Deep magma accumulation at Nyamulagira volcano in 2011 detected by GNSS observations

NASA Astrophysics Data System (ADS)

Ji, Kang Hyeun; Stamps, D. Sarah; Geirsson, Halldor; Mashagiro, Niche; Syauswa, Muhindo; Kafudu, Benjamin; Subira, Josué; d'Oreye, Nicolas

2017-10-01

People in the area of the Virunga Mountains, along the borders of the Democratic Republic of Congo, Rwanda, and Uganda, are at very high natural risk due to active volcanism. A Global Navigation Satellite System (GNSS) network, KivuGNet (Kivu Geodetic Network), has operated since 2009 for monitoring and research of the deformation of Nyamulagira and Nyiragongo volcanoes as well as tectonic deformation in the region. We detected an inflationary signal from the position time-series observed in the network using our detection method, which is a combination of Kalman filtering and principal component analysis. The inflation event began in October 2010 and lasted for about 6 months prior to the 2011-2012 eruption at Nyamulagira volcano. The pre-eruptive inflationary signal is much weaker than the co-eruptive signal, but our method successfully detected the signal. The maximum horizontal and vertical displacements observed are ∼9 mm and ∼5 mm, respectively. A Mogi point source at a depth >10 km can explain the displacement field. This suggests that a relatively deep source for the magma chamber generated the inflationary signal. The deep reservoir that is the focus of this study may feed a shallower magma chamber, which is the likely source of the 2011-2012 eruption. Continuous monitoring of the volcanic activity is essential for understanding the eruption cycle and assessing potential volcanic hazards.

Volcanic Surface Deformation in Dominica From GPS Geodesy: Results From the 2007 NSF- REU Site

NASA Astrophysics Data System (ADS)

Murphy, R.; James, S.; Styron, R. H.; Turner, H. L.; Ashlock, A.; Cavness, C.; Collier, X.; Fauria, K.; Feinstein, R.; Staisch, L.; Williams, B.; Mattioli, G. S.; Jansma, P. E.; Cothren, J.

2007-12-01

GPS measurements have been collected on the island of Dominica in the Lesser Antilles between 2001 and 2007, with five month-long campaigns completed in June of each year supported in part by a NSF REU Site award for the past two years. All GPS data were collected using dual-frequency, code-phase receivers and geodetic-quality antenna, primarily choke rings. Three consecutive 24 hr observation days were normally obtained for each site. Precise station positions were estimated with GIPSY-OASISII using an absolute point positioning strategy and final, precise orbits, clocks, earth orientation parameters, and x-files. All position estimates were updated to ITRF05 and a revised Caribbean Euler pole was used to place our observations in a CAR-fixed frame. Time series were created to determine the velocity of each station. Forward and inverse elastic half-space models with planar (i.e. dike) and Mogi (i.e. point) sources were investigated. Inverse modeling was completed using a downhill simplex method of function minimization. Selected site velocities were used to create appropriate models for specific regions of Dominica, which correspond to known centers of pre-historic volcanic or recent shallow, seismic activity. Because of the current distribution of GPS sites with robust velocity estimates, we limit our models to possible magmatic activity in the northern, proximal to the volcanic centers of Morne Diablotins and Morne aux Diables, and southern, proximal to volcanic centers of Soufriere and Morne Plat Pays, regions of the island. Surface deformation data from the northernmost sites may be fit with the development of a several km-long dike trending approximately northeast- southwest. Activity in the southern volcanic centers is best modeled by an expanding point source at approximately 1 km depth.

Frequency-Based Precursory Acoustic Emission Failure Sequences In Sedimentary And Igneous Rocks Under Uniaxial Compression

NASA Astrophysics Data System (ADS)

Colin, C.; Anderson, R. C.; Chasek, M. D.; Peters, G. H.; Carey, E. M.

2016-12-01

Identifiable precursors to rock failure have been a long pursued and infrequently encountered phenomena in rock mechanics and acoustic emission studies. Since acoustic emissions in compressed rocks were found to follow the Gutenberg-Richter law, failure-prediction strategies based on temporal changes in b-value have been recurrent. In this study, we extend on the results of Ohnaka and Mogi [Journal of Geophysical Research, Vol. 87, No. B5, p. 3873-3884, (1982)], where the bulk frequency characteristics of rocks under incremental uniaxial compression were observed in relation to changes in b-value before and after failure. Based on the proposition that the number of low-frequency acoustic emissions is proportional to the number of high-amplitude acoustic emissions in compressed rocks, Ohnaka and Mogi (1982) demonstrated that b-value changes in granite and andesite cores under incremental uniaxial compression could be expressed in terms of the percent abundance of low-frequency events. In this study, we attempt to demonstrate that the results of Ohnaka and Mogi (1982) hold true for different rock types (basalt, sandstone, and limestone) and different sample geometries (rectangular prisms). In order to do so, the design of the compression tests was kept similar to that of Ohnaka and Mogi (1982). Two high frequency piezoelectric transducers of 1 MHz and a 500 kHz coupled to the sides of the samples detected higher and lower frequency acoustic emission signals. However, rather than gathering parametric data from an analog signal using a counter as per Ohnaka and Mogi (1982), we used an oscilloscope as an analog to digital converter interfacing with LabVIEW 2015 to record the complete waveforms. The digitally stored waveforms were then processed, detecting acoustic emission events using a statistical method, and filtered using a 2nd order Butterworth filter. In addition to calculating the percent abundance of low-frequency events over time, the peak frequency of the acoustic emissions over time was observable due to the digital method of waveform capture. This allows for a more direct comparison between frequency characteristics and b-values of rocks under compression and investigates the viability of observing frequency behavior over time as a method of rock failure prediction.

Quiescent deformation of the Aniakchak Caldera, Alaska mapped by InSAR

USGS Publications Warehouse

Kwoun, Oh-Ig; Lu, Zhong; Neal, Christina; Wicks, Charles W.

2006-01-01

The 10-km-wide caldera of the historically active Aniakchak volcano, Alaska, subsides ∼13 mm/yr, based on data from 19 European Remote Sensing Satellite (ERS-1 and ERS-2) interferometric synthetic aperture radar (InSAR) images from 1992 through 2002. The pattern of subsidence does not reflect the distribution of pyroclastic deposits from the last eruption in 1931 and therefore is not related to compaction of fragmental debris. Weighted least-squares inversion of the deformation maps indicates a relatively constant subsidence rate. Modeling the deformation with a Mogi point source locates the source of subsidence at ∼4 km below the central caldera floor, which is consistent with the inferred depth of magma storage before the 1931 eruption. Magmatic CO2 and He have been measured at a warm soda spring within the caldera, and several sub-boiling fumaroles persist elsewhere in the caldera. These observations suggest that recent subsidence can be explained by the cooling or degassing of a shallow magma body (∼4 km deep), and/or the reduction of the pore-fluid pressure of a cooling hydrothermal system. Ongoing deformation of the volcano detected by InSAR, in combination with magmatic gas output from at least one warm spring, and infrequent low-level bursts of seismicity below the caldera, indicate that the volcanic system is still active and requires close attention for the timely detection of possible hazards.

Analysis of surface deformation during the eruptive process of El Hierro Island (Canary Islands, Spain): Detection, Evolution and Forecasting.

NASA Astrophysics Data System (ADS)

Berrocoso, M.; Fernandez-Ros, A.; Prates, G.; Martin, M.; Hurtado, R.; Pereda, J.; Garcia, M. J.; Garcia-Cañada, L.; Ortiz, R.; Garcia, A.

2012-04-01

The surface deformation has been an essential parameter for the onset and evolution of the eruptive process of the island of El Hierro (October 2011) as well as for forecasting changes in seismic and volcanic activity during the crisis period. From GNSS-GPS observations the reactivation is early detected by analizing the change in the deformation of the El Hierro Island regional geodynamics. It is found that the surface deformation changes are detected before the occurrence of seismic activity using the station FRON (GRAFCAN). The evolution of the process has been studied by the analysis of time series of topocentric coordinates and the variation of the distance between stations on the island of El Hierro (GRAFCAN station;IGN network; and UCA-CSIC points) and LPAL-IGS station on the island of La Palma. In this work the main methodologies and their results are shown: •The location (and its changes) of the litospheric pressure source obtained by applying the Mogi model. •Kalman filtering technique for high frequency time series, used to make the forecasts issued for volcanic emergency management. •Correlations between deformation of the different GPS stations and their relationship with seismovolcanic settings.

Real-time source deformation modeling through GNSS permanent stations at Merapi volcano (Indonesia

NASA Astrophysics Data System (ADS)

Beauducel, F.; Nurnaning, A.; Iguchi, M.; Fahmi, A. A.; Nandaka, M. A.; Sumarti, S.; Subandriyo, S.; Metaxian, J. P.

2014-12-01

Mt. Merapi (Java, Indonesia) is one of the most active and dangerous volcano in the world. A first GPS repetition network was setup and periodically measured since 1993, allowing detecting a deep magma reservoir, quantifying magma flux in conduit and identifying shallow discontinuities around the former crater (Beauducel and Cornet, 1999;Beauducel et al., 2000, 2006). After the 2010 centennial eruption, when this network was almost completely destroyed, Indonesian and Japanese teams installed a new continuous GPS network for monitoring purpose (Iguchi et al., 2011), consisting of 3 stations located at the volcano flanks, plus a reference station at the Yogyakarta Observatory (BPPTKG).In the framework of DOMERAPI project (2013-2016) we have completed this network with 5 additional stations, which are located on the summit area and volcano surrounding. The new stations are 1-Hz sampling, GNSS (GPS + GLONASS) receivers, and near real-time data streaming to the Observatory. An automatic processing has been developed and included in the WEBOBS system (Beauducel et al., 2010) based on GIPSY software computing precise daily moving solutions every hour, and for different time scales (2 months, 1 and 5 years), time series and velocity vectors. A real-time source modeling estimation has also been implemented. It uses the depth-varying point source solution (Mogi, 1958; Williams and Wadge, 1998) in a systematic inverse problem model exploration that displays location, volume variation and 3-D probability map.The operational system should be able to better detect and estimate the location and volume variations of possible magma sources, and to follow magma transfer towards the surface. This should help monitoring and contribute to decision making during future unrest or eruption.

Steady subsidence of Medicine Lake volcano, northern California, revealed by repeated leveling surveys

USGS Publications Warehouse

Dzurisin, D.; Poland, Michael P.; Burgmann, R.

2002-01-01

Leveling surveys of a 193-km circuit across Medicine Lake volcano (MLV) in 1954 and 1989 show that the summit area subsided by as much as 302 ?? 30 mm (-8.6 ?? 0.9 mm/yr) with respect to a datum point near Bartle, California, 40 km to the southwest. This result corrects an error in the earlier analysis of the same data by Dzurisin et al. [1991], who reported the subsidence rate as -11.1 ?? 1.2 mm/yr. The subsidence pattern extends across the entire volcano, with a surface area of nearly 2000 km2. Two areas of localized subsidence by as much as 20 cm can be attributed to shallow normal faulting near the volcano's periphery. Surveys of an east-west traverse across Lava Beds National Monument on the north flank of the volcano in 1990 and of a 23-km traverse across the summit area in 1999 show that subsidence continued at essentially the same rate during 1989-1999 as 1954-1989. Volcano-wide subsidence can be explained by either a point source of volume loss (Mogi) or a contracting horizontal rectangular dislocation (sill) at a depth of 10-11 km. Volume loss rate estimates range from 0.0013 to 0.0032 km3/yr, depending mostly on the source depth estimate and source type. Based on first-order quantitative considerations, we can rule out that the observed subsidence is due to volume loss from magma withdrawal, thermal contraction, or crystallizing magma at depth. Instead, we attribute the subsidence and faulting to: (1 gravitational loading of thermally weakened crust by the mass of the volcano and associated intrusive rocks, and (2) thinning of locally weakened crust by Basin and Range deformation. The measured subsidence rate exceeds long-term estimates from drill hole data, suggesting that over long timescales, steady subsidence and episodic uplift caused by magmatic intrusions counteract each other to produce the lower net subsidence rate.

Episodic inflation of Akutan volcano, Alaska revealed from GPS and InSAR time series

NASA Astrophysics Data System (ADS)

DeGrandpre, K.; Lu, Z.; Wang, T.

2016-12-01

Akutan volcano is one of the most active volcanoes located long the Aleutian arc. At least 27 eruptions have been noted since 1790 and an intense swarm of volcano-tectonic earthquakes occurred in 1996. Surface deformation after the 1996 earthquake sequence has been studied using GPS and Interferometric Synthetic Aperture Radar (InSAR) separately, yet models created from these datasets require different mechanisms to produce the observed surface deformation: an inflating Mogi source results in the best approximation of displacement observed from GPS data, whereas an opening dyke is the best fit to deformation measured from InSAR. A recent study using seismic data revealed complex magmatic structures beneath the caldera, suggesting that the surface deformation may reflect more complicated mechanisms that cannot be estimated using one type of data alone. Here we integrate the surface deformation measured from GPS and InSAR to better understand the magma plumbing system beneath Akutan volcano. GPS time-series at 12 stations from 2006 to 2016 were analyzed, and two transient episodes of inflation in 2008 and 2014 were detected. These GPS stations are, however, too sparse to reveal the spatial distribution of the surface deformation. In order to better define the spatial extent of this inflation four tracks of Envisat data acquired during 2003-2010 and one track of TerraSAR-X data acquired from 2010 to 2016 were processed to produce high-resolution maps of surface deformation. These deformation maps show a consistently uplifting area on the northwestern flank of the volcano. We inverted for the source parameters required to produce the inflation using GPS, InSAR, and a dataset of GPS and InSAR measurements combined, to find that a deep Mogi source below a shallow dyke fit these datasets best. From the TerraSAR-X data, we were also able to measure the subsidence inside the summit caldera due to fumarole activity to be as high as 10 mm/yr. The complex spatial and temporal deformation patterns observed using GPS and InSAR at Akutan volcano imply that the magma plumbing system beneath the island inflates episodically from both deep and shallow sources of varying geometry which is responsible for the uplift observed in 2008 and 2014, but has yet led to an eruption.

Is internal friction friction?

USGS Publications Warehouse

Savage, J.C.; Byerlee, J.D.; Lockner, D.A.

1996-01-01

Mogi [1974] proposed a simple model of the incipient rupture surface to explain the Coulomb failure criterion. We show here that this model can plausibly be extended to explain the Mohr failure criterion. In Mogi's model the incipient rupture surface immediately before fracture consists of areas across which material integrity is maintained (intact areas) and areas across which it is not (cracks). The strength of the incipient rupture surface is made up of the inherent strength of the intact areas plus the frictional resistance to sliding offered by the cracked areas. Although the coefficient of internal friction (slope of the strength versus normal stress curve) depends upon both the frictional and inherent strengths, the phenomenon of internal friction can be identified with the frictional part. The curvature of the Mohr failure envelope is interpreted as a consequence of differences in damage (cracking) accumulated in prefailure loading at different confining pressures.

Magma Dynamics at Axial Seamount, Juan de Fuca Ridge, from Seafloor Deformation Data

NASA Astrophysics Data System (ADS)

Baumgardt, E.; Nooner, S. L.; Chadwick, W.

2014-12-01

Axial Seamount is located about 480 km west of the Oregon coast at the intersection of the Cobb hotspot and the Juan de Fuca Ridge. Two eruptions have been observed since routine observations began in the 1990's, one in January 1998 and the other in April 2011. Precise bottom pressure measurements have documented an inflation/deflation cycle within Axial's summit caldera. The slow inflation observed at the center of the caldera was punctuated by sudden rapid deflation of 3.2 m during the 1998 eruption and 2.4 m during the 2011 eruption. Pressure data collected in September 2013 from continuously recording bottom pressure recorders and campaign-style measurements with an ROV indicates that Axial Seamount inflated 1.57 m from April 2011 to September 2013 at an average inflation rate of 61 cm/yr, meaning it had already recovered more than 65% of the deflation from the 2011 eruption within just 2.4 years. The geometry and location of the deformation source is not well constrained by the spatially-sparse pressure data, particularly for the most recent co-eruption deflation and post-eruption inflation signals. Here, we use geodetic data collected in September 2013 to test the fit of multiple numerical models of increasing complexity. We show that for this time period (since April 2011) neither a simple point deformation source (Mogi model) nor an oblate spheroid (penny-shaped crack) provide a good fit to the data. We then use finite element models to build more complex inflation geometries, guided by recent seismically imaged magma reservoirs, in an attempt to understand the source(s) of the observed deformation pattern. The recent seismic data provide good constraints on magma reservoir geometry and show the most robust melt occurs under the southeast part of the caldera at Axial. However, previous geodetic measurements at Axial have consistently shown a deformation source near the caldera center. We use numerical modeling to attempt to reconcile these differences.

LibHalfSpace: A C++ object-oriented library to study deformation and stress in elastic half-spaces

NASA Astrophysics Data System (ADS)

Ferrari, Claudio; Bonafede, Maurizio; Belardinelli, Maria Elina

2016-11-01

The study of deformation processes in elastic half-spaces is widely employed for many purposes (e.g. didactic, scientific investigation of real processes, inversion of geodetic data, etc.). We present a coherent programming interface containing a set of tools designed to make easier and faster the study of processes in an elastic half-space. LibHalfSpace is presented in the form of an object-oriented library. A set of well known and frequently used source models (Mogi source, penny shaped horizontal crack, inflating spheroid, Okada rectangular dislocation, etc.) are implemented to describe the potential usage and the versatility of the library. The common interface given to library tools enables us to switch easily among the effects produced by different deformation sources that can be monitored at the free surface. Furthermore, the library also offers an interface which simplifies the creation of new source models exploiting the features of object-oriented programming (OOP). These source models can be built as distributions of rectangular boundary elements. In order to better explain how new models can be deployed some examples are included in the library.

Ground surface deformation patterns, magma supply, and magma storage at Okmok volcano, Alaska, from InSAR analysis: 1. Intereruption deformation, 1997–2008

USGS Publications Warehouse

Lu, Zhong; Dzurisin, Daniel; Biggs, Juliet; Wicks, Charles; McNutt, Steve

2010-01-01

Starting soon after the 1997 eruption at Okmok volcano and continuing until the start of the 2008 eruption, magma accumulated in a storage zone centered ~3.5 km beneath the caldera floor at a rate that varied with time. A Mogi-type point pressure source or finite sphere with a radius of 1 km provides an adequate fit to the deformation field portrayed in time-sequential interferometric synthetic aperture radar images. From the end of the 1997 eruption through summer 2004, magma storage increased by 3.2–4.5 × 107 m3, which corresponds to 75–85% of the magma volume erupted in 1997. Thereafter, the average magma supply rate decreased such that by 10 July 2008, 2 days before the start of the 2008 eruption, magma storage had increased by 3.7–5.2 × 107 m3 or 85–100% of the 1997 eruption volume. We propose that the supply rate decreased in response to the diminishing pressure gradient between the shallow storage zone and a deeper magma source region. Eventually the effects of continuing magma supply and vesiculation of stored magma caused a critical pressure threshold to be exceeded, triggering the 2008 eruption. A similar pattern of initially rapid inflation followed by oscillatory but generally slowing inflation was observed prior to the 1997 eruption. In both cases, withdrawal of magma during the eruptions depressurized the shallow storage zone, causing significant volcano-wide subsidence and initiating a new intereruption deformation cycle.

Studies of volcanoes of Alaska by satellite radar interferometry

USGS Publications Warehouse

Lu, Z.; Wicks, C.; Dzurisin, D.; Thatcher, W.; Power, J.; ,

2000-01-01

Interferometric synthetic aperture radar (InSAR) has provided a new imaging geodesy technique to measure the deformation of volcanoes at tens-of-meter horizontal resolution with centimeter to subcentimeter vertical precision. The two-dimensional surface deformation data enables the construction of detailed numerical models allowing the study of magmatic and tectonic processes beneath volcanoes. This paper summarizes our recent: InSAR studies over the Alaska-Aleutian volcanoes, which include New Trident, Okmok, Akutan, Augustine, Shishaldin, and Westdahl volcanoes. The first InSAR surface deformation over the Alaska volcanoes was applied to New Trident. Preliminary InSAR study suggested that New Trident volcano experienced several centimeters inflation from 1993 to 1995. Using the InSAR technique, we studied the 1997 eruption of Okmok. We have measured ???1.4 m deflation during the eruption, ???20 cm pre-eruptive inflation during 1992 to 1995, and >10 cm post-eruptive inflation within a year after the eruption, and modeled the deformations using Mogi sources. We imaged the ground surface deformation associated with the 1996 seismic crisis over Akutan volcano. Although seismic swarm did not result in an eruption, we found that the western part of the volcano uplifted ???60 cm while the eastern part of the island subsided. The majority of the complex deformation field at the Akutan volcano was modeled by dike intrusion and Mogi inflation sources. Our InSAR results also indicate that the pyroclastic flows from last the last eruption have been undergoing contraction/subsidence at a rate of about 3 cm per year since 1992. InSAR measured no surface deformation before and during the 1999 eruption of Shishaldin and suggested the eruption may be a type of open system. Finally, we applied satellite radar interferometry to Westdahl volcano which erupted 1991 and has been quiet since. We discovered this volcano had inflated about 15 cm from 1993 to 1998. In summary, satellite radar interferometry can not only be used to study a volcanic eruption, but also to detect aseismic deformation at quiescent volcanoes preceding a seismic swarm; it is a useful technique to study volcanic eruptions as well as to guide scientists to better focus their monitoring efforts.

Economic valuation of the Emas waterfall, Mogi-Guaçu River, SP, Brazil.

PubMed

Peixer, Janice; Giacomini, Henrique C; Petrere, Miguel

2011-12-01

The Emas waterfall in Mogi-Guaçu River is regionally recognized as an important fishing spot and touristic place. The first reports of the professional and sport fishing there date back from the 30's, which is the same period when the tourism took place. The present paper provides an environmental valuation of this place and an assessment of the differences among the major groups of people using the area. During 2006 we interviewed 33 professional fishers, 107 sport fishers, 45 tourists and 103 excursionists in order to estimate the Willingness to Pay (WTP) for each category and to analyze the influence of socioeconomic factors by means of logistic regressions and ANCOVAs. The WTP of professional fisher was significantly influenced by age and education, and the WTP for the sport fishers was influenced by the family income. The variables that influenced the tourists' and excursionists' WTP were sex and education. The total annual aggregated value to maintain the waterfall in the current conditions was estimated in US$ 11.432.128, and US$ 55.424.283 to restore it.

Automatic classification of reforested Pinus SPP and Eucalyptus SPP in Mogi-Guacu, SP, Brazil, using LANDSAT data

NASA Technical Reports Server (NTRS)

Dejesusparada, N. (Principal Investigator); Shimabukuro, Y. E.; Hernandez, P. E.; Koffler, N. F.; Chen, S. C.

1978-01-01

The author has identified the following significant results. Single date LANDSAT CCTs were processed, by Image-100 to classify Pinus and Eucalyptus species and their age groups. The study area Mogi-Guagu was located in the humid subtropical climate zone of Sao Paulo. The study was divided into ten preliminary classes and featured selection algorithms were used to calculate Bhattacharyya distance between all possible pairs of these classes in the four available channels. Classes having B-distance values less than 1.30 were grouped in four classes: (1) class PE - P. elliottii, (2) class P0 - Pinus species other than P. elliotii, (3) class EY - Eucalyptus spp. under two years, and (4) class E0 - Eucalyptus spp. more than two years old. The percentages of correct classification ranged from 70.9% to 94.12%. Comparisons of acreage estimated from the Image-100 with ground truth data showed agreement. The Image-100 percent recognition values for the above four classes were 91.62%, 87.80%, 89.89%, and 103.30%, respectively.

Airborne EM survey in volcanoes : Application to a volcanic hazards assessment

NASA Astrophysics Data System (ADS)

Mogi, T.

2010-12-01

Airborne electromagnetics (AEM) is a useful tool for investigating subsurface structures of volcanoes because it can survey large areas involving inaccessible areas. Disadvantages include lower accuracy and limited depth of investigation. AEM has been widely used in mineral exploration in frontier areas, and have been applying to engineering and environmental fields, particularly in studies involving active volcanoes. AEM systems typically comprise a transmitter and a receiver on an aircraft or in a towed bird, and although effective for surveying large areas, their penetration depth is limited because the distance between the transmitter and receiver is small and higher-frequency signals are used. To explore deeper structures using AEM, a semi-airborne system called GRounded Electrical source Airborne Transient ElectroMagnetics (GREATEM) has been developed. The system uses a grounded-electrical-dipole as the transmitter and generates horizontal electric fields. The GREATEM technology, first proposed by Mogi et al. (1998), has recently been improved and used in practical surveys (Mogi et al., 2009). The GREATEM survey system was developed to increase the depth of investigation possible using AEM. The method was tested in some volcanoes at 2004-2005. Here I will talk about some results of typical AEM surveys and GREATEM surveys in some volcanoes in Japan to mitigate hazards associated with volcano eruption. Geologic hazards caused by volcanic eruptions can be mitigated by a combination of prediction, preparedness and land-use control. Risk management depends on the identification of hazard zones and forecasting of eruptions. Hazard zoning involves the mapping of deposits which have formed during particular phases of volcanic activity and their extrapolation to identify the area which would be likely to suffer a similar hazard at some future time. The mapping is usually performed by surface geological surveys of volcanic deposits. Resistivity mapping by AEM is useful tool to identify each volcanic deposit on the surface and at shallower depth as well. This suggests that more efficient hazard map involving subsurface information can be supplied by AEM resistivity mapping.

First description of necrosis in leaves and pseudo-bulbs of Oncidium orchids caused by Burkholderia gladioli in São Paulo State, Brazil

USDA-ARS?s Scientific Manuscript database

A necrosis of orchid leaves and pseudobulbs was observed in a commercial orchid nursery in Mogi das Cruzes, Sao Paulo, Brazil. The symptoms were water-soaked, brown lesions that can develop into large areas of necrosis that extend throughout the entire plant, ultimately causing death. Bacteria were...

Trypanosomatids (Protozoa: Kinetoplastida) in three species of Armored Catfish from Mogi-Guaçu river, Pirassununga, São Paulo, Brazil.

PubMed

Molina, Julia Pereira; Madi, Rubens Riscala; Solferini, Vera Nisaka; Ceccarelli, Paulo Sérgio; Pinheiro, Hildete Prisco; Ueta, Marlene Tiduko

2016-06-07

Trypanosome infections have been reported in several species of fish, in majority of cases described on the basis of morphological characteristics. Trypanosomes in fish are heteroxenous and transmitted by hirudineans. This study aims to evaluate the prevalence and density of infections by Trypanosoma sp. in blood from three species of catfish, Hypostomus regani, H. strigaticeps, H. albopunctatus, from the Mogi Guaçu River, Pirassununga, São Paulo, Brazil. Further, this study intends to characterize the Trypanosoma specimens found in the blood of these fish by morphological and molecular techniques. The trypanosomes overall prevalence observed was 47.6% with a general average density of 0.75 parasites/µl of blood. Hypostomus regani and Hypostomus strigaticeps showed a significant difference in prevalence. The average densities of parasites were not significantly different among the three fish species. Similar findings were observed for the monthly variations in densities. The parasites found in the three species of catfish studied showed similar morphological characteristics. The morphological data and the statistical analyses used in this study didn't show the formation of groups. The analyses provided evidence of the presence of pleomorphisms in the trypanosomes found in the three studied fish.

Glacial isostatic stress shadowing by the Antarctic ice sheet

NASA Technical Reports Server (NTRS)

Ivins, E. R.; James, T. S.; Klemann, V.

2005-01-01

Numerous examples of fault slip that offset late Quaternary glacial deposits and bedrock polish support the idea that the glacial loading cycle causes earthquakes in the upper crust. A semianalytical scheme is presented for quantifying glacial and postglacial lithospheric fault reactivation using contemporary rock fracture prediction methods. It extends previous studies by considering differential Mogi-von Mises stresses, in addition to those resulting from a Coulomb analysis. The approach utilizes gravitational viscoelastodynamic theory and explores the relationships between ice mass history and regional seismicity and faulting in a segment of East Antarctica containing the great Antarctic Plate (Balleny Island) earthquake of 25 March 1998 (Mw 8.1). Predictions of the failure stress fields within the seismogenic crust are generated for differing assumptions about background stress orientation, mantle viscosity, lithospheric thickness, and possible late Holocene deglaciation for the D91 Antarctic ice sheet history. Similar stress fracture fields are predicted by Mogi-von Mises and Coulomb theory, thus validating previous rebound Coulomb analysis. A thick lithosphere, of the order of 150-240 km, augments stress shadowing by a late melting (middle-late Holocene) coastal East Antarctic ice complex and could cause present-day earthquakes many hundreds of kilometers seaward of the former Last Glacial Maximum grounding line.

Coleoptera associated with macrophytes of the genus Salvinia in four oxbow lakes in two river basins in southeast Brazil.

PubMed

Paula-Bueno, M C; Fonseca-Gessner, A A

2015-11-01

Macrophytes in oxbow lakes represent an important substrate for the Coleoptera. Two oxbow lakes the Rio Paranapanema were studied and the other two Rio Mogi-Guaçu, in the State de São Paulo, Brasil. In this study, there is greater similarity between the communities of Coleoptera of lakes greater connectivity with the main river channel or the difference in the species of Salvinia collected in the lakes studied interferes Coleoptera fauna that uses as substrate. A total of 9,222 specimens of Coleoptera were collected and identified in 10 families and 40 genera. The analysis MDS for abundance of Coleoptera showed the grouping of the oxbow lakes the Paranapanema River and a distancing the oxbow lakes the Mogi-Guaçu. The PERMANOVA test did not reveal any difference in the fauna between the wet and dry periods. It was concluded that the connectivity between river and lake is not decisive for the richness and abundance of aquatic fauna of Coleoptera. Therefore, the richness and abundance of aquatic Coleoptera associated vary with the species of Salvinia used as substrate.

InSAR Surface Deformation and Source Modelling at Semisopochnoi Island During the 2014 and 2015 Seismic Swarms with Constraints from Geochemical and Seismic Analysis

NASA Astrophysics Data System (ADS)

DeGrandpre, K.; Pesicek, J. D.; Lu, Z.

2017-12-01

During the summer of 2014 and the early spring of 2015 two notable increases in seismic activity at Semisopochnoi Island in the western Aleutian islands were recorded on AVO seismometers on Semisopochnoi and neighboring islands. These seismic swarms did not lead to an eruption. This study employs interferometric synthetic aperture radar (InSAR) techniques using TerraSAR-X images in conjunction with more accurately relocating the recorded seismic events through simultaneous inversion of event travel times and a three-dimensional velocity model using tomoDD. The InSAR images exhibit surprising coherence and an island wide spatial distribution of inflation that is then used in Mogi, Okada, spheroid, and ellipsoid source models in order to define the three-dimensional location and volume change required for a source at the volcano to produce the observed surface deformation. The tomoDD relocations provide a more accurate and realistic three-dimensional velocity model as well as a tighter clustering of events for both swarms that clearly outline a linear seismic void within the larger group of shallow (<10 km) seismicity. The source models are fit to this void and pressure estimates from geochemical analysis are used to verify the storage depth of magmas at Semisopochnoi. Comparisons of calculated source cavity, magma injection, and surface deformation volumes are made in order to assess the reality behind the various modelling estimates. Incorporating geochemical and seismic data to provide constraints on surface deformation source inversions provides an interdisciplinary approach that can be used to make more accurate interpretations of dynamic observations.

Tracking magma volume recovery at okmok volcano using GPS and an unscented kalman filter

USGS Publications Warehouse

Fournier, T.; Freymueller, Jeffrey T.; Cervelli, Peter

2009-01-01

Changes beneath a volcano can be observed through position changes in a GPS network, but distinguishing the source of site motion is not always straightforward. The records of continuous GPS sites provide a favorable data set for tracking magma migration. Dense campaign observations usually provide a better spatial picture of the overall deformation field, at the expense of an episodic temporal record. Combining these observations provides the best of both worlds. A Kalman filter provides a means for integrating discrete and continuous measurements and for interpreting subtle signals. The unscented Kalman filter (UKF) is a nonlinear method for time-dependent observations. We demonstrate the application of this technique to deformation data by applying it to GPS data collected at Okmok volcano. Seven years of GPS observations at Okmok are analyzed using a Mogi source model and the UKF. The deformation source at Okmok is relatively stable at 2.5 km depth below sea level, located beneath the center of the caldera, which means the surface deformation is caused by changes in the strength of the source. During the 7 years of GPS observations more than 0.5 m of uplift has occurred, a majority of that during the time period January 2003 to July 2004. The total volume recovery at Okmok since the last eruption in 1997 is ??60-80%. The UKF allows us to solve simultaneously for the time-dependence of the source strength and for the location without a priori information about the source. ?? 2009 by the American Geophysical Union.

Source Models of the June 17th, 2007 Kilauea Intrusion: Monte Carlo Optimization

NASA Astrophysics Data System (ADS)

Sinnett, D. K.; Montgomery-Brown, E. D.; Segall, P.; Miklius, A.; Poland, M.; Yun, S.; Zebker, H.

2007-12-01

Father's Day, 17 June 2007, marked the beginning of the 56th episode of the ongoing eruption of Kilauea volcano, Hawaii. The episode culminated in a short-lived eruption approximately 6 km west of Pu\\`{}u \\`{}O\\`{}o and 13 km southeast of Kilauea summit. The interruption of magma supply to, and withdrawal from, the reservoir beneath Pu\\`{}u \\`{}O\\`{}o caused cessation of activity and ~100 m of crater floor subsidence there. The continuous and campaign GPS, electronic tiltmeter, and seismic networks, as well as InSAR captured the episode in fine detail. Visual inspection of the data show subsidence at Kilauea summit and Pu\\`{}u \\`{}O\\`{}o, which fed the inflating dike. We began by modeling the intrusion with a Mogi source beneath Kilauea summit and a dislocation with uniform opening beneath the east rift zone embedded in an isotropic, homogenous, elastic, half space. We invert for the 12 source parameters (length, width, depth, dip, strike, horizontal position, and opening of the dike, and position, depth, and volume change of the Mogi source) using Monte Carlo optimization. The inversion used three component displacement data from 23 continuous and campaign GPS stations, diurnally and tidally filtered tilt from 6 stations, and an ENVISAT InSAR interferogram spanning 04/12/07 to 06/21/07 decimated using a quadtree algorithm. The optimum model included ~-4.1 * 106 m3 of volume loss from a reservoir 3 km beneath the summit, and a total dike volume of ~19*106 m3 (~4.84 km length x 2.45 km width x 1.6 m opening at 2.4 km depth). The discrepancy between summit volume loss and total dike volume suggests that other sources must have fed the dike. A crude estimate of volume loss from Pu\\`{}u \\`{}O\\`{}o is 8.5*106 m3 accounting for ~ 66% of the volume of the dike. The eruption site lies inside the eastern edge of the model, and ~0.5 km to the south of the best fit dike top. The best fit dike top parallels the northern margin of an area of ground cracking near Makaopuhui and terminates at its western margin near Mauna Ulu. The western termination is ~2.5 km east of the westernmost observed ground cracks. Within 95% bounds the dike top may intersect the eruption area and extend to all regions of ground cracking. It is also interesting to note that this dike is located in an area between the 1997 and 1999 intrusions. The best fit single dislocation model explains only 35% of the variance in the data. This is in part due to the inadequacies of a single planar dike with uniform opening to explain surface deformation and perhaps to inelastic deformation associated with ground cracking near the western edge of the dike. Models with distributed opening, in which the dike plane honors the optimization results as well as the region of decorrelation in the ENVISAT interferogram, explain 69% of the data (Montgomery-Brown et al., this session).

The Mohr-Coulomb criterion for intact rock strength and friction - a re-evaluation and consideration of failure under polyaxial stresses

NASA Astrophysics Data System (ADS)

Hackston, A.; Rutter, E.

2015-12-01

Abstract Darley Dale and Pennant sandstones were tested under conditions of both axisymmetric shortening and extension normal to bedding. These are the two extremes of loading under polyaxial stress conditions. Failure under generalized stress conditions can be predicted from the Mohr-Coulomb failure criterion under axisymmetric compression conditions provided the best form of polyaxial failure criterion is known. The sandstone data are best reconciled using the Mogi (1967) empirical criterion. Fault plane orientations produced vary greatly with respect to the maximum compression direction in the two loading configurations. The normals to the Mohr-Coulomb failure envelopes do not predict the orientations of the fault planes eventually produced. Frictional sliding on variously inclined sawcuts and failure surfaces produced in intact rock samples was also investigated. Friction coefficient is not affected by fault plane orientation in a given loading configuration, but friction coefficients in extension were systematically lower than in compression for both rock types and could be reconciled by a variant on the Mogi (1967) failure criterion. Friction data for these and other porous sandstones accord well with the Byerlee (1977) generalization about rock friction being largely independent of rock type. For engineering and geodynamic modelling purposes, the stress-state dependent friction coefficient should be used for sandstones, but it is not known to what extent this might apply to other rock types.

A new software for deformation source optimization, the Bayesian Earthquake Analysis Tool (BEAT)

NASA Astrophysics Data System (ADS)

Vasyura-Bathke, H.; Dutta, R.; Jonsson, S.; Mai, P. M.

2017-12-01

Modern studies of crustal deformation and the related source estimation, including magmatic and tectonic sources, increasingly use non-linear optimization strategies to estimate geometric and/or kinematic source parameters and often consider both jointly, geodetic and seismic data. Bayesian inference is increasingly being used for estimating posterior distributions of deformation source model parameters, given measured/estimated/assumed data and model uncertainties. For instance, some studies consider uncertainties of a layered medium and propagate these into source parameter uncertainties, while others use informative priors to reduce the model parameter space. In addition, innovative sampling algorithms have been developed to efficiently explore the high-dimensional parameter spaces. Compared to earlier studies, these improvements have resulted in overall more robust source model parameter estimates that include uncertainties. However, the computational burden of these methods is high and estimation codes are rarely made available along with the published results. Even if the codes are accessible, it is usually challenging to assemble them into a single optimization framework as they are typically coded in different programing languages. Therefore, further progress and future applications of these methods/codes are hampered, while reproducibility and validation of results has become essentially impossible. In the spirit of providing open-access and modular codes to facilitate progress and reproducible research in deformation source estimations, we undertook the effort of developing BEAT, a python package that comprises all the above-mentioned features in one single programing environment. The package builds on the pyrocko seismological toolbox (www.pyrocko.org), and uses the pymc3 module for Bayesian statistical model fitting. BEAT is an open-source package (https://github.com/hvasbath/beat), and we encourage and solicit contributions to the project. Here, we present our strategy for developing BEAT and show application examples; especially the effect of including the model prediction uncertainty of the velocity model in following source optimizations: full moment tensor, Mogi source, moderate strike-slip earth-quake.

Molecular Phylogenetics of Aedes japonicus, a Disease Vector That Recently Invaded Western Europe, North America, and the Hawaiian Islands

DTIC Science & Technology

2010-07-01

the scourge of dengue fever in Central and South America , if not in North America (Gratz 2004, Paupy et al. 2009) , and has become the primary...North America , and the Hawaiian Islands EMILIE C. CAMERON,1 RICHARD C. WILKERSON,2 MOTOYOSHI MOGI,3 ICHIRO MIYAGI,4 TAKAKO TOMA,4 HEUNG-CHUL KIM,5 AND...japonicus The genus Aedes (Diptera: Culicidae) includes the principal vectors of yellow fever, dengue , and aperi- odic lymphatic filariasis (Foster

Continuous deflation and plate spreading at the Askja volcanic system, Iceland: Constrains on deformation processes from finite element models using temperature-dependent non-linear rheology

NASA Astrophysics Data System (ADS)

Tariqul Islam, Md.; Sturkell, Erik; Sigmundsson, Freysteinn; Drouin, Vincent Jean Paul B.; Ófeigsson, Benedikt G.

2014-05-01

Iceland is located on the mid Atlantic ridge, where the spreading rate is nearly 2 cm/yr. The high rate of magmatism in Iceland is caused by the interaction between the Iceland hotspot and the divergent mid-Atlantic plate boundary. Iceland hosts about 35 volcanoes or volcanic systems that are active. Most of these are aliened along the plate boundary. The best studied magma chamber of central volcanoes (e.g., Askja, Krafla, Grimsvötn, Katla) have verified (suggested) a shallow magma chamber (< 5 km), which has been model successfully with a Mogi source, using elastic and/or elastic-viscoelastic half-space. Maxwell and Newtonian viscosity is mainly considered for viscoelastic half-space. Therefore, rheology may be oversimplified. Our attempt is to study deformation of the Askja volcano together with plate spreading in Iceland using temperature-dependent non-linear rheology. It offers continuous variation of rheology, laterally and vertically from rift axis and surface. To implement it, we consider thermo-mechanic coupling models where rheology follows dislocation flow in dry condition based on a temperature distribution. Continuous deflation of the Askja volcanic system is associated with solidification of magma in the magma chamber and post eruption relaxation. A long time series of levelling data show its subsidence trend to exponentially. In our preliminary models, a magma chamber at 2.8 km depth with 0.5 km radius is introduced at the ridge axis as a Mogi source. Simultaneously far field of rift axis stretching by 18.4 mm/yr (measured during 2007 to 20013) is applied to reproduce plate spreading. Predicted surface deformation caused of combined effect of tectonic-volcanic activities is evaluated with GPS during 2003-2009 and RADARSAT InSAR data during 2000 to 2010. During 2003-2009, data from the GPS site OLAF (close to the centre of subsidence) shows average rate of subsidence 19±1 mm/yr relative to the ITRF2005 reference frame. The MASK (Mid ASKJA) site is another GPS station at the top of predicted centre of magma chamber correlates well with OLAF site at 500 m distance from MASK. Average subsidence rates derived from GPS measurements show comparable rate derived from InSAR data. Velocities derived from InSAR show that the yearly maximum subsidence rates in the Askja caldera decrease linearly. The optimized pressure decrease in the magma chamber from the model follows an exponential decay, with P (MPa) = 2.0177 EXP(-0.0176x), where x is the numbers of years (1,2,3 .. 10). However total ramp pressure drop during this period (10 years) is 4 MPa and additional 4.68 MPa pressure drop may be caused of rheological relaxation.

Comparison between two thoracotomy closure techniques: postoperative pain and pulmonary function*

PubMed Central

Leandro, Juliana Duarte; Rodrigues, Olavo Ribeiro; Slaets, Annie France Frere; Schmidt, Aurelino F.; Yaekashi, Milton L.

2014-01-01

OBJECTIVE: To compare two thoracotomy closure techniques (pericostal and transcostal suture) in terms of postoperative pain and pulmonary function. METHODS: This was a prospective, randomized, double-blind study carried out in the Department of Thoracic Surgery of the Luzia de Pinho Melo Hospital das Clínicas and at the University of Mogi das Cruzes, both located in the city of Mogi das Cruzes, Brazil. We included 30 patients (18-75 years of age) undergoing posterolateral or anterolateral thoracotomy. The patients were randomized into two groups by the type of thoracotomy closure: pericostal suture (PS; n = 16) and transcostal suture (TS; n = 14). Pain intensity during the immediate and late postoperative periods was assessed by a visual analogic scale and the McGill Pain Questionnaire. Spirometry variables (FEV1, FVC, FEV1/FVC ratio, and PEF) were determined in the preoperative period and on postoperative days 21 and 60. RESULTS: Pain intensity was significantly greater in the PS group than in the TS group. Between the preoperative and postoperative periods, there were decreases in the spirometry variables studied. Those decreases were significant in the PS group but not in the TS group. CONCLUSIONS: The patients in the TS group experienced less immediate and late post-thoracotomy pain than did those in the PS group, as well as showing smaller reductions in the spirometry parameters. Therefore, transcostal suture is recommended over pericostal suture as the thoracotomy closure technique of choice. PMID:25210961

Surface Deformation and Source Model at Semisopochnoi Volcano from InSAR and Seismic Analysis During the 2014 and 2015 Seismic Swarms

NASA Astrophysics Data System (ADS)

DeGrandpre, K.; Pesicek, J. D.; Lu, Z.

