in the fluid phase and on the solids is consistent with field observations by other authors and initial modeling of these heterogeneous media.

Experimental investigations regarding the use of sand as an inhibitor of air convection in deep seismic boreholes

USGS Publications Warehouse

Holcomb, L. Gary; Sandoval, Leo; Hutt, Bob

1998-01-01

Tilt has been the nemesis of horizontal long period seismology since its inception. Modern horizontal long period seismometers with their long natural periods are incredibly sensitive to tilt. They can sense tilts smaller than 10-11 radians. To most readers, this is just a very very small number, so we will begin with an example, which should help to illustrate just how small 10-11 radians is.Suppose we have an absolutely rigid rod which is approximately 4170 kilometers long; this just happens to be the Rand McNally map scaled crow flight distance between Los Angeles and Boston. Tilting this rod 10-11 radians corresponds to raising one end of the rod 0.0000417 meters. Alas, this is just another very very small number! However, this corresponds to slipping a little less than one third a sheet of ordinary copying paper under one end of this perfectly rigid rod. To clarify, we mean, take a sheet of paper just like the paper this report is printed on and split it a little less than one third in the thickness direction, then put it under the end of the 4170 kilometer long rod! This will tilt the rod 10-11 radians.Real world seismometers are nowhere near the length of this rod. A KS-54000 is about two meters long. Tilting a rod only two meters long 10~n radians corresponds to moving one end of this rod a mere 0.00000000002 meters or 0.02 millimicrons. As one of the authors old math teachers used to say, "That's PDS" (PDS = Pretty Damn Small). Unfortunately, the long period seismologist does not have the luxury of ignoring PDS numbers when it suits him as the mathematician frequently does. He must live in the real world in which tilts this small create severe contamination of long period seismic data.At periods longer than 20 seconds, tilt noise contaminates the long period data from all instruments installed on or near the earth's surface. Many years of experimentation revealed that installing the sensors at depth in deep mines drastically reduced the level of tilt noise in long period data. However, low levels of tilt noise persisted even at great depth; this noise was caused by air convection in the vault in which the sensors were installed. Over the years, methods were developed to control the air motion with mechanical barriers (boxes) around the sensors and by stratifying (creating a situation in which the air temperature increases with height) the air in the vault near the seismometer. These methods decreased tilt noise in deep mines to very low levels. However, deep mines, that are economically and environmentally suitable and accessible to seismology, are not plentiful and are not evenly distributed over the earth's surface. Therefore, the borehole deployable Teledyne Geotech KS-36000 and later the KS-54000 sensor systems were developed to fulfill the need for instruments that could be installed at depth wherever high quality long period data was desired. Early in the development program, it became evident to the Teledyne Geotech personnel that air convection within the borehole was going to be a significant problem in KS deployments. Experimental and theoretical investigations conducted by Teledyne Geotech (see Douze and Sherwin, 1975, and Sherwin and Cook, 1976) produced a list of recommended installation procedures for reducing the effects of air convection. These procedures consisted of wrapping the sensor in a relatively thin layer of foam insulation, filling the free space volume in the vicinity of the centralizer-bail assembly with foam insulation, and the installation of styrofoam hole plugs immediately above the cable strain relief assembly at the top of the sensor package and at the top of the borehole. This technology has performed quite satisfactorily for over 20 years but evidence of tilt noise in the system output has persisted throughout the KS deployment program (the evidence was that the horizontal components were usually noisier than the vertical components) even in deep boreholes. Some deep borehole sites have been plagued by quite high levels of horizontal noise. Therefore, there has been a definite need for a new technique for controlling low level tilt noise in deep boreholes and the use of sand has been under consideration for several years.Figure 1 contains conceptual illustrations of both the conventional holelock installed KS sensor system and the same sensor installed in sand. This figure demonstrates the major differences between the two installation methods. The curved arrows in the borehole on the left in the figure denote possible air convection cells which are believed to be the source of tilt noise in some of the conventional installations. This air motion is eliminated in a sand installation by filling most of the free air volume surrounding the seismometer with sand as shown in the right hand portion of the figure. The sand actually performs two functions; it prevents air motion and provides a remarkably ridgid clamping of the seismometer in the borehole. This report presents the results of quantitative experimental investigations into the effectiveness of controlling low level air convection in seismic borehole installations with sand. The main body of the experimental effort consisted of installing two KS-540001 sensor systems in closely spaced shallow boreholes, allowing the sensors to reach equilibrium operation, and then pouring sand into both boreholes to observe any changes caused by pouring sand into the holes. The hypothesis of the experiment was that the sand would fill up the entire free air volume between the sensor package and the borehole walls thereby preventing movement of the air in the vicinity of the sensor package. The validity of this hypothesis had been qualitatively proven by earlier experiments at ASL and by the sand installations at the IRIS/ASL stations ANMO in 1995 and COLA in 1996. This experiment documents the degree of improved noise levels to be expected if KS instruments are installed in sand instead of in the conventional manner.

Five-month-old infants have expectations for the accumulation of nonsolid substances.

PubMed

Anderson, Erin M; Hespos, Susan J; Rips, Lance J

2018-06-01

Infants fail to represent quantities of non-cohesive substances in paradigms where they succeed with solid objects. Some investigators have interpreted these results as evidence that infants do not yet have representations for substances. More recent research, however, shows that 5-month-old infants expect objects and substances to behave and interact in different ways. In the present experiments, we test whether infants have expectations for substances when the outcomes are not simply the opposite of those for objects. In Experiment 1, we find that 5-month-old infants expect that when a cup of sand pours behind a screen, it will accumulate in just one pile rather than two. Similarly, infants expect that when two cups of sand pour in separate streams, two distinct piles will accumulate rather than one. Infants look significantly longer at outcomes with an inconsistent number of piles, providing evidence that infants have expectations for how sand accumulates. To test whether the number of cups or the number of pours guided expectations about accumulation, Experiment 2 placed these cues in conflict. This resulted in chance performance, suggesting that, for infants to build expectations about these outcomes, they need both cues (cup and pour) to converge. These findings offer insight into the nature of infants' representations for non-cohesive substances like sand. Copyright © 2018 Elsevier B.V. All rights reserved.

Does denitrification occur within porous carbonate sand grains?

NASA Astrophysics Data System (ADS)

Miall Cook, Perran Louis; Kessler, Adam John; Eyre, Bradley David

2017-09-01

Permeable carbonate sands form a major habitat type on coral reefs and play a major role in organic matter recycling. Nitrogen cycling within these sediments is likely to play a major role in coral reef productivity, yet it remains poorly studied. Here, we used flow-through reactors and stirred reactors to quantify potential rates of denitrification and the dependence of denitrification on oxygen concentrations in permeable carbonate sands at three sites on Heron Island, Australia. Our results showed that potential rates of denitrification fell within the range of 2-28 µmol L-1 sediment h-1 and were very low compared to oxygen consumption rates, consistent with previous studies of silicate sands. Denitrification was observed to commence at porewater oxygen concentrations as high as 50 µM in stirred reactor experiments on the coarse sediment fraction (2-10 mm) and at oxygen concentrations of 10-20 µM in flow-through and stirred reactor experiments at a site with a median sediment grain size of 0.9 mm. No denitrification was detected in sediments under oxic conditions from another site with finer sediment (median grain size: 0.7 mm). We interpret these results as confirmation that denitrification may occur within anoxic microniches present within porous carbonate sand grains. The occurrence of such microniches has the potential to enhance denitrification rates within carbonate sediments; however further work is required to elucidate the extent and ecological significance of this effect.

Investigation the Effect of the Dispersant Corexit 9500A on the Movement of an Oil-In-Water Emulsion Through an Alabama Beach Sand

NASA Astrophysics Data System (ADS)

Steffy, D. A.; Nichols, A.

2016-02-01

A majority of Alabama's 60 miles of beaches were exposed to the crude oil released from the massive 2010 Deepwater Horizon Oil Spill. To help remediate the spill BP sprayed the dispersant, COREXIT 9500A, over the floating oil in the Gulf and at the subsurface damaged Macondo wellhead. This dispersant could have inadvertently promoted an oil-in-water emulsion to infiltrate deeper into the exposed beaches which are composed of Holocene age, fine-to-medium quartz sand. A series of short-column tests of packed sand in glass columns simulated the arrival of an oil-in-water emulsion at a beach. An emulsion formed by weathered oil penetrated deeper into the sand as compared to oil that has experience little weathering. The penetrations of these emulsions were enhanced when a 2% COREXIT 9500A in saltwater solution was allowed to flush through the sand column. Unfortunately, by adding a dispersant it probably promoted some oil-in-water components to be distributed deeper into coastal sand of Alabama.

Replicating the microbial community and water quality performance of full-scale slow sand filters in laboratory-scale filters.

PubMed

Haig, Sarah-Jane; Quince, Christopher; Davies, Robert L; Dorea, Caetano C; Collins, Gavin

2014-09-15

Previous laboratory-scale studies to characterise the functional microbial ecology of slow sand filters have suffered from methodological limitations that could compromise their relevance to full-scale systems. Therefore, to ascertain if laboratory-scale slow sand filters (L-SSFs) can replicate the microbial community and water quality production of industrially operated full-scale slow sand filters (I-SSFs), eight cylindrical L-SSFs were constructed and were used to treat water from the same source as the I-SSFs. Half of the L-SSFs sand beds were composed of sterilized sand (sterile) from the industrial filters and the other half with sand taken directly from the same industrial filter (non-sterile). All filters were operated for 10 weeks, with the microbial community and water quality parameters sampled and analysed weekly. To characterize the microbial community phyla-specific qPCR assays and 454 pyrosequencing of the 16S rRNA gene were used in conjunction with an array of statistical techniques. The results demonstrate that it is possible to mimic both the water quality production and the structure of the microbial community of full-scale filters in the laboratory - at all levels of taxonomic classification except OTU - thus allowing comparison of LSSF experiments with full-scale units. Further, it was found that the sand type composing the filter bed (non-sterile or sterile), the water quality produced, the age of the filters and the depth of sand samples were all significant factors in explaining observed differences in the structure of the microbial consortia. This study is the first to the authors' knowledge that demonstrates that scaled-down slow sand filters can accurately reproduce the water quality and microbial consortia of full-scale slow sand filters. Copyright © 2014 Elsevier Ltd. All rights reserved.

Draw-a-Scientist/Mystery Box Redux

ERIC Educational Resources Information Center

Cavallo, Ann

2007-01-01

It is important that students have the opportunity to experience the nature and processes of science for themselves. The sequence of activities presented in this paper--Draw-a-Scientist and the Mystery Box Redux--were designed to help students better understand the nature of science (NOS) and engage them in the process of scientific inquiry. These…

Soil carbon changes: comparing flux monitoring and mass balance in a box lysimeter experiment.

Treesearch

S.M. Nay; B.T. Bormann

2000-01-01

Direct measures of soil-surface respiration are needed to evaluate belowground biological processes, forest productivity, and ecosystem responses to global change. Although infra-red gas analyzer {IRGA) methods track reference CO2 flows in lab studies, questions remain for extrapolating IRGA methods to field conditions. We constructed 10 box...

Exploring Beginning Inference with Novice Grade 7 Students

ERIC Educational Resources Information Center

Watson, Jane M.

2008-01-01

This study documented efforts to facilitate ideas of beginning inference in novice grade 7 students. A design experiment allowed modified teaching opportunities in light of observation of components of a framework adapted from that developed by Pfannkuch for teaching informal inference with box plots. Box plots were replaced by hat plots, a…

Conjunctive Management of Multi-Aquifer System for Saltwater Intrusion Mitigation

NASA Astrophysics Data System (ADS)

Tsai, F. T. C.; Pham, H. V.

2015-12-01

Due to excessive groundwater withdrawals, many water wells in Baton Rouge, Louisiana experience undesirable chloride concentration because of saltwater intrusion. The study goal is to develop a conjunctive management framework that takes advantage of the Baton Rouge multi-aquifer system to mitigate saltwater intrusion. The conjunctive management framework utilizes several hydraulic control techniques to mitigate saltwater encroachment. These hydraulic control approaches include pumping well relocation, freshwater injection, saltwater scavenging, and their combinations. Specific objectives of the study are: (1) constructing scientific geologic architectures of the "800-foot" sand, the "1,000-foot" sand, the "1,200-foot" sand, the "1,500-foot" sand, the "1,700-foot" sand, and the "2,000-foot" sand, (2) developing scientific saltwater intrusion models for these sands. (3) using connector wells to draw native groundwater from one sand and inject to another sand to create hydraulic barriers to halt saltwater intrusion, (4) using scavenger wells or well couples to impede saltwater intrusion progress and reduce chloride concentration in pumping wells, and (5) reducing cones of depression by relocating and dispersing pumping wells to different sands. The study utilizes optimization techniques and newest LSU high performance computing (HPC) facilities to derive solutions. The conjunctive management framework serves as a scientific tool to assist policy makers to solve the urgent saltwater encroachment issue in the Baton Rouge area. The research results will help water companies as well as industries in East Baton Rouge Parish and neighboring parishes by reducing their saltwater intrusion threats, which in turn would sustain Capital Area economic development.

Study Gradation and Moisture Content of Sand Embankment on Peat Subjected Vibration Potential Liquefaction

NASA Astrophysics Data System (ADS)

Agus Nugroho, Soewignjo; Ika Putra, Agus; Yusa, Muhamad

2018-03-01

In recent years large earthquakes often occur on the island of Sumatra. There is a phenomenon of the damage occurred during the earthquake, one of the effects is a phenomenon of loss of soil strength due to vibration called liquefaction. Some cases of liquefaction occur in some areas in Aceh, Nias Island, Padang and Pariaman. Pekanbaru is located close to the fault area that causes the occurrence of earthquake wave propagation. Pekanbaru are also at risk for geotechnical problems because of earthquake such as liquefaction. Evaluation of liquefaction potential could using by in-situ test and by laboratory test. The laboratory test to evaluation liquefaction potential among which method of experiment shaking table. In this study, liquefaction phenomenon was conducted by creating a physical model of a laboratory scale using a one-way vibration machine, with a review of how big the influence of sand gradation, sand shaped and grain-size, and surface water level in the sand against liquefaction potential. Evaluate of liquefaction potential based on the surface reading of the soil movement, elapsed time for final settlement and an excess pore water dissipation (EPD) during testing. Based on the results of performed test, indicated that fine sand on fully saturated conditions have the potential of maximum settlement for 20.67% and maximum ascend of pore water for 46.67%. This result mean that poorly graded fine sand on fully saturated conditions has more liquefaction potential than medium sand, coarse sand, and well graded sand

Colorado River sediment transport: 2. Systematic bed‐elevation and grain‐size effects of sand supply limitation

USGS Publications Warehouse

Topping, David J.; Rubin, David M.; Nelson, Jonathan M.; Kinzel, Paul J.; Corson, Ingrid C.

2000-01-01

The Colorado River in Marble and Grand Canyons displays evidence of annual supply limitation with respect to sand both prior to [Topping et al, this issue] and after the closure of Glen Canyon Dam in 1963. Systematic changes in bed elevation and systematic coupled changes in suspended‐sand concentration and grain size result from this supply limitation. During floods, sand supply limitation either causes or modifies a lag between the time of maximum discharge and the time of either maximum or minimum (depending on reach geometry) bed elevation. If, at a cross section where the bed aggrades with increasing flow, the maximum bed elevation is observed to lead the peak or the receding limb of a flood, then this observed response of the bed is due to sand supply limitation. Sand supply limitation also leads to the systematic evolution of sand grain size (both on the bed and in suspension) in the Colorado River. Sand input during a tributary flood travels down the Colorado River as an elongating sediment wave, with the finest sizes (because of their lower settling velocities) traveling the fastest. As the fine front of a sediment wave arrives at a given location, the bed fines and suspended‐sand concentrations increase in response to the enhanced upstream supply of finer sand. Then, as the front of the sediment wave passes that location, the bed is winnowed and suspended‐sand concentrations decrease in response to the depletion of the upstream supply of finer sand. The grain‐size effects of depletion of the upstream sand supply are most obvious during periods of higher dam releases (e.g., the 1996 flood experiment and the 1997 test flow). Because of substantial changes in the grain‐size distribution of the bed, stable relationships between the discharge of water and sand‐transport rates (i.e., stable sand rating curves) are precluded. Sand budgets in a supply‐limited river like the Colorado River can only be constructed through inclusion of the physical processes that couple changes in bed‐sediment grain size to changes in sand‐transport rates.

Land Desertification and it’s Control in Gonghe Basin of Qinghai Plateau, China

NASA Astrophysics Data System (ADS)

Zhang, D.; Gao, S.; Lu, R.

2009-12-01

Land desertification is an important environmental and social-economic problems that threatening people’s living conditions and impacting social sustainable development. The Gonghe basin in Qinghai Plateau is a fragile cold alpine area which is one of the places seriously threatened by desertification in China. This paper selected Gonghe basin as a study area to study land sandy desertification and its controlling measures. The engineering measures for sandy desertification control include setting clay sand barrier, Salix cheilophila sand barrier, Tamarix sand barrier, Artemisia sand barrier and straw-checker sand-barriers to fix dunes; the biological measures include closure for natural vegetation recovery, direct seeding forestation, transplanting seedlings, and so on. The combination of engineering and biologic measures can fix dunes 2~3 years earlier than the common single measure; and the costs were basically identical. A synthesized evaluation system established based on experimental results and experience in recent years indicated that the effectiveness of the four kinds of sand barrier for prevention and control of sand in study area were: Tamarix sand barrier > Artemisia sand barrier > clay sand barrier > straw-checker sand-barriers. In addition, different optimized management model can be selected according to local material and geographical place. New plants such as Salix cheilophila and Tamarix, which are available in study area, can change from dead sand barrier to live one set in proper seasons, changing engineering measure to biological one directly speeds the progress of forestation and dunes fixation. In addition, we developed new technique of deep planting Salix cheilophila and Tamarix with their long stem, which can effectively resist drought. We found that it had lower cost and higher live rate, and has a better sand prevention effect than deep planting of Poplar. Finally we choose the optimize management model as follows: Artemisia direct seeding > Caragana direct seeding, Tamarix cutting and seedling > Salix cheilophila deep planting, Sea-buckthorn seedling > Tamarix deep planting > Tamarix seedling > Poplar deep planting > Salix cheilophila seedling > Poplar seedling. It has resolved the key problem of control sand flow speed and low efficiency, sand burying and wind erosion and low conservation rate for forestation in the sandy area.

Priming in a free association task as a function of association directionality.

PubMed

Zeelenberg, R; Shiffrin, R M; Raaijmakers, J G

1999-11-01

Two experiments investigated priming in free association, a conceptual implicit memory task. The stimuli consisted of bidirectionally associated word pairs (e.g., BEACH-SAND) and unidirectionally associated word pairs that have no association from the target response back to the stimulus cue (e.g., BONE-DOG). In the study phase, target words (e.g., SAND, DOG) were presented in an incidental learning task. In the test phase, participants generated an associate to the stimulus cues (e.g., BEACH, BONE). In both experiments, priming was obtained for targets (e.g., SAND) that had an association back to the cue, but not for targets (e.g., DOG) for which such a backward association was absent. These results are problematic for theoretical accounts that attribute priming in free association to the strengthening of target responses. It is argued that priming in free association depends on the strengthening of cue-target associations.

Transport of viruses through saturated and unsaturated columns packed with sand

USGS Publications Warehouse

Anders, R.; Chrysikopoulos, C.V.

2009-01-01

Laboratory-scale virus transport experiments were conducted in columns packed with sand under saturated and unsaturated conditions. The viruses employed were the male-specific RNA coliphage, MS2, and the Salmonella typhimurium phage, PRD1. The mathematical model developed by Sim and Chrysikopoulos (Water Resour Res 36:173-179, 2000) that accounts for processes responsible for removal of viruses during vertical transport in one-dimensional, unsaturated porous media was used to fit the data collected from the laboratory experiments. The liquid to liquid-solid and liquid to air-liquid interface mass transfer rate coefficients were shown to increase for both bacteriophage as saturation levels were reduced. The experimental results indicate that even for unfavorable attachment conditions within a sand column (e.g., phosphate-buffered saline solution; pH = 7.5; ionic strength = 2 mM), saturation levels can affect virus transport through porous media. ?? Springer Science+Business Media B.V. 2008.

[Effect of shifting sand burial on evaporation reduction and salt restraint under saline water irrigation in extremely arid region].

PubMed

Zhang, Jian-Guo; Zhao, Ying; Xu, Xin-Wen; Lei, Jia-Qiang; Li, Sheng-Yu; Wang, Yong-Dong

2014-05-01

The Taklimakan Desert Highway Shelterbelt is drip-irrigated with high saline groundwater (2.58-29.70 g x L(-1)), and shifting sand burial and water-salt stress are most common and serious problems in this region. So it is of great importance to study the effect of shifting sand burial on soil moisture evaporation, salt accumulation and their distribution for water saving, salinity restraint, and suitable utilization of local land and water resources. In this study, Micro-Lysimeters (MLS) were used to investigate dynamics of soil moisture and salt under different thicknesses of sand burial (1, 2, 3, 4, and 5 cm), and field control experiments of drip-irrigation were also carried out to investigate soil moisture and salt distribution under different thicknesses of shifting sand burial (5, 10, 15, 20, 25, 30, 35, and 40 cm). The soil daily and cumulative evaporation decreased with the increase of sand burial thickness in MLS, cumulative evaporation decreased by 2.5%-13.7% compared with control. And evaporative inhibiting efficiency increased with sand burial thickness, evaporative inhibiting efficiency of 1-5 cm sand burial was 16.7%-79.0%. Final soil moisture content beneath the interface of sand burial increased with sand burial thickness, and it increased by 2.5%-13.7% than control. The topsoil EC of shifting sand in MLS decreased by 1.19-6.00 mS x cm(-1) with the increasing sand burial thickness, whereas soil salt content beneath the interface in MLS increased and amplitude of the topsoil salt content was higher than that of the subsoil. Under drip-irrigation with saline groundwater, average soil moisture beneath the interface of shifting sand burial increased by 0.4% -2.0% compare with control, and the highest value of EC was 7.77 mS x cm(-1) when the sand burial thickness was 10 cm. The trend of salt accumulation content at shifting sand surface increased firstly, and then decreased with the increasing sand burial thickness. Soil salt contents beneath the interface of shifting sand burial were much lower than that of shifting sand surface. 35 cm was the critical sand burial thickness for water-saving and salt restraint. In summary, sand burial had obvious inhibition effects on soil evaporation and salt accumulation, so maybe it could be used to save water and reduce salt accumulation in arid shifting desert areas.

WISDOM GPR performance assessment in a cold artificial environment

NASA Astrophysics Data System (ADS)

Dechambre, M.; Ciarletti, V.; Biancheri-Astier, M.; Saintenoy, A.; Costard, F.; Hassen-Khodja, R.

2012-04-01

The WISDOM (Water Ice Subsurface Deposit Observation on Mars) GPR is one of the instruments that have been selected as part of the Pasteur payload of ESA's 2018 ExoMars Rover mission. WISDOM has been designed to obtain information about the nature of the subsurface along the rover path with the objective to explore the first ~ 3 m of the soil with a vertical resolution of a few centimetres. The sub-surface properties that can be addressed with WISDOM are variations in composition, texture, stratification (e.g., number, thickness and orientation of layers), the presence of unconformities and other structural characteristics (such as fractures and the deformation of strata). It is then essential to quantify the performances of WISDOM in controlled conditions, and several full polarimetric measurements have been carried out with the prototype in a cold artificial environment. The main objectives are the detection of different interface between homogeneous materials with WISDOM. The characterization of the material (porosity, % of water, dielectric properties, thickness and depth, temperature ...) is well-controlled. The cold room facility of IDES at Orsay (France) has been used, the ambient temperature ranged from -7° C to -10° C. A tank laying on the metallic floor (height: 0.5m, width: 0.80 m, length: 1.20m) in macrolon can contain liquid or frozen water or layers (dielectric contrasts) of home-maid permafrost (frozen saturated sand) with and without embedded objects or fractures. The temperature inside the medium (ice or permafrost) is controlled, the radar antennas are put on a sheet of polystyrene over the tank. Frequent measurements were performed (every 2cm) along a track from one side to the other side of the tank. The experimental conditions were: (1)dry cold sand (Fontainebleau sand) : porosity 35% density 2,67 (2) saturated wet sand : 35% of water (3) permafrost (frozen saturated sand) : 35% of ice content 1 layer: 3 consecutive experiments : 10cm dry sand ( 1) 10cm saturated sand (2) 10cm permafrost(3) 2 layers :previous 10cm permafrost in the bottom +3 consecutive experiments : 10cm dry sand ( 1) 10cm saturated sand (2) 10cm permafrost(3) . Basalt rocks and air fractures are or are not embedded in the layers Values of the permittivity of dry sand and permafrost were retrieve by two different ways. 1.Retrieval of the sand and permafrost permittivity from delay measurements knowing the layer thickness d ɛr = ct/2d = n2 2. Retrieval of the sand and permafrost permittivity from amplitude measurements knowing a calibration reference (reflection over a metallic plate), R is the Fresnel coefficient between the air and the medium. Aint/ = R = n- 1-,ɛ = 1+-R-= n2 Aair n +1 r 1- R Results : Internal layering is observed. The transition between dry sand and permafrost can be detected. The permittivity can be retrieved from delay or amplitude measurements as well from delay measurements : dry sand ɛr = 2.71 permafrost ɛr = 3.72 from amplitude measurements : dry sand ɛr = 2.73 permafrost ɛr = 3.35 Embedded objects are detected, Fracture and its orientation is detected.

Performance simulation of BaBar DIRC bar boxes in TORCH

NASA Astrophysics Data System (ADS)

Föhl, K.; Brook, N.; Castillo García, L.; Cussans, D.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Harnew, N.; Piedigrossi, D.; Rademacker, J.; Ros García, A.; van Dijk, M.

2017-12-01

TORCH is a large-area precision time-of-flight detector based on the DIRC principle. The DIRC bar boxes of the BaBar experiment at SLAC could possibly be reused to form a part of the TORCH detector time-of-flight wall area, proposed to provide positive particle identification of low momentum kaons in the LHCb experiment at CERN. For a potential integration of BaBar bar boxes into TORCH, new imaging readout optics are required. From the several designs of readout optics that have been considered, two are used in this paper to study the effect of BaBar bar optical imperfections on the detector reconstruction performance. The kaon-pion separation powers obtained from analysing simulated photon hit patterns show the performance reduction for a BaBar bar of non-square geometry compared to a perfectly rectangular cross section.

Transport of carboxyl-functionalized carbon black nanoparticles in saturated porous media: Column experiments and model analyses

NASA Astrophysics Data System (ADS)

Kang, Jin-Kyu; Yi, In-Geol; Park, Jeong-Ann; Kim, Song-Bae; Kim, Hyunjung; Han, Yosep; Kim, Pil-Je; Eom, Ig-Chun; Jo, Eunhye

2015-06-01

The aim of this study was to investigate the transport behavior of carboxyl-functionalized carbon black nanoparticles (CBNPs) in porous media including quartz sand, iron oxide-coated sand (IOCS), and aluminum oxide-coated sand (AOCS). Two sets of column experiments were performed under saturated flow conditions for potassium chloride (KCl), a conservative tracer, and CBNPs. Breakthrough curves were analyzed to obtain mass recovery and one-dimensional transport model parameters. The first set of experiments was conducted to examine the effects of metal (Fe, Al) oxides and flow rate (0.25 and 0.5 mL min- 1) on the transport of CBNPs suspended in deionized water. The results showed that the mass recovery of CBNPs in quartz sand (flow rate = 0.5 mL min- 1) was 83.1%, whereas no breakthrough of CBNPs (mass recovery = 0%) was observed in IOCS and AOCS at the same flow rate, indicating that metal (Fe, Al) oxides can play a significant role in the attachment of CBNPs to porous media. In addition, the mass recovery of CBNPs in quartz sand decreased to 76.1% as the flow rate decreased to 0.25 mL min- 1. Interaction energy profiles for CBNP-porous media were calculated using DLVO theory for sphere-plate geometry, demonstrating that the interaction energy for CBNP-quartz sand was repulsive, whereas the interaction energies for CBNP-IOCS and CBNP-AOCS were attractive with no energy barriers. The second set of experiments was conducted in quartz sand to observe the effect of ionic strength (NaCl = 0.1 and 1.0 mM; CaCl2 = 0.01 and 0.1 mM) and pH (pH = 4.5 and 5.4) on the transport of CBNPs suspended in electrolyte. The results showed that the mass recoveries of CBNPs in NaCl = 0.1 and 1.0 mM were 65.3 and 6.4%, respectively. The mass recoveries of CBNPs in CaCl2 = 0.01 and 0.1 mM were 81.6 and 6.3%, respectively. These results demonstrated that CBNP attachment to quartz sand can be enhanced by increasing the electrolyte concentration. Interaction energy profiles demonstrated that the interaction energy profile for CBNP-quartz sand was compressed and that the energy barrier decreased as the electrolyte concentration increased. Furthermore, the mass recovery of CBNPs in the presence of divalent ions (CaCl2 = 0.1 mM) was far lower than that in the presence of monovalent ions (NaCl = 0.1 mM), demonstrating a much stronger effect of Ca2 + than Na+ on CBNP transport. Mass recovery of CBNPs at pH 4.5 was 55.6%, which was lower than that (83.1%) at pH 5.4, indicating that CBNP attachment to quartz sand can be enhanced by decreasing the pH. The sticking efficiencies (α) calculated from the mass recovery by colloid filtration theory were in the range from 2.1 × 10- 2 to 4.5 × 10- 1, which were far greater than the values (2.56 × 10- 6-3.33 × 10- 2) of theoretical sticking efficiencies (αtheory) calculated from the DLVO energy by the Maxwell model.

A Push-pull Protocol to Reduce Colonization of Bird Nest Boxes by Honey Bees.

