Academic literature on the topic 'Conservative and non-conservative environmental tracers'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Conservative and non-conservative environmental tracers.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Conservative and non-conservative environmental tracers"
1
Champ, D. R., and J. Schroeter. "Bacterial Transport in Fractured Rock – A Field-Scale Tracer Test at the Chalk River Nuclear Laboratories." Water Science and Technology 20, no. 11-12 (November 1, 1988): 81–87. http://dx.doi.org/10.2166/wst.1988.0269.
Full textAbstract:
The potential for transport of bacteria by groundwater in fractured crystalline rock was assessed in a series of field-scale tracer tests. The breakthrough curves for injected Escherichla coll and “non-reactive” particle tracers were compared with those for conservative inorganic and radioactive tracers. Rapid transport, relative to the conservative tracers, of both bacteria and non-reactive particles was observed. The first appearance of both was with, or slightly before, the conservative tracers for water movement. Removal of the bacteria and particles by filtration processes occurred and was quantified through the calculation of filter factors. The filtration process in this fracture system is similar to that found in a gravel aquifer. From the results we can conclude that particulate contaminants can be very rapidly transported in fracture systems and that continuing sources of contamination could lead to relatively high local concentrations of particulate contaminants compared with the average at any given distance from the source. It was also concluded that the use of traditional conservative tracers, for water movement, to assess the potential for movement of particulate contaminants could lead to significant underestimates of exposure to particulate contaminants due to consumption of water from water recovery wells located in fractured media.
2
Gresch, M., D. Braun, and W. Gujer. "The role of the flow pattern in wastewater aeration tanks." Water Science and Technology 61, no. 2 (January 1, 2010): 407–14. http://dx.doi.org/10.2166/wst.2010.803.
Full textAbstract:
Reactor hydraulics is one of the key factors for plant performance and plant control. The residence time distribution is a good but limited indicator of reactor hydraulics. A more detailed view is obtained by direct observations within the reactor. Two different techniques (conservative tracer, reactive tracer) are discussed to detect major anomalies in the flow field of a wastewater aeration tank. Experiments with conservative tracers give valuable information over a very limited period of time making the analysis of the flow field difficult. On the other hand, reactive tracers can be monitored long term which helps identifying the flow pattern provided that a high spatial and temporal resolution of the measurements is applied. Experimental data is used to determine the structure and the parameters of a compartment model that corresponds well with the measurements.
3
Stephenson, Ruth, Craig Sheridan, and Uwe Kappelmeyer. "A curve-shift technique for the use of non-conservative organic tracers in constructed wetlands." Science of The Total Environment 752 (January 2021): 141818. http://dx.doi.org/10.1016/j.scitotenv.2020.141818.
Full text
4
Lizaga, Ivan, Borja Latorre, Leticia Gaspar, and Ana Navas. "Consensus ranking as a method to identify non-conservative and dissenting tracers in fingerprinting studies." Science of The Total Environment 720 (June 2020): 137537. http://dx.doi.org/10.1016/j.scitotenv.2020.137537.
Full text
5
Eatough, D. J., C. L. Benner, H. Tang, V. Landon, G. Richards, F. M. Caka, J. Crawford, E. A. Lewis, L. D. Hansen, and N. L. Eatough. "The chemical composition of environmental tobacco smoke III. Identification of conservative tracers of environmental tobacco smoke." Environment International 15, no. 1-6 (January 1989): 19–28. http://dx.doi.org/10.1016/0160-4120(89)90005-6.
Full text
6
von Gunten, U., M. Elovitz, and H. P. Kaiser. "Calibration of full-scale ozonation systems with conservative and reactive tracers." Journal of Water Supply: Research and Technology—AQUA 48, no. 6 (September 1999): 250–56. http://dx.doi.org/10.2166/aqua.1999.0027.
Full text
7
Lemke, Dennis, Pierre-André Schnegg, Marc Schwientek, Karsten Osenbrück, and Olaf A. Cirpka. "On-line fluorometry of multiple reactive and conservative tracers in streams." Environmental Earth Sciences 69, no. 2 (February 27, 2013): 349–58. http://dx.doi.org/10.1007/s12665-013-2305-3.
Full text
8
Barberá, J. A., B. Andreo, and C. Almeida. "Using non-conservative tracers to characterise karstification processes in the Merinos-Colorado-Carrasco carbonate aquifer system (southern Spain)." Environmental Earth Sciences 71, no. 2 (September 7, 2013): 585–99. http://dx.doi.org/10.1007/s12665-013-2754-8.
Full text
9
Puente, C. E., O. Robayo, M. C. Díaz, and B. Sivakumar. "A fractal-multifractal approach to groundwater contamination. 1. Modeling conservative tracers at the Borden site." Stochastic Environmental Research and Risk Assessment 15, no. 5 (October 2001): 357–71. http://dx.doi.org/10.1007/pl00009791.
Full text
10
Chen, Hao, Fu Li Chen, Yong Ying Zhu, Ming Zeng, Chen Sun, and Qiang Bao. "Numerical Study of Water Exchange in Environment Engineering in Pulandian Bay." Advanced Materials Research 908 (March 2014): 425–28. http://dx.doi.org/10.4028/www.scientific.net/amr.908.425.
