Changing Regulations of COD Pollution Load of Weihe River Watershed above TongGuan Section, China

NASA Astrophysics Data System (ADS)

Zhu, Lei; Liu, WanQing

2018-02-01

TongGuan Section of Weihe River Watershed is a provincial section between Shaanxi Province and Henan Province, China. Weihe River Watershed above TongGuan Section is taken as the research objective in this paper and COD is chosen as the water quality parameter. According to the discharge characteristics of point source pollutions and non-point source pollutions, a method—characteristic section load (CSLD) method is suggested and point and non-point source pollution loads of Weihe River Watershed above TongGuan Section are calculated in the rainy, normal and dry season in 2013. The results show that the monthly point source pollution loads of Weihe River Watershed above TongGuan Section discharge stably and the monthly non-point source pollution loads of Weihe River Watershed above TongGuan Section change greatly and the non-point source pollution load proportions of total pollution load of COD decrease in the rainy, wet and normal period in turn.

Factors Influencing Farmers’ Adoption of Best Management Practices: A Review and Synthesis

EPA Science Inventory

Best management practices (BMPs) for reducing agricultural non-point source pollution are widely available. However, agriculture remains a major global contributor to degradation of waters because farmers often do not adopt BMPs. To improve water quality, it is necessary to under...

A Targeted Search for Point Sources of EeV Photons with the Pierre Auger Observatory

NASA Astrophysics Data System (ADS)

Aab, A.; Abreu, P.; Aglietta, M.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Anastasi, G. A.; Anchordoqui, L.; Andrada, B.; Andringa, S.; Aramo, C.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Avila, G.; Badescu, A. M.; Balaceanu, A.; Barreira Luz, R. J.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Biteau, J.; Blaess, S. G.; Blanco, A.; Blazek, J.; Bleve, C.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Borodai, N.; Botti, A. M.; Brack, J.; Brancus, I.; Bretz, T.; Bridgeman, A.; Briechle, F. L.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, L.; Cancio, A.; Canfora, F.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Chavez, A. G.; Chinellato, J. A.; Chudoba, J.; Clay, R. W.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Cronin, J.; D'Amico, S.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Jong, S. J.; De Mauro, G.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; Debatin, J.; Deligny, O.; Di Giulio, C.; Di Matteo, A.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; D'Olivo, J. C.; Dorosti, Q.; dos Anjos, R. C.; Dova, M. T.; Dundovic, A.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Fick, B.; Figueira, J. M.; Filipčič, A.; Fratu, O.; Freire, M. M.; Fujii, T.; Fuster, A.; Gaior, R.; García, B.; Garcia-Pinto, D.; Gaté, F.; Gemmeke, H.; Gherghel-Lascu, A.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Głas, D.; Glaser, C.; Golup, G.; Gómez Berisso, M.; Gómez Vitale, P. F.; González, N.; Gorgi, A.; Gorham, P.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huege, T.; Hulsman, J.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Johnsen, J. A.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Katkov, I.; Keilhauer, B.; Kemp, E.; Kemp, J.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kuempel, D.; Kukec Mezek, G.; Kunka, N.; Kuotb Awad, A.; LaHurd, D.; Lauscher, M.; Legumina, R.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopes, L.; López, R.; López Casado, A.; Luce, Q.; Lucero, A.; Malacari, M.; Mallamaci, M.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Mariş, I. C.; Marsella, G.; Martello, D.; Martinez, H.; Martínez Bravo, O.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melo, D.; Menshikov, A.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Mockler, D.; Mollerach, S.; Montanet, F.; Morello, C.; Mostafá, M.; Müller, A. L.; Müller, G.; Muller, M. A.; Müller, S.; Mussa, R.; Naranjo, I.; Nellen, L.; Nguyen, P. H.; Niculescu-Oglinzanu, M.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, H.; Núñez, L. A.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Palatka, M.; Pallotta, J.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pedreira, F.; Pȩkala, J.; Pelayo, R.; Peña-Rodriguez, J.; Pereira, L. A. S.; Perlín, M.; Perrone, L.; Peters, C.; Petrera, S.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Ramos-Pollan, R.; Rautenberg, J.; Ravignani, D.; Revenu, B.; Ridky, J.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rogozin, D.; Roncoroni, M. J.; Roth, M.; Roulet, E.; Rovero, A. C.; Ruehl, P.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santos, E. M.; Santos, E.; Sarazin, F.; Sarmento, R.; Sarmiento, C. A.; Sato, R.; Schauer, M.; Scherini, V.; Schieler, H.; Schimp, M.; Schmidt, D.; Scholten, O.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sigl, G.; Silli, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sonntag, S.; Sorokin, J.; Squartini, R.; Stanca, D.; Stanič, S.; Stasielak, J.; Stassi, P.; Strafella, F.; Suarez, F.; Suarez Durán, M.; Sudholz, T.; Suomijärvi, T.; Supanitsky, A. D.; Swain, J.; Szadkowski, Z.; Taboada, A.; Taborda, O. A.; Tapia, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Tomankova, L.; Tomé, B.; Torralba Elipe, G.; Travnicek, P.; Trini, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Vergara Quispe, I. D.; Verzi, V.; Vicha, J.; Villaseñor, L.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weindl, A.; Wiencke, L.; Wilczyński, H.; Winchen, T.; Wirtz, M.; Wittkowski, D.; Wundheiler, B.; Yang, L.; Yelos, D.; Yushkov, A.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zimmermann, B.; Ziolkowski, M.; Zong, Z.; Zuccarello, F.

2017-03-01

Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p-values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. These limits significantly constrain predictions of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region.

A Search for Point Sources of EeV Photons

NASA Astrophysics Data System (ADS)

Aab, A.; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fuji, T.; Gaior, R.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Islo, K.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, A. J.; Matthews, J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Peķala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Peters, C.; Petrera, S.; Petrolini, A.; Petrov, Y.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schulz, A.; Schulz, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Thao, N. T.; Theodoro, V. M.; Tiffenberg, J.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Whelan, B. J.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Auger Collaboration102, The Pierre

2014-07-01

Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from -85° to +20°, in an energy range from 1017.3 eV to 1018.5 eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of -2, is 0.06 eV cm-2 s-1, and no celestial direction exceeds 0.25 eV cm-2 s-1. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galaxy.

ROLE OF LAND USE AND BMPS IN REDUCING THE EFFECT OF EXTREME MAGNITUDE EVENTS ON SEDIMENT AND POLLUTANT TRANSPORT IN THE SE US COASTAL PLAIN AND MISSISSIPPI ALLUVIAL VALLEY

EPA Science Inventory

Suspended sediment is a major non-point source pollutant of surface waters. Best management practices (BMPs) and current landuse decisions may not be sufficient to protect water quality in a changing climate, as a result of a loss of efficiency at reducing suspended sedimen...

The importance of source configuration in quantifying footprints of regional atmospheric sulphur deposition.

PubMed

Vieno, M; Dore, A J; Bealey, W J; Stevenson, D S; Sutton, M A

2010-01-15

An atmospheric transport-chemistry model is applied to investigate the effects of source configuration in simulating regional sulphur deposition footprints from elevated point sources. Dry and wet depositions of sulphur are calculated for each of the 69 largest point sources in the UK. Deposition contributions for each point source are calculated for 2003, as well as for a 2010 emissions scenario. The 2010 emissions scenario has been chosen to simulate the Gothenburg protocol emission scenario. Point source location is found to be a major driver of the dry/wet deposition ratio for each deposition footprint, with increased precipitation scavenging of SO(x) in hill areas resulting in a larger fraction of the emitted sulphur being deposited within the UK for sources located near these areas. This reduces exported transboundary pollution, but, associated with the occurrence of sensitive soils in hill areas, increases the domestic threat of soil acidification. The simulation of plume rise using individual stack parameters for each point source demonstrates a high sensitivity of SO(2) surface concentration to effective source height. This emphasises the importance of using site-specific information for each major stack, which is rarely included in regional atmospheric pollution models, due to the difficulty in obtaining the required input data. The simulations quantify how the fraction of emitted SO(x) exported from the UK increases with source magnitude, effective source height and easterly location. The modelled reduction in SO(x) emissions, between 2003 and 2010 resulted in a smaller fraction being exported, with the result that the reductions in SO(x) deposition to the UK are less than proportionate to the emission reduction. This non-linearity is associated with a relatively larger fraction of the SO(2) being converted to sulphate aerosol for the 2010 scenario, in the presence of ammonia. The effect results in less-than-proportional UK benefits of reducing in SO(2) emissions, together with greater-than-proportional benefits in reducing export of UK SO(2) emissions. Copyright 2009 Elsevier B.V. All rights reserved.

Reducing Phosphorus Runoff from Biosolids with Water Treatment Residuals

USDA-ARS?s Scientific Manuscript database

A large fraction of the biosolids produced in the U.S. are placed in landfills or incinerated to avoid potential water quality problems associated with non-point source phosphorus (P) runoff. The objective of this study was to determine the effect of various chemical amendments on P runoff from bi...

Utilizing water treatment residuals to reduce phosphorus runoff from biosolids

USDA-ARS?s Scientific Manuscript database

Approximately 40% of biosolids (sewage sludge) produced in the U.S. are incinerated or landfilled rather than land applied due to concern over non-point source phosphorus (P) runoff. The objective of this study was to determine the impact of chemical amendments on water-extractable P (WEP) in appli...

The Potential Importance of Conservation, Restoration, and Altered Management Practices for Water Quality in the Wabash River Watershed

EPA Science Inventory

Non-point source (NPS) pollution is one of the leading causes of water quality impairment within the United States. Conservation, restoration and altered management (CRAM) practices may effectively reduce NPS pollutants discharge into receiving water bodies and enhance local and ...

Management practices used in agricultural drainage ditches to reduce Gulf of Mexico hypoxia

USDA-ARS?s Scientific Manuscript database

Agricultural non-point sources of nutrients and sediments have caused eutrophication and other water quality issues in aquatic and marine ecosystems, such as the annual occurrence of hypoxia in the Gulf of Mexico. Management practices have been implemented adjacent to and in agricultural drainage di...

Spatial optimization of watershed management practices for nitrogen load reduction using a modeling-optimization framework

EPA Science Inventory

Best management practices (BMPs) are perceived as being effective in reducing nutrient loads transported from non-point sources (NPS) to receiving water bodies. The objective of this study was to develop a modeling-optimization framework that can be used by watershed management p...

A Targeted Search for Point Sources of EeV Photons with the Pierre Auger Observatory

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

Aab, A.; Abreu, P.; Aglietta, M.

Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p-values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. Lastly, these limits significantly constrain predictionsmore » of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region.« less

A Targeted Search for Point Sources of EeV Photons with the Pierre Auger Observatory

DOE PAGES

Aab, A.; Abreu, P.; Aglietta, M.; ...

2017-03-09

Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p-values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. Lastly, these limits significantly constrain predictionsmore » of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region.« less

A Targeted Search for Point Sources of EeV Photons with the Pierre Auger Observatory

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

Aab, A.; Abreu, P.; Aglietta, M.

Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p -values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. These limits significantly constrain predictionsmore » of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region.« less

[Urban non-point source pollution control by runoff retention and filtration pilot system].

PubMed

Bai, Yao; Zuo, Jian-E; Gan, Li-Li; Low, Thong Soon; Miao, Heng-Feng; Ruan, Wen-Quan; Huang, Xia

2011-09-01

A runoff retention and filtration pilot system was designed and the long-term purification effect of the runoff was monitored. Runoff pollution characters in 2 typical events and treatment effect of the pilot system were analyzed. The results showed that the runoff was severely polluted. Event mean concentrations (EMCs) of SS, COD, TN and TP in the runoff were 361, 135, 7.88 and 0.62 mg/L respectively. The runoff formed by long rain presented an obvious first flush effect. The first 25% flow contributed more than 50% of the total pollutants loading of SS, TP, DTP and PO4(3-). The pilot system could reduce 100% of the non-point source pollution if the volume of the runoff was less than the retention tank. Otherwise the overflow will be purification by the filtration pilot system and the removal rates of SS, COD, TN, TP, DTP and PO4(3-) reached 97.4% , 61.8%, 22.6%, 85.1%, 72.1%, and 85.2% respectively. The system was stable and the removal rate of SS, COD, TN, and TP were 98.6%, 65.4%, 55.1% and 92.6%. The whole system could effectively remove the non-point source pollution caused by runoff.

In-time source tracking of watershed loads of Taihu Lake Basin, China based on spatial relationship modeling.

PubMed

Wang, Ce; Bi, Jun; Zhang, Xu-Xiang; Fang, Qiang; Qi, Yi

2018-05-25

Influent river carrying cumulative watershed load plays a significant role in promoting nuisance algal bloom in river-fed lake. It is most relevant to discern in-stream water quality exceedance and evaluate the spatial relationship between risk location and potential pollution sources. However, no comprehensive studies of source tracking in watershed based on management grid have been conducted for refined water quality management, particularly for plain terrain with complex river network. In this study, field investigations were implemented during 2014 in Taige Canal watershed of Taihu Lake Basin. A Geographical Information System (GIS)-based spatial relationship model was established to characterize the spatial relationships of "point (point-source location and monitoring site)-line (river segment)-plane (catchment)." As a practical exemplification, in-time source tracking was triggered on April 15, 2015 at Huangnianqiao station, where TN and TP concentration violated the water quality standard (TN 4.0 mg/L, TP 0.15 mg/L). Of the target grid cells, 53 and 46 were identified as crucial areas having high pollution intensity for TN and TP pollution, respectively. The estimated non-point source load in each grid cell could be apportioned into different source types based on spatial pollution-related entity objects. We found that the non-point source load derived from rural sewage and livestock and poultry breeding accounted for more than 80% of total TN or TP load than another source type of crop farming. The approach in this study would be of great benefit to local authorities for identifying the serious polluted regions and efficiently making environmental policies to reduce watershed load.

DISCRIMINATION OF NATURAL AND NON-POINT SOURCE EFFECTS FROM ANTHROGENIC EFFECTS AS REFLECTED IN BENTHIC STATE IN THREE ESTUARIES IN NEW ENGLAND

EPA Science Inventory

In order to protect estuarine resources, managers must be able to discern the effects of natural conditions and non-point source effects, and separate them from multiple anthropogenic point source effects. Our approach was to evaluate benthic community assemblages, riverine nitro...

Presence of Pathogens and Indicator Microbes at a Non-Point Source Subtropical Recreational Marine Beach ▿ †

PubMed Central

Abdelzaher, Amir M.; Wright, Mary E.; Ortega, Cristina; Solo-Gabriele, Helena M.; Miller, Gary; Elmir, Samir; Newman, Xihui; Shih, Peter; Bonilla, J. Alfredo; Bonilla, Tonya D.; Palmer, Carol J.; Scott, Troy; Lukasik, Jerzy; Harwood, Valerie J.; McQuaig, Shannon; Sinigalliano, Chris; Gidley, Maribeth; Plano, Lisa R. W.; Zhu, Xiaofang; Wang, John D.; Fleming, Lora E.

2010-01-01

Swimming in ocean water, including ocean water at beaches not impacted by known point sources of pollution, is an increasing health concern. This study was an initial evaluation of the presence of indicator microbes and pathogens and the association among the indicator microbes, pathogens, and environmental conditions at a subtropical, recreational marine beach in south Florida impacted by non-point sources of pollution. Twelve water and eight sand samples were collected during four sampling events at high or low tide under elevated or reduced solar insolation conditions. The analyses performed included analyses of fecal indicator bacteria (FIB) (fecal coliforms, Escherichia coli, enterococci, and Clostridium perfringens), human-associated microbial source tracking (MST) markers (human polyomaviruses [HPyVs] and Enterococcus faecium esp gene), and pathogens (Vibrio vulnificus, Staphylococcus aureus, enterovirus, norovirus, hepatitis A virus, Cryptosporidium spp., and Giardia spp.). The enterococcus concentrations in water and sand determined by quantitative PCR were greater than the concentrations determined by membrane filtration measurement. The FIB concentrations in water were below the recreational water quality standards for three of the four sampling events, when pathogens and MST markers were also generally undetectable. The FIB levels exceeded regulatory guidelines during one event, and this was accompanied by detection of HPyVs and pathogens, including detection of the autochthonous bacterium V. vulnificus in sand and water, detection of the allochthonous protozoans Giardia spp. in water, and detection of Cryptosporidium spp. in sand samples. The elevated microbial levels were detected at high tide and under low-solar-insolation conditions. Additional sampling should be conducted to further explore the relationships between tidal and solar insolation conditions and between indicator microbes and pathogens in subtropical recreational marine waters impacted by non-point source pollution. PMID:19966020

[Spatial heterogeneity and classified control of agricultural non-point source pollution in Huaihe River Basin].

PubMed

Zhou, Liang; Xu, Jian-Gang; Sun, Dong-Qi; Ni, Tian-Hua

2013-02-01

Agricultural non-point source pollution is of importance in river deterioration. Thus identifying and concentrated controlling the key source-areas are the most effective approaches for non-point source pollution control. This study adopts inventory method to analysis four kinds of pollution sources and their emissions intensity of the chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in 173 counties (cities, districts) in Huaihe River Basin. The four pollution sources include livestock breeding, rural life, farmland cultivation, aquacultures. The paper mainly addresses identification of non-point polluted sensitivity areas, key pollution sources and its spatial distribution characteristics through cluster, sensitivity evaluation and spatial analysis. A geographic information system (GIS) and SPSS were used to carry out this study. The results show that: the COD, TN and TP emissions of agricultural non-point sources were 206.74 x 10(4) t, 66.49 x 10(4) t, 8.74 x 10(4) t separately in Huaihe River Basin in 2009; the emission intensity were 7.69, 2.47, 0.32 t.hm-2; the proportions of COD, TN, TP emissions were 73%, 24%, 3%. The paper achieves that: the major pollution source of COD, TN and TP was livestock breeding and rural life; the sensitivity areas and priority pollution control areas among the river basin of non-point source pollution are some sub-basins of the upper branches in Huaihe River, such as Shahe River, Yinghe River, Beiru River, Jialu River and Qingyi River; livestock breeding is the key pollution source in the priority pollution control areas. Finally, the paper concludes that pollution type of rural life has the highest pollution contribution rate, while comprehensive pollution is one type which is hard to control.

Evaluation of Water Quality Trends in Goodwater Creek Experimental Watershed, Missouri: Implications for Monitoring Strategies and Objective Setting

USDA-ARS?s Scientific Manuscript database

Continued public support for U.S. tax-payer funded programs aimed at reducing agricultural non-point source pollutants depends on clear demonstrations of water quality improvements. Effectiveness of structural BMPs, as well as watershed monitoring networks is an important information need to make f...

Potential water yield reduction due to forestation across China

Treesearch

Ge Sun; Guoyi Zhou; Zhiqiang Zhang; Xiaohua Wei; Steven G. McNulty; James M. Vose

2006-01-01

It is widely recognized that vegetation restoration will have positive effects on watershed health by reducing soil erosion and non-point source pollution, enhancing terrestrial and aquatic habitat, and increasing ecosystem carbon sequestration. However, the hydrologic consequences of forestation on degraded lands are not well studied in the forest hydrology community...

A method to analyze "source-sink" structure of non-point source pollution based on remote sensing technology.

PubMed

Jiang, Mengzhen; Chen, Haiying; Chen, Qinghui

2013-11-01

With the purpose of providing scientific basis for environmental planning about non-point source pollution prevention and control, and improving the pollution regulating efficiency, this paper established the Grid Landscape Contrast Index based on Location-weighted Landscape Contrast Index according to the "source-sink" theory. The spatial distribution of non-point source pollution caused by Jiulongjiang Estuary could be worked out by utilizing high resolution remote sensing images. The results showed that, the area of "source" of nitrogen and phosphorus in Jiulongjiang Estuary was 534.42 km(2) in 2008, and the "sink" was 172.06 km(2). The "source" of non-point source pollution was distributed mainly over Xiamen island, most of Haicang, east of Jiaomei and river bank of Gangwei and Shima; and the "sink" was distributed over southwest of Xiamen island and west of Shima. Generally speaking, the intensity of "source" gets weaker along with the distance from the seas boundary increase, while "sink" gets stronger. Copyright © 2013 Elsevier Ltd. All rights reserved.

Area Source Emission Measurements Using EPA OTM 10

EPA Science Inventory

Measurement of air pollutant emissions from area and non-point sources is an emerging environmental concern. Due to the spatial extent and non-homogenous nature of these sources, assessment of fugitive emissions using point sampling techniques can be difficult. To help address th...

32 CFR 806.20 - Records of non-U.S. government source.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.20 Records of non-U.S. government source. (a...-mail address of: their own FOIA office point of contact; the Air Force record OPR point of contact, the... 32 National Defense 6 2010-07-01 2010-07-01 false Records of non-U.S. government source. 806.20...

32 CFR 806.20 - Records of non-U.S. government source.

Code of Federal Regulations, 2011 CFR

2011-07-01

... ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.20 Records of non-U.S. government source. (a...-mail address of: their own FOIA office point of contact; the Air Force record OPR point of contact, the... 32 National Defense 6 2011-07-01 2011-07-01 false Records of non-U.S. government source. 806.20...

32 CFR 806.20 - Records of non-U.S. government source.

Code of Federal Regulations, 2013 CFR

2013-07-01

... ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.20 Records of non-U.S. government source. (a...-mail address of: their own FOIA office point of contact; the Air Force record OPR point of contact, the... 32 National Defense 6 2013-07-01 2013-07-01 false Records of non-U.S. government source. 806.20...

Phosphorus leaching from soil cores from a twenty-year study evaluating alum treatment of poultry litter

USDA-ARS?s Scientific Manuscript database

Adding alum (aluminum sulfate) to poultry litter is a best management practice (BMP) used to stabilize phosphorus (P) in less soluble forms, reducing non-point source P runoff. However, little research has been conducted on the effects of alum-treated poultry litter on P leaching. The objective of...

Star Tracker Based ATP System Conceptual Design and Pointing Accuracy Estimation

NASA Technical Reports Server (NTRS)

Orfiz, Gerardo G.; Lee, Shinhak

2006-01-01

A star tracker based beaconless (a.k.a. non-cooperative beacon) acquisition, tracking and pointing concept for precisely pointing an optical communication beam is presented as an innovative approach to extend the range of high bandwidth (> 100 Mbps) deep space optical communication links throughout the solar system and to remove the need for a ground based high power laser as a beacon source. The basic approach for executing the ATP functions involves the use of stars as the reference sources from which the attitude knowledge is obtained and combined with high bandwidth gyroscopes for propagating the pointing knowledge to the beam pointing mechanism. Details of the conceptual design are presented including selection of an orthogonal telescope configuration and the introduction of an optical metering scheme to reduce misalignment error. Also, estimates are presented that demonstrate that aiming of the communications beam to the Earth based receive terminal can be achieved with a total system pointing accuracy of better than 850 nanoradians (3 sigma) from anywhere in the solar system.

A paddy eco-ditch and wetland system to reduce non-point source pollution from rice-based production system while maintaining water use efficiency.

PubMed

Xiong, Yujiang; Peng, Shizhang; Luo, Yufeng; Xu, Junzeng; Yang, Shihong

2015-03-01

Non-point source (NPS) pollution from agricultural drainage has aroused widespread concerns throughout the world due to its contribution to eutrophication of water bodies. To remove nitrogen (N) and phosphorus (P) from agricultural drainage in situ, a Paddy Eco-ditch and Wetland System (PEDWS) was designed and built based on the characteristics of the irrigated rice district. A 2-year (2012-2013) field experiment was conducted to evaluate the performance of this system in Gaoyou Irrigation District in Eastern China. The results showed that the reduction in water input in paddy field of the PEDWS enabled the maintenance of high rice yield; it significantly increased irrigation water productivity (WPI), gross water productivity (WPG), and evapotranspiration water productivity (WPET) by 109.2, 67.1, and 17.6%, respectively. The PEDWS dramatically decreased N and P losses from paddy field. Compared with conventional irrigation and drainage system (CIDS), the amount of drainage water from PEDWS was significantly reduced by 56.2%, the total nitrogen (TN) concentration in drainage was reduced by 42.6%, and thus the TN and total phosphorus (TP) losses were reduced by 87.8 and 70.4%. PEDWS is technologically feasible and applicable to treat nutrient losses from paddy fields in situ and can be used in similar areas.

Ambiguity of non-systematic chemical identifiers within and between small-molecule databases.

PubMed

Akhondi, Saber A; Muresan, Sorel; Williams, Antony J; Kors, Jan A

2015-01-01

A wide range of chemical compound databases are currently available for pharmaceutical research. To retrieve compound information, including structures, researchers can query these chemical databases using non-systematic identifiers. These are source-dependent identifiers (e.g., brand names, generic names), which are usually assigned to the compound at the point of registration. The correctness of non-systematic identifiers (i.e., whether an identifier matches the associated structure) can only be assessed manually, which is cumbersome, but it is possible to automatically check their ambiguity (i.e., whether an identifier matches more than one structure). In this study we have quantified the ambiguity of non-systematic identifiers within and between eight widely used chemical databases. We also studied the effect of chemical structure standardization on reducing the ambiguity of non-systematic identifiers. The ambiguity of non-systematic identifiers within databases varied from 0.1 to 15.2 % (median 2.5 %). Standardization reduced the ambiguity only to a small extent for most databases. A wide range of ambiguity existed for non-systematic identifiers that are shared between databases (17.7-60.2 %, median of 40.3 %). Removing stereochemistry information provided the largest reduction in ambiguity across databases (median reduction 13.7 percentage points). Ambiguity of non-systematic identifiers within chemical databases is generally low, but ambiguity of non-systematic identifiers that are shared between databases, is high. Chemical structure standardization reduces the ambiguity to a limited extent. Our findings can help to improve database integration, curation, and maintenance.

[Empirical study on non-point sources pollution based on landscape pattern & ecological processes theory: a case of soil water loss on the Loess Plateau in China].

PubMed

Suo, An-ning; Wang, Tian-ming; Wang, Hui; Yu, Bo; Ge, Jian-ping

2006-12-01

Non-point sources pollution is one of main pollution modes which pollutes the earth surface environment. Aimed at soil water loss (a typical non-point sources pollution problem) on the Losses Plateau in China, the paper applied a landscape patternevaluation method to twelve watersheds of Jinghe River Basin on the Loess Plateau by means of location-weighted landscape contrast index(LCI) and landscape slope index(LSI). The result showed that LSI of farm land, low density grass land, forest land and LCI responded significantly to soil erosion modulus and responded to depth of runoff, while the relationship between these landscape index and runoff variation index and erosion variation index were not statistically significant. This tell us LSI and LWLCI are good indicators of soil water loss and thus have big potential in non-point source pollution risk evaluation.

Metabolomics for in situ environmental monitoring of surface waters impacted by contaminants from both point and non-point sources

EPA Science Inventory

We investigated the efficacy of metabolomics for field-monitoring of fish exposed to waste water treatment plant (WWTP) effluents and non-point sources of chemical contamination. Lab-reared male fathead minnows (Pimephales promelas, FHM) were held in mobile monitoring units and e...

ArcAPEX modeling of optimum widths and placement of grass and agroforestry buffers to reduce runoff and sediment transport in claypan watersheds

USDA-ARS?s Scientific Manuscript database

Existence of a claypan layer in soils at depths ranging from 4 to 37 cm restricts vertical water movement and has contributed significantly to high rates of runoff, sediment transport, and other non-point source loadings from croplands in watersheds. The deposition of these pollutants in rivers, st...

Watershed scale assessment of the impact of forested riparian zones on stream water quality

Treesearch

J. A. Webber; K. W. J. Williard; M. R. Whiles; M. L. Stone; J. J. Zaczek; D. K. Davie

2003-01-01

Federal and state land management agencies have been promoting forest and grass riparian zones to combat non-point source nutrient and sediment pollution of our nations' waters. The majority of research examining the effectiveness of riparian buffers at reducing nutrient and sediment inputs to streams has been conducted at the field scale. This study took a...

An unexpected truth: increasing nitrate loading can decrease nitrate export from watersheds

NASA Astrophysics Data System (ADS)

Askarizadeh Bardsiri, A.; Grant, S. B.; Rippy, M.

2015-12-01

The discharge of anthropogenic nitrate (e.g., from partially treated sewage, return flows from agricultural irrigation, and runoff from animal feeding operations) to streams can negatively impact both human and ecosystem health. Managing these many point and non-point sources to achieve some specific end-point—for example, reducing the annual mass of nitrate exported from a watershed—can be a challenge, particularly in rapidly growing urban areas. Adding to this complexity is the fact that streams are not inert: they too can add or remove nitrate through assimilation (e.g., by stream-associated plants and animals) and microbially-mediated biogeochemical reactions that occur in streambed sediments (e.g., respiration, ammonification, nitrification, denitrification). By coupling a previously published correlation for in-stream processing of nitrate [Mulholland et al., Nature, 2008, 452, 202-205] with a stream network model of the Jacksons Creek watershed (Victoria, Australia) I demonstrate that managing anthropogenic sources of stream nitrate without consideration of in-stream processing can result in a number of non-intuitive "surprises"; for example, wastewater effluent discharges that increase nitrate loading but decrease in-stream nitrate concentrations can reduce the mass of nitrate exported from a watershed.

Occurrence of Surface Water Contaminations: An Overview

NASA Astrophysics Data System (ADS)

Shahabudin, M. M.; Musa, S.

2018-04-01

Water is a part of our life and needed by all organisms. As time goes by, the needs by human increased transforming water quality into bad conditions. Surface water contaminated in various ways which is pointed sources and non-pointed sources. Pointed sources means the source are distinguished from the source such from drains or factory but the non-pointed always occurred in mixed of elements of pollutants. This paper is reviewing the occurrence of the contaminations with effects that occurred around us. Pollutant factors from natural or anthropology factors such nutrients, pathogens, and chemical elements contributed to contaminations. Most of the effects from contaminated surface water contributed to the public health effects also to the environments.

Urban Runoff Impact on the qPCR Signal of Enterococci and Other Alternative Fecal Indicators in a Tropical Beach

EPA Science Inventory

In order to effectively control inputs of contamination to coastal recreational waters, an improved understanding of the impact of both point and non-point sources of urban runoff is needed. In this study, we focused on the effect of non-point source urban runoff on the enterococ...

Improved source inversion from joint measurements of translational and rotational ground motions

NASA Astrophysics Data System (ADS)

Donner, S.; Bernauer, M.; Reinwald, M.; Hadziioannou, C.; Igel, H.

2017-12-01

Waveform inversion for seismic point (moment tensor) and kinematic sources is a standard procedure. However, especially in the local and regional distances a lack of appropriate velocity models, the sparsity of station networks, or a low signal-to-noise ratio combined with more complex waveforms hamper the successful retrieval of reliable source solutions. We assess the potential of rotational ground motion recordings to increase the resolution power and reduce non-uniquenesses for point and kinematic source solutions. Based on synthetic waveform data, we perform a Bayesian (i.e. probabilistic) inversion. Thus, we avoid the subjective selection of the most reliable solution according the lowest misfit or other constructed criterion. In addition, we obtain unbiased measures of resolution and possible trade-offs. Testing different earthquake mechanisms and scenarios, we can show that the resolution of the source solutions can be improved significantly. Especially depth dependent components show significant improvement. Next to synthetic data of station networks, we also tested sparse-network and single station cases.

Measuring Seebeck Coefficient

NASA Technical Reports Server (NTRS)

Snyder, G. Jeffrey (Inventor)

2015-01-01

A high temperature Seebeck coefficient measurement apparatus and method with various features to minimize typical sources of errors is described. Common sources of temperature and voltage measurement errors which may impact accurate measurement are identified and reduced. Applying the identified principles, a high temperature Seebeck measurement apparatus and method employing a uniaxial, four-point geometry is described to operate from room temperature up to 1300K. These techniques for non-destructive Seebeck coefficient measurements are simple to operate, and are suitable for bulk samples with a broad range of physical types and shapes.

Better Assessment Science Integrating Point and Non-point Sources (BASINS)

EPA Pesticide Factsheets

Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is a multipurpose environmental analysis system designed to help regional, state, and local agencies perform watershed- and water quality-based studies.

40 CFR 52.2350 - Emission inventories.

Code of Federal Regulations, 2010 CFR

2010-07-01

...). This inventory addresses emissions from point, area, non-road, on-road mobile, and biogenic sources.... The ozone maintenance plan for Salt Lake and Davis Counties that the Governor submitted on February 19... carbon monoxide emissions from stationary point, area, non-road, and on-road mobile sources. (c) On June...

HYDROLOGY AND SEDIMENT MODELING USING THE BASINS NON-POINT SOURCE MODEL

EPA Science Inventory

The Non-Point Source Model (Hydrologic Simulation Program-Fortran, or HSPF) within the EPA Office of Water's BASINS watershed modeling system was used to simulate streamflow and total suspended solids within Contentnea Creek, North Carolina, which is a tributary of the Neuse Rive...

Agricultural non-point source pollution management in a reservoir watershed based on ecological network analysis of soil nitrogen cycling.

PubMed

Xu, Wen; Cai, Yanpeng; Rong, Qiangqiang; Yang, Zhifeng; Li, Chunhui; Wang, Xuan

2018-03-01

The Miyun Reservoir plays a pivotal role in providing drinking water for the city of Beijing. In this research, ecological network analysis and scenario analysis were integrated to explore soil nitrogen cycling of chestnut and Chinese pine forests in the upper basin of the Miyun Reservoir, as well as to seek favorable fertilization modes to reduce agricultural non-point source pollution. Ecological network analysis results showed that (1) the turnover time was 0.04 to 0.37 year in the NH 4 + compartment and were 15.78 to 138.36 years in the organic N compartment; (2) the Finn cycling index and the ratio of indirect to direct flow were 0.73 and 11.92 for the chestnut forest model, respectively. Those of the Chinese pine forest model were 0.88 and 29.23, respectively; and (3) in the chestnut forest model, NO 3 - accounted for 96% of the total soil nitrogen loss, followed by plant N (2%), NH 4 + (1%), and organic N (1%). In the Chinese pine forest, NH 4 + accounted for 56% of the total soil nitrogen loss, followed by organic N (34%) and NO 3 - (10%). Fertilization mode was identified as the main factor affecting soil N export. To minimize NH 4 + and NO 3 - outputs while maintaining the current plant yield (i.e., 7.85e0 kg N/year), a fertilization mode of 162.50 kg N/year offered by manure should be adopted. Whereas, to achieve a maximum plant yield (i.e., 3.35e1 kg N/year) while reducing NH 4 + and NO 3 - outputs, a fertilization mode of 325.00 kg N/year offered by manure should be utilized. This research is of wide suitability to support agricultural non-point source pollution management at the watershed scale.

[Effect of terracing project on temporal-spatial variation of non-point source pollution load in Hujiashan watershed, China].

PubMed

Han, Qiang; Yu, Xing Xiu; Wang, Wei; Xu, Miao Miao; Ren, Rui; Zhang, Jia Peng

2017-04-18

Taking Hujiashan small watershed as the study area, based on the classified result of Landsat TM/ETM images of 2005, 2010 and 2015, combined with long-term field observation data, and used the export coefficient model, our study explored the effect of small watershed management project on temporal and spatial variation of total nitrogen (TN) load of non-point source pollution under the support of GIS technology. The results indicated that, due to the implementation of slope modification project, the area of cultivated land was significantly increased, while forest and bareland were decreased. The load of non-point source TN increased from 63208 kg in 2005 to 72778 kg in 2010, but reduced to 46876 kg in 2015. The contribution rate from residential areas was higher, the average contribution rate of the three periods was 53.5%, but it showed a decreasing trend year by year. The contribution rate of land use types was 45%, which showed an increasing trend year by year. The contribution rate of livestock was always low. From the spatial distribution, TN loading intensity was changed obviously after the terracing project. High load intensity zone was mainly concentrated on the slope of 5°-15° before terracing project. Nevertheless, high load intensity zone was concentrated on the slope of 15°-35° after terracing project, and 5°-8° had become a low load strength area. The TN load intensity changed little with time on the slope of 0°-8°, and it increased first and then decreased on the slope above 8°. With the treatment of sewage, garbage and livestock manure in rural areas, the output of nitrogen in the living and livestock breeding were significantly reduced. Due to the implementation of the project, the cultivated land area increased by 31%.

Evaluation of the AnnAGNPS model for predicting runoff and sediment yield in a small Mediterranean agricultural watershed in Navarre (Spain)

USDA-ARS?s Scientific Manuscript database

AnnAGNPS (Annualized Agricultural Non-Point Source Pollution Model) is a system of computer models developed to predict non-point source pollutant loadings within agricultural watersheds. It contains a daily time step distributed parameter continuous simulation surface runoff model designed to assis...

AN APPROACH TO WATER RESOURCES EVALUATION OF NON-POINT SILVICULTURAL SOURCES (A PROCEDURAL HANDBOOK)

EPA Science Inventory

This handbook provides an analysis methodology that can be used to describe and evaluate changes to the water resource resulting from non-point silvicultural activities. This state-of-the-art approach for analysis and prediction of pollution from non point silvicultural activitie...

Nutrient pressures and ecological responses to nutrient loading reductions in Danish streams, lakes and coastal waters

NASA Astrophysics Data System (ADS)

Kronvang, Brian; Jeppesen, Erik; Conley, Daniel J.; Søndergaard, Martin; Larsen, Søren E.; Ovesen, Niels B.; Carstensen, Jacob

2005-03-01

The Danish National Aquatic Monitoring and Assessment Programme (NOVA) was launched in 1988 following the adoption of the first Danish Action Plan on the Aquatic Environment in 1987 with the aim to reduce by 50% the nitrogen (N) loading and by 80% the phosphorus (P) loading to the aquatic environment. The 14 years of experience gathered from NOVA have shown that discharges of total N (TN) and P (TP) from point sources to the Danish Aquatic Environment have been reduced by 69% (N) and 82% (P) during the period 1989 2002. Consequently, the P concentration has decreased markedly in most Danish lakes and estuaries. Considerable changes in agricultural practice have resulted in a reduction of the net N-surplus from 136 to 88 kg N ha-1 yr-1 (41%) and the net P-surplus from 19 to 11 kg P ha-1 yr-1 (42%) during the period 1985 2002. Despite these efforts Danish agriculture is today the major source of both N (>80%) and P (>50%) in Danish streams, lakes and coastal waters. A non-parametric statistical trend analysis of TN concentrations in streams draining dominantly agricultural catchments has shown a significant (p<0.05) downward trend in 48 streams with the downward trend being stronger in loamy compared to sandy catchments, and more pronounced with increasing dominance of agricultural exploitation in the catchments. In contrast, a statistical trend analysis of TP concentrations in streams draining agricultural catchments did not reveal any significant trends. The large reduction in nutrient loading from point and non-point sources has in general improved the ecological conditions of Danish lakes in the form of increased summer Secchi depth, decreased chlorophyll a and reduced phytoplankton biomass. Major changes have also occurred in the fish communities in lakes, with positive cascading effects on water quality. In Danish estuaries and coastal waters only a few significant improvements in the ecological quality have been observed, although it is expected that the observed reduced nutrient concentrations are likely to improve the ecological quality of estuaries and coastal waters in Denmark in the long term.

Microbial Source Module (MSM): Documenting the Science and Software for Discovery, Evaluation, and Integration

EPA Science Inventory

The Microbial Source Module (MSM) estimates microbial loading rates to land surfaces from non-point sources, and to streams from point sources for each subwatershed within a watershed. A subwatershed, the smallest modeling unit, represents the common basis for information consume...

Study on the quantitative relationship between Agricultural water and fertilization process and non-point source pollution based on field experiments

NASA Astrophysics Data System (ADS)

Wang, H.; Chen, K.; Wu, Z.; Guan, X.

2017-12-01

In recent years, with the prominent of water environment problem and the relative increase of point source pollution governance, especially the agricultural non-point source pollution problem caused by the extensive use of fertilizers and pesticides has become increasingly aroused people's concern and attention. In order to reveal the quantitative relationship between agriculture water and fertilizer and non-point source pollution, on the basis of elm field experiment and combined with agricultural drainage irrigation model, the agricultural irrigation water and the relationship between fertilizer and fertilization scheme and non-point source pollution were analyzed and calculated by field emission intensity index. The results show that the variation of displacement varies greatly under different irrigation conditions. When the irrigation water increased from 22cm to 42cm, the irrigation water increased by 20 cm while the field displacement increased by 11.92 cm, about 66.22% of the added value of irrigation water. Then the irrigation water increased from 42 to 68, irrigation water increased 26 cm, and the field displacement increased by 22.48 cm, accounting for 86.46% of irrigation water. So there is an "inflection point" between the irrigation water amount and field displacement amount. The load intensity increases with the increase of irrigation water and shows a significant power correlation. Under the different irrigation condition, the increase amplitude of load intensity with the increase of irrigation water is different. When the irrigation water is smaller, the load intensity increase relatively less, and when the irrigation water increased to about 42 cm, the load intensity will increase considerably. In addition, there was a positive correlation between the fertilization and load intensity. The load intensity had obvious difference in different fertilization modes even with same fertilization level, in which the fertilizer field unit load intensity increased the most in July. The results provide some basis for the field control and management of agricultural non-point source pollution.

Seasonal variation of nitrogen-concentration in the surface water and its relationship with land use in a catchment of northern China.

PubMed

Chen, Li-ding; Peng, Hong-jia; Fu, Bo-Jie; Qiu, Jun; Zhang, Shu-rong

2005-01-01

Surface waters can be contaminated by human activities in two ways: (1) by point sources, such as sewage treatment discharge and storm-water runoff; and (2) by non-point sources, such as runoff from urban and agricultural areas. With point-source pollution effectively controlled, non-point source pollution has become the most important environmental concern in the world. The formation of non-point source pollution is related to both the sources such as soil nutrient, the amount of fertilizer and pesticide applied, the amount of refuse, and the spatial complex combination of land uses within a heterogeneous landscape. Land-use change, dominated by human activities, has a significant impact on water resources and quality. In this study, fifteen surface water monitoring points in the Yuqiao Reservoir Basin, Zunhua, Hebei Province, northern China, were chosen to study the seasonal variation of nitrogen concentration in the surface water. Water samples were collected in low-flow period (June), high-flow period (July) and mean-flow period (October) from 1999 to 2000. The results indicated that the seasonal variation of nitrogen concentration in the surface water among the fifteen monitoring points in the rainfall-rich year is more complex than that in the rainfall-deficit year. It was found that the land use, the characteristics of the surface river system, rainfall, and human activities play an important role in the seasonal variation of N-concentration in surface water.

40 CFR 430.127 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non.... Subpart L [PSNS for non-integrated mills where filter and non-woven papers are produced from purchased...

40 CFR 430.127 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non.... Subpart L [PSNS for non-integrated mills where filter and non-woven papers are produced from purchased...

A selective array activation method for the generation of a focused source considering listening position.

PubMed

Song, Min-Ho; Choi, Jung-Woo; Kim, Yang-Hann

2012-02-01

A focused source can provide an auditory illusion of a virtual source placed between the loudspeaker array and the listener. When a focused source is generated by time-reversed acoustic focusing solution, its use as a virtual source is limited due to artifacts caused by convergent waves traveling towards the focusing point. This paper proposes an array activation method to reduce the artifacts for a selected listening point inside an array of arbitrary shape. Results show that energy of convergent waves can be reduced up to 60 dB for a large region including the selected listening point. © 2012 Acoustical Society of America

ASSESSING NON-POINT SOURCES OF NITROGEN TO SMALL STREAMS IN THE SOUTH FORK BROAD RIVER WATERSHED (GEORGIA, USA)

EPA Science Inventory

The National Land Cover Data (NLCD) is a land cover classification derived from Landsat Thematic Mapper satellite data collected in the early to mid-1990s. In this work, land use coverages calculated from the NLCD database are used to assess the impact of non-point sources on the...

X-ray Point Source Populations in Spiral and Elliptical Galaxies

NASA Astrophysics Data System (ADS)

Colbert, E.; Heckman, T.; Weaver, K.; Ptak, A.; Strickland, D.

2001-12-01

In the years of the Einstein and ASCA satellites, it was known that the total hard X-ray luminosity from non-AGN galaxies was fairly well correlated with the total blue luminosity. However, the origin of this hard component was not well understood. Some possibilities that were considered included X-ray binaries, extended upscattered far-infrared light via the inverse-Compton process, extended hot 107 K gas (especially in ellipitical galaxies), or even an active nucleus. Now, for the first time, we know from Chandra images that a significant amount of the total hard X-ray emission comes from individual X-ray point sources. We present here spatial and spectral analyses of Chandra data for X-ray point sources in a sample of ~40 galaxies, including both spiral galaxies (starbursts and non-starbursts) and elliptical galaxies. We shall discuss the relationship between the X-ray point source population and the properties of the host galaxies. We show that the slopes of the point-source X-ray luminosity functions are different for different host galaxy types and discuss possible reasons why. We also present detailed X-ray spectral analyses of several of the most luminous X-ray point sources (i.e., IXOs, a.k.a. ULXs), and discuss various scenarios for the origin of the X-ray point sources.

40 CFR 430.125 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non-Woven, and... of 5.0 to 9.0 at all times. Subpart L [NSPS for non-integrated mills where filter and non-woven...

40 CFR 430.125 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non-Woven, and... of 5.0 to 9.0 at all times. Subpart L [NSPS for non-integrated mills where filter and non-woven...

Detection of spatial fluctuations of non-point source fecal pollution in coral reef surrounding waters in southwestern Puerto Rico using PCR-based assays.

PubMed

Bonkosky, M; Hernández-Delgado, E A; Sandoz, B; Robledo, I E; Norat-Ramírez, J; Mattei, H

2009-01-01

Human fecal contamination of coral reefs is a major cause of concern. Conventional methods used to monitor microbial water quality cannot be used to discriminate between different fecal pollution sources. Fecal coliforms, enterococci, and human-specific Bacteroides (HF183, HF134), general Bacteroides-Prevotella (GB32), and Clostridium coccoides group (CP) 16S rDNA PCR assays were used to test for the presence of non-point source fecal contamination across the southwestern Puerto Rico shelf. Inshore waters were highly turbid, consistently receiving fecal pollution from variable sources, and showing the highest frequency of positive molecular marker signals. Signals were also detected at offshore waters in compliance with existing microbiological quality regulations. Phylogenetic analysis showed that most isolates were of human fecal origin. The geographic extent of non-point source fecal pollution was large and impacted extensive coral reef systems. This could have deleterious long-term impacts on public health, local fisheries and in tourism potential if not adequately addressed.

Upwind MacCormack Euler solver with non-equilibrium chemistry

NASA Technical Reports Server (NTRS)

Sherer, Scott E.; Scott, James N.

1993-01-01

A computer code, designated UMPIRE, is currently under development to solve the Euler equations in two dimensions with non-equilibrium chemistry. UMPIRE employs an explicit MacCormack algorithm with dissipation introduced via Roe's flux-difference split upwind method. The code also has the capability to employ a point-implicit methodology for flows where stiffness is introduced through the chemical source term. A technique consisting of diagonal sweeps across the computational domain from each corner is presented, which is used to reduce storage and execution requirements. Results depicting one dimensional shock tube flow for both calorically perfect gas and thermally perfect, dissociating nitrogen are presented to verify current capabilities of the program. Also, computational results from a chemical reactor vessel with no fluid dynamic effects are presented to check the chemistry capability and to verify the point implicit strategy.

Legacy source of mercury in an urban stream-wetland ecosystem in central North Carolina, USA.

PubMed

Deonarine, Amrika; Hsu-Kim, Heileen; Zhang, Tong; Cai, Yong; Richardson, Curtis J

2015-11-01

In the United States, aquatic mercury contamination originates from point and non-point sources to watersheds. Here, we studied the contribution of mercury in urban runoff derived from historically contaminated soils and the subsequent production of methylmercury in a stream-wetland complex (Durham, North Carolina), the receiving water of this runoff. Our results demonstrated that the mercury originated from the leachate of grass-covered athletic fields. A fraction of mercury in this soil existed as phenylmercury, suggesting that mercurial anti-fungal compounds were historically applied to this soil. Further downstream in the anaerobic sediments of the stream-wetland complex, a fraction (up to 9%) of mercury was converted to methylmercury, the bioaccumulative form of the metal. Importantly, the concentrations of total mercury and methylmercury were reduced to background levels within the stream-wetland complex. Overall, this work provides an example of a legacy source of mercury that should be considered in urban watershed models and watershed management. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modelling of point and diffuse pollution: application of the Moneris model in the Ipojuca river basin, Pernambuco State, Brazil.

PubMed

de Lima Barros, Alessandra Maciel; do Carmo Sobral, Maria; Gunkel, Günter

2013-01-01

Emissions of pollutants and nutrients are causing several problems in aquatic ecosystems, and in general an excess of nutrients, specifically nitrogen and phosphorus, is responsible for the eutrophication process in water bodies. In most developed countries, more attention is given to diffuse pollution because problems with point pollution have already been solved. In many non-developed countries basic data for point and diffuse pollution are not available. The focus of the presented studies is to quantify nutrient emissions from point and diffuse sources in the Ipojuca river basin, Pernambuco State, Brazil, using the Moneris model (Modelling Nutrient Emissions in River Systems). This model has been developed in Germany and has already been implemented in more than 600 river basins. The model is mainly based on river flow, water quality and geographical information system data. According to the Moneris model results, untreated domestic sewage is the major source of nutrients in the Ipojuca river basin. The Moneris model has shown itself to be a useful tool that allows the identification and quantification of point and diffuse nutrient sources, thus enabling the adoption of measures to reduce them. The Moneris model, conducted for the first time in a tropical river basin with intermittent flow, can be used as a reference for implementation in other watersheds.

Envelope of coda waves for a double couple source due to non-linear elasticity

NASA Astrophysics Data System (ADS)

Calisto, Ignacia; Bataille, Klaus

2014-10-01

Non-linear elasticity has recently been considered as a source of scattering, therefore contributing to the coda of seismic waves, in particular for the case of explosive sources. This idea is analysed further here, theoretically solving the expression for the envelope of coda waves generated by a point moment tensor in order to compare with earthquake data. For weak non-linearities, one can consider each point of the non-linear medium as a source of scattering within a homogeneous and linear medium, for which Green's functions can be used to compute the total displacement of scattered waves. These sources of scattering have specific radiation patterns depending on the incident and scattered P or S waves, respectively. In this approach, the coda envelope depends on three scalar parameters related to the specific non-linearity of the medium; however these parameters only change the scale of the coda envelope. The shape of the coda envelope is sensitive to both the source time function and the intrinsic attenuation. We compare simulations using this model with data from earthquakes in Taiwan, with a good fit.

Multi-angle Indicators System of Non-point Pollution Source Assessment in Rural Areas: A Case Study Near Taihu Lake

NASA Astrophysics Data System (ADS)

Huang, Lei; Ban, Jie; Han, Yu Ting; Yang, Jie; Bi, Jun

2013-04-01

This study aims to identify key environmental risk sources contributing to water eutrophication and to suggest certain risk management strategies for rural areas. The multi-angle indicators included in the risk source assessment system were non-point source pollution, deficient waste treatment, and public awareness of environmental risk, which combined psychometric paradigm methods, the contingent valuation method, and personal interviews to describe the environmental sensitivity of local residents. Total risk values of different villages near Taihu Lake were calculated in the case study, which resulted in a geographic risk map showing which village was the critical risk source of Taihu eutrophication. The increased application of phosphorus (P) and nitrogen (N), loss vulnerability of pollutant, and a lack of environmental risk awareness led to more serious non-point pollution, especially in rural China. Interesting results revealed by the quotient between the scores of objective risk sources and subjective risk sources showed what should be improved for each study village. More environmental investments, control of agricultural activities, and promotion of environmental education are critical considerations for rural environmental management. These findings are helpful for developing targeted and effective risk management strategies in rural areas.

Regional Scale Simulations of Nitrate Leaching through Agricultural Soils of California

NASA Astrophysics Data System (ADS)

Diamantopoulos, E.; Walkinshaw, M.; O'Geen, A. T.; Harter, T.

2016-12-01

Nitrate is recognized as one of California's most widespread groundwater contaminants. As opposed to point sources, which are relative easily identifiable sources of contamination, non-point sources of nitrate are diffuse and linked with widespread use of fertilizers in agricultural soils. California's agricultural regions have an incredible diversity of soils that encompass a huge range of properties. This complicates studies dealing with nitrate risk assessment, since important biological and physicochemical processes appear at the first meters of the vadose zone. The objective of this study is to evaluate all agricultural soils in California according to their potentiality for nitrate leaching based on numerical simulations using the Richards equation. We conducted simulations for 6000 unique soil profiles (over 22000 soil horizons) taking into account the effect of climate, crop type, irrigation and fertilization management scenarios. The final goal of this study is to evaluate simple management methods in terms of reduced nitrate leaching. We estimated drainage rates of water under the root zone and nitrate concentrations in the drain water at the regional scale. We present maps for all agricultural soils in California which can be used for risk assessment studies. Finally, our results indicate that adoption of simple irrigation and fertilization methods may significantly reduce nitrate leaching in vulnerable regions.

[Multiple time scales analysis of spatial differentiation characteristics of non-point source nitrogen loss within watershed].

PubMed

Liu, Mei-bing; Chen, Xing-wei; Chen, Ying

2015-07-01

Identification of the critical source areas of non-point source pollution is an important means to control the non-point source pollution within the watershed. In order to further reveal the impact of multiple time scales on the spatial differentiation characteristics of non-point source nitrogen loss, a SWAT model of Shanmei Reservoir watershed was developed. Based on the simulation of total nitrogen (TN) loss intensity of all 38 subbasins, spatial distribution characteristics of nitrogen loss and critical source areas were analyzed at three time scales of yearly average, monthly average and rainstorms flood process, respectively. Furthermore, multiple linear correlation analysis was conducted to analyze the contribution of natural environment and anthropogenic disturbance on nitrogen loss. The results showed that there were significant spatial differences of TN loss in Shanmei Reservoir watershed at different time scales, and the spatial differentiation degree of nitrogen loss was in the order of monthly average > yearly average > rainstorms flood process. TN loss load mainly came from upland Taoxi subbasin, which was identified as the critical source area. At different time scales, land use types (such as farmland and forest) were always the dominant factor affecting the spatial distribution of nitrogen loss, while the effect of precipitation and runoff on the nitrogen loss was only taken in no fertilization month and several processes of storm flood at no fertilization date. This was mainly due to the significant spatial variation of land use and fertilization, as well as the low spatial variability of precipitation and runoff.

Convex Hull Aided Registration Method (CHARM).

PubMed

Fan, Jingfan; Yang, Jian; Zhao, Yitian; Ai, Danni; Liu, Yonghuai; Wang, Ge; Wang, Yongtian

2017-09-01

Non-rigid registration finds many applications such as photogrammetry, motion tracking, model retrieval, and object recognition. In this paper we propose a novel convex hull aided registration method (CHARM) to match two point sets subject to a non-rigid transformation. First, two convex hulls are extracted from the source and target respectively. Then, all points of the point sets are projected onto the reference plane through each triangular facet of the hulls. From these projections, invariant features are extracted and matched optimally. The matched feature point pairs are mapped back onto the triangular facets of the convex hulls to remove outliers that are outside any relevant triangular facet. The rigid transformation from the source to the target is robustly estimated by the random sample consensus (RANSAC) scheme through minimizing the distance between the matched feature point pairs. Finally, these feature points are utilized as the control points to achieve non-rigid deformation in the form of thin-plate spline of the entire source point set towards the target one. The experimental results based on both synthetic and real data show that the proposed algorithm outperforms several state-of-the-art ones with respect to sampling, rotational angle, and data noise. In addition, the proposed CHARM algorithm also shows higher computational efficiency compared to these methods.

Woodchip bioreactors effectively treat aquaculture effluent

USDA-ARS?s Scientific Manuscript database

Nutrients, in particular nitrogen and phosphorus, can create eutrophication problems in any watershed. Preventing water quality impairment requires controlling nutrients from both point-source and non-point source discharges. Woodchip bioreactors are one relatively new approach that can be utilized ...

Analysis of non-point and point source pollution in China: case study in Shima Watershed in Guangdong Province

NASA Astrophysics Data System (ADS)

Fang, Huaiyang; Lu, Qingshui; Gao, Zhiqiang; Shi, Runhe; Gao, Wei

2013-09-01

China economy has been rapidly increased since 1978. Rapid economic growth led to fast growth of fertilizer and pesticide consumption. A significant portion of fertilizers and pesticides entered the water and caused water quality degradation. At the same time, rapid economic growth also caused more and more point source pollution discharge into the water. Eutrophication has become a major threat to the water bodies. Worsening environment problems forced governments to take measures to control water pollution. We extracted land cover from Landsat TM images; calculated point source pollution with export coefficient method; then SWAT model was run to simulate non-point source pollution. We found that the annual TP loads from industry pollution into rivers are 115.0 t in the entire watershed. Average annual TP loads from each sub-basin ranged from 0 to 189.4 ton. Higher TP loads of each basin from livestock and human living mainly occurs in the areas where they are far from large towns or cities and the TP loads from industry are relatively low. Mean annual TP loads that delivered to the streams was 246.4 tons and the highest TP loads occurred in north part of this area, and the lowest TP loads is mainly distributed in middle part. Therefore, point source pollution has much high proportion in this area and governments should take measures to control point source pollution.

Establishing strategies for a transportation MS4 : [technology transfer summary].

DOT National Transportation Integrated Search

2015-05-01

The National Pollutant Discharge Elimination System (NPDES) was established by the U.S. : Environmental Protection Agency as a means of addressing surface pollution from both known : (point) and non-specific (non-point) sources. The program impacts i...

Monitor-based evaluation of pollutant load from urban stormwater runoff in Beijing.

PubMed

Liu, Y; Che, W; Li, J

2005-01-01

As a major pollutant source to urban receiving waters, the non-point source pollution from urban runoff needs to be well studied and effectively controlled. Based on monitoring data from urban runoff pollutant sources, this article describes a systematic estimation of total pollutant loads from the urban areas of Beijing. A numerical model was developed to quantify main pollutant loads of urban runoff in Beijing. A sub-procedure is involved in this method, in which the flush process influences both the quantity and quality of stormwater runoff. A statistics-based method was applied in computing the annual pollutant load as an output of the runoff. The proportions of pollutant from point-source and non-point sources were compared. This provides a scientific basis for proper environmental input assessment of urban stormwater pollution to receiving waters, improvement of infrastructure performance, implementation of urban stormwater management, and utilization of stormwater.

Study on road surface source pollution controlled by permeable pavement

NASA Astrophysics Data System (ADS)

Zheng, Chaocheng

2018-06-01

The increase of impermeable pavement in urban construction not only increases the runoff of the pavement, but also produces a large number of Non-Point Source Pollution. In the process of controlling road surface runoff by permeable pavement, a large number of particulate matter will be withheld when rainwater is being infiltrated, so as to control the source pollution at the source. In this experiment, we determined the effect of permeable road surface to remove heavy pollutants in the laboratory and discussed the related factors that affect the non-point pollution of permeable pavement, so as to provide a theoretical basis for the application of permeable pavement.

