A multiple-location model for natural gas forward curves

International Nuclear Information System (INIS)

Buffington, J.C.

1999-06-01

This thesis presents an approach for financial modelling of natural gas in which connections between locations are incorporated and the complexities of forward curves in natural gas are considered. Apart from electricity, natural gas is the most volatile commodity traded. Its price is often dependent on the weather and price shocks can be felt across several geographic locations. This modelling approach incorporates multiple risk factors that correspond to various locations. One of the objectives was to determine if the model could be used for closed-form option prices. It was suggested that an adequate model for natural gas must consider 3 statistical properties: volatility term structure, backwardation and contango, and stochastic basis. Data from gas forward prices at Chicago, NYMEX and AECO were empirically tested to better understand these 3 statistical properties at each location and to verify if the proposed model truly incorporates these properties. In addition, this study examined the time series property of the difference of two locations (the basis) and determines that these empirical properties are consistent with the model properties. Closed-form option solutions were also developed for call options of forward contracts and call options on forward basis. The options were calibrated and compared to other models. The proposed model is capable of pricing options, but the prices derived did not pass the test of economic reasonableness. However, the model was able to capture the effect of transportation as well as aspects of seasonality which is a benefit over other existing models. It was determined that modifications will be needed regarding the estimation of the convenience yields. 57 refs., 2 tabs., 7 figs., 1 append

A location procedure for sound sources in reactor-technical enclosures

International Nuclear Information System (INIS)

Hamann, D.

1982-07-01

A passive method requiring one detector only has been developed for the location of sound emitting faults in nuclear power plant components. It is adapted for use in a frequency range the wavelength of which is of the same order of magnitude as characteristic dimensions of the considered enclosure. The location is performed in the following way: (1) For a fixed detector position the Auto Power Spectral Density (APSD) of the source to be located is measured. (2) For this detector position the APSD is calculated for the potential source locations. For this, the free-field APSD as well as the acoustic normal modes of the enclosure are necessary. (3) The measured APSD is compared with the theoretically obtained APSD's. (4) That APSD is determined which is most similar to the measured APSD, and consequently an information about the unknown source position is got. (author)

48 CFR 19.202-2 - Locating small business sources.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Locating small business... SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Policies 19.202-2 Locating small business sources. The contracting officer must, to the extent practicable, encourage maximum participation by small business...

Method to Locate Contaminant Source and Estimate Emission Strength

Directory of Open Access Journals (Sweden)

Qu Hongquan

2013-01-01

Full Text Available People greatly concern the issue of air quality in some confined spaces, such as spacecraft, aircraft, and submarine. With the increase of residence time in such confined space, contaminant pollution has become a main factor which endangers life. It is urgent to identify a contaminant source rapidly so that a prompt remedial action can be taken. A procedure of source identification should be able to locate the position and to estimate the emission strength of the contaminant source. In this paper, an identification method was developed to realize these two aims. This method was developed based on a discrete concentration stochastic model. With this model, a sensitivity analysis algorithm was induced to locate the source position, and a Kalman filter was used to further estimate the contaminant emission strength. This method could track and predict the source strength dynamically. Meanwhile, it can predict the distribution of contaminant concentration. Simulation results have shown the virtues of the method.

48 CFR 319.202-2 - Locating small business sources.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Locating small business... SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Policies 319.202-2 Locating small business sources. (a) OPDIVs shall foster, to the extent practicable, maximum participation by small businesses in HHS acquisitions...

48 CFR 2919.202-2 - Locating small business sources.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Locating small business... SOCIOECONOMIC PROGRAMS SMALL BUSINESS AND SMALL DISADVANTAGED BUSINESS CONCERNS Policies 2919.202-2 Locating small business sources. Any procurement conducted on an unrestricted basis will include solicitations to...

Influence of external source location in the reactivity calculation

International Nuclear Information System (INIS)

Silva, Adilson Costa da; Silva, Fernando Carvalho da; Martinez, Aquilino Senra

2011-01-01

We used the neutron diffusion equation with external neutron sources, in cartesian geometry and the two groups of energy, to verify the influence of external neutron source locations in the reactivity calculation. For this, a coarse mesh finite difference method was developed for the adjoint flux calculation and simplifies reactivity calculation in PWR type reactor, which uses the output of the nodal expansion method. The results were obtained for different locations on the two-dimensional plane, as well as for different types of fuel elements in the reactor core. (author)

Influence of external source location in the reactivity calculation

Energy Technology Data Exchange (ETDEWEB)

Silva, Adilson Costa da; Silva, Fernando Carvalho da; Martinez, Aquilino Senra, E-mail: asilva@con.ufrj.b, E-mail: fernando@con.ufrj.b, E-mail: Aquilino@lmp.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

2011-07-01

We used the neutron diffusion equation with external neutron sources, in cartesian geometry and the two groups of energy, to verify the influence of external neutron source locations in the reactivity calculation. For this, a coarse mesh finite difference method was developed for the adjoint flux calculation and simplifies reactivity calculation in PWR type reactor, which uses the output of the nodal expansion method. The results were obtained for different locations on the two-dimensional plane, as well as for different types of fuel elements in the reactor core. (author)

Locating the source of diffusion in complex networks by time-reversal backward spreading

Science.gov (United States)

Shen, Zhesi; Cao, Shinan; Wang, Wen-Xu; Di, Zengru; Stanley, H. Eugene

2016-03-01

Locating the source that triggers a dynamical process is a fundamental but challenging problem in complex networks, ranging from epidemic spreading in society and on the Internet to cancer metastasis in the human body. An accurate localization of the source is inherently limited by our ability to simultaneously access the information of all nodes in a large-scale complex network. This thus raises two critical questions: how do we locate the source from incomplete information and can we achieve full localization of sources at any possible location from a given set of observable nodes. Here we develop a time-reversal backward spreading algorithm to locate the source of a diffusion-like process efficiently and propose a general locatability condition. We test the algorithm by employing epidemic spreading and consensus dynamics as typical dynamical processes and apply it to the H1N1 pandemic in China. We find that the sources can be precisely located in arbitrary networks insofar as the locatability condition is assured. Our tools greatly improve our ability to locate the source of diffusion in complex networks based on limited accessibility of nodal information. Moreover, they have implications for controlling a variety of dynamical processes taking place on complex networks, such as inhibiting epidemics, slowing the spread of rumors, pollution control, and environmental protection.

A New Wave Equation Based Source Location Method with Full-waveform Inversion

KAUST Repository

Wu, Zedong

2017-05-26

Locating the source of a passively recorded seismic event is still a challenging problem, especially when the velocity is unknown. Many imaging approaches to focus the image do not address the velocity issue and result in images plagued with illumination artifacts. We develop a waveform inversion approach with an additional penalty term in the objective function to reward the focusing of the source image. This penalty term is relaxed early to allow for data fitting, and avoid cycle skipping, using an extended source. At the later stages the focusing of the image dominates the inversion allowing for high resolution source and velocity inversion. We also compute the source location explicitly and numerical tests show that we obtain good estimates of the source locations with this approach.

Doses arising from natural radiation sources in Hong Kong

International Nuclear Information System (INIS)

Tso Man-yin, W.

1993-01-01

The first reactor of the Daya Bay Nuclear Power Plant, located 30 km from Hong Kong, should become operational at the end of 1993. People in Hong Kong are more concerned with their exposures to radiation, both man-made and natural. The local environmental background radiation baseline values should be established well before 1993 so that the radiological impact of the power plant on the environment can be assessed. However, there has not been much information on these aspects. In view of the situation, the Radioisotope Unit of the University of Hong Kong has launched a series of studies with the general goal of gaining a better understanding of Hong Kong's natural background radiation and a more accurate estimate of the natural radiation exposure of the local people. The scope of the measurement programmes is described and the doses from the various sources are derived. (1 tab.)

Gamma ray burst source locations with the Ulysses/Compton/PVO Network

International Nuclear Information System (INIS)

Cline, T.L.; Hurley, K.C.; Boer, M.; Sommer, M.; Niel, M.; Fishman, G.J.; Kouveliotou, C.; Meegan, C.A.; Paciesas, W.S.; Wilson, R.B.; Laros, J.G.; Klebesadel, R.W.

1991-01-01

The new interplanetary gamma-ray burst network will determine source fields with unprecedented accuracy. The baseline of the Ulysses mission and the locations of Pioneer-Venus Orbiter and of Mars Observer will ensure precision to a few tens of arc seconds. Combined with the event phenomenologies of the Burst and Transient Source Experiment on Compton Observatory, the source locations to be achieved with this network may provide a basic new understanding of the puzzle of gamma ray bursts

Towards an accurate real-time locator of infrasonic sources

Science.gov (United States)

Pinsky, V.; Blom, P.; Polozov, A.; Marcillo, O.; Arrowsmith, S.; Hofstetter, A.

2017-11-01

Infrasonic signals propagate from an atmospheric source via media with stochastic and fast space-varying conditions. Hence, their travel time, the amplitude at sensor recordings and even manifestation in the so-called "shadow zones" are random. Therefore, the traditional least-squares technique for locating infrasonic sources is often not effective, and the problem for the best solution must be formulated in probabilistic terms. Recently, a series of papers has been published about Bayesian Infrasonic Source Localization (BISL) method based on the computation of the posterior probability density function (PPDF) of the source location, as a convolution of a priori probability distribution function (APDF) of the propagation model parameters with likelihood function (LF) of observations. The present study is devoted to the further development of BISL for higher accuracy and stability of the source location results and decreasing of computational load. We critically analyse previous algorithms and propose several new ones. First of all, we describe the general PPDF formulation and demonstrate that this relatively slow algorithm might be among the most accurate algorithms, provided the adequate APDF and LF are used. Then, we suggest using summation instead of integration in a general PPDF calculation for increased robustness, but this leads us to the 3D space-time optimization problem. Two different forms of APDF approximation are considered and applied for the PPDF calculation in our study. One of them is previously suggested, but not yet properly used is the so-called "celerity-range histograms" (CRHs). Another is the outcome from previous findings of linear mean travel time for the four first infrasonic phases in the overlapping consecutive distance ranges. This stochastic model is extended here to the regional distance of 1000 km, and the APDF introduced is the probabilistic form of the junction between this travel time model and range-dependent probability

Marine Vibrionaceae as a source of bioactive natural products

DEFF Research Database (Denmark)

Månsson, Maria; Wietz, Matthias; Gram, Lone

an ecological function. Using chemical profiling, vibrio strains were compared on a global scale, revealing that the production of certain compounds is a conserved feature independent of sample locations. Chemical screening techniques such as explorative solid-phase extraction led to the isolation of two novel...... that some strains were capable of producing antibacterial compounds when grown on natural substrates such as chitin or seaweed. One Vibrio coralliilyticus strain was capable of producing the antibacterial compound when using chitin as the sole carbon source and in a live chitin model system, suggesting...... of which possess biological activities attractive for alternative strategies in antibacterial therapy....

Exposure to natural sources of radiation in Spain

International Nuclear Information System (INIS)

Quindos, L.S.; Fernandez, P.L.; Soto, J.

1992-01-01

Studies carried by us during last three years have produced a map of natural radiation for Spain. The map contains, by administrative region, the respective contributions of terrestrial gamma rays, both outdoors and indoors, cosmic rays and indoor radon. Terrestrial gamma rays have been measured outdoors 'in situ' in more than 1,000 locations. Data for indoor gamma rays were derived from the radioactivity content of more typical spanish building materials as also by 'in situ'measurements in approximately 100 houses. The cosmic ray component is calculated from latitude and altitude. Values for indoor radon exposure have been derived from a national survey and covering more than 2,000 individual measurements employing active and passive detectors. When account is taken of exposures elsewhere, the mean annual effective dose equivalent from these sources is evaluated. Doses from thoron decay products and internal exposure due to natural activity retained in the body from diet are not dealt with in this evaluation. (author)

Natural Colorants: Food Colorants from Natural Sources.

Science.gov (United States)

Sigurdson, Gregory T; Tang, Peipei; Giusti, M Mónica

2017-02-28

The color of food is often associated with the flavor, safety, and nutritional value of the product. Synthetic food colorants have been used because of their high stability and low cost. However, consumer perception and demand have driven the replacement of synthetic colorants with naturally derived alternatives. Natural pigment applications can be limited by lower stability, weaker tinctorial strength, interactions with food ingredients, and inability to match desired hues. Therefore, no single naturally derived colorant can serve as a universal alternative for a specified synthetic colorant in all applications. This review summarizes major environmental and biological sources for natural colorants as well as nature-identical counterparts. Chemical characteristics of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls, are described. The possible applications and hues (warm, cool, and achromatic) of currently used natural pigments, such as anthocyanins as red and blue colorants, and possible future alternatives, such as purple violacein and red pyranoanthocyanins, are also discussed.

Alternative sources of natural rubber

NARCIS (Netherlands)

Mooibroek, H.; Cornish, K.

2000-01-01

Rubber (cis-1,4-polyisoprene) is one of the most important polymers naturally produced by plants because it is a strategic raw material used in more than 40,000 products, including more than 400 medical devices. The sole commercial source, at present, is natural rubber harvested from the Brazilian

Wavefield dependency on virtual shifts in the source location

KAUST Repository

Alkhalifah, Tariq

2011-02-14

The wavefield dependence on a virtual shift in the source location can provide information helpful in velocity estimation and interpolation. However, the second-order partial differential equation (PDE) that relates changes in the wavefield form (or shape) to lateral perturbations in the source location depends explicitly on lateral derivatives of the velocity field. For velocity models that include lateral velocity discontinuities this is problematic as such derivatives in their classical definition do not exist. As a result, I derive perturbation partial differential wave equations that are independent of direct velocity derivatives and thus, provide possibilities for wavefield shape extrapolation in complex media. These PDEs have the same structure as the wave equation with a source function that depends on the background (original source) wavefield. The solutions of the perturbation equations provide the coefficients of a Taylor\\'s series type expansion for the wavefield. The new formulas introduce changes to the background wavefield only in the presence of lateral velocity variation or in general terms velocity variations in the perturbation direction. The accuracy of the representation, as demonstrated on the Marmousi model, is generally good. © 2011 European Association of Geoscientists & Engineers.

A Practical Method of Acoustic Emission Source Location in Anisotropic Composite Laminates

Energy Technology Data Exchange (ETDEWEB)

Kim, Jeong Kon; Kang, Yong Kyu; Kwon, Oh Yang [Inha University, Incheon (Korea, Republic of)

2003-06-15

Since the velocity is dependent on the fiber orientation in anisotropic composites, the application of traditional acoustic emission (AE) source location techniques based on the constant velocity to composite structures has been practically impossible. The anisotropy makes the source location procedure complicated and deteriorates the accuracy of the location. In this study, we have divided the region of interest(ROI) into a set of finite elements, taken each element as a virtual source, and calculated the arrival time differences between sensors by using the velocities at every degree from 0 to 90. The calculated and the experimentally measured values of the arrival time difference aye then compared to minimize the location error. The results from two different materials, namely AA6061-T6 and CFRP(uni-directional; UD, [0]{sub 32}4 ) laminate confirmed the practical usefulness of the proposed method

An eikonal-based formulation for traveltime perturbation with respect to the source location

KAUST Repository

Alkhalifah, Tariq

2010-11-01

Traveltime calculations amount to solving the nonlinear eikonal equation for a given source location. The relationship between the eikonal solution and its perturbations is analyzed with respect to the source location and a partial differential equation is developed that relates the traveltime field for one source location to that for a nearby source. This linear first-order equation in one form depends on lateral changes in velocity and in another form is independent of the velocity field and relies on second-order derivatives of the original traveltime field. For stable finite-difference calculations, this requires the velocity field to be smooth in a sense similar to ray-tracing requirements. Our formulation for traveltime perturbation has several potential applications, such that as traveltime calculation by source-location perturbation, velocity-independent interpolation including datuming, and velocity estimation. Additionally, higher-order expansions provide parameters necessary for Gaussian-beam computations. © 2010 Society of Exploration Geophysicists.

An eikonal-based formulation for traveltime perturbation with respect to the source location

KAUST Repository

Alkhalifah, Tariq; Fomel, Sergey

2010-01-01

Traveltime calculations amount to solving the nonlinear eikonal equation for a given source location. The relationship between the eikonal solution and its perturbations is analyzed with respect to the source location and a partial differential equation is developed that relates the traveltime field for one source location to that for a nearby source. This linear first-order equation in one form depends on lateral changes in velocity and in another form is independent of the velocity field and relies on second-order derivatives of the original traveltime field. For stable finite-difference calculations, this requires the velocity field to be smooth in a sense similar to ray-tracing requirements. Our formulation for traveltime perturbation has several potential applications, such that as traveltime calculation by source-location perturbation, velocity-independent interpolation including datuming, and velocity estimation. Additionally, higher-order expansions provide parameters necessary for Gaussian-beam computations. © 2010 Society of Exploration Geophysicists.

An inverse source location algorithm for radiation portal monitor applications

International Nuclear Information System (INIS)

Miller, Karen A.; Charlton, William S.

2010-01-01

Radiation portal monitors are being deployed at border crossings throughout the world to prevent the smuggling of nuclear and radiological materials; however, a tension exists between security and the free-flow of commerce. Delays at ports-of-entry have major economic implications, so it is imperative to minimize portal monitor screening time. We have developed an algorithm to locate a radioactive source using a distributed array of detectors, specifically for use at border crossings. To locate the source, we formulated an optimization problem where the objective function describes the least-squares difference between the actual and predicted detector measurements. The predicted measurements are calculated by solving the 3-D deterministic neutron transport equation given an estimated source position. The source position is updated using the steepest descent method, where the gradient of the objective function with respect to the source position is calculated using adjoint transport calculations. If the objective function is smaller than the convergence criterion, then the source position has been identified. This paper presents the derivation of the underlying equations in the algorithm as well as several computational test cases used to characterize its accuracy.

Natural and technologically enhanced sources of radon-222

International Nuclear Information System (INIS)

Travis, C.C.; Watson, A.P.; McDowell-Boyer, L.M.; Cotter, S.J.; Randolph, M.L.; Fields, D.E.

1979-01-01

An assessment of 222 Rn releases (curies/year) from major natural and technologically enhanced sources in the United States is presented. The resulting inhalation population dose commitments to the bronchial epithelium of the lung (lung-rem) are also estimated. The sources of radon considered are natural soil, evapotranspiration, potable water supplies, building materials, natural gas, uranium mining and milling, coal and phosphate mining, phosphate fertilizer, liquefied petroleum gas, geothermal power facilities, coal-fired power plants, and gas and oil wells. The most important natural source of 222 Rn is decay of 226 Ra in the soil and rocks of the earth's crust. This source results in approximately 40% of the total population dose from all sources of radon. The largest technoligcally enhanced contributor to population dose is airborne 222 Rn in building interiors, which is estimated to contribute 55% to the total population exposure to 222 Rn. Each of the other sources is estimated to contribute less than 3% to the total

Wavefield dependency on virtual shifts in the source location

KAUST Repository

Alkhalifah, Tariq

2011-01-01

shape) to lateral perturbations in the source location depends explicitly on lateral derivatives of the velocity field. For velocity models that include lateral velocity discontinuities this is problematic as such derivatives in their classical

Exposures to natural radiation sources. Annex B

International Nuclear Information System (INIS)

1982-01-01

The assessment of the radiation doses from natural sources in humans is presented. Both external sources of extraterrestrial origin (cosmic rays) and of terrestrial origin, and internal sources, comprising the naturally-occurring radionuclides which are taken into the human body, are discussed. This Annex is to a large extent a summary of Annex B of the 1977 report of the Committee. The doses due to the radon isotopes and to their short-lived decay products are briefly reviewed.

The natural sources of ionizing radiation exposure

International Nuclear Information System (INIS)

Maximilien, R.

1982-01-01

Natural sources of ionizing radiation include external sources (cosmic rays, natural radionuclides present in the crust of the earth and in building materials) and internal sources (naturally occuring radionuclides in the human body, especially the potassium 40 and radon short lived decay products). The principal ways of human exposure to theses different components in ''normal'' areas are reviewed; some examples of the variability of exposure with respect to different regions of the world or the habits of life are given. Actual estimations of the doses delivered to the organs are presented; for the main contributors to population exposure, the conversion into effective dose equivalent has been made for allowing a better evaluation of their respective importance [fr

Analysis of Natural Ventilation in a Passive House Located in Cold Conditions

DEFF Research Database (Denmark)

Oropeza-Perez, Ivan; Østergaard, Poul Alberg; Remmen, Arne

2013-01-01

in Vejle during cooling season, in the months of June, July and August. The dwelling belongs to a Danish project of passive houses denominated Komfort Husene, where its occupants claim there is no thermal comfort in summer time. The results show that the use of natural ventilation helps to reduce......This article shows the potential of using natural ventilation as a passive method of cooling buildings that are located in cold climate countries using Denmark as a case study. The energy saving potential of natural ventilation is found by performing thermal simulations of a household located...

Locating a compact odor source using a four-channel insect electroantennogram sensor

Energy Technology Data Exchange (ETDEWEB)

Myrick, A J; Baker, T C [Chemical Ecology Laboratory, Department of Entomology, Pennsylvania State University, University Park, PA 16802 (United States)

2011-03-15

Here we demonstrate the feasibility of using an array of live insects to detect concentrated packets of odor and infer the location of an odor source ({approx}15 m away) using a backward Lagrangian dispersion model based on the Langevin equation. Bayesian inference allows uncertainty to be quantified, which is useful for robotic planning. The electroantennogram (EAG) is the biopotential developed between the tissue at the tip of an insect antenna and its base, which is due to the massed response of the olfactory receptor neurons to an odor stimulus. The EAG signal can carry tens of bits per second of information with a rise time as short as 12 ms (K A Justice 2005 J. Neurophiol. 93 2233-9). Here, instrumentation including a GPS with a digital compass and an ultrasonic 2D anemometer has been integrated with an EAG odor detection scheme, allowing the location of an odor source to be estimated by collecting data at several downwind locations. Bayesian inference in conjunction with a Lagrangian dispersion model, taking into account detection errors, has been implemented resulting in an estimate of the odor source location within 0.2 m of the actual location.

Locating a compact odor source using a four-channel insect electroantennogram sensor

International Nuclear Information System (INIS)

Myrick, A J; Baker, T C

2011-01-01

Here we demonstrate the feasibility of using an array of live insects to detect concentrated packets of odor and infer the location of an odor source (∼15 m away) using a backward Lagrangian dispersion model based on the Langevin equation. Bayesian inference allows uncertainty to be quantified, which is useful for robotic planning. The electroantennogram (EAG) is the biopotential developed between the tissue at the tip of an insect antenna and its base, which is due to the massed response of the olfactory receptor neurons to an odor stimulus. The EAG signal can carry tens of bits per second of information with a rise time as short as 12 ms (K A Justice 2005 J. Neurophiol. 93 2233-9). Here, instrumentation including a GPS with a digital compass and an ultrasonic 2D anemometer has been integrated with an EAG odor detection scheme, allowing the location of an odor source to be estimated by collecting data at several downwind locations. Bayesian inference in conjunction with a Lagrangian dispersion model, taking into account detection errors, has been implemented resulting in an estimate of the odor source location within 0.2 m of the actual location.

The effect of location of a convective heat source on displacement ventilation: CFD study

Energy Technology Data Exchange (ETDEWEB)

Park, H.J.; Holland, D. [Dunham Associates, Inc., Minneapolis, MN (United States). Advanced Technologies Group

2001-08-01

Two-dimensional computational simulations are performed to examine the effect of vertical location of a convective heat source on thermal displacement ventilation systems. In this study, a heat source is modeled with seven different heights from the floor (0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0 m) in a displacement ventilation environment. The flow and temperature fields in thermal displacement ventilation systems vary depending on the location of the heat source. As the heat source rises, the convective heat gain from the heat source to an occupied zone becomes less significant. This effect changes the temperature field and results in the reduction of the cooling load in the occupied zone. The stratification level is also affected by the heat source location at a given flow rate. (author)

Genetic variation in total number and locations of GnRH neurons identified using in situ hybridization in a wild-source population.

Science.gov (United States)

Kaugars, Katherine E; Rivers, Charlotte I; Saha, Margaret S; Heideman, Paul D

2016-02-01

The evolution of brain function in the regulation of physiology may depend in part upon the numbers and locations of neurons. Wild populations of rodents contain natural genetic variation in the inhibition of reproduction by winter-like short photoperiod, and it has been hypothesized that this functional variation might be due in part to heritable variation in the numbers or location of gonadotropin releasing hormone (GnRH) neurons. A naturally variable wild-source population of white-footed mice was used to develop lines artificially selected for or against mature gonads in short, winter-like photoperiods. We compared a selection line that is reproductively inhibited in short photoperiod (Responsive) to a line that is weakly inhibited by short photoperiod (Nonresponsive) for differences in counts of neurons identified using in situ hybridization for GnRH mRNA. There was no effect of photoperiod, but there were 60% more GnRH neurons in total in the Nonresponsive selection line than the Responsive selection line. The lines differed specifically in numbers of GnRH neurons in more anterior regions, whereas numbers of GnRH neurons in posterior areas were not statistically different between lines. We compare these results to those of an earlier study that used immunohistochemical labeling for GnRH neurons. The results are consistent with the hypothesis that the selection lines and natural source population contain significant genetic variation in the number and location of GnRH neurons. The variation in GnRH neurons may contribute to functional variation in fertility that occurs in short photoperiods in the laboratory and in the wild source population in winter. © 2015 Wiley Periodicals, Inc.

Locating Microseism Sources Using Spurious Arrivals in Intercontinental Noise Correlations

Science.gov (United States)

Retailleau, Lise; Boué, Pierre; Stehly, Laurent; Campillo, Michel

2017-10-01

The accuracy of Green's functions retrieved from seismic noise correlations in the microseism frequency band is limited by the uneven distribution of microseism sources at the surface of the Earth. As a result, correlation functions are often biased as compared to the expected Green's functions, and they can include spurious arrivals. These spurious arrivals are seismic arrivals that are visible on the correlation and do not belong to the theoretical impulse response. In this article, we propose to use Rayleigh wave spurious arrivals detected on correlation functions computed between European and United States seismic stations to locate microseism sources in the Atlantic Ocean. We perform a slant stack on a time distance gather of correlations obtained from an array of stations that comprises a regional deployment and a distant station. The arrival times and the apparent slowness of the spurious arrivals lead to the location of their source, which is obtained through a grid search procedure. We discuss improvements in the location through this methodology as compared to classical back projection of microseism energy. This method is interesting because it only requires an array and a distant station on each side of an ocean, conditions that can be met relatively easily.

Cartilage immunoprivilege depends on donor source and lesion location.

Science.gov (United States)

Arzi, B; DuRaine, G D; Lee, C A; Huey, D J; Borjesson, D L; Murphy, B G; Hu, J C Y; Baumgarth, N; Athanasiou, K A

2015-09-01

The ability to repair damaged cartilage is a major goal of musculoskeletal tissue engineering. Allogeneic (same species, different individual) or xenogeneic (different species) sources can provide an attractive source of chondrocytes for cartilage tissue engineering, since autologous (same individual) cells are scarce. Immune rejection of non-autologous hyaline articular cartilage has seldom been considered due to the popular notion of "cartilage immunoprivilege". The objective of this study was to determine the suitability of allogeneic and xenogeneic engineered neocartilage tissue for cartilage repair. To address this, scaffold-free tissue engineered articular cartilage of syngeneic (same genetic background), allogeneic, and xenogeneic origin were implanted into two different locations of the rabbit knee (n=3 per group/location). Xenogeneic engineered cartilage and control xenogeneic chondral explants provoked profound innate inflammatory and adaptive cellular responses, regardless of transplant location. Cytological quantification of immune cells showed that, while allogeneic neocartilage elicited an immune response in the patella, negligible responses were observed when implanted into the trochlea; instead the responses were comparable to microfracture-treated empty defect controls. Allogeneic neocartilage survived within the trochlea implant site and demonstrated graft integration into the underlying bone. In conclusion, the knee joint cartilage does not represent an immune privileged site, strongly rejecting xenogeneic but not allogeneic chondrocytes in a location-dependent fashion. This difference in location-dependent survival of allogeneic tissue may be associated with proximity to the synovium. Through a series of in vivo studies this research demonstrates that articular cartilage is not fully immunoprivileged. In addition, we now show that anatomical location of the defect, even within the same joint compartment, strongly influences the degree of the

Sound source location in cavitating tip vortices

International Nuclear Information System (INIS)

Higuchi, H.; Taghavi, R.; Arndt, R.E.A.

1985-01-01

Utilizing an array of three hydrophones, individual cavitation bursts in a tip vortex could be located. Theoretically, four hydrophones are necessary. Hence the data from three hydrophones are supplemented with photographic observation of the cavitating tip vortex. The cavitation sound sources are found to be localized to within one base chord length from the hydrofoil tip. This appears to correspond to the region of initial tip vortex roll-up. A more extensive study with a four sensor array is now in progress

Attributing Methane and Carbon Dioxide Emissions from Anthropogenic and Natural Sources Using AVIRIS-NG

Science.gov (United States)

Thorpe, A. K.; Frankenberg, C.; Thompson, D. R.; Duren, R. M.; Aubrey, A. D.; Bue, B. D.; Green, R. O.; Gerilowski, K.; Krings, T.; Borchardt, J.; Kort, E. A.; Sweeney, C.; Conley, S. A.; Roberts, D. A.; Dennison, P. E.; Ayasse, A.

2016-12-01

Imaging spectrometers like the next generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG) can map large regions with the high spatial resolution necessary to resolve methane (CH4) and carbon dioxide (CO2) emissions. This capability is aided by real time detection and geolocation of gas plumes, permitting unambiguous identification of individual emission source locations and communication to ground teams for rapid follow up. We present results from AVIRIS-NG flight campaigns in the Four Corners region (Colorado and New Mexico) and the San Joaquin Valley (California). Over three hundred plumes were observed, reflecting emissions from anthropogenic and natural sources. Examples of plumes will be shown for a number of sources, including CH4 from well completions, gas processing plants, tanks, pipeline leaks, natural seeps, and CO2 from power plants. Despite these promising results, an imaging spectrometer built exclusively for quantitative mapping of gas plumes would have improved sensitivity compared to AVIRIS-NG. For example, an instrument providing a 1 nm spectral sampling (2,000-2,400 micron) would permit mapping CH4, CO2, H2O, CO, and N2O from more diffuse sources using both airborne and orbital platforms. The ability to identify emission sources offers the potential to constrain regional greenhouse gas budgets and improve partitioning between anthropogenic and natural emission sources. Because the CH4 lifetime is only about 9 years and CH4 has a Global Warming Potential 86 times that of CO2 for a 20 year time interval, mitigating these emissions is a particularly cost-effective approach to reduce overall atmospheric radiative forcing. Fig. 1. True color image subset with superimposed gas plumes showing concentrations in ppmm. Left: AVIRIS-NG observed CH4 plumes from natural gas processing plant extending over 500 m downwind of multiple emissions sources. Right: Multiple CO2 plumes observed from coal-fired power plant.

Travel-time source-specific station correction improves location accuracy

Science.gov (United States)

Giuntini, Alessandra; Materni, Valerio; Chiappini, Stefano; Carluccio, Roberto; Console, Rodolfo; Chiappini, Massimo

2013-04-01

Accurate earthquake locations are crucial for investigating seismogenic processes, as well as for applications like verifying compliance to the Comprehensive Test Ban Treaty (CTBT). Earthquake location accuracy is related to the degree of knowledge about the 3-D structure of seismic wave velocity in the Earth. It is well known that modeling errors of calculated travel times may have the effect of shifting the computed epicenters far from the real locations by a distance even larger than the size of the statistical error ellipses, regardless of the accuracy in picking seismic phase arrivals. The consequences of large mislocations of seismic events in the context of the CTBT verification is particularly critical in order to trigger a possible On Site Inspection (OSI). In fact, the Treaty establishes that an OSI area cannot be larger than 1000 km2, and its larger linear dimension cannot be larger than 50 km. Moreover, depth accuracy is crucial for the application of the depth event screening criterion. In the present study, we develop a method of source-specific travel times corrections based on a set of well located events recorded by dense national seismic networks in seismically active regions. The applications concern seismic sequences recorded in Japan, Iran and Italy. We show that mislocations of the order of 10-20 km affecting the epicenters, as well as larger mislocations in hypocentral depths, calculated from a global seismic network and using the standard IASPEI91 travel times can be effectively removed by applying source-specific station corrections.

Location of an electric source facility and local area promotion

International Nuclear Information System (INIS)

Shimohirao, Isao

1999-01-01

Here were described on energy demand and supply, energy policy and local area promotion policy for basic problems important on location of electric source facilities. At present, co-existence business between electricity business and electric source location area is lacking in its activity. It seems to be necessary to enforce some systems to intend to promote it earnestly, and to effort to promote industry promotions such as introduction of some national projects, induction of electricity cost reduction for a means of business invitation, and so forth. And it is necessary to promote them under cooperations with electricity businesses, governments, universities and communities for the industrial promotion and fixation of the youth at local areas. In order to realize such necessities, further larger efforts are expected for national and local governments. (G.K.)

Plasma assisted growth of MoO{sub 3} films on different substrate locations relative to sublimation source

Energy Technology Data Exchange (ETDEWEB)

Sharma, Rabindar K., E-mail: rkrksharma6@gmail.com; Saini, Sujit K.; Kumar, Prabhat; Singh, Megha; Reddy, G. B. [Thin film laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi – 110016 (India)

2016-05-06

In the present paper, we reported the role of substrate locations relative to source on the growth of MoO{sub 3} films deposited on Ni coated glass substrates using plasma assisted sublimation process (PASP). According to the XRD and SEM results, substrate location is very crucial factor to control the morphology of MoO{sub 3} films and the best nanostructure growth (in terms of alignments and features) is obtained in case of Sample B (in which substrate is placed on source). The structural results point out that all films exhibit only orthorhombic phase of molybdenum oxide (i.e. α-MoO{sub 3})but the most preferential growth is recorded in Sample B due to the presence of intense peaks crossponding to only (0 k 0) family of crystal planes (k = 2, 4,6..). The Raman analysis again confirms the orthorhombic nature of MoO{sub 3} NFs and details of vibrational bondsin Sample B have been given in the present report. The MoO{sub 3} NFs show intense PL emission in wavelength range of 300-700 nm with three peaks located at 415, 490, and 523 nm in accordance to the improved crystallinity in Sample B.

Locating non-volcanic tremor along the San Andreas Fault using a multiple array source imaging technique

Science.gov (United States)

Ryberg, T.; Haberland, C.H.; Fuis, G.S.; Ellsworth, W.L.; Shelly, D.R.

2010-01-01

Non-volcanic tremor (NVT) has been observed at several subduction zones and at the San Andreas Fault (SAF). Tremor locations are commonly derived by cross-correlating envelope-transformed seismic traces in combination with source-scanning techniques. Recently, they have also been located by using relative relocations with master events, that is low-frequency earthquakes that are part of the tremor; locations are derived by conventional traveltime-based methods. Here we present a method to locate the sources of NVT using an imaging approach for multiple array data. The performance of the method is checked with synthetic tests and the relocation of earthquakes. We also applied the method to tremor occurring near Cholame, California. A set of small-aperture arrays (i.e. an array consisting of arrays) installed around Cholame provided the data set for this study. We observed several tremor episodes and located tremor sources in the vicinity of SAF. During individual tremor episodes, we observed a systematic change of source location, indicating rapid migration of the tremor source along SAF. ?? 2010 The Authors Geophysical Journal International ?? 2010 RAS.

Occupational exposure to natural sources of radiation

International Nuclear Information System (INIS)

Ortiz, T.; Sciocchetti, G.; Rannou, A.

1993-01-01

The most important natural sources of radiation are analyzed. The situation in France, Italy, and Spain concerning protection against natural radiation is described, including the identification of sources, and defined practices, organizations charged of national surveys and the responsibility of regulatory bodies and the role of operating management. The activities of the international organizations (ICRP, CEC and IAEA) are presented and discussed, and existing actions toward harmonization in the CEC, IAEA and other international programs is also discussed. (R.P.) 23 refs., 2 tabs

Return of naturally sourced Pb to Atlantic surface waters

NARCIS (Netherlands)

Bridgestock, L.; van de Flierdt, T.; Rehkämper, M.; Paul, P.; Middag, R.; Milne, A.; Lohan, M.C.; Baker, A.; Chance, R.; Khondoker, R.; Strekopytov, S.; Humphreys-Williams, E.; Achterberg, E.P.; Rijkenberg, M.J.A.; Gerringa, L.J.A.; De Baar, H.J.W.

2016-01-01

Anthropogenic emissions completely overwhelmed natural marine lead (Pb) sources duringthe past century, predominantly due to leaded petrol usage. Here, based on Pb isotopemeasurements, we reassess the importance of natural and anthropogenic Pb sources to thetropical North Atlantic following the

Radio Source Morphology: 'nature or nuture'?

Science.gov (United States)

Banfield, Julie; Emonts, Bjorn; O'Sullivan, Shane

2012-10-01

Radio sources, emanating from supermassive black-holes in the centres of active galaxies, display a large variety of morphological properties. It is a long-standing debate to what extent the differences between various types of radio sources are due to intrinsic properties of the central engine (`nature') or due to the properties of the interstellar medium that surrounds the central engine and host galaxy (`nurture'). Settling this `nature vs. nurture' debate for nearby radio galaxies, which can be studied in great detail, is vital for understanding the properties and evolution of radio galaxies throughout the Universe. We propose to observe the radio galaxy NGC 612 where previous observations have detected the presence of a large-scale HI bridge between the host galaxy and a nearby galaxy NGC 619. We request a total of 13 hrs in the 750m array-configuration to determine whether or not the 100 kpc-scale radio source morphology is directly related to the intergalactic distribution of neutral hydrogen gas.

Establishing Standards on Colors from Natural Sources.

Science.gov (United States)

Simon, James E; Decker, Eric A; Ferruzzi, Mario G; Giusti, M Monica; Mejia, Carla D; Goldschmidt, Mark; Talcott, Stephen T

2017-11-01

Color additives are applied to many food, drug, and cosmetic products. With up to 85% of consumer buying decisions potentially influenced by color, appropriate application of color additives and their safety is critical. Color additives are defined by the U.S. Federal Food, Drug, and Cosmetic Act (FD&C Act) as any dye, pigment, or substance that can impart color to a food, drug, or cosmetic or to the human body. Under current U.S. Food and Drug Administration (FDA) regulations, colors fall into 2 categories as those subject to an FDA certification process and those that are exempt from certification often referred to as "natural" colors by consumers because they are sourced from plants, minerals, and animals. Certified colors have been used for decades in food and beverage products, but consumer interest in natural colors is leading market applications. However, the popularity of natural colors has also opened a door for both unintentional and intentional economic adulteration. Whereas FDA certifications for synthetic dyes and lakes involve strict quality control, natural colors are not evaluated by the FDA and often lack clear definitions and industry accepted quality and safety specifications. A significant risk of adulteration of natural colors exists, ranging from simple misbranding or misuse of the term "natural" on a product label to potentially serious cases of physical, chemical, and/or microbial contamination from raw material sources, improper processing methods, or intentional postproduction adulteration. Consistent industry-wide safety standards are needed to address the manufacturing, processing, application, and international trade of colors from natural sources to ensure quality and safety throughout the supply chain. © 2017 Institute of Food Technologists®.

Bayesian statistics applied to the location of the source of explosions at Stromboli Volcano, Italy

Science.gov (United States)

Saccorotti, G.; Chouet, B.; Martini, M.; Scarpa, R.

1998-01-01

We present a method for determining the location and spatial extent of the source of explosions at Stromboli Volcano, Italy, based on a Bayesian inversion of the slowness vector derived from frequency-slowness analyses of array data. The method searches for source locations that minimize the error between the expected and observed slowness vectors. For a given set of model parameters, the conditional probability density function of slowness vectors is approximated by a Gaussian distribution of expected errors. The method is tested with synthetics using a five-layer velocity model derived for the north flank of Stromboli and a smoothed velocity model derived from a power-law approximation of the layered structure. Application to data from Stromboli allows for a detailed examination of uncertainties in source location due to experimental errors and incomplete knowledge of the Earth model. Although the solutions are not constrained in the radial direction, excellent resolution is achieved in both transverse and depth directions. Under the assumption that the horizontal extent of the source does not exceed the crater dimension, the 90% confidence region in the estimate of the explosive source location corresponds to a small volume extending from a depth of about 100 m to a maximum depth of about 300 m beneath the active vents, with a maximum likelihood source region located in the 120- to 180-m-depth interval.

Locating the Source of Atmospheric Contamination Based on Data From the Kori Field Tracer Experiment

Directory of Open Access Journals (Sweden)

Piotr Kopka

2015-01-01

Full Text Available Accidental releases of hazardous material into the atmosphere pose high risks to human health and the environment. Thus it would be valuable to develop an emergency reaction system which can recognize the probable location of the source based only on concentrations of the released substance as reported by a network of sensors. We apply a methodology combining Bayesian inference with Sequential Monte Carlo (SMC methods to the problem of locating the source of an atmospheric contaminant. The input data for this algorithm are the concentrations of a given substance gathered continuously in time. We employ this algorithm to locating a contamination source using data from a field tracer experiment covering the Kori nuclear site and conducted in May 2001. We use the second-order Closure Integrated PUFF Model (SCIPUFF of atmospheric dispersion as the forward model to predict concentrations at the sensors' locations. We demonstrate that the source of continuous contamination may be successfully located even in the very complicated, hilly terrain surrounding the Kori nuclear site. (original abstract

Identification of sources of aerosol particles in three locations in eastern Botswana

Science.gov (United States)

Chimidza, S.; Moloi, K.

2000-07-01

Airborne particles have been collected using a dichotomous virtual impactor at three different locations in the eastern part of Botswana: Serowe, Selibe-Phikwe, and Francistown. The particles were separated into two fractions (fine and coarse). Sampling at the three locations was done consecutively during the months of July and August, which are usually dry and stable. The sampling time for each sample was 12 hours during the day. For elemental composition, energy-dispersive x-ray fluorescence technique was used. Correlations and principal component analysis with varimax rotation were used to identify major sources of aerosol particles. In all the three places, soil was found to be the main source of aerosol particles. A copper-nickel mine and smelter at Selibe-Phikwe was found to be not only a source of copper and nickel particles in Selibe-Phikwe but also a source of these particles in far places like Serowe. In Selibe-Phikwe and Francistown, car exhaust was found to be the major source of fine particles of lead and bromine.

Learning to locate an odour source with a mobile robot

OpenAIRE

Duckett, T.; Axelsson, M.; Saffiotti, A.

2001-01-01

We address the problem of enabling a mobile robot to locate a stationary odour source using an electronic nose constructed from gas sensors. On the hardware side, we use a stereo nose architecture consisting of two parallel chambers, each containing an identical set of sensors. On the software side, we use a recurrent artificial neural network to learn the direction to a stationary source from a time series of sensor readings. This contrasts with previous approaches, that rely on the existenc...

Planar location of the simulative acoustic source based on fiber optic sensor array

Science.gov (United States)

Liang, Yi-Jun; Liu, Jun-feng; Zhang, Qiao-ping; Mu, Lin-lin

2010-06-01

A fiber optic sensor array which is structured by four Sagnac fiber optic sensors is proposed to detect and locate a simulative source of acoustic emission (AE). The sensing loops of Sagnac interferometer (SI) are regarded as point sensors as their small size. Based on the derived output light intensity expression of SI, the optimum work condition of the Sagnac fiber optic sensor is discussed through the simulation of MATLAB. Four sensors are respectively placed on a steel plate to structure the sensor array and the location algorithms are expatiated. When an impact is generated by an artificial AE source at any position of the plate, the AE signal will be detected by four sensors at different times. With the help of a single chip microcomputer (SCM) which can calculate the position of the AE source and display it on LED, we have implemented an intelligent detection and location.

An automated multi-scale network-based scheme for detection and location of seismic sources

Science.gov (United States)

Poiata, N.; Aden-Antoniow, F.; Satriano, C.; Bernard, P.; Vilotte, J. P.; Obara, K.

2017-12-01

We present a recently developed method - BackTrackBB (Poiata et al. 2016) - allowing to image energy radiation from different seismic sources (e.g., earthquakes, LFEs, tremors) in different tectonic environments using continuous seismic records. The method exploits multi-scale frequency-selective coherence in the wave field, recorded by regional seismic networks or local arrays. The detection and location scheme is based on space-time reconstruction of the seismic sources through an imaging function built from the sum of station-pair time-delay likelihood functions, projected onto theoretical 3D time-delay grids. This imaging function is interpreted as the location likelihood of the seismic source. A signal pre-processing step constructs a multi-band statistical representation of the non stationary signal, i.e. time series, by means of higher-order statistics or energy envelope characteristic functions. Such signal-processing is designed to detect in time signal transients - of different scales and a priori unknown predominant frequency - potentially associated with a variety of sources (e.g., earthquakes, LFE, tremors), and to improve the performance and the robustness of the detection-and-location location step. The initial detection-location, based on a single phase analysis with the P- or S-phase only, can then be improved recursively in a station selection scheme. This scheme - exploiting the 3-component records - makes use of P- and S-phase characteristic functions, extracted after a polarization analysis of the event waveforms, and combines the single phase imaging functions with the S-P differential imaging functions. The performance of the method is demonstrated here in different tectonic environments: (1) analysis of the one year long precursory phase of 2014 Iquique earthquake in Chile; (2) detection and location of tectonic tremor sources and low-frequency earthquakes during the multiple episodes of tectonic tremor activity in southwestern Japan.

An efficient closed-form solution for acoustic emission source location in three-dimensional structures

Directory of Open Access Journals (Sweden)

Xibing Li

2014-02-01

Full Text Available This paper presents an efficient closed-form solution (ECS for acoustic emission(AE source location in three-dimensional structures using time difference of arrival (TDOA measurements from N receivers, N ≥ 6. The nonlinear location equations of TDOA are simplified to linear equations. The unique analytical solution of AE sources for unknown velocity system is obtained by solving the linear equations. The proposed ECS method successfully solved the problems of location errors resulting from measured deviations of velocity as well as the existence and multiplicity of solutions induced by calculations of square roots in existed close-form methods.

Community Assessment of Natural Food Sources of Vitamin A ...

International Development Research Centre (IDRC) Digital Library (Canada)

Community Assessment of Natural Food Sources of Vitamin A: Guidelines for an Ethnographic Protocol. Book cover Community Assessment of Natural Food Sources of Vitamin A: Guidelines for an Ethnographic. Auteur(s) : L. Blum, P.J. Pelto, G.H. Pelto, and H.V. Kuhnlein. Maison(s) d'édition : INFDC, IDRC. 1 janvier 1997.

Community Assessment of Natural Food Sources of Vitamin A ...

International Development Research Centre (IDRC) Digital Library (Canada)

1 janv. 1997 ... Community Assessment of Natural Food Sources of Vitamin A : Guidelines for an Ethnographic Protocol. Couverture du livre Community Assessment of Natural Food Sources of Vitamin A : Guidelines for an. Auteur(s):. L. Blum, P.J. Pelto, G.H. Pelto et H.V. Kuhnlein. Maison(s) d'édition: INFDC, CRDI.

Location iron-Mantua an area with high securities gives natural radioactivity

International Nuclear Information System (INIS)

Alcaide Orpi, J.; Oliveira Acosta, J.; Valdes Hernadez, G.M.; Leal Ramirez, M.R.; Blanco Jorrin, N.

1998-01-01

The work shows the high natural radioactivity and the concentration to the natural radioelements (U,Th, Ra, K) it is exists in the sulfurous Hierro Mantua location. The objective is to know the possible radiological risk to that would be subjected the workers during the mining exploitation, because the high gamma radiation doses that could receive and to the risks product the internal contamination due to the inhalation the radon 222 and uranium aerosols and particles

The Opponent Channel Population Code of Sound Location Is an Efficient Representation of Natural Binaural Sounds

Science.gov (United States)

Młynarski, Wiktor

2015-01-01

In mammalian auditory cortex, sound source position is represented by a population of broadly tuned neurons whose firing is modulated by sounds located at all positions surrounding the animal. Peaks of their tuning curves are concentrated at lateral position, while their slopes are steepest at the interaural midline, allowing for the maximum localization accuracy in that area. These experimental observations contradict initial assumptions that the auditory space is represented as a topographic cortical map. It has been suggested that a “panoramic” code has evolved to match specific demands of the sound localization task. This work provides evidence suggesting that properties of spatial auditory neurons identified experimentally follow from a general design principle- learning a sparse, efficient representation of natural stimuli. Natural binaural sounds were recorded and served as input to a hierarchical sparse-coding model. In the first layer, left and right ear sounds were separately encoded by a population of complex-valued basis functions which separated phase and amplitude. Both parameters are known to carry information relevant for spatial hearing. Monaural input converged in the second layer, which learned a joint representation of amplitude and interaural phase difference. Spatial selectivity of each second-layer unit was measured by exposing the model to natural sound sources recorded at different positions. Obtained tuning curves match well tuning characteristics of neurons in the mammalian auditory cortex. This study connects neuronal coding of the auditory space with natural stimulus statistics and generates new experimental predictions. Moreover, results presented here suggest that cortical regions with seemingly different functions may implement the same computational strategy-efficient coding. PMID:25996373

Estimation of microwave source location in precipitating electron fluxes according to Viking satellite data

International Nuclear Information System (INIS)

Khrushchinskij, A.A.; Ostapenko, A.A.; Gustafsson, G.; Eliasson, L.; Sandal, I.

1989-01-01

According to the Viking satellite data on electron fluxes in the 0.1-300 keV energy range, the microburst source location is estimated. On the basis of experimental delays in detected peaks in different energy channels and theoretical calculations of these delays within the dipole field model (L∼ 4-5.5), it is shown that the most probable source location is the equatorial region with the centre, 5-10 0 shifted towards the ionosphere

Acoustic emission non-destructive testing of structures using source location techniques.

Energy Technology Data Exchange (ETDEWEB)

Beattie, Alan G.

2013-09-01

The technology of acoustic emission (AE) testing has been advanced and used at Sandia for the past 40 years. AE has been used on structures including pressure vessels, fire bottles, wind turbines, gas wells, nuclear weapons, and solar collectors. This monograph begins with background topics in acoustics and instrumentation and then focuses on current acoustic emission technology. It covers the overall design and system setups for a test, with a wind turbine blade as the object. Test analysis is discussed with an emphasis on source location. Three test examples are presented, two on experimental wind turbine blades and one on aircraft fire extinguisher bottles. Finally, the code for a FORTRAN source location program is given as an example of a working analysis program. Throughout the document, the stress is on actual testing of real structures, not on laboratory experiments.

Coded aperture detector for high precision gamma-ray burst source locations

International Nuclear Information System (INIS)

Helmken, H.; Gorenstein, P.

1977-01-01

Coded aperture collimators in conjunction with position-sensitive detectors are very useful in the study of transient phenomenon because they combine broad field of view, high sensitivity, and an ability for precise source locations. Since the preceeding conference, a series of computer simulations of various detector designs have been carried out with the aid of a CDC 6400. Particular emphasis was placed on the development of a unit consisting of a one-dimensional random or periodic collimator in conjunction with a two-dimensional position-sensitive Xenon proportional counter. A configuration involving four of these units has been incorporated into the preliminary design study of the Transient Explorer (ATREX) satellite and are applicable to any SAS or HEAO type satellite mission. Results of this study, including detector response, fields of view, and source location precision, will be presented

Methods to identify and locate spent radiation sources; Metodos para la identificacion y localizacion de fuentes radiactivas gastadas

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

The objective of this manual is to provide essential guidance to Member States with nuclear applications involving the use of a wide range of sealed radiation sources on the practical task of physically locating spent radiation sources not properly accounted for. Advice is also provided to render the located source safe on location. Refs, figs, tabs.

Competition in spatial location models

NARCIS (Netherlands)

Webers, H.M.

1996-01-01

Models of spatial competition are designed and analyzed to describe the fact that space, by its very nature, is a source of market power. This field of research, lying at the interface of game theory and economics, has attracted much interest because location problems are related to many aspects of

A Comparative Study Of Source Location And Depth Estimates From ...

African Journals Online (AJOL)

... the analytic signal amplitude (ASA) and the local wave number (LWN) of the total intensity magnetic field. In this study, a synthetic magnetic field due to four buried dipoles was analysed to show that estimates of source location and depth can be improved significantly by reducing the data to the pole prior to the application ...

Joint Source Location and Focal Mechanism Inversion: efficiency, accuracy and applications

Science.gov (United States)

Liang, C.; Yu, Y.

2017-12-01

The analysis of induced seismicity has become a common practice to evaluate the results of hydraulic fracturing treatment. Liang et al (2016) proposed a joint Source Scanning Algorithms (jSSA for short) to obtain microseismic events and focal mechanisms simultaneously. The jSSA is superior over traditional SSA in many aspects, but the computation cost is too significant to be applied in real time monitoring. In this study, we have developed several scanning schemas to reduce computation time. A multi-stage scanning schema is proved to be able to improve the efficiency significantly while also retain its accuracy. A series of tests have been carried out by using both real field data and synthetic data to evaluate the accuracy of the method and its dependence on noise level, source depths, focal mechanisms and other factors. The surface-based arrays have better constraints on horizontal location errors (0.5). For sources with varying rakes, dips, strikes and depths, the errors are mostly controlled by the partition of positive and negative polarities in different quadrants. More evenly partitioned polarities in different quadrants yield better results in both locations and focal mechanisms. Nevertheless, even with bad resolutions for some FMs, the optimized jSSA method can still improve location accuracies significantly. Based on much more densely distributed events and focal mechanisms, a gridded stress inversion is conducted to get a evenly distributed stress field. The full potential of the jSSA has yet to be explored in different directions, especially in earthquake seismology as seismic array becoming incleasingly dense.

AE source location by neural networks with arrival time profiles

Czech Academy of Sciences Publication Activity Database

Chlada, Milan; Blaháček, Michal; Převorovský, Zdeněk

2009-01-01

Roč. 19, č. 2 (2009), s. 4-4 ISSN 1213-3825. [NDT in PROGRESS. 12.11.2009-14.11.2009, Praha] R&D Projects: GA ČR GA101/07/1518; GA ČR GA106/07/1393 Institutional research plan: CEZ:AV0Z20760514 Keywords : acoustic emission * source location * artificial neural networks Subject RIV: BI - Acoustics www.cndt.cz

Characteristics and locations of sources

International Nuclear Information System (INIS)

Lahtinen, J.; Poellaenen, R.; Toivonen, H.

1997-01-01

Ten artificial radiation sources were placed in the terrain in order to test the capability of airborne measuring teams to detect them. One of the sources was a line source, others were point sources (three of them collimated). The radionuclides used in the sources were 60 Co, 137 Cs, 99m Tc and 192 Ir. The source activities ranged from about 26 MBq (one of the cobalt sources) to 0.56 TBq (iridium). (au)

Energy based source location by using acoustic emission for damage detection in steel and composite CNG tank

Energy Technology Data Exchange (ETDEWEB)

Kim, Il Sik; Han, Byeong Hee; Park, Choon Su; Yoon, Dong Jin [Center for Safety Measurements, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

2015-10-15

Acoustic emission (AE) is an effective nondestructive test that uses transient elastic wave generated by the rapid release of energy within a material to detect any further growth or expansion of existing defects. Over the past decades, because of environmental issues, the use of compressed natural gas (CNG) as an alternative fuel for vehicles is increasing because of environmental issues. For this reason, the importance and necessity of detecting defects on a CNG fuel tank has also come to the fore. The conventional AE method used for source location is highly affected by the wave speed on the structure, and this creates problems in inspecting a composite CNG fuel tank. Because the speed and dispersion characteristics of the wave are different according to direction of structure and laminated layers. In this study, both the conventional AE method and the energy based contour map method were used for source location. This new method based on pre-acquired D/B was used for overcoming the limitation of damage localization in a composite CNG fuel tank specimen which consists of a steel liner cylinder overwrapped by GFRP. From the experimental results, it is observed that the damage localization is determined with a small error at all tested points by using the energy based contour map method, while there were a number of mis-locations or large errors at many tested points by using the conventional AE method. Therefore, the energy based contour map method used in this work is more suitable technology for inspecting composite structures.