Full textAbstract:
By the tracers of dissolved conservative substance, establishing the convection diffusion numerical model of water exchange in the bay. The water exchange simulation results derive the half-exchange period of each region.And based on the hydrological data,model results show the tidal current field and the half-exchange period,analyzing the water exchange properties and the convective transport of pollutants to the Pulandian Bay.The numerical simulation results provide the scientific basis and basic data for the sea area construction and environmental protection.
Dissertations / Theses on the topic "Conservative and non-conservative environmental tracers"
1
Ham, Brian. "Using Conservative and Biological Tracers to Better Understand the Transport of Agricultural Contaminants from Soil Water through the Epikarstic Zone." TopSCHOLAR®, 2009. http://digitalcommons.wku.edu/theses/133.
Full textAbstract:
Agriculture contamination is very common in karst systems due to the vulnerability of these aquifers. Animal waste is often spread across crop land to enrich the soil with nitrates and phosphates. Herbicides and pesticides are also applied to the crops. The transport of these pollutants through the soil and epikarst is a difficult process to monitor due to the complex, heterogeneous behavior of the groundwater as it makes its way down to the aquifer below.
An experimental site at Crumps Cave lended a unique opportunity to monitor the vadose zone at a waterfall in the cave below. A previous dye trace established the connection between an 11.15 m2 grass plot and this underground waterfall. The field design used here, utilizing a rainfall simulator, allowed control of the input of precipitation and tracers to understand more about the movement of stormwater infiltrating the soil and the differences in transport of solute particles and bacteria in the epikarstic zone. Two particle transport experiments were used to better understand these processes. The first trace involved injection of fluorescein dye and sodium chloride. The 2,650 liters of solution were injected over a period of 3.6 hours at a rate of 6.6 cm/hr. An electrical resistivity traverse, perpendicular to the hypothesized straight-line path of the established dye trace connection, showed a peak in lower resistance at the upper epikarst layers 4 hours and 15 minutes after the beginning of the injection. Dye concentrations reached a peak of 1,600 ppb 3 hours and 15 minutes after the beginning of the injection. The conductivity also peaked at this time with a value of 814 µS. This first trace showed that rapid transportation of solutes happened in localized conduits causing a peak of both solutes in the cave before the widespread mobilization of sodium chloride was seen in the epikarst by the resistivity images an hour later.
In the second trace, 2,605 liters of a sulphorhodamine dye solution was injected over 180 kg of dairy cattle manure spread on the 11.15 m2 plot of grass for a period of 3.6 hours at a rate of 6.6 cm/hr. Dye concentrations reached a peak of 27 ppm 4 hours and 15 minutes after the beginning of the injection. Fecal coliform reached its first peak of 2,755 MPN (most probable number of viable cells per 100 mL of water) 90 minutes prior to the dye peak and a second peak of 2,481 MPN occurred 15 minutes prior to the dye peak. These results showed that solutes travelling through the soil and epikarst follow similar paths while bacteria prefer conduits that offer more rapid transmission to the underground waterfall.
2
Smith, Simon Alastair. "Understanding the non-conservative behaviour of fluorescein." Pretoria : [s.n.], 2002. http://upetd.up.ac.za/thesis/available/etd-10272005-140436/.
Full text
3
Dixon-Jain, Prachi. "Groundwater-surface water interactions : implications for nutrient transport to tropical rivers." Phd thesis, 2008. http://hdl.handle.net/1885/9514.
Full textAbstract:
The interaction between groundwater and surface water systems is a key component of the hydrological cycle and an understanding of their connectivity is fundamental for sustainable water resource management. Water is a vehicle for mobilising dissolved constituents, including nutrients, between surface and subsurface waters and between terrestrial and marine systems.
Therefore, knowledge of surface-subsurface linkages is critical not only for water quantity allocation, but also for water quality and its implications for ecosystem health. In particular, ascertaining the significance of groundwater fluxes for river nitrogen budgets is an important motivation for characterising river-groundwater connectivity. This overarching theme is developed through the course of the thesis.
The marked seasonality of tropical river systems provides a unique opportunity to investigate groundwater contributions to surface waters, especially when there are minimal overland flows.
The Herbert River in northeast Queensland represents a useful case study in the Australian tropics for assessing the potential for transport of agricultural contaminants, such as dissolved forms of nitrogen, between surface and subsurface waters, and between terrestrial and marine systems, including the ecologically significant Great Barrier Reef World Heritage Area. Whilst the lower Herbert River catchment, dominated by sugarcane production, is the focus for this thesis, the research methodology and policy implications for nutrient monitoring and management are applicable to other tropical catchments.
An extensive water quality sampling program was instigated to collect river and groundwater samples during low flow conditions, for analysis of a range of conservative and nonconservative environmental tracers including major ions, stable isotopes of water, radon, and dissolved inorganic forms of nitrogen. Grab samples were collected during months representing the beginning and end of the dry season to compare connectivity relationships at contrasting stages of the stream hydrograph. Hydrochemical data at the end of the dry season is particularly useful for isolating the groundwater signal in the river and its tributaries. Existing physical and chemical datasets are also an important source of high temporal resolution information to supplement the more detailed water quality data collected specifically for this investigation.
An understanding of the dynamics of water movement between river and aquifer storages is critical for assessing the mobility of dissolved nitrogen between them. A combination of hydrogeological, hydrometric, hydrological and hydrochemical tools are applied to characterise the interaction between the alluvial aquifers and the lower Herbert River at a catchment scale.
