Validation and application of highway safety manual (part D) in Florida : [summary].

DOT National Transportation Integrated Search

2014-02-01

Ongoing surveillance programs on roads and : highways in the U.S. have produced large amounts : of data on many aspects of transportation. : Crash statistics are among the most important : products of these efforts as they help engineers : pinpoint c...

USE OF ALTERED MICROORGANISMS FOR FIELD BIODEGRADATION OF HAZARDOUS MATERIALS

EPA Science Inventory

The large amount of hazardous waste generated and disposed of has given rise to environmental conditions requiring remedial treatment. he use of landfills has traditionally been a cost-effective means to dispose of waste. owever, increased costs of transportation and decreasing n...

Lost in transportation: Information measures and cognitive limits in multilayer navigation.

PubMed

Gallotti, Riccardo; Porter, Mason A; Barthelemy, Marc

2016-02-01

Cities and their transportation systems become increasingly complex and multimodal as they grow, and it is natural to wonder whether it is possible to quantitatively characterize our difficulty navigating in them and whether such navigation exceeds our cognitive limits. A transition between different search strategies for navigating in metropolitan maps has been observed for large, complex metropolitan networks. This evidence suggests the existence of a limit associated with cognitive overload and caused by a large amount of information that needs to be processed. In this light, we analyzed the world's 15 largest metropolitan networks and estimated the information limit for determining a trip in a transportation system to be on the order of 8 bits. Similar to the "Dunbar number," which represents a limit to the size of an individual's friendship circle, our cognitive limit suggests that maps should not consist of more than 250 connection points to be easily readable. We also show that including connections with other transportation modes dramatically increases the information needed to navigate in multilayer transportation networks. In large cities such as New York, Paris, and Tokyo, more than 80% of the trips are above the 8-bit limit. Multimodal transportation systems in large cities have thus already exceeded human cognitive limits and, consequently, the traditional view of navigation in cities has to be revised substantially.

Lost in transportation: Information measures and cognitive limits in multilayer navigation

PubMed Central

Gallotti, Riccardo; Porter, Mason A.; Barthelemy, Marc

2016-01-01

Cities and their transportation systems become increasingly complex and multimodal as they grow, and it is natural to wonder whether it is possible to quantitatively characterize our difficulty navigating in them and whether such navigation exceeds our cognitive limits. A transition between different search strategies for navigating in metropolitan maps has been observed for large, complex metropolitan networks. This evidence suggests the existence of a limit associated with cognitive overload and caused by a large amount of information that needs to be processed. In this light, we analyzed the world’s 15 largest metropolitan networks and estimated the information limit for determining a trip in a transportation system to be on the order of 8 bits. Similar to the “Dunbar number,” which represents a limit to the size of an individual’s friendship circle, our cognitive limit suggests that maps should not consist of more than 250 connection points to be easily readable. We also show that including connections with other transportation modes dramatically increases the information needed to navigate in multilayer transportation networks. In large cities such as New York, Paris, and Tokyo, more than 80% of the trips are above the 8-bit limit. Multimodal transportation systems in large cities have thus already exceeded human cognitive limits and, consequently, the traditional view of navigation in cities has to be revised substantially. PMID:26989769

Carbon Capture and Sequestration (CCS)

DTIC Science & Technology

2009-06-19

tons of CO2 underground each year to help recover oil and gas resources (enhanced oil recovery , or EOR).1 Also, potentially large amounts of CO2 ... CO2 will be used for enhanced gas recovery at a nearby natural gas field. See http://www.vattenfall.com/www/co2_en/ co2_en/Gemeinsame_Inhalte...for enhanced oil recovery (EOR).18 Transporting CO2 in pipelines is similar to transporting petroleum products like natural gas and oil; it requires

Large-scale bedforms as indicators of mutually evasive sand transport and the sequential infilling of wide-mouthed estuaries

NASA Astrophysics Data System (ADS)

Harris, Peter T.

1988-06-01

Large-scale bedforms (2-10 m in vertical and 10 2-10 3 m in horizontal dimensions) found in wide-mouthed estuaries are described. Different bedform types occur depending upon the local availability of sand. With an increasing sand supply, sand ribbons grade into elongate trains of sand waves and then form sandwave fields. Inshore, headland-associated sand banks are formed which multiply into en-echelon sand banks. Based upon a review of data on directions of sand transport from the Bristol Channel and Thames Estuary, U.K., and from Moreton Bay, Australia, charts of ebb- and flood-dominant transport zones are constructed for lower estuarine environments which have undergone different degrees of infilling. Linear sand banks are seen to delimit partially the boundaries between opposing sand transport zones. Transport paths demonstrate how sediments derived from outside of the estuary are dispersed through ebb and flood transport zones, to supply other areas of net deposition. A comparison between different estuaries reveals that variations in the compexity of ebb- and flood-dominant transport zones and the morphologies of large-scale bedforms are coupled with apparent changes in the relative amounts of sand available to each system. A model for the sequential infilling of estuaries and the evolution of large-scale bedforms is presented and applied to the interpretation of present day examples. Vertical sequences predicted to be generated by such bedform evolution are described and discussed, in terms of their preservation in the geological record.

Large wood in the Snowy River estuary, Australia

NASA Astrophysics Data System (ADS)

Hinwood, Jon B.; McLean, Errol J.

2017-02-01

In this paper we report on 8 years of data collection and interpretation of large wood in the Snowy River estuary in southeastern Australia, providing quantitative data on the amount, sources, transport, decay, and geomorphic actions. No prior census data for an estuary is known to the authors despite their environmental and economic importance and the significant differences between a fluvial channel and an estuarine channel. Southeastern Australian estuaries contain a significant quantity of large wood that is derived from many sources, including river flood flows, local bank erosion, and anthropogenic sources. Wind and tide are shown to be as important as river flow in transporting and stranding large wood. Tidal action facilitates trapping of large wood on intertidal bars and shoals; but channels are wider and generally deeper, so log jams are less likely than in rivers. Estuarine large wood contributes to localised scour and accretion and hence to the modification of estuarine habitat, but in the study area it did not have large-scale impacts on the hydraulic gradients nor the geomorphology.

Tonoplast Sugar Transporters (SbTSTs) putatively control sucrose accumulation in sweet sorghum stems.

PubMed

Bihmidine, Saadia; Julius, Benjamin T; Dweikat, Ismail; Braun, David M

2016-01-01

Carbohydrates are differentially partitioned in sweet versus grain sorghums. While the latter preferentially accumulate starch in the grain, the former primarily store large amounts of sucrose in the stem. Previous work determined that neither sucrose metabolizing enzymes nor changes in Sucrose transporter (SUT) gene expression accounted for the carbohydrate partitioning differences. Recently, 2 additional classes of sucrose transport proteins, Tonoplast Sugar Transporters (TSTs) and SWEETs, were identified; thus, we examined whether their expression tracked sucrose accumulation in sweet sorghum stems. We determined 2 TSTs were differentially expressed in sweet vs. grain sorghum stems, likely underlying the massive difference in sucrose accumulation. A model illustrating potential roles for different classes of sugar transport proteins in sorghum sugar partitioning is discussed.

Specificity, Size, and Frequency of Spaces That Characterize the Mechanism of Bulk Transepithelial Transport of Prions in the Nasal Cavities of Hamsters and Mice

PubMed Central

Ayers, J. I.; Bartz, J. C.

2016-01-01

ABSTRACT Inhalation of infected brain homogenate results in transepithelial transport of prions across the nasal mucosa of hamsters, some of which occurs rapidly in relatively large amounts between cells (A. E. Kincaid, K. F. Hudson, M. W. Richey, and J. C. Bartz, J. Virol 86:12731–12740, 2012, doi:http://dx.doi.org/10.1128/JVI.01930-12). Bulk transepithelial transport in the nasal cavity has not been studied to date. In the present study, we characterized the frequency, size, and specificity of the intercellular spaces that mediate the bulk transport of inhaled prions between cells of mice or hamsters following extranasal inoculation with mock-infected brain homogenate, different strains of prion-infected brain homogenate, or brain homogenate mixed with India ink. Infected or mock-infected inoculum was identified within lymphatic vessels of the lamina propria and in spaces of >5 μm between a small number of cells of the nasal mucosa in >90% of animals from 5 to 60 min after inhalation. The width of the spaces between cells, the amount of the inoculum within the lumen of lymphatic vessels, and the timing of the transport indicate that this type of transport was taking place through preexisting spaces in the nasal cavity that were orders of magnitude wider than what is normally reported for paracellular transport. The indiscriminate rapid bulk transport of brain homogenate in the nasal cavity results in immediate entry into nasal cavity lymphatics following inhalation. This novel mechanism may underlie the recent report of the early detection of prions in blood following inhalation and has implications for horizontal prion transmission. IMPORTANCE The results of these studies demonstrate that the nasal mucosa of mice and hamsters is not an absolute anatomical barrier to inhaled prion-infected or uninfected brain homogenate. Relatively large amounts of infected and uninfected brain homogenate rapidly cross the nasal mucosa and enter the lumen of lymphatic vessels following inhalation. These bulk transepithelial transport events were relatively rare but present in >90% of animals 5 to 60 min following inhalation. This novel mechanism of bulk transepithelial transport was seen in experimental and control hamsters and mice, indicating that it was not species specific or in response to prion exposure. The indiscriminate bulk intercellular transport of inhaled pathogens across the nasal mucosa followed by entry into the lymphatic system may be a mechanism that underlies the entry and spread of other toxins and pathogens in olfactory system-driven animals. PMID:27384659

A review of concentrated flow erosion processes on rangelands: fundamental understanding and knowledge gaps

USDA-ARS?s Scientific Manuscript database

Concentrated flow erosion processes are distinguished from splash and sheetflow processes in their enhanced ability to mobilize and transport large amounts of soil, water and dissolved elements. On rangelands, soil, nutrients and water are scarce and only narrow margins of resource losses are tolera...

Earbuds: A Method for Analyzing Nasality in the Field

ERIC Educational Resources Information Center

Stewart, Jesse; Kohlberger, Martin

2017-01-01

Existing methods for collecting and analyzing nasality data are problematic for linguistic fieldworkers: aerodynamic equipment can be expensive and difficult to transport, and acoustic analyses require large amounts of optimally-recorded data. In this paper, a highly mobile and low-cost method is proposed. By connecting low impedance earbuds into…

Influence of Surface Roughness on the Second Order Transport of Turbulence in Non-Equilibrium Boundary Layers

DTIC Science & Technology

2006-10-08

FINAL REPORT to Air Force Office of Scientific Research (AFOSR) Project Title Influence of Surface Roughness on the Second Order Transport of...large amount of research has been performed to quantify the effects of Mach number, roughness, and wall curvature on turbulent boundary layers. However...18 a) b) c) Figure 3: a) A. D. Smith high pressure storage tank. b) Morin B series actuator controlling Virgo Engineers Trunion Mounted Ball Valve. c

Technologies and Concepts for Reducing the Fuel Burn of Subsonic Transport Aircraft

NASA Technical Reports Server (NTRS)

Nickol, Craig L.

2012-01-01

There are many technologies under development that have the potential to enable large fuel burn reductions in the 2025 timeframe for subsonic transport aircraft relative to the current fleet. This paper identifies a potential technology suite and analyzes the fuel burn reduction potential of these technologies when integrated into advanced subsonic transport concepts. Advanced tube-and-wing concepts are developed in the single aisle and large twin aisle class, and a hybrid-wing-body concept is developed for the large twin aisle class. The resulting fuel burn reductions for the advanced tube-and-wing concepts range from a 42% reduction relative to the 777-200 to a 44% reduction relative to the 737-800. In addition, the hybrid-wingbody design resulted in a 47% fuel burn reduction relative to the 777-200. Of course, to achieve these fuel burn reduction levels, a significant amount of technology and concept maturation is required between now and 2025. A methodology for capturing and tracking concept maturity is also developed and presented in this paper.

Charge transport mechanism in lead oxide revealed by CELIV technique

PubMed Central

Semeniuk, O.; Juska, G.; Oelerich, J.-O.; Wiemer, M.; Baranovskii, S. D.; Reznik, A.

2016-01-01

Although polycrystalline lead oxide (PbO) belongs to the most promising photoconductors for optoelectronic and large area detectors applications, the charge transport mechanism in this material still remains unclear. Combining the conventional time-of-flight and the photo-generated charge extraction by linear increasing voltage (photo-CELIV) techniques, we investigate the transport of holes which are shown to be the faster carriers in poly-PbO. Experimentally measured temperature and electric field dependences of the hole mobility suggest a highly dispersive transport. In order to analyze the transport features quantitatively, the theory of the photo-CELIV is extended to account for the dispersive nature of charge transport. While in other materials with dispersive transport the amount of dispersion usually depends on temperature, this is not the case in poly-PbO, which evidences that dispersive transport is caused by the spatial inhomogeneity of the material and not by the energy disorder. PMID:27628537

Characterizing fate and transport properties in karst aquifers under different hydrologic conditions

NASA Astrophysics Data System (ADS)

Rodriguez, E.; Padilla, I. Y.

2017-12-01

Karst landscapes contain very productive aquifers. The hydraulic and hydrogeological characteristics of karst aquifers make these systems capable of storing and transporting large amount of water, but also highly vulnerable to contamination. Their extremely heterogeneous nature prevents accurate prediction in contaminant fate and transport. Even more challenging is to understand the impact of hydrologic conditions changes on fate and transport processes. This studies aims at characterizing fate and transport processes in the karst groundwater system of northern Puerto Rico under different hydrologic conditions. The study involves injecting rhodamine and uranine dyes into a sinkhole, and monitoring concentrations at a spring. Results show incomplete recovery of tracers, but breaking curves can be used to estimate advective, dispersive and mass transfer characteristic of the karst system. Preliminary results suggest significant differences in fate and transport characteristics under different hydrologic conditions.

Indian Monsoon Low-Pressure Systems Feed Up-and-Over Moisture Transport to the Southwestern Tibetan Plateau

NASA Astrophysics Data System (ADS)

Dong, Wenhao; Lin, Yanluan; Wright, Jonathon S.; Xie, Yuanyu; Xu, Fanghua; Xu, Wenqing; Wang, Yan

2017-11-01

As an integral part of the South Asian summer monsoon system, monsoon low-pressure systems (LPSs) bring large amounts of precipitation to agrarian north and central India during their passage across the subcontinent. In this study, we investigate the role of LPSs in supplying moisture from north and central India to the southwestern Tibetan Plateau (SWTP) and quantify the contribution of these systems to summer rainfall over the SWTP. The results show that more than 60% of total summer rainfall over the SWTP is related to LPS occurrence. LPSs are associated with a 15% rise in average daily rainfall and a 10% rise in rainy days over the SWTP. This relationship is maintained primarily through up-and-over transport, in which convectively lifted moisture over the Indian subcontinent is swept over the SWTP by southwesterly winds in the middle troposphere. LPSs play two roles in supplying up-and-over moisture transport. First, these systems elevate large amounts of water vapor and condensed water to the midtroposphere. Second, the circulations associated with LPSs interact with the background westerlies to induce southwesterly flow in the midtroposphere, transporting elevated moisture and condensate over the Himalayan Mountains. Our findings indicate that LPSs are influential in extending the northern boundary of the South Asian monsoon system across the Himalayas into the interior of the SWTP. The strength of this connection depends on both LPS characteristics and the configuration of the midtropospheric circulation, particularly the prevailing westerlies upstream of the SWTP.

Redox Flow Batteries, a Review

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

Knoxville, U. Tennessee; U. Texas Austin; U, McGill

2011-07-15

Redox flow batteries are enjoying a renaissance due to their ability to store large amounts of electrical energy relatively cheaply and efficiently. In this review, we examine the components of redox flow batteries with a focus on understanding the underlying physical processes. The various transport and kinetic phenomena are discussed along with the most common redox couples.

Influence of hole transport material/metal contact interface on perovskite solar cells

NASA Astrophysics Data System (ADS)

Lei, Lei; Zhang, Shude; Yang, Songwang; Li, Xiaomin; Yu, Yu; Wei, Qingzhu; Ni, Zhichun; Li, Ming

2018-06-01

Interfaces have a significant impact on the performance of perovskite solar cells. This work investigated the influence of hole transport material/metal contact interface on photovoltaic behaviours of perovskite solar devices. Different hole material/metal contact interfaces were obtained by depositing the metal under different conditions. High incident kinetic energy metal particles were proved to penetrate and embed into the hole transport material. These isolated metal particles in hole transport materials capture holes and increase the apparent carrier transport resistance of the hole transport layer. Sample temperature was found to be of great significance in metal deposition. Since metal vapour has a high temperature, the deposition process accumulated a large amount of heat. The heat evaporated the additives in the hole transport layer and decreased the hole conductivity. On the other hand, high temperature may cause iodization of the metal contact.

Influence of hole transport material/metal contact interface on perovskite solar cells.

PubMed

Lei, Lei; Zhang, Shude; Yang, Songwang; Li, Xiaomin; Yu, Yu; Wei, Qingzhu; Ni, Zhichun; Li, Ming

2018-06-22

Interfaces have a significant impact on the performance of perovskite solar cells. This work investigated the influence of hole transport material/metal contact interface on photovoltaic behaviours of perovskite solar devices. Different hole material/metal contact interfaces were obtained by depositing the metal under different conditions. High incident kinetic energy metal particles were proved to penetrate and embed into the hole transport material. These isolated metal particles in hole transport materials capture holes and increase the apparent carrier transport resistance of the hole transport layer. Sample temperature was found to be of great significance in metal deposition. Since metal vapour has a high temperature, the deposition process accumulated a large amount of heat. The heat evaporated the additives in the hole transport layer and decreased the hole conductivity. On the other hand, high temperature may cause iodization of the metal contact.

Artificial transmembrane ion channels from self-assembling peptide nanotubes

NASA Astrophysics Data System (ADS)

Ghadiri, M. Reza; Granja, Juan R.; Buehler, Lukas K.

1994-05-01

NATURALLY occurring membrane channels and pores are formed from a large family of diverse proteins, peptides and organic secon-dary metabolites whose vital biological functions include control of ion flow, signal transduction, molecular transport and produc-tion of cellular toxins. But despite the availability of a large amount of biochemical information about these molecules1, the design and synthesis of artificial systems that can mimic the bio-logical function of natural compounds remains a formidable task2-12. Here we present a simple strategy for the design of artifi-cial membrane ion channels based on a self-assembled cylindrical β-sheet peptide architecture13. Our systems-essentially stacks of peptide rings-display good channel-mediated ion-transport activ-ity with rates exceeding 107 ions s-1, rivalling the performance of many naturally occurring counterparts. Such molecular assemblies should find use in the design of novel cytotoxic agents, membrane transport vehicles and drug-delivery systems.

Impacts of changes in precursor emissions from the San Francisco Bay Area on ozone in the North Central Coast and San Joaquin Valley air basins. Final report

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

Douglas, S.G.; Stoeckenius, T.E.; Austin, B.S.

1991-02-01

The study examined the effect of emissions reductions in the San Francisco Bay Area (SFBA) on ozone levels in the North Central Coast (NCC) and San Joaquin Valley (SJV) air basins. It included an emissions trends analysis for the SFBA, NCC, and SJV air basins; identification of possible transport days and an analysis of ozone trends in both the source and receptor basins on transport and no-transport days; and calculation of interbasin pollutant fluxes using air-quality modeling results. The emissions trends analysis indicated that the SFBA achieved large decreases in emissions of reactive organic gases (ROG) and oxides of nitrogenmore » (NOx) between 1979 and 1988. Despite the large decreases in emissions no significant ozone trends were observed on either transport or no-transport days. Ozone concentrations at the downwind monitors were higher on transport days. Results of the flux plane calculations indicate that elimination of SFBA emissions would significantly reduce ozone concentrations in the NCC and SJV during meteorological conditions conducive to transport and that the lower concentrations in the downwind air basins would be due primarily to a reduction in the amount of precursor pollutants that are transport from the SFBA to the receptor basins.« less

[Effects of slopes on nitrogen transport along with runoff from sloping plots on a lateritic red soil amended with sewage sludge].

PubMed

Chen, Yan-Hui; Chen, Ming-Hua; Wang, Guo; Chen, Wen-Xiang; Yang, Shun-Cheng; Chai, Peng

2010-10-01

The effects of different slopes on nitrogen transport along with runoff from sloping plots amended with sewage sludge on a lateritic red soil were studied under simulated rainfall conditions. When the sludge was broadcasted and mixed with surface soils (BM), the MTN (total nitrogen of mixing sample), STN (total nitrogen of settled sample), TPN (total particulate nitrogen), TSN (total suspended nitrogen), TDN (total dissolved nitrogen) and NH4(+) -N concentrations and nitrogen loss amounts in runoff of all treatments were highest at 1 day or 18 days after application. The highest concentrations and the loss amounts of MTN and STN in the slope runoff for the BM treatment increased with slope degree, showing increasing pollution risks to the surface waters. The STN concentration and loss amounts from the 25 degrees plots were 126.1 mg x L(-1) and 1788.6 mg x m(-2), respectively, being 4.6 times and 5.8 times of the corresponding values from the 10 degrees plots, respectively. Then the concentrations and the loss amounts of nitrogen (except NO3(-) -N) from the BM plots diminished rapidly first and then tended to be stable with dwindling differences between the slopes. The loss of MTN and STN in early runoff (1 day and 18 days) accounted for 68.6% -73.4% and 62.3% -66.7% of the cumulative loss amounts during the experimental period for all the broadcasted treatments. Runoff loss coefficients of MTN increased in the order of 20 degrees > 25 degrees > 15 degrees > 10 degrees. Nitrogen was largely lost in dissolved species while large portion of NH4(+) -N was lost with particulates.

Impact of downslope soil transport on carbon storage and fate in permafrost dominated landscapes

NASA Astrophysics Data System (ADS)

Shelef, E.; Rowland, J. C.; Wilson, C. J.; Altmann, G.; Hilley, G. E.

2014-12-01

A large fraction of high latitude permafrost-dominated landscapes are covered by soil mantled hillslopes. In these landscapes, soil organic carbon (SOC) accumulates and is lost through lateral transport processes. At present, these processes are not included in regional or global landsurface climate models. We present preliminary results of a soil transport and storage model over a permafrost dominated hillslope. In this model soil carbon is transported downslope within a mobile layer that thaws every summer. The model tracks soil transport and its subsequent storage at the hillslope's base. In a scenario where a carbon poor subsurface is blanketed by a carbon-rich surface layer, the progressive downslope soil transport can result in net carbon sequestration. This sequestration occurs because SOC is carried from the hilllsope's near-surface layer, where it is produced by plants and is capable of decomposing, into depositional sites at the hillslope's base where it is stored in frozen deposits such that it's decomposition rate is effectively zero. We use the model to evaluate the quantities of carbon stored in depositional settings during the Holocene, and to predict changes in sequestration rate in response to thaw depth thickening expected to occur within the next century due to climate-change. At the Holocene time scale, we show that a large amount of SOC is likely stored in depositional sites that comprise only a small fraction of arctic landscapes. The convergent topography of these sites makes them susceptible to fluvial erosion and suggests that increased fluvial incision in response to climate-change-induced thawing has the potential to release significant amounts of carbon to the river system, and potentially to the atmosphere. At the time scale of the next century, increased thaw depth may increase soil-transport rates on hillslopes and therefore increase SOC sequestration rates at a magnitude that may partly compensate for the carbon release expected from permafrost thawing. Model guided field data collection is essential to reduce the uncertainty of these estimates.