Relative importance of wastewater treatment plants and non-point sources of perfluorinated compounds to Washington State rivers.

PubMed

Furl, Chad V; Meredith, Callie A; Strynar, Mark J; Nakayama, Shoji F

2011-07-01

Perfluorinated compounds (PFCs) were measured in 10 Washington State rivers and 4 wastewater treatment plants (WWTPs) under periods of low and high flows to investigate the relative importance of point and non-point sources to rivers. PFCs were detected in all samples with summed values ranging from 1.11 to 74.9 ng/L in surface waters and 62.3-418 ng/L in WWTP effluent. Concentrations in 6 of the 10 rivers exhibited a positive relationship with flow, indicating runoff as a contributing source, with PFC loads greatest at all 10 waterbodies during high flows. Perfluoroheptanoic acid:perfluorooctanoic acid homologue ratios suggest atmospheric contributions to the waterbodies are important throughout the year. Principal component analysis (PCA) indicated distinct homologue profiles for high flow, low flow, and effluent samples. The PCA demonstrates that during the spring when flows and loads are at their greatest; WWTP discharges are not the primary sources of PFCs to the river systems. Taken together, the evidence provided signifies non-point inputs are a major pathway for PFCs to surface waters in Washington State. Copyright © 2011 Elsevier B.V. All rights reserved.

Major and Trace Element Fluxes to the Ganges River: Significance of Small Flood Plain Tributary as Non-Point Pollution Source

NASA Astrophysics Data System (ADS)

Lakshmi, V.; Sen, I. S.; Mishra, G.

2017-12-01

There has been much discussion amongst biologists, ecologists, chemists, geologists, environmental firms, and science policy makers about the impact of human activities on river health. As a result, multiple river restoration projects are on going on many large river basins around the world. In the Indian subcontinent, the Ganges River is the focal point of all restoration actions as it provides food and water security to half a billion people. Serious concerns have been raised about the quality of Ganga water as toxic chemicals and many more enters the river system through point-sources such as direct wastewater discharge to rivers, or non-point-sources. Point source pollution can be easily identified and remedial actions can be taken; however, non-point pollution sources are harder to quantify and mitigate. A large non-point pollution source in the Indo-Gangetic floodplain is the network of small floodplain rivers. However, these rivers are rarely studied since they are small in catchment area ( 1000-10,000 km2) and discharge (<100 m3/s). As a result, the impact of these small floodplain rivers on the dissolved chemical load of large river systems is not constrained. To fill this knowledge gap we have monitored the Pandu River for one year between February 2015 and April 2016. Pandu river is 242 km long and is a right bank tributary of Ganges with a total catchment area of 1495 km2. Water samples were collected every month for dissolved major and trace elements. Here we show that the concentration of heavy metals in river Pandu is in higher range as compared to the world river average, and all the dissolved elements shows a large spatial-temporal variation. We show that the Pandu river exports 192170, 168517, 57802, 32769, 29663, 1043, 279, 241, 225, 162, 97, 28, 25, 22, 20, 8, 4 Kg/yr of Ca, Na, Mg, K, Si, Sr, Zn, B, Ba, Mn, Al, Li, Rb, Mo, U, Cu, and Sb, respectively, to the Ganga river, and the exported chemical flux effects the water chemistry of the Ganga river downstream of its confluence point. We further speculate that small floodplain rivers is an important source that contributes to the dissolved chemical budget of large river systems, and they must be better monitored to address future challenges in river basin management.

Differentiating Impacts of Watershed Development from Superfund Sites on Stream Macroinvertebrates

EPA Science Inventory

Urbanization effect models were developed and verified at whole watershed scales to predict and differentiate between effects on aquatic life from diffuse, non-point source (NPS) urbanization in the watershed and effects of known local, site-specific origin point sources, contami...

Nonstationary time series analysis of surface water microbial pathogen population dynamics using cointegration methods

EPA Science Inventory

Background/Question/Methods Bacterial pathogens in surface water present disease risks to aquatic communities and for human recreational activities. Sources of these pathogens include runoff from urban, suburban, and agricultural point and non-point sources, but hazardous micr...

Pathway Ranking for In-place Sediment Management (CU1209). Executive Summary and Site 1 Report -- Paleta Creek

DTIC Science & Technology

2006-06-01

to any specific commercial product , process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or...conditions observed at P17 and Southeast Loch are interesting from the standpoint that these areas are generally closer to industrial and non-point...metals that commonly co-occur in both industrial sources and non-point source. An examination of all fluxes suggests that the surface mixed layer may

Simulation on Change Law of Runoff, Sediment and Non-point Source Nitrogen and Phosphorus Discharge under Different Land uses Based on SWAT Model: A Case Study of Er hai Lake Small Watershed

NASA Astrophysics Data System (ADS)

Tong, Xiao Xia; Lai Cui, Yuan; Chen, Man Yu; Hu, Bo; Xu, Wen Sheng

2018-05-01

The Er yuan watershed of Er hai district is chosen as the research area, the law of runoff and sediment and non-point source nitrogen and phosphorus discharges under different land uses during 2001 to 2014 are simulated based on SWAT model. Results of simulation indicate that the order of total runoff yield of different land use type from high to low is grassland, paddy fields, dry land. Specifically, the order of surface runoff yield from high to low is paddy fields, dry land, grassland, the order of lateral runoff yield from high to low is paddy fields, dry land, grassland, the order of groundwater runoff yield from high to low is grassland, paddy fields, dry land. The orders of sediment and nitrogen and phosphorus yield per unit area of different land use type are the same, grassland> paddy fields> dry land. It can be seen, nitrogen and phosphorus discharges from paddy fields and dry land are the main sources of agricultural non-point pollution of the irrigated area. Therefore, reasonable field management measures which can decrease the discharge of nitrogen and phosphorus of paddy fields and dry land are the key to agricultural non-point source pollution prevention and control.

Linearization of Positional Response Curve of a Fiber-optic Displacement Sensor

NASA Astrophysics Data System (ADS)

Babaev, O. G.; Matyunin, S. A.; Paranin, V. D.

2018-01-01

Currently, the creation of optical measuring instruments and sensors for measuring linear displacement is one of the most relevant problems in the area of instrumentation. Fiber-optic contactless sensors based on the magneto-optical effect are of special interest. They are essentially contactless, non-electrical and have a closed optical channel not subject to contamination. The main problem of this type of sensors is the non-linearity of their positional response curve due to the hyperbolic nature of the magnetic field intensity variation induced by moving the magnetic source mounted on the controlled object relative to the sensing element. This paper discusses an algorithmic method of linearizing the positional response curve of fiber-optic displacement sensors in any selected range of the displacements to be measured. The method is divided into two stages: 1 - definition of the calibration function, 2 - measurement and linearization of the positional response curve (including its temperature stabilization). The algorithm under consideration significantly reduces the number of points of the calibration function, which is essential for the calibration of temperature dependence, due to the use of the points that randomly deviate from the grid points with uniform spacing. Subsequent interpolation of the deviating points and piecewise linear-plane approximation of the calibration function reduces the microcontroller storage capacity for storing the calibration function and the time required to process the measurement results. The paper also presents experimental results of testing real samples of fiber-optic displacement sensors.

An improved DPSM technique for modelling ultrasonic fields in cracked solids

NASA Astrophysics Data System (ADS)

Banerjee, Sourav; Kundu, Tribikram; Placko, Dominique

2007-04-01

In recent years Distributed Point Source Method (DPSM) is being used for modelling various ultrasonic, electrostatic and electromagnetic field modelling problems. In conventional DPSM several point sources are placed near the transducer face, interface and anomaly boundaries. The ultrasonic or the electromagnetic field at any point is computed by superimposing the contributions of different layers of point sources strategically placed. The conventional DPSM modelling technique is modified in this paper so that the contributions of the point sources in the shadow region can be removed from the calculations. For this purpose the conventional point sources that radiate in all directions are replaced by Controlled Space Radiation (CSR) sources. CSR sources can take care of the shadow region problem to some extent. Complete removal of the shadow region problem can be achieved by introducing artificial interfaces. Numerically synthesized fields obtained by the conventional DPSM technique that does not give any special consideration to the point sources in the shadow region and the proposed modified technique that nullifies the contributions of the point sources in the shadow region are compared. One application of this research can be found in the improved modelling of the real time ultrasonic non-destructive evaluation experiments.

Monitoring Fecal Indicators and Pathogens in Watersheds: Implementing a Quantitative Microbial Risk Assessment Approach

EPA Science Inventory

- Many of the nation's rivers, lakes, and estuaries are impaired with fecal indicator bacteria. - Fecal contamination from point and non-point sources is responsible for the presence of fecal pathogens in source and recreational waters - Effective compliance with TMDL regulatio...

A prototype for understanding the effects of TMDL standards: Tying property values to sediment loads in the Lake Tahoe Basin

USGS Publications Warehouse

Tracy, J.C.; Bernknopf, R.; Forney, W.; Hill, K.

2004-01-01

The Federal Clean Water Act (Section 303(d)) mandates that states develop Total Maximum Daily Load (TMDL) plans for water bodies that are on the Section 303(d) list. To be placed on the 303(d) list, a water body must be found to have water quality conditions that limit its ability to meet its designated beneficial uses. The TMDL for a water body is defined in 40 CFR 130 as the sum of waste load allocations from identified points sources and non-point sources within the water body's watershed. The TMDL plan for a listed water body should identify the current waste loads to the water body, the waste load capacity of the water body and then allocate the waste load capacity to the known point and non-point sources of pollution within the water body's watershed. Copyright 2004 ASCE.

An Analysis of the Use of Energy Audits, Solar Panels, and Wind Turbines to Reduce Energy Consumption from Non Renewable Energy Sources

DTIC Science & Technology

2015-04-15

the Use of Energy Audits, Solar Panels, and Wind Turbines to Reduce Energy Consumption from Non Renewable Energy Sources Energy is a National...Park, NC 27709-2211 Energy Audits, Energy Conservation, Renewable Energy, Solar Energy, Wind Turbine Use, Energy Consumption REPORT DOCUMENTATION PAGE 11...in non peer-reviewed journals: An Analysis of the Use of Energy Audits, Solar Panels, and Wind Turbines to Reduce Energy Consumption from Non

[Regulation framework of watershed landscape pattern for non-point source pollution control based on 'source-sink' theory: A case study in the watershed of Maluan Bay, Xiamen City, China].

PubMed

Huang, Ning; Wang, Hong Ying; Lin, Tao; Liu, Qi Ming; Huang, Yun Feng; Li, Jian Xiong

2016-10-01

Watershed landscape pattern regulation and optimization based on 'source-sink' theory for non-point source pollution control is a cost-effective measure and still in the exploratory stage. Taking whole watershed as the research object, on the basis of landscape ecology, related theories and existing research results, a regulation framework of watershed landscape pattern for non-point source pollution control was developed at two levels based on 'source-sink' theory in this study: 1) at watershed level: reasonable basic combination and spatial pattern of 'source-sink' landscape was analyzed, and then holistic regulation and optimization method of landscape pattern was constructed; 2) at landscape patch level: key 'source' landscape was taken as the focus of regulation and optimization. Firstly, four identification criteria of key 'source' landscape including landscape pollutant loading per unit area, landscape slope, long and narrow transfer 'source' landscape, pollutant loading per unit length of 'source' landscape along the riverbank were developed. Secondly, nine types of regulation and optimization methods for different key 'source' landscape in rural and urban areas were established, according to three regulation and optimization rules including 'sink' landscape inlay, banding 'sink' landscape supplement, pollutants capacity of original 'sink' landscape enhancement. Finally, the regulation framework was applied for the watershed of Maluan Bay in Xiamen City. Holistic regulation and optimization mode of watershed landscape pattern of Maluan Bay and key 'source' landscape regulation and optimization measures for the three zones were made, based on GIS technology, remote sensing images and DEM model.

40 CFR 430.123 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non-Woven, and Paperboard From Purchased Pulp Subcategory § 430.123 Effluent... existing point source subject to this subpart shall achieve the following effluent limitations representing...

Delineating Contaminants and Transport Pathways Within a Coastal Watershed in Southeast Puerto Rico

USDA-ARS?s Scientific Manuscript database

Coastal water quality decline due to point and non-point source pollution from terrestrial sources is a serious concern throughout the Caribbean basin and worldwide. Toxic and noxious algal blooms, declines in mangrove forests and seagrass meadows, depletion of fishery stocks, coral reef die-off, pu...

Web-based Communication of Water Quality Issues and Potential Solution Exploration

EPA Science Inventory

Many United States water bodies are impaired, i.e., do not meet applicable water quality standards. Pollutants enter water bodies from point sources (PS) and non-point sources (NPS). Loadings from PS are regulated by the Clean Water Act and permits limit them. Loadings from NPS a...

Estimation of source location and ground impedance using a hybrid multiple signal classification and Levenberg-Marquardt approach

NASA Astrophysics Data System (ADS)

Tam, Kai-Chung; Lau, Siu-Kit; Tang, Shiu-Keung

2016-07-01

A microphone array signal processing method for locating a stationary point source over a locally reactive ground and for estimating ground impedance is examined in detail in the present study. A non-linear least square approach using the Levenberg-Marquardt method is proposed to overcome the problem of unknown ground impedance. The multiple signal classification method (MUSIC) is used to give the initial estimation of the source location, while the technique of forward backward spatial smoothing is adopted as a pre-processer of the source localization to minimize the effects of source coherence. The accuracy and robustness of the proposed signal processing method are examined. Results show that source localization in the horizontal direction by MUSIC is satisfactory. However, source coherence reduces drastically the accuracy in estimating the source height. The further application of Levenberg-Marquardt method with the results from MUSIC as the initial inputs improves significantly the accuracy of source height estimation. The present proposed method provides effective and robust estimation of the ground surface impedance.

Semi-Tomographic Gamma Scanning Technique for Non-Destructive Assay of Radioactive Waste Drums

NASA Astrophysics Data System (ADS)

Gu, Weiguo; Rao, Kaiyuan; Wang, Dezhong; Xiong, Jiemei

2016-12-01

Segmented gamma scanning (SGS) and tomographic gamma scanning (TGS) are two traditional detection techniques for low and intermediate level radioactive waste drum. This paper proposes one detection method named semi-tomographic gamma scanning (STGS) to avoid the poor detection accuracy of SGS and shorten detection time of TGS. This method and its algorithm synthesize the principles of SGS and TGS. In this method, each segment is divided into annual voxels and tomography is used in the radiation reconstruction. The accuracy of STGS is verified by experiments and simulations simultaneously for the 208 liter standard waste drums which contains three types of nuclides. The cases of point source or multi-point sources, uniform or nonuniform materials are employed for comparison. The results show that STGS exhibits a large improvement in the detection performance, and the reconstruction error and statistical bias are reduced by one quarter to one third or less for most cases if compared with SGS.

Effects of Source- versus Household Contamination of Tubewell Water on Child Diarrhea in Rural Bangladesh: A Randomized Controlled Trial

PubMed Central

Unicomb, Leanne; Arnold, Benjamin F.; Colford Jr., John M.; Luby, Stephen P.

2015-01-01

Background Shallow tubewells are the primary drinking water source for most rural Bangladeshis. Fecal contamination has been detected in tubewells, at low concentrations at the source and at higher levels at the point of use. We conducted a randomized controlled trial to assess whether improving the microbiological quality of tubewell drinking water by household water treatment and safe storage would reduce diarrhea in children <2 years in rural Bangladesh. Methods We randomly assigned 1800 households with a child aged 6-18 months (index child) into one of three arms: chlorine plus safe storage, safe storage and control. We followed households with monthly visits for one year to promote the interventions, track their uptake, test participants’ source and stored water for fecal contamination, and record caregiver-reported child diarrhea prevalence (primary outcome). To assess reporting bias, we also collected data on health outcomes that are not expected to be impacted by our interventions. Findings Both interventions had high uptake. Safe storage, alone or combined with chlorination, reduced heavy contamination of stored water. Compared to controls, diarrhea in index children was reduced by 36% in the chlorine plus safe storage arm (prevalence ratio, PR = 0.64, 0.55-0.73) and 31% in the safe storage arm (PR = 0.69, 0.60-0.80), with no difference between the two intervention arms. One limitation of the study was the non-blinded design with self-reported outcomes. However, the prevalence of health outcomes not expected to be impacted by water interventions did not differ between study arms, suggesting minimal reporting bias. Conclusions Safe storage significantly improved drinking water quality at the point of use and reduced child diarrhea in rural Bangladesh. There was no added benefit from combining safe storage with chlorination. Efforts should be undertaken to implement and evaluate long-term efforts for safe water storage in Bangladesh. Trial Registration ClinicalTrials.gov NCT01350063 PMID:25816342

Multi-rate, real time image compression for images dominated by point sources

NASA Technical Reports Server (NTRS)

Huber, A. Kris; Budge, Scott E.; Harris, Richard W.

1993-01-01

An image compression system recently developed for compression of digital images dominated by point sources is presented. Encoding consists of minimum-mean removal, vector quantization, adaptive threshold truncation, and modified Huffman encoding. Simulations are presented showing that the peaks corresponding to point sources can be transmitted losslessly for low signal-to-noise ratios (SNR) and high point source densities while maintaining a reduced output bit rate. Encoding and decoding hardware has been built and tested which processes 552,960 12-bit pixels per second at compression rates of 10:1 and 4:1. Simulation results are presented for the 10:1 case only.

Reducing soil erosion and nutrient loss on sloping land under crop-mulberry management system.

PubMed

Fan, Fangling; Xie, Deti; Wei, Chaofu; Ni, Jiupai; Yang, John; Tang, Zhenya; Zhou, Chuan

2015-09-01

Sloping croplands could result in soil erosion, which leads to non-point source pollution of the aquatic system in the Three Gorges Reservoir Region. Mulberry, a commonly grown cash plant in the region, is traditionally planted in contour hedgerows as an effective management practice to control soil erosion and non-point source pollution. In this field study, surface runoff and soil N and P loss on sloping land under crop-mulberry management were investigated. The experiments consisted of six crop-mulberry treatments: Control (no mulberry hedgerow with mustard-corn rotation); T1 (two-row contour mulberry with mustard-corn rotation); T2 (three-row contour mulberry with mustard-corn rotation); T3 (border mulberry and one-row contour mulberry with mustard-corn rotation); T4 (border mulberry with mustard-corn rotation); T5 (two-row longitudinal mulberry with mustard). The results indicated that crop-mulberry systems could effectively reduce surface runoff and soil and nutrient loss from arable slope land. Surface runoff from T1 (342.13 m(3) hm(-2)), T2 (260.6 m(3) hm(-2)), T3 (113.13 m(3) hm(-2)), T4 (114 m(3) hm(-2)), and T5 (129 m(3) hm(-2)) was reduced by 15.4, 35.6, 72.0, 71.8, and 68.1%, respectively, while soil loss from T1 (0.21 t hm(-2)), T2 (0.13 t hm(-2)), T3 (0.08 t hm(-2)), T4 (0.11 t hm(-2)), and T5 (0.12 t hm(-2)) was reduced by 52.3, 70.5, 81.8, 75.0, and 72.7%, respectively, as compared with the control. Crop-mulberry ecosystem would also elevate soil N by 22.3% and soil P by 57.4%, and soil nutrient status was contour-line dependent.

Analysis of Temporal and Spatial Distributions of Ammonia Nitrogen in the Huaihe River Basin from 1998 to 2014

NASA Astrophysics Data System (ADS)

Xu, J.; Jin, G.; Tang, H.; Li, L.

2016-12-01

To assess the effectiveness of water pollution control measures taken in the Huaihe River Basin (HRB) in China, we analyzed the temporal and spatial distributions of ammonia nitrogen (NH3-N) in the river water from 1998 to 2014 (three Chinese Five-year Plan periods).Analysis of measured NH3-N concentrations from various monitoring stations using the STL (seasonal trend decomposition using loess) method and a modified log-linear model revealed that: (1) The rate of NH3-N concentration reduction over the whole period was 70% 81% in the main stream of Huaihe River, but reached 88% in two major tributaries - the Shaying River and Guo River. (2) The NH3-N concentrations decreased significantly particularly between the tenth Five-year Plan and eleventh Five-year Plan periods in the main stream. In comparison, significant NH3-N reduction occurred over all three Five-year Plan periods in the Shaying and Guo tributaries. The concentration in the first year of a Five-year Plan period tended to much higher than that in the last year of the same period, likely due to the difference in implementing the pollution control measures. (3) The NH3-N concentrations were higher in the spring (fertilization period) and winter (low discharge) than in the summer and autumn. (4) With the implementation of pollution control measures, the contribution rate of NH3-N in the two major tributaries from point sources has decreased from 74% 93% in earlier years to 3% 28% in later years. However, NH3-N input from non-point sources appeared to remain stable and largely depend on runoff. To further reduce the NH3-N concentration in the river, policies and control measures should focus on non-point sources.

40 CFR 430.107 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Secondary Fiber Non...: Subpart J [PSNS for secondary fiber non-deink facilities where paperboard from wastepaper is produced... = wastewater discharged in kgal per ton of product. a The following equivalent mass limitations are provided as...

40 CFR 430.107 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Secondary Fiber Non...: Subpart J [PSNS for secondary fiber non-deink facilities where paperboard from wastepaper is produced... = wastewater discharged in kgal per ton of product. a The following equivalent mass limitations are provided as...

Overview of on-farm bioremediation systems to reduce the occurrence of point source contamination.

PubMed

De Wilde, Tineke; Spanoghe, Pieter; Debaer, Christof; Ryckeboer, Jaak; Springael, Dirk; Jaeken, Peter

2007-02-01

Contamination of ground and surface water puts pressure on the use of pesticides. Pesticide contamination of water can often be linked to point sources rather than to diffuse sources. Examples of such point sources are areas on farms where pesticides are handled and filled into sprayers, and where sprayers are cleaned. To reduce contamination from these point sources, different kinds of bioremediation system are being researched in various member states of the EU. Bioremediation is the use of living organisms, primarily microorganisms, to degrade the environmental contaminants into less toxic forms. The systems available for biocleaning of pesticides vary according to their shape and design. Up till now, three systems have been extensively described and reported: the biobed, the Phytobac and the biofilter. Most of these constructions are excavations or different sizes of container filled with biological material. Typical overall clean-up efficiency exceeds 95%, realising even more than 99% in many cases. This paper provides an overview of the state of the art of these bioremediation systems and discusses their construction, efficiency and drawbacks.

Microbial Source Module (MSM): Documenting the Science ...

EPA Pesticide Factsheets

The Microbial Source Module (MSM) estimates microbial loading rates to land surfaces from non-point sources, and to streams from point sources for each subwatershed within a watershed. A subwatershed, the smallest modeling unit, represents the common basis for information consumed and produced by the MSM which is based on the HSPF (Bicknell et al., 1997) Bacterial Indicator Tool (EPA, 2013b, 2013c). Non-point sources include numbers, locations, and shedding rates of domestic agricultural animals (dairy and beef cows, swine, poultry, etc.) and wildlife (deer, duck, raccoon, etc.). Monthly maximum microbial storage and accumulation rates on the land surface, adjusted for die-off, are computed over an entire season for four land-use types (cropland, pasture, forest, and urbanized/mixed-use) for each subwatershed. Monthly point source microbial loadings to instream locations (i.e., stream segments that drain individual sub-watersheds) are combined and determined for septic systems, direct instream shedding by cattle, and POTWs/WWTPs (Publicly Owned Treatment Works/Wastewater Treatment Plants). The MSM functions within a larger modeling system that characterizes human-health risk resulting from ingestion of water contaminated with pathogens. The loading estimates produced by the MSM are input to the HSPF model that simulates flow and microbial fate/transport within a watershed. Microbial counts within recreational waters are then input to the MRA-IT model (Soller et

Monitoring coastal marine waters for spore-forming bacteria of faecal and soil origin to determine point from non-point source pollution.

PubMed

Fujioka, R S

2001-01-01

The US Environmental Protection Agency (USEPA) and the World Health Organization (WHO) have established recreational water quality standards limiting the concentrations of faecal indicator bacteria (faecal coliform, E. coli, enterococci) to ensure that these waters are safe for swimming. In the application of these hygienic water quality standards, it is assumed that there are no significant environmental sources of these faecal indicator bacteria which are unrelated to direct faecal contamination. However, we previously reported that these faecal indicator bacteria are able to grow in the soil environment of humid tropical island environments such as Hawaii and Guam and are transported at high concentrations into streams and storm drains by rain. Thus, streams and storm drains in Hawaii contain consistently high concentrations of faecal indicator bacteria which routinely exceed the EPA and WHO recreational water quality standards. Since, streams and storm drains eventually flow out to coastal marine waters, we hypothesize that all the coastal beaches which receive run-off from streams and storm drains will contain elevated concentrations of faecal indicator bacteria. To test this hypothesis, we monitored the coastal waters at four beaches known to receive water from stream or storm drains for salinity, turbidity, and used the two faecal indicator bacteria (E. coli, enterococci) to establish recreational water quality standards. To determine if these coastal waters are contaminated with non-point source pollution (streams) or with point source pollution (sewage effluent), these same water samples were also assayed for spore-forming bacteria of faecal origin (Cl. perfringens) and of soil origin (Bacillus species). Using this monitoring strategy it was possible to determine when coastal marine waters were contaminated with non-point source pollution and when coastal waters were contaminated with point source pollution. The results of this study are most likely applicable to all countries in the warm and humid region of the world.

Selectivity of physiotherapist programs in the United States does not differ by institutional funding source or research activity level.

PubMed

Riley, Sean P; Covington, Kyle; Landry, Michel D; McCallum, Christine; Engelhard, Chalee; Cook, Chad E

2016-01-01

This study aimed to compare selectivity characteristics among institution characteristics to determine differences by institutional funding source (public vs. private) or research activity level (research vs. non-research). This study included information provided by the Commission on Accreditation in Physical Therapy Education (CAPTE) and the Federation of State Boards of Physical Therapy. Data were extracted from all students who graduated in 2011 from accredited physical therapy programs in the United States. The public and private designations of the institutions were extracted directly from the classifications from the 'CAPTE annual accreditation report,' and high and low research activity was determined based on Carnegie classifications. The institutions were classified into four groups: public/research intensive, public/non-research intensive, private/research intensive, and private/non-research intensive. Descriptive and comparison analyses with post hoc testing were performed to determine whether there were statistically significant differences among the four groups. Although there were statistically significant baseline grade point average differences among the four categorized groups, there were no significant differences in licensure pass rates or for any of the selectivity variables of interest. Selectivity characteristics did not differ by institutional funding source (public vs. private) or research activity level (research vs. non-research). This suggests that the concerns about reduced selectivity among physiotherapy programs, specifically the types that are experiencing the largest proliferation, appear less warranted.

Magnitudes, nature, and effects of point and nonpoint discharges in the Chattahoochee River Basin, Atlanta to West Point Dam, Georgia

USGS Publications Warehouse

Stamer, J.K.; Cherry, Rodney N.; Faye, R.E.; Kleckner, R.L.

1979-01-01

During the period April 1975 to June 1978, the U.S. Geological Survey conducted a river-quality assessment of the Upper Chattahoochee River basin in Georgia. One objective of the study was to assess the magnitudes, nature, and effects of point and non-point discharges in the Chattahoochee River basin from Atlanta to the West Point Dam. On an average annual basis and during the storm period of March 1215, 1976, non-point-source loads for most constituents analyzed were larger than point-source loads at the Whitesburg station, located on the Chattahoochee River about 40 river miles downstream of Atlanta. Most of the non-point-source constituent loads in the Atlanta-to-Whitesburg reach were from urban areas. Average annual point-source discharges accounted for about 50 percent of the dissolved nitrogen, total nitrogen, and total phosphorus loads, and about 70 percent of the dissolved phosphorus loads at Whitesburg. During weekends, power generation at the upstream Buford Dam hydroelectric facility is minimal. Streamflow at the Atlanta station during dry-weather weekends is estimated to be about 1,200 ft3/s (cubic feet per second). Average daily dissolved-oxygen concentrations of less than 5.0 mg/L (milligrams per liter) occurred often in the river, about 20 river miles downstream from Atlanta during these periods from May to November. During a low-flow period, June 1-2, 1977, five municipal point sources contributed 63 percent of the ultimate biochemical oxygen demand, 97 percent of the ammonium nitrogen, 78 percent of the total nitrogen, and 90 percent of the total phosphorus loads at the Franklin station, at the upstream end of West Point Lake. Average daily concentrations of 13 mg/L of ultimate biochemical oxygen demand and 1.8 mg/L of ammonium nitrogen were observed about 2 river miles downstream from two of the municipal point sources. Carbonaceous and nitrogenous oxygen demands caused dissolved-oxygen concentrations between 4.1 and 5.0 mg/L to occur in a 22-mile reach of the river downstream from Atlanta. Nitrogenous oxygen demands were greater than carbonaceous oxygen demands in the reach from river mile 303 to 271, and carbonaceous demands were greater from river mile 271 to 235. The heat load from the Atkinson-McDonough thermoelectric power-plants caused a decrease in the dissolved-oxygen concentrations of about 0.2 mg/L. During a critical low-flow period, a streamflow at Atlanta of about 1,800 ft3/s, with present (1977) point-source flows of 185 ft3/s containing concentrations of 45 mg/L of ultimate biochemical oxygen demand and 15 mg/L of ammonium nitrogen, results in a computed minimum dissolved-oxygen concentration of 4.7 mg/L in the river downstream from Atlanta. In the year 2000, a streamflow at Atlanta of about 1,800 ft3/s with point-source flows of 373 ft3/s containing concentrations of 45 mg/L of ultimate biochemical oxygen demand and 5.0 mg/L of ammonium nitrogen, will result in a computed minimum dissolved-oxygen concentration of 5.0 mg/L. A streamflow of about 1,050 ft3/s at Atlanta in the year 2000 will result in a dissolved-oxygen concentration of 5.0 mg/L if point-source flows contain concentrations of 15 mg/L of ultimate biochemical oxygen demand and 5.0 mg/L of ammonium nitrogen. Phytoplankton concentrations in West Point Lake, about 70 river miles downstream from Atlanta, could exceed 3 million cells per milliliter during extended low-flow periods in the summer with present point- and non-point-source nitrogen and phosphorus loads. In the year 2000, phytoplankton concentrations in West Point Lake are not likely to exceed 700,000 cells per milliliter during extended low-flow periods in the summer, if phosphorus concentrations do not exceed 1.0 mg/L in point-source discharges.

Development of Load Duration Curve System in Data Scarce Watersheds Based on a Distributed Hydrological Model

NASA Astrophysics Data System (ADS)

WANG, J.

2017-12-01

In stream water quality control, the total maximum daily load (TMDL) program is very effective. However, the load duration curves (LDC) of TMDL are difficult to be established because no sufficient observed flow and pollutant data can be provided in data-scarce watersheds in which no hydrological stations or consecutively long-term hydrological data are available. Although the point sources or a non-point sources of pollutants can be clarified easily with the aid of LDC, where does the pollutant come from and to where it will be transported in the watershed cannot be traced by LDC. To seek out the best management practices (BMPs) of pollutants in a watershed, and to overcome the limitation of LDC, we proposed to develop LDC based on a distributed hydrological model of SWAT for the water quality management in data scarce river basins. In this study, firstly, the distributed hydrological model of SWAT was established with the scarce-hydrological data. Then, the long-term daily flows were generated with the established SWAT model and rainfall data from the adjacent weather station. Flow duration curves (FDC) was then developed with the aid of generated daily flows by SWAT model. Considering the goal of water quality management, LDC curves of different pollutants can be obtained based on the FDC. With the monitored water quality data and the LDC curves, the water quality problems caused by the point or non-point source pollutants in different seasons can be ascertained. Finally, the distributed hydrological model of SWAT was employed again to tracing the spatial distribution and the origination of the pollutants of coming from what kind of agricultural practices and/or other human activities. A case study was conducted in the Jian-jiang river, a tributary of Yangtze river, of Duyun city, Guizhou province. Results indicate that this kind of method can realize the water quality management based on TMDL and find out the suitable BMPs for reducing pollutant in a watershed.

75 FR 2452 - Approval and Promulgation of Air Quality Implementation Plans; Delaware; Reasonable Further...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-15

... Lightering Operations. Since there will be no new VOC controls for point sources, non-point source sector... equivalent to 1.52 x 1.74 = 2.64 tpd NO X reduction shortfall. Delaware has implemented numerous controls... achieved ``as expeditious as practicable.'' Control measures under RACT constitute a major group of RACM...

Spatial Variations In The Fate And Transport Of Metals In A Mining-Influenced Stream, North Fork Clear Creek, Colorado

EPA Science Inventory

North Fork Clear Creek (NFCC) receives acid-mine drainage (AMD) from multiple abandoned mines in the Clear Creek Watershed. Point sources of AMD originate In the Black Hawk/Central City region of the stream. Water chemistry also is influenced by several non-point sources of AMD,...

Wind-tunnel Modelling of Dispersion from a Scalar Area Source in Urban-Like Roughness

NASA Astrophysics Data System (ADS)

Pascheke, Frauke; Barlow, Janet F.; Robins, Alan

2008-01-01

A wind-tunnel study was conducted to investigate ventilation of scalars from urban-like geometries at neighbourhood scale by exploring two different geometries a uniform height roughness and a non-uniform height roughness, both with an equal plan and frontal density of λ p = λ f = 25%. In both configurations a sub-unit of the idealized urban surface was coated with a thin layer of naphthalene to represent area sources. The naphthalene sublimation method was used to measure directly total area-averaged transport of scalars out of the complex geometries. At the same time, naphthalene vapour concentrations controlled by the turbulent fluxes were detected using a fast Flame Ionisation Detection (FID) technique. This paper describes the novel use of a naphthalene coated surface as an area source in dispersion studies. Particular emphasis was also given to testing whether the concentration measurements were independent of Reynolds number. For low wind speeds, transfer from the naphthalene surface is determined by a combination of forced and natural convection. Compared with a propane point source release, a 25% higher free stream velocity was needed for the naphthalene area source to yield Reynolds-number-independent concentration fields. Ventilation transfer coefficients w T / U derived from the naphthalene sublimation method showed that, whilst there was enhanced vertical momentum exchange due to obstacle height variability, advection was reduced and dispersion from the source area was not enhanced. Thus, the height variability of a canopy is an important parameter when generalising urban dispersion. Fine resolution concentration measurements in the canopy showed the effect of height variability on dispersion at street scale. Rapid vertical transport in the wake of individual high-rise obstacles was found to generate elevated point-like sources. A Gaussian plume model was used to analyse differences in the downstream plumes. Intensified lateral and vertical plume spread and plume dilution with height was found for the non-uniform height roughness.

IKT 16: the first X-ray confirmed composite SNR in the SMC

NASA Astrophysics Data System (ADS)

Maitra, C.; Ballet, J.; Filipović, M. D.; Haberl, F.; Tiengo, A.; Grieve, K.; Roper, Q.

2015-12-01

Aims: IKT 16 is an X-ray and radio-faint supernova remnant (SNR) in the Small Magellanic Cloud (SMC). A detailed X-ray study of this SNR with XMM-Newton confirmed the presence of a hard X-ray source near its centre, indicating the detection of the first composite SNR in the SMC. With a dedicated Chandra observation we aim to resolve the point source and confirm its nature. We also acquire new ATCA observations of the source at 2.1 GHz with improved flux density estimates and resolution. Methods: We perform detailed spatial and spectral analysis of the source. With the highest resolution X-ray and radio image of the centre of the SNR available today, we resolve the source and confirm its pulsar wind nebula (PWN) nature. Further, we constrain the geometrical parameters of the PWN and perform spectral analysis for the point source and the PWN separately. We also test for the radial variations of the PWN spectrum and its possible east west asymmetry. Results: The X-ray source at the centre of IKT 16 can be resolved into a symmetrical elongated feature centring a point source, the putative pulsar. Spatial modelling indicates an extent of 5.2'' of the feature with its axis inclined at 82° east from north, aligned with a larger radio feature consisting of two lobes almost symmetrical about the X-ray source. The picture is consistent with a PWN which has not yet collided with the reverse shock. The point source is about three times brighter than the PWN and has a hard spectrum of spectral index 1.1 compared to a value 2.2 for the PWN. This points to the presence of a pulsar dominated by non-thermal emission. The expected Ė is ~1037 erg s-1 and spin period <100 ms. However, the presence of a compact nebula unresolved by Chandra at the distance of the SMC cannot completely be ruled out. The reduced images (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/584/A41

X-ray Point Source Populations in Spiral and Elliptical Galaxies

NASA Astrophysics Data System (ADS)

Colbert, E.; Heckman, T.; Weaver, K.; Strickland, D.

2002-01-01

The hard-X-ray luminosity of non-active galaxies has been known to be fairly well correlated with the total blue luminosity since the days of the Einstein satellite. However, the origin of this hard component was not well understood. Some possibilities that were considered included X-ray binaries, extended upscattered far-infrared light via the inverse-Compton process, extended hot 107 K gas (especially in ellipitical galaxies), or even an active nucleus. Chandra images of normal, elliptical and starburst galaxies now show that a significant amount of the total hard X-ray emission comes from individual point sources. We present here spatial and spectral analyses of the point sources in a small sample of Chandra obervations of starburst galaxies, and compare with Chandra point source analyses from comparison galaxies (elliptical, Seyfert and normal galaxies). We discuss possible relationships between the number and total hard luminosity of the X-ray point sources and various measures of the galaxy star formation rate, and discuss possible options for the numerous compact sources that are observed.

Common Pitfalls in F77 Code Conversion

DTIC Science & Technology

2003-02-01

implementation versus another are the source of these errors rather than typography . It is well to use the practice of commenting-out original source file lines...identifier), every I in the format field must be replaced with f followed by an appropriate floating point format designator . Floating point numeric...helps even more. Finally, libraries are a major source of non-portablility[sic], with graphics libraries one of the chief culprits. We in Fusion

INCORPORATION OF DNA BARCODES INTO ASSESSMENTS OF THE BIOLOGICAL INTEGRITY OF AQUATIC ECOSYSTEMS: PRECISION, ACCURACY AND COST

EPA Science Inventory

Historically, water quality assessments in the United States primarily focused on water chemistry assays at or near discharge sources. As it has become clear that waters also can be highly impaired from dispersed (i.e., non-point source) chemicals and non-chemical impacts, direc...

Field demonstration of foam injection to confine a chlorinated solvent source zone.

PubMed

Portois, Clément; Essouayed, Elyess; Annable, Michael D; Guiserix, Nathalie; Joubert, Antoine; Atteia, Olivier

2018-05-01

A novel approach using foam to manage hazardous waste was successfully demonstrated under active site conditions. The purpose of the foam was to divert groundwater flow, that would normally enter the source zone area, to reduce dissolved contaminant release to the aquifer. During the demonstration, foam was pre generated and directly injected surrounding the chlorinated solvent source zone. Despite the constraints related to the industrial activities and non-optimal position of the injection points, the applicability and effectiveness of the approach have been highlighted using multiple metrics. A combination of measurements and modelling allowed definition of the foam extent surrounding each injection point, and this appears to be the critical metric to define the success of the foam injection approach. Information on the transport of chlorinated solvents in groundwater showed a decrease of contaminant flux by a factor of 4.4 downstream of the confined area. The effective permeability reduction was maintained over a period of three months. The successful containment provides evidence for consideration of the use of foam to improve traditional flushing techniques, by increasing the targeting of contaminants by remedial agents. Copyright © 2018 Elsevier B.V. All rights reserved.

Response of non-point source pollutant loads to climate change in the Shitoukoumen reservoir catchment.

PubMed

Zhang, Lei; Lu, Wenxi; An, Yonglei; Li, Di; Gong, Lei

2012-01-01

The impacts of climate change on streamflow and non-point source pollutant loads in the Shitoukoumen reservoir catchment are predicted by combining a general circulation model (HadCM3) with the Soil and Water Assessment Tool (SWAT) hydrological model. A statistical downscaling model was used to generate future local scenarios of meteorological variables such as temperature and precipitation. Then, the downscaled meteorological variables were used as input to the SWAT hydrological model calibrated and validated with observations, and the corresponding changes of future streamflow and non-point source pollutant loads in Shitoukoumen reservoir catchment were simulated and analyzed. Results show that daily temperature increases in three future periods (2010-2039, 2040-2069, and 2070-2099) relative to a baseline of 1961-1990, and the rate of increase is 0.63°C per decade. Annual precipitation also shows an apparent increase of 11 mm per decade. The calibration and validation results showed that the SWAT model was able to simulate well the streamflow and non-point source pollutant loads, with a coefficient of determination of 0.7 and a Nash-Sutcliffe efficiency of about 0.7 for both the calibration and validation periods. The future climate change has a significant impact on streamflow and non-point source pollutant loads. The annual streamflow shows a fluctuating upward trend from 2010 to 2099, with an increase rate of 1.1 m(3) s(-1) per decade, and a significant upward trend in summer, with an increase rate of 1.32 m(3) s(-1) per decade. The increase in summer contributes the most to the increase of annual load compared with other seasons. The annual NH (4) (+) -N load into Shitoukoumen reservoir shows a significant downward trend with a decrease rate of 40.6 t per decade. The annual TP load shows an insignificant increasing trend, and its change rate is 3.77 t per decade. The results of this analysis provide a scientific basis for effective support of decision makers and strategies of adaptation to climate change.

Increased nutrient concentrations in Lake Erie tributaries influenced by greenhouse agriculture.

PubMed

Maguire, Timothy J; Wellen, Christopher; Stammler, Katie L; Mundle, Scott O C

2018-08-15

Greenhouse production of vegetables is a growing global trade. While greenhouses are typically captured under regulations aimed at farmland, they may also function as a point source of effluent. In this study, the cumulative impacts greenhouse effluents have on riverine macronutrient and trace metal concentrations were examined. Water samples were collected Bi-weekly for five years from 14 rivers in agriculturally dominated watersheds in southwestern Ontario. Nine of the watersheds contained greenhouses with their boundaries. Greenhouse influenced rivers had significantly higher concentrations of macronutrients (nitrogen, phosphorus, and potassium) and trace metals (copper, molybdenum, and zinc). Concentrations within greenhouse influenced rivers appeared to decrease over the 5-year study while concentrations within non-greenhouse influenced river remained constant. The different temporal pattern between river types was attributed to increased precipitation during the study period. Increases in precipitation diluted concentrations in greenhouse influenced rivers; however, non-influenced river runoff proportionally increased nutrient mobility and flow, stabilizing the observed concentrations of non-point sources. Understanding the dynamic nature of environmental releases of point and non-point sources of nutrients and trace metals in mixed agricultural systems using riverine water chemistry is complicated by changes in climatic conditions, highlighting the need for long-term monitoring of nutrients, river flows and weather data in assessing these agricultural sectors. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Non-Point Source Pollutant Load Variation in Rapid Urbanization Areas by Remote Sensing, Gis and the L-THIA Model: A Case in Bao'an District, Shenzhen, China.

PubMed

Li, Tianhong; Bai, Fengjiao; Han, Peng; Zhang, Yuanyan

2016-11-01

Urban sprawl is a major driving force that alters local and regional hydrology and increases non-point source pollution. Using the Bao'an District in Shenzhen, China, a typical rapid urbanization area, as the study area and land-use change maps from 1988 to 2014 that were obtained by remote sensing, the contributions of different land-use types to NPS pollutant production were assessed with a localized long-term hydrologic impact assessment (L-THIA) model. The results show that the non-point source pollution load changed significantly both in terms of magnitude and spatial distribution. The loads of chemical oxygen demand, total suspended substances, total nitrogen and total phosphorus were affected by the interactions between event mean concentration and the magnitude of changes in land-use acreages and the spatial distribution. From 1988 to 2014, the loads of chemical oxygen demand, suspended substances and total phosphorus showed clearly increasing trends with rates of 132.48 %, 32.52 % and 38.76 %, respectively, while the load of total nitrogen decreased by 71.52 %. The immigrant population ratio was selected as an indicator to represent the level of rapid urbanization and industrialization in the study area, and a comparison analysis of the indicator with the four non-point source loads demonstrated that the chemical oxygen demand, total phosphorus and total nitrogen loads are linearly related to the immigrant population ratio. The results provide useful information for environmental improvement and city management in the study area.

Non-Point Source Pollutant Load Variation in Rapid Urbanization Areas by Remote Sensing, Gis and the L-THIA Model: A Case in Bao'an District, Shenzhen, China

NASA Astrophysics Data System (ADS)

Li, Tianhong; Bai, Fengjiao; Han, Peng; Zhang, Yuanyan

2016-11-01

Urban sprawl is a major driving force that alters local and regional hydrology and increases non-point source pollution. Using the Bao'an District in Shenzhen, China, a typical rapid urbanization area, as the study area and land-use change maps from 1988 to 2014 that were obtained by remote sensing, the contributions of different land-use types to NPS pollutant production were assessed with a localized long-term hydrologic impact assessment (L-THIA) model. The results show that the non-point source pollution load changed significantly both in terms of magnitude and spatial distribution. The loads of chemical oxygen demand, total suspended substances, total nitrogen and total phosphorus were affected by the interactions between event mean concentration and the magnitude of changes in land-use acreages and the spatial distribution. From 1988 to 2014, the loads of chemical oxygen demand, suspended substances and total phosphorus showed clearly increasing trends with rates of 132.48 %, 32.52 % and 38.76 %, respectively, while the load of total nitrogen decreased by 71.52 %. The immigrant population ratio was selected as an indicator to represent the level of rapid urbanization and industrialization in the study area, and a comparison analysis of the indicator with the four non-point source loads demonstrated that the chemical oxygen demand, total phosphorus and total nitrogen loads are linearly related to the immigrant population ratio. The results provide useful information for environmental improvement and city management in the study area.

A Comparative Analysis of Vibrio cholerae Contamination in Point-of-Drinking and Source Water in a Low-Income Urban Community, Bangladesh.

PubMed

Ferdous, Jannatul; Sultana, Rebeca; Rashid, Ridwan B; Tasnimuzzaman, Md; Nordland, Andreas; Begum, Anowara; Jensen, Peter K M

2018-01-01

Bangladesh is a cholera endemic country with a population at high risk of cholera. Toxigenic and non-toxigenic Vibrio cholerae ( V. cholerae ) can cause cholera and cholera-like diarrheal illness and outbreaks. Drinking water is one of the primary routes of cholera transmission in Bangladesh. The aim of this study was to conduct a comparative assessment of the presence of V. cholerae between point-of-drinking water and source water, and to investigate the variability of virulence profile using molecular methods of a densely populated low-income settlement of Dhaka, Bangladesh. Water samples were collected and tested for V. cholerae from "point-of-drinking" and "source" in 477 study households in routine visits at 6 week intervals over a period of 14 months. We studied the virulence profiles of V. cholerae positive water samples using 22 different virulence gene markers present in toxigenic O1/O139 and non-O1/O139 V. cholerae using polymerase chain reaction (PCR). A total of 1,463 water samples were collected, with 1,082 samples from point-of-drinking water in 388 households and 381 samples from 66 water sources. V. cholerae was detected in 10% of point-of-drinking water samples and in 9% of source water samples. Twenty-three percent of households and 38% of the sources were positive for V. cholerae in at least one visit. Samples collected from point-of-drinking and linked sources in a 7 day interval showed significantly higher odds ( P < 0.05) of V. cholerae presence in point-of-drinking compared to source [OR = 17.24 (95% CI = 7.14-42.89)] water. Based on the 7 day interval data, 53% (17/32) of source water samples were negative for V. cholerae while linked point-of-drinking water samples were positive. There were significantly higher odds ( p < 0.05) of the presence of V. cholerae O1 [OR = 9.13 (95% CI = 2.85-29.26)] and V. cholerae O139 [OR = 4.73 (95% CI = 1.19-18.79)] in source water samples than in point-of-drinking water samples. Contamination of water at the point-of-drinking is less likely to depend on the contamination at the water source. Hygiene education interventions and programs should focus and emphasize on water at the point-of-drinking, including repeated cleaning of drinking vessels, which is of paramount importance in preventing cholera.

Analyzing Variability in Landscape Nutrient Loading Using Spatially-Explicit Maps in the Great Lakes Basin

NASA Astrophysics Data System (ADS)

Hamlin, Q. F.; Kendall, A. D.; Martin, S. L.; Whitenack, H. D.; Roush, J. A.; Hannah, B. A.; Hyndman, D. W.

2017-12-01

Excessive loading of nitrogen and phosphorous to the landscape has caused biologically and economically damaging eutrophication and harmful algal blooms in the Great Lakes Basin (GLB) and across the world. We mapped source-specific loads of nitrogen and phosphorous to the landscape using broadly available data across the GLB. SENSMap (Spatially Explicit Nutrient Source Map) is a 30m resolution snapshot of nutrient loads ca. 2010. We use these maps to study variable nutrient loading and provide this information to watershed managers through NOAA's GLB Tipping Points Planner. SENSMap individually maps nutrient point sources and six non-point sources: 1) atmospheric deposition, 2) septic tanks, 3) non-agricultural chemical fertilizer, 4) agricultural chemical fertilizer, 5) manure, and 6) nitrogen fixation from legumes. To model source-specific loads at high resolution, SENSMap synthesizes a wide range of remotely sensed, surveyed, and tabular data. Using these spatially explicit nutrient loading maps, we can better calibrate local land use-based water quality models and provide insight to watershed managers on how to focus nutrient reduction strategies. Here we examine differences in dominant nutrient sources across the GLB, and how those sources vary by land use. SENSMap's high resolution, source-specific approach offers a different lens to understand nutrient loading than traditional semi-distributed or land use based models.

On the assessment of spatial resolution of PET systems with iterative image reconstruction

NASA Astrophysics Data System (ADS)

Gong, Kuang; Cherry, Simon R.; Qi, Jinyi

2016-03-01

Spatial resolution is an important metric for performance characterization in PET systems. Measuring spatial resolution is straightforward with a linear reconstruction algorithm, such as filtered backprojection, and can be performed by reconstructing a point source scan and calculating the full-width-at-half-maximum (FWHM) along the principal directions. With the widespread adoption of iterative reconstruction methods, it is desirable to quantify the spatial resolution using an iterative reconstruction algorithm. However, the task can be difficult because the reconstruction algorithms are nonlinear and the non-negativity constraint can artificially enhance the apparent spatial resolution if a point source image is reconstructed without any background. Thus, it was recommended that a background should be added to the point source data before reconstruction for resolution measurement. However, there has been no detailed study on the effect of the point source contrast on the measured spatial resolution. Here we use point source scans from a preclinical PET scanner to investigate the relationship between measured spatial resolution and the point source contrast. We also evaluate whether the reconstruction of an isolated point source is predictive of the ability of the system to resolve two adjacent point sources. Our results indicate that when the point source contrast is below a certain threshold, the measured FWHM remains stable. Once the contrast is above the threshold, the measured FWHM monotonically decreases with increasing point source contrast. In addition, the measured FWHM also monotonically decreases with iteration number for maximum likelihood estimate. Therefore, when measuring system resolution with an iterative reconstruction algorithm, we recommend using a low-contrast point source and a fixed number of iterations.

Disinfection By-Product Formation and Mitigation Strategies in Point-of-Use Chlorination with Sodium Dichloroisocyanurate in Tanzania

PubMed Central

Lantagne, Daniele S.; Cardinali, Fred; Blount, Ben C.

2010-01-01

Almost a billion persons lack access to improved drinking water, and diarrheal diseases cause an estimated 1.87 million deaths per year. Sodium dichloroisocyanurate (NaDCC) tablets are widely recommended for household water treatment to reduce diarrhea. Because NaDCC is directly added to untreated water sources, concerns have been raised about the potential health impact of disinfection by-products. This study investigated trihalomethane (THM) production in water from six sources used for drinking (0.6–888.5 nephelometric turbidity units) near Arusha, Tanzania. No sample collected at 1, 8, and 24 hours after NaDCC addition exceeded the World Health Organization guideline values for either individual or total THMs. Ceramic filtration, sand filtration, cloth filtration, and settling and decanting were not effective mitigation strategies to reduce THM formation. Chlorine residual and THM formation were not significantly different in NaDCC and sodium hypochlorite treatment. Household chlorination of turbid and non-turbid waters did not create THM concentrations that exceeded health risk guidelines. PMID:20595492

Estimation of Enterococci Input from Bathers and Animals on A Recreational Beach Using Camera Images

PubMed Central

D, Wang John; M, Solo-Gabriele Helena; M, Abdelzaher Amir; E, Fleming Lora

2010-01-01

Enterococci, are used nationwide as a water quality indicator of marine recreational beaches. Prior research has demonstrated that enterococci inputs to the study beach site (located in Miami, FL) are dominated by non-point sources (including humans and animals). We have estimated their respective source functions by developing a counting methodology for individuals to better understand their non-point source load impacts. The method utilizes camera images of the beach taken at regular time intervals to determine the number of people and animal visitors. The developed method translates raw image counts for weekdays and weekend days into daily and monthly visitation rates. Enterococci source functions were computed from the observed number of unique individuals for average days of each month of the year, and from average load contributions for humans and for animals. Results indicate that dogs represent the larger source of enterococci relative to humans and birds. PMID:20381094

The Treatment Train approach to reducing non-point source pollution from agriculture

NASA Astrophysics Data System (ADS)

Barber, N.; Reaney, S. M.; Barker, P. A.; Benskin, C.; Burke, S.; Cleasby, W.; Haygarth, P.; Jonczyk, J. C.; Owen, G. J.; Snell, M. A.; Surridge, B.; Quinn, P. F.

2016-12-01

An experimental approach has been applied to an agricultural catchment in NW England, where non-point pollution adversely affects freshwater ecology. The aim of the work (as part of the River Eden Demonstration Test Catchment project) is to develop techniques to manage agricultural runoff whilst maintaining food production. The approach used is the Treatment Train (TT), which applies multiple connected mitigation options that control nutrient and fine sediment pollution at source, and address polluted runoff pathways at increasing spatial scale. The principal agricultural practices in the study sub-catchment (1.5 km2) are dairy and stock production. Farm yards can act as significant pollution sources by housing large numbers of animals; these areas are addressed initially with infrastructure improvements e.g. clean/dirty water separation and upgraded waste storage. In-stream high resolution monitoring of hydrology and water quality parameters showed high-discharge events to account for the majority of pollutant exports ( 80% total phosphorus; 95% fine sediment), and primary transfer routes to be surface and shallow sub-surface flow pathways, including drains. To manage these pathways and reduce hydrological connectivity, a series of mitigation features were constructed to intercept and temporarily store runoff. Farm tracks, field drains, first order ditches and overland flow pathways were all targeted. The efficacy of the mitigation features has been monitored at event and annual scale, using inflow-outflow sampling and sediment/nutrient accumulation measurements, respectively. Data presented here show varied but positive results in terms of reducing acute and chronic sediment and nutrient losses. An aerial fly-through of the catchment is used to demonstrate how the TT has been applied to a fully-functioning agricultural landscape. The elevated perspective provides a better understanding of the spatial arrangement of mitigation features, and how they can be implemented without impacting on the farm's primary function. The TT has the potential to yield benefits beyond those associated with water quality. Increasing catchment resilience through the use of landscape interventions can provide multiple benefits by mitigating for floods and droughts and creating ecological habitat.

Perspex machine: V. Compilation of C programs

NASA Astrophysics Data System (ADS)

Spanner, Matthew P.; Anderson, James A. D. W.

2006-01-01

The perspex machine arose from the unification of the Turing machine with projective geometry. The original, constructive proof used four special, perspective transformations to implement the Turing machine in projective geometry. These four transformations are now generalised and applied in a compiler, implemented in Pop11, that converts a subset of the C programming language into perspexes. This is interesting both from a geometrical and a computational point of view. Geometrically, it is interesting that program source can be converted automatically to a sequence of perspective transformations and conditional jumps, though we find that the product of homogeneous transformations with normalisation can be non-associative. Computationally, it is interesting that program source can be compiled for a Reduced Instruction Set Computer (RISC), the perspex machine, that is a Single Instruction, Zero Exception (SIZE) computer.

Developement of watershed and reference loads for a TMDL in Charleston Harbor System, SC.

Treesearch

Silong Lu; Devenra Amatya; Jamie Miller

2005-01-01

It is essential to determine point and non-point source loads and their distribution for development of a dissolved oxygen (DO) Total Maximum Daily Load (TMDL). A series of models were developed to assess sources of oxygen-demand loadings in Charleston Harbor, South Carolina. These oxygen-demand loadings included nutrients and BOD. Stream flow and nutrient...

Controllability of semi-infinite rod heating by a point source

NASA Astrophysics Data System (ADS)

Khurshudyan, A.

2018-04-01

The possibility of control over heating of a semi-infinite thin rod by a point source concentrated at an inner point of the rod, is studied. Quadratic and piecewise constant solutions of the problem are derived, and the possibilities of solving appropriate problems of optimal control are indicated. Determining of the parameters of the piecewise constant solution is reduced to a problem of nonlinear programming. Numerical examples are considered.

40 CFR 430.125 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... GUIDELINES AND STANDARDS (CONTINUED) THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter... where filter and non-woven papers are produced from purchased pulp] Pollutant or pollutant property Kg...

40 CFR 430.125 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... GUIDELINES AND STANDARDS (CONTINUED) THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter... where filter and non-woven papers are produced from purchased pulp] Pollutant or pollutant property Kg...

40 CFR 430.125 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... GUIDELINES AND STANDARDS (CONTINUED) THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter... where filter and non-woven papers are produced from purchased pulp] Pollutant or pollutant property Kg...

A Comparative Analysis of Vibrio cholerae Contamination in Point-of-Drinking and Source Water in a Low-Income Urban Community, Bangladesh

PubMed Central

Ferdous, Jannatul; Sultana, Rebeca; Rashid, Ridwan B.; Tasnimuzzaman, Md.; Nordland, Andreas; Begum, Anowara; Jensen, Peter K. M.