2016-12-01

During the summer of 2014 and the early spring of 2015 two notable increases in seismic activity at Semisopochnoi volcano in the western Aleutian islands were recorded on AVO seismometers on Semisopochnoi and neighboring islands. These seismic swarms did not lead to an eruption. This study employs differential SAR techniques using TerraSAR-X images in conjunction with more accurately relocating the recorded seismic events through simultaneous inversion of event travel times and a three-dimensional velocity model using tomoDD. The interferograms created from the SAR images exhibit surprising coherence and an island wide spatial distribution of inflation that is then used in a Mogi model in order to define the three-dimensional location and volume change required for a source at Semisopochnoi to produce the observed surface deformation. The tomoDD relocations provide a more accurate and realistic three-dimensional velocity model as well as a tighter clustering of events for both swarms that clearly outline a linear seismic void within the larger group of shallow (<10 km) seismicity. While no direct conclusions as to the relationship of these seismic events and the observed surface deformation can be made at this time, these techniques are both complimentary and efficient forms of remotely monitoring volcanic activity that provide much deeper insights into the processes involved without having to risk hazardous or costly field work.

Modeling of February 1993 Intrusion Seen by JERS-1 Satellite, Kilauea Volcano, Hawaii

NASA Astrophysics Data System (ADS)

Moore, S.; Wauthier, C.; Fukushima, Y.; Poland, M. P.

2016-12-01

Interferometric Synthetic Aperture Radar (InSAR) is a valuable means of remotely assessing deformation on the surface of the earth. At Kilauea Volcano, Hawai'i many InSAR deformation maps (interferograms) have been studied in recent years to monitor deformation on the volcano. In February 1993, a diking event occurred that could be one of the first intrusions seen by InSAR satellites at Kilauea. This event has not received much attention due to little geodetic data spanning the event. Between October 1992 and March 1993, SAR images from the JERS-1 satellite captured 30 centimeters of surface deformation occurring along the East Rift Zone (ERZ) near Makaopuhi crater. Seismic activity was similar to other intrusions with more than 5,000 shallow (<5 km) earthquakes occurred in the area between the summit caldera and Makaopuhi crater from February 7-9, 1993 [Okubo & Nakata, 2003]. We used simple analytical half-space solutions (e.g., Mogi [1958], Okada [1992)]), as well as a more complex and mechanically robust numerical approach (3D-MBEM [Cayol and Cornet, 1997]) to model deformation sources active between October 1992 and March 1993. Non-linear inversions of the JERS-1 Interferogram show that the most likely source to account for the February 1993 observed deformation is a subvertical rectangular dike with an opening of 1.5 m reaching depths of 1.5 to 3 km.

Seasonal variations in water quality of an oxbow lake in response to multiple short-time pulses of flooding (Jataí Ecological Station--Mogi-Guaçu River, Luiz Antonio, SP-Brazil).

PubMed

Krusche, A V; Mozeto, A A

1999-01-01

Mogi-Guaçu River is a six-order floodplain river in the upper Paraná River Basin, Southern Brazil. Its yearly discharge varies from a minimum of 100 m3.s-1 to a maximum of 600 m3.s-1. Diogo Lake is a shallow lake located at its floodplain within the Jataí Ecological Station (Luiz Antonio, São Paulo State) and is connected throughout the year to the river through a narrow and shallow channel. The main finding of this study is that the river hidrology controls the annual variations in lake hydrochemistry through a series of hydraulic effects related to oscillations in river discharge. Lake water quality is a resultant of differential contribution from local and regional watersheds. During the low water period, lake water quality is determined by inputs from Cafundó Creek, which drains the local watershed into the lake. Raising the river level during the rain season results in the damming of lake and culminates with the entrance of river waters into the plain. The geochemistry of waters in this system is determined by weathering of sandstones with basalt intrusions. Waters are acidic (river pH = 6.00 to 7.02 and stream-lake pH = 5.15 to 6.7) and dominant cations are Na+ and K+. Major anions are almost exclusively represented by bicarbonate and an unknown concentration of organic acid anions. The overall ionic load of these soft waters in the system is therefore very low.

Assessment of indoor climate of Mogiła Abbey in Kraków (Poland) and the application of the analogues method to predict microclimate indoor conditions.

PubMed

Frasca, F; Siani, A M; Casale, G R; Pedone, M; Bratasz, Ł; Strojecki, M; Mleczkowska, A

2017-06-01

The microclimatic monitoring of the historic church of Mogiła Abbey (Kraków, Poland) was carried out to study the impact of the environmental parameters on the organic and hygroscopic artworks. Specific indexes were proposed to objectively assess the quality of time series of temperature (T), relative humidity (RH), and carbon dioxide (CO 2 ) before applying the exploratory data analysis. The series were used to define the historic environmental conditions as stated in the European Standard EN 15757:2010 and with the use of the climate evaluation chart (CEC). It was found that the percentage of time in which T and RH values are within the allowable limits of the ASHRAE (2011) Class B is more than 85 %. This means that, for about 15 % of the time, there is a high risk of mechanical damage to highly vulnerable objects mainly due to the RH variability. The environment at the chancel resulted moister than that at the cornice, and the fungal growth is possible. In addition, the time-weighted preservation index (TWPI) is computed to evaluate the life expectancy of the objects, taking into account the environmental conditions of the site under study. The method of analogues, developed to predict the evolution of a system given observations of the past and without the knowledge of any equation among variables, was proposed and applied to the time series of temperature, relative humidity, and carbon dioxide with a 1-h sampling time to avoid the influence of the autocorrelation.

Near real-time monitoring of volcanic surface deformation from GPS measurements at Long Valley Caldera, California

USGS Publications Warehouse

Ji, Kang Hyeun; Herring, Thomas A.; Llenos, Andrea L.

2013-01-01

Long Valley Caldera in eastern California is an active volcanic area and has shown continued unrest in the last three decades. We have monitored surface deformation from Global Positioning System (GPS) data by using a projection method that we call Targeted Projection Operator (TPO). TPO projects residual time series with secular rates and periodic terms removed onto a predefined spatial pattern. We used the 2009–2010 slow deflation as a target spatial pattern. The resulting TPO time series shows a detailed deformation history including the 2007–2009 inflation, the 2009–2010 deflation, and a recent inflation that started in late-2011 and is continuing at the present time (November 2012). The recent inflation event is about four times faster than the previous 2007–2009 event. A Mogi source of the recent event is located beneath the resurgent dome at about 6.6 km depth at a rate of 0.009 km3/yr volume change. TPO is simple and fast and can provide a near real-time continuous monitoring tool without directly looking at all the data from many GPS sites in this potentially eruptive volcanic system.

Rapid Inflation Caused by Shallow Magmatic Activities at Okmok Volcano, Alaska, Detected by GPS Campaigns 2000-2003

NASA Astrophysics Data System (ADS)

Miyagi, Y.; Freymueller, J.; Kimata, F.; Sato, T.; Mann, D.

2006-12-01

Okmok volcano is located on Umnak Island in the Aleutian Arc, Alaska. This volcano consists of a large caldera, and there are several post-caldera cones within the caldera. It has erupted more than 10 times during the last century, with the latest eruption occurring in February 1997. Annual GPS campaigns during 2000-2003 have revealed a rapid inflation at Okmok volcano. Surface deformation indicates that Okmok volcano has been inflating during 2000-2003 at a variable inflation rate. Total displacements over three years are as large as 15 cm of maximum radial displacement and more than 35 cm of maximum uplift. Simple inflation pattern after 2001, showing radial outward displacements from the caldera center and significant uplifts, are modeled by a Mogi inflation source, which is located at the depth of about 3.1 km beneath the geometric center of the caldera, and we interpreted the source as a shallow magma chamber. The results from our GPS measurements correspond approximately to the results from InSAR measurement for almost same periods, except for an underestimate of the volume change rate of the source deduced by InSAR data for the period 2002-2003. Taking into consideration the results from InSAR measurements, the amount of volume increase in the source is estimated to be about 0.028 km3 during 1997-2003. This means that 20-54 percent of the volume erupted in the 1997 eruption has been already replenished in the shallow magma chamber. An eruption recurrence time is estimated from the volume change rate of the source to be about 15-30 years for 1997-sized eruptions, which is consistent with about 25 years average time interval between major eruptions at Okmok volcano. An additional modeling using a rectangular tensile source combined to the main spherical source suggests a possibility of other magma storage located between the main source and the active vent, which is associated with lateral magma transportation between them. The combined model improved residuals compared to those from single-source model, and provided significantly better fitting to the deformation data inside the caldera.

Tilt recorded by a portable broadband seismograph: The 2003 eruption of Anatahan Volcano, Mariana Islands

USGS Publications Warehouse

Wiens, D.A.; Pozgay, S.H.; Shore, P.J.; Sauter, A.W.; White, R.A.

2005-01-01

The horizontal components of broadband seismographs are highly sensitive to tilt, suggesting that commonly deployed portable broadband seismic sensors may record important tilt information associated with volcanic eruptions. We report on a tilt episode that coincides with the first historical eruption of Anatahan volcano on May 10, 2003. The tilt was recorded by a Strekheisen STS-2 seismograph deployed in an underground insulated chamber 7 km west of the active vent. An ultra-long period signal with a dominant period of several hours was recorded on the E-W component beginning at 06:20 GMT on May 10, which coincides with the onset of continuous volcano-tectonic (VT) seismicity and is one hour prior to the eruption time estimated by the Volcanic Ash Advisory Center. The signal is much smaller on the N-S component and absent on the vertical component, suggesting it results from tilt that is approximately radial with respect to the active vent. An estimate of tilt as a function of time is recovered by deconvolving the record to acceleration and dividing by the acceleration of gravity. The record indicates an initial episode of tilt downward away from the volcanic center from 06:20-09:30 GMT, which we interpret as inflation of the shallow volcanic source. The tilt reverses, recording deflation, from 09:30 until 17:50, after which the tilt signal becomes insignificant. The inflation corresponds to a period of numerous VT events, whereas fewer events were recorded during the deflation episode, and the VT events subsequently resumed after the end of the deflationary tilt. The maximum tilt of 2 microradians can be used to estimate the volume of the source inflation (???2 million in m3), assuming a simple Mogi source model. These calculations are consistent with other estimates of source volume if reasonable source depths are assumed. Examination of broadband records of other eruptions may disclose further previously unrecognized tilt signals. Copyright 2005 by the American Geophysical Union.

Aquatic insect community structure under the influence of small dams in a stream of the Mogi-Guaçu river basin, state of São Paulo.

PubMed

Saulino, H H L; Corbi, J J; Trivinho-Strixino, S

2014-02-01

The fragmentation of lotic systems caused by construction of dams has modified many aquatic communities. The objective of this study was to analyse changes in the aquatic insect community structure by discontinuity of habitat created by dams along the Ribeirão das Anhumas, a sub-basin of the Mogi-Guaçu River (state of São Paulo, Brazil). Entomofauna collection was carried out in 10 segments upstream and downstream of five dams along the longitudinal profile of the stream, with a quick sampling method using a D net (mesh 250 mm) with 2 minutes of sampling effort. The insects were sorted and identified to the lowest possible taxonomic level and analysed by the Shannon diversity index, β diversity, richness estimated by rarefaction curves and relative participation of functional feeding groups. The results showed a slight reduction in diversity in the downstream segments, as well as along the longitudinal profile of the stream. However, there were no significant differences in abundance and richness between the upstream and downstream segments, indicating that the dams did not influence these variables. Differences were observed in the functional feeding groups along the longitudinal profile. Predator and gatherer insects were dominant in all segments analysed. The feeding group of shredders was more abundant in the segment DSIII with the participation of Marilia Müller (Odontoceridae - Trichoptera), although we observed a decrease of shredders and scrapers with the decrease of the canopy cover reducing values of β diversity in the continuum of Ribeirão das Anhumas. This result demonstrated the importance of the conservation of the riparian vegetation in order to maintain the integrity of the stream.

Time dependence of volcano inflation: mass influx or viscoelastic relaxation? Insights from Grímsvötn volcano, Iceland

NASA Astrophysics Data System (ADS)

Segall, P.

2017-12-01

Distinguishing magma chamber pressurization from relaxation of a viscoelastic aureole surrounding the chamber based on geodetic measurements has remained challenging. Elastic models with mass inflow proportional to the pressure difference between the chamber and a deep reservoir predict exponentially decaying flux. For a spherical chamber surrounded by a Maxwell viscoelastic shell with pressure dependent recharge, the surface deformation is the sum of two exponentials (Segall, 2016). GPS displacements following eruptions of Grímsvötn, Iceland in 2004 and 2011 exhibit rapid post-eruptive inflation (time scale of 0.1 yr), followed by inflation with a much longer time constant. Markov Chain Monte Carlo inversion with the viscoelastic model shows the GPS time series can be fit with viscosity of 2e16 Pa-s, and a relatively incompressible magma, B = beta_c/ (beta_m + beta_c) > 0.6, where beta_m and beta_c are chamber and magma compressibility. The latter appears to conflict with the ratio of erupted volume to geodetically inferred source volume change, rv 10, obtained for the best fitting spherical (Mogi ) source (Hreinsdóttir, 2014). Since rv = 1/B, this implies a relatively compressible melt, B 0.1. Reexamination of the co-eruptive GPS and tilt data with the more general ellipsoidal model of Cervelli (2013), reveals that the best fitting sources are oblate (b/a 3), deeper, and with larger volume changes, rv 3, relative to spherical models. Oblate magma chambers are consistent with seismic tomography. FEM calculations including free surface effects lead to even larger co-eruptive volume changes, smaller rv and hence larger B. I conclude that the data are consistent with rapid post-eruptive inflation driven by viscoelastic relaxation with a relatively incompressible magma, although other interpretations will be discussed.

Volcanic deformation sources associated with Fogo 2011-2012 unrest, Azores - The first modelling result

NASA Astrophysics Data System (ADS)

Okada, Jun; Araújo, João; Bonforte, Alessandro; Guglielmino, Francesco; Lorenzo, Maria; Ferreira, Teresa

2016-04-01

Volcanic deformation is often observed at many active volcanoes in the world by using space geodesy techniques, namely GNSS and InSAR. More difficulties in judgement if eruptions are imminent or not arise when such phenomenon occurs at dormant volcanoes due to the lack of eruption experiences with monitoring data. The eruption triggering mechanism is still controversial at many cases, but many attempts to image deformation sources beneath volcanoes have been made using geophysical inversion techniques. In this study, we show the case study of Fogo (Água de Pau) volcano, S. Miguel Island, Azores which represents over 450 years of eruption dormancy since 1563-1564. In the recent decades Fogo has exhibited three prominent unrest episodes (1989, 2003-2006, and 2011-2012). The lack of geochemical and hydrothermal evidences for a magmatic intrusion during those episodes does not encourage discussions on resuming volcanic activity of Fogo. However, the inflation/uplift are evident on the edifices at least for the last two unrest episodes based on GPS data by Trota et al. (2009) and Okada et al. (2015), respectively. The preliminary deformation modelling based on repeated GPS campaign data suggested a shallow expanding spheroid (Trota et al. 2009) or a single Mogi sources beneath the summit caldera. We performed a more integrated inversion for the 2011-2012 episode using a genetic algorithm optimizing the source parameters. The best fit model agrees well with the regional/local tectonic lineament suggesting the close relation between the volcanic sources and the regional/local tectonics. The regional extensional stress (between Eurasia and Nubia plates) may play important roles for the ascent of volcanic fluids at Fogo volcano. We do not discard the possibility that Fogo may have been preparing for eruptions by intermittent ascents of magma at shallow crust (i.e. experiencing "failed eruptions") during the apparent dormant period. As a local monitoring agency, CIVISA (Center for Information and Seismovolcanic Surveillance of the Azores) continues to monitor Fogo's deformation in order to track changes in the source processes (source position and geometry, volume, pressure, etc.) as well as Fogo's seismicity and geochemistry.

Ground surface deformation patterns, magma supply, and magma storage at Okmok volcano, Alaska, from InSAR analysis: 2. Coeruptive deflation, July-August 2008

USGS Publications Warehouse

Lu, Zhong; Dzurisin, Daniel

2010-01-01

A hydrovolcanic eruption near Cone D on the floor of Okmok caldera, Alaska, began on 12 July 2008 and continued until late August 2008. The eruption was preceded by inflation of a magma reservoir located beneath the center of the caldera and ∼3 km below sea level (bsl), which began immediately after Okmok's previous eruption in 1997. In this paper we use data from several radar satellites and advanced interferometric synthetic aperture radar (InSAR) techniques to produce a suite of 2008 coeruption deformation maps. Most of the surface deformation that occurred during the eruption is explained by deflation of a Mogi-type source located beneath the center of the caldera and 2–3 km bsl, i.e., essentially the same source that inflated prior to the eruption. During the eruption the reservoir deflated at a rate that decreased exponentially with time with a 1/e time constant of ∼13 days. We envision a sponge-like network of interconnected fractures and melt bodies that in aggregate constitute a complex magma storage zone beneath Okmok caldera. The rate at which the reservoir deflates during an eruption may be controlled by the diminishing pressure difference between the reservoir and surface. A similar mechanism might explain the tendency for reservoir inflation to slow as an eruption approaches until the pressure difference between a deep magma production zone and the reservoir is great enough to drive an intrusion or eruption along the caldera ring-fracture system.

Volcanoes Behave as Composite Materials: Implications for Modeling Magma Chambers, Dikes, and Surface Deformation

NASA Astrophysics Data System (ADS)

Leiss, B.; Gudmundsson, A.; Philipp, S. L.

2005-12-01

By definition, composite volcanoes are composed of numerous alternating material units or layers such as lavas, sediments, and pyroclastics. Commonly, these layers have widely different mechanical properties. In particular, some lava flows and welded pyroclastic flows may be stiff (with a high Young's modulus), whereas others, such as non-welded pyroclastic units and sediments, may be soft (with a low Young's modulus). As a consequence, even if the loading (tectonic stress, magmatic pressure, or displacement) is uniform, the stresses within the composite volcano will vary widely. In this sense, the behavior of composite volcanoes is similar to that of general composite materials. The deformation of the surface of a volcano during an unrest period results from stresses generated by processes and parameters such as fluid pressure in a geothermal field or a magma chamber, a regional tectonic event, and a dike injection. Here we present new numerical models on mechanics of magma chambers and dikes, and the associated surface deformation of composite volcanoes. The models show that the surface deformation during magma-chamber inflation and deflation depends much on the chamber geometry, the loading conditions, and the mechanical properties of the rock units that constitute the volcano. The models also indicate that the surface deformation induced by a propagating dike depends much on the mechanical properties of the layers between the dike tip and the surface. In particular, the numerical results show that soft layers and weak contacts between layers may suppress the dike-induced tensile stresses and the associated surface deformation. Many dikes may therefore become injected and arrested at shallow depths in a volcano while giving rise to little or no surface deformation. Traditional analytical surface-deformation models such as a point source (Mogi model) for a magma-chamber pressure change and a dislocation for a dike normally assume the volcano to behave as a homogeneous, isotropic half space. The present numerical results, combined with field studies, indicate that such analytical models may yield results that have little similarity with the actual structure being modeled.

Modelling the risk of mortality of Corbicula fluminea (Müller, 1774) (Bivalvia: Corbiculidae) exposed to different turbidity conditions.

PubMed

Avelar, W E P; Neves, F F; Lavrador, M A S

2014-05-01

The provision of sediment in rivers, due to erosion processes that occur in the environment, consists of a major source of pollution and alteration of the physicochemical conditions of water resources. In addition, the increase in water turbidity may cause siltation, dramatically impacting aquatic communities. Specifically considering the bivalve Corbicula fluminea (Müller, 1774), the aim of this study was to analyse the effect of exposure to different turbidity conditions of sediments, as a risk factor for the animals. For this purpose, a docking device was designed to ensure water circulation in a closed system and to maintain the desired levels of turbidity. Although C. fluminea can generally tolerate environmental changes in aquatic systems, an intolerance to high turbidity levels was experimentally observed, expressed by the mortality rate of the animals when exposed to conditions above 150 nephelometric turbidity units (NTU). This value was similar to the one recorded at study sites in the rivers Pardo (Serrana-SP-Brazil) and Mogi Guaçu (Porto Ferreira-SP-Brazil) during the rainy season. Using a logistic regression model, the experimental results were analysed and the observed mortality rates indicate that the exposure of the animals to turbidity levels above 150 nephelometric turbidity units (NTU), for periods longer than 120 hours, may be considered a probable cause of mortality for the species.

Measurement and interpretation of subtle deformation signals at Unimak Island from 2003 to 2010 using weather model-assisted time series InSAR

NASA Astrophysics Data System (ADS)

Gong, W.; Meyer, F. J.; Lee, C.-W.; Lu, Z.; Freymueller, J.

2015-02-01

A 7 year time series of satellite radar images over Unimak Island, Alaska—site of Westdahl Volcano, Fisher Caldera, and Shishaldin Volcano—was processed using a model-free Persistent Scatterer Interferometry technique assisted by numerical weather prediction model. The deformation-only signals were optimally extracted from atmosphere-contaminated phase records. The reconstructed deformation time series maps are compared with campaign and continuous Global Positioning System (GPS) measurements as well as Small Baseline Subset interferometric synthetic aperture radar (InSAR) results for quality assessment and geophysical interpretation. We observed subtle surface inflation at Westdahl Volcano that can be fit by a Mogi source located at approximately 3.6 km north of Westdahl peak and at depth of about 6.9 km that is consistent with the GPS-estimated depth for the 1998 to 2001 time period. The magma chamber volume change decays during the period of 2003 to 2010. The deformation field over Fisher Caldera is steadily subsiding over time. Its best fit analytical model is a sill source that is about 7.9 km in length, 0.54 km in width, and located at about 5.5 km below sea level underneath the center of Fisher Caldera with strike angle of N52°E. Very little deformation was detected near Shishaldin peak; however, a region approximately 15 km east of Shishaldin, as well as an area at the Tugamak range at about 30 km northwest of Shishaldin, shows evidence for movement toward the satellite, with a temporal signature correlated with the 2004 Shishaldin eruption. The cause of these movements is unknown.

Location and source characteristics of the 2016 January 6 North Korean nuclear test constrained by InSAR

NASA Astrophysics Data System (ADS)

Wei, Meng

2017-05-01

The interferometric synthetic aperture radar (InSAR) data from the Japan Aerospace Exploration Agency ALOS-2 satellite show possible deformation associated with the 2016 January 6 North Korean nuclear test whereas the European Space Agency Sentinel-1A data are decorrelated. This is the first time that deformation related to a nuclear test has been measured since 1992. Here, I present two interpretations of the observed deformation: First, the deformation can be explained by a triggered landslide on the western slope of Mt Mantap, with a displacement of up to 10 cm across a patch of 1 km2. Second, the observation may be from uplift created by the nuclear explosion. In the second interpretation, the location, depth and cavity size can be estimated from a topography-corrected homogenous half-space model (Mogi). The preferred location of the 2016 January 6 event is 41.2993°N 129.0715°E, with an uncertainty of 100 m. The estimated depth is 420-700 m and the cavity radius is 23-27 m. Based on empirical data and the assumption of granite as the host rock, the yield is estimated to be 11.6-24.4 kilotons of TNT, which is consistent with previous results based on seismic data. With these two interpretations, I demonstrate that InSAR data provide an independent tool to locate and estimate source characteristics of nuclear tests in North Korea. The ambiguity of interpretation is mainly due to the limited InSAR data acquisition. Future frequent data collection by current and upcoming InSAR satellites will allow full use of InSAR for nuclear monitoring and characterization in North Korea and around the world.

Creep, dike intrusion, and magma chamber deflation model for the 2000 Miyake eruption and the Izu islands earthquakes

NASA Astrophysics Data System (ADS)

Ozawa, S.; Miyazaki, S.; Nishimura, T.; Murakami, M.; Kaidzu, M.; Imakiire, T.; Ji, X.

2004-02-01

Analysis of Global Positioning System data shows shrinkage of Miyake Island and the widening between Nijima and Kozu Islands during the period of the Miyake island volcanic activity and the ensuing Izu islands earthquakes in 2000. The estimated time evolution of a model consisting of a dike, creeping faults, and a Mogi source suggests that a crack opening on Miyake Island occurred immediately after the start of the seismic activities on 26 June and ended within several days at the west coast of Miyake Island. After the seabed eruption on 27 June, magma migrated from Miyake Island to Kozu and Nijima Islands within several days. The estimated volume of intruded magma totals around 1.2 × 109 m3. Associated with the magma intrusion between Miyake and Kozu Islands, left-lateral and right-lateral creep motions occurred in regions off the west coast of Miyake Island and near Kozu Island. The accumulated moment energy is equivalent to an earthquake of Mw 6.6 and 6.6 for right-lateral and left-lateral creeping faults, respectively. The estimated magma chamber continued deflation beneath the southwestern part of Miyake Island from 26 June, totaling around 0.12 × 109 m3 in volume change, in addition to the collapse volume of 0.6 × 109 m3 at the summit of Mount Oyama on Miyake Island. The volume change on Miyake Island can be compensated by the migrated magma toward Kozu Island from the deflation source beneath Miyake Island. The deflation speed of the magma chamber beneath Miyake Island decreased and increased before and after the eruption of 14-15 July and 18 August, suggesting a change in balance of mass influx and draining out rate of the magma chamber.

RSEIS and RFOC: Seismic Analysis in R

NASA Astrophysics Data System (ADS)

Lees, J. M.

2015-12-01

Open software is essential for reproducible scientific exchange. R-packages provide a platform for development of seismological investigation software that can be properly documented and traced for data processing. A suite of R packages designed for a wide range of seismic analysis is currently available in the free software platform called R. R is a software platform based on the S-language developed at Bell Labs decades ago. Routines in R can be run as standalone function calls, or developed in object-oriented mode. R comes with a base set of routines, and thousands of user developed packages. The packages developed at UNC include subroutines and interactive codes for processing seismic data, analyzing geographic information (GIS) and inverting data involved in a variety of geophysical applications. On CRAN (Comprehensive R Archive Network, http://www.r-project.org/) currently available packages related to seismic analysis are RSEIS, Rquake, GEOmap, RFOC, zoeppritz, RTOMO, and geophys, Rwave, PEIP, hht, rFDSN. These include signal processing, data management, mapping, earthquake location, deconvolution, focal mechanisms, wavelet transforms, Hilbert-Huang Transforms, tomographic inversion, and Mogi deformation among other useful functionality. All software in R packages is required to have detailed documentation, making the exchange and modification of existing software easy. In this presentation, I will focus on packages RSEIS and RFOC, showing examples from a variety of seismic analyses. The R approach has similarities to the popular (and expensive) MATLAB platform, although R is open source and free to down load.

Magma-sponge hypothesis and stratovolcanoes: Case for a compressible reservoir and quasi-steady deep influx at Soufrière Hills Volcano, Montserrat

NASA Astrophysics Data System (ADS)

Voight, Barry; Widiwijayanti, Christina; Mattioli, Glen; Elsworth, Derek; Hidayat, Dannie; Strutt, M.

2010-02-01

We use well-documented time histories of episodic GPS surface deformation and efflux of compressible magma to resolve apparent magma budget anomalies at Soufrière Hills volcano (SHV) on Montserrat, WI. We focus on data from 2003 to 2007, for an inflation succeeded by an episode of eruption-plus-deflation. We examine Mogi-type and vertical prolate ellipsoidal chamber geometries to accommodate both mineralogical constraints indicating a relatively shallow pre-eruption storage, and geodetic constraints inferring a deeper mean-pressure source. An exsolved phase involving several gas species greatly increases andesite magma compressibility to depths >10 km (i.e., for water content >4 wt%, crystallinity ˜40%), and this property supports the concept that much of the magma transferred into or out of the crustal reservoir could be accommodated by compression or decompression of stored reservoir magma (i.e., the “magma-sponge”). Our results suggest quasi-steady deep, mainly mafic magma influx of the order of 2 m3s-1, and we conclude that magma released in eruptive episodes is approximately balanced by cumulative deep influx during the eruptive episode and the preceding inflation. Our magma-sponge model predicts that between 2003 and 2007 there was no evident depletion of magma reservoir volume at SHV, which comprises tens of km3 with radial dimensions of order ˜1-2 km, in turn implying a long-lived eruption.

Sources of granite magmatism in the Embu Terrane (Ribeira Belt, Brazil): Neoproterozoic crust recycling constrained by elemental and isotope (Sr-Nd-Pb) geochemistry

NASA Astrophysics Data System (ADS)

Alves, Adriana; Janasi, Valdecir de Assis; Campos Neto, Mario da Costa

2016-07-01

Whole rock elemental and Sr-Nd isotope geochemistry and in situ K-feldspar Pb isotope geochemistry were used to identify the sources involved in the genesis of Neoproterozoic granites from the Embu Terrane, Ribeira Belt, SE Brazil. Granite magmatism spanned over 200 Ma (810-580 Ma), and is dominated by crust-derived relatively low-T (850-750 °C, zircon saturation) biotite granites to biotite-muscovite granites. Two Cryogenian plutons show the least negative εNdt (-8 to -10) and highest mg# (30-40) of the whole set. Their compositions are strongly contrasted, implying distinct sources for the peraluminous (ASI ∼ 1.2) ∼660 Ma Serra do Quebra-Cangalha batholith (metasedimentary rocks from relatively young upper crust with high Rb/Sr and low Th/U) and the metaluminous (ASI = 0.96-1.00) ∼ 630 Ma Santa Catarina Granite. Although not typical, the geochemical signature of these granites may reflect a continental margin arc environment, and they could be products of a prolonged period of oceanic plate consumption started at ∼810 Ma. The predominant Ediacaran (595-580 Ma) plutons have a spread of compositions from biotite granites with SiO2 as low as ∼65% (e.g., Itapeti, Mauá, Sabaúna and Lagoinha granites) to fractionated muscovite granites (Mogi das Cruzes, Santa Branca and Guacuri granites; up to ∼75% SiO2). εNdT are characteristically negative (-12 to -18), with corresponding Nd TDM indicating sources with Paleoproterozoic mean crustal ages (2.0-2.5 Ga). The Guacuri and Santa Branca muscovite granites have the more negative εNdt, highest 87Sr/86Srt (0.714-0.717) and lowest 208Pb/206Pb and 207Pb/206Pb, consistent with an old metasedimentary source with low time-integrated Rb/Sr. However, a positive Nd-Sr isotope correlation is suggested by data from the other granites, and would be consistent with mixing between an older source predominant in the Mauá granite and a younger, high Rb/Sr source that is more abundant in the Lagoinha granite sample. The Ediacaran granites are coeval with profuse granite magmatism attributed to continental arc magmatism in northern Ribeira and Araçuaí belts. However, their evolved compositions with low mg# and dominantly peraluminous character are unlike those of magmatic arc granites, and they are more likely products of post-collisional magmatism or correspond to an inner belt of crust-derived granites.

Populational genetic structure of free-living maned wolves (Chrysocyon brachyurus) determined by proteic markers.

PubMed

De Mattos, P S R; Del Lama, M A; Toppa, R H; Schwantes, A R

2004-08-01

Electrophoretic analysis of presumptive twenty gene loci products was conducted in hemolisates and plasma samples of twenty-eight maned wolves (Chrysocyon brachyurus) from an area in northeastern São Paulo State, Brazil. The area sampled was divided into three sub-areas, with the Mogi-Guaçu and Pardo rivers regarded as barriers to the gene flow. The polymorphism degree and heterozygosity level (intralocus and average) estimated in this study were similar to those detected by other authors for maned wolves and other species of wild free-living canids. The samples of each sub-area and the total sample exhibited genotype frequencies consistent with the genetic equilibrium model. The values of the F-statistics evidenced absence of inbreeding and population subdivision and, consequently, low genetic distances were found among the samples of each area.

3D Deformation at the Coso Geothermal Field - Observations and Models

NASA Astrophysics Data System (ADS)

Hetland, E. A.; Hager, B. H.; McClusky, S.; King, R. W.

2001-12-01

Over the past decade, rapid ground deformation has been measured over the Coso geothermal field in Eastern CA using InSAR and GPS. InSAR resolves changes in distance along the line-of-sight (LOS) to the satellite with high spatial coverage. In the Coso geothermal field the maximum LOS displacements are up to 35 mm/yr. The inclination of the LOS is acute (about 20 degrees), hence the majority of the deformation resolved with InSAR is vertical, however LOS displacements are also affected by horizontal displacements. The ratio of the sensitivity of LOS displacements to vertical and horizontal displacements is at most 5 to 2, for horizontal displacements inline with the LOS. GPS is able to resolve large horizontal displacements in this area, leading to the conclusion that the InSAR LOS displacement fields are non-trivially affected by horizontal displacements. Additionally, since the horizontal displacements are large, GPS is also able to resolve vertical displacements. Moreover, the GPS three component velocities are fairly consistent with the LOS displacements from InSAR. This deformation has been largely attributed to subsidence as fluid is extracted from the geothermal reservoir. The reservoir has been previously modeled as deflating elliptical volumes and as collapsing sills. The elliptical volumes are described as Mogi sources, which are mathematically given as point forces along a line. The collapsing sills are treated as Okada dislocations for finite area faults with pure tensile displacements across them. In both of these dislocation models of the reservoir, the elastic moduli of the rock remains constant with changing fluid pressure. Actual reservoirs are more likely composed of regions of rock permeated with fluid-filled cracks and pores. In such a composite material, changing the pore-fluid pressure changes the elastic moduli of the region. These moduli changes cause the region to deform under loading, thus resulting in observed surface displacements. The surface displacements resulting from models with varying moduli of the reservoir rock are markedly different from patterns of surface displacements resulting from models in which the reservoir is treated as dislocations. For a given reservoir size, the differences in displacements from the various models are clearest in the horizontal displacement field, differing by up to a factor of two. We use finite element models with simple reservoir geometries to investigate the sensitivity of both vertical and horizontal displacements to the chosen reservoir model.

Seismological characteristics of the 2011 unrest in Santorini caldera: Implications for observed deformation and volcano-tectonics

NASA Astrophysics Data System (ADS)

Konstantinou, Konstantinos; Evangelidis, Christos; Melis, Nikolaos; Liang, Wen-Tzong

2013-04-01

Santorini caldera has experienced several explosive eruptions in the past, the most well-known of these being the Late Bronze Age (ca. 1628 BC) eruption that may have been responsible for the demise of the Minoan civilization. Since the early 1950's the volcano has been dormant without exhibiting any significant activity except from discharge of low-temperature hydrothermal fluids. In January 2011 both deformation and seismic activity increased considerably signaling a period of unrest which however, did not result in an eruption. One permanent and seven temporary seismic stations equipped with three-component sensors were deployed by the National Observatory of Athens. These were combined with seismic stations from the University of Thessaloniki, seven with only a vertical component and four with three-component sensors and all operated under the Hellenic Unified Seismic Network, thus densely monitoring the Santorini Volcano. These seismic stations have recorded the seismic activity from its start up to now. About 290 micro-earthquakes recorded by at least 5 stations were analyzed for the purpose of obtaining accurate epicentral and hypocentral locations using both catalog and differential travel times from waveform cross-correlation. All of these events exhibit clear P- and S-phases indicating that they resulted from shear failure of rock rather than fluid-flow within volcanic conduits. Results show two well-defined clusters in Palea and Nea Kameni islands within the caldera with hypocentral depths ranging between 5-10 km. Interestingly, one more cluster of events with depths between 15-19 km appears near the area of Cape Coloumbo and developed almost simultaneously with the clusters within the caldera. The Mogi source depth inferred from geodetic observations previously is shallower (~4 km) and does not coincide spatially with the clusters within the caldera. This points to the possibility that seismicity and deformation may be excited by deeper pressure changes. Shear wave splitting measurements have also been performed using all available waveform data in order to understand the nature and spatial variation of the stress field during the unrest. Fast polarization directions exhibit some orientations consistent with the regional NW-SE extension in the area, but also orientations along NE-SW that signify the presence of a local stress field as well.

Residual Gravity Changes at Kilauea: 1977-2003

NASA Astrophysics Data System (ADS)

Eggers, A. A.

2006-12-01

Microgravity surveys on volcanoes provide insight into the mechanisms of volcanic eruptions. Typically gravity is measured repeatedly over a dense network of stations using one or more meters. Raw gravity measurements corrected for effects of earthtides, instrumental drift, and concurrent elevation changes give residual gravity. Successive surveys give residual gravity changes reflecting mass redistributions within volcanoes affected by dynamic magmatic and/or hydrothermal systems. At Kilauea Volcano a network about 65 stations was most recently reoccupied by Johnson and Eggers in October and November 2003, and by Johnson in 1999 and 1998. Data from 1977 and 1981 surveys (by H.V.O. staff) are included in this study. The reduced gravity data (precision about 10 microgals) show residual gravity has consistently and steadily increased by more than 300 microgals since 1977 in a semicircular area several hundred meters in diameter, centered on the SE rim of Halemaumau Crater. Residual gravity change anomalies for the intervals 1999-2003, 1981-1999, and 1977-1981 have respective amplitudes of approximately 100, 140, and 100 microgals. Because of lower station density and lack of station-to-station continuity over time anomalies representing the two earlier intervals are less well defined. Half-widths at half-heights of the anomalies from each interval indicate a source depths for the masses producing the gravity change of 550 to 700 m below the caldera floor. Mogi point mass interpretations, assuming a 600 m depth, using the 100, 140, and 100 microgal respective amplitudes suggest a cumulative mass addition of about 18x10^9 kg since 1977. Mass has apparently been added to a shallow chamber below the caldera floor at 0.7x10^9 kg/yr on the average throughout most of the Pu'u `O'o eruption. From 1983-2002 magma throughput in the Kilauea/Pu'u `O'o system has averaged about 3.5x10^1^1kg/yr (Sutton et al 2003). This magma throughput represents only 83-87% of the primary magma feeding the Kilauea magma system (Clague et al 1995), with the missing fraction, olivine, collecting as a cumulate within the volcanic edifice. Of the approximate 0.6x10^1^1kg/yr of olive removed from this throughput, less than 1% needs to collect in a shallow chamber to account for the gravity changes described in this study.

Geodetic Observations Using GNSS, Tiltmeter, and DInSAR, at Tokachi-dake Volcano, Japan

NASA Astrophysics Data System (ADS)

Miyagi, Y.

2017-12-01

Tokachi-dake volcano is located in central Hokkaido, Japan. Middle sized eruptions occurred in 1926, 1962, and 1988-1989, and several small phreatic eruptions also occurred in the meanwhile. After the latest eruption in 1988-1989, many volcanic tremor and active seismicity were revealed. Active fumarolic activities from Taisho crater and 62-2 crater have been observed. In recent years, Tokachi-dake volcano has been observed by using several geodetic techniques, including DInSAR, GNSS, tiltmeter, and gravimeter, to detect regional and local signals associated with volcanic activities. Continuous GNSS stations in summit area operated by Geological Survey of Hokkaido and Hokkaido University [Okazaki et al., 2015] and DInSAR observations using ALOS-2 and TerraSAR-X data have revealed long-term small deformation after 2006 and transient large deformation in May, 2015. We found that these are quite local deformation, because regional GNSS and tiltmeter network did not detect any obvious signals in same period. The remarkable deformation detected by GNSS and DInSAR in the summit area between May and July, 2015, indicates that horizontal displacements are larger than vertical displacements, and westward displacement are much larger than eastward displacement. First, we try to model the deformation pattern using a simple spherical source model [Mogi, 1958] and a dike source model [Okada, 1985]. However, they cannot explain observed deformation because they do not take into consideration a topographic effect in the deformation area. Kawguchi & Miyagi [2016] tried to model the deformation using a boundary element method considering the topographic effect. Consequently, a deformation source which is vertically prolate spheroid beneath the summit shows a better fit between observed and simulated deformation. Annual campaign gravity observations have carried out by several Japanese university and institutes since 2010 [Takahashi et al., 2016]. These reveal that gravity value detected in summit area has decreased more than 0.15mgal up to 2017, which is larger than the gravity value expected from vertical displacements [Okazaki et al., 2017]. In this study, we introduce recent deformation observed by DInSAR, and try to understand the relationship between the deformation and gravity change.

Kinematic GPS Analysis Gives New Insights on the Origin of the Very-Long-Period Seismic Signals at Miyake-Jima Volcano during the Caldera Formation

NASA Astrophysics Data System (ADS)

Munekane, H.; Oikawa, J.; Kobayashi, T.

2014-12-01

Miyake-jima is an active basaltic stratovolcano that is located 200km south of Tokyo, Japan. Its eruption event in 2000 was remarkable in that the large caldera was formed at the summit in approximately one month. During the caldera forming stage, very-long-period (VLP) seismic pulse waves with a duration of about 50-s that were accompanied by the step-like inflation were repeatedly recorded. Based on the broadband seismometer data, the piston model is proposed in which a vertical piston of solid materials in the conduit is intermittently sucked into the magma chamber located 3-5 km beneath the edific. In this study, we used the kinematic displacements from the continuous GPS observation to obtain additonal insights on the source mechanism of the pulse waves. 　We calculated the kinematic displacements of 15 GPS stations on Miyake-jima that were in operation at that time at 30 sec interval. Then we extracted the displacements associated with each event using 20-hour time window centered at the occurrence of the event, and stacked the whole time series to obtain mean displacement time series. The obtained time series contain: 1) step-like displacements associated with the pulse waves, 2) exponential decay following the events with time constant of approximately half-day, and 3) steady linear displacements indicating continuous contraction of the edifice. The type one displacements can be attributed to the simultaneous inflation of an mogi-type spherical pressure source located at the depth of 3.6 km under the edifice, and the opening of the nearby vertical dike whose top is at the depth of 2.3 km. The type two displacements can be interpreted as the pressure adjustment at the type one source by the outflow of the magma driven by the pressure difference between the type one source and surrounding area. The type three displacements can be interpreted as the steady outflow of the magma from the type one source. The above results support the ``piston model'' for the source of the pulse waves. However, it seems that the pressure increases by the collapse of the piston are not adjusted by the steady magma outflow as the ``piston model'' suggests but by the pressure-driven magma outflow. The steady magma outflow instead seems to be responsible for the long-term shrinkage of the edifice observed at that period.

Tropical fruit trees as bioindicators of industrial air pollution in southeast Brazil.

PubMed

Moraes, R M; Klumpp, A; Furlan, C M; Klumpp, G; Domingos, M; Rinaldi, M C S; Modesto, I F

2002-11-01

Psidium guajava L., Psidium cattleyanum Sabine and Mangifera indica L. were tested under field conditions as possible tropical bioindicators of industrial air pollution. The study was performed around the industrial complex of Cubatão, SE Brazil, which comprises 23 industries, including fertilizer, cement, chemical, petrochemical, and steel plants, with 110 production units and 260 emission sources of pollutants. Saplings were exposed to environmental conditions during four periods of 16 weeks each (September 1994-September 1995), at four different sites in the coastal mountains near the industrial complex: the Valley of Pilões River (VP), the reference area; the Valley of Mogi River (VM), with high contamination of particulate matter, fluorides (F), sulfur (S) and nitrogen (N) compounds; Caminho do Mar (CM1, CM2), mainly affected by organic pollutants, S and N compounds, and secondary pollutants; and Paranapiacaba (PP), affected by secondary pollutants, such as ozone. M. indica did not adapt to the climatic conditions at the exposure sites. In the two Psidium species, the presence of visible symptoms, root/shoot ratio, foliar contents of F, S and N, amounts of ascorbate (AA) and water-soluble thiols (-SH), as well as peroxidase activity (POD) were determined. P. guajava showed higher foliar accumulation of F, S and N, more pronounced alterations of biochemical indicators, and less visible leaf injury than P. cattleyanum. P. guajava may be used as an accumulative indicator in tropical climates, while further studies will be needed before P. cattleyanum might be applied as a sensitive species in biomonitoring programs.

Two grave issues concerning the expected Tokai Earthquake

NASA Astrophysics Data System (ADS)

Mogi, K.