Na+-independent transporters, LAT-2 and b0,+, exchange L-DOPA with neutral and basic amino acids in two clonal renal cell lines.

PubMed

Gomes, P; Soares-da-Silva, P

2002-03-15

The present study examined the functional characteristics of L-DOPA transporters in two functionally different clonal subpopulations of opossum kidney (OKLC and OKHC) cells. The uptake of L-DOPA was largely Na+-independent, though in OKHC cells a minor component (approximately 15%) required extracellular Na+. At least two Na+-independent transporters appear to be involved in L-DOPA uptake. One of these transporters has a broad specificity for small and large neutral amino acids, is stimulated by acid pH and inhibited by 2-aminobicyclo(2,2,l)-heptane-2-carboxylic acid (BCH; OKLC, Ki = 291 mM; OKHC, Ki = 380 mM). The other Na+-independent transporter binds neutral and basic amino acids and also recognizes the di-amino acid cystine. [14C]-L-DOPA efflux from OKLC and OKHC cells over 12 min corresponded to a small amount of intracellular [14C]-L-DOPA. L-Leucine, nonlabelled L-DOPA, BCH and L-arginine, stimulated the efflux of [14C]-L-DOPA in a Na+-independent manner. It is suggested that L-DOPA uses at least two major transporters, systems LAT-2 and b0,+. The transport of L-DOPA by LAT-2 corresponds to a Na+-independent transporter with a broad specificity for small and large neutral amino acids, stimulated by acid pH and inhibited by BCH. The transport of L-DOPA by system b0,+ is a Na+-independent transporter for neutral and basic amino acids that also recognizes cystine. LAT-2 was found equally important at the apical and basolateral membranes, whereas system b0,+ had a predominant distribution in apical membranes.

System Proposal for Mass Transit Service Quality Control Based on GPS Data

PubMed Central

Padrón, Gabino; Cristóbal, Teresa; Alayón, Francisco; Quesada-Arencibia, Alexis; García, Carmelo R.

2017-01-01

Quality is an essential aspect of public transport. In the case of regular public passenger transport by road, punctuality and regularity are criteria used to assess quality of service. Calculating metrics related to these criteria continuously over time and comprehensively across the entire transport network requires the handling of large amounts of data. This article describes a system for continuously and comprehensively monitoring punctuality and regularity. The system uses location data acquired continuously in the vehicles and automatically transferred for analysis. These data are processed intelligently by elements that are commonly used by transport operators: GPS-based tracking system, onboard computer and wireless networks for mobile data communications. The system was tested on a transport company, for which we measured the punctuality of one of the routes that it operates; the results are presented in this article. PMID:28621745

System Proposal for Mass Transit Service Quality Control Based on GPS Data.

PubMed

Padrón, Gabino; Cristóbal, Teresa; Alayón, Francisco; Quesada-Arencibia, Alexis; García, Carmelo R

2017-06-16

Quality is an essential aspect of public transport. In the case of regular public passenger transport by road, punctuality and regularity are criteria used to assess quality of service. Calculating metrics related to these criteria continuously over time and comprehensively across the entire transport network requires the handling of large amounts of data. This article describes a system for continuously and comprehensively monitoring punctuality and regularity. The system uses location data acquired continuously in the vehicles and automatically transferred for analysis. These data are processed intelligently by elements that are commonly used by transport operators: GPS-based tracking system, onboard computer and wireless networks for mobile data communications. The system was tested on a transport company, for which we measured the punctuality of one of the routes that it operates; the results are presented in this article.

Regulation of NF-κB Oscillation by Nuclear Transport: Mechanisms Determining the Persistency and Frequency of Oscillation

PubMed Central

Ohshima, Daisuke; Ichikawa, Kazuhisa

2015-01-01

The activated transcription factor NF-κB shuttles between the cytoplasm and the nucleus resulting in the oscillation of nuclear NF-κB (NF-κBn). The oscillation pattern of NF-κBn is implicated in the regulation of gene expression profiles. Using computational models, we previously reported that spatial parameters, such as the diffusion coefficient, nuclear to cytoplasmic volume ratio, transport through the nuclear envelope, and the loci of translation of IκB protein, modified the oscillation pattern of NF-κBn. In a subsequent report, we elucidated the importance of the “reset” of NF-κBn (returning of NF-κB to the original level) and of a “reservoir” of IκB in the cytoplasm. When the diffusion coefficient of IκB was large, IκB stored at a distant location from the nucleus diffused back to the nucleus and “reset” NF-κBn. Herein, we report mechanisms that regulate the persistency and frequency of NF-κBn oscillation by nuclear transport. Among the four parameters of nuclear transport tested in our spatio-temporal computational model, the export of IκB mRNA from the nucleus regulated the persistency of oscillation. The import of IκB to the nucleus regulated the frequency of oscillation. The remaining two parameters, import and export of NF-κB to and from the nucleus, had virtually no effect on the persistency or frequency. Our analyses revealed that lesser export of IκB mRNA allowed NF-κBn to transcript greater amounts of IκB mRNA, which was retained in the nucleus, and was subsequently exported to the cytoplasm, where large amounts of IκB were synthesized to “reset” NF-κBn and drove the persistent oscillation. On the other hand, import of greater amounts of IκB led to an increase in the influx and the efflux of NF-κB to and from the nucleus, resulting in an increase in the oscillation frequency. Our study revealed the importance of nuclear transport in regulating the oscillation pattern of NF-κBn. PMID:26042739

Angular Momentum Transport in Thin Magnetically Arrested Disks

NASA Astrophysics Data System (ADS)

Marshall, Megan D.; Avara, Mark J.; McKinney, Jonathan C.

2018-05-01

In accretion disks with large-scale ordered magnetic fields, the magnetorotational instability (MRI) is marginally suppressed, so other processes may drive angular momentum transport leading to accretion. Accretion could then be driven by large-scale magnetic fields via magnetic braking, and large-scale magnetic flux can build-up onto the black hole and within the disk leading to a magnetically-arrested disk (MAD). Such a MAD state is unstable to the magnetic Rayleigh-Taylor (RT) instability, which itself leads to vigorous turbulence and the emergence of low-density highly-magnetized bubbles. This instability was studied in a thin (ratio of half-height H to radius R, H/R ≈ 0.1) MAD simulation, where it has a more dramatic effect on the dynamics of the disk than for thicker disks. Large amounts of flux are pushed off the black hole into the disk, leading to temporary decreases in stress, then this flux is reprocessed as the stress increases again. Throughout this process, we find that the dominant component of the stress is due to turbulent magnetic fields, despite the suppression of the axisymmetric MRI and the dominant presence of large-scale magnetic fields. This suggests that the magnetic RT instability plays a significant role in driving angular momentum transport in MADs.

River basin affected by rare perturbation events: the Chaiten volcanic eruption.

NASA Astrophysics Data System (ADS)

Picco, Lorenzo; Iroumé, Andrés; Oss-Cazzador, Daniele; Ulloa, Hector

2017-04-01

Natural disasters can strongly and rapidly affect a wide array of environments. Among these, volcanic eruptions can exert severe impacts on the dynamic equilibrium of riverine environment. The production and subsequent mobilization of large amounts of sediment all over the river basin, can strongly affect both hydrology and sediment and large wood transport dynamics. The aim of this research is to quantify the impact of a volcanic eruption along the Blanco River basin (Southern Chile), considering the geomorphic settings, the sediment dynamics and wood transport. Moreover, an overview on the possible management strategies to reduce the risks will be proposed. The research was carried out mainly along a 2.2 km-long reach of the fourth-order Blanco stream. Almost the entire river basin was affected by the volcanic eruption, several meters of tephra (up to 8 m) were deposited, affecting the evergreen forest and the fluvial corridor. Field surveys and remote sense analysis were carried out to investigate the effect of such extreme event. A Terrestrial Laser Scanner (TLS) was used to detect the morphological changes by computing Difference of Dems (DoDs), while field surveys were carried out to detect the amount of in-channel wood; moreover aerial photos have been analyzed to detect the extension of the impact of volcanic eruption over the river basin. As expected, the DoDs analysis permitted to detect predominant erosional processes along the channel network. In fact, over 190569 m2 there was erosion that produced about 362999 m3 of sediment mobilized, while the deposition happened just over 58715 m2 for a total amount of 23957 m3. Looking then to the LW recruited and transported downstream, was possible to detect as along the active channel corridor a total amount of 113 m3/ha of wood was present. Moreover, analyzing aerial photographs taken before and after the volcanic eruption was possible to define as a total area of about 2.19 km2 was affected by tephra deposition, 0.87 km2 has already been eroded by floods, while 1.32 km2 is still there. Considering an average depth of 5 m, the potential amount of sediment erodible and potentially transported downstream during the next near future is around 6.5 x 106 m3. Finally, from the same area can be recruited other 7.3 x 104 m3 of LW that can be transported towards the mouth. These results may help to better define management strategies to reduce the potential risks to the sensitive structures and cross section downstream. In fact, the management of sediment and LW transport through the lower Chaiten village appear of fundamental importance to guarantee a safer condition. This research is funded by the Chilean research Project FONDECYT 1141064 "Effects of vegetation on channel morphodynamics: a multiscale investigation in Chilean gravel-bed rivers".

In vitro studies on the stability in the proximal gastrointestinal tract and bioaccessibility in Caco-2 cells of chlorogenic acids from spent coffee grounds.

PubMed

Monente, Carmen; Ludwig, Iziar A; Stalmach, Angelique; de Peña, Maria Paz; Cid, Concepción; Crozier, Alan

2015-01-01

Spent coffee grounds are a potential commercial source of substantial amounts of chlorogenic acids (CGAs). The aim of this study was to evaluate the stability of spent coffee CGAs using in vitro simulated gastroduodenal digestion and to investigate their potential absorption using an in vitro Caco-2 model of human small intestinal epithelium. During in vitro digestion, lactones were partially degraded while caffeoylquinic and feruloylquinic acids were much more stable. Transport and metabolism studies showed that 1% of the total CGAs were absorbed and transported from the apical to the basolateral side of a Caco-2 cell monolayer after 1 h. Lactones and coumaroylquinic acids showed the rate of highest absorption. Caco-2 cells possessed low metabolic activity. In conclusion, spent coffee extracts contain large amounts of CGAs, which remained bioaccessible across the intestinal barrier, albeit to a relatively low degree.

An evaluation of coding methodologies for potential use in the Alabama Resource Information System (ARIS)-transportation study for the state of Alabama

NASA Technical Reports Server (NTRS)

Montgomery, O. L.

1977-01-01

Procedures developed for digitizing the transportation arteries, airports, and dock facilities of Alabama and placing them in a computerized format compatible with the Alabama Resource Information System are described. The time required to digitize by the following methods: (a) manual, (b) Telereadex 29 with film reading and digitizing system, and (c) digitizing tablets was evaluated. A method for digitizing and storing information from the U. T. M. grid cell base which was compatible with the system was developed and tested. The highways, navigable waterways, railroads, airports, and docks in the study area were digitized and the data stored. The manual method of digitizing was shown to be best for small amounts of data, while the graphic input from the digitizing tablets would be the best approach for entering the large amounts of data required for an entire state.

Empirical relations between large wood transport and catchment characteristics

NASA Astrophysics Data System (ADS)

Steeb, Nicolas; Rickenmann, Dieter; Rickli, Christian; Badoux, Alexandre

2017-04-01

The transport of vast amounts of large wood (LW) in water courses can considerably aggravate hazardous situations during flood events, and often strongly affects resulting flood damage. Large wood recruitment and transport are controlled by various factors which are difficult to assess and the prediction of transported LW volumes is difficult. Such information are, however, important for engineers and river managers to adequately dimension retention structures or to identify critical stream cross-sections. In this context, empirical formulas have been developed to estimate the volume of transported LW during a flood event (Rickenmann, 1997; Steeb et al., 2017). The data base of existing empirical wood load equations is, however, limited. The objective of the present study is to test and refine existing empirical equations, and to derive new relationships to reveal trends in wood loading. Data have been collected for flood events with LW occurrence in Swiss catchments of various sizes. This extended data set allows us to derive statistically more significant results. LW volumes were found to be related to catchment and transport characteristics, such as catchment size, forested area, forested stream length, water discharge, sediment load, or Melton ratio. Both the potential wood load and the fraction that is effectively mobilized during a flood event (effective wood load) are estimated. The difference of potential and effective wood load allows us to derive typical reduction coefficients that can be used to refine spatially explicit GIS models for potential LW recruitment.

Fumonisin as a possible contributing factor to neural tube defects in populations consuming large amounts of maize

USDA-ARS?s Scientific Manuscript database

Fumonisin B1 (FB) is an inhibitor of sphingolipid (SL) biosynthesis and folate transport and can induce neural tube defects (NTD) in mice. NTD incidence is high in countries where maize is a dietary staple and FB exposure is likely. In Guatemala the incidence of FB in maize has been well documented ...

Fate of peat-derived carbon and associated CO2 and CO emissions from two Southeast Asian estuaries

NASA Astrophysics Data System (ADS)

Müller, D.; Warneke, T.; Rixen, T.; Müller, M.; Mujahid, A.; Bange, H. W.; Notholt, J.

2015-06-01

Coastal peatlands in Southeast Asia release large amounts of organic carbon to rivers, which transport it further to the adjacent estuaries. However, little is known about the fate of this terrestrial material in the coastal ocean. Although Southeast Asia is, by area, considered a hotspot of estuarine CO2 emissions, studies in this region are very scarce. We measured dissolved and particulate organic carbon, carbon dioxide (CO2) partial pressure and carbon monoxide (CO) concentrations in two tropical estuaries in Sarawak, Malaysia, whose coastal area is covered by peatlands. We surveyed the estuaries of the rivers Lupar and Saribas during the wet and dry season, respectively. The spatial distribution and the carbon-to-nitrogen ratios of dissolved organic matter (DOM) suggest that peat-draining rivers convey terrestrial organic carbon to the estuaries. We found evidence that a large fraction of this carbon is respired. The median pCO2 in the estuaries ranged between 618 and 5064 μatm with little seasonal variation. CO2 fluxes were determined with a floating chamber and estimated to amount to 14-272 mol m-2 yr-1, which is high compared to other studies from tropical and subtropical sites. In contrast, CO concentrations and fluxes were relatively moderate (0.3-1.4 nmol L-1 and 0.8-1.9 mmol m-2 yr-1) if compared to published data for oceanic or upwelling systems. We attributed this to the large amounts of suspended matter (4-5004 mg L-1), limiting the light penetration depth. However, the diurnal variation of CO suggests that it is photochemically produced, implying that photodegradation might play a role for the removal of DOM from the estuary as well. We concluded that unlike smaller peat-draining tributaries, which tend to transport most carbon downstream, estuaries in this region function as an efficient filter for organic carbon and release large amounts of CO2 to the atmosphere. The Lupar and Saribas mid-estuaries release 0.4 ± 0.2 Tg C yr-1, which corresponds to approximately 80% of the emissions from the aquatic systems in these two catchments.

Large wood recruitment and transport during large floods: A review

NASA Astrophysics Data System (ADS)

Comiti, F.; Lucía, A.; Rickenmann, D.

2016-09-01

Large wood (LW) elements transported during large floods are long known to have the capacity to induce dangerous obstructions along the channel network, mostly at bridges and at hydraulic structures such as weirs. However, our current knowledge of wood transport dynamics during high-magnitude flood events is still very scarce, mostly because these are (locally) rare and thus unlikely to be directly monitored. Therefore, post-event surveys are invaluable ways to get insights (although indirectly) on LW recruitment processes, transport distance, and factors inducing LW deposition - all aspects that are crucial for the proper management of river basins related to flood hazard mitigation. This paper presents a review of the (quite limited) literature available on LW transport during large floods, drawing extensively on the authors' own experience in mountain and piedmont rivers, published and unpublished. The overall picture emerging from these studies points to a high, catchment-specific variability in all the different processes affecting LW dynamics during floods. Specifically, in the LW recruitment phase, the relative floodplain (bank erosion) vs. hillslope (landslide and debris flows) contribution in mountain rivers varies substantially, as it relates to the extent of channel widening (which depends on many variables itself) but also to the hillslope-channel connectivity of LW mobilized on the slopes. As to the LW transport phase within the channel network, it appears to be widely characterized by supply-limited conditions; whereby LW transport rates (and thus volumes) are ultimately constrained by the amount of LW that is made available to the flow. Indeed, LW deposition during floods was mostly (in terms of volume) observed at artificial structures (bridges) in all the documented events. This implies that the estimation of LW recruitment and the assessment of clogging probabilities for each structure (for a flood event of given magnitude) are the most important aspects for the prediction of LW transport magnitude at any cross section along the river network. Finally, the review discusses the optimal strategies to manage LW-related hazard, which should consider riparian vegetation and in-channel dead wood as key components of river ecosystems and thus should interfere with LW (as well as with sediment) transport dynamics only for limited spatial and temporal scales.

In vivo quantitative imaging of photoassimilate transport dynamics and allocation in large plants using a commercial positron emission tomography (PET) scanner

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

Karve, Abhijit A.; Alexoff, David; Kim, Dohyun

Although important aspects of whole-plant carbon allocation in crop plants (e.g., to grain) occur late in development when the plants are large, techniques to study carbon transport and allocation processes have not been adapted for large plants. Positron emission tomography (PET), developed for dynamic imaging in medicine, has been applied in plant studies to measure the transport and allocation patterns of carbohydrates, nutrients, and phytohormones labeled with positron-emitting radioisotopes. However, the cost of PET and its limitation to smaller plants has restricted its use in plant biology. Here we describe the adaptation and optimization of a commercial clinical PET scannermore » to measure transport dynamics and allocation patterns of 11C-photoassimilates in large crops. Based on measurements of a phantom, we optimized instrument settings, including use of 3-D mode and attenuation correction to maximize the accuracy of measurements. To demonstrate the utility of PET, we measured 11C-photoassimilate transport and allocation in Sorghum bicolor, an important staple crop, at vegetative and reproductive stages (40 and 70 days after planting; DAP). The 11C-photoassimilate transport speed did not change over the two developmental stages. However, within a stem, transport speeds were reduced across nodes, likely due to higher 11C-photoassimilate unloading in the nodes. Photosynthesis in leaves and the amount of 11C that was exported to the rest of the plant decreased as plants matured. In young plants, exported 11C was allocated mostly (88 %) to the roots and stem, but in flowering plants (70 DAP) the majority of the exported 11C (64 %) was allocated to the apex. Our results show that commercial PET scanners can be used reliably to measure whole-plant C-allocation in large plants nondestructively including, importantly, allocation to roots in soil. This capability revealed extreme changes in carbon allocation in sorghum plants, as they advanced to maturity. Further, our results suggest that nodes may be important control points for photoassimilate distribution in crops of the family Poaceae. In conclusion, quantifying real-time carbon allocation and photoassimilate transport dynamics, as demonstrated here, will be important for functional genomic studies to unravel the mechanisms controlling phloem transport in large crop plants, which will provide crucial insights for improving yields.« less

In vivo quantitative imaging of photoassimilate transport dynamics and allocation in large plants using a commercial positron emission tomography (PET) scanner

DOE PAGES

Karve, Abhijit A.; Alexoff, David; Kim, Dohyun; ...

2015-11-09

Although important aspects of whole-plant carbon allocation in crop plants (e.g., to grain) occur late in development when the plants are large, techniques to study carbon transport and allocation processes have not been adapted for large plants. Positron emission tomography (PET), developed for dynamic imaging in medicine, has been applied in plant studies to measure the transport and allocation patterns of carbohydrates, nutrients, and phytohormones labeled with positron-emitting radioisotopes. However, the cost of PET and its limitation to smaller plants has restricted its use in plant biology. Here we describe the adaptation and optimization of a commercial clinical PET scannermore » to measure transport dynamics and allocation patterns of 11C-photoassimilates in large crops. Based on measurements of a phantom, we optimized instrument settings, including use of 3-D mode and attenuation correction to maximize the accuracy of measurements. To demonstrate the utility of PET, we measured 11C-photoassimilate transport and allocation in Sorghum bicolor, an important staple crop, at vegetative and reproductive stages (40 and 70 days after planting; DAP). The 11C-photoassimilate transport speed did not change over the two developmental stages. However, within a stem, transport speeds were reduced across nodes, likely due to higher 11C-photoassimilate unloading in the nodes. Photosynthesis in leaves and the amount of 11C that was exported to the rest of the plant decreased as plants matured. In young plants, exported 11C was allocated mostly (88 %) to the roots and stem, but in flowering plants (70 DAP) the majority of the exported 11C (64 %) was allocated to the apex. Our results show that commercial PET scanners can be used reliably to measure whole-plant C-allocation in large plants nondestructively including, importantly, allocation to roots in soil. This capability revealed extreme changes in carbon allocation in sorghum plants, as they advanced to maturity. Further, our results suggest that nodes may be important control points for photoassimilate distribution in crops of the family Poaceae. In conclusion, quantifying real-time carbon allocation and photoassimilate transport dynamics, as demonstrated here, will be important for functional genomic studies to unravel the mechanisms controlling phloem transport in large crop plants, which will provide crucial insights for improving yields.« less

Characterization of large-pore polymeric supports for use in perfusion biochromatography.

PubMed

Whitney, D; McCoy, M; Gordon, N; Afeyan, N

1998-05-22

Perfusion chromatography is uniquely characterized by the flow of a portion of the column eluent directly through the resin in the packed bed. The benefits of this phenomenon and some of the properties of perfusive resins have been described before, and can be summarized as enhanced mass transport to interior binding sites. Here we extend the understanding of this phenomenon by comparing resins with different pore size distributions. Resins are chosen to give approximately the same specific pore volumes (as shown in the characterization section) but the varying contribution of large pores is used to control the amount of liquid flowing through the beads. POROS R1 has the largest contribution of throughpores, and therefore the greatest intraparticle flow. POROS R2 has a lower contribution of throughpores, and a higher surface area coming from a greater population of diffusive pores, but still shows significant mass transport enhancements relative to a purely diffusive control. Oligo R3 is dominated by a high population of diffusive pores, and is used comparatively as a non-perfusive resin. Although the pore size distribution can be engineered to control mass transport rates, the resulting surface area is not the only means by which binding capacity can be controlled. Surface coatings are employed to increase binding capacity without fundamentally altering the mass transport properties. Models are used to describe the amount of flow transecting the beads, and comparisons of coated resins to uncoated (polystyrene) resins leads to the conclusion that these coatings do not obstruct the throughpore structures. This is an important conclusion since the binding capacity of the coated product, in some cases, is shown to be over 10-fold higher than the precursor polystyrene scaffold (i.e., POROS R1 or POROS R2).

Investigating the haze transport from 1997 biomass burning in Southeast Asia: its impact upon Singapore

NASA Astrophysics Data System (ADS)

Koe, Lawrence C. C.; Arellano, Avelino F.; McGregor, John L.