Characteristics and locations of sources

Energy Technology Data Exchange (ETDEWEB)

Lahtinen, J.; Poellaenen, R.; Toivonen, H. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

1997-12-31

Ten artificial radiation sources were placed in the terrain in order to test the capability of airborne measuring teams to detect them. One of the sources was a line source, others were point sources (three of them collimated). The radionuclides used in the sources were {sup 60}Co, {sup 137}Cs, {sup 99m}Tc and {sup 192}Ir. The source activities ranged from about 26 MBq (one of the cobalt sources) to 0.56 TBq (iridium). (au).

Characteristics and locations of sources

Energy Technology Data Exchange (ETDEWEB)

Lahtinen, J; Poellaenen, R; Toivonen, H [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

1998-12-31

Ten artificial radiation sources were placed in the terrain in order to test the capability of airborne measuring teams to detect them. One of the sources was a line source, others were point sources (three of them collimated). The radionuclides used in the sources were {sup 60}Co, {sup 137}Cs, {sup 99m}Tc and {sup 192}Ir. The source activities ranged from about 26 MBq (one of the cobalt sources) to 0.56 TBq (iridium). (au).

Chemometric Analysis for Pollution Source Assessment of Harbour Sediments in Arctic Locations

DEFF Research Database (Denmark)

Pedersen, Kristine B.; Lejon, Tore; Jensen, Pernille Erland

2015-01-01

Pollution levels, pollutant distribution and potential source assessments based on multivariate analysis (chemometrics) were made for harbour sediments from two Arctic locations; Hammerfest in Norway and Sisimiut in Greenland. High levels of heavy metals were detected in addition to organic...... pollutants. Preliminary assessments based on principal component analysis (PCA) revealed different sources and pollutant distribution in the sediments of the two harbours. Tributyltin (TBT) was, however, found to originate from point source(s), and the highest concentrations of TBT in both harbours were...... indicated relation primarily to German, Russian and American mixtures in Hammerfest; and American, Russian and Japanese mixtures in Sisimiut. PCA was shown to be an important tool for identifying pollutant sources and differences in pollutant composition in relation to sediment characteristics....

Stress Tolerance Variations in Saccharomyces cerevisiae Strains from Diverse Ecological Sources and Geographical Locations.

Directory of Open Access Journals (Sweden)

Yan-Lin Zheng

Full Text Available The budding yeast Saccharomyces cerevisiae is a platform organism for bioethanol production from various feedstocks and robust strains are desirable for efficient fermentation because yeast cells inevitably encounter stressors during the process. Recently, diverse S. cerevisiae lineages were identified, which provided novel resources for understanding stress tolerance variations and related shaping factors in the yeast. This study characterized the tolerance of diverse S. cerevisiae strains to the stressors of high ethanol concentrations, temperature shocks, and osmotic stress. The results showed that the isolates from human-associated environments overall presented a higher level of stress tolerance compared with those from forests spared anthropogenic influences. Statistical analyses indicated that the variations of stress tolerance were significantly correlated with both ecological sources and geographical locations of the strains. This study provides guidelines for selection of robust S. cerevisiae strains for bioethanol production from nature.

An FBG acoustic emission source locating system based on PHAT and GA

Science.gov (United States)

Shen, Jing-shi; Zeng, Xiao-dong; Li, Wei; Jiang, Ming-shun

2017-09-01

Using the acoustic emission locating technology to monitor the health of the structure is important for ensuring the continuous and healthy operation of the complex engineering structures and large mechanical equipment. In this paper, four fiber Bragg grating (FBG) sensors are used to establish the sensor array to locate the acoustic emission source. Firstly, the nonlinear locating equations are established based on the principle of acoustic emission, and the solution of these equations is transformed into an optimization problem. Secondly, time difference extraction algorithm based on the phase transform (PHAT) weighted generalized cross correlation provides the necessary conditions for the accurate localization. Finally, the genetic algorithm (GA) is used to solve the optimization model. In this paper, twenty points are tested in the marble plate surface, and the results show that the absolute locating error is within the range of 10 mm, which proves the accuracy of this locating method.

Source apportionment and location by selective wind sampling and Positive Matrix Factorization.

Science.gov (United States)

Venturini, Elisa; Vassura, Ivano; Raffo, Simona; Ferroni, Laura; Bernardi, Elena; Passarini, Fabrizio

2014-10-01

In order to determine the pollution sources in a suburban area and identify the main direction of their origin, PM2.5 was collected with samplers coupled with a wind select sensor and then subjected to Positive Matrix Factorization (PMF) analysis. In each sample, soluble ions, organic carbon, elemental carbon, levoglucosan, metals, and Polycyclic Aromatic Hydrocarbons (PAHs) were determined. PMF results identified six main sources affecting the area: natural gas home appliances, motor vehicles, regional transport, biomass combustion, manufacturing activities, and secondary aerosol. The connection of factor temporal trends with other parameters (i.e., temperature, PM2.5 concentration, and photochemical processes) confirms factor attributions. PMF analysis indicated that the main source of PM2.5 in the area is secondary aerosol. This should be mainly due to regional contributions, owing to both the secondary nature of the source itself and the higher concentration registered in inland air masses. The motor vehicle emission source contribution is also important. This source likely has a prevalent local origin. The most toxic determined components, i.e., PAHs, Cd, Pb, and Ni, are mainly due to vehicular traffic. Even if this is not the main source in the study area, it is the one of greatest concern. The application of PMF analysis to PM2.5 collected with this new sampling technique made it possible to obtain more detailed results on the sources affecting the area compared to a classical PMF analysis.

Bioactive natural products from novel microbial sources.

Science.gov (United States)

Challinor, Victoria L; Bode, Helge B

2015-09-01

Despite the importance of microbial natural products for human health, only a few bacterial genera have been mined for the new natural products needed to overcome the urgent threat of antibiotic resistance. This is surprising, given that genome sequencing projects have revealed that the capability to produce natural products is not a rare feature among bacteria. Even the bacteria occurring in the human microbiome produce potent antibiotics, and thus potentially are an untapped resource for novel compounds, potentially with new activities. This review highlights examples of bacteria that should be considered new sources of natural products, including anaerobes, pathogens, and symbionts of humans, insects, and nematodes. Exploitation of these producer strains, combined with advances in modern natural product research methodology, has the potential to open the way for a new golden age of microbial therapeutics. © 2015 New York Academy of Sciences.

Natural selection and family X location interaction in the common (dry bean plant

Directory of Open Access Journals (Sweden)

Luís Henrique Pirola

2002-01-01

Full Text Available Natural selection takes place while advancing generations of segregant populations of self pollinating species by the population (bulk method. There is evidence that it maintains the individuals with greater grain yield. The question arises whether natural selection preserves the individuals which are more adapted only to the environment where the generation advance occurred, that is, if it contributes to increasing the genotype x environment interaction in the family assessment. This study was carried out to check this hypothesis in the common bean plant using families derived from a segregating population from a cross between the Carioca MG x ESAL 686 cultivars. The segregating populations increase in homozygosity was obtained by the population (bulk method until the F14 generation, in three distinct locations in Minas Gerais state: Lavras, Lambari and Patos de Minas. Forty-seven F14:15 families were randomly taken from the population in each location and later multiplied to obtain F14:16 families. These families were jointly assessed with three controls using a triple 12 x 12 lattice design in the three locations of generation advance in the wet season of 1998/1999. All the estimated parameters showed that while advancing segregant populations by the population (bulk method, natural selection acted to preserve the individuals which are more adapted to the environment in which they were advanced.

Simultaneous head tissue conductivity and EEG source location estimation.

Science.gov (United States)

Akalin Acar, Zeynep; Acar, Can E; Makeig, Scott

2016-01-01

Accurate electroencephalographic (EEG) source localization requires an electrical head model incorporating accurate geometries and conductivity values for the major head tissues. While consistent conductivity values have been reported for scalp, brain, and cerebrospinal fluid, measured brain-to-skull conductivity ratio (BSCR) estimates have varied between 8 and 80, likely reflecting both inter-subject and measurement method differences. In simulations, mis-estimation of skull conductivity can produce source localization errors as large as 3cm. Here, we describe an iterative gradient-based approach to Simultaneous tissue Conductivity And source Location Estimation (SCALE). The scalp projection maps used by SCALE are obtained from near-dipolar effective EEG sources found by adequate independent component analysis (ICA) decomposition of sufficient high-density EEG data. We applied SCALE to simulated scalp projections of 15cm(2)-scale cortical patch sources in an MR image-based electrical head model with simulated BSCR of 30. Initialized either with a BSCR of 80 or 20, SCALE estimated BSCR as 32.6. In Adaptive Mixture ICA (AMICA) decompositions of (45-min, 128-channel) EEG data from two young adults we identified sets of 13 independent components having near-dipolar scalp maps compatible with a single cortical source patch. Again initialized with either BSCR 80 or 25, SCALE gave BSCR estimates of 34 and 54 for the two subjects respectively. The ability to accurately estimate skull conductivity non-invasively from any well-recorded EEG data in combination with a stable and non-invasively acquired MR imaging-derived electrical head model could remove a critical barrier to using EEG as a sub-cm(2)-scale accurate 3-D functional cortical imaging modality. Copyright © 2015 Elsevier Inc. All rights reserved.

The location of uranium in source rocks and sites of secondary deposition at the Needle's Eye natural analogue site, Dumfries and Galloway

International Nuclear Information System (INIS)

Basham, I.R.; Hyslop, E.K.; Milodowski, A.E.; Pearce, J.M.

1989-08-01

The British Geological Survey has been conducting a co-ordinated research programme at the natural analogue site of Needle's Eye at Southwick on the Solway coast in SW Scotland. This study of a naturally radioactive geochemical system has been carried out with the aim of improving our confidence in using predictive models of radionuclide migration in the geosphere. This report describes results of integrated mineralogical techniques which have been applied to the study of both the 'source-term' and sites of secondary accumulation of uranium. Pitchblende in a polymetallic-carbonate breccia vein exposed in ancient sea-cliffs is the main source of labile uranium although other uranium-bearing minerals present in the granodiorite and hornfelsed siltstone host-rocks present probable ancillary leachable sites. In keeping with the complex chemistry of the primary sulphide-rich mineralization, a large variety of secondary U minerals has been recorded among which arsenates and hydrous silicates appear to predominate. Uranium transported in groundwaters draining the cliffs has accumulated in organic-rich estuarine/intertidal mudflat sediments of Quaternary age. Charged particle track registration techniques have demonstrated convincingly the effectiveness of humidified organic matter in retarding uranium transport and, coupled with scanning electron microscopy, have indicated an important role of living plants and bacteria in uranium uptake and concentration. (author)

Site Characterization of the Source Physics Experiment Phase II Location Using Seismic Reflection Data

Science.gov (United States)

Sexton, E. A.; Snelson, C. M.; Chipman, V.; Emer, D. F.; White, R. L.; Emmitt, R.; Wright, A. A.; Drellack, S.; Huckins-Gang, H.; Mercadante, J.; Floyd, M.; McGowin, C.; Cothrun, C.; Bonal, N.

2013-12-01

An objective of the Source Physics Experiment (SPE) is to identify low-yield nuclear explosions from a regional distance. Low-yield nuclear explosions can often be difficult to discriminate among the clutter of natural and man-made explosive events (e.g., earthquakes and mine blasts). The SPE is broken into three phases. Phase I has provided the first of the physics-based data to test the empirical models that have been used to discriminate nuclear events. The Phase I series of tests were placed within a highly fractured granite body. The evolution of the project has led to development of Phase II, to be placed within the opposite end member of geology, an alluvium environment, thereby increasing the database of waveforms to build upon in the discrimination models. Both the granite and alluvium sites have hosted nearby nuclear tests, which provide comparisons for the chemical test data. Phase III of the SPE is yet to be determined. For Phase II of the experiment, characterization of the location is required to develop the geologic/geophysical models for the execution of the experiment. Criteria for the location are alluvium thickness of approximately 170 m and a water table below 170 m; minimal fracturing would be ideal. A P-wave mini-vibroseis survey was conducted at a potential site in alluvium to map out the subsurface geology. The seismic reflection profile consisted of 168 geophone stations, spaced 5 m apart. The mini-vibe was a 7,000-lb peak-force source, starting 57.5 m off the north end of the profile and ending 57.5 m past the southern-most geophone. The length of the profile was 835 m. The source points were placed every 5 m, equally spaced between geophones to reduce clipping. The vibroseis sweep was from 20 Hz down to 180 Hz over 8 seconds, and four sweeps were stacked at each shot location. The shot gathers show high signal-to-noise ratios with clear first arrivals across the entire spread and the suggestion of some shallow reflectors. The data were

Influence of Injector Location on Part-Load Performance Characteristics of Natural Gas Direct-Injection in a Spark Ignition Engine

Energy Technology Data Exchange (ETDEWEB)

Sevik, James [Argonne National Lab. (ANL), Argonne, IL (United States); Pamminger, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Wallner, Thomas [Argonne National Lab. (ANL), Argonne, IL (United States); Scarcelli, Riccardo [Argonne National Lab. (ANL), Argonne, IL (United States); Boyer, Brad [Ford Motor Co., Detroit, MI (United States); Wooldridge, Steven [Ford Motor Co., Detroit, MI (United States); Hall, Carrie [Illinois Inst. of Technology, Chicago, IL (United States); Miers, Scott [Michigan Technological Univ., Houghton, MI (United States)

2016-04-05

Interest in natural gas as an alternative fuel source to petroleum fuels for light-duty vehicle applications has increased due to its domestic availability and stable price compared to gasoline. With its higher hydrogen-to-carbon ratio, natural gas has the potential to reduce engine out carbon dioxide emissions, which has shown to be a strong greenhouse gas contributor. For part-load conditions, the lower flame speeds of natural gas can lead to an increased duration in the inflammation process with traditional port-injection. Direct-injection of natural gas can increase in-cylinder turbulence and has the potential to reduce problems typically associated with port-injection of natural gas, such as lower flame speeds and poor dilution tolerance. A study was designed and executed to investigate the effects of direct-injection of natural gas at part-load conditions. Steady-state tests were performed on a single-cylinder research engine representative of current gasoline direct-injection engines. Tests were performed with direct-injection in the central and side location. The start of injection was varied under stoichiometric conditions in order to study the effects on the mixture formation process. In addition, exhaust gas recirculation was introduced at select conditions in order to investigate the dilution tolerance. Relevant combustion metrics were then analyzed for each scenario. Experimental results suggest that regardless of the injector location, varying the start of injection has a strong impact on the mixture formation process. Delaying the start of injection from 300 to 120°CA BTDC can reduce the early flame development process by nearly 15°CA. While injecting into the cylinder after the intake valves have closed has shown to produce the fastest combustion process, this does not necessarily lead to the highest efficiency, due to increases in pumping and wall heat losses. When comparing the two injection configurations, the side location shows the best

Source location of chorus emissions observed by Cluster

Directory of Open Access Journals (Sweden)

M. Parrot

Full Text Available One of the objectives of the Cluster mission is to study sources of various electromagnetic waves using the four satellites. This paper describes the methods we have applied to data recorded from the STAFF spectrum analyser. This instrument provides the cross spectral matrix of three magnetic and two electric field components. This spectral matrix is analysed to determine, for each satellite, the direction of the wave normal relative to the Earth’s magnetic field as a function of frequency and of time. Due to the Cluster orbit, chorus emissions are often observed close to perigee, and the data analysis determines the direction of these waves. Three events observed during different levels of magnetic activity are reported. It is shown that the component of the Poynting vector parallel to the magnetic field changes its sense when the satellites cross the magnetic equator, which indicates that the chorus waves propagate away from the equator. Detailed analysis indicates that the source is located in close vicinity of the plane of the geomagnetic equator.

Key words. Magnetospheric physics (plasma waves and instabilities; storms and substorms; Space plasma physics (waves and instabilities

Locating and Quantifying Broadband Fan Sources Using In-Duct Microphones

Science.gov (United States)

Dougherty, Robert P.; Walker, Bruce E.; Sutliff, Daniel L.

2010-01-01

In-duct beamforming techniques have been developed for locating broadband noise sources on a low-speed fan and quantifying the acoustic power in the inlet and aft fan ducts. The NASA Glenn Research Center's Advanced Noise Control Fan was used as a test bed. Several of the blades were modified to provide a broadband source to evaluate the efficacy of the in-duct beamforming technique. Phased arrays consisting of rings and line arrays of microphones were employed. For the imaging, the data were mathematically resampled in the frame of reference of the rotating fan. For both the imaging and power measurement steps, array steering vectors were computed using annular duct modal expansions, selected subsets of the cross spectral matrix elements were used, and the DAMAS and CLEAN-SC deconvolution algorithms were applied.

Seasonal and Spatial Variability of Anthropogenic and Natural Factors Influencing Groundwater Quality Based on Source Apportionment

Directory of Open Access Journals (Sweden)

Xueru Guo

2018-02-01

Full Text Available Globally, groundwater resources are being deteriorated by rapid social development. Thus, there is an urgent need to assess the combined impacts of natural and enhanced anthropogenic sources on groundwater chemistry. The aim of this study was to identify seasonal characteristics and spatial variations in anthropogenic and natural effects, to improve the understanding of major hydrogeochemical processes based on source apportionment. 34 groundwater points located in a riverside groundwater resource area in northeast China were sampled during the wet and dry seasons in 2015. Using principal component analysis and factor analysis, 4 principal components (PCs were extracted from 16 groundwater parameters. Three of the PCs were water-rock interaction (PC1, geogenic Fe and Mn (PC2, and agricultural pollution (PC3. A remarkable difference (PC4 was organic pollution originating from negative anthropogenic effects during the wet season, and geogenic F enrichment during the dry season. Groundwater exploitation resulted in dramatic depression cone with higher hydraulic gradient around the water source area. It not only intensified dissolution of calcite, dolomite, gypsum, Fe, Mn and fluorine minerals, but also induced more surface water recharge for the water source area. The spatial distribution of the PCs also suggested the center of the study area was extremely vulnerable to contamination by Fe, Mn, COD, and F−.

The location of uranium in source rocks and sites of secondary deposition at the Needle's Eye natural analogue site, Dumfries and Galloway

International Nuclear Information System (INIS)

Basham, I.R.; Hyslop, E.K.; Milodowski, A.E.; Pearce, J.M.

1991-01-01

The British Geological Survey has been conducting a coordinated research programme at the natural analogue site of Needle's Eye at Southwick on the Solway coast in south-west Scotland. This study of a naturally radioactive geochemical system has been carried out with the aim of improving our confidence in using predictive models of radionuclide migration in the geosphere. This report describes results of integrated mineralogical techniques which have been applied to the study of both the source-term and sites of secondary accumulation of uranium. Pitchblende in a polymetallic-carbonate breccia vein exposed in ancient sea-cliffs is the main source of labile uranium although other uranium-bearing minerals present in the granodiorite and hornfelsed siltstone host-rocks present probable ancillary leachable sites. In keeping with the complex chemistry of the primary sulphide-rich mineralization, a large variety of secondary U minerals has been recorded among which arsenates and hydrous silicates appear to predominate. Uranium transported in groundwaters draining the cliffs has accumulated in organic-rich estuarine/intertidal mudflat sediments of Quaternary age. Charged particle track registration techniques have demonstrated convincingly the effectiveness of humified organic matter in retarding uranium transport and, coupled with scanning electron microscopy, have indicated the important role of living plants and bacteria in uranium uptake and concentration. Computer codes used: CHEMVAL; CHEMTARD 5 figs.; 64 plates; 37 refs

High-resolution and super stacking of time-reversal mirrors in locating seismic sources

KAUST Repository

Cao, Weiping; Hanafy, Sherif M.; Schuster, Gerard T.; Zhan, Ge; Boonyasiriwat, Chaiwoot

2011-01-01

Time reversal mirrors can be used to backpropagate and refocus incident wavefields to their actual source location, with the subsequent benefits of imaging with high-resolution and super-stacking properties. These benefits of time reversal mirrors

High-resolution and super stacking of time-reversal mirrors in locating seismic sources

KAUST Repository

Cao, Weiping

2011-07-08

Time reversal mirrors can be used to backpropagate and refocus incident wavefields to their actual source location, with the subsequent benefits of imaging with high-resolution and super-stacking properties. These benefits of time reversal mirrors have been previously verified with computer simulations and laboratory experiments but not with exploration-scale seismic data. We now demonstrate the high-resolution and the super-stacking properties in locating seismic sources with field seismic data that include multiple scattering. Tests on both synthetic data and field data show that a time reversal mirror has the potential to exceed the Rayleigh resolution limit by factors of 4 or more. Results also show that a time reversal mirror has a significant resilience to strong Gaussian noise and that accurate imaging of source locations from passive seismic data can be accomplished with traces having signal-to-noise ratios as low as 0.001. Synthetic tests also demonstrate that time reversal mirrors can sometimes enhance the signal by a factor proportional to the square root of the product of the number of traces, denoted as N and the number of events in the traces. This enhancement property is denoted as super-stacking and greatly exceeds the classical signal-to-noise enhancement factor of. High-resolution and super-stacking are properties also enjoyed by seismic interferometry and reverse-time migration with the exact velocity model. © 2011 European Association of Geoscientists & Engineers.

Volatile organic compounds (VOCs) in air from Nisyros Island (Dodecanese Archipelago, Greece): Natural versus anthropogenic sources

International Nuclear Information System (INIS)

Tassi, F.; Capecchiacci, F.; Giannini, L.; Vougioukalakis, G.E.; Vaselli, O.

2013-01-01

This study presents the chemical composition of VOCs in air and gas discharges collected at Nisyros Island (Dodecanese Archipelago, Greece). The main goals are i) to discriminate between natural and anthropogenic VOC sources and ii) to evaluate their impact on local air quality. Up to 63 different VOCs were recognized and quantitatively determined in 6 fumaroles and 19 air samples collected in the Lakki caldera, where fumarolic emissions are located, and the outer ring of the island, including the Mandraki village and the main harbor. Air samples from the crater area show significant concentrations of alkanes, alkenes, cyclic, aromatics, and S- and O-bearing heterocycles directly deriving from the hydrothermal system, as well as secondary O-bearing compounds from oxidation of primary VOCs. At Mandraki village, C 6 H 6 /Σ(methylated aromatics) and Σ(linear)/Σ(branched) alkanes ratios 2 O–CO 2 –H 2 S rich and discharge a large variety of VOC species. •Benzene/toluene ratios identify anthropogenic and natural sources of VOCs in air. •Aldehydes in air are produced by oxidation of alkanes and alkenes. •Geogenic furans and hydrogenated halocarbons in air are recalcitrant. -- Anthropogenic and natural VOCs in air are distinguished on the basis of aromatic, O-substituted, S-substituted and halogenated compounds

Locating gamma radiation source by self collimating BGO detector system

Energy Technology Data Exchange (ETDEWEB)

Orion, I; Pernick, A; Ilzycer, D; Zafrir, H [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center; Shani, G [Ben-Gurion Univ. of the Negev, Beersheba (Israel)

1996-12-01

The need for airborne collimated gamma detector system to estimate the radiation released from a nuclear accident has been established. A BGO detector system has been developed as an array of separate seven cylindrical Bismuth Germanate scintillators, one central detector symmetrically surrounded by six detectors. In such an arrangement, each of the detectors reduced the exposure of other detectors in the array to a radiation incident from a possible specific spatial angle, around file array. This shielding property defined as `self-collimation`, differs the point source response function for each of the detectors. The BGO detector system has a high density and atomic number, and therefore provides efficient self-collimation. Using the response functions of the separate detectors enables locating point sources as well as the direction of a nuclear radioactive plume with satisfactory angular resolution, of about 10 degrees. The detector`s point source response, as function of the source direction, in a horizontal plane, has been predicted by analytical calculation, and was verified by Monte-Carlo simulation using the code EGS4. The detector`s response was tested in a laboratory-scale experiment for several gamma ray energies, and the experimental results validated the theoretical (analytical and Monte-Carlo) results. (authors).

Optimal source coding, removable noise elimination, and natural coordinate system construction for general vector sources using replicator neural networks

Science.gov (United States)

Hecht-Nielsen, Robert

1997-04-01

A new universal one-chart smooth manifold model for vector information sources is introduced. Natural coordinates (a particular type of chart) for such data manifolds are then defined. Uniformly quantized natural coordinates form an optimal vector quantization code for a general vector source. Replicator neural networks (a specialized type of multilayer perceptron with three hidden layers) are the introduced. As properly configured examples of replicator networks approach minimum mean squared error (e.g., via training and architecture adjustment using randomly chosen vectors from the source), these networks automatically develop a mapping which, in the limit, produces natural coordinates for arbitrary source vectors. The new concept of removable noise (a noise model applicable to a wide variety of real-world noise processes) is then discussed. Replicator neural networks, when configured to approach minimum mean squared reconstruction error (e.g., via training and architecture adjustment on randomly chosen examples from a vector source, each with randomly chosen additive removable noise contamination), in the limit eliminate removable noise and produce natural coordinates for the data vector portions of the noise-corrupted source vectors. Consideration regarding selection of the dimension of a data manifold source model and the training/configuration of replicator neural networks are discussed.

On the Nature of Orion Source I

Science.gov (United States)

Báez-Rubio, A.; Jiménez-Serra, I.; Martín-Pintado, J.; Zhang, Q.; Curiel, S.

2018-01-01

The Kleinmann–Low nebula in Orion, the closest region of massive star formation, harbors Source I, whose nature is under debate. Knowledge of this source may have profound implications for our understanding of the energetics of the hot core in Orion KL since it might be the main heating source in the region. The spectral energy distribution of this source in the radio is characterized by a positive spectral index close to 2, which is consistent with (i) thermal bremsstrahlung emission of ionized hydrogen gas produced by a central massive protostar, or (ii) photospheric bremsstrahlung emission produced by electrons when deflected by the interaction with neutral and molecular hydrogen like Mira-like variable stars. If ionized hydrogen gas were responsible for the observed continuum emission, its modeling would predict detectable emission from hydrogen radio recombination lines (RRLs). However, our SMA observations were obtained with a high enough sensitivity to rule out that the radio continuum emission arises from a dense hypercompact H II region because the H26α line would have been detected, in contrast with our observations. To explain the observational constraints, we investigate further the nature of the radio continuum emission from source I. We have compared available radio continuum data with the predictions from our upgraded non-LTE 3D radiative transfer model, MOdel for REcombination LInes, to show that radio continuum fluxes and sizes can only be reproduced by assuming both dust and bremsstrahlung emission from neutral gas. The dust emission contribution is significant at ν ≥ 43 GHz. In addition, our RRL peak intensity predictions for the ionized metals case are consistent with the nondetection of Na and K RRLs at millimeter and submillimeter wavelengths.

Application Research of Horn Array Multi-Beam Antenna in Reference Source System for Satellite Interference Location

Science.gov (United States)

Zhou, Ping; Lin, Hui; Zhang, Qi

2018-01-01

The reference source system is a key factor to ensure the successful location of the satellite interference source. Currently, the traditional system used a mechanical rotating antenna which leaded to the disadvantages of slow rotation and high failure-rate, which seriously restricted the system’s positioning-timeliness and became its obvious weaknesses. In this paper, a multi-beam antenna scheme based on the horn array was proposed as a reference source for the satellite interference location, which was used as an alternative to the traditional reference source antenna. The new scheme has designed a small circularly polarized horn antenna as an element and proposed a multi-beamforming algorithm based on planar array. Moreover, the simulation analysis of horn antenna pattern, multi-beam forming algorithm and simulated satellite link cross-ambiguity calculation have been carried out respectively. Finally, cross-ambiguity calculation of the traditional reference source system has also been tested. The comparison between the results of computer simulation and the actual test results shows that the scheme is scientific and feasible, obviously superior to the traditional reference source system.

Characteristics of Love and Rayleigh waves in ambient noise: wavetype ratio, source location and seasonal behavior

Science.gov (United States)

Juretzek, C.; Perleth, M.; Hadziioannou, C.

2015-12-01

Ambient seismic noise has become an important source of signal for tomography and monitoring purposes. Better understanding of the noise field characteristics is crucial to further improve noise applications. Our knowledge about the common and different origins of Love and Rayleigh waves in the microseism bands is still limited. This applies in particular to constraints on source locations and source mechanisms of Love waves. Here, 3-component beamforming is used to distinguish between the differently polarized wave types present in the noise field recorded at several arrays across Europe. The focus lies on frequencies around the primary and secondary microseismic bands. We compare characteristics of Love and Rayleigh wave noise, such as source directions and frequency content. Further, Love to Rayleigh wave ratios are measured at each array, and a dependence on direction is observed. We constrain the corresponding source regions of both wave types by backprojection. By using a full year of data in 2013, we are able to track the seasonal changes in our observations of Love-to-Rayleigh ratio and source locations.

A hybrid algorithm for stochastic single-source capacitated facility location problem with service level requirements

Directory of Open Access Journals (Sweden)

Hosseinali Salemi

2016-04-01

Full Text Available Facility location models are observed in many diverse areas such as communication networks, transportation, and distribution systems planning. They play significant role in supply chain and operations management and are one of the main well-known topics in strategic agenda of contemporary manufacturing and service companies accompanied by long-lasting effects. We define a new approach for solving stochastic single source capacitated facility location problem (SSSCFLP. Customers with stochastic demand are assigned to set of capacitated facilities that are selected to serve them. It is demonstrated that problem can be transformed to deterministic Single Source Capacitated Facility Location Problem (SSCFLP for Poisson demand distribution. A hybrid algorithm which combines Lagrangian heuristic with adjusted mixture of Ant colony and Genetic optimization is proposed to find lower and upper bounds for this problem. Computational results of various instances with distinct properties indicate that proposed solving approach is efficient.

Comparison of hydrocarbon gases in soils from natural seeps and anthropogenic sources

International Nuclear Information System (INIS)

Ririe, G.T.; Sweeney, R.E.

1993-01-01

Soil gas geochemical data are commonly used in site assessments to determine the nature and extent of soil contamination. There are also a number of sites where soil gas data can be used to infer the nature and approximate extent of free product or high concentration of dissolved contaminant in ground waters. The authors have conducted a variety of soil gas investigations in support of UNOCAL's site assessment and remediation efforts that have included studies on abandoned oil fields. Because many of these abandoned oil field sites will be used for residential development it is necessary to distinguish the type of soil gas data that are to be expected from natural sources from those derived from subsurface contamination. Data have been collected from a number of active and abandoned oil fields where a variety of subsurface contaminants including spilled crude oil, condensate, and solvents have been found. In several of these sites the authors have found evidence for both natural sources of soil gas anomalies, and anomalies associated with anthropogenic sources/causes. The distinction becomes particularly important when remedial options are being evaluated because it is impossible to remediate most natural sources

Location On Natural Valuable Areas As A Condition For The Development Of Enterprises Based On The Use Of Natural Resources – The Lublin Voivodeship (Poland

Directory of Open Access Journals (Sweden)

Zwolińska-Ligaj Magdalena

2015-05-01

Full Text Available The aim of the study is to identify opportunities and constraints of the development of companies whose business is based on the exploitation of natural resources resulting from their location in areas of natural value. The study area consisted of 40 municipalities. Five companies were selected for the study in each municipality. The study used the method of diagnostic survey using a questionnaire interview. The results obtained give rise to a finding that economic activity based on the use of local natural resources, taking into account the need to protect the natural environment, is a legitimate direction and an opportunity for the development of local economies of areas of natural value. However, given the limitations of economic activities in natural valuable areas, it requires support, mainly with information and finance. The most important limitations of economic activities in natural valuable areas include the lack of preferential financial instruments, difficulties of the investment process and the lack of financial compensation for profits lost due to the location.

Radiological Protection Experience with natural sources of radiation

International Nuclear Information System (INIS)

Quindos, L. S.; Fernandez, P. L.; Vinuela, J.; Arteche, J.; Sainz, G.; Gomez, J.; Matarranz

2003-01-01

During the last twenty five years the research Radon Group of the Medical Physics Unit of the University of Cantabria has been involved in projects concerning the measurement of natural radiation, in special that coming from radon gas. At this moment we have available for this field a lot of information in different formats, as paper, video and CD, interesting not only for public in general but also for professionals interested in the evaluation of doses coming from natural sources of radiation. (Author)

Neural network AE source location apart from structure size and material

Czech Academy of Sciences Publication Activity Database

Chlada, Milan; Převorovský, Zdeněk; Blaháček, Michal

2010-01-01

Roč. 28, - (2010), s. 99-107 ISSN 0730-0050. [European Conference on Acoustic Emission Testing 2010 /29./. Vídeň, 08.09.2010-10.09.2010] R&D Projects: GA ČR(CZ) GAP104/10/1430; GA MPO(CZ) FR-TI1/274 Institutional research plan: CEZ:AV0Z20760514 Keywords : AE source location * artificial neural network * arrival time profiles Subject RIV: BI - Acoustics http://www.ndt.net/search/abstract.php3?AbsID=10828

Carotenoids located in human lymphocyte subpopulations and Natural Killer cells by Raman microspectroscopy

NARCIS (Netherlands)

Puppels, G.J.; Puppels, G.J.; Garritsen, H.S.P.; Garritsen, H.S.P.; Kummer, J.A.; Greve, Jan

1993-01-01

The presence and subcellular location of carotenoids in human lymphocyte sub-populations (CD4+, CD8+, T-cell receptor-γδ+, and CD19+ ) and natural killer cells (CD16+ ) were studied by means of Raman microspectroscopy. In CD4+ lymphocytes a high concentration (10-3M) of carotenoids was found in the

Solving seismological problems using SGRAPH program: I-source parameters and hypocentral location

International Nuclear Information System (INIS)

Abdelwahed, Mohamed F.

2012-01-01

SGRAPH program is considered one of the seismological programs that maintain seismic data. SGRAPH is considered unique for being able to read a wide range of data formats and manipulate complementary tools in different seismological subjects in a stand-alone Windows-based application. SGRAPH efficiently performs the basic waveform analysis and solves advanced seismological problems. The graphical user interface (GUI) utilities and the Windows facilities such as, dialog boxes, menus, and toolbars simplified the user interaction with data. SGRAPH supported the common data formats like, SAC, SEED, GSE, ASCII, and Nanometrics Y-format, and others. It provides the facilities to solve many seismological problems with the built-in inversion and modeling tools. In this paper, I discuss some of the inversion tools built-in SGRAPH related to source parameters and hypocentral location estimation. Firstly, a description of the SGRAPH program is given discussing some of its features. Secondly, the inversion tools are applied to some selected events of the Dahshour earthquakes as an example of estimating the spectral and source parameters of local earthquakes. In addition, the hypocentral location of these events are estimated using the Hypoinverse 2000 program operated by SGRAPH.

Rapidly locating sources and predicting contaminant dispersion in buildings

International Nuclear Information System (INIS)

Sohn, Michael D.; Reynolds, Pamela; Gadgil, Ashok J.; Sextro, Richard G.

2002-01-01

Contaminant releases in or near a building can lead to significant human exposures unless prompt response measures are taken. However, selecting the proper response depends in part on knowing the source locations, the amounts released, and the dispersion characteristics of the pollutants. We present an approach that estimates this information in real time. It uses Bayesian statistics to interpret measurements from sensors placed in the building yielding best estimates and uncertainties for the release conditions, including the operating state of the building. Because the method is fast, it continuously updates the estimates as measurements stream in from the sensors. We show preliminary results for characterizing a gas release in a three-floor, multi-room building at the Dugway Proving Grounds, Utah, USA

Natural radionuclides in the UK marine environment

Energy Technology Data Exchange (ETDEWEB)

Rollo, S F.N.; Camplin, W C; Allington, D J; Young, A K [Ministry of Agriculture, Fisheries and Food, Lowestoft (United Kingdom). Fisheries Radiobiological Lab.

1992-01-01

The importance of natural radionuclides giving rise to radiation exposure of man from marine consumption pathways has been known for some time. However, the extent of surveys of levels in marine biota has been limited. This paper presents new data on concentrations of natural radionuclides in fish, shellfish and seaweeds taken from coastal sampling locations in the U.K. Sampling included areas where levels due to natural sources would be predominant, but efforts were made to study potential sources of technologically enhanced discharges to seas and rivers, particularly the phosphogypsum plant at Whitehaven in Cumbria. The highest concentrations (up to 371 Bq.kg[sup -1] (wet) [sup 210]Po) were observed in winkles near Whitehaven. The general levels at sites remote from known sources were much lower. Monthly concentrations in molluscs at a single location were elevated by approximately a factor of 2 during the summer months. An assessment of the expected doses to members of the public from marine consumption pathways is made. (author).

Accurate source location from waves scattered by surface topography: Applications to the Nevada and North Korean test sites

Science.gov (United States)

Shen, Y.; Wang, N.; Bao, X.; Flinders, A. F.

2016-12-01

Scattered waves generated near the source contains energy converted from the near-field waves to the far-field propagating waves, which can be used to achieve location accuracy beyond the diffraction limit. In this work, we apply a novel full-wave location method that combines a grid-search algorithm with the 3D Green's tensor database to locate the Non-Proliferation Experiment (NPE) at the Nevada test site and the North Korean nuclear tests. We use the first arrivals (Pn/Pg) and their immediate codas, which are likely dominated by waves scattered at the surface topography near the source, to determine the source location. We investigate seismograms in the frequency of [1.0 2.0] Hz to reduce noises in the data and highlight topography scattered waves. High resolution topographic models constructed from 10 and 90 m grids are used for Nevada and North Korea, respectively. The reference velocity model is based on CRUST 1.0. We use the collocated-grid finite difference method on curvilinear grids to calculate the strain Green's tensor and obtain synthetic waveforms using source-receiver reciprocity. The `best' solution is found based on the least-square misfit between the observed and synthetic waveforms. To suppress random noises, an optimal weighting method for three-component seismograms is applied in misfit calculation. Our results show that the scattered waves are crucial in improving resolution and allow us to obtain accurate solutions with a small number of stations. Since the scattered waves depends on topography, which is known at the wavelengths of regional seismic waves, our approach yields absolute, instead of relative, source locations. We compare our solutions with those of USGS and other studies. Moreover, we use differential waveforms to locate pairs of the North Korea tests from years 2006, 2009, 2013 and 2016 to further reduce the effects of unmodeled heterogeneities and errors in the reference velocity model.

Crowd-Sourced Mobility Mapping for Location Tracking Using Unlabeled Wi-Fi Simultaneous Localization and Mapping

Directory of Open Access Journals (Sweden)

Mu Zhou

2015-01-01

Full Text Available Due to the increasing requirements of the seamless and round-the-clock Location-based services (LBSs, a growing interest in Wi-Fi network aided location tracking is witnessed in the past decade. One of the significant problems of the conventional Wi-Fi location tracking approaches based on received signal strength (RSS fingerprinting is the time-consuming and labor intensive work involved in location fingerprint calibration. To solve this problem, a novel unlabeled Wi-Fi simultaneous localization and mapping (SLAM approach is developed to avoid the location fingerprinting and additional inertial or vision sensors. In this approach, an unlabeled mobility map of the coverage area is first constructed by using the crowd-sourcing from a batch of sporadically recorded Wi-Fi RSS sequences based on the spectral cluster assembling. Then, the sequence alignment algorithm is applied to conduct location tracking and mobility map updating. Finally, the effectiveness of this approach is verified by the extensive experiments carried out in a campus-wide area.

Lattice location of gold in natural pyrite crystals

International Nuclear Information System (INIS)

Besten, Jacinta den; Jamieson, David N.; Ryan, Chris G.

1999-01-01

The lattice location of gold atoms in naturally occurring Au-doped pyrite crystals has been investigated with a nuclear microprobe using ion channeling. The specimens consisted of 300-μm diameter pyrite crystals in veins embedded in a quartz matrix from the Emperor mine in Fiji. The specimens were prepared by standard geological specimen preparation techniques and the pyrite crystals were analysed in situ in the quartz matrix. Significant trace elements in the crystals, determined by Proton Induced X-ray Emission with a 3 MeV H + microprobe, were Cu, As, Mo, Zn, Te, Au and Pb. The Au concentration was about 0.2 wt%. By the use of 2 MeV He + ion channeling, the Miller indices of the lowest order crystal axes nearest to the normal were determined from backscattering yield maps from two-dimensional angular scanning and comparison of the resulting patterns with published gnomonic projections. Channeling angular yield curves were obtained from Fe, S, As and Au signals. The results indicate that at least 35% of the Au is substituted onto lattice sites

Community Assessment of Natural Food Sources of Vitamin A ...

International Development Research Centre (IDRC) Digital Library (Canada)

1997-01-01

Jan 1, 1997 ... This manual presents a practical step-by-step guide for assessing various aspects of natural food sources of vitamin A within a community and is essential for any research program involved in alleviating vitamin A deficiency.

Guidance of Attention to Objects and Locations by Long-Term Memory of Natural Scenes

Science.gov (United States)

Becker, Mark W.; Rasmussen, Ian P.

2008-01-01

Four flicker change-detection experiments demonstrate that scene-specific long-term memory guides attention to both behaviorally relevant locations and objects within a familiar scene. Participants performed an initial block of change-detection trials, detecting the addition of an object to a natural scene. After a 30-min delay, participants…

The use of permit markets for incorporating source location. The case of acid rain in Europe

International Nuclear Information System (INIS)

Steiner, U.; Tinggaard Svendsen, G.

1997-01-01

The paper shows that cost-effective involvement of the source location involves utmost difficulty in practice. Based on the RAINS model, it is recommended that source location should be ignored in a European market for SO 2 , as is the case in the US Acid Rain Program. The RAINS-model predicts a cost-saving of 37 percent but an average loss of 2 percent in ecological protection. To overcome this reduction in protection, we recommend that some of the large cost-savings should be reallocated in further overall reduction and that the countries suffering the most from introducing the permit-market should be compensated by receiving extra permits in the initial distribution. (au)

Locating sensors for detecting source-to-target patterns of special nuclear material smuggling: a spatial information theoretic approach.

Science.gov (United States)

Przybyla, Jay; Taylor, Jeffrey; Zhou, Xuesong

2010-01-01

In this paper, a spatial information-theoretic model is proposed to locate sensors for detecting source-to-target patterns of special nuclear material (SNM) smuggling. In order to ship the nuclear materials from a source location with SNM production to a target city, the smugglers must employ global and domestic logistics systems. This paper focuses on locating a limited set of fixed and mobile radiation sensors in a transportation network, with the intent to maximize the expected information gain and minimize the estimation error for the subsequent nuclear material detection stage. A Kalman filtering-based framework is adapted to assist the decision-maker in quantifying the network-wide information gain and SNM flow estimation accuracy.

Locating Sensors for Detecting Source-to-Target Patterns of Special Nuclear Material Smuggling: A Spatial Information Theoretic Approach

Directory of Open Access Journals (Sweden)

Xuesong Zhou

2010-08-01

Full Text Available In this paper, a spatial information-theoretic model is proposed to locate sensors for detecting source-to-target patterns of special nuclear material (SNM smuggling. In order to ship the nuclear materials from a source location with SNM production to a target city, the smugglers must employ global and domestic logistics systems. This paper focuses on locating a limited set of fixed and mobile radiation sensors in a transportation network, with the intent to maximize the expected information gain and minimize the estimation error for the subsequent nuclear material detection stage. A Kalman filtering-based framework is adapted to assist the decision-maker in quantifying the network-wide information gain and SNM flow estimation accuracy.

Reconstruction of source location in a network of gravitational wave interferometric detectors

International Nuclear Information System (INIS)

Cavalier, Fabien; Barsuglia, Matteo; Bizouard, Marie-Anne; Brisson, Violette; Clapson, Andre-Claude; Davier, Michel; Hello, Patrice; Kreckelbergh, Stephane; Leroy, Nicolas; Varvella, Monica

2006-01-01

This paper deals with the reconstruction of the direction of a gravitational wave source using the detection made by a network of interferometric detectors, mainly the LIGO and Virgo detectors. We suppose that an event has been seen in coincidence using a filter applied on the three detector data streams. Using the arrival time (and its associated error) of the gravitational signal in each detector, the direction of the source in the sky is computed using a χ 2 minimization technique. For reasonably large signals (SNR>4.5 in all detectors), the mean angular error between the real location and the reconstructed one is about 1 deg. . We also investigate the effect of the network geometry assuming the same angular response for all interferometric detectors. It appears that the reconstruction quality is not uniform over the sky and is degraded when the source approaches the plane defined by the three detectors. Adding at least one other detector to the LIGO-Virgo network reduces the blind regions and in the case of 6 detectors, a precision less than 1 deg. on the source direction can be reached for 99% of the sky

Bayesian inverse modeling and source location of an unintended 131I release in Europe in the fall of 2011

Science.gov (United States)

Tichý, Ondřej; Šmídl, Václav; Hofman, Radek; Šindelářová, Kateřina; Hýža, Miroslav; Stohl, Andreas

2017-10-01

In the fall of 2011, iodine-131 (131I) was detected at several radionuclide monitoring stations in central Europe. After investigation, the International Atomic Energy Agency (IAEA) was informed by Hungarian authorities that 131I was released from the Institute of Isotopes Ltd. in Budapest, Hungary. It was reported that a total activity of 342 GBq of 131I was emitted between 8 September and 16 November 2011. In this study, we use the ambient concentration measurements of 131I to determine the location of the release as well as its magnitude and temporal variation. As the location of the release and an estimate of the source strength became eventually known, this accident represents a realistic test case for inversion models. For our source reconstruction, we use no prior knowledge. Instead, we estimate the source location and emission variation using only the available 131I measurements. Subsequently, we use the partial information about the source term available from the Hungarian authorities for validation of our results. For the source determination, we first perform backward runs of atmospheric transport models and obtain source-receptor sensitivity (SRS) matrices for each grid cell of our study domain. We use two dispersion models, FLEXPART and Hysplit, driven with meteorological analysis data from the global forecast system (GFS) and from European Centre for Medium-range Weather Forecasts (ECMWF) weather forecast models. Second, we use a recently developed inverse method, least-squares with adaptive prior covariance (LS-APC), to determine the 131I emissions and their temporal variation from the measurements and computed SRS matrices. For each grid cell of our simulation domain, we evaluate the probability that the release was generated in that cell using Bayesian model selection. The model selection procedure also provides information about the most suitable dispersion model for the source term reconstruction. Third, we select the most probable location of

Bayesian inverse modeling and source location of an unintended 131I release in Europe in the fall of 2011

Directory of Open Access Journals (Sweden)

O. Tichý

2017-10-01

Full Text Available In the fall of 2011, iodine-131 (131I was detected at several radionuclide monitoring stations in central Europe. After investigation, the International Atomic Energy Agency (IAEA was informed by Hungarian authorities that 131I was released from the Institute of Isotopes Ltd. in Budapest, Hungary. It was reported that a total activity of 342 GBq of 131I was emitted between 8 September and 16 November 2011. In this study, we use the ambient concentration measurements of 131I to determine the location of the release as well as its magnitude and temporal variation. As the location of the release and an estimate of the source strength became eventually known, this accident represents a realistic test case for inversion models. For our source reconstruction, we use no prior knowledge. Instead, we estimate the source location and emission variation using only the available 131I measurements. Subsequently, we use the partial information about the source term available from the Hungarian authorities for validation of our results. For the source determination, we first perform backward runs of atmospheric transport models and obtain source-receptor sensitivity (SRS matrices for each grid cell of our study domain. We use two dispersion models, FLEXPART and Hysplit, driven with meteorological analysis data from the global forecast system (GFS and from European Centre for Medium-range Weather Forecasts (ECMWF weather forecast models. Second, we use a recently developed inverse method, least-squares with adaptive prior covariance (LS-APC, to determine the 131I emissions and their temporal variation from the measurements and computed SRS matrices. For each grid cell of our simulation domain, we evaluate the probability that the release was generated in that cell using Bayesian model selection. The model selection procedure also provides information about the most suitable dispersion model for the source term reconstruction. Third, we select the most

2nd Workshop on the Nature of the High-Energy Unidentified Sources

CERN Document Server

Cheng, K S; Multiwavelength Approach to Unidentified Gamma-Ray Sources

2005-01-01

Nearly one half of the point-like gamma-ray sources detected by EGRET instrument of the late Compton satellite are still defeating our attempts at identifying them. To establish the origin and nature of these enigmatic sources has become a major problem of current high-energy astrophysics. The second workshop on Multiwavelength Approach to Unidentified Gamma-ray Sources intends to shed new and fresh light on the problem of the nature of these mysterious sources and the objects behind them. The proceedings contain 46 contributed papers in this subject, which cover theoretical models on gamma-ray sources as well as the best multiwavelength strategies for the identification of the promising candidates. The topics of this conference also include energetic phenomena ocurring both in galactic and extragalactic scenarios, phenomena that might lead to the appearance of what we have called high-energy unidentified sources. The book will be of interest for all active researchers in the high-energy astrophysics and rela...

Nature and location of quantum information

International Nuclear Information System (INIS)

Griffiths, Robert B.

2002-01-01

Quantum information is defined by applying the concepts of ordinary (Shannon) information theory to a quantum sample space consisting of a single framework or consistent family. A classical analogy for a spin-half particle and other arguments show that the infinite amount of information needed to specify a precise vector in its Hilbert space is not a measure of the information carried by a quantum entity with a d-dimensional Hilbert space; the latter is, instead, bounded by log 2 d bits (one bit per qubit). The two bits of information transmitted in dense coding are located not in one but in the correlation between two qubits, consistent with this bound. A quantum channel can be thought of as a structure or collection of frameworks, and the physical location of the information in the individual frameworks can be used to identify the location of the channel. Analysis of a quantum circuit used as a model of teleportation shows that the location of the channel depends upon which structure is employed; for ordinary teleportation it is not (contrary to Deutsch and Hayden) present in the two bits resulting from the Bell-basis measurement, but in correlations of these with a distant qubit. In neither teleportation nor dense coding does information travel backwards in time, nor is it transmitted by nonlocal (superluminal) influences. It is (tentatively) proposed that all aspects of quantum information can in principle be understood in terms of the (basically classical) behavior of information in a particular framework, along with the framework dependence of this information

Task-Modulated Cortical Representations of Natural Sound Source Categories

DEFF Research Database (Denmark)

Hjortkjær, Jens; Kassuba, Tanja; Madsen, Kristoffer Hougaard

2018-01-01

In everyday sound environments, we recognize sound sources and events by attending to relevant aspects of an acoustic input. Evidence about the cortical mechanisms involved in extracting relevant category information from natural sounds is, however, limited to speech. Here, we used functional MRI...

Benzene observations and source appointment in a region of oil and natural gas development

Science.gov (United States)

Halliday, Hannah Selene

were identified in the PMF analysis: a primarily CO source, an aged vehicle emissions source, a diesel/compressed natural gas emissions source, a fugitive emissions source, and two sources that have the characteristics of a mix of fresh vehicle emissions and condensate fugitive emissions. 70% of the benzene measured at PAO on the PTR-QMS is attributed to fugitive emissions, primarily located to the SW of PAO. Comparing the PMF source attribution to source calculations done with a source array configured from the literature returns a contradictory result, with the expected sources indicting that aged vehicle emissions are the primary benzene source. However, analysis of the contradictory result indicates that the toluene to benzene ratio measured for PAO is much lower than the literature values, suggesting that the O&NG source emissions have a lower ratio of toluene to benzene than anticipated based on studies of other regions. Finally, we propose and investigate an alternative form of the source receptor model using a constrained optimization. Poor results of the proposed method are described with tests on a synthetic testing dataset, and further testing with the observation data from PAO indicate that the proposed method is not able to converge the best global solution to the system.

Source Apportionment of Particle Bound Polycyclic Aromatic Hydrocarbons at an Industrial Location in Agra, India

Directory of Open Access Journals (Sweden)

Anita Lakhani

2012-01-01

Full Text Available 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs were quantified in total suspended ambient particulate matter (TSPM collected from an industrial site in Agra (India using gas chromatography. The major industrial activities in Agra are foundries that previously used coal and coke as fuel in cupola furnaces. These foundries have now switched over to natural gas. In addition, use of compressed natural gas has also been promoted and encouraged in automobiles. This study attempts to apportion sources of PAH in the ambient air and the results reflect the advantages associated with the change of fuel. The predominant PAHs in TSPM include high molecular weight (HMW congeners BghiP, DbA, IP, and BaP. The sum of 16 priority PAHs had a mean value of 72.7 ± 4.7 ng m−3. Potential sources of PAHs in aerosols were identified using diagnostic ratios and principal component analysis. The results reflect a blend of emissions from diesel and natural gas as the major sources of PAH in the city along with contribution from emission of coal, coke, and gasoline.

Measurement of acoustic characteristics of Japanese Buddhist temples in relation to sound source location and direction.

Science.gov (United States)

Soeta, Yoshiharu; Shimokura, Ryota; Kim, Yong Hee; Ohsawa, Tomohiro; Ito, Ken

2013-05-01

Although temples are important buildings in the Buddhist community, the acoustic quality has not been examined in detail. Buddhist monks change the location and direction according to the ceremony, and associated acoustical changes have not yet been examined scientifically. To discuss the desired acoustics of temples, it is necessary to know the acoustic characteristics appropriate for each phase of a ceremony. In this study, acoustic measurements were taken at various source locations and directions in Japanese temples. A directional loudspeaker was used as the source to provide vocal acoustic fields, and impulse responses were measured and analyzed. The speech transmission index was higher and the interaural cross-correlation coefficient was lower for the sound source directed toward the side wall than that directed toward the altar. This suggests that the change in direction improves speech intelligibility, and the asymmetric property of direct sound and complex reflections from the altar and side wall increases the apparent source width. The large and coupled-like structure of the altar of a Buddhist temple may have reinforced the reverberation components and the table in the altar, which is called the "syumidan," may have decreased binaural coherence.

Marine actinobacteria: an important source of bioactive natural products.

Science.gov (United States)

Manivasagan, Panchanathan; Kang, Kyong-Hwa; Sivakumar, Kannan; Li-Chan, Eunice C Y; Oh, Hyun-Myung; Kim, Se-Kwon

2014-07-01

Marine environment is largely an untapped source for deriving actinobacteria, having potential to produce novel, bioactive natural products. Actinobacteria are the prolific producers of pharmaceutically active secondary metabolites, accounting for about 70% of the naturally derived compounds that are currently in clinical use. Among the various actinobacterial genera, Actinomadura, Actinoplanes, Amycolatopsis, Marinispora, Micromonospora, Nocardiopsis, Saccharopolyspora, Salinispora, Streptomyces and Verrucosispora are the major potential producers of commercially important bioactive natural products. In this respect, Streptomyces ranks first with a large number of bioactive natural products. Marine actinobacteria are unique enhancing quite different biological properties including antimicrobial, anticancer, antiviral, insecticidal and enzyme inhibitory activities. They have attracted global in the last ten years for their ability to produce pharmaceutically active compounds. In this review, we have focused attention on the bioactive natural products isolated from marine actinobacteria, possessing unique chemical structures that may form the basis for synthesis of novel drugs that could be used to combat resistant pathogenic microorganisms. Copyright © 2014 Elsevier B.V. All rights reserved.