PubMed

Efstathion, Caroline A; Kern, William H

2016-09-04

Introduction of the invasive Africanized honey bee (AHB) into the Neotropics is a serious problem for many cavity nesting birds, specifically parrots. These bees select cavities that are suitable nest sites for birds, resulting in competition. The difficulty of removing bees and their defensive behavior makes a prevention protocol necessary. Here, we describe a push-pull integrated pest management protocol to deter bees from inhabiting bird boxes by applying a bird safe insecticide, permethrin, to repel bees from nest boxes, while simultaneously attracting them to pheromone-baited swarm traps. Shown here is an example experiment using Barn Owl nest boxes. This protocol successfully reduced colonization of Barn Owl nest boxes by Africanized honey bees. This protocol is flexible, allowing adjustments to accommodate a wide range of bird species and habitats. This protocol could benefit conservation efforts where AHB are located.

Effect of structured visual environments on apparent eye level.

PubMed

Stoper, A E; Cohen, M M

1989-11-01

Each of 12 subjects set a binocularly viewed target to apparent eye level; the target was projected on the rear wall of an open box, the floor of which was horizontal or pitched up and down at angles of 7.5 degrees and 15 degrees. Settings of the target were systematically biased by 60% of the pitch angle when the interior of the box was illuminated, but by only 5% when the interior of the box was darkened. Within-subjects variability of the settings was less under illuminated viewing conditions than in the dark, but was independent of box pitch angle. In a second experiment, 11 subjects were tested with an illuminated pitched box, yielding biases of 53% and 49% for binocular and monocular viewing conditions, respectively. The results are discussed in terms of individual and interactive effects of optical, gravitational, and extraretinal eye-position information in determining judgements of eye level.

Small Particle Impact Damage on Different Glass Substrates

NASA Technical Reports Server (NTRS)

Waxman, R.; Guven, I.; Gray, P.

2017-01-01

Impact experiments using sand particles were performed on four distinct glass substrates. The sand particles were characterized using the X-Ray micro-CT technique; 3-D reconstruction of the particles was followed by further size and shape analyses. High-speed video footage from impact tests was used to calculate the incoming and rebound velocities of the individual sand impact events, as well as particle volume. Further, video analysis was used in conjunction with optical and scanning electron microscopy to relate the incoming velocity and shape of the particles to subsequent fractures, including both radial and lateral cracks. Analysis was performed using peridynamic simulations.

[Effect of humic acids on migration and transformation of NH4(+) -N in saturated aquifer].

PubMed

Meng, Qing-Jun; Zhang, Yan; Feng, Qi-Yan; Zhang, Shuang-Sheng

2011-11-01

Isothermal adsorption experiment was used to study the adsorbing process of NH4(+) -N in quartz sands under the conditions with and without humic acid; the Langmuir and Freundlich equations were used to fit the absorption result and the maximum adsorption capacity of NH4(+) -N by quarts sands was calculated. Through the soil column experiments, the concentration of NH4(+) -N, NO3(-) -N and NO2(-) -N in effluent water in the tested soil column was investigated, and the effect of humic acid on migration and transformation of NH4(+) -N in saturated aquifer was analyzed, and Pseudo-second-order Kinetics Equation and Two-step Adsorption Kinetics Rate Equation were applied to fit the kinetic processes. The results showed that both Langmuir and Freundlich models can well describe the isothermal adsorption process of NH4(+) -N on the surface of quartz sands, which means that NH4(+) -N adsorbed by the quartz sand was mainly in the form of monolayer adsorption. The humic acid could increase the adsorption capacity of NH4(+) -N on quartz sand, and the saturated adsorption capacity was 0.354 mg x g(-1) under the condition with humic acid and 0.205 mg x g(-1) with the absence of humic acid. The experiment indicated that humic acid increased the adsorption capacity of NH4(+) -N on the surface of quartz sand by increasing adsorption space in the initial stage. After saturation, humic acid influenced the migration and transformation of NH4(+) -N to NO3(-) -N and NO2(-) -N probably through providing carbon source and energy for microorganisms such as nitrifying bacteria and then resulting in lower NH4(+) -N concentration in effluent water. Both Pseudo-second-order Kinetics Equation and Two-step Adsorption Kinetics Rate Equations can well describe the process of NH4(+) -N adsorption kinetics on quartz sand (R2 = 0.997 7 and R2 = 0.998 1 with humic acid; R2 = 0.992 3 and R2 = 0.994 4 without humic acid), indicating that this process was chemical adsorption. By comparing the adsorption rate coefficient of Two-step Adsorption Kinetics Rate Equation k3 (0.247 and 0.143, respectively) and k4 (0.006 27 and 0.001 7) between the treatments with and without humic acid, it can be referred that NH4(+) -N was non-orientated adsorption on active points of the quartz sand at the initial stage, and the humic acid could increase the equilibrium adsorption quantity(q(e)) of NH4(+) -N on quartz sands.

A theory of vibrational prey localization in two dimensions: the sand scorpion

NASA Astrophysics Data System (ADS)

van Hemmen, J. Leo

2000-03-01

Sand scorpions, and many other arachnids, find their prey at night by localizing the source of mechanical waves produced by prey movements. Substrate vibrations propagating through sand evoke stimulus-locked action potentials from slit sensilla on the scorpion's eight `feet' (tarsi). We present a neuronal model to account for stimulus angle determination in a two-dimensional plane using a population of second-order neurons, each receiving excitatory input from one tarsus and inhibition from a triad opposite to it. This input opens a time window whose width determines the firing probability of each of the second-order neurons. The population then `votes' for the direction. Stochastic resonance is realized through tuning the balance between excitation and inhibition. The agreement with behavioral experiments on sand scorpions is excellent.

The importance of sand in the formation of avulsion channels within experimental fans that develop from sediment mixtures of mud and sand

NASA Astrophysics Data System (ADS)

Iscen, N.; Strom, K.

2017-12-01

Autogenic channel migration and avulsion has long been recognized as important drivers of alluvial fan dynamics. In the literature, several field studies have documented that the presence and the amount of sand transport through a channel is important for channel incision in alluvial fans and deltas. In our experiments, we present the general autogenic avulsion cycle of experimental alluvial fans with mixtures of cohesive sediment and sand with a range of boundary conditions, and we detail the importance of mobile sand fraction in the development of channels that lead to avulsion. Experimental observations demonstrate that new channels form at topographically low regions within the floodplain providing that sand is transported to these topographic lows due to overbank flow or levee breaching. In addition to the sediment transported from upstream, erosion of a previous deposit and an ongoing backfilling nearby are observed as the possible sources of sand getting into the ghost channels. We explore whether the presence of sand is important for channel development because it increases abrasion of the channel or because it changes the roughness characteristics of the flow. We also examine the affect of sediment and water supply change on the newly described channelization process and link distinctive channel morphologies to different stages of described channel development and the avulsion process.

Object permanence in orangutans (Pongo pygmaeus) and squirrel monkeys (Saimiri sciureus).

PubMed

de Blois, S T; Novak, M A; Bond, M

1998-06-01

The authors tested orangutans (Pongo pygmaeus) and squirrel monkeys (Saimiri sciureus) on object permanence tasks. In Experiment 1, orangutans solved all visible displacements and most invisible displacements except those involving movements into 2 boxes successively. In Experiment 2, performance of orangutans on double invisible displacements and control displacements (assessing simple strategies) was compared. Orangutans did not use the simple strategy of selecting the box visited last by the experimenter. Instead, poorer performance on double invisible displacements may have been related to increased memory requirements. In Experiment 3, squirrel monkeys were tested using the procedure of Experiment 1. Squirrel monkeys solved visible but did not comprehend invisible displacements. Results suggest that orangutans but not squirrel monkeys possess Stage 6 object permanence capabilities.

Facilitated transport of Cu with hydroxyapatite nanoparticles in saturated sand: Effects of solution ionic strength and composition

USDA-ARS?s Scientific Manuscript database

Column experiments were conducted to investigate the facilitated transport of Cu in association with hydroxyapatite nanoparticles (nHAP) in water-saturated quartz sand at different solution concentrations of NaCl (0 to 100 mM) or CaCl2 (0.1 to 1.0 mM). The experimental breakthrough curves and retent...

Glass Microbeads in Analog Models of Thrust Wedges.

PubMed

D'Angelo, Taynara; Gomes, Caroline J S

2017-01-01

Glass microbeads are frequently used in analog physical modeling to simulate weak detachment zones but have been neglected in models of thrust wedges. Microbeads differ from quartz sand in grain shape and in low angle of internal friction. In this study, we compared the structural characteristics of microbeads and sand wedges. To obtain a better picture of their mechanical behavior, we determined the physical and frictional properties of microbeads using polarizing and scanning electron microscopy and ring-shear tests, respectively. We built shortening experiments with different basal frictions and measured the thickness, slope and length of the wedges and also the fault spacings. All the microbeads experiments revealed wedge geometries that were consistent with previous studies that have been performed with sand. However, the deformation features in the microbeads shortened over low to intermediate basal frictions were slightly different. Microbeads produced different fault geometries than sand as well as a different grain flow. In addition, they produced slip on minor faults, which was associated with distributed deformation and gave the microbeads wedges the appearance of disharmonic folds. We concluded that the glass microbeads may be used to simulate relatively competent rocks, like carbonates, which may be characterized by small-scale deformation features.

How Efficient is Vegetation in Reducing Wind Erosion and Emission of Health-Threatening Fine Dust PM10? - A Wind Tunnel Approach

NASA Astrophysics Data System (ADS)

Burri, K.; Graf, F.

2009-04-01

World wide, wind erosion and desertification are most alarming processes of environmental degradation. Not only do they cause tremendous losses of fertile soil, but they also seriously affect human health. Pulmonary tuberculosis (silicosis) is one of the major diseases that have been linked to mineral fine dust (PM10) in the atmosphere. It is widely accepted that the re-establishment of an intact vegetation cover is the most effective measure against wind erosion. However, despite numerous investigations, the mechanisms responsible for the protective effect of vegetation are still not completely understood. Since the phenomenon involves highly variable interactions between soil, plants and atmosphere, it is particularly difficult to quantify the efficiency of vegetation in reducing wind erosion. As an alternative to field investigations, wind tunnel experiments offer the advantage to control specific parameters within this highly complex system. In this study, a series of wind tunnel experiments was performed including measurements of sediment transport and PM10 emission in differently dense grass canopies of Lolium perenne (91, 24, 5 and 0 plants per square meter). The novelty of the present wind tunnel study is the use of living plants instead of artificial imitations or dead plant parts. Although more and more sophisticated imitations of vegetation have been used in recent studies, the behaviour of living plants is likely to differ significantly. Coloured quartz sand was used for visualizing sand erosion and deposition patterns. The vertical profiles of aeolian sediment flux were analysed with a stackable sediment sampler composed of 60 collecting boxes, each with a height of 1 cm. The results of this study confirm that both sediment transport and PM10 emission strongly decrease with increasing plant cover. The protective effect of the plants was found to be linked to characteristic changes in the vertical profile of aeolian sediment flux and to specific spatial patterns of sediment deposition. Furthermore, observations indicate that the performance of plants in wind erosion control strongly depends on plant species specific characteristics, particularly growth form and stiffness, as well as on their physiological state. The use of living plants in wind tunnel experiments offers the possibility to study a wide range of more specific aspects of biological wind erosion control. As a next step it is planned to test the effect of mycorrhizal fungi on the wind erodibility of vegetated soil systems.

Sand Volcano Following Earthquake

NASA Technical Reports Server (NTRS)

1989-01-01

Sand boil or sand volcano measuring 2 m (6.6 ft.) in length erupted in median of Interstate Highway 80 west of the Bay Bridge toll plaza when ground shaking transformed loose water-saturated deposit of subsurface sand into a sand-water slurry (liquefaction) in the October 17, 1989, Loma Prieta earthquake. Vented sand contains marine-shell fragments. Sand and soil grains have faces that can cause friction as they roll and slide against each other, or even cause sticking and form small voids between grains. This complex behavior can cause soil to behave like a liquid under certain conditions such as earthquakes or when powders are handled in industrial processes. Mechanics of Granular Materials (MGM) experiments aboard the Space Shuttle use the microgravity of space to simulate this behavior under conditions that carnot be achieved in laboratory tests on Earth. MGM is shedding light on the behavior of fine-grain materials under low effective stresses. Applications include earthquake engineering, granular flow technologies (such as powder feed systems for pharmaceuticals and fertilizers), and terrestrial and planetary geology. Nine MGM specimens have flown on two Space Shuttle flights. Another three are scheduled to fly on STS-107. The principal investigator is Stein Sture of the University of Colorado at Boulder. (Credit: J.C. Tinsley, U.S. Geological Survey)

An evaluation of the natural radioactivity in Andaman beach sand samples of Thailand after the 2004 tsunami.

PubMed

Malain, D; Regan, P H; Bradley, D A; Matthews, M; Al-Sulaiti, H A; Santawamaitre, T

2012-08-01

Following the 2004 'Boxing day' tsunami, a determination has been made of the activity concentrations of (226)Ra, (232)Th and (40)K in beach sand samples which have been collected from various locations along the Andaman coast of the Thai peninsula. Use has been made of a HPGe detector-based, low-background gamma-ray counting system. The natural radioactivity levels of (226)Ra, (232)Th and (40)K measured from these samples was found to lie in the range 1.6-52.5, 0.3-73.9 and 2.8-1111.9Bq/kg respectively for the west coast and 3.5-83.1, 4.5-42.0, and 9.6-1376 Bq/kg respectively for the east coast. The radioactivity concentrations of (226)Ra, (232)Th and (40)K along the Andaman coast are comparable to that of the east coast, which was not exposed to the tsunami. The corresponding annual effective dose varies from 1.6-105.9 μSv/y with a mean value of 59.1 ± 0.3 μSv/y, significantly lower than the worldwide average as reported by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) (2000). Copyright © 2012 Elsevier Ltd. All rights reserved.

Why do seif dunes meander?

NASA Astrophysics Data System (ADS)

Kryger, Mateusz; Bubenzer, Olaf; Parteli, Eric

2017-04-01

Seif dunes - which develop in the absence of vegetation and elongate in the resultant sand transport direction - are the prevailing dune type in many deserts of Earth and Mars and display a meandering shape that has challenged geomorphologists for decades. Understanding the factors controlling seif dune morphology may have impact for a broad range of scientific areas, in particular in the investigation of planetary wind regimes, as dune shape is primarily affected by wind directionality. Sand roses of areas hosting seif dunes display, in general, two main wind directions that form a divergence angle larger than 90˚ . Indeed, theory of dune formation predicts that longitudinal alignment of aeolian bedforms occurs under obtuse bimodal winds, a prediction that has been confirmed by field observations and numerical simulations of aeolian dunes, as well as by experiments on subaqueous bedforms. However, numerical simulations and water tank experiments performed under conditions of bimodal flows could never reproduce one of the most salient characteristics of the seif dune shape, which is its meandering. Instead, longitudinal dunes produced in such simulations and experiments display an unrealistic straight shape, which elongates into the resultant transport trend without developing the sinuous morphology of the seif dunes. Here we show, by means of morphodynamic modeling of aeolian sediment transport and dune formation under directionally varying flows, that the meandering shape of seif dunes can be explained by the action of subordinated sand-moving winds, which occur in addition to both main wind components of the bimodal wind. Because such subordinated winds - inherent to most measured sand roses of seif dune fields - are associated with transport rates much smaller than the sand flux values of the main bimodal wind components - they have been long thought to be negligible for dune shape. However, our simulations show that meandering may be caused by a single secondary wind component in the sand rose with transport rate of about 1/5 of the flux due to the bimodal wind components. To verify our model we calculate dune formation using the sand rose of the seif dune field in Bir Lahfan, Sinai, and find good quantitative agreement between the shape of seif dunes in this field and the dune morphology obtained in the simulations. Our simulations suggest that meandering seif dunes constitute a dune type produced by multimodal wind systems and cannot form under (strictly) bimodal wind regimes.

Fate of parabens and 4-hydroxybenzoic acid in aquifer materials columns during step experiments with fresh and sea waters

NASA Astrophysics Data System (ADS)

López-Ortiz, C. M.; Boluda-Botella, N.; Prats-Rico, D.; Sentana-Gadea, I.

2018-02-01

Coastal areas submitted to seawater intrusion and with discharges from urban and industrial wastewaters, municipal landfill leachates, rivers, recreational waters and other sources are sensitive to be polluted with parabens. Understanding the fate of these compounds in environmental studies, it requires previously the knowledge of the reactive processes in controlled conditions. In this research, laboratory columns experiments were carried out with a group of parabens (methyl-, ethyl-, propyl- and butylparaben) and their main degradation compound (4-hydroxybenzoic acid) to study mainly the dynamic sorption processes in different aquifer materials (100% sand and heterogeneous: 81% sand, 9% silt and 10% clay) and with fresh and sea waters, the end members of seawater intrusions. To the column hydrodynamic characterization, tracer assays with increase and decrease of salinity were performed, to obtain the mean residence time of each column and other transport parameters which allow us to compare parabens' sorption in different conditions. The results of the adsorption and desorption of parabens in the sand column demonstrated be fast and simultaneous, with a short delay and without influence of the water salinity. Very different results were found in the column experiments with heterogeneous material, where the presence of clay and organic matter increase the time of adsorption/desorption as the length of the alkyl chain paraben increased, according with their hydrophobicity. It should be noted that despite the quick desorption of the major quantities of parabens, the elution of their trace concentrations was very slow (for the seawater, the buthylparaben required a dimensionless time of 800). Planning the restoration of a coastal aquifer with freshwater, and in the conditions of the studied sand column experiment, it will need a dimensionless time of 160. However, it is necessary to take into account that the studied parabens and 4-hydroxybenzoic acid are biodegradable substances, as can be seen in long term experiments, when bacterial proliferation could occur, despite starting the experiment under sterile conditions.

Clogging of an Alpine streambed by silt-sized particles - Insights from laboratory and field experiments.

PubMed

Fetzer, Jasmin; Holzner, Markus; Plötze, Michael; Furrer, Gerhard

2017-12-01

Clogging of streambeds by suspended particles (SP) can cause environmental problems, as it can negatively influence, e.g., habitats for macrozoobenthos, fish reproduction and groundwater recharge. This especially applies in the case of silt-sized SP. Until now, most research has dealt with coarse SP and was carried out in laboratory systems. The aims of this study are to examine (1) whether physical clogging by silt-sized SP exhibits the same dynamics and patterns as by sand-sized SP, and (2) the comparability of results between laboratory and field experiments. We carried out vertical column experiments with sand-sized bed material and silt-sized SP, which are rich in mica minerals. In laboratory experiments, we investigated the degree of clogging quantified by the reduction of porosity and hydraulic conductivity and the maximum clogging depth as a function of size and shape of bed material, size of SP, pore water flow velocity, and concentration of calcium cations. The SP were collected from an Alpine sedimentation basin, where our field experiments were carried out. To investigate the clogging process in the field, we buried columns filled with sand-sized quartz in the stream bed. We found that the maximal bed-to-grain ratio where clogging still occurs is larger for silt-sized SP than for sand-sized SP. The observed clogging depths and the reduction of flow rate through the column from our laboratory experiments were comparable to those from the field. However, our field results showed that the extent of clogging strongly depends on the naturally-occurring hydrological dynamics. The field location was characterized by a more polydisperse suspension, a strongly fluctuating water regime, and high SP concentrations at times, leading to more heterogeneous and more pronounced clogging when compared to laboratory results. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Rod pumping and proppant flowback at the Lost Hills Field

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

Roberts, I.G.

1995-12-31

Proppant flowback from hydraulically fractured wells can lead to sand wear on the pump barrel and plunger and increased pulling costs on rod pumped wells. Two approaches for lengthening run times of the pumps were tried. One approach was to install pumps that will allow production of a sand laden fluid. Pressure actuated plunger (PAP) pumps were field tested and showed an average increase of 81.6% in run time. These split ring wiper pumps clean the barrel of sand prior to the passing of the plunger. The other approach was to keep the sand and from entering the pumps. Whenmore » down hole filters were utilized, run life of the pumps with the filters increases 135%. Well pulling cost savings of $11.91 per well-day and $9.24 per well-day are documented for the PAP pumps and filters, respectively. Application guidelines based on the sand loading rate and gross liquid production of the wells are presented, as well as some operational experiences.« less

Young Infants' Reasoning about Physical Events Involving Inert and Self-Propelled Objects

ERIC Educational Resources Information Center

Luo, Yuyan; Kaufman, Lisa; Baillargeon, Renee

2009-01-01

The present research examined whether 5- to 6.5-month-old infants would hold different expectations about various physical events involving a box after receiving evidence that it was either inert or self-propelled. Infants were surprised if the inert but not the self-propelled box: reversed direction spontaneously (Experiment 1); remained…

Optimization of extraction of chitin from procambarus clarkia shell by Box-Behnken design

NASA Astrophysics Data System (ADS)

Dong, Fang; Qiu, Hailong; Jia, Shaoqian; Dai, Cuiping; Kong, Qingxin; Xu, Changliang

2018-06-01

This paper investigated the optimizing extraction processing of chitin from procambarus clarkia shell by Box-Behnken design. Firstly, four independent variables were explored in single factor experiments, namely, concentration of hydrochloric acid, soaking time, concentration of sodium hydroxide and reaction time. Then, based on the results of the above experiments, four factors and three levels experiments were planned by Box-Behnken design. According to the experimental results, we harvested a second-order polynomial equation using multiple regression analysis. In addition, the optimum extraction process of chitin of the model was obtained: concentration of HCl solution 1.54mol/L, soaking time 19.87h, concentration of NaOH solution 2.9mol/L and reaction time 3.54h. For proving the accuracy of the model, we finished the verification experiment under the following conditions: concentration of hydrochloric acid 1.5mol/L, soaking time 20h, concentration of sodium hydroxide 3mol/L and reaction time 3.5h. The actual yield of chitin reached 18.76%, which was very close to the predicted yield (18.66%) of the model. The result indicated that the optimum extraction processing of chitin was feasible and practical.

Aeolian sand transport over complex intertidal bar-trough beach topography

NASA Astrophysics Data System (ADS)

Anthony, Edward J.; Ruz, Marie-Hélène; Vanhée, Stéphane

2009-04-01

Aeolian sand transport on macrotidal beaches with complex intertidal bar-trough topography (ridge-and-runnel beaches) was assessed from experiments in northern France that involved measurements of wind speed, saltation, surface moisture contents, and rates of sand trapping across surveyed portions of the upper beach profile. Beaches exhibiting intertidal bars and troughs are much more complex, topographically, than simple reflective or dissipative beaches. Furthermore, the intertidal bar-trough morphology commonly exhibits strong cross-shore variations in the moisture contents of the beach surface and in patterns of bedform development. The results of four 30-minute experiments, conducted along topographically surveyed portions of the upper beach-dune toe profile, show that troughs act as extremely efficient sand interceptors, because of their permanently saturated state, which also inhibits sand mobilisation. Troughs, thus, limit or segment the dry fetch during conditions of intermittent saltation. Flow lines, inferred from the wind profiles, suggest that complex interactions at the boundary layer are generated by the bar-trough topography. Troughs systematically appear to be characterised by air expansion, while bar faces generate ramp wind acceleration for onshore winds, and sometimes immediate downwind deceleration for offshore winds. These effects may also contribute to cross-shore variations in the rates of sand trapping. Finally, a simple conceptual model of effective fetch development, integrating the effects of the spring-neap tidal range and of gross bar-trough morphological variability over time, is proposed for bar-trough beaches. The model highlights the key theme of fetch segmentation induced by cross-shore differentiation in the moisture contents of the beach surface hinged on the complex topography of multiple bars and troughs.

Occurrence and Persistence of Bacterial Pathogens and Indicator Organisms in Beach Sand along the California Coast

PubMed Central

Yamahara, Kevan M.; Sassoubre, Lauren M.; Goodwin, Kelly D.

2012-01-01

This report documents the presence of fecal indicators and bacterial pathogens in sand at 53 California marine beaches using both culture-dependent and -independent (PCR and quantitative PCR [QPCR]) methods. Fecal indicator bacteria were widespread in California beach sand, with Escherichia coli and enterococci detected at 68% and 94% of the beaches surveyed, respectively. Somatic coliphages and a Bacteroidales human-specific fecal marker were detected at 43% and 13% of the beaches, respectively. Dry sand samples from almost 30% of the beaches contained at least one of the following pathogens: Salmonella spp., Campylobacter spp., Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA), which were detected at 15%, 13%, 14%, and 3% of tested beaches, respectively. Fecal indicators and pathogens were poorly correlated to one another and to land cover. Sands were dry at the time of collection, and those with relatively high moisture tended to have higher concentrations or a more frequent occurrence of both indicators and pathogens. Using culture-dependent assays, fecal indicators decayed faster than pathogens in microcosm experiments using unaltered beach sand seeded with sewage and assessed by culture-dependent assays. The following order of persistence was observed (listed from most to least persistent): Campylobacter > Salmonella > somatic coliphages > enterococci > E. coli > F+ phages. In contrast, pathogens decayed faster than fecal indicators in culture-independent assays: enterococci > Bacteroidales human-specific marker > Salmonella > Campylobacter. Microcosm experiments demonstrated that both indicators and pathogens were mobilized by wetting with seawater. Decay rates measured by QPCR were lower than those measured with culture-dependent methods. Enterococcal persistence and possible growth were observed for wetted microcosms relative to unwetted controls. PMID:22247142

Packaging waste prevention in the distribution of fruit and vegetables: An assessment based on the life cycle perspective.

PubMed

Tua, Camilla; Nessi, Simone; Rigamonti, Lucia; Dolci, Giovanni; Grosso, Mario

2017-04-01

In recent years, alternative food supply chains based on short distance production and delivery have been promoted as being more environmentally friendly than those applied by the traditional retailing system. An example is the supply of seasonal and possibly locally grown fruit and vegetables directly to customers inside a returnable crate (the so-called 'box scheme'). In addition to other claimed environmental and economic advantages, the box scheme is often listed among the packaging waste prevention measures. To check whether such a claim is soundly based, a life cycle assessment was carried out to verify the real environmental effectiveness of the box scheme in comparison to the Italian traditional distribution. The study focused on two reference products, carrots and apples, which are available in the crate all year round. An experience of a box scheme carried out in Italy was compared with some traditional scenarios where the product is distributed loose or packaged at the large-scale retail trade. The packaging waste generation, 13 impact indicators on environment and human health and energy consumptions were calculated. Results show that the analysed experience of the box scheme, as currently managed, cannot be considered a packaging waste prevention measure when compared with the traditional distribution of fruit and vegetables. The weaknesses of the alternative system were identified and some recommendations were given to improve its environmental performance.

Self assembly, mobilization, and flotation of crude oil contaminated sand particles as granular shells on gas bubbles in water.

PubMed

Tansel, Berrin; Boglaienko, Daria

2017-01-01

Contaminant fate and transport studies and models include transport mechanisms for colloidal particles and dissolved ions which can be easily moved with water currents. However, mobilization of much larger contaminated granular particles (i.e., sand) in sediments have not been considered as a possible mechanism due to the relatively larger size of sand particles and their high bulk density. We conducted experiments to demonstrate that oil contaminated granular particles (which exhibit hydrophobic characteristics) can attach on gas bubbles to form granular shells and transfer from the sediment phase to the water column. The interactions and conditions necessary for the oil contaminated granular particles to self assemble as tightly packed granular shells on the gas bubbles which transfer from sediment phase to the water column were evaluated both experimentally and theoretically for South Louisiana crude oil and quartz sand particles. Analyses showed that buoyancy forces can be adequate to move the granular shell forming around the air bubbles if the bubble radius is above 0.001mm for the sand particles with 0.28mm diameter. Relatively high magnitude of the Hamaker constant for the oil film between sand and air (5.81×10 -20 J for air-oil-sand) indicates that air bubbles have high affinity to attach on the oil film that is on the sand particles in comparison to attaching to the sand particles without the oil film in water (1.60×10 -20 J for air-water-sand). The mobilization mechanism of the contaminated granular particles with gas bubbles can occur in natural environments resulting in transfer of granular particles from sediments to the water column. Copyright © 2016 Elsevier B.V. All rights reserved.

Root architecture simulation improves the inference from seedling root phenotyping towards mature root systems

PubMed Central

Zhao, Jiangsan; Rewald, Boris; Leitner, Daniel; Nagel, Kerstin A.; Nakhforoosh, Alireza

2017-01-01

Abstract Root phenotyping provides trait information for plant breeding. A shortcoming of high-throughput root phenotyping is the limitation to seedling plants and failure to make inferences on mature root systems. We suggest root system architecture (RSA) models to predict mature root traits and overcome the inference problem. Sixteen pea genotypes were phenotyped in (i) seedling (Petri dishes) and (ii) mature (sand-filled columns) root phenotyping platforms. The RSA model RootBox was parameterized with seedling traits to simulate the fully developed root systems. Measured and modelled root length, first-order lateral number, and root distribution were compared to determine key traits for model-based prediction. No direct relationship in root traits (tap, lateral length, interbranch distance) was evident between phenotyping systems. RootBox significantly improved the inference over phenotyping platforms. Seedling plant tap and lateral root elongation rates and interbranch distance were sufficient model parameters to predict genotype ranking in total root length with an RSpearman of 0.83. Parameterization including uneven lateral spacing via a scaling function substantially improved the prediction of architectures underlying the differently sized root systems. We conclude that RSA models can solve the inference problem of seedling root phenotyping. RSA models should be included in the phenotyping pipeline to provide reliable information on mature root systems to breeding research. PMID:28168270

Enhancing learning in geosciences and water engineering via lab activities

NASA Astrophysics Data System (ADS)

Valyrakis, Manousos; Cheng, Ming

2016-04-01

This study focuses on the utilisation of lab based activities to enhance the learning experience of engineering students studying Water Engineering and Geosciences. In particular, the use of modern highly visual and tangible presentation techniques within an appropriate laboratory based space are used to introduce undergraduate students to advanced engineering concepts. A specific lab activity, namely "Flood-City", is presented as a case study to enhance the active engagement rate, improve the learning experience of the students and better achieve the intended learning objectives of the course within a broad context of the engineering and geosciences curriculum. Such activities, have been used over the last few years from the Water Engineering group @ Glasgow, with success for outreach purposes (e.g. Glasgow Science Festival and demos at the Glasgow Science Centre and Kelvingrove museum). The activity involves a specific setup of the demonstration flume in a sand-box configuration, with elements and activities designed so as to gamely the overall learning activity. Social media platforms can also be used effectively to the same goals, particularly in cases were the students already engage in these online media. To assess the effectiveness of this activity a purpose designed questionnaire is offered to the students. Specifically, the questionnaire covers several aspects that may affect student learning, performance and satisfaction, such as students' motivation, factors to effective learning (also assessed by follow-up quizzes), and methods of communication and assessment. The results, analysed to assess the effectiveness of the learning activity as the students perceive it, offer a promising potential for the use of such activities in outreach and learning.