The 1997 Indonesia forest fires was an environmental disaster of exceptional proportions. Such a disaster caused massive transboundary air pollution and indiscriminate destruction of biodiversity in the world. The immediate consequence of the fires was the production of large amounts of haze in the region, causing visibility and health problems within Southeast Asia. Furthermore, fires of these magnitudes are potential contributors to global warming and climate change due to the emission of large amounts of greenhouse gases and other pyrogenic products.The long-range transport of fire-related haze in the region is investigated using trajectories from the CSIRO Division of Atmospheric Research Limited Area Model (DARLAM). Emission scenarios were constructed for hotspot areas in Sumatra and Kalimantan for the months of September and October 1997 to determine the period and fire locations most critical to Singapore. This study also examines some transport issues raised from field observations. Results show that fires in the coastal areas of southeast Sumatra and southwest Kalimantan can be potential contributors to transboundary air pollution in Singapore. Singapore was directly affected by haze from these areas whereas Kuala Lumpur was heavily affected by the haze coming from Sumatra. In most cases, Singapore was more affected by fires from Kalimantan than was Kuala Lumpur. This was mainly a result of the shifting of monsoons. The transition of monsoons resulted in weaker low-level winds and shifted convergence zones near to the southeast of Peninsular Malaysia. In addition to severe drought and massive fire activity in 1997, the timing of the monsoon transition has a strong influence on haze transport in the region.

Cobenefits of replacing car trips with alternative transportation: a review of evidence and methodological issues.

PubMed

Xia, Ting; Zhang, Ying; Crabb, Shona; Shah, Pushan

2013-01-01

It has been reported that motor vehicle emissions contribute nearly a quarter of world energy-related greenhouse gases and cause nonnegligible air pollution primarily in urban areas. Reducing car use and increasing ecofriendly alternative transport, such as public and active transport, are efficient approaches to mitigate harmful environmental impacts caused by a large amount of vehicle use. Besides the environmental benefits of promoting alternative transport, it can also induce other health and economic benefits. At present, a number of studies have been conducted to evaluate cobenefits from greenhouse gas mitigation policies. However, relatively few have focused specifically on the transport sector. A comprehensive understanding of the multiple benefits of alternative transport could assist with policy making in the areas of transport, health, and environment. However, there is no straightforward method which could estimate cobenefits effect at one time. In this paper, the links between vehicle emissions and air quality, as well as the health and economic benefits from alternative transport use, are considered, and methodological issues relating to the modelling of these cobenefits are discussed.

Transport of large breakdown products of dietary protein through the gut wall.

PubMed Central

Hemmings, W A; Williams, E W

1978-01-01

Ferritin or tritium labelled immunoglobulin G may, by electron microscopy, be demonstrated entering, within, and leaving the epithelial cells. Quantitative studies using various proteins labelled with radioiodine show that large amounts of protein bound radioactivity may be demonstrated in the tissues after feeding the labelled protein to adult rats by stomach tube. The molecular size of this material as determined by sugar gradient ultracentrifugation of tissue extracts ranges when IgG is fed from 50,000-20,000 Daltons. The material retains its ability to react as antigen with antisera specific to the original molecule: precipitation reactions may be obtained in gels and quantitative studies show that cnosiderable amounts of the protein-bound radioactivity are still specifically precipitable. Such studies have been carried out with alpha-gliadin as well as bovine IgG. At 100 days old rats may absorb as much as 40% of a dose of bovine IgG in the form of these large molecular breakdown products. PMID:680603

Investigating the effects of transport on the preservation of soft-bodied organisms using an annular flume tank.

NASA Astrophysics Data System (ADS)

Bath Enright, Orla; Minter, Nicholas; Sumner, Esther; Mángano, Gabriela; Buatois, Luis

2016-04-01

Annular flume tank experiments offer unique opportunities to be able to investigate the effect of transport on a range of organisms; being able to create slow to fast sediment-laden flows that can be laminar to fully turbulent, and lasting over durations of minutes to hours. Understanding the effects of transport on the preservation potential of different organisms is fundamental to the study of palaeoecology. Despite this, the sedimentological processes leading up to fossil entombment remain largely overlooked. This is especially significant for fossil lagerstätte such as the Burgess Shale, whose exquisite fossil preservation has enabled insights into the anatomy of early soft-bodied organisms and their evolution during the Cambrian explosion. However there is still a fundamental debate with regards to the transport these organisms have undergone. Namely, whether they were living within or close to the environment of deposition, or could they have been transported from one environment to another? As such, does the Burgess Shale biota represent a palaeocommunity or not? To explore the limits of the effect of transport, initial experiments have been designed using an annular flume tank in order to test the influence of fully turbulent sandy suspensions (75-250μm) on organism preservation. This is a three factorial design where the three independent variables are transport duration, sediment concentration and grain angularity. In all experiments, flow velocity was kept constant along with controls on pH and salinity. The dependent variable, an index of "increasing state of damage" has been devised to classify the amount of destruction each organism exhibits after the experimental procedure. Results are presented here. From observations such as these, we can begin to set constraints on the amount of transport, if any, that these fossil organisms could have endured.

Sediment budget analysis from Landslide debris and river channel change during the extreme event - example of Typhoon Morakot at Laonong river, Taiwan

NASA Astrophysics Data System (ADS)

Chang, Kuo-Jen; Huang, Yu-Ting; Huang, Mei-Jen; Chiang, Yi-Lin; Yeh, En-Chao; Chao, Yu-Jui

2014-05-01

Taiwan, due to the high seismicity and high annual rainfall, numerous landslides triggered every year and severe impacts affect the island. Typhoon Morakot brought extreme and long-time rainfall for Taiwan in August 2009. It further caused huge loss of life and property in central and southern Taiwan. Laonong River is the largest tributary of Gaoping River. It's length is 137 km, and the basin area is 1373 km2. More than 2000mm rainfall brought and maximum rainfall exceeded 100mm/hr in the region by Typhoon Morakot in Aug, 2009. Its heavy rains made many landslides and debris flew into the river and further brought out accumulation and erosion on river banks of different areas. It caused severe disasters within the Laonong River drainage. In the past, the study of sediment blockage of river channel usually relies on field investigation, but due to inconvenient transportation, topographical barriers, or located in remote areas, etc. the survey is hardly to be completed sometimes. In recent years, the rapid development of remote sensing technology improves image resolution and quality significantly. Remote sensing technology can provide a wide range of image data, and provide essential and precious information. Furthermore, although the amount of sediment transportation can be estimated by using data such as rainfall, river flux, and suspended loads, the situation of large debris migration cannot be studied via those data. However, landslides, debris flow and river sediment transportation model in catchment area can be evaluated easily through analyzing the digital terrain model (DTM) . The purpose of this study is to investigate the phenomenon of river migration and to evaluate the amount of migration along Laonong River by analyzing the DEM before and after the typhoon Morakot. The DEMs are built by using the aerial images taken by digital mapping camera (DMC) and by airborne digital scanner 40 (ADS 40) before and after typhoon event. The results show that lateral erosion of the Laonong River caused by the typhoon seriously, especially in Yushan National Park, and midstream region. However, lateral erosion in downstream region is not so obvious. Meanwhile the siltation depth resulted from the Typhoon Morakot is larger in upstream region than in midstream and downstream regions. The amount of landslide debris created by Typhoon Morakot was too excessive to be transported. Materials just siltated in the upstream in place, same as in the middle stream area. Because of the amount of river slope erosion and sediment collapse in the downstream region is less than in upstream and midstream region, the amount of river erosion slightly larger than the amount of river siltation. The goals of this project are trying to decipher the sliding process and morphologic changes of large landslide areas, sediment transport and budgets, and to investigate the phenomenon of river migration. The results of this study provides not only geomatics and GIS dataset of the hazards, but also for essential geomorphologic information for other study, and for hazard mitigation and planning, as well.

Amazon River carbon dioxide outgassing fuelled by wetlands.

PubMed

Abril, Gwenaël; Martinez, Jean-Michel; Artigas, L Felipe; Moreira-Turcq, Patricia; Benedetti, Marc F; Vidal, Luciana; Meziane, Tarik; Kim, Jung-Hyun; Bernardes, Marcelo C; Savoye, Nicolas; Deborde, Jonathan; Souza, Edivaldo Lima; Albéric, Patrick; Landim de Souza, Marcelo F; Roland, Fabio

2014-01-16

River systems connect the terrestrial biosphere, the atmosphere and the ocean in the global carbon cycle. A recent estimate suggests that up to 3 petagrams of carbon per year could be emitted as carbon dioxide (CO2) from global inland waters, offsetting the carbon uptake by terrestrial ecosystems. It is generally assumed that inland waters emit carbon that has been previously fixed upstream by land plant photosynthesis, then transferred to soils, and subsequently transported downstream in run-off. But at the scale of entire drainage basins, the lateral carbon fluxes carried by small rivers upstream do not account for all of the CO2 emitted from inundated areas downstream. Three-quarters of the world's flooded land consists of temporary wetlands, but the contribution of these productive ecosystems to the inland water carbon budget has been largely overlooked. Here we show that wetlands pump large amounts of atmospheric CO2 into river waters in the floodplains of the central Amazon. Flooded forests and floating vegetation export large amounts of carbon to river waters and the dissolved CO2 can be transported dozens to hundreds of kilometres downstream before being emitted. We estimate that Amazonian wetlands export half of their gross primary production to river waters as dissolved CO2 and organic carbon, compared with only a few per cent of gross primary production exported in upland (not flooded) ecosystems. Moreover, we suggest that wetland carbon export is potentially large enough to account for at least the 0.21 petagrams of carbon emitted per year as CO2 from the central Amazon River and its floodplains. Global carbon budgets should explicitly address temporary or vegetated flooded areas, because these ecosystems combine high aerial primary production with large, fast carbon export, potentially supporting a substantial fraction of CO2 evasion from inland waters.

Assessment of Large Wood budget in the gravel-bed Piave River: first attempt

NASA Astrophysics Data System (ADS)

Tonon, Alessia; Picco, Lorenzo; Ravazzolo, Diego; Aristide Lenzi, Mario

2015-04-01

During the last decades, the dynamics of large wood (LW) in rivers were analyzed to consider and define the LW budget. The space-time variations of LW amount results from the differences among input (e.g. fluvial transport, lateral recruitment) and output (e.g. fluvial transport, overbank deposition, natural chronic dead) of LW along a riverine environment. Different methodologies were applied in several fluvial environments, however in large river systems characterized by complex LW dynamics, the processes are still poor quantified. Aim of this contribution is to perform a LW budget estimation over the short period, assessing the effect of an over bankfull flood (Q=1039 m3 s-1; R.I=3.5 years). The research was carried out along a 1 km-long reach (around 15 ha) located into the middle course of the large gravel-bed Piave River (North East of Italy). The LW budget has been defined considering the recruitment through bank erosion and the fluvial transport of LW into and out of the study reach. The former factor was achieved integrating field data on riparian vegetation with the monitoring of riverbanks with a Differential Global Positioning System (DGPS). The latter was obtained detecting all LW elements (diameter ≥ 0.10 m and/or length ≥ 1 m) stored along the study reach, before and after the flood. For each LW the GPS position was recorded and a numbered tag was installed with the addition of colored paint to permit a rapid post-event recovery. Preliminary results indicate that, along the study area, the floating transport of LW is one of the most significant processes able to modify the amount of LW deposited along a riverine system. In fact, considering the input of LW, the 99.4 % (102 m3 km-1) comes from upstream due to floating, whereas the 0.6% (0.17 m3 km-1) was recruited through bank erosion. Analyzing the output, 94.3% (40.26 m3 km-1) of LW was transported downstream of the study area, whereas only the 5.7 % (2.43 m3 km-1) of LW was involved in the "internal displacement". In this study, the amount of LW increased of about 60.29% in the number of LW elements and 145% in volume, corresponding to 61.98 m3 km-1. The methodology here presented appears an easy and economical way to assess LW budget at a small spatial scale. However, further improvements are needed to allow the construction of comprehensive LW budget, considering also the loss of LW from overbank deposition as from natural decay. This research is funded within both, the University of Padova Research Project CPDA149091- "WoodAlp: linking large Wood and morphological dynamics of gravel bed rivers of Eastern Italian Alps"- 2014-16 and the Project "SedAlp: sediment management in Alpine basins, integrating sediment continuum, risk mitigation and hydropower", 83-4-3-AT, in the framework of the European Territorial Cooperation Program "Alpine Space" 2007-13.

Data Compression Techniques for Advanced Space Transportation Systems

NASA Technical Reports Server (NTRS)

Bradley, William G.

1998-01-01

Advanced space transportation systems, including vehicle state of health systems, will produce large amounts of data which must be stored on board the vehicle and or transmitted to the ground and stored. The cost of storage or transmission of the data could be reduced if the number of bits required to represent the data is reduced by the use of data compression techniques. Most of the work done in this study was rather generic and could apply to many data compression systems, but the first application area to be considered was launch vehicle state of health telemetry systems. Both lossless and lossy compression techniques were considered in this study.

Generalized Fokker-Planck theory for electron and photon transport in biological tissues: application to radiotherapy.

PubMed

Olbrant, Edgar; Frank, Martin

2010-12-01

In this paper, we study a deterministic method for particle transport in biological tissues. The method is specifically developed for dose calculations in cancer therapy and for radiological imaging. Generalized Fokker-Planck (GFP) theory [Leakeas and Larsen, Nucl. Sci. Eng. 137 (2001), pp. 236-250] has been developed to improve the Fokker-Planck (FP) equation in cases where scattering is forward-peaked and where there is a sufficient amount of large-angle scattering. We compare grid-based numerical solutions to FP and GFP in realistic medical applications. First, electron dose calculations in heterogeneous parts of the human body are performed. Therefore, accurate electron scattering cross sections are included and their incorporation into our model is extensively described. Second, we solve GFP approximations of the radiative transport equation to investigate reflectance and transmittance of light in biological tissues. All results are compared with either Monte Carlo or discrete-ordinates transport solutions.

Glycogen synthase kinase 3 phosphorylates kinesin light chains and negatively regulates kinesin-based motility

NASA Technical Reports Server (NTRS)

Morfini, Gerardo; Szebenyi, Gyorgyi; Elluru, Ravindhra; Ratner, Nancy; Brady, Scott T.

2002-01-01

Membrane-bounded organelles (MBOs) are delivered to different domains in neurons by fast axonal transport. The importance of kinesin for fast antero grade transport is well established, but mechanisms for regulating kinesin-based motility are largely unknown. In this report, we provide biochemical and in vivo evidence that kinesin light chains (KLCs) interact with and are in vivo substrates for glycogen synthase kinase 3 (GSK3). Active GSK3 inhibited anterograde, but not retrograde, transport in squid axoplasm and reduced the amount of kinesin bound to MBOs. Kinesin microtubule binding and microtubule-stimulated ATPase activities were unaffected by GSK3 phosphorylation of KLCs. Active GSK3 was also localized preferentially to regions known to be sites of membrane delivery. These data suggest that GSK3 can regulate fast anterograde axonal transport and targeting of cargos to specific subcellular domains in neurons.

Modeling transport and deposition of the Mekong River sediment

USGS Publications Warehouse

Xue, Zuo; He, Ruoying; Liu, J. Paul; Warner, John C.

2012-01-01

A Coupled Wave–Ocean–SedimentTransport Model was used to hindcast coastal circulation and fine sedimenttransport on the Mekong shelf in southeastern Asian in 2005. Comparisons with limited observations showed that the model simulation captured the regional patterns and temporal variability of surface wave, sea level, and suspended sediment concentration reasonably well. Significant seasonality in sedimenttransport was revealed. In summer, a large amount of fluvial sediments was delivered and deposited near the MekongRiver mouth. In the following winter, strong ocean mixing, and coastal current lead to resuspension and southwestward dispersal of a small fraction of previously deposited sediments. Model sensitivity experiments (with reduced physics) were performed to investigate the impact of tides, waves, and remotely forced ambient currents on the transport and dispersal of the fluvial sediment. Strong wave mixing and downwelling-favorable coastal current associated with the more energetic northeast monsoon in the winter season are the main factors controlling the southwestward along-shelf transport.

The role of suspension events in cross-shore and longshore suspended sediment transport in the surf zone

USGS Publications Warehouse

Jaffe, Bruce E.

2015-01-01

Suspension of sand in the surf zone is intermittent. Especially striking in a time series of concentration are periods of intense suspension, suspension events, when the water column suspended sediment concentration is an order of magnitude greater than the mean concentration. The prevalence, timing, and contribution of suspension events to cross-shore and longshore suspended sediment transport are explored using field data collected in the inner half of the surf zone during a large storm at Duck, NC. Suspension events are defined as periods when the concentration is above a threshold. Events tended to occur during onshore flow under the wave crest, resulting in an onshore contribution to the suspended sediment transport. Even though large events occurred less than 10 percent of the total time, at some locations onshore transport associated with suspension events was greater than mean-current driven offshore-directed transport during non-event periods, causing the net suspended sediment transport to be onshore. Events and fluctuations in longshore velocity were not correlated. However, events did increase the longshore suspended sediment transport by approximately the amount they increase the mean concentration, which can be up to 35%. Because of the lack of correlation, the longshore suspended sediment transport can be modeled without considering the details of the intensity and time of events as the vertical integration of the product of the time-averaged longshore velocity and an event-augmented time-averaged concentration. However, to accurately model cross-shore suspended sediment transport, the timing and intensity of suspension events must be reproduced.

Numerical modeling of sediment transport and its effect on algal biomass distribution in Lake Pontchartrain due to flood release from Bonnet Carré Spillway

USDA-ARS?s Scientific Manuscript database

In order to protect the city of New Orleans from the Mississippi River flooding, the Bonnet Carré Spillway (BCS) was constructed from 1929 to 1936 to divert flood water from the river into Lake Pontchartrain and then into the Gulf of Mexico. During the BCS opening for flood release, large amount of ...

Carbon dioxide efficiency of terrestrial enhanced weathering.

PubMed

Moosdorf, Nils; Renforth, Phil; Hartmann, Jens

2014-05-06

Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimistic scenarios. The results show that the choice of source rocks and material comminution technique dominate the CO2 efficiency of enhanced weathering. CO2 emissions from transport amount to on average 0.5-3% of potentially sequestered CO2. The emissions of material mining and application are negligible. After accounting for all emissions, 0.5-1.0 t CO2 can be sequestered on average per tonne of rock, translating into a unit cost from 1.6 to 9.9 GJ per tonne CO2 sequestered by enhanced weathering. However, to control or reduce atmospheric CO2 concentrations substantially with enhanced weathering would require very large amounts of rock. Before enhanced weathering could be applied on large scales, more research is needed to assess weathering rates, potential side effects, social acceptability, and mechanisms of governance.

Vertical Structure of Heat and Momentum Transport in the Urban Surface Layer

NASA Astrophysics Data System (ADS)

Hrisko, J.; Ramamurthy, P.

2017-12-01

Vertical transport of heat and momentum during convective periods is investigated in the urban surface layer using eddy covariance measurements at 5 levels. The Obukhov length is used to divide the dataset into distinct stability regimes: weakly unstable, unstable and very unstable. Our preliminary analysis indicates critical differences in the transport of heat and momentum as the instability increases. Particularly, during periods of increased instability the vertical heat flux deviates from surface layer similarity theory. Further analysis of primary quadrant sweeps and ejections also indicate deviations from the theory, alluding that ejections dominate during convective periods for heat transport, but equally contribute with sweeps for momentum transport. The transport efficiencies of momentum at all 5 levels uniformly decreases as the instability increases, in stark contrast the heat transport efficiencies increase non-linearly as the instability increases. Collectively, these results demonstrate the breakdown of similarity theory during convective periods, and reaffirm that revised and improved methods for characterizing heat and momentum transport in urban areas is needed. These implications could ultimately advance weather prediction and estimation of scalar transport for urban areas susceptible to weather hazards and large amounts of pollution.

Cadmium uptake, accumulation, and remobilization in iron plaque and rice tissues at different growth stages.

PubMed

Zhou, Hang; Zhu, Wei; Yang, Wen-Tao; Gu, Jiao-Feng; Gao, Zi-Xiang; Chen, Li-Wei; Du, Wen-Qi; Zhang, Ping; Peng, Pei-Qin; Liao, Bo-Han

2018-05-15

Rice consumption is considered the main source of human dietary Cd intake in Southeast Asia. This study aimed to investigate Cd uptake, accumulation, and remobilization in iron plaque and rice (Oryza sativa L. cv. 'Xiangwanxian 12') tissues at different growth stages. A pot experiment was performed in two Cd-contaminated paddy soils. Cd concentrations in iron plaque and rice tissues at five different growth stages (tillering, booting, milky, dough, and maturing) were measured. Cd concentrations in iron plaque and rice tissues (roots, stems, leaves, spikelet, husks, and brown rice) varied with growth stage. Cd accumulation in rice plants increased with extending growth in both soils, reaching 15.3 and 35.4μg/pot, respectively, at the maturing stage. The amounts of Cd in brown rice increased from the milky to maturing stages, with the greatest percentage uptake during the maturing stage. Cd amount in iron plaque significantly affected the uptake and accumulation of Cd in roots and aerial parts of rice plants. Accumulated Cd in leaves was remobilized and transported during the booting to maturing stages, and the contributions of Cd transportation from leaves to brown rice were 30.0% and 22.5% in the two soils, respectively. A large amount of Cd accumulated in brown rice during the maturing stage. The transportation of remobilized Cd from leaves was also important for the accumulation of Cd in brown rice. Copyright © 2018 Elsevier Inc. All rights reserved.

A road damage and life-cycle greenhouse gas comparison of trucking and pipeline water delivery systems for hydraulically fractured oil and gas field development in Colorado

PubMed Central

Duthu, Ray C.

2017-01-01

The process of hydraulic fracturing for recovery of oil and natural gas uses large amounts of fresh water and produces a comparable amount of wastewater, much of which is typically transported by truck. Truck transport of water is an expensive and energy-intensive process with significant external costs including roads damages, and pollution. The integrated development plan (IDP) is the industry nomenclature for an integrated oil and gas infrastructure system incorporating pipeline-based transport of water and wastewater, centralized water treatment, and high rates of wastewater recycling. These IDP have been proposed as an alternative to truck transport systems so as to mitigate many of the economic and environmental problems associated with natural gas production, but the economic and environmental performance of these systems have not been analyzed to date. This study presents a quantification of lifecycle greenhouse gas (GHG) emissions and road damages of a generic oil and gas field, and of an oil and gas development sited in the Denver-Julesburg basin in the northern Colorado region of the US. Results demonstrate that a reduction in economic and environmental externalities can be derived from the development of these IDP-based pipeline water transportation systems. IDPs have marginal utility in reducing GHG emissions and road damage when they are used to replace in-field water transport, but can reduce GHG emissions and road damage by factors of as much as 6 and 7 respectively, when used to replace fresh water transport and waste-disposal routes for exemplar Northern Colorado oil and gas fields. PMID:28686682

A road damage and life-cycle greenhouse gas comparison of trucking and pipeline water delivery systems for hydraulically fractured oil and gas field development in Colorado.