Decision making algorithms for hydro-power plant location

CERN Document Server

Majumder, Mrinmoy

2013-01-01

The present study has attempted to apply the advantage of neuro-genetic algorithms for optimal decision making in maximum utilization of natural resources. Hydro-power is one of the inexpensive, but a reliable source of alternative energy which is foreseen as the possible answer to the present crisis in the energy sector. However, the major problem related to hydro-energy is its dependency on location. An ideal location can produce maximum energy with minimum loss. Besides, such power-plant also requires substantial amount of land which is a precious resource nowadays due to the rapid and unco

Integrating cut-and-solve and semi-Lagrangean based dual ascent for the single-source capacitated facility location problem

DEFF Research Database (Denmark)

Gadegaard, Sune Lauth

polytope with generalized upper bounds. From our computational study, we show that the semi-Lagrangean relaxation approach has its merits when the instances are tightly constrained with regards to the capacity of the system, but that it is very hard to compete with a standalone implementation of the cut......This paper describes how the cut-and-solve framework and semi-Lagrangean based dual ascent algorithms can be integrated in two natural ways in order to solve the single source capacitated facility location problem. The first uses the cut-and-solve framework both as a heuristic and as an exact...... solver for the semi-Lagrangean subproblems. The other uses a semi-Lagrangean based dual ascent algorithm to solve the sparse problems arising in the cut-and-solve algorithm. Furthermore, we developed a simple way to separate a special type of cutting planes from what we denote the effective capacity...

Artificial intelligence methods applied for quantitative analysis of natural radioactive sources

International Nuclear Information System (INIS)

Medhat, M.E.

2012-01-01

Highlights: ► Basic description of artificial neural networks. ► Natural gamma ray sources and problem of detections. ► Application of neural network for peak detection and activity determination. - Abstract: Artificial neural network (ANN) represents one of artificial intelligence methods in the field of modeling and uncertainty in different applications. The objective of the proposed work was focused to apply ANN to identify isotopes and to predict uncertainties of their activities of some natural radioactive sources. The method was tested for analyzing gamma-ray spectra emitted from natural radionuclides in soil samples detected by a high-resolution gamma-ray spectrometry based on HPGe (high purity germanium). The principle of the suggested method is described, including, relevant input parameters definition, input data scaling and networks training. It is clear that there is satisfactory agreement between obtained and predicted results using neural network.

Acoustic emission source location in plates using wavelet analysis and cross time frequency spectrum.

Science.gov (United States)

Mostafapour, A; Davoodi, S; Ghareaghaji, M

2014-12-01

In this study, the theories of wavelet transform and cross-time frequency spectrum (CTFS) are used to locate AE source with frequency-varying wave velocity in plate-type structures. A rectangular array of four sensors is installed on the plate. When an impact is generated by an artificial AE source such as Hsu-Nielsen method of pencil lead breaking (PLB) at any position of the plate, the AE signals will be detected by four sensors at different times. By wavelet packet decomposition, a packet of signals with frequency range of 0.125-0.25MHz is selected. The CTFS is calculated by the short-time Fourier transform of the cross-correlation between considered packets captured by AE sensors. The time delay is calculated when the CTFS reaches the maximum value and the corresponding frequency is extracted per this maximum value. The resulting frequency is used to calculate the group velocity of wave velocity in combination with dispersive curve. The resulted locating error shows the high precision of proposed algorithm. Copyright © 2014 Elsevier B.V. All rights reserved.

Observational constraints on the physical nature of submillimetre source multiplicity: chance projections are common

Science.gov (United States)

Hayward, Christopher C.; Chapman, Scott C.; Steidel, Charles C.; Golob, Anneya; Casey, Caitlin M.; Smith, Daniel J. B.; Zitrin, Adi; Blain, Andrew W.; Bremer, Malcolm N.; Chen, Chian-Chou; Coppin, Kristen E. K.; Farrah, Duncan; Ibar, Eduardo; Michałowski, Michał J.; Sawicki, Marcin; Scott, Douglas; van der Werf, Paul; Fazio, Giovanni G.; Geach, James E.; Gurwell, Mark; Petitpas, Glen; Wilner, David J.

2018-05-01

Interferometric observations have demonstrated that a significant fraction of single-dish submillimetre (submm) sources are blends of multiple submm galaxies (SMGs), but the nature of this multiplicity, i.e. whether the galaxies are physically associated or chance projections, has not been determined. We performed spectroscopy of 11 SMGs in six multicomponent submm sources, obtaining spectroscopic redshifts for nine of them. For an additional two component SMGs, we detected continuum emission but no obvious features. We supplement our observed sources with four single-dish submm sources from the literature. This sample allows us to statistically constrain the physical nature of single-dish submm source multiplicity for the first time. In three (3/7, { or} 43^{+39 }_{ -33} {per cent at 95 {per cent} confidence}) of the single-dish sources for which the nature of the blending is unambiguous, the components for which spectroscopic redshifts are available are physically associated, whereas 4/7 (57^{+33 }_{ -39} per cent) have at least one unassociated component. When components whose spectra exhibit continuum but no features and for which the photometric redshift is significantly different from the spectroscopic redshift of the other component are also considered, 6/9 (67^{+26 }_{ -37} per cent) of the single-dish sources are comprised of at least one unassociated component SMG. The nature of the multiplicity of one single-dish source is ambiguous. We conclude that physically associated systems and chance projections both contribute to the multicomponent single-dish submm source population. This result contradicts the conventional wisdom that bright submm sources are solely a result of merger-induced starbursts, as blending of unassociated galaxies is also important.

Locating People Diagnosed With HIV for Public Health Action: Utility of HIV Case Surveillance and Other Data Sources.

Science.gov (United States)

Padilla, Mabel; Mattson, Christine L; Scheer, Susan; Udeagu, Chi-Chi N; Buskin, Susan E; Hughes, Alison J; Jaenicke, Thomas; Wohl, Amy Rock; Prejean, Joseph; Wei, Stanley C

Human immunodeficiency virus (HIV) case surveillance and other health care databases are increasingly being used for public health action, which has the potential to optimize the health outcomes of people living with HIV (PLWH). However, often PLWH cannot be located based on the contact information available in these data sources. We assessed the accuracy of contact information for PLWH in HIV case surveillance and additional data sources and whether time since diagnosis was associated with accurate contact information in HIV case surveillance and successful contact. The Case Surveillance-Based Sampling (CSBS) project was a pilot HIV surveillance system that selected a random population-based sample of people diagnosed with HIV from HIV case surveillance registries in 5 state and metropolitan areas. From November 2012 through June 2014, CSBS staff members attempted to locate and interview 1800 sampled people and used 22 data sources to search for contact information. Among 1063 contacted PLWH, HIV case surveillance data provided accurate telephone number, address, or HIV care facility information for 239 (22%), 412 (39%), and 827 (78%) sampled people, respectively. CSBS staff members used additional data sources, such as support services and commercial people-search databases, to locate and contact PLWH with insufficient contact information in HIV case surveillance. PLWH diagnosed surveillance than were PLWH diagnosed ≥1 year ago ( P = .002), and the benefit from using additional data sources was greater for PLWH with more longstanding HIV infection ( P surveillance cannot provide accurate contact information, health departments can prioritize searching additional data sources, especially for people with more longstanding HIV infection.

[Mineral waters from several Brazilian natural sources].

Science.gov (United States)

Rebelo, M A; Araujo, N C

1999-01-01

To divulge information on the chemical composition and physical-chemical features of some mineral waters from Brazilian natural sources that will be of useful protocol investigation and patient advice. The survey was based on bottle labels of non-gaseous mineral waters commercially available in the city of Rio de Janeiro. The íon concentration of each mineral was calculated from the salt content. 36 springs were enralled from different states of the country. The pH (25 degrees C), 4.1 to 9.3, varied on dependence of the source and it was linearey correlated with the cations calcium, magnesium and sodium and the anion bicarbonate. It was atributed to high alkalinity (about 70% of bicarbonate in the molecula-gram) of these salts. The calcium (0.3 to 42 mg/l), magnesium (0.0 to 18 mg/l) and bicarbonate (4 to 228 mg/l) contents are relatively low. The mineral content of the Brazilian springs enrolled in this survey is low; about 70% of the sources having calcium and magnesium less than 10 mg/l and 1.0 mg/l, respectively, similar to local tap water.

Literature: A Natural Source for Teaching English in ESL/ EFL Classrooms

Directory of Open Access Journals (Sweden)

Muhammed Ali Chalikendy

2015-11-01

Full Text Available This paper explores the ways in which literature function as a source and as a meaningful context for teaching and learning English as a second language or foreign language. It claims that literature is an authentic, stimulating and appealing material to the learners. Therefore, it encourages interaction, promotes language development and motivates learners in the process of learning. Traditionally it is taught as an academic subject without considering its potential in ESL/EFL classrooms. The paper argues that literature can be used as an effective source for teaching English language and the target culture; furthermore, it is used as a natural context for integrating language skills and systems. This paper demonstrates how a poem is used as a natural source or a material for developing English language and integrating the four language skills, grammar and vocabulary through communicative tasks and activities.

Contamination with uranium from natural and anthropological sources

International Nuclear Information System (INIS)

Todorov, Peter Todorov; Ilieva, Elica Nikolova

2005-01-01

Our world is radioactive and always was since it was created. Radioactive elements are often called radioactive isotopes or radionuclides. Radionuclides are found in the environment as naturally occurring elements and as products or byproducts of nuclear technologies. One of the most common radionuclides is Uranium (U). U with atomic number of 92 is the heaviest known natural element. All U isotopes are radioactive. So it is very important their quantity to be under control. Natural U is used in the generation of nuclear fuel. U - 235 is one of two fissile materials used for the production of nuclear weapons and in some nuclear reactors as a source of energy. Because of its use in the fission process U is found in large quantities in stored nuclear waste. Other important source of U to the environment was the nuclear weapon tests, especially during the second half of 20th century. Artificial radionuclides may also be released into the environment from non - nuclear cycle activities in industry and research and from usage in diagnostic and therapeutic medicine. Erosion of agricultural soils may input the 238 U decay radionuclides into drinking water supplies in areas with heavy fertilizer usage. The most common routes of U contamination are through handling, ingesting and inhaling. Inhaling and ingesting increase the risk of lung and bone cancer. U is also chemically toxic at high concentrations. U may also affect reproductive organs and the foetus, and may increase the risk of leukemia and soft tissue cancer. (authors)

Source term assessment using inverse modeling of radiation dose measured with environmental radiation monitors located at different positions

International Nuclear Information System (INIS)

Srinivas, C.V.; Rakesh, P.T.; Baskaran, R.; Venkatraman, B.

2018-01-01

Source term is an important input for consequence analysis using Decision Support Systems (DSS) to project radiological impact in the event of nuclear emergencies. A source term model called 'ASTER' is incorporated in the Online Nuclear Emergency Response System (ONERS) operational at Kalpakkam site for decision making during nuclear emergencies. This computes release rates using inverse method by employing an atmospheric dispersion model and gamma dose rates measured by environmental radiation monitors (ERM) deployed around the nuclear plant. The estimates may depend on the distribution of ERMs around the release location. In this work, data from various gamma monitors located at different radii 0.75 km and 1.5 km is used to assess the accuracy in the source term estimation for stack releases of MAPS-PHWR at Kalpakkam

Precise tremor source locations and amplitude variations along the lower-crustal central San Andreas Fault

Science.gov (United States)

Shelly, David R.; Hardebeck, Jeanne L.

2010-01-01

We precisely locate 88 tremor families along the central San Andreas Fault using a 3D velocity model and numerous P and S wave arrival times estimated from seismogram stacks of up to 400 events per tremor family. Maximum tremor amplitudes vary along the fault by at least a factor of 7, with by far the strongest sources along a 25 km section of the fault southeast of Parkfield. We also identify many weaker tremor families, which have largely escaped prior detection. Together, these sources extend 150 km along the fault, beneath creeping, transitional, and locked sections of the upper crustal fault. Depths are mostly between 18 and 28 km, in the lower crust. Epicenters are concentrated within 3 km of the surface trace, implying a nearly vertical fault. A prominent gap in detectible activity is located directly beneath the region of maximum slip in the 2004 magnitude 6.0 Parkfield earthquake.

Long Period (LP) volcanic earthquake source location at Merapi volcano by using dense array technics

Science.gov (United States)

Metaxian, Jean Philippe; Budi Santoso, Agus; Laurin, Antoine; Subandriyo, Subandriyo; Widyoyudo, Wiku; Arshab, Ghofar

2015-04-01

Since 2010, Merapi shows unusual activity compared to last decades. Powerful phreatic explosions are observed; some of them are preceded by LP signals. In the literature, LP seismicity is thought to be originated within the fluid, and therefore to be representative of the pressurization state of the volcano plumbing system. Another model suggests that LP events are caused by slow, quasi-brittle, low stress-drop failure driven by transient upper-edifice deformations. Knowledge of the spatial distribution of LP events is fundamental for better understanding the physical processes occurring in the conduit, as well as for the monitoring and the improvement of eruption forecasting. LP events recorded at Merapi have a spectral content dominated by frequencies between 0.8 and 3 Hz. To locate the source of these events, we installed a seismic antenna composed of 4 broadband CMG-6TD Güralp stations. This network has an aperture of 300 m. It is located on the site of Pasarbubar, between 500 and 800 m from the crater rim. Two multi-parameter stations (seismic, tiltmeter, S-P) located in the same area, equipped with broadband CMG-40T Güralp sensors may also be used to complete the data of the antenna. The source of LP events is located by using different approaches. In the first one, we used a method based on the measurement of the time delays between the early beginnings of LP events for each array receiver. The observed differences of time delays obtained for each pair of receivers are compared to theoretical values calculated from the travel times computed between grid nodes, which are positioned in the structure, and each receiver. In a second approach, we estimate the slowness vector by using MUSIC algorithm applied to 3-components data. From the slowness vector, we deduce the back-azimuth and the incident angle, which give an estimation of LP source depth in the conduit. This work is part of the Domerapi project funded by French Agence Nationale de la Recherche (https

Affective attitudes to face images associated with intracerebral EEG source location before face viewing.

Science.gov (United States)

Pizzagalli, D; Koenig, T; Regard, M; Lehmann, D

1999-01-01

We investigated whether different, personality-related affective attitudes are associated with different brain electric field (EEG) sources before any emotional challenge (stimulus exposure). A 27-channel EEG was recorded in 15 subjects during eyes-closed resting. After recording, subjects rated 32 images of human faces for affective appeal. The subjects in the first (i.e., most negative) and fourth (i.e., most positive) quartile of general affective attitude were further analyzed. The EEG data (mean=25+/-4. 8 s/subject) were subjected to frequency-domain model dipole source analysis (FFT-Dipole-Approximation), resulting in 3-dimensional intracerebral source locations and strengths for the delta-theta, alpha, and beta EEG frequency band, and for the full range (1.5-30 Hz) band. Subjects with negative attitude (compared to those with positive attitude) showed the following source locations: more inferior for all frequency bands, more anterior for the delta-theta band, more posterior and more right for the alpha, beta and 1.5-30 Hz bands. One year later, the subjects were asked to rate the face images again. The rating scores for the same face images were highly correlated for all subjects, and original and retest affective mean attitude was highly correlated across subjects. The present results show that subjects with different affective attitudes to face images had different active, cerebral, neural populations in a task-free condition prior to viewing the images. We conclude that the brain functional state which implements affective attitude towards face images as a personality feature exists without elicitors, as a continuously present, dynamic feature of brain functioning. Copyright 1999 Elsevier Science B.V.

Source Signature of Volatile Organic Compounds (VOCs) associated with oil and natural gas operations in Utah and Colorado

Science.gov (United States)

Gilman, J.; Lerner, B. M.; Warneke, C.; Holloway, J. S.; Peischl, J.; Ryerson, T. B.; Young, C. J.; Edwards, P.; Brown, S. S.; Wolfe, D. E.; Williams, E. J.; De Gouw, J. A.

2012-12-01

The U.S. Energy Information Administration has reported a sharp increase in domestic oil and natural gas production from "unconventional" reserves (e.g., shale and tight sands) between 2005 and 2012. The recent growth in drilling and fossil fuel production has led to environmental concerns regarding local air quality. Severe wintertime ozone events (greater than 100 ppb ozone) have been observed in Utah's Uintah Basin and Wyoming's Upper Green River Basin, both of which contain large natural gas fields. Raw natural gas is a mixture of approximately 60-95 mole percent methane while the remaining fraction is composed of volatile organic compounds (VOCs) and other non-hydrocarbon gases. We measured an extensive set of VOCs and other trace gases near two highly active areas of oil and natural gas production in Utah's Uintah Basin and Colorado's Denver-Julesburg Basin in order to characterize primary emissions of VOCs associated with these industrial operations and identify the key VOCs that are precursors for potential ozone formation. UBWOS (Uintah Basin Winter Ozone Study) was conducted in Uintah County located in northeastern Utah in January-February 2012. Two Colorado studies were conducted at NOAA's Boulder Atmospheric Observatory in Weld County in northeastern Colorado in February-March 2011 and July-August 2012 as part of the NACHTT (Nitrogen, Aerosol Composition, and Halogens on a Tall Tower) and SONNE (Summer Ozone Near Natural gas Emissions) field experiments, respectively. The C2-C6 hydrocarbons were greatly enhanced for all of these studies. For example, the average propane mixing ratio observed during the Utah study was 58 ppb (median = 35 ppb, minimum = 0.8, maximum = 520 ppb propane) compared to urban averages which range between 0.3 and 6.0 ppb propane. We compare the ambient air composition from these studies to urban measurements in order to show that the VOC source signature from oil and natural gas operations is distinct and can be clearly

Isolation and Screening of Lipase Producing Microorganisms from Natural Sources

Czech Academy of Sciences Publication Activity Database

Singh, M. G.; Chandraveer, C.; Tripathi, Abishek

2017-01-01

Roč. 44, č. 1 (2017), s. 19-23 ISSN 0304-5250 Institutional support: RVO:67179843 Keywords : lipase assay * natural sources * screening * submerged fermentation Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7)

Location accuracy evaluation of lightning location systems using natural lightning flashes recorded by a network of high-speed cameras

Science.gov (United States)

Alves, J.; Saraiva, A. C. V.; Campos, L. Z. D. S.; Pinto, O., Jr.; Antunes, L.

2014-12-01

This work presents a method for the evaluation of location accuracy of all Lightning Location System (LLS) in operation in southeastern Brazil, using natural cloud-to-ground (CG) lightning flashes. This can be done through a multiple high-speed cameras network (RAMMER network) installed in the Paraiba Valley region - SP - Brazil. The RAMMER network (Automated Multi-camera Network for Monitoring and Study of Lightning) is composed by four high-speed cameras operating at 2,500 frames per second. Three stationary black-and-white (B&W) cameras were situated in the cities of São José dos Campos and Caçapava. A fourth color camera was mobile (installed in a car), but operated in a fixed location during the observation period, within the city of São José dos Campos. The average distance among cameras was 13 kilometers. Each RAMMER sensor position was determined so that the network can observe the same lightning flash from different angles and all recorded videos were GPS (Global Position System) time stamped, allowing comparisons of events between cameras and the LLS. The RAMMER sensor is basically composed by a computer, a Phantom high-speed camera version 9.1 and a GPS unit. The lightning cases analyzed in the present work were observed by at least two cameras, their position was visually triangulated and the results compared with BrasilDAT network, during the summer seasons of 2011/2012 and 2012/2013. The visual triangulation method is presented in details. The calibration procedure showed an accuracy of 9 meters between the accurate GPS position of the object triangulated and the result from the visual triangulation method. Lightning return stroke positions, estimated with the visual triangulation method, were compared with LLS locations. Differences between solutions were not greater than 1.8 km.

Natural radionuclides in an eucalyptus forest located in the south of Spain

International Nuclear Information System (INIS)

Vaca, F.; Manjon, G.; Garcia-Leon, M.

2001-01-01

Eucalyptus forests can be considered as the main source of raw material for the pulp industry of Spain. This environment was selected for a radioactivity study because natural and artificial radionuclides can be transferred into the pulp mills, associated with raw material, wood and barks, where they are concentrated by industrial processes, becoming a cause of doses. Radionuclide concentration of natural radionuclides ( 238 U, 234 U, 228 Th, 230 Th, 232 Th) were determined by alpha- and gamma-spectrometry. Well-established radiochemical procedures were applied to environmental samples in order to isolate these radionuclides. A comparison between 228 Th activity, determined by gamma-spectrometry, and 232 Th activity, determined by alpha-spectrometry, was used as quality control parameter for analyses. The concentration factors were finally evaluated from experimental data.

Outbreaks source: A new mathematical approach to identify their possible location

Science.gov (United States)

Buscema, Massimo; Grossi, Enzo; Breda, Marco; Jefferson, Tom

2009-11-01

Classical epidemiology has generally relied on the description and explanation of the occurrence of infectious diseases in relation to time occurrence of events rather than to place of occurrence. In recent times, computer generated dot maps have facilitated the modeling of the spread of infectious epidemic diseases either with classical statistics approaches or with artificial “intelligent systems”. Few attempts, however, have been made so far to identify the origin of the epidemic spread rather than its evolution by mathematical topology methods. We report on the use of a new artificial intelligence method (the H-PST Algorithm) and we compare this new technique with other well known algorithms to identify the source of three examples of infectious disease outbreaks derived from literature. The H-PST algorithm is a new system able to project a distances matrix of points (events) into a bi-dimensional space, with the generation of a new point, named hidden unit. This new hidden unit deforms the original Euclidean space and transforms it into a new space (cognitive space). The cost function of this transformation is the minimization of the differences between the original distance matrix among the assigned points and the distance matrix of the same points projected into the bi-dimensional map (or any different set of constraints). For many reasons we will discuss, the position of the hidden unit shows to target the outbreak source in many epidemics much better than the other classic algorithms specifically targeted for this task. Compared with main algorithms known in the location theory, the hidden unit was within yards of the outbreak source in the first example (the 2007 epidemic of Chikungunya fever in Italy). The hidden unit was located in the river between the two village epicentres of the spread exactly where the index case was living. Equally in the second (the 1967 foot and mouth disease epidemic in England), and the third (1854 London Cholera epidemic

Anthropogenic nutrient sources rival natural sources on small scales in the coastal waters of the Southern California Bight

KAUST Repository

Howard, Meredith D. A.; Sutula, Martha; Caron, David A.; Chao, Yi; Farrara, John D.; Frenzel, Hartmut; Jones, Burton; Robertson, George; McLaughlin, Karen; Sengupta, Ashmita

2014-01-01

Anthropogenic nutrients have been shown to provide significant sources of nitrogen (N) that have been linked to increased primary production and harmful algal blooms worldwide. There is a general perception that in upwelling regions, the flux of anthropogenic nutrient inputs is small relative to upwelling flux, and therefore anthropogenic inputs have relatively little effect on the productivity of coastal waters. To test the hypothesis that natural sources (e.g., upwelling) greatly exceed anthropogenic nutrient sources to the Southern California Bight (SCB), this study compared the source contributions of N from four major nutrient sources: (1) upwelling, (2) treated wastewater effluent discharged to ocean outfalls, (3) riverine runoff, and (4) atmospheric deposition. This comparison was made using large regional data sets combined with modeling on both regional and local scales. At the regional bight-wide spatial scale, upwelling was the largest source of N by an order of magnitude to effluent and two orders of magnitude to riverine runoff. However, at smaller spatial scales, more relevant to algal bloom development, natural and anthropogenic contributions were equivalent. In particular, wastewater effluent and upwelling contributed the same quantity of N in several subregions of the SCB. These findings contradict the currently held perception that in upwelling-dominated regions anthropogenic nutrient inputs are negligible, and suggest that anthropogenic nutrients, mainly wastewater effluent, can provide a significant source of nitrogen for nearshore productivity in Southern California coastal waters.

Anthropogenic nutrient sources rival natural sources on small scales in the coastal waters of the Southern California Bight

KAUST Repository

Howard, Meredith D. A.

2014-01-26

Anthropogenic nutrients have been shown to provide significant sources of nitrogen (N) that have been linked to increased primary production and harmful algal blooms worldwide. There is a general perception that in upwelling regions, the flux of anthropogenic nutrient inputs is small relative to upwelling flux, and therefore anthropogenic inputs have relatively little effect on the productivity of coastal waters. To test the hypothesis that natural sources (e.g., upwelling) greatly exceed anthropogenic nutrient sources to the Southern California Bight (SCB), this study compared the source contributions of N from four major nutrient sources: (1) upwelling, (2) treated wastewater effluent discharged to ocean outfalls, (3) riverine runoff, and (4) atmospheric deposition. This comparison was made using large regional data sets combined with modeling on both regional and local scales. At the regional bight-wide spatial scale, upwelling was the largest source of N by an order of magnitude to effluent and two orders of magnitude to riverine runoff. However, at smaller spatial scales, more relevant to algal bloom development, natural and anthropogenic contributions were equivalent. In particular, wastewater effluent and upwelling contributed the same quantity of N in several subregions of the SCB. These findings contradict the currently held perception that in upwelling-dominated regions anthropogenic nutrient inputs are negligible, and suggest that anthropogenic nutrients, mainly wastewater effluent, can provide a significant source of nitrogen for nearshore productivity in Southern California coastal waters.

18 CFR 2.400 - Statement of interpretation of waste concerning natural gas as the primary energy source for...

Science.gov (United States)

2010-04-01

... interpretation of waste concerning natural gas as the primary energy source for qualifying small power production... concerning natural gas as the primary energy source for qualifying small power production facilities. For purposes of deciding whether natural gas may be considered as waste as the primary energy source pursuant...

Investigation of source location determination from Magsat magnetic anomalies: The Euler method approach

Science.gov (United States)

Ravat, Dhananjay

1996-01-01

The applicability of the Euler method of source location determination was investigated on several model situations pertinent to satellite-data scale situations as well as Magsat data of Europe. Our investigations enabled us to understand the end-member cases for which the Euler method will work with the present satellite magnetic data and also the cases for which the assumptions implicit in the Euler method will not be met by the present satellite magnetic data. These results have been presented in one invited lecture at the Indo-US workshop on Geomagnetism in Studies of the Earth's Interior in August 1994 in Pune, India, and at one presentation at the 21st General Assembly of the IUGG in July 1995 in Boulder, CO. A new method, called Anomaly Attenuation Rate (AAR) Method (based on the Euler method), was developed during this study. This method is scale-independent and is appropriate to locate centroids of semi-compact three dimensional sources of gravity and magnetic anomalies. The method was presented during 1996 Spring AGU meeting and a manuscript describing this method is being prepared for its submission to a high-ranking journal. The grant has resulted in 3 papers and presentations at national and international meetings and one manuscript of a paper (to be submitted shortly to a reputable journal).

Laying hens behave differently in artificially and naturally sourced ammoniated environments.

Science.gov (United States)

Pokharel, B B; Dos Santos, V M; Wood, D; Van Heyst, B; Harlander-Matauschek, A

2017-12-01

Laying hens are chronically exposed to high levels of ammonia (NH3), one of the most abundant aerial pollutants in poultry houses. Tests for aversion to NH3 in laying hens have used artificially sourced NH3/air mixtures (i.e., from a gas cylinder) showing that birds prefer fresh air to NH3. However, artificially sourced NH3/air mixtures may not accurately reflect barn air conditions, where manure emits a variety of gases. Herein, we investigated whether laying hens differentiate between artificially and naturally sourced NH3/air mixtures and how exposure to NH3 affects foraging and aversive behavior. A total of 20 laying hens was exposed to artificially sourced [A] (from an anhydrous NH3 cylinder) and naturally sourced [N] (from conspecific laying hen excreta) gas mixtures. Hens were exposed to A and N mixtures with NH3 concentrations of 25 and 45 ppm, as well as fresh air [FA]. During the experiment, all birds were exposed to each treatment 3 times using a custom-built polycarbonate chamber, containing a foraging area (containing raisins, mealworms, and feed mix) and a gas delivery system. All testing sessions were video recorded, analyzed with INTERACT® software, and subjected to a GLIMMIX procedure in SAS. Our results showed that the laying hens spent less time foraging overall (P hens were more likely to forage for a longer time (with fewer interruptions) in N than in A treatments (P hens also reacted with greater aversion towards treatment A compared to treatment N (P hens of our study preferred fresh to ammoniated air and that they behaved differently in artificially and naturally sourced NH3/air mixtures, possibly due to the presence of familiar stimuli from the excreta. These findings have implications for new developments in methodological approaches for behavioral testing and for recommendations regarding NH3 levels inside poultry barns. © 2017 Poultry Science Association Inc.

Locating single-point sources from arrival times containing large picking errors (LPEs): the virtual field optimization method (VFOM)

Science.gov (United States)

Li, Xi-Bing; Wang, Ze-Wei; Dong, Long-Jun

2016-01-01

Microseismic monitoring systems using local location techniques tend to be timely, automatic and stable. One basic requirement of these systems is the automatic picking of arrival times. However, arrival times generated by automated techniques always contain large picking errors (LPEs), which may make the location solution unreliable and cause the integrated system to be unstable. To overcome the LPE issue, we propose the virtual field optimization method (VFOM) for locating single-point sources. In contrast to existing approaches, the VFOM optimizes a continuous and virtually established objective function to search the space for the common intersection of the hyperboloids, which is determined by sensor pairs other than the least residual between the model-calculated and measured arrivals. The results of numerical examples and in-site blasts show that the VFOM can obtain more precise and stable solutions than traditional methods when the input data contain LPEs. Furthermore, we discuss the impact of LPEs on objective functions to determine the LPE-tolerant mechanism, velocity sensitivity and stopping criteria of the VFOM. The proposed method is also capable of locating acoustic sources using passive techniques such as passive sonar detection and acoustic emission.

Tracking natural and anthropogenic Pb exposure to its geological source.

Science.gov (United States)

Evans, Jane; Pashley, Vanessa; Madgwick, Richard; Neil, Samantha; Chenery, Carolyn

2018-01-31

Human Pb exposure comes from two sources: (i) natural uptake through ingestion of soils and typified by populations that predate mining activity and (ii) anthropogenic exposure caused by the exposure to Pb derived from ore deposits. Currently, the measured concentration of Pb within a sample is used to discriminate between these two exposure routes, with the upper limit for natural exposure in skeletal studies given as 0.5 or 0.7 mg/kg in enamel and 0.5/0.7 μg/dL in blood. This threshold approach to categorising Pb exposure does not distinguish between the geological origins of the exposure types. However, Pb isotopes potentially provide a more definitive means of discriminating between sources. Whereas Pb from soil displays a crustal average 238 U/ 204 Pb (μ) value of c 9.7, Pb from ore displays a much wider range of evolution pathways. These characteristics are transferred into tooth enamel, making it possible to characterize human Pb exposure in terms of the primary source of ingested Pb and to relate mining activity to geotectonic domains. We surmise that this ability to discriminate between silicate and sulphide Pb exposure will lead to a better understanding of the evolution of early human mining activity and development of exposure models through the Anthropocene.

The emergent natural gas markets

International Nuclear Information System (INIS)

Dewert, F.; Meeder, J.

1998-01-01

A 30% increase of natural gas consumption worldwide is expected to occur since the year 2010. This development will concern countries located outside the traditional markets, in particular in central and eastern Europe, Asia, Africa and south America. This paper summarizes the talks given by the different representatives of these regions who explain the expected evolutions of the natural gas market in these areas: reserves, production, consumption, demand, competition with other energy sources, financial aspects.. (J.S.)

Consumption of added sugars among US children and adults by food purchase location and food source.

Science.gov (United States)

Drewnowski, Adam; Rehm, Colin D

2014-09-01

The proposed changes to the Nutrition Facts Label by the US Food and Drug Administration will include information on added sugars for the first time. The objective was to evaluate the sources of added sugars in the diets of a representative sample of US children and adults by food purchase location and food source (eg, food group). This cross-sectional study among 31,035 children, adolescents, and adults aged ≥6 y from the 2003-2004, 2005-2006, 2007-2008, and 2009-2010 NHANES used data from a 24-h dietary recall to evaluate consumption of added sugars. Food locations of origin were identified as stores (supermarket or grocery store), quick-service restaurants/pizza (QSRs), full-service restaurants (FSRs), schools, and others (eg, vending machines or gifts). Added sugars consumption by food purchase location was evaluated by age, family income-to-poverty ratio, and race-ethnicity. Food group sources of added sugars were identified by using the National Cancer Institute food categories. Added sugars accounted for ∼14.1% of total dietary energy. Between 65% and 76% of added sugars came from stores, 6% and 12% from QSRs, and 4% and 6% from FSRs, depending on age. Older adults (aged ≥51 y) obtained a significantly greater proportion of added sugars from stores than did younger adults. Lower-income adults obtained a significantly greater proportion of added sugars from stores than did higher-income adults. Intake of added sugars did not vary by family income among children/adolescents. Soda and energy and sports drinks were the largest food group sources of added sugars (34.4%), followed by grain desserts (12.7%), fruit drinks (8.0%), candy (6.7%), and dairy desserts (5.6%). Most added sugars came from foods obtained from stores. The proposed changes to the Nutrition Facts Label should capture the bulk of added sugars in the US food supply, which suggests that the recommended changes have the potential to reduce added sugars consumption. © 2014 American Society

Radiation measurement practice for understanding statistical fluctuation of radiation count using natural radiation sources

International Nuclear Information System (INIS)

Kawano, Takao

2014-01-01

It is known that radiation is detected at random and the radiation counts fluctuate statistically. In the present study, a radiation measurement experiment was performed to understand the randomness and statistical fluctuation of radiation counts. In the measurement, three natural radiation sources were used. The sources were fabricated from potassium chloride chemicals, chemical fertilizers and kelps. These materials contain naturally occurring potassium-40 that is a radionuclide. From high schools, junior high schools and elementary schools, nine teachers participated to the radiation measurement experiment. Each participant measured the 1-min integration counts of radiation five times using GM survey meters, and 45 sets of data were obtained for the respective natural radiation sources. It was found that the frequency of occurrence of radiation counts was distributed according to a Gaussian distribution curve, although the obtained 45 data sets of radiation counts superficially looked to be fluctuating meaninglessly. (author)

Metamaterials-based sensor to detect and locate nonlinear elastic sources

Energy Technology Data Exchange (ETDEWEB)

Gliozzi, Antonio S.; Scalerandi, Marco [Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Miniaci, Marco; Bosia, Federico [Department of Physics, University of Torino, Via Pietro Giuria 1, 10125 Torino (Italy); Pugno, Nicola M. [Laboratory of Bio-Inspired and Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento (Italy); Center for Materials and Microsystems, Fondazione Bruno Kessler, Via Sommarive 18, 38123 Povo (Trento) (Italy); School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom)

2015-10-19

In recent years, acoustic metamaterials have attracted increasing scientific interest for very diverse technological applications ranging from sound abatement to ultrasonic imaging, mainly due to their ability to act as band-stop filters. At the same time, the concept of chaotic cavities has been recently proposed as an efficient tool to enhance the quality of nonlinear signal analysis, particularly in the ultrasonic/acoustic case. The goal of the present paper is to merge the two concepts in order to propose a metamaterial-based device that can be used as a natural and selective linear filter for the detection of signals resulting from the propagation of elastic waves in nonlinear materials, e.g., in the presence of damage, and as a detector for the damage itself in time reversal experiments. Numerical simulations demonstrate the feasibility of the approach and the potential of the device in providing improved signal-to-noise ratios and enhanced focusing on the defect locations.

Metamaterials-based sensor to detect and locate nonlinear elastic sources

International Nuclear Information System (INIS)

Gliozzi, Antonio S.; Scalerandi, Marco; Miniaci, Marco; Bosia, Federico; Pugno, Nicola M.

2015-01-01

In recent years, acoustic metamaterials have attracted increasing scientific interest for very diverse technological applications ranging from sound abatement to ultrasonic imaging, mainly due to their ability to act as band-stop filters. At the same time, the concept of chaotic cavities has been recently proposed as an efficient tool to enhance the quality of nonlinear signal analysis, particularly in the ultrasonic/acoustic case. The goal of the present paper is to merge the two concepts in order to propose a metamaterial-based device that can be used as a natural and selective linear filter for the detection of signals resulting from the propagation of elastic waves in nonlinear materials, e.g., in the presence of damage, and as a detector for the damage itself in time reversal experiments. Numerical simulations demonstrate the feasibility of the approach and the potential of the device in providing improved signal-to-noise ratios and enhanced focusing on the defect locations

Transport of perfluoroalkyl substances (PFAS) from an arctic glacier to downstream locations: implications for sources.

Science.gov (United States)

Kwok, Karen Y; Yamazaki, Eriko; Yamashita, Nobuyoshi; Taniyasu, Sachi; Murphy, Margaret B; Horii, Yuichi; Petrick, Gert; Kallerborn, Roland; Kannan, Kurunthachalam; Murano, Kentaro; Lam, Paul K S

2013-03-01

Perfluoroalkyl substances (PFAS) have been globally detected in various environmental matrices, yet their fate and transport to the Arctic is still unclear, especially for the European Arctic. In this study, concentrations of 17 PFAS were quantified in two ice cores (n=26), surface snow (n=9) and surface water samples (n=14) collected along a spatial gradient in Svalbard, Norway. Concentrations of selected ions (Na(+), SO4(2-), etc.) were also determined for tracing the origins and sources of PFAS. Perfluorobutanoate (PFBA), perfluorooctanoate (PFOA) and perfluorononanoate (PFNA) were the dominant compounds found in ice core samples. Taking PFOA, PFNA and perfluorooctane-sulfonate (PFOS) as examples, higher concentrations were detected in the middle layers of the ice cores representing the period of 1997-2000. Lower concentrations of C8-C12 perfluorocarboxylates (PFCAs) were detected in comparison with concentrations measured previously in an ice core from the Canadian Arctic, indicating that contamination levels in the European Arctic are lower. Average PFAS concentrations were found to be lower in surface snow and melted glacier water samples, while increased concentrations were observed in river water downstream near the coastal area. Perfluorohexanesulfonate (PFHxS) was detected in the downstream locations, but not in the glacier, suggesting existence of local sources of this compound. Long-range atmospheric transport of PFAS was the major deposition pathway for the glaciers, while local sources (e.g., skiing activities) were identified in the downstream locations. Copyright © 2012 Elsevier B.V. All rights reserved.

Natural radiation sources fabricated from potassic chemical fertilizers and application to radiation education

International Nuclear Information System (INIS)

Kawano, Takao

2010-01-01

Potassic chemical fertilizers contain potassium, a small part of which is potassium-40. Since potassium-40 is a naturally occurring radioisotope, potassic chemical fertilizers are often used for demonstrations of the existence of natural radioisotopes and radiation. To fabricate radiation sources as educational tools, the compression and formation method developed by our previous study was applied to 13 brands of commercially available chemical fertilizers containing different amounts of potassium. The suitability (size, weight, and solidness) of thus fabricated sources was examined and 12 of them were selected as easy-to-use radiation sources at radiation educational courses. The radiation strength (radiation count rate measured by a GM survey meter) and potassium content of the 12 sources were examined. It was found that the count rate was wholly proportional to the percentage of potassium, and a new educational application was proposed and discussed for understanding that the substance emitting radiation must be the potassium present in the raw fertilizers. (author)

Comparison of imaging modalities and source-localization algorithms in locating the induced activity during deep brain stimulation of the STN.

Science.gov (United States)

Mideksa, K G; Singh, A; Hoogenboom, N; Hellriegel, H; Krause, H; Schnitzler, A; Deuschl, G; Raethjen, J; Schmidt, G; Muthuraman, M

2016-08-01

One of the most commonly used therapy to treat patients with Parkinson's disease (PD) is deep brain stimulation (DBS) of the subthalamic nucleus (STN). Identifying the most optimal target area for the placement of the DBS electrodes have become one of the intensive research area. In this study, the first aim is to investigate the capabilities of different source-analysis techniques in detecting deep sources located at the sub-cortical level and validating it using the a-priori information about the location of the source, that is, the STN. Secondly, we aim at an investigation of whether EEG or MEG is best suited in mapping the DBS-induced brain activity. To do this, simultaneous EEG and MEG measurement were used to record the DBS-induced electromagnetic potentials and fields. The boundary-element method (BEM) have been used to solve the forward problem. The position of the DBS electrodes was then estimated using the dipole (moving, rotating, and fixed MUSIC), and current-density-reconstruction (CDR) (minimum-norm and sLORETA) approaches. The source-localization results from the dipole approaches demonstrated that the fixed MUSIC algorithm best localizes deep focal sources, whereas the moving dipole detects not only the region of interest but also neighboring regions that are affected by stimulating the STN. The results from the CDR approaches validated the capability of sLORETA in detecting the STN compared to minimum-norm. Moreover, the source-localization results using the EEG modality outperformed that of the MEG by locating the DBS-induced activity in the STN.

Santa Barbara Littoral Cell CRSMP Offshore Sand Sources 2009

Data.gov (United States)

California Natural Resource Agency — Offshore sand sources exist at four known locations and potentially other yet to be explored regions within the nearshore coastal shelf. Significant reserves of fine...

FLAVONOID NATURAL SOURCES AND THEIR IMPORTANCE IN THE HUMAN DIET

Directory of Open Access Journals (Sweden)

Martina Danihelová

2011-12-01

Full Text Available Flavonoids as natural bioactive compounds are present in almost every sort of fruits, vegetables and from them derived products. Flavonols may be found mainly in fruits and vegetables, while flavones are abundant in herbs and spices. Rich natural sources of flavanols are tea, cocoa, grape seeds or apple skin. Flavanones are primarily found in a variety of citrus fruits and anthocyanidins in many coloured berries. Soy is rich in isoflavonoids. Average daily intake of flavonoids is approximately in the range of 150 to 300 mg. It strongly depends on individual, country and culture usages. In west countries main dietary sources of flavonoids consist of tea, wine and fruits, while in east countries there is consumed mainly soy with high isoflavonoid content. Many studies have shown, that intake of fruits and vegetables with high flavonoid content is associated with lowered risk of incidence of some diseases such as cardiovascular or cancer. These findings are attributed to experimentally confirmed biological effects of flavonoids - antioxidant, anti-inflammatory, anti-allergic, anticancer or cardioprotective. The final effect is however depending on their bioavailability, which is in the case of flavonoids not high, because in the nature dominating flavonoid glycosides can poorly penetrate through lipophilic cell membranes. Final effective molecules are flavonoid metabolites, that more or less retain their biological activities. doi: 10.5219/160

Apparatus and method for locating and quantifying or directing a source of ionizing radiation

International Nuclear Information System (INIS)

Rogers, W.L.; Wainstock, M.A.

1976-01-01

An apparatus and method for locating or directing a source of ionizing radiation such as X-rays, gamma rays, alpha particles, beta particles, etc. are described. The preferred embodiment detects and locates abnormalities of the body such as ocular melanomas by detecting the emission of radiation from a melanoma which has absorbed a radioactive medium. The apparatus includes an ultrasound probe which emits ultrasonic waves along a first axis and detects a returned portion of the waves. The ultrasound probe is associated with a display which displays the returned portion of the waves in the time domain so that suspected abnormalities can be located. The ultrasound probe is used to guide a directional probe for detecting and quantifying ionizing radiation which is equipped with a focusing collimator having a focal point along a second axis. The two probes are supported so that the first and second axes converge at the focal point of the collimator. A range marker is associated with the ultrasonic detector which indicates the point of convergence of the axes on the ultrasonic display permitting guidance of the radiation detecting probe to the suspected abnormality

Isolation and Preparation of Nanoscale Bioapatites from Natural Sources: A Review

Czech Academy of Sciences Publication Activity Database

Šupová, Monika

2014-01-01

Roč. 14, č. 1 (2014), s. 546-563 ISSN 1533-4880 R&D Projects: GA ČR(CZ) GA106/09/1000 Institutional support: RVO:67985891 Keywords : bioapatites * calcium phosphate * hydroxyapatite * natural sources Subject RIV: JJ - Other Materials Impact factor: 1.556, year: 2014

Using social media to quantify nature-based tourism and recreation.

Science.gov (United States)

Wood, Spencer A; Guerry, Anne D; Silver, Jessica M; Lacayo, Martin

2013-10-17

Scientists have traditionally studied recreation in nature by conducting surveys at entrances to major attractions such as national parks. This method is expensive and provides limited spatial and temporal coverage. A new source of information is available from online social media websites such as flickr. Here, we test whether this source of "big data" can be used to approximate visitation rates. We use the locations of photographs in flickr to estimate visitation rates at 836 recreational sites around the world, and use information from the profiles of the photographers to derive travelers' origins. We compare these estimates to empirical data at each site and conclude that the crowd-sourced information can indeed serve as a reliable proxy for empirical visitation rates. This new approach offers opportunities to understand which elements of nature attract people to locations around the globe, and whether changes in ecosystems will alter visitation rates.

Southern Monterey Bay Littoral Cell CRSMP Potential Sediment Sources 2008

Data.gov (United States)

California Natural Resource Agency — Three main criteria are used as an initial basis for screening source locations; availability of large quantities of beach compatible sand, levels of contamination,...

Mercury-impacted scrap metal: Source and nature of the mercury.

Science.gov (United States)

Finster, Molly E; Raymond, Michelle R; Scofield, Marcienne A; Smith, Karen P

2015-09-15

The reuse and recycling of industrial solid wastes such as scrap metal is supported and encouraged both internationally and domestically, especially when such wastes can be used as substitutes for raw material. However, scrap metal processing facilities, such as mini-mills, have been identified as a source of mercury (Hg) emissions in the United States. This research aims to better define some of the key issues related to the source and nature of mercury in the scrap metal waste stream. Overall, it is difficult to pinpoint the key mercury sources feeding into scrap metal recycling facilities, quantify their associated mercury concentrations, or determine which chemical forms are most significant. Potential sources of mercury in scrap metal include mercury switches from discarded vehicles, electronic-based scrap from household appliances and related industrial systems, and Hg-impacted scrap metal from the oil and gas industry. The form of mercury associated with scrap metal varies and depends on the source type. The specific amount of mercury that can be adsorbed and retained by steel appears to be a function of both metallurgical and environmental factors. In general, the longer the steel is in contact with a fluid or condensate that contains measurable concentrations of elemental mercury, the greater the potential for mercury accumulation in that steel. Most mercury compounds are thermally unstable at elevated temperatures (i.e., above 350 °C). As such, the mercury associated with impacted scrap is expected to be volatilized out of the metal when it is heated during processing (e.g., shredding or torch cutting) or melted in a furnace. This release of fugitive gas (Hg vapor) and particulates, as well as Hg-impacted bag-house dust and control filters, could potentially pose an occupational exposure risk to workers at a scrap metal processing facility. Thus, identifying and characterizing the key sources of Hg-impacted scrap, and understanding the nature and extent

Consumption of added sugars among US children and adults by food purchase location and food source123

Science.gov (United States)

Drewnowski, Adam; Rehm, Colin D

2014-01-01

Background: The proposed changes to the Nutrition Facts Label by the US Food and Drug Administration will include information on added sugars for the first time. Objective: The objective was to evaluate the sources of added sugars in the diets of a representative sample of US children and adults by food purchase location and food source (eg, food group). Design: This cross-sectional study among 31,035 children, adolescents, and adults aged ≥6 y from the 2003–2004, 2005–2006, 2007–2008, and 2009–2010 NHANES used data from a 24-h dietary recall to evaluate consumption of added sugars. Food locations of origin were identified as stores (supermarket or grocery store), quick-service restaurants/pizza (QSRs), full-service restaurants (FSRs), schools, and others (eg, vending machines or gifts). Added sugars consumption by food purchase location was evaluated by age, family income-to-poverty ratio, and race-ethnicity. Food group sources of added sugars were identified by using the National Cancer Institute food categories. Results: Added sugars accounted for ∼14.1% of total dietary energy. Between 65% and 76% of added sugars came from stores, 6% and 12% from QSRs, and 4% and 6% from FSRs, depending on age. Older adults (aged ≥51 y) obtained a significantly greater proportion of added sugars from stores than did younger adults. Lower-income adults obtained a significantly greater proportion of added sugars from stores than did higher-income adults. Intake of added sugars did not vary by family income among children/adolescents. Soda and energy and sports drinks were the largest food group sources of added sugars (34.4%), followed by grain desserts (12.7%), fruit drinks (8.0%), candy (6.7%), and dairy desserts (5.6%). Conclusions: Most added sugars came from foods obtained from stores. The proposed changes to the Nutrition Facts Label should capture the bulk of added sugars in the US food supply, which suggests that the recommended changes have the potential to

Natural Offshore Oil Seepage and Related Tarball Accumulation on the California Coastline - Santa Barbara Channel and the Southern Santa Maria Basin: Source Identification and Inventory

Science.gov (United States)

Lorenson, T.D.; Hostettler, Frances D.; Rosenbauer, Robert J.; Peters, Kenneth E.; Dougherty, Jennifer A.; Kvenvolden, Keith A.; Gutmacher, Christina E.; Wong, Florence L.; Normark, William R.

2009-01-01

Oil spillage from natural sources is very common in the waters of southern California. Active oil extraction and shipping is occurring concurrently within the region and it is of great interest to resource managers to be able to distinguish between natural seepage and anthropogenic oil spillage. The major goal of this study was to establish the geologic setting, sources, and ultimate dispersal of natural oil seeps in the offshore southern Santa Maria Basin and Santa Barbara Basins. Our surveys focused on likely areas of hydrocarbon seepage that are known to occur between Point Arguello and Ventura, California. Our approach was to 1) document the locations and geochemically fingerprint natural seep oils or tar; 2) geochemically fingerprint coastal tar residues and potential tar sources in this region, both onshore and offshore; 3) establish chemical correlations between offshore active seeps and coastal residues thus linking seep sources to oil residues; 4) measure the rate of natural seepage of individual seeps and attempt to assess regional natural oil and gas seepage rates; and 5) interpret the petroleum system history for the natural seeps. To document the location of sub-sea oil seeps, we first looked into previous studies within and near our survey area. We measured the concentration of methane gas in the water column in areas of reported seepage and found numerous gas plumes and measured high concentrations of methane in the water column. The result of this work showed that the seeps were widely distributed between Point Conception east to the vicinity of Coal Oil Point, and that they by in large occur within the 3-mile limit of California State waters. Subsequent cruises used sidescan and high resolution seismic to map the seafloor, from just south of Point Arguello, east to near Gaviota, California. The results of the methane survey guided the exploration of the area west of Point Conception east to Gaviota using a combination of seismic instruments. The

Fuel from Wastewater - Harnessing a Potential Energy Source in Canada through the Co-location of Algae Biofuel Production to Sources of Effluent, Heat and CO2

Science.gov (United States)

Klise, G. T.; Roach, J. D.; Passell, H. D.; Moreland, B. D.; O'Leary, S. J.; Pienkos, P. T.; Whalen, J.

2010-12-01

Sandia National Laboratories is collaborating with the National Research Council (NRC) Canada and the National Renewable Energy Laboratory (NREL) to develop a decision-support model that will evaluate the tradeoffs associated with high-latitude algae biofuel production co-located with wastewater, CO2, and waste heat. This project helps Canada meet its goal of diversifying fuel sources with algae-based biofuels. The biofuel production will provide a wide range of benefits including wastewater treatment, CO2 reuse and reduction of demand for fossil-based fuels. The higher energy density in algae-based fuels gives them an advantage over crop-based biofuels as the “production” footprint required is much less, resulting in less water consumed and little, if any conversion of agricultural land from food to fuel production. Besides being a potential source for liquid fuel, algae have the potential to be used to generate electricity through the burning of dried biomass, or anaerobically digested to generate methane for electricity production. Co-locating algae production with waste streams may be crucial for making algae an economically valuable fuel source, and will certainly improve its overall ecological sustainability. The modeling process will address these questions, and others that are important to the use of water for energy production: What are the locations where all resources are co-located, and what volumes of algal biomass and oil can be produced there? In locations where co-location does not occur, what resources should be transported, and how far, while maintaining economic viability? This work is being funded through the U.S. Department of Energy (DOE) Biomass Program Office of Energy Efficiency and Renewable Energy, and is part of a larger collaborative effort that includes sampling, strain isolation, strain characterization and cultivation being performed by the NREL and Canada’s NRC. Results from the NREL / NRC collaboration including specific

Competing sound sources reveal spatial effects in cortical processing.

Directory of Open Access Journals (Sweden)

Ross K Maddox

Full Text Available Why is spatial tuning in auditory cortex weak, even though location is important to object recognition in natural settings? This question continues to vex neuroscientists focused on linking physiological results to auditory perception. Here we show that the spatial locations of simultaneous, competing sound sources dramatically influence how well neural spike trains recorded from the zebra finch field L (an analog of mammalian primary auditory cortex encode source identity. We find that the location of a birdsong played in quiet has little effect on the fidelity of the neural encoding of the song. However, when the song is presented along with a masker, spatial effects are pronounced. For each spatial configuration, a subset of neurons encodes song identity more robustly than others. As a result, competing sources from different locations dominate responses of different neural subpopulations, helping to separate neural responses into independent representations. These results help elucidate how cortical processing exploits spatial information to provide a substrate for selective spatial auditory attention.

Investigation On Natural Background Radioactivity At TanLong, Lagi, BinhThuan Residential Area On Ilmenite Deposit Location

International Nuclear Information System (INIS)

Pham Thi Kim Loan; Tran Van Luyen; Thai Khac Dinh

2008-01-01

An Ilmenite deposit zone located at TanLong, Lagi, Binh Thuan province. After the year of 2000, a new village of population has set up at this place. To estimate the effect on the human health of radioactivity accompanying with the deposit, the sand samples were collected and natural radioactive analyzed at center for nuclear techniques. The average year doses D annual , hazard radiation exposed index H ex and Radium equivalence Ra eq were calculated based on the natural radioactivities. The results show that these factors are overcome the international average as well as southern Vietnam values. (author)

Lignicolous fungi as potential natural sources of antioxidants

Directory of Open Access Journals (Sweden)

Karaman Maja A.

2005-01-01

Full Text Available As a result of an interest in natural derived metabolites around the world higher fungi (Basidiomycotina have taken on great importance in biochemical investigations. A large number of structurally divergent compounds - both cellular components and secondary metabolites - have been extracted and found to possess significant biological activity, such as an immunomodulative effect on the human body. Effects of fungal biomolecules as potential natural antioxidants have not been examined so far. Biochemical analysis have included in vitro testing of the influence of different extracts (water methanol, chloroform of selected fungal sporocarps on Fe2+/ascorbate-induced lipid peroxidation (LP in a lecithin liposome system by TBA assay, as well as various other procedures. Qualitative analysis by TLC revealed a distinction both between different extracts of the same fungal species and between similar extracts of different species. The results obtained on antioxidative activities (LP inhibition and "scavenging" activity indicate that MeOH extracts manifested a degree of activity higher than that of CHCl3 extracts with respect to antioxidative activity, the extracts can be ranged in the following declining order: Ganoderma lucidum, Ganoderma applanatum Meripilus giganteus, and Flammulina velutipes. The obtained results suggest that the analyzed fungi are of potential interest as sources of strong natural antioxidants in the food and cosmetics industries, whereas synthetic ones have proved to be carcinogenic.

Source of radioactivity in the ocean environment

International Nuclear Information System (INIS)

Solomon, K.A.

1988-01-01

This paper summarizes both natural and man-made radioactivity in the marine environment. Radioactivity occurs naturally in both the sea water and in the ocean sediment. Radioactivity in the sea water is fairly uniform geographically and is dominated by the naturally occurring isotope 40/K (potassium-40). Unlike sea water, sediment radiation levels vary with sediment type and location. The primary source of natural radiation in the sediment results from deposition of insoluble thorium isotopes formed by the decay of water-soluble uranium. Man-made sources of radioactivity arise from, in descending order of importance: - sinking of two U.S. and two Soviet nuclear submarines; fallout from nuclear weapons testing; dumping of primarily British and Americal low-level nuclear waste; and dumping of reprocessing plant radiated effluents from the British Windscale facility and other European and Indian reprocessing facilities. 1 table

Location and nature of calcium-binding sites in salivary acidic proline-rich phosphoproteins

International Nuclear Information System (INIS)

Bennick, A.; McLaughlin, A.C.; Grey, A.A.; Madapallimattam, G.