2018-01-01

Bangladesh is a cholera endemic country with a population at high risk of cholera. Toxigenic and non-toxigenic Vibrio cholerae (V. cholerae) can cause cholera and cholera-like diarrheal illness and outbreaks. Drinking water is one of the primary routes of cholera transmission in Bangladesh. The aim of this study was to conduct a comparative assessment of the presence of V. cholerae between point-of-drinking water and source water, and to investigate the variability of virulence profile using molecular methods of a densely populated low-income settlement of Dhaka, Bangladesh. Water samples were collected and tested for V. cholerae from “point-of-drinking” and “source” in 477 study households in routine visits at 6 week intervals over a period of 14 months. We studied the virulence profiles of V. cholerae positive water samples using 22 different virulence gene markers present in toxigenic O1/O139 and non-O1/O139 V. cholerae using polymerase chain reaction (PCR). A total of 1,463 water samples were collected, with 1,082 samples from point-of-drinking water in 388 households and 381 samples from 66 water sources. V. cholerae was detected in 10% of point-of-drinking water samples and in 9% of source water samples. Twenty-three percent of households and 38% of the sources were positive for V. cholerae in at least one visit. Samples collected from point-of-drinking and linked sources in a 7 day interval showed significantly higher odds (P < 0.05) of V. cholerae presence in point-of-drinking compared to source [OR = 17.24 (95% CI = 7.14–42.89)] water. Based on the 7 day interval data, 53% (17/32) of source water samples were negative for V. cholerae while linked point-of-drinking water samples were positive. There were significantly higher odds (p < 0.05) of the presence of V. cholerae O1 [OR = 9.13 (95% CI = 2.85–29.26)] and V. cholerae O139 [OR = 4.73 (95% CI = 1.19–18.79)] in source water samples than in point-of-drinking water samples. Contamination of water at the point-of-drinking is less likely to depend on the contamination at the water source. Hygiene education interventions and programs should focus and emphasize on water at the point-of-drinking, including repeated cleaning of drinking vessels, which is of paramount importance in preventing cholera. PMID:29616005

Water quality modeling using geographic information system (GIS) data

NASA Technical Reports Server (NTRS)

Engel, Bernard A

1992-01-01

Protection of the environment and natural resources at the Kennedy Space Center (KSC) is of great concern. The potential for surface and ground water quality problems resulting from non-point sources of pollution was examined using models. Since spatial variation of parameters required was important, geographic information systems (GIS) and their data were used. The potential for groundwater contamination was examined using the SEEPAGE (System for Early Evaluation of the Pollution Potential of Agricultural Groundwater Environments) model. A watershed near the VAB was selected to examine potential for surface water pollution and erosion using the AGNPS (Agricultural Non-Point Source Pollution) model.

The estimation of the load of non-point source nitrogen and phosphorus based on observation experiments and export coefficient method in Three Gorges Reservoir Area

NASA Astrophysics Data System (ADS)

Tong, X. X.; Hu, B.; Xu, W. S.; Liu, J. G.; Zhang, P. C.

2017-12-01

In this paper, Three Gorges Reservoir Area (TGRA) was chosen to be the study area, the export coefficients of different land-use type were calculated through the observation experiments and literature consultation, and then the load of non-point source (NPS) nitrogen and phosphorus of different pollution sources such as farmland pollution sources, decentralized livestock and poultry breeding pollution sources and domestic pollution sources were estimated. The results show as follows: the pollution load of dry land is the main source of farmland pollution. The order of total nitrogen load of different pollution sources from high to low is livestock breeding pollution, domestic pollution, land use pollution, while the order of phosphorus load of different pollution sources from high to low is land use pollution, livestock breeding pollution, domestic pollution, Therefore, reasonable farmland management, effective control methods of dry land fertilization and sewage discharge of livestock breeding are the keys to the prevention and control of NPS nitrogen and phosphorus in TGRA.

Monitoring and Analysis of Nonpoint Source Pollution - Case study on terraced paddy fields in an agricultural watershed

NASA Astrophysics Data System (ADS)

Chen, Shih-Kai; Jang, Cheng-Shin; Yeh, Chun-Lin

2013-04-01

The intensive use of chemical fertilizer has negatively impacted environments in recent decades, mainly through water pollution by nitrogen (N) and phosphate (P) originating from agricultural activities. As a main crop with the largest cultivation area about 0.25 million ha per year in Taiwan, rice paddies account for a significant share of fertilizer consumption among agriculture crops. This study evaluated the fertilization of paddy fields impacting return flow water quality in an agricultural watershed located at Hsinchu County, northern Taiwan. Water quality monitoring continued for two crop-periods in 2012, around subject to different water bodies, including the irrigation water, drainage water, and shallow groundwater. The results indicated that obviously increasing of ammonium-N, nitrate-N and TP concentrations in the surface drainage water were observed immediately following three times of fertilizer applications (including basal, tillering, and panicle fertilizer application), but reduced to relatively low concentrations after 7-10 days after each fertilizer application. Groundwater quality monitoring showed that the observation wells with the more shallow water depth, the more significant variation of concentrations of ammonium-N, nitrate-N and TP could be observed, which means that the contamination potential of nutrient of groundwater is related not only to the impermeable plow sole layer but also to the length of percolation route in this area. The study also showed that the potential pollution load of nutrient could be further reduced by well drainage water control and rational fertilizer management, such as deep-water irrigation, reuse of return flow, the rational application of fertilizers, and the SRI (The System of Rice Intensification) method. The results of this study can provide as an evaluation basis to formulate effective measures for agricultural non-point source pollution control and the reuse of agricultural return flow. Keywords:Chemical fertilizer, Nitrogen, Phosphorus, Paddy field, Non-point source pollution.

Probabilistic Analysis of Earthquake-Led Water Contamination: A Case of Sichuan, China

NASA Astrophysics Data System (ADS)

Yang, Yan; Li, Lin; Benjamin Zhan, F.; Zhuang, Yanhua

2016-06-01

The objective of this paper is to evaluate seismic-led point source and non-point source water pollution, under the seismic hazard of 10 % probability of exceedance in 50 years, and with the minimum value of the water quality standard in Sichuan, China. The soil conservation service curve number method of calculating the runoff depth in the single rainfall event combined with the seismic damage index were applied to estimate the potential degree of non-point source water pollution. To estimate the potential impact of point source water pollution, a comprehensive water pollution evaluation framework is constructed using a combination of Water Quality Index and Seismic Damage Index methods. The four key findings of this paper are: (1) The water catchment that has the highest factory concentration does not have the highest risk of non-point source water contamination induced by the outbreak of potential earthquake. (2) The water catchment that has the highest numbers of cumulative water pollutants types are typically located in the south western parts of Sichuan where the main river basins in the regions flow through. (3) The most common pollutants in sample factories studied is COD and NH3-N which are found in all catchments. The least common pollutant is pathogen—found present in W1 catchment which has the best rating in the water quality index. (4) Using water quality index as a standardization parameter, parallel comparisons is made among the 16 water catchments. Only catchment W1 reaches level II water quality status which has the rating of moderately polluted in events of earthquake induced water contamination. All other areas suffer from severe water contamination with multiple pollution sources. The results from the data model are significant to urban planning commissions and businesses to strategically choose their factory locations in order to minimize potential hazardous impact during the outbreak of earthquake.

Non-uniformity calibration for MWIR polarization imagery obtained with integrated microgrid polarimeters

NASA Astrophysics Data System (ADS)

Liu, Hai-Zheng; Shi, Ze-Lin; Feng, Bin; Hui, Bin; Zhao, Yao-Hong

2016-03-01

Integrating microgrid polarimeters on focal plane array (FPA) of an infrared detector causes non-uniformity of polarization response. In order to reduce the effect of polarization non-uniformity, this paper constructs an experimental setup for capturing raw flat-field images and proposes a procedure for acquiring non-uniform calibration (NUC) matrix and calibrating raw polarization images. The proposed procedure takes the incident radiation as a polarization vector and offers a calibration matrix for each pixel. Both our matrix calibration and two-point calibration are applied to our mid-wavelength infrared (MWIR) polarization imaging system with integrated microgrid polarimeters. Compared with two point calibration, our matrix calibration reduces non-uniformity by 30 40% under condition of flat-field data test with polarization. The ourdoor scene observation experiment indicates that our calibration can effectively reduce polarization non-uniformity and improve the image quality of our MWIR polarization imaging system.

[Estimation of urban non-point source pollution loading and its factor analysis in the Pearl River Delta].

PubMed

Liao, Yi-Shan; Zhuo, Mu-Ning; Li, Ding-Qiang; Guo, Tai-Long

2013-08-01

In the Pearl Delta region, urban rivers have been seriously polluted, and the input of non-point source pollution materials, such as chemical oxygen demand (COD), into rivers cannot be neglected. During 2009-2010, the water qualities at eight different catchments in the Fenjiang River of Foshan city were monitored, and the COD loads for eight rivulet sewages were calculated in respect of different rainfall conditions. Interesting results were concluded in our paper. The rainfall and landuse type played important roles in the COD loading, with greater influence of rainfall than landuse type. Consequently, a COD loading formula was constructed that was defined as a function of runoff and landuse type that were derived SCS model and land use map. Loading of COD could be evaluated and predicted with the constructed formula. The mean simulation accuracy for single rainfall event was 75.51%. Long-term simulation accuracy was better than that of single rainfall. In 2009, the estimated COD loading and its loading intensity were 8 053 t and 339 kg x (hm2 x a)(-1), and the industrial land was regarded as the main source of COD pollution area. The severe non-point source pollution such as COD in Fenjiang River must be paid more attention in the future.

Quality of internet-based decision aids for shoulder arthritis: what are patients reading?

PubMed

Somerson, Jeremy S; Bois, Aaron J; Jeng, Jeffrey; Bohsali, Kamal I; Hinchey, John W; Wirth, Michael A

2018-04-11

The objective of this study was to assess the source, quality, accuracy, and completeness of Internet-based information for shoulder arthritis. A web search was performed using three common Internet search engines and the top 50 sites from each search were analyzed. Information sources were categorized into academic, commercial, non-profit, and physician sites. Information quality was measured using the Health On the Net (HON) Foundation principles, content accuracy by counting factual errors and completeness using a custom template. After removal of duplicates and sites that did not provide an overview of shoulder arthritis, 49 websites remained for analysis. The majority of sites were from commercial (n = 16, 33%) and physician (n = 16, 33%) sources. An additional 12 sites (24%) were from an academic institution and five sites (10%) were from a non-profit organization. Commercial sites had the highest number of errors, with a five-fold likelihood of containing an error compared to an academic site. Non-profit sites had the highest HON scores, with an average of 9.6 points on a 16-point scale. The completeness score was highest for academic sites, with an average score of 19.2 ± 6.7 (maximum score of 49 points); other information sources had lower scores (commercial, 15.2 ± 2.9; non-profit, 18.7 ± 6.8; physician, 16.6 ± 6.3). Patient information on the Internet regarding shoulder arthritis is of mixed accuracy, quality, and completeness. Surgeons should actively direct patients to higher-quality Internet sources.

Comparison of the different approaches to generate holograms from data acquired with a Kinect sensor

NASA Astrophysics Data System (ADS)

Kang, Ji-Hoon; Leportier, Thibault; Ju, Byeong-Kwon; Song, Jin Dong; Lee, Kwang-Hoon; Park, Min-Chul

2017-05-01

Data of real scenes acquired in real-time with a Kinect sensor can be processed with different approaches to generate a hologram. 3D models can be generated from a point cloud or a mesh representation. The advantage of the point cloud approach is that computation process is well established since it involves only diffraction and propagation of point sources between parallel planes. On the other hand, the mesh representation enables to reduce the number of elements necessary to represent the object. Then, even though the computation time for the contribution of a single element increases compared to a simple point, the total computation time can be reduced significantly. However, the algorithm is more complex since propagation of elemental polygons between non-parallel planes should be implemented. Finally, since a depth map of the scene is acquired at the same time than the intensity image, a depth layer approach can also be adopted. This technique is appropriate for a fast computation since propagation of an optical wavefront from one plane to another can be handled efficiently with the fast Fourier transform. Fast computation with depth layer approach is convenient for real time applications, but point cloud method is more appropriate when high resolution is needed. In this study, since Kinect can be used to obtain both point cloud and depth map, we examine the different approaches that can be adopted for hologram computation and compare their performance.

Time-frequency approach to underdetermined blind source separation.

PubMed

Xie, Shengli; Yang, Liu; Yang, Jun-Mei; Zhou, Guoxu; Xiang, Yong

2012-02-01

This paper presents a new time-frequency (TF) underdetermined blind source separation approach based on Wigner-Ville distribution (WVD) and Khatri-Rao product to separate N non-stationary sources from M(M <; N) mixtures. First, an improved method is proposed for estimating the mixing matrix, where the negative value of the auto WVD of the sources is fully considered. Then after extracting all the auto-term TF points, the auto WVD value of the sources at every auto-term TF point can be found out exactly with the proposed approach no matter how many active sources there are as long as N ≤ 2M-1. Further discussion about the extraction of auto-term TF points is made and finally the numerical simulation results are presented to show the superiority of the proposed algorithm by comparing it with the existing ones.

Potential contribution of ecosystem services associated with altered management activities in the Wabash River watershed to sustainable water management in the Ohio River Basin

EPA Science Inventory

The Ohio River (OR) is an important river in North America. It has many different functions for use by humans and wildlife. Water quality of the OR main stem is 50% impaired. The impairment originates from point sources located on the shores of the OR, from non-point sources and ...

Assessment of Groundwater Susceptibility to Non-Point Source Contaminants Using Three-Dimensional Transient Indexes.

PubMed

Zhang, Yong; Weissmann, Gary S; Fogg, Graham E; Lu, Bingqing; Sun, HongGuang; Zheng, Chunmiao

2018-06-05

Groundwater susceptibility to non-point source contamination is typically quantified by stable indexes, while groundwater quality evolution (or deterioration globally) can be a long-term process that may last for decades and exhibit strong temporal variations. This study proposes a three-dimensional (3- d ), transient index map built upon physical models to characterize the complete temporal evolution of deep aquifer susceptibility. For illustration purposes, the previous travel time probability density (BTTPD) approach is extended to assess the 3- d deep groundwater susceptibility to non-point source contamination within a sequence stratigraphic framework observed in the Kings River fluvial fan (KRFF) aquifer. The BTTPD, which represents complete age distributions underlying a single groundwater sample in a regional-scale aquifer, is used as a quantitative, transient measure of aquifer susceptibility. The resultant 3- d imaging of susceptibility using the simulated BTTPDs in KRFF reveals the strong influence of regional-scale heterogeneity on susceptibility. The regional-scale incised-valley fill deposits increase the susceptibility of aquifers by enhancing rapid downward solute movement and displaying relatively narrow and young age distributions. In contrast, the regional-scale sequence-boundary paleosols within the open-fan deposits "protect" deep aquifers by slowing downward solute movement and displaying a relatively broad and old age distribution. Further comparison of the simulated susceptibility index maps to known contaminant distributions shows that these maps are generally consistent with the high concentration and quick evolution of 1,2-dibromo-3-chloropropane (DBCP) in groundwater around the incised-valley fill since the 1970s'. This application demonstrates that the BTTPDs can be used as quantitative and transient measures of deep aquifer susceptibility to non-point source contamination.

Non-domestic phosphorus release in rivers during low-flow: Mechanisms and implications for sources identification

NASA Astrophysics Data System (ADS)

Dupas, Rémi; Tittel, Jörg; Jordan, Phil; Musolff, Andreas; Rode, Michael

2018-05-01

A common assumption in phosphorus (P) load apportionment studies is that P loads in rivers consist of flow independent point source emissions (mainly from domestic and industrial origins) and flow dependent diffuse source emissions (mainly from agricultural origin). Hence, rivers dominated by point sources will exhibit highest P concentration during low-flow, when flow dilution capacity is minimal, whereas rivers dominated by diffuse sources will exhibit highest P concentration during high-flow, when land-to-river hydrological connectivity is maximal. Here, we show that Soluble Reactive P (SRP) concentrations in three forested catchments free of point sources exhibited seasonal maxima during the summer low-flow period, i.e. a pattern expected in point source dominated areas. A load apportionment model (LAM) is used to show how point sources contribution may have been overestimated in previous studies, because of a biogeochemical process mimicking a point source signal. Almost twenty-two years (March 1995-September 2016) of monthly monitoring data of SRP, dissolved iron (Fe) and nitrate-N (NO3) were used to investigate the underlying mechanisms: SRP and Fe exhibited similar seasonal patterns and opposite to that of NO3. We hypothesise that Fe oxyhydroxide reductive dissolution might be the cause of SRP release during the summer period, and that NO3 might act as a redox buffer, controlling the seasonality of SRP release. We conclude that LAMs may overestimate the contribution of P point sources, especially during the summer low-flow period, when eutrophication risk is maximal.

[Reducing nutrients loss by plastic film covering chemical fertilizers].

PubMed

Chen, Huo-jun; Wei, Ze-bin; Wu, Qi-tang; Zeng, Shu-cai

2010-03-01

With the low utilization rate of fertilizers by crop and the growing amount of fertilizer usage,the agricultural non-point source pollution in China is becoming more and more serious. The field experiments planting corns were conducted, in which the applied chemical fertilizers were recovered with plastic film to realize the separation of fertilizers from rain water. In the experiments, the influences of different fertilizing treatments on the growing and production of sweet corn were observed. The fertilizer utilization rate and the nutrient contents in surface run-off water with and without the film covering were also determined. Results showed that, with only 70% of the normal amount of fertilizers,the sweet corn could already get high yield under the experimental soil conditions. Soil analysis after corn crops showed that the amounts of available N, P and K in the soil increased obviously with the film-covering, and the decreasing order was: 100% fertilizers with film-covering > 70% fertilizers with film-covering > 100% fertilizers, 70% fertilizers > no fertilizer. The average utilization coefficients of fertilizers by the crop were 42%-87%, 0%-3%, 5%-15% respectively for N, P and K. It was higher with film-covering than that without covering, especially for the high fertilization treatment. Analysis of water samples collected for eight run-off events showed that, without film-covering, N, P and K average concentrations in the runoff waters with fertilizations were 27.72, 2.70 and 7.07 mg x L(-1), respectively. And they were reduced respectively by 39.54%, 28.05%, 43.74% with the film-covering. This can give significant benefits to the decrease of agricultural non-point source pollution and water eutrophication.

Developing a non-point source P loss indicator in R and its parameter uncertainty assessment using GLUE: a case study in northern China.

PubMed

Su, Jingjun; Du, Xinzhong; Li, Xuyong

2018-05-16

Uncertainty analysis is an important prerequisite for model application. However, the existing phosphorus (P) loss indexes or indicators were rarely evaluated. This study applied generalized likelihood uncertainty estimation (GLUE) method to assess the uncertainty of parameters and modeling outputs of a non-point source (NPS) P indicator constructed in R language. And the influences of subjective choices of likelihood formulation and acceptability threshold of GLUE on model outputs were also detected. The results indicated the following. (1) Parameters RegR 2 , RegSDR 2 , PlossDP fer , PlossDP man , DPDR, and DPR were highly sensitive to overall TP simulation and their value ranges could be reduced by GLUE. (2) Nash efficiency likelihood (L 1 ) seemed to present better ability in accentuating high likelihood value simulations than the exponential function (L 2 ) did. (3) The combined likelihood integrating the criteria of multiple outputs acted better than single likelihood in model uncertainty assessment in terms of reducing the uncertainty band widths and assuring the fitting goodness of whole model outputs. (4) A value of 0.55 appeared to be a modest choice of threshold value to balance the interests between high modeling efficiency and high bracketing efficiency. Results of this study could provide (1) an option to conduct NPS modeling under one single computer platform, (2) important references to the parameter setting for NPS model development in similar regions, (3) useful suggestions for the application of GLUE method in studies with different emphases according to research interests, and (4) important insights into the watershed P management in similar regions.

Niagara River Toxics Management Plan

EPA Pesticide Factsheets

This 2007 Progress Report of the Niagara River Toxics Management Plan (NRTMP) summarizes progress made by the four parties in dealing with the 18 “Priority Toxics” through reductions in point and non-point sources to the Niagara River.

Mortality rates of pathogen indicator microorganisms discharged from point and non-point sources in an urban area.

PubMed

Kim, Geonha; Hur, Jin

2010-01-01

This research measured the mortality rates of pathogen indicator microorganisms discharged from various point and non-point sources in an urban area. Water samples were collected from a domestic sewer, a combined sewer overflow, the effluent of a wastewater treatment plant, and an urban river. Mortality rates of indicator microorganisms in sediment of an urban river were also measured. Mortality rates of indicator microorganisms in domestic sewage, estimated by assuming first order kinetics at 20 degrees C were 0.197 day(-1), 0.234 day(-1), 0.258 day(-1) and 0.276 day(-1) for total coliform, fecal coliform, Escherichia coli, and fecal streptococci, respectively. Effects of temperature, sunlight irradiation and settlement on the mortality rate were measured. Results of this research can be used as input data for water quality modeling or can be used as design factors for treatment facilities.

Cortical Reorganisation during a 30-Week Tinnitus Treatment Program

PubMed Central

McMahon, Catherine M.; Ibrahim, Ronny K.; Mathur, Ankit

2016-01-01

Subjective tinnitus is characterised by the conscious perception of a phantom sound. Previous studies have shown that individuals with chronic tinnitus have disrupted sound-evoked cortical tonotopic maps, time-shifted evoked auditory responses, and altered oscillatory cortical activity. The main objectives of this study were to: (i) compare sound-evoked brain responses and cortical tonotopic maps in individuals with bilateral tinnitus and those without tinnitus; and (ii) investigate whether changes in these sound-evoked responses occur with amelioration of the tinnitus percept during a 30-week tinnitus treatment program. Magnetoencephalography (MEG) recordings of 12 bilateral tinnitus participants and 10 control normal-hearing subjects reporting no tinnitus were recorded at baseline, using 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz tones presented monaurally at 70 dBSPL through insert tube phones. For the tinnitus participants, MEG recordings were obtained at 5-, 10-, 20- and 30- week time points during tinnitus treatment. Results for the 500 Hz and 1000 Hz sources (where hearing thresholds were within normal limits for all participants) showed that the tinnitus participants had a significantly larger and more anteriorly located source strengths when compared to the non-tinnitus participants. During the 30-week tinnitus treatment, the participants’ 500 Hz and 1000 Hz source strengths remained higher than the non-tinnitus participants; however, the source locations shifted towards the direction recorded from the non-tinnitus control group. Further, in the left hemisphere, there was a time-shifted association between the trajectory of change of the individual’s objective (source strength and anterior-posterior source location) and subjective measures (using tinnitus reaction questionnaire, TRQ). The differences in source strength between the two groups suggest that individuals with tinnitus have enhanced central gain which is not significantly influenced by the tinnitus treatment, and may result from the hearing loss per se. On the other hand, the shifts in the tonotopic map towards the non-tinnitus participants’ source location suggests that the tinnitus treatment might reduce the disruptions in the map, presumably produced by the tinnitus percept directly or indirectly. Further, the similarity in the trajectory of change across the objective and subjective parameters after time-shifting the perceptual changes by 5 weeks suggests that during or following treatment, perceptual changes in the tinnitus percept may precede neurophysiological changes. Subgroup analyses conducted by magnitude of hearing loss suggest that there were no differences in the 500 Hz and 1000 Hz source strength amplitudes for the mild-moderate compared with the mild-severe hearing loss subgroup, although the mean source strength was consistently higher for the mild-severe subgroup. Further, the mild-severe subgroup had 500 Hz and 1000 Hz source locations located more anteriorly (i.e., more disrupted compared to the control group) compared to the mild-moderate group, although this was trending towards significance only for the 500Hz left hemisphere source. While the small numbers of participants within the subgroup analyses reduce the statistical power, this study suggests that those with greater magnitudes of hearing loss show greater cortical disruptions with tinnitus and that tinnitus treatment appears to reduce the tonotopic map disruptions but not the source strength (or central gain). PMID:26901425

Finding and Using Wasted Water to Restore Baldcypress - Water Tupelo Swamps and Freshwater Marshes and Protect Against Salt Water Intrusion: A Case Study of the Lake Pontchartrain Basin

NASA Astrophysics Data System (ADS)

Shaffer, G. P.; Lane, R.; Day, J. W.; Barrett, S.

2017-12-01

We developed a geographic information system (GIS) containing substantial point and non-point freshwater sources along the North Shore of Lake Pontchartrain, from Lake Maurepas to the Pearl River, which potentially could be directed at degraded wetlands. Thus far, we have concentrated on municipal wastewater treatment facilities, subdivisions treating their own sewage, non-point source drainage features, and potential Mississippi River diversion sites. Most analysis, processing, and mapping were conducted in Arc GIS v9.2. Five classes of source water ranging from <25,000 to >100,000 gallons per day were mapped. These were color and size coded and the level of detail in the GIS varies according to aerial coverage. That is, the overall image is in broad brush and increasing detail is automatically provided as the user increases magnification The sources were then prioritized by size and distance from a marsh or swamp. Because assimilation wetlands into marshes in coastal Louisiana attract the introduced rodent nutria (Myocaster coypus) swamps were weighted higher than marshes. The top five sources were all wastewater facilities located near swamps.

40 CFR 445.24 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards (NSPS). 445.24 Section 445.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LANDFILLS POINT SOURCE CATEGORY RCRA Subtitle D Non-Hazardous Waste Landfill § 445...

40 CFR 425.34 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false New source performance standards (NSPS). 425.34 Section 425.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome...

40 CFR 425.34 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards (NSPS). 425.34 Section 425.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome...

40 CFR 430.85 - New source performance standards (NSPS). [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false New source performance standards (NSPS). [Reserved] 430.85 Section 430.85 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Non-Wood Chemical...

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

Aartsen, M. G.; Abraham, K.; Ackermann, M.

Observation of a point source of astrophysical neutrinos would be a “smoking gun” signature of a cosmic-ray accelerator. While IceCube has recently discovered a diffuse flux of astrophysical neutrinos, no localized point source has been observed. Previous IceCube searches for point sources in the southern sky were restricted by either an energy threshold above a few hundred TeV or poor neutrino angular resolution. Here we present a search for southern sky point sources with greatly improved sensitivities to neutrinos with energies below 100 TeV. By selecting charged-current ν{sub μ} interacting inside the detector, we reduce the atmospheric background while retainingmore » efficiency for astrophysical neutrino-induced events reconstructed with sub-degree angular resolution. The new event sample covers three years of detector data and leads to a factor of 10 improvement in sensitivity to point sources emitting below 100 TeV in the southern sky. No statistically significant evidence of point sources was found, and upper limits are set on neutrino emission from individual sources. A posteriori analysis of the highest-energy (∼100 TeV) starting event in the sample found that this event alone represents a 2.8 σ deviation from the hypothesis that the data consists only of atmospheric background.« less

Automatic Classification of Trees from Laser Scanning Point Clouds

NASA Astrophysics Data System (ADS)

Sirmacek, B.; Lindenbergh, R.

2015-08-01

Development of laser scanning technologies has promoted tree monitoring studies to a new level, as the laser scanning point clouds enable accurate 3D measurements in a fast and environmental friendly manner. In this paper, we introduce a probability matrix computation based algorithm for automatically classifying laser scanning point clouds into 'tree' and 'non-tree' classes. Our method uses the 3D coordinates of the laser scanning points as input and generates a new point cloud which holds a label for each point indicating if it belongs to the 'tree' or 'non-tree' class. To do so, a grid surface is assigned to the lowest height level of the point cloud. The grids are filled with probability values which are calculated by checking the point density above the grid. Since the tree trunk locations appear with very high values in the probability matrix, selecting the local maxima of the grid surface help to detect the tree trunks. Further points are assigned to tree trunks if they appear in the close proximity of trunks. Since heavy mathematical computations (such as point cloud organization, detailed shape 3D detection methods, graph network generation) are not required, the proposed algorithm works very fast compared to the existing methods. The tree classification results are found reliable even on point clouds of cities containing many different objects. As the most significant weakness, false detection of light poles, traffic signs and other objects close to trees cannot be prevented. Nevertheless, the experimental results on mobile and airborne laser scanning point clouds indicate the possible usage of the algorithm as an important step for tree growth observation, tree counting and similar applications. While the laser scanning point cloud is giving opportunity to classify even very small trees, accuracy of the results is reduced in the low point density areas further away than the scanning location. These advantages and disadvantages of two laser scanning point cloud sources are discussed in detail.

[Characteristics and Transport Patterns of Ammonia, Nitrites, Nitrates and Inorganic Nitrogen Flux at Epikarst Springs and a Subterranean Stream in Nanshan, Chongqing].

PubMed

Zhang, Yuan-zhu; He, Qiu-fang; Jiang, Yong-jun; Li, Yong

2016-04-15

In a karst groundwater system, it develops complex multiple flows because of its special geological structure and unique physical patterns of aquifers. In order to investigate the characteristics and transport patterns of ammonia, nitrite and nitrate in epikarst water and subterranean stream, the water samples were collected monthly in a fast-urbanizing karst region. The results showed distinctive characteristics of three forms of inorganic nitrogen. The concentration of inorganic nitrogen was stable in the epikarst water while it was fluctuant in the subterranean stream. Epikarst water was less affected by rainfall and sewage compared with subterranean stream. In epikarst water, the nitrate concentration was much higher than the ammonia concentration. Dissolved inorganic nitrogen, mainly from non-point source pollution related to agricultural activities, passed in and out of the epikarst water based on a series of physical; chemical and biological processes in the epikarst zone, such as ammonification, adsorption and nitrification. On the contrary, subterranean stream showed a result of NH₄⁺-N > NO₃⁻-N in dry seasons and NO₃⁻-N > NH₄⁺-N in rainy seasons. This can be due to the fact that sanitary and industrial sewage flowed into subterranean river through sinkholes, fissures and grikes in dry season. Dissolved inorganic nitrogen in subterranean river was mainly from the non-point source pollution in wet season. Non-point source pollutants entered into subterranean water by two transport ways, one by penetration along with vadose flow through fissures and grikes, and the other by conduit flow through sinkholes from the surface runoff, soil water flow and epikarst flow. The export flux of DIN was 56.05 kg · (hm² · a)⁻¹, and NH₄⁺-N and NO₃⁻-N accounted for 46.03% and 52.51%, respectively. The contributions of point-source pollution and non point-source pollution to the export flux of DIN were 25.08% and 74.92%, respectively, based on run-off division method.

URBAN/SUBURBAN WATERSHED CHARACTERIZATION

EPA Science Inventory

The ability to characterize the land surface and related pollutant source loadings is critical for reliable watershed modeling. Urban/suburban land uses are the most rapidly growing land use class, generating non-point source pollutant loadings likely to seriously impair streams...

Reduction of non-point source contaminants associated with road-deposited sediments by sweeping.

PubMed

Kim, Do-Gun; Kang, Hee-Man; Ko, Seok-Oh

2017-09-19

Road-deposited sediments (RDS) on an expressway, residual RDS collected after sweeping, and RDS removed by means of sweeping were analyzed to evaluate the degree to which sweeping removed various non-point source contaminants. The total RDS load was 393.1 ± 80.3 kg/km and the RDS, residual RDS, and swept RDS were all highly polluted with organics, nutrients, and metals. Among the metals studied, Cu, Zn, Pb, Ni, Ca, and Fe were significantly enriched, and most of the contaminants were associated with particles within the size range from 63 μm to 2 mm. Sweeping reduced RDS and its associated contaminants by 33.3-49.1% on average. We also measured the biological oxygen demand (BOD) of RDS in the present work, representing to our knowledge the first time that this has been done; we found that RDS contains a significant amount of biodegradable organics and that the reduction of BOD by sweeping was higher than that of other contaminants. Significant correlations were found between the contaminants measured, indicating that the organics and the metals originated from both exhaust and non-exhaust particles. Meanwhile, the concentrations of Cu and Ni were higher in 63 μm-2 mm particles than in smaller particles, suggesting that some metals in RDS likely exist intrinsically in particles, rather than only as adsorbates on particle surfaces. Overall, the results in this study showed that sweeping to collect RDS can be a good alternative for reduction of contaminants in runoff.

40 CFR 430.87 - Pretreatment standards for new sources (PSNS). [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Pretreatment standards for new sources (PSNS). [Reserved] 430.87 Section 430.87 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Non-Wood...

40 CFR 430.86 - Pretreatment standards for existing sources (PSES). [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Pretreatment standards for existing sources (PSES). [Reserved] 430.86 Section 430.86 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Non-Wood...

An Open-Source Auto-Calibration Routine Supporting the Stormwater Management Model

NASA Astrophysics Data System (ADS)

Tiernan, E. D.; Hodges, B. R.

2017-12-01

The stormwater management model (SWMM) is a clustered model that relies on subcatchment-averaged parameter assignments to correctly capture catchment stormwater runoff behavior. Model calibration is considered a critical step for SWMM performance, an arduous task that most stormwater management designers undertake manually. This research presents an open-source, automated calibration routine that increases the efficiency and accuracy of the model calibration process. The routine makes use of a preliminary sensitivity analysis to reduce the dimensions of the parameter space, at which point a multi-objective function, genetic algorithm (modified Non-dominated Sorting Genetic Algorithm II) determines the Pareto front for the objective functions within the parameter space. The solutions on this Pareto front represent the optimized parameter value sets for the catchment behavior that could not have been reasonably obtained through manual calibration.

Effectiveness of SWAT in characterizing the watershed hydrology in the snowy-mountainous Lower Bear Malad River (LBMR) watershed in Box Elder County, Utah

NASA Astrophysics Data System (ADS)

Salha, A. A.; Stevens, D. K.

2015-12-01

Distributed watershed models are essential for quantifying sediment and nutrient loads that originate from point and nonpoint sources. Such models are primary means towards generating pollutant estimates in ungaged watersheds and respond well at watershed scales by capturing the variability in soils, climatic conditions, land uses/covers and management conditions over extended periods of time. This effort evaluates the performance of the Soil and Water Assessment Tool (SWAT) model as a watershed level tool to investigate, manage, and characterize the transport and fate of nutrients in Lower Bear Malad River (LBMR) watershed (Subbasin HUC 16010204) in Utah. Water quality concerns have been documented and are primarily attributed to high phosphorus and total suspended sediment concentrations caused by agricultural and farming practices along with identified point sources (WWTPs). Input data such as Digital Elevation Model (DEM), land use/Land cover (LULC), soils, and climate data for 10 years (2000-2010) is utilized to quantify the LBMR streamflow. Such modeling is useful in developing the required water quality regulations such as Total Maximum Daily Loads (TMDL). Measured concentrations of nutrients were closely captured by simulated monthly nutrient concentrations based on the R2 and Nash- Sutcliffe fitness criteria. The model is expected to be able to identify contaminant non-point sources, identify areas of high pollution risk, locate optimal monitoring sites, and evaluate best management practices to cost-effectively reduce pollution and improve water quality as required by the LBMR watershed's TMDL.

40 CFR 430.120 - Applicability; description of the tissue, filter, non-woven, and paperboard from purchased pulp...

Code of Federal Regulations, 2011 CFR

2011-07-01

... tissue, filter, non-woven, and paperboard from purchased pulp subcategory. 430.120 Section 430.120... PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non-Woven, and Paperboard From Purchased Pulp Subcategory § 430.120 Applicability; description of the tissue, filter, non-woven, and...

40 CFR 430.120 - Applicability; description of the tissue, filter, non-woven, and paperboard from purchased pulp...

Code of Federal Regulations, 2014 CFR

2014-07-01

... tissue, filter, non-woven, and paperboard from purchased pulp subcategory. 430.120 Section 430.120... (CONTINUED) THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non-Woven, and Paperboard From Purchased Pulp Subcategory § 430.120 Applicability; description of the tissue, filter, non-woven...

40 CFR 430.120 - Applicability; description of the tissue, filter, non-woven, and paperboard from purchased pulp...

Code of Federal Regulations, 2012 CFR

2012-07-01

... tissue, filter, non-woven, and paperboard from purchased pulp subcategory. 430.120 Section 430.120... (CONTINUED) THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non-Woven, and Paperboard From Purchased Pulp Subcategory § 430.120 Applicability; description of the tissue, filter, non-woven...

40 CFR 430.120 - Applicability; description of the tissue, filter, non-woven, and paperboard from purchased pulp...

Code of Federal Regulations, 2013 CFR

2013-07-01

... tissue, filter, non-woven, and paperboard from purchased pulp subcategory. 430.120 Section 430.120... (CONTINUED) THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non-Woven, and Paperboard From Purchased Pulp Subcategory § 430.120 Applicability; description of the tissue, filter, non-woven...

40 CFR 430.120 - Applicability; description of the tissue, filter, non-woven, and paperboard from purchased pulp...

Code of Federal Regulations, 2010 CFR

2010-07-01

... tissue, filter, non-woven, and paperboard from purchased pulp subcategory. 430.120 Section 430.120... PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non-Woven, and Paperboard From Purchased Pulp Subcategory § 430.120 Applicability; description of the tissue, filter, non-woven, and...

Fuel Sources | Climate Neutral Research Campuses | NREL

Science.gov Websites

Fuel Sources Fuel Sources Research campuses can reduce carbon emissions and meet climate action describe how examining fuel sources may fit into your climate action plans. Considerations Sample Project are making this switch as part of their climate action plans. Another important point is the wide

Temporal dynamics of periphyton exposed to tetracycline in stream mesocosms

EPA Science Inventory

Significant amounts of antibiotics enter the environment via point and non-point sources. We examined the temporal dynamics of tetracycline exposure to stream periphyton and associated organisms across a logarithmically dosed series of experimental mesocosms, designed to mimic na...

NONPOINT SOURCES AND WATER QUALITY TRADING

EPA Science Inventory

Management of nonpoint sources (NPS) of nutrients may reduce discharge levels more cost effectively than can additional controls on point sources (PS); water quality trading (WQT), where a PS buys nutrient or sediment reductions from an NPS, may be an alternative means for the PS...

Measuring Spatial Variability of Vapor Flux to Characterize Vadose-zone VOC Sources: Flow-cell Experiments

DOE PAGES

Mainhagu, Jon; Morrison, C.; Truex, Michael J.; ...

2014-08-05

A method termed vapor-phase tomography has recently been proposed to characterize the distribution of volatile organic contaminant mass in vadose-zone source areas, and to measure associated three-dimensional distributions of local contaminant mass discharge. The method is based on measuring the spatial variability of vapor flux, and thus inherent to its effectiveness is the premise that the magnitudes and temporal variability of vapor concentrations measured at different monitoring points within the interrogated area will be a function of the geospatial positions of the points relative to the source location. A series of flow-cell experiments was conducted to evaluate this premise. Amore » well-defined source zone was created by injection and extraction of a non-reactive gas (SF6). Spatial and temporal concentration distributions obtained from the tests were compared to simulations produced with a mathematical model describing advective and diffusive transport. Tests were conducted to characterize both areal and vertical components of the application. Decreases in concentration over time were observed for monitoring points located on the opposite side of the source zone from the local–extraction point, whereas increases were observed for monitoring points located between the local–extraction point and the source zone. We found that the results illustrate that comparison of temporal concentration profiles obtained at various monitoring points gives a general indication of the source location with respect to the extraction and monitoring points.« less

Using Soluble Reactive Phosphorus and Ammonia to Identify Point Source Discharge from Large Livestock Facilities

NASA Astrophysics Data System (ADS)

Borrello, M. C.; Scribner, M.; Chessin, K.

2013-12-01

A growing body of research draws attention to the negative environmental impacts on surface water from large livestock facilities. These impacts are mostly in the form of excessive nutrient loading resulting in significantly decreased oxygen levels. Over-application of animal waste on fields as well as direct discharge into surface water from facilities themselves has been identified as the main contributor to the development of hypoxic zones in Lake Erie, Chesapeake Bay and the Gulf of Mexico. Some regulators claim enforcement of water quality laws is problematic because of the nature and pervasiveness of non-point source impacts. Any direct discharge by a facility is a violation of permits governed by the Clean Water Act, unless the facility has special dispensation for discharge. Previous research by the principal author and others has shown runoff and underdrain transport are the main mechanisms by which nutrients enter surface water. This study utilized previous work to determine if the effects of non-point source discharge can be distinguished from direct (point-source) discharge using simple nutrient analysis and dissolved oxygen (DO) parameters. Nutrient and DO parameters were measured from three sites: 1. A stream adjacent to a field receiving manure, upstream of a large livestock facility with a history of direct discharge, 2. The same stream downstream of the facility and 3. A stream in an area relatively unimpacted by large-scale agriculture (control site). Results show that calculating a simple Pearson correlation coefficient (r) of soluble reactive phosphorus (SRP) and ammonia over time as well as temperature and DO, distinguishes non-point source from point source discharge into surface water. The r value for SRP and ammonia for the upstream site was 0.01 while the r value for the downstream site was 0.92. The control site had an r value of 0.20. Likewise, r values were calculated on temperature and DO for each site. High negative correlations between temperature and DO are indicative of a relatively unimpacted stream. Results from this study are commensurate with nutrient correlations and are: r = -0.97 for the upstream site, r = -0.21 for the downstream site and r = -0.89 for the control site. Results from every site tested were statistically significant (p ≤ 0.05). These results support previous studies and demonstrate that the simple analytical techniques mentioned provide an effective means for regulatory agencies and community groups to monitor and identify point source discharge from large livestock facilities.

Chandra ACIS Sub-pixel Resolution

NASA Astrophysics Data System (ADS)

Kim, Dong-Woo; Anderson, C. S.; Mossman, A. E.; Allen, G. E.; Fabbiano, G.; Glotfelty, K. J.; Karovska, M.; Kashyap, V. L.; McDowell, J. C.

2011-05-01

We investigate how to achieve the best possible ACIS spatial resolution by binning in ACIS sub-pixel and applying an event repositioning algorithm after removing pixel-randomization from the pipeline data. We quantitatively assess the improvement in spatial resolution by (1) measuring point source sizes and (2) detecting faint point sources. The size of a bright (but no pile-up), on-axis point source can be reduced by about 20-30%. With the improve resolution, we detect 20% more faint sources when embedded on the extended, diffuse emission in a crowded field. We further discuss the false source rate of about 10% among the newly detected sources, using a few ultra-deep observations. We also find that the new algorithm does not introduce a grid structure by an aliasing effect for dithered observations and does not worsen the positional accuracy

40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Non-Wood Chemical Pulp Subcategory § 430.80 Applicability; description of the non-wood chemical pulp subcategory. The provisions of this subpart are applicable to discharges resulting...

40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Non-Wood Chemical Pulp Subcategory § 430.80 Applicability; description of the non-wood chemical pulp subcategory. The provisions of this subpart are applicable to discharges resulting...

40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Non-Wood Chemical Pulp Subcategory § 430.80 Applicability; description of the non-wood chemical pulp subcategory. The provisions of this subpart are applicable to discharges resulting...

40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions of...

40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions of...

40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions of...

40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions of...

40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions of...

40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions of...

40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions of...

40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions of...

40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

40 CFR 408.90 - Applicability; description of the non-remote Alaskan shrimp processing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-remote Alaskan shrimp processing subcategory. 408.90 Section 408.90 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing Subcategory § 408.90 Applicability; description of the non-remote Alaskan shrimp processing subcategory. The provisions of this subpart are...

40 CFR 408.220 - Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Alaskan mechanized bottom fish processing subcategory. 408.220 Section 408.220 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Mechanized Bottom Fish Processing Subcategory § 408.220 Applicability; description of the non-Alaskan mechanized bottom fish processing subcategory. The provisions of...

40 CFR 408.210 - Applicability; description of the non-Alaskan conventional bottom fish processing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Alaskan conventional bottom fish processing subcategory. 408.210 Section 408.210 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Alaskan Conventional Bottom Fish Processing Subcategory § 408.210 Applicability; description of the non-Alaskan conventional bottom fish processing subcategory. The provisions of...

Probing dim point sources in the inner Milky Way using PCAT

NASA Astrophysics Data System (ADS)

Daylan, Tansu; Portillo, Stephen K. N.; Finkbeiner, Douglas P.

2017-01-01

Poisson regression of the Fermi-LAT data in the inner Milky Way reveals an extended gamma-ray excess. An important question is whether the signal is coming from a collection of unresolved point sources, possibly old recycled pulsars, or constitutes a truly diffuse emission component. Previous analyses have relied on non-Poissonian template fits or wavelet decomposition of the Fermi-LAT data, which find evidence for a population of dim point sources just below the 3FGL flux limit. In order to be able to draw conclusions about the flux distribution of point sources at the dim end, we employ a Bayesian trans-dimensional MCMC framework by taking samples from the space of catalogs consistent with the observed gamma-ray emission in the inner Milky Way. The software implementation, PCAT (Probabilistic Cataloger), is designed to efficiently explore that catalog space in the crowded field limit such as in the galactic plane, where the model PSF, point source positions and fluxes are highly degenerate. We thus generate fair realizations of the underlying MSP population in the inner galaxy and constrain the population characteristics such as the radial and flux distribution of such sources.

Mercury Contaminated Sediment Sites: A Review Of Remedial Solutions

EPA Science Inventory

Mercury (Hg) can accumulate in sediment from point and non-point sources, depending on a number of physical, chemical, biological, geological and anthropogenic environmental processes. It is believed that the associated Hg contamination in aquatic systems can be decreased by imp...

AN INTEGRATED FRAMEWORK FOR WATERSHED ASSESSMENT AND MANAGEMENT

EPA Science Inventory

Watershed approaches to water quality management have become popular, because they can address multiple point and non-point sources and the influences of land use. Developing technically-sound watershed management strategies can be challenging due to the need to 1) account for mu...

Evaluating associations between sources of information, knowledge of the human papillomavirus, and human papillomavirus vaccine uptake for adult women in California.

PubMed

Almeida, Cristina M; Tiro, Jasmin A; Rodriguez, Michael A; Diamant, Allison L

2012-04-19

Vaccines have the potential to reduce morbidity from HPV infections if age-eligible patients receive and parents know about them. Content analyses have demonstrated significant range in the quality of HPV information obtained from different sources. The purpose of this study was to determine the pattern of associations between information source and level of knowledge about HPV and vaccine receipt/intention. We analyzed the 2007 California Health Interview Survey, a population-based, statewide random digit dial survey, using data on adult females ages 18-65 who had heard about HPV (n=16,806). One-way ANOVA and multivariate logistic regression assessed the associations between source of information (advertisement only, advertisement plus other sources, and non-advertisement sources) and knowledge of HPV (3 or greater correct on a 4-point scale). Multivariate logistic regressions were conducted on a subsample of vaccine-eligible women and parents to assess vaccine uptake or intention. Less than half of respondents (43%) correctly answered 3 or more of the HPV knowledge questions. Mean knowledge scores were significantly different when comparing women who reported advertisement only, non-advertisement, and advertisement plus other sources of information (p<0.001). In multivariate analysis, women who reported non-advertisement sources (OR 2.44, 95% CI 2.07-2.87) and advertisements plus other sources (OR 3.03, 95% CI 2.57-3.58) were more likely to have knowledge scores above the 75% level than women who relied on advertisements alone. In the subsample of vaccine-eligible women and parents, those who reported advertisements plus other sources (OR 1.85, 95% CI 1.30-2.62) were more likely to have received or intend to receive the vaccine than those who reported advertisements as their sole information source. Advertisements are the most commonly reported source of information about HPV, and while they inform women of the existence of the vaccine, they do not contribute to accurate knowledge about the virus, nor do they appear to influence vaccine uptake. Other sources may play a larger role in refining knowledge and/or improving uptake. Copyright © 2012 Elsevier Ltd. All rights reserved.

The photon fluence non-uniformity correction for air kerma near Cs-137 brachytherapy sources.

PubMed

Rodríguez, M L; deAlmeida, C E

2004-05-07

The use of brachytherapy sources in radiation oncology requires their proper calibration to guarantee the correctness of the dose delivered to the treatment volume of a patient. One of the elements to take into account in the dose calculation formalism is the non-uniformity of the photon fluence due to the beam divergence that causes a steep dose gradient near the source. The correction factors for this phenomenon have been usually evaluated by the two theories available, both of which were conceived only for point sources. This work presents the Monte Carlo assessment of the non-uniformity correction factors for a Cs-137 linear source and a Farmer-type ionization chamber. The results have clearly demonstrated that for linear sources there are some important differences among the values obtained from different calculation models, especially at short distances from the source. The use of experimental values for each specific source geometry is recommended in order to assess the non-uniformity factors for linear sources in clinical situations that require special dose calculations or when the correctness of treatment planning software is verified during the acceptance tests.

Processing Uav and LIDAR Point Clouds in Grass GIS

NASA Astrophysics Data System (ADS)

Petras, V.; Petrasova, A.; Jeziorska, J.; Mitasova, H.

2016-06-01

Today's methods of acquiring Earth surface data, namely lidar and unmanned aerial vehicle (UAV) imagery, non-selectively collect or generate large amounts of points. Point clouds from different sources vary in their properties such as number of returns, density, or quality. We present a set of tools with applications for different types of points clouds obtained by a lidar scanner, structure from motion technique (SfM), and a low-cost 3D scanner. To take advantage of the vertical structure of multiple return lidar point clouds, we demonstrate tools to process them using 3D raster techniques which allow, for example, the development of custom vegetation classification methods. Dense point clouds obtained from UAV imagery, often containing redundant points, can be decimated using various techniques before further processing. We implemented and compared several decimation techniques in regard to their performance and the final digital surface model (DSM). Finally, we will describe the processing of a point cloud from a low-cost 3D scanner, namely Microsoft Kinect, and its application for interaction with physical models. All the presented tools are open source and integrated in GRASS GIS, a multi-purpose open source GIS with remote sensing capabilities. The tools integrate with other open source projects, specifically Point Data Abstraction Library (PDAL), Point Cloud Library (PCL), and OpenKinect libfreenect2 library to benefit from the open source point cloud ecosystem. The implementation in GRASS GIS ensures long term maintenance and reproducibility by the scientific community but also by the original authors themselves.

Pollution loads in urban runoff and sanitary wastewater.

PubMed

Taebi, Amir; Droste, Ronald L

2004-07-05

While more attention has been paid in recent years to urban point source pollution control through the establishment of wastewater treatment plants in many developing countries, no considerable planning nor any serious measures have been taken to control urban non-point source pollution (urban stormwater runoff). The present study is a screening analysis to investigate the pollution loads in urban runoff compared to point source loads as a first prerequisite for planning and management of receiving water quality. To compare pollutant loads from point and non-point urban sources, the pollutant load is expressed as the weight of pollutant per hectare area per year (kg/ha.year). Unit loads were estimated in stormwater runoff, raw sanitary wastewater and secondary treatment effluents in Isfahan, Iran. Results indicate that the annual pollution load in urban runoff is lower than the annual pollution load in sanitary wastewater in areas with low precipitation but it is higher in areas with high precipitation. Two options, namely, advanced treatment (in lieu of secondary treatment) of sanitary wastewater and urban runoff quality control systems (such as detention ponds) were investigated as controlling systems for pollution discharges into receiving waters. The results revealed that for Isfahan, as a low precipitation urban area, advanced treatment is a more suitable option, but for high precipitation urban areas, urban surface runoff quality control installations were more effective for suspended solids and oxygen-demanding matter controls, and that advanced treatment is the more effective option for nutrient control.

A NEW METHOD FOR FINDING POINT SOURCES IN HIGH-ENERGY NEUTRINO DATA

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

Fang, Ke; Miller, M. Coleman

The IceCube collaboration has reported the first detection of high-energy astrophysical neutrinos, including ∼50 high-energy starting events, but no individual sources have been identified. It is therefore important to develop the most sensitive and efficient possible algorithms to identify the point sources of these neutrinos. The most popular current method works by exploring a dense grid of possible directions to individual sources, and identifying the single direction with the maximum probability of having produced multiple detected neutrinos. This method has numerous strengths, but it is computationally intensive and because it focuses on the single best location for a point source,more » additional point sources are not included in the evidence. We propose a new maximum likelihood method that uses the angular separations between all pairs of neutrinos in the data. Unlike existing autocorrelation methods for this type of analysis, which also use angular separations between neutrino pairs, our method incorporates information about the point-spread function and can identify individual point sources. We find that if the angular resolution is a few degrees or better, then this approach reduces both false positive and false negative errors compared to the current method, and is also more computationally efficient up to, potentially, hundreds of thousands of detected neutrinos.« less

Fiscal year 1988 program report: Pennsylvania Center for Water Resources Research

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

McDonnell, A.J.

1989-08-01

Three projects and a program of technology transfer were conducted under the Pennsylvania Fiscal Year 1988 State Water Resources Research Grants Program (PL 98-242, Sect. 104). In a completed study focused on the protection of water supplies, mature slow sand filters were found to remove 100 percent of Cryptosporidium and Giardia cysts. A site specific study examined the behavior of sedimentary iron and manganese in an acid mine drainage wetland system. A study was initiated to link a comprehensive non-point source model, AGNPS with current GIS technology to enhance the models' utility for evaluating regional water quality problems related tomore » non-point source agricultural pollution.« less

Development of EPA OTM 10 for Landfill Applications, Interim Report

EPA Science Inventory

Quantification of greenhouse gas emissions from area sources is of increasing importance. Due to the spatial extent and non homogenous nature of many area sources, assessment of fugitive emissions using traditional point sampling techniques can be problematic. To address this, th...

Field-deployed Metabolomics for Assessing Waters Impacted by Point and Non-Point Sources of Contamination

EPA Science Inventory

Metabolomics is becoming well-established for studying chemical contaminant-induced alterations to normal biological function. For example, the literature contains a wealth of laboratory-based studies involving analysis of samples from organisms exposed to individual chemical tox...

Ecological consequences of antibiotic exposure to periphyton in naturally colonizing stream mesocosms

EPA Science Inventory

Tetracycline and its derivatives are extensively used human and animal antibiotics, and enter stream ecosystems via point and non-point sources. Laboratory studies indicate that microbial organisms are more sensitive to antibiotics than invertebrates or fish, and may indicate t...

Field-deployed Metabolomics for Assessing Surface Waters Impacted by Point and Non-Point Sources of Contamination

EPA Science Inventory

Metabolomics has become well-established for studying chemical contaminant-induced alterations to normal biological function. For example, the literature contains a wealth of laboratory-based studies involving analysis of samples from organisms exposed to individual chemical toxi...

Consequences of tetracycline exposure to stream periphyton in an experimental mesocosm study

EPA Science Inventory

A significant amount of ingested, injected, and applied antibiotics are not metabolized but are excreted; entering the environment via point and non-point sources. Tetracycline and its derivatives are among the most extensively used human and animal antibiotics. We examined the ...

A multicentre audit of HDR/PDR brachytherapy absolute dosimetry in association with the INTERLACE trial (NCT015662405).

PubMed

Díez, P; Aird, E G A; Sander, T; Gouldstone, C A; Sharpe, P H G; Lee, C D; Lowe, G; Thomas, R A S; Simnor, T; Bownes, P; Bidmead, M; Gandon, L; Eaton, D; Palmer, A L

2017-11-09

A UK multicentre audit to evaluate HDR and PDR brachytherapy has been performed using alanine absolute dosimetry. This is the first national UK audit performing an absolute dose measurement at a clinically relevant distance (20 mm) from the source. It was performed in both INTERLACE (a phase III multicentre trial in cervical cancer) and non-INTERLACE brachytherapy centres treating gynaecological tumours. Forty-seven UK centres (including the National Physical Laboratory) were visited. A simulated line source was generated within each centre's treatment planning system and dwell times calculated to deliver 10 Gy at 20 mm from the midpoint of the central dwell (representative of Point A of the Manchester system). The line source was delivered in a water-equivalent plastic phantom (Barts Solid Water) encased in blocks of PMMA (polymethyl methacrylate) and charge measured with an ion chamber at 3 positions (120° apart, 20 mm from the source). Absorbed dose was then measured with alanine at the same positions and averaged to reduce source positional uncertainties. Charge was also measured at 50 mm from the source (representative of Point B of the Manchester system). Source types included 46 HDR and PDR 192 Ir sources, (7 Flexisource, 24 mHDR-v2, 12 GammaMed HDR Plus, 2 GammaMed PDR Plus, 1 VS2000) and 1 HDR 60 Co source, (Co0.A86). Alanine measurements when compared to the centres' calculated dose showed a mean difference (±SD) of  +1.1% (±1.4%) at 20 mm. Differences were also observed between source types and dose calculation algorithm. Ion chamber measurements demonstrated significant discrepancies between the three holes mainly due to positional variation of the source within the catheter (0.4%-4.9% maximum difference between two holes). This comprehensive audit of absolute dose to water from a simulated line source showed all centres could deliver the prescribed dose to within 5% maximum difference between measurement and calculation.

Estimation of Phosphorus Emissions in the Upper Iguazu Basin (brazil) Using GIS and the More Model

NASA Astrophysics Data System (ADS)

Acosta Porras, E. A.; Kishi, R. T.; Fuchs, S.; Hilgert, S.

2016-06-01

Pollution emissions into the drainage basin have direct impact on surface water quality. These emissions result from human activities that turn into pollution loads when they reach the water bodies, as point or diffuse sources. Their pollution potential depends on the characteristics and quantity of the transported materials. The estimation of pollution loads can assist decision-making in basin management. Knowledge about the potential pollution sources allows for a prioritization of pollution control policies to achieve the desired water quality. Consequently, it helps avoiding problems such as eutrophication of water bodies. The focus of the research described in this study is related to phosphorus emissions into river basins. The study area is the upper Iguazu basin that lies in the northeast region of the State of Paraná, Brazil, covering about 2,965 km2 and around 4 million inhabitants live concentrated on just 16% of its area. The MoRE (Modeling of Regionalized Emissions) model was used to estimate phosphorus emissions. MoRE is a model that uses empirical approaches to model processes in analytical units, capable of using spatially distributed parameters, covering both, emissions from point sources as well as non-point sources. In order to model the processes, the basin was divided into 152 analytical units with an average size of 20 km2. Available data was organized in a GIS environment. Using e.g. layers of precipitation, the Digital Terrain Model from a 1:10000 scale map as well as soils and land cover, which were derived from remote sensing imagery. Further data is used, such as point pollution discharges and statistical socio-economic data. The model shows that one of the main pollution sources in the upper Iguazu basin is the domestic sewage that enters the river as point source (effluents of treatment stations) and/or as diffuse pollution, caused by failures of sanitary sewer systems or clandestine sewer discharges, accounting for about 56% of the emissions. Second significant shares of emissions come from direct runoff or groundwater, being responsible for 32% of the total emissions. Finally, agricultural erosion and industry pathways represent 12% of emissions. This study shows that MoRE is capable of producing valid emission calculation on a relatively reduced input data basis.

Error Estimation and Compensation in Reduced Dynamic Models of Large Space Structures

DTIC Science & Technology

1987-04-23

PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION (if aplicable ) AFWAL I FIBRA F33615-84-C-3219 8c. ADDRESS (City, Stateand ZIP Code) ?0 SOURCE...10 Modes of the Full Model 15 5 Comparison of Various Reduced Models 18 6 Driving Point Mobilities , Wing Tip (Z55) 19 7 Driving Point Mobilities , Wing...Root Trailing Edge (Z19) 20 8 AMI Improvement 23 9 Frequency Domain Solution, Driving Point Mobilities , Wing Tip (Z55), RM1I 25 10 Frequency Domain

Improved bioluminescence and fluorescence reconstruction algorithms using diffuse optical tomography, normalized data, and optimized selection of the permissible source region

PubMed Central

Naser, Mohamed A.; Patterson, Michael S.