Near surface geophysical techniques on subsoil contamination: laboratory experiments

NASA Astrophysics Data System (ADS)

Capozzoli, Luigi; Giampaolo, Valeria; Rizzo, Enzo

2016-04-01

Hydrocarbons contamination of soil and groundwater has become a serious environmental problem, because of the increasing number of accidental spills caused by human activities. The starting point of any studies is the reconstruction of the conceptual site model. To make valid predictions about the flow pathways following by hydrocarbons compound is necessary to make a correct reconstruction of their characteristics and the environment in which they move. Near-surface geophysical methods, based on the study of electrical and electromagnetic properties, are proved to be very useful in mapping spatial distribution of the organic contaminants in the subsurface. It is well known, in fact, that electrical properties of the porous media are significantly influenced by hydrocarbons because, when contaminants enter the rock matrix, surface reaction occur between the contaminant and the soil grain surface. The main aim of this work is to investigate the capability of near-surface geophysical methods in mapping and monitoring spatial distribution of contaminants in a controlled setting. A laboratory experiment has been performed at the Hydrogeosite Laboratory of CNR-IMAA (Marsico Nuovo, PZ) where a box-sand has been contaminated by diesel. The used contaminant is a LNAPL, added to the sand through a drilled pipe. Contaminant behaviour and its migration paths have been monitored for one year by Electrical Resistivity measurements. In details, a Cross Borehole Electrical Resistivity Tomography techniques were used to characterize the contamination dynamics after a controlled hydrocarbon spillage occurring in the vadose zone. The approach with cross-borehole resistivity imaging provide a great advantage compared to more conventional surface electrical resistivity tomography, due to the high resolution at high depth (obviously depending on the depth of the well instrumented for the acquisition). This method has been shown to provide good information on the distribution of electrical properties of the subsoil at high depths and, in some cases, a detailed assessment of dynamic processes in the subsurface environment (Binley et al., 2002). Our study confirms the link between hydrocarbons contamination and geoelectrical signal and the capability of cross-hole electrical resistivity tomographies to realize a non-invasive characterization of LNAPL contamination of the media. Although, the electrical behaviour is much more complex and the relation with the contaminants depends also by time of investigation.

The jammed-to-mobile transition in frozen sand under stress

NASA Astrophysics Data System (ADS)

Durham, W. B.; Pathare, A.; Stern, L. A.; Lenferink, H. J.

2009-12-01

We conducted laboratory deformation experiments on sand-rich mixtures of sand + ice under sufficient confinement to inhibit macroscopic dilation. Dry sand packs constrained not to dilate when they are under a shearing load reach an immobile or “jammed” state, as load-supporting “force chains” of sand particles form after a small amount of strain and cannot be broken without volume expansion. Our research objective here was to find the minimum volume fraction of ice required to overcome the jammed state. The result surprised us: the required volume fraction is not a fixed number, but depends on the packing characteristics of the sand in question. Experiments were carried out in a triaxial gas deformation rig at confining pressures (60 - 200 MPa) always at least twice the level of differential stresses (11 - 50 MPa) in order to suppress dilatancy. Run temperatures were 223 - 243 K. We used two kinds of quartz sand, one well-sorted, with a maximum dry packing density (MDPD) of about 0.68 sand by volume, and the other a mixture of two sizes, having a higher MDPD of 0.75. Ice volume fraction ranged from well below saturation (where unfilled porosity necessarily remained) to slightly greater than the value of porosity at MDPD. We tested these frozen sands in compression under constant applied differential stress (creep). Strain rates were very low at these conditions, and runs took days or weeks to complete. The amount of strain required to reach the jammed state in ice-undersaturated samples was approximately 0.04, and did not show an obvious dependence on ice content. For both sands, the onset of mobility occurred at approximately 5% above the value of pore volume at MDPD. Furthermore, viscosity of mobile frozen sand near the transition point was extremely sensitive to ice fraction, which implies that at geologic strain rates, far slower than we can reach in the lab, the ice fraction at transition may lie closer to that at MDPD. Cryogenic scanning electron microscopy shows that fracturing of sand grains occurs in ice-undersaturated samples, but gradually disappears as saturation is reached. There are no fractured sand grains in deforming mobile frozen sand packs. One application of this work is to the regolith of Mars at mid-latitudes and poleward, where significant ice is expected to be present. Partially relaxed (“softened”) landforms such as craters require the presence of ice, but also suggest strengths far higher than that of ice. The extreme sensitivity of viscosity to ice content near the mobility boundary, and the near coincidence of mobility and saturation at MDPD together suggest a plausible explanation for partial landform softening on Mars that does not require a fortuitous ice content or an unrealistically brief period of saturation; namely, that the water content of the Martian regolith lies at or near saturation. If true, we can estimate the historical water content of the Martian regolith for reasonable soil densities as being between 120 and 240 global meters of water for the upper kilometer of crust. This is somewhat lower than previous estimates.

BeatBox-HPC simulation environment for biophysically and anatomically realistic cardiac electrophysiology.

PubMed

Antonioletti, Mario; Biktashev, Vadim N; Jackson, Adrian; Kharche, Sanjay R; Stary, Tomas; Biktasheva, Irina V

2017-01-01

The BeatBox simulation environment combines flexible script language user interface with the robust computational tools, in order to setup cardiac electrophysiology in-silico experiments without re-coding at low-level, so that cell excitation, tissue/anatomy models, stimulation protocols may be included into a BeatBox script, and simulation run either sequentially or in parallel (MPI) without re-compilation. BeatBox is a free software written in C language to be run on a Unix-based platform. It provides the whole spectrum of multi scale tissue modelling from 0-dimensional individual cell simulation, 1-dimensional fibre, 2-dimensional sheet and 3-dimensional slab of tissue, up to anatomically realistic whole heart simulations, with run time measurements including cardiac re-entry tip/filament tracing, ECG, local/global samples of any variables, etc. BeatBox solvers, cell, and tissue/anatomy models repositories are extended via robust and flexible interfaces, thus providing an open framework for new developments in the field. In this paper we give an overview of the BeatBox current state, together with a description of the main computational methods and MPI parallelisation approaches.

Intermittent fasting modulation of the diabetic syndrome in sand rats. II. In vivo investigations.

PubMed

Belkacemi, Louiza; Selselet-Attou, Ghalem; Louchami, Karim; Sener, Abdullah; Malaisse, Willy J

2010-11-01

This study deals with the effects of daily intermittent fasting for 15 h upon the development of diabetes in sand rats exposed to a hypercaloric diet. The same pattern of daily intermittent fasting was imposed on sand rats maintained on a purely vegetal diet (control animals). Over the last 30 days of the present experiments, non-fasting animals gained weight, whilst intermittently fasting sand rats lost weight. In this respect, there was no significant difference between control animals and either diabetic or non-diabetic sand rats exposed to the hypercaloric diet. The postprandial glycemia remained fairly stable in the control animals. During a 3-week transition period from a purely vegetal to a hypercaloric diet, the post-prandial glycemia increased by 5.95 ± 1.26 mM (n=6) in diabetic sand rats, as distinct from an increase of only 0.45 ± 0.56 mM (n=6) in the non-diabetic animals. During the intermittent fasting period, the postprandial glycemia decreased significantly in the diabetic animals, but not so in the non-diabetic sand rats. Before the switch in food intake, the peak glycemia at the 30th min of an intraperitoneal glucose tolerance test was already higher in the diabetic than non-diabetic rats. In both the non-diabetic and diabetic sand rats, intermittent fasting prevented the progressive deterioration of glucose tolerance otherwise observed in non-fasting animals. These findings reveal that, at least in sand rats, intermittent daily fasting prevents the progressive deterioration of glucose tolerance otherwise taking place when these animals are exposed to a hypercaloric diet.

2008 Weather and Aeolian Sand-Transport Data from the Colorado River Corridor, Grand Canyon, Arizona

USGS Publications Warehouse

Draut, Amy E.; Sondossi, Hoda A.; Hazel, Joseph E.; Andrews, Timothy; Fairley, Helen C.; Brown, Christopher R.; Vanaman, Karen M.

2009-01-01

This report presents measurements of weather parameters and aeolian (windblown) sand transport made in 2008 near selected archaeological sites in the Colorado River corridor through Grand Canyon, Ariz. The quantitative methods and data discussed here form a basis for monitoring ecosystem processes that affect archeological-site stability. Combined with forthcoming work to evaluate landscape evolution at nearby archaeological sites, these data can be used to document the relationship between physical processes, including weather and aeolian sand transport, and their effects on the physical integrity of archaeological sites. Data collected in 2008 reveal event- and seasonal-scale variations in rainfall, wind, temperature, humidity, and barometric pressure. Broad seasonal changes in aeolian sediment flux are also apparent at most study sites. The continuation of monitoring that began in 2007, and installation of equipment at several new sites in early 2008, allowed evaluation of the effects of the March 2008 high-flow experiment (HFE) on aeolian sand transport. At two of the nine sites studied, spring and summer winds reworked 2008 HFE sandbars to form new aeolian dunes, at which sand moved inland toward larger, well-established dune fields. At the other seven study sites, neither dune formation nor enhanced sand transport after the HFE were observed. At several of those sites, dominant wind directions in spring 2008 were not oriented such that much HFE sand would have moved inland; at other sites, lack of increased inland sand flux is attributable to lack of sandbar enlargement near the study sites or to inhibition of sand movement by vegetation or local topography.

Tracer adsorption in sand-tank experiments of saltwater up-coning

NASA Astrophysics Data System (ADS)

Jakovovic, Danica; Post, Vincent E. A.; Werner, Adrian D.; Männicke, Oliver; Hutson, John L.; Simmons, Craig T.

2012-01-01

SummaryThis study aims to substantiate otherwise unresolved double-peaked plumes produced in recent saltwater up-coning experiments (see Jakovovic et al. (2011), Numerical modelling of saltwater up-coning: Comparison with experimental laboratory observations, Journal of Hydrology 402, 261-273) through additional laboratory testing and numerical modelling. Laboratory experimentation successfully reproduced the double-peaked plume demonstrating that this phenomenon was not an experimental nuance in previous experiments. Numerical modelling by Jakovovic et al. (2011) was extended by considering adsorption effects, which were needed to explain the observed up-coning double peaks of both previous and current laboratory experiments. A linear adsorption isotherm was applied in predicting dye tracer (Rhodamine WT) behaviour in the sand-tank experiments using adsorption parameters obtained experimentally. The same adsorption parameters were tested on all laboratory experiments and it was found that adsorption had insignificant effect on experiments with high pumping rates. However, low pumping rates produced pronounced spatial velocity variations within the dense salt plume beneath the pumping well, with velocities within the plume increasing from the centre of the plume towards the interface. The dye tracer was retarded relative to the salt and was transported preferentially along the higher-velocity paths (i.e. along the edges of the salt plume) towards the well forming double-peaked up-coning patterns. This illustrates the sensitive adsorptive nature of Rhodamine WT and that care should be taken when it is used in similar sand-tank experiments. Observations from this study offer insight into the separation of chemicals in natural systems due to different adsorption characteristics and under conditions of density-dependent flow.

Quark-hadron duality constraints on $$\\gamma Z$$ box corrections to parity-violating elastic scattering

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

Hall, Nathan L.; Blunden, Peter G.; Melnitchouk, Wally

2015-12-08

We examine the interference \\gamma Z box corrections to parity-violating elastic electron--proton scattering in the light of the recent observation of quark-hadron duality in parity-violating deep-inelastic scattering from the deuteron, and the approximate isospin independence of duality in the electromagnetic nucleon structure functions down to Q 2 \\approx 1 GeV 2. Assuming that a similar behavior also holds for the \\gamma Z proton structure functions, we find that duality constrains the γ Z box correction to the proton's weak charge to be Re V γ Z V = (5.4 \\pm 0.4) \\times 10 -3 at the kinematics of the Qmore » weak experiment. Within the same model we also provide estimates of the γ Z corrections for future parity-violating experiments, such as MOLLER at Jefferson Lab and MESA at Mainz.« less

Do chimpanzees (Pan troglodytes) and 2-year-old children (Homo sapiens) understand double invisible displacement?

PubMed

Collier-Baker, Emma; Suddendorf, Thomas

2006-05-01

Chimpanzees (Pan troglodytes) and young children (Homo sapiens) have difficulty with double invisible displacements in which an object is hidden in two nonadjacent boxes in a linear array. Experiment 1 eliminated the possibility that chimpanzees' previous poor performance was due to the hiding direction of the displacement device. As in Call (2001), subjects failed double nonadjacent displacements, showing a tendency to select adjacent boxes. In Experiments 2 and 3, chimpanzees and 24-month-old children were tested on a new adaptation of the task in which four hiding boxes were presented in a diamond-shaped array on a vertical plane. Both species performed above chance on double invisible displacements using this format, suggesting that previous poor performance was due to a response bias or inhibition problem rather than a fundamental limitation in representational capacity. Copyright 2006 APA, all rights reserved.

Carbon turnover in an agricultural sub-soil

NASA Astrophysics Data System (ADS)

Collins, Chris

2010-05-01

Maize was added to a grassland subsoil (10 - 50 cm) and the fate of the carbon from the plant material followed for 520 days with nine sampling points over an exponential time series. The carbon and delta 13C signature in five soil fractions: POM (particulate organic matter), fine sand, coarse silt, fine silt and clay were monitored. Over the course of the experiment there was a 57% decline in the total C of the soil principally from the particulate organic matter which contained the added maize equivalent to a half life of 533 days. A single exponential was the best fit to the data indicating that the slower turnover pools proposed in models such as Roth C were not observed in the time course of this experiment. Carbon rapidly entered the fine sand and coarse silt fractions, it then passed into the clay fraction. The fine silt fraction was not significantly changed. The maize carbon showed a delay to this pattern, but there was accumulation of maize carbon in the fine sand and fine silt fractions. The largest increases in % carbon as a consequence of the introduction of the maize carbon were of the following order clay > fine sand > coarse silt >fine silt. The results suggest that all these fractions are actively being turnover in this soil and that carbon is most protected in the fine sand and silt fractions, not clay as has been observed by other workers. The results are also discussed in the wider contexts of representative pools for modeling.

Virus transport during infiltration of a wetting front into initially unsaturated sand columns.

PubMed

Kenst, Andrew B; Perfect, Edmund; Wilhelm, Steven W; Zhuang, Jie; McCarthy, John F; McKay, Larry D

2008-02-15

We investigated the effect of different flow conditions on the transport of bacteriophage phiX174 in Memphis aquifer sand. Virus transport associated with a wetting front moving into an initially unsaturated horizontal sand column was experimentally compared with that observed under steady-state saturated vertical flow. Results obtained by sectioning the sand columns showthattotal (retained and free) resident virus concentrations decreased approximately exponentially with the travel distance. The rate of decline was similar under both transient unsaturated flow and steady-state saturated flow conditions. Total resident virus concentrations near the inlet were an order of magnitude greater than the virus concentration of the influent solution in both experiments, indicating continuous virus sorption during flow through this zone. Virus retardation was quantified using the ratio of the centroids of the relative saturation and virus concentration versus relative distance functions. The mean retardation factors were 6.43 (coefficient of variation, CV = 14.4%) and 8.22 (CV = 8.22%) for the transient unsaturated and steady-state saturated flow experiments, respectively. Attest indicated no significant difference between these values at P < 0.05. Air-water and air-water-solid interfaces are thought to enhance virus inactivation and sorption to solid particles. The similar retardation factors obtained may be attributable to the reduced presence of these interfaces in the two flow systems investigated as compared to steady-state unsaturated flow experiments in which these interfaces occur throughout the entire column.

Fractal analysis and its impact factors on pore structure of artificial cores based on the images obtained using magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Wang, Heming; Liu, Yu; Song, Yongchen; Zhao, Yuechao; Zhao, Jiafei; Wang, Dayong

2012-11-01

Pore structure is one of important factors affecting the properties of porous media, but it is difficult to describe the complexity of pore structure exactly. Fractal theory is an effective and available method for quantifying the complex and irregular pore structure. In this paper, the fractal dimension calculated by box-counting method based on fractal theory was applied to characterize the pore structure of artificial cores. The microstructure or pore distribution in the porous material was obtained using the nuclear magnetic resonance imaging (MRI). Three classical fractals and one sand packed bed model were selected as the experimental material to investigate the influence of box sizes, threshold value, and the image resolution when performing fractal analysis. To avoid the influence of box sizes, a sequence of divisors of the image was proposed and compared with other two algorithms (geometric sequence and arithmetic sequence) with its performance of partitioning the image completely and bringing the least fitted error. Threshold value selected manually and automatically showed that it plays an important role during the image binary processing and the minimum-error method can be used to obtain an appropriate or reasonable one. Images obtained under different pixel matrices in MRI were used to analyze the influence of image resolution. Higher image resolution can detect more quantity of pore structure and increase its irregularity. With benefits of those influence factors, fractal analysis on four kinds of artificial cores showed the fractal dimension can be used to distinguish the different kinds of artificial cores and the relationship between fractal dimension and porosity or permeability can be expressed by the model of D = a - bln(x + c).

Performance of Choctawhatchee Sand Pine Seedlings Inoculated with Ectomycorrhizal Fungi and Outplanted in the Sandhills of North Florida

Treesearch

John L. Ruehle; Raymond H. Brendemuehl

1981-01-01

Studies were conducted on the effect of the ectomycorrhizal symbiont Pisolifhus tincrorius (Pt) on nursery production and field performance of both container-grown and bare-root Choctawhatchee sand pine (CSP). In two separate experiments, seedlings inoculated with Pt were planted on prepared sites on the sandhills of north Florida. Inoculation with Pt improved the...

Analysis of Non-Uniform Gain for Control of a Deformable Mirror in an Adaptive-Optics System

DTIC Science & Technology

2008-03-01

Turbulence Estimator SM Path SH WFS – DM Path Figure 3.6: Primary layout. The blue boxed components is representative of the SM path, the red boxed components...layout that was developed for the majority of the experiments conducted. 3.1.5.1 Steering Mirror Path. This path, boxed in blue in Figure 3.6, is used to...Christou, T.S. Duncan, R.J. Eager, M.A. Ealey, B.L. Ellerbroek, R.Q. Fugate , G.W. Jones, R.M. Kuhns, D.J. Lee, W.H. Lowrey, M.D. Oliker, R.E. Ruane

Micromechanical investigation of sand migration in gas hydrate-bearing sediments

NASA Astrophysics Data System (ADS)

Uchida, S.; Klar, A.; Cohen, E.

2017-12-01

Past field gas production tests from hydrate bearing sediments have indicated that sand migration is an important phenomenon that needs to be considered for successful long-term gas production. The authors previously developed the continuum based analytical thermo-hydro-mechanical sand migration model that can be applied to predict wellbore responses during gas production. However, the model parameters involved in the model still needs to be calibrated and studied thoroughly and it still remains a challenge to conduct well-defined laboratory experiments of sand migration, especially in hydrate-bearing sediments. Taking the advantage of capability of micromechanical modelling approach through discrete element method (DEM), this work presents a first step towards quantifying one of the model parameters that governs stresses reduction due to grain detachment. Grains represented by DEM particles are randomly removed from an isotropically loaded DEM specimen and statistical analyses reveal that linear proportionality exists between the normalized volume of detached solids and normalized reduced stresses. The DEM specimen with different porosities (different packing densities) are also considered and statistical analyses show that there is a clear transition between loose sand behavior and dense sand behavior, characterized by the relative density.

Disturbance of beach sediment by off-road vehicles

NASA Astrophysics Data System (ADS)

Anders, Fred J.; Leatherman, Stephen P.

1987-10-01

A three-year investigation was undertaken to examine the effects of off-road vehicles (ORVs) on the beach at Fire Island, New York. Within the National Seashore over 45,000 vehicle trips per year are concentrated in the zone seaward of the dune toe. The experimental approach was adopted in order to assess the environmental effects of ORVs. Specially developed instrumentation was used to measure the direct displacement of sand by vehicles traversing the beach. Direct displacement data were reduced graphically and analyzed by stepwise linear regression. The results of 89 field experiments (788 cases) showed that slope, sand compaction, and number of vehicle passes in the same track were the principal factors controlling the measured net seaward displacement of sand. The data suggest that ORV use levels within the National Seashore could be contributing to the overall erosion rate by delivering large quantities of sand to the swash zone (max. of 119,300 m3/yr). However, with proper management downslope movement of sand could be reduced by an order of magnitude. While vehicular passage over the open beach displaces sand seaward, it is not known if such activity actually increases the amount of erosion, measured as net loss to the beach face.

KENNEDY SPACE CENTER, FLA. - The apparatus shown was designed to hold microcapsules for research on mission STS-107. It is one over several included in the Commercial ITA Biomedical Experiments payload. The box was recently recovered during the search for Columbia debris. The drug delivery system and spaceflight hardware was developed jointly by JSC, the Institute for Research Inc. and Instrumentation Technology Associates Inc. to conduct microencapsulation experiments under microgravity conditions.

NASA Image and Video Library

2003-05-06

KENNEDY SPACE CENTER, FLA. - The apparatus shown was designed to hold microcapsules for research on mission STS-107. It is one over several included in the Commercial ITA Biomedical Experiments payload. The box was recently recovered during the search for Columbia debris. The drug delivery system and spaceflight hardware was developed jointly by JSC, the Institute for Research Inc. and Instrumentation Technology Associates Inc. to conduct microencapsulation experiments under microgravity conditions.

Filling box stratification fed by a gravity current

NASA Astrophysics Data System (ADS)

Hogg, Charlie; Huppert, Herbert; Imberger, Jorg

2012-11-01

Fluids in confined basins can be stratified by the filling box mechanism. The source of dense fluid in geophysical applications, such as a cold river entering a warmer lake, can be a gravity current running over a shallow slope. Filling box models are often, however, based on the dynamics of vertically falling, unconfined, plumes which entrain fluid by a different mechanism to gravity currents on shallow slopes. Laboratory tank experiments of a filling box fed by a gravity current running over a shallow slope were carried out using a dye attenuation technique to investigate the development of the stratification of the ambient. These results demonstrate the differences in the stratification generated by a gravity current compared to that generated by a plume and demonstrate the nature of entrainment into gravity currents on shallow slopes.

Vector soup: high-throughput identification of Neotropical phlebotomine sand flies using metabarcoding.

PubMed

Kocher, Arthur; Gantier, Jean-Charles; Gaborit, Pascal; Zinger, Lucie; Holota, Helene; Valiere, Sophie; Dusfour, Isabelle; Girod, Romain; Bañuls, Anne-Laure; Murienne, Jerome

2017-03-01

Phlebotomine sand flies are haematophagous dipterans of primary medical importance. They represent the only proven vectors of leishmaniasis worldwide and are involved in the transmission of various other pathogens. Studying the ecology of sand flies is crucial to understand the epidemiology of leishmaniasis and further control this disease. A major limitation in this regard is that traditional morphological-based methods for sand fly species identifications are time-consuming and require taxonomic expertise. DNA metabarcoding holds great promise in overcoming this issue by allowing the identification of multiple species from a single bulk sample. Here, we assessed the reliability of a short insect metabarcode located in the mitochondrial 16S rRNA for the identification of Neotropical sand flies, and constructed a reference database for 40 species found in French Guiana. Then, we conducted a metabarcoding experiment on sand flies mixtures of known content and showed that the method allows an accurate identification of specimens in pools. Finally, we applied metabarcoding to field samples caught in a 1-ha forest plot in French Guiana. Besides providing reliable molecular data for species-level assignations of phlebotomine sand flies, our study proves the efficiency of metabarcoding based on the mitochondrial 16S rRNA for studying sand fly diversity from bulk samples. The application of this high-throughput identification procedure to field samples can provide great opportunities for vector monitoring and eco-epidemiological studies. © 2016 John Wiley & Sons Ltd.

Does box model training improve surgical dexterity and economy of movement during virtual reality laparoscopy? A randomised trial.

PubMed

Clevin, Lotte; Grantcharov, Teodor P

2008-01-01

Laparoscopic box model trainers have been used in training curricula for a long time, however data on their impact on skills acquisition is still limited. Our aim was to validate a low cost box model trainer as a tool for the training of skills relevant to laparoscopic surgery. Randomised, controlled trial (Canadian Task Force Classification I). University Hospital. Sixteen gynaecologic residents with limited laparoscopic experience were randomised to a group that received a structured box model training curriculum, and a control group. Performance before and after the training was assessed in a virtual reality laparoscopic trainer (LapSim and was based on objective parameters, registered by the computer system (time, error, and economy of motion scores). Group A showed significantly greater improvement in all performance parameters compared with the control group: economy of movement (p=0.001), time (p=0.001) and tissue damage (p=0.036), confirming the positive impact of box-trainer curriculum on laparoscopic skills acquisition. Structured laparoscopic skill training on a low cost box model trainer improves performance as assessed using the VR system. Trainees who used the box model trainer showed significant improvement compared to the control group. Box model trainers are valid tools for laparoscopic skills training and should be implemented in the comprehensive training curricula in gynaecology.

Impacts into quartz sand: Crater formation, shock metamorphism, and ejecta distribution in laboratory experiments and numerical models

NASA Astrophysics Data System (ADS)

Wünnemann, Kai; Zhu, Meng-Hua; Stöffler, Dieter

2016-10-01

We investigated the ejection mechanics by a complementary approach of cratering experiments, including the microscopic analysis of material sampled from these experiments, and 2-D numerical modeling of vertical impacts. The study is based on cratering experiments in quartz sand targets performed at the NASA Ames Vertical Gun Range. In these experiments, the preimpact location in the target and the final position of ejecta was determined by using color-coded sand and a catcher system for the ejecta. The results were compared with numerical simulations of the cratering and ejection process to validate the iSALE shock physics code. In turn the models provide further details on the ejection velocities and angles. We quantify the general assumption that ejecta thickness decreases with distance according to a power-law and that the relative proportion of shocked material in the ejecta increase with distance. We distinguish three types of shock metamorphic particles (1) melt particles, (2) shock lithified aggregates, and (3) shock-comminuted grains. The agreement between experiment and model was excellent, which provides confidence that the models can predict ejection angles, velocities, and the degree of shock loading of material expelled from a crater accurately if impact parameters such as impact velocity, impactor size, and gravity are varied beyond the experimental limitations. This study is relevant for a quantitative assessment of impact gardening on planetary surfaces and the evolution of regolith layers on atmosphereless bodies.

Three-Month-Old infants Attribute Goals to a Non-Human Agent

ERIC Educational Resources Information Center

Luo, Yuyan

2011-01-01

The present research examined whether 3-month-old infants, the youngest found so far to engage in goal-related reasoning about human agents, would also act as if they attribute goals to a novel non-human agent, a self-propelled box. In two experiments, the infants seemed to have interpreted the box's actions as goal-directed after seeing the box…

Box-Behnken Design of Experiments Investigation of Hydroxyapatite Synthesis for Orthopedic Applications

NASA Astrophysics Data System (ADS)

Kehoe, S.; Stokes, J.

2011-03-01

Physicochemical properties of hydroxyapatite (HAp) synthesized by the chemical precipitation method are heavily dependent on the chosen process parameters. A Box-Behnken three-level experimental design was therefore, chosen to determine the optimum set of process parameters and their effect on various HAp characteristics. These effects were quantified using design of experiments (DoE) to develop mathematical models using the Box-Behnken design, in terms of the chemical precipitation process parameters. Findings from this research show that the HAp possessing optimum powder characteristics for orthopedic application via a thermal spray technique can therefore be prepared using the following chemical precipitation process parameters: reaction temperature 60 °C, ripening time 48 h, and stirring speed 1500 rpm using high reagent concentrations. Ripening time and stirring speed significantly affected the final phase purity for the experimental conditions of the Box-Behnken design. An increase in both the ripening time (36-48 h) and stirring speed (1200-1500 rpm) was found to result in an increase of phase purity from 47(±2)% to 85(±2)%. Crystallinity, crystallite size, lattice parameters, and mean particle size were also optimized within the research to find desired settings to achieve results suitable for FDA regulations.

Cadmium removal from urban stormwater runoff via bioretention technology and effluent risk assessment for discharge to surface water.

PubMed

Wang, Jianlong; Zhang, Pingping; Yang, Liqiong; Huang, Tao

2016-01-01

Bioretention technology, a low-impact development stormwater management measure, was evaluated for its ability to remove heavy metals (specifically cadmium, Cd) from urban stormwater runoff. Fine sand, zeolite, sand and quartz sand were selected as composite bioretention media. The effects of these materials on the removal efficiency, chemical forms, and accumulation and migration characteristics of Cd were examined in laboratory scale bioretention columns. Heretofore, few studies have examined the removal of Cd by bioretention. A five-step sequential extraction method, a single-contamination index method, and an empirical migration equation were used in the experiments. The average Cd removal efficiency of quartz sand approached 99%, and removal by the other media all exceeded 90%. The media types markedly affected the forms of Cd found in the columns as well as its vertical migration rate. The Cd accumulated in the four media was mainly in residual form; moreover, accumulation of Cd occurred mainly in the surface layer of the bioretention column. The migration depth of Cd in the four media increased with elapsed time, in the following sequence: zeolite>quartz sand>fine sand>sand. In contrast, the migration rate decreased with elapsed time, and the migration rate of Cd was lowest in sand (0.015 m per annum over the first ten years). The comprehensive risk index analysis indicated that the risk arising from Cd discharge to surface water was "intermediate", and that the degree of risk was lowest in sand, then quartz sand, zeolite, and fine sand in sequence. These results indicate that the adsorption and accumulation of Cd in the four media are more significant than the migration of Cd. In addition, the results of Cd risk assessment for the effluent indicate that each of the four media can serve as long-term adsorption material in a bioretention facility for purifying stormwater runoff. Copyright © 2016 Elsevier B.V. All rights reserved.