2004-08-01

The possibility of a great shallow earthquake (M 8) in the Tokai region, central Honshu, in the near future was pointed out by Mogi in 1969 and by the Coordinating Committee for Earthquake Prediction (CCEP), Japan (1970). In 1978, the government enacted the Large-Scale Earthquake Countermeasures Law and began to set up intensified observations in this region for short-term prediction of the expected Tokai earthquake. In this paper, two serious issues are pointed out, which may contribute to catastrophic effects in connection with the Tokai earthquake: 1. The danger of black-and-white predictions: According to the scenario based on the Large-Scale Earthquake Countermeasures Law, if abnormal crustal changes are observed, the Earthquake Assessment Committee (EAC) will determine whether or not there is an imminent danger. The findings are reported to the Prime Minister who decides whether to issue an official warning statement. Administrative policy clearly stipulates the measures to be taken in response to such a warning, and because the law presupposes the ability to predict a large earthquake accurately, there are drastic measures appropriate to the situation. The Tokai region is a densely populated region with high social and economic activity, and it is traversed by several vital transportation arteries. When a warning statement is issued, all transportation is to be halted. The Tokyo capital region would be cut off from the Nagoya and Osaka regions, and there would be a great impact on all of Japan. I (the former chairman of EAC) maintained that in view of the variety and complexity of precursory phenomena, it was inadvisable to attempt a black-and-white judgment as the basis for a "warning statement". I urged that the government adopt a "soft warning" system that acknowledges the uncertainty factor and that countermeasures be designed with that uncertainty in mind. 2. The danger of nuclear power plants in the focal region: Although the possibility of the occurrence of a great shallow earthquake in the Tokai region was pointed out by CCEP in 1970, soon after, plans for construction of a nuclear power plant started in this region. Since 1976, Hamaoka nuclear power plants (Units 1˜4) have been operating near the center of the expected focal region of the great Tokai earthquake, and Unit 5 is under construction. This is quite a dangerous situation.

Seismicity and subsidence following the 2011 Nabro eruption, Eritrea: Insights into the plumbing system of an off-rift volcano

NASA Astrophysics Data System (ADS)

Hamlyn, Joanna E.; Keir, Derek; Wright, Tim J.; Neuberg, Jürgen W.; Goitom, Berhe; Hammond, James O. S.; Pagli, Carolina; Oppenheimer, Clive; Kendall, J.-Michael; Grandin, Raphaël.

2014-11-01

Nabro volcano, situated to the east of the Afar Rift Zone, erupted on 12 June 2011. Eruptions at such off-rift volcanoes are infrequent, and consequently, the plumbing systems are poorly understood. We present posteruption Synthetic Aperture Radar (SAR) images from the TerraSAR-X satellite and posteruption continuous seismic activity from a local seismic array. Interferometric analysis of SAR data, reveals a circular, 12 km wide, signal subsiding at ˜200 mm/yr. We inverted for the best fit Mogi source finding a 4 ± 1 × 107 m3/yr volume decrease at 7 ± 1 km depth. Between 31 August and 7 October 2011, we located 658 and relocated 456 earthquakes with local magnitudes between -0.4 and 4.5. Seismicity beneath the SE edge of Nabro at 11 km depth is likely associated with high strain rates from deep magma flow into the modeled reservoir. This suggests that magma is supplied through a narrow conduit and then stored at ˜7 km depth. We interpret seismicity at 4-6 km depth as brittle fracturing above the inferred magma reservoir. Focal mechanisms delineate a thrust fault striking NE-SW and dipping 45° to the SE across the caldera floor. We propose that the crustal response is to slip on this fault which crosscuts the caldera rather than to deform on ring faults. The NE-SW fault plane is not associated with measurable surface deformation, indicating that it does not contribute much to the caldera deformation. We show that subsidence of the caldera is controlled by magma chamber processes rather than fault slip.

[A landscape ecological approach for urban non-point source pollution control].

PubMed

Guo, Qinghai; Ma, Keming; Zhao, Jingzhu; Yang, Liu; Yin, Chengqing

2005-05-01

Urban non-point source pollution is a new problem appeared with the speeding development of urbanization. The particularity of urban land use and the increase of impervious surface area make urban non-point source pollution differ from agricultural non-point source pollution, and more difficult to control. Best Management Practices (BMPs) are the effective practices commonly applied in controlling urban non-point source pollution, mainly adopting local repairing practices to control the pollutants in surface runoff. Because of the close relationship between urban land use patterns and non-point source pollution, it would be rational to combine the landscape ecological planning with local BMPs to control the urban non-point source pollution, which needs, firstly, analyzing and evaluating the influence of landscape structure on water-bodies, pollution sources and pollutant removal processes to define the relationships between landscape spatial pattern and non-point source pollution and to decide the key polluted fields, and secondly, adjusting inherent landscape structures or/and joining new landscape factors to form new landscape pattern, and combining landscape planning and management through applying BMPs into planning to improve urban landscape heterogeneity and to control urban non-point source pollution.

Inferring Models of Bacterial Dynamics toward Point Sources

PubMed Central

Jashnsaz, Hossein; Nguyen, Tyler; Petrache, Horia I.; Pressé, Steve

2015-01-01

Experiments have shown that bacteria can be sensitive to small variations in chemoattractant (CA) concentrations. Motivated by these findings, our focus here is on a regime rarely studied in experiments: bacteria tracking point CA sources (such as food patches or even prey). In tracking point sources, the CA detected by bacteria may show very large spatiotemporal fluctuations which vary with distance from the source. We present a general statistical model to describe how bacteria locate point sources of food on the basis of stochastic event detection, rather than CA gradient information. We show how all model parameters can be directly inferred from single cell tracking data even in the limit of high detection noise. Once parameterized, our model recapitulates bacterial behavior around point sources such as the “volcano effect”. In addition, while the search by bacteria for point sources such as prey may appear random, our model identifies key statistical signatures of a targeted search for a point source given any arbitrary source configuration. PMID:26466373

A Method for Identifying Pollution Sources of Heavy Metals and PAH for a Risk-Based Management of a Mediterranean Harbour

PubMed Central

Moranda, Arianna

2017-01-01

A procedure for assessing harbour pollution by heavy metals and PAH and the possible sources of contamination is proposed. The procedure is based on a ratio-matching method applied to the results of principal component analysis (PCA), and it allows discrimination between point and nonpoint sources. The approach can be adopted when many sources of pollution can contribute in a very narrow coastal ecosystem, both internal and outside but close to the harbour, and was used to identify the possible point sources of contamination in a Mediterranean Harbour (Port of Vado, Savona, Italy). 235 sediment samples were collected in 81 sampling points during four monitoring campaigns and 28 chemicals were searched for within the collected samples. PCA of total samples allowed the assessment of 8 main possible point sources, while the refining ratio-matching identified 1 sampling point as a possible PAH source, 2 sampling points as Cd point sources, and 3 sampling points as C > 12 point sources. By a map analysis it was possible to assess two internal sources of pollution directly related to terminals activity. The study is the prosecution of a previous work aimed at assessing Savona-Vado Harbour pollution levels and suggested strategies to regulate the harbour activities. PMID:29270328

A Method for Identifying Pollution Sources of Heavy Metals and PAH for a Risk-Based Management of a Mediterranean Harbour.

PubMed

Paladino, Ombretta; Moranda, Arianna; Seyedsalehi, Mahdi

2017-01-01

A procedure for assessing harbour pollution by heavy metals and PAH and the possible sources of contamination is proposed. The procedure is based on a ratio-matching method applied to the results of principal component analysis (PCA), and it allows discrimination between point and nonpoint sources. The approach can be adopted when many sources of pollution can contribute in a very narrow coastal ecosystem, both internal and outside but close to the harbour, and was used to identify the possible point sources of contamination in a Mediterranean Harbour (Port of Vado, Savona, Italy). 235 sediment samples were collected in 81 sampling points during four monitoring campaigns and 28 chemicals were searched for within the collected samples. PCA of total samples allowed the assessment of 8 main possible point sources, while the refining ratio-matching identified 1 sampling point as a possible PAH source, 2 sampling points as Cd point sources, and 3 sampling points as C > 12 point sources. By a map analysis it was possible to assess two internal sources of pollution directly related to terminals activity. The study is the prosecution of a previous work aimed at assessing Savona-Vado Harbour pollution levels and suggested strategies to regulate the harbour activities.

NON-POINT SOURCE POLLUTION

EPA Science Inventory

Non-point source pollution is a diffuse source that is difficult to measure and is highly variable due to different rain patterns and other climatic conditions. In many areas, however, non-point source pollution is the greatest source of water quality degradation. Presently, stat...

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.

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.

Volume 2 - Point Sources

EPA Pesticide Factsheets

Point source emission reference materials from the Emissions Inventory Improvement Program (EIIP). Provides point source guidance on planning, emissions estimation, data collection, inventory documentation and reporting, and quality assurance/quality contr

Using CSLD Method to Calculate COD Pollution Load of Wei River Watershed above Huaxian Section, China

NASA Astrophysics Data System (ADS)

Zhu, Lei; Song, JinXi; Liu, WanQing

2017-12-01

Huaxian Section is the last hydrological and water quality monitoring section of Weihe River Watershed. Weihe River Watershed above Huaxian 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 new method to estimate pollution loads—characteristic section load(CSLD) method is suggested and point source pollution and non-point source pollution loads of Weihe River Watershed above Huaxian Section are calculated in the rainy, normal and dry season in the year 2007. The results show that the monthly point source pollution loads of Weihe River Watershed above Huaxian Section discharge stably and the monthly non-point source pollution loads of Weihe River Watershed above Huaxian Section change greatly and the non-point source pollution load proportions of total pollution load of COD decrease in the normal, rainy and wet period in turn.

Calculating NH3-N pollution load of wei river watershed above Huaxian section using CSLD method

NASA Astrophysics Data System (ADS)

Zhu, Lei; Song, JinXi; Liu, WanQing

2018-02-01

Huaxian Section is the last hydrological and water quality monitoring section of Weihe River Watershed. So it is taken as the research objective in this paper and NH3-N is chosen as the water quality parameter. According to the discharge characteristics of point source pollutions and non-point source pollutions, a new method to estimate pollution loads—characteristic section load (CSLD)method is suggested and point source pollution and non-point source pollution loads of Weihe River Watershed above Huaxian Section are calculated in the rainy, normal and dry season in the year 2007. The results show that the monthly point source pollution loads of Weihe River Watershed above Huaxian Section discharge stably and the monthly non-point source pollution loads of Weihe River Watershed above Huaxian Section change greatly. The non-point source pollution load proportions of total pollution load of NH3-N decrease in the normal, rainy and wet period in turn.

Interferometry with flexible point source array for measuring complex freeform surface and its design algorithm

NASA Astrophysics Data System (ADS)

Li, Jia; Shen, Hua; Zhu, Rihong; Gao, Jinming; Sun, Yue; Wang, Jinsong; Li, Bo

2018-06-01

The precision of the measurements of aspheric and freeform surfaces remains the primary factor restrict their manufacture and application. One effective means of measuring such surfaces involves using reference or probe beams with angle modulation, such as tilted-wave-interferometer (TWI). It is necessary to improve the measurement efficiency by obtaining the optimum point source array for different pieces before TWI measurements. For purpose of forming a point source array based on the gradients of different surfaces under test, we established a mathematical model describing the relationship between the point source array and the test surface. However, the optimal point sources are irregularly distributed. In order to achieve a flexible point source array according to the gradient of test surface, a novel interference setup using fiber array is proposed in which every point source can be independently controlled on and off. Simulations and the actual measurement examples of two different surfaces are given in this paper to verify the mathematical model. Finally, we performed an experiment of testing an off-axis ellipsoidal surface that proved the validity of the proposed interference system.

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.

GARLIC, A SHIELDING PROGRAM FOR GAMMA RADIATION FROM LINE- AND CYLINDER- SOURCES

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

Roos, M.

1959-06-01

GARLlC is a program for computing the gamma ray flux or dose rate at a shielded isotropic point detector, due to a line source or the line equivalent of a cylindrical source. The source strength distribution along the line must be either uniform or an arbitrary part of the positive half-cycle of a cosine function The line source can be orierted arbitrarily with respect to the main shield and the detector, except that the detector must not be located on the line source or on its extensionThe main source is a homogeneous plane slab in which scattered radiation is accountedmore » for by multiplying each point element of the line source by a point source buildup factor inside the integral over the point elements. Between the main shield and the line source additional shields can be introduced, which are either plane slabs, parallel to the main shield, or cylindrical rings, coaxial with the line source. Scattered radiation in the additional shields can only be accounted for by constant build-up factors outside the integral. GARLlC-xyz is an extended version particularly suited for the frequently met problem of shielding a room containing a large number of line sources in diHerent positions. The program computes the angles and linear dimensions of a problem for GARLIC when the positions of the detector point and the end points of the line source are given as points in an arbitrary rectangular coordinate system. As an example the isodose curves in water are presented for a monoenergetic cosine-distributed line source at several source energies and for an operating fuel element of the Swedish reactor R3, (auth)« less

The identification of Josef Mengele. A triumph of international cooperation.

PubMed

Eckert, W G; Teixeira, W R

1985-09-01

In recent weeks, world attention has been focused on the identification of skeletal remains suspected of being those of the most widely sought Nazi war criminal still at large--Josef Mengele. Several important turns in the investigation of his whereabouts led to a small city south of São Paulo, where he had been living until 1979. Mengele was reported to have drowned and to have been buried in a country cemetery near his last residence. The initial processing of the remains was done at the Medicolegal Institute of São Paulo by police officials in consultation with anthropologists and dentists as well as Dr. Wilmes Teixeira of Mogi das Cruzes, a suburb of São Paulo. Dr. Teixeira coordinated the team of authorized international forensic experts officially representing the governments of West Germany and the United States, as well as the Simon Wiesenthal Center of Los Angeles, who joined Brazilian scientists in completing identification. The success of the investigation was due to complete cooperation among members of the team, resulting in verification, within a reasonable scientific certainty, that these were the remains of Josef Mengele.

40 CFR 51.35 - How can my state equalize the emission inventory effort from year to year?

Code of Federal Regulations, 2012 CFR

2012-07-01

... approach: (1) Each year, collect and report data for all Type A (large) point sources (this is required for all Type A point sources). (2) Each year, collect data for one-third of your sources that are not Type... save 3 years of data and then report all emissions from the sources that are not Type A point sources...

40 CFR 51.35 - How can my state equalize the emission inventory effort from year to year?

Code of Federal Regulations, 2010 CFR

2010-07-01

... approach: (1) Each year, collect and report data for all Type A (large) point sources (this is required for all Type A point sources). (2) Each year, collect data for one-third of your sources that are not Type... save 3 years of data and then report all emissions from the sources that are not Type A point sources...

40 CFR 51.35 - How can my state equalize the emission inventory effort from year to year?

Code of Federal Regulations, 2014 CFR

2014-07-01

... approach: (1) Each year, collect and report data for all Type A (large) point sources (this is required for all Type A point sources). (2) Each year, collect data for one-third of your sources that are not Type... save 3 years of data and then report all emissions from the sources that are not Type A point sources...

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.

Calculation and analysis of the non-point source pollution in the upstream watershed of the Panjiakou Reservoir, People's Republic of China

NASA Astrophysics Data System (ADS)

Zhang, S.; Tang, L.

2007-05-01

Panjiakou Reservoir is an important drinking water resource in Haihe River Basin, Hebei Province, People's Republic of China. The upstream watershed area is about 35,000 square kilometers. Recently, the water pollution in the reservoir is becoming more serious owing to the non-point pollution as well as point source pollution on the upstream watershed. To effectively manage the reservoir and watershed and develop a plan to reduce pollutant loads, the loading of non-point and point pollution and their distribution on the upstream watershed must be understood fully. The SWAT model is used to simulate the production and transportation of the non-point source pollutants in the upstream watershed of the Panjiakou Reservoir. The loadings of non-point source pollutants are calculated for different hydrologic years and the spatial and temporal characteristics of non-point source pollution are studied. The stream network and topographic characteristics of the stream network and sub-basins are all derived from the DEM by ArcGIS software. The soil and land use data are reclassified and the soil physical properties database file is created for the model. The SWAT model was calibrated with observed data of several hydrologic monitoring stations in the study area. The results of the calibration show that the model performs fairly well. Then the calibrated model was used to calculate the loadings of non-point source pollutants for a wet year, a normal year and a dry year respectively. The time and space distribution of flow, sediment and non-point source pollution were analyzed depending on the simulated results. The comparison of different hydrologic years on calculation results is dramatic. The loading of non-point source pollution in the wet year is relatively larger but smaller in the dry year since the non-point source pollutants are mainly transported through the runoff. The pollution loading within a year is mainly produced in the flood season. Because SWAT is a distributed model, it is possible to view model output as it varies across the basin, so the critical areas and reaches can be found in the study area. According to the simulation results, it is found that different land uses can yield different results and fertilization in rainy season has an important impact on the non- point source pollution. The limitations of the SWAT model are also discussed and the measures of the control and prevention of non- point source pollution for Panjiakou Reservoir are presented according to the analysis of model calculation results.

Active control on high-order coherence and statistic characterization on random phase fluctuation of two classical point sources.

PubMed

Hong, Peilong; Li, Liming; Liu, Jianji; Zhang, Guoquan

2016-03-29

Young's double-slit or two-beam interference is of fundamental importance to understand various interference effects, in which the stationary phase difference between two beams plays the key role in the first-order coherence. Different from the case of first-order coherence, in the high-order optical coherence the statistic behavior of the optical phase will play the key role. In this article, by employing a fundamental interfering configuration with two classical point sources, we showed that the high- order optical coherence between two classical point sources can be actively designed by controlling the statistic behavior of the relative phase difference between two point sources. Synchronous position Nth-order subwavelength interference with an effective wavelength of λ/M was demonstrated, in which λ is the wavelength of point sources and M is an integer not larger than N. Interestingly, we found that the synchronous position Nth-order interference fringe fingerprints the statistic trace of random phase fluctuation of two classical point sources, therefore, it provides an effective way to characterize the statistic properties of phase fluctuation for incoherent light sources.

Ghost imaging with bucket detection and point detection

NASA Astrophysics Data System (ADS)

Zhang, De-Jian; Yin, Rao; Wang, Tong-Biao; Liao, Qing-Hua; Li, Hong-Guo; Liao, Qinghong; Liu, Jiang-Tao

2018-04-01

We experimentally investigate ghost imaging with bucket detection and point detection in which three types of illuminating sources are applied: (a) pseudo-thermal light source; (b) amplitude modulated true thermal light source; (c) amplitude modulated laser source. Experimental results show that the quality of ghost images reconstructed with true thermal light or laser beam is insensitive to the usage of bucket or point detector, however, the quality of ghost images reconstructed with pseudo-thermal light in bucket detector case is better than that in point detector case. Our theoretical analysis shows that the reason for this is due to the first order transverse coherence of the illuminating source.

Distinguishing dark matter from unresolved point sources in the Inner Galaxy with photon statistics

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

Lee, Samuel K.; Lisanti, Mariangela; Safdi, Benjamin R., E-mail: samuelkl@princeton.edu, E-mail: mlisanti@princeton.edu, E-mail: bsafdi@princeton.edu

2015-05-01

Data from the Fermi Large Area Telescope suggests that there is an extended excess of GeV gamma-ray photons in the Inner Galaxy. Identifying potential astrophysical sources that contribute to this excess is an important step in verifying whether the signal originates from annihilating dark matter. In this paper, we focus on the potential contribution of unresolved point sources, such as millisecond pulsars (MSPs). We propose that the statistics of the photons—in particular, the flux probability density function (PDF) of the photon counts below the point-source detection threshold—can potentially distinguish between the dark-matter and point-source interpretations. We calculate the flux PDFmore » via the method of generating functions for these two models of the excess. Working in the framework of Bayesian model comparison, we then demonstrate that the flux PDF can potentially provide evidence for an unresolved MSP-like point-source population.« less

Strong ground motion simulation of the 2016 Kumamoto earthquake of April 16 using multiple point sources

NASA Astrophysics Data System (ADS)

Nagasaka, Yosuke; Nozu, Atsushi

2017-02-01

The pseudo point-source model approximates the rupture process on faults with multiple point sources for simulating strong ground motions. A simulation with this point-source model is conducted by combining a simple source spectrum following the omega-square model with a path spectrum, an empirical site amplification factor, and phase characteristics. Realistic waveforms can be synthesized using the empirical site amplification factor and phase models even though the source model is simple. The Kumamoto earthquake occurred on April 16, 2016, with M JMA 7.3. Many strong motions were recorded at stations around the source region. Some records were considered to be affected by the rupture directivity effect. This earthquake was suitable for investigating the applicability of the pseudo point-source model, the current version of which does not consider the rupture directivity effect. Three subevents (point sources) were located on the fault plane, and the parameters of the simulation were determined. The simulated results were compared with the observed records at K-NET and KiK-net stations. It was found that the synthetic Fourier spectra and velocity waveforms generally explained the characteristics of the observed records, except for underestimation in the low frequency range. Troughs in the observed Fourier spectra were also well reproduced by placing multiple subevents near the hypocenter. The underestimation is presumably due to the following two reasons. The first is that the pseudo point-source model targets subevents that generate strong ground motions and does not consider the shallow large slip. The second reason is that the current version of the pseudo point-source model does not consider the rupture directivity effect. Consequently, strong pulses were not reproduced enough at stations northeast of Subevent 3 such as KMM004, where the effect of rupture directivity was significant, while the amplitude was well reproduced at most of the other stations. This result indicates the necessity for improving the pseudo point-source model, by introducing azimuth-dependent corner frequency for example, so that it can incorporate the effect of rupture directivity.[Figure not available: see fulltext.

STATISTICS OF GAMMA-RAY POINT SOURCES BELOW THE FERMI DETECTION LIMIT

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

Malyshev, Dmitry; Hogg, David W., E-mail: dm137@nyu.edu

2011-09-10

An analytic relation between the statistics of photons in pixels and the number counts of multi-photon point sources is used to constrain the distribution of gamma-ray point sources below the Fermi detection limit at energies above 1 GeV and at latitudes below and above 30 deg. The derived source-count distribution is consistent with the distribution found by the Fermi Collaboration based on the first Fermi point-source catalog. In particular, we find that the contribution of resolved and unresolved active galactic nuclei (AGNs) to the total gamma-ray flux is below 20%-25%. In the best-fit model, the AGN-like point-source fraction is 17%more » {+-} 2%. Using the fact that the Galactic emission varies across the sky while the extragalactic diffuse emission is isotropic, we put a lower limit of 51% on Galactic diffuse emission and an upper limit of 32% on the contribution from extragalactic weak sources, such as star-forming galaxies. Possible systematic uncertainties are discussed.« less

MODELING PHOTOCHEMISTRY AND AEROSOL FORMATION IN POINT SOURCE PLUMES WITH THE CMAQ PLUME-IN-GRID

EPA Science Inventory

Emissions of nitrogen oxides and sulfur oxides from the tall stacks of major point sources are important precursors of a variety of photochemical oxidants and secondary aerosol species. Plumes released from point sources exhibit rather limited dimensions and their growth is gradu...

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.

Rapid dike intrusion into Sakurajima volcano on August 15, 2015, as detected by multi-parameter ground deformation observations

NASA Astrophysics Data System (ADS)

Hotta, Kohei; Iguchi, Masato; Tameguri, Takeshi

2016-04-01

We present observations of ground deformation at Sakurajima in August 2015 and model the deformation using a combination of GNSS, tilt and strain data in order to interpret a rapid deformation event on August 15, 2015. The pattern of horizontal displacement during the period from August 14 to 16, 2015, shows a WNW-ESE extension, which suggests the opening of a dike. Using a genetic algorithm, we obtained the position, dip, strike length, width and opening of a dislocation source based on the combined data. A nearly vertical dike with a NNE-SSW strike was found at a depth of 1.0 km below sea level beneath the Showa crater. The length and width are 2.3 and 0.6 km, respectively, and a dike opening of 1.97 m yields a volume increase of 2.7 × 106 m3. 887 volcano-tectonic (VT) earthquakes beside the dike suggest that the rapid opening of the dike caused an accumulation of strain in the surrounding rocks, and the VT earthquakes were generated to release this strain. Half of the total amount of deformation was concentrated between 10:27 and 11:54 on August 15. It is estimated that the magma intrusion rate was 1 × 106 m3/h during this period. This is 200 times larger than the magma intrusion rate prior to one of the biggest eruptions at the summit crater of Minami-dake on July 24, 2012, and 2200 times larger than the average magma intrusion rate during the period from October 2011 to March 2012. The previous Mogi-type ground deformation is considered to be a process of magma accumulation in preexisting spherical reservoirs. Conversely, the August 2015 event was a dike intrusion and occurred in a different location to the preexisting reservoirs. The direction of the opening of the dike coincides with the T-axes and direction of faults creating a graben structure.

Determination of efficiency of an aged HPGe detector for gaseous sources by self absorption correction and point source methods

NASA Astrophysics Data System (ADS)

Sarangapani, R.; Jose, M. T.; Srinivasan, T. K.; Venkatraman, B.

2017-07-01

Methods for the determination of efficiency of an aged high purity germanium (HPGe) detector for gaseous sources have been presented in the paper. X-ray radiography of the detector has been performed to get detector dimensions for computational purposes. The dead layer thickness of HPGe detector has been ascertained from experiments and Monte Carlo computations. Experimental work with standard point and liquid sources in several cylindrical geometries has been undertaken for obtaining energy dependant efficiency. Monte Carlo simulations have been performed for computing efficiencies for point, liquid and gaseous sources. Self absorption correction factors have been obtained using mathematical equations for volume sources and MCNP simulations. Self-absorption correction and point source methods have been used to estimate the efficiency for gaseous sources. The efficiencies determined from the present work have been used to estimate activity of cover gas sample of a fast reactor.

Discrimination between diffuse and point sources of arsenic at Zimapán, Hidalgo state, Mexico.

PubMed

Sracek, Ondra; Armienta, María Aurora; Rodríguez, Ramiro; Villaseñor, Guadalupe

2010-01-01

There are two principal sources of arsenic in Zimapán. Point sources are linked to mining and smelting activities and especially to mine tailings. Diffuse sources are not well defined and are linked to regional flow systems in carbonate rocks. Both sources are caused by the oxidation of arsenic-rich sulfidic mineralization. Point sources are characterized by Ca-SO(4)-HCO(3) ground water type and relatively enriched values of deltaD, delta(18)O, and delta(34)S(SO(4)). Diffuse sources are characterized by Ca-Na-HCO(3) type of ground water and more depleted values of deltaD, delta(18)O, and delta(34)S(SO(4)). Values of deltaD and delta(18)O indicate similar altitude of recharge for both arsenic sources and stronger impact of evaporation for point sources in mine tailings. There are also different values of delta(34)S(SO(4)) for both sources, presumably due to different types of mineralization or isotopic zonality in deposits. In Principal Component Analysis (PCA), the principal component 1 (PC1), which describes the impact of sulfide oxidation and neutralization by the dissolution of carbonates, has higher values in samples from point sources. In spite of similar concentrations of As in ground water affected by diffuse sources and point sources (mean values 0.21 mg L(-1) and 0.31 mg L(-1), respectively, in the years from 2003 to 2008), the diffuse sources have more impact on the health of population in Zimapán. This is caused by the extraction of ground water from wells tapping regional flow system. In contrast, wells located in the proximity of mine tailings are not generally used for water supply.

Interplanetary Scintillation studies with the Murchison Wide-field Array III: Comparison of source counts and densities for radio sources and their sub-arcsecond components at 162 MHz

NASA Astrophysics Data System (ADS)

Chhetri, R.; Ekers, R. D.; Morgan, J.; Macquart, J.-P.; Franzen, T. M. O.

2018-06-01

We use Murchison Widefield Array observations of interplanetary scintillation (IPS) to determine the source counts of point (<0.3 arcsecond extent) sources and of all sources with some subarcsecond structure, at 162 MHz. We have developed the methodology to derive these counts directly from the IPS observables, while taking into account changes in sensitivity across the survey area. The counts of sources with compact structure follow the behaviour of the dominant source population above ˜3 Jy but below this they show Euclidean behaviour. We compare our counts to those predicted by simulations and find a good agreement for our counts of sources with compact structure, but significant disagreement for point source counts. Using low radio frequency SEDs from the GLEAM survey, we classify point sources as Compact Steep-Spectrum (CSS), flat spectrum, or peaked. If we consider the CSS sources to be the more evolved counterparts of the peaked sources, the two categories combined comprise approximately 80% of the point source population. We calculate densities of potential calibrators brighter than 0.4 Jy at low frequencies and find 0.2 sources per square degrees for point sources, rising to 0.7 sources per square degree if sources with more complex arcsecond structure are included. We extrapolate to estimate 4.6 sources per square degrees at 0.04 Jy. We find that a peaked spectrum is an excellent predictor for compactness at low frequencies, increasing the number of good calibrators by a factor of three compared to the usual flat spectrum criterion.

Magmatic-Tectonic Interactions: Implications for Seismic Hazard Assessment in the Central Walker Lane and Long Valley Caldera Regions

NASA Astrophysics Data System (ADS)

Chacko, R.; Hammond, W. C.; Blewitt, G.; Bormann, J. M.

2014-12-01

Accurate estimates of fault slip rates based on geodetic data rely on measurements that represent the long-term deformation of the crust. In the Central Walker Lane/Sierra Nevada transition, the Long Valley Caldera region has experienced multiple episodes of uplift and subsidence during the last four decades. The latest episode began in late 2011 and is detectable as a transient signal in the time series of GPS stations around the caldera. These transient signals become more apparent and reveal the extent of the impact on the ambient crustal deformation field of the Walker Lane when the velocity vectors are transformed to a Sierra-Nevada reference frame. Estimating contemporary slip-rates on faults for the purpose of seismic hazard assessment in the region around Long Valley requires detecting and subtracting the transient signals caused by the uplift and subsidence in the caldera. We estimate the geographic extent to which the ambient crustal deformation field is significantly perturbed by ongoing magmatic activity in Long Valley. We present a time variable 3D deformation field constrained by InSAR and GPS observations, and discuss the implications that tectonic-magmatic interaction have for estimates of present-day fault slip-rate. We model the time dependent deformation at Long Valley by analyzing InSAR time series from Envisat and ERS interferograms spanning a period of more than 19 years. We use an analytical volcano deformation source model derived from vertical (GPS) and line of site (InSAR) component of geodetic observations to estimate the horizontal component of the signals associated with magmatic activity beneath the caldera. Previous studies showed that the latest episode of uplift can be modeled with a Mogi source located at a depth of ~6 km with a volume change of 0.03 km3 beneath the resurgent dome. This model predicts a perturbation to the ambient crustal deformation field extending as far as 60 km from the center of the resurgent dome. Thus the area affected by Long Valley extends from north of Mono Lake southward to Owens Lake, and eastward to the Mina deflection of the Walker Lane, potentially influencing the estimated slip rates for a dozen or more major faults.

PICTURES (Pisagua/Iquique Crustal Tomography to Understand the Region of the Earthquake Source): seismic imaging of the source region of the April 1, 2014 Mw 8.2 earthquake offshore northern Chile

NASA Astrophysics Data System (ADS)

Trehu, A. M.

2017-12-01

The 2014 event partially filled a well-recognized seismic gap that had not experienced a large earthquake since a pair of devastating M9 events in 1868 and 1877. The rupture sequence was marked by an unusually long and distinct precursory period that was well recorded by onshore seismic and geodetic instruments of the Integrated Plate Boundary Observatory Chile (IPOC). The pattern of foreshock activity, which defined a "classic" Mogi donut, is correlated with a circular residual gravity high that surrounds the patch of greatest slip during the main shock. Aftershocks generally propagated to the south and stopped in a region of relatively low pre-earthquake coupling. The remaining nearly 300-km long seismic gap is correlated with a distinct forearc residual gravity high. The correlation between the pre-, syn- and post-earthquake deformation patterns and the residual gravity anomalies indicates that crustal structure affects the distribution of seismic and aseismic deformation in response to plate convergence. Because the non-uniqueness inherent in modeling gravity data does not allow for a detailed geologic interpretation of the correlation between structure and slip, we conducted an ambitious seismic experiment using the R/V Marcus Langseth to acquire 5000 km of multichannel seismic seismic data using an 8-12.5-km long streamer and a 6600 cubic inch tuned air-gun array. The 45000 shots were also recorded on 70 ocean-bottom and 50 land-based seismometers. Shipboard analysis of the data indicates that the Moho of the Nazca plate is well imaged west of the trench, that deformation is distributed throughout the outer 10 km of the accretionary wedge as the rough topography of the Nazca plate is subducted, and that a reflection tentatively interpreted to be the plate boundary can be imaged continuously from the trench to the coast on at least one transect across the margin. Post-cruise data analysis is underway to process the MCS data using various techniques to determine along-strike continuity of plate boundary reflectivity and to use OBS and onshore large-aperture data to obtain high-resolution models of the crustal velocity structure of the subducting and overriding plates. The PICTURES Science Team incudes investigators in the US, Chile, Germany, France and the UK.

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

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...

40 CFR 409.13 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SUGAR PROCESSING POINT SOURCE CATEGORY Beet Sugar Processing... a point source where the sugar beet processing capacity of the point source does not exceed 1090 kkg... results, in whole or in part, from barometric condensing operations and any other beet sugar processing...

40 CFR 409.13 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SUGAR PROCESSING POINT SOURCE CATEGORY Beet Sugar Processing... a point source where the sugar beet processing capacity of the point source does not exceed 1090 kkg... results, in whole or in part, from barometric condensing operations and any other beet sugar processing...

40 CFR 409.13 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SUGAR PROCESSING POINT SOURCE CATEGORY Beet Sugar Processing... a point source where the sugar beet processing capacity of the point source does not exceed 1090 kkg... results, in whole or in part, from barometric condensing operations and any other beet sugar processing...

40 CFR 409.13 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SUGAR PROCESSING POINT SOURCE CATEGORY Beet Sugar Processing... a point source where the sugar beet processing capacity of the point source does not exceed 1090 kkg... results, in whole or in part, from barometric condensing operations and any other beet sugar processing...

40 CFR 409.13 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SUGAR PROCESSING POINT SOURCE CATEGORY Beet Sugar Processing... a point source where the sugar beet processing capacity of the point source does not exceed 1090 kkg... results, in whole or in part, from barometric condensing operations and any other beet sugar processing...

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.

2011 Radioactive Materials Usage Survey for Unmonitored Point Sources

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

Sturgeon, Richard W.

This report provides the results of the 2011 Radioactive Materials Usage Survey for Unmonitored Point Sources (RMUS), which was updated by the Environmental Protection (ENV) Division's Environmental Stewardship (ES) at Los Alamos National Laboratory (LANL). ES classifies LANL emission sources into one of four Tiers, based on the potential effective dose equivalent (PEDE) calculated for each point source. Detailed descriptions of these tiers are provided in Section 3. The usage survey is conducted annually; in odd-numbered years the survey addresses all monitored and unmonitored point sources and in even-numbered years it addresses all Tier III and various selected other sources.more » This graded approach was designed to ensure that the appropriate emphasis is placed on point sources that have higher potential emissions to the environment. For calendar year (CY) 2011, ES has divided the usage survey into two distinct reports, one covering the monitored point sources (to be completed later this year) and this report covering all unmonitored point sources. This usage survey includes the following release points: (1) all unmonitored sources identified in the 2010 usage survey, (2) any new release points identified through the new project review (NPR) process, and (3) other release points as designated by the Rad-NESHAP Team Leader. Data for all unmonitored point sources at LANL is stored in the survey files at ES. LANL uses this survey data to help demonstrate compliance with Clean Air Act radioactive air emissions regulations (40 CFR 61, Subpart H). The remainder of this introduction provides a brief description of the information contained in each section. Section 2 of this report describes the methods that were employed for gathering usage survey data and for calculating usage, emissions, and dose for these point sources. It also references the appropriate ES procedures for further information. Section 3 describes the RMUS and explains how the survey results are organized. The RMUS Interview Form with the attached RMUS Process Form(s) provides the radioactive materials survey data by technical area (TA) and building number. The survey data for each release point includes information such as: exhaust stack identification number, room number, radioactive material source type (i.e., potential source or future potential source of air emissions), radionuclide, usage (in curies) and usage basis, physical state (gas, liquid, particulate, solid, or custom), release fraction (from Appendix D to 40 CFR 61, Subpart H), and process descriptions. In addition, the interview form also calculates emissions (in curies), lists mrem/Ci factors, calculates PEDEs, and states the location of the critical receptor for that release point. [The critical receptor is the maximum exposed off-site member of the public, specific to each individual facility.] Each of these data fields is described in this section. The Tier classification of release points, which was first introduced with the 1999 usage survey, is also described in detail in this section. Section 4 includes a brief discussion of the dose estimate methodology, and includes a discussion of several release points of particular interest in the CY 2011 usage survey report. It also includes a table of the calculated PEDEs for each release point at its critical receptor. Section 5 describes ES's approach to Quality Assurance (QA) for the usage survey. Satisfactory completion of the survey requires that team members responsible for Rad-NESHAP (National Emissions Standard for Hazardous Air Pollutants) compliance accurately collect and process several types of information, including radioactive materials usage data, process information, and supporting information. They must also perform and document the QA reviews outlined in Section 5.2.6 (Process Verification and Peer Review) of ES-RN, 'Quality Assurance Project Plan for the Rad-NESHAP Compliance Project' to verify that all information is complete and correct.« less

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

Point and Condensed Hα Sources in the Interior of M33

NASA Astrophysics Data System (ADS)

Moody, J. Ward; Hintz, Eric G.; Roming, Peter; Joner, Michael D.; Bucklein, Brian

2017-01-01

A variety of interesting objects such as Wolf-Rayet stars, tight OB associations, planetary nebula, x-ray binaries, etc. can be discovered as point or condensed sources in Hα surveys. How these objects distribute through a galaxy sheds light on the galaxy star formation rate and history, mass distribution, and dynamics. The nearby galaxy M33 is an excellent place to study the distribution of Hα-bright point sources in a flocculant spiral galaxy. We have reprocessed an archived WIYN continuum-subtracted Hα image of the inner 6.5' of the nearby galaxy M33 and, employing both eye and machine searches, have tabulated sources with a flux greater than 1 x 10-15 erg cm-2sec-1. We have identified 152 unresolved point sources and 122 marginally resolved condensed sources, 38 of which have not been previously cataloged. We present a map of these sources and discuss their probable identifications.

A guide to differences between stochastic point-source and stochastic finite-fault simulations

USGS Publications Warehouse

Atkinson, G.M.; Assatourians, K.; Boore, D.M.; Campbell, K.; Motazedian, D.

2009-01-01

Why do stochastic point-source and finite-fault simulation models not agree on the predicted ground motions for moderate earthquakes at large distances? This question was posed by Ken Campbell, who attempted to reproduce the Atkinson and Boore (2006) ground-motion prediction equations for eastern North America using the stochastic point-source program SMSIM (Boore, 2005) in place of the finite-source stochastic program EXSIM (Motazedian and Atkinson, 2005) that was used by Atkinson and Boore (2006) in their model. His comparisons suggested that a higher stress drop is needed in the context of SMSIM to produce an average match, at larger distances, with the model predictions of Atkinson and Boore (2006) based on EXSIM; this is so even for moderate magnitudes, which should be well-represented by a point-source model. Why? The answer to this question is rooted in significant differences between point-source and finite-source stochastic simulation methodologies, specifically as implemented in SMSIM (Boore, 2005) and EXSIM (Motazedian and Atkinson, 2005) to date. Point-source and finite-fault methodologies differ in general in several important ways: (1) the geometry of the source; (2) the definition and application of duration; and (3) the normalization of finite-source subsource summations. Furthermore, the specific implementation of the methods may differ in their details. The purpose of this article is to provide a brief overview of these differences, their origins, and implications. This sets the stage for a more detailed companion article, "Comparing Stochastic Point-Source and Finite-Source Ground-Motion Simulations: SMSIM and EXSIM," in which Boore (2009) provides modifications and improvements in the implementations of both programs that narrow the gap and result in closer agreement. These issues are important because both SMSIM and EXSIM have been widely used in the development of ground-motion prediction equations and in modeling the parameters that control observed ground motions.

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.

Vector image method for the derivation of elastostatic solutions for point sources in a plane layered medium. Part 1: Derivation and simple examples

NASA Technical Reports Server (NTRS)

Fares, Nabil; Li, Victor C.

1986-01-01

An image method algorithm is presented for the derivation of elastostatic solutions for point sources in bonded halfspaces assuming the infinite space point source is known. Specific cases were worked out and shown to coincide with well known solutions in the literature.

40 CFR 414.100 - Applicability; description of the subcategory of direct discharge point sources that do not use...

Code of Federal Regulations, 2010 CFR

2010-07-01

... subcategory of direct discharge point sources that do not use end-of-pipe biological treatment. 414.100... AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Direct Discharge Point Sources That Do Not Use End-of-Pipe Biological Treatment § 414.100 Applicability; description of the subcategory of...

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.

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, R.N.; Faye, R.E.; Kleckner, R.L.

1978-01-01

On an average annual basis and during the storm period of March 12-15, 1976, nonpoint-source loads for most constituents were larger than point-source loads at the Whitesburg station, located on the Chattahoochee River about 40 miles downstream from Atlanta, GA. Most of the nonpoint-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 a low-flow period, June 1-2, 1977, five municipal point-sources contributed 63 percent of the ultimate biochemical oxygen demand, and 97 percent of the ammonium nitrogen loads at the Franklin station, at the upstream end of West Point Lake. Dissolved-oxygen concentrations of 4.1 to 5.0 milligrams per liter occurred in a 22-mile reach of the river downstream from Atlanta due about equally to nitrogenous and carbonaceous oxygen demands. The heat load from two thermoelectric powerplants caused a decrease in dissolved-oxygen concentration of about 0.2 milligrams per liter. Phytoplankton concentrations in West Point Lake, about 70 miles downstream from Atlanta, could exceed three million cells per millimeter during extended low-flow periods in the summer with present point-source phosphorus loads. (Woodard-USGS)

Unidentified point sources in the IRAS minisurvey

NASA Technical Reports Server (NTRS)

Houck, J. R.; Soifer, B. T.; Neugebauer, G.; Beichman, C. A.; Aumann, H. H.; Clegg, P. E.; Gillett, F. C.; Habing, H. J.; Hauser, M. G.; Low, F. J.

1984-01-01

Nine bright, point-like 60 micron sources have been selected from the sample of 8709 sources in the IRAS minisurvey. These sources have no counterparts in a variety of catalogs of nonstellar objects. Four objects have no visible counterparts, while five have faint stellar objects visible in the error ellipse. These sources do not resemble objects previously known to be bright infrared sources.

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.

Modeling deep brain stimulation: point source approximation versus realistic representation of the electrode

NASA Astrophysics Data System (ADS)

Zhang, Tianhe C.; Grill, Warren M.

2010-12-01

Deep brain stimulation (DBS) has emerged as an effective treatment for movement disorders; however, the fundamental mechanisms by which DBS works are not well understood. Computational models of DBS can provide insights into these fundamental mechanisms and typically require two steps: calculation of the electrical potentials generated by DBS and, subsequently, determination of the effects of the extracellular potentials on neurons. The objective of this study was to assess the validity of using a point source electrode to approximate the DBS electrode when calculating the thresholds and spatial distribution of activation of a surrounding population of model neurons in response to monopolar DBS. Extracellular potentials in a homogenous isotropic volume conductor were calculated using either a point current source or a geometrically accurate finite element model of the Medtronic DBS 3389 lead. These extracellular potentials were coupled to populations of model axons, and thresholds and spatial distributions were determined for different electrode geometries and axon orientations. Median threshold differences between DBS and point source electrodes for individual axons varied between -20.5% and 9.5% across all orientations, monopolar polarities and electrode geometries utilizing the DBS 3389 electrode. Differences in the percentage of axons activated at a given amplitude by the point source electrode and the DBS electrode were between -9.0% and 12.6% across all monopolar configurations tested. The differences in activation between the DBS and point source electrodes occurred primarily in regions close to conductor-insulator interfaces and around the insulating tip of the DBS electrode. The robustness of the point source approximation in modeling several special cases—tissue anisotropy, a long active electrode and bipolar stimulation—was also examined. Under the conditions considered, the point source was shown to be a valid approximation for predicting excitation of populations of neurons in response to DBS.