PubMed

Duthu, Ray C; Bradley, Thomas H

2017-01-01

The process of hydraulic fracturing for recovery of oil and natural gas uses large amounts of fresh water and produces a comparable amount of wastewater, much of which is typically transported by truck. Truck transport of water is an expensive and energy-intensive process with significant external costs including roads damages, and pollution. The integrated development plan (IDP) is the industry nomenclature for an integrated oil and gas infrastructure system incorporating pipeline-based transport of water and wastewater, centralized water treatment, and high rates of wastewater recycling. These IDP have been proposed as an alternative to truck transport systems so as to mitigate many of the economic and environmental problems associated with natural gas production, but the economic and environmental performance of these systems have not been analyzed to date. This study presents a quantification of lifecycle greenhouse gas (GHG) emissions and road damages of a generic oil and gas field, and of an oil and gas development sited in the Denver-Julesburg basin in the northern Colorado region of the US. Results demonstrate that a reduction in economic and environmental externalities can be derived from the development of these IDP-based pipeline water transportation systems. IDPs have marginal utility in reducing GHG emissions and road damage when they are used to replace in-field water transport, but can reduce GHG emissions and road damage by factors of as much as 6 and 7 respectively, when used to replace fresh water transport and waste-disposal routes for exemplar Northern Colorado oil and gas fields.

Parallelization and visual analysis of multidimensional fields: Application to ozone production, destruction, and transport in three dimensions

NASA Technical Reports Server (NTRS)

Schwan, Karsten

1994-01-01

Atmospheric modeling is a grand challenge problem for several reasons, including its inordinate computational requirements and its generation of large amounts of data concurrent with its use of very large data sets derived from measurement instruments like satellites. In addition, atmospheric models are typically run several times, on new data sets or to reprocess existing data sets, to investigate or reinvestigate specific chemical or physical processes occurring in the earth's atmosphere, to understand model fidelity with respect to observational data, or simply to experiment with specific model parameters or components.

Mantle plumes and continental tectonics.

PubMed

Hill, R I; Campbell, I H; Davies, G F; Griffiths, R W

1992-04-10

Mantle plumes and plate tectonics, the result of two distinct modes of convection within the Earth, operate largely independently. Although plumes are secondary in terms of heat transport, they have probably played an important role in continental geology. A new plume starts with a large spherical head that can cause uplift and flood basalt volcanism, and may be responsible for regional-scale metamorphism or crustal melting and varying amounts of crustal extension. Plume heads are followed by narrow tails that give rise to the familiar hot-spot tracks. The cumulative effect of processes associated with tail volcanism may also significantly affect continental crust.

Multi-objective model of waste transportation management for crude palm oil industry

NASA Astrophysics Data System (ADS)

Silalahi, Meslin; Mawengkang, Herman; Irsa Syahputri, Nenna

2018-02-01

The crude palm oil industry is an agro-industrial commodity. The global market of this industry has experienced rapid growth in recent years, such that it has a strategic value to be developed for Indonesian economy. Despite these economic benefits there are a number of environmental problems at the factories, such as high water consumption, the generation of a large amount of wastewater with a high organic content, and the generation of a large quantity of solid wastes and air pollution. In terms of waste transportation, we propose a multiobjective programming model for managing business environmental risk in a crude palm oil manufacture which gives the best possible configuration of waste management facilities and allocates wastes to these facilities. Then we develop an interactive approach for tackling logistics and environmental risk production planning problem for the crude palm oil industry.

Characterization of the transport properties of channel delta-doped structures by light-modulated Shubnikov-de Haas measurements

NASA Technical Reports Server (NTRS)

Mena, R. A.; Schacham, S. E.; Haugland, E. J.; Alterovitz, S. A.; Young, P. G.; Bibyk, S. B.; Ringel, S. A.

1995-01-01

The transport properties of channel delta-doped quantum well structures were characterized by conventional Hall effect and light-modulated Shubnikov-de Haas (SdH) effect measurements. The large number of carriers that become available due to the delta-doping of the channel, leads to an apparent degeneracy in the well. As a result of this degeneracy, the carrier mobility remains constant as a function of temperature from 300 K down to 1.4 K. The large amount of impurity scattering, associated with the overlap of the charge carriers and the dopants, resulted in low carrier mobilities and restricted the observation of the oscillatory magneto-resistance used to characterize the two-dimensional electron gas (2DEG) by conventional SdH measurements. By light-modulating the carriers, we were able to observe the SdH oscillation at low magnetic fields, below 1.4 tesla, and derive a value for the quantum scattering time. Our results for the ratio of the transport and quantum scattering times are lower than those previously measured for similar structures using much higher magnetic fields.

K+ transport and membrane potentials in isolated rat parotid acini

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

Nauntofte, B.; Dissing, S.

1988-10-01

42K+ transport properties of isolated rat parotid acini were characterized concomitant with measurements of membrane potentials (Em) by means of the fluorescent dye diSC3-(5). In unstimulated acini suspended in a 5 mM K+ buffer, Em was governed by the K+ and Cl- gradients and amounted to about -59 mV, a value that remained unaffected on cholinergic stimulation. In unstimulated acini, 42K+ influx was largely mediated by the Na+-K+ pump, and the residual influxes were mediated by a bumetanide-sensitive component (cotransport system) and by K+ channels. Efflux of 42K+ was largely mediated by a bumetanide-sensitive component and by K+ channels. Inmore » the unstimulated state, the cotransport system was mediating K+-K+ exchange without contributing to the net uptake of K+. Within 10 s after stimulation, a approximately 10-fold increase in the acinar K+ conductance (gK) occurred, resulting in a rapid net efflux of K+ that amounted to approximately 3.8 mmol.l cells-1.s-1. Measurements of 42K+ fluxes as a function of the external K+ concentration revealed that in the stimulated state gK increases when external K+ is raised from 0.7 to 10 mM, consistent with an activation of acinar gK by the binding of external K+ to the channel. 42K+ flux ratios as well as the effect of the K+ channel inhibitor from scorpion venom (LQV) suggest that approximately 90% of K+ transport in the stimulated state is mediated by ''maxi'' K+ channels.« less

Corrosion of Pipeline and Wellbore Steel by Liquid CO2 Containing Trace Amounts of Water and SO2

NASA Astrophysics Data System (ADS)

McGrail, P.; Schaef, H. T.; Owen, A. T.

2009-12-01

Carbon dioxide capture and storage in deep saline formations is currently considered the most attractive option to reduce greenhouse gas emissions with continued use of fossil fuels for energy production. Transporting captured CO2 and injection into suitable formations for storage will necessarily involve pipeline systems and wellbores constructed of carbon steels. Industry standards currently require nearly complete dehydration of liquid CO2 to reduce corrosion in the pipeline transport system. However, it may be possible to establish a corrosion threshold based on H2O content in the CO2 that could allow for minor amounts of H2O to remain in the liquid CO2 and thereby eliminate a costly dehydration step. Similarly, trace amounts of sulfur and nitrogen compounds common in flue gas streams are currently removed through expensive desulfurization and catalytic reduction processes. Provided these contaminants could be safely and permanently transported and stored in the geologic reservoir, retrofits of existing fossil-fuel plants could address comprehensive emissions reductions, including CO2 at perhaps nearly the same capital and operating cost. Because CO2-SO2 mixtures have never been commercially transported or injected, both experimental and theoretical work is needed to understand corrosion mechanisms of various steels in these gas mixtures containing varying amounts of water. Experiments were conducted with common tool steel (AISI-01) and pipeline steel (X65) immersed in liquid CO2 at room temperature containing ~1% SO2 and varying amounts of H2O (0 to 2500 ppmw). A threshold concentration of H2O in the liquid CO2-SO2 mixture was established based on the absence of visible surface corrosion. For example, experiments exposing steel to liquid CO2-SO2 containing ~300 ppmw H2O showed a delay in onset of visible corrosion products and minimal surface corrosion was visible after five days of testing. However increasing the water content to 760 ppmw produced extensive surface corrosion after 48 hours at room temperature. Surface characterization by SEM showed one type of morphology that included large circular features radiating outward from a central structure. Chemical analyses obtained by SEM-EDX indicate the phases contained mostly Fe and S with minor amounts of Mn. Corrosion products completely covering the metal coupon surface were identified by XRD as iron sulfite hydrate (FeSO3●3H2O), with lesser amounts of gravegliaite (MnSO3●3H2O), and rozenite (Fe(SO4)●(H2O)4).

A critical evaluation of phosphate retardation and leaching in Hapludults

NASA Astrophysics Data System (ADS)

Dao, Thanh

2016-04-01

Nutrients used in production agriculture, in particular bioactive phosphorus (P), continue to present challenges in trying to reverse the degradation of fragile aquatic ecosystems. Soils treated with large amounts of nutrient-enriched animal manure have elevated P levels in regions of intensive animal agriculture and the residual effects of past large P additions were found to be long-lived. Mathematical models are increasingly used in the evaluation and development of mitigation strategies and sustainable management practices. A large number of predictive tools are currently used in the U.S. for simulating phosphorus environmental fate, including models such AGNPS (Agricultural Non-Point Source), FHANTM Field Hydrologic And Nutrient Transport Model (Field Hydrologic And Nutrient Transport Model), SWAT (Soil & Water Assessment Tool), or APEX (Agric. Policy/Environmental EXtender). The P routines in these models have had limited changes in spite of the advances in our understanding of speciation and transport of various P forms in soil and water systems that have occurred over the last three decades. We conducted soil sorption isotherm experiments that yielded basic information for estimating the Phosphorus Sorption coefficient (PSP) a key parameter used to allocate mineral P into soil labile, active, and stable pools. We compare these coefficients to parameters derived from breakthrough curves (BTC) for determining the extent of retardation and transport of phosphate supplied as KH2PO4 under a constant hydraulic head. Sigmoidal and multi-reaction rate models were observed in the BTCs of the anion, which undermine the rationale for using an overall simple partition coefficient to describe the transport and dispersal of phosphate in soil. Minimizing such generalities used in estimating nutrient availability and transport gives a more accurate picture of status of P in soil to conserve nutrients and minimize loss of excess P inputs to the environment.

Design Enhancements to Facilitate a Sustainable and Energy Efficient Dining Facility (DFAC) in a Contingency Environment

DTIC Science & Technology

2014-09-01

resources, and generate large amounts of food and solid waste daily. Almost all Contingency Basecamp (CB) DFACs provide individual paper and plastic ware...which is costly in terms of purchase, transportation, and disposal. This work analyzed the effects of replacing paper and plastic ware with...reusable materials, and of adding industrial dishwashers to re- duce the logistical burden of using paper and plastic ware. Additional en- hancements

Safe harbor: protecting ports with shipboard fuel cells.

PubMed

Taylor, David A

2006-04-01

With five of the largest harbors in the United States, California is beginning to take steps to manage the large amounts of pollution generated by these bustling centers of transport and commerce. One option for reducing diesel emissions is the use of fuel cells, which run cleaner than diesel and other internal combustion engines. Other technologies being explored by harbor officials are diesel-electric hybrid and gas turbine locomotives for moving freight within port complexes.

Matrix Determination of Reflectance of Hidden Object via Indirect Photography

DTIC Science & Technology

2012-03-01

the hidden object. This thesis provides an alternative method of processing the camera images by modeling the system as a set of transport and...Distribution Function ( BRDF ). Figure 1. Indirect photography with camera field of view dictated by point of illumination. 3 1.3 Research Focus In an...would need to be modeled using radiometric principles. A large amount of the improvement in this process was due to the use of a blind

Evaluation of Iodine Bioavailability in Seaweed Using in Vitro Methods.

PubMed

Domínguez-González, M Raquel; Chiocchetti, Gabriela M; Herbello-Hermelo, Paloma; Vélez, Dinoraz; Devesa, Vicenta; Bermejo-Barrera, Pilar

2017-09-27

Due to the high levels of iodine present in seaweed, the ingestion of a large amount of this type of food can produce excessive intake of iodine. However, the food after ingestion undergoes different chemistry and physical processes that can modify the amount of iodine that reaches the systemic circulation (bioavailability). Studies on the bioavailability of iodine from food are scarce and indicate that the bioavailable amount is generally lower than ingested. Iodine in vitro bioavailability estimation from different commercialized seaweed has been studied using different in vitro approaches (solubility, dialyzability, and transport and uptake by intestinal cells). Results indicate that iodine is available after gastrointestinal digestion for absorption (bioaccessibility: 49-82%), kombu being the seaweed with the highest bioaccessibility. The incorporation of dialysis cell cultures to elucidate bioavailability modifies the estimation of the amount of iodine that may reach the systemic circulation (dialysis, 5-28%; cell culture, ≤3%). The paper discusses advantages and drawbacks of these methodologies for iodine bioavailability in seaweed.

Cation-Inhibited Transport of Graphene Oxide Nanomaterials in Saturated Porous Media: The Hofmeister Effects.

PubMed

Xia, Tianjiao; Qi, Yu; Liu, Jing; Qi, Zhichong; Chen, Wei; Wiesner, Mark R

2017-01-17

Transport of negatively charged nanoparticles in porous media is largely affected by cations. To date, little is known about how cations of the same valence may affect nanoparticle transport differently. We observed that the effects of cations on the transport of graphene oxide (GO) and sulfide-reduced GO (RGO) in saturated quartz sand obeyed the Hofmeister series; that is, transport-inhibition effects of alkali metal ions followed the order of Na + < K + < Cs + , and those of alkaline earth metal ions followed the order of Mg 2+ < Ca 2+ < Ba 2+ . With batch adsorption experiments and microscopic data, we verified that cations having large ionic radii (and thus being weakly hydrated) interacted with quartz sand and GO and RGO more strongly than did cations of small ionic radii. In particular, the monovalent Cs + and divalent Ca 2+ and Ba 2+ , which can form inner-sphere complexes, resulted in very significant deposition of GO and RGO via cation bridging between quartz sand and GO and RGO, and possibly via enhanced straining, due to the enhanced aggregation of GO and RGO from cation bridging. The existence of the Hofmeister effects was further corroborated with the interesting observation that cation bridging was more significant for RGO, which contained greater amounts of carboxyl and phenolic groups (i.e., metal-complexing moieties) than did GO. The findings further demonstrate that transport of nanoparticles is controlled by the complex interplay between nanoparticle surface functionalities and solution chemistry constituents.

Understanding the Transport of Patagonian Dust and Its Influence on Marine Biological Activity in the South Atlantic Ocean

NASA Technical Reports Server (NTRS)

Johnson, Matthew; Meskhidze, Nicholas; Kiliyanpilakkil, Praju; Gasso, Santiago

2010-01-01

Modeling and remote sensing techniques were applied to examine the horizontal and vertical transport pathways of Patagonian dust and quantify the effect of soluble-iron- laden mineral dust deposition on marine primary productivity in the South Atlantic Ocean (SAO) surface waters. The global chemistry transport model GEOS-Chem, implemented with an iron dissolution scheme, was applied to evaluate the atmospheric transport and deposition of mineral dust and bioavailable iron during two dust outbreaks originating in the source regions of Patagonia. In addition to this "rapidly released" iron, offline calculations were also carried out to estimate the amount of bioavailable iron leached during the residence time of dust in the ocean mixed layer. Model simulations showed that the horizontal and vertical transport pathways of Patagonian dust plumes were largely influenced by the synoptic meteorological patterns of high and low pressure systems. Model-predicted horizontal and vertical transport pathways of Patagonian dust over the SAO were in reasonable agreement with remotely-sensed data. Comparison between remotely-sensed and offline calculated ocean surface chlorophyll-a concentrations indicated that, for the two dust outbreaks examined in this study, the deposition of bioavailable iron in the SAO through atmospheric pathways was insignificant. As the two dust transport episodes examined here represent typical outflows of mineral dust from South American sources, our study suggests that the atmospheric deposition of mineral dust is unlikely to induce large scale marine primary productivity and carbon sequestration in the South Atlantic sector of the Southern Ocean.

Sugar transporter genes of the brown planthopper, Nilaparvata lugens: A facilitated glucose/fructose transporter.

PubMed

Kikuta, Shingo; Kikawada, Takahiro; Hagiwara-Komoda, Yuka; Nakashima, Nobuhiko; Noda, Hiroaki

2010-11-01

The brown planthopper (BPH), Nilaparvata lugens, attacks rice plants and feeds on their phloem sap, which contains large amounts of sugars. The main sugar component of phloem sap is sucrose, a disaccharide composed of glucose and fructose. Sugars appear to be incorporated into the planthopper body by sugar transporters in the midgut. A total of 93 expressed sequence tags (ESTs) for putative sugar transporters were obtained from a BPH EST database, and 18 putative sugar transporter genes (Nlst1-18) were identified. The most abundantly expressed of these genes was Nlst1. This gene has previously been identified in the BPH as the glucose transporter gene NlHT1, which belongs to the major facilitator superfamily. Nlst1, 4, 6, 9, 12, 16, and 18 were highly expressed in the midgut, and Nlst2, 7, 8, 10, 15, 17, and 18 were highly expressed during the embryonic stages. Functional analyses were performed using Xenopus oocytes expressing NlST1 or 6. This showed that NlST6 is a facilitative glucose/fructose transporter that mediates sugar uptake from rice phloem sap in the BPH midgut in a manner similar to NlST1. Copyright © 2010 Elsevier Ltd. All rights reserved.

Vacuolar Transporters – Companions on a Longtime Journey[OPEN

PubMed Central

2018-01-01

Biochemical and electrophysiological studies on plant vacuolar transporters became feasible in the late 1970s and early 1980s, when methods to isolate large quantities of intact vacuoles and purified vacuolar membrane vesicles were established. However, with the exception of the H+-ATPase and H+-PPase, which could be followed due to their hydrolytic activities, attempts to purify tonoplast transporters were for a long time not successful. Heterologous complementation, T-DNA insertion mutants, and later proteomic studies allowed the next steps, starting from the 1990s. Nowadays, our knowledge about vacuolar transporters has increased greatly. Nevertheless, there are several transporters of central importance that have still to be identified at the molecular level or have even not been characterized biochemically. Furthermore, our knowledge about regulation of the vacuolar transporters is very limited, and much work is needed to get a holistic view about the interplay of the vacuolar transportome. The huge amount of information generated during the last 35 years cannot be summarized in such a review. Therefore, I decided to concentrate on some aspects where we were involved during my research on vacuolar transporters, for some our laboratories contributed more, while others contributed less. PMID:29295940

Calcium transport mechanism in molting crayfish revealed by microanalysis

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

Mizuhira, V.; Ueno, M.

1983-01-01

Crayfish provide a good model in which to study the transport mechanism of Ca ions. During the molting stage, decalcified Ca ions are transferred into the blood and accumulate in the gastrolith epithelium, after which a gastrolith is formed on the surface of the epithelium. The gastrolith is dissolved in the stomach after molting, and the Ca is reabsorbed and redistributed throughout the newly formed exoskeleton. We studied the mechanism of Ca transport by cytochemical precipitation of Ca ions and by electron microanalysis, including X-ray microanalysis (EDX) and electron energy-loss spectroscopy (EELS), with a computer. In EDX analysis, the finemore » precipitates of K-antimonate in the gastrolith mitochondria clearly defined Ca with antimony; we also observed a large amount of Ca-oxalate in the mitochondria, and Ca-K X-ray pulses were clearly defined. Ca-K X-rays were also detected from fresh freeze-substituted mitochondria. Finally, we succeeded in taking a Ca-L EELS image from the mitochondria of fresh freeze-substituted thin sections. Only a very small amount of Ca was detected from the cell membrane and other organelles. Ca-adenosine triphosphatase (ATPase) and Mg-ATPase activity was also very clearly demonstrated in the mitochondria. These enzymes may play an important role in Ca metabolism.« less

Cross-polar transport and scavenging of Siberian aerosols containing black carbon during the 2012 ACCESS summer campaign

NASA Astrophysics Data System (ADS)

Raut, Jean-Christophe; Marelle, Louis; Fast, Jerome D.; Thomas, Jennie L.; Weinzierl, Bernadett; Law, Katharine S.; Berg, Larry K.; Roiger, Anke; Easter, Richard C.; Heimerl, Katharina; Onishi, Tatsuo; Delanoë, Julien; Schlager, Hans

2017-09-01

During the ACCESS airborne campaign in July 2012, extensive boreal forest fires resulted in significant aerosol transport to the Arctic. A 10-day episode combining intense biomass burning over Siberia and low-pressure systems over the Arctic Ocean resulted in efficient transport of plumes containing black carbon (BC) towards the Arctic, mostly in the upper troposphere (6-8 km). A combination of in situ observations (DLR Falcon aircraft), satellite analysis and WRF-Chem simulations is used to understand the vertical and horizontal transport mechanisms of BC with a focus on the role of wet removal. Between the northwestern Norwegian coast and the Svalbard archipelago, the Falcon aircraft sampled plumes with enhanced CO concentrations up to 200 ppbv and BC mixing ratios up to 25 ng kg-1. During transport to the Arctic region, a large fraction of BC particles are scavenged by two wet deposition processes, namely wet removal by large-scale precipitation and removal in wet convective updrafts, with both processes contributing almost equally to the total accumulated deposition of BC. Our results underline that applying a finer horizontal resolution (40 instead of 100 km) improves the model performance, as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TEBC) in biomass burning plumes was larger (60 %), because it was impacted by small accumulated precipitation along trajectory (1 mm). In contrast TEBC was small (< 30 %) and accumulated precipitation amounts were larger (5-10 mm) in plumes influenced by urban anthropogenic sources and flaring activities in northern Russia, resulting in transport to lower altitudes. TEBC due to large-scale precipitation is responsible for a sharp meridional gradient in the distribution of BC concentrations. Wet removal in cumulus clouds is the cause of modeled vertical gradient of TEBC, especially in the mid-latitudes, reflecting the distribution of convective precipitation, but is dominated in the Arctic region by the large-scale wet removal associated with the formation of stratocumulus clouds in the planetary boundary layer (PBL) that produce frequent drizzle.

Modern geomorphology in a post-glacial landscape and implications for river restoration, eastern Yosemite Valley, Yosemite National Park, USA

NASA Astrophysics Data System (ADS)

Minear, J. T.; Wright, S. A.; Roche, J. W.