Anaesthesia in a disaster zone: a report on the experience of an Australian medical team in Banda Aceh following the 'Boxing Day Tsunami'.

PubMed

Paix, B R; Capps, R; Neumeister, G; Semple, T

2005-10-01

We report on the experience of a 23-member Australian medical team in Banda Aceh, Indonesia, following the 2004 Boxing Day tsunami. Arriving 13 days after the tsunami that devastated the city, killed 100,000 of its inhabitants and injured thousands more, we carried out 130 surgical procedures in austere conditions over a 12-day period. Most surgery was peripheral, principally for plastic surgical or orthopaedic procedures to lower limb injuries. Intravenous ketamine anaesthesia was the technique of choice, with good surgical conditions and few significant side-effects.

Cofactor-dependent specificity of a DEAD-box protein.

PubMed

Young, Crystal L; Khoshnevis, Sohail; Karbstein, Katrin

2013-07-16

DEAD-box proteins, a large class of RNA-dependent ATPases, regulate all aspects of gene expression and RNA metabolism. They can facilitate dissociation of RNA duplexes and remodeling of RNA-protein complexes, serve as ATP-dependent RNA-binding proteins, or even anneal duplexes. These proteins have highly conserved sequence elements that are contained within two RecA-like domains; consequently, their structures are nearly identical. Furthermore, crystal structures of DEAD-box proteins with bound RNA reveal interactions exclusively between the protein and the RNA backbone. Together, these findings suggest that DEAD-box proteins interact with their substrates in a nonspecific manner, which is confirmed in biochemical experiments. Nevertheless, this contrasts with the need to target these enzymes to specific substrates in vivo. Using the DEAD-box protein Rok1 and its cofactor Rrp5, which both function during maturation of the small ribosomal subunit, we show here that Rrp5 provides specificity to the otherwise nonspecific biochemical activities of the Rok1 DEAD-domain. This finding could reconcile the need for specific substrate binding of some DEAD-box proteins with their nonspecific binding surface and expands the potential roles of cofactors to specificity factors. Identification of helicase cofactors and their RNA substrates could therefore help define the undescribed roles of the 19 DEAD-box proteins that function in ribosome assembly.

Border-oriented post-processing refinement on detected vehicle bounding box for ADAS

NASA Astrophysics Data System (ADS)

Chen, Xinyuan; Zhang, Zhaoning; Li, Minne; Li, Dongsheng

2018-04-01

We investigate a new approach for improving localization accuracy of detected vehicles for object detection in advanced driver assistance systems(ADAS). Specifically, we implement a bounding box refinement as a post-processing of the state-of-the-art object detectors (Faster R-CNN, YOLOv2, etc.). The bounding box refinement is achieved by individually adjusting each border of the detected bounding box to its target location using a regression method. We use HOG features which perform well on the edge detection of vehicles to train the regressor and the regressor is independent of the CNN-based object detectors. Experiment results on the KITTI 2012 benchmark show that we can achieve up to 6% improvements over YOLOv2 and Faster R-CNN object detectors on the IoU threshold of 0.8. Also, the proposed refinement framework is computationally light, allowing for processing one bounding box within a few milliseconds on CPU. Further, this refinement method can be added to any object detectors, especially those with high speed but less accuracy.

Buckling and Post-Buckling Behaviors of a Variable Stiffness Composite Laminated Wing Box Structure

NASA Astrophysics Data System (ADS)

Wang, Peiyan; Huang, Xinting; Wang, Zhongnan; Geng, Xiaoliang; Wang, Yuansheng

2018-04-01

The buckling and post-buckling behaviors of variable stiffness composite laminates (VSCL) with curvilinear fibers were investigated and compared with constant stiffness composite laminates (CSCL) with straight fibers. A VSCL box structure was evaluated under a pure bending moment. The results of the comparative test showed that the critical buckling load of the VSCL box was approximately 3% higher than that of the CSCL box. However, the post-buckling load-bearing capacity was similar due to the layup angle and the immature status of the material processing technology. The properties of the VSCL and CSCL boxes under a pure bending moment were simulated using the Hashin criterion and cohesive interface elements. The simulation results are consistent with the experimental results in stiffness, critical buckling load and failure modes but not in post-buckling load capacity. The results of the experiment, the simulation and laminated plate theory show that VSCL greatly improves the critical buckling load but has little influence on the post-buckling load-bearing capacity.

Interaction force in a vertical dust chain inside a glass box.

PubMed

Kong, Jie; Qiao, Ke; Matthews, Lorin S; Hyde, Truell W

2014-07-01

Small number dust particle clusters can be used as probes for plasma diagnostics. The number of dust particles as well as cluster size and shape can be easily controlled employing a glass box placed within a Gaseous Electronics Conference (GEC) rf reference chamber to provide confinement of the dust. The plasma parameters inside this box and within the larger plasma chamber have not yet been adequately defined. Adjusting the rf power alters the plasma conditions causing structural changes of the cluster. This effect can be used to probe the relationship between the rf power and other plasma parameters. This experiment employs the sloshing and breathing modes of small cluster oscillations to examine the relationship between system rf power and the particle charge and plasma screening length inside the glass box. The experimental results provided indicate that both the screening length and dust charge decrease as rf power inside the box increases. The decrease in dust charge as power increases may indicate that ion trapping plays a significant role in the sheath.

Does the Well-Being of Individuals with Down Syndrome and Dementia Improve When Using Life Story Books and Rummage Boxes? A Randomized Single Case Series Experiment.

PubMed

Crook, Nicola; Adams, Malcolm; Shorten, Nicola; Langdon, Peter E

2016-01-01

This study investigated whether a personalized life story book and rummage box enhanced well-being and led to changes in behaviour for people with Down syndrome (DS) who have dementia. A randomized single case series design was used with five participants who had DS and a diagnosis of dementia. Participants were invited to take part in three conditions at random (i) life story book, (ii) rummage box and (iii) no-intervention condition. The two reminiscence conditions were significantly associated with enhanced well-being as compared to the no-intervention condition. However, for one participant, the life story book was associated with significantly higher well-being, while for another participant, the rummage box was associated with significantly higher well-being, suggesting some participants may prefer one method over another. Personalized life story books and rummage boxes are associated with higher levels of well-being for people with DS and dementia. © 2015 John Wiley & Sons Ltd.

Learning to avoid spiders: fear predicts performance, not competence.

PubMed

Luo, Xijia; Becker, Eni S; Rinck, Mike

2018-01-05

We used an immersive virtual environment to examine avoidance learning in spider-fearful participants. In 3 experiments, participants were asked to repeatedly lift one of 3 virtual boxes, under which either a toy car or a spider appeared and then approached the participant. Participants were not told that the probability of encountering a spider differed across boxes. When the difference was large (Exps. 1 and 2), spider-fearfuls learned to avoid spiders by lifting the few-spiders-box more often and the many-spiders-box less often than non-fearful controls did. However, they hardly managed to do so when the probability differences were small (Exp. 3), and they did not escape from threat more quickly (Exp. 2). In contrast to the observed performance differences, spider-fearfuls and non-fearfuls showed equal competence, that is comparable post-experimental knowledge about the probability to encounter spiders under the 3 boxes. The limitations and implications of the present study are discussed.

Can an agent’s false belief be corrected by an appropriate communication? Psychological reasoning in 18-month-old infants

PubMed Central

Song, Hyun-joo; Onishi, Kristine H.; Baillargeon, Renée; Fisher, Cynthia

2008-01-01

Do 18-month-olds understand that an agent’s false belief can be corrected by an appropriate, though not an inappropriate, communication? In Experiment 1, infants watched a series of events involving two agents, a ball, and two containers: a box and a cup. To start, agent1 played with the ball and then hid it in the box, while agent2 looked on. Next, in agent1’s absence, agent2 moved the ball from the box to the cup. When agent1 returned, agent2 told her “The ball is in the cup!” (informative-intervention condition) or “I like the cup!” (uninformative-intervention condition). During test, agent1 reached for either the box (box event) or the cup (cup event). In the informative-intervention condition, infants who saw the box event looked reliably longer than those who saw the cup event; in the uninformative-intervention condition, the reverse pattern was found. These results suggest that infants expected agent1’s false belief about the ball’s location to be corrected when she was told “The ball is in the cup!”, but not “I like the cup!”. In Experiment 2, agent2 simply pointed to the ball’s new location, and infants again expected agent1’s false belief to be corrected. These and control results provide additional evidence that infants in the second year of life can attribute false beliefs to agents. In addition, the results suggest that by 18 months of age infants expect agents’ false beliefs to be corrected by relevant communications involving words or gestures. PMID:18976745

2007 Weather and Aeolian Sand-Transport Data from the Colorado River Corridor, Grand Canyon, Arizona

USGS Publications Warehouse

Draut, Amy E.; Andrews, Timothy; Fairley, Helen C.; Brown, Christopher R.

2009-01-01

Weather data constitute an integral part of ecosystem monitoring in the Colorado River corridor and are particularly valuable for understanding processes of landscape change that contribute to the stability of archeological sites. Data collected in 2007 are reported from nine weather stations in the Colorado River corridor through Grand Canyon, Ariz. The stations were deployed in February and March 2007 to measure wind speed and direction, rainfall, air temperature, relative humidity, and barometric pressure. Sand traps near each weather station collect windblown sand, from which daily aeolian sand-transport rates are calculated. The data reported here were collected as part of an ongoing study to test and evaluate methods for quantifying processes that affect the physical integrity of archeological sites along the river corridor; as such, these data can be used to identify rainfall events capable of causing gully incision and to predict likely transport pathways for aeolian sand, two landscape processes integral to the preservation of archeological sites. Weather data also have widespread applications to other studies of physical, cultural, and biological resources in Grand Canyon. Aeolian sand-transport data reported here, collected in the year before the March 2008 High-Flow Experiment (HFE) at Glen Canyon Dam, represent baseline data against which the effects of the 2008 HFE on windblown sand will be compared in future reports.

Astronaut James D. van Hoften examines student experiment on Challenger

NASA Technical Reports Server (NTRS)

1984-01-01

Astronaut James D. van Hoften, 41-C mission specialist, holds an aluminum box full of honeybees. The experiment in earth orbit is duplicated with another colony of the bees on earth. This is an experiment submitted by student researchers.

Chladni Patterns on Drumheads: A ``Physics of Music'' Experiment

NASA Astrophysics Data System (ADS)

Worland, Randy

2011-01-01

In our "Physics of Music" class for non-science majors, we have developed a laboratory exercise in which students experiment with Chladni sand patterns on drumheads. Chladni patterns provide a kinesthetic, visual, and entertaining way to illustrate standing waves on flat surfaces and are very helpful when making the transition from one-dimensional systems, such as string and wind instruments, to the two-dimensional membranes and plates of the percussion family. Although the sand patterns attributed to Ernst Florens Friedrich Chladni (1756-1827) are often demonstrated for this purpose using metal plates,2-4 the use of drumheads offers several pedagogical and practical advantages in the lab.

Three-link Swimming in Sand

NASA Astrophysics Data System (ADS)

Hatton, R. L.; Ding, Yang; Masse, Andrew; Choset, Howie; Goldman, Daniel

2011-11-01

Many animals move within in granular media such as desert sand. Recent biological experiments have revealed that the sandfish lizard uses an undulatory gait to swim within sand. Models reveal that swimming occurs in a frictional fluid in which inertial effects are small and kinematics dominate. To understand the fundamental mechanics of swimming in granular media (GM), we examine a model system that has been well-studied in Newtonian fluids: the three-link swimmer. We create a physical model driven by two servo-motors, and a discrete element simulation of the swimmer. To predict optimal gaits we use a recent geometric mechanics theory combined with empirically determined resistive force laws for GM. We develop a kinematic relationship between the swimmer's shape and position velocities and construct connection vector field and constraint curvature function visualizations of the system dynamics. From these we predict optimal gaits for forward, lateral and rotational motion. Experiment and simulation are in accord with the theoretical predictions; thus geometric tools can be used to study locomotion in GM.

Sexual orientation and spatial memory.

PubMed

Cánovas, Ma Rosa; Cimadevilla, José Manuel

2011-11-01

The present study aimed at determining the influence of sexual orientation in human spatial learning and memory. Participants performed the Boxes Room, a virtual reality version of the Holeboard. In Experiment I, a reference memory task, the position of the hidden rewards remained constant during the whole experiment. In Experiment II, a working memory task, the position of rewards changed between blocks. Each block consisted of two trials: One trial for acquisition and another for retrieval. The results of Experiment I showed that heterosexual men performed better than homosexual men and heterosexual women. They found the rewarded boxes faster. Moreover, homosexual participants committed more errors than heterosexuals. Experiment II showed that working memory abilities are the same in groups of different sexual orientation. These results suggest that sexual orientation is related to spatial navigation abilities, but mostly in men, and limited to reference memory, which depends more on the function of the hippocampal system.

Biological CO2 conversion to acetate in subsurface coal-sand formation using a high-pressure reactor system.

PubMed

Ohtomo, Yoko; Ijiri, Akira; Ikegawa, Yojiro; Tsutsumi, Masazumi; Imachi, Hiroyuki; Uramoto, Go-Ichiro; Hoshino, Tatsuhiko; Morono, Yuki; Sakai, Sanae; Saito, Yumi; Tanikawa, Wataru; Hirose, Takehiro; Inagaki, Fumio

2013-01-01

Geological CO2 sequestration in unmineable subsurface oil/gas fields and coal formations has been proposed as a means of reducing anthropogenic greenhouse gasses in the atmosphere. However, the feasibility of injecting CO2 into subsurface depends upon a variety of geological and economic conditions, and the ecological consequences are largely unpredictable. In this study, we developed a new flow-through-type reactor system to examine potential geophysical, geochemical and microbiological impacts associated with CO2 injection by simulating in-situ pressure (0-100 MPa) and temperature (0-70°C) conditions. Using the reactor system, anaerobic artificial fluid and CO2 (flow rate: 0.002 and 0.00001 ml/min, respectively) were continuously supplemented into a column comprised of bituminous coal and sand under a pore pressure of 40 MPa (confined pressure: 41 MPa) at 40°C for 56 days. 16S rRNA gene analysis of the bacterial components showed distinct spatial separation of the predominant taxa in the coal and sand over the course of the experiment. Cultivation experiments using sub-sampled fluids revealed that some microbes survived, or were metabolically active, under CO2-rich conditions. However, no methanogens were activated during the experiment, even though hydrogenotrophic and methylotrophic methanogens were obtained from conventional batch-type cultivation at 20°C. During the reactor experiment, the acetate and methanol concentration in the fluids increased while the δ(13)Cacetate, H2 and CO2 concentrations decreased, indicating the occurrence of homo-acetogenesis. 16S rRNA genes of homo-acetogenic spore-forming bacteria related to the genus Sporomusa were consistently detected from the sandstone after the reactor experiment. Our results suggest that the injection of CO2 into a natural coal-sand formation preferentially stimulates homo-acetogenesis rather than methanogenesis, and that this process is accompanied by biogenic CO2 conversion to acetate.

Biological CO2 conversion to acetate in subsurface coal-sand formation using a high-pressure reactor system

PubMed Central

Ohtomo, Yoko; Ijiri, Akira; Ikegawa, Yojiro; Tsutsumi, Masazumi; Imachi, Hiroyuki; Uramoto, Go-Ichiro; Hoshino, Tatsuhiko; Morono, Yuki; Sakai, Sanae; Saito, Yumi; Tanikawa, Wataru; Hirose, Takehiro; Inagaki, Fumio

2013-01-01

Geological CO2 sequestration in unmineable subsurface oil/gas fields and coal formations has been proposed as a means of reducing anthropogenic greenhouse gasses in the atmosphere. However, the feasibility of injecting CO2 into subsurface depends upon a variety of geological and economic conditions, and the ecological consequences are largely unpredictable. In this study, we developed a new flow-through-type reactor system to examine potential geophysical, geochemical and microbiological impacts associated with CO2 injection by simulating in-situ pressure (0–100 MPa) and temperature (0–70°C) conditions. Using the reactor system, anaerobic artificial fluid and CO2 (flow rate: 0.002 and 0.00001 ml/min, respectively) were continuously supplemented into a column comprised of bituminous coal and sand under a pore pressure of 40 MPa (confined pressure: 41 MPa) at 40°C for 56 days. 16S rRNA gene analysis of the bacterial components showed distinct spatial separation of the predominant taxa in the coal and sand over the course of the experiment. Cultivation experiments using sub-sampled fluids revealed that some microbes survived, or were metabolically active, under CO2-rich conditions. However, no methanogens were activated during the experiment, even though hydrogenotrophic and methylotrophic methanogens were obtained from conventional batch-type cultivation at 20°C. During the reactor experiment, the acetate and methanol concentration in the fluids increased while the δ13Cacetate, H2 and CO2 concentrations decreased, indicating the occurrence of homo-acetogenesis. 16S rRNA genes of homo-acetogenic spore-forming bacteria related to the genus Sporomusa were consistently detected from the sandstone after the reactor experiment. Our results suggest that the injection of CO2 into a natural coal-sand formation preferentially stimulates homo-acetogenesis rather than methanogenesis, and that this process is accompanied by biogenic CO2 conversion to acetate. PMID:24348470

Lithofacies and seismic-reflection interpretation of temperate glacimarine sedimentation in Tarr Inlet, Glacier Bay, Alaska

USGS Publications Warehouse

Cai, J.; Powell, R.D.; Cowan, E.A.; Carlson, P.R.

1997-01-01

High-resolution seismic-reflection profiles of sediment fill within Tart Inlet of Glacier Bay, Alaska, show seismic facies changes with increasing distance from the glacial termini. Five types of seismic facies are recognized from analysis of Huntec and minisparker records, and seven lithofacies are determined from detailed sedimentologic study of gravity-, vibro- and box-cores, and bottom grab samples. Lithofacies and seismic facies associations, and fjord-floor morphology allow us to divide the fjord into three sedimentary environments: ice-proximal, iceberg-zone and ice-distal. The ice-proximal environment, characterized by a morainal-bank depositional system, can be subdivided into bank-back, bank-core and bank-front subenvironments, each of which is characterized by a different depositional subsystem. A bank-back subsystem shows chaotic seismic facies with a mounded surface, which we infer consists mainly of unsorted diamicton and poorly sorted coarse-grained sediments. A bank-core depositional subsystem is a mixture of diamicton, rubble, gravel, sand and mud. Seismic-reflection records of this subsystem are characterized by chaotic seismic facies with abundant hyperbolic diffractions and a hummocky surface. A bank-front depositional subsystem consists of mainly stratified and massive sand, and is characterized by internal hummocky facies on seismic-reflection records with significant surface relief and sediment gravity flow channels. The depositional system formed in the iceberg-zone environment consists of rhythmically laminated mud interbedded with thin beds of weakly stratified diamicton and stratified or massive sand and silt. On seismic-reflection profiles, this depositional system is characterized by discontinuously stratified facies with multiple channels on the surface in the proximal zone and a single channel on the largely flat sediment surface in the distal zone. The depositional system formed in the ice-distal environment consists of interbedded homogeneous or laminated mud and massive or stratified sand and coarse silt. This depositional system shows continuously stratified seismic facies with smooth and flat surfaces on minisparker records, and continuously stratified seismic facies which are interlayered with thin weakly stratified facies on Huntec records.

An Experimental Study on the Impact of Different-frequency Elastic Waves on Water Retention Curve

NASA Astrophysics Data System (ADS)

Deng, J. H.; Dai, J. Y.; Lee, J. W.; Lo, W. C.

2017-12-01

ABSTEACTOver the past few decades, theoretical and experimental studies on the connection between elastic wave attributes and the physical properties of a fluid-bearing porous medium have attracted the attention of many scholars in fields of porous medium flow and hydrogeology. It has been previously determined that the transmission of elastic waves in a porous medium containing two immiscible fluids will have an effect on the water retention curve, but it has not been found that the water retention curve will be affected by the frequency of elastic vibration waves or whether the effect on the soil is temporary or permanent. This research is based on a sand box test in which the soil is divided into three layers (a lower, middle, and upper layer). In this case, we discuss different impacts on the water retention curve during the drying process under sound waves (elastic waves) subject to three frequencies (150Hz, 300Hz, and 450Hz), respectively. The change in the water retention curve before and after the effect is then discussed. In addition, how sound waves affect the water retention curve at different depths is also observed. According to the experimental results, we discover that sound waves can cause soil either to expand or to contract. When the soil is induced to expand due to sound waves, it can contract naturally and return to the condition it was in before the influence of the sound waves. On the contrary, when the soil is induced to contract, it is unable to return to its initial condition. Due to the results discussed above, it is suggested that sound waves causing soil to expand have a temporary impact while those causing soil to contract have a permanent impact. In addition, our experimental results show how sound waves affect the water retention curve at different depths. The degree of soil expansion and contraction caused by the sound waves will differ at various soil depths. Nevertheless, the expanding or contracting of soil is only subject to the frequency of sound waves. Key words: Elastic waves, Water retention curve, Sand box test.

Experimental sand burial affects seedling survivorship, morphological traits, and biomass allocation of Ulmus pumila var. sabulosa in the Horqin Sandy Land, China

NASA Astrophysics Data System (ADS)

Tang, Jiao; Busso, Carlos Alberto; Jiang, Deming; Musa, Ala; Wu, Dafu; Wang, Yongcui; Miao, Chunping

2016-07-01

As a native tree species, Ulmus pumila var. sabulosa (sandy elm) is widely distributed in the Horqin Sandy Land, China. However, seedlings of this species have to withstand various depths of sand burial after emergence because of increasing soil degradation, which is mainly caused by overgrazing, climate change, and wind erosion. An experiment was conducted to evaluate the changes in its survivorship, morphological traits, and biomass allocation when seedlings were buried at different burial depths: unburied controls and seedlings buried vertically up to 33, 67, 100, or 133 % of their initial mean seedling height. The results showed that partial sand burial treatments (i.e., less than 67 % burial) did not reduce seedling survivorship, which still reached 100 %. However, seedling mortality increased when sand burial was equal to or greater than 100 %. In comparison with the control treatment, seedling height and stem diameter increased at least by 6 and 14 % with partial burial, respectively. In the meantime, seedling taproot length, total biomass, and relative mass growth rates were at least enhanced by 10, 15.6, and 27.6 %, respectively, with the partial sand burial treatment. Furthermore, sand burial decreased total leaf area and changed biomass allocation in seedlings, partitioning more biomass to aboveground organs (e.g., leaves) and less to belowground parts (roots). Complete sand burial after seedling emergence inhibited its re-emergence and growth, even leading to death. Our findings indicated that seedlings of sandy elm showed some resistance to partial sand burial and were adapted to sandy environments from an evolutionary perspective. The negative effect of excessive sand burial after seedling emergence might help in understanding failures in recruitments of sparse elm in the study region.

Miles Discusses Experiment With NASA Personnel

NASA Technical Reports Server (NTRS)

1972-01-01

Lexington, Massachusetts high school student, Judith Miles, discusses her proposed Skylab experiment with Keith Demorest (right) and Henry Floyd, both of Marshall Space Flight Center (MSFC). In her experiment, called the 'Web Formation in Zero Gravity', called for spiders to be released into a box and their actions recorded to determine how well they adapt to the absence of gravity. Spiders are known to adapt quickly to other changes in the environment but nothing was known of their ability to adapt to weightlessness. At the same time spiders were weaving webs in Earth orbit, similar spiders were spinning webs in identical boxes on Earth under full gravity conditions. Miles was among the 25 winners of a contest in which some 3,500 high school students proposed experiments for the following year's Skylab Mission. Of the 25 students, 6 did not see their experiments conducted on Skylab because the experiments were not compatible with Skylab hardware and timelines. Of the 19 remaining, 11 experiments required the manufacture of equipment.

How to understand the tunneling in attosecond experiment?. Bohr-Einstein photon box Gedanken experiment, tunneling time and the wave particle duality

NASA Astrophysics Data System (ADS)

Kullie, Ossama

2018-02-01

The measurement of the tunneling time (T-time) in today's attosecond and strong field (low-frequency) experiments, despite its controversial discussion, offers a fruitful opportunity to understand time measurement and the time in quantum mechanics. In addition, as we will see in this work, a related controversial issue is the particulate nature of the radiation. The T-time in attosecond experiment and its different aspects and models, is discussed in this work, especially in relation to my model of real T-time (Kullie, 2015), where a good agreement with the experiment and an intriguing similarity to the Bohr-Einstein photon box Gedanken experiment was found. The tunneling process itself is still not well understood, but I am arguing that a scattering mechanism (by the laser wave packet) offers a possibility to understand the tunneling process in the tunneling region. This is related to the question about the corpuscular nature of light which is widely discussed in modern quantum optics experiments.

Sorption of Cesium on smectite-rich clays from the Bohemian Massif (Czech Republic) and their mixtures with sand.

PubMed

Vejsada, J; Jelínek, E; Randa, Z; Hradil, D; Prikryl, R

2005-01-01

Sorption is an important process for the transport of radionuclides through backfill materials in a radioactive waste underground repository. Within this study, sorption of Cs on selected Czech clay materials and their mixtures with sand was investigated by batch tests. The experiments were performed under oxic conditions at 25 degrees C. Synthetic groundwater as a liquid phase and unconditioned clays (as they were provided by their producer) were used to reach the natural conditions as close as possible. Distribution ratios (Rds) of Cs for all selected clays rise with increase of the clay fraction in clay/sand mixtures in agreement with previous works studying sorption behaviour of such mixtures. The rise of Rds is from 10(2) cm3 g(-1) for mixtures with 80% of sand to 10(3) cm3 g(-1) for pure clays. There are significant differences between natural and technologically modified clays.

Dynamic response of sand particles impacted by a rigid spherical object

NASA Astrophysics Data System (ADS)

Youplao, P.; Takita, A.; Nasbey, H.; Yupapin, P. P.; Fujii, Y.

2018-06-01

A method for measuring the dynamic impact responses that acting on a spherical object while dropping and colliding with dried sand, such as the velocity, displacement, acceleration, and resultant force, is presented and discussed. In the experiment, a Michelson-type laser interferometer is employed to obtain the velocity of the spherical stainless steel object. Then the obtained time velocity profile is used to calculate the acceleration, the displacement, and the inertial force acting on the observed sand particles. Furthermore, a high-speed camera is employed to observe the behavior of the sand during the collision. From the experimental results with the sampling interval for frequencies calculation of 1 ms, the combined standard uncertainty in the instantaneous value of the impact force acts on the observed object is obtained and approximated to 0.49 N, which is related to a corresponding 4.07% of the maximum value at 12.05 N of the impact force.

Technical note: Application of the Box-Cox data transformation to animal science experiments.

PubMed

Peltier, M R; Wilcox, C J; Sharp, D C

1998-03-01

In the use of ANOVA for hypothesis testing in animal science experiments, the assumption of homogeneity of errors often is violated because of scale effects and the nature of the measurements. We demonstrate a method for transforming data so that the assumptions of ANOVA are met (or violated to a lesser degree) and apply it in analysis of data from a physiology experiment. Our study examined whether melatonin implantation would affect progesterone secretion in cycling pony mares. Overall treatment variances were greater in the melatonin-treated group, and several common transformation procedures failed. Application of the Box-Cox transformation algorithm reduced the heterogeneity of error and permitted the assumption of equal variance to be met.

Surface instabilities in shock loaded granular media

NASA Astrophysics Data System (ADS)

Kandan, K.; Khaderi, S. N.; Wadley, H. N. G.; Deshpande, V. S.

2017-12-01

The initiation and growth of instabilities in granular materials loaded by air shock waves are investigated via shock-tube experiments and numerical calculations. Three types of granular media, dry sand, water-saturated sand and a granular solid comprising PTFE spheres were experimentally investigated by air shock loading slugs of these materials in a transparent shock tube. Under all shock pressures considered here, the free-standing dry sand slugs remained stable while the shock loaded surface of the water-saturated sand slug became unstable resulting in mixing of the shocked air and the granular material. By contrast, the PTFE slugs were stable at low pressures but displayed instabilities similar to the water-saturated sand slugs at higher shock pressures. The distal surfaces of the slugs remained stable under all conditions considered here. Eulerian fluid/solid interaction calculations, with the granular material modelled as a Drucker-Prager solid, reproduced the onset of the instabilities as seen in the experiments to a high level of accuracy. These calculations showed that the shock pressures to initiate instabilities increased with increasing material friction and decreasing yield strain. Moreover, the high Atwood number for this problem implied that fluid/solid interaction effects were small, and the initiation of the instability is adequately captured by directly applying a pressure on the slug surface. Lagrangian calculations with the directly applied pressures demonstrated that the instability was caused by spatial pressure gradients created by initial surface perturbations. Surface instabilities are also shown to exist in shock loaded rear-supported granular slugs: these experiments and calculations are used to infer the velocity that free-standing slugs need to acquire to initiate instabilities on their front surfaces. The results presented here, while in an idealised one-dimensional setting, provide physical understanding of the conditions required to initiate instabilities in a range of situations involving the explosive dispersion of particles.

The importance of pH and sand substrate in the revegetation of saline non-waterlogged peat fields.