2011-01-01

Reconstruction algorithms are presented for two-step solutions of the bioluminescence tomography (BLT) and the fluorescence tomography (FT) problems. In the first step, a continuous wave (cw) diffuse optical tomography (DOT) algorithm is used to reconstruct the tissue optical properties assuming known anatomical information provided by x-ray computed tomography or other methods. Minimization problems are formed based on L1 norm objective functions, where normalized values for the light fluence rates and the corresponding Green’s functions are used. Then an iterative minimization solution shrinks the permissible regions where the sources are allowed by selecting points with higher probability to contribute to the source distribution. Throughout this process the permissible region shrinks from the entire object to just a few points. The optimum reconstructed bioluminescence and fluorescence distributions are chosen to be the results of the iteration corresponding to the permissible region where the objective function has its global minimum This provides efficient BLT and FT reconstruction algorithms without the need for a priori information about the bioluminescence sources or the fluorophore concentration. Multiple small sources and large distributed sources can be reconstructed with good accuracy for the location and the total source power for BLT and the total number of fluorophore molecules for the FT. For non-uniform distributed sources, the size and magnitude become degenerate due to the degrees of freedom available for possible solutions. However, increasing the number of data points by increasing the number of excitation sources can improve the accuracy of reconstruction for non-uniform fluorophore distributions. PMID:21326647

40 CFR 408.120 - Applicability; description of the Southern non-breaded shrimp processing in the contiguous States...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Southern non-breaded shrimp processing in the contiguous States subcategory. 408.120 Section 408.120... CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Southern Non-Breaded Shrimp Processing in... shrimp processing in the contiguous States subcategory. The provisions of this subpart are applicable to...

40 CFR 408.120 - Applicability; description of the Southern non-breaded shrimp processing in the contiguous States...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Southern non-breaded shrimp processing in the contiguous States subcategory. 408.120 Section 408.120... CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Southern Non-Breaded Shrimp Processing in... shrimp processing in the contiguous States subcategory. The provisions of this subpart are applicable to...

40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart are...

40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart are...

Fabrication and In Situ Testing of Scalable Nitrate-Selective Electrodes for Distributed Observations

NASA Astrophysics Data System (ADS)

Harmon, T. C.; Rat'ko, A.; Dietrich, H.; Park, Y.; Wijsboom, Y. H.; Bendikov, M.

2008-12-01

Inorganic nitrogen (nitrate (NO3-) and ammonium (NH+)) from chemical fertilizer and livestock waste is a major source of pollution in groundwater, surface water and the air. While some sources of these chemicals, such as waste lagoons, are well-defined, their application as fertilizer has the potential to create distributed or non-point source pollution problems. Scalable nitrate sensors (small and inexpensive) would enable us to better assess non-point source pollution processes in agronomic soils, groundwater and rivers subject to non-point source inputs. This work describes the fabrication and testing of inexpensive PVC-membrane- based ion selective electrodes (ISEs) for monitoring nitrate levels in soil water environments. ISE-based sensors have the advantages of being easy to fabricate and use, but suffer several shortcomings, including limited sensitivity, poor precision, and calibration drift. However, modern materials have begun to yield more robust ISE types in laboratory settings. This work emphasizes the in situ behavior of commercial and fabricated sensors in soils subject to irrigation with dairy manure water. Results are presented in the context of deployment techniques (in situ versus soil lysimeters), temperature compensation, and uncertainty analysis. Observed temporal responses of the nitrate sensors exhibited diurnal cycling with elevated nitrate levels at night and depressed levels during the day. Conventional samples collected via lysimeters validated this response. It is concluded that while modern ISEs are not yet ready for long-term, unattended deployment, short-term installations (on the order of 2 to 4 days) are viable and may provide valuable insights into nitrogen dynamics in complex soil systems.

Performance of Four-Leg VSC based DSTATCOM using Single Phase P-Q Theory

NASA Astrophysics Data System (ADS)

Jampana, Bangarraju; Veramalla, Rajagopal; Askani, Jayalaxmi

2017-02-01

This paper presents single-phase P-Q theory for four-leg VSC based distributed static compensator (DSTATCOM) in the distribution system. The proposed DSTATCOM maintains unity power factor at source, zero voltage regulation, eliminates current harmonics, load balancing and neutral current compensation. The advantage of using four-leg VSC based DSTATCOM is to eliminate isolated/non-isolated transformer connection at point of common coupling (PCC) for neutral current compensation. The elimination of transformer connection at PCC with proposed topology will reduce cost of DSTATCOM. The single-phase P-Q theory control algorithm is used to extract fundamental component of active and reactive currents for generation of reference source currents which is based on indirect current control method. The proposed DSTATCOM is modelled and the results are validated with various consumer loads under unity power factor and zero voltage regulation modes in the MATLAB R2013a environment using simpower system toolbox.

Estimation of runoff and sediment yield in the Redrock Creek watershed using AnnAGNPS and GIS

USGS Publications Warehouse

Tsou, Ming‐shu; Zhan, X.-Y.

2004-01-01

Sediment has been identified as a significant threat to water quality and channel clogging that in turn may lead to river flooding. With the increasing awareness of the impairment from sediment to water bodies in a watershed, identifying the locations of the major sediment sources and reducing the sediment through management practices will be important for an effective watershed management. The annualized agricultural non-point source pollution (AnnAGNPS) model and newly developed GIS interface for it were applied in a small agricultural watershed, Redrock Creek watershed, Kansas, in this pilot study for exploring the effectiveness of using this model as a management tool. The calibrated model appropriately simulated monthly runoff and sediment yield through the practices in this study and potentially suggested the ways of sediment reduction through evaluating the changes of land use and field operation in the model for the purpose of watershed management.

40 CFR 421.84 - Standards of performance for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Primary Zinc... achieve the following new source performance standards: (a) Subpart H—Zinc Reduction Furnace Wet Air.../kg (pounds per million pounds) of zinc reduced Cadmium .334 .134 Copper 2.135 1.018 Lead .467 .217...

UTILIZATION OF LANDSCAPE INDICATORS TO MODEL WATER QUALITY

EPA Science Inventory

Many water-bodies within the United States are contaminated by, non-point source (NFS) pollution, which is defined as those materials posing a threat to water quality arising from a number of individual sources and diffused through hydrologic processes. One such NPS pollu...

Nearby Dwarf Stars: Duplicity, Binarity, and Masses

NASA Astrophysics Data System (ADS)

Mason, Brian D.; Hartkopf, William I.; Henry, Todd J.; Jao, Wei-Chun; Subasavage, John; Riedel, Adric; Winters, Jennifer

2010-02-01

Double stars have proven to be both a blessing and a curse for astronomers since their discovery over two centuries ago. They remain the only reliable source of masses, the most fundamental parameter defining stars. On the other hand, their sobriquet ``vermin of the sky'' is well-earned, due to the complications they present to both observers and theoreticians. These range from non-linear proper motions to stray light in detectors, to confusion in pointing of instruments due to non-symmetric point spread functions, to angular momentum conservation in multiple stars which results in binaries closer than allowed by evolution of two single stars. This proposal is primarily focused on targets where precise astrophysical information is sorely lacking: white dwarfs, red dwarfs, and subdwarfs. The proposed work will refine current statistics regarding duplicity (chance alignments of nearby point sources) and binarity (actual physical relationships), and improve the precisions and accuracies of stellar masses. Several targets support Riedel's and Winters' theses.

Nearby Dwarf Stars: Duplicity, Binarity, and Masses

NASA Astrophysics Data System (ADS)

Mason, Brian D.; Hartkopf, William I.; Henry, Todd J.; Jao, Wei-Chun; Subasavage, John; Riedel, Adric; Winters, Jennifer

2009-08-01

Double stars have proven to be both a blessing and a curse for astronomers since their discovery over two centuries ago. They remain the only reliable source of masses, the most fundamental parameter defining stars. On the other hand, their sobriquet ``vermin of the sky'' is well-earned, due to the complications they present to both observers and theoreticians. These range from non-linear proper motions to stray light in detectors, to confusion in pointing of instruments due to non-symmetric point spread functions, to angular momentum conservation in multiple stars which results in binaries closer than allowed by evolution of two single stars. This proposal is primarily focused on targets where precise astrophysical information is sorely lacking: white dwarfs, red dwarfs, and subdwarfs. The proposed work will refine current statistics regarding duplicity (chance alignments of nearby point sources) and binarity (actual physical relationships), and improve the precisions and accuracies of stellar masses. Several targets support Riedel's and Winters' theses.

The optimal on-source region size for detections with counting-type telescopes

NASA Astrophysics Data System (ADS)

Klepser, S.

2017-03-01

Source detection in counting type experiments such as Cherenkov telescopes often involves the application of the classical Eq. (17) from the paper of Li & Ma (1983) to discrete on- and off-source regions. The on-source region is typically a circular area with radius θ in which the signal is expected to appear with the shape of the instrument point spread function (PSF). This paper addresses the question of what is the θ that maximises the probability of detection for a given PSF width and background event density. In the high count number limit and assuming a Gaussian PSF profile, the optimum is found to be at ζ∞2 ≈ 2.51 times the squared PSF width σPSF392. While this number is shown to be a good choice in many cases, a dynamic formula for cases of lower count numbers, which favour larger on-source regions, is given. The recipe to get to this parametrisation can also be applied to cases with a non-Gaussian PSF. This result can standardise and simplify analysis procedures, reduce trials and eliminate the need for experience-based ad hoc cut definitions or expensive case-by-case Monte Carlo simulations.

Non-fluorescent nanoscopic monitoring of a single trapped nanoparticle via nonlinear point sources.

PubMed

Yoon, Seung Ju; Lee, Jungmin; Han, Sangyoon; Kim, Chang-Kyu; Ahn, Chi Won; Kim, Myung-Ki; Lee, Yong-Hee

2018-06-07

Detection of single nanoparticles or molecules has often relied on fluorescent schemes. However, fluorescence detection approaches limit the range of investigable nanoparticles or molecules. Here, we propose and demonstrate a non-fluorescent nanoscopic trapping and monitoring platform that can trap a single sub-5-nm particle and monitor it with a pair of floating nonlinear point sources. The resonant photon funnelling into an extremely small volume of ~5 × 5 × 7 nm 3 through the three-dimensionally tapered 5-nm-gap plasmonic nanoantenna enables the trapping of a 4-nm CdSe/ZnS quantum dot with low intensity of a 1560-nm continuous-wave laser, and the pumping of 1560-nm femtosecond laser pulses creates strong background-free second-harmonic point illumination sources at the two vertices of the nanoantenna. Under the stable trapping conditions, intermittent but intense nonlinear optical spikes are observed on top of the second-harmonic signal plateau, which is identified as the 3.0-Hz Kramers hopping of the quantum dot trapped in the 5-nm gap.

Point-source helicity injection for ST plasma startup in Pegasus

NASA Astrophysics Data System (ADS)

Redd, A. J.; Battaglia, D. J.; Bongard, M. W.; Fonck, R. J.; Schlossberg, D. J.

2009-11-01

Plasma current guns are used as point-source DC helicity injectors for forming non-solenoidal tokamak plasmas in the Pegasus Toroidal Experiment. Discharges driven by this injection scheme have achieved Ip>= 100 kA using Iinj<= 4 kA. They form at the outboard midplane, transition to a tokamak-like equilibrium, and continue to grow inward as Ip increases due to helicity injection and outer- PF induction. The maximum Ip is determined by helicity balance (injection rate vs resistive dissipation) and a Taylor relaxation limit, in which Ip√ITF Iinj/w, where w is the radial thickness of the gun-driven edge. Preliminary experiments tentatively confirm these scalings with ITF, Iinj, and w, increasing confidence in this simple relaxation model. Adding solenoidal inductive drive during helicity injection can push Ip up to, but not beyond, the predicted relaxation limit, demonstrating that this is a hard performance limit. Present experiments are focused on increasing the injection voltage (i.e., helicity injection rate) and reducing w. Near-term goals are to further test scalings predicted by the simple relaxation model and to study in detail the observed bursty n=1 activity correlated with rapid increases in Ip.

Enhanced gamma ray sensitivity in bismuth triiodide sensors through volumetric defect control

DOE PAGES

Johns, Paul M.; Baciak, James E.; Nino, Juan C.

2016-09-02

In some of the more attractive semiconducting compounds for ambient temperature radiation detector applications are impacted by low charge collection efficiency due to the presence of point and volumetric defects. This has been particularly true in the case of BiI 3, which features very attractive properties (density, atomic number, band gap, etc.) to serve as a gamma ray detector, but has yet to demonstrate its full potential. Here, we show that by applying growth techniques tailored to reduce defects, the spectral performance of this promising semiconductor can be realized. Gamma ray spectra from >100 keV source emissions are now obtainedmore » from high quality Sb:BiI 3 bulk crystals with limited concentrations of defects (point and extended). The spectra acquired in these high quality crystals feature photopeaks with resolution of 2.2% at 662 keV. Infrared microscopy is used to compare the local microstructure between radiation sensitive and non-responsive crystals. Our work demonstrates that BiI 3 can be prepared in melt-grown detector-grade samples with superior quality and can acquire the spectra from a variety of gamma ray sources.« less

Water Quality Protection from Nutrient Pollution: Case ...

EPA Pesticide Factsheets

Water bodies and coastal areas around the world are threatened by increases in upstream sediment and nutrient loads, which influence drinking water sources, aquatic species, and other ecologic functions and services of streams, lakes, and coastal water bodies. For example, increased nutrient fluxes from the Mississippi River Basin have been linked to increased occurrences of seasonal hypoxia in northern Gulf of Mexico. Lake Erie is another example where in the summer of 2014 nutrients, nutrients, particularly phosphorus, washed from fertilized farms, cattle feedlots, and leaky septic systems; caused a severe algae bloom, much of it poisonous; and resulted in the loss of drinking water for a half-million residents. Our current management strategies for point and non-point source nutrient loadings need to be improved to protect and meet the expected increased future demands of water for consumption, recreation, and ecological integrity. This presentation introduces management practices being implemented and their effectiveness in reducing nutrient loss from agricultural fields, a case analysis of nutrient pollution of the Grand Lake St. Marys and possible remedies, and ongoing work on watershed modeling to improve our understanding on nutrient loss and water quality. Presented at the 3rd International Conference on Water Resource and Environment.

Spectroscopic Chemical Analysis Methods and Apparatus

NASA Technical Reports Server (NTRS)

Hug, William F.; Reid, Ray D.

2012-01-01

This invention relates to non-contact spectroscopic methods and apparatus for performing chemical analysis and the ideal wavelengths and sources needed for this analysis. It employs deep ultraviolet (200- to 300-nm spectral range) electron-beam-pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor lightemitting devices, and hollow cathode metal ion lasers. Three achieved goals for this innovation are to reduce the size (under 20 L), reduce the weight [under 100 lb (.45 kg)], and reduce the power consumption (under 100 W). This method can be used in microscope or macroscope to provide measurement of Raman and/or native fluorescence emission spectra either by point-by-point measurement, or by global imaging of emissions within specific ultraviolet spectral bands. In other embodiments, the method can be used in analytical instruments such as capillary electrophoresis, capillary electro-chromatography, high-performance liquid chromatography, flow cytometry, and related instruments for detection and identification of unknown analytes using a combination of native fluorescence and/or Raman spectroscopic methods. This design provides an electron-beampumped semiconductor radiation-producing method, or source, that can emit at a wavelength (or wavelengths) below 300 nm, e.g. in the deep ultraviolet between about 200 and 300 nm, and more preferably less than 260 nm. In some variations, the method is to produce incoherent radiation, while in other implementations it produces laser radiation. In some variations, this object is achieved by using an AlGaN emission medium, while in other implementations a diamond emission medium may be used. This instrument irradiates a sample with deep UV radiation, and then uses an improved filter for separating wavelengths to be detected. This provides a multi-stage analysis of the sample. To avoid the difficulties related to producing deep UV semiconductor sources, a pumping approach has been developed that uses ballistic electron beam injection directly into the active region of a wide bandgap semiconductor material.

Does improved access to water supply by rural households enhance the concept of safe water at the point of use? A case study from deep rural South Africa.

PubMed

Jagals, P

2006-01-01

The concept of safe water is defined by three principles: the health-related quality must be suitable, the supply/source must be accessible and the water must constantly be available in quantities sufficient for the intended use. If any one (or more) of these three elements is missing from a water services improvement programme, providing safe water is not successfully achieved. A study in a deep rural area in South Africa showed that providing small communities, using untreated river water as their only water source, with good quality water through a piped distribution system and accessible at communal taps did not fall within our parameters of safe water. The parameters for measuring the three principles were: absence of Escherichia coli in drinking water samples; accessibility by improving tap distances to within 200 m from each household; availability by assessing whether households have at least 25 L per person per day. Results show that although E. coli levels were reduced significantly, households were still consuming water with E. coli numbers at non-compliant levels. Access (distance) was improved from an average of 750 m from households to river source to an average of 120 m to new on-tap source points. This did not result in significant increases in household quantities, which on average remained around 18 L per person per day.

Efficient inversion of volcano deformation based on finite element models : An application to Kilauea volcano, Hawaii

NASA Astrophysics Data System (ADS)

Charco, María; González, Pablo J.; Galán del Sastre, Pedro

2017-04-01

The Kilauea volcano (Hawaii, USA) is one of the most active volcanoes world-wide and therefore one of the better monitored volcanoes around the world. Its complex system provides a unique opportunity to investigate the dynamics of magma transport and supply. Geodetic techniques, as Interferometric Synthetic Aperture Radar (InSAR) are being extensively used to monitor ground deformation at volcanic areas. The quantitative interpretation of such surface ground deformation measurements using geodetic data requires both, physical modelling to simulate the observed signals and inversion approaches to estimate the magmatic source parameters. Here, we use synthetic aperture radar data from Sentinel-1 radar interferometry satellite mission to image volcano deformation sources during the inflation along Kilauea's Southwest Rift Zone in April-May 2015. We propose a Finite Element Model (FEM) for the calculation of Green functions in a mechanically heterogeneous domain. The key aspect of the methodology lies in applying the reciprocity relationship of the Green functions between the station and the source for efficient numerical inversions. The search for the best-fitting magmatic (point) source(s) is generally conducted for an array of 3-D locations extending below a predefined volume region. However, our approach allows to reduce the total number of Green functions to the number of the observation points by using the, above mentioned, reciprocity relationship. This new methodology is able to accurately represent magmatic processes using physical models capable of simulating volcano deformation in non-uniform material properties distribution domains, which eventually will lead to better description of the status of the volcano.

Generating Accurate 3d Models of Architectural Heritage Structures Using Low-Cost Camera and Open Source Algorithms

NASA Astrophysics Data System (ADS)

Zacharek, M.; Delis, P.; Kedzierski, M.; Fryskowska, A.

2017-05-01

These studies have been conductedusing non-metric digital camera and dense image matching algorithms, as non-contact methods of creating monuments documentation.In order toprocess the imagery, few open-source software and algorithms of generating adense point cloud from images have been executed. In the research, the OSM Bundler, VisualSFM software, and web application ARC3D were used. Images obtained for each of the investigated objects were processed using those applications, and then dense point clouds and textured 3D models were created. As a result of post-processing, obtained models were filtered and scaled.The research showedthat even using the open-source software it is possible toobtain accurate 3D models of structures (with an accuracy of a few centimeters), but for the purpose of documentation and conservation of cultural and historical heritage, such accuracy can be insufficient.

Prospective epidemiological pilot study on the morbidity of bathers exposed to tropical recreational waters and sand.

PubMed

Sánchez-Nazario, Elia E; Santiago-Rodriguez, Tasha M; Toranzos, Gary A

2014-06-01

A prospective cohort epidemiological pilot study was performed at three tropical beaches with point- and non-point-sources of fecal pollution to characterize the risk of illness among swimmers and non-swimmers. There was an increased risk of illness in swimmers as compared to non-swimmers, even when waters met current microbial standards for recreational water quality. Illnesses included gastrointestinal (GI), skin and respiratory symptoms, earache and fever. Odds ratios (ORs) ranged from 0.32 to 42.35 (GI illness), 0.69 to 3.12 (skin infections), 0.71 to 3.21 (respiratory symptoms), 0.52 to 15.32 (earache) and 0.80 to 1.68 (fever), depending on the beach sampled. The indicators that better predicted the risks of symptoms (respiratory) in tropical recreational waters were total (somatic and male-specific) coliphages (OR = 1.56, p < 0.10, R(2) = 3.79%) and Escherichia coli (OR = 1.38, p < 0.10, R(2) = 1.97%). The present study supports the potential of coliphages as good predictors of risks of respiratory illness in tropical recreational waters. This is the first study that has determined risks of illness after exposure to tropical recreational waters with point- and non-point sources of fecal contamination. The results give an opportunity to perform epidemiological studies in tropical recreational waters in Puerto Rico which can include more participants and other indicators and detection techniques.

Monitoring for Pesticides in Groundwater and Surface Water in Nevada, 2008

USGS Publications Warehouse

Thodal, Carl E.; Carpenter, Jon; Moses, Charles W.

2009-01-01

Commercial pesticide applicators, farmers, and homeowners apply about 1 billion pounds of pesticides annually to agricultural land, non-crop land, and urban areas throughout the United States (Gilliom and others, 2006, p. 1). The U.S. Environmental Protection Agency (USEPA) defines a pesticide as any substance used to kill or control insects, weeds, plant diseases, and other pest organisms. Although there are important benefits from the proper use of pesticides, like crop protection and prevention of human disease outbreaks, there are also risks. One risk is the contamination of groundwater and surface-water resources. Data collected during 1992-2001 from 51 major hydrologic systems across the United States indicate that one or more pesticide or pesticide breakdown product was detected in more than 50 percent of 5,057 shallow (less than 20 feet below land surface) wells and in all of the 186 stream sites that were sampled in agricultural and urban areas (Gilliom and others, 2006, p. 2-4). Pesticides can contaminate surface water and groundwater from both point sources and non-point sources. Point sources are from specific locations such as spill sites, disposal sites, pesticide drift during application, and application of pesticides to control aquatic pests. Non-point sources represent the dominant source of surface water and groundwater contamination and may include agricultural and urban runoff, erosion, leaching from application sites, and precipitation that has become contaminated by upwind applications. Pesticides typically enter surface water when rainfall or irrigation exceeds the infiltration capacity of soil and resulting runoff then transports pesticides to streams, rivers, and other surface-water bodies. Contamination of groundwater may result directly from spills near poorly sealed well heads and from pesticide applications through improperly designed or malfunctioning irrigation systems that also are used to apply pesticides (chemigation; Carpenter and Johnson, 1997). Groundwater contamination also may come indirectly by the percolation of agricultural and urban irrigation water through soil layers and into groundwater and from pesticide residue in surface water, such as drainage ditches, streams, and municipal wastewater. To protect surface water and groundwater from pesticide contamination, the USEPA requires that all states establish a pesticide management plan. The Nevada Department of Agriculture (NDOA), with assistance from the USEPA, developed a management program of education (Hefner and Donaldson, 2006), regulation (Johnson and others, 2006), and monitoring (Pennington and others, 2001) to protect Nevada's water resources from pesticide contaminants. Sampling sites are located in areas where urban or agricultural pesticide use may affect groundwater, water bodies, endangered species, and other aquatic life. Information gathered from these sites is used by NDOA to help make regulatory decisions that will protect human and environmental health by reducing and eliminating the occurrence of pesticide contamination. This fact sheet describes current (2008) pesticide monitoring of groundwater and streams by the NDOA in Nevada and supersedes Pennington and others (2001).

WET WEATHER FLOW (WWF) MANAGEMENT AND CONTROL

EPA Science Inventory

Research emphasizes structural and nonstructural approaches that reduce the impacts of WWF-related stressors on receiving waters. Urban WWF pollution emanates from both point sources and diffuse sources including CSOs, SSOs, and stormwater from sewered and unsewered systems. EPA’...

Temperature dependence of long coherence times of oxide charge qubits.

PubMed

Dey, A; Yarlagadda, S

2018-02-22

The ability to maintain coherence and control in a qubit is a major requirement for quantum computation. We show theoretically that long coherence times can be achieved at easily accessible temperatures (such as boiling point of liquid helium) in small (i.e., ~10 nanometers) charge qubits of oxide double quantum dots when only optical phonons are the source of decoherence. In the regime of strong electron-phonon coupling and in the non-adiabatic region, we employ a duality transformation to make the problem tractable and analyze the dynamics through a non-Markovian quantum master equation. We find that the system decoheres after a long time, despite the fact that no energy is exchanged with the bath. Detuning the dots to a fraction of the optical phonon energy, increasing the electron-phonon coupling, reducing the adiabaticity, or decreasing the temperature enhances the coherence time.

NONPOINT SOURCE MODEL CALIBRATION IN HONEY CREEK WATERSHED

EPA Science Inventory

The U.S. EPA Non-Point Source Model has been applied and calibrated to a fairly large (187 sq. mi.) agricultural watershed in the Lake Erie Drainage basin of north central Ohio. Hydrologic and chemical routing algorithms have been developed. The model is evaluated for suitability...

UTILIZATION OF LANDSCAPE INDICATORS TO MODEL WATERSHED IMPAIRMENT

EPA Science Inventory

Many water-bodies within the United States are contaminated by non-point source (NPS) pollution, which is defined as those materials posing a threat to water quality arising from a number of individual sources and diffused through hydrologic 13romses. One such NPS
pol...

CHARACTERIZING SPATIAL AND TEMPORAL DYNAMICS: DEVELOPMENT OF A GRID-BASED WATERSHED MERCURY LOADING MODEL

EPA Science Inventory

A distributed grid-based watershed mercury loading model has been developed to characterize spatial and temporal dynamics of mercury from both point and non-point sources. The model simulates flow, sediment transport, and mercury dynamics on a daily time step across a diverse lan...

Wastewater Treatment and Reuse by Land Application, Volume I - Summary.

ERIC Educational Resources Information Center

Pound, Charles E.; Crites, Ronald W.

This report is included in the Environmental Protection Agency's (EPA) environmental protection technology series which describes research performed to develop and demonstrate instrumentation, equipment and methodology to repair or prevent environmental degradation from point and non-point sources of pollution. This document is a summary of a…

Health burden of gastrointestinal symptoms resulting from swimming in fecally-contaminated recreational waters.

EPA Science Inventory

Millions of people swim and recreate in oceans and lakes every year. Fecal contamination of these waters can occur from sewage discharges, runoff, and other point and non-point sources. Measures of fecal indicator contamination (e.g., the fecal indicator bacteria E. coli and Ent...

PSFGAN: a generative adversarial network system for separating quasar point sources and host galaxy light

NASA Astrophysics Data System (ADS)

Stark, Dominic; Launet, Barthelemy; Schawinski, Kevin; Zhang, Ce; Koss, Michael; Turp, M. Dennis; Sartori, Lia F.; Zhang, Hantian; Chen, Yiru; Weigel, Anna K.

2018-06-01

The study of unobscured active galactic nuclei (AGN) and quasars depends on the reliable decomposition of the light from the AGN point source and the extended host galaxy light. The problem is typically approached using parametric fitting routines using separate models for the host galaxy and the point spread function (PSF). We present a new approach using a Generative Adversarial Network (GAN) trained on galaxy images. We test the method using Sloan Digital Sky Survey r-band images with artificial AGN point sources added that are then removed using the GAN and with parametric methods using GALFIT. When the AGN point source is more than twice as bright as the host galaxy, we find that our method, PSFGAN, can recover point source and host galaxy magnitudes with smaller systematic error and a lower average scatter (49 per cent). PSFGAN is more tolerant to poor knowledge of the PSF than parametric methods. Our tests show that PSFGAN is robust against a broadening in the PSF width of ± 50 per cent if it is trained on multiple PSFs. We demonstrate that while a matched training set does improve performance, we can still subtract point sources using a PSFGAN trained on non-astronomical images. While initial training is computationally expensive, evaluating PSFGAN on data is more than 40 times faster than GALFIT fitting two components. Finally, PSFGAN is more robust and easy to use than parametric methods as it requires no input parameters.

Transformation of chlorpyrifos and chlorpyrifos-methyl in prairie pothole pore waters.

PubMed

Adams, Rachel M; McAdams, Brandon C; Arnold, William A; Chin, Yu-Ping

2016-11-09

Non-point source pesticide pollution is a concern for wetlands in the prairie pothole region (PPR). Recent studies have demonstrated that reduced sulfur species (e.g., bisulfide and polysulfides) in PPR wetland pore waters directly undergo reactions with chloroacetanilide and dinitroaniline compounds. In this paper, the abiotic transformation of two organophosphate compounds, chlorpyrifos and chlorpyrifos-methyl, was studied in PPR wetland pore waters. Chlorpyrifos-methyl reacted significantly faster (up to 4 times) in pore water with reduced sulfur species relative to hydrolysis. No rate enhancement was observed in the transformation of chlorpyrifos in pore water with reduced sulfur species. The lack of reactivity was most likely caused by steric hindrance from the ethyl groups and partitioning to dissolved organic matter (DOM), thereby shielding chlorpyrifos from nucleophilic attack. Significant decreases in reaction rates were observed for chlorpyrifos in pore water with high concentrations of DOM. Rate enhancement due to other reactive species (e.g., organo-sulfur compounds) in pore water was minor for both compounds relative to the influence of bisulfide and DOM.

Integrating sentinel watershed-systems into the monitoring and assessment of Minnesota's (USA) waters quality.

PubMed

Magner, J A; Brooks, K N

2008-03-01

Section 303(d) of the Clean Water Act requires States and Tribes to list waters not meeting water quality standards. A total maximum daily load must be prepared for waters identified as impaired with respect to water quality standards. Historically, the management of pollution in Minnesota has been focused on point-source regulation. Regulatory effort in Minnesota has improved water quality over the last three decades. Non-point source pollution has become the largest driver of conventional 303(d) listings in the 21st century. Conventional pollutants, i.e., organic, sediment and nutrient imbalances can be identified with poor land use management practices. However, the cause and effect relationship can be elusive because of natural watershed-system influences that vary with scale. Elucidation is complex because the current water quality standards in Minnesota were designed to work best with water quality permits to control point sources of pollution. This paper presents a sentinel watershed-systems approach (SWSA) to the monitoring and assessment of Minnesota waterbodies. SWSA integrates physical, chemical, and biological data over space and time using advanced technologies at selected small watersheds across Minnesota to potentially improve understanding of natural and anthropogenic watershed processes and the management of point and non-point sources of pollution. Long-term, state-of-the-art monitoring and assessment is needed to advance and improve water quality standards. Advanced water quality or ecologically-based standards that integrate physical, chemical, and biological numeric criteria offer the potential to better understand, manage, protect, and restore Minnesota's waterbodies.

Combination of ray-tracing and the method of moments for electromagnetic radiation analysis using reduced meshes

NASA Astrophysics Data System (ADS)

Delgado, Carlos; Cátedra, Manuel Felipe

2018-05-01

This work presents a technique that allows a very noticeable relaxation of the computational requirements for full-wave electromagnetic simulations based on the Method of Moments. A ray-tracing analysis of the geometry is performed in order to extract the critical points with significant contributions. These points are then used to generate a reduced mesh, considering the regions of the geometry that surround each critical point and taking into account the electrical path followed from the source. The electromagnetic analysis of the reduced mesh produces very accurate results, requiring a fraction of the resources that the conventional analysis would utilize.

Non-contact local temperature measurement inside an object using an infrared point detector

NASA Astrophysics Data System (ADS)

Hisaka, Masaki

2017-04-01

Local temperature measurement in deep areas of objects is an important technique in biomedical measurement. We have investigated a non-contact method for measuring temperature inside an object using a point detector for infrared (IR) light. An IR point detector with a pinhole was constructed and the radiant IR light emitted from the local interior of the object is photodetected only at the position of pinhole located in imaging relation. We measured the thermal structure of the filament inside the miniature bulb using the IR point detector, and investigated the temperature dependence at approximately human body temperature using a glass plate positioned in front of the heat source.

Water-Related Infrastructure in a Region of Post-Earthquake Haiti: High Levels of Fecal Contamination and Need for Ongoing Monitoring

PubMed Central

Widmer, Jocelyn M.; Weppelmann, Thomas A.; Alam, Meer T.; Morrissey, B. David; Redden, Edsel; Rashid, Mohammed H.; Diamond, Ulrica; Ali, Afsar; De Rochars, Madsen Beau; Blackburn, Jason K.; Johnson, Judith A.; Morris, J. Glenn

2014-01-01

We inventoried non-surface water sources in the Leogane and Gressier region of Haiti (approximately 270 km2) in 2012 and 2013 and screened water from 345 sites for fecal coliforms and Vibrio cholerae. An international organization/non-governmental organization responsible for construction could be identified for only 56% of water points evaluated. Sixteen percent of water points were non-functional at any given time; 37% had evidence of fecal contamination, with spatial clustering of contaminated sites. Among improved water sources (76% of sites), 24.6% had fecal coliforms versus 80.9% in unimproved sources. Fecal contamination levels increased significantly from 36% to 51% immediately after the passage of Tropical Storm Sandy in October of 2012, with a return to 34% contamination in March of 2013. Long-term sustainability of potable water delivery at a regional scale requires ongoing assessment of water quality, functionality, and development of community-based management schemes supported by a national plan for the management of potable water. PMID:25071005

Water-related infrastructure in a region of post-earthquake Haiti: high levels of fecal contamination and need for ongoing monitoring.

PubMed

Widmer, Jocelyn M; Weppelmann, Thomas A; Alam, Meer T; Morrissey, B David; Redden, Edsel; Rashid, Mohammed H; Diamond, Ulrica; Ali, Afsar; De Rochars, Madsen Beau; Blackburn, Jason K; Johnson, Judith A; Morris, J Glenn

2014-10-01

We inventoried non-surface water sources in the Leogane and Gressier region of Haiti (approximately 270 km(2)) in 2012 and 2013 and screened water from 345 sites for fecal coliforms and Vibrio cholerae. An international organization/non-governmental organization responsible for construction could be identified for only 56% of water points evaluated. Sixteen percent of water points were non-functional at any given time; 37% had evidence of fecal contamination, with spatial clustering of contaminated sites. Among improved water sources (76% of sites), 24.6% had fecal coliforms versus 80.9% in unimproved sources. Fecal contamination levels increased significantly from 36% to 51% immediately after the passage of Tropical Storm Sandy in October of 2012, with a return to 34% contamination in March of 2013. Long-term sustainability of potable water delivery at a regional scale requires ongoing assessment of water quality, functionality, and development of community-based management schemes supported by a national plan for the management of potable water. © The American Society of Tropical Medicine and Hygiene.

Test method for telescopes using a point source at a finite distance

NASA Technical Reports Server (NTRS)

Griner, D. B.; Zissa, D. E.; Korsch, D.

1985-01-01

A test method for telescopes that makes use of a focused ring formed by an annular aperture when using a point source at a finite distance is evaluated theoretically and experimentally. The results show that the concept can be applied to near-normal, as well as grazing incidence. It is particularly suited for X-ray telescopes because of their intrinsically narrow annular apertures, and because of the largely reduced diffraction effects.

A screening-level modeling approach to estimate nitrogen ...

EPA Pesticide Factsheets

This paper presents a screening-level modeling approach that can be used to rapidly estimate nutrient loading and assess numerical nutrient standard exceedance risk of surface waters leading to potential classification as impaired for designated use. It can also be used to explore best management practice (BMP) implementation to reduce loading. The modeling framework uses a hybrid statistical and process based approach to estimate source of pollutants, their transport and decay in the terrestrial and aquatic parts of watersheds. The framework is developed in the ArcGIS environment and is based on the total maximum daily load (TMDL) balance model. Nitrogen (N) is currently addressed in the framework, referred to as WQM-TMDL-N. Loading for each catchment includes non-point sources (NPS) and point sources (PS). NPS loading is estimated using export coefficient or event mean concentration methods depending on the temporal scales, i.e., annual or daily. Loading from atmospheric deposition is also included. The probability of a nutrient load to exceed a target load is evaluated using probabilistic risk assessment, by including the uncertainty associated with export coefficients of various land uses. The computed risk data can be visualized as spatial maps which show the load exceedance probability for all stream segments. In an application of this modeling approach to the Tippecanoe River watershed in Indiana, USA, total nitrogen (TN) loading and risk of standard exce

Stochastic sensitivity analysis of nitrogen pollution to climate change in a river basin with complex pollution sources.

PubMed

Yang, Xiaoying; Tan, Lit; He, Ruimin; Fu, Guangtao; Ye, Jinyin; Liu, Qun; Wang, Guoqing

2017-12-01

It is increasingly recognized that climate change could impose both direct and indirect impacts on the quality of the water environment. Previous studies have mostly concentrated on evaluating the impacts of climate change on non-point source pollution in agricultural watersheds. Few studies have assessed the impacts of climate change on the water quality of river basins with complex point and non-point pollution sources. In view of the gap, this paper aims to establish a framework for stochastic assessment of the sensitivity of water quality to future climate change in a river basin with complex pollution sources. A sub-daily soil and water assessment tool (SWAT) model was developed to simulate the discharge, transport, and transformation of nitrogen from multiple point and non-point pollution sources in the upper Huai River basin of China. A weather generator was used to produce 50 years of synthetic daily weather data series for all 25 combinations of precipitation (changes by - 10, 0, 10, 20, and 30%) and temperature change (increases by 0, 1, 2, 3, and 4 °C) scenarios. The generated daily rainfall series was disaggregated into the hourly scale and then used to drive the sub-daily SWAT model to simulate the nitrogen cycle under different climate change scenarios. Our results in the study region have indicated that (1) both total nitrogen (TN) loads and concentrations are insensitive to temperature change; (2) TN loads are highly sensitive to precipitation change, while TN concentrations are moderately sensitive; (3) the impacts of climate change on TN concentrations are more spatiotemporally variable than its impacts on TN loads; and (4) wide distributions of TN loads and TN concentrations under individual climate change scenario illustrate the important role of climatic variability in affecting water quality conditions. In summary, the large variability in SWAT simulation results within and between each climate change scenario highlights the uncertainty of the impacts of climate change and the need to incorporate extreme conditions in managing water environment and developing climate change adaptation and mitigation strategies.

Apportioning riverine DIN load to export coefficients of land uses in an urbanized watershed.

PubMed

Shih, Yu-Ting; Lee, Tsung-Yu; Huang, Jr-Chuan; Kao, Shuh-Ji; Chang

2016-08-01

The apportionment of riverine dissolved inorganic nitrogen (DIN) load to individual land use on a watershed scale demands the support of accurate DIN load estimation and differentiation of point and non-point sources, but both of them are rarely quantitatively determined in small montane watersheds. We introduced the Danshui River watershed of Taiwan, a mountainous urbanized watershed, to determine the export coefficients via a reverse Monte Carlo approach from riverine DIN load. The results showed that the dynamics of N fluctuation determines the load estimation method and sampling frequency. On a monthly sampling frequency basis, the average load estimation of the methods (GM, FW, and LI) outperformed that of individual method. Export coefficient analysis showed that the forest DIN yield of 521.5kg-Nkm(-2)yr(-1) was ~2.7-fold higher than the global riverine DIN yield (mainly from temperate large rivers with various land use compositions). Such a high yield was attributable to high rainfall and atmospheric N deposition. The export coefficient of agriculture was disproportionately larger than forest suggesting that a small replacement of forest to agriculture could lead to considerable change of DIN load. The analysis of differentiation between point and non-point sources showed that the untreated wastewater (non-point source), accounting for ~93% of the total human-associated wastewater, resulted in a high export coefficient of urban. The inclusion of the treated and untreated wastewater completes the N budget of wastewater. The export coefficient approach serves well to assess the riverine DIN load and to improve the understanding of N cascade. Copyright © 2016 Elsevier B.V. All rights reserved.

International migration and welfare in the source country.

PubMed

Basu, B; Bhattacharyya, G

1991-12-01

"In a recent paper, Rivera-Batiz (1982) points out that the economic effects of migration should be studied in the presence of non-traded goods in the source country.... We will show that Rivera-Batiz's explanations do not consider all the aspects of ownership and transfer of inputs by migrants. Consequently, we will show that if...additional issues are taken into account, the non-migrants can turn out to be actually better off as a result of emigration." excerpt

High-efficiency non-uniformity correction for wide dynamic linear infrared radiometry system

NASA Astrophysics Data System (ADS)

Li, Zhou; Yu, Yi; Tian, Qi-Jie; Chang, Song-Tao; He, Feng-Yun; Yin, Yan-He; Qiao, Yan-Feng

2017-09-01

Several different integration times are always set for a wide dynamic linear and continuous variable integration time infrared radiometry system, therefore, traditional calibration-based non-uniformity correction (NUC) are usually conducted one by one, and furthermore, several calibration sources required, consequently makes calibration and process of NUC time-consuming. In this paper, the difference of NUC coefficients between different integration times have been discussed, and then a novel NUC method called high-efficiency NUC, which combines the traditional calibration-based non-uniformity correction, has been proposed. It obtains the correction coefficients of all integration times in whole linear dynamic rangesonly by recording three different images of a standard blackbody. Firstly, mathematical procedure of the proposed non-uniformity correction method is validated and then its performance is demonstrated by a 400 mm diameter ground-based infrared radiometry system. Experimental results show that the mean value of Normalized Root Mean Square (NRMS) is reduced from 3.78% to 0.24% by the proposed method. In addition, the results at 4 ms and 70 °C prove that this method has a higher accuracy compared with traditional calibration-based NUC. In the meantime, at other integration time and temperature there is still a good correction effect. Moreover, it greatly reduces the number of correction time and temperature sampling point, and is characterized by good real-time performance and suitable for field measurement.

MODELING MINERAL NITROGEN EXPORT FROM A FOREST TERRESTRIAL ECOSYSTEM TO STREAMS

EPA Science Inventory

Terrestrial ecosystems are major sources of N pollution to aquatic ecosystems. Predicting N export to streams is a critical goal of non-point source modeling. This study was conducted to assess the effect of terrestrial N cycling on stream N export using long-term monitoring da...

Effect of feed source and pyrolysis conditions on properties and metal sorption by sugarcane biochar

USDA-ARS?s Scientific Manuscript database

Population growth along with urbanization expansion and intensification of arable land management burdens natural systems ability to sustain ecosystem services such as clean waters. Development of low-cost sorbents for use in non-point-source runoff-water infiltration systems is essential for improv...

COMPARISON OF OZONE INDICATORS MONITORED AT CASTNET AND RURALLY - DESIGNATED SLAMS SITES

EPA Science Inventory

Many water-bodies within the United States are contaminated by non-point source (NPS) pollution, which is defined as those materials posing a threat to water quality arising from a number of individual sources and diffused through hydrologic 13romses. One such NPS pollutant is fe...

Evaluating the suitability of the Soil Vulnerability Index (SVI) classification scheme using the SWAT model

USDA-ARS?s Scientific Manuscript database

Conservation practices are effective ways to mitigate non-point source pollution, especially when implemented on critical source areas (CSAs) known to be the areas contributing disproportionately to high pollution loads. Although hydrologic models are promising tools to identify CSAs within agricul...

Using high resolution Lidar data from SnowEx to characterize the sensitivity of snow depth retrievals to point-cloud density and vegetation

NASA Astrophysics Data System (ADS)

Patterson, V. M.; Bormann, K.; Deems, J. S.; Painter, T. H.

2017-12-01

The NASA SnowEx campaign conducted in 2016 and 2017 provides a rich source of high-resolution Lidar data from JPL's Airborne Snow Observatory (ASO - http://aso.jpl.nasa.gov) combined with extensive in-situ measurements in two key areas in Colorado: Grand Mesa and Senator Beck. While the uncertainty in the 50m snow depth retrievals from NASA's ASO been estimated at 1-2cm in non-vegetated exposed areas (Painter et al., 2016), the impact of forest cover and point-cloud density on ASO snow lidar depth retrievals is relatively unknown. Dense forest canopies are known to reduce lidar penetration and ground strikes thus affecting the elevation surface retrieved from in the forest. Using high-resolution lidar point cloud data from the ASO SnowEx campaigns (26pt/m2) we applied a series of data decimations (up to 90% point reduction) to the point cloud data to quantify the relationship between vegetation, ground point density, resulting snow-off and snow-on surface elevations and finally snow depth. We observed non-linear reductions in lidar ground point density in forested areas that were strongly correlated to structural forest cover metrics. Previously, the impacts of these data decimations on a small study area in Grand Mesa showed a sharp increase in under-canopy surface elevation errors of -0.18m when ground point densities were reduced to 1.5pt/m2. In this study, we expanded the evaluation to the more topographically challenging Senator Beck basin, have conducted analysis along a vegetation gradient and are considering snow the impacts of snow depth rather than snow-off surface elevation. Preliminary analysis suggest that snow depth retrievals inferred from airborne lidar elevation differentials may systematically underestimate snow depth in forests where canopy density exceeds 1.75 and where tree heights exceed 5m. These results provide a basis from which to identify areas that may suffer from vegetation-induced biases in surface elevation models and snow depths derived from airborne lidar data, and help quantify expected spatial distributions of errors in the snow depth that can be used to improve the accuracy of ASO basin-scale depth and water equivalent products.

Evaluating watershed protection programs in New York City's Cannonsville Reservoir source watershed using SWAT-HS

NASA Astrophysics Data System (ADS)

Hoang, L.; Mukundan, R.; Moore, K. E.; Owens, E. M.; Steenhuis, T. S.

2017-12-01

New York City (NYC)'s reservoirs supply over one billion gallons of drinking water each day to over nine million consumers in NYC and upstate communities. The City has invested more than $1.5 billion in watershed protection programs to maintain a waiver from filtration for the Catskill and Delaware Systems. In the last 25 years, the NYC Department of Environmental Protection (NYCDEP) has implemented programs in cooperation with upstate communities that include nutrient management, crop rotations, improvement of barnyards and manure storage, implementing tertiary treatment for Phosphorus (P) in wastewater treatment plants, and replacing failed septic systems in an effort to reduce P loads to water supply reservoirs. There have been several modeling studies evaluating the effect of agricultural Best Management Practices (BMPs) on P control in the Cannonsville watershed in the Delaware System. Although these studies showed that BMPs would reduce dissolved P losses, they were limited to farm-scale or watershed-scale estimates of reduction factors without consideration of the dynamic nature of overland flow and P losses from variable source areas. Recently, we developed the process-based SWAT-Hillslope (SWAT-HS) model, a modified version of the Soil and Water Assessment Tool (SWAT) that can realistically predict variable source runoff processes. The objective of this study is to use the SWAT-HS model to evaluate watershed protection programs addressing both point and non-point sources of P. SWAT-HS predicts streamflow very well for the Cannonsville watershed with a daily Nash Sutcliffe Efficiency (NSE) of 0.85 at the watershed outlet and NSE values ranging from 0.56 - 0.82 at five other locations within the watershed. Based on good hydrological prediction, we applied the model to predict P loads using detailed P inputs that change over time due to the implementation of watershed protection programs. Results from P model predictions provide improved projections of P loads and form a basis for evaluating the cumulative and individual effects of watershed protection programs.

Analysis of the environmental behavior of farmers for non-point source pollution control and management in a water source protection area in China.

PubMed

Wang, Yandong; Yang, Jun; Liang, Jiping; Qiang, Yanfang; Fang, Shanqi; Gao, Minxue; Fan, Xiaoyu; Yang, Gaihe; Zhang, Baowen; Feng, Yongzhong

2018-08-15

The environmental behavior of farmers plays an important role in exploring the causes of non-point source pollution and taking scientific control and management measures. Based on the theory of planned behavior (TPB), the present study investigated the environmental behavior of farmers in the Water Source Area of the Middle Route of the South-to-North Water Diversion Project in China. Results showed that TPB could explain farmers' environmental behavior (SMC=0.26) and intention (SMC=0.36) well. Furthermore, the farmers' attitude towards behavior (AB), subjective norm (SN), and perceived behavioral control (PBC) positively and significantly influenced their environmental intention; their environmental intention further impacted their behavior. SN was proved to be the main key factor indirectly influencing the farmers' environmental behavior, while PBC had no significant and direct effect. Moreover, environmental knowledge following as a moderator, gender and age was used as control variables to conduct the environmental knowledge on TPB construct moderated mediation analysis. It demonstrated that gender had a significant controlling effect on environmental behavior; that is, males engage in more environmentally friendly behaviors. However, age showed a significant negative controlling effect on pro-environmental intention and an opposite effect on pro-environmental behavior. In addition, environmental knowledge could negatively moderate the relationship between PBC and environmental intention. PBC had a greater impact on the environmental intention of farmers with poor environmental knowledge, compared to those with plenty environmental knowledge. Altogether, the present study could provide a theoretical basis for non-point source pollution control and management. Copyright © 2018 Elsevier B.V. All rights reserved.

Scenario Tools For Efficient Eutrophication Management

NASA Astrophysics Data System (ADS)

Arheimer, B.; Vastra SP3 Team

Several possible measures are available to reduce diffuse (non-point source) nutri- ent load to surface water and thereby reduce eutrophication. Such measures include changed arable practices and constructions of wetlands and buffer zones in the land- scape, as well as managing lake ecosystems. In some cases, such as for wetlands, there is an intense debate regarding the efficiency of their nutrient reducing capability. In ad- dition, the combined effect of several measures in a catchment is not necessarily equal to their sum. It is therefore important to apply a holistic and integrated catchment approach when applying and evaluating different management strategies. To facili- tate such catchment analyses, the Swedish water management research programme (VASTRA) develop modelling tools addressing both phosphorus (P) and nitrogen (N) dynamics in catchments. During the last three years decision support tools for N man- agement in rivers and lakes have been developed (e.g., HBV-N, BIOLA) and applied in scenarios to demonstrate the effect of various reducing measures. At present, similar tools for P are under development. This presentation will demonstrate the VASTRA tool-box and its applications for efficient eutrophication management.

A review of vegetated buffers and a meta-analysis of their mitigation efficacy in reducing non-point source pollution

NASA Astrophysics Data System (ADS)

Zhang, X.; Liu, X.; Zhang, M.; Dahlgren, R. A.; Eitzel, M.

2009-12-01

Vegetated buffers are a well-studied and widely used agricultural management practice for reducing non-point source pollution. A wealth of literature provides experimental data on their mitigation efficacy. This paper aggregated many of these results and performed a meta-analysis to quantify the relationships between pollutant removal efficacy and buffer width, buffer slope, soil type, and vegetation type. Theoretical models for removal efficacy (Y) vs. buffer width (w) were derived and tested against data from the surveyed literature using statistical analyses. A model of the form Y = K x (1-exp(-b x w) , (0< K <= 100) successfully captured the relationship between buffer width and pollutant removal, where K reflects the maximum removal efficacy of the buffer and b reflects its probability to remove any single particle of pollutant in a unit distance. The estimates of K were 90.9, 93.2, 92.0, and 89.5 for sediment, pesticides, nitrogen (N) and phosphorus (P), respectively. Buffer width alone explains 37, 60, 44 and 35% of the total variance in removal efficacy for sediment, pesticides, N and P, respectively. Buffer slope was linearly associated with sediment removal efficacy either positively (when slope ≤ 10%) or negatively (when slope > 10%). Buffers composed of trees have higher N and P removal efficacy than buffers composed of grasses or mixtures of grasses and trees. Soil drainage type did not show a significant effect on pollutant removal efficacy. Models for all the studied pollutants were statistically significant with P-values < 0.001. Based on our analysis, a 30 m buffer under favorable slope conditions (≈ 10%) removes over 85% of all the studied pollutants. These models predicting optimal buffer width/slope can be instrumental in the design, implementation and modeling of vegetated buffers for treating agricultural runoff.

Incorporation of Complex Hydrological and Socio-economic Factors for Non-point Source Pollution Control: A Case Study at the Yincungang Canal, the Lake Tai Basin of China

NASA Astrophysics Data System (ADS)

Yang, X.; Luo, X.; Zheng, Z.

2012-04-01

It is increasingly realized that non-point pollution sources contribute significantly to water environment deterioration in China. Compared to developed countries, non-point source pollution in China has the unique characteristics of strong intensity and composition complexity due to its special socioeconomic conditions. First, more than 50% of its 1.3 billion people are rural. Sewage from the majority of the rural households is discharged either without or only with minimal treatment. The large amount of erratic rural sewage discharge is a significant source of water pollution. Second, China is plagued with serious agricultural pollution due to widespread improper application of fertilizers and pesticides. Finally, there lack sufficient disposal and recycling of rural wastes such as livestock manure and crop straws. Pollutant loads from various sources have far exceeded environmental assimilation capacity in many parts of China. The Lake Tai basin is one typical example. Lake Tai is the third largest freshwater lake in China. The basin is located in the highly developed and densely populated Yangtze River Delta. While accounting for 0.4% of its land area and 2.9% of its population, the Lake Tai basin generates more than 14% of China's Gross Domestic Production (GDP), and the basin's GDP per capita is 3.5 times as much as the state average. Lake Tai is vital to the basin's socio-economic development, providing multiple services including water supply for municipal, industrial, and agricultural needs, navigation, flood control, fishery, and tourism. Unfortunately, accompanied with the fast economic development is serious water environment deterioration in the Lake Tai basin. The lake is becoming increasingly eutrophied and has frequently suffered from cyanobacterial blooms in recent decades. Chinese government has made tremendous investment in order to mitigate water pollution conditions in the basin. Nevertheless, the trend of deteriorating water quality has yet to be reversed. At least two factors contribute to the dichotomy between huge investment and limited results. First, the majority of the efforts have been limited to engineering approaches to water pollution control, ignoring the important roles of non-engineering approaches and stakeholder participation. Second, the complex hydrological regime of the basin may aggravate the impacts of various pollutant sources. Using the Yincungang canal, one major tributary to the Lake Tai, as an example, we discuss our work on both hydrological and socio-economic factors affecting the water quality of the canal, as well as the grand challenges of coupling hydrological systems and socio-economic systems in the region. Keywords non-point source pollution, rural sewage, agricultural pollution, spatio-temporal pattern, stakeholder participation

Runoff characteristics and non-point source pollution analysis in the Taihu Lake Basin: a case study of the town of Xueyan, China.

PubMed

Zhu, Q D; Sun, J H; Hua, G F; Wang, J H; Wang, H

2015-10-01

Non-point source pollution is a significant environmental issue in small watersheds in China. To study the effects of rainfall on pollutants transported by runoff, rainfall was monitored in Xueyan town in the Taihu Lake Basin (TLB) for over 12 consecutive months. The concentrations of different forms of nitrogen (N) and phosphorus (P), and chemical oxygen demand, were monitored in runoff and river water across different land use types. The results indicated that pollutant loads were highly variable. Most N losses due to runoff were found around industrial areas (printing factories), while residential areas exhibited the lowest nitrogen losses through runoff. Nitrate nitrogen (NO3-N) and ammonia nitrogen (NH4-N) were the dominant forms of soluble N around printing factories and hotels, respectively. The levels of N in river water were stable prior to the generation of runoff from a rainfall event, after which they were positively correlated to rainfall intensity. In addition, three sites with different areas were selected for a case study to analyze trends in pollutant levels during two rainfall events, using the AnnAGNPS model. The modeled results generally agreed with the observed data, which suggests that AnnAGNPS can be used successfully for modeling runoff nutrient loading in this region. The conclusions of this study provide important information on controlling non-point source pollution in TLB.

Applying the Manning equation to determine the critical distance in non-point source pollution using remotely sensed data and cartographic modelling

NASA Astrophysics Data System (ADS)

de Oliveira, Lília M.; Santos, Nádia A. P.; Maillard, Philippe

2013-10-01

Non-point source pollution (NPSP) is perhaps the leading cause of water quality problems and one of the most challenging environmental issues given the difficulty of modeling and controlling it. In this article, we applied the Manning equation, a hydraulic concept, to improve models of non-point source pollution and determine its influence as a function of slope - land cover roughness for runoff to reach the stream. In our study the equation is somewhat taken out of its usual context to be applies to the flow of an entire watershed. Here a digital elevation model (DEM) from the SRTM satellite was used to compute the slope and data from the RapidEye satellite constellation was used to produce a land cover map later transformed into a roughness surface. The methodology is applied to a 1433 km2 watershed in Southeast Brazil mostly covered by forest, pasture, urban and wetlands. The model was used to create slope buffer of varying width in which the proportions of land cover and roughness coefficient were obtained. Next we correlated these data, through regression, with four water quality parameters measured in situ: nitrate, phosphorous, faecal coliform and turbidity. We compare our results with the ones obtained by fixed buffer. It was found that slope buffer outperformed fixed buffer with higher coefficients of determination up to 15%.

Methane - quick fix or tough target? New methods to reduce emissions.

NASA Astrophysics Data System (ADS)

Nisbet, E. G.; Lowry, D.; Fisher, R. E.; Brownlow, R.

2016-12-01

Methane is a cost-effective target for greenhouse gas reduction efforts. The UK's MOYA project is designed to improve understanding of the global methane budget and to point to new methods to reduce future emissions. Since 2007, methane has been increasing rapidly: in 2014 and 2015 growth was at rates last seen in the 1980s. Unlike 20thcentury growth, primarily driven by fossil fuel emissions in northern industrial nations, isotopic evidence implies present growth is driven by tropical biogenic sources such as wetlands and agriculture. Discovering why methane is rising is important. Schaefer et al. (Science, 2016) pointed out the potential clash between methane reduction efforts and food needs of a rising, better-fed (physically larger) human population. Our own work suggests tropical wetlands are major drivers of growth, responding to weather changes since 2007, but there is no acceptable way to reduce wetland emission. Just as sea ice decline indicates Arctic warming, methane may be the most obvious tracker of climate change in the wet tropics. Technical advances in instrumentation can do much in helping cut urban and industrial methane emissions. Mobile systems can be mounted on vehicles, while drone sampling can provide a 3D view to locate sources. Urban land planning often means large but different point sources are typically clustered (e.g. landfill or sewage plant near incinerator; gas wells next to cattle). High-precision grab-sample isotopic characterisation, using Keeling plots, can separate source signals, to identify specific emitters, even where they are closely juxtaposed. Our mobile campaigns in the UK, Kuwait, Hong Kong and E. Australia show the importance of major single sources, such as abandoned old wells, pipe leaks, or unregulated landfills. If such point sources can be individually identified, even when clustered, they will allow effective reduction efforts to occur: these can be profitable and/or improve industrial safety, for example in the case of gas leaks. Fossil fuels, landfills, waste, and biomass burning emit about 200 Tg/yr, or 35-40% of global methane emissions. Using inexpensive 3D mobile surveys coupled with high-precision isotopic measurement, it should be possible to cut emissions sharply, substantially reducing the methane burden even if tropical biogenic sources increase.