2011-12-01

Yosemite National Park, USA, is one of the most popular national parks in the country with over 3.9 million visitors annually. The majority of tourists visit a relatively small area around the Merced River in scenic eastern Yosemite Valley, which has resulted in degradation to the river and streambanks. The National Park Service is updating the long-term management plan for the Merced River which includes river restoration. A key component determining the success of future river restoration efforts is the transport and supply of sediment. For this study, we investigate the modern geomorphology of the eastern Yosemite Valley region. For the watershed and reach analyses, we draw from a variety of topographic and hydrologic records, including 20-years of data from permanent cross sections, aerial and ground-based LiDAR surveys, and a nearly 100-year hydrologic record. In addition, we utilize hydraulic and sediment transport models to investigate channel velocities, bed shear stress and sediment transport at the reach scale. From the watershed-scale analysis, it is likely that large-scale remnant glacial features exert a primary control on the sediment supply to the study area with relatively small volumes of both suspended and bedload sediment being contributed to the study site. Two of the three major watersheds, Tenaya Creek and the upper Merced River, likely contribute only small amounts of bedload downstream due to low-gradient depositional reaches. Though little-known, the third major watershed, Illilouette Creek, is the only watershed capable of contributing larger amounts of bedload material, though the bedload material is likely contributed only during high flow events. High flows in the Yosemite Valley region have two different distributions: large early winter storm events above the 20-year return interval, and moderate snowmelt flows at and below the 20-year return interval. Sediment transport analyses indicate that bedload transport is dominated by relatively frequent (<2 year) snowmelt flow events and that the coarsest material in the reach (>110 mm) is mobile during these flows. The permanent cross sections record large topographic changes, including infilling at key bars, associated with the 1997 flood, the largest recorded early winter event (100-year return interval). Following snowmelt events post-1997, cross sections are returning to near pre-1997 levels. The cross section data suggest there is likely a disconnect between sediment supplied to the reach and sediment transport, with the majority of sediment supply occurring during large early winter events while the majority of sediment transport occurs during snowmelt events. An implication of our findings for river restoration in this area of the Merced River is that the ability of the channel to rebuild streambanks is relatively low, given the low suspended sediment supply. In contrast, bedload transport is relatively frequent and occurs in significant quantities, suggesting that river restoration involving bed recovery (e.g. recovery of pools formed by riprap or bridges) should be relatively rapid if obstructions are removed.

Metabolic complications associated with use of diuretics.

PubMed

Palmer, Biff F

2011-11-01

Diuretics are commonly used therapeutic agents that act to inhibit sodium transport systems along the length of the renal tubule. The most effective diuretics are inhibitors of sodium chloride transport in the thick ascending limb of Henle. Loop diuretics mobilize large amounts of sodium chloride and water and produce a copious diuresis with a sharp reduction of extracellular fluid volume. As the site of action of diuretics moves downstream (thiazide and potassium-sparing diuretics), their effectiveness declines because the transport systems they inhibit have low transport capacity. Depending on the site of action diuretics can influence the renal handling of electrolyte-free water, calcium, potassium, protons, sodium bicarbonate, and uric acid. As a result, electrolyte and acid-base disorders commonly accompany diuretic use. Glucose and lipid abnormalities also can occur, particularly with the use of thiazide diuretics. This review focuses on the biochemical complications associated with the use of diuretics. The development of these complications can be minimized with careful monitoring, dosage adjustment, and replacement of electrolyte losses. Copyright © 2011 Elsevier Inc. All rights reserved.

Transport Distance of Invertebrate Environmental DNA in a Natural River

PubMed Central

Deiner, Kristy; Altermatt, Florian

2014-01-01

Environmental DNA (eDNA) monitoring is a novel molecular technique to detect species in natural habitats. Many eDNA studies in aquatic systems have focused on lake or ponds, and/or on large vertebrate species, but applications to invertebrates in river systems are emerging. A challenge in applying eDNA monitoring in flowing waters is that a species' DNA can be transported downstream. Whether and how far eDNA can be detected due to downstream transport remains largely unknown. In this study we tested for downstream detection of eDNA for two invertebrate species, Daphnia longispina and Unio tumidus, which are lake dwelling species in our study area. The goal was to determine how far away from the source population in a lake their eDNA could be detected in an outflowing river. We sampled water from eleven river sites in regular intervals up to 12.3 km downstream of the lake, developed new eDNA probes for both species, and used a standard PCR and Sanger sequencing detection method to confirm presence of each species' eDNA in the river. We detected D. longispina at all locations and across two time points (July and October); whereas with U. tumidus, we observed a decreased detection rate and did not detect its eDNA after 9.1 km. We also observed a difference in detection for this species at different times of year. The observed movement of eDNA from the source amounting to nearly 10 km for these species indicates that the resolution of an eDNA sample can be large in river systems. Our results indicate that there may be species' specific transport distances for eDNA and demonstrate for the first time that invertebrate eDNA can persist over relatively large distances in a natural river system. PMID:24523940

Long-term Effects of Organic Waste Fertilizers on Soil Structure, Tracer Transport, and Leaching of Colloids.

PubMed

Lekfeldt, Jonas Duus Stevens; Kjaergaard, Charlotte; Magid, Jakob

2017-07-01

Organic waste fertilizers have previously been observed to significantly affect soil organic carbon (SOC) content and soil structure. However, the effect of organic waste fertilizers on colloid dispersibility and leaching of colloids from topsoil has not yet been studied extensively. We investigated how the repeated application of different types of agricultural (liquid cattle slurry and solid cattle manure) and urban waste fertilizers (sewage sludge and composted organic household waste) affected soil physical properties, colloid dispersion from aggregates, tracer transport, and colloid leaching from intact soil cores. Total porosity was positively correlated with SOC content. Yearly applications of sewage sludge increased absolute microporosity (pores <30 μm) and decreased relative macroporosity (pores >30 μm) compared with the unfertilized control, whereas organic household waste compost fertilization increased both total porosity and the absolute porosity in all pore size classes (though not significant for 100-600 μm). Treatments receiving large amounts of organic fertilizers exhibited significantly lower levels of dispersible colloids compared with an unfertilized control and a treatment that had received moderate applications of cattle slurry. The content of water-dispersible colloids could not be explained by a single factor, but differences in SOC content, electrical conductivity, and sodium adsorption ratio were important factors. Moreover, we found that the fertilizer treatments did not significantly affect the solute transport properties of the topsoil. Finally, we found that the leaching of soil colloids was significantly decreased in treatments that had received large amounts of organic waste fertilizers, and we ascribe this primarily to treatment-induced differences in effluent electrical conductivity during leaching. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Bathymetry and Sediment-Storage Capacity Change in Three Reservoirs on the Lower Susquehanna River, 1996-2008

USGS Publications Warehouse

Langland, Michael J.

2009-01-01

The Susquehanna River transports a substantial amount of the sediment and nutrient load to the Chesapeake Bay. Upstream of the bay, three large dams and their associated reservoirs trap a large amount of the transported sediment and associated nutrients. During the fall of 2008, the U.S. Geological Survey in cooperation with the Pennsylvania Department of Environmental Protection completed bathymetric surveys of three reservoirs on the lower Susquehanna River to provide an estimate of the remaining sediment-storage capacity. Previous studies indicated the upper two reservoirs were in equilibrium with long-term sediment storage; only the most downstream reservoir retained capacity to trap sediments. A differential global positioning system (DGPS) instrument was used to provide the corresponding coordinate position. Bathymetry data were collected using a single beam 210 kHz (kilohertz) echo sounder at pre-defined transects that matched previous surveys. Final horizontal (X and Y) and vertical (Z) coordinates of the geographic positions and depth to bottom were used to create bathymetric maps of the reservoirs. Results indicated that from 1996 to 2008 about 14,700,000 tons of sediment were deposited in the three reservoirs with the majority (12,000,000 tons) being deposited in Conowingo Reservoir. Approximately 20,000 acre-feet or 30,000,000 tons of remaining storage capacity is available in Conowingo Reservoir. At current transport (3,000,000 tons per year) and deposition (2,000,000 tons per year) rates and with no occurrence of major scour events due to floods, the remaining capacity may be filled in 15 to 20 years. Once the remaining sediment-storage capacity in the reservoirs is filled, sediment and associated phosphorus loads entering the Chesapeake Bay are expected to increase.

Sources of material for 'loess' deposits at 15°N in North Africa

NASA Astrophysics Data System (ADS)

McLaren, Sue; Smalley, Ian; O'Hara-Dhand, Ken

2014-05-01

Africa is not a loess-rich continent. Lacking are the large expanses of glacial terrain and the high cold mountain regions, which would have provided the material and processes for loess deposits. African geomorphology and climatic history did not favour the formation of major loess deposits. However, within the African setting there are situations which could lead to particle formation and loess deposition. Loess deposits are made from 'large' dust (i.e. particles around 30µm). Small dust (around 3µm) is generated in large amounts in Africa, and distributed over large distances. Large dust is not generated in significant amounts in Africa, and this accounts for the relative lack of loess deposits. It is a relative lack; examination of the map of loess distribution in the World by Scheidig 1934 (still the best world loess map) shows some possible loess in Africa. In particular there is a band across the continent at around 15°N. We propose some possible sources for this material, and fit these sources into a recently revised deterministic model of loess deposit formation. And look at some exotic but possible indicators of the loessic nature of the 15°N band. Three possible material sources are: (1). The Fonta-Djalon highlands to the west of the loess band, (2). The Bodélé Depression, towards the centre of the loess band, and (3). The Ethiopian highlands to the east. There is a convenient river associated with the loess band; the Niger rises in the Fonta-Djalon region and carries material through the loess zone. The catchment of the Niger is well placed to receive large dust material from the Bodélé depression. Most Bodélé material is small dust carried away in high suspension but small amounts of large dust could be transported to the Niger catchment. Material from the Ethiopian highlands makes up the Nile silt but again some could be transported to the west to contribute to the loess band- which is a modest loess deposit. The deposit can be examined with respect to the deterministic model of loess deposit formation which sets out four event aspects which must be accommodated. PTDC: provenance (of material), transportation, deposition and change- all need to be considered when loess deposit genesis is examined. In the case of the 15°N loess the P actions are speculative, and probably not very effective. In fact the deposits they deliver, as mapped by Scheidig, still have to be established as genuine loess. There are indicators of loessic nature; one is that they are favoured by tunnel nesting birds, in particular bee-eaters. Merops apiaster (the European bee-eater) travels large distances to nest in the European loess. The bee-eater nesting zones map nicely on to European loess distribution. In the 15°N zone there is a concentration of nesting activity by the Northern Carmine bee-eater (Merops nubicus) and we take this as an indicator of ground nature.

Investigation of the demulsification of water-in-oil emulsions formed when crude oil or fuel oil is spilt on the sea

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

Lee, M.A.

The highly viscous water-in-oil emulsions, formed when crude or fuel oil is spilt at sea, are difficult to collect, and expensive to transport as they contain 50 to 80% water. Laboratory experiments have been carried out to determine the factors to be considered in the demulsification of these emulsions. The important factors were found to be the choice and amount of demulsifier, the temperature, and the time amount of mixing during the addition of the demulsifier. These preliminary findings will be used to develop large-scale demulsification systems for use at sea and on the beach, during collection of the emulsions.more » (Copyright (c) Crown Copyright 1980.)« less

Volatile transfer and recycling at convergent margins: Mass-balance and insights from high-P/T metamorphic rocks

NASA Astrophysics Data System (ADS)

Bebout, Gray E.

The efficiency with which volatiles are deeply subducted is governed by devolatilization histories and the geometries and mechanisms of fluid transport deep in subduction zones. Metamorphism along the forearc slab-mantle interface may prevent the deep subduction of many volatile components (e.g., H2O, Cs, B, N, perhaps As, Sb, and U) and result in their transport in fluids toward shallower reservoirs. The release, by devolatilization, and transport of such components toward the seafloor or into the forearc mantle wedge, could in part explain the imbalances between the estimated amounts of subducted volatiles and the amounts returned to Earth's surface. The proportion of the initially subducted volatile component that is retained in rocks subducted to depths greater than those beneath magmatic arcs (>100 km) is largely unknown, complicating assessments of deep mantle volatile budgets. Isotopic and trace element data and volatile contents for the Catalina Schist, the Franciscan Complex, and eclogite-facies complexes in the Alps (and elsewhere) provide insight into the nature and magnitude of fluid production and transport deep in subduction zones and into the possible effects of metamorphism on the compositions of subducting rocks. Compatibilities of the compositions of the subduction-related rocks and fluids with the isotopic and trace element compositions of various mantle-derived materials (igneous rocks, xenoliths, serpentinite seamounts) indicate the potential to trace the recycling of rock and fluid reservoirs chemically and isotopically fractionated during subduction-zone metamorphism.

Pht2;1 encodes a low-affinity phosphate transporter from Arabidopsis.

PubMed Central

Daram, P; Brunner, S; Rausch, C; Steiner, C; Amrhein, N; Bucher, M

1999-01-01

An Arabidopsis genomic sequence was recently shown to share similarity with bacterial and eukaryotic phosphate (Pi) transporters. We have cloned the corresponding cDNA, which we named Pht2;1, and subsequently performed gene expression studies and functional analysis of the protein product. The cDNA encodes a 61-kD protein with a putative topology of 12 transmembrane (TM) domains interrupted by a large hydrophilic loop between TM8 and TM9. Two boxes of eight and nine amino acids, located in the N- and C-terminal domains, respectively, are highly conserved among species across all kingdoms (eubacteria, archea, fungi, plants, and animals). The Pht2;1 gene is predominantly expressed in green tissue, the amount of transcript staying constant in leaves irrespective of the Pi status of the shoot; in roots, however, there is a marginal increase in mRNA amounts in response to Pi deprivation. Although the protein is highly similar to eukaryotic sodium-dependent Pi transporters, functional analysis of the Pht2;1 protein in mutant yeast cells indicates that it is a proton/Pi symporter dependent on the electrochemical gradient across the plasma membrane. Its fairly high apparent K(m) for Pi (0.4 mM) and high mRNA content in the shoot, especially in leaves, suggest a role for shoot organs in Pi loading. Pht2;1 thus differs from members of the recently described plant Pi transporter family in primary structure, affinity for Pi, and presumed function. PMID:10559441

Hydraulics of Asteroxylon mackei, an early Devonian vascular plant, and the early evolution of water transport tissue in terrestrial plants.

PubMed

Wilson, J P; Fischer, W W

2011-03-01

The core of plant physiology is a set of functional solutions to a tradeoff between CO(2) acquisition and water loss. To provide an important evolutionary perspective on how the earliest land plants met this tradeoff, we constructed a mathematical model (constrained geometrically with measurements of fossils) of the hydraulic resistance of Asteroxylon, an Early Devonian plant. The model results illuminate the water transport physiology of one of the earliest vascular plants. Results show that Asteroxylon's vascular system contains cells with low hydraulic resistances; these resistances are low because cells were covered by scalariform pits, elliptical structures that permit individual cells to have large areas for water to pass from one cell to another. Asteroxylon could move a large amount of water quickly given its large pit areas; however, this would have left these plants particularly vulnerable to damage from excessive evapotranspiration. These results highlight a repeated pattern in plant evolution, wherein the evolution of highly conductive vascular tissue precedes the appearance of adaptations to increase water transport safety. Quantitative insight into the vascular transport of Asteroxylon also allows us to reflect on the quality of CO(2) proxy estimates based on early land plant fossils. Because Asteroxylon's vascular tissue lacked any safety features to prevent permanent damage, it probably used stomatal abundance and behavior to prevent desiccation. If correct, low stomatal frequencies in Asteroxylon reflect the need to limit evapotranspiration, rather than adaptation to high CO(2) concentrations in the atmosphere. More broadly, methods to reveal and understand water transport in extinct plants have a clear use in testing and bolstering fossil plant-based paleoclimate proxies. © 2011 Blackwell Publishing Ltd.

Potential development of compressed bio-methane gas production from pig farms and elephant grass silage for transportation in Thailand.

PubMed

Dussadee, Natthawud; Reansuwan, Kamoldara; Ramaraj, Rameshprabu

2014-03-01

This research project evaluated biogas production using anaerobic co-digestion of pig manure and elephant grass silage in large scale to delivered transportation directly for cars. Anaerobic co-digestion was estimated in three full-scale continuously stirred tank reactors (CSTRs) at 40°C. In the form of compressed bio-methane gas (CBG) production was 14,400m(3)/day (CH4 60-70%) amount of CBG was 9600m(3)/day. The procedure was enhanced by using molecular sieve, activated carbon for removal of moisture and CO2 membrane H2S and CO2 respectively. The results were demonstrated the amount of CO2, H2S gas was reduced along with CH4 was improved up to 90% by volume and compressed to 250bar tank pressure gauge to the fuel for cars. The CBG production, methane gas improvement and performance were evaluated before entering the delivered systems according to the energy standards. The production of CBG is advantageous to strengthen the Thailand biogas market. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dietary fatty acids regulate hepatic low density lipoprotein (LDL) transport by altering LDL receptor protein and mRNA levels.

PubMed Central

Horton, J D; Cuthbert, J A; Spady, D K

1993-01-01

The concentration of LDL in plasma is strongly influenced by the amount and the type of lipid in the diet. Recent studies in the hamster have shown that dietary fatty acids differentially affect circulating LDL levels primarily by altering receptor-dependent LDL uptake in the liver. To investigate the mechanistic basis of this effect, rates of receptor-dependent LDL transport in the liver were correlated with LDL receptor protein and mRNA levels in hamsters fed safflower oil or coconut oil and varying amounts of cholesterol. Hepatic LDL receptor activity was significantly lower in animals fed coconut oil than in animals fed safflower oil at all levels of cholesterol intake (26, 53, and 61% lower at cholesterol intakes of 0, 0.06, and 0.12%, respectively). These fatty acid-induced changes in hepatic LDL receptor activity were accompanied by parallel changes in hepatic LDL receptor protein and mRNA levels, suggesting that dietary fatty acids regulate the LDL receptor pathway largely at the mRNA level. Images PMID:8349814

Evaluation of the Consequences of a Cistern Truck Accident While Transporting Dangerous Substances through a Tunnel.

PubMed

Malecha, Ziemowit M; Poliski, Jarosaw; Chorowski, Maciej

2017-12-01

The transportation of dangerous substances by truck carriers harbors important safety issues in both road and mine tunnels. Even though traffic conditions in road and mine tunnels are different, the potential geometric and hydrodynamic similarities can lead to similar effects from the uncontrolled leakage of the dangerous material. This work was motivated by the design study of the LAGUNA-LBNO (Large Apparatus studying Grand Unification and Neutrino Astrophysics and Long Baseline Neutrino Oscillations) project. The considered neutrino detector requires a huge amount of liquid argon, which must be transported down the tunnel. The present work focuses on the estimation of the most credible incident and the resulting consequences in the case of a truck accident in the tunnel. The approach and tools used in the present work are generic and can be adapted to other similar situations. © 2017 Society for Risk Analysis.

Identification of groundwater parameters at Columbus, Mississippi, using a 3D inverse flow and transport model

USGS Publications Warehouse

Barlebo, H.C.; Rosbjerg, D.; Hill, M.C.

1996-01-01

An extensive amount of data including hydraulic heads, hydraulic conductivities and concentrations of several solutes from controlled injections have been collected during the MADE 1 and MADE 2 experiments at a heterogeneous site near Columbus, Mississippi. In this paper the use of three-dimensional inverse groundwater models including simultaneous estimation of flow and transport parameters is proposed to help identify the dominant characteristics at the site. Simulations show that using a hydraulic conductivity distribution obtained from 2187 borehole flowmeter tests directly in the model produces poor matches to the measured hydraulic heads and tritium concentrations. Alternatively, time averaged hydraulic head maps are used to define zones of constant hydraulic conductivity to be estimated. Preliminary simulations suggest that in the case of conservative transport many, but not all, of the major plume characteristics can be explained by large-scale heterogeneity in recharge and hydraulic conductivity.

The IsoDAR high intensity H2+ transport and injection tests

NASA Astrophysics Data System (ADS)

Alonso, J.; Axani, S.; Calabretta, L.; Campo, D.; Celona, L.; Conrad, J. M.; Day, A.; Castro, G.; Labrecque, F.; Winklehner, D.

2015-10-01

This technical report reviews the tests performed at the Best Cyclotron Systems, Inc. facility in regards to developing a cost effective ion source, beam line transport system, and acceleration system capable of high H2+ current output for the IsoDAR (Isotope Decay At Rest) experiment. We begin by outlining the requirements for the IsoDAR experiment then provide overviews of the Versatile Ion Source (VIS), Low Energy Beam Transport (LEBT) system, spiral inflector, and cyclotron. The experimental measurements are then discussed and the results are compared with a thorough set of simulation studies. Of particular importance we note that the VIS proved to be a reliable ion source capable of generating a large amount of H2+ current. The results suggest that with further upgrades, the VIS could potentially be a suitable candidate for IsoDAR. The conclusion outlines the key results from our tests and introduces the forthcoming work this technical report has motivated.

26 CFR 1.613-4 - Gross income from the property in the case of minerals other than oil and gas.

Code of Federal Regulations, 2013 CFR

2013-04-01

... analysis of actual competitive sales by the taxpayer or others, the dollar figure or amount which most... amounts computed for cost control or similar financial or accounting books and records if that method has... transportation, the cost attributable to nonmining transportation shall be an amount which is in the same ratio...

26 CFR 1.613-4 - Gross income from the property in the case of minerals other than oil and gas.

Code of Federal Regulations, 2012 CFR

2012-04-01

... analysis of actual competitive sales by the taxpayer or others, the dollar figure or amount which most... amounts computed for cost control or similar financial or accounting books and records if that method has... transportation, the cost attributable to nonmining transportation shall be an amount which is in the same ratio...

26 CFR 1.613-4 - Gross income from the property in the case of minerals other than oil and gas.

Code of Federal Regulations, 2014 CFR

2014-04-01

... analysis of actual competitive sales by the taxpayer or others, the dollar figure or amount which most... amounts computed for cost control or similar financial or accounting books and records if that method has... transportation, the cost attributable to nonmining transportation shall be an amount which is in the same ratio...

Transport calculations in the Tasman and Coral seas

NASA Astrophysics Data System (ADS)

Thompson, R. O. R. Y.; Veronis, G.

1980-05-01

The inverse method ( WUNSCH, Reviews of Geophysics and Space Physics, 16, 583-620, 1978) has been used to determine the flow for a closed-box region in the Tasman and Coral seas. The object of the study was to determine the large scale transport through the region, and in particular, to obtain an updated estimate of the amount of water carried by the East Australian Current. We conclude that there was no evidence of an East Australian Current in late March, 1960, when the only strong, identifiable feature was a cyclonic gyre in the CoralSea. As an East Australian Current has been identified at other times, the flow appears to be transient. A series of experiments testing various aspects of the use of the inverse method in such problems is also reported. Transports in the bottom layer are shown to be sensitive to noise and to the procedure adopted for extrapolating available data to the bottom, particularly in regions of large topographic variations. The importance of working with synoptic, as opposed to climatological, data is demonstrated by the experiments. It is also shown that local eddies can affect solution at relatively distant points.

A COMPREHENSIVE ANALYSIS OF CHLORINE TRANSPORT AND FATE FOLLOWING A LARGE ENVIRONMENTAL RELEASE

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

Buckley, R.; Hunter, C.; Werth, D.

2011-05-10

A train derailment occurred in Graniteville, South Carolina during the early morning of January 6, 2005, and resulted in the release of a large amount of cryogenic pressurized liquid chlorine to the environment in a short time period. A comprehensive evaluation of the transport and fate of the released chlorine was performed, accounting for dilution, diffusion, transport and deposition into the local environment. This involved the characterization of a three-phased chlorine release, a detailed determination of local atmospheric mechanisms acting on the released chlorine, the establishment of atmospheric-hydrological physical exchange mechanisms, and aquatic dilution and mixing. This presentation will providemore » an overview of the models used in determining the total air-to-water mass transfer estimated to have occurred as a result of the roughly 60 tons of chlorine released into the atmosphere from the train derailment. The assumptions used in the modeling effort will be addressed, along with a comparison with available observational data to validate the model results. Overall, model-estimated chlorine concentrations in the airborne plume compare well with human and animal exposure data collected in the days after the derailment.« less

Selective accumulation of biotin in arterial chemoreceptors: requirement for carotid body exocytotic dopamine secretion

PubMed Central

Ortega‐Sáenz, Patricia; Macías, David; Levitsky, Konstantin L.; Rodríguez‐Gómez, José A.; González‐Rodríguez, Patricia; Bonilla‐Henao, Victoria; Arias‐Mayenco, Ignacio

2016-01-01

Key points Biotin, a vitamin whose main role is as a coenzyme for carboxylases, accumulates at unusually large amounts within cells of the carotid body (CB).In biotin‐deficient rats biotin rapidly disappears from the blood; however, it remains at relatively high levels in CB glomus cells. The CB contains high levels of mRNA for SLC5a6, a biotin transporter, and SLC19a3, a thiamine transporter regulated by biotin.Animals with biotin deficiency exhibit pronounced metabolic lactic acidosis. Remarkably, glomus cells from these animals have normal electrical and neurochemical properties. However, they show a marked decrease in the size of quantal dopaminergic secretory events.Inhibitors of the vesicular monoamine transporter 2 (VMAT2) mimic the effect of biotin deficiency. In biotin‐deficient animals, VMAT2 protein expression decreases in parallel with biotin depletion in CB cells.These data suggest that dopamine transport and/or storage in small secretory granules in glomus cells depend on biotin. Abstract Biotin is a water‐soluble vitamin required for the function of carboxylases as well as for the regulation of gene expression. Here, we report that biotin accumulates in unusually large amounts in cells of arterial chemoreceptors, carotid body (CB) and adrenal medulla (AM). We show in a biotin‐deficient rat model that the vitamin rapidly disappears from the blood and other tissues (including the AM), while remaining at relatively high levels in the CB. We have also observed that, in comparison with other peripheral neural tissues, CB cells contain high levels of SLC5a6, a biotin transporter, and SLC19a3, a thiamine transporter regulated by biotin. Biotin‐deficient rats show a syndrome characterized by marked weight loss, metabolic lactic acidosis, aciduria and accelerated breathing with normal responsiveness to hypoxia. Remarkably, CB cells from biotin‐deficient animals have normal electrophysiological and neurochemical (ATP levels and catecholamine synthesis) properties; however, they exhibit a marked decrease in the size of quantal catecholaminergic secretory events, which is not seen in AM cells. A similar differential secretory dysfunction is observed in CB cells treated with tetrabenazine, a selective inhibitor of the vesicular monoamine transporter 2 (VMAT2). VMAT2 is highly expressed in glomus cells (in comparison with VMAT1), and in biotin‐deficient animals VMAT2 protein expression decreases in parallel with the decrease of biotin accumulated in CB cells. These data suggest that biotin has an essential role in the homeostasis of dopaminergic transmission modulating the transport and/or storage of transmitters within small secretory granules in glomus cells. PMID:27570189

Systematic procedures to determine incentive/disincentive dollar amounts for highway transportation construction projects.

DOT National Transportation Integrated Search

2012-06-01

The Federal Highway Administration has encouraged state transportation agencies to implement Incentive/Disincentive (I/D) contracting provisions for early project completion. Although general guidelines to determine the I/D dollar amount for a projec...

The Aliso Canyon Natural Gas Leak : Large Eddy Simulations for Modeling Atmospheric Dynamics and Interpretation of Observations.

NASA Astrophysics Data System (ADS)

Prasad, K.; Thorpe, A. K.; Duren, R. M.; Thompson, D. R.; Whetstone, J. R.

2016-12-01

The National Institute of Standards and Technology (NIST) has supported the development and demonstration of a measurement capability to accurately locate greenhouse gas sources and measure their flux to the atmosphere over urban domains. However, uncertainties in transport models which form the basis of all top-down approaches can significantly affect our capability to attribute sources and predict their flux to the atmosphere. Reducing uncertainties between bottom-up and top-down models will require high resolution transport models as well as validation and verification of dispersion models over an urban domain. Tracer experiments involving the release of Perfluorocarbon Tracers (PFTs) at known flow rates offer the best approach for validating dispersion / transport models. However, tracer experiments are limited by cost, ability to make continuous measurements, and environmental concerns. Natural tracer experiments, such as the leak from the Aliso Canyon underground storage facility offers a unique opportunity to improve and validate high resolution transport models, test leak hypothesis, and to estimate the amount of methane released.High spatial resolution (10 m) Large Eddy Simulations (LES) coupled with WRF atmospheric transport models were performed to simulate the dynamics of the Aliso Canyon methane plume and to quantify the source. High resolution forward simulation results were combined with aircraft and tower based in-situ measurements as well as data from NASA airborne imaging spectrometers. Comparison of simulation results with measurement data demonstrate the capability of the LES models to accurately model transport and dispersion of methane plumes over urban domains.

The Origin of the Terra Meridiani Sediments: Volatile Transport and the Formation of Sulfate Bearing Layered Deposits on Mars

NASA Technical Reports Server (NTRS)

Niles, P.B.

2008-01-01

The chemistry, sedimentology, and geology of the Meridiani sedimentary deposits are best explained by eolian reworking of the sublimation residue of a large scale ice/dust deposit. This large ice deposit was located in close proximity to Terra Meridiani and incorporated large amounts of dust, sand, and SO2 aerosols generated by impacts and volcanism during early martian history. Sulfate formation and chemical weathering of the initial igneous material is hypothesized to have occurred inside of the ice when the darker mineral grains were heated by solar radiant energy. This created conditions in which small films of liquid water were created in and around the mineral grains. This water dissolved the SO2 and reacted with the mineral grains forming an acidic environment under low water/rock conditions. Subsequent sublimation of this ice deposit left behind large amounts of weathered sublimation residue which became the source material for the eolian process that deposited the Terra Meridiani deposit. The following features of the Meridiani sediments are best explained by this model: The large scale of the deposit, its mineralogic similarity across large distances, the cation-conservative nature of the weathering processes, the presence of acidic groundwaters on a basaltic planet, the accumulation of a thick sedimentary sequence outside of a topographic basin, and the low water/rock ratio needed to explain the presence of very soluble minerals and elements in the deposit. Remote sensing studies have linked the Meridiani deposits to a number of other martian surface features through mineralogic similarities, geomorphic similarities, and regional associations. These include layered deposits in Arabia Terra, interior layered deposits in the Valles Marineris system, southern Elysium/Aeolis, Amazonis Planitia, and the Hellas basin, Aram Chaos, Aureum Chaos, and Ioni Chaos. The common properties shared by these deposits suggest that all of these deposits share a common formation process which must have acted over a large area of Mars. The results of this study suggest a mechanism for volatile transport on Mars without invoking an early greenhouse. They also imply a common formation mechanism for most of the sulfate minerals and layered deposits on Mars, which explains their common occurrence.

Large-scale multiplex absolute protein quantification of drug-metabolizing enzymes and transporters in human intestine, liver, and kidney microsomes by SWATH-MS: Comparison with MRM/SRM and HR-MRM/PRM.

PubMed

Nakamura, Kenji; Hirayama-Kurogi, Mio; Ito, Shingo; Kuno, Takuya; Yoneyama, Toshihiro; Obuchi, Wataru; Terasaki, Tetsuya; Ohtsuki, Sumio

2016-08-01

The purpose of the present study was to examine simultaneously the absolute protein amounts of 152 membrane and membrane-associated proteins, including 30 metabolizing enzymes and 107 transporters, in pooled microsomal fractions of human liver, kidney, and intestine by means of SWATH-MS with stable isotope-labeled internal standard peptides, and to compare the results with those obtained by MRM/SRM and high resolution (HR)-MRM/PRM. The protein expression levels of 27 metabolizing enzymes, 54 transporters, and six other membrane proteins were quantitated by SWATH-MS; other targets were below the lower limits of quantitation. Most of the values determined by SWATH-MS differed by less than 50% from those obtained by MRM/SRM or HR-MRM/PRM. Various metabolizing enzymes were expressed in liver microsomes more abundantly than in other microsomes. Ten, 13, and eight transporters listed as important for drugs by International Transporter Consortium were quantified in liver, kidney, and intestinal microsomes, respectively. Our results indicate that SWATH-MS enables large-scale multiplex absolute protein quantification while retaining similar quantitative capability to MRM/SRM or HR-MRM/PRM. SWATH-MS is expected to be useful methodology in the context of drug development for elucidating the molecular mechanisms of drug absorption, metabolism, and excretion in the human body based on protein profile information. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The absorption and transport of magnolol in Caco-2 cell model.

PubMed

Wu, An-Guo; Zeng, Bao; Huang, Meng-Qiu; Li, Sheng-Mei; Chen, Jian-Nan; Lai, Xiao-Ping

2013-03-01

To investigate the absorption and transport mechanism of magnolol in Caco-2 cell model. A human intestinal epithelial cell model Caco-2 cell in vitro cultured was applied to study the absorption and transport of magnolol, the effects of time, donor concentration, P-gp inhibitor verapamil, pH and temperature on the absorption and transport of magnolol were investigated. The determination of magnolol was performed by high performance liquid chromatography, then the values of apparent permeability coefficient (P app ) and P ratio Basolateral-to-Apical (BL-to-AP)/Apical-to-Basolateral (AP-to-BL) were calculated. In Caco-2 cell model, comparing the amounts of transport of AP-to-BL and BL-to-AP, the latter was larger. At the same donor concentration, either the amounts of transport of AP-to-BL or BL-to-AP increased with increase in donor concentration and incubation time. Verapamil could significantly improve the amounts of transport of AP-to-BL. The transport of AP-to-BL and BL-to-AP depended on temperature, and there was no significant effect of pH on the transport of AP-to-BL. Magnolol could be transported through the intestinal mucosa via a passive diffusion mechanism primarily, coexisting with a carrier-mediated transport, at the same time, the efflux mechanism could be involved.

A numerical investigation of fine sediment resuspension in the wave boundary layer - effect of hindered settling and bedforms

NASA Astrophysics Data System (ADS)

Hsu, T. J.; Cheng, Z.; Yu, X.

2016-02-01

The wave bottom boundary layer is a major conduit delivering fine terrestrial sediments to the continental margin. Hence, studying the fine sediment resuspension in the wave boundary layer is crucial to the understanding of various components of the earth system, such as carbon cycle. By assuming the settling velocity to be a constant in each simulation, previous turbulence-resolving numerical simulations reveal the existence of three transport modes in the wave boundary layer associated with the sediment availability. As the sediment availability and hence the sediment-induced stable stratification increase, a sequence of transport modes, namely, (I) well-mixed transport, (II) formulation of lutocline resembling a two-layer system, and (III) completely laminarized transport are observed. In general, the settling velocity is a flow variable due to the floc dynamics and hindered settling. This study further investigate the effect of hindered settling. Particularly, for flocs with lower gelling concentrations, the hindered settling effect can play a key role in sustaining large amount of suspended sediment load and results in the laminarized transport (III). For the simulation with a very significant hindered settling effect due to a low gelling concentration, results also indicate the occurrence of gelling ignition, a state in which the erosion rate is always higher than the deposition rate. A condition for the occurrence of gelling ignition is proposed for a range of wave intensities as a function of sediment/floc properties and erodibility parameters. These aforementioned studies are limited to fine sediment transport over a flat bed. However, recent field and laboratory observation show that a small amount of sand fraction can lead to the formation of small bedforms, which can armor the bed while in the meantime enhance near bed turbulence. Preliminary investigation on the effect of bedforms on the resulting transport modes will also be presented.

Production and disposal of waste materials from gas and oil extraction from the Marcellus Shale Play in Pennsylvania

USGS Publications Warehouse

Maloney, Kelly O.; Yoxtheimer, David A.

2012-01-01

The increasing world demand for energy has led to an increase in the exploration and extraction of natural gas, condensate, and oil from unconventional organic-rich shale plays. However, little is known about the quantity, transport, and disposal method of wastes produced during the extraction process. We examined the quantity of waste produced by gas extraction activities from the Marcellus Shale play in Pennsylvania for 2011. The main types of wastes included drilling cuttings and fluids from vertical and horizontal drilling and fluids generated from hydraulic fracturing [i.e., flowback and brine (formation) water]. Most reported drill cuttings (98.4%) were disposed of in landfills, and there was a high amount of interstate (49.2%) and interbasin (36.7%) transport. Drilling fluids were largely reused (70.7%), with little interstate (8.5%) and interbasin (5.8%) transport. Reported flowback water was mostly reused (89.8%) or disposed of in brine or industrial waste treatment plants (8.0%) and largely remained within Pennsylvania (interstate transport was 3.1%) with little interbasin transport (2.9%). Brine water was most often reused (55.7%), followed by disposal in injection wells (26.6%), and then disposed of in brine or industrial waste treatment plants (13.8%). Of the major types of fluid waste, brine water was most often transported to other states (28.2%) and to other basins (9.8%). In 2011, 71.5% of the reported brine water, drilling fluids, and flowback was recycled: 73.1% in the first half and 69.7% in the second half of 2011. Disposal of waste to municipal sewage treatment plants decreased nearly 100% from the first half to second half of 2011. When standardized against the total amount of gas produced, all reported wastes, except flowback sands, were less in the second half than the first half of 2011. Disposal of wastes into injection disposal wells increased 129.2% from the first half to the second half of 2011; other disposal methods decreased. Some issues with data were uncovered during the analytical process (e.g., correct geospatial location of disposal sites and the proper reporting of end use of waste) that obfuscated the analyses; correcting these issues will help future analyses.

Aeolian sand transport and aeolian deposits on Venus: A review

NASA Astrophysics Data System (ADS)

Kreslavsly, Mikhail A.; Bondarenko, Nataliya V.

2017-06-01

We review the current state of knowledge about aeolian sand transport and aeolian bedforms on planet Venus. This knowledge is limited by lack of observational data. Among the four planetary bodies of the Solar System with sufficient atmospheres in contact with solid surfaces, Venus has the densest atmosphere; the conditions there are transitional between those for terrestrial subaerial and subaqueous transport. The dense atmosphere causes low saltation threshold and short characteristic saltation length, and short scale length of the incipient dunes. A few lines of evidence indicate that the typical wind speeds exceed the saltation threshold; therefore, sand transport would be pervasive, if sand capable of saltation is available. Sand production on Venus is probably much slower than on the Earth; the major terrestrial sand sinks are also absent, however, lithification of sand through sintering is expected to be effective under Venus' conditions. Active transport is not detectable with the data available. Aeolian bedforms (transverse dunes) resolved in the currently available radar images occupy a tiny area on the planet; however, indirect observations suggest that small-scale unresolved aeolian bedforms are ubiquitous. Aeolian transport is probably limited by sand lithification causing shortage of saltation-capable material. Large impact events likely cause regional short-term spikes in aeolian transport by supplying a large amount of sand-size particles, as well as disintegration and activation of older indurated sand deposits. The data available are insufficient to understand whether the global aeolian sand transport occurs or not. More robust knowledge about aeolian transport on Venus is essential for future scientific exploration of the planet, in particular, for implementation and interpretation of geochemical studies of surface materials. High-resolution orbital radar imaging with local to regional coverage and desirable interferometric capabilities is the most effective way to obtain essential new knowledge about aeolian transport on Venus.

Characterization of rapid intervascular transport of cadmium in rice stem by radioisotope imaging

PubMed Central

Tanoi, Keitaro

2013-01-01

Participation of the intervascular transport system within the rice stem during cadmium (Cd) partitioning was investigated by characterizing 109Cd behaviour in the shoot. In addition, 45Ca, 32P, and 35S partitioning patterns were analysed for comparison with that of 109Cd. Each tracer was applied to the seedling roots for 15min, and the shoots were harvested either at 15min (i.e. immediately after tracer application) or at 48h. Distribution patterns of each element at 15min were studied to identify the primary transport pathway before remobilization was initiated. 32P was preferentially transported to completely expanded leaf blades having the highest transpiration rate. The newest leaf received minimal amounts of 32P. In contrast, the amount of 35S transported to the newest leaf was similar to that transported to the other mature leaf blades. Preferential movement towards the newest leaf was evident for 109Cd and 45Ca. These results directly indicate that elemental transport is differentially regulated in the vegetative stem as early as 15min before the elements are transported to leaves. Cd behaviour in the stem was investigated in detail by obtaining serial section images from the bottom part of shoots after 109Cd was applied to a single crown root. At 30min, the maximum amount of 109Cd was distributed in the peripheral cylinder of the longitudinal vascular bundles (PV) and, interestingly, some amount of 109Cd was transported downwards along the PV. This transport manner of 109Cd provides evidence that Cd can be loaded on the phloem at the stem immediately after Cd is transported from the root. PMID:23202130

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).

Lithium isotopes in large rivers reveal the cannibalistic nature of modern continental weathering and erosion

NASA Astrophysics Data System (ADS)

Dellinger, Mathieu; Gaillardet, Jérôme; Bouchez, Julien; Calmels, Damien; Galy, Valier; Hilton, Robert G.; Louvat, Pascale; France-Lanord, Christian

2014-09-01

The erosion of major mountain ranges is thought to be largely cannibalistic, recycling sediments that were deposited in the ocean or on the continents prior to mountain uplift. Despite this recognition, it has not yet been possible to quantify the amount of recycled material that is presently transported by rivers to the ocean. Here, we have analyzed the Li content and isotope composition (δLi7) of suspended sediments sampled along river depth profiles and bed sands in three of the largest Earth's river systems (Amazon, Mackenzie and Ganga-Brahmaputra rivers). The δLi7 values of river-sediments transported by these rivers range from +5.3 to -3.6‰ and decrease with sediment grain size. We interpret these variations as reflecting a mixture of unweathered rock fragments (preferentially transported at depth in the coarse fraction) and present-day weathering products (preferentially transported at the surface in the finest fraction). Only the finest surface sediments contain the complementary reservoir of Li solubilized by water-rock interactions within the watersheds. Li isotopes also show that river bed sands can be interpreted as a mixture between unweathered fragments of igneous and sedimentary rocks. A mass budget approach, based on Li isotopes, Li/Al and Na/Al ratios, solved by an inverse method allows us to estimate that, for the large rivers analyzed here, the part of solid weathering products formed by present-day weathering reactions and transported to the ocean do not exceed 35%. Li isotopes also show that the sediments transported by the Amazon, Mackenzie and Ganga-Brahmaputra river systems are mostly sourced from sedimentary rocks (>60%) rather than igneous rocks. This study shows that Li isotopes in the river particulate load are a good proxy for quantifying both the erosional rock sources and the fingerprint of present-day weathering processes. Overall, Li isotopes in river sediments confirm the cannibalistic nature of erosion and weathering.

Bronx River bed sediments phosphorus pool and phosphorus compound identification

NASA Astrophysics Data System (ADS)

Wang, J.; Pant, H. K.

2008-12-01

Phosphorus (P) transport in the Bronx River degraded water quality, decreased oxygen levels, and resulted in bioaccumulation in sediment potentially resulting in eutrophication, algal blooms and oxygen depletion under certain temperature and pH conditions. The anthropogenic P sources are storm water runoff, raw sewage discharge, fertilizer application in lawn, golf course and New York Botanical Garden; manure from the Bronx zoo; combined sewoverflows (CSO's) from parkway and Hunts Point sewage plant; pollutants from East River. This research was conducted in the urban river system in New York City area, in order to control P source, figure out P transport temporal and spatial variations and the impact on water quality; aimed to regulate P application, sharing data with Bronx River Alliance, EPA, DEP and DEC. The sediment characteristics influence the distribution and bioavailbility of P in the Bronx River. The P sequential extraction gave the quantitative analysis of the P pool, quantifying the inorganic and organic P from the sediments. There were different P pool patterns at the 15 sites, and the substantial amount of inorganic P pool indicated that a large amount P is bioavailable. The 31P- NMR (Nuclear Magnetic Resonance Spectroscopy) technology had been used to identify P species in the 15 sites of the Bronx River, which gave a qualitative analysis on phosphorus transport in the river. The P compounds in the Bronx River bed sediments are mostly glycerophophate (GlyP), nucleoside monophosphates (NMP), polynucleotides (PolyN), and few sites showed the small amount of glucose-6-phosphate (G6P), glycerophosphoethanoamine (GPEA), phosphoenopyruvates (PEP), and inosine monophosphate (IMP). The land use spatial and temporal variations influence local water P levels, P distributions, and P compositions.

Spatial Distribution of Fate and Transport Parameters Using Cxtfit in a Karstified Limestone Model

NASA Astrophysics Data System (ADS)

Toro, J.; Padilla, I. Y.

2017-12-01

Karst environments have a high capacity to transport and store large amounts of water. This makes karst aquifers a productive resource for human consumption and ecological integrity, but also makes them vulnerable to potential contamination of hazardous chemical substances. High heterogeneity and anisotropy of karst aquifer properties make them very difficult to characterize for accurate prediction of contaminant mobility and persistence in groundwater. Current technologies to characterize and quantify flow and transport processes at field-scale is limited by low resolution of spatiotemporal data. To enhance this resolution and provide the essential knowledge of karst groundwater systems, studies at laboratory scale can be conducted. This work uses an intermediate karstified lab-scale physical model (IKLPM) to study fate and transport processes and assess viable tools to characterize heterogeneities in karst systems. Transport experiments are conducted in the IKLPM using step injections of calcium chloride, uranine, and rhodamine wt tracers. Temporal concentration distributions (TCDs) obtained from the experiments are analyzed using the method of moments and CXTFIT to quantify fate and transport parameters in the system at various flow rates. The spatial distribution of the estimated fate and transport parameters for the tracers revealed high variability related to preferential flow heterogeneities and scale dependence. Results are integrated to define spatially-variable transport regions within the system and assess their fate and transport characteristics.

Observations of compound sawteeth in ion cyclotron resonant heating plasma using ECE imaging on experimental advanced superconducting tokamak

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

Hussain, Azam; Zhao, Zhenling; Xie, Jinlin, E-mail: jlxie@ustc.edu.cn

The spatial and temporal evolutions of compound sawteeth were directly observed using 2D electron cyclotron emission imaging on experimental advanced superconducting tokamak. The compound sawtooth consists of partial and full collapses. After partial collapse, the hot core survives as only a small amount of heat disperses outwards, whereas in the following full collapse a large amount of heat is released and the hot core dissipates. The presence of two q = 1 surfaces was not observed. Instead, the compound sawtooth occurs mainly at the beginning of an ion cyclotron resonant frequency heating pulse and during the L-H transition phase, which may bemore » related to heat transport suppression caused by a decrease in electron heat diffusivity.« less

Root canal volume change and transportation by Vortex Blue, ProTaper Next, and ProTaper Universal in curved root canals

PubMed Central

2018-01-01

Objectives The aim of this study was to compare root canal volume change and canal transportation by Vortex Blue (VB; Dentsply Tulsa Dental Specialties), ProTaper Next (PTN; Dentsply Maillefer), and ProTaper Universal (PTU; Dentsply Maillefer) nickel-titanium rotary files in curved root canals. Materials and Methods Thirty canals with 20°–45° of curvature from extracted human molars were used. Root canal instrumentation was performed with VB, PTN, and PTU files up to #30.06, X3, and F3, respectively. Changes in root canal volume before and after the instrumentation, and the amount and direction of canal transportation at 1, 3, and 5 mm from the root apex were measured by using micro-computed tomography. Data of canal volume change were statistically analyzed using one-way analysis of variance and Tukey test, while data of amount and direction of transportation were analyzed using Kruskal-Wallis and Mann-Whitney U test. Results There were no significant differences among 3 groups in terms of canal volume change (p > 0.05). For the amount of transportation, PTN showed significantly less transportation than PTU at 3 mm level (p = 0.005). VB files showed no significant difference in canal transportation at all 3 levels with either PTN or PTU files. Also, VB files showed unique inward transportation tendency in the apical area. Conclusions Other than PTN produced less amount of transportation than PTU at 3 mm level, all 3 file systems showed similar level of canal volume change and transportation, and VB file system could prepare the curved canals without significant shaping errors. PMID:29487834

Determining hillslope-channel connectivity in an agricultural catchment using rare-earth oxide tracers and random forests.

NASA Astrophysics Data System (ADS)

Masselink, Rens; Temme, Arnaud; Giménez, Rafael; Casalí, Javier; Keesstra, Saskia

2017-04-01

Soil erosion from agricultural areas is a large problem, because of off-site effects like the rapid filling of reservoirs. To mitigate the problem of sediments from agricultural areas reaching the channel, reservoirs and other surface waters, it is important to understand hillslope-channel connectivity and catchment connectivity. To determine the functioning of hillslope-channel connectivity and the continuation of transport of these sediments in the channel, it is necessary to obtain data on sediment transport from the hillslopes to the channels. Simultaneously, the factors that influence sediment export out of the catchment need to be studied. For measuring hillslope-channel sediment connectivity, Rare-Earth Oxide (REO) tracers were applied to a hillslope in an agricultural catchment in Navarre, Spain, preceding the winter of 2014-2015. The results showed that during the winter there was no sediment transport from the hillslope to the channel. Analysis of precipitation data showed that total precipitation quantities did not differ much from the mean. However, precipitation intensities were low, causing little sediment mobilisation. To test the implication of the REO results at the catchment scale, two conceptual models for sediment connectivity were assessed using a Random Forest (RF) machine learning method. One model proposes that small events provide sediment for large events, while the other proposes that only large events cause sediment detachment and small events subsequently remove these sediments from near and in the channel. The RF method was applied to a daily dataset of sediment yield from the catchment (N=2451 days), and two subsets of the whole dataset: small events (N=2319) and large events (N=132). For sediment yield prediction of small events, variables related to large preceding events were the most important. The model for large events underperformed and, therefore, we could not draw any immediate conclusions whether small events influence the amount of sediment exported during large events. Both REO tracers and RF method showed that low intensity events do not contribute any sediments to the channel in the Latxaga catchment (cf. Masselink et al., 2016). Sediment dynamics are dominated by sediment mobilisation during large (high intensity) events. Sediments are for a large part exported during those events, but large amount of sediments are deposited in and near the channel after these events. These sediments are gradually removed by small events. To better understand the delivery of sediments to the channel and how large and small events influence each other more field data on hillslope-channel connectivity and within-channel sediment dynamics is necessary. Reference: Masselink, R.J.H., Keesstra, S.D., Temme, A.J.A.M., Seeger, M., Giménez, R., Casalí, J., 2016. Modelling Discharge and Sediment Yield at Catchment Scale Using Connectivity Components. Land Degrad. Dev. 27, 933-945. doi:10.1002/ldr.2512

The influence of large-scale wind power on global climate.

PubMed

Keith, David W; Decarolis, Joseph F; Denkenberger, David C; Lenschow, Donald H; Malyshev, Sergey L; Pacala, Stephen; Rasch, Philip J

2004-11-16

Large-scale use of wind power can alter local and global climate by extracting kinetic energy and altering turbulent transport in the atmospheric boundary layer. We report climate-model simulations that address the possible climatic impacts of wind power at regional to global scales by using two general circulation models and several parameterizations of the interaction of wind turbines with the boundary layer. We find that very large amounts of wind power can produce nonnegligible climatic change at continental scales. Although large-scale effects are observed, wind power has a negligible effect on global-mean surface temperature, and it would deliver enormous global benefits by reducing emissions of CO(2) and air pollutants. Our results may enable a comparison between the climate impacts due to wind power and the reduction in climatic impacts achieved by the substitution of wind for fossil fuels.

Predicting the long-term (137)Cs distribution in Fukushima after the Fukushima Dai-ichi nuclear power plant accident: a parameter sensitivity analysis.

PubMed

Yamaguchi, Masaaki; Kitamura, Akihiro; Oda, Yoshihiro; Onishi, Yasuo

2014-09-01

Radioactive materials deposited on the land surface of Fukushima Prefecture from the Fukushima Dai-ichi Nuclear Power Plant explosion is a crucial issue for a number of reasons, including external and internal radiation exposure and impacts on agricultural environments and aquatic biota. Predicting the future distribution of radioactive materials and their fates is therefore indispensable for evaluation and comparison of the effectiveness of remediation options regarding human health and the environment. Cesium-137, the main radionuclide to be focused on, is well known to adsorb to clay-rich soils; therefore its primary transportation mechanism is in the form of soil erosion on the land surface and transport of sediment-sorbed contaminants in the water system. In this study, we applied the Soil and Cesium Transport model, which we have developed, to predict a long-term cesium distribution in the Fukushima area, based on the Universal Soil Loss Equation and simple sediment discharge formulas. The model consists of calculation schemes of soil erosion, transportation and deposition, as well as cesium transport and its future distribution. Since not all the actual data on parameters is available, a number of sensitivity analyses were conducted here to find the range of the output results due to the uncertainties of parameters. The preliminary calculation indicated that a large amount of total soil loss remained in slope, and the residual sediment was transported to rivers, deposited in rivers and lakes, or transported farther downstream to the river mouths. Most of the sediment deposited in rivers and lakes consists of sand. On the other hand, most of the silt and clay portions transported to river were transported downstream to the river mouths. The rate of sediment deposition in the Abukuma River basin was three times as high as those of the other 13 river basins. This may be due to the larger catchment area and more moderate channel slope of the Abukuma River basin than those of the other rivers. Annual sediment outflows from the Abukuma River and the total from the other 13 river basins were calculated as 3.2 × 10(4)-3.1 × 10(5) and 3.4 × 10(4)-2.1 × 10(5)ty(-1), respectively. The values vary between calculation cases because of the critical shear stress, the rainfall factor, and other differences. On the other hand, contributions of those parameters were relatively small for (137)Cs concentration within transported soil. This indicates that the total amount of (137)Cs outflow into the ocean would mainly be controlled by the amount of soil erosion and transport and the total amount of (137)Cs concentration remaining within the basin. Outflows of (137)Cs from the Abukuma River and the total from the other 13 river basins during the first year after the accident were calculated to be 2.3 × 10(11)-3.7 × 10(12) and 4.6 × 10(11)-6.5 × 10(12)Bqy(-1), respectively. The former results were compared with the field investigation results, and the order of magnitude was matched between the two, but the value of the investigation result was beyond the upper limit of model prediction. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis and integration of spatial data for transportation planning.

DOT National Transportation Integrated Search

2009-06-01

Transportation planning requires substantial amounts of data and cooperation among transportation planning : agencies. Advances in computer technology and the increasing availability of geographic information : systems (GIS) are giving transportation...

Holocene surge-history of the Eyjabakkajökull glacier inferred from varved lake sediments on eastern Iceland

NASA Astrophysics Data System (ADS)

Striberger, J.; Bjorck, S.; Ingolfsson, O.; Kjaer, K.; Snowball, I.; Uvo, C. B.

2009-12-01

Properties of varved lake sediments from Lake Lögurinn on eastern Iceland and their link to glacial processes of Eyjabakkajökull, a surging outlet glacier of the Vatnajökull ice cap, is examined. An 18 m long sediment sequence obtained from the lake, covering at least the past ~ 9 200 years, displays a distinct recurring pattern of light-coloured clay dominated laminae sections. The thickness of the light-coloured laminae is mainly controlled by the amount of glacial rock flour transported from Eyjabakkajökull. These light laminae are interlaid by coarser dark-coloured laminae mainly formed by suspended matter transported to the lake by the large non-glacial river Grímsá. During the recent surge of Eyjabakkajökull in 1972, the amount of suspended matter transported to the lake increased significantly. The surge was followed by years of recurring drainages of Lake Háöldulón, an ice-dammed lake that was formed shortly after the surge. As a result, the amount of glacial rock flour transported to Lake Lögurinn was higher than usual as long as Lake Háöldulón continued to drain (i.e. as long as the ice front was in an advanced position enough to dam the lake). This increase in glacially derived rock flour is reflected in the sediments, as the varve that was formed in 1972 constitutes the thickest light-coloured laminae deposited during the 20th century, which is followed by the second thickest light-coloured laminae, deposited in 1973. From there on, the thicknesses of the light-coloured laminae gradually fade out. Based on these modern observations, we suggest that the recurring cyclic pattern of light-coloured clay dominated laminae sections in the sediment sequence is related to past surges of Eyjabakkajökull, followed by drainages of Lake Háöldulón. Recurring cycles of light-coloured clay dominated laminae began to develop close to the Hekla-3 and Hekla-4 tephras (ca. 3000-4000 years BP), which also coincides with the time when the varves became more distinct. Further down in the sequence, the recurring cycles of light-coloured laminae are not found and any varves are in general diffuse or missing. Hypothetically, the reason for this might be that the suspended matter delivered from the glacier was transported elsewhere at this time. However, based on the large-scale morphology of the area, we find it more likely that Eyjabakkajökull, and thus parts of, or the whole Vatnajökull ice cap, was smaller or perhaps not present during the mid-Holocene and thus had little or no influence on the sedimentation in Lake Lögurinn.

Structural, magnetic and transport studies of Mn0.8Cr0.2CoGe alloy

NASA Astrophysics Data System (ADS)

Das, S. C.; Dutta, P.; Pramanick, S.; Chatterjee, S.

2018-04-01

Different physical and functional properties of Mn0.8Cr0.2CoGe alloy has been investigated through structural, magnetic and electrical transport measurements. Substitution of Cr for Mn results significant decrease in both structural and magnetic transition temperature and brings them well below the room temperature. A reasonable amount of conventional magnetocaloric effect (ΔS˜ - 2.22 J/kg-K for magnetic field (H) changing from 0 to 50 kOe) with large relative cooling power (251.7 J/kg for H changing from 0 to 50 kOe) has also been observed around the region of transition. On thermal cycling through the structural transition, noticeable training effect is found to be associated with the resistivity of the alloy.

Cross-polar transport and scavenging of Siberian aerosols containing black carbon during the 2012 ACCESS summer campaign

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

Raut, Jean -Christophe; Marelle, Louis; Fast, Jerome D.

During the ACCESS airborne campaign in July 2012, extensive boreal forest fires resulted in significant aerosol transport to the Arctic. A 10-day episode combining intense biomass burning over Siberia and low-pressure systems over the Arctic Ocean resulted in efficient transport of plumes containing black carbon (BC) towards the Arctic, mostly in the upper troposphere (6–8 km). Here, a combination of in situ observations (DLR Falcon aircraft), satellite analysis and WRF-Chem simulations is used to understand the vertical and horizontal transport mechanisms of BC with a focus on the role of wet removal. Between the northwestern Norwegian coast and the Svalbardmore » archipelago, the Falcon aircraft sampled plumes with enhanced CO concentrations up to 200 ppbv and BC mixing ratios up to 25 ng kg –1. During transport to the Arctic region, a large fraction of BC particles are scavenged by two wet deposition processes, namely wet removal by large-scale precipitation and removal in wet convective updrafts, with both processes contributing almost equally to the total accumulated deposition of BC. Our results underline that applying a finer horizontal resolution (40 instead of 100 km) improves the model performance, as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TE BC) in biomass burning plumes was larger (60 %), because it was impacted by small accumulated precipitation along trajectory (1 mm). In contrast TE BC was small (< 30 %) and accumulated precipitation amounts were larger (5–10 mm) in plumes influenced by urban anthropogenic sources and flaring activities in northern Russia, resulting in transport to lower altitudes. TE BC due to large-scale precipitation is responsible for a sharp meridional gradient in the distribution of BC concentrations. Wet removal in cumulus clouds is the cause of modeled vertical gradient of TE BC, especially in the mid-latitudes, reflecting the distribution of convective precipitation, but is dominated in the Arctic region by the large-scale wet removal associated with the formation of stratocumulus clouds in the planetary boundary layer (PBL) that produce frequent drizzle.« less

Cross-polar transport and scavenging of Siberian aerosols containing black carbon during the 2012 ACCESS summer campaign

DOE PAGES

Raut, Jean -Christophe; Marelle, Louis; Fast, Jerome D.; ...

2017-09-15

During the ACCESS airborne campaign in July 2012, extensive boreal forest fires resulted in significant aerosol transport to the Arctic. A 10-day episode combining intense biomass burning over Siberia and low-pressure systems over the Arctic Ocean resulted in efficient transport of plumes containing black carbon (BC) towards the Arctic, mostly in the upper troposphere (6–8 km). Here, a combination of in situ observations (DLR Falcon aircraft), satellite analysis and WRF-Chem simulations is used to understand the vertical and horizontal transport mechanisms of BC with a focus on the role of wet removal. Between the northwestern Norwegian coast and the Svalbardmore » archipelago, the Falcon aircraft sampled plumes with enhanced CO concentrations up to 200 ppbv and BC mixing ratios up to 25 ng kg –1. During transport to the Arctic region, a large fraction of BC particles are scavenged by two wet deposition processes, namely wet removal by large-scale precipitation and removal in wet convective updrafts, with both processes contributing almost equally to the total accumulated deposition of BC. Our results underline that applying a finer horizontal resolution (40 instead of 100 km) improves the model performance, as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TE BC) in biomass burning plumes was larger (60 %), because it was impacted by small accumulated precipitation along trajectory (1 mm). In contrast TE BC was small (< 30 %) and accumulated precipitation amounts were larger (5–10 mm) in plumes influenced by urban anthropogenic sources and flaring activities in northern Russia, resulting in transport to lower altitudes. TE BC due to large-scale precipitation is responsible for a sharp meridional gradient in the distribution of BC concentrations. Wet removal in cumulus clouds is the cause of modeled vertical gradient of TE BC, especially in the mid-latitudes, reflecting the distribution of convective precipitation, but is dominated in the Arctic region by the large-scale wet removal associated with the formation of stratocumulus clouds in the planetary boundary layer (PBL) that produce frequent drizzle.« less

Transport properties for a mixture of the ablation products C, C2, and C3

NASA Technical Reports Server (NTRS)

Biolsi, L.; Fenton, J.; Owenson, B.

1981-01-01

The ablation of carbon-phenolic heat shields upon entry into the atmosphere of one of the outer planets leads to the injection of large amounts of C, C2, and C3 into the shock layer. These species must be included in the calculation of transport properties in the shock layer. The kinetic theory of gases has been used to obtain accurate results for the transport properties of monatomic carbon. The Hulburt-Hirschelder potential, the most accurate general purpose atom-atom potential for states with an attractive minimum, was used to represent such states and repulsive states were represented by fitting quantum mechanical potential energy curves with the exponential repulsive potential. These results were orientation averaged according to the peripheral force model to obtain transport collision integrals for the C-C2 and C2-C2 interaction. Results for C3 were obtained by ignoring the presence of the central carbon atom. The thermal conductivity, viscosity, and diffusion coefficients for pure C, C2, and C3, and for mixtures of these gases, were then calculated from 1000 K - 25,000 K.

Chemically generated convective transport in microfluidic system

NASA Astrophysics Data System (ADS)

Shklyaev, Oleg; Das, Sambeeta; Altemose, Alicia; Shum, Henry; Balazs, Anna; Sen, Ayusman

High precision manipulation of small volumes of fluid, containing suspended micron sized objects like cells, viruses, and large molecules, is one of the main goals in designing modern lab-on-a-chip devices which can find a variety of chemical and biological applications. To transport the cargo toward sensing elements, typical microfluidic devices often use pressure driven flows. Here, we propose to use enzymatic chemical reactions which decompose reagent into less dense products and generate flows that can transport particles. Density variations that lead to flow in the assigned direction are created between the place where reagent is fed into the solution and the location where it is decomposed by enzymes attached to the surface of the microchannel. When the reagent is depleted, the fluid motion stops and particles sediment to the bottom. We demonstrate how the choice of chemicals, leading to specific reaction rates, can affect the transport properties. In particular, we show that the intensity of the fluid flow, the final location of cargo, and the time for cargo delivery are controlled by the amount and type of reagent in the system.

14 CFR 250.5 - Amount of denied boarding compensation for passengers denied boarding involuntarily.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS OVERSALES § 250.5 Amount of denied... transportation benefit and receive the cash/check payment; and (3) The carrier fully discloses all material restrictions, including but not limited to, administrative fees, advance purchase or capacity restrictions, and...

14 CFR 250.5 - Amount of denied boarding compensation for passengers denied boarding involuntarily.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS OVERSALES § 250.5 Amount of denied... transportation benefit and receive the cash/check payment; and (3) The carrier fully discloses all material restrictions, including but not limited to, administrative fees, advance purchase or capacity restrictions, and...

14 CFR 250.5 - Amount of denied boarding compensation for passengers denied boarding involuntarily.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS OVERSALES § 250.5 Amount of denied... transportation benefit and receive the cash/check payment; and (3) The carrier fully discloses all material restrictions, including but not limited to, administrative fees, advance purchase or capacity restrictions, and...

49 CFR 31.31 - Determining the amount of penalties and assessments.

Code of Federal Regulations, 2012 CFR

2012-10-01

... loss; (7) The potential or actual impact of the misconduct upon national defense, public health or... assessments. 31.31 Section 31.31 Transportation Office of the Secretary of Transportation PROGRAM FRAUD CIVIL REMEDIES § 31.31 Determining the amount of penalties and assessments. (a) In determining an appropriate...

49 CFR 31.31 - Determining the amount of penalties and assessments.

Code of Federal Regulations, 2010 CFR

2010-10-01

... loss; (7) The potential or actual impact of the misconduct upon national defense, public health or... assessments. 31.31 Section 31.31 Transportation Office of the Secretary of Transportation PROGRAM FRAUD CIVIL REMEDIES § 31.31 Determining the amount of penalties and assessments. (a) In determining an appropriate...

49 CFR 31.31 - Determining the amount of penalties and assessments.

Code of Federal Regulations, 2013 CFR

2013-10-01

... loss; (7) The potential or actual impact of the misconduct upon national defense, public health or... assessments. 31.31 Section 31.31 Transportation Office of the Secretary of Transportation PROGRAM FRAUD CIVIL REMEDIES § 31.31 Determining the amount of penalties and assessments. (a) In determining an appropriate...

49 CFR 31.31 - Determining the amount of penalties and assessments.

Code of Federal Regulations, 2011 CFR

2011-10-01

... loss; (7) The potential or actual impact of the misconduct upon national defense, public health or... assessments. 31.31 Section 31.31 Transportation Office of the Secretary of Transportation PROGRAM FRAUD CIVIL REMEDIES § 31.31 Determining the amount of penalties and assessments. (a) In determining an appropriate...

49 CFR 31.31 - Determining the amount of penalties and assessments.

Code of Federal Regulations, 2014 CFR

2014-10-01

... loss; (7) The potential or actual impact of the misconduct upon national defense, public health or... assessments. 31.31 Section 31.31 Transportation Office of the Secretary of Transportation PROGRAM FRAUD CIVIL REMEDIES § 31.31 Determining the amount of penalties and assessments. (a) In determining an appropriate...

Sediment Transportation Induced by Deep-Seated Landslides in a Debris Flow Basin in Taiwan

NASA Astrophysics Data System (ADS)

Lin, Meei Ling; Chen, Te Wei; Chen, Yong Sheng; Sin Jhuang, Han

2016-04-01

Typhoon Morakot brought huge amount of rainfall to the southern Taiwan in 2009 and caused severe landslides and debris flow hazard. After Typhoon Morakot, it was found that the volume of sediment transported by the debris flow and its effects on the affected area were much more significant compared to previous case history, which may due to the huge amount of rainfall causing significant deep-seated landslides in the basin. In this study, the effects and tendency of the sediment transportation in a river basin following deep-seated landslides caused by typhoon Morakot were evaluated. We used LiDAR, DEM, and aerial photo to identify characteristics of deep-seated landslides in a debris flow river basin, KSDF079 in Liuoguey District, Kaohsiung City, Taiwan. Eight deep-seated landslides were identified in the basin. To estimate the potential landslide volume associated with the deep-seated landslides, the stability analysis was conducted to locate the critical sliding surface, and the potential landside volume was estimated based on the estimation equation proposed by the International Geotechnical Societies' UNESCO Working Party on World Landslide Inventory (WP/WLI, 1990). The total potential landslide volume of the eight deep-seated landslides in KSDF079 basin was about 28,906,856 m3. Topographic analysis was performed by using DEM before and LiDAR derived DEM after typhoon Morakot to calculate the landslide volume transported. The result of erosion volume and deposition volume lead to a run out volume of 5,832,433 m3. The results appeared to consist well with the field condition and aerial photo. Comparing the potential landslide volume and run out volume of eight deep-seated landslides, it was found that the remaining potential landslide volume was about 80%. Field investigation and topographic analysis of the KSDF079 debris flow revealed that a significant amount of sediment deposition remained in the river channel ranging from the middle to the downstream section of the channel, and the channel has been widen. Such large proportion of landslide volume remained in the basin on deep-seated landslide scars and debris flow river channel would likely to cause further debris transportation in the future events. The stability analysis used in this study provided a feasible method and satisfactory results for estimating sediment volume transportation associated with the deep-seated landslides in the study area. Combination of the stability analysis results and the topographic analysis provided estimation of sediment transportation caused by the deep-seated landslides, and trend variation of further sediment transport of the basin, which could provide vital information for hazard mitigation. Keyword: deep-seated landslide, sediment transport, DEM, LiDAR, stability analysis

Nutrient transports in the Baltic Sea - results from a 30-year physical-biogeochemical reanalysis

NASA Astrophysics Data System (ADS)

Liu, Ye; Meier, H. E. Markus; Eilola, Kari

2017-04-01

Long-term oxygen and nutrient transports in the Baltic Sea are reconstructed using the Swedish Coastal and Ocean Biogeochemical model (SCOBI) coupled to the Rossby Centre Ocean model (RCO). Two simulations with and without data assimilation covering the period 1970-1999 are carried out. Here, the weakly coupled scheme with the Ensemble Optimal Interpolation (EnOI) method is adopted to assimilate observed profiles in the reanalysis system. The reanalysis shows considerable improvement in the simulation of both oxygen and nutrient concentrations relative to the free run. Further, the results suggest that the assimilation of biogeochemical observations has a significant effect on the simulation of the oxygen-dependent dynamics of biogeochemical cycles. From the reanalysis, nutrient transports between sub-basins, between the coastal zone and the open sea, and across latitudinal and longitudinal cross sections are calculated. Further, the spatial distributions of regions with nutrient import or export are examined. Our results emphasize the important role of the Baltic proper for the entire Baltic Sea, with large net transport (export minus import) of nutrients from the Baltic proper into the surrounding sub-basins (except the net phosphorus import from the Gulf of Riga and the net nitrogen import from the Gulf of Riga and Danish Straits). In agreement with previous studies, we found that the Bothnian Sea imports large amounts of phosphorus from the Baltic proper that are retained in this sub-basin. For the calculation of sub-basin budgets, the location of the lateral borders of the sub-basins is crucial, because net transports may change sign with the location of the border. Although the overall transport patterns resemble the results of previous studies, our calculated estimates differ in detail considerably.

Rainfall, runoff and sediment transport in a Mediterranean mountainous catchment.

PubMed

Tuset, J; Vericat, D; Batalla, R J

2016-01-01

The relation between rainfall, runoff, erosion and sediment transport is highly variable in Mediterranean catchments. Their relation can be modified by land use changes and climate oscillations that, ultimately, will control water and sediment yields. This paper analyses rainfall, runoff and sediment transport relations in a meso-scale Mediterranean mountain catchment, the Ribera Salada (NE Iberian Peninsula). A total of 73 floods recorded between November 2005 and November 2008 at the Inglabaga Sediment Transport Station (114.5 km(2)) have been analysed. Suspended sediment transport and flow discharge were measured continuously. Rainfall data was obtained by means of direct rain gauges and daily rainfall reconstructions from radar information. Results indicate that the annual sediment yield (2.3 t km(-1) y(-1) on average) and the flood-based runoff coefficients (4.1% on average) are low. The Ribera Salada presents a low geomorphological and hydrological activity compared with other Mediterranean mountain catchments. Pearson correlations between rainfall, runoff and sediment transport variables were obtained. The hydrological response of the catchment is controlled by the base flows. The magnitude of suspended sediment concentrations is largely correlated with flood magnitude, while sediment load is correlated with the amount of direct runoff. Multivariate analysis shows that total suspended load can be predicted by integrating rainfall and runoff variables. The total direct runoff is the variable with more weight in the equation. Finally, three main hydro-sedimentary phases within the hydrological year are defined in this catchment: (a) Winter, where the catchment produces only water and very little sediment; (b) Spring, where the majority of water and sediment is produced; and (c) Summer-Autumn, when little runoff is produced but significant amount of sediments is exported out of the catchment. Results show as land use and climate change may have an important role in modifying the cycles of water and sediment yields in Mediterranean mountain catchments. Copyright © 2015 Elsevier B.V. All rights reserved.

Expression of lactate transporters MCT1, MCT2 and CD147 in the red blood cells of three horse breeds: Finnhorse, Standardbred and Thoroughbred.

PubMed

Mykkänen, A K; Pösö, A R; McGowan, C M; McKane, S A

2010-11-01

In exercising horses, up to 50% of blood lactate is taken up into red blood cells (RBCs). Lactate transporter proteins MCT1, MCT2 and CD147 (an ancillary protein for MCT1) are expressed in the equine RBC membrane. In Standardbreds (SB), lactate transport activity is bimodally distributed and correlates with the amount of MCT1 and CD147. About 75% of SB studied have high lactate transport activity in RBCs. In other breeds, the distribution of lactate transport activity is unknown. To study whether similar bimodal distribution of MCT1 and CD147 is present also in the racing Finnhorse (FH) and Thoroughbred (TB) as in the SB and to study the distribution of MCT2 in all 3 breeds and to determine if there is a connection between MCT expression and performance markers in TB racehorses. Venous blood samples were taken from 118 FHs, 98 TBs and 44 SBs. Red blood cell membranes were purified and MCT1, MCT2 and CD147 measured by western blot. The amount of transporters was compared with TB performance markers. In TBs, the distribution of MCT1 was bimodal and in all breeds distribution of MCT2 unimodal. The amount of CD147 was clearly bimodal in FH and SB, with 85 and 82% expressing high amounts of CD147. In TBs, 88% had high expression of CD147 and 11% low expression, but one horse showed intermediate expression not apparent in FH or SB. Performance markers did not correlate with the amount of MCT1, MCT2 or CD147. High lactate transport activity was present in all 3 racing breeds, with the greatest proportion in the TB, followed by the racing FH, then SB. There was no significant statistical correlation found between lactate transporters in RBC membrane and markers of racing performance in the TB. © 2010 EVJ Ltd.

Phosphorus and groundwater: Establishing links between agricultural use and transport to streams

USGS Publications Warehouse

Domagalski, Joseph L.; Johnson, Henry

2012-01-01

Leaching of applied fertilizer and surface runoff of phosphorus from the soil can contribute to excess growth of algae in downstream water bodies, a condition known as eutrophication. Excessive amounts of algae in eutrophic water bodies can cause large daily changes in the amount of dissolved oxygen in the water because oxygen concentrations tend to be high during daylight hours as a result of photosynthetic activity but then decrease at night. Low concentrations of dissolved oxygen can stress or kill sensitive species living in the water. This study examined concentrations and movement of phosphorus in the soils and groundwater in five agricultural settings across the United States characterized by differences in soil geochemistry, climate, irrigation usage, and cropping systems to assess potential phosphorus movement in the soil and groundwater under common agricultural conditions. The study design included assessment of a variety of agricultural practices, especially cropping patterns and irrigation, so that the factors that contribute to phosphorus movement to groundwater, or sequestration of the phosphorus to soil could be compared and examined. This type of information could potentially be used to formulate best management practices to limit the transport of phosphorus from the agricultural fields.

United States Marine Corps light armored vehicle ride and shock mobility test

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

Casterlow, D.; Salami, M.R.

1995-06-01

Mobility on the battlefield has been a major concern since the beginning of modern warfare. How do you transport troops more efficiently, in the least amount of time, from place to place on the battlefield? In the early days of World War I, came the invention of the tank and different types of armored vehicles. These vehicles were very slow and moved over a limited variety of terrain. Today, with faster, more powerful armored vehicles, extended testing is being done to determine their ability to move over various types of terrain encountered on the modern battlefield. Along with this testing,more » studies are performed which take into account the effect of the ride on soldiers. It has been proven that a sustained rough ride, of over 6 watts of vertical absorbed power, will affect a soldier`s ability to fight, once he reaches the battle. As a result, different vehicles go through testing in various off-road terrain to determine which one can handle the roughest terrain, at the fastest speed, while transporting troops, without imposing large amounts of human vibration on the soldiers. This is done through ride and shock mobility tests.« less

Volcanic eruptions; energy and size

USGS Publications Warehouse

de la Cruz-Reyna, S.

1991-01-01

The Earth is a dynamic planet. Many different processes are continuously developing, creating a delicate balance between the energy stored and generated in its interior and the heat lost into space. The heat in continuously transferred through complex self-regulating convection mechanisms on a planetary scale. The distribution of terrestrial heat flow reveals some of the fine structure of the energy transport mechanisms in the outer layers of the Earth. Of these mechanisms in the outer layers of the Earth. Of these mechanisms, volcanism is indeed the most remarkable, for it allows energy to be transported in rapid bursts to the surface. In order to maintain the subtle balance of the terrestrial heat machine, one may expect that some law or principle restricts the ways in which these volcanic bursts affect the overall energy transfer of the Earth. For instance, we know that the geothermal flux of the planet amounts to 1028 erg/year. On the other hand, a single large event like the Lava Creek Tuff eruption that formed Yellowstone caldera over half a million years ago may release the same amount of energy in a very small area, over a short period of time. 

Risk assessment of virus infections in the Oder estuary (southern Baltic) on the basis of spatial transport and virus decay simulations.

PubMed

Schernewski, G; Jülich, W D

2001-05-01

The large Oder (Szczecin) Lagoon (687 km2) at the German-Polish border, close to the Baltic Sea, suffers from severe eutrophication and water quality problems due to high discharge of water, nutrients and pollutants by the river Oder. Sewage treatment around the lagoon has been very much improved during the last years, but large amounts of sewage still enter the Oder river. Human pathogenic viruses generally can be expected in all surface waters that are affected by municipal sewage. There is an increasing awareness that predisposed persons can be infected by a few infective units or even a single active virus. Another new aspect is, that at least polioviruses attached to suspended particles can be infective for weeks and therefore be transported over long distances. Therefore, the highest risk of virus inputs arise from the large amounts of untreated sewage of the city of Szczecin (Poland), which are released into the river Oder and transported to the lagoon and the Baltic Sea. Summer tourism is the most important economical factor in this coastal region and further growth is expected. Human pathogenic viruses might be a serious problem for bathing water quality and sustainable summer tourism. The potential hazard of virus infections along beaches and shores of the Oder lagoon and adjacent parts of the Baltic Sea is evaluated on the basis of model simulations and laboratory results. We used two scenarios for the Older Lagoon considering free viruses and viruses attached to suspended particle matter. The spatial impact of the average virus release in the city of Szczecin during summer (bathing period) was simulated with a hydrodynamic and particle tracking model. Simulations suggest that due to fast inactivation, free viruses in the water represent a risk only in the river and near the river mouth. On the other hand, viruses attached to suspended matter can affect large areas of the eastern, Polish part of the lagoon (Grosses Haff). At the same time the accumulation of viruses on suspended particulate matter increases the likelihood of an infection after incorporation of such a particle. There is no evidence, that there is a risk of virus infections in the western part of the lagoon (Kleines Haff) or along the outer Baltic Sea coast.

Flux growth in a horizontal configuration: An analog to vapor transport growth

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

Yan, J. -Q.; Sales, B. C.; Susner, M. A.

Flux growth of single crystals is normally performed in a vertical configuration with an upright refractory container holding the flux melt. At high temperatures, flux dissolves the charge, forming a homogeneous solution before nucleation and growth of crystals takes place under proper supersaturation generated by cooling or evaporating the flux. In this paper, we report flux growth in a horizontal configuration with a temperature gradient along the horizontal axis: a liquid transport growth analogous to the vapor transport technique. In a typical liquid transport growth, the charge is kept at the hot end of the refractory container and the fluxmore » melt dissolves the charge and transfers it to the cold end. Once the concentration of charge is above the solubility limit at the cold end, the thermodynamically stable phase nucleates and grows. Compared to the vertical flux growth, the liquid transport growth can provide a large quantity of crystals in a single growth since the charge/flux ratio is not limited by the solubility limit at the growth temperature. This technique is complementary to the vertical flux growth and can be considered when a large amount of crystals is needed but the yield from the conventional vertical flux growth is limited. Finally, we applied this technique to the growth of IrSb 3, Mo 3Sb 7, and MnBi from self-flux, and the growth of FeSe, CrTe 3, NiPSe 3, FePSe 3, CuInP 2S 6, RuCl 3, and OsCl 4 from a halide flux.« less

Flux growth in a horizontal configuration: An analog to vapor transport growth

DOE PAGES

Yan, J. -Q.; Sales, B. C.; Susner, M. A.; ...

2017-07-05

Flux growth of single crystals is normally performed in a vertical configuration with an upright refractory container holding the flux melt. At high temperatures, flux dissolves the charge, forming a homogeneous solution before nucleation and growth of crystals takes place under proper supersaturation generated by cooling or evaporating the flux. In this paper, we report flux growth in a horizontal configuration with a temperature gradient along the horizontal axis: a liquid transport growth analogous to the vapor transport technique. In a typical liquid transport growth, the charge is kept at the hot end of the refractory container and the fluxmore » melt dissolves the charge and transfers it to the cold end. Once the concentration of charge is above the solubility limit at the cold end, the thermodynamically stable phase nucleates and grows. Compared to the vertical flux growth, the liquid transport growth can provide a large quantity of crystals in a single growth since the charge/flux ratio is not limited by the solubility limit at the growth temperature. This technique is complementary to the vertical flux growth and can be considered when a large amount of crystals is needed but the yield from the conventional vertical flux growth is limited. Finally, we applied this technique to the growth of IrSb 3, Mo 3Sb 7, and MnBi from self-flux, and the growth of FeSe, CrTe 3, NiPSe 3, FePSe 3, CuInP 2S 6, RuCl 3, and OsCl 4 from a halide flux.« less

Simulation of Space Charge Dynamic in Polyethylene Under DC Continuous Electrical Stress

NASA Astrophysics Data System (ADS)

Boukhari, Hamed; Rogti, Fatiha

2016-10-01

The space charge dynamic plays a very important role in the aging and breakdown of polymeric insulation materials under high voltage. This is due to the intensification of the local electric field and the attendant chemical-mechanical effects in the vicinity around the trapped charge. In this paper, we have investigated the space charge dynamic in low-density polyethylene under high direct-current voltage, which is evaluated by experimental conditions. The evaluation is on the basis of simulation using a bipolar charge transport model consisting of charge injection, transports, trapping, detrapping, and recombination phenomena. The theoretical formulation of the physical problem is based on the Poisson, the continuity, and the transport equations. Numerical results provide temporal and local distributions of the electric field, the space charge density for the different kinds of charges (net charge density, mobile and trapped of electron density, mobile hole density), conduction and displacement current densities, and the external current. The result shows the appearance of the negative packet-like space charge with a large amount of the bulk under the dc electric field of 100 kV/mm, and the induced distortion of the electric field is largely near to the anode, about 39% higher than the initial electric field applied.

Electrical transport and optical band gap of NiFe2Ox thin films

NASA Astrophysics Data System (ADS)

Bougiatioti, Panagiota; Manos, Orestis; Klewe, Christoph; Meier, Daniel; Teichert, Niclas; Schmalhorst, Jan-Michael; Kuschel, Timo; Reiss, Günter

2017-12-01

We fabricated NiFe2Ox thin films on MgAl2O4(001) by reactive dc magnetron co-sputtering varying the oxygen partial pressure. The fabrication of a material with a variable oxygen deficiency leads to controllable electrical and optical properties which are beneficial for the investigations of the transport phenomena and could, therefore, promote the use of such materials in spintronic and spin caloritronic applications. We used several characterization techniques to investigate the film properties, focusing on their structural, magnetic, electrical, and optical properties. From the electrical resistivity, we obtained the conduction mechanisms that govern the systems in the high and low temperature regimes. We further extracted low thermal activation energies which unveil extrinsic transport mechanisms. The thermal activation energy decreases in the less oxidized samples revealing the pronounced contribution of a large amount of electronic states localized in the band gap to the electrical conductivity. The Hall coefficient is negative and decreases with increasing conductivity as expected for n-type conduction, while the Hall- and the drift mobilities show a large difference. The optical band gaps were determined via ultraviolet-visible spectroscopy. They follow a similar trend as the thermal activation energies, with lower band gap values in the less oxidized samples.

[Professional driving and safety, a target for occupational medicine].

PubMed

Rosso, G L; Zanelli, R; Bruno, Santina; Feola, M; Bobbio, M

2007-01-01

Road traffic injuries constitute one of the main causes of death and disability in Italy and in the European Union. Occupational medicine should pay special attention to the field of road transport because every year a large number of road accidents occur with fatal outcomes. Via health surveillance the occupational physician can play an important role in the prevention of such events. The aim of the article is to summarize the results of the most recent studies on the main risk factors for road transport safety and discuss possible strategies of health surveillance, according to the recent indications of the European Agency for Safety and Health at Work, Bilbao. A review of the literature was made. The scientific literature provides a large amount of interesting information on the most important risk factors for road accidents, such as drinking and drug abuse, sleepiness and other medical conditions, or excessive speed. The presence of numerous and varied hazards for road transport safety requires, as suggested by the Bilbao Agency, the adoption of occupational health measures, including risk assessment, health education, technical and environmental prevention, health surveillance and clinical interventions (diagnosis and rehabilitation of occupational accidents). Moreover, the paper stresses the need to strengthen collaboration between occupational health physicians and other medical specialists.

Dynamical analysis of extreme precipitation in the US northeast based on large-scale meteorological patterns

NASA Astrophysics Data System (ADS)

Agel, Laurie; Barlow, Mathew; Colby, Frank; Binder, Hanin; Catto, Jennifer L.; Hoell, Andrew; Cohen, Judah

2018-05-01

Previous work has identified six large-scale meteorological patterns (LSMPs) of dynamic tropopause height associated with extreme precipitation over the Northeast US, with extreme precipitation defined as the top 1% of daily station precipitation. Here, we examine the three-dimensional structure of the tropopause LSMPs in terms of circulation and factors relevant to precipitation, including moisture, stability, and synoptic mechanisms associated with lifting. Within each pattern, the link between the different factors and extreme precipitation is further investigated by comparing the relative strength of the factors between days with and without the occurrence of extreme precipitation. The six tropopause LSMPs include two ridge patterns, two eastern US troughs, and two troughs centered over the Ohio Valley, with a strong seasonality associated with each pattern. Extreme precipitation in the ridge patterns is associated with both convective mechanisms (instability combined with moisture transport from the Great Lakes and Western Atlantic) and synoptic forcing related to Great Lakes storm tracks and embedded shortwaves. Extreme precipitation associated with eastern US troughs involves intense southerly moisture transport and strong quasi-geostrophic forcing of vertical velocity. Ohio Valley troughs are associated with warm fronts and intense warm conveyor belts that deliver large amounts of moisture ahead of storms, but little direct quasi-geostrophic forcing. Factors that show the largest difference between days with and without extreme precipitation include integrated moisture transport, low-level moisture convergence, warm conveyor belts, and quasi-geostrophic forcing, with the relative importance varying between patterns.

Catalytic fast pyrolysis of lignocellulosic biomass

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

Liu, Changjun; Wang, Huamin; Karim, Ayman M.

2014-11-21

Increasing energy demand, especially in the transportation sector, and soaring CO2 emissions necessitate the exploitation of renewable sources of energy. Despite the large variety of new energy Q3 carriers, liquid hydrocarbon still appears to be the most attractive and feasible form of transportation fuel taking into account the energy density, stability and existing infrastructure. Biomass is an abundant, renewable source of energy; however, utilizing it in a cost-effective way is still a substantial challenge. Lignocellulose is composed of three major biopolymers, namely cellulose, hemicellulose and lignin. Fast pyrolysis of biomass is recognized as an efficient and feasible process to selectivelymore » convert lignocellulose into a liquid fuel—bio-oil. However bio-oil from fast pyrolysis contains a large amount of oxygen, distributed in hundreds of oxygenates. These oxygenates are the cause of many negative properties, such as low heating values, high corrosiveness, high viscosity, and instability; they also greatly Q4 limit the application of bio-oil particularly as transportation fuel. Hydrocarbons derived from biomass are most attractive because of their high energy density and compatibility with the existing infrastructure. Thus, converting lignocellulose into transportation fuels via catalytic fast pyrolysis has attracted much attention. Many studies related to catalytic fast pyrolysis of biomass have been published. The main challenge of this process is the development of active and stable catalysts that can deal with a large variety of decomposition intermediates from lignocellulose. This review starts with the current understanding of the chemistry in fast pyrolysis of lignocellulose and focuses on the development of catalysts in catalytic fast pyrolysis. Recent progress in the experimental studies on catalytic fast pyrolysis of biomass is also summarized with the emphasis on bio-oil yields and quality.« less

Bioaccessibility, uptake, and transport of carotenoids from peppers (Capsicum spp.) using the coupled in vitro digestion and human intestinal Caco-2 cell model.

PubMed

O'Sullivan, Laurie; Jiwan, Marvin A; Daly, Trevor; O'Brien, Nora M; Aherne, S Aisling

2010-05-12

Spanish bell peppers (Capsicum annuum L.) and chili peppers sourced from Kenya and Turkey were analyzed for their carotenoid content, bioaccessibility, and bioavailability. The order of total carotenoid content in peppers and their respective micelles was red > green > yellow. In terms of cellular carotenoid transport as a percentage of original food and micelle content, the order was yellow peppers > green > red; however, the opposite trend was seen for the actual amount of total carotenoids transported by Caco-2 cells. Although lutein was generally the most abundant carotenoid in the micelles (496.3-1565.7 microg 100 g(-1)), cellular uptake and transport of beta-carotene were the highest, 8.3-31.6 and 16.8-42.7%, respectively. Hence, the actual amount of carotenoids present in the original food and respective micelles seems to reflect the amount transported by Caco-2 cells. Therefore, color influenced the carotenoid profile, bioaccessibility, and bioavailability of carotenoids rather than pepper type.

Progress toward an explicit mechanistic model for the light-driven pump, bacteriorhodopsin

NASA Technical Reports Server (NTRS)

Lanyi, J. K.

1999-01-01

Recent crystallographic information about the structure of bacteriorhodopsin and some of its photointermediates, together with a large amount of spectroscopic and mutational data, suggest a mechanistic model for how this protein couples light energy to the translocation of protons across the membrane. Now nearing completion, this detailed molecular model will describe the nature of the steric and electrostatic conflicts at the photoisomerized retinal, as well as the means by which it induces proton transfers in the two half-channels leading to the two membrane surfaces, thereby causing unidirectional, uphill transport.

It's not just how high; it's how clean: Sampling the spring 2001 flood in the Upper Mississippi River Basin

USGS Publications Warehouse

Patterson, Glenn; Kolpin, Dana W.; Kalkhoff, Stephen J.; Lee, Kathy E.; Schnoebelen, Douglas J.; Barnes, Kimberlee K.; Coupe, Richard H.

2001-01-01

Floods can cause water-quality problems because of the large amounts of contaminants (sediment, nutrients, pesticides, and bacteria) that can be transported by floodwaters. during the flood on the Upper Mississippi River in 2001, water-quality and water-quality data were collected during near-record streamflow. This is the first time that samples for determining organic wastewater contaminants (pharmaceuticals, hormones, and industrial/household use compounds) and pesticide degradates have been collected during a flood of this magnitude.

Bed load transport and boundary roughness changes as competing causes of hysteresis in the relationship between river discharge and seismic amplitude recorded near a steep mountain stream

NASA Astrophysics Data System (ADS)

Roth, Danica L.; Finnegan, Noah J.; Brodsky, Emily E.; Rickenmann, Dieter; Turowski, Jens M.; Badoux, Alexandre; Gimbert, Florent

2017-05-01

Hysteresis in the relationship between bed load transport and river stage is a well-documented phenomenon with multiple known causes. Consequently, numerous studies have interpreted hysteresis in the relationship between seismic ground motion near rivers and some measure of flow strength (i.e., discharge or stage) as the signature of bed load transport. Here we test this hypothesis in the Erlenbach stream (Swiss Prealps) using a metric to quantitatively compare hysteresis in seismic data with hysteresis recorded by geophones attached beneath steel plates within the streambed, a well-calibrated proxy for direct sediment transport measurements. We find that while both the geophones and seismometers demonstrate hysteresis, the magnitude and direction of hysteresis are not significantly correlated between these data, indicating that the seismic signal at this site is primarily reflecting hysteresis in processes other than sediment transport. Seismic hysteresis also does not correlate significantly with the magnitude of sediment transport recorded by the geophones, contrary to previous studies' assumptions. We suggest that hydrologic sources and changes in water turbulence, for instance due to evolving boundary conditions at the bed, rather than changes in sediment transport rates, may sometimes contribute to or even dominate the hysteresis observed in seismic amplitudes near steep mountain rivers.