1981-01-01

The location of the calcium-binding sites in the human acidic proline-rich proteins, salivary proteins A and C, was determined by equilibrium dialysis of the tryptic peptides with buffers containing 45 Ca. All the calcium-binding sites are located in the NH 2 -terminal tryptic peptide (TX peptide). The nature of the calcium binding sites in the TX peptide and native salivary proteins A and C, as well as dephosphorylated proteins was compared. Two types of sites can be distinguished in peptide TX. Type I sites have an apparent dissociation constant (K) of 38 μM and are responsible for the binding of 2.6 mol of Ca/mol of peptide. The corresponding figures for Type II sites are 780 μM and 5.3 mol of Ca/mol of peptide. In the native proteins, the amount of calcium bound at the type II sites decreases to 3.9 mol of Ca/mol of proteins A and C and K increases to 1100 μM. The amount of calcium bound at type I sites decreases to 1.5 mol/mol of protein A and 0.6 mol/mol of protein C, but there is no change in K. Dephosphorylation affects the calcium binding at both types of sites. The experiments indicate that the COOH-terminal parts of the native proteins affect the number and the nature of the protein calcium-binding sites. Proton and phosphorous NMR data demonstrate that β-COOH in aspartic acid, as well as phosphoserine, are part of the calcium-binding sites. The difference in calcium binding to salivary proteins A and C may be due at least partially to differences in the environment of one or more aspartic acids

Characterizing and locating air pollution sources in a complex industrial district using optical remote sensing technology and multivariate statistical modeling.

Science.gov (United States)

Chang, Pao-Erh Paul; Yang, Jen-Chih Rena; Den, Walter; Wu, Chang-Fu

2014-09-01

Emissions of volatile organic compounds (VOCs) are most frequent environmental nuisance complaints in urban areas, especially where industrial districts are nearby. Unfortunately, identifying the responsible emission sources of VOCs is essentially a difficult task. In this study, we proposed a dynamic approach to gradually confine the location of potential VOC emission sources in an industrial complex, by combining multi-path open-path Fourier transform infrared spectrometry (OP-FTIR) measurement and the statistical method of principal component analysis (PCA). Close-cell FTIR was further used to verify the VOC emission source by measuring emitted VOCs from selected exhaust stacks at factories in the confined areas. Multiple open-path monitoring lines were deployed during a 3-month monitoring campaign in a complex industrial district. The emission patterns were identified and locations of emissions were confined by the wind data collected simultaneously. N,N-Dimethyl formamide (DMF), 2-butanone, toluene, and ethyl acetate with mean concentrations of 80.0 ± 1.8, 34.5 ± 0.8, 103.7 ± 2.8, and 26.6 ± 0.7 ppbv, respectively, were identified as the major VOC mixture at all times of the day around the receptor site. As the toxic air pollutant, the concentrations of DMF in air samples were found exceeding the ambient standard despite the path-average effect of OP-FTIR upon concentration levels. The PCA data identified three major emission sources, including PU coating, chemical packaging, and lithographic printing industries. Applying instrumental measurement and statistical modeling, this study has established a systematic approach for locating emission sources. Statistical modeling (PCA) plays an important role in reducing dimensionality of a large measured dataset and identifying underlying emission sources. Instrumental measurement, however, helps verify the outcomes of the statistical modeling. The field study has demonstrated the feasibility of

Final Scientific Report, Integrated Seismic Event Detection and Location by Advanced Array Processing

Energy Technology Data Exchange (ETDEWEB)

Kvaerna, T.; Gibbons. S.J.; Ringdal, F; Harris, D.B.

2007-01-30

In the field of nuclear explosion monitoring, it has become a priority to detect, locate, and identify seismic events down to increasingly small magnitudes. The consideration of smaller seismic events has implications for a reliable monitoring regime. Firstly, the number of events to be considered increases greatly; an exponential increase in naturally occurring seismicity is compounded by large numbers of seismic signals generated by human activity. Secondly, the signals from smaller events become more difficult to detect above the background noise and estimates of parameters required for locating the events may be subject to greater errors. Thirdly, events are likely to be observed by a far smaller number of seismic stations, and the reliability of event detection and location using a very limited set of observations needs to be quantified. For many key seismic stations, detection lists may be dominated by signals from routine industrial explosions which should be ascribed, automatically and with a high level of confidence, to known sources. This means that expensive analyst time is not spent locating routine events from repeating seismic sources and that events from unknown sources, which could be of concern in an explosion monitoring context, are more easily identified and can be examined with due care. We have obtained extensive lists of confirmed seismic events from mining and other artificial sources which have provided an excellent opportunity to assess the quality of existing fully-automatic event bulletins and to guide the development of new techniques for online seismic processing. Comparing the times and locations of confirmed events from sources in Fennoscandia and NW Russia with the corresponding time and location estimates reported in existing automatic bulletins has revealed substantial mislocation errors which preclude a confident association of detected signals with known industrial sources. The causes of the errors are well understood and are

Final Scientific Report, Integrated Seismic Event Detection and Location by Advanced Array Processing

International Nuclear Information System (INIS)

Kvaerna, T.; Gibbons. S.J.; Ringdal, F; Harris, D.B.

2007-01-01

In the field of nuclear explosion monitoring, it has become a priority to detect, locate, and identify seismic events down to increasingly small magnitudes. The consideration of smaller seismic events has implications for a reliable monitoring regime. Firstly, the number of events to be considered increases greatly; an exponential increase in naturally occurring seismicity is compounded by large numbers of seismic signals generated by human activity. Secondly, the signals from smaller events become more difficult to detect above the background noise and estimates of parameters required for locating the events may be subject to greater errors. Thirdly, events are likely to be observed by a far smaller number of seismic stations, and the reliability of event detection and location using a very limited set of observations needs to be quantified. For many key seismic stations, detection lists may be dominated by signals from routine industrial explosions which should be ascribed, automatically and with a high level of confidence, to known sources. This means that expensive analyst time is not spent locating routine events from repeating seismic sources and that events from unknown sources, which could be of concern in an explosion monitoring context, are more easily identified and can be examined with due care. We have obtained extensive lists of confirmed seismic events from mining and other artificial sources which have provided an excellent opportunity to assess the quality of existing fully-automatic event bulletins and to guide the development of new techniques for online seismic processing. Comparing the times and locations of confirmed events from sources in Fennoscandia and NW Russia with the corresponding time and location estimates reported in existing automatic bulletins has revealed substantial mislocation errors which preclude a confident association of detected signals with known industrial sources. The causes of the errors are well understood and are

Nature and magnitude of the problem of spent radiation sources

International Nuclear Information System (INIS)

1991-09-01

Various types of sealed radiation sources are widely used in industry, medicine and research. Virtually all countries have some sealed sources. The activity in the sources varies from kilobecquerels in consumer products to hundreds of pentabecquerels in facilities for food irradiation. Loss or misuse of sealed sources can give rise to accidents resulting in radiation exposure of workers and members of the general public, and can also give rise to extensive contamination of land, equipment and buildings. In extreme cases the exposure can be lethal. Problems of safety relating to spent radiation sources have been under consideration within the Agency for some years. The first objective of the project has been to prepare a comprehensive report reviewing the nature and background of the problem, also giving an overview of existing practices for the management of spent radiation sources. This report is the fulfilment of this first objective. The safe management of spent radiation sources cannot be studied in isolation from their normal use, so it has been necessary to include some details which are relevant to the use of radiation sources in general, although that area is outside the scope of this report. The report is limited to radiation sources made up of radioactive material. The Agency is implementing a comprehensive action plan for assistance to Member States, especially the developing countries, in all aspects of the safe management of spent radiation sources. The Agency is further seeking to establish regional or global solutions to the problems of long-term storage of spent radiation sources, as well as finding routes for the disposal of sources when it is not feasible to set up safe national solutions. The cost of remedial actions after an accident with radiation sources can be very high indeed: millions of dollars. If the Agency can help to prevent even one such single accident, the cost of its whole programme in this field would be more than covered. Refs

Natural radioactivity in some drinking water sources of coastal, northern, eastern and AlJazera regions in Syria

International Nuclear Information System (INIS)

Al-Masri, M. S.; Byrakdar, E.; Amin, Y.; Abu Baker, S.

2003-01-01

Naturally occurring radionuclides in drinking water sources of coastal, northern, eastern and AlJazera regions in Syria have been determined. Samples were collected during the year of 2000 at two periods from the main water sources, from which water being transported for drinking or from houses. Results have shown that most concentrations of the measured naturally occurring radionuclides ( 222 Rn, 222 Ra, 210 Po, 234 U, 238 U) were within the natural levels and below the higher permissible limits of International Organizations. In addition, variations in concentrations from region to another have been observed; these variations may be due to differences in geological formations and water sources (well, spring, surface water). Moreover, the obtained data in this study and other published data for other regions can be used for establishing the radiation map for natural radioactivity in drinking water in Syria. (author)

Electrophysiological correlates of predictive coding of auditory location in the perception of natural audiovisual events.

Science.gov (United States)

Stekelenburg, Jeroen J; Vroomen, Jean

2012-01-01

In many natural audiovisual events (e.g., a clap of the two hands), the visual signal precedes the sound and thus allows observers to predict when, where, and which sound will occur. Previous studies have reported that there are distinct neural correlates of temporal (when) versus phonetic/semantic (which) content on audiovisual integration. Here we examined the effect of visual prediction of auditory location (where) in audiovisual biological motion stimuli by varying the spatial congruency between the auditory and visual parts. Visual stimuli were presented centrally, whereas auditory stimuli were presented either centrally or at 90° azimuth. Typical sub-additive amplitude reductions (AV - V audiovisual interaction was also found at 40-60 ms (P50) in the spatially congruent condition, while no effect of congruency was found on the suppression of the P2. This indicates that visual prediction of auditory location can be coded very early in auditory processing.

Three-dimensional illusion thermal device for location camouflage.

Science.gov (United States)

Wang, Jing; Bi, Yanqiang; Hou, Quanwen

2017-08-08

Thermal metamaterials, proposed in recent years, provide a new method to manipulate the energy flux in heat transfer, and result in many novel thermal devices. In this paper, an illusion thermal device for location camouflage in 3-dimensional heat conduction regime is proposed based on the transformation thermodynamics. The heat source covered by the device produces a fake signal outside the device, which makes the source look like appearing at another position away from its real position. The parameters required by the device are deduced and the method is validated by simulations. The possible scheme to obtain the thermal conductivities required in the device by composing natural materials is supplied, and the influence of some problems in practical fabrication process of the device on the effect of the camouflage is also discussed.

The January 2014 Northern Cuba Earthquake Sequence - Unusual Location and Unexpected Source Mechanism Variability

Science.gov (United States)

Braunmiller, J.; Thompson, G.; McNutt, S. R.

2017-12-01

On 9 January 2014, a magnitude Mw=5.1 earthquake occurred along the Bahamas-Cuba suture at the northern coast of Cuba revealing a surprising seismic hazard source for both Cuba and southern Florida where it was widely felt. Due to its location, the event and its aftershocks (M>3.5) were recorded only at far distances (300+ km) resulting in high-detection thresholds, low location accuracy, and limited source parameter resolution. We use three-component regional seismic data to study the sequence. High-pass filtered seismograms at the closest site in southern Florida are similar in character suggesting a relatively tight event cluster and revealing additional, smaller aftershocks not included in the ANSS or ISC catalogs. Aligning on the P arrival and low-pass filtering (T>10 s) uncovers a surprise polarity flip of the large amplitude surface waves on vertical seismograms for some aftershocks relative to the main shock. We performed regional moment tensor inversions of the main shock and its largest aftershocks using complete three-component seismograms from stations distributed throughout the region to confirm the mechanism changes. Consistent with the GCMT solution, we find an E-W trending normal faulting mechanism for the main event and for one immediate aftershock. Two aftershocks indicate E-W trending reverse faulting with essentially flipped P- and T-axes relative to the normal faulting events (and the same B-axes). Within uncertainties, depths of the two event families are indistinguishable and indicate shallow faulting (<10 km). One intriguing possible interpretation is that both families ruptured the same fault with reverse mechanisms compensating for overshooting. However, activity could also be spatially separated either vertically (with reverse mechanisms possibly below extension) or laterally. The shallow source depth and the 200-km long uplifted chain of islands indicate that larger, shallow and thus potentially tsunamigenic earthquakes could occur just

Natural hybridization and introgression between Ligularia cymbulifera and L. tongolensis (Asteraceae, Senecioneae) in four different locations.

Science.gov (United States)

Yu, Jiaojun; Kuroda, Chiaki; Gong, Xun

2014-01-01

Natural hybridization has been considered to represent an important factor influencing the high diversity of the genus Ligularia Cass. in the Hengduan Mountains, China. Natural hybridization has been confirmed to occur frequently in Ligularia. To date, however, it has been demonstrated only within a single population. In this paper, we present evidence of natural hybridization in Ligularia from four different locations. The internal transcribed spacer (ITS) region of the nuclear ribosomal DNA and three chloroplast intergenic spacers (trnK-rps16, trnL-rpl32 and trnQ-5'rps16) of 149 accessions of putative hybrids and their putative parents (L. cymbulifera and L. tongolensis) were analyzed for evidence of hybridization. The ITS data clearly distinguished two putative parental species and sympatric L. vellerea and supported the hypothesis that those morphological intermediates were products of natural hybridization between L. cymbulifera and L. tongolensis. Moreover, several identified morphological parents were actual introgressed products. Because of hybridization and introgression, chloroplast DNA sequences generated a poorly resolved network. The present results indicate that varying degrees of hybridization and introgression occur differently depending on the habitat context. We conclude that gene flow caused by natural hybridization in Ligularia indeed plays an important role in the species diversity.

A Requirements-Based Exploration of Open-Source Software Development Projects--Towards a Natural Language Processing Software Analysis Framework

Science.gov (United States)

Vlas, Radu Eduard

2012-01-01

Open source projects do have requirements; they are, however, mostly informal, text descriptions found in requests, forums, and other correspondence. Understanding such requirements provides insight into the nature of open source projects. Unfortunately, manual analysis of natural language requirements is time-consuming, and for large projects,…

An improved cut-and-solve algorithm for the single-source capacitated facility location problem

DEFF Research Database (Denmark)

Gadegaard, Sune Lauth; Klose, Andreas; Nielsen, Lars Relund

2018-01-01

In this paper, we present an improved cut-and-solve algorithm for the single-source capacitated facility location problem. The algorithm consists of three phases. The first phase strengthens the integer program by a cutting plane algorithm to obtain a tight lower bound. The second phase uses a two......-level local branching heuristic to find an upper bound, and if optimality has not yet been established, the third phase uses the cut-and-solve framework to close the optimality gap. Extensive computational results are reported, showing that the proposed algorithm runs 10–80 times faster on average compared...

Cranberry: A good source of natural antioxidants

Directory of Open Access Journals (Sweden)

Tumbas Vesna T.

2006-01-01

Full Text Available The influence of extracts of cranbeny fruit and mixed tea (containing 40% cranberry on stable 1,1-diphenyl-2-picrylhydrazyl (DPPH radicals has been investigated by electron spin resonance (ESR spectroscopy. All investigated extracts possess very high antioxidant activity, which increased dose-dependently at mass concentrations ranging from 0.5 to 3.5 mg/ml. The high contents of phenolic s (3.60-4.52 mg/g, anthocyanins (0.23-1.52 mg/g, flavan-3-ols (1.25-3.05 mg/g and vitamin C (0.07-0.15 mg/g in investigated extracts indicated that these compounds significantly contributed to the antioxidant activity. All these results show that the extracts of cranberry fruit and mixed tea can be used as easily accessible source of natural antioxidants and as a possible food supplement.

SU-G-JeP3-09: Tumor Location Prediction Using Natural Respiratory Volume for Respiratory Gated Radiation Therapy (RGRT): System Verification Study

Energy Technology Data Exchange (ETDEWEB)

Kim, M; Jung, J; Yoon, D; Shin, H; Kim, S; Suh, T [The catholic university of Korea, Seoul (Korea, Republic of)

2016-06-15

Purpose: Respiratory gated radiation therapy (RGRT) gives accurate results when a patient’s breathing is stable and regular. Thus, the patient should be fully aware during respiratory pattern training before undergoing the RGRT treatment. In order to bypass the process of respiratory pattern training, we propose a target location prediction system for RGRT that uses only natural respiratory volume, and confirm its application. Methods: In order to verify the proposed target location prediction system, an in-house phantom set was used. This set involves a chest phantom including target, external markers, and motion generator. Natural respiratory volume signals were generated using the random function in MATLAB code. In the chest phantom, the target takes a linear motion based on the respiratory signal. After a four-dimensional computed tomography (4DCT) scan of the in-house phantom, the motion trajectory was derived as a linear equation. The accuracy of the linear equation was compared with that of the motion algorithm used by the operating motion generator. In addition, we attempted target location prediction using random respiratory volume values. Results: The correspondence rate of the linear equation derived from the 4DCT images with the motion algorithm of the motion generator was 99.41%. In addition, the average error rate of target location prediction was 1.23% for 26 cases. Conclusion: We confirmed the applicability of our proposed target location prediction system for RGRT using natural respiratory volume. If additional clinical studies can be conducted, a more accurate prediction system can be realized without requiring respiratory pattern training.

Accuracy evaluation of distance inverse square law in determining virtual electron source location in Siemens Primus linac.

Science.gov (United States)

Douk, Hamid Shafaei; Aghamiri, Mahmoud Reza; Ghorbani, Mahdi; Farhood, Bagher; Bakhshandeh, Mohsen; Hemmati, Hamid Reza

2018-01-01

The aim of this study is to evaluate the accuracy of the inverse square law (ISL) method for determining location of virtual electron source ( S Vir ) in Siemens Primus linac. So far, different experimental methods have presented for determining virtual and effective electron source location such as Full Width at Half Maximum (FWHM), Multiple Coulomb Scattering (MCS), and Multi Pinhole Camera (MPC) and Inverse Square Law (ISL) methods. Among these methods, Inverse Square Law is the most common used method. Firstly, Siemens Primus linac was simulated using MCNPX Monte Carlo code. Then, by using dose profiles obtained from the Monte Carlo simulations, the location of S Vir was calculated for 5, 7, 8, 10, 12 and 14 MeV electron energies and 10 cm × 10 cm, 15 cm × 15 cm, 20 cm × 20 cm and 25 cm × 25 cm field sizes. Additionally, the location of S Vir was obtained by the ISL method for the mentioned electron energies and field sizes. Finally, the values obtained by the ISL method were compared to the values resulted from Monte Carlo simulation. The findings indicate that the calculated S Vir values depend on beam energy and field size. For a specific energy, with increase of field size, the distance of S Vir increases for most cases. Furthermore, for a special applicator, with increase of electron energy, the distance of S Vir increases for most cases. The variation of S Vir values versus change of field size in a certain energy is more than the variation of S Vir values versus change of electron energy in a certain field size. According to the results, it is concluded that the ISL method can be considered as a good method for calculation of S Vir location in higher electron energies (14 MeV).

A General Overview of Natural Sources in Spain

International Nuclear Information System (INIS)

Poncela, L.S.Q.; Fernandez, C.S.; Merino, I.F.; Villanueva, J.L.G.

2011-01-01

Nationwide and regional surveys have been conducted to evaluate natural radiation exposure of the Spanish population. In these surveys, indoor radon, external gamma dose rates outdoors and indoors were measured. In the nationwide radon survey, 9% of the tested houses presented radon levels above 200 Bq/m 3 and 25% of houses with radon concentrations above this reference level were located in areas with high radon indoor levels. In 2010, the Radon Group in collaboration with two research groups from the University of Santiago de Compostela and University Autonoma de Barcelona has started the Radon 10 x 10 project which is bases on radon integrated measurements using track-etched detectors using grid 10 x 10 km 2 . In this work we present data measured during the last 30 years in Spain as well as some preliminary results of this new project

The nature of the EGRET source 3EG J1621+8203

International Nuclear Information System (INIS)

Mukherjee, R.; Stern, D.; Halpern, J.; Mirabal, N.; Gotthelf, E.V.

2001-01-01

We present broad-band observations of 3EG J1621+8203 in an effort to understand the nature of this source. We have examined X-ray images of the field from the ROSAT PSPC, ROSAT HRI, and ASCA GIS to search for a possible counterpart to the EGRET source. We find several faint X-ray point sources in the gamma-ray error circle. Preliminary analysis indicates that most of the point sources correspond to stars or to faint radio sources. Of the nearly 40% identified sources in the 3EG Catalog, the vast majority are blazars, but there is no blazer candidate in the error circle of 3EG J1621+8203. Of the notable objects in the EGRET error circle, one is the bright FR I radio galaxy NGC 6251 at a redshift of 0.0249. If NGC 6251 is the counterpart to the EGRET source 3EG J1621+8203, then it would be the second radio galaxy to be detected by EGRET. The first was Centaurus A. Cen A provided the first clear evidence of the detection above 100 MeV of an AGN with a large-inclination jet. If the identification with NGC 6251 is correct, the apparent gamma-ray luminosity of 3EG J1621+8203 is lower than that of other EGRET blazars; just as in the case of Cen A

Source contributions to PM2.5 and PM10 at an urban background and a street location

NARCIS (Netherlands)

Keuken, M. P.; Moerman, M.; Voogt, M.; Blom, M.; Weijers, E. P.; Rockmann, T.; Dusek, U.

The contribution of regional, urban and traffic sources to PM2.5 and PM10 in an urban area was investigated in this study. The chemical composition of PM2.5 and PM10 was measured over a year at a street location and up- and down-wind of the city of Rotterdam, the Netherlands. The C-14 content in EC

Source contributions to PM2.5 and PM10 at an urban background and a street location

NARCIS (Netherlands)

Keuken, M.P.; Moerman, M.M.; Voogt, M.H.

2013-01-01

The contribution of regional, urban and traffic sources to PM2.5 and PM10 in an urban area was investigated in this study. The chemical composition of PM2.5 and PM10 was measured over a year at a street location and up- and down-wind of the city of Rotterdam, the Netherlands. The 14C content in EC

Investigation of Seismic Waves from Non-Natural Sources: A Case Study for Building Collapse and Surface Explosion

Science.gov (United States)

Houng, S.; Hong, T.

2013-12-01

The nature and excitation mechanism of incidents or non-natural events have been widely investigated using seismological techniques. With introduction of dense seismic networks, small-sized non-natural events such as building collapse and chemical explosions are well recorded. Two representative non-natural seismic sources are investigated. A 5-story building in South Korea, Sampoong department store, was collapsed in June 25, 1995, causing casualty of 1445. This accident is known to be the second deadliest non-terror-related building collapse in the world. The event was well recorded by a local station in ~ 9 km away. P and S waves were recorded weak, while monotonic Rayleigh waves were observed well. The origin time is determined using surface-wave arrival time. The magnitude of event is determined to be 1.2, which coincides with a theoretical estimate based on the mass and volume of building. Synthetic waveforms are modeled for various combinations of velocity structures and source time functions, which allow us to constrain the process of building collapse. It appears that the building was collapsed once within a couple of seconds. We also investigate a M2.1 chemical explosion at a fertilizer plant in Texas on April 18, 2013. It was reported that more than one hundred people were dead or injured by the explosion. Seismic waveforms for nearby stations are collected from Incorporated Research Institution of Seismology (IRIS). The event was well recorded at stations in ~500 km away from the source. Strong acoustic signals were observed at stations in a certain great-circle direction. This observation suggests preferential propagation of acoustic waves depending on atmospheric environment. Waveform cross-correlation, spectral analysis and waveform modeling are applied to understand the source physics. We discuss the nature of source and source excitation mechanism.

Sources and levels of radioactivity in the Philippine environment

International Nuclear Information System (INIS)

Duran, E.B.; De Vera, C.M.; De la Cruz, F.M.; Enriquez, E.B.; Garcia, T.Y.; Palad, L.H.; Enriquez, S.O.; Eduardo, J.M.; Asada, A.A.

1996-01-01

Over the years, the Health Physics Research Section has assessed the sources and levels of radiation exposure in the Philippine environment. The data show that although Filipinos are exposed to both natural and artificial sources of environmental radioactivity, natural sources contribute much more significantly to the dose received by Filipinos than artificial sources. The average equivalent dose rate due to external sources of natural radiation in the Philippines is 45 μSv h -1 . Of this total dose rate, an average of 22 μSv h -1 is due to cosmic radiation while an average of 23 μSv h -1 is due to terrestrial radiation. External sources of natural radiation in the Philippines thus account for an annual per caput effective dose of about 400 μSv. In contrast, the annual per caput dose due to an artificial source, i.e., nuclear power production, was estimated by UNSCEAR (1988) to be only 0.6 μSv. Based on levels of background radioactivity due to external sources of natural radiation which were measured in 1600 locations, a radiation map of the country was developed. Among the internal sources of natural radiation, radon is the large contributor to dose and is considered as a serious indoor pollutant. Indoor radon levels in about 400 Filipino houses ranged from 1 to 63 Bq m -3 with a mean of 24 Bq m -3 . Significantly higher levels ranging from 30 to 347 Bq m -3 were observed in underground, non-uranium mines. Since there are no operational nuclear power plant in the Philippines, artificial radionuclides in the environment consist mainly of long-lived 137 Cs and 90 Sr from atmospheric nuclear weapons tests

Lattice Boltzmann analysis of effect of heating location and Rayleigh number on natural convection in partially heated open ended cavity

Energy Technology Data Exchange (ETDEWEB)

Gangawane, Krunal Madhukar; Bharti, Ram Prakash; Kumar, Surendra [Indian Institute of Technology Roorkee, Uttarakhand (India)

2015-08-15

Natural convection characteristics of a partially heated open ended square cavity have been investigated numerically by using an in-house computational flow solver based on the passive scalar thermal lattice Boltzmann method (PS-TLBM) with D2Q9 (two-dimensional and nine-velocity link) lattice model. The partial part of left wall of the cavity is heated isothermally at either of the three different (bottom, middle and top) locations for the fixed heating length as half of characteristic length (H/2) while the right wall is open to the ambient conditions. The other parts of the cavity are thermally isolated. In particular, the influences of partial heating locations and Rayleigh number (103≤ Ra≤106) in the laminar zone on the local and global natural convection characteristics (such as streamline, vorticity and isotherm contours; centerline variations of velocity and temperature; and local and average Nusselt numbers) have been presented and discussed for the fixed value of the Prandtl number (Pr=0.71). The streamline patterns show qualitatively similar nature for all the three heating cases and Rayleigh numbers, except the change in the recirculation zone which is found to be largest for middle heating case. Isotherm patterns are shifted towards a partially heated wall on increasing Rayleigh number and/or shifting of heating location from bottom to top. Both the local and average Nusselt numbers, as anticipated, shown proportional increase with Rayleigh number. The cavity with middle heating location shown higher heat transfer rate than that for the top and bottom heating cases. Finally, the functional dependence of the average Nusselt number on flow governing parameters is also presented as a closure relationship for the best possible utilization in engineering practices and design.

Synergistic microbial consortium for bioenergy generation from complex natural energy sources.

Science.gov (United States)

Wang, Victor Bochuan; Yam, Joey Kuok Hoong; Chua, Song-Lin; Zhang, Qichun; Cao, Bin; Chye, Joachim Loo Say; Yang, Liang

2014-01-01

Microbial species have evolved diverse mechanisms for utilization of complex carbon sources. Proper combination of targeted species can affect bioenergy production from natural waste products. Here, we established a stable microbial consortium with Escherichia coli and Shewanella oneidensis in microbial fuel cells (MFCs) to produce bioenergy from an abundant natural energy source, in the form of the sarcocarp harvested from coconuts. This component is mostly discarded as waste. However, through its usage as a feedstock for MFCs to produce useful energy in this study, the sarcocarp can be utilized meaningfully. The monospecies S. oneidensis system was able to generate bioenergy in a short experimental time frame while the monospecies E. coli system generated significantly less bioenergy. A combination of E. coli and S. oneidensis in the ratio of 1:9 (v:v) significantly enhanced the experimental time frame and magnitude of bioenergy generation. The synergistic effect is suggested to arise from E. coli and S. oneidensis utilizing different nutrients as electron donors and effect of flavins secreted by S. oneidensis. Confocal images confirmed the presence of biofilms and point towards their importance in generating bioenergy in MFCs.

The uranium source-term mineralogy and geochemistry at the Broubster natural analogue site, Caithness

International Nuclear Information System (INIS)

Milodowski, A.E.; Pearce, J.M.; Basham, I.R.; Hyslop, E.K.

1991-01-01

The British Geological Survey (BGS) has been conducting a coordinated research programme at the Broubster natural analogue site in Caithness, north Scotland. This work on a natural radioactive geochemical system has been carried out with the aim of improving our confidence in using predictive models of radionuclide migration in the geosphere. This report is one of a series being produced and it concentrates on the mineralogical characterization of the uranium distribution in the limestone unit considered as the 'source-term' in the natural analogue model

Preprocessor with spline interpolation for converting stereolithography into cutter location source data

Science.gov (United States)

Nagata, Fusaomi; Okada, Yudai; Sakamoto, Tatsuhiko; Kusano, Takamasa; Habib, Maki K.; Watanabe, Keigo

2017-06-01

The authors have developed earlier an industrial machining robotic system for foamed polystyrene materials. The developed robotic CAM system provided a simple and effective interface without the need to use any robot language between operators and the machining robot. In this paper, a preprocessor for generating Cutter Location Source data (CLS data) from Stereolithography (STL data) is first proposed for robotic machining. The preprocessor enables to control the machining robot directly using STL data without using any commercially provided CAM system. The STL deals with a triangular representation for a curved surface geometry. The preprocessor allows machining robots to be controlled through a zigzag or spiral path directly calculated from STL data. Then, a smart spline interpolation method is proposed and implemented for smoothing coarse CLS data. The effectiveness and potential of the developed approaches are demonstrated through experiments on actual machining and interpolation.

Sources and Nature of Secondary School Teachers' Education in Computer-Related Ergonomics

Science.gov (United States)

Dockrell, Sara; Fallon, Enda; Kelly, Martina; Galvin, Rose

2009-01-01

Teachers' knowledge of computer-related ergonomics in education will have an effect on the learning process and the work practices of their students. However little is known about teacher education in this area. The study aimed to investigate the sources and nature of secondary school teachers' education about computer-related ergonomics. It also…

Bootstrap inversion technique for atmospheric trace gas source detection and quantification using long open-path laser measurements

Science.gov (United States)

Alden, Caroline B.; Ghosh, Subhomoy; Coburn, Sean; Sweeney, Colm; Karion, Anna; Wright, Robert; Coddington, Ian; Rieker, Gregory B.; Prasad, Kuldeep

2018-03-01

Advances in natural gas extraction technology have led to increased activity in the production and transport sectors in the United States and, as a consequence, an increased need for reliable monitoring of methane leaks to the atmosphere. We present a statistical methodology in combination with an observing system for the detection and attribution of fugitive emissions of methane from distributed potential source location landscapes such as natural gas production sites. We measure long (> 500 m), integrated open-path concentrations of atmospheric methane using a dual frequency comb spectrometer and combine measurements with an atmospheric transport model to infer leak locations and strengths using a novel statistical method, the non-zero minimum bootstrap (NZMB). The new statistical method allows us to determine whether the empirical distribution of possible source strengths for a given location excludes zero. Using this information, we identify leaking source locations (i.e., natural gas wells) through rejection of the null hypothesis that the source is not leaking. The method is tested with a series of synthetic data inversions with varying measurement density and varying levels of model-data mismatch. It is also tested with field observations of (1) a non-leaking source location and (2) a source location where a controlled emission of 3.1 × 10-5 kg s-1 of methane gas is released over a period of several hours. This series of synthetic data tests and outdoor field observations using a controlled methane release demonstrates the viability of the approach for the detection and sizing of very small leaks of methane across large distances (4+ km2 in synthetic tests). The field tests demonstrate the ability to attribute small atmospheric enhancements of 17 ppb to the emitting source location against a background of combined atmospheric (e.g., background methane variability) and measurement uncertainty of 5 ppb (1σ), when measurements are averaged over 2 min. The

Western Pacific liquefied natural gas

International Nuclear Information System (INIS)

Woronuk, R.

2004-01-01

WestPac Terminals Inc. has expertise in natural gas supply and demand, transportation, liquefied natural gas (LNG) and economic optimization. This presentation addressed issues facing their proposed construction of an LNG terminal and associated facilities on the west coast of Canada. It presented pie charts comparing world gas reserves with production. NPC gas price projects and WestPac gas cost estimates were also presented. It was noted that an unprecedented growth in LNG imports to North America is essential and that LNG will be the lowest price major source of natural gas supply. Maps illustrating LNG sources and receiving terminals were also presented along with solutions to the not-in-my-back-yard (NIMBY) syndrome. Solutions include selecting locations where communities are pro-development, where LNG terminals can provide direct financial benefits to the community, and using existing infrastructure to minimize socio-economic impacts. The advantages of developing LNG to Prince Rupert were discussed in terms of serving energy markets, direct provincial benefits, and LNG/power generation synergies. figs

Tree Coring as a Complement to Soil Gas Screening to Locate PCE and TCE Source Zones and Hot Spots

DEFF Research Database (Denmark)

Nielsen, Mette Algreen; Trapp, Stefan; Rehne Jensen, Pernille

2015-01-01

) or trichloroethylene (TCE) to evaluate their ability to locate source zones and contaminant hot spots. One test site represented a relatively homogeneous sandy soil and aquifer, and the second a more heterogeneous geology with both sandy and less permeable clay till layers overlying a chalk aquifer. Tree cores from...

Mercury emissions to the atmosphere from natural and anthropogenic sources in the Mediterranean region

Science.gov (United States)

Pirrone, N.; Costa, P.; Pacyna, J. M.; Ferrara, R.

This report discusses past, current and projected mercury emissions to the atmosphere from major industrial sources, and presents a first assessment of the contribution to the regional mercury budget from selected natural sources. Emissions (1995 estimates) from fossil fuels combustion (29.8 t yr -1) , cement production (28.8 t yr -1) and incineration of solid wastes (27.6 t yr -1) , all together account for about 82% of the regional anthropogenic total (105.7 t yr -1) . Other industrial sources in the region are smelters (4.8 t yr -1) , iron-steel plants (4.8 t yr -1) and other minor sources (chlor-alkali plants, crematoria, chemicals production) that have been considered together in the miscellaneous category (9.6 t yr -1) . Regional emissions from anthropogenic sources increased at a rate of 3% yr-1 from 1983 to 1995 and are projected to increase at a rate of 1.9% yr-1 in the next 25 years, if no improvement in emission control policy occurs. On a country-by-country basis, France is the leading emitter country with 22.6 t yr -1 followed by Turkey (16.1 t yr -1) , Italy (11.4 t yr -1) , Spain (9.1 t yr -1) , the former Yugoslavia 7.9 ( t yr -1) , Morocco (6.9 t yr -1) , Bulgaria (6.8 t yr -1) , Egypt (6.1 t yr -1) , Syria (3.6 t yr -1) , Libya (2.9 t yr -1) , Tunisia (2.8 t yr -1) and Greece (2.7 t yr -1) , whereas the remaining countries account for less than 7% of the regional total. The annual emission from natural sources is 110 t yr -1, although this figure only includes the volatilisation of elemental mercury from surface waters and emissions from volcanoes, whereas the contribution due to the degassing of mercury from top soil and vegetation has not been included in this first assessment. Therefore, natural and anthropogenic sources in the Mediterranean region release annually about 215 t of mercury, which represents a significant contribution to the total mercury budget released in Europe and to the global atmosphere.

Using hydrogeology to identify the source of groundwater to Montezuma Well, a natural spring in central Arizona: part 1

Science.gov (United States)

Johnson, Raymond H.; DeWitt, Ed H.; Arnold, L. Rick

2012-01-01

Montezuma Well is a natural spring located within a “sinkhole” in the desert environment of the Verde Valley in Central Arizona. It is managed by the National Park Service as part of Montezuma Castle National Monument. Because of increasing development of groundwater in the area, this research was undertaken to better understand the sources of groundwater to Montezuma Well. The use of well logs and geophysics provides details on the geology in the area around Montezuma Well. This includes characterizing the extent and position of a basalt dike that intruded a deep fracture zone. This low permeability barrier forces groundwater to the surface at the Montezuma Well “pool” with sufficient velocity to entrain sand-sized particles from underlying bedrock. Permeable fractures along and above the basalt dike provide conduits that carry deep sourced carbon dioxide to the surface, which can dissolve carbonate minerals along the transport path in response to the added carbon dioxide. At the ground surface, CO2 degasses, depositing travertine. Geologic cross sections, rock geochemistry, and semi-quantitative groundwater flow modeling provide a hydrogeologic framework that indicates groundwater flow through a karstic limestone at depth (Redwall Limestone) as the most significant source of groundwater to Montezuma Well. Additional groundwater flow from the overlying formations (Verde Formation and Permian Sandstones) is a possibility, but significant flow from these units is not indicated.

Effects of heater location and heater size on the natural convection heat transfer in a square cavity using finite element method

Energy Technology Data Exchange (ETDEWEB)

Ngo, Ich Long; Byon, Chan [Yeungnam University, Gyeongsan (Korea, Republic of)

2015-07-15

Finite element method was used to investigate the effects of heater location and heater size on the natural convection heat transfer in a 2D square cavity heated partially or fully from below and cooled from above. Rayleigh number (5 X 10{sup 2} ≤ Ra ≤ 5X10{sup 5}), heater size (0.1 ≤ D/L ≤ 1.0), and heater location (0.1 ≤ x{sub h}/L ≤ 0.5) were considered. Numerical results indicated that the average Nusselt number (Nu{sub m}) increases as the heater size decreases. In addition, when x{sub h}/L is less than 0.4, Nu{sub m} increases as x{sub h}/L increases, and Num decreases again for a larger value of x{sub h}/L. However, this trend changes when Ra is less than 10{sup 4}, suggesting that Nu{sub m} attains its maximum value at the region close to the bottom surface center. This study aims to gain insight into the behaviors of natural convection in order to potentially improve internal natural convection heat transfer.

Long-term dust aerosol production from natural sources in Iceland.

Science.gov (United States)

Dagsson-Waldhauserova, Pavla; Arnalds, Olafur; Olafsson, Haraldur

2017-02-01

Iceland is a volcanic island in the North Atlantic Ocean with maritime climate. In spite of moist climate, large areas are with limited vegetation cover where >40% of Iceland is classified with considerable to very severe erosion and 21% of Iceland is volcanic sandy deserts. Not only do natural emissions from these sources influenced by strong winds affect regional air quality in Iceland ("Reykjavik haze"), but dust particles are transported over the Atlantic ocean and Arctic Ocean >1000 km at times. The aim of this paper is to place Icelandic dust production area into international perspective, present long-term frequency of dust storm events in northeast Iceland, and estimate dust aerosol concentrations during reported dust events. Meteorological observations with dust presence codes and related visibility were used to identify the frequency and the long-term changes in dust production in northeast Iceland. There were annually 16.4 days on average with reported dust observations on weather stations within the northeastern erosion area, indicating extreme dust plume activity and erosion within the northeastern deserts, even though the area is covered with snow during the major part of winter. During the 2000s the highest occurrence of dust events in six decades was reported. We have measured saltation and Aeolian transport during dust/volcanic ash storms in Iceland, which give some of the most intense wind erosion events ever measured. Icelandic dust affects the ecosystems over much of Iceland and causes regional haze. It is likely to affect the ecosystems of the oceans around Iceland, and it brings dust that lowers the albedo of the Icelandic glaciers, increasing melt-off due to global warming. The study indicates that Icelandic dust may contribute to the Arctic air pollution. Long-term records of meteorological dust observations from Northeast Iceland indicate the frequency of dust events from Icelandic deserts. The research involves a 60-year period and

Investigation Of The Origin Of Various Water Sources In The Vicinity Of Ngancar Dam, Wonogiri Using Natural Isotopes

International Nuclear Information System (INIS)

Sidauruk, Paston; Indrojoyo; Wibagoyo; Pratikno, Bungkus; Evarista Ristin, P.I.

2000-01-01

The investigation of the origin of various water sources in the vicinity of Ngancar Dam, Wonogiri, using natural isotopes technique has been conducted. The study includes collecting and analyzing water samples from various sources in the vicinity of the dam such as reservoir water, water discharges, springs, local water well, rain water, water from piezometer and observation wells. For this investigation, natural isotopes composition and hydro chemical ions of the samples have been analyzed and interpreted. From the data interpretation, it is concluded that most of the water in various sources originated from water reservoir

Investigation Of The Natural Radioactivity In The Phuoc Dinh Area Located In The Thuan Nam District, Ninh Thuan Province

International Nuclear Information System (INIS)

Ba Van Khoi; Vo Xuan An

2011-01-01

It is very important that the natural radioactivity in the Phuoc Dinh area located in the Thuan Nam district, Ninh Thuan province has to be investigated. Because Phuoc Dinh is an area anticipated for constructing The 1 st Ninh Thuan Nuclear Power Plant, the data of the natural radioactivity determined before installing and operating this Nuclear Power Plant are to evaluate the dangerous ecologic effects of this industry. The soil samples were collected in the radius of 0.5, 0.6 and 0.7 km from the fence of this Nuclear Power Plant. The results of the natural radioactivity were measured on the low background spectrometry using the high purity germanium (HPGe) detector at the Center for Nuclear Techniques Ho Chi Minh City. (author)

Harmonic disturbance location by applying Bayesian inference

NARCIS (Netherlands)

Ye, G.; Xiang, Y.; Cuk, V.; Cobben, J.F.G.

2016-01-01

Harmonic pollution is one of the most important power quality issues in electric power systems. Correct location of the main harmonic disturbance source is a key step to solve the problem. This paper presents a method to detect the location of harmonic disturbance source in low voltage network

Bounds in the location-allocation problem

DEFF Research Database (Denmark)

Juel, Henrik

1981-01-01

Develops a family of stronger lower bounds on the objective function value of the location-allocation problem. Solution methods proposed to solve problems in location-allocation; Efforts to develop a more efficient bound solution procedure; Determination of the locations of the sources....

Assessment of environmental gamma radiation levels at locations having different source characteristics using TLDs

International Nuclear Information System (INIS)

Sahu, S.K.; Swarnkar, M.; Takale, R.A.; Shetty, P.G.; Pandit, G.G.; Puranik, V.D.

2012-01-01

Naturally occurring radionuclides are the major contributor to the total effective dose of ionizing radiation received by the population (UNSCEAR, 1993). The dose in environment thus depends largely on natural radiation than manmade or artificially produced radiation. In the last few decades, there is a growing concern all over the world about radiation and their exposure to population. Thus, it is a necessity to conduct frequent radiological environmental surveillance in order to assess population exposure accurately. Recently, application of thermoluminescence dosimeters (TLDs) has been extended to the measurement of mixed radiation field as encountered in the environment. The advantages of passive TL dosimeters for environmental monitoring are that they are small, cheap and do not require power supply during application. The passive TL dosimeters play an important role to provide data on natural background radiation and to determine the contribution to the dose to public from man-made sources. In the present study, three different sites were chosen to compare environmental gamma radiation levels in different scenarios. Kaiga has been chosen as site 1, where four unit of pressurized heavy water reactor (PHWR) of 220 MWe each are in operation. Site 2 is chosen at natural high background radiation area (NHBRA) of Kerala and Vishakhapatnam was chosen as site 3, which is situated at a normal background area. The objective of the study is to illustrate the effect, if any, of an operating nuclear power reactor on environmental gamma radiation levels

Nature of suspended particulate matter and concentrations of heavy ...

African Journals Online (AJOL)

The concentrations of metals in bottom sediment in the Tanzanian waters of Lake Victoria and the nature of suspended particulate matter (SPM) were analysed. The objective of the study was to compare levels of metals in sediment from different locations and to establish their sources. Metal concentrations were higher in ...

Profiling oil sands mixtures from industrial developments and natural groundwaters for source identification.

Science.gov (United States)

Frank, Richard A; Roy, James W; Bickerton, Greg; Rowland, Steve J; Headley, John V; Scarlett, Alan G; West, Charles E; Peru, Kerry M; Parrott, Joanne L; Conly, F Malcolm; Hewitt, L Mark

2014-01-01

The objective of this study was to identify chemical components that could distinguish chemical mixtures in oil sands process-affected water (OSPW) that had potentially migrated to groundwater in the oil sands development area of northern Alberta, Canada. In the first part of the study, OSPW samples from two different tailings ponds and a broad range of natural groundwater samples were assessed with historically employed techniques as Level-1 analyses, including geochemistry, total concentrations of naphthenic acids (NAs) and synchronous fluorescence spectroscopy (SFS). While these analyses did not allow for reliable source differentiation, they did identify samples containing significant concentrations of oil sands acid-extractable organics (AEOs). In applying Level-2 profiling analyses using electrospray ionization high resolution mass spectrometry (ESI-HRMS) and comprehensive multidimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF/MS) to samples containing appreciable AEO concentrations, differentiation of natural from OSPW sources was apparent through measurements of O2:O4 ion class ratios (ESI-HRMS) and diagnostic ions for two families of suspected monoaromatic acids (GC × GC-TOF/MS). The resemblance between the AEO profiles from OSPW and from 6 groundwater samples adjacent to two tailings ponds implies a common source, supporting the use of these complimentary analyses for source identification. These samples included two of upward flowing groundwater collected <1 m beneath the Athabasca River, suggesting OSPW-affected groundwater is reaching the river system.

Changes in abundance and nature of microimpact craters on the surfaces of Australasian microtektites with distance from the proposed source crater location

Digital Repository Service at National Institute of Oceanography (India)

ShyamPrasad, M.; Roy, S.K.; Gupta, A.

of the craters are of erosive type (Fig. 2), i.e., those which contain a central pit which is surrounded by radial and concentric cracks, indicative of high velocity impacts (Hörz et al., 1971). This could be misleading, as observed in our earlier studies... of very small particles at high relative velocities. This location also has 9    the highest spatial density of impacts, i.e., it contains 230 micro-craters/cm 2 of the ocean floor (Table 2). AAS 22/8 (4052 km): Location : 07 0 05.289’S & 78 0...

Anthropogenic and natural sources of acidity and metals and their influence on the structure of stream food webs

International Nuclear Information System (INIS)

Hogsden, Kristy L.; Harding, Jon S.

2012-01-01

We compared food web structure in 20 streams with either anthropogenic or natural sources of acidity and metals or circumneutral water chemistry in New Zealand. Community and diet analysis indicated that mining streams receiving anthropogenic inputs of acidic and metal-rich drainage had much simpler food webs (fewer species, shorter food chains, less links) than those in naturally acidic, naturally high metal, and circumneutral streams. Food webs of naturally high metal streams were structurally similar to those in mining streams, lacking fish predators and having few species. Whereas, webs in naturally acidic streams differed very little from those in circumneutral streams due to strong similarities in community composition and diets of secondary and top consumers. The combined negative effects of acidity and metals on stream food webs are clear. However, elevated metal concentrations, regardless of source, appear to play a more important role than acidity in driving food web structure. - Highlights: ► Food webs in acid mine drainage impacted streams are small and extremely simplified. ► Conductivity explained differences in food web properties between streams. ► Number of links and web size accounted for much dissimilarity between food webs. ► Food web structure was comparable in naturally acidic and circumneutral streams. - Food web structure differs in streams with anthropogenic and natural sources of acidity and metals.

Location condition of nuclear power generation at a viewpoint of location area

International Nuclear Information System (INIS)

Kawase, Kazuharu

1999-01-01

In the thirty years memorial meeting of the National Nuclear Power Generation located Commune Conference (NNGC) held in October, 1998, an extremely important fact was clarified, relation deeply to main aim of NNGC that permanent development was not promised at the location area even if a nuclear power plant was constructed there. Therefore, it is required that Japan government receives operation of three laws on electric source development as soon as possible, establishes a basic target on permanent area promotion in the nuclear power generation located commune, realizes some examples on development of the commune together with nuclear power generation and intends to promoted its location. (G.K.)

Imaging near-surface heterogeneities by natural migration of backscattered surface waves

KAUST Repository

AlTheyab, Abdullah

2016-02-01

We present a migration method that does not require a velocity model to migrate backscattered surface waves to their projected locations on the surface. This migration method, denoted as natural migration, uses recorded Green\\'s functions along the surface instead of simulated Green\\'s functions. The key assumptions are that the scattering bodies are within the depth interrogated by the surface waves, and the Green\\'s functions are recorded with dense receiver sampling along the free surface. This natural migration takes into account all orders of multiples, mode conversions and non-linear effects of surface waves in the data. The natural imaging formulae are derived for both active source and ambient-noise data, and computer simulations show that natural migration can effectively image near-surface heterogeneities with typical ambient-noise sources and geophone distributions.

HPSLPred: An Ensemble Multi-Label Classifier for Human Protein Subcellular Location Prediction with Imbalanced Source.

Science.gov (United States)

Wan, Shixiang; Duan, Yucong; Zou, Quan

2017-09-01

Predicting the subcellular localization of proteins is an important and challenging problem. Traditional experimental approaches are often expensive and time-consuming. Consequently, a growing number of research efforts employ a series of machine learning approaches to predict the subcellular location of proteins. There are two main challenges among the state-of-the-art prediction methods. First, most of the existing techniques are designed to deal with multi-class rather than multi-label classification, which ignores connections between multiple labels. In reality, multiple locations of particular proteins imply that there are vital and unique biological significances that deserve special focus and cannot be ignored. Second, techniques for handling imbalanced data in multi-label classification problems are necessary, but never employed. For solving these two issues, we have developed an ensemble multi-label classifier called HPSLPred, which can be applied for multi-label classification with an imbalanced protein source. For convenience, a user-friendly webserver has been established at http://server.malab.cn/HPSLPred. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isolation and characterization of (15Z)-lycopene thermally generated from a natural source

Energy Technology Data Exchange (ETDEWEB)

Takehara, Munenori, E-mail: takehara@mat.usp.ac.jp [Department of Materials Science, The University of Shiga Prefecture, Hassaka, Hikone 522-8533 (Japan); Kuwa, Takahiro; Inoue, Yoshinori; Kitamura, Chitoshi [Department of Materials Science, The University of Shiga Prefecture, Hassaka, Hikone 522-8533 (Japan); Honda, Masaki [Research & Development Division, Kagome Co., Ltd., Nishitomiyama, Nasushiobara 329-2762 (Japan)

2015-11-06

(15Z)-Lycopene was prepared by thermal isomerization of (all-E)-lycopene derived from tomatoes, and isolated by using a series of chromatographies. The fine red crystalline powder of (15Z)-lycopene was obtained from 556 mg of (all-E)-lycopene with a yield of 0.6 mg (purity: reversed-phase HPLC, 97.2%; normal-phase HPLC, ≥99.9%), and {sup 1}H and {sup 13}C NMR spectra of the isomer were fully assigned. More refined computational analyses that considered differences in the energy levels of the conformers involved in isomerization have also determined the stabilities of (15Z)-lycopene and other geometric isomers, along with the activation energies during isomerization from the all-E form. The fine control of conditions for HPLC separation and an advanced theoretical insight into geometric isomerization have led to the discovery of the 15Z-isomer generated from a natural source. - Highlights: • (15Z)-lycopene, isomerized from the all-E form of a natural source, was purified. • The obtained (15Z)-lycopene was structurally identified by an NMR analysis. • A modified theoretical study accounted for the generation of the 15Z-isomer. • This study demonstrated the occurrence of the isomer from a natural origin.

Isolation and characterization of (15Z)-lycopene thermally generated from a natural source

International Nuclear Information System (INIS)

Takehara, Munenori; Kuwa, Takahiro; Inoue, Yoshinori; Kitamura, Chitoshi; Honda, Masaki

2015-01-01

(15Z)-Lycopene was prepared by thermal isomerization of (all-E)-lycopene derived from tomatoes, and isolated by using a series of chromatographies. The fine red crystalline powder of (15Z)-lycopene was obtained from 556 mg of (all-E)-lycopene with a yield of 0.6 mg (purity: reversed-phase HPLC, 97.2%; normal-phase HPLC, ≥99.9%), and 1 H and 13 C NMR spectra of the isomer were fully assigned. More refined computational analyses that considered differences in the energy levels of the conformers involved in isomerization have also determined the stabilities of (15Z)-lycopene and other geometric isomers, along with the activation energies during isomerization from the all-E form. The fine control of conditions for HPLC separation and an advanced theoretical insight into geometric isomerization have led to the discovery of the 15Z-isomer generated from a natural source. - Highlights: • (15Z)-lycopene, isomerized from the all-E form of a natural source, was purified. • The obtained (15Z)-lycopene was structurally identified by an NMR analysis. • A modified theoretical study accounted for the generation of the 15Z-isomer. • This study demonstrated the occurrence of the isomer from a natural origin.

Western Pacific liquefied natural gas

International Nuclear Information System (INIS)

Woronuk, R.

2005-01-01

This presentation addressed issues facing WestPac Terminals' proposed construction of a liquefied natural gas (LNG) terminal and associated facilities on the Ridley Island on the coast of British Columbia. WestPac Terminals Inc. has expertise in natural gas supply and demand, transportation, LNG and economic optimization. Although a review of proposals for receiving terminals in North America has demonstrated the urgency and attractiveness of LNG imports, west coast terminals are not proceeding, largely due to lack of support by local communities. WestPac's proposal includes a deep enough port to accommodate the largest LNG tankers; a port en route to west coast terminal locations to serve as a transshipment hub; sufficient space for LNG storage tanks and natural gas liquids extraction; sea, rail, air and highway access. Other solutions include selecting locations where communities are pro-development where LNG terminals can provide direct financial benefits to the community, and using existing infrastructure to minimize socio-economic impacts. The advantages of developing LNG at the proposed site were discussed in terms of serving energy markets and provincial benefits. LNG source and cost issues were reviewed along with existing markets and required infrastructure for LNG market development. tabs., figs

Two Simon tasks with different sources of conflict: an ERP study of motion- and location-based compatibility effects.

Science.gov (United States)

Galashan, Daniela; Wittfoth, Matthias; Fehr, Thorsten; Herrmann, Manfred

2008-07-01

Behavioral and electrophysiological correlates of two Simon tasks were examined using comparable stimuli but different task-irrelevant and conflict-inducing stimulus features. Whereas target shape was always the task-relevant stimulus attribute, either target location (location-based task) or motion direction within the target stimuli (motion-based task) was used as a source of conflict. Data from ten healthy participants who performed both tasks are presented. In the motion-based task the incompatible condition showed smaller P300 amplitudes at Pz than the compatible condition and the location-based task yielded a trend towards a reduced P300 amplitude in the incompatible condition. For both tasks, no P300 latency differences between the conditions were found at Pz. The results suggest that the motion-based task elicits behavioral and electrophysiological effects comparable with regular Simon tasks. As all stimuli in the motion-based Simon task were presented centrally the present data strongly argue against the attention-shifting account as an explanatory approach.

Comparison of small mammal species diversity near wastewater outfalls, natural streams, and dry canyons

International Nuclear Information System (INIS)

Raymer, D.F.; Biggs, J.R.