Specifically, the potential for hydraulic connection and the direction of flux between the aquifer system and the river are evaluated through qualitative hydrometric approaches, including: depth relationships of the river channel with that of the underlying alluvial sediments; historical groundwater elevation-stream stage relationships; and groundwater flow patterns around the river. Hydrological techniques such as stream hydrograph and flow duration curve analysis are utilised to assess the temporal characteristics of flow in the river; the groundwater flux to the river is also quantified by hydrograph separation. Physical understanding of river-aquifer linkages is verified and enriched through analysis of surface water chemistry data, in conjunction with the conceptual hydrogeological model developed from physical and chemical assessment of the aquifers. The significance of groundwater as a vector for nitrogen is then evaluated in light of a conceptual process understanding of the river-aquifer system. This provides a platform for undertaking future catchment-scale nutrient budget studies based on detailed investigations of nitrogen sources and transformations.
The research approach used in this thesis highlights the value of combining analytical techniques, not provided by any one method, to inform and verify different aspects of a complex water resource problem involving both surface and groundwater systems. The application of multiple environmental tracers, at varied spatial and temporal resolution, is particularly instructive for distinguishing between the key processes that influence the chemistry of the river in space and time. Furthermore, the spectrum of tracer techniques provides both qualitative and quantitative information regarding the flux of groundwater along the length of the lower Herbert River. Whilst the absolute groundwater fluxes determined have a degree of uncertainty, mass balances of radon and selected solutes highlight the value of quantitative estimates in combination with qualitative trends to characterise river-aquifer relationships. The analyses demonstrate that discharge of groundwater from the alluvial aquifers is a dominant influence on both the flow and chemistry of the lower Herbert River in the dry season. In particular, groundwater is a key vector for the delivery of nitrate to the river during low flow conditions.
This provides a new perspective for monitoring and management of nutrients in tropical rivers where there is good connectivity with the underlying groundwater system. Key recommendations arising from this research include: (1) water quality sampling should be undertaken at recognised periods on the stream/groundwater hydrograph, with an understanding of temporal and spatial river-aquifer connectivity relationships; (2) surface and subsurface sources of water and dissolved nutrients must be considered, including identification of nutrient hotpots in both surface water and groundwater systems; (3) sampling locations should capture the longitudinal variation in river nutrient concentrations, not simply end-of-river monitoring; (4) appropriate water quality guideline values must be set to account for seasonal changes in both the sources and forms of nutrients transported to surface waters.
Book chapters on the topic "Conservative and non-conservative environmental tracers"
1
Kipfer, R., and F. Peeters. "Using Transient Conservative and Environmental Tracers to Study Water Exchange in Lake Issyk-Kul." In Lake Issyk-Kul: Its Natural Environment, 89–100. Dordrecht: Springer Netherlands, 2002. http://dx.doi.org/10.1007/978-94-010-0491-6_8.
Full text
2
Warrick, Arthur W. "Solute and Contaminant Transport." In Soil Water Dynamics. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195126051.003.0012.
Full textAbstract:
We now look at the transport of materials in soil systems. Not only do water and liquids move, but so also do a variety of chemical and biological constituents. In this chapter, the emphasis will be on flow processes involving water that is carrying different types of solute. The solutes of interest can be harmful or they can be beneficial. The same chemical species could be desirable when contained within one region and undesirable if it escapes to another—such as from the root zone to the ground water. Both conservative and reactive tracers will be discussed. A conservative tracer is assumed to move freely with the soil water and is non-reactive, non-volatile, and non-absorbing. Of course, this is only an ideal case, and all materials carried with water will react in some way with the solid phase. The degree of interaction depends on the solute, the soil, and the flow regime. However, if there is little interaction, the solute can often be treated as a conservative tracer. Examples are tritium and, to a lesser degree, bromide. Other materials are only slightly soluble, readily react with the solid phase, or perhaps can change into alternative phases that are clearly non-conservative. In some cases, whether a solute can logically be considered as a conservative or non-conservative tracer depends on the time scale and where the process is occurring—for example, perhaps the reaction rates are low, and for a short time scale the process is conservative; alternatively, perhaps the reaction rate is driven by whether oxygen is available or whether a specific microbe or catalyst is present at a particular time and place. Most of the discussion is directed toward “miscible displacement” processes. For a miscible displacement process, the invading fluid mixes freely with the fluid that is being driven out. An example is the displacement of water of a concentration differing from that of the antecedent water. Miscible displacement of a low molecular weight alcohol with water is another example. Many problems of environmental concern are included, such as leaching of nitrates from the soil surface to the groundwater.
3
Xu, Ying. "The Electronic-Mediated Public Sphere and Environmental Public Participation in China." In ICT Management in Non-Profit Organizations, 134–45. IGI Global, 2014. http://dx.doi.org/10.4018/978-1-4666-5974-2.ch008.
Full textAbstract:
This chapter offers a critical analysis of the new pattern of public participation in the electronic-mediated public sphere. By reviewing the development of Chinese environmental activities that led to an active, electronic-mediated public discussion concerning environmental protection, the findings reveal that new Information and Communications Technologies (ICTs) have made the public sphere more easily seen and heard by everyone, including governmental departments in the bureaucratic system. Thus, the electronic-mediated public sphere is providing a third power that could help Non-Profit Organizations' (NPOs) development in relatively conservative societies such as China. The implications of using ICTs in the management of NPOs are also discussed.
4
Nielsen, Philipp. "Turmoil, 1918–1924." In Between Heimat and Hatred, 115–68. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780190930660.003.0004.
Full textAbstract:
This chapter describes the ways in which right-wing Jews, whether they described themselves as “royalist,” “nationally minded” (nationalgesinnt), or “conservative,” attempted to make sense of the political and social changes around them following Germany’s defeat in the First World War and amid revolution at home. None of them were mere bystanders but active participants in their environment. The extent to which they could remain integrated into the Right in the years between 1918/1919 and 1924, on what terms, and in which parts of it, reflects the wider development of social and political circles they moved in, and thus the development of the wider Right, in the first five years of the Weimar Republic. It traces the rise of new concepts of belonging, namely the community of the trenches and the people’s community.
5
O’Dubhthaigh, Daire, Marlies Borchers, Yan Jin, and Paul Maropoulos. "Implementing Smart Manufacturing Technology into the Textile Industry." In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220562.
Full textAbstract:
The growing customer demand for small batch-size and customised products is putting pressure on manufacturers to adapt their current processes that were originally designed for large batch size orders. Smart manufacturing technology can be utilised to create new, effective, and sustainable processes. Many industries are still conservative when it comes to embracing smart manufacturing technologies including the textile industry. This paper demonstrates the implementation of smart technology to create a new “made to customisation” process in a textile factory. The case study involves upgrading a standard machine to a “smart” machine and utilising RFID technology to track and trace materials after they get prepared for a work order. The paper also presents a guide on how to effectively approach the implementation of smart technology in the manufacturing environment.
6
Nobbs-Thiessen, Ben. "Military Bases and Rubber Tires." In Landscape of Migration, 65–101. University of North Carolina Press, 2020. http://dx.doi.org/10.5149/northcarolina/9781469656106.003.0003.
Full textAbstract:
This chapter explores the transnational undercurrents of Bolivia’s national revolution. It weaves together the geopolitical and environmental forces that led the Okinawans and Mennonites to Santa Cruz. In postwar Okinawa, the U.S. military displaced farmers as it constructed bases on expropriated lands across the Ryukyuan archipelago. From political protests and blockades to performances of model agrarian citizenship, Okinawans contested removal and several thousand were eventually relocated to Bolivia. There Okinawans employed the same strategy of model agrarian citizenship they had used to contest U.S. removal on the Ryukyuan islands to successfully counter xenophobia in Santa Cruz. The second half of this chapter begins with the small-scale migration of Paraguayan Mennonites to Bolivia in the mid-1950s before turning to Mexico where a prolonged midcentury drought was devastating farming communities in Chihuahua. In the face of drought many Mexican Mennonites initially traveled north to work as laborers on Canadian farms. Returning to Mexico, these braceros brought modern goods and evangelical missionaries back to their traditional colonies. The result was a bitter conflict that centered on the use of rubber tires, rather than steel wheels, on Mennonite tractors and pushed forward an exodus of conservative Mennonites to Bolivia in 1968.
7
Zachar Podolinská, Tatiana. "Traces of the Mary in Post-Communist Europe." In Traces of the Virgin Mary in Post-Communist Europe, 16–55. Institute of Ethnology and Social Anthropology, Slovak Academy of Sciences, VEDA, Publishing House of the Slovak Academy of Sciences, 2020. http://dx.doi.org/10.31577/2019.9788022417822.16-55.
Full textAbstract:
The Virgin Mary as such cannot be examined scientifically. We can, however, examine her ‘apparitions’ in the world, as well as the innumerable variants of Marian devotion and cult. This volume focuses on her manifestations in the post-Communist region with some geographical spillovers. It is either because post-Communist transformation concerned not only the former socialist countries, but also had an impact on the entire European region and was part of the overall post-modern and post-Communist reconfiguration of the European area. Another factor is that Marian worship is not controlled by political borders of present-day nation states. It has a wider transnational potential and impact. Nevertheless, we focused our viewfinder primarily on the post-Communist region, as we believe that thanks to its geographical and symbolic location and economic position in Europe, as well as its historical roots and traditions and common Communist history and heritage, it not only shows different traits of modernity compared to ‘Western Europe’, but we also face specific features and forms of worshipping of the Virgin Mary. We therefore decided to present in this volume the traces of the Virgin Mary by means of more in-depth analyses from selected countries of the post-socialist region. By means of this publication, we can observe how the Virgin Mary is manifested in the faces of seers and pilgrims and how audio-visual means are becoming a direct part of Marian apparitions in Germany in the modern era (H. Knoblauch and S. Petschke); how she speaks through the mouth of a blind Roma woman and pacifies the ethnic and religious tensions between various groups in Romania (L. Peti); how she attributes meaning to meaningless places on the map by reallocating her presence through the geo- graphical and time distribution of Marian dedications in Slovakia (J. Majo); how, after the fall of Communism, she revitalises the old places of her cult with new power, bringing together traditional and non-traditional forms of worship in the secular Czech Lands (M. Holubová); how her messages are spread on the websites of new non-traditional Marian movements and how their apocalyptical warnings are being updated and localised into the specific national environment in Czechia (V. Tutr); how she addresses the readers of Marian literature differently on the shelves of book- stores in Slovakia and Austria (R. Kečka); but also how the Virgin Mary absorbs ultra-modern millennial and spiritualistic concepts of Mother Earth and Mother of the Universe, becoming the speak- er of the great unified Hungarian nation (J. Kis-Halas); how she is becoming the re-discovered herald of Serbian national identity (A. Pavićević); how she absorbs the local forms of faith and folk Christianity in modern era and is thus the manifestation of grass- root Christianity and local religious culture in Bulgaria (V. Baeva and A. Georgieva); and how the path from a private to an officially recognised apparition depends not only on the Virgin Mary and the seer, but also on the overall constellation of the audience and the ability to offer a religious ready-made event (T. Zachar Podolinská and L. Peti). This publication observes the current diversity of the forms of Marian devotion in post-Communist countries through different national and geographically defined contours and, in particular, the ability of the Virgin Mary to satisfy the hunger for modern spirituality and authentic religiousness, give voice to unofficial and popular religions, revitalise and redefine old places of cult and add new ones, appease war conflicts, speak out on behalf of nations and marginalised ethnic groups, and guard national and conservative values. The post-modern and post-Communist Mary thus restores ruptured traditions with love and enchants the violently atheised European region with new miracles and apparitions, regardless of whether top Church and state representatives like it or not.