PubMed

Montemayor, Marilou B; Price, Jonathan; Rochefort, Line

2015-11-01

A partially peat-extracted coastal bog contaminated by seawater was barren and required revegetation as a wetland. Peat fields were rectangular in shape, cambered in cross-section profile, and separated by drainage ditches. Common to all peat fields were symmetrical patterns in micro-topography with slopes between differences in elevation. Saline non-waterlogged slopes of ∼5% occurred as a symmetrical pair on each side of the crest of the cambered profile, at one end of each peat field. Three rows were laid across this slope (Top, Middle, and Bottom rows) and transplanted with naturally-growing plant species with their sand substrate, in three experiments, and grown for a year. In the Spartina pectinata experiment, bare root stem sections were also planted. Another experiment was conducted to determine changes in the characteristics of a volume of sand when incubated in saline peat fields. We found the salinity of peat increased with moisture downslope, and pH decreased with increase in salinity. S. pectinata grew best when planted with its sand substrate compared with bare root stem section, and when planted in Bottom rows. Juncus balticus had excellent growth in all rows. Unexpectedly, Festuca rubra that was inconspicuous beneath the J. balticus canopy in the natural donor site grew densely within the J. balticus sods. Agrostis stolonifera grew well but seemed to show intolerance to the surrounding acidic peat by curling up its stolons. The pH of the incubated sand volume was much higher than the surrounding peat. These studies suggest that recognition of plant niches and pH manipulation are important in the revegetation of disturbed Sphagnum peatlands that are found abundantly in the northern hemisphere. Results are also relevant to the reclamation of other disturbed lands. Copyright © 2015 Elsevier Ltd. All rights reserved.

The improvement of surface roughness by polishing method of arcylic door panel at Taishi Tech Sdn Bhd

NASA Astrophysics Data System (ADS)

Basirin, Hammadi bin Mohd; Nawi, Ismail bin Haji Mohd

2017-04-01

This research is an approach to improve the surface roughness for acrylic door panel by using polishing process. The polishing process involve is sanding process by 3 types of sand paper. The sanding process used to improve the surface roughness by using the different grit sizes of sand paper. The experiment was done by using two types of material s, that is plywood and medium density board (MDF). These two materials are the main materials in producing the arcrylic door panel. The surface roughness of these two materials affects the qualities and quantities of the acrylic door panel. The surface structure was measured by using Optical Microscope and Scanning Electron Microscope (SEM) and the surface roughness was measured by using Mitutoyo surfest SJ 400 Tester. Results indicates that using the different types of grit are influence the surface roughness of the material. When the higher types of grit sizes had been used, the average roughness of the surface are decrease. In summary, a good surface roughness condition produced when using the higher types of grit sizes sand paper.

[A test of the focusing hypothesis for category judgment: an explanation using the mental-box model].

PubMed

Hatori, Tsuyoshi; Takemura, Kazuhisa; Fujii, Satoshi; Ideno, Takashi

2011-06-01

This paper presents a new model of category judgment. The model hypothesizes that, when more attention is focused on a category, the psychological range of the category gets narrower (category-focusing hypothesis). We explain this hypothesis by using the metaphor of a "mental-box" model: the more attention that is focused on a mental box (i.e., a category set), the smaller the size of the box becomes (i.e., a cardinal number of the category set). The hypothesis was tested in an experiment (N = 40), where the focus of attention on prescribed verbal categories was manipulated. The obtained data gave support to the hypothesis: category-focusing effects were found in three experimental tasks (regarding the category of "food", "height", and "income"). The validity of the hypothesis was discussed based on the results.

What boxing-related stimuli reveal about response behaviour.

PubMed

Ottoboni, Giovanni; Russo, Gabriele; Tessari, Alessia

2015-01-01

When two athletes meet inside the ropes of the boxing ring to fight, their cognitive systems have to respond as quickly as possible to a manifold of stimuli to assure victory. In the present work, we studied the pre-attentive mechanisms, which form the basis of an athlete's ability in reacting to an opponent's punches. Expert boxers, beginner boxers and people with no experience of boxing performed a Simon-like task where they judged the colour of the boxing gloves worn by athletes in attack postures by pressing two lateralised keys. Although participants were not instructed to pay attention to the direction of the punches, beginner boxers' responses resembled a defence-related pattern, expert boxers' resembled counterattacks, whereas non-athletes' responses were not influenced by the unrelated task information. Results are discussed in the light of an expertise-related action simulation account.

Force-Sensing Enhanced Simulation Environment (ForSense) for laparoscopic surgery training and assessment.

PubMed

Cundy, Thomas P; Thangaraj, Evelyn; Rafii-Tari, Hedyeh; Payne, Christopher J; Azzie, Georges; Sodergren, Mikael H; Yang, Guang-Zhong; Darzi, Ara

2015-04-01

Excessive or inappropriate tissue interaction force during laparoscopic surgery is a recognized contributor to surgical error, especially for robotic surgery. Measurement of force at the tool-tissue interface is, therefore, a clinically relevant skill assessment variable that may improve effectiveness of surgical simulation. Popular box trainer simulators lack the necessary technology to measure force. The aim of this study was to develop a force sensing unit that may be integrated easily with existing box trainer simulators and to (1) validate multiple force variables as objective measurements of laparoscopic skill, and (2) determine concurrent validity of a revised scoring metric. A base plate unit sensitized to a force transducer was retrofitted to a box trainer. Participants of 3 different levels of operative experience performed 5 repetitions of a peg transfer and suture task. Multiple outcome variables of force were assessed as well as a revised scoring metric that incorporated a penalty for force error. Mean, maximum, and overall magnitudes of force were significantly different among the 3 levels of experience, as well as force error. Experts were found to exert the least force and fastest task completion times, and vice versa for novices. Overall magnitude of force was the variable most correlated with experience level and task completion time. The revised scoring metric had similar predictive strength for experience level compared with the standard scoring metric. Current box trainer simulators can be adapted for enhanced objective measurements of skill involving force sensing. These outcomes are significantly influenced by level of expertise and are relevant to operative safety in laparoscopic surgery. Conventional proficiency standards that focus predominantly on task completion time may be integrated with force-based outcomes to be more accurately reflective of skill quality. Copyright © 2015 Elsevier Inc. All rights reserved.

Survival of Salmonella adelaide and fecal coliforms in coarse sands of the swan costal plain, Western Australia.

PubMed Central

Parker, W F; Mee, B J

1982-01-01

The survival of Salmonella adelaide and fecal coliforms in two coarse sands influenced by two sources of septic tank effluent was studied. The experiments were conducted in conditions that reflected the soil environment beneath functioning septic tank systems. Significant differences in survival were found with different effluent sources. In one experiment the survival of S. adelaide was similar to that of fecal coliforms; in the other it was not. The nonuniform, multiphasic nature of survival curves was variability observed in these experiments suggests that the application of such survival data for establishing management criteria for septic tank systems--by, for example, the use of soil moisture characteristic curves to give estimates of movement in the soil--is inappropriate. PMID:7103482

Surfactant enhanced remediation of soil columns contaminated by residual tetrachloroethylene

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

Pennell, K.D.; Jin, M.; Abriola, L.M.

1994-01-01

The ability of aqueous surfactant solutions to recover tetrachloroethylene (PCE) entrapped in Ottawa sand was evaluated in four column experiments. Residual PCE was emplaced by injecting (14)C-labeled PCE into water-saturated soil columns and displacing the free product with water. Miscible displacement experiments were conducted before and after PCE entrapment to determine the influence or residual PCE on column dispersivities. The first two column studies involved the injection of a 4% solution of polyoxyethylene (POE) (20) sorbitan monooleate, resulting in the removal of 90% and 97% of the residual PCE from 20-30- and 40-120-mesh Ottawa sand, respectively. Although micellar solubilization ofmore » PCE was the primary mode of recovery in these experiments, this process was shown to be rate-limited.« less

Construction of an evidence-based, graduated training curriculum for D-box, a webcam-based laparoscopic basic skills trainer box.

PubMed

Debes, Anders J; Aggarwal, Rajesh; Balasundaram, Indran; Jacobsen, Morten B J

2012-06-01

Surgical training programs are now including simulators as training tools for teaching laparoscopic surgery. The aim of this study was to develop a standardized, graduated, and evidence-based curriculum for the newly developed D-box (D-box Medical, Lier, Norway) for training basic laparoscopic skills. Eighteen interns with no laparoscopic experience completed a training program on the D-box consisting of 8 sessions of 5 tasks with assessment on a sixth task. Performance was measured by the use of 3-dimensional electromagnetic tracking of hand movements, path length, and time taken. Ten experienced surgeons (>100 laparoscopic surgeries, median 250) were recruited for establishing benchmark criteria. Significant learning curves were obtained for all construct valid parameters for tasks 4 (P < .005) and 5 (P < .005) and reached plateau levels between the fifth and sixth session. Within the 8 sessions of this study, between 50% and 89% of the interns reached benchmark criteria on tasks 4 and 5. Benchmark criteria and an evidence-based curriculum have been developed for the D-box. The curriculum is aimed at training and assessing surgical novices in basic laparoscopic skills. Copyright © 2012 Elsevier Inc. All rights reserved.

Interaction between the phage HK022 Nun protein and the nut RNA of phage lambda.

PubMed

Chattopadhyay, S; Hung, S C; Stuart, A C; Palmer, A G; Garcia-Mena, J; Das, A; Gottesman, M E

1995-12-19

The nun gene product of prophage HK022 excludes phage lambda infection by blocking the expression of genes downstream from the lambda nut sequence. The Nun protein functions both by competing with lambda N transcription-antitermination protein and by actively inducing transcription termination on the lambda chromosome. We demonstrate that Nun binds directly to a stem-loop structure within nut RNA, boxB, which is also the target for the N antiterminator. The two proteins show comparable affinities for boxB and they compete with each other. Their interactions with boxB are similar, as shown by RNase protection experiments, NMR spectroscopy, and analysis of boxB mutants. Each protein binds the 5' strand of the boxB stem and the adjacent loop. The stem does not melt upon the binding of Nun or N, as the 3' strand remains sensitive to a double-strand-specific RNase. The binding of RNA partially protects Nun from proteolysis and changes its NMR spectra. Evidently, although Nun and N bind to the same surface of boxB RNA, their respective complexes interact differently with RNA polymerase, inducing transcription termination or antitermination, respectively.

Rotational Diffusion Depends on Box Size in Molecular Dynamics Simulations.

PubMed

Linke, Max; Köfinger, Jürgen; Hummer, Gerhard

2018-06-07

We show that the rotational dynamics of proteins and nucleic acids determined from molecular dynamics simulations under periodic boundary conditions suffer from significant finite-size effects. We remove the box-size dependence of the rotational diffusion coefficients by adding a hydrodynamic correction k B T/6 ηV with k B Boltzmann's constant, T the absolute temperature, η the solvent shear viscosity, and V the box volume. We show that this correction accounts for the finite-size dependence of the rotational diffusion coefficients of horse-heart myoglobin and a B-DNA dodecamer in aqueous solution. The resulting hydrodynamic radii are in excellent agreement with experiment.

Black Box Testing: Experiments with Runway Incursion Advisory Alerting System

NASA Technical Reports Server (NTRS)

Mukkamala, Ravi

2005-01-01

This report summarizes our research findings on the Black box testing of Runway Incursion Advisory Alerting System (RIAAS) and Runway Safety Monitor (RSM) system. Developing automated testing software for such systems has been a problem because of the extensive information that has to be processed. Customized software solutions have been proposed. However, they are time consuming to develop. Here, we present a less expensive, and a more general test platform that is capable of performing complete black box testing. The technique is based on the classification of the anomalies that arise during Monte Carlo simulations. In addition, we also discuss a generalized testing tool (prototype) that we have developed.

AN INDIRECT METHOD TO ASSAY FOR MITOTIC CENTERS IN SAND DOLLAR (DENDRASTER EXCENTRICUS) EGGS

PubMed Central

Went, Hans A.

1966-01-01

It is possible consistently to induce sea urchin and sand dollar eggs to cleave directly from one cell into four cells. This is done by exposing the fertilized eggs to benzimidazole for 20 to 30 min beginning about early metaphase. The mitotic apparatus regresses, the cells do not cleave, and shortly after they are returned to normal sea water an early-prophase-appearing nucleus is present in each cell. Each cell then organizes a tetrapolar tetrahedral mitotic apparatus de novo, instead of transforming a bipolar mitotic apparatus into a tetrapolar figure, and cleaves one-to-four. In another type of experiment, it appears that sand dollar eggs exposed to mercaptoethanol during the first period of mitotic center duplication have only half as many centers by first cleavage metaphase as the normal controls. This is consistent with an earlier report by Mazia et al (1960). Using this same experimental technique, it was demonstrated that benzimidazole, on the contrary, does not interfere with mitotic center duplication in sand dollar eggs. A labeling experiment demonstrated that benzimidazole does not interfere markedly with the normal pattern of incorporation of C14-thymidine into the DNA of sea urchin eggs. The data reported here suggest that judicious treatment of sand dollar eggs (and probably sea urchin eggs, too) with benzimidazole can induce the eggs to cleave into as many cells as there were mitotic centers sometime earlier, for example at early metaphase of the first cleavage division. This provides a very useful tool for studies on the process of mitotic center duplication. PMID:6008198

An indirect method to assay for mitotic centers in sand dollar (Dendraster excentricus) eggs.

PubMed

Went, H A

1966-09-01

It is possible consistently to induce sea urchin and sand dollar eggs to cleave directly from one cell into four cells. This is done by exposing the fertilized eggs to benzimidazole for 20 to 30 min beginning about early metaphase. The mitotic apparatus regresses, the cells do not cleave, and shortly after they are returned to normal sea water an early-prophase-appearing nucleus is present in each cell. Each cell then organizes a tetrapolar tetrahedral mitotic apparatus de novo, instead of transforming a bipolar mitotic apparatus into a tetrapolar figure, and cleaves one-to-four. In another type of experiment, it appears that sand dollar eggs exposed to mercaptoethanol during the first period of mitotic center duplication have only half as many centers by first cleavage metaphase as the normal controls. This is consistent with an earlier report by Mazia et al (1960). Using this same experimental technique, it was demonstrated that benzimidazole, on the contrary, does not interfere with mitotic center duplication in sand dollar eggs. A labeling experiment demonstrated that benzimidazole does not interfere markedly with the normal pattern of incorporation of C(14)-thymidine into the DNA of sea urchin eggs. The data reported here suggest that judicious treatment of sand dollar eggs (and probably sea urchin eggs, too) with benzimidazole can induce the eggs to cleave into as many cells as there were mitotic centers sometime earlier, for example at early metaphase of the first cleavage division. This provides a very useful tool for studies on the process of mitotic center duplication.

Influence of porewater advection on denitrification in carbonate sands: Evidence from repacked sediment column experiments

NASA Astrophysics Data System (ADS)

Santos, Isaac R.; Eyre, Bradley D.; Glud, Ronnie N.

2012-11-01

Porewater flow enhances mineralization rates in organic-poor permeable sands. Here, a series of sediment column experiments were undertaken to assess the potential effect of advective porewater transport on denitrification in permeable carbonate sands collected from Heron Island (Great Barrier Reef). Experimental conditions (flow path length, advection rate, and temperature) were manipulated to represent conditions similar to near shore tropical environments. HgCl2-poisoned controls were used to assess whether reactions were microbially mediated. Overall, significant correlations were found between oxygen consumption and N2 production. The N:O2 slope of 0.114 implied that about 75% of all the nitrogen mineralized was denitrified. A 4-fold increase in sediment column length (from 10 to 40 cm) resulted in an overall increase in oxygen consumption (1.6-fold), TCO2 production (1.8-fold), and denitrification (1.9-fold). Oxic respiration increased quickly until advection reached 80 L m-2 h-1 and then plateaued at higher advection rates. Interestingly, denitrification peaked (up to 336 μmol N2 m-2 h-1) at intermediate advection rates (30-80 L m-2 h-1). We speculate that intermediate advection rates enhance the development of microniches (i.e., steep oxygen gradients) within porous carbonate sands, perhaps providing optimum conditions for denitrification. The denitrification peak fell within the broad range of advection rates (often on scales of 1-100 L m-2 h-1) typically found on continental shelves implying that carbonate sands may play a major, but as yet unquantified, role in oceanic nitrogen budgets.

New Experiences in Dike Construction with Soil-Ash Composites and Fine-Grained Dredged Materials

NASA Astrophysics Data System (ADS)

Duszyński, Remigiusz; Duszyńska, Angelika; Cantré, Stefan

2017-12-01

The supporting structure inside a coastal dike is often made of dredged non-uniform sand with good compaction properties. Due to the shortage of natural construction material for both coastal and river dikes and the surplus of different processed materials, new experiments were made with sand-ash mixtures and fine-grained dredged materials to replace both dike core and dike cover materials resulting in economical, environmentally friendly and sustainable dikes. Ash from EC Gdańsk and dredged sand from the Vistula river were mixed to form an engineering material used for dike construction. The optimum sand-ash composites were applied at a field test site to build a large-scale research dike. Fine-grained dredged materials from Germany were chosen to be applied in a second full-scale research dike in Rostock. All materials were investigated according to the standards for soil mechanical analysis. This includes basic soil properties, mechanical characteristics, such as grain-size distribution, compaction parameters, compressibility, shear strength, and water permeability. In the field, the infiltration of water into the dike body as well as the erosion resistance of the cover material against overflowing water was determined. Results of both laboratory and field testing are discussed in this paper. In conclusion, the mixing of bottom ash with mineral soil, such as relatively uniform dredged sand, fairly improves the geotechnical parameters of the composite, compared to the constituents. Depending on the composite, the materials may be suitable to build a dike core or an erosion-resistant dike cover.

Field observations of artificial sand and oil agglomerates

USGS Publications Warehouse

Dalyander, Patricia (Soupy); Long, Joseph W.; Plant, Nathaniel G.; McLaughlin, Molly R.; Mickey, Rangley C.

2015-01-01

Oil that comes into the surf zone following spills, such as occurred during the 2010 Deepwater Horizon (DWH) blowout, can mix with local sediment to form heavier-than-water sand and oil agglomerates (SOAs), at times in the form of mats a few centimeters thick and tens of meters long. Smaller agglomerates that form in situ or pieces that break off of larger mats, sometimes referred to as surface residual balls (SRBs), range in size from sand-sized grains to patty-shaped pieces several centimeters (cm) in diameter. These mobile SOAs can cause beach oiling for extended periods following the spill, on the scale of years as in the case of DWH. Limited research, including a prior effort by the U.S. Geological Survey (USGS) investigating SOA mobility, alongshore transport, and seafloor interaction using numerical model output, focused on the physical dynamics of SOAs. To address this data gap, we constructed artificial sand and oil agglomerates (aSOAs) with sand and paraffin wax to mimic the size and density of genuine SOAs. These aSOAs were deployed in the nearshore off the coast of St. Petersburg, Florida, during a field experiment to investigate their movement and seafloor interaction. This report presents the methodology for constructing aSOAs and describes the field experiment. Data acquired during the field campaign, including videos and images of aSOA movement in the nearshore (1.5-meter and 0.5-meter water depth) and in the swash zone, are also presented in this report.

Effects of biosolids and compost amendment on chemistry of soils contaminated with copper from mining activities.

PubMed

Sidhu, Virinder; Sarkar, Dibyendu; Datta, Rupali

2016-03-01

Several million metric tons of mining wastes, called stamp sands, were generated in the Upper Peninsula of Michigan during extensive copper (Cu) mining activities in the past. These materials, containing large amounts of Cu, were discharged into various offshoots of Lake Superior. Due to evidences of Cu toxicity on aquatic organisms, in due course, the materials were dredged and dumped on lake shores, thus converting these areas into vast, fallow lands. Erosion of these Cu-contaminated stamp sands back to the lakes is severely affecting aquatic life. A lack of uniform vegetation cover on stamp sands is facilitating this erosion. Understanding the fact that unless the stamp sands are fertilized to the point of sustaining vegetation growth, the problem with erosion and water quality degradation will continue, amending the stamp sands with locally available biosolids and composts, was considered. The purpose of the reported study was to assess potential effects of such organic fertilizer amendments on soil quality. As the first step of a combined laboratory and greenhouse study, a 2-month-long incubation experiment was performed to investigate the effects of biosolids and compost addition on the soil nutrient profile of stamp sands and organic matter content. Results showed that both biosolids and compost amendments resulted in significant increase in nitrogen and phosphorus concentrations and organic matter contents of stamp sands. Sequential extraction data demonstrated that Cu was mostly present as bound forms in stamp sands, and there was no significant increase in the plant available fraction of Cu because of fertilizer application.

Seasonal persistence and population characteristics of Escherichia coli and entercocci in deep backshore sand of two freshwater beaches

USGS Publications Warehouse

Byappanahalli, M.N.; Whitman, R.L.; Shively, D.A.; Ting, W.T.E.; Tseng, C.C.; Nevers, M.B.

2006-01-01

We studied the shoreward and seasonal distribution of E. coli and enterococci in sand (at the water table) at two southern Lake Michigan beaches - Dunbar and West Beach (in Indiana). Deep, backshore sand (??? 20 m inland) was regularly sampled for 15 months during 2002-2003. E. coli counts were not significantly different in samples taken at 5-m intervals from 0-40 M inland (P = 0.25). Neither E. coli nor enterococci mean counts showed any correlation or differences between the two beaches studied. In laboratory experiments, E. coli readily grew in sand supplemented with lake plankton, suggesting that in situ E. coli growth may occur when temperature and natural organic sources are adequate. Of the 114 sand enterococci isolates tested, positive species identification was obtained for only 52 (46%), with E. faecium representing the most dominant species (92%). Genetic characterization by ribotyping revealed no distinct genotypic pattern (s) for E. coli, suggesting that the sand population was rather a mixture of numerous strains (genotypes). These findings indicate that E. coli and enterococci can occur and persist for extended periods in backshore sand at the groundwater table. Although this study was limited to two beaches of southern Lake Michigan, similar findings can be expected at other temperate freshwater beaches. The long-term persistence of these bacteria, perhaps independent of pollution events, complicates their use as indicator organisms. Further, backshore sand at the water table may act as a reservoir for these bacteria and potentially for human pathogens. ?? IWA Publishing 2006.

Attenuation of sound in sand sediments due to porosity fluctuations.

PubMed

Hefner, Brian T; Jackson, Darrell R

2014-08-01

At high frequencies, the attenuation measured in sand sediments is larger than that predicted by Biot theory. To account for this discrepancy, perturbation theory is used to incorporate losses due to scattering by porosity variations into both Biot's poroelastic equations and the effective density fluid model. While previous results showed that fluctuations in the bulk frame modulus were insufficient to produce significant attenuation in a sand sediment, modest levels of fluctuations in the porosity produce significant scattering loss. By using the sediment parameters and the heterogeneity power spectrum measured during the Sediment Acoustics Experiment in 2004, the perturbation theory result shows good agreement with the sound speed and attenuation data without any free parameters.

Dispersants as Used in Response to the MC252-Spill Lead to Higher Mobility of Polycyclic Aromatic Hydrocarbons in Oil-Contaminated Gulf of Mexico Sand

PubMed Central

Zuijdgeest, Alissa; Huettel, Markus

2012-01-01

After the explosion of the Deepwater Horizon oil rig, large volumes of crude oil were washed onto and embedded in the sandy beaches and sublittoral sands of the Northern Gulf of Mexico. Some of this oil was mechanically or chemically dispersed before reaching the shore. With a set of laboratory-column experiments we show that the addition of chemical dispersants (Corexit 9500A) increases the mobility of polycyclic aromatic hydrocarbons (PAHs) in saturated permeable sediments by up to two orders of magnitude. Distribution and concentrations of PAHs, measured in the solid phase and effluent water of the columns using GC/MS, revealed that the mobility of the PAHs depended on their hydrophobicity and was species specific also in the presence of dispersant. Deepest penetration was observed for acenaphthylene and phenanthrene. Flushing of the columns with seawater after percolation of the oiled water resulted in enhanced movement by remobilization of retained PAHs. An in-situ benthic chamber experiment demonstrated that aromatic hydrocarbons are transported into permeable sublittoral sediment, emphasizing the relevance of our laboratory column experiments in natural settings. We conclude that the addition of dispersants permits crude oil components to penetrate faster and deeper into permeable saturated sands, where anaerobic conditions may slow degradation of these compounds, thus extending the persistence of potentially harmful PAHs in the marine environment. Application of dispersants in nearshore oil spills should take into account enhanced penetration depths into saturated sands as this may entail potential threats to the groundwater. PMID:23209777

Microgravity

NASA Image and Video Library

1989-10-17

Sand boil or sand volcano measuring 2 m (6.6 ft.) in length erupted in median of Interstate Highway 80 west of the Bay Bridge toll plaza when ground shaking transformed loose water-saturated deposit of subsurface sand into a sand-water slurry (liquefaction) in the October 17, 1989, Loma Prieta earthquake. Vented sand contains marine-shell fragments. Sand and soil grains have faces that can cause friction as they roll and slide against each other, or even cause sticking and form small voids between grains. This complex behavior can cause soil to behave like a liquid under certain conditions such as earthquakes or when powders are handled in industrial processes. Mechanics of Granular Materials (MGM) experiments aboard the Space Shuttle use the microgravity of space to simulate this behavior under conditions that carnot be achieved in laboratory tests on Earth. MGM is shedding light on the behavior of fine-grain materials under low effective stresses. Applications include earthquake engineering, granular flow technologies (such as powder feed systems for pharmaceuticals and fertilizers), and terrestrial and planetary geology. Nine MGM specimens have flown on two Space Shuttle flights. Another three are scheduled to fly on STS-107. The principal investigator is Stein Sture of the University of Colorado at Boulder. (Credit: J.C. Tinsley, U.S. Geological Survey)

Toward a mechanistic understanding of the effect of biochar addition on soil water retention

NASA Astrophysics Data System (ADS)

Yi, S.; Chang, N.; Guo, M.; Imhoff, P. T.

2014-12-01

Biochar (BC) is a carbon-rich product produced by thermal degradation of biomass in an oxygen-free environment, whose application to sediment is said to improve water retention. However, BC produced from different feedstocks and pyrolyzed at different temperatures have distinct properties, which may alter water retention in ways difficult to predict a priori. Our goal is to develop a mechanistic understanding of BC addition on water retention by examining the impact of BC from two feedstocks, poultry litter (PL) and hardwood (HW), on the soil-water retention curves (SWRC) of a uniform sand and a sandy loam (SL). For experiments with sand, BC and sand were sieved to the same particle size (~ 0.547 mm) to minimize effects of BC addition on particle size distribution. Experiments with SL contained the same sieved BC. PL and HW bicohars were added at 2 and 7% (w/w), and water retention was measured from 0 to -4.38 × 106 cm-H2O. Both BCs increased porosities for sand and SL, up to 39 and 13% for sand and SL, respectively, with 7% HW BC addition. The primary cause for these increases was the internal porosity of BC particles. While the matric potential for air-entry was unchanged with BC addition, BC amendment increased water retention for sand and SL in the capillary region (0 to -15,000 cm-H2O) by an average of 26 and 33 % for 7% PL and HW BC in sand, respectively, but only 7 and 14 % for 7% PL and HW BC in SL. The most dramatic influence of BC amendment on water retention occurred in the adsorption region (< -15,000 cm-H2O), where water retention increased by a factor of 11 and 22 for 7% PL and HW BC in sand, respectively, but by 140 and 190 % for 7% PL and HW BC in SL, respectively. The impact of BC on water retention in these sediments is explained primarily by the additional surface area and internal porosity of PL and HW BC particles. van Genuchten (VG) models were fitted to the water retention data. For SL where the impact of BC addition on water retention was less significant, a unimodal model fit water retention data well for unamended and BC-amended media: the addition of BC did not create a new class of small pores that could not be described with a unimodal VG model. While a unimodal model fitted the sand data well, a bimodal model was required for all BC-amended sand. The influence of BC type, mass fraction and sediment on water retention models will be discussed.

Salix alba and Populus nigra seedlings resistance to physical hydro-sedimentary stresses: nursery experimental approach compared to in situ measurements

NASA Astrophysics Data System (ADS)

Wintenberger, Coraline; Rodrigues, Stephane; Breheret, Jean-Gabriel; Jugé, Philippe; Villar, Marc

2014-05-01

In Europe, riparian Salicaceae is declining following the loss of potential germination areas associated with river management. Nevertheless, as an exception for lowland rivers, the Loire River (France) shows in its middle reaches an efficient sexual regeneration of Populus nigra and Salix alba species on bare sediments deposited during flood events. The study focuses on the influence of flow, sediment dynamics and fluvial maintenance operations on the establishment and survival of black poplar and white willow seedlings during the first year of development in a lowland sandy-gravel river, the Middle Loire. Main questions are: what is the influence of morphological and sedimentary features on seedlings recruitment and how do they withstand the hydro-sedimentary stresses occurring during high flow periods? How fluvial management works, and induced morphology and sedimentary features, modify the sediment dynamics and subsequent establishment and maintenance of seedlings? To answer these questions, we developed an ex-situ approach which allowed, under controlled conditions, to determine the influence of the sedimentological characteristics of the substrate on the development and maintenance of seedlings with a specific focus on the root system. Three experiments were carried out for three sedimentary mixtures from the river (sand, sand-gravel and 0.2 m of sand superimposed on sand-gravel mixture) that correspond to grain size and stratigraphy conditions often observed on bars and secondary channels in the Loire. The experimental design includes 108 plots of 1 m3, with 400 seeds per plot (corresponding to the Loire density measurements) and combining seeds from two species, three sedimentary mixtures, four replicates and three experiments. Experiment 1 (control) is based on the architecture of root systems using the WinRHIZO image analysis software. Experiment 2 is relative to the evaluation of constraints leading to "uprooting" of seedlings. Experiment 3 provides data on the seedlings survival once buried during a flood event. Genetic diversity of the seed lots will be investigated via biomass and shoot / root ratio. Results reveal that willow seedlings have a higher density of roots compared to poplar. In sand mixture, poplar has a taproot system; in sand-gravel mixture, taproot is divided into several roots which leads to a branched root system. The required forces to uprooting are twice much important for sand-gravel mixture. In situ measurements detail the sediment dynamics and morphological evolution during and after floods (topography, scour/fill processes, grain size surveys, flow velocity, sediment transport rates) on a managed alluvial bar. Results associated with floods occurring after fluvial management works highlight the rapid regeneration of bedforms associated with sedimentary and hydraulics constraints. This leads to the development of new morphological and sedimentological units, suitable for seedlings recruitment. Thirty plots measurements of seedlings (densities and species) established were associated with these news physical conditions over the bar. Black poplar and white willow appeared for a wide range of grain sizes and on specific morphological units. Seedlings survival will be analyzed with regard to physical constraints determined for each plot from measurements of hydro-sedimentary dynamics and then compared to ex situ results.