Multiband super-resolution imaging of graded-index photonic crystal flat lens

NASA Astrophysics Data System (ADS)

Xie, Jianlan; Wang, Junzhong; Ge, Rui; Yan, Bei; Liu, Exian; Tan, Wei; Liu, Jianjun

2018-05-01

Multiband super-resolution imaging of point source is achieved by a graded-index photonic crystal flat lens. With the calculations of six bands in common photonic crystal (CPC) constructed with scatterers of different refractive indices, it can be found that the super-resolution imaging of point source can be realized by different physical mechanisms in three different bands. In the first band, the imaging of point source is based on far-field condition of spherical wave while in the second band, it is based on the negative effective refractive index and exhibiting higher imaging quality than that of the CPC. However, in the fifth band, the imaging of point source is mainly based on negative refraction of anisotropic equi-frequency surfaces. The novel method of employing different physical mechanisms to achieve multiband super-resolution imaging of point source is highly meaningful for the field of imaging.

Long Term Temporal and Spectral Evolution of Point Sources in Nearby Elliptical Galaxies

NASA Astrophysics Data System (ADS)

Durmus, D.; Guver, T.; Hudaverdi, M.; Sert, H.; Balman, Solen

2016-06-01

We present the results of an archival study of all the point sources detected in the lines of sight of the elliptical galaxies NGC 4472, NGC 4552, NGC 4649, M32, Maffei 1, NGC 3379, IC 1101, M87, NGC 4477, NGC 4621, and NGC 5128, with both the Chandra and XMM-Newton observatories. Specifically, we studied the temporal and spectral evolution of these point sources over the course of the observations of the galaxies, mostly covering the 2000 - 2015 period. In this poster we present the first results of this study, which allows us to further constrain the X-ray source population in nearby elliptical galaxies and also better understand the nature of individual point sources.

Very Luminous X-ray Point Sources in Starburst Galaxies

NASA Astrophysics Data System (ADS)

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

Extranuclear X-ray point sources in external galaxies with luminosities above 1039.0 erg/s are quite common in elliptical, disk and dwarf galaxies, with an average of ~ 0.5 and dwarf galaxies, with an average of ~0.5 sources per galaxy. These objects may be a new class of object, perhaps accreting intermediate-mass black holes, or beamed stellar mass black hole binaries. Starburst galaxies tend to have a larger number of these intermediate-luminosity X-ray objects (IXOs), as well as a large number of lower-luminosity (1037 - 1039 erg/s) point sources. These point sources dominate the total hard X-ray emission in starburst galaxies. We present a review of both types of objects and discuss possible schemes for their formation.

The resolution of point sources of light as analyzed by quantum detection theory

NASA Technical Reports Server (NTRS)

Helstrom, C. W.

1972-01-01

The resolvability of point sources of incoherent light is analyzed by quantum detection theory in terms of two hypothesis-testing problems. In the first, the observer must decide whether there are two sources of equal radiant power at given locations, or whether there is only one source of twice the power located midway between them. In the second problem, either one, but not both, of two point sources is radiating, and the observer must decide which it is. The decisions are based on optimum processing of the electromagnetic field at the aperture of an optical instrument. In both problems the density operators of the field under the two hypotheses do not commute. The error probabilities, determined as functions of the separation of the points and the mean number of received photons, characterize the ultimate resolvability of the sources.

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

Effects of pointing compared with naming and observing during encoding on item and source memory in young and older adults.

PubMed

Ouwehand, Kim; van Gog, Tamara; Paas, Fred

2016-10-01

Research showed that source memory functioning declines with ageing. Evidence suggests that encoding visual stimuli with manual pointing in addition to visual observation can have a positive effect on spatial memory compared with visual observation only. The present study investigated whether pointing at picture locations during encoding would lead to better spatial source memory than naming (Experiment 1) and visual observation only (Experiment 2) in young and older adults. Experiment 3 investigated whether response modality during the test phase would influence spatial source memory performance. Experiments 1 and 2 supported the hypothesis that pointing during encoding led to better source memory for picture locations than naming or observation only. Young adults outperformed older adults on the source memory but not the item memory task in both Experiments 1 and 2. In Experiments 1 and 2, participants manually responded in the test phase. Experiment 3 showed that if participants had to verbally respond in the test phase, the positive effect of pointing compared with naming during encoding disappeared. The results suggest that pointing at picture locations during encoding can enhance spatial source memory in both young and older adults, but only if the response modality is congruent in the test phase.

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.

Incentive Analysis for Clean Water Act Reauthorization: Point Source/Nonpoint Source Trading for Nutrient Discharge Reductions (1992)

EPA Pesticide Factsheets

Paper focuses on trading schemes in which regulated point sources are allowed to avoid upgrading their pollution control technology to meet water quality-based effluent limits if they pay for equivalent (or greater) reductions in nonpoint source pollution.

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...

40 CFR 414.90 - Applicability; description of the subcategory of direct discharge point sources that use end-of...

Code of Federal Regulations, 2010 CFR

2010-07-01

... ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Direct Discharge Point Sources That Use End-of-Pipe... subcategory of direct discharge point sources that use end-of-pipe biological treatment. 414.90 Section 414.90... that use end-of-pipe biological treatment. The provisions of this subpart are applicable to the process...

40 CFR Table 4 to Part 455 - BAT and NSPS Effluent Limitations for Priority Pollutants for Direct Discharge Point Sources That...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false BAT and NSPS Effluent Limitations for Priority Pollutants for Direct Discharge Point Sources That use End-of-Pipe Biological Treatment 4 Table 4... Limitations for Priority Pollutants for Direct Discharge Point Sources That use End-of-Pipe Biological...

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.

[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.

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.

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

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.

Searches for point sources in the Galactic Center region

NASA Astrophysics Data System (ADS)

di Mauro, Mattia; Fermi-LAT Collaboration

2017-01-01

Several groups have demonstrated the existence of an excess in the gamma-ray emission around the Galactic Center (GC) with respect to the predictions from a variety of Galactic Interstellar Emission Models (GIEMs) and point source catalogs. The origin of this excess, peaked at a few GeV, is still under debate. A possible interpretation is that it comes from a population of unresolved Millisecond Pulsars (MSPs) in the Galactic bulge. We investigate the detection of point sources in the GC region using new tools which the Fermi-LAT Collaboration is developing in the context of searches for Dark Matter (DM) signals. These new tools perform very fast scans iteratively testing for additional point sources at each of the pixels of the region of interest. We show also how to discriminate between point sources and structural residuals from the GIEM. We apply these methods to the GC region considering different GIEMs and testing the DM and MSPs intepretations for the GC excess. Additionally, we create a list of promising MSP candidates that could represent the brightest sources of a MSP bulge population.

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.

Recent updates in developing a statistical pseudo-dynamic source-modeling framework to capture the variability of earthquake rupture scenarios

NASA Astrophysics Data System (ADS)

Song, Seok Goo; Kwak, Sangmin; Lee, Kyungbook; Park, Donghee

2017-04-01

It is a critical element to predict the intensity and variability of strong ground motions in seismic hazard assessment. The characteristics and variability of earthquake rupture process may be a dominant factor in determining the intensity and variability of near-source strong ground motions. Song et al. (2014) demonstrated that the variability of earthquake rupture scenarios could be effectively quantified in the framework of 1-point and 2-point statistics of earthquake source parameters, constrained by rupture dynamics and past events. The developed pseudo-dynamic source modeling schemes were also validated against the recorded ground motion data of past events and empirical ground motion prediction equations (GMPEs) at the broadband platform (BBP) developed by the Southern California Earthquake Center (SCEC). Recently we improved the computational efficiency of the developed pseudo-dynamic source-modeling scheme by adopting the nonparametric co-regionalization algorithm, introduced and applied in geostatistics initially. We also investigated the effect of earthquake rupture process on near-source ground motion characteristics in the framework of 1-point and 2-point statistics, particularly focusing on the forward directivity region. Finally we will discuss whether the pseudo-dynamic source modeling can reproduce the variability (standard deviation) of empirical GMPEs and the efficiency of 1-point and 2-point statistics to address the variability of ground motions.

Point and Compact Hα Sources in the Interior of M33

NASA Astrophysics Data System (ADS)

Moody, J. Ward; Hintz, Eric G.; Joner, Michael D.; Roming, Peter W. A.; Hintz, Maureen L.

2017-12-01

A variety of interesting objects such as Wolf-Rayet stars, tight OB associations, planetary nebulae, X-ray binaries, etc., can be discovered as point or compact sources in Hα surveys. How these objects distribute through a galaxy sheds light on the galaxy star formation rate and history, mass distribution, and dynamics. The nearby galaxy M33 is an excellent place to study the distribution of Hα-bright point sources in a flocculant spiral galaxy. We have reprocessed an archived WIYN continuum-subtracted Hα image of the inner 6.‧5 × 6.‧5 of M33 and, employing both eye and machine searches, have tabulated sources with a flux greater than approximately 10-15 erg cm-2s-1. We have effectively recovered previously mapped H II regions and have identified 152 unresolved point sources and 122 marginally resolved compact sources, of which 39 have not been previously identified in any archive. An additional 99 Hα sources were found to have sufficient archival flux values to generate a Spectral Energy Distribution. Using the SED, flux values, Hα flux value, and compactness, we classified 67 of these sources.

[Estimation of nonpoint source pollutant loads and optimization of the best management practices (BMPs) in the Zhangweinan River basin].

PubMed

Xu, Hua-Shan; Xu, Zong-Xue; Liu, Pin

2013-03-01

One of the key techniques in establishing and implementing TMDL (total maximum daily load) is to utilize hydrological model to quantify non-point source pollutant loads, establish BMPs scenarios, reduce non-point source pollutant loads. Non-point source pollutant loads under different years (wet, normal and dry year) were estimated by using SWAT model in the Zhangweinan River basin, spatial distribution characteristics of non-point source pollutant loads were analyzed on the basis of the simulation result. During wet years, total nitrogen (TN) and total phosphorus (TP) accounted for 0.07% and 27.24% of the total non-point source pollutant loads, respectively. Spatially, agricultural and residential land with steep slope are the regions that contribute more non-point source pollutant loads in the basin. Compared to non-point source pollutant loads with those during the baseline period, 47 BMPs scenarios were set to simulate the reduction efficiency of different BMPs scenarios for 5 kinds of pollutants (organic nitrogen, organic phosphorus, nitrate nitrogen, dissolved phosphorus and mineral phosphorus) in 8 prior controlled subbasins. Constructing vegetation type ditch was optimized as the best measure to reduce TN and TP by comparing cost-effective relationship among different BMPs scenarios, and the costs of unit pollutant reduction are 16.11-151.28 yuan x kg(-1) for TN, and 100-862.77 yuan x kg(-1) for TP, which is the most cost-effective measure among the 47 BMPs scenarios. The results could provide a scientific basis and technical support for environmental protection and sustainable utilization of water resources in the Zhangweinan River basin.

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.

Skyshine at neutron energies less than or equal to 400 MeV

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

Alsmiller, A.G. Jr.; Barish, J.; Childs, R.L.

1980-10-01

The dose equivalent at an air-ground interface as a function of distance from an assumed azimuthally symmetric point source of neutrons can be calculated as a double integral. The integration is over the source strength as a function of energy and polar angle weighted by an importance function that depends on the source variables and on the distance from the source to the filed point. The neutron importance function for a source 15 m above the ground emitting only into the upper hemisphere has been calculated using the two-dimensional discrete ordinates code, DOT, and the first collision source code, GRTUNCL,more » in the adjoint mode. This importance function is presented for neutron energies less than or equal to 400 MeV, for source cosine intervals of 1 to .8, .8 to .6 to .4, .4 to .2 and .2 to 0, and for various distances from the source to the field point. As part of the adjoint calculations a photon importance function is also obtained. This importance function for photon energies less than or equal to 14 MEV and for various source cosine intervals and source-to-field point distances is also presented. These importance functions may be used to obtain skyshine dose equivalent estimates for any known source energy-angle distribution.« less

Outlier Resistant Predictive Source Encoding for a Gaussian Stationary Nominal Source.

DTIC Science & Technology

1987-09-18

breakdown point and influence function . The proposed sequence of predictive encoders attains strictly positive breakdown point and uniformly bounded... influence function , at the expense of increased mean difference-squared distortion and differential entropy, at the Gaussian nominal source.

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.

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

Chandra Observations of the M31

NASA Technical Reports Server (NTRS)

Garcia, Michael; Lavoie, Anthony R. (Technical Monitor)

2000-01-01

We report on Chandra observations of the nearest Spiral Galaxy, M3l, The nuclear source seen with previous X-ray observatories is resolved into five point sources. One of these sources is within 1 arc-sec of the M31 central super-massive black hole. As compared to the other point sources in M3l. this nuclear source has an unusually soft spectrum. Based on the spatial coincidence and the unusual spectrum. we identify this source with the central black hole. A bright transient is detected 26 arc-sec to the west of the nucleus, which may be associated with a stellar mass black hole. We will report on a comparison of the x-ray spectrum of the diffuse emission and point sources seen in the central few arcmin

Waveform inversion of volcano-seismic signals for an extended source

USGS Publications Warehouse

Nakano, M.; Kumagai, H.; Chouet, B.; Dawson, P.

2007-01-01

We propose a method to investigate the dimensions and oscillation characteristics of the source of volcano-seismic signals based on waveform inversion for an extended source. An extended source is realized by a set of point sources distributed on a grid surrounding the centroid of the source in accordance with the source geometry and orientation. The source-time functions for all point sources are estimated simultaneously by waveform inversion carried out in the frequency domain. We apply a smoothing constraint to suppress short-scale noisy fluctuations of source-time functions between adjacent sources. The strength of the smoothing constraint we select is that which minimizes the Akaike Bayesian Information Criterion (ABIC). We perform a series of numerical tests to investigate the capability of our method to recover the dimensions of the source and reconstruct its oscillation characteristics. First, we use synthesized waveforms radiated by a kinematic source model that mimics the radiation from an oscillating crack. Our results demonstrate almost complete recovery of the input source dimensions and source-time function of each point source, but also point to a weaker resolution of the higher modes of crack oscillation. Second, we use synthetic waveforms generated by the acoustic resonance of a fluid-filled crack, and consider two sets of waveforms dominated by the modes with wavelengths 2L/3 and 2W/3, or L and 2L/5, where W and L are the crack width and length, respectively. Results from these tests indicate that the oscillating signature of the 2L/3 and 2W/3 modes are successfully reconstructed. The oscillating signature of the L mode is also well recovered, in contrast to results obtained for a point source for which the moment tensor description is inadequate. However, the oscillating signature of the 2L/5 mode is poorly recovered owing to weaker resolution of short-scale crack wall motions. The triggering excitations of the oscillating cracks are successfully reconstructed. Copyright 2007 by the American Geophysical Union.

Distributed optimization system and method

DOEpatents

Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

2003-06-10

A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

Distributed Optimization System

DOEpatents

Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

2004-11-30

A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

Analysis of point source size on measurement accuracy of lateral point-spread function of confocal Raman microscopy

NASA Astrophysics Data System (ADS)

Fu, Shihang; Zhang, Li; Hu, Yao; Ding, Xiang

2018-01-01

Confocal Raman Microscopy (CRM) has matured to become one of the most powerful instruments in analytical science because of its molecular sensitivity and high spatial resolution. Compared with conventional Raman Microscopy, CRM can perform three dimensions mapping of tiny samples and has the advantage of high spatial resolution thanking to the unique pinhole. With the wide application of the instrument, there is a growing requirement for the evaluation of the imaging performance of the system. Point-spread function (PSF) is an important approach to the evaluation of imaging capability of an optical instrument. Among a variety of measurement methods of PSF, the point source method has been widely used because it is easy to operate and the measurement results are approximate to the true PSF. In the point source method, the point source size has a significant impact on the final measurement accuracy. In this paper, the influence of the point source sizes on the measurement accuracy of PSF is analyzed and verified experimentally. A theoretical model of the lateral PSF for CRM is established and the effect of point source size on full-width at half maximum of lateral PSF is simulated. For long-term preservation and measurement convenience, PSF measurement phantom using polydimethylsiloxane resin, doped with different sizes of polystyrene microspheres is designed. The PSF of CRM with different sizes of microspheres are measured and the results are compared with the simulation results. The results provide a guide for measuring the PSF of the CRM.

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...

BACTERIA SOURCE TRACKING AND HOST SPECIES SPECIFICITY ANALYSIS

EPA Science Inventory

Point and non-point pollution sources of fecal pollution on a watershed adversely impact the quality of drinking source waters and recreational waters. States are required to develop total maximum daily loads (TMDLs) and devise best management practices (BMPs) to reduce the pollu...

Modeling the contribution of point sources and non-point sources to Thachin River water pollution.

PubMed

Schaffner, Monika; Bader, Hans-Peter; Scheidegger, Ruth

2009-08-15

Major rivers in developing and emerging countries suffer increasingly of severe degradation of water quality. The current study uses a mathematical Material Flow Analysis (MMFA) as a complementary approach to address the degradation of river water quality due to nutrient pollution in the Thachin River Basin in Central Thailand. This paper gives an overview of the origins and flow paths of the various point- and non-point pollution sources in the Thachin River Basin (in terms of nitrogen and phosphorus) and quantifies their relative importance within the system. The key parameters influencing the main nutrient flows are determined and possible mitigation measures discussed. The results show that aquaculture (as a point source) and rice farming (as a non-point source) are the key nutrient sources in the Thachin River Basin. Other point sources such as pig farms, households and industries, which were previously cited as the most relevant pollution sources in terms of organic pollution, play less significant roles in comparison. This order of importance shifts when considering the model results for the provincial level. Crosschecks with secondary data and field studies confirm the plausibility of our simulations. Specific nutrient loads for the pollution sources are derived; these can be used for a first broad quantification of nutrient pollution in comparable river basins. Based on an identification of the sensitive model parameters, possible mitigation scenarios are determined and their potential to reduce the nutrient load evaluated. A comparison of simulated nutrient loads with measured nutrient concentrations shows that nutrient retention in the river system may be significant. Sedimentation in the slow flowing surface water network as well as nitrogen emission to the air from the warm oxygen deficient waters are certainly partly responsible, but also wetlands along the river banks could play an important role as nutrient sinks.

Super-Resolution Imagery by Frequency Sweeping.

DTIC Science & Technology

1980-08-15

IMAGE RETRIEVAL The above considerations of multiwavelength holography have lead us to determining a means by which the 3-D Fourier space of the...it at a distant bright point source. The point source used need not be derived from a laser. In fact it is preferable for safety purposes to use an LED ...noise and therefore higher reconstructed image quality can be attained by using nonlaser point sources in the reconstruction such as LED or miniature

The VLITE Post-Processing Pipeline

NASA Astrophysics Data System (ADS)

Richards, Emily E.; Clarke, Tracy; Peters, Wendy; Polisensky, Emil; Kassim, Namir E.

2018-01-01

A post-processing pipeline to adaptively extract and catalog point sources is being developed to enhance the scientific value and accessibility of data products generated by the VLA Low-band Ionosphere and Transient Experiment (VLITE; ) on the Karl G. Jansky Very Large Array (VLA). In contrast to other radio sky surveys, the commensal observing mode of VLITE results in varying depths, sensitivities, and spatial resolutions across the sky based on the configuration of the VLA, location on the sky, and time on source specified by the primary observer for their independent science objectives. Therefore, previously developed tools and methods for generating source catalogs and survey statistics are not always appropriate for VLITE's diverse and growing set of data. A raw catalog of point sources extracted from every VLITE image will be created from source fit parameters stored in a queryable database. Point sources will be measured using the Python Blob Detector and Source Finder software (PyBDSF; Mohan & Rafferty 2015). Sources in the raw catalog will be associated with previous VLITE detections in a resolution- and sensitivity-dependent manner, and cross-matched to other radio sky surveys to aid in the detection of transient and variable sources. Final data products will include separate, tiered point source catalogs grouped by sensitivity limit and spatial resolution.

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.

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.

DNA BASED MOLECULAR METHODS FOR BACTERIAL SOURCE TRACKING IN WATERSHEDS

EPA Science Inventory

Point and non-point pollution sources of fecal pollution on a watershed adversely impact the quality of drinking source waters and recreational waters. States are required to develop total maximum daily loads (TMDLs) and devise best management practices (BMPs) to reduce the po...

AIR TOXICS ASSESSMENT REFINEMENT IN RAPCA'S JURISDICTION - DAYTON, OH AREA

EPA Science Inventory

RAPCA has receive two grants to conduct this project. As part of the original project, RAPCA has improved and expanded their point source inventory by converting the following area sources to point sources: dry cleaners, gasoline throughput processes and halogenated solvent clea...

Investigation of the Statistics of Pure Tone Sound Power Injection from Low Frequency, Finite Sized Sources in a Reverberant Room

NASA Technical Reports Server (NTRS)

Smith, Wayne Farrior

1973-01-01

The effect of finite source size on the power statistics in a reverberant room for pure tone excitation was investigated. Theoretical results indicate that the standard deviation of low frequency, pure tone finite sources is always less than that predicted by point source theory and considerably less when the source dimension approaches one-half an acoustic wavelength or greater. A supporting experimental study was conducted utilizing an eight inch loudspeaker and a 30 inch loudspeaker at eleven source positions. The resulting standard deviation of sound power output of the smaller speaker is in excellent agreement with both the derived finite source theory and existing point source theory, if the theoretical data is adjusted to account for experimental incomplete spatial averaging. However, the standard deviation of sound power output of the larger speaker is measurably lower than point source theory indicates, but is in good agreement with the finite source theory.

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.

Extending the Search for Neutrino Point Sources with IceCube above the Horizon

NASA Astrophysics Data System (ADS)

Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Alba, J. L. Bazo; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bissok, M.; Blaufuss, E.; Boersma, D. J.; Bohm, C.; Botner, O.; Bradley, L.; Braun, J.; Breder, D.; Carson, M.; Castermans, T.; Chirkin, D.; Christy, B.; Clem, J.; Cohen, S.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; Day, C. T.; de Clercq, C.; Demirörs, L.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; Deyoung, T.; Díaz-Vélez, J. C.; Dreyer, J.; Dumm, J. P.; Duvoort, M. R.; Edwards, W. R.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Feusels, T.; Filimonov, K.; Finley, C.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Ganugapati, R.; Gerhardt, L.; Gladstone, L.; Goldschmidt, A.; Goodman, J. A.; Gozzini, R.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gunasingha, R. M.; Gurtner, M.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Hasegawa, Y.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Homeier, A.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Imlay, R. L.; Inaba, M.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kelley, J. L.; Kemming, N.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Knops, S.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Krings, T.; Kroll, G.; Kuehn, K.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Lauer, R.; Lehmann, R.; Lennarz, D.; Lundberg, J.; Lünemann, J.; Madsen, J.; Majumdar, P.; Maruyama, R.; Mase, K.; Matis, H. S.; McParland, C. P.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Middell, E.; Milke, N.; Miyamoto, H.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; Ono, M.; Panknin, S.; Patton, S.; Paul, L.; de Los Heros, C. Pérez; Petrovic, J.; Piegsa, A.; Pieloth, D.; Pohl, A. C.; Porrata, R.; Potthoff, N.; Price, P. B.; Prikockis, M.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Roucelle, C.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Sarkar, S.; Schatto, K.; Schlenstedt, S.; Schmidt, T.; Schneider, D.; Schukraft, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stoufer, M. C.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Sullivan, G. W.; Swillens, Q.; Taboada, I.; Tamburro, A.; Tarasova, O.; Tepe, A.; Ter-Antonyan, S.; Terranova, C.; Tilav, S.; Toale, P. A.; Tooker, J.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; van Overloop, A.; van Santen, J.; Voigt, B.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Wiedemann, A.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Xu, C.; Xu, X. W.; Yodh, G.; Yoshida, S.

2009-11-01

Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies.

Current Source Logic Gate

NASA Technical Reports Server (NTRS)

Krasowski, Michael J. (Inventor); Prokop, Norman F. (Inventor)

2017-01-01

A current source logic gate with depletion mode field effect transistor ("FET") transistors and resistors may include a current source, a current steering switch input stage, and a resistor divider level shifting output stage. The current source may include a transistor and a current source resistor. The current steering switch input stage may include a transistor to steer current to set an output stage bias point depending on an input logic signal state. The resistor divider level shifting output stage may include a first resistor and a second resistor to set the output stage point and produce valid output logic signal states. The transistor of the current steering switch input stage may function as a switch to provide at least two operating points.

40 CFR 428.96 - Pretreatment standards for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUIDELINES AND STANDARDS RUBBER MANUFACTURING POINT SOURCE CATEGORY Pan, Dry Digestion, and Mechanical... pollutant properties, controlled by this section, which may be discharged to a publicly owned treatment works by a new point source subject to the provisions of this subpart: Pollutant or pollutant property...

FECAL BACTERIA SOURCE TRACKING AND BACTEROIDES SPP. HOST SPECIES SPECIFICITY ANALYSIS

EPA Science Inventory

Point and non-point pollution sources of fecal pollution on a watershed adversely impact the quality of drinking source waters and recreational waters. States are required to develop total maximum daily loads (TMDLs) and devise best management practices (BMPs) to reduce the po...

Coronal bright points at 6cm wavelength

NASA Technical Reports Server (NTRS)

Fu, Qijun; Kundu, M. R.; Schmahl, E. J.

1988-01-01

Results are presented from observations of bright points at a wavelength of 6-cm using the VLA with a spatial resolution of 1.2 arcsec. During two hours of observations, 44 sources were detected with brightness temperatures between 2000 and 30,000 K. Of these sources, 27 are associated with weak dark He 10830 A features at distances less than 40 arcsecs. Consideration is given to variations in the source parameters and the relationship between ephemeral regions and bright points.

Innovations in the Analysis of Chandra-ACIS Observations

NASA Astrophysics Data System (ADS)

Broos, Patrick S.; Townsley, Leisa K.; Feigelson, Eric D.; Getman, Konstantin V.; Bauer, Franz E.; Garmire, Gordon P.

2010-05-01

As members of the instrument team for the Advanced CCD Imaging Spectrometer (ACIS) on NASA's Chandra X-ray Observatory and as Chandra General Observers, we have developed a wide variety of data analysis methods that we believe are useful to the Chandra community, and have constructed a significant body of publicly available software (the ACIS Extract package) addressing important ACIS data and science analysis tasks. This paper seeks to describe these data analysis methods for two purposes: to document the data analysis work performed in our own science projects and to help other ACIS observers judge whether these methods may be useful in their own projects (regardless of what tools and procedures they choose to implement those methods). The ACIS data analysis recommendations we offer here address much of the workflow in a typical ACIS project, including data preparation, point source detection via both wavelet decomposition and image reconstruction, masking point sources, identification of diffuse structures, event extraction for both point and diffuse sources, merging extractions from multiple observations, nonparametric broadband photometry, analysis of low-count spectra, and automation of these tasks. Many of the innovations presented here arise from several, often interwoven, complications that are found in many Chandra projects: large numbers of point sources (hundreds to several thousand), faint point sources, misaligned multiple observations of an astronomical field, point source crowding, and scientifically relevant diffuse emission.

Magma transport and storage at Kilauea volcano, Hawaii I: 1790-1952

NASA Astrophysics Data System (ADS)

Wright, T. L.; Klein, F.

2011-12-01

We trace the evolution of Kilauea from the time of the first oral records of an explosive eruption in 1790 to the long eruption in Halemaumau crater in 1952. The establishment of modern seismic and geodetic networks in the early 1960s showed that eruptions and intrusions were fed from two magma sources beneath the summit at depths of 2-6 and ~1 km respectively (sources 1 and 2), and that seaward spreading of the south flank took place on a decollement at 10-12 km depth at the base of the Kilauea edifice. A third diffuse, pressure-transmitting magma system (source 3) between the shallow East rift zone and the decollement was also identified. We test the null hypothesis that the volcano has behaved similarly throughout its lifetime, and conclude that the null hypothesis is not met for the period preceding the 1952 summit eruption because of changes in magma supply rate and differences in ground deformation patterns. The western missionaries arriving at Kilauea in 1823 were confronted with a caldera-wide lava lake. Filling rates determined by visual observation correspond to magma supply rates that averaged more than 0.3 km3/yr prior to 1840 and declined to 1894, when lava disappeared altogether at Halemaumau crater. The Hawaiian Volcano Observatory (HVO) was established by Thomas A. Jaggar in 1912 adjacent to the Volcano House Hotel on the rim of Kilauea. Instrumental observation at HVO began using a seismometer that doubled as a tiltmeter. A 1912-1924 magma supply rate of 0.024 km3/yr agreed with the rate of filling of Kilauea caldera from 1840-1894. 1924 was a critical year. An intrusion that moved down Kilauea's East rift zone beginning in February culminated beneath the lower East rift zone in April. In May, explosive eruptions accompanied a dramatic draining of Halemaumau. Triangulation results between 1912 and 1921 showed uplift extending far beyond Kilauea caldera and an equally large regional subsidence occurred between 1921 and 1927. HVO tilt narrows the former time to 1918-1919 and the latter to 1924. Qualitative Mogi modeling of the 1921-1927 deformation data yields three centers, two shallow ones corresponding to sources 1 and 2, and a third deeper one that we interpret to represent draining of source 3. During recovery from the 1924 intrusion and collapse the tilt remained low, unlike the aftermath of more recent deflations. Small eruptions in Halemaumau between 1924 and 1934 used up the last of the magma that fed the lava lakes, and three passive East rift intrusions without a tilt signal are considered part of the recovery of source 3. Kilauea began inflating in March 1950, leading up to the long 1952 eruption in Halemaumau. Deep earthquakes occurred in 1950 and 1951, resulting in an increased magma supply rate of 0.062 km3/yr. An intense earthquake swarm occurred beneath the offshore south flank in March-April 1952 that unlocked the south flank to initiate the modern spreading regime. We interpret the 1924 intrusion as a critical event in stabilizing the modern magma system beneath the rift zone. Prior to that time it is probable that major caldera draining events in the 19th century involved the entire magmatic system. Measurements made at HVO are critical to the interpretations made in the pre-1952 period.

Tracking Nitrogen Sources, Transformation, and Transport at a Basin Scale with Complex Plain River Networks.

PubMed

Yi, Qitao; Chen, Qiuwen; Hu, Liuming; Shi, Wenqing

2017-05-16

This research developed an innovative approach to reveal nitrogen sources, transformation, and transport in large and complex river networks in the Taihu Lake basin using measurement of dual stable isotopes of nitrate. The spatial patterns of δ 15 N corresponded to the urbanization level, and the nitrogen cycle was associated with the hydrological regime at the basin level. During the high flow season of summer, nonpoint sources from fertilizer/soils and atmospheric deposition constituted the highest proportion of the total nitrogen load. The point sources from sewage/manure, with high ammonium concentrations and high δ 15 N and δ 18 O contents in the form of nitrate, accounted for the largest inputs among all sources during the low flow season of winter. Hot spot areas with heavy point source pollution were identified, and the pollutant transport routes were revealed. Nitrification occurred widely during the warm seasons, with decreased δ 18 O values; whereas great potential for denitrification existed during the low flow seasons of autumn and spring. The study showed that point source reduction could have effects over the short-term; however, long-term efforts to substantially control agriculture nonpoint sources are essential to eutrophication alleviation for the receiving lake, which clarifies the relationship between point and nonpoint source control.

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.

Parametric normalization for full-energy peak efficiency of HPGe γ-ray spectrometers at different counting positions for bulky sources.

PubMed

Peng, Nie; Bang-Fa, Ni; Wei-Zhi, Tian

2013-02-01

Application of effective interaction depth (EID) principle for parametric normalization of full energy peak efficiencies at different counting positions, originally for quasi-point sources, has been extended to bulky sources (within ∅30 mm×40 mm) with arbitrary matrices. It is also proved that the EID function for quasi-point source can be directly used for cylindrical bulky sources (within ∅30 mm×40 mm) with the geometric center as effective point source for low atomic number (Z) and low density (D) media and high energy γ-rays. It is also found that in general EID for bulky sources is dependent upon Z and D of the medium and the energy of the γ-rays in question. In addition, the EID principle was theoretically verified by MCNP calculations. Copyright © 2012 Elsevier Ltd. All rights reserved.

MacBurn's cylinder test problem

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

Shestakov, Aleksei I.

2016-02-29

This note describes test problem for MacBurn which illustrates its performance. The source is centered inside a cylinder with axial-extent-to-radius ratio s.t. each end receives 1/4 of the thermal energy. The source (fireball) is modeled as either a point or as disk of finite radius, as described by Marrs et al. For the latter, the disk is divided into 13 equal area segments, each approximated as a point source and models a partially occluded fireball. If the source is modeled as a single point, one obtains very nearly the expected deposition, e.g., 1/4 of the flux on each end andmore » energy is conserved. If the source is modeled as a disk, both conservation and energy fraction degrade. However, errors decrease if the source radius to domain size ratio decreases. Modeling the source as a disk increases run-times.« less

HerMES: point source catalogues from Herschel-SPIRE observations II

NASA Astrophysics Data System (ADS)

Wang, L.; Viero, M.; Clarke, C.; Bock, J.; Buat, V.; Conley, A.; Farrah, D.; Guo, K.; Heinis, S.; Magdis, G.; Marchetti, L.; Marsden, G.; Norberg, P.; Oliver, S. J.; Page, M. J.; Roehlly, Y.; Roseboom, I. G.; Schulz, B.; Smith, A. J.; Vaccari, M.; Zemcov, M.

2014-11-01

The Herschel Multi-tiered Extragalactic Survey (HerMES) is the largest Guaranteed Time Key Programme on the Herschel Space Observatory. With a wedding cake survey strategy, it consists of nested fields with varying depth and area totalling ˜380 deg2. In this paper, we present deep point source catalogues extracted from Herschel-Spectral and Photometric Imaging Receiver (SPIRE) observations of all HerMES fields, except for the later addition of the 270 deg2 HerMES Large-Mode Survey (HeLMS) field. These catalogues constitute the second Data Release (DR2) made in 2013 October. A sub-set of these catalogues, which consists of bright sources extracted from Herschel-SPIRE observations completed by 2010 May 1 (covering ˜74 deg2) were released earlier in the first extensive data release in 2012 March. Two different methods are used to generate the point source catalogues, the SUSSEXTRACTOR point source extractor used in two earlier data releases (EDR and EDR2) and a new source detection and photometry method. The latter combines an iterative source detection algorithm, STARFINDER, and a De-blended SPIRE Photometry algorithm. We use end-to-end Herschel-SPIRE simulations with realistic number counts and clustering properties to characterize basic properties of the point source catalogues, such as the completeness, reliability, photometric and positional accuracy. Over 500 000 catalogue entries in HerMES fields (except HeLMS) are released to the public through the HeDAM (Herschel Database in Marseille) website (http://hedam.lam.fr/HerMES).

Adaptive CT scanning system

DOEpatents

Sampayan, Stephen E.

2016-11-22

Apparatus, systems, and methods that provide an X-ray interrogation system having a plurality of stationary X-ray point sources arranged to substantially encircle an area or space to be interrogated. A plurality of stationary detectors are arranged to substantially encircle the area or space to be interrogated, A controller is adapted to control the stationary X-ray point sources to emit X-rays one at a time, and to control the stationary detectors to detect the X-rays emitted by the stationary X-ray point sources.

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...

Temperature Effects of Point Sources, Riparian Shading, and Dam Operations on the Willamette River, Oregon

USGS Publications Warehouse

Rounds, Stewart A.

2007-01-01

Water temperature is an important factor influencing the migration, rearing, and spawning of several important fish species in rivers of the Pacific Northwest. To protect these fish populations and to fulfill its responsibilities under the Federal Clean Water Act, the Oregon Department of Environmental Quality set a water temperature Total Maximum Daily Load (TMDL) in 2006 for the Willamette River and the lower reaches of its largest tributaries in northwestern Oregon. As a result, the thermal discharges of the largest point sources of heat to the Willamette River now are limited at certain times of the year, riparian vegetation has been targeted for restoration, and upstream dams are recognized as important influences on downstream temperatures. Many of the prescribed point-source heat-load allocations are sufficiently restrictive that management agencies may need to expend considerable resources to meet those allocations. Trading heat allocations among point-source dischargers may be a more economical and efficient means of meeting the cumulative point-source temperature limits set by the TMDL. The cumulative nature of these limits, however, precludes simple one-to-one trades of heat from one point source to another; a more detailed spatial analysis is needed. In this investigation, the flow and temperature models that formed the basis of the Willamette temperature TMDL were used to determine a spatially indexed 'heating signature' for each of the modeled point sources, and those signatures then were combined into a user-friendly, spreadsheet-based screening tool. The Willamette River Point-Source Heat-Trading Tool allows the user to increase or decrease the heating signature of each source and thereby evaluate the effects of a wide range of potential point-source heat trades. The predictions of the Trading Tool were verified by running the Willamette flow and temperature models under four different trading scenarios, and the predictions typically were accurate to within about 0.005 degrees Celsius (?C). In addition to assessing the effects of point-source heat trades, the models were used to evaluate the temperature effects of several shade-restoration scenarios. Restoration of riparian shade along the entire Long Tom River, from its mouth to Fern Ridge Dam, was calculated to have a small but significant effect on daily maximum temperatures in the main-stem Willamette River, on the order of 0.03?C where the Long Tom River enters the Willamette River, and diminishing downstream. Model scenarios also were run to assess the effects of restoring selected 5-mile reaches of riparian vegetation along the main-stem Willamette River from river mile (RM) 176.80, just upstream of the point where the McKenzie River joins the Willamette River, to RM 116.87 near Albany, which is one location where cumulative point-source heating effects are at a maximum. Restoration of riparian vegetation along the main-stem Willamette River was shown by model runs to have a significant local effect on daily maximum river temperatures (0.046 to 0.194?C) at the site of restoration. The magnitude of the cooling depends on many factors including river width, flow, time of year, and the difference in vegetation characteristics between current and restored conditions. Downstream of the restored reach, the cooling effects are complex and have a nodal nature: at one-half day of travel time downstream, shade restoration has little effect on daily maximum temperature because water passes the restoration site at night; at 1 full day of travel time downstream, cooling effects increase to a second, diminished maximum. Such spatial complexities may complicate the trading of heat allocations between point and nonpoint sources. Upstream dams have an important effect on water temperature in the Willamette River system as a result of augmented flows as well as modified temperature releases over the course of the summer and autumn. The TMDL was formulated prior t

Characterisation of a resolution enhancing image inversion interferometer.

PubMed

Wicker, Kai; Sindbert, Simon; Heintzmann, Rainer

2009-08-31

Image inversion interferometers have the potential to significantly enhance the lateral resolution and light efficiency of scanning fluorescence microscopes. Self-interference of a point source's coherent point spread function with its inverted copy leads to a reduction in the integrated signal for off-axis sources compared to sources on the inversion axis. This can be used to enhance the resolution in a confocal laser scanning microscope. We present a simple image inversion interferometer relying solely on reflections off planar surfaces. Measurements of the detection point spread function for several types of light sources confirm the predicted performance and suggest its usability for scanning confocal fluorescence microscopy.

Performance summary on a high power dense plasma focus x-ray lithography point source producing 70 nm line features in AlGaAs microcircuits

NASA Astrophysics Data System (ADS)

Petr, Rodney; Bykanov, Alexander; Freshman, Jay; Reilly, Dennis; Mangano, Joseph; Roche, Maureen; Dickenson, Jason; Burte, Mitchell; Heaton, John

2004-08-01

A high average power dense plasma focus (DPF), x-ray point source has been used to produce ˜70 nm line features in AlGaAs-based monolithic millimeter-wave integrated circuits (MMICs). The DPF source has produced up to 12 J per pulse of x-ray energy into 4π steradians at ˜1 keV effective wavelength in ˜2 Torr neon at pulse repetition rates up to 60 Hz, with an effective x-ray yield efficiency of ˜0.8%. Plasma temperature and electron concentration are estimated from the x-ray spectrum to be ˜170 eV and ˜5.1019 cm-3, respectively. The x-ray point source utilizes solid-state pulse power technology to extend the operating lifetime of electrodes and insulators in the DPF discharge. By eliminating current reversals in the DPF head, an anode electrode has demonstrated a lifetime of more than 5 million shots. The x-ray point source has also been operated continuously for 8 h run times at 27 Hz average pulse recurrent frequency. Measurements of shock waves produced by the plasma discharge indicate that overpressure pulses must be attenuated before a collimator can be integrated with the DPF point source.

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

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.

Line-source simulation for shallow-seismic data. Part 2: full-waveform inversion—a synthetic 2-D case study

NASA Astrophysics Data System (ADS)

Schäfer, M.; Groos, L.; Forbriger, T.; Bohlen, T.

2014-09-01

Full-waveform inversion (FWI) of shallow-seismic surface waves is able to reconstruct lateral variations of subsurface elastic properties. Line-source simulation for point-source data is required when applying algorithms of 2-D adjoint FWI to recorded shallow-seismic field data. The equivalent line-source response for point-source data can be obtained by convolving the waveforms with √{t^{-1}} (t: traveltime), which produces a phase shift of π/4. Subsequently an amplitude correction must be applied. In this work we recommend to scale the seismograms with √{2 r v_ph} at small receiver offsets r, where vph is the phase velocity, and gradually shift to applying a √{t^{-1}} time-domain taper and scaling the waveforms with r√{2} for larger receiver offsets r. We call this the hybrid transformation which is adapted for direct body and Rayleigh waves and demonstrate its outstanding performance on a 2-D heterogeneous structure. The fit of the phases as well as the amplitudes for all shot locations and components (vertical and radial) is excellent with respect to the reference line-source data. An approach for 1-D media based on Fourier-Bessel integral transformation generates strong artefacts for waves produced by 2-D structures. The theoretical background for both approaches is presented in a companion contribution. In the current contribution we study their performance when applied to waves propagating in a significantly 2-D-heterogeneous structure. We calculate synthetic seismograms for 2-D structure for line sources as well as point sources. Line-source simulations obtained from the point-source seismograms through different approaches are then compared to the corresponding line-source reference waveforms. Although being derived by approximation the hybrid transformation performs excellently except for explicitly back-scattered waves. In reconstruction tests we further invert point-source synthetic seismograms by a 2-D FWI to subsurface structure and evaluate its ability to reproduce the original structural model in comparison to the inversion of line-source synthetic data. Even when applying no explicit correction to the point-source waveforms prior to inversion only moderate artefacts appear in the results. However, the overall performance is best in terms of model reproduction and ability to reproduce the original data in a 3-D simulation if inverted waveforms are obtained by the hybrid transformation.

First Near-infrared Imaging Polarimetry of Young Stellar Objects in the Circinus Molecular Cloud

NASA Astrophysics Data System (ADS)

Kwon, Jungmi; Nakagawa, Takao; Tamura, Motohide; Hough, James H.; Choi, Minho; Kandori, Ryo; Nagata, Tetsuya; Kang, Miju

2018-02-01

We present the results of near-infrared (NIR) linear imaging polarimetry in the J, H, and K s bands of the low-mass star cluster-forming region in the Circinus Molecular Cloud Complex. Using aperture polarimetry of point-like sources, positive detection of 314, 421, and 164 sources in the J, H, and K s bands, respectively, was determined from among 749 sources whose photometric magnitudes were measured. For the source classification of the 133 point-like sources whose polarization could be measured in all 3 bands, a color–color diagram was used. While most of the NIR polarizations of point-like sources are well-aligned and can be explained by dichroic polarization produced by aligned interstellar dust grains in the cloud, 123 highly polarized sources have also been identified with some criteria. The projected direction on the sky of the magnetic field in the Cir-MMS region is indicated by the mean polarization position angles (70°) of the point-like sources in the observed region, corresponding to approximately 1.6× 1.6 pc2. In addition, the magnetic field direction is compared with the outflow orientations associated with Infrared Astronomy Satellite sources, in which two sources were found to be aligned with each other and one source was not. We also show prominent polarization nebulosities over the Cir-MMS region for the first time. Our polarization data have revealed one clear infrared reflection nebula (IRN) and several candidate IRNe in the Cir-MMS field. In addition, the illuminating sources of the IRNe are identified with near- and mid-infrared sources.

Real-time monitoring and massive inversion of source parameters of very long period seismic signals: An application to Stromboli Volcano, Italy

USGS Publications Warehouse

Auger, E.; D'Auria, L.; Martini, M.; Chouet, B.; Dawson, P.

2006-01-01

We present a comprehensive processing tool for the real-time analysis of the source mechanism of very long period (VLP) seismic data based on waveform inversions performed in the frequency domain for a point source. A search for the source providing the best-fitting solution is conducted over a three-dimensional grid of assumed source locations, in which the Green's functions associated with each point source are calculated by finite differences using the reciprocal relation between source and receiver. Tests performed on 62 nodes of a Linux cluster indicate that the waveform inversion and search for the best-fitting signal over 100,000 point sources require roughly 30 s of processing time for a 2-min-long record. The procedure is applied to post-processing of a data archive and to continuous automatic inversion of real-time data at Stromboli, providing insights into different modes of degassing at this volcano. Copyright 2006 by the American Geophysical Union.

A spatial and seasonal assessment of river water chemistry across North West England.

PubMed

Rothwell, J J; Dise, N B; Taylor, K G; Allott, T E H; Scholefield, P; Davies, H; Neal, C

2010-01-15

This paper presents information on the spatial and seasonal patterns of river water chemistry at approximately 800 sites in North West England based on data from the Environment Agency regional monitoring programme. Within a GIS framework, the linkages between average water chemistry (pH, sulphate, base cations, nutrients and metals) catchment characteristics (topography, land cover, soil hydrology, base flow index and geology), rainfall, deposition chemistry and geo-spatial information on discharge consents (point sources) are examined. Water quality maps reveal that there is a clear distinction between the uplands and lowlands. Upland waters are acidic and have low concentrations of base cations, explained by background geological sources and land cover. Localised high concentrations of metals occur in areas of the Cumbrian Fells which are subjected to mining effluent inputs. Nutrient concentrations are low in the uplands with the exception sites receiving effluent inputs from rural point sources. In the lowlands, both past and present human activities have a major impact on river water chemistry, especially in the urban and industrial heartlands of Greater Manchester, south Lancashire and Merseyside. Over 40% of the sites have average orthophosphate concentrations >0.1mg-Pl(-1). Results suggest that the dominant control on orthophosphate concentrations is point source contributions from sewage effluent inputs. Diffuse agricultural sources are also important, although this influence is masked by the impact of point sources. Average nitrate concentrations are linked to the coverage of arable land, although sewage effluent inputs have a significant effect on nitrate concentrations. Metal concentrations in the lowlands are linked to diffuse and point sources. The study demonstrates that point sources, as well as diffuse sources, need to be considered when targeting measures for the effective reduction in river nutrient concentrations. This issue is clearly important with regards to the European Union Water Framework Directive, eutrophication and river water quality. Copyright 2009 Elsevier B.V. All rights reserved.

Sampling Singular and Aggregate Point Sources of Carbon Dioxide from Space Using OCO-2

NASA Astrophysics Data System (ADS)

Schwandner, F. M.; Gunson, M. R.; Eldering, A.; Miller, C. E.; Nguyen, H.; Osterman, G. B.; Taylor, T.; O'Dell, C.; Carn, S. A.; Kahn, B. H.; Verhulst, K. R.; Crisp, D.; Pieri, D. C.; Linick, J.; Yuen, K.; Sanchez, R. M.; Ashok, M.

2016-12-01

Anthropogenic carbon dioxide (CO2) sources increasingly tip the natural balance between natural carbon sources and sinks. Space-borne measurements offer opportunities to detect and analyze point source emission signals anywhere on Earth. Singular continuous point source plumes from power plants or volcanoes turbulently mix into their proximal background fields. In contrast, plumes of aggregate point sources such as cities, and transportation or fossil fuel distribution networks, mix into each other and may therefore result in broader and more persistent excess signals of total column averaged CO2 (XCO2). NASA's first satellite dedicated to atmospheric CO2observation, the Orbiting Carbon Observatory-2 (OCO-2), launched in July 2014 and now leads the afternoon constellation of satellites (A-Train). While continuously collecting measurements in eight footprints across a narrow ( < 10 km) wide swath it occasionally cross-cuts coincident emission plumes. For singular point sources like volcanoes and coal fired power plants, we have developed OCO-2 data discovery tools and a proxy detection method for plumes using SO2-sensitive TIR imaging data (ASTER). This approach offers a path toward automating plume detections with subsequent matching and mining of OCO-2 data. We found several distinct singular source CO2signals. For aggregate point sources, we investigated whether OCO-2's multi-sounding swath observing geometry can reveal intra-urban spatial emission structures in the observed variability of XCO2 data. OCO-2 data demonstrate that we can detect localized excess XCO2 signals of 2 to 6 ppm against suburban and rural backgrounds. Compared to single-shot GOSAT soundings which detected urban/rural XCO2differences in megacities (Kort et al., 2012), the OCO-2 swath geometry opens up the path to future capabilities enabling urban characterization of greenhouse gases using hundreds of soundings over a city at each satellite overpass. California Institute of Technology

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

The 2010-2011 Microearthquake Swarm in Krýsuvík, SW Iceland: Was it Triggered by Crustal Magma Injection?

NASA Astrophysics Data System (ADS)

Liu, J.; Michael, F.; Hager, B. H.

2013-12-01

Iceland, the on-land continuation of the Mid-Atlantic Ridge, is the result of the interaction between the Mid-Atlantic Ridge and the North-Atlantic mantle plume. The superposition and relative motion of the spreading plate boundary over the mantle plume are manifested by the volcanism and seismicity in Iceland. The Krýsuvík geothermal field is one of the most active geothermal fields in southwest Iceland. In 2010, Massachusetts Institute of Technology, Reykjanes University, Uppsala University, and the Iceland Geosurvey (ISOR) deployed 38 temporary seismic stations on the Reykjanes Peninsula. Using data from 18 of the temporary seismic stations and from 5 stations of the South Iceland Lowland network around Krýsuvík, we captured an earthquake swarm that occurred between November, 2010 and February, 2011. We applied double difference tomography to relocate the events and determine the velocity structure in the region. Activity is clustered around the center of the Krýsuvík volcano system. Our seismic tomography result indicates a low velocity zone at a depth of about 6 km, right under the earthquake swarm. We consider that this low velocity zone contains some crustal magma that may be the thermal source for the geothermal field. At the same time, our relocated events delineate faults above and around this magma chamber. The system is within the stress field of a combination of left-lateral shear and extension; the majority of the strike-slip faults are right-lateral and most dip-slip faults are normal faults. Published geodetic measurements for the time period between 2009 and 2012 show a few centimeters uplift and extension in the area of the seismic swarm. We modeled the observed deformation using the Coulomb 3.3 software (U.S. Geological Survey). Our result indicates that a Mogi source of about 20×10^6 m^3 at a depth of about 6 km, consistent with the location and size of the tomography result, can explain the main deformation. The normal and the right-lateral strike-slip faults that are delineated by the earthquake relocations, consistent with the local stress induced by magma intrusion and the regional stress field caused by the interaction of the spreading plate boundary and mantle plume, explain the observed second order deformation. Our results are consistent with the hypothesis that seismicity in the Krýsuvík area in 2010-2011 might be triggered by magmatic activity.

Point kernel calculations of skyshine exposure rates

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

Roseberry, M.L.; Shultis, J.K.

1982-02-01

A simple point kernel model is presented for the calculation of skyshine exposure rates arising from the atmospheric reflection of gamma radiation produced by a vertically collimated or a shielded point source. This model is shown to be in good agreement with benchmark experimental data from a /sup 60/Co source for distances out to 700 m.

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...

A deeper look at the X-ray point source population of NGC 4472

NASA Astrophysics Data System (ADS)

Joseph, T. D.; Maccarone, T. J.; Kraft, R. P.; Sivakoff, G. R.

2017-10-01

In this paper we discuss the X-ray point source population of NGC 4472, an elliptical galaxy in the Virgo cluster. We used recent deep Chandra data combined with archival Chandra data to obtain a 380 ks exposure time. We find 238 X-ray point sources within 3.7 arcmin of the galaxy centre, with a completeness flux, FX, 0.5-2 keV = 6.3 × 10-16 erg s-1 cm-2. Most of these sources are expected to be low-mass X-ray binaries. We finding that, using data from a single galaxy which is both complete and has a large number of objects (˜100) below 1038 erg s-1, the X-ray luminosity function is well fitted with a single power-law model. By cross matching our X-ray data with both space based and ground based optical data for NGC 4472, we find that 80 of the 238 sources are in globular clusters. We compare the red and blue globular cluster subpopulations and find red clusters are nearly six times more likely to host an X-ray source than blue clusters. We show that there is evidence that these two subpopulations have significantly different X-ray luminosity distributions. Source catalogues for all X-ray point sources, as well as any corresponding optical data for globular cluster sources, are also presented here.

Rio Grande valley Colorado new Mexico and Texas

USGS Publications Warehouse

Ellis, Sherman R.; Levings, Gary W.; Carter, Lisa F.; Richey, Steven F.; Radell, Mary Jo

1993-01-01

Two structural settings are found in the study unit: alluvial basins and bedrock basins. The alluvial basins can have through-flowing surface water or be closed basins. The discussion of streamflow and water quality for the surface-water system is based on four river reaches for the 750 miles of the main stem. the quality of the ground water is affected by both natural process and human activities and by nonpoint and point sources. Nonpoint sources for surface water include agriculture, hydromodification, and mining operations; point sources are mainly discharge from wastewater treatment plants. Nonpoint sources for ground water include agriculture and septic tanks and cesspools; point sources include leaking underground storage tanks, unlined or manure-lined holding ponds used for disposal of dairy wastes, landfills, and mining operations.

Spherical-earth Gravity and Magnetic Anomaly Modeling by Gauss-legendre Quadrature Integration

NASA Technical Reports Server (NTRS)

Vonfrese, R. R. B.; Hinze, W. J.; Braile, L. W.; Luca, A. J. (Principal Investigator)

1981-01-01

The anomalous potential of gravity and magnetic fields and their spatial derivatives on a spherical Earth for an arbitrary body represented by an equivalent point source distribution of gravity poles or magnetic dipoles were calculated. The distribution of equivalent point sources was determined directly from the coordinate limits of the source volume. Variable integration limits for an arbitrarily shaped body are derived from interpolation of points which approximate the body's surface envelope. The versatility of the method is enhanced by the ability to treat physical property variations within the source volume and to consider variable magnetic fields over the source and observation surface. A number of examples verify and illustrate the capabilities of the technique, including preliminary modeling of potential field signatures for Mississippi embayment crustal structure at satellite elevations.

Distinguishing the Effects of Local Point Sources from Those Caused by Upstream Nonpoint Source (NPS) Inputs: Refinement of a Watershed Development Index for New England

EPA Science Inventory

Using EMAP data from the NE Wadeable Stream Survey and state datasets (CT, ME), assessment tools were developed to predict diffuse NPS effects from watershed development and distinguish these from local impacts (point sources, contaminated sediments). Classification schemes were...

Distinguishing Betwen Effects of Local Inputs (Contaminated Sediments, Point Sources) and Upstream Diffuse Nonpoint Source Input: Refinement of a Watershed Development Index for New England

EPA Science Inventory

Assessment tools are being developed to predict diffuse NPS effects from watershed development and distinguish these from local impacts (point sources, contaminated sediments). Using EMAP data from the New England Wadeable Stream Survey and two state datasets (CT, ME), we are de...

Identifying and characterizing major emission point sources as a basis for geospatial distribution of mercury emissions inventories

NASA Astrophysics Data System (ADS)

Steenhuisen, Frits; Wilson, Simon J.

2015-07-01

Mercury is a global pollutant that poses threats to ecosystem and human health. Due to its global transport, mercury contamination is found in regions of the Earth that are remote from major emissions areas, including the Polar regions. Global anthropogenic emission inventories identify important sectors and industries responsible for emissions at a national level; however, to be useful for air transport modelling, more precise information on the locations of emission is required. This paper describes the methodology applied, and the results of work that was conducted to assign anthropogenic mercury emissions to point sources as part of geospatial mapping of the 2010 global anthropogenic mercury emissions inventory prepared by AMAP/UNEP. Major point-source emission sectors addressed in this work account for about 850 tonnes of the emissions included in the 2010 inventory. This work allocated more than 90% of these emissions to some 4600 identified point source locations, including significantly more point source locations in Africa, Asia, Australia and South America than had been identified during previous work to geospatially-distribute the 2005 global inventory. The results demonstrate the utility and the limitations of using existing, mainly public domain resources to accomplish this work. Assumptions necessary to make use of selected online resources are discussed, as are artefacts that can arise when these assumptions are applied to assign (national-sector) emissions estimates to point sources in various countries and regions. Notwithstanding the limitations of the available information, the value of this procedure over alternative methods commonly used to geo-spatially distribute emissions, such as use of 'proxy' datasets to represent emissions patterns, is illustrated. Improvements in information that would facilitate greater use of these methods in future work to assign emissions to point-sources are discussed. These include improvements to both national (geo-referenced) emission inventories and also to other resources that can be employed when such national inventories are lacking.

Searching for the Signature of Wastewater Injection in continuous GPS Data from The Geysers Geothermal Field

NASA Astrophysics Data System (ADS)

Terry, R. L.; Funning, G.; Floyd, M.

2017-12-01

The Geysers geothermal field in California, which provides a large portion of northern California's power, has seen declining steam pressures over the past three decades, accompanied by surface subsidence. Together, these two phenomena are likely the result of the exploitation of the reservoir without adequate time for natural restoration. To combat the decline in steam pressures, The Geysers began injecting imported wastewater into the geothermal reservoir in 1997 and expanded injection in 2003. In 2012 and 2013, we installed three continuously recording GPS stations in The Geysers to closely monitor crustal deformation due to both the extraction of steam and the injection of wastewater. To assess the impact of the current injection and extraction activities on the geothermal reservoir, we analyze the position time-series from these GPS stations alongside wastewater injection and steam extraction data. We use common-mode filtering to remove any regionally-correlated noise from our GPS time series, and also estimate and subtract any seasonal signals present. To predict the effect of injection and production on surface movement, we summed the monthly time series of well data within a rectangular grid framework. We then use an array of Mogi sources based on each grid cell's total volume change to calculate the expected surface deformation due to these volume changes at depth. The temporal resolution provided by GPS allows us to characterize more accurately the properties of the subsurface geothermal reservoir related to forcing. For example, based on a similar spatiotemporal relationship between injection and seismicity, we hypothesize that there may be a delayed deformation response following injection, related to the permeability of the reservoir, and are undertaking detailed comparisons between our time series data to identify this response. Overall changes in the sense and rate of vertical motion in the field due to injection over time are also expected. We anticipate that the impact of discovering a relationship between injection and surface deformation will be of great importance in maintaining and managing geothermal resources in the future.

Stability of volcanic conduits: insights from magma ascent modelling and possible consequences on eruptive dynamics

NASA Astrophysics Data System (ADS)

Aravena, Alvaro; de'Michieli Vitturi, Mattia; Cioni, Raffaello; Neri, Augusto

2017-04-01

Geological evidences of changes in volcanic conduit geometry (i.e. erosive processes) are common in the volcanic record, as revealed by the occurrence of lithic fragments in most pyroclastic deposits. However, the controlling factors of conduit enlargement mechanisms are still partially unclear, as well as the influence of conduit geometry in the eruptive dynamics. Despite physical models have been systematically used for studying volcanic conduits, their mechanical stability has been poorly addressed. In order to study the mechanical stability of volcanic conduits during explosive eruptions, we present a 1D steady-state model which considers the main processes experimented by ascending magmas, such as crystallization, drag forces, fragmentation, outgassing and degassing; and the application of the Mogi-Coulomb collapse criterion, using a set of constitutive equations for studying typical cases of rhyolitic and trachytic explosive volcanism. From our results emerge that conduit stability is mainly controlled by magma rheology and conduit dimensions. Indeed, in order to be stable, feeding conduits of rhyolitic eruptions need larger radii respect to their trachytic counterparts, which is manifested in the higher eruption rates usually observed in rhyolitic explosive eruptions, as confirmed by a small compilation of global data. Additionally, for both magma compositions, we estimated a minimum magma flux for developing stable conduits (˜3ṡ106 kg/s for trachytic magmas and ˜8ṡ107 kg/s for rhyolitic magmas), which is consistent with the unsteady character commonly observed in low-mass flux events (e.g. sub-Plinian eruptions), which would be produced by episodic collapse events of the volcanic conduit, opposite to the mainly stationary high-mass flux events (e.g. Plinian eruptions), characterized by stable conduits. For a given magma composition, a minimum radius for reaching stable conditions can be computed, as a function of inlet overpressure and water content. Under the assumption that magma chamber conditions during a typical volcanic eruption follow a depressurizing trend, a continuous conduit widening process is expected. This process could explain the pervasive and continuous presence of lithic fragments in most pyroclastic deposits, even with stationary properties and conditions of the magma source (e.g. water content, temperature, composition).

MANAGING MICROBIAL CONTAMINATION IN URBAN WATERSHEDS

EPA Science Inventory

This paper presents different approaches for controlling pathogen contamination in urban watersheds for contamination resulting from point and diffuse sources. Point sources of pathogens can be treated by a disinfection technology of known effectiveness, and a desired reduction ...

MANAGING MICROBIAL CONTAMINATION IN URBAN WATERSHEDS

EPA Science Inventory

This paper presents different approaches for controlling pathogen contamination in urban watersheds for contamination resulting from point and diffuses sources. Point sources of pathogens can be treated by a disinfection technology of known effectiveness, and a desired reduction ...

[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.

Spherical-earth gravity and magnetic anomaly modeling by Gauss-Legendre quadrature integration

NASA Technical Reports Server (NTRS)

Von Frese, R. R. B.; Hinze, W. J.; Braile, L. W.; Luca, A. J.

1981-01-01

Gauss-Legendre quadrature integration is used to calculate the anomalous potential of gravity and magnetic fields and their spatial derivatives on a spherical earth. The procedure involves representation of the anomalous source as a distribution of equivalent point gravity poles or point magnetic dipoles. The distribution of equivalent point sources is determined directly from the volume limits of the anomalous body. The variable limits of integration for an arbitrarily shaped body are obtained from interpolations performed on a set of body points which approximate the body's surface envelope. The versatility of the method is shown by its ability to treat physical property variations within the source volume as well as variable magnetic fields over the source and observation surface. Examples are provided which illustrate the capabilities of the technique, including a preliminary modeling of potential field signatures for the Mississippi embayment crustal structure at 450 km.

Genetic diversity and mating system of Copaifera langsdorffii (Leguminosae/Caesalpinioideae).

PubMed

Gonela, A; Sebbenn, A M; Soriani, H H; Mestriner, M A; Martinez, C A; Alzate-Marin, A L

2013-02-27

Copaifera langsdorffii, locally known as copaíba, is a valuable tropical tree with medicinal properties of its oil. We studied the genetic variation, genetic structure, and the mating system of trees in stands of C. langsdorffii (Leguminosae/Caesalpinioideae) located in an extensive area between the Pardo and Mogi-Guaçu basins in São Paulo State, Brazil, and their offspring, conserved in an ex situ germplasm bank at the University of São Paulo in Ribeirão Preto, SP, Brazil, using six microsatellite loci. Leaves were collected from 80 seed trees and from 259 offspring and their DNA extracted. A total of 140 and 175 alleles were found in the seed trees and their offspring, respectively. Low genetic differentiation was observed between stands, indicating intense gene flow due to efficient pollen dispersion vectors. An estimation of the outcrossing rate showed that these stands are outcrossed (tm = 0.98, P > 0.05). The mean variance of the effective population size of each family in two of the stands was 3.69 and 3.43, while the total effective population size retained in the germplasm bank was between 81 and 96. The paternity correlation was low, ranging from 0.052 to 0.148, demonstrating that the families implanted in this germplasm bank are composed predominantly of half-sibs.

[Factors related to the quality of life of the elderly in programs for senior citizens].

PubMed

Dawalibi, Nathaly Wehbe; Goulart, Rita Maria Monteiro; Prearo, Leandro Campi

2014-08-01

Population aging is a social phenomenon that demands the attention of health professionals. This article seeks to analyze the influence of possible intervening factors on the quality of life of the elderly. It was a cross-sectional, quantitative, descriptive and exploratory study, in which 182 elderly of both genders participated. They were aged ≥ 60 years and were enrolled in programs for senior citizens from three universities located in the cities of Sao Paulo, Sao Caetano do Sul and Mogi das Cruzes. To evaluate the subjective perception of quality of life, the World Health Organization Quality of Life questionnaire (WHOQOL-Bref) was used. Multiple linear regression analysis was performed on the dependent and independent variables. A significance level of 5% was adopted. The results showed that the absence of disease positively influenced the quality of life on the four domains evaluated. In the environmental domain, full tertiary education, old age, the absence of disease and being a resident in Sao Caetano do Sul positively influenced the quality of life of the elderly. The factors associated with better quality of life were: full tertiary education, old age, the absence of disease and being a resident in Sao Caetano do Sul, in that order of importance.

Pattern Informatics Approach to Earthquake Forecasting in 3D

NASA Astrophysics Data System (ADS)

Toya, Y.; Tiampo, K. F.; Rundle, J. B.; Chen, C.; Li, H.; Klein, W.

2009-05-01

Natural seismicity is correlated across multiple spatial and temporal scales, but correlations in seismicity prior to a large earthquake are locally subtle (e.g. seismic quiescence) and often prominent in broad scale (e.g., seismic activation), resulting in local and regional seismicity patterns, e.g. a Mogi's donut. Recognizing that patterns in seismicity rate are reflecting the regional dynamics of the directly unobservable crustal stresses, the Pattern Informatics (PI) approach was introduced by Tiampo et al. in 2002 [Europhys. Lett., 60 (3), 481-487,] Rundle et al., 2002 [PNAS 99, suppl. 1, 2514-2521.] In this study, we expand the PI approach to forecasting earthquakes into the third, or vertical dimension, and illustrate its further improvement in the forecasting performance through case studies of both natural and synthetic data. The PI characterizes rapidly evolving spatio-temporal seismicity patterns as angular drifts of a unit state vector in a high dimensional correlation space, and systematically identifies anomalous shifts in seismic activity with respect to the regional background. 3D PI analysis is particularly advantageous over 2D analysis in resolving vertically overlapped seismicity anomalies in a highly complex tectonic environment. Case studies will help to illustrate some important properties of the PI forecasting tool. [Submitted to: Concurrency and Computation: Practice and Experience, Wiley, Special Issue: ACES2008.

The Mohr-Coulomb criterion for intact rock strength and friction - a re-evaluation and consideration of failure under polyaxial stresses

NASA Astrophysics Data System (ADS)

Hackston, Abigail; Rutter, Ernest

2016-04-01

Darley Dale and Pennant sandstones were tested under conditions of both axisymmetric shortening and extension normal to bedding. These are the two extremes of loading under polyaxial stress conditions. Failure under generalized stress conditions can be predicted from the Mohr-Coulomb failure criterion under axisymmetric shortening conditions, provided the best form of polyaxial failure criterion is known. The sandstone data are best reconciled using the Mogi (1967) empirical criterion. Fault plane orientations produced vary greatly with respect to the maximum compressive stress direction in the two loading configurations. The normals to the Mohr-Coulomb failure envelopes do not predict the orientations of the fault planes eventually produced. Frictional sliding on variously inclined saw cuts and failure surfaces produced in intact rock samples was also investigated. Friction coefficient is not affected by fault plane orientation in a given loading configuration, but friction coefficients in extension were systematically lower than in compression for both rock types. Friction data for these and other porous sandstones accord well with the Byerlee (1978) generalization about rock friction being largely independent of rock type. For engineering and geodynamic modelling purposes, the stress-state-dependent friction coefficient should be used for sandstones, but it is not known to what extent this might apply to other rock types.

Gravity Changes and Internal Processes: Some Results Obtained from Observations at Three Volcanoes

NASA Astrophysics Data System (ADS)

Jentzsch, Gerhard; Weise, Adelheid; Rey, Carlos; Gerstenecker, Carl

Temporal gravity changes provide information about mass and/or density variations within and below the volcano edifice. Three active volcanoes have been under investigation; each of them related to a plate boundary: Mayon/Luzon/Philippines, Merapi/Java/Indonesia, and Galeras/Colombia. The observed gravity changes are smaller than previously expected but significant. For the three volcanoes under investigation, and within the observation period, mainly the increase of gravity is observed, ranging from 1,000 nm-2 to 1,600 nms-2. Unexpectedly, the gravity increase is confined to a rather small area with radii of 5 to 8 km around the summit. At Mayon and Merapi the parallel GPS measurements yield no significant elevation changes. This is crucial for the interpretation, as the internal pressure variations do not lead to significant deformation at the surface. Thus the classical Mogi-model for a shallow extending magma reservoir cannot apply. To confine the possible models, the attraction due to changes of groundwater level or soil moisture is estimated along the slope of Merapi exemplarily by 2-D modelling. Mass redistribution or density changes were evaluated within the vent as well as deeper fluid processes to explain the gravity variations; the results are compared to the model incorporating the additional effect of elastic deformation.

Nutrient and Suspended-Sediment Transport and Trends in the Columbia River and Puget Sound Basins, 1993-2003

USGS Publications Warehouse

Wise, Daniel R.; Rinella, Frank A.; Rinella, Joseph F.; Fuhrer, Greg J.; Embrey, Sandra S.; Clark, Gregory M.; Schwarz, Gregory E.; Sobieszczyk, Steven

2007-01-01

This study focused on three areas that might be of interest to water-quality managers in the Pacific Northwest: (1) annual loads of total nitrogen (TN), total phosphorus (TP) and suspended sediment (SS) transported through the Columbia River and Puget Sound Basins, (2) annual yields of TN, TP, and SS relative to differences in landscape and climatic conditions between subbasin catchments (drainage basins), and (3) trends in TN, TP, and SS concentrations and loads in comparison to changes in landscape and climatic conditions in the catchments. During water year 2000, an average streamflow year in the Pacific Northwest, the Columbia River discharged about 570,000 pounds per day of TN, about 55,000 pounds per day of TP, and about 14,000 tons per day of SS to the Pacific Ocean. The Snake, Yakima, Deschutes, and Willamette Rivers contributed most of the load discharged to the Columbia River. Point-source nutrient loads to the catchments (almost exclusively from municipal wastewater treatment plants) generally were a small percentage of the total in-stream nutrient loads; however, in some reaches of the Spokane, Boise, Walla Walla, and Willamette River Basins, point sources were responsible for much of the annual in-stream nutrient load. Point-source nutrient loads generally were a small percentage of the total catchment nutrient loads compared to nonpoint sources, except for a few catchments where point-source loads comprised as much as 30 percent of the TN load and as much as 80 percent of the TP load. The annual TN and TP loads from point sources discharging directly to the Puget Sound were about equal to the annual loads from eight major tributaries. Yields of TN, TP, and SS generally were greater in catchments west of the Cascade Range. A multiple linear regression analysis showed that TN yields were significantly (p < 0.05) and positively related to precipitation, atmospheric nitrogen load, fertilizer and manure load, and point-source load, and were negatively related to average slope. TP yields were significantly related positively to precipitation, and point-source load and SS yields were significantly related positively to precipitation. Forty-eight percent of the available monitoring sites for TN had significant trends in concentration (2 increasing, 19 decreasing), 32 percent of the available sites for TP had significant trends in concentration (7 increasing, 9 decreasing), and 40 percent of the available sites for SS had significant trends in concentration (4 increasing, 15 decreasing). The trends in load followed a similar pattern, but with fewer sites showing significant trends. The results from this study indicate that inputs from nonpoint sources of nutrients probably have decreased over time in many of the catchments. Despite the generally small contribution of point-source nutrient loads, they still may have been partially responsible for the significant decreasing trends for nutrients at sites where the total point-source nutrient loads to the catchments equaled a substantial proportion of the in-stream load.

Young and Old X-ray Binary and IXO Populations in Spiral and Elliptical Galaxies

NASA Astrophysics Data System (ADS)

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

2003-03-01

We have analyzed Chandra ACIS observations of 32 nearby spiral and elliptical galaxies and present the results of 1441 X-ray point sources, which are presumed to be mostly X-ray binaries (XRBs) and Intermediate-luminosity X-ray Objects (IXOs, a.k.a. ULXs). The X-ray luminosity functions (XLFs) of the point sources show that the slope of the elliptical galaxy XLFs are significantly steeper than the spiral galaxy XLFs, indicating grossly different types of point sources, or different stages in their evolution. Since the spiral galaxy XLF is so shallow, the most luminous points sources (usually the IXOs) dominate the total X-ray point source luminosity LXP. We show that the galaxy total B-band and K-band light (proxies for the stellar mass) are well correlated with LXP for both spirals and ellipticals, but the FIR and UV emission is only correlated for the spirals. We deconvolve LXP into two components, one that is proportional to the galaxy stellar mass (pop II), and another that is proportional to the galaxy SFR (pop I). We also note that IXOs (and nearly all of the other point sources) in both spirals and ellipticals have X-ray colors that are most consistent with power-law slopes of Gamma ˜ 1.5--3.0, which is inconsistent with high-mass XRBS (HMXBs). Thus, HMXBs are not important contributors to LXP. We have also found that IXOs in spiral galaxies may have a slightly harder X-ray spectrum than those in elliptical galaxies. The implications of these findings will be discussed.

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.

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...

40 CFR Table 5 to Subpart III of... - Compliance Requirements for Molded and Rebond Foam Production Affected Sources

Code of Federal Regulations, 2010 CFR

2010-07-01

... Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 5 Table 5 to Subpart III of Part 63—Compliance Requirements for Molded and Rebond Foam Production Affected Sources Emission point Emission point... Rebond Foam Production Affected Sources 5 Table 5 to Subpart III of Part 63 Protection of Environment...

40 CFR Table 5 to Subpart III of... - Compliance Requirements for Molded and Rebond Foam Production Affected Sources

Code of Federal Regulations, 2011 CFR

2011-07-01

... Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 5 Table 5 to Subpart III of Part 63—Compliance Requirements for Molded and Rebond Foam Production Affected Sources Emission point Emission point... Rebond Foam Production Affected Sources 5 Table 5 to Subpart III of Part 63 Protection of Environment...

40 CFR Table 5 to Subpart III of... - Compliance Requirements for Molded and Rebond Foam Production Affected Sources

Code of Federal Regulations, 2012 CFR

2012-07-01

... Flexible Polyurethane Foam Production Pt. 63, Subpt. III, Table 5 Table 5 to Subpart III of Part 63—Compliance Requirements for Molded and Rebond Foam Production Affected Sources Emission point Emission point... Rebond Foam Production Affected Sources 5 Table 5 to Subpart III of Part 63 Protection of Environment...

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 ...

The effect of tandem-ovoid titanium applicator on points A, B, bladder, and rectum doses in gynecological brachytherapy using 192Ir.

PubMed

Sadeghi, Mohammad Hosein; Sina, Sedigheh; Mehdizadeh, Amir; Faghihi, Reza; Moharramzadeh, Vahed; Meigooni, Ali Soleimani

2018-02-01

The dosimetry procedure by simple superposition accounts only for the self-shielding of the source and does not take into account the attenuation of photons by the applicators. The purpose of this investigation is an estimation of the effects of the tandem and ovoid applicator on dose distribution inside the phantom by MCNP5 Monte Carlo simulations. In this study, the superposition method is used for obtaining the dose distribution in the phantom without using the applicator for a typical gynecological brachytherapy (superposition-1). Then, the sources are simulated inside the tandem and ovoid applicator to identify the effect of applicator attenuation (superposition-2), and the dose at points A, B, bladder, and rectum were compared with the results of superposition. The exact dwell positions, times of the source, and positions of the dosimetry points were determined in images of a patient and treatment data of an adult woman patient from a cancer center. The MCNP5 Monte Carlo (MC) code was used for simulation of the phantoms, applicators, and the sources. The results of this study showed no significant differences between the results of superposition method and the MC simulations for different dosimetry points. The difference in all important dosimetry points was found to be less than 5%. According to the results, applicator attenuation has no significant effect on the calculated points dose, the superposition method, adding the dose of each source obtained by the MC simulation, can estimate the dose to points A, B, bladder, and rectum with good accuracy.

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.

Systematic Review: Impact of point sources on antibiotic-resistant bacteria in the natural environment.

PubMed

Bueno, I; Williams-Nguyen, J; Hwang, H; Sargeant, J M; Nault, A J; Singer, R S

2018-02-01

Point sources such as wastewater treatment plants and agricultural facilities may have a role in the dissemination of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARG). To analyse the evidence for increases in ARB in the natural environment associated with these point sources of ARB and ARG, we conducted a systematic review. We evaluated 5,247 records retrieved through database searches, including both studies that ascertained ARG and ARB outcomes. All studies were subjected to a screening process to assess relevance to the question and methodology to address our review question. A risk of bias assessment was conducted upon the final pool of studies included in the review. This article summarizes the evidence only for those studies with ARB outcomes (n = 47). Thirty-five studies were at high (n = 11) or at unclear (n = 24) risk of bias in the estimation of source effects due to lack of information and/or failure to control for confounders. Statistical analysis was used in ten studies, of which one assessed the effect of multiple sources using modelling approaches; none reported effect measures. Most studies reported higher ARB prevalence or concentration downstream/near the source. However, this evidence was primarily descriptive and it could not be concluded that there is a clear impact of point sources on increases in ARB in the environment. To quantify increases in ARB in the environment due to specific point sources, there is a need for studies that stress study design, control of biases and analytical tools to provide effect measure estimates. © 2017 Blackwell Verlag GmbH.

Impacts of the Detection of Cassiopeia A Point Source.

PubMed

Umeda; Nomoto; Tsuruta; Mineshige

2000-05-10

Very recently the Chandra first light observation discovered a point-like source in the Cassiopeia A supernova remnant. This detection was subsequently confirmed by the analyses of the archival data from both ROSAT and Einstein observations. Here we compare the results from these observations with the scenarios involving both black holes (BHs) and neutron stars (NSs). If this point source is a BH, we offer as a promising model a disk-corona type model with a low accretion rate in which a soft photon source at approximately 0.1 keV is Comptonized by higher energy electrons in the corona. If it is an NS, the dominant radiation observed by Chandra most likely originates from smaller, hotter regions of the stellar surface, but we argue that it is still worthwhile to compare the cooler component from the rest of the surface with cooling theories. We emphasize that the detection of this point source itself should potentially provide enormous impacts on the theories of supernova explosion, progenitor scenario, compact remnant formation, accretion to compact objects, and NS thermal evolution.

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.

40 CFR 454.22 - Effluent limitations and guidelines representing the degree of effluent reduction attainable by...

Code of Federal Regulations, 2012 CFR

2012-07-01

... POINT SOURCE CATEGORY Gum Rosin and Turpentine Subcategory § 454.22 Effluent limitations and guidelines... turpentine by a point source subject to the provisions of this paragraph after application of the best...

40 CFR 454.22 - Effluent limitations and guidelines representing the degree of effluent reduction attainable by...

Code of Federal Regulations, 2013 CFR

2013-07-01

... POINT SOURCE CATEGORY Gum Rosin and Turpentine Subcategory § 454.22 Effluent limitations and guidelines... turpentine by a point source subject to the provisions of this paragraph after application of the best...

40 CFR 454.22 - Effluent limitations and guidelines representing the degree of effluent reduction attainable by...

Code of Federal Regulations, 2014 CFR

2014-07-01

... POINT SOURCE CATEGORY Gum Rosin and Turpentine Subcategory § 454.22 Effluent limitations and guidelines... turpentine by a point source subject to the provisions of this paragraph after application of the best...

Search for Point Sources of Ultra-High-Energy Cosmic Rays above 4.0 × 1019 eV Using a Maximum Likelihood Ratio Test

NASA Astrophysics Data System (ADS)

Abbasi, R. U.; Abu-Zayyad, T.; Amann, J. F.; Archbold, G.; Atkins, R.; Bellido, J. A.; Belov, K.; Belz, J. W.; Ben-Zvi, S. Y.; Bergman, D. R.; Boyer, J. H.; Burt, G. W.; Cao, Z.; Clay, R. W.; Connolly, B. M.; Dawson, B. R.; Deng, W.; Farrar, G. R.; Fedorova, Y.; Findlay, J.; Finley, C. B.; Hanlon, W. F.; Hoffman, C. M.; Holzscheiter, M. H.; Hughes, G. A.; Hüntemeyer, P.; Jui, C. C. H.; Kim, K.; Kirn, M. A.; Knapp, B. C.; Loh, E. C.; Maestas, M. M.; Manago, N.; Mannel, E. J.; Marek, L. J.; Martens, K.; Matthews, J. A. J.; Matthews, J. N.; O'Neill, A.; Painter, C. A.; Perera, L.; Reil, K.; Riehle, R.; Roberts, M. D.; Sasaki, M.; Schnetzer, S. R.; Seman, M.; Simpson, K. M.; Sinnis, G.; Smith, J. D.; Snow, R.; Sokolsky, P.; Song, C.; Springer, R. W.; Stokes, B. T.; Thomas, J. R.; Thomas, S. B.; Thomson, G. B.; Tupa, D.; Westerhoff, S.; Wiencke, L. R.; Zech, A.

2005-04-01

We present the results of a search for cosmic-ray point sources at energies in excess of 4.0×1019 eV in the combined data sets recorded by the Akeno Giant Air Shower Array and High Resolution Fly's Eye stereo experiments. The analysis is based on a maximum likelihood ratio test using the probability density function for each event rather than requiring an a priori choice of a fixed angular bin size. No statistically significant clustering of events consistent with a point source is found.

Identifying EGRET Sources

NASA Technical Reports Server (NTRS)

Schlegel, E.; Norris, Jay P. (Technical Monitor)

2002-01-01

This project was awarded funding from the CGRO program to support ROSAT and ground-based observations of unidentified sources from data obtained by the EGRET instrument on the Compton Gamma-Ray Observatory. The critical items in the project are the individual ROSAT observations that are used to cover the 99% error circle of the unidentified EGRET source. Each error circle is a degree or larger in diameter. Each ROSAT field is about 30 deg in diameter. Hence, a number (>4) of ROSAT pointings must be obtained for each EGRET source to cover the field. The scheduling of ROSAT observations is carried out to maximize the efficiency of the total schedule. As a result, each pointing is broken into one or more sub-pointings of various exposure times. This project was awarded ROSAT observing time for four unidentified EGRET sources, summarized in the table. The column headings are defined as follows: 'Coverings' = number of observations to cover the error circle; 'SubPtg' = total number of sub-pointings to observe all of the coverings; 'Rec'd' = number of individual sub-pointings received to date; 'CompFlds' = number of individual coverings for which the requested complete exposure has been received. Processing of the data can not occur until a complete exposure has been accumulated for each covering.

An infrared sky model based on the IRAS point source data

NASA Technical Reports Server (NTRS)

Cohen, Martin; Walker, Russell; Wainscoat, Richard; Volk, Kevin; Walker, Helen; Schwartz, Deborah

1990-01-01

A detailed model for the infrared point source sky is presented that comprises geometrically and physically realistic representations of the galactic disk, bulge, spheroid, spiral arms, molecular ring, and absolute magnitudes. The model was guided by a parallel Monte Carlo simulation of the Galaxy. The content of the galactic source table constitutes an excellent match to the 12 micrometer luminosity function in the simulation, as well as the luminosity functions at V and K. Models are given for predicting the density of asteroids to be observed, and the diffuse background radiance of the Zodiacal cloud. The model can be used to predict the character of the point source sky expected for observations from future infrared space experiments.

KM3NeT/ARCA sensitivity to point-like neutrino sources

NASA Astrophysics Data System (ADS)

Trovato, A.; KM3NeT Collaboration

2017-09-01

KM3NeT is network of deep-sea neutrino telescopes in the Mediterranean Sea aiming at the discovery of cosmic neutrino sources (ARCA) and the determination of the neutrino mass hierarchy (ORCA). The geographical location of KM3NeT in the Northern hemisphere allows to observe most of the Galactic Plane, including the Galactic Centre. Thanks to its good angular resolution, prime targets of KM3NeT/ARCA are point-like neutrino sources and in particular galactic sources.

An efficient method to compute microlensed light curves for point sources

NASA Technical Reports Server (NTRS)

Witt, Hans J.

1993-01-01

We present a method to compute microlensed light curves for point sources. This method has the general advantage that all microimages contributing to the light curve are found. While a source moves along a straight line, all micro images are located either on the primary image track or on the secondary image tracks (loops). The primary image track extends from - infinity to + infinity and is made of many sequents which are continuously connected. All the secondary image tracks (loops) begin and end on the lensing point masses. The method can be applied to any microlensing situation with point masses in the deflector plane, even for the overcritical case and surface densities close to the critical. Furthermore, we present general rules to evaluate the light curve for a straight track arbitrary placed in the caustic network of a sample of many point masses.

Equivalent charge source model based iterative maximum neighbor weight for sparse EEG source localization.

PubMed

Xu, Peng; Tian, Yin; Lei, Xu; Hu, Xiao; Yao, Dezhong

2008-12-01

How to localize the neural electric activities within brain effectively and precisely from the scalp electroencephalogram (EEG) recordings is a critical issue for current study in clinical neurology and cognitive neuroscience. In this paper, based on the charge source model and the iterative re-weighted strategy, proposed is a new maximum neighbor weight based iterative sparse source imaging method, termed as CMOSS (Charge source model based Maximum neighbOr weight Sparse Solution). Different from the weight used in focal underdetermined system solver (FOCUSS) where the weight for each point in the discrete solution space is independently updated in iterations, the new designed weight for each point in each iteration is determined by the source solution of the last iteration at both the point and its neighbors. Using such a new weight, the next iteration may have a bigger chance to rectify the local source location bias existed in the previous iteration solution. The simulation studies with comparison to FOCUSS and LORETA for various source configurations were conducted on a realistic 3-shell head model, and the results confirmed the validation of CMOSS for sparse EEG source localization. Finally, CMOSS was applied to localize sources elicited in a visual stimuli experiment, and the result was consistent with those source areas involved in visual processing reported in previous studies.

Chandra Deep X-ray Observation of a Typical Galactic Plane Region and Near-Infrared Identification

NASA Technical Reports Server (NTRS)

Ebisawa, K.; Tsujimoto, M.; Paizis, A.; Hamaguichi, K.; Bamba, A.; Cutri, R.; Kaneda, H.; Maeda, Y.; Sato, G.; Senda, A.

2004-01-01

Using the Chandra Advanced CCD Imaging Spectrometer Imaging array (ACIS-I), we have carried out a deep hard X-ray observation of the Galactic plane region at (l,b) approx. (28.5 deg,0.0 deg), where no discrete X-ray source has been reported previously. We have detected 274 new point X-ray sources (4 sigma confidence) as well as strong Galactic diffuse emission within two partidly overlapping ACIS-I fields (approx. 250 sq arcmin in total). The point source sensitivity was approx. 3 x 10(exp -15)ergs/s/sq cm in the hard X-ray band (2-10 keV and approx. 2 x 10(exp -16) ergs/s/sq cm in the soft band (0.5-2 keV). Sum of all the detected point source fluxes account for only approx. 10 % of the total X-ray fluxes in the field of view. In order to explain the total X-ray fluxes by a superposition of fainter point sources, an extremely rapid increase of the source population is required below our sensitivity limit, which is hardly reconciled with any source distribution in the Galactic plane. Therefore, we conclude that X-ray emission from the Galactic plane has truly diffuse origin. Only 26 point sources were detected both in the soft and hard bands, indicating that there are two distinct classes of the X-ray sources distinguished by the spectral hardness ratio. Surface number density of the hard sources is only slightly higher than observed at the high Galactic latitude regions, strongly suggesting that majority of the hard X-ray sources are active galaxies seen through the Galactic plane. Following the Chandra observation, we have performed a near-infrared (NIR) survey with SOFI at ESO/NTT to identify these new X-ray sources. Since the Galactic plane is opaque in NIR, we did not see the background extragalactic sources in NIR. In fact, only 22 % of the hard sources had NIR counterparts which are most likely to be Galactic origin. Composite X-ray energy spectrum of those hard X-ray sources having NIR counterparts exhibits a narrow approx. 6.7 keV iron emission line, which is a signature of Galactic quiescent cataclysmic variables (CVs).

Fast generation of complex modulation video holograms using temporal redundancy compression and hybrid point-source/wave-field approaches

NASA Astrophysics Data System (ADS)

Gilles, Antonin; Gioia, Patrick; Cozot, Rémi; Morin, Luce

2015-09-01

The hybrid point-source/wave-field method is a newly proposed approach for Computer-Generated Hologram (CGH) calculation, based on the slicing of the scene into several depth layers parallel to the hologram plane. The complex wave scattered by each depth layer is then computed using either a wave-field or a point-source approach according to a threshold criterion on the number of points within the layer. Finally, the complex waves scattered by all the depth layers are summed up in order to obtain the final CGH. Although outperforming both point-source and wave-field methods without producing any visible artifact, this approach has not yet been used for animated holograms, and the possible exploitation of temporal redundancies has not been studied. In this paper, we propose a fast computation of video holograms by taking into account those redundancies. Our algorithm consists of three steps. First, intensity and depth data of the current 3D video frame are extracted and compared with those of the previous frame in order to remove temporally redundant data. Then the CGH pattern for this compressed frame is generated using the hybrid point-source/wave-field approach. The resulting CGH pattern is finally transmitted to the video output and stored in the previous frame buffer. Experimental results reveal that our proposed method is able to produce video holograms at interactive rates without producing any visible artifact.

Development document for proposed effluent-limitations guidelines and standards for shipbuilding and repair. Point-source category

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

Not Available

1979-12-01

The document contains a discussion of the technical rationale for effluent limitations guidelines for the Shipbuilding and Repair Point Source Category, and the control and treatment technologies which form the basis for these guidelines.

VizieR Online Data Catalog: First Fermi-LAT Inner Galaxy point source catalog (Ajello+, 2016)

NASA Astrophysics Data System (ADS)

Ajello, M.; Albert, A.; Atwood, W. B.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Cecchi, C.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; di Venere, L.; Drell, P. S.; Favuzzi, C.; Ferrara, E. C.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Guiriec, S.; Gustafsson, M.; Harding, A. K.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Jogler, T.; Johannesson, G.; Johnson, A. S.; Kamae, T.; Karwin, C.; Knodlseder, J.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Malyshev, D.; Manfreda, A.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nuss, E.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Raino, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Ritz, S.; Sanchez-Conde, M.; Parkinson, P. M. S.; Sgro, C.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Takahashi, H.; Thayer, J. B.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Winer, B. L.; Wood, K. S.; Zaharijas, G.; Zimmer, S.

2018-01-01

The Fermi Large Area Telescope (LAT) has provided the most detailed view to date of the emission toward the Galactic center (GC) in high-energy γ-rays. This paper describes the analysis of data taken during the first 62 months of the mission in the energy range 1-100GeV from a 15°x15° region about the direction of the GC. Specialized interstellar emission models (IEMs) are constructed to enable the separation of the γ-ray emissions produced by cosmic ray particles interacting with the interstellar gas and radiation fields in the Milky Way into that from the inner ~1kpc surrounding the GC, and that from the rest of the Galaxy. A catalog of point sources for the 15°x15° region is self-consistently constructed using these IEMs: the First Fermi-LAT Inner Galaxy Point Source Catalog (1FIG). The spatial locations, fluxes, and spectral properties of the 1FIG sources are presented, and compared with γ-ray point sources over the same region taken from existing catalogs. After subtracting the interstellar emission and point-source contributions a residual is found. If templates that peak toward the GC are used to model the positive residual the agreement with the data improves, but none of the additional templates tried account for all of its spatial structure. The spectrum of the positive residual modeled with these templates has a strong dependence on the choice of IEM. (2 data files).

The feasibility of effluent trading in the oil and gas industry

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

Veil, J.A.

1997-09-01

In January 1996, the U.S. Environmental Protection Agency (EPA) released a policy statement endorsing wastewater effluent trading in watersheds, hoping to promote additional interest in the subject. The policy describes five types of effluent trades - point source/point source, point source/nonpoint source, pretreatment, intraplant, and nonpoint source/nonpoint source. This paper evaluates the feasibility of effluent trading for facilities in the oil and gas industry. The evaluation leads to the conclusion that potential for effluent trading is very low in the exploration and production and distribution and marketing sectors; trading potential is moderate for the refining sector except for intraplant trades,more » for which the potential is high. Good potential also exists for other types of water-related trades that do not directly involve effluents (e.g., wetlands mitigation banking). The potential for effluent trading in the energy industries and in other sectors would be enhanced if Congress amended the Clean Water Act (CWA) to formally authorize such trading.« less

The potential for effluent trading in the energy industries.

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

Veil, J. A.; Environmental Assessment

1998-01-01

In January 1996, the US Environmental Protection Agency (EPA) released a policy statement endorsing wastewater effluent trading in watersheds, hoping to promote additional interest in the subject. The policy describes five types of effluent trades: point source/point source, point source/nonpoint source, pretreatment, intraplant and nonpoint source/nonpoint source. This paper evaluates the feasibility of implementing these types of effluent trading for facilities in the oil and gas, electric power and coal industries. This paper finds that the potential for effluent trading in these industries is limited because trades would generally need to involve toxic pollutants, which can only be traded undermore » a narrow range of circumstances. However, good potential exists for other types of water-related trades that do not directly involve effluents (e.g. wetlands mitigation banking and voluntary environmental projects). The potential for effluent trading in the energy industries and in other sectors would be enhanced if Congress amended the Clean Water Act (CWA) to formally authorize such trading.« less

Determining the Intensity of a Point-Like Source Observed on the Background of AN Extended Source

NASA Astrophysics Data System (ADS)

Kornienko, Y. V.; Skuratovskiy, S. I.

2014-12-01

The problem of determining the time dependence of intensity of a point-like source in case of atmospheric blur is formulated and solved by using the Bayesian statistical approach. A pointlike source is supposed to be observed on the background of an extended source with constant in time though unknown brightness. The equation system for optimal statistical estimation of the sequence of intensity values in observation moments is obtained. The problem is particularly relevant for studying gravitational mirages which appear while observing a quasar through the gravitational field of a far galaxy.

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.

New method of a "point-like" neutron source creation based on sharp focusing of high-current deuteron beam onto deuterium-saturated target for neutron tomography

NASA Astrophysics Data System (ADS)

Golubev, S.; Skalyga, V.; Izotov, I.; Sidorov, A.

2017-02-01

A possibility of a compact powerful point-like neutron source creation is discussed. Neutron yield of the source based on deuterium-deuterium (D-D) reaction is estimated at the level of 1011 s-1 (1013 s-1 for deuterium-tritium reaction). The fusion takes place due to bombardment of deuterium- (or tritium) loaded target by high-current focused deuterium ion beam with energy of 100 keV. The ion beam is formed by means of high-current quasi-gasdynamic ion source of a new generation based on an electron cyclotron resonance (ECR) discharge in an open magnetic trap sustained by powerful microwave radiation. The prospects of proposed generator for neutron tomography are discussed. Suggested method is compared to the point-like neutron sources based on a spark produced by powerful femtosecond laser pulses.

THE FIRST COMBINED SEARCH FOR NEUTRINO POINT-SOURCES IN THE SOUTHERN HEMISPHERE WITH THE ANTARES AND ICECUBE NEUTRINO TELESCOPES

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

Adrián-Martínez, S.; Ardid, M.; Albert, A.

2016-05-20

We present the results of searches for point-like sources of neutrinos based on the first combined analysis of data from both the ANTARES and IceCube neutrino telescopes. The combination of both detectors, which differ in size and location, forms a window in the southern sky where the sensitivity to point sources improves by up to a factor of 2 compared with individual analyses. Using data recorded by ANTARES from 2007 to 2012, and by IceCube from 2008 to 2011, we search for sources of neutrino emission both across the southern sky and from a preselected list of candidate objects. Nomore » significant excess over background has been found in these searches, and flux upper limits for the candidate sources are presented for E {sup −2.5} and E {sup −2} power-law spectra with different energy cut-offs.« less

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.

Speciated atmospheric mercury and its potential source in Guiyang, China

NASA Astrophysics Data System (ADS)

Fu, Xuewu; Feng, Xinbin; Qiu, Guangle; Shang, Lihai; Zhang, Hui

2011-08-01

Speciated atmospheric mercury (Hg) including gaseous elemental mercury (GEM), particulate Hg (PHg), and reactive gaseous Hg (RGM) were continuously measured at an urban site in Guiyang city, southwest China from August to December 2009. The averaged concentrations for GEM, PHg, and RGM were 9.72 ± 10.2 ng m -3, 368 ± 676 pg m -3, and 35.7 ± 43.9 pg m -3, respectively, which were all highly elevated compared to observations at urban sites in Europe and North America. GEM and PHg were characterized by similar monthly and diurnal patterns, with elevated levels in cold months and nighttime, respectively. In contrast, RGM did not exhibit clear monthly and diurnal variations. The variations of GEM, PHg, and RGM indicate the sampling site was significantly impacted by sources in the city municipal area. Sources identification implied that both residential coal burning and large point sources were responsible to the elevated GEM and PHg concentrations; whereas point sources were the major contributors to elevated RGM concentrations. Point sources played a different role in regulating GEM, PHg, and RGM concentrations. Aside from residential emissions, PHg levels was mostly affected by small-scale coal combustion boilers situated to the east of the sampling site, which were scarcely equipped or lacking particulate control devices; whereas point sources situated to the east, southeast, and southwest of the sampling played an important role on the distribution of atmospheric GEM and RGM.

Estimation of nutrient discharge from the Yangtze River to the East China Sea and the identification of nutrient sources.

PubMed

Tong, Yindong; Bu, Xiaoge; Chen, Junyue; Zhou, Feng; Chen, Long; Liu, Maodian; Tan, Xin; Yu, Tao; Zhang, Wei; Mi, Zhaorong; Ma, Lekuan; Wang, Xuejun; Ni, Jing

2017-01-05

Based on a time-series dataset and the mass balance method, the contributions of various sources to the nutrient discharges from the Yangtze River to the East China Sea are identified. The results indicate that the nutrient concentrations vary considerably among different sections of the Yangtze River. Non-point sources are an important source of nutrients to the Yangtze River, contributing about 36% and 63% of the nitrogen and phosphorus discharged into the East China Sea, respectively. Nutrient inputs from non-point sources vary among the sections of the Yangtze River, and the contributions of non-point sources increase from upstream to downstream. Considering the rice growing patterns in the Yangtze River Basin, the synchrony of rice tillering and the wet seasons might be an important cause of the high nutrient discharge from the non-point sources. Based on our calculations, a reduction of 0.99Tg per year in total nitrogen discharges from the Yangtze River would be needed to limit the occurrences of harmful algal blooms in the East China Sea to 15 times per year. The extensive construction of sewage treatment plants in urban areas may have only a limited effect on reducing the occurrences of harmful algal blooms in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

A model of the 8-25 micron point source infrared sky

NASA Technical Reports Server (NTRS)

Wainscoat, Richard J.; Cohen, Martin; Volk, Kevin; Walker, Helen J.; Schwartz, Deborah E.

1992-01-01

We present a detailed model for the IR point-source sky that comprises geometrically and physically realistic representations of the Galactic disk, bulge, stellar halo, spiral arms (including the 'local arm'), molecular ring, and the extragalactic sky. We represent each of the distinct Galactic components by up to 87 types of Galactic source, each fully characterized by scale heights, space densities, and absolute magnitudes at BVJHK, 12, and 25 microns. The model is guided by a parallel Monte Carlo simulation of the Galaxy at 12 microns. The content of our Galactic source table constitutes a good match to the 12 micron luminosity function in the simulation, as well as to the luminosity functions at V and K. We are able to produce differential and cumulative IR source counts for any bandpass lying fully within the IRAS Low-Resolution Spectrometer's range (7.7-22.7 microns as well as for the IRAS 12 and 25 micron bands. These source counts match the IRAS observations well. The model can be used to predict the character of the point source sky expected for observations from IR space experiments.

Double point source W-phase inversion: Real-time implementation and automated model selection

USGS Publications Warehouse

Nealy, Jennifer; Hayes, Gavin

2015-01-01

Rapid and accurate characterization of an earthquake source is an extremely important and ever evolving field of research. Within this field, source inversion of the W-phase has recently been shown to be an effective technique, which can be efficiently implemented in real-time. An extension to the W-phase source inversion is presented in which two point sources are derived to better characterize complex earthquakes. A single source inversion followed by a double point source inversion with centroid locations fixed at the single source solution location can be efficiently run as part of earthquake monitoring network operational procedures. In order to determine the most appropriate solution, i.e., whether an earthquake is most appropriately described by a single source or a double source, an Akaike information criterion (AIC) test is performed. Analyses of all earthquakes of magnitude 7.5 and greater occurring since January 2000 were performed with extended analyses of the September 29, 2009 magnitude 8.1 Samoa earthquake and the April 19, 2014 magnitude 7.5 Papua New Guinea earthquake. The AIC test is shown to be able to accurately select the most appropriate model and the selected W-phase inversion is shown to yield reliable solutions that match published analyses of the same events.

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...

Better Assessment Science Integrating Point and Nonpoint Sources

EPA Science Inventory

Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is not a model per se, but is a multipurpose environmental decision support system for use by regional, state, and local agencies in performing watershed- and water-quality-based studies. BASI...

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...

Self-force on a point charge and linear source in the space of a screw dislocation

NASA Astrophysics Data System (ADS)

Azevedo, Sérgio; Moraes, Fernando

2000-03-01

Using a description of defect in solids in terms of three-dimensional gravity, we determine the eletrostatic self-force acting on a point teste charge and a linear source in the presence of a screw dislocation.

TMDLS: AFTER POINT SOURCES, WHAT CAN WE DO NEXT?

EPA Science Inventory

Section 303(d) of the Clean Water Act required TMDLs (total maximum daily loads) for all waters for which effluent or point source limitations are insufficient to meet water quality standards. Concerns may arise regarding the manner by which TMDLs are established, the corrective ...

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.

An X-ray investigation of the unusual supernova remnant CTB 80

NASA Technical Reports Server (NTRS)

Wang, Z. R.; Seward, F. D.

1984-01-01

The X-ray properties of SNR CTB 80 (G68.8 + 2.8) are discussed based on both low- and high-resolution images from the Einstein satellite. The X-ray maps show a point source coinciding with the region of maximum radio emission. Diffuse X-ray emission is evident mainly along the radio lobe extending about 8 arcmin east of the point source and aligned with the projected magnetic field lines. The observed X-ray luminosity is 3.2 x 10 to the 34th ergs/s with 1.0 x 10 to the 3th ergs/s from the point source (assuming a distance of 3 kpc). There is also faint, diffuse, X-ray emission south of the point source, where radio emission is absent. The unusual radio and X-ray morphologies are interpreted as a result of relativistic jets energized by the central object, and the possible association of CTB 80 with SN 1408 as recorded by Chinese observers is discussed.

First Neutrino Point-Source Results from the 22 String Icecube Detector

NASA Astrophysics Data System (ADS)

Abbasi, R.; Abdou, Y.; Ackermann, M.; Adams, J.; Aguilar, J.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bissok, M.; Blaufuss, E.; Boersma, D. J.; Bohm, C.; Bolmont, J.; Böser, S.; Botner, O.; Bradley, L.; Braun, J.; Breder, D.; Castermans, T.; Chirkin, D.; Christy, B.; Clem, J.; Cohen, S.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; Day, C. T.; De Clercq, C.; Demirörs, L.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; De Young, T.; Diaz-Velez, J. C.; Dreyer, J.; Dumm, J. P.; Duvoort, M. R.; Edwards, W. R.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Feusels, T.; Filimonov, K.; Finley, C.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Ganugapati, R.; Gerhardt, L.; Gladstone, L.; Goldschmidt, A.; Goodman, J. A.; Gozzini, R.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gunasingha, R. M.; Gurtner, M.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Hasegawa, Y.; Heise, J.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Imlay, R. L.; Inaba, M.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kelley, J. L.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Klepser, S.; Knops, S.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Kuehn, K.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Lauer, R.; Leich, H.; Lennarz, D.; Lucke, A.; Lundberg, J.; Lünemann, J.; Madsen, J.; Majumdar, P.; Maruyama, R.; Mase, K.; Matis, H. S.; McParland, C. P.; Meagher, K.; Merck, M.; Mészáros, P.; Middell, E.; Milke, N.; Miyamoto, H.; Mohr, A.; Montaruli, T.; Morse, R.; Movit, S. M.; Münich, K.; Nahnhauer, R.; Nam, J. W.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; Ono, M.; Panknin, S.; Patton, S.; Pérez de los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Pohl, A. C.; Porrata, R.; Potthoff, N.; Price, P. B.; Prikockis, M.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Roucelle, C.; Rutledge, D.; Ryckbosch, D.; Sander, H.-G.; Sarkar, S.; Satalecka, K.; Schlenstedt, S.; Schmidt, T.; Schneider, D.; Schukraft, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stoufer, M. C.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Sulanke, K.-H.; Sullivan, G. W.; Swillens, Q.; Taboada, I.; Tarasova, O.; Tepe, A.; Ter-Antonyan, S.; Terranova, C.; Tilav, S.; Tluczykont, M.; Toale, P. A.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; Van Overloop, A.; Voigt, B.; Walck, C.; Waldenmaier, T.; Walter, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebusch, C. H.; Wiedemann, A.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Xu, X. W.; Yodh, G.; Ice Cube Collaboration

2009-08-01

We present new results of searches for neutrino point sources in the northern sky, using data recorded in 2007-2008 with 22 strings of the IceCube detector (approximately one-fourth of the planned total) and 275.7 days of live time. The final sample of 5114 neutrino candidate events agrees well with the expected background of atmospheric muon neutrinos and a small component of atmospheric muons. No evidence of a point source is found, with the most significant excess of events in the sky at 2.2σ after accounting for all trials. The average upper limit over the northern sky for point sources of muon-neutrinos with E -2 spectrum is E^{2} Φ_{ν_{μ}} < 1.4 × 10^{-11} TeV cm^{-2} s^{-1}, in the energy range from 3 TeV to 3 PeV, improving the previous best average upper limit by the AMANDA-II detector by a factor of 2.

Dissolved organic matter fluorescence at wavelength 275/342 nm as a key indicator for detection of point-source contamination in a large Chinese drinking water lake.

PubMed

Zhou, Yongqiang; Jeppesen, Erik; Zhang, Yunlin; Shi, Kun; Liu, Xiaohan; Zhu, Guangwei

2016-02-01

Surface drinking water sources have been threatened globally and there have been few attempts to detect point-source contamination in these waters using chromophoric dissolved organic matter (CDOM) fluorescence. To determine the optimal wavelength derived from CDOM fluorescence as an indicator of point-source contamination in drinking waters, a combination of field campaigns in Lake Qiandao and a laboratory wastewater addition experiment was used. Parallel factor (PARAFAC) analysis identified six components, including three humic-like, two tryptophan-like, and one tyrosine-like component. All metrics showed strong correlation with wastewater addition (r(2) > 0.90, p < 0.0001). Both the field campaigns and the laboratory contamination experiment revealed that CDOM fluorescence at 275/342 nm was the most responsive wavelength to the point-source contamination in the lake. Our results suggest that pollutants in Lake Qiandao had the highest concentrations in the river mouths of upstream inflow tributaries and the single wavelength at 275/342 nm may be adapted for online or in situ fluorescence measurements as an early warning of contamination events. This study demonstrates the potential utility of CDOM fluorescence to monitor water quality in surface drinking water sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Bisphenol A emission factors from industrial sources and elimination rates in a sewage treatment plant.

PubMed

Fuerhacker, M

2003-01-01

Bisphenol A (BPA) is widely used for the production of epoxy resins and polycarbonate plastics and is considered an endocrine disruptor. Special in vitro test systems and animal experiments showed a weak estrogenic activity. Aquatic wildlife especially could be endangered by waste water discharges. To manage possible risks arising from BPA emissions the major fluxes need to be investigated and the sources of the contamination of municipal treatment plants need to be determined. In this study, five major industrial point sources, two different household areas and the influent and effluent of the corresponding treatment plant (WWTP) were monitored simultaneously at a plant serving 120,000 population equivalents. A paper producing plant was the major BPA contributor to the influent load of the wastewater treatment plant. All the other emissions from point sources, including the two household areas, were considerably lower. The minimum elimination rate in the WTTP could be determined at 78% with an average of 89% of the total BPA-load. For a possible pollution-forecast, or for a comparison between different point sources, emission factors based on COD-emissions were calculated for industrial and household point sources at BPA/COD-ratios between 1.4 x 10(-8) - 125 x 10(-8) and 1.3 x 10(-6) - 6.3 x 10(-6), respectively.

The effect of tandem-ovoid titanium applicator on points A, B, bladder, and rectum doses in gynecological brachytherapy using 192Ir

PubMed Central

Sadeghi, Mohammad Hosein; Mehdizadeh, Amir; Faghihi, Reza; Moharramzadeh, Vahed; Meigooni, Ali Soleimani

2018-01-01

Purpose The dosimetry procedure by simple superposition accounts only for the self-shielding of the source and does not take into account the attenuation of photons by the applicators. The purpose of this investigation is an estimation of the effects of the tandem and ovoid applicator on dose distribution inside the phantom by MCNP5 Monte Carlo simulations. Material and methods In this study, the superposition method is used for obtaining the dose distribution in the phantom without using the applicator for a typical gynecological brachytherapy (superposition-1). Then, the sources are simulated inside the tandem and ovoid applicator to identify the effect of applicator attenuation (superposition-2), and the dose at points A, B, bladder, and rectum were compared with the results of superposition. The exact dwell positions, times of the source, and positions of the dosimetry points were determined in images of a patient and treatment data of an adult woman patient from a cancer center. The MCNP5 Monte Carlo (MC) code was used for simulation of the phantoms, applicators, and the sources. Results The results of this study showed no significant differences between the results of superposition method and the MC simulations for different dosimetry points. The difference in all important dosimetry points was found to be less than 5%. Conclusions According to the results, applicator attenuation has no significant effect on the calculated points dose, the superposition method, adding the dose of each source obtained by the MC simulation, can estimate the dose to points A, B, bladder, and rectum with good accuracy. PMID:29619061

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.

HIREGS observations of the Galactic center and Galactic plane: Separation of the diffuse Galactic hard X-ray continuum from the point source spectra

NASA Technical Reports Server (NTRS)

Boggs, S. E.; Lin, R. P.; Coburn, W.; Feffer, P.; Pelling, R. M.; Schroeder, P.; Slassi-Sennou, S.

1997-01-01

The balloon-borne high resolution gamma ray and X-ray germanium spectrometer (HIREGS) was used to observe the Galactic center and two positions along the Galactic plane from Antarctica in January 1995. For its flight, the collimators were configured to measure the Galactic diffuse hard X-ray continuum between 20 and 200 keV by directly measuring the point source contributions to the wide field of view flux for subtraction. The hard X-ray spectra of GX 1+4 and GRO J1655-40 were measured with the diffuse continuum subtracted off. The analysis technique for source separation is discussed and the preliminary separated spectra for these point sources and the Galactic diffuse emission are presented.

Fermi-LAT Observations of High-Energy Gamma-Ray Emission Toward the Galactic Center

DOE PAGES

Ajello, M.

2016-02-26

The Fermi Large Area Telescope (LAT) has provided the most detailed view to date of the emission towards the Galactic centre (GC) in high-energy γ-rays. This paper describes the analysis of data taken during the first 62 months of the mission in the energy range 1 - 100 GeV from a 15° X15° region about the direction of the GC, and implications for the interstellar emissions produced by cosmic ray (CR) particles interacting with the gas and radiation fields in the inner Galaxy and for the point sources detected. Specialised interstellar emission models (IEMs) are constructed that enable separation ofmore » the γ-ray emission from the inner ~ 1 kpc about the GC from the fore- and background emission from the Galaxy. Based on these models, the interstellar emission from CR electrons interacting with the interstellar radiation field via the inverse Compton (IC) process and CR nuclei inelastically scattering off the gas producing γ-rays via π⁰ decays from the inner ~ 1 kpc is determined. The IC contribution is found to be dominant in the region and strongly enhanced compared to previous studies. A catalog of point sources for the 15 °X 15 °region is self-consistently constructed using these IEMs: the First Fermi–LAT Inner Galaxy point source Catalog (1FIG). The spatial locations, fluxes, and spectral properties of the 1FIG sources are presented, and compared with γ-ray point sources over the same region taken from existing catalogs, including the Third Fermi–LAT Source Catalog (3FGL). In general, the spatial density of 1FIG sources differs from those in the 3FGL, which is attributed to the different treatments of the interstellar emission and energy ranges used by the respective analyses. Three 1FIG sources are found to spatially overlap with supernova remnants (SNRs) listed in Green’s SNR catalog; these SNRs have not previously been associated with high-energy γ-ray sources. Most 3FGL sources with known multi-wavelength counterparts are also found. However, the majority of 1FIG point sources are unassociated. After subtracting the interstellar emission and point-source contributions from the data a residual is found that is a sub-dominant fraction of the total flux. But, it is brighter than the γ-ray emission associated with interstellar gas in the inner ~ 1 kpc derived for the IEMs used in this paper, and comparable to the integrated brightness of the point sources in the region for energies & 3 GeV. If spatial templates that peak toward the GC are used to model the positive residual and included in the total model for the 1515°X° region, the agreement with the data improves, but they do not account for all the residual structure. The spectrum of the positive residual modelled with these templates has a strong dependence on the choice of IEM.« less

40 CFR 429.145 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS TIMBER PRODUCTS PROCESSING POINT SOURCE CATEGORY Particleboard Manufacturing Subcategory § 429.145 Pretreatment standards for existing sources (PSES). Any existing source...

40 CFR 417.84 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Soaps Subcategory § 417.84 Pretreatment standards for existing sources. Any existing source...

40 CFR 417.84 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Soaps Subcategory § 417.84 Pretreatment standards for existing sources. Any existing source...

40 CFR 417.84 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Soaps Subcategory § 417.84 Pretreatment standards for existing sources. Any existing source...

40 CFR 417.84 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Soaps Subcategory § 417.84 Pretreatment standards for existing sources. Any existing source...

40 CFR 417.84 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Soaps Subcategory § 417.84 Pretreatment standards for existing sources. Any existing source...

Lung motion estimation using dynamic point shifting: An innovative model based on a robust point matching algorithm

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

Yi, Jianbing, E-mail: yijianbing8@163.com; Yang, Xuan, E-mail: xyang0520@263.net; Li, Yan-Ran, E-mail: lyran@szu.edu.cn

2015-10-15

Purpose: Image-guided radiotherapy is an advanced 4D radiotherapy technique that has been developed in recent years. However, respiratory motion causes significant uncertainties in image-guided radiotherapy procedures. To address these issues, an innovative lung motion estimation model based on a robust point matching is proposed in this paper. Methods: An innovative robust point matching algorithm using dynamic point shifting is proposed to estimate patient-specific lung motion during free breathing from 4D computed tomography data. The correspondence of the landmark points is determined from the Euclidean distance between the landmark points and the similarity between the local images that are centered atmore » points at the same time. To ensure that the points in the source image correspond to the points in the target image during other phases, the virtual target points are first created and shifted based on the similarity between the local image centered at the source point and the local image centered at the virtual target point. Second, the target points are shifted by the constrained inverse function mapping the target points to the virtual target points. The source point set and shifted target point set are used to estimate the transformation function between the source image and target image. Results: The performances of the authors’ method are evaluated on two publicly available DIR-lab and POPI-model lung datasets. For computing target registration errors on 750 landmark points in six phases of the DIR-lab dataset and 37 landmark points in ten phases of the POPI-model dataset, the mean and standard deviation by the authors’ method are 1.11 and 1.11 mm, but they are 2.33 and 2.32 mm without considering image intensity, and 1.17 and 1.19 mm with sliding conditions. For the two phases of maximum inhalation and maximum exhalation in the DIR-lab dataset with 300 landmark points of each case, the mean and standard deviation of target registration errors on the 3000 landmark points of ten cases by the authors’ method are 1.21 and 1.04 mm. In the EMPIRE10 lung registration challenge, the authors’ method ranks 24 of 39. According to the index of the maximum shear stretch, the authors’ method is also efficient to describe the discontinuous motion at the lung boundaries. Conclusions: By establishing the correspondence of the landmark points in the source phase and the other target phases combining shape matching and image intensity matching together, the mismatching issue in the robust point matching algorithm is adequately addressed. The target registration errors are statistically reduced by shifting the virtual target points and target points. The authors’ method with consideration of sliding conditions can effectively estimate the discontinuous motion, and the estimated motion is natural. The primary limitation of the proposed method is that the temporal constraints of the trajectories of voxels are not introduced into the motion model. However, the proposed method provides satisfactory motion information, which results in precise tumor coverage by the radiation dose during radiotherapy.« less

Lung motion estimation using dynamic point shifting: An innovative model based on a robust point matching algorithm.

PubMed

Yi, Jianbing; Yang, Xuan; Chen, Guoliang; Li, Yan-Ran

2015-10-01

Image-guided radiotherapy is an advanced 4D radiotherapy technique that has been developed in recent years. However, respiratory motion causes significant uncertainties in image-guided radiotherapy procedures. To address these issues, an innovative lung motion estimation model based on a robust point matching is proposed in this paper. An innovative robust point matching algorithm using dynamic point shifting is proposed to estimate patient-specific lung motion during free breathing from 4D computed tomography data. The correspondence of the landmark points is determined from the Euclidean distance between the landmark points and the similarity between the local images that are centered at points at the same time. To ensure that the points in the source image correspond to the points in the target image during other phases, the virtual target points are first created and shifted based on the similarity between the local image centered at the source point and the local image centered at the virtual target point. Second, the target points are shifted by the constrained inverse function mapping the target points to the virtual target points. The source point set and shifted target point set are used to estimate the transformation function between the source image and target image. The performances of the authors' method are evaluated on two publicly available DIR-lab and POPI-model lung datasets. For computing target registration errors on 750 landmark points in six phases of the DIR-lab dataset and 37 landmark points in ten phases of the POPI-model dataset, the mean and standard deviation by the authors' method are 1.11 and 1.11 mm, but they are 2.33 and 2.32 mm without considering image intensity, and 1.17 and 1.19 mm with sliding conditions. For the two phases of maximum inhalation and maximum exhalation in the DIR-lab dataset with 300 landmark points of each case, the mean and standard deviation of target registration errors on the 3000 landmark points of ten cases by the authors' method are 1.21 and 1.04 mm. In the EMPIRE10 lung registration challenge, the authors' method ranks 24 of 39. According to the index of the maximum shear stretch, the authors' method is also efficient to describe the discontinuous motion at the lung boundaries. By establishing the correspondence of the landmark points in the source phase and the other target phases combining shape matching and image intensity matching together, the mismatching issue in the robust point matching algorithm is adequately addressed. The target registration errors are statistically reduced by shifting the virtual target points and target points. The authors' method with consideration of sliding conditions can effectively estimate the discontinuous motion, and the estimated motion is natural. The primary limitation of the proposed method is that the temporal constraints of the trajectories of voxels are not introduced into the motion model. However, the proposed method provides satisfactory motion information, which results in precise tumor coverage by the radiation dose during radiotherapy.

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.

Statistical measurement of the gamma-ray source-count distribution as a function of energy

NASA Astrophysics Data System (ADS)

Zechlin, H.-S.; Cuoco, A.; Donato, F.; Fornengo, N.; Regis, M.

2017-01-01

Photon counts statistics have recently been proven to provide a sensitive observable for characterizing gamma-ray source populations and for measuring the composition of the gamma-ray sky. In this work, we generalize the use of the standard 1-point probability distribution function (1pPDF) to decompose the high-latitude gamma-ray emission observed with Fermi-LAT into: (i) point-source contributions, (ii) the Galactic foreground contribution, and (iii) a diffuse isotropic background contribution. We analyze gamma-ray data in five adjacent energy bands between 1 and 171 GeV. We measure the source-count distribution dN/dS as a function of energy, and demonstrate that our results extend current measurements from source catalogs to the regime of so far undetected sources. Our method improves the sensitivity for resolving point-source populations by about one order of magnitude in flux. The dN/dS distribution as a function of flux is found to be compatible with a broken power law. We derive upper limits on further possible breaks as well as the angular power of unresolved sources. We discuss the composition of the gamma-ray sky and capabilities of the 1pPDF method.

A source-attractor approach to network detection of radiation sources

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

Wu, Qishi; Barry, M. L..; Grieme, M.

Radiation source detection using a network of detectors is an active field of research for homeland security and defense applications. We propose Source-attractor Radiation Detection (SRD) method to aggregate measurements from a network of detectors for radiation source detection. SRD method models a potential radiation source as a magnet -like attractor that pulls in pre-computed virtual points from the detector locations. A detection decision is made if a sufficient level of attraction, quantified by the increase in the clustering of the shifted virtual points, is observed. Compared with traditional methods, SRD has the following advantages: i) it does not requiremore » an accurate estimate of the source location from limited and noise-corrupted sensor readings, unlike the localizationbased methods, and ii) its virtual point shifting and clustering calculation involve simple arithmetic operations based on the number of detectors, avoiding the high computational complexity of grid-based likelihood estimation methods. We evaluate its detection performance using canonical datasets from Domestic Nuclear Detection Office s (DNDO) Intelligence Radiation Sensors Systems (IRSS) tests. SRD achieves both lower false alarm rate and false negative rate compared to three existing algorithms for network source detection.« less

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.

Multiple window spatial registration error of a gamma camera: 133Ba point source as a replacement of the NEMA procedure.

PubMed

Bergmann, Helmar; Minear, Gregory; Raith, Maria; Schaffarich, Peter M

2008-12-09

The accuracy of multiple window spatial resolution characterises the performance of a gamma camera for dual isotope imaging. In the present study we investigate an alternative method to the standard NEMA procedure for measuring this performance parameter. A long-lived 133Ba point source with gamma energies close to 67Ga and a single bore lead collimator were used to measure the multiple window spatial registration error. Calculation of the positions of the point source in the images used the NEMA algorithm. The results were validated against the values obtained by the standard NEMA procedure which uses a liquid 67Ga source with collimation. Of the source-collimator configurations under investigation an optimum collimator geometry, consisting of a 5 mm thick lead disk with a diameter of 46 mm and a 5 mm central bore, was selected. The multiple window spatial registration errors obtained by the 133Ba method showed excellent reproducibility (standard deviation < 0.07 mm). The values were compared with the results from the NEMA procedure obtained at the same locations and showed small differences with a correlation coefficient of 0.51 (p < 0.05). In addition, the 133Ba point source method proved to be much easier to use. A Bland-Altman analysis showed that the 133Ba and the 67Ga Method can be used interchangeably. The 133Ba point source method measures the multiple window spatial registration error with essentially the same accuracy as the NEMA-recommended procedure, but is easier and safer to use and has the potential to replace the current standard procedure.

An Update on Phased Array Results Obtained on the GE Counter-Rotating Open Rotor Model

NASA Technical Reports Server (NTRS)

Podboy, Gary; Horvath, Csaba; Envia, Edmane

2013-01-01

Beamform maps have been generated from 1) simulated data generated by the LINPROP code and 2) actual experimental phased array data obtained on the GE Counter-rotating open rotor model. The beamform maps show that many of the tones in the experimental data come from their corresponding Mach radius. If the phased array points to the Mach radius associated with a tone then it is likely that the tone is a result of the loading and thickness noise on the blades. In this case, the phased array correctly points to where the noise is coming from and indicates the axial location of the loudest source in the image but not necessarily the correct vertical location. If the phased array does not point to the Mach radius associated with a tone then some mechanism other than loading and thickness noise may control the amplitude of the tone. In this case, the phased array may or may not point to the actual source. If the source is not rotating it is likely that the phased array points to the source. If the source is rotating it is likely that the phased array indicates the axial location of the loudest source but not necessarily the correct vertical location. These results indicate that you have to be careful in how you interpret phased array data obtained on an open rotor since they may show the tones coming from a location other than the source location. With a subsonic tip speed open rotor the tones can come form locations outboard of the blade tips. This has implications regarding noise shielding.

Volatile organic compound emissions from the oil and natural gas industry in the Uinta Basin, Utah: point sources compared to ambient air composition

NASA Astrophysics Data System (ADS)

Warneke, C.; Geiger, F.; Edwards, P. M.; Dube, W.; Pétron, G.; Kofler, J.; Zahn, A.; Brown, S. S.; Graus, M.; Gilman, J.; Lerner, B.; Peischl, J.; Ryerson, T. B.; de Gouw, J. A.; Roberts, J. M.

2014-05-01

The emissions of volatile organic compounds (VOCs) associated with oil and natural gas production in the Uinta Basin, Utah were measured at a ground site in Horse Pool and from a NOAA mobile laboratory with PTR-MS instruments. The VOC compositions in the vicinity of individual gas and oil wells and other point sources such as evaporation ponds, compressor stations and injection wells are compared to the measurements at Horse Pool. High mixing ratios of aromatics, alkanes, cycloalkanes and methanol were observed for extended periods of time and short-term spikes caused by local point sources. The mixing ratios during the time the mobile laboratory spent on the well pads were averaged. High mixing ratios were found close to all point sources, but gas wells using dry-gas collection, which means dehydration happens at the well, were clearly associated with higher mixing ratios than other wells. Another large source was the flowback pond near a recently hydraulically re-fractured gas well. The comparison of the VOC composition of the emissions from the oil and natural gas wells showed that wet gas collection wells compared well with the majority of the data at Horse Pool and that oil wells compared well with the rest of the ground site data. Oil wells on average emit heavier compounds than gas wells. The mobile laboratory measurements confirm the results from an emissions inventory: the main VOC source categories from individual point sources are dehydrators, oil and condensate tank flashing and pneumatic devices and pumps. Raw natural gas is emitted from the pneumatic devices and pumps and heavier VOC mixes from the tank flashings.

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...

40 CFR 414.111 - Toxic pollutant standards for indirect discharge point sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 29 2014-07-01 2012-07-01 true Toxic pollutant standards for indirect discharge point sources. 414.111 Section 414.111 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Indirect...

40 CFR 414.111 - Toxic pollutant standards for indirect discharge point sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Toxic pollutant standards for indirect discharge point sources. 414.111 Section 414.111 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Indirect...

40 CFR 414.111 - Toxic pollutant standards for indirect discharge point sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 30 2012-07-01 2012-07-01 false Toxic pollutant standards for indirect discharge point sources. 414.111 Section 414.111 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Indirect...

40 CFR 414.111 - Toxic pollutant standards for indirect discharge point sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Toxic pollutant standards for indirect discharge point sources. 414.111 Section 414.111 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Indirect...

40 CFR 414.111 - Toxic pollutant standards for indirect discharge point sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Toxic pollutant standards for indirect discharge point sources. 414.111 Section 414.111 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Indirect...

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...

75 FR 68215 - Direct Final Rule Staying Numeric Limitation for the Construction and Development Point Source...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-05

... required to obtain NPDES permit coverage and performing the following activities: Construction of buildings, including building, developing and general contracting. Heavy and civil 237 engineering construction... Rule Staying Numeric Limitation for the Construction and Development Point Source Category AGENCY...

75 FR 68305 - Proposed Rule Staying Numeric Limitation for the Construction and Development Point Source Category

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-05

... coverage and performing the following activities: Construction of buildings, including building, developing... Staying Numeric Limitation for the Construction and Development Point Source Category AGENCY... effluent limitation of 280 NTU and associated monitoring requirements for the Construction and Development...

Experiential knowledge of expert coaches can help identify informational constraints on performance of dynamic interceptive actions.

PubMed

Greenwood, Daniel; Davids, Keith; Renshaw, Ian

2014-01-01

Coordination of dynamic interceptive movements is predicated on cyclical relations between an individual's actions and information sources from the performance environment. To identify dynamic informational constraints, which are interwoven with individual and task constraints, coaches' experiential knowledge provides a complementary source to support empirical understanding of performance in sport. In this study, 15 expert coaches from 3 sports (track and field, gymnastics and cricket) participated in a semi-structured interview process to identify potential informational constraints which they perceived to regulate action during run-up performance. Expert coaches' experiential knowledge revealed multiple information sources which may constrain performance adaptations in such locomotor pointing tasks. In addition to the locomotor pointing target, coaches' knowledge highlighted two other key informational constraints: vertical reference points located near the locomotor pointing target and a check mark located prior to the locomotor pointing target. This study highlights opportunities for broadening the understanding of perception and action coupling processes, and the identified information sources warrant further empirical investigation as potential constraints on athletic performance. Integration of experiential knowledge of expert coaches with theoretically driven empirical knowledge represents a promising avenue to drive future applied science research and pedagogical practice.

Distributed Sensing for Quickest Change Detection of Point Radiation Sources

DTIC Science & Technology

2017-02-01

point occurs simultaneously at all sensor nodes, thus neglecting signal propagation delays. For nuclear radiation , the observation period, which is on... nuclear radiation using a sensor network,” in Homeland Security (HST), 2012 IEEE Conference on Technologies for. IEEE, 2012, pp. 648–653. [8] G. Lorden...Distributed Sensing for Quickest Change Detection of Point Radiation Sources Gene T. Whipps⋆† Emre Ertin† Randolph L. Moses† †The Ohio State

The source provenance of an obsidian Eden point from Sierra County, New Mexico

DOE PAGES

Dolan, Sean Gregory; Berryman, Judy; Shackley, M. Steven

2016-01-02

Eden projectile points associated with the Cody complex are underrepresented in the late Paleoindian record of the American Southwest. EDXRF analysis of an obsidian Eden point from a site in Sierra County, New Mexico demonstrates this artifact is from the Cerro del Medio (Valles Rhyolite) source in the Jemez Mountains. Lastly, we contextualize our results by examining variability in obsidian procurement practices beyond the Cody heartland in southcentral New Mexico.

40 CFR 429.146 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS TIMBER PRODUCTS PROCESSING POINT SOURCE CATEGORY Particleboard Manufacturing Subcategory § 429.146 Pretreatment standards for new sources (PSNS). Any new source subject to...

40 CFR 411.26 - Pretreatment standards for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUIDELINES AND STANDARDS CEMENT MANUFACTURING POINT SOURCE CATEGORY Leaching Subcategory § 411.26 Pretreatment standards for new sources. Any new source subject to this subpart that introduces process...

A study of the far infrared counterparts of new candidates for planetary nebulae

NASA Astrophysics Data System (ADS)

Iyengar, K. V. K.

1986-05-01

The IRAS Point Source Catalog was searched for infrared counterparts of the fourteen new candidates for planetary nebulae of low surface brightness detected by Hartl and Tritton (1985). Five of these candidates were identified with sources in the Catalog. All five nebulae are found in regions of high cirrus flux at 100 microns, and all have both point sources and small size extended sources with numbers varying from field to field. The infrared emission from these nebulae is connected with dust temperatures of about 100 K, characteristic of planetary nebulae.

A smart market for nutrient credit trading to incentivize wetland construction

NASA Astrophysics Data System (ADS)

Raffensperger, John F.; Prabodanie, R. A. Ranga; Kostel, Jill A.

2017-03-01

Nutrient trading and constructed wetlands are widely discussed solutions to reduce nutrient pollution. Nutrient markets usually include agricultural nonpoint sources and municipal and industrial point sources, but these markets rarely include investors who construct wetlands to sell nutrient reduction credits. We propose a new market design for trading nutrient credits, with both point source and non-point source traders, explicitly incorporating the option of landowners to build nutrient removal wetlands. The proposed trading program is designed as a smart market with centralized clearing, done with an optimization. The market design addresses the varying impacts of runoff over space and time, and the lumpiness of wetland investments. We simulated the market for the Big Bureau Creek watershed in north-central Illinois. We found that the proposed smart market would incentivize wetland construction by assuring reasonable payments for the ecosystem services provided. The proposed market mechanism selects wetland locations strategically taking into account both the cost and nutrient removal efficiencies. The centralized market produces locational prices that would incentivize farmers to reduce nutrients, which is voluntary. As we illustrate, wetland builders' participation in nutrient trading would enable the point sources and environmental organizations to buy low cost nutrient credits.

40 CFR 427.86 - Pretreatment standards for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Coating or Finishing of Asbestos Textiles Subcategory § 427.86 Pretreatment standards for new sources. Any new source subject to...

40 CFR 427.86 - Pretreatment standards for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Coating or Finishing of Asbestos Textiles Subcategory § 427.86 Pretreatment standards for new sources. Any new source subject to...

40 CFR 427.86 - Pretreatment standards for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Coating or Finishing of Asbestos Textiles Subcategory § 427.86 Pretreatment standards for new sources. Any new source subject to...

40 CFR 417.36 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Soap Manufacturing by Fatty Acid Neutralization Subcategory § 417.36 Pretreatment standards for new sources. Any new source subject...

40 CFR 407.76 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE CATEGORY Canned and Preserved Vegetables Subcategory § 407.76 Pretreatment standards for new sources. Any new source...

40 CFR 407.66 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE CATEGORY Canned and Preserved Fruits Subcategory § 407.66 Pretreatment standards for new sources. Any new source...

40 CFR 417.74 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Bar Soaps Subcategory § 417.74 Pretreatment standards for existing sources. Any existing source subject to...

40 CFR 417.74 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Bar Soaps Subcategory § 417.74 Pretreatment standards for existing sources. Any existing source subject to...

40 CFR 417.74 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Bar Soaps Subcategory § 417.74 Pretreatment standards for existing sources. Any existing source subject to...

40 CFR 417.74 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Bar Soaps Subcategory § 417.74 Pretreatment standards for existing sources. Any existing source subject to...

40 CFR 417.74 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Bar Soaps Subcategory § 417.74 Pretreatment standards for existing sources. Any existing source subject to...

A New Source Biasing Approach in ADVANTG

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

Bevill, Aaron M; Mosher, Scott W

2012-01-01

The ADVANTG code has been developed at Oak Ridge National Laboratory to generate biased sources and weight window maps for MCNP using the CADIS and FW-CADIS methods. In preparation for an upcoming RSICC release, a new approach for generating a biased source has been developed. This improvement streamlines user input and improves reliability. Previous versions of ADVANTG generated the biased source from ADVANTG input, writing an entirely new general fixed-source definition (SDEF). Because volumetric sources were translated into SDEF-format as a finite set of points, the user had to perform a convergence study to determine whether the number of sourcemore » points used accurately represented the source region. Further, the large number of points that must be written in SDEF-format made the MCNP input and output files excessively long and difficult to debug. ADVANTG now reads SDEF-format distributions and generates corresponding source biasing cards, eliminating the need for a convergence study. Many problems of interest use complicated source regions that are defined using cell rejection. In cell rejection, the source distribution in space is defined using an arbitrarily complex cell and a simple bounding region. Source positions are sampled within the bounding region but accepted only if they fall within the cell; otherwise, the position is resampled entirely. When biasing in space is applied to sources that use rejection sampling, current versions of MCNP do not account for the rejection in setting the source weight of histories, resulting in an 'unfair game'. This problem was circumvented in previous versions of ADVANTG by translating volumetric sources into a finite set of points, which does not alter the mean history weight ({bar w}). To use biasing parameters without otherwise modifying the original cell-rejection SDEF-format source, ADVANTG users now apply a correction factor for {bar w} in post-processing. A stratified-random sampling approach in ADVANTG is under development to automatically report the correction factor with estimated uncertainty. This study demonstrates the use of ADVANTG's new source biasing method, including the application of {bar w}.« less

High Resolution Geological Site Characterization Utilizing Ground Motion Data

DTIC Science & Technology

1992-06-26

Hayward, 1992). 15 Acquistion I 16 The source characterization array was composed of 28 stations evenly 17 distributed on the circumference of a...of analog anti alias filters, no prefiltering was applied during II acquistion . 12 Results 13 We deployed 9 different sources within the source...calculated using a 1024 point Hamming window applied to 32 the original 1000 point detrended and padded time series. These are then contoured as a 33

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

40 CFR 63.74 - Demonstration of early reduction.

Code of Federal Regulations, 2010 CFR

2010-07-01

... pollutant emissions; (2) A complete list of all emission points of hazardous air pollutants in the source... pollutants from each emission point listed in the source in paragraph (b)(2) of this section; (3) The... subject emissions; and (ii) For calculations based on emission factors, material balance, or engineering...

40 CFR 415.237 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... control technology (BCT). 415.237 Section 415.237 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE... control technology (BCT). Except as provided in 40 CFR 125.30 through 125.32, any existing point source...

40 CFR 415.207 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... control technology (BCT). 415.207 Section 415.207 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE... technology (BCT). Except as provided in 40 CFR 125.30 through 125.32 any existing point source subject to...

40 CFR 415.227 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... control technology (BCT). 415.227 Section 415.227 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE... technology (BCT). Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to...

40 CFR 414.110 - Applicability; description of the subcategory of indirect discharge point sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Applicability; description of the subcategory of indirect discharge point sources. 414.110 Section 414.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND...

40 CFR 414.110 - Applicability; description of the subcategory of indirect discharge point sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 29 2014-07-01 2012-07-01 true Applicability; description of the subcategory of indirect discharge point sources. 414.110 Section 414.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND...

40 CFR 414.110 - Applicability; description of the subcategory of indirect discharge point sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability; description of the subcategory of indirect discharge point sources. 414.110 Section 414.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND...

40 CFR 414.110 - Applicability; description of the subcategory of indirect discharge point sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Applicability; description of the subcategory of indirect discharge point sources. 414.110 Section 414.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND...

40 CFR 414.110 - Applicability; description of the subcategory of indirect discharge point sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 30 2012-07-01 2012-07-01 false Applicability; description of the subcategory of indirect discharge point sources. 414.110 Section 414.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND...

Detecting Near-Earth Objects Using Cross-Correlation with a Point Spread Function

DTIC Science & Technology

2009-03-01

greater than .001 seconds [Goodman, 2000]. Cross-Correlation Cross-Correlation measures the strength and direction of the linear relationship between...real(ifft2(fftshift(otf_long)))); %normalize point spread funtion 55 if (Corner == 1) psf_source = makeshift(psf*source_img(ccd_x/2,ccd_y/2

EVALUATING POINT-NONPOINT SOURCE WATER QUALITY TRADING IN A RARITAN RIVER BASIN SUB-WATERSHED

EPA Science Inventory

This project addresses water quality issues in the Raritan River Basin of New Jersey. It will build upon an existing study that determined the technical feasibility of implementing a point-nonpoint source water quality trading program in the Basin. Water quality trading is ...

40 CFR 430.113 - 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 Fine and Lightweight Papers from Purchased Pulp Subcategory § 430.113 Effluent limitations... existing point source subject to this subpart shall achieve the following effluent limitations representing...

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...

Studies on the Effects of High Renewable Penetrations on Driving Point Impedance and Voltage Regulator Performance: National Renewable Energy Laboratory/Sacramento Municipal Utility District Load Tap Changer Driving Point Impedance Project

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

Nagarajan, Adarsh; Coddington, Michael H.; Brown, David

Voltage regulators perform as desired when regulating from the source to the load and when regulating from a strong source (utility) to a weak source (distributed generation). (See the glossary for definitions of a strong source and weak source.) Even when the control is provisioned for reverse operation, it has been observed that tap-changing voltage regulators do not perform as desired in reverse when attempting regulation from the weak source to the strong source. The region of performance that is not as well understood is the regulation between sources that are approaching equal strength. As part of this study, wemore » explored all three scenarios: regulator control from a strong source to a weak source (classic case), control from a weak source to a strong source (during reverse power flow), and control between equivalent sources.« less

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.

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

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.

40 CFR 443.16 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.16 Pretreatment standards for new sources. Any...

40 CFR 443.36 - Pretreatment standard for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Roofing Subcategory § 443.36 Pretreatment standard for new sources. Any...

40 CFR 443.36 - Pretreatment standard for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Roofing Subcategory § 443.36 Pretreatment standard for new sources. Any...

40 CFR 443.26 - Pretreatment standard for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.26 Pretreatment standard for new sources. Any...

40 CFR 443.16 - Pretreatment standards for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.16 Pretreatment standards for new sources. Any...

40 CFR 443.26 - Pretreatment standard for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.26 Pretreatment standard for new sources. Any...

The Unicellular State as a Point Source in a Quantum Biological System

PubMed Central

Torday, John S.; Miller, William B.

2016-01-01

A point source is the central and most important point or place for any group of cohering phenomena. Evolutionary development presumes that biological processes are sequentially linked, but neither directed from, nor centralized within, any specific biologic structure or stage. However, such an epigenomic entity exists and its transforming effects can be understood through the obligatory recapitulation of all eukaryotic lifeforms through a zygotic unicellular phase. This requisite biological conjunction can now be properly assessed as the focal point of reconciliation between biology and quantum phenomena, illustrated by deconvoluting complex physiologic traits back to their unicellular origins. PMID:27240413

Photon-assisted quantum transport in quantum point contacts

NASA Astrophysics Data System (ADS)

Hu, Qing

1993-02-01

We have studied the feasibility of photon-assisted quantum transport in semiconductor quantum point contacts or electron waveguides. Due to photon-induced intersubband transitions, it is expected that the drain/source conductance of the quantum point contacts can be modulated by far-infrared (f not less than 300 GHz) radiation, which is similar to the photon-assisted tunneling in superconducting tunnel junctions. An antenna/gate electrodes structure will be used to couple far-infrared photons into quantum point contacts of submicron dimensions. A calculation of the photon-induced drain/source current as a function of the far-infrared radiation power is also presented.

BEAMLINE-CONTROLLED STEERING OF SOURCE-POINT ANGLE AT THE ADVANCED PHOTON SOURCE

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

Emery, L.; Fystro, G.; Shang, H.

An EPICS-based steering software system has been implemented for beamline personnel to directly steer the angle of the synchrotron radiation sources at the Advanced Photon Source. A script running on a workstation monitors "start steering" beamline EPICS records, and effects a steering given by the value of the "angle request" EPICS record. The new system makes the steering process much faster than before, although the older steering protocols can still be used. The robustness features of the original steering remain. Feedback messages are provided to the beamlines and the accelerator operators. Underpinning this new steering protocol is the recent refinementmore » of the global orbit feedback process whereby feedforward of dipole corrector set points and orbit set points are used to create a local steering bump in a rapid and seamless way.« less

40 CFR 443.15 - Standards of performance for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.15 Standards of performance for new sources...

40 CFR 443.36 - Pretreatment standard for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Roofing Subcategory § 443.36 Pretreatment standard for new sources. Any...

40 CFR 443.25 - Standards of performance for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.25 Standards of performance for new sources...

40 CFR 443.16 - Pretreatment standards for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.16 Pretreatment standards for new sources. Any...

40 CFR 443.36 - Pretreatment standard for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Roofing Subcategory § 443.36 Pretreatment standard for new sources. Any...

40 CFR 443.26 - Pretreatment standard for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.26 Pretreatment standard for new sources. Any...

40 CFR 443.16 - Pretreatment standards for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.16 Pretreatment standards for new sources. Any...

40 CFR 443.25 - Standards of performance for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.25 Standards of performance for new sources...

40 CFR 443.26 - Pretreatment standard for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.26 Pretreatment standard for new sources. Any...

40 CFR 443.26 - Pretreatment standard for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.26 Pretreatment standard for new sources. Any...

40 CFR 443.16 - Pretreatment standards for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.16 Pretreatment standards for new sources. Any...

40 CFR 443.36 - Pretreatment standard for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Roofing Subcategory § 443.36 Pretreatment standard for new sources. Any...

40 CFR 443.15 - Standards of performance for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.15 Standards of performance for new sources...

Validity of vaccination cards and parental recall to estimate vaccination coverage: a systematic review of the literature.

PubMed

Miles, Melody; Ryman, Tove K; Dietz, Vance; Zell, Elizabeth; Luman, Elizabeth T

2013-03-15

Immunization programs frequently rely on household vaccination cards, parental recall, or both to calculate vaccination coverage. This information is used at both the global and national level for planning and allocating performance-based funds. However, the validity of household-derived coverage sources has not yet been widely assessed or discussed. To advance knowledge on the validity of different sources of immunization coverage, we undertook a global review of literature. We assessed concordance, sensitivity, specificity, positive and negative predictive value, and coverage percentage point difference when subtracting household vaccination source from a medical provider source. Median coverage difference per paper ranged from -61 to +1 percentage points between card versus provider sources and -58 to +45 percentage points between recall versus provider source. When card and recall sources were combined, median coverage difference ranged from -40 to +56 percentage points. Overall, concordance, sensitivity, specificity, positive and negative predictive value showed poor agreement, providing evidence that household vaccination information may not be reliable, and should be interpreted with care. While only 5 papers (11%) included in this review were from low-middle income countries, low-middle income countries often rely more heavily on household vaccination information for decision making. Recommended actions include strengthening quality of child-level data and increasing investments to improve vaccination card availability and card marking. There is also an urgent need for additional validation studies of vaccine coverage in low and middle income countries. Copyright © 2013. Published by Elsevier Ltd.

Source splitting via the point source method

NASA Astrophysics Data System (ADS)

Potthast, Roland; Fazi, Filippo M.; Nelson, Philip A.

2010-04-01

We introduce a new algorithm for source identification and field splitting based on the point source method (Potthast 1998 A point-source method for inverse acoustic and electromagnetic obstacle scattering problems IMA J. Appl. Math. 61 119-40, Potthast R 1996 A fast new method to solve inverse scattering problems Inverse Problems 12 731-42). The task is to separate the sound fields uj, j = 1, ..., n of n \\in \\mathbb {N} sound sources supported in different bounded domains G1, ..., Gn in \\mathbb {R}^3 from measurements of the field on some microphone array—mathematically speaking from the knowledge of the sum of the fields u = u1 + sdotsdotsdot + un on some open subset Λ of a plane. The main idea of the scheme is to calculate filter functions g_1, \\ldots, g_n, n\\in \\mathbb {N} , to construct uell for ell = 1, ..., n from u|Λ in the form u_{\\ell }(x) = \\int _{\\Lambda } g_{\\ell,x}(y) u(y) {\\,\\rm d}s(y), \\qquad \\ell =1,\\ldots, n. We will provide the complete mathematical theory for the field splitting via the point source method. In particular, we describe uniqueness, solvability of the problem and convergence and stability of the algorithm. In the second part we describe the practical realization of the splitting for real data measurements carried out at the Institute for Sound and Vibration Research at Southampton, UK. A practical demonstration of the original recording and the splitting results for real data is available online.

THE CHANDRA SURVEY OF THE COSMOS FIELD. II. SOURCE DETECTION AND PHOTOMETRY

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

Puccetti, S.; Vignali, C.; Cappelluti, N.

2009-12-01

The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra program that covers the central contiguous {approx}0.92 deg{sup 2} of the COSMOS field. C-COSMOS is the result of a complex tiling, with every position being observed in up to six overlapping pointings (four overlapping pointings in most of the central {approx}0.45 deg{sup 2} area with the best exposure, and two overlapping pointings in most of the surrounding area, covering an additional {approx}0.47 deg{sup 2}). Therefore, the full exploitation of the C-COSMOS data requires a dedicated and accurate analysis focused on three main issues: (1) maximizing the sensitivity when themore » point-spread function (PSF) changes strongly among different observations of the same source (from {approx}1 arcsec up to {approx}10 arcsec half-power radius); (2) resolving close pairs; and (3) obtaining the best source localization and count rate. We present here our treatment of four key analysis items: source detection, localization, photometry, and survey sensitivity. Our final procedure consists of a two step procedure: (1) a wavelet detection algorithm to find source candidates and (2) a maximum likelihood PSF fitting algorithm to evaluate the source count rates and the probability that each source candidate is a fluctuation of the background. We discuss the main characteristics of this procedure, which was the result of detailed comparisons between different detection algorithms and photometry tools, calibrated with extensive and dedicated simulations.« less

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.

VizieR Online Data Catalog: GUViCS. Ultraviolet Source Catalogs (Voyer+, 2014)

NASA Astrophysics Data System (ADS)

Voyer, E. N.; Boselli, A.; Boissier, S.; Heinis, S.; Cortese, L.; Ferrarese, L.; Cote, P.; Cuillandre, J.-C.; Gwyn, S. D. J.; Peng, E. W.; Zhang, H.; Liu, C.

2014-07-01

These catalogs are based on GALEX NUV and FUV source detections in and behind the Virgo Cluster. The detections are split into catalogs of extended sources and point-like sources. The UV Virgo Cluster Extended Source catalog (UV_VES.fit) provides the deepest and most extensive UV photometric data of extended galaxies in Virgo to date. If certain data is not available for a given source then a null value is entered (e.g. -999, -99). UV point-like sources are matched with SDSS, NGVS, and NED and the relevant photometry and further data from these databases/catalogs are provided in this compilation of catalogs. The primary GUViCS UV Virgo Cluster Point-Like Source catalog is UV_VPS.fit. This catalog provides the most useful GALEX pipeline NUV and FUV photometric parameters, and categorizes sources as stars, Virgo members, and background sources, when possible. It also provides identifiers for optical matches in the SDSS and NED, and indicates if a match exists in the NGVS, only if GUViCS-optical matches are one-to-one. NED spectroscopic redshifts are also listed for GUViCS-NED one-to-one matches. If certain data is not available for a given source a null value is entered. Additionally, the catalog is useful for quick access to optical data on one-to-one GUViCS-SDSS matches.The only parameter available in the catalog for UV sources that have multiple SDSS matches is the total number of multiple matches, i.e. SDSSNUMMTCHS. Multiple GUViCS sources matched to the same SDSS source are also flagged given a total number of matches, SDSSNUMMTCHS, of one. All other fields for multiple matches are set to a null value of -99. In order to obtain full optical SDSS data for multiply matched UV sources in both scenarios, the user can cross-correlate the GUViCS ID of the sources of interest with the full GUViCS-SDSS matched catalog in GUV_SDSS.fit. The GUViCS-SDSS matched catalog, GUV_SDSS.fit, provides the most relevant SDSS data on all GUViCS-SDSS matches, including one-to-one matches and multiply matched sources. The catalog gives full SDSS identification information, complete SDSS photometric measurements in multiple aperture types, and complete redshift information (photometric and spectroscopic). It is ideal for large statistical studies of galaxy populations at multiple wavelengths in the background of the Virgo Cluster. The catalog can also be used as a starting point to study and search for previously unknown UV-bright point-like objects within the Virgo Cluster. If certain data is not available for a given source that field is given a null value. (6 data files).

Aeroacoustic catastrophes: upstream cusp beaming in Lilley's equation.

PubMed

Stone, J T; Self, R H; Howls, C J

2017-05-01

The downstream propagation of high-frequency acoustic waves from a point source in a subsonic jet obeying Lilley's equation is well known to be organized around the so-called 'cone of silence', a fold catastrophe across which the amplitude may be modelled uniformly using Airy functions. Here we show that acoustic waves not only unexpectedly propagate upstream, but also are organized at constant distance from the point source around a cusp catastrophe with amplitude modelled locally by the Pearcey function. Furthermore, the cone of silence is revealed to be a cross-section of a swallowtail catastrophe. One consequence of these discoveries is that the peak acoustic field upstream is not only structurally stable but also at a similar level to the known downstream field. The fine structure of the upstream cusp is blurred out by distributions of symmetric acoustic sources, but peak upstream acoustic beaming persists when asymmetries are introduced, from either arrays of discrete point sources or perturbed continuum ring source distributions. These results may pose interesting questions for future novel jet-aircraft engine designs where asymmetric source distributions arise.

Structure of the X-ray source in the Virgo cluster of galaxies

NASA Technical Reports Server (NTRS)

Gorenstein, P.; Fabricant, D.; Topka, K.; Tucker, W.; Harnden, F. R., Jr.

1977-01-01

High-angular-resolution observations in the 0.15-1.5-keV band with an imaging X-ray telescope shows the extended X-ray source in the Virgo cluster of galaxies to be a diffuse halo of about 15 arcmin core radius surrounding M87. The angular structure of the surface brightness is marginally consistent with either of two simple models: (1) an isothermal (or adiabatic or hydrostatic) sphere plus a point source at M87 accounting for 12% of the total 0.5-1.5-keV intensity or (2) a power-law function without a discrete point source. No evidence for a point source is seen in the 0.15-0.28-keV band, which is consistent with self-absorption by about 10 to the 21st power per sq cm of matter having a cosmic abundance. The power-law models are motivated by the idea that radiation losses regulate the accretion of matter onto M87 and can account for the observed difference in the size of the X-ray source as seen in the present measurements and at higher energies.

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.

A very deep IRAS survey at l(II) = 97 deg, b(II) = +30 deg

NASA Technical Reports Server (NTRS)

Hacking, Perry; Houck, James R.

1987-01-01

A deep far-infrared survey is presented using over 1000 scans made of a 4 to 6 sq. deg. field at the north ecliptic pole by the IRAS. Point sources from this survey are up to 100 times fainter than the IRAS point source catalog at 12 and 25 micrometers, and up to 10 times fainter at 60 and 100 micrometers. The 12 and 25 micrometer maps are instrumental noise-limited, and the 60 and 100 micrometer maps are confusion noise-limited. The majority of the 12 micrometer point sources are stars within the Milky Way. The 25 micrometer sources are composed almost equally of stars and galaxies. About 80% of the 60 micrometer sources correspond to galaxies on Palomar Observatory Sky Survey (POSS) enlargements. The remaining 20% are probably galaxies below the POSS detection limit. The differential source counts are presented and compared with what is predicted by the Bahcall and Soneira Standard Galaxy Model using the B-V-12 micrometer colors of stars without circumstellar dust shells given by Waters, Cote and Aumann. The 60 micrometer source counts are inconsistent with those predicted for a uniformly distributed, nonevolving universe. The implications are briefly discussed.

A model for jet-noise analysis using pressure-gradient correlations on an imaginary cone

NASA Technical Reports Server (NTRS)

Norum, T. D.

1974-01-01

The technique for determining the near and far acoustic field of a jet through measurements of pressure-gradient correlations on an imaginary conical surface surrounding the jet is discussed. The necessary analytical developments are presented, and their feasibility is checked by using a point source as the sound generator. The distribution of the apparent sources on the cone, equivalent to the point source, is determined in terms of the pressure-gradient correlations.

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.

Correcting STIS CCD Point-Source Spectra for CTE Loss

NASA Technical Reports Server (NTRS)

Goudfrooij, Paul; Bohlin, Ralph C.; Maiz-Apellaniz, Jesus

2006-01-01

We review the on-orbit spectroscopic observations that are being used to characterize the Charge Transfer Efficiency (CTE) of the STIS CCD in spectroscopic mode. We parameterize the CTE-related loss for spectrophotometry of point sources in terms of dependencies on the brightness of the source, the background level, the signal in the PSF outside the standard extraction box, and the time of observation. Primary constraints on our correction algorithm are provided by measurements of the CTE loss rates for simulated spectra (images of a tungsten lamp taken through slits oriented along the dispersion axis) combined with estimates of CTE losses for actual spectra of spectrophotometric standard stars in the first order CCD modes. For point-source spectra at the standard reference position at the CCD center, CTE losses as large as 30% are corrected to within approx.1% RMS after application of the algorithm presented here, rendering the Poisson noise associated with the source detection itself to be the dominant contributor to the total flux calibration uncertainty.

Interferometric superlocalization of two incoherent optical point sources.

PubMed

Nair, Ranjith; Tsang, Mankei

2016-02-22

A novel interferometric method - SLIVER (Super Localization by Image inVERsion interferometry) - is proposed for estimating the separation of two incoherent point sources with a mean squared error that does not deteriorate as the sources are brought closer. The essential component of the interferometer is an image inversion device that inverts the field in the transverse plane about the optical axis, assumed to pass through the centroid of the sources. The performance of the device is analyzed using the Cramér-Rao bound applied to the statistics of spatially-unresolved photon counting using photon number-resolving and on-off detectors. The analysis is supported by Monte-Carlo simulations of the maximum likelihood estimator for the source separation, demonstrating the superlocalization effect for separations well below that set by the Rayleigh criterion. Simulations indicating the robustness of SLIVER to mismatch between the optical axis and the centroid are also presented. The results are valid for any imaging system with a circularly symmetric point-spread function.

The ISOPHOT far-infrared serendipity north ecliptic pole minisurvey

NASA Astrophysics Data System (ADS)

Stickel, M.; Bogun, S.; Lemke, D.; Klaas, U.; Toth, L. V.; Herbstmeier, U.; Richter, G.; Assendorp, R.; Laureijs, R.; Kessler, M. F.; Burgdorf, M.; Beichman, C. A.; Rowan-Robinson, M.; Efstathiou, A.

1998-08-01

The ISOPHOT Serendipity Survey fills the otherwise unused slew time between ISO's fine pointings with measurements in an unexplored wavelength regime near 200 microns. In order to test point source extraction software, the completeness of the detected objects as well as the astrophysical content we investigate a 100 sq degr field near the North ecliptic pole, dubbed ISOPHOT Serendipity Minisurvey field. A total of 21 IRAS point sources were detected on the Serendipity slews crossing the field. 19 of these objects are galaxies, one is a planetary nebula and one is an empty field without a bright optical counterpart. The detection completeness is better than 90% for IRAS sources brighter than 2 Jy at 100 microns and better than 80% for sources brighter than 1.5 Jy. The source detection frequency is about 1 per 40degr slew length, in agreement with previous estimations based on galaxy number counts. After the end of the ISO mission, about 4000 point sources are expected to be found in the Serendipity slews. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands and the United Kingdom) and with the participation of ISAS and NASA. Members of the Consortium on the ISOPHOT Serendipity Survey (CISS) are MPIA Heidelberg, ESA ISO SOC Villafranca, AIP Potsdam, IPAC Pasadena, Imperial College London

40 CFR 443.35 - Standards of performance for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Roofing Subcategory § 443.35 Standards of performance for new sources. The...

40 CFR 443.35 - Standards of performance for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PERFORMANCE AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Roofing Subcategory § 443.35 Standards of performance for new sources. The...

40 CFR 424.17 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... control technology. 424.17 Section 424.17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS FERROALLOY MANUFACTURING POINT SOURCE CATEGORY Open Electric... control technology. Except as provided in §§ 125.30 through 125.32, any existing point source subject to...

40 CFR 454.32 - Effluent limitations and guidelines representing the degree of effluent reduction attainable by...

Code of Federal Regulations, 2014 CFR

2014-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GUM AND WOOD CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Wood Rosin, Turpentine and Pine Oil Subcategory § 454.32 Effluent limitations and... manufacture of wood rosin, turpentine and pine oil by a point source subject to the provisions of this...

40 CFR 454.32 - Effluent limitations and guidelines representing the degree of effluent reduction attainable by...

Code of Federal Regulations, 2012 CFR

2012-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GUM AND WOOD CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Wood Rosin, Turpentine and Pine Oil Subcategory § 454.32 Effluent limitations and... manufacture of wood rosin, turpentine and pine oil by a point source subject to the provisions of this...

40 CFR 454.32 - Effluent limitations and guidelines representing the degree of effluent reduction attainable by...

Code of Federal Regulations, 2013 CFR

2013-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GUM AND WOOD CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Wood Rosin, Turpentine and Pine Oil Subcategory § 454.32 Effluent limitations and... manufacture of wood rosin, turpentine and pine oil by a point source subject to the provisions of this...

Meeting the Needs of Travel Clientele: Tried and True Strategies That Work.

ERIC Educational Resources Information Center

Blessing, Kathy; Whitney, Cherine

This paper describes sources for meeting the information needs of travel clientele. Topics addressed include: (1) U.S. government Web sites; (2) collection development tools, including review journals, online bookstores, travel Web sites, and sources of point-by-point comparisons of guide books; (3) prominent guidebook series and publisher Web…

Interim Significant Noncompliance Policy for Clean Water Act Violations Associated with CSOs, SSOs, CAFOs, and Storm Water Point Sources

EPA Pesticide Factsheets

This policy addresses significant noncompliance (SNC) violations associated with combined sewer overflows (CSOs), sanitary sewer overflows (SSOs), concentrated animal feeding operations (CAFOs), and storm water point source discharges covered by the National Pollutant Discharge Elimination System (NPDES) program under the Clean Water Act (CWA).

Bayesian Estimation of Fugitive Methane Point Source Emission Rates from a SingleDownwind High-Frequency Gas Sensor

EPA Science Inventory

Bayesian Estimation of Fugitive Methane Point Source Emission Rates from a Single Downwind High-Frequency Gas Sensor With the tremendous advances in onshore oil and gas exploration and production (E&P) capability comes the realization that new tools are needed to support env...

40 CFR 414.91 - Toxic pollutant effluent limitations and standards for direct discharge point sources that use...

Code of Federal Regulations, 2011 CFR

2011-07-01

... AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Direct Discharge Point Sources That...(k)fluoranthene 59 22 Benzo(a)pyrene 61 23 Bis(2-ethylhexyl) phthalate 279 103 Carbon Tetrachloride... Zinc for Rayon Fiber Manufacture that uses the viscose process and Acrylic Fiber Manufacture that uses...

40 CFR 414.91 - Toxic pollutant effluent limitations and standards for direct discharge point sources that use...

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Direct Discharge Point Sources That...(k)fluoranthene 59 22 Benzo(a)pyrene 61 23 Bis(2-ethylhexyl) phthalate 279 103 Carbon Tetrachloride... Zinc for Rayon Fiber Manufacture that uses the viscose process and Acrylic Fiber Manufacture that uses...

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...

22 CFR 201.63 - Maximum prices for commodities.

Code of Federal Regulations, 2010 CFR

2010-04-01

... actually incurred in moving the commodities supplied from the point of purchase to a position alongside or... between those points. (g) Commodity price subject to escalation. If a purchase contract contains a price.... prevailing market price—U.S. source. The purchase price for a commodity, the source of which is the United...

40 CFR 424.17 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... control technology. 424.17 Section 424.17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS FERROALLOY MANUFACTURING POINT SOURCE CATEGORY Open Electric... control technology. Except as provided in §§ 125.30 through 125.32, any existing point source subject to...

40 CFR 424.17 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... control technology. 424.17 Section 424.17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS FERROALLOY MANUFACTURING POINT SOURCE CATEGORY Open Electric... control technology. Except as provided in §§ 125.30 through 125.32, any existing point source subject to...

40 CFR 424.17 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... control technology. 424.17 Section 424.17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS FERROALLOY MANUFACTURING POINT SOURCE CATEGORY Open Electric... control technology. Except as provided in §§ 125.30 through 125.32, any existing point source subject to...

40 CFR 424.17 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... control technology. 424.17 Section 424.17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS FERROALLOY MANUFACTURING POINT SOURCE CATEGORY Open Electric... control technology. Except as provided in §§ 125.30 through 125.32, any existing point source subject to...

PHOTOCHEMICAL SIMULATIONS OF POINT SOURCE EMISSIONS WITH THE MODELS-3 CMAQ PLUME-IN-GRID APPROACH

EPA Science Inventory

A plume-in-grid (PinG) approach has been designed to provide a realistic treatment for the simulation the dynamic and chemical processes impacting pollutant species in major point source plumes during a subgrid scale phase within an Eulerian grid modeling framework. The PinG sci...

77 FR 19282 - Draft NPDES General Permit for Discharges From the Oil and Gas Extraction Point Source Category...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-30

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9650-8] Draft NPDES General Permit for Discharges From the Oil and Gas Extraction Point Source Category to Coastal Waters in Texas (TXG330000) AGENCY: Environmental Protection Agency (EPA). ACTION: Proposal of NPDES General Permit Renewal. SUMMARY: EPA Region 6...

Estimation of point source fugitive emission rates from a single sensor time series: a conditionally-sampled Gaussian plume reconstruction

EPA Science Inventory

This paper presents a technique for determining the trace gas emission rate from a point source. The technique was tested using data from controlled methane release experiments and from measurement downwind of a natural gas production facility in Wyoming. Concentration measuremen...

Refining models for quantifying the water quality benefits of improved animal management for use in water quality trading

USDA-ARS?s Scientific Manuscript database

Water quality trading (WQT) is a market-based approach that allows point sources of water pollution to meet their water quality obligations by purchasing credits from the reduced discharges from other point or nonpoint sources. Non-permitted animal operations and fields of permitted animal operatio...

Illusion induced overlapped optics.

PubMed

Zang, XiaoFei; Shi, Cheng; Li, Zhou; Chen, Lin; Cai, Bin; Zhu, YiMing; Zhu, HaiBin

2014-01-13

The traditional transformation-based cloak seems like it can only hide objects by bending the incident electromagnetic waves around the hidden region. In this paper, we prove that invisible cloaks can be applied to realize the overlapped optics. No matter how many in-phase point sources are located in the hidden region, all of them can overlap each other (this can be considered as illusion effect), leading to the perfect optical interference effect. In addition, a singular parameter-independent cloak is also designed to obtain quasi-overlapped optics. Even more amazing of overlapped optics is that if N identical separated in-phase point sources covered with the illusion media, the total power outside the transformation region is N2I0 (not NI0) (I0 is the power of just one point source, and N is the number point sources), which seems violating the law of conservation of energy. A theoretical model based on interference effect is proposed to interpret the total power of these two kinds of overlapped optics effects. Our investigation may have wide applications in high power coherent laser beams, and multiple laser diodes, and so on.

Advanced Unstructured Grid Generation for Complex Aerodynamic Applications

NASA Technical Reports Server (NTRS)

Pirzadeh, Shahyar Z.

2008-01-01

A new approach for distribution of grid points on the surface and in the volume has been developed and implemented in the NASA unstructured grid generation code VGRID. In addition to the point and line sources of prior work, the new approach utilizes surface and volume sources for automatic curvature-based grid sizing and convenient point distribution in the volume. A new exponential growth function produces smoother and more efficient grids and provides superior control over distribution of grid points in the field. All types of sources support anisotropic grid stretching which not only improves the grid economy but also provides more accurate solutions for certain aerodynamic applications. The new approach does not require a three-dimensional background grid as in the previous methods. Instead, it makes use of an efficient bounding-box auxiliary medium for storing grid parameters defined by surface sources. The new approach is less memory-intensive and more efficient computationally. The grids generated with the new method either eliminate the need for adaptive grid refinement for certain class of problems or provide high quality initial grids that would enhance the performance of many adaptation methods.

Advanced Unstructured Grid Generation for Complex Aerodynamic Applications

NASA Technical Reports Server (NTRS)

Pirzadeh, Shahyar

2010-01-01

A new approach for distribution of grid points on the surface and in the volume has been developed. In addition to the point and line sources of prior work, the new approach utilizes surface and volume sources for automatic curvature-based grid sizing and convenient point distribution in the volume. A new exponential growth function produces smoother and more efficient grids and provides superior control over distribution of grid points in the field. All types of sources support anisotropic grid stretching which not only improves the grid economy but also provides more accurate solutions for certain aerodynamic applications. The new approach does not require a three-dimensional background grid as in the previous methods. Instead, it makes use of an efficient bounding-box auxiliary medium for storing grid parameters defined by surface sources. The new approach is less memory-intensive and more efficient computationally. The grids generated with the new method either eliminate the need for adaptive grid refinement for certain class of problems or provide high quality initial grids that would enhance the performance of many adaptation methods.

Strategy for Texture Management in Metals Additive Manufacturing

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

Kirka, Michael M.; Lee, Yousub; Greeley, Duncan A.

Additive manufacturing (AM) technologies have long been recognized for their ability to fabricate complex geometric components directly from models conceptualized through computers, allowing for complicated designs and assemblies to be fabricated at lower costs, with shorter time to market, and improved function. Lacking behind the design complexity aspect is the ability to fully exploit AM processes for control over texture within AM components. Currently, standard heat-fill strategies utilized in AM processes result in largely columnar grain structures. Here, we propose a point heat source fill for the electron beam melting (EBM) process through which the texture in AM materials canmore » be controlled. Using this point heat source strategy, the ability to form either columnar or equiaxed grain structures upon solidification through changes in the process parameters associated with the point heat source fill is demonstrated for the nickel-base superalloy, Inconel 718. Mechanically, the material is demonstrated to exhibit either anisotropic properties for the columnar-grained material fabricated through using the standard raster scan of the EBM process or isotropic properties for the equiaxed material fabricated using the point heat source fill.« less

Strategy for Texture Management in Metals Additive Manufacturing

DOE PAGES

Kirka, Michael M.; Lee, Yousub; Greeley, Duncan A.; ...

2017-01-31

Additive manufacturing (AM) technologies have long been recognized for their ability to fabricate complex geometric components directly from models conceptualized through computers, allowing for complicated designs and assemblies to be fabricated at lower costs, with shorter time to market, and improved function. Lacking behind the design complexity aspect is the ability to fully exploit AM processes for control over texture within AM components. Currently, standard heat-fill strategies utilized in AM processes result in largely columnar grain structures. Here, we propose a point heat source fill for the electron beam melting (EBM) process through which the texture in AM materials canmore » be controlled. Using this point heat source strategy, the ability to form either columnar or equiaxed grain structures upon solidification through changes in the process parameters associated with the point heat source fill is demonstrated for the nickel-base superalloy, Inconel 718. Mechanically, the material is demonstrated to exhibit either anisotropic properties for the columnar-grained material fabricated through using the standard raster scan of the EBM process or isotropic properties for the equiaxed material fabricated using the point heat source fill.« less

A Northern Sky Survey for Point-like Sources of EeV Neutral Particles with the Telescope Array Experiment

NASA Astrophysics Data System (ADS)

Abbasi, R. U.; Abe, M.; Abu-Zayyad, T.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, T.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, K.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzawa, T.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

2015-05-01

We report on the search for steady point-like sources of neutral particles around 1018 eV between 2008 and 2013 May with the scintillator SD of the Telescope Array experiment. We found overall no significant point-like excess above 0.5 EeV in the northern sky. Subsequently, we also searched for coincidence with the Fermi bright Galactic sources. No significant coincidence was found within the statistical uncertainty. Hence, we set an upper limit on the neutron flux that corresponds to an averaged flux of 0.07 km-2 yr-1 for E\\gt 1 EeV in the northern sky at the 95% confidence level. This is the most stringent flux upper limit in a northern sky survey assuming point-like sources. The upper limit at the 95% confidence level on the neutron flux from Cygnus X-3 is also set to 0.2 km-2 yr-1 for E\\gt 0.5 EeV. This is an order of magnitude lower than previous flux measurements.

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.

Advanced Optimal Extraction for the Spitzer/IRS

NASA Astrophysics Data System (ADS)

Lebouteiller, V.; Bernard-Salas, J.; Sloan, G. C.; Barry, D. J.

2010-02-01

We present new advances in the spectral extraction of pointlike sources adapted to the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope. For the first time, we created a supersampled point-spread function of the low-resolution modules. We describe how to use the point-spread function to perform optimal extraction of a single source and of multiple sources within the slit. We also examine the case of the optimal extraction of one or several sources with a complex background. The new algorithms are gathered in a plug-in called AdOpt which is part of the SMART data analysis software.

Point-like neutron source based on high-current electron cyclotron resonance ion source with powerful millimeter wave plasma heating

NASA Astrophysics Data System (ADS)

Golubev, S. V.; Skalyga, V. A.; Izotov, I. V.; Sidorov, A. V.

2018-01-01

A possibility of an intense deuterium ion beam creation for a compact powerful point-like neutron source is discussed. The fusion takes place due to bombardment of deuterium (or tritium) loaded target by high-current focused deuterium ion beam with energy of 100 keV. The ways of high-current and low emittance ion beam formation from the plasma of quasi-gasdynamic ion source of a new generation based on an electron cyclotron resonance discharge in an open magnetic trap sustained by powerful microwave radiation are investigated.

Search for ultra high energy gamma-rays from various sources

NASA Technical Reports Server (NTRS)

Dzikowski, T.; Gawin, J.; Grochalska, B.; Korejwo, J.; Wdowczyk, J.

1985-01-01

The hypothesis that there exists an excess of showers from the Galactic plane on the level 1 to 2% at energies just above 10 to the 16th power eV is explored. The excess shower from the Galactic plane seems to be very similar in properties to excess showers from the point sources/flat spectrum, deficit of low energy muons. Those facts suggest that the excess from the Galactic plane are probably due to summing up of the contribution from individual point sources. That in turn suggest that those sources are rather numerous.

Geolocation and Pointing Accuracy Analysis for the WindSat Sensor

NASA Technical Reports Server (NTRS)

Meissner, Thomas; Wentz, Frank J.; Purdy, William E.; Gaiser, Peter W.; Poe, Gene; Uliana, Enzo A.

2006-01-01

Geolocation and pointing accuracy analyses of the WindSat flight data are presented. The two topics were intertwined in the flight data analysis and will be addressed together. WindSat has no unusual geolocation requirements relative to other sensors, but its beam pointing knowledge accuracy is especially critical to support accurate polarimetric radiometry. Pointing accuracy was improved and verified using geolocation analysis in conjunction with scan bias analysis. nvo methods were needed to properly identify and differentiate between data time tagging and pointing knowledge errors. Matchups comparing coastlines indicated in imagery data with their known geographic locations were used to identify geolocation errors. These coastline matchups showed possible pointing errors with ambiguities as to the true source of the errors. Scan bias analysis of U, the third Stokes parameter, and of vertical and horizontal polarizations provided measurement of pointing offsets resolving ambiguities in the coastline matchup analysis. Several geolocation and pointing bias sources were incfementally eliminated resulting in pointing knowledge and geolocation accuracy that met all design requirements.

Search for point sources of high energy neutrinos with final data from AMANDA-II

NASA Astrophysics Data System (ADS)

Abbasi, R.; Ackermann, M.; Adams, J.; Ahlers, M.; Ahrens, J.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Baret, B.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Becka, T.; Becker, J. K.; Becker, K.-H.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Blaufuss, E.; Boersma, D. J.; Bohm, C.; Bolmont, J.; Böser, S.; Botner, O.; Braun, J.; Breder, D.; Burgess, T.; Castermans, T.; Chirkin, D.; Christy, B.; Clem, J.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; Davour, A.; Day, C. T.; Depaepe, O.; de Clercq, C.; Demirörs, L.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; De Young, T.; Diaz-Velez, J. C.; Dreyer, J.; Dumm, J. P.; Duvoort, M. R.; Edwards, W. R.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Filimonov, K.; Finley, C.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Ganugapati, R.; Gerhardt, L.; Gladstone, L.; Goldschmidt, A.; Goodman, J. A.; Gozzini, R.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gunasingha, R. M.; Gurtner, M.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Hardtke, R.; Hasegawa, Y.; Heise, J.; Helbing, K.; Hellwig, M.; Herquet, P.; Hickford, S.; Hill, G. C.; Hodges, J.; Hoffman, K. D.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hughey, B.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hundertmark, S.; Hussain, S.; Imlay, R. L.; Inaba, M.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kawai, H.; Kelley, J. L.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Klepser, S.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Kuehn, K.; Kuwabara, T.; Labare, M.; Laihem, K.; Landsman, H.; Lauer, R.; Leich, H.; Leier, D.; Lewis, C.; Lucke, A.; Lundberg, J.; Lünemann, J.; Madsen, J.; Maruyama, R.; Mase, K.; Matis, H. S.; McParland, C. P.; Meagher, K.; Meli, A.; Merck, M.; Messarius, T.; Mészáros, P.; Miyamoto, H.; Mohr, A.; Montaruli, T.; Morse, R.; Movit, S. M.; Münich, K.; Nahnhauer, R.; Nam, J. W.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; Ono, M.; Panknin, S.; Patton, S.; Pérez de Los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Pohl, A. C.; Porrata, R.; Potthoff, N.; Pretz, J.; Price, P. B.; Przybylski, G. T.; Rawlins, K.; Razzaque, S.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Robbins, W. J.; Rodriguez, J.; Roth, P.; Rothmaier, F.; Rott, C.; Roucelle, C.; Rutledge, D.; Ryckbosch, D.; Sander, H.-G.; Sarkar, S.; Satalecka, K.; Schlenstedt, S.; Schmidt, T.; Schneider, D.; Schultz, O.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Smith, A. J.; Song, C.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stezelberger, T.; Stokstad, R. G.; Stoufer, M. C.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Sulanke, K.-H.; Sullivan, G. W.; Swillens, Q.; Taboada, I.; Tarasova, O.; Tepe, A.; Ter-Antonyan, S.; Tilav, S.; Tluczykont, M.; Toale, P. A.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; van Overloop, A.; Viscomi, V.; Vogt, C.; Voigt, B.; Walck, C.; Waldenmaier, T.; Walter, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebusch, C. H.; Wiedemann, C.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Xu, X. W.; Yodh, G.; Yoshida, S.

2009-03-01

We present a search for point sources of high energy neutrinos using 3.8 yr of data recorded by AMANDA-II during 2000-2006. After reconstructing muon tracks and applying selection criteria designed to optimally retain neutrino-induced events originating in the northern sky, we arrive at a sample of 6595 candidate events, predominantly from atmospheric neutrinos with primary energy 100 GeV to 8 TeV. Our search of this sample reveals no indications of a neutrino point source. We place the most stringent limits to date on E-2 neutrino fluxes from points in the northern sky, with an average upper limit of E2Φνμ+ντ≤5.2×10-11TeVcm-2s-1 on the sum of νμ and ντ fluxes, assumed equal, over the energy range from 1.9 TeV to 2.5 PeV.

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.

Proposal on a sustainable strategy to avoid point source pollution of water with plant protection products.

PubMed

Mestdagh, Inge; Bonicelli, Bernard; Laplana, Ramon; Roettele, Manfred

2009-01-01

Based on the results and lessons learned from the TOPPS project (Training the Operators to prevent Pollution from Point Sources), a proposal on a sustainable strategy to avoid point source pollution from Plant Protection Products (PPPs) was made. Within this TOPPS project (2005-2008), stakeholders were interviewed and research and analysis were done in 6 pilot catchment areas (BE, FR, DE, DK, IT, PL). Next, there was a repeated survey on operators' perception and opinion to measure changes resulting from TOPPS activities and good and bad practices were defined based on the Best Management Practices (risk analysis). Aim of the proposal is to suggest a strategy considering the differences between countries which can be implemented on Member State level in order to avoid PPP pollution of water through point sources. The methodology used for the up-scaLing proposal consists of the analysis of the current situation, a gap analysis, a consistency analysis and organisational structures for implementation. The up-scaling proposal focuses on the behaviour of the operators, on the equipment and infrastructure available with the operators. The proposal defines implementation structures to support correct behaviour through the development and updating of Best Management Practices (BMPs) and through the transfer and the implementation of these BMPs. Next, the proposal also defines requirements for the improvement of equipment and infrastructure based on the defined key factors related to point source pollution. It also contains cost estimates for technical and infrastructure upgrades to comply with BMPs.

[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.

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.

Outdoor air pollution in close proximity to a continuous point source

NASA Astrophysics Data System (ADS)

Klepeis, Neil E.; Gabel, Etienne B.; Ott, Wayne R.; Switzer, Paul

Data are lacking on human exposure to air pollutants occurring in ground-level outdoor environments within a few meters of point sources. To better understand outdoor exposure to tobacco smoke from cigarettes or cigars, and exposure to other types of outdoor point sources, we performed more than 100 controlled outdoor monitoring experiments on a backyard residential patio in which we released pure carbon monoxide (CO) as a tracer gas for continuous time periods lasting 0.5-2 h. The CO was emitted from a single outlet at a fixed per-experiment rate of 120-400 cc min -1 (˜140-450 mg min -1). We measured CO concentrations every 15 s at up to 36 points around the source along orthogonal axes. The CO sensors were positioned at standing or sitting breathing heights of 2-5 ft (up to 1.5 ft above and below the source) and at horizontal distances of 0.25-2 m. We simultaneously measured real-time air speed, wind direction, relative humidity, and temperature at single points on the patio. The ground-level air speeds on the patio were similar to those we measured during a survey of 26 outdoor patio locations in 5 nearby towns. The CO data exhibited a well-defined proximity effect similar to the indoor proximity effect reported in the literature. Average concentrations were approximately inversely proportional to distance. Average CO levels were approximately proportional to source strength, supporting generalization of our results to different source strengths. For example, we predict a cigarette smoker would cause average fine particle levels of approximately 70-110 μg m -3 at horizontal distances of 0.25-0.5 m. We also found that average CO concentrations rose significantly as average air speed decreased. We fit a multiplicative regression model to the empirical data that predicts outdoor concentrations as a function of source emission rate, source-receptor distance, air speed and wind direction. The model described the data reasonably well, accounting for ˜50% of the log-CO variability in 5-min CO concentrations.

Fecal contamination of drinking water within peri-urban households, Lima, Peru.

PubMed

Oswald, William E; Lescano, Andrés G; Bern, Caryn; Calderon, Maritza M; Cabrera, Lilia; Gilman, Robert H

2007-10-01

We assessed fecal contamination of drinking water in households in 2 peri-urban communities of Lima, Peru. We measured Escherichia coli counts in municipal source water and, within households, water from principal storage containers, stored boiled drinking water, and water in a serving cup. Source water was microbiologically clean, but 26 (28%) of 93 samples of water stored for cooking had fecal contamination. Twenty-seven (30%) of 91 stored boiled drinking water samples grew E. coli. Boiled water was more frequently contaminated when served in a drinking cup than when stored (P < 0.01). Post-source contamination increased successively through the steps of usage from source water to the point of consumption. Boiling failed to ensure safe drinking water at the point of consumption because of easily contaminated containers and poor domestic hygiene. Hygiene education, better point-of-use treatment and storage options, and in-house water connections are urgently needed.

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.

Correcting the extended-source calibration for the Herschel-SPIRE Fourier-transform spectrometer

NASA Astrophysics Data System (ADS)

Valtchanov, I.; Hopwood, R.; Bendo, G.; Benson, C.; Conversi, L.; Fulton, T.; Griffin, M. J.; Joubaud, T.; Lim, T.; Lu, N.; Marchili, N.; Makiwa, G.; Meyer, R. A.; Naylor, D. A.; North, C.; Papageorgiou, A.; Pearson, C.; Polehampton, E. T.; Scott, J.; Schulz, B.; Spencer, L. D.; van der Wiel, M. H. D.; Wu, R.

2018-03-01

We describe an update to the Herschel-Spectral and Photometric Imaging Receiver (SPIRE) Fourier-transform spectrometer (FTS) calibration for extended sources, which incorporates a correction for the frequency-dependent far-field feedhorn efficiency, ηff. This significant correction affects all FTS extended-source calibrated spectra in sparse or mapping mode, regardless of the spectral resolution. Line fluxes and continuum levels are underestimated by factors of 1.3-2 in thespectrometer long wavelength band (447-1018 GHz; 671-294 μm) and 1.4-1.5 in the spectrometer short wavelength band (944-1568 GHz; 318-191 μm). The correction was implemented in the FTS pipeline version 14.1 and has also been described in the SPIRE Handbook since 2017 February. Studies based on extended-source calibrated spectra produced prior to this pipeline version should be critically reconsidered using the current products available in the Herschel Science Archive. Once the extended-source calibrated spectra are corrected for ηff, the synthetic photometry and the broad-band intensities from SPIRE photometer maps agree within 2-4 per cent - similar levels to the comparison of point-source calibrated spectra and photometry from point-source calibrated maps. The two calibration schemes for the FTS are now self-consistent: the conversion between the corrected extended-source and point-source calibrated spectra can be achieved with the beam solid angle and a gain correction that accounts for the diffraction loss.

The feasibility of effluent trading in the energy industries

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

Veil, J.A.

1997-05-01

In January 1996, the U.S. Environmental Protection Agency (EPA) released a policy statement endorsing effluent trading in watersheds, hoping to spur additional interest in the subject. The policy describes five types of effluent trades - point source/point source, point source/nonpoint source, pretreatment, intraplant, and nonpoint source/nonpoint source. This report evaluates the feasibility of effluent trading for facilities in the oil and gas industry (exploration and production, refining, and distribution and marketing segments), electric power industry, and the coal industry (mines and preparation plants). Nonpoint source/nonpoint source trades are not considered since the energy industry facilities evaluated here are all pointmore » sources. EPA has administered emission trading programs in its air quality program for many years. Programs for offsets, bubbles, banking, and netting are supported by federal regulations, and the 1990 Clean Air Act (CAA) amendments provide a statutory basis for trading programs to control ozone and acid rain. Different programs have had varying degrees of success, but few have come close to meeting their expectations. Few trading programs have been established under the Clean Water Act (CWA). One intraplant trading program was established by EPA in its effluent limitation guidelines (ELGs) for the iron and steel industry. The other existing effluent trading programs were established by state or local governments and have had minimal success.« less

The Wilkinson Microwave Anisotropy Probe (WMAP) Source Catalog

NASA Technical Reports Server (NTRS)

Wright, E.L.; Chen, X.; Odegard, N.; Bennett, C.L.; Hill, R.S.; Hinshaw, G.; Jarosik, N.; Komatsu, E.; Nolta, M.R.; Page, L.;

The neutral current sheet and its radiation pairs of side sources in coronal mass ejections

NASA Astrophysics Data System (ADS)

Ji, Shu-Chen

Using the data observed with the soft X-ray telescope, hard X-ray telescope aboard on Yohkoh and the Nobeyama Radioheliograph on 1998 April 23, a comprehensive study on soft X-ray coronal mass ejection (SXRCME) and radio Type IV burst is carried out and some significant results are obtained as follows: A magnetic capacity belt (MCB) between two magnetic dipole sources (MDSs) was found and there were only a few activitation sources (ASs). During the MCB changed into a magnetic energy belt (MEB) by the ASs, activating energy and shining material both concentrated to the neutral current sheet (NCS) in the course of its formation. When two MDSs were put through by the MEB, the NCS formed and the SXRCME occurred. The matter ejected not only from the NCS, but also from the whole MEB. The expanding loop of the SXRCME had two foot points, both were just two MDSs. The head of the expanding loop always tended to the foot point of the weak source, because it was equilibrium point of magnetic pressures coming from two foot points. For this reason, its locus was neutral line. From this, the neutral line can also determine the position of NCS. Finally, the radiation pairs of side sources of NCS on the MEB are found.

Exploring Cryogenic Focused Ion Beam Milling as a Group III-V Device Fabrication Tool

DTIC Science & Technology

2013-09-01

boiling, triple , and critical points of the elements” in CRC Handbook of Chemistry and Physics, 92nd ed., Boca Raton, FL: CRC press, 2011-2012, p. 4...The most widely used ion source in FIB instruments is a gallium (Ga) liquid metal ion source (LMIS) [4]. Gallium is attractive as an ion source...Figure 3b. EDS spectra were captured at different points across the patterned region of the room temperature milled sample, as indicated in Figure 4

Point Source X-Ray Lithography System for Sub-0.15 Micron Design Rules

DTIC Science & Technology

1998-05-22

consist of a SAL developed stepper, an SRL developed Dense Plasma Focus , (DPF), X-Ray source, and a CXrL developed beam line. The system will be...existing machine that used spark gap switching, SRL has developed an all solid state driver and improved head electrode assembly for their dense plasma ... focus X-Ray source. Likewise, SAL has used their existing Model 4 stepper installed at CXrL as a design starting point, and has developed an advanced

40 CFR 415.426 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2012 CFR

2012-07-01

...) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Hydrogen Cyanide... Sources (PSNS): Subpart AP—Hydrogen Cyanide Pollutant or pollutant property PSNS effluent limitations...

40 CFR 415.426 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Hydrogen Cyanide... Sources (PSNS): Subpart AP—Hydrogen Cyanide Pollutant or pollutant property PSNS effluent limitations...

40 CFR 415.425 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Hydrogen Cyanide Production... achieve the following new source performance standards (NSPS): Subpart AP—Hydrogen Cyanide Pollutant or...

40 CFR 415.425 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Hydrogen Cyanide Production... achieve the following new source performance standards (NSPS): Subpart AP—Hydrogen Cyanide Pollutant or...

40 CFR 415.425 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Hydrogen Cyanide Production... achieve the following new source performance standards (NSPS): Subpart AP—Hydrogen Cyanide Pollutant or...

40 CFR 415.426 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

...) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Hydrogen Cyanide... Sources (PSNS): Subpart AP—Hydrogen Cyanide Pollutant or pollutant property PSNS effluent limitations...

40 CFR 415.426 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Hydrogen Cyanide... Sources (PSNS): Subpart AP—Hydrogen Cyanide Pollutant or pollutant property PSNS effluent limitations...

40 CFR 415.425 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Hydrogen Cyanide Production... achieve the following new source performance standards (NSPS): Subpart AP—Hydrogen Cyanide Pollutant or...

40 CFR 415.425 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Hydrogen Cyanide Production... achieve the following new source performance standards (NSPS): Subpart AP—Hydrogen Cyanide Pollutant or...

40 CFR 421.65 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Copper... existing sources. The mass of wastewater pollutants in secondary copper process wastewater introduced into...

40 CFR 421.65 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Secondary Copper... existing sources. The mass of wastewater pollutants in secondary copper process wastewater introduced into...

Selective Listening Point Audio Based on Blind Signal Separation and Stereophonic Technology

NASA Astrophysics Data System (ADS)

Niwa, Kenta; Nishino, Takanori; Takeda, Kazuya

A sound field reproduction method is proposed that uses blind source separation and a head-related transfer function. In the proposed system, multichannel acoustic signals captured at distant microphones are decomposed to a set of location/signal pairs of virtual sound sources based on frequency-domain independent component analysis. After estimating the locations and the signals of the virtual sources by convolving the controlled acoustic transfer functions with each signal, the spatial sound is constructed at the selected point. In experiments, a sound field made by six sound sources is captured using 48 distant microphones and decomposed into sets of virtual sound sources. Since subjective evaluation shows no significant difference between natural and reconstructed sound when six virtual sources and are used, the effectiveness of the decomposing algorithm as well as the virtual source representation are confirmed.

Methane Flux Estimation from Point Sources using GOSAT Target Observation: Detection Limit and Improvements with Next Generation Instruments

NASA Astrophysics Data System (ADS)

Kuze, A.; Suto, H.; Kataoka, F.; Shiomi, K.; Kondo, Y.; Crisp, D.; Butz, A.

2017-12-01

Atmospheric methane (CH4) has an important role in global radiative forcing of climate but its emission estimates have larger uncertainties than carbon dioxide (CO2). The area of anthropogenic emission sources is usually much smaller than 100 km2. The Thermal And Near infrared Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS) onboard the Greenhouse gases Observing SATellite (GOSAT) has measured CO2 and CH4 column density using sun light reflected from the earth's surface. It has an agile pointing system and its footprint can cover 87-km2 with a single detector. By specifying pointing angles and observation time for every orbit, TANSO-FTS can target various CH4 point sources together with reference points every 3 day over years. We selected a reference point that represents CH4 background density before or after targeting a point source. By combining satellite-measured enhancement of the CH4 column density and surface measured wind data or estimates from the Weather Research and Forecasting (WRF) model, we estimated CH4emission amounts. Here, we picked up two sites in the US West Coast, where clear sky frequency is high and a series of data are available. The natural gas leak at Aliso Canyon showed a large enhancement and its decrease with time since the initial blowout. We present time series of flux estimation assuming the source is single point without influx. The observation of the cattle feedlot in Chino, California has weather station within the TANSO-FTS footprint. The wind speed is monitored continuously and the wind direction is stable at the time of GOSAT overpass. The large TANSO-FTS footprint and strong wind decreases enhancement below noise level. Weak wind shows enhancements in CH4, but the velocity data have large uncertainties. We show the detection limit of single samples and how to reduce uncertainty using time series of satellite data. We will propose that the next generation instruments for accurate anthropogenic CO2 and CH4 flux estimation have improve spatial resolution (˜1km2 ) to further enhance column density changes. We also propose adding imaging capability to monitor plume orientation. We will present laboratory model results and a sampling pattern optimization study that combines local emission source and global survey observations.

The gamma ray continuum spectrum from the galactic center disk and point sources

NASA Technical Reports Server (NTRS)

Gehrels, Neil; Tueller, Jack

1992-01-01

A light curve of gamma-ray continuum emission from point sources in the galactic center region is generated from balloon and satellite observations made over the past 25 years. The emphasis is on the wide field-of-view instruments which measure the combined flux from all sources within approximately 20 degrees of the center. These data have not been previously used for point-source analyses because of the unknown contribution from diffuse disk emission. In this study, the galactic disk component is estimated from observations made by the Gamma Ray Imaging Spectrometer (GRIS) instrument in Oct. 1988. Surprisingly, there are several times during the past 25 years when all gamma-ray sources (at 100 keV) within about 20 degrees of the galactic center are turned off or are in low emission states. This implies that the sources are all variable and few in number. The continuum gamma-ray emission below approximately 150 keV from the black hole candidate 1E1740.7-2942 is seen to turn off in May 1989 on a time scale of less than two weeks, significantly shorter than ever seen before. With the continuum below 150 keV turned off, the spectral shape derived from the HEXAGONE observation on 22 May 1989 is very peculiar with a peak near 200 keV. This source was probably in its normal state for more than half of all observations since the mid-1960's. There are only two observations (in 1977 and 1979) for which the sum flux from the point sources in the region significantly exceeds that from 1E1740.7-2942 in its normal state.

The Spitzer-IRAC Point-source Catalog of the Vela-D Cloud

NASA Astrophysics Data System (ADS)

Strafella, F.; Elia, D.; Campeggio, L.; Giannini, T.; Lorenzetti, D.; Marengo, M.; Smith, H. A.; Fazio, G.; De Luca, M.; Massi, F.

2010-08-01

This paper presents the observations of Cloud D in the Vela Molecular Ridge, obtained with the Infrared Array Camera (IRAC) camera on board the Spitzer Space Telescope at the wavelengths λ = 3.6, 4.5, 5.8, and 8.0 μm. A photometric catalog of point sources, covering a field of approximately 1.2 deg2, has been extracted and complemented with additional available observational data in the millimeter region. Previous observations of the same region, obtained with the Spitzer MIPS camera in the photometric bands at 24 μm and 70 μm, have also been reconsidered to allow an estimate of the spectral slope of the sources in a wider spectral range. A total of 170,299 point sources, detected at the 5σ sensitivity level in at least one of the IRAC bands, have been reported in the catalog. There were 8796 sources for which good quality photometry was obtained in all four IRAC bands. For this sample, a preliminary characterization of the young stellar population based on the determination of spectral slope is discussed; combining this with diagnostics in the color-magnitude and color-color diagrams, the relative population of young stellar objects (YSOs) in different evolutionary classes has been estimated and a total of 637 candidate YSOs have been selected. The main differences in their relative abundances have been highlighted and a brief account for their spatial distribution is given. The star formation rate has also been estimated and compared with the values derived for other star-forming regions. Finally, an analysis of the spatial distribution of the sources by means of the two-point correlation function shows that the younger population, constituted by the Class I and flat-spectrum sources, is significantly more clustered than the Class II and III sources.

Answering questions at the point of care: do residents practice EBM or manage information sources?

PubMed

McCord, Gary; Smucker, William D; Selius, Brian A; Hannan, Scott; Davidson, Elliot; Schrop, Susan Labuda; Rao, Vinod; Albrecht, Paula

2007-03-01

To determine the types of information sources that evidence-based medicine (EBM)-trained, family medicine residents use to answer clinical questions at the point of care, to assess whether the sources are evidence-based, and to provide suggestions for more effective information-management strategies in residency training. In 2005, trained medical students directly observed (for two half-days per physician) how 25 third-year family medicine residents retrieved information to answer clinical questions arising at the point of care and documented the type and name of each source, the retrieval location, and the estimated time spent consulting the source. An end-of-study questionnaire asked 37 full-time faculty and the participating residents about the best information sources available, subscriptions owned, why they use a personal digital assistant (PDA) to practice medicine, and their experience in preventing medical errors using a PDA. Forty-four percent of questions were answered by attending physicians, 23% by consulting PDAs, and 20% from books. Seventy-two percent of questions were answered within two minutes. Residents rated UptoDate as the best source for evidence-based information, but they used this source only five times. PDAs were used because of ease of use, time factors, and accessibility. All examples of medical errors discovered or prevented with PDA programs were medication related. None of the participants' residencies required the use of a specific medical information resource. The results support the Agency for Health Care Research and Quality's call for medical system improvements at the point of care. Additionally, it may be necessary to teach residents better information-management skills in addition to EBM skills.

40 CFR 415.24 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2012 CFR

2012-07-01

...) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Aluminum Sulfate... standards for existing sources (PSES): Subpart B—Aluminum Sulfate Pollutant or pollutant property PSES...

40 CFR 415.24 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

...) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Aluminum Sulfate... standards for existing sources (PSES): Subpart B—Aluminum Sulfate Pollutant or pollutant property PSES...

40 CFR 415.24 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Aluminum Sulfate... standards for existing sources (PSES): Subpart B—Aluminum Sulfate Pollutant or pollutant property PSES...

40 CFR 407.74 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE CATEGORY Canned and Preserved Vegetables Subcategory § 407.74 Pretreatment standards for existing sources...

40 CFR 415.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Aluminum Chloride... standards for existing sources (PSES): Subpart A—Aluminum Chloride Pollutant or pollutant property PSES...

The strong UV source in the active E Galaxy NGC 4552

NASA Technical Reports Server (NTRS)

Oconnell, R. W.; Thuan, T. X.; Puschell, J. J.

1986-01-01

1200-3200 A IUE spectra of the nucleus of NGC 4552 (M89) were obtained in order to investigate the nature of the strong 10 micron source in this Galaxy. There is a strong, extended UV source in NGC 4552 which has a spatial distribution nearly identical with that at optical wavelengths and is undoubedly stellar in origin. Its properties are consistent with the correlation between UV source strength and metallicity pointed out by Faber (1983). There is no evidence for a nonthermal point source in the UV. It appears unlikely that the 10 micron emission is from heated dust grains. Instead, it is believed the 10 micron radiation is nonthermal in origin, implying a remarkably small size of only 0.1 AU for this source.

[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.

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...

Point Sources of Emerging Contaminants Along the Colorado River Basin: Impact on Water Use and Reuse in the Arid Southwest

EPA Science Inventory

Emerging contaminants (ECs) (e.g., pharmaceuticals, illicit drugs, personal care products) have been detected in waters across the United States. The objective of this study was to evaluate point sources of ECs along the Colorado River, from the headwaters in Colorado to the Gulf...

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...

40 CFR 414.101 - Toxic pollutant effluent limitations and standards for direct discharge point sources that do not...

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Direct Discharge Point Sources...(k)fluoranthene 47 19 Benzo(a)pyrene 48 20 Bis(2-ethylhexyl) phthalate 258 95 Carbon Tetrachloride... micrograms per liter. 2 Total Zinc for Rayon Fiber Manufacture that uses the viscose process and Acrylic...

40 CFR 414.101 - Toxic pollutant effluent limitations and standards for direct discharge point sources that do not...

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Direct Discharge Point Sources...(k)fluoranthene 47 19 Benzo(a)pyrene 48 20 Bis(2-ethylhexyl) phthalate 258 95 Carbon Tetrachloride... micrograms per liter. 2 Total Zinc for Rayon Fiber Manufacture that uses the viscose process and Acrylic...

22 CFR 201.64 - Application of the price rules to commodities.

Code of Federal Regulations, 2010 CFR

2010-04-01

... purchase price of a commodity exceeds the price in comparable export sales or in comparable domestic sales... addition to the price of the commodity at an internal point in the source country, transportation from that point to the port of export in the source country, and to the extent not already included in the price...

40 CFR 435.14 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS OIL AND GAS EXTRACTION POINT SOURCE CATEGORY Offshore... 40 CFR 125.30-32, any existing point source subject to this subpart must achieve the following... Minimum of 1 mg/l and maintained as close to this concentration as possible. Sanitary M91M Floating solids...

Point source detection in infrared astronomical surveys

NASA Technical Reports Server (NTRS)

Pelzmann, R. F., Jr.

1977-01-01

Data processing techniques useful for infrared astronomy data analysis systems are reported. This investigation is restricted to consideration of data from space-based telescope systems operating as survey instruments. In this report the theoretical background for specific point-source detection schemes is completed, and the development of specific algorithms and software for the broad range of requirements is begun.

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,...

Small catchments DEM creation using Unmanned Aerial Vehicles

NASA Astrophysics Data System (ADS)

Gafurov, A. M.

2018-01-01

Digital elevation models (DEM) are an important source of information on the terrain, allowing researchers to evaluate various exogenous processes. The higher the accuracy of DEM the better the level of the work possible. An important source of data for the construction of DEMs are point clouds obtained with terrestrial laser scanning (TLS) and unmanned aerial vehicles (UAV). In this paper, we present the results of constructing a DEM on small catchments using UAVs. Estimation of the UAV DEM showed comparable accuracy with the TLS if real time kinematic Global Positioning System (RTK-GPS) ground control points (GCPs) and check points (CPs) were used. In this case, the main source of errors in the construction of DEMs are the errors in the referencing of survey results.

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.

Fine Pointing Of The Solar Optical Telescope In The Space Shuttle Environment

NASA Astrophysics Data System (ADS)

Gowrinathan, Sankaran

1987-02-01

Instruments attached to the payload bay of the Space Shuttle require special attention where fine pointing is involved. Fine pointing, for purposes of this discussion, is defined as sub-arc second pointing. Instruments requiring such fine pointing (Solar Optical Telescope and Shuttle Infrared Telescope, for example) will require two stages of pointing (coarse and fine). Coarse pointing will be performed by a gimbal system such as the Instrument Pointing System (IPS). Fine pointing will be provided by image motion compensation (IMC). Most forms of IMC involve adjustable optical elements in the optical system to compensate for fast transient disturbances. This paper describes work performed on the Solar Optical Telescope (SOT) concept design that illustrates IMC as applied to SOT. The fine pointing requirements on SOT dictate use of IMC at about 20 Hz. bandwidth. It will be shown that the need for this high bandwidth is related to shuttle-induced disturbances. Shuttle-induced disturbances are primarily due to two sources; man push-offs and vernier thruster firings. Both disturbance sources have high-frequency content that drive the IMC bandwidth.

40 CFR 420.29 - Point of compliance monitoring.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Point of compliance monitoring. 420.29 Section 420.29 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Sintering Subcategory § 420.29 Point...

40 CFR 407.64 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS CANNED AND PRESERVED FRUITS AND VEGETABLES PROCESSING POINT SOURCE CATEGORY Canned and Preserved Fruits Subcategory § 407.64 Pretreatment standards for existing sources. Any...

40 CFR 461.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY Cadmium Subcategory § 461.13 New source... pollutants from any battery manufacturing operation other than those battery manufacturing operations listed...

40 CFR 461.53 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY Lithium Subcategory § 461.53 New source... pollutants from any battery manufacturing operation other than those battery manufacturing operations listed...

40 CFR 417.64 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Soap Flakes and Powders Subcategory § 417.64 Pretreatment standards for existing sources. Any existing...

40 CFR 417.64 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Soap Flakes and Powders Subcategory § 417.64 Pretreatment standards for existing sources. Any existing...

40 CFR 417.64 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Soap Flakes and Powders Subcategory § 417.64 Pretreatment standards for existing sources. Any existing...

40 CFR 417.64 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Soap Flakes and Powders Subcategory § 417.64 Pretreatment standards for existing sources. Any existing...

40 CFR 417.64 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Soap Flakes and Powders Subcategory § 417.64 Pretreatment standards for existing sources. Any existing...

40 CFR 461.53 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUIDELINES AND STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY Lithium Subcategory § 461.53 New source... pollutants from any battery manufacturing operation other than those battery manufacturing operations listed...

40 CFR 461.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUIDELINES AND STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY Cadmium Subcategory § 461.13 New source... pollutants from any battery manufacturing operation other than those battery manufacturing operations listed...

THE IMPACT OF POINT-SOURCE SUBTRACTION RESIDUALS ON 21 cm EPOCH OF REIONIZATION ESTIMATION

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

Trott, Cathryn M.; Wayth, Randall B.; Tingay, Steven J., E-mail: cathryn.trott@curtin.edu.au

Precise subtraction of foreground sources is crucial for detecting and estimating 21 cm H I signals from the Epoch of Reionization (EoR). We quantify how imperfect point-source subtraction due to limitations of the measurement data set yields structured residual signal in the data set. We use the Cramer-Rao lower bound, as a metric for quantifying the precision with which a parameter may be measured, to estimate the residual signal in a visibility data set due to imperfect point-source subtraction. We then propagate these residuals into two metrics of interest for 21 cm EoR experiments-the angular power spectrum and two-dimensional powermore » spectrum-using a combination of full analytic covariant derivation, analytic variant derivation, and covariant Monte Carlo simulations. This methodology differs from previous work in two ways: (1) it uses information theory to set the point-source position error, rather than assuming a global rms error, and (2) it describes a method for propagating the errors analytically, thereby obtaining the full correlation structure of the power spectra. The methods are applied to two upcoming low-frequency instruments that are proposing to perform statistical EoR experiments: the Murchison Widefield Array and the Precision Array for Probing the Epoch of Reionization. In addition to the actual antenna configurations, we apply the methods to minimally redundant and maximally redundant configurations. We find that for peeling sources above 1 Jy, the amplitude of the residual signal, and its variance, will be smaller than the contribution from thermal noise for the observing parameters proposed for upcoming EoR experiments, and that optimal subtraction of bright point sources will not be a limiting factor for EoR parameter estimation. We then use the formalism to provide an ab initio analytic derivation motivating the 'wedge' feature in the two-dimensional power spectrum, complementing previous discussion in the literature.« less

40 CFR 467.45 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... sources. 467.45 Section 467.45 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ALUMINUM FORMING POINT SOURCE CATEGORY Forging Subcategory § 467.45 Pretreatment standards for existing sources. Except as provided in 40 CFR 403.7 and 403.13, any existing source...

40 CFR 424.16 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS FERROALLOY MANUFACTURING POINT SOURCE CATEGORY Open Electric Furnaces With Wet Air Pollution Control Devices Subcategory § 424.16 Pretreatment standards for new sources. Any new source... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for new sources...

40 CFR 420.44 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true New source performance standards (NSPS... GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Steelmaking Subcategory § 420.44 New source performance standards (NSPS). The discharge of wastewater pollutants from any new source...

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.

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.

40 CFR 427.85 - Standards of performance for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Coating or Finishing of Asbestos Textiles Subcategory § 427.85 Standards of performance for new sources. The following...

40 CFR 427.85 - Standards of performance for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Coating or Finishing of Asbestos Textiles Subcategory § 427.85 Standards of performance for new sources. The following...

40 CFR 427.85 - Standards of performance for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Coating or Finishing of Asbestos Textiles Subcategory § 427.85 Standards of performance for new sources. The following...

40 CFR 415.165 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Sodium Chloride Production... chloride. (b) Any new source subject to this subpart and using the solution brine-mining process must...

40 CFR 432.76 - Pretreatment standards for new sources (PSNS). [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS MEAT AND POULTRY PRODUCTS POINT SOURCE CATEGORY Sausage and Luncheon Meats Processors § 432.76 Pretreatment standards for new sources (PSNS). [Reserved] ...

40 CFR 432.74 - Pretreatment standards for existing sources (PSES). [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS MEAT AND POULTRY PRODUCTS POINT SOURCE CATEGORY Sausage and Luncheon Meats Processors § 432.74 Pretreatment standards for existing sources (PSES). [Reserved] ...

40 CFR 432.76 - Pretreatment standards for new sources (PSNS). [Reserved

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS MEAT AND POULTRY PRODUCTS POINT SOURCE CATEGORY Sausage and Luncheon Meats Processors § 432.76 Pretreatment standards for new sources (PSNS). [Reserved] ...

40 CFR 432.74 - Pretreatment standards for existing sources (PSES). [Reserved

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS MEAT AND POULTRY PRODUCTS POINT SOURCE CATEGORY Sausage and Luncheon Meats Processors § 432.74 Pretreatment standards for existing sources (PSES). [Reserved] ...

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

Quantitative identification of riverine nitrogen from point, direct runoff and base flow sources.

PubMed

Huang, Hong; Zhang, Baifa; Lu, Jun

2014-01-01

We present a methodological example for quantifying the contributions of riverine total nitrogen (TN) from point, direct runoff and base flow sources by combining a recursive digital filter technique and statistical methods. First, we separated daily riverine flow into direct runoff and base flow using a recursive digital filter technique; then, a statistical model was established using daily simultaneous data for TN load, direct runoff rate, base flow rate, and temperature; and finally, the TN loading from direct runoff and base flow sources could be inversely estimated. As a case study, this approach was adopted to identify the TN source contributions in Changle River, eastern China. Results showed that, during 2005-2009, the total annual TN input to the river was 1,700.4±250.2 ton, and the contributions of point, direct runoff and base flow sources were 17.8±2.8%, 45.0±3.6%, and 37.2±3.9%, respectively. The innovation of the approach is that the nitrogen from direct runoff and base flow sources could be separately quantified. The approach is simple but detailed enough to take the major factors into account, providing an effective and reliable method for riverine nitrogen loading estimation and source apportionment.

DEEP ATTRACTOR NETWORK FOR SINGLE-MICROPHONE SPEAKER SEPARATION.

PubMed

Chen, Zhuo; Luo, Yi; Mesgarani, Nima

2017-03-01

Despite the overwhelming success of deep learning in various speech processing tasks, the problem of separating simultaneous speakers in a mixture remains challenging. Two major difficulties in such systems are the arbitrary source permutation and unknown number of sources in the mixture. We propose a novel deep learning framework for single channel speech separation by creating attractor points in high dimensional embedding space of the acoustic signals which pull together the time-frequency bins corresponding to each source. Attractor points in this study are created by finding the centroids of the sources in the embedding space, which are subsequently used to determine the similarity of each bin in the mixture to each source. The network is then trained to minimize the reconstruction error of each source by optimizing the embeddings. The proposed model is different from prior works in that it implements an end-to-end training, and it does not depend on the number of sources in the mixture. Two strategies are explored in the test time, K-means and fixed attractor points, where the latter requires no post-processing and can be implemented in real-time. We evaluated our system on Wall Street Journal dataset and show 5.49% improvement over the previous state-of-the-art methods.

Estimation of diffuse and point source microbial pollution in the ribble catchment discharging to bathing waters in the north west of England.

PubMed

Wither, A; Greaves, J; Dunhill, I; Wyer, M; Stapleton, C; Kay, D; Humphrey, N; Watkins, J; Francis, C; McDonald, A; Crowther, J

2005-01-01

Achieving compliance with the mandatory standards of the 1976 Bathing Water Directive (76/160/EEC) is required at all U.K. identified bathing waters. In recent years, the Fylde coast has been an area of significant investments in 'point source' control, which have not proven, in isolation, to satisfactorily achieve compliance with the mandatory, let alone the guide, levels of water quality in the Directive. The potential impact of riverine sources of pollution was first confirmed after a study in 1997. The completion of sewerage system enhancements offered the potential for the study of faecal indicator delivery from upstream sources comprising both point sources and diffuse agricultural sources. A research project to define these elements commenced in 2001. Initially, a desk study reported here, estimated the principal infrastructure contributions within the Ribble catchment. A second phase of this investigation has involved acquisition of empirical water quality and hydrological data from the catchment during the 2002 bathing season. These data have been used further to calibrate the 'budgets' and 'delivery' modelling and these data are still being analysed. This paper reports the initial desk study approach to faecal indicator budget estimation using available data from the sewerage infrastructure and catchment sources of faecal indicators.

Applicability of the single equivalent point dipole model to represent a spatially distributed bio-electrical source

NASA Technical Reports Server (NTRS)

Armoundas, A. A.; Feldman, A. B.; Sherman, D. A.; Cohen, R. J.

2001-01-01

Although the single equivalent point dipole model has been used to represent well-localised bio-electrical sources, in realistic situations the source is distributed. Consequently, position estimates of point dipoles determined by inverse algorithms suffer from systematic error due to the non-exact applicability of the inverse model. In realistic situations, this systematic error cannot be avoided, a limitation that is independent of the complexity of the torso model used. This study quantitatively investigates the intrinsic limitations in the assignment of a location to the equivalent dipole due to distributed electrical source. To simulate arrhythmic activity in the heart, a model of a wave of depolarisation spreading from a focal source over the surface of a spherical shell is used. The activity is represented by a sequence of concentric belt sources (obtained by slicing the shell with a sequence of parallel plane pairs), with constant dipole moment per unit length (circumferentially) directed parallel to the propagation direction. The distributed source is represented by N dipoles at equal arc lengths along the belt. The sum of the dipole potentials is calculated at predefined electrode locations. The inverse problem involves finding a single equivalent point dipole that best reproduces the electrode potentials due to the distributed source. The inverse problem is implemented by minimising the chi2 per degree of freedom. It is found that the trajectory traced by the equivalent dipole is sensitive to the location of the spherical shell relative to the fixed electrodes. It is shown that this trajectory does not coincide with the sequence of geometrical centres of the consecutive belt sources. For distributed sources within a bounded spherical medium, displaced from the sphere's centre by 40% of the sphere's radius, it is found that the error in the equivalent dipole location varies from 3 to 20% for sources with size between 5 and 50% of the sphere's radius. Finally, a method is devised to obtain the size of the distributed source during the cardiac cycle.

NuSTAR Hard X-Ray Survey of the Galactic Center Region. II. X-Ray Point Sources

NASA Technical Reports Server (NTRS)

Hong, Jaesub; Mori, Kaya; Hailey, Charles J.; Nynka, Melania; Zhang, Shou; Gotthelf, Eric; Fornasini, Francesca M.; Krivonos, Roman; Bauer, Franz; Perez, Kerstin;

VizieR Online Data Catalog: M31 center emission-line point-like sources (Martin+, 2018)

NASA Astrophysics Data System (ADS)

Martin, T. B.; Drissen, L.; Melchior, A.-L.

2017-11-01

We present a catalogue of the point-like sources in the central 11'x11' part of M31 obtained with SITELLE. For each source we report the radial velocity as long as the spectrophotmetric flux of H-alpha, [NII]6584 and the sum of the [SII]6717,6731 doublet. The ID of the sources cross-matched with the catalogues from Merrett et al. (2006MNRAS.369..120M, J/MNRAS/369/120) and Halliday et al. (2006MNRAS.369...97H, J/MNRAS/369/97) are also indicated. We also report the detection of the sources in the images of the Local Group Galaxies Survey (Massey et al., 2006, 2006AJ....131.2478M). (1 data file).

Sources of endocrine-disrupting compounds in North Carolina waterways: a geographic information systems approach

USGS Publications Warehouse

Sackett, Dana K.; Pow, Crystal Lee; Rubino, Matthew J.; Aday, D.D.; Cope, W. Gregory; Kullman, Seth W.; Rice, J.A.; Kwak, Thomas J.; Law, L.M.

2015-01-01

The presence of endocrine-disrupting compounds (EDCs), particularly estrogenic compounds, in the environment has drawn public attention across the globe, yet a clear understanding of the extent and distribution of estrogenic EDCs in surface waters and their relationship to potential sources is lacking. The objective of the present study was to identify and examine the potential input of estrogenic EDC sources in North Carolina water bodies using a geographic information system (GIS) mapping and analysis approach. Existing data from state and federal agencies were used to create point and nonpoint source maps depicting the cumulative contribution of potential sources of estrogenic EDCs to North Carolina surface waters. Water was collected from 33 sites (12 associated with potential point sources, 12 associated with potential nonpoint sources, and 9 reference), to validate the predictive results of the GIS analysis. Estrogenicity (measured as 17β-estradiol equivalence) ranged from 0.06 ng/L to 56.9 ng/L. However, the majority of sites (88%) had water 17β-estradiol concentrations below 1 ng/L. Sites associated with point and nonpoint sources had significantly higher 17β-estradiol levels than reference sites. The results suggested that water 17β-estradiol was reflective of GIS predictions, confirming the relevance of landscape-level influences on water quality and validating the GIS approach to characterize such relationships.

Sources of endocrine-disrupting compounds in North Carolina waterways: a geographic information systems approach.

PubMed

Sackett, Dana K; Pow, Crystal Lee; Rubino, Matthew J; Aday, D Derek; Cope, W Gregory; Kullman, Seth; Rice, James A; Kwak, Thomas J; Law, Mac

2015-02-01

The presence of endocrine-disrupting compounds (EDCs), particularly estrogenic compounds, in the environment has drawn public attention across the globe, yet a clear understanding of the extent and distribution of estrogenic EDCs in surface waters and their relationship to potential sources is lacking. The objective of the present study was to identify and examine the potential input of estrogenic EDC sources in North Carolina water bodies using a geographic information system (GIS) mapping and analysis approach. Existing data from state and federal agencies were used to create point and nonpoint source maps depicting the cumulative contribution of potential sources of estrogenic EDCs to North Carolina surface waters. Water was collected from 33 sites (12 associated with potential point sources, 12 associated with potential nonpoint sources, and 9 reference), to validate the predictive results of the GIS analysis. Estrogenicity (measured as 17β-estradiol equivalence) ranged from 0.06 ng/L to 56.9 ng/L. However, the majority of sites (88%) had water 17β-estradiol concentrations below 1 ng/L. Sites associated with point and nonpoint sources had significantly higher 17β-estradiol levels than reference sites. The results suggested that water 17β-estradiol was reflective of GIS predictions, confirming the relevance of landscape-level influences on water quality and validating the GIS approach to characterize such relationships. © 2014 SETAC.

40 CFR 419.37 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Pretreatment standards for new sources...) EFFLUENT GUIDELINES AND STANDARDS PETROLEUM REFINING POINT SOURCE CATEGORY Petrochemical Subcategory § 419.37 Pretreatment standards for new sources (PSNS). Except as provided in 40 CFR 403.7, any new source...

40 CFR 418.66 - Pretreatment standard for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... GUIDELINES AND STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production... the Act for a new source within the ammonium sulfate subcategory which is a user of a publicly owned...

40 CFR 418.66 - Pretreatment standard for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... GUIDELINES AND STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production... the Act for a new source within the ammonium sulfate subcategory which is a user of a publicly owned...

40 CFR 418.66 - Pretreatment standard for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... GUIDELINES AND STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production... the Act for a new source within the ammonium sulfate subcategory which is a user of a publicly owned...

40 CFR 418.66 - Pretreatment standard for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production... the Act for a new source within the ammonium sulfate subcategory which is a user of a publicly owned...

40 CFR 418.66 - Pretreatment standard for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUIDELINES AND STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production... the Act for a new source within the ammonium sulfate subcategory which is a user of a publicly owned...

40 CFR 447.15 - Standards of performance for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) INK FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Ink Subcategory § 447.15 Standards of performance for new sources. The following standards of...

40 CFR 447.15 - Standards of performance for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) INK FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Ink Subcategory § 447.15 Standards of performance for new sources. The following standards of...

40 CFR 447.15 - Standards of performance for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) INK FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Ink Subcategory § 447.15 Standards of performance for new sources. The following standards of...

40 CFR 427.85 - Standards of performance for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS ASBESTOS MANUFACTURING POINT SOURCE CATEGORY Coating or Finishing of Asbestos Textiles Subcategory § 427.85 Standards of performance for new sources. The following standards of...

40 CFR 443.46 - Pretreatment standard for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND PRETREATMENT STANDARDS FOR NEW SOURCES FOR THE PAVING AND ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Linoleum and Printed Asphalt Felt Subcategory § 443.46 Pretreatment standard for...