1994-03-01

A wide range of plant and wildlife species utilizes water discharged from facilities at Los Alamos National Laboratory (LANL). The purpose of this study was to compare nocturnal small mammal communities at wet areas created by wastewater outfalls with communities in naturally created wet and dry areas. Thirteen locations within LANL boundaries were selected for small mammal mark-recapture trapping. Three of these locations lacked surface water sources and were classified as open-quotes dry,close quotes while seven sites were associated with wastewater outfalls (open-quotes outfallclose quotes sites), and three were located near natural sources of surface water (open-quotes naturalclose quotes sites). Data was collected on site type (dry, outfall or natural), location, species trapped, and the tag number of each individual captured. This data was used to calculate mean number of species, percent capture rate, and species diversity at each type of site. When data from each type of site was pooled, there were no significant differences in these variables between dry, outfall, and natural types. However, when data from individual sites was compared, tests revealed significant differences. All sites in natural areas were significantly higher than dry areas in daily mean number of species, percent capture rate, and species diversity. Most outfall sites were significantly higher than dry areas in all three variables tested. When volume of water from each outfall site was considered, these data indicated that the number of species, percent capture rate, and species diversity of nocturnal small mammals were directly related to the volume of water at a given outfall

Exposure of the Spanish population to radiation from natural sources

International Nuclear Information System (INIS)

Garcia-Talavera, M.; Suarez, E.; Matarranz, J.L.; Salas, R.; Ramos, L.

2006-01-01

We have assessed the exposure of the Spanish population to natural radiation sources. The annual average effective dose is estimated to be 2.38 mSv, taking into account contributions from cosmic radiation (13.8%), terrestrial gamma radiation (39%), radon and thoron inhalation (34%) and ingestion (13.2%). Cosmic radiation doses were calculated from town altitude data. Terrestrial gamma ray exposure outdoors was derived from the M.A.R.N.A. (natural gamma radiation map of Spain). Indoor gamma ray exposure was calculated by multiplying the corresponding outdoor value by a conversion factor, which was obtained by a linear least-squares fit of experimental measurements. Radon doses were estimated from national surveys carried out throughout the country. To assess doses by ingestion of water and foodstuffs we considered the results from a detailed study on consumption habits by age and geographical area in Spain, promoted by C.S.N., and average radioactivity values from UNSCEAR. (authors)

Exposure of the Spanish population to radiation from natural sources

Energy Technology Data Exchange (ETDEWEB)

Garcia-Talavera, M.; Suarez, E.; Matarranz, J.L.; Salas, R.; Ramos, L. [Consejo de Seguridad Nuclear. Justo Dorado, Madrid (Spain)

2006-07-01

We have assessed the exposure of the Spanish population to natural radiation sources. The annual average effective dose is estimated to be 2.38 mSv, taking into account contributions from cosmic radiation (13.8%), terrestrial gamma radiation (39%), radon and thoron inhalation (34%) and ingestion (13.2%). Cosmic radiation doses were calculated from town altitude data. Terrestrial gamma ray exposure outdoors was derived from the M.A.R.N.A. (natural gamma radiation map of Spain). Indoor gamma ray exposure was calculated by multiplying the corresponding outdoor value conversion factor, which was obtained by a linear least-squares fit of experimental measurements. Radon doses were estimated from national surveys carried out throughout the country. To assess doses by ingestion of water and foodstuffs we considered the results from a detailed study on consumption habits by age and geographical area in Spain, promoted by C.S.N., and average radioactivity values from UNSCEAR. (authors)

A method for detection and location of high resistance earth faults

Energy Technology Data Exchange (ETDEWEB)

Haenninen, S; Lehtonen, M [VTT Energy, Espoo (Finland); Antila, E [ABB Transmit Oy (Finland)

1998-08-01

In the first part of this presentation, the theory of earth faults in unearthed and compensated power systems is briefly presented. The main factors affecting the high resistance fault detection are outlined and common practices for earth fault protection in present systems are summarized. The algorithms of the new method for high resistance fault detection and location are then presented. These are based on the change of neutral voltage and zero sequence currents, measured at the high voltage / medium voltage substation and also at the distribution line locations. The performance of the method is analyzed, and the possible error sources discussed. Among these are, for instance, switching actions, thunder storms and heavy snow fall. The feasibility of the method is then verified by an analysis based both on simulated data, which was derived using an EMTP-ATP simulator, and by real system data recorded during field tests at three substations. For the error source analysis, some real case data recorded during natural power system events, is also used

The location and nature of the Telemzan High Ghadames basin boundary in southern Tunisia based on gravity and magnetic anomalies

Science.gov (United States)

Gabtni, H.; Jallouli, C.; Mickus, K. L.; Zouari, H.; Turki, M. M.

2006-03-01

Gravity and magnetic data were analyzed to add constraints on the location and nature of the Telemzan-Ghadames boundary (TGB) and structure of the Ghadames basin in southern Tunisia. TGB is the boundary between the thick sedimentary cover of the intracratonic Ghadames basin to the south and the thin sedimentary cover of the Saharan platform to the north. The upward continuation of the Bouguer gravity anomalies showed that the TGB is a regional geophysical feature that may have controlled the amount of sediment being deposited both north and south of the boundary and the tectonic environment in the region since Paleozoic time. To emphasize the shorter wavelength gravity and magnetic anomalies, a series of gray scale images of the directional horizontal gradients were constructed that determined a series of previously unknown east-west-trending gravity and magnetic anomalies south of 31.6°N that correspond to lineaments seen on a Landsat 7 image and the location of the TGB. Also, an edge-enhancement analysis illustrated the same linear gravity anomalies and showed the subbasins and uplifts within the Ghadames basin had source depths of between 0.5 and 3.4 km. A north-south trending gravity model showed that the TGB is a relatively gradual feature (possibly basement stepped down by relatively low-displacement faulting) controlling the subsidence of the main Ghadames basin and confirms the edge-enhancement analysis that subbasin S3 and uplift U1 are the main structural features within the Ghadames basin. The knowledge of basement architecture of the Ghadames basin is important for future petroleum exploration within this intracratonic basin.

Sources of Caffeine in Diets of US Children and Adults: Trends by Beverage Type and Purchase Location

OpenAIRE

Adam Drewnowski; Colin D. Rehm

2016-01-01

New sources of caffeine, besides coffee and tea, have been introduced into the US food supply. Data on caffeine consumption age and purchase location can help guide public health policy. National Health and Nutrition Examination Surveys (NHANES) were used to estimate population-level caffeine intakes, using data from 24-h dietary recall. First, caffeine intakes by age-group and beverage type were estimated using the most recent 2011?2012 data (n = 7456). Second, fourteen years trends in caffe...

Compound-Specific Isotope Analysis (CSIA Application for Source Apportionment and Natural Attenuation Assessment of Chlorinated Benzenes

Directory of Open Access Journals (Sweden)

Luca Alberti

2017-11-01

Full Text Available In light of the complex management of chlorobenzene (CB contaminated sites, at which a hydraulic barrier (HB for plumes containment is emplaced, compound-specific stable isotope analysis (CSIA has been applied for source apportionment, for investigating the relation between the upgradient and downgradient of the HB, and to target potential CB biodegradation processes. The isotope signature of all the components potentially involved in the degradation processes has been expressed using the concentration-weighted average δ13C of CBs + benzene (δ13Csum. Upgradient of the HB, the average δ13Csum of −25.6‰ and −29.4‰ were measured for plumes within the eastern and western sectors, respectively. Similar values were observed for the potential sources, with δ13Csum values of −26.5‰ for contaminated soils and −29.8‰ for the processing water pipeline in the eastern and western sectors, respectively, allowing for apportioning of these potential sources to the respective contaminant plumes. For the downgradient of the HB, similar CB concentrations but enriched δ13Csum values between −24.5‰ and −25.9‰ were measured. Moreover, contaminated soils showed a similar δ13Csum signature of −24.5‰, thus suggesting that the plumes likely originate from past activities located in the downgradient of the HB. Within the industrial property, significant δ13C enrichments were measured for 1,2,4-trichlorobenzene (TCB, 1,2-dichlorobenzene (DCB, 1,3-DCB, and 1,4-DCBs, thus suggesting an important role for anaerobic biodegradation. Further degradation of monochlorobenzene (MCB and benzene was also demonstrated. CSIA was confirmed to be an effective approach for site characterization, revealing the proper functioning of the HB and demonstrating the important role of natural attenuation processes in reducing the contamination upgradient of the HB.

Revealing transboundary and local air pollutant sources affecting Metro Manila through receptor modeling studies

International Nuclear Information System (INIS)

Pabroa, Preciosa Corazon B.; Bautista VII, Angel T.; Santos, Flora L.; Racho, Joseph Michael D.

2011-01-01

Ambient fine particulate matter (PM 2 .5) levels at the Metro Manila air sampling stations of the Philippine Nuclear Research Research Institute were found to be above the WHO guideline value of 10 μg m 3 indicating, in general, very poor air quality in the area. The elemental components of the fine particulate matter were obtained using the energy-dispersive x-ray fluorescence spectrometry. Positive matrix factorization, a receptor modelling tool, was used to identify and apportion air pollution sources. Location of probable transboundary air pollutants were evaluated using HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory Model) while location of probable local air pollutant sources were determined using the conditional probability function (CPF). Air pollutant sources can either be natural or anthropogenic. This study has shown natural air pollutant sources such as volcanic eruptions from Bulusan volcano in 2006 and from Anatahan volcano in 2005 to have impacted on the region. Fine soils was shown to have originated from China's Mu US Desert some time in 2004. Smoke in the fine fraction in 2006 show indications of coming from forest fires in Sumatra and Borneo. Fine particulate Pb in Valenzuela was shown to be coming from the surrounding area. Many more significant air pollution impacts can be evaluated with the identification of probable air pollutant sources with the use of elemental fingerprints and locating these sources with the use of HYSPLIT and CPF. (author)

Electrophysiological correlates of predictive coding of auditory location in the perception of natural audiovisual events

Directory of Open Access Journals (Sweden)

Jeroen eStekelenburg

2012-05-01

Full Text Available In many natural audiovisual events (e.g., a clap of the two hands, the visual signal precedes the sound and thus allows observers to predict when, where, and which sound will occur. Previous studies have already reported that there are distinct neural correlates of temporal (when versus phonetic/semantic (which content on audiovisual integration. Here we examined the effect of visual prediction of auditory location (where in audiovisual biological motion stimuli by varying the spatial congruency between the auditory and visual part of the audiovisual stimulus. Visual stimuli were presented centrally, whereas auditory stimuli were presented either centrally or at 90° azimuth. Typical subadditive amplitude reductions (AV – V < A were found for the auditory N1 and P2 for spatially congruent and incongruent conditions. The new finding is that the N1 suppression was larger for spatially congruent stimuli. A very early audiovisual interaction was also found at 30-50 ms in the spatially congruent condition, while no effect of congruency was found on the suppression of the P2. This indicates that visual prediction of auditory location can be coded very early in auditory processing.

Radioactivity in papers: the concentration and source of naturally occurring radionuclides

International Nuclear Information System (INIS)

Kobashi, Asaya

2005-01-01

The radioactivities of naturally occurring radionuclides ( 226 Ra, 228 Ra, 228 Th and 40 K) in papers such as magazines, newspapers, and copying papers produced in Japan were determined by gamma-ray spectrometry to obtain information on radioactivity level of papers. The X-ray diffraction measurement of the samples was also carried out to elucidate the source of radionuclides contained in them. The average 226 Ra, 228 Ra, 228 Th, and 40 K contents of pocket-sized books were 6.4, 21.5, 23.7, and 18.8 Bq kg -1 , respectively, and those of other kinds of samples were near to or less than the values. The 228 Th content was generally somewhat higher than the 228 Ra content. Possibly 228 Ra was leached from the raw materials of the papers to water during their production in preference to 228 Th. The concentrations of the naturally occurring radionuclides were correlated to each other. The X-ray diffraction study showed that kaolinite, talc, and calcite were contained in the papers. The kaolinite content of the samples was correlated to the concentrations of the naturally occurring radionuclides, indicating that the naturally occurring radionuclides in the paper samples were mainly brought with kaolinite used as filler or coating pigment in the papers. The regression analysis of the data showed that the natural radioactivity content of filler kaolinite was higher than that of pigment kaolinite. (author)

Sourcing methane and carbon dioxide emissions from a small city: Influence of natural gas leakage and combustion.

Science.gov (United States)

Chamberlain, Samuel D; Ingraffea, Anthony R; Sparks, Jed P

2016-11-01

Natural gas leakage and combustion are major sources of methane (CH 4 ) and carbon dioxide (CO 2 ), respectively; however, our understanding of emissions from cities is limited. We mapped distribution pipeline leakage using a mobile CH 4 detection system, and continuously monitored atmospheric CO 2 and CH 4 concentrations and carbon isotopes (δ 13 C-CO 2 and δ 13 C-CH 4 ) for one-year above Ithaca, New York. Pipeline leakage rates were low (emission source in that wind sector. Our results demonstrate pipeline leakage rates are low in cities with a low extent of leak prone pipe, and natural gas power facilities may be an important source of urban and suburban emissions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nature of the Diffuse Source and Its Central Point-like Source in SNR 0509–67.5

Energy Technology Data Exchange (ETDEWEB)

Litke, Katrina C.; Chu, You-Hua; Holmes, Abigail; Santucci, Robert; Blindauer, Terrence; Gruendl, Robert A.; Ricker, Paul M. [Astronomy Department, University of Illinois, 1002 W. Green Street, Urbana, IL 61801 (United States); Li, Chuan-Jui [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan, R.O.C. (China); Pan, Kuo-Chuan [Departement Physik, Universität Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Weisz, Daniel R., E-mail: kclitke@email.arizona.edu [Department of Astronomy, University of California, 501 Cambell Hall #3411, Berkeley, CA 94720-3411 (United States)

2017-03-10

We examine a diffuse emission region near the center of SNR 0509−67.5 to determine its nature. Within this diffuse region we observe a point-like source that is bright in the near-IR, but is not visible in the B and V bands. We consider an emission line observed at 6766 Å and the possibilities that it is Ly α , H α , and [O ii] λ 3727. We examine the spectral energy distribution (SED) of the source, comprised of Hubble Space Telescope B , V , I , J , and H bands in addition to Spitzer /IRAC 3.6, 4.5, 5.8, and 8 μ m bands. The peak of the SED is consistent with a background galaxy at z ≈ 0.8 ± 0.2 and a possible Balmer jump places the galaxy at z ≈ 0.9 ± 0.3. These SED considerations support the emission line’s identification as [O ii] λ 3727. We conclude that the diffuse source in SNR 0509−67.5 is a background galaxy at z ≈ 0.82. Furthermore, we identify the point-like source superposed near the center of the galaxy as its central bulge. Finally, we find no evidence for a surviving companion star, indicating a double-degenerate origin for SNR 0509−67.5.

Nature of the Diffuse Source and Its Central Point-like Source in SNR 0509–67.5

International Nuclear Information System (INIS)

Litke, Katrina C.; Chu, You-Hua; Holmes, Abigail; Santucci, Robert; Blindauer, Terrence; Gruendl, Robert A.; Ricker, Paul M.; Li, Chuan-Jui; Pan, Kuo-Chuan; Weisz, Daniel R.

2017-01-01

We examine a diffuse emission region near the center of SNR 0509−67.5 to determine its nature. Within this diffuse region we observe a point-like source that is bright in the near-IR, but is not visible in the B and V bands. We consider an emission line observed at 6766 Å and the possibilities that it is Ly α , H α , and [O ii] λ 3727. We examine the spectral energy distribution (SED) of the source, comprised of Hubble Space Telescope B , V , I , J , and H bands in addition to Spitzer /IRAC 3.6, 4.5, 5.8, and 8 μ m bands. The peak of the SED is consistent with a background galaxy at z ≈ 0.8 ± 0.2 and a possible Balmer jump places the galaxy at z ≈ 0.9 ± 0.3. These SED considerations support the emission line’s identification as [O ii] λ 3727. We conclude that the diffuse source in SNR 0509−67.5 is a background galaxy at z ≈ 0.82. Furthermore, we identify the point-like source superposed near the center of the galaxy as its central bulge. Finally, we find no evidence for a surviving companion star, indicating a double-degenerate origin for SNR 0509−67.5.

Seasonal variation and potential sources of Cryptosporidium contamination in surface waters of Chao Phraya River and Bang Pu Nature Reserve pier, Thailand.

Science.gov (United States)

Koompapong, Khuanchai; Sukthana, Yaowalark

2012-07-01

Using molecular techniques, a longitudinal study was conducted with the aims at identifying the seasonal difference of Cryptosporidium contamination in surface water as well as analyzing the potential sources based on species information. One hundred forty-four water samples were collected, 72 samples from the Chao Phraya River, Thailand, collected in the summer, rainy and cool seasons and 72 samples from sea water at Bang Pu Nature Reserve pier, collected before, during and after the presence of migratory seagulls. Total prevalence of Cryptosporidium contamination in river and sea water locations was 11% and 6%, respectively. The highest prevalence was observed at the end of rainy season continuing into the cool season in river water (29%) and in sea water (12%). During the rainy season, prevalence of Cryptosporidium was 4% in river and sea water samples, but none in summer season. All positive samples from the river was C. parvum, while C. meleagridis (1), and C. serpentis (1) were obtained from sea water. To the best of our knowledge, this is the first genetic study in Thailand of Cryptosporidium spp contamination in river and sea water locations and the first report of C. serpentis, suggesting that humans, household pets, farm animals, wildlife and migratory birds may be the potential sources of the parasites. The findings are of use for implementing preventive measures to reduce the transmission of cryptosporidiosis to both humans and animals.

Natural radiation; A radiacao natural

Energy Technology Data Exchange (ETDEWEB)

Feliciano, Vanusa Maria Delage

2016-07-01

Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included.

Bootstrap inversion technique for atmospheric trace gas source detection and quantification using long open-path laser measurements

Directory of Open Access Journals (Sweden)

C. B. Alden

2018-03-01

Full Text Available Advances in natural gas extraction technology have led to increased activity in the production and transport sectors in the United States and, as a consequence, an increased need for reliable monitoring of methane leaks to the atmosphere. We present a statistical methodology in combination with an observing system for the detection and attribution of fugitive emissions of methane from distributed potential source location landscapes such as natural gas production sites. We measure long (> 500 m, integrated open-path concentrations of atmospheric methane using a dual frequency comb spectrometer and combine measurements with an atmospheric transport model to infer leak locations and strengths using a novel statistical method, the non-zero minimum bootstrap (NZMB. The new statistical method allows us to determine whether the empirical distribution of possible source strengths for a given location excludes zero. Using this information, we identify leaking source locations (i.e., natural gas wells through rejection of the null hypothesis that the source is not leaking. The method is tested with a series of synthetic data inversions with varying measurement density and varying levels of model–data mismatch. It is also tested with field observations of (1 a non-leaking source location and (2 a source location where a controlled emission of 3.1  ×  10−5 kg s−1 of methane gas is released over a period of several hours. This series of synthetic data tests and outdoor field observations using a controlled methane release demonstrates the viability of the approach for the detection and sizing of very small leaks of methane across large distances (4+ km2 in synthetic tests. The field tests demonstrate the ability to attribute small atmospheric enhancements of 17 ppb to the emitting source location against a background of combined atmospheric (e.g., background methane variability and measurement uncertainty of 5 ppb (1σ, when

The location and nature of accumulated phosphorus in seven sludges from activated sludge plants which exhibited enhanced phosphorus removal

International Nuclear Information System (INIS)

Buchan, L.

1981-01-01

Electron microscopy combined with the energy dispersive analysis of X-rays (EDX) has been used to examine the nature of the phosphorus accumulated in sludges from seven activated sludge plants exhibiting enhanced phosphorus removal. Large phosphorus accumulations were located in identical structures in the sludges examined. The phosphorus was located in large electron-dense bodies, within large bacterial cells which were characteristically grouped in clusters. The calcium:phosphorus ratio of these electron-dense bodies precluded them from being any form of calcium phosphate precipitate. Quantitative analysis indicated that the electron-dense bodies contained in excess of 30% phosphorus. The results obtained are supportive of a biological mechanism of enhanced phosphorus uptake in activated sludge

Atmospheric mercury emissions in Australia from anthropogenic, natural and recycled sources

Science.gov (United States)

Nelson, Peter F.; Morrison, Anthony L.; Malfroy, Hugh J.; Cope, Martin; Lee, Sunhee; Hibberd, Mark L.; Meyer, C. P. (Mick); McGregor, John

2012-12-01

The United Nations Environment Programme (UNEP) has begun a process of developing a legally binding instrument to manage emissions of mercury from anthropogenic sources. The UNEP Governing Council has concluded that there is sufficient evidence of significant global adverse impacts from mercury to warrant further international action; and that national, regional and global actions should be initiated as soon as possible to identify populations at risk and to reduce human generated releases. This paper describes the development of, and presents results from, a comprehensive, spatially and temporally resolved inventory of atmospheric mercury emissions from the Australian landmass. Results indicate that the best estimate of total anthropogenic emissions of mercury to the atmosphere in 2006 was 15 ± 5 tonnes. Three industrial sectors contribute substantially to Australian anthropogenic emissions: gold smelting (˜50%, essentially from a single site/operation), coal combustion in power plants (˜15%) and alumina production from bauxite (˜12%). A diverse range of other sectors contribute smaller proportions of the emitted mercury, but industrial emissions account for around 90% of total anthropogenic mercury emissions. The other sectors include other industrial sources (mining, smelting, and cement production) and the use of products containing mercury. It is difficult to determine historical trends in mercury emissions given the large uncertainties in the data. Estimates for natural and re-emitted emissions from soil, water, vegetation and fires are made using meteorological models, satellite observations of land cover and soil and vegetation type, fuel loading, fire scars and emission factors which account for the effects of temperature, insolation and other environmental variables. These natural and re-emitted sources comfortably exceed the anthropogenic emissions, and comprise 4-12 tonnes per year from vegetation, 70-210 tonnes per year from soils, and 21-63 tonnes

41 CFR 101-26.602-5 - Procurement of natural gas from the wellhead and other supply sources.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Procurement of natural... Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS SUPPLY AND PROCUREMENT 26-PROCUREMENT SOURCES AND PROGRAM 26.6-Procurement Sources Other Than GSA § 101...

Natural Radionuclides and Isotopic Signatures for Determining Carbonaceous Aerosol Sources, Aerosol Lifetimes, and Washout Processes

International Nuclear Information System (INIS)

Gaffney, Jeffrey

2012-01-01

This is the final technical report. The project description is as follows: to determine the role of aerosol radiative forcing on climate, the processes that control their atmospheric concentrations must be understood, and aerosol sources need to be determined for mitigation. Measurements of naturally occurring radionuclides and stable isotopic signatures allow the sources, removal and transport processes, as well as atmospheric lifetimes of fine carbonaceous aerosols, to be evaluated.

Natural Radionuclides and Isotopic Signatures for Determining Carbonaceous Aerosol Sources, Aerosol Lifetimes, and Washout Processes

Energy Technology Data Exchange (ETDEWEB)

Gaffney, Jeffrey [Univ. of Arkansas, Little Rock, AR (United States)

2012-12-12

This is the final technical report. The project description is as follows: to determine the role of aerosol radiative forcing on climate, the processes that control their atmospheric concentrations must be understood, and aerosol sources need to be determined for mitigation. Measurements of naturally occurring radionuclides and stable isotopic signatures allow the sources, removal and transport processes, as well as atmospheric lifetimes of fine carbonaceous aerosols, to be evaluated.

Household location choices: implications for biodiversity conservation.

Science.gov (United States)

Peterson, M Nils; Chen, Xiaodong; Liu, Jianguo

2008-08-01

Successful conservation efforts require understanding human behaviors that directly affect biodiversity. Choice of household location represents an observable behavior that has direct effects on biodiversity conservation, but no one has examined the sociocultural predictors of this choice relative to its environmental impacts. We conducted a case study of the Teton Valley of Idaho and Wyoming (U.S.A.) that (1) explored relationships between sociodemographic variables, environmental attitudes, and the environmental impact of household location choices, (2) assessed the potential for small household sizes in natural areas to multiply the environmental impacts of household location decisions, and (3) evaluated how length of residency predicted the environmental attitudes of people living in natural areas. We collected sociodemographic data, spatial coordinates, and land-cover information in a survey of 416 households drawn from a random sample of Teton Valley residents (95% compliance rate). Immigrants (respondents not born in the study area) with the lowest education levels and least environmentally oriented attitudes lived in previously established residential areas in disproportionately high numbers, and older and more educated immigrants with the most environmentally oriented attitudes lived in natural areas in disproportionately high numbers. Income was not a significant predictor of household location decisions. Those living in natural areas had more environmental impact per person because of the location and because small households (educated, and potentially growing more environmentally oriented, these patterns are troubling for biodiversity conservation. Our results demonstrate a need for environmentalists to make household location decisions that reflect their environmental attitudes and future research to address how interactions between education level, environmental attitudes, population aging, and household location choices influence biodiversity

Testing seismic amplitude source location for fast debris-flow detection at Illgraben, Switzerland

Science.gov (United States)

Walter, Fabian; Burtin, Arnaud; McArdell, Brian W.; Hovius, Niels; Weder, Bianca; Turowski, Jens M.

2017-06-01

Heavy precipitation can mobilize tens to hundreds of thousands of cubic meters of sediment in steep Alpine torrents in a short time. The resulting debris flows (mixtures of water, sediment and boulders) move downstream with velocities of several meters per second and have a high destruction potential. Warning protocols for affected communities rely on raising awareness about the debris-flow threat, precipitation monitoring and rapid detection methods. The latter, in particular, is a challenge because debris-flow-prone torrents have their catchments in steep and inaccessible terrain, where instrumentation is difficult to install and maintain. Here we test amplitude source location (ASL) as a processing scheme for seismic network data for early warning purposes. We use debris-flow and noise seismograms from the Illgraben catchment, Switzerland, a torrent system which produces several debris-flow events per year. Automatic in situ detection is currently based on geophones mounted on concrete check dams and radar stage sensors suspended above the channel. The ASL approach has the advantage that it uses seismometers, which can be installed at more accessible locations where a stable connection to mobile phone networks is available for data communication. Our ASL processing uses time-averaged ground vibration amplitudes to estimate the location of the debris-flow front. Applied to continuous data streams, inversion of the seismic amplitude decay throughout the network is robust and efficient, requires no manual identification of seismic phase arrivals and eliminates the need for a local seismic velocity model. We apply the ASL technique to a small debris-flow event on 19 July 2011, which was captured with a temporary seismic monitoring network. The processing rapidly detects the debris-flow event half an hour before arrival at the outlet of the torrent and several minutes before detection by the in situ alarm system. An analysis of continuous seismic records furthermore

Testing seismic amplitude source location for fast debris-flow detection at Illgraben, Switzerland

Directory of Open Access Journals (Sweden)

F. Walter

2017-06-01

Full Text Available Heavy precipitation can mobilize tens to hundreds of thousands of cubic meters of sediment in steep Alpine torrents in a short time. The resulting debris flows (mixtures of water, sediment and boulders move downstream with velocities of several meters per second and have a high destruction potential. Warning protocols for affected communities rely on raising awareness about the debris-flow threat, precipitation monitoring and rapid detection methods. The latter, in particular, is a challenge because debris-flow-prone torrents have their catchments in steep and inaccessible terrain, where instrumentation is difficult to install and maintain. Here we test amplitude source location (ASL as a processing scheme for seismic network data for early warning purposes. We use debris-flow and noise seismograms from the Illgraben catchment, Switzerland, a torrent system which produces several debris-flow events per year. Automatic in situ detection is currently based on geophones mounted on concrete check dams and radar stage sensors suspended above the channel. The ASL approach has the advantage that it uses seismometers, which can be installed at more accessible locations where a stable connection to mobile phone networks is available for data communication. Our ASL processing uses time-averaged ground vibration amplitudes to estimate the location of the debris-flow front. Applied to continuous data streams, inversion of the seismic amplitude decay throughout the network is robust and efficient, requires no manual identification of seismic phase arrivals and eliminates the need for a local seismic velocity model. We apply the ASL technique to a small debris-flow event on 19 July 2011, which was captured with a temporary seismic monitoring network. The processing rapidly detects the debris-flow event half an hour before arrival at the outlet of the torrent and several minutes before detection by the in situ alarm system. An analysis of continuous seismic

Integrating GIS with fuzzy multi-criteria decision making for suitable wind farm locations

Energy Technology Data Exchange (ETDEWEB)

Iyappan, L.; Pandian, P.K. [Tagore Engineering College. Dept. of Civil Engineering, Tamil Nadu (India)

2012-07-01

Wind Energy is spatial in nature and the degree of potential wind farm locations are fuzzy i.e., the boundaries among highly, moderate and least suitable is not clear cut. The study area of this research covers entire taluk of Tirumangalam, Madurai District (India). In this study, to help wind energy companies, policy-makers and investors in evaluating potential wind farm locations in the Tirumangalam Taluk (Tamil Nadu, India), an adaptation of a Geographical Information System (GIS) and Fuzzy Multi-criteria Decision Making(FMDM) approach is attended. The entire processes were completed by using open source GIS software (Quantum GIS and GRASS GIS) with help of freely available data. The software tool takes inputs such as wind power density, Slope, Transmission lines, environmental factors, and economic factors to provide an in-depth analysis for suitable location options. (Author)

Sources of mercury in the Arctic

International Nuclear Information System (INIS)

Pacyna, J.M.; Keeler, G.J.

1995-01-01

Global and regional emission inventories of mercury are reviewed with special emphasis on the source regions with potential impact on the Arctic environment. These sources are located mostly in Eurasia and North America and emit almost 1300 t of Hg to the air annually. Combustion of fossil-fuels to produce electricity and heat is the major source of Hg. Major portion of the element emissions from this source is in a gaseous phase. A small portion of Hg emissions in Eurasia and North America is deposited in the Arctic region, perhaps 60 to 80 t annually. Additional amounts of Hg in the Arctic air originate from natural sources, although it is very difficult to quantify them. A small decrease of anthropogenic Hg emissions is observed in Europe at present. These emissions are expected to increase again in the near future. 28 refs., 1 fig., 3 tabs

Natural circulation analysis for the advanced neutron source reactor refueling process 11

Energy Technology Data Exchange (ETDEWEB)

Tucker, R.F.; Dasardhi, S.; Elkassabgi, Y. [Texas A& M Univ., Kingsville, TX (United States); Yoder, G.L. [Oak Ridge National Lab., TN (United States)

1995-09-01

During the refueling process of the Advanced Neutron Source Reactor (ANSR), the spent fuel elements must be moved from the primary coolant loop (containing D{sub 2}O), through a heavy water pool, and finally into a light water spent fuel storage area. The present refueling scheme utilizes remote refueling equipment to move the spent fuel elements through a D{sub 2}O filled stack and tunnel into a temporary storage canal. A transfer lock is used to move the spent fuel elements from the D{sub 2}O-filled interim storage canal to a light water pool. Each spent fuel element must be cooled during this process, using either natural circulation or forced convection. This paper presents a summary of the numerical techniques used to analyze natural circulation cooling of the ANSR fuel elements as well as selected results of the calculations. Details of the analysis indicate that coolant velocities below 10 cm/s exist in the coolant channels under single phase natural circulation conditions. Also, boiling does not occur within the channels if power levels are below a few hundred kW when the core transitions to natural circulation conditions.

Pricing the (European) option to switch between two energy sources: An application to crude oil and natural gas

International Nuclear Information System (INIS)

Gatfaoui, Hayette

2015-01-01

We consider a firm, which can choose between crude oil and natural gas to run its business. The firm selects the energy source, which minimizes its energy or production costs at a given time horizon. Assuming the energy strategy to be established over a fixed time window, the energy choice decision will be made at a given future date T. In this light, the firm's energy cost can be considered as a long position in a risk-free bond by an amount of the terminal oil price, and a short position in a European put option to switch from oil to gas by an amount of the terminal oil price too. As a result, the option to switch from crude oil to natural gas allows for establishing a hedging strategy with respect to energy costs. Modeling stochastically the underlying asset of the European put, we propose a valuation formula of the option to switch and calibrate the pricing formula to empirical data on a daily basis. Hence, our innovative framework handles widely the hedge against the price increase of any given energy source versus the price of another competing energy source (i.e. minimizing energy costs). Moreover, we provide a price for the cost-reducing effect of the capability to switch from one energy source to another one (i.e. hedging energy price risk). - Highlights: • We consider a firm, which chooses either crude oil or natural gas as an energy source. • The capability to switch offers the firm a hedge against energy commodity price risk. • A European put option prices the ability to switch from crude oil to natural gas. • The capability to switch between two energy sources reduces the firm's energy costs. • The discount illustrates the efficiency of the energy management policy (e.g. timing).

Red pepper (Capsicum annuum) carotenoids as a source of natural food colors: analysis and stability-a review.

Science.gov (United States)

Arimboor, Ranjith; Natarajan, Ramesh Babu; Menon, K Ramakrishna; Chandrasekhar, Lekshmi P; Moorkoth, Vidya

2015-03-01

Carotenoids are increasingly drawing the attention of researchers as a major natural food color due to their inherent nutritional characteristics and the implicated possible role in prevention and protection against degenerative diseases. In this report, we review the role of red pepper as a source for natural carotenoids. The composition of the carotenoids in red pepper and the application of different methodologies for their analysis were discussed in this report. The stability of red pepper carotenoids during post-harvest processing and storage is also reviewed. This review highlights the potential of red pepper carotenoids as a source of natural food colors and also discusses the need for a standardized approach for the analysis and reporting of composition of carotenoids in plant products and designing model systems for stability studies.

Anthropogenic and natural sources of acidity and metals and their influence on the structure of stream food webs.

Science.gov (United States)

Hogsden, Kristy L; Harding, Jon S

2012-03-01

We compared food web structure in 20 streams with either anthropogenic or natural sources of acidity and metals or circumneutral water chemistry in New Zealand. Community and diet analysis indicated that mining streams receiving anthropogenic inputs of acidic and metal-rich drainage had much simpler food webs (fewer species, shorter food chains, less links) than those in naturally acidic, naturally high metal, and circumneutral streams. Food webs of naturally high metal streams were structurally similar to those in mining streams, lacking fish predators and having few species. Whereas, webs in naturally acidic streams differed very little from those in circumneutral streams due to strong similarities in community composition and diets of secondary and top consumers. The combined negative effects of acidity and metals on stream food webs are clear. However, elevated metal concentrations, regardless of source, appear to play a more important role than acidity in driving food web structure. Copyright © 2011 Elsevier Ltd. All rights reserved.

The fractal nature materials microstructure influence on electrochemical energy sources

Directory of Open Access Journals (Sweden)

Mitić V.V.

2015-01-01

Full Text Available With increasing of the world energy crisis, research for new, renewable and alternative energy sources are in growth. The focus is on research areas, sometimes of minor importance and applications, where the different synthesis methods and microstructure properties optimization, performed significant improvement of output materials’ and components’ electro-physical properties, which is important for higher energy efficiency and in the electricity production (batteries and battery systems, fuel cells and hydrogen energy contribution. Also, the storage tanks capacity improvement, for the energy produced on such way, which is one of the most important development issues in the energy sphere, represents a very promising research and application area. Having in mind, the results achieved in the electrochemical energy sources field, especially electrolyte development, these energy sources, materials fractal nature optimization analysis contribution, have been investigated. Based on materials fractal structure research field, particularly electronic materials, we have performed microstructure influence parameters research in electrochemistry area. We have investigated the Ho2O3 concentration influence (from 0.01wt% to 1wt% and sintering temperature (from 1320°C to 1380°C, as consolidation parameters, and thus, also open the electrochemical function fractalization door and in the basic thermodynamic parameters the fractal correction introduced. The fractal dimension dependence on additive concentration is also investigated. [Projekat Ministarstva nauke Republike Srbije, br. 172057: Directed synthesis, structure and properties of multifunctional materials

Influence of sound source location on the behavior and physiology of the precedence effect in cats.

Science.gov (United States)

Dent, Micheal L; Tollin, Daniel J; Yin, Tom C T

2009-08-01

Psychophysical experiments on the precedence effect (PE) in cats have shown that they localize pairs of auditory stimuli presented from different locations in space based on the spatial position of the stimuli and the interstimulus delay (ISD) between the stimuli in a manner similar to humans. Cats exhibit localization dominance for pairs of transient stimuli with |ISDs| from approximately 0.4 to 10 ms, summing localization for |ISDs| 10 ms, which is the approximate echo threshold. The neural correlates to the PE have been described in both anesthetized and unanesthetized animals at many levels from auditory nerve to cortex. Single-unit recordings from the inferior colliculus (IC) and auditory cortex of cats demonstrate that neurons respond to both lead and lag sounds at ISDs above behavioral echo thresholds, but the response to the lag is reduced at shorter ISDs, consistent with localization dominance. Here the influence of the relative locations of the leading and lagging sources on the PE was measured behaviorally in a psychophysical task and physiologically in the IC of awake behaving cats. At all configurations of lead-lag stimulus locations, the cats behaviorally exhibited summing localization, localization dominance, and breakdown of fusion. Recordings from the IC of awake behaving cats show neural responses paralleling behavioral measurements. Both behavioral and physiological results suggest systematically shorter echo thresholds when stimuli are further apart in space.

Case Study of The ARRA-Funded GSHP Demonstration at the Natural Sources Building, Montana Tech

Energy Technology Data Exchange (ETDEWEB)

Malhotra, Mini [ORNL; Liu, Xiaobing [ORNL

2015-04-01

Under the American Recovery and Reinvestment Act (ARRA), 26 ground source heat pump (GSHP) projects were competitively selected in 2009 to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. One of the selected demonstration projects was proposed by Montana Tech of the University of Montana for a 56,000 sq ft, newly constructed, on-campus research facility – the Natural Resources Building (NRB) located in Butte, Montana. This demonstrated GSHP system consists of a 50 ton water-to-water heat pump and a closed-loop ground heat exchanger with two redundant 7.5 hp constant-speed pumps to use water in the nearby flooded mines as a heat source or heat sink. It works in conjunction with the originally installed steam HX and an aircooled chiller to provide space heating and cooling. It is coupled with the existing hot water and chilled water piping in the building and operates in the heating or cooling mode based on the outdoor air temperature. The ground loop pumps operate in conjunction with the existing pumps in the building hot and chilled water loops for the operation of the heat pump unit. The goal of this demonstration project is to validate the technical and economic feasibility of the demonstrated commercial-scale GSHP system in the region, and illustrate the feasibility of using mine waters as the heat sink and source for GSHP systems. Should the demonstration prove satisfactory and feasible, it will encourage similar GSHP applications using mine water, thus help save energy and reduce carbon emissions. The actual performance of the system is analyzed with available measured data for January through July 2014. The annual energy performance is predicted and compared with a baseline scenario, with the heating and cooling provided by the originally designed systems. The comparison is made in terms of energy savings, operating cost savings, cost-effectiveness, and environmental benefits. Finally

Simulation of preindustrial atmospheric methane to constrain the global source strength of natural wetlands

NARCIS (Netherlands)

Houweling, S; Dentener, F; Lelieveld, J

2000-01-01

Previous attempts to quantify the global source strength of CH4 from natural wetlands have resulted in a range of 90-260 TE(CH4) yr(-1). This relatively uncertain estimate significantly limits our understanding of atmospheric methane. In this study we reduce this uncertainty by simulating

Magnetic Data Interpretation for the Source-Edge Locations in Parts of the Tectonically Active Transition Zone of the Narmada-Son Lineament in Central India

Science.gov (United States)

Ghosh, G. K.

2016-02-01

The study has been carried out in the transition zone of the Narmada-Son lineament (NSL) which is seismically active with various geological complexities, upwarp movement of the mantle material into the crust through fault, fractures lamination and upwelling. NSL is one of the most prominent lineaments in central India after the Himalaya in the Indian geology. The area of investigation extends from longitude 80.25°E to 81.50°E and latitude 23.50°N to 24.37°N in the central part of the Indian continent. Different types of subsurface geological formations viz. alluvial, Gondwana, Deccan traps, Vindhyan, Mahakoshal, Granite and Gneisses groups exist in this area with varying geological ages. In this study area tectonic movement and crustal variation have been taken place during the past time and which might be reason for the variation of magnetic field. Magnetic anomaly suggests that the area has been highly disturbed which causes the Narmada-Son lineament trending in the ENE-WSW direction. Magnetic anomaly variation has been taken place due to the lithological variations subject to the changes in the geological contacts like thrusts and faults in this area. Shallow and deeper sources have been distinguished using frequency domain analysis by applying different filters. To enhance the magnetic data, various types of derivatives to identify the source-edge locations of the causative source bodies. The present study carried out the interpretation using total horizontal derivative, tilt angle derivative, horizontal tilt angle derivative and Cos (θ) derivative map to get source-edge locations. The results derived from various derivatives of magnetic data have been compared with the basement depth solutions calculated from 3D Euler deconvolution. It is suggested that total horizontal derivative, tilt angle derivative and Cos (θ) derivative are the most useful tools for identifying the multiple source edge locations of the causative bodies in this tectonically active

Nitric oxide-to-nitrogen dioxide conversion rates at a natural gas compressor station

International Nuclear Information System (INIS)

Gibbons, T.H.; Gebhart, D.H.

1992-01-01

An ambient air quality measurements program collected NO x data for a year at a natural gas compressor station located in the southwestern United States. This monitoring program had the unique characteristic of measuring ambient NO x concentrations at a remote location that was virtually free of NO sources other than the compressor station. These measurements indicate that the only source of NO x emissions in the area comes from the combustion of natural gas by the compressor station turbines. Thus, increases in NO 2 calculation of NO-to-NO 2 conversion rates. These results indicate 22 percent of the compressor station NO x emissions were converted to NO 2 in the near field. Regulatory modeling methods often assume that all NO x emissions exist as NO 2 . In an environment where ozone concentrations are relatively low, however, NO 2 concentrations are commonly calculated using the ozone limiting method (OLM), wherein NO conversion to NO 2 is limited by the amount of ozone present. Results from the measurement program show that the OLM generally overpredicts NO 2 concentrations in the near field. A partial conversion method is more suitable for predicting NO 2 concentrations for low-level natural gas combustion sources

A Fieldable-Prototype Large-Area Gamma-ray Imager for Orphan Source Search

Energy Technology Data Exchange (ETDEWEB)

Ziock, Klaus-Peter [ORNL; Fabris, Lorenzo [ORNL; Carr, Dennis [Lawrence Livermore National Laboratory (LLNL); Collins, Jeff [Lawrence Livermore National Laboratory (LLNL); Cunningham, Mark F [Lawrence Livermore National Laboratory (LLNL); Habte Ghebretatios, Frezghi [ORNL; Karnowski, Thomas Paul [ORNL; Marchant, William [University of California, Berkeley

2008-01-01

We have constructed a unique instrument for use in the search for orphan sources. The system uses gamma-ray imaging to "see through" the natural background variations that effectively limit the search range of normal devices to ~10 m. The imager is mounted in a 4.9- m-long trailer and can be towed by a large personal vehicle. Source locations are determined both in range and along the direction of travel as the vehicle moves. A fully inertial platform coupled to a Global Positioning System receiver is used to map the gamma-ray images onto overhead geospatial imagery. The resulting images provide precise source locations, allowing rapid follow-up work. The instrument simultaneously searches both sides of the street to a distance of 50 m (100-m swath) for milliCurieclass sources with near-perfect performance.

[Plants as a source of natural harmful substances].

Science.gov (United States)

Czerwiecki, Ludwik

2005-01-01

In this review the several data concerning phytotoxins as natural harmful substances of plants and phycotoxins--toxicants of algae were described. For example plants are source of pyrrolizidine alkaloids, glycoalkaloids, glucosinolates as well as glycosides, saponine and psolarens. Possible adverse effects of phytoestrogens as endocrine disruptors versus beneficial influence these substances on human organism were mentioned. About lectins as possible factors of some diseases was reported, as well as some proteins as allergens of soy and peanuts was mentioned. Accumulated by shellfish and fish the most important phycotoxins such as saxitoxin, okadaic acid, brevetoxins and ciguatoxins were described. Phycotoxins produced several poisoning symptoms. Microcystins and nodularin--cyanobacterial phycotoxins of freshwater, was mentioned. In conclusion, the need of limitation of permissible levels of some plant toxicants, development of analytical methods as well as knowledge of influence of some technological processes on toxic plant substances was highlighted. The importance of balanced diet as a tool of defense against plant toxicants was concluded.

Western Pacific liquefied natural gas

Energy Technology Data Exchange (ETDEWEB)

Woronuk, R. [WestPac Terminals Inc., Calgary, AB (Canada)

2005-07-01

This presentation addressed issues facing WestPac Terminals' proposed construction of a liquefied natural gas (LNG) terminal and associated facilities on the Ridley Island on the coast of British Columbia. WestPac Terminals Inc. has expertise in natural gas supply and demand, transportation, LNG and economic optimization. Although a review of proposals for receiving terminals in North America has demonstrated the urgency and attractiveness of LNG imports, west coast terminals are not proceeding, largely due to lack of support by local communities. WestPac's proposal includes a deep enough port to accommodate the largest LNG tankers; a port en route to west coast terminal locations to serve as a transshipment hub; sufficient space for LNG storage tanks and natural gas liquids extraction; sea, rail, air and highway access. Other solutions include selecting locations where communities are pro-development where LNG terminals can provide direct financial benefits to the community, and using existing infrastructure to minimize socio-economic impacts. The advantages of developing LNG at the proposed site were discussed in terms of serving energy markets and provincial benefits. LNG source and cost issues were reviewed along with existing markets and required infrastructure for LNG market development. tabs., figs.

Natural background radiation in Saudi Arabia

International Nuclear Information System (INIS)

Al-Hussan, K.A.; Al-Suliman, K.M.; Wafa, N.F.

1993-01-01

Natural background radiation measurements have been made at numerous locations throughout the world. Little work in this field has been done in developing countries. In this study, the external exposure rates due to natural background radiation sources have been measured for different Saudi Arabian cities. Thermoluminescence dosimeters, CaF 2 Dy(TLD-200), has been used for field measurements. Exposure to TLD's response correlations were obtained for each TLD using a 137 Cs source. A correlation of TLD's response fading at a continuous radiation exposure environment was obtained and applied to correct field measurements. The measurements were taken every two months for a total of six intervals during the whole year. The average measurements of outdoor external exposure rates was found to vary between a minimum of 5.29 μR h -1 in Dammam city and a maximum of 11.59 μR h -1 in Al-Khamis city. (1 fig., 1 tab.)

Strength Restoration of Cracked Sandstone and Coal under a Uniaxial Compression Test and Correlated Damage Source Location Based on Acoustic Emissions

Science.gov (United States)

Feng, Xiaowei; Zhang, Nong; Zheng, Xigui; Pan, Dongjiang

2015-01-01

Underground rock masses have shown a general trend of natural balance over billions of years of ground movement. Nonetheless, man-made underground constructions disturb this balance and cause rock stability failure. Fractured rock masses are frequently encountered in underground constructions, and this study aims to restore the strength of rock masses that have experienced considerable fracturing under uniaxial compression. Coal and sandstone from a deep-buried coal mine were chosen as experimental subjects; they were crushed by uniaxial compression and then carefully restored by a chemical adhesive called MEYCO 364 with an innovative self-made device. Finally, the restored specimens were crushed once again by uniaxial compression. Axial stress, axial strain, circumferential strain, and volumetric strain data for the entire process were fully captured and are discussed here. An acoustic emission (AE) testing system was adopted to cooperate with the uniaxial compression system to provide better definitions for crack closure thresholds, crack initiation thresholds, crack damage thresholds, and three-dimensional damage source locations in intact and restored specimens. Several remarkable findings were obtained. The restoration effects of coal are considerably better than those of sandstone because the strength recovery coefficient of the former is 1.20, whereas that of the latter is 0.33, which indicates that MEYCO 364 is particularly valid for fractured rocks whose initial intact peak stress is less than that of MEYCO 364. Secondary cracked traces of restored sandstone almost follow the cracked traces of the initial intact sandstone, and the final failure is mainly caused by decoupling between the adhesive and the rock mass. However, cracked traces of restored coal only partially follow the traces of intact coal, with the final failure of the restored coal being caused by both bonding interface decoupling and self-breakage in coal. Three-dimensional damage source

Strength Restoration of Cracked Sandstone and Coal under a Uniaxial Compression Test and Correlated Damage Source Location Based on Acoustic Emissions.

Directory of Open Access Journals (Sweden)

Xiaowei Feng

Full Text Available Underground rock masses have shown a general trend of natural balance over billions of years of ground movement. Nonetheless, man-made underground constructions disturb this balance and cause rock stability failure. Fractured rock masses are frequently encountered in underground constructions, and this study aims to restore the strength of rock masses that have experienced considerable fracturing under uniaxial compression. Coal and sandstone from a deep-buried coal mine were chosen as experimental subjects; they were crushed by uniaxial compression and then carefully restored by a chemical adhesive called MEYCO 364 with an innovative self-made device. Finally, the restored specimens were crushed once again by uniaxial compression. Axial stress, axial strain, circumferential strain, and volumetric strain data for the entire process were fully captured and are discussed here. An acoustic emission (AE testing system was adopted to cooperate with the uniaxial compression system to provide better definitions for crack closure thresholds, crack initiation thresholds, crack damage thresholds, and three-dimensional damage source locations in intact and restored specimens. Several remarkable findings were obtained. The restoration effects of coal are considerably better than those of sandstone because the strength recovery coefficient of the former is 1.20, whereas that of the latter is 0.33, which indicates that MEYCO 364 is particularly valid for fractured rocks whose initial intact peak stress is less than that of MEYCO 364. Secondary cracked traces of restored sandstone almost follow the cracked traces of the initial intact sandstone, and the final failure is mainly caused by decoupling between the adhesive and the rock mass. However, cracked traces of restored coal only partially follow the traces of intact coal, with the final failure of the restored coal being caused by both bonding interface decoupling and self-breakage in coal. Three

Natural environmental water sources in endemic regions of northeastern Brazil are potential reservoirs of viable Mycobacterium leprae.

Science.gov (United States)

Arraes, Maria Luisa Bezerra de Macedo; Holanda, Maísa Viana de; Lima, Luana Nepomuceno Gondim Costa; Sabadia, José Antônio Beltrão; Duarte, Cynthia Romariz; Almeida, Rosa Livia Freitas; Kendall, Carl; Kerr, Ligia Regina Sansigolo; Frota, Cristiane Cunha

2017-12-01

The detection of live Mycobacterium leprae in soil and animals other than humans suggests that the environment plays a role in the transmission of leprosy. The objective of this study was to investigate the presence of viable M. leprae in natural water sources used by the local population in five municipalities in the state of Ceará, northeastern Brazil. Samples were collected from 30 different sources. Viable bacilli were identified by reverse transcriptase polymerase chain reaction (PCR) of the M. leprae gyrA gene and sequencing of the PCR products. Physicochemical properties of each water source were also assessed. M. leprae gyrA mRNA was found in 23 (76.7%) of the water sources. No association was found between depth of the water and sample positivity, nor was there any association between the type of water used by the population and sample positivity. An association between viable M. leprae and temperature and pH was found. Georeferencing showed a relation between the residences of leprosy cases and water source containing the bacterium. The finding of viable M. leprae in natural water sources associated with human contact suggests that the environment plays an important role in maintaining endemic leprosy in the study region.

Joint sensor location/power rating optimization for temporally-correlated source estimation

KAUST Repository

Bushnaq, Osama M.; Chaaban, Anas; Al-Naffouri, Tareq Y.

2017-01-01

via wireless AWGN channel. In addition to selecting the optimal sensing location, the sensor type to be placed in these locations is selected from a pool of T sensor types such that different sensor types have different power ratings and costs

Influence of the vibration source location on the modes of jet disintegration in the priller and on monodispersity of the finished product

OpenAIRE

Skydanenko, Maksym; Kononenko, Mykola; Kurdes, Yuliia

2017-01-01

Influence of the vibration source location on the modes of liquid jets disintegration and obtaining monodisperse droplets and granules of the finished product is theoretically grounded and experimentally confirmed. The experiment was conducted on an experimental stand of industrial granulation equipment.

Sources of Free and Open Source Spatial Data for Natural Disasters and Principles for Use in Developing Country Contexts

Science.gov (United States)

Taylor, Faith E.; Malamud, Bruce D.; Millington, James D. A.

2016-04-01

Access to reliable spatial and quantitative datasets (e.g., infrastructure maps, historical observations, environmental variables) at regional and site specific scales can be a limiting factor for understanding hazards and risks in developing country settings. Here we present a 'living database' of >75 freely available data sources relevant to hazard and risk in Africa (and more globally). Data sources include national scientific foundations, non-governmental bodies, crowd-sourced efforts, academic projects, special interest groups and others. The database is available at http://tinyurl.com/africa-datasets and is continually being updated, particularly in the context of broader natural hazards research we are doing in the context of Malawi and Kenya. For each data source, we review the spatiotemporal resolution and extent and make our own assessments of reliability and usability of datasets. Although such freely available datasets are sometimes presented as a panacea to improving our understanding of hazards and risk in developing countries, there are both pitfalls and opportunities unique to using this type of freely available data. These include factors such as resolution, homogeneity, uncertainty, access to metadata and training for usage. Based on our experience, use in the field and grey/peer-review literature, we present a suggested set of guidelines for using these free and open source data in developing country contexts.

Sound Spectrum Influences Auditory Distance Perception of Sound Sources Located in a Room Environment

Directory of Open Access Journals (Sweden)

Ignacio Spiousas

2017-06-01

Full Text Available Previous studies on the effect of spectral content on auditory distance perception (ADP focused on the physically measurable cues occurring either in the near field (low-pass filtering due to head diffraction or when the sound travels distances >15 m (high-frequency energy losses due to air absorption. Here, we study how the spectrum of a sound arriving from a source located in a reverberant room at intermediate distances (1–6 m influences the perception of the distance to the source. First, we conducted an ADP experiment using pure tones (the simplest possible spectrum of frequencies 0.5, 1, 2, and 4 kHz. Then, we performed a second ADP experiment with stimuli consisting of continuous broadband and bandpass-filtered (with center frequencies of 0.5, 1.5, and 4 kHz and bandwidths of 1/12, 1/3, and 1.5 octave pink-noise clips. Our results showed an effect of the stimulus frequency on the perceived distance both for pure tones and filtered noise bands: ADP was less accurate for stimuli containing energy only in the low-frequency range. Analysis of the frequency response of the room showed that the low accuracy observed for low-frequency stimuli can be explained by the presence of sparse modal resonances in the low-frequency region of the spectrum, which induced a non-monotonic relationship between binaural intensity and source distance. The results obtained in the second experiment suggest that ADP can also be affected by stimulus bandwidth but in a less straightforward way (i.e., depending on the center frequency, increasing stimulus bandwidth could have different effects. Finally, the analysis of the acoustical cues suggests that listeners judged source distance using mainly changes in the overall intensity of the auditory stimulus with distance rather than the direct-to-reverberant energy ratio, even for low-frequency noise bands (which typically induce high amount of reverberation. The results obtained in this study show that, depending on

Joint sensor location/power rating optimization for temporally-correlated source estimation

KAUST Repository

Bushnaq, Osama M.

2017-12-22

The optimal sensor selection for scalar state parameter estimation in wireless sensor networks is studied in the paper. A subset of N candidate sensing locations is selected to measure a state parameter and send the observation to a fusion center via wireless AWGN channel. In addition to selecting the optimal sensing location, the sensor type to be placed in these locations is selected from a pool of T sensor types such that different sensor types have different power ratings and costs. The sensor transmission power is limited based on the amount of energy harvested at the sensing location and the type of the sensor. The Kalman filter is used to efficiently obtain the MMSE estimator at the fusion center. Sensors are selected such that the MMSE estimator error is minimized subject to a prescribed system budget. This goal is achieved using convex relaxation and greedy algorithm approaches.

Using geochemistry to identify the source of groundwater to Montezuma Well, a natural spring in Central Arizona, USA: Part 2

Science.gov (United States)

Johnson, Raymond H.; DeWitt, Ed; Wirt, Laurie; Manning, Andrew H.; Hunt, Andrew G.

2012-01-01

Montezuma Well is a unique natural spring located in a sinkhole surrounded by travertine. Montezuma Well is managed by the National Park Service, and groundwater development in the area is a potential threat to the water source for Montezuma Well. This research was undertaken to better understand the sources of groundwater to Montezuma Well. Strontium isotopes (87Sr/86Sr) indicate that groundwater in the recharge area has flowed through surficial basalts with subsequent contact with the underlying Permian aged sandstones and the deeper, karstic, Mississippian Redwall Limestone. The distinctive geochemistry in Montezuma Well and nearby Soda Springs (higher concentrations of alkalinity, As, B, Cl, and Li) is coincident with added carbon dioxide and mantle-sourced He. The geochemistry and isotopic data from Montezuma Well and Soda Springs allow for the separation of groundwater samples into four categories: (1) upgradient, (2) deep groundwater with carbon dioxide, (3) shallow Verde Formation, and (4) mixing zone. δ18O and δD values, along with noble gas recharge elevation data, indicate that the higher elevation areas to the north and east of Montezuma Well are the groundwater recharge zones for Montezuma Well and most of the groundwater in this portion of the Verde Valley. Adjusted groundwater age dating using likely 14C and δ13C sources indicate an age for Montezuma Well and Soda Springs groundwaters at 5,400–13,300 years, while shallow groundwater in the Verde Formation appears to be older (18,900). Based on water chemistry and isotopic evidence, groundwater flow to Montezuma Well is consistent with a hydrogeologic framework that indicates groundwater flow by (1) recharge in higher elevation basalts to the north and east of Montezuma Well, (2) movement through the upgradient Permian and Mississippian units, especially the Redwall Limestone, and (3) contact with a basalt dike/fracture system that provides a mechanism for groundwater to flow to the surface

Mineral Carbonation Potential of CO2 from Natural and Industrial-based Alkalinity Sources

Science.gov (United States)

Wilcox, J.; Kirchofer, A.

2014-12-01

Mineral carbonation is a Carbon Capture and Storage (CSS) technology where gaseous CO2 is reacted with alkaline materials (such as silicate minerals and alkaline industrial wastes) and converted into stable and environmentally benign carbonate minerals (Metz et al., 2005). Here, we present a holistic, transparent life cycle assessment model of aqueous mineral carbonation built using a hybrid process model and economic input-output life cycle assessment approach. We compared the energy efficiency and the net CO2 storage potential of various mineral carbonation processes based on different feedstock material and process schemes on a consistent basis by determining the energy and material balance of each implementation (Kirchofer et al., 2011). In particular, we evaluated the net CO2 storage potential of aqueous mineral carbonation for serpentine, olivine, cement kiln dust, fly ash, and steel slag across a range of reaction conditions and process parameters. A preliminary systematic investigation of the tradeoffs inherent in mineral carbonation processes was conducted and guidelines for the optimization of the life-cycle energy efficiency are provided. The life-cycle assessment of aqueous mineral carbonation suggests that a variety of alkalinity sources and process configurations are capable of net CO2 reductions. The maximum carbonation efficiency, defined as mass percent of CO2 mitigated per CO2 input, was 83% for CKD at ambient temperature and pressure conditions. In order of decreasing efficiency, the maximum carbonation efficiencies for the other alkalinity sources investigated were: olivine, 66%; SS, 64%; FA, 36%; and serpentine, 13%. For natural alkalinity sources, availability is estimated based on U.S. production rates of a) lime (18 Mt/yr) or b) sand and gravel (760 Mt/yr) (USGS, 2011). The low estimate assumes the maximum sequestration efficiency of the alkalinity source obtained in the current work and the high estimate assumes a sequestration efficiency

Chlorine Isotopic Composition of Perchlorate in Human Urine as a Means of Distinguishing Among Natural and Synthetic Exposure Sources

Science.gov (United States)

Poghosyan, Armen; Morel-Espinosa, Maria; Valentín-Blasini, Liza; Blount, Benjamin C.; Ferreccio, Catterina; Steinmaus, Craig M.; Sturchio, Neil C.

2015-01-01

Perchlorate (ClO4−) is a ubiquitous environmental contaminant with high human exposure potential; it has both natural and man-made sources in the environment. Natural perchlorate forms in the atmosphere from where it deposits onto the surface of Earth, whereas synthetic perchlorate is manufactured as an oxidant for industrial, aerospace, and military applications. Perchlorate exposure can potentially cause adverse health effects in humans by interfering with the production of thyroid hormones through competitively blocking iodide uptake. To control and reduce perchlorate exposure, the contributions of different sources of perchlorate exposure need to be quantified. Thus, we demonstrate a novel approach for determining the contribution of different perchlorate exposure sources by quantifying stable and radioactive chlorine isotopes of perchlorate extracted from composite urine samples from two distinct populations: one in Atlanta, USA and one in Taltal, Chile (Atacama region). Urinary perchlorate from the Atlanta region resembles indigenous natural perchlorate from the southwestern USA [δ37Cl = +4.1 ± 1.0 ‰; 36Cl/Cl = 1811 (± 136) × 10−15], and urinary perchlorate from the Taltal, Chile region is similar to natural perchlorate in nitrate salt deposits from the Atacama Desert of northern Chile [δ37Cl = −11.0 ± 1.0 ‰; 36Cl/Cl = 254 (± 40) × 10−15]. Neither urinary perchlorate resembled the isotopic pattern found in synthetic perchlorate. These results indicate that natural perchlorate of regional provenance is the dominant exposure source for the two sample populations, and that chlorine isotope ratios provide a robust tool for elucidating perchlorate exposure pathways. PMID:25805252

Using web-sources for location based systems on mobile phones

OpenAIRE

Pannevis, M.; Marx, M.

2008-01-01

The paper describes the implementation of a context aware location and time based system on a normal mobile phone, with a minimum of requirements (Bluetooth, Internet access, Java ME, and a simple webbrowser). We can answer the following queries based on data crawled from the web and enriched with location coordinates: • Where are my friends? • What movies are playing, right here, right now? • I need to park my car. Where is the closest parking lot with free space? • What is a good place to h...

Natural convection in wavy enclosures with volumetric heat sources

International Nuclear Information System (INIS)

Oztop, H.F.; Varol, Y.; Abu-Nada, E.; Chamkha, A.

2011-01-01

In this paper, the effects of volumetric heat sources on natural convection heat transfer and flow structures in a wavy-walled enclosure are studied numerically. The governing differential equations are solved by an accurate finite-volume method. The vertical walls of enclosure are assumed to be heated differentially whereas the two wavy walls (top and bottom) are kept adiabatic. The effective governing parameters for this problem are the internal and external Rayleigh numbers and the amplitude of wavy walls. It is found that both the function of wavy wall and the ratio of internal Rayleigh number (Ra I ) to external Rayleigh number (Ra E ) affect the heat transfer and fluid flow significantly. The heat transfer is predicted to be a decreasing function of waviness of the top and bottom walls in case of (IRa/ERa)>1 and (IRa/ERa)<1. (authors)

Composition and source apportionment of dust fall around a natural lake.

Science.gov (United States)

Latif, Mohd Talib; Ngah, Sofia Aida; Dominick, Doreena; Razak, Intan Suraya; Guo, Xinxin; Srithawirat, Thunwadee; Mushrifah, Idris

2015-07-01

The aim of this study was to determine the source apportionment of dust fall around Lake Chini, Malaysia. Samples were collected monthly between December 2012 and March 2013 at seven sampling stations located around Lake Chini. The samples were filtered to separate the dissolved and undissolved solids. The ionic compositions (NO3-, SO4(2-), Cl- and NH4+) were determined using ion chromatography (IC) while major elements (K, Na, Ca and Mg) and trace metals (Zn, Fe, Al, Ni, Mn, Cr, Pb and Cd) were determined using inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the average concentration of total solids around Lake Chini was 93.49±16.16 mg/(m2·day). SO4(2-), Na and Zn dominated the dissolved portion of the dust fall. The enrichment factors (EF) revealed that the source of the trace metals and major elements in the rain water was anthropogenic, except for Fe. Hierarchical agglomerative cluster analysis (HACA) classified the seven monitoring stations and 16 variables into five groups and three groups respectively. A coupled receptor model, principal component analysis multiple linear regression (PCA-MLR), revealed that the sources of dust fall in Lake Chini were dominated by agricultural and biomass burning (42%), followed by the earth's crust (28%), sea spray (16%) and a mixture of soil dust and vehicle emissions (14%). Copyright © 2015. Published by Elsevier B.V.

Location of aerodynamic noise sources from a 200 kW vertical-axis wind turbine

Science.gov (United States)

Ottermo, Fredric; Möllerström, Erik; Nordborg, Anders; Hylander, Jonny; Bernhoff, Hans

2017-07-01

Noise levels emitted from a 200 kW H-rotor vertical-axis wind turbine have been measured using a microphone array at four different positions, each at a hub-height distance from the tower. The microphone array, comprising 48 microphones in a spiral pattern, allows for directional mapping of the noise sources in the range of 500 Hz to 4 kHz. The produced images indicate that most of the noise is generated in a narrow azimuth-angle range, compatible with the location where increased turbulence is known to be present in the flow, as a result of the previous passage of a blade and its support arms. It is also shown that a semi-empirical model for inflow-turbulence noise seems to produce noise levels of the correct order of magnitude, based on the amount of turbulence that could be expected from power extraction considerations.

Radon measurements over a natural-gas contaminated aquifer

International Nuclear Information System (INIS)

Palacios, D.; Fusella, E.; Avila, Y.; Salas, J.; Teixeira, D.; Fernández, G.; Salas, A.; Sajo-Bohus, L.; Greaves, E.; Barros, H.; Bolívar, M.; Regalado, J.

2013-01-01

Radon and thoron concentrations in soil pores in a gas production region of the Anzoategui State, Venezuela, were determined by active and passive methods. In this region, water wells are contaminated by natural gas and gas leaks exist in the nearby river. Based on soil gas Radon data surface hydrocarbon seeps were identified. Radon and thoron concentration maps show anomalously high values near the river gas leaks decreasing in the direction of water wells where natural gas is also detected. The area where the highest concentrations of 222 Rn were detected seems to indicate the surface projection of the aquifer contaminated with natural gas. The Radon/Thoron ratio revealed a micro-localized anomaly, indicating the area where the gas comes from deep layers of the subsoil. The radon map determined by the passive method showed a marked positive anomaly around abandoned gas wells. The high anomalous Radon concentration localized near the trails of ascending gas bubbles at the river indicates the zone trough where natural gases are ascending with greater ease, associated with a deep geological fault, being this the main source of methane penetration into the aquifer. It is suggested that the source of the natural gas may be due to leaks at deep sites along the structure of some of the abandoned wells located at the North-East of the studied area. - Highlights: ► High Radon/Thoron ratios were localized near the natural-gas emanations in a river. ► Natural gases are ascending trough a deep geological fault. ► Apparently, the radon anomaly shows the site where natural gas enters the aquifer. ► Natural gas source may be related to leaks in the structure of abandoned gas wells

Accumulations and sources of uranium, of its daughters and of metallic trace elements in wetlands located around old uranium mining sites

International Nuclear Information System (INIS)

Cuvier, Alicia

2015-01-01

Uranium mining and uranium ore processing increase the environmental activity of U and Th decay products and trace elements, in particular in case of releases to the adjacent rivers. Contaminants accumulate then preferentially in sedimentation areas (such as ponds or lakes) or in wetlands (peat lands, marshes or riverbanks) located downstream to the mine. Wetlands - generally located at the head of watershed - are particularly sensitive to environmental changes and anthropogenic pressure. This poses a risk of release of contaminants from these accumulation areas. The objective of the present study is to propose an easily reproducible methodology - in particular for the orphan mining sites - to identify and characterize accumulation areas. This study also aims to improve our understanding of the mechanisms of accumulation and release, in these areas. This study was performed around the former mining site of Bertholene (France). Standing and mobile in situ gamma spectrometry is used to accurately locate the accumulation areas. Soils, sediments, vegetation, water and peat are also sampled upstream and downstream of the mine, in order to (a) characterize the activities and the disequilibria of the U-Th decay chains and the associated trace elements according to the scale of observation, (b) understand the mechanisms of accumulation and release and (c) identify the potential sources using geochemical proxies and isotopic analyses. The results obtained show that radionuclides are mainly accumulated in a flooding area located downstream the mine. Strong U-238 activities (≥ 20000 Bq.kg"-"1) and strong Ra-226/U-238 and Th-230/Ra-226 activity ratios are recorded, involving preferential inputs of U-238 and Th-230 during flooding events. Trace element contamination is low, except for Mn, Ba and S. Such contaminations are potentially explained by the geochemical composition of the uranium ore and by the past and current processes of ore and water mine. Sequential extractions

Estimation of impact from natural sources of radiation sources in two non nuclear plant workers and nearby residents

International Nuclear Information System (INIS)

Sousa, Wanderson de Oliveira

2005-09-01

Naturally occurring radioactive materials, often referred to as NORM, are and always have been a part of our world. Our planet 'Earth' and its atmosphere contain many different types of naturally occurring radioactive species , mainly minerals containing radionuclides of uranium and thorium decay series. Human activities for e x p l o i t a t i o n of mineral resources as mining, necessarily, do not enhance the concentration of NORM in products , by-products or residues, but can be a concern, simply due to the increased potential for human exposure. The goal of this work is to assess the impact of the presence of two non-nuclear plants (coal mining and monazite extraction plant) to workers and general population living in the vicinities of plants, by calculating their internal exposure to natural radionuclides . Excreta samples (urine and feces) were collected from workers and inhabitants of the two small towns where workers reside. The activities of 238 U, 234 U ( o n l y in feces), 226 Ra , 210 Pb and 210 Po (only in urine),- present in the samples were determined. The results of daily excretion in urine and feces of the groups, indicate that workers from coal mining, are exposed to natural radionuclides by inhalation and ingestion. The intake of some radionuclides ( 238 U and 210 Po ) are influenced by the professional activity . The results also indicate a chronic intake of 226 Ra by workers of the coal mining and their neighbors. Workers from the monazite extraction plant and inhabitants of the vicinity of the plant are exposed, mainly by ingestion. The intake through diet is the major source of incorporation of natural radionuclides. (author)

The gyrotron - a natural source of high-power orbital angular momentum millimeter-wave beams

Science.gov (United States)

Thumm, M.; Sawant, A.; Choe, M. S.; Choi, E. M.

2017-08-01

Orbital angular momentum (OAM) of electromagnetic-wave beams provides further diversity to multiplexing in wireless communication. The present report shows that higher-order mode gyrotrons are natural sources of high-power OAM millimeter (mm) wave beams. The well-defined OAM of their rotating cavity modes operating at near cutoff frequency has been derived by photonic and electromagnetic wave approaches.

Time-Reversal Study of the Hemet (CA) Tremor Source

Science.gov (United States)

Larmat, C. S.; Johnson, P. A.; Guyer, R. A.

2010-12-01

Since its first observation by Nadeau & Dolenc (2005) and Gomberg et al. (2008), tremor along the San Andreas fault system is thought to be a probe into the frictional state of the deep part of the fault (e.g. Shelly et al., 2007). Tremor is associated with slow, otherwise deep, aseismic slip events that may be triggered by faint signals such as passing waves from remote earthquakes or solid Earth tides.Well resolved tremor source location is key to constrain frictional models of the fault. However, tremor source location is challenging because of the high-frequency and highly-scattered nature of tremor signal characterized by the lack of isolated phase arrivals. Time Reversal (TR) methods are emerging as a useful tool for location. The unique requirement is a good velocity model for the different time-reversed phases to arrive coherently onto the source point. We present results of location for a tremor source near the town of Hemet, CA, which was triggered by the 2002 M 7.9 Denali Fault earthquake (Gomberg et al., 2008) and by the 2009 M 6.9 Gulf of California earthquake. We performed TR in a volume model of 88 (N-S) x 70 (W-E) x 60 km (Z) using the full-wave 3D wave-propagation package SPECFEM3D (Komatitsch et al., 2002). The results for the 2009 episode indicate a deep source (at about 22km) which is about 4km SW the fault surface scarp. We perform STA/SLA and correlation analysis in order to have independent confirmation of the Hemet tremor source. We gratefully acknowledge the support of the U. S. Department of Energy through the LANL/LDRD Program for this work.

Acoustic wavefield evolution as a function of source location perturbation

KAUST Repository

Alkhalifah, Tariq Ali

2010-01-01

differential equations have the same structure as the wave equation with a source function that depends on the background (original source) wavefield. The similarity in form implies that we can use familiar numerical methods to solve the perturbation equations

Mercury Removal from Natural Gas in Egypt

International Nuclear Information System (INIS)

Korkor, H.; AI-Alf, A.; EI-Behairy, S.

2004-01-01

Worldwide natural gas is forecasted to be the fastest growing primary energy source. In Egypt, natural gas is recently playing a key role as one of the major energy sources. This is supported by adequate gas reserves, booming gas industry, and unique geographical location. Egypt's current proven gas reserves accounted for about 62 TCF, in addition to about 100 TCF as probable gas reserves. As a result, it was decided to enter the gas exporting market, where gas is transported through pipelines as in the Arab Gas pipelines project and as a liquid through the liquefied natural gas (LNG) projects in Damietta, and ld ku. With the start up of these currently implemented LNG projects that are dealing with the very low temperatures (down to -162 degree c), the gas has to be subjected to a regular analysis in order to check the compliance with the required specifications. Mercury is a trace component of all fossil fuels including natural gas, condensates, crude oil, coal, tar sands, and other bitumens. The use of fossil hydrocarbons as fuels provides the main opportunity for emissions of mercury they contain to the atmospheric environment: while other traces exist in production, transportation and processing systems

Mercury Removal from Natural Gas in Egypt

Energy Technology Data Exchange (ETDEWEB)

Korkor, H; AI-Alf, A; EI-Behairy, S [EGAS, Cairo (Egypt)

2004-07-01

Worldwide natural gas is forecasted to be the fastest growing primary energy source. In Egypt, natural gas is recently playing a key role as one of the major energy sources. This is supported by adequate gas reserves, booming gas industry, and unique geographical location. Egypt's current proven gas reserves accounted for about 62 TCF, in addition to about 100 TCF as probable gas reserves. As a result, it was decided to enter the gas exporting market, where gas is transported through pipelines as in the Arab Gas pipelines project and as a liquid through the liquefied natural gas (LNG) projects in Damietta, and ld ku. With the start up of these currently implemented LNG projects that are dealing with the very low temperatures (down to -162 degree c), the gas has to be subjected to a regular analysis in order to check the compliance with the required specifications. Mercury is a trace component of all fossil fuels including natural gas, condensates, crude oil, coal, tar sands, and other bitumens. The use of fossil hydrocarbons as fuels provides the main opportunity for emissions of mercury they contain to the atmospheric environment: while other traces exist in production, transportation and processing systems.

The Upper Danube Nature Park

International Nuclear Information System (INIS)

Dosedla, H.C.

1997-01-01

When in 1980 the Upper Danube Nature Park was founded as one of 65 nature sanctuaries in Germany there was great diversity of opinions concerning its intended character. The protected region consisting of a geologically outstanding landscape within central Europe is covering the first 80 km the upper Danube where the young river shortly after it's source in the Black Forest is breaking through the narrow canyons of the Jurassic rock plateau of the so-called Suebian Alps and also locates the subterranean passage where the stream is submerging from the surface for nearly ten miles. Since the purpose of nature preservation according to German las is closely combined with the rather contradicting aim of offering an attractive recreation area thus facing the immense impacts of modern mass tourism there are numerous problems which in the course of years have resulted in an intricate patterns of subtle management methods coping with the growing awareness of the ecological balance. (author)

Changes in Isotopic Composition of Bottled Natural Waters Due to Different Storage Conditions

Energy Technology Data Exchange (ETDEWEB)

Ferjan, T. [Geological Survey of Slovenia, Department of Hydrogeology, Ljubljana (Slovenia); Brencic, M. [Faculty of Natural Sciences and Engineering, Department of Geology, and Geological Survey of Slovenia, Department of Hydrogeology, Ljubljana (Slovenia); Vreca, P. [Jozef Stefan Institute, Department of Environmental Sciences, Ljubljana (Slovenia)

2013-07-15

To establish the influence of environmental conditions on processes affecting the stable isotopic composition of bottled water during storage, various brands of bottled water were exposed for 2 years in different conditions. Selected low mineralized natural mineral water of one particular brand stored in polyethylene terephthalate (PET) bottles was placed at three different locations with different physical conditions (temperature, relative humidity, air pressure, exposure to sunlight). For comparison, bottles of three other low mineralized natural mineral water brands, each from a different aquifer source, were placed in parallel at one of the locations. Each location was characterized by temperature, relative humidity and air pressure measurements. pH, conductivity and stable isotopic composition of oxygen, hydrogen and carbon in dissolved inorganic carbon ({delta}{sup 18}O, {delta}{sup 2}H, {delta}{sup 13}C{sub DIC}) were measured in regular intervals for nearly two years. Preliminary results from each location show noticeable changes in isotopic composition as well as the physical parameters of water with time of storage.

Characterizing the nature of visual conscious access: the distinction between features and locations.

Science.gov (United States)

Huang, Liqiang

2010-08-24

The difference between the roles of features and locations has been a central topic in the theoretical debates on visual attention. A recent theory proposed that momentary visual awareness is limited to one Boolean map, that is the linkage of one feature per dimension with a set of locations (L. Huang & H. Pashler, 2007). This theory predicts that: (a) access to the features of a set of objects is inefficient whereas access to their locations is efficient; (b) shuffling the locations of objects disrupts access to their features whereas shuffling the features of objects has little impact on access to their locations. Both of these predictions were confirmed in Experiments 1 and 2. Experiments 3 and 4 showed that this feature/location distinction remains when the task involves the detection of changes to old objects rather than the coding of new objects. Experiments 5 and 6 showed that, in a pre-specified set, one missing location can be readily detected, but detecting one missing color is difficult. Taken together, multiple locations seem to be accessed and represented together as a holistic pattern, but features have to be handled as separate labels, one at a time, and do not constitute a pattern in featural space.

Source signature of volatile organic compounds from oil and natural gas operations in northeastern Colorado.

Science.gov (United States)

Gilman, J B; Lerner, B M; Kuster, W C; de Gouw, J A

2013-02-05

An extensive set of volatile organic compounds (VOCs) was measured at the Boulder Atmospheric Observatory (BAO) in winter 2011 in order to investigate the composition and influence of VOC emissions from oil and natural gas (O&NG) operations in northeastern Colorado. BAO is 30 km north of Denver and is in the southwestern section of Wattenberg Field, one of Colorado's most productive O&NG fields. We compare VOC concentrations at BAO to those of other U.S. cities and summertime measurements at two additional sites in northeastern Colorado, as well as the composition of raw natural gas from Wattenberg Field. These comparisons show that (i) the VOC source signature associated with O&NG operations can be clearly differentiated from urban sources dominated by vehicular exhaust, and (ii) VOCs emitted from O&NG operations are evident at all three measurement sites in northeastern Colorado. At BAO, the reactivity of VOCs with the hydroxyl radical (OH) was dominated by C(2)-C(6) alkanes due to their remarkably large abundances (e.g., mean propane = 27.2 ppbv). Through statistical regression analysis, we estimate that on average 55 ± 18% of the VOC-OH reactivity was attributable to emissions from O&NG operations indicating that these emissions are a significant source of ozone precursors.

Evaluating measurements of carbon dioxide emissions using a precision source--A natural gas burner.

Science.gov (United States)

Bryant, Rodney; Bundy, Matthew; Zong, Ruowen

2015-07-01

A natural gas burner has been used as a precise and accurate source for generating large quantities of carbon dioxide (CO2) to evaluate emissions measurements at near-industrial scale. Two methods for determining carbon dioxide emissions from stationary sources are considered here: predicting emissions based on fuel consumption measurements-predicted emissions measurements, and direct measurement of emissions quantities in the flue gas-direct emissions measurements. Uncertainty for the predicted emissions measurement was estimated at less than 1%. Uncertainty estimates for the direct emissions measurement of carbon dioxide were on the order of ±4%. The relative difference between the direct emissions measurements and the predicted emissions measurements was within the range of the measurement uncertainty, therefore demonstrating good agreement. The study demonstrates how independent methods are used to validate source emissions measurements, while also demonstrating how a fire research facility can be used as a precision test-bed to evaluate and improve carbon dioxide emissions measurements from stationary sources. Fossil-fuel-consuming stationary sources such as electric power plants and industrial facilities account for more than half of the CO2 emissions in the United States. Therefore, accurate emissions measurements from these sources are critical for evaluating efforts to reduce greenhouse gas emissions. This study demonstrates how a surrogate for a stationary source, a fire research facility, can be used to evaluate the accuracy of measurements of CO2 emissions.

Natural gas seeps in the French Alps: Sources and pathways

Science.gov (United States)

Kloppmann, Wolfram; Blessing, Michaela; Proust, Eric; Gal, Frédéric; Bentivegna, Gaetan; Henry, Benoit; Defossez, Pierrick; Catherine, Lerouge; Humez, Pauline; Mayer, Bernhard; Millot, Romain; Gaucher, Eric

2016-04-01

Natural gas emanations are part of the geochemical baseline to take into account when assessing global greenhouse gas emissions and potential impacts of conventional and unconventional gas exploration and exploitation on groundwater. Examples of such natural gas macro-seeps are known in several parts of the world (Etiope et al., 2009). Only a limited number of them have been characterized for their gas and isotopic compositions. Such analyses can provide essential information for baseline studies, providing insight in the sources (biogenic vs. thermogenic or modified thermogenic) and pathways of such seeps and may allow for distinction of natural seeps from stray gas leakage associated with human activities. Here, we report gas concentrations and multi-isotope data (δ13C and δ2H of methane and ethane, δ13C and δ18O of CO2, 3He/4He ratio) of two gas seeps in the French subalpine chains, both in a similar geological and structural position within Middle Jurassic claystones along the eastern border of the large synclinal structures of the Vercors and the Chartreuse massifs (Moss, 1992). The "ardent fountain" (fontaine ardente) of Le Gua, 30 km south of Grenoble has most likely the longest continuous written record of existence of any individual natural gas seep, mentioned explicitly as early as the first quarter of the 5th century (Augustin of Hippo (St. Augustin), approx. 426) This natural seep was described in the past as a "wet seep" associated with a spring, whereas the second investigated seep, Rochasson near Meylan north of Grenoble, is a dry seep. Both seeps contain methane and ethane with thermogenic C and H isotope signatures, comparable with a seep in the Northern Swiss Alps at Giswil (Etiope et al., 2010) but with a higher dryness (C1/(C2+C3)>1000) for the Le Gua seep, possibly due to molecular fractionation upon advective fluid+gas migration (Etiope et al., 2009). Maturity (R0) of the reservoir rocks deduced from δ13C(CH4), δ13C(C2H6) is similar to

Regulatory control of natural ionizing sources in Lithuania: Experience based on indoor radon monitoring

International Nuclear Information System (INIS)

Mastauskas, A.; Morkunas, G.

1997-01-01

The situation in legislation of protection against risks from natural sources of ionizing radiation in Lithuania is described. The requirements of new standards came into conflict with the real situation which has not been evaluated before implementation of these standards. On the basis of recommendations of ICRP Publication 60 and results of indoor radon survey new action levels are being established. (author)

Discussion on the source survey method in a natural evaporation pond

International Nuclear Information System (INIS)

Dai Xiaoshu; Fan Chengrong; Fu Yunshan

2014-01-01

A natural evaporation pond intended to be decommissioned. The survey of the pond focused on investigating radioactive contamination distribution and estimating the total amount of deposits in the pond, in order to provide support for subsequent decommissioning activities. Based on the source survey in the pond, this paper introduced how to implement radiation measurements and sampling (such as water and sediment) in the water. The movable work platform was built on the pond to facilitate sampling and measurement. In addition, a sludge sampler had been designed so as to accurately determine the amount of sampling and its depth. This paper also described the distribution of sampling points. (authors)

The role of remediation, natural alkalinity sources and physical stream parameters in stream recovery.

Science.gov (United States)

Kruse, Natalie A; DeRose, Lisa; Korenowsky, Rebekah; Bowman, Jennifer R; Lopez, Dina; Johnson, Kelly; Rankin, Edward

2013-10-15

Acid mine drainage (AMD) negatively impacts not only stream chemistry, but also aquatic biology. The ultimate goal of AMD treatment is restoration of the biological community, but that goal is rarely explicit in treatment system design. Hewett Fork in Raccoon Creek Watershed, Ohio, has been impacted by historic coal mining and has been treated with a calcium oxide doser in the headwaters of the watershed since 2004. All of the acidic inputs are isolated to a 1.5 km stretch of stream in the headwaters of the Hewett Fork watershed. The macroinvertebrate and fish communities have begun to recover and it is possible to distinguish three zones downstream of the doser: an impaired zone, a transition zone and a recovered zone. Alkalinity from both the doser and natural sources and physical stream parameters play a role in stream restoration. In Hewett Fork, natural alkaline additions downstream are higher than those from the doser. Both, alkaline additions and stream velocity drive sediment and metal deposition. Metal deposition occurs in several patterns; aluminum tends to deposit in regions of low stream velocity, while iron tends to deposit once sufficient alkalinity is added to the system downstream of mining inputs. The majority of metal deposition occurs upstream of the recovered zone. Both the physical stream parameters and natural alkalinity sources influence biological recovery in treated AMD streams and should be considered in remediation plans. Copyright © 2013 Elsevier Ltd. All rights reserved.

Intoxication with natural sources

International Nuclear Information System (INIS)

Toropilova, D.; Toropila, M.; Tomko, M.; Takac, L.; Fric, M.

2015-01-01

The authors of this article deal with intoxication of the organism with natural resources. As objects of our interest we chose some interchangeable types of fungi which cause severe intoxication of gastrointestinal tract: Scleroderma citrinum, Boletus luridus var. rubriceps (Maire) Dermek, Boletus satanas, Agaricus xanthodermus and poisonous plants affect mainly digestive tract such as Sambucus nigra L. (elderberry). Sambucus ebulus L. (European dwarf elder), Viburnum lantana L. (wayfaring tree), Viburnum opulus (guelder-rose), Rhamnus cathartica (purging buckthorn).

Improving the quality of tiger shrimp Penaeus monodon through dietary incorporation of algae as a source of natural pigment

Directory of Open Access Journals (Sweden)

Kunal Mondal

2015-01-01

Full Text Available Tiger shrimp is one of the major candidate species for export oriented aquaculture which dominates the seafood market in regions of European Union, Japan and USA. Carotenoid content in seafood has now become one of the important criteria in determining the quality of edible product. Recent trends in supplementing fish diets with natural pigment source are an alternative to the utilization of expensive synthetic pigments. In this context, green algae Enteromorpha intestinalis was selected as a source of natural pigment for inclusion in the diet of tiger shrimp Penaeus monodon. Astaxanthin being an important category of carotenoid pigment was monitored in shrimp muscle tissue during the feeding trial. Significant variation (p<0.05 was observed between the experimental groups as confirmed through ANOVA thus exhibiting higher astaxanthin content of shrimps (18.70 Å} 4.48 ppm fed with E. intestinalis incorporated diet as compared to control (15.80 Å} 2.33 ppm. The present programme therefore emphasizes on the quality improvement of aquaculture product by dietary inclusion of algae as a natural pigment source.

Use of a vibrating plate to enhance natural convection cooling of a discrete heat source in a vertical channel

Energy Technology Data Exchange (ETDEWEB)

Florio, L.A.; Harnoy, A. [Department of Mechanical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102 (United States)

2007-09-15

A numerical investigation was conducted into an alternative method of natural convection enhancement by the transverse oscillations of a thin short plate, strategically positioned in close proximity to a rectangular heat source. The heat source is attached to a mounting board in a vertical channel. Two-dimensional laminar flow finite element studies were carried out with the oscillation parameters, the oscillating plate-heat source mean clearance spacing, and the oscillating plate position varied. Significant cooling was found for displacement amplitudes of at least one-third of the mean clearance together with frequencies (Re/{radical}(Gr)) of over 2{pi} with the displacement being more critical to the cooling level. For the parameters investigated, up to a 52% increase in the local heat transfer coefficient relative to standard natural convection was obtained. The results indicate that this method can serve as a feasible, simpler, more energy and space efficient alternative to common methods of cooling for low power dissipating devices operating at conditions just beyond the reach of pure natural convection. (author)

Predicting the locations of naturally fishless lakes

Science.gov (United States)

Schilling, Emily Gaenzle; Loftin, C.S.; Degoosh, K.E.; Huryn, Alexander D.; Webster, K.E.

2008-01-01

1. Fish have been introduced into many previously fishless lakes throughout North America over the past 100+ years. It is difficult to determine the historical distribution of fishless lakes, however, because these introductions have not always been well-documented. 2. Due to its glacial history and low human population density, the state of Maine (U.S.A.) may host the greatest number of naturally fishless lakes in the northeastern United States. However, less than one-quarter of Maine's 6000+ lakes have been surveyed for fish presence, and no accurate assessments of either the historical or current abundance and distribution of fishless lakes exist. 3. We developed methods to assess the abundance and distribution of Maine's naturally fishless lakes (0.6-10.1 ha). We hypothesized that the historical distribution of fishless lakes across a landscape is controlled by geomorphic and geographic conditions. 4. We used ArcGIS to identify landscape-scale geomorphic and geographic factors (e.g. connectivity, surrounding slope) correlated with fish absence in two geomorphic regions of Maine - the western and interior mountains and the eastern lowlands and foothills. By using readily available geographic information systems data our method was not limited to field-visited sites. We estimated the likelihood that a particular lake is fishless with a stepwise logistic regression model developed for each region. 5. The absence of fish from western lakes is related to altitude (+), minimum percent slope in the 500 m buffer (+), maximum percent slope in the 500 m buffer (+) and percent cover of herbaceous-emergent wetland in 1000 m buffer (-). The absence of fish from eastern lakes is related to the lack of a stream within 50 m of the lake. 6. The models predict that a total of 4% (131) of study lakes in the two regions were historically fishless, with the eastern region hosting a greater proportion than the western region. 7. We verified the model predictions with two

Global Scale Attribution of Anthropogenic and Natural Dust Sources and their Emission Rates Based on MODIS Deep Blue Aerosol Products

Science.gov (United States)

Ginoux, Paul; Prospero, Joseph M.; Gill, Thomas E.; Hsu, N. Christina; Zhao, Ming

2012-01-01

Our understanding of the global dust cycle is limited by a dearth of information about dust sources, especially small-scale features which could account for a large fraction of global emissions. Here we present a global-scale high-resolution (0.1 deg) mapping of sources based on Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue estimates of dust optical depth in conjunction with other data sets including land use. We ascribe dust sources to natural and anthropogenic (primarily agricultural) origins, calculate their respective contributions to emissions, and extensively compare these products against literature. Natural dust sources globally account for 75% of emissions; anthropogenic sources account for 25%. North Africa accounts for 55% of global dust emissions with only 8% being anthropogenic, mostly from the Sahel. Elsewhere, anthropogenic dust emissions can be much higher (75% in Australia). Hydrologic dust sources (e.g., ephemeral water bodies) account for 31% worldwide; 15% of them are natural while 85% are anthropogenic. Globally, 20% of emissions are from vegetated surfaces, primarily desert shrublands and agricultural lands. Since anthropogenic dust sources are associated with land use and ephemeral water bodies, both in turn linked to the hydrological cycle, their emissions are affected by climate variability. Such changes in dust emissions can impact climate, air quality, and human health. Improved dust emission estimates will require a better mapping of threshold wind velocities, vegetation dynamics, and surface conditions (soil moisture and land use) especially in the sensitive regions identified here, as well as improved ability to address small-scale convective processes producing dust via cold pool (haboob) events frequent in monsoon regimes.

Global-scale attribution of anthropogenic and natural dust sources and their emission rates based on MODIS Deep Blue aerosol products

Science.gov (United States)

Ginoux, Paul; Prospero, Joseph M.; Gill, Thomas E.; Hsu, N. Christina; Zhao, Ming

2012-09-01

Our understanding of the global dust cycle is limited by a dearth of information about dust sources, especially small-scale features which could account for a large fraction of global emissions. Here we present a global-scale high-resolution (0.1°) mapping of sources based on Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue estimates of dust optical depth in conjunction with other data sets including land use. We ascribe dust sources to natural and anthropogenic (primarily agricultural) origins, calculate their respective contributions to emissions, and extensively compare these products against literature. Natural dust sources globally account for 75% of emissions; anthropogenic sources account for 25%. North Africa accounts for 55% of global dust emissions with only 8% being anthropogenic, mostly from the Sahel. Elsewhere, anthropogenic dust emissions can be much higher (75% in Australia). Hydrologic dust sources (e.g., ephemeral water bodies) account for 31% worldwide; 15% of them are natural while 85% are anthropogenic. Globally, 20% of emissions are from vegetated surfaces, primarily desert shrublands and agricultural lands. Since anthropogenic dust sources are associated with land use and ephemeral water bodies, both in turn linked to the hydrological cycle, their emissions are affected by climate variability. Such changes in dust emissions can impact climate, air quality, and human health. Improved dust emission estimates will require a better mapping of threshold wind velocities, vegetation dynamics, and surface conditions (soil moisture and land use) especially in the sensitive regions identified here, as well as improved ability to address small-scale convective processes producing dust via cold pool (haboob) events frequent in monsoon regimes.

Land Streamer Surveying Using Multiple Sources

KAUST Repository

Mahmoud, Sherif

2014-12-11

Various examples are provided for land streamer seismic surveying using multiple sources. In one example, among others, a method includes disposing a land streamer in-line with first and second shot sources. The first shot source is at a first source location adjacent to a proximal end of the land streamer and the second shot source is at a second source location separated by a fixed length corresponding to a length of the land streamer. Shot gathers can be obtained when the shot sources are fired. In another example, a system includes a land streamer including a plurality of receivers, a first shot source located adjacent to the proximal end of the land streamer, and a second shot source located in-line with the land streamer and the first shot source. The second shot source is separated from the first shot source by a fixed overall length corresponding to the land streamer.

Natural vegetation at the proposed Reference Repository Location in southeastern Washington

International Nuclear Information System (INIS)

Rickard, W.H.

1988-02-01

The dominant shrubs were sagebrush and spiny hopsage; the herbs were dominated by cheatgrass and Sandberg bluegrass. Spiny hopsage appeared to be vulnerable to burning and also to damage by off-road vehicular traffic. It appears to have little or no ability to reproduce through seedlings; once the existing plants are killed they are not likely to be replaced, even if seed-producing plants are nearby. The only pure stand of spiny hopsage known to exist on the Hanford Site is on and near study plot 2H. Sagebrush, like spiny hopsage, is killed by burning and by heavy vehicles. Sagebrush is capable of reproducing via seeds, indicating that it is an inherently aggressive species with a capacity to reestablish itself if parent plants are in the vicinity to act as seed sources. Alien, annual plants, especially cheatgrass, were a major contributor to the herbaceous canopy cover in plots 3S, 4S, and 5S. However, native perennial grasses, especially Sandberg bluegrass, were a major contributor to the canopy cover in plots 1S and 2H. These differences are probably caused by differences in soil properties (e.g., water retention capacity), rather than to historical disturbances such as livestock grazing or wildfire. Specimens of Sandwort, Arenaria franklinii, growing near the Reference Repository Location were collected for examination by taxonomists to determine if the specimens are of the variety A. f. thompsonii, a taxon currently listed as threatened in the state of Washington. 16 refs., 7 figs., 3 tabs

Ground Motion Analysis of Co-Located DAS and Seismometer Sensors

Science.gov (United States)

Wang, H. F.; Fratta, D.; Lord, N. E.; Lancelle, C.; Thurber, C. H.; Zeng, X.; Parker, L.; Chalari, A.; Miller, D.; Feigl, K. L.; Team, P.

2016-12-01

The PoroTomo research team deployed 8700-meters of Distributed Acoustic Sensing (DAS) cable in a shallow trench and 400-meters in a borehole at Brady Hot Springs, Nevada in March 2016 together with an array of 246, three-component geophones. The seismic sensors occupied a natural laboratory 1500 x 500 x 400 meters overlying the Brady geothermal field. The DAS cable was laid out in three parallel zig-zag lines with line segments approximately 100-meters in length and geophones were spaced at approximately 50-m intervals. In several line segments, geophones were co-located within one meter of the DAS cable. Both DAS and the conventional geophones recorded continuously over 15 days. A large Vibroseis truck (T-Rex) provided the seismic source at approximately 250 locations outside and within the array. The Vibroseis protocol called for excitation in one vertical and two orthogonal horizontal directions at each location. For each mode, three, 5-to-80-Hz upsweeps were made over 20 seconds. In addition, a moderate-sized earthquake with a local magnitude of 4.3 was recorded on March 21, 2016. Its epicenter was approximately 150-km away. Several DAS line segments with co-located geophone stations were used to test relationships between the strain rate recorded by DAS and ground velocity recorded by the geophones.

Sugar cane stillage: a potential source of natural antioxidants.

Science.gov (United States)

Caderby, Emma; Baumberger, Stéphanie; Hoareau, William; Fargues, Claire; Decloux, Martine; Maillard, Marie-Noëlle

2013-11-27

Biorefinery of sugar cane is the first economic activity of Reunion Island. Some sugar cane manufactured products (juice, syrup, molasses) have antioxidant activities and are sources of both phenolic compounds and Maillard Reaction Products (MRP). The study aimed to highlight the global antioxidant activity of sugar cane stillage and understand its identity. Chromatographic fractionation on Sephadex LH-20 resin allowed the recovery of a MRP-rich fraction, responsible for 58 to 66% of the global antioxidant activity according to the nature of the sugar cane stillage (DPPH test), and a phenolic compounds-rich fraction for 37 to 59% of the activity. A good correlation was recorded between the antioxidant activity of the sugar cane stillage and its content in total reducing compounds amount (Folin-Ciocalteu assay), among them 2.8 to 3.9 g/L of phenolic compounds (in 5-caffeoylquinic acid equivalent). Preliminary experiments by HPLC-DAD-MS allowed to identify several free phenolic acids and gave clues to identify esters of quinic acids.

Several natural indicators of radial well ageing at the Belgrade groundwater source, part 1.

Science.gov (United States)

Dimkić, M; Pusić, M; Vidovic, D; Petković, A; Boreli-Zdravković, D

2011-01-01

Over time, the radial collector wells of the Belgrade Groundwater Source, located in the alluvial sediments of the Sava River, exhibit a decline in discharge and a reduction in operating efficiency due to well ageing. An increase in hydraulic losses at the lateral screens, due to chemical and biochemical clogging, has been identified as the primary cause. Certain hydrogeological, hydrochemical and microbiological parameters reflect the well-ageing process and can, therefore, be considered as its indicators. An indicator-based determination of scale is an important aspect in the selection of appropriate well locations, structural characteristics, and maintenance approaches. Well ageing was studied over a period of 5 years (2005-2009). The objective was to investigate the causes of well ageing. The correlations established between the groundwater redox potential, the total iron concentration in groundwater, the grain-size distribution of the aquifer, and well discharge, are presented in the paper.

Modeling discrete competitive facility location

CERN Document Server

Karakitsiou, Athanasia

2015-01-01

This book presents an up-to-date review of modeling and optimization approaches for location problems along with a new bi-level programming methodology which captures the effect of competition of both producers and customers on facility location decisions. While many optimization approaches simplify location problems by assuming decision making in isolation, this monograph focuses on models which take into account the competitive environment in which such decisions are made. New insights in modeling, algorithmic and theoretical possibilities are opened by this approach and new applications are possible. Competition on equal term plus competition between market leader and followers are considered in this study, consequently bi-level optimization methodology is emphasized and further developed. This book provides insights regarding modeling complexity and algorithmic approaches to discrete competitive location problems. In traditional location modeling, assignment of customer demands to supply sources are made ...

Seismic precursors of vulcanian explosions at Ubinas volcano (Peru) : Statistical analysis and source locations

Science.gov (United States)

Métaxian, J.-P.; Macedo, O.; Lengline, O.; Monteiller, V.; Taipe, E.

2009-04-01

Ubinas stratovolcano (5672 m), located 60 km east from Arequipa city is historically the most active volcano in Peru. The present eruption began on March 25th 2006. A lava plug has been observed at the bottom of the pit crater situated in the south part of the caldeira. The eruptive activity involves very brought closer exhalations rising a few hundred meters above the crater rim to larger plumes produced by explosions that may reach up to 3 kilometers. The seismic activity is characterized by high rates of long-period (LP) event production accompanying eruptive activity and very long period (VLP) events observed at the same time as vulcanian explosions. The LP and VLP events have a spectral content respectively dominated by frequencies between 2-5 Hz and 0.3-0.9 Hz. The vulcanian explosive activity is characterized by the occurrence of LP swarm preceding most of the VLPs by about 2 hours. In some occasions, the LP swarm merges into tremor about half an hour before the explosion. LPs belonging to the same swarm have similar waveform suggesting a unique source area, which could be the conduit and/or the lava plug surface. The monitoring system includes 4 seismic stations, among which one is equipped with a broadband sensor and 2 tiltmeters. In this work we analyzed a catalogue of data including more than 40000 LP events and 130 VLP events recorded between May 2006 and December 2008. The evolution of the average number of LP events preceding explosions was computed. The variation of the LP rate is clearly diverging from the background rate ~ 0.1 days before explosions. In particular, the most energetic explosions are correlated with the biggest increases of seismicity. However this general behavior is not observed for every single explosion. A direct test is now under study in order to check if the earthquake rate can be used as an alert tool for future explosions. To locate the source of LP events belonging to the swarms, we used a method based on the measurement of

Anonymity Preserving Routing In Location Privacy Schemes In Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

R Regin

2015-12-01

Full Text Available Location privacy measures need to be developed to prevent the opponent from determining the physical locations of source sensors and sinks. An opponent can easily intercept network traffic due to the use of a broadcast medium for routing packets and get detailed information such as packet transmission time and frequency to perform traffic analysis and infer the locations of monitored objects and data sinks. On the other hand, sensors usually have limited processing speed and energy supplies. It is very expensive to apply traditional anonymous communication techniques for hiding the communication between sensor nodes and sinks. The existing source-location privacy protects the location of monitored objects to increase the number of messages sent by the source before the object is located by the attacker. The flooding technique has the source node send each packet through numerous paths to a sink making it difficult for an opponent to trace the source. The locations of sinks can be protected from a local eavesdropper by hashing the ID field in the packet header. But opponent can track sinks by carrying out time correlation and rate monitoring attacks. Besides protection some source nodes are transferring relatively large amounts of data in existing system. As a result, these nodes run out of battery faster due to improper position of nodes and sinks. Thus in the proposed system the sinks should be located as optimally as possible to reduce traffic flow and energy consumption for sensor nodes. Hence Sink placement problem is resolved for minimizing the delay as well as maximizing the lifetime of a WSN. Thus proposed system is efficient in terms of overhead and functionality when compared to existing system.

Tracking the MSL-SAM methane detection source location Through Mars Regional Atmospheric Modeling System (MRAMS)

Science.gov (United States)

Pla-García, Jorge

2016-04-01

1. Introduction: The putative in situ detection of methane by Sample Analysis at Mars (SAM) instrument suite on Curiosi-ty at Gale crater has garnered significant attention because of the potential implications for the presence of geological methane sources or indigenous Martian organisms [1, 2]. SAM reported detection of back-ground levels of atmospheric methane of mean value 0.69±0.25 parts per billion by volume (ppbv) at the 95% confidence interval (CI). Additionally, in four sequential measurements spanning a 60-sol period, SAM observed elevated levels of methane of 7.2±2.1 ppbv (95% CI), implying that Mars is episodically producing methane from an additional unknown source. There are many major unresolved questions regard-ing this detection: 1) What are the potential sources of the methane release? 2) What causes the rapid decrease in concentration? and 3) Where is the re-lease location? 4) How spatially extensive is the re-lease? 5) For how long is CH4 released? Regarding the first question, the source of methane, is so far not identified. It could be related with geo-logical process like methane release from clathrates [3], serpentinisation [4] and volcanism [5]; or due to biological activity from methanogenesis [6]. To answer the second question, the rapid decrease in concentration, it is important to note that the photo-chemical lifetime of methane is of order 100 years, much longer than the atmospheric mixing time scale, and thus the gas should tend to be well mixed except near a source or shortly after an episodic release. The observed spike of 7 ppb from the background of System (MRAMS). The model was focused on rover locations using nested grids with a spacing of 330 meters on the in-nermost grid that is centered over the landing [8, 9]. MRAMS is ideally suited for this investigation; the model is explicitly designed to simulate Mars' at-mospheric circulations at the mesoscale and smaller with realistic, high-resolution surface properties [10, 11

Sodium intakes of US children and adults from foods and beverages by location of origin and by specific food source.

Science.gov (United States)

Drewnowski, Adam; Rehm, Colin D

2013-05-28

Sodium intakes, from foods and beverages, of 22,852 persons in the National Health and Nutrition Examination Surveys (NHANES 2003-2008) were examined by specific food source and by food location of origin. Analyses were based on a single 24-h recall. Separate analyses were conducted for children (6-11 years of age), adolescents (12-19), and adults (20-50 and ≥51 years). Grouping of like foods (e.g., food sources) used a scheme proposed by the National Cancer Institute, which divides foods/beverages into 96 food subgroups (e.g., pizza, yeast breads or cold cuts). Food locations of origin were stores (e.g., grocery, convenience and specialty stores), quick-service restaurant/pizza (QSR), full-service restaurant (FSR), school, or other. Food locations of sodium were also evaluated by race/ethnicity amongst adults. Stores provided between 58.1% and 65.2% of dietary sodium, whereas QSR and FSR together provided between 18.9% and 31.8% depending on age. The proportion of sodium from QSR varied from 10.1% to 19.9%, whereas that from FSR varied from 3.4% to 13.3%. School meals provided 10.4% of sodium for 6-11 year olds and 6.0% for 12-19 year olds. Pizza from QSR, the top away from home food item, provided 5.4% of sodium in adolescents. QSR pizza, chicken, burgers and Mexican dishes combined provided 7.8% of total sodium in adult diets. Most sodium came from foods purchased in stores. Food manufacturers, restaurants, and grocery stores all have a role to play in reducing the amount of sodium in the American diet.

Formation and migration of Natural Gases: gas composition and isotopes as monitors between source, reservoir and seep

Science.gov (United States)

Schoell, M.; Etiope, G.

2015-12-01

Natural gases form in tight source rocks at temperatures between 120ºC up to 200ºC over a time of 40 to 50my depending on the heating rate of the gas kitchen. Inferring from pyrolysis experiments, gases after primary migration, a pressure driven process, are rich in C2+ hydrocarbons (C2 to C5). This is consistent with gas compositions of oil-associated gases such as in the Bakken Shale which occur in immediate vicinity of the source with little migration distances. However, migration of gases along porous rocks over long distances (up to 200km in the case of the Troll field offshore Norway) changes the gas composition drastically as C2+ hydrocarbons tend to be retained/sequestered during migration of gas as case histories from Virginia and the North Sea will demonstrate. Similar "molecular fractionation" is observed between reservoirs and surface seeps. In contrast to gas composition, stable isotopes in gases are, in general, not affected by the migration process suggesting that gas migration is a steady state process. Changes in isotopic composition, from source to reservoir to surface seeps, is often the result of mixing of gases of different origins. Examples from various gas provinces will support this notion. Natural gas basins provide little opportunity of tracking and identifying gas phase separation. Future research on experimental phase separation and monitoring of gas composition and gas ratio changes e.g. various C2+ compound ratios over C1 or isomer ratios such as iso/n ratios in butane and pentane may be an avenue to develop tracers for phase separation that could possibly be applied to natural systems of retrograde natural condensate fields.

Antibiotic susceptibility profile of bacteria isolated from natural sources of water from rural areas of East Sikkim

Directory of Open Access Journals (Sweden)

Shubra Poonia

2014-01-01

Full Text Available Background: Contamination of water, food, and environment with antibiotic-resistant bacteria poses a serious public health issue. Objective: The objective was to study the bacterial pollution of the natural sources of water in east Sikkim and to determine the antimicrobial profile of the bacterial isolates. Materials and Methods: A total of 225 samples, 75 each during winter, summer, and monsoon season were collected from the same source in every season for bacteriological analysis by membrane filtration method. Antibiotic susceptibility test was performed using standard disc diffusion method. Results: A total of 19 bacterial species of the genera Escherichia, Klebsiella, Proteus, Salmonella, Shigella, Enterobacter, Citrobacter, Morganella, Pseudomonas, Acinetobacter, Flavobacterium, and Serratia were isolated and their antimicrobial sensitivity tested. Generally, most bacterial isolates except Salmonella and Shigella species were found resistant to commonly used antibiotics such as ampicillin (57.5%, trimethoprim/sulfamethoxaole (39.1%, amoxicillin/clavulanic acid (37.4%, cefixime (34.5%, tetracycline (29.1%, ceftazidime (26.3%, ofloxacin (25.9%, amikacin (8.7%, and gentamicin (2.7% but sensitive to imipenem and piperacillin/tazobactam. Conclusion: Natural sources of water in east Sikkim are grossly contaminated with bacteria including enteropathogens. The consumption of untreated water from these sources might pose health risk to consumers.

Reducing errors in aircraft atmospheric inversion estimates of point-source emissions: the Aliso Canyon natural gas leak as a natural tracer experiment

Science.gov (United States)

Gourdji, S. M.; Yadav, V.; Karion, A.; Mueller, K. L.; Conley, S.; Ryerson, T.; Nehrkorn, T.; Kort, E. A.

2018-04-01

Urban greenhouse gas (GHG) flux estimation with atmospheric measurements and modeling, i.e. the ‘top-down’ approach, can potentially support GHG emission reduction policies by assessing trends in surface fluxes and detecting anomalies from bottom-up inventories. Aircraft-collected GHG observations also have the potential to help quantify point-source emissions that may not be adequately sampled by fixed surface tower-based atmospheric observing systems. Here, we estimate CH4 emissions from a known point source, the Aliso Canyon natural gas leak in Los Angeles, CA from October 2015–February 2016, using atmospheric inverse models with airborne CH4 observations from twelve flights ≈4 km downwind of the leak and surface sensitivities from a mesoscale atmospheric transport model. This leak event has been well-quantified previously using various methods by the California Air Resources Board, thereby providing high confidence in the mass-balance leak rate estimates of (Conley et al 2016), used here for comparison to inversion results. Inversions with an optimal setup are shown to provide estimates of the leak magnitude, on average, within a third of the mass balance values, with remaining errors in estimated leak rates predominantly explained by modeled wind speed errors of up to 10 m s‑1, quantified by comparing airborne meteorological observations with modeled values along the flight track. An inversion setup using scaled observational wind speed errors in the model-data mismatch covariance matrix is shown to significantly reduce the influence of transport model errors on spatial patterns and estimated leak rates from the inversions. In sum, this study takes advantage of a natural tracer release experiment (i.e. the Aliso Canyon natural gas leak) to identify effective approaches for reducing the influence of transport model error on atmospheric inversions of point-source emissions, while suggesting future potential for integrating surface tower and

Analysis of the rate setting system on Russia population exposure limitation by natural irradiation sources

International Nuclear Information System (INIS)

Stamat, I.P.

2009-01-01

In this work the condition of the legal securing of radiation safety system for the population of Russia under the influence of natural sources of radiation was analyzed. The system had been created during the latter 30 years. The ways of its improvement and harmonization according to the recommendations of authoritative organization were examined

Patterns of ice nuclei from natural water sources in the mountains of Tirol, Austria

Science.gov (United States)

Baloh, Philipp; Hanlon, Regina; Pietsch, Renee; Anderson, Christopher; Schmale, David G., III; Grothe, Hinrich

2017-04-01

Heterogeneous ice nucleation—the process by which particles can nucleate ice between 0 and -35°C—is important for generating artificial snow. Though abiotic and biotic ice nuclei are present in many different natural and managed ecosystems, little is known about their nature, sources, and ecological roles. We collected samples of water and snow from the mountains of Tyrol, Austria in June, July, and November, 2016. The collected water was mostly from sources with minimal anthropogenic pollution, since most of the water from the sampled streams came from glacial melt. The samples were filtered through a 0.22μm filter, and microorganisms were cultured on different types of media. Resulting colonies were tested for their ice nucleation ability using a droplet freezing assay and identified to the level of the species. The unfiltered water and the filtered water will be subjected to additional assays using cryo microscopy and vibrational microscopy (IR and Raman- spectroscopy). Preliminary analyses suggested that the percentage of ice-nucleating microbes varied with season; greater percentages of ice nucleating microbes were present during colder months. The glacial melt also varies strongly over the year with the fraction of mineral dust suspended in it which serves as an inorganic ice nucleation agent. Further investigation of these samples may help to show the combined ice nuleation abilities of biological and non biological particles present in the mountains of Tirol, Austria. Future work may shed light on how the nucleation properties of the natural water changes with the time of the year and what may be responsible for these changes.

Radiological Impact of artificial and naturally radiation sources. Report of the UNSCEAR, 2008

International Nuclear Information System (INIS)

Cancio, David

2010-01-01

Results in the report of the Scientific Committee of the United Nations for Study of the Effects of Atomic Radiations, presented in the 56th period of sessions in July 2008; values obtained from natural sources or from artificial ones are compared and, in accordance with their effects on humans. It is concluded that the most significant change in the situation, between reports, has been the increase in the medical exposure due to the increase in the number of computed tomography examinations. (author)

Characterization of noise sources in nuclear power reactors

International Nuclear Information System (INIS)

Andhill, Gustav

2004-03-01

Algorithms for unfolding noise sources in nuclear power reactors are investigated. No preliminary knowledge of the functional form of the space dependence is assumed in contrast to the usual methods. The advantage of this is that the algorithms can be applied to various noise sources and the results can be interpreted without expert knowledge. The results can therefore be directly displayed to the plant operators. The precision will however be lower than that of the traditional methods because of the arbitrariness in the type of the noise source. Two different reactor models are studied. First a simple one-dimensional and homogeneous core is considered. Three methods for finding the noise source from the measured flux noise are investigated here. The first one is based on the inversion of an appropriate pre-calculated noise source-to-measured induced neutron noise transfer function. The second one relies on the use of the measured neutron noise as the solution of the equations giving the neutron noise induced by a given noise source. The advantage of this second method is that the noise source can be determined directly, i.e., without any Inversion of a transfer function. The second method is thus called the direct method. The last method is based on a reconstruction of the noise source by spatial Fourier expansion. The two latter techniques are found usable for different locations of the actual noise source in the 1D core. They are therefore tried on more sophisticated two-dimensional models of cores. The direct method is able both to determine the nature of the noise source and its location in 2D

Characterization of noise sources in nuclear power reactors

Energy Technology Data Exchange (ETDEWEB)

Andhill, Gustav

2004-03-01

Algorithms for unfolding noise sources in nuclear power reactors are investigated. No preliminary knowledge of the functional form of the space dependence is assumed in contrast to the usual methods. The advantage of this is that the algorithms can be applied to various noise sources and the results can be interpreted without expert knowledge. The results can therefore be directly displayed to the plant operators. The precision will however be lower than that of the traditional methods because of the arbitrariness in the type of the noise source. Two different reactor models are studied. First a simple one-dimensional and homogeneous core is considered. Three methods for finding the noise source from the measured flux noise are investigated here. The first one is based on the inversion of an appropriate pre-calculated noise source-to-measured induced neutron noise transfer function. The second one relies on the use of the measured neutron noise as the solution of the equations giving the neutron noise induced by a given noise source. The advantage of this second method is that the noise source can be determined directly, i.e., without any Inversion of a transfer function. The second method is thus called the direct method. The last method is based on a reconstruction of the noise source by spatial Fourier expansion. The two latter techniques are found usable for different locations of the actual noise source in the 1D core. They are therefore tried on more sophisticated two-dimensional models of cores. The direct method is able both to determine the nature of the noise source and its location in 2D.

Directed Thermal Diffusions through Metamaterial Source Illusion with Homogeneous Natural Media

Directory of Open Access Journals (Sweden)

Guoqiang Xu

2018-04-01

Full Text Available Owing to the utilization of transformation optics, many significant research and development achievements have expanded the applications of illusion devices into thermal fields. However, most of the current studies on relevant thermal illusions used to reshape the thermal fields are dependent of certain pre-designed geometric profiles with complicated conductivity configurations. In this paper, we propose a methodology for designing a new class of thermal source illusion devices for achieving directed thermal diffusions with natural homogeneous media. The employments of the space rotations in the linear transformation processes allow the directed thermal diffusions to be independent of the geometric profiles, and the utilization of natural homogeneous media improve the feasibility. Four schemes, with fewer types of homogeneous media filling the functional regions, are demonstrated in transient states. The expected performances are observed in each scheme. The related performance are analyzed by comparing the thermal distribution characteristics and the illusion effectiveness on the measured lines. The findings obtained in this paper see applications in the development of directed diffusions with minimal thermal loss, used in novel “multi-beam” thermal generation, thermal lenses, solar receivers, and waveguide.

Plant-Derived Natural Products as Sources of Anti-Quorum Sensing Compounds

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Kok-Gan Chan

2013-05-01

Full Text Available Quorum sensing is a system of stimuli and responses in relation to bacterial cell population density that regulates gene expression, including virulence determinants. Consequently, quorum sensing has been an attractive target for the development of novel anti-infective measures that do not rely on the use of antibiotics. Anti-quorum sensing has been a promising strategy to combat bacterial infections as it is unlikely to develop multidrug resistant pathogens since it does not impose any selection pressure. A number of anti-quorum sensing approaches have been documented and plant-based natural products have been extensively studied in this context. Plant matter is one of the major sources of chemicals in use today in various industries, ranging from the pharmaceutical, cosmetic, and food biotechnology to the textile industries. Just like animals and humans, plants are constantly exposed to bacterial infections, it is therefore logical to expect that plants have developed sophisticated of chemical mechanisms to combat pathogens. In this review, we have surveyed the various types of plant-based natural products that exhibit anti-quorum sensing properties and their anti-quorum sensing mechanisms.

Micro-seismic Imaging Using a Source Independent Waveform Inversion Method

KAUST Repository

Wang, Hanchen

2016-04-18

Overthrust model. On the other hand, a new imaging condition of natural Green’s function has been implemented to mitigate the effect of the unknown velocity model. It is based on putting receivers in a horizontal well close to the micro-seismic events so that only a small part of the velocity model is required for the imaging. In order to focus the multi scattering energy to the source location, as well as to suppress the influence of the noise in the data, we introduced a new method to compensate the energy in the receiver wavefield. It is based on reflection waveform inversion (RWI) theory. We simply migrate for the scatters (reflectors) in the medium, and set the image as a secondary source to compensate for the multi scattering energy in the receiver wavefield. By applying the same imaging condition, the energy of those scattering events can be traced to the source location. Thus the source point has higher energy in the source image. A simple two-layer medium test demonstrates the features.

Natural radiation

International Nuclear Information System (INIS)

Feliciano, Vanusa Maria Delage

2016-01-01

Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included

Analysis of Shade Matching in Natural Dentitions Using Intraoral Digital Spectrophotometer in LED and Filtered LED Light Sources.

Science.gov (United States)

Chitrarsu, Vijai Krishnan; Chidambaranathan, Ahila Singaravel; Balasubramaniam, Muthukumar

2017-10-31

To evaluate the shade matching capabilities in natural dentitions using Vita Toothguide 3D-Master and an intraoral digital spectrophotometer (Vita Easyshade Advance 4.0) in various light sources. Participants between 20 and 40 years old with natural, unrestored right maxillary central incisors, no history of bleaching, orthodontic treatment, or malocclusion and no rotations were included. According to their shades, subjects were randomly selected and grouped into A1, A2, and A3. A total of 100 participants (50 male and 50 female) in each group were chosen for this study. Shade selection was made between 10 am and 2 pm for all light sources. The same examiner selected the shade of natural teeth with Vita Toothguide 3D-Master under natural light within 2 minutes. Once the Vita Toothguide 3D-Masterwas matched with the maxillary right central incisor, the L*, a*, and b* values, chroma, and hue were recorded with Vita Easyshade Advance 4.0 by placing it on the shade tab under the same light source. The values were statistically analyzed using one-way ANOVA and Tukey's HSD post hoc test with SPSS v22.0 software. The mean ∆E* ab values for shades A1, A2, and A3 for groups 1, 2, and 3 were statistically significantly different from each other (p spectrophotometer showed statistically significant differences in shade matching compared to Vita Toothguide 3D-Master. Incandescent light showed more accurate shade matching than the filtered LED, LED, and daylight. © 2017 by the American College of Prosthodontists.

Documentary Letters of Credit, Legal Nature and Sources of Law

Directory of Open Access Journals (Sweden)

Alavi Hamed

2016-06-01

Full Text Available There is no doubt about risky nature of international trade. Such risk can be conceptualized as country risk, transportation risk, customer risk and etc. Documentary Letters of Credit (LC are used as a method of payment in international business for many centuries in order to reduce risk of trade specially when parties are located in different countries and do not have precise information from financial standing of each other. In such occasion LC will reduce the risk of trade by shifting payment obligation from buyer as an individual to a payment guarantee of a bank as a legal entity in return for presentation of complying documents with terms of credit by seller. Familiarity with legal nature and different legal frameworks which govern the international operation of documentary letters of credit can facilitate the process of international trade for businessmen and boost national economies. However, lack of knowledge about them can impose huge losses on international traders. Situation will be more complicated when we understand that there are many internationally recognized legal frameworks which can affect the operation of LC and they get frequently updated in order to address technological and economic developments in global market. In this paper, author tries to answer questions regarding (i what are international legal frameworks governing operation of documentary letters of credit? (ii which areas of LC operation has been covered by them and (iii how do they address the legal questions regarding international operation of documentary letters of credit?

Wind as a feasible alternative source for improving the deficiency of hydroelectricity in Tanzania

International Nuclear Information System (INIS)

Kainkwa, R. M.

2006-01-01

Hydroelectricity is the main source of electricity in Tanzania since about 86% of the electricity generated is from this source. During the dry season there is normally a storage of water in the dams and as such the electricity generated is below the demand. In 2004 a natural gas power plant was inaugurated to alleviate this shortage of electricity. When generating electricity from natural gas, exotic gases are emitted which pollute our environment. This source of energy also cannot regenerate itself within the human life scale. Wind is a renewable source that can be used to supplement the shortage of hydroelectricity in Tanzania. Wind speed data collected from a location with high wind energy potential shows that electricity can be generated from the wind to alleviate this shortage of hydroelectricity. Wind and rainfall data demonstrate further that the windy season, which is from July to November coincide with the dry season in which the use of wind energy in electric generation can help to fill the gap of the hydroelectricity that prevails during that season. The use of wind instead of natural gas will reduce the environmental pollution that results from extracting energy from the fossil fuel source.(Author)

Ground source heat pumps versus high efficiency natural gas furnaces in Alberta

Energy Technology Data Exchange (ETDEWEB)

Shaw, J.

2003-02-02

For the past twenty years or so, the heating and cooling of numerous buildings in northern Europe has been accomplished using ground source heat pumps (GSHPs), while in North America they have been in use for approximately ten years. In the Prairies, natural gas furnaces dominate, while GSHP are more popular in eastern Canada. The author noted that natural gas furnaces have an efficiency of 80 per cent or less, while high efficiency natural gas (HENG) furnaces, more expensive, have an efficiency in the 90 per cent range. A brief outline of the principles behind GSHPs was provided. The Coefficient of Performance (COP) of GSHP reaches up to 500 per cent depending whether the unit is cooling or heating. The amount of heat produced by a heating system expressed as a percentage of the energy input required to operate the system is the definition used for the efficiency. In those cases where it is possible to amortize the initial costs, pay now or obtain a subsidy, the installation of GSHP is advantageous. Several factors affect the total cost of heating a building, such as the airtightness of the building and its insulation, the coldness of the climate, and the inside controlled temperature setting. The author then examined the cost of operating a GSHP versus a natural gas furnace. In most examples studied, the cost of operating a GSHP was less than the cost of operating a natural gas furnace. The Total Equivalent Warming Impact (TEWI) of GSHPs and HENG furnaces was examined. The author concluded that the cost of heating by GSHP in Alberta will be lower than the cost of heating by HENG which requires a separate air conditioning unit for the summer months, with additional improvements in efficiency and insulation. 7 refs., 4 tabs.

What do we really know about the health effects of natural sources of trans fatty acids?

Science.gov (United States)

While the food industry remains actively engaged in the development of alternatives for partially hydrogenated vegetable oils in order to reduce intake of trans fatty acids, intake of these fatty acids from natural sources remains as a small part of our diet. The question remains, are there differ...

Issues of assessment of doses from natural sources in working conditions: implications for the unified state system of individual dose monitoring

Directory of Open Access Journals (Sweden)

T. A. Kormanovskaya

2017-01-01

Full Text Available The aims of the work are: 1 an analysis of information on radiation doses from natural sources of ionizing radiation of employees of enterprises in some industries of the Russian Federation and 2 an assessment of the state of registration of doses from natural sources in working conditions in the Unified System of Individual Dose Control. Materials and methods. The analysis was performed on the results of the operation of the Federal database of radiation doses of the population due to natural and artificial radiation background in 2013–2015 on the basis of the forms of the Federal statistical observation No. 4-DOZ in terms of collecting information on the radiation doses of workers in some non-nuclear industries due to natural sources of ionizing radiation. Results. Analysis of enterprises in 17 industries in 23 regions of Russia connected with the specificity of production processes showed cases of natural exposure of workers at the dose level exceeding 5 mSv/year. We have identified those branches of industry, for which the doses were close to 5 mSv/year.Examples of reducing the radiation doses by reducing the time spent by workers in workplaces with high levels of radiation are given. The problems of insufficient representativeness of the sample data are due to the lack of interaction of the management of industrial enterprises with the bodies of the Rospotrebnadzor. The obtained data allow speaking about the problem of assessing the quality of radiation control in the organizations where additional exposure of workers from natural radiation sources is expected. It is necessary to create a system of regulatory and procedural documents to solve the problem at the national level.

Vehicle-based Methane Mapping Helps Find Natural Gas Leaks and Prioritize Leak Repairs

Science.gov (United States)

von Fischer, J. C.; Weller, Z.; Roscioli, J. R.; Lamb, B. K.; Ferrara, T.

2017-12-01

Recently, mobile methane sensing platforms have been developed to detect and locate natural gas (NG) leaks in urban distribution systems and to estimate their size. Although this technology has already been used in targeted deployment for prioritization of NG pipeline infrastructure repair and replacement, one open question regarding this technology is how effective the resulting data are for prioritizing infrastructure repair and replacement. To answer this question we explore the accuracy and precision of the natural gas leak location and emission estimates provided by methane sensors placed on Google Street View (GSV) vehicles. We find that the vast majority (75%) of methane emitting sources detected by these mobile platforms are NG leaks and that the location estimates are effective at identifying the general location of leaks. We also show that the emission rate estimates from mobile detection platforms are able to effectively rank NG leaks for prioritizing leak repair. Our findings establish that mobile sensing platforms are an efficient and effective tool for improving the safety and reducing the environmental impacts of low-pressure NG distribution systems by reducing atmospheric methane emissions.

A suggested guideline for exposure control from natural radioactivity in future buildings

International Nuclear Information System (INIS)

Nambi, K.S.V.; Shukla, V.K.

1991-01-01

Naturally occurring radionuclides in building materials are one of the sources of radiation exposure to the population. Their concentrations vary by about 2 to 3 orders of magnitude at different geographical locations. This paper proposes three control methodologies for keeping the population exposure as low as reasonably achievable. Tentative recommendations are also included. (author). 11 refs., 3 tabs., 2 appendixes

Magnitudes and sources of precipitation and dry deposition fluxes of industrial and natural leads to the North Pacific at Enewetak

International Nuclear Information System (INIS)

Settle, D.M.; Patterson, C.C.

1982-01-01

A total atmospheric PB input flux of 7 ng Pb cm - 2 yr - 1 was measured in the North Pacific Easterlies at Enewetak. Parameters used to measure this flux were ratio of dry deposition flux to precipitation flux; Pb/ 210 Pb in precipitation and seawater; 210 Pb flux; washout factor; and Pb concentrations in air, rain, and dry deposition deposits. Relations among these parameters estabilished at Enewetak were used to recompute and comfirm previous estimates of lead fluxes to the oceans (ng Pb cm - 2 yr - 1 ) at the following locations: North Altantic Westerlies, 170; North Pacific Westerlies, 50; and South Pacific Easterlies, 3. Prehistoric lead output fluxes to sediments (ng Pb cm - 2 yr - 1 ) at these locations have been previously measured and were 4 (Enewetak); 30 North Atlantic Westerlies; 3 North Pacific Westerlies; 4 South Pacific Easterlies. These data show that the rates of atmospheric imputs of lead to the oceans vary directly with variations in rates of upwind emission of industrial lead from urban complexes on land. In the North Pacific and North Atlantic, present rates of atmospheric lead inputs are 10-fold greater than prehistoric outputs. In equatorial regions, present inputs and past outputs are more nearly equal. These observations disclose the effects of intense industrial atmospheric emissions of lead in the northern hemisphere westerlies which have overwhelmed prehistoric natural fluxes of lead to the oceans. The average concentration of lead in marine air at Enewetak is 170n pg m - 3 and varies less than a factor of 2 from that mean. One to 15% of this lead comes from seaspray, while the remainder comes from sources on land. About 90% of the seaspray lead is industrial, while 80 to 99% of that originating from land sources is industrial. Concentrations of lead in rain at Enewetak range from 6 to 63 pg/g with a mean value of 28

The Reduction of Vertical Interchannel Crosstalk: The Analysis of Localisation Thresholds for Natural Sound Sources

Directory of Open Access Journals (Sweden)

Rory Wallis

2017-03-01

Full Text Available In subjective listening tests, natural sound sources were presented to subjects as vertically-oriented phantom images from two layers of loudspeakers, ‘height’ and ‘main’. Subjects were required to reduce the amplitude of the height layer until the position of the resultant sound source matched that of the same source presented from the main layer only (the localisation threshold. Delays of 0, 1 and 10 ms were applied to the height layer with respect to the main, with vertical stereophonic and quadraphonic conditions being tested. The results of the study showed that the localisation thresholds obtained were not significantly affected by sound source or presentation method. Instead, the only variable whose effect was significant was interchannel time difference (ICTD. For ICTD of 0 ms, the median threshold was −9.5 dB, which was significantly lower than the −7 dB found for both 1 and 10 ms. The results of the study have implications both for the recording of sound sources for three-dimensional (3D audio reproduction formats and also for the rendering of 3D images.

Oil pollution and microbiological quality of groundwater at the location of the water source 'Ratno ostrvo' nearby Novi Sad

International Nuclear Information System (INIS)

Petrovic, O.; Simeunovic, J.; Radnovic, D.; Matavulj, M.; Gajin, S.

2002-01-01

The 'Ratno ostrvo' is the biggest drinking water source in wider area of Novi Sad. It is located on the left bank of the river Danube near the Oil Refinery 'Novi Sad'. One of the consequences of the NATO bombing of the Oil Refinery 'Novi Sad' (which is placed in hinterland of the water source) was the uncontrolled spillage of crude oil and oil derivatives. Because of that, microbiological examinations of groundwaters, from both ecological and sanitary aspects were carried out simultaneously during post-war period. Microbiological analyses from sanitary aspects show very low number of coliform bacteria. Determination of numbers of bacteria of the investigated physiological groups, revealed that there was a constant relatively high number of oil-, phenol oxidizing and lipolytic bacteria which are indicators this kind of specific pollution. Microbiological analysis of oil polluted soil show presence relatively high number of different groups of bacteria. In spite of changed ecological situation caused by war effects, microbiological analyses of groundwater quality showed satisfactory results in source 'Ratno ostrvo' by now. The presence and potential activity of indigenous microflora could be utilized in recultivation processes in examined area. (author)

Determining the source and genetic fingerprint of natural gases using noble gas geochemistry: a northern Appalachian Basin case study

Science.gov (United States)

Hunt, Andrew G.; Darrah, Thomas H.; Poreda, Robert J.

2012-01-01

Silurian and Devonian natural gas reservoirs present within New York state represent an example of unconventional gas accumulations within the northern Appalachian Basin. These unconventional energy resources, previously thought to be noneconomically viable, have come into play following advances in drilling (i.e., horizontal drilling) and extraction (i.e., hydraulic fracturing) capabilities. Therefore, efforts to understand these and other domestic and global natural gas reserves have recently increased. The suspicion of fugitive mass migration issues within current Appalachian production fields has catalyzed the need to develop a greater understanding of the genetic grouping (source) and migrational history of natural gases in this area. We introduce new noble gas data in the context of published hydrocarbon carbon (C1,C2+) (13C) data to explore the genesis of thermogenic gases in the Appalachian Basin. This study includes natural gases from two distinct genetic groups: group 1, Upper Devonian (Marcellus shale and Canadaway Group) gases generated in situ, characterized by early mature (13C[C1  C2][13C113C2]: –9), isotopically light methane, with low (4He) (average, 1  103 cc/cc) elevated 4He/40Ar and 21Ne/40Ar (where the asterisk denotes excess radiogenic or nucleogenic production beyond the atmospheric ratio), and a variable, atmospherically (air-saturated–water) derived noble gas component; and group 2, a migratory natural gas that emanated from Lower Ordovician source rocks (i.e., most likely, Middle Ordovician Trenton or Black River group) that is currently hosted primarily in Lower Silurian sands (i.e., Medina or Clinton group) characterized by isotopically heavy, mature methane (13C[C1 – C2] [13C113C2]: 3), with high (4He) (average, 1.85  103 cc/cc) 4He/40Ar and 21Ne/40Ar near crustal production levels and elevated crustal noble gas content (enriched 4He,21Ne, 40Ar). Because the release of each crustal noble gas (i.e., He, Ne, Ar

Shallow Aquifer Methane Gas Source Assessment

Science.gov (United States)

Coffin, R. B.; Murgulet, D.; Rose, P. S.; Hay, R.

2014-12-01

Shale gas can contribute significantly to the world's energy demand. Hydraulic fracturing (fracking) on horizontal drill lines developed over the last 15 years makes formerly inaccessible hydrocarbons economically available. From 2000 to 2035 shale gas is predicted to rise from 1% to 46% of the total natural gas for the US. A vast energy resource is available in the United States. While there is a strong financial advantage to the application of fracking there is emerging concern about environmental impacts to groundwater and air quality from improper shale fracking operations. Elevated methane (CH4) concentrations have been observed in drinking water throughout the United States where there is active horizontal drilling. Horizontal drilling and hydraulic-fracturing can increase CH4 transport to aquifers, soil and the vadose zone. Seepage can also result from casing failure in older wells. However, there is strong evidence that elevated CH4 concentrations can be associated with topographic and hydrogeologic features, rather than shale-gas extraction processes. Carbon isotope geochemistry can be applied to study CH4source(s) in shallow vadose zone and groundwater systems. A preliminary TAMU-CC isotope data set from samples taken at different locations in southern Texas shows a wide range of CH4 signatures suggesting multiple sources of methane and carbon dioxide. These data are interpreted to distinguish regions with methane contributions from deep-sourced horizontal drilling versus shallow system microbial production. Development of a thorough environmental assessment using light isotope analysis can provide understanding of shallow anthropogenic versus natural CH4sources and assist in identifying regions that require remedial actions.

Natural Products from Mangrove Actinomycetes

Science.gov (United States)

Xu, Dong-Bo; Ye, Wan-Wan; Han, Ying; Deng, Zi-Xin; Hong, Kui

2014-01-01

Mangroves are woody plants located in tropical and subtropical intertidal coastal regions. The mangrove ecosystem is becoming a hot spot for natural product discovery and bioactivity survey. Diverse mangrove actinomycetes as promising and productive sources are worth being explored and uncovered. At the time of writing, we report 73 novel compounds and 49 known compounds isolated from mangrove actinomycetes including alkaloids, benzene derivatives, cyclopentenone derivatives, dilactones, macrolides, 2-pyranones and sesquiterpenes. Attractive structures such as salinosporamides, xiamycins and novel indolocarbazoles are highlighted. Many exciting compounds have been proven as potential new antibiotics, antitumor and antiviral agents, anti-fibrotic agents and antioxidants. Furthermore, some of their biosynthetic pathways have also been revealed. This review is an attempt to consolidate and summarize the past and the latest studies on mangrove actinomycetes natural product discovery and to draw attention to their immense potential as novel and bioactive compounds for marine drugs discovery. PMID:24798926

Factoring out natural and indirect human effects on terrestrial carbon sources and sinks

Energy Technology Data Exchange (ETDEWEB)

Canadell, J.G. [Global Carbon Project, CSIRO Marine and Atmospheric Research, GPO Box 3023, Canberra, ACT 2601 (Australia); Kirschbaum, M.U.F. [Environmental Biology Group, RSBS, Australian National University, GPO Box 475, Canberra, ACT 2601 (Australia); Kurz, W.A. [Natural Resources Canada, Canadian Forest Service, 506 West Burnside Road, Victoria, BC V8Z 1M5 (Canada); Sanz, M.J. [Fundacion CEAM, Parque Tecnologico, Charles H. Darwin 14, 46980 Paterna, Valencia (Spain); Schlamadinger, B. [Joanneum Research, Elisabethstrasse 11, Graz A-8010 (Austria); Yamagata, Y. [Center for Global Environmental Research, National Institute of Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506 (Japan)

2007-06-15

The capacity to partition natural, indirect, and direct human-induced effects on terrestrial carbon (C) sources and sinks is necessary to be able to predict future terrestrial C dynamics and thus their influence on atmospheric CO2 growth. However, it will take a number of years before we can better attribute quantitative estimates of the contribution of various C processes to the net C balance. In a policy context, factoring out natural and indirect human-induced effects on C sources and sinks from the direct human-induced influences, is seen as a requirement of a C accounting approach that establishes a clear and unambiguous connection between human activities and the assignment of C credits and debits. We present options for factoring out various groups of influences including climate variability, CO2 and N fertilization, and legacies from forest management. These are: (1) selecting longer accounting or measurement periods to reduce the effects of inter-annual variability; (2) correction of national inventories for inter-annual variability; (3) use of activity-based accounting and C response curves; (4) use of baseline scenarios or benchmarks at the national level; (5) stratification of the landscape into units with distinct average C stocks. Other, more sophisticated modeling approaches (e.g., demographic models in combination with forest inventories; process-based models) are possible options for future C accounting systems but their complexity and data requirements make their present adoption more difficult in an inclusive international C accounting system.

Factoring out natural and indirect human effects on terrestrial carbon sources and sinks

International Nuclear Information System (INIS)

Canadell, J.G.; Kirschbaum, M.U.F.; Kurz, W.A.; Sanz, M.J.; Schlamadinger, B.; Yamagata, Y.

2007-01-01

The capacity to partition natural, indirect, and direct human-induced effects on terrestrial carbon (C) sources and sinks is necessary to be able to predict future terrestrial C dynamics and thus their influence on atmospheric CO2 growth. However, it will take a number of years before we can better attribute quantitative estimates of the contribution of various C processes to the net C balance. In a policy context, factoring out natural and indirect human-induced effects on C sources and sinks from the direct human-induced influences, is seen as a requirement of a C accounting approach that establishes a clear and unambiguous connection between human activities and the assignment of C credits and debits. We present options for factoring out various groups of influences including climate variability, CO2 and N fertilization, and legacies from forest management. These are: (1) selecting longer accounting or measurement periods to reduce the effects of inter-annual variability; (2) correction of national inventories for inter-annual variability; (3) use of activity-based accounting and C response curves; (4) use of baseline scenarios or benchmarks at the national level; (5) stratification of the landscape into units with distinct average C stocks. Other, more sophisticated modeling approaches (e.g., demographic models in combination with forest inventories; process-based models) are possible options for future C accounting systems but their complexity and data requirements make their present adoption more difficult in an inclusive international C accounting system

Curcumin, a Compound from Natural Sources, a True Scientific Challenge - A Review.

Science.gov (United States)

Stanić, Zorka

2017-03-01

Curcumin, a plant-derived polyphenolic compound, naturally present in turmeric (Curcuma longa), has been the subject of intensive investigations on account of its various activities. The implementation of safe, beneficial and highly functional compounds from natural sources in human nutrition/prevention/therapy requires some modifications in order to achieve their multi-functionality, improve their bioavailability and delivery strategies, with the main aim to enhance their effectiveness. The low aqueous solubility of curcumin, its rapid metabolism and elimination from the body, and consequently, poor bioavailability, constitute major obstacles to its application. The main objectives of this review are related to reported strategies to overcome these limitations and, thereby, improve the solubility, stability and bioavailability of curcumin. The effectiveness of curcumin could be greatly improved by using nanoparticle-based carriers. The significance of the quality of a substance delivery system is reflected in the fact that carrying curcumin as a food additive/nutrition also means carrying the active biological product/drug. This review summarizes the state of the art, and highlights some examples and the most significant advances in the field of curcumin research.

The Impact of Location and Proximity on Consumers' Willingness to Pay for Green Electricity: The Case of West Virginia

Science.gov (United States)

Nkansah, Kofi

choices with utility models. WTP for energy source and proximity attribute levels were computed using parameter estimates from these utility models. Statistically different models were developed for each county. Results from the study showed that respondents in both counties had preferences for electricity generated from wind compared to natural gas. A majority of the sampled populations chose the wind option, 62.0% in Monongalia County and 60.0% in Grant County. The sampled populations in Monongalia and Grant Counties were willing to pay a weighted mean of 21.59 and 9.87 per month, respectively, for 10% of their electricity to be generated from wind over natural gas. Despite this large difference, county level means were not statistically different. On aggregate, a positive social benefit per year would be derived from generating 10% of electricity supplied to consumers in Monongalia County (2.5 million) and Grant County (186 thousand) from wind relative to natural gas. Similarly, the most social benefit would be derived from siting wind turbines at "far" locations from residents in both counties. Both county level sampled populations were willing to pay a higher premium to site wind turbines or a natural gas-fired power plant at the farthest location relative to the baseline location (near a respondent's current residence). Grant County respondents were willing to pay a slightly higher positive premium (mean of 11.71 per month) to site wind turbines at the farthest location than respondents in Monongalia County (mean of 10.14 per month). The mean WTP to site a natural gas-fired power plant at the farthest location in Monongalia County (13.06) and Grant County (13.47) were not statistically different from each other. Results from this study suggest that the decision for an outright repeal of the ARPS bill was flawed. Based on Monongalia and Grant County populations, there are social benefits derived from generating 10% of the electricity supplied to consumers in West

A global health problem caused by arsenic from natural sources

Energy Technology Data Exchange (ETDEWEB)

Ng, J.C.; Wang, J.P.; Shraim, A. [University of Queensland, Brisbane, Qld. (Australia). National Research Center for Environmental Toxicology

2003-09-01

Arsenic is a carcinogen to both humans and animals. Arsenicals have been associated with cancers of the skin, lung, and bladder. Clinical manifestations of chronic arsenic poisoning include non-cancer end point of hyper- and hypo-pigmentation, keratosis, hypertension, cardiovascular diseases and diabetes. Epidemiological evidence indicates that arsenic concentration exceeding 50 {mu}g l{sup -1} in the drinking water is not public health protective. The current WHO recommended guideline value for arsenic in drinking water is 10 {mu}g l{sup -1}, whereas many developing countries are still having a value of 50 {mu}g 1{sup -1}. It has been estimated that tens of millions of people are at risk exposing to excessive levels of arsenic from both contaminated water and arsenic-bearing coal from natural sources. The global health implication and possible intervention strategies were also discussed in this review article.

Nature's palette: the search for natural blue colorants.

Science.gov (United States)

Newsome, Andrew G; Culver, Catherine A; van Breemen, Richard B

2014-07-16

The food and beverage industry is seeking to broaden the palette of naturally derived colorants. Although considerable effort has been devoted to the search for new blue colorants in fruits and vegetables, less attention has been directed toward blue compounds from other sources such as bacteria and fungi. The current work reviews known organic blue compounds from natural plant, animal, fungal, and microbial sources. The scarcity of blue-colored metabolites in the natural world relative to metabolites of other colors is discussed, and structural trends common among natural blue compounds are identified. These compounds are grouped into seven structural classes and evaluated for their potential as new color additives.

Plutonium in nature; Le plutonium dans la nature

Energy Technology Data Exchange (ETDEWEB)

Madic, C.

1994-12-31

Plutonium in nature comes from natural sources and anthropogenic ones. Plutonium at the earth surface comes principally from anthropogenic sources. It is easily detectable in environment. The plutonium behaviour in environment is complex. It seems necessary for the future to reduce releases in environment, to improve predictive models of plutonium behaviour in geosphere, to precise biological impact of anthropogenic plutonium releases.

Biosynthesis, natural sources, dietary intake, pharmacokinetic properties, and biological activities of hydroxycinnamic acids.

Science.gov (United States)

El-Seedi, Hesham R; El-Said, Asmaa M A; Khalifa, Shaden A M; Göransson, Ulf; Bohlin, Lars; Borg-Karlson, Anna-Karin; Verpoorte, Rob

2012-11-07

Hydroxycinnamic acids are the most widely distributed phenolic acids in plants. Broadly speaking, they can be defined as compounds derived from cinnamic acid. They are present at high concentrations in many food products, including fruits, vegetables, tea, cocoa, and wine. A diet rich in hydroxycinnamic acids is thought to be associated with beneficial health effects such as a reduced risk of cardiovascular disease. The impact of hydroxycinnamic acids on health depends on their intake and pharmacokinetic properties. This review discusses their chemistry, biosynthesis, natural sources, dietary intake, and pharmacokinetic properties.

Atmospheric Precipitations, Hailstone and Rainwater, as a Novel Source of Streptomyces Producing Bioactive Natural Products

Science.gov (United States)

Sarmiento-Vizcaíno, Aida; Espadas, Julia; Martín, Jesús; Braña, Alfredo F.; Reyes, Fernando; García, Luis A.; Blanco, Gloria

2018-01-01

A cultivation-dependent approach revealed that highly diverse populations of Streptomyces were present in atmospheric precipitations from a hailstorm event sampled in February 2016 in the Cantabrian Sea coast, North of Spain. A total of 29 bioactive Streptomyces strains isolated from small samples of hailstone and rainwater, collected from this hailstorm event, were studied here. Taxonomic identification by 16S rRNA sequencing revealed more than 20 different Streptomyces species, with their closest homologs displaying mainly oceanic but also terrestrial origins. Backward trajectory analysis revealed that the air-mass sources of the hailstorm event, with North Western winds, were originated in the Arctic Ocean (West Greenland and North Iceland) and Canada (Labrador), depending on the altitude. After traveling across the North Atlantic Ocean during 4 days the air mass reached Europe and precipitated as hailstone and rain water at the sampling place in Spain. The finding of Streptomyces species able to survive and disperse through the atmosphere increases our knowledge of the biogeography of genus Streptomyces on Earth, and reinforces our previous dispersion model, suggesting a generalized feature for the genus which could have been essential in his evolution. This unique atmospheric-derived Streptomyces collection was screened for production of bioactive secondary metabolites. Analyses of isolates ethyl acetate extracts by LC-UV-MS and further database comparison revealed an extraordinary diversity of bioactive natural products. One hundred molecules were identified, mostly displaying contrasted antibiotic and antitumor/cytotoxic activities, but also antiparasitic, antiviral, anti-inflammatory, neuroprotector, and insecticide properties. More interestingly, 38 molecules not identified in natural products databases might represent new natural products. Our results revealed for the first time an extraordinary diversity of Streptomyces species in the atmosphere able to

Global Sourcing Flexibility

DEFF Research Database (Denmark)

Ørberg Jensen, Peter D.; Petersen, Bent

2013-01-01

the higher costs (but decreased risk for value chain disruption) embedded in a more flexible global sourcing model that allows the firm to replicate and/or relocate activities across multiple locations. We develop a model and propositions on facilitating and constraining conditions of global sourcing...... sourcing flexibility. Here we draw on prior research in the fields of organizational flexibility, international business and global sourcing as well as case examples and secondary studies. In the second part of the paper, we discuss the implications of global sourcing flexibility for firm strategy...... and operations against the backdrop of the theory-based definition of the construct. We discuss in particular the importance of global sourcing flexibility for operational performance stability, and the trade-off between specialization benefits, emerging from location and service provider specialization, versus...

Real-Time Localization of Moving Dipole Sources for Tracking Multiple Free-Swimming Weakly Electric Fish

Science.gov (United States)

Jun, James Jaeyoon; Longtin, André; Maler, Leonard

2013-01-01

In order to survive, animals must quickly and accurately locate prey, predators, and conspecifics using the signals they generate. The signal source location can be estimated using multiple detectors and the inverse relationship between the received signal intensity (RSI) and the distance, but difficulty of the source localization increases if there is an additional dependence on the orientation of a signal source. In such cases, the signal source could be approximated as an ideal dipole for simplification. Based on a theoretical model, the RSI can be directly predicted from a known dipole location; but estimating a dipole location from RSIs has no direct analytical solution. Here, we propose an efficient solution to the dipole localization problem by using a lookup table (LUT) to store RSIs predicted by our theoretically derived dipole model at many possible dipole positions and orientations. For a given set of RSIs measured at multiple detectors, our algorithm found a dipole location having the closest matching normalized RSIs from the LUT, and further refined the location at higher resolution. Studying the natural behavior of weakly electric fish (WEF) requires efficiently computing their location and the temporal pattern of their electric signals over extended periods. Our dipole localization method was successfully applied to track single or multiple freely swimming WEF in shallow water in real-time, as each fish could be closely approximated by an ideal current dipole in two dimensions. Our optimized search algorithm found the animal’s positions, orientations, and tail-bending angles quickly and accurately under various conditions, without the need for calibrating individual-specific parameters. Our dipole localization method is directly applicable to studying the role of active sensing during spatial navigation, or social interactions between multiple WEF. Furthermore, our method could be extended to other application areas involving dipole source

Real-Time Localization of Moving Dipole Sources for Tracking Multiple Free-Swimming Weakly Electric Fish.

Directory of Open Access Journals (Sweden)

James Jaeyoon Jun

Full Text Available In order to survive, animals must quickly and accurately locate prey, predators, and conspecifics using the signals they generate. The signal source location can be estimated using multiple detectors and the inverse relationship between the received signal intensity (RSI and the distance, but difficulty of the source localization increases if there is an additional dependence on the orientation of a signal source. In such cases, the signal source could be approximated as an ideal dipole for simplification. Based on a theoretical model, the RSI can be directly predicted from a known dipole location; but estimating a dipole location from RSIs has no direct analytical solution. Here, we propose an efficient solution to the dipole localization problem by using a lookup table (LUT to store RSIs predicted by our theoretically derived dipole model at many possible dipole positions and orientations. For a given set of RSIs measured at multiple detectors, our algorithm found a dipole location having the closest matching normalized RSIs from the LUT, and further refined the location at higher resolution. Studying the natural behavior of weakly electric fish (WEF requires efficiently computing their location and the temporal pattern of their electric signals over extended periods. Our dipole localization method was successfully applied to track single or multiple freely swimming WEF in shallow water in real-time, as each fish could be closely approximated by an ideal current dipole in two dimensions. Our optimized search algorithm found the animal's positions, orientations, and tail-bending angles quickly and accurately under various conditions, without the need for calibrating individual-specific parameters. Our dipole localization method is directly applicable to studying the role of active sensing during spatial navigation, or social interactions between multiple WEF. Furthermore, our method could be extended to other application areas involving dipole

Using web-sources for location based systems on mobile phones

NARCIS (Netherlands)

Pannevis, M.; Marx, M.

2008-01-01

The paper describes the implementation of a context aware location and time based system on a normal mobile phone, with a minimum of requirements (Bluetooth, Internet access, Java ME, and a simple webbrowser). We can answer the following queries based on data crawled from the web and enriched with

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

Science.gov (United States)

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.

Sources of atmospheric acidity

International Nuclear Information System (INIS)

Clarke, A.G.

1992-01-01

The emissions of acid gases from anthropogenic sources and their impact on the environment are the main concern of this book. However, that impact can only be assessed if all the naturally occurring sources of these gases are also known and can be quantified. Given the widely dispersed nature of the natural sources and the problems of measurement of trace species at low concentrations, often in remote regions, the quantification is a very difficult task. Nevertheless, considerable progress has been made over the last decade. In this chapter both man-made and natural sources of atmospheric acidity will be reviewed, but the emphasis will be placed not so much on the global balances as on the scale of the natural sources in relation to the man-made sources. This requires that the very uneven geographical distribution of emissions and the lifetime of individual chemical species be taken into account. The emissions considered are sulphur compounds, nitrogen compounds, chlorine compounds and organic acids. The anthropogenic sources discussed are the combustion of fossil fuels and certain industrial processes. Emissions data for anthropogenic sources are given for the United Kingdom, Europe, USA and globally. A list of 95 references is given. (Author)

The potential use of rainwater as alternative source of drinking water by using laterite soil as natural adsorbent

Science.gov (United States)

Omar, Khairunnisa Fakhriah Mohd; Palaniandy, Puganeshwary; Adlan, Mohd Nordin; Aziz, Hamidi Abdul; Subramaniam, Ambarasi

2017-10-01

Generally, the rainwater has low concentration of pollutants, whereby it is applicable for domestic water supply. Due to the low concentration of pollutants, further treatment such as adsorption is necessary to treat the harvested rainwater as an alternative source of drinking water supply. Therefore, this research has been carried out to determine the quality of rainwater from different types of locations, which are; rural residential area, urban residential area, agricultural area, industrial area, and open surface. The rainwater sampling was carried out from September 2014 to December 2015. The parameters that have been analysed during the sampling process are chemical oxygen demand (COD), turbidity, heavy metals, and Escherichia coli (E.coli). The sampling results show that the rainwater provides low concentration of contaminants. Thus, it has high potential to be used as alternative source of potable and non potable water supply with a suitable treatment. Due to that, an experimental work contained of 86 of designated experiments for a batch study has been carried out to determine the performance of laterite soil as an adsorbent to remove pollutants that present in the rainwater (i.e. zinc, manganese, and E.coli). The operating factors involved in the experimental works are pH, mass of adsorbents, contact time, initial concentration of zinc, manganese, and E.coli. In this study, the experimental data of the batch study was analysed by developing regression model equation and analysis of variance. Perturbation plots were analysed to determine the effectiveness of the operating factors by developing response surface model, resulting that the high removals of zinc, manganese, and E.coli are 95.8%, 94.05% and 100%, respectively. Overall, this research works found out that the rainwater has a good quality as alternative source of drinking water by providing a suitable treatment. The application of laterite soil as natural adsorbent shows that it has potential to be

Efficient Location of Research Reference Sources in the Field of Dance.

Science.gov (United States)

Kissinger, Pat; Jay, Danielle

More than 45 basic dance reference research sources that would be useful to students, scholars, teachers, historians, and therapists are discussed in this bibliographic essay. Aspects of dance covered include choreography, criticism, teaching principles, aesthetic theory, dance therapy, and history. Sources are grouped by type: dictionaries and…

Natural radiation contribution to renewable energy searching

International Nuclear Information System (INIS)

Balcazar, M.; Lopez, A.; Flores, M.; Huerta, M.

2014-08-01

High anomalies of naturally occurring radon in geothermal fields are becoming an additional geophysics tool for determining the areas of geothermal activity underground. Under close collaboration with the Federal Electricity Board in Mexico (CFE), we have study four geothermal fields (Los Azufres, Tres Virgenes, Humeros and Acoculco) for extending the energy potentially. The heat source in hydrothermal systems produces geothermal gasses, which transport radon to the surface faster than the common diffusion process in absence of a geothermal activity. This paper presents: mechanism of radon production, main physical and chemical features that make it an excellent indicator for locating heat sources of geothermal reservoirs, the detection basis of in situ radon concentration using a high sensitive radiation chamber and the planning experimental strategy for successful use of this technique. (author)

Natural radiation contribution to renewable energy searching

Energy Technology Data Exchange (ETDEWEB)

Balcazar, M.; Lopez, A. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Flores, M.; Huerta, M., E-mail: miguel.balcazar@inin.gob.mx [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Alejandro Volta 655, 58290 Morelia, Michoacan (Mexico)

2014-08-15

High anomalies of naturally occurring radon in geothermal fields are becoming an additional geophysics tool for determining the areas of geothermal activity underground. Under close collaboration with the Federal Electricity Board in Mexico (CFE), we have study four geothermal fields (Los Azufres, Tres Virgenes, Humeros and Acoculco) for extending the energy potentially. The heat source in hydrothermal systems produces geothermal gasses, which transport radon to the surface faster than the common diffusion process in absence of a geothermal activity. This paper presents: mechanism of radon production, main physical and chemical features that make it an excellent indicator for locating heat sources of geothermal reservoirs, the detection basis of in situ radon concentration using a high sensitive radiation chamber and the planning experimental strategy for successful use of this technique. (author)

Diversity, abundance, and possible sources of fecal bacteria in the Yangtze River.

Science.gov (United States)

Sun, Haohao; He, Xiwei; Ye, Lin; Zhang, Xu-Xiang; Wu, Bing; Ren, Hongqiang

2017-03-01

The fecal bacteria in natural waters may pose serious risks on human health. Although many source tracking methods have been developed and used to determine the possible sources of the fecal pollution, little is known about the overall diversity and abundance of fecal bacterial community in natural waters. In this study, a method based on fecal bacterial sequence library was introduced to evaluate the fecal bacterial profile in the Yangtze River (Nanjing section). Our results suggested that the Yangtze River water harbors diverse fecal bacteria. Fifty-eight fecal operational taxonomic units (97% identity level) were detected in the Yangtze River water samples and the relative abundance of fecal bacteria in these samples ranged from 0.1 to 8%. It was also found that the relative abundances of the fecal bacteria in locations near to the downstream of wastewater treatment plants were obviously higher than those in other locations. However, the high abundance of fecal bacteria could decrease to the normal level in 2~4 km in the river due to degradation or dilution, and the overall fecal bacteria level changed little when the Yangtze River flew through the Nanjing City. Moreover, the fecal bacteria in the Yangtze River water were found to be highly associated (Spearman rho = 0.804, P Yangtze River and advance our understandings of the fecal bacteria community in the natural waters.

Application of water quality index for the assessment of suitability of natural sources of water for drinking in rural areas of east Sikkim, India

OpenAIRE

Shubra Poonia; T Shantikumar Singh; Dechen C Tsering

2015-01-01

In Sikkim, especially in the rural areas where there is no supply of treated water for drinking and other domestic uses, natural surface water is the only source. The objective was to assess the water quality of natural sources of water in the rural areas of East Sikkim using a water quality index (WQI) for different seasons. A total of 225 samples, that is, 75 in winter, 75 in summer, and 75 in monsoon were collected from different sources for physicochemical analysis, and a WQI was calculat...

Recent advances in microencapsulation of natural sources of antimicrobial compounds used in food - A review.

Science.gov (United States)

Castro-Rosas, Javier; Ferreira-Grosso, Carlos Raimundo; Gómez-Aldapa, Carlos Alberto; Rangel-Vargas, Esmeralda; Rodríguez-Marín, María Luisa; Guzmán-Ortiz, Fabiola Araceli; Falfan-Cortes, Reyna Nallely

2017-12-01

Food safety and microbiological quality are major priorities in the food industry. In recent years, there has been an increasing interest in the use of natural antimicrobials in food products. An ongoing challenge with natural antimicrobials is their degradation during food storage and/or processing, which reduces their antimicrobial activity. This creates the necessity for treatments that maintain their stability and/or activity when applied to food. Microencapsulation of natural antimicrobial compounds is a promising alternative once this technique consists of producing microparticles, which protect the encapsulated active substances. In other words, the material to be protected is embedded inside another material or system known as wall material. There are few reports in the literature about microencapsulation of antimicrobial compounds. These published articles report evidence of increased antimicrobial stability and activity when the antimicrobials are microencapsulated when compared to unprotected ones during storage. This review focuses mainly on natural sources of antimicrobial compounds and the methodological approach for encapsulating these natural compounds. Current data on the microencapsulation of antimicrobial compounds and their incorporation into food suggests that 1) encapsulation increases compound stability during storage and 2) encapsulation of antimicrobial compounds reduces their interaction with food components, preventing their inactivation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Natural radioactivity in groundwater sources in Ireland

Energy Technology Data Exchange (ETDEWEB)

Currivan, L.; Dowdall, A.; Mcginnity, P.; Ciara, M. [Radiological Protection Institute of Ireland (Ireland); Craig, M. [Environmental Protection Agency (Ireland)

2014-07-01

The Radiological Protection Institute of Ireland (RPII) in collaboration with the Irish Environmental Protection Agency (EPA) undertook a national survey of radioactivity in groundwater sources for compliance with parameters set out in the European Communities Drinking Water Directive. The Directive outlines the minimum requirements for the quality of drinking water and water intended for human consumption. Over two hundred samples were screened for radioactivity. Where indicated, analysis for individual radionuclide activity was undertaken and the radiation dose arising calculated. Furthermore, samples were analysed for radon concentration. This survey is the first comprehensive national survey of radioactivity in groundwater sources in Ireland. Approximately 18 per cent of drinking water in Ireland originates from groundwater and springs with the remainder from surface water. Between 2007 and 2011, water samples from a representative network of groundwater sources were analysed and assessed for compliance with the radioactivity parameters set out in the Drinking Water Directive. The assessment was carried out using the methodology for screening drinking water set out by the WHO. For practical purposes the WHO recommended screening levels for drinking water below which no further action is required of 100 mBq/l for gross alpha activity and 1000 mBq/l for gross beta activity were applied. Of the 203 groundwater sources screened for gross alpha and gross beta all met the gross beta activity criteria of less than 1000 mBq/l and 175 supplies had gross alpha activity concentrations of less than 100 mBq/l. For these sources no further analysis was required. The remaining 28 sources required further (radionuclide-specific) analysis from an alpha activity perspective. Results on ranges and distributions of radionuclide concentrations in groundwater as well as ingestion doses estimated for consumers of these water supplies will be presented. Document available in abstract

Turkey's natural gas necessity, consumption and future perspectives

International Nuclear Information System (INIS)

Kilic, A.M.

2006-01-01

Turkey is an important candidate to be the 'energy corridor' in the transmission of the abundant oil and natural gas resources of the Middle East and Middle Asia countries to the Western market. Furthermore, Turkey is planning to increase its oil and gas pipeline infrastructure to accommodate its increased energy consumption. Naturally, Turkish natural gas usage is projected to increase remarkably in coming years, with the prime consumers, expected to be industry and power plants. Energy demand of Turkey is growing by 8% annually, one of the highest rates in the world. In addition, natural gas consumption is the fastest growing primary energy source in Turkey. Gas sales started at 0.5 bcm (billion cubic meters), in 1987 and reached approximately 22 bcm in 2003. This article deals with energy policies and natural gas consumption of Turkey. Besides modernization of present lines and realization of capacity increase, new lines will also be needed. In this context, Turkey, due to its geographical location is, in an important position to vary European supply. Therefore, Turkey's role as a transitory area gains importance

Locating and limiting radon in dwellings

International Nuclear Information System (INIS)

Hildingson, O.; Gustafsson, J.; Nilsson, I.

1984-01-01

More than 3,300 Swedish dwellings have an indoor radon daughter concentration above 400 Bq.m -3 (or 0.108 WL). It is considered to be unsafe to live in any of these dwellings and the radon daughter concentration has to be reduced. Before deciding what measures to take, it is important to determine the radon sources. Possible sources are exhalation from building materials and/or radon transport from the ground into the building through cracks and joints in the slab. Different methods of locating the sources have been developed. To locate cracks and joints in slabs the ventilation rate and the air pressure difference relative to the ground are changed while monitoring radon/radon daughter concentration. The effect of five different measures to reduce the indoor radon daughter concentration have also been evaluated: increased ventilation rate by mechanical ventilation, ventilation of the small spaces between the floor and the slab, sealing the surface of radon exhaling walls, sealing joints and cracks in the slab, and ventilation of the drainage under the slab. (author)

Improvement Schemes for Indoor Mobile Location Estimation: A Survey

Directory of Open Access Journals (Sweden)

Jianga Shang

2015-01-01

Full Text Available Location estimation is significant in mobile and ubiquitous computing systems. The complexity and smaller scale of the indoor environment impose a great impact on location estimation. The key of location estimation lies in the representation and fusion of uncertain information from multiple sources. The improvement of location estimation is a complicated and comprehensive issue. A lot of research has been done to address this issue. However, existing research typically focuses on certain aspects of the problem and specific methods. This paper reviews mainstream schemes on improving indoor location estimation from multiple levels and perspectives by combining existing works and our own working experiences. Initially, we analyze the error sources of common indoor localization techniques and provide a multilayered conceptual framework of improvement schemes for location estimation. This is followed by a discussion of probabilistic methods for location estimation, including Bayes filters, Kalman filters, extended Kalman filters, sigma-point Kalman filters, particle filters, and hidden Markov models. Then, we investigate the hybrid localization methods, including multimodal fingerprinting, triangulation fusing multiple measurements, combination of wireless positioning with pedestrian dead reckoning (PDR, and cooperative localization. Next, we focus on the location determination approaches that fuse spatial contexts, namely, map matching, landmark fusion, and spatial model-aided methods. Finally, we present the directions for future research.

Natural and near natural tropical forest values

Science.gov (United States)

Daniel H. Henning

2011-01-01

This paper identifies and describes some of the values associated with tropical rain forests in their natural and near-natural conditions. Tropical rain forests are moist forests in the humid tropics where temperature and rainfall are high and the dry season is short. These closed (non-logged) and broad-leaved forests are a global resource. Located almost entirely in...

Natural convection heat transfer in a rectangular pool with volumetric heat sources

International Nuclear Information System (INIS)

Lee, Seung Dong; Lee, Kang Hee; Suh, Kune Y.

2003-01-01

Natural convection plays an important role in determining the thermal load from debris accumulated in the reactor vessel lower head during a severe accident. The heat transfer within the molten core material can be characterized by buoyancy-induced flows resulting from internal heating due to decay of fission products. The thermo-fluid dynamic characteristics of the molten pool depend strongly on the thermal boundary conditions. The spatial and temporal variation of heat flux on the pool wall boundaries and the pool superheat are mainly characterized by the natural convection flow inside the molten pool. In general, natural convection involving internal heat generation is delineated in terms of the modified Rayleigh number, Ra', which quantifies the internal heat source and hence the strength of buoyancy. The test section is of rectangular cavity whose length, width, and height are 500 mm, 80 mm, and 250 mm, respectively. A total of twenty-four T-type thermocouples were installed in the test loop to measure temperature distribution. Four T-type thermocouples were utilized to measure temperatures on the boundary. A direct heating method was adopted in this test to simulate the uniform heat generation. The experiments covered a range of Rayleigh number, Ra, between 4.87x10 7 and 2.32x10 14 and Prandtl number, Pr, between 0.7 and 3.98. Tests were conducted with water and air as simulant. The upper and lower boundary conditions were maintained at a uniform temperature of 10degC. (author)

Optimal hub location in pipeline networks

Energy Technology Data Exchange (ETDEWEB)

Dott, D.R.; Wirasinghe, S.C.; Chakma, A. [Univ. of Calgary, Alberta (Canada)

1996-12-31

This paper discusses optimization strategies and techniques for the location of natural gas marketing hubs in the North American gas pipeline network. A hub is a facility at which inbound and outbound network links meet and freight is redirected towards their destinations. Common examples of hubs used in the gas pipeline industry include gas plants, interconnects and market centers. Characteristics of the gas pipeline industry which are relevant to the optimization of transportation costs using hubs are presented. Allocation techniques for solving location-allocation problems are discussed. An outline of the research in process by the authors in the field of optimal gas hub location concludes the paper.

Radiological impact of natural and artificial sources of ionizing radiation. Report UNSCEAR 2000

International Nuclear Information System (INIS)

Cancio, D.

2001-01-01

The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was established by the General Assembly in 1995. It has the mandate to assess the levels and effects of ionizing radiation. During the last years UNSCEAR has undertaken a broad review of the natural and artificial sources of ionizing radiation. The results of these evaluations have been presented in a Report to the General Assembly with Scientific Annexes including extensive data for the world community (Report UNSCEAR 2000). The greatest contribution to radiation exposure comes from natural background sources. There are considerable variation in the exposures of the population depending on the altitude and latitude, characteristics of the soil and diet and the construction and ventilation features of houses. The global annual average per caput is 2.4 mSv with typical range 1 to 10 mSv. The next largest component comes from medical radiation examinations and treatments with an annual average of 0.4 mSv ranging from 0.04 to 1.0 mSv depending on the level o f medical care. The man-made practices, activities, and events in which radionuclides are released to the environment are always of much concern, but usually they contribute quite low to radiation exposure to humans. Atmospheric testing caused the greatest releases but nowadays very low residual annual levels of exposures persist (0.005 mSv). Nuclear Power production is responsible for only very low exposure and may reach in the future an average annual level of 0.0002 mSv. (Author)

The Use of LiDAR Elevation Data and Satellite Imagery to Locate Critical Source Areas to Diffuse Pollution in Agricultural Watersheds

Science.gov (United States)

Drouin, Ariane; Michaud, Aubert; Thériault, Georges; Beaudin, Isabelle; Rodrigue, Jean-François; Denault, Jean-Thomas; Desjardins, Jacques; Côté, Noémi

2013-04-01

In Quebec / Canada, water quality improvement in rural areas greatly depends on the reduction of diffuse pollution. Indeed, point source pollution has been reduced significantly in Canada in recent years by creating circumscribed pits for manure and removing animals from stream. Diffuse pollution differs from point source pollution because it is spread over large areas. In agricultural areas, sediment loss by soil and riverbank erosion along with loss of nutrients (phosphorus, nitrogen, etc.) and pesticides from fields represent the main source of non-point source pollution. The factor mainly responsible for diffuse pollution in agricultural areas is surface runoff occurring in poorly drained areas in fields. The presence of these poorly drained areas is also one of the most limiting factors in crop productivity. Thus, a reconciliation of objectives at the farm (financial concern for farmers) and off-farm concerns (environmental concern) is possible. In short, drainage, runoff, erosion, water quality and crop production are all interconnected issues that need to be tackled together. Two complementary data sources are mainly used in the diagnosis of drainage, surface runoff and erosion : elevation data and multispectral satellite images. In this study of two watersheds located in Québec (Canada), LiDAR elevation data and satellite imagery (QuickBird, Spot and Landsat) were acquired. The studied territories have been partitioned in hydrologic response units (HRUs) according to sub-basins, soils, elevation (topographic index) and land use. These HRUs are afterwards used in a P index software (P-Edit) that calculates the quantities of sediments and phosphorus exported from each HRUs. These exports of sediments and phosphorus are validated with hydrometric and water quality data obtain in two sub-basins and are also compared to soil brightness index derived from multispectral images. This index is sensitive to soil moisture and thus highlights areas where the soil is

An application of time-frequency signal analysis technique to estimate the location of an impact source on a plate type structure

International Nuclear Information System (INIS)

Park, Jin Ho; Lee, Jeong Han; Choi, Young Chul; Kim, Chan Joong; Seong, Poong Hyun

2005-01-01

It has been reviewed whether it would be suitable that the application of the time-frequency signal analysis techniques to estimate the location of the impact source in plate structure. The STFT(Short Time Fourier Transform), WVD(Wigner-Ville distribution) and CWT(Continuous Wavelet Transform) methods are introduced and the advantages and disadvantages of those methods are described by using a simulated signal component. The essential of the above proposed techniques is to separate the traveling waves in both time and frequency domains using the dispersion characteristics of the structural waves. These time-frequency methods are expected to be more useful than the conventional time domain analyses for the impact localization problem on a plate type structure. Also it has been concluded that the smoothed WVD can give more reliable means than the other methodologies for the location estimation in a noisy environment

Mental Health and Drivers of Need in Emergent and Non-Emergent Emergency Department (ED) Use: Do Living Location and Non-Emergent Care Sources Matter?

Science.gov (United States)

McManus, Moira C; Cramer, Robert J; Boshier, Maureen; Akpinar-Elci, Muge; Van Lunen, Bonnie

2018-01-13

Emergency department (ED) utilization has increased due to factors such as admissions for mental health conditions, including suicide and self-harm. We investigate direct and moderating influences on non-emergent ED utilization through the Behavioral Model of Health Services Use. Through logistic regression, we examined correlates of ED use via 2014 New York State Department of Health Statewide Planning and Research Cooperative System outpatient data. Consistent with the primary hypothesis, mental health admissions were associated with emergent use across models, with only a slight decrease in effect size in rural living locations. Concerning moderating effects, Spanish/Hispanic origin was associated with increased likelihood for emergent ED use in the rural living location model, and non-emergent ED use for the no non-emergent source model. 'Other' ethnic origin increased the likelihood of emergent ED use for rural living location and no non-emergent source models. The findings reveal 'need', including mental health admissions, as the largest driver for ED use. This may be due to mental healthcare access, or patients with mental health emergencies being transported via first responders to the ED, as in the case of suicide, self-harm, manic episodes or psychotic episodes. Further educating ED staff on this patient population through gatekeeper training may ensure patients receive the best treatment and aid in driving access to mental healthcare delivery changes.

Natural Products from Mangrove Actinomycetes

Directory of Open Access Journals (Sweden)

Dong-Bo Xu

2014-05-01

Full Text Available Mangroves are woody plants located in tropical and subtropical intertidal coastal regions. The mangrove ecosystem is becoming a hot spot for natural product discovery and bioactivity survey. Diverse mangrove actinomycetes as promising and productive sources are worth being explored and uncovered. At the time of writing, we report 73 novel compounds and 49 known compounds isolated from mangrove actinomycetes including alkaloids, benzene derivatives, cyclopentenone derivatives, dilactones, macrolides, 2-pyranones and sesquiterpenes. Attractive structures such as salinosporamides, xiamycins and novel indolocarbazoles are highlighted. Many exciting compounds have been proven as potential new antibiotics, antitumor and antiviral agents, anti-fibrotic agents and antioxidants. Furthermore, some of their biosynthetic pathways have also been revealed. This review is an attempt to consolidate and summarize the past and the latest studies on mangrove actinomycetes natural product discovery and to draw attention to their immense potential as novel and bioactive compounds for marine drugs discovery.

Jump locations of jump-diffusion processes with state-dependent rates

International Nuclear Information System (INIS)

Miles, Christopher E; Keener, James P

2017-01-01

We propose a general framework for studying statistics of jump-diffusion systems driven by both Brownian noise (diffusion) and a jump process with state-dependent intensity. Of particular natural interest in many physical systems are the jump locations: the system evaluated at the jump times. As an example, this could be the voltage at which a neuron fires, or the so-called ‘threshold voltage’. However, the state-dependence of the jump rate provides direct coupling between the diffusion and jump components, making it difficult to disentangle the two to study individually. In this work, we provide an iterative map formulation of the sequence of distributions of jump locations. The distributions computed by this map can be used to elucidate other interesting quantities about the process, including statistics of the interjump times. Ultimately, the limit of the map reveals that knowledge of the stationary distribution of the full process is sufficient to recover (but not necessarily equal to) the distribution of jump locations. We propose two biophysical examples to illustrate the use of this framework to provide insight about a system. We find that a sharp threshold voltage emerges robustly in a simple stochastic integrate-and-fire neuronal model. The interplay between the two sources of noise is also investigated in a stepping model of molecular motor in intracellular transport pulling a diffusive cargo. (paper)

An RSS based location estimation technique for cognitive relay networks

KAUST Repository

Qaraqe, Khalid A.

2010-11-01

In this paper, a received signal strength (RSS) based location estimation method is proposed for a cooperative wireless relay network where the relay is a cognitive radio. We propose a method for the considered cognitive relay network to determine the location of the source using the direct and the relayed signal at the destination. We derive the Cramer-Rao lower bound (CRLB) expressions separately for x and y coordinates of the location estimate. We analyze the effects of cognitive behaviour of the relay on the performance of the proposed method. We also discuss and quantify the reliability of the location estimate using the proposed technique if the source is not stationary. The overall performance of the proposed method is presented through simulations. ©2010 IEEE.

Location, location, location: Extracting location value from house prices

OpenAIRE

Kolbe, Jens; Schulz, Rainer; Wersing, Martin; Werwatz, Axel

2012-01-01

The price for a single-family house depends both on the characteristics of the building and on its location. We propose a novel semiparametric method to extract location values from house prices. After splitting house prices into building and land components, location values are estimated with adaptive weight smoothing. The adaptive estimator requires neither strong smoothness assumptions nor local symmetry. We apply the method to house transactions from Berlin, Germany. The estimated surface...

Locating sources within a dense sensor array using graph clustering

Science.gov (United States)

Gerstoft, P.; Riahi, N.

2017-12-01

We develop a model-free technique to identify weak sources within dense sensor arrays using graph clustering. No knowledge about the propagation medium is needed except that signal strengths decay to insignificant levels within a scale that is shorter than the aperture. We then reinterpret the spatial coherence matrix of a wave field as a matrix whose support is a connectivity matrix of a graph with sensors as vertices. In a dense network, well-separated sources induce clusters in this graph. The geographic spread of these clusters can serve to localize the sources. The support of the covariance matrix is estimated from limited-time data using a hypothesis test with a robust phase-only coherence test statistic combined with a physical distance criterion. The latter criterion ensures graph sparsity and thus prevents clusters from forming by chance. We verify the approach and quantify its reliability on a simulated dataset. The method is then applied to data from a dense 5200 element geophone array that blanketed of the city of Long Beach (CA). The analysis exposes a helicopter traversing the array and oil production facilities.

MICROBIOLOGICAL STUDIES RECQUIRED FOR A SCIENTIFIC MANAGEMENT OF THE NATURAL MINERAL WATER SOURCES

Directory of Open Access Journals (Sweden)

IONESCU ANA DESPINA

2007-01-01

Full Text Available This paper presents some of the results obtained concerning the discovery,characterization, screening and management of some still unknown or not yet fullycharacterized natural sources of mineral waters, in order to render themeconomically profitable and to contribute to the public health development.Following some empiric, local observations upon the qualities they have in thetreatment of different maladies, a set of physical, hydrological, chemical andmicrobiological analyses was established, in order to substantiate scientifically theirtherapeutic potential. Moreover, the authors have selected some areas situated inthe neighborhood of the old (some of them already closed salt mines.

Landscape consequences of natural gas extraction in Armstrong and Indiana Counties, Pennsylvania, 2004–2010

Science.gov (United States)

Slonecker, Terry E.; Milheim, Lesley E.; Roig-Silva, Coral M.; Malizia, Alexander R.

2013-01-01

Increased demands for cleaner burning energy, coupled with the relatively recent technological advances in accessing unconventional hydrocarbon-rich geologic formations, have led to an intense effort to find and extract natural gas from various underground sources around the country. One of these sources, the Marcellus Shale, located in the Allegheny Plateau, is currently undergoing extensive drilling and production. The technology used to extract gas in the Marcellus Shale is known as hydraulic fracturing and has garnered much attention because of its use of large amounts of fresh water, its use of proprietary fluids for the hydraulic-fracturing process, its potential to release contaminants into the environment, and its potential effect on water resources. Nonetheless, development of natural gas extraction wells in the Marcellus Shale is only part of the overall natural gas story in this area of Pennsylvania. Conventional natural gas wells are commonly located in the same general area as the Marcellus Shale and are frequently developed in clusters across the landscape. The combined effects of these two natural gas extraction methods create potentially serious patterns of disturbance on the landscape. This document quantifies the landscape changes and consequences of natural gas extraction for Armstrong County and Indiana County in Pennsylvania between 2004 and 2010. Patterns of landscape disturbance related to natural gas extraction activities were collected and digitized using National Agriculture Imagery Program (NAIP) imagery for 2004, 2005/2006, 2008, and 2010. The disturbance patterns were then used to measure changes in land cover and land use using the National Land Cover Database (NLCD) of 2001. A series of landscape metrics is also used to quantify these changes and is included in this publication.

[A mobile sensor for remote detection of natural gas leakage].

Science.gov (United States)

Zhang, Shuai; Liu, Wen-qing; Zhang, Yu-jun; Kan, Rui-feng; Ruan, Jun; Wang, Li-ming; Yu, Dian-qiang; Dong, Jin-ting; Han, Xiao-lei; Cui, Yi-ben; Liu, Jian-guo

2012-02-01

The detection of natural gas pipeline leak becomes a significant issue for body security, environmental protection and security of state property. However, the leak detection is difficult, because of the pipeline's covering many areas, operating conditions and complicated environment. A mobile sensor for remote detection of natural gas leakage based on scanning wavelength differential absorption spectroscopy (SWDAS) is introduced. The improved soft threshold wavelet denoising was proposed by analyzing the characteristics of reflection spectrum. And the results showed that the signal to noise ratio (SNR) was increased three times. When light intensity is 530 nA, the minimum remote sensitivity will be 80 ppm x m. A widely used SWDAS can make quantitative remote sensing of natural gas leak and locate the leak source precisely in a faster, safer and more intelligent way.

Evidence Integration in Natural Acoustic Textures during Active and Passive Listening.

Science.gov (United States)

Górska, Urszula; Rupp, Andre; Boubenec, Yves; Celikel, Tansu; Englitz, Bernhard

2018-01-01

Many natural sounds can be well described on a statistical level, for example, wind, rain, or applause. Even though the spectro-temporal profile of these acoustic textures is highly dynamic, changes in their statistics are indicative of relevant changes in the environment. Here, we investigated the neural representation of change detection in natural textures in humans, and specifically addressed whether active task engagement is required for the neural representation of this change in statistics. Subjects listened to natural textures whose spectro-temporal statistics were modified at variable times by a variable amount. Subjects were instructed to either report the detection of changes (active) or to passively listen to the stimuli. A subset of passive subjects had performed the active task before (passive-aware vs passive-naive). Psychophysically, longer exposure to pre-change statistics was correlated with faster reaction times and better discrimination performance. EEG recordings revealed that the build-up rate and size of parieto-occipital (PO) potentials reflected change size and change time. Reduced effects were observed in the passive conditions. While P2 responses were comparable across conditions, slope and height of PO potentials scaled with task involvement. Neural source localization identified a parietal source as the main contributor of change-specific potentials, in addition to more limited contributions from auditory and frontal sources. In summary, the detection of statistical changes in natural acoustic textures is predominantly reflected in parietal locations both on the skull and source level. The scaling in magnitude across different levels of task involvement suggests a context-dependent degree of evidence integration.

Antioxidants: Characterization, natural sources, extraction and analysis

OpenAIRE

OROIAN, MIRCEA; Escriche Roberto, Mª Isabel

2015-01-01

[EN] Recently many review papers regarding antioxidants fromdifferent sources and different extraction and quantification procedures have been published. However none of them has all the information regarding antioxidants (chemistry, sources, extraction and quantification). This article tries to take a different perspective on antioxidants for the new researcher involved in this field. Antioxidants from fruit, vegetables and beverages play an important role in human health, fo...

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

Science.gov (United States)

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...

Landscape consequences of natural gas extraction in Bradford and Washington Counties, Pennsylvania, 2004-2010

Science.gov (United States)

Slonecker, E.T.; Milheim, L.E.; Roig-Silva, C.M.; Malizia, A.R.; Marr, D.A.; Fisher, G.B.

2012-01-01

Increased demands for cleaner burning energy, coupled with the relatively recent technological advances in accessing unconventional hydrocarbon-rich geologic formations, led to an intense effort to find and extract natural gas from various underground sources around the country. One of these sources, the Marcellus Shale, located in the Allegheny Plateau, is undergoing extensive drilling and production. The technology used to extract gas in the Marcellus Shale is known as hydraulic fracturing and has garnered much attention because of its use of large amounts of fresh water, its use of proprietary fluids for the hydraulic-fracturing process, its potential to release contaminants into the environment, and its potential effect on water resources. Nonetheless, development of natural gas extraction wells in the Marcellus Shale is only part of the overall natural gas story in the area of Pennsylvania. Coalbed methane, which is sometimes extracted using the same technique, is often located in the same general area as the Marcellus Shale and is frequently developed in clusters across the landscape. The combined effects of these two natural gas extraction methods create potentially serious patterns of disturbance on the landscape. This document quantifies the landscape changes and consequences of natural gas extraction for Bradford County and Washington County, Pennsylvania, between 2004 and 2010. Patterns of landscape disturbance related to natural gas extraction activities were collected and digitized using National Agriculture Imagery Program (NAIP) imagery for 2004, 2005/2006, 2008, and 2010. The disturbance patterns were then used to measure changes in land cover and land use using the National Land Cover Database (NLCD) of 2001. A series of landscape metrics is used to quantify these changes and are included in this publication.

Natural plant sugar sources of Anopheles mosquitoes strongly impact malaria transmission potential.

Directory of Open Access Journals (Sweden)

Weidong Gu

Full Text Available An improved knowledge of mosquito life history could strengthen malaria vector control efforts that primarily focus on killing mosquitoes indoors using insecticide treated nets and indoor residual spraying. Natural sugar sources, usually floral nectars of plants, are a primary energy resource for adult mosquitoes but their role in regulating the dynamics of mosquito populations is unclear. To determine how the sugar availability impacts Anopheles sergentii populations, mark-release-recapture studies were conducted in two oases in Israel with either absence or presence of the local primary sugar source, flowering Acacia raddiana trees. Compared with population estimates from the sugar-rich oasis, An. sergentii in the sugar-poor oasis showed smaller population size (37,494 vs. 85,595, lower survival rates (0.72 vs. 0.93, and prolonged gonotrophic cycles (3.33 vs. 2.36 days. The estimated number of females older than the extrinsic incubation period of malaria (10 days in the sugar rich site was 4 times greater than in the sugar poor site. Sugar feeding detected in mosquito guts in the sugar-rich site was significantly higher (73% than in the sugar-poor site (48%. In contrast, plant tissue feeding (poor quality sugar source in the sugar-rich habitat was much less (0.3% than in the sugar-poor site (30%. More important, the estimated vectorial capacity, a standard measure of malaria transmission potential, was more than 250-fold higher in the sugar-rich oasis than that in the sugar-poor site. Our results convincingly show that the availability of sugar sources in the local environment is a major determinant regulating the dynamics of mosquito populations and their vector potential, suggesting that control interventions targeting sugar-feeding mosquitoes pose a promising tactic for combating transmission of malaria parasites and other pathogens.

Economics of natural gas upgrading

International Nuclear Information System (INIS)

Hackworth, J.H.; Koch, R.W.

1995-01-01

Natural gas could be an important alternative energy source in meeting some of the market demand presently met by liquid products from crude oil. This study was initiated to analyze three energy markets to determine if greater use could be made of natural gas or natural gas derived products and if those products could be provided on an economically competitive basis. The three markets targeted for possible increases in gas use were motor fuels, power generation, and the chemical feedstocks market. The economics of processes to convert natural gas to transportation fuels, chemical products, and power were analyzed. The economic analysis was accomplished by drawing on a variety of detailed economic studies, updating them and bringing the results to a common basis. The processes analyzed included production of methanol, MTBE, higher alcohols, gasoline, CNG, and LNG for the transportation market. Production and use of methanol and ammonia in the chemical feedstock market and use of natural gas for power generation were also assessed. Use of both high and low quality gas as a process feed stream was evaluated. The analysis also explored the impact of various gas price growth rates and process facility locations, including remote gas areas. In assessing the transportation fuels market the analysis examined production and use of both conventional and new alternative motor fuels

Solar, wind and waves: Natural limits to renewable sources of energy within the Earth system

Energy Technology Data Exchange (ETDEWEB)

Kleidon, Axel [Max-Planck-Institute for Biogeochemistry, Jena (Germany)

2013-07-01

Renewable sources of energy, such as solar, wind, wave, or hydropower, utilize energy that is continuously generated by natural processes within the Earth system from the planetary forcing. Here we estimate the limits of these natural energy conversions and the extent to which these can be used as renewable energy sources using the laws of thermodynamics. At most, wind power in the order of 1 000 TW (1 TW = 1E12 W) can be derived from the total flux of incoming solar radiation of 175 000 TW, which is consistent with estimates based on observations. Other generation rates that are derived from the kinetic energy of wind are in the order of 10-100 TW. In comparison, the human primary energy demand of about 17 TW constitutes a considerable fraction of these rates. We provide some further analysis on the limits of wind power using a combination of conceptual models, observational data, and numerical simulation models. We find that many current estimates of wind power substantially overestimate the potential of wind power because the effect of kinetic energy extraction on the air flow is neglected. We conclude that the only form of renewable energy that is available in substantial amounts and that is associated with minor climatic impacts is solar power.

Health and safety impacts from discrete sources of naturally-occurring and accelerator-produced radioactive materials (NARM)

International Nuclear Information System (INIS)

Nussbaumer, D.; Wiblin, C.; Welch, L.

1993-02-01

This report characterizes discrete sources of naturally-occurring and accelerator-produced radioactive material (NARM) and estimates risks posed by the possession, use and disposal of them. A distinction between discrete and diffuse NARM sources is made with discrete sources being high activity, low volume and diffuse sources being low activity, high volume. Two nanocuries per gram is used as a separation guide between high and low activity, although use of this value does not impact the report's conclusions. Most NARM is under regulatory control of States that either license or register users but reporting requirements are not uniform. Use in consumer products has declined with virtually no production today; however, lack of information available concerning radiation exposures resulting form possession of ageing radium sources precludes a quantitative risk assessment in this report. The report identifies the type of information needed to permit such an assessment. Regarding accelerator-produced radioactive material (ARM), use of this material in nuclear medicine programs has recently increased. Available radiation exposure data regarding ARM handling and use indicates that the risk to workers and the public is low at this time

Comparison of source moment tensor recovered by diffraction stacking migration and source time reversal imaging

Science.gov (United States)

Zhang, Q.; Zhang, W.

2017-12-01

Diffraction stacking migration is an automatic location methods and widely used in microseismic monitoring of the hydraulic fracturing. It utilizes the stacking of thousands waveform to enhance signal-to-noise ratio of weak events. For surface monitoring, the diffraction stacking method is suffered from polarity reverse among receivers due to radiation pattern of moment source. Joint determination of location and source mechanism has been proposed to overcome the polarity problem but needs significantly increased computational calculations. As an effective method to recover source moment tensor, time reversal imaging based on wave equation can locate microseismic event by using interferometry on the image to extract source position. However, the time reversal imaging is very time consuming compared to the diffraction stacking location because of wave-equation simulation.In this study, we compare the image from diffraction stacking and time reversal imaging to check if the diffraction stacking can obtain similar moment tensor as time reversal imaging. We found that image produced by taking the largest imaging value at each point along time axis does not exhibit the radiation pattern, while with the same level of calculation efficiency, the image produced for each trial origin time can generate radiation pattern similar to time reversal imaging procedure. Thus it is potential to locate the source position by the diffraction stacking method for general moment tensor sources.

Landscape consequences of natural gas extraction in Beaver and Butler Counties, Pennsylvania, 2004-2010

Science.gov (United States)

Roig-Silva, Coral M.; Slonecker, E. Terry; Milheim, Lesley E.; Malizia, Alexander R.

2013-01-01

Increased demands for cleaner burning energy, coupled with the relatively recent technological advances in accessing unconventional hydrocarbon-rich geologic formations, have led to an intense effort to find and extract natural gas from various underground sources around the country. One of these sources, the Marcellus Shale, located in the Allegheny Plateau, is currently undergoing extensive drilling and production. The technology used to extract gas in the Marcellus Shale is known as hydraulic fracturing and has garnered much attention because of its use of large amounts of fresh water, its use of proprietary fluids for the hydraulic-fracturing process, its potential to release contaminants into the environment, and its potential effect on water resources. Nonetheless, development of natural gas extraction wells in the Marcellus Shale is only part of the overall natural gas story in this area of Pennsylvania. Conventional natural gas wells, which sometimes use the same technique, are commonly located in the same general area as the Marcellus Shale and are frequently developed in clusters across the landscape. The combined effects of these two natural gas extraction methods create potentially serious patterns of disturbance on the landscape. This document quantifies the landscape changes and consequences of natural gas extraction for Beaver County and Butler County in Pennsylvania between 2004 and 2010. Patterns of landscape disturbance related to natural gas extraction activities were collected and digitized using National Agriculture Imagery Program (NAIP) imagery for 2004, 2005/2006, 2008, and 2010. The disturbance patterns were then used to measure changes in land cover and land use using the National Land Cover Database (NLCD) of 2001. A series of landscape metrics is also used to quantify these changes and is included in this publication.

Landscape consequences of natural gas extraction in Lackawanna and Wayne Counties, Pennsylvania, 2004-2010

Science.gov (United States)

Milheim, L.E.; Slonecker, E.T.; Roig-Silva, C.M.; Malizia, A.R.

2013-01-01

Increased demands for cleaner burning energy, coupled with the relatively recent technological advances in accessing unconventional hydrocarbon-rich geologic formations, have led to an intense effort to find and extract natural gas from various underground sources around the country. One of these sources, the Marcellus Shale, located in the Allegheny Plateau, is currently undergoing extensive drilling and production. The technology used to extract gas in the Marcellus Shale is known as hydraulic fracturing and has garnered much attention because of its use of large amounts of fresh water, its use of proprietary fluids for the hydraulic-fracturing process, its potential to release contaminants into the environment, and its potential effect on water resources. Nonetheless, development of natural gas extraction wells in the Marcellus Shale is only part of the overall natural gas story in this area of Pennsylvania. Conventional natural gas wells, which sometimes use the same technique, are commonly located in the same general area as the Marcellus Shale and are frequently developed in clusters across the landscape. The combined effects of these two natural gas extraction methods create potentially serious patterns of disturbance on the landscape. This document quantifies the landscape changes and consequences of natural gas extraction for Lackawanna County and Wayne County in Pennsylvania between 2004 and 2010. Patterns of landscape disturbance related to natural gas extraction activities were collected and digitized using National Agriculture Imagery Program (NAIP) imagery for 2004, 2005/2006, 2008, and 2010. The disturbance patterns were then used to measure changes in land cover and land use using the National Land Cover Database (NLCD) of 2001. A series of landscape metrics is also used to quantify these changes and is included in this publication.

Landscape consequences of natural gas extraction in Somerset and Westmoreland Counties, Pennsylvania,2004--2010

Science.gov (United States)

Milheim, L.E.; Slonecker, E.T.; Roig-Silva, C.M.; Malizia, A.R.

2013-01-01

Increased demands for cleaner burning energy, coupled with the relatively recent technological advances in accessing unconventional hydrocarbon-rich geologic formations, have led to an intense effort to find and extract natural gas from various underground sources around the country. One of these sources, the Marcellus Shale, located in the Allegheny Plateau, is currently undergoing extensive drilling and production. The technology used to extract gas in the Marcellus Shale is known as hydraulic fracturing and has garnered much attention because of its use of large amounts of fresh water, its use of proprietary fluids for the hydraulic-fracturing process, its potential to release contaminants into the environment, and its potential effect on water resources. Nonetheless, development of natural gas extraction wells in the Marcellus Shale is only part of the overall natural gas story in this area of Pennsylvania. Conventional natural gas wells, which sometimes use the same technique, are commonly located in the same general area as the Marcellus Shale and are frequently developed in clusters across the landscape. The combined effects of these two natural gas extraction methods create potentially serious patterns of disturbance on the landscape. This document quantifies the landscape changes and consequences of natural gas extraction for Somerset County and Westmoreland County in Pennsylvania between 2004 and 2010. Patterns of landscape disturbance related to natural gas extraction activities were collected and digitized using National Agriculture Imagery Program (NAIP) imagery for 2004, 2005/2006, 2008, and 2010. The disturbance patterns were then used to measure changes in land cover and land use using the National Land Cover Database (NLCD) of 2001. A series of landscape metrics is also used to quantify these changes and is included in this publication.

Occurrence and sources of natural and anthropogenic lipid tracers in surface soils from arid urban areas of Saudi Arabia.

Science.gov (United States)

Rushdi, Ahmed I; Al-Mutlaq, Khalid F; El-Mubarak, Aarif H; Al-Saleh, Mohammed A; El-Otaibi, Mubarak T; Ibrahim, Sami M M; Simoneit, Bernd R T

2016-01-01

Soil particles contain a variety of natural and anthropogenic organic components, and in urban areas can be considered as local collectors of pollutants. Surface soil samples were taken from ten urban areas in Riyadh during early winter of 2007. They were extracted with dichloromethane-methanol mixture and the extracts were analyzed by gas chromatography-mass spectrometry. The major compounds were unresolved complex mixture (UCM), plasticizers, n-alkanes, carbohydrates, n-alkanoic acids, hopanes, n-alkanols, and sterols. Vegetation detritus was the major natural source of organic compounds (24.0 ± 15.7%) in samples from areas with less human activities and included n-alkanes, n-alkanoic acids, n-alkanols, sterols and carbohydrates. Vehicular emission products and discarded plastics were the major anthropogenic sources in the soil particles (53.3 ± 21.3% and 22.7 ± 10.7%, respectively). The anthropogenic tracers were UCM, plasticizers, n-alkanes, hopanes and traces of steranes. Vegetation and human activities control the occurrence and distribution of natural and anthropogenic extractable organic matter in this arid urban area. Copyright © 2015 Elsevier Ltd. All rights reserved.

Semantic Location Extraction from Crowdsourced Data

Science.gov (United States)

Koswatte, S.; Mcdougall, K.; Liu, X.

2016-06-01

Crowdsourced Data (CSD) has recently received increased attention in many application areas including disaster management. Convenience of production and use, data currency and abundancy are some of the key reasons for attracting this high interest. Conversely, quality issues like incompleteness, credibility and relevancy prevent the direct use of such data in important applications like disaster management. Moreover, location information availability of CSD is problematic as it remains very low in many crowd sourced platforms such as Twitter. Also, this recorded location is mostly related to the mobile device or user location and often does not represent the event location. In CSD, event location is discussed descriptively in the comments in addition to the recorded location (which is generated by means of mobile device's GPS or mobile communication network). This study attempts to semantically extract the CSD location information with the help of an ontological Gazetteer and other available resources. 2011 Queensland flood tweets and Ushahidi Crowd Map data were semantically analysed to extract the location information with the support of Queensland Gazetteer which is converted to an ontological gazetteer and a global gazetteer. Some preliminary results show that the use of ontologies and semantics can improve the accuracy of place name identification of CSD and the process of location information extraction.

SEMANTIC LOCATION EXTRACTION FROM CROWDSOURCED DATA

Directory of Open Access Journals (Sweden)

S. Koswatte

2016-06-01

Full Text Available Crowdsourced Data (CSD has recently received increased attention in many application areas including disaster management. Convenience of production and use, data currency and abundancy are some of the key reasons for attracting this high interest. Conversely, quality issues like incompleteness, credibility and relevancy prevent the direct use of such data in important applications like disaster management. Moreover, location information availability of CSD is problematic as it remains very low in many crowd sourced platforms such as Twitter. Also, this recorded location is mostly related to the mobile device or user location and often does not represent the event location. In CSD, event location is discussed descriptively in the comments in addition to the recorded location (which is generated by means of mobile device's GPS or mobile communication network. This study attempts to semantically extract the CSD location information with the help of an ontological Gazetteer and other available resources. 2011 Queensland flood tweets and Ushahidi Crowd Map data were semantically analysed to extract the location information with the support of Queensland Gazetteer which is converted to an ontological gazetteer and a global gazetteer. Some preliminary results show that the use of ontologies and semantics can improve the accuracy of place name identification of CSD and the process of location information extraction.

Binary PVA bio-nanocomposites containing cellulose nanocrystals extracted from different natural sources: part I.

Science.gov (United States)

Fortunati, E; Puglia, D; Luzi, F; Santulli, C; Kenny, J M; Torre, L

2013-09-12

PVA bio-nanocomposites reinforced with cellulose nanocrystals (CNC) extracted from commercial microcrystalline cellulose (MCC) and from two types of natural fibres, Phormium tenax and Flax of the Belinka variety, were produced by solvent casting in water. Morphological, thermal, mechanical and transparency properties were studied while the respective efficiency of the extraction process of CNC from the three sources was evaluated. The effect of CNC types and content on PVA properties and water absorption capacity were also evaluated. Natural fibres offered higher levels of extraction efficiency when compared with MCC hydrolysis yield. Thermal analysis proved that CNC promotes the crystallization of the PVA matrix, while improving its plastic response. It was also clarified that all PVA/CNC systems remain transparent due to CNC dispersion at the nanoscale, while being all saturated after the first 18-24h of water absorption. Copyright © 2013 Elsevier Ltd. All rights reserved.

Numerical Simulation of Dispersion from Urban Greenhouse Gas Sources

Science.gov (United States)

Nottrott, Anders; Tan, Sze; He, Yonggang; Winkler, Renato

2017-04-01

Cities are characterized by complex topography, inhomogeneous turbulence, and variable pollutant source distributions. These features create a scale separation between local sources and urban scale emissions estimates known as the Grey-Zone. Modern computational fluid dynamics (CFD) techniques provide a quasi-deterministic, physically based toolset to bridge the scale separation gap between source level dynamics, local measurements, and urban scale emissions inventories. CFD has the capability to represent complex building topography and capture detailed 3D turbulence fields in the urban boundary layer. This presentation discusses the application of OpenFOAM to urban CFD simulations of natural gas leaks in cities. OpenFOAM is an open source software for advanced numerical simulation of engineering and environmental fluid flows. When combined with free or low cost computer aided drawing and GIS, OpenFOAM generates a detailed, 3D representation of urban wind fields. OpenFOAM was applied to model scalar emissions from various components of the natural gas distribution system, to study the impact of urban meteorology on mobile greenhouse gas measurements. The numerical experiments demonstrate that CH4 concentration profiles are highly sensitive to the relative location of emission sources and buildings. Sources separated by distances of 5-10 meters showed significant differences in vertical dispersion of plumes, due to building wake effects. The OpenFOAM flow fields were combined with an inverse, stochastic dispersion model to quantify and visualize the sensitivity of point sensors to upwind sources in various built environments. The Boussinesq approximation was applied to investigate the effects of canopy layer temperature gradients and convection on sensor footprints.

Hiding the Source Based on Limited Flooding for Sensor Networks.

Science.gov (United States)

Chen, Juan; Lin, Zhengkui; Hu, Ying; Wang, Bailing

2015-11-17

Wireless sensor networks are widely used to monitor valuable objects such as rare animals or armies. Once an object is detected, the source, i.e., the sensor nearest to the object, generates and periodically sends a packet about the object to the base station. Since attackers can capture the object by localizing the source, many protocols have been proposed to protect source location. Instead of transmitting the packet to the base station directly, typical source location protection protocols first transmit packets randomly for a few hops to a phantom location, and then forward the packets to the base station. The problem with these protocols is that the generated phantom locations are usually not only near the true source but also close to each other. As a result, attackers can easily trace a route back to the source from the phantom locations. To address the above problem, we propose a new protocol for source location protection based on limited flooding, named SLP. Compared with existing protocols, SLP can generate phantom locations that are not only far away from the source, but also widely distributed. It improves source location security significantly with low communication cost. We further propose a protocol, namely SLP-E, to protect source location against more powerful attackers with wider fields of vision. The performance of our SLP and SLP-E are validated by both theoretical analysis and simulation results.

Wood wastes and residues generated along the Colorado Front Range as a potential fuel source

Science.gov (United States)

Julie E. Ward; Kurt H. Mackes; Dennis L. Lynch

2004-01-01

Throughout the United States there is interest in utilizing renewable fuel sources as an alternative to coal and nat-ural gas. This project was initiated to determine the availability of wood wastes and residues for use as fuel in ce-ment kilns and power plants located along the Colorado Front Range. Research was conducted through literature searches, phone surveys,...

Geochemistry and carbon isotopic ratio for assessment of PM10 composition, source and seasonal trends in urban environment.

Science.gov (United States)

Di Palma, A; Capozzi, F; Agrelli, D; Amalfitano, C; Giordano, S; Spagnuolo, V; Adamo, P

2018-08-01

Investigating the nature of PM 10 is crucial to differentiate sources and their relative contributions. In this study we compared the levels, and the chemical and mineralogical properties of PM 10 particles sampled in different seasons at monitoring stations representative of urban background, urban traffic and suburban traffic areas of Naples city. The aims were to relate the PM 10 load and characteristics to the location of the monitoring stations, to investigate the different sources contributing to PM 10 and to highlight PM 10 seasonal variability. Bulk analyses of chemical species in the PM 10 fraction included total carbon and nitrogen, δ 13 C and other 20 elements. Both natural and anthropogenic sources were found to contribute to the exceedances of the EU PM 10 limit values. The natural contribution was mainly related to marine aerosols and soil dust, as highlighted by X-ray diffractometry and SEM-EDS microscopy. The percentage of total carbon suggested a higher contribution of biogenic components to PM 10 in spring. However, this result was not supported by the δ 13 C values which were seasonally homogeneous and not sufficient to extract single emission sources. No significant differences, in terms of PM 10 load and chemistry, were observed between monitoring stations with different locations, suggesting a homogeneous distribution of PM 10 on the studied area in all seasons. The anthropogenic contribution to PM 10 seemed to dominate in all sites and seasons with vehicular traffic acting as a main source mostly by generation of non-exhaust emissions Our findings reinforce the need to focus more on the analysis of PM 10 in terms of quality than of load, to reconsider the criteria for the classification and the spatial distribution of the monitoring stations within urban and suburban areas, with a special attention to the background location, and to emphasize all the policies promoting sustainable mobility and reduction of both exhaust and not

The new atomic act. Radiation exposure from radon and natural radiation sources in workplaces and the experience of surveillance

International Nuclear Information System (INIS)

Sinaglova, R.

2018-01-01

In this presentation the new atomic act approved in the Czech republic is analyzed from the point of view of irradiation from radon and natural radiation sources in workplaces. Experience of supervision are also discussed. (authors)

Fast 3D elastic micro-seismic source location using new GPU features

Science.gov (United States)

Xue, Qingfeng; Wang, Yibo; Chang, Xu

2016-12-01

In this paper, we describe new GPU features and their applications in passive seismic - micro-seismic location. Locating micro-seismic events is quite important in seismic exploration, especially when searching for unconventional oil and gas resources. Different from the traditional ray-based methods, the wave equation method, such as the method we use in our paper, has a remarkable advantage in adapting to low signal-to-noise ratio conditions and does not need a person to select the data. However, because it has a conspicuous deficiency due to its computation cost, these methods are not widely used in industrial fields. To make the method useful, we implement imaging-like wave equation micro-seismic location in a 3D elastic media and use GPU to accelerate our algorithm. We also introduce some new GPU features into the implementation to solve the data transfer and GPU utilization problems. Numerical and field data experiments show that our method can achieve a more than 30% performance improvement in GPU implementation just by using these new features.

Teaching about Natural Background Radiation

Science.gov (United States)

Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

2013-01-01

Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

Time-lapse controlled-source electromagnetics using interferometry

NARCIS (Netherlands)

Hunziker, J.W.; Slob, E.C.; Wapenaar, C.P.A.

In time-lapse controlled-source electromagnetics, it is crucial that the source and the receivers are positioned at exactly the same location at all times of measurement. We use interferometry by multidimensional deconvolution (MDD) to overcome problems in repeatability of the source location.

Stable Isotope Identification of Nitrogen Sources for United ...

Science.gov (United States)

We used natural abundance stable isotope data to evaluate nitrogen sources to U.S. west coast estuaries. We collected δ15N of macroalgae data and supplemented this with available data from the literature for estuaries from Mexico to Alaska. Stable isotope ratios of green macroalgae were compared to δ15N of dissolved inorganic nitrogen of oceanic and watershed end members. There was a latitudinal gradient in δ15N of macroalgae with southern estuaries being 7 per mil heavier than northern estuaries. Gradients in isotope data were compared to nitrogen sources estimated by the USGS using the SPARROW model. In California estuaries, the elevation of isotope data appeared to be related to anthropogenic nitrogen sources. In Oregon systems, the nitrogen levels of streams flowing into the estuaries are related to forest cover, rather than to developed land classes. In addition, the δ15N of macroalgae suggested that the ocean and nitrogen-fixing trees in the watersheds were the dominant nitrogen sources. There was also a strong gradient in δ15N of macroalgae with heavier sites located near the estuary mouth. In some Oregon estuaries, there was an elevation an elevation of δ15N above marine end members in the vicinity of wastewater treatment facility discharge locations, suggesting isotopes may be useful for distinguishing inputs along an estuarine gradient. Nutrients are the leading cause of water quality impairments in the United States, and as a result too

Source tracing of natural organic matter bound mercury in boreal forest runoff with mercury stable isotopes.

Science.gov (United States)

Jiskra, Martin; Wiederhold, Jan G; Skyllberg, Ulf; Kronberg, Rose-Marie; Kretzschmar, Ruben

2017-10-18

Terrestrial runoff represents a major source of mercury (Hg) to aquatic ecosystems. In boreal forest catchments, such as the one in northern Sweden studied here, mercury bound to natural organic matter (NOM) represents a large fraction of mercury in the runoff. We present a method to measure Hg stable isotope signatures of colloidal Hg, mainly complexed by high molecular weight or colloidal natural organic matter (NOM) in natural waters based on pre-enrichment by ultrafiltration, followed by freeze-drying and combustion. We report that Hg associated with high molecular weight NOM in the boreal forest runoff has very similar Hg isotope signatures as compared to the organic soil horizons of the catchment area. The mass-independent fractionation (MIF) signatures (Δ 199 Hg and Δ 200 Hg) measured in soils and runoff were in agreement with typical values reported for atmospheric gaseous elemental mercury (Hg 0 ) and distinctly different from reported Hg isotope signatures in precipitation. We therefore suggest that most Hg in the boreal terrestrial ecosystem originated from the deposition of Hg 0 through foliar uptake rather than precipitation. Using a mixing model we calculated the contribution of soil horizons to the Hg in the runoff. At moderate to high flow runoff conditions, that prevailed during sampling, the uppermost part of the organic horizon (Oe/He) contributed 50-70% of the Hg in the runoff, while the underlying more humified organic Oa/Ha and the mineral soil horizons displayed a lower mobility of Hg. The good agreement of the Hg isotope results with other source tracing approaches using radiocarbon signatures and Hg : C ratios provides additional support for the strong coupling between Hg and NOM. The exploratory results from this study illustrate the potential of Hg stable isotopes to trace the source of Hg from atmospheric deposition through the terrestrial ecosystem to soil runoff, and provide a basis for more in-depth studies investigating the

Interpretation of uranium and thorium excretion data taking into account excretion data caused by natural sources

International Nuclear Information System (INIS)

Sahre, P.; Schoenmuth, Th.; Helling, K.

2000-01-01

At the Nuclear Engineering and Analytics Inc. Rossendorf near Dresden (Germany) occupationally exposed persons are working with Uranium and Thorium. In accordance with German guides urine and faecal analysis is carried out. But for the interpretation the data in terms of dose or intake it is important to have knowledge about the portion of the activity measured caused by natural sources. For this reason 16 occupationally exposed persons who did not have any history of occupational exposure to Thorium or Uranium have been checked concerning the excretion data since 1994. The excretion data in mBq per day for all persons covers the following ranges: Faeces: U-234 1 to 310 mBq/d, U-235 0.2 to 3.7 mBq/d, U-238 1.3 to 72 mBq/d. Th-228 7 to 89 mBq/d, Th-230 0.7 to 19 mBq/d, Th-232 0.7 to 16 mBq/d. Urine: all values below the detection limits of about 1 mBq/l. The large variation results from differences between the individual excretion rates but also from the variation of the excretion rate of one person. For example, the U-234-faecal excretion of one person reaches from 77 to 310 mBq per day. In the paper the faecal excretion for some individuals in dependence on the time are given. These excretion date caused by natural sources are taken into account by interpreting faecal excretion data of occupationally exposed persons working with Uranium or Thorium. If the measured faecal excretion per day is within the range caused by natural sources no interpretation will be done. By exceeding these values additional faeces and urine samples will be collected and measured. In dependence on these additional results intake and dose will be assessed some times by using lung counter or whole body counter measuring results. In the paper some examples are described. (author)

A carborne gamma-ray spectrometer system for natural radioactivity mapping and environmental monitoring

International Nuclear Information System (INIS)

Grasty, R.L.; Cox, J.R.

1997-01-01

This paper summarizes the experience gained in the use of a carborne gamma-ray spectrometer system for mapping both natural and man-made radiation. Particular emphasis is placed on the calibration of the system for converting the gamma-ray measurements to ground concentrations of potassium, uranium and thorium and the activity of 137 Cs. During the Finnish Emergency Response Exercise (Resume95), the carborne system was shown to be effective in mapping both natural and man-made radiation from 137 Cs fallout and in locating radioactive sources. The application of the carborne system for mineral exploration is also demonstrated. (au)

Global mapping of transposon location.

Directory of Open Access Journals (Sweden)

Abram Gabriel

2006-12-01

Full Text Available Transposable genetic elements are ubiquitous, yet their presence or absence at any given position within a genome can vary between individual cells, tissues, or strains. Transposable elements have profound impacts on host genomes by altering gene expression, assisting in genomic rearrangements, causing insertional mutations, and serving as sources of phenotypic variation. Characterizing a genome's full complement of transposons requires whole genome sequencing, precluding simple studies of the impact of transposition on interindividual variation. Here, we describe a global mapping approach for identifying transposon locations in any genome, using a combination of transposon-specific DNA extraction and microarray-based comparative hybridization analysis. We use this approach to map the repertoire of endogenous transposons in different laboratory strains of Saccharomyces cerevisiae and demonstrate that transposons are a source of extensive genomic variation. We also apply this method to mapping bacterial transposon insertion sites in a yeast genomic library. This unique whole genome view of transposon location will facilitate our exploration of transposon dynamics, as well as defining bases for individual differences and adaptive potential.

Components of natural irradiation and local variations

International Nuclear Information System (INIS)

Bouville, A.

1985-01-01

The purpose of this paper is to give an overview of the natural radiation environment and of the human exposures from natural radiation sources. Any form of life on earth is unavoidably associated with exposure to natural radiation. There are two kinds of sources of natural radiation: sources in the extraterrestrial environment (i.e. cosmic rays); terrestrial sources (i.e. the radioactive substances in the earth's crust). Both types of sources irradiate the human body from outside but also from inside as naturally occuring nuclides are taken up into the body through normal physiological pathways. When living in a natural environment, man is exposed to all these sources. On the average, the exposure from natural radiation is much greater than the exposures from artificial sources. The extraterrestrial sources and the terrestrial sources will be considered in succession. Some emphasis will be placed on the internal exposures but external exposures will also be discussed. The exposures will be expressed in terms of effective dose equivalent, which is a quantity assumed to be proportional to the radiation risk. Most of the information will be taken from the latest UNSCEAR report, which periodically reviews the information on the sources and effects of ionizing radiation [fr

Determinants of Recent Immigrants' Location Choices

DEFF Research Database (Denmark)

Damm, Anna Piil

This paper exploits a Danish spatial dispersal policy on refugees which can be regarded a natural experiment to investigate the influence of regional factors on recent immigrants' locational choices. The main push factors are lack of co-ethnics and presence of immigrants. Additional push factors...

Location - Managed Facility - St. Paul District (MVP)

Data.gov (United States)

Army Corps of Engineers, Department of the Army, Department of Defense — St. Paul District - US Army Corps of Engineers Managed Facility locations. District headquarters, Natural Resource, Recreation, Lock and Dam, and Regulatory offices...

Application of algorithms and artificial-intelligence approach for locating multiple harmonics in distribution systems

Energy Technology Data Exchange (ETDEWEB)

Hong, Y.-Y.; Chen, Y.-C. [Chung Yuan University (China). Dept. of Electrical Engineering

1999-05-01

A new method is proposed for locating multiple harmonic sources in distribution systems. The proposed method first determines the proper locations for metering measurement using fuzzy clustering. Next, an artificial neural network based on the back-propagation approach is used to identify the most likely location for multiple harmonic sources. A set of systematic algorithmic steps is developed until all harmonic locations are identified. The simulation results for an 18-busbar system show that the proposed method is very efficient in locating the multiple harmonics in a distribution system. (author)

Hiding the Source Based on Limited Flooding for Sensor Networks

Directory of Open Access Journals (Sweden)

Juan Chen

2015-11-01

Full Text Available Wireless sensor networks are widely used to monitor valuable objects such as rare animals or armies. Once an object is detected, the source, i.e., the sensor nearest to the object, generates and periodically sends a packet about the object to the base station. Since attackers can capture the object by localizing the source, many protocols have been proposed to protect source location. Instead of transmitting the packet to the base station directly, typical source location protection protocols first transmit packets randomly for a few hops to a phantom location, and then forward the packets to the base station. The problem with these protocols is that the generated phantom locations are usually not only near the true source but also close to each other. As a result, attackers can easily trace a route back to the source from the phantom locations. To address the above problem, we propose a new protocol for source location protection based on limited flooding, named SLP. Compared with existing protocols, SLP can generate phantom locations that are not only far away from the source, but also widely distributed. It improves source location security significantly with low communication cost. We further propose a protocol, namely SLP-E, to protect source location against more powerful attackers with wider fields of vision. The performance of our SLP and SLP-E are validated by both theoretical analysis and simulation results.

A Preliminary ZEUS Lightning Location Error Analysis Using a Modified Retrieval Theory

Science.gov (United States)

Elander, Valjean; Koshak, William; Phanord, Dieudonne

2004-01-01

The ZEUS long-range VLF arrival time difference lightning detection network now covers both Europe and Africa, and there are plans for further expansion into the western hemisphere. In order to fully optimize and assess ZEUS lightning location retrieval errors and to determine the best placement of future receivers expected to be added to the network, a software package is being developed jointly between the NASA Marshall Space Flight Center (MSFC) and the University of Nevada Las Vegas (UNLV). The software package, called the ZEUS Error Analysis for Lightning (ZEAL), will be used to obtain global scale lightning location retrieval error maps using both a Monte Carlo approach and chi-squared curvature matrix theory. At the core of ZEAL will be an implementation of an Iterative Oblate (IO) lightning location retrieval method recently developed at MSFC. The IO method will be appropriately modified to account for variable wave propagation speed, and the new retrieval results will be compared with the current ZEUS retrieval algorithm to assess potential improvements. In this preliminary ZEAL work effort, we defined 5000 source locations evenly distributed across the Earth. We then used the existing (as well as potential future ZEUS sites) to simulate arrival time data between source and ZEUS site. A total of 100 sources were considered at each of the 5000 locations, and timing errors were selected from a normal distribution having a mean of 0 seconds and a standard deviation of 20 microseconds. This simulated "noisy" dataset was analyzed using the IO algorithm to estimate source locations. The exact locations were compared with the retrieved locations, and the results are summarized via several color-coded "error maps."

Mercury and cadmium in ringed seals in the Canadian Arctic: Influence of location and diet

Energy Technology Data Exchange (ETDEWEB)

Brown, Tanya M., E-mail: tanya.brown@mun.ca [Memorial University of Newfoundland, St. John' s, Newfoundland A1B 3X9 (Canada); Fisk, Aaron T. [Great Lakes Institute of Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, Ontario N9B 3P4 (Canada); Wang, Xiaowa [Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario L7R 4A6 (Canada); Ferguson, Steven H. [Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba R3T 2N6 (Canada); Young, Brent G. [University of Manitoba, 500 University Crescent, Winnipeg, Manitoba R3T 2N2 (Canada); Reimer, Ken J. [Environmental Sciences Group, Royal Military College of Canada, PO Box 17000, Stn Forces, Kingston, Ontario K7K 7B4 (Canada); Muir, Derek C.G. [Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario L7R 4A6 (Canada)

2016-03-01

Concentrations of total mercury (THg) and total cadmium (TCd) were determined in muscle and liver of ringed seals (Pusa hispida) from up to 14 locations across the Canadian Arctic. Location, trophic position (TP) and relative carbon source best predicted the THg and TCd concentrations in ringed seals. THg concentrations in ringed seals were highest in the western Canadian Arctic (Beaufort Sea), whereas TCd was highest in the eastern Canadian Arctic (Hudson Bay and Labrador). A positive relationship between THg and TP and a negative relationship between THg and relative carbon source contributed to the geographical patterns observed and elevated THg levels at certain sites. In contrast, a negative relationship between TCd and TP was found, indicating that high TCd concentrations are related to seals feeding more on invertebrates than fish. Feeding ecology appears to play an important role in THg and TCd levels in ringed seals, with biomagnification driving elevated THg levels and a dependence on low-trophic position prey resulting in high TCd concentrations. The present study shows that both natural geological differences and diet variability among regions explain the spatial patterns for THg and TCd concentrations in ringed seals. - Highlights: • Diet and location influenced THg and Cd in ringed seals across the Canadian Arctic. • Biomagnification processes contribute to elevated THg levels in the western Arctic. • Consuming low-trophic position prey explains high Cd levels in the eastern Arctic.

Mercury and cadmium in ringed seals in the Canadian Arctic: Influence of location and diet

International Nuclear Information System (INIS)

Brown, Tanya M.; Fisk, Aaron T.; Wang, Xiaowa; Ferguson, Steven H.; Young, Brent G.; Reimer, Ken J.; Muir, Derek C.G.

2016-01-01

Concentrations of total mercury (THg) and total cadmium (TCd) were determined in muscle and liver of ringed seals (Pusa hispida) from up to 14 locations across the Canadian Arctic. Location, trophic position (TP) and relative carbon source best predicted the THg and TCd concentrations in ringed seals. THg concentrations in ringed seals were highest in the western Canadian Arctic (Beaufort Sea), whereas TCd was highest in the eastern Canadian Arctic (Hudson Bay and Labrador). A positive relationship between THg and TP and a negative relationship between THg and relative carbon source contributed to the geographical patterns observed and elevated THg levels at certain sites. In contrast, a negative relationship between TCd and TP was found, indicating that high TCd concentrations are related to seals feeding more on invertebrates than fish. Feeding ecology appears to play an important role in THg and TCd levels in ringed seals, with biomagnification driving elevated THg levels and a dependence on low-trophic position prey resulting in high TCd concentrations. The present study shows that both natural geological differences and diet variability among regions explain the spatial patterns for THg and TCd concentrations in ringed seals. - Highlights: • Diet and location influenced THg and Cd in ringed seals across the Canadian Arctic. • Biomagnification processes contribute to elevated THg levels in the western Arctic. • Consuming low-trophic position prey explains high Cd levels in the eastern Arctic.

Internal Domains of Natural Porous Media Revealed: Critical Locations for Transport, Storage, and Chemical Reaction