Numerical and experimental investigation of DNAPL removal mechanisms in a layered porous medium by means of soil vapor extraction.

PubMed

Yoon, Hongkyu; Oostrom, Mart; Wietsma, Thomas W; Werth, Charles J; Valocchi, Albert J

2009-10-13

The purpose of this work is to identify the mechanisms that govern the removal of carbon tetrachloride (CT) during soil vapor extraction (SVE) by comparing numerical and analytical model simulations with a detailed data set from a well-defined intermediate-scale flow cell experiment. The flow cell was packed with a fine-grained sand layer embedded in a coarse-grained sand matrix. A total of 499 mL CT was injected at the top of the flow cell and allowed to redistribute in the variably saturated system. A dual-energy gamma radiation system was used to determine the initial NAPL saturation profile in the fine-grained sand layer. Gas concentrations at the outlet of the flow cell and 15 sampling ports inside the flow cell were measured during subsequent CT removal using SVE. Results show that CT mass was removed quickly in coarse-grained sand, followed by a slow removal from the fine-grained sand layer. Consequently, effluent gas concentrations decreased quickly at first, and then started to decrease gradually, resulting in long-term tailing. The long-term tailing was mainly due to diffusion from the fine-grained sand layer to the coarse-grained sand zone. An analytical solution for a one-dimensional advection and a first-order mass transfer model matched the tailing well with two fitting parameters. Given detailed knowledge of the permeability field and initial CT distribution, we were also able to predict the effluent concentration tailing and gas concentration profiles at sampling ports using a numerical simulator assuming equilibrium CT evaporation. The numerical model predictions were accurate within the uncertainty of independently measured or literature derived parameters. This study demonstrates that proper numerical modeling of CT removal through SVE can be achieved using equilibrium evaporation of NAPL if detailed fine-scale knowledge of the CT distribution and physical heterogeneity is incorporated into the model. However, CT removal could also be fit by a first-order mass transfer analytical model, potentially leading to an erroneous conclusion that the long-term tailing in the experiment was kinetically controlled due to rate-limited NAPL evaporation.

The impact of particle shape on the angle of internal friction and the implications for sediment dynamics at a steep, mixed sand-gravel beach

NASA Astrophysics Data System (ADS)

Stark, N.; Hay, A. E.; Cheel, R.; Lake, C. B.

2014-08-01

The impact of particle shape on the angle of internal friction, and the resulting impact on beach sediment dynamics, is still poorly understood. In areas characterized by sediments of specific shape, particularly non-rounded particles, this can lead to large departures from the expected sediment dynamics. The steep slope (1 : 10) of the mixed sand-gravel beach at Advocate Harbour is stable in large-scale morphology over decades, despite a high tidal range of 10 m or more, and intense shore-break action during storms. The Advocate sand (d < 2 mm) was found to have an elliptic, plate-like shape (Corey Shape Index, CSI ≈ 0.2-0.6). High angles of internal friction of this material were determined using direct shear, ranging from φ ≈ 41 to 49°, while the round to angular gravel was characterized as φ = 33°. The addition of 25% of the elliptic plate-like sand-sized material to the gravel led to an immediate increase in friction angle to φ = 38°. Furthermore, re-organization of the particles occurred during shearing, characterized by a short phase of settling and compaction, followed by a pronounced strong dilatory behavior and an accompanying strong increase of resistance to shear and, thus, shear stress. Long-term shearing (24 h) using a ring shear apparatus led to destruction of the particles without re-compaction. Finally, submerged particle mobilization was simulated using a tilted tray submerged in a water-filled tank. Despite a smooth tray surface, particle motion was not initiated until reaching tray tilt angles of 31° and more, being ≥7° steeper than for motion initiation of the gravel mixtures. In conclusion, geotechnical laboratory experiments quantified the important impact of the elliptic, plate-like shape of Advocate Beach sand on the angles of internal friction of both pure sand and sand-gravel mixtures. The resulting effect on initiation of particle motion was confirmed in tilting tray experiments. This makes it a vivid example of how particle shape can contribute to the stabilization of the beach face.

Cold Regions Test of Tracked and Wheeled Vehicles

DTIC Science & Technology

2015-12-11

with CTIS setting in the Highway setting and Mud, Sand and Snow setting. (7) Conduct the trials a minimum of three times at each speed as stated in...lock brake system. Record the stopping distance data and record any slew from the centerline. Document if the vehicle experiences engine stall ...while operating in snow. The TOP includes guidance for snow as well as mud, sand , swamps, and wet clay. Most conventional wheeled vehicles cannot

Acoustic Scattering from Sand Dollars (Dendraster excentricus): Modeling as High Aspect Ratio Oblate Objects and Comparison to Experiment

DTIC Science & Technology

2008-09-01

results. In Stanton and Chu (2004), forward scattering and backscattering from a sand dollar test, a bivalve shell , and a machined aluminum disk of...Oceanographic Institution Abstract Benthic shells can contribute greatly to the scattering variability of the ocean bottom, particularly at low...grazing angles. Among the effects of shell aggregates are increased scattering strength and potential subcritical angle penetration of the seafloor

Interaction between carboxyl-functionalized carbon black nanoparticles and porous media

NASA Astrophysics Data System (ADS)

Kim, Song-Bae; Kang, Jin-Kyu; Yi, In-Geol

2015-04-01

Carbon nanomaterials, such as carbon nanotubes, fullerene, and graphene, have received considerable attention due to their unique physical and chemical characteristics, leading to mass production and widespread application in industrial, commercial, and environmental fields. During their life cycle from production to disposal, however, carbon nanomaterials are inevitably released into water and soil environments, which have resulted in concern about their health and environmental impacts. Carbon black is a nano-sized amorphous carbon powder that typically contains 90-99% elemental carbon. It can be produced from incomplete combustion of hydrocarbons in petroleum and coal. Carbon black is widely used in chemical and industrial products or applications such as ink pigments, coating plastics, the rubber industry, and composite reinforcements. Even though carbon black is strongly hydrophobic and tends to aggregate in water, it can be dispersed in aqueous media through surface functionalization or surfactant use. The aim of this study was therefore to investigate the transport behavior of carboxyl-functionalized carbon black nanoparticles (CBNPs) in porous media. Column experiments were performed for potassium chloride (KCl), a conservative tracer, and CBNPs under saturated flow conditions. Column experiments was conducted in duplicate using quartz sand, iron oxide-coated sand (IOCS), and aluminum oxide-coated sand (AOCS) to examine the effect of metal (Fe, Al) oxide presence on the transport of CBNPs. Breakthrough curves (BTCs) of CBNPs and chloride were obtained by monitoring effluent, and then mass recovery was quantified from these curves. Additionally, interaction energy profiles for CBNP-porous media were calculated using DLVO theory for sphere-plate geometry. The BTCs of chloride had relative peak concentrations ranging from 0.895 to 0.990. Transport parameters (pore-water velocity v, hydrodynamic dispersion coefficient D) obtained by the model fit from the tracer BTCs were 0.274±0.007 cm min-1 and 0.102±0.025 cm2 min-1, respectively. Mass recoveries of chloride were in the range of 94.7 to 101.9%, indicating that chloride behaved as a conservative tracer and that the column experiments were successful. The BTCs of CBNPs had different relative peak concentrations depending on the porous media used in the experiments. In quartz sand, the relative peak concentration was 0.768±0.005. The mass recovery of CBNPs in quartz sand was 83.1±2.7%, whereas no breakthrough of CBNPs (mass recovery = 0 %) was observed in IOCS or AOCS at the same flow rate, indicating that all CBNPs were retained in the IOCS and AOCS columns under the experimental conditions. These results indicate that metal (Fe, Al) oxides can play a significant role in the attachment of CBNPs to porous media. For the given solution conditions, both CBNPs and quartz sand were negatively charged with zeta potentials of -31.8±0.1 and -39.0±0.6 mV, respectively. Therefore, the electrostatic interactions between CBNPs and quartz sand were repulsive. Meanwhile, both IOCS and ACOS were positively charged with zeta potentials of 10.1±1.3 and 39.9±1.9 mV, respectively, such that the interaction between CBNPs and metal oxide-coated sands was electrostatically attractive, resulting in enhancement of CBNP attachment to the coated sands. Interaction energy profiles for CBNP-porous media were calculated using DLVO theory for sphere-plate geometry. Interaction energy profiles demonstrated that the interaction energy for CBNP-quartz sand was repulsive with a primary maximum (energy barrier) of 63.2 KBT, whereas the interaction energies for CBNP-IOCS and CBNP-AOCS were attractive with no energy barriers. Acknowledgement This research was supported by the National Institute of Environmental Research, Korea Ministry of Environment, in 2014.

A Randomized Controlled Trial Comparing Trainee-Directed Virtual Reality Simulation Training and Box Trainer on the Acquisition of Laparoscopic Suturing Skills.

PubMed

Ko, Jennifer K Y; Cheung, Vincent Y T; Pun, Ting Chung; Tung, Wai Kit

2018-03-01

To compare the proficiency of novices in acquiring laparoscopic suturing skills following training in a virtual reality simulator or box trainer compared to no training. This was a RCT in a university-affiliated teaching hospital recruiting participants who had no laparoscopic suturing experience to have suturing skill training in the virtual reality simulator, box trainer, or no training as control. Trainees were allowed to terminate training when they perceived competence in the procedure. Suturing skills were tested in the box trainer and scored using a modified Global Operative Assessment of Laparoscopic Skills questionnaire by their own self-evaluation and two experienced gynaecological laparoscopists. Of the 36 participants recruited, 27 (75%) had no laparoscopic experience. Participants with no laparoscopic experience took longer to complete training than those with experience (median 90 minutes [interquartile range (IQR) 80-115] vs. 55 min [IQR 40-65], respectively; P = 0.044). There were no differences in successful completion of the task (7/12 [58.3%], 10/12 [83.3%], 7/12 [58.3%]; P = 0.325), median suturing time in seconds (628 [IQR 460-835], 611 [IQR 434-691], 609 [IQR 540-837]; P = 0.702), mean subjective (mean ± SD 9.8 ± 1.8, 10.4 ± 2.8, 9.3 ± 2.4; P = 0.710), and objective (7.2 ± 1.8, 8.2 ± 2.1, 7.6 ± 1.7; P = 0.426) modified Global Operative Assessment of Laparoscopic Skills score in the simulator, pelvic trainer, and control groups, respectively. The intraclass correlation coefficient of the two reviewers was 0.422 (95% CI 0.159-0.717). Trainees were unable to accurately assess themselves as to skill level in laparoscopic suturing. A longer training time is required for novices to master laparoscopic suturing using a simulator or box trainer. Copyright © 2018 Society of Obstetricians and Gynaecologists of Canada. Published by Elsevier Inc. All rights reserved.

Skylab

NASA Image and Video Library

1972-08-21

Lexington, Massachusetts high school student, Judith Miles, discusses her proposed Skylab experiment with Keith Demorest (right) and Henry Floyd, both of Marshall Space Flight Center (MSFC). In her experiment, called the “Web Formation in Zero Gravity”, called for spiders to be released into a box and their actions recorded to determine how well they adapt to the absence of gravity. Spiders are known to adapt quickly to other changes in the environment but nothing was known of their ability to adapt to weightlessness. At the same time spiders were weaving webs in Earth orbit, similar spiders were spinning webs in identical boxes on Earth under full gravity conditions. Miles was among the 25 winners of a contest in which some 3,500 high school students proposed experiments for the following year’s Skylab Mission. Of the 25 students, 6 did not see their experiments conducted on Skylab because the experiments were not compatible with Skylab hardware and timelines. Of the 19 remaining, 11 experiments required the manufacture of equipment.

WEB - A Wireless Experiment Box for the Dextre Pointing Package ELC Payload

NASA Technical Reports Server (NTRS)

Bleier, Leor Z.; Marrero-Fontanez, Victor J.; Sparacino, Pietro A.; Moreau, Michael C.; Mitchell, Jason William

2012-01-01

The Wireless Experiment Box (WEB) was proposed to work with the International Space Station (ISS) External Wireless Communication (EWC) system to support high-definition video from the Dextre Pointing Package (DPP). DPP/WEB was a NASA GSFC proposed ExPRESS Logistics Carrier (ELC) payload designed to flight test an integrated suite of Autonomous Rendezvous and Docking (AR&D) technologies to enable a wide spectrum of future missions across NASA and other US Government agencies. The ISS EWC uses COTS Wireless Access Points (WAPs) to provide high-rate bi-directional communications to ISS. In this paper, we discuss WEB s packaging, operation, antenna development, and performance testing.

Web: A Wireless Experiment Box for the Dextre Pointing Package ELC Payload

NASA Technical Reports Server (NTRS)

Bleier, Leor Z.; Marrero-Fontanez, Victor J.; Sparacino, Pietro A.; Moreau, Michael C.; Mitchell, Jason W.

2012-01-01

The Wireless Experiment Box (WEB) was proposed to work with the International Space Station (ISS) External Wireless Communication (EWC) system to support high-definition video from the Dextre Pointing Package (DPP). DPP/WEB was a NASA GSFC proposed ExPRESS Logistics Carrier (ELC) payload designed to flight test an integrated suite of Autonomous Rendezvous and Docking (AR&D) technologies to enable a wide spectrum of future missions across NASA and other US Government agencies. The ISS EWC uses COTS Wireless Access Points (WAPs) to provide high-rate bi-directional communications to ISS. In this paper, we discuss WEB s packaging, operation, antenna development, and performance testing.

Thermal and Mechanical Testing of Neoprene Gloves Used in a Space Shuttle Microgravity Glove Box Experiment

NASA Technical Reports Server (NTRS)

Wingard, Charles Doug; Munafo, Paul M. (Technical Monitor)

2001-01-01

Neoprene gloves are used in a Space Shuttle Microgravity Glove Box (MGBX) experiment. In 1999, significant corrosion was observed in the work area and on the outer surface of the left glove ring. Analysis of the corrosion products showed that they contained chlorine. The Neoprene gloves used in this glove box were obtained in 1995, with a recommended shelf life of 3 years. After storage of these gloves in a cabinet drawer until 1999, significant signs of corrosion were also observed in the drawer. Mechanical and thermal properties were determined on samples cut from the finger and sleeve areas of the "good" and "bad" gloves. This data showed significant aging of the left-hand glove, particularly in the sleeve area. Thermal analysis data by DSC and TGA was complimentary to tensile data in showing this aging. However, this test data did not pinpoint the cause of the left-hand glove aging, or of the corrosion products.

The SpikerBox: A Low Cost, Open-Source BioAmplifier for Increasing Public Participation in Neuroscience Inquiry

PubMed Central

Marzullo, Timothy C.; Gage, Gregory J.

2012-01-01

Although people are generally interested in how the brain functions, neuroscience education for the public is hampered by a lack of low cost and engaging teaching materials. To address this, we developed an open-source tool, the SpikerBox, which is appropriate for use in middle/high school educational programs and by amateurs. This device can be used in easy experiments in which students insert sewing pins into the leg of a cockroach, or other invertebrate, to amplify and listen to the electrical activity of neurons. With the cockroach leg preparation, students can hear and see (using a smartphone oscilloscope app we have developed) the dramatic changes in activity caused by touching the mechanosensitive barbs. Students can also experiment with other manipulations such as temperature, drugs, and microstimulation that affect the neural activity. We include teaching guides and other resources in the supplemental materials. These hands-on lessons with the SpikerBox have proven to be effective in teaching basic neuroscience. PMID:22470415

Effect of enzymatic orientation through the use of syringaldazine molecules on multiple multi-copper oxidase enzymes.

PubMed

Ulyanova, Yevgenia; Babanova, Sofia; Pinchon, Erica; Matanovic, Ivana; Singhal, Sameer; Atanassov, Plamen

2014-07-14

The effect of proper enzyme orientation at the electrode surface was explored for two multi-copper oxygen reducing enzymes: Bilirubin Oxidase (BOx) and Laccase (Lac). Simultaneous utilization of "tethering" agent (1-pyrenebutanoic acid, succinimidyl ester; PBSE), for stable enzyme immobilization, and syringaldazine (Syr), for enzyme orientation, of both Lac and BOx led to a notable enhancement of the electrode performance. For Lac cathodes tested in solution it was established that PBSE-Lac and PBSE-Syr-Lac modified cathodes demonstrated approximately 6 and 9 times increase in current density, respectively, compared to physically adsorbed and randomly oriented Lac cathodes. Further testing in solution utilizing BOx showed an even higher increase in achievable current densities, thus BOx was chosen for additional testing in air-breathing mode. In subsequent air-breathing experiments the incorporation of PBSE and Syr with BOx resulted in current densities of 0.65 ± 0.1 mA cm(-2); 2.5 times higher when compared to an unmodified BOx cathode. A fully tethered/oriented BOx cathode was combined with a NAD-dependent Glucose Dehydrogenase anode for the fabrication of a complete enzymatic membraneless fuel cell. A maximum power of 1.03 ± 0.06 mW cm(-2) was recorded for the complete fuel cell. The observed significant enhancement in the performance of "oriented" cathodes was a result of proper enzyme orientation, leading to facilitated enzyme/electrode interface interactions.

STEPPED GEAR SYNCHRONIZERS,

DTIC Science & Technology

The book concerns Soviet and foreign experience in the design and use of synchronizers in the step gear boxes of transport vehicles. Side by side...with description of the basic steps in the development of the gear engagement mechanisms and of the design used in synchronizers of domestic and foreign...manufacture, in this work much attention is devoted to the theory of gear engagement in gear boxes equipped with synchronizers , and to figuring out

Aging and involuntary attention capture: electrophysiological evidence for preserved attentional control with advanced age.

PubMed

Lien, Mei-Ching; Gemperle, Alison; Ruthruff, Eric

2011-03-01

The present study examined whether people become more susceptible to capture by salient objects as they age. Participants searched a target display for a letter in a specific color and indicated its identity. In Experiment 1, this target display was preceded by a non-informative cue display containing one target-color box, one ignored-color box, and two white boxes. On half of the trials, this cue display also contained a salient-but-irrelevant abrupt onset. To assess capture by the target-color cue, we used the N2pc component of the event-related potential, thought to reflect attentional allocation to the left or right visual field. The target-color box in the cue display produced a substantial N2pc effect for younger adults and, most importantly, this effect was not diminished by the presence of an abrupt onset. Therefore, the abrupt onset was unable to capture attention away from the target-color cue. Critically, older adults demonstrated the same resistance to capture by the abrupt onset. Experiment 2 extended these findings to irrelevant color singleton cues. Thus, we argue that the ability to attend to relevant stimuli and resist capture by salient-but-irrelevant stimuli is preserved with advancing age. (c) 2011 APA, all rights reserved.

The impact of particle shape on friction angle and resulting critical shear stress: an example from a coarse-grained, steep, megatidal beach

NASA Astrophysics Data System (ADS)

Stark, N.; Hay, A. E.; Cheel, R.; Lake, C. B.

2013-12-01

The impact of particle shape on the friction angle, and the resulting critical shear stress on sediment dynamics, is still poorly understood. In areas characterized by sediments of specific shape, particularly non-rounded particles, this can lead to large departures from the expected sediment dynamics. The steep slope (1:10) of the mixed sand-gravel beach at Advocate Harbour was found stable in large-scale morphology over decades, despite a high tidal range of ten meters or more, and strong shorebreak action during storms. The Advocate sand (d < 2 mm) was found to have an elliptic, plate-like shape. Exceptionally high friction angles of the material were determined using direct shear, ranging from φ ≈ 41-46°, while the round to angular gravel was characterized by φ = 33°. The addition of 25% of the elliptic sand to the gravel led to an immediate increase of the friction angle to φ = 38°. Furthermore, re-organization of the particles occurred during shearing, being characterized by a short phase of settling and compaction, followed by a pronounced strong dilatory behavior and an accompanying strong increase of shear stress. Long-term shearing (24 h) using a ring shear apparatus led to destruction of the particles without re-compaction. Finally, submerged particle mobilization was simulated using a tilted tray in a tank. Despite a smooth tray surface, particle motion was not initiated until reaching tray tilt angles of 31° and more, being 7° steeper than the latest gravel motion initiation. In conclusion, geotechnical laboratory experiments quantified the important impact of the elliptic, plate-like shape of Advocate Beach sand on the friction angles of both pure sand and sand-gravel mixtures. The resulting effect on initiation of particle motion was confirmed in tilting tray experiments. This makes it a vivid example of how particle shape can contribute to the stabilization of the beachface.

Application of wind-profiling radar data to the analysis of dust weather in the Taklimakan Desert.

PubMed

Wang, Minzhong; Wei, Wenshou; Ruan, Zheng; He, Qing; Ge, Runsheng

2013-06-01

The Urumqi Institute of Desert Meteorology of the China Meteorological Administration carried out an atmospheric scientific experiment to detect dust weather using a wind-profiling radar in the hinterland of the Taklimakan Desert in April 2010. Based on the wind-profiling data obtained from this experiment, this paper seeks to (a) analyze the characteristics of the horizontal wind field and vertical velocity of a breaking dust weather in a desert hinterland; (b) calculate and give the radar echo intensity and vertical distribution of a dust storm, blowing sand, and floating dust weather; and (c) discuss the atmosphere dust counts/concentration derived from the wind-profiling radar data. Studies show that: (a) A wind-profiling radar is an upper-air atmospheric remote sensing system that effectively detects and monitors dust. It captures the beginning and ending of a dust weather process as well as monitors the sand and dust being transported in the air in terms of height, thickness, and vertical intensity. (b) The echo intensity of a blowing sand and dust storm weather episode in Taklimakan is about -1~10 dBZ while that of floating dust -1~-15 dBZ, indicating that the dust echo intensity is significantly weaker than that of precipitation but stronger than that of clear air. (c) The vertical shear of horizontal wind and the maintenance of low-level east wind are usually dynamic factors causing a dust weather process in Taklimakan. The moment that the low-level horizontal wind field finds a shear over time, it often coincides with the onset of a sand blowing and dust storm weather process. (d) When a blowing sand or dust storm weather event occurs, the atmospheric vertical velocity tends to be of upward motion. This vertical upward movement of the atmosphere supported with a fast horizontal wind and a dry underlying surface carries dust particles from the ground up to the air to form blown sand or a dust storm.

Oil prospection using the tectonic plate model

NASA Astrophysics Data System (ADS)

Pointu, Agnès

2015-04-01

Tectonic plate models are an intellectual setting to understand why oil deposits are so uncommon and unequally distributed and how models can be used in actual oil and gas prospection. In this case, we use the example of the Ghawar deposit (Saudi Arabia), one of the largest producing well in the world. In the first step, physical properties of rocks composing the oil accumulation are studied by laboratory experiments. Students estimate the porosity of limestone and clay by comparing their mass before and after water impregnation. Results are compared to microscopic observations. Thus, students come to the conclusion that oil accumulations are characterized by superposition of rocks with very different properties: a rich organic source rock (clays of the Hanifa formation), a porous reservoir rock to store the petroleum in (limestones of the Arab formation) and above an impermeable rock with very low porosity (evaporites of the Tithonien). In previous lessons, students have seen that organic matter is usually mineralized by bacteria and that this preservation requires particular conditions. The aim is to explain why biomass production has been so important during the deposit of the clays of the Hanifa formation. Tectonic plate models make it possible to estimate the location of the Arabian Peninsula during Jurassic times (age of Hanifa formation). In order to understand why the paleo-location of the Arabian Peninsula is important to preserve organic matter, students have different documents showing: - That primary production of biomass by phytoplankton is favored by climatic conditions, - That the position of continents determinate the ocean currents and the positions of upwelling zones and zones where organic matter will be able to be preserved, - That north of the peninsula there was a passive margin during Jurassic times. An actual seismic line is studied in order to highlight that this extensive area allowed thick sedimentary deposits to accumulate and that fast sedimentation rate is necessary to bury organic matter and to restrict the mineralization. Consequences of crustal extension are also studied by using an experimental sand box model. The creation of faults is related to the subsidence of the margin. This subsidence allows the crossing of the oil window, leading to pyrolysis of organic matter and its transformation into oil. Afterwards, students compare the structures obtained after extension in their sand box to the actual organization of the Ghawar oil accumulation (seismic line). They can see that faults created by extension forces have not been preserved and can assume that compression forces have caused formation of the traps. An animation of paleo-location of continents during the upper Jurassic helps them to think that compression forces are linked to the closure of the Tethys Sea. A model using gravel and clay is used to show the principle of oil trapping. This way, students understand how the tectonic plate models explain the actual location of oil deposits and then how it can be used to look for new deposits.

Design and Development of Smart Medicine Box

NASA Astrophysics Data System (ADS)

Rosli, Ekbal; Husaini, Yusnira

2018-03-01

The Smart Medicine Box is successfully designed in helping the introvert patients taking their medicine without help of others. This project is to develop a robotic device that can assist patient to take medicine alone by implementing an IOT apps system for controlling the Smart Medicine Box where it will overcome an emotional disturbance experience by the introvert patients. There are four sensors such as PIR, IR, temperature and ultrasonic sensors use for the project. The purpose of PIR sensor is to detect hand movement near the device, while IR sensor is to detect the line follower on the floor. The LM 35 acts as the detection of the temperature inside the box and the ultrasonic acts as the detection of the obstacle in front of the device. The MIT Apps Invention 2 is used to develop an apps and collect the data from sensors through Arduino microcontroller. A proof of concept design has implemented and demonstrated successfully.

Bubble propagation in a pipe filled with sand.

PubMed

Gendron, D; Troadec, H; Måløy, K J; Flekkøy, E G

2001-08-01

Granular flow with strong hydrodynamic interactions has been studied experimentally. Experiments have been carried out to study the movement of a single bubble in an inclined tube filled with glass beads and air. A maximum bubble velocity was found at an inclined angle straight theta(m). The density variations in the sand were measured by capacitance measurements, and a decompactification zone was observed just above the bubble when the inclination angle straight theta was larger than straight theta(m). The length of the decompactification front increased with increasing inclination angle and disappeared for angles smaller than straight theta(m). Both pressure and visualization experiments were carried out and compared with the density measurements.

Portable computing - A fielded interactive scientific application in a small off-the-shelf package

NASA Technical Reports Server (NTRS)

Groleau, Nicolas; Hazelton, Lyman; Frainier, Rich; Compton, Michael; Colombano, Silvano; Szolovits, Peter

1993-01-01

Experience with the design and implementation of a portable computing system for STS crew-conducted science is discussed. Principal-Investigator-in-a-Box (PI) will help the SLS-2 astronauts perform vestibular (human orientation system) experiments in flight. PI is an interactive system that provides data acquisition and analysis, experiment step rescheduling, and various other forms of reasoning to astronaut users. The hardware architecture of PI consists of a computer and an analog interface box. 'Off-the-shelf' equipment is employed in the system wherever possible in an effort to use widely available tools and then to add custom functionality and application codes to them. Other projects which can help prospective teams to learn more about portable computing in space are also discussed.

Root architecture simulation improves the inference from seedling root phenotyping towards mature root systems.

PubMed

Zhao, Jiangsan; Bodner, Gernot; Rewald, Boris; Leitner, Daniel; Nagel, Kerstin A; Nakhforoosh, Alireza

2017-02-01

Root phenotyping provides trait information for plant breeding. A shortcoming of high-throughput root phenotyping is the limitation to seedling plants and failure to make inferences on mature root systems. We suggest root system architecture (RSA) models to predict mature root traits and overcome the inference problem. Sixteen pea genotypes were phenotyped in (i) seedling (Petri dishes) and (ii) mature (sand-filled columns) root phenotyping platforms. The RSA model RootBox was parameterized with seedling traits to simulate the fully developed root systems. Measured and modelled root length, first-order lateral number, and root distribution were compared to determine key traits for model-based prediction. No direct relationship in root traits (tap, lateral length, interbranch distance) was evident between phenotyping systems. RootBox significantly improved the inference over phenotyping platforms. Seedling plant tap and lateral root elongation rates and interbranch distance were sufficient model parameters to predict genotype ranking in total root length with an RSpearman of 0.83. Parameterization including uneven lateral spacing via a scaling function substantially improved the prediction of architectures underlying the differently sized root systems. We conclude that RSA models can solve the inference problem of seedling root phenotyping. RSA models should be included in the phenotyping pipeline to provide reliable information on mature root systems to breeding research. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Floor of Juventae Chasma

NASA Technical Reports Server (NTRS)

2002-01-01

(Released 30 May 2002) Juventae Chasma is an enormous box canyon (250 km X 100 km) which opens to the north and forms the outflow channel Maja Vallis. Most Martian outflow channels such as Maja, Kasei, and Ares Valles begin at point sources such as box canyons and chaotic terrain and then flow unconfined into a basin region. This image captures a portion of the western floor of Juventae Chasma and shows a wide variety of landforms. Conical hills, mesas, buttes and plateaus of layered material dominate this scene and seem to be 'swimming' in vast sand sheets. The conical hills have a spur and gully topography associated with them while the flat topped buttes and mesas do not. This may be indicative of different materials that compose each of these landforms or it could be that the flat-topped layer has been completely eroded off of the conical hills thereby exposing a different rock type. Both the conical hills and flat-topped buttes and mesas have extensive scree slopes (heaps of eroded rock and debris). Ripples, which are inferred to be dunes, can also be seen amongst the hills. No impact craters can be seen in this image, indicating that the erosion and transport of material down the canyon wall and across the floor is occurring at a relatively rapid rate, so that any craters that form are rapidly buried or eroded.

The effects of sodium azide on seed germination and seedling growth of chili pepper (Capsicum annum L. cv. Landung)

NASA Astrophysics Data System (ADS)

Yafizham; Herwibawa, B.