STORAGE DURATION AND TEMPERATURE AND THE ACUTE TOXICITIES OF ESTUARINE SEDIMENTS TO MYSIDOPSIS BAHIA AND LEPTOCHEIRUS PLUMULOSUS.

EPA Science Inventory

Many statutory needs for sediment quality assessment exist (U.S. EPA 1996). A variety of sediment toxicity tests have been used to support the development of sediment quality guidelines and to determine the benthic impacts of dredging activities and point and non-point source tox...

STORAGE DURATION AND TEMPERATURE AND THE ACUTE TOXICITIES OF ESTUARINE SEDIMENTS TO MYSIDOPSIS BAHIA AND LEPTOCHEIRUS PLUMULOSUS

EPA Science Inventory

Many statutory needs for sediment quality assessment exist (U.S. EPA 1996). A variety of sediment toxicity tests have been used to support the development of sediment quality guidelines and to determine the benthic impacts of dredging activities and point and non-point source tox...

A repeated-measures study of recreational water exposure, non-point source pollution, and risk of illness

EPA Science Inventory

Discharge of stormwater runoff onto beaches is a major cause of beach closings and advisories in the United States. Prospective studies of recreational water quality and health have often been limited to two time points (baseline and follow-up). Little is known about the risk of ...

Nakedly singular non-vacuum gravitating equilibrium states

NASA Astrophysics Data System (ADS)

Woszczyna, Andrzej; Kutschera, Marek; Kubis, Sebastian; Czaja, Wojciech; Plaszczyk, Piotr; Golda, Zdzisław A.

2016-01-01

Non-vacuum static spherically symmetric spacetimes with central point-like repulsive gravity sources are investigated. Both the symmetries of spacetime and the degree of irregularity of curvature invariants, are the same as for the Schwarzschild case. The equilibrium configurations are modelled using the neutron star polytrope equation of state.

40 CFR 425.30 - Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Applicability; description of the hair... TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome Tan, Retan-Wet Finish Subcategory § 425.30 Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish...

40 CFR 425.30 - Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Applicability; description of the hair... TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome Tan, Retan-Wet Finish Subcategory § 425.30 Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish...

40 CFR 425.30 - Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Applicability; description of the hair... FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome Tan, Retan-Wet Finish Subcategory § 425.30 Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory. The...

40 CFR 425.30 - Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Applicability; description of the hair... TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save or Pulp, Non-Chrome Tan, Retan-Wet Finish Subcategory § 425.30 Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish...

Indicator microbes correlate with pathogenic bacteria, yeasts and helminthes in sand at a subtropical recreational beach site.

PubMed

Shah, A H; Abdelzaher, A M; Phillips, M; Hernandez, R; Solo-Gabriele, H M; Kish, J; Scorzetti, G; Fell, J W; Diaz, M R; Scott, T M; Lukasik, J; Harwood, V J; McQuaig, S; Sinigalliano, C D; Gidley, M L; Wanless, D; Ager, A; Lui, J; Stewart, J R; Plano, L R W; Fleming, L E

2011-06-01

Research into the relationship between pathogens, faecal indicator microbes and environmental factors in beach sand has been limited, yet vital to the understanding of the microbial relationship between sand and the water column and to the improvement of criteria for better human health protection at beaches. The objectives of this study were to evaluate the presence and distribution of pathogens in various zones of beach sand (subtidal, intertidal and supratidal) and to assess their relationship with environmental parameters and indicator microbes at a non-point source subtropical marine beach. In this exploratory study in subtropical Miami (Florida, USA), beach sand samples were collected and analysed over the course of 6 days for several pathogens, microbial source tracking markers and indicator microbes. An inverse correlation between moisture content and most indicator microbes was found. Significant associations were identified between some indicator microbes and pathogens (such as nematode larvae and yeasts in the genus Candida), which are from classes of microbes that are rarely evaluated in the context of recreational beach use. Results indicate that indicator microbes may predict the presence of some of the pathogens, in particular helminthes, yeasts and the bacterial pathogen Staphylococcus aureus including methicillin-resistant forms. Indicator microbes may thus be useful for monitoring beach sand and water quality at non-point source beaches. The presence of both indicator microbes and pathogens in beach sand provides one possible explanation for human health effects reported at non-point sources beaches. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

Meat sources of infection for outbreaks of human trichinellosis.

PubMed

Rostami, Ali; Gamble, H Ray; Dupouy-Camet, Jean; Khazan, Hooshang; Bruschi, Fabrizio

2017-06-01

Trichinellosis is one of the most important foodborne zoonotic diseases, with worldwide distribution. While human risk for trichinellosis has historically been linked to pork, modern pork production systems and slaughter inspection programs have reduced or eliminated pork as a source for trichinellosis in many countries. While pork may no longer pose a significant risk for trichinellosis, many other animal species may be hosts for Trichinella species nematodes and when human consume meat from these animal species, there may be risk for acquiring trichinellosis. This review article describes the various non-pork meat sources of human trichinellosis outbreaks, where these outbreaks have occurred and some of the factors that contribute to human risk. The literature reviewed here provides evidence of the persistence of Trichinella as a human health risk for people who eat meat from feral and wild carnivores and scavengers, as well as some herbivores that have been shown to harbor Trichinella larvae. It points to the importance of education of hunters and consumers of these meats and meat products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Applications of remote sensing to hydrologic planning

NASA Technical Reports Server (NTRS)

Loats, H., Jr.; Fowler, T.; Castruccio, P.

1978-01-01

The transfer of LANDSAT remote sensing technology from the research sector to user operational applications requires demonstration of the utility and accuracy of LANDSAT data in solving real problems. This report describes such a demonstration project in the area of water resources, specifically the estimation of non-point source pollutant loads. Non-point source pollutants were estimated from land cover data from LANDSAT images. Classification accuracies for three small watersheds were above 95%. Land cover was converted to pollutant loads for a fourth watershed through the use of coefficients relating significant pollutants to land use and storm runoff volume. These data were input into a simulator model which simulated runoff from average rainfall. The result was the estimation of monthly expected pollutant loads for the 17 subbasins comprising the Magothy watershed.

On the Transportability of Ms Versus Yield Relationships

NASA Astrophysics Data System (ADS)

Patton, H. J.; Randall, G. E.

2014-12-01

A physical basis for transporting magnitude (M) versus yield (W) relationships between test sites is essential for improved yield estimation. A case in point is an Ms relationship transported from the Nevada Test Site, which gives W estimates of North Korean tests roughly a factor of two larger than mb-based estimates. In order to test the performance of this relation, we transport it to Semipalatinsk (STS) where W and source media information are available. The transported Ms - W relation was developed for water-saturated tuff/rhyolite, and Rayleigh-wave generation was corrected for the effects of source medium compaction due to spall slapdown. Coupling variations with burial depth and the effects of compaction, both functions of W in tuff/rhyolite, are mitigated for shots in hard rock. As such, it is satisfying that Ms for STS shots are seen to scale similarly as the transported relation, ~0.8log[W]. However, they are offset downward by 0.4 - 0.5 magnitude units. A negative offset is consistent with the effects of tectonic release, but research has shown the inadequacy of double-couple (DC) mechanisms to improve correlations of moment magnitude Mw - W relations. Source medium properties are not a factor because larger amplitude Green's functions in weak rock trade off with reduced source strength relative to explosions in hard rock. In this paper, the role of late-time damage due to non-linear, free-surface interactions, modeled with an Mzz source, is explored. Combining this source with DC mechanisms, we show the non-uniqueness of models to satisfy long-period surface-wave observations, and investigate overcoming this difficulty with full waveform modeling of Borovoye seismograms.

An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils.

PubMed

Huang, Ying; Li, Tingqiang; Wu, Chengxian; He, Zhenli; Japenga, Jan; Deng, Meihua; Yang, Xiaoe

2015-12-15

Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74-100% and 0-24% of the total Hg input, while road dusts and solid wastes contributed for 0-80% and 19-100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions. Copyright © 2015 Elsevier B.V. All rights reserved.

Putting sex education in its place.

PubMed

Cassell, C

1981-04-01

In order to help reduce fears and anxieties regarding the influence of sex education in a public school setting, school and community sexuality educators need to better articulate the difference between formal and structured sex education and non-formal, informal and incidental sex learning. Sex education is only 1 aspect of the sexual learning process. 2 main points have to be clarified for parents and the general public to set the stage for a new way to view the school and community involvement in the sexual learning process: the schools' sexuality education courses constitute only a small portion of the sexual learning process; and sexual learning is not an event for youth only, but a process spanning life. Sex education (the process) connotates an academic setting with a specific curricula taught by a trained instructor, but sexual learning relates to environmental, non-formal incidental learning from a multitude of sources. Studies indicate that teenagers receive about 90% of their contraceptive and sexuality informaation from peers and mass media and that these sources of information are becoming their preferred sources of sex education. What is needed is a way to address and improve the conditions of sexual learning in the community. As home is the ideal environment for primary and positive sexual learning, parents need support in their role as sex educators. Classroom sexuality education curricula in all school settings have a solid place in the process of sexual learning.

Preliminary study on using rare earth elements to trace non-point source phosphorous loss

USDA-ARS?s Scientific Manuscript database

The environmental fate of phosphorus (P) is of concern as P is a primary cause of freshwater eutrophication. Rare earth elements (REEs) have been successfully used in the analysis of soil erosion and pollutant sources, as well as in the analysis of mineral genesis. To better understand the potential...

Examining trends in general fecal indicator bacteria and microbial source tracking genetic markers at non-point source impacted Chicago beaches

EPA Science Inventory

In the Chicago area, treated wastewater and storm water flow through the engineered Chicago River system to the Mississippi River, with the goal to protect Lake Michigan from urban discharges. Therefore, under dry weather conditions, nearby Lake Michigan recreational beaches shou...

[Analysis on nitrogen and phosphorus loading of non-point sources in Shiqiao river watershed based on L-THIA model].

PubMed

Li, Kai; Zeng, Fan-Tang; Fang, Huai-Yang; Lin, Shu

2013-11-01

Based on the Long-term Hydrological Impact Assessment (L-THIA) model, the effect of land use and rainfall change on nitrogen and phosphorus loading of non-point sources in Shiqiao river watershed was analyzed. The parameters in L-THIA model were revised according to the data recorded in the scene of runoff plots, which were set up in the watershed. The results showed that the distribution of areas with high pollution load was mainly concentrated in agricultural land and urban land. Agricultural land was the biggest contributor to nitrogen and phosphorus load. From 1995 to 2010, the load of major pollutants, namely TN and TP, showed an obviously increasing trend with increase rates of 17.91% and 25.30%, respectively. With the urbanization in the watershed, urban land increased rapidly and its area proportion reached 43.94%. The contribution of urban land to nitrogen and phosphorus load was over 40% in 2010. This was the main reason why pollution load still increased obviously while the agricultural land decreased greatly in the past 15 years. The rainfall occurred in the watershed was mainly concentrated in the flood season, so the nitrogen and phosphorus load of the flood season was far higher than that of the non-flood season and the proportion accounting for the whole year was over 85%. Pearson regression analysis between pollution load and the frequency of different patterns of rainfall demonstrated that rainfall exceeding 20 mm in a day was the main rainfall type causing non-point source pollution.

NPTFit: A Code Package for Non-Poissonian Template Fitting

NASA Astrophysics Data System (ADS)

Mishra-Sharma, Siddharth; Rodd, Nicholas L.; Safdi, Benjamin R.

2017-06-01

We present NPTFit, an open-source code package, written in Python and Cython, for performing non-Poissonian template fits (NPTFs). The NPTF is a recently developed statistical procedure for characterizing the contribution of unresolved point sources (PSs) to astrophysical data sets. The NPTF was first applied to Fermi gamma-ray data to provide evidence that the excess of ˜GeV gamma-rays observed in the inner regions of the Milky Way likely arises from a population of sub-threshold point sources, and the NPTF has since found additional applications studying sub-threshold extragalactic sources at high Galactic latitudes. The NPTF generalizes traditional astrophysical template fits to allow for the ability to search for populations of unresolved PSs that may follow a given spatial distribution. NPTFit builds upon the framework of the fluctuation analyses developed in X-ray astronomy, thus it likely has applications beyond those demonstrated with gamma-ray data. The NPTFit package utilizes novel computational methods to perform the NPTF efficiently. The code is available at http://github.com/bsafdi/NPTFit and up-to-date and extensive documentation may be found at http://nptfit.readthedocs.io.

Differentiation of fecal Escherichia coli from poultry and free-living birds by (GTG)5-PCR genomic fingerprinting.

PubMed

Mohapatra, Bidyut R; Broersma, Klaas; Mazumder, Asit

2008-04-01

Determination of the non-point sources of fecal pollution is essential for the assessment of potential public health risk and development of appropriate management practices for prevention of further contamination. Repetitive extragenic palindromic-PCR coupled with (GTG)(5) primer [(GTG)(5)-PCR] was performed on 573 Escherichia coli isolates obtained from the feces of poultry (chicken, duck and turkey) and free-living (Canada goose, hawk, magpie, seagull and songbird) birds to evaluate the efficacy of (GTG)(5)-PCR genomic fingerprinting in the prediction of the correct source of fecal pollution. A discriminant analysis with the jack-knife algorithm of (GTG)(5)-PCR DNA fingerprints revealed that 95%, 94.1%, 93.2%, 84.6%, 79.7%, 76.7%, 75.3% and 70.7% of magpie, hawk, turkey, seagull, Canada goose, chicken, duck and songbird fecal E. coli isolates classified into the correct host source, respectively. The results of this study indicate that (GTG)(5)-PCR can be considered to be a complementary molecular tool for the rapid determination of E. coli isolates identity and tracking the non-point sources of fecal pollution.

Does the finite size of the proto-neutron star preclude supernova neutrino flavor scintillation due to turbulence?

DOE PAGES

Kneller, James P.; Mauney, Alex W.

2013-08-23

Here, the transition probabilities describing the evolution of a neutrino with a given energy along some ray through a turbulent supernova profile are random variates unique to each ray. If the proto-neutron-star source of the neutrinos were a point, then one might expect the evolution of the turbulence would cause the flavor composition of the neutrinos to vary in time i.e. the flavor would scintillate. But in reality the proto-neutron star is not a point source—it has a size of order ˜10km, so the neutrinos emitted from different points at the source will each have seen different turbulence. The finitemore » source size will reduce the correlation of the flavor transition probabilities along different trajectories and reduce the magnitude of the flavor scintillation. To determine whether the finite size of the proto-neutron star will preclude flavor scintillation, we calculate the correlation of the neutrino flavor transition probabilities through turbulent supernova profiles as a function of the separation δx between the emission points. The correlation will depend upon the power spectrum used for the turbulence, and we consider two cases: when the power spectrum is isotropic, and the more realistic case of a power spectrum which is anisotropic on large scales and isotropic on small. Although it is dependent on a number of uncalibrated parameters, we show the supernova neutrino source is not of sufficient size to significantly blur flavor scintillation in all mixing channels when using an isotropic spectrum, and this same result holds when using an anisotropic spectrum, except when we greatly reduce the similarity of the turbulence along parallel trajectories separated by ˜10km or less.« less

Compliance Groundwater Monitoring of Nonpoint Sources - Emerging Approaches

NASA Astrophysics Data System (ADS)

Harter, T.

2008-12-01

Groundwater monitoring networks are typically designed for regulatory compliance of discharges from industrial sites. There, the quality of first encountered (shallow-most) groundwater is of key importance. Network design criteria have been developed for purposes of determining whether an actual or potential, permitted or incidental waste discharge has had or will have a degrading effect on groundwater quality. The fundamental underlying paradigm is that such discharge (if it occurs) will form a distinct contamination plume. Networks that guide (post-contamination) mitigation efforts are designed to capture the shape and dynamics of existing, finite-scale plumes. In general, these networks extend over areas less than one to ten hectare. In recent years, regulatory programs such as the EU Nitrate Directive and the U.S. Clean Water Act have forced regulatory agencies to also control groundwater contamination from non-incidental, recharging, non-point sources, particularly agricultural sources (fertilizer, pesticides, animal waste application, biosolids application). Sources and contamination from these sources can stretch over several tens, hundreds, or even thousands of square kilometers with no distinct plumes. A key question in implementing monitoring programs at the local, regional, and national level is, whether groundwater monitoring can be effectively used as a landowner compliance tool, as is currently done at point-source sites. We compare the efficiency of such traditional site-specific compliance networks in nonpoint source regulation with various designs of regional nonpoint source monitoring networks that could be used for compliance monitoring. We discuss advantages and disadvantages of the site vs. regional monitoring approaches with respect to effectively protecting groundwater resources impacted by nonpoint sources: Site-networks provide a tool to enforce compliance by an individual landowner. But the nonpoint source character of the contamination and its typically large spatial extend requires extensive networks at an individual site to accurately and fairly monitor individual compliance. In contrast, regional networks seemingly fail to hold individual landowners accountable. But regional networks can effectively monitor large-scale impacts and water quality trends; and thus inform regulatory programs that enforce management practices tied to nonpoint source pollution. Regional monitoring networks for compliance purposes can face significant challenges in the implementation due to a regulatory and legal landscape that is exclusively structured to address point sources and individual liability, and due to the non-intensive nature of a regional monitoring program (lack of control of hot spots; lack of accountability of individual landowners).

Natural and Anthropogenic Water Treatment: How Riverine Ecosystem Services of Nitrogen Removal Interact with Wastewater Treatment Infrastructure in the Northeast U.S.

NASA Astrophysics Data System (ADS)

Stewart, R. J.; Wollheim, W. M.; Whittinghill, K. A.; Mineau, M.; Rosenzweig, B.

2014-12-01

The magnitude and spatial distribution of point and non-point dissolved inorganic nitrogen (N) inputs to river systems greatly influences the potential for eutrophication of downstream water bodies. Wastewater treatment plants (WWTPs), the predominant point source of N in the northeast US, remove some but not all of human waste N they receive. Excess enters rivers, which may further mitigate N concentrations by dilution and denitrification. WWTP effluent combines with upstream flows, which may include non-point sources of N due to agriculture or urbanization. Natural N removal capacities in rivers may however be overwhelmed and become N saturated, which reduces their effectiveness. As a result, natural and man-made services of N removal are intimately linked at the river network scale for provisions of suitable water quality and aquatic habitat. We assessed the summer N mitigation capacity of rivers relative to N removal in WWTPs in the northeastern U.S. using a N removal model developed within the Framework for Aquatic Modeling in the Earth System (FrAMES). The spatially distributed river network model predicts average daily dissolved inorganic nitrogen concentrations at a 3-minute river grid resolution, accounting for the mixing of natural areas, nonpoint sources, WWTP effluent, and instream denitrification, which is simulated as a function of river temperature, water residence time, and biogeochemical activity. Model validation was done using N concentration data from 750 USGS gauges across the northeast during the period 2000-2010. Confidence intervals (90%) are estimated for river N concentrations based on key uncertainties in simulated river width, uptake rates, and N loading rates. Model results suggest WWTPs potentially impact 25,770 km of river length (10.7% of total river length in the northeast) and increase N concentrations an average of 42.3% at the facility locations. The in-stream ecosystem service of N removal accounts for 2.7% of the total cumulative N removed by WWTPs during the summer in the region. Despite providing a relatively small proportion of N removal, the expected deterioration of WWTP infrastructure and associated costs of upgrading existing systems puts the role of this riverine ecosystem service into economic perspective.

Preliminary assessment of the occurrence and possible sources of MTBE in groundwater in the United States, 1993-1994

USGS Publications Warehouse

Squillace, P.J.; Zogorski, J.S.; Wilber, W.G.; Price, C.V.

1996-01-01

The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concentrations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE) is the most commonly used fuel oxygenate and is a relatively new gasoline additive. Nevertheless, out of 60 volatile organic chemicals analyzed, MTBE was the second most frequently detected chemical in samples of shallow ambient groundwater from urban areas that were collected during 1993-1994 aspart of the U.S. Geological Survey's National Water-Quality Assessment program. Samples were collected from five drinking water wells, 12 springs, and 193 monitoring wells in urban areas. No MTBE was detected in drinking water wells. At a reporting level of 0.2 ??g/L, MTBE was detected most frequently in shallow groundwater from urban areas (27% of 210 wells and springs sampled in eight areas) as compared to shallow groundwater from agricultural areas (1.3% of 549 wells sampled in 21 areas) or deeper groundwater from major aquifers (1.0% of 412 wells sampled in nine areas). Only 3% of the shallow wells sampled in urban areas had concentrations of MTBE that exceed 20 ??g/L, which is the estimated lower limit of the United States Environmental Protection Agency draft drinking water health advisory. Because MTBE is persistent and mobile in groundwater, it can move from shallow to deeper aquifers with time. In shallow urban groundwater, MTBE generally was not found with benzene, toluene, ethylbenzene, or xylene (BTEX) compounds, which commonly are associated with gasoline spills. This disassociation causes uncertainty as to the source of MTBE. Possible sources of MTBE in groundwater include point sources, such as leaking storage tanks, and non-point sources, such as recharge of precipitation and stormwater runoff.

A human health assessment of hazardous air pollutants in Portland, OR.

PubMed

Tam, B N; Neumann, C M

2004-11-01

Ambient air samples collected from five monitoring sites in Portland, OR during July 1999 to August 2000 were analyzed for 43 hazardous air pollutants (HAP). HAP concentrations were compared to carcinogenic and non-carcinogenic benchmark levels. Carcinogenic benchmark concentrations were set at a risk level of one-in-one-million (1x10(-6)). Hazard ratios of 1.0 were used when comparing HAP concentrations to non-carcinogenic benchmarks. Emission sources (point, area, and mobile) were identified and a cumulative cancer risk and total hazard index were calculated for HAPs exceeding these health benchmark levels. Seventeen HAPs exceeded a cancer risk level of 1x10(-6) at all five monitoring sites. Nineteen HAPs exceeded this level at one or more site. Carbon tetrachloride, 1,3-butadiene, formaldehyde, and 1,1,2,2-tetrachloroethane contributed more than 50% to the upper-bound lifetime cumulative cancer risk of 2.47x10(-4). Acrolein was the only non-carcinogenic HAP with hazard ratios that exceeded 1.0 at all five sites. Mobile sources contributed the greatest percentage (68%) of HAP emissions. Additional monitoring and health assessments for HAPs in Portland, OR are warranted, including addressing issues that may have overestimated or underestimated risks in this study. Abatement strategies for HAPs that exceeded health benchmarks should be implemented to reduce potential adverse health risks.

Concentrator optical characterization using computer mathematical modelling and point source testing

NASA Technical Reports Server (NTRS)

Dennison, E. W.; John, S. L.; Trentelman, G. F.

1984-01-01

The optical characteristics of a paraboloidal solar concentrator are analyzed using the intercept factor curve (a format for image data) to describe the results of a mathematical model and to represent reduced data from experimental testing. This procedure makes it possible not only to test an assembled concentrator, but also to evaluate single optical panels or to conduct non-solar tests of an assembled concentrator. The use of three-dimensional ray tracing computer programs to calculate the mathematical model is described. These ray tracing programs can include any type of optical configuration from simple paraboloids to array of spherical facets and can be adapted to microcomputers or larger computers, which can graphically display real-time comparison of calculated and measured data.

Desensitized Optimal Filtering and Sensor Fusion Toolkit

NASA Technical Reports Server (NTRS)

Karlgaard, Christopher D.

2015-01-01

Analytical Mechanics Associates, Inc., has developed a software toolkit that filters and processes navigational data from multiple sensor sources. A key component of the toolkit is a trajectory optimization technique that reduces the sensitivity of Kalman filters with respect to model parameter uncertainties. The sensor fusion toolkit also integrates recent advances in adaptive Kalman and sigma-point filters for non-Gaussian problems with error statistics. This Phase II effort provides new filtering and sensor fusion techniques in a convenient package that can be used as a stand-alone application for ground support and/or onboard use. Its modular architecture enables ready integration with existing tools. A suite of sensor models and noise distribution as well as Monte Carlo analysis capability are included to enable statistical performance evaluations.

Options and limitations for bromate control during ozonation of wastewater.

PubMed

Soltermann, Fabian; Abegglen, Christian; Tschui, Manfred; Stahel, Sandro; von Gunten, Urs

2017-06-01

Wastewater treatment plants (WWTPs) are important point sources for micropollutants, which are harmful to freshwater organisms. Ozonation of wastewater is a powerful option to abate micropollutants, but may result in the formation of the potentially toxic oxidation by-product bromate in bromide-containing wastewaters. This study investigates options to reduce bromate formation during wastewater ozonation by (i) reducing the bromide concentration of the wastewater, (ii) lowering the ozone dose during wastewater treatment and (iii) adding hydrogen peroxide to limit the lifetime of ozone and quench the intermediates of the bromate formation pathway. Two examples demonstrate that a high share of bromide in wastewater can originate from single point sources (e.g., municipal waste incinerators or landfills). The identification of major point sources requires laborious sampling campaigns, but may facilitate the reduction of the bromide load significantly. To reduce the bromate formation by lowering the ozone dose interferes with the aim to abate micropollutants. Therefore, an additional treatment is necessary to ensure the elimination of micropollutants. Experiments at a pilot-plant illustrate that a combined treatment (ozone/powdered activated carbon) allows to eliminate micropollutants with low bromate yields. Furthermore, the addition of hydrogen peroxide was investigated at bench-scale. The bromate yields could be reduced by ∼50% and 65% for a hydrogen peroxide dose of 5 and 10 mg L -1 , respectively. In conclusion, there are options to reduce the bromate formation during wastewater ozonation, however, they are not simple with sometimes limited efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Applications of two-photon fluorescence microscopy in deep-tissue imaging

NASA Astrophysics Data System (ADS)

Dong, Chen-Yuan; Yu, Betty; Hsu, Lily L.; Kaplan, Peter D.; Blankschstein, D.; Langer, Robert; So, Peter T. C.

2000-07-01

Based on the non-linear excitation of fluorescence molecules, two-photon fluorescence microscopy has become a significant new tool for biological imaging. The point-like excitation characteristic of this technique enhances image quality by the virtual elimination of off-focal fluorescence. Furthermore, sample photodamage is greatly reduced because fluorescence excitation is limited to the focal region. For deep tissue imaging, two-photon microscopy has the additional benefit in the greatly improved imaging depth penetration. Since the near- infrared laser sources used in two-photon microscopy scatter less than their UV/glue-green counterparts, in-depth imaging of highly scattering specimen can be greatly improved. In this work, we will present data characterizing both the imaging characteristics (point-spread-functions) and tissue samples (skin) images using this novel technology. In particular, we will demonstrate how blind deconvolution can be used further improve two-photon image quality and how this technique can be used to study mechanisms of chemically-enhanced, transdermal drug delivery.

Water-quality assessment of the largely urban blue river basin, Metropolitan Kansas City, USA, 1998 to 2007

USGS Publications Warehouse

Wilkison, D.H.; Armstrong, D.J.; Hampton, S.A.

2009-01-01

From 1998 through 2007, over 750 surface-water or bed-sediment samples in the Blue River Basin - a largely urban basin in metropolitan Kansas City - were analyzed for more than 100 anthropogenic compounds. Compounds analyzed included nutrients, fecal-indicator bacteria, suspended sediment, pharmaceuticals and personal care products. Non-point source runoff, hydrologic alterations, and numerous waste-water discharge points resulted in the routine detection of complex mixtures of anthropogenic compounds in samples from basin stream sites. Temporal and spatial variations in concentrations and loads of nutrients, pharmaceuticals, and organic wastewater compounds were observed, primarily related to a site's proximity to point-source discharges and stream-flow dynamics. ?? 2009 ASCE.

Metals Fate And Transport Modelling In Streams And Watersheds: State Of The Science And USEPA Workshop Review

EPA Science Inventory

Metals pollution in surface waters from point and non-point sources (NPS) is a widespread problem in the United States and worldwide (Lofts et al., 2007; USEPA, 2007). In the western United States, metals associated with acid mine drainage (AMD) from hardrock mines in mou...

CARIDEAN GRASS SHRIMP (PALAEMONETES PUGIO HOLTHIUS) AS AN INDICATOR OF SEDIMENT QUALITY IN FLORIDA COASTAL AREAS AFFECTED BY POINT AND NON-POINT SOURCE CONTAMINATION

EPA Science Inventory

Grass shrimp are one of the more widely distributed estuarine benthic organisms along the Gulf of Mexico and Atlantic coasts, but they have been used infrequently in contaminated sediment assessments. Early life stages of the caridean grass shrimp, Palaemonetes pugio (Holthuis), ...

Fringe Formation in Dual-Hologram Interferometry

NASA Technical Reports Server (NTRS)

Burner, A. W.

1989-01-01

A first order geometrical optics treatment of holograms combined with the generation of interference fringes by two point sources is used to describe reference fringe formation in non-diffuse dual-hologram interferometry.

An analysis of job placement patterns of black and non-black male and female undergraduates at the University of Virginia and Hampton Institute. Ph.D. Thesis - Virginia Univ.

NASA Technical Reports Server (NTRS)

Anderson, A. F.

1974-01-01

Research questions were proposed to determine the relationship between independent variables (race, sex, and institution attended) and dependent variables (number of job offers received, salary received, and willingness to recommend source of employer contact). The control variables were academic major, grade point average, placement registration, nonemployment activity, employer, and source of employer contact. An analysis of the results revealed no statistical significance of the institution attended as a predictor of job offers or salary, although significant relationships were found between race and sex and number of job offers received. It was found that academic major, grade point average, and source of employer contact were more useful than race in the prediction of salary. Sex and nonemployment activity were found to be the most important variables in the model. The analysis also indicated that Black students received more job offers than non-Black students.

Pathogen reduction co-benefits of nutrient best management practices

PubMed Central

Wainger, Lisa A.; Barber, Mary C.

2016-01-01

Background Many of the practices currently underway to reduce nitrogen, phosphorus, and sediment loads entering the Chesapeake Bay have also been observed to support reduction of disease-causing pathogen loadings. We quantify how implementation of these practices, proposed to meet the nutrient and sediment caps prescribed by the Total Maximum Daily Load (TMDL), could reduce pathogen loadings and provide public health co-benefits within the Chesapeake Bay system. Methods We used published data on the pathogen reduction potential of management practices and baseline fecal coliform loadings estimated as part of prior modeling to estimate the reduction in pathogen loadings to the mainstem Potomac River and Chesapeake Bay attributable to practices implemented as part of the TMDL. We then compare the estimates with the baseline loadings of fecal coliform loadings to estimate the total pathogen reduction potential of the TMDL. Results We estimate that the TMDL practices have the potential to decrease disease-causing pathogen loads from all point and non-point sources to the mainstem Potomac River and the entire Chesapeake Bay watershed by 19% and 27%, respectively. These numbers are likely to be underestimates due to data limitations that forced us to omit some practices from analysis. Discussion Based on known impairments and disease incidence rates, we conclude that efforts to reduce nutrients may create substantial health co-benefits by improving the safety of water-contact recreation and seafood consumption. PMID:27904807

Pathogen reduction co-benefits of nutrient best management practices.

PubMed

Richkus, Jennifer; Wainger, Lisa A; Barber, Mary C

2016-01-01

Many of the practices currently underway to reduce nitrogen, phosphorus, and sediment loads entering the Chesapeake Bay have also been observed to support reduction of disease-causing pathogen loadings. We quantify how implementation of these practices, proposed to meet the nutrient and sediment caps prescribed by the Total Maximum Daily Load (TMDL), could reduce pathogen loadings and provide public health co-benefits within the Chesapeake Bay system. We used published data on the pathogen reduction potential of management practices and baseline fecal coliform loadings estimated as part of prior modeling to estimate the reduction in pathogen loadings to the mainstem Potomac River and Chesapeake Bay attributable to practices implemented as part of the TMDL. We then compare the estimates with the baseline loadings of fecal coliform loadings to estimate the total pathogen reduction potential of the TMDL. We estimate that the TMDL practices have the potential to decrease disease-causing pathogen loads from all point and non-point sources to the mainstem Potomac River and the entire Chesapeake Bay watershed by 19% and 27%, respectively. These numbers are likely to be underestimates due to data limitations that forced us to omit some practices from analysis. Based on known impairments and disease incidence rates, we conclude that efforts to reduce nutrients may create substantial health co-benefits by improving the safety of water-contact recreation and seafood consumption.

A multicentre audit of HDR/PDR brachytherapy absolute dosimetry in association with the INTERLACE trial (NCT015662405)

NASA Astrophysics Data System (ADS)

Díez, P.; Aird, E. G. A.; Sander, T.; Gouldstone, C. A.; Sharpe, P. H. G.; Lee, C. D.; Lowe, G.; Thomas, R. A. S.; Simnor, T.; Bownes, P.; Bidmead, M.; Gandon, L.; Eaton, D.; Palmer, A. L.

2017-12-01

A UK multicentre audit to evaluate HDR and PDR brachytherapy has been performed using alanine absolute dosimetry. This is the first national UK audit performing an absolute dose measurement at a clinically relevant distance (20 mm) from the source. It was performed in both INTERLACE (a phase III multicentre trial in cervical cancer) and non-INTERLACE brachytherapy centres treating gynaecological tumours. Forty-seven UK centres (including the National Physical Laboratory) were visited. A simulated line source was generated within each centre’s treatment planning system and dwell times calculated to deliver 10 Gy at 20 mm from the midpoint of the central dwell (representative of Point A of the Manchester system). The line source was delivered in a water-equivalent plastic phantom (Barts Solid Water) encased in blocks of PMMA (polymethyl methacrylate) and charge measured with an ion chamber at 3 positions (120° apart, 20 mm from the source). Absorbed dose was then measured with alanine at the same positions and averaged to reduce source positional uncertainties. Charge was also measured at 50 mm from the source (representative of Point B of the Manchester system). Source types included 46 HDR and PDR 192Ir sources, (7 Flexisource, 24 mHDR-v2, 12 GammaMed HDR Plus, 2 GammaMed PDR Plus, 1 VS2000) and 1 HDR 60Co source, (Co0.A86). Alanine measurements when compared to the centres’ calculated dose showed a mean difference (±SD) of  +1.1% (±1.4%) at 20 mm. Differences were also observed between source types and dose calculation algorithm. Ion chamber measurements demonstrated significant discrepancies between the three holes mainly due to positional variation of the source within the catheter (0.4%-4.9% maximum difference between two holes). This comprehensive audit of absolute dose to water from a simulated line source showed all centres could deliver the prescribed dose to within 5% maximum difference between measurement and calculation.

Modeling of Pixelated Detector in SPECT Pinhole Reconstruction.

PubMed

Feng, Bing; Zeng, Gengsheng L

2014-04-10

A challenge for the pixelated detector is that the detector response of a gamma-ray photon varies with the incident angle and the incident location within a crystal. The normalization map obtained by measuring the flood of a point-source at a large distance can lead to artifacts in reconstructed images. In this work, we investigated a method of generating normalization maps by ray-tracing through the pixelated detector based on the imaging geometry and the photo-peak energy for the specific isotope. The normalization is defined for each pinhole as the normalized detector response for a point-source placed at the focal point of the pinhole. Ray-tracing is used to generate the ideal flood image for a point-source. Each crystal pitch area on the back of the detector is divided into 60 × 60 sub-pixels. Lines are obtained by connecting between a point-source and the centers of sub-pixels inside each crystal pitch area. For each line ray-tracing starts from the entrance point at the detector face and ends at the center of a sub-pixel on the back of the detector. Only the attenuation by NaI(Tl) crystals along each ray is assumed to contribute directly to the flood image. The attenuation by the silica (SiO 2 ) reflector is also included in the ray-tracing. To calculate the normalization for a pinhole, we need to calculate the ideal flood for a point-source at 360 mm distance (where the point-source was placed for the regular flood measurement) and the ideal flood image for the point-source at the pinhole focal point, together with the flood measurement at 360 mm distance. The normalizations are incorporated in the iterative OSEM reconstruction as a component of the projection matrix. Applications to single-pinhole and multi-pinhole imaging showed that this method greatly reduced the reconstruction artifacts.

Characterization of occurrence, sources and sinks of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in a tropical urban catchment.

PubMed

Chen, Huiting; Reinhard, Martin; Nguyen, Tung Viet; You, Luhua; He, Yiliang; Gin, Karina Yew-Hoong

2017-08-01

Understanding the sources, occurrence and sinks of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in the urban water cycle is important to protect and utilize local water resources. Concentrations of 22 target PFASs and general water quality parameters were determined monthly for a year in filtered water samples from five tributaries and three sampling stations of an urban water body. Of the 22 target PFASs, 17 PFASs were detected with a frequency >93% including PFCAs: C4-C12 perfluoroalkyl carboxylates, C4, C6, C8, and C10 perfluoroalkane sulfonates, perfluorooctane sulfonamides and perfluorooctane sulfonamide substances (FOSAMs), C10 perfluoroalkyl phosphonic acid (C10 PFPA), 6:2 fluorotelomer sulfonic acid (6:2 FTSA) and C8/C8 perfluoroalkyl phosphinic acid (C8/C8-PFPIA). The most abundant PFASs in water were PFBS (1.4-55 ng/L), PFBA (1.0-23 ng/L), PFOS (1.5-24 ng/L) and PFOA (2.0-21 ng/L). In the tributaries, PFNA concentrations ranged from 1.2 to 87.1 ng/L except in the May 2013 samples of two tributaries, which reached 520 and 260 ng/L. Total PFAS concentrations in the sediment samples ranged from 1.6 to 15 ng/g d.w. with EtFOSAA, PFDoA, PFOS and PFDA being the dominant species. Based on water and sediment data, two types of sources were inferred: one-time or intermittent point sources and continuous non-point sources. FOSAMs and PFOS released continually from non-point sources, C8/C8 PFPIA, PFDoA and PFUnA was released from point sources. The highly water soluble short-chain PFASs including PFBA, PFPeA and PFBS remained predominantly in the water column. The factors governing solution phase concentrations appear to be compound hydrophobicity and sorption to suspended particles. Correlation of the dissolved phase concentrations with precipitation data suggested stormwater was a significant source of PFBA, PFBS, PFUnA and PFDoA. Negative correlations with precipitation indicated sources feeding FOSAA and FOSA directly into the tributaries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Water budget analysis and management for Bangkok Metropolis, Thailand.

PubMed

Singkran, Nuanchan

2017-09-01

The water budget of the Bangkok Metropolis system was analyzed using a material flow analysis model. Total imported flows into the system were 80,080 million m 3 per year (Mm 3 y -1 ) including inflows from the Chao Phraya and Mae Klong rivers and rainwater. Total exported flows out of the system were 78,528 Mm 3 y -1 including outflow into the lower Chao Phraya River and tap water (TW) distributed to suburbs. Total rates of stock exchange (1,552 Mm 3 y -1 ) were found in the processes of water recycling, TW distribution, domestic use, swine farming, aquaculture, and paddy fields. Only 21% of the total amount of wastewater (1,255 Mm 3 y -1 ) was collected, with insufficient treatment capacity of about 415 Mm 3 y -1 . Domestic and business (industrial and commercial sectors) areas were major point sources, whereas paddy fields were a major non-point source of wastewater. To manage Bangkok's water budget, critical measures have to be considered. Wastewater treatment capacity and efficiency of wastewater collection should be improved. On-site wastewater treatment plants for residential areas should be installed. Urban planning and land use zoning are suggested to control land use activities. Green technology should be supported to reduce wastewater from farming.

Nonpoint and Point Sources of Nitrogen in Major Watersheds of the United States

USGS Publications Warehouse

Puckett, Larry J.

1994-01-01

Estimates of nonpoint and point sources of nitrogen were made for 107 watersheds located in the U.S. Geological Survey's National Water-Quality Assessment Program study units throughout the conterminous United States. The proportions of nitrogen originating from fertilizer, manure, atmospheric deposition, sewage, and industrial sources were found to vary with climate, hydrologic conditions, land use, population, and physiography. Fertilizer sources of nitrogen are proportionally greater in agricultural areas of the West and the Midwest than in other parts of the Nation. Animal manure contributes large proportions of nitrogen in the South and parts of the Northeast. Atmospheric deposition of nitrogen is generally greatest in areas of greatest precipitation, such as the Northeast. Point sources (sewage and industrial) generally are predominant in watersheds near cities, where they may account for large proportions of the nitrogen in streams. The transport of nitrogen in streams increases as amounts of precipitation and runoff increase and is greatest in the Northeastern United States. Because no single nonpoint nitrogen source is dominant everywhere, approaches to control nitrogen must vary throughout the Nation. Watershed-based approaches to understanding nonpoint and point sources of contamination, as used by the National Water-Quality Assessment Program, will aid water-quality and environmental managers to devise methods to reduce nitrogen pollution.

3D reconstruction from non-uniform point clouds via local hierarchical clustering

NASA Astrophysics Data System (ADS)

Yang, Jiaqi; Li, Ruibo; Xiao, Yang; Cao, Zhiguo

2017-07-01

Raw scanned 3D point clouds are usually irregularly distributed due to the essential shortcomings of laser sensors, which therefore poses a great challenge for high-quality 3D surface reconstruction. This paper tackles this problem by proposing a local hierarchical clustering (LHC) method to improve the consistency of point distribution. Specifically, LHC consists of two steps: 1) adaptive octree-based decomposition of 3D space, and 2) hierarchical clustering. The former aims at reducing the computational complexity and the latter transforms the non-uniform point set into uniform one. Experimental results on real-world scanned point clouds validate the effectiveness of our method from both qualitative and quantitative aspects.

40 CFR 408.321 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Alaskan Herring Fillet... freshwater and saltwater fish and shellfish, to be processed, in the form in which it is received at the...

Image Reconstruction in Radio Astronomy with Non-Coplanar Synthesis Arrays

NASA Astrophysics Data System (ADS)

Goodrick, L.

2015-03-01

Traditional radio astronomy imaging techniques assume that the interferometric array is coplanar, with a small field of view, and that the two-dimensional Fourier relationship between brightness and visibility remains valid, allowing the Fast Fourier Transform to be used. In practice, to acquire more accurate data, the non-coplanar baseline effects need to be incorporated, as small height variations in the array plane introduces the w spatial frequency component. This component adds an additional phase shift to the incoming signals. There are two approaches to account for the non-coplanar baseline effects: either the full three-dimensional brightness and visibility model can be used to reconstruct an image, or the non-coplanar effects can be removed, reducing the three dimensional relationship to that of the two-dimensional one. This thesis describes and implements the w-projection and w-stacking algorithms. The aim of these algorithms is to account for the phase error introduced by non-coplanar synthesis arrays configurations, making the recovered visibilities more true to the actual brightness distribution model. This is done by reducing the 3D visibilities to a 2D visibility model. The algorithms also have the added benefit of wide-field imaging, although w-stacking supports a wider field of view at the cost of more FFT bin support. For w-projection, the w-term is accounted for in the visibility domain by convolving it out of the problem with a convolution kernel, allowing the use of the two-dimensional Fast Fourier Transform. Similarly, the w-Stacking algorithm applies a phase correction in the image domain to image layers to produce an intensity model that accounts for the non-coplanar baseline effects. This project considers the KAT7 array for simulation and analysis of the limitations and advantages of both the algorithms. Additionally, a variant of the Högbom CLEAN algorithm was used which employs contour trimming for extended source emission flagging. The CLEAN algorithm is an iterative two-dimensional deconvolution method that can further improve image fidelity by removing the effects of the point spread function which can obscure source data.

Levels of CDDs, CDFs, PCBs and Hg in Rural Soils of US (Project Overview)

EPA Science Inventory

No systematic survey of dioxins in soil has been conducted in the US. Soils represent the largest reservoir source of dioxins. As point source emissions are reduced emissions from soils become increasingly important. Understanding the distribution of dioxin levels in soils is ...

40 CFR Table 3 to Subpart Zzzz of... - Subsequent Performance Tests

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Existing non-emergency, non-black start CI stationary RICE with a brake horsepower >500 that are not... 4SLB stationary RICE with a brake horsepower >500 located at major sources and new or reconstructed CI stationary RICE with a brake horsepower >500 located at major sources Reduce CO emissions and not using a...

Land-based sources of marine pollution: Pesticides, PAHs and phthalates in coastal stream water, and heavy metals in coastal stream sediments in American Samoa.

PubMed

Polidoro, Beth A; Comeros-Raynal, Mia T; Cahill, Thomas; Clement, Cassandra

2017-03-15

The island nations and territories of the South Pacific are facing a number of pressing environmental concerns, including solid waste management and coastal pollution. Here we provide baseline information on the presence and concentration of heavy metals and selected organic contaminants (pesticides, PAHs, phthalates) in 7 coastal streams and in surface waters adjacent to the Futiga landfill in American Samoa. All sampled stream sediments contained high concentrations of lead, and some of mercury. Several coastal stream waters showed relatively high concentrations of diethyl phthalate and of organophosphate pesticides, above chronic toxicity values for fish and other aquatic organisms. Parathion, which has been banned by the US Environmental Protection Agency since 2006, was detected in several stream sites. Increased monitoring and initiatives to limit non-point source land-based pollution will greatly improve the state of freshwater and coastal resources, as well as reduce risks to human health in American Samoa. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simulation of agricultural non-point source pollution in Xichuan by using SWAT model

NASA Astrophysics Data System (ADS)

Xing, Linan; Zuo, Jiane; Liu, Fenglin; Zhang, Xiaohui; Cao, Qiguang

2018-02-01

This paper evaluated the applicability of using SWAT to access agricultural non-point source pollution in Xichuan area. In order to build the model, DEM, soil sort and land use map, climate monitoring data were collected as basic database. The SWAT model was calibrated and validated for the SWAT was carried out using streamflow, suspended solids, total phosphorus and total nitrogen records from 2009 to 2011. Errors, coefficient of determination and Nash-Sutcliffe coefficient were considered to evaluate the applicability. The coefficient of determination were 0.96, 0.66, 0.55 and 0.66 for streamflow, SS, TN, and TP, respectively. Nash-Sutcliffe coefficient were 0.93, 0.5, 0.52 and 0.63, respectively. The results all meet the requirements. It suggested that the SWAT model can simulate the study area.

Purification and reuse of non-point source wastewater via Myriophyllum-based integrative biotechnology: A review.

PubMed

Liu, Feng; Zhang, Shunan; Luo, Pei; Zhuang, Xuliang; Chen, Xiang; Wu, Jinshui

2018-01-01

In this review, the applications of Myriophyllum-based integrative biotechnology to remove common non-point source (NPS) pollutants, such as nitrogen, phosphorus, heavy metals, and organic pollutants (e.g., pesticides and antibiotics) are summarized. The removal of these pollutants via various mechanisms, including uptake by plant and microbial communities in macrophyte-based treatment systems are discussed. This review highlights the potential use of Myriophyllum biomass to produce animal feed, fertilizer, and other valuable by-products, which can yield cost-effective returns and attract more attention to the regulation and recycling of NPS pollutants. In addition, it demonstrates that utilization of Myriophyllum species is a promising and reliable strategy for wastewater treatment. The future development of sustainable Myriophyllum-based treatment systems is discussed from various perspectives. Copyright © 2017 Elsevier Ltd. All rights reserved.

Portuguese Coaches' Perceptions of and Preferences for Knowledge Sources Related to their Professional Background.

PubMed

Mesquita, Isabel; Isidro, Sofia; Rosado, António

2010-01-01

The purpose of this study was to analyse Portuguese coaches' perceptions of, and preferences for, knowledge sources as related to professional background; namely academic education level, coach education level and coaching experience. The study's participants comprised 336 Portuguese coaches from twenty-two sports. A questionnaire was used to identify coaches' demographic characteristics and representations about their preferred sources of coaching knowledge. MANOVA using Tukey's HSD test was used to compare groups. The results highlighted that coaches perceived that coaching knowledge is built from a broad range of sources from personal coaching and playing experiences to more explicit formal, informal and non-formal learning situations. Results indicated that the coaches ascribed more importance to experiential sources such as working with experts, learning by doing, interacting with peer coaches and attending informal seminars and clinics, than to the formal learning situations provided by the national coaching certification programs. Differences, however, were found in that coaches who had a greater background within higher education (physical) and sport valued informal and non-formal learning sources more than did coaches who were defined as not coming from an academic background. The findings point to the importance of developing new learning, experientially-based, opportunities within the Portuguese context, where curricula content continues to be delivered via didactic means. Key pointsCoaches recognized that learning is obtained from a broad range of sources of coaching knowledge and each source has a particular role in the development of a coach.Experiential guided sources reached more importance to coaches as working with experts, learning by doing, attending seminars/clinics outside of the formal system and interaction with peers were the most acknowledged.The only source that is related to formal learning, national certification programs, was recognized as the less importance than all informal and non-formal learning situations.The profile of the source of coaching knowledge showed to be stable among coaches as only the academic education level differentiated the coaches' perceptions.

Portuguese Coaches’ Perceptions of and Preferences for Knowledge Sources Related to their Professional Background

PubMed Central

Mesquita, Isabel; Isidro, Sofia; Rosado, António

2010-01-01

The purpose of this study was to analyse Portuguese coaches’ perceptions of, and preferences for, knowledge sources as related to professional background; namely academic education level, coach education level and coaching experience. The study’s participants comprised 336 Portuguese coaches from twenty-two sports. A questionnaire was used to identify coaches’ demographic characteristics and representations about their preferred sources of coaching knowledge. MANOVA using Tukey’s HSD test was used to compare groups. The results highlighted that coaches perceived that coaching knowledge is built from a broad range of sources from personal coaching and playing experiences to more explicit formal, informal and non-formal learning situations. Results indicated that the coaches ascribed more importance to experiential sources such as working with experts, learning by doing, interacting with peer coaches and attending informal seminars and clinics, than to the formal learning situations provided by the national coaching certification programs. Differences, however, were found in that coaches who had a greater background within higher education (physical) and sport valued informal and non-formal learning sources more than did coaches who were defined as not coming from an academic background. The findings point to the importance of developing new learning, experientially-based, opportunities within the Portuguese context, where curricula content continues to be delivered via didactic means. Key points Coaches recognized that learning is obtained from a broad range of sources of coaching knowledge and each source has a particular role in the development of a coach. Experiential guided sources reached more importance to coaches as working with experts, learning by doing, attending seminars/clinics outside of the formal system and interaction with peers were the most acknowledged. The only source that is related to formal learning, national certification programs, was recognized as the less importance than all informal and non-formal learning situations. The profile of the source of coaching knowledge showed to be stable among coaches as only the academic education level differentiated the coaches’ perceptions. PMID:24149644

Total Nitrogen Sources of the Three Gorges Reservoir — A Spatio-Temporal Approach

PubMed Central

Ren, Chunping; Wang, Lijing; Zheng, Binghui; Holbach, Andreas

2015-01-01

Understanding the spatial and temporal variation of nutrient concentrations, loads, and their distribution from upstream tributaries is important for the management of large lakes and reservoirs. The Three Gorges Dam was built on the Yangtze River in China, the world’s third longest river, and impounded the famous Three Gorges Reservoir (TGR). In this study, we analyzed total nitrogen (TN) concentrations and inflow data from 2003 till 2010 for the main upstream tributaries of the TGR that contribute about 82% of the TGR’s total inflow. We used time series analysis for seasonal decomposition of TN concentrations and used non-parametric statistical tests (Kruskal-Walli H, Mann-Whitney U) as well as base flow segmentation to analyze significant spatial and temporal patterns of TN pollution input into the TGR. Our results show that TN concentrations had significant spatial heterogeneity across the study area (Tuo River> Yangtze River> Wu River> Min River> Jialing River>Jinsha River). Furthermore, we derived apparent seasonal changes in three out of five upstream tributaries of the TGR rivers (Kruskal-Walli H ρ = 0.009, 0.030 and 0.029 for Tuo River, Jinsha River and Min River in sequence). TN pollution from non-point sources in the upstream tributaries accounted for 68.9% of the total TN input into the TGR. Non-point source pollution of TN revealed increasing trends for 4 out of five upstream tributaries of the TGR. Land use/cover and soil type were identified as the dominant driving factors for the spatial distribution of TN. Intensifying agriculture and increasing urbanization in the upstream catchments of the TGR were the main driving factors for non-point source pollution of TN increase from 2003 till 2010. Land use and land cover management as well as chemical fertilizer use restriction were needed to overcome the threats of increasing TN pollution. PMID:26510158

Method for reducing energy losses in laser crystals

DOEpatents

Atherton, L.J.; DeYoreo, J.J.; Roberts, D.H.

1992-03-24

A process for reducing energy losses in crystals is disclosed which comprises: a. heating a crystal to a temperature sufficiently high as to cause dissolution of microscopic inclusions into the crystal, thereby converting said inclusions into point-defects, and b. maintaining said crystal at a given temperature for a period of time sufficient to cause said point-defects to diffuse out of said crystal. Also disclosed are crystals treated by the process, and lasers utilizing the crystals as a source of light. 12 figs.

Method for reducing energy losses in laser crystals

DOEpatents

Atherton, L. Jeffrey; DeYoreo, James J.; Roberts, David H.

1992-01-01

A process for reducing energy losses in crystals is disclosed which comprises: a. heating a crystal to a temperature sufficiently high as to cause dissolution of microscopic inclusions into the crystal, thereby converting said inclusions into point-defects, and b. maintaining said crystal at a given temperature for a period of time sufficient to cause said point-defects to diffuse out of said crystal. Also disclosed are crystals treated by the process, and lasers utilizing the crystals as a source of light.

Active and Passive Hydrologic Tomographic Surveys:A Revolution in Hydrology (Invited)

NASA Astrophysics Data System (ADS)

Yeh, T. J.

2013-12-01

Mathematical forward or inverse problems of flow through geological media always have unique solutions if necessary conditions are givens. Unique mathematical solutions to forward or inverse modeling of field problems are however always uncertain (an infinite number of possibilities) due to many reasons. They include non-representativeness of the governing equations, inaccurate necessary conditions, multi-scale heterogeneity, scale discrepancies between observation and model, noise and others. Conditional stochastic approaches, which derives the unbiased solution and quantifies the solution uncertainty, are therefore most appropriate for forward and inverse modeling of hydrological processes. Conditioning using non-redundant data sets reduces uncertainty. In this presentation, we explain non-redundant data sets in cross-hole aquifer tests, and demonstrate that active hydraulic tomographic survey (using man-made excitations) is a cost-effective approach to collect the same type but non-redundant data sets for reducing uncertainty in the inverse modeling. We subsequently show that including flux measurements (a piece of non-redundant data set) collected in the same well setup as in hydraulic tomography improves the estimated hydraulic conductivity field. We finally conclude with examples and propositions regarding how to collect and analyze data intelligently by exploiting natural recurrent events (river stage fluctuations, earthquakes, lightning, etc.) as energy sources for basin-scale passive tomographic surveys. The development of information fusion technologies that integrate traditional point measurements and active/passive hydrogeophysical tomographic surveys, as well as advances in sensor, computing, and information technologies may ultimately advance our capability of characterizing groundwater basins to achieve resolution far beyond the feat of current science and technology.

Variation in Patient Profiles and Outcomes in US and Non-US Subgroups of the Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition (CHAMPION) PHOENIX Trial

PubMed Central

Vaduganathan, Muthiah; Harrington, Robert A.; Stone, Gregg W.; Steg, Ph. Gabriel; Gibson, C. Michael; Hamm, Christian W.; Price, Matthew J.; Prats, Jayne; Deliargyris, Efthymios N.; Mahaffey, Kenneth W.; White, Harvey D.

2016-01-01

Background— The Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition (CHAMPION) PHOENIX trial demonstrated superiority of cangrelor in reducing ischemic events at 48 hours in patients undergoing percutaneous coronary intervention compared with clopidogrel. Methods and Results— We analyzed all patients included in the modified intention-to-treat analysis in US (n=4097; 37.4%) and non-US subgroups (n=6845; 62.6%). The US cohort was older, had a higher burden of cardiovascular risk factors, and had more frequently undergone prior cardiovascular procedures. US patients more frequently underwent percutaneous coronary intervention for stable angina (77.9% versus 46.2%). Almost all US patients (99.1%) received clopidogrel loading doses of 600 mg, whereas 40.5% of non-US patients received 300 mg. Bivalirudin was more frequently used in US patients (56.7% versus 2.9%). At 48 hours, rates of the primary composite end point were comparable in the US and non-US cohorts (5.5% versus 5.2%; P=0.53). Cangrelor reduced rates of the primary composite end point compared with clopidogrel in US (4.5% versus 6.4%; odds ratio 0.70 [95% confidence interval 0.53–0.92]) and in non-US patients (4.8% versus 5.6%; odds ratio 0.85 [95% confidence interval 0.69–1.05]; interaction P=0.26). Similarly, rates of the key secondary end point, stent thrombosis, were reduced by cangrelor in both regions. Rates of Global Use of Strategies to Open Occluded Arteries (GUSTO)–defined severe bleeding were low and not significantly increased by cangrelor in either region. Conclusions— Despite broad differences in clinical profiles and indications for percutaneous coronary intervention by region in a large global cardiovascular clinical trial, cangrelor consistently reduced rates of ischemic end points compared with clopidogrel without an excess in severe bleeding in both the US and non-US subgroups. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01156571. PMID:27313282

Analysis of the mechanism of injury in non-fatal vehicle-to-pedestrian and vehicle-to-bicyclist frontal crashes in Sweden.

PubMed

Öman, Mikael; Fredriksson, Rikard; Bylund, Per-Olof; Björnstig, Ulf

2016-12-01

The aim of this paper is to analyse and compare injuries and injury sources in pedestrian and bicyclist non-fatal real-life frontal passengercar crashes, considering in what way pedestrian injury mitigation systems also might be adequate for bicyclists. Data from 203 non-fatal vehicle-to-pedestrian and vehicle-to-bicyclist crashes from 1997 through 2006 in a city in northern Sweden were analysed by use of the hospitals injury data base in addition to interviews with the injured. In vehicle-to-pedestrian crashes (n = 103) head and neck injuries were in general due to hitting the windscreen frame, while in vehicle-to-bicycle crashes (n = 100) head and neck injuries were typically sustained by ground impact. Abdominal, pelvic and thoracic injuries in pedestrians and thoracic injuries in bicyclists were in general caused by impacting the bonnet. In vehicle-to-pedestrian crashes, energy reducing airbags at critical impact points with low yielding ability on the car, as the bonnet and the windscreen frame, might reduce injuries. As vehicle-to-bicyclist crashes occurred mostly in good lighting conditions and visibility and the ground impact causing almost four times as many injuries as an impact to the different regions of the car, crash avoidance systems as well as separating bicyclists from motor traffic, may contribute to mitigate these injuries.

THE POSSIBLE IMPACT OF L5 MAGNETOGRAMS ON NON-POTENTIAL SOLAR CORONAL MAGNETIC FIELD SIMULATIONS

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

Weinzierl, Marion; Yeates, Anthony R.; Mackay, Duncan H.