8
"Trace elements fingerprinting using accelerators and ICP-MS: circulation of gold from the 6th century BC to the 12th century AD." In Cultural Heritage Conservation and Environmental Impact Assessment by Non-Destructive Testing and Micro-Analysis, 231–52. CRC Press, 2004. http://dx.doi.org/10.1201/9781482283983-25.
Full textConference papers on the topic "Conservative and non-conservative environmental tracers"
1
Hormozi, S., B. Firoozabadi, H. Ghasvari Jahromi, and S. M. H. Moosavi Hekmati. "3-D Simulation of Conservative and Non-Conservative Density Current." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-15785.
Full textAbstract:
Flows generated by density differences are called gravity or density currents which are generic features of many environmental flows. These currents are classified as the conservative and non-conservative flows whether the buoyancy flux is conserved or changed respectively. In this paper, a low Reynolds k-ε turbulence model is used to simulate three dimensional density and turbidity currents. Also, a series of experiments were conducted in a straight channel to study the characteristics of the non-conservative density current. In experiments, Kaolin was used as the suspended material. Comparisons are made between conservative and non-conservative's height, concentration and velocity profiles of the current and their variations along the transverse intersections. Outcomes indicate that the presence of the particles influences the flow structure sensibly. The results are compared with the experiments and showed a good agreement.
2
Rhodes, Abby G., Matthew D. Covington, and Joshua M. Blackstock. "UTILIZING CONSERVATIVE AND NON-CONSERVATIVE TRACERS TO ESTIMATE CONDUIT GEOMETRY: PRELIMINARY RESULTS FROM EXPERIMENTS AT SAVOY EXPERIMENTAL WATERSHED, NORTHWEST ARKANSAS (USA)." In GSA Annual Meeting in Phoenix, Arizona, USA - 2019. Geological Society of America, 2019. http://dx.doi.org/10.1130/abs/2019am-340801.
Full text
3
Karpanan, Kumarswamy, and William Thomas. "Influence of Lode Angle on the ASME Local Strain Failure Criterion." In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63067.
Full textAbstract:
Failure strain at any point on a structure is not a constant but is a function of several factors, such as stress state, strain rate, and temperature. Failure strain predicted from the uniaxial tensile testing cannot be applied to the bi-axial or tri-axial stress state. ASME Sec VIII-Div-2, and −3 codes give methods to predict the failure strain for multi-axial stress state by considering the triaxiality factor, which is defined as the ratio of mean stress to the equivalent stress. Failure strain predicted by the ASME method (based on the Rice-Tracey ductile failure model) is an exponential curve that relates the failure strain to the triaxiality factor. The ASME VIII-3 method also gives procedures to calculate failure strain for various material types: ferritic, stainless steel, nickel alloy, aluminum, etc. Experimental results of failure strain at various stress states show that the failure strain is not only a function of the triaxiality factor, but also a function of the Lode angle. The Lode angle takes on the value of 1, 0, and −1 for tension, pure shear, and compression stress state, respectively. Experimental data shows that the failure strain is a 3D surface which has an exponential relation with triaxiality and a parabolic relation with the Lode angle. To validate the ASME failure strain prediction, this paper compares experimental failure strain test data from literature with the ASME predictions. The ASME predictions are non-conservative especially for moderately ductile materials such as aluminum and high strength carbon steel. A reduction factor on failure strain for low ductile material is presented using the relation between the R (yield/ultimate) and the stress ratio (shear/tensile stress). The ASME method does not account for the environmental effects while calculating the failure strain. High pressure, high temperature (HPHT) subsea components designed using ASME VIII-3 code are subjected to various environments in subsea, such as seawater, seawater with cathodic protection (CP) and production fluid (crude oil). Experimental data shows that the Elongation (EL) and/or Reduction in Area (RA) from tensile testing decrease in these environments. Therefore, to account for any environment effect on the failure strain, reduced EL and RA can be used to predict the failure strain.
4
Aydin, Hakki, Nirup Nagabandi, Diyar Jamal, and Cenk Temizel. "A Comprehensive Review of Tracer Test Applications in Geothermal Reservoirs." In SPE Western Regional Meeting. SPE, 2022. http://dx.doi.org/10.2118/209325-ms.
Full textAbstract:
Abstract Tracer test is a strong tool that is used to understand the connectivity between injection and production wells in geothermal reservoirs. It is essential to design and implement a tracer test for particular reservoir properties. Inappropriate tracer tests, might cuase wrong reservoir characterization interpretations. This study incorporates in the design, the implementation, and the interpretation of tracer tests in geothermal reservoirs. This study is populated with numerous field applications to ensure better understanding of the subject. The study initially present the types of tracers used in geothermal reservoirs. The appropriate tracer type is selected based on various parameters such as reservoir conditions, economics, type of measurement devices available, minimum detection concentration, environmentally friendly, and stability at reservoir conditions. Once the type of tracer is selected, the amount of tracer to be injected and the tracer sampling frequency are determined based on the distance between wells, mean traveling time, and the desired peak concentration. The tracer is injected as slug/continuous type to the selected injection wells and sampling from production wells. The measured tracer concentrations are then modeled with analytical methods such as the multi-fractures, single fracture, dual-porosity, and homogenous models. Naphthalene sulfonates, is frequently used in high-temperature geothermal reservoirs because of is high resistance and half-life in harsh conditions. Salts such as sodium chloride and potassium chloride are also conservative in harsh conditions; however, a large amount of salt is required to be injected to create an additional concentration in the reservoir brine, which already includes a certain salt concentration. Fluorescein is mostly applicable in low enthalpy reservoirs because of its weakness at high temperatures. Analytical models are matched with field data by using the nonlinear least square method. The most representative reservoir model is determined by evaluating the sum of the squared differences between tracer concentrations of the model and field data. Geothermal reservoirs are generally best matched with multi-fractures and dual-porosity models because of the secondary permeability and porosity of tectonic activities and mineral dissolution mechanisms. This study, provides a detailed information about tracer test design, implementation, and interpretation. It serves as a guidance by including numerous field cases and the latest research about tracers in geothermal.
5
Moore, Karen A., Robert Carrington, and John Richardson. "Detection and Location of Damage on Pipelines." In 2004 International Pipeline Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ipc2004-0450.
Full textAbstract:
The U.S. Dept of Energy Idaho National Engineering and Environmental Laboratory (INEEL) has developed and successfully tested a real-time pipeline damage detection and location system. This system uses porous metal resistive traces applied to the pipe to detect and locate damage. The porous metal resistive traces are sprayed along the length of a pipeline. The unique nature and arrangement of the traces allows locating the damage in real time along miles of pipe. This system allows pipeline operators to detect damage when and where it is occurring, and the decision to shut down a transmission pipeline can be made with actual real-time data, instead of conservative estimates from visual inspection above the area.
6
Vanem, Erik. "On the Influence of Environmental Contour Method in Estimating Extreme Structural Response." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61047.
Full textAbstract:
Environmental contours are often applied in probabilistic structural reliability analysis in order to identify extreme environmental conditions that may give rise to extreme loads and responses. The perhaps most common way of establishing such environmental contours are based on the Rosenblatt transform and the IFORM approximation (Inverse First Order Reliability Method), but recently an alternative approach based on direct Monte Carlo simulations with importance sampling has been proposed. A recent comparison study revealed that there might be rather large differences in certain parts of the contours and for certain joint environmental models. In particular, the alternative contour method yields convex contours by design, whereas the traditional contours may be convex or non-convex. In this paper, comparison studies that include applications on a few structural examples are presented. Comparing the contours with known response surfaces, one may investigate how large the differences between the contour methods may be, and compare this to the correct extreme response estimated by simulation studies. These case studies clearly illustrate the influence of the environmental contour calculation method on the estimated extreme response. Whereas the different methods yield comparable results for some structural problems, they may give very different estimates of the extreme response for other. It is demonstrated that in certain cases, the estimates from some of the contour methods are highly conservative, whereas they in other cases might be very optimistic. The reason for these results are discussed and some requirements on the response functions for obtaining conservative estimates will be stated.
7
Sarala, Resmi, Mohammad Hajiarab, and Richard Bamford. "Equivalent Design Wave Approach for Calculating Site-Specific Environmental Loads on an FPSO." In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-49580.
Full textAbstract:
This paper demonstrates the method used by Lloyd’s Register (LR) to derive an equivalent design wave from a response based analysis (RBA) to represent extreme loads on a weather-vaning FPSO [1] and proceeds to compare the results with that of the industry practice of the response amplitude operator (RAO) based approach. The responses investigated include roll, pitch, vertical wave bending moments, vertical wave shear forces and vertical acceleration. The RBA is based on 3 hourly hindcast metocean data and uses the results of the heading analysis directly, considering the combined effect of wind, wind-sea, current and swell. An equivalent design wave is then derived based on the spectral characteristics of each response instead of the common practice for ship design [2] which uses only the characteristics of the RAOs. For each response the design wave for the RBA and RAO approaches is compared. Deriving equivalent design waves using only the RAO characteristics is found to give some non-conservative and unrealistic equivalent design waves in some cases.
8
Kuznetsov, Andrey, Andrey Kuznetsov, Yury Fedorov, Yury Fedorov, Paul Fattal, Paul Fattal, Frederic Ebner, and Frederic Ebner. "SELF-CLEANING CAPACITY OF SEACOASTS IN CASE OF OIL POLLUTION." In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b9441ab8c21.53053195.
Full textAbstract:
The sea coasts are especially exposed to the oil pollution harmful influence as they frequently suffer from oil spills relating to the tanker accidents, port and off-shore activities. The objective of the present research is to examine the rates of spilled fuel oil natural destruction on geographically different seacoasts and to evaluate their relationship with principal environmental factors such as climatic and hydrological conditions, coast exposure and geomorphology, sediment types, intensity of biogeochemical cycles. For this purpose, a number of contaminated sectors of the Atlantic coasts of France and Spain (areas of “Erika” and “Prestige” tanker accidents), the Strait of Kerch (“Volgoneft-139” tanker accident) and the Black Sea coast in Russia (area of Novorossiysk sea port) were studied. Long-term (from 6 to 15 years) field observations were carried out there. The oiled samples were analyzed with the use of thin layer and column chromatography, optical and gravimetric methods. The results show that in the course of time, the oil slicks demonstrate an exponential diminution in their size, number and in the ratio of labile hydrocarbons content to conservative asphaltic components content. The half-period of this diminution varies from less than 1 to 12 years, subject to the forms of fuel oil traces and geographical conditions. On the Strait of Kerch coast washed by shallow, slightly salted and highly bio-productive waters of the Sea of Azov the spilled fuel oil tends to disappear twice as rapidly as on French and Spanish coasts of the Atlantic Ocean. The joint examination of the observed rates of oil pollution natural destruction and the geographical conditions of studied sites shows that temperature and seawater salinity are the crucial environmental factors of self-cleaning process.
9
Kuznetsov, Andrey, Andrey Kuznetsov, Yury Fedorov, Yury Fedorov, Paul Fattal, Paul Fattal, Frederic Ebner, and Frederic Ebner. "SELF-CLEANING CAPACITY OF SEACOASTS IN CASE OF OIL POLLUTION." In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b43166a1b2f.
Full textAbstract:
The sea coasts are especially exposed to the oil pollution harmful influence as they frequently suffer from oil spills relating to the tanker accidents, port and off-shore activities. The objective of the present research is to examine the rates of spilled fuel oil natural destruction on geographically different seacoasts and to evaluate their relationship with principal environmental factors such as climatic and hydrological conditions, coast exposure and geomorphology, sediment types, intensity of biogeochemical cycles. For this purpose, a number of contaminated sectors of the Atlantic coasts of France and Spain (areas of “Erika” and “Prestige” tanker accidents), the Strait of Kerch (“Volgoneft-139” tanker accident) and the Black Sea coast in Russia (area of Novorossiysk sea port) were studied. Long-term (from 6 to 15 years) field observations were carried out there. The oiled samples were analyzed with the use of thin layer and column chromatography, optical and gravimetric methods. The results show that in the course of time, the oil slicks demonstrate an exponential diminution in their size, number and in the ratio of labile hydrocarbons content to conservative asphaltic components content. The half-period of this diminution varies from less than 1 to 12 years, subject to the forms of fuel oil traces and geographical conditions. On the Strait of Kerch coast washed by shallow, slightly salted and highly bio-productive waters of the Sea of Azov the spilled fuel oil tends to disappear twice as rapidly as on French and Spanish coasts of the Atlantic Ocean. The joint examination of the observed rates of oil pollution natural destruction and the geographical conditions of studied sites shows that temperature and seawater salinity are the crucial environmental factors of self-cleaning process.
10
Faidy, Claude. "Status of French Road Map to Improve Environmental Fatigue Rules." In ASME 2012 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/pvp2012-78805.
Full textAbstract:
During the past 30 years many fatigue tests and fatigue analysis improvements have been developed in France in order to improve Codified Fatigue Rules of RCC-M and ASME Codes [1, 2]. This paper will present the major technical improvements to obtain reasonable evaluation of potential fatigue damage through EDF road map. Recently new results [3] confirm possible un-conservative fatigue material data: - High cycle fatigue in air for stainless steel, - Environmental effects on fatigue S-N curve for all materials - Fatigue Crack Growth law under PWR environment for stainless steel. In front of these new results, EDF has developed a “Fatigue Road Map” to improve the different steps of Codified fatigue rules. A periodic up-dating of proposed rules in the different French Codes: RCC-M, RCC-MRx and RSE-M with research of harmonization with other Code rules developed in USA, Japan and Germany in particular, will be done on a yearly basis. During the past 15 years, many results have been obtained through fatigue tests of stainless steel materials: - mean and design fatigue curve in air, - environmental effects on fatigue curves, - plasticity effects, - bi-axial load effects, - mean stress effects, - stress indices, - transferability from small to large specimen, - weld versus base metal. In parallel, many new developments have been made in non-nuclear pressure equipment industry: like the reference stress of ASME Section VIII or the structural stress of EN 13445. These methods are mainly well adapted to fatigue pressure cycling. In front of that situation, the French nuclear code organization needs to propose reliable rules for new design and for operating plants. Different proposals are under discussion and the status of the EDF proposals are presented in the paper. The consequences could be important for the utilities because a large part of the in-service inspection program is connected to some fatigue usage factor level between 0.5 and 1.
Reports on the topic "Conservative and non-conservative environmental tracers"
1
Russo, David, and William A. Jury. Characterization of Preferential Flow in Spatially Variable Unsaturated Field Soils. United States Department of Agriculture, October 2001. http://dx.doi.org/10.32747/2001.7580681.bard.
Full textAbstract:
Preferential flow appears to be the rule rather than the exception in field soils and should be considered in the quantitative description of solute transport in the unsaturated zone of heterogeneous formations on the field scale. This study focused on both experimental monitoring and computer simulations to identify important features of preferential flow in the natural environment. The specific objectives of this research were: (1) To conduct dye tracing and multiple tracer experiments on undisturbed field plots to reveal information about the flow velocity, spatial prevalence, and time evolution of a preferential flow event; (2) To conduct numerical experiments to determine (i) whether preferential flow observations are consistent with the Richards flow equation; and (ii) whether volume averaging over a domain experiencing preferential flow is possible; (3) To develop a stochastic or a transfer function model that incorporates preferential flow. Regarding our field work, we succeeded to develop a new method for detecting flow patterns faithfully representing the movement of water flow paths in structured and non-structured soils. The method which is based on application of ammonium carbonate was tested in a laboratory study. Its use to detect preferential flow was also illustrated in a field experiment. It was shown that ammonium carbonate is a more conservative tracer of the water front than the popular Brilliant Blue. In our detailed field experiments we also succeeded to document the occurrence of preferential flow during soil water redistribution following the cessation of precipitation in several structureless field soils. Symptoms of the unstable flow observed included vertical fingers 20 - 60 cm wide, isolated patches, and highly concentrated areas of the tracers in the transmission zone. Soil moisture and tracer measurements revealed that the redistribution flow became fingered following a reversal of matric potential gradient within the wetted area. Regarding our simulation work, we succeeded to develop, implement and test a finite- difference, numerical scheme for solving the equations governing flow and transport in three-dimensional, heterogeneous, bimodal, flow domains with highly contrasting soil materials. Results of our simulations demonstrated that under steady-state flow conditions, the embedded clay lenses (with very low conductivity) in bimodal formations may induce preferential flow, and, consequently, may enhance considerably both the solute spreading and the skewing of the solute breakthrough curves. On the other hand, under transient flow conditions associated with substantial redistribution periods with diminishing water saturation, the effect of the embedded clay lenses on the flow and the transport might diminish substantially. Regarding our stochastic modeling effort, we succeeded to develop a theoretical framework for flow and transport in bimodal, heterogeneous, unsaturated formations, based on a stochastic continuum presentation of the flow and a general Lagrangian description of the transport. Results of our analysis show that, generally, a bimodal distribution of the formation properties, characterized by a relatively complex spatial correlation structure, contributes to the variability in water velocity and, consequently, may considerably enhance solute spreading. This applies especially in formations in which: (i) the correlation length scales and the variances of the soil properties associated with the embedded soil are much larger than those of the background soil; (ii) the contrast between mean properties of the two subdomains is large; (iii) mean water saturation is relatively small; and (iv) the volume fraction of the flow domain occupied by the embedded soil is relatively large.
2
Wackett, Lawrence, Raphi Mandelbaum, and Michael Sadowsky. Bacterial Mineralization of Atrazine as a Model for Herbicide Biodegradation: Molecular and Applied Aspects. United States Department of Agriculture, January 1999. http://dx.doi.org/10.32747/1999.7695835.bard.
Full textAbstract:
Atrazine is a broadly used herbicide in agriculture and it was used here as a model to study the biodegradation of herbicides. The bacterium Pseudomonas sp. ADP metabolizes atrazine to carbon dioxide and ammonia and chloride. The genes encoding atrazine catabolism to cyanuric acid were cloned and expressed in Escherichia coli. The genes were designated atzA, atzB and atzC. Each gene was sequenced. The enzyme activities were characterized. AtzA is atrazine chlorohydrolase which takes atrazine to hydroxyatrizine. AtzB is hydroxyatrazine N-ethylaminohydrolase which produces N-isopropylammelide and N-ethylamine. AtzC is N-isopropylammelide N-isopropylaminohydrolase which produces cyanuric acid and N-isopropylamine. Each product was isolated and characterized to confirm their identity by chromatography and mass spectrometry. Sequence analysis indicated that each of the hydrolytic enzymes AtzA, AtzB and AtzC share identity which the aminohydrolase protein superfamily. Atrazine chlorohydrolase was purified to homogeneity. It was shown to have a kcat of 11 s-1 and a KM of 150 uM. It was shown to require a metal ion, either Fe(II), Mn(II) or Co(II), for activity. The atzA, atzB and atzC genes were shown to reside on a broad-host range plasmid in Pseudomonas sp. ADP. Six other recently isolated atrazine-degrading bacteria obtained from Europe and the United States contained homologs to the atz genes identified in Pseudomonas sp. ADP. The identity of the sequences were very high, being greater than 98% in all pairwise comparisons. This indicates that many atrazine-degrading bacteria worldwide metabolize atrazine via a pathway that proceeds through hydroxyatrazine, a metabolite which is non-phytotoxic and non-toxic to mammals. Enzymes were immobilized and used for degradation of atrazine in aqueous phases. The in-depth understanding of the genomics and biochemistry of the atrazine mineralization pathway enabled us to study factors affecting the prevalence of atrazine degradation in various agricultural soils under conservative and new agricultural practices. Moreover, Pseudomonas sp. ADP and/or its enzymes were added to atrazine-contaminated soils, aquifers and industrial wastewater to increase the rate and extent of atrazine biodegradation above that of untreated environments. Our studies enhance the ability to control the fate of regularly introduced pesticides in agriculture, or to reduce the environmental impact of unintentional releases.