2018-01-01

This study was aimed to determine the effects of sodium azide on the performance of chili pepper. Dry seeds from pure lines of chili pepper cv. Landung were used in this experiment. Each set containing 50 seeds was placed in nylon fishner bags, washed in flowing water and soaked in distilled water for four hours. After soaking, four sets of seeds were dabbed dry with tissue paper and were treated for two hours at 30 0C in appropriate solution of 0, 0.10, 0.20, 0.40, 0.80, 1.60 mM sodium azide with phosphate buffer at pH 3. After treatment, the seeds were germinated in plastic boxes containing sterilized sand and kept under laboratory condition by supplied with water everyday. The seeds for M1 germination percentage, seedling height, plant height and number of leaves were recorded 30 days and 60 days after treatment, respectively. Seeds which radicle emerged were considered germinated, the seedling and plant height were measured from the tip of primary root to the base of the first leaf pair, and the number of leaves were counted for only fully expanded leaves. A completely randomized block design in four replicates was used throughout the experiment. Data obtained were analysed for range, mean, standard of deviation, and percent of control using Microsoft Office Excel 2007 software. It was concluded that different doses of sodium azide influenced the performances of chili pepper cv. Landung. Very low doses of sodium azide (0-1.60 mM) might be used to study the improvement of chili pepper diversity.

Surgical resident evaluations of portable laparoscopic box trainers incorporated into a simulation-based minimally invasive surgery curriculum.

PubMed

Zapf, Matthew A C; Ujiki, Michael B

2015-02-01

Box trainers have been shown to be an effective tool for teaching laparoscopic skills; however, residents are challenged to find practice time. Portable trainers theoretically allow for extended hands on practice out of the hospital. We aimed to report resident experience with laparoscopic home box trainers. Over 2 years, all residents rotating through a minimally invasive service were given a portable trainer and access to a surgical simulation lab for practice. Each trainer contained a collapsible frame, a webcam with USB port, trocars, and laparoscopic instruments (needle driver, shears, Maryland and straight dissecting graspers) as well as Fundamentals of Laparoscopic Surgery skills testing materials. Residents were asked to log hours, usages, and their experience anonymously. Twenty-three residents received a portable trainer. Fifty percent of the participants found the trainer useful or very useful, 25% said it was not useful, and 25% did not access the trainer. Those that used the trainer during their rotation did so 3.1 ± 3.0 times for 2.9 ± 3.0 hours/week. After completing their rotation, 5 of 12 residents used their trainer for an average of 10.2 ± 9.4 hours. Forty-two percent of the responders liked the accessibility of the home box trainers, while 25% criticized the camera-computer interface. Portable box trainers are useful and can effectively supplement a laboratory-based surgical simulation curriculum; however, personal possession of a portable simulator does not result in voluntarily long-term practice. © The Author(s) 2014.

Recolonization of bat roost by bat bugs (Cimex pipistrelli): could parasite load be a cause of bat roost switching?

PubMed

Bartonička, Tomáš; Růžičková, Lucie

2013-04-01

Roost ectoparasites are believed to have a negative impact on fitness of their hosts as birds or mammals. Previous studies were mostly focussed on the synchronization between reproduction cycles of ectoparasites and hosts living in infested roosts. However, to date, it has not been examined how fast ectoparasites colonize new, non-infested roosts and thus increasing the impact on the local populations of hosts. The parasite-host model was studied, including bat bugs Cimex pipistrelli and soprano pipistrelles Pipistrellus pygmaeus, where bat behaviour was observed which tended to reduce the parasite load in bat roosts. We investigated (1) whether bats change their roosting behaviour when we discontinued synchronization of their reproduction and the life cycle of the bat bugs and (2) how fast and which stages of bat bugs reoccupy cleaned roosts. In a 3-year field experiment, we removed all bat bugs from six bat boxes in each spring. Pipistrelles bred young in all non-infested boxes during these 3 years. In addition, 8 years of regular observations before this experiment indicate that bats avoided breeding in the same bat boxes at all. Bat bugs were found again in clean boxes in mid-May. However, their densities did not maximise before the beginning of June, before parturition. A re-appearance of bugs was observed after 21-56 days after the first bat visit. Adult bugs, mainly females, colonised cleaned boxes first though at the same time there were a lot of younger and smaller instars in non-manipulated roosts in the vicinity.

Measured and Predicted Burial of Cylinders During the Indian Rocks Beach Experiment

DTIC Science & Technology

2007-01-01

in shallow water (15-16 m) with fine-sand (133-/xm) and coarse-sand (566-/xm) sediments off Indian Rocks Beach (IRB), FL. Scour pits developed...eter) relative to the sediment- water interface, but only 20%-50% relative to surface area covered. The difference was caused by the lack of...sensors intended to indicate the surface area of the cylinder covered by sediment or water (i.e., percent surface area exposed during burial) and

Strength and microstructure characteristics of the recycled rubber tire-sand mixtures as lightweight backfill.

PubMed

Zhang, Tao; Cai, Guojun; Duan, Weihong

2018-02-01

The disposal of scrap rubber tires has induced critical environmental issue worldwide due to the rapid increase in the number of vehicles. Recycled scrap tires as a construction material in civil engineering have significant environmental benefits from a waste management perspective. A systematic study that deals with strength and microstructure characteristics of the rubber-sand mixtures is initiated, and mechanical response of the mixtures is discussed in this investigation. Experiments were conducted to evaluate the effects of rubber fraction on the basic properties including mass density (ρ), stress-strain characteristics, shear strength, and unconfined compression strength (q u ) of the rubber-sand mixtures. Additionally, scanning electron microscopy (SEM) was carried out to reveal the microstructure characteristics of the mixtures with various rubber fractions. A discussion on the micromechanics of the mixtures also was conducted. This study demonstrates that the ρ, friction angle, and q u decrease linearly with an increase in rubber fraction, whereas shear strain at peak increases. The stress-strain characteristics of the rubber-sand mixtures shift from brittle to ductile as the rubber fraction increase. These changes are attributed to remarkably lower stiffness and higher compressibility of the rubber particle compared with those of the conventional mineral aggregates. With an increase in the rubber fraction, the mechanical response of rubber-sand mixtures exhibits two types: sand-like material and rubber-like material. Rubber particle possesses the capacity to prevent the contacted sand particles from sliding at lower rubber fraction, whereas it transmits the applied loadings as the rubber fraction increased. This outcome reinforces the practicability of using recycled rubber tire-sand mixtures as a lightweight backfill in subbase/base applications.

Do peat amendments to oil sands wet sediments affect Carex aquatilis biomass for reclamation success?

PubMed

Roy, Marie-Claude; Mollard, Federico P O; Foote, A Lee

2014-06-15

The oil sands industries of Alberta (Canada) have reclamation objectives to return the mined landscape to equivalent pre-disturbance land capability. Industrial operators are charged with reclaiming a vast landscape of newly exposed sediments on saline-sodic marine-shales sediments. Incorporated in these sediments are by-products resulting from bitumen extraction (consolidated tailings (CT), tailings-sand (TS), and oil sands processed water (OSPW)). A sedge community dominated by Carex aquatilis was identified as a desirable and representative late-succession community for wet-meadow zones of oil sands-created marshes. However, the physical and chemical conditions, including high salinity and low nutrient content of CT and TS sediments suppress plant growth and performance. We experimentally tested the response of C. aquatilis to amendments with peat-mineral-mix (PM) on oil sand sediments (CT and TS). In a two factorial design experiment, we also tested the effects of OSPW on C. aquatilis. We assessed survival, below- and aboveground biomass, and physiology (chlorophyll a fluorescence). We demonstrated that PM amendments to oil sands sediments significantly increased C. aquatilis survival as well as below and aboveground biomass. The use of OSPW significantly reduced C. aquatilis belowground biomass and affected its physiological performance. Due to its tolerance and performance, we verified that C. aquatilis was a good candidate for use in reclaiming the wet-meadow zones of oil sands-created marshes. Ultimately, amending CT and TS with PM expedited the reclamation of the wetland to a C. aquatilis-community which was similar in gross structure to undisturbed wetlands of the region. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reduced transport potential of a palladium-doped zero valent iron nanoparticle in a water saturated loamy sand.

PubMed

Basnet, Mohan; Di Tommaso, Caroline; Ghoshal, Subhasis; Tufenkji, Nathalie

2015-01-01

Direct in situ injection of palladium-doped nanosized zero valent iron (Pd-NZVI) particles can contribute to remediation of various environmental contaminants. A major challenge encountered is rapid aggregation of Pd-NZVI and hence very limited mobility. To reduce aggregation and concurrently improve particle mobility, the surface of bare Pd-NZVI can be modified with stabilizing surface modifiers. Selected surface-modified Pd-NZVI has shown dramatically improved stability and transport. However, little is known regarding the effects of aquifer grain geochemical heterogeneity on the transport and deposition behavior of surface-modified Pd-NZVI. Herein, the mobility of surface stabilized Pd-NZVI in two granular matrices representative of model ground water environments (quartz sand and loamy sand) was assessed over a wide range of environmentally relevant ionic strengths (IS). Carboxymethyl cellulose (CMC), soybean flour and rhamnolipid biosurfactant were used as Pd-NZVI surface modifiers. Our results show that, both in quartz sand and loamy sand, an increase in solution IS results in reduced Pd-NZVI transport. Moreover, at a given water chemistry, Pd-NZVI transport is notably attenuated in loamy sand implying that geochemical heterogeneity associated with loamy sand is a key factor influencing Pd-NZVI transport potential. Experiments conducted at a higher Pd-NZVI particle concentration, to be more representative of field conditions, show that rhamnolipid and CMC are effective stabilizing agents even when 1 g/L Pd-NZVI is injected into quartz sand. Overall, this study emphasizes the extent to which variation in groundwater chemistry, coupled with changes in aquifer geochemistry, could dramatically alter the transport potential of Pd-NZVI in the subsurface environment.

Multibeam observations of mine burial near Clearwater, FL, including comparisons to predictions of wave-induced burial

USGS Publications Warehouse

Wolfson, M.L.; Naar, D.F.; Howd, P.A.; Locker, S.D.; Donahue, B.T.; Friedrichs, Carl T.; Trembanis, A.C.; Richardson, M.D.; Wever, T.F.

2007-01-01

A Kongsberg Simrad EM 3000 multibeam sonar (Kongsberg Simrad, Kongsberg, Norway) was used to conduct a set of six repeat high-resolution bathymetric surveys west of Indian Rocks Beach (IRB), just to the south of Clearwater, FL, between January and March 2003, to observe in situ scour and burial of instrumented inert mines and mine-like cylinders. Three closely located study sites were chosen: two fine-sand sites, a shallow one located in ??? 13 m of water depth and a deep site located in ???14 m of water depth; and a coarse-sand site in ???13 m. Results from these surveys indicate that mines deployed in fine sand are nearly buried within two months of deployment (i.e., they sunk 74.5% or more below the ambient seafloor depth). Mines deployed in coarse sand showed a lesser amount of scour, burying until they present roughly the same hydrodynamic roughness as the surrounding rippled bedforms. These data were also used to test the validity of the Virginia Institute of Marine Science (VIMS, Gloucester Point, VA) 2-D burial model. The model worked well in areas of fine sand, sufficiently predicting burial over the course of the experiment. In the area of coarse sand, the model greatly overpredicted the amount of burial. This is believed to be due to the presence of rippled bedforms around the mines, which affect local bottom morphodynamics and are not accounted for in the model, an issue currently being addressed by the modelers. This paper focuses specifically on two instrumented mines: an acoustic mine located in fine sand and an optical instrumented mine located in coarse sand. ?? 2007 IEEE.

Heated fiber optic distributed temperature sensing: a tool for measuring soil water content

NASA Astrophysics Data System (ADS)

Rodriguez-Sinobas, Leonor; Zubelzu, Sergio; Sánchez-Calvo, Raúl; Horcajo, Daniel

2016-04-01

The use of Distributed Fiber Optic Temperature Measurement (DFOT) method for estimating temperature variation along a cable of fiber optic has been assessed in multiple environmental applications. Recently, the application of DFOT combined with an active heating pulses technique has been reported as a sensor to estimate soil moisture. This method applies a known amount of heat to the soil and monitors the temperature evolution, which mainly depends on the soil moisture content . This study presents the application of the Active Heated DFOT method to determine the soil water retention curve under experimental conditions. The experiment was conducted in a rectangular methacrylate box of 2.5 m x 0.25 m x 0.25 m which was introduced in a larger box 2.8 m x 0.3 m x 0.3 m of the same material. The inner box was filled with a sandy loamy soil collected from the nearest garden and dried under ambient temperature for 30 days. Care was taking to fill up the box maintaining the soil bulk density determined "in-situ". The cable was deployed along the box at 10 cm depth. At the beginning of the experiment, the box was saturated bottom-up, by filling the outer box with water, and then it kept dried for two months. The circulation of heated air at the bottom box accelerated the drying process. In addition, fast growing turf was also sowed to dry it fast. The DTS unit was a SILIXA ULTIMA SR (Silixa Ltd, UK) and has spatial and temporal resolution of 0.29 m and 5 s, respectively. In this study, heat pulses of 7 W/m for 2 1/2 min were applied uniformly along the fiber optic cable and the thermal response on an adjacent cable was monitored in different soil water status. Then, the heating and drying phase integer (called Tcum) was determined following the approach of Sayde et al., (2010). For each water status,  was measured by the gravimetric method in several soil samples collected in three box locations at the same depth that the fiber optic cable and after each heat pulse. Finally, the soil water retention curve was estimated by fitting pairs of Tcum- values. Results showed the feasibility of heated fiber optics with distributed temperature sensing to estimate soil water content, and suggest its potential for its application under field conditions

Transport of sulfacetamide and levofloxacin in granular porous media under various conditions: Experimental observations and model simulations.

PubMed

Dong, Shunan; Gao, Bin; Sun, Yuanyuan; Shi, Xiaoqing; Xu, Hongxia; Wu, Jianfeng; Wu, Jichun

2016-12-15

Understanding the fate and transport of antibiotics in porous media can help reduce their contamination risks to soil and groundwater systems. In this work, batch and column experiments were conducted to determine the interactions between two representative antibiotics, sulfacetamide (SA) and levofloxacin (LEV), and sand porous media under various solution pH, humic acid (HA) concentration, grain size, and moisture content conditions. Batch sorption experimental results indicated that the sand had relatively strong bonding affinity to LEV, but little sorption of SA under different pH, HA concentration, grain size conditions. Results from the packed sand column experiments showed that SA had extremely high mobility in the porous media for all combinations of pH, HA concentration, grain size, and moisture content. The mass recovery of SA was higher than 98.5% in all the columns with the exception of the one packed with fine sand (97.2%). The retention of LEV in the columns was much higher and the recovery rates ranged from 0% to 71.1%. Decreases in solution pH, HA concentration, grain size, or moisture content reduced the mobility of LEV in the columns under the tested conditions. These results indicated that type of antibiotics and environmental conditions also played an important role in controlling their fate and transport in porous media. Mathematical models were applied to simulate and interpret experimental data, and model simulations described the interactions between the two antibiotics and sand porous media very well. Findings from this study elucidated the key factors and processes controlling the fate of SA and LEV in porous media, which can inform the prediction and assessment of the environmental risks of antibiotics. Copyright © 2016 Elsevier B.V. All rights reserved.

Phenomenological Description of Acoustic Emission Processes Occurring During High-Pressure Sand Compaction

NASA Astrophysics Data System (ADS)

Delgado-Martín, Jordi; Muñoz-Ibáñez, Andrea; Grande-García, Elisa; Rodríguez-Cedrún, Borja

2016-04-01

Compaction, pore collapse and grain crushing have a significant impact over the hydrodynamic properties of sand formations. The assessment of the crushing stress threshold constitutes valuable information in order to assess the behavior of these formations provided that it can be conveniently identified. Because of the inherent complexities of the direct observation of sand crushing, different authors have developed several indirect methods, being acoustic emission a promising one. However, previous researches have evidenced that there are different processes triggering acoustic emissions which need to be carefully accounted. Worth mentioning among them are grain bearing, grain to container friction, intergranular friction and crushing. The work presented here addresses this purpose. A broadband acoustic emission sensor (PA MicroHF200) connected to a high-speed data acquisition system and control software (AeWIN for PCI1 2.10) has been attached to a steel ram and used to monitor the different processes occurring during the oedometric compaction of uniform quartz sand up to an axial load of about 110 MPa and constant temperature. Load was stepwise applied using a servocontrolled hydraulic press acting at a constant load rate. Axial strain was simultaneously measured with the aid of a LDT device. Counts, energy, event duration, rise time and amplitude were recorded along each experiment and after completion selected waveforms were transformed from the time to the frequency domain via FFT transform. Additional simplified tests were performed in order to isolate the frequency characteristics of the dominant processes occurring during sand compaction. Our results show that, from simple tests, it is possible to determine process-dependent frequency components. When considering more complex experiments, many of the studied processes overlap but it is still possible to identify when a particular one dominates as well as the likely onset of crushing.

Laboratory observations of artificial sand and oil agglomerates

USGS Publications Warehouse

Jenkins, Robert L.; Dalyander, P. Soupy; Penko, Allison; Long, Joseph W.

2018-04-27

Sand and oil agglomerates (SOAs) form when weathered oil reaches the surf zone and combines with suspended sediments. The presence of large SOAs in the form of thick mats (up to 10 centimeters [cm] in height and up to 10 square meters [m2] in area) and smaller SOAs, sometimes referred to as surface residual balls (SRBs), may lead to the re-oiling of beaches previously affected by an oil spill. A limited number of numerical modeling and field studies exist on the transport and dynamics of centimeter-scale SOAs and their interaction with the sea floor. Numerical models used to study SOAs have relied on shear-stress formulations to predict incipient motion. However, uncertainty exists as to the accuracy of applying these formulations, originally developed for sand grains in a uniformly sorted sediment bed, to larger, nonspherical SOAs. In the current effort, artificial sand and oil agglomerates (aSOAs) created with the size, density, and shape characteristics of SOAs were studied in a small-oscillatory flow tunnel. These experiments expanded the available data on SOA motion and interaction with the sea floor and were used to examine the applicability of shear-stress formulations to predict SOA mobility. Data collected during these two sets of experiments, including photographs, video, and flow velocity, are presented in this report, along with an analysis of shear-stress-based formulations for incipient motion. The results showed that shear-stress thresholds for typical quartz sand predicted the incipient motion of aSOAs with 0.5–1.0-cm diameters, but were inaccurate for aSOAs with larger diameters (>2.5 cm). This finding implies that modified parameterizations of incipient motion may be necessary under certain combinations of aSOA characteristics and environmental conditions.

The heart rate response to nintendo wii boxing in young adults.

PubMed

Bosch, Pamela R; Poloni, Joseph; Thornton, Andrew; Lynskey, James V

2012-06-01

To determine if 30 minutes of Nintendo Wii Sports boxing provides cardiorespiratory benefits and contributes to the daily exercise recommendations for healthy young adults. Twenty healthy 23- to 27-year-olds participated in two sessions to measure maximum heart rate (HR(max)) via a treadmill test and heart rate (HR) response to 30 minutes of Wii Sports boxing. Heart rate in beats per minute (bpm) was measured continuously, and exercise intensity during each minute of play was stratified as a percentage of HR(max). Mixed designs analysis of variance (ANOVA) and Pearson product moment correlations were used to analyze the data. Mean (SD) HR response to boxing was 143 (15) bpm or 77.5% (10.0%) of HR(max). The mean HR response for experienced participants was significantly lower than inexperienced participants, P = .007. The ANOVA revealed a significant interaction between experience and time spent at various intensities, P = .009. Experienced participants spent more time in light to vigorous intensities, inexperienced participants in moderate to very hard intensities. Fitness was not correlated with mean HR response to boxing, P = .49. Thirty minutes of Nintendo Wii Sports boxing provides a moderate to vigorous aerobic response in healthy young adults and can contribute to daily recommendations for physical activity.

The Heart Rate Response to Nintendo Wii Boxing in Young Adults

PubMed Central

Bosch, Pamela R.; Poloni, Joseph; Thornton, Andrew; Lynskey, James V.

2012-01-01

Purpose To determine if 30 minutes of Nintendo Wii Sports boxing provides cardiorespiratory benefits and contributes to the daily exercise recommendations for healthy young adults. Methods Twenty healthy 23- to 27-year-olds participated in two sessions to measure maximum heart rate (HRmax) via a treadmill test and heart rate (HR) response to 30 minutes of Wii Sports boxing. Heart rate in beats per minute (bpm) was measured continuously, and exercise intensity during each minute of play was stratified as a percentage of HRmax. Mixed designs analysis of variance (ANOVA) and Pearson product moment correlations were used to analyze the data. Results Mean (SD) HR response to boxing was 143 (15) bpm or 77.5% (10.0%) of HRmax. The mean HR response for experienced participants was significantly lower than inexperienced participants, P = .007. The ANOVA revealed a significant interaction between experience and time spent at various intensities, P = .009. Experienced participants spent more time in light to vigorous intensities, inexperienced participants in moderate to very hard intensities. Fitness was not correlated with mean HR response to boxing, P = .49. Conclusion Thirty minutes of Nintendo Wii Sports boxing provides a moderate to vigorous aerobic response in healthy young adults and can contribute to daily recommendations for physical activity. PMID:22833705

SimpleBox 4.0: Improving the model while keeping it simple….

PubMed

Hollander, Anne; Schoorl, Marian; van de Meent, Dik

2016-04-01

Chemical behavior in the environment is often modeled with multimedia fate models. SimpleBox is one often-used multimedia fate model, firstly developed in 1986. Since then, two updated versions were published. Based on recent scientific developments and experience with SimpleBox 3.0, a new version of SimpleBox was developed and is made public here: SimpleBox 4.0. In this new model, eight major changes were implemented: removal of the local scale and vegetation compartments, addition of lake compartments and deep ocean compartments (including the thermohaline circulation), implementation of intermittent rain instead of drizzle and of depth dependent soil concentrations, adjustment of the partitioning behavior for organic acids and bases as well as of the value for enthalpy of vaporization. In this paper, the effects of the model changes in SimpleBox 4.0 on the predicted steady-state concentrations of chemical substances were explored for different substance groups (neutral organic substances, acids, bases, metals) in a standard emission scenario. In general, the largest differences between the predicted concentrations in the new and the old model are caused by the implementation of layered ocean compartments. Undesirable high model complexity caused by vegetation compartments and a local scale were removed to enlarge the simplicity and user friendliness of the model. Copyright © 2016 Elsevier Ltd. All rights reserved.

Zonal Flows and Long-lived Axisymmetric Pressure Bumps in Magnetorotational Turbulence

NASA Astrophysics Data System (ADS)

Johansen, A.; Youdin, A.; Klahr, H.

2009-06-01

We study the behavior of magnetorotational turbulence in shearing box simulations with a radial and azimuthal extent up to 10 scale heights. Maxwell and Reynolds stresses are found to increase by more than a factor of 2 when increasing the box size beyond two scale heights in the radial direction. Further increase of the box size has little or no effect on the statistical properties of the turbulence. An inverse cascade excites magnetic field structures at the largest scales of the box. The corresponding 10% variation in the Maxwell stress launches a zonal flow of alternating sub- and super-Keplerian velocity. This, in turn, generates a banded density structure in geostrophic balance between pressure and Coriolis forces. We present a simplified model for the appearance of zonal flows, in which stochastic forcing by the magnetic tension on short timescales creates zonal flow structures with lifetimes of several tens of orbits. We experiment with various improved shearing box algorithms to reduce the numerical diffusivity introduced by the supersonic shear flow. While a standard finite difference advection scheme shows signs of a suppression of turbulent activity near the edges of the box, this problem is eliminated by a new method where the Keplerian shear advection is advanced in time by interpolation in Fourier space.

Does the Well-Being of Individuals with Down Syndrome and Dementia Improve When Using Life Story Books and Rummage Boxes? A Randomized Single Case Series Experiment

ERIC Educational Resources Information Center

Crook, Nicola; Adams, Malcolm; Shorten, Nicola; Langdon, Peter E.

2016-01-01

Background: This study investigated whether a personalized life story book and rummage box enhanced well-being and led to changes in behaviour for people with Down syndrome (DS) who have dementia. Materials and Methods: A randomized single case series design was used with five participants who had DS and a diagnosis of dementia. Participants were…

Can an Agent's False Belief Be Corrected by an Appropriate Communication? Psychological Reasoning in 18-Month-Old Infants

ERIC Educational Resources Information Center

Song, Hyun-joo; Onishi, Kristine H.; Baillargeon, Renee; Fisher, Cynthia

2008-01-01

Do 18-month-olds understand that an agent's false belief can be corrected by an appropriate, though not an inappropriate, communication? In Experiment 1, infants watched a series of events involving two agents, a ball, and two containers: a box and a cup. To start, agent 1 played with the ball and then hid it in the box, while agent 2 looked on.…

Biology, Management and Utilization of Common Reed Pharagnites australis.

DTIC Science & Technology

1987-02-01

Vrije Universiteit Waterways Experiment Staticn Department of Ecology and Ecotoxicology Environmental Laboratory P.O. Box 7161 P.O. Box 631 1007 MC...Madelijn van der Werff Vrije Universiteit Department of Ecology and Ecotoxicology Amsterdam and John W. Simmers and Stratford H. Kay Waterways...lowing and cutting 67 5.2.4. Active regulation of the water table 68 5.5. Nature conservation 68 5.4. Reed cultivation 69 Z.4. 1. Reed harvest 69 6

Blast Load Simulator Experiments for Computational Model Validation: Report 1

DTIC Science & Technology

2016-08-01

involving the inclusion of non-responding box-type structures in a BLS simulated blast environment. The BLS is a highly tunable com- pressed-gas-driven...Blast Load Simulator (BLS) to evaluate its suitability for a future effort involving the inclusion of non-responding box-type structures located in...Recommendations Preliminary testing indicated that inclusion of the grill and diaphragm striker resulted in a decrease in peak pressure of about 12

Can pore-clogging by ash explain post-fire runoff?

USGS Publications Warehouse

Stoof, Cathelijne R.; Gevaert, Anouk I.; Baver, Christine; Hassanpour, Bahareh; Morales, Veronica L.; Zhang, Wei; Martin, Deborah; Giri, Shree K.; Steenhuis, Tammo S.

2016-01-01

Ash plays an important role in controlling runoff and erosion processes after wildfire and has frequently been hypothesised to clog soil pores and reduce infiltration. Yet evidence for clogging is incomplete, as research has focussed on identifying the presence of ash in soil; the actual flow processes remain unknown. We conducted laboratory infiltration experiments coupled with microscope observations in pure sands, saturated hydraulic conductivity analysis, and interaction energy calculations, to test whether ash can clog pores (i.e. block pores such that infiltration is hampered and ponding occurs). Although results confirmed previous observations of ash washing into pores, clogging was not observed in the pure sands tested, nor were conditions found for which this does occur. Clogging by means of strong attachment of ash to sand was deemed unlikely given the negative surface charge of the two materials. Ponding due to washing in of ash was also considered improbable given the high saturated conductivity of pure ash and ash–sand mixtures. This first mechanistic step towards analysing ash transport and attachment processes in field soils therefore suggests that pore clogging by ash is unlikely to occur in sands. Discussion is provided on other mechanisms by which ash can affect post-fire hydrology.

Effect of bovine manure on fecal coliform attachment to soil and soil particles of different sizes.

PubMed

Guber, Andrey K; Pachepsky, Yakov A; Shelton, Daniel R; Yu, Olivia

2007-05-01

Manure-borne bacteria can be transported in runoff as free cells, cells attached to soil particles, and cells attached to manure particles. The objectives of this work were to compare the attachment of fecal coliforms (FC) to different soils and soil fractions and to assess the effect of bovine manure on FC attachment to soil and soil fractions. Three sand fractions of different sizes, the silt fraction, and the clay fraction of loam and sandy clay loam soils were separated and used along with soil samples in batch attachment experiments with water-FC suspensions and water-manure-FC suspensions. In the absence of manure colloids, bacterial attachment to soil, silt, and clay particles was much higher than the attachment to sand particles having no organic coating. The attachment to the coated sand particles was similar to the attachment to silt and clay. Manure colloids in suspensions decreased bacterial attachment to soils, clay and silt fractions, and coated sand fractions, but did not decrease the attachment to sand fractions without the coating. The low attachment of bacteria to silt and clay particles in the presence of manure colloids may cause predominantly free-cell transport of manure-borne FC in runoff.

Different depth intermittent sand filters for laboratory treatment of synthetic wastewater with concentrations close to measured septic tank effluent.

PubMed

Rodgers, M; Walsh, G; Healy, M G

2011-01-01

The objective of this study was to apply hydraulic and chemical oxygen demand (COD) loading rates at the upper limits of the design criteria for buried sand filters to test the sand filter depth design criteria. Over a 274-day study duration, synthetic effluent with a strength of domestic wastewater was intermittently dosed onto two sand filters of 0.2 m diameter, with depths of 0.3 and 0.4 m. Hydraulic and organic carbon loading rates of 105 L m(-2) d(-1) and 40 g COD m(-2) d(-1), respectively, were applied to the filters. The filters did not clog and had good effluent removal capabilities for 274 and 190 days, respectively. However, the 0.3 m-deep filter did experience a reduced performance towards the end of the study period. In the 0.3 and 0.4 m-deep filters, the effluent COD and SS concentrations were less than 86 and 31 mg L(-1), respectively, and nitrification was nearly complete in both these columns. Ortho-phosphorus (PO(4)-P) removal in fine sand and laterite 'upflow' filters, receiving effluent from the 0.3 m-deep filter, was 10% and 44%, respectively.

A Plant That Escapes from a Locked Box...and Other Growing Experiments.

ERIC Educational Resources Information Center

Kirkman, Will

1979-01-01

Seven easy-to-do experiments with plants are outlined to aid in teaching children about plants: their search for water, food, and light; a variety of rooting systems; and the effects of soil temperatures. (JMF)

Simulating the injection of micellar solutions to recover diesel in a sand column.