The proposed Carrington-L5 mission would bring instruments to the L5 Lagrange point to provide us with crucial data for space weather prediction. To assess the importance of including a magnetograph, we consider the possible differences in non-potential solar coronal magnetic field simulations when magnetograph observations are available from the L5 point, compared with an L1-based field of view (FOV). A timeseries of synoptic radial magnetic field maps is constructed to capture the emergence of two active regions from the L5 FOV. These regions are initially absent in the L1 magnetic field maps, but are included once they rotate into themore » L1 FOV. Non-potential simulations for these two sets of input data are compared in detail. Within the bipolar active regions themselves, differences in the magnetic field structure can exist between the two simulations once the active regions are included in both. These differences tend to reduce within 5 days of the active region being included in L1. The delayed emergence in L1 can, however, lead to significant persistent differences in long-range connectivity between the active regions and the surrounding fields, and also in the global magnetic energy. In particular, the open magnetic flux and the location of open magnetic footpoints, are sensitive to capturing the real-time of emergence. These results suggest that a magnetograph at L5 could significantly improve predictions of the non-potential corona, the interplanetary magnetic field, and of solar wind source regions on the Sun.« less

Chesapeake Bay Tributary Strategies

EPA Pesticide Factsheets

Chesapeake Bay Tributary Strategies were developed by the seven watershed jurisdictions and outlined the river basin-specific implementation activities to reduce nutrient and sediment pollutant loads from point and nonpoint sources.

40 CFR 445.22 - Effluent limitations attainable by the application of the best conventional pollutant control...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LANDFILLS POINT SOURCE CATEGORY RCRA Subtitle D Non-Hazardous Waste Landfill § 445.22 Effluent limitations attainable by...

Mapping algorithm for freeform construction using non-ideal light sources

NASA Astrophysics Data System (ADS)

Li, Chen; Michaelis, D.; Schreiber, P.; Dick, L.; Bräuer, A.

2015-09-01

Using conventional mapping algorithms for the construction of illumination freeform optics' arbitrary target pattern can be obtained for idealized sources, e.g. collimated light or point sources. Each freeform surface element generates an image point at the target and the light intensity of an image point is corresponding to the area of the freeform surface element who generates the image point. For sources with a pronounced extension and ray divergence, e.g. an LED with a small source-freeform-distance, the image points are blurred and the blurred patterns might be different between different points. Besides, due to Fresnel losses and vignetting, the relationship between light intensity of image points and area of freeform surface elements becomes complicated. These individual light distributions of each freeform element are taken into account in a mapping algorithm. To this end the method of steepest decent procedures are used to adapt the mapping goal. A structured target pattern for a optics system with an ideal source is computed applying corresponding linear optimization matrices. Special weighting factor and smoothing factor are included in the procedures to achieve certain edge conditions and to ensure the manufacturability of the freefrom surface. The corresponding linear optimization matrices, which are the lighting distribution patterns of each of the freeform surface elements, are gained by conventional raytracing with a realistic source. Nontrivial source geometries, like LED-irregularities due to bonding or source fine structures, and a complex ray divergence behavior can be easily considered. Additionally, Fresnel losses, vignetting and even stray light are taken into account. After optimization iterations, with a realistic source, the initial mapping goal can be achieved by the optics system providing a structured target pattern with an ideal source. The algorithm is applied to several design examples. A few simple tasks are presented to discussed the ability and limitation of the this mothed. It is also presented that a homogeneous LED-illumination system design, in where, with a strongly tilted incident direction, a homogeneous distribution is achieved with a rather compact optics system and short working distance applying a relatively large LED source. It is shown that the lighting distribution patterns from the freeform surface elements can be significantly different from the others. The generation of a structured target pattern, applying weighting factor and smoothing factor, are discussed. Finally, freeform designs for much more complex sources like clusters of LED-sources are presented.

Experimental derivation of the fluence non-uniformity correction for air kerma near brachytherapy linear sources

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

Vianello, E. A.; Almeida, C. E. de

2008-07-15

In brachytherapy, one of the elements to take into account for measurements free in air is the non-uniformity of the photon fluence due to the beam divergence that causes a steep dose gradient near the source. The correction factors for this phenomenon have been usually evaluated by two available theories by Kondo and Randolph [Radiat. Res. 13, 37-60 (1960)] and Bielajew [Phys. Med. Biol. 35, 517-538 (1990)], both conceived for point sources. This work presents the experimental validation of the Monte Carlo calculations made by Rodriguez and deAlmeida [Phys. Med. Biol. 49, 1705-1709 (2004)] for the non-uniformity correction specifically formore » a Cs-137 linear source measured using a Farmer type ionization chamber. The experimental values agree very well with the Monte Carlo calculations and differ from the results predicted by both theoretical models widely used. This result confirms that for linear sources there are some important differences at short distances from the source and emphasizes that those theories should not be used for linear sources. The data provided in this study confirm the limitations of the mentioned theories when linear sources are used. Considering the difficulties and uncertainties associated with the experimental measurements, it is recommended to use the Monte Carlo data to assess the non-uniformity factors for linear sources in situations that require this knowledge.« less

Periodicity and Chaos Amidst Twisting and Folding in Two-Dimensional Maps

NASA Astrophysics Data System (ADS)

Garst, Swier; Sterk, Alef E.

We study the dynamics of three planar, noninvertible maps which rotate and fold the plane. Two maps are inspired by real-world applications whereas the third map is constructed to serve as a toy model for the other two maps. The dynamics of the three maps are remarkably similar. A stable fixed point bifurcates through a Hopf-Neĭmark-Sacker which leads to a countably infinite set of resonance tongues in the parameter plane of the map. Within a resonance tongue a periodic point can bifurcate through a period-doubling cascade. At the end of the cascade we detect Hénon-like attractors which are conjectured to be the closure of the unstable manifold of a saddle periodic point. These attractors have a folded structure which can be explained by means of the concept of critical lines. We also detect snap-back repellers which can either coexist with Hénon-like attractors or which can be formed when the saddle-point of a Hénon-like attractor becomes a source.

The evolving Planck mass in classically scale-invariant theories

NASA Astrophysics Data System (ADS)

Kannike, K.; Raidal, M.; Spethmann, C.; Veermäe, H.

2017-04-01

We consider classically scale-invariant theories with non-minimally coupled scalar fields, where the Planck mass and the hierarchy of physical scales are dynamically generated. The classical theories possess a fixed point, where scale invariance is spontaneously broken. In these theories, however, the Planck mass becomes unstable in the presence of explicit sources of scale invariance breaking, such as non-relativistic matter and cosmological constant terms. We quantify the constraints on such classical models from Big Bang Nucleosynthesis that lead to an upper bound on the non-minimal coupling and require trans-Planckian field values. We show that quantum corrections to the scalar potential can stabilise the fixed point close to the minimum of the Coleman-Weinberg potential. The time-averaged motion of the evolving fixed point is strongly suppressed, thus the limits on the evolving gravitational constant from Big Bang Nucleosynthesis and other measurements do not presently constrain this class of theories. Field oscillations around the fixed point, if not damped, contribute to the dark matter density of the Universe.

ATVB Council Statement: Non-statin LDL-lowering Therapy and Cardiovascular Risk Reduction

PubMed Central

Hegele, Robert A.; Gidding, Samuel S.; Ginsberg, Henry N.; McPherson, Ruth; Raal, Frederick J.; Rader, Daniel J.; Robinson, Jennifer G.; Welty, Francine K.

2015-01-01

Pharmacologic reduction of low-density lipoprotein (LDL) cholesterol using statin drugs is foundational therapy to reduce cardiovascular disease (CVD) risk. Here we consider the place of non-statin therapies that also reduce LDL cholesterol in prevention of CVD. Among conventional non-statins, placebo-controlled randomized clinical trials showed that bile acid sequestrants, niacin and fibrates given as monotherapy each reduce CVD end points. From trials in which patients’ LDL cholesterol was already well-controlled on a statin, adding ezetimibe incrementally reduced CVD end points, while adding a fibrate or niacin showed no incremental benefit. Among emerging non-statins, monoclonal antibodies against proprotein convertase subtilisin kexin type 9 (PCSK9) added to a statin and given for up to 78 weeks showed preliminary evidence of reductions in CVD outcomes. While these promising early findings contributed to the recent approval of these agents in Europe and the US, much larger and longer duration outcomes studies are ongoing for definitive proof of CVD benefits. Other non-statin agents recently approved in the US include lomitapide and mipomersen, which both act via distinctive LDL-receptor independent mechanisms to substantially reduce LDL cholesterol in homozygous familial hypercholesterolemia. We also address some unanswered questions, including measuring alternative biochemical variables to LDL cholesterol, evidence for treating children with monitoring of subclinical atherosclerosis, and potential risks of extremely low LDL cholesterol. As evidence for benefit in CVD prevention accumulates, we anticipate that clinical practice will shift towards more assertive LDL-lowering treatment, using both statins and non-statins initiated earlier in appropriately selected patients. PMID:26376908

Strategies for satellite-based monitoring of CO2 from distributed area and point sources

NASA Astrophysics Data System (ADS)

Schwandner, Florian M.; Miller, Charles E.; Duren, Riley M.; Natraj, Vijay; Eldering, Annmarie; Gunson, Michael R.; Crisp, David

2014-05-01

Atmospheric CO2 budgets are controlled by the strengths, as well as the spatial and temporal variabilities of CO2 sources and sinks. Natural CO2 sources and sinks are dominated by the vast areas of the oceans and the terrestrial biosphere. In contrast, anthropogenic and geogenic CO2 sources are dominated by distributed area and point sources, which may constitute as much as 70% of anthropogenic (e.g., Duren & Miller, 2012), and over 80% of geogenic emissions (Burton et al., 2013). Comprehensive assessments of CO2 budgets necessitate robust and highly accurate satellite remote sensing strategies that address the competing and often conflicting requirements for sampling over disparate space and time scales. Spatial variability: The spatial distribution of anthropogenic sources is dominated by patterns of production, storage, transport and use. In contrast, geogenic variability is almost entirely controlled by endogenic geological processes, except where surface gas permeability is modulated by soil moisture. Satellite remote sensing solutions will thus have to vary greatly in spatial coverage and resolution to address distributed area sources and point sources alike. Temporal variability: While biogenic sources are dominated by diurnal and seasonal patterns, anthropogenic sources fluctuate over a greater variety of time scales from diurnal, weekly and seasonal cycles, driven by both economic and climatic factors. Geogenic sources typically vary in time scales of days to months (geogenic sources sensu stricto are not fossil fuels but volcanoes, hydrothermal and metamorphic sources). Current ground-based monitoring networks for anthropogenic and geogenic sources record data on minute- to weekly temporal scales. Satellite remote sensing solutions would have to capture temporal variability through revisit frequency or point-and-stare strategies. Space-based remote sensing offers the potential of global coverage by a single sensor. However, no single combination of orbit and sensor provides the full range of temporal sampling needed to characterize distributed area and point source emissions. For instance, point source emission patterns will vary with source strength, wind speed and direction. Because wind speed, direction and other environmental factors change rapidly, short term variabilities should be sampled. For detailed target selection and pointing verification, important lessons have already been learned and strategies devised during JAXA's GOSAT mission (Schwandner et al, 2013). The fact that competing spatial and temporal requirements drive satellite remote sensing sampling strategies dictates a systematic, multi-factor consideration of potential solutions. Factors to consider include vista, revisit frequency, integration times, spatial resolution, and spatial coverage. No single satellite-based remote sensing solution can address this problem for all scales. It is therefore of paramount importance for the international community to develop and maintain a constellation of atmospheric CO2 monitoring satellites that complement each other in their temporal and spatial observation capabilities: Polar sun-synchronous orbits (fixed local solar time, no diurnal information) with agile pointing allow global sampling of known distributed area and point sources like megacities, power plants and volcanoes with daily to weekly temporal revisits and moderate to high spatial resolution. Extensive targeting of distributed area and point sources comes at the expense of reduced mapping or spatial coverage, and the important contextual information that comes with large-scale contiguous spatial sampling. Polar sun-synchronous orbits with push-broom swath-mapping but limited pointing agility may allow mapping of individual source plumes and their spatial variability, but will depend on fortuitous environmental conditions during the observing period. These solutions typically have longer times between revisits, limiting their ability to resolve temporal variations. Geostationary and non-sun-synchronous low-Earth-orbits (precessing local solar time, diurnal information possible) with agile pointing have the potential to provide, comprehensive mapping of distributed area sources such as megacities with longer stare times and multiple revisits per day, at the expense of global access and spatial coverage. An ad hoc CO2 remote sensing constellation is emerging. NASA's OCO-2 satellite (launch July 2014) joins JAXA's GOSAT satellite in orbit. These will be followed by GOSAT-2 and NASA's OCO-3 on the International Space Station as early as 2017. Additional polar orbiting satellites (e.g., CarbonSat, under consideration at ESA) and geostationary platforms may also become available. However, the individual assets have been designed with independent science goals and requirements, and limited consideration of coordinated observing strategies. Every effort must be made to maximize the science return from this constellation. We discuss the opportunities to exploit the complementary spatial and temporal coverage provided by these assets as well as the crucial gaps in the capabilities of this constellation. References Burton, M.R., Sawyer, G.M., and Granieri, D. (2013). Deep carbon emissions from volcanoes. Rev. Mineral. Geochem. 75: 323-354. Duren, R.M., Miller, C.E. (2012). Measuring the carbon emissions of megacities. Nature Climate Change 2, 560-562. Schwandner, F.M., Oda, T., Duren, R., Carn, S.A., Maksyutov, S., Crisp, D., Miller, C.E. (2013). Scientific Opportunities from Target-Mode Capabilities of GOSAT-2. NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena CA, White Paper, 6p., March 2013.

Galactic Starburst NGC 3603 from X-Rays to Radio

NASA Technical Reports Server (NTRS)

Moffat, A. F. J.; Corcoran, M. F.; Stevens, I. R.; Skalkowski, G.; Marchenko, S. V.; Muecke, A.; Ptak, A.; Koribalski, B. S.; Brenneman, L.; Mushotzky, R.;

Improvement of correlation-based centroiding methods for point source Shack-Hartmann wavefront sensor

NASA Astrophysics Data System (ADS)

Li, Xuxu; Li, Xinyang; wang, Caixia

2018-03-01

This paper proposes an efficient approach to decrease the computational costs of correlation-based centroiding methods used for point source Shack-Hartmann wavefront sensors. Four typical similarity functions have been compared, i.e. the absolute difference function (ADF), ADF square (ADF2), square difference function (SDF), and cross-correlation function (CCF) using the Gaussian spot model. By combining them with fast search algorithms, such as three-step search (TSS), two-dimensional logarithmic search (TDL), cross search (CS), and orthogonal search (OS), computational costs can be reduced drastically without affecting the accuracy of centroid detection. Specifically, OS reduces calculation consumption by 90%. A comprehensive simulation indicates that CCF exhibits a better performance than other functions under various light-level conditions. Besides, the effectiveness of fast search algorithms has been verified.

NPTFit: A Code Package for Non-Poissonian Template Fitting

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

Mishra-Sharma, Siddharth; Rodd, Nicholas L.; Safdi, Benjamin R., E-mail: smsharma@princeton.edu, E-mail: nrodd@mit.edu, E-mail: bsafdi@mit.edu

We present NPTFit, an open-source code package, written in Python and Cython, for performing non-Poissonian template fits (NPTFs). The NPTF is a recently developed statistical procedure for characterizing the contribution of unresolved point sources (PSs) to astrophysical data sets. The NPTF was first applied to Fermi gamma-ray data to provide evidence that the excess of ∼GeV gamma-rays observed in the inner regions of the Milky Way likely arises from a population of sub-threshold point sources, and the NPTF has since found additional applications studying sub-threshold extragalactic sources at high Galactic latitudes. The NPTF generalizes traditional astrophysical template fits to allowmore » for the ability to search for populations of unresolved PSs that may follow a given spatial distribution. NPTFit builds upon the framework of the fluctuation analyses developed in X-ray astronomy, thus it likely has applications beyond those demonstrated with gamma-ray data. The NPTFit package utilizes novel computational methods to perform the NPTF efficiently. The code is available at http://github.com/bsafdi/NPTFit and up-to-date and extensive documentation may be found at http://nptfit.readthedocs.io.« less

Introducing nonpoint source transferable quotas in nitrogen trading: The effects of transaction costs and uncertainty.

PubMed

Zhou, Xiuru; Ye, Weili; Zhang, Bing

2016-03-01

Transaction costs and uncertainty are considered to be significant obstacles in the emissions trading market, especially for including nonpoint source in water quality trading. This study develops a nonlinear programming model to simulate how uncertainty and transaction costs affect the performance of point/nonpoint source (PS/NPS) water quality trading in the Lake Tai watershed, China. The results demonstrate that PS/NPS water quality trading is a highly cost-effective instrument for emissions abatement in the Lake Tai watershed, which can save 89.33% on pollution abatement costs compared to trading only between nonpoint sources. However, uncertainty can significantly reduce the cost-effectiveness by reducing trading volume. In addition, transaction costs from bargaining and decision making raise total pollution abatement costs directly and cause the offset system to deviate from the optimal state. While proper investment in monitoring and measuring of nonpoint emissions can decrease uncertainty and save on the total abatement costs. Finally, we show that the dispersed ownership of China's farmland will bring high uncertainty and transaction costs into the PS/NPS offset system, even if the pollution abatement cost is lower than for point sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

Non-cancer health effects of pesticides

PubMed Central

Sanborn, M.; Kerr, K.J.; Sanin, L.H.; Cole, D.C.; Bassil, K.L.; Vakil, C.

2007-01-01

OBJECTIVE To investigate whether there are associations between exposure to pesticides and 4 chronic non-cancer health effects: dermatologic, neurologic, reproductive, and genotoxic effects. DATA SOURCES We searched PreMedline, MEDLINE, and LILACS using the key word pesticide combined with the term for the specific health effect being searched. Reviewers scanned the references of all articles for additional relevant studies. STUDY SELECTION Studies since 1992 were assessed using structured inclusion and quality-of-methods criteria. Studies scoring <4 on a 7-point global methodologic quality scale were excluded. In total, 124 studies were included. These studies had a mean quality score of 4.88 out of 7. SYNTHESIS Strong evidence of association with pesticide exposure was found for all neurologic outcomes, genotoxicity, and 4 of 6 reproductive effects: birth defects, fetal death, altered growth, and other outcomes. Exposure to pesticides generally doubled the level of genetic damage as measured by chromosome aberrations in lymphocytes. Only a few high-quality studies focused on the dermatologic effects of pesticides. In some of these studies, rates of dermatitis were higher among those who had had high exposure to pesticides on the job. CONCLUSION Evidence from research on humans consistently points to positive associations between pesticide exposure and 3 of the 4 non-cancer health outcomes studied. Physicians have a dual role in educating individual patients about the risks of exposure and in reducing exposure in the community by advocating for restrictions on use of pesticides. PMID:17934035

Parameter estimation for slit-type scanning sensors

NASA Technical Reports Server (NTRS)

Fowler, J. W.; Rolfe, E. G.

1981-01-01

The Infrared Astronomical Satellite, scheduled for launch into a 900 km near-polar orbit in August 1982, will perform an infrared point source survey by scanning the sky with slit-type sensors. The description of position information is shown to require the use of a non-Gaussian random variable. Methods are described for deciding whether separate detections stem from a single common source, and a formulism is developed for the scan-to-scan problems of identifying multiple sightings of inertially fixed point sources for combining their individual measurements into a refined estimate. Several cases are given where the general theory yields results which are quite different from the corresponding Gaussian applications, showing that argument by Gaussian analogy would lead to error.

Méthode de synthèse de la structure des convertisseurs multi-niveaux

NASA Astrophysics Data System (ADS)

Bartholoméüs, P.; Le Moigne, P.; Rombaut, C.

1997-09-01

In this paper a study of the multilevel converters' structures is presented. Multilevel cells with series connection of voltage sources are considered. The notion of power reversibility of the cell is introduced. It allows for the definition of reversible and non-reversible converter structures. The knowledge of the sign of the current which circulates in the cell permits the definition of the static characteristics of the switches involved in the connection between the different points of the voltage source and the current source. Two configurations of the cells are studied. For each one, the static characteristic of each switch is determined. For the first configuration, called “N_c-switch cell", each point of the voltage source is connected to the current source by one switch only. The second one is constituted of a stacking-up of switching elementary cells. It is called “elementary cell association structure". In this case, several switches are involved in each connection. Thanks to these two configurations, different cells have been developed, and they allow for the definition of new structures of rectifiers. Une méthode d'étude des structures de convertisseurs réalisés à partir de cellules multi-niveaux à association de sources de tension en série est présentée. La notion de non réversibilité en puissance de la cellule de commutation est introduite. Elle permet la définition des structures de conversion réversibles ou non réversibles. À partir du sens de circulation du courant dans les cellules, il est possible de définir la caractéristique statique des interrupteurs réalisant les connexions entre un des différents points de la source de tension et la source de courant. Deux trames d'interrupteurs sont considérées. Pour la première, nommée “cellule à N_c interrupteurs", les connexions sont réalisées par un seul interrupteur à la fois. Pour la seconde, constituée d'un empilage de cellules élémentaires de commutation, et nommée “cellule à association de cellules élémentaires", les connexions nécessitent la mise en série de plusieurs interrupteurs. À partir de ces deux trames d'interrupteurs, plusieurs cellules conduisant à de nouvelles structures de redresseurs non réversibles ont pu être définies.

[Nitrogen non-point source pollution identification based on ArcSWAT in Changle River].

PubMed

Deng, Ou-Ping; Sun, Si-Yang; Lü, Jun

2013-04-01

The ArcSWAT (Soil and Water Assessment Tool) model was adopted for Non-point source (NPS) nitrogen pollution modeling and nitrogen source apportionment for the Changle River watershed, a typical agricultural watershed in Southeast China. Water quality and hydrological parameters were monitored, and the watershed natural conditions (including soil, climate, land use, etc) and pollution sources information were also investigated and collected for SWAT database. The ArcSWAT model was established in the Changle River after the calibrating and validating procedures of the model parameters. Based on the validated SWAT model, the contributions of different nitrogen sources to river TN loading were quantified, and spatial-temporal distributions of NPS nitrogen export to rivers were addressed. The results showed that in the Changle River watershed, Nitrogen fertilizer, nitrogen air deposition and nitrogen soil pool were the prominent pollution sources, which contributed 35%, 32% and 25% to the river TN loading, respectively. There were spatial-temporal variations in the critical sources for NPS TN export to the river. Natural sources, such as soil nitrogen pool and atmospheric nitrogen deposition, should be targeted as the critical sources for river TN pollution during the rainy seasons. Chemical nitrogen fertilizer application should be targeted as the critical sources for river TN pollution during the crop growing season. Chemical nitrogen fertilizer application, soil nitrogen pool and atmospheric nitrogen deposition were the main sources for TN exported from the garden plot, forest and residential land, respectively. However, they were the main sources for TN exported both from the upland and paddy field. These results revealed that NPS pollution controlling rules should focus on the spatio-temporal distribution of NPS pollution sources.

Non-invasive three-dimension control of light between turbid layers using a surface quasi-point light source for precorrection.

PubMed

Qiao, Mu; Liu, Honglin; Pang, Guanghui; Han, Shensheng

2017-08-29

Manipulating light non-invasively through inhomogeneous media is an attractive goal in many disciplines. Wavefront shaping and optical phase conjugation can focus light to a point. Transmission matrix method can control light on multiple output modes simultaneously. Here we report a non-invasive approach which enables three-dimension (3D) light control between two turbid layers. A digital optical phase conjugation mirror measured and conjugated the diffused wavefront, which originated from a quasi-point source on the front turbid layer and passed through the back turbid layer. And then, because of memory effect, the phase-conjugated wavefront could be used as a carrier wave to transport a pre-calculated wavefront through the back turbid layer. The pre-calculated wavefront could project a desired 3D light field inside the sample, which, in our experiments, consisted of two 220-grid ground glass plates spaced by a 20 mm distance. The controllable range of light, according to the memory effect, was calculated to be 80 mrad in solid angle and 16 mm on z-axis. Due to the 3D light control ability, our approach may find applications in photodynamic therapy and optogenetics. Besides, our approach can also be combined with ghost imaging or compressed sensing to achieve 3D imaging between turbid layers.

Associations of diet quality with dairy group membership, membership duration and non-membership for Kenyan farm women and children: a comparative study.

PubMed

Walton, Colleen; Taylor, Jennifer; VanLeeuwen, John; Yeudall, Fiona; Mbugua, Samwel

2014-02-01

To examine associations among diet quality and dairy group membership, membership duration and non-member status for women and school-aged children in rural Kenya. A cross-sectional survey, using chain referral sampling, was conducted and diet quality indices and prevalence of inadequate intake (PII) were estimated using the 'estimated average requirement' cut-off point method from single 24 h recalls, using a Kenyan nutrient database. PII was compared among members and non-members and among membership-duration groups. Women and children of dairy group members (n 88), across membership-duration groups (1-3, 4-6, 7-9 and 10+ years), and non-members (n 23) living among members. Small farms in central Kenya. Members had higher energy, percentage of energy from animal-source foods and dietary diversity. Member women and children had lower PII for respectively seven and three of eleven micronutrients. Reduced PII for milk-source micronutrients was associated with membership duration for women. Many member women (38%) had inadequate vitamin A intake and 39% of member children had inadequate Zn intake. Members' PII was also high (>45%) for Fe, Ca and vitamin B12. A higher prevalence of being overweight among member women compared with non-member women suggested nutrition transition effects of higher farm productivity. Dairy group membership was positively associated with adequate quantity and quality of diets for women and children. Long-term membership was insufficient to address micronutrient deficiencies. Understanding and addressing barriers to better diet quality and strategies to mitigate negative nutrition transition effects are needed to optimize nutritional outcomes of dairy group membership.

TU-AB-BRC-11: Moving a GPU-OpenCL-Based Monte Carlo (MC) Dose Engine Towards Routine Clinical Use: Automatic Beam Commissioning and Efficient Source Sampling

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

Tian, Z; Folkerts, M; Jiang, S

Purpose: We have previously developed a GPU-OpenCL-based MC dose engine named goMC with built-in analytical linac beam model. To move goMC towards routine clinical use, we have developed an automatic beam-commissioning method, and an efficient source sampling strategy to facilitate dose calculations for real treatment plans. Methods: Our commissioning method is to automatically adjust the relative weights among the sub-sources, through an optimization process minimizing the discrepancies between calculated dose and measurements. Six models built for Varian Truebeam linac photon beams (6MV, 10MV, 15MV, 18MV, 6MVFFF, 10MVFFF) were commissioned using measurement data acquired at our institution. To facilitate dose calculationsmore » for real treatment plans, we employed inverse sampling method to efficiently incorporate MLC leaf-sequencing into source sampling. Specifically, instead of sampling source particles control-point by control-point and rejecting the particles blocked by MLC, we assigned a control-point index to each sampled source particle, according to MLC leaf-open duration of each control-point at the pixel where the particle intersects the iso-center plane. Results: Our auto-commissioning method decreased distance-to-agreement (DTA) of depth dose at build-up regions by 36.2% averagely, making it within 1mm. Lateral profiles were better matched for all beams, with biggest improvement found at 15MV for which root-mean-square difference was reduced from 1.44% to 0.50%. Maximum differences of output factors were reduced to less than 0.7% for all beams, with largest decrease being from1.70% to 0.37% found at 10FFF. Our new sampling strategy was tested on a Head&Neck VMAT patient case. Achieving clinically acceptable accuracy, the new strategy could reduce the required history number by a factor of ∼2.8 given a statistical uncertainty level and hence achieve a similar speed-up factor. Conclusion: Our studies have demonstrated the feasibility and effectiveness of our auto-commissioning approach and new efficient source sampling strategy, implying the potential of our GPU-based MC dose engine goMC for routine clinical use.« less

Optical and structural characterisation of epitaxial nanoporous GaN grown by CVD.

PubMed

Mena, Josué; Carvajal, Joan J; Martínez, Oscar; Jiménez, Juan; Zubialevich, Vitaly Z; Parbrook, Peter J; Diaz, Francesc; Aguiló, Magdalena

2017-09-15

In this paper we study the optical properties of nanoporous gallium nitride (GaN) epitaxial layers grown by chemical vapour deposition on non-porous GaN substrates, using photoluminescence, cathodoluminescence, and resonant Raman scattering, and correlate them with the structural characteristic of these films. We pay special attention to the analysis of the residual strain of the layers and the influence of the porosity in the light extraction. The nanoporous GaN epitaxial layers are under tensile strain, although the strain is progressively reduced as the deposition time and the thickness of the porous layer increases, becoming nearly strain free for a thickness of 1.7 μm. The analysis of the experimental data point to the existence of vacancy complexes as the main source of the tensile strain.

Reversing the pump dependence of a laser at an exceptional point

PubMed Central

Brandstetter, M.; Liertzer, M.; Deutsch, C.; Klang, P.; Schöberl, J.; Türeci, H. E.; Strasser, G.; Unterrainer, K.; Rotter, S.

2014-01-01

When two resonant modes in a system with gain or loss coalesce in both their resonance position and their width, a so-called exceptional point occurs, which acts as a source of non-trivial physics in a diverse range of systems. Lasers provide a natural setting to study such non-Hermitian degeneracies, as they feature resonant modes and a gain material as their basic constituents. Here we show that exceptional points can be conveniently induced in a photonic molecule laser by a suitable variation of the applied pump. Using a pair of coupled microdisk quantum cascade lasers, we demonstrate that in the vicinity of these exceptional points the coupled laser shows a characteristic reversal of its pump dependence, including a strongly decreasing intensity of the emitted laser light for increasing pump power. PMID:24925314

40 CFR 445.23 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS LANDFILLS POINT SOURCE CATEGORY RCRA Subtitle D Non-Hazardous Waste Landfill § 445.23 Effluent limitations representing the degree of effluent reduction attainable by the...

Environmental Education: Non-point Source Pollution

EPA Pesticide Factsheets

This activity is designed to demonstrate to students what an average storm drain collects during a rainfall event and how the water from storm drains can impact the water quality and aquatic environments of local streams, rivers, and bays.

Clinton River Sediment Transport Modeling Study

EPA Pesticide Factsheets

The U.S. ACE develops sediment transport models for tributaries to the Great Lakes that discharge to AOCs. The models developed help State and local agencies to evaluate better ways for soil conservation and non-point source pollution prevention.

Nearby Dwarf Stars: Duplicity, Binarity, and Masses

NASA Astrophysics Data System (ADS)

Mason, Brian D.; Hatkopf, William I.; Raghavan, Deepak

2008-02-01

Double stars have proven to be both a blessing and a curse for astronomers since their discovery over two centuries ago. They remain the only reliable source of masses, the most fundamental parameter defining stars. On the other hand, their sobriquet ``vermin of the sky'' is well-earned, due to the complications they present to both observers and theoreticians. These range from non-linear proper motions to stray light in detectors, to confusion in pointing of instruments due to non-symmetric point spread functions, to angular momentum conservation in multiple stars which results in binaries closer than allowed by evolution of two single stars. This proposal is an effort to address both their positive and negative aspects, through speckle interferometric observations, targeting ~1200 systems where useful information can be obtained with only a single additional observation. The proposed work will refine current statistics regarding duplicity (chance alignments of nearby point sources) and binarity (actual physical relationships), and improve the precisions and accuracies of stellar masses. Several targets support Raghavan's Ph.D. thesis, which is a comprehensive survey aimed at determining the multiplicity fraction among solar-type stars.

Nearby Dwarf Stars: Duplicity, Binarity, and Masses

NASA Astrophysics Data System (ADS)

Mason, Brian D.; Hartkopf, William I.; Raghavan, Deepak

2007-08-01

Double stars have proven to be both a blessing and a curse for astronomers since their discovery over two centuries ago. They remain the only reliable source of masses, the most fundamental parameter defining stars. On the other hand, their sobriquet ``vermin of the sky'' is well-earned, due to the complications they present to both observers and theoreticians. These range from non-linear proper motions to stray light in detectors, to confusion in pointing of instruments due to non-symmetric point spread functions, to angular momentum conservation in multiple stars which results in binaries closer than allowed by evolution of two single stars. This proposal is an effort to address both their positive and negative aspects, through speckle interferometric observations, targeting ~1200 systems where useful information can be obtained with only a single additional observation. The proposed work will refine current statistics regarding duplicity (chance alignments of nearby point sources) and binarity (actual physical relationships), and improve the precisions and accuracies of stellar masses. Several targets support Raghavan's Ph.D. thesis, which is a comprehensive survey aimed at determining the multiplicity fraction among solar-type stars.

Gravitational lensing by ring-like structures

NASA Astrophysics Data System (ADS)

Lake, Ethan; Zheng, Zheng

2017-02-01

We study a class of gravitational lensing systems consisting of an inclined ring/belt, with and without an added point mass at the centre. We show that a common feature of such systems are so-called pseudo-caustics, across which the magnification of a point source changes discontinuously and yet remains finite. Such a magnification change can be associated with either a change in image multiplicity or a sudden change in the size of a lensed image. The existence of pseudo-caustics and the complex interplay between them and the formal caustics (which correspond to points of infinite magnification) can lead to interesting consequences, such as truncated or open caustics and a non-conservation of total image parity. The origin of the pseudo-caustics is found to be the non-differentiability of the solutions to the lens equation across the ring/belt boundaries, with the pseudo-caustics corresponding to ring/belt boundaries mapped into the source plane. We provide a few illustrative examples to understand the pseudo-caustic features, and in a separate paper consider a specific astronomical application of our results to study microlensing by extrasolar asteroid belts.

[L-THIA-based management design for controlling urban non-point source pollution].

PubMed

Guo, Qing-Hai; Yang, Liu; Ke-Ming, Ma

2007-11-01

L-THIA Model was used to simulate the amounts of NPS pollutants in 2 catchments of Sanjiao watershed (Sj1, Sj2) in Hanyang district, and the total simulated amount of NPS loads in Sj1 and Sj2 were 1.82 x 10(4) kg, 1.38 x 10(5) kg, respectively. Based on the theory of resource-sink" and interaction of pattern with process, a series of BMPs, including green roof, grassland, porous pavement, infiltration trench, vegetative filter strip and wet pond, were optimized, and effects of BMPs were simulated along the surface runoff pathway. The results show that total pollutants outputs entering Sj1 and Sj2 account for 14.65% and 6.57%, respectively. Combining L-THIA model and BMPs in series is a proper measure for non-point source pollution control and urban development planning at watershed or region scale.

Isotopic Tracers for Delineating Non-Point Source Pollutants in Surface Water

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

Davisson, M L

2001-03-01

This study tested whether isotope measurements of surface water and dissolved constituents in surface water could be used as tracers of non-point source pollution. Oxygen-18 was used as a water tracer, while carbon-14, carbon-13, and deuterium were tested as tracers of DOC. Carbon-14 and carbon-13 were also used as tracers of dissolved inorganic carbon, and chlorine-36 and uranium isotopes were tested as tracers of other dissolved salts. In addition, large databases of water quality measurements were assembled for the Missouri River at St. Louis and the Sacramento-San Joaquin Delta in California to enhance interpretive results of the isotope measurements. Muchmore » of the water quality data has been under-interpreted and provides a valuable resource to investigative research, for which this report exploits and integrates with the isotope measurements.« less

Industrial pollution and the management of river water quality: a model of Kelani River, Sri Lanka.

PubMed

Gunawardena, Asha; Wijeratne, E M S; White, Ben; Hailu, Atakelty; Pandit, Ram

2017-08-19

Water quality of the Kelani River has become a critical issue in Sri Lanka due to the high cost of maintaining drinking water standards and the market and non-market costs of deteriorating river ecosystem services. By integrating a catchment model with a river model of water quality, we developed a method to estimate the effect of pollution sources on ambient water quality. Using integrated model simulations, we estimate (1) the relative contribution from point (industrial and domestic) and non-point sources (river catchment) to river water quality and (2) pollutant transfer coefficients for zones along the lower section of the river. Transfer coefficients provide the basis for policy analyses in relation to the location of new industries and the setting of priorities for industrial pollution control. They also offer valuable information to design socially optimal economic policy to manage industrialized river catchments.

Simulating the evolution of non-point source pollutants in a shallow water environment.

PubMed

Yan, Min; Kahawita, Rene

2007-03-01

Non-point source pollution originating from surface applied chemicals in either liquid or solid form as part of agricultural activities, appears in the surface runoff caused by rainfall. The infiltration and transport of these pollutants has a significant impact on subsurface and riverine water quality. The present paper describes the development of a unified 2-D mathematical model incorporating individual models for infiltration, adsorption, solubility rate, advection and diffusion, which significantly improve the current practice on mathematical modeling of pollutant evolution in shallow water. The governing equations have been solved numerically using cubic spline integration. Experiments were conducted at the Hydrodynamics Laboratory of the Ecole Polytechnique de Montreal to validate the mathematical model. Good correspondence between the computed results and experimental data has been obtained. The model may be used to predict the ultimate fate of surface applied chemicals by evaluating the proportions that are dissolved, infiltrated into the subsurface or are washed off.

3D transient electromagnetic simulation using a modified correspondence principle for wave and diffusion fields

NASA Astrophysics Data System (ADS)

Hu, Y.; Ji, Y.; Egbert, G. D.

2015-12-01

The fictitious time domain method (FTD), based on the correspondence principle for wave and diffusion fields, has been developed and used over the past few years primarily for marine electromagnetic (EM) modeling. Here we present results of our efforts to apply the FTD approach to land and airborne TEM problems which can reduce the computer time several orders of magnitude and preserve high accuracy. In contrast to the marine case, where sources are in the conductive sea water, we must model the EM fields in the air; to allow for topography air layers must be explicitly included in the computational domain. Furthermore, because sources for most TEM applications generally must be modeled as finite loops, it is useful to solve directly for the impulse response appropriate to the problem geometry, instead of the point-source Green functions typically used for marine problems. Our approach can be summarized as follows: (1) The EM diffusion equation is transformed to a fictitious wave equation. (2) The FTD wave equation is solved with an explicit finite difference time-stepping scheme, with CPML (Convolutional PML) boundary conditions for the whole computational domain including the air and earth , with FTD domain source corresponding to the actual transmitter geometry. Resistivity of the air layers is kept as low as possible, to compromise between efficiency (longer fictitious time step) and accuracy. We have generally found a host/air resistivity contrast of 10-3 is sufficient. (3)A "Modified" Fourier Transform (MFT) allow us recover system's impulse response from the fictitious time domain to the diffusion (frequency) domain. (4) The result is multiplied by the Fourier transformation （FT） of the real source current avoiding time consuming convolutions in the time domain. (5) The inverse FT is employed to get the final full waveform and full time response of the system in the time domain. In general, this method can be used to efficiently solve most time-domain EM simulation problems for non-point sources.

Removal of non-point source pollutants from domestic sewage and agricultural runoff by vegetated drainage ditches (VDDs): Design, mechanism, management strategies, and future directions.

PubMed

Nsenga Kumwimba, Mathieu; Meng, Fangang; Iseyemi, Oluwayinka; Moore, Matthew T; Zhu, Bo; Tao, Wang; Liang, Tang Jia; Ilunga, Lunda

2018-10-15

Domestic wastewater and agricultural runoff are increasingly viewed as major threats to both aquatic and terrestrial ecosystems due to the introduction of non-point source inorganic (e.g., nitrogen, phosphorus and metals) and organic (e.g., pesticides and pharmaceutical residues) pollutants. With rapid economic growth and social change in rural regions, it is important to examine the treatment systems in rural and remote areas for high efficiency, low running costs, and minimal maintenance in order to minimize its influence on water bodies and biodiversity. Recently, the use of vegetated drainage ditches (VDDs) has been employed in treatment of domestic sewage and agricultural runoff, but information on the performance of VDDs for treating these pollutants with various new management practices is still not sufficiently summarized. This paper aims to outline and review current knowledge related to the use of VDDs in mitigating these pollutants from domestic sewage and agricultural runoff. Literature analysis has suggested that further research should be carried out to improve ditch characteristics and management strategies inside ditches in order to ensure their effectiveness. Firstly, the reported major ditch characteristics with the most effect on pollutant removal processes (e.g., plant species, weirs, biofilms, and substrates selection) were summarized. The second focus concerns the function of ditch characteristics in VDDs for pollutant removal and identification of possible removal mechanisms involved. Thirdly, we examined factors to consider for establishing appropriate management strategies within ditches and how these could influence the whole ditch design process. The current review promotes areas where future research is needed and highlights clear and sufficient evidence regarding performance and application of this overlooked ditch system to reduce pollutants. Copyright © 2018 Elsevier B.V. All rights reserved.

A conceptual study on the formulation of a permeable reactive pavement with activated carbon additives for controlling the fate of non-point source environmental organic contaminants.

PubMed

Huang, Shengyi; Liang, Chenju

2018-02-01

To take advantage of the road pavement network where non-point source (NPS) pollution such as benzene, toluene, ethyl-benzene, and xylene (BTEX) from vehicle traffic exhaust via wet and dry atmospheric deposition occurs, the asphalt pavement may be used as a media to control the NPS pollution. An experiment to prepare an adsorptive porous reactive pavement (PRP) was initiated to explore the potential to reduce environmental NPS vehicle pollution. The PRP was prepared and studied as follows: various activated carbons (AC) were initially screened to determine if they were suitable as an additive in the porous asphalt mixture; various mixtures of a selected AC were incorporated with the design of porous asphalt concrete (PAC) to produce PRP, and the PRP formulations were tested to ensure that they comply with the required specifications; qualified specimens were subsequently tested to determine their adsorption capacity for BTEX in aqueous solution, as compared to conventional PAC. The PRP08 and PRP16 samples, named for the design formulations of 0.8% and 1.6% of AC (by wt. in the formulation), exhibited low asphalt drain-down and low abrasion loss and also met all regulated specifications. The BTEX adsorption capacity measurements of PRP08 and PRP16 were 33-46%, 36-51%, 20-22%, and 6-8% respectively, higher than those obtained from PACs. Based on the test results, PRPs showed good physical performance and adsorption and may be considered as a potential method for controlling the transport of NPS vehicle pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessing the effects of rural livelihood transition on non-point source pollution: a coupled ABM-IECM model.

PubMed

Yuan, Chengcheng; Liu, Liming; Ye, Jinwei; Ren, Guoping; Zhuo, Dong; Qi, Xiaoxing

2017-05-01

Water pollution caused by anthropogenic activities and driven by changes in rural livelihood strategies in an agricultural system has received increasing attention in recent decades. To simulate the effects of rural household livelihood transition on non-point source (NPS) pollution, a model combining an agent-based model (ABM) and an improved export coefficient model (IECM) was developed. The ABM was adopted to simulate the dynamic process of household livelihood transition, and the IECM was employed to estimate the effects of household livelihood transition on NPS pollution. The coupled model was tested in a small catchment in the Dongting Lake region, China. The simulated results reveal that the transition of household livelihood strategies occurred with the changes in the prices of rice, pig, and labor. Thus, the cropping system, land-use intensity, resident population, and number of pigs changed in the small catchment from 2000 to 2014. As a result of these changes, the total nitrogen load discharged into the river initially increased from 6841.0 kg in 2000 to 8446.3 kg in 2004 and then decreased to 6063.9 kg in 2014. Results also suggest that rural living, livestock, paddy field, and precipitation alternately became the main causes of NPS pollution in the small catchment, and the midstream region of the small catchment was the primary area for NPS pollution from 2000 to 2014. Despite some limitations, the coupled model provides an innovative way to simulate the effects of rural household livelihood transition on NPS pollution with the change of socioeconomic factors, and thereby identify the key factors influencing water pollution to provide valuable suggestions on how agricultural environmental risks can be reduced through the regulation of the behaviors of farming households in the future.

Using the example of Istanbul to outline general aspects of protecting reservoirs, rivers and lakes used for drinking water abstraction.

PubMed

Tanik, A

2000-01-01

The six main drinking water reservoirs of Istanbul are under the threat of pollution due to rapid population increase, unplanned urbanisation and insufficient infrastructure. In contrast to the present land use profile, the environmental evaluation of the catchment areas reveals that point sources of pollutants, especially of domestic origin, dominate over those from diffuse sources. The water quality studies also support these findings, emphasising that if no substantial precautions are taken, there will be no possibility of obtaining drinking water from them. In this paper, under the light of the present status of the reservoirs, possible and probable short- and long-term protective measures are outlined for reducing the impact of point sources. Immediate precautions mostly depend on reducing the pollution arising from the existing settlements. Long-term measures mainly emphasise the preparation of new land use plans taking into consideration the protection of unoccupied lands. Recommendations on protection and control of the reservoirs are stated.

40 CFR 425.30 - Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the hair save or pulp, non-chrome tan, retan-wet finish subcategory. 425.30 Section 425.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY Hair Save...

An improved instrument for the in vivo detection of lead in bone.

PubMed Central

Gordon, C L; Chettle, D R; Webber, C E

1993-01-01

An improved instrument for the fluorescence excitation measurement of concentrations of lead in bone has been developed. This is based on a large area high purity germanium detector and a point source of 109Cd. The source is positioned in a tungsten shield at the centre of the detector face such that 88keV photons cannot enter the detector directly. In vivo measurements are calibrated with plaster of Paris phantoms. Occupationally non-exposed men show a minimum detectable concentration of about 6 micrograms/g bone mineral. Measurements of tibia lead concentrations in 30 non-occupationally exposed men between the ages of 23 and 73 showed an annual increment of 0.46 microgram/g bone mineral/year. The mean deviation from the regression of tibia lead upon age was 3.5 micrograms/g bone mineral. Tibia lead concentration in one subject with a history of exposure to lead was 69.6 (SD 3.5) micrograms/g bone mineral. The improved precision of the point source large detector system means that greater confidence can be placed on the results of in vivo measurements of lead concentration. This will allow studies of the natural history of non-occupational lead accumulation in normal subjects and should permit investigations of the efficacy of therapeutic interventions in subjects poisoned with lead. PMID:8343425

Modeling susceptibility difference artifacts produced by metallic implants in magnetic resonance imaging with point-based thin-plate spline image registration.

PubMed

Pauchard, Y; Smith, M; Mintchev, M

2004-01-01

Magnetic resonance imaging (MRI) suffers from geometric distortions arising from various sources. One such source are the non-linearities associated with the presence of metallic implants, which can profoundly distort the obtained images. These non-linearities result in pixel shifts and intensity changes in the vicinity of the implant, often precluding any meaningful assessment of the entire image. This paper presents a method for correcting these distortions based on non-rigid image registration techniques. Two images from a modelled three-dimensional (3D) grid phantom were subjected to point-based thin-plate spline registration. The reference image (without distortions) was obtained from a grid model including a spherical implant, and the corresponding test image containing the distortions was obtained using previously reported technique for spatial modelling of magnetic susceptibility artifacts. After identifying the nonrecoverable area in the distorted image, the calculated spline model was able to quantitatively account for the distortions, thus facilitating their compensation. Upon the completion of the compensation procedure, the non-recoverable area was removed from the reference image and the latter was compared to the compensated image. Quantitative assessment of the goodness of the proposed compensation technique is presented.

Determination of flash point in air and pure oxygen using an equilibrium closed bomb apparatus.

PubMed

Kong, Dehong; am Ende, David J; Brenek, Steven J; Weston, Neil P

2003-08-29

The standard closed testers for flash point measurements may not be feasible for measuring flash point in special atmospheres like oxygen because the test atmosphere cannot be maintained due to leakage and the laboratory safety can be compromised. To address these limitations we developed a new "equilibrium closed bomb" (ECB). The ECB generally gives lower flash point values than standard closed cup testers as shown by the results of six flammable liquids. The present results are generally in good agreement with the values calculated from the reported lower flammability limits and the vapor pressures. Our measurements show that increased oxygen concentration had little effect on the flash points of the tested flammable liquids. While generally regarded as non-flammable because of the lack of observed flash point in standard closed cup flash point testers, dichloromethane is known to form flammable mixtures. The flash point of dichloromethane in oxygen measured in the ECB is -7.1 degrees C. The flash point of dichloromethane in air is dependent on the type and energy of the ignition source. Further research is being carried out to establish the relationship between the flash point of dichloromethane and the energy of the ignition source.

Trophic coupling between two adjacent benthic food webs within a man-made intertidal area: A stable isotopes evidence

NASA Astrophysics Data System (ADS)

Schaal, Gauthier; Riera, Pascal; Leroux, Cédric

2008-04-01

This study aimed at establishing the effects of human-made physical modifications on the trophic structure and functioning of an intertidal benthic food web in Arcachon Bay (France). The main food sources and the most representative consumers were sampled on an artificial rocky dyke and its adjacent seagrass meadow. The food sources of consumers were inferred through the use of carbon and nitrogen stable isotopes. The contributions of the different food sources to the diets of the consumers were established using the Isosource mixing model. In order to reduce the range of feasible contributions, additional non-isotopic constraints were added when necessary to the outputs of this model. We observed a more complex food web than previously shown for artificial habitats. Moreover, it appears that several consumers inhabiting the artificial environment base most of their diet on allochtonous eelgrass-derived detritus. In turn, several consumers inhabiting the eelgrass meadow consumed significantly macroalgae-derived material originating from the adjacent artificial rocky area. These results point out that the food webs associated to adjacent habitats can influence each other through the utilisation of exported organic matter.

Direction of Magnetoencephalography Sources Associated with Feedback and Feedforward Contributions in a Visual Object Recognition Task

PubMed Central

Ahlfors, Seppo P.; Jones, Stephanie R.; Ahveninen, Jyrki; Hämäläinen, Matti S.; Belliveau, John W.; Bar, Moshe

2014-01-01

Identifying inter-area communication in terms of the hierarchical organization of functional brain areas is of considerable interest in human neuroimaging. Previous studies have suggested that the direction of magneto- and electroencephalography (MEG, EEG) source currents depends on the layer-specific input patterns into a cortical area. We examined the direction in MEG source currents in a visual object recognition experiment in which there were specific expectations of activation in the fusiform region being driven by either feedforward or feedback inputs. The source for the early non-specific visual evoked response, presumably corresponding to feedforward driven activity, pointed outward, i.e., away from the white matter. In contrast, the source for the later, object-recognition related signals, expected to be driven by feedback inputs, pointed inward, toward the white matter. Associating specific features of the MEG/EEG source waveforms to feedforward and feedback inputs could provide unique information about the activation patterns within hierarchically organized cortical areas. PMID:25445356

EPA Office of Water (OW): 2002 SPARROW Total NP (Catchments)

EPA Pesticide Factsheets

SPARROW (SPAtially Referenced Regressions On Watershed attributes) is a watershed modeling tool with output that allows the user to interpret water quality monitoring data at the regional and sub-regional scale. The model relates in-stream water-quality measurements to spatially referenced characteristics of watersheds, including pollutant sources and environmental factors that affect rates of pollutant delivery to streams from the land and aquatic, in-stream processing . The core of the model consists of a nonlinear regression equation describing the non-conservative transport of contaminants from point and non-point (or ??diffuse??) sources on land to rivers and through the stream and river network. SPARROW estimates contaminant concentrations, loads (or ??mass,?? which is the product of concentration and streamflow), and yields in streams (mass of nitrogen and of phosphorus entering a stream per acre of land). It empirically estimates the origin and fate of contaminants in streams and receiving bodies, and quantifies uncertainties in model predictions. The model predictions are illustrated through detailed maps that provide information about contaminant loadings and source contributions at multiple scales for specific stream reaches, basins, or other geographic areas.

Common radiation analysis model for 75,000 pound thrust NERVA engine (1137400E)

NASA Technical Reports Server (NTRS)

Warman, E. A.; Lindsey, B. A.

1972-01-01

The mathematical model and sources of radiation used for the radiation analysis and shielding activities in support of the design of the 1137400E version of the 75,000 lbs thrust NERVA engine are presented. The nuclear subsystem (NSS) and non-nuclear components are discussed. The geometrical model for the NSS is two dimensional as required for the DOT discrete ordinates computer code or for an azimuthally symetrical three dimensional Point Kernel or Monte Carlo code. The geometrical model for the non-nuclear components is three dimensional in the FASTER geometry format. This geometry routine is inherent in the ANSC versions of the QAD and GGG Point Kernal programs and the COHORT Monte Carlo program. Data are included pertaining to a pressure vessel surface radiation source data tape which has been used as the basis for starting ANSC analyses with the DASH code to bridge into the COHORT Monte Carlo code using the WANL supplied DOT angular flux leakage data. In addition to the model descriptions and sources of radiation, the methods of analyses are briefly described.

Proceedings from the Workshop on Research Needs for Assessment and Management of Non-Point Air Emissions from Department of Defense Activities held in Research Triangle Park, North Carolina on 19-21 February 2008

DTIC Science & Technology

2008-10-01

Chow, J.C. (2006). Feasibility of soil dust source apportionment by the pyrolysis-gas chromatography/mass spectrometry method. J. Air Waste Manage...receptor-oriented source apportionment models. • Develop monitoring methods to determine source and fence line amounts of fugitive dust emissions for...offsite impact, including evaluation with receptor- oriented source apportionment models 76 8.8.1 Background 76 8.8.2 Significance 77 8.8.3

Single-Point Attachment Wind Damper for Launch Vehicle On-Pad Motion

NASA Technical Reports Server (NTRS)

Hrinda, Glenn A.

2009-01-01

A single-point-attachment wind-damper device is proposed to reduce on-pad motion of a cylindrical launch vehicle. The device is uniquely designed to attach at only one location along the vehicle and capable of damping out wind gusts from any lateral direction. The only source of damping is from two viscous dampers in the device. The effectiveness of the damper design in reducing vehicle displacements is determined from transient analysis results using an Ares I-X launch vehicle. Combinations of different spring stiffnesses and damping are used to show how the vehicle's displacement response is significantly reduced during a wind gust.

Estimating population exposure to ambient polycyclic aromatic hydrocarbon in the United States - Part II: Source apportionment and cancer risk assessment.

PubMed

Zhang, Jie; Wang, Peng; Li, Jingyi; Mendola, Pauline; Sherman, Seth; Ying, Qi

2016-12-01

A revised Community Multiscale Air Quality (CMAQ) model was developed to simulate the emission, reactions, transport, deposition and gas-to-particle partitioning processes of 16 priority polycyclic aromatic hydrocarbons (PAHs), as described in Part I of the two-part series. The updated CMAQ model was applied in this study to quantify the contributions of different emission sources to the predicted PAH concentrations and excess cancer risk in the United States (US) in 2011. The cancer risk in the continental US due to inhalation exposure of outdoor naphthalene (NAPH) and seven larger carcinogenic PAHs (cPAHs) was predicted to be significant. The incremental lifetime cancer risk (ILCR) exceeds 1×10 -5 in many urban and industrial areas. Exposure to PAHs was estimated to result in 5704 (608-10,800) excess lifetime cancer cases. Point sources not related with energy generation and the oil and gas processes account for approximately 31% of the excess cancer cases, followed by non-road engines with 18.6% contributions. Contributions of residential wood combustion (16.2%) are similar to that of transportation-related sources (mostly motor vehicles with small contributions from railway and marine vessels; 13.4%). The oil and gas industry emissions, although large contributors to high concentrations of cPAHs regionally, are only responsible of 4.3% of the excess cancer cases, which is similar to the contributions of non-US sources (6.8%) and non-point sources (7.2%). The power generation units pose the most minimal impact on excess cancer risk, with contributions of approximately 2.3%. Copyright © 2016 Elsevier Ltd. All rights reserved.

Early-type galaxies: Automated reduction and analysis of ROSAT PSPC data

NASA Technical Reports Server (NTRS)

Mackie, G.; Fabbiano, G.; Harnden, F. R., Jr.; Kim, D.-W.; Maggio, A.; Micela, G.; Sciortino, S.; Ciliegi, P.

1996-01-01

Preliminary results of early-type galaxies that will be part of a galaxy catalog to be derived from the complete Rosat data base are presented. The stored data were reduced and analyzed by an automatic pipeline. This pipeline is based on a command language scrip. The important features of the pipeline include new data time screening in order to maximize the signal to noise ratio of faint point-like sources, source detection via a wavelet algorithm, and the identification of sources with objects from existing catalogs. The pipeline outputs include reduced images, contour maps, surface brightness profiles, spectra, color and hardness ratios.

Reducing errors in aircraft atmospheric inversion estimates of point-source emissions: the Aliso Canyon natural gas leak as a natural tracer experiment

NASA Astrophysics Data System (ADS)

Gourdji, S. M.; Yadav, V.; Karion, A.; Mueller, K. L.; Conley, S.; Ryerson, T.; Nehrkorn, T.; Kort, E. A.

2018-04-01

Urban greenhouse gas (GHG) flux estimation with atmospheric measurements and modeling, i.e. the ‘top-down’ approach, can potentially support GHG emission reduction policies by assessing trends in surface fluxes and detecting anomalies from bottom-up inventories. Aircraft-collected GHG observations also have the potential to help quantify point-source emissions that may not be adequately sampled by fixed surface tower-based atmospheric observing systems. Here, we estimate CH4 emissions from a known point source, the Aliso Canyon natural gas leak in Los Angeles, CA from October 2015–February 2016, using atmospheric inverse models with airborne CH4 observations from twelve flights ≈4 km downwind of the leak and surface sensitivities from a mesoscale atmospheric transport model. This leak event has been well-quantified previously using various methods by the California Air Resources Board, thereby providing high confidence in the mass-balance leak rate estimates of (Conley et al 2016), used here for comparison to inversion results. Inversions with an optimal setup are shown to provide estimates of the leak magnitude, on average, within a third of the mass balance values, with remaining errors in estimated leak rates predominantly explained by modeled wind speed errors of up to 10 m s‑1, quantified by comparing airborne meteorological observations with modeled values along the flight track. An inversion setup using scaled observational wind speed errors in the model-data mismatch covariance matrix is shown to significantly reduce the influence of transport model errors on spatial patterns and estimated leak rates from the inversions. In sum, this study takes advantage of a natural tracer release experiment (i.e. the Aliso Canyon natural gas leak) to identify effective approaches for reducing the influence of transport model error on atmospheric inversions of point-source emissions, while suggesting future potential for integrating surface tower and aircraft atmospheric GHG observations in top-down urban emission monitoring systems.

Impacts of drought on the quality of surface water of the basin

NASA Astrophysics Data System (ADS)

Huang, B. B.; Yan, D. H.; Wang, H.; Cheng, B. F.; Cui, X. H.

2013-11-01

Under the background of climate change and human's activities, there has been presenting an increase both in the frequency of droughts and the range of their impacts. Droughts may give rise to a series of resources, environmental and ecological effects, i.e. water shortage, water quality deterioration as well as the decrease in the diversity of aquatic organisms. This paper, above all, identifies the impact mechanism of drought on the surface water quality of the basin, and then systematically studies the laws of generation, transfer, transformation and degradation of pollutants during the drought, finding out that the alternating droughts and floods stage is the critical period during which the surface water quality is affected. Secondly, through employing indoor orthogonality experiments, serving drought degree, rainfall intensity and rainfall duration as the main elements and designing various scenario models, the study inspects the effects of various factors on the nitrogen loss in soil as well as the loss of non-point sources pollution and the leaching rate of nitrogen under the different alternating scenarios of drought and flood. It comes to the conclusion that the various factors and the loss of non-point source pollution are positively correlated, and under the alternating scenarios of drought and flood, there is an exacerbation in the loss of ammonium nitrogen and nitrate nitrogen in soil, which generates the transfer and transformation mechanisms of non-point source pollution from a micro level. Finally, by employing the data of Nenjiang river basin, the paper assesses the impacts of drought on the surface water quality from a macro level.

Distinguishing one from many using super-resolution compressive sensing

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

Anthony, Stephen Michael; Mulcahy-Stanislawczyk, Johnathan; Shields, Eric A.

We present that distinguishing whether a signal corresponds to a single source or a limited number of highly overlapping point spread functions (PSFs) is a ubiquitous problem across all imaging scales, whether detecting receptor-ligand interactions in cells or detecting binary stars. Super-resolution imaging based upon compressed sensing exploits the relative sparseness of the point sources to successfully resolve sources which may be separated by much less than the Rayleigh criterion. However, as a solution to an underdetermined system of linear equations, compressive sensing requires the imposition of constraints which may not always be valid. One typical constraint is that themore » PSF is known. However, the PSF of the actual optical system may reflect aberrations not present in the theoretical ideal optical system. Even when the optics are well characterized, the actual PSF may reflect factors such as non-uniform emission of the point source (e.g. fluorophore dipole emission). As such, the actual PSF may differ from the PSF used as a constraint. Similarly, multiple different regularization constraints have been suggested including the l 1-norm, l 0-norm, and generalized Gaussian Markov random fields (GGMRFs), each of which imposes a different constraint. Other important factors include the signal-to-noise ratio of the point sources and whether the point sources vary in intensity. In this work, we explore how these factors influence super-resolution image recovery robustness, determining the sensitivity and specificity. In conclusion, we determine an approach that is more robust to the types of PSF errors present in actual optical systems.« less

Distinguishing one from many using super-resolution compressive sensing

DOE PAGES

Anthony, Stephen Michael; Mulcahy-Stanislawczyk, Johnathan; Shields, Eric A.; ...

2018-05-14

We present that distinguishing whether a signal corresponds to a single source or a limited number of highly overlapping point spread functions (PSFs) is a ubiquitous problem across all imaging scales, whether detecting receptor-ligand interactions in cells or detecting binary stars. Super-resolution imaging based upon compressed sensing exploits the relative sparseness of the point sources to successfully resolve sources which may be separated by much less than the Rayleigh criterion. However, as a solution to an underdetermined system of linear equations, compressive sensing requires the imposition of constraints which may not always be valid. One typical constraint is that themore » PSF is known. However, the PSF of the actual optical system may reflect aberrations not present in the theoretical ideal optical system. Even when the optics are well characterized, the actual PSF may reflect factors such as non-uniform emission of the point source (e.g. fluorophore dipole emission). As such, the actual PSF may differ from the PSF used as a constraint. Similarly, multiple different regularization constraints have been suggested including the l 1-norm, l 0-norm, and generalized Gaussian Markov random fields (GGMRFs), each of which imposes a different constraint. Other important factors include the signal-to-noise ratio of the point sources and whether the point sources vary in intensity. In this work, we explore how these factors influence super-resolution image recovery robustness, determining the sensitivity and specificity. In conclusion, we determine an approach that is more robust to the types of PSF errors present in actual optical systems.« less

A comparison of speciated atmospheric mercury at an urban center and an upwind rural location

USGS Publications Warehouse

Rutter, A.P.; Schauer, J.J.; Lough, G.C.; Snyder, D.C.; Kolb, C.J.; Von Klooster, S.; Rudolf, T.; Manolopoulos, H.; Olson, M.L.

2008-01-01

Gaseous elemental mercury (GEM), particulate mercury (PHg) and reactive gaseous mercury (RGM) were measured every other hour at a rural location in south central Wisconsin (Devil's Lake State Park, WI, USA) between April 2003 and March 2004, and at a predominantly downwind urban site in southeastern Wisconsin (Milwaukee, WI, USA) between June 2004 and May 2005. Annual averages of GEM, PHg, and RGM at the urban site were statistically higher than those measured at the rural site. Pollution roses of GEM and reactive mercury (RM; sum of PHg and RGM) at the rural and urban sites revealed the influences of point source emissions in surrounding counties that were consistent with the US EPA 1999 National Emission Inventory and the 2003-2005 US EPA Toxics Release Inventory. Source-receptor relationships at both sites were studied by quantifying the impacts of point sources on mercury concentrations. Time series of GEM, PHg, and RGM concentrations were sorted into two categories; time periods dominated by impacts from point sources, and time periods dominated by mercury from non-point sources. The analysis revealed average point source contributions to GEM, PHg, and RGM concentration measurements to be significant over the year long studies. At the rural site, contributions to annual average concentrations were: GEM (2%; 0.04 ng m-3); and, RM (48%; 5.7 pg m-3). At the urban site, contributions to annual average concentrations were: GEM (33%; 0.81 ng m-3); and, RM (64%; 13.8 pg m-3). ?? The Royal Society of Chemistry.

Gallium nitride light sources for optical coherence tomography

NASA Astrophysics Data System (ADS)

Goldberg, Graham R.; Ivanov, Pavlo; Ozaki, Nobuhiko; Childs, David T. D.; Groom, Kristian M.; Kennedy, Kenneth L.; Hogg, Richard A.

2017-02-01

The advent of optical coherence tomography (OCT) has permitted high-resolution, non-invasive, in vivo imaging of the eye, skin and other biological tissue. The axial resolution is limited by source bandwidth and central wavelength. With the growing demand for short wavelength imaging, super-continuum sources and non-linear fibre-based light sources have been demonstrated in tissue imaging applications exploiting the near-UV and visible spectrum. Whilst the potential has been identified of using gallium nitride devices due to relative maturity of laser technology, there have been limited reports on using such low cost, robust devices in imaging systems. A GaN super-luminescent light emitting diode (SLED) was first reported in 2009, using tilted facets to suppress lasing, with the focus since on high power, low speckle and relatively low bandwidth applications. In this paper we discuss a method of producing a GaN based broadband source, including a passive absorber to suppress lasing. The merits of this passive absorber are then discussed with regards to broad-bandwidth applications, rather than power applications. For the first time in GaN devices, the performance of the light sources developed are assessed though the point spread function (PSF) (which describes an imaging systems response to a point source), calculated from the emission spectra. We show a sub-7μm resolution is possible without the use of special epitaxial techniques, ultimately outlining the suitability of these short wavelength, broadband, GaN devices for use in OCT applications.

Ammonia emissions from non-agricultural sources in the UK

NASA Astrophysics Data System (ADS)

Sutton, M. A.; Dragosits, U.; Tang, Y. S.; Fowler, D.

A detailed literature review has been undertaken of the magnitude of non-agricultural sources of ammonia (NH 3) in the United Kingdom. Key elements of the work included estimation of nitrogen (N) excreted by different sources (birds, animals, babies, human sweat), review of miscellaneous combustion sources, as well as identification of industrial sources and use of NH 3 as a solvent. Overall the total non-agricultural emission of NH 3 from the UK in 1996 is estimated here as 54 (27-106) kt NH 3-N yr -1, although this includes 11 (6-23) kt yr -1 from agriculture related sources (sewage sludge spreading, biomass burning and agro-industry). Compared with previous estimates for 1990, component source magnitudes have changed both because of revised average emissions per source unit (emission factors) and changes in the source activity between 1990 and 1996. Sources with larger average emission factors than before include horses, wild animals and sea bird colonies, industry, sugar beet processing, household products and non-agricultural fertilizer use, with the last three sources being included for the first time. Sources with smaller emission factors than before include: land spreading of sewage sludge, direct human emissions (sweat, breath, smoking, infants), pets (cats and dogs) and fertilizer manufacture. Between 1990 and 1996 source activities increased for sewage spreading (due to reduced dumping at sea) and transport (due to increased use of catalytic converters), but decreased for coal combustion. Combined with the current UK estimates of agricultural NH 3 emissions of 229 kt N yr -1 (1996), total UK NH 3 emissions are estimated at 283 kt N yr -1. Allowing for an import of reduced nitrogen (NH x) of 30 kt N yr -1 and deposition of 230 kt N yr -1, these figures imply an export of 83 kt NH 3-N yr -1. Although export is larger than previously estimated, due to the larger contribution of non-agricultural NH 3 emissions, it is still insufficient to balance the UK budget, for which around 150 kt NH 3-N are estimated to be exported. The shortfall in the budget is, nevertheless, well within the range of uncertainty of the total emissions.

Renewable Energy Can Help Reduce Oil Dependency

ScienceCinema

Arvizu, Dan

2017-12-21

In a speech to the Economic Club of Kansas City on June 23, 2010, NREL Director Dan Arvizu takes a realistic look at how renewable energy can help reduce America's dependence on oil, pointing out that the country gets as much energy from renewable sources now as it does from offshore oil production.

40 CFR 425.50 - Applicability; description of the no beamhouse subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY No... cattle hides, sheepskins, or splits (hair previously removed and pickled) into finished leather by chrome or non-chrome tanning, and retan-wet finishing. ...

40 CFR 408.93 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 29 2011-07-01 2009-07-01 true [Reserved] 408.93 Section 408.93 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing...

40 CFR 408.93 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true [Reserved] 408.93 Section 408.93 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing...

IMPERVIOUS SURFACE RESEARCH IN THE MID-ATLANTIC

EPA Science Inventory

Anthropogenic impervious surfaces have an important relationship with non-point source pollution (NPS) in urban watersheds. These human-created surfaces include such features as roads, parking lots, rooftops, sidewalks, and driveways. The amount of impervious surface area in a ...

Occurrence, source and ecological assessment of baseline hydrocarbons in the intertidal marine sediments along the shoreline of Douglas Channel to Hecate Strait in British Columbia.

PubMed

Yang, Zeyu; Hollebone, Bruce P; Laforest, Sonia; Lambert, Patrick; Brown, Carl E; Yang, Chun; Shah, Keval; Landriault, Mike; Goldthorp, Michael

2017-09-15

The occurrence, source and ecological assessment of baseline hydrocarbons in the intertidal zone along the northern British shoreline were evaluated based on analyzing total petroleum hydrocarbons (TPH), n-alkanes, petroleum related biomarkers such as terpanes and steranes, and polycyclic aromatic hydrocarbons (PAHs) including non-alkylated and alkylated homologues (APAHs). The TPH levels, n-alkanes, petroleum biomarkers and PAHs in all the sampling sites, except for Masset Harbor/York Point at Gil Island were low, without obvious unresolved complex mixture (UCM) and petroleum contamination input. Specifically, n-alkanes showed a major terrestrial plants input; PAHs with abundant non-alkylated PAHs but minor APAHs showed a major pyrogenic input. However, obvious petroleum-derived hydrocarbons have impacted Masset Harbor. A historical petroleum input was found in York Point at Gil Island, due to the presence of the low level of petroleum biomarkers. Ecological assessment of 13 non-alkylated PAHs in Masset Harbor indicated no potential toxicity to the benthic organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Catchment-wide impacts on water quality: the use of 'snapshot' sampling during stable flow

NASA Astrophysics Data System (ADS)

Grayson, R. B.; Gippel, C. J.; Finlayson, B. L.; Hart, B. T.

1997-12-01

Water quality is usually monitored on a regular basis at only a small number of locations in a catchment, generally focused at the catchment outlet. This integrates the effect of all the point and non-point source processes occurring throughout the catchment. However, effective catchment management requires data which identify major sources and processes. As part of a wider study aimed at providing technical information for the development of integrated catchment management plans for a 5000 km 2 catchment in south eastern Australia, a 'snapshot' of water quality was undertaken during stable summer flow conditions. These low flow conditions exist for long periods so water quality at these flow levels is an important constraint on the health of in-stream biological communities. Over a 4 day period, a study of the low flow water quality characteristics throughout the Latrobe River catchment was undertaken. Sixty-four sites were chosen to enable a longitudinal profile of water quality to be established. All tributary junctions and sites along major tributaries, as well as all major industrial inputs were included. Samples were analysed for a range of parameters including total suspended solids concentration, pH, dissolved oxygen, electrical conductivity, turbidity, flow rate and water temperature. Filtered and unfiltered samples were taken from 27 sites along the main stream and tributary confluences for analysis of total N, NH 4, oxidised N, total P and dissolved reactive P concentrations. The data are used to illustrate the utility of this sampling methodology for establishing specific sources and estimating non-point source loads of phosphorous, total suspended solids and total dissolved solids. The methodology enabled several new insights into system behaviour including quantification of unknown point discharges, identification of key in-stream sources of suspended material and the extent to which biological activity (phytoplankton growth) affects water quality. The costs and benefits of the sampling exercise are reviewed.

AN IMAGE-PLANE ALGORITHM FOR JWST'S NON-REDUNDANT APERTURE MASK DATA

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

Greenbaum, Alexandra Z.; Pueyo, Laurent; Sivaramakrishnan, Anand

2015-01-10

The high angular resolution technique of non-redundant masking (NRM) or aperture masking interferometry (AMI) has yielded images of faint protoplanetary companions of nearby stars from the ground. AMI on James Webb Space Telescope (JWST)'s Near Infrared Imager and Slitless Spectrograph (NIRISS) has a lower thermal background than ground-based facilities and does not suffer from atmospheric instability. NIRISS AMI images are likely to have 90%-95% Strehl ratio between 2.77 and 4.8 μm. In this paper we quantify factors that limit the raw point source contrast of JWST NRM. We develop an analytic model of the NRM point spread function which includesmore » different optical path delays (pistons) between mask holes and fit the model parameters with image plane data. It enables a straightforward way to exclude bad pixels, is suited to limited fields of view, and can incorporate effects such as intra-pixel sensitivity variations. We simulate various sources of noise to estimate their effect on the standard deviation of closure phase, σ{sub CP} (a proxy for binary point source contrast). If σ{sub CP} < 10{sup –4} radians—a contrast ratio of 10 mag—young accreting gas giant planets (e.g., in the nearby Taurus star-forming region) could be imaged with JWST NIRISS. We show the feasibility of using NIRISS' NRM with the sub-Nyquist sampled F277W, which would enable some exoplanet chemistry characterization. In the presence of small piston errors, the dominant sources of closure phase error (depending on pixel sampling, and filter bandwidth) are flat field errors and unmodeled variations in intra-pixel sensitivity. The in-flight stability of NIRISS will determine how well these errors can be calibrated by observing a point source. Our results help develop efficient observing strategies for space-based NRM.« less

Field Observations of Hydrodynamics, Sediment Transport, and Water and Sediment Quality in the Hudson-Raritan Estuary

NASA Astrophysics Data System (ADS)

Bruno, M. S.; Glenn, S.; Chant, R.; Rankin, K.; Korfiatis, G.; Dimou, N.; Creed, E.; Fullerton, B.; Pence, A.; Burke, P.; Haldeman, C.; Hires, R.; Hunter, E.

2002-12-01

The New York-New Jersey Harbor estuary system is of enormous ecological and economic importance to the region. The presence of toxic chemicals in the water and sediments results in reduced water quality, fisheries restrictions/advisories, and general adverse impacts to the estuarine ecosystem. The Port of New York and New Jersey is central to the economy of the region. However, in recent years, problems associated with the management of contaminated dredged material, including high costs and the lack of suitable disposal/use alternatives, have threatened to impact the volume of shipping in the Harbor. Sources of contaminants include atmospheric deposition, municipal and industrial wastewater treatment facilities, combined sewer and stormwater outfalls, and rainfall-induced runoff (non-point sources). In addition, Harbor sediments can act as a continuing source as they are re-suspended and moved throughout the system by both natural and man-made means. As part of the New Jersey Toxics Reduction Workplan, Stevens Institute of Technology and Rutgers University are conducting hydrodynamic, sediment transport, and water and suspended sediment quality measurements in Newark Bay, the Arthur Kill and the Kill van Kull. The goals of the project include: (1) collection of high resolution (event-driven and long-term) hydrodynamic, sediment transport and water and suspended sediment quality measurements for use in the assessment of the dominant physics of the system and in the development of a combined hydrodynamic-sediment transport-water/sediment quality model for the region. (2) identification of those tributaries to NY-NJ Harbor that are significant sources of the chemicals of concern, and evaluation of the importance of non-point sources and existing contaminated bottom sediments as sources of the chemicals of concern. (3) identification of point discharges that represent significant sources of the chemicals of concern. Observations were obtained over a two-year period, during 21 tributary flow "events", each having an approximate duration of 1 week. The measurement program included 3 fixed mooring stations and 5 shipboard locations. Each mooring consisted of an acoustic Doppler current profiler; a high-resolution pressure sensor; an OBS; a CTD; and a laser-based scatterometer. The ship-board measurements included vertical current profiles using a towed acoustic Doppler current profiler; CTD measurements; OBS measurements; suspended sediment concentration and particle size spectrum using a laser-based scatterometer; and chemical characterization of water and suspended sediment samples. The water and sediment quality measurements were obtained using a specially designed Trace Organics Platform Sampler. This sampler allowed for the measurement of low-level concentrations of PCBs (108 congeners), dioxins/furans, Pesticides, PAHs and metals (Hg, Cd, Pb). Preliminary analysis of the data has improved our understanding of the circulation and sediment transport patterns in this region of the estuary, including the influence of extreme tributary flow events, local winds, and anthropogenic effects such as port structures, vessels, and the navigation channels, and has identified the most highly contaminated reaches of the tributaries.

Sambucus nigra extracts inhibit infectious bronchitis virus at an early point during replication

PubMed Central

2014-01-01

Background Infectious bronchitis virus (IBV) is a pathogenic chicken coronavirus. Currently, vaccination against IBV is only partially protective; therefore, better preventions and treatments are needed. Plants produce antimicrobial secondary compounds, which may be a source for novel anti-viral drugs. Non-cytotoxic, crude ethanol extracts of Rhodiola rosea roots, Nigella sativa seeds, and Sambucus nigra fruit were tested for anti-IBV activity, since these safe, widely used plant tissues contain polyphenol derivatives that inhibit other viruses. Results Dose–response cytotoxicity curves on Vero cells using trypan blue staining determined the highest non-cytotoxic concentrations of each plant extract. To screen for IBV inhibition, cells and virus were pretreated with extracts, followed by infection in the presence of extract. Viral cytopathic effect was assessed visually following an additional 24 h incubation with extract. Cells and supernatants were harvested separately and virus titers were quantified by plaque assay. Variations of this screening protocol determined the effects of a number of shortened S. nigra extract treatments. Finally, S. nigra extract-treated virions were visualized by transmission electron microscopy with negative staining. Virus titers from infected cells treated with R. rosea and N. sativa extracts were not substantially different from infected cells treated with solvent alone. However, treatment with S. nigra extracts reduced virus titers by four orders of magnitude at a multiplicity of infection (MOI) of 1 in a dose-responsive manner. Infection at a low MOI reduced viral titers by six orders of magnitude and pretreatment of virus was necessary, but not sufficient, for full virus inhibition. Electron microscopy of virions treated with S. nigra extract showed compromised envelopes and the presence of membrane vesicles, which suggested a mechanism of action. Conclusions These results demonstrate that S. nigra extract can inhibit IBV at an early point in infection, probably by rendering the virus non-infectious. They also suggest that future studies using S. nigra extract to treat or prevent IBV or other coronaviruses are warranted. PMID:24433341

Association of land use and beach closure in the United ...

EPA Pesticide Factsheets

Swimming in natural waters (e.g., oceans, lakes, rivers) is one of most popular recreational activities in the United States. However, exposure to pathogens (e.g., Salmonella spp., Shigella spp., Cryptosporidium, Giardia, adenovirus, norovirus) in recreational waters can lead to a variety of adverse health outcomes. To protect public health and reduce the number of outbreaks associated with recreational waters, the BEACH Act was passed in 2000, which required beach regulators to develop a formal plan to assess beach water quality and to notify the public if recreational waters are unsafe. High levels of microorganisms in water often follow extreme weather events. Besides extreme weather events, the proximity of certain land uses to beaches may also have great influence on beach water quality. Microbial contaminants that lead to beach closures and human illness come mainly from land, either from discrete point sources or from diffuse non-point sources. It is expected that land use will have considerable influence on beach microbial water quality. However, to date, studies on impacts of land use on beach microbial contamination are rare, and few researchers are aware of the relationship between land use and beach closures.In this study, we analyzed beach closure data obtained from 2004 to 2013 for more than 500 beaches in the United States, and examined their associations with land use around beaches in 2006 and 2011. The results show that the number of beach clos

Tuning Vortex Creep in Irradiated YBa2Cu3O7-δ Coated Conductors

NASA Astrophysics Data System (ADS)

Eley, Serena; Kihlstrom, Karen; Holleis, Sigrid; Leroux, Maxime; Rupich, Martin; Miller, Dean; Kayani, Asghar; Welp, Ulrich; Kwok, Wai-Kwong; Civale, Leonardo

YBa2Cu3O7-δ coated conductors (CCs) show non-monotonic changes in the temperature-dependent creep rate, S (T) , due to mixed pinning landscapes comprised of twin boundaries, planar defects, point defects, and nanoparticle precipitates. Notably, in low fields, there is a conspicuous dip in S as T increases from ~20K to ~65K. The source of this dip is poorly understood. Moreover, pinning landscapes that are favorable for high critical currents, Jc, are not necessarily optimal for low S. We have found that, though oxygen irradiation introduces few-nm-sized defects that result in significant increases in Jc, it is detrimental to creep, increasing S (reducing the dip depth) for T > 20K. Understanding the source of this dip is crucial to engineering pinning landscapes that concurrently promote high Jc and low S. To this end, we study changes in S (T) as we tune the ratio of smaller (point to few-nm-sized) defects to larger nanoparticles in an oxygen-irradiated CC by annealing in O2 at 250°C to 600°C. We observe a steady decrease in S (T > 20K) with increasing annealing temperature. This suggests that pre-existing nanoparticle precipitates are likely responsible for the dip in S (T) , and underlines the fact that the effects of defects are not additive, but rather can be competitive.

High-Precision Registration of Point Clouds Based on Sphere Feature Constraints.

PubMed

Huang, Junhui; Wang, Zhao; Gao, Jianmin; Huang, Youping; Towers, David Peter

2016-12-30

Point cloud registration is a key process in multi-view 3D measurements. Its precision affects the measurement precision directly. However, in the case of the point clouds with non-overlapping areas or curvature invariant surface, it is difficult to achieve a high precision. A high precision registration method based on sphere feature constraint is presented to overcome the difficulty in the paper. Some known sphere features with constraints are used to construct virtual overlapping areas. The virtual overlapping areas provide more accurate corresponding point pairs and reduce the influence of noise. Then the transformation parameters between the registered point clouds are solved by an optimization method with weight function. In that case, the impact of large noise in point clouds can be reduced and a high precision registration is achieved. Simulation and experiments validate the proposed method.

High-Precision Registration of Point Clouds Based on Sphere Feature Constraints

PubMed Central

Huang, Junhui; Wang, Zhao; Gao, Jianmin; Huang, Youping; Towers, David Peter

2016-01-01

Point cloud registration is a key process in multi-view 3D measurements. Its precision affects the measurement precision directly. However, in the case of the point clouds with non-overlapping areas or curvature invariant surface, it is difficult to achieve a high precision. A high precision registration method based on sphere feature constraint is presented to overcome the difficulty in the paper. Some known sphere features with constraints are used to construct virtual overlapping areas. The virtual overlapping areas provide more accurate corresponding point pairs and reduce the influence of noise. Then the transformation parameters between the registered point clouds are solved by an optimization method with weight function. In that case, the impact of large noise in point clouds can be reduced and a high precision registration is achieved. Simulation and experiments validate the proposed method. PMID:28042846

The distribution of infrared point sources in nearby elliptical galaxies

NASA Astrophysics Data System (ADS)

Gogoi, Rupjyoti; Shalima, P.; Misra, Ranjeev

2018-02-01

Infrared (IR) point sources as observed by Spitzer, in nearby early-type galaxies should either be bright sources in the galaxy such as globular clusters, or they may be background sources such as AGNs. These objects are often counterparts of sources in other wavebands such as optical and X-rays and the IR information provides crucial information regarding their nature. However, many of the IR sources may be background objects and it is important to identify them or at least quantify the level of background contamination. Moreover, the distribution of these IR point sources in flux, distance from the centre and colour would be useful in understanding their origin. Archival Spitzer IRAC images provide a unique opportunity for such a study and here we present the results of such an analysis for four nearby galaxies, NGC 1399, NGC 2768, NGC 4365 and NGC 4649. We estimate the background contamination using several blank fields. Our results suggest that IR colours can be effectively used to differentiate between sources in the galaxy and background ones. In particular we find that sources having AGN like colours are indeed consistent with being background AGNs. For sources with non AGN like colours we compute the distribution of flux and normalised distance from the centre which is found to be of a power-law form. Although our sample size is small, the power-law index for the galaxies are different indicating perhaps that the galaxy environment may be playing a part in their origin and nature.

A non-axial superconducting magnet design for optimized patient access and minimal SAD for use in a Linac-MR hybrid: proof of concept.

PubMed

Yaghoobpour Tari, Shima; Wachowicz, Keith; Gino Fallone, B

2017-04-21

A prototype rotating hybrid magnetic resonance imaging system and linac has been developed to allow for simultaneous imaging and radiation delivery parallel to B 0 . However, the design of a compact magnet capable of rotation in a small vault with sufficient patient access and a typical clinical source-to-axis distance (SAD) is challenging. This work presents a novel superconducting magnet design as a proof of concept that allows for a reduced SAD and ample patient access by moving the superconducting coils to the side of the yoke. The yoke and pole-plate structures are shaped to direct the magnetic flux appropriately. The outer surface of the pole plate is optimized subject to the minimization of a cost function, which evaluates the uniformity of the magnetic field over an ellipsoid. The magnetic field calculations required in this work are performed with the 3D finite element method software package Opera-3D. Each tentative design strategy is virtually modeled in this software package, which is externally controlled by MATLAB, with its key geometries defined as variables. The optimization variables are the thickness of the pole plate at control points distributed over the pole plate surface. A novel design concept as a superconducting non-axial magnet is introduced, which could create a large uniform B 0 magnetic field with fewer geometric restriction. This non-axial 0.5 T superconducting magnet has a moderately reduced SAD of 123 cm and a vertical patient opening of 68 cm. This work is presented as a proof of principle to investigate the feasibility of a non-axial magnet with the coils located around the yoke, and the results encourage future design optimizations to maximize the benefits of this non-axial design.

A non-axial superconducting magnet design for optimized patient access and minimal SAD for use in a Linac-MR hybrid: proof of concept

NASA Astrophysics Data System (ADS)

Yaghoobpour Tari, Shima; Wachowicz, Keith; Fallone, B. Gino

2017-04-01

A prototype rotating hybrid magnetic resonance imaging system and linac has been developed to allow for simultaneous imaging and radiation delivery parallel to B 0. However, the design of a compact magnet capable of rotation in a small vault with sufficient patient access and a typical clinical source-to-axis distance (SAD) is challenging. This work presents a novel superconducting magnet design as a proof of concept that allows for a reduced SAD and ample patient access by moving the superconducting coils to the side of the yoke. The yoke and pole-plate structures are shaped to direct the magnetic flux appropriately. The outer surface of the pole plate is optimized subject to the minimization of a cost function, which evaluates the uniformity of the magnetic field over an ellipsoid. The magnetic field calculations required in this work are performed with the 3D finite element method software package Opera-3D. Each tentative design strategy is virtually modeled in this software package, which is externally controlled by MATLAB, with its key geometries defined as variables. The optimization variables are the thickness of the pole plate at control points distributed over the pole plate surface. A novel design concept as a superconducting non-axial magnet is introduced, which could create a large uniform B 0 magnetic field with fewer geometric restriction. This non-axial 0.5 T superconducting magnet has a moderately reduced SAD of 123 cm and a vertical patient opening of 68 cm. This work is presented as a proof of principle to investigate the feasibility of a non-axial magnet with the coils located around the yoke, and the results encourage future design optimizations to maximize the benefits of this non-axial design.

Source partitioning of anthropogenic groundwater nitrogen in a mixed-use landscape, Tutuila, American Samoa

NASA Astrophysics Data System (ADS)

Shuler, Christopher K.; El-Kadi, Aly I.; Dulai, Henrietta; Glenn, Craig R.; Fackrell, Joseph

2017-12-01

This study presents a modeling framework for quantifying human impacts and for partitioning the sources of contamination related to water quality in the mixed-use landscape of a small tropical volcanic island. On Tutuila, the main island of American Samoa, production wells in the most populated region (the Tafuna-Leone Plain) produce most of the island's drinking water. However, much of this water has been deemed unsafe to drink since 2009. Tutuila has three predominant anthropogenic non-point-groundwater-pollution sources of concern: on-site disposal systems (OSDS), agricultural chemicals, and pig manure. These sources are broadly distributed throughout the landscape and are located near many drinking-water wells. Water quality analyses show a link between elevated levels of total dissolved groundwater nitrogen (TN) and areas with high non-point-source pollution density, suggesting that TN can be used as a tracer of groundwater contamination from these sources. The modeling framework used in this study integrates land-use information, hydrological data, and water quality analyses with nitrogen loading and transport models. The approach utilizes a numerical groundwater flow model, a nitrogen-loading model, and a multi-species contaminant transport model. Nitrogen from each source is modeled as an independent component in order to trace the impact from individual land-use activities. Model results are calibrated and validated with dissolved groundwater TN concentrations and inorganic δ15N values, respectively. Results indicate that OSDS contribute significantly more TN to Tutuila's aquifers than other sources, and thus should be prioritized in future water-quality management efforts.

Diffractive micro-optical element with nonpoint response

NASA Astrophysics Data System (ADS)

Soifer, Victor A.; Golub, Michael A.

1993-01-01

Common-use diffractive lenses have microrelief zones in the form of simple rings that provide only an optical power but do not contain any image information. They have a point-image response under point-source illumination. We must use a more complicated non-point response to focus a light beam into different light marks, letter-type images as well as for optical pattern recognition. The current presentation describes computer generation of diffractive micro- optical elements with complicated curvilinear zones of a regular piecewise-smooth structure and grey-level or staircase phase microrelief. The manufacture of non-point response elements uses the steps of phase-transfer calculation and orthogonal-scan masks generation or lithographic glass etching. Ray-tracing method is shown to be applicable in this task. Several working samples of focusing optical elements generated by computer and photolithography are presented. Using the experimental results we discuss here such applications as laser branding.

GPU Acceleration of Mean Free Path Based Kernel Density Estimators for Monte Carlo Neutronics Simulations

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

Burke, TImothy P.; Kiedrowski, Brian C.; Martin, William R.

Kernel Density Estimators (KDEs) are a non-parametric density estimation technique that has recently been applied to Monte Carlo radiation transport simulations. Kernel density estimators are an alternative to histogram tallies for obtaining global solutions in Monte Carlo tallies. With KDEs, a single event, either a collision or particle track, can contribute to the score at multiple tally points with the uncertainty at those points being independent of the desired resolution of the solution. Thus, KDEs show potential for obtaining estimates of a global solution with reduced variance when compared to a histogram. Previously, KDEs have been applied to neutronics formore » one-group reactor physics problems and fixed source shielding applications. However, little work was done to obtain reaction rates using KDEs. This paper introduces a new form of the MFP KDE that is capable of handling general geometries. Furthermore, extending the MFP KDE to 2-D problems in continuous energy introduces inaccuracies to the solution. An ad-hoc solution to these inaccuracies is introduced that produces errors smaller than 4% at material interfaces.« less

40 CFR 430.81 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Specialized definitions. 430.81 Section 430.81 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Non-Wood Chemical Pulp...

REMOTE SENSING APPLICATIONS FOR SUSTAINABLE WATERSHED MANAGEMENT AND FOOD SECURITY

EPA Science Inventory

The integration of IKONOS satellite data, airborne color infrared remote sensing, visualization, and decision support tools is discussed, within the contexts of management techniques for minimizing non-point source pollution in inland waterways, such s riparian buffer restoration...

40 CFR 430.121 - Specialized definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Specialized definitions. 430.121 Section 430.121 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non...

40 CFR 430.121 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Specialized definitions. 430.121 Section 430.121 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non-Woven, and...

40 CFR 430.121 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Specialized definitions. 430.121 Section 430.121 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non...

40 CFR 430.121 - Specialized definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Specialized definitions. 430.121 Section 430.121 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non...

40 CFR 430.121 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Specialized definitions. 430.121 Section 430.121 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Tissue, Filter, Non-Woven, and...

40 CFR 408.91 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Specialized definitions. 408.91 Section 408.91 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing...

40 CFR 408.91 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Specialized definitions. 408.91 Section 408.91 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Shrimp Processing...

40 CFR 408.123 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 29 2011-07-01 2009-07-01 true [Reserved] 408.123 Section 408.123 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Southern Non-Breaded Shrimp Processing in...

40 CFR 408.123 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true [Reserved] 408.123 Section 408.123 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Southern Non-Breaded Shrimp Processing in...

USEPA EPIC IMPERVIOUS SURFACE RESEARCH IN THE MID-ATLANTIC

EPA Science Inventory

Anthropogenic impervious surfaces have an important relationship with non-point source pollution (NPS) in urban watersheds. These human-created surfaces include such features as roads, parking lots, rooftops, sidewalks, and driveways. The amount of impervious surface area in a ...

40 CFR 430.81 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Specialized definitions. 430.81 Section 430.81 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Non-Wood Chemical Pulp Subcategory...

40 CFR 430.81 - Specialized definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Specialized definitions. 430.81 Section 430.81 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Non-Wood Chemical Pulp Subcategory...

A COMPUTATIONAL FRAMEWORK FOR EVALUATION OF NPS MANAGEMENT SCENARIOS: ROLE OF PARAMETER UNCERTAINTY

EPA Science Inventory

Utility of complex distributed-parameter watershed models for evaluation of the effectiveness of non-point source sediment and nutrient abatement scenarios such as Best Management Practices (BMPs) often follows the traditional {calibrate ---> validate ---> predict} procedure. Des...

Volatile organic compounds in storm water from a parking lot

USGS Publications Warehouse

Lopes, T.J.; Fallon, J.D.; Rutherford, D.W.; Hiatt, M.H.

2000-01-01

A mass balance approach was used to determine the most important nonpoint source of volatile organic compounds (VOCs) in storm water from an asphalt parking lot without obvious point sources (e.g., gasoline stations). The parking lot surface and atmosphere are important nonpoint sources of VOCs, with each being important for different VOCs. The atmosphere is an important source of soluble, oxygenated VOCs (e.g., acetone), and the parking lot surface is an important source for the more hydrophobic VOCs (e.g., benzene). VOCs on the parking lot surface appear to be concentrated in oil and grease and organic material in urban particles (e.g., vehicle soot). Except in the case of spills, asphalt does not appear to be an important source of VOCs. The uptake isotherm of gaseous methyl tert-butyl ether on urban particles indicates a mechanism for dry deposition of VOCs from the atmosphere. This study demonstrated that a mass balance approach is a useful means of understanding non-point-source pollution, even for compounds such as VOCs, which are difficult to sample.

Identification of antibiotic resistant bacteria community and a GeoChip based study of resistome in urban watersheds.

PubMed

Low, Adrian; Ng, Charmaine; He, Jianzhong

2016-12-01

Urban watersheds from point sources are potential reservoirs of antibiotic resistance genes (ARGs). However, few studies have investigated urban watersheds of non-point sources. To understand the type of ARGs and bacteria that might carry such genes, we investigated two non-point source urban watersheds with different land-use profiles. Antibiotic resistance levels of two watersheds (R1, R3) were examined using heterotrophic plate counts (HPC) as a culturing method to obtain counts of bacteria resistant to seven antibiotics belonging to different classes (erythromycin, kanamycin, lincomycin, norfloxacin, sulfanilamide, tetracycline and trimethoprim). From the HPC study, 239 antibiotic resistant bacteria were characterized for resistance to more antibiotics. Furthermore, ARGs and antimicrobial biosynthesis genes were identified using GeoChip version 5.0 to elucidate the resistomes of surface waters in watersheds R1 and R3. The HPC study showed that water samples from R1 had significantly higher counts of bacteria resistant to erythromycin, kanamycin, norfloxacin, sulfanilamide, tetracycline and trimethoprim than those from R3 (Analysis of Similarity (ANOSIM), R = 0.557, p < 0.01). Of the seven antibiotics tested, lincomycin and trimethoprim resistant bacteria are greater in abundances. The 239 antibiotic resistant isolates represent a subset of resistant bacterial populations, including bacteria not previously known for resistance. Majority of the isolates had resistance to ampicillin, vancomycin, lincomycin and trimethoprim. GeoChip revealed similar ARGs in both watersheds, but with significantly higher intensities for tetX and β-lactamase B genes in R1 than R3. The genes with the highest average normalized intensities in R1 and R3 were tetracycline (tet) and fosfomycin (fosA) resistance genes, respectively. The higher abundance of tetX genes in R1 is congruent with the higher abundance of tetracycline resistant HPC observed in R1 samples. Strong correlations (r ≥ 0.8) of efflux pumps with antimicrobial biosynthesis genes suggest that natural production of antimicrobials may act as a selective pressure of transporter proteins in the absence of antibiotics from anthropogenic sources. In conclusion, distinct antibiotic resistant bacteria phylotypes and a variety of ARGs were present in the non-point sources urban watersheds of different land-use profiles, suggesting that ARG risk assessments and monitoring studies need to include these types of watersheds. Copyright © 2016 Elsevier Ltd. All rights reserved.

Redox active molecules cytochrome c and vitamin C enhance heme-enzyme peroxidations by serving as non-specific agents for redox relay

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

Gade, Sudeep Kumar; Bhattacharya, Subarna; Manoj, Kelath Murali, E-mail: satyamjayatu@yahoo.com

2012-03-09

Highlights: Black-Right-Pointing-Pointer At low concentrations, cytochrome c/vitamin C do not catalyze peroxidations. Black-Right-Pointing-Pointer But low levels of cytochrome c/vitamin C enhance diverse heme peroxidase activities. Black-Right-Pointing-Pointer Enhancement positively correlates to the concentration of peroxide in reaction. Black-Right-Pointing-Pointer Reducible additives serve as non-specific agents for redox relay in the system. Black-Right-Pointing-Pointer Insight into electron transfer processes in routine and oxidative-stress states. -- Abstract: We report that incorporation of very low concentrations of redox protein cytochrome c and redox active small molecule vitamin C impacted the outcome of one-electron oxidations mediated by structurally distinct plant/fungal heme peroxidases. Evidence suggests that cytochrome cmore » and vitamin C function as a redox relay for diffusible reduced oxygen species in the reaction system, without invoking specific or affinity-based molecular interactions for electron transfers. The findings provide novel perspectives to understanding - (1) the promiscuous role of cytochrome b{sub 5} in the metabolism mediated by liver microsomal xenobiotic metabolizing systems and (2) the roles of antioxidant molecules in affording relief from oxidative stress.« less

Distributed and dynamic modelling of hydrology, phosphorus and ecology in the Hampshire Avon and Blashford Lakes: evaluating alternative strategies to meet WFD standards.

PubMed

Whitehead, P G; Jin, L; Crossman, J; Comber, S; Johnes, P J; Daldorph, P; Flynn, N; Collins, A L; Butterfield, D; Mistry, R; Bardon, R; Pope, L; Willows, R

2014-05-15

The issues of diffuse and point source phosphorus (P) pollution in the Hampshire Avon and Blashford Lakes are explored using a catchment model of the river system. A multibranch, process based, dynamic water quality model (INCA-P) has been applied to the whole river system to simulate water fluxes, total phosphorus (TP) and soluble reactive phosphorus (SRP) concentrations and ecology. The model has been used to assess impacts of both agricultural runoff and point sources from waste water treatment plants (WWTPs) on water quality. The results show that agriculture contributes approximately 40% of the phosphorus load and point sources the other 60% of the load in this catchment. A set of scenarios have been investigated to assess the impacts of alternative phosphorus reduction strategies and it is shown that a combined strategy of agricultural phosphorus reduction through either fertiliser reductions or better phosphorus management together with improved treatment at WWTPs would reduce the SRP concentrations in the river to acceptable levels to meet the EU Water Framework Directive (WFD) requirements. A seasonal strategy for WWTP phosphorus reductions would achieve significant benefits at reduced cost. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Kobulnicky, Henry A.; Alexander, Michael J.; Babler, Brian L.

We characterize the completeness of point source lists from Spitzer Space Telescope surveys in the four Infrared Array Camera (IRAC) bandpasses, emphasizing the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) programs (GLIMPSE I, II, 3D, 360; Deep GLIMPSE) and their resulting point source Catalogs and Archives. The analysis separately addresses effects of incompleteness resulting from high diffuse background emission and incompleteness resulting from point source confusion (i.e., crowding). An artificial star addition and extraction analysis demonstrates that completeness is strongly dependent on local background brightness and structure, with high-surface-brightness regions suffering up to five magnitudes of reduced sensitivity to pointmore » sources. This effect is most pronounced at the IRAC 5.8 and 8.0 {mu}m bands where UV-excited polycyclic aromatic hydrocarbon emission produces bright, complex structures (photodissociation regions). With regard to diffuse background effects, we provide the completeness as a function of stellar magnitude and diffuse background level in graphical and tabular formats. These data are suitable for estimating completeness in the low-source-density limit in any of the four IRAC bands in GLIMPSE Catalogs and Archives and some other Spitzer IRAC programs that employ similar observational strategies and are processed by the GLIMPSE pipeline. By performing the same analysis on smoothed images we show that the point source incompleteness is primarily a consequence of structure in the diffuse background emission rather than photon noise. With regard to source confusion in the high-source-density regions of the Galactic Plane, we provide figures illustrating the 90% completeness levels as a function of point source density at each band. We caution that completeness of the GLIMPSE 360/Deep GLIMPSE Catalogs is suppressed relative to the corresponding Archives as a consequence of rejecting stars that lie in the point-spread function wings of saturated sources. This effect is minor in regions of low saturated star density, such as toward the Outer Galaxy; this effect is significant along sightlines having a high density of saturated sources, especially for Deep GLIMPSE and other programs observing closer to the Galactic center using 12 s or longer exposure times.« less

Reduced nutrient pollution in a rural stream following septic tank upgrade and installation of runoff retention measures.

PubMed

Ockenden, M C; Quinton, J N; Favaretto, N; Deasy, C; Surridge, B

2014-07-01

Surface water quality in the UK and much of Western Europe has improved in recent decades, in response to better point source controls and the regulation of fertilizer, manure and slurry use. However, diffuse sources of pollution, such as leaching or runoff of nutrients from agricultural fields, and micro-point sources including farmyards, manure heaps and septic tank sewerage systems, particularly systems without soil adsorption beds, are now hypothesised to contribute a significant proportion of the nutrients delivered to surface watercourses. Tackling such sources in an integrated manner is vital, if improvements in freshwater quality are to continue. In this research, we consider the combined effect of constructing small field wetlands and improving a septic tank system on stream water quality within an agricultural catchment in Cumbria, UK. Water quality in the ditch-wetland system was monitored by manual sampling at fortnightly intervals (April-October 2011 and February-October 2012), with the septic tank improvement taking place in February 2012. Reductions in nutrient concentrations were observed through the catchment, by up to 60% when considering total phosphorus (TP) entering and leaving a wetland with a long residence time. Average fluxes of TP, soluble reactive phosphorus (SRP) and ammonium-N (NH4-N) at the head of the ditch system in 2011 (before septic tank improvement) compared to 2012 (after septic tank improvement) were reduced by 28%, 9% and 37% respectively. However, TP concentration data continue to show a clear dilution with increasing flow, indicating that the system remained point source dominated even after the septic tank improvement.

Separating non-diffuse component from ambient seismic noise cross-correlation in southern California­­

NASA Astrophysics Data System (ADS)

Liu, X.; Beroza, G. C.; Nakata, N.

2017-12-01

Cross-correlation of fully diffuse wavefields provides Green's function between receivers, although the ambient noise field in the real world contains both diffuse and non-diffuse fields. The non-diffuse field potentially degrades the correlation functions. We attempt to blindly separate the diffuse and the non-diffuse components from cross-correlations of ambient seismic noise and analyze the potential bias caused by the non-diffuse components. We compute the 9-component noise cross-correlations for 17 stations in southern California. For the Rayleigh wave components, we assume that the cross-correlation of multiply scattered waves (diffuse component) is independent from the cross-correlation of ocean microseismic quasi-point source responses (non-diffuse component), and the cross-correlation function of ambient seismic data is the sum of both components. Thus we can blindly separate the non-diffuse component due to physical point sources and the more diffuse component due to cross-correlation of multiply scattered noise based on their statistical independence. We also perform beamforming over different frequency bands for the cross-correlations before and after the separation, and we find that the decomposed Rayleigh wave represents more coherent features among all Rayleigh wave polarization cross-correlation components. We show that after separating the non-diffuse component, the Frequency-Time Analysis results are less ambiguous. In addition, we estimate the bias in phase velocity on the raw cross-correlation data due to the non-diffuse component. We also apply this technique to a few borehole stations in Groningen, the Netherlands, to demonstrate its applicability in different instrument/geology settings.

Procedure for Separating Noise Sources in Measurements of Turbofan Engine Core Noise

NASA Technical Reports Server (NTRS)

Miles, Jeffrey Hilton

2006-01-01

The study of core noise from turbofan engines has become more important as noise from other sources like the fan and jet have been reduced. A multiple microphone and acoustic source modeling method to separate correlated and uncorrelated sources has been developed. The auto and cross spectrum in the frequency range below 1000 Hz is fitted with a noise propagation model based on a source couplet consisting of a single incoherent source with a single coherent source or a source triplet consisting of a single incoherent source with two coherent point sources. Examples are presented using data from a Pratt & Whitney PW4098 turbofan engine. The method works well.

Characterization of mercury contamination in the Androscoggin River, Coos County, New Hampshire

USGS Publications Warehouse

Chalmers, Ann; Marvin-DiPasquale, Mark C.; Degnan, James R.; Coles, James; Agee, Jennifer L.; Luce, Darryl

2013-01-01

Concentrations of total mercury (THg) and MeHg in sediment, pore water, and biota in the Androscoggin River were elevated downstream from the former chloralkali facility compared with those upstream from reference sites. Sequential extraction of surface sediment showed a distinct difference in Hg speciation upstream compared with downstream from the contamination site. An upstream site was dominated by potassium hydroxide-extractable forms (for example, organic-Hg or particle-bound Hg(II)), whereas sites downstream from the point source were dominated by more chemically recalcitrant forms (largely concentrated nitric acid-extractable), indicative of elemental mercury or mercurous chloride. At all sites, only a minor fraction (less than 0.1 percent) of THg existed in chemically labile forms (for example, water extractable or weak acid extractable). All metrics indicated that a greater percentage of mercury at an upstream site was available for Hg(II)-methylation compared with sites downstream from the point source, but the absolute concentration of bioavailable Hg(II) was greater downstream from the point source. In addition, the concentration of tin-reducible inorganic reactive mercury, a surrogate measure of bioavailable Hg(II) generally increased with distance downstream from the point source. Whereas concentrations of mercury species on a sediment-dry-weight basis generally reflected the relative location of the sample to the point source, river-reach integrated mercury-species inventories and MeHg production potential (MPP) rates reflected the amount of fine-grained sediment in a given reach. THg concentrations in biota were significantly higher downstream from the point source compared with upstream reference sites for smallmouth bass, white sucker, crayfish, oligochaetes, bat fur, nestling tree swallow blood and feathers, adult tree swallow blood, and tree swallow eggs. As with tin-reducible inorganic reactive mercury, THg in smallmouth bass also increased with distance downstream from the point source. Toxicity tests and invertebrate community assessments suggested that invertebrates were not impaired at the current (2009 and 2010) levels of mercury contamination downstream from the point source. Concentrations of THg and MeHg in most water and sediment samples from the Androscoggin River were below U.S. Environmental Protection Agency (USEPA), the Canadian Council of Ministers of the Environment, and probable effects level guidelines. Surface-water and sediment samples from the Androscoggin River had similar THg concentrations but lower MeHg concentrations compared with other rivers in the region. Concentrations of THg in fish tissue were all above regional and U.S. Environmental Protection Agency guidelines. Moreover, median THg concentrations in smallmouth bass from the Androscoggin River were significantly higher than those reported in regional surveys of river and streams nationwide and in the Northeastern United States and Canada. The higher concentrations of mercury in smallmouth bass suggest conditions may be more favorable for Hg(II)-methylation and bioaccumulation in the Androscoggin River compared with many other rivers in the United States and Canada.

Three studies using Ceriodaphnia to detect nonpoint sources of metals from mine drainage

USGS Publications Warehouse

Nimmo, Del Wayne R.; Dodson, Max H.; Davies, Patrick H.; Greene, Joseph C.; Kerr, Mark A.

1990-01-01

Since its introduction, Ceriodaphnia dubia, a small planktonic daphnid, has been widely used for biomonitoring point source discharges. This species was also used to determine nonpoint sources of metals and related contaminants in three trout streams in the west where mining activities have been widespread. Along Chalk Creek, Colo., specific tailings (and impacted tributaries) were sources of metals toxic to fish using the water in a hatchery. At stations below extensive mine tailings in the upper Clark Fork River, Mont., drainage was acutely and chronically toxic to daphnids and paralleled reduced or nonexistent populations of trout. In Whitewood Creek, S. Dak., reduced toxicity below a gold mine portended that fish could live in the stream segment previously impaired by the mine. Toxicity downstream revealed a previously unknown nonpoint source of chromium.

NutrientNet: An Internet-Based Approach to Teaching Market-Based Policy for Environmental Management

ERIC Educational Resources Information Center

Nguyen, To N.; Woodward, Richard T.

2009-01-01

NutrientNet is an Internet-based environment in which a class can simulate a market-based approach for improving water quality. In NutrientNet, each student receives a role as either a point source or a nonpoint source polluter, and then the participants are allowed to trade water quality credits to cost-effectively reduce pollution in a…

Localization of non-stationary sources of electromagnetic radiation with the aid of phasometry

NASA Technical Reports Server (NTRS)

Mersov, G. A.

1978-01-01

The possibility of localizing sources of electromagnetic radiation by measurement of the time of passage of the radiation or the measurement of its phase at various points of cosmic space, at which are located satellite observatories is examined. Algorithms are proposed for localization using two, three, and four astronomical observatories. The precision of the localization and several partial results of practical significance are deduced.

Characterization and source apportionment of health risks from ambient PM10 in Hong Kong over 2000-2011

NASA Astrophysics Data System (ADS)

Li, Zhiyuan; Yuan, Zibing; Li, Ying; Lau, Alexis K. H.; Louie, Peter K. K.

2015-12-01

Atmospheric particulate matter (PM) pollution is a major public health concern in Hong Kong. In this study, the spatiotemporal variations of health risks from ambient PM10 from seven air quality monitoring stations between 2000 and 2011 were analyzed. Positive matrix factorization (PMF) was adopted to identify major source categories of ambient PM10 and quantify their contributions. Afterwards, a point-estimated risk model was used to identify the inhalation cancer and non-cancer risks of PM10 sources. The long-term trends of the health risks from classified local and non-local sources were explored. Furthermore, the reason for the increase of health risks during high PM10 days was discussed. Results show that vehicle exhaust source was the dominant inhalation cancer risk (ICR) contributor (72%), whereas trace metals and vehicle exhaust sources contributed approximately 27% and 21% of PM10 inhalation non-cancer risk (INCR), respectively. The identified local sources accounted for approximately 80% of the ICR in Hong Kong, while contribution percentages of the non-local and local sources for INCR are comparable. The clear increase of ICR at high PM days was mainly attributed to the increase of contributions from coal combustion/biomass burning and secondary sulfate, while the increase of INCR at high PM days was attributed to the increase of contributions from the sources coal combustion/biomass burning, secondary nitrate, and trace metals. This study highlights the importance of health risk-based source apportionment in air quality management with protecting human health as the ultimate target.

Near-optimal experimental design for model selection in systems biology.

PubMed

Busetto, Alberto Giovanni; Hauser, Alain; Krummenacher, Gabriel; Sunnåker, Mikael; Dimopoulos, Sotiris; Ong, Cheng Soon; Stelling, Jörg; Buhmann, Joachim M

2013-10-15

Biological systems are understood through iterations of modeling and experimentation. Not all experiments, however, are equally valuable for predictive modeling. This study introduces an efficient method for experimental design aimed at selecting dynamical models from data. Motivated by biological applications, the method enables the design of crucial experiments: it determines a highly informative selection of measurement readouts and time points. We demonstrate formal guarantees of design efficiency on the basis of previous results. By reducing our task to the setting of graphical models, we prove that the method finds a near-optimal design selection with a polynomial number of evaluations. Moreover, the method exhibits the best polynomial-complexity constant approximation factor, unless P = NP. We measure the performance of the method in comparison with established alternatives, such as ensemble non-centrality, on example models of different complexity. Efficient design accelerates the loop between modeling and experimentation: it enables the inference of complex mechanisms, such as those controlling central metabolic operation. Toolbox 'NearOED' available with source code under GPL on the Machine Learning Open Source Software Web site (mloss.org).

Impact of nitrogen reduction measures on nitrogen surplus, income and production of German agriculture.

PubMed

Gömann, H; Kreins, P; Møller, C

2004-01-01

Among the numerous non-point sources of diffuse water pollution with nitrogen, agriculture is counted one of the main sources. The agricultural policies of the Agenda 2000 and a decoupling of direct payments for farmers from their production decisions are exemplarily evaluated as nitrogen reduction measures using the Regional Agricultural and Environmental Information System RAUMIS. The results show that until the target year 2010 the risk of diffuse pollution of water bodies with nitrogen is a regional problem in Germany. These problems are neither mitigated by the policies of Agenda 2000 nor by a decoupling of direct payments from production decisions of farmers. While total nitrogen surplus reduces considerably after a decoupling of direct payments due to decreases of land-use the nitrogen surplus on the remaining cultivated area increases resulting from structural changes. Granting the same amount of direct payments to farmers in both policy alternatives the agricultural sector income would be higher after a decoupling of direct payments opposed to the Agenda 2000 resulting from a more efficient allocation of inputs.

Seeing the Invisible: Embedding Tests in Code That Cannot be Modified

NASA Technical Reports Server (NTRS)

O'Malley, Owen; Mansouri-Samani, Masoud; Mehlitz, Peter; Penix, John

2005-01-01

The difficulty of characterizing and observing valid software behavior during testing can be very difficult in flight systems. To address this issue, we evaluated several approaches to increasing test observability on the Shuttle Abort Flight Management (SAFM) system. To increase test observability, we added probes into the running system to evaluate the internal state and analyze test data. To minimize the impact of the instrumentation and reduce manual effort, we used Aspect-Oriented Programming (AOP) tools to instrument the source code. We developed and elicited a spectrum of properties, from generic to application specific properties, to be monitored via the instrumentation. To evaluate additional approaches, SAFM was ported to Linux, enabling the use of gcov for measuring test coverage, Valgrind for looking for memory usage errors, and libraries for finding non-normal floating point values. An in-house C++ source code scanning tool was also used to identify violations of SAFM coding standards, and other potentially problematic C++ constructs. Using these approaches with the existing test data sets, we were able to verify several important properties, confirm several problems and identify some previously unidentified issues.

Water quality in organic systems

USDA-ARS?s Scientific Manuscript database

Non-point source contamination is a major water quality concern in the upper Midwestern USA, where plant nutrients, especially NO3-N, are susceptible to leaching due to extensive subsurface draining of the highly productive, but poorly drained, soils found in this region. Environmental impacts assoc...

Simulation of conservation practices using the APEX model

USDA-ARS?s Scientific Manuscript database

Information on agricultural Best Management Practices (BMPs) and their effectiveness in controlling agricultural non-point source pollution is crucial in developing Clean Water Act programs such as the Total Maximum Daily Loads for impaired watersheds. A modeling study was conducted to evaluate var...

STREAM CORRIDOR RESTORATION AND ITS POTENTIAL TO IMPROVE WATER QUALITY

EPA Science Inventory

Watershed stream corridors are being degraded by anthropogenic impacts of increased flow from runoff, sediment loading from erosion and contaminants such as nitrate from non-point sources. One solution is to restore stream corridors with bank stabilization and energy dissipation ...

Multi-scale trends analysis of landscape stressors in an urbanizing coastal watershed

EPA Science Inventory

Anthropogenic land based stressors within a watershed can deliver major impacts to downstream and adjacent coastal waterways affecting water quality and estuarine habitats. Our research focused on a subset of non-point sources of watershed stressors specifically, human population...

Brook Trout Back in Aaron Run

EPA Pesticide Factsheets

Following a series of acid mine drainage (AMD) projects funded largely by EPA’s Clean Water Act Section 319 non-point source program, the pH level in Aaron Run is meeting Maryland’s water quality standard – and the brook trout are back.

Multiobjective Sensitivity Analysis Of Sediment And Nitrogen Processes With A Watershed Model

EPA Science Inventory

This paper presents a computational analysis for evaluating critical non-point-source sediment and nutrient (specifically nitrogen) processes and management actions at the watershed scale. In the analysis, model parameters that bear key uncertainties were presumed to reflect the ...

Watershed Management Tool for Selection and Spacial Allocation of Non-Point Source Pollution Control Practices

EPA Science Inventory

Distributed-parameter watershed models are often utilized for evaluating the effectiveness of sediment and nutrient abatement strategies through the traditional {calibrate→ validate→ predict} approach. The applicability of the method is limited due to modeling approximations. In ...

HESS J1943+213: A candidate extreme BL Lacertae object

DOE PAGES

Abramowski, A.; Acero, F.; Aharonian, F.; ...

2011-03-30

In this paper, we report on a newly detected point-like source, HESS J1943+213. This source coincides with an unidentified hard X-ray source IGR J19443+2117, which was proposed to have radio and infrared counterparts. Here, we combine new H.E.S.S., Fermi/LAT and Nançay Radio Telescope observations with pre-existing non-simultaneous multi-wavelength observations of IGR J19443+2117 and discuss the likely source associations as well as the interpretation as an active galactic nucleus, a gamma-ray binary or a pulsar wind nebula.

Surviving Tight Times.

ERIC Educational Resources Information Center

Neugebauer, Roger

2002-01-01

Discusses several strategies recommended by small business experts to help for-profit and non-profit child care centers survive a financial crisis. Strategies include: identifying the source of the problem, monitoring cash flow, reducing or deferring expenditures, expediting regular income and exploring new sources of income, patiently working…

Is the gamma-ray source 3FGL J2212.5+0703 a dark matter subhalo?

NASA Astrophysics Data System (ADS)

Bertoni, Bridget; Hooper, Dan; Linden, Tim

2016-05-01

In a previous paper, we pointed out that the gamma-ray source 3FGL J2212.5+\\linebreak 0703 shows evidence of being spatially extended. If a gamma-ray source without detectable emission at other wavelengths were unambiguously determined to be spatially extended, it could not be explained by known astrophysics, and would constitute a smoking gun for dark matter particles annihilating in a nearby subhalo. With this prospect in mind, we scrutinize the gamma-ray emission from this source, finding that it prefers a spatially extended profile over that of a single point-like source with 5.1σ statistical significance. We also use a large sample of active galactic nuclei and other known gamma-rays sources as a control group, confirming, as expected, that statistically significant extension is rare among such objects. We argue that the most likely (non-dark matter) explanation for this apparent extension is a pair of bright gamma-ray sources that serendipitously lie very close to each other, and estimate that there is a chance probability of ~2% that such a pair would exist somewhere on the sky. In the case of 3FGL J2212.5+0703, we test an alternative model that includes a second gamma-ray point source at the position of the radio source BZQ J2212+0646, and find that the addition of this source alongside a point source at the position of 3FGL J2212.5+0703 yields a fit of comparable quality to that obtained for a single extended source. If 3FGL J2212.5+0703 is a dark matter subhalo, it would imply that dark matter particles have a mass of ~18-33 GeV and an annihilation cross section on the order of σ v ~ 10-26 cm3/s (for the representative case of annihilations to bbar b), similar to the values required to generate the Galactic Center gamma-ray excess.

Is the gamma-ray source 3FGL J2212.5+0703 a dark matter subhalo?

DOE PAGES

Bertoni, Bridget; Hooper, Dan; Linden, Tim

2016-05-23

In a previous study, we pointed out that the gamma-ray source 3FGL J2212.5+0703 shows evidence of being spatially extended. If a gamma-ray source without detectable emission at other wavelengths were unambiguously determined to be spatially extended, it could not be explained by known astrophysics, and would constitute a smoking gun for dark matter particles annihilating in a nearby subhalo. With this prospect in mind, we scrutinize the gamma-ray emission from this source, finding that it prefers a spatially extended profile over that of a single point-like source with 5.1σ statistical significance. We also use a large sample of active galactic nuclei and other known gamma-rays sources as a control group, confirming, as expected, that statistically significant extension is rare among such objects. We argue that the most likely (non-dark matter) explanation for this apparent extension is a pair of bright gamma-ray sources that serendipitously lie very close to each other, and estimate that there is a chance probability of ~2% that such a pair would exist somewhere on the sky. In the case of 3FGL J2212.5+0703, we test an alternative model that includes a second gamma-ray point source at the position of the radio source BZQ J2212+0646, and find that the addition of this source alongside a point source at the position of 3FGL J2212.5+0703 yields a fit of comparable quality to that obtained for a single extended source. If 3FGL J2212.5+0703 is a dark matter subhalo, it would imply that dark matter particles have a mass of ~18–33 GeV and an annihilation cross section on the order of σv ~ 10 –26 cm(3)/s (for the representative case of annihilations tomore » $$b\\bar{b}$$), similar to the values required to generate the Galactic Center gamma-ray excess.« less

Is the gamma-ray source 3FGL J2212.5+0703 a dark matter subhalo?

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

Bertoni, Bridget; Hooper, Dan; Linden, Tim

In a previous study, we pointed out that the gamma-ray source 3FGL J2212.5+0703 shows evidence of being spatially extended. If a gamma-ray source without detectable emission at other wavelengths were unambiguously determined to be spatially extended, it could not be explained by known astrophysics, and would constitute a smoking gun for dark matter particles annihilating in a nearby subhalo. With this prospect in mind, we scrutinize the gamma-ray emission from this source, finding that it prefers a spatially extended profile over that of a single point-like source with 5.1σ statistical significance. We also use a large sample of active galactic nuclei and other known gamma-rays sources as a control group, confirming, as expected, that statistically significant extension is rare among such objects. We argue that the most likely (non-dark matter) explanation for this apparent extension is a pair of bright gamma-ray sources that serendipitously lie very close to each other, and estimate that there is a chance probability of ~2% that such a pair would exist somewhere on the sky. In the case of 3FGL J2212.5+0703, we test an alternative model that includes a second gamma-ray point source at the position of the radio source BZQ J2212+0646, and find that the addition of this source alongside a point source at the position of 3FGL J2212.5+0703 yields a fit of comparable quality to that obtained for a single extended source. If 3FGL J2212.5+0703 is a dark matter subhalo, it would imply that dark matter particles have a mass of ~18–33 GeV and an annihilation cross section on the order of σv ~ 10 –26 cm(3)/s (for the representative case of annihilations tomore » $$b\\bar{b}$$), similar to the values required to generate the Galactic Center gamma-ray excess.« less

Various DC-driven point-to-plain discharges as non-thermal plasma sources and their bactericidal effects

NASA Astrophysics Data System (ADS)

Khun, Josef; Scholtz, Vladimír; Hozák, Pavel; Fitl, Přemysl; Julák, Jaroslav

2018-06-01

The appearance of several types of ballast serial impedance-stabilized DC-driven electric corona discharges in the point-to-plane configuration is described. In addition to well-known corona discharges, new ones were observed, namely curved transient spark, interrupted channel and branched transient spark. Their properties are described by volt-ampere characteristics and UV-vis emission spectra. Their bactericidal ability for two bacterial species is also given.

How to Avoid Fragility of Financial Systems: Lessons from the Financial Crisis and St. Petersburg Paradox

NASA Astrophysics Data System (ADS)

Takayasu, Hideki

Firstly, I point out that the financial crisis occurred in 2008 has many analogous points with a physical phenomenon of brittle fracture in the sense that it is a highly irreversible phenomenon caused by concentration of stress to the weakest point. Then, I discuss distribution of gain-loss of continuous transactions of options which can be regarded as a source of stress among financial companies. The historical problem of Saint Petersburg paradox is reviewed and it is argued that the paradox is solved by decomposing the process into a combination of a fair gamble and an accompanied financial option. By generalizing this fair gamble it is shown that the gain-loss distribution in this problem is closely related to the distribution of gain-loss of business firms in the real world. Finally, I pose a serious question to the ordinary way of financing money to business firms with compound interest rates. Instead we introduce a new way of financing business firms without applying prefixed interest rates, in which financial stress is shared by all involved firms. This method is expected to reduce the risk of both financial firms and business firms, and is applicable even in the non-growing society.

Suppression of Low Strain Rate Nonpremixed Flames by an Agent

NASA Technical Reports Server (NTRS)

Olson, Sandra L. (Technical Monitor); Hamins, A.; Bundy, M.; Oh, C. B.; Park, J.; Puri, I. K.

2004-01-01

The extinction and structure of non-premixed methane/air flames were investigated in normal gravity and microgravity through the comparison of experiments and calculations using a counterflow configuration. From a fire safety perspective, low strain rate conditions are important for several reasons. In normal gravity, many fires start from small ignition sources where the convective flow and strain rates are weak. Fires in microgravity conditions, such as a manned spacecraft, may also occur in near quiescent conditions where strain rates are very low. When designing a fire suppression system, worst-case conditions should be considered. Most diffusion flames become more robust as the strain rate is decreased. The goal of this project is to investigate the extinction limits of non-premixed flames using various agents and to compare reduced gravity and normal gravity conditions. Experiments at the NASA Glenn Research Center's 2.2-second drop tower were conducted to attain extinction and temperature measurements in low-strain non-premixed flames. Extinction measurements using nitrogen added to the fuel stream were performed for global strain rates from 7/s to 50/s. The results confirmed the "turning point" behavior observed previously by Maruta et al. in a 10 s drop tower. The maximum nitrogen volume fraction in the fuel stream needed to assure extinction for all strain rates was measured to be 0.855+/-0.016, associated with the turning point determined to occur at a strain rate of 15/s. The critical nitrogen volume fraction in the fuel stream needed for extinction of 0-g flames was measured to be higher than that of 1-g flames.

A Parametric Study of Fine-scale Turbulence Mixing Noise

NASA Technical Reports Server (NTRS)

Khavaran, Abbas; Bridges, James; Freund, Jonathan B.

2002-01-01

The present paper is a study of aerodynamic noise spectra from model functions that describe the source. The study is motivated by the need to improve the spectral shape of the MGBK jet noise prediction methodology at high frequency. The predicted spectral shape usually appears less broadband than measurements and faster decaying at high frequency. Theoretical representation of the source is based on Lilley's equation. Numerical simulations of high-speed subsonic jets as well as some recent turbulence measurements reveal a number of interesting statistical properties of turbulence correlation functions that may have a bearing on radiated noise. These studies indicate that an exponential spatial function may be a more appropriate representation of a two-point correlation compared to its Gaussian counterpart. The effect of source non-compactness on spectral shape is discussed. It is shown that source non-compactness could well be the differentiating factor between the Gaussian and exponential model functions. In particular, the fall-off of the noise spectra at high frequency is studied and it is shown that a non-compact source with an exponential model function results in a broader spectrum and better agreement with data. An alternate source model that represents the source as a covariance of the convective derivative of fine-scale turbulence kinetic energy is also examined.

Non-perturbative measurement of cross-field thermal diffusivity reduction at the O-point of 2/1 neoclassical tearing mode islands in the DIII-D tokamak

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

Bardóczi, L.; Rhodes, T. L.; Carter, T. A.

2016-05-15

Neoclassical tearing modes (NTMs) often lead to the decrease of plasma performance and can lead to disruptions, which makes them a major impediment in the development of operating scenarios in present toroidal fusion devices. Recent gyrokinetic simulations predict a decrease of plasma turbulence and cross-field transport at the O-point of the islands, which in turn affects the NTM dynamics. In this paper, a heat transport model of magnetic islands employing spatially non-uniform cross-field thermal diffusivity (χ{sub ⊥}) is presented. This model is used to derive χ{sub ⊥} at the O-point from electron temperature data measured across 2/1 NTM islands inmore » DIII-D. It was found that χ{sub ⊥} at the O-point is 1 to 2 orders of magnitude smaller than the background plasma transport, in qualitative agreement with gyrokinetic predictions. As the anomalously large values of χ{sub ⊥} are often attributed to turbulence driven transport, the reduction of the O-point χ{sub ⊥} is consistent with turbulence reduction found in recent experiments. Finally, the implication of reduced χ{sub ⊥} at the O-point on NTM dynamics was investigated using the modified Rutherford equation that predicts a significant effect of reduced χ{sub ⊥} at the O-point on NTM saturation.« less

Non-perturbative measurement of cross-field thermal diffusivity reduction at the O-point of 2/1 neoclassical tearing mode islands in the DIII-D tokamak

DOE PAGES

Bardóczi, Laszlo; Rhodes, Terry L.; Carter, Troy A.; ...

2016-05-09

Neoclassical Tearing Modes (NTMs) often lead to the decrease of plasma performance and can lead to disruptions, which makes them a major impediment in the development of operating scenarios in present toroidal fusion devices. Recent gyrokinetic simulations predict a decrease of plasma turbulence and cross- eld transport at the O-point of the islands, which in turn affects the NTM dynamics. In this paper a heat transport model of magnetic islands employing spatially non-uniform cross-field thermal diffusivity (χ more » $$\\perp$$) is presented. This model is used to derive χ $$\\perp$$ at the O-point from electron temperature data measured across 2/1 NTM islands in DIII-D. It was found that χ $$\\perp$$ at the O-point is 1 to 2 orders of magnitude smaller than the background plasma transport, in qualitative agreement with gyrokinetic predictions. As the anomalously large values of χ $$\\perp$$ are often attributed to turbulence driven transport, the reduction of the O-point χ $$\\perp$$ is consistent with turbulence reduction found in recent experiments. Lastly, the implication of reduced χ $$\\perp$$ at the O-point on NTM dynamics was investigated using the modi ed Rutherford equation that predicts a significant effect of reduced χ $$\\perp$$ at the O-point on NTM saturation.« less

Sum of the Parts.

ERIC Educational Resources Information Center

Science Activities, 1995

1995-01-01

Presents a Project WET water education activity. Students demonstrate how everyone contributes to the pollution of a river as it flows through a watershed and recognize that everyone's "contribution" can be reduced. Student distinguish between point- and nonpoint-source pollution. (LZ)

Evaluating acoustic speaker normalization algorithms: evidence from longitudinal child data.

PubMed

Kohn, Mary Elizabeth; Farrington, Charlie

2012-03-01

Speaker vowel formant normalization, a technique that controls for variation introduced by physical differences between speakers, is necessary in variationist studies to compare speakers of different ages, genders, and physiological makeup in order to understand non-physiological variation patterns within populations. Many algorithms have been established to reduce variation introduced into vocalic data from physiological sources. The lack of real-time studies tracking the effectiveness of these normalization algorithms from childhood through adolescence inhibits exploration of child participation in vowel shifts. This analysis compares normalization techniques applied to data collected from ten African American children across five time points. Linear regressions compare the reduction in variation attributable to age and gender for each speaker for the vowels BEET, BAT, BOT, BUT, and BOAR. A normalization technique is successful if it maintains variation attributable to a reference sociolinguistic variable, while reducing variation attributable to age. Results indicate that normalization techniques which rely on both a measure of central tendency and range of the vowel space perform best at reducing variation attributable to age, although some variation attributable to age persists after normalization for some sections of the vowel space. © 2012 Acoustical Society of America

Non-line-of-sight ultraviolet link loss in noncoplanar geometry.

PubMed

Wang, Leijie; Xu, Zhengyuan; Sadler, Brian M

2010-04-15

Various path loss models have been developed for solar blind non-line-of-sight UV communication links under an assumption of coplanar source beam axis and receiver pointing direction. This work further extends an existing single-scattering coplanar analytical model to noncoplanar geometry. The model is derived as a function of geometric parameters and atmospheric characteristics. Its behavior is numerically studied in different noncoplanar geometric settings.

Column Number Density Expressions Through M = 0 and M = 1 Point Source Plumes Along Any Straight Path

NASA Technical Reports Server (NTRS)

Woronowicz, Michael S.

2016-01-01

Analytical expressions for column number density (CND) are developed for optical line of sight paths through a variety of steady free molecule point source models including directionally-constrained effusion (Mach number M = 0) and flow from a sonic orifice (M 1). Sonic orifice solutions are approximate, developed using a fair simulacrum fitted to the free molecule solution. Expressions are also developed for a spherically-symmetric thermal expansion (M = 0). CND solutions are found for the most general paths relative to these sources and briefly explored. It is determined that the maximum CND from a distant location through directed effusion and sonic orifice cases occurs along the path parallel to the source plane that intersects the plume axis. For the effusive case this value is exactly twice the CND found along the ray originating from that point of intersection and extending to infinity along the plumes axis. For sonic plumes this ratio is reduced to about 43. For high Mach number cases the maximum CND will be found along the axial centerline path.

Combining stable isotopes with contamination indicators: A method for improved investigation of nitrate sources and dynamics in aquifers with mixed nitrogen inputs.

PubMed

Minet, E P; Goodhue, R; Meier-Augenstein, W; Kalin, R M; Fenton, O; Richards, K G; Coxon, C E

2017-11-01

Excessive nitrate (NO 3 - ) concentration in groundwater raises health and environmental issues that must be addressed by all European Union (EU) member states under the Nitrates Directive and the Water Framework Directive. The identification of NO 3 - sources is critical to efficiently control or reverse NO 3 - contamination that affects many aquifers. In that respect, the use of stable isotope ratios 15 N/ 14 N and 18 O/ 16 O in NO 3 - (expressed as δ 15 N-NO 3 - and δ 18 O-NO 3 - , respectively) has long shown its value. However, limitations exist in complex environments where multiple nitrogen (N) sources coexist. This two-year study explores a method for improved NO 3 - source investigation in a shallow unconfined aquifer with mixed N inputs and a long established NO 3 - problem. In this tillage-dominated area of free-draining soil and subsoil, suspected NO 3 - sources were diffuse applications of artificial fertiliser and organic point sources (septic tanks and farmyards). Bearing in mind that artificial diffuse sources were ubiquitous, groundwater samples were first classified according to a combination of two indicators relevant of point source contamination: presence/absence of organic point sources (i.e. septic tank and/or farmyard) near sampling wells and exceedance/non-exceedance of a contamination threshold value for sodium (Na + ) in groundwater. This classification identified three contamination groups: agricultural diffuse source but no point source (D+P-), agricultural diffuse and point source (D+P+) and agricultural diffuse but point source occurrence ambiguous (D+P±). Thereafter δ 15 N-NO 3 - and δ 18 O-NO 3 - data were superimposed on the classification. As δ 15 N-NO 3 - was plotted against δ 18 O-NO 3 - , comparisons were made between the different contamination groups. Overall, both δ variables were significantly and positively correlated (p < 0.0001, r s  = 0.599, slope of 0.5), which was indicative of denitrification. An inspection of the contamination groups revealed that denitrification did not occur in the absence of point source contamination (group D+P-). In fact, strong significant denitrification lines occurred only in the D+P+ and D+P± groups (p < 0.0001, r s  > 0.6, 0.53 ≤ slope ≤ 0.76), i.e. where point source contamination was characterised or suspected. These lines originated from the 2-6‰ range for δ 15 N-NO 3 - , which suggests that i) NO 3 - contamination was dominated by an agricultural diffuse N source (most likely the large organic matter pool that has incorporated 15 N-depleted nitrogen from artificial fertiliser in agricultural soils and whose nitrification is stimulated by ploughing and fertilisation) rather than point sources and ii) denitrification was possibly favoured by high dissolved organic content (DOC) from point sources. Combining contamination indicators and a large stable isotope dataset collected over a large study area could therefore improve our understanding of the NO 3 - contamination processes in groundwater for better land use management. We hypothesise that in future research, additional contamination indicators (e.g. pharmaceutical molecules) could also be combined to disentangle NO 3 - contamination from animal and human wastes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neutrino Astronomy at the South Pole: latest Results from AMANDA-II

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

Desiati, Paolo

2006-07-11

AMANDA-II is the largest neutrino telescope collecting data at the moment, and its main goal is to search for sources of high energy extra-terrestrial neutrinos. The detection of such sources could give non-controversial evidence for the acceleration of charged hadrons in cosmic objects like Supernova Remnants, Micro-quasars, Active Galactic Nuclei or Gamma Ray Bursts. No significant excess has been found in searching for neutrinos from both point-like and non-localized sources. However AMANDA-II has significantly improved analysis techniques for better signal-to-noise optimization. The km3-scale IceCube telescope will enlarge the observable energy range and improve the sensitivities of high energy neutrino searchesmore » due to its 30 times larger effective area.« less

Technical evaluation of the susceptibility of safety-related systems to flooding caused by the failure of non-Category I systems for Turkey Point Nuclear Power Plant, Units 3 and 4

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

Collins, E.K.

1979-08-01

Three separate reviews of the Turkey Point Units 3 and 4 were conducted by the FPLCO between 1972 and 1975. Initially, at the request of NBC in 1972, the FPLCO reviewed several water systems as sources of flooding. Subsequently, as a result of an abnormal occurrence, the drainage system was reviewed. Finally, the facilities were again reviewed at NRC's request and both the potential sources of flooding and safety-related equipment which could be damaged by flooding were identified. The sources of flooding and the appropriate safety equipment are discussed. An evaluation is presented of measures that were taken by FPLCOmore » to minimize the danger of flooding and to protect safety-related equipment.« less

Non-CO2 greenhouse gases and climate change.

PubMed

Montzka, S A; Dlugokencky, E J; Butler, J H

2011-08-03

Earth's climate is warming as a result of anthropogenic emissions of greenhouse gases, particularly carbon dioxide (CO(2)) from fossil fuel combustion. Anthropogenic emissions of non-CO(2) greenhouse gases, such as methane, nitrous oxide and ozone-depleting substances (largely from sources other than fossil fuels), also contribute significantly to warming. Some non-CO(2) greenhouse gases have much shorter lifetimes than CO(2), so reducing their emissions offers an additional opportunity to lessen future climate change. Although it is clear that sustainably reducing the warming influence of greenhouse gases will be possible only with substantial cuts in emissions of CO(2), reducing non-CO(2) greenhouse gas emissions would be a relatively quick way of contributing to this goal.

COST-EFFECTIVE ALLOCATION OF WATERSHED MANAGEMENT PRACTICES USING A GENETIC ALGORITHM

EPA Science Inventory

Implementation of conservation programs are perceived as being crucial for restoring and protecting waters and watersheds from non-point source pollution. Success of these programs depends to a great extent on planning tools that can assist the watershed management process. Here-...

REMOTE SENSING, VISUALIZATION AND DECISION SUPPORT FOR WATERSHED MANAGEMENT AND SUSTAINABLE AGRICULTURE

EPA Science Inventory

The integration of satellite and airborne remote sensing, scientific visualization and decision support tools is discussed within the context of management techniques for minimizing the non-point source pollution load of inland waterways and the sustainability of food crop produc...

Prepared by: U.S. Environmental Protection Agency Office of Water Regulations and Standards Office of Wetlands Protection June 1990

EPA Pesticide Factsheets

Information and guidance on the coordination of State and Federal Non-Point Source (CWA, Section 319) control and wetland programs (CWA, Section 404)and the implementation of activities that can benefit both programs

DEVELOPING SEASONAL AMMONIA EMISSION ESTIMATES WITH AN INVERSE MODELING TECHNIQUE

EPA Science Inventory

Significant uncertainty exists in magnitude and variability of ammonia (NH3) emissions, which are needed for air quality modeling of aerosols and deposition of nitrogen compounds. Approximately 85% of NH3 emissions are estimated to come from agricultural non-point sources. We sus...

A stepwise, multi-objective, multi-variable parameter optimization method for the APEX model

USDA-ARS?s Scientific Manuscript database

Proper parameterization enables hydrological models to make reliable estimates of non-point source pollution for effective control measures. The automatic calibration of hydrologic models requires significant computational power limiting its application. The study objective was to develop and eval...

Monitoring Mars for Electrostatic Disturbances

NASA Technical Reports Server (NTRS)

Compton, D.

2011-01-01

The DSN radio telescope DSS-13 was used to monitor Mars for electrostatic discharges from 17 February to 11 April, 2010, and from 19 April to 4 May, 2011, over a total of 72 sessions. Of these sessions, few showed noteworthy results and no outstanding electrostatic disturbances were observed on Mars from analyzing the kurtosis of radio emission from Mars. Electrostatic discharges on mars were originally detected in June of 2006 by Ruf et al. using DSS-13. he kurtosis (normalized fourth moment of the electrical field strength) is sensitive to non-thermal radiation. Two frequencies bands, either 2.4 and 8.4 GHz or 8.4 and 32 GHz were used. The non-thermal radiation spectrum should have peaks at the lowest three modes of the theoretical Schumann Resonances of Mars. The telescope was pointed away from Mars every 5 minutes for 45 seconds to confirm if Mars was indeed the sources of any events. It was shown that by including a down-link signal in one channel and by observing when the kurtosis changed as the telescope was pointed away from the source that the procedure can monitor Mars without the need of extra equipment monitoring a control source.

Ford Motor Company NDE facility shielding design.

PubMed

Metzger, Robert L; Van Riper, Kenneth A; Jones, Martin H

2005-01-01

Ford Motor Company proposed the construction of a large non-destructive evaluation laboratory for radiography of automotive power train components. The authors were commissioned to design the shielding and to survey the completed facility for compliance with radiation doses for occupationally and non-occupationally exposed personnel. The two X-ray sources are Varian Linatron 3000 accelerators operating at 9-11 MV. One performs computed tomography of automotive transmissions, while the other does real-time radiography of operating engines and transmissions. The shield thickness for the primary barrier and all secondary barriers were determined by point-kernel techniques. Point-kernel techniques did not work well for skyshine calculations and locations where multiple sources (e.g. tube head leakage and various scatter fields) impacted doses. Shielding for these areas was determined using transport calculations. A number of MCNP [Briesmeister, J. F. MCNPCA general Monte Carlo N-particle transport code version 4B. Los Alamos National Laboratory Manual (1997)] calculations focused on skyshine estimates and the office areas. Measurements on the operational facility confirmed the shielding calculations.

Thermal behavior of the Medicina 32-meter radio telescope

NASA Astrophysics Data System (ADS)

Pisanu, Tonino; Buffa, Franco; Morsiani, Marco; Pernechele, Claudio; Poppi, Sergio

2010-07-01

We studied the thermal effects on the 32 m diameter radio-telescope managed by the Institute of Radio Astronomy (IRA), Medicina, Bologna, Italy. The preliminary results show that thermal gradients deteriorate the pointing performance of the antenna. Data has been collected by using: a) two inclinometers mounted near the elevation bearing and on the central part of the alidade structure; b) a non contact laser alignment optical system capable of measuring the secondary mirror position; c) twenty thermal sensors mounted on the alidade trusses. Two series of measurements were made, the first series was performed by placing the antenna in stow position, the second series was performed while tracking a circumpolar astronomical source. When the antenna was in stow position we observed a strong correlation between the inclinometer measurements and the differential temperature. The latter was measured with the sensors located on the South and North sides of the alidade, thus indicating that the inclinometers track well the thermal deformation of the alidade. When the antenna pointed at the source we measured: pointing errors, the inclination of the alidade, the temperature of the alidade components and the subreflector position. The pointing errors measured on-source were 15-20 arcsec greater than those measured with the inclinometer.

Integrated agro-hydrological modelling and economic analysis of BMPs to support decision making and policy design

NASA Astrophysics Data System (ADS)

Maroy, E.; Rousseau, A. N.; Hallema, D. W.

2012-12-01

With recent efforts and increasing control over point source pollution of freshwater, agricultural non-point pollution sources have become responsible for most of sediment and nutrient loads in North American water systems. Environmental and agricultural agencies have recognised the need for reducing eutrophication and have developed various policies to compel or encourage producers to best management practices (BMPs). Addressing diffuse pollution is challenging considering the complex and cumulative nature of transport processes, high variability in space and time, and prohibitive costs of distributed water quality monitoring. Many policy options exist to push producers to adopt environmentally desirable behaviour while keeping their activity viable, and ensure equitable costs to consumers and tax payers. On the one hand, economic instruments (subsidies, taxes, water quality markets) are designed to maximize cost-effectiveness, so that farmers optimize their production for maximum profit while implementing BMPs. On the other hand, emission standards or regulation of inputs are often easier and less costly to implement. To study economic and environmental impacts of such policies, a distributed modelling approach is needed to deal with the complexity of the system and the large environmental and socio-economic data requirements. Our objective is to integrate agro-hydrological modelling and economic analysis to support decision and policy making processes of BMP implementation. The integrated modelling system GIBSI was developed in an earlier study within the Canadian WEBs project (Watershed Evaluation of BMPs) to evaluate the influence of BMPs on water quality. The case study involved 30 and 15 year records of discharge and water quality measurements respectively, in the Beaurivage River watershed (Quebec, Canada). GIBSI provided a risk-based overview of the impact of BMPs (including vegetated riparian buffer strips, precision slurry application, conversion to grassland and no-till) in terms of sediment, nutrient and pesticide yields and loads. Input data included characteristics of reservoirs, land cover, soil, agricultural management, livestock management and point sources of pollution. The present study continues from there by first assessing the cost-effectiveness of different sets of BMPs, based on farm budgets and environmental criteria selected by the user. We subsequently examine monetary trade-offs between on-farm costs and social value of water quality improvements using cost-benefit ratios. Because water quality is a non-excludable and non-rivalrous good, its benefits to society are evaluated with non-market evaluation techniques mostly based on quality-constrained recreational use of water. From a policy perspective, cost-effectiveness analysis is very helpful in assisting the decision maker in the highly complex process of defining priorities with respect to BMP strategies. With a user-friendly interface for economic analysis integrated into GIBSI, watershed organizations and stakeholders can use such a tool to promote sustainable agricultural practices and water use. This submission is part of Watershed Evaluation of BMPs project (WEBs) funded by Agriculture and Agri-Food Canada and Ducks Unlimited Canada

The Development and Application of Spatiotemporal Metrics for the Characterization of Point Source FFCO2 Emissions and Dispersion

NASA Astrophysics Data System (ADS)

Roten, D.; Hogue, S.; Spell, P.; Marland, E.; Marland, G.

2017-12-01

There is an increasing role for high resolution, CO2 emissions inventories across multiple arenas. The breadth of the applicability of high-resolution data is apparent from their use in atmospheric CO2 modeling, their potential for validation of space-based atmospheric CO2 remote-sensing, and the development of climate change policy. This work focuses on increasing our understanding of the uncertainty in these inventories and the implications on their downstream use. The industrial point sources of emissions (power generating stations, cement manufacturing plants, paper mills, etc.) used in the creation of these inventories often have robust emissions characteristics, beyond just their geographic location. Physical parameters of the emission sources such as number of exhaust stacks, stack heights, stack diameters, exhaust temperatures, and exhaust velocities, as well as temporal variability and climatic influences can be important in characterizing emissions. Emissions from large point sources can behave much differently than emissions from areal sources such as automobiles. For many applications geographic location is not an adequate characterization of emissions. This work demonstrates the sensitivities of atmospheric models to the physical parameters of large point sources and provides a methodology for quantifying parameter impacts at multiple locations across the United States. The sensitivities highlight the importance of location and timing and help to highlight potential aspects that can guide efforts to reduce uncertainty in emissions inventories and increase the utility of the models.

Integrated research - water quality, sociological, economic, and modeling - in a regulated watershed: Jordan Lake, NC

Treesearch

Deanna Osmond; Mazdak Arabi; Caela O' Connell; Dana Hoag; Dan Line; Marzieh Motallebi; Ali Tasdighi

2016-01-01

Jordan Lake watershed is regulated by state rules in order to reduce nutrient loading from point and both agricultural and urban nonpoint sources. The agricultural community is expected to reduce nutrient loading by specific amounts that range from 35 - 0 percent nitrogen, and 5 - 0 percent phosphorus.

VizieR Online Data Catalog: ChaMP X-ray point source catalog (Kim+, 2007)

NASA Astrophysics Data System (ADS)

Kim, M.; Kim, D.-W.; Wilkes, B. J.; Green, P. J.; Kim, E.; Anderson, C. S.; Barkhouse, W. A.; Evans, N. R.; Ivezic, Z.; Karovska, M.; Kashyap, V. L.; Lee, M. G.; Maksym, P.; Mossman, A. E.; Silverman, J. D.; Tananbaum, H. D.

2009-01-01

We present the Chandra Multiwavelength Project (ChaMP) X-ray point source catalog with ~6800 X-ray sources detected in 149 Chandra observations covering ~10deg2. The full ChaMP catalog sample is 7 times larger than the initial published ChaMP catalog. The exposure time of the fields in our sample ranges from 0.9 to 124ks, corresponding to a deepest X-ray flux limit of f0.5-8.0=9x10-16ergs/cm2/s. The ChaMP X-ray data have been uniformly reduced and analyzed with ChaMP-specific pipelines and then carefully validated by visual inspection. The ChaMP catalog includes X-ray photometric data in eight different energy bands as well as X-ray spectral hardness ratios and colors. To best utilize the ChaMP catalog, we also present the source reliability, detection probability, and positional uncertainty. (10 data files).

Speckle contrast optical spectroscopy, a non-invasive, diffuse optical method for measuring microvascular blood flow in tissue

PubMed Central

Valdes, Claudia P.; Varma, Hari M.; Kristoffersen, Anna K.; Dragojevic, Tanja; Culver, Joseph P.; Durduran, Turgut

2014-01-01

We introduce a new, non-invasive, diffuse optical technique, speckle contrast optical spectroscopy (SCOS), for probing deep tissue blood flow using the statistical properties of laser speckle contrast and the photon diffusion model for a point source. The feasibility of the method is tested using liquid phantoms which demonstrate that SCOS is capable of measuring the dynamic properties of turbid media non-invasively. We further present an in vivo measurement in a human forearm muscle using SCOS in two modalities: one with the dependence of the speckle contrast on the source-detector separation and another on the exposure time. In doing so, we also introduce crucial corrections to the speckle contrast that account for the variance of the shot and sensor dark noises. PMID:25136500

Influence of Diffused Sourcers of Water Pollution In The Basin of Volga River

NASA Astrophysics Data System (ADS)

Vasilchenco, O.

The intensive development of industry and agriculture, great growth of cities in the last decades result in an increase of the nature water consumption and deterioration. Different anthropogenic load change characteristics of water objects regime and de- pletion and qualitative degradation of water resources. Sources of pollution are divided on two classes: controlled and uncontrolled. The first includes industrial and domestic wastewater disposal. Their discharge and concentration of pollutants are quite stable. These sources of pollution are identified as "point". Surface run-off from of cities, industrial platforms, agricultural object, navigation, recreation are not controlled have dispersed nature and are identification as diffuse. Pollution from such sources is es- timates by computation. Quantitative assumption of pollution amounts reaches water objects is complicated and independent problem. The significant amount of full-scale observations and information processes of concerning dissolved and fluidized frag- ments movement are required. According to available guidelines the part of the pollu- tant entering water objects, is about 1-10For estimation of pollution mass and transport are mathematical modeling. Preliminary calculations of contaminants transport for different territories under an- thropogenic impact of river-Volga basin were made either for point sources of pol- lution or for non-point. Received data made it possible to analyze the correlation of contaminant volumes, coming from different sources pollution.

A 34-meter VAWT (Vertical Axis Wind Turbine) point design

NASA Astrophysics Data System (ADS)

Ashwill, T. D.; Berg, D. E.; Dodd, H. M.; Rumsey, M. A.; Sutherland, H. J.; Veers, P. S.

The Wind Energy Division at Sandia National Laboratories recently completed a point design based on the 34-m Vertical Axis Wind Turbine (VAWT) Test Bed. The 34-m Test Bed research machine incorporates several innovations that improve Darrieus technology, including increased energy production, over previous machines. The point design differs minimally from the Test Bed; but by removing research-related items, its estimated cost is substantially reduced. The point design is a first step towards a Test-Bed-based commercial machine that would be competitive with conventional sources of power in the mid-1990s.

New developments in ALFT's soft x-ray point sources

NASA Astrophysics Data System (ADS)

Cintron, Dario F.; Guo, Xiaoming; Xu, Meisheng; Ye, Rubin; Antoshko, Yuriy; Antoshko, Yuriy; Drew, Steve; Philippe, Albert; Panarella, Emilio

2002-07-01

The new development in ALFT soft X-ray point source VSX-400 consists mainly of an improvement of the nozzle design to reduce the source size, as well as the introduction of a novel trigger system, capable of triggering the discharge hundreds of million of times without failure, and a debris removal system. Continuous operation for 8 hours at 20 kHz allows us to achieve 400 mW of useful soft X-ray radiation around 1 nm wavelength. In another regime of operation with a high energy machine, the VSX-Z, we have been able to achieve consistently 10 J of X-rays per pulse at a repetition rate that can reach 1 Hz with an input electrical energy of approximately 3 kJ and an efficiency in excess of 10-3.

VizieR Online Data Catalog: XMM-Newton point-source catalogue of the SMC (Sturm+, 2013)

NASA Astrophysics Data System (ADS)

Sturm, R.; Haberl, F.; Pietsch, W.; Ballet, J.; Hatzidimitriou, D.; Buckley, D. A. H.; Coe, M.; Ehle, M.; Filipovic, M. D.; La Palombara, N.; Tiengo, A.

2013-07-01

The XMM-Newton survey of the Small Magellanic Cloud (SMC) yields a complete coverage of the bar and eastern wing in the 0.2-12.0keV band. This catalogue comprises 3053 unique X-ray point sources and sources with moderate extent that have been reduced from 5236 individual detections found in observations between April 2000 and April 2010. Sources have a median position uncertainty of 1.3" (1σ) and limiting fluxes down to ~1*10-14erg/s/cm2 in the 0.2-4.5keV band, corresponding to 5*1033erg/s for sources in the SMC. Sources have been classified using hardness ratios, X-ray variability, and their multi-wavelength properties. In addition to the main-field (5.58deg2) available outer fields have been included in the catalogue, yielding a total field area of 6.32deg2. X-ray sources with high extent (>40", e.g. supernova remnants and galaxy cluster) have been presented by Haberl et al. (2012, Cat. J/A+A/545/A128) (2 data files).

Solar Energy and Other Appropriate Technologies for Small ...

EPA Pesticide Factsheets

This Region 2 research demonstration project presentation studied the efficacy of sustainable solar-powered water delivery and monitoring systems to reduce the economic burden of operating and maintaining Non-PRASA drinking water systems and to reduce the impact of climate change resulting from the use of fossil fuels in Puerto Rico. In Puerto Rico, petroleum (65%), natural gas (18%) and coal (16%) are imported to generate electricity resulting in electrical rates that are more than twice the US average. In 2012, only 1% of electricity came from renewable energy (US Energy Information Administration). One major cost for electricity for small communities in Puerto Rico is the transfer, treatment and distribution of drinking water. These small communities (Non-PRASA communities) are not able to afford electrical costs and many have abandoned their groundwater sources and reverted to unfiltered surface water systems, creating serious public health risks and non-compliance. Many Non-PRASA groundwater systems (141 out of 247) could use solar-powered pumps to extract and deliver groundwater. Solar power would also extend the life of system electrical components by improving the quality of electrical power supply. Solar power as a renewable energy source for Non-PRASA water systems is a viable approach that also reduces the impact of climate change in the Caribbean.

Robust sampling-sourced numerical retrieval algorithm for optical energy loss function based on log-log mesh optimization and local monotonicity preserving Steffen spline

NASA Astrophysics Data System (ADS)

Maglevanny, I. I.; Smolar, V. A.

2016-01-01

We introduce a new technique of interpolation of the energy-loss function (ELF) in solids sampled by empirical optical spectra. Finding appropriate interpolation methods for ELFs poses several challenges. The sampled ELFs are usually very heterogeneous, can originate from various sources thus so called "data gaps" can appear, and significant discontinuities and multiple high outliers can be present. As a result an interpolation based on those data may not perform well at predicting reasonable physical results. Reliable interpolation tools, suitable for ELF applications, should therefore satisfy several important demands: accuracy and predictive power, robustness and computational efficiency, and ease of use. We examined the effect on the fitting quality due to different interpolation schemes with emphasis on ELF mesh optimization procedures and we argue that the optimal fitting should be based on preliminary log-log scaling data transforms by which the non-uniformity of sampled data distribution may be considerably reduced. The transformed data are then interpolated by local monotonicity preserving Steffen spline. The result is a piece-wise smooth fitting curve with continuous first-order derivatives that passes through all data points without spurious oscillations. Local extrema can occur only at grid points where they are given by the data, but not in between two adjacent grid points. It is found that proposed technique gives the most accurate results and also that its computational time is short. Thus, it is feasible using this simple method to address practical problems associated with interaction between a bulk material and a moving electron. A compact C++ implementation of our algorithm is also presented.

Overview of the Texas Source Water Assessment Project

USGS Publications Warehouse

Ulery, Randy L.

2000-01-01

The 1996 Amendments to the Safe Drinking Water Act require, for the first time, that each state prepare a source water assessment for all PWS. Previously, Federal regulations focused on sampling and enforcement with emphasis on the quality of delivered water. These Amendments emphasize the importance of protecting the source water. States are required to determine the drinking-water source, the origin of contaminants monitored or the potential contaminants to be monitored, and the intrinsic susceptibility of the source water. Under the amendments to the Act, States must create SWAP Programs. The programs must include an individual source water assessment for each public water system regulated by the State. These assessments will determine whether an individual drinking water source is susceptible to contamination. During 1997?99, TNRCC and USGS staff met as subject-matter working groups to develop an approach to conducting Source Water Susceptibility Assessments (SWSA) and a draft workplan. The draft workplan was then presented to and reviewed by various stakeholder and technical advisory groups. Comments and suggestions from these groups were considered, and a final workplan was produced and presented to the EPA. After EPA approval, work formally began on the Texas SWAP Project. The project has an expected completion date of September 2002. At that time, initial SWSA of all Texas public water supplies should be complete. Ground-water supplies can be considered susceptible if a possible source of contamination (PSOC) exists in the contributing area for the public-supply well field or spring, the contaminant travel time to the well field or spring is short, and the soil zone, vadose zone, and aquifer-matrix materials are unlikely to adequately attenuate the contaminants associated with the PSOC. In addition, particular types of land use/cover within the contributing area may cause the supply to be deemed more susceptible to contamination. Finally, detection of various classes of constituents in water from wells in the vicinity of a public supply well may indicate susceptibility of the public-supply well even though there may be no identifiable PSOC or land use activity. Surface-water supplies are by nature susceptible to contamination from both point and non-point sources. The degree of susceptibility of a PWS to contamination can vary and is a function of the environmental setting, water and wastewater management practices, and land use/cover within a water supply's contributing watershed area. For example, a PWS intake downstream from extensive urban development may be more susceptible to non-point source contamination than a PWS intake downstream from a forested, relatively undeveloped watershed. Surface-water supplies are also susceptible to contamination from point sources, which may include permitted discharges, as well as accidental spills or other introduction of contaminants.

The US President's Malaria Initiative and under-5 child mortality in sub-Saharan Africa: A difference-in-differences analysis.

PubMed

Jakubowski, Aleksandra; Stearns, Sally C; Kruk, Margaret E; Angeles, Gustavo; Thirumurthy, Harsha

2017-06-01

Despite substantial financial contributions by the United States President's Malaria Initiative (PMI) since 2006, no studies have carefully assessed how this program may have affected important population-level health outcomes. We utilized multiple publicly available data sources to evaluate the association between introduction of PMI and child mortality rates in sub-Saharan Africa (SSA). We used difference-in-differences analyses to compare trends in the primary outcome of under-5 mortality rates and secondary outcomes reflecting population coverage of malaria interventions in 19 PMI-recipient and 13 non-recipient countries between 1995 and 2014. The analyses controlled for presence and intensity of other large funding sources, individual and household characteristics, and country and year fixed effects. PMI program implementation was associated with a significant reduction in the annual risk of under-5 child mortality (adjusted risk ratio [RR] 0.84, 95% CI 0.74-0.96). Each dollar of per-capita PMI expenditures in a country, a measure of PMI intensity, was also associated with a reduction in child mortality (RR 0.86, 95% CI 0.78-0.93). We estimated that the under-5 mortality rate in PMI countries was reduced from 28.9 to 24.3 per 1,000 person-years. Population coverage of insecticide-treated nets increased by 8.34 percentage points (95% CI 0.86-15.83) and coverage of indoor residual spraying increased by 6.63 percentage points (95% CI 0.79-12.47) after PMI implementation. Per-capita PMI spending was also associated with a modest increase in artemisinin-based combination therapy coverage (3.56 percentage point increase, 95% CI -0.07-7.19), though this association was only marginally significant (p = 0.054). Our results were robust to several sensitivity analyses. Because our study design leaves open the possibility of unmeasured confounding, we cannot definitively interpret these results as causal. PMI may have significantly contributed to reducing the burden of malaria in SSA and reducing the number of child deaths in the region. Introduction of PMI was associated with increased coverage of malaria prevention technologies, which are important mechanisms through which child mortality can be reduced. To our knowledge, this study is the first to assess the association between PMI and all-cause child mortality in SSA with the use of appropriate comparison groups and adjustments for regional trends in child mortality.

The US President’s Malaria Initiative and under-5 child mortality in sub-Saharan Africa: A difference-in-differences analysis

PubMed Central

Angeles, Gustavo; Thirumurthy, Harsha

2017-01-01

Background Despite substantial financial contributions by the United States President’s Malaria Initiative (PMI) since 2006, no studies have carefully assessed how this program may have affected important population-level health outcomes. We utilized multiple publicly available data sources to evaluate the association between introduction of PMI and child mortality rates in sub-Saharan Africa (SSA). Methods and findings We used difference-in-differences analyses to compare trends in the primary outcome of under-5 mortality rates and secondary outcomes reflecting population coverage of malaria interventions in 19 PMI-recipient and 13 non-recipient countries between 1995 and 2014. The analyses controlled for presence and intensity of other large funding sources, individual and household characteristics, and country and year fixed effects. PMI program implementation was associated with a significant reduction in the annual risk of under-5 child mortality (adjusted risk ratio [RR] 0.84, 95% CI 0.74–0.96). Each dollar of per-capita PMI expenditures in a country, a measure of PMI intensity, was also associated with a reduction in child mortality (RR 0.86, 95% CI 0.78–0.93). We estimated that the under-5 mortality rate in PMI countries was reduced from 28.9 to 24.3 per 1,000 person-years. Population coverage of insecticide-treated nets increased by 8.34 percentage points (95% CI 0.86–15.83) and coverage of indoor residual spraying increased by 6.63 percentage points (95% CI 0.79–12.47) after PMI implementation. Per-capita PMI spending was also associated with a modest increase in artemisinin-based combination therapy coverage (3.56 percentage point increase, 95% CI −0.07–7.19), though this association was only marginally significant (p = 0.054). Our results were robust to several sensitivity analyses. Because our study design leaves open the possibility of unmeasured confounding, we cannot definitively interpret these results as causal. Conclusions PMI may have significantly contributed to reducing the burden of malaria in SSA and reducing the number of child deaths in the region. Introduction of PMI was associated with increased coverage of malaria prevention technologies, which are important mechanisms through which child mortality can be reduced. To our knowledge, this study is the first to assess the association between PMI and all-cause child mortality in SSA with the use of appropriate comparison groups and adjustments for regional trends in child mortality. PMID:28609442

Mental health problems in the 10th grade and non-completion of upper secondary school: the mediating role of grades in a population-based longitudinal study

PubMed Central

2014-01-01

Background School drop-out is a problem all over the world with adverse life-course consequences. The aim of this paper is to study how internalising and externalising problems in the 10th grade are associated with non-completion of upper secondary school, and to examine the mediating role of grade points in the 10th grade across general academic and vocational tracks in upper secondary school. We also study the impact of health behaviour. Methods Population-based health surveys were linked with Norwegian registries on education and sociodemographic factors (n = 10 931). Mental health was assessed by the self-report Strengths and Difficulties Questionnaire. Logistic regression was used to analyse the relations between mental health and health behaviour in 10th grade and non-completion of upper secondary school. The mediating effect of grade points was studied by causal mediation analysis. Results Adolescents not completing upper secondary school reported more externalising problems and girls more internalising problems in the 10th grade, after adjustments. Smoking and physical inactivity increased the odds of non-completion of upper secondary school. Causal mediation analyses showed that a reduction in externalising problems of 10 percentage points led to lower rates of non-completion of 4–5 percentage points, and about three-quarters of this total effect was mediated by grades. For internalising problems the total effect was significant only for girls (1 percentage point), and the mediated effect of grades was about 30%. The effect of mental health problems on school dropout was mainly the same in both vocational and general tracks. Conclusions Assuming a causal relationship from mental health problems to school performance, this study suggests that externalising problems impair educational attainment. A reduction of such problems may improve school performance, reduce school drop-out and reduce the adverse life-course consequences. PMID:24406098

Integrated watershed approach in controlling point and non-point source pollution within Zelivka drinking water reservoir.

PubMed

Holas, J; Hrncir, M

2002-01-01

An agricultural watershed involves manipulation of soil, water and other natural resources and it has profound impacts on ecosystems. To manage these complex issues, we must understand causes and consequences and interactions-related transport of pollutants, quality of the environment, mitigation measures and policy measures. A ten year period of economic changes has been analysed with respect to sustainable development concerning Zelivka drinking water reservoir and its watershed, where agriculture and forestry are the main human activities. It is recommended that all land users within a catchment area should receive payments for their contribution to water cycle management. Setting up the prevention principles and best management practices financially subsidized by a local water company has been found very effective in both point and non-point source pollution abatement, and the newly prepared Clean Water Programme actively involves local municipal authorities as well. The first step based on systems analysis was to propose effective strategies and select alternative measures and ways for their financing. Long term monitoring of nutrient loads entering the reservoir and hazardous events statistics resulted in maps characterising the territory including vulnerable zones and risk factors. Financing involves providing annual payments to farmers, who undertake to manage specified areas of their land in a particular way and one-off payments to realise proposed issues ensuring soil conservation and watershed ecosystem benefits.

Transcranial ultrasonic therapy based on time reversal of acoustically induced cavitation bubble signature

PubMed Central

Gâteau, Jérôme; Marsac, Laurent; Pernot, Mathieu; Aubry, Jean-Francois; Tanter, Mickaël; Fink, Mathias

2010-01-01

Brain treatment through the skull with High Intensity Focused Ultrasound (HIFU) can be achieved with multichannel arrays and adaptive focusing techniques such as time-reversal. This method requires a reference signal to be either emitted by a real source embedded in brain tissues or computed from a virtual source, using the acoustic properties of the skull derived from CT images. This non-invasive computational method focuses with precision, but suffers from modeling and repositioning errors that reduce the accessible acoustic pressure at the focus in comparison with fully experimental time-reversal using an implanted hydrophone. In this paper, this simulation-based targeting has been used experimentally as a first step for focusing through an ex vivo human skull at a single location. It has enabled the creation of a cavitation bubble at focus that spontaneously emitted an ultrasonic wave received by the array. This active source signal has allowed 97%±1.1% of the reference pressure (hydrophone-based) to be restored at the geometrical focus. To target points around the focus with an optimal pressure level, conventional electronic steering from the initial focus has been combined with bubble generation. Thanks to step by step bubble generation, the electronic steering capabilities of the array through the skull were improved. PMID:19770084

Monitoring bacterial contamination of piped water supply in rural coastal Bangladesh.

PubMed

Ahsan, Md Sabbir; Akber, Md Ali; Islam, Md Atikul; Kabir, Md Pervez; Hoque, Md Ikramul

2017-10-31

Safe drinking water is scarce in southwest coastal Bangladesh because of unavailability of fresh water. Given the high salinity of both groundwater and surface water in this area, harvested rainwater and rain-fed pond water became the main sources of drinking water. Both the government and non-government organizations have recently introduced pipe water supply in the rural coastal areas to ensure safe drinking water. We assessed the bacteriological quality of water at different points along the piped water distribution system (i.e., the source, treatment plant, household taps, street hydrants, and household storage containers) of Mongla municipality under Mongla Upazila in Bagerhat district. Water samples were collected at 2-month interval from May 2014 to March 2015. Median E. coli and total coliform counts at source, treatment plant, household taps, street hydrants, and household storage containers were respectively 225, 4, 7, 7, and 15 cfu/100 ml and 42,000, 545, 5000, 6150, and 18,800 cfu/100 ml. Concentrations of both of the indicator bacteria reduced after treatment, although it did not satisfy the WHO drinking water standards. However, re-contamination in distribution systems and household storage containers indicate improper maintenance of distribution system and lack of personal hygiene.

Fused oblique incidence reflectometry and confocal fluorescence microscopy

NASA Astrophysics Data System (ADS)

Risi, Matthew D.; Rouse, Andrew R.; Gmitro, Arthur F.

2011-03-01

Confocal microendoscopy provides real-time high resolution cellular level images via a minimally invasive procedure, but relies on exogenous fluorophores, has a relatively limited penetration depth (100 μm) and field of view (700 μm), and produces a high rate of detailed information to the user. A new catheter based multi-modal system has been designed that combines confocal imaging and oblique incidence reflectometry (OIR), which is a non-invasive method capable of rapidly extracting tissue absorption, μa, and reduced scattering, μ's, spectra from tissue. The system builds on previous developments of a custom slit-scan multi-spectral confocal microendoscope and is designed to rapidly switch between diffuse spectroscopy and confocal fluorescence imaging modes of operation. An experimental proof-of-principle catheter has been developed that consists of a fiber bundle for traditional confocal fluorescence imaging and a single OIR source fiber which is manually redirected at +/- 26 degrees. Diffusely scattered light from each orientation of the source fiber is collected via the fiber bundle, with a frame of data representing spectra collected at a range of distances from the OIR source point. Initial results with intralipid phantoms show good agreement to published data over the 550-650 nm spectral range. We successfully imaged and measured the optical properties of rodent cardiac muscle.

Effect of traffic restriction on reducing ambient volatile organic compounds (VOCs): Observation-based evaluation during a traffic restriction drill in Guangzhou, China

NASA Astrophysics Data System (ADS)

Huang, Xinyu; Zhang, Yanli; Yang, Weiqiang; Huang, Zuzhao; Wang, Yujun; Zhang, Zhou; He, Quanfu; Lü, Sujun; Huang, Zhonghui; Bi, Xinhui; Wang, Xinming

2017-07-01

Traffic restriction (TR) is a widely adopted control measure in case of heavy air pollution particularly in urban areas, yet it is hard to evaluate the effect of TR on reducing VOC emissions based on monitoring data since ambient VOC mixing ratios are influenced not only by source emissions but also by meteorological conditions and atmospheric degradation. Here we collected air samples for analysis of VOCs before, during and after a TR drill carried out in Guangzhou in September 2010 at both a roadside and a rooftop (∼50 m above the ground) site. TR measures mainly included the "odd-even license" rule and banning high-emitting "yellow label" vehicles. The mixing ratios of non-methane hydrocarbons (NMHCs) did not show significant changes at the roadside site with total NMHCs of 39.0 ± 11.8 ppbv during non-TR period and 39.1 ± 14.8 ppbv during TR period, whereas total NMHCs decreased from 30.4 ± 14.3 ppbv during the non-TR period to 22.1 ± 10.6 ppbv during the TR period at rooftop site. However, the ratios of methyl tert-butyl ether (MTBE), benzene and toluene against carbon monoxide (MTBE/CO, T/CO and B/CO) at the both sampling sites dropped significantly. The ratios of toluene to benzene (T/B) instead increased significantly. Changes in these ratios all consistently indicated reduced input from traffic emissions particularly gasoline vehicles. Source attribution by positive matrix factorization (PMF) confirmed that during the TR period gasoline vehicles contributed less VOCs in percentages while industrial sources, biomass burning and LPG shared larger percentages. Assuming that emissions from industrial sources remained unchanged during the TR and non-TR periods, we further used the PMF-retrieved contribution percentages to deduce the reduction rate of traffic-related VOC emissions, and obtained a reduction rate of 31% based on monitoring data at the roadside site and of 34% based on the monitoring data at the rooftop site. Considering VOC emissions from all sources in Guangzhou city, the TR control measures adopted could reduce VOC up to 15%.

Trend analysis of a tropical urban river water quality in Malaysia.

PubMed

Othman, Faridah; M E, Alaa Eldin; Mohamed, Ibrahim

2012-12-01

Rivers play a significant role in providing water resources for human and ecosystem survival and health. Hence, river water quality is an important parameter that must be preserved and monitored. As the state of Selangor and the city of Kuala Lumpur, Malaysia, are undergoing tremendous development, the river is subjected to pollution from point and non-point sources. The water quality of the Klang River basin, one of the most densely populated areas within the region, is significantly degraded due to human activities as well as urbanization. Evaluation of the overall river water quality status is normally represented by a water quality index (WQI), which consists of six parameters, namely dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, suspended solids, ammoniacal nitrogen and pH. The objectives of this study are to assess the water quality status for this tropical, urban river and to establish the WQI trend. Using monthly WQI data from 1997 to 2007, time series were plotted and trend analysis was performed by employing the first-order autocorrelated trend model on the moving average values for every station. The initial and final values of either the moving average or the trend model were used as the estimates of the initial and final WQI at the stations. It was found that Klang River water quality has shown some improvement between 1997 and 2007. Water quality remains good in the upper stream area, which provides vital water sources for water treatment plants in the Klang valley. Meanwhile, the water quality has also improved in other stations. Results of the current study suggest that the present policy on managing river quality in the Klang River has produced encouraging results; the policy should, however, be further improved alongside more vigorous monitoring of pollution discharge from various point sources such as industrial wastewater, municipal sewers, wet markets, sand mining and landfills, as well as non-point sources such as agricultural or urban runoff and commercial activity.

Factors affecting low summer dissolved oxygen concentrations in Mississippi Delta bayous

USDA-ARS?s Scientific Manuscript database

Streams in watersheds supporting intensive row-crop agriculture are vulnerable to ecological degradation due to non-point source pollutants such as nutrients. Low gradient streams such as bayous are especially susceptible to pollutants due to increased water residence time, and they often exhibit po...

MANAGEMENT OF DIFFUSE POLLUTION IN AGRICULTURAL WATERSHEDS: LESSONS FROM THE MINNESOTA RIVER BASIN. (R825290)

EPA Science Inventory

Abstract

The Minnesota River (Minnesota, USA) receives large non-point source pollutant loads. Complex interactions between agricultural, state agency, environmental groups, and issues of scale make watershed management difficult. Subdividing the basin's 12 major water...

IMPERVIOUS SURFACES AND STREAMFLOW DISCHARGE: A HISTORICAL REMOTE SENSING PERSPECTIVE IN A NORTHERN VIRGINIA SUBWATERSHED

EPA Science Inventory

Impervious surfaces are a leading contributor to non-point-source water pollution in urban watersheds. These surfaces include such features as roads, parking lots, rooftops and driveways. Aerial photography provides a historical vehicle for determining impervious surface growth a...

Mapping ecosystem service indicators in a Great Lakes estuarine Area of Concern

EPA Science Inventory

Estuaries provide multiple ecosystem services from which humans benefit. Currently, thirty-six Great Lakes estuaries in the United States and Canada are designated as Areas of Concern (AOCs) due to a legacy of chemical contamination, degraded habitat, and non-point-source polluti...

ESTIMATING DIFFUSE STORMWATER NUTRIENT LOADS FROM SUBURBAN LANDSCAPES TO THE NAVESINK ESTUARY, NEW JERSEY

EPA Science Inventory

Hitherto, stormwater runoff from suburban land-uses has been largely unregulated and designated as a non-point source. Phase II of the Clean Water Act will require permits under the National Pollutant Discharge Elimination System for stormwater discharges from municipal separate ...

ESTIMATING DIFFUSE STORMWATER NUTRIENT LOADS FROM SUBURBAN LANDSCAPES IN THE NAVESINK ESTUARY, NEW JERSEY

EPA Science Inventory

Hitherto, stormwater runoff from suburban land-uses has been largely unregulated and designated as a non-point source. Phase II of the Clean Water Act now requires permits under the National Pollutant Discharge Elimination System for stormwater discharges from municipal separate...

Evaluation of a stepwise, multi-objective, multi-variable parameter optimization method for the APEX model

USDA-ARS?s Scientific Manuscript database

Hydrologic models are essential tools for environmental assessment of agricultural non-point source pollution. The automatic calibration of hydrologic models, though efficient, demands significant computational power, which can limit its application. The study objective was to investigate a cost e...