PubMed

Bernardez, Letícia A; Therrien, René; Lefebvre, René; Martel, Richard

2009-01-26

This paper presents numerical simulations of laboratory experiments where diesel, initially present at 18% residual saturation in a sand column, was recovered by injecting a micellar solution containing the surfactant Hostapur SAS-60 (SAS), and two alcohols, n-butanol (n-BuOH), and n-pentanol (n-PeOH). The micellar solution was developed and optimized for diesel recovery using phase diagrams and soil column experiments. Numerical simulations with the compositional simulator UTCHEM agree with the experimental results and show that the entire residual diesel in the sand column was recovered after the downward injection of 5 pore volumes of the micellar solution. Recovery of diesel occurs by enhanced solubility in the microemulsion phase and by mobilization. An additional series of simulations investigated the effects of phase transfer, alcohol partitioning, and component segregation on diesel recovery. These simulations indicate that diesel can be accurately represented in the model by a single component, but that the pseudo-component approach for active matter and the assumption of local phase equilibrium leads to an underestimation of diesel mobilization.

Simulating the injection of micellar solutions to recover diesel in a sand column

NASA Astrophysics Data System (ADS)

Bernardez, Letícia A.; Therrien, René; Lefebvre, René; Martel, Richard

2009-01-01

This paper presents numerical simulations of laboratory experiments where diesel, initially present at 18% residual saturation in a sand column, was recovered by injecting a micellar solution containing the surfactant Hostapur SAS-60 (SAS), and two alcohols, n-butanol ( n-BuOH), and n-pentanol ( n-PeOH). The micellar solution was developed and optimized for diesel recovery using phase diagrams and soil column experiments. Numerical simulations with the compositional simulator UTCHEM agree with the experimental results and show that the entire residual diesel in the sand column was recovered after the downward injection of 5 pore volumes of the micellar solution. Recovery of diesel occurs by enhanced solubility in the microemulsion phase and by mobilization. An additional series of simulations investigated the effects of phase transfer, alcohol partitioning, and component segregation on diesel recovery. These simulations indicate that diesel can be accurately represented in the model by a single component, but that the pseudo-component approach for active matter and the assumption of local phase equilibrium leads to an underestimation of diesel mobilization.

Acid rock drainage passive remediation using alkaline clay: Hydro-geochemical study and impacts of vegetation and sand on remediation.

PubMed

Plaza, Fernando; Wen, Yipei; Liang, Xu

2018-10-01

Acid rock drainage (ARD) is one of the most adverse environmental problems of the mine industry, especially in regions with an abundance of coal refuse (CR) deposits (e.g. the Northern Appalachian Coalfield in the USA) where surface and ground waters are affected by this pollution due to the acidity and high content of sulfates and heavy metals. This study explores the effectiveness of the ARD passive remediation method using alkaline clay (AC) through a series of static and long-term kinetic laboratory experiments (over three years) complemented with field measurements and geochemical modeling. Two important issues associated with this passive and auto-sustainable ARD remediation method were investigated: 1) the hydrogeochemical study of the mixture in terms of the percentages of AC and CR, and, 2) impacts of vegetation cover and a saturated sand barrier on the remediation. Both the field measurements and the samples used for the experiments came from a local coal waste site. Through the analysis of the field measurements and the outcome of the laboratory experiments and the geochemical modeling, alkaline clay proved to be an effective remediation material for ARD, in terms of achieving a neutral pH in the leachate and immobilization of sulfate and metals such as Fe, Mn, Cu, Zn, Ni, Pb, Cd, Co. Moreover, it has been demonstrated that the use of vegetation and a saturated sand barrier are beneficial. Vegetation acted as a phytoaccumulation/phytoextraction agent, causing an additional immobilization of metals. The saturated sand barrier blocked downward the oxygen and water diffusion, reducing pyrite oxidation rates. The proposed remediation approach ensures that the acidity consumption will likely occur before all the alkalinity is exhausted. Copyright © 2018 Elsevier B.V. All rights reserved.

Shear History Extensional Rheology Experiment: A Proposed ISS Experiment

NASA Technical Reports Server (NTRS)

Hall, Nancy R.; Logsdon, Kirk A.; Magee, Kevin S.

2007-01-01

The Shear History Extensional Rheology Experiment (SHERE) is a proposed International Space Station (ISS) glovebox experiment designed to study the effect of preshear on the transient evolution of the microstructure and viscoelastic tensile stresses for monodisperse dilute polymer solutions. Collectively referred to as Boger fluids, these polymer solutions have become a popular choice for rheological studies of non-Newtonian fluids and are the non-Newtonian fluid used in this experiment. The SHERE hardware consists of the Rheometer, Camera Arm, Interface Box, Cabling, Keyboard, Tool Box, Fluid Modules, and Stowage Tray. Each component will be described in detail in this paper. In the area of space exploration, the development of in-situ fabrication and repair technology represents a critical element in evolution of autonomous exploration capability. SHERE has the capability to provide data for engineering design tools needed for polymer parts manufacturing systems to ensure their rheological properties have not been impacted in the variable gravity environment and this will be briefly addressed.

Experimental Study on Clogging of Fine Particles in Sand Sediments

NASA Astrophysics Data System (ADS)

Hirabayashi, S.

2015-12-01

In the methane hydrate development from the sand sediment beneath the seafloor, it is anticipated that the migrating fine particles may block the pore and consequently reduces the permeability near the production well. Although this phenomenon is known as skin formation, its microscopic mechanism is still unknown. As a part of a Japanese National hydrate research program (MH21, funded by METI), we carried out an experiment on the clogging of fine particles in sand sediments. A transparent core holder was newly developed to directly visualize the behavior of fine particles in the pore of frame sands and formation of skin. It was observed that there seems to be an induction time before the clogging starts to occur. Once clogging occurs, the upstream fine particles cannot move downstream anymore and the skin is formed. It was found that the rate of skin formation is related to the total volume of injected fine particles while the flow velocity has something to do with the length of the induction time.

Microbial shaping of wrinkle structures in siliciclastic deposits

NASA Astrophysics Data System (ADS)

Bosak, T.; Mariotti, G.; Pruss, S. B.; Perron, J.; O'Grady, M.

2013-12-01

Wrinkle structures are millimeter- to centimeter-scale elongated or reticulate sedimentary structures that resemble symmetric ripples. Sharp-crested and flat-topped wrinkle structures up to 1 cm wide occur on numerous bedding planes in the Neoproterozoic and Cambrian, as well as in some Archean and Phanerozoic siliciclastic deposits. Because similar, but unlithified structures occur in some modern, microbially-colonized sands, wrinkle structures are typically interpreted as microbially induced sedimentary structures. However, it is unclear if physical processes, such as the motion of suspended sand grains, can produce similar features in sand even before microbial colonization. We introduced mat fragments to the surface of silica sand in wave tanks and generated sharp-crested, flat-topped and pitted wrinkle structures. The abrasion of the sandy surface by rolling, low density, millimeter-size fragments of microbial mats produces wrinkle structures at extremely weak orbital velocities that cannot move sand grains in the absence of light particles. Wrinkle structures form in a few hours and can become colonized by microbial mats within weeks. Thus, wrinkle structures are patterns formed by microbially mediated sand motion at low orbital velocities in the absence of bioturbation. Once formed, wrinkle structures can be colonized and stabilized by microbial mats, but the shape of these mats does not dictate the shape of wrinkle structures. These experiments bolster the interpretation of wrinkle structures as morphological signatures of organic particles and early life in Archean and Proterozoic siliciclastic deposits.

Preferential Flow and Transport of Cryptosporidium Parvum Oocysts Through Vadose Zone: Experiments and Modeling

NASA Astrophysics Data System (ADS)

Darnault, C. J.; Darnault, C. J.; Garnier, P.; Kim, Y.; Oveson, K.; Jenkins, M.; Ghiorse, W.; Baveye, P.; Parlange, J.; Steenhuis, T.

2001-12-01

Oocysts of the protozoan Cryptosporidium parvum, when they contaminate drinking water supplies, can cause outbreaks of Cryptosporidiosis, a common waterborne disease. Of the different pathways by which oocysts can wind up in drinking water, one has received very little attention to date; because soils are often considered to be perfect filters, the transport of oocysts through the subsoil to groundwater by preferential flow is generally ignored. To evaluate its significance, three set of laboratory experiments investigated transport of oocysts through vadose zone. Experiment set I was carried out in a vertical 50 cm-long column filled with silica sand, under conditions known to foster fingered flow. Experiment set II investigates the effect of gas-water interfaces by modifying the hydrodynamical conditions in the sand columns with water-repellent sand barriers. Experiment III involved undisturbed soil columns subjected to macropores flow. The sand and soil columns were subjected to artificial rainfall and were allowed to reach steady-state. At that point, feces of contaminated calves were applied at the surface, along with a known amount of KCl to serve as tracer, and rainfall was continued at the same rate. The breakthrough of oocysts and Cl-, monitored in the effluent, demonstrate the importance of preferential flow - fingered flow and macropore flow - on the transport of oocysts through vadose zone. Peak oocyst concentrations were not appreciably delayed, compared to Cl-, and in some cases, occurred even before the Cl- peak. However, the numbers of oocysts present in the effluents were still orders of magnitude higher than the 5 to 10 oocysts per liter that are considerable sufficient to cause cryptosporidiosis in healthy adults. The transport of oocysts was simulated based on a partitioning the soil profile in both a distribution zone and a preferential zone, In particular, the model simulates accurately the markedly asymmetric breakthrough patterns, and the long exponential tailing. The spatial distribution of oocysts suggest a close relationship between oocyst retention and the extent of gas-water interfaces; sharp increases in oocyst numbers are consistently observed in regions of the sand where the water content has steep gradients, and therefore where one expects capillary meniscii to have maximal extent. These observations imply that oocyst transport in the vadose zone is likely to be very limited in the absence of preferential flow. However, experimental results suggest that the transport of oocysts in the subsurface via preferential flow may create a significant risk of groundwater contamination in some situations.

Purification and DNA-binding properties of the cro-type regulatory repressor protein cng encoded by the Lactobacillus plantarum phage phi g1e.

PubMed

Kakikawa, M; Ohkubo, S; Sakate, T; Sayama, M; Taketo, A; Kodaira, K

2000-05-16

The putative repressor protein Cng (10kDa on an SDS gel) for the lytic pathway of Lactobacillus plantarum phage φg1e was purified using the Escherichia coli Pt7 system, and its DNA-binding ability for the seven operator-like sequences, the GATAC-boxes (Gb1 to Gb7), was investigated in vitro. In gel-shift assays, Cng selectively bound to the DNA fragments containing the GATAC-box(es). In addition, DNase I footprinting analysis with supercoiled DNA demonstrated that Cng can specifically cover about a 25bp region centered around each of the GATAC-boxes, although two boxes, Gb4 and Gb6, were only partially protected. Moreover, protein crosslinking experiments using glutaraldehyde suggested that Cng most likely functions as a dimer. On the other hand, the binding ability of Cpg for the GATAC-boxes in supercoiled DNA was also examined under the same conditions as in Cng; unlike Cng, Cpg covered Gb4 and Gb6 completely sufficiently as well as the other five boxes. Thus, the present and previous [Kakikawa et al., Gene 215 (1998) 371-379; 242 (2000) 155-166] results indicate a possibility that the two proteins Cng and Cpg selectively bind to the GATAC-boxes that act as operators, and can decide between the lytic or lysogenic pathways through repression of the promoter activity of P(R) as well as P(L).

Opening Pandora's Box: The impact of open system modeling on interpretations of anoxia

NASA Astrophysics Data System (ADS)

Hotinski, Roberta M.; Kump, Lee R.; Najjar, Raymond G.

2000-06-01

The geologic record preserves evidence that vast regions of ancient oceans were once anoxic, with oxygen levels too low to sustain animal life. Because anoxic conditions have been postulated to foster deposition of petroleum source rocks and have been implicated as a kill mechanism in extinction events, the genesis of such anoxia has been an area of intense study. Most previous models of ocean oxygen cycling proposed, however, have either been qualitative or used closed-system approaches. We reexamine the question of anoxia in open-system box models in order to test the applicability of closed-system results over long timescales and find that open and closed-system modeling results may differ significantly on both short and long timescales. We also compare a scenario with basinwide diffuse upwelling (a three-box model) to a model with upwelling concentrated in the Southern Ocean (a four-box model). While a three-box modeling approach shows that only changes in high-latitude convective mixing rate and character of deepwater sources are likely to cause anoxia, four-box model experiments indicate that slowing of thermohaline circulation, a reduction in wind-driven upwelling, and changes in high-latitude export production may also cause dysoxia or anoxia in part of the deep ocean on long timescales. These results suggest that box models must capture the open-system and vertically stratified nature of the ocean to allow meaningful interpretations of long-lived episodes of anoxia.

Aeolian transport in the field: A comparison of the effects of different surface treatments

NASA Astrophysics Data System (ADS)

Dong, Zhibao; Lv, Ping; Zhang, Zhengcai; Qian, Guangqiang; Luo, Wanyin

2012-05-01

Aeolian transport represents the result of wind-surface interactions, and therefore depends strongly on variations in the characteristics of the sediment surface. We conducted field observations of aeolian transport of typical dune sand in three 80 m × 80 m plots with different surface treatments: gravel-covered sand, enclosed shifting sand, and open (unprotected) shifting sand. The study was performed at the Shapotou Aeolian Experiment Site in the southeastern part of China's Tengger Desert to compare the effects of these different surface treatments on aeolian transport. To do so, we analyzed the flux density profiles and transport rates above each surface. The flux density profiles for all three treatments followed the exponential decay law that was proposed by most previous researchers to describe the saltation flux density profiles. Coefficients of the exponential decay function were defined as a function of the surface and the wind velocity. The enclosed and open plots with shifting sand had similar flux density profiles, but the flux density above gravel-covered plots showed that transport decayed more slowly with increasing height, producing flux density profiles with a higher average saltation height. The transport rate above the three treatment plots tended to increase proportionally with the cube of the mean wind velocity and with the maximum wind velocity during the observation period, but was more strongly correlated with the square of drift potential. Transport rates above the plot with open shifting sand were greater than those above the plots with enclosed shifting sand and the gravel-covered plot.

Impact of Rotylenchulus reniformis on Cotton Yield as Affected by Soil Texture and Irrigation

PubMed Central

Herring, Stephanie L.; Heitman, Joshua L.

2010-01-01

The effects of soil type, irrigation, and population density of Rotylenchulus reniformis on cotton were evaluated in a two-year microplot experiment. Six soil types, Fuquay sand, Norfolk sandy loam, Portsmouth loamy sand, Muck, Cecil sandy loam, and Cecil sandy clay, were arranged in randomized complete blocks with five replications. Each block had numerous plots previously inoculated with R. reniformis and two or more noninoculated microplots per soil type, one half of which were irrigated in each replicate for a total of 240 plots. Greatest cotton lint yields were achieved in the Muck, Norfolk sandy loam, and Portsmouth loamy sand soils. Cotton yield in the Portsmouth loamy sand did not differ from the Muck soil which averaged the greatest lint yield per plot of all soil types. Cotton yield was negatively related to R. reniformis PI (initial population density) in all soil types except for the Cecil sandy clay which had the highest clay content. Supplemental irrigation increased yields in the higher yielding Muck, Norfolk sandy loam, and Portsmouth loamy sand soils compared to the lower yielding Cecil sandy clay, Cecil sandy loam, and Fuquay sand soils. The Portsmouth sandy loam was among the highest yielding soils, and also supported the greatest R. reniformis population density. Cotton lint yield was affected more by R. reniformis Pi with irrigation in the Portsmouth loamy sand soil with a greater influence of Pi on lint yield in irrigated plots than other soils. A significant first degree PI × irrigation interaction for this soil type confirms this observation. PMID:22736865

Impact of Rotylenchulus reniformis on Cotton Yield as Affected by Soil Texture and Irrigation.

PubMed

Herring, Stephanie L; Koenning, Stephen R; Heitman, Joshua L

2010-12-01

The effects of soil type, irrigation, and population density of Rotylenchulus reniformis on cotton were evaluated in a two-year microplot experiment. Six soil types, Fuquay sand, Norfolk sandy loam, Portsmouth loamy sand, Muck, Cecil sandy loam, and Cecil sandy clay, were arranged in randomized complete blocks with five replications. Each block had numerous plots previously inoculated with R. reniformis and two or more noninoculated microplots per soil type, one half of which were irrigated in each replicate for a total of 240 plots. Greatest cotton lint yields were achieved in the Muck, Norfolk sandy loam, and Portsmouth loamy sand soils. Cotton yield in the Portsmouth loamy sand did not differ from the Muck soil which averaged the greatest lint yield per plot of all soil types. Cotton yield was negatively related to R. reniformis PI (initial population density) in all soil types except for the Cecil sandy clay which had the highest clay content. Supplemental irrigation increased yields in the higher yielding Muck, Norfolk sandy loam, and Portsmouth loamy sand soils compared to the lower yielding Cecil sandy clay, Cecil sandy loam, and Fuquay sand soils. The Portsmouth sandy loam was among the highest yielding soils, and also supported the greatest R. reniformis population density. Cotton lint yield was affected more by R. reniformis Pi with irrigation in the Portsmouth loamy sand soil with a greater influence of Pi on lint yield in irrigated plots than other soils. A significant first degree PI × irrigation interaction for this soil type confirms this observation.

Penetration and blown-air effect in sand

NASA Astrophysics Data System (ADS)

Clement, R.; Courrech du Pont, S.; Douady, S.

2012-04-01

Sand is known to show a variety of uncommon physical features that do not fit the behavior of liquid or solid state. A good example of the inherent difficulties encountered when trying to describe collective grains behavior is the penetration of an intruding object into a granular medium. Such problems involve large coordination numbers, and the medium response dramatically depends on the volume fraction. On the fringe of these studies, we consider here the penetration of a cylindrical shell (typically an upside down glass) into dry sand, and report what we called the "blown-air effect". The air initially trapped escapes when the shell is pushed into sand, flowing through the granular medium. This flow dilates the sand and considerably eases the penetration of the shell. This is very different from what happens in liquids: when pushing a top-closed shell into a liquid, the trapped air increases the buoyancy and opposes the penetration. We show that the air flow does not change the general dynamics of penetration, suggesting that fluidization only involves an effective smaller volume fraction. Despite its simplicity (only a glass and some sand are needed to observe the effect), this experiment nicely illustrates the sometimes counter-intuitive behavior of granular media. Penetration in sand is also a critical issue in industry, and this work may help improving burying methods. Ref: Penetration and blown air effect in granular media R. Clément, S. Courrech du Pont, M. Ould-Hamouda, D. Duveau, and S. Douady Phys. Rev. Lett. 2011 Science News: http://news.sciencemag.org/sciencenow/2011/02/convince-your-friends-youre-a-ge.html

Development of low-cost technology for the removal of iron and manganese from ground water in siwa oasis.

PubMed

El-Naggar, Hesham M

2010-01-01

Ground water is the only water resource for Siwa Oasis. It is obtained from natural freshwater wells and springs fed by the Nubian aquifer. Water samples collected from Siwa Oasis had relatively higher iron (Fe) and manganese (Mn) than the permissible limits specified in WHO Guidelines and Egyptian Standards for drinking water quality. Aeration followed by sand filtration is the most commonly used method for the removal of iron from ground water. The study aimed at development of low-cost technology for the removal of iron and manganese from ground water in Siwa Oasis. The study was carried out on Laboratory-scale columns experiments sand filters with variable depths of 15, 30, 45, 60, 75, 90 cm and three graded types of sand were studied. The graded sand (E.S. =0.205 mm, U.C. =3.366, depth of sand = 60 cm and filtration rate = 1.44 m3/m2/hr) was the best type of filter media. Iron and manganese concentrations measured in ground water with aeration only, decreased with an average removal percentage of 16%, 13% respectively. Iron and manganese concentrations after filtration with aeration came down to 0.1123, 0.05 mg/L respectively in all cases from an initial concentration of 1.14, 0.34 mg/L respectively. Advantages of such treatment unit included simplicity, low cost design, and no need for chemical addition. In addition, the only maintenance required was periodic washing of the sand filter or replacement of the sand in order to maintain reasonable flow rate through the system.

Amphibious Landing Operations in World War II: Personal Experience in Applying and Developing Doctrine

DTIC Science & Technology

2015-05-21

location. Additionally, the effect of weather was evident in the inability of some landing craft to free themselves from the beach or avoid foundering in...command vehicle mired it in the soft sand of the beach almost immediately, forcing them to abandon it. The artificial paths troops laid on the beach...to enable vehicle and foot movement over the sand , made of wire and burlap, were not available in large enough quantities to be effective.97 On the

Proceedings of the Conference on the Design of Experiments in Army Research Development and Testing (34th) Held in Las Cruces, New Mexico on 19-21 October 1988

DTIC Science & Technology

1989-07-01

Webb and Linda L.C. Moss.............,,...,....., 27 COMPARISON OF RELIABILITY CONFIDENCE INTERVALS Paul H . Thrasher. ......... . 0 1...Webb and Linda L.C. Moss, U.S. Army Ballistic Research Laboratory COMPARISON OF RELIABILITY CONFIDENCE INTERVALS Paul H. Thrasher, White Sands Missile...RELEVANT Paul H. Thrasher, White Sands Missile Range 0930 - 1000 BREAK 1000 - 1130 GENERAL SESSION III Chairperson: Douglas B. Tang, Valter Reed Army

Proceedings of the Conference on the Design of Experiments in Army Research Development and Testing (36th)

DTIC Science & Technology

1991-08-01

and pressure data collected during the four seasons at White Sands Missile Range, New Mexico , are converted for use in artillery surface-to-surface...155-mm weapon system fired at White Sands Missile Range, New Mexico , did not reach an apogee of 30 km. For the low-angle simulations, the projectile...Range, Now Mexico , during 1989. A sample of 226 rawinsonde flighto containing representative sets for each of the four seasons is used an the met data

Transport characteristics of nanoscale zero-valent iron carried by three different "vehicles" in porous media.

PubMed

Su, Yan; Zhao, Yong S; Li, Lu L; Qin, Chuan Y; Wu, Fan; Geng, Nan N; Lei, Jian S

2014-01-01

This study investigated the transport properties of nanoscale zero-valent iron (Fe(0)) (nZVI) carried by three vehicles: water, sodium dodecyl sulfate (SDS) solution, and SDS foam. Batch experiments were conducted to assess the sedimentation capability of nZVI particles in these three vehicles. Column experiments were conducted to investigate the transport properties of nZVI in porous media formed with different sizes of sand (0.25 mm to 0.5 mm, 0.5 mm to 0.9 mm, and 0.9 mm to 1.4 mm). Three main results were obtained. First, the batch experiments revealed that the stabilities of nZVI particles in SDS solution and SDS foam were improved, compared with that of nZVI particles in water. Moreover, the sedimentation of nZVI in foam was closely associated with the foam drainage volume. The nZVI content in foam was similar to that in the original foaming suspension, and the nZVI particle distribution in foam became significantly more uniform at a stirring speed of 3000 r/min. Second, the transport of nZVI was enhanced by foam compared with water and SDS solution for 0.25 mm to 0.5 mm diameter sand. For sand with diameters of 0.5 mm to 0.9 mm and 0.9 mm to 1.4 mm, the mobility of nZVI carried by SDS solution was optimal, followed by that of nZVI carried by foam and water. Thus, the mobility of nZVI in finer sand was significantly enhanced by foam, compared with that in coarse sand. In contrast, compared with the bare nZVI suspension and nZVI-laden foam, the spatial distribution of nZVI particles carried by SDS solution was significantly uniform along the column length. Third, the SDS concentration significantly influenced the migration of nZVI in porous media. The enhancement in the migration of nZVI carried by SDS solution was greater at an SDS dose of 0.25% compared with that at the other three doses (0.2%, 0.5%, and 1%) for sand with a 0.25 mm to 0.5 mm diameter. Increased SDS concentrations positively affected the transport of nZVI by foam for sand with a 0.25 mm to 0.5 mm diameter, and the SDS concentrations for enhancing the mobility of nZVI carried by SDS foam satisfied the following order: 1% > 0.5% > 0.25% > 0.2%. Thus, SDS solution and SDS foam were better vehicles than water for delivering nZVI particles to porous media for contamination remediation.

The flow of water through culverts.

DOT National Transportation Integrated Search

1926-06-01

This paper presents the results of 3,301 experiments on the flow of water through short conduits such as pipe and box culverts and sluiceways under levees. The experiments were conducted by the Bureau of Public Roads, U.S. Department of Agriculture, ...

Preliminary Advanced Colloids Experiment

NASA Image and Video Library

2011-09-29

ISS029-E-011867 (29 Sept. 2011) --- NASA astronaut Mike Fossum, Expedition 29 commander, works with the Light Microscopy Module (LMM) control box in the Destiny laboratory of the International Space Station in preparation for another session with the Preliminary Advanced Colloids Experiment (PACE) hardware.

Insecticide-impregnated netting as a potential tool for long-lasting control of the leishmaniasis vector Lutzomyia longipalpis in animal shelters

PubMed Central

2013-01-01

Background Leishmaniasis remains a serious neglected disease, with more than 350 million people potentially at risk worldwide. Control strategies often rely on spraying residual insecticides to target populations of the sand fly vectors that transmit Leishmania parasites when blood-feeding. These programmes are often difficult to sustain effectively, as sand fly resting sites must be resprayed on a regular basis. Here, we investigate whether application of insecticide-impregnated netting to a surface could act as an alternative to residual spraying for controlling the American visceral leishmaniasis vector Lutzomyia longipalpis. Methods Female L. longipalpis from our laboratory colony were exposed for 1 h to three treatments applied to plywood surfaces: 2% permethrin-impregnated netting (Olyset®), 20 mg a.i.m-2 micro-encapsulated lambda-cyhalothrin (Demand CS®) and a no-treatment control. We compared the speed at which these treatments acted, by measuring the percentage of sand flies killed both immediately after exposure to the treatment for 1 hour, as well as the number that had died 24 h after the 1 hour exposure. We repeated the experiment at 6 and 12 months following application to test the effectiveness of each treatment over time. Results When first applied, the lambda-cyhalothrin killed more sand flies in the first hour than the permethrin-impregnated netting. However, the effectiveness of the lambda-cyhalothrin diminished over time, so that there was no difference between the two treatments at 12 months. Both killed more sand flies than the control. When measured 24 h following exposure, both test treatments had killed close to 100% of sand flies when first applied, but while the lethal effect of the netting was maintained at close to 100% over 12 months, the effectiveness of the residual insecticide diminished to approximately 80% after 6 months. Conclusions The results of these initial laboratory experiments indicate that covering surfaces with insecticide impregnated netting material may provide a longer-lasting solution for killing sand flies than residual spraying. Field trials are needed to identify the feasibility of treating surfaces with netting or similar impregnated materials as part of a control program. In targeting L. longipalpis, the greatest benefits may be seen in treating animal sheds with netting, where these sand flies aggregate in large numbers, and which can be difficult to treat repeatedly by conventional spraying. PMID:23642213

50 CFR 660.370 - Specifications and management measures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... rebuild overfished species; to enhance the quality of the recreational fishing experience. (iii) Season... overfished species; to avoid waste; to enhance the quality of the recreational fishing experience. (3) All..., rex, rock, and sand soles, Pacific sanddab, and starry flounder) north and south of latitudinal...

[Optimization of vacuum belt drying process of Gardeniae Fructus in Reduning injection by Box-Behnken design-response surface methodology].

PubMed

Huang, Dao-sheng; Shi, Wei; Han, Lei; Sun, Ke; Chen, Guang-bo; Wu Jian-xiong; Xu, Gui-hong; Bi, Yu-an; Wang, Zhen-zhong; Xiao, Wei

2015-06-01

To optimize the belt drying process conditions optimization of Gardeniae Fructus extract from Reduning injection by Box-Behnken design-response surface methodology, on the basis of single factor experiment, a three-factor and three-level Box-Behnken experimental design was employed to optimize the drying technology of Gardeniae Fructus extract from Reduning injection. With drying temperature, drying time, feeding speed as independent variables and the content of geniposide as dependent variable, the experimental data were fitted to a second order polynomial equation, establishing the mathematical relationship between the content of geniposide and respective variables. With the experimental data analyzed by Design-Expert 8. 0. 6, the optimal drying parameter was as follows: the drying temperature was 98.5 degrees C , the drying time was 89 min, the feeding speed was 99.8 r x min(-1). Three verification experiments were taked under this technology and the measured average content of geniposide was 564. 108 mg x g(-1), which was close to the model prediction: 563. 307 mg x g(-1). According to the verification test, the Gardeniae Fructus belt drying process is steady and feasible. So single factor experiments combined with response surface method (RSM) could be used to optimize the drying technology of Reduning injection Gardenia extract.

Stepping outside My Technology Classroom Box (My Summer RET Experience)

ERIC Educational Resources Information Center

Carter, Terry

2008-01-01

In this article, the author shares his summer RET (Research Experience for Teachers) experience. The author describes how his anxiety turned to excitement and anticipation upon entering the college campus in search of new knowledge. He discovered that working side by side with experts in a research facility was so much fun.

Astronaut James D. van Hoften examines student experiment on Challenger

NASA Image and Video Library

1984-04-15

41C-05-188 (12 April 1984) --- Astronaut James D. van Hoften, mission specialist, holds an aluminum box, full of honeybees. The experiment in Earth-orbit is duplicated with another colony of the young honeycomb builders on Earth. Dan Poskevich submitted the experiment to NASA as part of the Shuttle student involvement program.

KSC-2011-4145

NASA Image and Video Library

2011-05-27

CAPE CANAVERAL, Fla. -- Inside the "Lunarena" at the Kennedy Space Center Visitor Complex in Florida, university students maneuver their remote controlled or autonomous excavators, called lunabots, in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

KSC-2011-4157

NASA Image and Video Library

2011-05-28

CAPE CANAVERAL, Fla. -- Inside the "Lunarena" at the Kennedy Space Center Visitor Complex in Florida, university students maneuver their remote controlled or autonomous excavators, called lunabots, in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

KSC-2011-4161

NASA Image and Video Library

2011-05-28

CAPE CANAVERAL, Fla. -- Inside the "Lunarena" at the Kennedy Space Center Visitor Complex in Florida, university students give their "thumbs up" after maneuvering their remote controlled or autonomous excavators, called lunabots, in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

KSC-2011-4150

NASA Image and Video Library

2011-05-27

CAPE CANAVERAL, Fla. -- University students monitor their team's remote controlled or autonomous excavator, called a lunabot, as it is maneuvered in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller